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Sample records for intraventricular conduction delay

  1. Beneficial effects of biventricular pacing in a patient with hypertrophic cardiomyopathy and intraventricular conduction delay

    OpenAIRE

    Rinaldi, C A; Bucknall, C A; Gill, J S

    2002-01-01

    The beneficial use of biventricular pacing is reported in a patient with hypertrophic cardiomyopathy and intraventricular conduction delay. This resulted in improvements in symptomatic status and exercise tolerance that may be related to cardiac resynchronisation. The improvement in symptoms by biventricular pacing in a patient with hypertrophic cardiomyopathy and intraventricular conduction delay is previously undocumented and requires further investigation.

  2. Prognostic significance of delayed intraventricular haemorrhage in the INTERACT studies.

    Science.gov (United States)

    Moullaali, Tom J; Sato, Shoichiro; Wang, Xia; Rabinstein, Alejandro A; Arima, Hisatomi; Carcel, Cheryl; Chen, Guofang; Robinson, Thompson; Heeley, Emma; Chan, Edward; Delcourt, Candice; Stapf, Christian; Cordonnier, Charlotte; Lindley, Richard I; Chalmers, John; Anderson, Craig S

    2017-01-01

    Intraventricular extension of intracerebral haemorrhage (ICH) predicts poor outcome, but the significance of delayed intraventricular haemorrhage (dIVH) is less well defined. We determined the prognostic significance of dIVH in the Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trials (INTERACT 1 and 2). Pooled analyses of the INTERACT CT substudies-international, multicentre, prospective, open, blinded end point, randomised controlled trials of patients with acute spontaneous ICH and elevated systolic blood pressure (SBP)-randomly assigned to intensive (<140 mm Hg) or guideline-based (<180 mm Hg) SBP management. Participants had blinded central analyses of baseline and 24 h CTs, with dIVH defined as new intraventricular haemorrhage (IVH) on the latter scan. Outcomes of death and major disability were defined by modified Rankin Scale scores at 90 days. There were 349 (27%) of 1310 patients with baseline IVH, and 107 (11%) of 961 initially IVH-free patients who developed dIVH. Significant associations of dIVH were prior warfarin anticoagulation, high (≥15) baseline National Institutes of Health Stroke Scale score, larger (≥15 mL) ICH volume, greater ICH growth and higher achieved SBP over 24 h. Compared with those who were IVH-free, dIVH had greater odds of 90-day death or major disability versus initial IVH (adjusted ORs 2.84 (95% CI 1.52 to 5.28) and 1.87 (1.36 to 2.56), respectively (p trend <0.0001)). Although linked to factors determining greater ICH growth including poor SBP control, dIVH is independently associated with poor outcome in acute small to moderate-size ICH. NCT00226096 and NCT00716079. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  3. [Vectorcardiographic manifestations of left intraventricular conduction disorders].

    Science.gov (United States)

    de Micheli, A; Medrano, G A

    1979-01-01

    Both, the vectorcardiographic changes produced by the various degrees of left bundle branch block and these observed with the different types of left distal block, are described. When a "wave jumping" phenomenon exists, the vectorcardiographic changes are more characteristic in the horizontal plane than in the frontal plane and can be interpreted satisfactorily in basis of the ventricular activation sequence. The normal counterclockwise rotation of the horizontal vectorcardiogram persists in the presence of left bundle branch block of slight and moderate degrees, since the electromotive forces of the free left ventricular wall are still predominant. In the majority of intermediate degree blocks, the middle portion of the RH loop develops with a clockwise rotation and general aspect with a clockwise rotation and the general aspect of the ventricular loop resembles an eight figure. This is due to the electromotive forces originated by the delayed depolarization of the left septal mass that starts to predominate. With advanced degrees of block, the largest portion of the RH loop shows a clockwise rotation, as well as marked notchings and slurrings. The initial anterior portion of the horizontal vectorcardiogram does not disappear, but is situated to the left of the anterior-posterior axis with a counterclockwise rotation (first right septal vector). Otherwise, the direct electrical sign of left distal block emphasized: evidence of delayed activation in a limited zone of the homolateral ventricle. This local delay gives rise to an asynchronism of the activation phenomenon between the upper and lower regions of the ventricle. The diagnosis of left bifascicular block is based essentially on the evidence of unequal delay of the activation sequence in the basal regions and in the inferior ones of the homolateral ventricle and also on the frequent persistence of the first left septal vector.

  4. HEREDITARY INTRAVENTRICULAR CONDUCTION DISORDERS IN THE FAMILY FROM KRASNOYARSK

    Directory of Open Access Journals (Sweden)

    A. A. Chernova

    2011-01-01

    Full Text Available Pedigree of the family from Krasnoyarsk city with hereditary disorders of intracardiac conduction was studied. The diagnosis of each family member was verified by electrocardiography (ECG, echocardiography , bicycle ergometry , ECG Holter monitoring. The family 10-year follow-up showed familial aggregation of intracardiac conduction disorders in grandson, niece, son of the proband niece, ie, in the III-degree relatives. Family history of III-degree relatives with intracardiac conduction disorders and discordant pathology is identified.

  5. [The influence of hemodialysis on heart's intraventricular conduction system--pilot study].

    Science.gov (United States)

    Polak-Jonkisz, Dorota; Laszki-Szczachor, Krystyna; Zwolińska, Danuta; Rusiecki, Lesław; Miler, Maria; Sobieszczańska, Małgorzata

    2009-04-01

    The highest percent of cardiac muscle damages is written down in children which are exposed to hemodialysis. In this group the heart examinations using body surface heart potential mapping (BSPM) method have been carried out. The aim of the study was to assess the influence of hemodialysis on heart's electrodynamics in children and adolescent during replacement therapy. Multielectrode recording have been done in every kid before and after hemodialysis. For every record it was created isopotential map. By the comparing our maps with model maps for healthy children it was affirmed that in greater part of studied examples of hemodialysed children there are present early changes indicating conducting disturbances in left bundle of fasciculus atrioventricularis (His) and initial stage of left ventricular hypertrophy (LVH). That changes haven't been confirmed in classic ECG, which suggests that the disturbances in excitation conductance observed on isointegral maps are far beyond the area detected by 12-electrode classic ECG recording. The maps made before dialysis are characterised by large, unsymmetrical isopotential lines changes over the left and right ventricle. After carried out of hemodialysis the image of ECG records was improving. In all of cases the isoline distribution in sternal and anterior lower left part of chest comes back to norm. Changes are visible merely over the left ventricle and in anterior upper right part of chest what is connected with just stabilised conducting disturbances in the left branch of His bundle, left bundle of fasciculus atrioventricularis (His bundle). 1. In children who are treated by repeated hemodialysis approach to disturbances in the cardiac intraventricular conduction system. 2. Those disturbances are improved by a singular hemodialysis. 3. BSPM method detects earlier changes in the cardiac intraventricular conduction system than the classical ECG.

  6. Intraventricular tuberculoma

    International Nuclear Information System (INIS)

    Berthier, M.; Sierra, J.; Leiguarda, R.

    1987-01-01

    Four cases of intraventricular tuberculoma (IVT) in children are here reported. In none of the patients was there clinical evidence pointing to the intraventricular location. CT scan findings comprised three stages of development, namely: immature, mature and old. Ependymal attachment and asymmetric hydrocephalus were present in three cases, meningitis in two and ependymitis in one. Septum pellucidum traction was clearly observed in two patients, strongly supporting an adhesive process characteristic of intraventricular tuberculosis. Following specific treatment, the tuberculomas remitted partially or entirely. (orig.)

  7. Criteria for intraventricular conduction disturbances and pre-excitation. World Health Organizational/International Society and Federation for Cardiology Task Force Ad Hoc.

    Science.gov (United States)

    Willems, J L; Robles de Medina, E O; Bernard, R; Coumel, P; Fisch, C; Krikler, D; Mazur, N A; Meijler, F L; Mogensen, L; Moret, P

    1985-06-01

    In an effort to standardize terminology and criteria for clinical electrocardiography, and as a follow-up of its work on definitions of terms related to cardiac rhythm, an Ad Hoc Working Group established by the World Health Organization and the International Society and Federation of Cardiology reviewed criteria for the diagnosis of conduction disturbances and pre-excitation. Recommendations resulting from these discussions are summarized for the diagnosis of complete and incomplete right and left bundle branch block, left anterior and left posterior fascicular block, nonspecific intraventricular block, Wolff-Parkinson-White syndrome and related pre-excitation patterns. Criteria for intraatrial conduction disturbances are also briefly reviewed. The criteria are described in clinical terms. A concise description of the criteria using formal Boolean logic is given in the Appendix. For the incorporation into computer electrocardiographic analysis programs, the limits of some interval measurements may need to be adjusted.

  8. Bidirectional superior vena cava: Right atrial conduction delay during tachycardia

    NARCIS (Netherlands)

    A.S. Thornton (Andrew); M. Rivero-Ayerza (Maximo); J.M. Mekel (Joris); L.J.L.M. Jordaens (Luc)

    2007-01-01

    textabstractThe superior vena cava, like all the thoracic veins, has myocardial sleeves and plays a role in initiation and perpetuation of atrial fibrillation. Conduction delay between it and the right atrium has been shown previously. This case study shows delay in both directions during different

  9. Intraventricular hemorrhage of the newborn

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/007301.htm Intraventricular hemorrhage of the newborn To use the sharing features on this page, please enable JavaScript. Intraventricular hemorrhage (IVH) of the newborn is bleeding into the ...

  10. THE PREVALENCE OF INTRAVENTRICULAR HAEMORRHAGE

    African Journals Online (AJOL)

    Esem

    and also as the dependent variable in multivariate logistic regression. Any-IVH was the highest grade of IVH .... Risk factors studied were mode of delivery, sex, prolonged rupture of membranes (PROM - at least 18 ..... Mohamed AM, Hany A Transport of premature infants is associated with increased risk for intraventricular.

  11. Effect of Phase Response Curve Skew on Synchronization with and without Conduction Delays

    Directory of Open Access Journals (Sweden)

    Carmen eCanavier

    2013-12-01

    Full Text Available A central problem in cortical processing including sensory binding and attentional gating is how neurons can synchronize their responses with zero or near-zero time lag. For a spontaneously firing neuron, an input from another neuron can delay or advance the next spike by different amounts depending upon the timing of the input relative to the previous spike. This information constitutes the phase response curve (PRC. We present a simple graphical method for determining the effect of PRC shape on synchronization tendencies and illustrate it using type 1 PRCs, which consist entirely of advances (delays in response to excitation (inhibition. We obtained the following generic solutions for type 1 PRCs, which include the pulse coupled leaky integrate and fire model. For pairs with mutual excitation, exact synchrony can be stable for strong coupling because of the stabilizing effect of the causal limit region of the PRC in which an input triggers a spike immediately upon arrival. However, synchrony is unstable for short delays, because delayed inputs arrive during a refractory period and cannot trigger an immediate spike. Right skew destabilizes antiphase and enables modes with time lags that grow as the conduction delay is increased. Therefore, right skew favors near-synchrony at short conduction delays and a gradual transition between synchrony and antiphase for pairs coupled by mutual excitation. For pairs with mutual inhibition, zero time lag synchrony is stable for conduction delays ranging from zero to a substantial fraction of the period for pairs. However, for right skew there is a preferred antiphase mode at short delays. In contrast to mutual excitation, left skew destabilizes antiphase for mutual inhibition so that synchrony dominates at short delays as well. These pairwise synchronization tendencies constrain the synchronization properties of neurons embedded in larger networks.

  12. MRI in cerebral intraventricular hemorrhage: analysis of 50 consecutive cases

    Energy Technology Data Exchange (ETDEWEB)

    Bakshi, R.; Kamran, S.; Kinkel, P.R.; Bates, V.E.; Mechtler, L.L.; Belani, S.L.; Kinkel, W.R. [Dent Neurologic Institute, Lucy Dent Imaging Center, Kaleida Health, Neuroscience Center E-2 State University of NY at Buffalo, Buffalo, NY 14203 (United States)

    1999-06-01

    MRI of intraventricular haemorrhage (IVH) has not been studied formally. We aimed to describe the degradation rate and patterns shown on 1.5 T MRI in IVH, comparing them to other coexisting brain hemorrhage. We studied 50 consecutive cases using T1-, proton-density, and T2-weighted images. IVH was seen in two forms: layered (free-flowing in ventricles) (37 cases) and/or clotted (31). Both were best shown by proton-density image. Layered IVH was seen in the dependent portions of the lateral ventricles with fluid (``blood-CSF``) levels, degrading more slowly than both clotted IVH and intraparenchymal hemorrhages (IPH) (acute blood products persisting for several more days; P<0.05). Clotted IVH degraded at a rate comparable to IPH. IVH cleared rapidly and did not form hemosiderin. Subarachnoid hemorrhage (SAH) cleared faster and was less conspicuous than IVH. Hypertensive (22), aneurysmal (11), traumatic (2), idiopathic (9), or vascular malformation-related (6) IVH were seen. IVH coexisted with IPH (30) or SAH (12), or both (12). The high rate of layering with blood-CSF levels in IVH is most likely due to different densities of blood components and CSF and the fibrinolytic capability of the latter. Delayed degradation of layered IVH probably reflects high intra-ventricular oxygen and glucose content. Further study is necessary to determine if MRI characteristics of IVH are helpful in excluding other intraventricular diseases such as neoplasia and pyocephalus. (orig.) With 7 figs., 2 tabs., 38 refs.

  13. Augmented reality in intraventricular neuroendoscopy.

    Science.gov (United States)

    Finger, T; Schaumann, A; Schulz, M; Thomale, Ulrich-W

    2017-06-01

    Individual planning of the entry point and the use of navigation has become more relevant in intraventricular neuroendoscopy. Navigated neuroendoscopic solutions are continuously improving. We describe experimentally measured accuracy and our first experience with augmented reality-enhanced navigated neuroendoscopy for intraventricular pathologies. Augmented reality-enhanced navigated endoscopy was tested for accuracy in an experimental setting. Therefore, a 3D-printed head model with a right parietal lesion was scanned with a thin-sliced computer tomography. Segmentation of the tumor lesion was performed using Scopis NovaPlan navigation software. An optical reference matrix is used to register the neuroendoscope's geometry and its field of view. The pre-planned ROI and trajectory are superimposed in the endoscopic image. The accuracy of the superimposed contour fitting on endoscopically visualized lesion was acquired by measuring the deviation of both midpoints to one another. The technique was subsequently used in 29 cases with CSF circulation pathologies. Navigation planning included defining the entry points, regions of interests and trajectories, superimposed as augmented reality on the endoscopic video screen during intervention. Patients were evaluated for postoperative imaging, reoperations, and possible complications. The experimental setup revealed a deviation of the ROI's midpoint from the real target by 1.2 ± 0.4 mm. The clinical study included 18 cyst fenestrations, ten biopsies, seven endoscopic third ventriculostomies, six stent placements, and two shunt implantations, being eventually combined in some patients. In cases of cyst fenestrations postoperatively, the cyst volume was significantly reduced in all patients by mean of 47%. In biopsies, the diagnostic yield was 100%. Reoperations during a follow-up period of 11.4 ± 10.2 months were necessary in two cases. Complications included one postoperative hygroma and one insufficient

  14. Conduction Delay Learning Model for Unsupervised and Supervised Classification of Spatio-Temporal Spike Patterns.

    Science.gov (United States)

    Matsubara, Takashi

    2017-01-01

    Precise spike timing is considered to play a fundamental role in communications and signal processing in biological neural networks. Understanding the mechanism of spike timing adjustment would deepen our understanding of biological systems and enable advanced engineering applications such as efficient computational architectures. However, the biological mechanisms that adjust and maintain spike timing remain unclear. Existing algorithms adopt a supervised approach, which adjusts the axonal conduction delay and synaptic efficacy until the spike timings approximate the desired timings. This study proposes a spike timing-dependent learning model that adjusts the axonal conduction delay and synaptic efficacy in both unsupervised and supervised manners. The proposed learning algorithm approximates the Expectation-Maximization algorithm, and classifies the input data encoded into spatio-temporal spike patterns. Even in the supervised classification, the algorithm requires no external spikes indicating the desired spike timings unlike existing algorithms. Furthermore, because the algorithm is consistent with biological models and hypotheses found in existing biological studies, it could capture the mechanism underlying biological delay learning.

  15. Conduction Delay Learning Model for Unsupervised and Supervised Classification of Spatio-Temporal Spike Patterns

    Directory of Open Access Journals (Sweden)

    Takashi Matsubara

    2017-11-01

    Full Text Available Precise spike timing is considered to play a fundamental role in communications and signal processing in biological neural networks. Understanding the mechanism of spike timing adjustment would deepen our understanding of biological systems and enable advanced engineering applications such as efficient computational architectures. However, the biological mechanisms that adjust and maintain spike timing remain unclear. Existing algorithms adopt a supervised approach, which adjusts the axonal conduction delay and synaptic efficacy until the spike timings approximate the desired timings. This study proposes a spike timing-dependent learning model that adjusts the axonal conduction delay and synaptic efficacy in both unsupervised and supervised manners. The proposed learning algorithm approximates the Expectation-Maximization algorithm, and classifies the input data encoded into spatio-temporal spike patterns. Even in the supervised classification, the algorithm requires no external spikes indicating the desired spike timings unlike existing algorithms. Furthermore, because the algorithm is consistent with biological models and hypotheses found in existing biological studies, it could capture the mechanism underlying biological delay learning.

  16. Intraventricular meningioma: a case report; Meningeoma intraventricular: relato de um caso

    Energy Technology Data Exchange (ETDEWEB)

    Rodacki, M.A.; Boer, V.H.; Borba, L.A.; Leite, B.M. [Hospital Santa Isabel, Blumenau, SC (Brazil); Feltrin, L.T.; Vieira, N.T.; Leite, B.M. [Fundacao Universidade Regional de Blumenau, SC (Brazil). Faculdade de Medicina

    1995-01-01

    A case of intraventricular meningioma in the trigonum of the right ventricle. The diagnosis was suggested by computed tomography of the brain and cerebral angiography. After surgical resection, the histopathological examination of the lesion confirmed the diagnosis of intraventricular meningioma. (author). 8 refs, 3 figs.

  17. Validation of double-spike electrograms as markers of conduction delay or block in atrial flutter.

    Science.gov (United States)

    Cosio, F G; Arribas, F; Barbero, J M; Kallmeyer, C; Goicolea, A

    1988-04-01

    Recent mapping studies of atrial flutter have shown that fragmented electrograms can be found in most cases from the posterior, posteroseptal and posterolateral walls of the right atrium. The fragmentation pattern most often consists of a double spike. To further assess double-spike electrograms as a possible marker of conduction delay, bipolar electrograms were continuously recorded during atrial overdrive pacing of common flutter from the right atrium (7 patients) and from the proximal coronary sinus (5). Baseline double-spike separation of 50 to 130 ms was unchanged in 1 patient and slightly increased (5 to 25 ms) in 4 by coronary sinus pacing. The electrogram sequence was unchanged and the surface morphology was similar to that of basal flutter. Right atrial pacing decreased double-spike separation by 25 to 85 ms from basal values of 45 to 175 ms (23 to 83%), suggesting fusion in the area of fragmented electrograms. These findings suggest that double-spike electrograms represent activation on both sides of a conduction delay zone. The changes induced in these electrograms by pacing from the anterior right atrium and the coronary sinus are consistent with flutter circuits rotating counterclockwise (frontal plane) in the posterior right atrial wall in common atrial flutter.

  18. A case of traumatic intraventricular hemorrhage

    International Nuclear Information System (INIS)

    Ikeda, Yukio; Yamakawa, Kazuomi; Nakazawa, Shozo.

    1980-01-01

    CT scan is recognized to be a rapid, noninvasive and informative examination in evaluation of the head injured patient. It is also possible to evaluate the presence of the intracerebral hematoma without remarkable mass effect, cerebral contusion, associated cerebral edema and ventricular hemorrhage. We present a case of traumatic intraventricular hemorrhage. The patient was a 40-year-old male admitted to our hospital in a drowsy state following a fall from about one meter high. Craniogram showed a linear fracture in the left parietotemporal regions. In the CT scan, intraventricular hemorrhage associated with subarachnoid hemorrhage without intracerebral hematoma was shown. A symmetrical moderate dilatation of both lateral ventricles was also shown. Cerebral angiography revealed no abnormality. His condition deteriorated progressively, so ventricular drainage was performed, but he expired 5 days later. Considering this case, the mechanisms of pure intraventricular hemorrhage following head injury were discussed. (author)

  19. MRI identification of intraventricular cysts; Identificacao de cistos intraventriculares por meio da ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho Neto, A. de [Parana Univ., Curitiba, PR (Brazil). Hospital das Clinicas; Rogacheski, E.; Escuissato, D.L.; Schmitz, N.R.; Mazer, S. [Hospital Nossa Senhora das Gracas, Curitiba, PR (Brazil). Servico de Tomografia Computadorizada e Ressonancia Magnetica da Liga das Senhoras Catolicas; Hagi, N.T.

    1994-10-01

    Neurocysticercosis has a high prevalence rate in southern Brazil, presenting a large scope of clinical and pathological manifestations. When hydrocephalus is present the demonstration of intraventricular cysts may have prognostic and therapeutic implications, nevertheless its pre-operative identification has been difficult by the low sensibility of the imaging methods employed so far. The authors report 7 cases of intraventricular cysticercosis shown by magnetic resonance imaging. (author). 14 refs, 7 figs.

  20. CASE REPORT 'Migrating' intraventricular neurocysticercus cyst

    African Journals Online (AJOL)

    6. Madrazo I, Garcia-Renteria JA, Sandoval M, et al. Intraventricular cysticercosis. Neurosurgery 1983; 12: 148-152. 7. Allcut DA, Coulthard A. Neurocysticercosis: regression of a fourth ventricular cyst with praziquantel. Neurol Neurosurg Psychiatry 1991; 54:461-462. Interventional Radiology Secrets. By David L. Waldman; ...

  1. The Prevalence of Intraventricular Haemorrhage and Associated ...

    African Journals Online (AJOL)

    The Prevalence of Intraventricular Haemorrhage and Associated Risk Factors in Preterm Neonates in the Neonatal Intensive Care Unit at the University Teaching ... any-IVH generated at the time of analysis was used in determining the prevalence of IVH and also as the dependent variable in multivariate logistic regression.

  2. Inhibition of Src family kinases improves cognitive function after intraventricular hemorrhage or intraventricular thrombin.

    Science.gov (United States)

    Liu, Da Zhi; Waldau, Ben; Ander, Bradley P; Zhan, Xinhua; Stamova, Boryana; Jickling, Glen C; Lyeth, Bruce G; Sharp, Frank R

    2017-07-01

    Intraventricular hemorrhage causes spatial memory loss, but the mechanism remains unknown. Our recent studies demonstrated that traumatic brain injury activates Src family kinases, which cause spatial memory loss. To test whether the spatial memory loss was due to blood in the ventricles, which activated Src family kinases, we infused autologous whole blood or thrombin into the lateral ventricles of adult rats to model non-traumatic intraventricular hemorrhage. Hippocampal neuron loss was examined 1 day to 5 weeks later. Spatial memory function was assessed 29 to 33 days later using the Morris water maze. Five weeks after the ventricular injections of blood or thrombin, there was death of most hippocampal neurons and significant memory deficits compared with sham operated controls. These data show that intraventricular thrombin is sufficient to kill hippocampal neurons and produce spatial memory loss. In addition, systemic administration of the non-specific Src family kinase inhibitor PP2 or intraventricular injection of siRNA-Fyn, a Src family kinase family member, prevented hippocampal neuronal loss and spatial memory deficits following intraventricular hemorrhage. The data support the conclusions that thrombin mediates the hippocampal neuronal cell death and spatial memory deficits produced by intraventricular blood and that these can be blocked by non-specific inhibition of Src family kinases or by inhibiting Fyn.

  3. Neocortical axon arbors trade-off material and conduction delay conservation.

    Directory of Open Access Journals (Sweden)

    Julian M L Budd

    2010-03-01

    Full Text Available The brain contains a complex network of axons rapidly communicating information between billions of synaptically connected neurons. The morphology of individual axons, therefore, defines the course of information flow within the brain. More than a century ago, Ramón y Cajal proposed that conservation laws to save material (wire length and limit conduction delay regulate the design of individual axon arbors in cerebral cortex. Yet the spatial and temporal communication costs of single neocortical axons remain undefined. Here, using reconstructions of in vivo labelled excitatory spiny cell and inhibitory basket cell intracortical axons combined with a variety of graph optimization algorithms, we empirically investigated Cajal's conservation laws in cerebral cortex for whole three-dimensional (3D axon arbors, to our knowledge the first study of its kind. We found intracortical axons were significantly longer than optimal. The temporal cost of cortical axons was also suboptimal though far superior to wire-minimized arbors. We discovered that cortical axon branching appears to promote a low temporal dispersion of axonal latencies and a tight relationship between cortical distance and axonal latency. In addition, inhibitory basket cell axonal latencies may occur within a much narrower temporal window than excitatory spiny cell axons, which may help boost signal detection. Thus, to optimize neuronal network communication we find that a modest excess of axonal wire is traded-off to enhance arbor temporal economy and precision. Our results offer insight into the principles of brain organization and communication in and development of grey matter, where temporal precision is a crucial prerequisite for coincidence detection, synchronization and rapid network oscillations.

  4. Teratoma with intraventricular free fat on CT

    International Nuclear Information System (INIS)

    Miura, Naohisa; Fuchinoe, Tokuro; Yahagi, Yasuji; Nakamura, Toshihiko

    1983-01-01

    Intracranial fat-containing congenital tumors are characterized by negative absorption values on computed tomography(CT). We are reporting a case of teratoma with intraventricular free fat diagnosed preoperatively by CT. The case is a 19-year-old female who was admitted to our hospital because of contineous severe headache, nausea and vomiting. At the time of admission, her physical and neurological examination was negative except for bilateral papilledema. CT demonstrated marked enlargement of the right lateral ventricle. In addition, there was negative absorption value (-90 H.U.), suggesting free fat, within right frontal horn layering above the CSF with a fluid level. Metrizamide ventriculography demonstrated complete obstruction and revealed an irregular shadow defect at the right foramen of Monro. At surgery, yellowish cheese-like material, white hair was found on the surface of the CSF. Tumor arose from the floor of the right foramen of Monro and extended upward. The patient made an uneventful recovery and was discharged 17 days after surgery. Intraventricular free fat is likely that to be released from the teratoma cyst ruptured spontaneously when the patient complained of severe headache 40 days prior to admission. There have been several published reports of the CT appearances of intracranial fat-containing tumors, however, teratoma with intraventricular free fat is very rare. It was concluded that fat-containing tumors should be highly suspected, when negative absorption values were found on CT. (author)

  5. Intraventricular metastatic clear cell renal carcinoma.

    Science.gov (United States)

    Sava, I; Sava, Anca; Şapte, Elena; Mihailov, Claudia; Dumitrescu, Gabriela; Poeată, I; Sava, Florina; Haba, Danisia

    2013-01-01

    Intraventricular tumors represent a diagnostic problem, due to a wide range of differential diagnosis, with an important variability of tumoral histological types in adult and pediatric population. Patient, Our case is represented by a patient, aged 48 years, without any history of significant personal pathology, accusing nausea, vomiting, and intensive headache. In the morning, he became confused, having hallucinations for a short period of time, and has accused drowsiness for several weeks. Imaging (CT and MRI) shows a neoformation in the third ventricle, accompanied by bilateral lateral ventricles dilatation, with predominantly annular enhancement. During surgery, through the middle third transcallosal interhemispheric approach, it was revealed a reddish, well-demarcated intraventricular mass, well vascularized and with a firm consistency. Final pathologic diagnosis was metastatic clear cell renal carcinoma. Initial postoperative evolution was good, and then neurological and respiratory condition worsened as a bronchopneumonia lead to patient's death in 12 days after surgery. Clear cell carcinoma metastasis located in the third ventricle should be taken into consideration for patients presenting a single intraventricular lesion even they have no documented primary malignancy.

  6. Relation of pace mapping QRS configuration and conduction delay to ventricular tachycardia reentry circuits in human infarct scars.

    Science.gov (United States)

    Stevenson, W G; Sager, P T; Natterson, P D; Saxon, L A; Middlekauff, H R; Wiener, I

    1995-08-01

    This study sought to determine the relation of the paced QRS configuration and conduction delay during pace mapping to reentry circuit sites in patients with ventricular tachycardia late after myocardial infarction. The QRS configuration produced by ventricular pacing during sinus rhythm (pace mapping) can locate focal idiopathic ventricular tachycardias during catheter mapping, but postinfarction reentry circuits may be relatively large and contain regions of slow conduction. We hypothesized that for postinfarction ventricular tachycardia, 1) pacing during sinus rhythm at reentry circuit sites distant from the exit from the scar would produce a QRS configuration different from the tachycardia; and 2) a stimulus to QRS delay during pace mapping may be a useful guide to reentry circuit slow conduction zones. Catheter mapping and ablation were performed in 18 consecutive patients with ventricular tachycardia after myocardial infarction. At 85 endocardial sites in 13 patients, 12-lead electrocardiograms (ECGs) were recorded during pace mapping, and participation of each site in a reentry circuit was then evaluated by entrainment techniques during induced ventricular tachycardia or by application of radiofrequency current. Pace maps resembled tachycardia at 40 ms was observed at > or = 70% of reentry circuit sites. At many sites in postinfarction ventricular reentry circuits, the QRS configuration during pace mapping does not resemble the ventricular tachycardia QRS complex, consistent with relatively large reentry circuits or regions of functional conduction block during ventricular tachycardia. A stimulus to QRS delay during pace mapping is consistent with slow conduction and may aid in targeting endocardial sites for further evaluation during tachycardia.

  7. Intraventricular Hemorrhage in Moderate to Severe Congenital Heart Disease.

    Science.gov (United States)

    Ortinau, Cynthia M; Anadkat, Jagruti S; Smyser, Christopher D; Eghtesady, Pirooz

    2018-01-01

    Determine the prevalence of intraventricular hemorrhage in infants with moderate to severe congenital heart disease, investigate the impact of gestational age, cardiac diagnosis, and cardiac intervention on intraventricular hemorrhage, and compare intraventricular hemorrhage rates in preterm infants with and without congenital heart disease. A single-center retrospective review. A tertiary care children's hospital. All infants admitted to St. Louis Children's Hospital from 2007 to 2012 with moderate to severe congenital heart disease requiring cardiac intervention in the first 90 days of life and all preterm infants without congenital heart disease or congenital anomalies/known genetic diagnoses admitted during the same time period. None. Cranial ultrasound data were reviewed for presence/severity of intraventricular hemorrhage. Head CT and brain MRI data were also reviewed in the congenital heart disease infants. Univariate analyses were undertaken to determine associations with intraventricular hemorrhage, and a final multivariate logistic regression model was performed. There were 339 infants with congenital heart disease who met inclusion criteria and 25.4% were born preterm. Intraventricular hemorrhage was identified on cranial ultrasound in 13.3% of infants, with the majority of intraventricular hemorrhage being low-grade (grade I/II). The incidence increased as gestational age decreased such that intraventricular hemorrhage was present in 8.7% of term infants, 19.2% of late preterm infants, 26.3% of moderately preterm infants, and 53.3% of very preterm infants. There was no difference in intraventricular hemorrhage rates between cardiac diagnoses. Additionally, the rate of intraventricular hemorrhage did not increase after cardiac intervention, with only three infants demonstrating new/worsening high-grade (grade III/IV) intraventricular hemorrhage after surgery. In a multivariate model, only gestational age at birth and African-American race were predictors

  8. Genes and environment in neonatal intraventricular hemorrhage.

    Science.gov (United States)

    Ment, Laura R; Ådén, Ulrika; Bauer, Charles R; Bada, Henrietta S; Carlo, Waldemar A; Kaiser, Jeffrey R; Lin, Aiping; Cotten, Charles Michael; Murray, Jeffrey; Page, Grier; Hallman, Mikko; Lifton, Richard P; Zhang, Heping

    2015-12-01

    Emerging data suggest intraventricular hemorrhage (IVH) of the preterm neonate is a complex disorder with contributions from both the environment and the genome. Environmental analyses suggest factors mediating both cerebral blood flow and angiogenesis contribute to IVH, while candidate gene studies report variants in angiogenesis, inflammation, and vascular pathways. Gene-by-environment interactions demonstrate the interaction between the environment and the genome, and a non-replicated genome-wide association study suggests that both environmental and genetic factors contribute to the risk for severe IVH in very low-birth weight preterm neonates. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Intraventricular therapy of cryptococcal meningitis via a subcutaneous reservoir.

    Science.gov (United States)

    Polsky, B; Depman, M R; Gold, J W; Galicich, J H; Armstrong, D

    1986-07-01

    Intraventricular administration of amphotericin B for meningitis due to Cryptococcus neoformans is usually reserved for selected, seriously ill patients with recurrent disease. Between September 1973 and November 1983, 10 of 23 patients treated for cryptococcal meningitis at Memorial Sloan-Kettering Cancer Center received intraventricular amphotericin B through subcutaneous reservoirs, in addition to systemic therapy. The value of intraventricular amphotericin B was assessed in the 13 patients treated for first episodes of meningitis with systemic amphotericin B and flucytosine. Death during therapy occurred in one of six patients with intraventricular and systemic therapy compared with six of seven patients with systemic therapy alone (p = 0.025). The cerebrospinal fluid was sterilized in six of six patients given systemic and intraventricular therapy compared with three of seven given systemic therapy alone (p = 0.049), and the cerebrospinal fluid cryptococcal antigen titer declined in six of six patients given systemic and intraventricular therapy compared with two of seven given systemic therapy alone (p = 0.016). In the 10 patients who received intraventricular therapy, there were no complications related to reservoir insertion; however, complications related to reservoir use requiring replacement or revision occurred in two patients, and bacterial infection occurred in one but was treated successfully without removal of the reservoir. Although these data are retrospective, they suggest that early therapy with intraventricular amphotericin B in combination with systemic therapy may be beneficial and relatively safe in patients with cryptococcal meningitis and a poor prognosis.

  10. Prevalence of conduction delay of the right atrium in patients with SSS: implications for pacing site selection.

    Science.gov (United States)

    Verlato, Roberto; Zanon, Francesco; Bertaglia, Emanuele; Turrini, Pietro; Baccillieri, Maria Stella; Baracca, Enrico; Bongiorni, Maria Grazia; Zampiero, Aldo; Zonzin, Pietro; Pascotto, Pietro; Venturini, Diego; Corbucci, Giorgio

    2007-09-01

    To evaluate the prevalence of severe right atrial conduction delay in patients with sinus node dysfunction (SND) and atrial fibrillation (AF) and the effects of pacing in the right atrial appendage (RAA) and in the inter-atrial septum (IAS). Forty-two patients (15 male, 72 +/- 7 years) underwent electrophysiologic study to measure the difference between the conduction time from RAA to coronary sinus ostium during stimulation at 600 ms and after extrastimulus (DeltaCTos). Patients were classified as group A if DeltaCTos > 60 ms and group B if IAS pacing and algorithms ON/OFF. Fifteen patients (36%, group A) had DeltaCTos = 76 +/- 11 ms and 27 patients (64%, group B) had DeltaCTos = 36 +/- 20 ms. Twenty-two patients were paced at the RAA and 20 at the IAS. During the study, no AF recurrences were reported in 11 of 42 (26%) patients, independently of RAA or IAS pacing. Patients from group A and RAA pacing had 0.79 +/- 0.81 episodes of AF/day during DDD, which increased to 1.52 +/- 1.41 episodes of AF/day during DDDR + Alg (P = 0.046). Those with IAS pacing had 0.5 +/- 0.24 episodes of AF/day during DDD, which decreased to 0.06 +/- 0.08 episodes of AF/day during DDDR + Alg (P = 0.06). In group B, no differences were reported between pacing sites and pacing modes. Severe right atrial conduction delay is present in one-third of patients with SND and AF: continuous pacing at the IAS is superior to RAA for AF recurrences. In patients without severe conduction delay, no differences between pacing site or mode were observed.

  11. Evaluation of Intraventricular Hemorrhage in Pediatric Intracerebral hemorrhage

    Science.gov (United States)

    Kleinman, Jonathan T; Beslow, Lauren A; Engelmann, Kyle; Smith, Sabrina E; Licht, Daniel J; Ichord, Rebecca N; Jordan, Lori C

    2012-01-01

    Previous studies of pediatric intracerebral hemorrhage have investigated isolated intraparenchymal hemorrhage. We investigated whether detailed assessment of intraventricular hemorrhage enhanced outcome prediction after intracerebral hemorrhage. We prospectively enrolled 46 children, full-term to 17 years, median age 2.7 years with spontaneous intraparenchymal hemorrhage and/or intraventricular hemorrhage. Outcome was assessed with the King’s Outcome Scale for Childhood Head Injury. Twenty-six (57%) had intraparenchymal hemorrhage, 10 (22%) had pure intraventricular hemorrhage, and 10 (22%) had both. There were 2 deaths, both with intraparenchymal hemorrhage + intraventricular hemorrhage volume ≥4% of total brain volume. Presence of intraventricular hemorrhage was not associated with poor outcome, but hydrocephalus showed a trend (p=0.09) toward poor outcome. In receiver operating characteristic curve analysis, combined intraparenchymal hemorrhage + intraventricular hemorrhage volume also showed a trend toward better outcome prediction than intraparenchymal hemorrhage volume alone. Although not an independent outcome predictor, future studies should assess intraventricular hemorrhage qualitatively and quantitatively. PMID:22068828

  12. Criteria for intraventricular conduction disturbances and pre-excitation

    NARCIS (Netherlands)

    Willems, J.L.; Robles de Medina, E.O.; Bernard, R.; Coumel, Ph.; Fisch, Ch.; Mazur, N.A.; Meijler, F.L.; Mogensen, L.; Moret, P.; Pisa, Z.; Rautaharju, P.M.; Surawicz, B.; Watanabe, Y.; Wellens, H.J.J.; WHO/ISFC Task Force ad hoc

    1985-01-01

    In an effort to standardize terminology and criteria for clinical electrocardiography, and as a follow-up of its work on definitions of terms related to cardiac rhythm, an Ad Hoc Working Group established by the World Health Organization and the International Society and Federation of Cardiology

  13. Computed tomographic investigations on intraventricular hematomas

    International Nuclear Information System (INIS)

    Laber-Szillat, S.

    1982-01-01

    This work investigated in 106 patients with intraventricular hematomas all the known factors which can have an influence on prognosis: age, sex, anamnesis of the patients, size, extent and localization of the intracranial bleeding, underlying angiopathy and differences between arterial and venous and spontaneous and traumatic bleedings. It was shown that the state of mind was the deciding prognostic factor, whereby viligance was the cumulative expression of all other investigated influences. A computed tomography (CT) examination is deciding in the question of operative hydrocephalus care. In 13 patients it was further shown, how clearly CT results and brain dissection allowed themselves to be compared. The computed tomographic examination method is best suited to achieve even physiological and more extensive prognostic possibilities. (orig.) [de

  14. CLINICAL AND MORPHOLOGICAL CLASSIFICATION OF CEREBRAL INTRAVENTRICULAR HEMORRHAGES

    Directory of Open Access Journals (Sweden)

    V. V. Vlasyuk

    2013-01-01

    Full Text Available Inconsistency of the current classification of cerebral intraventricular hemorrhages is discussed in the article. The author explains divergence of including of the subependymal (1st stage and intracerebral (4th stage hemorrhages into this classification. A new classification of cerebral intraventricular hemorrhages including their origin, phases and stages is offered. The most common origin of intraventricular hemorrhages is subependymal hemorrhage (82,2%. Two phases of hemorrhage were distinguished: bleeding phase and resorption phase. Stages of intraventricular hemorrhages reflecting the blood movement after the onset of bleeding are the following: 1 — infill of the up to ½ of the lateral ventricles without their enlargement; 2 — infill of more than ½ of the lateral ventricles with their enlargement; 3 — infill of the IV ventricle, of the cerebellomedullary cistern and its dislocation into the subarachnoid space of the cerebellum, pons varolii, medulla oblongata and spinal cord.

  15. Ventricular Zone Disruption in Human Neonates With Intraventricular Hemorrhage

    NARCIS (Netherlands)

    McAllister, James P.; Guerra, Maria Montserrat; Ruiz, Leandro Castaneyra; Jimenez, Antonio J.; Dominguez-Pinos, Dolores; Sival, Deborah; den Dunnen, Wilfred; Morales, Diego M.; Schmidt, Robert E.; Rodriguez, Esteban M.; Limbrick, David D.

    2017-01-01

    To determine if ventricular zone (VZ) and subventricular zone (SVZ) alterations are associated with intraventricular hemorrhage (IVH) and posthemorrhagic hydrocephalus, we compared postmortem frontal and subcortical brain samples from 12 infants with IVH and 3 nonneurological disease controls

  16. Evaluation of Intraventricular Hemorrhage in Pediatric Intracerebral hemorrhage

    OpenAIRE

    Kleinman, Jonathan T; Beslow, Lauren A; Engelmann, Kyle; Smith, Sabrina E; Licht, Daniel J; Ichord, Rebecca N; Jordan, Lori C

    2011-01-01

    Previous studies of pediatric intracerebral hemorrhage have investigated isolated intraparenchymal hemorrhage. We investigated whether detailed assessment of intraventricular hemorrhage enhanced outcome prediction after intracerebral hemorrhage. We prospectively enrolled 46 children, full-term to 17 years, median age 2.7 years with spontaneous intraparenchymal hemorrhage and/or intraventricular hemorrhage. Outcome was assessed with the King’s Outcome Scale for Childhood Head Injury. Twenty-si...

  17. Patient-Specific Modeling of Intraventricular Hemodynamics

    Science.gov (United States)

    Vedula, Vijay; Marsden, Alison

    2017-11-01

    Heart disease is the one of the leading causes of death in the world. Apart from malfunctions in electrophysiology and myocardial mechanics, abnormal hemodynamics is a major factor attributed to heart disease across all ages. Computer simulations offer an efficient means to accurately reproduce in vivo flow conditions and also make predictions of post-operative outcomes and disease progression. We present an experimentally validated computational framework for performing patient-specific modeling of intraventricular hemodynamics. Our modeling framework employs the SimVascular open source software to build an anatomic model and employs robust image registration methods to extract ventricular motion from the image data. We then employ a stabilized finite element solver to simulate blood flow in the ventricles, solving the Navier-Stokes equations in arbitrary Lagrangian-Eulerian (ALE) coordinates by prescribing the wall motion extracted during registration. We model the fluid-structure interaction effects of the cardiac valves using an immersed boundary method and discuss the potential application of this methodology in single ventricle physiology and trans-catheter aortic valve replacement (TAVR). This research is supported in part by the Stanford Child Health Research Institute and the Stanford NIH-NCATS-CTSA through Grant UL1 TR001085 and partly through NIH NHLBI R01 Grant 5R01HL129727-02.

  18. ''Intraventricular'' hemorrhage and cystic periventricular leukomalacia in preterm infants: how are they related?

    NARCIS (Netherlands)

    Kusters, C.D.J.; Chen, M.L.; Follett, P.L.; Dammann, O.

    2009-01-01

    Intraventricular hemorrhage and cystic periventricular leukomalacia are often co-occurring characteristics of brain damage in preterm infants. Using data from 1016 infants born before 30 completed weeks' gestational age, we sought to clarify the relationship between severe intraventricular

  19. Periventricular-intraventricular haetnorrhage in low-birth-weight ...

    African Journals Online (AJOL)

    JAN 1994. Periventricular-intraventricular haetnorrhage in low-birth-weight infants at Baragwanath Hospital ... dation,IO while many women delivering premature infants have not received proper antenatal care. .... required mechanical ventilation and one-third of those who did not, allocated by random number generation,.

  20. Clinical aspects and prognosis of intraventricular hemorrhage with cerebrovascular disease

    International Nuclear Information System (INIS)

    Ikeda, Yukio; Nakazawa, Shozo; Higuchi, Hiroshi; Ueda, Kenji; Kouzo

    1982-01-01

    Intraventricular hemorrhage with cerebrovascular disease was identified in 81 cases and death occurred within seven days in 34 cases. Hypertension was the most common etiological factor, accounting for 40 of the 81 cases. Cerebral aneurysm was the second most common cause accounting for 27 cases, arteriovenous malformation accounted for 9 of the cases, and 5 were of other causes. Signs of primary or secondary brain stem dysfunction were mainly seen in cases with hypertension and aneurysm, while cases with arteriovenous malformation had benign courses. The mortality depended on the severity of intraventricular hemorrhage; i.e., the distribution, site, and the number of cast formation. The presence of intraventricular clot in the third and/or fourth ventricles was correlated with a high mortality rate, especially in cases accompanied by cast formation and third and fourth ventricular dilatation, which affects hypothalamus and brain stem function. Analysis of CT findings for the mechanism of intraventricular hemorrhage revealed three types: extension type, in which massive intracerebral hematomas extended and ruptured into ventricles; the direct type, which bled directly into ventricles without forming definite intracerebral hematomas; and the reflux type, which was characterized by reflux of the subarachnoid blood. (J.P.N.)

  1. Periventricular-intraventricular haemorrhage in low-birth-weight ...

    African Journals Online (AJOL)

    The prevalence of periventricular-intraventricular haemorrhage (PV-IVH) aInong very-low-birthweight infants at Baragwanath Hospital has not been well docwnented. In this prospective study, a total of 282 live-born infants with birth weights of 1 000 - 1 749 g were studied over a 41/2-month period. Every infant had at least ...

  2. Prenatal intraventricular hemorrhage in a term infant with congenital ...

    African Journals Online (AJOL)

    Intraventricular hemorrhage (IVH) occurs rarely in term infant, since subependymal area is a transient structure in fetal life. IVH in term infant indicates generally that it happened prenatally. Congenital cytomegalovirus (CMV) infection is frequent, occurring in 1% of live births. It is a severe infection leading to developmental ...

  3. Pharmacokinetics of intraventricularly administered teicoplanin in Staphylococci ventriculitis

    NARCIS (Netherlands)

    Beenen, L. F.; Touw, D. J.; Hekker, T. A.; Haring, D. A.

    2000-01-01

    Following craniotomy for a medulloblastoma in the posterior cranial fossa, a 6-year old girl developed a ventriculitis with coagulase negative staphylococci associated with the use of a ventriculostomy. Treatment with intravenous (i.v.) and intraventricular (ivt) vancomycin resulted in negative

  4. Pharmacokinetics of intraventricularly administered teicoplanin in Staphylococci ventriculitis

    NARCIS (Netherlands)

    Beenen, L F; Touw, D J; Hekker, T A; Haring, D A

    Following craniotomy for a medulloblastoma in the posterior cranial fossa, a 6-year old girl developed a ventriculitis with coagulase negative staphylococci associated with the use of a ventriculostomy. Treatment with intravenous (i.v.) and intraventricular (ivt) vancomycin resulted in negative

  5. Magnetic resonance imaging (MRI) of an intraventricular hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Ryungchan; Higashi, Tooru; Ito, Shotaro; Kadoya, Satoru; Takarada, Akira; Sato, Shuji; Kurauchi, Manabu.

    1987-08-01

    The utility of MRI was investigated in 10 patients with intraventricular hemorrhage. MRI was found to be, in many respects, superior to CT: 1) MRI is able to detect to some extent the aging of an intraventricular hematoma. 2) It can determine the character of intraventricular cerebrospinal fluid, whether it is normal, bloody, or hyperprotein. 3) It can detect the cause of hemorrhage in the case of arterio-venous malformation. 4) MRI permits the detection of the penetration course and the location of a ventricular hematoma. 5) It can clearly detect periventricular lesions of early-stage hydrocephalus, accompanied by increased intracranial pressure and followed by intraventricular hemorrhage, by imaging the periventricular high-signal-intensity area. 6) MRI can clearly diagnose complications of intracranial lesions. For instance, it can distinguish subdural fluid collection from chronic subdural hematoma and can detect whether a cerebral infarction is new or old. On the other hand, MRI also has some disadvantages: 1) The imaging time is long, and clinical application is difficult, in serious and/or infant cases. 2) It is impossible to use MRI in some patients who have magnetic material in their bodies. 3) The spatial-image resolution is not good.

  6. Hemorragia intraventricular en el neonato prematuro Intraventricular hemorrage in preterm infants

    Directory of Open Access Journals (Sweden)

    José William Cornejo Ochoa

    2005-01-01

    Full Text Available La hemorragia intraventricular (HIV es la principal complicación neurológica en los prematuros; consiste en sangrado de la matriz germinal y las regiones periventriculares del cerebro. Su frecuencia y gravedad aumentan en la medida en que es menor el peso al nacimiento; se la halla entre 10 y 20% de los neonatos de 1.000-1.500 gramos y hasta en 70% en los menores de 700 gramos; se presenta en 85% de las veces en las primeras 72 horas posparto y en 95% ya es evidente al finalizar la primera semana; son múltiples los factores maternos y fetales que se han encontrado asociados con el aumento o disminución de su frecuencia, además del uso de algunos medicamentos. Se han propuesto diversos mecanismos fisiopatogénicos asociados a la inmadurez neurológica para explicar la aparición de la HIV. Las manifestaciones clínicas son variables en cuanto a presentación y evolución. La confirmación diagnóstica, la clasificación y el pronóstico se basan en la ecografía transfontanelar. La principal medida preventiva es la disminución de la frecuencia del parto prematuro; los resultados de otras medidas como el uso prenatal y posnatal de algunos medicamentos para evitarla y tratarla han sido variables. El pronóstico depende de la extensión de la hemorragia, del desarrollo de leucomalacia periventricular y del grado de dilatación ventricular. Neonatal intraventricular hemorrage (IVH is the main neurological complication in preterm infants involving bleeding into the germinal matrix and the periventricular brain areas. Its incidence and severity are greater with lower birthweigth: from 10-20% in 1.000-1.500 g babies to 70% in those less than 700 g. Most often (85% it appears during the first 72 hours after birth and almost 95% of the cases are evident by the end of the first week of life. Many maternal and fetal risk factors are associated with the risk of neonatal IVH. Diferent pathogenic mechanisms associated with an immature central nervous

  7. A Tutorial on the Use of Excel 2010 and Excel for Mac 2011 for Conducting Delay-Discounting Analyses

    Science.gov (United States)

    Reed, Derek D.; Kaplan, Brent A.; Brewer, Adam T.

    2012-01-01

    In recent years, researchers and practitioners in the behavioral sciences have profited from a growing literature on delay discounting. The purpose of this article is to provide readers with a brief tutorial on how to use Microsoft Office Excel 2010 and Excel for Mac 2011 to analyze discounting data to yield parameters for both the hyperbolic…

  8. Pilocytic astrocytoma: A rare presentation as intraventricular tumor

    Science.gov (United States)

    Sattar, Sidra; Akhunzada, Naveed Z.; Javed, Gohar; Uddin, Zeeshan; Khan, Yasir A.

    2017-01-01

    Background: Pilocytic astrocytoma (PA) is the most prevalent central nervous system (CNS) tumor in pediatric population and accounts for an approximate of 5–6% of all gliomas. This neoplasm can occur at all levels of the neuraxis, with majority (67%) arising in the cerebellum and optic pathway. PAs are World Health Organization Grade I tumors and are the most benign of all astrocytomas characterized by an excellent prognosis. Other differentials include subependymal giant cell astrocytoma (SEGA), ependymoma, meningioma, and low-grade gliomas such as pilocytic or diffuse astrocytoma; calcification is more commonly regarded as a feature of benign or slow-growing tumors. Case Description: We present a case of a 17-year-old female presenting with an unusual cause of hydrocephalus, a rare case of a calcified pilocytic astrocytoma as an intraventricular tumor. Conclusion: PA rarely presents as an intraventricular tumor and should be included in the differential diagnosis of a large mass with massive intratumoral calcification. PMID:28680735

  9. Recurrent Candida albicans Ventriculitis Treated with Intraventricular Liposomal Amphotericin B

    Directory of Open Access Journals (Sweden)

    Demet Toprak

    2015-01-01

    Full Text Available Central nervous system (CNS infection with Candida is rare but significant because of its high morbidity and mortality. When present, it is commonly seen among immunocompromised and hospitalized patients. Herein, we describe a case of a four-year-old boy with acute lymphoblastic leukemia (ALL who experienced recurrent Candida albicans meningitis. The patient was treated successfully with intravenous liposomal amphotericin B at first attack, but 25 days after discharge he was readmitted to hospital with symptoms of meningitis. Candida albicans was grown in CFS culture again and cranial magnetic resonance imaging (MRI showed ventriculitis. We administered liposomal amphotericin B both intravenously and intraventricularly and favorable result was achieved without any adverse effects. Intraventricular amphotericin B may be considered for the treatment of recurrent CNS Candida infections in addition to intravenous administration.

  10. Unusual presentation of hydatid cyst – ruptured intraventricular hydatid

    Directory of Open Access Journals (Sweden)

    Sneha H Thakur

    2017-01-01

    Full Text Available Echinococcosis in humans occurs as a result of infection by the larval stages of taenid cestodes of the genus Echinococcus. Most of the intracranial hydatids develop in brain parenchyma. Hydatid cyst within the cerebral ventricle is quite unusual. Literature review showed few case reports of childhood as well as adult intraventricular hydatid cysts. None of these cases presented for the first time with features of ruptured intraventricular cyst. This is a very rare presentation of a common disease. The possibility of infestation with E. granulosus should be included in the differential diagnosis of raised intracranial tension in patients reporting from endemic areas, because the prognosis following surgical intervention is excellent, especially in the pediatric age group.

  11. Mechanisms of Hydrocephalus after Neonatal and Adult Intraventricular Hemorrhage

    OpenAIRE

    Strahle, Jennifer; Garton, Hugh J.L.; Maher, Cormac O.; Muraszko, Karin M.; Keep, Richard F.; Xi, Guohua

    2012-01-01

    Intraventricular hemorrhage (IVH) is a cause of significant morbidity and mortality and is an independent predictor of a worse outcome in intracerebral hemorrhage (ICH) and germinal matrix hemorrhage (GMH). IVH may result in both injuries to the brain as well as hydrocephalus. This paper reviews evidence on the mechanisms and potential treatments for IVH-induced hydrocephalus. One frequently cited theory to explain hydrocephalus after IVH involves obliteration of the arachnoid villi by microt...

  12. Successful neuroendoscopic treatment of intraventricular brain abscess rupture

    Directory of Open Access Journals (Sweden)

    Takafumi Nishizaki

    2011-07-01

    Full Text Available Intraventricular rupture of a brain abscess is still associated with a high mortality rate. Here, we report such a case in a patient with normal immunity that was treated successfully using neuroendoscopic approach. A 69-yearold man who had presented with headache and fever developed confusion and restlessness. Magnetic resonance imaging revealed a mass with ring enhancement extending to the right ventricle. Emergency aspiration of cerebrospinal fluid (CSF from the spinal canal revealed severe purulent meningitis. Bacterial culture of the CSF and blood was negative. Because of prolonged consciousness disturbance, the patient underwent evacuation of the intraventrcular abscess using a neuroendoscope. The pus was centrifuged and collected for bacterial culture, and this revealed Streptococcus intermedius/milleri. After implantation of a ventricular catheter, gentamicin sulfate was administered twice a day for 9 days. Cefotaxime sodium was also administered intravenously for 14 days, followed by oral administration of cefcapene pivoxil hydrochloride for 10 days. The patient made a complete recovery, and was discharged 31 days after admission. After 20 months of follow-up, he is doing well and has returned to his work. In cases of intraventricular rupture of a brain abscess, a neuroendoscopic approach is useful for evacuation of intraventricular debris or septum, and identification of the causative bacterium for selection of antibiotics, possibly reducing the period of hospitalization.

  13. The intraventricular filling vortex under heightened aortic blood pressure

    Science.gov (United States)

    Nelsen, Nicholas; Gaddam, Manikantam; Santhanakrishnan, Arvind

    2017-11-01

    Hypertension, or high aortic blood pressure, can induce structural changes in the left ventricle (LV) such as concentric hypertrophy. Previous studies have identified that the intraventricular filling vortex serves as an effective means of blood transport during diastolic filling. However, a fundamental understanding of how hypertension affects this vortex is unavailable. This knowledge can be useful for improving diagnosis and treatment of related heart disease conditions, including hypertensive heart failure. In this experimental study, we hypothesized that the circulation of the filling vortex would diminish with increased aortic pressure. Using a LV physical model within a left heart simulator, we performed hemodynamic measurements to acquire pressure and volumetric inflow profiles and 2D particle image velocimetry to visualize the intraventricular flow fields. Peak aortic pressures of 120 mm Hg, 140 mm Hg, and 160 mm Hg were each tested at heart rates of 70, 100, and 110 beats per minute, under: 1) reduced ejection fraction (EF), and 2) constant EF. Our results indicate that peak vortex circulation is reduced under elevated aortic pressures. Hemodynamics and characteristics of the intraventricular filling vortex in all examined experimental cases will be presented.

  14. Intraventricular tuberculoma. Report of four cases in children. [CT scan findings described

    Energy Technology Data Exchange (ETDEWEB)

    Berthier, M.; Sierra, J.; Leiguarda, R.

    1987-03-01

    Four cases of intraventricular tuberculoma (IVT) in children are here reported. In none of the patients was there clinical evidence pointing to the intraventricular location. CT scan findings comprised three stages of development, namely: immature, mature and old. Ependymal attachment and asymmetric hydrocephalus were present in three cases, meningitis in two and ependymitis in one. Septum pellucidum traction was clearly observed in two patients, strongly supporting an adhesive process characteristic of intraventricular tuberculosis. Following specific treatment, the tuberculomas remitted partially or entirely.

  15. Antecedents of perinatal cerebral white matter damage with and without intraventricular hemorrhage in very preterm newborns.

    Science.gov (United States)

    Logan, J Wells; Westra, Sjirk J; Allred, Elizabeth N; O'Shea, T Michael; Kuban, Karl; Paneth, Nigel; Leviton, Alan

    2013-08-01

    Isolated periventricular leukomalacia, defined as periventricular leukomalacia unaccompanied by intraventricular hemorrhage, is reportedly increased in newborns with systemic hypotension and in infants who received treatment for systemic hypotension or a patent ductus arteriosus. This study sought to determine if the risk profile of one or more hypoechoic lesions unaccompanied by intraventricular hemorrhage, our surrogate for isolated periventricular leukomalacia, differs from that of one or more hypoechoic lesions preceded or accompanied by intraventricular hemorrhage. We compared extremely preterm infants (i.e., gestation 23-27 weeks) with each of these entities to 885 extremely preterm infants who had neither an isolated hypoechoic lesion nor a hypoechoic lesion preceded or accompanied by intraventricular hemorrhage. The risk of a hypoechoic lesion with intraventricular hemorrhage (N = 61) was associated with gestation Acute Neonatal Physiology, early recurrent or prolonged acidemia, analgesic exposure, and mechanical ventilation 1 week after birth. In this large, multicenter sample of extremely low gestational age newborns, the risk profile of a hypoechoic lesion unaccompanied by intraventricular hemorrhage differed from that of a hypoechoic lesion with intraventricular hemorrhage. This suggests that hypoechoic lesions accompanied or preceded by intraventricular hemorrhage (our surrogate for periventricular hemorrhagic infarction) may have a different causal pathway than hypoechoic lesions without intraventricular hemorrhage, our surrogate for periventricular leukomalacia. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Perfusion monitoring and intraventricular hemorrhage in preterm infants.

    Science.gov (United States)

    Ishiguro, Akio

    2017-07-01

    Cardiovascular instability in preterm infants during the early postnatal period correlates with the development of intraventricular hemorrhage (IVH). Due to the correlation between hypotension and fluctuation of blood pressure, treatment was targeted specifically at hypotension to prevent IVH, but this was not successful. Recently, several novel perfusion markers have been found to be correlated with the development of IVH, and they are of current interest in cardiovascular management. In this review, the correlation between IVH and conventional, as well as novel, perfusion markers is examined. © 2017 Japan Pediatric Society.

  17. A case report on subarachnoid and intraventricular neurocysticercosis

    Directory of Open Access Journals (Sweden)

    Chen Shang

    2015-01-01

    Full Text Available Neurocysticercosis is the most common central nervous system helminthic infection in humans. We hereby present a case combining two rare manifestations of neurocysticercosis: the subarachnoid and intraventricular forms. The patient presented with hydrocephalus and neurologic deficits and although endoscopic removal of the cysts and two cycles of postoperative cysticidal drugs resulted in resolution of symptoms, they later recurred. Ventriculoperitoneal shunt placement and a further cycle of albendazole plus dexamethasone led to substantial clinical improvement. Extraparenchymal neurocysticercosis may be challenging to diagnose and treat and is usually associated with a poorer prognosis. Clinicians should be aware of this condition.

  18. Minimizing ventricular pacing by a novel atrioventricular (AV) delay hysteresis algorithm in patients with intact or compromised intrinsic AV conduction and different atrial and ventricular lead locations.

    Science.gov (United States)

    Pakarinen, Sami; Toivonen, Lauri

    2013-09-01

    To investigate if an advanced AV search hysteresis (AVSH) algorithm, Ventricular Intrinsic Preference (VIP(™)), reduces the incidence of ventricular pacing (VP) in sinus node dysfunction (SND) with both intact and compromised AV conduction and with intermittent AV block regardless of the lead positions in the right atria and the ventricle. Patients were classified as having intact AV (AVi) conduction if the PR interval was ≤ 210 ms on ECG and 1:1 AV conduction during atrial pacing up to 120 bpm with PR interval ≤ 350 ms. Otherwise the AV conduction was classified as compromised (AVc). Both AVi and AVc patients were randomized to VIP ON or OFF. VIP performed an intrinsic AV conduction search every 30 s for three consecutive atrial cycles with the extension of the sensed and paced AV (SAV/PAV) delays from basic values of 150/200 ms to 300/350 ms. Extended AV intervals were allowed for three cycles when VP occurred before returning to basic AV delays. The primary end-point was %VP at 12 months. Among 389 patients, 30.1% had intact and 69.9% had compromised AV conduction. The mean %VP at 12 months was 9.6% by VIP compared to 51.8% with standard AV settings in patients with AVi (P < 0.0001) and 28.0% versus 78.9% (P < 0.0001) with AVc. With VIP, excessive %VP among most used lead positions was not seen. Conversely, when VIP was off %VP was low only in patients who had leads in the RA septal-RV septal position (23.0%). VIP feature reduces VP both in patients with SND and with intermittent heart block regardless of the lead positions in the right atria and the ventricle.

  19. Developmental Outcome of Preterm Infants with Intraventricular Hemorrhage at One and Two Years of Age.

    Science.gov (United States)

    Sostek, Anita Miller; And Others

    1987-01-01

    This study examined developmental outcome at 1 and 2 years in relation to the presence and severity of neonatal intraventricular hemorrhage. Intraventricular hemorrhage related to Bayley mental and motor scores and neurologic ratings at 1 year but not at 2 years. Significant associations were found between the 1- and 2-year measures but not…

  20. Altered expressions of endothelial junction protein of placental capillaries in premature infants with intraventricular hemorrhage

    Directory of Open Access Journals (Sweden)

    Maria Ekawati

    2016-10-01

    Full Text Available Background: Placental hypoxia may lead to oxidative stress, which inflicts damage to capillary protein junction. The aim of this study was to evaluate altered expression of endothelial junction protein of capillaries in hypoxia condition and to observe its correlation with the incidence of  intraventricular hemorrhage in premature infants.Methods: A cross-sectional study was conducted by using placental tissues of premature infants as amodel of capillary integrity (29 hypoxic and 29 non-hypoxic. Hypoxia inducible factor (HIF-1α was measured to define placental tissue response to hypoxia; malondialdehyde (MDA and glutathione (GSH served as markers of oxidative stress. The expressions of junctional proteins, N-cadherin and occludin were analyzed by immunohistochemistry. Intraventricular hemorrhage (IVH was detected by cranial ultrasound at the third day. Unpaired t test, Mann-Whitney, and Chi-square tests were used to analyze the data.Results: The HIF-1α and MDA levels were slightly, but not significantly, higher in hypoxia group {13.64±8.70 pg/mg protein and 10.31 pmol/mg tissue (ranged 1.92–93.61, respectively}  compared to non- hypoxia group {10.65±5.35 pg/mg protein and 9.77 pmol/mg tissue (ranged 2.42–93.31}. GSH levels were not different in both groups (38.14 (ranged 9.44–118.91 and  38.47(ranged 16.49–126.76 ng/mg protein, respectively. mRNA expression of N-cadherin (0.13 and occludin (0.096 were significantly lower in hypoxia comparedto non-hypoxia group (p=0,001, while protein expression of  N-cadherin (3.4; 75.9; 6.9; 13.8% and occludin  (20.7; 3.4; 69.0; 3.4; 6.9%  in hypoxia group was not associated with IVH (p=0.783 and p=0.743.Conclusion: Hypoxia altered expression of endothelial junction protein in placental capillaries, but no association with intraventricular hemorrhage was observed.

  1. [Twin pregnancy as the risk factor for neonatal intraventricular hemorrhage].

    Science.gov (United States)

    Wieczorek, Aleksandra I; Krasomski, Grzegorz

    2015-02-01

    The aim of this study was to find the perinatal risk factors of intravenricular hemorrhage in twin neonates. A retrospective analysis of 203 twin pregnancies and deliveries between 2003 and 2009 was performed. Then data according birth state and neonatal complications in 406 twins were analyzed. Twin outcome was compared with the outcome of 105 singletons born at the same time and at the same gestational age as twins. Intraventricular hemorrhage was diagnosed in 116/406 (29%) of twins. IVH was found two times more often in the analyzed group than in singletons born at the same gestational age (29% vs. 18%, p = 0,03). In 96% I and II grade hemorrhage was diagnosed and in 4% III and IV grade hemorrhage in the Papille scale was found. 1) Intraventricular hemorrhage is found more often in twins than in singleton neonates born at the same gestational age. 2) IVH in twins correlate with preterm birth and low birth weight. IVH occur more often in twins with birth weight discordance and with too small maternal weight gain.

  2. Intraventricular Hemorrhage after Epidural Blood Patching: An Unusual Complication

    Directory of Open Access Journals (Sweden)

    Mohammad Sorour

    2014-01-01

    Full Text Available The authors present two cases of intraventricular hemorrhage (IVH believed to be a result of epidural blood patching. The first was a 71-year-old woman who had new onset of nontraumatic IVH on computed tomography (CT scan after undergoing an epidural blood patch (EBP. This amount of intraventricular blood was deemed an incidental finding since it was of very small volume to account for her overall symptoms. The second patient, a 29-year-old woman, was found to have nontraumatic IVH three days after undergoing an EBP. This was seen on CT scan of the head for workup of pressure-like headaches, nausea, vomiting, and absence seizures. Conservative management was followed in both instances. Serial CT scan of the head in our first patient displayed complete resolution of her IVH. The second patient did not have follow-up CT scans because her overall clinical picture had improved significantly. This highlights a potential sequel of EBP that may be observed on CT scan of the head. In the event that IVH is detected, signs and symptoms of hydrocephalus should be closely monitored with the consideration for a future workup if warranted by the clinical picture.

  3. Intracerebral Hemorrhage with Intraventricular Extension—Getting the Prognosis Right Early

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    Christoph Stretz

    2017-08-01

    Full Text Available BackgroundEarly accurate outcome prognostication for patients with intracerebral hemorrhage (ICH and accompanying intraventricular hemorrhage (IVH is often challenging (1. Acute hydrocephalus often contributes to a poor clinical exam (2 and can portend significant morbidity and mortality (3. Accordingly, the inpatient neurologist may feel inclined to recommend limitations of care for an ICH patient admitted with a large IVH burden and poor exam.Case presentationWe present a patient with significant IVH and minimal ICH who deteriorated rapidly to coma after presentation. Despite this exam, an initially non-functioning diversion of cerebrospinal fluid (CSF and temporary halt of further attempts of CSF diversion in the setting of an early “do not resuscitate order,” our patient gradually improved and, with supportive ICU care and rehabilitation, was able to communicate and ambulate with assistance at 12 weeks.ConclusionPatients with ICH with IVH do have the capacity to improve dramatically even with relatively conservative management. Unless previous limitations of care exist, we recommend that early judgments of prognosis for patients with ICH and/or IVH should be delayed for at least 72 h until the patient’s clinical trajectory over time is better understood.

  4. Circulatory Management Focusing on Preventing Intraventricular Hemorrhage and Pulmonary Hemorrhage in Preterm Infants

    Directory of Open Access Journals (Sweden)

    Bai-Horng Su

    2016-12-01

    Full Text Available The goal of modern neonatal care of extremely preterm infants is to reduce mortality and long-term neurological impairments. Preterm infants frequently experience cerebral intraventricular or pulmonary hemorrhage, which usually occurs within 72 hours after birth and can lead to long-term neurological sequelae and mortality. These serious hemorrhagic complications are closely related to perinatal hemodynamic changes, including an increase in the afterload on the left ventricle of the heart after the infant is separated from the placenta, and an increased preload from a left-to-right shunt caused by a hemodynamically significant patent ductus arteriosus (PDA. The left ventricle of a preterm myocardium has limited ability to respond to such an increase in afterload and preload, and this can result in cardiac dysfunction and hemodynamic deterioration. We suggest that delayed umbilical cord clamping or umbilical cord milking to maintain optimal blood pressure and systemic blood flow (SBF, careful assessment to keep the afterload at an acceptable level, and a strategy of early targeted treatment of significant PDA to improve perfusion during this critical time period may reduce or prevent these serious complications in preterm infants.

  5. Analysis of angiographic findings in cerebral arteriovenous malformation with hemorrhage: comparison between intracerebral and intraventricular hemorrhage

    International Nuclear Information System (INIS)

    Kim, Jae Kyun; Kim, Joon Hyung; Kwon, Jin Sook; Yoon, Soo Woong; Lee, Ho Kyu; Choi, Choong Gon; Suh, Dae Chul

    1998-01-01

    The purpose of this study was to analyze the angioarchitectures of cerebral arteriovenous malformation (AVM) and to determine whether there was correlation between angioarchitectures and patterns of intracranial hemorrhage (intracerebral, intraventricular, and both) in cerebral AVM. One hundred and twenty-eight patients who between November 1989 and December 1994 suffered supratentorial AVM with intracranial hemorrhage were studied retrospectively. Among 128 patients, intracerebral and intraventricular hemorrhage were seen in 68(53%) and 24 patients(19%), respectively, while both types were seen in the remaining 36 (28%). We analyzed the angioarchitectual characteristics of AVM, namely nidi, feeding arteries and draining veins, in three hemorrhagic groups of patients with intracerebral hemorrhage, intraventricular hemorrhage and both. The X 2 test or Fisher's exact test was used for statistical analysis. A cortically located nidus was most common in patients with intracerebral hemorrhage, while a periventricular location was most common in those with intraventricular hemorrhage (p<0.001). Location in the corpus callosum, choroid plexus, or intraventricular area was more frequent in the intraventricular than the intracerebral hemorrhagic group (p<0.05). Superficial venous drainage was most common in patients with intracerebral hemorrhage (p<0.001), and deep venous drainage in those with intraventricular hemorrhage (p=3D0.001). The angioarchitectual characteristics of cerebral arteriovenous malformation correlate significantly with patterns of intracranial hemorrhage, and awareness of the type of hemorrhage could help to manage patients and determine prognosis.=20

  6. [Giant racemose subarachnoid and intraventricular neurocysticercosis: A case report].

    Science.gov (United States)

    Sanchez-Larsen, Alvaro; Monteagudo, Maria; Lozano-Setien, Elena; Garcia-Garcia, Jorge

    2015-01-01

    Neurocysticercosis is the most frequent parasitic disease of the central nervous system. It is caused by the larvae of Taenia solium, which can affect different anatomical sites. In Spain there is an increasing prevalence mainly due to immigration from endemic areas. The extraparenchymal forms are less common, but more serious because they usually develop complications. Neuroimaging plays a major role in the diagnosis and follow-up of this disease, supported by serology and a compatible clinical and epidemiological context. First-line treatments are cysticidal drugs such as albendazole and praziquantel, usually coadministered with corticosteroids, and in some cases surgery is indicated. We here report a case of neurocysticercosis with simultaneous intraventricular and giant racemose subarachnoid involvement. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Pituitary apoplexy presenting as an intraventricular hemorrhage: An infrequent neurovascular emergency

    Directory of Open Access Journals (Sweden)

    Gabriel Torrealba-Acosta, MD

    2017-12-01

    Full Text Available Pituitary macroadenomas may present with a pituitary apoplexy, commonly with associated hemorrhage, but rarely large enough to show an intraventricular bleeding. This is a case report of a 66-year-old woman with a 3-month history of headache, hyporexia, asthenia and altered consciousness. First evaluations showed a large intraventricular hemorrhage on CT scan that was initially misdiagnosed for an aneurysmal rupture etiology but later confirmed to be a pituitary apoplexy from a large pituitary adenoma. Intraventricular hemorrhage due to a pituitary apoplexy could be mistaken for an aneurysmal origin thus warranting for a careful evaluation of the sellar region.

  8. Conduction disorders using the Evolut R prosthesis compared with the CoreValve: has anything changed?

    Science.gov (United States)

    Perrin, Nils; Perrin, Tilman; Hachulla, Anne-Lise; Frei, Angela; Müller, Hajo; Roffi, Marco; Cikirikcioglu, Mustafa; Ellenberger, Christoph; Licker, Marc-Joseph; Burri, Haran; Noble, Stephane

    2018-01-01

    We compared early postprocedural and midterm evolution of atrioventricular and intraventricular conduction disorders following implantation of the new generation Evolut R (ER) prosthesis in comparison with the previous generation CoreValve (CV) system using routinely recorded ECG up to 6-month follow-up. All consecutive patients treated by transcathether aortic valve implantation (TAVI) using the Medtronic self-expanding devices for symptomatic severe aortic stenosis in a single centre between October 2011 and February 2016 were considered for inclusion. ECGs recorded at baseline, day 1 after TAVI, discharge and 6 months were retrospectively analysed. At each time-point, intrinsic rhythm, PR interval, QRS axis and duration, and atrioventricular and intraventricular conduction were analysed. Atrioventricular and intraventricular conduction following TAVI at discharge and at 6 months were compared intrasubject at the different time intervals and between patients receiving the ER versus the CV prosthesis. Among the 113 patients included in the analysis (51% female, 83.3±6.2 years), 60 (53%) patients received the CV and 53 (47%) patients received the ER. Compared with patients in the CV group, those in the ER group had a lower Society of Thoracic Surgeons score (6.3±3.1vs 4.8±3.6, P=0.02). Patients in the ER group in comparison with those in the CV group more frequently had postprocedural PR interval (57%vs23%, respectively, P=0.004) and QRS prolongation (76%vs50%, P=0.03) at discharge. Incidence of complete atrioventricular block was similar between both groups (9%vs18%, P=0.3) up to 6-month follow-up. No difference in term of new left bundle branch block (LBBB) (34%vs28%, P=0.8) or permanent pacemaker implantation rates (32.1%vs31.7%, P=1.0) was reported. Patients with the ER had greater postprocedural atrioventricular and intraventricular conduction delays than those with the CV at discharge, with however similar incidence of high-degree atrioventricular block

  9. MRI demonstration of unsuspected intraventricular rupture of pyogenic cerebral abscesses in patients being treated for meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Kamra, P.; Venkatesh, S.K.; Gupta, R.K. [Department of Radiodiagnosis, Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Uttar Pradesh (India); Vatsal, D.K.; Husain, M. [Department of Neurosurgery, KG Medical College, Lucknow (India); Pradhan, S. [Department of Neurology, Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Uttar Pradesh (India)

    2002-02-01

    We report three patients with pyogenic meningitis who showed a partial response to medical treatment. MRI demonstrated an unsuspected brain abscess with intraventricular rupture, a possible cause of the partial response to treatment. (orig.)

  10. The role of 3D volumetric MR sequences in diagnosing intraventricular neurocysticercosis: preliminar results

    Directory of Open Access Journals (Sweden)

    Francisco Edward Frota Mont'Alverne Filho

    2011-02-01

    Full Text Available OBJECTIVE: The purpose of this paper was to investigate the role of two three-dimensional magnetic resonance (MRI sequences: enhanced spoiled gradient recalled echo (SPGR, and fast imaging employing steady-state acquisition (FIESTA in the evaluation of intraventricular neurocysticercosis cysts and scolices. METHOD: Seven neurocysticercosis patients suspected of presenting intraventricular lesions were evaluated by magnetic resonance imaging using enhanced SPGR, and FIESTA. RESULTS: Enhanced SPGR detected eight cystic lesions, with scolices in four. Contrast enhancement was observed in three cysts. FIESTA also detected eight cystic lesions with the presence of scolices in seven of those cystic lesions. Four patients presented parenchymal involvement, while the remaining three presented the racemose form. CONCLUSION: FIESTA and SPGR are sequences that can detect intraventricular cysts of neurocysticercosis, and FIESTA also is good for the detection of the scolex. Considering this information we suggest that FIESTA and SPGR should be included in the MRI protocol for the investigation of intraventricular neurocysticercosis.

  11. Temporal Lobe Encephalocele in the Lateral Recess of the Sphenoid Sinus Presenting with Intraventricular Tension Pneumocephalus

    OpenAIRE

    Ohkawa, Toshika; Nakao, Naoyuki; Uematsu, Yuji; Itakura, Toru

    2010-01-01

    A basal encephalocele often shows an insidious clinical course. Only two cases of temporal lobe encephalocele accompanied with tension pneumocephalus have previously been reported. In this paper, we describe a case of lateral sphenoid sinus encephalocele presenting with intraventricular tension pneumocephalus. A 54-year-old man was referred to our institution presenting with intraventricular tension pneumocephalus. He had undergone ventriculoperitoneal shunt placement for postmeningitis hydro...

  12. [Chronology of ultrasonographic course of neonatal intraventricular hemorrhage stage III].

    Science.gov (United States)

    Monset-Couchard, M; Szwalkiewicz-Warowicka, E; de Bethmann, O

    1993-01-01

    During the 1981-90 decade, 31 unilateral grade III intraventricular hemorrhages (III IVH), with controlateral grade I or grade II, and 65 bilateral grade III IVH were detected by brain ultrasound studies in the neonatal intensive care unit of Port-Royal. Varied hemorrhages were present on day 1 in 66% of unilateral III IVH and 72% of bilateral III IVH, and in all cases by day 4. Bilateral grade III was reached only between days 4 and 8 in 32% of cases. Death rate was 35% in unilateral III IVH and 66% in bilateral III IVH. Median dates of observation were: days 2-3, clots in the third ventricle and cisterna magna; days 29-35, disappearance of clots in lateral ventricles; days 2-4, onset of ventricular dilatation; days 15-20, maximal dilatation; days 22-27, onset of regressive dilatation; day 54-3 months, maximal regression of dilatation. The total number of true hydrocephalus was 3/31 in unilateral III IVH and 12/65 in bilateral III IVH. The 20 survivors after unilateral III IVH had 17 regressive dilatations (10 spontaneous and 7 with acetazolamide), 1 hydrocephalus treated by ventriculo-peritoneal shunt (VPS), 2 regressions with late hydrocephalus (2 VPS). The 21 survivors after bilateral III IVH had 19 regressive dilatations (6 spontaneous and 13 with acetazolamide), and 2 hydrocephalus (2 VPS). A late limited dilatation reappeared between 3 and 9 months of age in infants with neonatal periventricular leukomalacias.

  13. A study of acute expired cases with intraventricular hemorrhage

    International Nuclear Information System (INIS)

    Ikeda, Yukio; Higuchi, Hiroshi; Ueda, Kenji; Kobayashi, Shiro; Yajima, Kouzo

    1981-01-01

    Prior to the introduction of the CT scan, the diagnosis of intraventricular hemorrhage (IVH) was very difficult. The CT scan has, though, been recognized to be extremely informative in the evaluation of IVH. During the first three years we have had experience with 91 cases of IVH diagnosed by the CT scan. Acute death within seven days occurred in 42 of these cases. Hypertension was the most common Acute death within seven days occurred in 42 of these cases. Hypertension was the most common etiological factor, accounting for 18 cases. Cerebral aneurysm was the second most common cause, accounting for 10 cases. Head injury was seen in 8 cases, while the causes of 4 deaths were unknown. 31 cases were distributed over all ventricles. 30 cases revealed over two cast formations. The presence of IVH in the third and/or the fourth ventricle, which can easily affect the function of the hypothalamus and the brain stem anatomically, was closely correlated with the high mortality rate. The analysis of the CT findings regarding the mechanisms of IVH reveals three types: the direct type, which bleeds directly into ventricles without forming definite intracerebral hematomas; the extension type, which is characterized by extension and rupture from massive intracerebral hematoma, and the reflux type, which is characterized by a reflux of the subarachnoid blood. The prognosis depends on the differences in these mechanisms. (author)

  14. Peri-intraventricular hemorrhage in newborns weighing less than 1500 grams: comparative analysis between 2 institutions

    Directory of Open Access Journals (Sweden)

    Ponte Marinice Duarte da

    2003-01-01

    Full Text Available PURPOSE: This study aims to characterize the peri-intraventricular hemorrhages in the neonatal period in very low birth weight newborns in 2 institutions that provide neonatal tertiary assistance. METHOD: This was a comparative and observational study in 2 neonatal intensive care units, the Maternity Hospital of Campinas and the "Centro de Atenção Integrada à Saúde da Mulher" of the State University of Campinas, from December 01, 1998 to November 30, 1999. We examined 187 newborns for peri-intraventricular hemorrhages, using transfontanel ultrasound (76 and 11 respectively at the first and second unit, and classified them into 4 grades. We observed their gender, intrauterine growth, weight, and gestational age at birth. RESULTS: We diagnosed 34 cases of peri-intraventricular hemorrhages (13 and 21, respectively, and both groups differed as to the birth weight and the adequacy of weight to the gestational age at birth. There was no difference in the prevalence or extent of peri-intraventricular hemorrhages among cases. There was a statistically significant occurrence of lower birth weight at gestational ages of less than 30 weeks. CONCLUSIONS: The prevalence of peri-intraventricular hemorrhages in our study was compared to that reported in the world literature. Although the cases of the second institution had a smaller mean birth weight, the prevalence of peri-intraventricular hemorrhages was similar to that at the first institution, probably because in the first one, 69% of the gestational ages of the neonates with hemorrhage were less than 30 weeks as compared to 48% in the second one. We stress the importance of the ultrasonographic method for diagnosing peri-intraventricular hemorrhages in very low birth weight newborns.

  15. A modified echocardiographic protocol with intrinsic plausibility control to determine intraventricular asynchrony based on TDI and TSI.

    Science.gov (United States)

    Dreger, Henryk; Borges, Adrian C; Ismer, Bruno; Schattke, Sebastian; Stegemann, Berthold; Baumann, Gert; Melzer, Christoph

    2009-09-25

    Established methods to determine asynchrony suffer from high intra- and interobserver variability and failed to improve patient selection for cardiac resynchronization therapy (CRT). Thus, there is a need for easy and robust approaches to reliably assess cardiac asynchrony. We performed echocardiography in 100 healthy subjects and 33 patients with left bundle branch block (LBBB). To detect intraventricular asynchrony, we combined two established methods, i.e., tissue synchronization imaging (TSI) and tissue Doppler imaging (TDI). The time intervals from the onset of aortic valve opening (AVO) to the peak systolic velocity (S') were measured separately in six basal segments in the apical four-, two-, and three-chamber view. Color-coded TSI served as an intrinsic plausibility control and helped to identify the correct S' measuring point in the TDI curves. Next, we identified the segment with the shortest AVO-S' interval. Since this segment most likely represents vital and intact myocardium it served as a reference for other segments. Segments were considered asynchronous when the delay between the segment in question and the reference segment was above the upper limit of normal delays derived from the control population. Intra- and interobserver variability were 7.0% and 7.7%, respectively. Our results suggest that combination of TDI and TSI with intrinsic plausibility control improves intra- and interobserver variability and allows easy and reliable assessment of cardiac asynchrony.

  16. Incidence of Intraventricular Hemorrhage and Post Hemorrhagic Hydrocephalus in Preterm Infants

    Directory of Open Access Journals (Sweden)

    Negar Sajjadian

    2010-07-01

    Full Text Available "nGerminal matrix-intraventricular hemorrhage (IVH is the most common variety of neonatal intracranial hemorrhage and is characteristics of the premature infant. The importance of the lesion relates not only to its high incidence but to their attendant complications (IC: hydrocephalus. Brain sonography is the procedure of choice in diagnosis of germinal matrix- intraventricular hemorrhage and hydrocephalus. In this study we have used brain sonography for detection of intraventricular hemorrhage and post hemorrhagic hydrocephalus and their incidences. The studied population was consisted of premature neonate (birth weight equal or less than 1500g and gestational age equal or less than 37 weeks who admitted in Mofid Hospital NICU (Tehran, Iran during a one year period. For all neonate (including criteria brain sonography in first week of life was done and in presence of IVH, serial Brain sonography was done weekly for detection of hydrocephalus. A total of 57 neonate entered the study. Intraventicular-germinal matrix hemorrhage was seen in 64.4% (35 patients. Forty percent of patients with intraventricular-germinal matrix hemorrhage had grade I, 11% grade II, 25.7% grade III, 2.8% grade VI. Hydrocephalus was detected in 20 percent of patients who had intraventricular-germinal matrix hemorrhage. That incidence of IVH in our study in comparison with other area and situation is higher. Hydrocephaly had direct relation with severity of IVH. This shows that with control of risk factor of IVH, we can control Post hemorrhagic hydrocephalus.

  17. Results of Combined Intraventricular Neuroendoscopic Procedures in 130 Cases with Special Focus on Fornix Contusions.

    Science.gov (United States)

    Oertel, Joachim; Linsler, Stefan; Emmerich, Caroline; Keiner, Dörthe; Gaab, Michael; Schroeder, Henry; Senger, Sebastian

    2017-12-01

    Increasing experience with intraventricular neuroendoscopic procedures shows good results in the combination of endoscopic third ventriculostomy (ETV) and tumor biopsy. Other possible combinations are mainly presented in subgroups in the literature. Here, we present our experience with combined intraventricular procedures within 1 setting over the last 2 decades. This study retrospectively analyzes data from neuroendoscopic intraventricular procedures between 1993 and 2015 in 3 different departments of neurosurgery. Inclusion criteria were a combination of at least 2 intraventricular endoscopic procedures (e.g. third ventriculostomy, cyst fenestration, tumor surgery or aqueductoplasty) within 1 setting. One-hundred and thirty cases with more than 300 procedures fulfilled the inclusion criteria. The most frequent combinations were ETV and tumor biopsy (n = 36), ETV and aqueductoplasty/stenting (n = 30), and ETV and cyst fenestration (n = 18). The complication rate was 16.9% with an overall morbidity of 1.6% and mortality of 0.8%. Fornix contusion was one of the most frequent intraoperative complications (16.4%). Shunt independency was achieved in 82.9% of cases with hydrocephalic symptoms. A combination of different intraventricular endoscopic procedures is safe and reliable, bearing similar risks of morbidities and mortality to single neuroendoscopic procedures. This study is one of the largest series in the literature and has similar low complication rates to others. Fornix contusion is the most frequent intraoperative complication in these patients. However, obvious clinical correlation is rare. Copyright © 2017. Published by Elsevier Inc.

  18. Early neurodevelopment in very low birth weight infants with mild intraventricular hemorrhage or those without intraventricular hemorrhage

    Directory of Open Access Journals (Sweden)

    Il Rak Choi

    2012-11-01

    Full Text Available &lt;B&gt;Purpose:&lt;/B&gt; This study aimed to assess early development in very low birth weight (VLBW infants with mild intraventricular hemorrhage (IVH or those without IVH and to identify the perinatal morbidities affecting early neurodevelopmental outcome. &lt;B&gt;Methods:&lt;/B&gt; Bayley Scales of Infant Development-II was used for assessing neurological development in 49 infants with a birth weight &lt;1,500 g and with low grade IVH (?#167;rade II or those without IVH at a corrected age of 12 months. &lt;B&gt;Results:&lt;/B&gt; Among the 49 infants, 19 infants (38.8% showed normal development and 14 (28.6% showed abnormal mental and psychomotor development. Infants with abnormal mental development (n=14 were mostly male and had a longer hospitalization, a higher prevalence of patent ductus arteriosus (PDA and bronchopulmonary dysplasia (BPD, and were under more frequent postnatal systemic steroid treatment compared with infants with normal mental development (n=35, P&lt;0.05. Infants with abnormal psychomotor development (n=29 had a longer hospitalization and more associated PDA compared to infants with normal psychomotor development (n=20, P&lt;0.05. Infants with abnormal mental and psychomotor development were mostly male and had a longer hospitalization and a higher prevalence of PDA and BPD compared to infants with normal mental and psychomotor development (n=19, P&lt;0.05. Using multiple logistic regression analysis, a longer duration of hospitalization and male gender were found to be significant risk factors. &lt;B&gt;Conclusion:&lt;/B&gt; Approximately 62% of VLBW infants with low grade IVH or those without IVH had impaired early development.

  19. Intraventricular catheter placement by electromagnetic navigation safely applied in a paediatric major head injury patient.

    Science.gov (United States)

    Aufdenblatten, Christoph Alexander; Altermatt, Stefan

    2008-09-01

    In the management of severe head injuries, the use of intraventricular catheters for intracranial pressure (ICP) monitoring and the option of cerebrospinal fluid drainage is gold standard. In children and adolescents, the insertion of a cannula in a compressed ventricle in case of elevated intracranial pressure is difficult; therefore, a pressure sensor is placed more often intraparenchymal as an alternative option. In cases of persistent elevated ICP despite maximal brain pressure management, the use of an intraventricular monitoring device with the possibility of cerebrospinal fluid drainage is favourable. We present the method of intracranial catheter placement by means of an electromagnetic navigation technique.

  20. Energy dynamics of the intraventricular vortex after mitral valve surgery.

    Science.gov (United States)

    Nakashima, Kouki; Itatani, Keiichi; Kitamura, Tadashi; Oka, Norihiko; Horai, Tetsuya; Miyazaki, Shohei; Nie, Masaki; Miyaji, Kagami

    2017-09-01

    Mitral valve morphology after mitral valve surgery affects postoperative intraventricular flow patterns and long-term cardiac performance. We visualized ventricular flow by echocardiography vector flow mapping (VFM) to reveal the impact of different mitral valve procedures. Eleven cases of mechanical mitral valve replacement (nine in the anti-anatomical and two in the anatomical position), three bioprosthetic mitral valve replacements, and four mitral valve repairs were evaluated. The mean age at the procedure was 57.4 ± 17.8 year, and the echocardiography VFM in the apical long-axis view was performed 119.9 ± 126.7 months later. Flow energy loss (EL), kinetic pressure (KP), and the flow energy efficiency ratio (EL/KP) were measured. The cases with MVR in the anatomical position and with valve repair had normal vortex directionality ("Clockwise"; N = 6), whereas those with MVR in the anti-anatomical position and with a bioprosthetic mitral valve had the vortex in the opposite direction ("Counterclockwise"; N = 12). During diastole, vortex direction had no effect on EL ("Clockwise": 0.080 ± 0.025 W/m; "Counterclockwise": 0.083 ± 0.048 W/m; P = 0.31) or KP ("Clockwise": 0.117 ± 0.021 N; "Counterclockwise": 0.099 ± 0.057 N; P = 0.023). However, during systole, the EL/KP ratio was significantly higher in the "Counterclockwise" vortex than that in the "Clockwise" vortex (1.056 ± 0.463 vs. 0.617 ± 0.158; P = 0.009). MVP and MVR with a mechanical valve in the anatomical position preserve the physiological vortex, whereas MVR with a mechanical valve in the anti-anatomical position and a bioprosthetic mitral valve generate inefficient vortex flow patterns, resulting in a potential increase in excessive cardiac workload.

  1. Intraventricular Insulin Reduces Food Intake and Body Weight of Marmots During the Summer Feeding Period

    NARCIS (Netherlands)

    Florant, G.L.; Singer, L.; Scheurink, A.J.W.; Park, C.R.; Richardson, R.D.; Woods, S.C.

    1991-01-01

    The study presented below describes experiments that investigate the ability of insulin to inhibit food intake in awake, active marmots during the summer season. Our results suggest that increasing intraventricular insulin concentration during the summer active feeding period will cause a decrease

  2. Parenchymal neurocutaneous melanosis in association with intraventricular dermoid and Dandy-walker variant: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Joo; Won, Yoo Dong; Kim, Ki Tae; Chang, Eun Deok; Huh, Pil Woo [The Catholic University of Korea, College of Medicine, Uijongbu (Korea, Republic of)

    2006-06-15

    Neurocutaneous melanosis (NCM) is a rare congenital disease that is characterized by the presence of large or multiple congenital melanocytic nevi and melanotic lesions of the central nervous system. We report here on the CT and MR imaging findings of an unusual case of NCM that was associated with intraventricular dermoid and Dandy-Walker malformation.

  3. Hypertensive peaks in the pathogenesis of intraventricular hemorrhage in the newborn. Abolition by phenobarbitone sedation

    DEFF Research Database (Denmark)

    Wimberley, P D; Lou, H C; Pedersen, H

    1982-01-01

    Mean arterial blood pressure (MABP) was measured continuously for 3 to 5 days after birth in 27 premature infants with a birth weight under 1500 g, and who required umbilical artery catheterisation. All had respiratory distress syndrome (RDS). Intraventricular hemorrhage (IVH) occurred in 9 infants...

  4. A case of pineal teratoma with intraventricular free fat on CT scan

    International Nuclear Information System (INIS)

    Uede, Teiji; Takaya, Satoru; Shinya, Toshiyuki; Tanabe, Sumiyoshi; Hashi, Kazuo; Sohma, Tsutomu.

    1986-01-01

    Detection of an intraventricular or intratumoral fat-fluid level on the plain craniograms has been known as a characteristic sign indicating the presence of intracranial teratomatous tumors. On CT scans, however, only thirteen cases have been previously reported to be found an intraventricular and/or subarachnoid free fat associated with spontaneous ruptures of these tumors. We reported a case of pineal teratoma with intraventricular free-fat seen on CT scans. A nine-year-old male with precocious puberty was admitted to our hospital complaining a moderate nonpulsatile headache. Neurological examinations were normal without signs of meningeal irritation. The serum and CSF titer of HCG were raised markedly. The laboratory data of the CSF were normal and there were no pathological cells in the CSF. The CT scans revealed a large heterogeneous mass containing multiple areas of negative density in the pineal region. There were negative density droplets in the bilateral frontal horn on the same CT scans indicating a presence of free fats. At surgery, an yellowish oily material was drained from the tumor, but there was no sign of meningitis over the cortical surface of the occipital lobe. An intraventricular free fat on CT scan have been reported in fourteen cases including ours following the first case described by Fawcitt in 1976. Although most of the cases presented headache, only two cases was diagnosed clinically as chemical meningitis. Pathological changes indicating granulomatous meningitis, however, were noted in five cases, all of them presenting seizure attacks. (author)

  5. Computational Analysis of Intra-Ventricular Flow Pattern Under Partial and Full Support of BJUT-II VAD.

    Science.gov (United States)

    Zhang, Qi; Gao, Bin; Chang, Yu

    2017-02-27

    BACKGROUND Partial support, as a novel support mode, has been widely applied in clinical practice and widely studied. However, the precise mechanism of partial support of LVAD in the intra-ventricular flow pattern is unclear. MATERIAL AND METHODS In this study, a patient-specific left ventricular geometric model was reconstructed based on CT data. The intra-ventricular flow pattern under 3 simulated conditions - "heart failure", "partial support", and "full support" - were simulated by using fluid-structure interaction (FSI). The blood flow pattern, wall shear stress (WSS), time-average wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT) were calculated to evaluate the hemodynamic effects. RESULTS The results demonstrate that the intra-ventricular flow pattern is significantly changed by the support level of BJUT-II VAD. The intra-ventricular vortex was enhanced under partial support and was eliminated under full support, and the high OSI and RRT regions changed from the septum wall to the cardiac apex. CONCLUSIONS In brief, the support level of the BJUT-II VAD has significant effects on the intra-ventricular flow pattern. The partial support mode of BJUT-II VAD can enhance the intra-ventricular vortex, while the distribution of high OSI and RRT moved from the septum wall to the cardiac apex. Hence, the partial support mode of BJUT-II VAD can provide more benefit for intra-ventricular flow pattern.

  6. The Role of ADC-Based Thermometry in Measuring Brain Intraventricular Temperature in Children.

    Science.gov (United States)

    Wagner, Matthias W; Stern, Steven E; Oshmyansky, Alexander; Huisman, Thierry A G M; Poretti, Andrea

    2016-05-01

    To determine the feasibility of apparent diffusion coefficient (ADC)-based thermometry to assess intraventricular temperature in children. ADC maps were generated from diffusion tensor imaging data, which were acquired with diffusion gradients along 20 noncollinear directions using a b-value of 1000 s/mm(2) . The intraventricular temperature was calculated based on intraventricular ADC values and the mode method as previously reported. The calculated intraventricular temperature was validated with an estimated brain temperature based on temporal artery temperature measurements. We included 120 children in this study (49 females, 71 males, mean age 6.63 years), 15 consecutive children for each of the following age groups: 0-1, 1-2, 2-4, 4-6, 6-8, 8-10, 10-14, and 14-18 years. Forty-three children had a normal brain MRI and 77 children had an abnormal brain scan. Polynomial fitting to the temperature distribution and subsequent calculation of mode values was performed. A correlation coefficient and a coefficient of determination were calculated between ADC calculated temperatures and estimated brain temperatures. Linear regression analysis was performed to investigate the two temperature measures. ADC-based intraventricular temperatures ranged between 31.5 and 39.6 °C, although estimated brain temperatures ranged between 36.3 and 38.1 °C. The difference between the temperatures is larger for children with more than 8,000 voxels within the lateral ventricles compared to children with less than 8,000 voxels. The correlation coefficient between ADC-based temperatures and the estimated brain temperatures is .1, the respective R(2) is .01 indicating that 1% of the changes in estimated brain temperatures are attributable to corresponding changes in ADC-based temperature measurements (P = .275). ADC-based thermometry has limited application in the pediatric population mainly due to a small ventricular size. Copyright © 2015 by the American Society of Neuroimaging.

  7. Intraventricular neurocysticercosis. Presentation of a case located in the third ventricle; Neurocisticercosis intraventricular. Presentacion de un caso localizado en el tercer ventriculo

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, L.; Abad, L.; Lozano, E.; Maldonado, G. [Complejo Hospitalario Universitario de Albacete (Spain)

    2002-07-01

    Neurocysticercosis is the most common cerebral parasitosis. Of the three forms in which it can present itself, intraventricular cysticercosis is the least common and has the poorest prognosis. Diagnosis is principally made through the use of neuroimaging methods, especially MR, which is also indispensable both as a preoperative control and in the choice and response evaluation of postoperative treatment. We present the case of a 24-year-old Ecuadoran woman with clinical intracraneal hypertension due to a cysticercus cyst in the third ventricle. We analyze the imaging findings and their usefulness in assessing possible treatments. (Author) 13 refs.

  8. Intraventricular Hemorrhage Due to Coagulopathy After Vitamin K Administration in a Preterm Infant With Maternal Crohn Disease

    OpenAIRE

    Kazumichi Fujioka; Sachiyo Fukushima; Kosuke Nishida; Kazumoto Iijima; Ichiro Morioka

    2017-01-01

    Intraventricular hemorrhage (IVH) is a devastating morbidity in preterm infants and can result in poor neurodevelopmental outcomes. Intraventricular hemorrhage usually occurs within 72 hours after birth; post–acute-phase IVH (>1 week after birth) is uncommon. Development of the hemostatic system in fetuses and neonates is an age-dependent evolving process, and the neonatal hemostatic system is characterized by low levels of vitamin K–dependent factors, with further reduction caused by prematu...

  9. Intraventricular Hemorrhage Due to Coagulopathy After Vitamin K Administration in a Preterm Infant With Maternal Crohn Disease

    OpenAIRE

    Fujioka, Kazumichi; Fukushima, Sachiyo; Nishida, Kosuke; Iijima, Kazumoto; Morioka, Ichiro

    2017-01-01

    Intraventricular hemorrhage (IVH) is a devastating morbidity in preterm infants and can result in poor neurodevelopmental outcomes. Intraventricular hemorrhage usually occurs within 72 hours after birth; post-acute-phase IVH (> 1 week after birth) is uncommon. Development of the hemostatic system in fetuses and neonates is an age-dependent evolving process, and the neonatal hemostatic system is characterized by low levels of vitamin K-dependent factors, with further reduction caused by premat...

  10. Intraventricular mass lesions at magnetic resonance imaging: iconographic essay - part 2

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Felipe Damasio de; Reis, Fabiano; Guerra, Jose Guilherme Giocondo, E-mail: fdamasiocastro@gmail.com [Universidade Estadual de Campinas (Unicamp), Campinas, SP (Brazil)

    2014-07-15

    The present essay is illustrated with magnetic resonance images obtained at the authors’ institution over the past 15 years and discusses the main imaging findings of intraventricular tumor-like lesions (colloid cyst, oligodendroglioma, astroblastoma, lipoma, cavernoma) and of inflammatory/infectious lesions (neurocysticercosis and an atypical presentation of neurohistoplasmosis). Such lesions represent a subgroup of intracranial lesions with unique characteristics and some imaging patterns that may facilitate the differential diagnosis. (author)

  11. Therapeutic drug monitoring of cerebrospinal fluid vancomycin concentration during intraventricular administration.

    Science.gov (United States)

    Popa, D; Loewenstein, L; Lam, S W; Neuner, E A; Ahrens, C L; Bhimraj, A

    2016-02-01

    Limited data are available on intraventricular vancomycin dosing for meningitis. This study explored clinical characteristics that correlated with cerebrospinal fluid (CSF) concentrations. Over a nine-year period, 13 patients with 34 CSF vancomycin concentrations were evaluated. CSF output and time from dose correlated with CSF vancomycin concentration. No relationship was seen with regards to CSF protein, white blood cell count or glucose. Copyright © 2015. Published by Elsevier Ltd.

  12. In situ cardiac perfusion reveals interspecific variation of intraventricular flow separation in reptiles.

    Science.gov (United States)

    Joyce, William; Axelsson, Michael; Altimiras, Jordi; Wang, Tobias

    2016-07-15

    The ventricles of non-crocodilian reptiles are incompletely divided and provide an opportunity for mixing of oxygen-poor blood and oxygen-rich blood (intracardiac shunting). However, both cardiac morphology and in vivo shunting patterns exhibit considerable interspecific variation within reptiles. In the present study, we develop an in situ double-perfused heart approach to characterise the propensity and capacity for shunting in five reptile species: the turtle Trachemys scripta, the rock python Python sebae, the yellow anaconda Eunectes notaeus, the varanid lizard Varanus exanthematicus and the bearded dragon Pogona vitticeps To simulate changes in vascular bed resistance, pulmonary and systemic afterloads were independently manipulated and changes in blood flow distribution amongst the central outflow tracts were monitored. As previously demonstrated in Burmese pythons, rock pythons and varanid lizards exhibited pronounced intraventricular flow separation. As pulmonary or systemic afterload was raised, flow in the respective circulation decreased. However, flow in the other circulation, where afterload was constant, remained stable. This correlates with the convergent evolution of intraventricular pressure separation and the large intraventricular muscular ridge, which compartmentalises the ventricle, in these species. Conversely, in the three other species, the pulmonary and systemic flows were strongly mutually dependent, such that the decrease in pulmonary flow in response to elevated pulmonary afterload resulted in redistribution of perfusate to the systemic circuit (and vice versa). Thus, in these species, the muscular ridge appeared labile and blood could readily transverse the intraventricular cava. We conclude that relatively minor structural differences between non-crocodilian reptiles result in the fundamental changes in cardiac function. Further, our study emphasises that functionally similar intracardiac flow separation evolved independently in

  13. Neonatal cerebral oxygenation is not linked to foetal vasculitis and predicts intraventricular haemorrhage in preterm infants

    DEFF Research Database (Denmark)

    Sørensen, Line Carøe; Maroun, Lisa Leth; Borch, K.

    2008-01-01

    AIM: The aim of the study was to compare the cerebral tissue oxygenation index (c-TOI) measured by near infrared spectroscopy (NIRS) in infants with and without foetal vasculitis. METHODS: Twenty-four infants with placental signs of a foetal inflammatory response (FIR), foetal vasculitis, were.......002). CONCLUSION: Cerebral oxygenation was not affected in the first day of life in preterm infants born with foetal vasculitis, while cerebral oxygenation in infants that later developed intraventricular haemorrhage was impaired Udgivelsesdato: 2008/11...

  14. Neonatal cerebral oxygenation is not linked to foetal vasculitis and predicts intraventricular haemorrhage in preterm infants

    DEFF Research Database (Denmark)

    Sorensen, Line C; Maroun, Lisa L; Borch, Klaus

    2008-01-01

    Aim: The aim of the study was to compare the cerebral tissue oxygenation index (c-TOI) measured by near infrared spectroscopy (NIRS) in infants with and without foetal vasculitis. Methods: Twenty-four infants with placental signs of a foetal inflammatory response (FIR), foetal vasculitis, were.......002). Conclusion: Cerebral oxygenation was not affected in the first day of life in preterm infants born with foetal vasculitis, while cerebral oxygenation in infants that later developed intraventricular haemorrhage was impaired....

  15. Periventricular nodular heterotopia and bilateral intraventricular xanthogranulomas in 22q11.2 deletion syndrome

    Directory of Open Access Journals (Sweden)

    Moogeh Baharnoori

    2017-09-01

    Full Text Available 22q11.2 deletion syndrome (22q11DS is the most common pathogenic copy number variant in humans. Neuropsychiatric phenotypes, including schizophrenia, are prominent. Imaging studies of individuals with this syndrome show a variety of abnormalities that may indicate abnormal neuronal migration. Here we present the neuroimaging and neuropathologic features of a 22q11DS patient with bilateral periventricular nodular heterotopias (PNH and intraventricular xanthogranulomas that were identified by post-mortem examination.

  16. Usefulness of intraventricular infusion of antifungal drugs through Ommaya reservoirs for cryptococcal meningitis treatment.

    Science.gov (United States)

    Nakama, Tatsuya; Yamashita, Satoshi; Hirahara, Tomoo; Okamoto, Sadahisa; Honda, Shoji; Watanabe, Masaki; Kimura, En; Uchino, Makoto; Yano, Shigetoshi; Kuratsu, Jun-ichi; Ando, Yukio

    2015-11-15

    Cryptococcal meningitis is a severe infection among immunosuppressed individuals, with a high mortality rate. Although amphotericin B is the first-choice drug for treatment, its use is restricted when adverse effects are clinically problematic. The usefulness of intraventricular infusion of antifungal drugs through Ommaya reservoirs for cryptococcal meningitis treatment has been unconfirmed. We evaluated the efficacy of intraventricular infusion of amphotericin B through Ommaya reservoirs. We retrospectively analyzed 10 consecutive patients with cryptococcal meningitis who were refractory to systemic administration of antifungal drugs. Fever or nausea occurred in most patients. However, no patient complained of serious complications such as renal toxicity. Seven patients recovered completely or partially, whereas three patients died. To establish the efficacy of the intraventricular infusion of antifungal drugs through Ommaya reservoirs for cryptococcal meningitis, a prospective investigation should be designed to compare those treated according to the updated guidelines and those treated with antifungal drugs through the Ommaya reservoirs. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Two-dimensional intraventricular flow pattern visualization using the image-based computational fluid dynamics.

    Science.gov (United States)

    Doost, Siamak N; Zhong, Liang; Su, Boyang; Morsi, Yosry S

    2017-04-01

    The image-based computational fluid dynamics (IB-CFD) technique, as the combination of medical images and the CFD method, is utilized in this research to analyze the left ventricle (LV) hemodynamics. The research primarily aims to propose a semi-automated technique utilizing some freely available and commercial software packages in order to simulate the LV hemodynamics using the IB-CFD technique. In this research, moreover, two different physiological time-resolved 2D models of a patient-specific LV with two different types of aortic and mitral valves, including the orifice-type valves and integrated with rigid leaflets, are adopted to visualize the process of developing intraventricular vortex formation and propagation. The blood flow pattern over the whole cardiac cycle of two models is also compared to investigate the effect of utilizing different valve types in the process of the intraventricular vortex formation. Numerical findings indicate that the model with integrated valves can predict more complex intraventricular flow that can match better the physiological flow pattern in comparison to the orifice-type model.

  18. Numerical Modeling of Intraventricular Flow during Diastole after Implantation of BMHV.

    Directory of Open Access Journals (Sweden)

    Boyang Su

    Full Text Available This work presents a numerical simulation of intraventricular flow after the implantation of a bileaflet mechanical heart valve at the mitral position. The left ventricle was simplified conceptually as a truncated prolate spheroid and its motion was prescribed based on that of a healthy subject. The rigid leaflet rotation was driven by the transmitral flow and hence the leaflet dynamics were solved using fluid-structure interaction approach. The simulation results showed that the bileaflet mechanical heart valve at the mitral position behaved similarly to that at the aortic position. Sudden area expansion near the aortic root initiated a clockwise anterior vortex, and the continuous injection of flow through the orifice resulted in further growth of the anterior vortex during diastole, which dominated the intraventricular flow. This flow feature is beneficial to preserving the flow momentum and redirecting the blood flow towards the aortic valve. To the best of our knowledge, this is the first attempt to numerically model intraventricular flow with the mechanical heart valve incorporated at the mitral position using a fluid-structure interaction approach. This study facilitates future patient-specific studies.

  19. Refractory High Intracranial Pressure following Intraventricular Hemorrhage due to Moyamoya Disease in a Pregnant Caucasian Woman

    Directory of Open Access Journals (Sweden)

    Virginie Montiel

    2009-02-01

    Full Text Available Intraventricular hemorrhage during pregnancy is usually followed by a poor recovery. When caused by moyamoya disease, ischemic or hemorrhagic episodes may complicate the management of high intracranial pressure. A 26-year-old Caucasian woman presented with generalized seizures and a Glasgow Coma Score (GCS of 3 during the 36th week of pregnancy. The fetus was delivered by caesarean section. The brain CT in the mother revealed bilateral intraventricular hemorrhage, a callosal hematoma, hydrocephalus and right frontal ischemia. Refractory high intracranial pressure developed and required bilateral ventricular drainage and intensive care treatment with barbiturates and hypothermia. Magnetic resonance imaging and cerebral angiography revealed a moyamoya syndrome with rupture of the abnormal collateral vascular network as the cause of the hemorrhage. Intracranial pressure could only be controlled after the surgical removal of the clots after a large opening of the right ventricle. Despite an initially low GCS, this patient made a good functional recovery at one year follow-up. Management of refractory high intracranial pressure following moyamoya related intraventricular bleeding should require optimal removal of ventricular clots and appropriate control of cerebral hemodynamics to avoid ischemic or hemorrhagic complications.

  20. In vivo proton magnetic resonance spectroscopy of intraventricular tumours of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Majos, Carles; Aguilera, Carles [Hospital Universitari de Bellvitge, Institut de Diagnostic per la Imatge (IDI). Centre Bellvitge, L' Hospitalet de Llobregat, Barcelona (Spain); Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain); Cos, Monica; Camins, Angels; Samitier, Alex; Castaner, Sara; Sanchez, Juan J. [Hospital Universitari de Bellvitge, Institut de Diagnostic per la Imatge (IDI). Centre Bellvitge, L' Hospitalet de Llobregat, Barcelona (Spain); Candiota, Ana P.; Delgado-Goni, Teresa [Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain); Unitat de Bioquimica de Biociencies, Department de Bioquimica i Biologia Molecular, Cerdanyola del Valles (Spain); Mato, David [Hospital Universitari de Bellvitge, Department of Neurosurgery, L' Hospitalet de Llobregat, Barcelona (Spain); Acebes, Juan J. [Hospital Universitari de Bellvitge, Department of Neurosurgery, L' Hospitalet de Llobregat, Barcelona (Spain); Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain); Arus, Carles [Unitat de Bioquimica de Biociencies, Department de Bioquimica i Biologia Molecular, Cerdanyola del Valles (Spain); Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain)

    2009-08-15

    The aim of this study was to assess the usefulness of proton MR spectroscopy in the diagnosis of intraventricular tumours. Fifty-two intraventricular tumours pertaining to 16 different tumour types were derived from our database. All cases had single-voxel proton MR spectroscopy performed at TE at both 30 and 136 ms at 1.5 T. The Mann-Whitney U test was used to search for the most discriminative datapoints each tumour type. Characteristic trends were found for some groups: high Glx and Ala in meningiomas (p<0.001 and p<0.01, respectively), high mobile lipids in metastasis (p<0.001), high Cho in PNET (p<0.001), high mI+Gly in ependymoma (p<0.001), high NAC (p<0.01) in the absence of the normal brain parenchyma pattern in colloid cysts, and high mI/Gly and Ala in central neurocytoma. Proton MR spectroscopy provides additional metabolic information that could be useful in the diagnosis of intraventricular brain tumors. (orig.)

  1. In vivo proton magnetic resonance spectroscopy of intraventricular tumours of the brain

    International Nuclear Information System (INIS)

    Majos, Carles; Aguilera, Carles; Cos, Monica; Camins, Angels; Samitier, Alex; Castaner, Sara; Sanchez, Juan J.; Candiota, Ana P.; Delgado-Goni, Teresa; Mato, David; Acebes, Juan J.; Arus, Carles

    2009-01-01

    The aim of this study was to assess the usefulness of proton MR spectroscopy in the diagnosis of intraventricular tumours. Fifty-two intraventricular tumours pertaining to 16 different tumour types were derived from our database. All cases had single-voxel proton MR spectroscopy performed at TE at both 30 and 136 ms at 1.5 T. The Mann-Whitney U test was used to search for the most discriminative datapoints each tumour type. Characteristic trends were found for some groups: high Glx and Ala in meningiomas (p<0.001 and p<0.01, respectively), high mobile lipids in metastasis (p<0.001), high Cho in PNET (p<0.001), high mI+Gly in ependymoma (p<0.001), high NAC (p<0.01) in the absence of the normal brain parenchyma pattern in colloid cysts, and high mI/Gly and Ala in central neurocytoma. Proton MR spectroscopy provides additional metabolic information that could be useful in the diagnosis of intraventricular brain tumors. (orig.)

  2. Delayed Puberty

    DEFF Research Database (Denmark)

    Kolby, Nanna; Busch, Alexander Siegfried; Juul, Anders

    2017-01-01

    Delayed puberty can be a source of great concern and anxiety, although it usually is caused by a self-limiting variant of the normal physiological timing named constitutional delay of growth and puberty (CDGP). Delayed puberty can, however, also be the first presentation of a permanent condition ...... mineral density) and psychological (e.g., low self-esteem) and underline the importance of careful clinical assessment of the patients....

  3. A clinical scoring system to predict the development of intraventricular hemorrhage (IVH) in premature infants.

    Science.gov (United States)

    Coskun, Yesim; Isik, Semra; Bayram, Tevfik; Urgun, Kamran; Sakarya, Sibel; Akman, Ipek

    2018-01-01

    OBJECTıVE: The aim of this study is to develop a scoring system for the prediction of intraventricular hemorrhage (IVH) in preterm infants in the first 7 days of life. A prospective, clinical study was conducted in Bahcesehir University, Medical Park Goztepe Hospital Neonatal Intensive Care Unit, with the enrollment of 144 preterm infants with gestational age between 24 and 34 weeks. All preterms were followed up for IVH after birth until the 4th week of life. The demographic characteristics and clinical risk factors were noted. Risk factors were analyzed. The score was established after logistic regression analysis, considering the impact of each variable on the occurrence of IVH within the first 7 days of life. The IVH scores were further applied prospectively to 89 preterm infants as validation cohort. Low gestational age (GA), low Apgar score, and having bleeding diathesis were the most important risk factors for IVH. According to these risk factors, a scoring system was developed for IVH ranged from 0 to 5. According to the risk ratios (RR) obtained from the logistic regression model, low GA (≤ 28 gestational week), presence of bleeding diathesis within 7 days, and low Apgar score increased the risk of IVH (RR = 3.32 for GA ≤ 28 gestational week, RR = 6.7 for presence of bleeding diathesis in 7th day, RR = 3 for having low Apgar score). The score was validated successfully in 89 infants. The area under ROC curve was 0.85 for derivation cohort and 0.807 for validation cohort. The predictive ability of the IVH score for derivation and validation cohort was calculated. The negative predictive values of a score less than 4 were 96.4 and 59.1%. CONCLUSıON: Concerning IVH-related sequelae which continue to be a major public health problem, we have developed a feasible predictive model for evaluating the risk for developing IVH for preterm infants in the first 7 days of life.

  4. A 50% reduction of excitability but not of intercellular coupling affects conduction velocity restitution and activation delay in the mouse heart

    NARCIS (Netherlands)

    Stein, M.; van Veen, T.A.B.; Hauer, R.N.W.; de Bakker, J.M.T.; van Rijen, H.V.M.

    2011-01-01

    Computer simulations suggest that intercellular coupling is more robust than membrane excitability with regard to changes in and safety of conduction. Clinical studies indicate that SCN5A (excitability) and/or Connexin43 (Cx43, intercellular coupling) expression in heart disease is reduced by

  5. Treatment of delayed rupture of the left ventricle after mitral valve replacement

    Directory of Open Access Journals (Sweden)

    Gomes Walter J.

    2002-01-01

    Full Text Available Rupture of the left ventricle following mitral valve replacement is a catastrophic complication with deadly consequences. We report here the case of a 75-year-old man who underwent elective mitral valve replacement for severe mitral regurgitation. Delayed type 1 rupture of the left ventricle developed 3 hours postoperatively in the intensive care unit. A salvaging maneuver was used, which gained time, allowing reoperation and successful intraventricular repair.

  6. Peri-intraventricular hemorrhage and oxidative and inflammatory stress markers in very-low birth weight newborns.

    Science.gov (United States)

    Caldas, Jamil P S; Braghini, Carolina A; Mazzola, Taís N; Vilela, Maria M S; Marba, Sérgio T M

    2015-01-01

    To evaluate the association between oxidative and inflammatory stress markers with peri-intraventricular hemorrhage (PIVH) in very-low birth weight newborns. This was a prospective study conducted in a level III neonatal unit. Basal and stimulated reactive oxygen intermediates (ROIs), reduced glutathione (GSH), and interleukin-6 (IL-6) levels were measured in umbilical cord blood. Newborns underwent serial ultrasound at the bedside, at 6, 12, 24, and 72hours of life and at seven days for the diagnosis of PIVH, classified as grades I to IV. Two groups were assessed, those with and without PIVH; maternal and neonatal control variables were used for comparison. Univariate and multiple regression analyses were applied. A total of 125 newborns were assessed. PIVH incidence rate was 12.0%. In the univariate analysis, basal ROI, the use of two or more doses of corticosteroids, birth weight<1,000g, ventilatory support use, and SNAPPE II value ≥ 22 were significantly associated with PIVH. However, in the multivariate analysis, only antenatal steroid use was independently associated with the disease (OR 0,194; 95% CI: 0,048 to 0,773; p=0,02). ROI, GSH, and IL-6 levels were not associated with the occurrence of PIVH in very-low birth weight infants. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  7. Delayed neurological deterioration due to progressive pneumocephalus

    Directory of Open Access Journals (Sweden)

    Agrawal Amit

    2015-03-01

    Full Text Available Pneumocephalus can develop immediately following head trauma or clinical presentation may be delayed for days. We report a case of 35 year male whose initial CT scan brain plain small specks of pneumocephalus in left para-sellar region. However the next day he was complaining of severe headache and had multiple episodes of vomiting. Repeat CT scan showed increase in the size of pneumocephalus including appearance of intraventricular air with mild cerebral edema. The patient recovered well with conservative management. The present case is a gentle reminder that in a subgroup of head injury patients, intracranial air can produce significant mass effect leading to tension pneumocephalus which can can behave like other intracranial mass lesions and causes worsening of the neurological status of these patients.

  8. Mechanism of Solder Joint Cracks in Anisotropic Conductive Films Bonding and Solutions: Delaying Hot-Bar Lift-Up Time and Adding Silica Fillers

    Directory of Open Access Journals (Sweden)

    Shuye Zhang

    2018-01-01

    Full Text Available Micron sizes solder metallurgical joints have been applied in a thin film application of anisotropic conductive film and benefited three general advantages, such as lower joint resistance, higher power handling capability, and reliability, when compared with pressure based contact of metal conductor balls. Recently, flex-on-board interconnection has become more and more popular for mobile electronic applications. However, crack formation of the solder joint crack was occurred at low temperature curable acrylic polymer resins after bonding processes. In this study, the mechanism of SnBi58 solder joint crack at low temperature curable acrylic adhesive was investigated. In addition, SnBi58 solder joint cracks can be significantly removed by increasing the storage modulus of adhesives instead of coefficient of thermal expansion. The first approach of reducing the amount of polymer rebound can be achieved by using an ultrasonic bonding method to maintain a bonding pressure on the SnBi58 solder joints cooling to room temperature. The second approach is to increase storage modulus of adhesives by adding silica filler into acrylic polymer resins to prevent the solder joint from cracking. Finally, excellent acrylic based SnBi58 solder joints reliability were obtained after 1000 cycles thermal cycling test.

  9. Delayed Ejaculation

    Science.gov (United States)

    ... of stress Delayed ejaculation Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  10. Delayed Ejaculation

    Science.gov (United States)

    ... the penis Psychological causes of delayed ejaculation include: Depression, anxiety or other mental health conditions Relationship problems due to stress, poor communication or other concerns Anxiety about performance Poor body image Cultural or religious taboos Differences between the reality ...

  11. Traumatic Intraventricular Hemorrhage In Severe Blunt Head Trauma: A One Year Analysis

    Directory of Open Access Journals (Sweden)

    G.R. Bahadorkhan

    2006-05-01

    Full Text Available Background:High resolution CT scan has made early diagnosis of intraventricular hemorrhage (IVH easier. Posttraumatic intraventricular hemorrhage has been reported to a greater extent because of the CT scan. Methods:904 patients were admitted in the NSICU from March 2001 to March 2002 with severe closed head injury, of those only 31 patients with intraventricular hemorrhage (GCS less than 8 are reported herein and the mechanism involved is discussed. Results: Nine cases had intracerebral hemorrhage (contusional group, four cases in the frontal lobe, three cases in the temporal lobe and two cases in the parietal lobe. Nine cases (basal ganglia hemorrhage group had hemorrhage in basal ganglia, six in the caudate nucleus and three in the thalamus, all spreading into the ventricles. In thirteen cases the original site of hemorrhage could not be determined. In this group six cases had accompanying peri-brain stem hemorrhage (peri-brain stem hemorrhage group and different brain stem injury signs. Four cases had IVH less than 5 mL with or without minor intracranial lesions (minor intracranial lesion group. Accompanying major intracranial hemorrhage was found in sixteen cases, six cases had epidural hematoma, four cases had subdural hematoma, and seven had a combination of ASDH, EDH and contusional prarenchymal hemorrhages, all requiring primary surgical evacuation, and seven cases had different degrees of minor abnormalities (i.e. minor epidural hemorrhage, minor subdural hemorrhage,sub-arachnoid hemorrhage, minor cortical contusions or subdural effusions which did not need surgical intervention.Two cases had acute hydrocephalus and needed ventricular external drainage. Conclusion:Acceleration-deceleration impact along the long axis of the skull might be the possible mechanism in shearing injury to perforating vessels of the basal ganglia for early appearance of hemorrhage in the caudate nucleus and thalamus. Hemorrhage in basal ganglia and brain

  12. Device-specific evaluation of intraventricular left ventricular assist device position by quantitative coaxiality analysis.

    Science.gov (United States)

    Anselmi, Amedeo; Collin, Sophie; Haigron, Pascal; Verhoye, Jean-Philippe; Flecher, Erwan

    2017-06-01

    Patient-specific anatomy may influence the final intraventricular positioning of inflow cannula in left ventricular assist device (LVAD) recipients. An association exists between such positioning and clinical outcomes (specifically, orientation toward the interventricular septum has negative prognostic implications). Alternative commercially available LVADs are characterized by markedly different design, with potential consequences on intrathoracic fitting among individual patients. A cohort of 13 LVAD recipients (either HeartMate II-group A or Jarvik 2000 Flowmaker-group B) was evaluated. On postoperative computed tomography scans, we reconstructed the implanted LVAD (semiautomatic segmentation), defined the target mitral orifice (3D Slicer software), and built a coordinate system to quantify the coaxiality of the cannula with the mitral valve axis (angles φ and θ, expressed as percentage variation from the ideal value φ = θ = 0°). Group A presented significantly greater average percentage variation of the φ angle (significantly greater orientation of the intraventricular cannula toward the interventricular septum; 33.2% ± 32.1% versus 1.9% ± 0.9%, P = 0.001). Group A presented significantly greater average percentage variation of the θ angle (52.7% ± 23.6% versus 14.5% ± 6.3%, P = 0.013). The device assessed in group B showed in the present series better average coaxiality with the mitral orifice. Such finding is related with its design (total intraventricular placement) and interaction with thoracic structures. The present method is being integrated in the development of LVAD virtual implantation tools and may help physicians in patient-specific selection among alternative devices. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Quantification of intraventricular hemorrhage is consistent using a spherical sensitivity matrix

    Science.gov (United States)

    Tang, Te; Sadleir, Rosalind

    2010-04-01

    We have developed a robust current pattern for detection of intraventricular hemorrhage (IVH). In this study, the current pattern was applied on two realistic shaped neonatal head models and one head-shaped phantom. We found that a sensitivity matrix calculated from a spherical model gave us satisfactory reconstructions in terms of both image quality and quantification. Incorporating correct geometry information into the forward model improved image quality. However, it did not improve quantification accuracy. The results indicate that using a spherical matrix may be a more practical choice for monitoring IVH volumes in neonates.

  14. Post-surgical meningitis due to multiresistant Acinetobacter baumannii. Effective treatment with intravenous and/or intraventricular colistin and therapeutic dilemmas.

    Science.gov (United States)

    Paramythiotou, E; Karakitsos, D; Aggelopoulou, H; Sioutos, P; Samonis, G; Karabinis, A

    2007-02-01

    Post-surgical meningitis and/or ventriculitis caused by Gram-negative bacteria may be difficult to treat due to the emergence of multiresistant strains. Two patients with multiresistant Acinetobacter baumannii central nervous system infection, successfully treated with either intravenous and/or intraventricular colistin are presented. Unresolved issues such as dose and duration of intraventricular colistin are discussed.

  15. Intraventricular ciprofloxacin usage in treatment of multidrug-resistant central nervous system infections: report of four cases

    Directory of Open Access Journals (Sweden)

    Ayse Karaaslan

    2014-12-01

    Full Text Available In recent years, multidrug-resistant microorganisms appear as important nosocomial pathogens which treatment is quite difficult. As sufficient drug levels could not be achieved in cerebrospinal fluid during intravenous antibiotic therapy for central nervous system infections and due to multidrug-resistance treatment alternatives are limited. In this study, four cases of central nervous system infections due to multidrug-resistant microorganisms who were successfully treated with removal of the devices and intraventricular ciprofloxacin are presented. In conclusion, intraventricular ciprofloxacin can be used for treatment of central nervous system infections if the causative microorganism is sensitive to the drug and no other alternative therapy is available.

  16. Prolonged hydrocephalus induced by intraventricular hemorrhage in rats is reduced by curcumin therapy.

    Science.gov (United States)

    Qi, Zhihua; Zhang, Huiqin; Fu, Chuhua; Liu, Xiao; Chen, Bo; Dang, Yanwei; Chen, Huayun; Liu, Lijun

    2017-01-10

    Prolonged hydrocephalus is a major cause of severe disability and death of intraventricular hemorrhage (IVH) patients. However, the therapeutic options to minimize the detrimental effects of post-hemorrhagic hydrocephalus are limited. Curcumin has been reported to confer neuroprotective effects in numerous neurological diseases and injuries, but its role in IVH-induced hydrocephalus has not been determined. The aim of present study was to determine whether curcumin treatment ameliorates blood brain barrier (BBB) damage and reduces the incidence of post-hemorrhagic hydrocephalus in IVH rat model. Autologous blood intraventricular injection was used to establish the IVH model. Our results revealed that repeated intraperitoneal injection of curcumin ameliorated IVH-induced learning and memory deficits as determined by Morris water maze and reduced the incidence of post-hemorrhagic hydrocephalus in a dose-dependent manner at 28 d post-IVH induction. Further, the increased BBB permeability and brain edema induced by IVH were significantly reduced by curcumin administration. In summary, these findings highlighted the important role of curcumin in improving neurological function deficits and protecting against BBB disruption via promoting the neurovascular unit restoration, and thus it reduced the severity of post-hemorrhagic hydrocephalus in the long term. It is believed that curcumin might prove to be an effective therapeutic component in prevent the post-IVH hydrocephalus in the near future. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. High-field spin-echo MR imaging of superficial and subependymal siderosis secondary to neonatal intraventricular hemorrhage

    International Nuclear Information System (INIS)

    Gomori, J.M.; Grossman, R.I.; Goldberg, H.I.; Zimmerman, R.A.; Bilaniuk, L.T.

    1987-01-01

    Two cases of superficial siderosis with subependymal siderosis, secondary to neonatal intraventricular hemorrhage, are presented. High-field spin-echo MR imaging (1.5 Tesla) showed marginal hypointensity of the ventricular walls as well as of the subpial regions. These findings were most evident on T 2 weighted images, characteristic of hemosiderotic deposits. (orig.)

  18. Alteplase (rtPA) treatment of intraventricular hematoma (IVH): safety of an efficient methodological approach for rapid clot removal

    DEFF Research Database (Denmark)

    Bartek, Jiri Jr.; Hansen-Schwartz, J; Bergdal, Ove Ketil

    2011-01-01

    Intraventricular hemorrhage (IVH) subsequent to intracerebral hemorrhage (ICH) or subarachnoid hemorrhage (SAH) is associated with high mortality and morbidity. The use of fibrinolytic agents to treat this condition has previously been reported in small clinical trials with limited numbers of pat...

  19. Tranport of p-aminohippuric acid (/sup 3/H-PAH), inulin and dextran out of the cranial cavity: A methodological study using intraventricular injection and sample combustion

    Energy Technology Data Exchange (ETDEWEB)

    Jakobson, Aa. M.

    1987-01-01

    Material injected into the cerebral ventricles can leave the cerebrospinal fluid (CSF) but remain in the cranial cavity. To analyze the disappearance of /sup 3/H- and of /sup 14/C-labelled material from the cranial cavity, such material was injected into the lateral ventricles together with a bulk flow marker, labelled with the other radionuclide. In the present pilot study /sup 3/H-PAH and /sup 14/C-inulin were used. Five ..mu..l of a mixture was injected into each lateral cerebral ventricles in rats, which were killed at various intervals. The whole skull was analyzed without opening the CSF space after homogenization in the deep-frozen state. The samples were combusted and analyzed by liquid scintillation counting. Probenecid, injected intraperitoneally, inhibited the removal of /sup 3/H-PAH from the skull cavity, as anticipated. Immediately after the intraventricular injection, however, /sup 3/H-PAH was transiently retained, probably by uptake into actively transporting tissue. After injection of probenecid, this delay in removal was reduced. The difference in disappearance rate between /sup 3/H-PAH and /sup 14/C-inulin was estimated by comparing the /sup 3/H//sup 14/C ratio in the skulls with that in the injected solution, which appeared to be a better method than comparing the recovery of each compound.

  20. Tranport of p-aminohippuric acid (3H-PAH), inulin and dextran out of the cranial cavity: A methodological study using intraventricular injection and sample combustion

    International Nuclear Information System (INIS)

    Jakobson, Aa. M.

    1987-01-01

    Material injected into the cerebral ventricles can leave the cerebrospinal fluid (CSF) but remain in the cranial cavity. To analyze the disappearance of 3 H- and of 14 C-labelled material from the cranial cavity, such material was injected into the lateral ventricles together with a bulk flow marker, labelled with the other radionuclide. In the present pilot study 3 H-PAH and 14 C-inulin were used. Five μl of a mixture was injected into each lateral cerebral ventricles in rats, which were killed at various intervals. The whole skull was analyzed without opening the CSF space after homogenization in the deep-frozen state. The samples were combusted and analyzed by liquid scintillation counting. Probenecid, injected intraperitoneally, inhibited the removal of 3 H-PAH from the skull cavity, as anticipated. Immediately after the intraventricular injection, however, 3 H-PAH was transiently retained, probably by uptake into actively transporting tissue. After injection of probenecid, this delay in removal was reduced. The difference in disappearance rate between 3 H-PAH and 14 C-inulin was estimated by comparing the 3 H/ 14 C ratio in the skulls with that in the injected solution, which appeared to be a better method than comparing the recovery of each compound. (author)

  1. Neuroendoscopic Resection of Intraventricular Tumors and Cysts through a Working Channel with a Variable Aspiration Tissue Resector: A Feasibility and Safety Study

    Directory of Open Access Journals (Sweden)

    Edjah Kweku-Ebura Nduom

    2013-01-01

    Full Text Available Pure neuroendoscopic resection of intraventricular lesions through a burr hole is limited by the instrumentation that can be used with a working channel endoscope. We describe a safety and feasibility study of a variable aspiration tissue resector, for the resection of a variety of intraventricular lesions. Our initial experience using the variable aspiration tissue resector involved 16 patients with a variety of intraventricular tumors or cysts. Nine patients (56% presented with obstructive hydrocephalus. Patient ages ranged from 20 to 88 years (mean 44.2. All patients were operated on through a frontal burr hole, using a working channel endoscope. A total of 4 tumors were resected in a gross total fashion and the remaining intraventricular lesions were subtotally resected. Fifteen of 16 patients had relief of their preoperative symptoms. The 9 patients who presented with obstructive hydrocephalus had restoration of cerebrospinal fluid flow though one required a ventriculoperitoneal shunt. Three patients required repeat endoscopic resections. Use of a variable aspiration tissue resector provides the ability to resect a variety of intraventricular lesions in a safe, controlled manner through a working channel endoscope. Larger intraventricular tumors continue to pose a challenge for complete removal of intraventricular lesions.

  2. Intraventricular glioneuronal tumor with disseminated lesions at diagnosis--a case report.

    Science.gov (United States)

    Yano, Hirohito; Nakayama, Noriyuki; Hirose, Yoshinobu; Ohe, Naoyuki; Shinoda, Jun; Yoshimura, Shin-ichi; Iwama, Toru

    2011-12-06

    A 55-year-old man presented with a large tumor in his lateral ventricles. Magnetic resonance imaging revealed disseminated lesions in the third and fourth ventricles at the time of diagnosis. The patient underwent a partial removal of the tumor in the lateral ventricles. Histologically, the surgical specimens showed glioneuronal differentiation with ganglion or ganglioid cells, Rosenthal fibers, oligodendroglia-like honeycomb appearances, a spongy pattern, perivascular pseudorosettes, and many hyalinized blood vessels. Papillary structure was not observed. The neuronal component showed a moderately high labeling index of Ki-67/MIB-1. We diagnosed this tumor as atypical intraventricular glioneuronal tumor. The disseminated lesions disappeared after chemoradiation therapy with temozolomide, and the residual tumors in the lateral ventricles remained stable for 3 years after the surgery. We discuss the pathological diagnosis, therapy and clinical course with review of the literatures.

  3. Intraventricular glioneuronal tumor with disseminated lesions at diagnosis - a case report -

    Directory of Open Access Journals (Sweden)

    Yano Hirohito

    2011-12-01

    Full Text Available Abstract A 55-year-old man presented with a large tumor in his lateral ventricles. Magnetic resonance imaging revealed disseminated lesions in the third and fourth ventricles at the time of diagnosis. The patient underwent a partial removal of the tumor in the lateral ventricles. Histologically, the surgical specimens showed glioneuronal differentiation with ganglion or ganglioid cells, Rosenthal fibers, oligodendroglia-like honeycomb appearances, a spongy pattern, perivascular pseudorosettes, and many hyalinized blood vessels. Papillary structure was not observed. The neuronal component showed a moderately high labeling index of Ki-67/MIB-1. We diagnosed this tumor as atypical intraventricular glioneuronal tumor. The disseminated lesions disappeared after chemoradiation therapy with temozolomide, and the residual tumors in the lateral ventricles remained stable for 3 years after the surgery. We discuss the pathological diagnosis, therapy and clinical course with review of the literatures.

  4. Solid Right Ventricular Compression by Intraventricular Septum-Hematoma Induced after Percutaneous Coronary Intervention

    Directory of Open Access Journals (Sweden)

    Ibrahim El-Battrawy

    2016-01-01

    Full Text Available Intraventricular septum-hematoma is a rare complication following percutaneous coronary intervention (PCI. This complication may represent a challenge for accurate diagnosis and treatment. This case report is about a 60-year-old male patient being admitted with an acute coronary syndrome. Despite successful PCI with drug eluting stent implantation into the right coronary artery (RCA the patient complained about recurrent angina pectoris according to Canadian Cardiovascular Society (CCS class IV. Cardiac magnetic resonance imaging and transthoracic echocardiography revealed a massive 4.9×9.2 cm sized end-diastolic septum-hematoma, which compromised right ventricular cavity. Emergent recoronary angiography ruled out further contrast extravasation from the RCA. Conservative treatment was intended after discussion in the “heart-team.” The patient completely recovered with nearly complete resolution of the hematoma after 6 months.

  5. Quantification of intraventricular hemorrhage with electrical impedance tomography using a spherical model

    International Nuclear Information System (INIS)

    Tang, T; Sadleir, R J

    2011-01-01

    We have developed a robust EEG-based current pattern which shows promise for the detection of intraventricular hemorrhage (IVH) in neonates. Our reconstructions to date are based on a layered spherical head model. In this study, the current pattern was used to gather data from three realistic-shaped neonatal head models and a physical phantom based on one of these models. We found that a sensitivity matrix calculated from a spherical model gave us satisfactory reconstructions in terms of both image quality and quantification. Incorporating correct geometry information into the forward model improved image quality. However, it did not improve quantification accuracy. The results indicate that using a spherical matrix may be a more practical choice for monitoring IVH volumes in neonates for whom patient-specific models are not available

  6. Intraventricular gradient during effort in a professional soccer player. Clinical significance.

    Science.gov (United States)

    Cotrim, Carlos; Loureiro, M José; Simões, Otília; Cordeiro, Pedro; Henriksson, Isabel; Vinhas, Hugo; Almeida, Ana; Carrageta, Manuel

    2005-11-01

    The authors report the case of a 20-year-old professional soccer player who underwent medical evaluation because of atypical chest discomfort and dizziness precipitated by strenuous effort. The ECG and echocardiogram findings were normal. The young athlete did a treadmill stress test which was negative for myocardial ischemia. His myocardial perfusion imaging and coronary angiography were also normal. Later during the investigation, he underwent treadmill stress echocardiography, during which he developed an intraventricular gradient of over 100 mmHg with end-systolic peak and systolic anterior movement (SAM) of the mitral valve. These echocardiographic findings were not present at rest and disappeared shortly after termination of exercise. The authors discuss the significance of these findings and their potential link to sudden death.

  7. On estimating intraventricular hemodynamic forces from endocardial dynamics: A comparative study with 4D flow MRI.

    Science.gov (United States)

    Pedrizzetti, Gianni; Arvidsson, Per M; Töger, Johannes; Borgquist, Rasmus; Domenichini, Federico; Arheden, Håkan; Heiberg, Einar

    2017-07-26

    Intraventricular pressure gradients or hemodynamic forces, which are their global measure integrated over the left ventricular volume, have a fundamental importance in ventricular function. They may help revealing a sub-optimal cardiac function that is not evident in terms of tissue motion, which is naturally heterogeneous and variable, and can influence cardiac adaptation. However, hemodynamic forces are not utilized in clinical cardiology due to the unavailability of simple non-invasive measurement tools. Hemodynamic forces depend on the intraventricular flow; nevertheless, most of them are imputable to the dynamics of the endocardial flow boundary and to the exchange of momentum across the mitral and aortic orifices. In this study, we introduce a simplified model based on first principles of fluid dynamics that allows estimating hemodynamic forces without knowing the velocity field inside the LV. The model is validated with 3D phase-contrast MRI (known as 4D flow MRI) in 15 subjects, (5 healthy and 10 patients) using the endocardial surface reconstructed from the three standard long-axis projections. Results demonstrate that the model provides consistent estimates for the base-apex component (mean correlation coefficient r=0.77 for instantaneous values and r=0.88 for root mean square) and good estimates of the inferolateral-anteroseptal component (r=0.50 and 0.84, respectively). The present method represents a potential integration to the existing ones quantifying endocardial deformation in MRI and echocardiography to add a physics-based estimation of the corresponding hemodynamic forces. These could help the clinician to early detect sub-clinical diseases and differentiate between different cardiac dysfunctional states. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. CT findings and prognosis of spontaneous (hypertensive) intracerebralhematoma associated with intraventricular perforation

    International Nuclear Information System (INIS)

    Sogabe, Koichiro; Gyoten, Tetsuya; Masuda, Tsutomu; Hondo, Hideki; Matsumoto, Keizo

    1982-01-01

    The prognosis of spontaneous hypertensive intracerebral hematoma associated with the intraventricular hemorrhage were discussed with the base of computerized tomography (CT) findings in their acute stage. 104 (47%) out of 219 patients with hypertensive intracerebral hemorrhage revealed intraventricular hemorrhage in our service from January 1978 to December 1980. In these cases infratentorial, cerebellar and pontine hemorrhage were not included. Namely, 22 out of 93 cases of putaminal hemorrhage, 47 out of 61 cases in thalamic type, 30 out of 39 cases in combined type and 5 out of 26 cases in subcortical type were demonstrated the ventricular hemorrhage by CT examination, respectively. In early period of CT utilization, the ventricular hemorrhage had generally been accepted as one of serious signs from the knowledges, which had been obtained from postmortem examination in such cases. Recent experiences, however, suggested that cases of intracerebral hematoma with the ventricle rupture were not always resulted to the poor prognosis. Cases, which had extension of the hematoma to the 3rd and 4th ventricle, were clearly divided into two contradictory group, namely, poor and good prognostic group. They showed nearly equal occurance. However, it was noted that cases with the cast formation below the third ventricle resulted poor prognosis. Statistical analysis of our cases led the following conclusions i.e. the influencing factors of the poor outcome are: hematoma size is larger than 3x3 cm, combination of acute ventricular enlargement, disappearance of the ambient cistern and hypothalamic extension of hematoma; cast formation of blood in the 3rd and 4th ventricle. (J.P.N.)

  9. Early recognition of intraventricular hemorrhage in the setting of thrombocytosis in the emergency department

    Directory of Open Access Journals (Sweden)

    Charles M

    2016-05-01

    Full Text Available Marvinia Charles, Romy Fontoura, Gregory Sugalski Department of Emergency Medicine, Rutgers New Jersey Medical School, Newark, NJ, USA Abstract: Thrombocytosis is frequently encountered as an incidental laboratory finding since isolated thrombocytosis is often asymptomatic. Even though thrombocytosis is benign and self-limiting in most cases, it can at times result in thrombosis or hemorrhage. The most common type of thrombocytosis is reactive (secondary thrombocytosis and can be due to infections, trauma, surgery, or occult malignancy. Since thrombocytosis is a known risk factor for thrombosis, it is commonly a concern for ischemic stroke and myocardial infarction. Much less common are hemorrhagic events associated with thrombocytosis. Studies have shown that when hemorrhage is present in patients with thrombocytosis, it is most often seen in the setting of chronic myelogenous leukemia and essential thrombocythemia. In essential thrombocythemia, the overall risk of bleeding and thrombosis is 0.33% per patient-year and 6.6% per patient-year, respectively. In the general population, the risk of bleeding and thrombosis is 0% and 1.2%, respectively. The present study is a case report of an 83-year-old man who presented to the emergency department with hypertension and headache, who was then found to have significant thrombocytosis (platelets >1,000×109/L and acute right intraventricular hemorrhage without any signs of neurological deficits, or evidence of vascular malformations or mass. We present this case report for review and discussion of some of the challenges and considerations associated with the management of such patients. Keywords: thrombocytosis, thrombocythemia, hemorrhage, intraventricular hemorrhage, thrombosis, headache, emergency department

  10. Neurotoxicity in conscious rats following intraventricular SNAP, a nitric oxide donor.

    Science.gov (United States)

    Gross, P M; Weaver, D F; Bowers, R J; Nag, S; Ho, L T; Pang, J J; Espinosa, F J

    1994-07-01

    A solution containing S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide (NO.-releasing compound, was microinjected in doses of 0.25-2 mumol into a lateral ventricle of conscious rats. SNAP produced dose-dependent convulsions similar to those associated with limbic stimulation, such as tonic extension of the hindlimbs and tail, and dystonia of the forepaws. At 2 mumol, SNAP evoked hyperventilation (arterial hypocapnia), arterial hyperglycemia and caused necrotic lesions of periventricular gray (e.g. lateral septal nucleus) and white matter structures. In the caudate nucleus and lateral septal nucleus ipsilateral to injection, SNAP elicited a bipolar metabolic pattern of low glucose metabolism proximal to the ventricle with higher values occurring more distally. In control studies, we proved that the residue of SNAP decomposition, N-acetylpenicillamine disulfide injected intraventricularly (2 mumol), was without physiological, behavioral, or histological effects. Ventricular pretreatment with methylene blue (2 nmol), a putative inhibitor of guanylate cyclase and superoxide generator, suppressed several of the behavioral manifestations of 1 mumol SNAP, such as the forepaw dystonia, squinting, and facial clonus, but was ineffective on the physiological and histological variables affected by the 2 mumol SNAP dose. Another NO. donor, sodium nitroprusside (2 mumol), produced fewer behavioral and cytotoxic effects over a 55-min observation period, but caused more intense and widely distributed metabolic stimulation, especially in commissural and projection white matter tracts. The results are the basis for a conscious rat model using intraventricular injection of nitrocompounds to examine the physiological, behavioral, metabolic and cytotoxic properties of NO. in the brain.

  11. Neurocitoma central com apresentação incomum por hemorragia intraventricular: relato de caso

    Directory of Open Access Journals (Sweden)

    Hanel Ricardo Alexandre

    2001-01-01

    Full Text Available O neurocitoma central foi descrito pela primeira vez na literatura em 1982 por Hassoun e colaboradores como tumor bem diferenciado de origem neuronal. O tumor geralmente localiza-se no sistema ventricular, afetando adultos jovens e geralmente cursando com hipertensão intracraniana secundária à hidrocefalia obstrutiva. O diagnóstico diferencial com outros processos intraventriculares como oligodendroglioma é realizado através de métodos imuno-histoquímicos. Raros casos de neurocitoma central associados com hemorragia têm sido descritos na literatura. Descrevemos um caso de neurocitoma central de uma paciente de 35 anos com apresentação atípica. A paciente havia procurado o hospital com quadro súbito de cefaléia, vômitos e rigidez de nuca, sugerindo a presença de hemorragia subaracnóidea. A ressonância magnética demonstrou volumosa massa no ventrículo lateral direito cujos perfis histológico e imuno-histoquímico eram condizentes com neurocitoma central, a ressecção cirúrgica foi realizada com sucesso, embora a paciente tenha evoluído para um quadro de ventriculite no pós-operatório. Salientamos a importância do estabelecimento do neurocitoma central como diagnóstico diferencial de pacientes com hemorragia intraventricular e discutimos as opções de tratamento para este tumor incomum.

  12. Conduction Abnormalities and Pacemaker Implantations After SAPIEN 3 Vs SAPIEN XT Prosthesis Aortic Valve Implantation.

    Science.gov (United States)

    Husser, Oliver; Kessler, Thorsten; Burgdorf, Christof; Templin, Christian; Pellegrini, Costanza; Schneider, Simon; Kasel, Albert Markus; Kastrati, Adnan; Schunkert, Heribert; Hengstenberg, Christian

    2016-02-01

    Transcatheter aortic valve implantation is increasingly used in patients with aortic stenosis. Post-procedural intraventricular conduction abnormalities and permanent pacemaker implantations remain a serious concern. Recently, the Edwards SAPIEN 3 prosthesis has replaced the SAPIEN XT. We sought to determine the incidences of new-onset intraventricular conduction abnormalities and permanent pacemaker implantations by comparing the 2 devices. We analyzed the last consecutive 103 patients undergoing transcatheter aortic valve implantation with SAPIEN XT before SAPIEN 3 was used in the next 105 patients. To analyze permanent pacemaker implantations and new-onset intraventricular conduction abnormalities, patients with these conditions at baseline were excluded. Electrocardiograms were recorded at baseline, after the procedure, and before discharge. SAPIEN 3 was associated with higher device success (100% vs 92%; P=.005) and less paravalvular leakage (0% vs 7%; P<.001). The incidence of permanent pacemaker implantations was 12.6% (23 of 183) with no difference between the 2 groups (SAPIEN 3: 12.5% [12 of 96] vs SAPIEN XT: 12.6% [11 of 87]; P=.99). SAPIEN 3 was associated with a higher rate of new-onset intraventricular conduction abnormalities (49% vs 27%; P=.007) due to a higher rate of fascicular blocks (17% vs 5%; P=.021). There was no statistically significant difference in transient (29% [20 of 69] vs persistent 19% [12 of 64]; P=.168) left bundle branch blocks (28% [19 of 69] vs 17% [11 of 64]; P=.154) when SAPIEN 3 was compared with SAPIEN XT. We found a trend toward a higher rate of new-onset intraventricular conduction abnormalities with SAPIEN 3 compared with SAPIEN XT, although this did not result in a higher permanent pacemaker implantation rate. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  13. Intraventricular Hemorrhage Due to Coagulopathy After Vitamin K Administration in a Preterm Infant With Maternal Crohn Disease

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    Kazumichi Fujioka

    2017-12-01

    Full Text Available Intraventricular hemorrhage (IVH is a devastating morbidity in preterm infants and can result in poor neurodevelopmental outcomes. Intraventricular hemorrhage usually occurs within 72 hours after birth; post–acute-phase IVH (>1 week after birth is uncommon. Development of the hemostatic system in fetuses and neonates is an age-dependent evolving process, and the neonatal hemostatic system is characterized by low levels of vitamin K–dependent factors, with further reduction caused by prematurity. Importantly, a severe coagulation deficiency can be a major contributing factor of IVH. Active maternal Crohn disease (CD during pregnancy causes malnutrition via enteral malabsorption; this may include vitamin K deficiency, resulting in fetal vitamin K deficiency. We herein describe a preterm infant who was born to a mother with CD and developed post–acute-phase IVH due to coagulopathy despite vitamin K administration.

  14. E-wave generated intraventricular diastolic vortex to L-wave relation: model-based prediction with in vivo validation.

    Science.gov (United States)

    Ghosh, Erina; Caruthers, Shelton D; Kovács, Sándor J

    2014-08-01

    The Doppler echocardiographic E-wave is generated when the left ventricle's suction pump attribute initiates transmitral flow. In some subjects E-waves are accompanied by L-waves, the occurrence of which has been correlated with diastolic dysfunction. The mechanisms for L-wave generation have not been fully elucidated. We propose that the recirculating diastolic intraventricular vortex ring generates L-waves and based on this mechanism, we predict the presence of L-waves in the right ventricle (RV). We imaged intraventricular flow using Doppler echocardiography and phase-contrast magnetic resonance imaging (PC-MRI) in 10 healthy volunteers. L-waves were recorded in all subjects, with highest velocities measured typically 2 cm below the annulus. Fifty-five percent of cardiac cycles (189 of 345) had L-waves. Color M-mode images eliminated mid-diastolic transmitral flow as the cause of the observed L-waves. Three-dimensional intraventricular flow patterns were imaged via PC-MRI and independently validated our hypothesis. Additionally as predicted, L-waves were observed in the RV, by both echocardiography and PC-MRI. The re-entry of the E-wave-generated vortex ring flow through a suitably located echo sample volume can be imaged as the L-wave. These waves are a general feature and a direct consequence of LV and RV diastolic fluid mechanics. Copyright © 2014 the American Physiological Society.

  15. Absceso cerebral complicado con ruptura intraventricular: reporte de dos casos y revisión de la literatura

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    Jorge Alonso Ramírez Quiñones

    2014-04-01

    Full Text Available El absceso cerebral es una patología infecciosa infrecuente cuyo diagnóstico oportuno y tratamiento adecuado conducen a un buen pronóstico en la mayoría de los casos. La ruptura intraventricular es una complicación rara del absceso cerebral con elevada mortalidad; se caracteriza por compromiso brusco de la conciencia, con aparición de signos de irritación meníngea y hallazgos radiológicos compatibles con un drenaje de secreción purulenta hacia los ventrículos. El tratamiento incluye la administración de antibióticos intravenosos e intratecales asociados a una rápida intervención quirúrgica para drenaje del absceso y del contenido intraventricular. Presentamos dos casos de absceso cerebral complicado con ruptura intraventricular, que mostraron características clínicas y radiológicas propias de esta condición, con evolución favorable solo con tratamiento antibiótico endovenoso durante seis a diez semanas, respectivamente.

  16. Intraventricular pneumocephalus associated with nasocephalic necrosis in a puppy: a case report

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    J.O. Sena

    Full Text Available ABSTRACT Pneumocephalus is defined as the presence of air in any of the intracranial compartments. Its most frequent causes are trauma and cranial surgery. Clinical signs occur as a result of increased intracranial pressure and vary with the location and extent of the lesion. A case involving a seven-month-old female Saint Bernard, who suffered cranial trauma caused by a bite to the face at ten days of age and had presented with seizures and localized pain four months previously is reported. A computed tomography scan of the skull revealed a nasocephalic mass with low contrast enhancement, bone lysis, and hypodensity (-940 Hounsfield units of the lateral and third ventricles, indicating intraventricular pneumocephalus. During surgery, a fragment of the mass was collected for histopathological examination, which demonstrated the presence of multifocal areas of necrosis. The computed tomography (CT is a reliable method for the characterization of intracranial lesions and diagnosis of pneumocephalus, whose occurrence must be considered in pathological processes in which there is increased intracranial pressure and in patients undergoing certain surgical procedures and anesthetic specific, and CT is indicated as a monitoring tool for these patients.

  17. MR Spectroscopy to Distinguish between Supratentorial Intraventricular Subependymoma and Central Neurocytoma.

    Science.gov (United States)

    Ueda, Fumiaki; Aburano, Hiroyuki; Ryu, Yasuji; Yoshie, Yuichi; Nakada, Mitsutoshi; Hayashi, Yutaka; Matsui, Osamu; Gabata, Toshifumi

    2017-07-10

    The purpose of this study was to discriminate supratentorial intraventricular subependymoma (SIS) from central neurocytoma (CNC) using magnetic resonance spectroscopy (MRS). Single-voxel proton MRS using a 1.5T or 3T MR scanner from five SISs, five CNCs, and normal controls were evaluated. They were examined using a point-resolved spectroscopy. Automatically calculated ratios comparing choline (Cho), N-acetylaspartate (NAA), myoinositol (MI), and/or glycine (Gly) to creatine (Cr) were determined. Evaluation of Cr to unsuppressed water (USW) was also performed. Mann-Whitney U test was carried out to test the significance of differences in the metabolite ratios. Detectability of lactate (Lac) and alanine (Ala) was evaluated. Although a statistically significant difference (P CNC, no statistical difference was noted between SIS and control spectra (P = 0.11). Statistically significant differences were observed in NAA/Cr between SIS and CNC (P = 0.04) or control spectra (P CNC and control spectra (P CNC for MI and/or Gly to Cr (P = 0.32). Significant statistical differences were found between SIS and control spectra (P CNC (P CNC (P CNC. The present study showed that MRS can be useful in discriminating SIS from CNC.

  18. Intraventricular hemorrhage on initial computed tomography as marker of diffuse axonal injury after traumatic brain injury.

    Science.gov (United States)

    Mata-Mbemba, Daddy; Mugikura, Shunji; Nakagawa, Atsuhiro; Murata, Takaki; Kato, Yumiko; Tatewaki, Yasuko; Li, Li; Takase, Kei; Ishii, Kiyoshi; Kushimoto, Shigeki; Tominaga, Teiji; Takahashi, Shoki

    2015-03-01

    Intraventricular hemorrhage (IVH) on initial computed tomography (CT) was reported to predict lesions of diffuse axonal injury (DAI) in the corpus callosum (CC) on subsequent magnetic resonance imaging (MRI). We aimed to examine the relationship between initial CT findings and DAI lesions detected on MRI as well as the relationship between the severity of IVH (IVH score) and severity of DAI (DAI staging). A consecutive 140 patients with traumatic brain injury (TBI) who underwent MRI within 30 days after onset were revisited. We reviewed their initial CT for the following six findings: Status of basal cistern, status of mid-line shift, epidural hematoma, IVH, subarachnoid hemorrhage, and volume of hemorrhagic mass and IVH score were assigned in each patient. Based on MRI findings, patients were divided into DAI and non-DAI groups and were assigned a DAI staging. Then, to confirm that the IVH on initial CT predicts DAI lesions on MRI, we used multi-variate analysis of the six CT findings, including IVH, and examined the relationship between IVH score and DAI staging. The IVH detected on CT was the only predictor of DAI (p=0.0139). The IVH score and DAI staging showed significant positive correlation (pbrain stem; p=0.0025) or stage 2 (with DAI involving CC; p=0.0042) was significantly higher than that of DAI stage 0 (no DAI lesions). In conclusion, IVH on initial CT is the only marker of DAI on subsequent MRI, specifically severe DAI (stage 2 or 3).

  19. Skin blood flow as a predictor of intraventricular hemorrhage in very-low-birth-weight infants.

    Science.gov (United States)

    Ishiguro, Akio; Suzuki, Keiji; Sekine, Takashi; Sudo, Yousuke; Kawasaki, Hidenori; Itoh, Kanako; Kanai, Masayo; Kato, Ineko; Sobajima, Hisanori; Tamura, Masanori

    2014-02-01

    Cardiovascular instability immediately after birth is associated with intraventricular hemorrhage (IVH) in very-low-birth-weight (VLBW) infants. For circulatory management, evaluation of organ blood flow is important. In this study, the relationship between peripheral perfusion within 48 h after birth and IVH was evaluated in VLBW infants. In this prospective observational study involving 83 VLBW infants, forehead blood flow (FBF) and lower-limb blood flow (LBF) were measured for 48 h after birth using a laser Doppler flowmeter. Blood flow was compared between infants with and without IVH. Multivariate logistic regression analysis was performed to identify the risk factors for IVH. IVH developed in nine infants. In eight of these patients, IVH occurred after 24 h. LBF was lower in infants with IVH at 18 and 24 h and increased to the same level as that of infants without IVH at 48 h. Multivariate logistic regression analysis identified a correlation only between LBF and IVH at 18 h. These findings were consistent with the hypoperfusion-reperfusion theory, which states that IVH develops after reperfusion subsequent to hypoperfusion. We speculate that measurement of skin blood flow in addition to systemic and cerebral circulation may be helpful in predicting IVH.

  20. 3D ultrasound system to investigate intraventricular hemorrhage in preterm neonates

    Science.gov (United States)

    Kishimoto, J.; de Ribaupierre, S.; Lee, D. S. C.; Mehta, R.; St. Lawrence, K.; Fenster, A.

    2013-11-01

    Intraventricular hemorrhage (IVH) is a common disorder among preterm neonates that is routinely diagnosed and monitored by 2D cranial ultrasound (US). The cerebral ventricles of patients with IVH often have a period of ventricular dilation (ventriculomegaly). This initial increase in ventricle size can either spontaneously resolve, which often shows clinically as a period of stabilization in ventricle size and eventual decline back towards a more normal size, or progressive ventricular dilation that does not stabilize and which may require interventional therapy to reduce symptoms relating to increased intracranial pressure. To improve the characterization of ventricle dilation, we developed a 3D US imaging system that can be used with a conventional clinical US scanner to image the ventricular system of preterm neonates at risk of ventriculomegaly. A motorized transducer housing was designed specifically for hand-held use inside an incubator using a transducer commonly used for cranial 2D US scans. This system was validated using geometric phantoms, US/MRI compatible ventricle volume phantoms, and patient images to determine 3D reconstruction accuracy and inter- and intra-observer volume estimation variability. 3D US geometric reconstruction was found to be accurate with an error of 0.05) for the measured ventricle volumes between observers. This 3D US system can reliably produce 3D US images of the neonatal ventricular system. There is the potential to use this system to monitor the progression of ventriculomegaly over time in patients with IVH.

  1. Characterization of neonatal patients with intraventricular hemorrhage using 3D ultrasound cerebral ventricle volumes

    Science.gov (United States)

    Kishimoto, Jessica; Fenster, Aaron; Lee, David S. C.; de Ribaupierre, Sandrine

    2015-03-01

    One of the major non-congenital cause of neurological impairment among neonates born very preterm is intraventricular hemorrhage (IVH) - bleeding within the lateral ventricles. Most IVH patients will have a transient period of ventricle dilation that resolves spontaneously. However, those patients most at risk of long-term impairment are those who have progressive ventricle dilation as this causes macrocephaly, an abnormally enlarged head, then later causes increases intracranial pressure (ICP). 2D ultrasound (US) images through the fontanelles of the patients are serially acquired to monitor the progression of the ventricle dilation. These images are used to determine when interventional therapies such as needle aspiration of the built up CSF might be indicated for a patient. Initial therapies usually begin during the third week of life. Such interventions have been shown to decrease morbidity and mortality in IVH patients; however, this comes with risks of further hemorrhage or infection; therefore only patients requiring it should be treated. Previously we have developed and validated a 3D US system to monitor the progression of ventricle volumes (VV) in IVH patients. This system has been validated using phantoms and a small set of patient images. The aim of this work is to determine the ability of 3D US generated VV to categorize patients into those who will require interventional therapies, and those who will have spontaneous resolution. Patients with higher risks could therefore be monitored better, by re-allocating some of the resources as the low risks infants would need less monitoring.

  2. Quantitative head ultrasound measurements to determine thresholds for preterm neonates requiring interventional therapies following intraventricular hemorrhage

    Science.gov (United States)

    Kishimoto, Jessica; Fenster, Aaron; Salehi, Fateme; Romano, Walter; Lee, David S. C.; de Ribaupierre, Sandrine

    2016-04-01

    Dilation of the cerebral ventricles is a common condition in preterm neonates with intraventricular hemorrhage (IVH). This post hemorrhagic ventricle dilation (PHVD) can lead to lifelong neurological impairment through ischemic injury due to increased intracranial pressure and without treatment, can lead to death. Clinically, 2D ultrasound (US) through the fontanelles ('soft spots') of the patients are serially acquired to monitor the progression of the ventricle dilation. These images are used to determine when interventional therapies such as needle aspiration of the built up cerebrospinal fluid (CSF) ('ventricle tap', VT) might be indicated for a patient; however, quantitative measurements of the growth of the ventricles are often not performed. There is no consensus on when a neonate with PHVD should have an intervention and often interventions are performed after the potential for brain damage is quite high. Previously we have developed and validated a 3D US system to monitor the progression of ventricle volumes (VV) in IVH patients. We will describe the potential utility of quantitative 2D and 3D US to monitor and manage PHVD in neonates. Specifically, we will look to determine image-based measurement thresholds for patients who will require VT in comparison to patients with PHVD who resolve without intervention. Additionally, since many patients who have an initial VT will require subsequent interventions, we look at the potential for US to determine which PHVD patients will require additional VT after the initial one has been performed.

  3. Intraventricular Hemorrhage and Post Hemorrhagic Hydrocephalus among Very-Low-Birth-Weight Infants in Korea.

    Science.gov (United States)

    Ahn, So Yoon; Shim, So-Yeon; Sung, In Kyung

    2015-10-01

    Here, we aimed to evaluate the incidence and mortality of intraventricular hemorrhage (IVH) and post-hemorrhagic hydrocephalus (PHH) among very-low-birth-weight (VLBW) infants in Korea and assess the associated factors of PHH. This cohort study used prospectively collected data from the Korean Neonatal Network (KNN). Among 2,386 VLBW infants in the KNN database born between January 2013 and June 2014, 63 infants who died without brain ultrasonography results were excluded. Maternal demographics and neonatal clinical characteristics were assessed. The overall incidence of IVH in all the VLBW infants was 42.2% (987 of 2,323), while those of IVH grade 1, 2, 3, and 4 were 25.1%, 7.0%, 4.8%, and 5.5%, respectively. The incidence and severity of IVH showed a negatively correlating trend with gestational age and birth weight. PHH developed in 0%, 3.5%, 36.1%, and 63.8% of the surviving infants with IVH grades 1, 2, 3, and 4, respectively. Overall, in the VLBW infants, the IVH-associated mortality rate was 1.0% (24/2,323). Only IVH grade severity was proven to be an associated with PHH development in infants with IVH grades 3-4. This is the first Korean national report of IVH and PHH incidences in VLBW infants. Further risk factor analyses or quality improvement studies to reduce IVH are warranted.

  4. Beagle puppy model of intraventricular hemorrhage: effect of indomethacin on cerebral blood flow

    International Nuclear Information System (INIS)

    Ment, L.R.; Stewart, W.B.; Duncan, C.C.; Scott, D.T.; Lambrecht, R.

    1983-01-01

    The newborn beagle puppy has been demonstrated to provide a good model for neonatal intraventricular hemorrhage (IVH). A study was designed to determine if indomethacin can prevent IVH and if indomethacin would produce changes in cerebral blood flow (CBF). Newborn beagle puppies were randomized by computer into two groups: one was pretreated with indomethacin, a known inhibitor of prostaglandin synthetase, and the other was saline. The dogs in both groups were then assigned either to undergo hemorrhagic hypotension/volume reexpansion insult or to receive no insult. Twenty percent of all pups receiving indomethacin and undergoing the insult experienced IVH, compared to 71% of the pups undergoing insult that had been pretreated with saline. Significant alterations in the blood pressure responses to the hemorrhagic hypotension/volume reexpansion insult were noted in the former group compared to the saline-pretreated pups subjected to insult. Finally, employing carbon-14 autoradiography for the determination of CBF, it was demonstrated that indomethacin decreases resting CBF of the newborn beagle pups and, in indomethacin-pretreated animals subjected to insult, prevents the increases in CBF seen in the saline-pretreated traumatized pups. 62 references, 1 figure, 3 tables

  5. A Century of Germinal Matrix Intraventricular Hemorrhage in Autopsied Premature Infants: A Historical Account.

    Science.gov (United States)

    Hefti, Marco M; Trachtenberg, Felicia L; Haynes, Robin L; Hassett, Catherine; Volpe, Joseph J; Kinney, Hannah C

    2016-01-01

    The care of premature infants in the 20th century is remarkable for technical advances that have dramatically improved survival, but little is known about temporal changes in the neuropathology of the premature infant over this time frame. We hypothesize that the autopsy rate of germinal matrix hemorrhage changed in the 20th century relative to combined influences of clinical interventions that were both harmful and helpful. We examined germinal matrix hemorrhage with intraventricular hemorrhage (GMH-IVH) in 345 premature infants (gestational age 25-36 weeks) autopsied at Boston Children's Hospital from 1914 to 2015. There was a median of 19 cases/decade (range 7-68). Over the course of the study median gestational age decreased from 33 to 27 gestational weeks (P3-fold around the time of the introduction of positive pressure ventilation into premature intensive care in the mid-1960s. The increased incidence of GMH-IVH in the 1970s-1980s likely reflects respiratory and hemodynamic imbalances complicating mechanical ventilation. We speculate that the subsequent decreased incidence of GMH-IVH likely reflects stabilization of respiratory function with improvements in ventilators and in ventilator management beginning in the 1970s and the use of surfactant and antenatal steroids in the 1980s.

  6. Ressonância magnética dos cavernomas intraventriculares: aspectos diagnósticos

    Directory of Open Access Journals (Sweden)

    Tatsui Cláudio Esteves

    2003-01-01

    Full Text Available Cavernomas são malformações vasculares que frequentemente acometem a substância branca dos hemisférios cerebrais e tronco encefálico. São angiograficamente ocultas e têm como principal método diagnóstico a ressonância magnética, em que tipicamente se observa nas sequências ponderadas em T2, um halo perilesional hipointenso devido a deposição de hemossiderina no tecido adjacente. A localização ventricular é considerada rara, e suas características de imagem na ressonância magnética diferem, podendo não apresentar tal halo. Apresentamos dois casos nos quais o diagnóstico foi feito somente com exame histopatológico, devido a ausência dos critérios de imagem que permitiriam a suspeita de tal lesão. Os cavernomas devem ser incluidos no diagnóstico diferencial dos processos expansivos intraventriculares, sendo a ressecção cirurgica completa a melhor modalidade de tratamento para estas lesões.

  7. The Effect of Humanin on Spatial Memory Disorder Induced by Intraventricular Injection of Streptozotocin in Rats

    Directory of Open Access Journals (Sweden)

    2014-10-01

    Full Text Available Backgrounds & aim: Sporadic Alzheimer's is known as a new type of devastating disease that the impairment of the insulin signaling pathway may be one of factors causing it. The aim of study was to determine the impact of humanin on spatial memory impairment induced by intraventricular injection of streptozotocin in rats. Methods: In this experimental study 42 male rats weighing 250 to 300 g were selected and then cannule implanted bilaterally into their lateral ventricles. STZ or saline was injected in lateral ventricle every other day for the first and the third days. Humanin drug was injected at doses (0.01, 0.05, 0.1and 1 n/mol from days four until fourteenth. From day 14th to 17th the animal spatial memory was studied using water maze method. Data were analyzed by repeated measure and one-way analysis of variance (ANOVA followed by Tukey's test. Results: Groups treated with humanin at doses 0.01, 0.05, 0.1 and 1 n/mol could not significant improved spatial memory deficits induced by STZ. Conclusion: Humanin with its known neuroprotective effects could not improve spatial memory deficits induced by intra-cerebroventricular STZ.

  8. [Correlation between the use of sodium bicarbonate and intraventricular hemorrhage in preterms].

    Science.gov (United States)

    García-Pasquel, María José; Iglesias-Leboreiro, José; Bernardez-Zapata, Isabel

    2015-01-01

    Being born preterm implies comorbidities, among them the risk of intraventricular hemorrhage (IVH). The use of sodium bicarbonate has been linked to the presence of IVH. The main purpose of this study was to determine if the infusion of sodium bicarbonate during the first 24 hours increases the risk of IVH in preterm infants. Our study is a cohort; we analyzed the files of 160 patients and divided them into two groups: one in which sodium bicarbonate was not used and another in which it was; this latter group was subdivided into two considering if the use was therapeutic of prophylactic. In our total group of patients 10 % presented IVH; had a mean weight of 1500 g and 31 weeks of gestational age. The incidence of IVH was identical between both groups, although patients in which bicarbonate was used were more premature, unstable, and in worse clinical conditions. Our data indicate the need of large scale studies to determine if the clinical benefits of the use of sodium bicarbonate outweigh the risk of IVH.

  9. Role of selected cytokines in the etiopathogenesis of intraventricular hemorrhage in preterm newborns.

    Science.gov (United States)

    Szpecht, Dawid; Wiak, Katarzyna; Braszak, Anna; Szymankiewicz, Marta; Gadzinowski, Janusz

    2016-11-01

    Proinflammatory cytokines are essential mediators and indicators of an inflammatory process occurring in the body. Their physiological role is to stimulate the immune response, yet their excessive propagation and interaction with cells outside the immune system may be linked to the risk of organ damage. This is specifically important in the case of immature tissues of fetuses and prematurely born infants. Analysis of the concentrations of specific cytokines in different compartments makes it possible to assess the risk of premature birth, preterm rupture of the membranes, and to determine an existing intrauterine infection. The purpose of this paper is to summarize the existing research concerning the relationships between the concentrations of specific proinflammatory cytokines in different compartments (maternal blood serum, amniotic fluid, umbilical cord blood, arterial and venous blood, and cerebrospinal fluid of the newborn) and the risk of intraventricular hemorrhage (IVH) and the degree of its severity. The paper takes also into account the assessment of the usefulness of cytokines as biomarkers for IVH and its complications (posthemorrhagic hydrocephalus, white matter injury).

  10. ETIOPATHOGENIC CHARACTERISTICS OF THE INTRAVENTRICULAR HEMORRHAGES IN THE STRUCTURE OF PERINATAL BRAIN INJURIES: A LITERATURE REVIEW AND THE RESULTS OF OWN RESEARCH

    Directory of Open Access Journals (Sweden)

    B. M. Glukhov

    2017-01-01

    Full Text Available Background. The term «intraventricular hemorrhage of the newborn» was first introduced in the Soviet Union in 1970s. In the first soviet guidelines on pediatric neurology, the intraventricular hemorrhage (IVH was considered as a complication after birth injury induced by a mechanical trauma to the fetal head due to the choroidal vascular plexus. The first large-scale studies devoted to IVH in children were conducted in the USA in the 1970s after the introduction of ultrasound examination of brain, which is the main instrumental method for IVH diagnostics. In 1978, the specialists manage to explore the germinal matrix of the brain in the fetus and newborn, which is believed to be the main source of IVH in premature newborns. This structure was shown to give rise to brain neuroblasts and glia: this is a capillary-rich area that consists of poorly differentiated randomly arranged cells, and has a soft connective-tissue carcass that can cause IVH in this area in newborns. According to a currently accepted approach, risk factors for IVH are divided into 3 pathogenetic groups: antenatal, intranatal and postnatal. Among the antenatal risk factors, the main role belongs to the prenatal infection, especially viral infection. Besides, mother comorbidities (first of all cardiovascular and endocrine diseases and pathological pregnancy (threatened abortion, severe gestosis and placental insufficiency are also considered as important predictors of IVH. The internatal risk factors include placental detachment, precipitate labor, disseminated intravascular coagulation syndrome in mother etc. In this article the authors present a detailed review of currently available data as well as the results of own studies.Objective: to provide an overview of the stages of the IVH investigation, to identify the main features of the IVH etiopathogenesis comparing to other perinatal disorders of the central nervous system, and to assess the consequences of IVH.Materials and

  11. Prophylactic administration of porcine-derived lung surfactant is a significant factor in reducing the odds for peri-intraventricular haemorrhage in premature infants.

    Science.gov (United States)

    Walti, Hervé; Paris-Llado, Josefa; Egberts, Johannes; Brand, Roland; Bevilacqua, Giulio; Gardini, Fabrizio; Bréart, Gérard

    2002-01-01

    We hypothesized that prophylactic treatment with a porcine-modified lung surfactant (PLS) reduces the rate of peri-intraventricular haemorrhage (PIVH) more than rescue treatment. We performed a meta-analysis of three prophylactic versus rescue trials conducted with PLS in four countries using individual data. Overall (grades 1-4) or severe (grades 3 and 4) PIVH of 671 newborns was the outcome. A logistic regression analysis was performed. Prophylactic exposure to PLS was a significant independent factor in reducing the incidence of overall (OR 0.65; 95% CI 0.47-0.90) and severe (OR 0.56; 95% CI 0.35-0.89) PIVH. Moreover, for severe PIVH, the adjusted OR for outborn babies exposed to prophylactic treatment with PLS was highly significant (OR 0.11; 95% CI 0.02-to 0.49). The results we obtained show that prophylactic treatment with PLS reduces the rate of PIVH more than rescue treatment. Copyright 2002 S. Karger AG, Basel

  12. Delayed Senescence

    Science.gov (United States)

    2004-01-01

    Researcher Dr. Yi Li developed a technique to manipulate certain characteristics of plant growth such as anit-senescence. For example, the tobacco leaf was clipped from a transgenic plant (right), and a wildtype plant (left). During ground-based laboratory studies, both leaves were left in a darkened area for 4 months. When retrieved, the wildtype plant leaf was dried-out and the transgenic leaf remained fresh and green. A variation of this technology that involves manipulating plant hormones has been conducted in space-based studies on tomato plants through BioServe Space Technologies. The transport and distribution of auxin, an important plant hormone has shown to be influenced by microgravity, which could lead to improving the quality of fruits and vegetables grown on Earth.

  13. Leading causes of preterm delivery as risk factors for intraventricular hemorrhage in very preterm infants: results of the EPIPAGE 2 cohort study.

    Science.gov (United States)

    Chevallier, Marie; Debillon, Thierry; Pierrat, Veronique; Delorme, Pierre; Kayem, Gilles; Durox, Mélanie; Goffinet, François; Marret, Stephane; Ancel, Pierre Yves

    2017-05-01

    Intraventricular hemorrhage is a major risk factor for neurodevelopmental disabilities in preterm infants. However, few studies have investigated how pregnancy complications responsible for preterm delivery are related to intraventricular hemorrhage. We sought to investigate the association between the main causes of preterm delivery and intraventricular hemorrhage in very preterm infants born in France during 2011 between 22-31 weeks of gestation. The study included 3495 preterm infants from the national EPIPAGE 2 cohort study who were admitted to neonatal intensive care units and had at least 1 cranial ultrasound assessment. The primary outcome was grade I-IV intraventricular hemorrhage according to the Papile classification. Multinomial logistic regression models were used to study the relationship between risk of intraventricular hemorrhage and the leading causes of preterm delivery: vascular placental diseases, isolated intrauterine growth retardation, placental abruption, preterm labor, and premature rupture of membranes, with or without associated maternal inflammatory syndrome. The overall frequency of grade IV, III, II, and I intraventricular hemorrhage was 3.8% (95% confidence interval, 3.2-4.5), 3.3% (95% confidence interval, 2.7-3.9), 12.1% (95% confidence interval, 11.0-13.3), and 17.0% (95% confidence interval, 15.7-18.4), respectively. After adjustment for gestational age, antenatal magnesium sulfate therapy, level of care in the maternity unit, antenatal corticosteroids, and chest compressions, infants born after placental abruption had a higher risk of grade IV and III intraventricular hemorrhage compared to those born under placental vascular disease conditions, with adjusted odds ratios of 4.3 (95% confidence interval, 1.1-17.0) and 4.4 (95% confidence interval, 1.1-17.6), respectively. Similarly, preterm labor with concurrent inflammatory syndrome was associated with an increased risk of grade IV intraventricular hemorrhage (adjusted odds ratio

  14. Intraventricular Transplantation of Autologous Bone Marrow Mesenchymal Stem Cells via Ommaya Reservoir in Persistent Vegetative State Patients after Haemorrhagic Stroke: Report of Two Cases & Review of the Literature.

    Science.gov (United States)

    Fauzi, Asra Al; Suroto, Nur Setiawan; Bajamal, Abdul Hafid; Machfoed, Moh Hasan

    2016-01-01

    Background: One of the most devastating diseases, stroke, is a leading cause of death and disability worldwide with severe emotional and economic consequences. The purpose of this article is mainly to report the effect of intraventricular transplantation via an Ommaya reservoir using autologous bone marrow mesenchymal stem cells (BM-MSCs) in haemorrhagic stroke patients. Case Presentations: Two patients, aged 51 and 52, bearing sequels of haemorrhagic stroke were managed by intraventricular transplantation of BM-MSCs obtained from their own bone marrow. Before the procedure, both patients were bedridden, tracheostomised, on nasogastric (NG) tube feeding and in hemiparesis. The cells were transplanted intraventricularly (20 x 10 6 cells/2.5 ml) using an Ommaya reservoir, and then repeated transplantations were done after 1 and 2 months consecutively. The safety and efficacy of the procedures were evaluated 3, 6 and 12 months after treatment. The National Institute of Health Stroke Scale (NIHSS) was used to evaluate the patients' neurological status before and after treatment. No adverse events derived from the procedures or transplants were observed in the one-year follow-up period, and the neurological status of both patients improved after treatment. Conclusions: Our report demonstrates that the intraventricular transplantation of BM-MSCs via an Ommaya reservoir is safe and it improves the neurological status of post-haemorrhagic stroke patients. The repeated transplantation procedure is easier and safer to perform via a subcutaneously implanted Ommaya reservoir. Key Words: Haemorrhagic stroke, bone marrow mesenchymal stem cells (BM-MSCs), intraventricular transplantation.

  15. Therapy of CNS leukemia with intraventricular chemotherapy and low-dose neuraxis radiotherapy

    International Nuclear Information System (INIS)

    Steinherz, P.; Jereb, B.; Galicich, J.

    1985-01-01

    Successful treatment of CNS leukemic relapse has been frustrated by frequent local recurrence and eventual marrow relapse. The authors describe the treatment of meningeal leukemia in 39 children with intrathecal remission induction followed by the placement of an Ommaya reservoir to facilitate the administration and distribution of chemotherapeutic agents into the CSF. Six hundred or 900 rad of craniospinal radiation and maintenance intraventricular and intrathecal chemotherapy was then administered. Systemic reinduction therapy was added in the later cases. Sixteen children (41%) experienced no further events, with 17+ months to 13+ years (median, 25 months) follow-up . Eleven patients (28%) had CNS recurrence, nine (23%) bone marrow (BM) relapse, and two (5%) testicular relapse as the next adverse event. The course of patients with first isolated CNS relapse differed from that of the others. Eleven (69%) of 16 patients treated for first isolated CNS relapse are alive and 9 are event free, while only 35% of patients whose CNS relapse occurred simultaneously or after recurrent disease at other sites are alive (P = .04). Seven of 23 in the later group are event free. The difference is due to the increased incidence of BM relapse in the later group (30% v 6%; P = .04). For patients with first isolated CNS relapse, the life-table median CNS remission duration is 42 months. The projected CNS relapse-free survival and event-free survival 8 to 10 years after CNS relapse are 40% and 32%, respectively. Headache, nausea, and emesis of short duration were frequent during therapy. In three patients, the reservoir had to be removed for infection. No patient suffered neurologic deficit related to the reservoir. The therapy described can reduce the CNS relapse rate with manageable toxicity

  16. [Short, middle and long-term outcome of major peri-intraventricular hemorrhages].

    Science.gov (United States)

    Monset-Couchard, M; de Bethmann, O; Radvanyi, M F; Moriette, G; Papin, C; Relier, J P

    1987-11-01

    Within 4 years 10 months (1981-1985), the Port-Royal Neonatal Intensive Care Unit admitted 2,400 neonates, one third with a birthweight below 1,501 g; 4,631 cranial ultrasound studies were performed in 1,488 of those neonates, mostly less than 1,501 g, detecting 392 consecutive peri-intraventricular hemorrhages (PIVH), of which 130 were major forms (from unilateral grade III to bilateral grade IV PIVH). Overall survival rates were 91% in grade I, 85% in grade II, 42% in grade III, 26% in grade IV; survival rate was significantly lower in bilateral than in unilateral grade II and III PIVH. In major PIVH, deaths occurred early (58% in the first week after birth). Post-hemorrhagic dilatation was constant but mostly regressive; true active hydrocephalus appeared in 1 unilateral grade III PIVH and 8 bilateral grade III PIVH, with ventriculo-peritoneal shunt in the second month of life in 5 infants (2 died), and 4 deaths (surgery not feasible). The neurological and developmental outcome of 42 of 46 survivors (4 losts to follow-up) was evaluated beyond one year of age in 12 unilateral grade III PIVH (10 normal children, 1 minor sequela, 1 moderate sequela), 16 bilateral grade III PIVH (7 normal children, 3 minor sequelae, 1 moderate sequela, 5 major sequelae), 13 unilateral grade IV PIVH (8 normal children, 1 minor sequela, 3 moderate sequelae, 1 major sequela), 1 bilateral grade IV PIVH (major sequela). A persistent major dilatation after 6-9 months of age bore an ominous prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Intraventricular hemorrhage risk factors in very low birth weight newborns: a case-control study

    Directory of Open Access Journals (Sweden)

    Laura Martins

    2009-09-01

    Full Text Available Objective: Identification of variables that affect the risk of severe intraventricular hemorrhage (IVH in very low birth weight (VLBW newborns. Methods: Analytic case-control study, in a population consisting of all VLBW newborns admitted to the Neonatal Intensive Care Unit of a maternity hospital, between January 2002 and December 2007. The authors considered as cases all VLBW newborns with severe IVH (grade ≥ 3, and control all VLBW newborns without IVH. Independent variables included obstetric, perinatal and neonatal diagnosis and therapy. Bivariate analysis and multivariate logistic regression analysis were performed. Rresults: During this period, of the 864 VLBW newborns admitted to the Neonatal Intensive Care Unit, 9.7% had severe IVH. With bivariate analysis an association between severe IVH, gestational age and birth weight was found. Prenatal care and pre-eclampsia were associated with a decrease in the incidence of severe IVH. Amnionitis, being outborn, vaginal delivery, male gender, intubation in the delivery room, surfactant, hyaline membrane disease, pneumothorax, necrotizing enterocolitis (NEC perforation and oscillatory high frequency ventilation were associated with an increased incidence of severe IVH. By multivariate logistic regression, the variables associated with increased risk of severe IVH were: pneumothorax (OR = 3.8; 95%CI = 1.7-8.3, NEC with perforation (OR = 8.8; 95%CI = 1.7-45.0, vaginal delivery (OR = 2.0; 95%CI = 1.0-4.1 and high frequency ventilation (OR = 4.8; 95%CI = 1.3-17.3. The following were protective of severe IVH: gestational age (OR = 0.61; 95%CI = 0.52-0.72, patent ductus arteriosus treatment with indomethacin (OR = 0.26; 95%CI = 0.11-0.6 and fertility treatment (OR = 0.24; 95%CI = 0.06-0.94. Cconclusion: These data outline the importance of improvement of pre and neonatal care to reduce severe IVH.

  18. Hypernatremia and grade III/IV intraventricular hemorrhage among extremely low birth weight infants.

    Science.gov (United States)

    Lim, W-H; Lien, R; Chiang, M-C; Fu, R-H; Lin, J-J; Chu, S-M; Hsu, J-F; Yang, P-H

    2011-03-01

    To identify the risk factors contributing to intraventricular hemorrhage (IVH) in extremely low birth weight infants during early postnatal life, after appropriate matching for gestational age (GA) and birth body weight (BBW). A case-control retrospective study was designed to evaluate preterm infants with a GA ≤ 26 weeks and a BBW ≤ 1000 g admitted to our hospital during a 7.5-year period. From a cohort of 347 preterm infants, 36 infants (10.7%) had severe IVH (grades III and/or IV). We selected a control group of 36 preterm infants without IVH who were closely matched for GA (± 1 week) and body weight (± 100 g). Univariate and multivariate logistic regression analyses were performed to identify risk factors for severe IVH. The GA and BBW of the IVH and control groups were 24.6 ± 1 weeks and 764.4 ± 118.5 g, and 24.8 ± 0.9 weeks and 771.5 ± 125.9 g, respectively. Vaginal delivery, male sex, resuscitation in the delivery room, high sodium serum levels (meq l(-1)) (162.6 vs 148.8), fluctuation of serum sodium (meq l(-1)) (17.3 vs 6.2), pH, PaCO(2), hemoglobin and platelet counts were associated with an increased risk of severe IVH. Multivariate logistic regression indicated that sodium fluctuations >13 meq l(-1), vaginal delivery, male sex and hemoglobin fluctuations are strongly associated with the development of severe IVH. Hypernatremia and fluctuations of sodium seem to be related to early severe IVH among preterm infants; however, further studies are required to clarify the causal relationship.

  19. Clinical features and prognostic factors in patients with intraventricular hemorrhage caused by ruptured arteriovenous malformations

    Science.gov (United States)

    Ye, Zengpanpan; Ai, Xiaolin; Hu, Xin; Fang, Fang; You, Chao

    2017-01-01

    Abstract Intraventricular hemorrhage (IVH) was associated with poor outcomes in patients with intracerebral hemorrhage. IVH had a high incidence in patients with ruptured arteriovenous malformations (AVMs). In this study, we aimed to discuss the clinical features and prognostic factors of outcomes in the patients with AVM-related IVH. From January 2010 to January 2016, we collected the data of the patients with AVM-related IVH retrospectively. The data, including clinical and radiological parameters, were collected to evaluate the clinical features. Univariate and multivariate logistic regression analyses were used to identify the prognostic factors for clinical outcomes (hydrocephalus, 6-month outcomes measured by the modified Rankin scale) in our cohort. A total of 67 eligible patients were included and 19 patients (28%) only presented with IVH. Thirty-three patients (49%) presented hydrocephalus, and 12 patients (18%) presented brain ischemia. Nineteen patients (28%) had a poor outcome after 6 months. In multivariate logistic regression, subarachnoid hemorrhage (SAH) (P = .028) was associated with hydrocephalus and higher Graeb score (P = .080) tended to increase the risk of hydrocephalus. The high Glasgow coma scale (P = .010), large hematoma volume of parenchyma (P = .006), and high supplemented Spetzler–Martin (sup-SM) score (P = .041) were independent factors of the poor outcome. IVH was common in ruptured AVMs and increased the poor outcomes in patients with the ruptured AVMs. The AVM-related IVH patients had a high incidence of hydrocephalus, which was associated with brain ischemia and SAH. Patients with lower Glasgow coma scale, lower sup-SM score, and smaller parenchymal hematoma had better long-term outcomes. PMID:29137064

  20. Intraventricular hemorrhage in the preterm neonate: timing and cerebral blood flow changes

    International Nuclear Information System (INIS)

    Ment, L.R.; Duncan, C.C.; Ehrenkranz, R.A.; Lange, R.C.; Taylor, K.J.; Kleinman, C.S.; Scott, D.T.; Sivo, J.; Gettner, P.

    1984-01-01

    Serial cranial ultrasound studies, 133xenon inhalation cerebral blood flow determinations, and risk factor analyses were performed in 31 preterm neonates. Contrast echocardiographic studies were additionally performed in 16 of these 31 infants. Sixty-one percent were found to have germinal matrix or intraventricular hemorrhage. Seventy-four percent of all hemorrhages were detected by the thirtieth postnatal hour. The patients were divided into three groups: early GMH/IVH by the sixth postnatal hour (eight infants) interval GMH/IVH from 6 hours through 5 days (10), and no GMH/IVH (12). Cerebral blood flow values at 6 postnatal hours were significantly lower for the early GMH/IVH group than for the no GMH/IVH group (P less than 0.01). Progression of GMH/IVH was observed only in those infants with early hemorrhage, and these infants had a significantly higher incidence of neonatal mortality. Ventriculomegaly as determined by ultrasound studies was noted equally in infants with and without GMH/IVH (50%) and was not found to correlate with low cerebral blood flow. The patients with early hemorrhage were distinguishable by their need for more vigorous resuscitation at the time of birth and significantly higher ventilator settings during the first 36 postnatal hours, during which time they also had higher values of PCO2. An equal incidence of patent ductus arteriosus was found across all of the groups. We propose that early GMH/IVH may be related to perinatal events and that the significant decrease in cerebral blood flow found in infants with early GMH/IVH is secondary to the presence of the hemorrhage itself. Progression of early GMH/IVH and new interval GMH/IVH may be related to later neonatal events known to alter cerebral blood flow

  1. 3D ultrasound system to investigate intraventricular hemorrhage in preterm neonates

    International Nuclear Information System (INIS)

    Kishimoto, J; Lawrence, K St; De Ribaupierre, S; Fenster, A; Lee, D S C; Mehta, R

    2013-01-01

    Intraventricular hemorrhage (IVH) is a common disorder among preterm neonates that is routinely diagnosed and monitored by 2D cranial ultrasound (US). The cerebral ventricles of patients with IVH often have a period of ventricular dilation (ventriculomegaly). This initial increase in ventricle size can either spontaneously resolve, which often shows clinically as a period of stabilization in ventricle size and eventual decline back towards a more normal size, or progressive ventricular dilation that does not stabilize and which may require interventional therapy to reduce symptoms relating to increased intracranial pressure. To improve the characterization of ventricle dilation, we developed a 3D US imaging system that can be used with a conventional clinical US scanner to image the ventricular system of preterm neonates at risk of ventriculomegaly. A motorized transducer housing was designed specifically for hand-held use inside an incubator using a transducer commonly used for cranial 2D US scans. This system was validated using geometric phantoms, US/MRI compatible ventricle volume phantoms, and patient images to determine 3D reconstruction accuracy and inter- and intra-observer volume estimation variability. 3D US geometric reconstruction was found to be accurate with an error of 3 for a single observer. Results from ANOVA for three observers segmenting three patients of IVH grade II did not show any significant differences (p > 0.05) for the measured ventricle volumes between observers. This 3D US system can reliably produce 3D US images of the neonatal ventricular system. There is the potential to use this system to monitor the progression of ventriculomegaly over time in patients with IVH. (paper)

  2. Porcine pilot study of MRI-guided HIFU treatment for neonatal intraventricular hemorrhage (IVH)

    Science.gov (United States)

    Looi, Thomas; Waspe, Adam; Mougenot, Charles; Amaral, Joao; Temple, Michael; Hynynen, Kullervo; Drake, James

    2012-11-01

    Intraventricular hemorrhage (IVH) occurs in 15% of premature babies and 50% of IVH cases progress to posthemorrhagic ventricular dilation due to large blood clots forming in the ventricles. Existing treatments such as tissue plasminogen activator (tPA) and surgical intervention have severe side effects in paediatric patients that include excessive bleeding and complications. This study investigates the feasibility of MR-HIFU for sonothrombolysis of blood clots from IVH using natural acoustic windows, known as fontanelles, in the skulls of newborns. The study involved 2 elements: a phantom study to examine beam limitations and acoustic properties, and an in-vivo porcine study. A phantom skull was created from sample patient data and was used to analyze reachability of the Philips Sonavelle system. Acoustic measurements of the phantom (attenuation of 5-14 dB and speed of sound of 1722-2965 m/s) indicated the phantom effectively mimics neonatal skull bone. For the ex-vivo studies, a porcine clot was created and sonicated for 5 mins at 500W with a 0.5% duty cycle. For the in-vivo experiment, a vertex craniotomy was performed and porcine blood was injected into the lateral ventricle under ultrasound guidance. Sonication using the prior parameters induced cavitation and post-sonication T1 and T2 images verified clot lysis. Further H&E analysis showed no presence of blood in the ventricles. These positive results show that MR-HIFU has potential as a noninvasive tool for sonothrombolysis of neonatal IVH clots.

  3. Simvastatin Promotes Hematoma Absorption and Reduces Hydrocephalus Following Intraventricular Hemorrhage in Part by Upregulating CD36.

    Science.gov (United States)

    Chen, Qianwei; Shi, Xia; Tan, Qiang; Feng, Zhou; Wang, Yuelong; Yuan, Qiaoying; Tao, Yihao; Zhang, Jianbo; Tan, Liang; Zhu, Gang; Feng, Hua; Chen, Zhi

    2017-08-01

    We previously found that hematoma worsens hydrocephalus after intraventricular hemorrhage (IVH) via increasing iron deposition and aggravating ependymal cilia injury; therefore, promoting hematoma absorption may be a promising strategy for IVH. Recently, some investigations imply that simvastatin has the ability of accelerating hematoma absorption. Thus, this study was designed to examine the efficacy of simvastatin for IVH in rats. Intracerebral hemorrhage with ventricular extension was induced in adult male Sprague-Dawley rats after autologous blood injection. Simvastatin or vehicle was administered orally at 1 day after IVH and then daily for 1 week. MRI studies were performed to measure the volumes of intracranial hematoma and lateral ventricle at days 1, 3, 7, 14, and 28 after IVH. Motor and neurocognitive functions were assessed at days 1 to 7 and 23 to 28, respectively. Iron deposition, iron-related protein expression, ependymal damage, and histology were detected at day 28. Expression of CD36 scavenger receptor (facilitating phagocytosis) was examined at day 3 after IVH using western blotting and immunofluorescence. Simvastatin significantly increased hematoma absorption ratio, reduced ventricular volume, and attenuated neurological dysfunction post-IVH. In addition, less iron accumulation and more cilia survival was observed in the simvastatin group when compared with the control. What's more, higher expression of CD36 was detected around the hematoma after simvastatin administration. Simvastatin significantly enhanced brain hematoma absorption, alleviated hydrocephalus, and improved neurological recovery after experimental IVH, which may in part by upregulating CD36 expression. Our data suggest that early simvastatin use may be a novel therapy for IVH patients.

  4. Use of prenatal phenobarbital in the prevention of subependymal/intraventricular hemorrhage in premature infants.

    Science.gov (United States)

    Arroyo-Cabrales, L M; Garza-Morales, S; Hernández-Peláez, G

    1998-01-01

    Subependymal/intraventricular hemorrhage (SE/IVH) is a frequent cause of disability and mortality. This is a prospective, randomized, double-blind study which included 100 pregnant Mexican women who need to interrupt their pregnancy within 28-32 weeks of gestation. One group was given a single dose of intravenous (IV) phenobarbital 10 micrograms/kg (phenobarbital group, n = 50), and the other was provided with diluted distilled water (control group). Measurements of phenobarbital serum concentrations were taken by both mother and newborn, and head sonograms were applied during the first 24 hours, at the 3rd and 7th days of life. The sample was made up of 42 newborns in the phenobarbital group, and 46 in the control group; the newborns had phenobarbital levels of 11.5 5.7 g/microliter at birth, and of 9.5 +/- 5.9 g/microliter 24 hours later. SE/IVH was found in 12 patients from the phenobarbital group and in 29 from the control group (p < 0.005), the first group were 11 mild SE/IVH (2 grade I, and 9 grade II), and 26 in the control group (4 grade I, and 22 grade II), p < 0.005. Severe hemorrhages were similar between groups. A larger frequency of SE/IVH was found in the newborn group which received mechanical ventilation (p = 0.0008). Prenatal phenobarbital can reduce the SE/IVH frequency in premature infants younger than 32 weeks at birth. Its main effect could be shown in patients with mechanical ventilation.

  5. Long-term animal experiments with an intraventricular axial flow blood pump.

    Science.gov (United States)

    Yamazaki, K; Kormos, R L; Litwak, P; Tagusari, O; Mori, T; Antaki, J F; Kameneva, M; Watach, M; Gordon, L; Mukuo, H; Umezu, M; Tomioka, J; Outa, E; Griffith, B P; Koyanagai, H

    1997-01-01

    A miniature intraventricular axial flow blood pump (IVAP) is undergoing in vivo evaluation in calves. The IVAP system consists of a miniature (phi 13.9 mm) axial flow pump that resides within the left ventricular (LV) chamber and a brushless DC motor. The pump is fabricated from titanium alloy, and the pump weight is 170 g. It produces a flow rate of over 5 L/min against 100 mmHg pressure at 9,000 rpm with an 8 W total power consumption. The maximum total efficiency exceeds 17%. A purged lip seal system is used in prototype no. 8, and a newly developed "Cool-Seal" (a low temperature mechanical seal) is used in prototype no. 9. In the Cool-Seal system, a large amount of purge flow is introduced behind the seal faces to augment convective heat transfer, keeping the seal face temperature at a low level for prevention of heat denaturation of blood proteins. The Cool-Seal system consumes < 10 cc purge fluid per day and has greatly extended seal life. The pumps were implanted in three calves (26, 30, and 168 days of support). The pump was inserted through a left thoracotomy at the fifth intercostal space. Two pursestring sutures were placed on the LV apex, and the apex was cored with a myocardial punch. The pump was inserted into the LV with the outlet cannula smoothly passing through the aortic valve without any difficulty. Only 5 min elapsed between the time of chest opening and initiation of pumping. Pump function remained stable throughout in all experiments. No cardiac arrhythmias were detected, even at treadmill exercise tests. The plasma free hemoglobin level remained in the acceptable range. Post mortem examination did not reveal any interference between the pump and the mitral apparatus. No major thromboembolism was detected in the vital organs in Cases 1 or 2, but a few small renal infarcts were detected in Case 3.

  6. Intrathecal or intraventricular therapy for post-neurosurgical Gram-negative meningitis: matched cohort study.

    Science.gov (United States)

    Shofty, B; Neuberger, A; Naffaa, M E; Binawi, T; Babitch, T; Rappaport, Z H; Zaaroor, M; Sviri, G; Paul, M

    2016-01-01

    Gram-negative post-operative meningitis due to carbapenem-resistant bacteria (CR-GNPOM) is a dire complication of neurosurgical procedures. We performed a nested propensity-matched historical cohort study aimed at examining the possible benefit of intrathecal or intraventricular (IT/IV) antibiotic treatment for CR-GNPOM. We included consecutive adults with GNPOM in two centres between 2005 and 2014. Patients receiving combined systemic and IT/IV treatment were matched to patients receiving systemic treatment only. Matching was done based on the propensity of the patients to receive IT/IV treatment. We compared patient groups with 30-day mortality defined as the primary outcome. The cohort included 95 patients with GNPOM. Of them, 37 received IT/IV therapy in addition to systemic treatment (22 with colistin and 15 with amikacin), mostly as initial therapy, through indwelling cerebrospinal fluid drains. Variables associated with IT/IV therapy in the propensity score included no previous neurosurgery, time from admission to meningitis, presence of a urinary catheter and GNPOM caused by carbapenem-resistant Gram-negative bacteria. Following propensity matching, 23 patients given IT/IV therapy and 27 controls were analysed. Mortality was significantly lower with IT/IV therapy: 2/23 (8.7%) versus 9/27 (33.3%), propensity-adjusted OR 0.19, 95% CI 0.04-0.99. Death or neurological deterioration at 30 days, 14-day and in-hospital mortality were lower with IT/IV therapy (OR <0.4 for all) without statistically significant differences. Among patients discharged alive, those receiving IT/IV therapy did not experience more neurological deterioration. Serious adverse events with IT/IV therapy were not documented. Our results support the early use of IT antibiotic treatment for CR-GNPOM when a delivery method is available. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  7. Two-dimensional intraventricular flow mapping by digital processing conventional color-Doppler echocardiography images.

    Science.gov (United States)

    Garcia, Damien; Del Alamo, Juan C; Tanne, David; Yotti, Raquel; Cortina, Cristina; Bertrand, Eric; Antoranz, José Carlos; Perez-David, Esther; Rieu, Régis; Fernandez-Aviles, Francisco; Bermejo, Javier

    2010-10-01

    Doppler echocardiography remains the most extended clinical modality for the evaluation of left ventricular (LV) function. Current Doppler ultrasound methods, however, are limited to the representation of a single flow velocity component. We thus developed a novel technique to construct 2D time-resolved (2D+t) LV velocity fields from conventional transthoracic clinical acquisitions. Combining color-Doppler velocities with LV wall positions, the cross-beam blood velocities were calculated using the continuity equation under a planar flow assumption. To validate the algorithm, 2D Doppler flow mapping and laser particle image velocimetry (PIV) measurements were carried out in an atrio-ventricular duplicator. Phase-contrast magnetic resonance (MR) acquisitions were used to measure in vivo the error due to the 2D flow assumption and to potential scan-plane misalignment. Finally, the applicability of the Doppler technique was tested in the clinical setting. In vitro experiments demonstrated that the new method yields an accurate quantitative description of the main vortex that forms during the cardiac cycle (mean error for vortex radius, position and circulation). MR image analysis evidenced that the error due to the planar flow assumption is close to 15% and does not preclude the characterization of major vortex properties neither in the normal nor in the dilated LV. These results are yet to be confirmed by a head-to-head clinical validation study. Clinical Doppler studies showed that the method is readily applicable and that a single large anterograde vortex develops in the healthy ventricle while supplementary retrograde swirling structures may appear in the diseased heart. The proposed echocardiographic method based on the continuity equation is fast, clinically-compliant and does not require complex training. This technique will potentially enable investigators to study of additional quantitative aspects of intraventricular flow dynamics in the clinical setting by

  8. Intraventricular hemorrhage in a very low birth weight infants: Associated risk factors in Isfahan, Iran

    International Nuclear Information System (INIS)

    Badiee, Z.

    2007-01-01

    Prematurely born infants with intraventricular hemorrhage (IVH) suffer significant morbidity and mortality, particularly with those infants with high-grade hemorrhage. Previous studies have proposed a number of risk factors for IVH; however, lack of adequate matching for gestational age and birth weight may have confounded the results. The purpose of this study was to identify variables that affect the risk of IVH. We identified 31 preterm infants with gestational age < 32 weeks and birth weight < 1500 g, with IVH, from November 2003 to January 2005 at Alzahra University Hospital, Isfahan, Iran. A control group of 90 infants, matched for gestational age and birth weight was selected. Maternal factors, labor and delivery characteristics and neonatal parameters were collected in both groups. Results of cranial ultrasound examinations were also collected. The significant risk factors for IVH were found to be: patent ductus artreiosus arteriosus (PDA) [4 (13.3%) versus 3(3.3%) (p=0.01)], longer duration of assisted ventilation [4 (2.8+-5.8 days versus 0.5+-2.1 days (p=0.002)], a higher number of endotracheal suctioning [9.7+-18.4 versus 3.06+-13.7 (p=0.004)], surfactant use, [7(22.6%) versus 3(3.4%) (p=0.003)], positive pressure ventilation at birth [12 (38.7%) versus 12(13.3%), (p=0.004)] and low Apgar score at 1 and 5 minutes. Whereas antenatal steroid treatments and cesarean sections have protective effect on the occurrence of IVH. Our data emphasize the importance of obstetric and prenatal care to improve outcomes of premature infants. (author)

  9. Echocardiographic estimation of acute haemodynamic response during optimization of multisite pace-maker using different pacing modalities and atrioventricular delays

    Directory of Open Access Journals (Sweden)

    Šalinger-Martinović Sonja

    2009-01-01

    Full Text Available Background/Aim. Cardiac resynchronization therapy (CRT improves ventricular dyssynchrony and is associated with an improvement in symptoms, quality of life and prognosis in patients with severe heart failure and intraventricular conduction delay. Different pacing modalities produce variable activation patterns and may be a cause of different haemodynamic changes. The aim of our study was to investigate acute haemodynamic changes with different CRT configurations during optimization procedure. Methods. This study included 30 patients with severe left ventricular systolic dysfunction and left bundle branch block with wide QRS (EF 24.33 ± 3.7%, QRS 159 ± 17.3 ms, New York Heart Association III/IV 25/5 with implanted CRT device. The whole group of patients had severe mitral regurgitation in order to measure dP/dt. After implantation and before discharge all the patients underwent optimization procedure guided by Doppler echocardiography. Left and right ventricular pre-ejection intervals (LVPEI and RVPEI, interventricular mechanical delay (IVD and the maximal rate of ventricular pressure rise during early systole (max dP/dt were measured during left and biventricular pacing with three different atrioventricular (AV delays. Results. After CRT device optimization, optimal AV delay and CRT mode were defined. Left ventricular pre-ejection intervals changed from 170.5 ± 24.6 to 145.9 ± 9.5 (p < 0.001, RVPEI from 102.4 ± 15.9 to 119.8 ± 10.9 (p < 0.001, IVD from 68.1 ± 18.3 to 26.5 ± 8.2 (p < 0.001 and dP/dt from 524.2 ± 67 to 678.2 ± 88.5 (p < 0.01. Conclusion. In patients receiving CRT echocardiographic assessment of the acute haemodynamic response to CRT is a useful tool in optimization procedure. The variability of Doppler parameters with different CRT modalities emphasizes the necessity of individualized approach in optimization procedure.

  10. Increased intraventricular pressures are as harmful as the electrophysiological substrate of heart failure in favoring sustained reentry in the swine heart.

    Science.gov (United States)

    Quintanilla, Jorge G; Moreno, Javier; Archondo, Tamara; Usandizaga, Elena; Molina-Morúa, Roberto; Rodríguez-Bobada, Cruz; González, Pablo; García-Torrent, María Jesús; Filgueiras-Rama, David; Pérez-Castellano, Nicasio; Macaya, Carlos; Pérez-Villacastín, Julián

    2015-10-01

    Heart failure (HF) electrophysiological remodeling (HF-ER) often includes the effect of chronically increased intraventricular pressures (IVPs) and promotes ventricular tachycardia/ventricular fibrillation (VT/VF). In addition, acutely increased IVPs have been associated with a higher rate of VT/VF episodes in chronic HF. We hypothesized that increased IVPs and/or an ionic-imbalanced (acidified), catecholamine-rich (adrenergic) milieu (AA milieu) may contribute as much as HF-ER to the substrate for reentry in HF. We used a porcine model of tachycardiomyopathy and evaluated the individual/combined contributions of (1) increased IVPs, (2) HF-ER, and (3) an AA milieu. HF-ER was induced in 7 pigs by rapid pacing. Seven pigs were used as controls. Hearts were isolated and Langendorff perfused. Programmed ventricular stimulation was conducted under low or increased IVP and normal/AA milieu (4 combinations). Epicardial optical mapping was used to quantify conduction velocity (CV), action potential duration (APD), and dispersion of repolarization (DoR). HF-ER decreased CV (-34%; P = .002) and increased APD (11%; P = .024) and DoR (21%; P = .007). Increased IVP amplified DoR (36%; P 6-fold). By magnifying DoR, decreasing CV, and shortening APD, increased IVP was as harmful as HF-ER in favoring the substrate for sustained reentry in this model. The AA milieu contributed to a much lesser extent. Thus, a stricter control of IVP might be postulated as a useful add-on antiarrhythmic strategy in HF. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  11. [Impact of screening and treatment of low systemic blood flow in the prevention of severe intraventricular haemorrhage and/or death in pre-term infants].

    Science.gov (United States)

    Oulego Erroz, Ignacio; Alonso Quintela, Paula; Jiménez Gonzalez, Aquilina; Terroba Seara, Sandra; Rodríguez Blanco, Silvia; Rosón Varas, María; Castañón López, Leticia

    2018-04-02

    To assess the effect of a protocolised intervention for low systemic blood flow (SBF) in the occurrence of severe intraventricular haemorrhage (IVH) or death in pre-term infants. A study with a quasi-experimental design with retrospective controls was conducted on pre-term infants of less than 30weeks of gestational age, born between January 2016 and July 2017, who were consecutively included in the intervention period. The control cohort included pre-term infants (born between January 2013 and December 2015) matched by gestational age, birth weight, and gender (two controls for each case). The cases of low SBF diagnosed according to functional echocardiography during the study period received dobutamine (5-10μg/kg/min) for 48hours. The study included 29 cases (intervention period) and 54 controls (pre-intervention period). Ten out of 29 (34.5%) infants received dobutamine for low SBF during the intervention period, with 3/29 (10.3%) cases of severe IVH and/or death compared to 17/54 (31.5%) in the control cohort (p=.032). There was an independent association between the intervention and a decreased occurrence of severe IVH/death after adjusting for confounding factors both in the logistic regression model [OR 0.11 (95%CI: 0.01-0.65), p=.015], as well as in the sensitivity analysis using inverse probability of treatment weighting [OR 0.23 (95%CI: 0.09-0.56); p=.001]. In this study with retrospective controls, a protocolised screening, and treatment for low SBF was associated with a decreased occurrence of severe IVH or death in preterm infants. Large, adequately powered trials, are needed in order to determine whether postnatal interventions directed at low SBF can improve neurological outcomes. Copyright © 2018. Publicado por Elsevier España, S.L.U.

  12. The Effect of Head Positioning and Head Tilting on the Incidence of Intraventricular Hemorrhage in Very Preterm Infants : A Systematic Review

    NARCIS (Netherlands)

    de Bijl-Marcus, Karen A; Brouwer, Annemieke J|info:eu-repo/dai/nl/334070805; de Vries, Linda S|info:eu-repo/dai/nl/072995408; van Wezel-Meijler, Gerda

    2017-01-01

    BACKGROUND: Despite advances in neonatal intensive care, germinal matrix-intraventricular hemorrhage (GMH-IVH) remains a frequent, serious complication of premature birth. Neutral head position and head tilting have been suggested to reduce the risk of GMH-IVH in preterm infants during the first 72

  13. Intraventricular Transplantation of Autologous Bone Marrow Mesenchymal Stem Cells via Ommaya Reservoir in Persistent Vegetative State Patients after Haemorrhagic Stroke: Report of Two Cases & Review of the Literature

    Directory of Open Access Journals (Sweden)

    Fauzi AA

    2016-11-01

    Full Text Available Background: One of the most devastating diseases, stroke, is a leading cause of death and disability worldwide with severe emotional and economic consequences. The purpose of this article is mainly to report the effect of intraventricular transplantation via an Ommaya reservoir using autologous bone marrow mesenchymal stem cells (BM-MSCs in haemorrhagic stroke patients. Case Presentations: Two patients, aged 51 and 52, bearing sequels of haemorrhagic stroke were managed by intraventricular transplantation of BM-MSCs obtained from their own bone marrow. Before the procedure, both patients were bedridden, tracheostomised, on nasogastric (NG tube feeding and in hemiparesis. The cells were transplanted intraventricularly (20 x 106 cells/2.5 ml using an Ommaya reservoir, and then repeated transplantations were done after 1 and 2 months consecutively. The safety and efficacy of the procedures were evaluated 3, 6 and 12 months after treatment. The National Institute of Health Stroke Scale (NIHSS was used to evaluate the patients' neurological status before and after treatment. No adverse events derived from the procedures or transplants were observed in the one-year follow-up period, and the neurological status of both patients improved after treatment. Conclusions: Our report demonstrates that the intraventricular transplantation of BM-MSCs via an Ommaya reservoir is safe and it improves the neurological status of post-haemorrhagic stroke patients. The repeated transplantation procedure is easier and safer to perform via a subcutaneously implanted Ommaya reservoir.

  14. Patient delays and system delays in breast cancer treatment in developed and developing countries

    Directory of Open Access Journals (Sweden)

    Angela Gabrielly Quirino Freitas

    2015-10-01

    Full Text Available AbstractDelays in treating breast cancer have been associated with a more advanced stage of the disease and a decrease in patient survival rates. The scope of this integrative review was to analyze the main causal factors and types of patient and system delays. The underlying causal factors of delays were compared among studies conducted in developing and developed countries. Of the 53 studies selected, 24 were carried out in developing countries and 29 in developed countries, respectively. Non-attribution of symptoms to cancer, fear of the disease and treatment and low educational level were the most frequent causes of patient delay. Less comprehensive health insurance coverage, older/younger age and false negative diagnosis tests were the three most common causal factors of system delay. The effects of factors such as age were not decisive per se and depended mainly on the social and cultural context. Some factors caused both patient delay and system delay. Studies conducted in developing countries identified more causal factors of patient delay and had a stronger focus on patient delay or the combination of both. Studies conducted in developed countries had a stronger focus on aspects of system delay during treatment and guidance of breast cancer patients in the health care system.

  15. Neurological evaluation of neonates with intraventricular and periventricular hemorrhage Avaliação neurológica de recém-nascidos com hemorragia intraventricular e periventricular

    Directory of Open Access Journals (Sweden)

    MONICA SANCHEZ-STOPIGLIA

    1999-06-01

    Full Text Available We studied the clinical aspects of 100 consecutive premature newborns with and without intraventricular and periventricular hemorrhage (IPVH.The diagnosis of IPVH was obtained by ultrasonic scans of the skull during the first week of life and at the age of one month. Forty eight percent of newborns with IPVH had abnormal results, and there was a significant correlation with the neurological evaluation in 85% of the infants. The probability of normality for a child with no associated brain abnormalities was 72%, whereas for a child of the same gestational age with associated brain abnormalities was 48.7%.Foram estudados os aspectos clínicos de 100 recém-nascidos prematuros, com e sem hemorragia periventricular-intraventricular (HPIV. O diagnóstico foi obtido através de exames ultra-sonográficos de crânio, realizados durante a primeira semana de vida e na idade corrigida de um mês.Quarenta e oito por cento dos recém-nascidos com HPVI evidenciaram resultados anormais, sendo a correlação significativa com a evolução neurológica, em 85% das crianças. Crianças que não apresentaram anormalidades cerebrais associadas tiveram 72% de probabilidade de manter a evolução normal, enquanto para crianças da mesma idade gestacional porém com anormalidades cerebrais associadas, a probabilidade foi 48,7%.

  16. Hysteresis in conducting ferromagnets

    International Nuclear Information System (INIS)

    Schneider, Carl S.; Winchell, Stephen D.

    2006-01-01

    Maxwell's magnetic diffusion equation is solved for conducting ferromagnetic cylinders to predict a magnetic wave velocity, a time delay for flux penetration and an eddy current field, one of five fields in the linear unified field model of hysteresis. Measured Faraday voltages for a thin steel toroid are shown to be proportional to magnetic field step amplitude and decrease exponentially in time due to maximum rather than average permeability. Dynamic permeabilities are a field convolution of quasistatic permeability and the delay function from which we derive and observe square root dependence of coercivity on rate of field change

  17. Delivery mode and intraventricular hemorrhage risk in very-low-birth-weight infants: Observational data of the German Neonatal Network.

    Science.gov (United States)

    Humberg, Alexander; Härtel, Christoph; Paul, Pia; Hanke, Kathrin; Bossung, Verena; Hartz, Annika; Fasel, Laura; Rausch, Tanja K; Rody, Achim; Herting, Egbert; Göpel, Wolfgang

    2017-05-01

    Very-low-birth-weight infants (VLBWI) are frequently delivered by cesarean section (CS). However, it is unclear at what gestational age the benefits of spontaneous delivery outweigh the perinatal risks, i.e. intraventricular hemorrhage (IVH) or death. To assess the short-term outcome of VLBWI on IVH according to mode of delivery in a population-based cohort of the German Neonatal Network (GNN). A total cohort of 2203 singleton VLBWI with a birth weight 30 weeks of gestation prevalence for IVH was not significantly different in VD and planned CS (5.3% vs. 4.4%). Our observational data demonstrate that elective cesarean section is associated with a reduced risk of IVH in preterm infants <30 weeks gestational age when presenting with preterm labor. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Intraventricular administration of substance p increases the dendritic arborisation and the synaptic surfaces of Purkinje cells in rat's cerebellum.

    Science.gov (United States)

    Baloyannis, S J; Costa, V; Deretzi, G; Michmizos, D

    2000-01-01

    Substance P was infused in the lateral ventricles of twenty Lewis rats for twenty days. On the twentieth day the animals were sacrificed and the cerebellar cortex was processed for electron microscopy. The ultrastructural morphometric analysis revealed that the Purkinje cell dendritic arborisation and the number of the synapses between the parallel fibres and the Purkinje cell dendritic spines were much higher than in control animals. Numerous unattached spines of the secondary and tertiary dendritic branches of the Purkinje cells were also seen in the molecular layer either free or surrounded by astrocytic sheath. The increased number of synapses between the Purkinje cell dendrites and the parallel fibres in the animals, which received substance P intraventricularly, in correlation to control animals, supports a neurotrophine-like activity of the substance P in the mammalian cerebellum, enforcing the pre-programmed capability of the Purkinje cells to develop new synaptic surfaces.

  19. A case of pneumothorax following bougie-guided intubation in a patient undergoing excision of an intraventricular space occupying lesion

    Directory of Open Access Journals (Sweden)

    Ramanan Rajagopal

    2017-01-01

    Full Text Available A 46-year-old female with intraventricular space occupying lesion was posted for craniotomy and excision of the same. Immediately following routine induction of general anaesthesia and a bougie-guided intubation, she developed increased airway pressures and desaturation associated with a decreased air entry on the right side of the chest suggestive of a right-sided pneumothorax which was confirmed with radio imaging and following the placement of chest drain the saturation improved and airway pressures decreased. To be faced with a pneumothorax following an intubation could be surprising for a non-suspecting anaesthesiologist and it can have important implications especially in neurosurgical cases where a tight control of intracranial pressure is warranted. Hence, this case report emphasises the need for a high index of clinical suspicion for proper management and safe patient outcome.

  20. Positron emission tomography in the newborn: extensive impairment of regional cerebral blood flow with intraventricular hemorrhage and hemorrhagic intracerebral involvement

    International Nuclear Information System (INIS)

    Volpe, J.J.; Herscovitch, P.; Perlman, J.M.; Raichle, M.E.

    1983-01-01

    Positron emission tomography (PET) now provides the capability of measuring regional cerebral blood flow with high resolution and little risk. In this study, we utilized PET in six premature infants (920 to 1,200 g) with major intraventricular hemorrhage and hemorrhagic intracerebral involvement to measure regional cerebral blood flow during the acute period (5 to 17 days of age). Cerebral blood flow was determined after intravenous injection of H 2 O, labeled with the positron-emitting isotope, 15 O. Findings were similar and dramatic in all six infants. In the area of hemorrhagic intracerebral involvement, little or no cerebral blood flow was detected. However, in addition, surprisingly, a marked two- to fourfold reduction in cerebral blood flow was observed throughout the affected hemisphere, well posterior and lateral to the intracerebral hematoma, including cerebral white matter and, to a lesser extent, frontal, temporal, and parietal cortex. In the one infant studied a second time, ie, at 3 months of age, the extent and severity of the decreased cerebral blood flows in the affected hemisphere were similar to those observed on the study during the neonatal period. At the three autopsies, the affected left hemisphere showed extensive infarction, corroborating the PET scans. These observations, the first demonstration of the use of PET in the determination of regional cerebral blood flow in the newborn, show marked impairments in regional cerebral blood flow in the hemisphere containing an apparently restricted intracerebral hematoma, indicating that the hemorrhagic intracerebral involvement is only a component of a much larger lesion, ischemic in basic nature, ie, an infarction. This large ischemic lesion explains the poor neurologic outcome in infants with intraventricular hemorrhage and hemorrhagic intracerebral involvement

  1. Pivotal Role of Brain-Derived Neurotrophic Factor Secreted by Mesenchymal Stem Cells in Severe Intraventricular Hemorrhage in Newborn Rats.

    Science.gov (United States)

    Ahn, So Yoon; Chang, Yun Sil; Sung, Dong Kyung; Sung, Se In; Ahn, Jee-Yin; Park, Won Soon

    2017-01-24

    Mesenchymal stem cell (MSC) transplantation protects against neonatal severe intraventricular hemorrhage (IVH)-induced brain injury by a paracrine rather than regenerative mechanism; however, the paracrine factors involved and their roles have not yet been delineated. This study aimed to identify the paracrine mediator(s) and to determine their role in mediating the therapeutic effects of MSCs in severe IVH. We first identified significant upregulation of brain-derived neurotrophic factor (BDNF) in MSCs compared with fibroblasts, in both DNA and antibody microarrays, after thrombin exposure. We then knocked down BDNF in MSCs by transfection with small interfering (si)RNA specific for human BDNF. The therapeutic effects of MSCs with or without BDNF knockdown were evaluated in vitro in rat neuronal cells challenged with thrombin, and in vivo in newborn Sprague-Dawley rats by injecting 200 μl of blood on postnatal day 4 (P4), and transplanting MSCs (1 × 105 cells) intraventricularly on P6. siRNA-induced BDNF knockdown abolished the in vitro benefits of MSCs on thrombin-induced neuronal cell death. BDNF knockdown also abolished the in vivo protective effects against severe IVH-induced brain injuries such as the attenuation of posthemorrhagic hydrocephalus, impaired behavioral test performance, increased astrogliosis, increased number of TUNEL cells, ED-1+ cells, and inflammatory cytokines, and reduced myelin basic protein expression. Our data indicate that BDNF secreted by transplanted MSCs is one of the critical paracrine factors that play a seminal role in attenuating severe IVH-induced brain injuries in newborn rats.

  2. Delayed Umbilical Cord Clamping in the 21st Century: Indications for Practice.

    Science.gov (United States)

    Bayer, Kimberly

    2016-02-01

    Health care providers have debated the timing of umbilical cord clamping since the days of Aristotle. Delayed cord clamping was the mainstay of practice until about the 1950s when it was changed to immediate clamping on the basis of a series of blood volume studies combined with the introduction of active management of the third stage of labor. However, in recent years, several systematic reviews advise that delayed cord clamping should be used in all births for at least 30 to 60 seconds. The purpose of this article is to discuss the physiology of umbilical cord clamping, the potential benefits and adverse effects of delayed cord clamping, and how this affects the advanced practice nurse. A search of PubMed, Cochrane Reviews, and Clinical Key was used to find relevant research on the topic of umbilical cord clamping. Potential benefits of delayed cord clamping include decreased frequency of iron-deficiency anemia in the first year of life with improved neurodevelopmental outcomes in term infants, reduced need for blood transfusions, possible autologous transfusion of stem cells, and a decreased incidence of intraventricular hemorrhage. Apprehension exists regarding the feasibility of the practice as well as the potential hindrance of immediate resuscitation. There is a need to begin to look for populations for which delayed cord clamping can be implemented. Recommendations are inconsistent on the patient population and timing; therefore, further studies are needed to understand the multiple variables that affect timing of umbilical cord clamping.

  3. Prediction of delayed neurological deficit after subarachnoid haemorrhage: a CT blood load and Doppler velocity approach

    International Nuclear Information System (INIS)

    Grosset, D.G.; McDonald, I.; Cockburn, M.; Straiton, J.; Bullock, R.R.

    1994-01-01

    The predictive value of cranial computed tomography (CT) blood load and serial transcranial Doppler sonography for the development of delayed ischaemic neurological deficit was assessed in 121 patients following subarachnoid haemorrhage. Of the 121 patients, 81 (67 %) had thick layers of blood or haematoma, including intraventricular bleeding. The proportion of patients who developed delayed deficit was higher with increasing amounts of subarachnoid blood on the admission CT (51 % of 53 cases in Fisher grade 3; 35 % of 33 cases in grade 2; 28 % of 7 cases in grade 1, P < 0.01). Doppler velocities obtained from readings at least every 2 days following admission were higher in patients with delayed neurological deficit (peak velocity for grade 3 patients 176 ± 6 cm/s (mean ± SE), versus grade 2: 164 ± 7 cm/s; grade 4 149 ± 9, both P = 0.04, Mann-Whitney). Peak velocity and maximal 24-h rise tended to be higher within different CT grades in patients with a deficit than in those without; this difference was significant for grade 3 patients (P < 0.01). We conclude that a combined approach with CT and Doppler sonography provides greater predictive value for the development of delayed ischaemic neurological deficit than either test considered independently. The value of Doppler sonography may be greatest for patients with Fisher grade 3 blood, in whom the risk of delayed ischaemia is greatest. (orig.)

  4. Effect of Delay on Children's Delay-Execute Prospective Memory Performance

    Science.gov (United States)

    Rendell, Peter G.; Vella, Melissa J.; Kliegel, Matthias; Terrett, Gill

    2009-01-01

    To date, little work has been done investigating prospective memory in children, particularly using a delay-execute paradigm. Two experiments were conducted to investigate this issue with children aged 5-11 years. While playing a computer driving game, children's ability to carry out a delayed intention either immediately a target cue appeared or…

  5. Digital time delay

    Science.gov (United States)

    Martin, A.D.

    1986-05-09

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits latch the high resolution data to form a first synchronizing data set. A selected time interval has been preset to internal counters and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses count down the counters to generate an internal pulse delayed by an internal which is functionally related to the preset time interval. A second LCD corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD to generate a second set of synchronizing data which is complementary with the first set of synchronizing data for presentation to logic circuits. The logic circuits further delay the internal output signal with the internal pulses. The final delayed output signal thereafter enables the output pulse generator to produce the desired output pulse at the preset time delay interval following input of the trigger pulse.

  6. Delayed Sequence Intubation

    DEFF Research Database (Denmark)

    Weingart, Scott D; Trueger, N Seth; Wong, Nelson

    2015-01-01

    assessed. RESULTS: A total of 62 patients were enrolled: 19 patients required delayed sequence intubation to allow nonrebreather mask, 39 patients required it to allow NIPPV, and 4 patients required it for nasogastric tube placement. Saturations increased from a mean of 89.9% before delayed sequence...

  7. American Dream Delayed

    DEFF Research Database (Denmark)

    Khorunzhina, Natalia; Miller, Robert A.

    This paper investigates the delay in homeownership and a subsequent reduction in homeownership rate observed over the past decades. We focus on the delay in giving birth to children and increased labor market participation as contributing factors to homeownership dynamics for prime-age female hou......, fertility decisions and labor supply alternatives faced by the individuals over different stages of the life cycle. The delays in giving birth and buying first home arise endogenously.......This paper investigates the delay in homeownership and a subsequent reduction in homeownership rate observed over the past decades. We focus on the delay in giving birth to children and increased labor market participation as contributing factors to homeownership dynamics for prime-age female...

  8. Air congestion delay: a review

    Directory of Open Access Journals (Sweden)

    Daniel Alberto Pamplona

    2016-04-01

    Full Text Available This article is a literature review of the air congestion delay and its costs. Air congestion is a worldwide problem. Its existence brings costs for airlines and discomfort for passengers. With the increasing demand for air transport, the study of air congestion has attracted the attention of many researchers around the world. The cause for the delays is erroneously attributed only to the lack of infrastructure investments. The literature review shows that other factors such as population growth, increasing standards of living, lack of operational planning and environmental issues exercise decisive influence. Several studies have been conducted in order to analyze and propose solutions to this problem that affects society as a whole.

  9. Assessment of early diastolic intraventricular pressure gradient in the left ventricle among patients with repaired tetralogy of Fallot.

    Science.gov (United States)

    Kobayashi, Maki; Takahashi, Ken; Yamada, Mariko; Yazaki, Kana; Matsui, Kotoko; Tanaka, Noboru; Shigemitsu, Sachie; Akimoto, Katsumi; Kishiro, Masahiko; Nakanishi, Keisuke; Kawasaki, Shiori; Nii, Masaki; Itatani, Keiichi; Shimizu, Toshiaki

    2017-11-01

    Assessment of left ventricular (LV) dysfunction is vital in patients with repaired tetralogy of Fallot (rTOF). The early diastolic intraventricular pressure gradient (IVPG) in the LV plays an important role in diastolic function. IVPG is calculated as the intraventricular pressure difference divided by the LV length, which allows to account for differences in LV size and therefore calculate IVPG in children. We aimed to investigate the mechanisms of LV diastolic dysfunction by measuring mid-to-apical IVPG as an indicator of the active suction force sucking blood from the left atrium into the LV. We included 38 rTOF patients and 101 healthy controls. The study population was stratified based on age group into children (4-9 years), adolescents (10-15 years), and adults (16-40 years). IVPGs were calculated based on mitral inflow measurements obtained using color M-mode Doppler echocardiography. Although total IVPGs did not differ between rTOF patients and controls, mid-to-apical IVPGs in adolescents and adults were smaller among rTOF patients than among controls (0.15 ± 0.05 vs. 0.21 ± 0.06 mmHg/cm, p < 0.05; 0.09 ± 0.07 vs. 0.17 ± 0.05 mmHg/cm, p < 0.001; respectively). Additionally, only mid-to-apical IVPG correlated linearly with peak circumferential strain (ρ = 0.217, p = 0.011), longitudinal strain (ρ = -0.231, p = 0.006), torsion (ρ = -0.200, p = 0.018), and untwisting rate in early diastole (ρ = -0.233, p = 0.006). In rTOF, the mechanisms underlying diastolic dysfunction involve reduced active suction force, which correlates with reduced LV deformation in all directions.

  10. Dispositivo de assistência circulatória mecânica intraventricular de fluxo axial: estudo in vitro In vitro evaluation of an intraventricular axial flow pump for mechanical circulatory support

    Directory of Open Access Journals (Sweden)

    Luiz Fernando KUBRUSLY

    2000-06-01

    Full Text Available É apresentado estudo in vitro de um dispositivo de assistência circulatória totalmente implantável no ventrículo esquerdo, de fluxo axial e de tamanho pequeno (30 cc - 7 cm comprimento. Apesar dessas características foi capaz de gerar fluxos entre 5 - 8 l/min com motor, operando em 8 W, sem causar hemólise em período de até 12 horas. O custo de produção, excetuando-se o sistema de baterias, foi projetado entre 5 - 8 mil dólares, o que o torna viável para utilização clínica rotineira em nosso país.We are currently studying an intraventricular axial flow blood pump in vitro. It is designed for long term left ventricular support. The small (30 cc, 7 cm length was capable of producing flows of 5 - 8 l/min on a 8 W motor, with no device related hemolysis throughout the 12 h of the study. The cost of production, except for the batteries, has been estimated at between 5 - 8 thousand dollars, a reasonable amount for routine clinical use in Brazil.

  11. Delayed power analysis

    International Nuclear Information System (INIS)

    Adamovich, L.A.; Azarov, V.V.

    1999-01-01

    Time dependent core power behavior in a nuclear reactor is described with well-known neutron kinetics equations. At the same time, two portions are distinguished in energy released from uranium nuclei fission; one released directly at fission and another delayed (residual) portion produced during radioactive decay of fission products. While prompt power is definitely described with kinetics equations, the delayed power presentation still remains outstanding. Since in operation the delayed power part is relatively small (about 6%) operation, it can be neglected for small reactivity disturbances assuming that entire power obeys neutron kinetics equations. In case of a high negative reactivity rapidly inserted in core (e.g. reactor scram initiation) the prompt and delayed components can be calculated separately with practically no impact on each other, employing kinetics equations for prompt power and known approximation formulas for delayed portion, named residual in this specific case. Under substantial disturbances the prompt component in the dynamic process becomes commensurable with delayed portion, thus making necessary to take into account their cross impact. A system of differential equations to describe time-dependent behavior of delayed power is presented. Specific NPP analysis shows a way to significantly simplify the task formulation. (author)

  12. Delayed radiation neuropathy

    International Nuclear Information System (INIS)

    Nagashima, Toshiko; Miyamoto, Kazuto; Beppu, Hirokuni; Hirose, Kazuhiko; Yamada, Katsuhiro

    1981-01-01

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author)

  13. Delayed radiation neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Nagashima, T.; Miyamoto, K.; Beppu, H.; Hirose, K.; Yamada, K. (Tokyo Metropolitan Neurological Hospital (Japan))

    1981-07-01

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author).

  14. Conduct disorder

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000919.htm Conduct disorder To use the sharing features on this page, please enable JavaScript. Conduct disorder is a set of ongoing emotional and behavioral ...

  15. School-age outcomes of very low birth weight infants in the indomethacin intraventricular hemorrhage prevention trial.

    Science.gov (United States)

    Vohr, Betty R; Allan, Walter C; Westerveld, Michael; Schneider, Karen C; Katz, Karol H; Makuch, Robert W; Ment, Laura R

    2003-04-01

    The cohort consisted of 328 very low birth weight infants (600-1250 g birth weight) who were enrolled in the low-dose prophylactic indomethacin prevention trial and were intraventricular hemorrhage (IVH) negative at 6 postnatal hours. The objective was to determine the effects of both IVH and indomethacin on cognitive, language, and achievement performance at 8 years of age. The cohort was divided into 4 subgroups for analysis: indomethacin plus IVH, indomethacin no IVH, saline plus IVH, and saline with no IVH. The children were evaluated prospectively at 8 years of age with a neurologic assessment, history of school performance, and a battery of cognitive, academic, behavioral, and functional assessments. Children in both IVH groups had more cerebral palsy; more hearing impairment; lower daily living skills scores; lower IQ, vocabulary, and reading and mathematics achievement test scores; and greater educational resource needs. With logistic regression analyses grade 3 to 4 IVH, periventricular leukomalacia and/or ventriculomegaly, male gender, maternal education, and language spoken in the home contributed to outcomes. No effects of indomethacin or gestational age were identified. Although biological factors including IVH, ventriculomegaly, and periventricular leukomalacia contribute significantly to school age outcomes among very low birth weight survivors at 8 years of age, social and environmental factors including maternal level of education and primary language spoken in the home are also important contributors to outcome.

  16. Rare cause of right heart failure: contained rupture of a sinus of Valsalva aneurysm associated intraventricular septal aneurysm.

    Science.gov (United States)

    Mookadam, F; Haley, J; Mendrick, Ed

    2005-06-01

    Sinus of Valsalva aneurysm (SVA) is a rare congenital lesion described first in 1840 by John Thurnam (Cited by Boutefou JM, Moret PR, Hahn C, Hanf E. Aneurysms of the sinus of Valsalva: report of seven cases and review of the literature. Am J Med 1978;65:18-24). In most cases unruptured Sinus of Valsalva aneurysm (SVA) is clinically silent; however, if it progressively enlarges it may cause coronary artery compression, complete heart block, or right ventricular outflow tract obstruction (Meier JH, Seward JD, Miller FA, Oh J, Sarano ME. Aneurysms in the left ventricular outflow tract: clinical presentation, causes, and echocardiographic features. J Am Soc Echocardiogr 1998;11:729-45; D'Silva SA, Dalve BV, Lokhandwala YY, Kale PA, Tendolkar AG. Unruptured congenital aneurysm of the left sinus of Valsalva presenting as acute right heart failure. Chest 1992;101:578-79) or is a potential source of cerebrovascular emboli. (Shahrabani RM, Jairaj PS. Unruptured aneurysm of the sinus of Valsalva: a potential source of cerebrovascular embolism. Br Heart J 1993;69:266-67). In this report, we describe a case of right coronary sinus of Valsalva aneurysm with a contained rupture. The containing rupture is in intraventricular septal aneurysm; the patient presents with right-sided heart failure.

  17. Low-grade intraventricular hemorrhage disrupts cerebellar white matter in preterm infants: evidence from diffusion tensor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Takashi; Morimoto, Masafumi; Hasegawa, Tatsuji; Morioka, Shigemi; Kidowaki, Satoshi; Moroto, Masaharu; Yamashita, Satoshi; Maeda, Hiroshi; Chiyonobu, Tomohiro; Tokuda, Sachiko; Hosoi, Hajime [Kyoto Prefectural University of Medicine, Department of Pediatrics, Graduate School of Medical Science, Kyoto (Japan); Yamada, Kei [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science, Kyoto (Japan)

    2015-05-01

    Recent diffusion tensor imaging (DTI) studies have demonstrated that leakage of hemosiderin into cerebrospinal fluid (CSF), which is caused by high-grade intraventricular hemorrhage (IVH), can affect cerebellar development in preterm born infants. However, a direct effect of low-grade IVH on cerebellar development is unknown. Thus, we evaluated the cerebellar and cerebral white matter (WM) of preterm infants with low-grade IVH. Using DTI tractography performed at term-equivalent age, we analyzed 42 infants who were born less than 30 weeks gestational age (GA) at birth (22 with low-grade IVH, 20 without). These infants were divided into two birth groups depending on GA, and we then compared the presence and absence of IVH which was diagnosed by cerebral ultrasound (CUS) within 10 days after birth or conventional magnetic resonance imaging (MRI) at term-equivalent age in each group. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) at the superior cerebellar peduncle (SCP), middle cerebellar peduncle (MCP), motor tract, and sensory tract were measured. In the SCP, preterm born infants with IVH had lower FA values compared with infants without IVH. In particular, younger preterm birth with IVH had lower FA values in the SCP and motor tract and higher ADC values in the MCP. Low-grade IVH impaired cerebellar and cerebral WM, especially in the SCP. Moreover, younger preterm infants exhibited greater disruptions to cerebellar WM and the motor tract than infants of older preterm birth. (orig.)

  18. Retrograde intraventricular hemorrhage caused by a traumatic sacral pseudomeningocele in the presence of spina bifida occulta. Case report.

    Science.gov (United States)

    Uff, Christopher; Bradford, Robert

    2005-11-01

    The authors present the case of a large, posttraumatic sacral pseudomeningocele in the presence of spina bifida occulta. A pseudomeningocele in the sacral region is associated with trauma and with Marfan syndrome, but only one occurrence has been reported in association with spinal dysraphism. Trauma resulted in bleeding into the pseudomeningocele and retrograde passage of blood and fat into the ventricles. An oculomotor nerve palsy subsequently developed in the patient. The authors suspected a subarachnoid hemorrhage caused by a posterior communicating artery aneurysm, although this hypothesis was refuted on further investigation. The pseudomeningocele was drained by direct exposure of the neck and opening of the sac. Postoperatively, communicating hydrocephalus developed and the patient underwent ventriculoperitoneal shunt placement, resulting in resolution of the cranial nerve palsies. This first report of intradural bleeding from direct trauma to a pseudomeningocele illustrates the rare phenomenon of retrograde passage of blood from the sacral region to the brain. It also illustrates a possible but unlikely differential diagnosis of intraventricular blood and fat.

  19. Reduced cerebral blood flow and oxygen metabolism in extremely preterm neonates with low-grade germinal matrix- intraventricular hemorrhage

    Science.gov (United States)

    Lin, Pei-Yi; Hagan, Katherine; Fenoglio, Angela; Grant, P. Ellen; Franceschini, Maria Angela

    2016-05-01

    Low-grade germinal matrix-intraventricular hemorrhage (GM-IVH) is the most common complication in extremely premature neonates. The occurrence of GM-IVH is highly associated with hemodynamic instability in the premature brain, yet the long-term impact of low-grade GM-IVH on cerebral blood flow and neuronal health have not been fully investigated. We used an innovative combination of frequency-domain near infrared spectroscopy and diffuse correlation spectroscopy (FDNIRS-DCS) to measure cerebral oxygen saturation (SO2) and an index of cerebral blood flow (CBFi) at the infant’s bedside and compute an index of cerebral oxygen metabolism (CMRO2i). We enrolled twenty extremely low gestational age (ELGA) neonates (seven with low-grade GM-IVH) and monitored them weekly until they reached full-term equivalent age. During their hospital stay, we observed consistently lower CBFi and CMRO2i in ELGA neonates with low-grade GM-IVH compared to neonates without hemorrhages. Furthermore, lower CBFi and CMRO2i in the former group persists even after the resolution of the hemorrhage. In contrast, SO2 does not differ between groups. Thus, CBFi and CMRO2i may have better sensitivity than SO2 in detecting GM-IVH-related effects on infant brain development. FDNIRS-DCS methods may have clinical benefit for monitoring the evolution of GM-IVH, evaluating treatment response, and potentially predicting neurodevelopmental outcome.

  20. Prediction of intraventricular haemorrhage in preterm infants using time series analysis of blood pressure and respiratory signals

    Science.gov (United States)

    Huvanandana, Jacqueline; Nguyen, Chinh; Thamrin, Cindy; Tracy, Mark; Hinder, Murray; McEwan, Alistair L.

    2017-04-01

    Despite the decline in mortality rates of extremely preterm infants, intraventricular haemorrhage (IVH) remains common in survivors. The need for resuscitation and cardiorespiratory management, particularly within the first 24 hours of life, are important factors in the incidence and timing of IVH. Variability analyses of heart rate and blood pressure data has demonstrated potential approaches to predictive monitoring. In this study, we investigated the early identification of infants at a high risk of developing IVH, using time series analysis of blood pressure and respiratory data. We also explore approaches to improving model performance, such as the inclusion of multiple variables and signal pre-processing to enhance the results from detrended fluctuation analysis. Of the models we evaluated, the highest area under receiver-operator characteristic curve (5th, 95th percentile) achieved was 0.921 (0.82, 1.00) by mean diastolic blood pressure and the long-term scaling exponent of pulse interval (PI α2), exhibiting a sensitivity of >90% at a specificity of 75%. Following evaluation in a larger population, our approach may be useful in predictive monitoring to identify infants at high risk of developing IVH, offering caregivers more time to adjust intensive care treatment.

  1. Delayed puberty in boys

    Science.gov (United States)

    ... In most cases, delayed puberty is simply a matter of growth changes beginning later than usual, sometimes ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  2. Delayed puberty in girls

    Science.gov (United States)

    ... with too little body fat, gaining a bit of weight may help trigger puberty. If delayed puberty is caused by a disease or an eating disorder, treating the cause may help puberty to develop normally. If puberty ...

  3. Conducting Polymers

    Indian Academy of Sciences (India)

    would exhibit electronic conductivity, their conductivities (of compressed pellets) were indeed measured by others, and were found to be .... Polyaniline. Polyphenylene. Polypheny lene- vinylene. Table 1. G!NeRAl I ARTICl! structure. Maximum conductivity Stem Stability. Processability. ~. 1.5 x 105. Reacts with Film not n air.

  4. Vernier Delay Unit

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, W.B.

    1984-10-01

    This module will accept differential ECL pulses from the auxiliary rear panel or NIM level pulses from the front panel. The pulses are produced at the output with a fixed delay that is software programmable in steps of 0.1 ns over the range of 0.1 to 10.5 ns. Multiple outputs are available at the front panel. Minimum delay through the module is 9 ns.

  5. Choice and reinforcement delay

    OpenAIRE

    Gentry, G. David; Marr, M. Jackson

    1980-01-01

    Previous studies of choice between two delayed reinforcers have indicated that the relative immediacy of the reinforcer is a major determinant of the relative frequency of responding. Parallel studies of choice between two interresponse times have found exceptions to this generality. The present study looked at the choice by pigeons between two delays, one of which was always four times longer than the other, but whose absolute durations were varied across conditions. The results indicated th...

  6. Modelling delays in pharmacokinetics

    International Nuclear Information System (INIS)

    Farooqi, Z.H.; Lambrecht, R.M.

    1990-01-01

    Linear system analysis has come to form the backbone of pharmacokinetics. Natural systems usually involve time delays, thus models incorporating them would be an order closer approximation to the real world compared to those that do not. Delays may be modelled in several ways. The approach considered in this study is to have a discrete-time delay dependent rate with the delay respresenting the duration between the entry of a drug into a compartment and its release in some form (may be as a metabolite) from the compartment. Such a delay may be because of one or more of several physiological reasons, like, formation of a reservoir, slow metabolism, or receptor binding. The mathematical structure this gives rise to is a system of delay-differential equations. Examples are given of simple one and two compartment systems with drugs like bumetanide, carbamazepine, and quinolone-caffeine interaction. In these examples generally a good fit is obtained and the suggested models form a good approximation. 21 refs., 6 figs

  7. Conduct Disorder

    Science.gov (United States)

    ... do not receive early and comprehensive treatment . Without treatment, many youngsters with conduct disorder are unable to adapt to the demands of ... break laws or behave in an antisocial manner. Treatment of children with conduct disorder can be complex and challenging. Treatment can be ...

  8. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2011-01-01

    Studies of complications following reconstructive surgery with implants among women with breast cancer are needed. As the, to our knowledge, first prospective long-term study we evaluated the occurrence of complications following delayed breast reconstruction separately for one- and two......-stage procedures. From the Danish Registry for Plastic Surgery of the Breast, which has prospectively registered data for women undergoing breast implantations since 1999, we identified 559 women without a history of radiation therapy undergoing 592 delayed breast reconstructions following breast cancer during...... of reoperation was significantly higher following the one-stage procedure. For both procedures, the majority of reoperations were due to asymmetry or displacement of the implant. In conclusion, non-radiated one- and two-stage delayed breast implant reconstructions are associated with substantial risks...

  9. Neonatal Acute Kidney Injury and the Risk of Intraventricular Hemorrhage in the Very Low Birth Weight Infant.

    Science.gov (United States)

    Stoops, Christine; Sims, Brian; Griffin, Russell; Askenazi, D J

    2016-01-01

    Despite improvements in survival of premature infants, many have comorbid conditions. The role of the kidney in multiorgan dysfunction is unclear, particularly in regard to intraventricular hemorrhage (IVH). We hypothesized that infants diagnosed with acute kidney injury (AKI) have an increased risk of IVH independent of gestational age (GA) and other variables associated with both comorbidities. This prospective cohort study consisted of 125 infants with a birth weight ≤1,200 g and/or GA ≤31 weeks. A definition of AKI was used from KDIGO, not including urine output as nonoliguria is common in this population. IVH was based on serial head ultrasounds. Neonates with AKI had a higher trend towards having IVH compared to those without [14/35 (40%) vs. 22/83 (26.5%), p = 0.1]. Infants with AKI were more likely to have stage 2 IVH or higher than those without AKI [12/36 (33.3%) vs. 6/82 (7.3%); p < 0.01]. AKI was associated with a 3.6-fold increased risk of a grade 2 or higher IVH [hazard ratio (HR) 3.55, 95% confidence interval (CI) 1.39-9.07] and over 4-fold increase in risk of a grade 3 or higher IVH (HR 4.34, 95% CI 1.43-13.21). While there was no association between AKI and IVH overall, those with AKI had a higher hazard ratio to develop a grade 2 or higher IVH even when controlling for birth weight, antenatal steroid use, and 5-min Apgar score. Future studies are indicated to expand sample size and to control for other clinical variables that could be associated with both AKI and IVH. © 2016 S. Karger AG, Basel.

  10. Trends in hospitalization of preterm infants with intraventricular hemorrhage and hydrocephalus in the United States, 2000-2010.

    Science.gov (United States)

    Christian, Eisha A; Jin, Diana L; Attenello, Frank; Wen, Timothy; Cen, Steven; Mack, William J; Krieger, Mark D; McComb, J Gordon

    2016-03-01

    OBJECT Even with improved prenatal and neonatal care, intraventricular hemorrhage (IVH) occurs in approximately 25%-30% of preterm infants, with a subset of these patients developing hydrocephalus. This study was undertaken to describe current trends in hospitalization of preterm infants with posthemorrhagic hydrocephalus (PHH) using the Nationwide Inpatient Sample (NIS) and the Kids' Inpatient Database (KID). METHODS The KID and NIS were combined to generate data for the years 2000-2010. All neonatal discharges with ICD-9-CM codes for preterm birth with IVH alone or with IVH and hydrocephalus were included. RESULTS There were 147,823 preterm neonates with IVH, and 9% of this group developed hydrocephalus during the same admission. Of patients with Grade 3 and 4 IVH, 25% and 28%, respectively, developed hydrocephalus in comparison with 1% and 4% of patients with Grade 1 and 2 IVH, respectively. Thirty-eight percent of patients with PHH had permanent ventricular shunts inserted. Mortality rates were 4%, 10%, 18%, and 40%, respectively, for Grade 1, 2, 3, and 4 IVH during initial hospitalization. Length of stay has been trending upward for both groups of IVH (49 days in 2000, 56 days in 2010) and PHH (59 days in 2000, 70 days in 2010). The average hospital cost per patient (adjusted for inflation) has also increased, from $201,578 to $353,554 (for IVH) and $260,077 to $495,697 (for PHH) over 11 years. CONCLUSIONS The number of neonates admitted with IVH has increased despite a decrease in the number of preterm births. Rates of hydrocephalus and mortality correlated closely with IVH grade. The incidence of hydrocephalus in preterm infants with IVH remained stable between 8% and 10%. Over an 11-year period, there was a progressive increase in hospital cost and length of stay for preterm neonates with IVH and PHH that may be explained by a concurrent increase in the proportion of patients with congenital cardiac anomalies.

  11. Electrical Conductivity.

    Science.gov (United States)

    Hershey, David R.; Sand, Susan

    1993-01-01

    Explains how electrical conductivity (EC) can be used to measure ion concentration in solutions. Describes instrumentation for the measurement, temperature dependence and EC, and the EC of common substances. (PR)

  12. Delayed photon selfinterference

    International Nuclear Information System (INIS)

    Kessel', A.R.; Moiseev, S.A.

    1993-01-01

    Delayed photon selfinterference on a sample containing resonant two-level atoms is considered when the difference in the lengths in two optical paths exceeds the photon 'length'. It is shown that a reading pulse of the electromagnetic field can induce photon echo

  13. Permissible Delay in Payments

    Directory of Open Access Journals (Sweden)

    Yung-Fu Huang

    2007-01-01

    Full Text Available The main purpose of this paper wants to investigate the optimal retailer's lot-sizing policy with two warehouses under partially permissible delay in payments within the economic order quantity (EOQ framework. In this paper, we want to extend that fully permissible delay in payments to the supplier would offer the retailer partially permissible delay in payments. That is, the retailer must make a partial payment to the supplier when the order is received. Then the retailer must pay off the remaining balance at the end of the permissible delay period. In addition, we want to add the assumption that the retailer's storage space is limited. That is, the retailer will rent the warehouse to store these exceeding items when the order quantity is larger than retailer's storage space. Under these conditions, we model the retailer's inventory system as a cost minimization problem to determine the retailer's optimal cycle time and optimal order quantity. Three theorems are developed to efficiently determine the optimal replenishment policy for the retailer. Finally, numerical examples are given to illustrate these theorems and obtained a lot of managerial insights.

  14. Estimating Delays In ASIC's

    Science.gov (United States)

    Burke, Gary; Nesheiwat, Jeffrey; Su, Ling

    1994-01-01

    Verification is important aspect of process of designing application-specific integrated circuit (ASIC). Design must not only be functionally accurate, but must also maintain correct timing. IFA, Intelligent Front Annotation program, assists in verifying timing of ASIC early in design process. This program speeds design-and-verification cycle by estimating delays before layouts completed. Written in C language.

  15. Delays of Interconnected Flows

    Science.gov (United States)

    Sorger, U.; Suchanecki, Z.

    2011-07-01

    A rigorous approach to flows of particles in networks is presented. Under the assumption of independence of the transversal flows the asymptotic distributions of inter-delay times between particles are shown to be log-normal. In the case of dependent transversal traffic the ARCH and GARCH time series models, as well as martingale approach, have been applied.

  16. Plasmas for Transition Delay

    NARCIS (Netherlands)

    Kotsonis, M.; Boon, P.; Veldhuis, L.

    2009-01-01

    This paper describes the experimental investigation of the properties of Dielectric Barrier Discharge (DBD) actuators aimed at transition delay techniques. A wide range of geometrical configurations are tested as well as several electrical operational conditions. For the majority of the measurements

  17. [Diagnosis delay of pleural and pulmonary tuberculosis].

    Science.gov (United States)

    Cherif, J; Mjid, M; Ladhar, A; Toujani, S; Mokadem, S; Louzir, B; Mehiri, N; Béji, M

    2014-08-01

    Tuberculosis (TB) is still being endemic in our country. Time until management determines both evolution and prognosis of this condition. The aim of this work is to evaluate the delay in diagnosis of TB in a respiratory unit from a university hospital series. The authors conducted a cross-sectional study including patients with pulmonary TBC and/or pleural. An evaluation of time management was conducted from the beginning of symptoms and various consultations with reference to the date of hospitalization and treatment set up. One hundred patients were included (pulmonary TB: 68 cases, pleural TB 23 cases, miliary pulmonary TB: 4 cases, pulmonary TB associated with other extrathoracic locations: 5 cases). The mean time of patient delay and total delay institution were respectively 43.6, 25.7 and 69.3 days. Variables responsible for long delays were: number of consultations more than 3 before hospitalization, empirical antibiotic therapy, of a regional hospital first consultation and the presence of extra-respiratory impairment. The patient delay was considered long. A reorganization of the TB control program, in particular by partial decentralization of care and health education is imperative in order to improve the quality of tuberculosis management in our country. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  18. Delayed auditory feedback and aphasia.

    Science.gov (United States)

    Boller, F; Vrtunski, P B; Kim, Y; Mack, J L

    1978-06-01

    The effect of Delayed Auditory Feedback (DAF) was evaluated in three groups of subjects: 10 normal controls, 10 non-fluent aphasics, and 10 fluent aphasics. Speec production tasks consisted of (1) repeating sound and words; (2) naming objects; (3) producing sentences from given stimulus words; (4) answering questions; (5) reciting nursery rhymes; and (6) reading. Two delays were used, 180 and 360 msec. Two independent judges rated patients' responses for changes in intensity, duration, and quality of speech. Inter-judge reliability was considered satisfactory. Contrary to some previous reports, all subjects, including all the fluent aphasics, showed some DAF effect. Fluent aphasics, however, showed a significantly smaller DAF effect than non-fluent aphasics. Patient with conduction aphasia appeared to be the least impaired. Overall DAF effect was greater with 180 msec. than with 360 msec. The largest DAF effect occurred during answering question, followed by repeating, reading, nursery rhymes, sentence production, and naming, in that order. Repetition of a complex word produced a greater DAF effect than repetition of a simple sound. Finally, we found a differential effect of DAF on the three measures used in the study. We hypothesize that DAF effects result from changes in two separate monitoring systems. One systems is related to changes in the intensity of speech and does not appear to be affected by aphasia. The other is responsible for duration and qualitative changes in speech and is differentially affected in relation to pathology producing aphasia.

  19. Conducting Polymers

    Indian Academy of Sciences (India)

    backbone (by the process of doping) and make them electrically. Conducting Polymers. From a Laboratory Curiosity to the Market Place. S Ramakrishnan ..... switching occurs between transparent yellow and green in less than. 100ms. Thus, while these materials are yet to achieve the set target. (in terms of their life cycle) ...

  20. Conducting Polymers

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Conducting Polymers - From a Laboratory Curiosity to the Market Place. S Ramakrishnan. Volume 16 Issue 12 December 2011 pp 1254-1265. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Conduct disorders

    NARCIS (Netherlands)

    Buitelaar, J.K.; Smeets, K.C.; Herpers, P.; Scheepers, F.; Glennon, J.; Rommelse, N.N.J.

    2013-01-01

    Conduct disorder (CD) is a frequently occurring psychiatric disorder characterized by a persistent pattern of aggressive and non-aggressive rule breaking antisocial behaviours that lead to considerable burden for the patients themselves, their family and society. This review paper updates diagnostic

  2. Delays in seeking treatment for symptomatic tuberculosis in Sabah, East Malaysia: factors for patient delay.

    Science.gov (United States)

    Rundi, C; Fielding, K; Godfrey-Faussett, P; Rodrigues, L C; Mangtani, P

    2011-09-01

    The state of Sabah contributes one third of the tuberculosis (TB) cases in Malaysia. To collect information on factors that affect the time period from the onset of symptoms to first contact with health care providers, whether private or government. A cross-sectional study using a pre-tested questionnaire was conducted among 296 newly registered smear-positive TB patients in 10 districts in Sabah. Univariable and multivariable analyses were used to determine which risk factors were associated with patient delay (>30 days) and 'extreme' patient delay (>90 days). The percentage of patients who sought treatment after 30 and 90 days was respectively 51.8% (95%CI 45.7-57.9) and 23.5% (95%CI 18.6-29.0). The strongest factors associated with patient delay and 'extreme' patient delay was when the first choice for treatment was a non-government health facility and in 30-39-year-olds. 'Extreme' patient delay was also weakly associated, among other factors, with comorbidity and livestock ownership. Delay and extreme delay in seeking treatment were more common when the usual first treatment choice was a non-government health facility. Continuous health education on TB aimed at raising awareness and correcting misconceptions is needed, particularly among those who use non-government facilities.

  3. Exercise-induced intra-ventricular gradients as a frequent potential cause of myocardial ischemia in cardiac syndrome X patients

    Directory of Open Access Journals (Sweden)

    Almeida Ana G

    2008-01-01

    Full Text Available Abstract Background The development of intra-ventricular gradients (IVG during dobutamine or exercise stress is not infrequent, and can be associated to symptoms during stress. The purpose of this study was to assess the occurrence of IVG during exercise stress echocardiography in cardiac syndrome X patients. Methods We prospectively evaluated 91 patients (pts mean aged 51 ± 12 years (age ranged 20 to 75 years old, 44 of whom were women. All pts had angina, positive exercise ECG treadmill testing, normal rest echocardiogram and no coronary artery disease on coronary angiogram (cardiac X syndrome. After complete Doppler echocardiographic evaluation with determination of left ventricular outflow tract index (LVOTi, relative left ventricular wall thickness (RLVWT and left ventricular end-diastolic volume index (LVDVi, all patients underwent stress echocardiography with two-dimensional and Doppler echographic evaluation during and after treadmill exercise. Results For analysis purpose patients were divided in 2 groups, according to the development of IVG. Doppler evidence of IVG was found in 33 (36% of the patients (Group A, with mean age 47 ± 14 years old (age ranged 20 to 72 years and with a mean end-systolic peak gradient of 86 ± 34 mmHg (ranging from 30 to 165 mmHg. The IVG development was accompanied by SAM of the mitral valve in 23 pts. Three of these pts experienced symptomatic hypotension. Ten were women (30% pts. 58 pts in group B, 34 of whom were women (59% (p = 0,01 vs group A, mean aged 53,5 ± 10,9 years old (age ranged 34 to 75 years (p = 0,03 vs group A, did not develop IVG. LVOTi was 10,29 ± 0,9 mm/m2 in group A and 11,4 ± 1 mm/m2 in group B (p 2 in group A and 56 ± 11,6 ml/m2 in group B (p = 0,000. Conclusion 1. A significant number of patients with cardiac X syndrome developed IVG during upright exercise in treadmill. These pts (group A are mainly males and younger than those who did not develop IVG. 2. The development of IVG

  4. Time-Delay Interferometry

    Directory of Open Access Journals (Sweden)

    Massimo Tinto

    2014-08-01

    Full Text Available Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI. This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

  5. Neurobiological effects of intraventricular propionic acid in rats: possible role of short chain fatty acids on the pathogenesis and characteristics of autism spectrum disorders.

    Science.gov (United States)

    MacFabe, Derrick F; Cain, Donald P; Rodriguez-Capote, Karina; Franklin, Andrew E; Hoffman, Jennifer E; Boon, Francis; Taylor, A Roy; Kavaliers, Martin; Ossenkopp, Klaus-Peter

    2007-01-10

    Clinical observations suggest that certain gut and dietary factors may transiently worsen symptoms in autism spectrum disorders (ASD), epilepsy and some inheritable metabolic disorders. Propionic acid (PPA) is a short chain fatty acid and an important intermediate of cellular metabolism. PPA is also a by-product of a subpopulation of human gut enterobacteria and is a common food preservative. We examined the behavioural, electrophysiological, neuropathological, and biochemical effects of treatment with PPA and related compounds in adult rats. Intraventricular infusions of PPA produced reversible repetitive dystonic behaviours, hyperactivity, turning behaviour, retropulsion, caudate spiking, and the progressive development of limbic kindled seizures, suggesting that this compound has central effects. Biochemical analyses of brain homogenates from PPA treated rats showed an increase in oxidative stress markers (e.g., lipid peroxidation and protein carbonylation) and glutathione S-transferase activity coupled with a decrease in glutathione and glutathione peroxidase activity. Neurohistological examinations of hippocampus and adjacent white matter (external capsule) of PPA treated rats revealed increased reactive astrogliosis (GFAP immunoreactivity) and activated microglia (CD68 immunoreactivity) suggestive of a neuroinflammatory process. This was coupled with a lack of cytotoxicity (cell counts, cleaved caspase 3' immunoreactivity), and an increase in phosphorylated CREB immunoreactivity. We propose that some types of autism may be partial forms of genetically inherited or acquired disorders involving altered PPA metabolism. Thus, intraventricular administration of PPA in rats may provide a means to model some aspects of human ASD in rats.

  6. Delayed antibiotic prescriptions for respiratory infections.

    Science.gov (United States)

    Spurling, Geoffrey Kp; Del Mar, Chris B; Dooley, Liz; Foxlee, Ruth; Farley, Rebecca

    2017-09-07

    ), streptococcal pharyngitis (three studies), cough (two studies), sore throat (one study), common cold (one study), and a variety of RTIs (one study). Five studies involved only children, two only adults, and four included both adults and children. Six studies were conducted in a primary care setting, three in paediatric clinics, and two in emergency departments.Studies were well reported, and appeared to be of moderate quality. Randomisation was not adequately described in two trials. Four trials blinded the outcomes assessor, and three included blinding of participants and doctors. We conducted meta-analysis for antibiotic use and patient satisfaction.We found no differences among delayed, immediate, and no prescribed antibiotics for clinical outcomes in the three studies that recruited participants with cough. For the outcome of fever with sore throat, three of the five studies favoured immediate antibiotics, and two found no difference. For the outcome of pain related to sore throat, two studies favoured immediate antibiotics, and three found no difference. One study compared delayed antibiotics with no antibiotic for sore throat, and found no difference in clinical outcomes.Three studies included participants with acute otitis media. Of the two studies with an immediate antibiotic arm, one study found no difference for fever, and the other study favoured immediate antibiotics for pain and malaise severity on Day 3. One study including participants with acute otitis media compared delayed antibiotics with no antibiotics and found no difference for pain and fever on Day 3.Two studies recruited participants with common cold. Neither study found differences for clinical outcomes between delayed and immediate antibiotic groups. One study favoured delayed antibiotics over no antibiotics for pain, fever, and cough duration (moderate quality evidence for all clinical outcomes - GRADE assessment).There were either no differences for adverse effects or results favoured delayed

  7. Delayed Speech or Language Development

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Delayed Speech or Language Development KidsHealth / For Parents / Delayed Speech ... their child is right on schedule. How Are Speech and Language Different? Speech is the verbal expression ...

  8. Pneumoencéfalo intraventricular após perfuração acidental de dura-máter: relato de caso Pneumoencéfalo intraventricular después de la perforación accidental de dura-mater: relato de caso Intraventricular pneumocephalus after accidental perforation of the dura mater: case report

    Directory of Open Access Journals (Sweden)

    Fabiano Timbó Barbosa

    2006-10-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O uso de ar para a realização do teste da perda da resistência com a finalidade de identificar o espaço peridural é extremamente difundido no mundo inteiro, porém uma das complicações possíveis é a perfuração acidental de dura-máter que apresenta incidência estimada entre 1% e 2%. O objetivo deste relato foi descrever um caso de paciente com pneumoencéfalo intraventricular após perfuração acidental de dura-máter usando a técnica da perda da resistência com ar. RELATO DO CASO: Paciente do sexo feminino, 26 anos, 75 kg, 1,67 m, estado físico ASA I, com 38 semanas de gestação foi encaminhada ao centro obstétrico para realização de cesariana. Após monitorização foi realizada punção venosa. A paciente foi posicionada na posição sentada para realização de anestesia peridural. Durante a realização da identificação do espaço peridural com a técnica da perda da resistência usando-se ar, foi diagnosticada perfuração acidental da dura-máter por meio da observação de fluxo livre de líquor pela agulha. Foi modificada a técnica para raquianestesia e administradas medicações anestésicas através da agulha que já estava posicionada no espaço subaracnóideo. Nas primeiras 24 horas a paciente evoluiu com cefaléia que foi tratada com cafeína, dipirona, hidratação, hidrocortisona e repouso; mesmo assim, houve piora do quadro, passando a apresentar cefaléia até na posição de decúbito. Foi realizada tomografia computadorizada de crânio que evidenciou presença de pneumoencéfalo. Após consulta com especialista foi adotada conduta expectante com melhora progressiva do sintoma, com alta hospitalar no quinto dia de evolução, sem seqüelas. CONCLUSÕES: O pneumoencéfalo após perfuração acidental da dura-máter apresentou um quadro de cefaléia com características semelhantes àquela produzida pela perda liquórica, porém com resolução espontânea após absorção do ar

  9. Head midline position for preventing the occurrence or extension of germinal matrix-intraventricular hemorrhage in preterm infants.

    Science.gov (United States)

    Romantsik, Olga; Calevo, Maria Grazia; Bruschettini, Matteo

    2017-07-20

    Preterm birth is known to constitute the major risk factor for development of germinal matrix-intraventricular hemorrhage (GM-IVH). Head position may affect cerebral hemodynamics and thus may be involved indirectly in development of GM-IVH. Turning the head toward one side may functionally occlude jugular venous drainage on the ipsilateral side while increasing intracranial pressure and cerebral blood volume. Thus, it has been suggested that cerebral venous pressure is reduced and hydrostatic brain drainage improved if the patient is in supine midline position with the bed tilted 30°. The midline position might be achieved in the supine position and, with the use of physical aids, in the lateral position as well. Midline position should be kept, at least when the incidence of GM-IVH is greatest, that is, during the first two to three days of life. Primary objective To assess whether head midline position is more effective than any other head position for preventing or extending germinal matrix-intraventricular hemorrhage in infants born at ≤ 32 weeks' gestational age. Secondary objectives To perform subgroup analyses regarding gestational age, birth weight, intubated versus not intubated, and with or without GM-IVH at trial entry. We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8), MEDLINE via PubMed (1966 to September 19, 2016), Embase (1980 to September 19,.2016), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to September 19, 2016). We searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials. Randomized clinical controlled trials, quasi-randomized trials, and cluster-randomized controlled trials comparing placing very preterm infants in a head midline position versus placing them in a prone or lateral decubitus

  10. Conductivity Probe

    Science.gov (United States)

    2008-01-01

    The Thermal and Electrical Conductivity Probe (TECP) for NASA's Phoenix Mars Lander took measurements in Martian soil and in the air. The needles on the end of the instrument were inserted into the Martian soil, allowing TECP to measure the propagation of both thermal and electrical energy. TECP also measured the humidity in the surrounding air. The needles on the probe are 15 millimeters (0.6 inch) long. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  11. Echo determinants of dyssynchrony (atrioventricular and inter- and intraventricular) and predictors of response to cardiac resynchronization therapy.

    Science.gov (United States)

    Kapetanakis, Stamatis; Bhan, Amit; Monaghan, Mark J

    2008-10-01

    Cardiac resynchronization therapy (CRT) has revolutionized not only the treatment of chronic heart failure but also how we assess left ventricular (LV) dysfunction on echo. Increasingly, it has become clear that identifying and quantifying delays in events during the cardiac cycle is an important assessment in LV dysfunction as it has prognostic implications for patients undergoing CRT. The delays in atrioventricular, right-to-left ventricular, and LV segmental contraction have been shown to be important components in cardiac performance, and this review provides an overview of the commonest methods used for these assessments and their implications for selecting patients for biventricular pacing.

  12. Delayed Macular Hole Closure

    Directory of Open Access Journals (Sweden)

    Peter Distelmaier

    2014-04-01

    Full Text Available Purpose: The presented case raises questions regarding the favorable scheduling of planned postoperative care and the ideal observation interval to decide for reoperations in macular hole surgery. Furthermore a discussion about the use of short- and long-acting gas tamponades in macular hole surgery is encouraged. Methods: We present an interventional case report and a short review of the pertinent literature. Results: We report a case of spontaneous delayed macular hole closure after vitreoretinal surgery had been performed initially without the expected success. A 73-year-old male Caucasian patient presented at our clinic with a stage 2 macular hole in his left eye. He underwent 23-gauge pars plana vitrectomy and internal limiting membrane peeling with a 20% C2F6-gas tamponade. Sixteen days after the procedure, an OCT scan revealed a persistent stage 2 macular hole, and the patient was scheduled for reoperation. Surprisingly, at the date of planned surgery, which was another 11 days later, the macular hole had resolved spontaneously without any further intervention. Conclusions: So far no common opinion exists regarding the use of short- or long-acting gas in macular hole surgery. Our case of delayed macular hole closure after complete resorption of the gas tamponade raises questions about the need and duration of strict prone positioning after surgery. Furthermore short-acting gas might be as efficient as long-acting gas. We suggest to wait with a second intervention at least 4 weeks after the initial surgery, since a delayed macular hole closure is possible.

  13. Organophosphate induced delayed polyneuropathy.

    Science.gov (United States)

    Qureshi, Asif; Ali, Rajab; Yaqoob, M Yousuf; Saleem, Omema

    2007-07-01

    Organophosphate induced delayed polyneuropathy (OPIDP) is a rare sensory-motor distal axonopathy, which usually occur after ingestion of large doses of certain organophosphate insecticide. The clinical picture is characterized by the distal paresis in lower limb associated with sensory symptoms. Electrodiagnostic studies show a motor axonal neuropathy. This case occurred in a 14 years old girl who developed cramping pain in both calves associated with lower limbs paresis 6 weeks after accidental organophosphate poisoning. After another week, she also developed weakness in both hands. Electrophysiological study was characterized by an axonal polyneuropathy pattern. Patient improved upon oral multivitamin therapy and physiotherapy.

  14. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2012-01-01

    We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... of radiation therapy was associated with a non-significantly increased risk of reoperation after both 1-stage (HR = 1.4; 95% CI: 0.7-2.5) and 2-stage (HR = 1.6; 95% CI: 0.9-3.1) procedures. Reconstruction failure was highest (13.2%) in the 2-stage procedures with a history of radiation therapy. Breast...

  15. Concurrent Delay in Construction Disputes

    DEFF Research Database (Denmark)

    Cavaleri, Sylvie Cécile

    period of delay can potentially be attributed to several events falling within both parties' spheres of responsibility, commonly termed concurrent delay, is rarely regulated in construction contracts in spite of its common occurrence. This book analyses both the theoretical foundations and the practical......Delay is one of the issues most frequently encountered in today’s construction industry; it causes significant economic damage to all parties involved. Construction contracts, standard and bespoke, almost invariably consider delay from a perspective of single liability. If the event causing...... solutions to the issue of concurrent delay in a comparative perspective between common and civil law systems, with an emphasis on Danish and English law....

  16. Vehicle barrier with access delay

    Science.gov (United States)

    Swahlan, David J; Wilke, Jason

    2013-09-03

    An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

  17. Patient delay in cancer studies

    DEFF Research Database (Denmark)

    Andersen, Rikke Sand; Vedsted, Peter; Olesen, Frede

    2009-01-01

    BACKGROUND: There is no validated way of measuring the prevalence and duration of patient delay, and we do not know how people perceive and define the time intervals they are asked to report in patient delay studies. This lack of a validated measure hampers research in patient delay...... as symptoms related to a specific cancer diagnosis is embedded within a social and cultural context. We therefore cannot assume that respondents define delay periods in identical ways. SUMMARY: In order to improve the validity of patient delay studies, it is suggested that research be strengthened on three...

  18. Epidemiology of delayed ejaculation.

    Science.gov (United States)

    Di Sante, Stefania; Mollaioli, Daniele; Gravina, Giovanni Luca; Ciocca, Giacomo; Limoncin, Erika; Carosa, Eleonora; Lenzi, Andrea; Jannini, Emmanuele A

    2016-08-01

    A large body of literature on diminished ejaculatory disorders has been generated without the use of a clear diagnostic definition. Many studies have not distinguished between the orgasm and ejaculation disorders leading to doubtful results. Delayed ejaculation (DE) is one of the diminished ejaculatory disorders, which range from varying delays in ejaculatory latency to a complete inability to ejaculate. The present review is aimed at providing a comprehensive overview of the current knowledge on the definition and epidemiology of diminished ejaculatory disorders. We focus on the acquired diseases, such as benign prostatic hyperplasia (BPH) and specific drug regimens that may cause an iatrogenic form of ejaculatory disorder. In addition, the impact of aging is discussed since the prevalence of DE appears to be moderately but positively related to age. Finally, we also focus on the importance of the hormonal milieu on male ejaculation. To date, evidence on the endocrine control of ejaculation is derived from small clinical trials, but the evidence suggests that hormones modulate the ejaculatory process by altering its overall latency.

  19. Conduct disorders.

    Science.gov (United States)

    Buitelaar, Jan K; Smeets, Kirsten C; Herpers, Pierre; Scheepers, Floor; Glennon, Jeffrey; Rommelse, Nanda N J

    2013-02-01

    Conduct disorder (CD) is a frequently occurring psychiatric disorder characterized by a persistent pattern of aggressive and non-aggressive rule breaking antisocial behaviours that lead to considerable burden for the patients themselves, their family and society. This review paper updates diagnostic and therapeutic approaches to CD in the light of the forthcoming DSM-5 definition. The diagnostic criteria for CD will remain unchanged in DSM-5, but the introduction of a specifier of CD with a callous-unemotional (CU) presentation is new. Linked to this, we discuss the pros and cons of various other ways to subtype aggression/CD symptoms. Existing guidelines for CD are, with few exceptions, already of a relatively older date and emphasize that clinical assessment should be systematic and comprehensive and based on a multi-informant approach. Non-medical psychosocial interventions are recommended as the first option for the treatment of CD. There is a role for medication in the treatment of comorbid syndromes and/or in case of insufficient response to psychosocial interventions and severe and dangerous aggressive and violent behaviours.

  20. Relationship of Reaction Time to Perception of a Stimulus and Volitionally Delayed Response.

    Science.gov (United States)

    Meador, Kimford J; Boyd, Alan; Loring, David W

    2017-06-01

    Initiation of response in a simple reaction time (RT) task may precede conscious perception of the stimulus. Since volitionally delayed responses may require conscious perception of the stimulus before response initiation, it has been hypothesized that volitionally delayed responses will markedly delay RT. We conducted two experiments with separate groups of healthy volunteers (n=16; n=13) who performed computerized simple and choice RT tasks. In the standard condition, we instructed the participants to respond to a visual stimulus by pushing a button as quickly as possible. In the second condition, we instructed the participants to respond after a slight volitional delay. The second experiment had an additional volitional delay condition in which we asked participants to delay their responses by an estimated 50% above their usual standard response. We found marked delays and increased variability when participants volitionally delayed their responses, averaging 322 ms for standard and 861 ms for delayed simple RTs (267% increase), and 650 ms for standard and 1018 ms for delayed choice RTs (157% increase). Effects did not differ across age, sex, or handedness. However, a minority of participants did not meaningfully delay their RT during the volitional delay conditions. On average, participants had marked delays when they tried to delay their responses slightly, but a subset of participants exhibited essentially no delay despite trying to delay. We suggest some potential mechanisms that future investigations might delineate.

  1. Delayed cure bismaleimide resins

    Science.gov (United States)

    Adams, Johnnie E.; Jamieson, Donald R.

    1984-08-07

    Polybismaleimides prepared by delayed curing of bis-imides having the formula ##STR1## wherein R.sub.1 and R.sub.2 each independently is H, C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy, Cl or Br, or R.sub.1 and R.sub.2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R.sub.1 and R.sub.2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the --(CH.sub.2).sub.n -- group, optionally, is substituted by 1-3 methyl groups or by fluorine.

  2. Transfer delay audit.

    Science.gov (United States)

    Alraqi, S; Coughlan, R

    2007-05-01

    The purpose was to determine the average transfer time taken for acute patients to arrive to the medical unit from the time of referral by an A/E officer. We included the first 200 consecutive patients with completed records. 86 were men and 114 women, aged between 14 and 96 years. Transfer time was calculated as the difference from the time of referral by the A/E officer in UCHG to the time of arrival to the medical unit in MPH. The average transfer time for all patients was 91.5 minutes. The longest was in the second (17:00-24:00) interval with a mean of 105 minutes. 26.5% of patients arrived later than 2 hours after referral. Our findings confirm the existence of unacceptably long transfer time for a significant number of patients. Causes for this delay should be searched for to help find and implement solutions.

  3. Delay tolerant networks

    CERN Document Server

    Gao, Longxiang; Luan, Tom H

    2015-01-01

    This brief presents emerging and promising communication methods for network reliability via delay tolerant networks (DTNs). Different from traditional networks, DTNs possess unique features, such as long latency and unstable network topology. As a result, DTNs can be widely applied to critical applications, such as space communications, disaster rescue, and battlefield communications. The brief provides a complete investigation of DTNs and their current applications, from an overview to the latest development in the area. The core issue of data forward in DTNs is tackled, including the importance of social characteristics, which is an essential feature if the mobile devices are used for human communication. Security and privacy issues in DTNs are discussed, and future work is also discussed.

  4. Realistic head model design and 3D brain imaging of NIRS signals using audio stimuli on preterm neonates for intra-ventricular hemorrhage diagnosis.

    Science.gov (United States)

    Fournier, Marc; Mahmoudzadeh, Mahdi; Kazemi, Kamran; Kongolo, Guy; Dehaene-Lambertz, Ghislaine; Grebe, Reinhard; Wallois, Fabrice

    2012-01-01

    In this paper we propose an auditory stimulation and near infra-red spectroscopy (NIRS) hemodynamic changes acquisition protocol for preterm neonates. This study is designed to assess the specific characteristics of neurovascular coupling to auditory stimuli in healthy and ill neonate brains. The method could lead to clinical application in intra-ventricular hemorrhage (IVH) diagnosis along with other techniques such as EEG. We propose a realistic head model creation with all useful head structures and brain tissues including the neonate fontanel for more accurate results from NIRS signals modeling. We also design a 3D imaging tool for dynamic mapping and analysis of brain activation onto the cortex surface. Results show significant differences in oxy-hemoglobin between healthy neonates and subjects with IVH.

  5. Location Estimation using Delayed Measurements

    DEFF Research Database (Denmark)

    Bak, Martin; Larsen, Thomas Dall; Nørgård, Peter Magnus

    1998-01-01

    When combining data from various sensors it is vital to acknowledge possible measurement delays. Furthermore, the sensor fusion algorithm, often a Kalman filter, should be modified in order to handle the delay. The paper examines different possibilities for handling delays and applies a new techn...... technique to a sensor fusion system for estimating the location of an autonomous guided vehicle. The system fuses encoder and vision measurements in an extended Kalman filter. Results from experiments in a real environment are reported......When combining data from various sensors it is vital to acknowledge possible measurement delays. Furthermore, the sensor fusion algorithm, often a Kalman filter, should be modified in order to handle the delay. The paper examines different possibilities for handling delays and applies a new...

  6. Control systems with network delay

    OpenAIRE

    Şabanoviç, Asif; Sabanovic, Asif; Ohnishi, Kouhei; Yashiro, Daisuke; Acer, Merve; Ş.-Behliloviç, Nadira; S.-Behlilovic, Nadira

    2009-01-01

    In this paper motion control systems with delay in measurement and control channels are discussed and a new structure of the observer-predictor is proposed. The feature of the proposed system is enforcement of the convergence in both the estimation and the prediction of the plant output in the presence of the variable, unknown delay in both measurement and in the control channels. The estimation is based on the available data – undelayed control input, the delayed measurement of position o...

  7. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    International Nuclear Information System (INIS)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William; Bennett, Matthew R.; Josić, Krešimir

    2014-01-01

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay

  8. Modeling delay in genetic networks: from delay birth-death processes to delay stochastic differential equations.

    Science.gov (United States)

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Bennett, Matthew R; Josić, Krešimir; Ott, William

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  9. PRECISION TIME-DELAY CIRCUIT

    Science.gov (United States)

    Creveling, R.

    1959-03-17

    A tine-delay circuit which produces a delay time in d. The circuit a capacitor, an te back resistance, connected serially with the anode of the diode going to ground. At the start of the time delay a negative stepfunction is applied to the series circuit and initiates a half-cycle transient oscillatory voltage terminated by a transient oscillatory voltage of substantially higher frequency. The output of the delay circuit is taken at the junction of the inductor and diode where a sudden voltage rise appears after the initiation of the higher frequency transient oscillations.

  10. Systematic of delayed neutron parameters

    International Nuclear Information System (INIS)

    Isaev, S.G.; Piksaikin, V.M.

    2000-01-01

    The experimental studies of the energy dependence of the delayed neutron (DN) parameters for various fission systems has shown that the behaviour of a some combination of delayed neutron parameters has a similar features. On the basis of this findings the systematics of delayed neutron experimental data for thorium, uranium, plutonium and americium isotopes have been investigated with the purpose to find a correlation of DN parameters with characteristics of fissioning system as well as a correlation between the delayed neutron parameters themselves. It was presented the preliminary results which were obtained during study the physics interpretation of the results [ru

  11. Time Delay of CGM Sensors

    Science.gov (United States)

    Schmelzeisen-Redeker, Günther; Schoemaker, Michael; Kirchsteiger, Harald; Freckmann, Guido; Heinemann, Lutz; del Re, Luigi

    2015-01-01

    Background: Continuous glucose monitoring (CGM) is a powerful tool to support the optimization of glucose control of patients with diabetes. However, CGM systems measure glucose in interstitial fluid but not in blood. Rapid changes in one compartment are not accompanied by similar changes in the other, but follow with some delay. Such time delays hamper detection of, for example, hypoglycemic events. Our aim is to discuss the causes and extent of time delays and approaches to compensate for these. Methods: CGM data were obtained in a clinical study with 37 patients with a prototype glucose sensor. The study was divided into 5 phases over 2 years. In all, 8 patients participated in 2 phases separated by 8 months. A total number of 108 CGM data sets including raw signals were used for data analysis and were processed by statistical methods to obtain estimates of the time delay. Results: Overall mean (SD) time delay of the raw signals with respect to blood glucose was 9.5 (3.7) min, median was 9 min (interquartile range 4 min). Analysis of time delays observed in the same patients separated by 8 months suggests a patient dependent delay. No significant correlation was observed between delay and anamnestic or anthropometric data. The use of a prediction algorithm reduced the delay by 4 minutes on average. Conclusions: Prediction algorithms should be used to provide real-time CGM readings more consistent with simultaneous measurements by SMBG. Patient specificity may play an important role in improving prediction quality. PMID:26243773

  12. Ranking of Delay Factors for Makkah’s Construction Industry

    Directory of Open Access Journals (Sweden)

    Al-Emad Nashwan

    2017-01-01

    Full Text Available This paper presents identification of significant delay factors encountered by Makkah’s construction industry using quantitative approach. A structured questionnaire developed based on literature review was verified through pilot study involved selected construction experts. Questionnaire survey was conducted amongst Makkah construction practitioners include contractors, consultants and project management consultancy. The survey managed to collect 100 valid responses which were used to rank the factors using average index approach. Results of the analysis for 10 most significant factors causing construction delay in Makkah construction industry are Difficulties in financing project by contractor, Poor coordination between parties, Shortage of manpower, Delays in producing design documents, Improper planning and scheduling of the project, Delay in progress payments, Low productivity level of labour, Poor communication between parties, Unqualified workforce and Poor contract management. This finding is helpful to Makkah construction’s community particularly projects’ stakeholders in avoiding potential delay for their future projects.

  13. Finding determinants of audit delay by pooled OLS regression analysis

    Directory of Open Access Journals (Sweden)

    Tina Vuko

    2014-03-01

    Full Text Available The aim of this paper is to investigate determinants of audit delay. Audit delay is measured as the length of time (i.e. the number of calendar days from the fiscal year-end to the audit report date. It is important to understand factors that influence audit delay since it directly affects the timeliness of financial reporting. The research is conducted on a sample of Croatian listed companies, covering the period of four years (from 2008 to 2011. We use pooled OLS regression analysis, modelling audit delay as a function of the following explanatory variables: audit firm type, audit opinion, profitability, leverage, inventory and receivables to total assets, absolute value of total accruals, company size and audit committee existence. Our results indicate that audit committee existence, profitability and leverage are statistically significant determinants of audit delay in Croatia.

  14. High resolution digital delay timer

    Science.gov (United States)

    Martin, Albert D.

    1988-01-01

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay (20) provides a first output signal (24) at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits (26, 28) latch the high resolution data (24) to form a first synchronizing data set (60). A selected time interval has been preset to internal counters (142, 146, 154) and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses (32, 34) count down the counters to generate an internal pulse delayed by an interval which is functionally related to the preset time interval. A second LCD (184) corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD (74) to generate a second set of synchronizing data (76) which is complementary with the first set of synchronizing data (60) for presentation to logic circuits (64). The logic circuits (64) further delay the internal output signal (72) to obtain a proper phase relationship of an output signal (80) with the internal pulses (32, 34). The final delayed output signal (80) thereafter enables the output pulse generator (82) to produce the desired output pulse (84) at the preset time delay interval following input of the trigger pulse (10, 12).

  15. System delays in breast cancer

    African Journals Online (AJOL)

    we notice a discrepancy in incidence rates between various ethnic/race .... Thailand. 180. 2. 3. 5 to diagnosis NOT treatment‡. This study. South Africa 45. -. 2.5. 3. 1.25. 3. -. 10. *Total delay refers to totals for available datasets and not necessarily mean delay to treatment/surgery commencement. †Montella et al. presented ...

  16. Magnetic bearing optical delay line

    NARCIS (Netherlands)

    Dool, T.C. van den; Kamphues, F.G.; Fouss, B.; Henrioulle, K.; Hogenhuis, H.

    2004-01-01

    TNO TPD, in close cooperation with Micromega-Dynamics and Dutch Space, has developed an advanced Optical Delay Line (ODL) for use in PRIMA, GENIE and other ground based interferometers. The delay line design is modular and flexible, which makes scaling for other applications a relatively easy task.

  17. #FakeNobelDelayReasons

    CERN Multimedia

    2013-01-01

    Tuesday’s hour-long delay of the Nobel Prize in Physics announcement was (and still is) quite the cause for speculation. But on the Twittersphere, it was simply the catalyst for some fantastic puns, so-bad-they're-good physics jokes and other shenanigans. Here are some of our favourite #FakeNobelDelayReasons.    

  18. Picosecond resolution programmable delay line

    International Nuclear Information System (INIS)

    Suchenek, Mariusz

    2009-01-01

    The note presents implementation of a programmable delay line for digital signals. The tested circuit has a subnanosecond delay range programmable with a resolution of picoseconds. Implementation of the circuit was based on low-cost components, easily available on the market. (technical design note)

  19. Project delay analysis of HRSG

    Science.gov (United States)

    Silvianita; Novega, A. S.; Rosyid, D. M.; Suntoyo

    2017-08-01

    Completion of HRSG (Heat Recovery Steam Generator) fabrication project sometimes is not sufficient with the targeted time written on the contract. The delay on fabrication process can cause some disadvantages for fabricator, including forfeit payment, delay on HRSG construction process up until HRSG trials delay. In this paper, the author is using semi quantitative on HRSG pressure part fabrication delay with configuration plant 1 GT (Gas Turbine) + 1 HRSG + 1 STG (Steam Turbine Generator) using bow-tie analysis method. Bow-tie analysis method is a combination from FTA (Fault tree analysis) and ETA (Event tree analysis) to develop the risk matrix of HRSG. The result from FTA analysis is use as a threat for preventive measure. The result from ETA analysis is use as impact from fabrication delay.

  20. Delay discounting of different commodities.

    Science.gov (United States)

    Weatherly, Jeffrey N; Terrell, Heather K; Derenne, Adam

    2010-01-01

    When outcomes are delayed, their value is decreased. Delay discounting is a much-studied topic because it is correlated with certain disorders (e.g., pathological gambling). The present study attempts to determine how people would delay discount a number of different commodities, ranging from money to dating partners to federal education legislation. Participants completed delay discounting tasks pertaining to 5 different commodities, with a different set of 5 commodities for 2 groups. Results showed that different commodities were often discounted differently. Both data sets were also subjected to factor analysis. A 2-factor solution was found for both, suggesting that there are multiple "domains" of commodities. This finding is of interest because it suggests that measuring delay discounting for one commodity within a particular domain of commodities will be predictive of how people discount other commodities within that domain but will not be predictive of how they discount commodities within another domain.

  1. Differentiating phase shift and delay in narrow band coherent signals.

    Science.gov (United States)

    Muthuraman, M; Govindan, R B; Deuschl, G; Heute, U; Raethjen, J

    2008-05-01

    Differentiating between a fixed activation pattern (phase shift) and conduction time (time delay) in rhythmic signals has important physiological implications but is methodologically difficult. Delay was estimated by the maximising coherence method and phase spectra calculated between (i) a narrow band-pass filtered AR2 process and its delayed copy for different phase shifts, (ii) the surface EMGs from two antagonistic forearm muscles with reciprocal alternating activity, and (iii) EEG and EMG data from 11 recordings in five Parkinsonian tremor patients. Estimated delays between the versions of the AR2 process resembled the real delay and were not significantly biased by the phase-shifts. The reciprocal alternating pattern of muscle activation was shown to be a pure phase-shift without any time delay. The phase between tremor-coherent cortical electrodes and EMG showed opposite signs and differed by 3pi/4-pi between the antagonistic muscles. Bidirectional delays between contralateral cortex and EMG did not differ between the antagonists and were in keeping with fast corticospinal transmission and feedback to the cortex for both muscles. Phase shifts and delays reflect different mechanisms in tremor related oscillatory interactions. The maximising coherence method can differentiate between them.

  2. Delay in the diagnosis of cancer

    DEFF Research Database (Denmark)

    Hansen, Rikke Pilegaard

    This PhD thesis is based on the project "Cancer in general practice" conducted from 2004 to 2005 in the County of Aarhus, Denmark. The thesis is based on four articles and focuses on delay in the diagnosis of cancer in an established cohort of newly diagnosed cancer patients. The composite nature...... reports that old age, patient symptom reactions in the form of active seeking of information and support, as well as the active supportive behaviour of partners were important predictors of short patient delays, while patient tendencies to respond to threatening stimuli with emotional control and avoidant....... It is concluded that the study design may, to some extent, have given rise to selection and information bias and a risk of confounding, which, however, was largely accounted for in the analyses. We found a wide generalizability, although differences in health care systems regarding financing, degree...

  3. Finding determinants of audit delay by pooled OLS regression analysis

    OpenAIRE

    Vuko, Tina; Čular, Marko

    2014-01-01

    The aim of this paper is to investigate determinants of audit delay. Audit delay is measured as the length of time (i.e. the number of calendar days) from the fiscal year-end to the audit report date. It is important to understand factors that influence audit delay since it directly affects the timeliness of financial reporting. The research is conducted on a sample of Croatian listed companies, covering the period of four years (from 2008 to 2011). We use pooled OLS regression analysis, mode...

  4. Delayed umbilical cord clamping after childbirth: potential benefits to baby's health

    Directory of Open Access Journals (Sweden)

    Uwins C

    2014-11-01

    Full Text Available Christina Uwins,1 David JR Hutchon2 1Department of Obstetrics and Gynaecology, Croydon University Hospital, Croydon, 2Department of Obstetrics, Darlington Memorial Hospital, Darlington, UKAbstract: Early cord clamping was initially introduced as part of the package of care known as “active management of the third stage”, which was implemented to reduce postpartum hemorrhage. It has now been shown to provide no benefit to the mother and to result in harm to the neonate. The clinical trial evidence relating to delayed cord clamping compared to immediate cord clamping is presented and the physiological rationale for delayed cord clamping is discussed in this paper. Most organizations (eg World Health Organization (WHO, Royal College of Obstetricians and Gynaecologists (RCOG, Resuscitation Council (UK,The International Federation of Gynecology and Obstetrics (FIGO, International Confederation of Midwives, International Liaison Committee on Resuscitation (ILCOR and the European Resuscitation Council now advise a delay of 1–3 minutes before clamping the cord in term and preterm infants, and clinicians need to be aware of this change. Healthy neonates benefit from a more physiological and gentle transition from placental to pulmonary respiration, and we explain why this benefit should be provided to all neonates until there is any evidence to the contrary. The harm of early cord clamping is not limited to anemia and iron deficiency, and evidence for a wide range of possible harms of early cord clamping is presented. The need for resuscitation is one of the most common concerns, and ways of overcoming these concerns are described.Keywords: transition, cord clamping, hypovolemia, intraventricular hemorrhage

  5. Prevalence and determinants of delay in diagnosis of pulmonary tuberculosis in Darjeeling district of West Bengal

    Directory of Open Access Journals (Sweden)

    Sibasis Das

    2017-01-01

    Full Text Available Background: Delayed diagnosis of tuberculosis (TB is a significant problem both in individual as well as community level. Different studies around globe revealed that these diagnostic delays are attributed to both patient delay and health system-related delay. Aims: This study aims to assess the magnitude of delay in diagnosis and the association with sociodemographic profile among new sputum-positive pulmonary TB patients in Darjeeling district. Materials and Methods: A cross-sectional study was conducted among 374 TB patients from October 2011 to March 2012 using a predesigned pretested schedule by face-to-face interview. Statistical Analysis: Logistic regression analysis, odds ratios (OR, adjusted ORs. Results: Patient delay, health system delay and total diagnostic delay were 27 days, 20.1 days, and 20.6 days; mean delays were 23.64, 5.71, and 29.46 days, and median delays were 25, 5, and 32 days, respectively. Risk factors associated with patient delay were female gender, rural residence, illiteracy, smoking, alcohol consumption, taking two, or more alternate treatments; for health system delay were female sex, rural residence, time to reach health facility, time spent per visit; and for total diagnostic delay were female sex, alcoholism, and seeking more than two alternate treatment. Conclusions: The risk factors for delay identified may be the subject of future interventions.

  6. Fractional delayed damped Mathieu equation

    Science.gov (United States)

    Mesbahi, Afshin; Haeri, Mohammad; Nazari, Morad; Butcher, Eric A.

    2015-03-01

    This paper investigates the dynamical behaviour of the fractional delayed damped Mathieu equation. This system includes three different phenomena (fractional order, time delay, parametric resonance). The method of harmonic balance is employed to achieve approximate expressions for the transition curves in the parameter plane. The n = 0 and n = 1 transition curves (both lower and higher order approximations) are obtained. The dependencies of these curves on the system parameters and fractional orders are determined. Previous results for the transition curves reported for the damped Mathieu equation, delayed second-order oscillator, and fractional Mathieu equation are confirmed as special cases of the results for the current system.

  7. Ergodic Interference Alignment with Delayed Feedback

    OpenAIRE

    Kang, Myung Gil; Choi, Wan

    2013-01-01

    We propose new ergodic interference alignment techniques for $K$-user interference channels with delayed feedback. Two delayed feedback scenarios are considered -- delayed channel information at transmitter (CIT) and delayed output feedback. It is proved that the proposed techniques achieve total $2K/(K+2)$ DoF which is higher than that by the retrospective interference alignment for the delayed feedback scenarios.

  8. Fractional variational principles with delay

    International Nuclear Information System (INIS)

    Baleanu, Dumitru; Abdeljawad, Thabet Maaraba; Jarad, Fahd

    2008-01-01

    The fractional variational principles within Riemann-Liouville fractional derivatives in the presence of delay are analyzed. The corresponding Euler-Lagrange equations are obtained and one example is analyzed in detail

  9. Linear rotary optical delay lines

    Science.gov (United States)

    Guerboukha, Hichem; Qu, Hang; Skorobogatiy, Maksim

    2016-03-01

    We present a semi-analytical solution for the design of a high-speed rotary optical delay line that use a combination of two rotating curvilinear reflectors. We demonstrate that it is possible to design an infinite variety of the optical delay lines featuring linear dependence of the optical delay on the rotation angle. This is achieved via shape optimization of the rotating reflector surfaces. Moreover, a convenient spatial separation of the incoming and outgoing beams is possible. For the sake of example, we present blades that fit into a circle of 10cm diameter. Finally, a prototype of a rotary delay line is fabricated using CNC machining, and its optical properties are characterized.

  10. Delays and networked control systems

    CERN Document Server

    Hetel, Laurentiu; Daafouz, Jamal; Johansson, Karl

    2016-01-01

    This edited monograph includes state-of-the-art contributions on continuous time dynamical networks with delays. The book is divided into four parts. The first part presents tools and methods for the analysis of time-delay systems with a particular attention on control problems of large scale or infinite-dimensional systems with delays. The second part of the book is dedicated to the use of time-delay models for the analysis and design of Networked Control Systems. The third part of the book focuses on the analysis and design of systems with asynchronous sampling intervals which occur in Networked Control Systems. The last part of the book exposes several contributions dealing with the design of cooperative control and observation laws for networked control systems. The target audience primarily comprises researchers and experts in the field of control theory, but the book may also be beneficial for graduate students. .

  11. Intraventricular injection of 6-hydroxydopamine results in an increased number of tyrosine hydroxylase immune-positive cells in the rat cortex.

    Science.gov (United States)

    Wachter, B; Caradonna, S; Gittinger, K; Schläger, A; Küppers, E

    2014-11-07

    Previously we have demonstrated that intraventricular injection of 6-hydroxydopamine (6-OHDA) results in increased proliferation and de-differentiation of rat cortical astrocytes into progenitor-like cells 4 days after lesion (Wachter et al., 2010). To find out if these cells express tyrosine hydroxylase (TH), the rate-limiting enzyme in the catecholamine synthesis pathway, we performed immunohistochemistry in the rat cortex following intraventricular injection of 6-OHDA. Four days after injection we demonstrated a strong emergence of TH-positive (TH(+)) somata in the cortices of 6-OHDA-lesioned animals. The number of TH(+) cells in the cortex of 6-OHDA-lesioned animals was 15 times higher than in sham-operated animals, where virtually no TH(+) somata occurred. Combining TH immunohistochemistry with classical Nissl stain yielded complete congruency, and ∼45% of the TH(+) cells co-expressed calretinin, which indicates an interneuron affiliation. There was no co-staining of TH with other interneuron markers or with glial markers such as glial fibrillary acidic protein (GFAP) or the neural stem/progenitor marker Nestin, nor could we find co-localization with the proliferation marker Ki67. However, we found a co-localization of TH with glial progenitor cell markers (Sox2 and S100β) and with polysialylated-neural cell adhesion molecule (PSA-NCAM), which has been shown to be expressed in immature, but not recently generated cortical neurons. Taken together, this study seems to confirm our previous findings with respect to a 6-OHDA-induced expression of neuronal precursor markers in cells of the rat cortex, although the TH(+) cells found in this study are not identical with the potentially de-differentiated astrocytes described recently (Wachter et al., 2010). The detection of cortical cells expressing the catecholaminergic key enzyme TH might indicate a possible compensatory role of these cells in a dopamine-(DA)-depleted system. Future studies are needed to determine

  12. Systematics in delayed neutron yields

    Energy Technology Data Exchange (ETDEWEB)

    Ohsawa, Takaaki [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.

    1998-03-01

    An attempt was made to reproduce the systematic trend observed in the delayed neutron yields for actinides on the basis of the five-Gaussian representation of the fission yield together with available data sets for delayed neutron emission probability. It was found that systematic decrease in DNY for heavier actinides is mainly due to decrease of fission yields of precursors in the lighter side of the light fragment region. (author)

  13. Analytical applications for delayed neutrons

    International Nuclear Information System (INIS)

    Eccleston, G.W.

    1983-01-01

    Analytical formulations that describe the time dependence of neutron populations in nuclear materials contain delayed-neutron dependent terms. These terms are important because the delayed neutrons, even though their yields in fission are small, permit control of the fission chain reaction process. Analytical applications that use delayed neutrons range from simple problems that can be solved with the point reactor kinetics equations to complex problems that can only be solved with large codes that couple fluid calculations with the neutron dynamics. Reactor safety codes, such as SIMMER, model transients of the entire reactor core using coupled space-time neutronics and comprehensive thermal-fluid dynamics. Nondestructive delayed-neutron assay instruments are designed and modeled using a three-dimensional continuous-energy Monte Carlo code. Calculations on high-burnup spent fuels and other materials that contain a mix of uranium and plutonium isotopes require accurate and complete information on the delayed-neutron periods, yields, and energy spectra. A continuing need exists for delayed-neutron parameters for all the fissioning isotopes

  14. DRAWING SKILLS IN CHILDREN WITH NEURODEVELOPMENTAL DELAY AGED 2-5 YEARS.

    Science.gov (United States)

    Morović, Maja Lang; Matijević, Valentina; Divljaković, Kristina; Kraljević, Marija; Dimić, Zdenka

    2015-06-01

    In typically developing children, drawing development occurs in stages from uncontrolled strokes to complex drawing. In this study, we examined drawing development in children with neurodevelopmental delay (NDD). In order to do so, we observed the influence of age, intraventricular hemorrhage (IVH) and gender on the development of drawing skills. The sample consisted of 52 children with NDD, aged 2 years and 6 months to 5 years. All children were hospitalized for multidisciplinary team monitoring and developmental support. The evaluation of drawing development was administered by giving each child a blank A4 paper and the instruction to draw anything they wanted. All of the drawings were scored satisfactory or unsatisfactory. Descriptive statistics was employed on all relevant data to show results in frequencies and percentages. In order to determine differences between groups, the χ2-test was administered. The results showed greatest difference in drawing in children aged from 3 years to 3 years and 11 months. Children with lower IVH had better drawing scores than children with higher IVH levels. According to gender dissimilarities, a difference was found showing girls to have better drawing skills than boys. All study results pointed to the importance of early rehabilitation and continuous structured work with children with NDD.

  15. Language Delays in Toddlers: Information for Parents

    Science.gov (United States)

    ... Stages Listen Español Text Size Email Print Share Language Delays in Toddlers: Information for Parents Page Content ... situation or repeats scripts from TV Delays in language Delays in language are the most common types ...

  16. Changes in intraventricular septal thickness, left ventrical wall thickness and left ventricular volume in obese adolescents on a high protein weight reducing diet.

    Science.gov (United States)

    Archibald, E H; Stallings, V A; Pencharz, P B; Duncan, W J; Williams, C

    1989-01-01

    Ten obese adolescents (153 percent ideal body weight) underwent significant weight reduction over a two to three month period using a low calorie, low carbohydrate, protein diet. The subjects lost a mean of 13.9 +/- 4.3 kg, representing a decrease of 15.5 +/- 5.0 percent of initial body weight. Serial measures of intraventricular septal thickness (ST), left ventricular wall thickness (LVWT) and left ventricular volume (LVV) were determined by standard m-mode echocardiographic methods over 14 weeks to determine the effect of weight reduction on these indicators of cardiac size. The ST changed over the study period from 8.2 +/- 1.9 mm to 7.3 +/- 2.0 mm; the LVWT from 7.6 +/- 1.8 mm to 6.3 +/- 1.1 mm; and the LVV from 47.1 +/- 4.0 mm to 42.0 +/- 2.8 mm. These numerical decreases were not significantly different. Over this study period, the diet allowed weight loss with no apparent effect on the cardiac size (ST, LVWT, LVV) as measured by echocardiography in these obese adolescents.

  17. Delays and user performance in human-computer-network interaction tasks.

    Science.gov (United States)

    Caldwell, Barrett S; Wang, Enlie

    2009-12-01

    This article describes a series of studies conducted to examine factors affecting user perceptions, responses, and tolerance for network-based computer delays affecting distributed human-computer-network interaction (HCNI) tasks. HCNI tasks, even with increasing computing and network bandwidth capabilities, are still affected by human perceptions of delay and appropriate waiting times for information flow latencies. Conducted were 6 laboratory studies with university participants in China (Preliminary Experiments 1 through 3) and the United States (Experiments 4 through 6) to examine users' perceptions of elapsed time, effect of perceived network task performance partners on delay tolerance, and expectations of appropriate delays based on task, situation, and network conditions. Results across the six experiments indicate that users' delay tolerance and estimated delay were affected by multiple task and expectation factors, including task complexity and importance, situation urgency and time availability, file size, and network bandwidth capacity. Results also suggest a range of user strategies for incorporating delay tolerance in task planning and performance. HCNI user experience is influenced by combinations of task requirements, constraints, and understandings of system performance; tolerance is a nonlinear function of time constraint ratios or decay. Appropriate user interface tools providing delay feedback information can help modify user expectations and delay tolerance. These tools are especially valuable when delay conditions exceed a few seconds or when task constraints and system demands are high. Interface designs for HCNI tasks should consider assistant-style presentations of delay feedback, information freshness, and network characteristics. Assistants should also gather awareness of user time constraints.

  18. UWB delay and multiply receiver

    Energy Technology Data Exchange (ETDEWEB)

    Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Romero, Carlos E.

    2013-09-10

    An ultra-wideband (UWB) delay and multiply receiver is formed of a receive antenna; a variable gain attenuator connected to the receive antenna; a signal splitter connected to the variable gain attenuator; a multiplier having one input connected to an undelayed signal from the signal splitter and another input connected to a delayed signal from the signal splitter, the delay between the splitter signals being equal to the spacing between pulses from a transmitter whose pulses are being received by the receive antenna; a peak detection circuit connected to the output of the multiplier and connected to the variable gain attenuator to control the variable gain attenuator to maintain a constant amplitude output from the multiplier; and a digital output circuit connected to the output of the multiplier.

  19. Time delay in quantum scattering

    International Nuclear Information System (INIS)

    Tee, R.G.

    1978-01-01

    As is well known, the knowledge of the scattering cross section and its angular dependence, as a function of energy, is insufficient to determine the phase shifts uniquely. This led Eisenbud and Wigner to propose the measurement of the scattering lifetime or time delay as an additional independent datum. A rigorous time-dependent study of time delay within the framework of Hilbert space formalism is presented. Specifically, Martin's theory of time delay and the validity of the Eisenbud-Wigner time delay formula are extended to spherically symmetric potentials satisfying the asymptotic fall-off rate V(r) → O(r/sup -2-epsilon/). This extension is obtained by use of a maximal estimate of the rate of convergence of the asymptotic condition and the elimination of Martin's requirement that the scattering operator S be three times differentiable with respect to the free-particle Hamiltonian H 0 . Also presented are related results on the total time a quantum particle spends inside some bounded regions in position space. It is then proved that any two free particles having identical distributions of energy and angular momentum take exactly identical expectation values for the transit time across an arbitrary spherical region centered at the origin in position space. Ways to extend this result to nonfree Hamiltonians are indicated. Finally, the relationship between the position operator and the Eisenbud-Wigner time delay operator is examined. It is shown that the usual method of calculating time delay based on the classical analysis of the position operator is not exact

  20. Stochastic modelling of train delays and delay propagation in stations

    NARCIS (Netherlands)

    Yuan, J.

    2006-01-01

    A trade-off exists between efficiently utilizing the capacity of railway networks and improving the reliability and punctuality of train operations. This dissertation presents a new analytical probability model based on blocking time theory which estimates the knock-on delays of trains caused by

  1. 49 CFR 236.563 - Delay time.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

  2. EAMJ Delayed April 10.indd

    African Journals Online (AJOL)

    2010-04-04

    Apr 4, 2010 ... and Director, Kenyatta National Hospital, P.O. Box 19961-00202, Nairobi, Kenya, S.K. Kimende, MBChB, MMed (Surg.) Lecturer, Department of Surgery, ... For purposes of management, breast cancer is clinically divided into early .... delays inherent in out healthcare systems (18,19). Indeed, one of the most ...

  3. Early-delayed radiation rhombencephalopathy

    International Nuclear Information System (INIS)

    Nightingale, S.; Dawes, P.J.D.K.; Cartlidge, N.E.F.; Newcastle upon Tyne Univ.

    1982-01-01

    A 37-year-old woman developed an early-delayed rhombencephalopathy 7 weeks after completing a course of radiotherapy to a glomus jugulare tumour. The clinical features, comprising nystagmus, skew strabismus, unilateral facial weakness, dysarthria and ataxia, are compared with four previously reported patients with this syndrome. (author)

  4. Advanced optical delay line demonstrator

    NARCIS (Netherlands)

    Dool, T.C. van den; Kamphues, F.G.; Fouss, B.; Henrioulle, K.; Hogenhuis, H.

    2004-01-01

    TNO TPD, in cooperation with Micromega-Dynamics and Dutch Space, has designed an advanced Optical Delay Line (ODL) for use in future ground based and space interferometry missions. The work is performed under NIVR contract in preparation for GENIE and DARWIN. Using the ESO PRIMA DDL requirements as

  5. Diagnostic Delay in Rheumatoid Arthritis

    DEFF Research Database (Denmark)

    Mølbaek, Karen; Hørslev-Petersen, Kim; Primdahl, Jette

    2016-01-01

    to approach their general practitioner (GP) with joint pain, and also how GPs respond to patients' complaints. METHODS: The study was based on qualitative data collected using 11 semi-structured individual interviews. RESULTS: When symptoms were obvious to patients, there was a shorter delay between symptom...

  6. Livermore blasted for project delay

    CERN Multimedia

    1999-01-01

    In a 12 page report issued last week, a review committee set up by the University of California has concluded that mismanagement and poor planning are to blame for significant cost overruns and delays in the construction of NIF, the worlds largest laser (1 page).

  7. Weather delay costs to trucking.

    Science.gov (United States)

    2012-11-01

    Estimates of the nations freight sector of transportation range to upwards of $600 billion of total gross domestic product with 70 percent of total value and 60 percent of total weight moving by truck. Weather-related delays can add significantly ...

  8. Another definition for time delay

    International Nuclear Information System (INIS)

    Narnhofer, H.

    1980-01-01

    Time delay is defined by geometrical considerations which work in classical as well as in quantum mechanics, and its connection with the S-matrix and the virial is proven for potentials with V(x vector) and x vector V(x vector) vanishing as rsup(-1-epsilon) for r -> infinity. (Author)

  9. Early-delayed radiation rhombencephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Nightingale, S.; Dawes, P.J.D.K.; Cartlidge, N.E.F. (Royal Victoria Infirmary, Newcastle upon Tyne (UK); Newcastle upon Tyne Univ. (UK). Newcastle General Hospital)

    1982-03-01

    A 37-year-old woman developed an early-delayed rhombencephalopathy 7 weeks after completing a course of radiotherapy to a glomus jugulare tumour. The clinical features, comprising nystagmus, skew strabismus, unilateral facial weakness, dysarthria and ataxia, are compared with four previously reported patients with this syndrome.

  10. Delayed School Entry in Uganda

    Science.gov (United States)

    Moyi, Peter

    2011-01-01

    Since 1997 Uganda has seen a large increase in school enrolment. Despite this increased enrolment, universal education has remained elusive. Many children enrol in school, but not at the recommended age, and they drop out before completing school. This article focuses on one of these problems--delayed school entry. What household factors are…

  11. Providing delay guarantees in Bluetooth

    NARCIS (Netherlands)

    Ait Yaiz, R.; Heijenk, Geert; Titsworth, F.

    2003-01-01

    Bluetooth polling, also referred to as Bluetooth MAC scheduling or intra-piconet scheduling, is the mechanism that schedules the traffic between the participants in a Bluetooth network. Hence, this mechanism is highly determining with respect to the delay packets experience in a Bluetooth network.

  12. The Effect of Head Positioning and Head Tilting on the Incidence of Intraventricular Hemorrhage in Very Preterm Infants: A Systematic Review.

    Science.gov (United States)

    de Bijl-Marcus, Karen A; Brouwer, Annemieke J; de Vries, Linda S; van Wezel-Meijler, Gerda

    2017-01-01

    Despite advances in neonatal intensive care, germinal matrix-intraventricular hemorrhage (GMH-IVH) remains a frequent, serious complication of premature birth. Neutral head position and head tilting have been suggested to reduce the risk of GMH-IVH in preterm infants during the first 72 h of life. The aim of this study was to provide a systematic review of the effect of neutral head positioning and head tilting on the incidence of GMH-IVH in very preterm infants (gestational age ≤30 weeks). In addition, we reviewed their effect on cerebral hemodynamics and oxygenation. Literature was searched (June 2016) in the following electronic databases: CINAHL, Embase, Medline, SCOPUS, and several trial registers. One underpowered trial studied the effect of head positioning on the incidence of GMH-IVH. This randomized controlled trial enrolled 48 preterm infants and found no effect on the occurrence of GMH-IVH. Three observational studies investigated the effect of head rotation and/or tilting on cerebral oxygenation in 68 preterm infants in total. Their results suggest that cerebral oxygenation is not significantly affected by changes in head positioning. The effect of head positioning and/or tilting on cerebral hemodynamics was described in 2 observational studies of 28 preterm infants and found no significant effect. There is insufficient evidence regarding the effect of head positioning and tilting on the incidence of GMH-IVH and cerebral hemodynamics and oxygenation in preterm infants. We recommend further research in this field, especially in extremely preterm and clinically unstable infants during the first postnatal days. © 2016 S. Karger AG, Basel.

  13. Intraventricular cerebrospinal fluid temperature analysis using MR diffusion-weighted imaging thermometry in Parkinson's disease patients, multiple system atrophy patients, and healthy subjects.

    Science.gov (United States)

    Sumida, Kaoru; Sato, Noriko; Ota, Miho; Sakai, Koji; Nippashi, Yasumasa; Sone, Daichi; Yokoyama, Kota; Ito, Kimiteru; Maikusa, Norihide; Imabayashi, Etsuko; Matsuda, Hiroshi; Yamada, Kei; Murata, Miho; Kunimatsu, Akira; Ohtomo, Kuni

    2015-06-01

    We examined the temperature of the intraventricular cerebrospinal fluid (Tv) in patients with Parkinson's disease (PD) and those with multiple system atrophy (MSA) in comparison with healthy subjects, and we examined normal changes in this temperature with aging. Tv was estimated by magnetic resonance (MR) diffusion-weighted imaging (DWI) thermometry in 36 PD patients (19 males, 17 females), 34 MSA patients (17 males, 17 females), 64 age-matched controls (27 men, 37 women), and 114 all-age adult controls (47 men, 67 women; 28-89 years old). The volume of lateral ventricles was also estimated using FreeSurfer in all subjects. Tv and ventricular volume data were compared among the PD and MSA patients and age-matched controls. We also evaluated the relationship between Tv and age in the 114 all-age controls, controlling for ventricular volume. Men and women were analyzed separately. The male PD and MSA patients had significantly higher Tv values compared to the male controls, with no significant difference in ventricular volume among them. There was no significant difference in Tv between the female patients and controls. In the all-age male controls, there was a significant negative correlation between Tv and age controlling for ventricular volume, and this was not observed in the women. DWI thermometry is a useful and easy method for demonstrating an altered intracranial environment in male patients and healthy controls, but not in females. DWI thermometry can thus be used to help to explore the pathophysiology of Parkinsonian syndromes and to differentiate individuals affected by neurodegenerative disease with autonomic dysfunction from those without it.

  14. The effects of mild germinal matrix-intraventricular haemorrhage on the developmental white matter microstructure of preterm neonates: a DTI study.

    Science.gov (United States)

    Tortora, Domenico; Martinetti, Carola; Severino, Mariasavina; Uccella, Sara; Malova, Mariya; Parodi, Alessandro; Brera, Fabia; Morana, Giovanni; Ramenghi, Luca Antonio; Rossi, Andrea

    2018-03-01

    To evaluate white matter (WM) microstructural changes in preterm neonates (PN) with mild germinal matrix-intraventricular haemorrhage (mGMH-IVH) (grades I and II) and no other associated MRI abnormalities, and correlate them with gestational age (GA) and neurodevelopmental outcome. Tract-based spatial-statistics (TBSS) was performed on DTI of 103 patients studied at term-equivalent age, to compare diffusional parameters (fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD)) between mGMH-IVH neonates (24/103) and controls matched by GA at birth and sex. The relationship between DTI abnormalities, GA and neurodevelopmental outcome assessed with Griffiths' Developmental Scale-Revised:0-2 was explored using TBSS and Spearman-correlation analysis (p < .05). Affected neonates had lower FA, higher RD and MD of the corpus callosum, limbic pathways and cerebellar tracts. Extremely preterm neonates (GA < 29 weeks) presented more severe microstructural impairment (higher RD and MD) in periventricular regions. Neonates of GA ≥ 29 weeks had milder WM alterations (lower FA), also in subcortical WM. DTI abnormalities were associated with poorer locomotor, eye-hand coordination and performance outcomes at 24 months. WM microstructural changes occur in PN with mGMH-IVH with a GA-dependent selective vulnerability of WM regions, and correlate with adverse neurodevelopmental outcome at 24 months. • DTI-TBSS analysis identifies WM microstructural changes in preterm neonates with mGMH-IVH. • Extremely preterm neonates with mGMH-IVH presented more severe impairment of WM microstructure. • Extremely preterm neonates with mGMH-IVH presented microstructural impairment of periventricular WM. • mGMH-IVH affects subcortical WM in preterm neonates with gestational age ≥ 29 weeks. • WM microstructural alterations are related to neurodevelopmental impairments at 24 months.

  15. Risk Factors for Intraventricular Hemorrhage in Preterm Infants Born at 34 Weeks of Gestation or Less Following Preterm Premature Rupture of Membranes.

    Science.gov (United States)

    Lu, Hongyan; Wang, Qiuxia; Lu, Junyin; Zhang, Qiang; Kumar, Pravesh

    2016-04-01

    The objective of this study is to identify possible perinatal risk factors related to intraventricular hemorrhage (IVH) in preterm infants born at 34 weeks of gestation or less following preterm premature rupture of membranes (pPROM). A total of 292 preterm infants born at 34 weeks of gestation or less following pPROM were enrolled in the study, while 155 newborns with incomplete data, especially those that lack histological examination of the placenta, maternal details, and neonatal characteristics, have been further excluded. Finally, data of 137 preterm infants were included in the analysis. All infants underwent ultrasonographic screening for IVH. Thirty-three infants with IVH were considered as cases and 104 infants without IVH were considered as controls. The association between risk factors and IVH was evaluated by univariate and multivariate logistic regression analyses. The incidence of IVH in preterm infants born at 34 weeks of gestation or less following pPROM was 24.1%, while the incidence of maternal chorioamnionitis was 43.8%. By univariate analysis, gestational age, birth weight, asphyxia resuscitation, maternal chorioamnionitis, fetal distress, amniotic fluid index, and latency of the rupture of membranes to birth were found to be significantly different between the 2 groups. By logistic regression analysis, lower gestational age, low birth weight, asphyxia resuscitation, and maternal chorioamnionitis were found to be independent risk factors for IVH. Lower gestational age, low birth weight, asphyxia resuscitation, and maternal chorioamnionitis are independent risk factors for IVH in preterm infants born at 34 weeks of gestation or less following pPROM. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  16. Magnetic resonance imaging assessment of intraventricular dyssynchrony and delayed enhancement as predictors of response to cardiac resynchronization therapy in patients with heart failure of ischaemic and non-ischaemic etiologies

    Energy Technology Data Exchange (ETDEWEB)

    Petryka, Joanna, E-mail: joannapetryka@hotmail.com [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Miśko, Jolanta [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Radiology, Institute of Cardiology, Warsaw (Poland); Przybylski, Andrzej [Department of Arrhythmia, Institute of Cardiology, Warsaw (Poland); Śpiewak, Mateusz [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Małek, Łukasz A. [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Cardiology and Interventional Angiology, Institute of Cardiology, Warsaw (Poland); Werys, Konrad [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Mazurkiewicz, Łukasz [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Cardiomyopathy, Institute of Cardiology, Warsaw (Poland); Gepner, Katarzyna [Department of Coronary Artery Disease, Institute of Cardiology, Warsaw (Poland); Croisille, Pierre [Creatis Laboratory, UMR CNRS 5515, INSERM, U1044, CHU Saint-Etienne, Universite de Lyon (France); Demkow, Marcin [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Rużyłło, Witold [Institute of Cardiology, Warsaw (Poland)

    2012-10-15

    Purpose: To assess the value of dyssynchrony and myocardial viability assessment by cardiac magnetic resonance (CMR) in prediction of response to cardiac resynchronization therapy (CRT) in patients with heart failure (HF) of both ischaemic and non-ischaemic etiologies. Materials and methods: Patients scheduled for CRT in NYHA class II–IV, left ventricular ejection fraction <35%, QRS ≥ 120 ms were included. Tagged cine and late gadolinium enhancement (LGE) images were performed. Dyssynchrony was assessed with inTag toolbox and LGE was quantified using cutoff value at half of maximal signal in the scar. Cardiopulmonary exercise test, echocardiography and blood testing for NT-proBNP levels were done at baseline and 6 months after CRT. Results: 52 patients (age 60.3 ± 13 years) were included. 26 patients (50%) met response criteria. The ischaemic etiology of HF was more frequent (69% vs. 31%, p = 0.002), the percent of LGE was higher (7.7% [0–13.5%] vs. 19.0% (0–31.9%], p = 0.013), regional vector of circumferential strain variance (RVV) was lower (0.27 ± 0.08 vs. 0.34 ± 0.09, p = 0.009) and uniformity of radial strain was higher (0.72 ± 0.25 vs. 0.56 ± 0.29, p = 0.046) in non-responders vs. responders. Multivariate logistic regression showed that RVV predicted response to CRT (HR 2.3, 95% CI 1.02–5.02, p = 0.0430) independently of LGE and the etiology of heart failure. In the subgroup of patients with ischaemic HF the extend of transmural scar within myocardium was higher in non-responders vs. responders (26.3% vs. 15.0% respectively, p = 0.01) and was a predictor of response to CRT in univariable analysis (HR 0.87, 95% CI 0.77–0.98, p = 0.025) providing the sensitivity of 76% and specificity of 75% at the cutoff point of 18% in the prediction of poor response to CRT. In patients with non-ischaemic HF QRS was wider (162 ms vs. 140 ms, p = 0.04), regional vector of strain variance (RVV) was higher (0.39 vs. 0.25, p = 0.002) and uniformity of radial strain was lower (0.52 vs. 0.80, p = 0.049) in non-responders vs. responders. Univariable logistic regression showed that RVV was a predictor of response to CRT (HR 1.50, 95% CI 1.06–2.13, p = 0.022), providing the sensitivity of 94% and specificity of 85% at the cutoff point of 0.31. Conclusions: CMR derived parameters of dyssynchrony such as RVV may provide an additive value in prediction of response to CRT, especially in patients with non-ischaemic etiology of heart failure. In patients with ischaemic HF the transmurality of LGE is an important predictor of lack of response to CRT.

  17. Analysis of a first-order delay differential-delay equation containing two delays

    Science.gov (United States)

    Marriott, C.; Vallée, R.; Delisle, C.

    1989-09-01

    An experimental and numerical analysis of the behavior of a two-delay differential equation is presented. It is shown that much of the system's behavior can be related to the stability behavior of the underlying linearized modes. A new phenomenon, mode crossing, is explored.

  18. Internal mammary recipient site breast cancer recurrence following delayed microvascular breast reconstruction.

    Science.gov (United States)

    Rosich-Medina, Anais; Wang, Susan; Erel, Ertan; Malata, Charles M

    2013-01-01

    The internal mammary vessels are a popular recipient site for microsurgical anastomoses of free flap breast reconstructions. We, however, observed 3 patients undergoing internal mammary vessel delayed free flap breast reconstruction that subsequently developed tumor recurrence at this site. We reviewed their characteristics to determine whether there was a correlation between delayed microsurgical reconstruction and local recurrence. A retrospective review of a single surgeon's delayed free flap breast reconstructions using the internal mammary vessels was conducted over a 7-year period to identify the time intervals between mastectomy and delayed breast reconstruction and between delayed breast reconstruction and recurrence. Three patients developed local recurrence at the site of the microvascular anastomoses following delayed breast reconstruction. All patients had been disease-free following mastectomy. The median time interval between mastectomy and delayed breast reconstruction was 28 months (range = 20-120 months) while that between delayed breast reconstruction and local recurrence was 7 months (range = 4-10 months). Two patients died from metastatic disease, 36 and 72 months following their local recurrence. One patient remains alive 44 months after reconstruction. Local tumor recurrence at the internal mammary vessel dissection site following delayed breast reconstruction raises the question whether these 2 events may be related. Specifically, could internal mammary vessel dissection undertaken for delayed microsurgical reconstruction predispose to recurrence in the internal mammary lymph nodes? Further research is needed to ascertain whether delayed breast reconstruction increases the risk of local recurrence in this patient group.

  19. Incidence and risk factors of intraventricular hemorrhage in preterm newborns Evaluación de la incidencia y los factores de riesgo para hemorragia intraventricular (HIV en la cohorte de recién nacidos prematuros atendidos en la unidad neonatal del HUSVP, de Medellín, en el período comprendido entre ene. de 1999 y dic. de 2004

    Directory of Open Access Journals (Sweden)

    José William Cornejo Ochoa

    2007-12-01

    Full Text Available Introduction: intraventricular hemorrhage is the main neurological complication of preterm newborns. Its frequency and severity increase as gestational age and weight at birth decrease. Other factors have been described that may influence its incidence. Objective: to determine the incidence of intraventricular hemorrhage at the Neonatal Care Unit of the Hospital Universitario San Vicente de Paúl, in Medellín, Colombia, from 1999 to 2004, and to establish its association with maternal and newborn conditions. Results: an incidence of HIV of 29.8% was found. Cesarean section, labor in a third level attention center and pulmonary maturation were found to be protective factors. On the other hand, the incidence of HIV increased with the following circumstances: vaginal labor, gestational age under 28 weeks, use of surfactant, mechanical ventilation, acidosis, hypercapnia and umbilical catheterism. Conclusions: prenatal programs have to be reinforced in order to avoid preterm labor; high risk pregnant women ought to be opportunely referred to specialized centers; the antenatal use of steroids is to be encouraged and careful management of ventilatory parameters avoiding acidosis is mandatory. La hemorragia intraventricular (HIV es la principal complicación neurológica de los recién nacidos prematuros, cuyas frecuencia y gravedad aumentan con el menor peso al nacer y la menor edad gestacional. Se han encontrado otros factores asociados con el aumento o disminución de su frecuencia. Objetivo: determinar la incidencia de HIV en prematuros atendidos en el Hospital Universitario San Vicente de Paúl (HUSVP, de Medellín, Colombia, entre 1999 y 2004 y establecer su asociación con condiciones de la madre y del recién nacido. Metodología: estudio retrospectivo de los prematuros menores de 32 semanas y por debajo de 1.500 gramos, atendidos en el HUSVP entre 1999 y 2004. Se calculó una muestra de 330 historias clínicas, seleccionadas en forma aleatoria

  20. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-01-08

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  1. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-11-09

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  2. Reconfigurable Reduced Delay Universal Adder

    OpenAIRE

    Mohit Tyagi,; Samender Singh,; Kavita Khare

    2011-01-01

    This paper introduces a novel architecture for least latency universal adder using pipeline and parallel computing technique. The proposed architecture implemented in reconfigurable technology as arun time reconfigurable unit. The proposed 32-bit Universal adder design and compared with previously proposed adder designs in terms of area and delay after synthesis targeting on 4vfx60ff672-12 Xilinxvirtex-4 FPGA and have high hardware resource sharing up to 42% for the binary and BCD arithmetic ...

  3. [Determinants of induced abortion delay].

    Science.gov (United States)

    Font-Ribera, Laia; Pérez, Glòria; Espelt, Albert; Salvador, Joaquin; Borrell, Carme

    2009-01-01

    In induced abortion, the method, the risk of complications and the economic cost of the abortion are determined by gestational age. The aim of this study was to describe the determinants of induced abortion delay until the second trimester of pregnancy in Barcelona. We performed a cross-sectional study of induced abortions due to the physical or mental health of the woman (Barcelona, 2004-2005; N=9,175). The city's induced abortion register provided data on gestational age at abortion (dependent variable), educational level, age, cohabitation with the partner, number of children previous abortions, and type of center. Adjusted prevalence ratios (aPR) were calculated with log-binomial regression models. A total of 7.7% of induced abortions were second-trimester abortions and 99.3% were performed in private centers. Compared with women with a university education, those with primary education or less had an aPR of 1.8 (95% confidence interval [95%CI]: 1.4-2.2) of delaying the abortion until the second trimester. A higher proportion of second-trimester abortions were also recorded in women aged less than 18 years old (aPR=2.6; 95%CI: 2.0-3.4), women not cohabiting with their partners (aRP=1.4; 95% CI: 1.2-1.6) and in public centers (aPR=2.8; 95% CI: 2.2-3.7). No differences were found in induced abortion delay among women with previous abortions and those without. Induced abortion delay until the second trimester of pregnancy was associated with low educational level, young ages, not cohabiting with a partner, and public centers. This study demonstrates the existence of socioeconomic inequalities in access conditions to abortion services.

  4. Assembly delay line pulse generators

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    Assembly of six of the ten delay line pulse generators that will power the ten kicker magnet modules. One modulator part contains two pulse generators. Capacitors, inductances, and voltage dividers are in the oil tank on the left. Triggered high-pressure spark gap switches are on the platforms on the right. High voltage pulse cables to the kicker magnet emerge under the spark gaps. In the centre background are the assembled master gaps.

  5. Teriparatide Induced Delayed Persistent Hypercalcemia

    OpenAIRE

    Thiruchelvam, Nirosshan; Randhawa, Jaskirat; Sadiek, Happy; Kistangari, Gaurav

    2014-01-01

    Teriparatide, a recombinant PTH, is an anabolic treatment for osteoporosis that increases bone density. Transient hypercalcemia is a reported side effect of teriparatide that is seen few hours following administration of teriparatide and resolves usually within 16 hours of drug administration. Persistent hypercalcemia, although not observed in clinical trials, is rarely reported. The current case describes a rare complication of teriparatide induced delayed persistent hypercalcemia.

  6. Teriparatide Induced Delayed Persistent Hypercalcemia

    Directory of Open Access Journals (Sweden)

    Nirosshan Thiruchelvam

    2014-01-01

    Full Text Available Teriparatide, a recombinant PTH, is an anabolic treatment for osteoporosis that increases bone density. Transient hypercalcemia is a reported side effect of teriparatide that is seen few hours following administration of teriparatide and resolves usually within 16 hours of drug administration. Persistent hypercalcemia, although not observed in clinical trials, is rarely reported. The current case describes a rare complication of teriparatide induced delayed persistent hypercalcemia.

  7. ATLAS calibration delay chip study

    CERN Document Server

    Massol, N

    2003-01-01

    The delay chip is an ASIC developed to precisely adjust signals within the range of 0-24ns in steps of 1ns. In this note, we report the study of the characteristics of this chip like the linearity and the jitter. We describe the influence of temperature and supply voltage on its behavior. Finally, we study its dependency due to the variations in process on a whole production.

  8. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-05-14

    This thesis presents a general framework and method for detection of an object in a video based on apparent motion. The object moves, at some unknown time, differently than the “background” motion, which can be induced from camera motion. The goal of proposed method is to detect and segment the object as soon it moves in an online manner. Since motion estimation can be unreliable between frames, more than two frames are needed to reliably detect the object. Observing more frames before declaring a detection may lead to a more accurate detection and segmentation, since more motion may be observed leading to a stronger motion cue. However, this leads to greater delay. The proposed method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms, defined as declarations of detection before the object moves or incorrect or inaccurate segmentation at the detection time. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  9. Health system delay in treatment of multidrug resistant tuberculosis patients in Bangladesh.

    Science.gov (United States)

    Rifat, Mahfuza; Hall, John; Oldmeadow, Christopher; Husain, Ashaque; Milton, Abul Hasnat

    2015-11-16

    Bangladesh is one of the 27 high burden countries for multidrug resistant tuberculosis listed by the World Health Organization. Delay in multidrug resistant tuberculosis treatment may allow progression of the disease and affect the attempts to curb transmission of drug resistant tuberculosis. The main objective of this study was to investigate the health system delay in multidrug resistant tuberculosis treatment in Bangladesh and to explore the factors related to the delay. Information related to the delay was collected as part of a previously conducted case-control study. The current study restricts analysis to patients with multidrug resistant tuberculosis who were diagnosed using rapid diagnostic methods (Xpert MTB/RIF or the line probe assay). Information was collected by face-to-face interviews and through record reviews from all three Government hospitals providing multidrug resistant tuberculosis services, from September 2012 to April 2013. Multivariable regression analysis was performed using Bootstrap variance estimators. Definitions were as follows: Provider delay: time between visiting a provider for first consultation on MDR-TB related symptom to visiting a designated diagnostic centre for testing; Diagnostic delay: time from date of diagnostic sample provided to date of result; Treatment initiation delay: time between the date of diagnosis and date of treatment initiation; Health system delay: time between visiting a provider to start of treatment. Health system delay was derived by adding provider delay, diagnostic delay and treatment initiation delay. The 207 multidrug resistant tuberculosis patients experienced a health system delay of median 7.1 weeks. The health system delay consists of provider delay (median 4 weeks), diagnostic delay (median 5 days) and treatment initiation delay (median 10 days). Health system delay (Coefficient: 37.7; 95 %; CI 15.0-60.4; p 0.003) was associated with the visit to private practitioners for first consultation

  10. Timing of implant placement after tooth extraction: immediate, immediate-delayed or delayed implants? A Cochrane systematic review.

    Science.gov (United States)

    Esposito, Marco; Grusovin, Maria Gabriella; Polyzos, Ilias P; Felice, Pietro; Worthington, Helen V

    2010-01-01

    This review is based on a Cochrane systematic review entitled ‘Interventions for replacing missing teeth: dental implants in fresh extraction sockets (immediate, immediate-delayed and delayed implants)' published in The Cochrane Library (see http://www.cochrane.org/ for information). Cochrane systematic reviews are regularly updated to include new research, and in response to comments and criticisms from readers. If you wish to comment on this review, please send your comments to the Cochrane website or to Marco Esposito. The Cochrane Library should be consulted for the most recent version of the review. The results of a Cochrane review can be interpreted differently, depending on people's perspectives and circumstances. Please consider the conclusions presented carefully. They are the opinions of the review authors, and are not necessarily shared by the Cochrane Collaboration. To evaluate success, complications, aesthetics and patient satisfaction among immediate, immediate-delayed and delayed implants in post-extractive sockets and whether and when augmentation procedures are necessary and which is the most effective augmentation technique. The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched up to the 2nd of June 2010 for randomised controlled clinical trials (RCTs) with a follow-up of at least 1 year in function comparing immediate, immediate-delayed and delayed implants, or comparing various bone augmentation procedures around the inserted implants. Outcome measures were prosthesis and implant failures, complications, patient satisfaction and preference including aesthetics, aesthetics evaluated by a dentist, peri-implant marginal bone level changes, etc. Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. The statistical unit of the analysis was

  11. Synchronization in networks with heterogeneous coupling delays

    Science.gov (United States)

    Otto, Andreas; Radons, Günter; Bachrathy, Dániel; Orosz, Gábor

    2018-01-01

    Synchronization in networks of identical oscillators with heterogeneous coupling delays is studied. A decomposition of the network dynamics is obtained by block diagonalizing a newly introduced adjacency lag operator which contains the topology of the network as well as the corresponding coupling delays. This generalizes the master stability function approach, which was developed for homogenous delays. As a result the network dynamics can be analyzed by delay differential equations with distributed delay, where different delay distributions emerge for different network modes. Frequency domain methods are used for the stability analysis of synchronized equilibria and synchronized periodic orbits. As an example, the synchronization behavior in a system of delay-coupled Hodgkin-Huxley neurons is investigated. It is shown that the parameter regions where synchronized periodic spiking is unstable expand when increasing the delay heterogeneity.

  12. Managing and avoiding delay in operating theatres: a qualitative, observational study.

    Science.gov (United States)

    Higgins, Vaughan J G; Bryant, Melanie J; Villanueva, Elmer V; Kitto, Simon C

    2013-02-01

    A range of strategies have been proposed to identify and address operating theatre delays, including preoperative checklists, post-delay audits and staff education. These strategies provide a useful starting point in addressing delay, but their effectiveness can be increased through more detailed consideration of sources of surgical delay. A qualitative, observational study was conducted at two Australian hospitals, one a metropolitan site and the other a regional hospital. Thirty surgeries were observed involving general, vascular and orthopaedic procedures which ranged in time from 20 minutes to almost 4 hours. Approximately 40 hours of observations were conducted in total. The research findings suggest that there are two key challenges involved in addressing operating theatre delays: unanticipated problems in the clinical condition of patients, and the capacity of surgeons to regulate their own time. These challenges create unavoidable delays due to the contingencies of surgical work and competing demands on surgeons' time. The results also found that surgical staff play a critical role in averting and anticipating delays. Differences in professional authority are significant in influencing how operating theatre time is managed. Strategies aimed at addressing operating theatre delays are unlikely to achieve their desired aims without a more detailed understanding of medical decision making and work practices, and the intra- as well as inter-professional hierarchies underpinning them. While the nature of surgical work poses some challenges for measures designed to address delays, it is also necessary to focus on surgical practice in devising workable solutions. © 2011 Blackwell Publishing Ltd.

  13. The economic effect and outcome of delaying oral food challenges.

    Science.gov (United States)

    Couch, Christopher; Franxman, Tim; Greenhawt, Matthew

    2016-05-01

    Food specific IgE (sIgE) is a useful marker to assess predictability of oral food challenge (OFC) outcome. A threshold of less than 2 kUA/L for peanut, egg, and milk has been proposed as a 50% negative predictive value at which patients may pass an OFC. To assess the economic effect and outcome of delaying OFCs. A retrospective analysis was performed for peanut, egg, and milk OFCs conducted between 2001 and 2012 at a tertiary food allergy referral center. Delayed OFC was defined as greater than 12 months from the time the sIgE level became less than 2 kUA/L. Time to OFC was explored in association with skin prick test result (wheal size), OFC outcome, and the economic effect of delay. Of 319 challenges, 173 OFCs were delayed (54.2%) by a mean time of 35.5 months (range, 13-123 months) vs a mean time of 4.2 months in the 146 challenges that were not delayed (P care system. Copyright © 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  14. Obesity as a Predictor of Delayed Lactogenesis II.

    Science.gov (United States)

    Preusting, Irma; Brumley, Jessica; Odibo, Linda; Spatz, Diane L; Louis, Judette M

    2017-11-01

    Lactogenesis II is the onset of copious milk production. A delay in this has been associated with an increased risk of formula supplementation and early cessation of breastfeeding. Prepregnancy obesity has also been associated with decreased breastfeeding rates and early cessation. Research aim: This study aimed to evaluate the effect of prepregnancy obesity on self-reported delayed lactogenesis II. We conducted a prospective observational cohort study of 216 women with a singleton pregnancy and who planned to breastfeed. We compared the onset of lactogenesis II between women with a body mass index (BMI) lactogenesis II. The prevalence of delayed lactogenesis II among women with prepregnancy BMI lactogenesis II occurred more frequently among women who were obese at the time of delivery ( p lactogenesis II. Prepregnancy obesity and excessive gestational weight gain are associated with an increased risk of delayed lactogenesis II. Women who are at risk for delay in lactogenesis II and early breastfeeding cessation will need targeted interventions and support for them to achieve their personal breastfeeding goals.

  15. Risk-factors for surgical delay following hip fracture.

    Science.gov (United States)

    Sanz-Reig, J; Salvador Marín, J; Ferrández Martínez, J; Orozco Beltrán, D; Martínez López, J F

    To identify pre-operative risk factors for surgical delay of more than 2 days after admission in patients older than 65 years with a hip fracture. A prospective observational study was conducted on 180 hip fractures in patients older than 65 years of age admitted to our hospital from January 2015 to April 2016. The data recorded included, patient demographics, day of admission, pre-fracture comorbidities, mental state, level of mobility and physical function, type of fracture, antiaggregant and anticoagulant medication, pre-operative haemoglobin value, type of treatment, and surgical delay. The mean age of the patients was 83.7 years. The mean Charlson Index was 2.8. The pre-fracture baseline co-morbidities were equal or greater than 2 in 70% of cases. Mean timing of surgery was 3.1 days. At the time of admission, 122 (67.7%) patients were fit for surgery, of which 80 (44.4%) underwent surgery within 2 days. A Charlson index greater than 2, anticoagulant therapy, and admission on Thursday to Saturday, were independently associated with a surgical delay greater than 2 days. The rate of hip fracture patients undergoing surgery within 2 days is low. Risk factors associated to surgical delay are non-modifiable. However, their knowledge should allow the development of protocols that can reduce surgical delay in this group of patients. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Dynamic Cournot Duopoly Game with Delay

    Directory of Open Access Journals (Sweden)

    A. A. Elsadany

    2014-01-01

    Full Text Available The delay Cournot duopoly game is studied. Dynamical behaviors of the game are studied. Equilibrium points and their stability are studied. The results show that the delayed system has the same Nash equilibrium point and the delay can increase the local stability region.

  17. Synchronization analysis of coloured delayed networks under ...

    Indian Academy of Sciences (India)

    This paper investigates synchronization of coloured delayed networks under decentralized pinning intermittent control. To begin with, the time delays are taken into account in the coloured networks. In addition, we propose a decentralized pinning intermittent control for coloured delayed networks, which is different from that ...

  18. Multidimensional Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of multidimensional heat conduction. General heat conduction equation in three dimensions. Steay state, analytical solutions. The Laplace equation. Method of separation of variables. Principle of superposition. Shape factors. Transient, multidimensional heat conduction....

  19. BOLD delay times using group delay in sickle cell disease

    Science.gov (United States)

    Coloigner, Julie; Vu, Chau; Bush, Adam; Borzage, Matt; Rajagopalan, Vidya; Lepore, Natasha; Wood, John

    2016-03-01

    Sickle cell disease (SCD) is an inherited blood disorder that effects red blood cells, which can lead to vasoocclusion, ischemia and infarct. This disease often results in neurological damage and strokes, leading to morbidity and mortality. Functional Magnetic Resonance Imaging (fMRI) is a non-invasive technique for measuring and mapping the brain activity. Blood Oxygenation Level-Dependent (BOLD) signals contain also information about the neurovascular coupling, vascular reactivity, oxygenation and blood propagation. Temporal relationship between BOLD fluctuations in different parts of the brain provides also a mean to investigate the blood delay information. We used the induced desaturation as a label to profile transit times through different brain areas, reflecting oxygen utilization of tissue. In this study, we aimed to compare blood flow propagation delay times between these patients and healthy subjects in areas vascularized by anterior, middle and posterior cerebral arteries. In a group comparison analysis with control subjects, BOLD changes in these areas were found to be almost simultaneous and shorter in the SCD patients, because of their increased brain blood flow. Secondly, the analysis of a patient with a stenosis on the anterior cerebral artery indicated that signal of the area vascularized by this artery lagged the MCA signal. These findings suggest that sickle cell disease causes blood propagation modifications, and that these changes could be used as a biomarker of vascular damage.

  20. Delay in Presentation, Diagnosis, and Treatment for Breast Cancer Patients in Jordan.

    Science.gov (United States)

    Abu-Helalah, Ahmad Munir; Alshraideh, Hussam Ahmad; Al-Hanaqtah, Mo'tasem; Da'na, Moh'd; Al-Omari, Asim; Mubaidin, Rasmi

    2016-01-01

    Breast cancer is the most common cancer, and one of the leading causes of death for females in Jordan and many countries in the world. Studies have shown that delay in symptoms presentation, diagnosis or treatment would result in poor prognosis. There has been no published study from Jordan on delays in patient presentation, delays in diagnosis, or delays in treatment. Therefore, we conducted this study to assess these important quality indicators aiming to improve prognosis for breast cancer patients in Jordan. This project was a cross-sectional study on female breast cancer patients in Jordan. The total number of participants was 327. The proportion of patients with presentation delay, diagnosis delay, and treatment delay was 32.2%, 49.1%, or 32.4%, respectively. The main reported reasons for delay in presentation were ignorance of the nature of the problem (65.6%), limited/lack of knowledge that symptoms were suggestive of cancer diagnosis (16.7%), and misdiagnosis (16.7%). Predictors of delay and mean time for presentation, diagnosis, and treatment were identified. Our results reveal that breast cancer patients in Jordan are experiencing delays in presentation, diagnosis, and treatment. This could justify the advanced stages at diagnosis and poor outcomes for breast cancer patients in Jordan. We recommend revising the current early detection and down-staging programs in Jordan. © 2015 Wiley Periodicals, Inc.

  1. Reactor shutdown delays medical procedures

    Science.gov (United States)

    Gwynne, Peter

    2008-01-01

    A longer-than-expected maintenance shutdown of the Canadian nuclear reactor that produces North America's entire supply of molybdenum-99 - from which the radioactive isotopes technetium-99 and iodine-131 are made - caused delays to the diagnosis and treatment of thousands of seriously ill patients last month. Technetium-99 is a key component of nuclear-medicine scans, while iodine-131 is used to treat cancer and other diseases of the thyroid. Production eventually resumed, but only after the Canadian government had overruled the Canadian Nuclear Safety Commission (CNSC), which was still concerned about the reactor's safety.

  2. Added value of delayed computed tomography angiography in primary intracranial hemorrhage and hematoma size for predicting spot sign.

    Science.gov (United States)

    Wu, Te Chang; Chen, Tai Yuan; Shiue, Yow Ling; Chen, Jeon Hor; Hsieh, Tsyh-Jyi; Ko, Ching Chung; Lin, Ching Po

    2018-04-01

    Background The computed tomography angiography (CTA) spot sign represents active contrast extravasation within acute primary intracerebral hemorrhage (ICH) and is an independent predictor of hematoma expansion (HE) and poor clinical outcomes. The spot sign could be detected on first-pass CTA (fpCTA) or delayed CTA (dCTA). Purpose To investigate the additional benefits of dCTA spot sign in primary ICH and hematoma size for predicting spot sign. Material and Methods This is a retrospective study of 100 patients who underwent non-contrast CT (NCCT) and CTA within 24 h of onset of primary ICH. The presence of spot sign on fpCTA or dCTA, and hematoma size on NCCT were recorded. The spot sign on fpCTA or dCTA for predicting significant HE, in-hospital mortality, and poor clinical outcomes (mRS ≥ 4) are calculated. The hematoma size for prediction of CTA spot sign was also analyzed. Results Only the spot sign on dCTA could predict high risk of significant HE and poor clinical outcomes as on fpCTA ( P sign on fpCTA or dCTA in the absence of intraventricular and subarachnoid hemorrhage. Conclusion This study clarifies that dCTA imaging could improve predictive performance of CTA in primary ICH. Furthermore, the XY value is the best predictor for CTA spot sign.

  3. Treatment delay among pulmonary tuberculosis patients in pastoralist communities in Bale Zone, Southeast Ethiopia

    Directory of Open Access Journals (Sweden)

    Hussen Awol

    2012-06-01

    Full Text Available Abstract Background Tuberculosis (TB is a major public health problem in Africa with Ethiopia being the most affected. Treatment delay is an important indicator of access to TB diagnosis and treatment. However, little is known about factors associated with treatment delay of pulmonary TB among pastoralists. Health facility based cross sectional study was conducted on 129 pulmonary TB patients in pastoralist community. The study was conducted in three health centers and a hospital. Time between onset of TB symptoms and first visit to a professional health care provider (patient delay, and the time between first visits to the professional health care provider to the date of diagnosis (provider's delay were analyzed using SPSS 16.0 statistical software. Findings A total of 129 new smear positive pulmonary TB patients participated in the study. The median total delay was 97 days. The median patient and health provider delays were 63 and 34 days, respectively. Ninety six percent of the patients were delayed for more than the twenty one days cutoff point. Patient delay was positively associated with first visit to traditional healer/private clinic/drug shop, rural residence, being illiterate, living in more than 10 kilometers from health facility; severity of illness at first presentation to health facility. Provider delay was positively associated with rural residence, being illiterate, patient with good functional status, patients in contact with more than two health providers, and place of first visit being traditional healer/private clinic/drug shop. Conclusions This study showed that majority of smear positive patients delayed either for diagnosis or treatment, thus continue to serve as reservoirs of infection. This indicates that there is a need for intervention to decrease patient and provider delays. Effort to reduce delays in pastoralist communities should focus on improving access to services in rural communities, engaging traditional and

  4. Delay Variation Model with Two Service Queues

    Directory of Open Access Journals (Sweden)

    Filip Rezac

    2010-01-01

    Full Text Available Delay in VoIP technology is very unpleasant issue and therefore a voice packets prioritization must be ensured. To maintain the high call quality a maximum information delivery time from the sender to the recipient is set to 150 ms. This paper focuses on the design of a mathematical model of end-to-end delay of a VoIP connection, in particular on a delay variation. It describes all partial delay components and mechanisms, their generation, facilities and mathematical formulations. A new approach to the delay variation model is presented and its validation has been done by experimention.

  5. Fuzzy delay model based fault simulator for crosstalk delay fault test ...

    Indian Academy of Sciences (India)

    In this paper, a fuzzy delay model based crosstalk delay fault simulator is proposed. As design trends move towards nanometer technologies, more number of new parameters affects the delay of the component. Fuzzy delay models are ideal for modelling the uncertainty found in the design and manufacturing steps.

  6. Multiuser Delay-Tracking CDMA Receiver

    Directory of Open Access Journals (Sweden)

    Zha Wei

    2002-01-01

    Full Text Available We propose to integrate delay tracking into a successive interference cancellation (SIC code division multiple access (CDMA multiuser detector. Delay-robust SIC was initially proposed for CDMA multiuser detection when there exist time delay estimation errors. When the delay error is small, the true user signature vector can be approximately expanded around the estimated time delay as a linear combination of an estimated signature vector and an error vector. The amplitude of the error signal can be recursively estimated and cancelled in the multistage SIC iterations by using the tentative feedback decisions. Since the relative amplitude of the error signal provides information about the delay error, we propose the application of error signal feedback to improve the delay estimation. In a sliding window implementation, the delay-robust SIC is used to track multiple time varying user delays. For constant or slowly varying channels, a soft-decision function can be used to improve the delay-robust SIC. For fast fading channels, a linear decision function is used. Delay-tracking results for both rectangular chip pulses and band-limited chip pulses are shown.

  7. PRECISION TIME-DELAY GENERATOR

    Science.gov (United States)

    Carr, B.J.; Peckham, V.D.

    1959-06-16

    A precision time-delay generator circuit with low jitter is described. The first thyratron has a series resonant circuit and a diode which is connected to the second thyratron. The first thyratron is triggered at the begin-ning of a time delay and a capacitor is discharged through the first thyratron and the diode, thereby, triggering the second thyratron. (T.R.H.) l6l9O The instrument described can measure pressures between sea level and 300,000 ft. The pressure- sensing transducer of the instrument is a small cylindrical tube with a thin foil of titanium-tritium fastened around the inside of the tube. Output is a digital signal which can be used for storage or telemetering more conveniently than an analog signal. (W.D.M.) l6l9l An experimental study was made on rolling contacts in the temperature range of 550 to 1000 deg F. Variables such as material composition, hardness, and operating conditions were investigated in a rolling test stand. Ball bearing tests were run to determine the effect of design parameters, bearing materials, lubricants, and operating conditions. (auth)

  8. Cross delay line sensor characterization

    Energy Technology Data Exchange (ETDEWEB)

    Owens, Israel J [Los Alamos National Laboratory; Remelius, Dennis K [Los Alamos National Laboratory; Tiee, Joe J [Los Alamos National Laboratory; Buck, Steven E [Los Alamos National Laboratory; Whittemore, Stephen R [Los Alamos National Laboratory; Thompson, David C [Los Alamos National Laboratory; Shirey, Robert [Los Alamos National Laboratory

    2010-01-01

    There exists a wealth of information in the scientific literature on the physical properties and device characterization procedures for complementary metal oxide semiconductor (CMOS), charge coupled device (CCD) and avalanche photodiode (APD) format detectors. Numerous papers and books have also treated photocathode operation in the context of photomultiplier tube (PMT) operation for either non imaging applications or limited night vision capability. However, much less information has been reported in the literature about the characterization procedures and properties of photocathode detectors with novel cross delay line (XDL) anode structures. These allow one to detect single photons and create images by recording space and time coordinate (X, Y & T) information. In this paper, we report on the physical characteristics and performance of a cross delay line anode sensor with an enhanced near infrared wavelength response photocathode and high dynamic range micro channel plate (MCP) gain (> 10{sup 6}) multiplier stage. Measurement procedures and results including the device dark event rate (DER), pulse height distribution, quantum and electronic device efficiency (QE & DQE) and spatial resolution per effective pixel region in a 25 mm sensor array are presented. The overall knowledge and information obtained from XDL sensor characterization allow us to optimize device performance and assess capability. These device performance properties and capabilities make XDL detectors ideal for remote sensing field applications that require single photon detection, imaging, sub nano-second timing response, high spatial resolution (10's of microns) and large effective image format.

  9. Delayed coker fractionator advanced control

    Energy Technology Data Exchange (ETDEWEB)

    Jaisinghani, R.; Minter, B. (ABB SIMCON Inc., Houston, TX (United States)); Tica, A.; Puglesi, A.; Ojeda, R. (Yacimentos Petroliferos Fiscales, Mendoza (Argentina))

    1993-08-01

    In a delayed coking process, as coke drum switches are made, rapid changes occur in both the fractionator feed rate and composition. With conventional control, it is not unusual to see long transient behavior of large swings in both quality and flowrates of coker gas oils. This can extract a heavy economic toll, not only in coker operation, but in the operation of downstream units as the upset is propagated. An advanced process control application (APC) was recently implemented on the coker fractionator at the Yacimentos Petroliferos Fiscales (YPF), Lujan de Cuyo Refinery, in Mendoza, Argentina. This coker fractionator control design was unique as it handled two different operating objectives: control of product qualities via tower temperature profile during normal operation and control of gas oil product flow ratio during drum switch. This combination of control objectives in one multivariable predictive control program was achieved by including special logic to decouple the individual tuning requirements. Also, additional logic was included to unambiguously detect and identify drum switch and drum steam out as discrete events within 30 seconds of their actual occurrence. These discrete events were then used as disturbance variables to minimize fractionator transient behavior. As a performance measure, the overhead temperature was controlled within 2 C to 2.5 C of its target, gas oil flows were stabilized during drum switches and steam generation via pump around was maximized. Overall, implementing advanced control for the delayed coker fractionator resulted in substantial benefits from product quality control, product flow control and minimized energy consumption.

  10. Reasons for diagnostic delay in gynecological malignancies

    DEFF Research Database (Denmark)

    Vandborg, Mai Partridge; Christensen, René dePont Christensen; Kragstrup, Jakob

    2011-01-01

    Aim The primary aim of this study was to identify and describe different delay types in women with gynecologic cancer, and to analyze the relationship between diagnostic delay and a number of characteristics for patients, cancers and the health care system. Setting A cohort study of women newly......) and The Danish Gynecological Cancer Database (DGCD). 161 women were included; ovarian cancer: 63, endometrial cancer: 50, cervical cancer: 34 and vulvar cancer: 14. Outcome measures were different delay types counted in days and the influence of four clinical important variables: Presence of alarm symptoms, age...... (≤ or > 60 years), performance of gynecological examination by the GP and notification of cancer suspicion on first referral from GP’s on the diagnostic delay (short delay ≤90 days and long delay >90 days). Results Across cancer type a median total delay of 101 days was observed. The 10% of women...

  11. Large Deviations for Gaussian Diffusions with Delay

    Science.gov (United States)

    Azencott, Robert; Geiger, Brett; Ott, William

    2018-01-01

    Dynamical systems driven by nonlinear delay SDEs with small noise can exhibit important rare events on long timescales. When there is no delay, classical large deviations theory quantifies rare events such as escapes from metastable fixed points. Near such fixed points, one can approximate nonlinear delay SDEs by linear delay SDEs. Here, we develop a fully explicit large deviations framework for (necessarily Gaussian) processes X_t driven by linear delay SDEs with small diffusion coefficients. Our approach enables fast numerical computation of the action functional controlling rare events for X_t and of the most likely paths transiting from X_0 = p to X_T=q. Via linear noise local approximations, we can then compute most likely routes of escape from metastable states for nonlinear delay SDEs. We apply our methodology to the detailed dynamics of a genetic regulatory circuit, namely the co-repressive toggle switch, which may be described by a nonlinear chemical Langevin SDE with delay.

  12. Asymptotic Delay Analysis for Cross-Layer Delay-Based Routing in Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Philippe Jacquet

    2007-01-01

    Full Text Available This paper addresses the problem of the evaluation of the delay distribution via analytical means in IEEE 802.11 wireless ad hoc networks. We show that the asymptotic delay distribution can be expressed as a power law. Based on the latter result, we present a cross-layer delay estimation protocol and we derive new delay-distribution-based routing algorithms, which are well adapted to the QoS requirements of real-time multimedia applications. In fact, multimedia services are not sensitive to average delays, but rather to the asymptotic delay distributions. Indeed, video streaming applications drop frames when they are received beyond a delay threshold, determined by the buffer size. Although delay-distribution-based routing is an NP-hard problem, we show that it can be solved in polynomial time when the delay threshold is large, because of the asymptotic power law distribution of the link delays.

  13. Ranking of delay factors in construction projects after Egyptian revolution

    Directory of Open Access Journals (Sweden)

    Remon Fayek Aziz

    2013-09-01

    Full Text Available Time is one of the major considerations throughout project management life cycle and can be regarded as one of the most important parameters of a project and the driving force of project success. Time delay is a very frequent phenomenon and is almost associated with nearly all constructing projects. However, little effort has been made to curtail the phenomenon, this research work attempts to identify, investigate, and rank factors perceived to affect delays in the Egyptian construction projects with respect to their relative importance so as to proffer possible ways of coping with this phenomenon. To achieve this objective, researcher invited practitioners and experts, comprising a statistically representative sample to participate in a structured questionnaire survey. Brain storming was taken into consideration, through which a number of delay factors were identified in construction projects. Totally, ninety-nine (99 factors were short-listed to be made part of the questionnaire survey and were identified and categorized into nine (9 major categories. The survey was conducted with experts and representatives from private, public, and local general construction firms. The data were analyzed using Relative Importance Index (RII, ranking and simple percentages. Ranking of factors and categories was demonstrated according to their importance level on delay, especially after 25/1/2011 (Egyptian revolution. According to the case study results, the most contributing factors and categories (those need attention to delays were discussed, and some recommendations were made in order to minimize and control delays in construction projects. Also, this paper can serve as a guide for all construction parties with effective management in construction projects to achieve a competitive level of quality and a time effective project.

  14. Delayed response in ipilimumab therapy.

    Science.gov (United States)

    Megahed, Ahmed; Faulhaber, Peter; Phillips, Tycel; Koon, Henry

    2014-03-01

    Metastatic melanoma is a deadly disease with a 5-year survival rate lower than 20%. In 2011, ipilimumab, a fully humanized antibody that binds to cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) was approved by the US Food and Drug Administration based on improved survival in a pivotal trial. CTLA4 is a molecule on cytotoxic T-lymphocytes that plays a critical role in attenuating immune responses. Ipilimumab blocks the binding of B7, the ligand of CTLA4, thereby blocking the activation of CTLA4 and sustaining antitumor immune responses. The time course to response can be variable with immunotherapeutics. We report on a patient who experienced a considerable delay before responding to ipilimumab.

  15. Complex conductivity of soils

    DEFF Research Database (Denmark)

    Revil, A.; Coperey, A.; Shao, Z.

    2017-01-01

    The complex conductivity of soil remains poorly known despite the growing importance of this method in hyrogeophysics. In order to fill this gap of knowledge, we investigate the complex conductivity of 71 soils samples (including 4 peat samples) and one clean sand in the frequency range 0.1 Hertz...... to 45 kHz. The soil samples are saturated with 6 different NaCl brines with conductivities (0.031, 0.53, 1.15, 5.7, 14.7, and 22 S m-1, NaCl, 25°C) in order to determine their intrinsic formation factor and surface conductivity. This dataset is used to test the predictions of the dynamic Stern...... polarization model of porous media in terms of relationship between the quadrature conductivity and the surface conductivity. We also investigate the relationship between the normalized chargeability (the difference of in phase conductivity between two frequencies) and the quadrature conductivity...

  16. Cardiac conduction system

    Science.gov (United States)

    The cardiac conduction system is a group of specialized cardiac muscle cells in the walls of the heart that send signals to the ... contract. The main components of the cardiac conduction system are the SA node, AV node, bundle of ...

  17. Time Delay Estimation Algoritms for Echo Cancellation

    Directory of Open Access Journals (Sweden)

    Kirill Sakhnov

    2011-01-01

    Full Text Available The following case study describes how to eliminate echo in a VoIP network using delay estimation algorithms. It is known that echo with long transmission delays becomes more noticeable to users. Thus, time delay estimation, as a part of echo cancellation, is an important topic during transmission of voice signals over packetswitching telecommunication systems. An echo delay problem associated with IP-based transport networks is discussed in the following text. The paper introduces the comparative study of time delay estimation algorithm, used for estimation of the true time delay between two speech signals. Experimental results of MATLab simulations that describe the performance of several methods based on cross-correlation, normalized crosscorrelation and generalized cross-correlation are also presented in the paper.

  18. Delays in the management of retroperitoneal sarcomas

    DEFF Research Database (Denmark)

    Seinen, Jojanneke; Almquist, Martin; Styring, Emelie

    2010-01-01

    Retroperitoneal sarcomas are rare and treatment should optimally be centralized. Despite successful centralization with 90% of the patients referred prior to surgery, delays occur, which led us to assess lead times in a population-based series. Method. Patients diagnosed with retroperitoneal...... sarcoma in the southern Sweden health care region 2003-2009 were eligible for the study. Data on referrals and diagnostic investigations were collected from clinical files from primary health care, local hospitals, and from the sarcoma centre. Lead times were divided into patient delays and health care...... delays caused by primary health care, local hospitals, or procedures at the sarcoma centre. Results. Complete data were available from 33 patients and demonstrated a median patient delay of 23¿days (0-17¿months) and median health care delay of 94¿days (1-40¿months) with delays of median 15¿days...

  19. Delays in the management of retroperitoneal sarcomas

    DEFF Research Database (Denmark)

    Seinen, Jojanneke; Almquist, Martin; Styring, Emelie

    2010-01-01

    Retroperitoneal sarcomas are rare and treatment should optimally be centralized. Despite successful centralization with 90% of the patients referred prior to surgery, delays occur, which led us to assess lead times in a population-based series. Method. Patients diagnosed with retroperitoneal...... sarcoma in the southern Sweden health care region 2003-2009 were eligible for the study. Data on referrals and diagnostic investigations were collected from clinical files from primary health care, local hospitals, and from the sarcoma centre. Lead times were divided into patient delays and health care...... delays caused by primary health care, local hospitals, or procedures at the sarcoma centre. Results. Complete data were available from 33 patients and demonstrated a median patient delay of 23 days (0-17 months) and median health care delay of 94 days (1-40 months) with delays of median 15 days...

  20. Memorized discrete systems and time-delay

    CERN Document Server

    Luo, Albert C J

    2017-01-01

    This book examines discrete dynamical systems with memory—nonlinear systems that exist extensively in biological organisms and financial and economic organizations, and time-delay systems that can be discretized into the memorized, discrete dynamical systems. It book further discusses stability and bifurcations of time-delay dynamical systems that can be investigated through memorized dynamical systems as well as bifurcations of memorized nonlinear dynamical systems, discretization methods of time-delay systems, and periodic motions to chaos in nonlinear time-delay systems. The book helps readers find analytical solutions of MDS, change traditional perturbation analysis in time-delay systems, detect motion complexity and singularity in MDS; and determine stability, bifurcation, and chaos in any time-delay system.

  1. Permutation entropy with vector embedding delays

    Science.gov (United States)

    Little, Douglas J.; Kane, Deb M.

    2017-12-01

    Permutation entropy (PE) is a statistic used widely for the detection of structure within a time series. Embedding delay times at which the PE is reduced are characteristic timescales for which such structure exists. Here, a generalized scheme is investigated where embedding delays are represented by vectors rather than scalars, permitting PE to be calculated over a (D -1 ) -dimensional space, where D is the embedding dimension. This scheme is applied to numerically generated noise, sine wave and logistic map series, and experimental data sets taken from a vertical-cavity surface emitting laser exhibiting temporally localized pulse structures within the round-trip time of the laser cavity. Results are visualized as PE maps as a function of embedding delay, with low PE values indicating combinations of embedding delays where correlation structure is present. It is demonstrated that vector embedding delays enable identification of structure that is ambiguous or masked, when the embedding delay is constrained to scalar form.

  2. Diagnostic delay among pulmonary tuberculosis patients in Sarawak, Malaysia: a cross-sectional study.

    Science.gov (United States)

    Chang, Ching Thon; Esterman, Adrain

    2007-01-01

    Delayed diagnosis of tuberculosis (TB) can lead to an increased period of infectivity in the community, a delay in treatment and a severe form of the disease. The objective of this study was to determine the length of delay, and factors linking the delay from the onset of symptoms of pulmonary tuberculosis (PTB) until the commencement of treatment in Sarawak, Malaysia. An institution based cross-sectional study was conducted in 10 TB clinics in randomly selected divisions in Sarawak from June 2003 to May 2004. Delay was analyzed from two perspectives: (1) period between the onset of TB symptoms to any first medical consultation (patients' delay); and (2) period between the first medical consultation to the diagnosis of TB (diagnosis delay). Patients were interviewed on diagnosis or within the admission period using a semi-structured questionnaire. A total of 316 new smear-positive PTB patients participated in the study. The median patient interval was 30 days. Gender was found to be significantly associated with patient delay. The median diagnosis interval was 22 days. Respondents' incomes, health-care professional first consulted and actions taken by the health-care providers during the first consultation were significantly associated with diagnosis delay. The medium treatment interval was 0 days. Both patients and health providers played a role in delaying TB diagnosis. Females appeared to have longer delay. Respondents living above the poverty line had diagnosis delay as they made more visits to GPs or different government clinics without proper investigations for TB. A mechanism is needed to increase all health-care providers' suspicion of TB so that proper investigations can be done during first consultation.

  3. A Polynomial Estimate of Railway Line Delay

    DEFF Research Database (Denmark)

    Cerreto, Fabrizio; Harrod, Steven; Nielsen, Otto Anker

    2017-01-01

    by numerical analysis with simulation. This paper proposes an analytical estimate of aggregate delay with a polynomial form. The function returns the aggregate delay of a railway line resulting from an initial, primary, delay. Analysis of the function demonstrates that there should be a balance between the two...... remedial measures, supplement and buffer. Numerical analysis of a Copenhagen Sbane line shows that the polynomial function is valid even when theoretical assumptions are violated....

  4. Stability investigation of quadratic systems with delay

    Directory of Open Access Journals (Sweden)

    Vladimir Davydov

    2000-01-01

    Full Text Available Systems of differential equations with quadratic right-hand sides with delay are considered in the paper. Compact matrix notation form is proposed for the systems of such type. Stability investigations are performed by Lyapunov's second method with functions of quadratic form. Stability conditions of quadratic systems with delay, uniformly by argument deviation, and with delay depending on the system's parameters are derived. A guaranteed radius of the ball of asymptotic stability region for zero solution is obtained.

  5. Delayed enhanced MRI in intraparenchymal tumors

    International Nuclear Information System (INIS)

    Eguchi, Takahiko; Morimoto, Tetsuya; Takeshima, Toshikazu

    1991-01-01

    Delayed enhanced MRI was performed on 20 intraparenchymal tumors, and these findings were compared with those of early enhanced MRI. Using the spin-echo technique (SE: 400-500/20 msec), early scans were obtained 5 minutes, and delayed scans were obtained 60 minutes, after the intravenous injection of 0.1 nmol of gadolinium-DTPA/Kg. We discussed the changes in the delayed scan with regard to the change in the pattern of enhancement and the boundary of enhancement. In these twenty intraparenchymal tumors, there were three low-grade astrocytomas, two anaplastic astrocytomas, seven glioblastomas, and eight metastatic tumors. The changes in the enhanced pattern showed three types as follows: Type I: heterogeneous enhancement in both early and delayed scans; Type II: heterogeneous enhancement in early scan and homogeneous enhancement in delayed scan; Type III: homogeneous enhancement in both early and delayed scans. Most malignant tumors, such as glioblastomas (6/8), anaplastic astrocytomas (2/2), and metastatic tumors (7/8), revealed Type I, although low-grade astrocytomas showed Type II (3/2) and Type III (1/3). The heterogeneous enhancement in delayed scan was found in malignant tumors and in low-grade astrocytoma; even if the early scan revealed heterogeneous enhancement, the delayed scan showed homogeneous enhancement. In the delayed scan, most enhanced boundaries spread out of the boundaries in the early scan. Glioblastomas spread markedly in the delayed scan, although none of the low-grade astrocytomas, anaplastic astrocytomas, or metastases revealed marked spreading. We called these marked increases in the delayed scan a 'spreading sign' and thought that this sign was specific to glioblastomas. Recently some authors have emphasized the usefulness of serial scans. Delayed enhanced MRI 60 minutes after the administration of a contrast medium was here found also to be useful for the accurate diagnosis for brain tumors. (author)

  6. Faktor - Faktor Yang Mempengaruhi Audit Delay

    OpenAIRE

    Christine Tamba

    2010-01-01

    The aim for this study to investigate the influence of right issue, financial leverage, audit committee education, firm performance and audit opinion on audit delay. The samples consist of listed manufactured firms from 2005 to 2009. The results show that tight issue, audit committee education, and firm leverage significantly influence on audit delay. But, audit opinion and financial leverage do not significantly influence on audit delay. Keywords : Right isisue, Leverage, Education, Perfo...

  7. Conducting polymer materials

    Directory of Open Access Journals (Sweden)

    Jovanović Slobodan M.

    2003-01-01

    Full Text Available Conducting polymers represent a very interesting group of polymer materials Investigation of the synthesis, structure and properties of these materials has been the subject of considerable research efforts in the last twenty years. A short presentating of newer results obtained by investigating of the synthesis, structure and properties of two basic groups of conducting polymers: a conducting polymers the conductivity of which is the result of their molecular structure, and b conducting polymer composites (EPC, is given in this paper. The applications and future development of this group of polymer materials is also discussed.

  8. The Cricket Cercal System Implements Delay-Line Processing

    Science.gov (United States)

    Mulder-Rosi, Jonas; Cummins, Graham I.

    2010-01-01

    The cercal sensory system of crickets mediates sensitivity to low-amplitude air currents. The sense organ for this system is a pair of antenna-like abdominal appendages called cerci, each of which is about 1 cm long in normal adult crickets. Although this system has been used extensively as a model system for studying the mechanisms underlying neural coding at the cellular and system levels, no previous studies have considered the functional significance of the physical dimensions of cerci. We show that the differential conduction characteristics of the receptor array in Acheta domesticus crickets are of substantial significance. All filiform sensory afferent axons we examined had the same propagation speeds to within a small variance, resulting in a significant and systematic differential propagation time for spikes from sensory receptors at different locations along the structure. Thus the sensory structures operate as delay lines. The delay-line structure supports neural computations in many of the projecting cercal interneurons (INs) that yield substantial differential sensitivity to the direction and velocity of naturalistic stimuli. Several INs show delay-line-derived sensitivities that are equivalent, in an engineering sense, to “notch filtering,” through which background noise is selectively eliminated by the delay-line-based processing. PMID:20107118

  9. Neutron stochastic transport theory with delayed neutrons

    International Nuclear Information System (INIS)

    Munoz-Cobo, J.L.; Verdu, G.

    1987-01-01

    From the stochastic transport theory with delayed neutrons, the Boltzmann transport equation with delayed neutrons for the average flux emerges in a natural way without recourse to any approximation. From this theory a general expression is obtained for the Feynman Y-function when delayed neutrons are included. The single mode approximation for the particular case of a subcritical assembly is developed, and it is shown that Y-function reduces to the familiar expression quoted in many books, when delayed neutrons are not considered, and spatial and source effects are not included. (author)

  10. Controllability and stability of primary frequency control from thermostatic loads with delays

    DEFF Research Database (Denmark)

    Ziras, Charalampos; Vrettos, Evangelos; You, Shi

    2017-01-01

    There is an increasing interest in exploiting the flexibility of loads to provide ancillary services to the grid. In this paper we study how response delays and lockout constraints affect the controllability of an aggregation of refrigerators offering primary frequency control (PFC). First we...... examine the effect of delays in PFC provision from an aggregation of refrigerators, using a two-area power system. We propose a framework to systematically address frequency measurement and response delays and we determine safe values for the total delays via simulations. We introduce a controllability...... index to evaluate PFC provision under lockout constraints of refrigerators compressors. We conduct extensive simulations to study the effects of measurement delay, ramping times, lockout durations and rotational inertia on the controllability of the aggregation and system stability. Finally, we discuss...

  11. [Delayed posthypoxic leukoencephalopathy: case reports].

    Science.gov (United States)

    Okuda, Shiho; Ueno, Masao; Hayakawa, Michiko; Araki, Manabu; Kanda, Fumio; Takano, Shin

    2012-01-01

    Delayed posthypoxic leukoencephalopathy (DPL) is a rare and less well known complication of hypoxic brain injury. Although it is well known that anoxic or hypoxic injury produces acute neurologic deficits, DPL typically manifests days to weeks after apparent recovery from an obtunded state, and patients with DPL demonstrate cognitive impairment, high brain dysfunction, parkinsonism, or psychosis. MRI findings of the brain demonstrate deep white matter abnormalities. We report 2 cases of DPL after hypoxia due to benzodiazepine overdose. Both of our patients had normal arylsulfatase A activity. Although DPL is seen in carbon monoxide poisoning, pseudodeficiency of arylsulfatase A activity, or drug overdose with heroin or morphine, there are only some previous studies of DPL caused by an overdose with benzodiazepine. It is unclear whether neurotoxicity from the drug in addition to hypoxia alone is involved, however, it is important to note that overdose of common drugs as sleeping medicine can cause DPL. Since DPL may often be misdiagnosed and be subjected to unnecessary treatments, it is also important to understand its unique clinical course and MRI findings. With prompt recognition of DPL, we expect that more cases of DPL caused by overdose with benzodiazepine will be diagnosed, because benzodiazepine overdoses are common.

  12. Diagnostic and treatment delay among pulmonary tuberculosis patients in Ethiopia: a cross sectional study

    Directory of Open Access Journals (Sweden)

    Yimer Solomon

    2005-12-01

    Full Text Available Abstract Background Delayed diagnosis and treatment of tuberculosis (TB results in severe disease and a higher mortality. It also leads to an increased period of infectivity in the community. The objective of this study was to determine the length of delays, and analyze the factors affecting the delay from onset of symptoms of pulmonary tuberculosis (PTB until the commencement of treatment. Methods In randomly selected TB management units (TBMUs, i.e. government health institutions which have diagnosing and treatment facilities for TB in Amhara Region, we conducted a cross sectional study from September 1-December 31/2003. Delay was analyzed from two perspectives, 1. Period between onset of TB symptoms to first visit to any health provider (health seeking period, and from the first health provider visit to initiation of treatment (health providers' delay, and 2. Period between onset of TB symptoms to first visit to a medical provider (patients' delay, and from this visit to commencement of anti-TB treatment (health systems' delay. Patients were interviewed on the same date of diagnosis using a semi-structured questionnaire. Logistics regression analysis was applied to analyze the risk factors of delays. Results A total of 384 new smear positive PTB patients participated in the study. The median total delay was 80 days. The median health-seeking period and health providers' delays were 15 and 61 days, respectively. Conversely, the median patients' and health systems' delays were 30 and 21 days, respectively. Taking medical providers as a reference point, we found that forty eight percent of the subjects delayed for more than one month. Patients' delays were strongly associated with first visit to non-formal health providers and self treatment (P Conclusion Delay in the diagnosis and treatment of PTB is unacceptably high in Amhara region. Health providers' and health systems' delays represent the major portion of the total delay. Accessing a

  13. Feedback and feedforward adaptation to visuomotor delay during reaching and slicing movements.

    Science.gov (United States)

    Botzer, Lior; Karniel, Amir

    2013-07-01

    It has been suggested that the brain and in particular the cerebellum and motor cortex adapt to represent the environment during reaching movements under various visuomotor perturbations. It is well known that significant delay is present in neural conductance and processing; however, the possible representation of delay and adaptation to delayed visual feedback has been largely overlooked. Here we investigated the control of reaching movements in human subjects during an imposed visuomotor delay in a virtual reality environment. In the first experiment, when visual feedback was unexpectedly delayed, the hand movement overshot the end-point target, indicating a vision-based feedback control. Over the ensuing trials, movements gradually adapted and became accurate. When the delay was removed unexpectedly, movements systematically undershot the target, demonstrating that adaptation occurred within the vision-based feedback control mechanism. In a second experiment designed to broaden our understanding of the underlying mechanisms, we revealed similar after-effects for rhythmic reversal (out-and-back) movements. We present a computational model accounting for these results based on two adapted forward models, each tuned for a specific modality delay (proprioception or vision), and a third feedforward controller. The computational model, along with the experimental results, refutes delay representation in a pure forward vision-based predictor and suggests that adaptation occurred in the forward vision-based predictor, and concurrently in the state-based feedforward controller. Understanding how the brain compensates for conductance and processing delays is essential for understanding certain impairments concerning these neural delays as well as for the development of brain-machine interfaces. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  14. Electrically conductive cellulose composite

    Science.gov (United States)

    Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

    2010-05-04

    An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

  15. Graphene Transparent Conductive Electrodes

    Data.gov (United States)

    National Aeronautics and Space Administration — As an atomic layer of graphite, graphene has ultrahigh optical transparency and superior electron mobility. We plan to develop graphene transparent conductive...

  16. Broadband hyperchaotic oscillator with delay line

    DEFF Research Database (Denmark)

    Cenys, Antanas; Lindberg, Erik; Anagnostopoulos, A. N.

    2002-01-01

    Dynamical systems with time delay can be employed as high dimensional hyperchaotic oscillators with multiple positive Lyapunov exponents. We describe an electronic circuit composed of a 3-stage amplifier and a delay line in the feedback loop. The 1st stage of the amplifier is a nonlinear one while...

  17. Programmable delay circuit for sparker signal analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Pathak, D.

    on it to classify the seafloor sediment properties. A specific purpose oriented programmable delay circuit was developed to generate the necessary delay so that the A/D conversion could start just before the arrival of the echo from the water bottom interface...

  18. Discounting of Delayed Rewards Is Not Hyperbolic

    Science.gov (United States)

    Luhmann, Christian C.

    2013-01-01

    Delay discounting refers to decision-makers' tendency to value immediately available goods more than identical goods available only after some delay. In violation of standard economic theory, decision-makers frequently exhibit dynamic inconsistency; their preferences change simply due to the passage of time. The standard explanation for this…

  19. Action for delayed neutron data evaluation

    International Nuclear Information System (INIS)

    Okajima, Shigeaki

    1999-01-01

    Status of NEA/NSC/WPEC/SG6 activities on delayed neutron data evaluation is shortly reviewed. From this review the actions in evaluating the delayed neutron data are proposed to contribute the revise work for the JENDL-3.3 library. (author)

  20. [Delayed asthma bronchiale due to epoxy resin].

    Science.gov (United States)

    Authried, Georg; Al-Asadi, Haifaa; Møller, Ulla; Sherson, David Lee

    2013-10-28

    Epoxy resin is a low molecular weight agent, which can cause both acute and delayed allergic reactions. However, it is known causing skin reactions with direct or airborne contact. Rarely it can cause airway reactions like asthma bronchiale. We describe a case of a windmill worker who developed delayed asthma bronchiale due to airborne contact with epoxy resin.

  1. Analyzing delay causes in Egyptian construction projects.

    Science.gov (United States)

    Marzouk, Mohamed M; El-Rasas, Tarek I

    2014-01-01

    Construction delays are common problems in civil engineering projects in Egypt. These problems occur frequently during project life-time leading to disputes and litigation. Therefore, it is essential to study and analyze causes of construction delays. This research presents a list of construction delay causes retrieved from literature. The feedback of construction experts was obtained through interviews. Subsequently, a questionnaire survey was prepared. The questionnaire survey was distributed to thirty-three construction experts who represent owners, consultants, and contractor's organizations. Frequency Index, Severity Index, and Importance Index are calculated and according to the highest values of them the top ten delay causes of construction projects in Egypt are determined. A case study is analyzed and compared to the most important delay causes in the research. Statistical analysis is carried out using analysis of variance ANOVA method to test delay causes, obtained from the survey. The test results reveal good correlation between groups while there is significant difference between them for some delay causes and finally roadmap for prioritizing delay causes groups is presented.

  2. Recursive Delay Calculation Unit for Parametric Beamformer

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav; Jensen, Jørgen Arendt; Tomov, Borislav Gueorguiev

    2006-01-01

    This paper presents a recursive approach for parametric delay calculations for a beamformer. The suggested calculation procedure is capable of calculating the delays for any image line defined by an origin and arbitrary direction. It involves only add and shift operations making it suitable...

  3. Congenital rubella syndrome and delayed manifestations

    DEFF Research Database (Denmark)

    Dammeyer, Jesper Herup

    2010-01-01

    Objective: Several hypotheses of different medical and psychological delayed manifestations among people who have congenital rubella syndrome (CRS) have been discussed. This study tests some of these hypotheses of delayed manifestations. Methods: Gathering information about 35 individuals who have...

  4. Beta delayed particle emission in light nuclei

    International Nuclear Information System (INIS)

    Riisager, K.; Gabelmann, H.

    1991-01-01

    A short discussion of theoretical treatments of beta delayed particle emission is followed by a presentation of data on the newly found beta delayed deuteron decay of 6 He. This decay cannot be described properly with existing theories. (author) 8 refs.; 3 figs

  5. On Delay and Security in Network Coding

    Science.gov (United States)

    Dikaliotis, Theodoros K.

    2013-01-01

    In this thesis, delay and security issues in network coding are considered. First, we study the delay incurred in the transmission of a fixed number of packets through acyclic networks comprised of erasure links. The two transmission schemes studied are routing with hop-by-hop retransmissions, where every node in the network simply stores and…

  6. Algebraic entropy for differential-delay equations

    OpenAIRE

    Viallet, Claude M.

    2014-01-01

    We extend the definition of algebraic entropy to a class of differential-delay equations. The vanishing of the entropy, as a structural property of an equation, signals its integrability. We suggest a simple way to produce differential-delay equations with vanishing entropy from known integrable differential-difference equations.

  7. Performance characteristics of positive and negative delayed ...

    Indian Academy of Sciences (India)

    The chaotic dynamics of directly modulated semiconductor lasers with delayed optoelectronic feedback is studied numerically. The effects of positive and negative delayed optoelectronic feedback in producing chaotic outputs from such lasers with nonlinear gain reduction in its optimum value range is investigated using ...

  8. Delaying Developmental Mathematics: The Characteristics and Costs

    Science.gov (United States)

    Johnson, Marianne; Kuennen, Eric

    2004-01-01

    This paper investigates which students delay taking a required developmental mathematics course and the impact of delay on student performance in introductory microeconomics. Analysis of a sample of 1462 students at a large Midwestern university revealed that, although developmental-level mathematics students did not reach the same level of…

  9. Delaying gratification depends on social trust

    Directory of Open Access Journals (Sweden)

    Laura eMichaelson

    2013-06-01

    Full Text Available Delaying gratification is hard, yet predictive of important life outcomes, such as academic achievement and physical health. Prominent theories focus on the role of self-control, hypersensitivity to immediate rewards, and the cost of time spent waiting. However, delaying gratification may also require trust in people delivering future rewards as promised. To test the role of social trust, participants were presented with character vignettes and faces that varied in trustworthiness, and then chose between hypothetical smaller immediate or larger delayed rewards from those characters. Across two experiments, participants were less willing to wait for delayed rewards from less trustworthy characters, and perceived trustworthiness predicted willingness to delay gratification. These findings provide the first demonstration of a causal role for social trust in willingness to delay gratification, independent of other relevant factors, such as self-control or reward history. Thus, delaying gratification requires choosing not only a later reward, but a reward that is potentially less likely to be delivered, when there is doubt about the person promising it. Implications of this work include the need to revise prominent theories of delay of gratification, and new directions for interventions with populations characterized by impulsivity.

  10. Congenital rubella syndrome and delayed manifestations

    DEFF Research Database (Denmark)

    Dammeyer, Jesper Herup

    2010-01-01

    Objective: Several hypotheses of different medical and psychological delayed manifestations among people who have congenital rubella syndrome (CRS) have been discussed. This study tests some of these hypotheses of delayed manifestations. Methods: Gathering information about 35 individuals who hav...... which people with CRS face must primarily be understood in relation to congenital deafblindness and dual sensory and communicative deprivation....

  11. Fuzzy delay model based fault simulator for crosstalk delay fault test ...

    Indian Academy of Sciences (India)

    generation is that the test patterns must guarantee not only that the deterministic fault effect is captured correctly ... In digital circuits, the delays associated with each element are different and may not be known with precision for a ... In this paper, the fuzzy delay model is employed for test generation of crosstalk delay faults in.

  12. Delay-dependent exponential stability of cellular neural networks with time-varying delays

    International Nuclear Information System (INIS)

    Zhang Qiang; Wei Xiaopeng; Xu Jin

    2005-01-01

    The global exponential stability of cellular neural networks (CNNs) with time-varying delays is analyzed. Two new sufficient conditions ensuring global exponential stability for delayed CNNs are obtained. The conditions presented here are related to the size of delay. The stability results improve the earlier publications. Two examples are given to demonstrate the effectiveness of the obtained results

  13. DELAYED EFFECTS OF RADIATION ON THE HUMAN CENTRAL NERVOUS SYSTEM. EARLY AND LATE DELAYED REACTIONS,

    Science.gov (United States)

    Two cases of delayed effects of radiation on the central nervous system of man are reported. One demonstrates the rare early delayed reaction which...involvement. This patient is an extreme example of the well-documented late delayed effects of radiation and is presented for contrast with the patient in

  14. Why wait? The social determinants underlying tuberculosis diagnostic delay.

    Directory of Open Access Journals (Sweden)

    Lily Victoria Bonadonna

    Full Text Available Early detection and diagnosis of tuberculosis remain major global priorities for tuberculosis control. Few studies have used a qualitative approach to investigate the social determinants contributing to diagnostic delay and none have compared data collected from individual, community, and health-system levels. We aimed to characterize the social determinants that contribute to diagnostic delay among persons diagnosed with tuberculosis living in resource-constrained settings.Data were collected in public health facilities with high tuberculosis incidence in 19 districts of Lima, Peru. Semi-structured interviews with persons diagnosed with tuberculosis (n = 105 and their family members (n = 63 explored health-seeking behaviours, community perceptions of tuberculosis and socio-demographic circumstances. Focus groups (n = 6 were conducted with health personnel (n = 35 working in the National Tuberculosis Program. All interview data were transcribed and analysed using a grounded theory approach. The median delay between symptom onset and the public health facility visit that led to the first positive diagnostic sample was 57 days (interquartile range 28-126. The great majority of persons diagnosed with tuberculosis distrusted the public health system and sought care at public health facilities only after exhausting other options. It was universally agreed that persons diagnosed with tuberculosis faced discrimination by public and health personnel. Self-medication with medicines bought at local pharmacies was reported as the most common initial health-seeking behaviour due to the speed and low-cost of treatment in pharmacies. Most persons diagnosed with tuberculosis initially perceived their illness as a simple virus.Diagnostic delay was common and prolonged. When individuals reached a threshold of symptom severity, they addressed their health with the least time-consuming, most economically feasible, and well-known healthcare option available to them

  15. Delayed effects of cortisol enhance fear memory of trace conditioning.

    Science.gov (United States)

    Cornelisse, Sandra; van Ast, Vanessa A; Joëls, Marian; Kindt, Merel

    2014-02-01

    Corticosteroids induce rapid non-genomic effects followed by slower genomic effects that are thought to modulate cognitive function in opposite and complementary ways. It is presently unknown how these time-dependent effects of cortisol affect fear memory of delay and trace conditioning. This distinction is of special interest because the neural substrates underlying these types of conditioning may be differently affected by time-dependent cortisol effects. Delay conditioning is predominantly amygdala-dependent, while trace conditioning additionally requires the hippocampus. Here, we manipulated the timing of cortisol action during acquisition of delay and trace fear conditioning, by randomly assigning 63 men to one of three possible groups: (1) receiving 10mg hydrocortisone 240 min (slow cort) or (2) 60 min (rapid cort) before delay and trace acquisition, or (3) placebo at both times, in a double-blind design. The next day, we tested memory for trace and delay conditioning. Fear potentiated startle responses, skin conductance responses and unconditioned stimulus expectancy scores were measured throughout the experiment. The fear potentiated startle data show that cortisol intake 240 min before actual fear acquisition (slow cort) uniquely strengthened subsequent trace conditioned memory. No effects of cortisol delivery 60 min prior to fear acquisition were found on any measure of fear memory. Our findings emphasize that slow, presumably genomic, but not more rapid effects of corticosteroids enhance hippocampal-dependent fear memories. On a broader level, our findings underline that basic experimental research and clinically relevant pharmacological treatments employing corticosteroids should acknowledge the timing of corticosteroid administration relative to the learning phase, or therapeutic intervention. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Delays in the diagnosis and treatment of tuberculosis patients in Vietnam: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Khanh Vu T

    2007-06-01

    Full Text Available Abstract Background Treatment delay is an important indicator of access to tuberculosis diagnosis and treatment. Analyses of patient delay (i.e. time interval between onset of symptoms and first consultation of a health care provider and health care delay (i.e. time interval between first consultation and start of treatment can inform policies to improve access. This study assesses the patient, health care provider and total delay in diagnosis and treatment of new smear-positive pulmonary tuberculosis patients, and the risk factors for long delay, in Vietnam. Methods A cross-sectional survey of new patients treated by the National Tuberculosis Control Programme was conducted in 70 randomly selected districts in Vietnam. All consecutively registered patients in one quarter of 2002 were interviewed using a pre-coded structured questionnaire. Results Median (range delay was 4 weeks (1–48 for total, 3 (1–48 weeks for patient and 1 (0–25 week for health care delay. Patients with long total delay (≥ 12 weeks, 15% accounted for 49% of the cumulative number of delay-weeks. Independent risk factors (p 5 km distance from a health facility or in the northern area. For long health care delay (≥ 6 weeks this was urban setting, residence in the central area and initial visit to a communal health post, TB hospital or the private sector. Conclusion Analyses of patient and treatment delays can indicate target groups and areas for health education and strengthening of the referral system, in particular between the private sector and the NTP.

  17. Diagnostic delay in oral squamous cell carcinoma: the role of cognitive and psychological variables.

    Science.gov (United States)

    Panzarella, Vera; Pizzo, Giuseppe; Calvino, Francesco; Compilato, Domenico; Colella, Giuseppe; Campisi, Giuseppina

    2014-03-01

    This retrospective study investigated, in two cohorts of subjects living in Southern Italy and awaiting treatment for oral squamous cell carcinoma (OSCC), the variables related to diagnostic delay ascribable to the patient, with particular reference to the cognitive and psychological ones. A total of 156 patients with OSCC (mean age: 62 years, M/F: 2.39∶1) were recruited at the Universities of Palermo and Naples. Risk factors related to patient delay included: sociodemographic, health-related, cognitive and psychological variables. The analysis was conducted by considering two different delay ranges: dichotomous (≤1 month vs. >1 month) and polytomous (3 months) delay. Data were investigated by univariate and multivariate analyses and a P value ≤0.05 was considered statistically significant. For both delay measurements, the most relevant variables were: 'Personal experience of cancer' (dichotomous delay: P=0.05, odds ratio (OR)=0.33, 95% confidence interval (CI)=0.11-0.99; polytomous delay: P=0.006, Chi-square=10.224) and 'Unawareness' (dichotomous delay: P<0.01, OR=4.96, 95% CI=2.16-11.37; polytomous delay: P=0.087, Chi-square=4.77). Also 'Denial' (P<0.01, OR=6.84, 95% CI=2.31-20.24) and 'Knowledge of cancer' (P=0.079, Chi-square=8.359) were found to be statistically significant both for dichotomous and for polytomous categorization of delay, respectively. The findings of this study indicated that, in the investigated cohorts, the knowledge about cancer issues is strongly linked to the patient delay. Educational interventions on the Mediterranean population are necessary in order to increase the patient awareness and to emphasize his/her key role in early diagnosis of OSCC.

  18. Gravitational Lens Time Delays Using Polarization Monitoring

    Directory of Open Access Journals (Sweden)

    Andrew Biggs

    2017-11-01

    Full Text Available Gravitational lens time delays provide a means of measuring the expansion of the Universe at high redshift (and therefore in the ‘Hubble flow’ that is independent of local calibrations. It was hoped that many of the radio lenses found in the JVAS/CLASS survey would yield time delays as these were selected to have flat spectra and are dominated by multiple compact components. However, despite extensive monitoring with the Very Large Array (VLA, time delays have only been measured for three of these systems (out of 22. We have begun a programme to reanalyse the existing VLA monitoring data with the goal of producing light curves in polarized flux and polarization position angle, either to improve delay measurements or to find delays for new sources. Here, we present preliminary results on the lens system B1600+434 which demonstrate the presence of correlated and substantial polarization variability in each image.

  19. Controllability of nonlinear delay oscillating systems

    Directory of Open Access Journals (Sweden)

    Chengbin Liang

    2017-05-01

    Full Text Available In this paper, we study the controllability of a system governed by second order delay differential equations. We introduce a delay Gramian matrix involving the delayed matrix sine, which is used to establish sufficient and necessary conditions of controllability for the linear problem. In addition, we also construct a specific control function for controllability. For the nonlinear problem, we construct a control function and transfer the controllability problem to a fixed point problem for a suitable operator. We give a sufficient condition to guarantee the nonlinear delay system is controllable. Two examples are given to illustrate our theoretical results by calculating a specific control function and inverse of a delay Gramian matrix.

  20. Dynamics of microbubble oscillators with delay coupling

    Science.gov (United States)

    Heckman, C. R.; Sah, S. M.; Rand, R. H.

    2010-10-01

    We investigate the stability of the in-phase mode in a system of two delay-coupled bubble oscillators. The bubble oscillator model is based on a 1956 paper by Keller and Kolodner. Delay coupling is due to the time it takes for a signal to travel from one bubble to another through the liquid medium that surrounds them. Using techniques from the theory of differential-delay equations as well as perturbation theory, we show that the equilibrium of the in-phase mode can be made unstable if the delay is long enough and if the coupling strength is large enough, resulting in a Hopf bifurcation. We then employ Lindstedt's method to compute the amplitude of the limit cycle as a function of the time delay. This work is motivated by medical applications involving noninvasive localized drug delivery via microbubbles.

  1. Conductance eigenchannels in nanocontacts

    DEFF Research Database (Denmark)

    Brandbyge, Mads; Sørensen, Mads Reinholdt; Jacobsen, Karsten Wedel

    1997-01-01

    . The conductance as a function of contact elongation exhibits a step structure. For the smallest contact areas of one or a few atom diameters, the conductance is typically quantized, and a specific number of almost open eigenchannels can be ascribed. For larger contact areas the scattering leads to partly open...

  2. Codes of Conduct

    Science.gov (United States)

    Million, June

    2004-01-01

    Most schools have a code of conduct, pledge, or behavioral standards, set by the district or school board with the school community. In this article, the author features some schools that created a new vision of instilling code of conducts to students based on work quality, respect, safety and courtesy. She suggests that communicating the code…

  3. Complex conductivity of soils

    NARCIS (Netherlands)

    Revil, A.; Coperey, A.; Shao, Z.; Florsch, N.; Fabricus, I.L.; Deng, Y.; Delsman, J.R.; Pauw, P.S.; Karaoulis, M.; Louw, P.G.B. de; Baaren, E.S. van; Dabekaussen, W.; Menkovic, A.; Gunnink, J.L.

    2017-01-01

    The complex conductivity of soils remains poorly known despite the growing importance of this method in hydrogeophysics. In order to fill this gap of knowledge, we investigate the complex conductivity of 71 soils samples (including four peat samples) and one clean sand in the frequency range 0.1 Hz

  4. Conducting polymer hydrogels

    Czech Academy of Sciences Publication Activity Database

    Stejskal, Jaroslav

    2017-01-01

    Roč. 71, č. 2 (2017), s. 269-291 ISSN 0366-6352 R&D Projects: GA ČR(CZ) GA16-02787S Institutional support: RVO:61389013 Keywords : aerogel * conducting polymers * conductivity Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 1.258, year: 2016

  5. Conducting Polymeric Materials

    DEFF Research Database (Denmark)

    Hvilsted, Søren

    2016-01-01

    are the charge transfer elements are intrinsically conducting polymers, where the electrical conductivity is a result of delocalized electrons along the polymer backbone, with polyaniline, polypyrrole, and PEDOT as prominent examples. Already in 2000 Alan Heeger, Alan MacDiarmid, and Hideki Shirakawa were...

  6. Thermal conductivity probe

    Science.gov (United States)

    Navickas, J.

    1969-01-01

    Low-mass probe accurately measures the thermal conductivity of polyurethane foam /and other thermal insulating materials/ while exposed to either hydrogen of helium permeation in temperature ranges from ambient to cryogenic. The thermal conductivity of a specimen is determined from an experimentally determined increase in temperature.

  7. The effects of delay duration on visual working memory for orientation.

    Science.gov (United States)

    Shin, Hongsup; Zou, Qijia; Ma, Wei Ji

    2017-12-01

    We used a delayed-estimation paradigm to characterize the joint effects of set size (one, two, four, or six) and delay duration (1, 2, 3, or 6 s) on visual working memory for orientation. We conducted two experiments: one with delay durations blocked, another with delay durations interleaved. As dependent variables, we examined four model-free metrics of dispersion as well as precision estimates in four simple models. We tested for effects of delay time using analyses of variance, linear regressions, and nested model comparisons. We found significant effects of set size and delay duration on both model-free and model-based measures of dispersion. However, the effect of delay duration was much weaker than that of set size, dependent on the analysis method, and apparent in only a minority of subjects. The highest forgetting slope found in either experiment at any set size was a modest 1.14°/s. As secondary results, we found a low rate of nontarget reports, and significant estimation biases towards oblique orientations (but no dependence of their magnitude on either set size or delay duration). Relative stability of working memory even at higher set sizes is consistent with earlier results for motion direction and spatial frequency. We compare with a recent study that performed a very similar experiment.

  8. Understanding Housing Delays and Relocations Within the Housing First Model.

    Science.gov (United States)

    Zerger, Suzanne; Pridham, Katherine Francombe; Jeyaratnam, Jeyagobi; Hwang, Stephen W; O'Campo, Patricia; Kohli, Jaipreet; Stergiopoulos, Vicky

    2016-01-01

    This study explores factors contributing to delays and relocations during the implementation of the Housing First model in Toronto, Ontario. While interruptions in housing tenure are expected en route to recovery and housing stability, consumer and service provider views on finding and keeping housing remain largely unknown. In-person interviews and focus groups were conducted with 48 study participants, including 23 case managers or housing workers and 25 consumers. The following three factors contributed to housing delays and transfers: (1) the effectiveness of communication and collaboration among consumers and service providers, (2) consumer-driven preferences and ambivalence, and (3) provider prioritization of consumer choice over immediate housing access. Two strategies--targeted communications and consumer engagement in housing searches--supported the housing process. Several factors affect the timing and stability of housing. Communication between and among providers and consumers, and a shared understanding of consumer choice, can further support choice and recovery.

  9. Conductivities from attractors

    Energy Technology Data Exchange (ETDEWEB)

    Erdmenger, Johanna [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 Munich (Germany); Institut für Theoretische Physik und Astrophysik, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany); Fernández, Daniel [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 Munich (Germany); Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavík (Iceland); Goulart, Prieslei [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 Munich (Germany); Instituto de Física Teórica, UNESP-Universidade Estadual Paulista,R. Dr. Bento T. Ferraz 271, Bl. II, São Paulo 01140-070, SP (Brazil); Witkowski, Piotr [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 Munich (Germany)

    2017-03-28

    In the context of applications of the AdS/CFT correspondence to condensed matter physics, we compute conductivities for field theory duals of dyonic planar black holes in 3+1-dimensional Einstein-Maxwell-dilaton theories at zero temperature. We combine the near-horizon data obtained via Sen’s entropy function formalism with known expressions for conductivities. In this way we express the conductivities in terms of the extremal black hole charges. We apply our approach to three different examples for dilaton theories for which the background geometry is not known explicitly. For a constant scalar potential, the thermoelectric conductivity explicitly scales as α{sub xy}∼N{sup 3/2}, as expected. For the same model, our approach yields a finite result for the heat conductivity κ/T∝N{sup 3/2} even for T→0.

  10. Dual-anticipating, dual and dual-lag synchronization in modulated time-delayed systems

    International Nuclear Information System (INIS)

    Ghosh, Dibakar; Chowdhury, A. Roy

    2010-01-01

    In this Letter, dual synchronization in modulated time delay system using delay feedback controller is proposed. Based on Lyapunov stability theory, we suggest a general method to achieve the dual-anticipating, dual, dual-lag synchronization of time-delayed chaotic systems and we find both its existing and sufficient stability conditions. Numerically it is shown that the dual synchronization is also possible when driving system contain two completely different systems. Effect of parameter mismatch on dual synchronization is also discussed. As an example, numerical simulations for the Mackey-Glass and Ikeda systems are conducted, which is in good agreement with the theoretical analysis.

  11. Phase delaying the human circadian clock with a single light pulse and moderate delay of the sleep/dark episode: no influence of iris color.

    Science.gov (United States)

    Canton, Jillian L; Smith, Mark R; Choi, Ho-Sun; Eastman, Charmane I

    2009-07-17

    Light exposure in the late evening and nighttime and a delay of the sleep/dark episode can phase delay the circadian clock. This study assessed the size of the phase delay produced by a single light pulse combined with a moderate delay of the sleep/dark episode for one day. Because iris color or race has been reported to influence light-induced melatonin suppression, and we have recently reported racial differences in free-running circadian period and circadian phase shifting in response to light pulses, we also tested for differences in the magnitude of the phase delay in subjects with blue and brown irises. Subjects (blue-eyed n = 7; brown eyed n = 6) maintained a regular sleep schedule for 1 week before coming to the laboratory for a baseline phase assessment, during which saliva was collected every 30 minutes to determine the time of the dim light melatonin onset (DLMO). Immediately following the baseline phase assessment, which ended 2 hours after baseline bedtime, subjects received a 2-hour bright light pulse (~4,000 lux). An 8-hour sleep episode followed the light pulse (i.e. was delayed 4 hours from baseline). A final phase assessment was conducted the subsequent night to determine the phase shift of the DLMO from the baseline to final phase assessment.Phase delays of the DLMO were compared in subjects with blue and brown irises. Iris color was also quantified from photographs using the three dimensions of red-green-blue color axes, as well as a lightness scale. These variables were correlated with phase shift of the DLMO, with the hypothesis that subjects with lighter irises would have larger phase delays. The average phase delay of the DLMO was -1.3 +/- 0.6 h, with a maximum delay of ~2 hours, and was similar for subjects with blue and brown irises. There were no significant correlations between any of the iris color variables and the magnitude of the phase delay. A single 2-hour bright light pulse combined with a moderate delay of the sleep/dark episode

  12. Phase delaying the human circadian clock with a single light pulse and moderate delay of the sleep/dark episode: no influence of iris color

    Directory of Open Access Journals (Sweden)

    Choi Ho-Sun

    2009-07-01

    Full Text Available Abstract Background Light exposure in the late evening and nighttime and a delay of the sleep/dark episode can phase delay the circadian clock. This study assessed the size of the phase delay produced by a single light pulse combined with a moderate delay of the sleep/dark episode for one day. Because iris color or race has been reported to influence light-induced melatonin suppression, and we have recently reported racial differences in free-running circadian period and circadian phase shifting in response to light pulses, we also tested for differences in the magnitude of the phase delay in subjects with blue and brown irises. Methods Subjects (blue-eyed n = 7; brown eyed n = 6 maintained a regular sleep schedule for 1 week before coming to the laboratory for a baseline phase assessment, during which saliva was collected every 30 minutes to determine the time of the dim light melatonin onset (DLMO. Immediately following the baseline phase assessment, which ended 2 hours after baseline bedtime, subjects received a 2-hour bright light pulse (~4,000 lux. An 8-hour sleep episode followed the light pulse (i.e. was delayed 4 hours from baseline. A final phase assessment was conducted the subsequent night to determine the phase shift of the DLMO from the baseline to final phase assessment. Phase delays of the DLMO were compared in subjects with blue and brown irises. Iris color was also quantified from photographs using the three dimensions of red-green-blue color axes, as well as a lightness scale. These variables were correlated with phase shift of the DLMO, with the hypothesis that subjects with lighter irises would have larger phase delays. Results The average phase delay of the DLMO was -1.3 ± 0.6 h, with a maximum delay of ~2 hours, and was similar for subjects with blue and brown irises. There were no significant correlations between any of the iris color variables and the magnitude of the phase delay. Conclusion A single 2-hour bright light

  13. Test Report Emission Test Program EPA Information Collection Request for Delayed Coking Units 736 Coker Unit

    Science.gov (United States)

    ARI Environmental, Inc. (ARI) was retained by Houston Refining LP (HRO) to conduct an emission test program at their refinery located in Houston, Texas. The testing was conducted on on the 736 Delayed Coking Unit (DCU) in response to EPA's ICR.

  14. Microscopic Control Delay Modeling at Signalized Arterials Using Bluetooth Technology

    OpenAIRE

    Rajasekhar, Lakshmi

    2011-01-01

    Real-time control delay estimation is an important performance measure for any intersection to improve the signal timing plans dynamically in real-time and hence improve the overall system performance. Control delay estimates helps to determine the level-of-service (LOS) characteristics of various approaches at an intersection and takes into account deceleration delay, stopped delay and acceleration delay. All kinds of traffic delay calculation especially control delay calculation has always ...

  15. Decreased Nerve Conduction Velocity in Football Players

    Directory of Open Access Journals (Sweden)

    Daryoush Didehdar

    2014-06-01

    Full Text Available Background: Lower limbs nerves are exposed to mechanical injuries in the football players and the purpose of this study is to evaluate the influence of football on the lower leg nerves. Materials and Methods: Nerve conduction studies were done on 35 male college students (20 football players, 15 non active during 2006 to 2007 in the Shiraz rehabilitation faculty. Standard nerve conduction techniques using to evaluate dominant and non dominant lower limb nerves. Results: The motor latency of deep peroneal and tibial nerves of dominant leg of football players and sensory latency of superficial peroneal, tibial and compound nerve action potential of tibial nerve of both leg in football players were significantly prolonged (p<0.05. Motor and sensory nerve conduction velocity of tibial and common peroneal in football players were significant delayed (p<0.05. Conclusion: It is concluded that football is sport with high contact and it causes sub-clinical neuropathies due to nerve entrapment.

  16. Structural and Functional Aspects of Social Support for Mothers of Children with and without Cognitive Delays in Vietnam

    Science.gov (United States)

    Park, So-Youn; Glidden, Laraine M.; Shin, Jin Y.

    2010-01-01

    Background: This study reports development of a social support scale appropriate to the Vietnamese culture and the impact of social support on mothers of children with cognitive delays by using the developing scale. Method: Interview surveys were conducted with 225 mothers of children with and without cognitive delays in Vietnam. The structural…

  17. Measurement of thermal conductance

    International Nuclear Information System (INIS)

    Kuchnir, M.

    1977-01-01

    The 6-m long, 45-kG, warm-iron superconducting magnets envisioned for the Energy Doubler stage of the Fermilab accelerator require stiff supports with minimized thermal conductances in order to keep the refrigeration power reasonable. The large number of supports involved in the system required a careful study of their heat conduction from the room temperature wall to the intercepting refrigeration at 20 0 K and to the liquid helium. For this purpose the thermal conductance of this support was measured by comparing it with the thermal conductance of a copper strap of known geometry. An association of steady-state thermal analysis and experimental thermal conductivity techniques forms the basis of this method. An important advantage is the automatic simulation of the 20 0 K refrigeration intercept by the copper strap, which simplifies the apparatus considerably. This relative resistance technique, which uses electrical analogy as a guideline, is applicable with no restrictions for materials with temperature-independent thermal conductivity. For other materials the results obtained are functions of the specific temperature interval involved in the measurements. A comprehensive review of the literature on thermal conductivity indicates that this approach has not been used before. A demonstration of its self-consistency is stressed here rather than results obtained for different supports

  18. Multivalent ion conducting solids

    Energy Technology Data Exchange (ETDEWEB)

    Imanaka, N. [Osaka Univ., Suita, Osaka (Japan). Dept. of Applied Chemistry

    2008-07-01

    Solid electrolytes possess important characteristics for industrial applications. Only a single ionic species can macroscopically migrate in these solids. This paper described a the new NASICON (M-Zr-Nb-P-O) type system, exhibiting an exceptionally high level of trivalent M3+ ion conductivity on polycrystalline solids. The partial substitution of the smaller higher valent Nb5+ ion for Zr4+ stabilized the NASICON phase and realized the M3+ ion conduction in the NASICON structure. It was concluded that the conductivities of the series are comparable to those of the practically applied solid electrolytes of oxide anion conductors of YSZ and CSZ. 3 refs., 2 figs.

  19. Conducting everyday life

    DEFF Research Database (Denmark)

    Juhl, Pernille

    , they are involved in preventive interventions. I conducted participatory observations with the children in their everyday life. Overall, the study stresses that even small children must be perceived as active participants who act upon and struggle with different conditions and meaning making processes across......In the paper I discuss how small children (0-4 year) develop through ‘conducting everyday life’ across contexts (Holzkamp 2013). I discuss how this process of conducting everyday life is essential when discussing the ‘good life for children’ from a child perspective. These issues are addressed...

  20. Optimal Kalman Filtering for a Class of State Delay Systems with Randomly Multiple Sensor Delays

    Directory of Open Access Journals (Sweden)

    Dongyan Chen

    2014-01-01

    Full Text Available The optimal Kalman filtering problem is investigated for a class of discrete state delay stochastic systems with randomly multiple sensor delays. The phenomenon of measurement delay occurs in a random way and the delay rate for each sensor is described by a Bernoulli distributed random variable with known conditional probability. Based on the innovative analysis approach and recursive projection formula, a new linear optimal filter is designed such that, for the state delay and randomly multiple sensor delays with different delay rates, the filtering error is minimized in the sense of mean square and the filter gain is designed by solving the recursive matrix equation. Finally, a simulation example is given to illustrate the feasibility and effectiveness of the proposed filtering scheme.

  1. Chaos synchronization in time-delayed systems with parameter mismatches and variable delay times

    International Nuclear Information System (INIS)

    Shahverdiev, E.M.; Nuriev, R.A.; Hashimov, R.H.; Shore, K.A.

    2004-06-01

    We investigate synchronization between two undirectionally linearly coupled chaotic nonidentical time-delayed systems and show that parameter mismatches are of crucial importance to achieve synchronization. We establish that independent of the relation between the delay time in the coupled systems and the coupling delay time, only retarded synchronization with the coupling delay time is obtained. We show that with parameter mismatch or without it neither complete nor anticipating synchronization occurs. We derive existence and stability conditions for the retarded synchronization manifold. We demonstrate our approach using examples of the Ikeda and Mackey Glass models. Also for the first time we investigate chaos synchronization in time-delayed systems with variable delay time and find both existence and sufficient stability conditions for the retarded synchronization manifold with the coupling-delay lag time. (author)

  2. Delays in Building Construction Projects in Ghana

    Directory of Open Access Journals (Sweden)

    Frank DK Fugar

    2010-07-01

    Full Text Available This study investigates the causes of delay of building construction projects in Ghana to determine the most important according to the key project participants; clients, consultants, and contractors. Thirty-two possible causes of delay were identified from the literature and semi-structured interviews of 15 key players in the implementation process. These delay factors were further categorised into nine major groups. The list of delay causes was subjected to a questionnaire survey for the identification of the most important causes of delay. The field survey included 130 respondents made up of 39 contractors, 37 clients and 54 consultants. The relative importance of the individual causes and the groups were calculated and ranked by their relative importance index. The overall results of the study indicate that the respondents generally agree that financial group factors ranked highest among the major factors causing delay in construction projects in Ghana. The financial group factors were delay in honouring payment certificates, difficulty in accessing credit and fluctuation in prices. Materials group factors are second followed by scheduling and controlling factors.

  3. Behavioral effects of delayed timeouts from reinforcement.

    Science.gov (United States)

    Byrne, Tom; Poling, Alan

    2017-03-01

    Timeouts are sometimes used in applied settings to reduce target responses, and in some circumstances delays are unavoidably imposed between the onset of a timeout and the offset of the response that produces it. The present study examined the effects of signaled and unsignaled timeouts in rats exposed to concurrent fixed-ratio 1 fixed-ratio 1 schedules of food delivery, where each response on one lever, the location of which changed across conditions, produced both food and a delayed 10-s timeout. Delays of 0 to 38 s were examined. Delayed timeouts often, but not always, substantially reduced the number of responses emitted on the lever that produced timeouts relative to the number emitted on the lever that did not produce timeouts. In general, greater sensitivity was observed to delayed timeouts when they were signaled. These results demonstrate that delayed timeouts, like other delayed consequences, can affect behavior, albeit less strongly than immediate consequences. © 2017 Society for the Experimental Analysis of Behavior.

  4. Anionic Conducting Oxide Ceramics

    National Research Council Canada - National Science Library

    Dunn, Bruce

    1998-01-01

    This program has emphasized the interrelationships among synthesis, microstructure and properties for oxygen ion conducting ceramics based on copper-substituted bismuth vanadate (Bi V Cu O ), known as BICUVOX...

  5. Delayed encephalopathy after acute carbon monoxide poisoning

    Directory of Open Access Journals (Sweden)

    Mehmet İbrahim Turan

    2014-03-01

    Full Text Available Carbon monoxide poisoning is a major cause of death following attempted suicide and accidental exposures. Although clinical presentation depends on the duration and the intensity of exposure, the assessment of the severity of intoxication is difficult. A small percentage of patients who show complete initial recovery may develop delayed neurological deficits. Delayed encephalopathy after acute carbon monoxide poisoning is a rare and poor prognosis neurologic disorders and there is no specific treatment. We present a case with early onset of delayed encephalopathy after acute carbon monoxide poisoning with typical cranial imaging findings in a child with atypical history and clinical presentation.

  6. Transcriptional delay stabilizes bistable gene networks.

    Science.gov (United States)

    Gupta, Chinmaya; López, José Manuel; Ott, William; Josić, Krešimir; Bennett, Matthew R

    2013-08-02

    Transcriptional delay can significantly impact the dynamics of gene networks. Here we examine how such delay affects bistable systems. We investigate several stochastic models of bistable gene networks and find that increasing delay dramatically increases the mean residence times near stable states. To explain this, we introduce a non-Markovian, analytically tractable reduced model. The model shows that stabilization is the consequence of an increased number of failed transitions between stable states. Each of the bistable systems that we simulate behaves in this manner.

  7. A continuous time Cournot duopoly with delays

    International Nuclear Information System (INIS)

    Gori, Luca; Guerrini, Luca; Sodini, Mauro

    2015-01-01

    This paper extends the classical repeated duopoly model with quantity-setting firms of Bischi et al. (1998) by assuming that production of goods is subject to some gestation lags but exchanges take place continuously in the market. The model is expressed in the form of differential equations with discrete delays. By using some recent mathematical techniques and numerical experiments, results show some dynamic phenomena that cannot be observed when delays are absent. In addition, depending on the extent of time delays and inertia, synchronisation failure can arise even in the event of homogeneous firms.

  8. Electrically Conductive Epoxy Adhesives

    Directory of Open Access Journals (Sweden)

    Lan Bai

    2011-02-01

    Full Text Available Conductive adhesives are widely used in electronic packaging applications such as die attachment and solderless interconnections, component repair, display interconnections, and heat dissipation. The effects of film thickness as functions of filler volume fraction, conductive filler size, shape, as well as uncured adhesive matrix viscosity on the electrical conduction behavior of epoxy-based adhesives are presented in this work. For this purpose, epoxy-based adhesives were prepared using conductive fillers of different size, shape, and types, including Ni powder, flakes, and filaments, Ag powder, and Cu powder. The filaments were 20 μm in diameter, and 160 or 260 μm in length. HCl and H3PO4 acid solutions were used to etch and remove the surface oxide layers from the fillers. The plane resistance of filled adhesive films was measured using the four-point method. In all cases of conductive filler addition, the planar resistivity levels for the composite adhesive films increased when the film thickness was reduced. The shape of resistivity-thickness curves was negative exponential decaying type and was modeled using a mathematical relation. The relationships between the conductive film resistivities and the filler volume fractions were also derived mathematically based on the experimental data. Thus, the effects of surface treatment of filler particles, the type, size, shape of fillers, and the uncured epoxy viscosity could be included empirically by using these mathematical relations based on the experimental data. By utilizing the relations we proposed to model thickness-dependent and volume fraction-dependent conduction behaviors separately, we were able to describe the combined and coupled volume fraction-film thickness relationship mathematically based on our experimental data.

  9. Prognosis and delay of diagnosis among Kaposi's sarcoma patients in Uganda: a cross-sectional study.

    Science.gov (United States)

    De Boer, Christopher; Niyonzima, Nixon; Orem, Jackson; Bartlett, John; Zafar, S Yousuf

    2014-01-01

    In low- and middle-income countries, the association between delay to treatment and prognosis for Kaposi's sarcoma (KS) patients is yet to be studied. This is a prospective study of HIV-infected adults with histologically-confirmed KS treated at the Uganda Cancer Institute (UCI). Standardized interviews were conducted in English or Luganda. Medical records were abstracted for KS stage at admission to UCI. Multivariable logistic regression assessed relationships between diagnostic delay and stage at diagnosis. Of 161 patients (90% response rate), 69% were men, and the mean age was 34.0 years (SD 7.7). 26% had been seen in an HIV clinic within 3 months, 72% were on antiretroviral therapy, and 26% had visited a traditional healer prior to diagnosis. 45% delayed seeking care at UCI for ≥3 months from symptom onset. Among those who delayed, 36% waited 6 months, and 25% waited 12 months. Common reasons for delay were lack of pain (48%), no money (32%), and distance to UCI (8%). In adjusted analysis patients who experienced diagnostic delay were more likely than those who did not delay to have poor-risk KS stage (OR 3.41, p = 0.002, 95% CI: 1.46-7.45). In adjusted analyses visiting a traditional healer was the only variable associated with greater likelihood of delay (OR 2.69, p = 0.020, 95% CI: 1.17-6.17). Diagnostic delay was associated with poor-risk stage at diagnosis, and visiting a traditional healer was associated with higher odds of delay. The relationship between traditional and Western medicine presents a critical intervention point to improve KS-related outcomes in Uganda.

  10. Delays during the administration of acetylcysteine for the treatment of paracetamol overdose.

    Science.gov (United States)

    Bailey, George P; Najafi, Javad; Elamin, Muhammad E M O; Waring, W Stephen; Thomas, Simon H L; Archer, John R H; Wood, David M; Dargan, Paul I

    2016-11-01

    The licensed intravenous acetylcysteine regimen for treating paracetamol overdose in most countries uses three separate infusions over 21 h. This complex regimen, requiring different infusion concentrations and rates, has been associated with administration errors. The aim of the present study was to assess the extent of administration delays occurring during this acetylcysteine regimen. A 6-month retrospective observational study was conducted at three English teaching hospitals with clinical toxicology services from October 2014. Patients aged 16 years and over, treated with intravenous acetylcysteine for paracetamol overdose, were included. The start times for infusions were recorded and the delays compared with the prescribed infusion times were calculated. Anaphylactoid reactions, intravenous cannula problems, overdose intent and smoking status were recorded to assess their contribution to delays. From 263 cases identified, 198 met the study inclusion criteria. The median time between the start of infusions 1 and 3 was delayed from the intended 5 h by a median (interquartile range) of 90 (50-163) min, with 135 (68%) cases delayed by more than 1 h. Significantly longer delays were observed in patients with anaphylactoid reactions [median delay 267 (217-413) min, n = 8] and accidental/supratherapeutic overdose [median delay 170 (95-260) min, n = 29]. There were no significant differences between smokers and nonsmokers, or for patients with intravenous cannula problems. Long delays were identified during the three-infusion acetylcysteine regimen for the treatment of paracetamol overdose. These were of clinical significance and could lead to periods of subtherapeutic plasma acetylcysteine concentrations and potentially avoidable hepatotoxicity, as well as delaying hospital discharge. © 2016 The British Pharmacological Society.

  11. Stabilization of time-delay neural networks via delayed pinning impulses

    International Nuclear Information System (INIS)

    Liu, Xinzhi; Zhang, Kexue; Xie, Wei-Chau

    2016-01-01

    This paper studies the pinning stabilization problem of time-delay neural networks. A new pinning delayed-impulsive controller is proposed to stabilize the neural networks with delays. First, we consider the general nonlinear time-delay systems with delayed impulses, and establish several global exponential stability criteria by employing the method of Lyapunov functionals. Our results are then applied to obtain sufficient conditions under which the proposed pinning controller can exponentially stabilize the time-delay neural networks. It is shown that the global exponential stabilization of delayed neural networks can be effectively realized by controlling a small portion of neurons in the networks via delayed impulses, and, for fixed impulsive control gain, increasing the impulse delay or decreasing the number of neurons to be pinned at the impulsive moments will lead to high frequency of impulses added the corresponding neurons. Numerical examples are provided to illustrate the theoretical results, which demonstrate that our results are less conservative than the results reported in the existing literatures when the proposed pinning controller reduces to the delayed impulsive controller.

  12. M549A1 Projectile Delay Assembly Predictive Engineering Analysis in Support of the Ammunition Stockpile Reliability Program

    National Research Council Canada - National Science Library

    Bixon, Eric R; Cassiello, Michael J; McEwan, Jr, John D

    2006-01-01

    Experiments were conducted on M549A1 High Explosive Rocket Assisted projectiles to evaluate the effects of thermal degradation and moisture on the delay assembly, and on the potential for premature rocket ignitions...

  13. The DARWIN breadboard cryogenic optical delay line

    Science.gov (United States)

    van den Dool, T. C.; Gielesen, W.; Kamphues, F.; Loix, N.; Kooijman, P. P.; de Vries, C.; van Weers, H.; Fleury, K.; Stockman, Y.; Velsink, G.; Benoit, J.; Poupinet, A.; Sève, F.

    2017-11-01

    TNO, in cooperation with Micromega-Dynamics, SRON, Dutch Space and CSL, has designed a compact breadboard cryogenic delay line (figure 1) for use in future space interferometry missions. The work is performed under ESA contract 17.747/03 in preparation for the DARWIN mission. The breadboard (BB) delay line is representative of a flight mechanism. The delay line has a single stage voice coil actuator for Optical Path Difference (OPD) control, driving a twomirror cat's eye. Magnetic bearings provide frictionless and wear free operation with zero-hysteresis. The design of the BB delay line has been completed. The development test program, including operation at 100 K has been completed. The verification test programme is currently being carried out and will include functional testing at 40 K.

  14. Framework to Delay Corn Rootworm Resistance

    Science.gov (United States)

    This proposed framework is intended to delay the corn rootworm pest becoming resistant to corn genetically engineered to produce Bt proteins, which kill corn rootworms but do not affect people or wildlife. It includes requirements on Bt corn manufacturers.

  15. Ranking different factors influencing flight delay

    Directory of Open Access Journals (Sweden)

    Meysam Kazemi Asfe

    2014-07-01

    Full Text Available Flight interruption is one of the most important issues in today’s airline industry. Every year, most airlines spend significant amount of money to compensate flight delays. Therefore, it is important to detect important factors influencing on flight delays. This paper presents an empirical investigation to determine important factors on this issue. The study also asks some decision makers to make pairwise comparison and ranks various factors using the art of analytical hierarchy process. The study determines that technical defects and delayed entry were among the most important factors to blame for flight delays. In addition, announcing the postponement, replacement aircraft and path replacement are among the most important decisions facing managers in the aviation industry during the disruption of the flight.

  16. Delaying Your Period with Birth Control Pills

    Science.gov (United States)

    ... prevent periods, especially during the first few months. Breakthrough bleeding typically decreases over time, however, as your body adjusts to the new regimen. Another drawback of routinely delaying your period ...

  17. Impulsive fractional differential inclusions with infinite delay

    Directory of Open Access Journals (Sweden)

    Khalida Aissani

    2013-11-01

    Full Text Available In this article, we apply Bohnenblust-Karlin's fixed point theorem to prove the existence of mild solutions for a class of impulsive fractional equations inclusions with infinite delay. An example is given to illustrate the theory.

  18. Monolithic Time Delay Integrated APD Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of the proposed program by Epitaxial Technologies is to develop monolithic time delay integrated avalanche photodiode (APD) arrays with sensitivity...

  19. A simple chaotic delay differential equation

    International Nuclear Information System (INIS)

    Sprott, J.C.

    2007-01-01

    The simplest chaotic delay differential equation with a sinusoidal nonlinearity is described, including the route to chaos, Lyapunov exponent spectrum, and chaotic diffusion. It is prototypical of many other high-dimensional chaotic systems

  20. Delay and environmental costs of truck crashes

    Science.gov (United States)

    2013-03-01

    This report presents estimates of certain categories of costs of truck- and bus-involved crashes. Crash related costs estimated as part of this study include vehicle delay costs, emission costs, and fuel consumption costs. In addition, this report al...

  1. Delayed Entry Program Attrition: A Multivariate Analysis

    National Research Council Canada - National Science Library

    Ogren, Margery

    1999-01-01

    This thesis uses binary logit models to examine the effects of personal background characteristics and local area economic conditions on an individual's likelihood to leave the Delayed Entry Program (DEP...

  2. Lauch of CERN particle accelerator delayed

    CERN Multimedia

    2007-01-01

    "Scientists seeking to uncover the secrets of the universe will have to wait a little longer after the CERN laboratory inSwitzerland yesterday confirmed a delay in tests of its massive new particle accelerator." (1 page)

  3. Compensating for telecommunication delays during robotic telerehabilitation.

    Science.gov (United States)

    Consoni, Leonardo J; Siqueira, Adriano A G; Krebs, Hermano I

    2017-07-01

    Rehabilitation robotic systems may afford better care and telerehabilitation may extend the use and benefits of robotic therapy to the home. Data transmissions over distance are bound by intrinsic communication delays which can be significant enough to deem the activity unfeasible. Here we describe an approach that combines unilateral robotic telerehabilitation and serious games. This approach has a modular and distributed design that permits different types of robots to interact without substantial code changes. We demonstrate the approach through an online multiplayer game. Two users can remotely interact with each other with no force exchanges, while a smoothing and prediction algorithm compensates motions for the delay in the Internet connection. We demonstrate that this approach can successfully compensate for data transmission delays, even when testing between the United States and Brazil. This paper presents the initial experimental results, which highlight the performance degradation with increasing delays as well as improvements provided by the proposed algorithm, and discusses planned future developments.

  4. Diagnosis delay in tuberculosis and its consequences

    International Nuclear Information System (INIS)

    Habibullah, S.; Sheikh, M.A.; Sadiq, A.; Anwar, T.

    2004-01-01

    Objective: To find out the average duration from onset of symptoms to the diagnosis and treatment of tuberculosis, reasons for diagnostic delay, its consequences, association of variables and formulation of recommendations. Results: In this study it was found that average time from onset of initial symptoms to diagnosis and treatment of tuberculosis was 120 days. In 64% of the patients medical practitioners were responsible for delaying the diagnosis of tuberculosis. Loss of weight in 40% and haemoptysis is 21% were the consequences of diagnostic delay of tuberculosis. Delay in the diagnosis of tuberculosis was statistically significant in those patients who consulted private practitioners, and consequences of tuberculosis were severe in those patients who consulted late. (author)

  5. Bidirectional communication using delay coupled chaotic directly ...

    Indian Academy of Sciences (India)

    Isochronal synchronization; bidirectional communication; directly modulated semiconductor lasers; delayed optoelectronic feedback. ... Sophisticated Test and Instrumentation Centre; Cochin University of Science and Technology, Cochin 682 022, India; International School of Photonics, Cochin University of Science and ...

  6. Delay Tolerant Routing with OLSRv2

    OpenAIRE

    Clausen, Thomas Heide; Herberg, Ulrich

    2011-01-01

    This memorandum proposes a simple mechanism for enabling basic delay tolerant networking with off-the-shelf MANET routing protocols - with the objective being to enable trading off slightly longer data delivery delays against resilience to a temporary lack of connectivity between a router and the ultimate destination of an IP datagram. As part of testing the benefit of said mechanism, an extreme network mobility model is proposed, entitled the "PopUp model": a router appears in the network, a...

  7. The Strategic Perils of Delayed Differentiation

    OpenAIRE

    Krishnan S. Anand; Karan Girotra

    2007-01-01

    The value of delayed differentiation (also known as postponement) for a monopolist has been extensively studied in the operations literature. We analyze the case of (imperfectly) competitive markets with demand uncertainty, wherein the choice of supply chain configuration (i.e., early or delayed differentiation) is endogenous to the competing firms. We characterize firms' choices in equilibrium and analyze the effects of these choices on quantities sold, profits, consumer surplus, and welfare...

  8. Delayed sleep onset in depressed young people.

    Science.gov (United States)

    Glozier, Nicholas; O'Dea, Bridianne; McGorry, Patrick D; Pantelis, Christos; Amminger, Günter Paul; Hermens, Daniel F; Purcell, Rosemary; Scott, Elizabeth; Hickie, Ian B

    2014-02-08

    The circadian abnormality of delayed sleep phase has been suggested to characterise a subgroup of depressed young adults with different risk factors and course of illness. We aim to assess the prevalence and factors, particularly substance use, associated with such delay in a large help-seeking cohort of young people with mental health problems. From a consecutively recruited sample of 802 help-seeking young people, 305 (38%) had at least moderate depressive symptoms (QIDS-C16 >10), sleep data and did not have a chronic severe mental illness. Demographic and clinical characteristics were evaluated through self report and clinical interview. Delayed sleep phase was defined as a sleep onset between the hours of 02:00 a.m. - 06:00 a.m. and the characteristics of this group were compared to normal phase sleepers. Delayed sleep onset was reported amongst 18% (n = 56/305) of the depressed group compared to 11% of the non-depressed young people. Amongst the depressed group, delayed sleep onset was associated with tobacco, alcohol and cannabis misuse and short sleep duration (x̅: 5.8 hrs vs. x̅: 7.8 hrs). There were no differences in demographic factors, personality traits or symptoms. Tobacco smoking was very common: In logistic regression analyses only tobacco use (OR 2.28, 95% CI: 1.04 - 5.01) was associated with delayed sleep onset. There was no interaction with age. Delayed sleep onset was twice as common in depressed young people as the general population and young people with other mental health problems, and is a potential marker for a subgroup of mood disorders. Those with delayed sleep onset were not more severely depressed but had short sleep duration, a risk for chronic psychological ill health, and higher levels of tobacco use. Nicotine use was common in this group, has biological evidence as a sleep disrupter, and requires specifically addressing in this population.

  9. Nonlinear Cournot duopoly with implementation delays

    International Nuclear Information System (INIS)

    Matsumoto, Akio; Szidarovszky, Ferenc

    2015-01-01

    We study the effects of two delays on the local as well as on global stability of nonlinear Cournot duopoly dynamics. The two major findings are an analytical construction of the stability switching curve on which stability is lost and the numerical confirmation of the birth of aperiodic global dynamics when the stationary state is locally unstable. The delays matters and can generate various dynamics ranging from simple to complicated dynamics.

  10. Diagnosis delay in Libyan female breast cancer

    Directory of Open Access Journals (Sweden)

    Ermiah Eramah

    2012-08-01

    Full Text Available Abstract Aims To study the diagnosis delay and its impact on stage of disease among women with breast cancer on Libya. Methods 200 women, aged 22 to 75 years with breast cancer diagnosed during 2008–2009 were interviewed about the period from the first symptoms to the final histological diagnosis of breast cancer. This period (diagnosis time was categorized into 3 periods: 6 months. If diagnosis time was longer than 3 months, the diagnosis was considered delayed (diagnosis delay. Consultation time was the time taken to visit the general practitioner after the first symptoms. Retrospective preclinical and clinical data were collected on a form (questionnaire during an interview with each patient and from medical records. Results The median of diagnosis time was 7.5 months. Only 30.0% of patients were diagnosed within 3 months after symptoms. 14% of patients were diagnosed within 3–6 months and 56% within a period longer than 6 months. A number of factors predicted diagnosis delay: Symptoms were not considered serious in 27% of patients. Alternative therapy (therapy not associated with cancer was applied in 13.0% of the patients. Fear and shame prevented the visit to the doctor in 10% and 4.5% of patients, respectively. Inappropriate reassurance that the lump was benign was an important reason for prolongation of the diagnosis time. Diagnosis delay was associated with initial breast symptom(s that did not include a lump (p  Diagnosis delay was associated with bigger tumour size (p Conclusions Diagnosis delay is very serious problem in Libya. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer awareness and training of general practitioners to reduce breast cancer mortality by promoting early detection. The treatment guidelines should pay more attention to the early phases of breast cancer. Especially, guidelines for good practices in managing

  11. Delaying gratification depends on social trust

    OpenAIRE

    Michaelson, Laura; de la Vega, Alejandro; Chatham, Christopher H.; Munakata, Yuko

    2013-01-01

    Delaying gratification is hard, yet predictive of important life outcomes, such as academic achievement and physical health. Prominent theories focus on the role of self-control, hypersensitivity to immediate rewards, and the cost of time spent waiting. However, delaying gratification may also require trust in people delivering future rewards as promised. To test the role of social trust, participants were presented with character vignettes and faces that varied in trustworthiness, and the...

  12. Time delay in a multichannel formalism

    International Nuclear Information System (INIS)

    Haberzettl, Helmut; Workman, Ron

    2007-01-01

    We reexamine the time-delay formalism of Wigner, Eisenbud, and Smith, which was developed to analyze both elastic and inelastic resonances. An error in the paper of Smith has propagated through the literature. We correct this error and show how the results of Eisenbud and Smith are related. We also comment on some recent time-delay studies, based on Smith's erroneous interpretation of the Eisenbud result

  13. Responsible conduct of research

    CERN Document Server

    Shamoo, Adil E

    2015-01-01

    Since the early 2000s, the field of Responsible Conduct of Research has become widely recognized as essential to scientific education, investigation, and training. At present, research institutions with public funding are expected to have some minimal training and education in RCR for their graduate students, fellows and trainees. These institutions also are expected to have a system in place for investigating and reporting misconduct in research or violations of regulations in research with human subjects, or in their applications to federal agencies for funding. Public scrutiny of the conduct of scientific researchers remains high. Media reports of misconduct scandals, biased research, violations of human research ethics rules, and moral controversies in research occur on a weekly basis. Since the 2009 publication of the 2nd edition of Shamoo and Resnik's Responsible Conduct of Research, there has been a vast expansion in the information, knowledge, methods, and diagnosis of problems related to RCR and the ...

  14. Longitudinal and reciprocal relations between delay discounting and crime.

    Science.gov (United States)

    Lee, Christine A; Derefinko, Karen J; Milich, Richard; Lynam, Donald R; DeWall, C Nathan

    2017-06-01

    Theorists argue that self-control failure is the underlying cause of criminal behavior, with previous research linking poor self-control to delinquency and drug use. The path from self-control to crime is well-established, but less is known about whether criminal behavior contributes to self-control deficits over time. We investigated bi-directional relations between self-control assessed via a delay discounting task and self-reported crime over a three-year period. During their first, second (73.38% retention rate), and third (63.12% retention rate) years of college, 526 undergraduates completed a delay discounting task and reported on their criminal behavior. In order to maximize variability, participants with conduct problems were overrecruited, comprising 23.1% of the final sample. As expected, more discounting of hypothetical monetary rewards significantly predicted future property crime across a one and two-year period, even when controlling for initial levels of both. This study also demonstrated evidence of a bi-directional relationship; violent crime predicted higher rates of delay discounting one year later. These results suggest that bi-directional relations exist between self-control and types of crime.

  15. Delay to orthopedic consultation for isolated limb injury

    Science.gov (United States)

    Rouleau, Dominique M.; Feldman, Debbie Ehrmann; Parent, Stefan

    2009-01-01

    ABSTRACT OBJECTIVE To describe referral mechanisms for referral to orthopedic surgery for isolated limb injuries in a public health care system and to identify factors affecting access. DESIGN Cross-sectional survey. SETTING Orthopedic surgery service in a level 1 trauma centre in Montreal, Que. PARTICIPANTS We conducted a prospective study of 166 consecutive adults (mean age 48 years) referred to orthopedic surgery for isolated limb injuries during a 4-month period. MAIN OUTCOME MEASURES Self-reported data on the nature of the trauma, the elapsed time between injury and orthopedic consultation, the number and type of previous primary care consultations, sociodemographic characteristics, and the level of satisfaction with care. RESULTS Average time between the injury and orthopedic consultation was 89 hours (range 3 to 642), with an average of 68 hours (range 0 to 642) for delay between primary care consultation and orthopedic consultation. A total of 36% of patients with time-sensitive diagnoses had unacceptable delays to orthopedic consultation according to the Quebec Orthopaedic Association guidelines. Lower limb injury, consulting first at another hospital, living far from the trauma centre, patient perception of low severity, and having a soft tissue injury were associated with longer delays. CONCLUSION Identifying gaps and risk factors for slower access might help improve referral mechanisms for orthopedic consultation. PMID:19826162

  16. Natures of Conduct

    DEFF Research Database (Denmark)

    Sielemann, Rasmus Basse

    Natures of Conduct explores the rationalities, practices and techniques of government processes in the Danish West Indies in the period between the late eighteenth century to the end of Danish colonial rule in 1917. In doing so, it engages Michel Foucault’s concepts of governmentality and the ‘di......Natures of Conduct explores the rationalities, practices and techniques of government processes in the Danish West Indies in the period between the late eighteenth century to the end of Danish colonial rule in 1917. In doing so, it engages Michel Foucault’s concepts of governmentality...

  17. Conducting metal dithiolate complexes

    DEFF Research Database (Denmark)

    Underhill, A. E.; Ahmad, M. M.; Turner, D. J.

    1985-01-01

    Further work on the chemical composition of the one-dimensional metallic metal dithiolene complex Li-Pt(mnt) is reported. The electrical conduction and thermopower properties of the nickel and palladium complexes are reported and compared with those of the platinum compound......Further work on the chemical composition of the one-dimensional metallic metal dithiolene complex Li-Pt(mnt) is reported. The electrical conduction and thermopower properties of the nickel and palladium complexes are reported and compared with those of the platinum compound...

  18. Graphene Conductance Uniformity Mapping

    DEFF Research Database (Denmark)

    Buron, Jonas Christian Due; Petersen, Dirch Hjorth; Bøggild, Peter

    2012-01-01

    We demonstrate a combination of micro four-point probe (M4PP) and non-contact terahertz time-domain spectroscopy (THz-TDS) measurements for centimeter scale quantitative mapping of the sheet conductance of large area chemical vapor deposited graphene films. Dual configuration M4PP measurements...... of less than a minute for a 4-in. wafer. The combination of M4PP and THz-TDS conductance measurements, supported by micro Raman spectroscopy and optical imaging, reveals that the film is electrically continuous on the nanoscopic scale with microscopic defects likely originating from the transfer process...

  19. The reasons for delay lumbar puncture

    Directory of Open Access Journals (Sweden)

    MH. Lotfi

    2017-04-01

    Full Text Available Early diagnosis of meningitis and encephalitis and prompt initiation of appropriate therapy is vital and any delay will lead to high mortality and serious and permanent morbidity. The main purpose of this study was to evaluate the management of 220 patients with suspected central nervous system (CNS infections (meningitis and encephalitis to determine the percentage of patients’ suspected CNS infection undergo lumbar puncture in acceptable time (in accordance with conventional algorithms. In this descriptive study, patients with suspected CNS infections admitted to Bu-Ali and Qods hospitals, in the period July 2013 to December 2015 were studied. Information of 220 patients was collected. Continuous variables were summarized as means ± standard deviation and categorical variables as frequencies and percentages. Lumbar puncture (LP in patients was delayed in 200 cases (91%. Most common causes of delay in performing LP were prolongation of the process of determining patient needs to puncture, satisfying patients, CT scan delay and the delay in allowing LP by neurologist. In this study, delaying LP rate was higher than other studies. It seems certain pattern in assistants’ visits for counseling. CT requests and neurologic consultation before LP performed for all adult patients.

  20. Efficient semiclassical approach for time delays

    Science.gov (United States)

    Kuipers, Jack; Savin, Dmitry V.; Sieber, Martin

    2014-12-01

    The Wigner time delay, defined by the energy derivative of the total scattering phase shift, is an important spectral measure of an open quantum system characterizing the duration of the scattering event. It is proportional to the trace of the Wigner-Smith matrix Q that also encodes other time-delay characteristics. For chaotic cavities, these quantities exhibit universal fluctuations that are commonly described within random matrix theory. Here, we develop a new semiclassical approach to the time-delay matrix which is formulated in terms of the classical trajectories that connect the exterior and interior regions of the system. This approach is superior to previous treatments because it avoids the energy derivative. We demonstrate the method's efficiency by going beyond previous work in establishing the universality of time-delay statistics for chaotic cavities with perfectly connected leads. In particular, the moment generating function of the proper time-delays (eigenvalues of Q) is found semiclassically for the first five orders in the inverse number of scattering channels for systems with and without time-reversal symmetry. We also show the equivalence of random matrix and semiclassical results for the second moments and for the variance of the Wigner time delay at any channel number.

  1. Lag synchronization of chaotic systems with time-delayed linear ...

    Indian Academy of Sciences (India)

    delayed linear terms via impulsive control is investigated. Based on the stability theory of impulsive delayed differen- tial equations, some sufficient conditions are obtained guaranteeing the synchronized behaviours between two delayed chaotic ...

  2. Virtual unit delay for digital frequency adaptive T/4 delay phase-locked loop system

    DEFF Research Database (Denmark)

    Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede

    2016-01-01

    /processor with a fixed sampling rate considering the cost and complexity, where the number of unit delays that have been adopted should be an integer. For instance, in conventional digital control systems, a single-phase T/4 Delay Phase-Locked Loop (PLL) system takes 50 unit delays (i.e., in a 50-Hz system...... Delay PLL system should be done in its implementation. This process will result in performance degradation in the digital control system, as the exactly required number of delays is not realized. Hence, in this paper, a Virtual Unit Delay (VUD) has been proposed to address such challenges to the digital......Digital micro-controllers/processors enable the cost-effective control of grid-connected power converter systems in terms of system monitoring, signal processing (e.g., grid synchronization), control (e.g., grid current and voltage control), etc. Normally, the control is implemented in a micro-controller...

  3. New code of conduct

    CERN Multimedia

    Laëtitia Pedroso

    2010-01-01

    During his talk to the staff at the beginning of the year, the Director-General mentioned that a new code of conduct was being drawn up. What exactly is it and what is its purpose? Anne-Sylvie Catherin, Head of the Human Resources (HR) Department, talked to us about the whys and wherefores of the project.   Drawing by Georges Boixader from the cartoon strip “The World of Particles” by Brian Southworth. A code of conduct is a general framework laying down the behaviour expected of all members of an organisation's personnel. “CERN is one of the very few international organisations that don’t yet have one", explains Anne-Sylvie Catherin. “We have been thinking about introducing a code of conduct for a long time but lacked the necessary resources until now”. The call for a code of conduct has come from different sources within the Laboratory. “The Equal Opportunities Advisory Panel (read also the "Equal opportuni...

  4. High Thermal Conductivity Materials

    CERN Document Server

    Shinde, Subhash L

    2006-01-01

    Thermal management has become a ‘hot’ field in recent years due to a need to obtain high performance levels in many devices used in such diverse areas as space science, mainframe and desktop computers, optoelectronics and even Formula One racing cars! Thermal solutions require not just taking care of very high thermal flux, but also ‘hot spots’, where the flux densities can exceed 200 W/cm2. High thermal conductivity materials play an important role in addressing thermal management issues. This volume provides readers a basic understanding of the thermal conduction mechanisms in these materials and discusses how the thermal conductivity may be related to their crystal structures as well as microstructures developed as a result of their processing history. The techniques for accurate measurement of these properties on large as well as small scales have been reviewed. Detailed information on the thermal conductivity of diverse materials including aluminum nitride (AlN), silicon carbide (SiC), diamond, a...

  5. CERN Code of Conduct

    CERN Document Server

    Department, HR

    2010-01-01

    The Code is intended as a guide in helping us, as CERN contributors, to understand how to conduct ourselves, treat others and expect to be treated. It is based around the five core values of the Organization. We should all become familiar with it and try to incorporate it into our daily life at CERN.

  6. Transient Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of transient heat conduction.Fourier's law. General heat conducation equation. Thermal diffusivity. Biot and Fourier numbers. Lumped analysis and time constant. Semi-infinite body: fixed surface temperature, convective heat transfer at the surface, or constant surface heat flux...

  7. Pressure dependence of conductivity

    International Nuclear Information System (INIS)

    Bracewell, B.L.; Hochheimer, H.D.

    1993-01-01

    The overall objectives of this work were to attempt the following: (1) Measure the pressure dependence of the electrical conductivity of several quasi-one-dimensional, charge-density-wave solids, including measurements along various crystal directions. (2) Measure photocurrents in selected MX solids at ambient and elevated pressures. (3) Measure the resonance Raman spectra for selected MX solids as a function of pressure

  8. Conducting and insulating materials

    OpenAIRE

    Bolotinha, Manuel

    2016-01-01

    Conducting materials may be classified into three groups: conductors, semiconductors and imperfect insulators. This section will cover only conductors. In general, metals and alloys are conductors of electricity. The most common metals used in electricity are copper, aluminium and their alloys. info:eu-repo/semantics/publishedVersion

  9. Conducting Educational Design Research

    Science.gov (United States)

    McKenney, Susan; Reeves, Thomas

    2012-01-01

    Educational design research blends scientific investigation with systematic development and implementation of solutions to educational problems. Empirical investigation is conducted in real learning settings--not laboratories--to craft usable and effective solutions. At the same time, the research is carefully structured to produce theoretical…

  10. Conduct Disorder and Comorbidity.

    Science.gov (United States)

    Stahl, Nicole D.; Clarizio, Harvey F.

    1999-01-01

    Provides critical examination of research published during past ten years addressing Conduct Disorder (CD), Attention Deficit Hyperactivity Disorder, Oppositional Defiant Disorder (ODD), and internalizing disorders. Concludes comorbidity varies with age, gender, informant, diagnostic criteria, and nature of the sample. Implications of comorbidity…

  11. Thermal conductivity of metals

    Science.gov (United States)

    Kazem, Sayyed M.

    1990-01-01

    The objective is to familiarize students with steady and unsteady heat transfer by conduction and with the effect of thermal conductivity upon temperature distribution through a homogeneous substance. The elementary heat conduction experiment presented is designed for associate degree technology students in a simple manner to enhance their intuition and to clarify many confusing concepts such as temperature, thermal energy, thermal conductivity, heat, transient and steady flows. The equipment set is safe, small, portable (10 kg) and relatively cheap (about $1200): the electric hot plate 2 kg (4.4 lb) for $175: the 24 channel selector and Thermocouple Digital Readout (Trendicator) 4.5 kg (10 lb) for about $1000; the three metal specimens (each of 2.5 cm diameter and 11 cm length), base plate and the bucket all about 3 kg (7 lb) for about $25. The experiment may take from 60 to 70 minutes. Although the hot plate surface temperature could be set from 90 to 370 C (maximum of 750 watts) it is a good practice to work with temperatures of 180 to 200 C (about 400 watts). They may experiment in squads of 2, 3 or even 4, or the instructor may demonstrate it for the whole class.

  12. Conducting carbonized polyaniline nanotubes

    Czech Academy of Sciences Publication Activity Database

    Mentus, S.; Ciric-Marjanovic, G.; Trchová, Miroslava; Stejskal, Jaroslav

    2009-01-01

    Roč. 20, č. 24 (2009), 245601/1-245601/10 ISSN 0957-4484 R&D Projects: GA ČR GA203/08/0686; GA AV ČR IAA400500905 Institutional research plan: CEZ:AV0Z40500505 Keywords : conducting polymers * polyaniline * carbonization Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.137, year: 2009

  13. Electrical Conduction and Superconductivity

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 9. Electrical Conduction and Superconductivity. Suresh V Vettoor. General Article Volume 8 Issue 9 September 2003 pp 41-48. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/09/0041-0048 ...

  14. Optimal Control with Time Delays via the Penalty Method

    Directory of Open Access Journals (Sweden)

    Mohammed Benharrat

    2014-01-01

    Full Text Available We prove necessary optimality conditions of Euler-Lagrange type for a problem of the calculus of variations with time delays, where the delay in the unknown function is different from the delay in its derivative. Then, a more general optimal control problem with time delays is considered. Main result gives a convergence theorem, allowing us to obtain a solution to the delayed optimal control problem by considering a sequence of delayed problems of the calculus of variations.

  15. Determinants of developmental delay in infants aged 12 months.

    Science.gov (United States)

    Slykerman, Rebecca F; Thompson, John M D; Clark, Phillipa M; Becroft, David M O; Robinson, Elizabeth; Pryor, Jan E; Wild, Chris J; Mitchell, Edwin A

    2007-03-01

    The aim of this study was to determine which demographic, maternal, obstetric and postnatal variables were associated with achievement of developmental milestones at the age of 12 months in term infants. Mothers and babies were enrolled in the Auckland Birthweight Collaborative Study shortly after birth. All infants were full term (gestation >or= 37 weeks). Approximately half of the sample were small for gestational age (SGA = birthweight 10th percentile). A maternal interview was conducted soon after birth. Phase 2 of the study occurred 12 months later when mothers were sent a postal questionnaire requesting information about the child's health and development during the first year of life using the Denver Prescreening Developmental Questionnaire. Seven hundred and forty-four (85.4%) European mothers returned the postal questionnaire. SGA children were not at increased risk of developmental delay at 12 months of age. In a sample representative of New Zealand European children, after adjustment for the effects of potential confounders, maternal smoking during pregnancy (OR = 2.1 [95% CI 1.1, 4.0]), maternal smoking during the first year of life (OR = 1.9 [95% CI 1.0, 3.8]) and low levels of satisfaction with parenting (OR = 2.4 [95% CI 1.1, 5.2]) were associated with significantly increased risk of developmental delay. In the subgroup of SGA children, maternal smoking during pregnancy (OR = 2.9 [95% CI 1.4, 6.2]), high levels of stress associated with parenting (OR = 2.2 [95% CI 1.2, 4.0]), and low levels of satisfaction with parenting (OR = 4.3 [95% CI 1.3, 13.5]) were significantly associated with developmental delay after adjustment for the effects of potential confounders. In conclusion, maternal and postnatal factors were better predictors of developmental delay than demographic variables.

  16. Relation between early motor delay and later communication delay in infants at risk for autism.

    Science.gov (United States)

    Bhat, A N; Galloway, J C; Landa, R J

    2012-12-01

    Motor delays have been reported in retrospective studies of young infants who later develop Autism Spectrum Disorders (ASDs). In this study, we prospectively compared the gross motor development of a cohort at risk for ASDs; infant siblings of children with ASDs (AU sibs) to low risk typically developing (LR) infants. 24 AU sibs and 24 LR infants were observed at 3 and 6 months using a standardized motor measure, the Alberta Infant Motor Scale (AIMS). In addition, as part of a larger study, the AU sibs also received a follow-up assessment to determine motor and communication performance at 18 months using the Mullen Scales of Early Learning. Significantly more AU sibs showed motor delays at 3 and 6 months than LR infants. The majority of the AU sibs showed both early motor delays and later communication delays. Small sample size and limited follow-up. Early motor delays are more common in AU sibs than LR infants. Communication delays later emerged in 67-73% of the AU sibs who had presented with early motor delays. Overall, early motor delays may be predictive of future communication delays in children at risk for autism. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Derivation and computation of discrete-delay and continuous-delay SDEs in mathematical biology.

    Science.gov (United States)

    Allen, Edward J

    2014-06-01

    Stochastic versions of several discrete-delay and continuous-delay differential equations, useful in mathematical biology, are derived from basic principles carefully taking into account the demographic, environmental, or physiological randomness in the dynamic processes. In particular, stochastic delay differential equation (SDDE) models are derived and studied for Nicholson's blowflies equation, Hutchinson's equation, an SIS epidemic model with delay, bacteria/phage dynamics, and glucose/insulin levels. Computational methods for approximating the SDDE models are described. Comparisons between computational solutions of the SDDEs and independently formulated Monte Carlo calculations support the accuracy of the derivations and of the computational methods.

  18. Apparatus and Method for Compensating for Process, Voltage, and Temperature Variation of the Time Delay of a Digital Delay Line

    Science.gov (United States)

    Seefeldt, James (Inventor); Feng, Xiaoxin (Inventor); Roper, Weston (Inventor)

    2013-01-01

    A process, voltage, and temperature (PVT) compensation circuit and a method of continuously generating a delay measure are provided. The compensation circuit includes two delay lines, each delay line providing a delay output. The two delay lines may each include a number of delay elements, which in turn may include one or more current-starved inverters. The number of delay lines may differ between the two delay lines. The delay outputs are provided to a combining circuit that determines an offset pulse based on the two delay outputs and then averages the voltage of the offset pulse to determine a delay measure. The delay measure may be one or more currents or voltages indicating an amount of PVT compensation to apply to input or output signals of an application circuit, such as a memory-bus driver, dynamic random access memory (DRAM), a synchronous DRAM, a processor or other clocked circuit.

  19. The discourse of health managers on aspects related to the delay in tuberculosis diagnosis

    Directory of Open Access Journals (Sweden)

    Lenilde Duarte de Sa

    2013-10-01

    Full Text Available The aim of this study was to analyze the discourse of health managers on aspects related to delay in tuberculosis diagnosis. This was a qualitative research study, conducted with 16 Family Health Unit managers. The empirical data were obtained through semi-structured interviews. The analysis was based on the theoretical framework of the French school of discourse analysis. According to the managers’ statements, the delay in tuberculosis diagnosis is related to patient and health service aspects. As for patient aspects, managers report fear, prejudice and lack of information as factors that may promote a delayed diagnosis. Regarding health service aspects, structural problems and lack of professional skills were reported. The discourse of managers should be considered to qualify tuberculosis control actions and to prevent delays in diagnosis.

  20. [The discourse of health managers on aspects related to the delay in tuberculosis diagnosis].

    Science.gov (United States)

    de Sá, Lenilde Duarte; Barrêto, Anne Jaquelyne Roque; Nogueira, Jordana de Almeida; Cunha, Fátima Teresinha Scarparo; Palha, Pedro Fredemir; Villa, Tereza Cristina Scatena

    2013-10-01

    The aim of this study was to analyze the discourse of health managers on aspects related to delay in tuberculosis diagnosis. This was a qualitative research study, conducted with 16 Family Health Unit managers. The empirical data were obtained through semi-structured interviews. The analysis was based on the theoretical framework of the French school of discourse analysis. According to the managers' statements, the delay in tuberculosis diagnosis is related to patient and health service aspects. As for patient aspects, managers report fear, prejudice and lack of information as factors that may promote a delayed diagnosis. Regarding health service aspects, structural problems and lack of professional skills were reported. The discourse of managers should be considered to qualify tuberculosis control actions and to prevent delays in diagnosis.

  1. Nanostructured conductive polymeric materials

    Science.gov (United States)

    Al-Saleh, Mohammed H.

    Conductive polymer composites (CPCs) are a suitable alternative to metals in many applications due to their light-weight, corrosion resistance, low cost, ease of processing and design flexibility. CPCs have been formulated using different types of conductive fillers. In this PhD thesis, the focus is on CPCs for electrostatic discharge (ESD) protection and electromagnetic interference (EMI) attenuation. Despite the versatility of conductive fillers, carbon black (CB) has been the dominant filler to make CPCs for ESD protection applications because CB/polymer composites have a cost advantage over all other CPCs. For EMI shielding, stainless steel fibres and metal coated fibers are the preferred fillers, however CPCs made of those fibers are not the dominant EMI shielding materials. Metal coated and polymer plated polymers are the most widely used EMI shielding options. The limited use of CPCs in the EMI shielding market is because the high filler loading required to formulate a composite with an adequate level of shielding remarkably increases the composite price. In order to increase the competitiveness of CPCs, percolation threshold should be minimized as much as possible and composites with high EMI shielding capabilities at low filler loading should be formulated because all conductive fillers are expensive compared to polymers. In this thesis, two different methodologies to reduce percolation threshold in CPCs have been successfully developed and a CPC with exceptional EMI shielding capability has been formulated using copper nanowires as conductive filler. The first percolation threshold reduction technique is based on the selective localization of CB at the interface of immiscible polymer blend. The technique requires adding a copolymer that prefers the blend's interface and for which CB nanoparticles has the highest affinity. The second method is based on producing a CPC powder and then using this powder as a conductive filler to produce composite by dry

  2. Electrical and Thermal Conductivity

    Science.gov (United States)

    Ventura, Guglielmo; Perfetti, Mauro

    After a Sect. 1.1 devoted to electrical conductivity and a section that deals with magnetic and dielectric losses ( 1.2 ), this chapter explores the theory of thermal conduction in solids. The examined categories of solids are: metals Sect. 1.3.2 , Dielectrics Sects. 1.3.3 and 1.3.4 and Nanocomposites Sect. 1.3.5 . In Sect. 1.3.6 the problem of thermal and electrical contact between materials is considered because contact resistance occurring at conductor joints in magnets or other high power applications can lead to undesirable electrical losses. At low temperature, thermal contact is also critical in the mounting of temperature sensors, where bad contacts can lead to erroneous results, in particular when superconductivity phenomena are involved.

  3. Super ionic conductive glass

    Science.gov (United States)

    Susman, S.; Volin, K.J.

    Described is an ionically conducting glass for use as a solid electrolyte in a power or secondary cell containing an alkali metal-containing anode and a cathode separated by an alkali metal ion conducting glass having an ionic transference number of unity and the general formula: A/sub 1 + x/D/sub 2-x/3/Si/sub x/P/sub 3 - x/O/sub 12 - 2x/3/, wherein A is a network modifier for the glass and is an alkali metal of the anode, D is an intermediate for the glass and is selected from the class consisting of Zr, Ti, Ge, Al, Sb, Be, and Zn and X is in the range of from 2.25 to 3.0. Of the alkali metals, Na and Li are preferred and of the intermediate, Zr, Ti and Ge are preferred.

  4. Transparent Conductive Nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    None

    2008-06-22

    The objectives of this program between UT-Battelle, LLC (the ''Contractor'') and (Battelle Memorial Institute) (the "Participant") were directed towards achieving significant improvement: in the electrical conductivity and optical/infrared transmission of single-wall carbon nanotube (SWNT)-based composite materials. These materials will be used in coating applications that range from aircraft canopies to display applications. The goal of the project was to obtain supported mats of SWNTs with sheet conductivities approaching 10 ohms/square combined with high optical transmission (>85% transmission at 550 nm), thereby permitting their application as a replacement for indium tin oxide (ITO) in a variety of applications such as flexible displays.

  5. Conducting Polymer Based Nanobiosensors

    Directory of Open Access Journals (Sweden)

    Chul Soon Park

    2016-06-01

    Full Text Available In recent years, conducting polymer (CP nanomaterials have been used in a variety of fields, such as in energy, environmental, and biomedical applications, owing to their outstanding chemical and physical properties compared to conventional metal materials. In particular, nanobiosensors based on CP nanomaterials exhibit excellent performance sensing target molecules. The performance of CP nanobiosensors varies based on their size, shape, conductivity, and morphology, among other characteristics. Therefore, in this review, we provide an overview of the techniques commonly used to fabricate novel CP nanomaterials and their biosensor applications, including aptasensors, field-effect transistor (FET biosensors, human sense mimicking biosensors, and immunoassays. We also discuss prospects for state-of-the-art nanobiosensors using CP nanomaterials by focusing on strategies to overcome the current limitations.

  6. Conductive Polymer Composites

    OpenAIRE

    Pierini, Filippo

    2013-01-01

    In recent years, nanotechnologies have led to the production of materials with new and sometimes unexpected qualities through the manipulation of nanoscale components. This research aimed primarily to the study of the correlation between hierarchical structures of hybrid organic-inorganic materials such as conductive polymer composites (CPCs). Using a bottom-up methodology, we could synthesize a wide range of inorganic nanometric materials with a high degree of homogeneity and purity, ...

  7. Conducting interactive experiments online.

    Science.gov (United States)

    Arechar, Antonio A; Gächter, Simon; Molleman, Lucas

    2018-01-01

    Online labor markets provide new opportunities for behavioral research, but conducting economic experiments online raises important methodological challenges. This particularly holds for interactive designs. In this paper, we provide a methodological discussion of the similarities and differences between interactive experiments conducted in the laboratory and online. To this end, we conduct a repeated public goods experiment with and without punishment using samples from the laboratory and the online platform Amazon Mechanical Turk. We chose to replicate this experiment because it is long and logistically complex. It therefore provides a good case study for discussing the methodological and practical challenges of online interactive experimentation. We find that basic behavioral patterns of cooperation and punishment in the laboratory are replicable online. The most important challenge of online interactive experiments is participant dropout. We discuss measures for reducing dropout and show that, for our case study, dropouts are exogenous to the experiment. We conclude that data quality for interactive experiments via the Internet is adequate and reliable, making online interactive experimentation a potentially valuable complement to laboratory studies.

  8. Factors associated with delays in treatment initiation after tuberculosis diagnosis in two districts of India.

    Directory of Open Access Journals (Sweden)

    Durba Paul

    Full Text Available BACKGROUND: Excessive time between diagnosis and initiation of tuberculosis (TB treatment contributes to ongoing TB transmission and should be minimized. In India, Revised National TB Control Programme (RNTCP focuses on indicator start of treatment within 7 days of diagnosis for patients with sputum smear-positive PTB for monitoring DOTS implementation. OBJECTIVES: To determine length of time between diagnosis and initiation of treatment and factors associated with delays of more than 7 days in smear-positive pulmonary TB. METHODS: Using existing programme records such as the TB Register, treatment cards, and the laboratory register, we conducted a retrospective cohort study of all patients with smear-positive pulmonary TB registered from July-September 2010 in two districts in India. A random sample of patients with pulmonary TB who experienced treatment delay of more than 7 days was interviewed using structured questionnaire. RESULTS: 2027 of 3411 patients registered with pulmonary TB were smear-positive. 711(35% patients had >7 days between diagnosis and treatment and 262(13% had delays >15 days. Mean duration between TB diagnosis and treatment initiation was 8 days (range = 0-128 days. Odds of treatment delay >7 days was 1.8 times more likely among those who had been previously treated (95% confidence interval [CI] 1.5-2.3 and 1.6 (95% CI 1.3-1.8 times more likely among those diagnosed in health facilities without microscopy centers. The main factors associated with a delay >7 days were: patient reluctance to start a re-treatment regimen, patients seeking second opinions, delay in transportation of drugs to the DOT centers and delay in initial home visits. To conclude, treatment delay >7 days was associated with a number of factors that included history of previous treatment and absence of TB diagnostic services in the local health facility. Decentralized diagnostic facilities and improved referral procedures may reduce such treatment

  9. Delayed presentation for care during acute myocardial infarction in a Hispanic population of Los Angeles County.

    Science.gov (United States)

    Henderson, Sean O; Magana, Renee N; Korn, Carrie S; Genna, Tammy; Bretsky, Philip M

    2002-01-01

    Delay in seeking care for acute myocardial infarction (AMI) has been well described in some populations, but little research has been conducted on delay by minority groups, such as Latinos and Asians. This study sought to determine the degree of delay and mode of access of patients with AMI presenting to an inner-city hospital serving an ethnically diverse population. This study was a retrospective case series of Latino, Asian, African-American and Caucasian patients diagnosed in the emergency department (ED) with chest pain (CP) and AMI, during a 2-year period. Three hundred thirty seven cases were studied, with the average delay in presentation for care being 44.3 hours, with a median of 8.8 hours. Before seeking care for symptoms of AMI, Latinos delayed an average of 41.5 hours (median 9.2 hours); African Americans delayed an average of 30.8 hours (median 3.5 hours); Asians delayed an average of 92 hours (median 12 hours); and Caucasians delayed an average of 31.6 hours (median 3.2 hours). The mode of transportation used by the different groups to travel to the ED was also significantly different, with Latinos and Asians utilizing private transportation the majority of the time (70% and 83%, respectively). There is a significant delay in presentation for care in patients experiencing AMI in Los Angeles County, greatest among the Asian and Latino populations. Once the decision to seek assistance is made, an under-utilization of EMS compounds the problem. Socioeconomic status, language, and cultural practices pose unique barriers to recognizing and addressing symptoms of AMI in this population.

  10. Survival analysis for predictive factors of delay vaccination in Iranian children

    Directory of Open Access Journals (Sweden)

    Abolfazl Mohammadbeigi

    2015-01-01

    Full Text Available Background: Today, beside immunization coverage the age appropriate vaccination is another helpful index in public health. Evidences have shown that high immunization coverage rates do not necessarily imply age-appropriate vaccination status. The current study aimed to show the predictive factors of delayed vaccination by survival models. Methods: A historical cohort study conducted on 3610 children aged between 24 and 47 months who was living in the suburbs of five big cities of Iran. Time of delay in vaccination of first dose of mumps-measles-rubella (MMR was calculated from date of vaccination minus age appropriate time according to vaccine card. Kaplan-Maier and Log rank tests were used for comparison the median of delay time. For controlling of confounding variables, multivariate cox model was used and hazard ratio with 95% confidence interval (95% was reported. Results: The mean ± standard deviation and median interquartile range of delay time was 38.34 ± 73.1 and 16 (11-31 days in delayed group. The Log rank test showed that city of living, nationality, parents′ education, and birth order are related with prolonged delay time in MMR vaccination (P 0.05. Cox regression showed that city of living, mother education, and nationality are the most predictive factors of delay time duration in MMR vaccination. Conclusions: Delay time duration of vaccination increased by faring from capital to the east south. Moreover, concentration of foreign immigrants in big cities and low level of mother education are the most predictors of delayed vaccination. Educational intervention should focus on immigrants and mothers with low education level.

  11. Semantic effects in sentence recall: the contribution of immediate vs delayed recall in language assessment.

    Science.gov (United States)

    Polišenská, Kamila; Chiat, Shula; Comer, Amanda; McKenzie, Kirsty

    2014-01-01

    Sentence recall is increasingly used to assess language. It is widely debated what the task is actually testing, but one rarely explored aspect is the contribution of semantics to sentence recall. The few studies that have examined the role of semantics in sentence recall have employed an 'intrusion paradigm', following Potter and Lombardi (1990), and their paradigm relies on interference errors with conclusions based on an analysis of error patterns. We have instead manipulated the semantic plausibility of whole sentences to investigate the effects of semantics on immediate and delayed sentence recall. In Study 1, adults recalled semantically plausible and implausible sentences either immediately or after distracter tasks varying in lexical retrieval demands (backward counting and picture naming). Results revealed significant effects of plausibility, delay, and a significant interaction indicating increasing reliance on semantics as the demands of the distracter tasks increased. Study 2, conducted with 6-year-old children, employed delay conditions that were modified to avoid floor effects (delay with silence and forward counting) and a similar pattern of results emerged. This novel methodology provided robust evidence showing the effectiveness of delayed recall in the assessment of semantics and the effectiveness of immediate recall in the assessment of morphosyntax. The findings from our study clarify the linguistic mechanisms involved in immediate and delayed sentence recall, with implications for the use of recall tasks in language assessment. The reader will be able to: (i) define the difference between immediate and delayed sentence recall and different types of distractors, (ii) explain the utility of immediate and delayed recall sentence recall in language assessment, (iii) discuss suitability of delayed recall for the assessment of semantics. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Ataxia telangiectasia: presentation and diagnostic delay.

    Science.gov (United States)

    Devaney, Rebecca; Pasalodos, Sara; Suri, Mohnish; Bush, Andy; Bhatt, Jayesh M

    2017-04-01

    Ataxia telangiectasia (A-T) is a rare progressive, multisystem genetic disease. Families of children with ultra-rare diseases often experience significant diagnostic delays. We reviewed the diagnostic process for A-T in order to identify causes of delay in an attempt to facilitate earlier identification of A-T in the future. A retrospective case note review of 79 children at the National Paediatric A-T clinic seen since May 2009. Data were collected on the nature and age of initial symptoms, the age at first presentation, measurement of alpha feto-protein (AFP) and age of genetic diagnostic confirmation. At presentation, 71 children (90%) had ataxia. The median presentation delay (from first parental concern to presentation) was 8 months (range 0-118 months), and the median diagnostic delay (genetic confirmation of diagnosis) was 12 months (range 1-109 months). There are significant delays in presentation and diagnostic confirmation of A-T. A greater awareness of A-T and early measurement of AFP may help to improve this. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  13. Delayed Station Blackout Event and Nuclear Safety

    Directory of Open Access Journals (Sweden)

    Andrija Volkanovski

    2015-01-01

    Full Text Available The loss of off-site power (LOOP event occurs when all electrical power to the nuclear power plant from the power grid is lost. Complete failure of both off-site and on-site alternating current (AC power sources is referred to as a station blackout (SBO. Combined LOOP and SBO events are analyzed in this paper. The analysis is done for different time delays between the LOOP and SBO events. Deterministic safety analysis is utilized for the assessment of the plant parameters for different time delays of the SBO event. Obtained plant parameters are used for the assessment of the probabilities of the functional events in the SBO event tree. The results show that the time delay of the SBO after the LOOP leads to a decrease of the core damage frequency (CDF from the SBO event tree. The reduction of the CDF depends on the time delay of the SBO after the LOOP event. The results show the importance of the safety systems to operate after the plant shutdown when the decay heat is large. Small changes of the basic events importance measures are identified with the introduction of the delay of the SBO event.

  14. Television viewing associates with delayed language development.

    Science.gov (United States)

    Chonchaiya, Weerasak; Pruksananonda, Chandhita

    2008-07-01

    To identify impact of television viewing on language development. The case-control study included 56 new patients with language delay and 110 normal children, aged 15-48 months. Language delay was diagnosed by reviewing language milestones and Denver-II. Television viewing variables and child/parental characteristics between both groups were interviewed. The data were analyzed by ANOVA and chi-square test. Adjusted odds ratios and 95% confidence intervals were calculated from multivariate logistic regression model. Forty-six boys and 10 girls; mean [+/-SD] age, 2.11+/-0.47 years of the case group and 59 boys and 51 girls; mean [+/-SD] age, 2.23+/-0.80 years of the control group were enrolled. Children who had language delay usually started watching television earlier at age 7.22+/-5.52 months vs. 11.92+/-5.86 months, p-valuetelevision than normal children (3.05+/-1.90 h/day vs. 1.85+/-1.18 h/day; p-valuetelevision attelevision>2 h/day were approximately six times more likely to have language delays. There is a relationship between early onset and high frequency of TV viewing and language delay.

  15. Delayed Reduction of Nasal Bone Fractures.

    Science.gov (United States)

    Yoon, Han Young; Han, Dong Gil

    2016-06-01

    Nasal bone fractures are managed by closed reduction within the 2-week period, and are managed by secondary correction after this time. There is little literature on the delayed reduction for nasal bone fractures beyond the 2-week duration. We report our experience with nasal fractures, which were reduced beyond this period. A retrospective review was performed for all patients who had undergone closed reduction of isolated nasal bone fracture. Patients were included for having undergone reduction of nasal bone fractures at or more than 2 weeks after the injury. Medical records were reviewed for demographic information, injury mechanism, fracture type, delay in treatment, and cause for delay. Postoperative outcomes were evaluated using computed tomography images. The review identified 10 patients. The average reduction time was 22.1 days. Five of patients underwent reduction between days 15 and 20, and the remaining five patients underwent reduction between days 21 and 41. The postoperative outcomes were excellent in 8 patients and good in 2 patients. Outcomes were superior for nasal fractures with displaced end plates and multiple fracture segments. Our study results appears to support delayed reduction of isolated nasal fractures in the presence of factors that delay bony reunion.

  16. Queues with Choice via Delay Differential Equations

    Science.gov (United States)

    Pender, Jamol; Rand, Richard H.; Wesson, Elizabeth

    Delay or queue length information has the potential to influence the decision of a customer to join a queue. Thus, it is imperative for managers of queueing systems to understand how the information that they provide will affect the performance of the system. To this end, we construct and analyze two two-dimensional deterministic fluid models that incorporate customer choice behavior based on delayed queue length information. In the first fluid model, customers join each queue according to a Multinomial Logit Model, however, the queue length information the customer receives is delayed by a constant Δ. We show that the delay can cause oscillations or asynchronous behavior in the model based on the value of Δ. In the second model, customers receive information about the queue length through a moving average of the queue length. Although it has been shown empirically that giving patients moving average information causes oscillations and asynchronous behavior to occur in U.S. hospitals, we analytically and mathematically show for the first time that the moving average fluid model can exhibit oscillations and determine their dependence on the moving average window. Thus, our analysis provides new insight on how operators of service systems should report queue length information to customers and how delayed information can produce unwanted system dynamics.

  17. Fuzzy delay model based fault simulator for crosstalk delay fault test ...

    Indian Academy of Sciences (India)

    In this paper, the fuzzy delay model is employed for test generation of crosstalk delay faults in ... Section 2 reviews the previous works on test generation and simulation of asynchronous sequential circuits. ...... Takahashi H, Keller K J, Le K T, Saluja K K and Takamatsu Y 2005 A Method for Reducing the Target. Fault list of ...

  18. Communication key using delay times in time-delayed chaos synchronization

    International Nuclear Information System (INIS)

    Kim, Chil-Min; Kye, Won-Ho; Rim, Sunghwan; Lee, Soo-Young

    2004-01-01

    We propose an efficient key scheme, which can generate a great number of communication keys, for communication using chaos synchronization. We have attained the keys from delay times of time-delay coupled chaotic systems. We explain the scheme and the efficiency by coupling Henon and logistic maps and illustrate them by coupling Navier-Stokes and Lorenz equations as a continuous system

  19. Thermal contact conductance

    CERN Document Server

    Madhusudana, Chakravarti V

    2013-01-01

    The work covers both theoretical and practical aspects of thermal contact conductance. The theoretical discussion focuses on heat transfer through spots, joints, and surfaces, as well as the role of interstitial materials (both planned and inadvertent). The practical discussion includes formulae and data that can be used in designing heat-transfer equipment for a variety of joints, including special geometries and configurations. All of the material has been updated to reflect the latest advances in the field.

  20. Thermal Conductivity of Soils

    Science.gov (United States)

    1977-07-01

    screen), percent SLeir Clayr ?in Fine Middels Medium cGrov Coarse Grua Gravel Stein Rock U.S. Standard sikt US Standard screen (measure) Best p! i...SPES. VEI,:T kg/m3 Spec. weight kg/m3 TORR R. VEKT Dry density POROSITET Porosity LEDN. EVNE \\V/mK Conductivity W/mI, Tyholt leire TyholtI) clay...8217 TABLE I. B. CRUSHED ROCK MATERIALS. MATERIALE Material KVARTSINNH. % quartz content % SPEC. VEKT kg/m 3 Spec. weight % TORR R. VEKT Dry

  1. 'Stuffed' conducting polymers

    DEFF Research Database (Denmark)

    Winther-Jensen, Bjørn; Chen, Jun; West, Keld

    2005-01-01

    Conducting polymers (CP) obtained by oxidative polymerization using iron(III) salts shrink when Fe(II) and the excess counter ions are washed out after polymerization. This phenomenon can be used to incorporate active molecules into the CP matrix via their addition to the wash liquid. In the pres....... In the present work we demonstrate this principle on three different CP's: polypyrrole (PPy), poly-terthiophene (PTTh) and poly(3,4-ethylenedioxy thiophene) (PEDT), using ferrocene as a model molecule to be trapped in the polymer films. (c) 2005 Elsevier Ltd. All rights reserved....

  2. On stochastic differential equations with random delay

    International Nuclear Information System (INIS)

    Krapivsky, P L; Luck, J M; Mallick, K

    2011-01-01

    We consider stochastic dynamical systems defined by differential equations with a uniform random time delay. The latter equations are shown to be equivalent to deterministic higher-order differential equations: for an nth-order equation with random delay, the corresponding deterministic equation has order n + 1. We analyze various examples of dynamical systems of this kind, and find a number of unusual behaviors. For instance, for the harmonic oscillator with random delay, the energy grows as exp((3/2) t 2/3 ) in reduced units. We then investigate the effect of introducing a discrete time step ε. At variance with the continuous situation, the discrete random recursion relations thus obtained have intrinsic fluctuations. The crossover between the fluctuating discrete problem and the deterministic continuous one as ε goes to zero is studied in detail on the example of a first-order linear differential equation

  3. Delay time and tunneling transient phenomena

    International Nuclear Information System (INIS)

    Garcia-Calderon, Gaston; Villavicencio, Jorge

    2002-01-01

    Analytic solutions to the time-dependent Schroedinger equation for cutoff wave initial conditions are used to investigate the time evolution of the transmitted probability density for tunneling. For a broad range of values of the potential barrier opacity α, we find that the probability density exhibits two evolving structures. One refers to the propagation of a forerunner related to a time domain resonance [Phys. Rev. A 64, 0121907 (2001)], while the other consists of a semiclassical propagating wave front. We find a regime where the forerunners are absent, corresponding to positive time delays, and show that this regime is characterized by opacities α c . The critical opacity α c is derived from the analytical expression for the delay time, which reflects a link between transient effects in tunneling and the delay time

  4. Time-delayed autosynchronous swarm control.

    Science.gov (United States)

    Biggs, James D; Bennet, Derek J; Dadzie, S Kokou

    2012-01-01

    In this paper a general Morse potential model of self-propelling particles is considered in the presence of a time-delayed term and a spring potential. It is shown that the emergent swarm behavior is dependent on the delay term and weights of the time-delayed function, which can be set to induce a stationary swarm, a rotating swarm with uniform translation, and a rotating swarm with a stationary center of mass. An analysis of the mean field equations shows that without a spring potential the motion of the center of mass is determined explicitly by a multivalued function. For a nonzero spring potential the swarm converges to a vortex formation about a stationary center of mass, except at discrete bifurcation points where the center of mass will periodically trace an ellipse. The analytical results defining the behavior of the center of mass are shown to correspond with the numerical swarm simulations.

  5. Abdominal CT findings of delayed postoperative complications

    Energy Technology Data Exchange (ETDEWEB)

    Zissin, R.; Osadchy, A. [Sapir Medical Center, Dept. of Diagnostic Imaging, Kfar Saba (Israel)]. E-mail: zisinrivka@clalit.org.il; Gayer, G. [Assaf Harofe Medical Center, Dept. of Diagnostic Imaging, Zrifin (Israel)

    2007-10-15

    Despite progress in surgical techniques and modern medical treatment, postoperative complications occur not infrequently and vary according to type of surgery, clinical setting, and time elapsed since surgery. In general, they can be divided into early and delayed complications. Delayed postoperative complications can be classified as specific and nonspecific. The common nonspecific delayed complications are incisional hernia and postoperative bowel obstruction. Bowel obstruction can be further categorized as obstruction related to benign or neoplastic etiology, the latter occurring in oncology patients in whom the primary surgery was related to an underlying abdominal neoplasm. Gossypiboma is another, fortunately rare, postoperative complication. Specific complications appear after specific operations and include the following: Splenosis - following splenectomy. Retained gallstones and spilled gallstones - following cholecystectomy, mainly laparoscopic. Dropped appendicolith and stump appendicitis - following appendectomy, mainly laparoscopic. Obturation obstruction by a bezoar - following gastric surgery. Afferent loop syndrome (ALS) - following Bilroth II gastrectomy. (author)

  6. Relation between delayed feedback and delay-coupled systems and its application to chaotic lasers

    Energy Technology Data Exchange (ETDEWEB)

    Soriano, Miguel C., E-mail: miguel@ifisc.uib-csic.es; Flunkert, Valentin; Fischer, Ingo [Instituto de Física Interdisciplinar y Sistemas Complejos, IFISC (CSIC-UIB), Campus Universitat Illes Balears, E-07122 Palma de Mallorca (Spain)

    2013-12-15

    We present a systematic approach to identify the similarities and differences between a chaotic system with delayed feedback and two mutually delay-coupled systems. We consider the general case in which the coupled systems are either unsynchronized or in a generally synchronized state, in contrast to the mostly studied case of identical synchronization. We construct a new time-series for each of the two coupling schemes, respectively, and present analytic evidence and numerical confirmation that these two constructed time-series are statistically equivalent. From the construction, it then follows that the distribution of time-series segments that are small compared to the overall delay in the system is independent of the value of the delay and of the coupling scheme. By focusing on numerical simulations of delay-coupled chaotic lasers, we present a practical example of our findings.

  7. Modeling of delays in PKPD: classical approaches and a tutorial for delay differential equations.

    Science.gov (United States)

    Koch, Gilbert; Krzyzanski, Wojciech; Pérez-Ruixo, Juan Jose; Schropp, Johannes

    2014-08-01

    In pharmacokinetics/pharmacodynamics (PKPD) the measured response is often delayed relative to drug administration, individuals in a population have a certain lifespan until they maturate or the change of biomarkers does not immediately affects the primary endpoint. The classical approach in PKPD is to apply transit compartment models (TCM) based on ordinary differential equations to handle such delays. However, an alternative approach to deal with delays are delay differential equations (DDE). DDEs feature additional flexibility and properties, realize more complex dynamics and can complementary be used together with TCMs. We introduce several delay based PKPD models and investigate mathematical properties of general DDE based models, which serve as subunits in order to build larger PKPD models. Finally, we review current PKPD software with respect to the implementation of DDEs for PKPD analysis.

  8. Fractional delay waveguide modeling of acoustic tubes

    Science.gov (United States)

    Vaelimaeki, V.

    The theme of this work is computational modeling of acoustic tubes. The models are intended to be used in a sound synthesizer based on physical modeling. Such a synthesizer could be used producing realistic sounds of, e.g., woodwind instruments or the human voice. This work deals with digital waveguide modeling of acoustic tubes, such as bores of musical woodwind instruments or the human vocal tract. The acoustic tube systems considered in this work are those consisting of a straight cylindrical or conical tube or of concatenated cylindrical or conical tube sections. Also, the joint of three tube sections is studied. Of special interest for our application is a junction where a side branch is connected to a cylindrical tube as it is needed in the simulation of finger holes of wood-wind instruments. All of the cylindrical tube models are described for both pressure and volume velocity. In the case of conical bores, only pressure waves are considered as models for volume velocity waves are more complicated. The basic waveguide models are extended by employing the concept of fractional delay, which means a delay smaller than a unit delay. The fractional delays are implemented using bandlimited interpolation. Applying fractional delay filtering techniques, a spatially discretized waveguide model is turned into a spatially continuous one. This implies that the length of the digital waveguide can be adjusted as accurately as required, and a change of the impedance of a waveguide may occur at any desired point between sampling points. The authors call this kind of system a fractional delay waveguide filter (FDWF). It is a discrete-time structure but a spatially continuous model of a physical system.

  9. Delayed recompression for decompression sickness: retrospective analysis.

    Directory of Open Access Journals (Sweden)

    Amir Hadanny

    Full Text Available Most cases of decompression sickness (DCS occur soon after surfacing, with 98% within 24 hours. Recompression using hyperbaric chamber should be administrated as soon as feasible in order to decrease bubble size and avoid further tissue injury. Unfortunately, there may be a significant time delay from surfacing to recompression. The time beyond which hyperbaric treatment is non effective is unclear. The aims of the study were first to evaluate the effect of delayed hyperbaric treatment, initiated more than 48 h after surfacing for DCS and second, to evaluate the different treatment protocols.From January 2000 to February 2014, 76 divers had delayed hyperbaric treatment (≥48 h for DCS in the Sagol center for Hyperbaric medicine and Research, Assaf-Harofeh Medical Center, Israel. Data were collected from their medical records and compared to data of 128 patients treated earlier than 48 h after surfacing at the same hyperbaric institute.There was no significant difference, as to any of the baseline characteristics, between the delayed and early treatment groups. With respect to treatment results, at the delayed treatment divers, complete recovery was achieved in 76% of the divers, partial recovery in 17.1% and no improvement in 6.6%. Similar results were achieved when treatment started early, where 78% of the divers had complete recovery, 15.6% partial recovery and 6.2% no recovery. Delayed hyperbaric treatment using US Navy Table 6 protocol trended toward a better clinical outcome yet not statistically significant (OR=2.786, CI95%[0.896-8.66], p=0.07 compared to standard hyperbaric oxygen therapy of 90 minutes at 2 ATA, irrespective of the symptoms severity at presentation.Late recompression for DCS, 48 hours or more after surfacing, has clinical value and when applied can achieve complete recovery in 76% of the divers. It seems that the preferred hyperbaric treatment protocol should be based on US Navy Table 6.

  10. Radiative thermal conduction fronts

    International Nuclear Information System (INIS)

    Borkowski, K.J.; Balbus, S.A.; Fristrom, C.C.

    1990-01-01

    The discovery of the O VI interstellar absorption lines in our Galaxy by the Copernicus observatory was a turning point in our understanding of the Interstellar Medium (ISM). It implied the presence of widespread hot (approx. 10 to the 6th power K) gas in disk galaxies. The detection of highly ionized species in quasi-stellar objects' absorption spectra may be the first indirect observation of this hot phase in external disk galaxies. Previous efforts to understand extensive O VI absorption line data from our Galaxy were not very successful in locating the regions where this absorption originates. The location at interfaces between evaporating ISM clouds and hot gas was favored, but recent studies of steady-state conduction fronts in spherical clouds by Ballet, Arnaud, and Rothenflug (1986) and Bohringer and Hartquist (1987) rejected evaporative fronts as the absorption sites. Researchers report here on time-dependent nonequilibrium calculations of planar conductive fronts whose properties match well with observations, and suggest reasons for the difference between the researchers' results and the above. They included magnetic fields in additional models, not reported here, and the conclusions are not affected by their presence

  11. Bilingualism as a strategy to delay the onset of Alzheimer's disease.

    Science.gov (United States)

    Klimova, Blanka; Valis, Martin; Kuca, Kamil

    2017-01-01

    The purpose of this study is to explore original studies which provide evidence about the effects of bilingualism on the delay of the onset of dementia, specifically Alzheimer's disease (AD). A literature review was conducted in the world's acknowledged databases: Web of Science, Scopus, and MEDLINE. Altogether, 14 original studies focusing on the research topic were detected. These included six prospective cohort studies and eight retrospective studies. Both types of studies suggest different conclusions. The findings from the prospective cohort studies state that there is no association between bilingualism and the delay of the onset of AD, while the retrospective studies claim the opposite. Despite the negative results of the prospective cohort studies, more research should be conducted on bilingualism and its impact on the delay of the onset of AD, since the brain studies have brought positive findings as far as the enhancement of cognitive reserve is concerned.

  12. Bilingualism as a strategy to delay the onset of Alzheimer’s disease

    Science.gov (United States)

    Klimova, Blanka; Valis, Martin; Kuca, Kamil

    2017-01-01

    The purpose of this study is to explore original studies which provide evidence about the effects of bilingualism on the delay of the onset of dementia, specifically Alzheimer’s disease (AD). A literature review was conducted in the world’s acknowledged databases: Web of Science, Scopus, and MEDLINE. Altogether, 14 original studies focusing on the research topic were detected. These included six prospective cohort studies and eight retrospective studies. Both types of studies suggest different conclusions. The findings from the prospective cohort studies state that there is no association between bilingualism and the delay of the onset of AD, while the retrospective studies claim the opposite. Despite the negative results of the prospective cohort studies, more research should be conducted on bilingualism and its impact on the delay of the onset of AD, since the brain studies have brought positive findings as far as the enhancement of cognitive reserve is concerned. PMID:29089747

  13. Delay line MWPC hazard signals inspector

    International Nuclear Information System (INIS)

    Turner, D.B.; Kirsten, F.; Guiragossian, Z.G.T.; Schilling, R.

    1976-01-01

    The Hazard Inspector is a CAMAC module which divides a MWPC delay line into 8 independent signal monitor and control segments. Independent control effectively reduces delay line occupation time and cuts the number of background and non-trigger particles accepted by the 4XQT charge-time-pulse-width digitizer, a device presented in a separate communication. Only segments containing legitimate information are digitized. Non-trigger related events are gated out at the digitizer, and contaminating hits are noted for computer correction

  14. Double Hopf bifurcation in delay differential equations

    Directory of Open Access Journals (Sweden)

    Redouane Qesmi

    2014-07-01

    Full Text Available The paper addresses the computation of elements of double Hopf bifurcation for retarded functional differential equations (FDEs with parameters. We present an efficient method for computing, simultaneously, the coefficients of center manifolds and normal forms, in terms of the original FDEs, associated with the double Hopf singularity up to an arbitrary order. Finally, we apply our results to a nonlinear model with periodic delay. This shows the applicability of the methodology in the study of delay models arising in either natural or technological problems.

  15. The delayed neutron method of uranium analysis

    International Nuclear Information System (INIS)

    Wall, T.

    1989-01-01

    The technique of delayed neutron analysis (DNA) is discussed. The DNA rig installed on the MOATA reactor, the assay standards and the types of samples which have been assayed are described. Of the total sample throughput of about 55,000 units since the uranium analysis service began, some 78% has been concerned with analysis of uranium ore samples derived from mining and exploration. Delayed neutron analysis provides a high sensitivity, low cost uranium analysis method for both uranium exploration and other applications. It is particularly suitable for analysis of large batch samples and for non-destructive analysis over a wide range of matrices. 8 refs., 4 figs., 3 tabs

  16. Time-delay analyzer with continuous discretization

    International Nuclear Information System (INIS)

    Bayatyan, G.L.; Darbinyan, K.T.; Mkrtchyan, K.K.; Stepanyan, S.S.

    1988-01-01

    A time-delay analyzer is described which when triggered by a start pulse of adjustable duration performs continuous discretization of the analyzed signal within nearly 22 ns time intervals, the recording in a memory unit with following slow read-out of the information to the computer and its processing. The time-delay analyzer consists of four CAMAC-VECTOR systems of unit width. With its help one can separate comparatively short, small-amplitude rare signals against the background of quasistationary noise processes. 4 refs.; 3 figs

  17. Management of delayed nuclear power plant projects

    International Nuclear Information System (INIS)

    1999-09-01

    According to the available information at the IAEA PRIS (Power Reactor Information System) at the end of 1998 there were more than 40 nuclear power plant projects with delays of five or more years with respect to the originally scheduled commercial operation. The degree of conformance with original construction schedules showed large variations due to several issues, including financial, economic and public opinion factors. Taking into account the number of projects with several years delay in their original schedules, it was considered useful to identify the subject areas where exchange of experience among Member States would be mutually beneficial in identification of problems and development of guidance for successful management of the completion of these delayed projects. A joint programme of the IAEA Departments of Nuclear Energy (Nuclear Power Engineering Section) and Technical Co-operation (Europe Section, with additional support from the Latin America and West Asia Sections) was set up during the period 1997-1998. The specific aim of the programme was to provide assistance in the management of delayed nuclear power plants regarding measures to maintain readiness for resuming the project implementation schedule when the conditions permit. The integration of IAEA interdepartmental resources enabled the participation of 53 experts from 14 Member States resulting in a wider exchange of experience and dissemination of guidance. Under the framework of the joint programme, senior managers directly responsible for delayed nuclear power plant projects identified several issues or problem areas that needed to be addressed and guidance on management be provided. A work plan for the development of several working documents, addressing the different issues, was established. Subsequently these documents were merged into a single one to produce the present publication. This publication provides information and practical examples on necessary management actions to preserve

  18. Causal Analysis of Railway Running Delays

    DEFF Research Database (Denmark)

    Cerreto, Fabrizio; Nielsen, Otto Anker; Harrod, Steven

    against service transit times and railway asset productivity. Methods to investigate the quality of supplement time allocation are necessary to reduce the behavioral response and the waste of resources. This is a preliminary study that investigates train delay data from the year 2014 supplied by Rail Net...... Denmark (the Danish infrastructure manager). The statistical analysis of the data identifies the minimum running times and the scheduled running time supplements and investigates the evolution of train delays along given train paths. An improved allocation of time supplements would result in smaller...

  19. 4-channel time delayed pulse generator

    International Nuclear Information System (INIS)

    Wetzel, L.F.S.; Rossi, J.O.; Del Bosco, E.

    1987-02-01

    It is described the project of a 4-channel delayed pulse generator employed to trigger the plasma centrifuge experiment of the Laboratorio Associado de Plasmas. The circuit delivers pulses with amplitude of 15V, full width at half maximum of 50μs and rise time of 0.7μs. The maximum time delay is 100ms. There are two channels with a fine adjustment of 0-1ms. The system can be manually or automatically driven. (author) [pt

  20. 48 CFR 42.1304 - Government delay of work.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Government delay of work... CONTRACT MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Suspension of Work, Stop-Work Orders, and Government Delay of Work 42.1304 Government delay of work. (a) The clause at 52.242-17, Government Delay of...