736 research outputs found
Activity of Ricinus communis (Euphorbiaceae) against Spodoptera frugiperda (Lepidoptera: Noctuidae)
One of the most studied plant species with insecticidal properties is the castor bean Ricinus communis. However, its activity against Spodoptera frugiperda is unclear. Therefore, to determinate the insecticidal and insectistatic activities of methanol, hexane and ethyl acetate extracts of the seeds and leaves of R. communis, castor oil and ricinine were tested at different concentrations against S. frugiperda. This study demonstrated for the first time, that the castor oil and ricinine are active ingredients of R. communis that acts against S. frugiperda and that each of the seed extracts exhibited better insecticidal and insectistatic activity than the leaf extracts. The half maximum larvae viability concentration (LVC50) were 0.38 × 103 ppm for the ricinine, 0.75 × 103 ppm for a methanol extract ofseeds, 1.97 × 103 ppm for an ethyl acetate seed extract, 2.69×103 ppm for the castor oil, 4.83 × 103 ppm for a methanol extract of leaves, 5.07 × 103 ppm for an ethyl acetate extract of leaves, 9.95 × 103 ppm fora hexane extract of seeds and 10.01 × 103 ppm for a hexane extract of leaves
CARACTERIZACIÓN MOLECULAR DEL AGENTE CAUSAL DE LA SECADERA DEL GLADIOLO (Gladiolus grandiflorus HORT)
The objective of this study was the molecular characterization of the causal agent of the gladiolus drier (Gladiolus grandiflorus Hort). In Villa Guerrero, Estado de México, sick gladiolus plants were collected and isolates of the Fusarium genus were obtained to produce monospore cultures; the conidia were stored in glycerol 25 % at -70 °C, and for their molecular characterization the extraction of nucleic acids was made with the Cenis (1992) protocol. For the polymerase chain reaction, the elongation factor gene and the gene that codifies for calmoduline were used. The sequences obtained were compared with F. sterilihyphosum, F. circinatum, F. pseudocircinatum and F. mexicanum, because they share the character of rolled hyphae. F. oxysporum and F. oxysporum f. sp. gladioli were used because of their antecedents in the crop. The phylogenetic analysis was carried out for maximum parsimony and maximum authenticity, observing that the Fusarium species isolated from gladiolus was not associated with any of the other species, which were grouped according to their morphological and molecular characteristics, suggesting that the organism isolated is an unreported new species of Fusarium.El objetivo del presente estudio fue la caracterización molecular del agente causal de la secadera en gladiola (Gladiolus grandiflorus Hort). En Villa Guerrero, Estado de México, se recolectaron plantas de gladiola enfermas y obtuvieron aislamientos del género Fusarium, para producir cultivos monospóricos; los conidios se almacenaron en glicerol 25 % a -70 °C, y para su caracterización molecular se hizo la extracción de ácidos nucleicos con el protocolo de Cenis (1992). Para la reacción en cadena de la polimerasa se utilizó el gen factor de elongación y el gen que codifica para calmodulina. Las secuencias obtenidas se compararon con F. sterilihyphosum, F. circinatum, F. pseudocircinatum y F. mexicanum; por ser las que comparten el carácter de hifas enrolladas. F. oxysporum y F. oxysporum f. sp. gladioli se utilizaron por sus antecedentes en el cultivo. El análisis filogenético se hizo para máxima parsimonia y máxima verosimilitud, observando que la especie de Fusarium aislada de gladiola no se asoció con ninguna de las otras especies, las cuales se agruparon de acuerdo a sus características morfológicas y moleculares, sugiriendo que organismo aislado es una nueva especie de Fusarium no reportada
Anti-inflammatory activity of
The anti-inflammatory activity of the chloroform, methanol and aqueous extracts of Wigandia urens and Acalypha alopecuroides were investigated on carrageenan-induced paw edema at doses of 400 mg/kg. The three extracts of W. urens, and the aqueous extract of A. alopecuroides caused significantinhibition of the edema (58.1±6.5% and 63.5±5.4%, respectively). Indomethacin was used as positive control (8 mg/kg), and inhibited edema by 66.3±5.2%. The methanol extract of W. urens and the aqueous extract of A. alopecuroides, at doses of 200 mg/kg, inhibited pellet implantation-induced granuloma formation by 69.4±6.5 and 70.6±6.6%, respectively. These levels of inhibition are higher than those exhibited by naproxen at doses of 50 mg/kg (46.1±7.1%). Both extracts showed activity on adjuvantinduced arthritis in rats, with the best effect being observed after 96 h (82.2±4.6 and 80.6±7.3%, respectively)
Investigating the melt pool properties and thermal effects of multi-laser diode area melting
Diode area melting (DAM) is a new additive manufacturing process that utilises customised architectural arrays of low-power
laser diode emitters for high-speed parallel processing of metallic feedstock. The laser diodes operate at shorter laser wavelengths
(808 nm) than conventional SLM fibre lasers (1064 nm) theoretically enabling more efficient energy absorption for specific
materials. This investigation presents the first work investigating the melt pool properties and thermal effects of the multi-laser
DAM process, modelling generated melt pools the unique thermal profiles created along a powder bed during processing. Using
this approach process, optimisation can be improved by analysing this thermal temperature distribution, targeting processing
conditions that induce full melting for variable powder layer thicknesses. In this work, the developed thermal model simulates the
DAM processing of 316L stainless steel and is validated with experimental trials. The simulation indicates that multi-laser DAM
methodology can reduce residual stress formation compared to the single point laser scanning methods used during selective laser
melting
Nursing intervention through peers for selfefficacy and alcohol consumption in adolescents
Introduction: Alcohol consumption is a problem closely related to adolescence. At first, it tends to be established as a habit and after that as an addiction, when the individual in question still is an adolescent. Objective: The study sought to determine the effect caused by nursing intervention through “interconnected” peers on self-efficacy and alcohol consumption. Results: Statistically significant difference was shown post-intervention (z = -4.86; p = .000) and at follow-ups at three months (z = -4.78; p = .000) and six months (z = -4.78; p = .000); this is also activate in alcohol consumption at the post-intervention measurement (z = -4.74; p = .000) and at follow-ups at three months (z = -4.74; p = .000) and six months (z = -4.74; p = .000). Conclusions: Based on the objective of the study, it is pos-sible to conclude that it is feasible to decrease alcohol consumption and favor self-efficacy in adolescents through “interconnected”.Introducción: El consumo de alcohol es un problema muy relacionado con la adolescencia en un principio tiende a establecer como un hábito y luego como una adicción, cuando el individuo es un adolescente. Objetivo: El estudio buscó determinar el efecto en la autoeficacia y consumo de alcohol de la intervención de enfermería a través de pa-res “interconectados”. Resultados: Se mostró diferencia estadísticamente significativa posterior a la intervención (z = -4.86; p = .000) y en los seguimientos de tres (z = -4.78; p = .000) y seis meses (z = -4.78; p = .000), esto también se activa en el consumo de alcohol en la medición posterior a la intervención (z = -4.74; p = .000) y en los seguimientos de tres (z = -4.74; p = .000) y seis meses (z = -4,74; p = .000). Conclusiones: En base al objetivo del estudio es posible concluir que es factible disminuir el consumo de alcohol y favorecer la autoeficacia en los adolescentes mediante “interconectados”
The Mo(ve)ment to Prioritize Antiracist Mathematics: Planning for This and Every School Year
Dear Colleague,
TODOS: Mathematics for ALL is proud of its almost two decades of advocacy for equity and excellence for all children in mathematics education, specifically Latina/o children. Over the years, TODOS has delivered webinars, podcasts, blogs, conferences, and resources for educators, families, and children to address and provide tools to eliminate the harmful practices too many children and families experience in school and in life. This position statement, The Mo(ve)ment to Prioritize Antiracist Mathematics: Planning for This and Every School Year, and supporting commentaries, including one commentary in Spanish - place the essential actions of the 2016 NCSM - TODOS joint social justice position statement, Mathematics Education Through the Lens of Social Justice: Acknowledgment, Actions, and Accountability, into new contexts as a response to our nation\u27s inequities and injustices made visible by COVID-19 and the tragic murders of George Floyd, Brianna Taylor, and other unarmed Black and Brown citizens. No longer could a focus on curriculum, assessment, and instruction alone be enough for children to survive in today\u27s world. It was time to step up, find strength, move beyond hurt, fear, and usual conversations to take leadership in the fight for antiracism..
Mujeres estudiantes de educación superior y los factores psicosociales en el marco del binomio pasividad-violencia
En el presente trabajo se muestran los resultados preliminares de una investigación que está explorando la cuestión de la violencia-pasividad en estudiantes de educación superior. Su objetivo es iniciar la construcción de indicadores sobre las características psicosociales en mujeres estudiantes que han sufrido violencia de género. El supuesto del que se parte es que hay ciertas características psico-sociales de pasividad-violencia en las estudiantes que viven o han vivido relaciones de violencia, colocándolas en lugares subjetivos emocionales que les impiden trabajar racionalmente sus relaciones interpersonales. Los resultados preliminares son de un cuestionario-escala que explora las conductas agresivas de relaciones de pareja en orden psicológico, aplicado a una muestra de 329 alumnos de educación superior en Tabasco, México. Enfatizado las acciones femeninas -en relación a las agresiones masculinas-, donde se presentan conductas simultáneas y/o opuestas que oscilan entre víctima, partícipe, resistencia, agresión, anulación
Evaluation of trypanocidal properties of ferrocenyl and cyrhetrenyl N-acylhydrazones with pendant 5-nitrofuryl group
Four N-acylhydrazones of general formulae [R1-C(O)-NH-N=C(R2)(5-nitrofuryl)] with (R1 = ferrocenyl or cyrhetrenyl and R2 = H or Me) are synthesized and characterized in solution and in the solid-state. Comparative studies of their stability in solution under different experimental conditions and their electrochemical properties are reported. NMR studies reveal that the four compounds are stable in DMSO‑d6 and complementary UV-Vis studies confirm that they also exhibit high stability in mixtures DMSO:H2O at 37 °C. Electrochemical studies show that the half-wave potential of the nitro group of the N-acylhydrazones is smaller than that of the standard drug nifurtimox and the reduction process follows a self-protonation mechanism. In vitro studies on the antiparasitic activities of the four complexes and the nifurtimox against Trypanosoma cruzi and Trypanosoma brucei reveal that: i) the N-acylhydrazones have a potent inhibitory growth activity against both parasites [EC50 in the low micromolar (in T. cruzi) or even in the nanomolar (in T. brucei) range] and ii) cyrhetrenyl derivatives are more effective than their ferrocenyl analogs. Parallel studies on the L6 rat skeletal myoblast cell line have also been conducted, and the selectivity indexes determined. Three of the four N-acylhydrazones showed higher selectivity towards T. brucei than the standard drug nifurtimox. Additional studies suggest that the organometallic compounds are bioactivated by type I nitroreductase enzymes.</p
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