193 research outputs found
T cell receptor for antigen induces linker for activation of T cellâdependent activation of a negative signaling complex involving Dok-2, SHIP-1, and Grb-2
Adaptor proteins positively or negatively regulate the T cell receptor for antigen (TCR) signaling cascade. We report that after TCR stimulation, the inhibitory adaptor downstream of kinase (Dok)-2 and its homologue Dok-1 are involved in a multimolecular complex including the lipid phosphatase Src homology 2 domainâcontaining inositol polyphosphate 5âČ-phosphatase (SHIP)-1 and Grb-2 which interacts with the membrane signaling scaffold linker for activation of T cells (LAT). Knockdown of LAT and SHIP-1 expression indicated that SHIP-1 favored recruitment of Dok-2 to LAT. Knockdown of Dok-2 and Dok-1 revealed their negative control on Akt and, unexpectedly, on Zap-70 activation. Our findings support the view that Dok-1 and -2 are critical elements of a LAT-dependent negative feedback loop that attenuates early TCR signal. Dok-1 and -2 may therefore exert a critical role in shaping the immune response and as gatekeepers for T cell tolerance
Odyssey 2 : A mission toward Neptune and Triton to test General Relativity
Odyssey 2 will be proposed in December 2010 for the next call of M3 missions
for Cosmic Vision 2015-2025. This mission, under a Phase 0 study performed by
CNES, will aim at Neptune and Triton. Two sets of objectives will be pursued.
The first one is to perform a set of gravitation experiments at the Solar
System scale. Experimental tests of gravitation have always shown good
agreement with General Relativity. There are however drivers to continue
testing General Relativity, and to do so at the largest possible scales. From a
theoretical point of view, Einstein's theory of gravitation shows
inconsistencies with a quantum description of Nature and unified theories
predict deviations from General Relativity. From an observational point of
view, as long as dark matter and dark energy are not observed through other
means than their gravitational effects, they can be considered as a
manifestation of a modification of General Relativity at cosmic scales. The
scientific objectives are to: (i) test the gravitation law at the Solar System
scale; (ii) measure the Eddington parameter; and (iii) investigate the
navigation anomalies during fly-bys. To fulfil these objectives, the following
components are to be on board the spacecraft: (i) the Gravity Advanced Package
(GAP), which is an electrostatic accelerometer to which a rotating stage is
added; (ii) radio-science; (iii) laser ranging, to improve significantly the
measure of the Eddington parameter. The second set of objectives is to enhance
our knowledge of Neptune and Triton. Several instruments dedicated to
planetology are foreseen: camera, spectrometer, dust and particle detectors,
and magnetometer. Depending on the ones kept, the mission could provide
information on the gravity field, the atmosphere and the magnetosphere of the
two bodies as well as on the surface geology of Triton and on the nature of the
planetary rings around Neptune.Comment: 61st International Astronautical Congress (Prague, Czech Republic -
September 2010), 7 page
Growth of Yersinia pseudotuberculosis in human plasma: impacts on virulence and metabolic gene expression
<p>Abstract</p> <p>Background</p> <p>In man, infection by the Gram-negative enteropathogen <it>Yersinia pseudotuberculosis </it>is usually limited to the terminal ileum. However, in immunocompromised patients, the microorganism may disseminate from the digestive tract and thus cause a systemic infection with septicemia.</p> <p>Results</p> <p>To gain insight into the metabolic pathways and virulence factors expressed by the bacterium at the blood stage of pseudotuberculosis, we compared the overall gene transcription patterns (the transcriptome) of bacterial cells cultured in either human plasma or Luria-Bertani medium. The most marked plasma-triggered metabolic consequence in <it>Y. pseudotuberculosis </it>was the switch to high glucose consumption, which is reminiscent of the acetogenic pathway (known as "glucose overflow") in <it>Escherichia coli</it>. However, upregulation of the glyoxylate shunt enzymes suggests that (in contrast to <it>E. coli</it>) acetate may be further metabolized in <it>Y. pseudotuberculosis</it>. Our data also indicate that the bloodstream environment can regulate major virulence genes (positively or negatively); the <it>yadA </it>adhesin gene and most of the transcriptional units of the pYV-encoded type III secretion apparatus were found to be upregulated, whereas transcription of the pH6 antigen locus was strongly repressed.</p> <p>Conclusion</p> <p>Our results suggest that plasma growth of <it>Y. pseudotuberculosis </it>is responsible for major transcriptional regulatory events and prompts key metabolic reorientations within the bacterium, which may in turn have an impact on virulence.</p
Laser-chemical vapor deposition of W Schottky contacts on GaAs\ud using WF6 and SiH4
Reports on the deposition of tungsten on gallium arsenide (GaAs) using a low-temperature laser-chemical vapor deposition process. Induction of metallic W formation from a gas mixture; Columnar structure shown by scanning electron microscopy of the W films; Schottky diodes obtained during a laser based resistless projection patterning process on GaAs
Environmental metabarcoding reveals contrasting belowground and aboveground fungal communities from poplar at a Hg phytomanagement site
Characterization of microbial communities in stressful conditions at a field level is rather scarce, especially when considering fungal communities from aboveground habitats. We aimed at characterizing fungal communities from different poplar habitats at a Hg-contaminated phytomanagement site by using Illumina-based sequencing, network analysis approach, and direct isolation of Hg-resistant fungal strains. The highest diversity estimated by the Shannon index was found for soil communities, which was negatively affected by soil Hg concentration. Among the significant correlations between soil operational taxonomic units (OTUs) in the co-occurrence network, 80% were negatively correlated revealing dominance of a pattern of mutual exclusion. The fungal communities associated with Populus roots mostly consisted of OTUs from the symbiotic guild, such as members of the Thelephoraceae, thus explaining the lowest diversity found for root communities. Additionally, root communities showed the highest network connectivity index, while rarely detected OTUs from the Glomeromycetes may have a central role in the root network. Unexpectedly high richness and diversity were found for aboveground habitats, compared to the root habitat. The aboveground habitats were dominated by yeasts from the Lalaria, Davidiella, and Bensingtonia genera, not detected in belowground habitats. Leaf and stem habitats were characterized by few dominant OTUs such as those from the Dothideomycete class producing mutual exclusion with other OTUs. Aureobasidium pullulans, one of the dominating OTUs, was further isolated from the leaf habitat, in addition to Nakazawaea populi species, which were found to be Hg resistant. Altogether, these findings will provide an improved point of reference for microbial research on inoculation-based programs of tailings dumps
Womenâs beliefs about medicines and adherence to pharmacotherapy in pregnancy: Opportunities for community pharmacists?
Background During pregnancy women might weigh benefits of treatment against potential risks to the unborn child. However, non-adherence to necessary treatment can adversely affect both mother and child. To optimize pregnant womenâs beliefs and medication adherence, community pharmacists are ideally positioned to play an important role in primary care. Objective This narrative review aimed to summarize the evidence on 1) pregnant womenâs beliefs, 2) medication adherence in pregnancy, and 3) community pharmacistsâ counselling during pregnancy. Method Three search strategies were used in Medline and Embase to find original studies evaluating womenâs beliefs, medication adherence and community pharmacistsâ counselling during pregnancy. All original descriptive and analytic epidemiological studies performed in Europe, North America and Australia, written in English and published from 2000 onwards were included. Results We included 14 studies reporting on womenâs beliefs, 11 studies on medication adherence and 9 on community pharmacistsâ counselling during pregnancy. Women are more reluctant to use medicines during pregnancy and tend to overestimate the teratogenic risk of medicines. Risk perception varies with type of medicine, level of health literacy, education level and occupation. Furthermore, low medication adherence during pregnancy is common. Finally, limited evidence showed current community pharmacistsâ counselling is insufficient. Barriers hindering pharmacists are insufficient knowledge and limited access to reliable information. Conclusion Concerns about medication use and non-adherence are widespread among pregnant women. Community pharmacistsâ counselling during pregnancy is insufficient. Further education, training and research are required to support community pharmacists in fulfilling all the opportunities they have when counselling pregnant women
Recommendations for the Use of Serious Games in Neurodegenerative Disorders: 2016 Delphi Panel
International audienceThe use of Serious Games (SG) in the health domain is expanding. In the field of neurodegenerative disorders (ND) such as Alzheimerâs disease, SG are currently employed both to support and improve the assessment of different functional and cognitive abilities, and to provide alternative solutions for patientsâ treatment, stimulation, and rehabilitation. As the field is quite young, recommendations on the use of SG in people with ND are still rare. In 2014 we proposed some initial recommendations (Robert et al., 2014). The aim of the present work was to update them, thanks to opinions gathered by experts in the field during an expert Delphi panel. Results confirmed that SG are adapted to elderly people with mild cognitive impairment (MCI) and dementia, and can be employed for several purposes, including assessment, stimulation, and improving wellbeing, with some differences depending on the population (e.g., physical stimulation may be better suited for people with MCI). SG are more adapted for use with trained caregivers (both at home and in clinical settings), with a frequency ranging from 2 to 4 times a week. Importantly, the target of SG, their frequency of use and the context in which they are played depend on the SG typology (e.g., Exergame, cognitive game), and should be personalized with the help of a clinician
Recommendations for the Use of Serious Games in Neurodegenerative Disorders: 2016 Delphi Panel
The use of Serious Games (SG) in the health domain is expanding. In the field of neurodegenerative disorders (ND) such as Alzheimerâs disease, SG are currently employed both to support and improve the assessment of different functional and cognitive abilities, and to provide alternative solutions for patientsâ treatment, stimulation, and rehabilitation. As the field is quite young, recommendations on the use of SG in people with ND are still rare. In 2014 we proposed some initial recommendations (Robert et al., 2014). The aim of the present work was to update them, thanks to opinions gathered by experts in the field during an expert Delphi panel. Results confirmed that SG are adapted to elderly people with mild cognitive impairment (MCI) and dementia, and can be employed for several purposes, including assessment, stimulation, and improving wellbeing, with some differences depending on the population (e.g., physical stimulation may be better suited for people with MCI). SG are more adapted for use with trained caregivers (both at home and in clinical settings), with a frequency ranging from 2 to 4 times a week. Importantly, the target of SG, their frequency of use and the context in which they are played depend on the SG typology (e.g., Exergame, cognitive game), and should be personalized with the help of a clinician
Euclid Near Infrared Spectrometer and Photometer instrument concept and first test results obtained for different breadboards models at the end of phase C
The Euclid mission objective is to understand why the expansion of the Universe is accelerating through by mapping the geometry of the dark Universe by investigating the distance-redshift relationship and tracing the evolution of cosmic structures. The Euclid project is part of ESA's Cosmic Vision program with its launch planned for 2020 (ref [1]). The NISP (Near Infrared Spectrometer and Photometer) is one of the two Euclid instruments and is operating in the near-IR spectral region (900- 2000nm) as a photometer and spectrometer. The instrument is composed of: - a cold (135K) optomechanical subsystem consisting of a Silicon carbide structure, an optical assembly (corrector and camera lens), a filter wheel mechanism, a grism wheel mechanism, a calibration unit and a thermal control system - a detection subsystem based on a mosaic of 16 HAWAII2RG cooled to 95K with their front-end readout electronic cooled to 140K, integrated on a mechanical focal plane structure made with molybdenum and aluminum. The detection subsystem is mounted on the optomechanical subsystem structure - a warm electronic subsystem (280K) composed of a data processing / detector control unit and of an instrument control unit that interfaces with the spacecraft via a 1553 bus for command and control and via Spacewire links for science data This presentation describes the architecture of the instrument at the end of the phase C (Detailed Design Review), the expected performance, the technological key challenges and preliminary test results obtained for different NISP subsystem breadboards and for the NISP Structural and Thermal model (STM)
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