311 research outputs found
In silico synchronization reveals regulators of nuclear ruptures in lamin A/C deficient model cells
The nuclear lamina is a critical regulator of nuclear structure and function. Nuclei from laminopathy patient cells experience repetitive disruptions of the nuclear envelope, causing transient intermingling of nuclear and cytoplasmic components. The exact causes and consequences of these events are not fully understood, but their stochastic occurrence complicates in-depth analyses. To resolve this, we have established a method that enables quantitative investigation of spontaneous nuclear ruptures, based on co-expression of a rmly bound nuclear reference marker and a uorescent protein that shuttles between the nucleus and cytoplasm during ruptures. Minimally invasive imaging of both reporters, combined with automated tracking and in silico synchronization of individual rupture events, allowed extracting information on rupture frequency and recovery kinetics. Using this approach, we found that rupture frequency correlates inversely with lamin A/C levels, and can be reduced in genome- edited LMNA knockout cells by blocking actomyosin contractility or inhibiting the acetyl-transferase protein NAT10. Nuclear signal recovery followed a kinetic that is co-determined by the severity of the rupture event, and could be prolonged by knockdown of the ESCRT-III complex component CHMP4B.
In conclusion, our approach reveals regulators of nuclear rupture induction and repair, which may have critical roles in disease development
Index
Transgenic APP23 mice were generated to model Alzheimer's disease. The APP23 model develops pathological features, learning deficits, and memory deficits analogous to dementing patients. In this report, transgenic mice exhibited several behavioral disturbances indicating the presence of neuropsychiatric symptoms of dementia. Aiming to verify whether the model also develops other behavioral problems, the authors investigated ingestive behavior in APP23 males of 3, 6 and 12 months. In addition, body weights of a naive male group were longitudinally monitored starting at weaning. Olfactory acuity was evaluated in mice of different age groups. Although olfactory functioning of APP23 mice appeared intact, they drank more and took more food pellets compared with wild-type littermates during a 1-week registration period. From the age of 4.5 weeks onward, APP23 males weighed significantly less than their control littermates, whereas this difference became more prominent with increasing age. Our results suggest the presence of a hypermetabolic state in this model. This is the first report, evidencing the presence of changes in eating and drinking behavior in a single transgenic Alzheimer mouse model.status: publishe
The variable mass loss of the AGB star WX Psc as traced by the CO J=1-0 through 7-6 lines and the dust emission
Low and intermediate mass stars lose a significant fraction of their mass
through a dust-driven wind during the Asymptotic Giant Branch (AGB) phase.
Recent studies show that winds from late-type stars are far from being smooth.
Mass-loss variations occur on different time scales, from years to tens of
thousands of years. The variations appear to be particularly prominent towards
the end of the AGB evolution. The occurrence, amplitude and time scale of these
variations are still not well understood.
The goal of our study is to gain insight into the structure of the
circumstellar envelope (CSE) of WX Psc and map the possible variability of the
late-AGB mass-loss phenomenon.
We have performed an in-depth analysis of the extreme infrared AGB star WX
Psc by modeling (1) the CO J=1-0 through 7-6 rotational line profiles and the
full spectral energy distribution (SED) ranging from 0.7 to 1300 micron. We
hence are able to trace a geometrically extended region of the CSE.
Both mass-loss diagnostics bear evidence of the occurrence of mass-loss
modulations during the last ~2000 yr. In particular, WX Psc went through a high
mass-loss phase (Mdot~5e-5 Msun/yr) some 800 yr ago. This phase lasted about
600 yr and was followed by a long period of low mass loss (Mdot~5e-8 Msun/yr).
The present day mass-loss rate is estimated to be ~6e-6 Msun/yr.
The AGB star WX Psc has undergone strong mass-loss rate variability on a time
scale of several hundred years during the last few thousand years. These
variations are traced in the strength and profile of the CO rotational lines
and in the SED. We have consistently simulated the behaviour of both tracers
using radiative transfer codes that allow for non-constant mass-loss rates.Comment: 12 pages, accepted for publication in A&
European regulatory agenices should employ full time statisticians
No abstract available
Testing for Spatial Neglect with Line Bisection and Target Cancellation: Are Both Tasks Really Unrelated?
Damage to the parietal lobe can induce a condition known as spatial neglect, characterized by a lack of awareness of the personal and/or extrapersonal space opposite the damaged brain region. Spatial neglect is commonly assessed clinically using either the line bisection or the target cancellation task. However, it is unclear whether poor performance on each of these two tasks is associated with the same or different lesion locations. To date, methodological limitations and differences have prevented a definitive link between task performance and lesion location to be made. Here we report findings from a voxel-based lesion symptom mapping (VLSM) analysis of an unbiased selection of 44 patients with a recent unifocal stroke. Patients performed both the line bisection and target cancellation task. For each of the two tasks a continuous score was incorporated into the VLSM analysis. Both tasks correlated highly with each other (r = .76) and VLSM analyses indicated that the angular gyrus was the critical lesion site for both tasks. The results suggest that both tasks probe the same underlying cortical deficits and although the cancellation task was more sensitive than the line bisection task, both can be used in a clinical setting to test for spatial neglect
Using Latent Profile Analysis to Understand Health Practitioners’ Attitudes Toward Voluntary Assisted Dying
Prior work has documented considerable diversity among health practitioners regarding their support for voluntary assisted dying (VAD). We examined whether their attitudes are characterised by different combinations of personal support, normative support by other health practitioners, and whether they are predisposed to vicariously experience others’ emotions (i.e., empathy). We also examined whether these profiles experienced different mental health outcomes (i.e., burnout and posttraumatic stress) in relation to VAD. To test this, 104 Australian health practitioners were surveyed after VAD was legalised in Victoria, Australia in 2019. Results indicated that practitioners’ attitudes were characterised by three profiles: 1) strong personal and normative support (strong VAD supporters), 2) moderate personal and normative support (moderate VAD supporters), and 3) lower personal and normative support (apprehensive practitioners). However, each profile reported similar mental health outcomes. Findings suggest that the normative environments in which health practitioners operate may explain their diverse attitudes on VAD
Using Latent Profile Analysis to Understand Health Practitioners’ Attitudes Toward Voluntary Assisted Dying
Prior work has documented considerable diversity among health practitioners regarding their support for voluntary assisted dying (VAD). We examined whether their attitudes are characterised by different combinations of personal support, normative support by other health practitioners, and whether they are predisposed to vicariously experience others’ emotions (i.e., empathy). We also examined whether these profiles experienced different mental health outcomes (i.e., burnout and posttraumatic stress) in relation to VAD. To test this, 104 Australian health practitioners were surveyed after VAD was legalised in Victoria, Australia in 2019. Results indicated that practitioners’ attitudes were characterised by three profiles: 1) strong personal and normative support (strong VAD supporters), 2) moderate personal and normative support (moderate VAD supporters), and 3) lower personal and normative support (apprehensive practitioners). However, each profile reported similar mental health outcomes. Findings suggest that the normative environments in which health practitioners operate may explain their diverse attitudes on VAD
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