4,106 research outputs found

    The Development of a Values Assessment Device Based Upon the Assumptions Underlying the Direct Approach to Moral Education

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    The purposes of the present research were two-fold. The first purpose was the development of a test construction strategy by which an objective assessment device, based upon the unique goals of moral education within a specific school district, may be developed. The second purpose was the actual development of a psychometrically sound instrument based upon such goals. To accomplish these aims, seven interrelated studies were conducted involving a total of 775 subjects. The rationale for the nature of the test was based upon the assumptions of the direct approach to moral education. These assumptions are that children should learn and exemplify in their behavior certain values that are viewed by the community as essential to adequate socialization. Such values have been indentified by educators of the Salt Lake City School District. Therefore, the goal of measurement was the development of a test that would discriminate students who exemplify these values in their behavior from. those students who do not. The instrument was developed for the assessment of groups to aid curriculum evaluation in moral education. Disclaimers are made regarding the assessment of individuals using the instrument. The reported studies concerning the development of the test include: (1) the intial writing and field testing of the hypothetical dilemmas and alternative solutions used in the test, (2) the revision of the test based upon the field testing, (3) the item analysis and validation procedures, (4) the cross-validation of selected items, (5) an analysis of the content validity of the dilemmas that compose the test, (6) the establishment of the reliability of the test, and (7) an assessment of the effects of socially desirable response sets on test scores. In addition, normative data regarding test scores for each grade tested and a parent group were presented. The instrument developed through these procedures is an objective group test, applicable to grades 5 through 12. A content validity study provided reasonable evidence that the dilemmas that compose the test are logically related to the value goals proposed by district personnel. Studies of the reliability of the test revealed reliability coefficients from .82 (stability) to .92 (internal consistency). The concurrent validity of the test was established by selecting items that discriminated between groups of students who were identified as either exemplary of the district values or non-exemplary of the district values. These items were then successfully cross - validated on an independent sample of similar criterion groups. In addition, two studies related to the effects of socially desirable response sets on test scores were conducted. The limitations of the present research are discussed and suggestions for further research regarding the instrument are made

    Structural basis for sequence specific DNA binding and protein dimerization of HOXA13.

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    The homeobox gene (HOXA13) codes for a transcription factor protein that binds to AT-rich DNA sequences and controls expression of genes during embryonic morphogenesis. Here we present the NMR structure of HOXA13 homeodomain (A13DBD) bound to an 11-mer DNA duplex. A13DBD forms a dimer that binds to DNA with a dissociation constant of 7.5 nM. The A13DBD/DNA complex has a molar mass of 35 kDa consistent with two molecules of DNA bound at both ends of the A13DBD dimer. A13DBD contains an N-terminal arm (residues 324 - 329) that binds in the DNA minor groove, and a C-terminal helix (residues 362 - 382) that contacts the ATAA nucleotide sequence in the major groove. The N370 side-chain forms hydrogen bonds with the purine base of A5* (base paired with T5). Side-chain methyl groups of V373 form hydrophobic contacts with the pyrimidine methyl groups of T5, T6* and T7*, responsible for recognition of TAA in the DNA core. I366 makes similar methyl contacts with T3* and T4*. Mutants (I366A, N370A and V373G) all have decreased DNA binding and transcriptional activity. Exposed protein residues (R337, K343, and F344) make intermolecular contacts at the protein dimer interface. The mutation F344A weakens protein dimerization and lowers transcriptional activity by 76%. We conclude that the non-conserved residue, V373 is critical for structurally recognizing TAA in the major groove, and that HOXA13 dimerization is required to activate transcription of target genes

    Local Spectral Optimisation for Robin Problems with Negative Boundary Parameter on Quadrilaterals

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    We investigate the Robin eigenvalue problem for the Laplacian with negative boundary parameter on quadrilateral domains of fixed area. In this paper, we prove that the square is a local maximiser of the first eigenvalue with respect to the Hausdorff metric. We also provide asymptotic results relating to the optimality of the square for extreme values of the Robin parameter.Comment: 32 pages, 2 figure

    Bats of Barbados

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    The chiropteran fauna of Barbados includes representatives of four families — Noctilionidae, Phyllostomidae, Vespertilionidae, and Molossidae — including 1 piscivore (Noctilio leporinus), 1 omnivore (Brachyphylla cavernarum), 1 pollenivore/nectarivore (Monophyllus plethodon), 1 frugivore (Artibeus jamaicensis), and 2 insectivorous species (Myotis nyctor and Molossus molossus). Despite an early report, we believe that preponderance of the evidence available at this time is that E. fuscus is not part of the fauna of Barbados. The Barbadian chiropteran fauna of 6 species is much smaller than those on the four neighboring Lesser Antillean islands to the west and north. We believe that this is primarily the result of two factors—geological age and geographic isolation. Our work indicates that populations of the 6 species of bats on Barbados are in good condition in all cases, but only for Artibeus jamaicensis and Molossus molossus are the populations large enough to not be of ongoing concern. The maintenance of the chiropteran fauna can best be served by three management actions — preservation of caves and associated gullies, forests, and hydrological systems

    Bats of Barbados

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    The chiropteran fauna of Barbados includes representatives of four families — Noctilionidae, Phyllostomidae, Vespertilionidae, and Molossidae — including 1 piscivore (Noctilio leporinus), 1 omnivore (Brachyphylla cavernarum), 1 pollenivore/nectarivore (Monophyllus plethodon), 1 frugivore (Artibeus jamaicensis), and 2 insectivorous species (Myotis nyctor and Molossus molossus). Despite an early report, we believe that preponderance of the evidence available at this time is that E. fuscus is not part of the fauna of Barbados. The Barbadian chiropteran fauna of 6 species is much smaller than those on the four neighboring Lesser Antillean islands to the west and north. We believe that this is primarily the result of two factors—geological age and geographic isolation. Our work indicates that populations of the 6 species of bats on Barbados are in good condition in all cases, but only for Artibeus jamaicensis and Molossus molossus are the populations large enough to not be of ongoing concern. The maintenance of the chiropteran fauna can best be served by three management actions — preservation of caves and associated gullies, forests, and hydrological systems

    Surveying the Inner Halo of the Galaxy with 2MASS-Selected Horizontal Branch Candidates

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    We use 2MASS photometry to select blue horizontal branch (BHB) candidates covering the sky |b|>15 deg. A 12.5<J<15.5 sample of BHB stars traces the thick disk and inner halo to d<9 kpc, with a density comparable to that of M giant stars. We base our sample selection strategy on the Century Survey Galactic Halo Project, a survey that provides a complete, spectroscopically-identified sample of blue stars to a similar depth as the 2MASS catalog. We show that a -0.20<(J-H)_0<0.10, -0.10<(H-K)_0<0.10 color-selected sample of stars is 65% complete for BHB stars, and is composed of 47% BHB stars. We apply this photometric selection to the full 2MASS catalog, and see no spatial overdensities of BHB candidates at high Galactic latitude |b|>50 deg. We insert simulated star streams into the data and conclude that the high Galactic latitude BHB candidates are consistent with having no ~5 deg wide star stream with density greater than 0.33 objects deg^-2 at the 95% confidence level. The absence of structure suggests there have been no major accretion events in the inner halo in the last few Gyr. However, at low Galactic latitudes a two-point angular correlation analysis reveals structure on angular scales <1 deg. This structure is apparently associated with stars in the thick disk, and has a physical scale of 10-100 pc. Interestingly, such structures are expected by cosmological simulations that predict the majority of the thick disk may arise from accretion and disruption of satellite mergers.Comment: 11 pages, including figures. Accepted by AJ with minor revision
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