Gene Expression of Candidate Chemoreceptor Protein Families in Transcriptomes of Two Major Chemosensory Organs and Brain in Decapod Crustaceans

Chemoreceptor proteins are necessary for animals to detect chemical signals and cues in their environment in a process known as chemical sensing. The diversity and number of chemoreceptor proteins have been characterized in many groups of animals, but few have studied the repertoire of chemoreceptor proteins expressed by decapod crustaceans. Crustaceans express at least three classes of putative chemoreceptor proteins. These are: Variant Ionotropic Receptors (IRs), derived from the ionotropic glutamate receptors (iGluRs); Transient Receptor Potential (TRP) channels, a diverse set of sensor-channels; and Gustatory Receptor Like receptors (GRLs), a family of ionotropic receptor proteins that are ancestral to Gustatory Receptors (GRs) of insects. IRs are typically the most numerically dominant of these receptor proteins in crustaceans. In order to identify families of candidate chemoreceptor proteins that are expressed by decapod crustaceans, I examined and compared transcriptomes from four decapod crustaceans that are established models of chemoreception: the Caribbean spiny lobster Panulirus argus, the clawed lobster Homarus americanus, the red swamp crayfish Procambarus clarkii, and the blue crab Callinectes sapidus. Transcriptomes were generated from: a) two major chemosensory organs, the lateral flagella of the antennules (LF) and dactyls of the walking legs (dactyl), of all four decapod crustaceans; and b) the supraesophageal ganglion (brain) of only three decapod crustaceans, P. argus, H. americanus, and P. clarkii. Each species expressed genes for at least ca. 100 to 250 IRs, ca. 15 TRP channels including those shown to be chemoreceptors in other species, and 1 to 4 GRLs. The IRs show different degrees of phylogenetic conservation: protostome-conserved, arthropod-conserved, pancrustacean-conserved, crustacean-conserved, and species-specific. Many IRs appear to be more highly expressed in the LF than dactyl. In the brain transcriptomes, few IRs, almost all TRP channels, and GRLs (in the case of H. americanus) were also detected. Immunocytochemistry in LF and dactyl of P. argus and H. americanus, revealed protein expression of co-receptor IR, IR25a, in olfactory sensory neurons and chemosensory neurons. This research lays the foundation for future functional studies by showing that decapod crustaceans have an abundance of gene expression for chemoreceptor proteins of different types, phylogenetic conservation, and expression patterns

Unsupervised Learning with Self-Organizing Spiking Neural Networks

We present a system comprising a hybridization of self-organized map (SOM) properties with spiking neural networks (SNNs) that retain many of the features of SOMs. Networks are trained in an unsupervised manner to learn a self-organized lattice of filters via excitatory-inhibitory interactions among populations of neurons. We develop and test various inhibition strategies, such as growing with inter-neuron distance and two distinct levels of inhibition. The quality of the unsupervised learning algorithm is evaluated using examples with known labels. Several biologically-inspired classification tools are proposed and compared, including population-level confidence rating, and n-grams using spike motif algorithm. Using the optimal choice of parameters, our approach produces improvements over state-of-art spiking neural networks

Horoball Packing Density Lower Bounds in Higher Dimensional Hyperbolic nn-space for 6≤n≤96 \leq n \leq 9

Koszul type Coxeter Simplex tilings exist in hyperbolic space $\mathbb{H}^n$ for $2 \leq n \leq 9$, and their horoball packings have the highest known regular ball packing densities for $3 \leq n \leq 5$. In this paper we determine the optimal horoball packings of Koszul type Coxeter simplex tilings of $n$-dimensional hyperbolic space for $6 \leq n \leq 9$, which give new lower bounds for packing density in each dimension. The symmetries of the packings are given by Coxeter simplex groups.Comment: 16 Pages, 6 Tables, 1 Figure. arXiv admin note: substantial text overlap with arXiv:1809.05411, arXiv:1401.608

Absolute Freedom of Opinion and Sentiment on All Subjects: John Stuart Mill’s Enduring (and Ever-Growing) Influence on the Supreme Court’s First Amendment Free Speech Jurisprudence

A majority of Justices on the contemporary U.S. Supreme Court have increasingly adopted a largely libertarian view of the constitutional right to the freedom of expression. Indeed, on issues ranging from campaign finance to offensive speech to symbolic speech to commercial speech to online expression, the Court has struck down many laws on free speech grounds. Much of the reasoning in these cases mirrors John Stuart Mill’s arguments in On Liberty. This is not new, as Mill’s position on free speech has been advocated by some members of the Court for a century. However, the advocacy of Mill’s position has grown over time, to the point now where it is the dominant view expressed by the Justices in free speech cases. Even where the majority has in recent years found limits to free speech rights (including in cases involving student speech, public employee speech, and speech related to foreign terrorist organizations), several Justices have advocated a Millian framework and arguably followed the exceptions that Mill outlined when advocating the Harm Principle for free speech. Through textual analysis of illustrative cases we demonstrate the growth of Mill’s influence on the Supreme Court and where the Justices have deviated from what Mill advocated

The Landscape of Bounds for Binary Search Trees

Binary search trees (BSTs) with rotations can adapt to various kinds of structure in search sequences, achieving amortized access times substantially better than the Theta(log n) worst-case guarantee. Classical examples of structural properties include static optimality, sequential access, working set, key-independent optimality, and dynamic finger, all of which are now known to be achieved by the two famous online BST algorithms (Splay and Greedy). (...) In this paper, we introduce novel properties that explain the efficiency of sequences not captured by any of the previously known properties, and which provide new barriers to the dynamic optimality conjecture. We also establish connections between various properties, old and new. For instance, we show the following. (i) A tight bound of O(n log d) on the cost of Greedy for d-decomposable sequences. The result builds on the recent lazy finger result of Iacono and Langerman (SODA 2016). On the other hand, we show that lazy finger alone cannot explain the efficiency of pattern avoiding sequences even in some of the simplest cases. (ii) A hierarchy of bounds using multiple lazy fingers, addressing a recent question of Iacono and Langerman. (iii) The optimality of the Move-to-root heuristic in the key-independent setting introduced by Iacono (Algorithmica 2005). (iv) A new tool that allows combining any finite number of sound structural properties. As an application, we show an upper bound on the cost of a class of sequences that all known properties fail to capture. (v) The equivalence between two families of BST properties. The observation on which this connection is based was known before - we make it explicit, and apply it to classical BST properties. (...

Random graph asymptotics on high-dimensional tori. II. Volume, diameter and mixing time

For critical bond-percolation on high-dimensional torus, this paper proves sharp lower bounds on the size of the largest cluster, removing a logarithmic correction in the lower bound in Heydenreich and van der Hofstad (2007). This improvement finally settles a conjecture by Aizenman (1997) about the role of boundary conditions in critical high-dimensional percolation, and it is a key step in deriving further properties of critical percolation on the torus. Indeed, a criterion of Nachmias and Peres (2008) implies appropriate bounds on diameter and mixing time of the largest clusters. We further prove that the volume bounds apply also to any finite number of the largest clusters. The main conclusion of the paper is that the behavior of critical percolation on the high-dimensional torus is the same as for critical Erdos-Renyi random graphs. In this updated version we incorporate an erratum to be published in a forthcoming issue of Probab. Theory Relat. Fields. This results in a modification of Theorem 1.2 as well as Proposition 3.1.Comment: 16 pages. v4 incorporates an erratum to be published in a forthcoming issue of Probab. Theory Relat. Field