Search results for "Hybrid system"
showing 10 items of 98 documents
Impulse-based hybrid motion control
2017
The impulse-based discrete feedback control has been proposed in previous work for the second-order motion systems with damping uncertainties. The sate-dependent discrete impulse action takes place at zero crossing of one of both states, either relative position or velocity. In this paper, the proposed control method is extended to a general hybrid motion control form. We are using the paradigm of hybrid system modeling while explicitly specifying the state trajectories each time the continuous system state hits the guards that triggers impulsive control actions. The conditions for a stable convergence to zero equilibrium are derived in relation to the control parameters, while requiring on…
Emulating Solid-State Physics with a Hybrid System of Ultracold Ions and Atoms
2013
We propose and theoretically investigate a hybrid system composed of a crystal of trapped ions coupled to a cloud of ultracold fermions. The ions form a periodic lattice and induce a band structure in the atoms. This system combines the advantages of scalability and tunability of ultracold atomic systems with the high fidelity operations and detection offered by trapped ion systems. It also features close analogies to natural solid-state systems, as the atomic degrees of freedom couple to phonons of the ion lattice, thereby emulating a solid-state system. Starting from the microscopic many-body Hamiltonian, we derive the low energy Hamiltonian including the atomic band structure and give an…
The CALMA system: an artificial neural network method for detecting masses and microcalcifications in digitized mammograms
2004
The CALMA (Computer Assisted Library for MAmmography) project is a five years plan developed in a physics research frame in collaboration between INFN (Istituto Nazionale di Fisica Nucleare) and many Italian hospitals. At present a large database of digitized mammographic images (more than 6000) was collected and a software based on neural network algorithms for the search of suspicious breast lesions was developed. Two tools are available: a microcalcification clusters hunter, based on supervised and unsupervised feedforward neural network, and a massive lesions searcher, based on a hibrid approach. Both the algorithms analyzed preprocessed digitized images by high frequency filters. Clini…
Polypept(o)ides: Hybrid Systems Based on Polypeptides and Polypeptoids.
2015
Polypept(o)ides combine the multifunctionality and intrinsic stimuli-responsiveness of synthetic polypeptides with the "stealth"-like properties of the polypeptoid polysarcosine (poly(N-methyl glycine)). This class of block copolymers can be synthesized by sequential ring opening polymerization of α-amino acid N-carboxy-anhydrides (NCAs) and correspondingly of the N-substituted glycine N-carboxyanhydride (NNCA). The resulting block copolymers are characterized by Poisson-like molecular weight distributions, full end group integrity, and dispersities below 1.2. While polysarcosine may be able to tackle the currently arising issues regarding the gold standard PEG, including storage diseases i…
Optimal Impulse Control Problems and Linear Programming
2009
Optimal impulse control problems are, in general, difficult to solve. A current research goal is to isolate those problems that lead to tractable solutions. In this paper, we identify a special class of optimal impulse control problems which are easy to solve. Easy to solve means that solution algorithms are polynomial in time and therefore suitable to the on-line implementation in real-time problems. We do this by using a paradigm borrowed from the Operations Research field. As main result, we present a solution algorithm that converges to the exact solution in polynomial time. Our approach consists in approximating the optimal impulse control problem via a binary linear programming proble…
Quantized Dissensus in switching networks with nodes death and duplication* *Research supported by MURST-PRIN “Robust Techniques for uncertain system…
2009
Abstract In this paper we discuss agents exchanging quantized flows to diverge one from the others according to a dissensus protocol. A Quantized Gossip algorithm is considered. Evolutions of the states during switching intervals and at switching instants and their property are described and analyzed. The modeling of switching systems describing networks where death and duplication processes occur is described. Some properties of the topology reached by the network when different rules of duplication and inheritance are implemented.
Protein kinase inhibitor β enhances the constitutive activity of G-protein-coupled zinc receptor GPR39.
2014
GPR39 is a G-protein-coupled zinc receptor that protects against diverse effectors of cell death. Its protective activity is mediated via constitutive activation of Gα13 and the RhoA pathway, leading to increased SRE (serum-response element)-dependent transcription; the zinc-dependent immediate activation of GPR39 involves Gq-mediated increases in cytosolic Ca2+ and Gs coupling leading to increased cAMP levels. We used the cytosolic and soluble C-terminus of GPR39 in a Y2H (yeast-2-hybrid) screen for interacting proteins, thus identifying PKIB (protein kinase A inhibitor β). Co-expression of GPR39 with PKIB increased the protective activity of GPR39 via the constitutive, but not the ligand-…
Materials for skyrmionics
2021
Abstract In recent years, skyrmions have been found in a plethora of different materials encompassing a broad range of bulk compounds as well as a large number of thin film multilayers. Much work has been put forward to study the properties of skyrmions in these systems, especially with respect to employing them in data storage devices, for which their individual strengths and weaknesses have been carefully mapped out. This chapter provides an overview of some of the most common skyrmionics materials that have been used by the community and the properties of the resulting skyrmions. Materials hosting skyrmions are detailed starting with bulk systems as well as thin film systems and more exo…
Bromodomain factor 1 (Bdf1) protein interacts with histones
2001
AbstractUsing a yeast two-hybrid assay we detected an interaction between the N-terminal region of histone H4 (amino acids 1–59) and a fragment of the bromodomain factor 1 protein (Bdf1p) (amino acids 304–571) that includes one of the two bromodomains of this protein. No interaction was observed using fragments of histone H4 sequence smaller than the first 59 amino acids. Recombinant Bdf1p (rBdf1p) demonstrates binding affinity for histones H4 and H3 but not H2A and H2B in vitro. Moreover, rBdf1p is able to bind histones H3 and H4 having different degrees of acetylation. Finally, we have not detected histone acetyltransferase activity associated with Bdf1p.
Isolation of the silicatein-α interactor silintaphin-2 by a novel solid-phase pull-down assay.
2011
The skeleton of siliceous sponges consists of amorphous biogenous silica (biosilica). Biosilica formation is driven enzymatically by means of silicatein(s). During this unique process of enzymatic polycondensation, skeletal elements (spicules) that enfold a central proteinaceous structure (axial filament), mainly comprising silicatein, are formed. However, only the concerted action of silicatein and other proteins can explain the genetically controlled diversity of spicular morphotypes, from simple rods with pointed ends to intricate structures with up to six rays. With the scaffold protein silintaphin-1, a first silicatein interactor that facilitates the formation of the axial filament and…