zfit: scalable pythonic fitting

Statistical modeling is a key element in many scientific fields and especially in High-Energy Physics (HEP) analysis. The standard framework to perform this task in HEP is the C++ ROOT/RooFit toolkit; with Python bindings that are only loosely integrated into the scientific Python ecosystem. In this paper, zfit, a new alternative to RooFit written in pure Python, is presented. Most of all, zfit provides a well defined high-level API and workflow for advanced model building and fitting, together with an implementation on top of TensorFlow, allowing a transparent usage of CPUs and GPUs. It is designed to be extendable in a very simple fashion, allowing the usage of cutting-edge developments from the scientific Python ecosystem in a transparent way. The main features of zfit are introduced, and its extension to data analysis, especially in the context of HEP experiments, is discussed.Comment: 12 pages, 2 figure

Correction : Analysis of zero inflated dichotomous variables from a Bayesian perspective: application to occupational health

Zero-inflated models are generally aimed to addressing the problem that arises from having two different sources that generate the zero values observed in a distribution. In practice, this is due to the fact that the population studied actually consists of two subpopulations: one in which the value zero is by default (structural zero) and the other is circumstantial (sample zero). This work proposes a new methodology to fit zero inflated Bernoulli data from a Bayesian approach, able to distinguish between two potential sources of zeros (structural and non-structural). The proposed methodology performance has been evaluated through a comprehensive simulation study, and it has been compiled as an R package freely available to the community. Its usage is illustrated by means of a real example from the field of occupational health as the phenomenon of sickness presenteeism, in which it is reasonable to think that some individuals will never be at risk of suffering it because they have not been sick in the period of study (structural zeros). Without separating structural and non-structural zeros one would be studying jointly the general health status and the presenteeism itself, and therefore obtaining potentially biased estimates as the phenomenon is being implicitly underestimated by diluting it into the general health status. The proposed methodology is able to distinguish two different sources of zeros (structural and non-structural) from dichotomous data with or without covariates in a Bayesian framework, and has been made available to any interested researcher in the form of the bayesZIB R package (https://cran.r-project.org/package=bayesZIB)

Analysis of zero inflated dichotomous variables from a Bayesian perspective : application to occupational health

Background: Zero-inflated models are generally aimed to addressing the problem that arises from having two different sources that generate the zero values observed in a distribution. In practice, this is due to the fact that the population studied actually consists of two subpopulations: one in which the value zero is by default (structural zero) and the other is circumstantial (sample zero). Methods: This work proposes a new methodology to fit zero inflated Bernoulli data from a Bayesian approach, able to distinguish between two potential sources of zeros (structural and non-structural). Results: The proposed methodology performance has been evaluated through a comprehensive simulation study, and it has been compiled as an R package freely available to the community. Its usage is illustrated by means of a real example from the field of occupational health as the phenomenon of sickness presenteeism, in which it is reasonable to think that some individuals will never be at risk of suffering it because they have not been sick in the period of study (structural zeros). Without separating structural and non-structural zeros one would be studying jointly the general health status and the presenteeism itself, and therefore obtaining potentially biased estimates as the phenomenon is being implicitly underestimated by diluting it into the general health status. Conclusions: The proposed methodology is able to distinguish two different sources of zeros (structural and non-structural) from dichotomous data with or without covariates in a Bayesian framework, and has been made available to any interested researcher in the form of the bayesZIB R package (https://cran.r-project.org/package=bayesZIB)

Real-time discrimination of photon pairs using machine learning at the LHC

ALP-mediated decays and other as-yet unobserved B decays to di-photon final states are a challenge to select in hadron collider environments due to the large backgrounds that come directly from the p p collision. We present the strategy implemented by the LHCb experiment in 2018 to efficiently select such photon pairs. A fast neural network topology, implemented in the LHCb real-time selection framework achieves high efficiency across a mass range of 4−20 GeV/c2. We discuss implications and future prospects for the LHCb experimentS

Cortical fracturing inferred from active and passive seismicity techniques: Neogene extension in the "forebulge" of the Guadalquivir Basin

La aplicación de técnicas de sismicidad pasiva y activa ha permitido observar variaciones en la frecuencia fundamental del suelo en una transversal a los estuarios Odiel y Tinto (Huelva). Los valores más bajos (0,27-0,29 Hz) están en el extremo oriental de la transversal, en las proximidades de Mazagón. Los valores más altos (0,83-1,06 Hz) se localizan en el extremo occidental de la transversal, al oeste del Odiel. El “basamento rocoso” (mecánico) es identificado como el techo del Complejo Basal Transgresivo (calizas neógenas). El zócalo paleozoico estará situado 10-20 metros por debajo de dichas calizas. Se interpreta que fallas extensionales NNE-SSO acomodan la extensión de la corteza terrestre durante el Neógeno en relación con el “forebulge” de la Cuenca del GuadalquivirThe application of passive and active seismicity techniques has allowed us to observe variations in the fundamental frequency of the soil in a transversal in the estuaries Odiel and Tinto (Huelva). The lowest values (0.27-0.29 Hz) are at the eastern end of the transversal, near Mazagón. The highest values (0.83-1.06 Hz) are located at the western end of the transversal, west of Odiel. The “rocky basement” (mechanical) is identified as the roof of the transgressive basal complex (limestones of Neogene age). The Paleozoic basement will be located 10-20 meters below these limestones. It is interpreted that NNE-SSO extensional faults accommodate the extension of the earth’s crust during the Neogen in relation to the “forebulge” of the Guadalquivir Basi

Neuron-derived extracellular vesicles contain synaptic proteins, promote spine formation, activate TrkB-mediated signalling and preserve neuronal complexity

Extracellular vesicles (EVs) play an important role in intercellular communication as carriers of signalling molecules such as bioactive miRNAs, proteins and lipids. EVs are key players in the functioning of the central nervous system (CNS) by influencing synaptic events and modulating recipient neurons. However, the specific role of neuron-to-neuron communication via EVs is still not well understood. Here, we provide evidence that primary neurons uptake neuron-derived EVs in the soma, dendrites, and even in the dendritic spines, and carry synaptic proteins. Neuron-derived EVs increased spine density and promoted the phosphorylation of Akt and ribosomal protein S6 (RPS6), via TrkB-signalling, without impairing the neuronal network activity. Strikingly, EVs exerted a trophic effect on challenged nutrient-deprived neurons. Altogether, our results place EVs in the spotlight for synaptic plasticity modulation as well as a possible therapeutic tool to fight neurodegeneration

Measurement of relative branching fractions of B decays to ψ(2S) and J/ψ mesons

The relative rates of B-meson decays into J/ψ and ψ(2S) mesons are measured for the three decay modes in pp collisions recorded with the LHCb detector. The ratios of branching fractions ( B) are measured to be where the third uncertainty is from the ratio of the ψ(2S) and J/ψ branching fractions to μ + μ −

Cirurgia Endoscòpica i Laparoscòpica combinada per al tractament de pòlips colònics benignes complexos

La cirurgia endoscòpica i laparoscòpica combinada (CELS) s'ha desenvolupat extraordinàriament en els últims 10-15 anys com una alternativa mínimament invasiva a la resecció quirúrgica de còlon per al tractament de pòlips benignes. Aquest estudi mostra algunes de les tècniques més utilitzades i n'avalua la viabilitat, la seguretat i els resultats a curt termini en els primers 15 pacients intervinguts a l'Hospital Parc Taulí, un dels primers centres a introduir aquesta tècnica a Espanya.La cirugía endoscópica y laparoscópica combinada (CELS) se ha desarrollado extraordinariamente en los últimos 10-15 años como una alternativa mínimamente invasiva a la resección quirúrgica de colon para el tratamiento de pólipos benignos. Este estudio muestra algunas de las técnicas más utilizadas y evalúa la viabilidad, la seguridad y los resultados a corto plazo en los primeros 15 pacientes intervenidos en el Hospital Parc Taulí, uno de los primeros centros en introducir esta técnica en España

Nuclear energy in the public sphere: Anti-nuclear movements vs. industrial lobbies in Spain (1962-1979)

The final publication is available at Springer via http://dx.doi.org/10.1007/s11024-014-9263-0This article examines the role of the Spanish Atomic Forum as the representative of the nuclear sector in the public arena during the golden years of the nuclear power industry from the 1960s to 1970s. It focuses on the public image concerns of the Spanish nuclear lobby and the subsequent information campaigns launched during the late 1970s to counteract demonstrations by the growing and heterogeneous anti-nuclear movement. The role of advocacy of nuclear energy by the Atomic Forum was similar to that in other countries, but the situation in Spain had some distinguishing features. Anti-nuclear protest in Spain peaked in 1978 paralleling the debates of a new National Energy Plan in Congress, whose first draft had envisaged a massive nuclearization of the country. We show how the approval of the Plan in July 1979, with a significant reduction in the nuclear energy component, was influenced by the anti-nuclear protest movements in Spain. Despite the efforts of the Spanish Atomic Forum to counter its message, the anti-nuclear movement was strengthened by reactions to the Three Mile Island accident in March 1979