Interview with Patrick Leahy by Brien Williams

Biographical NotePatrick Joseph Leahy was born in Montpelier, Vermont, on March 31, 1940. He was graduated from Saint Michael’s College in 1961 and Georgetown Law in 1964. Beginning in 1966, he was elected to four consecutive terms as Vermont state’s attorney in Chittenden County. At the age of 34, he became the youngest U.S. senator ever elected by Vermont, and he is the only elected Democrat from Vermont ever to serve in the U.S. Senate. During the 1980s, he was vice chairman of the Senate Select Committee on Intelligence and chairman of the Agriculture, Nutrition and Forestry Committee. At the time of this interview, he was chairman of the Senate Judiciary Committee and a senior member of the Agriculture and Appropriations Committees, ranking second in seniority in the Senate. SummaryInterview includes discussion of: Mitchell’s arrival in the Senate and his perceived qualities, especially his negotiating skills; Mitchell’s quick rise to Senate leadership; Mitchell’s decision to retire from the Senate; Mitchell’s potential as a Supreme Court justice

Advice and Consent: Ensuring Judicial Freedom

Throughout this nation\u27s history, Americans have turned to the Supreme Court to protect their rights against excesses of the legislative and executive branches. To protect this crucial role of the Court, the Framers realized that neither the executive nor the legislature should have the power to cast the Court in its own image. To prevent this usurpation of one branch by another, the Framers wisely required the President to obtain the advice and consent of the Senate in making appointments to the Supreme Court

The Linear-Size Evolution of Classical Double Radio Sources

Recent investigations of how the median size of extragalactic radio sources change with redshift have produced inconsistent results. Eales compared the radio and optical properties of a bright 3C and faint 6C sample and concluded that $D\propto(1+z)^{-1.1\pm0.5}$ ($\Omega_0 = 0$), with $D$ being the median size of the radio sources at a given epoch and z the redshift. Oort, Katgert, and Windhorst, on the other hand, from a comparison of the properties of a number of radio samples, found much stronger evolution, with $D\propto(1+z)^{-3.3 \pm0.5}$. In this paper we attempt to resolve the difference. We have repeated the analysis of Eales using the virtually complete redshift information that now exists for the 6C sample. Confining our analysis to FR2 sources, which we argue is the best-understood class of radio sources and the least likely to be affected by selection effects, we find $D\propto(1+z)^{-1.2\pm0.5}$ ($\Omega_0 = 0$) and $D\propto(1+z)^{-1.7\pm0.4}$ ($\Omega_0 = 1$). Our complete redshift information allows us to gain insight into our result by plotting a radio luminosity-size (P-D) diagram for the 6C sample. The most obvious difference between the 3C and 6C P-D diagrams is the clump of sources in the 6C diagram at $D\sim 100 kpc, P_{151}\sim 5x10^{27} WHz^{-1}sr^{-1}$. These clump sources have similar sizes to the emission-line regions found around high-redshift radio galaxies, suggesting that the presence of dense line-emitting gas around high-redshift radio galaxies is responsible for the size evolution. We show that this explanation can quantitatively explain the observed size evolution, as long as there is either little X-ray emitting gas around these objects or, if there is, it is distributed in a similar way to the emission-line gas: highly anisotropic and inhomogeneous.Comment: compressed and uuencoded postscript file. 33 pages including 5 figures (441951 bytes). Accepted for publication in September Ap

The FRET Signatures of Noninteracting Proteins in Membranes: Simulations and Experiments

AbstractFörster resonance energy transfer (FRET) experiments are often used to study interactions between integral membrane proteins in cellular membranes. However, in addition to the FRET of sequence-specific interactions, these experiments invariably record a contribution due to proximity FRET, which occurs when a donor and an acceptor approach each other by chance within distances of ∼100 Å. This effect does not reflect specific interactions in the membrane and is frequently unappreciated, despite the fact that its magnitude can be significant. Here we develop a computational description of proximity FRET, simulating the cases of proximity FRET when fluorescent proteins are used to tag monomeric, dimeric, trimeric, and tetrameric membrane proteins, as well as membrane proteins existing in monomer-dimer equilibria. We also perform rigorous experimental measurements of this effect, by identifying membrane receptors that do not associate in mammalian membranes. We measure the FRET efficiencies between yellow fluorescent protein and mCherry-tagged versions of these receptors in plasma-membrane-derived vesicles as a function of receptor concentration. Finally, we demonstrate that the experimental measurements are well described by our predictions. The work presented here brings additional rigor to FRET-based studies of membrane protein interactions, and should have broad utility in membrane biophysics research

Using Global Positioning System Technology to Manage Human-Black Bear Incidents at Yosemite National Park

Managing human–bear (Ursus spp.) incidents is a top management priority in national parks inhabited by bears. Yosemite National Park (Yosemite), located in the Sierra Nevada in California, USA, receives up to 5 million visitors annually. It is also home to 300–500 black bears (U. americanus). Yosemite has an extensive history of black bear research, educational programs, and innovative solutions for reducing human–bear incidents. Despite this, human–bear incidents peaked in 1998 at 1,584. The resulting political fallout led to Yosemite receiving funds to expand its bear management program, including increasing its staffing and garbage pick-up, and improving the park’s bear-resistant infrastructure. In 2011, Yosemite reached a milestone when it recorded only 114 human–bear incidents—a 93% decrease from the 1998 high. To sustain this lower level of incidents while facing shrinking budgets and increasing visitation, bear managers turned to more modern technology. From 2014–2018, we evaluated the effectiveness of using global positioning system (GPS) collars to manage bears more proactively, increase staff and public engagement with bears, and gain insight into the bears’ spatial and temporal movements. The GPS collars were effective in achieving these goals, while also improving both our time management and our communication with park management. By the end of November 2018, Yosemite had recorded only 22 human–bear incidents—a 99% decrease from the 1998 high. The GPS collars are now an integral part of the Yosemite bear management program. We provide recommendations on how GPS technology may help other parks reduce human–bear incidents

The C-Band All-Sky Survey: Instrument design, status, and first-look data

The C-Band All-Sky Survey (C-BASS) aims to produce sensitive, all-sky maps of diffuse Galactic emission at 5 GHz in total intensity and linear polarization. These maps will be used (with other surveys) to separate the several astrophysical components contributing to microwave emission, and in particular will allow an accurate map of synchrotron emission to be produced for the subtraction of foregrounds from measurements of the polarized Cosmic Microwave Background. We describe the design of the analog instrument, the optics of our 6.1 m dish at the Owens Valley Radio Observatory, the status of observations, and first-look data.Comment: 10 pages, 11 figures, published in Proceedings of SPIE MIllimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy V (2010), Vol. 7741, 77411I-1 - 77411I-1

The Optical-Near-IR Spectrum of the M87 Jet From HST Observations

We present 1998 HST observations of M87 which yield the first single-epoch optical and radio-optical spectral index images of the jet at $0.15''$ resolution. We find $\approx 0.67$, comparable to previous measurements, and $\approx 0.9$ ($F_\nu \propto \nu^{-\alpha}$), slightly flatter than previous workers. Reasons for this discrepancy are discussed. These observations reveal a large variety of spectral slopes. Bright knots exhibit flatter spectra than interknot regions. The flattest spectra ($\alpha_o \sim 0.5-0.6$; comparable to or flatter than $\alpha_{ro}$) are found in two inner jet knots (D-East and HST-1) which contain the fastest superluminal components. In knots A, B and C, $\alpha_o$ and $\alpha_{ro}$ are essentially anti-correlated. Near the flux maxima of knots HST-1 and F, changes in $\alpha_{ro}$ lag changes in $\alpha_o$, but in knots D and E, the opposite relationship is observed. This is further evidence that radio and optical emissions in the M87 jet come from substantially different physical regions. The delays observed in the inner jet are consistent with localized particle acceleration, with $t_{acc} << t_{cool}$ for optically emitting electrons in knots HST-1 and F, and $t_{acc} \sim t_{cool}$ for optically emitting electrons in knots D and E. Synchrotron models yield \nu_B \gsim 10^{16} Hz for knots D, A and B, and somewhat lower values, $\nu_B \sim 10^{15}- 10^{16}$ Hz, in other regions. If X-ray emissions from knots A, B and D are co-spatial with optical and radio emission, we can strongly rule out the ``continuous injection'' model. Because of the short lifetimes of X-ray synchrotron emitting particles, the X-ray emission likely fills volumes much smaller than the optical emission regions.Comment: Text 17 pages, 3 Tables, 11 figures, accepted by Ap

A conserved strategy for inducing appendage regeneration

Can limb regeneration be induced? Few have pursued this question, and an evolutionarily conserved strategy has yet to emerge. This study reports a strategy for inducing regenerative response in appendages, which works across three species that span the animal phylogeny. In Cnidaria, the frequency of appendage regeneration in the moon jellyfish Aurelia was increased by feeding with the amino acid L-leucine and the growth hormone insulin. In insects, the same strategy induced tibia regeneration in adult Drosophila. Finally, in mammals, L-leucine and sucrose administration induced digit regeneration in adult mice, including dramatically from mid- phalangeal amputation. The conserved effect of L-leucine and insulin/sugar suggests a key role for energetic parameters in regeneration induction. The simplicity by which nutrient supplementation can induce appendage regeneration provides a testable hypothesis across animals