Application of the Verlet method for the simulation of a gravitational system of n bodies

En este trabajo se plantea una solución numérica (simulación por software) del “problema de n cuerpos” que interactúan gravitacionalmente basada en la formulación de Verlet. Adicionalmente se diseña un programa que gráficamente muestra los resultados de esta solución numérica, que detalla las diferentes trayectorias, para diferentes condiciones de masa, velocidad y distancia entre los n objetos que interactúan. La interacción del usuario con la interfaz gráfica, se realiza partícula a partículaIn this paper we propose a numerical solution (software simulation) of the "problem of n bodies" that interact gravitationally based on the formulation of Verlet. Additionally a program is designed that graphically shows the results of this numerical solution, which details the different trajectories, for different conditions of mass, speed and distance between the n objects that interact. The interaction of the user with the graphical interface, is performed particle by particle.Peer Reviewe

ESTUDIO COMPARATIVO DEL COMPORTAMIENTO FORRAJERO DE SIETE ECOTIPOS DE DIGITARIAS EN SUELOS DE ESPARTILLAR DEL CHACO CENTRAL.

Fueron evaluados siete ecotipos de Digitarias en la Estancia La Hermosa, ubicada en el distrito de Tte. 1º Irala Fernández, departamento de Pte. Hayes, Chaco Central. El periodo evaluado estuvo comprendido entre marzo de 2005 a enero del 2006. Se evaluaron la producción de materia seca en los periodos de otoño, invierno, primavera y verano. El diseño experimental adoptado fue el de bloques completamente al azar con siete tratamientos y tres repeticiones. Los tratamientos consistieron en cada ecotipo de Digitaria. Los cortes de evaluación se efectuaron cada 28 días y en forma sucesiva por un periodo de 11 meses. En el periodo otoñal se registraron rendimientos satisfactorios siendo el ecotipo más productivo Digitaria sp. cv. GL 5 con 8810 kg/ha de masa seca, y el menos productivoDigitaria eriantha var pentzii con 3405 kg/ha. En el periodo de invierno los rendimientos de masa seca disminuyeron en todos los ecotipos así Digitaria sp. cv. GL 5 produjo 2968 kg /ha que fue la mayor producción registrada y 1205 kg/ha la menor producción paraDigitaria eriantha cv. ATF 616. Durante el periodo primaveral se produjo un aumento en la producción de todos los ecotipos siendo Digitaria sp. cv. GL 5 con 5067 kg/ha de masa seca la más productiva en este periodo y Digitaria eriantha var pentzii el de menor rendimiento con 2053 kg/ha. Así mismo en el periodo estival todos los ecotipos expresaron su máxima producción, Digitaria sp. cv. GL 5 fue una vez más el ecotipo con mejor rendimiento con 11 120 kg/ha de masa seca y Digitaria eriantha var pentzii el ecotipo de con más bajo rendimiento

Separation of Oligosaccharides from Lotus Seeds via Medium-pressure Liquid Chromatography Coupled with ELSD and DAD

peer-reviewedLotus seeds were identified by the Ministry of Public Health of China as both food and medicine. One general function of lotus seeds is to improve intestinal health. However, to date, studies evaluating the relationship between bioactive compounds in lotus seeds and the physiological activity of the intestine are limited. In the present study, by using medium pressure liquid chromatography coupled with evaporative light-scattering detector and diode-array detector, five oligosaccharides were isolated and their structures were further characterized by electrospray ionization-mass spectrometry and gas chromatography-mass spectrometry. In vitro testing determined that LOS3-1 and LOS4 elicited relatively good proliferative effects on Lactobacillus delbrueckii subsp. bulgaricus. These results indicated a structure-function relationship between the physiological activity of oligosaccharides in lotus seeds and the number of probiotics applied, thus providing room for improvement of this particular feature. Intestinal probiotics may potentially become a new effective drug target for the regulation of immunity

Uniqueness and Nondegeneracy of Ground States for (−Δ)sQ+Q−Qα+1=0(-\Delta)^s Q + Q - Q^{\alpha+1} = 0 in R\mathbb{R}

We prove uniqueness of ground state solutions $Q = Q(|x|) \geq 0$ for the nonlinear equation $(-\Delta)^s Q + Q - Q^{\alpha+1}= 0$ in $\mathbb{R}$, where $0 < s < 1$ and $0 < \alpha < \frac{4s}{1-2s}$ for $s < 1/2$ and $0 < \alpha < \infty$ for $s \geq 1/2$. Here $(-\Delta)^s$ denotes the fractional Laplacian in one dimension. In particular, we generalize (by completely different techniques) the specific uniqueness result obtained by Amick and Toland for $s=1/2$ and $\alpha=1$ in [Acta Math., \textbf{167} (1991), 107--126]. As a technical key result in this paper, we show that the associated linearized operator $L_+ = (-\Delta)^s + 1 - (\alpha+1) Q^\alpha$ is nondegenerate; i.\,e., its kernel satisfies $\mathrm{ker}\, L_+ = \mathrm{span}\, \{Q'\}$. This result about $L_+$ proves a spectral assumption, which plays a central role for the stability of solitary waves and blowup analysis for nonlinear dispersive PDEs with fractional Laplacians, such as the generalized Benjamin-Ono (BO) and Benjamin-Bona-Mahony (BBM) water wave equations.Comment: 45 page

Evaluación fisicoquímica y capacidad antioxidante de chiltepín silvestre de Nuevo León, México.

La demanda del chile piquín por sus amplios atributos, además de su importancia socioeconómica como recurso natural en las áreas rurales y su potencial como nueva opción productiva en el noreste de México, ha motivado la realización de varios estudios. Por lo anterior en este trabajo se realizó una evaluación fisicoquímica y actividad antioxidante de chiltepín silvestre de Nuevo León, México. Se tuvieron seis tratamientos, con base en los tres sitios de colecta y dos índices de madurez. Se determinaron las siguientes variables de estudio; peso, largo ancho, pH, °Brix, acidez titulable, color y actividad antioxidante por DPPH. El diseño experimental utilizado fue completamente al azar y la prueba de comparaciones de medias de Tukey (p≤ 0.05). El mayor peso y tamaño se observó en los frutos de chiltepín verdes, mientras que los valores más altos de luminosidad e intensidad se observaron en los frutos de chiltepín rojos. En relación al contenido de sólidos solubles totales y acidez titulable los frutos de chiltepín rojo presentaron el mayor contenido en relación a los frutos de chiltepín verdes. Sin embargo la mayor actividad antioxidante se encontró en los frutos de chiltepín verdes

Androgen receptor condensates as drug targets

Transcription factors are among the most attractive therapeutic targets, but are considered largely undruggable. Here we provide evidence that small molecule-mediated partitioning of the androgen receptor, an oncogenic transcription factor, into phase-separated condensates has therapeutic effect in prostate cancer models. We show that the phase separation capacity of the androgen receptor is driven by aromatic residues and short unstable helices in its intrinsically disordered activation domain. Based on this knowledge, we developed tool compounds that covalently attach aromatic moieties to cysteines in the receptors’ activation domain. The compounds enhanced partitioning of the receptor into condensates, facilitated degradation of the receptor, inhibited androgen receptor-dependent transcriptional programs, and had antitumorigenic effect in models of prostate cancer and castration-resistant prostate cancer in vitro and in vivo. These results establish a generalizable framework to target the phase- separation capacity of intrinsically disordered regions in oncogenic transcription factors and other disease-associated proteins with therapeutic intent

The TRAPSENSOR facility: an open-ring 7 tesla Penning trap for laserbased precision experiments

APenning-trap facility for high-precision mass spectrometry based on a novel detection method has been built. This method consists in measuring motional frequencies of singly-charged ions trapped in strong magnetic fields through the fluorescence photons from laser-cooled 40Ca+ ions, to overcome limitations faced in electronic single-ion detection techniques. The key element of this facility is an open-ring Penning trap coupled upstream to a preparation Penning trap similar to those used at Radioactive Ion Beam facilities. Here we present a full characterization of the trap and demonstrate motional frequency measurements of trapped ions stored by applying external radiofrequency fields in resonance with the ions’ eigenmotions, in combination with time-of-flight identification. The infrastructure developed to observe the fluorescence photons from 40Ca+, comprising the 12 laser beams and the optical system to register the image in a high-sensitive CCD sensor, has been proved by taking images of the trapped and cooled 40Ca+ ions. This demonstrates the functionality of the proposed laser-based mass-spectrometry technique, providing a unique platform for precision experiments with implications in different fields of physics.This work was supported by the European Research Council (contract no. 278648-TRAPSENSOR), from the SpanishMINECO/ FEDER (project nos. FPA2012-32076, FPA2015-67694-P, FIS2015-69983-P, UNGR10-1E- 501, UNGR13-1E-1830), Ramón y Cajal Grant RYC-2012-11391, Juan de la Cierva grant IJCI-2015-26091, Centro Nacional de Partículas, Astropartículas y Nuclear CPAN13-TM01, and ‘Sistema Nacional de Garantía Juvenil y del Programa Operativo de Empleo Juvenil’; from the SpanishMECD(PhD grant nos. FPU15-04679 and FPU17/02596); from Junta de Andalucía/FEDER (project no. IE-57131) and ‘Programa de Empleo Juvenil; from Basque Government (PhD grant no. PRE-2015-1-0394) and (project no. IT986-16), and from the University of Granada ‘Plan propio-Programa de Intensificación de la Investigación PP2017-PRI.I-04’. I.A, L.L. and E.S acknowledge also support from projects OpenSuperQ (820363) and QMiCS (820505) of the EUFlagship on Quantum Technologies

Prevention of diet-induced obesity by apple polyphenols in Wistar rats through regulation of adipocyte gene expression and DNA methylation patterns

This study was conducted to determine the mechanisms implicated in the beneficial effects of apple polyphenols (APs) against diet-induced obesity in Wistar rats, described in a previous study from our group. Supplementation of high-fat sucrose diet with AP prevented adiposity increase by inhibition of adipocyte hypertrophy. Rats supplemented with AP exhibited improved glucose tolerance while adipocytes isolated from these rats showed an enhanced lipolytic response to isoproterenol. AP intake led to reduced Lep, Plin, and sterol regulatory element binding transcription factor 1 (Srebf1) mRNA levels and increased aquaporin 7 (Aqp7), adipocyte enhancer binding protein 1 (Aebp1), and peroxisome proliferator-activated receptor gamma co-activator 1 alpha (Ppargc1a) mRNA levels in epididymal adipocytes. In addition, we found different methylation patterns of Aqp7, Lep, Ppargc1a, and Srebf1 promoters in adipocytes from apple-supplemented rats compared to high-fat sucrose fed rats. The administration of AP protects against body weight gain and fat deposition and improves glucose tolerance in rats. We propose that AP exerts the antiobesity effects through the regulation of genes involved in adipogenesis, lipolysis, and fatty acid oxidation, in a process that could be mediated in part by epigenetic mechanisms