2,471 research outputs found
Diagnostic diagrams for ram-pressure stripped candidates
This paper presents a method for finding ram-pressure stripped (RPS) galaxy
candidates by performing a morphological analysis of galaxy images obtained
from the Legacy survey. We consider a sample of about 600 galaxies located in
different environments such as groups and clusters, tidally interacting pairs
and the field. The sample includes 160 RPS previously classified in the
literature into classes from J1 to J5, based on the increasing level of
disturbances. Our morphological analysis was done using the {\sc astromorphlib}
software followed by the inspection of diagnostic diagrams involving
combinations of different parameters like the asymmetry (), concentration
(), S\'ersic index (), and bulge strength parameters .
We found that some of those diagrams display a distinct region in which
galaxies classified as J3, J4 and J5 decouples from isolated galaxies. We call
this region as the morphological transition zone and we also found that tidally
interacting galaxies in pairs are predominant within this zone. Nevertheless,
after visually inspecting the objects in the morphological transition zone to
discard obvious contaminants, we ended up with 33 bonafide new RPS candidates
in the studied nearby groups and clusters (Hydra, Fornax, and CLoGS sample), of
which one-third show clear evidence of unwinding arms. Future works may
potentially further increase significantly the samples of known RPS using such
method.Comment: 17 pages, 9 figure
Multiple D4-D2-D0 on the Conifold and Wall-crossing with the Flop
We study the wall-crossing phenomena of D4-D2-D0 bound states with two units
of D4-brane charge on the resolved conifold. We identify the walls of marginal
stability and evaluate the discrete changes of the BPS indices by using the
Kontsevich-Soibelman wall-crossing formula. In particular, we find that the
field theories on D4-branes in two large radius limits are properly connected
by the wall-crossings involving the flop transition of the conifold. We also
find that in one of the large radius limits there are stable bound states of
two D4-D2-D0 fragments.Comment: 24 pages, 4 figures; v2: typos corrected, minor changes, a reference
adde
A amplitude de distribuição dos glóbulos vermelhos (rdw) pode ser considerado como um marcador da atividade da doença de Crohn?
Introduction: Recently, it has been suggested an association between red cell distribution width
(RDW) and Crohn’s disease activity index (CDAI), but its use is not yet performed in daily clinical
practice.
Objectives: To determine whether RDW can be used as a marker of Crohn’s disease (CD) activity.
Methods: This was a cross-sectional study including patients with CD, observed consecutively
in an outpatient setting between January 1st and September 30th 2013. Blood cell indices,
erythrocyte sedimentation rate (ESR), and C-reactive protein were measured. CD activity was
determined by CDAI (active disease if CDAI ≥ 150). Associations were analyzed using logistic
regression (SPSS version 20).
Results: 119 patients (56% female) were included in the study with a mean age of 47 years
(SD 15.2). Twenty patients (17%) had active disease. The median RDW was 14.0 (13---15). There
was an association between RDW and disease activity (p = 0.044). After adjustment for age and
gender, this association remained consistent (OR 1.20, 95% CI 1.03---1.39, p = 0.016). It was also
found that the association between RDW and disease activity was independent of hemoglobin
and ESR (OR 1.36, 95% CI 1.08---1.72, p = 0.01) and of biologic therapy (OR 1.19, 95% CI 1.03---1.37,
p = 0.017). A RDW cutoff of 16% had a specificity and negative predictive value for CDAI ≥ 150
of 88% and 86%, respectively.
Conclusion: In this study, RDW proved to be an independent and relatively specific marker of
CD activity. These results may contribute to the implementation of this simple parameter, in
clinical practice, aiming to help therapeutic decisions.Introduc¸ão: Recentemente, tem vindo a ser sugerida uma associac¸ão entre o valor de RDW e
a atividade da doença de Crohn (DC), mas a sua utilização não está ainda implementada na
prática clínica diária.
Objetivos: Determinar se o RDW pode ser utilizado como marcador de atividade da DC.
Métodos: Estudo transversal, em doentes com DC, observados consecutivamente em consulta
de Doença Inflamatória Intestinal, entre 1 de janeiro e 30 de setembro de 2013. Analisaram-se
índices do hemograma, proteína C reativa e velocidade de sedimentação. A gravidade da doença
foi avaliada pelo Crohn’s disease activity index (doença ativa se CDAI≥150). As associações
foram estudadas usando a regressão logística (SPSS Statistics V20).
Resultados: Incluídos 119 doentes (56% do sexo feminino), com idade média de 47 anos (DP 15,2
anos). Vinte doentes (17%) tinham doença ativa. O valor do RDW mediano foi 14,0% (13-15).
Verificou-se uma associação entre RDW e atividade da doença (p = 0,044). Após ajuste para a
idade e o sexo, esta associação manteve-se consistente (OR 1,20; 95% CI 1,03-1,39; p = 0,016).
Verificou-se ainda que a associação do valor do RDW com a atividade da doença foi independente
do valor da hemoglobina e da velocidade de sedimentação (OR 1,36; 95% CI 1,08-1,72; p = 0,01)
e da terapêutica biológica (OR 1,19; 95% CI 1,03-1,37; p = 0,017). Para um valor de corte de
RDW de 16%, a especificidade e o valor preditivo negativo de CDAI≥ 150 foram de 88% e 86%,
respetivamente.
Conclusão: Neste estudo, o valor do RDW demonstrou ser um marcador independente e relativamente
específico da atividade da doenc¸a de Crohn. Estes resultados poderão contribuir
para a aplicação deste parâmetro simples, na prática clinica diária, visando auxiliar decisões
terapêuticas
Wall-crossing of D4-D2-D0 and flop of the conifold
We discuss the wall-crossing of the BPS bound states of a non-compact
holomorphic D4-brane with D2 and D0-branes on the conifold. We use the
Kontsevich-Soibelman wall-crossing formula and analyze the BPS degeneracy in
various chambers. In particular we obtain a relation between BPS degeneracies
in two limiting attractor chambers related by a flop transition. Our result is
consistent with known results and predicts BPS degeneracies in all chambers.Comment: 15 pages, 4 figures; v2: typos corrected; v3: minor changes, a
reference added, version to be published in JHE
Collagen-Based Films Containing Liposome-Loaded Usnic Acid as Dressing for Dermal Burn Healing
The aim of this study was assess the effect of collagen-based
films containing usnic acid as a wound dressing for dermal burn
healing. Second-degree burn wounds were performed in forty-five
Wistar rats, assigned into nine groups: COL—animals treated
with collagen-based films; PHO—animals treated with collagen
films containing empty liposomes; UAL—animals treated with
collagen-based films containing usnic acid incorporated into
liposomes. After 7, 14, and 21 days the animals were euthanized.
On 7th day there was a moderate infiltration of neutrophils, in
UAL, distributed throughout the burn wounds, whereas in COL and
PHO, the severity of the reaction was slighter and still limited
to the margins of the burn wounds. On the 14th day, the
inflammatory reaction was less intense in UAL, with remarkable
plasma cells infiltration. On the 21st day, there was reduction of
the inflammation, which was predominantly composed of plasma cells
in all groups, particularly in UAL. The use of the usnic acid
provided more rapid substitution of type-III for type-I collagen
on the 14th day, and improved the collagenization density on the
21st day. It was concluded that the use of reconstituted bovine
type-I collagen-based films containing usnic acid improved burn
healing process in rats
Super Weyl invariance: BPS equations from heterotic worldsheets
It is well-known that the beta functions on a string worldsheet correspond to
the target space equations of motion, e.g. the Einstein equations. We show that
the BPS equations, i.e. the conditions of vanishing supersymmetry variations of
the space-time fermions, can be directly derived from the worldsheet. To this
end we consider the RNS-formulation of the heterotic string with (2,0)
supersymmetry, which describes a complex torsion target space that supports a
holomorphic vector bundle. After a detailed account of its quantization and
renormalization, we establish that the cancellation of the Weyl anomaly
combined with (2,0) finiteness implies the heterotic BPS conditions: At the one
loop level the geometry is required to be conformally balanced and the gauge
background has to satisfy the Hermitean Yang-Mills equations.Comment: 1+31 pages LaTeX, 5 figures; final version, discussion relation Weyl
invariance and (2,0) finiteness extended, typos correcte
Negative discriminant states in N=4 supersymmetric string theories
Single centered BPS black hole solutions exist only when the charge carried
by the black hole has positive discriminant. On the other hand the exact dyon
spectrum in heterotic string theory compactified on T^6 is known to contain
states with negative discriminant. We show that all of these negative
discriminant states can be accounted for as two centered black holes. Thus
after the contribution to the index from the two centered black holes is
subtracted from the total microscopic index, the index for states with negative
discriminant vanishes even for finite values of charges, in agreement with the
results from the black hole side. Bound state metamorphosis -- which requires
us to identify certain apparently different two centered configurations
according to a specific set of rules -- plays a crucial role in this analysis.
We also generalize these results to a class of CHL string theories.Comment: LaTeX file, 32 pages; v2: reference added; v3: added new section 3.
A New Class of Four-Dimensional N=1 Supergravity with Non-minimal Derivative Couplings
In the N=1 four-dimensional new-minimal supergravity framework, we
supersymmetrise the coupling of the scalar kinetic term to the Einstein tensor.
This coupling, although introduces a non-minimal derivative interaction of
curvature to matter, it does not introduce harmful higher-derivatives. For this
construction, we employ off-shell chiral and real linear multiplets. Physical
scalars are accommodated in the chiral multiplet whereas curvature resides in a
linear one.Comment: 18 pages, version published at JHE
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