398 research outputs found
Limitaciones y potencialidades del sistema de producción de tomate de árbol en el departamento de Caldas.
Se describen y analizan las características sobresalientes del sisema de producción tomate de árbol, Cyphomandra betacea en el departamento de Caldas, con el objeto de entender su nacionalidad y definir alternativas tecnológicas aptas para los agricultores de la región. La toma de información se hizo a través de una encuesta formal difiniendo los límites del sistema a través de unidades espaciales denominadas de referencia. Se analizan los cítricos de competitividad productiva, desarrollo sostenible, equidad y desarrollo tecnológicoTomate-Solanum lycopersicu
Real world data in primary care: validation of diagnosis of atrial fibrillation in primary care electronic medical records and estimated prevalence among consulting patients
Primary care electronic medical records contain clinical-administrative information on a high percentage of the population. Before this information can be used for epidemiological purposes, its quality must be verified. This study aims to validate diagnoses of atrial fibrillation (AF) recorded in primary care electronic medical records and to estimate the prevalence of AF in the population attending primary care consultations. Methods: We performed a cross-sectional validation study of all diagnoses of AF recorded in primary care electronic medical records in Madrid (Spain). We also performed simple random sampling of diagnoses of AF (ICPC-2 code K78) registered by 55 physicians and random age- and sex-matched sampling of the records that included a diagnosis of AF. Electrocardiograms, echocardiograms, and hospital discharge or cardiology clinic reports were matched. Sensitivity, specificity, positive and negative predictive values (PPV and NPV), and overall agreement were calculated using the kappa statistic (κ). The prevalence of AF in the community of Madrid was estimated considering the sensitivity and specificity obtained in the validation. All calculations were performed overall and by sex and age groups. Results: The degree of agreement was very high (κ = 0.952), with a sensitivity of 97.84%, specificity of 97.39%, PPV of 97.37%, and NPV of 97.85%. The prevalence of AF in the population aged over 18 years was 2.41% (95%CI 2.39–2.42% [2.25% in women and 2.58% in men]). This increased progressively with age, reaching 16.95% in those over 80 years of age (15.5% in women and 19.44% in men). Conclusions: The validation results obtained enable diagnosis of AF recorded in primary care to be used as a tool for epidemiological studies. A high prevalence of AF was found, especially in older patientsThis study forms part of research funded by the FIS (Fondo de Investigaciones Sanitarias—Health Research Fund, Instituto de Salud Carlos III) grants no. PI13/00632, and co-funded by the European Union through the Fondo Europeo de Desarrollo Regional (FEDER, “A way of shaping Europe”. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Análisis Campo-Sustancia de TRIZ para el uso de Trichoderma asperelloides como antagónico en Citrus sinensis
La teoría de solución de problemas de inventiva (TRIZ), es el resultado del análisis minucioso de patentes a nivel mundial, forma parte de un sistema de principios y algoritmos donde se amplifica la posibilidad de encontrar soluciones innovadoras a problemas científicos, superando la inercia psicológica basada en paradigmas. El presente trabajo propone un análisis biológico utilizando la herramienta analítica TRIZ con el uso del Análisis Campo-Sustancia (Su-Field) originalmente destinado a resolver problemas de ingeniería para determinar el efecto antagónico de Trichoderma asperelloides frente a Fusarium, patógeno presentado en plantas de cítricos encontrando como el resultado final ideal el uso de T. asperelloides como agente de control patógeno en plantas de cítricos (Citrus sinensis) en el norte de Veracruz, México
BIOPROSPECCIÓN DE LA ACTIVIDAD ANTIMICÓTICA DE EXTRACTOS METANÓLICOS DE ARIOCARPUS KOTSCHOUBEYANUS Y ARIOCARPUS RETUSUS
The antifungal activity of methanolic extracts from Ariocarpus kotschoubeyanusand A. retusus, two native xerophytes ofnortheastern Mexico, was determined onthe fungal dermatophytes Trichophytontonsurans, Microsporum canis and Microsporum cookei. Putative active metabolites were identified by phytochemicalscreening using evidence for functionalgroups; determination of antifungal activity was conducted by the disk-diffusion platemethod as part of the process of understanding the chemistry and efficacy of theseplant products. Doses tested were 125,250 y 500 mg/mL. Extracts were positivefor carbonyl groups, phenolic oxhidrils,sterols and methyl sterols, coumarins, sesquiterpenlactones, saponins, flavonoids andalkaloids. Extract from A. retusus (stem)yielded the greatest activity against Trichophyton tonsurans and Microsporum cookei.Univariate analysis of variance revealedthat with regard to antifungal activity therewere significant differences between fungi,culture media and analyzed doses withrespect to positive control of ketoconazole.These results served to validate empiricalknowledge about these plants in traditionalmedicine. These studies form a basis forfurther research in the search for bioactivecompounds and the discovery of potentialherbal medicaments.Se determinó la actividad antifúngica invitro de extractos metanólicos de Ariocarpus kotschoubeyanus y Ariocarpusretusus, plantas xerófitas del noreste delpaís, usadas en la medicina tradicional,sobre los hongos dermatofitos Trichophytontonsurans, Microsporum canis y Microsporum cookei. Los metabolitos presentes seidentificaron por tamizaje fitoquímico empleando pruebas para grupos funcionales, ladeterminación de actividad antifúngica serealizó por el método de difusión en placaempleando microdiscos, con la finalidadde entender la química y eficacia de estosproductos vegetales, las dosis evaluadasde estos extractos fueron 125, 250 y 500mg/mL. Los extractos resultaron positivospara grupos carbonilo, oxidrilos fenólicos,esteroles y metilesteroles, cumarinas, sesquiterpenlactonas, saponinas, flavonoides yalcaloides. El extracto que presentó mayoractividad fue el de Ariocarpus retusus(tallo) contra Trichophyton tonsurans y Microsporum cookei. El análisis estadístico devarianza univariante reveló que en cuantoa la actividad antifúngica, existe diferencia significativa entre hongos, medios de cultivo y dosis evaluadas de los extractos conrespecto al control positivo de ketoconazol.Estos resultados sirvieron para validar elconocimiento empírico que se tiene acercade estas plantas en la medicina tradicional.Siendo estos estudios una base para nuevas investigaciones sobre la búsqueda decompuestos bioactivos y el descubrimientode medicamentos potenciales de productosherbales
SISTEMA DE EXTRACCION DE LOS COEFICIENTES MAS OPTIMOS PARA UN MODELO NO LINEAL DE UN RF-PA (EXTRACTION SYSTEM OF THE MOST OPTIMAL COEFFICIENTS FOR A RF-PA NON-LINEAR MODEL)
ResumenEn este trabajo se desarrolla un sistema para el modelado de comportamiento de amplificadores de potencia a partir de la extracción de coeficientes basado en los kernels pares, impares y todos de un modelo polinomial con memoria, el sistema toma en cuenta los órdenes de no linealidad y nivel de memoria de corto término del dispositivo. Se implementó en una tarjeta FPGA Cyclone V para un proceso de modelado no lineal basado en banda simple previo a un proceso de predistorsión digital. Además, se desarrolló una interfaz gráfica de usuario que automatiza el proceso de extracción de coeficientes y modelado a partir de los kernels óptimos del modelo polinomial con memoria en base a la métrica NMSE como criterio para determinar la precisión del modelo que se desea calcular a partir de juego de datos de entrada-salida de un amplificador de potencia. Lo anterior se realiza una como alternativa viable de modelado para una etapa posterior de predistorsión digital como medio de reducir el efecto no deseado de recrecimiento espectral e invasión de bandas adyacentes. En este caso se presenta la opción óptima de modelado para un RF-PA de 10 W, donde la mejor precisión obtenida es de -53.48 dB NMSE superando sistemas de modelado reportados en el estado del arte.Palabras Claves: FPGA, Kernels, modelo polinomial con memoria, modelado no lineal, RF-PA. AbstractIn this work a system is developed for the behavior modeling of power amplifiers from the extraction of coefficients based on the odd, even and all kernels of a polynomial model with memory, the system takes into account the orders of non-linearity and short term memory level of the device. It was implemented on a Cyclone V FPGA card for a non-linear modeling process based on single band prior to a digital predistortion process. In addition, a graphical user interface was developed that automate the process of extraction of coefficients and modeling from the optimal kernels of the polynomial model with memory based on the NMSE metric as a criterion to determine the precision of the model to be calculated at starting from input-output data set of a power amplifier. The above is done as a viable modeling alternative for a further stage of digital predistortion as a means of reducing the unwanted effect of spectral regrowth and invasion of adjacent bands. In this case, the optimal modeling option for a 10 W RF-PA is presented, where the best precision obtained for the model found is -53.48 dB NMSE exceeding modeling systems reported in the state of the art.Keywords: FPGA, Kernels, Memory Polinomial Model, non-linear modelling, RF-PA
Orion-KL Observations with the Extended Tuning Range of the New SEPIA660 APEX Facility Instrument
During Science Verification of the new SEPIA660 facility receiver at APEX, we carried out a shallow line survey of the archetypal Kleinmann- Low Nebula in the Orion star forming region (Orion-KL). These observations cover the tuning range towards the band edges, which has recently been extended beyond ALMA Band 9 specifications. At these frequencies, atmospheric transmission is very low but still sufficient to detect bright lines in Orion-KL. We present the collected spectra and compare with surveys from the literature, demonstrating the capabilities of the instrument
Azimuthal asymmetry in the risetime of the surface detector signals of the Pierre Auger Observatory
The azimuthal asymmetry in the risetime of signals in Auger surface detector
stations is a source of information on shower development. The azimuthal
asymmetry is due to a combination of the longitudinal evolution of the shower
and geometrical effects related to the angles of incidence of the particles
into the detectors. The magnitude of the effect depends upon the zenith angle
and state of development of the shower and thus provides a novel observable,
, sensitive to the mass composition of cosmic rays
above eV. By comparing measurements with predictions from
shower simulations, we find for both of our adopted models of hadronic physics
(QGSJETII-04 and EPOS-LHC) an indication that the mean cosmic-ray mass
increases slowly with energy, as has been inferred from other studies. However,
the mass estimates are dependent on the shower model and on the range of
distance from the shower core selected. Thus the method has uncovered further
deficiencies in our understanding of shower modelling that must be resolved
before the mass composition can be inferred from .Comment: Replaced with published version. Added journal reference and DO
Ultrahigh-energy neutrino follow-up of Gravitational Wave events GW150914 and GW151226 with the Pierre Auger Observatory
On September 14, 2015 the Advanced LIGO detectors observed their first
gravitational-wave (GW) transient GW150914. This was followed by a second GW
event observed on December 26, 2015. Both events were inferred to have arisen
from the merger of black holes in binary systems. Such a system may emit
neutrinos if there are magnetic fields and disk debris remaining from the
formation of the two black holes. With the surface detector array of the Pierre
Auger Observatory we can search for neutrinos with energy above 100 PeV from
point-like sources across the sky with equatorial declination from about -65
deg. to +60 deg., and in particular from a fraction of the 90% confidence-level
(CL) inferred positions in the sky of GW150914 and GW151226. A targeted search
for highly-inclined extensive air showers, produced either by interactions of
downward-going neutrinos of all flavors in the atmosphere or by the decays of
tau leptons originating from tau-neutrino interactions in the Earth's crust
(Earth-skimming neutrinos), yielded no candidates in the Auger data collected
within s around or 1 day after the coordinated universal time (UTC)
of GW150914 and GW151226, as well as in the same search periods relative to the
UTC time of the GW candidate event LVT151012. From the non-observation we
constrain the amount of energy radiated in ultrahigh-energy neutrinos from such
remarkable events.Comment: Published version. Added journal reference and DOI. Added Report
Numbe
Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory
We report a multi-resolution search for anisotropies in the arrival
directions of cosmic rays detected at the Pierre Auger Observatory with local
zenith angles up to and energies in excess of 4 EeV ( eV). This search is conducted by measuring the angular power spectrum
and performing a needlet wavelet analysis in two independent energy ranges.
Both analyses are complementary since the angular power spectrum achieves a
better performance in identifying large-scale patterns while the needlet
wavelet analysis, considering the parameters used in this work, presents a
higher efficiency in detecting smaller-scale anisotropies, potentially
providing directional information on any observed anisotropies. No deviation
from isotropy is observed on any angular scale in the energy range between 4
and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no
other deviation from isotropy is observed for moments beyond the dipole one.
The corresponding -values obtained after accounting for searches blindly
performed at several angular scales, are in the case of
the angular power spectrum, and in the case of the needlet
analysis. While these results are consistent with previous reports making use
of the same data set, they provide extensions of the previous works through the
thorough scans of the angular scales.Comment: Published version. Added journal reference and DOI. Added Report
Numbe
Calibration of the Logarithmic-Periodic Dipole Antenna (LPDA) Radio Stations at the Pierre Auger Observatory using an Octocopter
An in-situ calibration of a logarithmic periodic dipole antenna with a
frequency coverage of 30 MHz to 80 MHz is performed. Such antennas are part of
a radio station system used for detection of cosmic ray induced air showers at
the Engineering Radio Array of the Pierre Auger Observatory, the so-called
Auger Engineering Radio Array (AERA). The directional and frequency
characteristics of the broadband antenna are investigated using a remotely
piloted aircraft (RPA) carrying a small transmitting antenna. The antenna
sensitivity is described by the vector effective length relating the measured
voltage with the electric-field components perpendicular to the incoming signal
direction. The horizontal and meridional components are determined with an
overall uncertainty of 7.4^{+0.9}_{-0.3} % and 10.3^{+2.8}_{-1.7} %
respectively. The measurement is used to correct a simulated response of the
frequency and directional response of the antenna. In addition, the influence
of the ground conductivity and permittivity on the antenna response is
simulated. Both have a negligible influence given the ground conditions
measured at the detector site. The overall uncertainties of the vector
effective length components result in an uncertainty of 8.8^{+2.1}_{-1.3} % in
the square root of the energy fluence for incoming signal directions with
zenith angles smaller than 60{\deg}.Comment: Published version. Updated online abstract only. Manuscript is
unchanged with respect to v2. 39 pages, 15 figures, 2 table
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