1,995 research outputs found
Accommodation and acuity in the human infant
No full textThe full-text of this book chapter is not available in ORA. Citation: Braddick, O. J. & Atkinson, J. (1979) Accommodation and acuity in the human infant. In: Freeman, R. D. (ed.) Developmental neurobiology of vision (NATO Advanced Study Institute Series, v. 27), New York: Plenum Press
What if Congress Doubled R&D Spending on the Physical Sciences?
No full textMany business, academic, and scientific groups have recommended that the Congress substantially increase R&D spending in the near future. President Bush's American Competitiveness Initiative calls for a doubling of spending over the next decade in selected agencies that deal with the physical sciences, including the National Science Foundation. We consider the rationale for government R&D spending in the context of globalization and as an investment in human capital and knowledge creation with gestation times far longer than Federal funding cycles. To assess the impact of a large increase in R&D spending on the science job market, we examine the impact of the 1998- 2003 doubling of the NIH budget on the bio-medical sciences. We find that the rapid increase in NIH spending and ensuing deceleration created substantial adjustment problems in the market for research and failed to address long-standing problems with scientific careers that are likely to deter many young people from choosing a scientific career. We argue that because research simultaneously produces knowledge and add to the human capital of researchers, which has greater value for young scientists because of their longer future career life span than to older scientists, there is reason for funding agencies to tilt their awards to younger researchers.Basic Science, R&D, labor markets for scientists, globalization
Depolarization and decreased surface expression of K+ channels contribute to NSAID-inhibition of intestinal restitution
No full textNon-steroidal anti-inflammatory drugs (NSAIDs) contribute to gastrointestinal ulcer formation by inhibiting epithelial cell migration and mucosal restitution; however, the drug-affected signaling pathways are poorly defined. We investigated whether NSAID inhibition of intestinal epithelial migration is associated with depletion of intracellular polyamines, depolarization of membrane potential (Em) and altered surface expression of K+ channels. Epithelial cell migration in response to the wounding of confluent IEC-6 and IEC-Cdx2 monolayers was reduced by indomethacin (100μM), phenylbutazone (100μM) and NS-398 (100μM) but not by SC-560 (1μM). NSAID-inhibition of intestinal cell migration was not associated with depletion of intracellular polyamines. Treatment of IEC-6 and IEC-Cdx2 cells with indomethacin, phenylbutazone and NS-398 induced significant depolarization of Em, whereas treatment with SC-560 had no effect on Em. The Em of IEC-Cdx2 cells was: −38.5±1.8mV under control conditions; −35.9±1.6mV after treatment with SC-560; −18.8±1.2mV after treatment with indomethacin; and −23.7±1.4mV after treatment with NS-398. Whereas SC-560 had no significant effects on the total cellular expression of Kv1.4 channel protein, indomethacin and NS-398 decreased not only the total cellular expression of Kv1.4, but also the cell surface expression of both Kv1.4 and Kv1.6 channel subunits in IEC-Cdx2. Both Kv1.4 and Kv1.6 channel proteins were immunoprecipitated by Kv1.4 antibody from IEC-Cdx2 lysates, indicating that these subunits co-assemble to form heteromeric Kv channels. These results suggest that NSAID inhibition of epithelial cell migration is independent of polyamine-depletion, and is associated with depolarization of Em and decreased surface expression of heteromeric Kv1 channels.ID: S0006295207001931; M3: Article; Accession Number: S0006295207001931; Author: L.C. Freeman (b); Author: D.F. Narvaez (a); Author: A. McCoy (a); Author: F.B. von Stein (c); Author: S. Young (b); Author: K. Silver (a); Author: S. Ganta (b); Author: D. Koch (b); Author: R. Hunter (b); Author: R.F. Gilmour (c); Author: J.D. Lillich (a, ⁎); Affiliation: Department of Clinical Sciences, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, United States; Keyword: Non-steroidal anti-inflammatory drugs; Keyword: Intestinal epithelial cells; Keyword: Membrane potential; Keyword: Potassium channels; Number of Pages: 12; Language: English;Source type: Electronic(1)http://search.ebscohost.com/login.aspx?direct=true&db=edselp&AN=S0006295207001931&site=eds-live&scope=sit
International R & D expenditures and external technology sourcing.
No full textThe paper examines the two-way relationship between external R&D activities and internal R&D expenditures on a cross-section of Flemish R&D active companies. The analysis extends the classical explanatory variables like size, diversification, ownership structure and technological opportunities to include the impact of various external sourcing strategies. R&D cooperation and to a lesser extent R&D contracted out are found to have a significant positive effect on internal R&D but only if the companies have absorptive capacity in the form of a full-time staffed R&D department. At the same time firms are found to be more likely engaged in R&D cooperation, the more they spend on internal R&D.International; Sourcing;
Binocular Cross-Orientation Suppression in the Cat's Striate Cortex
No full text Walker, Gary A., Izumi Ohzawa, and Ralph D. Freeman. Binocular cross-orientation suppression in the cat's striate cortex. J. Neurophysiol. 79: 227–239, 1998. When a cortical cell is activated by an optimal sinusoidal grating, its response can be attenuated by a superimposed second grating oriented orthogonally to the optimal stimulus. This effect is known as cross-orientation suppression (COS). In previous work, monocular characteristics have been explored and interocular tests have been conducted in an attempt to locate the origin of the suppression. In this study, we have recorded extracellularly from cortical cells to investigate the binocular characteristics of COS. Our hypothesis is that binocular disparity influences the strength of the effect. Our results do not support this supposition. We find that binocular COS is as strong as monocular COS, but disparity changes are of no consequence. We also conducted interocular tests in which the optimal grating and the orthogonal mask were seen by separate eyes. Although most interocular effects were weak, they were present in almost every cell and spanned a wide range of suppression strengths. We also tested the effect of asynchronous presentation of optimal and orthogonal gratings. These temporal offsets did not affect the strength of COS. We conclude that the suppressive mechanism underlying COS is primarily monocular and acts prior to the convergence of the two monocular streams. </jats:p
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Relative functions of feedforward, feedback, and horizontal connections in the central visual pathway
No full textVisual information processing in the central visual pathway is mediated by three main types of inter-cellular connections. These are feedforward, feedback, and horizontal connections. Most neurophysiological studies have been conducted in a perspective of feedforward connections assuming a hierarchical model. They revealed that convergent feedforward inputs determine size and structure of classical receptive fields (CRFs) of recipient cells in a higher level area. Non-feedforward connections are known to integrate visual information from outside the CRF and use this information to modulate the CRF activity. But relative roles of feedback and horizontal connections are not clear. My research interest is to figure out different functions for three major pathways in vision. In order to do this, I measure single unit activity in cat visual cortex while specific visual or magnetic stimulation is being applied to provide weighted activity from feedforward, feedback, and horizontal connections.In Chapter 1, we introduce visual stimuli specially designed to maximize relative differential involvements of three main types of neural connections. The approach is based on well-established anatomical and physiological features of neural projections in the central visual pathway. We show clear segregation of fast and slow components of surround modulation. Then, we present supporting evidences that they are primarily mediated by feedback and horizontal connections, respectively. Chapter 2 quantitatively describes transcranial magnetic stimulation (TMS) effects on neural activity. We focus specific stimulation parameters with limited visual stimuli and examine how TMS affects response selectivity (orientation, spatial frequency & contrast tuning) of visual neuron. Our findings suggest that TMS interrupts the existing balance between sub-cortical and intra-cortical inputs for a relatively extended time period. According to anatomical studies, proportions of sub-cortical and intra-cortical inputs to a single cell in the visual cortex are clearly different depending on cortical layers. In Chapter 3, we examine how intra-cortical inputs are differently contributing to direction selectivity of visual neurons by comparing various features of direction selectivity among multiple layers. Consistent with the classical view, our results show that linear estimation of direction selectivity (only sub-cortical inputs are considered) is quite accurate in input layers but substantially smaller in non-input layers, suggesting a considerable non-linear contribution of intra-cortical connections in these layers.Lastly, Chapter 4 describes issues related to trial-to-trial variability. Spiking response of a V1 single neuron to repeated presentations of the same visual stimulus is too variable to explain excellent behavioral performance in discrimination task. From the viewpoint of experimenter who controls the parameters of visual stimuli systematically, this trial-to-trial variability can be regarded as unpredictable noise which may reduce potential performance of neural computation. The source and advantage of trial-to-trial variability is not yet understood. Here, I introduce several response variability related issues that we already know and need to know
Greenhouse Vegetable Day, Thursday, April 30, 1964
No full textProgress report on mosaic resistance / Leonard J. Alexander -- Consumer's quality rating of greenhouse, vine ripe and tube tomatoes / Sabbah Al Haj -- Analysis of factors affecting week-to-week variations in retail margins for greenhouse tomatoes / Joseph D. Brown -- A comparison of two new hybrids and three new varieties with Ohio WR-7 / Walter N. Brown and E. K. Alban -- How much nitrogen does a tomato plant require? / Freeman S. Howlett and Dale W. Kretchman -- Important considerations concerning carbon dioxide enrichment of greenhouse atmospheres / D. W. Kretchman and F. S. Howlett -- Where are new fungicides? / Curt Leben -- Fifty years of greenhouse insect control / Ralph B. Neiswander -- Temperature and moisture and its effect on some greenhouse tomato diseases / R. E. Partyka -- Genetic control of insects / Roy W. Ring
Brengehman, Ralph Fred (Birth, 1907-05-12)
No full textAddress: 1210 Freeman Ave.2466/Pg 111/1907/M W/Dr. D. E. WeaverOriginal record filed in drawer labeled 'BREHM-BRIN'
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