Quality and quantity: transitions in antimicrobial gland use for parasite defense

Parasites are a major force in evolution, and understanding how host life history affects parasite pressure and investment in disease resistance is a general problem in evolutionary biology. The threat of disease may be especially strong in social animals, and ants have evolved the unique metapleural gland (MG), which in many taxa produce antimicrobial compounds that have been argued to have been a key to their ecological success. However, the importance of the MG in the disease resistance of individual ants across ant taxa has not been examined directly. We investigate experimentally the importance of the MG for disease resistance in the fungus-growing ants, a group in which there is interspecific variation in MG size and which has distinct transitions in life history. We find that more derived taxa rely more on the MG for disease resistance than more basal taxa and that there are a series of evolutionary transitions in the quality, quantity, and usage of the MG secretions, which correlate with transitions in life history. These shifts show how even small clades can exhibit substantial transitions in disease resistance investment, demonstrating that host–parasite relationships can be very dynamic and that targeted experimental, as well as large-scale, comparative studies can be valuable for identifying evolutionary transitions

Efectos agudos de las vibraciones de cuerpo completo sobre variables funcionales en niños con parálisis cerebral

Accésit Congreso SIBB 2015El objetivo del presente estudio fue analizar los efectos agudos de las vibraciones de cuerpo completo (VCC) sobre el equilibrio y la movilidad en niños con parálisis cerebral, y comparar los efectos producidos por el estímulo vibratorio vertical y oscilante sobre las variables mencionadas. Se utilizó un diseño cruzado aleatorio en el que participaron 6 niños y adolescentes con parálisis cerebral. Se llevaron a cabo 5 sesiones de tratamiento, utilizando las dos primeras como familiarización. En cada una de las tres sesiones restantes, el paciente recibía de forma aleatoria un tratamiento de VCC diferente consistentes en 5 series de 1 minuto de vibración seguidas de 1 minuto de descanso. Antes y después de cada intervención se realizaron valoraciones de esfuerzo percibido, equilibrio y movilidad a través de una escala visual analógica y los test de Romberg y timed up and go, respectivamente. La escala visual analógica mostró un incremento del esfuerzo percibido tras la aplicación del tratamiento (+75%, p=0,007). En el equilibrio se observó un aumento en la velocidad de desplazamiento del centro de presiones tras la intervención (+11,3%, p=0,024).Todos los protocolos aplicados en niños y adolescentes con parálisis cerebral, modificaron de manera aguda el equilibrio, no mostrándose cambios respecto a la movilidad. Los resultados del presente estudio demuestran que, el estímulo vibratorio no parece inducir mayores modificaciones sobre el equilibrio y la movilidad que el propio trabajo isométrico sobre la plataforma.Peer ReviewedAward-winnin

Relationship between erythemal UV and broadband solar irradiation at high altitude in Northwestern Argentina

An analysis of the broadband solar irradiation, IT, and the erythemal UV irradiation, IUVER, has been performed using the measurements made from 2013 to 2015 at three sites located at altitudes over 1000 m a.s.l. In Northwestern Argentina (Salta, El Rosal, and Tolar Grande). The main objective of this paper is to determine a relationship between IT and IUVER, which would allow to estimate IUVER from IT in places with few IUVER measurements available, and especially in those where is important to establish adequate photoprotection measures given their dense population and location at high altitude. The relationship between the daily values of IUVER and IT has been fitted to a linear regression (IUVER = m IT + n), showing good correlation in the three measurement sites (R2 ≥ 0.77). Besides, the IUVER/IT ratio shows an increase with altitude of 0.32 ± 0.03 units per km, indicating a more significant influence of altitude on IUVER than on IT. Total ozone column also attenuates more IUVER than IT. In order to reduce the local nature of the relationship between IUVER and IT, the clearness indices kT and kTUVER have been used to obtain a multivariable linear regression of kTUVER as a function of the solar zenith angle, θz, and kT, which shows good correlation (R2 ≥ 0.89) for the three measurement sites

A Single Amino Acid Substitution, Found in Mammals with Low Susceptibility to Prion Diseases, Delays Propagation of Two Prion Strains in Highly Susceptible Transgenic Mouse Models

Specific variations in the amino acid sequence of prion protein (PrP) are key determinants of susceptibility to prion diseases. We previously showed that an amino acid substitution specific to canids confers resistance to prion diseases when expressed in mice and demonstrated its dominant-negative protective effect against a variety of infectious prion strains of different origins and characteristics. Here, we show that expression of this single amino acid change significantly increases survival time in transgenic mice expressing bank vole cellular prion protein (PrP C ), which is inherently prone to misfolding, following inoculation with two distinct prion strains (the CWD-vole strain and an atypical strain of spontaneous origin). This amino acid substitution hinders the propagation of both prion strains, even when expressed in the context of a PrP C uniquely susceptible to a wide range of prion isolates. Non-inoculated mice expressing this substitution experience spontaneous prion formation, but showing an increase in survival time comparable to that observed in mutant mice inoculated with the atypical strain. Our results underscore the importance of this PrP variant in the search for molecules with therapeutic potential against prion diseases

Biological notes on a fungus-growing ant, Trachymyrmex cf. zeteki (Hymenoptera, Formicidae, Attini) attacked by a diverse community of parasitoid wasps (Hymenoptera, Diapriidae)

A number of wasps in the family Diapriidae, subfamily Diapriinae (Proctotrupoidea), are parasitoids that specialize on ant larvae. These wasps are abundant and diverse in the Neotropics, but little is known about their biology. We studied parasitism rates by an array of diapriine wasps that attack the larvae of fungus-growing ants, Trachymyrmex cf. zeteki, in a single population (near Gamboa, Panama). Relatively little is known about the biology and natural history of these ants, so we also present data on colony size and nest architecture. We excavated 136 colonies in central Panama from June to September 2006, and 20 nests from July 2009. We reared six wasp morphotypes; two of them in the genus Mimopriella Masner and Garcia, one Oxypria Kieffer, two Szelenyiopria Fabritius and one Acanthopria Ashmead. The mean intensity of larval parasitism per ant colony was 33.9% (2006), and its prevalence across all ant populations was 27.2% (2006 and 2009). Parasitism rates were not positively correlated with host colony size. A single case of super-parasitism was documented in which two Oxypria males were reared from the same host larva.Museo de La Plat

A beam-beam monitoring detector for the MPD experiment at NICA

The Multi-Purpose Detector (MPD) is to be installed at the Nuclotron Ion Collider fAcility (NICA) of the Joint Institute for Nuclear Research (JINR). Its main goal is to study the phase diagram of the strongly interacting matter produced in heavy-ion collisions. These studies, while providing insight into the physics of heavy-ion collisions, are relevant for improving our understanding of the evolution of the early Universe and the formation of neutron stars. In order to extend the MPD trigger capabilities, we propose to include a high granularity beam-beam monitoring detector (BE-BE) to provide a level-0 trigger signal with an expected time resolution of 30 ps. This new detector will improve the determination of the reaction plane by the MPD experiment, a key measurement for flow studies that provides physics insight into the early stages of the reaction. In this work, we use simulated Au+Au collisions at NICA energies to show the potential of such a detector to determine the event plane resolution, providing further redundancy to the detectors originally considered for this purpose namely, the Fast Forward Detector (FFD) and the Hadron Calorimeter (HCAL). We also show our results for the time resolution studies of two prototype cells carried out at the T10 beam line at the CERN PS complex.Comment: 16 pages, 12 figures. Updated to published version with added comments and correction

Disease management in two sympatric Apterostigma fungus-growing ants for controlling the parasitic fungus Escovopsis

Antagonistic interactions between host and parasites are often embedded in networks of interacting species, in which hosts may be attacked by competing parasites species, and parasites may infect more than one host species. To better understand the evolution of host defenses and parasite counterdefenses in the context of a multihost, multiparasite system, we studied two sympatric species, of congeneric fungus-growing ants (Attini) species and their symbiotic fungal cultivars, which are attacked by multiple morphotypes of parasitic fungi in the genus, Escovopsis. To assess whether closely related ant species and their cultured fungi are evolving defenses against the same or different parasitic strains, we characterized Escovopsis that were isolated from colonies of sympatric Apterostigma dentigerum and A. pilosum. We assessed in vitro and in vivo interactions of these parasites with their hosts. While the ant cultivars are parasitized by similar Escovopsis spp., the frequency of infection by these pathogens differs between the two ant species. The ability of the host fungi to suppress Escovopsis growth, as well as ant defensive responses toward the parasites, differs depending on the parasite strain and on the host ant species

IAA : Información y actualidad astronómica (7)

Sumario : Investigación : Descubrir mundos en tránsito.-- Formación estelar en cúmulos.-- Ventana Abierta: Andalucía investiga.-- Charlas con...Vicente Domingo.-- Actualidad Científica: El Sol en su infancia.-- Una nueva visita cometaria.-- Actividades IAA.-- Agenda.Esta revista se publica con la ayuda de la Acción Especial DIF 2001-4284-E del Programa Nacional de Difusión de la Ciencia y la Tecnología, del Ministerio de Ciencia y Tecnología.N

Medición de radiación eritémica en sitios de altura de la provincia de Salta

Se presentan resultados obtenidos al medir la Irradiancia UV eritémica (UVER) en tres lugares de Salta (Argentina) y que se encuentran a distintas alturas, durante el período Diciembre 2012 - Mayo 2013. El efecto de la altitud se determinó mediante comparación horaria, diaria y promedio mensual de UVER. Las mediciones se realizaron con radiómetros UV-S-E-T de Kipp & Zonen. Los resultados experimentales indican altos valores de UVER en la ciudad de Salta (1.232 m.s.n.m), San Carlos (1.629 m.s.n.m) y El Rosal (3.354 m.s.n.m), alrededor del mediodía solar, con valores promedios entre 3.8 - 5.7 MEDII /hs. Se midió un aumento promedio en la dosis eritémica de un 5 – 8 %/km. Los índices de radiación solar ultravioleta en ausencia de nubosidad superan la calificación de riesgo extremo. Además, se calculan tiempos de exposición de riesgo (fototipos I-IV de Fitzpatrick) y Factores de Protección Solar (FPS) necesarios según la categoría de riesgo.Results obtained by measuring the UV radiation erythematic (UVER) in three places in Salta (Argentina) at different heights, during the period December 2012-May 2013. The effect of altitude was determined by comparing hourly, daily and monthly average UVER. The measurements were performed with UV-S-E-T radiometers Kipp & Zonen. The experimental results indicate high values of UVER in the city of Salta (1,232 m), San Carlos (1,629 m) and El Rosal (3,354 m) around solar noon, with average values between 5.7- 3.8 MEDII / Hs. An average increase in erythemal doses of a 5-8 %/km was measured. The indices of solar ultraviolet radiation in the absence of cloudiness outweigh the extreme risk. Furthermore, risk exposure times are calculated (phototypes I-IV of Fitzpatrick) and Sun Protection Factor (SPF) recommended by risk categoryAsociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Medición de riesgo solar en Salta

El riesgo por exposición a radiación solar en una región se mide calculando el índice Solar Ultravioleta Eritémico (IUV). Este califica el riesgo solar desde bajo (0-2), hasta extremo (11-o más) según la Organización Mundial de la Salud (OMS). En este trabajo se presentan datos de IUV medidos en Salta, Argentina (24.7287 S, 65.4096 W, 1232 m.s.n.m.), durante el período Diciembre 2012 -Julio 2013. Los datos se tomaron con un radiómetro ultravioleta eritémico de Kipp & Zonen. Los resultados indican elevados valores de IUV en la ciudad de Salta alrededor del mediodía solar, con valores altos (5 11). Además, se calculan tiempos de exposición de riesgo para el fototipo cutáneo II de Fitzpatrick y Factores de Protección Solar (FPS) recomendados según la categoría de riesgo.The risk of exposure to solar radiation in a region is measured by calculating the Solar UV Index Erythemic (UVI). This index rates the solar risk from low (0-2) to extreme (11 or more) according to the World Health Organization (WHO). In this paper, UVI data is measured in Salta, Argentina (24.7287 S, 65.4096 W, 1232 m), along the period December 2012-July 2013. UV radiometer erythemic (UVER) Kipp & Zonen was used. The results show high UVI values in the city of Salta around solar noon, with high values (5 ≤ UVI <7), very high (7 ≤ UVI <11) and extreme (UVI ≥ 11). Furthermore, risk exposure times are calculated for phototype II and Sun Protection Factor (SPF) recommended according to risk category.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES