451 research outputs found
The Drosophila Gene abnormal spindle Encodes a Novel Microtubule-associated Protein That Associates with the Polar Regions of the Mitotic Spindle
abnormal spindle, a gene required for normal spindle structure and function in Drosophila melanogaster, lies immediately adjacent the gene tolloid at 96A/B. It encodes a 220-kD polypeptide with a predicted pI of 10.8. The recessive mutant allele asp1 directs the synthesis of a COOH terminally truncated or internally deleted peptide of ∼124 kD. Wild-type Asp protein copurifies with microtubules and is not released by salt concentrations known to dissociate most other microtubule-associated proteins. The bacterially expressed NH2-terminal 512-amino acid peptide, which has a number of potential phosphorylation sites for p34cdc2 and MAP kinases, strongly binds to microtubules. The central 579-amino acid segment of the molecule contains one short motif homologous to sequences in a number of actin bundling proteins and a second motif present at the calmodulin binding sites of several proteins. Immunofluorescence studies show that the wild-type Asp protein is localized to the polar regions of the spindle immediately surrounding the centrosome. These findings are discussed in relation to the known spindle abnormalities in asp mutants
A plastid DNA phylogeny of Dasymaschalon (Annonaceae) and allied genera: Evidence for generic non-monophyly and the parallel evolutionary loss of inner petals
Dasymaschalon and the closely related genera Desmos, Friesodielsia and Monanthotaxis together comprise ca. 170 species of trees, shrubs and woody climbers distributed in tropical Africa and tropical Asia. These genera form the desmoid clade, which, because of the presence of diverse flower and fruit syndromes including different types of pollination chambers and moniliform monocarps, offers an opportunity to investigate potentially ecologically significant shifts in flower and fruit characters. Despite its morphological diversity, however, generic delimitation within the desmoid clade is problematic and the intergeneric relationships of the constituent genera are only poorly understood. Bayesian, maximum likelihood and maximum parsimony analyses of plastid DNA sequence data ( matK, psbA-trnH, ndhF, rbcL, trnL-F; ca. 5.4 kb; 52 taxa) were used to clarify phylogenetic relationships within the desmoid clade. The evolution and taxonomic utility of selected fruit and flower characters was investigated with likelihood and parsimony ancestral character reconstructions. The results indicate problems in the current delimitations of Dasymaschalon and Friesodielsia. Friesodielsia as currently circumscribed is polyphyletic, with African Friesodielsia species allied to the African genus Monanthotaxis, and only distantly related to Asian representatives. The majority of Dasymaschalon species form a strongly supported clade, but three species are more closely related to Asian species of Friesodielsia. Ancestral character reconstructions indicate that seed number and monocarp shape are of limited value in generic circumscriptions, and that the three-petalled corolla characteristic of Dasymaschalon evolved independently twice within the desmoid clade. Disruptions to homeotic gene expression or strong selective pressure for a partial enclosure of the mature stamens and carpels by the corolla are hypothesised to underlie the parallel evolution of pollination chambers formed by outer petal homologues subsequent to inner petal los
A passagem para o abismo entre a natureza e a liberdade : uma investigação do sistema crítico de Immanuel Kant a partir da Crítica da faculdade do juízo
A filosofia Crítica de Immanuel Kant pode ser dividida em três momentos fundamentais, cada um deles representado por uma obra. Em resumo, a primeira delas, a Crítica da Razão Pura, é uma investigação sobre os limites do conhecimento teórico que, por um lado, exibe as bases transcendentais de constituição da natureza, que legitimam os conhecimentos apodíticos das ciências duras nesse domínio, e, por outro, limita o conhecimento teórico aos objetos da experiência, embora confirme que não há contradição em pensar como possível uma causalidade livre, a liberdade. A segunda obra, a Crítica da Razão Prática, confirmará a realidade prática da idéia de liberdade, através do reconhecimento de um domínio que a razão ocupa com as suas próprias leis, que determinam que a vontade se dirija para a construção do que deve ser uma humanidade livre. Contudo, considerando que o livre-arbítrio permite que a lei moral não seja atendida, e o mal radical da natureza humana que nas suas escolhas se inclina para o não cumprimento da lei, as idéias da imortalidade da alma e de Deus, que nos limites da primeira Crítica só puderam ser reconhecidas como legítimas por sua função regulativa para o conhecimento teórico, são atestadas como um postulado necessário da razão prática para a possibilidade do Sumo Bem, apesar de não resultarem em um conhecimento sobre a natureza, domínio onde devem ser realizadas historicamente as exigências da razão prática. A terceira Crítica, intitulada Crítica da Faculdade de Julgar, revela em sua Introdução, ao declarar que restou um abismo entre os conceitos de natureza e de liberdade, pela heterogeneidade de suas leis, o interesse sistemático na Faculdade de Julgar como a via de possibilidade para a passagem por sobre o abismo. A presente pesquisa apresenta uma interpretação sobre as duas primeiras obras Críticas para mostrar a constituição de cada um dos dois domínios do conhecimento filosófico e a limitação destas obras no que se refere à exigência da razão sobre a possibilidade da consumação do fim terminal: a realização moral da humanidade na natureza. Em seguida, interpreta a terceira Crítica, para mostrar como a Faculdade de Julgar Estética, orientada por um princípio próprio de uma conformidade a fins da natureza, ao julgar a beleza de certos objetos da natureza e das belas-artes, revela que a natureza, para além dos limites mecânicos do entendimento, convém à harmonia das faculdades do conhecimento, o que a razão toma analogicamente como conforme aos seus interesses morais. Além disso, a consideração sobre a capacidade de criação da arte bela pelo gênio, e da imaginação na apresentação de idéias estéticas, alimentam a esperança sobre a capacidade humana para satisfazer as exigências da razão. Temos assim, por meio da Faculdade de Julgar Estética e da sua ligação com o sentimento de prazer e desprazer, uma experiência estética que realiza a passagem, ao ampliar, pelo sentimento ligado às faculdades de conhecimento, o conceito de natureza apresentado pela primeira Crítica, e aproximar a natureza da liberdade, permitindo integrar as duas partes da filosofia em um sistema completo.CAPES/CNP
Far-Ultraviolet and Far-Infrared Bivariate Luminosity Function of Galaxies: Complex Relation between Stellar and Dust Emission
Far-ultraviolet (FUV) and far-infrared (FIR) luminosity functions (LFs) of
galaxies show a strong evolution from to , but the FIR LF
evolves much stronger than the FUV one. The FUV is dominantly radiated from
newly formed short-lived OB stars, while the FIR is emitted by dust grains
heated by the FUV radiation field. It is known that dust is always associated
with star formation activity. Thus, both FUV and FIR are tightly related to the
star formation in galaxies, but in a very complicated manner. In order to
disentangle the relation between FUV and FIR emissions, we estimate the UV-IR
bivariate LF (BLF) of galaxies with {\sl GALEX} and {\sl AKARI} All-Sky Survey
datasets. Recently we invented a new mathematical method to construct the BLF
with given marginals and prescribed correlation coefficient. This method makes
use of a tool from mathematical statistics, so called "copula". The copula
enables us to construct a bivariate distribution function from given marginal
distributions with prescribed correlation and/or dependence structure. With
this new formulation and FUV and FIR univariate LFs, we analyze various FUV and
FIR data with {\sl GALEX}, {\sl Spitzer}, and {\sl AKARI} to estimate the UV-IR
BLF. The obtained BLFs naturally explain the nonlinear complicated relation
between FUV and FIR emission from star-forming galaxies. Though the faint-end
of the BLF was not well constrained for high- samples, the estimated linear
correlation coefficient was found to be very high, and is remarkably
stable with redshifts (from 0.95 at to 0.85 at ). This implies
the evolution of the UV-IR BLF is mainly due to the different evolution of the
univariate LFs, and may not be controlled by the dependence structure.Comment: 10 pages, 7 figures, Earth, Planets and Space, in pres
Factors associated with adherence to immunomodulator treatment in people with multiple sclerosis
Abstract To determine the association between factors and adherence to immunomodulator treatment in people with multiple sclerosis treated in reference centers. Cross-sectional study conducted with 188 people who used immunomodulators in three reference centers in Ceará from March to July 2012. Adherence was assessed using the Moriskscale and factors were assessed using a questionnaire addressing socioeconomic and personal characteristics, the disease, the use of immunomodulator and educational activities. The determination of the association was expressed in crude and adjusted odds ratio with a 95% confidence interval. Adherence rate was 46% and after the logistic regression model the adherence to immunomodulator treatment was positively associated with the following factors: age 18-38 years, time of diagnosis and treatment between 6 and 24 months, 0-3.5 score in the Expanded Disability Status Scale, perception of treatment benefits, intrinsic and extrinsic motivation, phone contact with the doctor and not missing the return visit. This study is important because it allowed to determine the association between factors and adherence to immunomodulator treatment in multiple sclerosis, contributing to prevention and control actions
Neutralizing antibody vaccine for pandemic and pre-emergent coronaviruses
Betacoronaviruses (betaCoVs) caused the severe acute respiratory syndrome (SARS) and Middle East Respiratory Syndrome (MERS) outbreaks, and the SARS-CoV-2 pandemic1–4. Vaccines that elicit protective immunity against SARS-CoV-2 and betaCoVs circulating in animals have the potential to prevent future betaCoV pandemics. Here, we show that macaque immunization with a multimeric SARS-CoV-2 receptor binding domain (RBD) nanoparticle adjuvanted with 3M-052/Alum elicited cross-neutralizing antibody (cross-nAb) responses against batCoVs, SARS-CoV-1, SARS-CoV-2, and SARS-CoV-2 variants B.1.1.7, P.1, and B.1.351. Nanoparticle vaccination resulted in a SARS-CoV-2 reciprocal geometric mean neutralization ID50 titer of 47,216, and protection against SARS-CoV-2 in macaque upper and lower respiratory tracts. Importantly, nucleoside-modified mRNA encoding a stabilized transmembrane spike or monomeric RBD also induced SARS-CoV-1 and batCoV cross-nAbs, albeit at lower titers. These results demonstrate current mRNA vaccines may provide some protection from future zoonotic betaCoV outbreaks, and provide a platform for further development of pan-betaCoV vaccines
Observation of Scaling Violations in Scaled Momentum Distributions at HERA
Charged particle production has been measured in deep inelastic scattering
(DIS) events over a large range of and using the ZEUS detector. The
evolution of the scaled momentum, , with in the range 10 to 1280
, has been investigated in the current fragmentation region of the Breit
frame. The results show clear evidence, in a single experiment, for scaling
violations in scaled momenta as a function of .Comment: 21 pages including 4 figures, to be published in Physics Letters B.
Two references adde
D* Production in Deep Inelastic Scattering at HERA
This paper presents measurements of D^{*\pm} production in deep inelastic
scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The
data have been taken with the ZEUS detector at HERA. The decay channel
(+ c.c.) has been used in the study. The
cross section for inclusive D^{*\pm} production with
and is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region
{ GeV and }. Differential cross
sections as functions of p_T(D^{*\pm}), and are
compared with next-to-leading order QCD calculations based on the photon-gluon
fusion production mechanism. After an extrapolation of the cross section to the
full kinematic region in p_T(D^{*\pm}) and (D^{*\pm}), the charm
contribution to the proton structure function is
determined for Bjorken between 2 10 and 5 10.Comment: 17 pages including 4 figure
Evidence for the strangeness-changing weak decay
Using a collision data sample corresponding to an integrated luminosity
of 3.0~fb, collected by the LHCb detector, we present the first search
for the strangeness-changing weak decay . No
hadron decay of this type has been seen before. A signal for this decay,
corresponding to a significance of 3.2 standard deviations, is reported. The
relative rate is measured to be
, where and
are the and fragmentation
fractions, and is the branching
fraction. Assuming is bounded between 0.1 and
0.3, the branching fraction would lie
in the range from to .Comment: 7 pages, 2 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm
Observation of hard scattering in photoproduction events with a large rapidity gap at HERA
Events with a large rapidity gap and total transverse energy greater than 5
GeV have been observed in quasi-real photoproduction at HERA with the ZEUS
detector. The distribution of these events as a function of the
centre of mass energy is consistent with diffractive scattering. For total
transverse energies above 12 GeV, the hadronic final states show predominantly
a two-jet structure with each jet having a transverse energy greater than 4
GeV. For the two-jet events, little energy flow is found outside the jets. This
observation is consistent with the hard scattering of a quasi-real photon with
a colourless object in the proton.Comment: 19 pages, latex, 4 figures appended as uuencoded fil
- …