Transplacental transmission of field and rescued strains of BTV-2 and BTV-8 in experimentally infected sheep

Transplacental transmission of bluetongue virus has been shown previously for the North European strain of serotype 8 (BTV-8) and for tissue culture or chicken egg-adapted vaccine strains but not for field strains of other serotypes. In this study, pregnant ewes (6 per group) were inoculated with either field or rescued strains of BTV-2 and BTV-8 in order to determine the ability of these viruses to cross the placental barrier. The field BTV-2 and BTV-8 strains was passaged once in Culicoides KC cells and once in mammalian cells. All virus inoculated sheep became infected and seroconverted against the different BTV strains used in this study. BTV RNA was detectable in the blood of all but two ewes for over 28 days but infectious virus could only be detected in the blood for a much shorter period. Interestingly, transplacental transmission of BTV-2 (both field and rescued strains) was demonstrated at high efficiency (6 out of 13 lambs born to BTV-2 infected ewes) while only 1 lamb of 12 born to BTV-8 infected ewes showed evidence of in utero infection. In addition, evidence for horizontal transmission of BTV-2 between ewes was observed. As expected, the parental BTV-2 and BTV-8 viruses and the viruses rescued by reverse genetics showed very similar properties to each other. This study showed, for the first time, that transplacental transmission of BTV-2, which had been minimally passaged in cell culture, can occur; hence such transmission might be more frequent than previously thought

Suspensão da irrigação durante a maturação de uvas 'Niágara Rosada'.

Na região noroeste de São Paulo, a videira Niágara Rosada (Vitis labrusca) tem sido uma das principais cultivares adotadas pelos produtores locais. Todas as áreas vitícolas, nessa região, são irrigadas devido ao déficit hídrico que ocorre durante o período de produção da cultura. Diversas técnicas podem ser empregadas com o propósito de aumentar a eficiência do uso da água, sendo que a irrigação com déficit hídrico tem sido uma das mais adotadas para a cultura da videira. No presente trabalho, avaliou-se o efeito de diferentes épocas de suspensão da irrigação durante a fase de maturação de uvas da cultivar ?Niágara Rosada? (Vitis labrusca), sob as condições do noroeste paulista. O experimento foi conduzido em área da Estação Experimental de Viticultura Tropical da Embrapa Uva e Vinho, localizada no município de Jales, noroeste do estado de São Paulo. As plantas de ?Niágara Rosada? sobre porta-enxertos ?IAC 572? foram conduzidas no sistema latada e irrigadas por microaspersão. O delineamento estatístico foi em blocos ao acaso com quatro tratamentos e cinco repetições. Os tratamentos avaliados foram: suspensão da irrigação aos 21 dias (T1), 15 dias (T2) e 9 dias (T3) antes da colheita, e irrigação até o final do ciclo da cultura (T4). Foram avaliadas variáveis relacionadas à qualidade dos frutos, como teor de sólidos solúveis, pH, tamanho de bagas e massa de cachos e bagas. Durante o período de avaliação, não ocorreram precipitações pluviais no local do experimento. Não foram encontradas diferenças significativas pelo teste de Tukey, ao nível de 5% de probabilidade, para as variáveis avaliadas. A suspensão da irrigação aos 21 dias (T1) apresentou uma economia de água de 21% em relação ao total aplicado no tratamento sem suspensão da irrigação (T4)

Formação do vinhedo com a cultivar BRS Isis no sistema de sustentação em Y, sobre diferentes porta-enxertos.

O objetivo deste trabalho foi avaliar a interferência de diferentes porta-enxertos na formação da cultivar BRS Isis no sistema de sustentação em Y

Efeito da suspensão da irrigação sobre a incidência de requeima na cultivar de videira Niágara Rosada.

O objetivo deste trabalho é avaliar o efeito da suspensão da irrigação, em diferentes épocas da maturação dos frutos, sobre a ocorrência da requeima das folhas da videira 'Niágara Rosada'

Observing CMB polarisation through ice

Ice crystal clouds in the upper troposphere can generate polarisation signals at the uK level. This signal can seriously affect very sensitive ground based searches for E- and B-mode of Cosmic Microwave Background polarisation. In this paper we estimate this effect within the ClOVER experiment observing bands (97, 150 and 220 GHz) for the selected observing site (Llano de Chajnantor, Atacama desert, Chile). The results show that the polarisation signal from the clouds can be of the order of or even bigger than the CMB expected polarisation. Climatological data suggest that this signal is fairly constant over the whole year in Antarctica. On the other hand the stronger seasonal variability in Atacama allows for a 50% of clean observations during the dry season.Comment: 7 Pages, 4 figure

Road induced edge effects on a forest bird community in tropical Asia

Background: Edge effects cause changes in bird community richness, abundance, and/or distribution within a landscape, but the avian guilds most influenced can vary among regions. Although Southeast Asia has the highest rates of deforestation and projected species loss, and is currently undergoing an explosive growth in road infrastructure, there have been few studies of the effects of forest edges on avian communities in this region. Methods: We examined avian community structure in a dry evergreen forest in northeastern Thailand adjacent to a five-lane highway. We evaluated the richness and abundance of birds in 11 guilds at 24 survey points on three parallel transects perpendicular to the edge. At each point, 10-min surveys were conducted during February‒August 2014 and March‒August 2015. Vegetation measurements were conducted at 16 of the bird survey points and ambient noise was measured at all 24 survey points. Results: We found a strongly negative response to the forest edge for bark-gleaning, sallying, terrestrial, and understory insectivores and a weakly negative response for arboreal frugivore-insectivores, foliage gleaning insectivores, and raptors. Densities of trees and the percentage canopy cover were higher in the interior, and the ambient noise was lower. In contrast, arboreal nectarivore-insectivores responded positively to the forest edge, where there was a higher vegetation cover in the ground layer, a lower tree density, and a higher level of ambient noise. Conclusion: Planners should avoid road development in forests of high conservation value to reduce impacts on biodiversity. Where avoidance is impossible, a number of potential mitigation methods are available, but more detailed assessments of these are needed before they are applied in this region

Are Asian elephants afraid of honeybees? Experimental studies in northern Thailand

This research article published Springer Nature Switzerland AG., 2020In many parts of South and Southeast Asia, rural farmers living at the borders of protected areas frequently encounter Asian elephants (Elephas maximus) raiding their crops and threatening farmers lives and livelihoods. Traditional deterrent methods often have limited success as elephants become habituated or alternate their movement and behavior. While African bees (Apis mellifera scutellate) have been shown to effectively and sustainably deter African elephants (Loxodonta africana) little is known about their Asian counterparts. We conducted two experiments to estimate the effectiveness of bees as an Asian elephant deterrent method. We analyzed the behavioral reaction of seven captive Asian elephants when confronted with a fence of A. mellifera hives blocking their way to a desired source of food. In addition, we explored the defensive reaction of five A. cerana hives and six A. mellifera hives to an artificial disturbance during both day and night time. The elephants crossed the beehive fence in 51% of the cases, the probability of crossing increased over time and the number of exposures had a significant effect on an elephant’s crossing probability, indicating that elephants became habituated to the presence of the beehive fence. In the bee experiment, only one out of five A. cerana hives and one out of six A. mellifera hives reacted to the disturbance during the daytime, while during nighttime, none of them reacted defensively after being disturbed. We, therefore, conclude that neither A. mellifera nor A. cerana bees are likely to be effective in deterring wild Asian elephants from entering crop fields

Monte Carlo Transmission Line Modeling of Multilayer Optical Coatings for Performance Sensitivity of a Dichroic Filter for the ARIEL Space Telescope

Dichroic beamsplitters, or dichroics, are filters that rely on the optical interference that occurs within thin layers to ensure the transmission and reflection of selective wavelengths of an incident beam of light. These optical components consist of a substrate coated on one or both surfaces with multiple layers of thin films, the spectral design and construction of which determine the isolation of particular wavebands. Discrepancies between the measured and expected spectral performance of optical elements with such coatings can largely be attributed to depositions errors and uncertainties in the refractive indices of the materials. Our model uses two-dimensional transmission line modeling to evaluate the transmittance of light through multilayer coatings deposited on a substrate material for given materials, angle of incidence and polarisation. This model allows us to perform Monte Carlo simulations to obtain statistical information about the tolerance of the coating performance to systematic and random uncertainties from the manufacturing process, as well as from environmental changes in space. With the aid of accurate manufacturing recipes and uncertainty amplitudes from commercial manufacturers, this tool can predict variations in the optical performance that result from the propagation of each of these uncertainties for various hypothetical scenarios. One particular application of this study are the dichroics of the ARIEL space telescope. We compare the predicted optical performance with transmission measurements at cryogenic temperatures for one of the ARIEL dichroics, which show the specification compliance of this prototype after many thermal cycles

First evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster

Diffuse synchrotron radio emission from cosmic-ray electrons is observed at the center of a number of galaxy clusters. These sources can be classified either as giant radio halos, which occur in merging clusters, or as mini halos, which are found only in cool-core clusters. In this paper, we present the first discovery of a cool-core cluster with an associated mini halo that also shows ultra-steep-spectrum emission extending well beyond the core that resembles radio halo emission. The large-scale component is discovered thanks to LOFAR observations at 144 MHz. We also analyse GMRT observations at 610 MHz to characterise the spectrum of the radio emission. An X-ray analysis reveals that the cluster is slightly disturbed, and we suggest that the steep-spectrum radio emission outside the core could be produced by a minor merger that powers electron re-acceleration without disrupting the cool core. This discovery suggests that, under particular circumstances, both a mini and giant halo could co-exist in a single cluster, opening new perspectives for particle acceleration mechanisms in galaxy clusters

A CST simulation and performance analysis for a passive façade integratable metamaterials structure

In the case of stone relics with cultural heritage value that are exposed to the adverse effects of direct exposure to weathering, we present a metamaterial with a composite structure that can passively control the transmittance of infrared and visible light. This periodic multi-layer structure consist of metal and dielectric layers, these have the function of low transmittance at infrared wavelengths and high transmittance in visible light. Its spectrally-selective behavior offers the possibility of both temperature regulation and natural daylighting of cultural relics. In addition, it can be discretely integrated with an existing architectural façade to provide weathering protection against rain and snow. Results show the composite structure can not only obtain a band gap width of 109 THz in the near infrared wave-band but also ensure that most of the visible light's transmittance is higher than τ=0.4. Furthermore, since the transmission spectrum is independent of polarization angle, the cultural relics benefit from its spectral-selective properties regardless of the polarization angle due to the sun's position