24 research outputs found
Foliar application of zinc oxide nanoparticles and grafting improves the bell pepper (Capsicum annuum L.) productivity grown in NFT system
The bell pepper (Capsicum annuum L.) is a food vegetable with a high nutritional intake, with rich content in vitamins, minerals and antioxidants. In this study, using nutrient film technique (NFT) system, the effect of the zinc oxide nanoparticles on the micromorphology, histology, physiology and production of the grafted pepper was evaluated. The treatments used were grafted and non-grafted plants, four concentrations (0, 10, 20, 30 mg L-1) of zinc oxide nanoparticles, and the experience was organized in a completely randomized design. An increase in grafted plants was observed in the weight, number and size of fruits in 18.1%, 21.8% and 9.6%, the concentration 30 mg L-1 of nanoparticles statistically affected the weight, number and size 46.9%, 47.7% and 18% compared to the control. The interaction with grafted plants and the treatment of 30 mg L-1 of zinc oxide nanoparticles increased fruit weight, number of fruits and size by 62.60%, 57.69% and 29.17% compared to plants without grafting and the control treatment. These results indicate that the use of grafts and zinc oxide nanoparticles could be used in bell pepper production to increase yield
Effects of Enriched Physical and Social Environments on Motor Performance, Associative Learning, and Hippocampal Neurogenesis in Mice
We have studied the motor abilities and associative learning capabilities of adult mice placed in different enriched environments. Three-month-old animals were maintained for a month alone (AL), alone in a physically enriched environment (PHY), and, finally, in groups in the absence (SO) or presence (SOPHY) of an enriched environment. The animals' capabilities were subsequently checked in the rotarod test, and for classical and instrumental learning. The PHY and SOPHY groups presented better performances in the rotarod test and in the acquisition of the instrumental learning task. In contrast, no significant differences between groups were observed for classical eyeblink conditioning. The four groups presented similar increases in the strength of field EPSPs (fEPSPs) evoked at the hippocampal CA3-CA1 synapse across classical conditioning sessions, with no significant differences between groups. These trained animals were pulse-injected with bromodeoxyuridine (BrdU) to determine hippocampal neurogenesis. No significant differences were found in the number of NeuN/BrdU double-labeled neurons. We repeated the same BrdU study in one-month-old mice raised for an additional month in the above-mentioned four different environments. These animals were not submitted to rotarod or conditioned tests. Non-trained PHY and SOPHY groups presented more neurogenesis than the other two groups. Thus, neurogenesis seems to be related to physical enrichment at early ages, but not to learning acquisition in adult mice
Naturaleza y cultura en Ámerica Latina
La concreción del XVIII Foro de Estudiantes Latinoamericanos de Antrología y Arqueología: Cultura y naturaleza en América Latina: escenarios para un modelo de desarrollo no civilizatorio, efectuado en Quito desde el 17 al 23 de julio del 2011, se constituyó en un acontecimiento sumamente significativo para la antropología latinoamericana debido a dos motivos. Primero porque coincidió con la emergencia del movimiento universitario estudiantil latinoamericano que expresaba sus tendencias, propuestas y exigencias de cambios tanto de las prácticas académicas como de los patrones civilizatorios que rigen las relaciones actuales. Segundo, porque se inscribía en un contexto de consolidación de las nuevas democracias de los países andinos, de carácter antineoliberal y basadas en los sujetos de derecho entre los cuales se incluye la naturaleza.
Estos contextos determinaron que el Foro no ponga en escena certidumbres teóricas o metodológicas, ni se preste al exhibicionismo estéril de los avances disciplinares. Más bien, la convocatoria de la antropología y la arqueología fue apenas un pretexto para hablar, con su lenguaje, de nosotros mismos, de lo que somos, de lo que pensamos, de lo que aspiramos y sentimos sobre nuestra Latinoamérica. Lo que hemos visto, oído y compartido, en realidad, no han sido solamente ideas o conceptos sino opciones y toma de posiciones respecto a múltiples encrucijadas. Posición ante situaciones que amenazan la vida, la justicia y los derechos de todos, un desafío epistemológico todavía en ciernes y que no termina de cuajar aún en nuestras prácticas académicas
General and abdominal adiposity and hypertension in eight world regions: a pooled analysis of 837 population-based studies with 7·5 million participants
Background Adiposity can be measured using BMI (which is based on weight and height) as well as indices of abdominal adiposity. We examined the association between BMI and waist-to-height ratio (WHtR) within and across populations of different world regions and quantified how well these two metrics discriminate between people with and without hypertension. Methods We used data from studies carried out from 1990 to 2023 on BMI, WHtR and hypertension in people aged 20–64 years in representative samples of the general population in eight world regions. We graphically compared the regional distributions of BMI and WHtR, and calculated Pearson’s correlation coefficients between BMI and WHtR within each region. We used mixed-effects linear regression to estimate the extent to which WHtR varies across regions at the same BMI. We graphically examined the prevalence of hypertension and the distribution of people who have hypertension both in relation to BMI and WHtR, and we assessed how closely BMI and WHtR discriminate between participants with and without hypertension using C-statistic and net reclassification improvement (NRI). Findings The correlation between BMI and WHtR ranged from 0·76 to 0·89 within different regions. After adjusting for age and BMI, mean WHtR was highest in south Asia for both sexes, followed by Latin America and the Caribbean and the region of central Asia, Middle East and north Africa. Mean WHtR was lowest in central and eastern Europe for both sexes, in the high-income western region for women, and in Oceania for men. Conversely, to achieve an equivalent WHtR, the BMI of the population of south Asia would need to be, on average, 2·79 kg/m² (95% CI 2·31–3·28) lower for women and 1·28 kg/m² (1·02–1·54) lower for men than in the high-income western region. In every region, hypertension prevalence increased with both BMI and WHtR. Models with either of these two adiposity metrics had virtually identical C-statistics and NRIs for every region and sex, with C-statistics ranging from 0·72 to 0·81 and NRIs ranging from 0·34 to 0·57 in different region and sex combinations. When both BMI and WHtR were used, performance improved only slightly compared with using either adiposity measure alone. Interpretation BMI can distinguish young and middle-aged adults with higher versus lower amounts of abdominal adiposity with moderate-to-high accuracy, and both BMI and WHtR distinguish people with or without hypertension. However, at the same BMI level, people in south Asia, Latin America and the Caribbean, and the region of central Asia, Middle East and north Africa, have higher WHtR than in the other regions
Changes in the Thermal Behavior and Surface Area of Transitional Alumina Induced by the Inclusion of Metallic Ions
<div><p>Transitional alumina was synthesized from economical precursors and by precipitation route. The precipitation was carried out by the addition of sodium hydroxide drop by drop to an aqueous solution of aluminum sulfate. The powder obtained was aged for 24 h and then annealed at 600 and 800°C with the purpose to study the changes of surface area and porosity of the material. The textural characteristics of this material were compared with solid containing copper, zinc and iron species. The powder characterization was carried out by X-ray diffraction, thermal analysis, infrared spectroscopy, and N<sub>2</sub> adsorption at 77 K.</p></div
Effects of the Inclusion of Ce and Ni Species on Ti for Modification of K10-Clay by Sol-Gel and their Use as Catalysts in the Liquid-Phase Esterification Systems
The modification of montmorillonite with metallic species affects directly its crystalline structure, texture, porosity, and surface. The interaction of the metallic molecules with the clay matrix, derived from the modification pathway and the characteristics of the adsorbate, modifies the physicochemical properties of montmorillonite, enabling the creation of materials with varied characteristics to be used both as catalysts and adsorbents. Small amounts of metallic species can confer various structural and physicochemical characteristics on the same montmorillonite matrix, depending on the metal incorporated. The objective of the present study was to create an acid-base catalyst based on montmorillonite K10 (K10 Mnt), modified with Ti, Ce, and Ni, for the catalytic esterification of acetic acid and penta-1-ol. K10-Mnt was modified using particles of Ti and of Ti modified with Ce and Ni. The effect of the inclusion of Ti and modified Ti species on the transformation of the physicochemical properties of the K10 Mnt and their contributions to the catalytic esterification syntheses were investigated. Samples were characterized by scanning electron microscopy coupled to an energy-dispersive X-ray spectroscopy system (SEM-EDS), powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), physisorption of N2 at 77 K (BET and BJH), and thermogravimetric analysis (TGA-DTGA). Finally, the original and modified K10 Mnt samples were tested for their catalytic esterification of acetic acid and penta-1-ol in the liquid phase. © 2023, The Author(s), under exclusive licence to The Clay Minerals Society.This study was supported by the DAIPUniversidad de Guanajuato ofce. The authors acknowledge
Cristina Daniela Moncada-Sánchez of the Laboratory for
Research and Characterization of Minerals and Materials of
the University of Guanajuato (LICAMM-UG-Mexico) for the
support in the SEM-EDS analysis. Likewise, the authors are
grateful to CONACYT-Mexico for the fellowships provided to
P. Rangel-Rivera and A. Quiroga-AlmaguerPeer reviewe
Polymerization of ε-caprolactone with degraded PET for its functionalization
Poly(caprolactone) (PCL) was synthesized from the polymerization of ε-caprolactone (CL) with degraded poly(ethylene terephthalate) (PET) for its functionalization using heptamolybdate of ammonium and tin(II) 2-ethylhexanoate, as catalyst and initiator, respectively. Polymerization of CL with bis(2-hydroxyethyl) terephthalate (BHET) was carried out to make a comparison. From the analysis by FTIR, the functional groups of polycaprolactone and degraded PET were identified by FTIR. The chemical shift at 165.59 ppm obtained by NMR corresponded to the chemical bond between the carbonyl of the PCL bound to the -CHCO-CHO of the degraded PET. The number average molar mass of polymer obtained was determined and its chemical structure was proposed. Crystallinity and the temperatures of melting and degradation depended of the mass of degraded PET used in the synthesis. Based on the proposed chemical structure, the synthesized polymer could be used in the preparation of other polymers.We are grateful to Universidad del Papaloapan and Martha Rocio Valencia Estacio, for their assistance on this articl