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 & Nonlinear system. 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.

Principle of weakly contractive maps in Hilbert spaces

Abstract: We introduce a class of contractive maps on closed convex sets of Hilbert spaces, called weakly contractive maps, which contains the class of strongly contractive maps and which is contained in the class of nonexpansive maps. We prove the existence of fixed points for the weakly contractive maps which are a priori degenerate in general case. We establish then the convergence in norm of classical iterative sequences to fixed points of these maps, give estimates of the convergence rate and prove the stability of the convergence with respect to some perturbations of these maps. Our results extend Banach principle previously known for strongly contractive map only.

The Nature of Partnering Experience and the Gains from Alliances

Abstract: We examine the conditions under which the prior partnering experience of firms contributes to value creation in their new alliances. We propose that prior experience with the same partners, i.e. "partner-specific experience", provides greater benefits than "general partnering experience" that encompasses all prior alliances with any partner. We further explore some of the boundary conditions for the effects of partner-specific experience. We suggest that the effect of partner-specific experience on value creation in alliances is moderated by the extent to which the assets of the new partner differ from those of the firm's prior partners. We also propose that the firm's own technological and financial resources increase the benefits of partner-specific experience. Finally, we predict that the value of partner-specific experience will increase under high levels of firm-specific uncertainty. We test these hypotheses with comprehensive longitudinal multi-industry data on joint ventures formed among Fortune 300 firms between 1987 and 1996. Based on stock market returns to joint-venture announcements, the results provide support for the contingent value of partnering experience. The implications for managing alliances and advancing organizational learning are discussed.

Exciton-polariton topological insulator

Abstract: Topological insulators—materials that are insulating in the bulk but allow electrons to flow on their surface—are striking examples of materials in which topological invariants are manifested in robustness against perturbations such as defects and disorder1. Their most prominent feature is the emergence of edge states at the boundary between areas with different topological properties. The observable physical effect is unidirectional robust transport of these edge states. Topological insulators were originally observed in the integer quantum Hall effect2 (in which conductance is quantized in a strong magnetic field) and subsequently suggested3–5 and observed6 to exist without a magnetic field, by virtue of other effects such as strong spin–orbit interaction. These were systems of correlated electrons. During the past decade, the concepts of topological physics have been introduced into other fields, including microwaves7,8, photonic systems9,10, cold atoms11,12, acoustics13,14 and even mechanics15. Recently, topological insulators were suggested to be possible in exciton-polariton systems16–18 organized as honeycomb (graphene-like) lattices, under the influence of a magnetic field. Exciton-polaritons are part-light, part-matter quasiparticles that emerge from strong coupling of quantum-well excitons and cavity photons19. Accordingly, the predicted topological effects differ from all those demonstrated thus far. Here we demonstrate experimentally an exciton-polariton topological insulator. Our lattice of coupled semiconductor microcavities is excited non-resonantly by a laser, and an applied magnetic field leads to the unidirectional flow of a polariton wavepacket around the edge of the array. This chiral edge mode is populated by a polariton condensation mechanism. We use scanning imaging techniques in real space and Fourier space to measure photoluminescence and thus visualize the mode as it propagates. We demonstrate that the topological edge mode goes around defects, and that its propagation direction can be reversed by inverting the applied magnetic field. Our exciton-polariton topological insulator paves the way for topological phenomena that involve light–matter interaction, amplification and the interaction of exciton-polaritons as a nonlinear many-body system. A part-light, part-matter exciton-polariton topological insulator is created in an array of semiconductor microcavities.

Colistin alone versus colistin plus meropenem for treatment of severe infections caused by carbapenem-resistant Gram-negative bacteria: an open-label, randomised controlled trial

Abstract: Summary Background Colistin–carbapenem combinations are synergistic in vitro against carbapenem-resistant Gram-negative bacteria We aimed to test whether combination therapy improves clinical outcomes for adults with infections caused by carbapenem-resistant or carbapenemase-producing Gram-negative bacteria Methods A randomised controlled superiority trial was done in six hospitals in Israel, Greece, and Italy We included adults with bacteraemia, ventilator-associated pneumonia, hospital-acquired pneumonia, or urosepsis caused by carbapenem-non-susceptible Gram-negative bacteria Patients were randomly assigned (1:1) centrally, by computer-generated permuted blocks stratified by centre, to intravenous colistin (9-million unit loading dose, followed by 4·5 million units twice per day) or colistin with meropenem (2-g prolonged infusion three times per day) The trial was open-label, with blinded outcome assessment Treatment success was defined as survival, haemodynamic stability, improved or stable Sequential Organ Failure Assessment score, stable or improved ratio of partial pressure of arterial oxygen to fraction of expired oxygen for patients with pneumonia, and microbiological cure for patients with bacteraemia The primary outcome was clinical failure, defined as not meeting all success criteria by intention-to-treat analysis, at 14 days after randomisation This trial is registered at ClinicalTrialsgov, number NCT01732250, and is closed to accrual Findings Between Oct 1, 2013, and Dec 31, 2016, we randomly assigned 406 patients to the two treatment groups Most patients had pneumonia or bacteraemia (355/406, 87%), and most infections were caused by Acinetobacter baumannii (312/406, 77%) No significant difference between colistin monotherapy (156/198, 79%) and combination therapy (152/208, 73%) was observed for clinical failure at 14 days after randomisation (risk difference −5·7%, 95% CI −13·9 to 2·4; risk ratio [RR] 0·93, 95% CI 0·83–1·03) Results were similar among patients with A baumannii infections (RR 0·97, 95% CI 0·87–1·09) Combination therapy increased the incidence of diarrhoea (56 [27%] vs 32 [16%] patients) and decreased the incidence of mild renal failure (37 [30%] of 124 vs 25 [20%] of 125 patients at risk of or with kidney injury) Interpretation Combination therapy was not superior to monotherapy The addition of meropenem to colistin did not improve clinical failure in severe A baumannii infections The trial was unpowered to specifically address other bacteria Funding EU AIDA grant Health-F3-2011-278348