Exact monopole instantons and cosmological solutions in string theory from abelian dimensional reduction

We compute the exact string vacuum backgrounds corresponding to the non-compact coset theory $SU(2,1)/SU(2)$. The conformal field theory defined by the level $k= 4$ results in a five dimensional singular solution that factorizes in an asymptotic region as the linear dilaton solution and a $S^3$ model. It presents two abelian compact isometries that allow to reinterpreting it from a four dimensional point of view as a stationary and magnetically charged space-time resembling in some aspects the Kerr-Newman solution of general relativity. The $k=\frac{13}{7}$ theory on the other hand describes a cosmological solution that interpolates between a singular phase at short times and a $S^1 \times S^2$ universe after some planckian times.Comment: 18 pages, section 5 replaced by 5 and 6, references added; to appear in Phys. Rev.

La obturación de valles por procesos de ladera: el origen de La Vega de Metztitlan (México)

[Resumen] En las estribaciones de la Sierra Madre Oriental (México) se localiza el lago de Metztitlán y la vega del mismo nombre. Su origen se debe a la obturación del valle por un importante deslizamiento y posteriormente un desprendimiento. En este trabajo se exponen los primeros resultados del estudio geomorfológico, se aporta una cartografía de detalle y se propone una primera explicación de la evolución del área.[Abstract] The lake and valley of Metztilán is located in Sierra Madre Oriental range (Mexico). Its origin is due to the slope collapse after great rockslide. This paper exposes the firsts geomorphologic analysis of the feature, and includes and detailed geomorphologic map. A different evolution phases is determined

Estudio descriptivo del programa de rehabilitación cardiaca de la Clínica Las Américas

Estudio descriptivo de antes y después que demuestra la eficacia y seguridad del Programa de Rehabilitación Cardiaca de la Clínica Las Américas, con base en un seguimiento a 77 pacientes, en el que se evidenció mejoría de la capacidad funcional así como disminución del perímetro abdominal y de las cifras basales de presión arterial sistólica y diastólica sin complicaciones severas, en todos los tipos de paciente, independientemente de la fracción de eyección o las variables demográficas. De igual forma, se describen las características epidemiológicas de la población y de los factores de riesgo cardio-cerebro-vascular.A before and after descriptive study that shows the efficacy and safety of the Cardiac Rehabilitation Program of the Clínica Las Americas, based on the follow-up of 77 patients in which we evidenced improvement in functional capacity as well as a decrease of abdominal girth and baseline values of systolic and diastolic blood pressure without severe complications in all type of patients, regardless of ejection fraction or demographic variables. Likewise, we describe the epidemiological characteristics of the population and the cardio-cerebro-vascular risk factors

Quantification of Lansoprazole in Oral Suspension by Ultra-High-Performance Liquid Chromatography Hybrid Ion-Trap Time-of-Flight Mass Spectrometry

An LC-MS/MS method was developed and validated to be used as a stability indicating assay for the study of a 3 mg/mL lansoprazole oral suspension. The method utilizes a UPLC (ultra-performance liquid chromatography) column and unique mass spectrometric detection (ion-trap time-of-flight (IT-TOF)) to achieve a sensitive (LOD 2 ng/mL), accurate, and reproducible quantification of lansoprazole. This method reports an intraday and interday coefficient of variation of 2.98 ± 2.17% (n = 5 for each concentration for each day) and 3.07 ± 0.89% (n = 20 for each concentration), respectively. Calibration curves (5–25 μg/mL) were found to be linear with an R2 value ranging from 0.9972 to 0.9991 on 4 different days. Accuracy of the assay, expressed as % error, ranged from 0.30 to 5.22%. This method is useful for monitoring the stability of lansoprazole in oral suspension

Administración y planeación general de la formación profesional

El texto presenta un esquema completo de toda la metodología que se utilizaba para programar la formación profesional en el SENA, con el propósito de dar los elementos, herramientas e ideas generales y específicas que permitieran lograr con éxito la labor del Instructor.The text presents a complete outline of all the methodology that was used to program vocational training at SENA, with the purpose of giving the general and specific elements, tools and ideas that would allow the Instructor's work to be successfully achieved.Introducción -- Objetivo general -- Administración de la Formación Profesional -- Planeación general de la Formación Profesional -- Etapa de planeación -- Etapa de programación -- Etapa de evaluaciónnaDocumento sin fecha, se aproxima fecha a la década39 página

Marrying research evidence and policies in Latin America and the Caribbean: The Case of Violence

Violence is probably the most important public health problem in Latin America and the Caribbean. Despite the efforts to attach that problem, research and policies do not feedback each other in an apropiate way. There is need for develop implementation research in the region in order to reduce that gap.Fil: Ardila Gómez, Sara Elena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Lanus. Departamento de Salud Comunitaria; Argentina. Universidad de Buenos Aires. Facultad de Psicología. Área de Salud Pública y Salud Mental; ArgentinaFil: Lugo Palacios, D.. London School Of Hygiene And Tropical Medicine; Reino UnidoFil: Vargas Palacios, E.. No especifíca

Feasibility study to characterize the production of antineutrons in high energy pppp collisions through charge exchange interactions

Simulations to evaluate the feasibility of $\bar{n}$ identification and kinematic characterization via the hadronic charge exchange (CEX) interaction $n+\bar{n}\rightarrow p+\bar{p}$ are reported. The target neutrons are those composing the silicon nuclei of which inner tracking devices present in LHC experiments are made. Simulations of $pp$ collisions in PYTHIA were carried out at different energies to investigate $\bar{n}$ production and the expected $\bar{n}$ energy spectra. Then, two types of GEANT4 simulations were performed, placing an $\bar{n}$ point source at the ALICE primary vertex as a working example. In the first simulation, the $E_k$ was kept at an arbitrary (1 GeV) fix value to develop an $\bar{n}$ identification and kinematics reconstruction protocol. The second GEANT4 simulation used the resulting PYTHIA at $\sqrt{s_{pp}}=13$ TeV $\bar{n}$ energy spectra. In both simulations, the occurrence of CEX interactions was identified by the unique outgoing $\bar{p}$. The simplified simulation allowed to estimate a 0.11% CEX-interaction identification efficiency at $E_k = 1$ GeV. The $p$ CEX-partner identification is challenging because of the presence of silicon nucleus-fragmentation protons. Momentum correlations between the $\bar{n}$ and all possible $\bar{p}p$ pairs showed that $p$ CEX-partner identification and $\bar{n}$ kinematics reconstruction corresponds to minimal momentum-loss events. The use of ITS $dE/dx$ information is found to improve $\bar{n}$ identification and kinematic characterization in both simulations. The final protocol applied to the realistic simulation resulted in a $\bar{n}$ identification and kinematic reconstruction efficiency of 0.006%, based solely on $\bar{p}p$ pair observable. Thus, the expected rate of identified and kinematically reconstructed $\bar{n}$ should lie in the order of 100,000 per second, illustrating the feasibility of the method.Comment: 6 pages, 11 figure