901 research outputs found
Right circumcaval ureter and double right renal vein in the Brazilian shorthair cat (Felis catus): two case reports
Variations of the renal veins are well described in the literature, although variations concerning the ureter are considered a rare finding in cats. The circumcaval ureter is one of the rarest variations of the ureter and is characterised by a loop of the ureter posterior to the caudal vena cava. This variant is also known as preureteral vena cava and retrocaval ureter. It is thought to be caused by a deviation during embryonic development of the aforementioned vein. Due to its rarity, there are scarce reports of the circumcaval ureter in cats, and its association with two renal veins makes it less common as well. These variations should be preoperatively identified in order to avoid complications in kidney transplants, ureteral surgeries and cystoscopies, for instance. The present work aims to report two cases of a circumcaval ureter with two renal veins in two different Brazilian shorthair cats (Felis catus)
The QCD critical end point in the SU(3) Nambu--Jona-Lasinio model
We study the chiral phase transition at finite temperature and baryonic
chemical potential within the framework of the SU(3) Nambu-Jona-Lasinio
(NJL) model. The QCD critical end point (CEP) and the critical line at finite
and are investigated: the study of physical quantities, such as the
baryon number susceptibility and the specific heat in the vicinity the CEP,
will provide relevant information concerning the order of the phase transition.
The class of the CEP is determined by calculating the critical exponents of
those quantities.Comment: 10 pages, 4 figures; PLB versio
Effect of an inhomogeneous external magnetic field on a quantum dot quantum computer
We calculate the effect of an inhomogeneous magnetic field, which is
invariably present in an experimental environment, on the exchange energy of a
double quantum dot artificial molecule, projected to be used as a 2-qubit
quantum gate in the proposed quantum dot quantum computer. We use two different
theoretical methods to calculate the Hilbert space structure in the presence of
the inhomogeneous field: the Heitler-London method which is carried out
analytically and the molecular orbital method which is done computationally.
Within these approximations we show that the exchange energy J changes slowly
when the coupled dots are subject to a magnetic field with a wide range of
inhomogeneity, suggesting swap operations can be performed in such an
environment as long as quantum error correction is applied to account for the
Zeeman term. We also point out the quantum interference nature of this slow
variation in exchange.Comment: 12 pages, 4 figures embedded in tex
Radiocarbon geochronology of the sediments of the São Paulo Bight (southern Brazilian upper margin)
The aim of this work was to generate an inventory of the data on radiocarbon datings obtained from sediments of the São Paulo Bight (southern Brazilian upper margin) and to analyze the data in terms of Late Quaternary sedimentary processes and sedimentation rates. A total of 238 radiocarbon datings from materials collected using differents ampling procedures was considered for this work. The sedimentation rates varied from less than 2 to 68 cm.kyr-1. The highest sedimentation rate values were found in a low-energy (rÃa type) coastal system as well as in the upwelling zones of Santa Catarina and Cabo Frio. The lowest rates were found on the outer shelf and upper slopes. Our results confirm the strong dependency of the shelf currents, with an emphasis to the terrigenous input from the RÃo de La Plata outflow which is transported via the Brazilian Coastal Current, as well as of the coupled Brazil Current - Intermediate Western Boundary Current (BC-IWBC) dynamics on the sedimentary processes. At least three indicators ofthe paleo sea level were found at 12200 yr BP (conventional radiocarbon age) (103 meters below sea level - mbsl),8300-8800 cal yr BP (13 mbsl) and 7700-8100 cal yr BP (6 mbsl).O objetivo deste trabalho foi a geração de um inventário dos dados de datação de radiocarbono obtidos de sedimentos do Embaiamento de São Paulo (Margem Continental Superior do Sul do Brasil) e analisar os dados em termos de processos sedimentares quaternários e taxas de sedimentação. Um total de238 datações ao radiocarbono de materiais coletados com autilização de procedimentos amostrais diferentes foi considerado neste trabalho. As taxas de sedimentação variaram de menor que 2 a 68 cm.kyr-1. As taxas de sedimentação mais altas foram encontradas em um sistema costeiro de baixa energia (tipo rÃa), bem como nas zonas de ressurgência de Santa Catarina e Cabo Frio. As taxas mais baixas foram encontradas na plataforma externa e talude superior. Nossos resultados confirmam a forte dependência do sistema de correntes de plataforma, com ênfase no aporte terrÃgeno oriundo do Rio daPrata, transportado através da Corrente Costeira do Brasil, e da dinâmica da Corrente do Brasil - Corrente de Contorno Intermediária (CB-CCI) nos processos sedimentares. Pelo menostrês indicadores de paleo-nÃveis marinhos foram encontrados a 12200 anos AP (idade radiocarbônica convencional) (103 metros abaixo do nÃvel do mar atual - manm), 8300-8800 cal anos AP (13 manm) e 7700-8100 cal anos BP (6 manm).Fundação de Amparo à Pesquisado Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq
Classical and Quantum Strings in compactified pp-waves and Godel type Universes
We consider Neveu-Schwarz pp-waves with spacetime supersymmetry. Upon
compactification of a spacelike direction, these backgrounds develop Closed
Null Curves (CNCs) and Closed Timelike Curves (CTCs), and are U-dual to
supersymmetric Godel type universes. We study classical and quantum strings in
this background, with emphasis on the strings winding around the compact
direction. We consider two types of strings: long strings stabilized by NS flux
and rotating strings which are stabilized against collapse by angular momentum.
Some of the latter strings wrap around CNCs and CTCs, and are thus a potential
source of pathology. We analyze the partition function, and in particular
discuss the effects of these string states. Although our results are not
conclusive, the partition function seems to be dramatically altered due to the
presence of CNCs and CTCs. We discuss some interpretations of our results,
including a possible sign of unitary violation.Comment: 42 pages, LaTeX, 2 figure
Semiclassical Quantization for the Spherically Symmetric Systems under an Aharonov-Bohm magnetic flux
The semiclassical quantization rule is derived for a system with a
spherically symmetric potential and an
Aharonov-Bohm magnetic flux. Numerical results are presented and compared with
known results for models with . It is shown that the
results provided by our method are in good agreement with previous results. One
expects that the semiclassical quantization rule shown in this paper will
provide a good approximation for all principle quantum number even the rule is
derived in the large principal quantum number limit . We also discuss
the power parameter dependence of the energy spectra pattern in this
paper.Comment: 13 pages, 4 figures, some typos correcte
House dust fungal communities’ characterization: a double take on the six by sixty by six (6 × 60 × 6) project
Fungi are a group of microbes that are found with
particular incidence in the indoor environment. Their direct
toxicity or capability of generating toxic compounds
has been associated with a large number of adverse health
effects, such as infectious diseases and allergies. Given
that in modern society people spend a large part of their
time indoors; fungal communities’ characterization of this
environmental compartment assumes paramount importance
in the comprehension of health effects. House dustThis work was supported by European Funds through
COMPETE and by National Funds through the Portuguese
Science Foundation (FCT) within project PEstOE/SAU/UI0709/2014.
Ana C. A. Sousa and Sónia D. Coelho
acknowledge FCT for the grants SFRH/BPD/65884/2009
and SFRH/
BD/78168/2011 (supported by funding from the Human
Potential Operational Programme POPH, inscribed in
the National Strategic Reference Framework and partially
subsidized by the European Social Fund).info:eu-repo/semantics/publishedVersio
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