A scheduling algorithm for Spacelab telescope observations

An algorithm is developed for sequencing and scheduling of observations of stellar targets by equipment on Spacelab. The method is a general one. The scheduling problem is defined and examined. The method developed for its solution is documented. Suggestions for further development and implementation of this method are made

Disrupting Complex Systems with Emerging Technologies: A Study on United States Airport Operations

The number of United States domestic commercial flight passengers are growing every year, which means the number of people checking-in, dropping off their bags, and going through TSA within airports is equally growing. With the increasing number of passengers and aging airports, there are several areas of pain points within airports where passengers hit a bottleneck due to the current systems that airports have in place. There are three main areas that we are going to reference. First the check-in process, where customers have to get their tickets, input identification information, and check-in for their flight. Second, baggage-drop off, where customers get their baggage weighed and tagged. Lastly, is Transport Security Administration (TSA). This is where consumers get their carry-on bags scanned as well as their person. In each of these areas, there are some levels of inconvenience imposed on the customer by the current system. With technological advancements being used in other industries, the goal of this thesis is to look at what existing technologies can be modified and used within airport operations to reduce the long lines that customers face every time they travel

On the spectra of nonsymmetric Laplacian matrices

A Laplacian matrix is a square real matrix with nonpositive off-diagonal entries and zero row sums. As a matrix associated with a weighted directed graph, it generalizes the Laplacian matrix of an ordinary graph. A standardized Laplacian matrix is a Laplacian matrix with the absolute values of the off-diagonal entries not exceeding 1/n, where n is the order of the matrix. We study the spectra of Laplacian matrices and relations between Laplacian matrices and stochastic matrices. We prove that the standardized Laplacian matrices are semiconvergent. The multiplicities of 0 and 1 as the eigenvalues of a standardized Laplacian matrix are equal to the in-forest dimension of the corresponding digraph and one less than the in-forest dimension of the complementary digraph, respectively. These eigenvalues are semisimple. The spectrum of a standardized Laplacian matrix belongs to the meet of two closed disks, one centered at 1/n, another at 1-1/n, each having radius 1-1/n, and two closed angles, one bounded with two half-lines drawn from 1, another with two half-lines drawn from 0 through certain points. The imaginary parts of the eigenvalues are bounded from above by 1/(2n) cot(pi/2n); this maximum converges to 1/pi as n goes to infinity. Keywords: Laplacian matrix; Laplacian spectrum of graph; Weighted directed graph; Forest dimension of digraph; Stochastic matrixComment: 11 page

Behavioral Comorbidities and Drug Treatments in a Zebrafish scn1lab Model of Dravet Syndrome.

Loss-of-function mutations in SCN1A cause Dravet syndrome (DS), a catastrophic childhood epilepsy in which patients experience comorbid behavioral conditions, including movement disorders, sleep abnormalities, anxiety, and intellectual disability. To study the functional consequences of voltage-gated sodium channel mutations, we use zebrafish with a loss-of-function mutation in scn1lab, a zebrafish homolog of human SCN1A. Homozygous scn1labs552/s552 mutants exhibit early-life seizures, metabolic deficits, and early death. Here, we developed in vivo assays using scn1labs552 mutants between 3 and 6 d postfertilization (dpf). To evaluate sleep disturbances, we monitored larvae for 24 h with locomotion tracking software. Locomotor activity during dark (night phase) was significantly higher in mutants than in controls. Among anticonvulsant drugs, clemizole and diazepam, but not trazodone or valproic acid, decreased distance moved at night for scn1labs552 mutant larvae. To monitor exploratory behavior in an open field, we tracked larvae in a novel arena. Mutant larvae exhibited impaired exploratory behavior, with increased time spent near the edge of the arena and decreased mobility, suggesting greater anxiety. Both clemizole and diazepam, but not trazodone or valproic acid, decreased distance moved and increased time spent in the center of the arena. Counting inhibitory neurons in vivo revealed no differences between scn1labs552 mutants and siblings. Taken together, our results demonstrate conserved features of sleep, anxiety, and movement disorders in scn1lab mutant zebrafish, and provide evidence that a zebrafish model allows effective tests of treatments for behavioral comorbidities associated with DS

Markov chains and tensor multiplications

AbstractAn m-dimensional matrix of order n over a field F is an array A = [ai1, ai2…im]; 1 ⩽ ij ⩽ n; 1 ⩽ j ⩽ m, of nm elements of F. This definition coincides with the notion of an m-fold tensor over Fn, and also of an n × n matrix when m = 2. In this paper two multiplications on such objects are examined. The first is nonassociative and is motivated by a generalization of a Markov chain. The second is associative, and related to the first by a certain generalized transpose operator. Spectral and unitary properties of the associative multiplication are discussed, as well as connections with block-diagonal matrix multiplication. A connection between graphs and the nonassociative multiplication is exhibited

Facilitating cross-chain cryptocurrency exchanges: An inquiry into blockchain technology and interoperability with an emphasis on cryptocurrency arbitrage

Since the introduction and proliferation of the blockchain-based cryptocurrency Bitcoin, alternative cryptocurrencies also based on blockchain technology have exploded in number. It was once believed that one, or very few, cryptocurrencies would eventually dominate the market and drive out competitors. This assumption, however, was incorrect. Thousands of cryptocurrencies exist concurrently. The vast number of cryptocurrencies leads to a problem—what if the cryptocurrency that an individual possesses does not meet their current needs as well as another cryptocurrency might? The attempt to solve this problem has led to the rise of many cryptocurrency exchanges and exchange schemes. In this paper, we will discuss the motivations for an individual to be interested in exchanging two or more cryptocurrencies by describing and comparing various popular cryptocurrencies with different desirable attributes. While we will discuss these attributes, this paper will give special focus to arbitrage in particular. In addition, we will describe various cryptocurrency exchange schemes and their advantages and disadvantages. Finally, we contribute to the understanding of cryptocurrency exchangeability and interoperability by comparing the historical price data of several cryptocurrencies to determine how often arbitrage has been possible in the past

Indecomposable laplacian integral graphs

AbstractA graph that can be constructed from isolated vertices by the operations of union and complement is decomposable. Every decomposable graph is Laplacian integral. i.e., its Laplacian spectrum consists entirely of integers. An indecomposable graph is not decomposable. The main purpose of this note is to demonstrate the existence of infinitely many indecomposable Laplacian integral graphs

A second corticotropin-releasing hormone gene (CRH2) is conserved across vertebrate classes and expressed in the hindbrain of a basal Neopterygian fish, the spotted gar (Lepisosteus oculatus)

© 2015 Wiley Periodicals, Inc. To investigate the origins of the vertebrate stress-response system, we searched sequenced vertebrate genomes for genes resembling corticotropin-releasing hormone (CRH). We found that vertebrate genomes possess, in addition to CRH, another gene that resembles CRH in sequence and syntenic environment. This paralogous gene was previously identified only in the elephant shark (a holocephalan), but we find it also in marsupials, monotremes, lizards, turtles, birds, and fishes. We examined the relationship of this second vertebrate CRH gene, which we name CRH2, to CRH1 (previously known as CRH) and urocortin1/urotensin1 (UCN1/UTS1) in primitive fishes, teleosts, and tetrapods. The paralogs CRH1 and CRH2 likely evolved via duplication of CRH during a whole-genome duplication early in the vertebrate lineage. CRH2 was subsequently lost in both teleost fishes and eutherian mammals but retained in other lineages. To determine where CRH2 is expressed relative to CRH1 and UTS1, we used in situ hybridization on brain tissue from spotted gar (Lepisosteus oculatus), a neopterygian fish closely related to teleosts. In situ hybridization revealed widespread distribution of both crh1 and uts1 in the brain. Expression of crh2 was restricted to the putative secondary gustatory/secondary visceral nucleus, which also expressed calcitonin-related polypeptide alpha (calca), a marker of parabrachial nucleus in mammals. Thus, the evolutionary history of CRH2 includes restricted expression in the brain, sequence changes, and gene loss, likely reflecting release of selective constraints following whole-genome duplication. The discovery of CRH2 opens many new possibilities for understanding the diverse functions of the CRH family of peptides across vertebrates

Three Distinct Glutamate Decarboxylase Genes in Vertebrates

Gamma-aminobutyric acid (GABA) is a widely conserved signaling molecule that in animals has been adapted as a neurotransmitter. GABA is synthesized from the amino acid glutamate by the action of glutamate decarboxylases (GADs). Two vertebrate genes, GAD1 and GAD2, encode distinct GAD proteins: GAD67 and GAD65, respectively. We have identified a third vertebrate GAD gene, GAD3. This gene is conserved in fishes as well as tetrapods. We analyzed protein sequence, gene structure, synteny, and phylogenetics to identify GAD3 as a homolog of GAD1 and GAD2. Interestingly, we found that GAD3 was lost in the hominid lineage. Because of the importance of GABA as a neurotransmitter, GAD3 may play important roles in vertebrate nervous systems