COVID-19. Higher Education and Educational Technology Actions Performed to Reduce the Negative Effects

Beatriz Angélica Toscano de laTorre,Juan Contreras-Castillo,Norma Barón-Ramírez APEC국제교육협력원 2020 Asia-Pacific Cybereducation Journal Vol.16 No.2

This essay analyzes the impact of COVID-19 in higher education based on national policies implemented during the current outbreak. Additionally, it enlists and discusses the proposed strategies developed to support higher education in a post-pandemic scenario based on educational and political perspectives.

Alcohol dehydrogenase 1 participates in the Crabtree effect and connects fermentative and oxidative metabolism in the Zygomycete Mucor circinelloides

Rosa Angélica Rangel-Porras,Sharel P. Díaz-Pérez,Juan Manuel Mendoza-Hernández,Pamela Romo-Rodríguez,Viridiana Alejandre-Castañeda,Marco I Valle-Maldonado,Juan Carlos Torres-Guzmán,Gloria Angélica Gon 한국미생물학회 2019 The journal of microbiology Vol.57 No.7

Mucor circinelloides is a dimorphic Zygomycete fungus that produces ethanol under aerobic conditions in the presence of glucose, which indicates that it is a Crabtree-positive fungus. To determine the physiological role of the alcohol dehydrogenase (ADH) activity elicited under these conditions, we obtained and characterized an allyl alcohol-resistant mutant that was defective in ADH activity, and examined the effect of adh mutation on physiological parameters related to carbon and energy metabolism. Compared to the Adh+ strain R7B, the ADH-defective (Adh-) strain M5 was unable to grow under anaerobic conditions, exhibited a considerable reduction in ethanol production in aerobic cultures when incubated with glucose, had markedly reduced growth capacity in the presence of oxygen when ethanol was the sole carbon source, and exhibited very low levels of NAD+-dependent alcohol dehydrogenase activity in the cytosolic fraction. Further characterization of the M5 strain showed that it contains a 10-bp deletion that interrupts the coding region of the adh1 gene. Complementation with the wild-type allele adh1+ by transformation of M5 remedied all the defects caused by the adh1 mutation. These findings indicate that in M. circinelloides, the product of the adh1 gene mediates the Crabtree effect, and can act as either a fermentative or an oxidative enzyme, depending on the nutritional conditions, thereby participating in the association between fermentative and oxidative metabolism. It was found that the spores of M. circinelloides possess low mRNA levels of the ethanol assimilation genes (adl2 and acs2), which could explain their inability to grow in the alcohol.

Postharvest application effect of agave fructans on anthracnose disease, defense-related enzyme activities, and quality attributes in avocado fruit

Esther Angélica Cuéllar-Torres,Selene Aguilera-Aguirre,Miriam del Carmen Bañuelos-González,Luis Ángel Xoca-Orozco,Rosa Isela Ortiz-Basurto,Efigenia Montalvo-González,Julio Vega-Arreguín,Martina Alejan 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.11

The postharvest application of high degree of polymerization agave fructans (HDPAF) was tested, evaluating anthracnose disease, defense-related enzyme activities, and quality attributes in avocado fruit. Application of a 20% HDPAF solution showed a reduction in anthracnose severity (60%) and incidence (34%) compared to the other concentrations evaluated and the water-treated control. Polyphenoloxidase activity increased 4.6 times more 24 h after treatment. In addition, peroxidase and phenylalanine ammonia-lyase enzyme activity was 4.34 and 1.7 times higher than the control at 0.5 h after treatment. HDPAF retrieves the deceleration of both firmness loss and physiological weight loss compared to the control. Regarding quality parameters such as color, pH, total soluble solids, and titratable acidity, no significant differences were observed between treatments compared to the control; therefore, these parameters were not negatively affected by HDPAF treatments, but a positive effect on the induction of the defense system is shown.

A New Mixture Criterion for the Improvement of the Compressive Strength of Adobe Using Zeolite as Stabilizer

Rosa Angélica Lara-Ojeda,Juana María Miranda-Vidales,Lilia Narváez-Hernández,Juan Manuel Lozano de Poo 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.8

The use of zeolite as a stabilizer for adobe has proven to have the ability to improve its physical and chemical properties. This is shown in the positive results in terms of strength gain and water absorption resistance in adobe blocks. In this work, an investigation was carried out to evaluate the use of zeolite as adobe stabilizer. The adobes were made with two different types of soil with different content of zeolite (5, 10, 15, 20% by weight) maintaining the zeolite-lime ratio 1:1. The samples were tested on compressive strength and water absorption. The deterioration of the adobes was analyzed under conditions of extreme humidity. The results of this study revealed that adobe behavior is influenced by the synergistic relationship between soil, zeolite and lime, showing significant changes in compressive strength even under extreme humidity conditions. It was also observed that the chemical composition of the soil influenced the development of the pozzolanic reaction. The stabilization of adobes with 15% of zeolite showed the best mechanical behavior, before and after deterioration assay. Hence, zeolite promises to be a good alternative as a stabilizer in adobe construction systems.

Jurisdiction of the Arbitral Tribunal in the Case of Multiple Contracts

James Otis Rodner,Angélica Marcano 한국중재학회 2014 중재연구 Vol.24 No.3

The foundation of the arbitration jurisdiction is the arbitration agreement entered into by the parties to a contract. Usually, only the signatory parties to a contract and the disputes arising from a contract that includes an arbitration clause or to which the arbitration clause relates are the ones that can be submitted to arbitration. This article discusses some of the arguments for extending the arbitration clause in complex arbitrations, that is, in those cases where there are more than two parties, more than two contracts or more than two parties and contracts. Particularly, this paper addresses multiple contract arbitration when the contracts are related. One of the arguments used by the arbitral tribunal for the extension of jurisdiction is the existence of a link between the contracts. Additional arguments include implied consent, participation in the negotiation and performance of a contract and good faith. The article also discusses some of the typical cases of linked contracts in many civil law countries, such as subcontracts, third party beneficiaries and standard terms of contracts, from which arbitral jurisdictions problems may arise. Finally, special attention is given to Article 14 of the 2008 Peruvian Arbitration Law as the first provision in an arbitration law in Latin America that extends the arbitration agreement to non-signatory parties using for this a mixed approach.

Digital platforms and technologies in preschool education in Portugal: Perceptions of preschool teachers

Valadas Sandra T,Fernandes Preciosa,Monteiro Angélica,Figueiredo Carla,Marinho Paulo,Vilhena Carla The Pacific Early Childhood Education Research Ass 2023 Asia-Pacific journal of research in early childhoo Vol.17 No.3

This paper analyses the perceptions of Portuguese preschool teachers regarding the use of Digital Platforms and Technologies (DPTs) in preschool education, focusing on which DPTs are mostly used and with what aims, and on constraints felt in its use. The paper draws on data collected in a larger research project regarding the use of DPTs ) in schools, using a survey questionnaire applied in schools from the Portuguese mainland during 2020, answered by 75 preschool teachers. Results show that preschool teachers mostly use Microsoft Office applications and communication platforms to communicate with peers and families, and for administrative and pedagogical tasks. The constraints felt are associated with the need for training which would allow these professionals to use DPTs more effectively, and the need to upgrade and ensure technical maintenance of the existing equipment.

Gender inequalities in the sale of handmade corn tortillas in central Mexican markets: before and during the COVID-19 pandemic

Cárdenas-Marcelo Alma Lili,Espinoza-Ortega Angélica,Vizcarra-Bordi Ivonne 한국식품연구원 2022 Journal of Ethnic Foods Vol.9 No.-

The objective of this study was to analyze gender inequalities and intersectionality experienced by rural-indigenous women who produce and sell native maize tortillas at three different markets-tianguis in central Mexico, facing the COVID-19 pandemic.This was a qualitative study based on 36 in-depth interviews before pandemic (2018), as well as 16 interviews during pandemic (2020) of women engaged in this work.Making corn tortillas by hand is one of the culturally assigned gender roles in the indigenous population of the Mazahua region, which is why their sale in local markets as a female strategy to have access to income for household sustenance has been widely by the communities. The configuration of the different market-space for the sale of handmade tortillas, reflects the inequalities of gender and intersectionality (ethnicity, class, age, family life cycle and education levels). The women in conditions of poverty, landlessness, and with school-age children, have met greater disadvantages in continuing to sell tortillas in the face of the experience of pandemic restrictions.The women who were already disadvantaged by their intersectional relationships continue to experience the same inequalities that conditioned their position in the marketplaces before the pandemic, sustaining a marginal but constant market.

Polylactide Nanofibers Loaded with Vitamin B6 and Polyphenols as Bioactive Platform for Tissue Engineering

Elena Llorens,Luis J. del Valle,Angélica Díaz,María T. Casas,Jordi Puiggalí 한국고분자학회 2013 Macromolecular Research Vol.21 No.7

Electrospun polylactide nanofibers loaded with different antioxidants (i.e. vitamin B6 in pyridoxine and pyridoxal form, p-coumaric acid and caffeic acid) are prepared from N,N-dimethylformamide/dimethylsulfoxide solutions. Morphology, structure and crystallinity of the nanofibers are evaluated by transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction and differential scanning calorimetry (DSC)techniques. Fibers are highly amorphous but able to crystallize easily due to the high molecular orientation induced by the electrospinning process. The drug molecules are incorporated into the polymeric matrix or formed isolated crystals. A fast release of loaded drug occurs within the first 8 h in hydrophobic medium; but, a slow and sustained release during several days occurs in a hydrophilic medium. Cell attachment on the loaded scaffolds was unaffected by the incorporation of the antioxidants. In contrast, cell proliferation increases with high antioxidative activity against free radicals responsible for cell damage. These new electrospun scaffolds provide high protection of cells against oxidative stress and resulting in innovative 3D fibrous platforms for tissue growth and proliferation.

Effect of intracanal medications on the interfacial properties of reparative cements

Andrea Cardoso Pereira,Mariana Valerio Pallone,Marina Angélica Marciano,Karine Laura Cortellazzi,Marcos Frozoni,Brenda P. F. A. Gomes,José Flávio Affonso de Almeida,Adriana de Jesus Soares 대한치과보존학회 2019 Restorative Dentistry & Endodontics Vol.44 No.2

Objectives: The purpose of the present study was to evaluate the effect of calcium hydroxide with 2% chlorhexidine gel (HCX) or distilled water (HCA) compared to triple antibiotic paste (TAP) on push-out bond strength and the cement/dentin interface in canals sealed with White MTA Angelus (WMTA) or Biodentine (BD). Materials and Methods: A total of 70 extracted human lower premolars were endodontically prepared and randomly divided into 4 groups according to the intracanal medication, as follows: group 1, HCX; group 2, TAP; group 3, HCA; and group 4, control (without intracanal medication). After 7 days, the medications were removed and the cervical third of the specimens was sectioned into five 1-mm sections. The sections were then sealed with WMTA or BD as a reparative material. After 7 days in 100% humidity, a push-out bond strength test was performed. Elemental analysis was performed at the interface, using energy-dispersive spectroscopy. The data were statistically analyzed using analysis of variance and the Tukey test (p < 0.05). Results: BD presented a higher bond strength than WMTA (p < 0.05). BD or WMTA in canals treated with calcium hydroxide intracanal medications had the highest bond strength values, with a statistically significant difference compared to TAP in the WMTA group (p < 0.05). There were small amounts of phosphorus in samples exposed to triple antibiotic paste, regardless of the coronal sealing. Conclusions: The use of intracanal medications did not affect the bond strength of WMTA and BD, except when TAP was used with WMTA.

Low-Scale Expression and Purification of an Active Putative Iduronate 2-Sulfate Sulfatase-Like Enzyme from Escherichia coli K12

Edwin David Morales-Álvarez,Claudia Marcela Rivera-Hoyos,Angélica María Baena-Moncada,Patricia Landázuri,Raúl A. Poutou-Piñales,Homero Sáenz-Suárez,Luis A. Barrera,Olga Y. Echeverri-Peña 한국미생물학회 2013 The journal of microbiology Vol.51 No.2

The sulfatase family involves a group of enzymes with a large degree of similarity. Until now, sixteen human sulfatases have been identified, most of them found in lysosomes. Human deficiency of sulfatases generates various genetic disorders characterized by abnormal accumulation of sulfated intermediate compounds. Mucopolysaccharidosis type II is characterized by the deficiency of iduronate 2-sulfate sulfatase (IDS), causing the lysosomal accumulation of heparan and dermatan sulfates. Currently, there are several cases of genetic diseases treated with enzyme replacement therapy, which have generated a great interest in the development of systems for recombinant protein expression. In this work we expressed the human recombinant IDS-Like enzyme (hrIDS-Like) in Escherichia coli DH5α. The enzyme concentration revealed by ELISA varied from 78.13 to 94.35 ng/ml and the specific activity varied from 34.20 to 25.97 nmol/h/mg. Western blotting done after affinity chromatography purification showed a single band of approximately 40 kDa, which was recognized by an IgY polyclonal antibody that was developed against the specific peptide of the native protein. Our 100 ml-shake-flask assays allowed us to improve the enzyme activity seven fold,compared to the E. coli JM109/pUC13-hrIDS-Like system. Additionally, the results obtained in the present study were equal to those obtained with the Pichia pastoris GS1115/pPIC-9-hrIDS-Like system (3 L bioreactor scale). The system used in this work (E. coli DH5α/pGEX-3X-hrIDS-Like)emerges as a strategy for improving protein expression and purification, aimed at recombinant protein chemical characterization,future laboratory assays for enzyme replacement therapy, and as new evidence of active putative sulfatase production in E. coli.