A parallel portfolio SAT solver with lockless physical clause sharing

Since multi-core architectures have become well-established the enquiry for parallel SAT solvers has drastically increased. Meanwhile, several successful SAT solvers have been presented that can be run in parallel mode. However, there are only a few solvers that use the shared memory architectures for physical clause sharing. In this paper we present a parallel SAT solver that allows for sharing clauses between several threads logically and physically. Yet any thread is still able to keep its own set of clauses. We show how physical clause sharing can be used to propagate one thread's improvements on the clause database to all solving threads. Despite the extensive sharing of data our solver does not require any operating system lock

Ökonomische Krise als Charakterfrage: die Manager-Schelte

In recent discussions in Germany managers of big companies were blamed to be unable, to be creedy, to be not honest. Three well known examples of such critic are discussed. It is shown that behind this critic is the imagination of capitalism as a pretty good social system if all actors behave well

Visible light is a better co-inducer of apoptosis for curcumin-treated human melanoma cells than UVA

Curcumin attracts worldwide scientific interest due to its anti-proliferative and apoptosis inducing effects on different tumor cells at concentrations ranging from 10 to 150 µM (3.7–55 µg/ml). Unfortunately, because of a low oral bioavailability, only low and pharmacologically ineffective serum levels are achievable. In this study, an alternative treatment concept consisting of low concentration curcumin (0.2–5 µg/ml) and irradiation with UVA or visible light (VL) has been tested. The experimental results show clearly that this treatment decreases the proliferation and the viability of human melanoma cells while the cell membrane integrity remains intact. We identified the onset of apoptosis characterized by typical markers such as active caspases 8, 9 and 3 as well as DNA fragmentation accompanied by the loss of cell adhesion. The mitochondrial apoptosis signaling pathway is predominant due to an early activation of caspase-9. The present data indicate a higher efficacy of a combination of curcumin and VL than curcumin and UVA. Reduced effects as a result of light absorption by heavily pigmented skin are unlikely if VL is used. These results indicate that a combination of curcumin and light irradiation may be a useful additional therapy in the treatment of malignant disease

Spinning Fast Iterative Data Flows

Parallel dataflow systems are a central part of most analytic pipelines for big data. The iterative nature of many analysis and machine learning algorithms, however, is still a challenge for current systems. While certain types of bulk iterative algorithms are supported by novel dataflow frameworks, these systems cannot exploit computational dependencies present in many algorithms, such as graph algorithms. As a result, these algorithms are inefficiently executed and have led to specialized systems based on other paradigms, such as message passing or shared memory. We propose a method to integrate incremental iterations, a form of workset iterations, with parallel dataflows. After showing how to integrate bulk iterations into a dataflow system and its optimizer, we present an extension to the programming model for incremental iterations. The extension alleviates for the lack of mutable state in dataflows and allows for exploiting the sparse computational dependencies inherent in many iterative algorithms. The evaluation of a prototypical implementation shows that those aspects lead to up to two orders of magnitude speedup in algorithm runtime, when exploited. In our experiments, the improved dataflow system is highly competitive with specialized systems while maintaining a transparent and unified dataflow abstraction.Comment: VLDB201

Prevalence and characteristics of non-O157 shiga toxin-producing Escherichia coli (STEC) and Escherichia coli O157 in fattening pigs at slaughter in Switzerland

Feacal samples from 630 slaughtered healthy pigs were examined with the aim: (i) to monitor the shedding of non-O157 STEC and E. coli O157; (ii) to further characterize isolated strains; and (iii) to discuss the results obtained with their relevance to food safety. The percentage of the 630 samples testing positive for STEC by polymerase chain reaction was 22.2%. The 32 isolated stx positive strains (31 sorbitol-positive) belonged to non-O157 STEC and comprised ten serotypes. Stx1, stx2, and both toxin genes were detected in 3%, 97%, and 0% of strains. Among stx2-positive strains, 29 were positive for stx2e, one for stx2/stx2e, and one for stx2c/stx2e. The percentage of the 630 samples testing positive for E. coli O157 by polymerase chain reaction was 7.5%. The 31 isolated rfbE PCR positive strains tested negative for stx genes. However, four strains harbored eae and were classified as EPEC

Error-related brain activity as a transdiagnostic endophenotype for obsessive-compulsive disorder, anxiety and substance use disorder

Background Increased neural error-signals have been observed in obsessive-compulsive disorder (OCD), anxiety disorders, and inconsistently in depression. Reduced neural error-signals have been observed in substance use disorders (SUD). Thus, alterations in error-monitoring are proposed as a transdiagnostic endophenotype. To strengthen this notion, data from unaffected individuals with a family history for the respective disorders are needed. Methods The error-related negativity (ERN) as a neural indicator of error-monitoring was measured during a flanker task from 117 OCD patients, 50 unaffected first-degree relatives of OCD patients, and 130 healthy comparison participants. Family history information indicated, that 76 healthy controls were free of a family history for psychopathology, whereas the remaining had first-degree relatives with depression (n = 28), anxiety (n = 27), and/or SUD (n = 27). Results Increased ERN amplitudes were found in OCD patients and unaffected first-degree relatives of OCD patients. In addition, unaffected first-degree relatives of individuals with anxiety disorders were also characterized by increased ERN amplitudes, whereas relatives of individuals with SUD showed reduced amplitudes. Conclusions Alterations in neural error-signals in unaffected first-degree relatives with a family history of OCD, anxiety, or SUD support the utility of the ERN as a transdiagnostic endophenotype. Reduced neural error-signals may indicate vulnerability for under-controlled behavior and risk for substance use, whereas a harm- or error-avoidant response style and vulnerability for OCD and anxiety appears to be associated with increased ERN. This adds to findings suggesting a common neurobiological substrate across psychiatric disorders involving the anterior cingulate cortex and deficits in cognitive control

Der ökonomische Determinismus – neu betrachtet

This article revisits the claim that the social relations of production determine, at least in the last instance, the overall nature and dynamic of social formations. The claim in its original form is often misunderstood, its later justifications are generally weak, and efforts to improve it are mostly unconvincing. An alternative interpretation is presented that identifies four complementary meanings of economic determinism that are all consistent with historical materialism. The fourth meaning draws on the relatively new concept of ‘ecological dominance’ but it was anticipated, the author argues, in certain arguments of Marx and Engels themselves

Rapid determination of general cell status, cell viability, and optimal harvest time in eukaryotic cell cultures by impedance flow cytometry

The determination of cell viability is essential to many areas of life sciences and biotechnology. Typically, cell viability measurements are based on the optical analysis of stained cells, which requires additional labeling steps and is hard to implement online. Frequency-dependent impedance flow cytometry (IFC) provides a label-free, fast, and reliable alternative to determine cell viability at the single cell level based on the Coulter principle. Here, we describe the application of IFC to eukaryotic cell cultures and compare the results to commonly used staining methods. Yeast cell parameters were assessed in normal and heat-inactivated cells as well as in alcoholic fermentation and long-term batch cultures providing a precise and fast determination of the cell viability and further quantitative measures of the cell culture status. As an important new application, we have investigated recombinant protein production in the widely used baculovirus insect cell expression system. The IFC analysis revealed the presence of a subpopulation of cells, which correlates with the protein expression yield, but it is not detectable with conventional optical cell counters. We tentatively identify this subpopulation as cells in the late phase of infection. Their detection can serve as a predictor for the optimal time point of harvest. The IFC technique should be generally applicable to many eukaryotic cell cultures in suspension, possibly also implemented online