79 research outputs found
Threonine 149 Phosphorylation Enhances  ÎFosB Transcriptional Activity to Control Psychomotor Responses to Cocaine
Stable changes in neuronal gene expression have been studied as mediators of addicted states. Of particular interest is the transcription factor ÎFosB, a truncated and stable FosB gene product whose expression in nucleus accumbens (NAc), a key reward region, is induced by chronic exposure to virtually all drugs of abuse and regulates their psychomotor and rewarding effects. Phosphorylation at Ser[superscript 27] contributes to ÎFosB's stability and accumulation following repeated exposure to drugs, and our recent work demonstrates that the protein kinase CaMKIIα phosphorylates ÎFosB at Ser[superscript 27] and regulates its stability in vivo. Here, we identify two additional sites on ÎFosB that are phosphorylated in vitro by CaMKIIα, Thr[superscript 149] and Thr[superscript 180], and demonstrate their regulation in vivo by chronic cocaine. We show that phosphomimetic mutation of Thr[superscript 149] (T149D) dramatically increases AP-1 transcriptional activity while alanine mutation does not affect transcriptional activity when compared with wild-type (WT) ÎFosB. Using in vivo viral-mediated gene transfer of ÎFosB-T149D or ÎFosB-T149A in mouse NAc, we determined that overexpression of ÎFosB-T149D in NAc leads to greater locomotor activity in response to an initial low dose of cocaine than does WT ÎFosB, while overexpression of ÎFosB-T149A does not produce the psychomotor sensitization to chronic low-dose cocaine seen after overexpression of WT ÎFosB and abrogates the sensitization seen in control animals at higher cocaine doses. We further demonstrate that mutation of Thr[superscript 149] does not affect the stability of ÎFosB overexpressed in mouse NAc, suggesting that the behavioral effects of these mutations are driven by their altered transcriptional properties
Chemotaxis When Bacteria Remember: Drift versus Diffusion
{\sl Escherichia coli} ({\sl E. coli}) bacteria govern their trajectories by
switching between running and tumbling modes as a function of the nutrient
concentration they experienced in the past. At short time one observes a drift
of the bacterial population, while at long time one observes accumulation in
high-nutrient regions. Recent work has viewed chemotaxis as a compromise
between drift toward favorable regions and accumulation in favorable regions. A
number of earlier studies assume that a bacterium resets its memory at tumbles
-- a fact not borne out by experiment -- and make use of approximate
coarse-grained descriptions. Here, we revisit the problem of chemotaxis without
resorting to any memory resets. We find that when bacteria respond to the
environment in a non-adaptive manner, chemotaxis is generally dominated by
diffusion, whereas when bacteria respond in an adaptive manner, chemotaxis is
dominated by a bias in the motion. In the adaptive case, favorable drift occurs
together with favorable accumulation. We derive our results from detailed
simulations and a variety of analytical arguments. In particular, we introduce
a new coarse-grained description of chemotaxis as biased diffusion, and we
discuss the way it departs from older coarse-grained descriptions.Comment: Revised version, journal reference adde
Long-Term Assessment of the Effects of COVID-19 and Isolation Care on Survivor Disability and Anxiety
We conducted an assessment of disability, anxiety, and other life impacts of COVID-19 and isolation care in a unique cohort of individuals. These included both community admissions to a university hospital as well as some of the earliest international aeromedical evacuees. Among an initial 16 COVID-19 survivors that were interviewed 6-12 months following their admission into isolation care, perception of their isolation care experience was related to their reporting of long-term consequences. However, anxiety and disability assessed with standard scores had no relationship with each other. Both capture of the isolation care experience and caution relying on single scoring systems for assessing long-term consequences in survivors are important considerations for on-going and future COVID-19 and other pandemic survivor research
Precision Electron-Beam Polarimetry using Compton Scattering at 1 GeV
We report on the highest precision yet achieved in the measurement of the
polarization of a low energy, (1 GeV), electron beam, accomplished
using a new polarimeter based on electron-photon scattering, in Hall~C at
Jefferson Lab. A number of technical innovations were necessary, including a
novel method for precise control of the laser polarization in a cavity and a
novel diamond micro-strip detector which was able to capture most of the
spectrum of scattered electrons. The data analysis technique exploited track
finding, the high granularity of the detector and its large acceptance. The
polarization of the A, ~GeV electron beam was measured with a
statistical precision of ~1\% per hour and a systematic uncertainty of
0.59\%. This exceeds the level of precision required by the \qweak experiment,
a measurement of the vector weak charge of the proton. Proposed future
low-energy experiments require polarization uncertainty ~0.4\%, and this
result represents an important demonstration of that possibility. This
measurement is also the first use of diamond detectors for particle tracking in
an experiment.Comment: 9 pages, 7 figures, published in PR
Datasets for the Reporting of Primary Tumour in Bone: Recommendations From the International Collaboration on Cancer Reporting (ICCR)
BACKGROUND AND OBJECTIVES: Bone tumours are relatively rare and, as a consequence, treatment in a centre with expertise is required. Current treatment guidelines also recommend review by a specialised pathologist. Here we report on international consensus-based datasets for the pathology reporting of biopsy and resection specimens of bone sarcomas. The datasets were produced under the auspices of the International Collaboration on Cancer Reporting (ICCR), a global alliance of major (inter-)national pathology and cancer organisations.
METHODS AND RESULTS: According to the ICCR\u27s process for dataset development, an international expert panel consisting of pathologists, an oncologic orthopaedic surgeon, a medical oncologist, and a radiologist produced a set of core and noncore data items for biopsy and resection specimens based on a critical review and discussion of current evidence. All professionals involved were bone tumour experts affiliated with tertiary referral centres. Commentary was provided for each data item to explain the rationale for selecting it as a core or noncore element, its clinical relevance, and to highlight potential areas of disagreement or lack of evidence, in which case a consensus position was formulated. Following international public consultation, the documents were finalised and ratified, and the datasets, including a synoptic reporting guide, were published on the ICCR website.
CONCLUSION: These first international datasets for bone sarcomas are intended to promote high-quality, standardised pathology reporting. Their widespread adoption will improve the consistency of reporting, facilitate multidisciplinary communication, and enhance comparability of data, all of which will help to improve management of bone sarcoma patients
Recommended from our members
The adaptive designs CONSORT extension (ACE) statement: a checklist with explanation and elaboration guideline for reporting randomised trials that use an adaptive design
Abstract: Adaptive designs (ADs) allow pre-planned changes to an ongoing trial without compromising the validity of conclusions and it is essential to distinguish pre-planned from unplanned changes that may also occur. The reporting of ADs in randomised trials is inconsistent and needs improving. Incompletely reported AD randomised trials are difficult to reproduce and are hard to interpret and synthesise. This consequently hampers their ability to inform practice as well as future research and contributes to research waste. Better transparency and adequate reporting will enable the potential benefits of ADs to be realised. This extension to the Consolidated Standards Of Reporting Trials (CONSORT) 2010 statement was developed to enhance the reporting of randomised AD clinical trials. We developed an Adaptive designs CONSORT Extension (ACE) guideline through a two-stage Delphi process with input from multidisciplinary key stakeholders in clinical trials research in the public and private sectors from 21 countries, followed by a consensus meeting. Members of the CONSORT Group were involved during the development process. The paper presents the ACE checklists for AD randomised trial reports and abstracts, as well as an explanation with examples to aid the application of the guideline. The ACE checklist comprises seven new items, nine modified items, six unchanged items for which additional explanatory text clarifies further considerations for ADs, and 20 unchanged items not requiring further explanatory text. The ACE abstract checklist has one new item, one modified item, one unchanged item with additional explanatory text for ADs, and 15 unchanged items not requiring further explanatory text. The intention is to enhance transparency and improve reporting of AD randomised trials to improve the interpretability of their results and reproducibility of their methods, results and inference. We also hope indirectly to facilitate the much-needed knowledge transfer of innovative trial designs to maximise their potential benefits. In order to encourage its wide dissemination this article is freely accessible on the BMJ and Trials journal websites.âTo maximise the benefit to society, you need to not just do research but do it wellâ Douglas G Altma
Testing the Wyart-Cates model for non-Brownian shear thickening using bidisperse suspensions
There is a growing consensus that shear thickening of concentrated
dispersions is driven by the formation of stress-induced frictional contacts.
The Wyart-Cates (WC) model of this phenomenon, in which the microphysics of the
contacts enters solely via the fraction of contacts that are frictional,
can successfully fit flow curves for suspensions of weakly polydisperse
spheres. However, its validity for "real-life", polydisperse suspensions has
yet to be seriously tested. By performing systematic simulations on bidisperse
mixtures of spheres, we show that the WC model applies only in the monodisperse
limit and fails when substantial bidispersity is introduced. We trace the
failure of the model to its inability to distinguish large-large, large-small
and small-small frictional contacts. By fitting our data using a polydisperse
analogue of that depends separately on the fraction of each of these
contact types, we show that the WC picture of shear thickening is incomplete.
Systematic experiments on model shear-thickening suspensions corroborate our
findings, but highlight important challenges in rigorously testing the WC model
with real systems. Our results prompt new questions about the microphysics of
thickening for both monodisperse and polydisperse systems.Comment: 9 pages, 8 figures, ancillary informatio
- âŠ