The Effect of the Ethnic Identification of Teachers With Principals on the Teachers\u27 Perceptions of the Principals\u27 Leadership Behavior

The problem of this study was to determine whether the ethnic identification of teachers with their school principals affected the teachers\u27 perception of the principals\u27 leadership behavior. This study followed the ex-post-facto design of a co-relational study. Twelve dimensions of the Leader Behavior Description Questionnaire, Form 12 (LBDQ-XII) were selected to assess the perception of teachers belonging to three different ethnic groups of the leadership behavior of principals belonging to the three ethnic groups. The statistical analysis of the data for hypotheses 1 through 7 was intended to determine significant differences in the ratings by white, black, and Spanish language origin (SLO) teachers of the leadership ability of principals from the three ethnic groups. The differences showing significance in the study warranted the following conclusions. (1) Teachers from different ethnic groups do not perceive a difference in the leadership ability of principals when assessing overall leadership behavior. (2) The perception of teachers of effective leadership behavior is different when assessing the overall leadership ability of principals from different ethnic groups. (3) Teachers from different ethnic groups manifest perceptual differences in their assessment of the overall leadership behavior of principals from different ethnic origins. SLO teachers, particularly, perceive a difference in the leadership ability of their principals, with principals from their own ethnic group being considered more effective leaders (higher leader behavior scores). (4) Teachers, without regard for ethnic group membership, have different perceptions of leadership ability in their principals when twelve dimensions of leadership behavior are considered. Teachers give more consideration to some dimensions (higher leader behavior scores) than others. (5) Teachers from different ethnic groups hold different perceptions of leadership ability in principals, when various dimensions of leadership behavior are considered. The differences perceived by teachers lie in the areas of Tolerance of Uncertainty and Tolerance of Freedom, on which white teachers assess their leaders as more capable, and in Production Emphasis, on which principals are considered more effective by SLO and black teachers. (6) The perception of teachers of effective leadership behavior involving various dimensions of leadership is different when assessing the leadership ability of principals from different ethnic groups. Principals are perceived differently by teachers in Production Emphasis, on which SLO principals are considered more capable; in Predictive Accuracy, on which SLO and white principals are considered to have more ability; and, in Integration and Influence with Superiors, on which SLO principals are assessed as possessing a higher leadership capacity. (7) Teachers from different ethnic groups manifest perceptual differences in their assessment of particular dimensions of the leadership ability of principals from different ethnic origins. White principals are considered by white teachers to be more effective on Tolerance of Uncertainty, Tolerance of Freedom, and Predictive Accuracy. Black teachers perceive SLO principals as more able leaders on Influence with Superiors. SLO teachers assess SLO principals as more effective on Consideration, Predictive Accuracy, Production Emphasis, and Integration. Ethnicity does affect the perception of teachers of the leadership ability of principals. Teachers from different ethnic groups evaluate leadership behavior differently, and principals belonging to different ethnic groups are assessed differently on their leadership ability

A Novel Platelet Activating Factor Receptor Antagonist Reduces Cell Infiltration and Expression of Inflammatory Mediators in Mice Exposed to Desiccating Conditions after PRK

Purpose. To study the contribution of a novel PAF receptor antagonist LAU-0901 in the modulation of the increased inflammatory response in mice exposed to dessicating conditions (DE) after PRK. Methods. Eighty 13-14 week old female Balb/C mice were used. They were divided into two groups: One group was treated with LAU-0901 topical drops. The other group was treated with vehicle. In each group ten mice served as controls and ten were placed in DE. The other twenty mice underwent bilateral PRK and were divided in two additional groups: ten mice remained under normal conditions (NC) and the other ten were exposed to DE. After 1 week all animals underwent in vivo confocal microscopy, immunostaining and western blotting analysis. Results. Confocal microscopy showed an increased number of reflective structures in the corneal epithelium after PRK and exposure to DE in eyes treated with vehicle as compared to eyes treated with LAU-090). Significant decrease of COX-2 and Arginase I expression and reduced alpha SMA cells was observed after PRK and exposure to DE in eyes treated with LAU-0901. Discussion: Exposure of mice to a DE after PRK increases the epithelial turnover rate. PAF is involved in the inflammatory cell infiltration and expression of inflammatory cytokines that follow PRK under DE

Taxonomy and conservation in Higher Plants and Bryophytes in the Mediterranean Area

The Mediterranean Region is among the areas of the world richest in wild and cultivated taxa. Extinctions in the Mediterranean area are bound to have occurred in historical times but they are not documented. The probable and documented cases of plant extinction in specific areas within the Mediterranean are equivalent to 0.25% of total species-by-area records. Species with a large range are more prone to local population size fluctuations and eventual extinction than species with a reduced population. Small islands floras are more prone to extinction than those on large islands and on the mainland. Reliability of our data on Mediterranean plant extinctions is poor. New emphasis on floristic research is needed to boost our deficient knowledge of the Mediterranean flora. A closer collaboration between scholars and amateurs can increase floristic knowledge and also help unravel taxonomic problems

First record of Sphaeralcea bonariensis (Cav.) Griseb. (Malvaceae) as a casual alien species in the Mediterranean area

Sphaeralcea bonariensis (Cav.) Griseb. is here reported for the first time as alien species in Italy and in the Mediterranean area. It is a perennial shrub native to Southern America, where it is often considered a ruderal species frequent in cultivated areas. It was found in a population of a few individuals within Opuntia ficus-indica groves of Rocca Palumba territory (Western Sicily). Actually, due to short-term observational period and the low number of plants, Sphaeralcea bonariensis should be considered as a casual species in Italy. The ecological characteristics of the growing stand and the consistency of the population, as well as the possible causes of its introduction, are briefly discussed

Studio botanico finalizzato al recupero del paesaggio vegetale dell’Area archeologica di Lilibeo presso Marsala (Sicilia occidentale)

Viene presentato uno studio botanico volto al recupero del paesaggio vegetale dell’Area Archeologica di Capo Lilibeo (Marsala). Il progetto prevede l’eradicazione delle specie esotiche ad alto grado di invasività quali Ailanthus altissima e Vachellia karroo, il risanamento fitosanitario dei viali di Palme delle Canarie e la sostituzione degli individui malformati con specie ornamentali altamente decorative e a basso grado di invasività. E’ previsto l’impiego di specie afferenti agli stadi più evoluti dei sigmataxa Chamaeropo humilis- Querceto calliprini sigmetum ed al Pistacio lentisci- Chamaeropo humilis sigmetum al fine di assicurare i migliori risultati contro l’espansione della componente esotica ad alto grado di invasività.A plan based on a previous botanical investigation is presented here in order of recovering the plant landscape of the archaeological area o fthe Lilibeo Cape near Marsala. It includes the uprooting of highly invasive exotics such as Ailanthus altissima and Vachellia karroo, the recovery of the Canary date palms the replacement of disfigured tree specimens using less invasive ornamental trees. In addition, species belonging to the final stages of the sigmataxa Chamaeropo humilis- Querceto calliprini sigmetum and of the Pistacio lentisci- Chamaeropo humilis sigmetum in order to oppose successful barriers against the most invasive aliens

Pentamethylcyclopentadienyl-dicarbollide derivatives of scandium

The reactions of [Cp*ScCl_2]_x (Cp* = (η^5-C_5Me_5)) with Na_2[C_2B_9H_(11) or [Cp*ScMe_2]_x, with C_2B_9H_(13), followed by treatment with THF yield Cp*(C_2B_9H_(11))Sc(THF)_3. Alkylation of Cp*-(C_2 B_9 H_(11)) with LiCH(SiMe_3)_2 yields Cp(C_2B_9H_(11))ScCH(SiMe_3)_2Li(THF)_3, and {[Cp*(C_2B_9H_(11))ScCH(SiMe_3)_2]_2Li}-Li(THF)_3, which is obtained by its recrystallization from pentane/toluene, has been characterized structurally. This alkyl derivative reacts slowly with H_2 to yield [Cp*(C_2B_9H_(11))SCH]_2[LiTHF)_n]_2, a surprisingly reactive scandium hydride dimer. Once again, recrystallization from toluene affords a crystalline form with less coordinated THF, [Cp*(C_2B_9H_(11))ScH]_2[Li(THF)_2•(3/2)(C_6H_5CH_)3, whose structure reveals that the two anionic [Cp*(C_2B_9H_(11))ScH]^- fragments are held together by reciprocal B-H dative bonding from the dicarbollide ligand to the electron deficient scandium. The potential of pentamethylcyclopentadienyl-dicarbollide derivatives of scandium to serve as efficient a olefin polymerization catalysts is discussed

A tribenzylidenemethane–tantalum compound: some experiences with 'inversion twinning'

The six-electron-donating ligand tribenzylidenemethandiide has been used to form a tantalum (group 5) mimic, (η^5-cyclopentadienyl)(η^4-tribenzylidenemethandiide)dimethyltantalum, of a group 4 bent metallocene. The material crystallizes with two molecules in the asymmetric unit with quite different packing arrangements, although the overall structures of the two are similar. The Cp and methyl ligands are disordered about a threefold axis. Crystal data: [Ta{(C_7H_6)_3C}(C_5H_5)(CH_3), trigonal P31c, with a = 12.681 (3), c = 16.124 (5) Å, V = 2245.5 (7) Å^3, T = 293 K, Z = 4, M_r = 558.47, D_x = 1.65 g cm^(-3), F(000) = 1104, Mo Kα, λ = 0.71073 Å, µ = 4.91 mm^(-1), R = 0.020 for 1319 reflections with F_o > 4σ(F_o); S = 2.18. Because of crystal decay, three separate crystals were needed for a full data set. These polar (but achiral) crystals showed apparently differing amounts of inversion twinning, leading to problems in accurately merging the three data sets and refining the structure. These problems are discussed briefly

Do ultrafast exciton-polaron decoherence dynamics govern photocarrier generation efficiencies in polymer solar cells?

All-organic-based photovoltaic solar cells have attracted considerable attention because of their low-cost processing and short energy payback time. In such systems the primary dissociation of an optical excitation into a pair of photocarriers has been recently shown to be extremely rapid and efficient, but the physical reason for this remains unclear. Here, two-dimensional photocurrent excitation spectroscopy, a novel non-linear optical spectroscopy, is used to probe the ultrafast coherent decay of photoexcitations into charge-producing states in a polymer:fullerene based solar cell. The two-dimensional photocurrent spectra are interpreted by introducing a theoretical model for the description of the coupling of the electronic states of the system to an external environment and to the applied laser fields. The experimental data show no cross-peaks in the two-dimensional photocurrent spectra, as predicted by the model for coherence times between the exciton and the photocurrent producing states of 20\,fs or less

First record of Temnosewellia minor (Platyhelminthes, Temnocephalidae) in Sicily, with a plea for a re-examination of the identity of the publicly available molecular sequences of the genus

Ectosymbiotic temnocephalan flatworms belonging to the genus Temnosewellia were collected on Cherax destructor in an aquaculture farm in Sicily, Italy. This represents the first record of a temnocephalan species for the fauna of the island. Morphological and molecular identification of the collected specimens proved that they belong to the allochthonous species Temnosewellia minor, which was introduced along with crayfishes bred in aquaculture farms. The phylogenetic analyses carried out for the molecular identification of the Sicilian population highlighted some inconsistencies in the grouping of the Temnosewellia sequences available online, thus stressing the opportunity of a careful re-examination of the voucher samples and their identifications. The risks of its unwary introduction in the wild and the need of monitoring its possible impacts on native biota are briefly discussed