6,771 research outputs found
Cultural Heritage conservation and communication by digital modeling tools. Case studies: minor architecture of the Thirties in the Turin area
Between the end of the twenties and the beginning of the World war two Turin, as the most of the Italian cities, was endowed by the
fascist regime of many new buildings to guarantee its visibility and to control the territory: the fascist party main houses and the local
ones.
The style that was adopted for these constructions was inspired by the guide lines of the Modern movement which were spreading by
a generation of architects as Le Corbusier, Gropius, Mendelsohn.
At the end of the war many buildings were reconverted to several functions that led heavy transformations not respectful of the
original worth, other were demolished.
Today it's possible to rebuild those lost architectures in their primal format as it was created by their architects on paper (and in their
mind). This process can guarantee the three-dimensional perception, the authenticity of the materials and the placement into the
Turin urban tissue, using static and dynamic digital representation systems. The “three-dimensional re-drawing” of the projects,
thought as an heuristic practice devoted to reveal the original idea of the project, inserts itself in a digital model of the urban and
natural context as we can live it today, to simulate the perceptive effects that the building could stir up today. The modeling skills are
the basis to product videos able to explore the relationship between the environment and “re-built architectures”, describing with the
synthetic movie techniques, the main formal and perceptive roots. The model represents a scientific product that can be involved in a
virtual archive of cultural goods to preserve the collective memory of the architectural and urban past image of Turin
Random walks and search in time-varying networks
The random walk process underlies the description of a large number of real
world phenomena. Here we provide the study of random walk processes in time
varying networks in the regime of time-scale mixing; i.e. when the network
connectivity pattern and the random walk process dynamics are unfolding on the
same time scale. We consider a model for time varying networks created from the
activity potential of the nodes, and derive solutions of the asymptotic
behavior of random walks and the mean first passage time in undirected and
directed networks. Our findings show striking differences with respect to the
well known results obtained in quenched and annealed networks, emphasizing the
effects of dynamical connectivity patterns in the definition of proper
strategies for search, retrieval and diffusion processes in time-varying
network
Superstar in Noncommutative Superspace via Covariant Quantization of the Superparticle
A covariant quantization method is developed for the off-shell superparticle
in 10 dimensions. On-shell it is consistent with lightcone quantization, while
off-shell it gives a noncommutative superspace that realizes non-linearly a
hidden 11-dimensional super Poincare symmetry. The non-linear commutation rules
are then used to construct the supersymmetric generalization of the covariant
Moyal star product in noncommutative superspace. As one of the possible
applications, we propose this new product as the star product in supersymmetric
string field theory. Furthermore, the formalism introduces new techniques and
concepts in noncommutative (super)geometry.Comment: 17 pages, LaTe
Pore-scale Modeling of Viscous Flow and Induced Forces in Dense Sphere Packings
We propose a method for effectively upscaling incompressible viscous flow in
large random polydispersed sphere packings: the emphasis of this method is on
the determination of the forces applied on the solid particles by the fluid.
Pore bodies and their connections are defined locally through a regular
Delaunay triangulation of the packings. Viscous flow equations are upscaled at
the pore level, and approximated with a finite volume numerical scheme. We
compare numerical simulations of the proposed method to detailed finite element
(FEM) simulations of the Stokes equations for assemblies of 8 to 200 spheres. A
good agreement is found both in terms of forces exerted on the solid particles
and effective permeability coefficients
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Mutation in the MICOS subunit gene APOO (MIC26) associated with an X-linked recessive mitochondrial myopathy, lactic acidosis, cognitive impairment and autistic features.
BACKGROUND: Mitochondria provide ATP through the process of oxidative phosphorylation, physically located in the inner mitochondrial membrane (IMM). The mitochondrial contact site and organising system (MICOS) complex is known as the 'mitoskeleton' due to its role in maintaining IMM architecture. APOO encodes MIC26, a component of MICOS, whose exact function in its maintenance or assembly has still not been completely elucidated. METHODS: We have studied a family in which the most affected subject presented progressive developmental delay, lactic acidosis, muscle weakness, hypotonia, weight loss, gastrointestinal and body temperature dysautonomia, repetitive infections, cognitive impairment and autistic behaviour. Other family members showed variable phenotype presentation. Whole exome sequencing was used to screen for pathological variants. Patient-derived skin fibroblasts were used to confirm the pathogenicity of the variant found in APOO. Knockout models in Drosophila melanogaster and Saccharomyces cerevisiae were employed to validate MIC26 involvement in MICOS assembly and mitochondrial function. RESULTS: A likely pathogenic c.350T>C transition was found in APOO predicting an I117T substitution in MIC26. The mutation caused impaired processing of the protein during import and faulty insertion into the IMM. This was associated with altered MICOS assembly and cristae junction disruption. The corresponding mutation in MIC26 or complete loss was associated with mitochondrial structural and functional deficiencies in yeast and D. melanogaster models. CONCLUSION: This is the first case of pathogenic mutation in APOO, causing altered MICOS assembly and neuromuscular impairment. MIC26 is involved in the assembly or stability of MICOS in humans, yeast and flies
Nuclear Factor of Activated T Cells-dependent Down-regulation of the Transcription Factor Glioma-associated Protein 1 (GLI1) Underlies the Growth Inhibitory Properties of Arachidonic Acid
Numerous reports have demonstrated a tumor inhibitory effect of polyunsaturated fatty acids (PUFAs). However, the molecular mechanisms modulating this phenomenon are in part poorly understood. Here, we provide evidence of a novel antitumoral mechanism of the PUFA arachidonic acid (AA). In vivo and in vitro experiments showed that AA treatment decreased tumor growth and metastasis, and increased apoptosis. Molecular analysis of this effect showed significantly reduced expression of a subset of antiapoptotic proteins, including BCL2, BFL1/A1 and 4-1BB, in AA-treated cells. We demonstrated that downregulation of the transcription factor GLI1 in AA-treated cells is the underlying mechanism controlling BCL2, BFL1/A1 and 4-1BB expression. Using luciferase reporters, chromatin immunoprecipitation, and expression studies, we found that GLI1 binds to the promoter of these antiapoptotic molecules, and regulates their expression and promoter activity. We provide evidence that AA-induced apoptosis and downregulation of antiapoptotic genes can be inhibited by overexpressing GLI1 in AA-sensitive cells. Conversely, inhibition of GLI1 mimics AA treatments, leading to decreased tumor growth, cell viability and expression of antiapoptotic molecules. Further characterization showed that AA represses GLI1 expression by stimulating NFATc1 nuclear translocation, which then binds the GLI1 promoter and represses its transcription. AA was shown to increase reactive oxygen species. Treatment with antioxidants reduced the AA-induced apoptosis, downregulation of GLI1 and NFATc1 activation, indicating that NFATc1 activation and GLI1 repression require the generation of reactive oxygen species. Collectively, these results define a novel mechanism underlying AA antitumoral functions that may serve as a foundation for the future PUFA-based therapeutic approaches
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Search for anomalous t t-bar production in the highly-boosted all-hadronic final state
A search is presented for a massive particle, generically referred to as a
Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are
sufficiently massive to produce highly Lorentz-boosted top quarks, which yield
collimated decay products that are partially or fully merged into single jets.
The analysis uses new methods to analyze jet substructure, providing
suppression of the non-top multijet backgrounds. The analysis is based on a
data sample of proton-proton collisions at a center-of-mass energy of 7 TeV,
corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits
in the range of 1 pb are set on the product of the production cross section and
branching fraction for a topcolor Z' modeled for several widths, as well as for
a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any
enhancement in t t-bar production beyond expectations of the standard model for
t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version
includes a minor typo correction that will be submitted as an erratu
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