First record of a tropical shallow water barnacle Tetraclita sp. (Cirripedia: Tetraclitoidea) from the middle Neogene of the Canary Islands

This paper describes the first record of the intertidal, tropical tetraclitoid barnacle Tetraclita sp. cf. T. stalactifera (Lamarck, 1818) from the middle Neogene of the Canary Islands. The barnacles were recovered as isolated plates from a bioclastic volcanic agglomerate. Associated fauna in- cludes patellid and neritid gastropods, and an oyster bank, which confirm a shallow-water litoral setting. Living Tetraclita stalactifera is recorded from tropical waters of the America, South Africa and the Arabian Sea; it is first recorded as fossil from Plio-Pleistocene of Curaçao (Caribbean Sea, Venezuela)

Parasitismo de Oreotrochilus leucopleurus (Trochilidae) en la Reserva Provincial de San Juan, Argentina

El conocimiento en ectoparásitos de aves silvestres es fragmentario, a pesar de que el parasitismo en este grupo de vertebrados es omnipresente. El ácaro rojo, Dermanyssus sp, es un parásito obligado de aves silvestres y domésticas. Ocasionalmente infesta mamíferos, incluidos perros, gatos, caballos, ganados y roedores. Este género representa gran importancia en medicina veterinaria para América Latina y cuya distribución se extiende en todo el mundo.En este sentido, el objetivo del trabajo fue determinar el ectoparasitismo en el picaflor andino Oreotrochilus leucopleurus en el centro oeste de Argentina. Se determinó la presencia de ninfas de Dermanyssus sp mediante muestras obtenidas de un nido de O. leucopleurus a 3500 metros de altitud. Nuestro estudio representa el primer registro de este parásito en O. leucopleurus, contribuyendo al conocimiento del parasitismo en aves silvestres

Synthesis Of Ag@silica Nanoparticles By Assisted Laser Ablation

This paper reports the synthesis of silver nanoparticles coated with porous silica (Ag@Silica NPs) using an assisted laser ablation method. This method is a chemical synthesis where one of the reagents (the reducer agent) is introduced in nanometer form by laser ablation of a solid target submerged in an aqueous solution. In a first step, a silicon wafer immersed in water solution was laser ablated for several minutes. Subsequently, an AgNO3 aliquot was added to the aqueous solution. The redox reaction between the silver ions and ablation products leads to a colloidal suspension of core-shell Ag@Silica NPs. The influence of the laser pulse energy, laser wavelength, ablation time, and Ag+ concentration on the size and optical properties of the Ag@Silica NPs was investigated. Furthermore, the colloidal suspensions were studied by UV-VIS-NIR spectroscopy, X-Ray diffraction, and high-resolution transmission electron microscopy (HRTEM).10Mexican founding agency CONACyT [CB183728, CB 176705]Instituto Politecnico Nacional [SIP20130216, SIP20141409, SIP 20151327]Brasilian founding agency FACEPEConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

A finite element approach to model high-velocity impact on thin woven GFRP plates

A finite element model to predict the ballistic behaviour of woven GFRP laminates is presented. This finite element model incorporates a new constitutive model based on a continuum damage mechanics approach able to predict the performance of these laminates under high-velocity impacts. The material parameters of the model are identified from the literature and original experiments conducted in this work. The predictive capability of the model is verified against experimental impact tests. Finally, the model is used to analyse the influence of laminate thickness on different energy absorption mechanisms at velocities near the ballistic limit. This analysis allows for the determination of the principal deformation and failure mechanisms governing the perforation process.L. Alonso, S.K.García Castillo and C.Navarro are indebted to the project 'Acción Estratégica en Materiales Compuestos y Análisis Numérico simplificado de Estructuras y protecciones ligeras sometidas a impacto balístico' (2010/00309/002) of the University Carlos III of Madrid for the financial support of this work. F. Martínez-Hergueta acknowledges support from PECRE1819_02 from the Scottish Research Partnership in Engineering. D. Garcia-Gonzalez acknowledges support from the Talent Attraction grant (CM 2018 - 2018-T2/IND-9992) from the Comunidad de Madrid

The Neotropical species of Clistopyga (Hymenoptera, Ichneumonidae, Pimplinae). Part I: the C. chaconi species group, with the description of eleven new species

The New World Clistopyga chaconi species group is revised. Eleven species are described as new: C. amazonica sp. nov., C. cinnamoptera sp. nov., C. cuscoensis sp. nov., C. hayesiana sp. nov., C. melanoptera sp. nov., C. misionensis sp. nov., C. mocaguae sp. nov., C. orellanae sp. nov., C. porteri sp. nov., C. rondoniae sp. nov. and C. yabuquensis sp. nov. Additional morphological data are provided for the previously known species, C. caramba Castillo & Saaksjarvi and C. chaconi Gauld. An illustrated identification key to all species of the group is provided. The Clistopyga chaconi species group appears to be most diverse at the Andean and Amazonian interface in western South America

Científicos jóvenes y sonrientes : la imagen de científico de los estudiantes chilenos de 11° y 12° grado en diferentes contextos escolares

Con el objetivo de conocer la imagen que estudiantes secundarios chilenos de diferentes contextos escolares (privado, público, subvencionado) tienen acerca de los científicos, es que se aplicó a una muestra de 438 estudiantes de 11. y 12.grado de la Región de Valparaíso (Chile) el Draw a Scientist Test (DAST; Chambers, 1983). Para el análisis se utilizaron criterios propuestos en la literatura, además de criterios levantados por el equipo de investigación. Los resultados muestran una imagen altamente estereotipada de científico (varones de raza blanca que trabajan solos y dentro de un laboratorio, usan delantal y gafas), además de algunos indicadores alternativos, como científicos jóvenes y sonrientes. Contrario a lo que describe la literatura, no se encontraron diferencias significativas entre tipos de establecimiento, salvo en algunos indicadores alternativos

Effects of Low-Energy Laser Irradiation on Sperm Cells Dynamics of Rabbit (Oryctolagus Cuniculus)

Infertility is a world disease in which a couple is unable to achieve pregnancy. There are numerous parameters to determinate fertility; nevertheless, sperm motility is by consensus one of the most important attributes to evaluate male fertility. Contributions to a better understanding of this crucial parameter are imperative; hence, the aim of this investigation was to assess the effect of low-energy laser irradiation on sperm cell dynamics in thawed samples that were cryopreserved. We used a 405 nm blue laser beam to irradiate spermatic cells from rabbit inside a temperature-controlled dispersion chamber at 37 °C; then, we applied an image recognizing system to calculate individual sperm trajectories and velocities. We found that sperms raise its motility after irradiation suggesting that λ=405 nm is an optimal wavelength for spermatic photo-stimulation

The endothelial glycocalyx prefers albumin for evoking shear stress-induced, nitric oxide-mediated coronary dilatation

Background: Shear stress induces coronary dilatation via production of nitric oxide ( NO). This should involve the endothelial glycocalyx ( EG). A greater effect was expected of albumin versus hydroxyethyl starch ( HES) perfusion, because albumin seals coronary leaks more effectively than HES in an EG-dependent way. Methods: Isolated hearts ( guinea pigs) were perfused at constant pressure with Krebs-Henseleit buffer augmented with 1/3 volume 5% human albumin or 6% HES ( 200/0.5 or 450/0.7). Coronary flow was also determined after EG digestion ( heparinase) and with nitro-L-arginine ( NO-L-Ag). Results: Coronary flow ( 9.50 +/- 1.09, 5.10 +/- 0.49, 4.87 +/- 1.19 and 4.15 +/- 0.09 ml/ min/ g for `albumin', `HES 200', `HES 450' and `control', respectively, n = 5-6) did not correlate with perfusate viscosity ( 0.83, 1.02, 1.24 and 0.77 cP, respectively). NO-L-Ag and heparinase diminished dilatation by albumin, but not additively. Alone NO-L-Ag suppressed coronary flow during infusion of HES 450. Electron microscopy revealed a coronary EG of 300 nm, reduced to 20 nm after heparinase. Cultured endothelial cells possessed an EG of 20 nm to begin with. Conclusions: Albumin induces greater endothelial shear stress than HES, despite lower viscosity, provided the EG contains negative groups. HES 450 causes some NO-mediated dilatation via even a rudimentary EG. Cultured endothelial cells express only a rudimentary glycocalyx, limiting their usefulness as a model system. Copyright (c) 2007 S. Karger AG, Basel