Chirurgische Therapiestrategien beim Ösophagus- und Magenkarzinom

Zusammenfassung: Diese Übersichtsarbeit hat zum Ziel, die aktuellen chirurgischen Strategien bei der Behandlung des Ösophagus- und Magenkarzinoms zusammenzufassen. Neben den etablierten Standardverfahren wird auf die limitierten Resektionen bei Frühkarzinomen und den Stellenwert der Chirurgie im multimodalen Behandlungskonzept bei lokal fortgeschrittenen T3/4-Tumoren eingegangen. Das Plattenepithelkarzinom und das Adenokarzinom (Barrett-Karzinom) der Speiseröhre werden aufgrund der unterschiedlichen Pathogenese und Tumorbiologie sowie differenzierter unterschiedlicher Vorgehensweisen separat dargestellt. Aufgrund der überwiegend distalen Lokalisation der Barrett-Karzinome ist eine Abgrenzung zu den echten Kardiakarzinomen und Tumoren, die im Magen ihren Ursprung nehmen und die distale Speiseröhre infiltrieren, erforderlich. Basierend auf der Klassifikation nach Siewert wird das Barrett-Karzinom deshalb zusammen mit den so genannten Adenokarzinomen des ösophagogastralen Übergangs (AEG) behandelt. Für die Weiterentwicklung der chirurgischen Therapiestrategien beim Magenkarzinom haben sich die asiatischen, insbesondere japanischen und südkoreanischen Kollegen große Verdienste erworben. Moderne, dort entwickelte, aber noch nicht in der westlichen Welt etablierte Strategien werden neben den Standardverfahren gebührend berücksichtigt. Für alle diese Tumoren gilt, dass die chirurgische Therapie ein elementarer Bestandteil im Rahmen eines kurativen Behandlungskonzepts ist. Sie ist aber differenzierter und Teil eines komplexen interdisziplinären Algorithmus; deshalb ist eine weitere Spezialisierung zum Wohle der Patienten ratsa

Probable Innocence Revisited

International audienceOften we wish to ensure that the identity of the user performing a certain action is maintained secret. This property is called anonymity. Examples of situations in which we may wish to provide anonymity include: publishing on the web, retrieving information from the web, sending a message, etc. Many protocols have been designed for this purpose, for example, Crowds [15], Onion Routing [23], the Free Haven [7], Web MIX [1] and Freenet [4]

Detection methods for non-Gaussian gravitational wave stochastic backgrounds

We address the issue of finding an optimal detection method for a discontinuous or intermittent gravitational wave stochastic background. Such a signal might sound something like popcorn popping. We derive an appropriate version of the maximum likelihood detection statistic, and compare its performance to that of the standard cross-correlation statistic both analytically and with Monte Carlo simulations. The maximum likelihood statistic performs better than the cross-correlation statistic when the background is sufficiently non-Gaussian. For both ground and space based detectors, this results in a gain factor, ranging roughly from 1 to 3, in the minimum gravitational-wave energy density necessary for detection, depending on the duty cycle of the background. Our analysis is exploratory, as we assume that the time structure of the events cannot be resolved, and we assume white, Gaussian noise in two collocated, aligned detectors. Before this detection method can be used in practice with real detector data, further work is required to generalize our analysis to accommodate separated, misaligned detectors with realistic, colored, non-Gaussian noise.Comment: 25 pages, 12 figures, submitted to physical review D, added revisions in response to reviewers comment

Thermodynamic gauge-theory cascade

It is proposed that the cooling of a thermalized SU($N$) gauge theory can be formulated in terms of a cascade involving three effective theories with successively reduced (and spontaneously broken) gauge symmetries, SU($N$) $\to$ U(1)$^{N-1}$ $\to$ Z$_N$. The approach is based on the assumption that away from a phase transition the bulk of the quantum interaction inherent to the system is implicitly encoded in the (incomplete) classical dynamics of a collective part made of low-energy condensed degrees of freedom. The properties of (some of the) statistically fluctuating fields are determined by these condensate(s). This leads to a quasi-particle description at tree-level. It appears that radiative corrections, which are sizable at large gauge coupling, do not change the tree-level picture qualitatively. The thermodynamic self-consistency of the quasi-particle approach implies nonperturbative evolution equations for the associated masses. The temperature dependence of these masses, in turn, determine the evolution of the gauge coupling(s). The hot gauge system approaches the behavior of an ideal gas of massless gluons at asymptotically large temperature. A negative equation of state is possible at a stage where the system is about to settle into the phase of the (spontaneously broken) Z$_N$ symmetry.Comment: 25 pages, 6 figures, 1 reference added, minor corrections in text, errors in Sec. 3.2 corrected, PRD versio

Early Sports Specialization: An International Perspective

The physical activity required for most sports has numerous health benefitsVphysical, mental, and academic (5,22,35). Some young athletes specialize in a single sport, while others play multiple sports throughout adolescence. Primary reasons to specialize early include enjoying that single sport; lifestyle access to a particular sport, such as running (34); hope for financial or other special success; or parental pressure. Regions with few resources expect organized sports may provide a safer environment for physical activity than the outdoor neighborhood (e.g., South Africa and Brazil) or increase government-supplied resources to youth sports organizations based on the number of children enrolled (Australia (1)). Recent concerns by sports medicine experts have sparked debate about the wisdom of early sports specialization (3Y6,21,36), but virtually no solid data have been published to inform caregivers, coaches, and families about possible risks and benefits. Sports specialization below the age of 18 yr has been suggested to increase injury risk, decrease social opportunity, and impair life satisfaction (4,16). Additional review articles (23,24) and consensus statements by major sports medicine organizations (3Y5,8,21,36) suggest that early specialization is a culprit potentially leading to adults with history of excessive injuries and limited social opportunity, even suggesting dire consequences (24). However, research supporting these statements is minimal or absent

Probabilistic Anonymity

The concept of anonymity comes into play in a wide range of situations, varying from voting and anonymous donations to postings on bulletin boards and sending mails. A formal definition of this concept has been given in literature in terms of nondeterminism. In this paper, we investigate a notion of anonymity based on probability theory, and we we discuss the relation with the nondeterministic one. We then formulate this definition in terms of observables for processes in the probabilistic $pi$-calculus, and propose a method to verify automatically the anonymity property. We illustrate the method by using the example of the dining cryptographers

Ability of the 4-D-Var analysis of the GOSAT BESD XCO₂ retrievals to characterize atmospheric CO₂ at large and synoptic scales

This study presents results from the European Centre for Medium-Range Weather Forecasts (ECMWF) carbon dioxide (CO₂) analysis system where the atmospheric CO₂ is controlled through the assimilation of column-averaged dry-air mole fractions of CO₂ (XCO₂) from the Greenhouse gases Observing Satellite (GOSAT). The analysis is compared to a free-run simulation (without assimilation of XCO₂), and they are both evaluated against XCO₂ data from the Total Carbon Column Observing Network (TCCON). We show that the assimilation of the GOSAT XCO₂ product from the Bremen Optimal Estimation Differential Optical Absorption Spectroscopy (BESD) algorithm during the year 2013 provides XCO₂ fields with an improved mean absolute error of 0.6 parts per million (ppm) and an improved station-to-station bias deviation of 0.7  ppm compared to the free run (1.1 and 1.4  ppm, respectively) and an improved estimated precision of 1  ppm compared to the GOSAT BESD data (3.3  ppm). We also show that the analysis has skill for synoptic situations in the vicinity of frontal systems, where the GOSAT retrievals are sparse due to cloud contamination. We finally computed the 10-day forecast from each analysis at 00:00  UTC, and we demonstrate that the CO₂ forecast shows synoptic skill for the largest-scale weather patterns (of the order of 1000  km) even up to day 5 compared to its own analysis

Solving atomic multicast when groups crash

In this paper, we study the atomic multicast problem, a fundamental abstraction for building faulttolerant systems. In the atomic multicast problem, the system is divided into non-empty and disjoint groups of processes. Multicast messages may be addressed to any subset of groups, each message possibly being multicast to a different subset. Several papers previously studied this problem either in local area networks [3, 9, 20] or wide area networks [13, 21]. However, none of them considered atomic multicast when groups may crash. We present two atomic multicast algorithms that tolerate the crash of groups. The first algorithm tolerates an arbitrary number of failures, is genuine (i.e., to deliver a message m, only addressees of m are involved in the protocol), and uses the perfect failures detector P. We show that among realistic failure detectors, i.e., those that do not predict the future, P is necessary to solve genuine atomic multicast if we do not bound the number of processes that may fail. Thus, P is the weakest realistic failure detector for solving genuine atomic multicast when an arbitrary number of processes may crash. Our second algorithm is non-genuine and less resilient to process failures than the first algorithm but has several advantages: (i) it requires perfect failure detection within groups only, and not across the system, (ii) as we show in the paper it can be modified to rely on unreliable failure detection at the cost of a weaker liveness guarantee, and (iii) it is fast, messages addressed to multiple groups may be delivered within two inter-group message delays only

A comparative study of epitaxial InGaAsBi/InP structures using Rutherford backscattering spectrometry, X-ray diffraction and photoluminescence techniques

In this work, we used a combination of photoluminescence (PL), high resolution X-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) techniques to investigate material quality and structural properties of MBE-grown InGaAsBi samples (with and without an InGaAs cap layer) with targeted bismuth composition in the 3%–4% range. XRD data showed that the InGaAsBi layers are more homogeneous in the uncapped samples. For the capped samples, the growth of the InGaAs capped layer at higher temperature affects the quality of the InGaAsBi layer and bismuth distribution in the growth direction. Low-temperature PL exhibited multiple emission peaks; the peak energies, widths, and relative intensities were used for comparative analysis of the data in line with the XRD and RBS results. RBS data at a random orientation together with channeled measurements allowed both an estimation of the bismuth composition and analysis of the structural properties. The RBS channeling showed evidence of higher strain due to possible antisite defects in the capped samples grown at a higher temperature. It is also suggested that the growth of the capped layer at high temperature causes deterioration of the bismuth-layer quality. The RBS analysis demonstrated evidence of a reduction of homogeneity of uncapped InGaAsBi layers with increasing bismuth concentration. The uncapped higher bismuth concentration sample showed less defined channeling dips suggesting poorer crystal quality and clustering of bismuth on the sample surface