772 research outputs found
Present-day vegetation and the Holocene and recent development of Egelsee-Moor, Salzburg province, Austria
This paper describes the present-day vegetation, stratigraphy and developmental history of the mire of Egelsee-Moor (Salzburg, Austria; 45°45′N, 13°8.5′E, 700 m a.s.l., 15 ha in area) since the early Late Glacial on the basis of 4 transects with 14 trial borings across the peatland. We present a vegetation map of the mire, a longitudinal section through the peat body based on six cores showing the peat types, overview macrofossil diagrams of six cores showing the local mire development and two pollen diagrams covering the Late Glacial and Holocene. The chronology of the diagrams depends on biostratigraphic dating for the Late Glacial and early Holocene and radiocarbon dating for the remaining Holocene. The northern part of the mire originated through terrestrialisation of nutrient-rich, mostly inundated fen and the southern part through paludification of wet soils. The very small lake of today was a reservoir until recently for providing water-power for timber rafting (‘Holztrift’). The mire vegetation today is a complex of forested parts (mainly planted Pinus sylvestris and Thuja occidentalis, but also spontaneous Picea abies, Betula pubescens and Frangula alnus), reed-lands (Phragmites) and litter meadows (Molinietum, Schoenetum, etc.). The central part has hummock-hollow complexes with regionally rare species of transitional mires (Drosera anglica, D. intermedia, Lycopodiella inundata, Scorpidium scorpioides, Sphagnum platyphyllum, S. subnitens). The results indicate that some of the mid-Holocene sediments may have been removed by the timber-rafting practices, and that water extraction from the hydrological catchment since 1967 has resulted in a partial shift of transitional mire to ombrotrophic bog. The latter potentially endangers the regionally rare species and was used as an argument to stop further water extraction
Emissie-beperkend spuiten in de glastuinbouw
Stand van zaken rond beperktere inzet van bestrijdingsmiddelen. Voor de kasteelt van tomaten en chrysanten
Pollen reveals the diet and environment of an extinct Pleistocene giant deer from the Netherlands
Pollen analysis of five teeth (two premolars, three molars) from a single maxilla of a giant deer (Megaloceros giganteus) found in Pleistocene deposits in The Netherlands reflects the diet and the landscape of the specimen that lived in eastern Doggerland. Apiaceae (among which Anthriscus sylvestris, Heracleum and Hydrocotyle), Asteraceae (among which Anthemis-type, Senecio-type and Cichorioideae), Filipendula, Poaceae and Symphytum were among the ingested plants. The landscape had dense, species-rich tall-herb vegetation and an open tree layer of Alnus and Betula, whereas thermophilous tree taxa were absent. Climate was probably cool-temperate, semi-dry, sub-continental. A radiocarbon date of the maxilla is beyond the 14C detection limit. We conclude that our giant deer most likely lived during the early Eemian or during an early Weichselian interstadial.</p
MRI Natural History of the Leukodystrophy Vanishing White Matter
Background: In vanishing white matter (VWM), a form of leukodystrophy, earlier onset is associated with faster clinical progression. MRI typically shows rarefaction and cystic destruction of the cerebral white matter. Information on the evolution of VWM according to age at onset is lacking. /
Purpose: To determine whether nature and progression of cerebral white matter abnormalities in VWM differ according to age at onset. /
Materials and Methods: Patients with genetically confirmed VWM were stratified into six groups according to age at onset: younger than 1 year, 1 year to younger than 2 years, 2 years to younger than 4 years, 4 years to younger than 8 years, 8 years to younger than 18 years, and 18 years or older. With institutional review board approval, all available MRI scans obtained between 1985 and 2019 were retrospectively analyzed with three methods: (a) ratio of the width of the lateral ventricles over the skull (ventricle-to-skull ratio [VSR]) was measured to estimate brain atrophy; (b) cerebral white matter was visually scored as percentage normal, hyperintense, rarefied, or cystic on fluid-attenuated inversion recovery (FLAIR) images and converted into a white matter decay score; and (c) the intracranial volume was segmented into normal-appearing white and gray matter, abnormal but structurally present (FLAIR-hyperintense) and rarefied or cystic (FLAIR-hypointense) white matter, and ventricular and extracerebral cerebrospinal fluid (CSF). Multilevel regression analyses with patient as a clustering variable were performed to account for the nested data structure. /
Results: A total of 461 examinations in 270 patients (median age, 7 years [interquartile range, 3–18 years]; 144 female patients) were evaluated; 112 patients had undergone serial imaging. Patients with later onset had higher VSR [F(5) = 8.42; P < .001] and CSF volume [F(5) = 21.7; P < .001] and lower white matter decay score [F(5) = 4.68; P < .001] and rarefied or cystic white matter volume [F(5) = 13.3; P < .001]. Rate of progression of white matter decay scores [b = –1.6, t(109) = –3.9; P < .001] and VSRs [b = –0.05, t (109) = –3.7; P < .001] were lower with later onset. /
Conclusion: A radiologic spectrum based on age at onset exists in vanishing white matter. The earlier the onset, the faster and more cystic the white matter decay, whereas with later onset, white matter atrophy and gliosis predominate
Development and bin mapping of a Rosaceae Conserved Ortholog Set (COS) of markers
12 pages, 5 tables, 6 figures, additional 3 files.Background: Detailed comparative genome analyses within the economically important Rosaceae
family have not been conducted. This is largely due to the lack of conserved gene-based molecular
markers that are transferable among the important crop genera within the family [e.g. Malus
(apple), Fragaria (strawberry), and Prunus (peach, cherry, apricot and almond)]. The lack of
molecular markers and comparative whole genome sequence analysis for this family severely
hampers crop improvement efforts as well as QTL confirmation and validation studies.
Results: We identified a set of 3,818 rosaceaous unigenes comprised of two or more ESTs that
correspond to single copy Arabidopsis genes. From this Rosaceae Conserved Orthologous Set
(RosCOS), 1039 were selected from which 857 were used for the development of intron-flanking
primers and allele amplification. This led to successful amplification and subsequent mapping of 613
RosCOS onto the Prunus TxE reference map resulting in a genome-wide coverage of 0.67 to 1.06
gene-based markers per cM per linkage group. Furthermore, the RosCOS primers showed
amplification success rates from 23 to 100% across the family indicating that a substantial part of
the RosCOS primers can be directly employed in other less studied rosaceaous crops.
Comparisons of the genetic map positions of the RosCOS with the physical locations of the
orthologs in the Populus trichocarpa genome identified regions of colinearity between the genomes
of Prunus-Rosaceae and Populus-Salicaceae.
Conclusion: Conserved orthologous genes are extremely useful for the analysis of genome
evolution among closely and distantly related species. The results presented in this study
demonstrate the considerable potential of the mapped Prunus RosCOS for genome-wide marker
employment and comparative whole genome studies within the Rosaceae family. Moreover, these
markers will also function as useful anchor points for the genome sequencing efforts currently
ongoing in this family as well as for comparative QTL analyses.This work is supported by USDA-NRI grants 2008-02259 and 2005-00743.
AC was also supported by funds from the Department of Horticulture and
Crop Science, The Ohio State University.Peer reviewe
The need for aquatic tracking networks: the permanent Belgian Acoustic Receiver Network
Aquatic biotelemetry techniques have proven to be valuable tools to generate knowledge on species behaviour, gather oceanographic data and help in assessing effects from anthropogenic disturbances. These data types support international policies and directives, needed for species and habitat conservation. As aquatic systems are highly interconnected and cross administrative borders, optimal data gathering should be organized on a large scale. This need triggered the development of regional, national and international aquatic animal tracking network initiatives around the globe. In Belgium, a national acoustic receiver network for fish tracking, called the Permanent Belgian Acoustic Receiver Network, was set up in 2014 with different research institutes collaborating. It is a permanent network with 160 acoustic receivers and since the start, over 800 animals from 16 different fish species have been tagged and generated more than 17 million detections so far. To handle all the (meta)data generated, a data management platform was built. The central database stores all the data and has an interactive web interface that allows the users to upload, manage and explore (meta)data. In addition, the database is linked to an R-shiny application to allow the user to visualize and download the detection data. The permanent tracking network is not only a collaborative platform for exchange of data, analysis tools, devices and knowledge. It also creates opportunities to perform feasibility studies and Ph.D. studies in a cost-efficient way. The Belgian tracking network is a first step towards a Pan-European aquatic tracking network
hypomyelination and congenital cataract neuroimaging features of a novel inherited white matter disorder
BACKGROUND AND PURPOSE: Hypomyelination and congenital cataract (HCC) is an autosomal recessive white matter disease caused by deficiency of hyccin, a membrane protein implicated in both central and peripheral myelination. We aimed to describe the neuroimaging features of this novel entity. MATERIALS AND METHODS: A systematic analysis of patients with unclassified leukoencephalopathies admitted to our institutions revealed 10 children with congenital cataract, slowly progressive neurologic impairment, and diffuse white matter abnormalities on neuroimaging. Psychomotor developmental delay was evident after the first year of life. Peripheral neuropathy was demonstrated by neurophysiologic studies in 9 children. The available neuroimaging studies were retrospectively reviewed. RESULTS: In all patients, neuroimaging revealed diffuse involvement of the supratentorial white matter associated with preservation of both cortical and deep gray matter structures. Supratentorial white matter hypomyelination was detected in all patients; 7 patients also had evidence of variably extensive areas of increased white matter water content. Deep cerebellar white matter hypomyelination was found in 6 patients. Older patients had evidence of white matter bulk loss and gliosis. Proton MR spectroscopy showed variable findings, depending on the stage of the disease. Sural nerve biopsy revealed hypomyelinated nerve fibers. Mutations in the DRCTNNB1A gene on chromosome 7p15.3, causing complete or severe deficiency of hyccin, were demonstrated in all patients. CONCLUSIONS: HCC is characterized by a combined pattern of primary myelin deficiency and secondary neurodegenerative changes. In the proper clinical setting, recognition of suggestive neuroimaging findings should prompt appropriate genetic investigations
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