176 research outputs found

    Fertilitätsprotektion bei Krebspatientinnen: Die psychologische Dimension

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    Zusammenfassung: Krebsbehandlungen führen nicht selten zu einer Beeinträchtigung der Fruchtbarkeit. Für die weitere Lebensperspektive vieler junger Krebspatientinnen wäre es deshalb von großer Bedeutung, wenn im entscheidenden Moment Maßnahmen zur Erhaltung ihrer Fruchtbarkeit getroffen würden. Die Entscheidung für oder gegen eine fruchtbarkeitserhaltende Maßnahme bedeutet jedoch eine zusätzliche Belastung für alle Beteiligten. Das enge Zeitfenster zwischen Diagnosestellung und Beginn der Krebsbehandlung bedingt, dass die Entscheidung unter beträchtlichem Zeitdruck gefällt werden muss und oft mit einem Chaos der Gefühle - von existenzieller Todesangst bis hin zu Hoffnung und Euphorie - verbunden ist. Wird den Patientinnen diese Möglichkeit aber nicht angeboten, kann die psychische Belastung, die durch den Verlust der Furchtbarkeit entstehen kann, möglicherweise ein Leben lang bestehen. Basierend auf den zur Verfügung stehenden Studienresultaten werden psychologische Aspekte im Zusammenhang mit der Fertilitätsprotektion bei jungen Krebspatientinnen dargelegt. Insbesondere wird auf den Stellenwert der Fruchtbarkeit, die Haltung gegenüber fruchtbarkeitserhaltenden Maßnahmen, auf Konflikte bei der Entscheidungsfindung und auf Unterstützungsmöglichkeiten eingegange

    Convergence properties of η3π\eta\to 3\pi decays in chiral perturbation theory

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    Theoretical efforts to describe and explain the η3π\eta\to 3\pi decays reach far back in time. Even today, the convergence of the decay widths and some of the Dalitz plot parameters seems problematic in low energy QCD. In the framework of resummed CHPT, we explore the question of compatibility of experimental data with a reasonable convergence of a carefully defined chiral series, where NNLO remainders are assumed to be small. By treating the uncertainties in the higher orders statistically, we numerically generate a large set of theoretical predictions, which are then confronted with experimental information. In the case of the decay widths, the experimental values can be reconstructed for a reasonable range of the free parameters and thus no tension is observed, in spite of what some of the traditional calculations suggest. The Dalitz plot parameters aa and dd can be described very well too. When the parameters bb and α\alpha are concerned, we find a mild tension for the whole range of the free parameters, at less than 2σ\sigma C.L. This can be interpreted in two ways - either some of the higher order corrections are indeed unexpectedly large or there is a specific configuration of the remainders, which is, however, not completely improbable. Also, the distribution of the theoretical uncertainties is found to be significantly non-gaussian, so the consistency cannot be simply judged by the 1σ\sigma error bars.Comment: 57 pages, 5 figure

    Isospin Breaking and ω\omega->ππ\pi\pi Decay

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    We study ωπ+π\omega\to\pi^+\pi^- decay up to including all orders of the chiral expansion and one-loop level of mesons in formlism of chiral constituent quark model. This G-parity forbidden decay is caused by mumdm_u\neq m_d and electromagnetic interaction of mesons. We illustrate that in the formlism both nonresonant contact interaction and ρ\rho resonance exchange contribute to this process, and the contribution from ρ\rho resonance exchange is dominant. We obtain that transition matrix element is =[(3956±280)(1697±130)i]=[-(3956\pm 280)-(1697\pm 130)i]MeV2^2, and isospin breaking parameter is mdmu=3.9±0.22m_d-m_u=3.9\pm 0.22MeV at energy scale μmω\mu\sim m_\omega.Comment: Revtex file, 16 pages, four eps figur

    Gauge-invariant Green's functions for the bosonic sector of the standard model

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    There are many applications in gauge theories where the usually employed framework involving gauge-dependent Green's functions leads to considerable problems. In order to overcome the difficulties invariably tied to gauge dependence, we present a manifestly gauge-invariant approach. We propose a generating functional of appropriately chosen gauge-invariant Green's functions for the bosonic sector of the standard model. Since the corresponding external sources emit one-particle states, these functions yield the same S-matrix elements as those obtained in the usual framework. We evaluate the generating functional for the bosonic sector of the standard model up to the one-loop level and carry out its renormalization in the on-shell scheme. Explicit results for some two-point functions are given. Gauge invariance is manifest at any step of our calculation.Comment: 29 pages, Revtex. v2: Discussions improved, conclusions unchanged. Some references added. v3: Published versio

    The Electromagnetic Mass Differences of Pions and Kaons

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    We use the Cottingham method to calculate the pion and kaon electromagnetic mass differences with as few model dependent inputs as possible. The constraints of chiral symmetry at low energy, QCD at high energy and experimental data in between are used in the dispersion relation. We find excellent agreement with experiment for the pion mass difference. The kaon mass difference exhibits a strong violation of the lowest order prediction of Dashen's theorem, in qualitative agreement with several other recent calculations.Comment: 40 pages, Latex, needs axodraw. and psfig. macros, 4 figure

    Shape modeling technique KOALA validated by ESA Rosetta at (21) Lutetia

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    We present a comparison of our results from ground-based observations of asteroid (21) Lutetia with imaging data acquired during the flyby of the asteroid by the ESA Rosetta mission. This flyby provided a unique opportunity to evaluate and calibrate our method of determination of size, 3-D shape, and spin of an asteroid from ground-based observations. We present our 3-D shape-modeling technique KOALA which is based on multi-dataset inversion. We compare the results we obtained with KOALA, prior to the flyby, on asteroid (21) Lutetia with the high-spatial resolution images of the asteroid taken with the OSIRIS camera on-board the ESA Rosetta spacecraft, during its encounter with Lutetia. The spin axis determined with KOALA was found to be accurate to within two degrees, while the KOALA diameter determinations were within 2% of the Rosetta-derived values. The 3-D shape of the KOALA model is also confirmed by the spectacular visual agreement between both 3-D shape models (KOALA pre- and OSIRIS post-flyby). We found a typical deviation of only 2 km at local scales between the profiles from KOALA predictions and OSIRIS images, resulting in a volume uncertainty provided by KOALA better than 10%. Radiometric techniques for the interpretation of thermal infrared data also benefit greatly from the KOALA shape model: the absolute size and geometric albedo can be derived with high accuracy, and thermal properties, for example the thermal inertia, can be determined unambiguously. We consider this to be a validation of the KOALA method. Because space exploration will remain limited to only a few objects, KOALA stands as a powerful technique to study a much larger set of small bodies using Earth-based observations.Comment: 15 pages, 8 figures, 2 tables, accepted for publication in P&S

    The electroweak chiral Lagrangian reanalyzed

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    In this paper we reanalyze the electroweak chiral Lagrangian with particular focus on two issues related to gauge invariance. Our analysis is based on a manifestly gauge-invariant approach that we introduced recently. It deals with gauge-invariant Green's functions and provides a method to evaluate the corresponding generating functional without fixing the gauge. First we show, for the case where no fermions are included in the effective Lagrangian, that the set of low-energy constants currently used in the literature is redundant. In particular, by employing the equations of motion for the gauge fields one can choose to remove two low-energy constants which contribute to the self-energies of the gauge bosons. If fermions are included in the effective field theory analysis the situation is more involved. Even in this case, however, these contributions to the self-energies of the gauge bosons can be removed. The relation of this result to the experimentally determined values for the oblique parameters S, T, and U is discussed. In the second part of the paper we consider the matching relation between a full and an effective theory. We show how the low-energy constants of the effective Lagrangian can be determined by matching gauge-invariant Green's functions in both theories. As an application we explicitly evaluate the low-energy constants for the standard model with a heavy Higgs boson. The matching at the one-loop level and at next-to-leading order in the low-energy expansion is performed employing functional methods.Comment: 44 pages, Revtex. v2: Sections II and III interchanged. New section II now self-contained. Discussions improved in sections I, II, V.C and VI. Conclusions unchanged. Published versio

    Cancer Predisposition Cascade Screening for Hereditary Breast/Ovarian Cancer and Lynch Syndromes in Switzerland: Study Protocol

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    Background : Breast, colorectal, ovarian, and endometrial cancers constitute approximately 30% of newly diagnosed cancer cases in Switzerland, affecting more than 12,000 individuals annually. Hundreds of these patients are likely to carry germline pathogenic variants associated with hereditary breast ovarian cancer (HBOC) or Lynch syndrome (LS). Genetic services (counseling and testing) for hereditary susceptibility to cancer can prevent many cancer diagnoses and deaths through early identification and risk management. Objective : Cascade screening is the systematic identification and testing of relatives of a known mutation carrier. It determines whether asymptomatic relatives also carry the known variant, needing management options to reduce future harmful outcomes. Specific aims of the CASCADE study are to (1) survey index cases with HBOC or LS from clinic-based genetic testing records and determine their current cancer status and surveillance practices, needs for coordination of medical care, psychosocial needs, patient-provider and patient-family communication, quality of life, and willingness to serve as advocates for cancer genetic services to blood relatives, (2) survey first- and second-degree relatives and first-cousins identified from pedigrees or family history records of HBOC and LS index cases and determine their current cancer and mutation status, cancer surveillance practices, needs for coordination of medical care, barriers and facilitators to using cancer genetic services, psychosocial needs, patient-provider and patient-family communication, quality of life, and willingness to participate in a study designed to increase use of cancer genetic services, and (3) explore the influence of patient-provider communication about genetic cancer risk on patient-family communication and the acceptability of a family-based communication, coping, and decision support intervention with focus group(s) of mutation carriers and relatives. Methods: CASCADE is a longitudinal study using surveys (online or paper/pencil) and focus groups, designed to elicit factors that enhance cascade genetic testing for HBOC and LS in Switzerland. Repeated observations are the optimal way for assessing these outcomes. Focus groups will examine barriers in patient-provider and patient-family communication, and the acceptability of a family-based communication, coping, and decision-support intervention. The survey will be developed in English, translated into three languages (German, French, and Italian), and back-translated into English, except for scales with validated versions in these languages. Results: Descriptive analyses will include calculating means, standard deviations, frequencies, and percentages of variables and participant descriptors. Bivariate analyses (Pearson correlations, chi-square test for differences in proportions, and t test for differences in means) will assess associations between demographics and clinical characteristics. Regression analyses will incorporate generalized estimating equations for pairing index cases with their relatives and explore whether predictors are in direct, mediating, or moderating relationship to an outcome. Focus group data will be transcribed verbatim and analyzed for common themes. Conclusions: Robust evidence from basic science and descriptive population-based studies in Switzerland support the necessity of cascade screening for genetic predisposition to HBOC and LS. CASCADE is designed to address translation of this knowledge into public health interventions. Trial Registration: ClinicalTrials.gov NCT03124212; https://clinicaltrials.gov/ct2/show/NCT03124212 (Archived by WebCite at http://www.webcitation.org/6tKZnNDBt
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