17,888 research outputs found
The Indo-Australian weevil genus Platytenes Pascoe, 1870 (Coleoptera: Curculionidae: Cryptorhynchinae)
The formerly monotypic weevil genus Platytenes Pascoe (Coleoptera: Curculionidae: Cryptorhynchinae: Cryptorhynchini: Cryptorhynchina) as treated here, includes two commonly encountered and broadly distributed species in the eastern Indo-Australian region. Label data indicate that both species are associated with semicultivated betel palm (Areca catechu L., Arecaceae) and human mediated dispersal is suggested to have influenced their present-day distribution. Herein, we provide a diagnosis for Platytenes and redescribe its type species, P. varius Pascoe. We also describe P. occultus Setliff and Larson, a new species from the Solomon Islands. New host and locality records are provided, including the first records of the genus occurring on Ambon Island, the Bismarck Archipelago, DâEntrecasteaux Islands, and many previously unreported localities on New Guinea. A full bibliography, key to species, and distribution map for the genus are also provided
How can the concepts of habitus and field help us to understand the engagement of educational workers in higher Education?
In âMaking a European area of lifelong learning a realityâ, the EU stressed the role of universities in relation to lifelong learning, a role that entails a need for widening access to universities, particularly for those not coming through the traditional direct route of upper secondary education. As teachers play a significant role in the quality of the lifelong learning as well as in motivating future generations to take part in lifelong learning, education and training for teachers becomes important; not only in relation to initial teacher education, but also in relation to a continuous development of knowledge and skills.
This paper represents the first stage of a larger comparative project intended to examine and compare educational workersâ (i.e. professionals involved in teaching in the class room) participation in higher education in England and Denmark, their access and interest. In particular, the paper relates participation and engagement to national and international educational policies and frames this work within an examination of the social background of the professional groups. The key research questions at this stage of the work are methodological and can be summed up by the overarching question, âHow can the concepts of habitus and field help us to understand levels of engagement of educational workers in Higher Educationâ?
The paper reports the results of our review of current policies and our efforts to identify the structural relations within the educational professional fields in each country. To do so we are developing a theoretical model using the relational analytical approach advocated by Bourdieu. As such, our work is an early stage attempt at operationalising Bourdieuâs observations regarding the dynamics of field. This seems to us to provide an important conceptual approach to understanding the habitus of educational workers in the context of the dynamics of a fast changing policy arena and the complexities of the backgrounds of individuals working in the educational field. The model attempts to build in the reflexivity that Bourdieu demands for a âscienceâ that is not weakened by over-emphasis on either the objective structural relations or the subjective phenomenology of experience.
Thus, the paper presents a preliminary contextual analysis of the factors that enable an understanding of engagement or lack of engagement in higher level learning among school-based education workers in the two EU countries and is related to a larger research project that explores habitus (both individual and collective) among these groups of education workers
Transmission electron microscopy characterization of microstructural features of Al-Li-Cu alloys
A transmission electron microscopy (TEM) examination of aluminum-lithium-copper alloys was conducted. The principal purpose is to characterize the nature, size, and distribution of stringer particles which result from the powder metallurgy (P/M) processing of these alloys. Microstructural features associated with the stringer particles are reported that help explain the stress corrosion susceptibility of the powder metallurgy-processed Al-Li-Cu alloys. In addition, matrix precipitation events are documented for a variety of heat treatments and process variations. Hot rolling is observed to significant alter the nature of matrix precipitation, and the observations are correlated with concomitant mechanical property variations
COTTON CULTIVAR, PLANTING, IRRIGATING, AND HARVESTING DECISIONS UNDER RISK
Producers in southwest Oklahoma lack adequate information about optimal planting decisions for cotton. This study uses a cotton growth simulation model to evaluate alternative cultivar, planting date, irrigation, and harvest choices. Effects of using information about soil moisture at reproduction and revenue loss at harvest in making cultivar and planting data decisions are evaluated. Using soil temperature information to plant at an early date produced high net revenue some years, but reduced mean net revenue and increased risk. Producers maximizing expected net revenue should plant a short-season cultivar in late May and use soil moisture information to schedule irrigation at reproduction.Crop Production/Industries,
Numerical studies of a one-dimensional 3-spin spin-glass model with long-range interactions
We study a p-spin spin-glass model to understand if the finite-temperature
glass transition found in the mean-field regime of p-spin models, and used to
model the behavior of structural glasses, persists in the non-mean-field
regime. By using a 3-spin spin-glass model with long-range power-law diluted
interactions we are able to continuously tune the (effective) space dimension
via the exponent of the interactions. Monte Carlo simulations of the spin-glass
susceptibility and the two-point finite-size correlation length show that deep
in the non-mean-field regime the finite-temperature transition is lost, whereas
this is not the case in the mean-field regime, in agreement with the prediction
of Moore and Drossel [Phys. Rev. Lett. 89, 217202 (2002)] that 3-spin models
are in the same universality class as an Ising spin glass in a magnetic field.
However, slightly in the non-mean-field region, we find an apparent transition
in the 3-spin model, in contrast to results for the Ising spin glass in a
field. This may indicate that even larger sizes are needed to probe the
asymptotic behavior in this region.Comment: 8 pages, 9 figures, 1 tabl
MODELING FARM AND OFF-FARM ECONOMIC LINKAGES TO ANALYZE THE IMPACTS OF AN AREA-WIDE INSECT MANAGEMENT PROGRAM ON A REGIONAL ECONOMY
This study evaluated the impacts of the boll weevil eradication program at the farm level and on the west Tennessee region. Budgets, an acreage response model, and an input-output model were used to evaluate direct and indirect program impacts. The program generates small but positive economic benefits for the region.Crop Production/Industries,
Backflushing system rapidly cleans fluid filters
Self contained unit can backflush filter elements in fraction of the time expended by presently used equipment. This innovation may be of interest to manufacturers of hydraulic and pneumatic systems as well as to chemical, food, processing, and filter manufacturing industries
Dark cloud cores and gravitational decoupling from turbulent flows
We test the hypothesis that the starless cores may be gravitationally bound
clouds supported largely by thermal pressure by comparing observed molecular
line spectra to theoretical spectra produced by a simulation that includes
hydrodynamics, radiative cooling, variable molecular abundance, and radiative
transfer in a simple one-dimensional model. The results suggest that the
starless cores can be divided into two categories: stable starless cores that
are in approximate equilibrium and will not evolve to form protostars, and
unstable pre-stellar cores that are proceeding toward gravitational collapse
and the formation of protostars. The starless cores might be formed from the
interstellar medium as objects at the lower end of the inertial cascade of
interstellar turbulence. Additionally, we identify a thermal instability in the
starless cores. Under par ticular conditions of density and mass, a core may be
unstable to expansion if the density is just above the critical density for the
collisional coupling of the gas and dust so that as the core expands the
gas-dust coupling that cools the gas is reduced and the gas warms, further
driving the expansion.Comment: Submitted to Ap
A Survey for Spectroscopic Binaries Among Very Low-Mass Stars
We report on the results of a survey for radial velocity variability in a
heterogeneous sample of very low-mass stars and brown dwarfs. One
distinguishing characteristic of the survey is its timespan, which allows an
overlap between spectroscopic binaries and those which can be found by high
angular-resolution imaging. We are able to place a new constraint on the total
binary fraction in these objects, which suggests that they are more likely the
result of extending the same processes at work at higher masses into this mass
range, rather than a distinct mode of formation. Our basic result is that there
are out of 53, or % spectroscopic binaries in the
separation range 0-6 AU, nearly as many as resolved binaries. This leads to an
estimate of an upper limit of % for the binary fraction of VLM
objects (it is an upper limit because of the possible overlap between the
spectroscopic and resolved populations). A reasonable estimate for the very
low-mass binary fraction is %. We consider several possible separation
and frequency distributions, including the same one as found for GK stars, a
compressed version of that, a version of the compressed distribution truncated
at 15 AU, and a theoretical distribution which considers the evaporation of
small-N clusters. We conclude that the latter two bracket the observations,
which may mean that these systems form with intrinsically smaller separations
due to their smaller mass, and then are truncated due to their smaller binding
energy. We do not find support for the ``ejection hypothesis'' as their
dominant mode of formation, particularly in view of the similarity in the total
binary fraction compared with slightly more massive stars, and the difficulty
this mechanism has in producing numerous binary systems.Comment: 36 pages, accepted for publication in AJ, abstract shortened for
arXiv.or
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