6,891 research outputs found
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Roberta Jaffe, Founding Director, Life Lab Science Program, Co-Founder of Community Agroecology Network
No full textRoberta (Robbie) Jaffe grew up in New York in the 1950s, and moved to Florida when she was sixteen. She attended the University of Florida and University of South Florida, and graduated with a degree in sociology. During and after college she was deeply involved in the United Farm Workers (UFW) movement as a field organizer and boycott organizer for the state of Florida. Jaffe first came to the Santa Cruz area with her then-husband, Jerry Kay, who was also active in the sustainable agriculture movement. They farmed ten acres near Elkhorn Slough, and in 1976, Jaffe helped start the first farmers’ market in Santa Cruz County, at Live Oak School.After that marriage ended, Jaffe studied horticulture at Cabrillo College with Richard Merrill, and took a position with a CETA (Comprehensive Employment and Training Act) program called Project Blossom. As part of that program, she co-founded a school garden at Green Acres School in Live Oak, a semi-rural area near Santa Cruz, California. This was the genesis of the Life Lab Science Program, which grew into a groundbreaking nonprofit organization that works with schools throughout the United States to develop school gardens and curriculum for teaching science and nutrition. Jaffe served as founding executive director of the program for many years.Jaffe earned a second master’s degree in education from UC Santa Cruz, with an emphasis in agroecology. She met and married Steve Gliessman (also the subject of an oral history in this series). In 2001, they co-founded the Community Agroecology Network (CAN). CAN defines its goals as, “to help a network of rural, primarily coffee-growing communities in Mexico and Central America develop self-sufficiency and sustainable growing practices, and direct market coffee to consumers in the United States.”Jaffe is the co-author of “From Differentiated Coffee Markets Towards Alternative Trade and Knowledge Networks,” in Confronting the Coffee Crisis: Sustaining Livelihoods and Ecosystems in Mexico and Central America, and many Life Lab publications, including The Growing Classroom.Ellen Farmer interviewed Robbie Jaffe on May 5, 2007, at Jaffe's house in Santa Cruz, California. Farmer’s MA thesis (in public policy) at California State University at Monterey Bay focused on the coffee crisis. As a graduate student, she worked with Jaffe at CAN, and brought her knowledge of the economics and politics of coffee growing in Latin America to the interview
Henri Temianka Correspondence; (jaffe)
No full textThis collection contains material pertaining to the life, career, and activities of Henri Temianka, violin virtuoso, conductor, music teacher, and author. Materials include correspondence, concert programs and flyers, music scores, photographs, and books.https://digitalcommons.chapman.edu/temianka_correspondence/3789/thumbnail.jp
A Search For Giant Planet Companions To T Tauri Stars
No full textWe present results from an ongoing multiwavelength radial velocity (RV) survey of the Taurus-Auriga star-forming region as part of our effort to identify pre-main-sequence giant planet hosts. These 1-3 Myr old T Tauri stars present significant challenges to traditional RV surveys. The presence of strong magnetic fields gives rise to large, cool star spots. These spots introduce significant RV jitter which can mimic the velocity modulation from a planet-mass companion. To distinguish between spot-induced and planet-induced RV modulation, we conduct observations at similar to 6700 angstrom and similar to 2.3 mu m and measure the wavelength dependence (if any) in the RV amplitude. CSHELL observations of the known exoplanet host Gl 86 demonstrate our ability to detect not only hot Jupiters in the near-infrared but also secular trends from more distant companions. Observations of nine very young stars reveal a typical reduction in RV amplitude at the longer wavelengths by a factor of similar to 2-3. While we cannot confirm the presence of planets in this sample, three targets show different periodicities in the two wavelength regions. This suggests different physical mechanisms underlying the optical and the K-band variability.SIM Young Planets Key ProjectNASA 05-SSO05-86, 07-SSO07-86, NCC 5-538NSFW.M. Keck FoundationAstronom
Market Value and Patent Citations: A First Look
No full textAs patent data become more available in machine-readable form, an increasing number of researchers have begun to use measures based on patents and their citations as indicators of technological output and information flow. This paper explores the economic meaning of these citation-based patent measures using the financial market valuation of the firms that own the patents. Using a new and comprehensive dataset containing over 4800 U. S. Manufacturing firms and their patenting activity for the past 30 years, we explore the contributions of R&D spending, patents, and citation-weighted patents to measures of Tobin's Q for the firms. We find that citation-weighted patent stocks are more highly correlated with market value than patent stocks themselves and that this fact is due mainly to the high valuation placed on firms that hold very highly cited patents.
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A Young-Planet Search in Visible and Infrared Light: Dn Tauri, V836 Tauri, and V827 Tauri
No full textIn searches for low-mass companions to late-type stars, correlation between radial velocity variations and line bisector slope changes indicates contamination by large starspots. Two young stars demonstrate that this test is not sufficient to rule out starspots as a cause of radial velocity variations. As part of our survey for substellar companions to T Tauri stars, we identified the similar to 2 Myr old planet host candidates DN Tau and V836 Tau. In both cases, visible-light radial velocity modulation appears periodic and is uncorrelated with line bisector span variations, suggesting close companions of several M(Jup) in these systems. However, high-resolution, infrared spectroscopy shows that starspots cause the radial velocity variations. We also report unambiguous results for V827 Tau, identified as a spotted star on the basis of both visible-light and infrared spectroscopy. Our results suggest that infrared follow-up observations are critical for determining the source of radial velocity modulation in young, spotted stars.NASA 05-SSO05-86Astronom
PRECISION RADIAL VELOCITIES WITH CSHELL
No full textRadial velocity (RV) identification of extrasolar planets has historically been dominated by optical surveys. Interest in expanding exoplanet searches to M dwarfs and young stars, however, has motivated a push to improve the precision of near-infrared RV techniques. We present our methodology for achieving 58 m s(-1) precision in the K band on the M0 dwarf GJ 281 using the CSHELL spectrograph at the 3 m NASA Infrared Telescope Facility. We also demonstrate our ability to recover the known 4 M-JUP exoplanet Gl 86 b and discuss the implications for success in detecting planets around 1-3 Myr old T Tauri stars.SIM Young Planets Key ProjectNASA 05-SSO05-86, 07-SSO07-86NSFAstronom
The approximation of Quantum Chromodynamics to the Ellis-Jaffe sum rule
No full textWe present the analytical calculation in perturbative Quantum Chromodynamics of the (alpha_s)^3 contribution to the Ellis-Jaffe sum rule for the structure function g1 of polarized deep inelastic lepton-nucleon scattering.We present the analytical calculation in perturbative Quantum Chromodynamics of the (alpha_s)~3 contribution to the Ellis-Jaffe sum rule for the structure function g1 of polarized deep inelastic lepton-nucleon scattering.We present the analytical calculation in perturbative Quantum Chromodynamics of the (alpha_s)~3 contribution to the Ellis-Jaffe sum rule for the structure function g1 of polarized deep inelastic lepton-nucleon scattering.We present the analytical calculation in perturbative Quantum Chromodynamics of the (alpha_s)~3 contribution to the Ellis-Jaffe sum rule for the structure function g1 of polarized deep inelastic lepton-nucleon scattering.We present the analytical calculation in perturbative Quantum Chromodynamics of the α S 3 contribution to the Ellis-Jaffe sum rule for the structure function g 1 of polarized deep inelastic lepton-nucleon scattering
The interstellar cosmic-ray electron spectrum from synchrotron radiation and direct measurements
No full textAims. We exploit synchrotron radiation to constrain the low-energy interstellar electron spectrum, using various radio surveys and connecting with electron data from Fermi-LAT and other experiments. Methods. The GALPROP programme for cosmic-ray propagation, gamma-ray and synchrotron radiation is used. Secondary electrons and positrons are included. Propagation models based on cosmic-ray and gamma-ray data are tested against synchrotron data from 22 MHz to 94 GHz. Results. The synchrotron data confirm the need for a low-energy break in the cosmic-ray electron injection spectrum. The interstellar spectrum below a few GeV has to be lower than standard models predict, and this suggests less solar modulation than usually assumed. Reacceleration models are more difficult to reconcile with the synchrotron constraints. We show that secondary leptons are important for the interpretation of synchrotron emission. We also consider a cosmic-ray propagation origin for the low-energy break. Conclusions. Exploiting the complementary information on cosmic rays and synchrotron gives unique and essential constraints on electrons, and has implications for gamma rays. This connection is especially relevant now in view of the ongoing Planck and Fermi missions
On a question of Huneke-Jaffe concerning seminormality
No full textWe answer a question of Huneke-Jaffe in the negative by constructing an example of a ring A containing a non-zerodivisor t such that A/tA is a seminormal integral domain but A is not seminormal. We also show that this example is universal among such examples
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