El metro de la ciudad de México. Desarrollo y perspectivas

Hoy en día, el Sistema de Transporte Colectivo Metro(STC)cuenta con 8 líneas, 141 kilómetros y 125 estaciones en servicio. Cada día mueve alrededor de 5 millones de pasajeros. Probablemente sea el más grande de los metros en el Tercer Mundo y su red es tan extensa como la de todos los metros en operación en América Latina, juntos. lA renegociación de la deuda externa, el inicio del saneamiento de las finanzas del Departamento del Distrito Federal y, particularmente el incremento de la tarifa del Metro, allanaron en principio, el obstáculo financiero

Un nou llistonar (Teucrio muletii-Brachypodietum retusi ass. nova) per a la província de Castelló (Espanya)

Es proposa un nou llistonar (Teucrio muletii-Brachypodietum retusi) pertanyent a l’aliança Teucrio pseudochamaepityos-Brachypodion retusi (classe Lygeo-Stipetea), emplaçada al Paratge Natural del Desert de les Palmes (Castelló, Espanya).A new association of perennial xerophytic grassland (Teucrio muletii-Brachypodietum retusi) belonging to the alliance Teucrio pseudochamaepityos-Brachypodion retusi (Lygeo-Stipetea class) is proposed, occurring in the Natural Park Desert de les Palmes (Castellón, Spain)

Tipificación de Statice dichotoma Cav. (Plumbaginaceae)

A lectotype and an epitype are here designated for Statice dichotoma Cav. (Plumbaginaceae), an endemic taxon from the central part of the Iberian Peninsula, which is currently named Limonium dichotomum (Cav.) Kuntze.Se designan un lectótipo y un epítipo para Statice dichotoma Cav. (Plumbaginaceae), un taxon endémico del centro de la península Ibérica, actualmente denominado Limonium dichotomum (Cav.) Kuntze

Artificial intelligence in wind speed forecasting: a review

Wind energy production has had accelerated growth in recent years, reaching an annual increase of 17% in 2021. Wind speed plays a crucial role in the stability required for power grid operation. However, wind intermittency makes accurate forecasting a complicated process. Implementing new technologies has allowed the development of hybrid models and techniques, improving wind speed forecasting accuracy. Additionally, statistical and artificial intelligence methods, especially artificial neural networks, have been applied to enhance the results. However, there is a concern about identifying the main factors influencing the forecasting process and providing a basis for estimation with artificial neural network models. This paper reviews and classifies the forecasting models used in recent years according to the input model type, the pre-processing and post-processing technique, the artificial neural network model, the prediction horizon, the steps ahead number, and the evaluation metric. The research results indicate that artificial neural network (ANN)-based models can provide accurate wind forecasting and essential information about the specific location of potential wind use for a power plant by understanding the future wind speed values

Taxonomical and nomenclatural notes in the genus Cheirolophus Cass. (Asteraceae, Centaureinae)

Es lectotipifica i es reivindica el valor taxonòmic de Cheirolophus cavanillesianus nomo nov. [Centaurea virgata Cav., sinònim reemplaçat, syn. subst.) (Asteraceae, Centaureinae), espècie descrita per A. J. Cavanilles el 1795 per a la província d'Alacant. Dins d'aquest taxon, incloem a nivell subespecífic la varietat capillifolius [Ch. cavanillesianus subsp. capillifolius, combo & stat. nov.), taxon indicat per a diverses localitats de la província d'Alacant. Així mateix, es realitza la lectotipificació de Ch. intybaceus (Lam.) Dostál.We propose the lectotypification as well as the taxonomic value for Cheirolophus cavanillesianus nomo nov. [Centaurea virgata Cav., replaced synonym, syn. subst.) (Asteraceae, Centaureinae), a plant species described by A. J. Cavanilles in 1795 for the province of Alicante. Within this taxon we raise up to the subspecies level the variety capillifolius [Ch. cavanillesianus subsp. capillifolius, combo & stat. nov.), taxa indicated for sorne populations of the Alicante coast. Moreover, Ch. intybaceus (Lam.) Dostál has also been lectotypified

A new terophytic grassland association (Polycarpo diphylli-Psiluretum incurvi, ass. nova) from Serra d'Espadà and surroundings is proposed (Castelló, Spain)

Es proposa un nou pradell terofític, l'associació Polycarpo diphylli-Psiluretum incurvi R. Roselló, J. R, Vázquez, P. P. Ferrer, E. Laguna, Gómez Nav. & J. B. Peris, pertanyent a l'aliança Brachypodietalia distachyi (classe Tuberarietea guttatae), emplaçat al Parc Natural de la Serra d'Espadà i els seus voltants (Castelló, Espanya).A new terophytic grassland association Polycarpo diphylli-Psiluretum incurvi R. Roselló, J. R. Vázquez, P. P. Ferrer, E. Laguna, Gómez Nav. & J. B. Peris, belonging to the alliance Brachypodietalia distachyi (Tuberarietea guttatae class) is proposed, occurring in the Natural Park Serra d'Espadà and its surroundings (Castellón, Spain)

Momento Económico (49)

En este número: "¿Una nueva acumulación originaria?". "El Metro de la Ciudad de México. Desarrollo y perspectivas". "La agonía del Estado empresario". Sección de Indicadores Económicos. "Las 'zonas de producción libre' en la 'restructuración' de la economía mundial". "Estados Unidos: hegemonía en crisis". Sección de América Latina. Temas de Hoy

Long-Term Carbon Sequestration in Pine Forests under Different Silvicultural and Climatic Regimes in Spain

Proactive silviculture treatments (e.g., thinning) may increase C sequestration contributing to climate change mitigation, although, there are still questions about this effect in Mediterranean pine forests. The aim of this research was to quantify the storage of biomass and soil organic carbon in Pinus forests along a climatic gradient from North to South of the Iberian Peninsula. Nine experimental Pinus spp trials were selected along a latitudinal gradient from the pre-Pyrenees to southern Spain. At each location, a homogeneous area was used as the operational scale, and three thinning intensity treatments: unthinned or control (C), intermediate thinning (LT, removal of 30–40% of the initial basal area) and heavy thinning (HT, removal of 50–60%) were conducted. Growth per unit area (e.g., expressed as basal area increment-BAI), biomass, and Soil Organic Carbon (SOC) were measured as well as three sets of environmental variables (climate, soil water availability and soil chemical and physical characteristics). One-way ANOVA and Structural Equation Modelling (SEM) were used to study the effect of thinning and environmental variables on C sequestration. Biomass and growth per unit area were higher in the control than in the thinning treatments, although differences were only significant for P. halepensis. Radial growth recovered after thinning in all species, but it was faster in the HT treatments. Soil organic carbon (SOC10, 0–10 cm depth) was higher in the HT treatments for P. halepensis and P. sylvestris, but not for P. nigra. SEM showed that Pinus stands of the studied species were beneficed by HT thinning, recovering their growth quickly. The resulting model explained 72% of the variation in SOC10 content, and 89% of the variation in silvicultural condition (basal area and density) after thinning. SOC10 was better related to climate than to silvicultural treatments. On the other hand, soil chemical and physical characteristics did not show significant influence over SOC10- Soil water availability was the latent variable with the highest influence over SOC10. This work is a new contribution that shows the need for forest managers to integrate silviculture and C sequestration in Mediterranean pine plantations