Active Sums I

Given a generating family F of subgroups of a group G, closed under conjugation and with partial order compatible with inclusion, a new group S can be constructed, taking into account the multiplication in the subgroups and their mutual actions given by conjugation. The group S is called the active sum of F, has G as a homomorph and is such that S/Z(S) ' G/Z(G), where Z denotes the center. The basic question we investigate in this paper is: when is the active sum S of the family F isomorphic to the group G? The conditions found to answer this question are often of a homological nature. We show that the following groups are active sums of cyclic subgroups: free groups, semidirect products of cyclic groups, Coxeter groups, Wirtinger approximations, groups of order p3 with p an odd prime, simple groups with trivial Schur multiplier, and special linear groups SLn(q) with a few exceptions. We show as well that every finite group G such that G/G0 is not cyclic is the active sum of proper normal subgroups

Sistema empotrado de reconocimiento de voz sobre FPGA

Comunicación presentada al "Iberchip XVIII Workshop " celebrado en Playa del Carmen (México) del 29 de Febrero al 2 de Marzo del 2012En esta comunicación se presenta un sistema empotrado sobre FPGA de reconocimiento de voz que aplica el algoritmo LPC (Linear Predictive Coding). El sistema está basado en el procesador MicroBlaze de Xilinx. Se describe el desarrollo del sistema desde la implementación del controlador del códec de audio (tanto el hardware como el desarrollo de los drivers) hasta la adaptación del algoritmo LPC a los requerimientos de la arquitectura hardware.Unión Europea MOBY-DIC Project FP7- IST-248858Ministerio de Ciencia y Tecnología (España) TEC2008-04920 TEC2011-24319Junta de Andalucía P08-TIC-03674Fondos FEDER P08-TIC-0367

Ocean-floor sediments as a resource of rare earth elements: an overview of recently studied sites

The rare earth elements (REE), comprising 15 elements of the lanthanum series (La-Lu) together with yttrium (Y) and scandium (Sc), have become of particular interest because of their use, for example, in modern communications, renewable energy generation, and the electrification of transport. However, the security of supply of REE is considered to be at risk due to the limited number of sources, with dependence largely on one supplier that produced approximately 63% of all REE in 2019. As a result, there is a growing need to diversify supply. This has resulted in the drive to seek new resources elsewhere, and particularly on the deep-ocean floor. Here, we give a summary of REE distribution in minerals, versatile applications, and an update of their economic value. We present the most typical onshore methods for the determination of REE and examine methods for their offshore exploration in near real time. The motivation for this comes from recent studies over the past decade that showed ΣREE concentrations as high as 22,000 ppm in ocean-floor sediments in the Pacific Ocean. The ocean-floor sediments are evaluated in terms of their potential as resources of REE, while the likely economic cost and environmental impacts of deep-sea mining these are also considered

Sensor de humedad del suelo de bajo coste para control de regadíos

This paper presents a low-cost system to measure soil humidity for application in irrigation control. It is based in the simultaneous measurement of the real and imaginary parts of the impedance of a volume of soil comprised between two conducting electrodes. The separation of real and imaginary parts allows for an accurate measurement of water contents even in soils with high salinity. An ASIC is being developed which acts as interface between a capacitive probe and a microcontroller. Satisfactory laboratory tests have been completed on a first prototype. The system will be used to reduce the water consumption in agriculture by determining the optimum volume of water to use.Se presenta un sistema de medida de humedad del suelo para aplicaciones en el control de riegos. Basado en la medida de las componentes real e imaginaria de la impedancia presentada por el volumen de suelo comprendido entre dos electrodos, permite determinar de forma fiable el contenido de humedad incluso en suelos salinos. Se está desarrollando un ASIC que actúa como interfase entre una sonda capacitiva y un microcontrolador y se han completado las pruebas de laboratorio sobre un primer prototipo. El sistema será empleado como medidor de humedad de suelo para regadíos, al objeto de decidir el momento y volumen de agua óptimo a emplear en cada turno de riego, minimizando así el consumo de agua.Fondo Europeo para el Desarrollo Regional (FEDER)Programa Nacional de Tecnologías de Información y las Comunicaciones I+

Isolation of Human Colon Stem Cells Using Surface Expression of PTK7

SummaryInsertion of reporter cassettes into the Lgr5 locus has enabled the characterization of mouse intestinal stem cells (ISCs). However, low cell surface abundance of LGR5 protein and lack of high-affinity anti-LGR5 antibodies represent a roadblock to efficiently isolate human colonic stem cells (hCoSCs). We set out to identify stem cell markers that would allow for purification of hCoSCs. In an unbiased approach, membrane-enriched protein fractions derived from in vitro human colonic organoids were analyzed by quantitative mass spectrometry. Protein tyrosine pseudokinase PTK7 specified a cell population within human colonic organoids characterized by highest self-renewal and re-seeding capacity. Antibodies recognizing the extracellular domain of PTK7 allowed us to isolate and expand hCoSCs directly from patient-derived mucosa samples. Human PTK7+ cells display features of canonical Lgr5+ ISCs and include a fraction of cells that undergo differentiation toward enteroendocrine lineage that resemble crypt label retaining cells (LRCs)

Isolation of Human Colon Stem Cells Using Surface Expression of PTK7.

Insertion of reporter cassettes into the Lgr5 locus has enabled the characterization of mouse intestinal stem cells (ISCs). However, low cell surface abundance of LGR5 protein and lack of high-affinity anti-LGR5 antibodies represent a roadblock to efficiently isolate human colonic stem cells (hCoSCs). We set out to identify stem cell markers that would allow for purification of hCoSCs. In an unbiased approach, membrane-enriched protein fractions derived from in vitro human colonic organoids were analyzed by quantitative mass spectrometry. Protein tyrosine pseudokinase PTK7 specified a cell population within human colonic organoids characterized by highest self-renewal and re-seeding capacity. Antibodies recognizing the extracellular domain of PTK7 allowed us to isolate and expand hCoSCs directly from patient-derived mucosa samples. Human PTK7+ cells display features of canonical Lgr5+ ISCs and include a fraction of cells that undergo differentiation toward enteroendocrine lineage that resemble crypt label retaining cells (LRCs)

Exposure to Mixtures of Pollutants in Mexican Children from Marginalized Urban Areas

Background: Exposure to contaminant mixtures in developing countries is an important public health issue. Children are identified as the most susceptible group to adverse health effects due to the exposure. Objective: The aim of this study was to conduct a screening for mixture pollutants in Mexican children in urban marginalized communities. Methods: We analyzed children (aged 6–12 years old) who resided in four urban marginalized communities in San Luis Potosi, Mexico: i) Bellas Lomas (BEL), a site with vehicular traffic; ii) Tercera Chica (TC), a site with brick kilns; Iii) Rincon de San Jose (SJR), a site with a hazardous waste landfill; and (iv) Morales (MOR) a metallurgical zone with copper-arsenic and electrolytic zinc smelters. Polycyclic Aromatic Hydrocarbons (1-hydroxypyrene (1-OHP)), benzene (trans, trans-muconic acid (t,t-MA), manganese, arsenic and fluoride were quantified in urine and lead in blood samples. Findings: Our results indicate that median exposures to manganese were 4.4, 5.2, 5.8 and 6.3 μg/L for BEL, TC, SJR and MOR, respectively. For BEL, fluoride was present at a higher concentration with 2.3 mg/L followed by MOR, TC and SJR with 1.7, 1.5 and 1.2 mg/L respectively. The highest concentrations of arsenic that were found were 11 μg/L in MOR and lead concentration was reported between 4.2 and 6.8 μg/dL, in BEL, TC and MOR. 1-OHP and t,t-MA were higher in TC (0.23 μmol/mol creatinine (cr), 429.7 μg/g cr, respectively) followed by SJR (0.09 μmol/mol cr, 427.4 μg/g cr), MOR (0.03 μmol/mol cr, 258.6 μg/g cr) and BEL (0.06 μmol/mol cr, 220.6 μg/g cr). Conclusion: Considering the large number of people, especially children, exposed to multiple pollutants, it is important to design effective intervention programs that reduce exposure and the resultant risk in the numerous urban marginalized communities in Mexico

A study of the dry forest communities in the Dominican Republic

This paper is a floristic and phytosociological study of the dry forest communities of the Dominican Republic. A total of 69 relevés in dry forest biotopes were carried out. The samples were subsequently subjected to Detrended Correspondence Analysis for the determination and study of possible groupings. The study does not cover tree formations growing on serpentines, nor the so-called semideciduous forests, peculiar to areas with higher rainfall. A total of nine phytocoenoses were identified. The most significant results led to the description of six new phytosociological associations: Simaroubetum berteroani (thorny dry forest on coastal dunes), Phyllostylo rhamnoidis-Prosopidetum juliflorae (southern Dominican disturbed dry forest), Consoleo moniliformis-Camerarietum linearifoliae (dry forest on hard limestones), Lemaireocereo hystricis-Prosopidetum juliflorae (northern Dominican disturbed dry forest), Lycio americani-Prosopidetum juliflorae (disturbed dry forest on saline soils) and Guettardo ellipticae-Guapiretum discoloris (dry forest on flat-topped hillocks in Montecristi). This is an important step forward in the phytosociological and floristic studies of the Caribbean territories.Este trabalho apresenta um estudo florístico e fitossociológico das comunidades de florestas secas da República Dominicana. Um total de 69 amostras foram obtidas pelo método relevé em biótopos florestais secos. As amostras foram posteriormente submetidas à análise de correspondência destendenciada para a determinação e estudo de possíveis agrupamentos. O estudo não abrange formações arbóreas desenvolvidas sobre serpentinitos, nem as chamadas florestas semideciduais, peculiares às áreas de maior pluviosidade. Foram identificados nove fitocenoses. Os resultados mais significativos levaram à descrição de seis novas associações fitossociológicas: Simaroubetum berteroani (floresta espinhosa seca em dunas costeiras), Phyllostylo rhamnoidis-Prosopidetum juliflorae (floresta seca perturbada do sul da República Dominicana), Consoleo moniliformis-Camerarietum linearifoliae (floresta seca sobre calcários compactos), Lemaireocereo hystricis-Prosopidetum juliflorae (floresta seca perturbada do norte da República Dominicana), Lycio americani-Prosopidetum juliflorae (floresta seca perturbada desenvolvida em solos salinos) Guettardo ellipticae-Guapiretum discoloris (floresta seca em colinas de topo achatado em Montecristi). O trabalho realizado representa um importante avanço nos estudos fitossociológicos e florísticos dos territórios do Caribe.This research paper was possible thanks to the sponsorship of the Agencia Española de Cooperación Internacional para el Desarrollo (AECID), under the auspices of the Ministerio de Asuntos Exteriores y de Cooperación de España, which funded the project (cod. A/3499/05)

Sistema empotrado de reconocimiento de voz sobre FPGA

Comunicación presentada al "Iberchip XVIII Workshop " celebrado en Playa del Carmen (México) del 29 de Febrero al 2 de Marzo del 2012.En esta comunicación se presenta un sistema empotrado sobre FPGA de reconocimiento de voz que aplica el algoritmo LPC (Linear Predictive Coding). El sistema está basado en el procesador MicroBlaze de Xilinx. Se describe el desarrollo del sistema desde la implementación del controlador del códec de audio (tanto el hardware como el desarrollo de los drivers) hasta la adaptación del algoritmo LPC a los requerimientos de la arquitectura hardware.Este trabajo ha sido soportado parcialmente por el proyecto financiado por la Unión Europea MOBY-DIC Project FP7-IST-248858, por el Ministerio de Ciencia y Tecnología bajo el proyecto TEC2008-04920 y TEC2011-24319 con cofinanciación FEDER y por la Junta de Andalucía bajo el proyecto P08-TIC-03674.Peer Reviewe