342 research outputs found
RETROSPECTIVE: Corona: System Implications of Emerging Nanophotonic Technology
The 2008 Corona effort was inspired by a pressing need for more of
everything, as demanded by the salient problems of the day. Dennard scaling was
no longer in effect. A lot of computer architecture research was in the
doldrums. Papers often showed incremental subsystem performance improvements,
but at incommensurate cost and complexity. The many-core era was moving
rapidly, and the approach with many simpler cores was at odds with the better
and more complex subsystem publications of the day. Core counts were doubling
every 18 months, while per-pin bandwidth was expected to double, at best, over
the next decade. Memory bandwidth and capacity had to increase to keep pace
with ever more powerful multi-core processors. With increasing core counts per
die, inter-core communication bandwidth and latency became more important. At
the same time, the area and power of electrical networks-on-chip were
increasingly problematic: To be reliably received, any signal that traverses a
wire spanning a full reticle-sized die would need significant equalization,
re-timing, and multiple clock cycles. This additional time, area, and power was
the crux of the concern, and things looked to get worse in the future.
Silicon nanophotonics was of particular interest and seemed to be improving
rapidly. This led us to consider taking advantage of 3D packaging, where one
die in the 3D stack would be a photonic network layer. Our focus was on a
system that could be built about a decade out. Thus, we tried to predict how
the technologies and the system performance requirements would converge in
about 2018. Corona was the result this exercise; now, 15 years later, it's
interesting to look back at the effort.Comment: 2 pages. Proceedings of ISCA-50: 50 years of the International
Symposia on Computer Architecture (selected papers) June 17-21 Orlando,
Florid
Feasibility of recovered toner powder as an integral pigment in concrete
Colour is an important property in many construction materials with pigments, coatings and paints being used primarily for aesthetic, safety and restoration purposes. However, the use of integral pigments in materials like mortar and concrete can significantly increase material costs. Recovered toner powder (RTP) from printer and photocopier cartridges has the potential to be a low cost, sustainable alternative pigment. The aim of this research was to examine the feasibility of using cyan, yellow, magenta and black RTP to create a range of colour options for mortar and concrete, and thereafter assess the colour stability in outdoor, indoor, UV and wet/dry conditions using the colour change parameter (ΞE). The work showed that the RTP as a pigment could be blended to make a range of primary and secondary colours had good colour stability in all environments with minimal impact on selected properties of hardened concrete
Communications Biophysics
Contains research objectives and reports on two research projects.National Institutes of Health (Grant 2 PO1 GM-14941-01)Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E)National Aeronautics and Space Administration (Grant NsG-496)National Institutes of Health (Grant 2 RO1 NB-05462-04)National Institutes of Health (Grant 1 TO1 GM-01555-01
Internal representations, external representations and ergonomics: towards a theoretical integration
Visual masking: past accomplishments, present status, future developments
Visual masking, throughout its history, has been used as an investigative tool in
exploring the temporal dynamics of visual perception, beginning with retinal
processes and ending in cortical processes concerned with the conscious
registration of stimuli. However, visual masking also has been a phenomenon
deemed worthy of study in its own right. Most of the recent uses of visual
masking have focused on the study of central processes, particularly those
involved in feature, object and scene representations, in attentional control
mechanisms, and in phenomenal awareness. In recent years our understanding of
the phenomenon and cortical mechanisms of visual masking also has benefited from
several brain imaging techniques and from a number of sophisticated and
neurophysiologically plausible neural network models. Key issues and problems
are discussed with the aim of guiding future empirical and theoretical
research
Do I Have My Attention? Speed of Processing Advantages for the Self-Face Are Not Driven by Automatic Attention Capture
We respond more quickly to our own face than to other faces, but there is debate over whether this is connected to attention-grabbing properties of the self-face. In two experiments, we investigate whether the self-face selectively captures attention, and the attentional conditions under which this might occur. In both experiments, we examined whether different types of face (self, friend, stranger) provide differential levels of distraction when processing self, friend and stranger names. In Experiment 1, an image of a distractor face appeared centrally β inside the focus of attention β behind a target name, with the faces either upright or inverted. In Experiment 2, distractor faces appeared peripherally β outside the focus of attention β in the left or right visual field, or bilaterally. In both experiments, self-name recognition was faster than other name recognition, suggesting a self-referential processing advantage. The presence of the self-face did not cause more distraction in the naming task compared to other types of face, either when presented inside (Experiment 1) or outside (Experiment 2) the focus of attention. Distractor faces had different effects across the two experiments: when presented inside the focus of attention (Experiment 1), self and friend images facilitated self and friend naming, respectively. This was not true for stranger stimuli, suggesting that faces must be robustly represented to facilitate name recognition. When presented outside the focus of attention (Experiment 2), no facilitation occurred. Instead, we report an interesting distraction effect caused by friend faces when processing strangersβ names. We interpret this as a βsocial importanceβ effect, whereby we may be tuned to pick out and pay attention to familiar friend faces in a crowd. We conclude that any speed of processing advantages observed in the self-face processing literature are not driven by automatic attention capture
Visual perceptual load induces inattentional deafness
In this article, we establish a new phenomenon of βinattentional deafnessβ and highlight the level of load on visual attention as a critical determinant of this phenomenon. In three experiments, we modified an inattentional blindness paradigm to assess inattentional deafness. Participants made either a low- or high-load visual discrimination concerning a cross shape (respectively, a discrimination of line color or of line length with a subtle length difference). A brief pure tone was presented simultaneously with the visual task display on a final trial. Failures to notice the presence of this tone (i.e., inattentional deafness) reached a rate of 79% in the high-visual-load condition, significantly more than in the low-load condition. These findings establish the phenomenon of inattentional deafness under visual load, thereby extending the load theory of attention (e.g., Lavie, Journal of Experimental Psychology. Human Perception and Performance, 25, 596β616, 1995) to address the cross-modal effects of visual perceptual load
Genome Analyses of an Aggressive and Invasive Lineage of the Irish Potato Famine Pathogen
Pest and pathogen losses jeopardise global food security and ever since the 19th century Irish famine, potato late blight has exemplified this threat. The causal oomycete pathogen, Phytophthora infestans, undergoes major population shifts in agricultural systems via the successive emergence and migration of asexual lineages. The phenotypic and genotypic bases of these selective sweeps are largely unknown but management strategies need to adapt to reflect the changing pathogen population. Here, we used molecular markers to document the emergence of a lineage, termed 13_A2, in the European P. infestans population, and its rapid displacement of other lineages to exceed 75% of the pathogen population across Great Britain in less than three years. We show that isolates of the 13_A2 lineage are among the most aggressive on cultivated potatoes, outcompete other aggressive lineages in the field, and overcome previously effective forms of plant host resistance. Genome analyses of a 13_A2 isolate revealed extensive genetic and expression polymorphisms particularly in effector genes. Copy number variations, gene gains and losses, amino-acid replacements and changes in expression patterns of disease effector genes within the 13_A2 isolate likely contribute to enhanced virulence and aggressiveness to drive this population displacement. Importantly, 13_A2 isolates carry intact and in planta induced Avrblb1, Avrblb2 and Avrvnt1 effector genes that trigger resistance in potato lines carrying the corresponding R immune receptor genes Rpi-blb1, Rpi-blb2, and Rpi-vnt1.1. These findings point towards a strategy for deploying genetic resistance to mitigate the impact of the 13_A2 lineage and illustrate how pathogen population monitoring, combined with genome analysis, informs the management of devastating disease epidemic
The Discovery of Putative Urine Markers for the Specific Detection of Prostate Tumor by Integrative Mining of Public Genomic Profiles
Urine has emerged as an attractive biofluid for the noninvasive detection of prostate cancer (PCa). There is a strong imperative to discover candidate urinary markers for the clinical diagnosis and prognosis of PCa. The rising flood of various omics profiles presents immense opportunities for the identification of prospective biomarkers. Here we present a simple and efficient strategy to derive candidate urine markers for prostate tumor by mining cancer genomic profiles from public databases. Prostate, bladder and kidney are three major tissues from which cellular matters could be released into urine. To identify urinary markers specific for PCa, upregulated entities that might be shed in exosomes of bladder cancer and kidney cancer are first excluded. Through the ontology-based filtering and further assessment, a reduced list of 19 entities encoding urinary proteins was derived as putative PCa markers. Among them, we have found 10 entities closely associated with the process of tumor cell growth and development by pathway enrichment analysis. Further, using the 10 entities as seeds, we have constructed a protein-protein interaction (PPI) subnetwork and suggested a few urine markers as preferred prognostic markers to monitor the invasion and progression of PCa. Our approach is amenable to discover and prioritize potential markers present in a variety of body fluids for a spectrum of human diseases
Testosterone Is Associated with Erectile Dysfunction: A Cross-Sectional Study in Chinese Men
Testosterone is essential for the regulation of erectile physiology, but the relationship between low testosterone and erectile dysfunction (ED) has not been firmly established.To examine the association between serum total, free and bio-available testosterone and ED in a population-based sample.A consecutive series of 1776 men aged 20β77 participated in the routine physical examination from September 2009 to December 2009 in Guangxi, China. ED was assessed using the five-item International Index of Erectile Function (IIEF-5) questionnaire. Total testosterone (TT), sex hormone binding globulin (SHBG) and other biochemical profiles were measured. Free testosterone (FT) and bio-available testosterone (BT) were calculated based on Vermeulenβs formula. Data were collected with regard to smoking, alcoholic drinking, physical activity and metabolic syndrome.The prevalence of ED (IIEF-5<22) was 47.6%. Men with ED were significantly older, and more prone to smoke cigarettes (β₯20 cigarettes/day) or drink alcohol (β₯3 drinks/week), and more likely to have elevated blood pressure (Pβ=β0.036) or hyperglycemia (P<0.001) compared with those without ED. The significant increase in SHBG with age was parallel to its increase with increasing severity of ED (P<0.001). The obscure increase in TT across the ED status was detected without significance (Pβ=β0.418), but TT was positively associated with ED after adjustment for age [odds ratio (OR) β=β1.02, 95% CI (confidence internal): 1.00β1.04]. FT and BT were inversely associated with ED (ORβ=β0.14, 95%CI: 0.06β0.33; ORβ=β0.92 (95%CI: 0.89β0.96, respectively) in the univariate analysis, and this inverse association appeared to be independent of smoking status, alcoholic drinking, physical activity, hyper-triglyceridemia and hyperglycemia.FT and BT are inversely related to worsening ED, whereas the positive association between TT and ED is most likely due to the increase in SHBG
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