170 research outputs found
Quantum structure of T-dualized models with symmetry breaking
We study the principal sigma-models defined on any group manifold GL x GR/GD
with breaking of GR, and their T-dual transforms. For abritary breaking we can
express the torsion and Ricci tensor of the dual model in terms of the frame
geometry of the initial principal model. Using these results, we give necessary
and sufficient conditions for the dual model to be torsionless and prove that
the one-loop renormalizability of a given principal model is inherited by its
dual partner, who shares the same beta-functions. These results are shown to
hold also if the principal model is endowed with torsion. As an application we
compute the beta-functions for the full Bianchi family and show that for some
choices of the breaking parameters the dilaton anomaly is absent: for these
choices the dual torsion vanishes. For the dualized Bianchi V model (which is
torsionless for any breaking), we take advantage of its simpler structure, to
study its two-loops renormalizability.Comment: 24 pages, no figures, latex2
Poisson-Lie Duality in the String Effective Action
The symmetry properties of the bosonic string effective action under
Poisson-Lie duality transformations are investigated. A convenient and simple
formulation of these duality transformations is found, that allows the
reduction of the string effective action in a Kaluza-Klein framework. It is
shown that the action is invariant provided that the two Lie algebras, forming
the Drinfeld double, have traceless structure constants. Finally, a functional
relation is found between the Weyl anomaly coefficients of the original and
dual non-linear sigma models.Comment: 26 pages, LaTe
Long-lived stops in MSSM scenarios with a neutralino LSP
This work investigates the possibility of a long-lived stop squark in
supersymmetric models with the neutralino as the lightest supersymmetric
particle (LSP). We study the implications of meta-stable stops on the sparticle
mass spectra and the dark matter density. We find that in order to obtain a
sufficiently long stop lifetime so as to be observable as a stable R-hadron at
an LHC experiment, we need to fine tune the mass degeneracy between the stop
and the LSP considerably. This increases the stop-neutralino coanihilation
cross section, leaving the neutralino relic density lower than what is expected
from the WMAP results for stop masses ~1.5 TeV/c^2. However, if such scenarios
are realised in nature we demonstrate that the long-lived stops will be
produced at the LHC and that stop-based R-hadrons with masses up to 1 TeV/c^2
can be detected after one year of running at design luminosity
Quantum equivalence of sigma models related by non Abelian Duality Transformations
Coupling constant renormalization is investigated in 2 dimensional sigma
models related by non Abelian duality transformations. In this respect it is
shown that in the one loop order of perturbation theory the duals of a one
parameter family of models, interpolating between the SU(2) principal model and
the O(3) sigma model, exhibit the same behaviour as the original models. For
the O(3) model also the two loop equivalence is investigated, and is found to
be broken just like in the already known example of the principal model.Comment: As a result of the collaboration of new authors the previously
overlooked gauge contribution is inserted into eq.(43) changing not so much
the formulae as part of the conclusion: for the models considered non Abelian
duality is OK in one loo
Clinical case report of Hepatozoon canis in the city of Cali
El Hepatozoon canis es un protozoario que parasita los leucocitos de los caninos, su
huésped definitivo es la garrapata común (Riphicephalus sanguineus) y el perro es el
huésped intermediario, el cual adquiere la infección al ingerir una garrapata infectada
con el parásito, este continúa su multiplicación y diseminación en el perro ocasionando
sintomatología y daños multisistémicos en el organismo (1).
La hepatozoonosis canina es una enfermedad poco estudiada y confundida a nivel
mundial con otras enfermedades transmitidas por garrapatas como lo son la
Babesiosis y la Ehrlichiosis al presentar cuadros clínicos similares en los pacientes.
En el reporte de este caso se evidenció un cuadro clínico poco especíifico con la
enfermedad la cuál fue confirmada mediante frotis sanguíneo y observación
microscópica al ser una de las formas más adecuadas para la diferenciación del
parásito por su morfología específica. Los pacientes con Hepatozoon canis pueden
ser asintomáticos o presentar variación en su sintomatología (2).
Los pocos reportes a nivel mundial sobre el Hepatozoon canis llevan a un
desconocimiento de clínicos y propietarios los cuales descartan la enfermedad y
relacionan su sintomatología con otras enfermedades logrando así la no identificación
de este protozoo, un mal abordaje y la no resolución del problema. Por esta razón la
importancia de reportar y describir este caso clínico, para elaborar guías de abordaje
clínico basados en la evidencia, los cuales sean de fácil acceso para los médicos
veterinarios (3Hepatozoon canis is a protozoan that parasitizes canine leukocytes, its definitive host
is the common tick (Riphicephalus sanguineus) and the dog is the intermediate host,
which acquires the infection by ingesting a tick infected with the parasite, it continues
its multiplication and dissemination in the dog causing symptoms and multisystemic
damage in the body.
Canine hepatozoonosis is a disease little studied and confused worldwide with other
diseases transmitted by ticks such as Babesiosis and Ehrlichiosis, as it presents similar
clinical pictures in patients. In the report of this case, nonspecific clinical picture with
the desease was evidenced which was confirmed by blood smear and microscopic
observation as it is one of the most appropriate ways for the differentiation of the
parasite due to its specific morphology, patients with Hepatozoon canis can be
asymptomatic or present variation in their symptoms.
The few reports worldwide on Hepatozoon canis lead to a lack of knowledge of
clinicians and owners who rule out the disease and relate its symptoms to other
diseases, thus achieving a poor approach and nonresolution of the problem. For this
reason, the importance of reporting and describing this clinical case, to develop
evidence- based medical approach guides which are easily accessible to veterinarians.PregradoMédico(a) Veterinario(a) y Zootecnist
Genomic mapping of splicing-related genes identify amplifications in lsm1, clns1a, and ilf2 in luminal breast cancer
© 2021 by the authors.Alternative splicing is an essential biological process, which increases the diversity and complexity of the human transcriptome. In our study, 304 splicing pathway-related genes were evaluated in tumors from breast cancer patients (TCGA dataset). A high number of alterations were detected, including mutations and copy number alterations (CNAs), although mutations were less frequently present compared with CNAs. In the four molecular subtypes, 14 common splice genes showed high level amplification in >5% of patients. Certain genes were only amplified in specific breast cancer subtypes. Most altered genes in each molecular subtype clustered to a few chromosomal regions. In the Luminal subtype, amplifications of LSM1, CLNS1A, and ILF2 showed a strong significant association with prognosis. An even more robust association with OS and RFS was observed when expression of these three genes was combined. Inhibition of LSM1, CLNS1A, and ILF2, using siRNA in MCF7 and T47D cells, showed a decrease in cell proliferation. The mRNA expression of these genes was reduced by treatment with BET inhibitors, a family of epigenetic modulators. We map the presence of splicing-related genes in breast cancer, describing three novel genes, LSM1, CLNS1A, and ILF2, that have an oncogenic role and can be modulated with BET inhibitors.A.O.’s lab is supported by the Instituto de Salud Carlos III (ISCIII, PI19/00808); ACEPAIN; CRIS Cancer Foundation and Diputación de Albacete. This research is also supported by PI18/01020 from the Instituto de Salud Carlos III and co-financed by the European Development Regional Fund (FEDER) “A way to achieve Europe” (ERDF); N.L. MDM was supported by the Spanish Ministry of Education (FPU grant; Ref.: FPU18/01319). B.G. was financed by the 2018-2.1.17-TETKR-00001, 2020-1.1.6-JÖVO-2021-00013, and 2018-1.3.1-VKE-2018-00032 grants and by the Higher ˝ Education Institutional Excellence Programme (2020-4.1.1.-TKP2020) of the Ministry for Innovation and Technology in Hungary
Les Houches 2011: Physics at TeV Colliders New Physics Working Group Report
We present the activities of the "New Physics" working group for the "Physics
at TeV Colliders" workshop (Les Houches, France, 30 May-17 June, 2011). Our
report includes new agreements on formats for interfaces between computational
tools, new tool developments, important signatures for searches at the LHC,
recommendations for presentation of LHC search results, as well as additional
phenomenological studies.Comment: 243 pages, report of the Les Houches 2011 New Physics Group; fix
three figure
Cardiac effects of acute exhaustive exercise in a rat model
AbstractBackgroundThe role of physical exercise in the prevention and treatment of cardiovascular diseases has been well described, however, elevations in cardionecrotic biomarkers after prolonged exercise (i.e. ultramarathon running) were observed. We aimed at understanding the biochemical, molecular biological, structural and functional alterations in the heart after exhaustive exercise in a rat model.MethodsRats of the exercise group were forced to swim for 3h with 5% body weight (workload) attached to the tail, control rats were taken into the water for 5min. After a 2-hour recovery period we performed left ventricular (LV) pressure-volume analysis to investigate LV function and mechanoenergetics. Additionally, blood and myocardium samples were harvested for biochemical and histological examinations. Gene expression changes were detected by qRT-PCR.ResultsWhen compared to controls, elevated plasma levels of cardiac troponin T and creatine kinase were detected after exhaustive exercise. Histological analysis showed sporadic fragmentation of myocardial structure and leukocyte infiltration in the exercised group. We observed increased end-systolic volume, decreased ejection fraction, impaired contractility (preload recruitable stroke work) and mechanoenergetics (ventriculoarterial coupling, mechanical efficiency) of LV after exercise. Myocardial expression of major antioxidant enzymes was increased along with increased myocardial nitro-oxidative stress. Bax/Bcl-2 ratio and TUNEL staining showed enhanced apoptotic signaling. Exhaustive exercise also resulted in the dysregulation of the matrix metalloproteinase system.ConclusionsExcessive physical activity has an adverse effect on the heart. The observed functional impairment is associated with increased nitro-oxidative stress, enhanced apoptotic signaling and dysregulation of the matrix metalloproteinase system after exhaustive exercise
Possible extracardiac predictors of aortic dissection in Marfan syndrome
BACKGROUND: According to previous studies, aortic diameter alone seems to be insufficient to predict the event of aortic dissection in Marfan syndrome (MFS). Determining the optimal schedule for preventive aortic root replacement (ARR) aortic growth rate is of importance, as well as family history, however, none of them appear to be decisive. Thus, the aim of this study was to search for potential predictors of aortic dissection in MFS. METHODS: A Marfan Biobank consisting of 79 MFS patients was established. Thirty-nine MFS patients who underwent ARR were assigned into three groups based on the indication for surgery (dissection, annuloaortic ectasia and prophylactic surgery). The prophylactic surgery group was excluded from the study. Transforming growth factor-beta (TGF-beta) serum levels were measured by ELISA, relative expression of c-Fos, matrix metalloproteinase 3 and 9 (MMP-3 and -9) were assessed by RT-PCR. Clinical parameters, including anthropometric variables - based on the original Ghent criteria were also analyzed. RESULTS: Among patients with aortic dissection, TGF-beta serum level was elevated (43.78 +/- 6.51 vs. 31.64 +/- 4.99 ng/l, p < 0.0001), MMP-3 was up-regulated (Ln2alpha = 1.87, p = 0.062) and striae atrophicae were more common (92% vs. 41% p = 0.027) compared to the annuloaortic ectasia group. CONCLUSIONS: We found three easily measurable parameters (striae atrophicae, TGF-beta serum level, MMP-3) that may help to predict the risk of aortic dissection in MFS. Based on these findings a new classification of MFS, that is benign or malignant is also proposed, which could be taken into consideration in determining the timing of prophylactic ARR
- …