GridCell: a stochastic particle-based biological system simulator

<p>Abstract</p> <p>Background</p> <p>Realistic biochemical simulators aim to improve our understanding of many biological processes that would be otherwise very difficult to monitor in experimental studies. Increasingly accurate simulators may provide insights into the regulation of biological processes due to stochastic or spatial effects.</p> <p>Results</p> <p>We have developed GridCell as a three-dimensional simulation environment for investigating the behaviour of biochemical networks under a variety of spatial influences including crowding, recruitment and localization. GridCell enables the tracking and characterization of individual particles, leading to insights on the behaviour of low copy number molecules participating in signaling networks. The simulation space is divided into a discrete 3D grid that provides ideal support for particle collisions without distance calculation and particle search. SBML support enables existing networks to be simulated and visualized. The user interface provides intuitive navigation that facilitates insights into species behaviour across spatial and temporal dimensions. We demonstrate the effect of crowing on a Michaelis-Menten system.</p> <p>Conclusion</p> <p>GridCell is an effective stochastic particle simulator designed to track the progress of individual particles in a three-dimensional space in which spatial influences such as crowding, co-localization and recruitment may be investigated.</p

First light of the VLT planet finder SPHERE. I. Detection and characterization of the sub-stellar companion GJ 758 B

GJ758 B is a brown dwarf companion to a nearby (15.76 pc) solar-type, metal-rich (M/H = +0.2 dex) main-sequence star (G9V) that was discovered with Subaru/HiCIAO in 2009. From previous studies, it has drawn attention as being the coldest (~600K) companion ever directly imaged around a neighboring star. We present new high-contrast data obtained during the commissioning of the SPHERE instrument at the VLT. The data was obtained in Y-, J-, H-, and Ks-bands with the dual-band imaging (DBI) mode of IRDIS, providing a broad coverage of the full near-infrared (near-IR) range at higher contrast and better spectral sampling than previously reported. In this new set of high-quality data, we report the re-detection of the companion, as well as the first detection of a new candidate closer-in to the star. We use the new 8 photometric points for an extended comparison of GJ758 B with empirical objects and 4 families of atmospheric models. From comparison to empirical object, we estimate a T8 spectral type, but none of the comparison object can accurately represent the observed near-IR fluxes of GJ758 B. From comparison to atmospheric models, we attribute a Teff = 600K $\pm$ 100K, but we find that no atmospheric model can adequately fit all the fluxes of GJ758 B. The photometry of the new candidate companion is broadly consistent with L-type objects, but a second epoch with improved photometry is necessary to clarify its status. The new astrometry of GJ758 B shows a significant proper motion since the last epoch. We use this result to improve the determination of the orbital characteristics using two fitting approaches, Least-Square Monte Carlo and Markov Chain Monte Carlo. Finally, we analyze the sensitivity of our data to additional closer-in companions and reject the possibility of other massive brown dwarf companions down to 4-5 AU. [abridged]Comment: 20 pages, 15 figures. Accepted for publication in A&

Optimizing Critical Illness Recovery: Perspectives and Solutions from the Caregivers of ICU Survivors

Objectives: To understand the unmet needs of caregivers of ICU survivors, how they accessed support post ICU, and the key components of beneficial ICU recovery support systems as identified from a caregiver perspective. Design: International, qualitative study. Subjects: We conducted 20 semistructured interviews with a diverse group of caregivers in the United States, the United Kingdom, and Australia, 11 of whom had interacted with an ICU recovery program. Setting: Seven hospitals in the United States, United Kingdom, and Australia. Interventions: None. Measurements and Main Results: Content analysis was used to explore prevalent themes related to unmet needs, as well as perceived strategies to improve ICU outcomes. Post-ICU care was perceived to be generally inadequate. Desired caregiver support fell into two main categories: practical support and emotional support. Successful care delivery initiatives included structured programs, such as post discharge telephone calls, home health programs, post-ICU clinics, and peer support groups, and standing information resources, such as written educational materials and online resources. Conclusions: This qualitative, multicenter, international study of caregivers of critical illness survivors identified consistently unmet needs, means by which caregivers accessed support post ICU, and several care mechanisms identified by caregivers as supporting optimal ICU recovery

SPHERE: the exoplanet imager for the Very Large Telescope

Observations of circumstellar environments to look for the direct signal of exoplanets and the scattered light from disks has significant instrumental implications. In the past 15 years, major developments in adaptive optics, coronagraphy, optical manufacturing, wavefront sensing and data processing, together with a consistent global system analysis have enabled a new generation of high-contrast imagers and spectrographs on large ground-based telescopes with much better performance. One of the most productive is the Spectro-Polarimetic High contrast imager for Exoplanets REsearch (SPHERE) designed and built for the ESO Very Large Telescope (VLT) in Chile. SPHERE includes an extreme adaptive optics system, a highly stable common path interface, several types of coronagraphs and three science instruments. Two of them, the Integral Field Spectrograph (IFS) and the Infra-Red Dual-band Imager and Spectrograph (IRDIS), are designed to efficiently cover the near-infrared (NIR) range in a single observation for efficient young planet search. The third one, ZIMPOL, is designed for visible (VIR) polarimetric observation to look for the reflected light of exoplanets and the light scattered by debris disks. This suite of three science instruments enables to study circumstellar environments at unprecedented angular resolution both in the visible and the near-infrared. In this work, we present the complete instrument and its on-sky performance after 4 years of operations at the VLT.Comment: Final version accepted for publication in A&

Autosomal recessive cerebellar ataxia caused by mutations in the PEX2 gene

<p>Abstract</p> <p>Objective</p> <p>To expand the spectrum of genetic causes of autosomal recessive cerebellar ataxia (ARCA).</p> <p>Case report</p> <p>Two brothers are described who developed progressive cerebellar ataxia at 3 1/2 and 18 years, respectively. After ruling out known common genetic causes of ARCA, analysis of blood peroxisomal markers strongly suggested a peroxisomal biogenesis disorder. Sequencing of candidate <it>PEX </it>genes revealed a homozygous c.865_866insA mutation in the <it>PEX2 </it>gene leading to a frameshift 17 codons upstream of the stop codon. <it>PEX </it>gene mutations usually result in a severe neurological phenotype (Zellweger spectrum disorders).</p> <p>Conclusions</p> <p>Genetic screening of PEX2 and other PEX genes involved in peroxisomal biogenesis is warranted in children and adults with ARCA.</p

Photomyogenic response in Niemann–Pick type C: a case report

Contains fulltext : 98214.pdf (publisher's version ) (Closed access)1 maart 201

Virtual Reflexes

Virtual Reality is used successfully to treat people for regular phobias. A new challenge is to develop Virtual Reality Exposure Training for social skills. Virtual actors in such systems have to show appropriate social behavior including emotions, gaze, and keeping distance. The behavior must be realistic and real-time. Current approaches consist of four steps: 1) trainee social signal detection, 2) cognitive-affective interpretation, 3) determination of the appropriate bodily responses, and 4) actuation. The "cognitive" detour of such approaches does not match the directness of human bodily reflexes and causes unrealistic responses and delay. Instead, we propose virtual reflexes as concurrent sensory-motor processes to control virtual actors. Here we present a virtual reflexes architecture, explain how emotion and cognitive modulation are embedded, detail its workings, and give an example description of an aggression training application

Importance of reconnection with ICU survivors to ICU recovery program clinicians

No abstract available