6,389 research outputs found
The milliped genus Euryurus Koch, 1847 (Polydesmida: Euryuridae) west of the Mississippi River; occurrence of E. leachii (Gray, 1832) on Crowley’s Ridge, Arkansas
The milliped genus Euryurus Koch, 1847, and the species, E. leachii (Gray, 1832) (Polydesmida: Euryuridae), are recorded from three sites on the northern part of Crowley’s Ridge (Cross, Lee, and Poinsett counties), Arkansas, where the only prior familial records are of Auturus evides (Bollman, 1887). Coupled with the published locality of E. leachii in Phillips Co., at the southern extremity of the Ridge, the only known occurrences of both the genus and species in Arkansas and west of the Mississippi River are in this physiographic feature. The Arkansas population is geographically peripheral but anatomically intermediate between the two recognized subspecies, E. l. leachii and E. l. fraternus Hoffman, 1978, and we do not assign it to a race. Molecular investigations seem necessary to resolve relationships in the “E. leachii complex.
Monoaromatic compounds in ambient air of various cities: A focus on correlations between the xylenes and ethylbenzene
Speciation of o-xylene, m-xylene, p-xylene and ethylbenzene was performed by gas chromatography from ambient air and liquid fuel samples collected at various locations in 19 cities in Europe, Asia and South America. The xylene's mixing ratios were compared to each other from the various locations, which included urban air, traffic air and liquid fuel. For all samples, the xylenes exhibited robust correlations, and the slopes remained constant. The m-xylene/p-xylene ratio was found to be 2.33±0.30, and the m-xylene/o-xylene ratio was found to be 1.84±0.25. These ratios remain persistent even in biomass combustion experiments (in South America and South Africa). Comparing the xylenes to toluene and benzene indicate that combustion, but not fuel evaporation, is the major common source of the xylenes in areas dominated by automotive emissions. Although a wide range of combustion types and combustion efficiencies were encountered throughout all the locations investigated, xylenes and ethylbenzene ratios remained persistent. We discuss the implications of the constancies in the xylenes and ethylbenzene ratios on atmospheric chemistry
Nicotine Exposure Rescues the Locomotory Defects of TRPA1 Loss of Function Flies
Nicotine is a very common substance: it is a plant-produced pesticide and is frequently used as a stimulant for humans. It is toxic at high doses and can cause nicotine poisoning, which is harmful for humans and lethal in flies (Velazquez-Ulloa, 2017). Experiments have identified that nicotine exposure affects the TRPA1 chemosensory cation channel (Talavera et al., 2016; Kang et al., 2010). Previously, student data has shown that nicotine exposure extends the lifespan of TRPA1 mutant flies compared to a control group of wild type flies. TRPA1 is responsible for thermotaxis and pain reception (Neely et al., 2007). These experiments seek to find a link between exposure to nicotine and survivability of TRPA1 loss of function flies via exposure to sub-lethal concentrations of nicotine. After understanding survivability to nicotine exposure, circadian rhythm and motor activity using a DAM (Drosophila activity monitor), will be measured. TRPA1 mutant, nicotine-exposed flies are expected to survive and exhibit increased locomotion as adults compared to wild type flies
Sea salt as a potential ocean mirror material
One way to increase planetary albedo in order to ameliorate global warming is to use ocean foams. The
energy needed to maintain such foams, even if drawn from wave or wind is high and so they must be
persistent, ideally surviving up to a month. While studying combinations of surfactants and gelling agents
to make long-lived foams in salt water, it was apparent that some foams developed progressively higher
reflectance as the upper surface dried. Scanning electron microscopy of the upper surface revealed
0.5 mm, near-monodisperse salt crystals. Thus with a refractive index of ∼1.5, sea salt, being in somewhat
prodigious supply, now enters the arena as a potential mirror material. Its reflectance depends on the
microstructure, specifically on the inhibition of Ostwald ripening. Studies were therefore carried out to
investigate particle size effects in a membrane such as a foamed gel in which seawater dries on the
upper surface. It was demonstrated that the organic additives used to create foam persistence also
mediated sea salt crystallisation and in this way drastically modified the reflectance of the upper layer.
These experiments suggest a new direction of research in planetary surface albedo modification
Distribution of \u3ci\u3eAbacion texense\u3c/i\u3e (Loomis, 1937), the only milliped species traversing the Rio Grande, Mississippi, and Pecos rivers (Callipodida: Abacionidae)
Localities are documented for the milliped Abacion texense (Loomis, 1837) (Callipodida: Abacionidae) whose distribution forms both the northern and southern ordinal limits in the Western Hemisphere. The westernmost component of Abacion Rafinesque, 1820, A. texense is the only milliped species whose range spans the Mississippi and Pecos rivers and the Rio Grande. Distribution extremes are in Hennepin County (Co.), Minnesota, in the north; Terrell and Potter cos., Texas, in the west; Alcorn Co., Mississippi, in the east; and southwestern Tamaulipas, Mexico, in the south. Occurrences are projected for southeastern South Dakota, northwestern Alabama, and the southwestern periphery of Tennessee. The type series of A. texense consists solely of the male holotype, so a neotype will be needed if this individual is ever lost, because no paratypes were officially designated
Data Mining Approach for Target Marketing SMEs in Nigeria
Presently, in addition to the lack of funds experienced by SMEs in
Nigeria, the main challenges experienced by SMEs (Small and Medium
Enterprises) in Nigeria has to do with them not being able to understand and
the apply marketing concept. Also there are a lot of resources being wasted in
marketing campaign which does not target anybody in particular. This study is
therefore focused on finding the target market of SMEs using the K-means
clustering technique in combination with sentiment analysis, also known as
opinion mining. The study also aims at recommending the best medium to
market these SMEs as discovered from the output of the analysis. The result of
this research will give positive direction to improving the profit of small and
medium business through target marketing. Also, this study is not trivial
because it will help to reduce marketing cost through target marketing. The
study also helps to discover the opinion of the populace on the small and
medium business and the medium through which they can be targeted. This
discovery will definitely form solid foundation for further marketing action and
improve their profit
Novel low-loss bandgaps in all-silica Bragg fibers
Copyright © 2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.We demonstrate that higher order bandgaps in all-silica Bragg fibers can have modes with four orders of magnitude lower confinement loss than those using the fundamental bandgap. A scheme for exploiting the higher order gaps for any specific wavelength via a global scaling of the fiber geometry is proposed. This approach provides lower losses than by reducing the confinement loss of the fundamental gap by scaling the core. Using a variety of modeling techniques, we have examined the band structure and guidance of idealized air-core all-silica Bragg fibers. It is demonstrated that the higher order, low loss, bandgaps analyzed here are uniquely accessible to single-material Bragg fibers, and are fundamentally different from the higher order gaps typically associated with depressed-index Bragg fibers such as the ldquoOmniguiderdquo fibers. Further analysis suggests that some of the key features of the guided modes of Bragg fibers can be understood by considering the properties of single hollow-core homogeneous dielectric waveguides (ldquoboreholesrdquo)
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