Estructura y composición florística de la vegetación secundaria en tres regiones de la sierra norte de Chiapas, México

El estado de Chiapas presenta una severa deforestación de los diferentes tipos de selvas, en la actualidad sólo quedan fragmentos de la vegetación original y con diferentes grados de sucesión, por lo que se planteó el objetivo de conocer la estructura y composición fl orística de la vegetación secundaria en tres regiones (valle, colina y ladera) de la Sierra Norte de Chiapas. La hipótesis de investigación fue que la estructura y composición fl orística arbórea es similar en las tres regiones. Todos los árboles de 2.5 cm de diámetro a la altura del pecho (DAP) fueron censados en cinco unidades de muestreo de 400 m² en cada región. Además se obtuvieron los índices de diversidad, similitud y valor de importancia. Se censó un total de 3 629 individuos en las tres regiones, contenidos en 43 familias, distribuidos en 104 géneros con 133 especies. La abundancia y número de especies fue mayor en la colina (114 especies) y menor en el valle (77 especies). Se distinguieron tres estratos; de los cuales, en el estrato bajo se concentró más del 80% de los individuos. Las especies más abundantes y con mayor Índice de valor de importancia (IVI) fueronLonchocarpus oliganthusySaurauia yasicaeen el valle y ladera, respectivamente, mientras queAstrocaryum mexicanumyBrosimum alicastrumdestacaron en la colina. La diversidad fue más alta en la colina (3.9) y similar en valle y ladera (3.7). Se encontró mayor semejanza fl orística entre colina y ladera (60%). Cada región presentó especies exclusivas comoSwartzia arborescensyPachira aquaticaen el valle,Simaruba glaucayGuarea grandifoliaen la colina, yCastilla elasticaen la ladera. En conclusión, la estructura y composición fl orística arbórea de la vegetación secundaria es diferente en tres regiones de la Sierra Norte de Chiapas

La diversificación económica de los pescadores de pequeña escala y sus contribuciones en los objetivos de la Agenda 2030

La pesca de pequeña escala es relevante. Sin embargo, aspectos como la sobrepesca, el crecimiento de la población humana, el estado de los stocks, influyen en la adopción de estrategias de diversificación económica por los pescadores. Este artículo investiga cómo evoluciona este proceso, identificando éxitos y desafíos, y sus contribuciones en los ODS de la Agenda 2030. Se realizó una revisión de alcance y análisis crítico de publicaciones del 2017 al 2022. Se encontró que el proceso de diversificación se gesta a nivel mundial, independientemente de las disimilitudes entre flotas. La diversificación muestra dos vías principales de evolución: en las actividades pesqueras y en actividades no pesqueras de acuerdo al patrimonio de cada región, destacando actividades turísticas, servicios de transporte, alimentos y acuicultura. La política pública, la capacitación y la integración del conocimiento académico se identifican como elementos de éxito, mientras que el control del mercado por mayoristas, sistemas de cuotas y una débil gobernanza destacan como desafíos. Se reconocen aportes importantes en seguridad alimentaria, reducción de pobreza y empleos dignos. No hay evidencia concluyente de sus impactos en ecosistemas sanos.The economic diversification of small-scale fishers and their contributions to the goals of the 2030 AgendaSmall-scale fishing is relevant. However, aspects such as overfishing, the human population growth, the state of the fishing stocks, influence the adoption of economic diversification strategies by fishers. This article investigates how this process evolves, identifying successes and challenges, and its contributions to the SDGs of the 2030 Agenda. A scope review and critical analysis of publications from 2017 to 2022 was carried out. It was found that the diversification process takes place worldwide, regardless of the differences between fleets. Diversification shows two main paths of evolution: in fishing activities and in non-fishing activities according to the heritage of each region, highlighting tourist activities, transportation services, food and aquaculture. Public policy, training and the integration of academic knowledge are identified as elements of success, while market control by wholesalers, quota systems and a weak governance stand out as challenges. Important contributions to food security, poverty reduction and decent jobs are recognized. There is no conclusive evidence of its impacts on healthy ecosystems

Tracing the assembly histories of galaxy clusters in the nearby universe

We have compiled a sample of 67 nearby ($z$ < 0.15) clusters of galaxies, for which on average more than 150 spectroscopic members are available, and, by applying different methods to detect substructures in their galaxy distribution, we have studied their assembly history. Our analysis confirms that substructures are present in 70% of our sample, having a significant dynamical impact in 57% of them. A classification of the assembly state of the clusters based on the dynamical significance of their substructures is proposed. In 19% of our clusters, the originally identified brightest cluster galaxy is not the central gravitationally dominant galaxy (CDG), but turns out to be either the second-rank, or the dominant galaxy of a substructure (a SDG, in our classification), or even a possible "fossil" galaxy in the periphery of the cluster. Moreover, no correlation was found in general between the projected offset of the CDG from the X-ray peak and its peculiar velocity. The comparison of the CDGs properties with the assembly states and dynamical state of the intracluster media, especially the core cooling status, suggests a complex assembly history, with clear evidence of co-evolution of the CDG and its host cluster in the innermost regions.Comment: Contains 33 pages, 12 figures, 8 tables. On the accompanying webpage ( http://www.astro.ugto.mx/recursos/HP_SCls/Top70.html ), we offer the complete set of figures describing all clusters presented in this articl

The ingestion of aflatoxigenic foods and their possible implications with cervical cancer

Cancer has been one of the most deadly diseases in the world; In the female population Cervical Cancer [CaCu], is one of the most frequent and deadly, which could be caused by different infectious, food, socioeconomic and cultural factors, to mention a few. Consuming aflatoxigenic foods such as [corn tortilla, almonds, rice, oats, peanuts, pistachios, among others] contaminated with Aspergillus parasiticus, A. nonius and A. flavus could pose a risk for CaCu. Objective. Determine the pattern of ingestion of aflatoxigenic foods in women diagnosed with [CaCu]. Material and methods. The study was observational cross-sectional. For this investigation, a study was carried out on 120 women; Persons who were previously selected according to a database provided by a health institution. Results. The results of the surveys show the high consumption of foods containing aflatoxins in patients diagnosed with Cervical-uterine Cancer. Conclusions. Women report high intakes of aflatoxigenic foods that may be involved in the development of [CaCu] and most likely with other epidemiological events. Failure to pay attention to patterns of food and poverty allows anticipating non-positive results in human health

La ganadería ante escenarios complejos.

La calidad de las contribuciones, producto de la pluma de especialistas en los temas tratados, el presente es un libro que esperamos, basándonos en la importancia de los temas tratados, sea de utilidad y abone a la reflexión de los estudiosos de la ganadería mexicana y, por supuesto, en beneficio de las familias ganaderas y de los consumidores de sus productos.este libro refleja en muchos sentidos la situación de la ganadería mexicana, a la que se le están demandando mayor producción y productividad, que los procesos productivos tengan la menor huella ecológicposible, que los alimentos sean inocuos, que se abatan costos de producción y, cada vez aumentan las presiones de diversos grupos para, que se incluyan los protocolos de bienestar animal, solamente por citar algunos de los retos que tiene. Algunas de estas demandas son complementarias, otras se contraponen, lo que hace valiosos a los estudios que desde las ciencias sociales se realizan y, desde diversas ópticas, se hagan propuestas de política pública balanceadas que consideren lo mejor de cada enfoque, pero sin desechar por completo los antagónicos.Universidad Autónoma Chaping

Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

Peer reviewe

An embedding technique to determine ττ backgrounds in proton-proton collision data

An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe

Measurement of the Splitting Function in &ITpp &ITand Pb-Pb Collisions at root&ITsNN&IT=5.02 TeV

Data from heavy ion collisions suggest that the evolution of a parton shower is modified by interactions with the color charges in the dense partonic medium created in these collisions, but it is not known where in the shower evolution the modifications occur. The momentum ratio of the two leading partons, resolved as subjets, provides information about the parton shower evolution. This substructure observable, known as the splitting function, reflects the process of a parton splitting into two other partons and has been measured for jets with transverse momentum between 140 and 500 GeV, in pp and PbPb collisions at a center-of-mass energy of 5.02 TeV per nucleon pair. In central PbPb collisions, the splitting function indicates a more unbalanced momentum ratio, compared to peripheral PbPb and pp collisions.. The measurements are compared to various predictions from event generators and analytical calculations.Peer reviewe

Measurement of nuclear modification factors of gamma(1S)), gamma(2S), and gamma(3S) mesons in PbPb collisions at root s(NN)=5.02 TeV

The cross sections for ϒ(1S), ϒ(2S), and ϒ(3S) production in lead-lead (PbPb) and proton-proton (pp) collisions at √sNN = 5.02 TeV have been measured using the CMS detector at the LHC. The nuclear modification factors, RAA, derived from the PbPb-to-pp ratio of yields for each state, are studied as functions of meson rapidity and transverse momentum, as well as PbPb collision centrality. The yields of all three states are found to be significantly suppressed, and compatible with a sequential ordering of the suppression, RAA(ϒ(1S)) > RAA(ϒ(2S)) > RAA(ϒ(3S)). The suppression of ϒ(1S) is larger than that seen at √sNN = 2.76 TeV, although the two are compatible within uncertainties. The upper limit on the RAA of ϒ(3S) integrated over pT, rapidity and centrality is 0.096 at 95% confidence level, which is the strongest suppression observed for a quarkonium state in heavy ion collisions to date. © 2019 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3.Peer reviewe

Electroweak production of two jets in association with a Z boson in proton-proton collisions root s =13 TeV

A measurement of the electroweak (EW) production of two jets in association with a Z boson in proton-proton collisions at root s = 13 TeV is presented, based on data recorded in 2016 by the CMS experiment at the LHC corresponding to an integrated luminosity of 35.9 fb(-1). The measurement is performed in the lljj final state with l including electrons and muons, and the jets j corresponding to the quarks produced in the hard interaction. The measured cross section in a kinematic region defined by invariant masses m(ll) > 50 GeV, m(jj) > 120 GeV, and transverse momenta P-Tj > 25 GeV is sigma(EW) (lljj) = 534 +/- 20 (stat) fb (syst) fb, in agreement with leading-order standard model predictions. The final state is also used to perform a search for anomalous trilinear gauge couplings. No evidence is found and limits on anomalous trilinear gauge couplings associated with dimension-six operators are given in the framework of an effective field theory. The corresponding 95% confidence level intervals are -2.6 <cwww/Lambda(2) <2.6 TeV-2 and -8.4 <cw/Lambda(2) <10.1 TeV-2. The additional jet activity of events in a signal-enriched region is also studied, and the measurements are in agreement with predictions.Peer reviewe