86 research outputs found

    A Smart Pixel Camera for future Cherenkov Telescopes

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    The Smart Pixel Camera is a new camera for imaging atmospheric Cherenkov telescopes, suited for a next generation of large multi-telescope ground based gamma-ray observatories. The design of the camera foresees all electronics needed to process the images to be located inside the camera body at the focal plane. The camera has a modular design and is scalable in the number of pixels. The camera electronics provides the performance needed for the next generation instruments, like short signal integration time, topological trigger and short trigger gate, and at the same time the design is optimized to minimize the cost per channel. In addition new features are implemented, like the measurement of the arrival time of light pulses in the pixels on the few hundred psec timescale. The buffered readout system of the camera allows to take images at sustained rates of O(10 kHz) with a dead-time of only about 0.8 % per kHz.Comment: 8 pages, 5 figures; to appear in the proceedings of "Towards a Network of Atmospheric Cherenkov Detectors VII", 2005, Palaiseau, Franc

    RARE-01: Cerebral infarction in childhood-onset craniopharyngioma patients: results of KRANIOPHARYNGEOM 2007 [Abstract]

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    BACKGROUND: Cerebral infarction (CI) is a known vascular complication following treatment of suprasellar tumors. Risk factors for CI, incidence rate, and long-term prognosis are unknown for patients with childhood-onset craniopharyngioma (CP). METHODS: MRI of 244 CP patients, recruited between 2007 and 2019 in KRANIOPHA-RYNGEOM 2007, were reviewed for CI. Risk factors for CI and outcome after CI were analyzed. RESULTS: Twenty-eight of 244 patients (11%) presented with CI based on reference assessment of MRI. One CI occurred before initial surgery and one case of CI occurred after release of intracystic pressure by a cyst catheter. 26 of 28 CI were detected after surgical tumor resection at a median postoperative interval of one day (range: 0.5 - 53 days). Vascular lesions during surgical procedures were documented in 7 cases with CI. No relevant differences with regard to surgical approaches were found. In all 12 irradiated patients, CI occurred before irradiation. Multivariable analyses showed that hydrocephalus and gross-total resection at the time of primary diagnosis / surgery both were risk factors for CI. After CI, quality of life (PEDQOL) and functional capacity (FMH) were impaired. CONCLUSIONS: CI occurs in 11% of surgically-treated CP cases. Degree of resection and increased intracranial pressure are risk factors, which should be considered in the planning of surgical procedures for prevention of CI

    Nuchal skinfold thickness in pediatric brain tumor patients

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    BACKGROUND: Severe obesity and tumor relapse/progression have impact on long-term prognosis in pediatric brain tumor patients. METHODS: In a cross-sectional study, we analyzed nuchal skinfold thickness (NST) on magnetic-resonance imaging (MRI) follow-up monitoring as a parameter for assessment of nuchal adipose tissue in 177 brain tumor patients (40 World Health Organization (WHO) grade 1–2 brain tumor; 31 grade 3–4 brain tumor; 106 craniopharyngioma), and 53 healthy controls. Furthermore, body mass index (BMI), waist-to-height ratio, caliper-measured skinfold thickness, and blood pressure were analyzed for association with NST. RESULTS: Craniopharyngioma patients showed higher NST, BMI, waist-to-height ratio, and caliper-measured skinfold thickness when compared to other brain tumors and healthy controls. WHO grade 1–2 brain tumor patients were observed with higher BMI, waist circumference and triceps caliper-measured skinfold thickness when compared to WHO grade 3–4 brain tumor patients. NST correlated with BMI, waist-to-height ratio, and caliper-measured skinfold thickness. NST, BMI and waist-to-height ratio were associated with increased blood pressure. In craniopharyngioma patients with hypothalamic involvement/lesion or gross-total resection, rate and degree of obesity were increased. CONCLUSIONS: NST could serve as a novel useful marker for regional nuchal adipose tissue. NST is highly associated with body mass and waist-to-height ratio, and easily measurable in routine MRI monitoring of brain tumor patients

    Cerebral infarction in childhood-onset craniopharyngioma patients: results of KRANIOPHARYNGEOM 2007

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    BACKGROUND: Cerebral infarction (CI) is a known vascular complication following treatment of suprasellar tumors. Risk factors for CI, incidence rate, and long-term prognosis are unknown for patients with childhood-onset craniopharyngioma (CP). METHODS: MRI of 244 CP patients, recruited between 2007 and 2019 in KRANIOPHARYNGEOM 2007, were reviewed for CI. Risk factors for CI and outcome after CI were analyzed. RESULTS: Twenty-eight of 244 patients (11%) presented with CI based on reference assessment of MRI. One CI occurred before initial surgery and one case of CI occurred after release of intracystic pressure by a cyst catheter. 26 of 28 CI were detected after surgical tumor resection at a median postoperative interval of one day (range: 0.5-53 days). Vascular lesions during surgical procedures were documented in 7 cases with CI. No relevant differences with regard to surgical approaches were found. In all 12 irradiated patients, CI occurred before irradiation. Multivariable analyses showed that hydrocephalus and gross-total resection at the time of primary diagnosis/surgery both were risk factors for CI. After CI, quality of life (PEDQOL) and functional capacity (FMH) were impaired. CONCLUSIONS: CI occurs in 11% of surgically-treated CP cases. Degree of resection and increased intracranial pressure are risk factors, which should be considered in the planning of surgical procedures for prevention of CI

    Experimental analysis of the TRC benchmark system

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    The Tribomechadynamics Research Challenge (TRC) was a blind prediction of the vibration behavior of a thin plate clamped on two sides using bolted joints. The first bending mode's natural frequency and damping ratio were requested as function of the amplitude, starting from the linear regime until high levels, where both frictional contact and nonlinear bending-stretching coupling become relevant. The predictions were confronted with experimental results in a companion paper; the present article addresses the experimental analysis of this benchmark system. Amplitude-dependent modal data was obtained from phase resonance and response controlled tests. An original variant of response controlled testing is proposed: Instead of a fixed frequency interval, a fixed phase interval is analyzed. This way, the high excitation levels required outside resonance, which could activate unwanted exciter nonlinearity, are avoided. Consistency of testing methods is carefully analyzed. Overall, these measures have permitted to gain high confidence in the acquired modal data. The different sources of the remaining uncertainty were further analyzed. A low reassembly-variability but a moderate time-variability were identified, where the latter is attributed to some thermal sensitivity of the system. Two nominally identical plates were analyzed, which both have an appreciable initial curvature, and a significant effect on the vibration behavior was found depending on whether the plate is aligned/misaligned with the support structure. Further, a 1:2 nonlinear modal interaction with the first torsion mode was observed, which only occurs in the aligned configurations

    POSTER: Towards Secure 5G Infrastructures for Production Systems

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    To meet the requirements of modern production, industrial communication increasingly shifts from wired fieldbus to wireless 5G communication. Besides tremendous benefits, this shift introduces severe novel risks, ranging from limited reliability over new security vulnerabilities to a lack of accountability. To address these risks, we present approaches to (i) prevent attacks through authentication and redundant communication, (ii) detect anomalies and jamming, and (iii) respond to detected attacks through device exclusion and accountability measures.Comment: Accepted to the poster session of the 22nd International Conference on Applied Cryptography and Network Security (ACNS 2024

    Perinatally diagnosed congenital craniopharyngiomas in the Kraniopharyngeom trials

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    Background Craniopharyngiomas (CPs) are rare embryonic tumors. Clinical presentation and outcome of patients perinatally diagnosed with congenital CP (cCP) are not clear and refer mainly to a few case reports in the literature. The aim of this study was to analyze clinical presentation and outcome in patients with cCP. Study design Three hundred and sixty-one patients diagnosed with adamantinomatous CP were recruited 2007–2022 in KRANIOPHARYNGEOM 2007/Registry 2019 and prospectively observed. In two cases, cCP was diagnosed prenatally and in one case on the second day of life. Pre- and perinatal diagnostic findings, postnatal evaluation, and therapeutic interventions and outcome in these three cases of cCP were analyzed. Results All patients survived. One patient developed psychomotor retardation and a mild hemiparesis. Prenatal routine ultrasound examination led to the diagnosis of cCP. Tumor resection was performed during the early postnatal period (range: 11–51 days of age). Functional capacity, measured by Fertigkeitenskala-Münster-Heidelberg (FMH) was reduced in three and behavioral parameters, measured by the Strength and Difficulties Questionnaire (SDQ) were abnormal in two cases. Conclusion cCP is a rare diagnosis with a prevalence of 0.83% in our study group. Compared to cases reported in the literature, the presented cases were treated immediately and had a better prognosis. Based on improvements of diagnostic and therapeutic techniques, prenatal diagnosis of cCP should lead to transfer prior to delivery of cCP patients to a specialized center for delivery and postnatal treatment of newborns with sellar masses by a multidisciplinary team to secure the improved prognosis of these patients. Significance statement We previously reported that lower event-free survival rates after craniopharyngioma are associated with younger age at diagnosis. Perinatally diagnosed congenital craniopharyngiomas are very rare. This article presents three unique cases with congenital craniopharyngioma, comparing their diagnostics, therapy, and development. All three cases had surgery during the early postnatal period with sparing of the posterior hypothalamus. In each case, endocrinopathy was present at follow-up. Low functional capacity was reported in all cases and an abnormal total difficulties score in two cases. Compared to the literature, the presented cases had better prognosis in morbidity and mortality. This report and the review of the literature confirm the importance of a multidisciplinary approach in the diagnostic and treatment of the very rare condition of congenital craniopharyngioma

    Posterior hypothalamus-sparing surgery improves outcome after childhood craniopharyngioma

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    Objective: Quality of life (QoL) is frequently impaired in childhood-onset craniopharyngioma (CP) by hypothalamic syndrome. The debate, whether pretreatment hypothalamic involvement (HI) has apriori prognostic impact or surgical hypothalamic lesions (HL) determine outcome, is controversial. Design: Survival and outcome of CPs recruited between 2007 and 2014 in KRANIOPHARYNGEOM 2007 were analyzed with regard to reference-confirmed presurgical HI and surgical HL. Methods: Radiological findings, BMI and QoL were assessed at diagnosis and during follow-up. QoL was assessed using Pediatric Quality of Life (PEDQOL) questionnaire. Results: One hundred sixty-nine CPs were included presenting with no HI (n = 11), anterior (n = 49) and anterior + posterior (a + p) HI (n = 109) prior to surgery. The latter 109 were analyzed for postoperative HL (no lesion: n = 23, anterior HL: n = 29, a + pHL: n = 57). Progression-free survival (PFS) was higher after complete resection. The highest PFS was observed in CP with a + pHL, especially when compared between non-irradiated subgroups (P = 0.006). Overall survival (OS) rates were 1.0 in all subgroups. CP with a + pHL developed higher BMI (P ≤ 0.001) during follow-up compared between subgroups. 55/109 pts with a + pHI completed PEDQOL at diagnosis (48/109 at 3 years follow-up). QoL was worse for a + pHL patients in terms of physical, social and emotional functionality when compared with the anterior HL and no HL subgroup. BMI development and QoL during follow-up were similar for patients with anterior HL and without HL. Conclusions: Posterior hypothalamus-sparing surgical strategies are associated with higher QoL, decreased development of obesity and lower PFS in CP
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