8,701 research outputs found
Standardising an infant fNIRS analysis pipeline to investigate neurodevelopment in global health
Data analysis methods for infant fNIRS data in global health are not standardised yet. This work proposes an analysis pipeline that improves the quality of the recovered HRF for use by other researchers in this field
Coexistence of monopoles and instantons for different topological charge definitions and lattice actions
We compute instanton sizes and study correlation functions between instantons
and monopoles in maximum abelian projection within SU(2) lattice QCD at finite
temperature. We compare several definitions of the topological charge,
different lattice actions and methods of reducing quantum fluctuations. The
average instanton size turns out to be fm. The correlation
length between monopoles and instantons is fm and hardly
affected by lattice artifacts as dislocations. We visualize several specific
gauge field configurations and show directly that there is an enhanced
probability for finding monopole loops in the vicinity of instantons. This
feature is independent of the topological charge definition used.Comment: 10 pages, LaTeX, uses elsart.sty and elsart12.sty, 16 eps files, 4
figures, published, for corresponding movies (MPEG) see
http://www.tuwien.ac.at/e142/Lat/qcd.htm
Enhancement of radiosensitivity by the novel anticancer quinolone derivative vosaroxin in preclinical glioblastoma models
Purpose: Glioblastoma multiforme (GBM) is the most aggressive brain tumor. The activity of vosaroxin, a first-in-class anticancer quinolone derivative that intercalates DNA and inhibits topoisomerase II, was investigated in GBM preclinical models as a single agent and combined with radiotherapy (RT). Results: Vosaroxin showed antitumor activity in clonogenic survival assays, with IC50 of 10-100 nM, and demonstrated radiosensitization. Combined treatments exhibited significantly higher ÎłH2Ax levels compared with controls. In xenograft models, vosaroxin reduced tumor growth and showed enhanced activity with RT; vosaroxin/RT combined was more effective than temozolomide/RT. Vosaroxin/ RT triggered rapid and massive cell death with characteristics of necrosis. A minor proportion of treated cells underwent caspase-dependent apoptosis, in agreement with in vitro results. Vosaroxin/RT inhibited RT-induced autophagy, increasing necrosis. This was associated with increased recruitment of granulocytes, monocytes, and undifferentiated bone marrow-derived lymphoid cells. Pharmacokinetic analyses revealed adequate blood-brain penetration of vosaroxin. Vosaroxin/RT increased disease-free survival (DFS) and overall survival (OS) significantly compared with RT, vosaroxin alone, temozolomide, and temozolomide/RT in the U251-luciferase orthotopic model. Materials and Methods: Cellular, molecular, and antiproliferative effects of vosaroxin alone or combined with RT were evaluated in 13 GBM cell lines. Tumor growth delay was determined in U87MG, U251, and T98G xenograft mouse models. (DFS) and (OS) were assessed in orthotopic intrabrain models using luciferasetransfected U251 cells by bioluminescence and magnetic resonance imaging. Conclusions: Vosaroxin demonstrated significant activity in vitro and in vivo in GBM models, and showed additive/synergistic activity when combined with RT in O6- methylguanine methyltransferase-negative and -positive cell lines
Interpreting County Level COVID-19 Infection and Feature Sensitivity using Deep Learning Time Series Models
Interpretable machine learning plays a key role in healthcare because it is
challenging in understanding feature importance in deep learning model
predictions. We propose a novel framework that uses deep learning to study
feature sensitivity for model predictions. This work combines sensitivity
analysis with heterogeneous time-series deep learning model prediction, which
corresponds to the interpretations of spatio-temporal features. We forecast
county-level COVID-19 infection using the Temporal Fusion Transformer. We then
use the sensitivity analysis extending Morris Method to see how sensitive the
outputs are with respect to perturbation to our static and dynamic input
features. The significance of the work is grounded in a real-world COVID-19
infection prediction with highly non-stationary, finely granular, and
heterogeneous data. 1) Our model can capture the detailed daily changes of
temporal and spatial model behaviors and achieves high prediction performance
compared to a PyTorch baseline. 2) By analyzing the Morris sensitivity indices
and attention patterns, we decipher the meaning of feature importance with
observational population and dynamic model changes. 3) We have collected 2.5
years of socioeconomic and health features over 3142 US counties, such as
observed cases and deaths, and a number of static (age distribution, health
disparity, and industry) and dynamic features (vaccination, disease spread,
transmissible cases, and social distancing). Using the proposed framework, we
conduct extensive experiments and show our model can learn complex interactions
and perform predictions for daily infection at the county level. Being able to
model the disease infection with a hybrid prediction and description accuracy
measurement with Morris index at the county level is a central idea that sheds
light on individual feature interpretation via sensitivity analysis
Recognizing and Drawing IC-planar Graphs
IC-planar graphs are those graphs that admit a drawing where no two crossed
edges share an end-vertex and each edge is crossed at most once. They are a
proper subfamily of the 1-planar graphs. Given an embedded IC-planar graph
with vertices, we present an -time algorithm that computes a
straight-line drawing of in quadratic area, and an -time algorithm
that computes a straight-line drawing of with right-angle crossings in
exponential area. Both these area requirements are worst-case optimal. We also
show that it is NP-complete to test IC-planarity both in the general case and
in the case in which a rotation system is fixed for the input graph.
Furthermore, we describe a polynomial-time algorithm to test whether a set of
matching edges can be added to a triangulated planar graph such that the
resulting graph is IC-planar
Topology at the Deconfinement Transition Uncovered by Inverse Blocking in SU(2) Pure Gauge Theory with Fixed Point Action
Renormalization group transformations as discussed recently in deriving fixed
point actions are used to analyse the vacuum structure near to the
deconfinement temperature. Monte Carlo configurations are generated using the
fixed point action. We compare equilibrium configurations with configurations
obtained by inverse blocking from a coarser lattice. The absence of short range
vacuum fluctuations in the latter does not influence the string tension. For
the inversely blocked configurations we find the following: (i) the topological
susceptibility chi_top is consistent with the phenomenological value in the
confinement phase, (ii) chi_top drops across the deconfinement transition,
(iii) density and size of instantons are estimated, (iv) the topological
density is found to be correlated to Abelian monopole currents and (v) the
density of spacelike monopole currents becomes a confinement order parameter.Comment: Updated version to appear in Nucl. Phys.
Four-loop free energy for the 2D O(n) nonlinear sigma-model with 0-loop and 1-loop Symanzik improved actions
We calculate up to four loops the free energy of the two-dimensional (2D)
O(n) nonlinear sigma-model regularized on the lattice with the 0-loop and
1-loop Symanzik improved actions. An effective coupling constant based on this
calculation is defined.Comment: 26 pages, Revtex. More details about the calculation procedur
Phase transitions and He-synthesis driven winds in neutrino cooled accretion disks: prospects for late flares in short gamma-ray bursts
We consider the long term evolution of debris following the tidal disruption
of compact stars in the context of short gamma ray bursts (SGRBs). The initial
encounter impulsively creates a hot, dense, neutrino-cooled disk capable of
powering the prompt emission. After a long delay, we find that powerful winds
are launched from the surface of the disk, driven by the recombination of free
nucleons into alpha particles. The associated energy release depletes the mass
supply and eventually shuts off activity of the central engine. As a result,
the luminosity and mass accretion rate deviate from the earlier self-similar
behavior expected for an isolated ring with efficient cooling. This then
enables a secondary episode of delayed activity to become prominent as an
observable signature, when material in the tidal tails produced by the initial
encounter returns to the vicinity of the central object. The time scale of the
new accretion event can reach tens of seconds to minutes, depending on the
details of the system. The associated energies and time scales are consistent
with those occurring in X-ray flares.Comment: Revised version, accepted for publication in ApJ Letter
Characterization of Italian Cheeses Ripened Under Nonconventional Conditions
International audience; Four Italian cheeses (Casciotta di Urbino, Barricato San Martino, Vento d'Estate, and Ubriaco di Raboso) nonconventionally ripened under different plant materials (walnut leaves, herbs, hay, and wine by-products, respectively) were compared for compositional, microbiological, biochemical, and volatile profile characteristics. Mean values for gross composition were rather similar. Because primary starters were not used for manufacture, the endogenous lactic acid bacteria were mainly present (7.0 to 9.0 log10 cfu/g). Except for Lactobacillus paracasei and Leuconostoc mesenteroides, which were commonly identified in 3 cheeses, Lactococcus lactis, Enterococcus sanguinicola, Lactobacillus brevis, Enterococcus durans/Enterococcus faecium, Lactobacillus plantarum, and Weissella cibaria/Weissella confusa were variously found in the 4 cheeses. Random amplification of polymorphic DNA-PCR analysis showed the biodiversity among the strains, and the species of lactobacilli were in part grouped according to their origin. As shown by the principal component analysis of reverse-phase fast protein liquid chromatography data for the pH 4.6-soluble fractions and by the determination of free AA, the secondary proteolysis of Barricato San Martino and Vento d'Estate mainly differed from the other 2 cheeses. Purge-and-trap and solid-phase microextraction were coupled with gas chromatography-mass spectrometry to determine volatile compounds. Vento d'Estate showed the highest levels of almost all chemical classes, and Casciotta di Urbino was characterized by a very low level of volatile components. Esters, ketones, and terpenes were the chemical classes that mainly differentiated the cheeses. Several volatile compounds seemed to be released directly from the plant materials used for ripening, especially terpenes for Vento d'Estate cheese. The lowest level of volatile free fatty acids was found in Casciotta d'Urbino, in which rennet paste was not used during manufacture. The highest concentration of free fatty acids, especially butyric and caproic acids, was found in Vento d'Estate cheese
Topology of the SU(2) vacuum: a lattice study using improved cooling
We study the topological structure of the SU(2) vacuum at zero temperature:
topological susceptibility, size, shape and distance distributions of the
instantons. We use a cooling algorithm based on an improved action with scale
invariant instanton solutions. This algorithm needs no monitoring or
calibration, has an inherent cut off for dislocations and leaves unchanged
instantons at physical scales. The physical relevance of our results is checked
by studying the scaling and finite volume dependence. We obtain a
susceptibility of (200(15) MeV)^4. The instanton size distribution is peaked
around 0.43fm, and the distance distribution indicates a homogeneous, random
spatial structure.Comment: 45 pages, Latex, 19 figures. Improvements and some new remarks added
in sections 3.4, 3.5, 4. and figures 14, 16, 17 and 18 (concerning mostly I-A
interactions and density-density correlations). New references adde
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