760 research outputs found
DIAGNOSIS OF ENDOCRINE DISEASE: Steroid Hormone Analysis in Diagnosis and Treatment of DSD Position Paper of EU COST Action BM 1303 "DSDnet".
Disorders or differences in sex development (DSD) comprise a heterogeneous group of conditions with an atypical sex development. For optimal diagnosis highly specialized laboratory analyses are required across European countries. Working group 3 of EU COST (European Cooperation in Science and Technology) Action BM 1303 "DSDnet" "Harmonisation of Laboratory Assessment" has developed recommendations on laboratory assessment for DSD regarding the use of technologies and analytes to be investigated. This position paper on steroid hormone analysis in diagnosis and treatment of DSD was compiled by a group of specialists in DSD and/or hormonal analysis, either from participating European Countries or international partner countries. The topics discussed comprised analytical methods (immunoassay/mass spectrometry based methods), matrices (urine/serum/saliva) and harmonisation of laboratory tests. The following positions were agreed upon: Support of the appropriate use of immunoassay and mass spectrometry based methods for diagnosis and monitoring of DSD. Serum/plasma and urine are established matrices for analysis. Laboratories performing analyses for DSD need to operate within a quality framework and actively engage in harmonisation processes so that results and their interpretation are the same irrespective of the laboratory they are performed in. Participation in activities of peer comparison such as sample exchange or when available subscribing to a relevant external quality assurance program should be achieved. The ultimate aim of the guidelines is the implementation of clinical standards for diagnosis and appropriate treatment of DSD to achieve the best outcome for patients, no matter where patients are investigated or managed
Fluctuations of water near extended hydrophobic and hydrophilic surfaces
We use molecular dynamics simulations of the SPC-E model of liquid water to
derive probability distributions for water density fluctuations in probe
volumes of different shapes and sizes, both in the bulk as well as near
hydrophobic and hydrophilic surfaces. To obtain our results, we introduce a
biased sampling of coarse-grained densities, which in turn biases the actual
solvent density. The technique is easily combined with molecular dynamics
integration algorithms. Our principal result is that the probability for
density fluctuations of water near a hydrophobic surface, with or without
surface-water attractions, is akin to density fluctuations at the water-vapor
interface. Specifically, the probability of density depletion near the surface
is significantly larger than that in bulk. In contrast, we find that the
statistics of water density fluctuations near a model hydrophilic surface are
similar to that in the bulk
Sampling and contaminant monitoring protocol for raptors
In May 2013 representatives from six countries gathered in Murcia, Spain, to attend the Workshop on “Setting best practices on raptor contaminant monitoring activities in Europe” funded by EURAPMON. The workshop developed a rough draft of the current protocol. The protocol was subsequently completed with the involvement of investigators from Belgium, Denmark, France, Germany, The Netherlands, Norway, Spain, Sweden and the United Kingdom. All contributors are experts in monitoring contaminants in raptors.
The aim of this sampling protocol is to provide guidance on types of best practice that will facilitate harmonisation of procedures between existing and emerging schemes and so maximise the reliability, comparability and interoperability of data.The methods here do not require use of anaesthesia on birds. This protocol covers the sampling of blood and feathers from live birds, addled and deserted eggs, internal organs and tissues from dead specimens, and other samples such as faeces, preen oil and pellets.</p
SSPMJ1102-3431 brown dwarf characterization from accurate proper motion and trigonometric parallax
In 2005, Scholz and collaborators (Scholz et al. 2005) discovered, in a
proper motion survey, a young brown dwarf SSSPMJ1102-3431(SSSPMJ1102) of
spectral type M8.5, probable member of the TW Hydrae Association (TWA) and
possible companion of the T Tauri star TW Hya. The physical characterization of
SSSPMJ1102 was based on the hypothesis that it forms a binary system with TW
Hya. The recent discovery of a probable giant planet inside the TW Hya
protoplanetary disk with a very short-period (Setiawan et al. 2008) and a disk
around SSSPMJ1102 (Riaz and Gizis 2008) make it especially interesting and
important to measure well the physical parameters of SSSPMJ1102. Trigonometric
parallax and proper motion measurements of SSSPMJ1102 are necessary to test for
TWA membership and, thus, to determine the mass and age of this young brown
dwarf and the possibility that it forms a wide binary system with TW Hya. Two
years of regular observations at the ESO NTT/SUSI2 telescope, have enabled us
to determine the trigonometric parallax and proper motion of SSSPMJ1102. Our
parallax and proper motion determination allow us to precisely describe the
physical properties of this low mass object and to confirm its TWA membership.
Our results are not incompatible with the hypothesis that SSSPMJ1102 is a
binary companion of the star TW Hya.Comment: accepted for publication in A&
Gaia Gral: Gaia Dr2 Gravitational Lens Systems. Vi. Spectroscopic Confirmation And Modeling Of Quadruply Imaged Lensed Quasars
Combining the exquisite angular resolution of Gaia with optical light curves and WISE photometry, the Gaia Gravitational Lenses group (GraL) uses machine-learning techniques to identify candidate strongly lensed quasars, and has confirmed over two dozen new strongly lensed quasars from the Gaia Data Release 2. This paper reports on the 12 quadruply imaged quasars identified by this effort to date, which is a similar to 20% increase in the total number of confirmed quadruply imaged quasars. We discuss the candidate selection, spectroscopic follow-up, and lens modeling. We also report our spectroscopic failures as an aid for future investigations
Visual cavity analysis in molecular simulations
Molecular surfaces provide a useful mean for analyzing interactions between biomolecules; such as identification and characterization of ligand binding sites to a host macromolecule. We present a novel technique, which extracts potential binding sites, represented by cavities, and characterize them by 3D graphs and by amino acids. The binding sites are extracted using an implicit function sampling and graph algorithms. We propose an advanced cavity exploration technique based on the graph parameters and associated amino acids. Additionally, we interactively visualize the graphs in the context of the molecular surface. We apply our method to the analysis of MD simulations of Proteinase 3, where we verify the previously described cavities and suggest a new potential cavity to be studied
Адаптация гидравлической модели водостока к бассейнам рек Дунай и Днестр
Гидравлическая модель водостока адаптирована к бассейну рек Дунай и Днестр. По данным орографии, атмосферных осадках или поверхностном стоке она позволяет рассчитывать объемы, расходы и уровни воды с пространственным разрешением 1 км. В модели возможно использование данные об экосистемах на земной поверхности, типах почвы. По данным наблюдений стока оценены среднемесячные величины расходов рек, которые соответствуют наблюдениям, что позволяет применять модель в дальнейших оценках стока, наносов и т.д.Hydraulic model of water inflow is adapted to the Danube and the Dniester rivers basin. According to the orography, precipitation and surface inflow data it permits to calculate water volumes, discharges and levels with spatial resolution 1 km. It is possible to use the data on ecosystems on the ground surface, types of soil in the model. According to the observations data of the inflow the average monthly values of river discharges corresponding to the observations are estimated. It permits to apply the model in the further estimations of inflow, alluvia e t.c
<i>Gaia</i> Data Release 1. Summary of the astrometric, photometric, and survey properties
Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7.
Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release.
Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue.
Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues – a realisation of the Tycho-Gaia Astrometric Solution (TGAS) – and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ∼3000 Cepheid and RR-Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr−1 for the proper motions. A systematic component of ∼0.3 mas should be added to the parallax uncertainties. For the subset of ∼94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr−1. For the secondary astrometric data set, the typical uncertainty of the positions is ∼10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ∼0.03 mag over the magnitude range 5 to 20.7.
Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data
Role of water in Protein Aggregation and Amyloid Polymorphism
A variety of neurodegenerative diseases are associated with the formation of
amyloid plaques. Our incomplete understanding of this process underscores the
need to decipher the principles governing protein aggregation. Most
experimental and simulation studies have been interpreted largely from the
perspective of proteins: the role of solvent has been relatively overlooked.
In this Account, we provide a perspective on how interactions with water
affect folding landscapes of A monomers, A oligomer
formation, and protofilament formation in a Sup35 peptide. Simulations show
that the formation of aggregation-prone structures (N) similar to the
structure in the fibril requires overcoming high desolvation barrier. The
mechanism of protofilament formation in a polar Sup35 peptide fragment
illustrates that water dramatically slows down self-assembly. Release of water
trapped in the pores as water wires creates protofilament with a dry interface.
Similarly, one of the main driving force for addition of a solvated monomer to
a preformed fibril is the entropy gain of released water.
We conclude by postulating that two-step model for protein crystallization
must also hold for higher order amyloid structure formation starting from
N. Multiple N structures with varying water content results in a number
of distinct water-laden polymorphic structures. In predominantly hydrophobic
sequences, water accelerates fibril formation. In contrast, water-stabilized
metastable intermediates dramatically slow down fibril growth rates in
hydrophilic sequences.Comment: 27 pages, 4 figures; Accounts of Chemical Research, 201
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