120 research outputs found
The CONCERTO methodology for model-based development of avionics SW
20th International Conference on Reliable Software Technologies - Ada-Europe 2015 (Ada-Europe 2015), 22 to 26, Jun, 2015, Madrid, Spain.The development of high-integrity real-time systems, including
their certification, is a demanding endeavour in terms of time, skills
and effort involved. This is particularly true in application domains such
as the avionics, where composable design is to be had to allow subdividing
monolithic systems into components of smaller complexity, to
be outsourced to developers subcontracted down the supply chain. Moreover,
the increasing demand for computational power and the consequent
interest in multicore HW architectures complicates system deployment.
For these reasons, appropriate methodologies and tools need to be devised
to help the industrial stakeholders master the overall system design
complexity, while keeping manufacturing costs affordable.
In this paper we present some elements of the CONCERTO platform,
a toolset to support the end-to-end system development process from
system modelling to analysis and validation, prior to code generation
and deployment. The approach taken by CONCERTO is demonstrated
for an illustrative avionics setup, however it is general enough to be
applied to a number of industrial domains including the space, telecom
and automotive. We finally reason about the benefits to an industrial
user by comparing to similar initiatives in the research landscape
Design of compensated ferrimagnetic Heusler alloys for giant tunable exchange bias
The discovery of materials with improved functionality can be accelerated by
rational material design. Heusler compounds with tunable magnetic sublattices
allow to implement this concept to achieve novel magnetic properties. Here, we
have designed a family of Heusler alloys with a compensated ferrimagnetic
state. In the vicinity of the compensation composition in Mn-Pt-Ga, a giant
exchange bias (EB) of more than 3 T and a similarly large coercivity are
established. The large exchange anisotropy originates from the exchange
interaction between the compensated host and ferrimagnetic clusters that arise
from intrinsic anti-site disorder. We demonstrate the applicability of our
design concept on a second material, Mn-Fe-Ga, with a magnetic transition above
room temperature, exemplifying the universality of the concept and the
feasibility of room-temperature applications. Our study points to a new
direction for novel magneto-electronic devices. At the same time it suggests a
new route for realizing rare-earth free exchange-biased hard magnets, where the
second quadrant magnetization can be stabilized by the exchange bias.Comment: Four figure
Acute conversion of patient-derived Duchenne muscular dystrophy iPSC into myotubes reveals constitutive and inducible over-activation of TGFβ-dependent pro-fibrotic signaling
Background
In Duchenne muscular dystrophy (DMD), DYSTROPHIN deficiency exposes myofibers to repeated cycles of contraction/degeneration, ultimately leading to muscle loss and replacement by fibrotic tissue. DMD pathology is typically exacerbated by excessive secretion of TGFβ and consequent accumulation of pro-fibrotic components of the extra-cellular matrix (ECM), which in turn impairs compensatory regeneration and complicates the efficacy of therapeutic strategies. It is currently unclear whether DMD skeletal muscle fibers directly contribute to excessive activation of TGFβ. Development of skeletal myofibers from DMD patient-derived induced pluripotent stem cells (iPSC), as an “in dish” model of disease, can be exploited to determine the myofiber contribution to pathogenic TGFβ signaling in DMD and might provide a screening platform for the identification of anti-fibrotic interventions in DMD.
Methods
We describe a rapid and efficient method for the generation of contractile human skeletal muscle cells from DMD patient-derived hiPSC, based on the inducible expression of MyoD and BAF60C (encoded by SMARCD3 gene), using an enhanced version of piggyBac (epB) transposone vectors. DMD iPSC-derived myotubes were tested as an “in dish” disease model and exposed to environmental and mechanical cues that recapitulate salient pathological features of DMD.
Results
We show that DMD iPSC-derived myotubes exhibit a constitutive activation of TGFβ-SMAD2/3 signaling. High-content screening (HCS)-based quantification of nuclear phosphorylated SMAD2/3 signal revealed that DMD iPSC-derived myotubes also exhibit increased activation of the TGFβ-SMAD2/3 signaling following exposure to either recombinant TGFβ or electrical pacing-induced contraction.
Conclusions
Acute conversion of DMD patient-derived iPSC into skeletal muscles, by the ectopic expression of MyoD and BAF60C, provides a rapid and reliable protocol for an “in dish” DMD model that recapitulates key pathogenic features of disease pathology, such as the constitutive activation of the TGFβ/SMAD signaling as well as the deregulated response to pathogenic stimuli, e.g., ECM-derived signals or mechanical cues. Thus, this model is suitable for the identification of new therapeutic targets in DMD patient-specific muscles
Bicuspid Aortic Valve Disease: Classifications, Treatments, and Emerging Transcatheter Paradigms
Bicuspid aortic valve (BAV) is a common congenital valvular malformation, which may lead to early aortic valve disease and bicuspid-associated aortopathy. A novel BAV classification system was recently proposed to coincide with transcatheter aortic valve replacement being increasingly considered in younger patients with symptomatic BAV, with good clinical results, yet without randomized trial evidence. Procedural technique, along with clinical outcomes, have considerably improved in BAV patients compared with tricuspid aortic stenosis patients undergoing transcatheter aortic valve replacement. The present review summarizes the novel BAV classification systems and examines contemporary surgical and transcatheter approaches
Pathogen and human NDPK-proteins promote AML cell survival via monocyte NLRP3-inflammasome activation
A history of infection has been linked with increased risk of acute myeloid leukaemia (AML) and related myelodysplastic syndromes (MDS). Furthermore, AML and MDS patients suffer frequent infections because of disease-related impaired immunity. However, the role of infections in the development and progression of AML and MDS remains poorly understood. We and others previously demonstrated that the human nucleoside diphosphate kinase (NDPK) NM23-H1 protein promotes AML blast cell survival by inducing secretion of IL-1β from accessory cells. NDPKs are an evolutionary highly conserved protein family and pathogenic bacteria secrete NDPKs that regulate virulence and host-pathogen interactions. Here, we demonstrate the presence of IgM antibodies against a broad range of pathogen NDPKs and more selective IgG antibody activity against pathogen NDPKs in the blood of AML patients and normal donors, demonstrating that in vivo exposure to NDPKs likely occurs. We also show that pathogen derived NDPK-proteins faithfully mimic the catalytically independent pro-survival activity of NM23-H1 against primary AML cells. Flow cytometry identified that pathogen and human NDPKs selectively bind to monocytes in peripheral blood. We therefore used vitamin D3 differentiated monocytes from wild type and genetically modified THP1 cells as a model to demonstrate that NDPK-mediated IL-1β secretion by monocytes is NLRP3-inflammasome and caspase 1 dependent, but independent of TLR4 signaling. Monocyte stimulation by NDPKs also resulted in activation of NF-κB and IRF pathways but did not include the formation of pyroptosomes or result in pyroptotic cell death which are pivotal features of canonical NLRP3 inflammasome activation. In the context of the growing importance of the NLRP3 inflammasome and IL-1β in AML and MDS, our findings now implicate pathogen NDPKs in the pathogenesis of these diseases
The LISA beamline at ESRF.
This contribution provides a description of LISA, the new Italian Collaborating Research Group beamline operative at the European Synchrotron Radiation Facility. A presentation of the instruments available and optical devices is given as well as the main X-ray parameters (flux, energy resolution, focal spot dimensions, etc.) and comparison with theoretical calculations. The beamline has been open to users since April 2018 and will be ready at the opening of the Extremely Brilliant Source in late-2020
The effect of internal pressure on the tetragonal to monoclinic structural phase transition in ReOFeAs: the case of NdOFeAs
We report the temperature dependent x-ray powder diffraction of the
quaternary compound NdOFeAs (also called NdFeAsO) in the range between 300 K
and 95 K. We have detected the structural phase transition from the tetragonal
phase, with P4/nmm space group, to the orthorhombic or monoclinic phase, with
Cmma or P112/a1 (or P2/c) space group, over a broad temperature range from 150
K to 120 K, centered at T0 ~137 K. Therefore the temperature of this structural
phase transition is strongly reduced, by about ~30K, by increasing the internal
chemical pressure going from LaOFeAs to NdOFeAs. In contrast the
superconducting critical temperature increases from 27 K to 51 K going from
LaOFeAs to NdOFeAs doped samples. This result shows that the normal striped
orthorhombic Cmma phase competes with the superconducting tetragonal phase.
Therefore by controlling the internal chemical pressure in new materials it
should be possible to push toward zero the critical temperature T0 of the
structural phase transition, giving the striped phase, in order to get
superconductors with higher Tc.Comment: 9 pages, 3 figure
- …