335 research outputs found
Dyonic Integrable Models
A class of non abelian affine Toda models arising from the axial gauged
two-loop WZW model is presented. Their zero curvature representation is
constructed in terms of a graded Kac-Moody algebra. It is shown that the
discrete multivacua structure of the potential together with non abelian nature
of the zero grade subalgebra allows soliton solutions with non trivial electric
and topological charges.
The dressing transformation is employed to explicitly construct one and two
soliton solutions and their bound states in terms of the tau functions. A
discussion of the classical spectra of such solutions and the time delays are
given in detail.Comment: Latex 30 pages, corrected some typo
Geoquímica do granito, filões de quartzo com scheelite e águas da mina abandonada de Fonte Santa (NE de Portugal)
Os filões de quartzo com scheelite da mina da Fonte Santa atravessam a formação do Quartzito
Armoricano, do Ordovícico Inferior. A mineralização é de tipo “stockwork”, ocorre associada ao
leucogranito sin-F3, da Fonte Santa, que aflora a 250 m a Sul do jazigo e relaciona-se com a zona de
cisalhamento Moncorvo-Bemposta (Silva e Pereira, 2001). O leucogranito é de grão médio a fino,
moscovítico, com foliação N80ºW, subvertical. Possui quartzo, microclina, albite, moscovite, turmalina,
silimanite, zircão, apatite, e ilmenite. As amostras alteradas com microclinização e moscovitização
intensa contêm clorite, columbite-tantalite, volframite, ixiolite rica em W e óxidos de ferro. É um granito
peraluminoso, do tipo S, muito evoluído e estanífero com Sn > 44ppm (Silva, 2000). Alguns filões têm
quartzo parcialmente recristalizado, por vezes brechóide, impregnado de sulfuretos preenchendo
microfissuras e fracturas. A paragénese dos filões é constituída por quartzo, moscovite, clorite, turmalina,
scheelite, pirrotite, pirite, esfalerite, calcopirite, galena, óxidos de ferro, sulfatos de Fe e fosfatos de Pb,
Fe e Al. A mina da Fonte Santa foi explorada para W entre 1942 e 1982 (Triede, 2002). As águas
associadas à mina da Fonte Santa, são pouco mineralizadas, com condutividade específica < 150 μS/cm,
de tipo misto, bicarbonatadas ou sulfatadas. A maioria dos valores de pH (5.0 e 9.2) indicam que não há
uma drenagem ácida significativa na região, tal como encontrado noutros locais (e.g., Antunes et al.,
2002). Os valores mais ácidos (pH: 3.4-3.5) foram encontrados na lagoa da mina
T-duality of axial and vector dyonic integrable models
A general construction of affine Non Abelian (NA) - Toda models in terms of
axial and vector gauged two loop WZNW model is discussed. They represent {\it
integrable perturbations} of the conformal -models (with tachyons
included) describing (charged) black hole type string backgrounds. We study the
{\it off-critical} T-duality between certain families of axial and vector type
of integrable models for the case of affine NA- Toda theories with one global
U(1) symmetry. In particular we find the Lie algebraic condition defining a
subclass of {\it T-selfdual} torsionless NA Toda models and their zero
curvature representation.Comment: 20 pages, latex, no figures,improvments in the text of Sects.1,2 and
6;typos corrected,references added, to appear in Ann. of Physics (NY
Trust your guts? The effect of gut section on diet composition and impact of Mus musculus on islands using metabarcoding
Research Article1. DNA metabarcoding is widely used to characterize the diet of species, and it becomes
very relevant for biodiversity conservation, allowing the understanding
of trophic chains and the impact of invasive species. The need for cost-effective
biodiversity monitoring methods fostered advances in this technique. One question
that arises is which sample type provides a better diet representation.
2. Therefore, with this study, we intended to evaluate if there were differences
in diet estimates according to the section of the gastrointestinal tract analysed
and which section(s) provided the best diet representation. Additionally, we intended
to infer the ecological/economic impacts of an invader as a model of the
potential effects in an originally mammal-free
ecosystem.
3. We examined the gut contents of the house mouse Mus musculus introduced to
Cabo Verde, considering three sections: stomach, small intestine, and large intestine.
We applied a DNA-metabarcoding
approach using two genetic markers,
one specific for plants and another for invertebrates.
4. We showed that this invader consumed 131 taxa (73 plants and 58 invertebrates).
We obtained significant differences in the composition of two of the three sections,
with a higher incidence of invertebrates in the stomach and plants in the
intestines. This may be due to stomach inhibitors acting on plants and/or to faster
absorption of soft-body
invertebrates compared to the plant fibers in the intestines.
We verified that the impact of this invader in the ecosystem is predominantly
negative, as at least 50% of the ingested items were native, endemic, or
economically important taxa, and only 19% of the diet items were exotics 5. Overall, results showed the need to analyse only two gastrointestinal tract sections
to obtain robust diet data, increasing the cost-effectiveness
of the method.
Furthermore, by uncovering the native taxa most frequently preyed on by mice,
this DNA-metabarcoding
approach allowed us to evaluate efficiently which are
at the highest riskinfo:eu-repo/semantics/publishedVersio
Autologous chondrocyte implantation: series of 3 cases
A cartilagem hialina recobre as superfícies articulares e tem um papel importante na redução da fricção e da carga mecânica das articulações sinoviais, como o joelho. Este tecido não é suprido de vasos, nervos ou circulação linfática, o que pode ser uma das razões pela qual a cartilagem articular tem uma péssima capacidade de cicatrização. As lesões condrais, quando atingem o osso subcondral (lesão osteocondral), não cicatrizam e podem progredir para artrose com o passar do tempo. Em pacientes jovens, o tratamento dos defeitos condrais do joelho ainda é um desafio, principalmente as lesões maiores de 4cm. Uma das opções de tratamento nesses pacientes é o transplante autólogo de condrócitos, que por não violar o osso subcondral e por reparar o defeito com tecido semelhante à cartilagem hialina, teria a vantagem teórica de ser mais biológico e mecanicamente superior, quando comparado a outras técnicas. Descreveremos nesse artigo a experiência do Instituto de Ortopedia e Traumatologia do Hospital das Clínicas da Universidade de São Paulo (IOT-HCFMUSP) com o transplante autólogo de condrócitos (ACI), através do relato de três casos.Hyaline cartilage in the surface of synovial joints plays an important role in lowering stress and attrition in joints such as the knee. This tissue has no blood vessels, nerves, nor lymphatic drainage, which in part explains why articular cartilage has such poor capacity for healing. Chondral lesions reaching the subchondral bone (osteochondral lesions) do not heal and may progress to osteoarthritis as time passes. In young patients, treatment of such defects is challenging, especially in lesions larger than 4 cm. One option in young adults is the autologous chondrocyte implantation, capable of filling the defect with tissue similar to hyaline cartilage without violating the subchondral bone. Theoretically, it has biological and mechanical advantages over other surgical options. In this paper, we describe the experience with this procedure in a series of 3 cases at the Institute of Orthopedics and Traumatology, University of São Paulo
Quadro hematologico e peso do baço de camundongos com tumor de Ehrlich na forma sólida tratados com Agaricus blazei
Este trabalho teve como objetivo avaliar a utilização do Agaricus blazei nas formas de filtrado e suspensão total aquosa (10mg/animal) na terapêutica de camundongos portadores de tumor de Ehrlich sólido, testando sua atividade anti-neoplásica. Os animais tratados diariamente com A. blazei apresentaram valores maiores dos parâmetros hematológicos (eritrograma e leucograma), e peso relativo final do baço quando comparados com o grupo controle (água destilada), porém sem diferença significativa (P>0,05)
Electrically Charged Topological Solitons
Two new families of T-Dual integrable models of dyonic type are constructed.
They represent specific singular Non-Abelian Affine Toda models
having U(1) global symmetry. Their 1-soliton spectrum contains both neutral and
U(1) charged topological solitons sharing the main properties of 4-dimensional
Yang-Mills-Higgs monopoles and dyons. The semiclassical quantization of these
solutions as well as the exact counterterms and the coupling constant
renormalization are studied.Comment: 40 pages, latex, typos corrected in eq. (2.3), new section on spin of
solitons added, extended discussion on T-duality relation between axial and
vector topological theta terms in new subsection 2.
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