Particle creation in a colliding plane wave spacetime: Wave packet quantization

We use wave packet mode quantization to compute the creation of massless scalar quantum particles in a colliding plane wave spacetime. The background spacetime represents the collision of two gravitational shock waves followed by trailing gravitational radiation which focus into a Killing-Cauchy horizon. The use of wave packet modes simplifies the problem of mode propagation through the different spacetime regions which was previously studied with the use of monochromatic modes. It is found that the number of particles created in a given wave packet mode has a thermal spectrum with a temperature which is inversely proportional to the focusing time of the plane waves and which depends on the mode trajectory.

ZHARP: three-dimensional motion tracking from a single image plane.

Three-dimensional imaging and quantification of myocardial function are essential steps in the evaluation of cardiac disease. We propose a tagged magnetic resonance imaging methodology called zHARP that encodes and automatically tracks myocardial displacement in three dimensions. Unlike other motion encoding techniques, zHARP encodes both in-plane and through-plane motion in a single image plane without affecting the acquisition speed. Postprocessing unravels this encoding in order to directly track the 3-D displacement of every point within the image plane throughout an entire image sequence. Experimental results include a phantom validation experiment, which compares zHARP to phase contrast imaging, and an in vivo study of a normal human volunteer. Results demonstrate that the simultaneous extraction of in-plane and through-plane displacements from tagged images is feasible.

D. Aurelii Augustini Hipponensis episcopi Meditationum libellus plane pijissimus. Hunc alii Anselmo Cantuariensi archiepiscopo ascribunt ([Reprod.])

Collection : French books before 1601 ; 488.6

The role of focal therapy in the management of localised prostate cancer: a systematic review.

CONTEXT: The incidence of localised prostate cancer is increasing worldwide. In light of recent evidence, current, radical, whole-gland treatments for organ-confined disease have being questioned with respect to their side effects, cancer control, and cost. Focal therapy may be an effective alternative strategy. OBJECTIVE: To systematically review the existing literature on baseline characteristics of the target population; preoperative evaluation to localise disease; and perioperative, functional, and disease control outcomes following focal therapy. EVIDENCE ACQUISITION: Medline (through PubMed), Embase, Web of Science, and Cochrane Review databases were searched from inception to 31 October 2012. In addition, registered but not yet published trials were retrieved. Studies evaluating tissue-preserving therapies in men with biopsy-proven prostate cancer in the primary or salvage setting were included. EVIDENCE SYNTHESIS: A total of 2350 cases were treated to date across 30 studies. Most studies were retrospective with variable standards of reporting, although there was an increasing number of prospective registered trials. Focal therapy was mainly delivered to men with low and intermediate disease, although some high-risk cases were treated that had known, unilateral, significant cancer. In most of the cases, biopsy findings were correlated to specific preoperative imaging, such as multiparametric magnetic resonance imaging or Doppler ultrasound to determine eligibility. Follow-up varied between 0 and 11.1 yr. In treatment-naïve prostates, pad-free continence ranged from 95% to 100%, erectile function ranged from 54% to 100%, and absence of clinically significant cancer ranged from 83% to 100%. In focal salvage cases for radiotherapy failure, the same outcomes were achieved in 87.2-100%, 29-40%, and 92% of cases, respectively. Biochemical disease-free survival was reported using a number of definitions that were not validated in the focal-therapy setting. CONCLUSIONS: Our systematic review highlights that, when focal therapy is delivered with intention to treat, the perioperative, functional, and disease control outcomes are encouraging within a short- to medium-term follow-up. Focal therapy is a strategy by which the overtreatment burden of the current prostate cancer pathway could be reduced, but robust comparative effectiveness studies are now required.

Stimulus-induced, sleep-bound, focal seizures: a case report.

STUDY OBJECTIVES: In nocturnal frontal lobe epilepsy (NFLE), seizures occur almost exclusively during NREM sleep. Why precisely these seizures are sleep-bound remains unknown. Studies of patients with nonlesional familial forms of NFLE have suggested the arousal system may play a major role in their pathogenesis. We report the case of a patient with pharmaco-resistant, probably cryptogenic form of non-familial NFLE and strictly sleep-bound seizures that could be elicited by alerting stimuli and were associated with ictal bilateral thalamic and right orbital-insular hyperperfusion on SPECT imaging. DESIGN: Case report. SETTING: University Hospital Zurich. PATIENTS OR PARTICIPANTS: One patient with pharmaco-resistant epilepsy. CONCLUSION: This case shows that the arousal system plays a fundamental role also in cryptogenic non-familial forms of NFLE.

Perforation colique néonatale focale spontanée en dehors de la grande prématurité : rare et potentiellement insidieuse [Focal spontaneous colic perforation in term or near-term neonates: rare and potentially insidious].

Two cases of neonatal focal spontaneous colic perforations are reported. The 1st infant, born at 36 3/7 weeks gestational age, presented on day 3 with crying, abdominal distension, and liquid stools. Clinical examination showed a slightly irritable hypothermic (35.7 °C) infant with a distended abdomen and few bowel sounds. Blood tests were normal apart from an elevated C-reactive protein level (59 mg/l). The abdomen x-ray was erroneously considered normal. The infant's condition remained stable for nearly 3 days. After reviewing the initial x-ray, pneumoperitoneum was suspected and confirmed by a cross-table lateral abdominal x-ray. The infant was started on antibiotics and operated. Macroscopically, the entire gut was normal apart from a focal sigmoid perforation, which was stitched. A transmural colic biopsy revealed focal vascular dilation but was negative for necrotising enterocolitis or Hirschsprung disease. The infant recovered quickly. She is now a healthy, normal 3-year-old. The 2nd infant, born at 38 5/7 weeks gestational age, presented between day 1 and 2 with clinical signs of infection associated with slowly progressive ileus. The chest and abdomen x-ray was mistakenly considered normal. Frank septicemia developed. After reviewing the initial x-ray, pneumoperitoneum was suspected and confirmed by a cross-table lateral abdominal x-ray. The infant was operated. Macroscopically, the small intestine was normal, the ascending and transverse colons were dilated, and the descending and sigmoid colons were narrow. Three cecal perforations were discovered and stitched. An ileostomy and multiple colic biopsies were also performed. The postoperative course was complicated by persistent septic ileus due to descending and sigmoid colon leaks, which led to colic resections with end-to-end anastomosis. Rectal aspiration biopsies were also performed. At 1 month of age, the infant was discharged from the hospital. The ileostomy was closed in two steps at 2 and 5 months of age. A normal sweat test excluded cystic fibrosis. All colic and rectal biopsies revealed nonspecific inflammatory signs and excluded necrotizing enterocolitis and Hirschsprung disease. Nonspecific irregular thinning of muscularis mucosae and muscularis propria were observed in the two resected colic segments. The boy is now a healthy 7-year-old. The incidence of neonatal focal spontaneous colic perforations at term or close to term is unknown but probably very rare. Our department is the neonatal referral center for approximately 14,000 annual births. In the last 10 years (2000-2009), out of 5115 neonatal admissions in our unit, only ten cases have presented a neonatal spontaneous intestinal perforation, seven of ten in very-low-birth-weight infants and three of ten in term or near-term neonates (one with Hirschsprung disease and the two cases reported herein). In the same period, 108 infants suffered from necrotizing enterocolitis, seven of 108 were term infants and 6 out of 7 had a congenital heart disease. The medical literature is poor on the subject of focal spontaneous colic perforations at term; no risk factor is described. The most specific clinical sign seems to be the abdominal distension. The presence of pneumoperitoneum on an abdominal x-ray is the most sensitive paraclinical sign. In case of an intestinal perforation, surgery must be performed quickly. The vital prognosis seems to be good. The objective of this study was to draw pediatricians' attention to focal spontaneous colic perforations in term or close to term newborns. In the cases reported, the diagnostic delays could have been prevented if the entity - with its radiological manifestation - had been well known.

Health technology assessment in evolution - focal therapy in localised prostate cancer.

Focal therapy in prostate cancer aims to treat only the part of the gland harboring clinically significant disease while preserving the rest of the tissue. This approach may substantially reduce treatment-related toxicity without compromising disease control outcomes. Short- to medium-term functional and oncological results in prospective interventional studies are promising, but comparative effectiveness research against standard of care is required to incorporate focal therapy among standard options. In this review, we discuss the actual stage of assessment and results of sources of energy commonly used to deliver focal therapy. We also provide our viewpoint on how the field will evolve in the near future.

Rupture d'une hyperplasie nodulaire focale. A propos de deux cas [Rupture of hepatic focal nodular hyperplasia. About two cases]

The diagnostics of focal nodular hyperplasia is reached through the use of imaging. When the diagnostic is certain, surgical abstention is the rule. Nevertheless, we were confronted with two cases of a rare complication; that of intraperitoneal rupture. In this situation, we suggest to first do an arteriography to control the bleeding, then to perform surgery when the patient has reached hemodynamic stability. Spontaneous rupture as a complication of benign nodular hyperplasia remains a rare event and only five cases were reported in litterature.

Influence of pre partum and post partum plane of nutrition on the performance of crossbred suckler cows and their progeny

Selostus: Sisäruokintakauden energiamäärien vaikutus risteytysemolehmien tuotantoon

Transcranial direct current stimulation for the treatment of focal hand dystonia.

The treatment of writer's cramp, a task-specific focal hand dystonia, needs new approaches. A deficiency of inhibition in the motor cortex might cause writer's cramp. Transcranial direct current stimulation modulates cortical excitability and may provide a therapeutic alternative. In this randomized, double-blind, sham-controlled study, we investigated the efficacy of cathodal stimulation of the contralateral motor cortex in 3 sessions in 1 week. Assessment over a 2-week period included clinical scales, subjective ratings, kinematic handwriting analysis, and neurophysiological evaluation. Twelve patients with unilateral dystonic writer's cramp were investigated; 6 received transcranial direct current and 6 sham stimulation. Cathodal transcranial direct current stimulation had no favorable effects on clinical scales and failed to restore normal handwriting kinematics and cortical inhibition. Subjective worsening remained unexplained, leading to premature study termination. Repeated sessions of cathodal transcranial direct current stimulation of the motor cortex yielded no favorable results supporting a therapeutic potential in writer's cramp.

Détection des lésions focales hépatiques malignes. Comparaison de l'échographie, de la porto-tomodensitométrie, de la tomodensitométrie tardive et de l'imagerie par résonance magnétique [Detection of malignant focal hepatic lesions. Comparison of ultrasonography, computerized tomography during arterial portography, delayed computerized tomography and magnetic resonance imaging]

AIMS: This study was performed to compare the sensitivity of ultrasonography, computerized tomography during arterial portography, delayed computerized tomography, and magnetic resonance imaging to detect focal liver lesions. Forty three patients with primary or secondary malignant liver lesions were studied prior to surgical intervention. METHODS: The results of the imaging studies were compared with intraoperative examination of the liver, intraoperative ultrasonography and pathology results (29 patients). In the non-operated (14 patients) group, we compared the number of lesions detected by each technique. RESULTS: One hundred and forty six lesions were detected. There was 84% sensitivity with computerized tomography during arterial portography, 61.3% with delayed scan, 63.3% with magnetic resonance imaging and 51% with ultrasonography in operated patients. In patients who did not undergo surgery, magnetic resonance imaging was more sensitive in detecting lesions. CONCLUSIONS: In operated and non-operated patients series, CT during arterial portography had the highest sensitivity, but magnetic resonance imaging had the most consistent overall results.

Evolution of the neurochemical profile after transient focal cerebral ischemia in the mouse brain.

Evolution of the neurochemical profile consisting of 19 metabolites after 30 mins of middle cerebral artery occlusion was longitudinally assessed at 3, 8 and 24 h in 6 to 8 microL volumes in the striatum using localized 1H-magnetic resonance spectroscopy at 14.1 T. Profound changes were detected as early as 3 h after ischemia, which include elevated lactate levels in the presence of significant glucose concentrations, decreases in glutamate and a transient twofold glutamine increase, likely to be linked to the excitotoxic release of glutamate and conversion into glial glutamine. Interestingly, decreases in N-acetyl-aspartate (NAA), as well as in taurine, exceeded those in neuronal glutamate, suggesting that the putative neuronal marker NAA is rather a sensitive marker of neuronal viability. With further ischemia evolution, additional, more profound concentration decreases were detected, reflecting a disruption of cellular functions. We conclude that early changes in markers of energy metabolism, glutamate excitotoxicity and neuronal viability can be detected with high precision non-invasively in mice after stroke. Such investigations should lead to a better understanding and insight into the sequential early changes in the brain parenchyma after ischemia, which could be used for identifying new targets for neuroprotection.

Periodic orbits of integrable birational maps on the plane: blending dynamics and algebraic geometry, the Lyness' case

Contingut del Pòster presentat al congrés New Trends in Dynamical Systems