10,208 research outputs found
U.S. States Lead the World in High Corporate Taxes
Compares U.S. states' combined federal and state corporate tax rates with those of other industrialized nations. Argues for cutting both federal and state taxes in order to compete for foreign direct investment against developed nations with lower rates
A statistical comparison of two carbon fiber/epoxy fabrication techniques
A statistical comparison of the compression strengths of specimens that were fabricated by either a platen press or an autoclave were performed on IM6/3501-6 carbon/epoxy composites of 16-ply (0,+45,90,-45)(sub S2) lay-up configuration. The samples were cured with the same parameters and processing materials. It was found that the autoclaved panels were thicker than the platen press cured samples. Two hundred samples of each type of cure process were compression tested. The autoclaved samples had an average strength of 450 MPa (65.5 ksi), while the press cured samples had an average strength of 370 MPa (54.0 ksi). A Weibull analysis of the data showed that there is only a 30 pct. probability that the two types of cure systems yield specimens that can be considered from the same family
An action research inquiry into what goes on in coaching supervision to the end of enhancing the coaching profession
This Project Report is an exploration of coaching supervision. Coaching supervision is now being advocated by most coaching associations in the UK as a vital means to support executive coaches in their continuing professional development. There is still considerable scepticism, caution, even ignorance about the nature and purpose of coaching supervision and many coaches still do not engage in this process or practice. The aim of this research project is to explore what actually goes on in the coaching supervision process and sessions over a period of time. Taking a Participatory Action Research approach, the researcher aimed to engage with two groups of fellow practitioners, one group of coaches and one group of coaching supervisors, to explore the respective supervision experiences of the participants. The duration of the project was 18 months. Over the period of the programme, the researcher conducted several Action Research cycles of inquiry that included the following activities (1) participants engaged in their regular coaching supervision (2) in turn they kept reflective logs of their learning and sense-making (3) each group came together to share their experiences in meetings based on Action Learning Set format (Revans 1971). The final report in the form of this Project Report provides a record of the Project, the researcher’s deepening of her own practice, the experience and learning of the participants and the themes that emerged. It offers a fresh perspective with the Three Pillars that inform coaching supervision and its efficacy to support executive coaches to keep them fit for purpose
An arbuscular mycorrhizal fungus accelerates decomposition and acquires nitrogen directly from organic material
Arbuscular mycorrhizal fungi (order Glomales), which form mycorrhizal symbioses with two out of three of all plant species, are believed to be obligate biotrophs that are wholly dependent on the plant partner for their carbon supply. It is thought that they possess no degradative capability and that they are unable to decompose complex organic molecules, the form in which most soil nutrients occur. Earlier suggestions that they could exist saprotrophically were based on observation of hyphal proliferation on organic materials. In contrast, other mycorrhizal types have been shown to acquire nitrogen directly from organic sources. Here we show that the arbuscular mycorrhizal symbiosis can both enhance decomposition of and increase nitrogen capture from complex organic material (grass leaves) in soil. Hyphal growth of the fungal partner was increased in the presence of the organic material, independently of the host plant
Arbuscular mycorrhizal fungi in organic systems
Arbuscular mycorrhizal fungi (AMF) are potential contributors to plant nutrition and pathogen suppression in low input agricultural systems, although individual species of AMF vary widely in their functional attributes. Recent studies at HRI and elsewhere have suggested that in some agricultural systems inoculum of AMF is substantially lower under conventional management relative to that under organic management. Further studies have suggested that conventional management selects AMF communities with limited benefits to their plant hosts relative to those in organic systems. There is a need to investigate the generality of these findings, and their implications for the productivity of organic systems, particularly during the period following conversion to organic management.
The current project was designed to pull together existing understanding of the role, and potential role, of AMF in organic systems, and to identify sites and develop methods for use in a subsequent research programme. The project had three objectives:
01 To deliver a literature review covering current knowledge of the role of AMF in conventional and organic agricultural systems.
The review considered the ways in which management influences the structure and functioning of AMF communities, including their contributions under conventional and organic management, and recommendations for future research needs.
02 To establish the extent of differences in AMF inoculum between organic and conventional systems, covering a range of management practices.
Paired organic and conventional fields at 12 sites from across England were selected to investigate the relationships between management, AMF communities and soil chemistry. Organic and conventionally managed soils showed no significant difference in soil chemical properties (Organic C, total N, total P, extractable P, K, Mg). However, organically managed soils had greater AMF spore numbers and root colonisation potential, and therefore higher AMF inoculum potential, than conventionally managed soil. The relative difference in AMF spore numbers between organic and conventionally managed fields increased with time since conversion. Differences in AMF inoculum potential between organic and conventionally managed fields, and between farm sites, could not be related to differences in soil chemistry.
03 To develop a method suitable for characterising AM fungus communities in soil libraries, based on 18S rRNA terminal restriction fragment length polymorphism (T-RFLP)
T-RFLP was shown to provide a rapid semi-quantitative method for analysis of AMF community diversity. However it was clear that primers currently used to amplify AMF are selective and do not allow diversity of the whole AMF community to be determined. Additionally these primers amplify contaminant fungi which need to be removed from the T-RFLP profile prior to analysis. However, contaminant diversity was shown to be low.
The project has identified sites and techniques which could be valuable in future research to study the role of AMF under organic management. The study has also highlighted a number of key areas in which further research is needed in order to harness AMF to improve sustainability and productivity of organic and other agricultural systems. In particular, there is a need to determine the extent to which AMF diversity varies between organic and conventional management, the rate and mechanisms by which AMF diversity increases following conversion to organic production, the relationships between AMF diversity and crop nutrition/ pathogen control, and the soil factors controlling the effectiveness of AMF inoculum
Spectral characteristics of earth-space paths at 2 and 30 FHz
Spectral characteristics of 2 and 30 GHz signals received from the Applications Technology Satellite-6 (ATS-6) are analyzed in detail at elevation angles ranging from 0 deg to 44 deg. The spectra of the received signals are characterized by slopes and break frequencies. Statistics of these parameters are presented as probability density functions. Dependence of the spectral characteristics on elevation angle is investigated. The 2 and 30 GHz spectral shapes are contrasted through the use of scatter diagrams. The results are compared with those predicted from turbulence theory. The average spectral slopes are in close agreement with theory, although the departure from the average value at any given elevation angle is quite large
Plant root proliferation in nitrogen-rich patches confers competitive advantage
Plants respond to environmental heterogeneity, particularly below ground, where spectacular root proliferations in nutrient-rich patches may occur. Such 'foraging' responses apparently maximize nutrient uptake and are now prominent in plant ecological theory. Proliferations in nitrogen-rich patches are difficult to explain adaptively, however. The high mobility of soil nitrate should limit the contribution of proliferation to N capture. Many experiments on isolated plants show only a weak relation between proliferation and N uptake. We show that N capture is associated strongly with proliferation during interspecific competition for finite, locally available, mixed N sources, precisely the conditions under which N becomes available to plants on generally infertile soils. This explains why N-induced root proliferation is an important resource-capture mechanism in N-limited plant communities and suggests that increasing proliferation by crop breeding or genetic manipulation will have a limited impact on N capture by well-fertilized monocultures
The Outer Edges of Dwarf Irregular Galaxies: Stars and Gas
We have in recent years come to view dwarf galaxy evolution in the broader
context of the cosmic evolution of large-scale structure. Dwarf galaxies, as
the putative building blocks of hierarchical galaxy formation, and also as the
most numerous galaxies in the Universe, play a central role in cosmic
evolution. In particular, the interplay of galactic and intergalactic material
around dwarf irregulars must be more extensive than in more massive disk
galaxies because of their lower gravitational potential and lower interstellar
pressures. The outer regions of dwarf irregular galaxies therefore yield vital
clues to the dominant processes in this interaction zone.
The Workshop addressed a number of questions related to the role of the outer
regions in the evolution of dwarf galaxies and broader consequences. On-line
Workshop Proceedings are at http://www.lowell.edu/Workshops/Lowell02/Comment: Summary of the 2002 Lowell Observatory Workshop, to appear in PASP
Conference Highlights; 6 pp, uses aaspp4.sty. On-line Proceedings at
http://www.lowell.edu/Workshops/Lowell02
Corrosion resistant thermal barrier coating
A thermal barrier coating system for protecting metal surfaces at high temperature in normally corrosive environments is described. The thermal barrier coating system includes a metal alloy bond coating, the alloy containing nickel, cobalt, iron, or a combination of these metals. The system further includes a corrosion resistant thermal barrier oxide coating containing at least one alkaline earth silicate. The preferred oxides are calcium silicate, barium silicate, magnesium silicate, or combinations of these silicates
Reframing the Opioid Epidemic as a National Emergency
On August 10, 2017 President Trump announced his intention to declare a national emergency following the recommendation of the White House Commission on Combating Drug Addiction and the Opioid Crisis. Opioid abuse is among the most consequential preventable public health threats facing the nation. More than 600,000 deaths have occurred to date, with 180,000 more predicted by 2020. Of the 20.5 million US residents 12 years or older with substance use disorders in 2015, 2 million were addicted to prescription pain relievers. A national emergency declaration authorizes public health powers, mobilizes resources, and facilitates innovative strategies to curb a rapidly escalating public health crisis
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