TY - JOUR AB - An ultra-low dose (10-14 M) of opioid peptide [D-Ala2]methionine enkephalinamide (DAMEA) is found to exert an inhibitory effect on the production of reactive oxygen species (respiratory burst) in human neutrophils. The validity of this phenomenon has been verified in a series of studies that comprised 30 experiments. The inhibition has proved to be statistically significant (P<0.001). The dose-response dependence of the effect (10-15-10-9 M) followed a characteristic biphasic pattern (with the maximum effect at ultra-low doses). An opioid antagonist, naloxone partially blocks the inhibitory effect, which indicates that the DAMEA action is at least partially mediated by opioid receptors. AU - Zaǐtsev, Sergei AU - Sazanov, Leonid A AU - Koshkin, Aleksei AU - Sud'Ina, Galina AU - Varfolomeev, Sergei ID - 1946 IS - 1 JF - FEBS Letters SN - 0014-2956 TI - Respiratory burst inhibition in human neutrophils by ultra-low doses of [D-Ala2] methionine enkephalinamide VL - 291 ER - TY - JOUR AB - A complementary DNA encoding the rat NMDA receptor has been cloned and characterized. The single protein encoded by the cDNA forms a receptor-channel complex that has electrophysiological and pharmacological properties characteristic of the NMDA receptor. This protein has a significant sequence similarity to the AMPA/kainate receptors and contains four putative transmembrane segments following a large extracellular domain. The NMDA receptor messenger RNA is expressed in neuronal cells throughout the brain regions, particularly in the hippocampus, cerebral cortex and cerebellum. AU - Moriyoshi, Koki AU - Masu, Masayuki AU - Ishii, Takahiro AU - Shigemoto, Ryuichi AU - Mizuno, Noboru AU - Nakanishi, Shigetada ID - 2483 IS - 6348 JF - Nature SN - 0028-0836 TI - Molecular cloning and characterization of the rat NMDA receptor VL - 353 ER - TY - JOUR AB - The complementary DNA of a metabotropic glutamate receptor coupled to inositol phosphate/Ca2+ signal transduction has been cloned and characterized. This receptor shows no sequence similarity to conventional G protein-coupled receptors and has a unique structure with large hydrophilic sequences at both sides of seven putative membrane-spanning domains. Abundant expression of this messenger RNA is observed in neuronal cells in hippocampal dentate gyrus and CA2-3 and in cerebellar Purkinje cells, suggesting the importance of this receptor in specific hippocampal and cerebellar functions. AU - Masu, Masayuki AU - Tanabe, Yasuto AU - Tsuchida, Kunihiro AU - Shigemoto, Ryuichi AU - Nakanishi, Shigetada ID - 2482 IS - 6312 JF - Nature SN - 0028-0836 TI - Sequence and expression of a metabotropic glutamate receptor VL - 349 ER - TY - JOUR AB - The distribution of cerebral cortical neurons sending projection fibers to the nucleus of the solitary tract (NST), and the topographical distribution of axon terminals of cortico-NST fibers within the NST were examined in the cat by two sets of experiments with horseradish peroxidase (HRP) and HRP conjugated with wheat germ agglutinin (WGA-HRP). First, HRP was injected into the NST. In the cerebral cortex of these cats, neuronal cell bodies were labeled retrogradely in the deep pyramidal cell layer (layer V): After HRP injection centered on the rostral or middle part of the NST, HRP-labeled neuronal cell bodies were distributed mainly in the orbital gyrus and caudal part of the intralimbic cortex, and additionally in the rostral part of the anterior sylvian gyrus. After HRP injection centered on the caudal part of the NST, labeled neuronal cell bodies were seen mainly in the caudoventral part of the intralimbic cortex, and additionally in the orbital gyrus, posterior sigmoid gyrus and rostral part of the anterior sylvian gyrus. The labeling in the intralimbic cortex, orbital gyrus and anterior sylvian gyrus was bilateral with a predominantly ipsilateral distribution, while that in the posterior sigmoid gyrus was bilateral with a clear-cut contralateral dominance. In the second set of experiments, WGA-HRP was injected into the cerebral cortical regions where neuronal cell bodies had been retrogradely labeled with HRP injected into the NST: after WGA-HRP injection into the orbital gyrus, presumed axon terminals in the NST were labeled in the rostral two thirds of the nucleus bilaterally with an ipsilateral predominance. After WGA-HRP injection into the rostral part of the anterior sylvian gyrus, a moderate number of presumed axon terminals were labeled throughout the whole rostrocaudal extent of the NST bilaterally with a slight ipsilateral dominance. After WGA-HRP injection into the middle and caudal parts of the anterior sylvian gyrus, no labeling was found in the NST. After WGA-HRP injection into the caudal part of the intralimbic cortex, presumed terminal labeling in the NST was seen throughout the whole rostrocaudal extent of the nucleus bilaterally with a dominant ipsilateral distribution. After WGA-HRP injection into the posterior sigmoid gyrus, however, no terminal labeling was found in the NST. The results indicate that cortico-NST fibers from the orbital gyrus terminate in the rostral two thirds of the NST, while those from the intralimbic cortex and the rostral part of the anterior sylvian gyrus project to the whole rostrocaudal extent of the NST. AU - Yasui, Yukihiko AU - Itoh, Kazuo AU - Kaneko, Takeshi AU - Shigemoto, Ryuichi AU - Mizuno, Noboru ID - 2529 IS - 1 JF - Experimental Brain Research SN - 0014-4819 TI - Topographical projections from the cerebral cortex to the nucleus of the solitary tract in the cat VL - 85 ER - TY - CHAP AU - Nakanishi, Shigetada AU - Ohkubo, Hiroaki AU - Kakizuka, Akira AU - Yokota, Yoshifumi AU - Shigemoto, Ryuichi AU - Sasai, Yoshiki AU - Takumi, Toru ID - 2530 SN - 978-0-12-571148-7 T2 - Recent Progress in Hormone Research TI - Molecular characterization of mammalian tachykinin receptors and a possible epithelial potassium channel VL - 46 ER - TY - CHAP AB - This paper proves an O(m2/3n2/3 + m + n) upper bound on the number of incidences between m points and n hyperplanes in four dimensions, assuming all points lie on one side of each hyperplane and the points and hyperplanes satisfy certain natural general position conditions. This result has application to various three-dimensional combinatorial distance problems. For example, it implies the same upper bound for the number of bichromatic minimum distance pairs in a set of m blue and n red points in three-dimensional space. This improves the best previous bound for this problem. © Springer-Verlag Berlin Heidelberg 1990. AU - Edelsbrunner, Herbert AU - Sharir, Micha ID - 3566 SN - 978-0897913850 T2 - Applied Geometry and Discrete Mathematics: The Victor Klee Festschrift TI - A hyperplane incidence problem with applications to counting distances VL - 4 ER - TY - CHAP AB - Many computational geometry problems arc exceedingly more difficult if the setting is the (three-dimensional real) space R3 rather than the plane . Most often the reason for this striking increase in complexity is the appearance of new geometric phenomena caused by one-dimensional objects in space. The intention of recent studies on problems for lines in space is to shed light on these new phenomena and their complexities. This paper reviews some of the most important results and shows how they are related to problems in dimensions 2 and 5. AU - Edelsbrunner, Herbert ID - 3567 SN - 9780821865958 T2 - Discrete & Computational Geometry: Papers from the Dimacs Special Year TI - Lines in space – A collection of results VL - 6 ER - TY - JOUR AB - This paper describes an effective procedure for stratifying a real semi-algebraic set into cells of constant description size. The attractive feature of our method is that the number of cells produced is singly exponential in the number of input variables. This compares favorably with the doubly exponential size of Collins' decomposition. Unlike Collins' construction, however, our scheme does not produce a cell complex but only a smooth stratification. Nevertheless, we are able to apply our results in interesting ways to problems of point location and geometric optimization. AU - Chazelle, Bernard AU - Edelsbrunner, Herbert AU - Guibas, Leonidas AU - Sharir, Micha ID - 4052 IS - 1 JF - Theoretical Computer Science SN - 0304-3975 TI - A singly exponential stratification scheme for real semi-algebraic varieties and its applications VL - 84 ER - TY - JOUR AB - This paper proves that for every n ≥ 4 there is a convex n-gon such that the vertices of 2n - 7 vertex pairs are one unit of distance apart. This improves the previously best lower bound of ⌊ (5n - 5) 3⌋ given by Erdo{combining double acute accent}s and Moser if n ≥ 17. AU - Edelsbrunner, Herbert AU - Hajnal, Péter ID - 4056 IS - 2 JF - Journal of Combinatorial Theory Series A SN - 0097-3165 TI - A lower bound on the number of unit distances between the vertices of a convex polygon VL - 56 ER - TY - CONF AB - The zone theorem for an arrangement of n hyperplanes in d-dimensional real space says that the total number of faces bounding the cells intersected by another hyperplane is O(n d–1). This result is the basis of a time-optimal incremental algorithm that constructs a hyperplane arrangement and has a host of other algorithmic and combinatorial applications. Unfortunately, the original proof of the zone theorem, for d ge 3, turned out to contain a serious and irreparable error. This paper presents a new proof of the theorem. Our proof is based on an inductive argument, which also applies in the case of pseudo-hyperplane arrangements. We also briefly discuss the fallacies of the old proof along with some ways of partially saving that approach. AU - Edelsbrunner, Herbert AU - Seidel, Raimund AU - Sharir, Micha ID - 4054 TI - On the zone theorem for hyperplane arrangements VL - 555 ER - TY - CONF AB - We present a randomized incremental algorithm for computing a single face in an arrangement of n line segments in the plane that is fairly simple to implement. The expected running time of the algorithm is O (nα(n) log n). The analysis of the algorithm uses a novel approach that generalizes and extends the Clarkson-Shor analysis technique. AU - Chazelle, Bernard AU - Edelsbrunner, Herbert AU - Guibas, Leonidas AU - Sharir, Micha AU - Snoeyink, Jack ID - 4058 SN - 978-0-89791-376-8 T2 - Proceedings of the 2nd annual ACM-SIAM symposium on Discrete algorithms TI - Computing a face in an arrangement of line segments ER - TY - CONF AB - It is shown that a triangulation of a set of n points in the plane that minimizes the maximum edge length can be computed in time O(n2). The algorithm is reasonably easy to implement and is based on the theorem that there is a triangulation with minmax edge length that contains the relative neighborhood graph of the points as a subgraph. With minor modifications the algorithm works for arbitrary normed metrics. AU - Edelsbrunner, Herbert AU - Tan, Tiow ID - 4055 T2 - 32nd Annual Symposium of Foundations of Computer Science TI - A quadratic time algorithm for the minmax length triangulation ER - TY - JOUR AB - An algorithm is presented that constructs the convex hull of a set of n points in three dimensions in worst-case time O(n log2h) and storage O(n), where h is the number of extreme points. This is an improvement of the O(nh) time gift-wrapping algorithm and, for certain values of h, of the O(n log n) time divide-and-conquer algorithm. AU - Edelsbrunner, Herbert AU - Shi, Weiping ID - 4051 IS - 2 JF - SIAM Journal on Computing SN - 0097-5397 TI - An O(n log^2 h) time algorithm for the three-dimensional convex hull problem VL - 20 ER - TY - JOUR AU - Edelsbrunner, Herbert ID - 4057 IS - 2 JF - Journal of Computer and System Sciences SN - 0022-0000 TI - Corrigendum VL - 42 ER - TY - JOUR AB - Two types of metabolically regulated K channels have been identified for the first time in enzymatically demyelinated fibres of amphibian sciatic nerve using the patch-clamp technique. A maxi K channel with a single-channel conductance of 132 pS (105 mM K on both sides of the membrane, 15°C) is activated both by micromolar concentrations of internal Ca and by depolarization. A second type of K channel with a conductance of 44 pS is inhibited by intracellular adenosine 5'-triphosphate (ATP) with a half-maximal inhibitory concentration (IC50) of 35 μM. It is blocked by submicromolar concentrations of external glibenclamide. Both channels are sensitive to external tetraethylammonium chloride (IC50 = 0.2 mM for the maxi K channel and 4.2 mM for the ATP-sensitive channel). They may be part of a complex feedback system regulating axonal excitability under various metabolic conditions. AU - Jonas, Peter M AU - Koh, Duk AU - Kampe, Knut AU - Hermsteiner, Markus AU - Vogel, Werner ID - 3468 IS - 1-2 JF - Pflügers Archiv : European Journal of Physiology SN - 0031-6768 TI - ATP-sensitive and Ca-activated K channels in vertebrate axons: novel links between metabolism and excitability VL - 418 ER - TY - JOUR AB - We compare the pattern of morphological and electrophoretic variation in the hybrid zone between Bombina bombina and B. variegata across two transects: one near Cracow and one 200 km away, near Przemysl in southeastern Poland. Morphological variation across the Przemysl transect had been surveyed more than 50 years ago; though we found a significant shift at one site, there is no evidence for gross movement over this period. Morphological and electrophoretic changes coincide, and the average shape of the clines is the same across both transects. At the center, most of the change in frequency of six diagnostic allozymes occurs within w = 6.05 km (2-unit support limits 5.56-6.54 km). These steep gradients are generated not by selection on the allozymes themselves, but by associations with other loci: though these markers are unlinked, they are in strong linkage disequilibrium with each other [R = D/ = 0.22 (0.15-0.29) at the center]. Disequilibria are broken up as alleles diffuse away from the zone and flow into the new genetic background. The net barrier to the flow of genes from bombina into variegata, which is generated by these disequilibria, is B = 51 (22-81) km. The fitness of hybrids must be substantially reduced to produce such a barrier [W̄H/W̄P = 0.58 (0.54-0.68)], and this selection must be spread over many loci [N = 55 (26-88)]. Alleles introgress significantly less far than would be expected from the age of the zone and the estimated dispersal rate [σ = 0.99 (0.82-1.14) km gen.-1/2]: this implies selection of se = 0.37 (0.15-0.58)% on the enzymes themselves. There is weak but significant linkage disequilibrium well away from the center of the zone; this, together with the presence of parental and F1 genotypes, suggests some long-range migration. However, such migration is not likely to cause significant introgression. AU - Szymura, Jacek AU - Barton, Nicholas H ID - 3646 IS - 2 JF - Evolution SN - 0014-3820 TI - The genetic structure of the hybrid zone between the fire-bellied toads Bombina bombina and B. variegata: comparisons between transects and between loci VL - 45 ER - TY - JOUR AB - A method is developed that describes the effects on an arbitrary number of autosomal loci of selection on haploid and diploid stages, of nonrandom mating between haploid individuals, and of recombination. We provide exact recursions for the dynamics of allele frequencies and linkage disequilibria (nonrandom associations of alleles across loci). When selection is weak relative to recombination, our recursions provide simple approximations for the linkage disequilibria among arbitrary combinations of loci. We show how previous models of sex-independent natural selection on diploids, assortative mating between haploids, and sexual selection on haploids can be analyzed in this framework. Using our weak-selection approximations, we derive new results concerning the coevolution of male traits and female preferences under natural and sexual selection. In particular, we provide general expressions for the intensity of linkage-disequilibrium induced selection experienced by loci that contribute to female preferences for specific male traits. Our general results support the previous observation that these indirect selection forces are so weak that they are unlikely to dominate the evolution of preference-producing loci. AU - Barton, Nicholas H AU - Turelli, Michael ID - 3647 IS - 1 JF - Genetics SN - 0016-6731 TI - Natural and sexual selection on many loci VL - 127 ER - TY - JOUR AB - We investigate the probability of fixation of a chromosome rearrangement in a subdivided population, concentrating on the limit where migration is so large relative to selection (m ≫ s) that the population can be thought of as being continuously distributed. We study two demes, and one- and two-dimensional populations. For two demes, the probability of fixation in the limit of high migration approximates that of a population with twice the size of a single deme: migration therefore greatly reduces the fixation probability. However, this behavior does not extend to a large array of demes. Then, the fixation probability depends primarily on neighborhood size (Nb), and may be appreciable even with strong selection and free gene flow (≈exp(-B·Nb) in one dimension, ≈exp(-B\cdotNb) in two dimensions). Our results are close to those for the more tractable case of a polygenic character under disruptive selection. AU - Barton, Nicholas H AU - Rouhani, Shahin ID - 3648 IS - 3 JF - Evolution SN - 0014-3820 TI - The probability of fixation of a new karyotype in a continuous population VL - 45 ER - TY - CONF AB - Let P be a simple polygon with n vertices. We present a simple decomposition scheme that partitions the interior of P into O(n) so-called geodesic triangles, so that any line segment interior to P crosses at most 2 log n of these triangles. This decomposition can be used to preprocess P in time O(n log n) and storage O(n), so that any ray-shooting query can be answered in time O(log n).The algorithms are fairly simple and easy to implement. We also extend this technique to the case of ray-shooting amidst k polygonal obstacles with a total of n edges, so that a query can be answered in O(radicklog n) time. AU - Chazelle, Bernard AU - Edelsbrunner, Herbert AU - Grigni, Michelangelo AU - Guibas, Leonidas AU - Hershberger, John AU - Sharir, Micha AU - Snoeyink, Jack ID - 4059 T2 - 18th International Colloquium on Automata, Languages and Programming TI - Ray shooting in polygons using geodesic triangulations VL - 510 ER - TY - JOUR AB - We present an algorithm to compute a Euclidean minimum spanning tree of a given set S of N points in Ed in time O(Fd (N,N) logd N), where Fd (n,m) is the time required to compute a bichromatic closest pair among n red and m green points in Ed . If Fd (N,N)=Ω(N1+ε), for some fixed e{open}>0, then the running time improves to O(Fd (N,N)). Furthermore, we describe a randomized algorithm to compute a bichromatic closest pair in expected time O((nm log n log m)2/3+m log2 n+n log2 m) in E3, which yields an O(N4/3 log4/3 N) expected time, algorithm for computing a Euclidean minimum spanning tree of N points in E3. In d≥4 dimensions we obtain expected time O((nm)1-1/([d/2]+1)+ε+m log n+n log m) for the bichromatic closest pair problem and O(N2-2/([d/2]+1)ε) for the Euclidean minimum spanning tree problem, for any positive e{open}. AU - Agarwal, Pankaj AU - Edelsbrunner, Herbert AU - Schwarzkopf, Otfried AU - Welzl, Emo ID - 4061 IS - 1 JF - Discrete & Computational Geometry SN - 0179-5376 TI - Euclidean minimum spanning trees and bichromatic closest pairs VL - 6 ER - TY - JOUR AB - We prove that for any set S of n points in the plane and n3-α triangles spanned by the points in S there exists a point (not necessarily in S) contained in at least n3-3α/(c log5 n) of the triangles. This implies that any set of n points in three-dimensional space defines at most {Mathematical expression} halving planes. AU - Aronov, Boris AU - Chazelle, Bernard AU - Edelsbrunner, Herbert AU - Guibas, Leonidas AU - Sharir, Micha AU - Wenger, Rephael ID - 4062 IS - 1 JF - Discrete & Computational Geometry SN - 0179-5376 TI - Points and triangles in the plane and halving planes in space VL - 6 ER - TY - CONF AB - We extend the specification language of temporal logic, the corresponding verification framework, and the underlying computational model to deal with real-time properties of concurrent and reactive systems. A global, discrete, and asynchronous clock is incorporated into the model by defining the abstract notion of a real-time transition system as a conservative extension of traditional transition systems: qualitative fairness requirements are replaced (and superseded) by quantitative lower-bound and upperbound real-time requirements for transitions. We show how to model real-time systems that communicate either through shared variables or by message passing, and how to represent the important real-time constructs of priorities (interrupts), scheduling, and timeouts in this framework. Two styles for the specification of real-time properties are presented. The first style uses bounded versions of the temporal operators; the real-time requirements expressed in this style are classified ... AU - Henzinger, Thomas A AU - Manna, Zohar AU - Pnueli, Amir ID - 4508 SN - 978-0-89791-419-2 T2 - Proceedings of the 18th ACM SIGPLAN-SIGACT symposium on Principles of programming languages TI - Temporal proof methodologies for real-time systems ER - TY - THES AB - We extend the specification language of temporal logic, the corresponding verification framework, and the underlying computational model to deal with real-time properties of reactive systems. Semantics We introduce the abstract computational model of timed transition systems as a conservative extension of traditional transition systems qualitative fairness requirements are superseded by quantitative real-time constraints on the transitions. Digital clocks are introduced as observers of continuous real-time behavior. We justify our semantical abstractions by demonstrating that a wide variety of concrete real-time systems can be modeled adequately. Specification We present two conservative extensions of temporal logic that allow for the specification of timing constraints while timed temporal logic provides access to time through a novel kind of time quantifier, metric temporal logic refers to time through time-bounded versions of the temporal operators. We justify our choice of specification languages by developing a general framework for the classification of real-time logics according to their complexity and expressive power. Verification We develop tools for determining if a real-time system that is modeled as a timed transition system meets a specification that is given in timed temporal logic or in metric temporal logic. We present both model-checking algorithms for the automatic verification of finite-state real-time systems and proof methods for the deductive verification of real-time systems. AU - Henzinger, Thomas A ID - 4516 TI - The temporal specification and verification of real-time systems ER - TY - JOUR AU - Alur, Rajeev AU - Henzinger, Thomas A ID - 4592 IS - 3 JF - SIGACT News SN - 0163-5700 TI - Time for logic VL - 22 ER - TY - CONF AB - The most natural, compositional, way of modeling real-time systems uses a dense domain for time. The satisfiability of timing constraints that are capable of expressing punctuality in this model, however, is known to be undecidable. We introduce a temporal language that can constrain the time difference between events only with finite, yet arbitrary, precision and show the resulting logic to be EXPSPACE-complete. This result allows us to develop an algorithm for the verification of timing properties of real-time systems with a dense semantics. AU - Alur, Rajeev AU - Feder, Tomás AU - Henzinger, Thomas A ID - 4621 SN - 978-0-89791-439-0 T2 - Proceedings of the 10th Annual ACM Symposium on Principles of Distributed Computing TI - The benefits of relaxing punctuality ER -