Estimación paramétrica del modelo de un mini-helicóptero robot usando un algoritmo genético y Matlab-Simulink

Basándose en el modelo matemático para un mini-helicóptero robot implementado en Matlab-Simulink y métodos heurísticos, específicamente un algoritmo genético (AG), se logro hacer la estimación de 16 parámetros en forma simultánea a nivel de simulación. Los resultados son altamente satisfactorios, teniendo en cuenta que fueron estimados con 12 salidas

Enfermedad carcinoide cardiaca multivalvular

ResumenHombre de 67 años de edad, enviado a valoración ecocardiográfica por cuadro clínico de 6meses de evolución con: disnea de esfuerzo, edemas de miembros inferiores y fatiga. Se encuentra doble lesión de la válvula tricúspide con: estenosis e insuficiencia severa, insuficiencia pulmonar severa; y compromiso valvular izquierdo con: insuficiencia mitral y aórtica severas, asociadas a engrosamiento y rigidez valvular. El paciente tenía como antecedente tumor neuroendocrino de íleon, metastásico a pulmón e hígado.En este caso se discuten los hallazgos ecocardiográficos característicos del síndrome carcinoide con compromiso multivalvular como hallazgo inusual de este raro síndrome.AbstractA 67 year-old man is sent to echocardiographic assessment for 6 month history of exertional: dyspnea, edema of the lower extremities, fatigue, double lesions in tricuspid valve with: severe stenosis and severe regurgitation, severe pulmonary valve regurgitation; and left side valvular disease with: severe aortic regurgitation and severe mitral regurgitation, all of them associated with valvular thickening, rigidity, in a patient with history of neuroendocrine tumor, with lung and liver metastases.This case discuss the echocardiographic findings suggestive of carcinoid multivalvular and left side valvular disease as unusual finding in this rare syndrome

Femtosecond pulses and dynamics of molecular photoexcitation: RbCs example

We investigate the dynamics of molecular photoexcitation by unchirped femtosecond laser pulses using RbCs as a model system. This study is motivated by a goal of optimizing a two-color scheme of transferring vibrationally-excited ultracold molecules to their absolute ground state. In this scheme the molecules are initially produced by photoassociation or magnetoassociation in bound vibrational levels close to the first dissociation threshold. We analyze here the first step of the two-color path as a function of pulse intensity from the low-field to the high-field regime. We use two different approaches, a global one, the 'Wavepacket' method, and a restricted one, the 'Level by Level' method where the number of vibrational levels is limited to a small subset. The comparison between the results of the two approaches allows one to gain qualitative insights into the complex dynamics of the high-field regime. In particular, we emphasize the non-trivial and important role of far-from-resonance levels which are adiabatically excited through 'vertical' transitions with a large Franck-Condon factor. We also point out spectacular excitation blockade due to the presence of a quasi-degenerate level in the lower electronic state. We conclude that selective transfer with femtosecond pulses is possible in the low-field regime only. Finally, we extend our single-pulse analysis and examine population transfer induced by coherent trains of low-intensity femtosecond pulses.Comment: 25 pages, 12 figure

Cost estimation for the monitoring instrumentation of landslide early warning systems

Landslides are socio-natural hazards. In Colombia, for example, these are the most frequent hazards. The interplay of climate change and the mostly informal growth of cities in landslide-prone areas increases the associated risks. Landslide early warning systems (LEWSs) are essential for disaster risk reduction, but the monitoring component is often based on expensive sensor systems. This study presents a data-driven approach to localize landslide-prone areas suitable for low-cost and easy-to-use LEWS instrumentation, as well as to estimate the associated costs. The approach is exemplified in the landslide-prone city of Medellín, Colombia. A workflow that enables decision-makers to balance financial costs and the potential to protect exposed populations is introduced. To achieve this, city-level landslide susceptibility is mapped using data on hazard levels, landslide inventories, geological and topographic factors, and a random forest model. Then, the landslide susceptibility map is combined with a population density map to identify highly exposed areas. Subsequently, a cost function is defined to estimate the cost of LEWS monitoring sensors at the selected sites, using lessons learned from a pilot LEWS in Bello Oriente, a neighbourhood in Medellín. This study estimates that LEWS monitoring sensors could be installed in several landslide-prone areas with a budget ranging from EUR 5 to EUR 41 per person (roughly COP 23 000 to 209 000), improving the resilience of over 190 000 exposed individuals, 81 % of whom are located in precarious neighbourhoods; thus, the systems would particularly reduce the risks of a social group of very high vulnerability. The synopsis of all information allows us to provide recommendations for stakeholders on where to proceed with LEWS instrumentation. These are based on five different cost-effectiveness scenarios. This approach enables decision-makers to prioritize LEWS deployment to protect exposed populations while balancing the financial costs, particularly for those in precarious neighbourhoods. Finally, the limitations, challenges, and opportunities for the successful implementation of a LEWS are discussed.</p

Grinding methods effects on the synthesis of Potassium-Sodium Niobate powders by oxide mixing

Los materiales piezoeléctricos son ampliamente utilizados en dispositivos electrónicos. Tradicionalmente, para tales aplicaciones, se han utilizado diversos materiales a base de plomo; sin embargo, debido al daño causado por este elemento, se han desarrollado materias primas con características similares que no causen un impacto negativo a la sociedad o al medio ambiente. Un material con estas características es el niobato de potasio y sodio K0.5Na0.5 Nbo3. En este artículo, se realizaron análisis termogravimétricos, estructurales y microestructurales para los polvos del sistema K0.5Na0.5 Nbo3 obtenidos mediante mezcla de óxido, con el objetivo de determinar el efecto y la eficiencia de la molienda utilizando molinos de bolas, planetario y horizontal en la etapa de mezcla de los reactivos, para la producción del polvo final. Se determinó que el uso de la molienda horizontal y la calcinación a 900 °C crean las condiciones óptimas para obtener polvos  con una estructura y microestructura adecuadas para continuar los procesos de densificación y/o dopaje.Piezoelectric materials are widely used in electronic devices and, traditionally, various lead-based materials have been implemented in such applications. However, because of the damage caused by lead, other materials with similar characteristics that do not cause a negative impact on human health and the environment have been developed. A material with those characteristics is potassium-sodium niobite K0.5Na0.5 Nbo3. In this study, we investigate the thermogravimetric, structural, and microstructural properties of powders of such system obtained through oxide mixing with the aim of establishing the effect and efficiency of grinding (using a horizontal and a planetary ball mill grinder) on the production of the final material. It was determined that horizontal grinding and calcination at 900°C create the optimal conditions for obtaining K0.5Na0.5 Nbo3 powders, by oxide mixing, with the adequate structure and microstructure to continue the densification and/or doping processes

Smoking Social Norms Among Spanish-Speaking Mexican-Origin Persons Who Smoke

In the United States, smoking rates increase with greater acculturation among Mexican-origin women, but not among men. Conversely, greater acculturation is associated with higher likelihood of quitting among Mexican-origin men who smoke, but not among women who smoke. Long-standing speculation is that adoption of smoking social norms in the U.S. that are less restrictive for women and more restrictive for men compared to smoking social norms in Mexico may account for these patterns. However, it is unknown whether persons who smoke actually perceive such differential norms. The current study characterized smoking social norms in the U.S. and Mexico among Spanish-speaking Mexican-origin persons who smoke. Two hundred and ninety Mexican-origin persons who smoke were surveyed on descriptive and injunctive norms for men and women in the U.S. and Mexico. Estimated means for smoking social norms in the U.S. and Mexico were compared separately among men and women. Among men, mean descriptive and injunctive norms in Mexico were significantly higher than those for the U.S. Among women, neither mean descriptive nor injunctive norms were significantly different between the U.S. and Mexico. Mexican-origin women who smoke perceive smoking among women as equally common and similarly unacceptable in the U.S. and Mexico. Findings do not support speculation that differential social norms may explain the acculturation-smoking relationship among Mexican-origin women. Mexican-origin men who smoke perceive smoking among men both less common and less acceptable in the U.S. compared to Mexico. Social norms should be investigated as a mechanism of the acculturation-cessation relationship among Mexican-origin men. Understanding direct and indirect influences of social norms on cessation among Mexican-origin men stands to inform tailoring of interventions

Modulated-laser source induction system for remote detection of infrared emissions of high explosives using laser-induced thermal emission

In a homeland security setting, the ability to detect explosives at a distance is a top security priority. Consequently, the development of remote, noncontact detection systems continues to represent a path forward. In this vein, a remote detection system for excitation of infrared emissions using a CO2 laser for generating laser-induced thermal emission (LITE) is a possible solution. However, a LITE system using a CO2 laser has certain limitations, such as the requirement of careful alignment, interference by the CO2 signal during detection, and the power density loss due to the increase of the laser image at the sample plane with the detection distance. A remote chopped-laser induction system for LITE detection using a CO2 laser source coupled to a focusing telescope was built to solve some of these limitations. Samples of fixed surface concentration (500 μg∕cm2) of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) were used for the remote detection experiments at distances ranging between 4 and 8 m. This system was capable of thermally exciting and capturing the thermal emissions (TEs) at different times in a cyclic manner by a Fourier transform infrared (FTIR) spectrometer coupled to a gold-coated reflection optics telescope (FTIR-GT). This was done using a wheel blocking the capture of TE by the FTIR-GT chopper while heating the sample with the CO2 laser. As the wheel moved, it blocked the CO2 laser and allowed the spectroscopic system to capture the TEs of RDX. Different periods (or frequencies) of wheel spin and FTIR-GT integration times were evaluated to find dependence with observation distance of the maximum intensity detection, minimum signal-to-noise ratio, CO2 laser spot size increase, and the induced temperature incremen

Efecto antiinflamatorio de la izalpinina derivada de Chromolaena leivensis: edema de la pata inducido por λ-carragenina y modelo in silico

El flavonoide izalpinina se aisló de las partes aéreas de Chromolaena leivensis. Su determinación estructural se llevó a cabo mediante técnicas espectroscópicas de EM y RMN (1H, 13C). Se evaluó el efecto antiinflamatorio de este compuesto en un modelo de edema plantar inducido por carragenina en ratas. La inflamación de la pata se midió a intervalos de una hora durante siete horas tras la administración de -carragenano. Se evaluaron los niveles séricos de creatina quinasa (CK), obteniéndose resultados estadísticamente significativos con los tratamientos a dosis de 10 mg/kg (* p < 0,01) y 20 mg/kg (** p < 0,005). El efecto antiinflamatorio del compuesto se evaluó mediante pletismografía, y los resultados mostraron diferencias significativas en las tres concentraciones (10 mg/kg, 20 mg/kg, 40 mg/kg) en la primera y tercera hora tras el tratamiento. * p < 0,05; ** p < 0,001; **** p < 0,0001 frente al grupo de control negativo tratado con vehículo (DMSO). Por último, los análisis de acoplamiento molecular revelan que la izalpinina tiene una fuerte afinidad de unión con cinco proteínas diana implicadas en el proceso inflamatorio. El análisis mediante dinámica molecular permitió demostrar que los complejos ligando-proteína presentan una estabilidad aceptable, con valores de RMSD dentro del rango permitido.The flavonoid izalpinin was isolated from the aerial parts of Chromolaena leivensis. Its structural determination was carried out using MS and NMR spectroscopic techniques (1H, 13C). This compound was evaluated for its anti-inflammatory effect in a rat model on -carrageenan-induced plantar edema. Paw inflammation was measured at one-hour intervals for seven hours following the administration of -carrageenan. Serum creatine kinase (CK) levels were evaluated, obtaining statistically significant results with the treatments at doses of 10 mg/kg (* p < 0.01) and 20 mg/kg (** p < 0.005). The anti-inflammatory effect of the compound was evaluated by using plethysmography, and the results showed significant differences at the three concentrations (10 mg/kg, 20 mg/kg, 40 mg/kg) in the first and third hours after treatment. * p < 0.05; ** p < 0.001; **** p < 0.0001 vs. the negative control group treated with vehicle (DMSO). Lastly, molecular docking analyses reveal that izalpinin has a strong binding affinity with five target proteins involved in the inflammatory process. The analysis using molecular dynamics allowed demonstrating that the ligand–protein complexes present acceptable stability, with RMSD values within the allowed range

Mid-Infrared Laser Spectroscopy Applications I: Detection of Traces of High Explosives on Reflective and Matte Substrates

Mid-infrared (MIR) lasers have revolutionized infrared vibrational spectroscopy, converting an already dominant spectroscopic analysis technique into an even more powerful, easier to use, and quicker turn-around cadre of versatile spectroscopic tools. A selection of applications, revisited under the umbrella of MIR laser-based properties, very high brightness, collimated beams, polarized sources, highly monochromatic tunable sources, and coherent sources, is included. Applications discussed concern enhanced detection, discrimination, and quantification of high explosives (HEs). From reflectance measurements of chemical residues on highly reflective metallic substrates to reflectance measurements of HEs deposited on non-reflective, matte substrates is discussed. Coupling with multivariate analyses (MVA) techniques of Chemometrics allowed near trace detection of HEs, with sharp discrimination from highly MIR absorbing substrates