4,514 research outputs found
Almost Split Morphisms, Preprojective Algebras and Multiplication Maps of Maximal Rank
With a grading previously introduced by the second-named author, the
multiplication maps in the preprojective algebra satisfy a maximal rank
property that is similar to the maximal rank property proven by Hochster and
Laksov for the multiplication maps in the commutative polynomial ring. The
result follows from a more general theorem about the maximal rank property of a
minimal almost split morphism, which also yields a quadratic inequality for the
dimensions of indecomposable modules involved
The effect of sewage sludge application to an agricultural soil on the fecundity of the Rose Grain aphid (Metopolophium dirhodum).
A pot trial was used to assess the effect of amending soil with sewage sludge on the number of offspring produced by individual Rose Grain Aphids. Results demonstrated that the highest application rate (100 t.d.s. ha-1) could significantly decrease the number of offspring produced by the aphid
Do aphids biomagnify Cd and Zn as a defence against predation?
The results of a study on sewage sludge application to agricultural soil have led us to propose that recycling sewage sludge can affect the biological control of grain aphids. This, we suggest, is due to the biomagnification of trace metals in the aphid presenting potentially toxic concentrations to predators
Combining diverse data sources for CEDSS, an agent-based model of domestic energy demand
CEDSS (Community Energy Demand Social Simulator) is an empirical agent-based model
designed and built as part of a multi-method social science project investigating the determinants
of domestic energy demand. Ideally, empirical modellers, within and beyond social simulation,
would prefer to work from an integrated dataset, gatheredfor the purposes of developing the model.
In practice, many have to work with less than ideal data, often including processed data from
multiple sources external to the project. Moreover, what data will be required may not be clear at
the start of the project. This paper describes the approach to dealing with these factors taken in
developing CEDSS, and presents the completed model together with an outline of the calibration
and validation procedure used. The discussion section draws together the most distinctive features
of empirical data collection, processing and use for and in CEDSS, and argues that the approach
taken is sufficiently robust to underpin the model’s purpose – to generate scenarios of domestic
energy demand to 2049
Causal inference for social network data
We describe semiparametric estimation and inference for causal effects using
observational data from a single social network. Our asymptotic result is the
first to allow for dependence of each observation on a growing number of other
units as sample size increases. While previous methods have generally
implicitly focused on one of two possible sources of dependence among social
network observations, we allow for both dependence due to transmission of
information across network ties, and for dependence due to latent similarities
among nodes sharing ties. We describe estimation and inference for new causal
effects that are specifically of interest in social network settings, such as
interventions on network ties and network structure. Using our methods to
reanalyze the Framingham Heart Study data used in one of the most influential
and controversial causal analyses of social network data, we find that after
accounting for network structure there is no evidence for the causal effects
claimed in the original paper
Near-Saturation Conditions at the Tropical Tropopause: Results from Ticosonde
The TTL lies between the neutral buoyancy level (NBL) at ~350 K and the tropopause. Within the the TTL radiative heating drives ascent and air parcel supersaturation. Ticosonde measurements since 2005 show that the incidence ofsupersaturation in the TTL over Costa Rica is ~60%. This is due to diabatic ascent. The frequency is highest (68%) in summer, when convection is frequent. The TSL was defined by Selkirk et al. (2010) as the upper edge of the TTL. It isIn this layer that the final saturation of air parcels rising into the stratosphere occurs and thus the water vapor minima which define the so-called "writehead" of the Atmospheric Tape Recorder
Strictly Anomaly Mediated Supersymmetry Breaking
We consider an MSSM extension with anomaly mediation as the source of
supersymmetry-breaking, and a U(1) symmetry which solves the tachyonic slepton
problem, and introduces both the see-saw mechanism for neutrino masses, and the
Higgs mu-term. We compare its spectra with those from so-called minimal anomaly
mediated supersymmetry breaking. We find a Standard Model-like Higgs of mass
125 GeV with a gravitino mass of 140 TeV and tan(beta)=16. However, the muon
anomalous magnetic moment is 3 sigma away from the experimental value.
The model naturally produces a period of hybrid inflation, which can exit to
a false vacuum characterised by large Higgs vevs, reaching the true ground
state after a period of thermal inflation. The scalar spectral index is reduced
to approximately 0.975, and the correct abundance of neutralino dark matter can
be produced by decays of thermally-produced gravitinos, provided the gravitino
mass (and hence the Higgs mass) is high. Naturally light cosmic strings are
produced, satisfying bounds from the Cosmic Microwave Background. The
complementary pulsar timing and cosmic ray bounds require that strings decay
primarily via loops into gravitational waves. Unless the loops are extremely
small, the next generation pulsar timing array will rule out or detect the
string-derived gravitational radiation background in this model.Comment: 38 pages, 1 figure. Discussion of 125GeV Higgs possibility, and of
U(1) decoupling limi
Interactive Neural Resonators
In this work, we propose a method for the controllable synthesis of real-time
contact sounds using neural resonators. Previous works have used physically
inspired statistical methods and physical modelling for object materials and
excitation signals. Our method incorporates differentiable second-order
resonators and estimates their coefficients using a neural network that is
conditioned on physical parameters. This allows for interactive dynamic control
and the generation of novel sounds in an intuitive manner. We demonstrate the
practical implementation of our method and explore its potential creative
applications
Sexual Harassment in Our Schools; and How to Stop Sexual Harassment in Our Schools [book reviews]
Book reviews of: Sexual Harassment in Our Schools: What Parents and Teachers Need to Know to Spot It and Stop It, by Robert J. Shoop and Jack W. Hayhow, Jr. ; and How to Stop Sexual Harassment in Our Schools: A Handbook and Curriculum Guide for Administrators and Teachers, by Robert J. Shoop and Debra J. Edwards
- …