Toward graph layout of large data visualization: algorithms, evaluations and application

Generating layouts for millions of points on a spatially-restricted platform is a difficult task with a unique set of constraints. These layouts are traditionally generated on a server out of sight of the user. User-oriented applications would benefit from a real-time view of layout generation, which can assist user decision making and improve user experience by introducing interactivity. The literature of constraint resolution and mobile visualization is briefly surveyed to achieve an understanding of the state of the art for this problem, and motivate a solution with scenario-based examples. We formally identify the major constraints associated with this specialized layout generation problem and the special interplay between them. A pipeline-based layout generation method is defined algorithmically, coupled with the implementation of the algorithm(s). The quality of the result is analyzed on a constraint-dependent basis. Applications and future system improvements and extensions are discussed

Toward graph layout of large data visualization: algorithms, evaluations and application

Generating layouts for millions of points on a spatially-restricted platform is a difficult task with a unique set of constraints. These layouts are traditionally generated on a server out of sight of the user. User-oriented applications would benefit from a real-time view of layout generation, which can assist user decision making and improve user experience by introducing interactivity. The literature of constraint resolution and mobile visualization is briefly surveyed to achieve an understanding of the state of the art for this problem, and motivate a solution with scenario-based examples. We formally identify the major constraints associated with this specialized layout generation problem and the special interplay between them. A pipeline-based layout generation method is defined algorithmically, coupled with the implementation of the algorithm(s). The quality of the result is analyzed on a constraint-dependent basis. Applications and future system improvements and extensions are discussed

Effect of External Loading on Durability Properties of Pre-Stressed Concrete Girders with Microcracking

Over the last fourteen years, very early in the service life of pre-stressed concrete girders, unexplained microcracks have been observed. Their presence led to concerns about the future integrity of the girders, with one of the major concerns being corrosion of pre-stressing strands. As such, a comprehensive study aimed at understanding the effects these microcracks have on the service life of the girders was initiated. Eight in-service girders, under external loads, and five rejected girders, not under external loads, were selected for the study. In this paper, we present work on the temporal evolution of the cracks during a one-year period. Two field visits were conducted to each girder, approximately one year apart, and the cracking index, crack width, strain measurements, surface resistivity and ultrasonic pulse velocity were measured. It was expected that the effects of external loads would lead to a more significant loss in durability. However, the results showed that exposure conditions and presence of pre-existing cracks had a more significant impact on the loss in durability than the presence of external loading

Investigation of High-Range Water Reducers on Inducing Micro-Cracking in Precast Concrete Elements

0-6813An overarching objective of this project is to increase the understanding of the effect of polycarboxylate (PC) high-range water-reducers (HRWR) on the performance of concrete mixtures, with a special focus on concrete mixtures that will be used in precast concrete beam applications. The motivation for this research was based upon the results of Interagency Contract (IAC) No. 463MTIA034: Evaluation of Long-Term Durability of Concrete, which addresses potential mechanisms for unexplained cracking in girders cast at Texas precast plants, typically appearing 18\u201324 months after casting

0-6813: Evaluation of ASTM C 494 Procedures for Polycarboxylate Admixtures Used in Precast Concrete Elements

0-6813An overarching objective of this project is to increase the understanding of the effect of polycarboxylate (PC) high-range water-reducers (HRWR) on the performance of concrete mixtures, with a special focus on concrete mixtures that will be used in precast concrete beam applications. The motivation for this research was based upon the results of Interagency Contract (IAC) No. 463MTIA034: Evaluation of Long-Term Durability of Concrete, which addresses potential mechanisms for unexplained cracking in girders cast at Texas precast plants, typically appearing 18\u201324 months after casting

Altered synaptobrevin-II trafficking in neurons expressing a synaptophysin mutation associated with a severe neurodevelopmental disorder

textabstractFollowing exocytosis, synaptic vesicles (SVs) have to be reformed with the correct complement of proteins in the correct stoichiometry to ensure continued neurotransmission. Synaptophysin is a highly abundant, integral SV protein necessary for the efficient retrieval of the SV SNARE protein, synaptobrevin II (sybII). However the molecular mechanism underpinning synaptophysin-dependent sybII retrieval is still unclear. We recently identified a male patient with severe intellectual disability, hypotonia, epilepsy and callosal agenesis who has a point mutation in the juxtamembrane region of the fourth transmembrane domain of synaptophysin (T198I). This mutation had no effect on the activity-dependent retrieval of synaptophysin that was tagged with the genetically-encoded pH-sensitive reporter (pHluorin) in synaptophysin knockout hippocampal cultures. This suggested the mutant has no global effect on SV endocytosis, which was confirmed when retrieval of a different SV cargo (the glutamate transporter vGLUT1) was examined. However neurons expressing this T198I mutant did display impaired activity-dependent sybII retrieval, similar to that observed in synaptophysin knockout neurons. Interestingly this impairment did not result in an increased stranding of sybII at the plasma membrane. Screening of known human synaptophysin mutations revealed a similar presynaptic phenotype between T198I and a mutation found in X-linked intellectual disability. Thus this novel human synaptophysin mutation has revealed that aberrant retrieval and increased plasma membrane localisation of SV cargo can be decoupled in human disease

Silencing Inhibits Cre-Mediated Recombination of the Z/AP and Z/EG Reporters in Adult Cells

BACKGROUND: The Cre-loxP system has been used to enable tissue specific activation, inactivation and mutation of many genes in vivo and has thereby greatly facilitated the genetic dissection of several cellular and developmental processes. In such studies, Cre-reporter strains, which carry a Cre-activated marker gene, are frequently utilized to validate the expression profile of Cre transgenes, to act as a surrogate marker for excision of a second allele, and to irreversibly label cells for lineage tracing experiments. PRINCIPAL FINDINGS: We have studied three commonly used Cre-reporter strains, Z/AP, Z/EG and R26R-EYFP and have demonstrated that although each reporter can be reliably activated by Cre during early development, exposure to Cre in adult hematopoietic cells results in a much lower frequency of marker-positive cells in the Z/AP or Z/EG strains than in the R26R-EYFP strain. In marker negative cells derived from the Z/AP and Z/EG strains, the transgenic promoter is methylated and Cre-mediated recombination of the locus is inhibited. CONCLUSIONS: These results show that the efficiency of Cre-mediated recombination is not only dependent on the genomic context of a given loxP-flanked sequence, but also on stochastic epigenetic mechanisms underlying transgene variegation. Furthermore, our data highlights the potential shortcomings of utilizing the Z/AP and Z/EG reporters as surrogate markers of excision or in lineage tracing experiments

The N-Terminal Domain of the Arenavirus L Protein Is an RNA Endonuclease Essential in mRNA Transcription

Arenaviridae synthesize viral mRNAs using short capped primers presumably acquired from cellular transcripts by a ‘cap-snatching’ mechanism. Here, we report the crystal structure and functional characterization of the N-terminal 196 residues (NL1) of the L protein from the prototypic arenavirus: lymphocytic choriomeningitis virus. The NL1 domain is able to bind and cleave RNA. The 2.13 Å resolution crystal structure of NL1 reveals a type II endonuclease α/β architecture similar to the N-terminal end of the influenza virus PA protein. Superimposition of both structures, mutagenesis and reverse genetics studies reveal a unique spatial arrangement of key active site residues related to the PD…(D/E)XK type II endonuclease signature sequence. We show that this endonuclease domain is conserved and active across the virus families Arenaviridae, Bunyaviridae and Orthomyxoviridae and propose that the arenavirus NL1 domain is the Arenaviridae cap-snatching endonuclease