408 research outputs found
Numbers of fecal streptococci and Escherichia coli in fresh and dry cattle, horse, and sheep manure
Livestock are known contributors to stream pollution. Numbers of fecal streptococci and Escherichia coli in
manure naturally deposited by livestock in the field are needed for activities related to bacterial source tracking and determining
maximum daily bacterial loading of streams. We measured populations of fecal streptococci and E. coli in
fresh and dry manure from cattle (Bos taurus L.), horses (Equus caballus L.), and sheep (Ovis aires L.) on farms in
southern Idaho. Populations of indicator bacteria in dry manure were often as high as that in fresh manure from horse
and sheep. There was a 2 log 10 drop in the population of fecal coliform numbers in dry cattle manure from cattle in
pastures but not from cattle in pens. Bacterial isolates used in source tracking should include isolates from both fresh
and dry manure to better represent the bacterial source loading of streams
Sustainable Development: A Systems Approach
This Status Report summarizes the final report of the IIASA Environment and Development Study which was submitted to the Secretariat of the United Nations Conference on Environment and Development (UNCED) in December 1991. As a systems analysis institute, IIASA was asked by UNCED in mid-1990 to explore the usefulness of systems analysis in: identifying some of the important linkages among population, environment, and development; examining some of the underlying causes of environmentally unsustainable development; and in formulating and implementing policies for more sustainable development. The work first involved the formulation of conceptual models of the socio-ecological system in which we live. The application of systems analysis to environment and development was then examined in several case studies. The case studies, based mainly upon past and present work carried out here at IIASA, indicated that systems analysis is potentially very useful in helping us towards a sustainable future. However, the work that is described in the report gives only a few examples of what could be done in the years following UNCED
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Direct comparison of different experimental techniques for measuring neutron capture and fission cross sections for Pu
Implementing the Five-A Model of technical refinement: Key roles of the sport psychologist
There is increasing evidence for the significant contribution provided by sport psychologists within applied coaching environments. However, this rarely considers their skills/knowledge being applied when refining athletesâ already learned and well-established motor skills. Therefore, this paper focuses on how a sport psychologist might assist a coach and athlete to implement long-term permanent and pressure proof refinements. It highlights key contributions at each stage of the Five-A Modelâdesigned to deliver these important outcomesâproviding both psychomotor and psychosocial input to the support delivery. By employing these recommendations, sport psychologists can make multiple positive contributions to completion of this challenging task
Expression of insulin pathway genes during the period of caste determination in the honey bee, Apis mellifera
Female honeybees have two castes, queens and workers. Developmental fate is determined by larval diet. Coding sequences made available through the Honey Bee Genome Sequencing Consortium allow for a pathway-based approach to understanding caste determination. We examined the expression of several genes of the insulin signalling pathway, which is central to regulation of growth based on nutrition. We found one insulin-like peptide expressed at very high levels in queen but not worker larvae. Also, the gene for an insulin receptor was expressed at higher levels in queen larvae during the 2nd larval instar. These results demonstrate that the insulin pathway is a compelling candidate for pursing the relationship between diet and downstream signals involved in caste determination and differentiation
Evidence for phase formation in potassium intercalated 1,2;8,9-dibenzopentacene
We have prepared potassium intercalated 1,2;8,9-dibenzopentacene films under
vacuum conditions. The evolution of the electronic excitation spectra upon
potassium addition as measured using electron energy-loss spectroscopy clearly
indicate the formation of particular doped phases with compositions
Kdibenzopentacene ( = 1,2,3). Moreover, the stability of these phases as
a function of temperature has been explored. Finally, the electronic excitation
spectra also give insight into the electronic ground state of the potassium
doped 1,2;8,9-dibenzopentacene films.Comment: 6 pages, 5 figures. arXiv admin note: text overlap with
arXiv:1201.200
Green functions for generalized point interactions in 1D: A scattering approach
Recently, general point interactions in one dimension has been used to model
a large number of different phenomena in quantum mechanics. Such potentials,
however, requires some sort of regularization to lead to meaningful results.
The usual ways to do so rely on technicalities which may hide important
physical aspects of the problem. In this work we present a new method to
calculate the exact Green functions for general point interactions in 1D. Our
approach differs from previous ones because it is based only on physical
quantities, namely, the scattering coefficients, and , to construct .
Renormalization or particular mathematical prescriptions are not invoked. The
simple formulation of the method makes it easy to extend to more general
contexts, such as for lattices of general point interactions; on a line; on
a half-line; under periodic boundary conditions; and confined in a box.Comment: Revtex, 9 pages, 3 EPS figures. To be published in PR
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