The Network Picture of Labor Flow

We construct a data-driven model of flows in graphs that captures the essential elements of the movement of workers between jobs in the companies (firms) of entire economic systems such as countries. The model is based on the observation that certain job transitions between firms are often repeated over time, showing persistent behavior, and suggesting the construction of static graphs to act as the scaffolding for job mobility. Individuals in the job market (the workforce) are modelled by a discrete-time random walk on graphs, where each individual at a node can possess two states: employed or unemployed, and the rates of becoming unemployed and of finding a new job are node dependent parameters. We calculate the steady state solution of the model and compare it to extensive micro-datasets for Mexico and Finland, comprised of hundreds of thousands of firms and individuals. We find that our model possesses the correct behavior for the numbers of employed and unemployed individuals in these countries down to the level of individual firms. Our framework opens the door to a new approach to the analysis of labor mobility at high resolution, with the tantalizing potential for the development of full forecasting methods in the future.Comment: 27 pages, 6 figure

Frictional Unemployment on Labor Flow Networks

We develop an alternative theory to the aggregate matching function in which workers search for jobs through a network of firms: the labor flow network. The lack of an edge between two companies indicates the impossibility of labor flows between them due to high frictions. In equilibrium, firms' hiring behavior correlates through the network, generating highly disaggregated local unemployment. Hence, aggregation depends on the topology of the network in non-trivial ways. This theory provides new micro-foundations for the Beveridge curve, wage dispersion, and the employer-size premium. We apply our model to employer-employee matched records and find that network topologies with Pareto-distributed connections cause disproportionately large changes on aggregate unemployment under high labor supply elasticity

Morphometric differentiation in small juveniles of the pink spotted shrimp (Farfantepenaeus brasiliensis) and the southern pink shrimp (F. notialis) in the Yucatan Peninsula, Mexico

The morphometric and morphological characters of the rostrum have been widely used to identify penaeid shrimp species (Heales et al., 1985; Dall et al., 1990; Pendrey et al., 1999). In this setting, one of the constraints in studies of penaeid shrimp populations has been the uncertainty in the identification of early life history stages, especially in coastal nursery habitats, where recruits and juveniles dominate the population (Dall et al., 1990; Pérez-Castañeda and Defeo, 2001). In the western Atlantic Ocean, Pérez-Farfante (1969, 1970, 1971a) described diagnostic characters of the genus Farfantepenaeus that allowed identification of individuals in the range of 8−20 mm CL (carapace length) on the basis of the following morphological features: 1) changes in the structure of the petasma and thelycum; 2) absence or presence of distomarginal spines in the ventral costa of the petasma; 3) the ratio between the keel height and the sulcus width of the sixth abdominal somite; 4) the shape and position of the rostrum with respect to the segments and flagellum of the antennule; and 5) the ratio between rostrum length (RL) and carapace length (RL/CL). In addition, she classified Farfantepenaeus into two groups according to the shape and position of the rostrum with respect to the segments and flagellum of the antennule and the ratio RL/CL: 1) F. duorarum and F. notialis: short rostrum, straight distally, and the proximodorsal margin convex, usually extending anteriorly to the end of distal antennular segment, sometimes reaching to proximal one-fourth of broadened portion of lateral antennular flagellum, with RL/CL 0.80. Pérez-Farfante stressed that, for the recognition to species level of juveniles <10 mm CL, all the characters listed above should be considered because occasionally one alone may not prove to be diagnostic. However, the only characters that could be distinguished for small juveniles in the range 4−8 mm CL are those defined on the rostrum. Therefore, it has been almost impossible to identify and separate small specimens of Farfantepenaeus (Pérez-Farfante, 1970, 1971a; Pérez-Farfante and Kensley, 1997)

Cluster Galaxy Morphologies: The Relationship among Structural Parameters, Activity and the Environment

We use an approach to estimate galaxy morphologies based on an ellipticity (e) vs. Bulge-to-Total ratio (B/T) plane. We have calibrated this plane by comparing with Dressler's classifications. With the aid of our calibration, we have classified 635 galaxies in 18 Abell clusters (0.02 < z < 0.08). Our approach allowed us to recover the Kormendy's relation. We found that ellipticals and Spirals are slightly brighter than S0 in R band. As S0 bulges are brighter than spirals bulges, we believe that ram pressure is not the main mechanism to generate S0s. In our sample, cluster radio galaxies morphologies cover the range S0-E-cD and their bulges have absolutes magnitudes distributed within -21 mag < M < -24.5 mag. If we believe Ferrarese & Merrit's relation, these radio sources have 10^8-10^9 M black hole mass.Comment: Originally published in the proceedings of the conference "The Monster's Fiery Breath: Feedback in Galaxies, Groups, and Clusters", AIP Conference Proceedings, Volume 1201 edited by Sebastian Heinz and Eric Wilcots. This version contains slight modification

Valoración multicriterio de los recursos naturales de la Sierra Norte de Oaxaca

Positioned from the paradigm of post-normal science, multicriteria evaluation methods are considered the most appropriate for assessing environmental sustainability to consider the three basic dimensions of environmental sustainability: economic, ecological and social. In the present work, was calculated through a multicriteria methodology, the assessment of stakeholders of the Sierra Norte de Oaxaca make of their natural resources; so too, based on the assessments made, investigate about the possibilities of coalitions among stakeholders identified; to achieve these objectives NAIADE methodology was used. We found that regardless of the level of compensation between criteria, and the degree of credibility of the information, for the four identified social actors, the "without mining" is always preferred the stage "mining", that is, they are positioned in the paradigm of strong sustainability.Posicionados desde el paradigma de la ciencia postnormal, los métodos multicriterio se consideran como los más adecuados para valorar los recursos naturales al considerar las tres dimensiones básicas de la sustentabilidad ambiental: económica, ecológica y social. En el presente trabajo, se calculó a través de una metodología multicriterio, la valoración que diversos actores sociales de la Sierra Norte de Oaxaca hacen de sus recursos naturales; así también, con base en las valoraciones realizadas, se indagó sobre las posibilidades de coalición entre los actores identificados; para lograr estos objetivos se utilizó la metodología NAIADE. Se encontró que sin importar el nivel de compensación entre criterios, ni el grado de credibilidad de la información, para los cuatro actores sociales identificados, el escenario “sin la minería” siempre es preferido al escenario “con la minería”, es decir, están posicionados en el paradigma de la sustentabilidad fuerte

Abordaje diagnóstico, terapéutico y seguimiento de las lesiones pre malignas de Cérvix en pacientes de los Municipios del Departamento de Boaco, atendidas en el Hospital José Nieborowski en período correspondiente de Enero 2016-Mayo 2017

El presente estudio es descriptivo, retrospectivo de corte transversal, que se realizó en el Hospital José Nieborowski, en donde se atendieron 305 mujeres con lesiones de bajo grado de cervical en todo el año 2016 , de la cual se extrajo una muestra significativa de 90 pacientes procedentes de diferentes munición del departamento de Boaco, con el objetivo de la aplicación del siguiente tema Abordaje diagnóstico, terapéutico y seguimiento de las lesiones pre malignas de cérvix en pacientes de los municipios del departamento de Boaco, atendidas en el hospital José Nieborowsk en periodo correspondiente de Enero 2016 Mayo 2017. Obteniendo siguientes resultados Las pacientes en estudio son mujeres que predominaron de mayor de 35 años, estos resultados se relacionan, con los diferentes estudios, en donde comienzan a parecer las alteraciones histológicas de cérvix, pero sin embargo no podemos obviar que se encontró lesiones en mujeres en edad reproductiva, amas de casa, con educación secundaria y primaria y de procedencia urbana. Entre los factores asociados de las pacientes estudiadas se encontró que el nivel de escolaridad baja, inicio de vida sexual a temprana edad más de un compañero sexual, el uso de anticonceptivos hormonales, la multiparidad, Como método de tamizaje se utilizó el PAP y de diagnóstico la biopsia cervical, encontrando que las lesiones más frecuentes son las de bajo grado como lo es el NIC1, seguidas por las de alto grado. Las lesiones de bajo grado VPH se les dio seguimiento citológico evolucionaron con regresión espontanea, las lesiones NIC I fueron tratadas con crioterapia, las lesiones de alto grado (NIC II y NIC III) el tratamiento de elección ASA Térmica, y en algunos casos se realizó histerectomía según criterios médico

Quasinormal modes of the Schwarzchild black hole with a deficit solid angle and quintessence-like matter: Scalar and electromagnetic perturbations

We study the quasinormal modes (QNM) for scalar, and electromagnetic perturbations in the Schwarzchild black hole with a deficit solid angle and quintessence-like matter. Using the sixth--order WKB approximation and the improved asymptotic iteration method (AIM) we can determine the dependence of the quasinormal modes on the parameters of the black hole and the parameters on the test fields. The values of the real part and imaginary parts of the quasi--normal modes increase with the decrease of the values of the deficit solid angle and density of quintessence-like matter. The quasinormal modes gotten by these two methods are in good agreement. Using the finite difference method, we obtain the time evolution profile of such perturbations in this Black Hole