Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The occurrence of higher ground-level O3 concentrations on weekends rather than on weekdays, despite reduced anthropogenic activity in urban areas, is known as the O3 weekend effect (OWE). We present here an approach to analyse OWE spatio-temporal variations in urban areas, integrated by the trend, prediction and network representation. We used data from ten monitoring sites geographically distributed within the Mexico City Metropolitan Area (MCMA) recorded during 1994-2018. The OWE occurrence within the MCMA ranged typically between 40 and 60 % of the total weeks per year. The annual differences between weekday and weekend O3 peaks (magnitudes) showed were most significant on Sundays. Naive, Linear and Auto-regressive Integrated Moving Average models were tested for predicting the OWE annual occurrences and magnitudes. There was no single model that outperformed significantly for predicting OWE at all sites. The proposed concept of generalised OWE (GOWE) implies that at least half of the sites under study exhibited simultaneous OWE occurrence. GOWE is represented as a network and its integration with prediction models is useful to determine the OWE spread over the MCMA in the following years. The GOWE occurrence showed an increasing trend interpreted as the spread of VOC-limited conditions over most of the MCMA. Predicted data suggest that, with the current emission control policies, the GOWE will continue occurring. The integrated methodology presented provides valuable insight into the design of potential air quality control strategies.

Air pollution in towns adjacent to and downwind of large cities can be similar or even higher than in the city itself. In the case of towns constituting the greater Bogotá area, with more than half a million inhabitants and strong industrial activity, little is known about the factors that affect their poor air quality. This work investigated the incremental excess of the composition and source contribution to PM2.5 in two sites near Bogotá (Soacha: 4º35’4.59” N, 74º13’11.62” W; and Mosquera: 4º42’9.75” N, 74º13’54.94” W), using the Chemical Mass Balance receptor model with organic molecular markers, and back trajectory analysis. Simultaneous sample collection was carried out for two-months. Organic matter was the major component of the PM2.5 mass (66 ± 14% and 61 ± 12%), while secondary inorganic ions (sulfate, nitrate, and ammonium) constituted 13 ± 8 % and 10 ± 2 %. The main anthropogenic sources contributing to PM2.5 at Soacha were wood combustion (23%), diesel vehicles (19%), and coal combustion at small facilities (11%). At Mosquera, they were gasoline vehicles (26%), diesel vehicles (19%), and coal combustion at small inefficient facilities (15%). The contribution of regional secondary organic aerosol to PM2.5 was significant (19% and 15%), arriving mostly from the Orinoco basin but higher in air masses arriving from the Amazon rainforest. The regional contribution to secondary inorganic aerosols was higher with winds from the Magdalena Valley. The methods presented in this manuscript will be useful in other megacities and large cities to better manage impacts of local and regional air pollution sources.

The standardized precipitation evapotranspiration index (SPEI), calculated from 55 stations over the period 1961-2015, was used to analyze the spatial and temporal variability of the dry and wet climate in Xinjiang on a three and six-month time scale, so as to help to actively deal with the negative effects of climate change and reduce disaster losses. The obtained results show that precipitation and temperature in Xinjiang have an increasing trend, with rates of 8.90 mm and 0.39 ºC per decade, respectively. SPEI-3 and SPEI-6 show the same linear change trend, with a change rate of 0.005 and 0.007 per decade, respectively. Severe droughts occurred in 1997 and 2008, and particularly in 2008 considering SPEI-6, the number of meteorological stations with moderate drought and extreme drought accounted for 60 % of all stations. Analysis of Empirical Orthogonal Function (EOF) indicates that SPEI-3 and SPEI-6 have similar spatial distribution in the three EOF modes. EOF1 reflects that the overall dry and wet changes in the study area were weakening, and there was a drying trend; EOF2 was a reverse change in the northern and Southern Xinjiang; EOF3 shows that the East Tianshan had a drying trend, while the western part of Southern Xinjiang had a moistening trend. The spectra of wavelet coherence and cross wavelet transform showed that the SPEI values in Xinjiang have resonance periods of different time scales with the Atlantic Multidecadal Oscillation (AMO), El Nino Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), and Pacific Decadal oscillation (PDO), but shows differences in different time-domain correlations. Among them, AMO is the main atmospheric circulation factor that affects SPEI in the region.

Drought is a complex natural hazard that has numerous negative effects on ecosystems, agriculture, and the economy. For this reason, it is difficult to provide a precise definition. Nevertheless, different conceptualizations converge in one common denominator: the deficit of precipitation with respect to an average historical value. Droughts in Mexico have been recurrent and persistent, resulting from complex interactions of the atmosphere with the oceans and the geographic and physiographic characteristic of the country. Several researchers have approached this phenomenon with indices to characterize it using features such as intensity, duration and frequency. In this study we analyze droughts in a spatiotemporal context at scales of 3, 6, 12 and 24 months with SPI and SPEI indices at 19 weather stations located in middle and upper regions of the Sonora River basin, Mexico, for the period 1974-2013. The regions were defined according to mean annual rainfall behavior, applying statistical techniques and analyzing the physiographic characteristics of the study region. Results indicate that drought intensity increased at the end of the time series analyzed, and important periods were identified in the years 1997, 1999, 2000 and 2011 to 2013. SPEI defined the drought periods and the increasing intensity trend better than SPI, demonstrating the importance of including variables such as evapotranspiration in the balance of available water.

In 1926, during a convulsive political period, the Lyceum Club Femenino (Lyceum Women’s Club) was founded in Madrid. The members belonged to the bourgeoisie and the aristocracy class, and its purpose was to promote artistic and social-cultural initiatives in support of gender equality. Amongst these women, was Concepción Méndez Cuesta, who was known for the contributions she made to the revitalization of the Spanish cultural panorama during the ’20s and ’30s of last century, as well as for the exposure her editorial and printer work provided while working alongside her husband, Altolaguirre, a member of Generation ’27. Through the domains of reality and dreams projected by the poet from Madrid, the vigorous collective and personal project is explored beyond its inadequacies and it launched post-civil war settling with the exile and the shadowing of other groups.

In this text, a discursive strategy is applied by Colombian artist Helena Martín Franco. She analyzes the perception of an alter ego to demonstrate the oppressive principals in which the feminine identity is framed. Given that identity is a set of traits that distinguish a group or individual to others, artists like Martín Franco are not satisfied with passively assuming the traits that define the identity of her gender. She is mindful that the identity she practices is a result of fiction created within the political patriarchy framework, in which she resorts to the creation of her own alter ego as a strategy for liberation and resistance against oppressive principals. Thus, evidencing the need to resignify the concept of identity like post-colonial theory had proposed that it is not correct to assume “identity” as an unequivocal class.

This text touches on several examples of Spanish female artists of the 21st century. Public space throughout history, especially in contemporary history has been where their demands have taken place, allowing our society to progress towards democracy and freedom. It has been notably challenging for women to be able to take over this space. Nevertheless, and since the French Revolution, these women have been out on the streets claiming their social rights. They were not indifferent towards artistic manifestations and united to this fight through urban art, initiatives, urbanism, and posters. Nowadays, these initiatives have become collective due to the power of another public space platform, social media, allowing feminist art to empower the streets without any difficulties.

This investigation reflects on performance art done by artists like Pola Weiss, Rocío Boliver e Itziar Okariz, specifically interpreting artistic actions and productions in which artists transgress poetics and aesthetics through the textuality of the body. I make an analysis from an aesthetic and political perspective of the use of the female body, their poses, actions, and locations. The objective of this text is to illustrate the role of artistic expressions of women in current society and a possible interpretation that is drawn from their representations the suggests poetics. This is a union in the search of possible ethical, aesthetics, cultural, political and social representations that arise from the female body and mind, employing it in performance art, video art, video dance, and circulacionism.

Mystery is one of the feminine qualities highlighted by Marcel Duchamp and Byung-Chul Han when referring to the shadow as a symbol in feminine erotism, and concealment as an element of the intrinsic mystery to beauty. In a way, this concept is related clearly to the place the creative woman has had throughout art history, creating in the shadows. However, something that was against her, has now become one of the most powerful aesthetic features of her nature. Committing to a poetic path of feminine mystery, a brief walkthrough artistic figures of Ibero-American contemporary art is explored. Some of these artists are more renowned, and others remain in the shadows whose work is about beauty and its relation to mystery, concealment, absence, identity, and secrets.

In the mid-20th century, a cultural revolution arose, and as a result, an independent and uncertain woman emerged. This new woman could do anything she would like without having to be tied to social or sexual standards that were common in androcentric societies, demonstrating she was neither predisposed nor limited to a specific behavioral pattern; on the contrary, she could have freedom of choice. Nevertheless, there are certain individuals who still associate women solely to activities related to domestic duties. Therefore, the Venezuelan artists Malu Valerio and Mariana Sellanes showcased in their textile work the freedom and power women have achieved. By doing this, women are demonstrating they are individuals who are capable to follow their own emotions and preferences.