82,182 research outputs found
One dimensional lattice gases with rapidly decreasing interactions
No full textWe consider the pressure and the correlation functions of a one dimensional lattice gas in which the mutual interaction decreases as r exp-n t, (r, t>0), when the interparticle distance nrarrinfin. We prove that such a system cannot show phase transitions of order kgE1 in the sense that the pressure and the correlation functions are infinitely differentiable with respect to any relevant parameter (such as the temperature or the chemical potential)
Spiranthes nivea var. nivea T. P. Lin & W. M. Lin 2011
No full textSpiranthes nivea T.P. Lin & W.M. Lin (2011: 320) var. nivea — Fig. 4. Type:— TAIWAN. Pingtung: Tahanshan, 20 May 2009, Y.F. Wang s.n. (holotype: TAI 270634!). Synonym:— Spiranthes suishaensis auct. non (Hayata 1916: 86) Schlechter (1919: 161): Lin (2016: 117). Morphological descriptions and illustrations: —See Lin & Lin (2011: 320; f. 5), Surveswaran et al. (2017: 125; f. 4), Hsu & Chung (2016: 188), as Spiranthes suishaensis, and Lin (2019: 266; f. 117; pl. 13). Distribution and ecology: —The typical variety species is only recorded from the type locality, Tahanshan (Mt. Tahan) in southern Taiwan. It grows on semi-open roadside slopes around 1400–1600 m elev. and flowers from March to April. Additional specimens examined: — TAIWAN. Pingtung Co.: Mt. Tahan, 13 March 2013, T.-C. Hsu 6342 (TAIF!); Tahanshan, 9 April 2013, S.-S. Lin s.n. (TAI!). Taxonomic remarks: — Spiranthes nivea is most similar to S. hongkongensis, but it differs in having nearly glabrous labellum disc, smaller glabrous basal labellum callosities, and sparsely pubescent glabrous rachis, ovaries, and sepals.Published as part of Suetsugu, Kenji & Hsu, Tian-Chuan, 2023, Taxonomic revision of the genus Spiranthes (Orchidaceae) in Taiwan, pp. 1-10 in Phytotaxa 578 (1) on page 5, DOI: 10.11646/phytotaxa.578.1.1, http://zenodo.org/record/751762
Vascular endothelial growth factor restores delayed tumor progression in tumors depleted of macrophages
No full textGenetic depletion of macrophages in Polyoma Middle T oncoprotein (PyMT)-induced mammary tumors in mice delayed the angiogenic switch and the progression to malignancy. To determine whether vascular endothelial growth factor A (VEGF-A) produced by tumor-associated macrophages regulated the onset of the angiogenic switch, a genetic approach was used to restore expression of VEGF-A into tumors at the benign stages. This stimulated formation of a high-density vessel network and in macrophage-depleted mice, was followed by accelerated tumor progression. The expression of VEGF-A led to a massive infiltration into the tumor of leukocytes that were mostly macrophages. This study suggests that macrophage-produced VEGF regulates malignant progression through stimulating tumor angiogenesis, leukocytic infiltration and tumor cell invasion
G4-flux and standard model vacua in F-theory
No full textAbstractWe study the geometry of gauge fluxes in four-dimensional F-theory vacua with gauge group SU(3)×SU(2)×U(1)×U(1) and its implications for phenomenology. The models are defined by a previously introduced class of elliptic fibrations whose fibre is given as a cubic hypersurface in Bl2P2, with the non-abelian gauge group factors SU(3)×SU(2) engineered torically via the top construction. To describe gauge fluxes on these fibrations we provide a classification of the primary vertical middle cohomology group in a fashion valid for any choice of base space. Using the ideal theoretic technique of primary decomposition we compute the cohomology classes of the matter surfaces associated with states charged under the non-abelian gauge group. These expressions allow us to interpret the cancellation of the pure and mixed non-abelian anomalies geometrically as a result of the general form of the matter surfaces, without reference to a specific type of gauge flux. Explicit results for the chiral indices of all matter states are obtained in terms of intersection numbers of the base and can be directly applied to any choice of base consistent with the fibration. As a demonstration we scan for globally consistent F-theory vacua on P3, Bl1P3 and Bl2P3, and find a globally consistent flux configuration with the chiral Standard Model spectrum plus an extra triplet pair, which may be lifted by a recombination process
SPATIAL CHOW-LIN METHODS: BAYESIAN AND ML FORECAST COMPARISONS
No full textCompleting data that are collected in disaggregated and heterogeneous spatial units is a quite frequent problem in spatial analyses of regional data. Chow and Lin (1971) (CL) were the rst to develop a uni ed framework for the three problems (interpolation, extrapolation and distribution) of predicting disaggregated times series by so-called indicator series. This paper develops a spatial CL procedure for disaggregating cross-sectional spatial data and compares the Maximum Likelihood and Bayesian spatial CL forecasts with the naive pro rata error distribution. We outline the error covariance structure in a spatial context, derive the BLUE for the ML estimator and the Bayesian estimation procedure by MCMC. Finally we
apply the procedure to European regional GDP data and discuss the disaggregation assumptions. For the evaluation of the spatial Chow-Lin procedure we assume that only NUTS 1 GDP is known and predict it at NUTS 2 by using employment and spatial information available at NUTS 2. The spatial neighborhood is de ned by the inverse travel time by car in minutes. Finally, we present the forecast accuracy criteria comparing the predicted values with the actual observations.
Letter from Carl Hayden to Henry F. Ashurst
No full textLetter describing three enclosures, a letter from F. M. Gold, Carl T. Hayden's reply to Gold's letter, and a copy of a bill introduced by Cameron
Letter from A. F. Potter to Carl Hayden
No full textLetter from A. F. Potter to Carl T. Hayden describing John H. Page's request to build a railway for the Canyon Copper Company as "impractical"
Poincare duality algebras and rings of coinvariants
No full textLet rho : G hooked right arrow GL(n, F) be a faithful representation of a finite group G over the field F. Via rho the group G acts on V = F-n and hence on the algebra F[V] of homogenous polynomial functions on the vector space V. R. Kane (1994) formulated the following result based on the work of R. Steinberg (1964): If the field F has characteristic 0, then F[V](G) is a Poincare duality algebra if and only if G is a pseudoreflection group. The purpose of this note is to extend this result to the case vertical bar G vertical bar epsilon F-X (i.e. the order vertical bar G vertical bar of G is relatively prime to the characteristic of F)
DNA fusion gene vaccination mobilizes effective anti-leukemic cytotoxic T lymphocytes from a tolerized repertoire
No full textThe majority of known human tumor-associated antigens derive from non-mutated self proteins. T cell tolerance, essential to prevent autoimmunity, must therefore be cautiously circumvented to generate cytotoxic T cell responses against these targets. Our strategy uses DNA fusion vaccines to activate high levels of peptide-specific CTL. Key foreign sequences from tetanus toxin activate tolerance-breaking CD4+ T cell help. Candidate MHC class Ibinding tumor peptide sequences are fused to the C terminus for optimal processing and presentation. To model performance against a leukemia-associated antigen in a tolerized setting, we constructed a fusion vaccine encoding an immunodominant CTL epitopederived from Friend murine leukemia virus gag protein (FMuLVgag) and vaccinated tolerant FMuLVgag-transgenic (gag-Tg) mice. Vaccination with the construct induced epitopespecificIFN-c-producing CD8+ T cells in normal and gag-Tg mice. The frequency and avidity of activated cells were reduced in gag-Tg mice, and no autoimmune injury resulted. However, these CD8+ T cells did exhibit gag-specific cytotoxicity in vitro and in vivo. Also, epitope-specific CTL killed FBL-3 leukemia cells expressing endogenous FMuLVgag antigen and protected against leukemia challenge in vivo. These results demonstrate a simple strategy to engage anti-microbial T cell help to activate epitope-specific polyclonal CD8+ T cell responses from a residual tolerized repertoire
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