The Nuclear Window to the Extragalactic Universe

We investigate two recent parameterizations of the galactic magnetic field with respect to their impact on cosmic nuclei traversing the field. We present a comprehensive study of the size of angular deflections, dispersion in the arrival probability distributions, multiplicity in the images of arrival on Earth, variance in field transparency, and influence of the turbulent field components. To remain restricted to ballistic deflections, a cosmic nucleus with energy E and charge Z should have a rigidity above E/Z=6 EV. In view of the differences resulting from the two field parameterizations as a measure of current knowledge in the galactic field, this rigidity threshold may have to be increased. For a point source search with E/Z>60 EV, field uncertainties increase the required signal events for discovery moderately for sources in the northern and southern regions, but substantially for sources near the galactic disk.Comment: 15 pages, 30 figures, few additional sentences and references as in accepted publicatio

Electrolytic Reduction of Indigo in Pyridine Application to the Determination of Dissolved Oxygen

The electrochemical reduction of indigo in pyridine as solvent has been investigated in connection with the determination of oxygen dissolved in pyridine, using polarography, cyclic voltammetry, controlled electrode potential electrolysis and coulometry. In the absence of protons, the total current of the first and second reduction waves for an unsaturated solution of indigo (LiClO 4 as background electrolyte) apparently represents a one‐electron transfer. In the presence of an excess of available protons (added as pyridinium nitrate), indigo is reduced in a reversible two‐electron process to indigo white (leucoindigo). The rapid conversion of indigo white to indigo by oxygen in pyridine solution can be used to determine coulometrically the concentration of oxygen in pyridine via measurement of the indigo produced on adding the pyridine‐oxygen sample to a solution of in situ electrolytically generated indigo white. The latter approach indicated a general method for the determination of dissolved oxygen in nonaqueous solvents.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101790/1/197000109_ftp.pd

Automation in Surgery : The Impact of Navigated-Control Assistance on Performance, Workload, Situation Awareness, and Acquisition of Surgical Skills

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Objective: Human performance consequences of a new technology of image-guided navigation (IGN) support for surgeons are investigated. Background: Navigated control (NC) represents an advancement of IGN technology. In contrast to currently available pointer-based systems, it represents a higher degree of automation that supports processes not only of information analysis and integration but also of intraoperative decision making. Method: In the first experiment, 14 surgical novices performed a simulated mastoidectomy with and without NC support. Effects of provision of the system were analyzed with respect to different measures of surgical performance and outcome, workload, and situation awareness. In the second experiment, 21 advanced medical students were trained to perform a mastoidectomy by practicing it either with or without NC support. It was investigated to what extent the provision of the system during practice would affect the acquisition of surgical skills. Results: The results reveal that NC support can reduce both the risk of intraoperative injuries and complications as well as the physiological effort of surgeons. “Cost effects” compared to a conventional (i.e., not supported) surgery emerged with respect to the time needed for the surgery, increased subjective workload, reduced spare capacity, and a reduced level of situation awareness. However, no significant effects on processes of skill acquisition were found. Conclusion: NC systems can contribute to improved patient safety. Most of the cost effects seem to be related not to the basic principle of NC but to its current technological implementation. Application: The results have consequences for the design and clinical use of automated navigation support

Automation in Surgery: The Impact of Navigated-Control Assistance on the Performance, Workload and Situation Awareness of Surgeons

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The present study investigates performance consequences of a new approach of automated support for surgeons. “Navigated-Control” (NC) represents an advancement of image-guided navigation that does not only support the surgeon in navigating through a patient's anatomy, but also can stop the surgical device if it comes too close to risk structures which need to be protected to ensure patient safety. It is explored, how NC affects different aspects of surgical outcome, workload and stress, and situation awareness. Fourteen advanced students of medicine performed a simulated Mastoidectomy with and without NC support. The results reveal that NC support can reduce both, the risk of intra-operative injuries, as well as the physiological stress level of surgeons. However, “cost effects” emerged with respect to subjective workload, and a reduced spare capacity compared to unsupported surgeries. These latter effects do not seem to be related to the principle of NC but technical constraints of current implementations

CRPropa 3.0 - a Public Framework for Propagating UHE Cosmic Rays through Galactic and Extragalactic Space

The interpretation of experimental data of ultra-high energy cosmic rays (UHECRs) above 10^17 eV is still under controversial debate. The development and improvement of numerical tools to propagate UHECRs in galactic and extragalactic space is a crucial ingredient to interpret data and to draw conclusions on astrophysical parameters. In this contribution the next major release of the publicly available code CRPropa (3.0) is presented. It reflects a complete redesign of the code structure to facilitate high performance computing and comprises new physical features such as an interface for galactic propagation using lensing techniques and inclusion of cosmological effects in a three-dimensional environment. The performance is benchmarked and first applications are presented.Comment: 4 pages, 3 figures. Proceedings of the 33rd International Cosmic Ray Conference (ICRC), Rio de Janeiro, Brazil, 2-9 July 201

Salivary gland mucoepidermoid carcinoma is a clinically, morphologically and genetically heterogeneous entity: a clinicopathological study of 40 cases with emphasis on grading, histological variants and presence of the t(11;19) translocation

International audienceAims: To correlate World Health Organization (WHO) grade, patient's outcome and presence of t(11;19) to histological tumor variants in 40 well characterized mucoepidermoid carcinomas (MECs) out of a series of 290 salivary gland carcinomas. Methods and Results: MECs were classified as classical based on the presence of equal proportions of the three cell types or the dominance (≥50%) of mucous cells beside at least one other cell type, and as variant if composed of ≥80% single cell type. Classical MECs were more common (n=23). Variant MECs had predominant squamoid (n=9), eosinophilic (n=5), or clear cell (n=3) morphology. 27 tumors were WHO grade 1, 3 grade 2 and 10 grade 3. The t(11;19) was detected in 82%, 35% and 0% of classical MEC, variant MEC and non-MEC, respectively. Classical MECs were significantly associated with age ≤60 years (p<0.001), grade 1 (p<0.001), and t(11;19) (p=0.003). Short overall survival was significantly associated with age >60 years (p=0.001) and UICC stage >I (p=0.031), residual tumor (p<0.001), tumor grade >1 (p=0.001) and squamoid variant (p=0.002) in Kaplan-Meier analysis. Conclusions: The results underscore the great histological diversity of MEC, the reproducibility of the WHO grading and the value of histological subtypes as an additional prognostic factor

Cyclooxygenase 2: understanding the pathophysiological role through genetically altered mouse models

El pdf del artículo es la versión post-print.Cyclooxygenase (COX) -1 and –2 catalyze the first step in the biosynthesis of prostanoids. COX-1 is constitutively expressed in many tissues and seems to be involved in the house keeping function of prostanoids. COX-2, the inducible isoform, accounts for the elevated production of prostaglandins in response to various inflammatory stimuli, hormones and growth factors. COX-2 expression has been also associated with cell growth regulation, tissue remodelling and carcinogenesis. More of these characteristics have been elucidate through using COX selective inhibitors. Recent advances in transgenic and gene-targeting approaches allow a sophisticated manipulation of the mouse genome by gene addition, gene deletion or gene modifications. The development of COX-2 genetically altered mice has provided models to elucidate the physiological and pathophysiological roles of this enzyme.This work was supported by grants from Instituto de Salud Carlos III (Red de Centros C03/01), Generalitat Valenciana (GRUPOS03/072), Ministerio de Educación y Ciencia (SAF2004-00957) and Comunidad de Madrid (CAM2004-GR/SAL/0388).Peer reviewe