23,940 research outputs found
Continuous functions on products of compact Hausdorff spaces
We investigated the spaces of continuous functions on countable products of compact Hausdorff spaces. Our main object here is to extend the discussion to arbitrary products of compact Hausdorff spaces. We prove the following theorems in Section 3
Does environment affect the star formation histories of early-type galaxies?
Differences in the stellar populations of galaxies can be used to quantify
the effect of environment on the star formation history. We target a sample of
early-type galaxies from the Sloan Digital Sky Survey in two different
environmental regimes: close pairs and a general sample where environment is
measured by the mass of their host dark matter halo. We apply a blind source
separation technique based on principal component analysis, from which we
define two parameters that correlate, respectively, with the average stellar
age (eta) and with the presence of recent star formation (zeta) from the
spectral energy distribution of the galaxy. We find that environment leaves a
second order imprint on the spectra, whereas local properties - such as
internal velocity dispersion - obey a much stronger correlation with the
stellar age distribution.Comment: 5 pages, 2 figures. Proceedings of JENAM 2010, Symposium 2:
"Environment and the formation of galaxies: 30 years later
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Research Factsheet: Woodfuel experiment - North Thurlbar, Newton Rigg
An experiment has been set up to assess the economic viability and environmental impacts of woodfuel harvesting in North Thurlbar, a small wood land on the University of Cumbria Newton Rigg campus estate. This factsheet describes the aim of the study and the experiment design
THE CYCLICAL NATURE OF POLITICS AND THE U.S. FOOD SYSTEM
Agricultural and Food Policy, Political Economy,
Sub-wavelength focusing meta-lens
We show that planar a plasmonic metamaterial with spatially variable
meta-atom parameters can focus transmitted light into sub-wavelength hot-spots
located beyond the near-field of the metamaterial. By nano-structuring a gold
film we created an array of meta-lenses generating foci of 160 nm
(0.2{\lambda}) in diameter when illuminated by a wavelength of 800 nm. We
attribute the occurrence of sub-wavelength hotspots beyond the near field to
the phenomenon of superoscillation
Impaired interferon-Îł responses, increased interleukin-17 expression, and a tumor necrosis factorâα transcriptional program in invasive aspergillosis
This article is available open access through the publisherâs website. Copyright @ 2009 Oxford University Press.Background - Invasive aspergillosis (IA) is the most common cause of death associated with fungal infection in the developed world. Historically, susceptibility to IA has been associated with prolonged neutropenia; however, IA has now become a major problem in patients on calcineurin inhibitors and allogenic hematopoetic stem cell transplant patients following engraftment. These observations suggest complex cellular mechanisms govern immunity to IA. Methods - To characterize the key early events that govern outcome from infection with Aspergillus fumigatus we performed a comparative immunochip microarray analysis of the pulmonary transcriptional response to IA between cyclophosphamide-treated mice and immunocompetent mice at 24 h after infection. Results - We demonstrate that death due to infection is associated with a failure to generate an incremental interferon-Îł response, increased levels of interleukin-5 and interleukin-17a transcript, coordinated expression of a network of tumor necrosis factorâα-related genes, and increased levels of tumor necrosis factorâα. In contrast, clearance of infection is associated with increased expression of a number genes encoding proteins involved in innate pathogen clearance, as well as apoptosis and control of inflammation. Conclusion - This first organ-level immune response transcriptional analysis for IA has enabled us to gain new insights into the mechanisms that govern fungal immunity in the lung.The BBSRC, CGD Research Trust, and the MRC
Case-Building Behavior, Persistence, and Emergence Success of \u3ci\u3ePycnopsyche Guttifer\u3c/i\u3e (Walker) (Trichoptera: Limnephilidae) in Laboratory and \u3ci\u3ein situ\u3c/i\u3e Environments: Potential Trade-Offs of Material Preference
When removed from their cases in a non-flow laboratory environment, 5th instar Pycnopsyche guttifer (Walker) larvae were always successful in constructing a new case within 24 h when woody debris was present as a material choice. Most were successful within 1 h. Larvae were never successful at case building in the absence of wood in a non-flow environment. These laboratory-constructed âemergency casesâ were flimsy, lacking in shape, and larger than field cases. Laboratory case size, shape, and material preference remained constant after repeated daily evacuations over a series of 10 days. Larvae could be induced to construct a case composed of mineral particles only in the absence of wood and when placed in a laboratory stream with simulated flow conditions, or in situ in a natural stream. The emergence success of P. guttifer specimens induced to build these mineral cases, however, was significantly higher than that of larvae remaining in their field cases or of larvae that built wood cases. This result is likely due to a fungal infection that affected only larvae in wood cases. Our results demonstrate a scenario where a clearly non-preferred case construction material appears to increase survival
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