Lack of correlation between vertical distribution and carrier frequency, and preference for open spaces in arboreal katydids that use extreme ultrasound, in Gorgona, Colombia (Orthoptera: Tettigoniidae)

Male Tettigoniidae emit sound to attract conspecific females. The sound is produced by stridulation. During stridulation the forewings open and close, but it is during the closing stroke that the scraper contacts the file teeth to generate the predominant sound components, which are amplified by adjacent wing cells specialized in sound radiation. The sounds usually exceed the sonic boundary and might occur above 40 kHz, reaching extreme ultrasonic frequencies of 150kHz in some species. Here we test the hypothesis that Tettigoniidae species should prefer microhabitats that favour efficient signal transmission, i.e. that there is a relationship of sound frequency with the vertical distribution of the species (from ground to canopy) at Gorgona National Natural Park, Colombia. We sampled 16 trees and four different altitudinal levels between 1 and 20m above the understory vegetation. We placed collecting blankets separated by vertical distances of 5m, and knocked insects down using the technique known as fogging. We found no correlation between vertical distribution and carrier frequency, but there was a preference for open spaces (below the canopy and above the understory) in species using extreme ultrasound. This is the first quantitative description of the vertical distribution in neotropical species of the family Tettigoniidae and its relationship to the calling song frequency

Shrinking wings for ultrasonic pitch production: hyperintense ultra-short-wavelength calls in a new genus of neotropical katydids (Orthoptera: tettigoniidae)

This article reports the discovery of a new genus and three species of predaceous katydid (Insecta: Orthoptera) from Colombia and Ecuador in which males produce the highest frequency ultrasonic calling songs so far recorded from an arthropod. Male katydids sing by rubbing their wings together to attract distant females. Their song frequencies usually range from audio (5 kHz) to low ultrasonic (30 kHz). However, males of Supersonus spp. call females at 115 kHz, 125 kHz, and 150 kHz. Exceeding the human hearing range (50 Hz–20 kHz) by an order of magnitude, these insects also emit their ultrasound at unusually elevated sound pressure levels (SPL). In all three species these calls exceed 110 dB SPL rms re 20 µPa (at 15 cm). Males of Supersonus spp. have unusually reduced forewings (<0.5 mm2). Only the right wing radiates appreciable sound, the left bears the file and does not show a particular resonance. In contrast to most katydids, males of Supersonus spp. position and move their wings during sound production so that the concave aspect of the right wing, underlain by the insect dorsum, forms a contained cavity with sharp resonance. The observed high SPL at extreme carrier frequencies can be explained by wing anatomy, a resonant cavity with a membrane, and cuticle deformation

UTILIZING CHERNOFF FACES IN MODELING RESPONSES IN THE EVALUATION OF TRIMESTER SCHEME IMPLEMENTATION

This study uses Chernoff faces to model the responses of students, faculty, and administration staff of a teacher education institution in Manila, Philippines, to the implementation of an Outcomes-Based Teacher Education Curriculum (OBTEC) trimester scheme. Chernoff faces provide a valuable representation to model responses because people are used to studying and reacting to faces. This study used a quantitative research method by analyzing cross-sectional data from the study of the OBTEC trimester scheme. A total of 322 participants were selected through convenience sampling and given a 15-item survey in which possible responses ranged from 1 (strongly disagree) to 6 (strongly agree). The administrators were found to give a generally favorable rating (overall mean = 4.56 agree; overall SD = 0.45) to the OBTEC trimester scheme. The statements most highly rated by the administrators pertain to the success of OBTEC in integrating pedagogical content knowledge training with outcomes-based education, preparation of the students for the teaching profession, and consistency with the K to 12 curriculum. These responses are characterized by the structure of the face, the width of the mouth, and the height of the face, respectively. The most negative aspects of the OBTEC trimester scheme, according to the students, are characterized by hair height, nose width, and a hair style of thin hair that points downward. Chernoff faces were found to be a simple, yet powerful tool to model responses in the evaluation of the OBTEC trimester scheme

The hylEfm gene in pHylEfm of Enterococcus faecium is not required in pathogenesis of murine peritonitis

<p>Abstract</p> <p>Background</p> <p>Plasmids containing <it>hyl</it>_{<it>Efm </it>}(pHyl_Efm) were previously shown to increase gastrointestinal colonization and lethality of <it>Enterococcus faecium </it>in experimental peritonitis. The <it>hyl</it>_{<it>Efm </it>}gene, predicting a glycosyl hydrolase, has been considered as a virulence determinant of hospital-associated <it>E. faecium</it>, although its direct contribution to virulence has not been investigated. Here, we constructed mutants of the <it>hyl</it>_<it>Efm</it>-region and we evaluated their effect on virulence using a murine peritonitis model.</p> <p>Results</p> <p>Five mutants of the <it>hyl</it>_<it>Efm</it>-region of pHyl_EfmTX16from the sequenced endocarditis strain (TX16 [DO]) were obtained using an adaptation of the PheS* system and were evaluated in a commensal strain TX1330RF to which pHyl_EfmTX16was transferred by mating; these include <it>i</it>) deletion of <it>hyl</it>_{<it>Efm </it>}only; <it>ii</it>) deletion of the gene downstream of <it>hyl</it>_{<it>Efm </it>}(<it>down</it>) of unknown function; <it>iii</it>) deletion of <it>hyl</it>_{<it>Efm </it>}plus <it>down</it>; <it>iv</it>) deletion of <it>hyl</it>_<it>Efm</it>-<it>down </it>and two adjacent genes; and <it>v</it>) a 7,534 bp deletion including these four genes plus partial deletion of two others, with replacement by <it>cat</it>. The 7,534 bp deletion did not affect virulence of TX16 in peritonitis but, when pHyl_{EfmTX16Δ7,534}was transferred to the TX1330RF background, the transconjugant was affected in <it>in vitro </it>growth versus TX1330RF(pHyl_EfmTX16) and was attenuated in virulence; however, neither <it>hyl</it>_{<it>Efm </it>}nor <it>hyl</it>_<it>Efm</it>-<it>down </it>restored wild type function. We did not observe any <it>in vivo </it>effect on virulence of the other deletions of the <it>hyl</it>_<it>Efm</it>-region</p> <p>Conclusions</p> <p>The four genes of the <it>hyl</it>_{<it>Efm </it>}region (including <it>hyl</it>_<it>Efm</it>) do not mediate the increased virulence conferred by pHyl_EfmTX16in murine peritonitis. The use of the markerless counterselection system PheS* should facilitate the genetic manipulation of <it>E. faecium </it>in the future.</p

Evaluación del control integrado de plagas en el cultivo de tomate de mesa, con énfasis en el gusano cogollero (Scrobipálpula absoluta)

El cultivo del tomate, es atacado por diferentes especies de insectos plagas que reducen su rendimiento, especialmente del gusano, el cual se considera como el problema entomológico del cultivo presentándose en cualquier etapa del cultivo, tanto en su fase vegetativa como en la fase reproductiva.Tomate-Solanum lycopersicu

CARACTERISTICAS DE CEPAS CHILENAS DE Pyrenochaeta lycopersici Y PERSPECTIVAS DE CONTROL BIOLOGICO

Raíz corchosa es una de las principales enfermedades que afecta al cultivo de tomate que se produce bajo invernadero frío en Chile. En esta investigación se entregan antecedentes referentes a las principalescaracterísticas reproductivas de su agente causal, Pyrenochaeta lycopersici, como: picnidios, conidióforos y conidios. Además, antecedentes sobre la estrategia de control biológico de esta enfermedad. En base a estudios preliminares, se determinó a Trichoderma harzianum, como el taxa más promisorio (según cultivos duales).Se caracterizaron cepas de ambas especies de acuerdo a crecimiento micelial a diferentes temperaturas, pH, y salinidad (NaCl). Finalmente, se efectuó un ensayo bajo condiciones controladas de invernadero, destacándose la cepa Th11 como la más promisoria en el biocontrol de este patógeno

ANÁLISIS GEOPOLÍTICO DE NEGOCIACIÓN DE SANTANDER CON TAILANDIA, MALASIA Y SINGAPUR (Geopolitical Negotiation Analysis of Santander with Thailand, Malaysia and Singapore)

En el siguiente trabajo se realizó un análisis de los factores de poder geopolítico, para identificar las oportunidades de negociación de Santander con los países de Tailandia, Malasia y Singapur. Se identificó que el Departamento de Santander es una región con un gran potencial para entrar al mercado del sudeste asiático, por lo tanto, es fundamental potencializar las oportunidades de negociación de Santander con estos tres países. Para la recolección de la información del trabajo se hizo a partir de análisis comparativos, considerando los factores sociales, económicos, políticos y culturales, determinando que Santander es una región con una oferta exportable diversificada y amplia, la cual puede ser recibida por los mercados de Tailandia, Malasia y Singapur

Optimización de los parámetros de deposición del TiN sobre aceros tipo herramienta obtenidos por la tecnología del magnetrón sputtering

El CDT-ASTIN formuló este proyecto, incorporando una tecnología de punta y la única planta piloto del país para su transferencia al sector productivo y su aplicación en la Formación Profesional que imparte el SENA. Con el objetivo de incrementar la eficiencia y vida útil de las herramientas utilizadas en los diferentes procesos de manufactura de las empresas participantes del proyecto, se fabricaron, mediante un estudio experimental, recubrimientos de nitruro de titanio (TiN) sobre probetas de acero tipo herramienta. Para ello se seleccionaron aceros de las casas fabricantes más relevantes en el medio industrial colombiano, específicamente el acero Thyrodur T-2510 de Ia firma Thyssen, el acero K-460 de Bohler y el acero RUS 3 de la firma Rochling. Posteriormente se efectuaron recubrimientos del mismo material sobre los aceros AISI D3. H13. P20, 420 y M2. Las probetas recubiertas fueron sometidas a diferentes ensayos de caracterización, donde se determinaron propiedades importantes como la dureza, la adherencia, la composición, la morfología y el espesor. Para tal fin se utilizaron técnicas de caracterización tales como la prueba Calote, la prueba de Rayado, el método de Rockwell C, la Perfilometría, la Difracción de Rayos X, la Microscopia Electrónica de Barrido y la Microscópica de Fuerza Atómica. Estas pruebas se realizaron en alianza y colaboración con los laboratorios de Física del Plasma de la Universidad Nacional de Colombia sede Manizales, el Laboratorio de Recubrimientos Duros del Departamento de Física de la Universidad del Valle y el Laboratorio de Metalografía del CDT-ASTIN. Una vez optimizados los parámetros de deposición del TiN se recubrieron las herramientas aportados por las empresas (207 piezas) y se sometieron a las respectivas pruebas de campo, lográndose un incremento de su vida útil que osciló entre 50 y un 600% con una reducción de los costos de producción de más del 40%