Collaborative Online Learning For Join Processing

Relational binary operators, such as join, are arguably the most costly and frequently used operations in relational data systems. In many join algorithms, the majority of the process time is spent on scanning and attempting to join the parts of the relations that do not satisfy the join condition and do not generate any join results. It causes slow response time, particularly, in interactive and exploratory environment where users would like real-time performance. Current solutions to this problem usually require lengthy and repeating preprocessings, which are costly in general settings and may not be possible to do in some, such as interactive and exploratory workloads. They may support only for a restricted types of joins. In this report, we outline a novel approach for achieving efficient join processing in which a scan operator learns online and during query execution the portions of its underlying relation that may satisfy the join condition and use them for join sooner. We further improve this method by an algorithm in which both scan operators collaboratively learn an efficient join execution strategy. We also show that this approach generalizes traditional and non-learning methods of join. Our empirical studies using standard benchmarks indicate that this approach outperforms similar methods considerably

Comparative genomics of five Valsa species gives insights on their pathogenicity evolution

Valsa is a genus of ascomycetes within the Valsaceae family. This family includes many wood destructive pathogens such as the well known Valsa mali and Valsa pyri which cause canker diseases in fruit trees and threaten the global fruit production. Lack of genomic information of this family is impeding our understandings about their evolution and genetic basis of their pathogenicity divergence. Here, we report genome assemblies of Valsa malicola, Valsa persoonii, and Valsa sordida which represent close relatives of Valsa mali and Valsa pyri with different host preferences. Comparative genomics analysis revealed that segmental rearrangements, inversions, and translocations frequently occurred among Valsa spp. genomes. Gene families that exhibited gene copy expansions tended to be associated with secondary metabolism, transmembrane transport, and pyrophosphatase activities. Orthologous genes in regions lost synteny exhibited significantly higher rate of synonymous substitution (KS) than those in regions retained synteny. Moreover, among these genes, membrane transporter families associated with antidrug (MFS, DHA) activities and nutrient transportation (SP and APCs) activities were significantly over-represented. Lineage specific synonymous substitution (KS) and nonsynonymous substitution (KA) analysis based on the phylogeny constructed from 11 fungal species identified a set of genes with selection signatures in Valsa clade and these genes were significantly enriched in functions associated with fatty acid beta-oxidation, DNA helicase activity, and ATPase activity. Furthermore, unique genes that possessed or retained by each of the five Valsa species are more likely part of the secondary metabolic (SM) gene clusters. SM gene clusters conserved across five Valsa species showed various degrees of diversification in both identity and completeness. All 11 syntenically conserved SM clusters showed differential expression during the infection of apple branch with Valsa mali suggesting involvements of secondary metabolism in the pathogenicity of Valsa species

Novel link between E2F1 and Smac/DIABLO: proapoptotic Smac/DIABLO is transcriptionally upregulated by E2F1

Deregulated expression of E2F1 not only promotes S-phase entry but also induces apoptosis. Although it has been well documented that E2F1 is able to induce p53-dependent apoptosis via raising ARF activity, the mechanism by which E2F induces p53-independent apoptosis remains unclear. Here we report that E2F1 can directly bind to and activate the promoter of Smac/DIABLO, a mitochondrial proapoptotic gene, through the E2F1-binding sites BS2 (−542 ∼ −535 bp) and BS3 (−200 ∼ −193 bp). BS2 and BS3 appear to be utilized in combination rather than singly by E2F1 in activation of Smac/DIABLO. Activation of BS2 and BS3 are E2F1-specific, since neither E2F2 nor E2F3 is able to activate BS2 or BS3. Using the H1299 ER-E2F1 cell line where E2F1 activity can be conditionally induced, E2F1 has been shown to upregulate the Smac/DIABLO expression at both mRNA and protein levels upon 4-hydroxytamoxifen treatment, resulting in an enhanced mitochondria-mediated apoptosis. Reversely, reducing the Smac/DIABLO expression by RNA interference significantly diminishes apoptosis induced by E2F1. These results may suggest a novel mechanism by which E2F1 promotes p53-independent apoptosis through directly regulating its downstream mitochondrial apoptosis-inducing factors, such as Smac/DIABLO

RGS2 Determines Short-Term Synaptic Plasticity in Hippocampal Neurons by Regulating Gi/o- Mediated Inhibition of Presynaptic Ca2+ Channels

SummaryRGS2, one of the small members of the regulator of G protein signaling (RGS) family, is highly expressed in brain and regulates Gi/o as well as Gq-coupled receptor pathways. RGS2 modulates anxiety, aggression, and blood pressure in mice, suggesting that RGS2 regulates synaptic circuits underlying animal physiology and behavior. How RGS2 in brain influences synaptic activity is unknown. We therefore analyzed the synaptic function of RGS2 in hippocampal neurons by comparing electrophysiological recordings from RGS2 knockout and wild-type mice. Our study provides a general mechanism of the action of the RGS family containing RGS2 by demonstrating that RGS2 increases synaptic vesicle release by downregulating the Gi/o-mediated presynaptic Ca2+ channel inhibition and therefore provides an explanation of how regulation of RGS2 expression can modulate the function of neuronal circuits underlying behavior

Facilitation versus depression in cultured hippocampal neurons determined by targeting of Ca2+ channel Cavβ4 versus Cavβ2 subunits to synaptic terminals

Ca2+ channel β subunits determine the transport and physiological properties of high voltage–activated Ca2+ channel complexes. Our analysis of the distribution of the Cavβ subunit family members in hippocampal neurons correlates their synaptic distribution with their involvement in transmitter release. We find that exogenously expressed Cavβ4b and Cavβ2a subunits distribute in clusters and localize to synapses, whereas Cavβ1b and Cavβ3 are homogenously distributed. According to their localization, Cavβ2a and Cavβ4b subunits modulate the synaptic plasticity of autaptic hippocampal neurons (i.e., Cavβ2a induces depression, whereas Cavβ4b induces paired-pulse facilitation [PPF] followed by synaptic depression during longer stimuli trains). The induction of PPF by Cavβ4b correlates with a reduction in the release probability and cooperativity of the transmitter release. These results suggest that Cavβ subunits determine the gating properties of the presynaptic Ca2+ channels within the presynaptic terminal in a subunit-specific manner and may be involved in organization of the Ca2+ channel relative to the release machinery

Battery of behavioral tests in mice to study postoperative delirium

Postoperative delirium is associated with increased morbidity, mortality and cost. However, its neuropathogenesis remains largely unknown, partially owing to lack of animal model(s). We therefore set out to employ a battery of behavior tests, including natural and learned behavior, in mice to determine the effects of laparotomy under isoflurane anesthesia (Anesthesia/Surgery) on these behaviors. The mice were tested at 24 hours before and at 6, 9 and 24 hours after the Anesthesia/Surgery. Composite Z scores were calculated. Cyclosporine A, an inhibitor of mitochondria permeability transient pore, was used to determine potential mitochondria-associated mechanisms of these behavioral changes. Anesthesia/Surgery selectively impaired behaviors, including latency to eat food in buried food test, freezing time and time spent in the center in open field test, and entries and duration in the novel arm of Y maze test, with acute onset and various timecourse. The composite Z scores quantitatively demonstrated the Anesthesia/Surgery-induced behavior impairment in mice. Cyclosporine A selectively ameliorated the Anesthesia/Surgery-induced reduction in ATP levels, the increases in latency to eat food, and the decreases in entries in the novel arm. These findings suggest that we could use a battery of behavior tests to establish a mouse model to study postoperative delirium

Controllable growth of In(OH)(3) nanorods with rod-in-rod structure in a surfactant solution

通讯作者地址: Xie, SY (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Dept Chem, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Dept Chem, Xiamen 361005, Peoples R ChinaThe In(OH)(3) nanorods (25-55 nm in diameter and 120-200 nm in length) bearing parallel subunit nanorods (diameters ranging from 8 to 10 nm) were synthesized by controlling hydrolysis of indium nitrate in the presence of hexamethylene tetraamine and cetyltrimethylammonium bromide. (C) 2003 Elsevier B.V. All rights reserved