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"Gómez, A"
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Gómez-Peña unplugged : texts on live art, social practice and imaginary activism (2008-2019)
\"Gómez-Peña Unplugged is an anthology of recent writings from Guillermo Gómez-Peña, a figure who stands alone as unique and ground-breaking in the history of performance art, and as the Artistic Director of transdisciplinary performance troupe La Pocha Nostra. Throughout this collection, Gómez-Peña tackles literature, theory, pedagogy, activism and live art in an eclectic mix that demonstrates how the process of writing is simultaneously a performative exercise in embodied language. The writing stands as a call for action utilizing what Gómez-Peña terms 'imaginary activism' and 'radical citizenship'; it invites the reader to embody a borderless, polygendered, cross generational and race literate ethos. This timely anthology comes straight from the heart of a troubled Trump-era United States and a crime cartel ridden Mexico. Artists are prompted to engage in radical performance pedagogy within the civic realm and to think of themselves as 'artivists' participating in the great debates of our times. By encouraging artists and emerging writers to wildly imagine their practice beyond the normative art world and academia, this book is a unique read for scholars and students of political theatre, performance art, cultural performance, literature, poetry and activism\"-- Provided by publisher.
BOOK
Classification of images of bee pollen according to their producers
The food industry is witnessing a growing interest in pollen due to its nutritional and energy composition. Consumers of bee pollen are increasingly eager to learn about the origins of the products they purchase. Establishing the geographical origin and the producer of pollen can enhance the product’s value and meet consumer demands for transparency in the supply chain. This article presents a novel approach for the classification of images of bee pollen according to their producers using digital images and machine learning. The study focuses on pollen collected from various beekeepers in the Boyacá region of Colombia. A standardized image acquisition process was employed to capture macroscopic images of the pollen samples. These images were then analyzed to extract color information, and machine learning models were trained to predict the producer of the pollen based on its color characteristics. The results demonstrate that the proposed approach can effectively determine the producer of pollen samples based on their color information. The model achieved an accuracy rate of 85% in associating pollen samples with their respective beekeepers. This outcome has significant implications for traceability and transparency in the bee pollen industry, offering a cost-effective and accessible method to verify the product’s origin.
Journal Article
Extraction and Physicochemical Characterization of Dried Powder Mucilage from Opuntia ficus-indica Cladodes and Aloe Vera Leaves: A Comparative Study
Cactaceae and Asphodelaceae are native desert plants known for their high mucilage content, which is a polysaccharide of growing interest in the food, cosmetic, and pharmaceutical industries. In this study, powdered mucilage was obtained from cladodes of Opuntia ficus-indica (OFI) and aloe vera (AV) leaves, and their molecular, morphological, and thermal properties were investigated and compared. Additionally, their dietary fiber content was determined. Three-dimensional molecular models were calculated for both mucilages using ab initio methods. Vibrational spectra (FTIR and Raman) revealed intramolecular interactions and functional groups that were specified with the help of theoretical ab initio and semi-empirical calculations. SEM micrographs measured at magnifications of 500× and 2000× demonstrated significantly different superficial and internal morphologies between these two mucilages. Thermal analysis using DSC/TGA demonstrated superior thermal stability for the OFI mucilage. The dietary fiber content in OFI mucilage was more than double that of AV mucilage. Our results show that both dehydrated mucilages present adequate thermal and nutritional properties to be used as functional ingredients in industrial formulations; however, OFI mucilage exhibited better physicochemical and functional characteristics than AV mucilage as a raw material.
Journal Article
Associations between Physical Fitness, Bone Mass, and Structure in Older People
The main aim was to analyse the associations between several physical fitness variables and bone parameters in a sample of elderly people. 129 participants (94 females and 35 males, 76.2±5.4 y) from the EXERNET cohort of Zaragoza (Spain) were included in the study. Physical fitness was assessed using the Senior Fitness Test Battery. Peripheral quantitative computed tomography (pQCT) at the tibia and dual-energy X-ray absorptiometry (DXA) at the hip and lumbar spine were used to assess bone and muscle parameters. Partial correlations were used to describe the associations between fitness and bone parameters. A stepwise regression analysis was used to determine the influence of fitness variables on bone parameters. In males, significant correlations were found between lower body strength and agility with bone total mineral density (Tt.BMD) (r=0.41 and -0.50) and cortical thickness (r=0.40 and -0.50, respectively) and walking speed with total and cortical density (r=−0.41 and -0.40, respectively), all measured at tibia (all p<0.05). Regarding DXA, neck areal bone mineral density (aBMD) correlated with flexibility (r=−0.37) and walking speed (r=0.39) and Ward’s triangle with walking speed (r=0.39). Agility predicted Tt.BMD and cortical thickness (r2 change=24.8% and 23.0%), while walking speed predicted cortical bone mineral density (r2 change=19.5%) (all p<0.05). Females showed correlations between balance and total hip aBMD (r=0.27) and trochanter aBMD (r=0.25). Balance predicted trochanter (r2 change=4.2%) and total hip aBMD (r2 change=4.9%) (both p<0.05). In conclusion, bone mass in elderly males seems to be more influenced by physical fitness than in females, being agility and walking speed the variables showing greater associations. Other variables should be taken into account in females for future research.
Journal Article
Bottom-up construction of a superstructure in a porous uranium-organic crystal
Bottom-up construction of highly intricate structures from simple building blocks remains one of the most difficult challenges in chemistry. We report a structurally complex, mesoporous uranium-based metal-organic framework (MOF) made from simple starting components. The structure comprises 10 uranium nodes and seven tricarboxylate ligands (both crystallographically nonequivalent), resulting in a 173.3-angstrom cubic unit cell enclosing 816 uranium nodes and 816 organic linkers—the largest unit cell found to date for any nonbiological material. The cuboctahedra organize into pentagonal and hexagonal prismatic secondary structures, which then form tetrahedral and diamond quaternary topologies with unprecedented complexity. This packing results in the formation of colossal icosidodecahedral and rectified hexakaidecahedral cavities with internal diameters of 5.0 nanometers and 6.2 nanometers, respectively—ultimately giving rise to the lowest-density MOF reported to date.
Journal Article
A look to differential
This paper reveals results of a research related to the presentation of the concept of differential for functions of a variable, from some calculus textbooks. Given that the concept of differential is closely linked to the concepts of derivative, integral and differential equation, the objective is to analyze the different ways of presenting the concept from those instances, in order to determine whether the presentation facilitates its understanding. The research follows a qualitative methodology based on a bibliographic review and conceptual didactic analysis, proceeding from content analysis corresponding to the notion of differential. It was found that the concept of differential in textbooks is presented in a geometric context, as an increment of a variable and as a function, dispossessed of its arithmetic meaning, being impossible to suppress the concept in the formal construction of the calculus.
Journal Article
Metaphors in textbooks of differential equations
This research is an approach to the study of metaphors in the teaching of differential equations, present in textbooks. The objective is to analyse the cognitive metaphors that facilitate learning in the search for the solution of homogeneous linear differential equations. The methodology used was content analysis applied to a subjective sample of four university texts. The analysis allowed to find that the texts that use linear algebra make it easier the teaching of differential equations, and it is concluded that the metaphors from linear algebra are fundamentals in the teaching of linear differential equations, the basic concept facilitates the learning for the construction of the general solution of linear differential equations.
Journal Article
Atmospheric River Brings Warmth and Rainfall to the Northern Antarctic Peninsula During the Mid‐Austral Winter of 2023
Contrasting the extensive research on summer atmospheric rivers (ARs) in the Antarctic Peninsula (AP), winter AR impacts are less understood. This study examines a unique warming event from 1 to 3 July 2023, using in situ winter observations and ERA5 reanalysis. On 2 July, Frei station experienced an extreme warm event with a temperature of 2.7°C and a significant rise in the freezing level, coinciding with winter rainfall. A pressure dipole pattern over the AP, with contrasting circulations over Bellingshausen and Weddell Seas, facilitated an AR, carrying warm, humid air initially from South America/Atlantic and then the southeast Pacific. This shift resulted in anomalous water stable isotope composition in precipitation. Trends suggest a strengthening winter pressure dipole, associated with increased AR frequency and higher temperatures in northern AP. These findings highlight the importance of winter observations in exploring AR impacts, bridging knowledge gaps about winter AR behaviors.
Plain Language Summary
The Antarctic Peninsula is increasingly witnessing climate extremes during summer, while the understanding of such extremes in winter remains limited. Our study explores a significant warming event in the northern Peninsula in early July 2023, utilizing recent winter in situ observations and atmospheric analysis. On 2 July, an exceptional temperature of 2.7°C was recorded, significantly altering the atmospheric freezing level and causing rainfall instead of snow. Our analysis revealed a unique atmospheric pattern around the Peninsula, characterized by varying air movements over the Bellingshausen and Weddell Seas. This pattern facilitated an “atmospheric river,” a flow of warm and moist air from lower latitudes, including continental South America/Atlantic and the southeast Pacific, as reflected in the precipitation's water stable isotope composition. This event is indicative of a potential trend toward more frequent and severe occurrences, emphasizing the urgent need for comprehensive winter research in the Antarctic Peninsula to understand the broader implications of extreme weather events and climate change.
Key Points
Early July 2023 had extreme winter warmth with rainfall in the northern Antarctic Peninsula, favored by an atmospheric river
In recent decades, strengthened winter pressure dipole has directed northerly warm and moist air, resulting in warm events in the region
We highlight the need for expanded winter research in the Antarctic Peninsula to better understand climate change and extreme weather events
Journal Article
Analysis of the Capacity of the Fenton Process for the Treatment of Polluted Wastewater from the Leather Dyeing Industry
In this work, the capacity of the Fenton oxidation process for the degradation of color and organic matter contained in the wastewater generated in the leather dyeing stage (WWDS) of an industrial tannery was evaluated. The wastewater characteristics included, among others, high toxicity (lethal concentration for Artemia salina, 24 h test, 50% of population = 93.71 ppm), high dye concentration (36 mg/L, yellow color), high chromium concentration (3.34 mg/L), and low biodegradability index (BOD5/COD ratio = 0.083). From an experimental design, the response surface methodology, and the multiobjective optimization analysis, the following optimal operating conditions were established: initial pH = 3.15, [Fe2+] = 0.981 mM, and [H2O2] = 5.38 mM. After 10 min of oxidation (determined from kinetic studies), it reached approximately 97% decolorization, COD reduction of approximately 82%, and TOC mineralization of approximately 92%. A synergistic effect of Fenton’s reagents for TOC removal (STOC = 0.8) and decolorization (SCN = 0.28) of the WWDS under study was confirmed experimentally. An increase in the biodegradability index, to a value of approximately 0.3, was confirmed. The cost of the treatment was estimated at 0.0112 USD/m3. Thus, the Fenton oxidation process allowed compliance with current Colombian environmental regulations and considerably improved the biodegradability and toxicity characteristics of the studied industrial effluent. It can be considered as an efficient alternative, easy to carry out on an industrial batch scale, and economically viable for the treatment of wastewater from the leather dyeing stage of an industrial tannery.
Journal Article