19 research outputs found
Spatio-temporal optimization of sampling for bluetongue vectors (<em>Culicoides</em>) near grazing livestock
BACKGROUND: Estimating the abundance of Culicoides using light traps is influenced by a large variation in abundance in time and place. This study investigates the optimal trapping strategy to estimate the abundance or presence/absence of Culicoides on a field with grazing animals. We used 45 light traps to sample specimens from the Culicoides obsoletus species complex on a 14 hectare field during 16 nights in 2009. FINDINGS: The large number of traps and catch nights enabled us to simulate a series of samples consisting of different numbers of traps (1-15) on each night. We also varied the number of catch nights when simulating the sampling, and sampled with increasing minimum distances between traps. We used resampling to generate a distribution of different mean and median abundance in each sample. Finally, we used the hypergeometric distribution to estimate the probability of falsely detecting absence of vectors on the field. The variation in the estimated abundance decreased steeply when using up to six traps, and was less pronounced when using more traps, although no clear cutoff was found. CONCLUSIONS: Despite spatial clustering in vector abundance, we found no effect of increasing the distance between traps. We found that 18 traps were generally required to reach 90% probability of a true positive catch when sampling just one night. But when sampling over two nights the same probability level was obtained with just three traps per night. The results are useful for the design of vector monitoring programmes on fields with grazing animals
PDE4 inhibition enhances hippocampal synaptic plasticity in vivo and rescues MK801-induced impairment of long-term potentiation and object recognition memory in an animal model of psychosis
Inhibition of phosphodiesterase type 4 (PDE4) by rolipram (4-(3-(cyclopentyloxy)-4-methoxyphenyl)-pyrrolidin-2-one) has been the focus of many behavioral and molecular studies in the recent years. Rolipram exhibits memory-enhancing effects in rodents. In vitro studies have shown that long-term potentiation (LTP), which may comprise a cellular substrate for learning, is also enhanced by rolipram. However, effects have not been assessed in vivo. Rolipram has antipsychotic properties. Psychosis affects cognition and in animal models of psychosis LTP is impaired. In this study, we investigated if PDE4 inhibition improves LTP in healthy animals in vivo and if PDE4 inhibition rescues impaired LTP and prevents object recognition memory deficits in an animal model of psychosis. Recordings were made from the hippocampus of adult, freely behaving Wistar rats. Thirty minutes after treatment with rolipram or vehicle, a tetanus was applied to the medial perforant path to elicit short-term potentiation (STP) in the dentate gyrus. At this time-point, radioimmunoassay revealed that rolipram significantly elevated cyclic adenosine monophosphate levels in the dorsal hippocampus, in line with reports by others that rolipram mediates decreased PDE4 activity. In healthy animals, both intracerebroventricular and subcutaneous treatment with rolipram facilitated STP into LTP, suggesting that PDE4 inhibition may have a permissive role in plasticity mechanisms that are relevant for learning and memory. One week after a single systemic treatment with the irreversible N-methyl--aspartate antagonist, MK801, LTP and object recognition memory were significantly impaired, but could be rescued by PDE4 inhibition. These data suggest that the relief of cognitive disturbances in psychosis models by rolipram may be mediated in part by a rescue of hippocampal LTP
Multigene phylogenies of Ophiostomataceae associated with Monterey pine bark beetles in Spain reveal three new fungal species
Ophiostoma species, some of which cause
sapstain in timber and/or are mild pathogens, are
common fungal associates of bark beetles (Coleoptera:
Scolytinae). Three new Ophiostomataceae from
Spain are recognized in the present study based on
comparisons of sequence data for three gene regions
as well as morphological characteristics. The new taxa
are described as Ophiostoma nebulare sp. nov.,
Ophiostoma euskadiense sp. nov. and Graphilbum
crescericum sp. nov.National Research Foundation, members of the Tree Protection Co-operative Programme (TPCP), the Department of Education, Universities and Research of Basque Government, and the NRF/DST Center of Excellence in Tree Health Biotechnology (CTHB).http://www.mycologia.orghb201
A genetically homogenous population of Fusarium circinatum causes pitch canker of Pinus radiata in the Basque Country, Spain
Pitch canker, caused by Fusarium circinatum, is a destructive disease of Pinus species and has recently been shown to represent a substantial threat to natural and commercial forests in northern Spain. The genetic diversity of F. circinatum in the Basque Country of Spain was assessed by characterising 96 isolates based on vegetative compatibility groups (VCGs), mating type assays, polymorphic DNA-markers and amplified fragment length polymorphism (AFLP) analyses. For this purpose, F. circinatum isolates were collected from diseased Pinus radiata as well as from insects associated with this host. Overall, a low level of diversity was detected in the population. The isolates represented only two VCGs and they were all of the same mating type. AFLP analyses revealed three genotypes and polymorphic DNA-markers specific for F. circinatum showed nine genotypes. The most common genotypes represented 97 % of all isolates for AFLP analysis and 68 % of isolates for the polymorphic DNA-marker sets. Over all, this indicates that pitch canker in the Basque Country of Spain is caused by a clonally propagating population of F. circinatum, typical of a recently introduced pathogen.Agriculture, Fish and Food Department of the Basque Government (Spain); Education, Universities and Research Department of the Basque Government (Spain); Forest Biosecurity Research Council (New Zealand); National Centre for Advanced Bio-Protection Technologies (New Zealand); Foundation for Research Science and Technology (New Zealand); members of Tree Protection Co-operative Programme (South Africa); National Research Foundation (South Africa); THRIP initiative of the Department of Trade and Industry (South Africa
16(th) IHIW: analysis of HLA population data, with updated results for 1996 to 2012 workshop data (AHPD project report).
International audienceWe present here the results of the Analysis of HLA Population Data (AHPD) project of the 16th International HLA and Immunogenetics Workshop (16IHIW) held in Liverpool in May-June 2012. Thanks to the collaboration of 25 laboratories from 18 different countries, HLA genotypic data for 59 new population samples (either well-defined populations or donor registry samples) were gathered and 55 were analysed statistically following HLA-NET recommendations. The new data included, among others, large sets of well-defined populations from north-east Europe and West Asia, as well as many donor registry data from European countries. The Gene[rate] computer tools were combined to create a Gene[rate] computer pipeline to automatically (i) estimate allele frequencies by an expectation-maximization algorithm accommodating ambiguities, (ii) estimate heterozygosity, (iii) test for Hardy-Weinberg equilibrium (HWE), (iv) test for selective neutrality, (v) generate frequency graphs and summary statistics for each sample at each locus and (vi) plot multidimensional scaling (MDS) analyses comparing the new samples with previous IHIW data. Intrapopulation analyses show that HWE is rarely rejected, while neutrality tests often indicate a significant excess of heterozygotes compared with neutral expectations. The comparison of the 16IHIW AHPD data with data collected during previous workshops (12th-15th) shows that geography is an excellent predictor of HLA genetic differentiations for HLA-A, -B and -DRB1 loci but not for HLA-DQ, whose patterns are probably more influenced by natural selection. In Europe, HLA genetic variation clearly follows a north to south-east axis despite a low level of differentiation between European, North African and West Asian populations. Pacific populations are genetically close to Austronesian-speaking South-East Asian and Taiwanese populations, in agreement with current theories on the peopling of Oceania. Thanks to this project, HLA genetic variation is more clearly defined worldwide and better interpreted in relation to human peopling history and HLA molecular evolution
New species of Ophiostomatales from Scolytinae and Platypodinae beetles in the Cape Floristic Region, including the discovery of the sexual state of Raffaelea
Olea capensis and Rapanea melanophloeos
are important canopy trees in South African
Afromontane forests. Dying or recently dead individuals
of these trees are often infested by Scolytinae and
Platypodinae (Curculionidae) beetles. Fungi were
isolated from the surfaces of beetles emerging from
wood samples and their galleries. Based on micromorphological
and phylogenetic analyses, four fungal
species in the Ophiostomatales were isolated. These were Sporothrix pallida and three taxa here newly
described as Sporothrix aemulophila sp. nov., Raffaelea
vaginata sp. nov. and Raffaelea rapaneae sp. nov.
This study represents the first collection of S. pallida, a
species known from many environmental samples
from across the world, from Scolytinae beetles. S.
aemulophila sp. nov. is an associate of the ambrosia
beetle Xyleborinus aemulus. R. rapaneae sp. nov. and
R. vaginata sp. nov. were associated with a Lanurgus
sp. and Platypodinae beetle, respectively, and represent
the first Raffaelea spp. reported from the Cape
Floristic Region. Of significance is that R. vaginata
produced a sexual state analogous with those of Ophiostoma seticolle and O. deltoideosporum that
also grouped in our analyses in Raffaelea s. str., to date
considered an asexual genus. The morphology of the
ossiform ascospores and anamorphs of the three
species corresponded and the generic circumscription
of Raffaelea is thus emended to accommodate sexual
states. The two known species are provided with new
combinations, namely Raffaelea seticollis (R.W.
Davidson) Z.W. de Beer and T.A. Duong comb. nov.
and Raffaelea deltoideospora (Olchow. and J. Reid)
Z.W. de Beer and T.A. Duong comb. nov.DST/NRF Centre of Excellence in Tree Health Biotechnology (CHTB).http://link.springer.com/journal/104822016-10-30hb201