2,665 research outputs found
AN ECONOMIC ASSESSMENT OF WETLAND MITIGATION IN NORTHWEST MINNESOTA
The economic efficiency of wetland mitigation in Minnesota's Red River Valley was examined using the Minnesota Routine Assessment Method on ten wetland case studies to rate the functions of impacted and replacement wetlands. Secondary sources were used to assign dollar values to wetland functions of impacted and replacement wetlands. Mitigation costs for projects ranged from 4,171 per acre. Estimated annual social values ranged from 1,027 per acre for impacted wetlands and from 927 per acre for replacement wetlands. Social values of replacement wetlands exceeded the social value of impacted wetlands in seven cases. Values of replacement wetlands were 1.8 to 4 times greater than the values of impacted wetlands due to 2-to-1 replacement ratios. When society gains benefits from mitigation, public cost-sharing may be appropriate. In one case the value of the impacted wetlands was higher than the value of the replacement wetland. There were insufficient data to evaluate two cases. Results are only indicators of efficiency, since not all social costs and benefits of the impact-mitigation activity are addressed by legislation. These results suggest wetland mitigation policy in Minnesota needs to be reevaluated if efficient use of society's resources is a legislative goal.Wetland(s), mitigation, economics, values, Minnesota, Red River, Wetland Conservation Act, Minnesota Routine Assessment Method, restoration, Land Economics/Use,
The Role of Chromatin Modifications in the Evolution of Giant Plant Genomes.
Angiosperm genome sizes (GS) range ~2400-fold and comprise genes and their regulatory regions, repeats, semi-degraded repeats, and 'dark matter'. The latter represents repeats so degraded that they can no longer be recognised as repetitive. In exploring whether the histone modifications associated with chromatin packaging of these contrasting genomic components are conserved across the diversity of GS in angiosperms, we compared immunocytochemistry data for two species whose GS differ ~286-fold. We compared published data for Arabidopsis thaliana with a small genome (GS = 157 Mbp/1C) with newly generated data from Fritillaria imperialis, which has a giant genome (GS = 45,000 Mbp/1C). We compared the distributions of the following histone marks: H3K4me1, H3K4me2, H3K9me1, H3K9me2, H3K9me3, H3K27me1, H3K27me2, and H3K27me3. Assuming these histone marks are associated with the same genomic features across all species, irrespective of GS, our comparative analysis enables us to suggest that while H3K4me1 and H3K4me2 methylation identifies genic DNA, H3K9me3 and H3K27me3 marks are associated with 'dark matter', H3K9me1 and H3K27me1 mark highly homogeneous repeats, and H3K9me2 and H3K27me2 mark semi-degraded repeats. The results have implications for our understanding of epigenetic profiles, chromatin packaging and the divergence of genomes, and highlight contrasting organizations of the chromatin within the nucleus depending on GS itself
Researching creatively with pupils in Assessment for Learning (AfL) classrooms on experiences of participation and consultation
This paper reports on an ESRC TLRP project, Consulting Pupils on the Assessment of their Learning (CPAL). The CPAL project provides an additional theoretical perspective to the âeducational benefitsâ perspective of engaging pupil voice in learning and teaching (Rudduck et al., 2003) through its exploration of pupil rights specifically in relation to assessment issues presently on the policy agenda in the Northern Ireland context â notably Assessment for Learning (AfL). An emergent framework for assessing pupil rights, based on Article 12 of the United Nations Convention on the Rights of the Child (Lundy, 2007), is being used to explore the ways in which AfL classroom practice creates the conditions for increased pupil participation and consultation. Pupil views on their AfL classroom experiences and participation are explored by means of a variety of pupil-centred, creative research methods that engage and stimulate pupils to observe, communicate and analyse their learning and assessment experiences and give meaning to them. This presentation highlights preliminary data based on a sample of 11-14 years pupils' experiences of participation and consultation in classrooms adopting AfL pedagogical principles, and identifies characteristics that support or inhibit pupil participation in their learning and the expression of their views about such matters
A Sunyaev-Zel'dovich Effect Survey for High Redshift Clusters
Interferometric observations of the Sunyaev-Zel'dovich Effect (SZE) toward
clusters of galaxies provide sensitive cosmological probes. We present results
from 1 cm observations (at BIMA and OVRO) of a large, intermediate redshift
cluster sample. In addition, we describe a proposed, higher sensitivity array
which will enable us to survey large portions of the sky. Simulated
observations indicate that we will be able to survey one square degree of sky
per month to sufficient depth that we will detect all galaxy clusters more
massive than 2x10^{14} h^{-1}_{50}M_\odot, regardless of their redshift. We
describe the cluster yield and resulting cosmological constraints from such a
survey.Comment: 7 pages, 6 figures, latex, contribution to VLT Opening Symposiu
Cosmological Parameter Extraction from the First Season of Observations with DASI
The Degree Angular Scale Interferometer (\dasi) has measured the power
spectrum of the Cosmic Microwave Background anisotropy over the range of
spherical harmonic multipoles 100<l<900. We compare this data, in combination
with the COBE-DMR results, to a seven dimensional grid of adiabatic CDM models.
Adopting the priors h>0.45 and 0.0<=tau_c<=0.4, we find that the total density
of the Universe Omega_tot=1.04+/-0.06, and the spectral index of the initial
scalar fluctuations n_s=1.01+0.08-0.06, in accordance with the predictions of
inflationary theory. In addition we find that the physical density of baryons
Omega_b.h^2=0.022+0.004-0.003, and the physical density of cold dark matter
Omega_cdm.h^2=0.14+/-0.04. This value of Omega_b.h^2 is consistent with that
derived from measurements of the primordial abundance ratios of the light
elements combined with big bang nucleosynthesis theory. Using the result of the
HST Key Project h=0.72+/-0.08 we find that Omega_t=1.00+/-0.04, the matter
density Omega_m=0.40+/-0.15, and the vacuum energy density
Omega_lambda=0.60+/-0.15. (All 68% confidence limits.)Comment: 7 pages, 4 figures, minor changes in response to referee comment
Geometric Parameterization of Absorption in Heavy Ion Collisions
We calculate the survival probability of particles in various
colliding systems using a Glauber model. An analysis of recent data has
reported a -nucleon breakup cross section of 6.20.7 mb derived
from an exponential fit to the ratio of to Drell-Yan yields as a
function of a simple, linearly-averaged mean path length through the nuclear
medium. Our calculations indicate that, due to the nature of the calculation,
this approach yields an apparent breakup cross section which is systematically
lower than the actual value.Comment: LaTex, 7 pages, 2 figure
Polarization Diffusion from Spacetime Uncertainty
A model of Lorentz invariant random fluctuations in photon polarization is
presented. The effects are frequency dependent and affect the polarization of
photons as they propagate through space. We test for this effect by confronting
the model with the latest measurements of polarization of Cosmic Microwave
Background (CMB) photons.Comment: 4 pages, 1 figur
DASI First Results: A Measurement of the Cosmic Microwave Background Angular Power Spectrum
We present measurements of anisotropy in the Cosmic Microwave Background
(CMB) from the first season of observations with the Degree Angular Scale
Interferometer (DASI). The instrument was deployed at the South Pole in the
austral summer 1999--2000, and made observations throughout the following
austral winter. We have measured the angular power spectrum of the CMB in the
range 100<l<900 with high signal-to-noise. In this paper we review the
formalism used in the analysis, in particular the use of constraint matrices to
project out contaminants such as ground and point source signals, and to test
for correlations with diffuse foreground templates. We find no evidence of
foregrounds other than point sources in the data, and find a maximum likelihood
temperature spectral index beta = -0.1 +/- 0.2 (1 sigma), consistent with CMB.
We detect a first peak in the power spectrum at l approx 200, in agreement with
previous experiments. In addition, we detect a peak in the power spectrum at l
approx 550 and power of similar magnitude at l approx 800 which are consistent
with the second and third harmonic peaks predicted by adiabatic inflationary
cosmological models.Comment: 8 pages, 1 figure, minor changes in response to referee comment
Second and third season QUaD CMB temperature and polarization power spectra
We report results from the second and third seasons of observation with the
QUaD experiment. Angular power spectra of the Cosmic Microwave Background are
derived for both temperature and polarization at both 100 GHz and 150 GHz, and
as cross frequency spectra. All spectra are subjected to an extensive set of
jackknife tests to probe for possible systematic contamination. For the
implemented data cuts and processing technique such contamination is
undetectable. We analyze the difference map formed between the 100 and 150 GHz
bands and find no evidence of foreground contamination in polarization. The
spectra are then combined to form a single set of results which are shown to be
consistent with the prevailing LCDM model. The sensitivity of the polarization
results is considerably better than that of any previous experiment -- for the
first time multiple acoustic peaks are detected in the E-mode power spectrum at
high significance.Comment: 24 pages, 23 figures, updated to reflect published versio
Genomic repeat abundances contain phylogenetic signal
A large proportion of genomic information, particularly repetitive elements, is usually ignored when researchers are using next-generation sequencing. Here we demonstrate the usefulness of this repetitive fraction in phylogenetic analyses, utilizing comparative graph-based clustering of next-generation sequence reads, which results in abundance estimates of different classes of genomic repeats. Phylogenetic trees are then inferred based on the genome-wide abundance of different repeat types treated as continuously varying characters; such repeats are scattered across chromosomes and in angiosperms can constitute a majority of nuclear genomic DNA. In six diverse examples, five angiosperms and one insect, this method provides generally well-supported relationships at interspecific and intergeneric levels that agree with results from more standard phylogenetic analyses of commonly used markers. We propose that this methodology may prove especially useful in groups where there is little genetic differentiation in standard phylogenetic markers. At the same time as providing data for phylogenetic inference, this method additionally yields a wealth of data for comparative studies of genome evolution
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