Agroecological entrepreneurship, public support, and sustainable development: The case of rural Yucatan (Mexico)

This paper offers an approach to Yucatecan social reality in terms of entrepreneurship and the process of creating companies dedicated to the production and/or commercialization of agroecological products, considering its contribution to sustainable rural development. The key actors’ perspective towards the existence of policies that favor land sustainability, assist in the development of rural areas and their population, and support these business initiatives is also presented. Likewise, it illustrates the small entrepreneurs’ standpoint on the role of public institutions in promoting wealth generation and sustainable development in lower growth areas, such as the state of Yucatan, in Mexico. A qualitative methodology was used for this research, based on in-depth interviews with a group of businessmen and-women from the region. The main results give a pessimistic view of institutional concern regarding both production and consumption of agroecological products and, therefore, the promotion of these enterprises for the socioeconomic development of Yucatan. From these findings, we detect: (a) A policy of scarce support for this type of production, due to political priorities; (b) inadequate management that prevents the consolidation of certain structures needed to support agroecological enterprises; (c) a lack of confidence in the Yucatecan government, which does not promote or support a social network of collaboration between agroecological producers and marketers; (d) a difficulty in undertaking agroecological enterprises because of social and cultural norms and poor environmental awareness among the population; (e) significant training deficiencies among entrepreneurs in agroecological agriculture; (f) absence of adequate distribution channels for agroecological products; and (g) excessive bureaucratic obstacles through laws that hinder entrepreneurial processes

Characterization of Oxidative Lipidomics and Autophagy Induction in Chlamydomonas reinhardtii Under Abiotic Stress

Autophagy constitutes an essential process triggered upon by oxidative stress that enables cells to recycle damaged biomolecules and organelles, which is eventually traced by immunodetection with anti-ATG8. In parallel with autophagy induction, carbon metabolism in Chlamydomonas reinhardtii under abiotic stress is diverged toward lipid biosynthesis and lipid droplet accumulation, which can be analyzed by a simple thin-layer chromatography and in vivo staining with the fluorescent probe BODIPY 493/503. We show the responses in Chlamydomonas cells exposed to mercury or cadmium (0–50 μM doses), as examples of oxidative stress-mediated changes in autophagy and lipid metabolism, monitored with the procedures described in this repor

A little garbage in, lots of garbage out: Assessing the impact of careless responding in personality survey data

[EN]In self-report surveys, it is common that some individuals do not pay enough attention and effort to give valid responses. Our aim was to investigate the extent to which careless and insufficient effort responding contributes to the biasing of data.We performed analyses of dimensionality, internal structure, and data reliability of four personality scales (extroversion, conscientiousness, stability, and dispositional optimism) in two independent samples. In order to identify careless/insufficient effort (C/IE) respondents, we used a factor mixture model (FMM) designed to detect inconsistencies of response to items with different semantic polarity. The FMM identified between 4.4% and 10% of C/IE cases, depending on the scale and the sample examined. In the complete samples, all the theoretical models obtained an unacceptable fit, forcing the rejection of the starting hypothesis and making additional wording factors necessary. In the clean samples, all the theoretical models fitted satisfactorily, and the wording factors practically disappeared. Trait estimates in the clean samples were between 4.5% and 11.8% more accurate than in the complete samples. These results show that a limited amount of C/IE data can lead to a drastic deterioration in the fit of the theoretical model, produce large amounts of spurious variance, raise serious doubts about the dimensionality and internal structure of the data, and reduce the reliability with which the trait scores of all surveyed are estimated. Identifying and filtering C/IE responses is necessary to ensure the validity of research result

Nuevos datos geocronológicos 40Ar-39Ar en dos puntos singulares del macizo de Anaga (Tenerife): Punta Poyata e Igueste de San Andrés. Consecuencias de interés

En este trabajo se aportan nuevos datos geocronológicos Ar40-Ar39 en rocas ancaramíticas submarinas localizadas en dos puntos singulares del macizo de Anaga (NE de Tenerife): las ancaramitas submarinas hidrotermalizadas de Punta Poyata (NNW de Anaga) y las lavas submarinas ancaramíticas del Barranco de Igueste (SE de Anaga). Las muestras estudiadas pertenecen a afloramientos pertenecientes a los niveles estratigráficos más inferiores de la secuencia volcánica que conforma el edificio de Anaga. En Punta Poyata se tomaron dos especímenes que dieron edades de 12,2 ± 1,9 Ma and 13,0 ± 1,0 Ma. En el barranco de Igueste los resultados geocronológicos de las muestras tomadas dieron edades de 12,7 ± 1,6 Ma and 9,7 ± 1,0 Ma. Estos datos sugieren que el macizo de Anaga comenzó su desarrollo subaéreo antes de lo que anteriormente se creía, ajustándose dicho período inicial al Mioceno Medio en lugar de al Mioceno tardío como previamente se asumía.This work provides new Ar40-Ar39 geochronological data in submarine ankaramite rocks located in two distant points of Anaga (NE Tenerife): the submarine hydrothermally altered ankaramites of Punta Poyata area (NNW Anaga) and the ankaramitic pillow lavas at Barranco de Igueste (SE Anaga). The studied samples were collected from outcrops of the lowest stratigraphic levels throughout the volcanics that build up the Anaga massif. At Punta Poyata, two collected samples yielded an age of 12,2 ± 1,9 Ma and 13,0 ± 1,0 Ma. At Barranco de Igueste, sample results are of 12,7 ± 1,6 Ma and 9,7 ± 1,0 Ma. These data support the assumption that the Anaga massif began its subaerial growth earlier than that previously was supposed, most likely in the Mid-Miocene Instead of late Miocene as currently believed.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Investigation of the origin and magnitude of debris flows from the Payhua Creek basin, Matucana area, Huarochirí Province, Perú

The small city of Matucana (population 5800), Province of Huarochirí, Perú is located on the flood plain of Rimac River in Andes Occidental, approximately 75 km east of Lima at an elevation of 2390 m (area of 11° 50.489’ S, 76° 22.857’ W). Adjacent ridges and mountain peaks rise to 5000 m. Matucana shares a 300m wide valley bottom with two transportation arteries: Carretera Central, the only highway in Perú connecting the Amazon basin to the Pacific Coast and Ferrocarril Central, the highest standard gauge railway in the world which services mines and communities in the Andes. The present course of Rimac River is controlled by a dike and fill for the highway and railroad. These structures confine it to the northern portion of its flood plain. Consequently, parts of Matucana are lower in elevation than the bed of Rimac River. Payhua Creek (PC), a steep, debris-flow-prone tributary to Rimac River, has built an extensive fan at the upstream end of the city. Debris flows from PC has dammed Rimac River and diverted it into Matucana. This type of disaster occurred 1959 and 1983 when heavy precipitation occurred in the normally arid Andes Occidental. The 1959 event was particularly notable as it destroyed 90% of Matucana with loss of life. Although these events were not well documented, investigation of the PC fan and documentation of 1983 deposits on the fan indicate that the 1983 debris flow had a volume in the 0.12 106 to 106m3 range. Investigation of surficial and bedrock geology including mapping of all landslides in PC basin was carried out in 2004. A landslide complex immediately west of Payhua village is the most significant source of debris flow sediment in the basin. Incision of an unfavourable succession of andesite flows overlying a pervasively fractured tuff is responsible for the concentration of landslides in the Payhua village area. The area affected by landsliding in this area has increased by a factor of five since 1951. The PC basin upstream from Payhua has been a relatively small source of debris flows during the past 600 to 800 years based upon archaeological evidence. Exposures of debris flow deposits in the PC fan indicate that debris flow events larger than those of 1959 and 1983 have occurred in the recent geologic past. Matucana has also grown significantly since 1983 and has further encroached on the Rimac River flood plain and the PC fan. As a result, if debris flows of the magnitude of those in 1959 and 1983 occur, direct burial of the upstream area of Matucana by debris flows is likely

Diagnóstico del cultivo de tomate en la zona metropolitana de Bucaramanga

El tomate es una hortaliza de gran demanda en el área metropolitana de Bucaramanga, para consumo fresco, como condimento y en forma de salsa. El presente estudio se adelantó con el propósito de conocer la problemática del cultivo de tomate respecto a la utilización de agroquímicos, mano de obra y fotosanidad, en los cultivos establecidos en el área de influencia de Bucaramanga en el año de 1987. Para la realización de este trabajo se encuestaron 25 agricultores ubicados en 14 veredas de vocación tomatera de los municipios de Bucaramanga, Floridablenca, Piedecuesta, Girón y Cepitá. Los resultados más importantes de la investigación fueron: la mayoría de los agricultores manejan inadecuadamente el cultivo en cuanto a labores culturales básicas. El control de plagas y enfermedades lo hacen por calendario, notándose un total desconocimiento de los sistemas de manejo integrado de plagas y enfermedades que tan excelentes resultados ha producido en otras zonas de cultivo como los del Valle del Cauca. Se encontró igualmente que no se destruyen los residuos de cosecha no se practica la rotación de cultivos de manera significativa. Hay uso indiscriminado y deficiente aplicación de plaguicidas con lo cual se incrementan los costos de producción y se contamina el producto cosechado, el cultivador y el ambiente. Los problemas fitosanitarios relevantes detectados en la fecha, lo constituyen los nemátodos, el barrenador del fruto (Neoleucinodes elegantalis), la virosis y la gota, La rentabilidad del cultivo es baja, el crédito insuficiente e inoportuno y no se cuenta con asistencia técnicaTomate-Solanum lycopersicu

Origin of inverse Rashba-Edelstein effect detected at the Cu/Bi interface using lateral spin valves

The spin transport and spin-to-charge current conversion properties of bismuth are investigated using permalloy/copper/bismuth (Py/Cu/Bi) lateral spin valve structures. The spin current is strongly absorbed at the surface of Bi, leading to ultrashort spin-diffusion lengths. A spin-to-charge current conversion is measured, which is attributed to the inverse Rashba-Edelstein effect at the Cu/Bi interface. The spin-current-induced charge current is found to change direction with increasing temperature. A theoretical analysis relates this behavior to the complex spin structure and dispersion of the surface states at the Fermi energy. The understanding of this phenomenon opens novel possibilities to exploit spin-orbit coupling to create, manipulate, and detect spin currents in two-dimensional systems

Influence of chronic ocular hypertension on emmetropia: Refractive, structural and functional study in two rat models

Chronic ocular hypertension (OHT) influences on refraction in youth and causes glaucoma in adulthood. However, the origin of the responsible mechanism is unclear. This study analyzes the effect of mild-moderate chronic OHT on refraction and neuroretina (structure and function) in young-adult Long-Evans rats using optical coherence tomography and electroretinography over 24 weeks. Data from 260 eyes were retrospectively analyzed in two cohorts: an ocular normotension (ONT) cohort (20 mmHg), in which OHT was induced either by sclerosing the episcleral veins (ES group) or by injecting microspheres into the anterior chamber. A trend toward emmetropia was found in both cohorts over time, though it was more pronounced in the OHT cohort (p < 0.001), especially in the ES group (p = 0.001) and males. IOP and refraction were negatively correlated at week 24 (p = 0.010). The OHT cohort showed early thickening in outer retinal sectors (p < 0.050) and the retinal nerve fiber layer, which later thinned. Electroretinography demonstrated early supranormal amplitudes and faster latencies that later declined. Chronic OHT accelerates emmetropia in Long–Evans rat eyes towards slowly progressive myopia, with an initial increase in structure and function that reversed over time. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Chronic glaucoma using biodegradable microspheres to induce intraocular pressure elevation. Six-month follow-up

Background: To compare two prolonged animal models of glaucoma over 24 weeks of follow-up. A novel pre-trabecular model of chronic glaucoma was achieved by injection of biodegradable poly lactic-co-glycolic acid (PLGA) microspheres (10–20 µm) (Ms20/10) into the ocular anterior chamber to progressively increase ocular hypertension (OHT). Methods: Rat right eyes were injected to induce OHT: 50% received a suspension of Ms20/10 in the anterior chamber at 0, 2, 4, 8, 12, 16 and 20 weeks, and the other 50% received a sclerosing episcleral vein injection biweekly (EPIm). Ophthalmological clinical signs, intraocular pressure (IOP), neuroretinal functionality measured by electroretinography (ERG), and structural analysis of the retina, retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) protocols using optical coherence tomography (OCT) and histological exams were performed. Results: Both models showed progressive neuroretinal degeneration (p < 0.05), and contralateral eye affectation. The Ms20/10 model showed a more progressive increase in IOP and better preservation of ocular surface. Although no statistical differences were found between models, the EPIm showed a tendency to produce thicker retinal and thinner GCL thicknesses, slower latency and smaller amplitude as measured using ERG, and more aggressive disturbances in retinal histology. In both models, while the GCL showed the greatest percentage loss of thickness, the RNFL showed the greatest and earliest rate of thickness loss. Conclusions: The intracameral model with biodegradable microspheres resulted more like the conditions observed in humans. It was obtained by a less-aggressive mechanism, which allows for adequate study of the pathology over longer periods. © 2021 by the authors. Licensee MDPI, Basel, Switzerland