888 research outputs found
Effect of Salinity and Waterlogging on Growth and Survival of Salicornia europaea L., and Inland Halophyte
Author Institution: Department of Environmental and Plant Biology, Ohio UniversitySalicornia europaea seedlings were exposed to various salinity and water depths for 11 weeks under controlled, growth chamber conditions. Weekly measurements were made of height, number of nodes, and number of branches per plant. Growth and survival of plants grown with the addition of NaCl were significantly greater (P 0.05) growth differences among plants under different water level conditions within the salt treatment group, plants which were grown without NaCl demonstrated significant decreases in growth in higher water levels, with the greatest growth occurring in the low water treatment group. All plants given a salt treatment survived until the end of the experiment. However, high mortality occurred among the plants that were not salt-treated, with all plants grown under waterlogged conditions dying by week six. The high mortality exhibited by this treatment group indicates that Salicornia, which is typically found in low marsh or inland salt marsh situations, was unable to overcome the combined stress of being continuously waterlogged in a freshwater environment
ADVISORY SERVICE MARKETING PROFILES FOR CORN OVER 1995-2000
This report presents marketing profiles and loan deficiency payment/marketing loan gain profiles for the advisory services followed by the AgMAS Project for the 1995 through 2000 corn crops. Marketing profiles are constructed by plotting the cumulative net amount priced under each program's set of recommendations throughout a crop year. Loan deficiency payment/marketing loan gain (LDP/MLG) profiles are constructed by plotting the cumulative percentage of the crop on which the LDP/MLG was claimed during the crop year. Marketing profiles provide information to evaluate the style of advisory services in several ways. The percentage of crop priced is a measure of within-crop year price risk. The higher the proportion of a crop priced, the lower the sensitivity of the farmer's position value to crop price changes. For example, when 100% of the crop is priced there is no price sensitivity, which means that changes in price do not affect the value of the farmer's position. On the other hand, when the amount priced is 0%, the value of the farmer's position will vary in the same proportion as the change in price. Marketing profiles, therefore, allow investigating the evolution of price sensitivity under each service's set of recommendations along the marketing window. Marketing profiles also provide other useful information. The number of steps in the profile lines and the location of these steps in the marketing window provide information about timing, frequency and size of recommended transactions. It is also possible to determine from the marketing profile figures how intensely a program uses options markets, since when options positions are open the profile line is irregular. In the same way, LDP/MLG profiles provide information about the size and timing of LDP/MLG claims.Marketing,
ADVISORY SERVICE MARKETING PROFILES FOR SOYBEANS OVER 1995-2000
This report presents marketing profiles and loan deficiency payment/marketing loan gain profiles for the advisory services followed by the AgMAS Project for the 1995 through 2000 soybean crops. Marketing profiles are constructed by plotting the cumulative net amount priced under each program's set of recommendations throughout a crop year. Loan deficiency payment/marketing loan gain (LDP/MLG) profiles are constructed by plotting the cumulative percentage of the crop on which the LDP/MLG was claimed during the crop year. Marketing profiles provide information to evaluate the style of advisory services in several ways. The percentage of crop priced is a measure of within-crop year price risk. The higher the proportion of a crop priced, the lower the sensitivity of the farmer's position value to crop price changes. For example, when 100% of the crop is priced there is no price sensitivity, which means that changes in price do not affect the value of the farmer's position. On the other hand, when the amount priced is 0%, the value of the farmer's position will vary in the same proportion as the change in price. Marketing profiles, therefore, allow investigating the evolution of price sensitivity under each service's set of recommendations along the marketing window. Marketing profiles also provide other useful information. The number of steps in the profile lines and the location of these steps in the marketing window provide information about timing, frequency and size of recommended transactions. It is also possible to determine from the marketing profile figures how intensely a program uses options markets, since when options positions are open the profile line is irregular. In the same way, LDP/MLG profiles provide information about the size and timing of LDP/MLG claims.Marketing,
A discourse analysis of trainee teacher identity in online discussion forums
Teacher education involves an identity transformation for trainees from being a student to being a teacher. This discourse analysis examined the online discussion board communications of a cohort of trainee teachers to better understand the situated identities of the trainees and how they were presented online. Their discussion board posts were the primary method of communication during placement periods and, as such, provided insight into how the trainees situated their identities in terms of being a student or being a teacher. During the analysis, the community boundaries, language and culture were explored along with the tutor's power and role in the identity transformation process. This involved looking at the lexis used by the students, the use of pronouns to refer to themselves and others such as teachers and pupils, the types of messages allowed in the community and the effect of the tutor's messages on their communication. The research found that the trainees felt comfortable with teaching but did not feel like teachers during the course. Tutors and school teachers need to develop an awareness of the dual nature of trainees' identities and help promote the transition from student to teacher. In the beginning of the course, trainees should be familiarised with teacher vocabulary and practical concepts in addition to pedagogical theory. Towards the end of the course, trainee identity as teachers could be promoted through the use of authentic assessments that mirror real teacher tasks and requirements
Are Newly Discovered HI High Velocity Clouds Minihalos in the Local Group?
A set of HI sources extracted from the north Galactic polar region by the
ongoing ALFALFA survey has properties that are consistent with the
interpretation that they are associated with isolated minihalos in the
outskirts of the Local Group (LG). Unlike objects detected by previous surveys,
such as the Compact High Velocity Clouds of Braun & Burton (1999), the HI
clouds found by ALFALFA do not violate any structural requirements or halo
scaling laws of the LambdaCDM structure paradigm, nor would they have been
detected by extant HI surveys of nearby galaxy groups other than the LG. At a
distance of d Mpc, their HI masses range between $5 x 10^4 d^2 and 10^6 d^2
solar and their HI radii between <0.4d and 1.6 d kpc. If they are parts of
gravitationally bound halos, the total masses would be on order of 10^8--10^9
solar, their baryonic content would be signifcantly smaller than the cosmic
fraction of 0.16 and present in a ionized gas phase of mass well exceeding that
of the neutral phase. This study does not however prove that the minihalo
interpretation is unique. Among possible alternatives would be that the clouds
are shreds of the Leading Arm of the Magellanic Stream.Comment: 4 pages, 3 figures, 1 table; to appear Ap.J. Letter
Accretion of Planetary Material onto Host Stars
Accretion of planetary material onto host stars may occur throughout a star's
life. Especially prone to accretion, extrasolar planets in short-period orbits,
while relatively rare, constitute a significant fraction of the known
population, and these planets are subject to dynamical and atmospheric
influences that can drive significant mass loss. Theoretical models frame
expectations regarding the rates and extent of this planetary accretion. For
instance, tidal interactions between planets and stars may drive complete
orbital decay during the main sequence. Many planets that survive their stars'
main sequence lifetime will still be engulfed when the host stars become red
giant stars. There is some observational evidence supporting these predictions,
such as a dearth of close-in planets around fast stellar rotators, which is
consistent with tidal spin-up and planet accretion. There remains no clear
chemical evidence for pollution of the atmospheres of main sequence or red
giant stars by planetary materials, but a wealth of evidence points to active
accretion by white dwarfs. In this article, we review the current understanding
of accretion of planetary material, from the pre- to the post-main sequence and
beyond. The review begins with the astrophysical framework for that process and
then considers accretion during various phases of a host star's life, during
which the details of accretion vary, and the observational evidence for
accretion during these phases.Comment: 18 pages, 5 figures (with some redacted), invited revie
Optical modeling and polarization calibration for CMB measurements with ACTPol and Advanced ACTPol
The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization
sensitive upgrade to the Atacama Cosmology Telescope. Located at an elevation
of 5190 m, ACTPol measures the Cosmic Microwave Background (CMB) temperature
and polarization with arcminute-scale angular resolution. Calibration of the
detector angles is a critical step in producing maps of the CMB polarization.
Polarization angle offsets in the detector calibration can cause leakage in
polarization from E to B modes and induce a spurious signal in the EB and TB
cross correlations, which eliminates our ability to measure potential
cosmological sources of EB and TB signals, such as cosmic birefringence. We
present our optical modeling and measurements associated with calibrating the
detector angles in ACTPol.Comment: 12 pages, 8 figures, conference proceedings submitted to Proceedings
of SPIE; added reference in section 2 and merged repeated referenc
A rocky planet transiting a nearby low-mass star
M-dwarf stars -- hydrogen-burning stars that are smaller than 60 per cent of
the size of the Sun -- are the most common class of star in our Galaxy and
outnumber Sun-like stars by a ratio of 12:1. Recent results have shown that M
dwarfs host Earth-sized planets in great numbers: the average number of M-dwarf
planets that are between 0.5 to 1.5 times the size of Earth is at least 1.4 per
star. The nearest such planets known to transit their star are 39 parsecs away,
too distant for detailed follow-up observations to measure the planetary masses
or to study their atmospheres. Here we report observations of GJ 1132b, a
planet with a size of 1.2 Earth radii that is transiting a small star 12
parsecs away. Our Doppler mass measurement of GJ 1132b yields a density
consistent with an Earth-like bulk composition, similar to the compositions of
the six known exoplanets with masses less than six times that of the Earth and
precisely measured densities. Receiving 19 times more stellar radiation than
the Earth, the planet is too hot to be habitable but is cool enough to support
a substantial atmosphere, one that has probably been considerably depleted of
hydrogen. Because the host star is nearby and only 21 per cent the radius of
the Sun, existing and upcoming telescopes will be able to observe the
composition and dynamics of the planetary atmosphere.Comment: Published in Nature on 12 November 2015, available at
http://dx.doi.org/10.1038/nature15762. This is the authors' version of the
manuscrip
The Placiality of Thought
All experience is embodied and, concomitantly, all experience is emplaced. It follows that abstract thought, as a mode of experience, is always emplaced. In what sense is this the case? Following the insights of Maurice Merleau-Ponty, this dissertation seeks to answer this question. A first key insight comes from Phenomenology of Perception: namely, the suggestion that every thought is a bodily experience, and that abstract thought expresses bodily capacities that, through imagination, enter into realms of the virtual. A second key insight comes from Merleau-Ponty\u27s later philosophy, especially The Visible and the Invisible: this is his account of language as a situating power and mode of participating in the world, an account that goes against a common philosophical habit of treating linguistic meaning as operating at a level that is removed from the sensible. With these insights in mind, we can develop a concept of place as that which solicits the bodily capacities through a dynamic process that is incessantly being transfigured; for humans, this transfiguration manifests especially through the situating power of language. This notion of emplacement is further enriched by a concept of metaphor that, building off the work of George Lakoff and Mark Johnson, regards metaphor as the mechanism by which situated, bodily understanding leaps from one placial domain to another in the constitution of new understanding. We can thus understand thought as a mode of inhabitation of place. | 311 page
Trainee teachers' use of blogs as private reflections for professional development
A collaborative research project between Sheffield Hallam University and Nottingham Trent University in the UK investigated the use of blogs with trainee teachers as an alternative to reflective paper-based diaries. An action research case study, involving focus groups of post-graduate (secondary) trainee teachers (one group from each University) was undertaken to determine attitudes and perceptions of blogging as an appropriate tool to support reflective professional development. The findings indicate that the use of blogs by the trainee teachers had a positive impact overall, and provide concrete evidence of their development as emerging professional teachers. Unlike traditional paper-based systems, blogs provided ongoing opportunities for the tutor to assist the trainees in their development as reflective practitioners. This paper seeks to share the findings of this research which the authors believe could be applicable to other areas of Higher Education.</p
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