@inproceedings{4522, abstract = {We introduce a novel extension of propositional modal logic that is interpreted over Kripke structures in which a value is associated with every possible world. These values are. however, not treated as full first-order objects: they can be accessed only by a very restricted form of quantification: the "freeze" quantifier binds a variable to the value of the current world. We present a complete proof system for this ("half-order") modal logic. As a special case, we obtain the real-time temporal logic TPTL of [AH891: the models are restricted to infinite sequences of states, whose values are monotonically increasing natural numbers. The ordering relation between states is interpreted as temporal precedence. while the value associated with a state is interpreted as its "rear time. We extend our proof system to be complete for TPTL. and demonstrate how it can be used to derive real-time properties. }, author = {Henzinger, Thomas A}, booktitle = {Proceedings of the 9th annual ACM symposium on Principles of distributed computing}, isbn = {978-0-89791-404-8}, location = {Quebec City, Canada}, pages = {281 -- 296}, publisher = {ACM}, title = {{Half-order modal logic: How to prove real-time properties}}, doi = {10.1145/93385.93429}, year = {1990}, } @inproceedings{4597, abstract = {A unifying framework for the study of real-time logics is developed. In analogy to the untimed case, the underlying classical theory of timed state sequences is identified, it is shown to be nonelementarily decidable, and its complexity and expressiveness are used as a point of reference. Two orthogonal extensions of PTL (timed propositional temporal logic and metric temporal logic) that inherit its appeal are defined: they capture elementary, yet expressively complete, fragments of the theory of timed state sequences, and thus are excellent candidates for practical real-time specification languages}, author = {Alur, Rajeev and Henzinger, Thomas A}, booktitle = { 5th Annual IEEE Symposium on Logic in Computer Science}, isbn = {0-8186-2073-0}, location = {Philadelphia, PA, USA}, pages = {390 -- 401}, publisher = {IEEE}, title = {{Real-time logics: Complexity and expressiveness}}, doi = {10.1109/LICS.1990.113764}, year = {1990}, } @article{2480, abstract = {Functional cDNA clones for rat neuromedin K receptor were isolated from a rat brain cDNA library by cross-hybridization with the bovine substance K recepor cDNA. Injection of the mRNA synthesized in vitro from the cloned cDNA into Xenopus oocytes elicited electrophysiological responses to tachykinins, with the most potent sensitivity being to neuromedin K. Ligand-binding displacement in membranes of mammalian COS cells transfected with the cDNA indicated the rank order of affinity of the receptor to tachykinins; neuromedin K > substance K > substance P. The hybridization analysis showed that the neuromedin K receptor mRNA is expressed in both the brain and the peripheral tissues at different levels. The rat neuromedin K receptor consists of 452 amino acid residues and belongs to the family of G protein-coupled receptors, which are thought to have seven transmembrane domains. The sequence comparison of the rat neuromedin K, substance P, and substance K receptors revealed that these receptors are highly conserved in the seven transmembrane domains and the cytoplasmic sides of the receptors. They also show some structural characteristics, including the common presence of histidine residues in transmembrane segments V and VI and the difference in the numbers and distributions of serine and threonine residues as possible phosphorylation sites in the cytoplasmic regions. This paper thus presents the first comprehensive analysis of the molecular nature of the multiple peptide receptors that exhibit similar but pharmacologically distinguishable activities.}, author = {Shigemoto, Ryuichi and Yokota, Yoshifumi and Tsuchida, Kunihiro and Nakanishi, Shigetada}, issn = {1083-351X}, journal = {Journal of Biological Chemistry}, number = {2}, pages = {623 -- 628}, publisher = {American Society for Biochemistry and Molecular Biology}, title = {{Cloning and expression of a rat neuromedin K receptor cDNA}}, doi = {10.1016/s0021-9258(19)40095-1 }, volume = {265}, year = {1990}, } @article{2481, abstract = {The family of mammalian tachykinin receptors consists of substance P receptor (SPR), neuromedin K receptor (NKR) and substance K receptor (SKR). In this investigation, tissue and regional distributions of the mRNAs for the three rat tachykinin receptors were investigated by blot-hybridization and RNase-protection analyses using the previously cloned receptor cDNAs. SPR mRNA is widely distributed in both the nervous system and peripheral tissues and is expressed abundantly in the hypothalamus and olfactory buld, as well as in the urinary bladder, salivary glands and small and large intestines. In contrast, NKR mRNA is predominantly expressed in the nervous system, particularly in the cortex, hypothalamus and cerebellum, whereas SKR mRNA expression is restricted to the peripheral tissues, being abundant in the urinary bladder, large intestine, stomach and adenal glands. Thus, the mRNAs for the three tachykinin receptors show distinct patterns of expression between the nervous system and peripheral tissues. Blot-hybridization analysis in combination with S1 nuclease protection and primer-extension analyses revealed that there are two large forms of SKR mRNA expressed commonly in the peripheral tissues, and two additional small forms of the mRNA expressed specifically in the adrenal gland and eye. These analyses also showed that the multiple forms of SKR mRNA differ in the lengths of the 5' mRNA portions, and that the two small forms of the mRNA, if translated, encode a truncated SKR polypeptide lacking the first two transmembrane domains. This investigation thus provides the comprehensive analysis of the distribution and mode of expression of the mRNAs for the multiple peptide receptors and offers a new basis on which to interpret the diverse functions of multiple tachykinin peptides in the CNS and peripheral tissues.}, author = {Tsuchida, Kunihiro and Shigemoto, Ryuichi and Yokota, Yoshifumi and Nakanishi, Shigetada}, issn = {1432-1033}, journal = {European Journal of Biochemistry}, number = {3}, pages = {751 -- 757}, publisher = {Wiley-Blackwell}, title = {{Tissue distribution and quantitation of the mRNAs for three rat tachykinin receptors}}, doi = {10.1111/j.1432-1033.1990.tb19396.x}, volume = {193}, year = {1990}, } @article{2528, abstract = {We previously reported a novel rat membrane protein that exhibits a voltage-dependent potassium channel activity on the basis of molecular cloning combined with an electrophysiological assay. This protein, termed I(sK) protein, is small and different from the conventional potassium channel proteins but induces selective permeation of potassium ions on its expression in Xenopus oocytes. In this investigation, we examined cellular localization of rat I(sK) protein by preparing three different types of antibody that specifically reacts with a distinct part of rat I(sK) protein. Immunohistochemical analysis using these antibody preparations demonstrated that rat I(sK) protein is confined to the apical membrane portion of epithelial cells in the proximal tubule of the kidney, the submandibular duct and the uterine endometrium. The observed tissue distribution of rat I(sK) protein was consistent with that of the I(sK) protein mRNA determined by blot hybridization analysis. In epithelial cells, the sodium, potassium-ATPase pump in the basolateral membrane generates a sodium gradient across the epithelial cell and allows sodium ions to enter the cell through the apical membrane. Thus, taking into account the cellular localization of the I(sK) protein, together with its electrophysiological properties, we discussed a possible function of the I(sK) protein, namely that this protein is involved in potassium permeation in the apical membrane of epithelial cells through the depolarizing effect of sodium entry.}, author = {Sugimoto, Tetsuo and Tanabe, Yasuto and Shigemoto, Ryuichi and Iwai, Masazumi and Takumi, Toru and Ohkubo, Hiroaki and Nakanishi, Shigetada}, issn = {1432-1424}, journal = {Journal of Membrane Biology}, number = {1}, pages = {39 -- 47}, publisher = {Springer}, title = {{Immunohistochemical study of a rat membrane protein which induces a selective potassium permeation: Its localization in the apical membrane portion of epithelial cells}}, doi = {10.1007/BF01869604}, volume = {113}, year = {1990}, } @article{2721, abstract = {We consider a multidimensional system consisting of a particle of mass M and radius r (molecule), surrounded by an infinite ideal gas of point particles of mass m (atoms). The molecule is confined to the unit ball and interacts with its boundary (barrier) via elastic collision, while the atoms are not affected by the boundary. We obtain convergence to equilibrium for the molecule from almost every initial distribution on its position and velocity. Furthermore, we prove that the infinite composite system of the molecule and the atoms is Bernoulli.}, author = {Erdös, László and Tuyen, Dao}, issn = {1572-9613}, journal = {Journal of Statistical Physics}, number = {5-6}, pages = {1589 -- 1602}, publisher = {Springer}, title = {{Ergodic properties of the multidimensional rayleigh gas with a semipermeable barrier}}, doi = {10.1007/BF01334766}, volume = {59}, year = {1990}, } @article{3465, abstract = {Asymmetrical displacement currents and Na currents of single myelinated nerve fibers of Xenopus laevis were studied in the temperature range from 5 to 24 degrees C. The time constant of the on-response at E = 4 mV, tau on, was strongly temperature dependent, whereas the amount of displaced charge at E = 39 mV, Qon, was only slightly temperature dependent. The mean Q10 for tau on-1 was 2.54, the mean Q10 for Qon was 1.07. The time constant of charge immobilization, tau i, at E = 4 mV varied significantly (alpha = 0.001) with temperature. The mean Q10 for tau i-1 was 2.71 +/- 0.38. The time constants of immobilization of gating charge and of fast inactivation of Na permeability were similar in the temperature range from 6 to 22 degrees C. The Qoff/Qon ratio for E = 4 mV pulses of 0.5 msec duration decreased with increasing temperature. The temperature dependence of the time constant of the off-response could not be described by a single Q10 value, since the Q10 depended on the duration of the test pulse. Increasing temperature shifted Qon (E) curves to more negative potentials by 0.51 mV K-1, but shifted PNa (E) curves and h infinity (E) curves to more positive potentials by 0.43 and 0.57 mV K-1, respectively. h infinity (E = -70 mV) increased monotonously with increasing temperature. The present data indicate that considerable entropy changes may occur when the Na channel molecule passes from closed through open to inactivated states.}, author = {Jonas, Peter M}, issn = {1432-1424}, journal = {Journal of Membrane Biology}, number = {3}, pages = {277 -- 289}, publisher = {Springer}, title = {{Temperature dependence of gating current in myelinated nerve fibers}}, doi = {10.1007/BF01870958}, volume = {112}, year = {1989}, } @article{3466, abstract = {Amphibian myelinated nerve fibers were treated with collagenase and protease. Axons with retraction of the myelin sheath were patch-clamped in the nodal and paranodal region. One type of Na channel was found. It has a single-channel conductance of 11 pS (15 degrees C) and is blocked by tetrodotoxin. Averaged events show the typical activation and inactivation kinetics of macroscopic Na current. Three potential-dependent K channels were identified (I, F, and S channel). The I channel, being the most frequent type, has a single-channel conductance of 23 pS (inward current, 105 mM K on both sides of the membrane), activates between -60 and -30 mV, deactivates with intermediate kinetics, and is sensitive to dendrotoxin. The F channel has a conductance of 30 pS, activates between -40 and 60 mV, and deactivates with fast kinetics. The former inactivates within tens of seconds; the latter inactivates within seconds. The third type, the S channel, has a conductance of 7 pS and deactivates slowly. All three channels can be blocked by external tetraethylammonium chloride. We suggest that these distinct K channel types form the basis for the different components of macroscopic K current described previously.}, author = {Jonas, Peter M and Bräu, Michael and Hermsteiner, Markus and Vogel, Werner}, issn = {1091-6490}, journal = {PNAS}, number = {18}, pages = {7238 -- 7242}, publisher = {National Academy of Sciences}, title = {{Single-channel recording in myelinated nerve fibers reveals one type of Na channel but different K channels}}, doi = {10.1073/pnas.86.18.7238}, volume = {86}, year = {1989}, } @inproceedings{3549, abstract = {We study three types of spatial triangulations: Delaunay triangulations, triangulations with non-obtuse dihedral angles, and KJ-triangulations. The latter satisfy a certain angle condition useful for finite element approximation. We show that the condition for Delaunay triangulations is incomparable with the other two conditions, and that triangulations with non-obtuse dihedral angles are necessarily also KJ-triangulations. These relationships are in sharp contrast to the ones in the planar case. }, author = {Edelsbrunner, Herbert}, pages = {83 -- 89}, publisher = {Institute of the Electronics, Information and Communication Enginneers}, title = {{Spatial triangulations with dihedral angle conditions}}, year = {1989}, } @article{3652, abstract = {Frequency-dependent selection against rare forms can maintain clines. For weak selection, s, in simple linear models of frequency-dependence, single locus clines are stabilized with a maximum slope of between square root of s/square root of 8 sigma and square root of s/square root of 12 delta, where sigma is the dispersal distance. These clines are similar to those maintained by heterozygote disadvantage. Using computer simulations, the weak-selection analytical results are extended to higher selection pressures with up to three unlinked genes. Graphs are used to display the effect of selection, migration, dominance, and number of loci on cline widths, speeds of cline movements, two-way gametic correlations ("linkage disequilibria"), and heterozygote deficits. The effects of changing the order of reproduction, migration, and selection, are also briefly explored. Epistasis can also maintain tension zones. We show that epistatic selection is similar in its effects to frequency-dependent selection, except that the disequilibria produced in the zone will be higher for a given level of selection. If selection consists of a mixture of frequency-dependence and epistasis, as is likely in nature, the error made in estimating selection is usually less than twofold. From the graphs, selection and migration can be estimated using knowledge of the dominance and number of genes, of gene frequencies and of gametic correlations from a hybrid zone.}, author = {Mallet, James and Barton, Nicholas H}, issn = {0016-6731}, journal = {Genetics}, number = {4}, pages = {967 -- 976}, publisher = {Genetics Society of America}, title = {{Inference from clines stabilized by frequency-dependent selection}}, doi = {10.1093/genetics/122.4.967}, volume = {122}, year = {1989}, } @article{3653, abstract = {Frequency-dependent selection on warning color can maintain narrow hybrid zones between unpalatable prey taxa. To measure such selection, we transferred marked Heliconius erato (Lepidoptera: Nymphalidae) in both directions across a 10-km-wide hybrid zone between Peruvian races differing in color pattern. These experimental H. erato were released at four sites, along with control H. erato of the phenotype native to each site. Survival of experimental butterflies was significantly lower than that of controls at two sites and overall. Most selection, measured as differences in survival, occurred soon after release. Selection against foreign morphs was 52% (confidence limits: 25-71%) and was probably due to bird attacks on unusual warning-color morphs (more than 10% of the recaptures had beak marks). Since only three major loci determine the color-pattern differences, this suggests an average selection coefficient of 0.17 per locus, sufficient to maintain the narrow clines in H. erato.}, author = {Mallet, James and Barton, Nicholas H}, issn = {1558-5646}, journal = {Evolution}, number = {2}, pages = {421 -- 431}, publisher = {Wiley-Blackwell}, title = {{Strong natural selection in a warning color hybrid zone}}, doi = {10.2307/2409217 }, volume = {43}, year = {1989}, } @article{3654, abstract = {Many species are divided into a mosaic of genetically distinct populations, separated by narrow zones of hybridization. Studies of hybrid zones allow us to quantify the genetic differences responsible for speciation, to measure the diffusion of genes between diverging taxa, and to understand the spread of alternative adaptations.}, author = {Barton, Nicholas H and Hewitt, Godfrey}, issn = {1476-4687}, journal = {Nature}, pages = {497 -- 503}, publisher = {Nature Publishing Group}, title = {{Adaptation, speciation and hybrid zones}}, doi = {10.1038/341497a0}, volume = {341}, year = {1989}, } @article{4079, author = {Edelsbrunner, Herbert and Skiena, Steven}, issn = {1930-0972}, journal = {American Mathematical Monthly}, number = {7}, pages = {614 -- 618}, publisher = {Mathematical Association of America}, title = {{On the number of furthest neighbor pairs in a point set}}, doi = {10.1080/00029890.1989.11972250}, volume = {96}, year = {1989}, } @article{4080, abstract = {This paper proves that any set of n points in the plane contains two points such that any circle through those two points encloses at least n12−112+O(1)n47 points of the set. The main ingredients used in the proof of this result are edge counting formulas for k-order Voronoi diagrams and a lower bound on the minimum number of semispaces of size at most k.}, author = {Edelsbrunner, Herbert and Hasan, Nany and Seidel, Raimund and Shen, Xiao}, issn = {1572-9168}, journal = {Geometriae Dedicata}, number = {1}, pages = {1 -- 12}, publisher = {Springer}, title = {{Circles through two points that always enclose many points}}, doi = {10.1007/BF00181432}, volume = {32}, year = {1989}, } @article{4081, abstract = {This paper studies applications of envelopes of piecewise linear functions to problems in computational geometry. Among these applications we find problems involving hidden line/surface elimination, motion planning, transversals of polytopes, and a new type of Voronoi diagram for clusters of points. All results are either combinatorial or computational in nature. They are based on the combinatorial analysis in two companion papers [PS] and [E2] and a divide-and-conquer algorithm for computing envelopes described in this paper.}, author = {Edelsbrunner, Herbert and Guibas, Leonidas and Sharir, Micha}, issn = {1432-0444}, journal = {Discrete & Computational Geometry}, number = {1}, pages = {311 -- 336}, publisher = {Springer}, title = {{The upper envelope of piecewise linear functions: Algorithms and applications}}, doi = {10.1007/BF02187733}, volume = {4}, year = {1989}, } @article{4082, abstract = {Sweeping a collection of figures in the Euclidean plane with a straight line is one of the novel algorithmic paradigms that have emerged in the field of computational geometry. In this paper we demonstrate the advantages of sweeping with a topological line that is not necessarily straight. We show how an arrangement of n lines in the plane can be swept over in O(n2) time and O(n) space by a such a line. In the process each element, i.e., vertex, edge, or region, is visited once in a consistent ordering. Our technique makes use of novel data structures which exhibit interesting amortized complexity behavior; the result is an algorithm that improves upon all its predecessors either in the space or the time bounds, as well as being eminently practical. Numerous applications of the technique to problems in computational geometry are given—many through the use of duality transforms. Examples include solving visibility problems, detecting degeneracies in configurations, computing the extremal shadows of convex polytopes, and others. Even though our basic technique solves a planar problem, its applications include several problems in higher dimensions.}, author = {Edelsbrunner, Herbert and Guibas, Leonidas}, issn = {1090-2724}, journal = {Journal of Computer and System Sciences}, number = {1}, pages = {165 -- 194}, publisher = {Elsevier}, title = {{Topologically sweeping an arrangement}}, doi = {10.1016/0022-0000(89)90038-X}, volume = {38}, year = {1989}, } @article{4083, abstract = {It is shown that, given a set S of n points in $R^3 $, one can always find three planes that form an eight-partition of S, that is, a partition where at most ${n / 8}$ points of S lie in each of the eight open regions. This theorem is used to define a data structure, called an octant tree, for representing any point set in $R^3 $. An octant tree for n points occupies $O(n)$ space and can be constructed in polynomial time. With this data structure and its refinements, efficient solutions to various range query problems in two and three dimensions can be obtained, including (1) half-space queries: find all points of S that lie to one side of any given plane; (2) polyhedron queries: find all points that lie inside (outside) any given polyhedron; and (3) circle queries in $R^2 $: for a planar set S, find all points that lie inside (outside) any given circle. The retrieval time for all these queries is $T(n) = O(n^\alpha + m)$, where $\alpha = 0.8988$ (or 0.8471 in case (3)), and m is the size of the output. This performance is the best currently known for linear-space data structures that can be deterministically constructed in polynomial time.}, author = {Yao, F. and Dobkin, David and Edelsbrunner, Herbert and Paterson, Michael}, issn = {1095-7111}, journal = {SIAM Journal on Computing}, number = {2}, pages = {371 -- 384}, publisher = {SIAM}, title = {{Partitioning space for range queries}}, doi = {10.1137/0218025}, volume = {18}, year = {1989}, } @article{4084, abstract = {A tour of a finite set P of points is a necklace-tour if there are disks with the points in P as centers such that two disks intersect if and only if their centers are adjacent in . It has been observed by Sanders that a necklace-tour is an optimal traveling salesman tour. In this paper, we present an algorithm that either reports that no necklace-tour exists or outputs a necklace-tour of a given set of n points in O(n2 log n) time. If a tour is given, then we can test in O(n2) time whether or not this tour is a necklace-tour. Both algorithms can be generalized to ƒ-factors of point sets in the plane. The complexity results rely on a combinatorial analysis of certain intersection graphs of disks defined for finite sets of points in the plane.}, author = {Edelsbrunner, Herbert and Rote, Günter and Welzl, Emo}, issn = {1879-2294}, journal = {Theoretical Computer Science}, number = {2}, pages = {157 -- 180}, publisher = {Elsevier}, title = {{Testing the necklace condition for shortest tours and optimal factors in the plane}}, doi = {10.1016/0304-3975(89)90133-3}, volume = {66}, year = {1989}, } @inproceedings{4085, abstract = {Let C be a cell complex in d-dimensional Euclidean space whose faces are obtained by orthogonal projection of the faces of a convex polytope in d + 1 dimensions. For example, the Delaunay triangulation of a finite point set is such a cell complex. This paper shows that the in_front/behind relation defined for the faces of C with respect to any fixed viewpoint x is acyclic. This result has applications to hidden line/surface removal and other problems in computational geometry.}, author = {Edelsbrunner, Herbert}, booktitle = {Proceedings of the 5th annual symposium on Computational geometry}, isbn = {978-0-89791-318-8}, location = {Saarbruchen, Germany}, pages = {145 -- 151}, publisher = {ACM}, title = {{An acyclicity theorem for cell complexes in d dimension}}, doi = {10.1145/73833.73850}, year = {1989}, } @article{4086, abstract = {This note proves that the maximum number of faces (of any dimension) of the upper envelope of a set ofn possibly intersectingd-simplices ind+1 dimensions is (n d (n)). This is an extension of a result of Pach and Sharir [PS] who prove the same bound for the number ofd-dimensional faces of the upper envelope.}, author = {Edelsbrunner, Herbert}, issn = {1432-0444}, journal = {Discrete & Computational Geometry}, number = {4}, pages = {337 -- 343}, publisher = {Springer}, title = {{The upper envelope of piecewise linear functions: Tight bounds on the number of faces }}, doi = {10.1007/BF02187734}, volume = {4}, year = {1989}, }