3,747 research outputs found

    Asymptotics for rank and crank moments

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    Moments of the partition rank and crank statistics have been studied for their connections to combinatorial objects such as Durfee symbols, as well as for their connections to harmonic Maass forms. This paper proves a conjecture due to Bringmann and Mahlburg that refined a conjecture of Garvan. Garvan's conjecture states that the moments of the crank function are always larger than the moments of the rank function, even though the moments have the same main asymptotic term. The proof uses the Hardy-Ramanujan method to provide precise asymptotic estimates for rank and crank moments and their differences.Comment: 11 page

    Sticky physics of joy: On the dissolution of spherical candies

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    Assuming a constant mass-decrease per unit-surface and -time we provide a very simplistic model for the dissolution process of spherical candies. The aim is to investigate the quantitative behavior of the dissolution process throughout the act of eating the candy. In our model we do not take any microscopic mechanism of the dissolution process into account, but rather provide an estimate which is based on easy-to-follow calculations. Having obtained a description based on this calculation, we confirm the assumed behavior by providing experimental data of the dissolution process. Besides a deviation from our prediction caused by the production process of the candies below a diameter of 2 mm, we find good agreement with our model-based expectations. Serious questions on the optimal strategy of enjoying a candy will be addressed, like whether it is wise to split the candy by breaking it with the teeth or not

    Genetic analysis of the human tumor necrosis factor alpha/cachectin promoter region in a macrophage cell line.

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    The 615-bp 5' flanking region of the human TNF-alpha/cachectin gene was isolated and ligated to the luciferase reporter gene. In addition, a series of truncated promoter constructs was generated by exonuclease III digestion. The promoter activity of these constructs was studied in a transient transfection system using the TNF-alpha-producing U937 cell line. Full-length and truncated TNF promoter constructions extending from -615 to -95 bp relative to the transcription start site (TSS) could be induced by phorbol esters. A construct truncated to within 36 bp of the TSS (and within 11 bp of the TATAA box) was inactive. Therefore, the phorbol ester responsive is localized in the TNF/cachectin promoter to a relatively short region proximal to the TATAA box

    The native bee fauna of the Palouse Prairie (Hymenoptera: Apoidea)

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    While synoptic collections provide data on the range and general composition of the North American bee fauna, bee communities associated with specific habitats are largely uncharacterized.  This report describes the community of native bees currently found in remnant fragments of the Palouse Prairie of northern Idaho and southeastern Washington State.  Native bees were collected using standardized collection techniques including blue vane traps, colored pan traps and aerial netting.  More than 13,000 individuals were collected, representing at least 174 species and 36 morphospecies in 29 genera.  These data provide the most thorough characterization of the bee fauna of this vulnerable ecosystem, as well as community level information on bee species of unknown conservation status.  These results are relevant to regional conservation efforts and, more broadly, are representative of conditions in fragmented grasslands surrounded by intense agriculture, a common global land use pattern of conservation concern

    Spherophorus Necrophorus: Infection in Mink

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    Sporadic outbreaks, of Spherophorus necrophorus infection in mink are quite commonly observed. One animal, several animals, or a large portion of a herd may be affected. A typical outbreak of this disease is that observed by Dr. J. A. Hunt, Winthrop, Iowa, in a group of mink from which specimens were submitted to the Iowa Veterinary Diagnostic Laboratory

    Mixing Optimization in Grooved Serpentine Microchannels

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    © 2020 by the authors. Licensee MDPI, Basel, Switzerland. Computational fluid dynamics modeling at Reynolds numbers ranging from 10 to 100 was used to characterize the performance of a new type of micromixer employing a serpentine channel with a grooved surface. The new topology exploits the overlap between the typical Dean flows present in curved channels due to the centrifugal forces experienced by the fluids, and the helical flows induced by slanted groove-ridge patterns with respect to the direction of the flow. The resulting flows are complex, with multiple vortices and saddle points, leading to enhanced mixing across the section of the channel. The optimization of the mixers with respect to the inner radius of curvature (Rin) of the serpentine channel identifies the designs in which the mixing index quality is both high (M \u3e 0.95) and independent of the Reynolds number across all the values investigated

    Expanding the parameters of academia

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    This paper draws on qualitative data gathered from two studies funded by the UK Leadership Foundation for Higher Education to examine the expansion of academic identities in higher education. It builds on Whitchurch’s earlier work, which focused primarily on professional staff, to suggest that the emergence of broadly based projects such as widening participation, learning support and community partnership is also impacting on academic identities. Thus, academic as well as professional staff are increasingly likely to work in multi-professional teams across a variety of constituencies, as well as with external partners, and the binary distinction between ‘academic’ and ‘non-academic’ roles and activities is no longer clear-cut. Moreover, there is evidence from the studies of an intentionality about deviations from mainstream academic career routes among respondents who could have gone either way. Consideration is therefore given to factors that influence individuals to work in more project-oriented areas, as well as to variables that affect ways in which these roles and identities develop. Finally, three models of academically oriented project activity are identified, and the implications of an expansion of academic identities are reviewed
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