118 research outputs found
Only Aggressive Elephants are Fast Elephants
Yellow elephants are slow. A major reason is that they consume their inputs
entirely before responding to an elephant rider's orders. Some clever riders
have trained their yellow elephants to only consume parts of the inputs before
responding. However, the teaching time to make an elephant do that is high. So
high that the teaching lessons often do not pay off. We take a different
approach. We make elephants aggressive; only this will make them very fast. We
propose HAIL (Hadoop Aggressive Indexing Library), an enhancement of HDFS and
Hadoop MapReduce that dramatically improves runtimes of several classes of
MapReduce jobs. HAIL changes the upload pipeline of HDFS in order to create
different clustered indexes on each data block replica. An interesting feature
of HAIL is that we typically create a win-win situation: we improve both data
upload to HDFS and the runtime of the actual Hadoop MapReduce job. In terms of
data upload, HAIL improves over HDFS by up to 60% with the default replication
factor of three. In terms of query execution, we demonstrate that HAIL runs up
to 68x faster than Hadoop. In our experiments, we use six clusters including
physical and EC2 clusters of up to 100 nodes. A series of scalability
experiments also demonstrates the superiority of HAIL.Comment: VLDB201
About the implantation process of mobile computing in AEC
The AEC industry is conscious of the potentials arising from the usage of mobile computer systems to increase productivity by streamlining their business processes. Discussions are no longer on whether or not to use a mobile computer solution, but rather, on how it should be used. However, the implantation process of this new technology in Architecture, Engineering and Construction (AEC) and Facility Management (FM) practise is very slow and should be improved. One way to encourage and ease the usage of mobile computer systems in AEC is a more process-oriented usability and context appropriateness of mobile computer solutions. Context-sensitivity is defined as a crucial feature to be taken into account for further research in the area of Mobile Computing. Context-sensitive, mobile IT-solutions depend on two features: (1) flexible definitions of (construction) processes describing the context and (2) tools for flexible, multi-dimensional information management representing the context. It is on this premise that the authors propose the n-dimensional data management approach for the implementation of mobile computing solutions. In this paper, we analyse working scenarios in the AEC and FM sector, defining context aspects which are transformed and formalized as dimension hierarchies of the envisaged context model
Teaching Disciplines "History of Russia" and "Country Studies" to Foreign Students: Problems and Solutions
The present paper is focused on the problem of teaching foreign students such disciplines as "Country studies" and "History of Russia", which appear to be compulsory for the international students, getting higher education in Russia. Studying these disciplines, students meet some difficulties due to various reasons, beginning with poor knowledge of Russian language and ending with ethical problems. A lecturer needs to cross this socio-cultural and linguistic barrier and find solutions in order to give the full information in accordance with the educational working program. The research has an applied character. It is based on the sociological survey conducted among the foreign students of National Research Tomsk Polytechnic University. The aim of the paper is to demonstrate real difficulties of students and lecturers at studying and teaching disciplines "Country studies" and "History of Russia" and to offer solutions for overcoming these problems
Highly efficient passive Tesla valves for microfluidic applications
A multistage optimization method is developed yielding Tesla valves that are efficient even at low flow rates, characteristic, e.g., for almost all microfluidic systems, where passive valves have intrinsic advantages over active ones. We report on optimized structures that show a diodicity of up to 1.8 already at flow rates of 20 μl s−1 corresponding to a Reynolds number of 36. Centerpiece of the design is a topological optimization based on the finite element method. It is set-up to yield easy-to-fabricate valve structures with a small footprint that can be directly used in microfluidic systems. Our numerical two-dimensional optimization takes into account the finite height of the channel approximately by means of a so-called shallow-channel approximation. Based on the three-dimensionally extruded optimized designs, various test structures were fabricated using standard, widely available microsystem manufacturing techniques. The manufacturing process is described in detail since it can be used for the production of similar cost-effective microfluidic systems. For the experimentally fabricated chips, the efficiency of the different valve designs, i.e., the diodicity defined as the ratio of the measured pressure drops in backward and forward flow directions, respectively, is measured and compared to theoretical predictions obtained from full 3D calculations of the Tesla valves. Good agreement is found. In addition to the direct measurement of the diodicities, the flow profiles in the fabricated test structures are determined using a two-dimensional microscopic particle image velocimetry (μPIV) method. Again, a reasonable good agreement of the measured flow profiles with simulated predictions is observed
Digitales Video
Elektronische Dokumente werden immer häufiger durch zeitbasierte Medienobjekte wie z.B. Videoclips angereichert. Selbst im WWW sind mittlerweile Videos komfortabel durch Streamingtechnologie verfügbar. Rechnergestützte Videoschnittlösungen und Telekonferenzsysteme sind zudem weitere Einsatzfelder für digitale Videosequenzen. Aufgrund beschränkter Ressourcen ist Kompression aber weiterhin ein entscheidender Einsatzfaktor
ADAM17 Inhibition Increases the Impact of Cisplatin Treatment in Ovarian Cancer Spheroids
Chemotherapy resistance is a major challenge in ovarian cancer (OvCa). Thus, novel treatment combinations are highly warranted. However, many promising drug candidates tested in two-dimensional (2D) cell culture have not proved successful in the clinic. For this reason, we analyzed our drug combination not only in monolayers but also in three-dimensional (3D) tumor spheroids. One potential therapeutic target for OvCa is A disintegrin and metalloprotease 17 (ADAM17). ADAM17 can be activated by chemotherapeutics, which leads to enhanced tumor growth due to concomitant substrate cleavage. Therefore, blocking ADAM17 during chemotherapy may overcome resistance. Here, we tested the effect of the ADAM17 inhibitor GW280264X in combination with cisplatin on ovarian cancer cells in 2D and 3D. In 2D, the effect on five cell lines was analyzed with two readouts. Three of these cell lines formed dense aggregates or spheroids (HEY, SKOV-3, and OVCAR-8) in 3D and the treatment effect was analyzed with a multicontent readout (cytotoxicity, viability, and caspase3/7 activation). We tested the combined therapy on tumor spheroids derived from primary patient cells. In 2D, we found a significant reduction in the half minimal (50%) inhibitory concentration (IC50) value of the combined treatment (GW280264X plus cisplatin) in comparison with cisplatin monotherapy in all five cell lines with both 2D readout assays (viability and caspase activation). In contrast, the combined treatment only showed an IC50 reduction in HEY and OVCAR-8 3D tumor spheroid models using caspase3/7 activity or CelltoxTM Green as the readout. Finally, we found an improved effect of GW280264X with cisplatin in tumor spheroids derived from patient samples. In summary, we demonstrate that ADAM17 inhibition is a promising treatment strategy in ovarian cancer
Poplar Extrafloral Nectaries: Two Types, Two Strategies of Indirect Defenses against Herbivores
Duloxetine Inhibits Effects of MDMA (“Ecstasy") In Vitro and in Humans in a Randomized Placebo-Controlled Laboratory Study
This study assessed the effects of the serotonin (5-HT) and norepinephrine (NE) transporter inhibitor duloxetine on the effects of 3,4–methylenedioxymethamphetamine (MDMA, ecstasy) in vitro and in 16 healthy subjects. The clinical study used a double-blind, randomized, placebo-controlled, four-session, crossover design. In vitro, duloxetine blocked the release of both 5-HT and NE by MDMA or by its metabolite 3,4-methylenedioxyamphetamine from transmitter-loaded human cells expressing the 5-HT or NE transporter. In humans, duloxetine inhibited the effects of MDMA including elevations in circulating NE, increases in blood pressure and heart rate, and the subjective drug effects. Duloxetine inhibited the pharmacodynamic response to MDMA despite an increase in duloxetine-associated elevations in plasma MDMA levels. The findings confirm the important role of MDMA-induced 5-HT and NE release in the psychotropic effects of MDMA. Duloxetine may be useful in the treatment of psychostimulant dependence
A randomized multi-center phase II trial of the angiogenesis inhibitor Cilengitide (EMD 121974) and gemcitabine compared with gemcitabine alone in advanced unresectable pancreatic cancer
BACKGROUND: Anti-angiogenic treatment is believed to have at least cystostatic effects in highly vascularized tumours like pancreatic cancer. In this study, the treatment effects of the angiogenesis inhibitor Cilengitide and gemcitabine were compared with gemcitabine alone in patients with advanced unresectable pancreatic cancer. METHODS: A multi-national, open-label, controlled, randomized, parallel-group, phase II pilot study was conducted in 20 centers in 7 countries. Cilengitide was administered at 600 mg/m(2 )twice weekly for 4 weeks per cycle and gemcitabine at 1000 mg/m(2 )for 3 weeks followed by a week of rest per cycle. The planned treatment period was 6 four-week cycles. The primary endpoint of the study was overall survival and the secondary endpoints were progression-free survival (PFS), response rate, quality of life (QoL), effects on biological markers of disease (CA 19.9) and angiogenesis (vascular endothelial growth factor and basic fibroblast growth factor), and safety. An ancillary study investigated the pharmacokinetics of both drugs in a subset of patients. RESULTS: Eighty-nine patients were randomized. The median overall survival was 6.7 months for Cilengitide and gemcitabine and 7.7 months for gemcitabine alone. The median PFS times were 3.6 months and 3.8 months, respectively. The overall response rates were 17% and 14%, and the tumor growth control rates were 54% and 56%, respectively. Changes in the levels of CA 19.9 went in line with the clinical course of the disease, but no apparent relationships were seen with the biological markers of angiogenesis. QoL and safety evaluations were comparable between treatment groups. Pharmacokinetic studies showed no influence of gemcitabine on the pharmacokinetic parameters of Cilengitide and vice versa. CONCLUSION: There were no clinically important differences observed regarding efficacy, safety and QoL between the groups. The observations lay in the range of other clinical studies in this setting. The combination regimen was well tolerated with no adverse effects on the safety, tolerability and pharmacokinetics of either agent
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