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Institution

University of California

EducationOakland, California, United States
About: University of California is a education organization based out in Oakland, California, United States. It is known for research contribution in the topics: Population & Layer (electronics). The organization has 55175 authors who have published 52933 publications receiving 1491169 citations. The organization is also known as: UC & University of California System.


Papers
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Journal ArticleDOI
TL;DR: Modern methods based on nucleic acid and protein analysis are described, which represent unprecedented tools to render agriculture more sustainable and safe, avoiding expensive use of pesticides in crop protection.
Abstract: Plant diseases are responsible for major economic losses in the agricultural industry worldwide. Monitoring plant health and detecting pathogen early are essential to reduce disease spread and facilitate effective management practices. DNA-based and serological methods now provide essential tools for accurate plant disease diagnosis, in addition to the traditional visual scouting for symptoms. Although DNA-based and serological methods have revolutionized plant disease detection, they are not very reliable at asymptomatic stage, especially in case of pathogen with systemic diffusion. They need at least 1–2 days for sample harvest, processing, and analysis. Here, we describe modern methods based on nucleic acid and protein analysis. Then, we review innovative approaches currently under development. Our main findings are the following: (1) novel sensors based on the analysis of host responses, e.g., differential mobility spectrometer and lateral flow devices, deliver instantaneous results and can effectively detect early infections directly in the field; (2) biosensors based on phage display and biophotonics can also detect instantaneously infections although they can be integrated with other systems; and (3) remote sensing techniques coupled with spectroscopy-based methods allow high spatialization of results, these techniques may be very useful as a rapid preliminary identification of primary infections. We explain how these tools will help plant disease management and complement serological and DNA-based methods. While serological and PCR-based methods are the most available and effective to confirm disease diagnosis, volatile and biophotonic sensors provide instantaneous results and may be used to identify infections at asymptomatic stages. Remote sensing technologies will be extremely helpful to greatly spatialize diagnostic results. These innovative techniques represent unprecedented tools to render agriculture more sustainable and safe, avoiding expensive use of pesticides in crop protection.

553 citations

Book ChapterDOI
01 Jan 2004
TL;DR: The evolution of industry depends on the selection mechanism, that is, the process of entry and exit of firms and the various factors influencing the entry/exit decisions as discussed by the authors, and three major factors are most important in the selection process, which emphasizes the firm's ability and competence to alter their market position and hence through strong increasing returns to scale, to alter the market structure significantly.
Abstract: The evolution of industry depends on the selection mechanism, that is, the process of entry and exit of firms and the various factors influencing the entry and exit decisions. Three major factors are most important in the selection process. One is the evolutionary perspective which emphasizes the firm’s ability and competence to alter their market position and hence through strong increasing returns to scale, to alter the market structure significantly. Following the Schumpeterian theory of technological innovations the main source of such increasing returns is the cumulative aspect of innovations, where “size begets size” causes industrial dynamics to be characterized by nonlinear and path dependent processes, where random events like a new technical process may have lasting and irreversible effects on the dynamic evolution of the selection process. Secondly, firms differ significantly in their commitment and ability to innovate. Thus innovations in products and processes are largely endogenous to the firm through R&D investment and learning-by-doing. Thus vigorous innovation has been found to generate more competitive market structures, while innovations requiring large investment generally involve more concentration through large size firms. Also due to the cumulative nature of technological innovations firms that discover new technologies are able to maintain their lead even after the particular technology is obsolete.

553 citations

Book ChapterDOI
01 Jan 1989
TL;DR: The concept of soil availability may represent the rate at which N is converted from unavailable to available forms within the rooting zone (Scarsbrook, 1965) or it may refer to the extent to which plant production is constrained by a limited supply of available N.
Abstract: The availability of nitrogen (N) limits production in many forest ecosystems, and many methods are available for estimating N availability (Keeney, 1980; Binkley 1986; Mahendrappa et al., 1986; Binkley and Vitousek, 1989). The concept of soil availability may represent the rate at which N is converted from unavailable to available forms within the rooting zone (Scarsbrook, 1965). Alternatively, it may refer to the extent to which plant production is constrained by a limited supply of available N. These two aspects of N availability were termed N supply rate and N limitation by Chapin et al. (1986). In agroecosystems, N supply rate and N limitation are often closely linked. In forest ecosystems, differences in species composition, stand age, and soil moisture may uncouple low N supply from N limitation (Chapin et al., 1986). In addition, the nonuniform rooting distribution of trees and the presence of forest floors add spatial complexities to forest N cycles that make it more difficult to estimate N availability in forests than in agroecosystems.

551 citations

Book ChapterDOI
01 Jan 2002
TL;DR: In this paper, genetic engineering of crop plants for enhanced salt tolerance will be a very important approach to reach this goal, genetic lines of some crop species have been generated which can grow and develop at fairly high salinity levels in controlled environments.
Abstract: Agricultural losses caused by salinity are difficult to assess but estimated to be substantial and expected to increase with time. Secondary salinization of agricultural lands is particularly widespread in arid and semiarid environments where crop production requires irrigation chemes. At least 20% of all irrigated lands are salt-affected, with some estimates being as high as 50%. Whereas the world’s population continues to rise, the total land area under irrigation appears to have leveled off. The need for increased food production therefore needs to be met by increases in yield per land area. To reach this goal, genetic engineering of crop plants for enhanced salt tolerance will be a very important approach. In dry regions where fresh water becomes a scarce commodity, irrigation of moderately salt tolerant crops with brackish water is feasible. Transgenic lines of some crop species have been generated which can grow and develop at fairly high salinity levels in controlled environments. These transgenics must be tested vigorously for yield potential under field conditions.

550 citations

Journal ArticleDOI
TL;DR: In this paper, the role of extended objects in Liouville theory, including surface operators and line operators, has been investigated under the assumption of a duality between four dimensional N = 2 GAs.
Abstract: Recently, a duality between Liouville theory and four dimensional N = 2 gauge theory has been uncovered by some of the authors. We consider the role of extended objects in gauge theory, surface operators and line operators, under this correspondence. We map such objects to specific operators in Liouville theory. We employ this connection to compute the expectation value of general supersymmetric ’t Hooft-Wilson line operators in a variety of N = 2 gauge theories.

550 citations


Authors

Showing all 55232 results

NameH-indexPapersCitations
Meir J. Stampfer2771414283776
George M. Whitesides2401739269833
Michael Karin236704226485
Fred H. Gage216967185732
Rob Knight2011061253207
Martin White1962038232387
Simon D. M. White189795231645
Scott M. Grundy187841231821
Peidong Yang183562144351
Patrick O. Brown183755200985
Michael G. Rosenfeld178504107707
George M. Church172900120514
David Haussler172488224960
Yang Yang1712644153049
Alan J. Heeger171913147492
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202322
2022105
2021775
20201,069
20191,225
20181,684