Universe acceleration and fine structure constant variation in BSBM theory

In this work we investigate the utility of using SNe Ia observations in constraining the cosmological parameters in BSBM theory where a scalar field is responsible for both fine structure constant variation and late time universe acceleration. The model is discussed in the presence of an exponential self potential for the scalar field. Stability and phase space analysis of the solutions are studied. The model is tested against observational data for Hubble parameter and quasar absorption spectra. With the best fitted model parameters, the theory predicts a good match with the experimental results and exhibits fine structure constant variation. The analysis also shows that for the equation of state parameter, recent universe acceleration and possible phantom crossing in future is forecasted.Comment: 14 pages, 10 figures, final version with minor modification accepted to be published in JCA

Neuroimagen del linfoma primario del sistema nervioso central en pacientes inmunodeprimidos

ResumenObjetivosEl linfoma primario del sistema nervioso central (LPSNC) es una entidad rara con un pronóstico fatal. Dado el aumento en el número de casos con inmunosupresión adquirida, nuestros objetivos son estudiar las características epidemiológicas y neurorradiológicas de aquellos pacientes inmunodeprimidos con diagnóstico de LPSNC con afectación cerebral e investigar si existen diferencias entre los pacientes con el virus de la inmunodeficiencia humana (VIH) positivo y negativo.Materiales y métodosSe realizó un estudio descriptivo y retrospectivo de los pacientes inmunodeprimidos con afectación cerebral por LPSNC, diagnosticados durante los últimos 13 años en 2 hospitales de referencia. Se evaluaron múltiples variables. El nivel de significación estadística utilizado fue p<0,05.ResultadosEl grupo VIH-positivo tenía una media de edad de 36,82±5,4 años, frente a los 55,60 ± 21,43 años de los pacientes VIH-negativo (p<0,022). Los pacientes VIH-positivo tuvieron una media de 1,27 ± 0,65 lesiones por paciente, mientras que en el grupo VIH-negativo fue de 2,60 ± 1,78 (p<0,039). El 18,2% (n=2) del grupo VIH-positivo y el 80% (n=8) del grupo VIH-negativo presentaron lesiones homogéneas (p<0,005). Ningún paciente VIH-positivo tuvo afectación del cuerpo calloso, pero el grupo VIH-negativo presentó un 50% (n=5) de afectación (p<0,012).ConclusionesEl LPSNC en pacientes inmunodeprimidos puede presentar múltiples características en las imágenes. Existen diferencias entre los pacientes VIH positivo y negativo, por lo que es importante reconocerlas para establecer un manejo y tratamiento diferente entre ambos grupos.AbstractPurposesPrimary central nervous system lymphoma (PCNSL) is a rare tumour with poor prognosis. Due to the increased number of patients with acquired immunodeficiency, our purposes are to describe epidemiological and imaging findings in immunodeficient patients with PCNSL of the brain and to study the differences between HIV-positive and HIV-negative patients with PCNSL.Materials and methodsA retrospective, descriptive study was performed with immunodeficient patients diagnosed of PCNSL of the brain during the last 13 years in two reference hospitals. Twenty-one patients fulfilled the inclusion criteria. Multiple variables were evaluated. Significance was defined as p<0.05.ResultsHIV-positive group was a mean age of 36,82±5,4 years and the mean age in HIV-negative group was 55,60±21,43 years (p<0,022). The mean number of lesions was 1,27±0,65 in HIV-positive group and 2,60±1,78 in HIV-negative group (p<0,039). The lesions were homogeneous in 18,2% (n=2) HIV-positive group and 80% (n=8) in HIV-negative group (p<0,005). No HIV-positive patient and 50% (n=5) of HIV-negative patients showed corpus callosum involvement (p<0,012).ConclusionsPCNSL in immunodeficient patients is associated with a large spectrum of radiological findings. There were differences between HIV-positive and HIV-negative patients, is important recognize these differences as the therapeutic management of these two groups vary

Efficient RDF Interchange (ERI) format for RDF data streams

RDF streams are sequences of timestamped RDF statements or graphs, which can be generated by several types of data sources (sensors, social networks, etc.). They may provide data at high volumes and rates, and be consumed by applications that require real-time responses. Hence it is important to publish and interchange them efficiently. In this paper, we exploit a key feature of RDF data streams, which is the regularity of their structure and data values, proposing a compressed, efficient RDF interchange (ERI) format, which can reduce the amount of data transmitted when processing RDF streams. Our experimental evaluation shows that our format produces state-of-the-art streaming compression, remaining efficient in performance

Функция Грина в гравистатике Эйнштейна

We apply the method of Green's function to generating axisymmetric static solutions to Einstein's equations.В статье применяется метод функции Грина для построения статических аксиально-симметричных решений уравнений Эйнштейна

High-fidelity method for a single-step N-bit Toffoli gate in trapped ions

Conditional multiqubit gates are a key component for elaborate quantum algorithms. In a recent work, Rasmussen et al. [Phys. Rev. A 101, 022308 (2020)] proposed an efficient single-step method for a prototypical multiqubit gate, a Toffoli gate, based on a combination of Ising interactions between control qubits and an appropriate driving field on a target qubit. Trapped ions are a natural platform to implement this method, since Ising interactions mediated by phonons have been demonstrated in increasingly large ion crystals. However, the simultaneous application of these interactions and the driving field required for the gate results in undesired entanglem

ICA H 556 híbrido precoz de maíz para choclos.

Figuran algunas consideraciones generales con relación al uso de híbridos varietales en maíz y la forma como se obtiene la semilla. Señala las principales características agronómicas y morfológicas de las 2 variedades que dieron orígen al híbrido ICA H-556, a saber : Cundinamarca 431 y Cacahuacintle. Destaca las características más sobresalientes del híbrido mencionado, indicando que se recomienda exclusivamente para choclos. Figuran recomendaciones sobre su cultivoMaíz-Zea may

Conformally flat spacetimes and Weyl frames

We discuss the concepts of Weyl and Riemann frames in the context of metric theories of gravity and state the fact that they are completely equivalent as far as geodesic motion is concerned. We apply this result to conformally flat spacetimes and show that a new picture arises when a Riemannian spacetime is taken by means of geometrical gauge transformations into a Minkowskian flat spacetime. We find out that in the Weyl frame gravity is described by a scalar field. We give some examples of how conformally flat spacetime configurations look when viewed from the standpoint of a Weyl frame. We show that in the non-relativistic and weak field regime the Weyl scalar field may be identified with the Newtonian gravitational potential. We suggest an equation for the scalar field by varying the Einstein-Hilbert action restricted to the class of conformally-flat spacetimes. We revisit Einstein and Fokker's interpretation of Nordstr\"om scalar gravity theory and draw an analogy between this approach and the Weyl gauge formalism. We briefly take a look at two-dimensional gravity as viewed in the Weyl frame and address the question of quantizing a conformally flat spacetime by going to the Weyl frame.Comment: LATEX - 18 page

Medical imaging: Foundations and scope

Indexación: Scopus; Radalyc.En la actualidad es innegable la utilidad de las diversas modalidades de imagenología médica como apoyo clínico tanto en la generación de diagnósticos de un buen número de enfermedades como en la planeación de tratamientos tendientes a proporcionar una alternativa de solución a las personas que, por una u otra razón, manifiestan algún desequilibrio en su salud. Entre las modalidades imagenológicas que, frecuentemente, se utilizan en el ámbito médico se pueden mencionar: Ultrasonido (US), Resonancia Magnética (MRI), Tomografía Computarizada sencilla (CT) y multicapa (MSCT), Tomografía Computarizada por Emisión de Positrones (PET) y Tomografía Computarizada por Emisión de Fotones simples (SPECT). En este sentido, este artículo tiene como finalidad presentar una descripción ordenada, coherente y sistemática de cada una de las mencionadas modalidades y establecer la vinculación de la MSCT con situaciones clínicas íntimamente relacionadas con la anatomía cardiaca y procesos de hipertensión. La razón por la cual se hace énfasis en la MSCT es debido a que, por una parte, se cuenta con un número importante de bases de datos tanto de sujetos fisiológicos como de sujetos patológicos y, por la otra, que se tiene previsto presentar un conjunto de técnicas computacionales que serán exploradas en el desarrollo de futuras investigaciones en el contexto de aspectos anatómico-cardiológicos que influyen directa o indirectamente en la aparición, desarrollo y prevalencia de procesos hipertensivos.Nowdays, several forms of medical imaging are usefulness in clinical support for both diagnostics diseases generation and treatment planning designed to provide an alternative solution to people who, for one or another reason, manifest an imbalance in your health. Among the imaging modalities that frequently are used in the medical field may include: Ultrasound (US), magnetic resonance imaging (MRI), simple computed tomography (CT) and multilayer computed tomography (MSCT), CT positron emission tomography (PET) Computed tomography and single photon emission (SPECT). In this sense, this article presents an orderly, coherent and systematic description of these modalities and it establishes relationship with the MSCT modality and clinical situations closely related to cardiac anatomy and hypertension processes. The reason emphasis on MSCT is done is because, on the one hand, we have a large number of databases both physiological subjects and pathological subjects and, on the other, we plan to present a set of computational techniques that will be explored in future research, in the context of cardiologic anatomical aspects, with directly or indirectly influence in the emergence, development and prevalence of hypertensive processes.http://www.redalyc.org/articulo.oa?id=5594990700

FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium

Background:Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium. Methods:Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression. Results:Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95 confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2. Conclusion:Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2. © 2014 Cancer Research UK