12 research outputs found
Motivación y desempeño laboral de los docentes de una universidad de la provincia de Jaén, 2022
El presente trabajo de investigación presenta como objetivo principal
determinar la relación entre la motivación y el desempeño laboral de los docentes
de una universidad de la provincia de Jaén, 2022. El estudio fue de tipo aplicado
cuantitativo, con diseño no experimental y de nivel correlacional; con una muestra
de 34 docentes de ingeniería civil de una universidad de la provincia de Jaén, como
instrumentos se utilizaron dos cuestionarios uno para medir la motivación y otro
para medir el desempeño laboral. Los resultados fueron obtenidos mediante
estadística descriptiva e inferencial, usando el software Excel 2020 y el paquete
estadístico SPSS v. 26, donde se obtuvo que el 44.1 % tienen motivación regular y
el 70.6 % tiene desempeño laboral regular, se concluyó que la motivación tiene alta
correlación con el desempeño laboral de los docentes de una universidad de la
provincia de Jaén (Spearman = 0.808); esto quiere decir que a medida que la
motivación se vea afectada el desempeño laboral de los docentes también se
afectará
A quick and effective estimation of algal density by turbidimetry developed with Chlorella vulgaris cultures
El uso de Chlorella vulgaris Beijerinck como alimento para el zooplancton implica la necesidad de optimizar el cultivo de algas para mantener su crecimiento en el tiempo. En este trabajo se desarrolló un método que relaciona la densidad del cultivo con la turbidez para estimar la biomasa algal. Esta técnica se ha mejorado mediante la aplicación del análisis digital para el recuento de las algas que promueve la exactitud y reduce el disturbio en el cultivo, con obtención rápida y fácil de resultados repetibles. Se realizaron dos cultivos de C. vulgaris en recipientes de 3 L con aireación e iluminación continua (50 µmol fotones m–2 ·s–1 a 660 nm), alcanzando 214 y 280 NTU, respectivamente. El recuento de las muestras se realizó por medio de imágenes digitales tomadas con un microscopio invertido. Se aplicaron dos técnicas para el recuento de las alícuotas: la sedimentación directa y la sedimentación con homogeneización previa. Con el fin de comparar el ajuste de ambos métodos de sedimentación, las fotografías fueron tomadas en los sectores central, medio y periférico de la cámara de sedimentación. Para ambas técnicas se contaron un mínimo de 17 individuos imagen–1 y un máximo de 404 individuos imagen–1, con un tiempo promedio de un minuto por imagen. A niveles bajos de turbidez (< 40 NTU) la dispersión de los datos fue similar entre ambas técnicas (rango error: 16-60 %). Para niveles superiores de turbidez, en la técnica de sedimentación directa se observó un mayor rango de error (31-50 %) mientras que en la técnica con homogenización previa osciló entre 5 y 13 %. El análisis de regresión evidenció un bajo ajuste de los datos (67 %), que en la sedimentación sin homogeneización responde a un patrón reiterado de aumento de densidad algal desde la periferia hacia el centro de la cámara de sedimentación. La inclusión de una homogeneización previa promueve un mejor ajuste del modelo (99 %) y determina un incremento en la consistencia del método. Con los resultados obtenidos se demuestra que la técnica turbidimétrica desarrollada puede ser utilizada con éxito en cultivos de especies de algas cuyas formas geométricas sean reconocidas por el procesador de imágenes.The use of Chlorella vulgaris Beijerinck as a food source for zooplankton requires the optimization of algal-culture conditions for prolonged growth maintenance. In this study, we developed a method that relates algal density to culture turbidity to estimate culture biomass. This method was improved by applying digital analysis for algal counting, which promotes accuracy, low culture disturbance, easy repetition and the rapid acquisition of results. Two 3-L cultures of C. vulgaris, maintained for two weeks with continuous lighting (eight light-emitting diodes at 50 µmol photons m–2 ·s–1, at 660 nm) and aerators to prevent algal sedimentation, reached turbidities of 214 and 280 NTUs, respectively. Sample counting was performed using digital images obtained with an inverted microscope. Aliquot sedimentation was compared with or without previous homogenization through photographs taken in the central, middle, and peripheral sectors of the Utermöhl settling chambers. For each procedure, we counted between 17 and 404 individuals image–1, requiring, on average, one minute image–1. At low turbidity (< 40 NTU), the data dispersion was similar between the two protocols (error range, 16 to 60 %); at higher turbidity, the direct sedimentation alone gave a larger error (31-50 %) than with prior homogenization (5-13 %). Regression analysis at low data fit (67 %) suggested that the sedimentation heterogeneity of non-homogenized samples corresponded to a pattern of settled algae having increasing density from the periphery to the centre of the chamber, but with homogenization, a better model fitting (99 %) resulted, contributing to greater consistency with that procedure. We consider that this turbidometric protocol could be used successfully with cultures of algae that have geometrical shapes recognizable by the image software.Fil: Ferrando, Noelia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Benitez, Hernan Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Gabellone, Nestor Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Claps, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Altamirano, Pablo Rodrigo. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; Argentin
High-charge 10 GeV electron acceleration in a 10 cm nanoparticle-assisted hybrid wakefield accelerator
In an electron wakefield accelerator, an intense laser pulse or charged
particle beam excites plasma waves. Under proper conditions, electrons from the
background plasma are trapped in the plasma wave and accelerated to
ultra-relativistic velocities. We present recent results from a
proof-of-principle wakefield acceleration experiment that reveal a unique
synergy between a laser-driven and particle-driven accelerator: a high-charge
laser-wakefield accelerated electron bunch can drive its own wakefield while
simultaneously drawing energy from the laser pulse via direct laser
acceleration. This process continues to accelerate electrons beyond the usual
decelerating phase of the wakefield, thus reaching much higher energies. We
find that the 10-centimeter-long nanoparticle-assisted wakefield accelerator
can generate 340 pC, 10.4+-0.6 GeV electron bunches with 3.4 GeV RMS convolved
energy spread and 0.9 mrad RMS divergence. It can also produce bunches with
lower energy, a few percent energy spread, and a higher charge. This
synergistic mechanism and the simplicity of the experimental setup represent a
step closer to compact tabletop particle accelerators suitable for applications
requiring high charge at high energies, such as free electron lasers or
radiation sources producing muon beams
El cultivo de trigo en la Sierra Sur del Perú
En la publicación se describe las características fenológicas del trigo, las variedades comerciales en la sierra sur del Perú y el manejo integrado del cultivo de trigo. Plagas y su control
Derecho, enfoques y métodos. Una retrospectiva
El libro se edita en atención al Primer Programa Avanzado en Metodología e Investigación Jurídica. Iniciativa apoyada por la PUCE (Quito e Ibarra) y organizada por la PUCE-A. A través de este texto, se recopilan los aportes de expertos en Metodología del Derecho. A partir de perspectivas multidisciplinares, se introduce una contribución para la comprensión epistemológica y fenomenológica de la ciencia jurídica. En el texto se introducen aportes desde las distintas ramas del derecho, destacando los derechos humanos, el derecho civil, el derecho administrativo y las modernas expresiones conocidas como Law &. En este sentido, sobresalen los estudios introducidos a partir del Análisis Económico del Derecho, los Estudios Institucionales Comparados y el Derecho & Religión
The successful implementation of a trauma and acute care surgery model in Ecuador
Durante años, las emergencias quirúrgicas en Ecuador se manejaron caso por caso sin una estandarización significativa. Para abordar estos problemas, el Hospital Regional Vicente Corral Moscoso adaptó e implementó un modelo de “cirugía de trauma y atención aguda” (TACS) a la realidad de Cuenca, Ecuador.
Se realizó un estudio de cohorte, comparando pacientes expuestos al modelo tradicional y pacientes expuestos al modelo TACS. Las variables evaluadas incluyeron el número de pacientes quirúrgicos atendidos en el departamento de emergencias, el número de intervenciones quirúrgicas, el número de cirugías realizadas por cirujano, el tiempo de espera quirúrgico, la duración de la estadía y la mortalidad hospitalaria.For years, surgical emergencies in Ecuador were managed on a case-by-case basis without significant standardization. To address these issues, the Regional Hospital Vicente Corral Moscoso adapted and implemented a model of “trauma and acute care surgery” (TACS) to the reality of Cuenca, Ecuador.
A cohort study was carried out, comparing patients exposed to the traditional model and patients exposed to the TACS model. Variables assessed included number of surgical patients attended to in the emergency department, number of surgical interventions, number of surgeries performed per surgeon, surgical wait time, length of stay and in-hospital mortality
Multi-environment multi-QTL association mapping identifies disease resistance QTL in barley germplasm from Latin America
Diseases represent a major constraint for barley (Hordeum vulgare L.) production in Latin America. Spot blotch (caused by Cochliobolus sativus), stripe rust (caused by Puccinia striiformis f.sp. hordei) and leaf rust (caused by Puccinia hordei) are three of the most important diseases that affect the crop in the region. Since fungicide application is not an economically or environmentally sound solution, the development of durably resistant varieties is a priority for breeding programs. Therefore, new resistance sources are needed. The objective of this work was to detect genomic regions associated with field level plant resistance to spot blotch, stripe rust, and leaf rust in Latin American germplasm. Disease severities measured in multi-environment trials across the Americas and 1,096 SNPs in a population of 360 genotypes were used to identify genomic regions associated with disease resistance. Optimized experimental design and spatial modeling were used in each trial to estimate genotypic means. Genome-Wide Association Mapping (GWAS) in each environment was used to detect Quantitative Trait Loci (QTL). All significant environment-specific QTL were subsequently included in a multi-environment-multi-QTL (MEMQ) model. Geographical origin and inflorescence type were the main determinants of population structure. Spot blotch severity was low to intermediate while leaf and stripe rust severity was high in all environments. Mega-environments were defined by locations for spot blotch and leaf rust. Significant marker-trait associations for spot blotch (9 QTL), leaf (6 QTL) and stripe rust (7 QTL) and both global and environment-specific QTL were detected that will be useful for future breeding efforts
Program for the epidemiological evaluation of stroke in Tandil, Argentina (PREVISTA) study: rationale and design
The availability of population-based epidemiological data on the incident risk of stroke is very scarce in Argentina and other Latin American countries. in response to the priorities established by the World Health Organization and the United Nations, PREVISTA was envisaged as a population-based program to determine the risk of first-ever and recurrent stroke and transient ischemic attack incidence and mortality in Tandil, Buenos Aires, Argentina.The study will be conducted according to Standardized Tools for Stroke Surveillance (STEPS Stroke) methodology and will enroll all new (incident) and recurrent consecutive cases of stroke and transient ischemic attack in the City of Tandil between May 1st, 2013 and April 30, 2015. the study will include patients with ischemic stroke, non-traumatic primary intracerebral hemorrhage, subarachnoid hemorrhage, and transient ischemic attack. To ensure the inclusion of every cerebrovascular event during an observation period of two years, we will instrument an 'intensive screening program', consisting of a comprehensive daily tracking of every potential event of stroke or transient ischemic attack using multiple overlapping sources. Mortality would be determined during follow-up for every enrolled patient. Also, fatal community events would be screened daily through revision of death certificates at funeral homes and local offices of vital statistics. All causes of death will be adjudicated by an ad-hoc committee.The close population of Tandil is representative of a large proportion of Latin-American countries with low- and middle-income economies. the findings and conclusions of PREVISTA may provide data that could support future health policy decision-making in the region.Heart and stroke Foundation of CanadaINECO Fdn, Vasc Res Inst, Buenos Aires, DF, ArgentinaUniv Western Ontario, London Hlth Sci Ctr, Dept Clin Neurol Sci, London, ON N6A 5A5, CanadaHosp Ramon Santamarina, Tandil, Buenos Aires, ArgentinaNueva Clin Chacabuco, Tandil, Buenos Aires, ArgentinaSanatorio Tandil, Tandil, Buenos Aires, ArgentinaAUT Univ, Sch Rehabil & Occupat Studies, Natl Inst Stroke & Appl Neurosci, Auckland, Northcote, New ZealandUniversidade Federal de São Paulo, Paulista Sch Med, São Paulo, BrazilDuke Clin Res Inst, Durham, NC USABCRI, São Paulo, BrazilMayo Clin, Neurosci Intens Care Unit, Rochester, MN USAUniv Toronto, St Michaels Hosp, Li Ka Shing Knowledge Inst, Stroke Outcomes Res Ctr,Dept Med, Toronto, ON, CanadaUniv Toronto, St Michaels Hosp, Li Ka Shing Knowledge Inst, Stroke Outcomes Res Ctr,Dept Hlth Policy Manageme, Toronto, ON, CanadaUniv Toronto, St Michaels Hosp, ICES, Toronto, ON, CanadaCopenhagen Univ Hosp, Dept Neurol, Herlev, DenmarkCirculo Med Tandil, Buenos Aires, DF, ArgentinaResonancia Ctr, Tandil, ArgentinaUniversidade Federal de São Paulo, Paulista Sch Med, São Paulo, BrazilWeb of Scienc
The acceleration of a high-charge electron bunch to 10 GeV in a 10-cm nanoparticle-assisted wakefield accelerator
An intense laser pulse focused onto a plasma can excite nonlinear plasma waves. Under appropriate conditions, electrons from the background plasma are trapped in the plasma wave and accelerated to ultra-relativistic velocities. This scheme is called a laser wakefield accelerator. In this work, we present results from a laser wakefield acceleration experiment using a petawatt-class laser to excite the wakefields as well as nanoparticles to assist the injection of electrons into the accelerating phase of the wakefields. We find that a 10-cm-long, nanoparticle-assisted laser wakefield accelerator can generate 340 pC, 10 ± 1.86 GeV electron bunches with a 3.4 GeV rms convolved energy spread and a 0.9 mrad rms divergence. It can also produce bunches with lower energies in the 4–6 GeV range
The acceleration of a high-charge electron bunch to 10 GeV in a 10-cm nanoparticle-assisted wakefield accelerator
An intense laser pulse focused onto a plasma can excite nonlinear plasma waves. Under appropriate conditions, electrons from the background plasma are trapped in the plasma wave and accelerated to ultra-relativistic velocities. This scheme is called a laser wakefield accelerator. In this work, we present results from a laser wakefield acceleration experiment using a petawatt-class laser to excite the wakefields as well as nanoparticles to assist the injection of electrons into the accelerating phase of the wakefields. We find that a 10-cm-long, nanoparticle-assisted laser wakefield accelerator can generate 340 pC, 10 ± 1.86 GeV electron bunches with a 3.4 GeV rms convolved energy spread and a 0.9 mrad rms divergence. It can also produce bunches with lower energies in the 4–6 GeV range