1,412 research outputs found
Teaching Students with Special Needs in School-Based, Agricultural Education: A Historical Inquiry
The purpose of this historical study was to investigate the inclusion of students with special needs in school-based, agricultural education as reported by The Agricultural Education Magazine and the Journal of Agricultural Education over a time period of six decades. The impact of landmark legislation, such as the Vocational Education Act of 1963, the Elementary and Secondary Education Act of 1965, the Education for All Handicapped Children Act of 1975, and the Individuals with Disabilities Act of 1990, were examined. This legislation motivated and supported agricultural educationâs efforts to meet the learning needs of special education students by providing modified lessons and learning environments, inclusive SAEs and FFA activities, and focused teacher preparation. Challenges and concerns regarding the placement of special needs students in school-based, agricultural education are also discussed, as well as opportunities for related research in the future, especially about their participation in the FFA
Astrophysical Effects of Scalar Dark Matter Miniclusters
We model the formation, evolution and astrophysical effects of dark compact
Scalar Miniclusters (``ScaMs''). These objects arise when a scalar field, with
an axion-like or Higgs-like potential, undergoes a second order phase
transition below the QCD scale. Such a scalar field may couple too weakly to
the standard model to be detectable directly through particle interactions, but
may still be detectable by gravitational effects, such as lensing and baryon
accretion by large, gravitationally bound miniclusters. The masses of these
objects are shown to be constrained by the Ly power spectrum to be less
than , but they may be as light as classical axion
miniclusters, of the order of . We simulate the formation and
nonlinear gravitational collapse of these objects around matter-radiation
equality using an N-body code, estimate their gravitational lensing properties,
and assess the feasibility of studying them using current and future lensing
experiments. Future MACHO-type variability surveys of many background sources
can reveal either high-amplification, strong lensing events, or measure density
profiles directly via weak-lensing variability, depending on ScaM parameters
and survey depth. However, ScaMs, due to their low internal densities, are
unlikely to be responsible for apparent MACHO events already detected in the
Galactic halo. A simple estimate is made of parameters that would give rise to
early structure formation; in principle, early stellar collapse could be
triggered by ScaMs as early as recombination, and significantly affect cosmic
reionization.Comment: 13 pages, 12 figures. Replaced to reflect published versio
A sensitive genetic-based detection capability for Didymosphenia geminata
It is now well recognized that the increase in global transportation over the last two decades has brought with it an increased potential for the introduction of unwanted microorganisms (aquatic or terrestrial) that may have drastic effects on human and ecosystem health and agriculture. We have developed and validated a unique genetic fingerprinting tool for D. geminata. In concert, we developed field collection and preservation techniques specific for D. geminata along with genetic-based procedures that can now reliably detect D. geminate from a complex environmental community with a high degree of sensitivity. Recent work (Phase 2) has shown that the described methods will provide detection levels from <1 â 10,000 cells ml-1. We contend that the genetic based detection approaches used in this study offer great promise to meet the increasing demands to monitor the global threat from invasive micro-organisms
The Words of Our Ancestors: Kinship, Tradition, and Moral Codes
In this paper we use the cross-cultural record to identify the behavioral rules of conduct, and the system supporting those rules, that are found in traditional societies, such as tribal societies. We then draw on the historical record to identify the behavioral rules of conduct, and the system supporting those rules that were found in the early state. The proposal tested here is that in traditional societies the behavioral rules of conduct and the systems that support them (e.g., processes for identifying guilt, punishing offenders, enacting legislation, preventing conflict) are aimed at promoting enduring, cooperative relationships among individuals who are identified as kin through common ancestry. The assumption underlying this proposal is that once human females increased their investment in offspring, cultural strategies to protect those offspring became more important. A moral system, which is the term we use to refer to the early system of behavioral codes, protected offspring by turning conspecific threats into the protectors, providers, and educators of children. It did this by creating a strong kinship system, the members of which were bound by common ancestry (actual or metaphorical), thus tying individuals into enduring, cooperative relationships by using culture to encourage them to honor ongoing duties to one another. This kinship-based moral system is significantly different from that found in societies in which the majority of interactions are with non-kin, interactions often center on the exchange of good and services, and traditions have largely been broken down. We refer to this second system as a system of law and argue that this distinction between moral and legal systems has implications for attempts to explain the evolutionary basis of human cooperation
Cobalt(II) complexes with azole-pyridine type ligands for non-aqueous redox-flow batteries:tunable electrochemistry via structural modification
Abstract A single species redox flow battery employing a new class of cobalt(II) complexes with âtunableâ tridentate azole-pyridine type ligands is reported. Four structures were synthesised and their electrochemical, physical and battery characteristics were investigated as a function of successive substitution of the ligand terminal pyridyl donors. The Co(II/I) and Co(III/II) couples are stable and quasi-reversible on gold and glassy carbon electrodes, however redox potentials are tunable allowing the cobalt potential difference to be preferentially increased from 1.07 to 1.91 V via pyridine substitution with weaker Ï-donating/Ï-accepting 3,5-dimethylpyrazole groups. The charge-discharge properties of the system were evaluated using an H-type glass cell and graphite rod electrodes. The complexes delivered high Coulombic efficiencies of 89.7â99.8% and very good voltaic efficiencies of 70.3â81.0%. Consequently, energy efficiencies are high at 63.1â80.8%, marking an improvement on other similar non-aqueous systems. Modification of the ligands also improved solubility from 0.18 M to 0.50 M via pyridyl substitution with 3,5-dimethylpyrazole, though the low solubility of the complexes limits the overall energy capacity to between 2.58 and 12.80 W h Lâ1. Preliminary flow cell studies in a prototype flow cell are also demonstrated
White Noise from Dark Matter: 21 cm Observations of Early Baryon Collapse
In concordance cosmology, dark matter density perturbations generated by
inflation lead to nonlinear, virialized minihalos, into which baryons collapse
at redshift . We survey here novel baryon evolution produced by a
modification of the power spectrum from white noise density perturbations at
scales below (the smallest scales currently measured
with the Lyman- forest). Exotic dark matter dynamics, such as would
arise from scalar dark matter with a late phase transition (similar to an
axion, but with lower mass), create such an amplification of small scale power.
The dark matter produced in such a phase transition collapses into minihalos,
with a size given by the dark matter mass within the horizon at the phase
transition. If the mass of the initial minihalos is larger than , the modified power spectrum is found to cause widespread baryon
collapse earlier than standard CDM, leading to earlier gas heating. It
also results in higher spin temperature of the baryons in the 21 cm line
relative to CDM at redshifts if the mass of the minihalo is
larger than . It is estimated that experiments probing 21 cm
radiation at high redshift will contribute a significant constraint on dark
matter models of this type for initial minihalos larger than .
Early experiments reaching to will constrain minihalos down to
.Comment: 8 pages, 9 figure
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