245 research outputs found

    Awakening the architectural experience: how to teach the dialogical knowledge of architects

    Get PDF
    Learning processes in architecture have always been a complex and difficult research field; the specific qualities of architectural education from childhood to adulthood are far from to be really known. We will present some studies, some coming from works with children in primary school and some from the university level in the school of architecture in Barcelona. We will analyze with some examples how the dialogical dimensions of the knowledge of architects can be developed, underdeveloped and even destroyed in education. Some conclusions will intend to uncover how to bridge the gap between practice and theory in architectural education, and then we can immediately understand that this gap has been produced by the wrong assumption that learning and design architectural processes can develop out of their social and cultural-geographic circumstances, in an abstract and apolitical place, where the relationships between experience and reflection can never exist

    Saiph, a domain specific language for computational fluid dynamics simulations

    Get PDF
    Nowadays, High-Performance Computing (HPC) is assuming an increasingly central role in scientific research while computer architectures are becoming more and more hetero-geneous and using different parallel programming models and techniques. Under this scenario, the only way to successfully exploit an HPC system requires that computer and domain scientists work closely towards producing applications to solve domain problems, ensuring productivity and performance at the same time. Facing such purpose, Saiph is a Domain Specific Language designed to ease the task of solving couple and uncouple Partial Differential Equations (PDE’s), with a primary focusing on Computational Fluid Dynamics (CFD) applications. Saiph allows to model complex physical phenomena featured by PDE’s, easing the use of numerical methods and optimizations on different computer architectures to the users

    Functional dissection of the ash2 and ash1 transcriptomes provides insights into the transcriptional basis of wing phenotypes and reveals conserved protein interactions

    Get PDF
    Analysis of the gene expression profiles of wing imaginal discs from ash2 and ash1 mutants shows that they are highly similar, supporting a model in which they act together to maintain stable states of transcription

    Adaptive and architecture-independent task granularity for recursive applications

    Get PDF
    In the last few decades, modern applications have become larger and more complex. Among the users of these applications, the need to simplify the process of identifying units of work increased as well. With the approach of tasking models, this want has been satisfied. These models make scheduling units of work much more user-friendly. However, with the arrival of tasking models, came granularity management. Discovering an application’s optimal granularity is a frequent and sometimes challenging task for a wide range of recursive algorithms. Often, finding the optimal granularity will cause a substantial increase in performance. With that in mind, the quest for optimality is no easy task. Many aspects have to be considered that are directly related to lack or excess of parallelism in applications. There is no general solution as the optimal granularity depends on both algorithm and system characteristics. One commonly used method to find an optimal granularity consists in experimentally tuning an application with different granularities until an optimal is found. This paper proposes several heuristics which, combined with the appropriate monitoring techniques, allow a runtime system to automatically tune the granularity of recursive applications. The solution is independent of the architecture, execution environment or application being tested. A reference implementation in OmpSs—a task-parallel programming model—shows the programmability, ease of use and competitive performance of the proposed solution. Results show that the proposed solution is able to achieve, for any scenario, at least 75% of the performance of optimally tuned applications.This work has been supported by the Spanish Ministry of Science and Innovation (contract TIN2015-65316), the grant SEV-2015-0493 of Severo Ochoa Program awarded by the Spanish Government, and by Generalitat de Catalunya (contract 2014-SGR-1051)Peer ReviewedPostprint (author's final draft

    Worksharing tasks: An efficient way to exploit irregular and fine-grained loop parallelism

    Get PDF
    Shared memory programming models usually provide worksharing and task constructs. The former relies on the efficient fork-join execution model to exploit structured parallelism; while the latter relies on fine-grained synchronization among tasks and a flexible data-flow execution model to exploit dynamic, irregular, and nested parallelism. On applications that show both structured and unstructured parallelism, both worksharing and task constructs can be combined. However, it is difficult to mix both execution models without penalizing the data-flow execution model. Hence, on many applications structured parallelism is also exploited using tasks to leverage the full benefits of a pure data-flow execution model. However, task creation and management might introduce a non-negligible overhead that prevents the efficient exploitation of fine-grained structured parallelism, especially on many-core processors. In this work, we propose worksharing tasks. These are tasks that internally leverage worksharing techniques to exploit fine-grained structured loop-based parallelism. The evaluation shows promising results on several benchmarks and platforms.This work is supported by the Spanish Ministerio de Ciencia, Innovacion y Universidades (TIN2015-65316-P), by the Generalitat de Catalunya (2014-SGR-1051) and by the European Union’s Seventh Framework Programme (FP7/2007-2013) and the H2020 funding framework under grant agreement no. H2020-FETHPC-754304 (DEEP-EST).Peer ReviewedPostprint (author's final draft

    Extending the OpenCHK Model with Advanced Checkpoint Features

    Full text link
    One of the major challenges in using extreme scale systems efficiently is to mitigate the impact of faults. Application-level checkpoint/restart (CR) methods provide the best trade-off between productivity, robustness, and performance. There are many solutions implementing CR at the application level. They all provide advanced I/O capabilities to minimize the overhead introduced by CR. Nevertheless, there is still room for improvement in terms of programmability and flexibility, because end-users must manually serialize and deserialize application state using low-level APIs, modify the flow of the application to consider restarts, or rewrite CR code whenever the backend library changes. In this work, we propose a set of compiler directives and clauses that allow users to specify CR operations in a simple way. Our approach supports the common CR features provided by all the CR libraries. However, it can also be extended to support advanced features that are only available in some CR libraries, such as differential checkpointing, the use of HDF5 format, and the possibility of using fault-tolerance-dedicated threads. The result of our evaluation revealed a high increase in programmability. On average, we reduced the number of lines of code by 71%, 94%, and 64% for FTI, SCR, and VeloC, respectively, and no additional overhead was perceived using our solution compared to using the backend libraries directly. Finally, portability is enhanced because our programming model allows the use of any backend library without changing any code

    Mapping direct N2O emissions from peri-urban agriculture : the case of the Metropolitan Area of Barcelona

    Get PDF
    Unidad de excelencia María de Maeztu CEX2019-000940-MAltres ajuts: acords transformatius de la UABGeographically explicit datasets reflecting local management of crops are needed to help improve direct nitrous oxide (N2O) emission inventories. Yet, the lack of geographically explicit datasets of relevant factors influencing the emissions make it difficult to estimate them in such way. Particularly, for local peri-urban agriculture, spatially explicit datasets of crop type, fertilizer use, irrigation, and emission factors (EFs) are hard to find, yet necessary for evaluating and promoting urban self-sufficiency, resilience, and circularity. We spatially distribute these factors for the peri-urban agriculture in the Metropolitan Area of Barcelona (AMB) and create N2O emissions maps using crop-specific EFs as well as Tier 1 IPCC EFs for comparison. Further, the role of the soil types is qualitatively assessed. When compared to Tier 1 IPCC EFs, we find 15% more emissions (i.e. 7718 kg N2O-N year−1) than those estimated with the crop-specific EFs (i.e. 6533 kg N2O-N year−1) for the entire AMB. Emissions for most rainfed crop areas like cereals (e.g. oat and barley) and non-citric fruits (e.g. cherries and peaches), which cover 24% and 13% of AMB's peri-urban agricultural area respectively, are higher with Tier 1 EF. Conversely, crop-specific EFs estimate higher emissions for irrigated horticultural crops (e.g. tomato, artichoke) which cover 33% of AMB's peri-urban agricultural area and make up 70% of the total N2O emissions (4588 kg N2O-N year−1 using crop-specific EFs). Mapping the emissions helps evaluate spatial variability of key factors such as fertilizer use and irrigation of crops but carry uncertainties due to downscaling regional data to represent urban level data gaps. It also highlighted core emitting areas. Further the usefulness of the outputs on mitigation, sustainability and circularity studies are briefly discussed

    Transcriptomic characterization of the larval stage in gilthead seabream (Sparus aurata) by 454 pyrosequencing

    Get PDF
    Gilthead seabream (Sparus aurata) is a teleost belonging to the family Sparidae with a high economical relevance in the Mediterranean countries. Although genomic tools have been developed in this species in order to investigate its physiology at the molecular level and consequently its culture, genomic information on post-embryonic development is still scarce. In this study, we have investigated the transcriptome of a marine teleost during the larval stage (from hatching to 60 days after hatching) by the use of 454 pyrosequencing technology. We obtained a total of 68,289 assembled contigs, representing putative transcripts, belonging to 54,606 different clusters. Comparison against all S. aurata expressed sequenced tags (ESTs) from the NCBI database revealed that up to 34,722 contigs, belonging to about 61% of gene clusters, are sequences previously not described. Contigs were annotated through an iterative Blast pipeline by comparison against databases such as NCBI RefSeq from Danio rerio, SwissProt or NCBI teleost ESTs. Our results indicate that we have enriched the number of annotated sequences for this species by more than 50% compared with previously existing databases for the gilthead seabream. Gene Ontology analysis of these novel sequences revealed that there is a statistically significant number of transcripts with key roles in larval development, differentiation, morphology, and growth. Finally, all information has been made available online through user-friendly interfaces such as GBrowse and a Blast server with a graphical frontend

    Thermal evolution of gene expression profiles in Drosophila subobscura

    Get PDF
    BACKGROUND: Despite its pervasiveness, the genetic basis of adaptation resulting in variation directly or indirectly related to temperature (climatic) gradients is poorly understood. By using 3-fold replicated laboratory thermal stocks covering much of the physiologically tolerable temperature range for the temperate (i.e., cold tolerant) species Drosophila subobscura we have assessed whole-genome transcriptional responses after three years of thermal adaptation, when the populations had already diverged for inversion frequencies, pre-adult life history components, and morphological traits. Total mRNA from each population was compared to a reference pool mRNA in a standard, highly replicated two-colour competitive hybridization experiment using cDNA microarrays. RESULTS: A total of 306 (6.6%) cDNA clones were identified as 'differentially expressed' (following a false discovery rate correction) after contrasting the two furthest apart thermal selection regimes (i.e., 13°C vs . 22°C), also including four previously reported candidate genes for thermotolerance in Drosophila (Hsp26, Hsp68, Fst, and Treh). On the other hand, correlated patterns of gene expression were similar in cold- and warm-adapted populations. Analysis of functional categories defined by the Gene Ontology project point to an overrepresentation of genes involved in carbohydrate metabolism, nucleic acids metabolism and regulation of transcription among other categories. Although the location of differently expressed genes was approximately at random with respect to chromosomes, a physical mapping of 88 probes to the polytene chromosomes of D. subobscura has shown that a larger than expected number mapped inside inverted chromosomal segments. CONCLUSION: Our data suggest that a sizeable number of genes appear to be involved in thermal adaptation in Drosophila, with a substantial fraction implicated in metabolism. This apparently illustrates the formidable challenge to understanding the adaptive evolution of complex trait variation. Furthermore, some clustering of genes within inverted chromosomal sections was detected. Disentangling the effects of inversions will be obviously required in any future approach if we want to identify the relevant candidate genes
    • …
    corecore