2,590 research outputs found
Characterization of Esterases and Glutathione S-Transferases in a Solitary Bee, \u3cem\u3eMegachile rotundata\u3c/em\u3e (Fab.): Variability, Developmental Multiplicity, Substrate Specificity, and Inhibition
The esterases and glutathione S-transferases of a solitary bee, Meqachile rotundata (Fab.) (Hymenoptera: Megachilidae), the alfalfa leafcutting bee, were characterized by electrophoresis, substrate specificity, and inhibition studies. Comparisons were made between ages, sexes, and life stages for several classes of substrates and their isomers: aromatic, aliphatic, and thio-esters. Two esterases were found to be allozymes and variable between individuals and sexes. Adults typically possess an esterase that hydrolyzes fluorescent substrates, an organophosphate insensitive esterase, and a series of type \u27B\u27 esterases that are very sensitive to organophosphate inhibition. Electrophoretic patterns are different between adults and immatures and are probably related to differences in niche. Differences in substrate specificities, electrophoretic forms, and activities between the sexes is likely a function of reproduction and the fact that females are solely responsible for nest construction. Esterases not only function in detoxication but may have a raison d\u27etre in various aspects of nest, cell, and cocoon construction. Both esterase and glutathione S-transferase activity decrease with age, but decreases in male activity are significantly greater than in females. Km and Vmax were determined for p-nitrophenylacetate using a mixture of female esterases, and the inhibition constants and mechanisms were determined for four organophosphorus compounds. Their toxicities, ranging from greatest to least, were naled \u3e paraoxon \u3e trichlorfon \u3e oxydemeton methyl. Glutathione S-transferase activity was also assayed over a range of natural product inhibitors (chalcones, flavones) and an herbicide (tridiphane). The alfalfa leafcutting bee is a better detoxifier than the honey bee, but how it, or any other pollinator, fits into plant allelochemic - insect herbivore theory is unclear
CREATING DOMESTIC DEPENDENTS: INDIAN REMOVAL, CHEROKEE SOVEREIGNTY AND WOMENâS RIGHTS
What, this project asks, are the impacts of the alliance between women and Native Americans in the nineteenth century debate over Indian Removal? How might groups similarly excluded from patriarchal systems of government by race and gender turn exclusion into arguments for inclusion? In what ways might this alliance change interpretations of the womenâs right and Native American rights movements? While arguments made by women and Native Americans during Indian Removal receive considerable scholarly attention, most studies-especially those concerned with womenâs involvement- subordinate Indian Removal to abolition or create significant omissions in the narratives of both movements by adopting a critical approach that interprets strategic use of racialized and gendered ideology as assimilation.
In â Creating Domestic Dependentsâ I fill these gaps and situate Indian Removal as a significant intersection of the Native American rights and womenâs rights movements. Using historical romances by Catherine Sedgwick and Lydia Child, Catherine Beecherâs âCircular Addressed to the Benevolent Ladies of the United States,â the Cherokee Nationâs â1829 Memorialâ and âLetter to the American People,â and domestic fiction by E.D.E.N Southworth and Nathaniel Hawthorne, I argue that, during Indian Removal, white women and the Cherokee come together to fight for rights by situating property-- the very thing used to exclude them-- at the center of their arguments for rights and against Indian Removal. In doing this, they create interdependent approaches that simultaneously embrace and reject prescribed societal roles in order to construct a rhetorical strategy composed of moments of public solidarity and strategic distance
Family memories in the home: contrasting physical and digital mementos
We carried out fieldwork to characterise and compare physical and digital mementos in the home. Physical mementos are highly valued, heterogeneous and support different types of recollection. Contrary to expectations, we found physical mementos are not purely representational, and can involve appropriating common objects and more idiosyncratic forms. In contrast, digital mementos were initially perceived as less valuable, although participants later reconsidered this. Digital mementos were somewhat limited in function and expression, largely involving representational photos and videos, and infrequently accessed. We explain these digital limitations and conclude with design guidelines for digital mementos, including better techniques for accessing and integrating these into everyday life, allowing them to acquire the symbolic associations and lasting value that characterise their physical counterparts
STRATA-VARIOUS: A flexible Fortran program for dynamic forward modeling of stratigraphy
STRATA-VARIOUS version 1.3 is a computer program written in Fortran 77 to perform two-dimensional forward modeling of stratigraphic processes. We designed specific features of the program to investigate orbital forcing of high-frequency glacioeustasy. This requires forward modeling of many hundreds of sea-level stillstands and the graphic display of relatively precise spatial details. To use this program, the user constructs files that specify the times and elevations of sea-level stillstands, the initial basement topography, numerous parameters that control the geometry and physical properties of stratigraphic beds, the isostatic response of the lithosphere, the pattern of tectonic subsidence and uplift, the number and scale of desired output cross sections, etc. Two features of this program are especially novel. Whereas many forward-modeling programs store information about stratigraphic beds in fixed-size horizontal bins, our program retains in memory the precise locations of all horizontal locations where any stratigraphic bed undergoes any distinct change. This allows us to obtain regional cross sections and magnified sections that preserve information about the geometry and lithology of individual beds. Second, for clastic sediments we have developed a realistic parametric scheme for describing how sea-level variation affects the sediment discharge rate. The parameters that control this scheme have simple physical interpretations in terms of the dimensions, erosion rates, etc. for the alluvial valley responsible for the sediment supply. In this article we give various examples of STRATA-VARIOUS graphic output to illustrate model sensitivity and to demonstrate some of the options available
STRATA-VARIOUS: A flexible Fortran program for dynamic forward modeling of stratigraphy
STRATA-VARIOUS version 1.3 is a computer program written in Fortran 77 to perform two-dimensional forward modeling of stratigraphic processes. We designed specific features of the program to investigate orbital forcing of high-frequency glacioeustasy. This requires forward modeling of many hundreds of sea-level stillstands and the graphic display of relatively precise spatial details. To use this program, the user constructs files that specify the times and elevations of sea-level stillstands, the initial basement topography, numerous parameters that control the geometry and physical properties of stratigraphic beds, the isostatic response of the lithosphere, the pattern of tectonic subsidence and uplift, the number and scale of desired output cross sections, etc. Two features of this program are especially novel. Whereas many forward-modeling programs store information about stratigraphic beds in fixed-size horizontal bins, our program retains in memory the precise locations of all horizontal locations where any stratigraphic bed undergoes any distinct change. This allows us to obtain regional cross sections and magnified sections that preserve information about the geometry and lithology of individual beds. Second, for clastic sediments we have developed a realistic parametric scheme for describing how sea-level variation affects the sediment discharge rate. The parameters that control this scheme have simple physical interpretations in terms of the dimensions, erosion rates, etc. for the alluvial valley responsible for the sediment supply. In this article we give various examples of STRATA-VARIOUS graphic output to illustrate model sensitivity and to demonstrate some of the options available
Cost reduction in bio-diesel production.
End of Project ReportAs part of a programme to assess bio-diesel production from low-cost
materials, the availability of waste oils and fats in Ireland and the EU
was assessed, and the behaviour of their esters in vehicles was
measured. The utilisation of beef tallow from BSE risk organisms
was given special attention.
Esterification of high-FFA tallow required the use of excess methanol
and base catalyst. Acidification, followed by glycerol separation and
secondary acid-catalysed esterification, brought ester yields up to
acceptable levels. The high melting point of the ester restricted its
use in vehicles to low proportions in mixes with mineral diesel.
Fuels made up from low-cost esters behaved well in vehicle trials,
even where there was a high level of dilution of the engine oil. The
only problems arose from inadequate low-temperature properties and
from suspended solids in the tallow ester.
Within the EU, there are sufficient waste oils and fats available to
greatly increase bio-diesel production. In Ireland, there is sufficient
for a small production unit
Holidaying with the family pet: No dogs allowed!
This paper assesses the extent to which dog owners located in Brisbane, Australia, wish to holiday with their pets, and whether there is a gap between this desire and reality. The paper also examines the extent to which this demand is being catered for by the tourism accommodation sector. The need for this study reflects the increasingly significant role dogs are playing in the lives of humans, and the scale
of the dog-owning population. The results suggest that, although there is a strong desire among dog owners to take holidays with their pets, the actualisation of this
desire is comparatively low. A significant obstacle to the realisation of this desire appears to be a dearth of pet-friendly accommodation. This has implications for the
ability of the tourism industry to benefit from this potentially lucrative market, that is, the dog-owning population
The Logarithmic Triviality of Compact QED Coupled to a Four Fermi Interaction
This is the completion of an exploratory study of Compact lattice Quantum
Electrodynamics with a weak four-fermi interaction and four species of massless
fermions. In this formulation of Quantum Electrodynamics massless fermions can
be simulated directly and Finite Size Scaling analyses can be performed at the
theory's chiral symmetry breaking critical point. High statistics simulations
on lattices ranging from to yield the equation of state, critical
indices, scaling functions and cumulants. The measurements are well fit with
the orthodox hypothesis that the theory is logarithmically trivial and its
continuum limit suffers from Landau's zero charge problem.Comment: 27 pages, 15 figues and 10 table
Coherent phenomena in mesoscopic systems
A mesoscopic system of cylindrical geometry made of a metal or a
semiconductor is shown to exhibit features of a quantum coherent state. It is
shown that magnetostatic interaction can play an important role in mesoscopic
systems leading to an ordered ground state. The temperature below the
system exhibits long-range order is determined. The self-consistent mean field
approximation of the magnetostatic interaction is performed giving the
effective Hamiltonian from which the self-sustaining currents can be obtained.
The relation of quantum coherent state in mesoscopic cylinders to other
coherent systems like superconductors is discussed.Comment: REVTeX, 4 figures, in print in Supercond. Sci. Techno
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