76 research outputs found
La calculadora analógica de Lagrange para las integrales elípticas
En este artículo se muestra que el modelo esférico de Lagrange para las integrales elípticas es interpretable como un computador analógico. Además del lema fundamental que sustenta la analogía, se presentan ejemplos de cálculo para las amplitudes de la suma y la diferencia de dos amplitudes elípticas dadas. En el computador analógico, estas operaciones se materializan por medio de construcciones con regla y compás esféricos. A lo largo de la presentación, se discuten las ventajas y desventajas del procedimiento propuesto. Al final, se esbozan algunas conclusiones sobre los métodos usados y sobre un posible método híbrido para la aproximación numérica de las amplitudes elípticas
Digital skills, ICTs and students’ needs: a case study in social work degree, University of Zaragoza (Aragón-Spain)
Technological innovations are related to information and communication technologies (ICTs), which in turn have become a fundamental pillar in the field of education. Social work professionals require new approaches to take on the new type of work demanded by the digital society, specializing in research into the innovation of these new forms of action through technology. This article analyses whether university training is in tune with the new skills and abilities required for professional interventions in the twenty-first century. A total of 288 surveys were carried out on 309 students. Each survey consisted of 25 questions on the five digital skills areas. The results indicate that training in digital skills must gain space in university training plans, just as the pandemic became a starting point for the massive use of ICTs. The conclusions point to the importance of improving training in digital competences and skills for future generations of social workers, who, although they are digital natives, will need to know how to use ICTs in their social work
Implementaci?n de herramientas did?cticas y tecnol?gicas para mejorar el nivel de aprendizaje de la trigonometr?a
192 p. Recurso Electr?nicoEl presente trabajo tiene por objeto dar a conocer c?mo el uso de herramientas
did?cticas tecnol?gicas aportan de manera constructiva a la formaci?n de los
estudiantes; esta investigaci?n se llev? a cabo con estudiantes del grado D?cimo de la
instituci?n educativa Colegio Tolimense de la ciudad de Ibagu? con el fin de enfocar
m?s la atenci?n y el inter?s del estudiante hacia el aprendizaje de la trigonometr?a con
cambios en la did?ctica de los profesores del ?rea.
El implementar nuevas herramientas did?cticas y tecnol?gicas en las aulas, surge del
inter?s de observar, conocer y analizar las pr?cticas docentes y de analizar que s? se
incrementa el rendimiento acad?mico en la asignatura de trigonometr?a; es por ello que
la investigaci?n es avalada por la Instituci?n Educativa Colegio Tolimense; la cual
invierte en tecnolog?a en el a?o 2015, haciendo una gran inversi?n y equipando los
salones de los grados d?cimo y once con tableros inteligentes, la sala de sistema con
computadores personales e Internet permanente.
Para alcanzar el objetivo de estudio de esta investigaci?n, se recolect? la informaci?n
pertinente empleando encuestas, aplicando pruebas en las aulas de clase,
entrevistando y observando los comportamientos de estudiantes de grado d?cimo a la
hora de enfrentarse a unas nuevas tecnolog?as para aprender a resolver problemas
trigonom?tricos, en donde se evidenciaran las apreciaciones tanto de estudiantes y
profesores sobre el impacto de usar las herramientas did?cticas para el aprendizaje de
la trigonometr?a.paper is intended to give Hall a meet as the use of educational Technology Tools
constructively contribute to the training of students; this research was carried out with
the Tenth grade students of School College of Tolima in Ibague But in order to focus the
attention and interest of students towards learning trigonometry with changes in the
teaching of Teachers area.
The implement new educational and technological tools in the classroom, it stems from
the interest to observe, learn and analyze teaching practices and analyzing yes
increases academic performance in the subject of trigonometry ; which is why research
is supported by the Educational Institution Tolimense College ; which invests in
technology in 2015 , making a great investment and equipping the halls of the tenth and
eleven degrees with smart boards , the living system for personal computers and
permanent Internet.
To achieve the objective of this research study, the relevant information was collected
using surveys, applying tests in classrooms, interviewing and observing the behavior of
sophomores when faced with a new technology to learn to solve problems trigonometry,
where the findings of both students and teachers about the impact of using the
educational tools for learning trigonometry become apparent.
Key Words: Teaching Tools, Technologies, Learning trigonometry, New Technologies
applied to Education
La calculadora analógica de Lagrange para las integrales elípticas
En este artículo se muestra que el modelo esférico de Lagrange para las integrales elípticas es interpretable como un computador analógico. Además del lema fundamental que sustenta la analogía, se presentan ejemplos de cálculo para las amplitudes de la suma y la diferencia de dos amplitudes elípticas dadas. En el computador analógico, estas operaciones se materializan por medio de construcciones con regla y compás esféricos. A lo largo de la presentación, se discuten las ventajas y desventajas del procedimiento propuesto. Al final, se esbozan algunas conclusiones sobre los métodos usados y sobre un posible método híbrido para la aproximación numérica de las amplitudes elípticas
Los factores ambientales, luz y temperatura, modifican la formación de la biopelícula en Pseudomonas syringae pv. syringae.
Comunicación a congreso en formato pósterLas biopelículas bacterianas están formadas por agregados celulares embebidos en una matriz
extracelular de producción propia, formada principalmente por exopolisacáridos (EPS), proteínas
y ADN extracelular. Existen datos recientes que sugieren que entre el 40-80% de las bacterias
se encuentran formando biopelículas en la naturaleza, y que la formación de las biopelículas
se ve afectada por factores ambientales. Pseudomonas syringae pv. syringae (Pss) es una
bacteria fitopatógena causante de la necrosis apical del mango (NAM), enfermedad limitante
de la producción de este cultivo en la región mediterránea. En Pss se ha descrito una conexión
entre factores ambientales y la incidencia y severidad de la NAM, jugando los EPS celulosa y
uno tipo-Psl, un papel relevante en la transición entre un estilo de vida epífito o patogénico. En
este trabajo, se ha analizado el papel de algunos factores ambientales relevantes como son la
luz y la temperatura en la formación de la biopelícula in vitro en una colección de cepas de Pss
aisladas de mango. Los resultados obtenidos sugieren que la temperatura y particularmente la
luz pueden influir en la formación de las biopelículas a través de la biosíntesis de los EPS, principalmente
celulosa. Además, también se ha observado como niveles más bajos de producción
de celulosa podrían estar asociados con una mayor virulencia. Estos resultados indican que los
EPS, y principalmente celulosa juegan un papel clave en la ecología de Pss sobre la planta de
mango a través de la formación de la biopelícula.Este trabajo ha sido financiado por Proyectos de Excelencia de la Junta de Andalucía (P12-
AGR-1473), cofinanciado con ayudas a proyectos I+D+i en el marco del Programa Operativo
FEDER Andalucía (UMA20-FEDERJA-060), y la Universidad de Málaga.
Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Type III Secretion System Genes of Dickeya dadantii 3937 Are Induced by Plant Phenolic Acids
Background: Dickeya dadantii is a broad-host range phytopathogen. D. dadantii 3937 (Ech3937) possesses a type III secretion system (T3SS), a major virulence factor secretion system in many Gram-negative pathogens of plants and animals. In Ech3937, the T3SS is regulated by two major regulatory pathways, HrpX/HrpY-HrpS-HrpL and GacS/GacA-rsmB-RsmA pathways. Although the plant apoplast environment, low pH, low temperature, and absence of complex nitrogen sources in media have been associated with the induction of T3SS genes of phytobacteria, no specific inducer has yet been identified. Methodology/Principal Findings: In this work, we identified two novel plant phenolic compounds, o-coumaric acid (OCA) and t-cinnamic acid (TCA), that induced the expression of T3SS genes dspE (a T3SS effector), hrpA (a structural protein of the T3SS pilus), and hrpN (a T3SS harpin) in vitro. Assays by qRT-PCR showed higher amounts of mRNA of hrpL (a T3SS alternative sigma factor) and rsmB (an untranslated regulatory RNA), but not hrpS (a s 54-enhancer binding protein) of Ech3937 when these two plant compounds were supplemented into minimal medium (MM). However, promoter activity assays using flow cytometry showed similar promoter activities of hrpN in rsmB mutant Ech148 grown in MM and MM supplemented with these phenolic compounds. Compared with MM alone, only slightly higher promoter activities of hrpL were observed in bacterial cells grown in MM supplemented with OCA/TCA. Conclusion/Significance: The induction of T3SS expression by OCA and TCA is moderated through the rsmB-Rsm
Jasmonate-dependent modifications of the pectin matrix during potato development function as a defense mechanism targeted by Dickeya dadantii virulence factors
The plant cell wall constitutes an essential protection barrier against pathogen attack. In addition, cell-wall disruption leads to accumulation of jasmonates (JAs), which are key signaling molecules for activation of plant inducible defense responses. However, whether JAs in return modulate the cell-wall composition to reinforce this defensive barrier remains unknown. The enzyme 13-allene oxide synthase (13-AOS) catalyzes the first committed step towards biosynthesis of JAs. In potato (Solanum tuberosum), there are two putative St13-AOS genes, which we show here to be differentially induced upon wounding. We also determine that both genes complement an Arabidopsis aos null mutant, indicating that they encode functional 13-AOS enzymes. Indeed, transgenic potato plants lacking both St13-AOS genes (CoAOS1/2 lines) exhibited a significant reduction of JAs, a concomitant decrease in wound-responsive gene activation, and an increased severity of soft rot disease symptoms caused by Dickeya dadantii. Intriguingly, a hypovirulent D. dadantii pel strain lacking the five major pectate lyases, which causes limited tissue maceration on wild-type plants, regained infectivity in CoAOS1/2 plants. In line with this, we found differences in pectin methyl esterase activity and cell-wall pectin composition between wild-type and CoAOS1/2 plants. Importantly, wild-type plants had pectins with a lower degree of methyl esterification, which are the substrates of the pectate lyases mutated in the pel strain. These results suggest that, during development of potato plants, JAs mediate modification of the pectin matrix to form a defensive barrier that is counteracted by pectinolytic virulence factors from D. dadantii
Differentiation of mouse bone marrow derived stem cells toward microglia-like cells
<p>Abstract</p> <p>Background</p> <p>Microglia, the macrophages of the brain, have been implicated in the causes of neurodegenerative diseases and display a loss of function during aging. Throughout life, microglia are replenished by limited proliferation of resident microglial cells. Replenishment by bone marrow-derived progenitor cells is still under debate. In this context, we investigated the differentiation of mouse microglia from bone marrow (BM) stem cells. Furthermore, we looked at the effects of FMS-like tyrosine kinase 3 ligand (Flt3L), astrocyte-conditioned medium (ACM) and GM-CSF on the differentiation to microglia-like cells.</p> <p>Methods</p> <p>We assessed <it>in vitro-</it>derived microglia differentiation by marker expression (CD11b/CD45, F4/80), but also for the first time for functional performance (phagocytosis, oxidative burst) and <it>in situ </it>migration into living brain tissue. Integration, survival and migration were assessed in organotypic brain slices.</p> <p>Results</p> <p>The cells differentiated from mouse BM show function, markers and morphology of primary microglia and migrate into living brain tissue. Flt3L displays a negative effect on differentiation while GM-CSF enhances differentiation.</p> <p>Conclusion</p> <p>We conclude that <it>in vitro-</it>derived microglia are the phenotypic and functional equivalents to primary microglia and could be used in cell therapy.</p
Genome-Wide Identification of HrpL-Regulated Genes in the Necrotrophic Phytopathogen Dickeya dadantii 3937
BACKGROUND: Dickeya dadantii is a necrotrophic pathogen causing disease in many plants. Previous studies have demonstrated that the type III secretion system (T3SS) of D. dadantii is required for full virulence. HrpL is an alternative sigma factor that binds to the hrp box promoter sequence of T3SS genes to up-regulate their expression. METHODOLOGY/PRINCIPAL FINDINGS: To explore the inventory of HrpL-regulated genes of D. dadantii 3937 (3937), transcriptome profiles of wild-type 3937 and a hrpL mutant grown in a T3SS-inducing medium were examined. Using a cut-off value of 1.5, significant differential expression was observed in sixty-three genes, which are involved in various cellular functions such as type III secretion, chemotaxis, metabolism, regulation, and stress response. A hidden Markov model (HMM) was used to predict candidate hrp box binding sites in the intergenic regions of 3937, including the promoter regions of HrpL-regulated genes identified in the microarray assay. In contrast to biotrophic phytopathgens such as Pseudomonas syringae, among the HrpL up-regulated genes in 3937 only those within the T3SS were found to contain a hrp box sequence. Moreover, direct binding of purified HrpL protein to the hrp box was demonstrated for hrp box-containing DNA fragments of hrpA and hrpN using the electrophoretic mobility shift assay (EMSA). In this study, a putative T3SS effector DspA/E was also identified as a HrpL-upregulated gene, and shown to be translocated into plant cells in a T3SS-dependent manner. CONCLUSION/SIGNIFICANCES: We provide the genome-wide study of HrpL-regulated genes in a necrotrophic phytopathogen (D. dadantii 3937) through a combination of transcriptomics and bioinformatics, which led to identification of several effectors. Our study indicates the extent of differences for T3SS effector protein inventory requirements between necrotrophic and biotrophic pathogens, and may allow the development of different strategies for disease control for these different groups of pathogens
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