1,413 research outputs found
In vitro biocontrol activity of Trichoderma harzianum on Alternaria alternata in the presence of growth regulators
http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582001000200006&lng=es&nrm=isoThe in vitro biocontrol ability of Trichoderma harzianum on the phytopathogen
Alternaria alternata improved in the presence of the growth regulators gibberellic
acid (GA3), or indolacetic acid (IAA) or benzylaminopurine (BAP) or foliar nutrient at
concentrations similar or higher than those used at the field level. These plant hormones
decreased the secretion of endopolygalacturonase (endo-PG) of A. alternata by approximately
20%, did not modify endochitinase (endo-CH) secretion of T. harzianum and did not alter
germination of conidia or mycelia growth of any of these fungi. The presence of T. harzianum
decreased endo-PGase secretion of A. alternata by about 50%. This inhibitory effect was
independent of the presence of growth regulators. The level of secreted endo-PG of T.
harzianum was not modified by the presence of A. alternata, but the presence of this
phytopathogen in cultures of T. harzianum, increased both the growth of the biocontroller and
its secretion of endo-CH
Periodismo en línea y desarrollo de blogs como alternativa de expresión informativa
El término “blog” proviene de las palabras Web y Log, y se ha convertido en unaherramienta de recuento de historias paralelas, ya que a través de ellos es posiblevisualizar distintas interpretaciones a un mismo acontecimiento.Si bien el origen de los blogs es personal, a últimas fechas los medios periodísticosen línea han colocado blogs como recurso de interacción entre sus lectores. Esto lesha arrojado retroalimentación, y ha permitido obtener una sensibilidad directa de laopinión pública en formación y promueve nuevos temas a insertarse en la agenda.El presente trabajo revisa los blogs como alternativas de información al recursoperiodístico, analizando el comportamiento de los blogs insertados en diversosperiódicos y sitios de información periodística en línea
MoMA Algorithm: A Bottom-Up Modeling Procedure for a Modular System under Environmental Conditions
The functioning of complex systems relies on subsystems (modules) that in turn are
composed of multiple units. In this paper, we focus on modular systems that might fail due to wear
on their units or environmental conditions (shocks). The lifetimes of the units follow a phase-type
distribution, while shocks follow a Markovian Arrival Process. The use of Matrix-Analytic methods
and a bottom-up approach for constructing the system generator is proposed. The use of modular
structures, as well as its implementation by the Modular Matrix-Analytic (MoMA) algorithm, make
our methodology flexible in adapting to physical changes in the system, e.g., incorporation of new
modules into the current model. After the model for the system is built, the modules are seen as a
‘black box’, i.e., only the contribution of the module as a whole to system performance is considered.
However, if required, our method is able to keep track of the events within the module, making
it possible to identify the state of individual units. Compact expressions for different reliability
measures are obtained with the proposed description, optimal maintenance strategies based on
critical operative states are suggested, and a numerical application based on a k-out-of-n structure
is developed.Spanish Ministry of Science and Innovation-State Research Agency PID2020-120217RB-I00
PID2021-123737NB-I00Junta de Andalucia B-FQM-284-UGR20
CEX2020-001105-/AEI/10.13039/50110001103
The continuous-time hidden Markovmodel based on discretization. Properties of estimators and applications
Universidad de Granada/CBU
Selection of bioantagonistic bacteria to be used in biological control of Rhizoctonia solani in tomato
http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602011000100002&lng=es&nrm=isoBacteria from the rhizoplane and surrounding soil of healthy and Rhizoctonia
solani diseased tomato plants, cropped in greenhouse of the V Region of Chile,
were collected. The best bacterial strains, based on their ability to control
development of three R. solani isolates (identified as belonging to the anastomosis
groups AG-2-1, AG-4), were identified as B. subtilis (one isolate) and B. lentimorbus (two
different isolates). All bacterial isolates resulted effective for the in vitro control of growth of all
R. solani isolates, where the control mechanisms used by the bacteria do not involve the
secretion of fungal cell wall hydrolytic enzymes. R. solani AG-2-1 was more sensitive than R.
solani AG-4. On the other hand, all bacteria grew well in conditions similar to those that can be
found at the field level (considering pH, salinity, Fe3+ and temperature) and showed a good
capacity of tomato root colonization. These results suggest that the B. subtilis and B.
lentimorbus isolates studied have an excellent potential to be used as biocontrol agents of R.
solani in tomato greenhouses at the field level
Statistical supervised learning with engineering data: a case study of low frequency noise measured on semiconductor devices
The authors thank the Laboratory of Nanoelectronics in the Research Centre for Information and Communications Technologies (CITIC-UGR) at the University of Granada (Spain) for providing the data for the study. This work was supported in part by the Spanish Ministry of Science and Innovation through grants number RTI2018-099723-B-I00, and PID2020-120217RB-I00; the Spanish Junta de Andalucia through grants number B-FQM-284-UGR20 and B-CTS-184-UGR20; and the IMAG-Maria de Maeztu grant CEX2020-001105-/AEI/10.13039/501100011033. The comments from two anonymous reviewers and the Associate Editor that have helped to improve the quality of the paper are also acknowledged.Our practical motivation is the analysis of potential correlations between spectral noise current and threshold voltage from
common on-wafer MOSFETs. The usual strategy leads to the use of standard techniques based on Normal linear regression
easily accessible in all statistical software (both free or commercial). However, these statistical methods are not appropriate
because the assumptions they lie on are not met. More sophisticated methods are required. A new strategy based on the most
novel nonparametric techniques which are data-driven and thus free from questionable parametric assumptions is proposed.
A backfitting algorithm accounting for random effects and nonparametric regression is designed and implemented. The
nature of the correlation between threshold voltage and noise is examined by conducting a statistical test, which is based on
a novel technique that summarizes in a color map all the relevant information of the data. The way the results are presented
in the plot makes it easy for a non-expert in data analysis to understand what is underlying. The good performance of the
method is proven through simulations and it is applied to a data case in a field where these modern statistical techniques are
novel and result very efficient.Spanish Government RTI2018-099723-B-I00
PID2020-120217RB-I00Junta de Andalucia B-FQM-284-UGR20
B-CTS-184-UGR20IMAG-Maria de Maeztu grant CEX2020-001105-/AE
Acompañamiento pedagógico que realiza la Directora para fortalecer el desempeño docentes de la Escuela Pública “Pablo Antonio Cuadra” del Municipio de Nindirí, Departamento de Masaya, durante el II semestre del año lectivo 2016
La Escuela Pública Pablo Antonio Cuadra se encuentra ubicada en la comunidad
de San Francisco del municipio de Nindirí, departamento de Masaya.
El estudio de investigación se basa en el “Acompañamiento Pedagógico que
realiza la Directora a los docentes”, esta se realizó de forma objetiva y científica
con el fin de obtener los resultados que permitiera valorar el proceso que realiza
para desarrollar el acompañamiento de los docentes en el aula de clase y de esta
forma brindar posibles alternativas de mejoras ante el problema presentado
Este tema es de vital importancia debido a la trascendencia que tiene el
Acompañamiento Pedagógico en el proceso de enseñanza - aprendizaje en la
actualidad para los docentes y estudiantes del turno Matutino de este centro
educativo
Presenta un enfoque cuantitativo, de tipo descriptivo y de corte transversal. Las
variables principales del tema son: Acompañamiento Pedagógico y el Desempeño
Docente.
Para el estudio se seleccionó una muestra de 49 personas, entre ellas se
mencionan a la directora, 7 docentes y una muestra de 41 estudiantes de sexto
grado. Los instrumentos aplicados fueron guía de entrevista, guía de encuesta y
guía de observación documental.
Este permitió obtener los siguientes resultados, la directora realiza
acompañamiento pedagógico de manera mensual a los docentes, beneficiando de
esta manera el desempeño de los docentes, ya que toman las sugerencias que se
le brinda permiten mejorar los procesos académicos. Se sugiere a la directora que
continúe realizando los acompañamientos de manera periódica tomando en
cuenta todas las disciplinas que se desarrollan en las aulas de clas
The continuous-time hidden Markov model based on discretization. Properties of estimators and applications
This work was jointly supported by the Spanish Ministry of Science and Innovation-State Research Agency through grants numbered PID2020-120217RB-I00 and PID2021-123737NB-I00, and the IMAG-Maria de Maeztu grant CEX2020-001105-/AEI/10.13039/501100011033; and by the Spanish Junta de Andalucia through grant number B-FQM-284-UGR20.In this paper we consider continuous-time hidden Markov processes (CTHMM). The model considered is a two-dimensional stochastic process (Xt, Yt) , with Xt an unobserved (hidden) Markov chain defined by its generating matrix and Yt an observed process whose distribution law depends on Xt and is called the emission function. In general, we allow the process Yt to take values in a subset of the q-dimensional real space, for some q. The coupled process (Xt, Yt) is a continuous-time Markov chain whose generator is constructed from the generating matrix of X and the emission distribution. We study the theoretical properties of this two-dimensional process using a formulation based on semi-Markov processes. Observations of the CTHMM are obtained by discretization considering two different scenarii. In the first case we consider that observations of the process Y are registered regularly in time, while in the second one, observations arrive at random. Maximum-likelihood estimators of the characteristics of the coupled process are obtained in both scenarii and the asymptotic properties of these estimators are shown, such as consistency and normality. To illustrate the model a real-data example and a simulation study are considered.Universidad de Granada/CBUAIMAG-Maria de Maeztu
CEX2020-001105-/AEI/10.13039/501100011033Spanish Junta de Andalucia
B-FQM-284-UGR20Spanish Ministry of Science and Innovation-State Research Agency
PID2020-120217RB-I00, PID2021-123737NB-I0
Optimization and Validation of HS-GC/MS Method for the Controlled Release Study of Microencapsulated Specific Bioattractants for Target-Plaguicide Production
Insect plagues are a problem often hard to solve due to the harmful effects caused by the pesticides used to combat them. Consequently, the pesticide market is increasingly trying to develop new technologies to prevent the unwanted effects that common plague treatments usually bring with them. In this work, four specific bioattractants of Musca domestica, extracted from fungi (β-ocimene, phenol, p-cresol, and indole) were microencapsulated with β-cyclodextrin in order to produce an economically and environmentally sustainable bait containing biocides in the near future. Cyclodextrins will retain these volatile compounds until their use by the consumer when the product comes into contact with water. Then, the bioattractants will be released in the medium in a controlled manner. An analytical methodology based on headspace extraction coupled to gas chromatography and mass spectrometry (HS-GC/MS) has been developed and validated following Environmental Protection Agency (EPA) and European Commission Directorate General for Health and Food Safety guidelines for the bioattractants controlled release study from the microencapsulated product. The analytical method has been shown to be accurate and precise and has the sensitivity required for controlled release studies of the four bioattractants analyzed. The release of the bioattractants from microencapsulated products achieved the “plateau” after 3 h in all cases.This research was funded by University of the Basque Country (UPV/EHU) (project GIU19/068)
Multiplicative local linear hazard estimation and best one-sided
This paper develops detailed mathematical statistical theory of a new class of cross-validation techniques of local linear kernel hazards and their multiplicative bias corrections. The new class of cross-validation combines principles of local information
and recent advances in indirect cross-validation. A few applications of cross-validating multiplicative kernel hazard estimation do exist in the literature. However, detailed mathematical statistical theory and small sample performance are introduced via
this paper and further upgraded to our new class of best one-sided cross-validation. Best one-sided cross-validation turns out to have excellent performance in its practical illustrations, in its small sample performance and in its mathematical statistical
theoretical performance
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