299 research outputs found

    Shape Optimization for Time-dependent Domains

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    In this thesis, we treat shape optimization for parabolic equations on time-dependent domains. As a theoretical foundation we extend the solution theory of parabolic boundary integral equations in the canonical Sobolev spaces from the cylindrical to the time-dependent case. The results imply existence and uniqueness of solutions. This is followed by a review of shape optimization theory on time-dependent domains, where we complement a few proofs which seem to be missing in the literature. Building on these foundations we give general formulae for shape gradients of functionals. These theoretical results are complemented by two numerical examples. The first example is concerned with a time-dependent shape detection problem, reformulated as a time-dependent shape optimization problem. The second example is a time-dependent one-phase Stefan problem in multiple dimensions, also reformulated as a shape optimization problem

    Systematic Low-Energy Effective Field Theory for Electron-Doped Antiferromagnets

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    In contrast to hole-doped systems which have hole pockets centered at (±π2a,±π2a)(\pm \frac{\pi}{2a},\pm \frac{\pi}{2a}), in lightly electron-doped antiferromagnets the charged quasiparticles reside in momentum space pockets centered at (πa,0)(\frac{\pi}{a},0) or (0,πa)(0,\frac{\pi}{a}). This has important consequences for the corresponding low-energy effective field theory of magnons and electrons which is constructed in this paper. In particular, in contrast to the hole-doped case, the magnon-mediated forces between two electrons depend on the total momentum P\vec P of the pair. For P=0\vec P = 0 the one-magnon exchange potential between two electrons at distance rr is proportional to 1/r41/r^4, while in the hole case it has a 1/r21/r^2 dependence. The effective theory predicts that spiral phases are absent in electron-doped antiferromagnets.Comment: 25 pages, 7 figure

    Social Wasps in Exotic Forest Planting and Atlantic Rainforest in the Neotropical Region

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    Social wasps play an important role in communities, whether in natural or agricultural ecosystems, performing pollination and/or predation on other organisms, especially caterpillars, which reveals their potential for biological control. We register species of predatory wasps found in a eucalypt reforested area compared with a native rainforest. Five species of social wasps were found: Agelaia myrmecophila (Ducke), Mischocyttarus punctatus (Ducke), Polistes carnifex (Fabricius), Polybia liliacea (Fabricius), and Polybia striata (Fabricius), with higher numbers in the eucalypt monoculture than in the Atlantic rainforest, suggesting no negative impact of the monoculture on the population of that natural enemies

    Surveillance for European bat lyssavirus in Swiss bats

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    Most countries in Western Europe are currently free of rabies in terrestrial mammals. Nevertheless, rabies remains a residual risk to public health due to the natural circulation of bat-specific viruses, such as European bat lyssaviruses (EBLVs). European bat lyssavirus types 1 and 2 (EBLV-1 and EBLV-2) are widely distributed throughout Europe, but little is known of their true prevalence and epidemiology. We report that only three out of 837 brains taken from bats submitted to the Swiss Rabies Centre between 1976 and 2009 were found by immunofluorescence (FAT) to be positive for EBLVs. All three positive cases were in Myotis daubentoni, from 1992, 1993 and 2002. In addition to this passive surveillance, we undertook a targeted survey in 2009, aimed at detecting lyssaviruses in live bats in Switzerland. A total of 237 bats of the species M. daubentoni, Myotis myotis, Eptesicus serotinus and Nyctalus noctula were captured at different sites in western Switzerland. Oropharyngeal swabs and blood from each individual were analysed by RT-PCR and rapid fluorescent focus inhibition test (RFFIT), respectively. RNA corresponding to EBLV-2 was detected from oropharyngeal swabs of a single M. daubentoni bat, but no infectious virus was found. Molecular phylogenetic analysis revealed that the corresponding sequence was closely related to the other EBLV-2 sequences identified in previous rabies isolates from Swiss bats (particularly to that found at Geneva in 2002). Three M. daubentoni bats were found to be seropositive by RFFIT. In conclusion, even though the prevalence is low in Switzerland, continuous management and surveillance are required to assess the potential risk to public healt

    Discrete Improvement in Racial Disparity in Survival among Patients with Stage IV Colorectal Cancer: a 21-Year Population-Based Analysis

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    Purpose Recently, multiple clinical trials have demonstrated improved outcomes in patients with metastatic colorectal cancer. This study investigated if the improved survival is race dependent. Patients and Methods Overall and cancer-specific survival of 77,490 White and Black patients with metastatic colorectal cancer from the 1988–2008 Surveillance Epidemiology and End Results registry were compared using unadjusted and multivariable adjusted Cox proportional hazard regression as well as competing risk analyses. Results Median age was 69 years, 47.4 % were female and 86.0 % White. Median survival was 11 months overall, with an overall increase from 8 to 14 months between 1988 and 2008. Overall survival increased from 8 to 14 months for White, and from 6 to 13 months for Black patients. After multivariable adjustment, the following parameters were associated with better survival: White, female, younger, better educated and married patients, patients with higher income and living in urban areas, patients with rectosigmoid junction and rectal cancer, undergoing cancer-directed surgery, having well/moderately differentiated, and N0 tumors (p<0.05 for all covariates). Discrepancies in overall survival based on race did not change significantly over time; however, there was a significant decrease of cancer-specific survival discrepancies over time between White and Black patients with a hazard ratio of 0.995 (95 % confidence interval 0.991–1.000) per year (p=0.03). Conclusion A clinically relevant overall survival increase was found from 1988 to 2008 in this population-based analysis for both White and Black patients with metastatic colorectal cancer. Although both White and Black patients benefitted from this improvement, a slight discrepancy between the two groups remained

    A convergent interaction engine: vocal communication among marmoset monkeys

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    To understand the primate origins of the human interaction engine, it is worthwhile to focus not only on great apes but also on callitrichid monkeys (marmosets and tamarins). Like humans, but unlike great apes, callitrichids are cooperative breeders, and thus habitually engage in coordinated joint actions, for instance when an infant is handed over from one group member to another. We first explore the hypothesis that these habitual cooperative interactions, the marmoset interactional ethology, are supported by the same key elements as found in the human interaction engine: mutual gaze (during joint action), turn-taking, volubility, as well as group-wide prosociality and trust. Marmosets show clear evidence of these features. We next examine the prediction that, if such an interaction engine can indeed give rise to more flexible communication, callitrichids may also possess elaborate communicative skills. A review of marmoset vocal communication confirms unusual abilities in these small primates: high volubility and large vocal repertoires, vocal learning and babbling in immatures, and voluntary usage and control. We end by discussing how the adoption of cooperative breeding during human evolution may have catalysed language evolution by adding these convergent consequences to the great ape-like cognitive system of our hominin ancestors. This article is part of the theme issue ‘Revisiting the human ‘interaction engine’: comparative approaches to social action coordination’

    Разработка плана ХАССП на продукцию из дикоросов

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    В процессе исследования проводилось изучение документации компании, тщательное изучение технологического процесса, оценка безопасности производства продукции, определение ккт, разработка плана ХАССП. В результате исследования разработан план ХАССП на продукцию из дикоросов а именно на продукцию масло кедровое и жмых кедровый. Разработаны мероприятия для ккт.In the process of the study, the company's documentation was studied, a thorough study of the technological process, an assessment of the safety of production, the definition of the project, the development of the HACCP plan. As a result of the research, a plan of HACCP was developed for the production of wild plants, namely, the products of cedar and cedar oil. Developed activities for the book

    Metabolic memory underlying minimal residual disease in breast cancer.

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    Funder: European Molecular Biology LaboratoryFunder: European Molecular Biology Laboratory (EMBL)Tumor relapse from treatment-resistant cells (minimal residual disease, MRD) underlies most breast cancer-related deaths. Yet, the molecular characteristics defining their malignancy have largely remained elusive. Here, we integrated multi-omics data from a tractable organoid system with a metabolic modeling approach to uncover the metabolic and regulatory idiosyncrasies of the MRD. We find that the resistant cells, despite their non-proliferative phenotype and the absence of oncogenic signaling, feature increased glycolysis and activity of certain urea cycle enzyme reminiscent of the tumor. This metabolic distinctiveness was also evident in a mouse model and in transcriptomic data from patients following neo-adjuvant therapy. We further identified a marked similarity in DNA methylation profiles between tumor and residual cells. Taken together, our data reveal a metabolic and epigenetic memory of the treatment-resistant cells. We further demonstrate that the memorized elevated glycolysis in MRD is crucial for their survival and can be targeted using a small-molecule inhibitor without impacting normal cells. The metabolic aberrances of MRD thus offer new therapeutic opportunities for post-treatment care to prevent breast tumor recurrence

    Cosmic-ray strangelets in the Earth's atmosphere

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    If strange quark matter is stable in small lumps, we expect to find such lumps, called ``strangelets'', on Earth due to a steady flux in cosmic rays. Following recent astrophysical models, we predict the strangelet flux at the top of the atmosphere, and trace the strangelets' behavior in atmospheric chemistry and circulation. We show that several strangelet species may have large abundances in the atmosphere; that they should respond favorably to laboratory-scale preconcentration techniques; and that they present promising targets for mass spectroscopy experiments.Comment: 28 pages, 4 figures, revtex
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