Hidden deep in the halo: Selection of a reduced proper motion halo catalogue and mining retrograde streams in the velocity space

The Milky Way halo is one of the few galactic haloes that provides a unique insight into galaxy formation by resolved stellar populations. Here, we present a catalogue of $\sim$47 million halo stars selected independent of parallax and line-of-sight velocities, using a combination of Gaia DR3 proper motion and photometry by means of their reduced proper motion. We select high tangential velocity (halo) main sequence stars and fit distances to them using their simple colour-absolute-magnitude relation. This sample reaches out to $\sim$21 kpc with a median distance of $6.6$ kpc thereby probing much further out than would be possible using reliable Gaia parallaxes. The typical uncertainty in their distances is $0.57_{-0.26}^{+0.56}$ kpc. Using the colour range $0.45<(G_0-G_\mathrm{RP,0})<0.715$ where the main sequence is narrower, gives an even better accuracy down to $0.39_{-0.12}^{+0.18}$ kpc in distance. The median velocity uncertainty for stars within this colour range is 15.5 km/s. The distribution of these sources in the sky, together with their tangential component velocities, are very well-suited to study retrograde substructures. We explore the selection of two complex retrograde streams: GD-1 and Jhelum. For these streams, we resolve the gaps, wiggles and density breaks reported in the literature more clearly. We also illustrate the effect of the kinematic selection bias towards high proper motion stars and incompleteness at larger distances due to Gaia's scanning law. These examples showcase how the full RPM catalogue made available here can help us paint a more detailed picture of the build-up of the Milky Way halo.Comment: 17 pages. Accepted for publication in MNRAS. The catalogue has been submitted as supplementary material to CDS and MNRAS for use to do more wonderful science. Comments are welcomed and appreciated

Herstelmaatregelen in heideterreinen; invloed op de fauna

Aanleiding voor deze publicatie zijn de resultaten van het onderzoek naar de effecten van herstelmaatregelen op dieren van het heidelandschap. De afgelopen jaren werd steeds duidelijker dat het onderzoek en de toepassing daarvan moeten worden opgeschaald naar het niveau van het landschap. Dat is ook hier zichtbaar geworden: het gaat niet alleen over de droge en de natte heide, maar ook over vennen en over struwelen en bosranden. Kortom: het gaat over het complete heidelandschap, met al zijn variatie en (geleidelijke of abrupte) overgangen. En juist bij zo’n divers en samenhangend landschap is de fauna gebaa

A European reference collection of rose varieties : final report

An integrated pilot database was constructed containing administrative, morphological and molecular data as well as pictures of each variety. In spite of some encountered difficulties, it was demonstrated that two laboratories can produce substantially equivalent data and that the molecular data produced is useful as a tool for managing reference collections, prescreening and quality assuranc

On-chip interrogator based on Fourier Transform spectroscopy

In this paper, the design and the characterization of a novel interrogator based on integrated Fourier transform (FT) spectroscopy is presented. To the best of our knowledge, this is the first integrated FT spectrometer used for the interrogation of photonic sensors. It consists of a planar spatial heterodyne spectrometer, which is implemented using an array of Mach-Zehnder interferometers (MZIs) with different optical path differences. Each MZI employs a 3$\times$3 multi-mode interferometer, allowing the retrieval of the complex Fourier coefficients. We derive a system of non-linear equations whose solution, which is obtained numerically from Newton's method, gives the modulation of the sensor's resonances as a function of time. By taking one of the sensors as a reference, to which no external excitation is applied and its temperature is kept constant, about 92$\%$ of the thermal induced phase drift of the integrated MZIs has been compensated. The minimum modulation amplitude that is obtained experimentally is 400 fm, which is more than two orders of magnitude smaller than the FT spectrometer resolution.Comment: 15 pages, 6 figure

A molecular dynamics simulation of polymer crystallization from oriented amorphous state

Molecular process of crystallization from an oriented amorphous state was reproduced by molecular dynamics simulation for a realistic polyethylene model. Initial oriented amorphous state was obtained by uniaxial drawing an isotropic glassy state at 100 K. By the temperature jump from 100 K to 330 K, there occurred the crystallization into the fiber structure, during the process of which we observed the developments of various order parameters. The real space image and its Fourier transform revealed that a hexagonally ordered domain was initially formed, and then highly ordered crystalline state with stacked lamellae developed after further adjustment of the relative heights of the chains along their axes.Comment: 4 pages, 3 figure

QualitySNPng: a user-friendly SNP detection and visualization tool

QualitySNPng is a new software tool for the detection and interactive visualization of single-nucleotide polymorphisms (SNPs). It uses a haplotype-based strategy to identify reliable SNPs; it is optimized for the analysis of current RNA-seq data; but it can also be used on genomic DNA sequences derived from next-generation sequencing experiments. QualitySNPng does not require a sequenced reference genome and delivers reliable SNPs for di- as well as polyploid species. The tool features a user-friendly interface, multiple filtering options to handle typical sequencing errors, support for SAM and ACE files and interactive visualization. QualitySNPng produces high-quality SNP information that can be used directly in genotyping by sequencing approaches for application in QTL and genome-wide association mapping as well as to populate SNP arrays. The software can be used as a stand-alone application with a graphical user interface or as part of a pipeline system like Galaxy. Versions for Windows, Mac OS X and Linux, as well as the source code, are available fro

Genotype calling in tetraploid species from bi-allelic marker data using mixture models

<p>Abstract</p> <p>Background</p> <p>Automated genotype calling in tetraploid species was until recently not possible, which hampered genetic analysis. Modern genotyping assays often produce two signals, one for each allele of a bi-allelic marker. While ample software is available to obtain genotypes (homozygous for either allele, or heterozygous) for diploid species from these signals, such software is not available for tetraploid species which may be scored as five alternative genotypes (aaaa, baaa, bbaa, bbba and bbbb; nulliplex to quadruplex).</p> <p>Results</p> <p>We present a novel algorithm, implemented in the R package fitTetra, to assign genotypes for bi-allelic markers to tetraploid samples from genotyping assays that produce intensity signals for both alleles. The algorithm is based on the fitting of several mixture models with five components, one for each of the five possible genotypes. The models have different numbers of parameters specifying the relation between the five component means, and some of them impose a constraint on the mixing proportions to conform to Hardy-Weinberg equilibrium (HWE) ratios. The software rejects markers that do not allow a reliable genotyping for the majority of the samples, and it assigns a missing score to samples that cannot be scored into one of the five possible genotypes with sufficient confidence.</p> <p>Conclusions</p> <p>We have validated the software with data of a collection of 224 potato varieties assayed with an Illumina GoldenGate™ 384 SNP array and shown that all SNPs with informative ratio distributions are fitted. Almost all fitted models appear to be correct based on visual inspection and comparison with diploid samples. When the collection of potato varieties is analyzed as if it were a population, almost all markers seem to be in Hardy-Weinberg equilibrium. The R package fitTetra is freely available under the GNU Public License from <url>http://www.plantbreeding.wur.nl/UK/software_fitTetra.html</url> and as Additional files with this article.</p

Evaluatie van zeven jaar runderbegrazing in duinvalleien op Vlieland

We evaluated seven years of light cattle grazing of dune valleys (Frisian island of Vlieland) as to management objectives and effects on vegetation, flora and fauna. We compared vegetation, flora and fauna from 1993 and 2000 in a BACI-design of 14 grazed and 14 ungrazed plots, of which 20 were randomly selected from the stratum `grass overgrown moist dune valleys', and 8 from `intact Empetrum vegetations. Development towards shrubland and woodland is tempered as a consequence of cattle browsing of twigs and leaves of Prunus avium, and Betula pubescens, which reduces height and the growth form of these species. Browsing of P. avium is surprising as this is expected to occur only under shortage of other food plants. The number of seedlings under 0.5 mheight, however, increased, even in the grazed plots. Cattle form bare patches and trails in the dense and high field layers of Calamagrostis epigejos, and Carex arenaria. Vegetation height of the `overgrown valleys' increases significantly in the ungrazed plots, whereas it increases (very) lightly in the grazed plots. Numbers of plant and invertebrate species increase, which could be related to a general change to moist conditions. Grazing has neutral to light positive effects on bio-diversity, even inthe invertebrates the species number of which mostly decrease under heavier grazing pressures

Global-change effects on early-stage decomposition processes in tidal wetlands – implications from a global survey using standardized litter

Tidal wetlands, such as tidal marshes and mangroves, are hotspots for carbon sequestration. The preservation of organic matter (OM) is a critical process by which tidal wetlands exert influence over the global carbon cycle and at the same time gain elevation to keep pace with sea-level rise (SLR). The present study assessed the effects of temperature and relative sea level on the decomposition rate and stabilization of OM in tidal wetlands worldwide, utilizing commercially available standardized litter. While effects on decomposition rate per se were minor, we show strong negative effects of temperature and relative sea level on stabilization, as based on the fraction of labile, rapidly hydrolyzable OM that becomes stabilized during deployment. Across study sites, OM stabilization was 29 % lower in low, more frequently flooded vs. high, less frequently flooded zones. Stabilization declined by ∼ 75 % over the studied temperature gradient from 10.9 to 28.5 ∘C. Additionally, data from the Plum Island long-term ecological research site in Massachusetts, USA, show a pronounced reduction in OM stabilization by > 70 % in response to simulated coastal eutrophication, confirming the potentially high sensitivity of OM stabilization to global change. We therefore provide evidence that rising temperature, accelerated SLR, and coastal eutrophication may decrease the future capacity of tidal wetlands to sequester carbon by affecting the initial transformations of recent OM inputs to soil OM

Vooronderzoek Wierdense Veld : Eindrapportage mei 2005

In dit eindrapport van het vooronderzoek Wierdense Veld worden eerst de belangrijkste resultaten van de afzonderlijke onderdelen besproken (Hoofdstuk 2 tot en met 6). In hoofdstuk 2 komt de regionaal-hydrologische situatie van het Wierdense Veld aan de orde en in hoofdstuk 3 de interne hydrologie van het Wierdense Veld. Het hydrochemisch onderzoek staat beschreven in hoofdstuk 4 en de vegetatiekarterting in hoofdstuk 5. De watermacrofauna komt aan de orde in hoofdstuk 6. Hoofdstuk 7 bevat de aanbevelingen voor herstelmaatregelen en een voorstel voor de monitoring van de maatregelen staat beschreven in hoofdstuk 8