1,714 research outputs found

    Erroneous environs or aberrant activities? Reconciling unexpected collection localities for three New Guinea Worm-eating Snakes (Toxicocalamus, Serpentes, Elapidae) using historical account

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    Permission granted from editor to include publisher's pdf file.In contrast to birds and large mammals, which can usually be observed and recognized using binoculars and field guides, many reptile and amphibian species are secretive, rarely seen, and difficult to identify from a distance. The characters that separate closely related snakes or lizards often revolve around some finite details of the head or body scalation rather than highly visible color patterns, and these are essentially impossible to discern without close inspection; sometimes these characteristics are difficult to determine even up close, without magnification. Therefore, while many bird and mammal distribution maps may be compiled from non-invasive observations, often by armies of experienced amateurs, the ranges of many reptile species often depend on the locality data that should accompany museum specimens whose identity has been established. If such data are inaccurate or erroneous, it may then easily lead to misconceptions regarding the range and conservation status of a particular species – to use a computing term, garbage in, garbage out

    A complete sample of radio sources in the North Ecliptic Cap, selected at 38 MHz -- III. further imaging observations and the photometric properties of the sample

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    Further imaging observations of a sample of radio sources in the North Ecliptic Cap are presented and a number of new identifications are made. Using redshifts from spectroscopic data presented in a companion paper (Lacy et al.\ 1999b), the photometric properties of the galaxies in the sample are discussed. It is shown that: (1) out to at least z~0.6 radio galaxies are good standard candles irrespective of radio luminosity; (2) for 0.6~<z~<1 a large fraction of the sample have magnitudes and colours consistent with a non-evolving giant elliptical, and (3) at higher redshifts, where the R-band samples the rest-frame UV flux, most objects have less UV luminosity than expected if they form their stellar populations at a constant rate from a high redshift to z∌1z\sim 1 in unobscured star-forming regions (assuming an Einstein -- de Sitter cosmology). The consequences of these observations are briefly discussed.Comment: 10 pages, 6 figures, accepted by MNRA

    A portable, low-cost approach for photographing fluid preserved snake specimens- Recommendations with comments on optimizing specimen photography in Natural History collections

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    Access to preserved specimens in museum collections is one of the key needs of those engaged in systematics research (e.g., Bi et al. 2013; Rocha et al. 2014; McLean et al. 2016). Yet, sometimes the constraints of research budgets and time prevent the optimal use of this critical resource, resulting in project delays, incomplete information, or flawed scientific conclusions. With many natural history museums now digitizing information related to specimens in their collections, imaging of specimens is a logical next step, and one of critical importance to make holdings available electronically to a broader audience (Baird 2010; Lister et al. 2011; Knight-Davis et al. 2015; Page et al. 2015). A complete 2D image library of all specimens in a collection may appear utopian at the moment, given the millions of specimens and lack of financial support for collections (e.g., Paknia et al. 2015). However, outside of visiting each collection to study individual specimens, or requesting loans of unique and valuable specimens, the lack of suitable specimen images means that some data may simply remain unavailable to researchers who cannot afford to obtain them. We wish to emphasize that the approach we advocate herein in no way negates the need to maintain and make accessible physical specimens in a collection. Although in rare cases where the lack of specimens is unavoidable (e.g., Marshall and Evenhuis 2015; Pape et al. 2016), there is no replacement for examining a well-preserved specimen. Our method should be regarded as an ancillary technique, useful when it is necessary to obtain preliminary data or when it is not possible to examine the specimen in person, and for archival purposes

    Mortgage, Treasury, CD and Fed Funds Rates Spreads and Risk Premiums: How do They Impact Net Interest Margins?

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    This paper utilized FRED (Federal Reserve Economic Data) data from the Federal Reserve Bank of St. Louis to examine historical risk premiums between 30-year mortgages and 30-year T-Bonds and spreads between yields on these two assets and funding costs represented by 6-month CD rates and fed funds rates. Risk premiums were greatest and spreads were smallest (some-times negative) during the high interest rate environment during the late 1970’s and early 1980’s. Risk premiums got smaller after the two financial crises of the 2000’s (the September 11, 2001 attack and the 2008 mortgage crisis) and the spreads became larger after both when the Federal Reserve cut rates tremendously. Despite these variations in income/cost spreads, net interest margins (to both total assets and earning assets) remained relatively stable. Regression analysis shows the best predictor of historical net interest margins was the 30-year treasury yield in lagged and non-lagged models. These results suggest the ability of banks to choose fund sources and fund uses allows them to reduce variation in net interest margins even while interest rates are volatile

    The effect of product variety on purchase probability

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    Regarding the effect of product variety on purchase probability, there exist findings which demonstrate a positive effect of variety for small assortments and a negative effect of variety for large assortments. Despite these results, little evidence exists about the causal mechanism of this effect. We conduct a field study among German consumer electronics customers to investigate the previously proposed constructs of anticipated product utility, anticipated regret and evaluation costs. The results suggest that anticipated regret and evaluation costs play a powerful role in explaining the negative link between variety and purchase probability for high variety assortments. Anticipated product utility on the other hand serves to explain part of the positive causality for low variety assortments. The results obtained give rise to recommendations for the planning of assortment
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