1,071 research outputs found
Econometric analysis of the industrial growth determinants in Colombia
An econometric study is carried out using a panel data model with fixed effects to identify the industrial development determinants in Colombia during the term 2005–2015. The database used in the study corresponds to World Bank and the Colombian state. The determinants of industrial growth identified at the theoretical level that allow the enhancement of productive capacities to face foreign competition in Colombia are: innovation; networks of innovations and knowledge among companies and organizations; the interest rate; the capital-product ratio, the unit labor cost; and the exchange rate. The amount invested in scientific, technological and innovation activities by industrial group is the only variable that is not significant in the model
Evaluación exploratoria del cultivo de la caña de azúcar (Saccharum spp.): Enfoque del paisaje del desempeño
Objective: Perform an exploratory analysis of sugar cane (Saccharum spp.) cultivation (CCA) through a performance landscape (PD) approach including an analytical description of the food balance sheet and performance indicators.
Design/methodology/approach: Three main dataset were constructed by using different statistic information systems, including eight performance variables-production, exports, imports, consumption per capita, acreage, production value, yield, farm-gate price, revenue per hectare on SCC, sugar products and 82 perennial crops (PC). Analytical description was based on municipality scale and temporal series (2003-2017). PL focused on the assessment of percentage proportion between SCC and PC, considering acreage and production value.
Results: Mexican consumption of sugar equivalent was decreasing in spite of its high consumption value (37.5 kg person-1 y-1). For 15 years, production of SCC and its acreage have gradually increased. Since farm gate prices showed a real increment (34%), production value and revenue per hectare (MX55676 ha-1) also revealed growth. In contrast, yield (84 Mg ha-1) stagnated (5%). PL assessment identified 94 municipalities where SCC dominates acreage and production value.
Limitations on study/implications: Descriptive analysis is powerful to characterize systems and shed light on improving understanding on the identification of driving factors, selecting a core dataset to measure their impacts and seeking for causality relationships.
Findings/conclusions: The integration of different information sources clarify the interrelations between economic, social and environmental themes, particularly in agriculture.Objetivo: Realizar un análisis exploratorio del cultivo de la caña de azúcar (CCA) mediante un enfoque de paisaje del desempeño (PD) incluyendo una descripción analítica de hoja balance alimentaria e indicadores de desempeño.
Diseño/metodología/aproximación: Tres tablas de datos fueron construidas usando diferentes sistemas de información estadística (SIE) e incluyendo ocho variables –producción, exportaciones, importaciones, consumo per cápita, superficie, valor de la producción (VP), precio pagado al productor (PP) e ingreso unitario sobre el CCA, productos de azúcar y 82 cultivos perennes (SPAP). La descripción analítica fue basada a nivel municipal y una serie temporal (2003-2017). A través del PD, se evaluó el porcentaje de proporción entre el CCA y los SPAP, considerando superficie y el VP.
Resultados: El consumo de azúcar equivalente está disminuyendo (37.5 kg persona-1 año-1). Las exportaciones incrementaron y representaron 40% de la producción; las importaciones crecieron moderadamente, pero existe suficiencia alimentaria. Por 15 años, la producción y superficie del CCA ha crecido gradualmente. Los PP mostraron un crecimiento real (34%), en consecuencia, también el VP y el ingreso unitario ($ 55,676 ha-1). En contraste, el rendimiento (84 Mg ha-1) está estancado (5%). La evaluación del PD identificó 94 municipios donde el CCA domina superficie y VP.
Limitaciones del estudio/implicaciones: El análisis descriptivo es una herramienta útil para caracterizar sistemas y proporciona mayor claridad sobre la identificación de factores de cambio, selección de datos centrales, así como de facilitar la búsqueda de relaciones causales. Este tipo de estudios, aporta información a temas económicos de gran visión. sin embargo; en lo social, se carece de relaciones vinculantes entre productores e instituciones que concentran los datos, además de que no contiene información ambiental (clima, suelo, etc.) y de manejo agronómico del cultivo de la caña de azúcar en cada estado de la república mexicana.
Hallazgos/conclusiones: La integración de diferentes SIE clarifica las interrelaciones entre los temas económicos, particularmente en agricultur
Design, Synthesis and Evaluation of 2,4- Diaminoquinazoline Derivatives as Potential Tubulin Polymerization Inhibitors
Microtubules are highly dynamic polymers composed of α- and β- tubulin proteins that have been shown to be potential therapeutic targets for the development of anticancer drugs. Currently, a wide variety of chemically diverse agents that bind to β- tubulin have been reported. Nocodazole (NZ) and colchicine (COL) are well- known tubulin- depolymerizing agents that have close binding sites in the β- tubulin. In this study, we designed and synthesized a set of nine 2,4- diaminoquinazoline derivatives that could occupy both NZ and COL binding sites. The synthesized compounds were evaluated for their antiproliferative activities against five cancer cell lines (PC- 3, HCT- 15, MCF- 7, MDA- MB- 231, and SK- LU- 1), a noncancerous one (COS- 7), and peripheral blood mononuclear cells (PBMC). The effect of compounds 4- e and 4- i on tubulin organization and polymerization was analyzed on the SK- LU- 1 cell line by indirect immunofluorescence, western blotting, and tubulin polymerization assays. Our results demonstrated that both compounds exert their antiproliferative activity by inhibiting tubulin polymerization. Finally, a possible binding pose of 4- i in the NZ/COL binding site was determined by using molecular docking and molecular dynamics (MD) approaches. To our knowledge, this is the first report of non- N- substituted 2,4- diaminoquinazoline derivatives with the ability to inhibit tubulin polymerization.More is not always better: A set of nine 2,4- diaminoquinazoline derivatives were evaluated for their ability to inhibit tubulin polymerization by using immunofluorescence staining analysis, western blotting, tubulin polymerization assays, and molecular dynamics simulations. Our study provides valuable insights into the design of 2,4- diaminoquiazoline compounds as tubulin polymerization inhibitors for the treatment of lung and breast cancer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163403/3/cmdc202000185-sup-0001-misc_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163403/2/cmdc202000185_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163403/1/cmdc202000185.pd
Antioxidant and hypoglycemic effects of watercress (Nasturtium officinale) extracts in diabetic rats
Background: Watercress is a semi-aquatic plant used in traditional medicine to treat various ailments, such as flu, cough, avitaminosis, and anorexia; it is also used as a diuretic and for hypoglycemia treatment in diabetes. In this study, we report the antioxidant and hypoglycemic activity of orally administered aqueous (WAQE), acetonic (WAE), and alcoholic (WOHE) watercress extracts. The effect of subchronic administration of watercress extracts on oxidative stress was also studied.Materials and Methods: WAQE, WAE, and WOHE were obtained and administered orally. Alloxan (200 mg/kg) and streptozotocin (60 mg/kg) were applied to induce hyperglycemia in male Wistar rats. Phenolic and flavonoid content, as well as antioxidant activity of the extracts were measured. The acute and subchronic effects (8 weeks) of WAQE were evaluated. The activity of antioxidant enzymes levels of malondialdehyde, hepatic enzyme markers in the serum, and renal function markers, were assessed. Histopathological evaluation of the pancreas, kidney, and liver was performed using hematoxylin-eosin staining.Results: Watercress extracts have high concentrations of phenols, polyphenols, and flavonoids, in addition to a very high antioxidant effect. The hypoglycemic effect of WAQE upon acute administration was 76.6% higher than that of insulin. When administered chronically, glucose levels were normalized on the third week up to the eighth week. Furthermore, the antioxidant enzymes and biochemical parameters improved.Conclusion: WAQE administration to diabetic rats reduced oxidative stress damage and decreased glucose levels. This study supports the use of this plant for the treatment of diabetes.Keywords: Antioxidant, Diabetes, Watercress (Nasturtium officinale), Oxidative stress, Pancrea
Magnification endoscopy to detect dysplastic aberrant crypt foci in Mexican patients with high risk for colorectal cancer
Non-invasive Estimation of Atrial Fibrillation Driver Position With Convolutional Neural Networks and Body Surface Potentials
[EN] Atrial fibrillation (AF) is characterized by complex and irregular propagation patterns, and AF onset locations and drivers responsible for its perpetuation are the main targets for ablation procedures. ECG imaging (ECGI) has been demonstrated as a promising tool to identify AF drivers and guide ablation procedures, being able to reconstruct the electrophysiological activity on the heart surface by using a non-invasive recording of body surface potentials (BSP). However, the inverse problem of ECGI is ill-posed, and it requires accurate mathematical modeling of both atria and torso, mainly from CT or MR images. Several deep learning-based methods have been proposed to detect AF, but most of the AF-based studies do not include the estimation of ablation targets. In this study, we propose to model the location of AF drivers from BSP as a supervised classification problem using convolutional neural networks (CNN). Accuracy in the test set ranged between 0.75 (SNR = 5 dB) and 0.93 (SNR = 20 dB upward) when assuming time independence, but it worsened to 0.52 or lower when dividing AF models into blocks. Therefore, CNN could be a robust method that could help to non-invasively identify target regions for ablation in AF by using body surface potential mapping, avoiding the use of ECGI.This work has been partially supported by: Ministerio de Ciencia e Innovacion (PID2019-105032GB-I00), Instituto de Salud Carlos III, and Ministerio de Ciencia, Innovacion y Universidades (supported by FEDER Fondo Europeo de Desarrollo Regional PI17/01106 and RYC2018-024346B-750), Consejeria de Ciencia, Universidades e Innovacion of the Comunidad de Madrid through the program RIS3 (S-2020/L2-622), EIT Health (Activity code 19600, EIT Health is supported by EIT, a body of the European Union) and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 860974.Cámara-Vázquez, MÁ.; Hernández-Romero, I.; Morgado-Reyes, E.; Guillem Sánchez, MS.; Climent, AM.; Barquero-Pérez, O. (2021). Non-invasive Estimation of Atrial Fibrillation Driver Position With Convolutional Neural Networks and Body Surface Potentials. Frontiers in Physiology. 12:1-11. https://doi.org/10.3389/fphys.2021.733449S1111
Effect of Porcine circovirus 2 (PCV-2) maternally derived antibodies on performance and PCV-2 viremia in vaccinated piglets under field conditions
Background: Nowadays, the most common presentation of PCV-2 is the subclinical infection in piglets after weaning. The success of PCV-2 vaccination is associated with the control of the clinical disease as well as the improvement of production parameters. In consequence, the objective of the present study was to analyse the effect of PCV-2 maternally derived antibody (MDA) levels on vaccine efficacy in piglets vaccinated at three weeks of age with a commercial PCV-2 subunit vaccine. The study was performed analysing a database with 6112 wean-to-slaughter piglets from 4 different European regions. Results: Results showed that the use of the vaccine was able to decrease the PCV-2 viremia calculated as area under the curve (AUC = 60.29 ± 3.73), increase average daily weight gain (ADWG = 0.65 ± 0.01 kg/day) and reduce mortality (7%) in vaccinated piglets compared to non-vaccinated ones (AUC of 198.27 ± 6.14, 0.62 ± 0.01 kg/day and 11% respectively). The overall difference of ADWG between both groups was close to 30 g per day (p < 0.05), also when they were split for low and high levels of MDA titres. Moreover, the animals with the highest ADWG were observed in the group of piglets vaccinated with high or extremely high antibody titres (0.66 and 0.65 kg/day respectively). Considering only animals with extremely high antibody titres, both study groups performed similar, however there was a numerical difference of 10 g/day in favour of vaccinated piglets. Likewise, lack of correlation between ADWG and MDA was observed suggesting that no maternal antibody interference was present with the tested vaccine because the vaccinated animals grew faster compared to unvaccinated control animals, regardless of the level of maternal antibodies present at the time of vaccination. Conclusions: The results of the present study demonstrated that the MDA against PCV-2 transferred through the colostrum intake has a protective effect against this viral infection. The vaccine used in the present study (Ingelvac CircoFLEX®) was effective when applied at three weeks of age and was not affected by the level of MDA at the time of vaccination
Discharge of repulsive grains from a silo: experiments and simulations
In granular matter, sliding friction and collisions among grains are fundamental mechanisms of energy dissipation that determine the particles dynamics. Here we consider an unconventional granular system composed of magnetic repelling grains confined in a two dimensional cell that interact only through their magnetic field. The repulsive interaction prevents contact among grains and therefore produces a different dynamics compared to the dynamics of classical granular systems. In particular, we present experiments and simulations on the discharge of this repulsive granular medium from a silo. The results reveal an inverted density profile and a plug-flow through the aperture that contrast with the dynamics displayed by contacting grains. Moreover, the simulations allow to estimate the friction coefficient generated by the lateral confinement
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