26,893 research outputs found
A Bait Attractant Study of the Nitidulidae (Coleoptera) at Shawnee State Forest in Southern Ohio
Four baits were tested for efficacy in attracting sap beetles (Nitidulidae) at two sites in the Shawnee State Forest over two collection periods in 1992. Species taken were categorized into three groups: abundant, moderate, and uncommon. At Site 1, nitidulids displayed a strong preference for whole wheat bread dough, followed by fermenting brown sugar, and fermenting malt/molasses solution, and vinegar, respectively. Site 2 collections showed a similar trend to Site 1, but the order of preference was switched for brown sugar and malt/molasses solution. Of the 20 species collected, six species were abundant, seven species were moderate, and seven species were locally uncommon
Jet Investigations Using the Radial Moment
We define the radial moment, , for jets produced in hadron-hadron
collisions. It can be used as a tool for studying, as a function of the jet
transverse energy and pseudorapidity, radiation within the jet and the quality
of a perturbative description of the jet shape. We also discuss how
non-perturbative corrections to the jet transverse energy affect .Comment: 14 pages, LaTeX, 6 figure
Effects of Higher-Order Threshold Corrections in High-E_T Jet Production
Results for higher-order threshold enhancements in high-E_T jet production in
hadron-hadron collisions are presented. Expressions are given for the
next-to-next-to-leading order (NNLO) threshold corrections to the single-jet
inclusive cross section at next-to-leading logarithmic (NLL) accuracy. The
corrections are found to be small for the specific choice of E_T/2 for the
factorization and renormalization scales, and the corrected cross section shows
a substantial reduction of the scale dependence. A comparison to experimental
results from the Tevatron is presented.Comment: 24 pages LaTeX, 5 figure
Synchrotron Radiation and Quantum Gravity
Photons may evade a synchrotron radiation constraint on quantum gravity by
violating the equivalence principle.Comment: 4 pages. Comment on Jacobson et al astro-ph/0212190. Presentation
revised for brief communication to Nature with extended bibliograph
Quantum-Gravity Analysis of Gamma-Ray Bursts using Wavelets
In some models of quantum gravity, space-time is thought to have a foamy
structure with non-trivial optical properties. We probe the possibility that
photons propagating in vacuum may exhibit a non-trivial refractive index, by
analyzing the times of flight of radiation from gamma-ray bursters (GRBs) with
known redshifts. We use a wavelet shrinkage procedure for noise removal and a
wavelet `zoom' technique to define with high accuracy the timings of sharp
transitions in GRB light curves, thereby optimizing the sensitivity of
experimental probes of any energy dependence of the velocity of light. We apply
these wavelet techniques to 64 ms and TTE data from BATSE, and also to OSSE
data. A search for time lags between sharp transients in GRB light curves in
different energy bands yields the lower limit GeV on
the quantum-gravity scale in any model with a linear dependence of the velocity
of light . We also present a limit on any quadratic dependence.Comment: This version is accepted for publication in Astronomy & Astrophysics.
The discussion and introduction are extended making clear why the wavelet
analysis should be superior to straight cross-correlation analysis. More
details on compiled data are elaborated. 18 pages, 9 figures, A&A forma
Waves on Noncommutative Spacetime and Gamma-Ray Bursts
Quantum group Fourier transform methods are applied to the study of processes
on noncommutative Minkowski spacetime . A natural
wave equation is derived and the associated phenomena of {\it in vacuo}
dispersion are discussed. Assuming the deformation scale is of the
order of the Planck length one finds that the dispersion effects are large
enough to be tested in experimental investigations of astrophysical phenomena
such as gamma-ray bursts. We also outline a new approach to the construction of
field theories on the noncommutative spacetime, with the noncommutativity
equivalent under Fourier transform to non-Abelianness of the `addition law' for
momentum in Feynman diagrams. We argue that CPT violation effects of the type
testable using the sensitive neutral-kaon system are to be expected in such a
theory.Comment: 25 page
A Migration Study of \u3ci\u3eStelidota Geminata\u3c/i\u3e (Coleoptera: Nitidulidae)
The strawberry sap beetle, Stelidota geminata (Say), is a major pest of strawberries in the northeastern United States. Further knowledge of the migratory habits of this insect pest can enhance the effectiveness of pest management strategies. This nitidulid was shown to migrate from its overwintering sites to one of its primary reproductive sites, strawberry fields, in late May. The beetle population peaked in the third week in July, 1993 in the strawberry field and then gradually declined. In 1994, the peak, as well as the total population, was much greater than in 1993. Furthermore, S. geminata was concentrated in the transition areas surrounding the strawberry fields prior to the ripening of the fruit
A Complete Year of User Retrieval Sessions in a Social Sciences Academic Search Engine
In this paper, we present an open data set extracted from the transaction log
of the social sciences academic search engine sowiport. The data set includes a
filtered set of 484,449 retrieval sessions which have been carried out by
sowiport users in the period from April 2014 to April 2015. We propose a
description of interactions performed by the academic search engine users that
can be used in different applications such as result ranking improvement, user
modeling, query reformulation analysis, search pattern recognition.Comment: 6 pages, 2 figures, accepted short paper at the 21st International
Conference on Theory and Practice of Digital Libraries (TPDL 2017
Recommended from our members
Bacterial pathogens and resistance causing community acquired paediatric bloodstream infections in low- and middle-income countries: a systematic review and meta-analysis
Background
Despite a high mortality rate in childhood, there is limited evidence on the causes and outcomes of paediatric bloodstream infections from low- and middle-income countries (LMICs). We conducted a systematic review and meta-analysis to characterize the bacterial causes of paediatric bloodstream infections in LMICs and their resistance profile.
Methods
We searched Pubmed and Embase databases between January 1st 1990 and October 30th 2019, combining MeSH and free-text terms for “sepsis” and “low-middle-income countries” in children. Two reviewers screened articles and performed data extraction to identify studies investigating children (1 month-18 years), with at least one blood culture. The main outcomes of interests were the rate of positive blood cultures, the distribution of bacterial pathogens, the resistance patterns and the case-fatality rate. The proportions obtained from each study were pooled using the Freeman-Tukey double arcsine transformation, and a random-effect meta-analysis model was used.
Results
We identified 2403 eligible studies, 17 were included in the final review including 52,915 children (11 in Africa and 6 in Asia). The overall percentage of positive blood culture was 19.1% [95% CI: 12.0–27.5%]; 15.5% [8.4–24.4%] in Africa and 28.0% [13.2–45.8%] in Asia. A total of 4836 bacterial isolates were included in the studies; 2974 were Gram-negative (63.9% [52.2–74.9]) and 1858 were Gram-positive (35.8% [24.9–47.5]). In Asia, Salmonella typhi (26.2%) was the most commonly isolated pathogen, followed by Staphylococcus aureus (7.7%) whereas in Africa, S. aureus (17.8%) and Streptococcus pneumoniae (16.8%) were predominant followed by Escherichia coli (10.7%). S. aureus was more likely resistant to methicillin in Africa (29.5% vs. 7.9%), whereas E. coli was more frequently resistant to third-generation cephalosporins (31.2% vs. 21.2%), amikacin (29.6% vs. 0%) and ciprofloxacin (36.7% vs. 0%) in Asia. The overall estimate for case-fatality rate among 8 studies was 12.7% [6.6–20.2%]. Underlying conditions, such as malnutrition or HIV infection were assessed as a factor associated with bacteraemia in 4 studies each.
Conclusions
We observed a marked variation in pathogen distribution and their resistance profiles between Asia and Africa. Very limited data is available on underlying risk factors for bacteraemia, patterns of treatment of multidrug-resistant infections and predictors of adverse outcomes
Astrophysical Probes of the Constancy of the Velocity of Light
We discuss possible tests of the constancy of the velocity of light using
distant astrophysical sources such as gamma-ray bursters (GRBs), Active
Galactic Nuclei (AGNs) and pulsars. This speculative quest may be motivated by
some models of quantum fluctuations in the space-time background, and we
discuss explicitly how an energy-dependent variation in photon velocity \delta
c/ c \sim - E / M arises in one particular quantum-gravitational model. We then
discuss how data on GRBs may be used to set limits on variations in the
velocity of light, which we illustrate using BATSE and OSSE observations of the
GRBs that have recently been identified optically and for which precise
redshifts are available. We show how a regression analysis can be performed to
look for an energy-dependent effect that should correlate with redshift. The
present data yield a limit M \gsim 10^{15} GeV for the quantum gravity scale.
We discuss the prospects for improving this analysis using future data, and how
one might hope to distinguish any positive signal from astrophysical effects
associated with the sources.Comment: 37 pages LaTeX, 9 eps figures included, uses aasms4.st
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