2,201 research outputs found

    Systolic VLSI chip for implementing orthogonal transforms, A

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    Includes bibliographical references.This paper describes the design of a systolic VLSI chip for the implementation of signal processing algorithms that may be decomposed into a product of simple real rotations. These include orthogonal transformations. Applications of this chip include projections, discrete Fourier and cosine transforms, and geometrical transformations. Large transforms may be computed by "tiling" together many chips for increased throughput. A CMOS VLSI chip containing 138 000 transistors in a 5x3 array of rotators has been designed, fabricated, and tested. The chip has a 32-MHz clock and performs real rotations at a rate of 30 MHz. The systolic nature of the chip makes use of fully synchronous bit-serial interconnect and a very regular structure at the rotator and bit levels. A distributed arithmetic scheme is used to implement the matrix-vector multiplication of the rotation.This work was supported by Ball Aerospace, Boulder, CO, and by the Office of Naval Research, Electronics Branch, Arlington, VA, under Contract ONR 85-K-0693

    Research on plant disease and pest management is essential to sustainable agriculture

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    In the United States, a country with food in great abundance, it is difficult to realize that, were it not for the current level of plant disease and pest management, most human resources would be needed to obtain enough food and other plant and animal products merely to survive. Instead, there are surpluses, markets for many agricultural products are depressed, and funds available for research on plant disease and pest management-and for agricultural research generally-have plateaud or are declining. Why does the United States need more research on plant disease and pest management? Because the health and productivity of the crops and cropping systems upon which the people depend for their own consumption and for export cannot be sustained without continuing research and development. This continued investment is needed to manage ever threatening, changing, and rebounding diseases and pest populations. Moreover, disease and pest management of the future must be improved while simultaneously reducing our dependence on pesticides as one of many steps toward the goal of sustainable agriculture. The goal of plant disease and pest management is to ensure that crops are healthy enough to yield to their full genetic potential within the physical limits imposed by the uncontrolled variables of climate, weather, and soils. Management is defined as limiting damage from diseases or pests to a level at or below an acceptable economic or aesthetic threshold. This process does not require total elimination or eradication of the pest or disease problem. Reducing the use of pesticides is a desirable goal, but it depends on continued and increased investments in research on alternatives. For many chemical pesticides, the alternatives either are not yet developed or are less effective than chemicals. This research must be broadly based across the biological, physical, and social sciences. Moreover, the United States and the world depend not only on sustainable agriculture but also on sustainable growth in agriculture to meet a long-term increase in demand for quality and quantity of agricultural products expected from increases in both numbers and economic status of people (Rutan 1992). Furthermore. these increases must \u27be attained at the same time that available agricultural land is decreasing to satisfy other needs such as more land for recreation and urbanization; restoration of some wetlands, grasslands, and woodlands; and diversions of land from farming to other uses. Improved disease and pest management offers one of the few effective means by which the necessary increases in crop productivity can be accomplished while natural resources, including the remaining forests, are protected. These same principles apply to other uses of plants as well, including as ornamentals, for landscapes, and in parks and golf courses

    Research on plant disease and pest management is essential to sustainable agriculture

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    In the United States, a country with food in great abundance, it is difficult to realize that, were it not for the current level of plant disease and pest management, most human resources would be needed to obtain enough food and other plant and animal products merely to survive. Instead, there are surpluses, markets for many agricultural products are depressed, and funds available for research on plant disease and pest management-and for agricultural research generally-have plateaued or are declining. Why does the United States need more research on plant disease and pest management? Because the health and productivity of the crops and cropping systems upon which the people depend for their own consumption and for export cannot be sustained without continuing research and development. This continued investment is needed to manage ever threatening, changing, and rebounding diseases and pest populations. Moreover, disease and pest management of the future must be improved while simultaneously reducing our dependence on pesticides as one of many steps toward the goal of sustainable agriculture. The goal of plant disease and pest management is to ensure that crops are healthy enough to yield to their full genetic potential within the physical limits imposed by the uncontrolled variables of climate, weather, and soils. Management is defined as limiting damage from diseases or pests to a level at or below an acceptable economic or aesthetic threshold. This process does not require total elimination or eradication of the pest or disease problem

    Common evolutionary origin of acoustic communication in choanate vertebrates

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    Acoustic communication, broadly distributed along the vertebrate phylogeny, plays a fundamental role in parental care, mate attraction and various other behaviours. Despite its importance, comparatively less is known about the evolutionary roots of acoustic communication. Phylogenetic comparative analyses can provide insights into the deep time evolutionary origin of acoustic communication, but they are often plagued by missing data from key species. Here we present evidence for 53 species of four major clades (turtles, tuatara, caecilian and lungfish) in the form of vocal recordings and contextual behavioural information accompanying sound production. This and a broad literature-based dataset evidence acoustic abilities in several groups previously considered non-vocal. Critically, phylogenetic analyses encompassing 1800 species of choanate vertebrates reconstructs acoustic communication as a homologous trait, and suggests that it is at least as old as the last common ancestor of all choanate vertebrates, that lived approx. 407 million years before present

    Bifidobacterium animalis subsp lactis HN019 presents antimicrobial potential against periodontopathogens and modulates the immunological response of oral mucosa in periodontitis patients

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    Objective To evaluate the effects of Bifidobacterium animalis subsp. lactis HN019 (HN019) on clinical periodontal parameters (plaque accumulation and gingival bleeding), on immunocompetence of gingival tissues [expression of beta-defensin (BD)-3, toll-like receptor 4 (TLR4), cluster of differentiation(CD)-57 and CD-4], and on immunological properties of saliva (IgA levels) in non-surgical periodontal therapy in generalized chronic periodontitis (GCP) patients. Adhesion to buccal epithelial cells (BEC) and the antimicrobial properties of HN019 were also investigated. Materials and methods Thirty patients were recruited and monitored clinically at baseline (before scaling and root planing-SRP) and after 30 and 90 days. Patients were randomly assigned to Test (SRP +Probiotic, n = 15) or Control (SRP+Placebo, n = 15) group. Probiotic lozenges were used for 30 days. Gingival tissues and saliva were immunologically analyzed. The adhesion of HN019 with or without Porphyromonas gingivalis in BEC and its antimicrobial properties were investigated in in vitro assays. Data were statistically analyzed (p<0.05). Results Test group presented lower plaque index (30 days) and lower marginal gingival bleeding (90 days) when compared with Control group. Higher BD-3, TLR4 and CD-4 expressions were observed in gingival tissues in Test group than in Control group. HN019 reduced the adhesion of P. gingivalis to BEC and showed antimicrobial potential against periodontopathogens. Conclusion Immunological and antimicrobial properties of B. lactis HN019 make it a potential probiotic to be used in non-surgical periodontal therapy of patients with GCP.Fil: Invernici, Marcos M.. Universidade de Sao Paulo; BrasilFil: Furlaneto, Flåvia A. C.. Universidade de Sao Paulo; BrasilFil: Salvador, Sérgio L. Universidade de Sao Paulo; BrasilFil: Ouwehand, Arthur C.. Dupont, Nutrition and Health; FinlandiaFil: Salminen, Seppo. University of Turku. Functional Foods Forum; FinlandiaFil: Mantziari, Anastasia. University of Turku. Functional Foods Forum; FinlandiaFil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Ervolino, Edilson. São Paulo State University. Division of Histology, Department of Basic Sciences, Dental School of Araçatuba; BrasilFil: Santana, Sandro Isaías. Universidade de Sao Paulo; BrasilFil: Silva, Pedro Henrique Felix. Universidade de Sao Paulo; BrasilFil: Messora, Michel R.. Universidade de Sao Paulo; Brasi

    Endoventricular patch plasty for dyskinetic anteroapical left ventricular aneurysm increases systolic circumferential shortening in sheep

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    ObjectiveEndoventricular patch plasty (Dor procedure) has gained favor as a surgical treatment for heart failure associated with large anteroapical myocardial infarction. We tested the hypotheses that the Dor procedure increases systolic circumferential shortening and longitudinal shortening in noninfarcted left ventricular regions in sheep.MethodsIn 6 male Dorsett sheep, the left anterior descending coronary artery and its second diagonal branch were ligated 40% of the distance from the apex to the base. Sixteen weeks after myocardial infarction, a Dor procedure was performed with a Dacron patch that was 50% of the infarct neck dimension. Two weeks before and 2 and 6 weeks after the Dor procedure, animals underwent magnetic resonance imaging with tissue tagging in multiple short-axis and long-axis slices. Fully three-dimensional strain analyses were performed. All 6 end-systolic strain components were compared in regions 1 cm, 2 cm, 3 cm, and 4 cm below the valves, as well as in the anterior, posterior, and lateral left ventricular walls and the interventricular septum.ResultsCircumferential shortening increased from before the Dor procedure to 6 weeks after repair in nearly every left ventricular region (13/16). The greatest regional change in circumferential shortening was found in the equatorial region or 2 cm below the base and in the posterior wall (from 9.0% to 18.4%; P < .0001). Longitudinal shortening increased 2 weeks after the Dor procedure but then returned near baseline by 6 weeks after the Dor procedure.ConclusionThe Dor procedure significantly increases systolic circumferential shortening in nearly all noninfarcted left ventricular regions in sheep

    Bioelectrical understanding and engineering of cell biology

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    The last five decades of molecular and systems biology research have provided unprecedented insights into the molecular and genetic basis of many cellular processes. Despite these insights, however, it is arguable that there is still only limited predictive understanding of cell behaviours. In particular, the basis of heterogeneity in single-cell behaviour and the initiation of many different metabolic, transcriptional or mechanical responses to environmental stimuli remain largely unexplained. To go beyond the status quo, the understanding of cell behaviours emerging from molecular genetics must be complemented with physical and physiological ones, focusing on the intracellular and extracellular conditions within and around cells. Here, we argue that such a combination of genetics, physics and physiology can be grounded on a bioelectrical conceptualization of cells. We motivate the reasoning behind such a proposal and describe examples where a bioelectrical view has been shown to, or can, provide predictive biological understanding. In addition, we discuss how this view opens up novel ways to control cell behaviours by electrical and electrochemical means, setting the stage for the emergence of bioelectrical engineering

    Highly Variable Taxa-specific Coral Bleaching Responses to Thermal Stresses

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    Complex histories of chronic and acute sea surface temperature (SST) stresses are expected to trigger taxon- and location-specific responses that will ultimately lead to novel coral communities. The 2016 El Niño-Southern Oscillation provided an opportunity to examine large- scale and recent environmental histories on emerging patterns in 226 coral communities distrib- uted across 12 countries from East Africa to Fiji. Six main coral communities were identified that largely varied across a gradient of Acropora to massive Porites dominance. Bleaching intensity was taxon-specific and was associated with complex interactions among the 20 environmental variables that we examined. Coral community structure was better aligned with the historical temperature patterns between 1985 and 2015 than the 2016 extreme temperature event. Addi- tionally, bleaching responses observed during 2016 differed from historical reports during past warm years. Consequently, coral communities present in 2016 are likely to have been reorganized by both long-term community change and acclimation mechanisms. For example, less disturbed sites with cooler baseline temperatures, higher mean historical SST background variability, and infrequent extreme warm temperature stresses were associated with Acropora-dominated communities, while more disturbed sites with lower historical SST background variability and frequent acute warm stress were dominated by stress-resistant massive Porites corals. Overall, the combination of taxon-specific responses, community-level reorganization over time, geographic variation, and multiple environmental stressors suggest complex responses and a diversity of future coral communities that can help contextualize management priorities and activities

    Large Geographic Variability in the Resistance of Corals to Thermal Stress

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    Aim: Predictions for the future of coral reefs are largely based on thermal exposure and poorly account for potential geographic variation in biological sensitivity to ther- mal stress. Without accounting for complex sensitivity responses, simple climate ex- posure models and associated predictions may lead to poor estimates of future coral survival and lead to policies that fail to identify and implement the most appropri- ate interventions. To begin filling this gap, we evaluated a number of attributes of coral taxa and communities that are predicted to influence coral resistance to thermal stress over a large geographic range. Location: Western Indo-Pacific and Central Indo-Pacific Ocean Realms. Major taxa studied: Zooxanthellate Scleractinia – hard corals. Methods: We evaluated the geographic variability of coral resistance to thermal stress as the ratio of thermal exposure and sensitivity in 12 countries during the 2016 global-bleaching event. Thermal exposure was estimated by two metrics: (a) histori- cal excess summer heat (cumulative thermal anomaly, CTA), and (b) a multivariate index of sea-surface temperature (SST), light, and water flow (climate exposure, CE). Sensitivity was estimated for 226 sites using coordinated bleaching observations and underwater surveys of coral communities. We then evaluated coral resistance to ther- mal stress using 48 generalized linear mixed models (GLMMs) to compare the poten- tial influences of geography, historical SST variation, coral cover and coral richness. Results: Geographic faunal provinces and ecoregions were the strongest predic- tors of coral resistance to thermal stress, with sites in the Australian, Indonesian and Fiji-Caroline Islands coral provinces having higher resistance to thermal stress than Africa-India and Japan-Vietnam provinces. Ecoregions also showed strong gradients in resistance with highest resistance to thermal stress in the western Pacific and Coral Triangle and lower resistance in the surrounding ecoregions. A more detailed evaluation of Coral Triangle and non-Coral Triangle sites found higher resistance to thermal stress within the Coral Triangle, associated with c. 2.5 times more recent historical thermal anomalies and more centralized, warmer, and cool-water skew SST distributions, than in non-Coral Triangle sites. Our findings identify the importance of environmental history and geographic context in future predictions of bleaching, and identify some potential drivers of coral resistance to thermal stress. Main conclusions: Simple threshold models of heat stress and coral acclimation are commonly used to predict the future of coral reefs. Here and elsewhere we show that large-scale responses of coral communities to heat stress are geographically variable and associated with differential environmental stresses and histories
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