Frequency map analysis of a three-dimensional particle in the core model of a high intensity linac

We consider the dynamical properties of a particle-core model for a uniformly filled triaxial ellipsoid in a periodic lattice of a high intensity linac. The mismatched oscillation modes are analytically computed in the smooth approximation and are compared with the numerical results of a tracking program. The study of the phase space in the mismatched case is performed by the frequency map analysis. In particular, we can analyze the effect of the nonlinear resonances between the envelope modes and the single particle sincrobetatron frequencies. A chaoticity criterion based on the frequency map analysis allows one to compute the stability region around the beam core. An estimate of the transport and its enhancement due to mismatch is provided by tracking orbits at the border of the stability region

Economic Uncertainty and Fertility in Europe: Narratives of the Future

Background: In the last decade fertility rates have declined in most European countries, and explanations have tended to focus on the rise of economic uncertainty after the Great Recession. The empirical demographic tradition operationalized the forces of economic uncertainty through objective indicators of individuals’ labor market situation; for example, holding a temporary contract or being unemployed. However, contemporary European fertility trends are not comprehensively captured by these traditional indicators and statistical models, because fertility decisions are not a mere “statistical shadow of the past”. Objective: We propose a novel framework on economic uncertainty and fertility. This framework proffers that the conceptualization and operationalization of economic uncertainty needs to take into account that people use works of imagination, producing their own “narrative of the future” – namely, imagined futures embedded in social elements and their interactions. Narratives of the future allow people to act according to or in spite of the uncertainty they face, irrespective of structural constraints and their subjective perceptions. Contribution: In this reflection we suggest that the focus of contemporary fertility studies should partly shift to assessing how people build their narratives of the future. To this end, we propose several methodological strategies to empirically assess the role of narratives for fertility decisions. Future studies should also take into account that personal narratives are shaped by the “shared narratives” produced by several agents of socialization, such as parents and peers, as well as by the narratives produced by the media and other powerful opinion formers

Frailness and resilience of gene networks predicted by detection of co-occurring mutations via a stochastic perturbative approach

In recent years complex networks have been identified as powerful mathematical frameworks for the adequate modeling of many applied problems in disparate research fields. Assuming a Master Equation (ME) modeling the exchange of information within the network, we set up a perturbative approach in order to investigate how node alterations impact on the network information flow. The main assumption of the perturbed ME (pME) model is that the simultaneous presence of multiple node alterations causes more or less intense network frailties depending on the specific features of the perturbation. In this perspective the collective behavior of a set of molecular alterations on a gene network is a particularly adapt scenario for a first application of the proposed method, since most diseases are neither related to a single mutation nor to an established set of molecular alterations. Therefore, after characterizing the method numerically, we applied as a proof of principle the pME approach to breast cancer (BC) somatic mutation data downloaded from Cancer Genome Atlas (TCGA) database. For each patient we measured the network frailness of over 90 significant subnetworks of the protein-protein interaction network, where each perturbation was defined by patient-specific somatic mutations. Interestingly the frailness measures depend on the position of the alterations on the gene network more than on their amount, unlike most traditional enrichment scores. In particular low-degree mutations play an important role in causing high frailness measures. The potential applicability of the proposed method is wide and suggests future development in the control theory context

Stochastic Properties of Colliding Hard Spheres in a Non-equilibrium Thermal Bath

We consider the problem of describing the dynamics of a test particle moving in a thermal bath using the stochastic differential equations. We briefly recall the stochastic approach to the Brownian based on the statistical properties of collision theory for a gas of elastic particles and the molecular chaos hypothesis. The mathematical formulation of the Brownian motion leads to the formulation of the Ornstein-Uhlenbeck equation that provides a stationary solution consistent with the Maxwell-Boltzmann distribution. According to the stochastic thermodynamics, we assume that the stochastic differential equations allow to describe the transient states of the test particle dynamics in a thermal bath and it extends their application to the study of the non-equilibrium statistical physics. Then we consider the problem of the dynamics of a test massive particle in a non homogeneous thermal bath where a gradient of temperature is present. We discuss as the existence of a local thermodynamics equilibrium is consistent with a Stratonovich interpretation of the stochastic differential equations with a multiplicative noise. The stochastic model applied to the test particle dynamics implies the existence of a long transient state during which the particle shows a net drift toward the cold region of the system. This effect recalls the thermophoresis phenomenon performed by large molecule in a solution in response to a macroscopic temperature gradient and it can be explained as an effect of the non-locality character of the collision interactions between the test particle and the thermal bath particles. To validate the stochastic model assumptions we analyze the simulation results of the 2-dimensional hard sphere gas obtained by using an event-based computer code, that solves exactly the sphere dynamics. The temperature gradient is simulated by the presence of two reflecting boundary conditions at different temperature. The simulations suggest that existence of a local thermodynamic equilibrium is justified and highlight the presence of a drift in the average dynamics of an ensemble of massive particles. The results of the paper could be relevant for the applications of stochastic dynamical systems to the non-equilibrium statistical physics that is a key issue for the Complex Systems Physics

Zonas de reserva campesina: territorios de paz en disputa

El desarrollo rural es quizás uno de los campos más amplios de la agroecología, que en Colombia hace referencia a la conflictividad social y armada emanada de la lucha por la tierra. Este tema ha tomado importancia al interior de la Agenda de Negociación de los diálogos de paz entre el Gobierno Nacional y las FARC-EP. Sin embargo, hace ya décadas que se vienen desarrollando y documentando experiencias alrededor del tema, algunos, de gran importancia y común a escenarios académicos y políticos, son aquellos que tienen que ver con la colonización campesina, particularmente con las Zonas de Reserva Campesina (ZRC), las cuales, consagradas en Ley 160 de 1994 son una propuesta de las comunidades campesinas como una figura de ordenamiento territorial, nacido en un contexto histórico de luchas agrarias desde mediados del siglo XIX en zonas de colonización. Hoy en día estas son el centro de debate no solo por su naturaleza, sino por los alcances que poseen en la búsqueda de la paz.The rural development is maybe one of the largest issues of agroecology, in Colombia it involves the social and armed conkflict emanated by the war for lands. This topic has taken importance at the interior of the negotiation agenda of the peace dialogues between the national government and the “FARC-EP”. However, for decades it has been developing and documenting experiences around this topic, some of them of great importance and common to academic and politic stages, like those that deal with the peasant colonization, particularly with the peasant reserve zones “Zonas de Reserva Campesina (ZRC)”, that are consigned in the law 160 of 1994 and are a proposal of the peasant communities like a figure of zoning, started in a historic context of agrarian struggles since middle of XIX century at colonization zones. Nowadays this is the center of the debate, not only by its nature but by the scope that has on the search for peace.Eje A6: Desarrollo Rural, Movimientos Sociales, Estado y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Zonas de reserva campesina: territorios de paz en disputa

El desarrollo rural es quizás uno de los campos más amplios de la agroecología, que en Colombia hace referencia a la conflictividad social y armada emanada de la lucha por la tierra. Este tema ha tomado importancia al interior de la Agenda de Negociación de los diálogos de paz entre el Gobierno Nacional y las FARC-EP. Sin embargo, hace ya décadas que se vienen desarrollando y documentando experiencias alrededor del tema, algunos, de gran importancia y común a escenarios académicos y políticos, son aquellos que tienen que ver con la colonización campesina, particularmente con las Zonas de Reserva Campesina (ZRC), las cuales, consagradas en Ley 160 de 1994 son una propuesta de las comunidades campesinas como una figura de ordenamiento territorial, nacido en un contexto histórico de luchas agrarias desde mediados del siglo XIX en zonas de colonización. Hoy en día estas son el centro de debate no solo por su naturaleza, sino por los alcances que poseen en la búsqueda de la paz.The rural development is maybe one of the largest issues of agroecology, in Colombia it involves the social and armed conkflict emanated by the war for lands. This topic has taken importance at the interior of the negotiation agenda of the peace dialogues between the national government and the “FARC-EP”. However, for decades it has been developing and documenting experiences around this topic, some of them of great importance and common to academic and politic stages, like those that deal with the peasant colonization, particularly with the peasant reserve zones “Zonas de Reserva Campesina (ZRC)”, that are consigned in the law 160 of 1994 and are a proposal of the peasant communities like a figure of zoning, started in a historic context of agrarian struggles since middle of XIX century at colonization zones. Nowadays this is the center of the debate, not only by its nature but by the scope that has on the search for peace.Eje A6: Desarrollo Rural, Movimientos Sociales, Estado y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Gut microbiota ecology: Biodiversity estimated from hybrid neutral-niche model increases with health status and aging

In this work we propose an index to estimate the gut microbiota biodiversity using a modeling approach with the aim of describing its relationship with health and aging. The gut microbiota, a complex ecosystem that links nutrition and metabolism, has a pervasive effect on all body organs and systems, undergoes profound changes with age and life-style, and substantially contributes to the pathogenesis of age-related diseases. For these reasons, the gut microbiota is a suitable candidate for assessing and quantifying healthy aging, i.e. the capability of individuals to reach an advanced age, avoiding or postponing major age-related diseases. The importance of the gut microbiota in health and aging has been proven to be related not only to its taxonomic composition, but also to its ecological properties, namely its biodiversity. Following an ecological approach, here we intended to characterize the relationship between the gut microbiota biodiversity and healthy aging through the development a parsimonious model of gut microbiota from which biodiversity can be estimated. We analysed publicly available metagenomic data relative to subjects of different ages, countries, nutritional habits and health status and we showed that a hybrid niche-neutral model well describes the observed patterns of bacterial relative abundance. Moreover, starting from such ecological modeling, we derived an estimate of the gut microbiota biodiversity that is consistent with classical indices, while having a higher statistical power. This allowed us to unveil an increase of the gut microbiota biodiversity during aging and to provide a good predictor of health status in old age, dependent on life-style and aging disorders

Person Re-identification by Articulated Appearance Matching

Abstract Re-identification of pedestrians in video-surveillance settings can be ef-fectively approached by treating each human figure as an articulated body, whose pose is estimated through the framework of Pictorial Structures (PS). In this way, we can focus selectively on similarities between the appearance of body parts to recognize a previously seen individual. In fact, this strategy resembles what humans employ to solve the same task in the absence of facial details or other reliable bio-metric information. Based on these insights, we show how to perform single image re-identification by matching signatures coming from articulated appearances, and how to strengthen this process in multi-shot re-identification by using Custom Picto-rial Structures (CPS) to produce improved body localizations and appearance signa-tures. Moreover, we provide a complete and detailed breakdown of the system that surrounds these core procedures, with several novel arrangements devised for effi-ciency and flexibility. Finally, we test our approach on several public benchmarks, obtaining convincing results.