1,573 research outputs found
Loopy Cuts: Surface-Field Aware Block Decomposition for Hex-Meshing.
We present a new fully automatic block-decomposition hexahedral meshing
algorithm capable of producing high quality meshes that strictly preserve
feature curve networks on the input surface and align with an input surface
cross-field. We produce all-hex meshes on the vast majority of inputs, and
introduce localized non-hex elements only when the surface feature network
necessitates those. The input to our framework is a closed surface with a
collection of geometric or user-demarcated feature curves and a feature-aligned
surface cross-field. Its output is a compact set of blocks whose edges
interpolate these features and are loosely aligned with this cross-field. We
obtain this block decomposition by cutting the input model using a collection
of simple cutting surfaces bounded by closed surface loops. The set of cutting
loops spans the input feature curves, ensuring feature preservation, and is
obtained using a field-space sampling process. The computed loops are uniformly
distributed across the surface, cross orthogonally, and are loosely aligned
with the cross-field directions, inducing the desired block decomposition. We
validate our method by applying it to a large range of complex inputs and
comparing our results to those produced by state-of-the-art alternatives.
Contrary to prior approaches, our framework consistently produces high-quality
field aligned meshes while strictly preserving geometric or user-specified
surface features
Influence of three species of arbuscular mycorrhizal fungi on the persistence of aromatic hydrocarbons in contaminated substrates
Neural bases of reward anticipation in healthy individuals with low, mid, and high levels of schizotypy
A growing body of research has placed the ventral striatum at the center of a network of cerebral regions involved in anticipating rewards in healthy controls. However, little is known about the functional connectivity of the ventral striatum associated with reward anticipation in healthy controls. In addition, few studies have investigated reward anticipation in healthy humans with different levels of schizotypy. Here, we investigated reward anticipation in eighty-four healthy individuals (44 females) recruited based on their schizotypy scores. Participants performed a variant of the Monetary Incentive Delay Task while undergoing event-related fMRI.Participants showed the expected decrease in response times for highly rewarded trials compared to non-rewarded trials. Whole-brain activation analyses replicated previous results, including activity in the ventral and dorsal striatum. Whole-brain psycho-physiological interaction analyses of the left and right ventral striatum revealed increased connectivity during reward anticipation with widespread regions in frontal, parietal and occipital cortex as well as the cerebellum and midbrain. Finally, we found no association between schizotypal personality severity and neural activity and cortico-striatal functional connectivity. In line with the motivational, attentional, and motor functions of rewards, our data reveal multifaceted cortico-striatal networks taking part in reward anticipation in healthy individuals. The ventral striatum is connected to regions of the salience, attentional, motor and visual networks during reward anticipation and thereby in a position to orchestrate optimal goal-directed behavior
Magnetic coupling to the Advanced Virgo payloads and its impact on the low frequency sensitivity
We study the electromagnetic coupling of the Advanced Virgo (AdV) Input
Mirror Payload (IMP) in response to a slowly time-varying magnetic field. As
the problem is not amenable to analytical solution, we employ and validate a
finite element (FE) analysis approach. The FE model is built to represent as
faithfully as possible the real object and it has been validated by comparison
with experimental measurements. The intent is to estimate the induced currents
and the magnetic field in the neighbourhood of the payload. The procedure found
21 equivalent electrical configurations that are compatible with the
measurements. These have been used to compute the magnetic noise contribution
to the total AdV strain noise. At the current stage of development AdV seems to
be unaffected by magnetic noise, but we foresee a non-negligible coupling once
AdV reaches the design sensitivity.Comment: 8 pages, 8 figures, 2 table
Displacement power spectrum measurement of a macroscopic optomechanical system at thermal equilibrium
The mirror relative motion of a suspended Fabry-Perot cavity is studied in
the frequency range 3-10 Hz. The experimental measurements presented in this
paper, have been performed at the Low Frequency Facility, a high finesse
optical cavity 1 cm long suspended to a mechanical seismic isolation system
identical to that one used in the VIRGO experiment. The measured relative
displacement power spectrum is compatible with a system at thermal equilibrium
within its environmental. In the frequency region above 3 Hz, where seismic
noise contamination is negligible, the measurement distribution is stationary
and Gaussian, as expected for a system at thermal equilibrium. Through a simple
mechanical model it is shown that: applying the fluctuation dissipation theorem
the measured power spectrum is reproduced below 90 Hz and noise induced by
external sources are below the measurement.Comment: 11 pages, 9 figures, 2 tables, to be submitte
H19 long noncoding RNA controls the mRNA decay promoting function of KSRP
Long noncoding RNAs (lncRNAs) interact with protein factors to regulate different layers of gene expression transcriptionally or posttranscriptionally. Here we report on the functional consequences of the unanticipated interaction of the RNA binding protein K homology-type splicing regulatory protein (KSRP) with the H19 lncRNA (H19). KSRP directly binds to H19 in the cytoplasm of undifferentiated multipotent mesenchymal C2C12 cells, and this interaction favors KSRP-mediated destabilization of labile transcripts such as myogenin. AKT activation induces KSRP dismissal from H19 and, as a consequence, myogenin mRNA is stabilized while KSRP is repurposed to promote maturation of myogenic microRNAs, thus favoring myogenic differentiation. Our data indicate that H19 operates as a molecular scaffold that facilitates effective association of KSRP with myogenin and other labile transcripts, and we propose that H19 works with KSRP to optimize an AKT-regulated posttranscriptional switch that controls myogenic differentiation
A biology-driven approach identifies the hypoxia gene signature as a predictor of the outcome of neuroblastoma patients
A biology-driven approach identifies the hypoxia gene signature as a predictor of the outcome of neuroblastoma patients
Molecular subtypes, metastatic pattern and patient age in breast cancer: An analysis of italian network of cancer registries (airtum) data
Breast cancer stage at diagnosis, patient age and molecular tumor subtype influence disease progression. The aim of this study was to analyze the relationships between these factors and survival in breast cancer patients among the Italian population using data from the AIRTUM national database. We enrolled women with primary breast cancer from 17 populationâbased cancer registries. Patients were subdivided into older (>69 years), middle (50â69 years) and younger age groups (<50 years) and their primary tumors categorized into four molecular subtypes based on hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status. There were 8831 patients diagnosed between 2010 and 2012 included. The most represented age group was 50â 69 years (41.7%). In 5735 cases the molecular subtype was identified: HER2â/HR+ was the most frequent (66.2%) and HER2+/HRâ the least (6.2%). Of the 390 women with metastases at diagnosis, 38% had simultaneous involvement of multiple sites, independent of age and molecular profile. In women with a single metastatic site, bone (20% of cases), liver (11%), lung (7%) and brain (3%) were the most frequent. In the studied age groups with different receptor expression profiles, the tumor metastasized to target organs with differing frequencies, affecting survival. Fiveâyear survival was lowest in women with tripleânegative (HER2â/HRâ) tumors and women with brain metastases at diagnosis
Changes in Dry State Hemoglobin over Time Do Not Increase the Potential for Oxidative DNA Damage in Dried Blood
BACKGROUND: Hemoglobin (Hb) is the iron-containing oxygen transport protein present in the red blood cells of vertebrates. Ancient DNA and forensic scientists are particularly interested in Hb reactions in the dry state because both regularly encounter aged, dried bloodstains. The DNA in such stains may be oxidatively damaged and, in theory, may be deteriorated by the presence of Hb. To understand the nature of the oxidative systems potentially available to degrade DNA in the presence of dried Hb, we need to determine what molecular species Hb forms over time. These species will determine what type of iron (i.e. Fe(2+)/Fe(3+)/Fe(4+)) is available to participate in further chemical reactions. The availability of "free" iron will affect the ability of the system to undergo Fenton-type reactions which generate the highly reactive hydroxyl radical (OH*). The OH* can directly damage DNA. METHODOLOGY/PRINCIPAL FINDINGS: Oxygenated Hb (oxyHb) converts over time to oxidized Hb (metHb), but this happens more quickly in the dry state than in the hydrated state, as shown by monitoring stabilized oxyHb. In addition, dry state oxyHb converts into at least one other unknown species other than metHb. Although "free" iron was detectable as both Fe(2+) and Fe(3+) in dry and hydrated oxyHb and metHb, the amount of ions detected did not increase over time. There was no evidence that Hb becomes more prone to generating OH* as it ages in either the hydrated or dry states. CONCLUSIONS: The Hb molecule in the dried state undergoes oxidative changes and releases reactive Fe(II) cations. These changes, however, do not appear to increase the ability of Hb to act as a more aggressive Fenton reagent over time. Nevertheless, the presence of Hb in the vicinity of DNA in dried bloodstains creates the opportunity for OH*-induced oxidative damage to the deoxyribose sugar and the DNA nucleobases
- âŠ