Showing papers by "Technion – Israel Institute of Technology published in 1996"
TL;DR: It is proved that a necessary condition for separability is that a matrix, obtained by partial transposition of {rho}, has only non-negative eigenvalues.
Abstract: A quantum system consisting of two subsystems is separable if its density matrix can be written as $\ensuremath{\rho}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{\Sigma}{A}^{}{w}_{A}{\ensuremath{\rho}}_{A}^{\ensuremath{'}}\ensuremath{\bigotimes}{\ensuremath{\rho}}_{A}^{\ensuremath{'}\ensuremath{'}},$ where ${\ensuremath{\rho}}_{A}^{\ensuremath{'}}$ and ${\ensuremath{\rho}}_{A}^{\ensuremath{'}\ensuremath{'}}$ are density matrices for the two subsystems, and the positive weights ${w}_{A}$ satisfy $\ensuremath{\Sigma}{w}_{A}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1$ In this Letter, it is proved that a necessary condition for separability is that a matrix, obtained by partial transposition of \ensuremath{\rho}, has only non-negative eigenvalues Some examples show that this criterion is more sensitive than Bell's inequality for detecting quantum inseparability
4,432 citations
01 Jan 1996
TL;DR: The client would like to get a larger, approximately 3 cm in diameter, well fixed tissue sample, together with a detailed report of the clinical presentation, gross, and microscopic lesions, along with the submission of samples prepared in a similar manner by the client for processing.
Abstract: We wrote it to be read by, and taught to, senior undergraduates and starting graduate students, rather than studied in a research laboratory. We wrote it using the same style and sentence construction that we have used in countless classroom lectures, rather than how we have written our countless (and much-less read) formal scientificpapers. In this respect particularly, wehave been deliberate in notreferencing the sources of every experimental fact or theoretical concept (although we do include some hints and clues in the chapters). However, at the end of each chapter we have included groups of references that should lead you to the best sources in the literature and help you go into more depth as you become more confident about what you are looking for. We are great believers in the value of history as the basis for under- standing the present and so the history of the techniques and key historical references are threaded throughout the book. Just because a reference is dated in the previous century (or even the antepenultimate century) doesn’t mean it isn’t useful! Likewise, with the numerous figures drawn from across the fields of materials science and engineering and nanotechnology, we do not reference the source in each caption. But at the very end of the book each of our many generous colleagues whose work we have used is clearly acknowledged.
4,412 citations
Book•
01 Jan 1996TL;DR: This chapter surveys the theory of two-party communication complexity and presents results regarding the following models of computation: • Finite automata • Turing machines • Decision trees • Ordered binary decision diagrams • VLSI chips • Networks of threshold gates.
Abstract: In this chapter we survey the theory of two-party communication complexity. This field of theoretical computer science aims at studying the following, seemingly very simple, scenario: There are two players Alice who holds an n-bit string x and Bob who holds an n-bit string y. Their goal is to communicate in order to compute the value of some boolean function f(x, y), while exchanging a number of bits which is as small as possible. In the first part of this survey we present, mainly by giving examples, some of the results (and techniques) developed as part of this theory. We put an emphasis on proving lower bounds on the amount of communication that must be exchanged in the above scenario for certain functions f . In the second part of this survey we will exemplify the wide applicability of the results proved in the first part to other areas of computer science. While it is obvious that there are many applications of the results to problems in which communication is involved (e.g., in distributed systems), we concentrate on applications in which communication does not appear explicitly in the statement of the problems. In particular, we present results regarding the following models of computation: • Finite automata • Turing machines • Decision trees • Ordered binary decision diagrams (OBDDs) • VLSI chips • Networks of threshold gates We provide references to many other issues and applications of communication complexity which are not discussed in this survey.
2,004 citations
TL;DR: It is demonstrated using Northern analysis that treatment of various cell lines with IL-6 for 6-48 h results in a significant induction of VEGF mRNA, and it is shown that the 5′-UTR is important for the expression of V EGF.
1,045 citations
TL;DR: This paper presents a computational study of part of the lexical-acquisition task faced by children, namely the acquisition of word-to-meaning mappings, and presents an implemented algorithm for solving this problem, illustrating its operation on a small example.
524 citations
TL;DR: In this paper, it was shown that every ANN-person game has the fictitious play property and has identical interests if it is best response equivalent in mixed strategies to a game with identical payoff functions.
505 citations
TL;DR: In this article, the strategic reference point (SRP) matrix is developed, and a theory is developed which posits an optimal SRP structure, and propositions are offered which articulate the expected relationships between the SRP, strategic choice behavior, and firm performance.
Abstract: How can executives achieve a match between expected external environmental conditions and internal organizational capabilities that facilitates improved performance? This paper argues that a firm's choice of ‘reference points’ can help achieve strategic alignment capable of yielding improved performance and potentially even a sustainable competitive advantage. Building upon prospect theory and other relevant theoretical perspectives, the strategic reference point (SRP) matrix is developed. A firm's SRP consists of three dimensions: internal capability, external conditions, and time. A theory is developed which posits an optimal SRP structure, and propositions are offered which articulate the expected relationships between the SRP, strategic choice behavior, and firm performance. The paper closes with some suggestions for using strategic reference points in both research and practice.
459 citations
TL;DR: A new type of signature scheme, which consists of two phases, which is supposed to be very fast, is proposed, which uses one-time signature schemes, which are very fast for the on-line signing and an ordinary signature scheme is used for the off-line stage.
Abstract: A new type of signature scheme is proposed. It consists of two phases. The first phase is performed off-line, before the message to be signed is even known. The second phase is performed on-line, once the message to be signed is known, and is supposed to be very fast. A method for constructing such on-line/off-line signature schemes is presented. The method uses one-time signature schemes, which are very fast, for the on-line signing. An ordinary signature scheme is used for the off-line stage.
In a practical implementation of our scheme, we use a variant of Rabin's signature scheme (based on factoring) and DES. In the on-line phase all we use is a moderate amount of DES computation and a single modular multiplication. We stress that the costly modular exponentiation operation is performed off-line. This implementation is ideally suited for electronic wallets or smart cards.
451 citations
TL;DR: In this paper, the Raman spectra of a set of hydrogen-free diamond-like carbon (DLC) films were obtained under conditions that result in different types of carbon bonding and for which the sp 2 :sp 3 content was independently determined by electron energy loss spectroscopy.
437 citations
430 citations
TL;DR: An extension of the van der Waerden and Szemeredi the- orems for commuting operators whose exponents are polynomials is proved in this paper, where the authors obtain the following result: for any vector u ∈ Zl such that u+ pi(n)vi ∈ S for each i ≤ k
Abstract: An extension of the classical van der Waerden and Szemeredi the- orems is proved for commuting operators whose exponents are polynomials As a consequence, for example, one obtains the following result: Let S ⊆ Zl be a set of positive upper Banach density, let p1(n), , pk(n) be polynomials with rational coefficients taking integer values on the integers and satisfying pi(0) = 0, i = 1, , k; then for any v1, , vk ∈ Zl there exist an integer n and a vector u ∈ Zl such that u+ pi(n)vi ∈ S for each i ≤ k Department of Mathematics, Ohio State University, Columbus, Ohio 43210 E-mail address: vitaly@mathohio-stateedu Department of Mathematics, Technion, Haifa 23000, Israel E-mail address: sashal@techunixtechnionacil Current address: Department of Mathematics, Stanford University, Stanford, California 94305 E-mail address: leibman@mathstanfordedu License or copyright restrictions may apply to redistribution; see http://wwwamsorg/journal-terms-of-use
TL;DR: It is shown that misexpression of Kn1 confers different phenotypes on simple and compound leaves, and that the two alternative leaf forms are conditioned by different developmental programs in the primary appendage that is common to all types of leaves.
TL;DR: It was concluded that certain tumor-derived cell lines express novel surface-associated receptors that selectively bind VEGF via the exon 7-encoded domain, which is absent in VEGf.
TL;DR: In this paper, a mathematical model is developed to allow performance prediction of all-liquid noncontacting mechanical seals with regular micro-surface structure in the form of hemispherical pores, and an optimum pore size is found that depends on the other variables and corresponds to maximum axial stiffness and minimum friction torque.
Abstract: A mathematical model is developed to allow performance prediction of all-liquid noncontacting mechanical seals with regular microsurface structure in the form of hemispherical pores. Seal performance such as the equilibrium face separation, friction torque and leakage across the seal are calculated and presented for a range of sealed pressure, pore size and pore ratio of ring surface area. An optimum pore size is found that depends on the other variables and corresponds to maximum axial stiffness and minimum friction torque. Also, a critical pore size is found above which seal failure is possible. Presented as a Society of Tribologists and Lubrication Engineers paper at the STLE/ASME Tribology Conference in Kisslmmee, Florida, October 8–11, 1995
TL;DR: In this paper, the role of π-electron deformation in low-energy ionization processes was theoretically analyzed using thermodynamic, structural, and magnetic criteria, and the properties of the charge distributions.
Abstract: Thermodynamic, structural, and magnetic criteria, the properties of the charge distributions, and low-energy ionization processes are theoretically analyzed to learn about the role of π-electron de...
TL;DR: In this paper, an individual-based approach is used to relate collective behavior to individual decisions, in which the motion of an individual in a herd is assumed to be the combined result of both densityindependent and density-dependent decisions, based on the influence of surrounding neighbors.
TL;DR: The trade-off between the information gain and that disturbance in the act of observation is investigated, and the optimal detection method is explicitly found in the case of two equiprobable nonorthogonal pure states.
Abstract: When an observer wants to identify a quantum state, which is known to be one of a given set of nonorthogonal states, the act of observation causes a disturbance to that state. We investigate the trade-off between the information gain and that disturbance. This issue has important applications in quantum cryptography. The optimal detection method, for a given tolerated disturbance, is explicitly found in the case of two equiprobable nonorthogonal pure states. \textcopyright{} 1996 The American Physical Society.
TL;DR: In this article, it was shown that the zero level set of the solution to the Cahn-Hilliard equation with a concentration dependent mobility approximates to lowest order in an interface evolving according to the geometric motion.
Abstract: We show by using formal asymptotics that the zero level set of the solution to the Cahn–Hilliard equation with a concentration dependent mobility approximates to lowest order in ɛ an interface evolving according to the geometric motion,(where V is the normal velocity, Δ8 is the surface Laplacian and κ is the mean curvature of the interface), both in the deep quench limit and when the temperature θ is where є2 is the coefficient of gradient energy Equation (01) may be viewed as motion by surface diffusion, and as a higher-order analogue of motion by mean curvature predicted by the bistable reaction-diffusion equation
TL;DR: The incidence of heterotopic pregnancies increased in recent years because of the escalating use of new reproductive technologies in infertile patients and has stabilized at approximately 1:100 pregnancies with these procedures.
TL;DR: The present review focuses on the involvement of HS in basic FGF (bFGF) receptor binding and mitogenic activity and its modulation by species of heparin, HS, and synthetic polyanionic ‘heparin-mimicking’ compounds.
Abstract: Heparan sulfate proteoglycans (HSPGs) are ubiquitous macromolecules associated with the cell surface and extracellular matrix (ECM) of a wide range of cells of vertebrate and invertebrate tissues [1, 2]. The basic HSPG structure consists of a protein core to which several linear heparan sulfate (HS) chains are covalently attached. The polysaccharide chains are typically composed of repeating hexuronic and D-glucosamine disaccharide units that are substituted to a varying extent with N- and O-linked sulfate moieties and N-linked acetyl groups [1, 2]. Beside serving as a scaffold for the attachment of various ECM components (e.g., collagen, laminin, fibronectin), the binding of HS to certain proteins has been suggested to induce a conformational change which may lead to the exposure of novel reactive determinants or conversely stabilize an inert protein configuration [1-4]. Of particular significance is the interaction of HS with fibroblast growth factors (FGFs), mediating their sequestration, stabilization and high affinity receptor binding and signaling [3-7]. Cellular responses to FGFs may hence be modulated by metabolic inhibitors of HS synthesis and sulfation, HS-degrading enzymes, and synthetic mimetics of heparin/HS. In the present review we focus on the involvement of HS in basic FGF (bFGF) receptor binding and mitogenic activity and its modulation by species of heparin, HS, and synthetic polyanionic 'heparin-mimicking' compounds. The results are discussed in relation to the current thoughts on the dual involvement of low and high affinity receptor sites in the growth promoting and angiogenic activities of bFGF and other heparin-binding growth factors.
TL;DR: The findings indicate that VVOs provide a major pathway for the extravasation of circulating macromolecules across endothelia taller than capillary endothelium and suggest that upregulated VVO function accounts for the well‐known hyperpermeability of tumor blood vessels.
Abstract: The vesiculo-vacuolar organelle (VVO) is a recently described organelle found in the cytoplasm of endothelial cells that line tumor microvessels and normal venules. VVOs are grape-like clusters of interconnecting uncoated vesicles and vacuoles, bounded by trilaminar unit membranes, that span the entire thickness of vascular endothelium, thereby providing a potential trans-endothelial connection between the vascular lumen and the extravascular space. Macromolecular tracers preferentially cross hyperpermeable tumor microvessels through VVOs. The present investigation was undertaken to elucidate further the ultrastructure and function of VVOs in a murine ovarian carcinoma (MOT) and in normal venules. Morphometry revealed that VVOs were enormous cytoplasmic structures (median area, 0.12-0.14 microns2 in single electron micrographs). Moreover, the individual vesicles and vacuoles that comprised VVOs were on average substantially larger than capillary caveolae and followed a non-normal distribution that was skewed to the right. Specimen tilting provided conclusive evidence that individual VVO vesicles and vacuoles communicated with each other and with the endothelial cells' plasma membranes by stomata, some of which were closed by diaphragms composed of a single membrane. Studies with two tracers, ferritin (FE, diameter approximately 11 nm) and horseradish peroxidase (HRP, diameter approximately 5 nm), revealed that passage of macromolecules through VVOs was regulated at the level of stomatal diaphragms, thereby demonstrating a mechanism for controlling the passage of macromolecules across endothelial cells. Thus, compared with tumor microvessels, little circulating FE and HRP entered the VVOs of normal venular endothelium because stomata joining vesicles and vacuoles to each other and to the lumen and ablumen were closed. VVOs and their component vesicles/vacuoles were readily distinguished from endosomal organelles such as coated vesicles and multivesicular bodies, which also accumulated FE and HRP. Our findings indicate that VVOs provide a major pathway for the extravasation of circulating macromolecules across endothelia taller than capillary endothelium and suggest that upregulated VVO function accounts for the well-known hyperpermeability of tumor blood vessels.
TL;DR: In this paper, the authors give new definitions of paracontractions based on Df (x,y), and study sequential and simultaneous iterative algorithms employing them for the solution of the problem of finding a common asymptotic fixed point of a family of operators.
Abstract: A generalized “measure of distance” defined by . is generated from any member f of the class of Bregman functions. Although it is not. technically speaking. a distance function. it has been used in the past to define and study projection operators. In this paper we give new definitions of paracont ractions. convex combinations. and firmly nonexpansivc operators. based on Df (x,y), and study sequential and simultaneous iterative algorithms employing them for the solution of the problem of finding a common asymptotic fixed point of a family of operators. Applications to the convex feasibility problem. to optimization and to monotone operator theory are also included.
TL;DR: This paper describes an optimization-based algorithm for reconstructing a 3D model from a single, inaccurate, 2D edge-vertex graph, which serves as input for the reconstruction process, and examples from a working implementation are given.
Abstract: This paper describes an optimization-based algorithm for reconstructing a 3D model from a single, inaccurate, 2D edge-vertex graph. The graph, which serves as input for the reconstruction process, is obtained from an inaccurate freehand sketch of a 3D wireframe object. Compared with traditional reconstruction methods based on line labelling, the proposed approach is more tolerant of faults in handling both inaccurate vertex positioning and sketches with missing entities. Furthermore, the proposed reconstruction method supports a wide scope of general (manifold and non-manifold) objects containing flat and cylindrical faces. Sketches of wireframe models usually include enough information to reconstruct the complete body. The optimization algorithm is discussed, and examples from a working implementation are given.
TL;DR: It is shown that a similarity network can always answer any query of the form: “What is the posterior probability of an hypothesis given evidence?” and is called diagnostic completeIZESS.
TL;DR: Out preliminary data suggest a possible significant protective effect of GnRHa co-treatment with chemotherapy from irreversible ovarian damage (POF), as well as a matched control group of 18 women (aged 17-40 years) who have been treated with chemotherapy.
Abstract: To examine whether the concomitant administration of a gonadotrophin-releasing hormone agonist (GnRHa) during combination chemotherapy to young women with lymphoma may facilitate preservation of gonadal function, a prospective clinical protocol was undertaken in 18 cycling women with lymphoma, aged 15-40 years. Thirteen patients suffered from Hodgkin disease (HD) and 5 from non-Hodgkin lymphoma. After informed consent a monthly injection of depot D-TRP6-GnRHa was administered for a maximum of 6 months starting prior to chemotherapy. Most of these patients (15/18) were treated with the MOPP/ABV(D) combination chemotherapy followed by mantle field irradiation in 10 patients. Hormonal profile [luteinizing hormone (LH), follicle stimulating hormone (FSH), oestradiol, testosterone, progesterone, insulin-like growth factor (IGF)-1, prolactin] was taken before the GnRHa/chemotherapy co-treatment, and monthly thereafter until resuming spontaneous ovulation and menses. This group of prospectively treated lymphoma patients was compared to a matched control group of 18 women (aged 17-40 years) who have been treated with chemotherapy, mostly MOPP/ABV (14/18), with (11) or without (7) mantle field radiotherapy. Fourteen had Hodgkin's and four non-Hodgkin's lymphoma. Gonadal function was determined clinically, hormonally (LH, FSH, oestradiol, progesterone), and sonographically. Two of the patients in each group died from refractory disease. Of the remaining 16 patients, 15 (93.7%) resumed spontaneous ovulation and menses within 3-8 months of termination of the combined chemotherapy/GnRHa co-treatment. In contrast, only seven (39%) of the 18 similarly treated patients in the control group (chemotherapy without GnRHa) resumed ovarian cyclic activity (regular menses). The other 11 experienced premature ovarian failure (POF) (61%). Out preliminary data suggest a possible significant protective effect of GnRHa co-treatment with chemotherapy from irreversible ovarian damage (POF).
TL;DR: The AMP device achieved substantial success in most cases, but was less effective than CPAP, especially for the more severe cases.
TL;DR: By using a mean field approach, based on the Popov approximation, the temperature dependence of the condensate fraction of an interacting Bose gas confined in an anisotropic harmonic trap is calculated.
Abstract: By using a mean-field approach, based on the Popov approximation, we calculate the temperature dependence of the condensate fraction of an interacting Bose gas of N atoms confined in an anisotropic harmonic trap. For systems interacting with repulsive forces we find a significant decrease of the condensate fraction and of the critical temperature with respect to the predictions of the noninteracting model with the same value of N. An analytic result for the shift of the critical temperature holding to first order in the scattering length is also derived. \textcopyright{} 1996 The American Physical Society.
TL;DR: The electrical resistivity and morphology of polypropylene/nylon (PP/Ny) immiscible blends incorporated with carbon black (CB) were studied in this article, where CB was preferentially located in the Ny phase or upon the Ny/PP interface.
Abstract: The electrical resistivity and morphology of polypropylene/nylon (PP/Ny) immiscible blends incorporated with carbon black (CB) were studied. CB was found to be preferentially located in the Ny phase or upon the Ny/PP interface. Blends with a co-continuous phase morphology depicted especially low resistivity values, due to a “double percolation” effect. The blend preparation sequence tends to affect the phase morphology, thus influencing the system's resistivity. Polymer polarity and crystallinity are important factors determining the blend's morphology, which relates directly to the electrical resistivity obtained.
TL;DR: This report describes the first study of a population (32 couples) of infertile fathers and their sons born after ICSI to determine the incidence and map location of Y chromosome microdeletions and to compare the frequencies with other population studies involving severe male factor infertility, and to formulate a working hypothesis concerning developmental aetiology.
Abstract: Microdeletions linked to deletion intervals 5 and 6 of the Y chromosome have been associated with male factor infertility. Members from at least two gene families lie in the region containing azoospermia factor (AZF), namely YRRM and DAZ. With the advent of intracytoplasmic sperm injection (ICSI), it is possible for men with severe male factor infertility to produce a child. The genetic consequences of such a procedure have been questioned. This report describes the first study of a population (32 couples) of infertile fathers and their sons born after ICSI. The objectives were firstly to determine the incidence and map location of Y chromosome microdeletions and to compare the frequencies with other population studies involving severe male factor infertility, and secondly to formulate a working hypothesis concerning developmental aetiology of Y chromosome microdeletions. The incidence of microdeletions in the ICSI population was shown to be 9.4% (within the range 9-18% reported for populations of severe male factor infertility patients). Microdeletions in two out of three affected father/son pairs mapped in the region between AZFb and AZFc and the third involved a large microdeletion in AZFb and AZFc. Of three affected father/son pairs, microdeletions were detected in the blood of one infertile propositus father and three babies. Assuming that the gonomes of the ICSI-derived babies are direct reflections of those of their fathers germ lines, it is possible that two of three infertile fathers were mosaic for intact Y and microdeleted Y chromosomes. In such cases, the developmental aetiology of the microdeletion may be due to a de-novo microdeletion arising as a post-zygotic mitotic error in the infertile propositus father, thus producing a mosaic individual who may or may not transmit the deletion to his ICSI-derived sons depending on the extent of primordial germ cell mosaicism. In one of three affected fathers, the microdeletion detected in his blood was also detected in his ICSI-derived son. In this case the de-novo event giving rise to the microdeletion may have occurred due to a post- (or pre-) meiotic error in the germ line of this father's normally fertile father (i.e. the ICSI-derived baby's grandfather).