701 research outputs found
Biologically Significant Illinois Streams: An Evaluation of the Streams of Illinois based on Aquatic Biodiversity: Part 1
Part 1: Text. See Reference ID-1365 for Part 2: AtlasReport issued on: December 31, 1991INHS Technical Report prepared for Illinois Dept. of Conservation, Illinois Dept. of
Energy and Natural Resource
Some unusual natural areas in Illinois
Bibliography: p. 42-43
Biological Assessments of Six Selected Fishes, Amphibians, and Mussels in Illinois
ID: 8758; issued November 1, 1996INHS Technical Report prepared for Illinois Department of Natural Resources, Division of
Natural Heritag
Chapter 9: Aquatic Macroinvertebrates, Section A: Aquatic Macroinvertebrates (Exclusive of Mosquitoes)
Final Report. Excerpt (Chapter 9, Section A) from The Des Plaines River Wetlands
Demonstration Project, Volume II, Baseline Survey, edited by Donald L. Hey and Nancy S.
PhilippiReport issued on: October 1985INHS Technical Report prepared for Wetlands Research, Inc
Wikipedia as an encyclopaedia of life
In his 2003 essay E O Wilson outlined his vision for an “encyclopaedia of life” comprising “an electronic page for each species of organism on Earth”, each page containing “the scientific name of the species, a pictorial or genomic presentation of the primary type specimen on which its name is based, and a summary of its diagnostic traits.” Although the “quiet revolution” in biodiversity informatics has generated numerous online resources, including some directly inspired by Wilson's essay (e.g., "http://ispecies.org":http://ispecies.org, "http://www.eol.org":http://www.eol.org), we are still some way from the goal of having available online all relevant information about a species, such as its taxonomy, evolutionary history, genomics, morphology, ecology, and behaviour. While the biodiversity community has been developing a plethora of databases, some with overlapping goals and duplicated content, Wikipedia has been slowly growing to the point where it now has over 100,000 pages on biological taxa. My goal in this essay is to explore the idea that, largely independent of the efforts of biodiversity informatics and well-funded international efforts, Wikipedia ("http://en.wikipedia.org/wiki/Main_Page":http://en.wikipedia.org/wiki/Main_Page) has emerged as potentially the best platform for fulfilling E O Wilson’s vision
Factorized Graph Representations for Semi-Supervised Learning from Sparse Data
Node classification is an important problem in graph data management. It is
commonly solved by various label propagation methods that work iteratively
starting from a few labeled seed nodes. For graphs with arbitrary
compatibilities between classes, these methods crucially depend on knowing the
compatibility matrix that must be provided by either domain experts or
heuristics. Can we instead directly estimate the correct compatibilities from a
sparsely labeled graph in a principled and scalable way? We answer this
question affirmatively and suggest a method called distant compatibility
estimation that works even on extremely sparsely labeled graphs (e.g., 1 in
10,000 nodes is labeled) in a fraction of the time it later takes to label the
remaining nodes. Our approach first creates multiple factorized graph
representations (with size independent of the graph) and then performs
estimation on these smaller graph sketches. We define algebraic amplification
as the more general idea of leveraging algebraic properties of an algorithm's
update equations to amplify sparse signals. We show that our estimator is by
orders of magnitude faster than an alternative approach and that the end-to-end
classification accuracy is comparable to using gold standard compatibilities.
This makes it a cheap preprocessing step for any existing label propagation
method and removes the current dependence on heuristics.Comment: SIGMOD 2020 (Extended version
An Observational Determination of the Bolometric Quasar Luminosity Function
We combine a large set of quasar luminosity function (QLF) measurements from
the rest-frame optical, soft and hard X-ray, and near- and mid-infrared bands
to determine the bolometric QLF in the redshift interval z=0-6. Accounting for
the observed distributions of quasar column densities and variation of spectral
energy distribution (SED) shapes, and their dependence on luminosity, makes it
possible to integrate the observations in a reliable manner and provides a
baseline in redshift and luminosity larger than that of any individual survey.
We infer the QLF break luminosity and faint-end slope out to z~4.5 and confirm
at high significance (>10sigma) previous claims of a flattening in both the
faint- and bright-end slopes with redshift. With the best-fit estimates of the
column density distribution and quasar SED, which both depend on luminosity, a
single bolometric QLF self-consistently reproduces the observed QLFs in all
bands and at all redshifts for which we compile measurements. Ignoring this
luminosity dependence does not yield a self-consistent bolometric QLF and there
is no evidence for any additional dependence on redshift. We calculate the
expected relic black hole mass function and mass density, cosmic X-ray
background, and ionization rate as a function of redshift and find they are
consistent with existing measurements. The peak in the total quasar luminosity
density is well-constrained at z=2.15+/-0.05. We provide a number of fitting
functions to the bolometric QLF and its manifestations in various bands, and a
script to return the QLF at arbitrary frequency and redshift from these fits,
as the most simple inferences from the QLF measured in a single band can be
misleading.Comment: 24 pages, 11 figures. Submitted to ApJ. A routine to return the QLF
from the fits herein is available at
http://www.cfa.harvard.edu/~phopkins/Site/qlf.htm
The XMM large scale structure survey: optical vs. X-ray classifications of active galactic nuclei and the unified scheme
Our goal is to characterize AGN populations by comparing their X-ray and
optical classifications. We present a sample of 99 spectroscopically identified
X-ray point sources in the XMM-LSS survey which are significantly detected in
the [2-10] keV band, and with more than 80 counts. We performed an X-ray
spectral analysis for all of these 99 X-ray sources. Introducing the fourfold
point correlation coefficient, we find only a mild correlation between the
X-ray and the optical classifications, as up to 30% of the sources have
differing X-ray and optical classifications: on one hand, 10% of the type 1
sources present broad emission lines in their optical spectra and strong
absorption in the X-rays. These objects are highly luminous AGN lying at high
redshift and thus dilution effects are totally ruled out, their discrepant
nature being an intrinsic property. Their X-ray luminosities and redshifts
distributions are consistent with those of the unabsorbed X-ray sources with
broad emission lines. On the other hand, 25/32 are moderate luminosity AGN,
which are both unabsorbed in the X-rays and only present narrow emission lines
in their optical spectra. The majority of them have an optical spectrum which
is representative of the host galaxy. We finally infer that dilution of the AGN
by the host galaxy seems to account for their nature. 5/25 have been defined as
Seyfert 2. In conclusion, most of these 32 discrepant cases can be accounted
for by the standard AGN unified scheme, as its predictions are not met for only
12% of the 99 X-ray sources. ABRIDGEDComment: 25 pages, 19 figures, Accepted for publication in A&
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