5,8-Dihydroxyquinoline and Its Nickel Derivatives

Many derivatives of 8-hydroxyquinoline have been prepared and examined, some looking toward increased specificity as precipitating reagents, others toward an increase in the intensity of the color of the metal derivatives. Of the derivatives which have been studied, attention has been centered principally on the alkyl and halogen derivatives on the one hand and on the aromatic azo derivatives on the other. This paper deals with the preparation and properties of an 8-hydroxyquinoline bearing a second hydroxyl group, 5,8-dihydroxyquinoline. In this substance are combined the properties of chelate ring formation with metals and the oxidation-reduction behavior characteristic of the hydroquinones

Could parental rules play a role in the association between short sleep and obesity in young children?

Short sleep duration is associated with obesity in young children. This study develops the hypothesis that parental rules play a role in this association. Participants were 3-year-old children and their parents, recruited at nursery schools in socioeconomically deprived and non-deprived areas of a North-East England town. Parents were interviewed to assess their use of sleep, television-viewing and dietary rules, and given diaries to document their child's sleep for 4 days/5 nights. Children were measured for height, weight, waist circumference and triceps and subscapular skinfold thicknesses. One-hundred and eight families participated (84 with complete sleep data and 96 with complete body composition data). Parental rules were significantly associated together, were associated with longer night-time sleep and were more prevalent in the non-deprived-area compared with the deprived-area group. Television-viewing and dietary rules were associated with leaner body composition. Parental rules may in part confound the association between night-time sleep duration and obesity in young children, as rules cluster together across behavioural domains and are associated with both sleep duration and body composition. This hypothesis should be tested rigorously in large representative samples

Direct imaging of single UvrD helicase dynamics on long single-stranded DNA

Fluorescence imaging of single-protein dynamics on DNA has been largely limited to double-stranded DNA or short single-stranded DNA. We have developed a hybrid approach for observing single proteins moving on laterally stretched kilobase-sized ssDNA. Here we probed the single-stranded DNA translocase activity of Escherichia coli UvrD by single fluorophore tracking, while monitoring DNA unwinding activity with optical tweezers to capture the entire sequence of protein binding, single-stranded DNA translocation and multiple pathways of unwinding initiation. The results directly demonstrate that the UvrD monomer is a highly processive single-stranded DNA translocase that is stopped by a double-stranded DNA, whereas two monomers are required to unwind DNA to a detectable degree. The single-stranded DNA translocation rate does not depend on the force applied and displays a remarkable homogeneity, whereas the unwinding rate shows significant heterogeneity. These findings demonstrate that UvrD assembly state regulates its DNA helicase activity with functional implications for its stepping mechanism, and also reveal a previously unappreciated complexity in the active species during unwinding

Initial Vibration Analysis of the Advanced Stirling Radioisotope Generator's (ASRG's) Affect on Spacecraft Instruments

Assess if nominal Advanced Stirling Radioisotope Generator (ASRG) vibration levels are sufficiently benign for unimpeded spacecraft instrument operation

Forecasting the cost of processing multi-join queries via hashing for main-memory databases (Extended version)

Database management systems (DBMSs) carefully optimize complex multi-join queries to avoid expensive disk I/O. As servers today feature tens or hundreds of gigabytes of RAM, a significant fraction of many analytic databases becomes memory-resident. Even after careful tuning for an in-memory environment, a linear disk I/O model such as the one implemented in PostgreSQL may make query response time predictions that are up to 2X slower than the optimal multi-join query plan over memory-resident data. This paper introduces a memory I/O cost model to identify good evaluation strategies for complex query plans with multiple hash-based equi-joins over memory-resident data. The proposed cost model is carefully validated for accuracy using three different systems, including an Amazon EC2 instance, to control for hardware-specific differences. Prior work in parallel query evaluation has advocated right-deep and bushy trees for multi-join queries due to their greater parallelization and pipelining potential. A surprising finding is that the conventional wisdom from shared-nothing disk-based systems does not directly apply to the modern shared-everything memory hierarchy. As corroborated by our model, the performance gap between the optimal left-deep and right-deep query plan can grow to about 10X as the number of joins in the query increases.Comment: 15 pages, 8 figures, extended version of the paper to appear in SoCC'1

Baten en kosten van natuur. Een regionale analyse van het Roerdal

Natuur kost niet alleen geld, maar levert ook wat op. In dit onderzoek zijn de kosten en baten van ontwikkeling van natuur in het Roerdal in de periode 1994-2000 geïnventariseerd en zoveel mogelijk gekwantificeerd. Het Roerdal is een onderdeel van het Waardevolle Cultuurlandschap (WCL) Midden-Limburg. De activiteiten van beheerders in het Roerdal zijn grotendeels gefinancierd uit WCL-middelen en andere subsidies, waarschijnlijk van de rijksoverheid. Deze activiteiten leveren baten op voor andere actorgroepen. Vooral recreatieve bedrijven in het Roerdal ontlenen baten aan natuurontwikkeling. Daarnaast zijn er waarschijnlijk baten voor huizenbezitters en blijkt het Roerdal niet-gebruikswaarde te hebben. Deze baten overtreffen de kosten die beheerders hebben gemaakt. Tegen de achtergrond dat het WCL-beleid ten einde is en ook andere subsidiëring door de rijksoverheid niet voor altijd zeker is, is onderzocht welke mogelijkheden er zijn voor verzilvering. Dit betekent dat nieuwe initiatieven moeten worden genomen om de gebiedskwaliteit te behouden en verder te verbeteren, waarbij beheerders en andere actoren in het gebied samenwerken en tot overeenstemming komen over een financiële verdeling. Op basis van de analyse van kosten en baten lijken er mogelijkheden te zijn om tot samenwerking te komen die voor alle partijen voordelig is

Proposal for a Performance Dashboard for the Monitoringof Water and Sewage Service Companies (WaSCs)

The water and sewage industry provides an essential service to the community, but it is characterized by natural monopoly tendencies of service suppliers. In this framework, it is very important to assist regulators with a small set of critical indicators (performance dashboard) for the evaluation and monitoring of the service provided by Water and Sewage Companies (WaSCs). The paper originates from the analysis of situation of Piemonte (Italy), where each regional and local body adopts a proprietary Performance Measurement System (PMS). In order to improve the coordination of information flow and to support the definition of common service standards, a methodology to merge existing PMSs and define a unique shared reference system is proposed. The Kaplan and Norton's Balanced Scorecard (BSC) is adopted as the reference model of this approach. BSC is widely recognized to be an exhaustive and balanced framework in describing the performances of an organization and ensures that all the operational aspects of WaSCs are adequately monitored. The output of the proposed procedure is a general performance dashboard for the monitoring of WaSCs. The dashboard is shown and some remarks about indicators properties are developed. In particular, this analysis highlights some common pitfalls originated by a ‘rushed' aggregation of several performance indicators. Description is supported by several example