7,813 research outputs found

    Redesigning a Principal Preparation Program: A Continuous Improvement Model

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    The paper describes a mixed methods approach to the process of redesigning a principal preparation program. A qualitative approach was used to gather data from superintendents within the geographic area using a focused group approach, whereas, quantitative data, were gathered through a survey of program graduates with questions aligned to the three domains of the TExES examination for principal certification. Texas universities that offered principal preparation programs were studied and analyzed as a backdrop to the study. The superintendent responses identified various strengths and weaknesses in the delivery of the program. The graduate survey results indicated low satisfaction ratings in principal preparation in the three domains as the program currently exists. The study proposes a model for redesigning principal preparation programs based on the findings. (Contains 3 tables and 1 figure.

    Long-term comparison of the ionospheric F2 layer electron density peak derived from ionosonde data and Formosat-3/COSMIC occultations

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    Electron density profiles (EDPs) derived from GNSS radio occultation (RO) measurements provide valuable information on the vertical electron density structure of the ionosphere and, among others, allow the extraction of key parameters such as the maximum electron density NmF2 and the corresponding peak height hmF2 of the F2 layer. An efficient electron density retrieval method, developed at the UPC (Barcelona, Spain), has been applied in this work to assess the accuracy of NmF2and hmF2 as determined from Formosat-3/COSMIC (F-3/C) radio occultation measurements for a period of more than half a solar cycle between 2006 and 2014. Ionosonde measurements of the Space Physics Interactive Data Resource (SPIDR) network serve as a reference. Investigations on the global trend as well as comparisons of the F2 layer electron density peaks derived from both occultations and ionosonde measurements are carried out. The studies are performed in the global domain and with the distinction of different latitude sectors around the magnetic equator ±[0°, 20°], ±]20°, 60°] and ±]60°, 90°]) and local times (LT) accounting for different ionospheric conditions at night (02:00 LT ± 2 h), dawn (08:00 LT ± 2 h), and day (14:00 LT ± 2 h). The mean differences of F2 layer electron density peaks observed by F-3/C and ionosondes are found to be insignificant. Relative variations of the peak differences are determined in the range of 22%–30% for NmF2 and 10%–15% for hmF2. The consistency of observations is generally high for the equatorial and mid-latitude sectors at daytime and dawn whereas degradations have been detected in the polar regions and during night. It is shown, that the global averages of NmF2 and hmF2 derived from F-3/C occultations appear as excellent indicators for the solar activity.JRC.G.5-Security technology assessmen

    Application of liquid chromatography/mass spectrometry in assessment of potential use of azadirachtins (TreeAzin ™ ) against Asian longhorned beetle

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    Azadirachtins are natural triterpenoid compounds derived from Neem tree extracts with potential for use as systemic insecticides against invasive wood-boring insect pests. In this work, a sensitive and selective analytical method has been developed for the simultaneous determination of azadirachtin A and azadirachtin B (3-tigloylazadirachtol) in foliage and twigs of various tree species. Samples were mixed with C18 and primary-secondary amine (PSA), and extracted with acetonitrile. Then, an aliquot of the raw extract was 10-fold diluted with water and directly analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). The method was validated in foliage and twig matrices of four different tree species (London Plane Tree, Red/Freemani Maple, Norway Maple and Sugar Maple) that are known hosts of the exotic invasive insect pest – Asian Longhorn Beetle (ALB). Analytical results for replicate (N = 5) samples, fortified at 0.01, 0.1 and 1 mg kg , showed good recoveries (86 – 119%) and precision (<20% RSD). The methodology was successfully applied to the analysis of 200 samples taken from a field experiment designed to investigate uptake, translocation and expression of azadirachtins in representative high-value urban trees followed by stem injection with TreeAzinTM

    Degradation of seventeen contaminants of emerging concern in municipal wastewater effluents by sonochemical advanced oxidation processes

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    The simultaneous degradation of seventeen emerging concern pollutants in effluent from the municipal wastewater treatment plant (MWTP) of Bogotá-Colombia was studied using high frequency ultrasound (375 kHz). The considered compounds in the effluent corresponded to pharmaceuticals (diclofenac, carbamazepine, venlafaxine, ciprofloxacin, norfloxacin, valsartan, losartan, irbesartan, sulfamethoxazole, clarithromycin, azithromycin, erythromycin, metronidazole, trimethoprim and the high potentiality of the sono-photo-Fenton/oxalic acid system for the pollutants elimination in real-world wastewater matrices. clindamycin); cocaine and its major metabolite benzoylecgonine. Due to limitation of the MWTP for the pollutants elimination, ultrasound was applied to remove these compounds. Interestingly, ultrasonic physical action led to releasing of ciprofloxacin, norfloxacin, diclofenac and sulfamethoxazole from suspended solids, whereas the chemical effects induced degradation of the rest of compounds. For the latter ones, an interesting correlation between the sonodegradation and arithmetic multiplication between hydrophobicity and concentration of pollutants was established. Afterwards, the sonochemical process was complemented with ferrous ions (sono-Fenton), ferrous ions plus light (sono-photo-Fenton) or ferrous ions plus light in presence of oxalic acid (sono-photo-Fenton/oxalic acid). Additionally, to clarify fundamental aspects of the different systems, individual treatments in distilled water of a model pollutant (valsartan) were performed. The complemented processes significantly enhanced all compounds degradation, following the order: sono-photo-Fenton/oxalic acid > sono-photo-Fenton ~ sono-Fenton > sonochemistry. The Fe2+ addition improved the pollutants elimination by generation of more hydroxyl radicals in the solution bulk. Meanwhile, oxalic acid avoided Fe3+ precipitation favoring the iron catalytic cycle. Thus, the work demonstrate

    Peptide glutamine supplementation for tolerance of intermittent exercise in soccer players

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    OBJECTIVE: To investigate whether supplementation of carbohydrate together with peptide glutamine would increase exercise tolerance in soccer players. METHODS: Nine male soccer players (mean age: 18.4 ± 1.1 years; body mass: 69.2 ± 4.6 kg; height: 175.5 ± 7.3 cm; and maximum oxygen consumption of 57.7 ± 4.8 ml.kg-1.min-1) were evaluated. All of them underwent a cardiopulmonary exercise test and followed a protocol that simulated the movements of a soccer game in order to evaluate their tolerance to intermittent exercise. By means of a draw, either carbohydrate with peptide glutamine (CARBOGLUT: 50g of maltodextrin + 3.5g of peptide glutamine in 250 ml of water) or carbohydrate alone (CARBO: 50g of maltodextrin in 250 ml of water) was administered in order to investigate the enhancement of the soccer players' performances. The solution was given thirty minutes before beginning the test, which was performed twice with a one-week interval between tests. RESULTS: A great improvement in the time and distance covered was observed when the athletes consumed the CARBOGLUT mixture. Total distance covered was 12750 ± 4037m when using CARBO, and 15571 ± 4184m when using CARBOGLUT (

    Maximal oxygen uptake of male professional soccer players, 2012-2015, at the end of four preseasons training

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    Purpose: We hypothesized that the aerobic capacity of soccer players was well developed and maintained during the competitive season and that a short rest period in the off-season would not be sufficient to significantly affect V̇O2max in these players. Methods: A total of 211 soccer athletes (age range, 17-34 years) being 71 professional juniors and 113 professional adults were compared with a control group of 27 non-professionals soccer players. All players performed cardiopulmonary exercise testing on a treadmill.Results: The results showed that a large number of soccer players had  V̇O2max levels incompatible with the status of professional athletes in this sport. The results between the players were: The player’s juniors presented average V̇O2max (56.2 mL.min-1.kg-1) significantly higher (P < 0.05) of that the professional players (53.3 mL.min-1.kg-1) and controls  (amateur, 50.4 mL.min-1.kg-1). However, a large number of the adult (67%) and juniors  (42%) professionals players presented values of V̇O2max near to the values covered for the control group.Conclusions:  The study verified a great number of soccer players, considered of the elite, with values below that it is recommended for players of this competitive level. It seems that preseason training was not enough to achieve compatible V̇O2max levels for most players

    Monitoring implantable immunoisolation devices with intrinsic fluorescence of genipin

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149252/1/jbio201800170.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149252/2/jbio201800170_am.pd

    Una nueva metaheurística aplicada al problema de ruteo de vehículos capacitados (cvrp) para la distribución de productos perecederos

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    La distribución representa un gran desafío para las empresas de alimentos perecederos que buscan satisfacer a sus clientes en términos de una calidad cambiante a lo largo de la cadena de suministro. En este contexto, en el siguiente articulo presentamos un nuevo modelo matemático para la distribución de productos perecederos que tiene como objetivo minimizar el tiempo total de viaje y las tardanzas en la entrega de los productos transportados. Con el objetivo de enfrentar este problema complejo, empleamos un algoritmo genético (GA) y una nueva metaheurística hibrida (N2) que combina operadores de tres distintos algoritmos para resolver cinco instancias de 25 clientes adaptadas de la literatura. Los resultados permiten comprobar la funcionalidad del modelo y muestran que el nuevo algoritmo es capaz de obtener mejores resultados en comparación con el algoritmo evolutivo, lo que brinda a los tomadores de decisiones una buena herramienta para la planeación de rutas de este tipo de productos

    The Prevalence of Latent Mycobacterium Tuberculosis Infection Based on an Interferon-γ Release Assay: A Cross-Sectional Survey Among Urban Adults in Mwanza, Tanzania.

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    One third of the world's population is estimated to be latently infected with Mycobacterium tuberculosis (LTBI). Surveys of LTBI are rarely performed in resource poor TB high endemic countries like Tanzania although low-income countries harbor the largest burden of the worlds LTBI. The primary objective was to estimate the prevalence of LTBI in household contacts of pulmonary TB cases and a group of apparently healthy neighborhood controls in an urban setting of such a country. Secondly we assessed potential impact of LTBI on inflammation by quantitating circulating levels of an acute phase reactant: alpha-1-acid glycoprotein (AGP) in neighborhood controls. The study was nested within the framework of two nutrition studies among TB patients in Mwanza, Tanzania. Household contacts- and neighborhood controls were invited to participate. The study involved a questionnaire, BMI determination and blood samples to measure AGP, HIV testing and a Quantiferon Gold In tube (QFN-IT) test to detect signs of LTBI. 245 household contacts and 192 neighborhood controls had available QFN-IT data. Among household contacts, the proportion of QFT-IT positive was 59% compared to 41% in the neighborhood controls (p = 0.001). In a linear regression model adjusted for sex, age, CD4 and HIV, a QFT-IT positive test was associated with a 10% higher level of alpha-1-acid glycoprotein(AGP) (10(B) 1.10, 95% CI 1.01; 1.20, p = 0.03), compared to individuals with a QFT-IT negative test. LTBI is highly prevalent among apparently healthy urban Tanzanians even without known exposure to TB in the household. LTBI was found to be associated with elevated levels of AGP. The implications of this observation merit further studies
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