Planting the Seeds of Change: Im/migrant Life Writings

The subject of land, working it and owning it, is an inherent part of Chicano/a autobiography, as exemplified by the life writings of Elva Treviño Hart. The term “im/migrant” connotes transition and mobility, crossing borders, shifting parameters, all of which are fundamental facts of life for Chicano/a authors. A collective sense of community proves to be the only stasis in the narrators’ young lives, and the migrant camps become a microcosm in which societal and cultural rituals are conducted, despite the lack of control over the constantly shifting spaces they occupy. Being Mexican American, however, signifies a precarious existence in both the Mexican (home, barrio, field) and the Anglo world (school, marketplace), and this coexistence creates a tension between the collective and the individual, which results in an “open wound,” as expressed by Gloria Anzaldúa. From the outset, Elva Treviño Hart depicts her life on the periphery in terms of work, class, ethnicity and gender. Her physical detachment at the edge of the field is symbolic of her sense of alienation at home and in Anglo society. Like Treviño Hart, many Chicanos/as portray their family’s need to claim their own space, to declare ownership, and to procure a sense of stability in an often alien(ating) world. Ultimately, however, many of these authors reconcile the two worlds they navigate by separating from their community through the process of writing and self-discovery. In so doing, they embrace their culture and become empowered, not devalued, by their difference. Thus, these Chicano/a writers help to restructure the traditional notion of autobiography by (re)claiming their space and re-defining and re-negotiating the literary and cultural parameters which once were perceived to be immutable

Cu2ZnSnS4−Au Heterostructures: Toward Greener Chalcogenide- Based Photocatalysts

Chalcogenide-based semiconductor-metal heterostructures are interesting catalysts for solar-to-chemical energy conversion, but current compositions are impractical due to the relative toxicity and/or scarcity of their constituent elements. To address these concerns, Cu2ZnSnS4 (CZTS) emerged as an interesting alternative to other chalcogenide-based semiconductors; however, the fabrication of CZTS metal heterostructures remains unexplored. In this paper, we systematically explore four methods of synthesizing CZTS-Au heterostructures, specifically: reaction of CZTS nanorods with either a soluble molecular gold precursor (AuCl3) or preformed gold (Au) nanoparticles, each under thermal (heating in the dark) or photochemical reaction conditions (350 nm lamp illumination at room temperature). We find that using AuCl3 under thermal deposition conditions results in the most well-defined CZTS-Au heterostructures, containing \u3e99% surface-bound 2.1 ± 0.5 nm Au islands along the whole length of the nanorod. These CZTS-Au heterostructures are photocatalytically active, reducing the model compound methylene blue upon irradiation much more effectively than bare CZTS nanorods. We also demonstrate the removal of Au from the CZTS-Au heterostructures by amalgamation. These results open up a new area of greener, CZTS-based photocatalysts for solar-to-chemical energy conversion

Axial composition gradients and phase segregation regulate the aspect ratio of Cu2ZnSnS4 nanorods

Cu2ZnSnS4 (CZTS) is a promising material for solar energy conversion, but synthesis of phase-pure, anisotropic CZTS nanocrystals remains a challenge. We demonstrate that the initial concentration (loading) of cationic precursors has a dramatic effect on the morphology (aspect ratio) and composition (internal architecture) of hexagonal wurtzite CZTS nanorods. Our experiments strongly indicate that Cu is the most reactive of the metal cations; Zn is next, and Sn is the least reactive. Using this reactivity series, we are able to purposely fine-tune the morphology (dots versus rods) and degree of axial phase segregation of CZTS nanocrystals. These results will improve our ability to fabricate CZTS nanostructures for photovoltaics and photocatalysis

Got LiZnP? Solution phase synthesis of filled tetrahedral semiconductors in the nanoregime

We report the synthesis and characterization of nanocrystalline LiZnP. The reaction proceeds through a zinc metal intermediate followed by rapid incorporation of lithium and phosphorus. We demonstrate flexibility in the selection of Li, Zn, and P precursors, as well as extension of this method to other half-Heusler phases

Estudio de factibilidad para la implementación de una plataforma logística en el cantón Colta

El objetivo de este estudio fue determinar la necesidad de implementar una plataforma logística en el cantón Colta para la transferencia y traslado mercancías, funcionamiento operativo, logístico y comercial, intercambio y acopio de mercancía que están a cargo de los transportistas. Para el desarrollo de la investigación se aplicó la metodología inductivo-deductivo, lo que permitió analizar una a una las variables influyentes en el tema de investigación y posteriormente llegar a un conocimiento general; por otro lado, fue de carácter analítico-sintético, ya que permitió estudiar de forma individual las partes involucradas para luego agruparlas. El levantamiento de información se realizó a través de encuestas para identificar el criterio de los conductores de transporte pesado y en base a ello generar la solución. Una vez culminado el proceso del prediseño de la plataforma logística, se ha logrado identificar la localización óptima para el proyecto, mismo que será en la Panamericana troncal de la Sierra E35 (frente a la laguna de Colta) y la avenida 487 ya que cumple con los requerimientos, como: acceso a la panamericana de la sierra E35, disponibilidad de servicios básicos, mano de obra, cercanía a centros de abastecimiento e intercambio, cercanía al centro de salud, entre otros. La misma tendrá una capacidad de parqueadero mensual de 300 vehículos de carga pesada. En conclusión, el transporte pesado se ha convertido en un eje primordial de la economía tanto a nivel cantonal como provincial, por tanto, la investigación realizada está acorde a las necesidades del cantón. Se recomienda a las autoridades competentes ejecutar medidas y acciones en cuanto al transporte de carga pesada e implementar como necesidad inmediata la plataforma logística que permitirá disminuir el caos ocasionado por los vehículos de carga pesada, sumado a esto será económica y financieramente rentable.The objective of this study was to determine the need to implement a logistics platform in Colta canton for the transportation, operational, logistical and commercial operation, exchange and collection of products. For the development of the research, the inductive-deductive methodology was applied, which allowed us to analyze each one of the variables that affect the study to reach a general vision of the situation. On the other hand, it was analytical-synthetic study as it allowed to individually analyse the parts and then put them together. The information was collected through surveys to identify the opinion of transport drivers to generate a solution. Once the pre-design process of the logistics platform was completed, it was possible to identify the optimal location to develop the project which will be established in the Panamericana de la Sierra E35 (in front of the Colta lagoon) and the 487 avenue, as it complies with the requirements, such as: access to the Panamericana de la Sierra E35, availability of basic services, supply and exchange centers, a near health center, among others. It will have a monthly parking capacity of 300 heavy-duty vehicles. In conclusion, heavy transportation has become a fundamental axis of the economy both at the cantonal and provincial level. Therefore, the research was developed according to the needs of the canton. It is recommended that the authorities implement measures and take actions in relation with cargo transportation and inmediately implement the logistics platform which will reduce the chaos caused by heavy cargo vehicles as it will be economically and financially profitable

Titanium-doped PET nanoplastics of environmental origin as a true-to-life model of nanoplastic

Altres ajuts: acords transformatius de la UABThe increased presence of secondary micro/nanoplastics (MNPLs) in the environment requires urgent studies on their potentially hazardous effects on exposed organisms, including humans. In this context, it is essential to obtain representative MNPL samples for such purposes. In our study, we have obtained true-to-life NPLs resulting from the degradation, via sanding, of opaque PET bottles. Since these bottles contain titanium (TiONPs), the resulting MNPLs also contain embedded metal. The obtained PET(Ti)NPLs were extensively characterized from a physicochemical point of view, confirming their nanosized range and their hybrid composition. This is the first time these types of NPLs are obtained and characterized. The preliminary hazard studies show their easy internalization in different cell lines, without apparent general toxicity. The demonstration by confocal microscopy that the obtained NPLs contain Ti samples offers this material multiple advantages. Thus, they can be used in in vivo approaches to determine the fate of NPLs after exposure, escaping from the existing difficulties to follow up MNPLs in biological samples

Abordaje de control de daños y reanimación reducida de paciente pediátrico politraumatizado en urgencias: Damage control approach and reduced resuscitation of the polytraumatized pediatric patient in the emergency room

Polytrauma in pediatric patients is a frequent event, so its timely approach and management define its prognosis. Polytrauma is defined as the presence of two or more traumatic injuries or a single one that endangers life or there is a risk of serious sequelae; resuscitation is understood as the restoration of vital functions of the patient in the pre-hospital area to the hospital area aimed at avoiding the damage caused by the fatal pentad of trauma (coagulopathy, acidosis, hypothermia, hyperglycemia and hypoxia) for which the Damage control protocol which is referred to all the maneuvers that have the purpose of preserving life, but without carrying out definitive repairs in order to mitigate complications derived from the prolonged state of shock, secondary to a prolonged surgical time that postponed adequate resuscitation, this reduced resuscitation consists of 6 precise indications for its performance, being approached from the TEP (Pediatric Evaluation Triangle) and the MARCHDEF protocol (Massive Bleeding, Airway, Breathing, Circulation, Hypothermia, Neurological Deficit, Glycemia, Pain, Exposure, FAST).El politrauma en el paciente pediátrico es un evento frecuente por lo que su abordaje y manejo oportuno definen el pronóstico del mismo. Se define como politrauma a la presencia de dos o más lesiones traumáticas o una sola que pone en peligro la vida o existe el riesgo de secuelas graves; la reanimación se entiende como el restablecimiento de las funciones vitales del paciente en el área prehospitalaria hasta el área hospitalaria encaminados a evitar el daño causado por la pentada mortal del trauma (coagulopatía, acidosis, hipotermia, hiperglicemia e hipoxia) por lo que se realizó el protocolo de control de daños el cual es referido a todas la maniobras que tiene el fin de preservar la vida, pero sin llevar a cabo reparaciones definitivas con el objetivo de mitigar complicaciones derivadas del estado de choque prolongado, secundario a un tiempo quirúrgico prolongado que postergaba la reanimación adecuada, ésta reanimación reducida consta de 6 indicaciones precisas para su realización, siendo abordado desde el TEP (Triangulo de evaluación Pediatrica) y protocolo MARCHDEF (Hemorragias masivas, Vía aérea, Respiración, Circulación, Hipotermia, Déficit Neurológico, Glicemia, Dolor, Exposición,  FAST)

Applied science facilitates the large-scale expansion of protected areas in an Amazonian hot spot

Meeting international commitments to protect 17% of terrestrial ecosystems worldwide will require \u3e3 million square kilometers of new protected areas and strategies to create those areas in a way that respects local communities and land use. In 2000–2016, biological and social scientists worked to increase the protected proportion of Peru’s largest department via 14 interdisciplinary inventories covering \u3e9 million hectares of this megadiverse corner of the Amazon basin. In each landscape, the strategy was the same: convene diverse partners, identify biological and sociocultural assets, document residents’ use of natural resources, and tailor the findings to the needs of decision-makers. Nine of the 14 landscapes have since been protected (5.7 million hectares of new protected areas), contributing to a quadrupling of conservation coverage in Loreto (from 6 to 23%). We outline the methods and enabling conditions most crucial for successfully applying similar campaigns elsewhere on Earth

Preparation and Instability of Nanocrystalline Cuprous Nitride

Low-dimensional cuprous nitride (Cu3N) was synthesized by nitridation (ammonolysis) of cuprous oxide (Cu2O) nanocrystals using either ammonia (NH3) or urea (H2NCONH2) as the nitrogen source. The resulting nanocrystalline Cu3N spontaneously decomposes to nanocrystalline CuO in the presence of both water and oxygen from air at room temperature. Ammonia was produced in 60% chemical yield during Cu3N decomposition, as measured using the colorimetric indophenol method. Because Cu3N decomposition requires H2O and produces substoichiometric amounts of NH3\u3e, we conclude that this reaction proceeds through a complex stoichiometry that involves the concomitant release of both N2 and NH3. This is a thermodynamically unfavorable outcome, strongly indicating that H2O (and thus NH3 production) facilitate the kinetics of the reaction by lowering the energy barrier for Cu3N decomposition. The three different Cu2O, Cu3N, and CuO nanocrystalline phases were characterized by a combination of optical absorption, powder X-ray diffraction, transmission electron microscopy, and electronic density of states obtained from electronic structure calculations on the bulk solids. The relative ease of interconversion between these interesting and inexpensive materials bears possible implications for catalytic and optoelectronic applications