S-Net for multi-memory multicores

Copyright ACM, 2010. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in Proceedings of the 5th ACM SIGPLAN Workshop on Declarative Aspects of Multicore Programming: http://doi.acm.org/10.1145/1708046.1708054S-Net is a declarative coordination language and component technology aimed at modern multi-core/many-core architectures and systems-on-chip. It builds on the concept of stream processing to structure dynamically evolving networks of communicating asynchronous components. Components themselves are implemented using a conventional language suitable for the application domain. This two-level software architecture maintains a familiar sequential development environment for large parts of an application and offers a high-level declarative approach to component coordination. In this paper we present a conservative language extension for the placement of components and component networks in a multi-memory environment, i.e. architectures that associate individual compute cores or groups thereof with private memories. We describe a novel distributed runtime system layer that complements our existing multithreaded runtime system for shared memory multicores. Particular emphasis is put on efficient management of data communication. Last not least, we present preliminary experimental data

Allosteric Activation of the Par-6 PDZ Via a Partial Unfolding Transition

Proteins exist in a delicate balance between the native and unfolded states, where thermodynamic stability may be sacrificed to attain the flexibility required for efficient catalysis, binding, or allosteric control. Partition-defective 6 (Par-6) regulates the Par polarity complex by transmitting a GTPase signal through the Cdc42/Rac interaction binding PSD-95/Dlg/ZO-1 (CRIB-PDZ) module that alters PDZ ligand binding. Allosteric activation of the PDZ is achieved by local rearrangement of the L164 and K165 side chains to stabilize the interdomain CRIB:PDZ interface and reposition a conserved element of the ligand binding pocket. However, microsecond to millisecond dynamics measurements revealed that L164/K165 exchange requires a larger rearrangement than expected. The margin of thermodynamic stability for the PDZ domain is modest (∼3 kcal/mol) and further reduced by transient interactions with the disordered CRIB domain. Measurements of local structural stability revealed that tertiary contacts within the PDZ are disrupted by a partial unfolding transition that enables interconversion of the L/K switch. The unexpected participation of partial PDZ unfolding in the allosteric mechanism of Par-6 suggests that native-state unfolding may be essential for the function of other marginally stable proteins

On the soft X-ray spectrum of cooling flows

Strong evidence for cooling flows has been found in low resolution X-ray imaging and spectra of many clusters of galaxies. However high resolution X-ray spectra of several clusters from the Reflection Grating Spectrometer (RGS) on XMM-Newton now show a soft X-ray spectrum inconsistent with a simple cooling flow. The main problem is a lack of the emission lines expected from gas cooling below 1--2 keV. Lines from gas at about 2--3 keV are observed, even in a high temperature cluster such as A 1835, indicating that gas is cooling down to about 2--3 keV, but is not found at lower temperatures. Here we discuss several solutions to the problem; heating, mixing, differential absorption and inhomogeneous metallicity. Continuous or sporadic heating creates further problems, including the targetting of the heat at the cooler gas and also the high total energy required. So far there is no clear observational evidence for widespread heating, or shocks, in cluster cores, except in radio lobes which occupy only part of the volume. The implied ages of cooling flows are short, at about 1 Gyr. Mixing. or absorption, of the cooling gas are other possibilities. Alternatively, if the metals in the intracluster medium are not uniformly spread but are clumped, then little line emission is expected from the gas cooling below 1 keV. The low metallicity part cools without line emission whereas the strengths of the soft X-ray lines from the metal-rich gas depend on the mass fraction of that gas and not on the abundance, since soft X-ray line emission dominates the cooling function below 2 keV.Comment: 5 pages, with 2 figures, submitted to MNRA

Analytical review of passive mass transfer of water vapor in a space suit

Engineering study and analysis of water vapor mass transfer in space sui

Evaluation of bistable systems versus matched filters in detecting bipolar pulse signals

This paper presents a thorough evaluation of a bistable system versus a matched filter in detecting bipolar pulse signals. The detectability of the bistable system can be optimized by adding noise, i.e. the stochastic resonance (SR) phenomenon. This SR effect is also demonstrated by approximate statistical detection theory of the bistable system and corresponding numerical simulations. Furthermore, the performance comparison results between the bistable system and the matched filter show that (a) the bistable system is more robust than the matched filter in detecting signals with disturbed pulse rates, and (b) the bistable system approaches the performance of the matched filter in detecting unknown arrival times of received signals, with an especially better computational efficiency. These significant results verify the potential applicability of the bistable system in signal detection field.Comment: 15 pages, 9 figures, MikTex v2.

Anterosuperior Glenoid Impingement Syndrome

Anterosuperior glenoid impingement is a well documented cause of shoulder pain. It occurs when there is deep tearing of the subscapularis, with fibers becoming embedded between the anterosuperior glenoid and humeral head. To our knowledge, this has not been described in radiologic literature and we present MRI findings depicting this entit

Forest resource information system, phase 3

There are no author-identified significant results in this report

Cytological Evidence that Alternative Transposition by Ac Elements Causes Reciprocal Translocations and Inversions in Zea mays L.

McClintock discovered the first transposable element system, the Ac/Ds system in maize. She also reported that the Ac/Ds system could cause chromosome breakage and chromosome aberrations; however, the underlying mechanism was not known. Here, we recovered reciprocal translocations and inversions that were produced by alternative transposition in maize lines containing closely linked Ac transposable element termini. The cytological breakpoints of 7 reciprocal translocations and 2 pericentric inversions were determined by cytological analysis in this study

An absorption spectrum amplifier for determining gas composition

Compositions of gas samples are frequently studied by laser absorption spectroscopy. Sensitivity is improved by two orders of magnitude when absorption cell is placed inside an organic-dye laser cavity

From Helplessness To Hope: The Seminal Career Of Martin Seligman

Provides a background to the history of research on learned helplessness and learned optimism, as well as M. Seligman\u27s own involvement in these areas. The development of research in this area also illustrates two other important lessons in how science actually proceeds. First, it is often difficult to predict at the outset where research will lead. Work on learned helplessness began in the animal laboratory and for several years was directed at deep theoretical issues in the psychology of learning and not at depression, academic achievement, and other significant human phenomenon. And second, the history of learned helplessness research demonstrates the continuity between basic and applied research in the way that it has moved effortlessly between fundamental issues in learning, cognition, and motivation on the one hand, and attempts to deal with problems of human adaptation and obstacles to achievement of human potential on the other