Historical seismograms for unravelling a mysterious earthquake: The 1907 Sumatra Earthquake

History of instrumental seismology is short. Seismograms are available only for a little more than 100 years; high-quality seismograms are available only for the last 50 years and the seismological database is very limited in time. To extend the database, seismograms of old events are of vital importance. Many unusual earthquakes are known to have occurred, but their seismological characteristics are poorly known. The 1907 Sumatra earthquake is one of them (1907 January 4, M= 7.6). Gutenberg and Richter located this event in the outer-rise area of the Sunda arc. This earthquake is known to be anomalous because of its extensive tsunami, which is disproportionate of its magnitude. The tsunami affected the coastal areas over 950 km along the Sumatran coast. We investigated this earthquake using the historical seismograms we could collect from several seismological observatories. We examined the P-wave arrival times listed in the Strassburg Bulletin (1912) and other station bulletins. The scatter of the Observed−Computed traveltime residuals ranges from –30 to 30 s, too large to locate the event accurately. The uncertainty of the epicentre estimated from an S-P grid-search relocation study is at least 1° (~110 km). We interpreted the Omori seismograms from Osaka, Mizusawa and Tokyo, and the Wiechert seismograms from Göttingen and Uppsala by comparing them with the seismograms simulated from modern broad-band seismograms of the 2002, 2008 and two 2010 Sumatra earthquakes which occurred near the 1907 earthquake. From the amplitude of Rayleigh waves recorded on the Omori seismograms we conclude that the magnitude of the 1907 earthquake at about 30 to 40 s is about 7.8 (i.e. 7.5 to 8.0). The SH waveforms recorded on the Göttingen and Uppsala seismograms suggest that the 1907 earthquake is a thrust earthquake at a shallow depth around 30 km. The most likely scenario is that the 1907 earthquake initiated on the subduction interface, and slowly ruptured up-dip into the shallow sediments and caused the extensive tsunami. Although their quantity and quality are limited, historical seismograms provide key quantitative information about old events that cannot be obtained otherwise. This underscores the importance of preserving historical seismograms

First report of Diaphorina citri (Hemiptera: Psyllidae) in Costa Rica

In November 2003, the Asian citrus psyllid (Diaphorina citri) was found for the first time in Costa Rica, in Alajuela, Heredia and San Jose provinces. Figure 1 shows an adult female and nymphal instars of Asiatic citrus psyllid

a priori synthetic sampling for increasing classification sensitivity in imbalanced data sets

Building accurate classifiers for predicting group membership is made difficult when data is skewed or imbalanced which is typical of real world data sets. The classifier has the tendency to be biased towards the over represented group as a result. This imbalance is considered a class imbalance problem which will induce bias into the classifier particularly when the imbalance is high. Class imbalance data usually suffers from data intrinsic properties beyond that of imbalance alone. The problem is intensified with larger levels of imbalance most commonly found in observational studies. Extreme cases of class imbalance are commonly found in many domains including fraud detection, mammography of cancer and post term births. These rare events are usually the most costly or have the highest level of risk associated with them and are therefore of most interest. To combat class imbalance the machine learning community has relied upon embedded, data preprocessing and ensemble learning approaches. Exploratory research has linked several factors that perpetuate the issue of misclassification in class imbalanced data. However, there remains a lack of understanding between the relationship of the learner and imbalanced data among the competing approaches. The current landscape of data preprocessing approaches have appeal due to the ability to divide the problem space in two which allows for simpler models. However, most of these approaches have little theoretical bases although in some cases there is empirical evidence supporting the improvement. The main goals of this research is to introduce newly proposed a priori based re-sampling methods that improve concept learning within class imbalanced data. The results in this work highlight the robustness of these techniques performance within publicly available data sets from different domains containing various levels of imbalance. In this research the theoretical and empirical reasons are explored and discussed

Voluntary Environmental Regulation in Developing Countries: Mexico's Clean Industry Program

Because conventional command-and-control environmental regulation often performs poorly in developing countries, policymakers are increasingly experimenting with alternatives, including voluntary regulatory programs. Research in industrialized countries suggests that such programs are sometimes ineffective because they mainly attract relatively clean participants free-riding on unrelated pollution control investments. We use plant-level data on more than 100,000 facilities to analyze the Clean Industry Program, Mexico’s flagship voluntary regulatory initiative. We seek to identify the drivers of participation and to determine whether the program improves participants’ environmental performance. Using data from the program’s first decade, we find that plants recently fined by environmental regulators were more likely to participate, but that after graduating from the program, participants were not fined at a substantially lower rate than nonparticipants. These results suggest that although the Clean Industry Program attracted dirty plants under pressure from regulators, it did not have a large, lasting impact on their environmental performance.voluntary environmental regulation, duration analysis, propensity score matching, Mexico

Molecular identification of Trichoderma spp. in garlic and onion fields and In Vitro antagonism trials on Sclerotium cepivorum

Artículo científicoTrichoderma species are non-pathogenic microorganisms that protect against fungal diseases and contribute to increased crop yields. However, not all Trichoderma species have the same effects on crop or a pathogen, whereby the characterization and identification of strains at the species level is the first step in the use of a microorganism. The aim of this study was the identification – at species level – of five strains of Trichoderma isolated from soil samples obtained from garlic and onion fields located in Costa Rica, through the analysis of the ITS1, 5.8S, and ITS2 ribosomal RNA regions; as well as the determination of their individual antagonistic ability over S. cepivorum Berkeley. In order to distinguish the strains, the amplified products were analyzed using MEGA v6.0 software, calculating the genetic distances through the Tamura-Nei model and building the phylogenetic tree using the Maximum Likelihood method. We established that the evaluated strains belonged to the species T. harzianum and T. asperellum; however it was not possible to identify one of the analyzed strains based on the species criterion. To evaluate their antagonistic ability, the dual culture technique, Bell’s scale, and the percentage inhibition of radial growth (PIRG) were used, evidencing that one of the T. asperellum isolates presented the best yields under standard, solid fermentation conditions

Incidencia de la reducción de la tarifa eléctrica en los costos de producción de las MIPYME del sector panificación del municipio de Estelí, año 2015

El sector panificación es una de las ramas del sector industrial del municipio de Estelí. Es el principal producto que ha impulsado la economía del municipio de Estelí y del país pero en estos últimos años ha sufrido varios problemas. El principal problema que presentan las panaderías es el incremento de la tarifa eléctrica y los altos costos de la materia prima, debido a esto es que el Gobierno a través de la Asamblea Nacional y el INE establecieron una reducción del 8 al 10% con el fin de ayudar a las empresas para amortiguar un poco sus costos. (La PRENSA, 2015) El municipio de Estelí se destaca por ser la segunda ciudad con más comercio después de Managua, donde las panaderías han generado un aporte significativo al crecimiento de la economía local. El presente documento es el resultado de la investigación llevada a cabo en el municipio de Estelí, en la que se identificaron problemáticas que enfrenta el sector panificación, y su incidencia en la economía del país. El primer capítulo presenta de manera general antecedentes, planteamiento del problema y justificación de la investigación; en el segundo capítulo, se plantean los objetivos que delimitan el alcance del estudio. En el capítulo tres se desarrolla el marco conceptual en el que se definen los principales elementos a analizar, tomando como referencia fuentes primarias y secundarias de información; elementos tales como: tarifa de energía eléctrica, costos, productividad, empresa, particularidades del sector panificación, entre otros. En los capítulos cuatro y cinco se plantea la hipótesis y se desarrolla el diseño metodológico respectivamente, este último basado en la aplicación de instrumentos a empresarios del sector panificación del municipio de Estelí en el año 2015. En el capítulo seis se procesó y analizó la información recolectada de la encuesta y entrevistas a las empresas del sector panificación del municipio de Estelí

Code Churn Dashboard

This project was conducted with Microsoft in Cambridge, Massachusetts. The purpose was to design and implement a tool that would allow users to easily identify which parts of a software project had high levels of code churn. The tool we developed interfaces with Microsoft\u27s internal source control systems, calculates churn measures for each file, and makes the churn data available through a web interface. By analyzing this churn data, software developers can identify areas of code likely to contain defects

Aerodynamic evaluation with cfd of tip devices in blade for wind turbine

 La región de la punta en las aspa de un rotor eólico se presenta el fenómeno de arrastre inducido, el cual disminuye la eficiencia aerodinámica de la turbina  e incrementa los esfuerzos sobre la estructura. En este trabajo, se analizan computacionalmente (CFD) diferentes dispositivos de punta de aspa, con base en aplicaciones similares como Winglets, Split-Tips, Tip-Tanks, como alternativa de mejora de la aerodinámica. El Reynolds utilizado fue de Re =140000 y modelo RANS de turbulencia K-e, el ángulo de ataque (alfa) fue variado desde -25° hasta 25°. El análisis de los resultados mostró, respecto al aspa con punta base (sin modificación), incremento porcentual del coeficiente de sustentación (CL) así: Split-Tips = 3% Winglet = 4.6%, la punta tipo Tip-Tank no presentó mejora apreciable, La intensidad del vórtice de punta de aspa también mostró relación directa (incremento/disminución) cuando fue comparado con la variación del CD. Palabras clave: CFD, Punta de aspa, Vórtices, Winglets, HAWT

Control de calidad en el proceso de producción de hongos entomopatógenos y antagonistas mediante fermentación en sustrato sólido.

Proyecto de Graduación (Bachillerarato en Ingeniería en Biotecnología) Instituto Tecnológico de Costa Rica, Escuela de Biología, 2002.Ante la problemática de la contaminación y los riesgos a la salud ocasionados por el uso irracional de pesticidas surgió la opción del control biológico de plagas como sistema de producción sano y ecológicamente equilibrado. La gran demanda de productos orgánicos ha provocado la llegada de productos de control orgánico. En nuestro país el Instituto Nacional de Aprendizaje ha desarrollado una serie de productos de este tipo y se ha iniciado un proceso de control de calidad de los mismos. El objetivo fundamental de este proceso es aplicar normas internacionales de calidad de bioproductos producidos por fermentación en sustrato sólido, con el fin de brindar un producto a los capacitados del Instituto y al productor en general. Para esto se ha realizado una revisión del proceso de producción, así como pruebas de concentración, pureza, efectividad y germinación in vitro. Los resultados obtenidos en todas las pruebas confirman la alta calidad de estos productos y los colocan en un nivel semejante a los producidos en países potencias del control biológico como Cuba, Colombia, Australia, España, Alemania y Ucrania. Este trabajo es considerado un primer paso de estandarización de métodos y estándares con el fin de desarrollar la implementación a corto plazo de un sistema de calidad que permita la certificación del laboratorio