Technion – Israel Institute of Technology

About: Technion – Israel Institute of Technology is a education organization based out in Haifa, Israel. It is known for research contribution in the topics: Population & Upper and lower bounds. The organization has 31714 authors who have published 79377 publications receiving 2603976 citations. The organization is also known as: Technion Israel Institute of Technology & Ṭekhniyon, Makhon ṭekhnologi le-Yiśraʼel.

Model checking and abstraction

Abstract: We describe a method for using abstraction to reduce the complexity of temporal-logic model checking. Using techniques similar to those involved in abstract interpretation, we construct an abstract model of a program without ever examining the corresponding unabstracted model. We show how this abstract model can be used to verify properties of the original program. We have implemented a system based on these techniques, and we demonstrate their practicality using a number of examples, including a program representing a pipelined ALU circuit with over 101300 states.

INFOGEST static in vitro simulation of gastrointestinal food digestion

Abstract: Developing a mechanistic understanding of the impact of food structure and composition on human health has increasingly involved simulating digestion in the upper gastrointestinal tract. These simulations have used a wide range of different conditions that often have very little physiological relevance, and this impedes the meaningful comparison of results. The standardized protocol presented here is based on an international consensus developed by the COST INFOGEST network. The method is designed to be used with standard laboratory equipment and requires limited experience to encourage a wide range of researchers to adopt it. It is a static digestion method that uses constant ratios of meal to digestive fluids and a constant pH for each step of digestion. This makes the method simple to use but not suitable for simulating digestion kinetics. Using this method, food samples are subjected to sequential oral, gastric and intestinal digestion while parameters such as electrolytes, enzymes, bile, dilution, pH and time of digestion are based on available physiological data. This amended and improved digestion method (INFOGEST 2.0) avoids challenges associated with the original method, such as the inclusion of the oral phase and the use of gastric lipase. The method can be used to assess the endpoints resulting from digestion of foods by analyzing the digestion products (e.g., peptides/amino acids, fatty acids, simple sugars) and evaluating the release of micronutrients from the food matrix. The whole protocol can be completed in ~7 d, including ~5 d required for the determination of enzyme activities.

The ubiquitin system for protein degradation

Abstract: PERSPECTIVES AND SUMMARy 762 INTRODUCTION 762 ENZYMES OF UBIQUITIN ACTIVATION AND LIGATION 764 Ubiq u it in -Activatin g En zyme, E } . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . 764 Ubiquitin-Carrier Proteins, E2s 767 Ubiq uit in -Protein Ligases, E3s.. ... ........ ... . ... . .... .. . 771 DEGRADATION OF PROTEINS LIGATED TO UBIQUITIN 775 The 26S Protease Complex and its Three Components 775 Identification of CF-3 as the 20S P rotea se Complex . . . . . . . . . . . . . . . . . .... . . . .. . .... . . . . . . . 777 P ossible Role s of ATP 780 UBIQUITIN-C-TERMINAL HYDROLASES 781 SIGNALS IN PROTEINS FOR UBIQUITIN-MEDIATED DEGRADATION 786 The N-Term ina l Recognition Signa l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . 786 Sign als t hat are Distinct from the N-Term in al Re sid ue .... . . ......... 790 DEGRADATION OF SPECIFIC CELLULAR PROTEINS BY THE UBIQUITIN SYSTEM: REGULATORY ASPECTS 792 P hytochrome . . . . .. . . . . . . . 792 Oncoprotein s. . ... . .... . . .... ....... . ..... .... ..... ..... . ... . ........ . ...... ......... . ... 794 MATaJ. Repre ssor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 795 Cyclin s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 796 DIVERSE FUNCTIONS OF UBIQUITIN CONJUGATION.. 799 CONCLUDING REMARKS 801

Berry's phase for energy bands in solids

Abstract: Berry's phase is defined for the dynamics of electrons in periodic solids and an explicit formula is derived for it. Because of the special torus topology of the Brillouin zone a nonzero Berry phase is shown to exist in a one-dimensional parameter space. Symmetry of the Bloch functions in the Brillouin zone leads to the quantization of Berry's phase. A connection is established between the latter and the Wyckoff positions in the crystal in the framework of band representations of space groups. Berry's phase can therefore be used for labeling energy bands in solids.

Transport and Anderson localization in disordered two-dimensional photonic lattices

Abstract: One of the most interesting phenomena in solid-state physics is Anderson localization, which predicts that an electron may become immobile when placed in a disordered lattice. The origin of localization is interference between multiple scatterings of the electron by random defects in the potential, altering the eigenmodes from being extended (Bloch waves) to exponentially localized. As a result, the material is transformed from a conductor to an insulator. Anderson's work dates back to 1958, yet strong localization has never been observed in atomic crystals, because localization occurs only if the potential (the periodic lattice and the fluctuations superimposed on it) is time-independent. However, in atomic crystals important deviations from the Anderson model always occur, because of thermally excited phonons and electron-electron interactions. Realizing that Anderson localization is a wave phenomenon relying on interference, these concepts were extended to optics. Indeed, both weak and strong localization effects were experimentally demonstrated, traditionally by studying the transmission properties of randomly distributed optical scatterers (typically suspensions or powders of dielectric materials). However, in these studies the potential was fully random, rather than being 'frozen' fluctuations on a periodic potential, as the Anderson model assumes. Here we report the experimental observation of Anderson localization in a perturbed periodic potential: the transverse localization of light caused by random fluctuations on a two-dimensional photonic lattice. We demonstrate how ballistic transport becomes diffusive in the presence of disorder, and that crossover to Anderson localization occurs at a higher level of disorder. Finally, we study how nonlinearities affect Anderson localization. As Anderson localization is a universal phenomenon, the ideas presented here could also be implemented in other systems (for example, matter waves), thereby making it feasible to explore experimentally long-sought fundamental concepts, and bringing up a variety of intriguing questions related to the interplay between disorder and nonlinearity.