259 research outputs found
Bonds - Income Bonds - Rights of Bondholders and Deductibility of Interest for Federal Income Tax Purposes
An income bond is an obligation of a corporation on which interest is payable only out of earnings, as distinguished from the ordinary corporate bond on which interest is a fixed charge regardless of earnings. Long regarded as a hybrid security which is to be issued only as a last resort, income bonds have grown surprisingly in popularity over the past two decades. It is the purpose of this comment to consider the historical background of income bonds, to make a comparative analysis of the bond indentures as they affect investors\u27 rights, and to consider the deductibility of income bond interest in determining taxable income for federal income tax purposes. A study of the twenty-three companies whose income bonds are currently listed on the New York Stock Exchange is the focal point for this comment, but the particular problems incident to unlisted bonds of small and closely-held corporations will also be considered
The DP Color Function of Clique-Gluings of Graphs
DP-coloring (also called correspondence coloring) is a generalization of list
coloring that has been widely studied in recent years after its introduction by
Dvo\v{r}\'{a}k and Postle in 2015. As the analogue of the chromatic polynomial
of a graph , , the DP color function of , denoted ,
counts the minimum number of DP-colorings over all possible -fold covers.
Formulas for chromatic polynomials of clique-gluings of graphs are well-known,
but the effect of such gluings on the DP color function is not well understood.
In this paper we study the DP color function of -gluings of graphs.
Recently, Becker et. al. asked whether whenever , where the expression on the right is the DP-coloring analogue of the
corresponding chromatic polynomial formula for a -gluing of . Becker et. al. showed this inequality holds when . In this paper we
show this inequality holds for edge-gluings (). On the other hand, we show
it does not hold for triangle-gluings (), which also answers a question of
Dong and Yang (2021). Finally, we show a relaxed version, based on a class of
-fold covers that we conjecture would yield the fewest DP-colorings for a
given graph, of the inequality holds when .Comment: 20 pages, 1 figure. arXiv admin note: substantial text overlap with
arXiv:2104.1226
Physical conditions regulate the fungal to bacterial ratios of a tropical suspended soil
As a source of ‘suspended soils’, epiphytes contribute large amounts of organic matter to the canopy of tropical rain forests. Microbes associated with epiphytes are responsible for much of the nutrient cycling taking place in rain forest canopies. However, soils suspended far above the ground in living organisms differ from soil on the forest floor, and traditional predictors of soil microbial community composition and functioning (nutrient availability and the activity of soil organisms) are likely to be less important. We conducted an experiment in the rain forest biome at the Eden Project in Cornwall to explore how biotic and abiotic conditions determine microbial community composition and functioning in a suspended soil. To simulate their natural epiphytic lifestyle, 20 bird’s nest ferns (Asplenium nidus) were placed on a custom-built canopy platform suspended 8m above the ground. Ammonium nitrate and earthworm treatments were applied to ferns in a factorial design. Extracellular enzyme activity and Phospholipid Fatty Acid (PLFA) profiles were determined at zero, three and six months. We observed no significant differences in either enzyme activity or PLFA profiles between any of the treatments. Instead, we observed decreases in β-glucosidase and N-acetyl-glucosaminidase activity, and an increase in phenol oxidase activity across all treatments and controls. An increase in the relative abundance of fungi during the experiment meant that the microbial communities in the Eden Project ferns after six months were comparable with 20 ferns sampled from pristine tropical rain forest in Borneo
Soil methane sink capacity response to a long-term wildfire chronosequence in Northern Sweden
Boreal forests occupy nearly one fifth of the terrestrial land surface and are recognised as globally important regulators of carbon (C) cycling and greenhouse gas emissions. Carbon sequestration processes in these forests include assimilation of CO2 into biomass and subsequently into soil organic matter, and soil microbial oxidation of methane (CH4). In this study we explored how ecosystem retrogression, which drives vegetation change, regulates the important process of soil CH4 oxidation in boreal forests. We measured soil CH4 oxidation processes on a group of 30 forested islands in northern Sweden differing greatly in fire history, and collectively representing a retrogressive chronosequence, spanning 5000 years. Across these islands the build-up of soil organic matter was observed to increase with time since fire disturbance, with a significant correlation between greater humus depth and increased net soil CH4 oxidation rates. We suggest that this increase in net CH4 oxidation rates, in the absence of disturbance, results as deeper humus stores accumulate and provide niches for methanotrophs to thrive. By using this gradient we have discovered important regulatory controls on the stability of soil CH4 oxidation processes that could not have not been explored through shorter-term experiments. Our findings indicate that in the absence of human interventions such as fire suppression, and with increased wildfire frequency, the globally important boreal CH4 sink could be diminished
On renormalization group flows and the a-theorem in 6d
We study the extension of the approach to the a-theorem of Komargodski and
Schwimmer to quantum field theories in d=6 spacetime dimensions. The dilaton
effective action is obtained up to 6th order in derivatives. The anomaly flow
a_UV - a_IR is the coefficient of the 6-derivative Euler anomaly term in this
action. It then appears at order p^6 in the low energy limit of n-point
scattering amplitudes of the dilaton for n > 3. The detailed structure with the
correct anomaly coefficient is confirmed by direct calculation in two examples:
(i) the case of explicitly broken conformal symmetry is illustrated by the free
massive scalar field, and (ii) the case of spontaneously broken conformal
symmetry is demonstrated by the (2,0) theory on the Coulomb branch. In the
latter example, the dilaton is a dynamical field so 4-derivative terms in the
action also affect n-point amplitudes at order p^6. The calculation in the
(2,0) theory is done by analyzing an M5-brane probe in AdS_7 x S^4.
Given the confirmation in two distinct models, we attempt to use dispersion
relations to prove that the anomaly flow is positive in general. Unfortunately
the 4-point matrix element of the Euler anomaly is proportional to stu and
vanishes for forward scattering. Thus the optical theorem cannot be applied to
show positivity. Instead the anomaly flow is given by a dispersion sum rule in
which the integrand does not have definite sign. It may be possible to base a
proof of the a-theorem on the analyticity and unitarity properties of the
6-point function, but our preliminary study reveals some difficulties.Comment: 41 pages, 5 figure
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Attenuation of Replication-Competent Adenovirus Serotype 26 Vaccines by Vectorization
Replication-competent adenovirus (rcAd)-based vaccine vectors may theoretically provide immunological advantages over replication-incompetent Ad vectors, but they also raise additional potential clinical and regulatory issues. We produced replication-competent Ad serotype 26 (rcAd26) vectors by adding the E1 region back into a replication-incompetent Ad26 vector backbone with the E3 or E3/E4 regions deleted. We assessed the effect of vectorization on the replicative capacity of the rcAd26 vaccines. Attenuation occurred in a stepwise fashion, with E3 deletion, E4 deletion, and human immunodeficiency virus type 1 (HIV-1) envelope (Env) gene insertion all contributing to reduced replicative capacity compared to that with the wild-type Ad26 vector. The rcAd26 vector with E3 and E4 deleted and containing the Env transgene exhibited 2.7- to 4.4-log-lower replicative capacity than that of the wild-type Ad26 in vitro. This rcAd26 vector is currently being evaluated in a phase 1 clinical trial. Attenuation as a result of vectorization and transgene insertion has implications for the clinical development of replication-competent vaccine vectors
AP-1 and KIF13A coordinate endosomal sorting and positioning during melanosome biogenesis
The clathrin adaptor protein AP-1 and the motor KIF13A work together to deliver cargo into maturing melanosomes
Safety, pharmacokinetics and antiviral activity of PGT121, a broadly neutralizing monoclonal antibody against HIV-1: a randomized, placebo-controlled, phase 1 clinical trial
Human immunodeficiency virus (HIV)-1-specific broadly neutralizing monoclonal antibodies are currently under development to treat and prevent HIV-1 infection. We performed a single-center, randomized, double-blind, dose-escalation, placebo-controlled trial of a single administration of the HIV-1 V3-glycan-specific antibody PGT121 at 3, 10 and 30 mg k
A Candidate Dual AGN at z=1.175
The X-ray source CXOXBJ142607.6+353351 (CXOJ1426+35), which was identified in
a 172 ks Chandra image in the Bootes field, shows double-peaked rest-frame
optical/UV emission lines, separated by 0.69" (5.5 kpc) in the spatial
dimension and by 690 km s^-1 in the velocity dimension. The high excitation
lines and emission line ratios indicate both systems are ionized by an AGN
continuum, and the double-peaked profile resembles that of candidate dual AGN.
At a redshift of z=1.175, this source is the highest redshift candidate dual
AGN yet identified. However, many sources have similar emission line profiles
for which other interpretations are favored. We have analyzed the substantial
archival data available in this field, as well as acquired near-infrared (NIR)
adaptive optics (AO) imaging and NIR slit spectroscopy. The X-ray spectrum is
hard, implying a column density of several 10^23 cm^-2. Though heavily
obscured, the source is also one of the brightest in the field, with an
absorption-corrected 2-10 keV luminosity of ~10^45 erg s^-1. Outflows driven by
an accretion disk may produce the double-peaked lines if the central engine
accretes near the Eddington limit. However, we may be seeing the narrow line
regions of two AGN following a galactic merger. While the AO image reveals only
a single source, a second AGN would easily be obscured by the significant
extinction inferred from the X-ray data. Understanding the physical processes
producing the complex emission line profiles seen in CXOJ1426+35 and related
sources is important for interpreting the growing population of dual AGN
candidates.Comment: 18 pages and 9 figures. Accepted for publication in The Astrophysical
Journa
Felony Murder and Capital Punishment: an Examination of the Deterrence Question
A proper test of the deterrent effect of the death penalty must consider capital homicides. However, the criterion variable in most investigations has been total homicides—most of which bear no legal or theoretical relationship to capital punishment. To address this fundamental data problem, this investigation used Federal Bureau of Investigation data for 1976–1987 to examine the relationship between capital punishment and felony murder, the most common type of capital homicide. We conducted time series analyses of monthly felony murder rates, the frequency of executions, and the amount and type of television coverage of executions over the period. The analyses revealed occasional departures (for vehicle theft and narcotics killings) from the null hypotheses. However, on balance, and in line with the vast majority of capital punishment studies, this investigation found no consistent evidence that executions and the television coverage they receive are associated significantly with rates for total, index, or different types of felony murder
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