A classification of data quality assessment and improvement methods

Data quality (DQ) assessment and improvement in larger information systems would often not be feasible without using suitable “DQ methods”, which are algorithms that can be automatically executed by computer systems to detect and/or correct problems in datasets. Currently, these methods are already essential, and they will be of even greater importance as the quantity of data in organisational systems grows. This paper provides a review of existing methods for both DQ assessment and improvement and classifies them according to the DQ problem and problem context. Six gaps have been identified in the classification, where no current DQ methods exist, and these show where new methods are required as a guide for future research and DQ tool development.This is the accepted manuscript. It's currently embargoed pending publication by Inderscience

Comment on "A centroid molecular dynamics study of liquid para hydrogen and ortho deuterium" [J. Chem. Phys. 121, 6412 (2004)]

We show that the two phase points considered in the recent simulations of liquid para hydrogen by Hone and Voth lie in the liquid-vapor coexistence region of a purely classical molecular dynamics simulation. By contrast, their phase point for ortho deuterium was in the one-phase liquid region for both classical and quantum simulations. These observations are used to account for their report that quantum mechanical effects enhance the diffusion in liquid para hydrogen and decrease it in ortho deuterium

Split versions of Cleave and Rescue selfish genetic elements for measured self limiting gene drive

Gene drive elements promote the spread of linked traits, providing methods for changing the composition or fate of wild populations. Drive mechanisms that are self-limiting are attractive because they allow control over the duration and extent of trait spread in time and space, and are reversible through natural selection as drive wanes. Self-sustaining Cleave and Rescue (ClvR) elements include a DNA sequence-modifying enzyme such as Cas9/gRNAs that disrupts endogenous versions of an essential gene, a tightly linked recoded version of the essential gene resistant to cleavage (the Rescue), and a Cargo. ClvR spreads by creating loss-of-function (LOF) conditions in which those without ClvR die because they lack functional copies of the essential gene. We use modeling to show that when the Rescue-Cargo and one or both components required for LOF allele creation (Cas9 and gRNA) reside at different locations (split ClvR), drive of Rescue-Cargo is self-limiting due to a progressive decrease in Cas9 frequency, and thus opportunities for creation of LOF alleles, as spread occurs. Importantly, drive strength and duration can be extended in a measured manner—which is still self-limiting—by moving the two components close enough to each other that they experience some degree of linkage. With linkage, Cas9 transiently experiences drive by hitchhiking with Rescue-Cargo until linkage disequilibrium between the two disappears, a function of recombination frequency and number of generations, creating a novel point of control. We implement split ClvR in Drosophila, with key elements on different chromosomes. Cargo/Rescue/gRNAs spreads to high frequency in a Cas9-dependent manner, while the frequency of Cas9 decreases. These observations show that measured, transient drive, coupled with a loss of future drive potential, can be achieved using the simple toolkit that make up ClvR elements—Cas9 and gRNAs and a Rescue/Cargo

Disponibilidade de documentos: um modelo de avaliação da satisfação da demanda em bibliotecas universitárias

O objetivo deste estudo foi avaliar o desempenhode três bibliotecas universitárias da PUC/RJ na satisfação da demanda expressa por seus usuários;mais especificamente, procurou-se medir a disponibilidade imediata de documentos. Foi utilizado o modelo Nível de Satisfação. Os resultados indicaram que as bibliotecas estudadas são capazes de satisfazer apenas cerca de 50% da demanda. Esse nível de desempenho é semelhante aos encontrados em bibliotecas universitárias de outros países. Concluiu-se que, embora o modelo Nível de Satisfação seja uma medida parcial de avaliação, seu valor emerge de suas características gerais de aplicabilidade. Descritores Biblioteca universitária. Nível de satisfação de usuários Abstract The purpose of this study was to evaluate the performance of three university libraries in order to satisfy user's expressed needs. A fundamental problem related to users's satisfaction was analyzed namely availability. The model satisfaction level was used. The results showed that the libraries analyzed can only satisfy 50% of the requests.However, these performance levels are similar to those found in university libraries from other more developed countries. Regardless of it's partial character as an evaluation measure, it was concluded that satisfaction level is a model of general applicability

Drivers of Convergence in Eleven Eastern European Countries, Policy Research Working Paper, 6185

This paper investigates the drivers of growth and prosperity in a group of eleven European countries -- Bulgaria, Croatia, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovenia, and Slovakia (the EU11). Since the EU11 began the transformation process, this group of emerging countries has made impressive strides as developing market economies and is anchoring development in European Union institutions. There are reasons to believe that the convergence of EU11 income per capita to Western European levels will continue, but will proceed more slowly. The paper concludes that trade and financial integration have sped along at a spectacular pace in the EU11 in the recent past, although trade in modern services and the integration of government bond and equity markets are somewhat behind. As in the rest of Europe, demographic developments will pose huge challenges for the sustainability of public finance in the EU11 economies. In the next several decades, the EU11 labor force is expected to contract more than labor forces in the rest of the European Union, making it even more urgent that countries in the region reform pension systems, change migration policy, and find incentives to attract talent to the region. Closing the gap with the rest of the European Union in educational attainment levels and improving education quality might significantly soften the constraints imposed by the demographic threats and produce sizable returns in terms of additional income convergence

Embedded-Cluster Calculations in a Numeric Atomic Orbital Density-Functional Theory Framework

We integrate the all-electron electronic structure code FHI-aims into the general ChemShell package for solid-state embedding (QM/MM) calculations. A major undertaking in this integration is the implementation of pseudopotential functionality into FHI-aims to describe cations at the QM/MM boundary through effective core potentials and therewith prevent spurious overpolarization of the electronic density. Based on numeric atomic orbital basis sets, FHI-aims offers particularly efficient access to exact exchange and second order perturbation theory, rendering the established QM/MM setup an ideal tool for hybrid and double-hybrid level DFT calculations of solid systems. We illustrate this capability by calculating the reduction potential of Fe in the Fe-substituted ZSM-5 zeolitic framework and the reaction energy profile for (photo-)catalytic water oxidation at TiO2(110).Comment: 12 pages, 4 figure

Prior-predictive value from fast growth simulations

Building on a variant of the Jarzynski equation we propose a new method to numerically determine the prior-predictive value in a Bayesian inference problem. The method generalizes thermodynamic integration and is not hampered by equilibration problems. We demonstrate its operation by applying it to two simple examples and elucidate its performance. In the case of multi-modal posterior distributions the performance is superior to thermodynamic integration.Comment: 8 pages, 11 figure

Gene drive that results in addiction to a temperature-sensitive version of an essential gene triggers population collapse in Drosophila

One strategy for population suppression seeks to use gene drive to spread genes that confer conditional lethality or sterility, providing a way of combining population modification with suppression. Stimuli of potential interest could be introduced by humans, such as an otherwise benign virus or chemical, or occur naturally on a seasonal basis, such as a change in temperature. Cleave and Rescue (ClvR) selfish genetic elements use Cas9 and guide RNAs (gRNAs) to disrupt endogenous versions of an essential gene while also including a Rescue version of the essential gene resistant to disruption. ClvR spreads by creating loss-of-function alleles of the essential gene that select against those lacking it, resulting in populations in which the Rescue provides the only source of essential gene function. As a consequence, if function of the Rescue, a kind of Trojan horse now omnipresent in a population, is condition dependent, so too will be the survival of that population. To test this idea, we created a ClvR in Drosophila in which Rescue activity of an essential gene, dribble, requires splicing of a temperature-sensitive intein (TS-ClvR^(dbe)). This element spreads to transgene fixation at 23 °C, but when populations now dependent on Ts-ClvR^(dbe) are shifted to 29 °C, death and sterility result in a rapid population crash. These results show that conditional population elimination can be achieved. A similar logic, in which Rescue activity is conditional, could also be used in homing-based drive and to bring about suppression and/or killing of specific individuals in response to other stimuli

Thermal and electronic fluctuations of flexible adsorbed molecules : azobenzene on Ag(111)

We investigate the thermal and electronic collective fluctuations that contribute to the finite-temperature adsorption properties of flexible adsorbates on surfaces on the example of the molecular switch azobenzene C12H10N2 on the Ag(111) surface. Using first-principles molecular dynamics simulations, we obtain the free energy of adsorption that accurately accounts for entropic contributions, whereas the inclusion of many-body dispersion interactions accounts for the electronic correlations that govern the adsorbate binding. We find the adsorbate properties to be strongly entropy driven, as can be judged by a kinetic molecular desorption prefactor of 10^24 s−1 that largely exceeds previously reported estimates. We relate this effect to sizable fluctuations across structural and electronic observables. A comparison of our calculations to temperature-programed desorption measurements demonstrates that finite-temperature effects play a dominant role for flexible molecules in contact with polarizable surfaces, and that recently developed first-principles methods offer an optimal tool to reveal novel collective behavior in such complex systems