3,635 research outputs found
Contribuição para o controlo da infeção nosocomial de Candida parapsilosis por tipagem com marcadores de DNA microssatélite
Fungal infections constitute a relevant problem in hospitals from all over the world. Their easy
transmission through the air, water, or by direct or indirect contact with contaminated persons,
surfaces or objects lead to an increasing preoccupation with those infections, particularly in
immunocompromised patients.
Regarding the enormous importance of Candida parapsilosis as agent of bloodstream infections
and hospital outbreaks, the presented work aimed to contribute to the development of new
molecular tools able to answer to epidemiological questions related with infections by this species
and their application in favor of patient safetyAs infecções fúngicas constituem um problema hospitalar relevante em todo o mundo. A fácil
transmissão dos fungos pelo ar, água ou pelo contato direto ou indireto com pessoas, superfícies
ou objetos contaminados conduz a uma crescente preocupação com este tipo de infecções,
principalmente em pacientes imunocomprometidos.
Considerando a grande relevância da levedura Candida parapsilosis em Portugal como agente
etiológico de infecções sistémicas e de surtos hospitalares, o trabalho apresentado teve como
objetivo contribuir para o desenvolvimento de novas ferramentas moleculares que permitissem
responder a questões epidemiológicas relacionadas com esta espécie e posterior aplicação desta
ferramenta em prol da segurança do paciente
Acute myocardial infarction in the puerperium. A case report
Acute myocardial infarction is a rare event in the puerperium that can have life-threatening consequences if not diagnosed early. Spontaneous coronary artery dissection is the most frequent causative mechanism in the period immediately after labor. This article reports the case of a 38-year-old woman with acute myocardial infarction due to spontaneous coronary artery dissection on the 7th day after delivery. The authors review this entity and also discuss the prognosis and future management of this patient
The Concept of Culture in Critical Mathematics Education
© Springer International Publishing AG, part of Springer Nature 2018. This is a post-peer-review, pre-copyedit version of a chapter published in The Philosophy of Mathematics Education Today. The final authenticated version is available online at: http://dx.doi.org/10.1007/978-3-319-77760-3A well-known critique in the research literature of critical mathematics education suggests that framing educational questions in cultural terms can encourage ethnic-cultural essentialism, obscure conflicts within cultures and promote an ethnographic or anthropological stance towards learners. Nevertheless, we believe that some of the obstacles to learning mathematics are cultural. ‘Stereotype threat’, for example, has a basis in culture. Consequently, the aims of critical mathematics education cannot be seriously pursued without including a cultural approach in educational research. We argue that an adequate conception of culture is available and should include normative/descriptive and material/ideal dyads as dialectical moments
O humor em movimentos sociais: criatividade e informalidade nas manifestações anti-austeridade em Portugal
Esta investigação discute o papel do humor movimentos em Portugal, nomeadamente entre 2011 e 2013. Foi utilizada a Análise Crítica do Discurso para analisar cartazes de uma manifestação do Que se Lixe a Troika (QSLT) e de outra organizada pelos sindicatos, tendo-se realizado entrevistas a activistas e sindicalistas. Confirmando-se a utilização profícua de humor e criatividade no protesto do QSLT, conclui-se que se deve a um menor grau de institucionalismo, à identidade de resistência, à cultura de protesto, e à preocupação dos activistas em recriar a comunicação. São também discutidas as vantagens/desvantagens do humor na divulgação de um problema social.info:eu-repo/semantics/publishedVersio
Hamiltonian Formalism for Space-time Non-commutative Theories
Space-time non-commutative theories are non-local in time. We develop the
Hamiltonian formalism for non-local field theories in d space-time dimensions
by considering auxiliary d+1 dimensional field theories which are local with
respect to the evolution time. The Hamiltonian path integral quantization is
considered and the Feynman rules in the Lagrangian formalism are derived. The
case of non-commutative \phi^3 theory is considered as an example.Comment: 6 pages, A new section is added with other comments and references.
To appear in PR
Polyion Adsorption onto Catanionic Surfaces. A Monte Carlo Study
The adsorption of a single and negatively charged polyion with varying flexibility onto a surface carrying both negative and positive charges representing a charged membrane surface has been investigated by using a simple model employing Monte Carlo simulations. The polyion was represented by a sequence of negatively charged hard spheres connected with harmonic bonds. The charged surface groups were also represented by charged hard spheres, and they were positioned on a hard surface slightly protruding into the solution. The surface charges were either frozen in a liquidlike structure or laterally mobile. With a large excess of positive surface charges, the classical picture of a strongly adsorbed polyion with an extended and flat configuration emerged. However, adsorption also appeared at a net neutral surface or at a weakly negatively charged surface, and at these conditions the adsorption was stronger with a flexible polyion as compared to a semiflexible one, two features not appearing in simpler models containing homogeneously charged surfaces. The presence of charged surface patches (frozen surface charges) and the ability of polarization of the surface charges (mobile surface charges) are the main reasons for the enhanced adsorption. The stronger adsorption with the flexible chain is caused by its greater ability to spatially correlate with the surface charges
A ZZ Ceti white dwarf in SDSS J133941.11+484727.5
We present time-resolved spectroscopy and photometry of the cataclysmic
variable (CV) SDSSJ133941.11+484727.5 (SDSS1339) which has been discovered in
the Sloan Digital Sky Survey Data Release 4. The orbital period determined from
radial velocity studies is 82.524(24)min, close to the observed period minimum.
The optical spectrum of SDSS1339 is dominated to 90% by emission from the white
dwarf. The spectrum can be successfully reproduced by a three-component model
(white dwarf, disc, secondary) with Twd=12500K for a fixed log g=8.0, d=170pc,
and a spectral type of the secondary later than M8. The mass transfer rate
corresponding to the optical luminosity of the accretion disc is very
low,~1.7x10^-13Msun/yr. Optical photometry reveals a coherent variability at
641s with an amplitude of 0.025mag, which we interpret as non-radial pulsations
of the white dwarf. In addition, a long-period photometric variation with a
period of either 320min or 344min and an amplitude of 0.025mag is detected,
which bears no apparent relation with the orbital period of the system. Similar
long-period photometric signals have been found in the CVs
SDSSJ123813.73-033933.0, SDSSJ204817.85-061044.8, GW Lib and FS Aur, but so far
no working model for this behaviour is available.Comment: MNRAS, in press, 8 pages, 10 figures, some figures downgraded to meet
the file size constraint of arxiv.or
Discrete Symmetries and Localization in a Brane-world
Discrete symmetries are studied in warped space-times with one extra
dimension. In particular, we analyze the compatibility of five- and
four-dimensional charge conjugation, parity, time reversal and the orbifold
symmetry Z_2 with localization of fermions on the four-dimensional brane-world
and Lorentz invariance. We then show that, when a suitable topological scalar
field (the ``kink'') is included, fermion localization is a consequence of
(five-dimensional) CPT invariance.Comment: REVTeX, 8 pages, 1 EPS figure include
Dois exemplos de tectónica pós-rifting da Bacia Lusitaniana
A Cadeia da Arrábida é a estrutura morfotectónica orogénica, constituída por empilhamentos de cavalgamentos, mais ocidental de todo o orógeno alpino da área emersa da placa litosférica Eurásia. Atentando apenas nos relevos orogénicos alpinos da área emersa de Portugal, as suas estruturas e morfologia tornam-na no mais elegante exemplo de tectónica orogénica alpina em Portugal.
A Serra de Sintra constitui um relevo associado à intrusão do Complexo Ígneo de Sintra de idade neo-cretácica e ao cavalgamento frontal de idade cenozóica, com vergência para Norte que se estende desde as proximidades do rio Tejo, passando pela base da vertente norte da Serra de Sintra, continuando mar adentro.
Olhando para a continuação imersa da Margem Continental Portuguesa vê-se que estes relevos não estão isolados, mas antes fazem parte dum grupo de três outras estruturas compressivas que acomodaram o encurtamento orogénico resultante da colisão África-Eurásia ocidentais no segmento sudoeste ibérico, o Banco do Gorringe, os Montes de Avis e o Planalto de Marquês de Pombal. Todas estas estruturas se constituem como estruturas anticlinais, mais ou menos simples, a tecto dum cavalgamento com transporte para noroeste ou oeste-noroeste. Na face meridional de Portugal, mais próxima do limite de placas, as estruturas de deformação compressiva resultantes da orogenia alpina encontram-se representadas na Bacia do Algarve e, mais a sul, pelo Banco do Guadalquivir.
Todas estas estruturas se formaram no âmbito da orogenia alpina, consequência dum contexto cinemático de aproximação das placas litosféricas Eurásia e África, cujas manifestações morfotectónicas e sedimentares se começaram a manifestar no Cretácico Superior após o Cenomaniano. A distribuição espacio-temporal da deformação orogénica no segmento mais ocidental do orógeno é heterogénea e extremamente complexa. Por exemplo, em Portugal – segmento autóctone do orógeno alpino - as principais estruturas compressivas alpinas mais antigas datam do Cretácico superior e na região de Lisboa-Sintra de idade paleogénica. Contudo as estruturas de maior envergadura morfológica são de idade miocénica (serra da Arrábida, Banco do Gorringe, Montes de Avis) e mesmo de reactivação mais recente (Falha e planalto do Marquês de Pombal, Falha da Ferradura e Banco de Guadalquivir.
A mesma heterogeneidade espacio-temporal se verifica em segmentos alóctones como no orógeno Bético-Rifenho, cujo arco orogénico frontal se vem propagando para oeste desde o Cretácico superior, simultaneamente cavalgando para norte e para sul, as margens continentais do sul de Espanha e norte de África. Esta migração orogénica está simultaneamente associada a colapso orogénico e distensão nas áreas internas do orógeno (Mar de Alborán), o que tem constituído um dos paradoxos da deformação orogénica alpina mais desafiantes das últimas décadas e para cuja solução se têm proposto mecanismos de delaminação tectónica da base da litosfera ou retro-rolamento da placa subductada
The Decay in the Context of Chiral Perturbation Theory
We study the decay , using
chiral perturbation theory for heavy charmed mesons
and vector mesons, in the kinematic regime where (here or ) is much smaller than the chiral symmetry breaking
scale, ( 1 GeV). We present the
leading diagrams and amplitude, and calculate the rate, in the region where, to
leading order in our calculations, the is at zero recoil in the
rest frame. The rate thus calculated is given in terms of a known form
factor and depends on the coupling constant of the heavy
(charmed) meson chiral perturbation theory Lagrangian. A measurement of the
above decay, in the aforementioned kinematic regime, can result in the
extraction of an experimental value for , accurate at the level of our
approximations, and give us a measure of the validity of approaches based on
chiral perturbation theory in studying similar processes.Comment: 17 pages, Latex, 2 embedded postscript figure
- …