Spatial variability in correlation decay distance and influence on angular-distance weighting interpolation of daily precipitation over Europe

Angular-distance weighting (ADW) is a common approach for interpolation of an irregular network of meteorological observations to a regular grid. A widely used version of ADW employs the correlation decay distance (CDD) to (1) select stations that should contribute to each grid-point estimate and (2) define the distance component of the station weights. We show, for Europe, that the CDD of daily precipitation varies spatially, as well as by season and synoptic state, and is also anisotropic. However, ADW interpolation using CDDs that varies spatially by season or synoptic state yield only small improvements in interpolation skill, relative to the use of a fixed CDD across the entire domain. If CDDs are optimized through cross validation, a larger improvement in interpolation skill is achieved. Improvements are larger for the determination of the state of precipitation (wet/dry) than for the magnitude. These or other attempts to improve interpolation skill appear to be fundamentally limited by the available station networ

Towards online relational schema transformations

Current relational database systems are ill-equipped for changing the structure of data while the database is in use. This is a real problem for systems for which we expect 24/7 availability, such as telecommunication, payment, and control systems. As a result, developers tend to avoid making changes because of the downtime consequences. The urgency to solve this problem is evident by a multitude of tools developed in industry, such as pt-online-schema-change(1) and oak-online-alter- table(2). Also, MySQL recently added limited support for online schema changes(3).\ud \ud Contributions: We want to draw the attention of the database community to the problem of online schema changes. We have defined requirements for online schema change mechanisms, and we have experimentally investigated existing solutions. Our results show that current solutions are unsatisfactory for complex schema changes. We propose lazy schema changes as a solution.\ud \ud Experimental Setup: To assess the performance and behaviour of existing mechanisms for on- line schema changes, we have developed an experiment based on the standard TPC-C benchmark. For each of the relational schema transformation classes that we have identified, we chose a rep- resentative transformation for the TPC-C schema. We perform the schema change online while the TPC-C benchmark is running, and measure the impact on the TPC-C transaction through- put. We have performed our experiment on PostgreSQL, which does not support online schema changes, MySQL, which supports basic online schema changes, and using pt-online-schema-change on MySQL, as a representative for tools that use triggers to allow online schema changes.\ud \ud Results: We found that existing solutions are inadequate except for the simplest of schema changes. Some single-relation transformations can be performed transactionally and online. How- ever, existing solutions do not allow schema transformations to be composed using transactions. As a result, in complex transformations, intermediate states can be exposed to database programs, which are non-trivial to handle correctly. A secondary problem is that these solutions are much slower than offline transformations, which may not be acceptable for certain applications.\ud \ud Proposal: We propose a more fundamental solution based on lazy schema transformations. The main idea is that schema changes can be described as a view on the existing schema, which can be materialized lazily to perform the schema transformation. The data in the new schema is immedi- ately accessible by computing parts of the view on demand. For a large number of cases we expect that this approach allows schema transformations without any downtime, and with minimal impact on running transactions, while the ACID properties are maintained. Moreover, lazy transforma- tions can naturally be composed as transactions, allowing complex online schema transformations. We are developing an implementation of these ideas based on a persistent functional language

The Impact of Fine-scale Reservoir Geometries on Streamline Flow Patterns in Submarine Lobe Deposits Using Outcrop Analogues from the Karoo Basin

Improved prediction of the recovery of oil-in-place in basin-floor fan reservoirs requires accurate characterisation and modelling of multiscale heterogeneities. The use of outcrop analogues is a key tool to augment this process by documenting and quantifying sedimentary architecture, hierarchy, and sedimentary facies relationships. A 3D geological modelling workflow is presented that tests the impact of fine-scale heterogeneities within basin-floor lobe complexes on reservoir connectivity. Construction of geological models of a basin-floor lobe complex allows realistic depositional architecture and facies distributions to be captured. Additionally, detailed models are constructed from channelised areas within a basin-floor lobe complex. Petrophysical modelling and streamline analysis are employed to test the impact on reservoir connectivity between lobe models with i) vertically-stacked facies with coarsening- and thickening-upwards trends in all locations, and ii) lateral facies changes with dimensions and distributions constrained from outcrop data. The findings show that differences in facies architecture, and in particular lobe-on-lobe amalgamation, have a significant impact on connectivity and macroscopic sweep efficiency, which influence the production results. Channelised lobe areas are less predictable reservoir targets due to uncertainties associated with channel-fill heterogeneities. The use of deterministic sedimentary architecture concepts and facies relationships have proven vital in the accurate modelling of reservoir heterogeneities

<i>C-elegans</i> model identifies genetic modifiers of alpha-synuclein inclusion formation during aging

Inclusions in the brain containing alpha-synuclein are the pathological hallmark of Parkinson's disease, but how these inclusions are formed and how this links to disease is poorly understood. We have developed a &lt;i&gt;C-elegans&lt;/i&gt; model that makes it possible to monitor, in living animals, the formation of alpha-synuclein inclusions. In worms of old age, inclusions contain aggregated alpha-synuclein, resembling a critical pathological feature. We used genome-wide RNA interference to identify processes involved in inclusion formation, and identified 80 genes that, when knocked down, resulted in a premature increase in the number of inclusions. Quality control and vesicle-trafficking genes expressed in the ER/Golgi complex and vesicular compartments were overrepresented, indicating a specific role for these processes in alpha-synuclein inclusion formation. Suppressors include aging-associated genes, such as sir-2.1/SIRT1 and lagr-1/LASS2. Altogether, our data suggest a link between alpha-synuclein inclusion formation and cellular aging, likely through an endomembrane-related mechanism. The processes and genes identified here present a framework for further study of the disease mechanism and provide candidate susceptibility genes and drug targets for Parkinson's disease and other alpha-synuclein related disorders

Het Deltaplan Hoge Zandgronden

In de loop van 2014 worden de Deltabeslissingen genomen. Hoewel deze nog niet definitief zijn, zijn de hoofdlijnen van de opgave duidelijk. Voor het Deltaplan Hoge Zandgronden (DHZ) van het Delta(deel)programma Zoetwater liggen de opgaven op het gebied van watertekorten en -overlast met consequenties voor diverse functies (landbouw, natuur, drinkwater, scheepvaart, industrie, recreatie, stedelijk gebied, bodemdaling en waterveiligheid). Een uitvoeringsprogramma voor deze opgaven is opgesteld, waarbij verschillende partijen betrokken zijn als stakeholders, maar ook als kostendragers. Het huidige Deltaprogramma biedt de kaders voor de nationale inbedding van dit regionale uitvoe-ringsprogramma, maar na de Deltabeslissingen is het nog niet duidelijk hoe de uitvoeringsorganisatie er uit ziet. Het advies van Teisman en Van Buuren (2014) benadrukt het belang van instandhouding van regionale fora voor afstemming, met name ook op het snijvlak van water en ruimte, en als bouw-steen voor een vitaal multilevel governance arrangement. Ook benadrukken zij het belang om uit-voering en strategievorming hand in hand te laten gaan

Monoidal computer III: A coalgebraic view of computability and complexity

Monoidal computer is a categorical model of intensional computation, where many different programs correspond to the same input-output behavior. The upshot of yet another model of computation is that a categorical formalism should provide a much needed high level language for theory of computation, flexible enough to allow abstracting away the low level implementation details when they are irrelevant, or taking them into account when they are genuinely needed. A salient feature of the approach through monoidal categories is the formal graphical language of string diagrams, which supports visual reasoning about programs and computations. In the present paper, we provide a coalgebraic characterization of monoidal computer. It turns out that the availability of interpreters and specializers, that make a monoidal category into a monoidal computer, is equivalent with the existence of a *universal state space*, that carries a weakly final state machine for any pair of input and output types. Being able to program state machines in monoidal computers allows us to represent Turing machines, to capture their execution, count their steps, as well as, e.g., the memory cells that they use. The coalgebraic view of monoidal computer thus provides a convenient diagrammatic language for studying computability and complexity.Comment: 34 pages, 24 figures; in this version: added the Appendi

Recombinant human activated protein C in the treatment of acute respiratory distress syndrome

Rationale: Pulmonary coagulopathy may play a pathogenetic role in acute respiratory distress syndrome (ARDS), by contributing to alveolocapillary inflammation and increased permeability. Recombinant human activated protein C (rh-APC) may inhibit this process and thereby improve patient outcome. Methods: A prospective randomized, saline-controlled, single-blinded clinical trial was performed in the intensive care units of two university hospitals, and patients with ARDS were included within 24 h after meeting inclusion criteria. Intervention: A 4-day course of intravenous rh-APC (24 mcg/kg/h) (n = 33) versus saline (n = 38). Outcomes: The primary outcome parameter was the pulmonary leak index (PLI) of 67Gallium-transferrin as a measure of alveolocapillary permeability and secondary outcomes were disease severity scores and ventilator-free days, among others. Results: Baseline characteristics were similar; in 87% of patients the PLI was above normal and in 90% mechanical or noninvasive ventilation was instituted at a median lung injury score of 2.5. There was no evidence that Rh-APC treatment affected the PLI or attenuated lung injury and sequential organ failure assessment scores. Mean ventilator-free days amounted to 14 (rh-APC) and 12 days (saline, P = 0.35). 28-day mortality was 6% in rh-APC- and 18% in saline-treated patients (P = 0.12). There was no difference in bleeding events. The study was prematurely discontinued because rh-APC was withdrawn from the market. Conclusion: There is no evidence that treatment with intravenous rh-APC during 4 days for infectious or inflammatory ARDS ameliorates increased alveolocapillary permeability or the clinical course of ARDS patients. We cannot exclude underpowering. Trial Registration: Nederlands Trial Registe

Inner autoequivalences in general and those of monoidal categories in particular

We develop a general theory of (extended) inner autoequivalences of objects of any 2-category, generalizing the theory of isotropy groups to the 2-categorical setting. We show how dense subcategories let one compute isotropy in the presence of binary coproducts, unifying various known one-dimensional results and providing tractable computational tools in the two-dimensional setting. In particular, we show that the isotropy 2-group of a monoidal category coincides with its Picard 2-group, i.e., the 2-group on its weakly invertible objects

Trans-eQTLs Reveal That Independent Genetic Variants Associated with a Complex Phenotype Converge on Intermediate Genes, with a Major Role for the HLA

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Early intravenous unfractionated heparin and outcome in acute lung injury and acute respiratory distress syndrome: a retrospective propensity matched cohort study.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: Acute lung injury (ALI) is characterized by a pro-coagulant state. Heparin is an anticoagulant with anti-inflammatory properties. Unfractionated heparin has been found to be protective in experimental models of ALI. We hypothesized that an intravenous therapeutic dose of unfractionated heparin would favorably influence outcome of critically ill patients diagnosed with ALI. METHODS: Patients admitted to the Intensive Care Unit (ICU) of a tertiary referral center in the Netherlands between November 2004 and October 2007 were screened. Patients who developed ALI (consensus definition) were included. In this cohort, the impact of heparin use on mortality was assessed by logistic regression analysis in a propensity matched case-control design. RESULTS: Of 5,561 admitted patients, 2,138 patients had a length of stay > 48 hours, of whom 723 were diagnosed with ALI (34%), of whom 164 received intravenous heparin. In a propensity score adjusted logistic regression analysis, heparin use did not influence 28-day mortality (odds ratio 1.23 [confidence interval 95% 0.80-1.89], nor did it affect ICU length of stay. CONCLUSIONS: Administration of therapeutic doses of intravenous unfractionated heparin was not associated with reduced mortality in critically ill patients diagnosed with ALI. Heparin treatment did not increase transfusion requirements. These results may help in the design of prospective trials evaluating the use of heparin as adjunctive treatment for ALI