37,354 research outputs found
Distribution of enzymes cleaving pyridine nucleotides in animal tissues
A number of enzymes capable of splitting the pyridine nucleotides have been found in animal tissues. A portion of the DPNase (1) that hydrolyzes the nicotinamide ribose bond of DPN and TPN was reported in the microsomes of rat liver (1). The DPN pyrophosphorylase, first described by Kornberg (2), has been found by Hogeboom and Schneider to be largely localized in the nucleus (3). In previous investigations (4) an enzyme from pigeon liver which splits DPNH and not DPN at the pyrophosphate linkage was described. The present communication deals with the intracellular distribution of enzymes from various species that attack the pyridine coenzymes at the pyrophosphate linkage. The distribution and properties of DPNases from different species and tissues will also be presented
Worker Discretion and Misallocation of Talent within Firms
We develop a theory of worker discretion over task choice within a firm. Increasing the workers’ discretion has a trade-off between the gains from workers using private information about their abilities, and the costs from adverse selection within the firm due to workers herding into prestigious tasks. The theory leads to the result that, in line with the Peter Principle, misallocation of talent within firms takes the form of too many workers undertaking tasks with a high return to ability. Moreover we find that the degree of misallocation of talent is decreasing in the degree of discretion given to workers.Authority, Bureaucracies, Career Concerns, Discretion, Organizational Design, Misallocation, Peter Principle, Principal-Agent Theory, Sun Hydraulics, Wage Dynamics
A Theory of Capital Structure with Strategic Defaults and Priority Violations
Why do firms delegate job design decisions to workers and what are the implications of such delegation? We develop a private-information based theory of delegation where delegation provides a more efficient allocation of talent inside the firm, but at the cost that low ability workers must be compensated to self-sort. Career concerns limit the effectiveness of delegation: when returns to ability or market observability of job content are high, the compensation needed to get low-ability workers to self-sort is high, and firms limit delegation to avoid cream-skimming of the high-ability workers. We investigate implications for how misallocation of talent within firms may occur, the optimal design of incentive contracts, and which decisions are more likely to be delegated to subordinates.Cash Diversion, Costly State Verification, Outside Equity, Financial Contracts.
Bounds on Expected Black Hole Spins in Inspiraling Binaries
As a first step towards understanding the angular momentum evolution history
of black holes in merging black-hole/neutron-star binaries, we perform
population synthesis calculations to track the distribution of accretion
histories of compact objects in such binaries. We find that there are three
distinct processes which can possibly contribute to the black-hole spin
magnitude: a birth spin for the black hole, imparted at either (i) the collapse
of a massive progenitor star to a black hole or (ii) the accretion-induced
collapse of a neutron star to a black hole; and (iii) an accretion spin-up when
the already formed black hole [via (i) or (ii)] goes through an accretion
episode (through an accretion disk or a common-envelope phase). Our results
show that, with regard to accretion-induced spinup in merging BH-NS binaries
[method (iii) above], only
{\em accretion episodes associated with common-envelope phases and
hypercritical accretion rates} occur in the formation history of merging black
hole/neutron star binaries. Lacking unambiguous experimental information about
BH birth spins [i.e., regarding the results of processes (i) and (ii)], we
choose two fiducial values for the BH birth angular momentum parameter a=J/M^2,
consistent with observations of (i) NS birth spins (a roughly 0) and (ii) X-ray
binaries (a=0.5). Using these two fiducial values and a conservative upper
bound on the specific angular momentum of accreted matter, we discuss the
expected range of black hole spins in the binaries of interest. We conclude
with comments on the significance of these results for ground-based
gravitational-wave searches of inspiral signals from black hole binaries.Comment: Submitted to ApJ. (v1) Uses emulateapj.cls. 5 figures. (v2):
corrected reference list and uses smaller figures (v3): Includes changes in
response to referee comments, including new discussion of XRBs. Figures
merged, so only 3 figures (v4) Minor typo correction, plus updated abstract
posted onlin
Novel Approach to Super Yang-Mills Theory on Lattice - Exact fermionic symmetry and "Ichimatsu" pattern -
We present a lattice theory with an exact fermionic symmetry, which mixes the
link and the fermionic variables. The staggered fermionic variables may be
reconstructed into a Majorana fermion in the continuum limit. The gauge action
has a novel structure. Though it is the ordinary plaquette action, two
different couplings are assigned in the ``Ichimatsu pattern'' or the checkered
pattern. In the naive continuum limit, the fermionic symmetry survives as a
continuum (or an ) symmetry. The transformation of the fermion is
proportional to the field strength multiplied by the difference of the two
gauge couplings in this limit. This work is an extension of our recently
proposed cell model toward the realization of supersymmetric Yang-Mills theory
on lattice.Comment: 26 pages, 4 figure
SODA WARS: THE EFFECT OF A SODA TAX ELECTION ON UNIVERSITY BEVERAGE SALES
We examine how soda sales changed due to the campaign attention and election outcome of a local excise tax on sugar-sweetened beverages. Using panel data of beverage sales from university retailers in Berkeley, California, we estimate that soda purchases relative to control beverages significantly dropped immediately after the election, months before the tax was implemented in the city of Berkeley or on campus. Supplemental scanner data from off-campus retailers reveal this result is not unique to the university setting. Our findings suggest soda tax media coverage and election outcomes can have larger effects on purchasing behavior than the tax itself. (JEL D12, H20, C23, I38, Q18)
Kinetic Voronoi Diagrams and Delaunay Triangulations under Polygonal Distance Functions
Let be a set of points and a convex -gon in .
We analyze in detail the topological (or discrete) changes in the structure of
the Voronoi diagram and the Delaunay triangulation of , under the convex
distance function defined by , as the points of move along prespecified
continuous trajectories. Assuming that each point of moves along an
algebraic trajectory of bounded degree, we establish an upper bound of
on the number of topological changes experienced by the
diagrams throughout the motion; here is the maximum length of an
-Davenport-Schinzel sequence, and is a constant depending on the
algebraic degree of the motion of the points. Finally, we describe an algorithm
for efficiently maintaining the above structures, using the kinetic data
structure (KDS) framework
- …