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Lung inflammation is induced by renal ischemia and reperfusion injury as part of the systemic inflammatory syndrome

CAMPANHOLLE, G.; LANDGRAF, R. G.; GONCALVES, G. M.; PAIVA, V. N.; MARTINS, J. O.; WANG, P. H. M.; MONTEIRO, R. M. M.; SILVA, R. C.; CENEDEZE, M. A.; TEIXEIRA, V. P. A.; REIS, M. A.; PACHECO-SILVA, A.; JANCAR, S.; CAMARA, Niels Olsen Saraiva
Fonte: SPRINGER BASEL AG Publicador: SPRINGER BASEL AG
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
85.49%
Ischemia and reperfusion injury (IRI) are mainly caused by leukocyte activation, endothelial dysfunction and production of reactive oxygen species. Moreover, IRI can lead to a systemic response affecting distant organs, such as the lungs. The objective was to study the pulmonary inflammatory systemic response after renal IRI. Male C57Bl/6 mice were subjected to 45 min of bilateral renal ischemia, followed by 4, 6, 12, 24 and 48 h of reperfusion. Blood was collected to measure serum creatinine and cytokine concentrations. Bronchoalveolar lavage fluid (BALF) was collected to determine the number of cells and PGE(2) concentration. Expressions of iNOS and COX-2 in lung were determined by Western blot. Gene analyses were quantified by real time PCR. Serum creatinine increased in the IRI group compared to sham mainly at 24 h after IRI (2.57 +/- A 0.16 vs. 0.43 +/- A 0.07, p < 0.01). The total number of cells in BAL fluid was higher in the IRI group in comparison with sham, 12 h (100 x 10(4) +/- A 15.63 vs. 18.1x10(4) +/- A 10.5, p < 0.05) 24 h (124 x 10(4) +/- A 8.94 vs. 23.2x10(4) +/- A 3.5, p < 0.05) and 48 h (79 x 10(4) +/- A 15.72 vs. 22.2 x 10(4) +/- A 4.2, p < 0.05), mainly by mononuclear cells and neutrophils. Pulmonary COX-2 and iNOS were up-regulated in the IRI group. TNF-alpha...

Fibroblast growth factor 2 restrains ras-driven proliferation of malignant cells by triggering RhoA-mediated senescence

COSTA, Erico T.; FORTI, Fabio L.; MATOS, Tatiana G. F.; DERMARGOS, Alexandre; NAKANO, Fabio; SALOTTI, Jacqueline; ROCHA, Katia M.; ASPRINO, Paula F.; YOSHIHARA, Celina K.; KOGA, Marianna M.; ARMELIN, Hugo A.
Fonte: AMER ASSOC CANCER RESEARCH Publicador: AMER ASSOC CANCER RESEARCH
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
75.35%
Fibroblast growth factor 2 (FGF2) is considered to be a bona fide oncogenic factor, although results from our group and others call this into question. Here, we report that exogenous recombinant FGF2 irreversibly inhibits proliferation by inducing senescence in Ras-dependent malignant mouse cells, but not in immortalized nontumorigenic cell lines. We report the following findings in K-Ras-dependent malignant YI adrenocortical cells and H-Ras V12-transformed BALB-3T3 fibroblasts: (a) FGF2 inhibits clonal growth and tumor onset in nude and immunocompetent BALB/c mice, (b) FGF2 irreversibly blocks the cell cycle, and (c) FGF2 induces the senescence-associated -galactosidase with no accompanying signs of apoptosis or necrosis. The tyrosine kinase inhibitor PD173074 completely protected malignant cells from FGF2. In Yl adrenal cells, reducing the constitutively high levels of K-Ras-GTP using the dominant-negative RasN17 mutant made cells resistant to FGF2 cytotoxicity. In addition, transfection of the dominant-negative RhoA-N19 into either YI or 3T3-B61 malignant cell lines yielded stable clonal transfectants that were unable to activate RhoA and were resistant to the FGF2 stress response. We conclude that in Rasdependent malignant cells...

Spectroscopic and theoretical studies of some N-methoxy-N-methyl-2-[(4 `-substituted) phenylthio]propanamides

OLIVATO, Paulo R.; DOMINGUES, Nelson L. C.; MONDINO, Mirta G.; TORMENA, Claudio F.; RITTNER, Roberto; COLLE, Maurizio Dal
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
65.57%
The analysis of the IR carbonyl band of the N-methoxy-N-methyl-2-[(4`-substituted)phenylthio]propanamides Y-PhSCH(Me)C(O)N(OMe)Me (Y=OMe 1, Me 2, H 3, Cl 4, NO(2) 5), supported by B3LYP/cc-pVDZ calculations of 3, indicated the existence of two gauche conformers (g(1) and g(2)), the g(1) conformer being the more stable and the less polar one (in gas phase and in solution). Both conformers are present in solution of the polar solvents (CH(2)Cl(2) and CH(3)CN) for 1-5 and in solution of the less polar solvent (CHCl(3)) for 1-4, while only the g(1) conformer is present in solution of non polar solvents (n-C(6)H(14) and CCl(4)) and in solution of CHCl(3) for 5. NBO analysis shows that both the sigma(C-S) -> pi*(C=O) (hyperconjugative) and the pi(C=O) -> sigma*(C-S) orbital interactions contribute almost to the same extent for the stabilization of g(1) and g(2) conformers. The pi*(C=O) -> sigma*(C-S), n(S) -> pi*(C=O) and the n(S) -> pi*(C=O) orbital interactions stabilize more the g(1) conformer than the g(2) one. Moreover, the suitable geometry of the g(1) conformer leads to its stabilization through the LP(O2) -> sigma*(C8-H11) orbital interaction (hydrogen bond) along with the strong O([CO])(delta-) center dot center dot center dot H([O-Ph])(delta+) electrostatic interaction. On the other hand...

Estudo computacional de [2.2]ciclofanos; Computational Study of [2.2]cyclophanes

Caramori, Giovanni Finoto
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 01/09/2006 PT
Relevância na Pesquisa
75.53%
Neste trabalho foram estudados computacionalmente os [2.2]ciclofanos ([2.2]paraciclofano (1), anti-[2.2]metaciclofano (2a), sin-[2.2]metaciclofano (2b) e [2.2]metaparaciclofano (3)), que são os [2n]ciclofanos mais simples, contendo dois anéis fenílicos conectados por duas pontes etilênicas. Os ciclofanos têm apresentado inúmeras aplicações importantes, podendo atuar como auxiliares em sínteses assimétricas e como catalisadores que simulam funções enzimáticas, apresentando seletividade em relação aos substratos. Eles são empregados tanto em químicab supramolecular quanto em áreas biomédicas. Estudos que empregam ressonância de spin eletrônico ou que investigam propriedades ópticas não-lineares dos [2.2]ciclofanos indicam que os mesmos apresentam interações transanulares, que ocorrem através de recobrimento direto entre orbitais pertencentes a anéis diferentes, through-space, ou através de recobrimento entre orbitais dos anéis e das pontes, through-bond. As interações transanulares possuem um papel fundamental na química dos ciclofanos, alterando o comportamento reacional destes compostos e as transições espectroscópicas. Apesar dos métodos de preparação de ciclofanos, desde os mais simples aos mais complexos...

Preparação de eletrodos quimicamente modificados com sílicas organofuncionalizadas, aplicados à detecção de micropoluentes emergentes

Barcelos, Hernane de Toledo
Fonte: Universidade de Brasília Publicador: Universidade de Brasília
Tipo: Tese
POR
Relevância na Pesquisa
75.47%
Tese (doutorado)—Universidade de Brasília, Instituto de Química, 2013.; Neste trabalho foram preparadas duas sílicas quimicamente modificadas, a partir da sílica gel 60, com área superficial específica (SBET) de 391,93 m2 g-1. As sílicas foram inicialmente modificadas via reação de silanização com a molécula de 3-aminopropiltrietóxissilano (APTES) formando o material denominado SiN, que em seguida foi funcionalizado separadamente com o pesticida ácido-2,4-diclorofenoxiacético (2,4-D) e com glutaraldeído por rota heterogênea, obtendo-se os materiais funcionalizados SiD e SiG respectivamente. Os materiais foram caracterizados através de análises elementares de C, H e N, medidas de porosidade, análises termogravimétricas, espectroscopia na região de infravermelho e RMN de 29Si e 13C. As análises elementares indicaram as quantidades de e 1,15 10-3 mol 2,4-D por grama de SiD e 1,57 10-3 mol de glutaraldeído por grama de SiG. As medidas de área superficial, volume de poros e de diâmetro médio de poros dos materiais, mostraram uma diminuição em relação ao material de partida. Os espectros de FTIR apresentaram bandas características dos grupos imobilizados na superfície das sílicas. As superfícies funcionalizadas (SiD e SiG) foram utilizadas na confecção de eletrodos de pasta de carbono quimicamente modificados e estes eletrodos foram utilizados na detecção eletroquímica dos micropoluentes 2...

Diffusion coefficients of 2,2,2-trifluoroethanol/water mixtures

Pereira, Luís A. M.; Ramalho, João P. P.; Carvalho, Alfredo J. P.; Morgado, Pedro; Filipe, Eduardo J. M.; Martins, Luís F. G.
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Aula
ENG
Relevância na Pesquisa
85.41%
Aqueous mixtures of 2,2,2-trifluoroethanol have received significant attention in the last years because their applications, such as working fluid in Rankine cycle thermal engines or as solvent in studies of protein stability (protein folding). From the fundamental point of view, fluoroalcohols have an amphyphile character, due to the simultaneous presence of a hydrophobic (and alkane-phobic) fluorinated surface and a hydroxyl group. Mixtures of 2,2,2-trifluoroethanol with hydrogenated alcohols were studied recently in our research group (experimental determination of pVT surfaces as well as thermal, volumetric and structural properties by computer simulation) [1]. In the case of 2,2,2-trifluoroethanol/water this study suggested a preference of cross hydrogen bond. Hydrogen bonds play a determinant role in the structure of aqueous mixtures of alcohols, and should influence the dynamic properties of binary systems of fluorinated alcohols with water. The goal of this work is to study a dynamic property (diffusion coefficient) of binary mixtures 2,2,2-trifluoroethanol/water, comparing the results with equilibrium and structural properties already known for this and related systems.

Resposta humoral na infecção por VIH-2 : impacto no diagnóstico, prevenção e evolução viral

Marcelino, José Maria, 1959-
Fonte: Universidade de Lisboa Publicador: Universidade de Lisboa
Tipo: Tese de Doutorado
Publicado em //2011 POR
Relevância na Pesquisa
95.43%
Tese de doutoramento, Ciências Biomédicas (Ciências Biopatalógicas), Universidade de Lisboa, Faculdade de Medicina, 2011; Os indivíduos infectados pelo VIH-2 progridem mais lentamente do que os infectados pelo VIH-1, e estima-se que mais de 95% dos indivíduos infectados por VIH-2 estejam incluídos na definição clínica de long-term nonprogressors. Esta diferença faz do VIH-2 um potencial modelo de estudo de uma infecção VIH atenuada que pode fornecer uma visão única da patogénese da infecção VIH-1. Até ao momento, os mecanismos responsáveis pelo fenótipo atenuado do VIH-2 não são bem conhecidos. A carga viral plasmática é inferior nos indivíduos infectados pelo VIH-2 do que pelo VIH-1. Isto sugere que a principal diferença entre os dois tipos de VIH pode estar no grau de replicação viral, e presume que a resposta imunológica do hospedeiro contribui directamente para um controlo mais eficiente da replicação do VIH-2. Actualmente não existem dúvidas de que a maioria dos indivíduos infectados pelo VIH-1 ou VIH-2 produzem anticorpos neutralizantes (AcNT) autólogos e heterólogos. Contudo, existe alguma controvérsia sobre se os AcNT controlam de facto a replicação viral, uma vez que na maioria dos casos não se observa correlação inversa entre o título de AcNT e a carga viral plasmática. Na realidade...

Dengue type 2 outbreak in the south of the State of Bahia, Brazil: laboratorial and epidemiological studies

Nogueira,Rita M. R.; Miagostovich,Marize P.; Schatzmayr,Hermann G.; Moraes,Gerusa C.; Cardoso,Floriene M. A.; Ferreira,Janete; Cerqueira,Vera; Pereira,Manuel
Fonte: Instituto de Medicina Tropical Publicador: Instituto de Medicina Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/1995 EN
Relevância na Pesquisa
75.35%
During March 1994 cases of a exanthematic acute disease were reported in the municipalities of Itagemirim, Eunápolis and Belmonte, state of Bahia. Dengue fever was confirmed by serology (MAC-ELISA) and by dengue virus type 2 isolation, genotype Jamaica. Signs and symptoms of classic dengue fever were observed with a high percentual of rash (73.8%) and pruritus (50.5%). Major haemorrhagic manifestations were unfrequent and only bleeding gum was reported. Dengue virus activity spreaded rapidly to important tourism counties like Porto Seguro, Ilhéus, Santa Cruz de Cabrália, Prado, Alcobaça and others, representing a risk for the spreading of dengue virus into the country and abroad.

Impaired acuity of the approximate number system in 22q11.2 microdeletion syndrome

Oliveira,Lívia F. S.; Santos,Amanda O; Vianna,Gabrielle S; Ninno,Camila Q. M. S. Di; Giacheti,Célia M; Carvalho,Maria R. S; Wood,Guilherme; Pinheiro-Chagas,Pedro; Haase,Vitor G
Fonte: Pontificia Universidade Católica do Rio de Janeiro; Universidade de Brasília; Universidade de São Paulo Publicador: Pontificia Universidade Católica do Rio de Janeiro; Universidade de Brasília; Universidade de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
Relevância na Pesquisa
75.4%
A magnitude comparison deficit has been frequently observed in velocardiofacial syndrome (Del22q11.2). We hypothesized that this deficit extends to impairments in the acuity of the approximate number system (ANS). Three groups of children aged 8-14 years were investigated: Del22q11.2 children (n = 12), low cognitive ability children (LCA; n = 12), and matched typically developing children (TD; n = 28). All children were assessed with a simple reaction time task and symbolic and nonsymbolic number comparison tasks. To estimate the acuity of the ANS, the Weber fraction (w) was calculated from the nonsymbolic comparison task. The Del22q11.2 group exhibited a significantly higher w compared with the other groups. Importantly, no significant differences were found in w between the TD and LCA groups. The performance pattern of the Del22q11.2 group was similar to the TD group in the symbolic comparison task, and both of these groups had better performance than the LCA group. The impairment of ANS acuity observed in individuals with Del22q11.2 cannot be explained by deficits in general processing speed because no significant group differences were found in the simple reaction time task. These results suggest that lower acuity of the ANS should be added to the behavioral phenotype of Del22q11.2. The absence of impaired ANS acuity in the LCA group is consistent with the hypothesis that number sense is a relatively specific and autonomous domain. Investigations of low ANS acuity in mathematics learning difficulties and Del22q11.2 should be intensified.

Amino acid substitutions in the Dictyostelium G alpha subunit G alpha 2 produce dominant negative phenotypes and inhibit the activation of adenylyl cyclase, guanylyl cyclase, and phospholipase C.

Okaichi, K; Cubitt, A B; Pitt, G S; Firtel, R A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1992 EN
Relevância na Pesquisa
65.59%
Previous studies have demonstrated that the Dictyostelium G alpha subunit G alpha 2 is essential for the cAMP-activation of adenylyl cyclase and guanylyl cyclase and that g alpha 2 null mutants do not aggregate. In this manuscript, we extend the analysis of the function of G alpha 2 in regulating downstream effectors by examining the in vivo developmental and physiological phenotypes of both wild-type and g alpha 2 null cells carrying a series of mutant G alpha 2 subunits expressed from the cloned G alpha 2 promoter. Our results show that wild-type cells expressing G alpha 2 subunits carrying mutations G40V and Q208L in the highly conserved GAGESG (residues 38-43) and GGQRS (residues 206-210) domains, which are expected to reduce the intrinsic GTPase activity, are blocked in multicellular development. Analysis of down-stream effector pathways essential for mediating aggregation indicates that cAMP-mediated activation of guanylyl cyclase and phosphatidylinositol-phospholipase C (PI-PLC) is almost completely inhibited and that there is a substantial reduction of cAMP-mediated activation of adenylyl cyclase. Moreover, neither mutant G alpha 2 subunit can complement g alpha 2 null mutants. Expression of G alpha 2(G43V) and G alpha 2(G207V) have little or no effect on the effector pathways and can partially complement g alpha 2 null cells. Our results suggest a model in which the dominant negative phenotypes resulting from the expression of G alpha 2(G40V) and G alpha 2(Q208L) are due to a constitutive adaptation of the effectors through a G alpha 2-mediated pathway. Analysis of PI-PLC in g alpha 2 null mutants and in cell lines expressing mutant G alpha 2 proteins also strongly suggests that G alpha 2 is the G alpha subunit that directly activates PI-PLC during aggregation. Moreover...

N-(4-Chloro­phenyl­sulfon­yl)-2,2,2-tri­methyl­acetamide

Gowda, B. Thimme; Foro, Sabine; Sowmya, B. P.; Nirmala, P. G.; Fuess, Hartmut
Fonte: International Union of Crystallography Publicador: International Union of Crystallography
Tipo: Artigo de Revista Científica
Publicado em 19/06/2008 EN
Relevância na Pesquisa
75.41%
In the crystal structure of the title compound (N4CPSTMAA), C11H14ClNO3S, the conformations of the N—H and C=O bonds in the amide group are anti to each other, similar to those observed in N-phenyl­sulfonyl-2,2,2-trimethyl­acetamide (NPSTMAA) and 2,2,2-trimethyl-N-(4-methyl­phenyl­sulfon­yl)acetamide (N4MPSTMAA). The bond parameters in N4CPSTMAA are similar to those in NPSTMAA, N4MPSTMAA, N-aryl-2,2,2-trimethyl­acetamides and 4-chloro­benzene­sulfonamide. The –SNHCOC– unit including the amide group is essentially planar and makes a dihedral angle of 82.2 (1)° with the benzene ring, comparable to the values of 79.1 (1) and 71.2 (1)° in NPSTMAA and N4MPSTMAA, respectively. The mol­ecules in N4CPSTMAA are linked into a chain by inter­molecular N—H⋯O hydrogen bonds.

Aplicação pós-colheita de aminoetoxivinilglicina e armazenamento refrigerado de manga ?Tommy Atkins?.

SANTOS, A. C. N. dos; LIMA, M. A. C. de; TRINDADE, D. C. G. da; RIBEIRO, T. P.; SOUZA, S. O. de; COSTA, A. C. S.; AMARIZ, A.
Fonte: In: JORNADA DE INICIAÇÃO CIENTÍFICA DA EMBRAPA SEMI-ÁRIDO, 2., 2007, Petrolina. Anais... Petrolina: Embrapa Semi-Árido, 2007. Publicador: In: JORNADA DE INICIAÇÃO CIENTÍFICA DA EMBRAPA SEMI-ÁRIDO, 2., 2007, Petrolina. Anais... Petrolina: Embrapa Semi-Árido, 2007.
Tipo: Artigo em anais de congresso (ALICE)
PT_BR
Relevância na Pesquisa
75.47%
Neste trabalho, avaliou-se o efeito da aplicação pós-colheita de aminoetoxivinilgilina (AVG) em mangas ?Tommy Atkins? armazenadas durante 20 dias sob refrigeração (11,6 ± 3,9ºC e 87 ± 6% UR), seguidas de 6 dias em temperatura ambiente (23,2 ± 2,1ºC e 57 ± 8% UR). Os frutos foram imersos em solução de AVG, nas concentrações: 0, 100, 200 e 300 g.g-1 e mantidos em câmara de refrigeração. O delineamento experimental foi inteiramente casualizado, em fatorial 4x5 (doses de AVG x tempo de armazenamento), com quatro repetições de quatro frutos cada uma. A acidez titulável, a firmeza, a cor da casca, a luminosidade da polpa e a aparência dos frutos decresceram apenas em função do tempo. A aplicação pós-colheita de 300 mg.g-1 de AVG em manga ?Tommy Atkins? foi eficiente em reduzir a perda de massa e a intensidade da cor da polpa, com influência limitada no teor de sólidos solúveis.; 2007

Parameterized complexity dichotomy for $(r,\ell)$-Vertex Deletion

Baste, Julien; Faria, Luerbio; Klein, Sulamita; Sau, Ignasi
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 21/04/2015
Relevância na Pesquisa
75.51%
For two integers $r, \ell \geq 0$, a graph $G = (V, E)$ is an $(r,\ell)$-graph if $V$ can be partitioned into $r$ independent sets and $\ell$ cliques. In the parameterized $(r,\ell)$-Vertex Deletion problem, given a graph $G$ and an integer $k$, one has to decide whether at most $k$ vertices can be removed from $G$ to obtain an $(r,\ell)$-graph. This problem is NP-hard if $r+\ell \geq 1$ and encompasses several relevant problems such as Vertex Cover and Odd Cycle Transversal. The parameterized complexity of $(r,\ell)$-Vertex Deletion was known for all values of $(r,\ell)$ except for $(2,1)$, $(1,2)$, and $(2,2)$. We prove that each of these three cases is FPT and, furthermore, solvable in single-exponential time, which is asymptotically optimal in terms of $k$. We consider as well the version of $(r,\ell)$-Vertex Deletion where the set of vertices to be removed has to induce an independent set, and provide also a parameterized complexity dichotomy for this problem.; Comment: 16 pages, 2 figures

Predictions for g-2 of the muon and alpha_QED(M_Z^2)

Hagiwara, K.; Martin, A. D.; Nomura, Daisuke; Teubner, T.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
75.54%
We calculate (g-2) of the muon and the QED coupling alpha(M_Z^2), by improving the determination of the hadronic vacuum polarization contributions and their uncertainties. We include the recently re-analysed CMD-2 data on e^+e^- -> pi^+ pi^-. We carefully combine a wide variety of data for the e^+e^- production of hadrons, and obtain the optimum form of R(s) = sigma_had^0(s)/sigma_pt(s), together with its uncertainty. Our results for the hadronic contributions to g-2 of the muon are a_mu^(had, LO) = (692.4 +- 5.9_exp +- 2.4_rad) * 10^(-10) and a_mu^(had, NLO) = (-9.8 +- 0.1_exp +- 0.0_rad) * 10^(-10), and for the QED coupling Delta alpha^(5)_had (M_Z^2)= (275.5 +- 1.9_exp +- 1.3_rad) * 10^(-4). These yield (g-2)/2 = 0.00116591763(74), which is about 2.4 sigma below the present world average measurement, and alpha(M_Z^2)^(-1) = 128.954 +- 0.031. We compare our (g-2) value with other predictions and, in particular, make a detailed comparison with the latest determination of (g-2) by Davier et al.; Comment: 83 pages, 10 Tables, LaTeX, 28 PostScript figures included. Electromagnetic contributions updated; two Refs. added and typos corrected. Version to appear in Phys. Rev. D

Fourier meets M\"{o}bius: fast subset convolution

Björklund, Andreas; Husfeldt, Thore; Kaski, Petteri; Koivisto, Mikko
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 21/11/2006
Relevância na Pesquisa
75.54%
We present a fast algorithm for the subset convolution problem: given functions f and g defined on the lattice of subsets of an n-element set N, compute their subset convolution f*g, defined for all S\subseteq N by (f * g)(S) = \sum_{T \subseteq S}f(T) g(S\setminus T), where addition and multiplication is carried out in an arbitrary ring. Via M\"{o}bius transform and inversion, our algorithm evaluates the subset convolution in O(n^2 2^n) additions and multiplications, substantially improving upon the straightforward O(3^n) algorithm. Specifically, if the input functions have an integer range {-M,-M+1,...,M}, their subset convolution over the ordinary sum-product ring can be computed in O^*(2^n log M) time; the notation O^* suppresses polylogarithmic factors. Furthermore, using a standard embedding technique we can compute the subset convolution over the max-sum or min-sum semiring in O^*(2^n M) time. To demonstrate the applicability of fast subset convolution, we present the first O^*(2^k n^2 + n m) algorithm for the minimum Steiner tree problem in graphs with n vertices, k terminals, and m edges with bounded integer weights, improving upon the O^*(3^k n + 2^k n^2 + n m) time bound of the classical Dreyfus-Wagner algorithm. We also discuss extensions to recent O^*(2^n)-time algorithms for covering and partitioning problems (Bj\"{o}rklund and Husfeldt...

Hadronic light-by-light scattering in the muon g-2: impact of proposed measurements of the (pi^0 -> gamma gamma) decay width and the (gamma^* gamma -> pi^0) transition form factor with the KLOE-2 experiment

Nyffeler, Andreas
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 25/06/2013
Relevância na Pesquisa
75.5%
The calculation of the hadronic light-by-light scattering contribution to the muon g-2 currently relies entirely on models. Measurements of the form factors which describe the interactions of hadrons with photons can help to constrain the models and reduce the uncertainty in a_{mu}(had. LbyL) = (116 \pm 40) x 10^{-11}. In the dominant pion-exchange contribution, the form factor F_{{pi^0}^*gamma^*gamma^*}((q_1 + q_2)^2, q_1^2, q_2^2) with an off-shell pion enters. In general, measurements of the transition form factor F(Q^2) = F_{{pi^0}^*gamma^*gamma^*}(m_{pi}^2, -Q^2, 0) are only sensitive to a subset of the model parameters. Thus, having a good description for F(Q^2) is only necessary, not sufficient, to determine a_{mu}(LbyL; pi^0). Simulations have shown that measurements at KLOE-2 should be able to determine the (pi^0 -> gamma gamma) decay width to 1% statistical precision and the transition form factor for small space-like momenta, 0.01 GeV^2 < Q^2 < 0.1 GeV^2, to 6% precision. In the two-loop integral for the pion-exchange contribution the relevant regions of momenta are in the range 0 - 1.5 GeV. With the (pi^0 -> gamma gamma) decay width from the PDG [PrimEx] and current data for the transition form factor, the error on a_{mu}(LbyL; pi^0) is (\pm 4 x 10^{-11}) [\pm 2 x 10^{-11}]...

The g-2 of the Muon in Localized Gravity Models

Davoudiasl, H.; Hewett, J. L.; Rizzo, T. G.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
75.5%
The (g-2) of the muon is well known to be an important model building constraint on theories beyond the Standard Model. In this paper, we examine the contributions to $(g-2)_\mu$ arising in the Randall-Sundrum model of localized gravity for the case where the Standard Model gauge fields and fermions are both in the bulk. Using the current experimental world average measurement for $(g-2)_\mu$, we find that strong constraints can be placed on the mass of the lightest gauge Kaluza-Klein excitation for a narrow part of the allowed range of the assumed universal 5-dimensional fermion mass parameter, $\nu$. However, employing both perturbativity and fine-tuning constraints we find that we can further restrict the allowed range of the parameter $\nu$ to only one fourth of its previous size. The scenario with the SM in the RS bulk is thus tightly constrained, being viable for only a small region of the parameter space.; Comment: 16 pages, 2 figs, LaTex, Additional discussion added

Isometric $G_{2(2)}$-actions on pseudo-Riemannian manifolds with dimension at most $21$

Quiroga-Barranco, R.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 22/10/2015
Relevância na Pesquisa
85.53%
Let $G_{2(2)}$ be the non-compact connected simple Lie group of type $G_2$ over $\mathbb{R}$, and let $M$ be a connected analytic complete pseudo-Riemannian manifold that admits an isometric $G_{2(2)}$-action with a dense orbit. For the case $\dim(M) \leq 21$, we provide a complete description of the manifold $M$, its geometry and its $G_{2(2)}$-action. The latter are always given in terms of a Lie group geometry related to $G_{2(2)}$, and in one case $M$ is essentially the quotient of $\mathrm{SO}_0(3,4)$ by a lattice.; Comment: arXiv admin note: substantial text overlap with arXiv:1503.01483

L-functions of $S_3(\G_2(2,4,8))$

Okazaki, Takeo
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 09/08/2010
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75.49%
The space of Siegel cuspforms of degree $2$ of weight $3$ with respect to the congruence subgroup $\G_2(2,4,8)$ was studied by van Geemen and van Straten in Math. computation. {\bf 61} (1993). They showed the space is generated by six-tuple products of Igusa $\th$-constants, and all of them are Hecke eigenforms. They gave conjecture on the explicit description of the Andrianov $L$-functions. In J. Number Theory. {\bf 125} (2007), we proved some conjectures by showing that some products are obtained by the Yoshida lift, a construction of Siegel eigenforms. But, other products are not obtained by the Yoshida lift, and our technique did not work. In this paper, we give proof for such products. As a consequence, we determine automorphic representations of O(6), and give Hermitian modular forms of SU(2,2) of weight $4$. Further, we give non-holomorphic differential threeforms on the Siegel threefold with respect to $\G_2(2,4,8)$.

2-Heptanone Produces Sensorial-Emotional Changes, Depending on Length of Exposure

Gutiérrez-García,Ana G; Contreras,Carlos M; Mendoza-López,Remedios
Fonte: Revista Costarricense de Psicología Publicador: Revista Costarricense de Psicología
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2015 EN
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2-Heptanone is an alarm pheromone contained in some human fluids, but its role is unknown in chemical communication. In part one of this study, a sample of 24 women provided urine specimens taken around their supposed ovulation days, and a second sample 12 days later. As exclusion criteria, women with anxiety (based on the State-Trait Anxiety Inventory, Spielberger), mood disorders (based on the Clinical Diagnosis of Depression Questionnaire), and premenstrual dysphoric disorder (based on the Daily Symptoms Report) were not included in the study. Gas chromatography/mass spectrometry indicated that urinary 2-heptanone content was increased approximately two-fold during pre-menstruation compared with the days around ovulation. In part two of this study, 141 male and female volunteers, sniffed this ketone and with a simple questionnaire it was determined that the longest tested duration (180 s) of sniffing 2-heptanone lowered the acceptance of sniffing this ketone again, compared with the shorter sniffing durations (5 and 60 s), with no differences between sexes. The increased con­centration of 2-heptanone during the day before menstruation may be considered as part of the functional changes preceding menstruation and sniffing this ketone may produce sensorial-emotional changes depending on time of sniffing...