5,627 research outputs found

    Regularizing effect and local existence for non-cutoff Boltzmann equation

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    The Boltzmann equation without Grad's angular cutoff assumption is believed to have regularizing effect on the solution because of the non-integrable angular singularity of the cross-section. However, even though so far this has been justified satisfactorily for the spatially homogeneous Boltzmann equation, it is still basically unsolved for the spatially inhomogeneous Boltzmann equation. In this paper, by sharpening the coercivity and upper bound estimates for the collision operator, establishing the hypo-ellipticity of the Boltzmann operator based on a generalized version of the uncertainty principle, and analyzing the commutators between the collision operator and some weighted pseudo differential operators, we prove the regularizing effect in all (time, space and velocity) variables on solutions when some mild regularity is imposed on these solutions. For completeness, we also show that when the initial data has this mild regularity and Maxwellian type decay in velocity variable, there exists a unique local solution with the same regularity, so that this solution enjoys the CC^\infty regularity for positive time

    Me estuve quieto: el concepto de estado y el llamado Se aspectual

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    Magnetic ordering and fluctuation in kagome lattice antiferromagnets, Fe and Cr jarosites

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    Jarosite family compounds, KFe_3(OH)_6(SO_4)_2, (abbreviate Fe jarosite), and KCr_3(OH)_6(SO_4)_2, (Cr jarosite), are typical examples of the Heisenberg antiferromagnet on the kagome lattice and have been investigated by means of magnetization and NMR experiments. The susceptibility of Cr jarosite deviates from Curie-Weiss law due to the short-range spin correlation below about 150 K and shows the magnetic transition at 4.2 K, while Fe jarosite has the transition at 65 K. The susceptibility data fit well with the calculated one on the high temperature expansion for the Heisenberg antiferromagnet on the kagome lattice. The values of exchange interaction of Cr jarosite and Fe jarosite are derived to be J_Cr = 4.9 K and J_Fe = 23 K, respectively. The 1H-NMR spectra of Fe jarosite suggest that the ordered spin structure is the q = 0 type with positive chirality of the 120 degrees configuration. The transition is caused by a weak single-ion type anisotropy. The spin-lattice relaxation rate, 1/T_1, of Fe jarosite in the ordered phase decreases sharply with lowering the temperature and can be well explained by the two-magnon process of spin wave with the anisotropy.Comment: REVTeX, 14 pages with 5 figures. Submitted to Canadian Journal of Physic

    The Rise of Gay Culture and Why Portland is Different

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    This paper serves as a short history of the gay movement in Portland, as well as the reasons why Portland’s movement was inherently dissimilar to the movements of other major cities. It begins by providing historical context on the movements of some of Americas biggest cities, focusing primarily on the 1969 events of the Stonewall Riots in New York, the election and assassination of Harvey Milk in San Francisco, and Seattle’s movement for the purpose of comparison. A brief history on homosexuality in Portland’s recent past follows, going on then to the influence of “Darcelle’s” for the growing gay movement in the late 1970s and 1980s. The election of Portland’s first gay mayor, Sam Adams, in 2008 concludes the paper

    The Rise of Gay Culture and Why Portland is Different

    Get PDF
    This paper serves as a short history of the gay movement in Portland, as well as the reasons why Portland’s movement was inherently dissimilar to the movements of other major cities. It begins by providing historical context on the movements of some of Americas biggest cities, focusing primarily on the 1969 events of the Stonewall Riots in New York, the election and assassination of Harvey Milk in San Francisco, and Seattle’s movement for the purpose of comparison. A brief history on homosexuality in Portland’s recent past follows, going on then to the influence of “Darcelle’s” for the growing gay movement in the late 1970s and 1980s. The election of Portland’s first gay mayor, Sam Adams, in 2008 concludes the paper

    Epigenomes in Cardiovascular Disease.

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    If unifying principles could be revealed for how the same genome encodes different eukaryotic cells and for how genetic variability and environmental input are integrated to impact cardiovascular health, grand challenges in basic cell biology and translational medicine may succumb to experimental dissection. A rich body of work in model systems has implicated chromatin-modifying enzymes, DNA methylation, noncoding RNAs, and other transcriptome-shaping factors in adult health and in the development, progression, and mitigation of cardiovascular disease. Meanwhile, deployment of epigenomic tools, powered by next-generation sequencing technologies in cardiovascular models and human populations, has enabled description of epigenomic landscapes underpinning cellular function in the cardiovascular system. This essay aims to unpack the conceptual framework in which epigenomes are studied and to stimulate discussion on how principles of chromatin function may inform investigations of cardiovascular disease and the development of new therapies

    Bending and springback prediction method based on multi-scale finite element analyses for high bendability and low springback sheet generation

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    In this study, a sheet bendability and springback property evaluation technology through bending test simulations is newly developed using our multi-scale finite element analysis code, which is based on the crystallographic homogenization method

    Mobilizing agro-biodiversity and social networks to cope with adverse effects of climate and social changes: experiences from Kitui, Kenya

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    Poster presented at 13th Congress of the International Society of Ethnobiology. Montpellier (France), 20-25 May 201

    Diet diversification through local foods: experiences from traditional vegetable promotion work in Kenya

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