624 research outputs found

    Elementary Principals\u27 Perceptions of Special Education Teachers\u27 Performance Evaluation Process

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    Evidence suggests that current special education teacher evaluation systems may not accurately reflect these teachers\u27 unique duties and responsibilities. In a Midwestern, urban school district, the teacher evaluation system was not adequately aligned with the performance expectations of special education teachers. Guided by Danielson\u27s framework for teaching, this qualitative case study explored elementary school principals\u27 perceptions of teacher evaluation approaches, perceived effectiveness of these approaches, applications of key indicators of teaching quality, and barriers preventing accurate evaluations of special education teachers\u27 performance. An online survey comprised of closed- and open-ended questions was distributed to 445 principals in the district with 97 responding. Descriptive analysis of closed-ended items indicated 70% of respondents perceived current evaluation methods to be insufficiently differentiated for special education teachers\u27 roles and 90% reported a need for additional measures of effectiveness to be used. Thematic analysis of open-ended survey responses confirmed the need for differentiated evaluation approaches to address a misalignment of key effectiveness indicators for special education teachers and revealed barriers to accurate evaluation including resource constraints. In response to these findings, a position paper with policy recommendation prescribed the revision of the current teacher evaluation practices to address the unique roles of special education teachers. Refining special education teacher evaluation practices may contribute to positive social change by aligning the evaluation process with special education teachers\u27 duties and responsibilities, thereby improving teacher performance and potentially increasing student achievement over time

    Thin-film fixed-bed reactor (TFFBR) for solar photocatalytic inactivation of aquaculture pathogen Aeromonas hydrophila

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    Background: Outbreaks of infectious diseases by microbial pathogens can cause substantial losses of stock in aquaculture systems. There are several ways to eliminate these pathogens including the use of antibiotics, biocides and conventional disinfectants, but these leave undesirable chemical residues. Conversely, using sunlight for disinfection has the advantage of leaving no chemical residue and is particularly suited to countries with sunny climates. Titanium dioxide (TiO2) is a photocatalyst that increases the effectiveness of solar disinfection. In recent years, several different types of solar photocatalytic reactors coated with TiO2 have been developed for waste water and drinking water treatment. In this study a thin-film fixed-bed reactor (TFFBR), designed as a sloping flat plate reactor coated with P25 DEGUSSA TiO2, was used. Results: The level of inactivation of the aquaculture pathogen Aeromonas hydrophila ATCC 35654 was determined after travelling across the TFFBR under various natural sunlight conditions (300- 1200 W m-2), at 3 different flow rates (4.8, 8.4 and 16.8 L h-1). Bacterial numbers were determined by conventional plate counting using selective agar media, cultured (i) under conventional aerobic conditions to detect healthy cells and (ii) under conditions designed to neutralise reactive oxygen species (agar medium supplemented with the peroxide scavenger sodium pyruvate at 0.05% w/v, incubated under anaerobic conditions), to detect both healthy and sub-lethally injured (oxygen-sensitive) cells. The results clearly demonstrate that high sunlight intensities (≥600 W m-2) and low flow rates (4.8 L h-1) provided optimum conditions for inactivation of A. hydrophila ATCC 3564, with greater overall inactivation and fewer sub-lethally injured cells than at low sunlight intensities or high flow rates. Low sunlight intensities resulted in reduced overall inactivation and greater sub-lethal injury at all flow rates.Conclusions: This is the first demonstration of the effectiveness of the TFFBR in the inactivation of Aeromonas hydrophila at high sunlight intensities, providing proof-of-concept for the application of solar photocatalysis in aquaculture systems

    Allelopathic potential of radish (Raphanus sativus L.) on germination and seedling growth of some plants species.

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    The purpose of this study was to determine the allelopathic activity of shoot and root aqueous extracts of radish (Raphanus sativus L.) on germination and seedling growth of bread wheat (Triticum aesitivum L.), barley (Hordeum vulgare), wild barley (Hordeum spontaneum L.), and wild oat (Avena fatua L.). The concentration was used in this study were (0%, 15%, 30%, 45%, and 60%). The experiment was conducted in a sterilized Petri dish for 10 days at 22 °C, with the experimental units arranged in a randomized complete design. In general, the study's findings revealed the significant effects of concentration levels (15%, 30%, 45%, 60% compared to control treatments. The concentration 40% and 60% were completely inhibiting the seedling germination and growth while the lowest concentration 15% had the least negative effect on seedling growth and germination. Aqueous extract of shoot radish was more effective on seed germination than root of radish. So, all results recommended that the aqueous extract of shoot and root of radish may act as a bioherbicide to inhibit germination and seedling growth

    Slave-Boson Functional-Integral Approach to the Hubbard Model with Orbital Degeneracy

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    A slave-boson functional-integral method has been developed for the Hubbard model with arbitrary, orbital degeneracy DD. Its saddle-point mean-field theory is equivalent to the Gutzwiller approximation, as in the case of single-band Hubbard model. Our theory is applied to the doubly degenerate (D=2D = 2) model, and numerical calculations have been performed for this model in the paramagnetic states. The effect of the exchange interaction on the metal-insulator (MI) transition is discussed. The critical interaction for the MI transition is analytically calculated as functions of orbital degeneracy and electron occupancy.Comment: Latex 20 pages, 9 figures available on request to [email protected] Note: published in J. Physical Society of Japan with some minor modification

    Multiplet Effects in the Quasiparticle Band Structure of the f1f2f^1-f^2 Anderson Model

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    In this paper, we examine the mean field electronic structure of the f1f2f^1-f^2 Anderson lattice model in a slave boson approximation, which should be useful in understanding the physics of correlated metals with more than one f electron per site such as uranium-based heavy fermion superconductors. We find that the multiplet structure of the f2f^2 ion acts to quench the crystal field splitting in the quasiparticle electronic structure. This is consistent with experimental observations in such metals as UPt3UPt_3.Comment: 9 pages, revtex, 3 uuencoded postscript figures attached at en

    Epidemiological Insights into TORCH Infections in the Population of Erbil City

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    A seroepidemiological study of the TORCH panel was conducted on inhabitants of Erbil City to provide updated baseline data on TORCH prevalence. 508 individuals were included in this study. 218 (42.91%) were females and 290 (57.09%) were males. Their ages ranged from 13 to 63 year, the majority being within the age group (21-30 years), 162 (31.89%), (P < 0.05). 20 individuals (3.94%) tested positive for anti-TOX IgG antibodies. One of the 20 (5%) tested positive for anti-TOX IgM antibodies, who was a 32-year-old female. 128 individuals (25.2%) (all females) tested positive for anti-Rubella IgG antibodies. 40 individuals (7.87%) were positive for anti-CMV IgG antibodies. One of the 40 (2.5%) also tested positive for anti-CMV IgM antibodies, who was a 26-year-old male. 18 individuals (3.54%) tested positive for anti-HSV-1 IgG antibodies. One of the 18 (5.56%) also tested positive for anti-HSV-1 IgM antibodies. One 18-year-old male (0.2%) tested positive for anti-HSV-2 IgG antibodies, and none were positive for anti-HSV-2 IgM antibodies. The results suggest the presence of Toxoplasma, CMV, HSV-1 and HSV-2 infections among the community, the majority (P < 0.05) being CMV followed by TOX and HSV-1 and finally HSV-2. The positive IgG results of Rubella are most probably due to the obligatory vaccination program for females. Despite the fact that the majority of positive cases were for IgG, enhancing vaccination efforts and providing comprehensive health education is crucial for enhancing the well-being of the Erbil population

    Time-dependent Gutzwiller approximation for the Hubbard model

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    We develop a time-dependent Gutzwiller approximation (GA) for the Hubbard model analogous to the time-dependent Hartree-Fock (HF) method. The formalism incorporates ground state correlations of the random phase approximation (RPA) type beyond the GA. Static quantities like ground state energy and double occupancy are in excellent agreement with exact results in one dimension up to moderate coupling and in two dimensions for all couplings. We find a substantial improvement over traditional GA and HF+RPA treatments. Dynamical correlation functions can be easily computed and are also substantially better than HF+RPA ones and obey well behaved sum rules.Comment: 4 pages, 2 figure

    Diagrammatic method for investigating universal behavior of impurity systems

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    The universal behavior of magnetic impurities in a metal is proved with the help of skeleton diagrams. The energy scales are derived from the structure of the skeleton diagrams. A minimal set of skeleton diagrams is sorted out that scales exactly. For example, the non-crossing approximation for the Anderson impurity model can describe the crossover phenomenon. The universal Wilson-number is calculated within the non-crossing approximation. The method allows for an assessment of various approximations for impurity Hamiltonians.Comment: 21 pages, 3 figure

    Exciton effects in a scaling theory of intermediate valence and Kondo systems

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    An interplay of the Kondo scattering and exciton effects (d-f Coulomb interaction) in the intermediate valence systems and Kondo lattices is demonstrated to lead to an essential change of the scaling behavior in comparison with the standard Anderson model. In particular, a marginal regime can occur where characteristic fluctuation rate is proportional to flow cutoff parameter. In this regime the "Kondo temperature" itself is strongly temperature dependent which may give a key to the interpretation of controversial experimental data for heavy fermion and related systems.Comment: 4 pages, 4 figure
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