Test of CPT Symmetry and Quantum Mechanics with Experimental data from CPLEAR

We use fits to recent published CPLEAR data on neutral kaon decays to $\pi^+\pi^-$ and $\pi e\nu$ to constrain the CPT--violation parameters appearing in a formulation of the neutral kaon system as an open quantum-mechanical system. The obtained upper limits of the CPT--violation parameters are approaching the range suggested by certain ideas concerning quantum gravity.Comment: 9 pages of uuencoded postscript (includes 3 figures

Directed differentiation of human pluripotent stem sells for the generation of high-order kidney organoids

Our understanding in the inherent properties of human pluripotent stem cells (hPSCs) have made possible the development of differentiation procedures to generate three-dimensional tissue-like cultures, so-called organoids. Here we detail a stepwise methodology to generate kidney organoids from hPSCs. This is achieved through direct differentiation of hPSCs in two-dimensional monolayer culture toward the posterior primitive streak fate, followed by induction of intermediate mesoderm-committed cells, which are further aggregated and cultured in three-dimensions to generate kidney organoids containing segmented nephron-like structures in a process that lasts 20 days. We also provide a concise description on how to assess renal commitment during the time course of kidney organoid generation. This includes the use of flow cytometry and immunocytochemistry analyses for the detection of specific renal differentiation markers

Equipamiento solar térmico y certificación de calidad

El presente trabajo resume las actividades que se están llevando a cabo en el marco del proyecto de investigación y desarrollo, “Banco de ensayos y certificación de colectores solares” del Laboratorio de Estudios Sobre Energía Solar (LESES) perteneciente al departamento de Ingeniería Civil de la Facultad regional Buenos Aires, Universidad Tecnológica Nacional. El proyecto, orientado a promover el uso de energía solar térmica, tiene entre sus objetivos la Certificación de Calidad y homologación de colectores y equipos solares integrados para el mercado local. En este contexto, se describe el plan de tareas y las actividades puestas en marcha para lograr la Certificación de Calidad de equipamiento solar térmico, así como también, las barreras encontradas para alcanzar los objetivos en los plazos fijados.The present communication summarises the activities that are being developed, in the project called “Testing bench and certification of solar collectors” financed by the secretary of science and technology of the Buenos Aires regional faculty of National Technological University. The objectives of the project is the certification of quality and the homologation under international standards of solar collectors and integrated solar equipments for the local market. In this context, the plan of tasks and the activities started up to obtain the certification of solar collectors as well as the barriers founded to reach the objectives are explained.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Equipamiento solar térmico y certificación de calidad

El presente trabajo resume las actividades que se están llevando a cabo en el marco del proyecto de investigación y desarrollo, “Banco de ensayos y certificación de colectores solares” del Laboratorio de Estudios Sobre Energía Solar (LESES) perteneciente al departamento de Ingeniería Civil de la Facultad regional Buenos Aires, Universidad Tecnológica Nacional. El proyecto, orientado a promover el uso de energía solar térmica, tiene entre sus objetivos la Certificación de Calidad y homologación de colectores y equipos solares integrados para el mercado local. En este contexto, se describe el plan de tareas y las actividades puestas en marcha para lograr la Certificación de Calidad de equipamiento solar térmico, así como también, las barreras encontradas para alcanzar los objetivos en los plazos fijados.The present communication summarises the activities that are being developed, in the project called “Testing bench and certification of solar collectors” financed by the secretary of science and technology of the Buenos Aires regional faculty of National Technological University. The objectives of the project is the certification of quality and the homologation under international standards of solar collectors and integrated solar equipments for the local market. In this context, the plan of tasks and the activities started up to obtain the certification of solar collectors as well as the barriers founded to reach the objectives are explained.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Contribution of CPLEAR to the physics of the neutral kaon system

We present the physics results of the CP-- and CPT--violation measurements performed by CPLEAR. CPLEAR has experimentally determined for the first time, the violation of T invariance and is able to disentangle all the CP-- and CPT--violating quantities from each other. This allows each of the CPT violating parameters to be determined with a precision of a few $10^{-4}$ and, in particular, the mass and width equality between the \kn and \knb to be tested down to the level of $10^{-19}$ GeV. Moreover, the precision of the CPLEAR measurements allows us to probe for the first time physics on a scale approaching the Planck mass

Measurement of the neutral kaon regeneration amplitude in carbon at momenta below 1 GeV/c

The neutral kaon regeneration amplitude in carbon at momenta between 250 and 750~MeV/$c$ was determined by measuring the interference of inherent and coherently regenerated \PKS\ amplitudes. This interference appears in the rates of initially pure (tagged) \PKz\ and \PaKz\ decaying to \Pgpp\Pgpm\ after crossing a carbon absorber

Experimental tests of CPT symmetry and quantum mechanics at CPLEAR

We review a phenomenological parametrization of an open quantum-mechanical formalism for CPT violation in the neutral kaon system, and constrain the parameters using fits to recent CPLEAR data.We review a phenomenological parametrization of an open quantum-mechanical formalism for CPT violation in the neutral kaon system, and constrain the parameters using fits to recent CPLEAR data

Experimental tests of CPT symmetry and quantum mechanics at CPLEAR

We review a phenomenological parametrization of an open quantum-mechanical formalism for CPT violation in the neutral kaon system, and constrain the parameters using fits to recent CPLEAR data

Understanding the apparent superiority of over-sampling through an analysis of local information for class-imbalanced data

Data plays a key role in the design of expert and intelligent systems and therefore, data preprocessing appears to be a critical step to produce high-quality data and build accurate machine learning models. Over the past decades, increasing attention has been paid towards the issue of class imbalance and this is now a research hotspot in a variety of fields. Although the resampling methods, either by under-sampling the majority class or by over-sampling the minority class, stand among the most powerful techniques to face this problem, their strengths and weaknesses have typically been discussed based only on the class imbalance ratio. However, several questions remain open and need further exploration. For instance, the subtle differences in performance between the over- and under-sampling algorithms are still under-comprehended, and we hypothesize that they could be better explained by analyzing the inner structure of the data sets. Consequently, this paper attempts to investigate and illustrate the effects of the resampling methods on the inner structure of a data set by exploiting local neighborhood information, identifying the sample types in both classes and analyzing their distribution in each resampled set. Experimental results indicate that the resampling methods that produce the highest proportion of safe samples and the lowest proportion of unsafe samples correspond to those with the highest overall performance. The significance of this paper lies in the fact that our findings may contribute to gain a better understanding of how these techniques perform on class-imbalanced data and why over-sampling has been reported to be usually more efficient than under-sampling. The outcomes in this study may have impact on both research and practice in the design of expert and intelligent systems since a priori knowledge about the internal structure of the imbalanced data sets could be incorporated to the learning algorithms

The CPLEAR Electromagnetic Calorimeter

A large-acceptance lead/gas sampling electromagnetic calorimeter (ECAL) was constructed for the CPLEAR experiment to detect photons from decays of $\pi^0$s with momentum $p_{\pi^0} \le 800$ MeV$/c$. The main purpose of the ECAL is to determine the decay vertex of neutral-kaon decays \ko \rightarrow \pi^0\pi^0 \rightarrow 4 \gamma and \ko \rightarrow \pi^0\pi^0\pi^0 \rightarrow 6 \gamma. This requires a position-sensitive photon detector with high spatial granularity in $r$-, $\varphi$-, and $z$-coordinates. The ECAL --- a barrel without end-caps located inside a magnetic field of 0.44 T --- consists of 18 identical concentric layers. Each layer of $1/3$ radiation length (X${_0}$) contains a converter plate followed by small cross-section high-gain tubes of 2640 mm active length which are sandwiched by passive pick-up strip plates. The ECAL, with a total of $6$ X${_0}$, has an energy resolution of $\sigma (E)/E \approx 13\% / \sqrt{E(\mathrm{GeV})}$ and a position resolution of 4.5 mm for the shower foot. The shower topology allows separation of electrons from pions. The design, construction, read-out electronics, and performance of the detector are described