12,007 research outputs found
Hunting and sale of Pangolins across Sub-Saharan Africa: a preliminary analysis
Pangolins (Pholidota: Manidae) are hunted and traded for their meat and scales. We conducted preliminary analyses on the hunting and sale at markets of four species of pangolin across Sub-Saharan Africa based on data from the OFFTAKE database. Our analyses show that all four species of African pangolin are hunted and sold at markets throughout much of Sub-Saharan Africa. The proportion of pangolins as part of the total vertebrates hunted has increased significantly during the 43 years, from 1972-2014, for which we have data
An Infill Station in Atlanta: Evaluating a MARTA rail stop at Hulsey Yard
Across America a handful of cities have begun experimenting with an uncommon method for fostering new ridership and economic development adjacent to their heavy rail routes. Infill stations provide municipalities the chance to adapt their public transit infrastructure to a changing urban landscape in addition to increasing their tax base. The Metropolitan Atlanta Rapid Transit Authority (MARTA) commissioned an infill station study in 2007 but is yet to act on any significant recommendations. Since the study, Atlanta’s BeltLine has grown tremendously both in physical size as well as its popularity and influence. The BeltLine’s Eastside Trail crosses MARTA at Hulsey Yard, one of many potential infill station locations. Using the case study of what is perhaps the most well-known infill station, D.C.’s NoMa-Gaullaudet U station, this paper attempts to determine the potential for an infill station along MARTA’s eastern line at Hulsey Yard while considering political and fiscal realities regarding the state of Georgia and MARTA. This paper finds Hulsey Yard to be a sufficient location for an infill station, now more so than ever before, but also acknowledges the severe limitations MARTA faces in terms of transit-friendly resources.Welch, Timothy F
Molecular basis for resistance of acanthamoeba tubulins to all major classes of antitubulin compounds
Tubulin is essential to eukaryotic cells and is targeted by several antineoplastics, herbicides, and antimicrobials. We demonstrate that Acanthamoeba spp. are resistant to five antimicrotubule compounds, unlike any other eukaryote studied so far. Resistance correlates with critical amino acid differences within the inhibitor binding sites of the tubulin heterodimers
Induced encystment improves resistance to preservation and storage of Acanthamoeba castellanii
Several conditions that allow the preservation, storage and rapid, efficient recovery of viable Acanthamoeba castellanii organisms were investigated. The viability of trophozoites (as determined by time to confluence) significantly declined over a period of 12 months when stored at −70°C using dimethyl sulfoxide (DMSO; 5 or 10%) as cryopreservant. As A. castellanii are naturally capable of encystment, studies were undertaken to determine whether induced encystment might improve the viability of organisms under a number of storage conditions. A. castellanii cysts stored in the presence of Mg2+ at 4°C remained viable over the study period, although time to confluence was increased from approximately 8 days to approximately 24 days over the 12-month period. Storage of cysts at −70°C with DMSO (5 or 10%) or 40% glycerol, but not 80% glycerol as cryopreservants increased their viability over the 12-month study period compared with those stored at room temperature. Continued presence of Mg2+ in medium during storage had no adverse effects and generally improved recovery of viable organisms. The present study demonstrates that A. castellanii can be stored as a non-multiplicative form inexpensively, without a need for cryopreservation, for at least 12 months, but viability is increased by storage at −70°C
Reversal of the Lyapunov, Hölder, and Minkowski inequalities and other extensions of the Kantorovich inequality
Concerning periodic points in mappings of continua
In this paper we present some conditions which are sufficient for a mapping to have periodic points. © 1988 American Mathematical Society
Hands-on Gravitational Wave Astronomy: Extracting astrophysical information from simulated signals
In this paper we introduce a hands-on activity in which introductory
astronomy students act as gravitational wave astronomers by extracting
information from simulated gravitational wave signals. The process mimics the
way true gravitational wave analysis will be handled by using plots of a pure
gravitational wave signal. The students directly measure the properties of the
simulated signal, and use these measurements to evaluate standard formulae for
astrophysical source parameters. An exercise based on the discussion in this
paper has been written and made publicly available online for use in
introductory laboratory courses.Comment: 5 pages, 4 figures; submitted to Am. J. Phy
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