62 research outputs found
Dementia Caregiver Burden: A Research Update and Critical Analysis
Purpose of Review: This article provides an updated review of the determinants of caregiver burden and depression, with a focus on care demands and especially the differential effects of various neuropsychiatric symptoms or symptom clusters. Moreover, studies on caregivers for frontotemporal and Lewy body dementias were referred to in order to identify differences and similarities with the mainstream literature based largely on Alzheimer caregivers. Recent Findings: As a group, neuropsychiatric symptoms are most predictive of caregiver burden and depression regardless of dementia diagnosis, but the effects appear to be driven primarily by disruptive behaviors (e.g., agitation, aggression, disinhibition), followed by delusions and mood disturbance. Disruptive behaviors are more disturbing partly because of the adverse impact on the emotional connection between the caregiver and the care-recipient and partly because they exacerbate difficulties in other domains (e.g., caring for activities of daily living). In behavioral variant frontotemporal dementia, not only are these disruptive behaviors more prominent but they are also more disturbing due to the care-recipient’s insensitivity to others’ feelings. In Lewy body dementia, visual hallucinations also appear to be distressing. Summary: The disturbing nature of disruptive behaviors cuts across dementia conditions, but the roles played by symptoms that are unique or particularly serious in a certain condition need to be explored further
Potential neuroimaging biomarkers of pathologic brain changes in Mild Cognitive Impairment and Alzheimer’s disease: a systematic review
Euclid Preparation TBD. Characterization of convolutional neural networks for the identification of galaxy-galaxy strong lensing events
Forthcoming imaging surveys will potentially increase the number of known
galaxy-scale strong lenses by several orders of magnitude. For this to happen,
images of tens of millions of galaxies will have to be inspected to identify
potential candidates. In this context, deep learning techniques are
particularly suitable for the finding patterns in large data sets, and
convolutional neural networks (CNNs) in particular can efficiently process
large volumes of images. We assess and compare the performance of three network
architectures in the classification of strong lensing systems on the basis of
their morphological characteristics. We train and test our models on different
subsamples of a data set of forty thousand mock images, having characteristics
similar to those expected in the wide survey planned with the ESA mission
\Euclid, gradually including larger fractions of faint lenses. We also evaluate
the importance of adding information about the colour difference between the
lens and source galaxies by repeating the same training on single-band and
multi-band images. Our models find samples of clear lenses with
precision and completeness, without significant differences in the performance
of the three architectures. Nevertheless, when including lenses with fainter
arcs in the training set, the three models' performance deteriorates with
accuracy values of to depending on the model. Our
analysis confirms the potential of the application of CNNs to the
identification of galaxy-scale strong lenses. We suggest that specific training
with separate classes of lenses might be needed for detecting the faint lenses
since the addition of the colour information does not yield a significant
improvement in the current analysis, with the accuracy ranging from
to for the different models
Euclid preparation. XXV. The Euclid Morphology Challenge -- Towards model-fitting photometry for billions of galaxies
The ESA Euclid mission will provide high-quality imaging for about 1.5
billion galaxies. A software pipeline to automatically process and analyse such
a huge amount of data in real time is being developed by the Science Ground
Segment of the Euclid Consortium; this pipeline will include a model-fitting
algorithm, which will provide photometric and morphological estimates of
paramount importance for the core science goals of the mission and for legacy
science. The Euclid Morphology Challenge is a comparative investigation of the
performance of five model-fitting software packages on simulated Euclid data,
aimed at providing the baseline to identify the best suited algorithm to be
implemented in the pipeline. In this paper we describe the simulated data set,
and we discuss the photometry results. A companion paper (Euclid Collaboration:
Bretonni\`ere et al. 2022) is focused on the structural and morphological
estimates. We created mock Euclid images simulating five fields of view of 0.48
deg2 each in the band of the VIS instrument, each with three realisations
of galaxy profiles (single and double S\'ersic, and 'realistic' profiles
obtained with a neural network); for one of the fields in the double S\'ersic
realisation, we also simulated images for the three near-infrared ,
and bands of the NISP-P instrument, and five Rubin/LSST optical
complementary bands (, , , , and ). To analyse the results we
created diagnostic plots and defined ad-hoc metrics. Five model-fitting
software packages (DeepLeGATo, Galapagos-2, Morfometryka, ProFit, and
SourceXtractor++) were compared, all typically providing good results. (cut)Comment: 29 pages, 33 figures. Euclid pre-launch key paper. Companion paper:
Bretonniere et al. 202
Euclid preparation XXVI. The Euclid Morphology Challenge. Towards structural parameters for billions of galaxies
The various Euclid imaging surveys will become a reference for studies of
galaxy morphology by delivering imaging over an unprecedented area of 15 000
square degrees with high spatial resolution. In order to understand the
capabilities of measuring morphologies from Euclid-detected galaxies and to
help implement measurements in the pipeline, we have conducted the Euclid
Morphology Challenge, which we present in two papers. While the companion paper
by Merlin et al. focuses on the analysis of photometry, this paper assesses the
accuracy of the parametric galaxy morphology measurements in imaging predicted
from within the Euclid Wide Survey. We evaluate the performance of five
state-of-the-art surface-brightness-fitting codes DeepLeGATo, Galapagos-2,
Morfometryka, Profit and SourceXtractor++ on a sample of about 1.5 million
simulated galaxies resembling reduced observations with the Euclid VIS and NIR
instruments. The simulations include analytic S\'ersic profiles with one and
two components, as well as more realistic galaxies generated with neural
networks. We find that, despite some code-specific differences, all methods
tend to achieve reliable structural measurements (10% scatter on ideal S\'ersic
simulations) down to an apparent magnitude of about 23 in one component and 21
in two components, which correspond to a signal-to-noise ratio of approximately
1 and 5 respectively. We also show that when tested on non-analytic profiles,
the results are typically degraded by a factor of 3, driven by systematics. We
conclude that the Euclid official Data Releases will deliver robust structural
parameters for at least 400 million galaxies in the Euclid Wide Survey by the
end of the mission. We find that a key factor for explaining the different
behaviour of the codes at the faint end is the set of adopted priors for the
various structural parameters.Comment: Accepted by A&A. 30 pages, 23+6 figures, Euclid pre-launch key paper.
Companion paper: Euclid Collaboration XXV: Merlin et al. 2022 Minor
corrections after journal revie
Euclid preparation. XXVI. The Euclid Morphology Challenge: Towards structural parameters for billions of galaxies
Connecting Terminal Carboxylate Groups in Nine-Coordinate Lanthanide Podates: Consequences on the Thermodynamic, Structural, Electronic, and Photophysical Properties
Ratiometric probes for hydrogencarbonate analysis in intracellular or extracellular environments using europium luminescence
A series of six, cationic, zwitterionic and anionic Eu complexes has been examined for the analysis of hydrogencarbonate concentration in the intracellular and extracellular ranges; an anionic complex incorporating three glutarate residues and a sensitising acridone chromophore (lambda exc = 410 nm) exhibits a 69% change in the intensity ratio of the 618/588 nm Eu emission bands between 5 and 15 mM HCO3- in a cell lysate medium
Two-dimensional supramolecular assemblies involving neoglycoplipids: Self-organization and insertion properties into Langmuir monolayers.
International audienceIn nature, interfacial molecular recognition and chirality are of fundamental significance for the construction of biological assemblies. Lipid monolayers at liquid interface can be used as biomimetic models for studying molecular interactions in such assemblies. In this article, we will focus on the use of Langmuir monolayers for studying self-organization and insertion properties of several neoglycolipids. Two types of glycolipids have been considered, one in the context of the analysis of glycoconjugates of biological relevance, and one dealing with the ability of some glycoprobes to insert into a monolayer in relation with their efficiency for serving as membrane imaging systems
Relating structural and thermodynamic effects of the Pb(II) lone pair: a new picolinate ligand designed to accommodate the Pb(II) lone pair leads to high stability and selectivity
The crystal and molecular structure and the stability of lead and calcium complexes of two chelates containing picolinate chelating groups in different geometries have been investigated in order to relate the ligand affinity and selectivity for lead over calcium with the ability of the ligand to accommodate a stereochemically active lone pair. The crystal structures of the lead complexes of the diprotonated and monoprotonated tripodal ligand tpaa2- show that the three picolinate arms of the tripodal ligand coordinate the lead in an asymmetric way leaving a gap in the coordination sphere to accommodate the lead lone pair. As a consequence of this binding mode, one picolinate arm is very weakly bound and therefore can be expected to contribute very little to the complex stability. Conversely, the geometry of the dipodal ligand H2dpaea is designed to accommodate the lead lone pair; in the structure of the [Pb(dpaea)] complex the donor atoms of the ligand occupy only a quarter of the coordination sphere, reducing the sterical interaction between the lead lone pair with respect to the H3tpaa complexes. As a result, in the lead structures of H2dpaea all the ligand donor atoms are strongly bound to the metal ion leading to increased stability. The high value of the formation constant measured for the lead complex of the dipodal dpaea2- (log β11(Pb) = 12.1(3)) compared to the lower value found for the one of the tripodal tpaa3- (log β11(Pb) = 10.0(1)) provides direct evidence of the influence of the stereochemically active lead lone pair on complex stability. As a result, since the ligand geometry has little effect on the stability of the calcium complex, a remarkable increase in the Pb/Ca selectivity is observed for dpaea-(106.6) compared to tpaa3- (101.5), making the dipodal ligand a good candidate for application as extracting agent for the lead removal from contaminated water
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