2,763 research outputs found
Molecular characterization of Portuguese populations of the pinewood nematode Bursaphelenchus xylophilus using cytochrome b and cellulase genes
Bursaphelenchus xylophilus is the causal agent of pine wilt disease and a
worldwide pest with high economic impact. Since its first diagnosis in Portugal
in 1999, it has been subjected to quarantine measures with impact on forest
health and ecosystem stability, significantly affecting international trade of wood
products. The disease was detected in the north and centre of continental
Portugal and, since 2008, the whole country has been considered an affected
area. Recently, it was detected in Madeira Island. In order to avoid new
outbreaks, it has become of major importance to understand the patterns of
spread, introduction points and to characterize the new populations from
continental Portugal and Madeira Island. Mitochondrial cytochrome b (cytb) and
parasitic cellulase gene sequences were used to evaluate the genetic
relationships among isolates that could indicate possible origins of the new
outbreaks. Portuguese isolates were compared with isolates from USA, China,
Japan and South Korea, in order to investigate possible infection pathways and
disease spread patterns in Portugal. Phylogenetic trees based on both genes
show that Portuguese isolates group with Asian isolates. Isolates from USA are
in a separate position in both gene trees. However, the phylogenetic tree based
on the cellulase gene sequences shows higher differentiation among Portuguese
isolates than that of cytb. These results agree with those previously obtained
using inter-simple sequence repeats (ISSR). This was the first study to use cytb
and cellulase genes to characterize pinewood nematode (PWN) populations.
This study suggests that cellulase is a better marker than cytb to study genetic
diversity in B. xylophilus
Towards End-to-End Acoustic Localization using Deep Learning: from Audio Signal to Source Position Coordinates
This paper presents a novel approach for indoor acoustic source localization
using microphone arrays and based on a Convolutional Neural Network (CNN). The
proposed solution is, to the best of our knowledge, the first published work in
which the CNN is designed to directly estimate the three dimensional position
of an acoustic source, using the raw audio signal as the input information
avoiding the use of hand crafted audio features. Given the limited amount of
available localization data, we propose in this paper a training strategy based
on two steps. We first train our network using semi-synthetic data, generated
from close talk speech recordings, and where we simulate the time delays and
distortion suffered in the signal that propagates from the source to the array
of microphones. We then fine tune this network using a small amount of real
data. Our experimental results show that this strategy is able to produce
networks that significantly improve existing localization methods based on
\textit{SRP-PHAT} strategies. In addition, our experiments show that our CNN
method exhibits better resistance against varying gender of the speaker and
different window sizes compared with the other methods.Comment: 18 pages, 3 figures, 8 table
Bursaphelenchus antoniae sp. n. (Nematoda: Parasitaphelenchidae) associated with Hylobius sp. from Pinus pinaster in Portugal
Bursaphelenchus antoniae sp. n. is described and illustrated. Dauer juveniles were isolated from the body of the large pine
weevil, Hylobius sp., collected from maritime pine (Pinus pinaster) stumps, in Portugal. Bursaphelenchus antoniae sp. n. was reared
and maintained in P. pinaster wood segments and on Petri dish cultures of the fungi Botrytis cinerea and Monilinia fructicola. The new
species is characterised by a relatively small body length of ca 583 μm (females) and 578 μm (males), a lateral field with two incisures,
presence of a small vulval flap and a conoid female tail with a rounded or pointed terminus. Males have stout spicules with a disc-like
cucullus and seven caudal papillae arranged as a single midventral precloacal papilla, one precloacal pair and two postcloacal pairs. In
the character of the lateral field, B. antoniae sp. n. comes close to B. abietinus, B. rainulfi and B. hylobianum, whilst spicule characters
place it within the piniperdae-group sensu Ryss et al. Morphologically, B. antoniae sp. n. is closest to B. hylobianum; the spicules of
these two species having flattened, wing-like, alae on the distal third of the lamina. Bursaphelenchus antoniae sp. n. is distinguished
from B. hylobianum on the arrangement of the caudal papillae (two vs three pairs). ITS-RFLP profiles and the failure to hybridise
support the separation of the two species. Phylogenetic analysis of the new species, based on the 18S rDNA sequence, supports the
inclusion of this new species in the B. hylobianum-group sensu Braasch. Sequence analysis of the 28S rDNA D2/D3 domain did not
place the new species in a definite group
La iglesia visigoda de Morón de la Frontera
La iglesia visigoda de Morón de la Frontera (Sevilla) constituye un hallazgo de gran interés para
el conocimiento del proceso de cristianización de la comarca sur de la provincia de Sevilla. A
lo largo de las siguientes páginas abordaremos el estudio e interpretación de los restos arquitectó-
nicos de la basílica y de los principales materiales recuperados durante su excavación.The di scovery of a visigothic church in Moron de la Frontera (Seville) has been of great interest
for the knowledge of the Christianization process in the south district of the county of Seville.
Along the following pages we will tackle the study and interpretation of the architectural remains
of the basilica and the main materials recovered during the excavation
Detailed morphobiometric studies of Bursaphelenchus xylophilus and characterisation of other Bursaphelenchus species (Nematoda: Parasitaphelenchidae) associated with Pinus pinaster in Portugal
Detailed studies on Bursaphelenchus xylophilus are provided in this contribution. Comparative observations
between field and cultured populations of this species demonstrated significant size differences: cultured specimens
overall displayed larger size in all morphometric parameters. A principal component analysis (PCA) of the individuals
undergoing moulting allowed their separation in four groups namely J2-J3, J3-J4, J4F-F, and J4M-M; gonad length mean values
of these four groups made possible to distinguish the non-moulting groups J2, J3, J4F, J4M and adults. Seven Bursaphelenchus
species (B. hellenicus, B. leoni, B. pinasteri, B. sexdentati, B. teratospicularis, B. tusciae and B. xylophilus), associated with Pinus
pinaster in Portugal, were charaterized, including biometrical measurements and ratios as well excised spicules observed
under SEM; furthermore, B. hellenicus, B. pinasteri, B. sexdentati, B. tusciae and B. xylophilus were characterised on the
basis of their ITS-RFLP profiles. B. sexdentati and B. xylophilus were the only species found in high numbers in some of
the samples
Assessments of an Exogenous Proteolytic Enzyme in Beef Steer Diets to Improve Growth Performance and Ruminal fermentation
A series of experiments were conducted to investigate the effects of adding an exogenous proteolytic enzyme (EPE) on the growth performance of beef steers fed growing and finishing diets containing 30% dried distillers grains with solubles (DDGS; Exp. 1), and results corroborated by in vitro ruminal fermentation in continuous cultures (Exp. 2). In Exp. 1, 48 group-penned Angus crossbred steers were randomly assigned to 2 treatments (n = 6) in a completely randomized design: DDGS TMR (DT) without and with EPE (27 mg of azocasein hydrolyzed/min/kg DM TMR). The addition of EPE during the growing phase increased DMI (P = 0.02), but had no effects on final BW, BW change, ADG, and G:F. Adding EPE during the growing phase decreased NDF digestibility, whereas the digestibility of DM, CP, and ADF were not affected. There was a tendency for both ADG (P = 0.09) and final BW (P = 0.11) to increase during the finishing phase without affecting BW change and G:F. As opposed to the growing phase, EPE increased digestibility (P \u3c 0.04) of DM, CP, NDF, and ADF. In Exp. 2, 4 dietary treatments were assessed in continuous cultures; non-DDGS TMR (NDT) or DT finishing beef steer diet was combined without or with EPE in a 2 × 2 factorial design. The DT was the same diet used as the finishing diet in Exp. 1, and dose rate of EPE was the same as Exp. 1. Feeding the DT increased total VFA concentration (P = 0.01) which corresponded with a decreased (P \u3c 0.01) pH compared with the NDT diet (5.8 vs. 6.0) regardless of EPE supplementation. Supplementing EPE tended to increase (P = 0.07) the total VFA concentration in both diets, but only increased digestibility of DM, OM, and NDF when added to the DT diet (P \u3c 0.05), leading to tendencies on TMR × enzyme interaction (P \u3c 0.10). Addition of the EPE product assessed in this study resulted in positive responses in Exp. 1 and 2 when added to finishing beef steer diets, and thus it is clear that use of protease enzyme products may be more effective in high concentrate diets such as finishing beef steer diets containing DDGS
First report of an entomopathogenic nematode from continental Portugal
In continental Portugal no information is available concerning
the occurrence of entomopathogenic nematodes.
During a survey in several different habitats from the
southern regions of the country, several isolates where
identified as Steinernema feltiae. This represents the first
report of an entomopathogenic nematode genus for continental
Portugal
Comparative analysis of domestic water heating thermosiphon systems tested according to the Standard ISO 9459-2
Permiso concedido para subir el documentoThe Standard ISO 9459-2 is a standard for the characterization of thermal performance of domestic water
heating systems without auxiliary heating. In this study, 18 domestic water heating thermosiphon systems
have been tested according to this international standard. The objective of the paper is to carry out a
comparative analysis of the results obtained in these systems as a function of their volume and type of heat
exchanger (tubular and double jacket). A comparative analysis of systems performance will be carried out by
calculating the performance without thermal loss (a1/A) and solar fraction fSOL in different reference locations
for different volume/area ratios. Also, a comparative analysis of systems performance and solar fraction will
be carried out at different locations between a tubular heat exchanger tank and a double jacket heat
exchanger tank. The different values obtained will be compared for the storage tank’s heat loss coefficient
(Us). It will determinate the useful energy (energy with temperature above 45ºC) for the degree of mixing in
the storage tank during a draw-off test
Urban combat in Late Middle Ages: the Duke of Medina Sidonia against the Marquis of Cadiz for the Control of Seville
La falta de perspectiva histórica hace que algunos consideren el combate urbano como un fenómeno moderno, y otros lo ignoren o lo incluyan dentro de la guerra de asedio. Este trabajo analiza un episodio de la lucha de bandos acaecido en Sevilla, la ciudad más poblada de la Castilla bajomedieval. A través del estudio de los factores que intervienen en su génesis, desarrollo y consecuencias, pretendemos aproximarnos a un mejor conocimiento de esta sociedad, sometida a los linajes y curtida en la guerra de frontera.The lack of historical perspective has led some scholars to consider urban warfare as a modern phenomenon, while others ignore it or regard it as a part of siege warfare. This paper examines an event that took place during the fighting between factions in Seville, the most populated city of late medieval Castile. By studying the factors that originated this urban combat in particular, as well as its development and consequences, we seek to better understand the society that was subject to the confronting families and endured the ordeals of a frontier war
The Climate of Medieval Madrid as Deduced From Documents and the “Libro de la Montería” (14th-16th Centuries)
El presente trabajo pretende analizar cuáles eran las características climáticas que se sucedían en Madrid y su Tierra a lo largo del año, fundamentalmente entre los siglos XIV y XVI. Se intentará comprobar, dentro de las limitaciones que impone la documentación de la época, si en aquel tiempo se daba también un clima mediterráneo, o no, y si este ha variado mucho desde entonces. Igualmente se podrá comprobar algo que tal vez podría, aunque no debería, sorprendernos: el hombre medieval tenía muy claros muchos conceptos meteorológicos y climatológicos, aunque siempre aprehendidos con una finalidad práctica, para aplicarlos en su vida cotidiana tan cercana y dependiente de la naturaleza.This paper analyses climatic characteristics in Madrid and surroundings throughout the year between the 14th and 16th centuries. Within the constraints imposed by the contemporary documentation available, the aim is to determine whether or not a Mediterranean climate existed in the Middle Ages, and if the characteristics of this climate have changed. In addition, I shall demonstrate that medieval people had a clear understanding of meteorological and climatic concepts, although these were applied for practical purposes in a daily life closely associated with nature and the environment
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