@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{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}, } @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{3467, abstract = {The effects of mast cell degranulating peptide (MCDP), a toxin from the honey bee, and of dendrotoxin (DTX), a toxin from the green mamba snake, were studied in voltage-clamped experiments with myelinated nerve fibres of Xenopus. MCDP and DTX blocked part of the K+ current. About 20% of the K+ current, however, was resistant to the toxins even in high concentrations. In Ringer solution half-maximal block was reached with concentrations of 33 nM MCDP and 11 nM DTX. In high-K+ solution the potency of both toxins was lower. β-Bungarotoxin (β-BuTX), another snake toxin, also blocked part of the K+ current, but was less potent than MCDP and DTX. Tail currents in high-K+ solution were analysed and three K+ current components were separated according to Dubois (1981b). Both MCDP and DTX selectively blocked a fast deactivating, slowly inactivating K+ current component which steeply activates between E = -60 mV and E = -40 mV (component f1). In concentrations around 100 nM, MCDP and DTX blocked neither the slow K+ current (component s) nor the fast deactivating, rapidly inactivating K+ current which activates between E = -40 mV and E = 20 mV (component f2). Similar results could be derived from K+ outward currents in Ringer solution. In high-K+, IC50 of MCDP for component f1 was 99 nM, whereas it was 7.6 μM for f2. Corresponding values for DTX are 68 nM and 1.8 μM. Binding studies with nerve fibre membranes of Xenopus reveal high-affinity binding sites for 125I-labelled DTX )K(D) = 22 pM in Ringer solution and 81 pM in high-K+ solution). 125I-labelled DTX can be displaced from its sites completely by unlabelled DTX, toxin I (black mamba toxin), MCDP, and partially by β-BuTX. Immunocytochemical staining demonstrates that binding sites for DTX are present in nodal and paranodal regions of the axonal membrane. The axonal membrane of motor and sensory nerve fibres is equipped with three types of well-characterized K+ channels and constitutes so far the best preparation to study MCDP- and DTX-sensitive K+ channels with electrophysiological and biochemical methods.}, author = {Bräu, Michael and Dreyer, Florian and Jonas, Peter M and Repp, Holger and Vogel, Werner}, issn = {1469-7793}, journal = {Journal of Physiology}, pages = {365 -- 385}, publisher = {Wiley-Blackwell}, title = {{A K+ channel in Xenopus nerve fibres selectively blocked by bee and snake toxins: binding and voltage-clamp experiments}}, doi = {10.1113/jphysiol.1990.sp017918}, volume = {420}, year = {1990}, } @inbook{3565, abstract = {We investigate the complexity of determining the shape and presentation (i.e. position with orientation) of convex polytopes in multi-dimensional Euclidean space using a variety of probe models.}, author = {Dobkin, David and Edelsbrunner, Herbert and Yap, Chee}, booktitle = {Autonomous Robot Vehicles}, editor = {Cox, Ingemar and Wilfong, Gordon}, isbn = {978-1-4613-8997-2}, pages = {328 -- 341}, publisher = {Springer}, title = {{Probing convex polytopes}}, doi = {10.1007/978-1-4613-8997-2_25}, year = {1990}, } @article{3650, abstract = {Hybrid zones can yield estimates of natural selection and gene flow. The width of a cline in gene frequency is approximately proportional to gene flow (σ) divided by the square root of per-locus selection ( &s). Gene flow also causes gametic correlations (linkage disequilibria) between genes that differ across hybrid zones. Correlations are stronger when the hybrid zone is narrow, and rise to a maximum roughly equal to s. Thus cline width and gametic correlations combine to give estimates of gene flow and selection. These indirect measures of σ and s are especially useful because they can be made from collections, and require no field experiments. The method was applied to hybrid zones between color pattern races in a pair of Peruvian Heliconius butterfly species. The species are Mullerian mimics of one another, and both show the same changes in warning color pattern across their respective hybrid zones. The expectations of cline width and gametic correlation were generated using simulations of clines stabilized by strong frequency-dependent selection. In the hybrid zone in Heliconius erato, clines at three major color pattern loci were between 8.5 and 10.2 km wide, and the pairwise gametic correlations peaked at R & 0.35. These measures suggest that s & 0.23 per locus, and that σ & 2.6 km. In erato, the shapes of the clines agreed with that expected on the basis of dominance. Heliconius melpomene has a nearly coincident hybrid zone. In this species, cline widths at four major color pattern loci varied between 11.7 and 13.4 km. Pairwise gametic correlations peaked near R & 1.00 for tightly linked genes, and at R & 0.40 for unlinked genes, giving s & 0.25 per locus and σ & 3.7 km. In melpomene, cline shapes did not perfectly fit theoretical shapes based on dominance; this deviation might be explained by long-distance migration and/or strong epistasis. Compared with erato, sample sizes in melpomene are lower and the genetics of its color patterns are less well understood. In spite of these problems, selection and gene flow are clearly of the same order of magnitude in the two species. The relatively high per locus selection coefficients agree with ``major gene'' theories for the evolution of Mullerian mimicry, but the genetic architecture of the color patterns does not. These results show that the genetics and evolution of mimicry are still only sketchily understood.}, author = {Mallet, James and Barton, Nicholas H and Lamas, Gerado and Santisteban, José and Muedas, Manuel and Eeley, Harriet}, issn = {0016-6731}, journal = {Genetics}, number = {4}, pages = {921 -- 936}, publisher = {Genetics Society of America}, title = {{Estimates of selection and gene flow from measures of cline width and linkage disequilibrium in Heliconius hybrid zones}}, doi = {10.1093/genetics/124.4.921}, volume = {124}, year = {1990}, } @article{3651, abstract = {It is widely held that each gene typically affects many characters, and that each character is affected by many genes. Moreover, strong stabilizing selection cannot act on an indefinitely large number of independent traits. This makes it likely that heritable variation in any one trait is maintained as a side effect of polymorphisms which have nothing to do with selection on that trait. This paper examines the idea that variation is maintained as the pleiotropic side effect of either deleterious mutation, or balancing selection. If mutation is responsible, it must produce alleles which are only mildly deleterious (s & 10(-3)), but nevertheless have significant effects on the trait. Balancing selection can readily maintain high heritabilities; however, selection must be spread over many weakly selected polymorphisms if large responses to artificial selection are to be possible. In both classes of pleiotropic model, extreme phenotypes are less fit, giving the appearance of stabilizing selection on the trait. However, it is shown that this effect is weak (of the same order as the selection on each gene): the strong stabilizing selection which is often observed is likely to be caused by correlations with a limited number of directly selected traits. Possible experiments for distinguishing the alternatives are discussed.}, author = {Barton, Nicholas H}, issn = {0016-6731}, journal = {Genetics}, number = {3}, pages = {773 -- 782}, publisher = {Genetics Society of America}, title = {{Pleiotropic models of quantitative variation}}, doi = {10.1093/genetics/124.3.773 }, volume = {124}, year = {1990}, } @article{4060, abstract = {This paper offers combinatorial results on extremum problems concerning the number of tetrahedra in a tetrahedrization of n points in general position in three dimensions, i.e. such that no four points are co-planar, It also presents an algorithm that in O(n log n) time constructs a tetrahedrization of a set of n points consisting of at most 3n-11 tetrahedra.}, author = {Edelsbrunner, Herbert and Preparata, Franco and West, Douglas}, issn = {1095-855X}, journal = {Journal of Symbolic Computation}, number = {3-4}, pages = {335 -- 347}, publisher = {Elsevier}, title = {{Tetrahedrizing point sets in three dimensions}}, doi = {10.1016/S0747-7171(08)80068-5}, volume = {10}, year = {1990}, } @article{4063, abstract = {This paper describes a general-purpose programming technique, called Simulation of Simplicity, that can be used to cope with degenerate input data for geometric algorithms. It relieves the programmer from the task of providing a consistent treatment for every single special case that can occur. The programs that use the technique tend to be considerably smaller and more robust than those that do not use it. We believe that this technique will become a standard tool in writing geometric software.}, author = {Edelsbrunner, Herbert and Mücke, Ernst}, issn = {1557-7368}, journal = {ACM Transactions on Graphics}, number = {1}, pages = {66 -- 104}, publisher = {ACM}, title = {{Simulation of simplicity: A technique to cope with degenerate cases in geometric algorithms}}, doi = {10.1145/77635.77639}, volume = {9}, year = {1990}, } @article{4064, abstract = {Given a set of data points pi = (xi, yi ) for 1 ≤ i ≤ n, the least median of squares regression line is a line y = ax + b for which the median of the squared residuals is a minimum over all choices of a and b. An algorithm is described that computes such a line in O(n 2) time and O(n) memory space, thus improving previous upper bounds on the problem. This algorithm is an application of a general method built on top of the topological sweep of line arrangements.}, author = {Edelsbrunner, Herbert and Souvaine, Diane}, issn = {1537-274X}, journal = {Journal of the American Statistical Association}, number = {409}, pages = {115 -- 119}, publisher = {American Statistical Association}, title = {{Computing least median of squares regression lines and guided topological sweep}}, doi = {10.1080/01621459.1990.10475313}, volume = {85}, year = {1990}, } @article{4065, abstract = {We prove that given n⩾3 convex, compact, and pairwise disjoint sets in the plane, they may be covered with n non-overlapping convex polygons with a total of not more than 6n−9 sides, and with not more than 3n−6 distinct slopes. Furthermore, we construct sets that require 6n−9 sides and 3n−6 slopes for n⩾3. The upper bound on the number of slopes implies a new bound on a recently studied transversal problem.}, author = {Edelsbrunner, Herbert and Robison, Arch and Shen, Xiao}, issn = {1872-681X}, journal = {Discrete Mathematics}, number = {2}, pages = {153 -- 164}, publisher = {Elsevier}, title = {{Covering convex sets with non-overlapping polygons}}, doi = {10.1016/0012-365X(90)90147-A}, volume = {81}, year = {1990}, } @article{4066, abstract = {We consider several problems involving points and planes in three dimensions. Our main results are: (i) The maximum number of faces boundingm distinct cells in an arrangement ofn planes isO(m 2/3 n logn +n 2); we can calculatem such cells specified by a point in each, in worst-case timeO(m 2/3 n log3 n+n 2 logn). (ii) The maximum number of incidences betweenn planes andm vertices of their arrangement isO(m 2/3 n logn+n 2), but this number is onlyO(m 3/5– n 4/5+2 +m+n logm), for any>0, for any collection of points no three of which are collinear. (iii) For an arbitrary collection ofm points, we can calculate the number of incidences between them andn planes by a randomized algorithm whose expected time complexity isO((m 3/4– n 3/4+3 +m) log2 n+n logn logm) for any>0. (iv) Givenm points andn planes, we can find the plane lying immediately below each point in randomized expected timeO([m 3/4– n 3/4+3 +m] log2 n+n logn logm) for any>0. (v) The maximum number of facets (i.e., (d–1)-dimensional faces) boundingm distinct cells in an arrangement ofn hyperplanes ind dimensions,d>3, isO(m 2/3 n d/3 logn+n d–1). This is also an upper bound for the number of incidences betweenn hyperplanes ind dimensions andm vertices of their arrangement. The combinatorial bounds in (i) and (v) and the general bound in (ii) are almost tight.}, author = {Edelsbrunner, Herbert and Guibas, Leonidas and Sharir, Micha}, issn = {1432-0444}, journal = {Discrete & Computational Geometry}, number = {1}, pages = {197 -- 216}, publisher = {Springer}, title = {{The complexity of many cells in arrangements of planes and related problems}}, doi = {10.1007/BF02187785}, volume = {5}, year = {1990}, } @inproceedings{4067, abstract = {This paper proves an O(m 2/3 n 2/3+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.}, author = {Edelsbrunner, Herbert and Sharir, Micha}, booktitle = {Proceedings of the International Symposium on Algorithms}, isbn = {978-3-540-52921-7}, location = {Tokyo, Japan}, pages = {419 -- 428}, publisher = {Springer}, title = {{A hyperplane Incidence problem with applications to counting distances}}, doi = {10.1007/3-540-52921-7_91}, volume = {450}, year = {1990}, } @article{4068, abstract = {LetS be a collection ofn convex, closed, and pairwise nonintersecting sets in the Euclidean plane labeled from 1 ton. A pair of permutations (i1i2in−1in)(inin−1i2i1) is called ageometric permutation of S if there is a line that intersects all sets ofS in this order. We prove thatS can realize at most 2n–2 geometric permutations. This upper bound is tight.}, author = {Edelsbrunner, Herbert and Sharir, Micha}, issn = {1432-0444}, journal = {Discrete & Computational Geometry}, number = {1}, pages = {35 -- 42}, publisher = {Springer}, title = {{The maximum number of ways to stabn convex nonintersecting sets in the plane is 2n−2}}, doi = {10.1007/BF02187778}, volume = {5}, year = {1990}, } @article{4069, 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}, issn = {1439-6912}, journal = {Combinatorica}, number = {3}, pages = {251 -- 260}, publisher = {Springer}, title = {{An acyclicity theorem for cell complexes in d dimension}}, doi = {10.1007/BF02122779}, volume = {10}, year = {1990}, } @article{4070, abstract = {Let S be a set of n closed intervals on the x-axis. A ranking assigns to each interval, s, a distinct rank, p(s)∊ [1, 2,…,n]. We say that s can see t if p(s)