920 research outputs found

    Missing & Murdered Indigenous People

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    A Professional Development Model to Promote Internet Integration in P-12 Teaching Practices

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    This mixed-methods study examined effects of a staff development model on instructional practices and dispositions of P-12 teachers. The model design was guided by participants’ varying developmental levels and their values and beliefs about teaching and learning. The study adds to our understanding of the need for teacher-centered professional development

    The Impact of Brief Animal Assisted Therapy Dog Interactions on College Student Stress and Self-Efficacy Levels

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    The aim of the current study was to examine the potential benefits of dog therapy programs on student stress levels on a college campus. While these programs have become increasingly popular there is little evidence on the effectiveness of animal centered activities. We compared the differences on three types of assessments related to stress levels (e.g., Self-Efficacy Scale, Perceived Stress Scale and relative changes in stress hormone levels (cortisol)) for college students before and after interacting with therapy dogs for 10 minutes. Saliva samples were collected using Salimetrics’ Salivabio Oral Swab (SOS) method from student participants 15 minutes after arrival at the study (baseline) and 15 minutes after interaction with therapy dogs (treatment). Saliva samples were processed for cortisol using Salimetrics’ High Sensitivity Salivary Cortisol ELISA kit. This data will provide insight on how interacting with therapy animals can affect stress levels

    Following Bimolecular Excited-State Proton Transfer between Hydroxycoumarin and Imidazole Derivatives

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    The ultrafast dynamics of a bimolecular excited-state proton transfer (ESPT) reaction between the photoacid 7-hydroxy-4-(trifluoromethyl)-1-coumarin (CouOH) and 1-methylimidazole (MI) base in aprotic chloroform-d1 solution were investigated using ultrafast transient infrared (TRIR) and transient absorption (TA) spectroscopies. The excited-state lifetime of the photoacid in solution is relatively short (52 ps), which at the millimolar photoacid and base concentrations used in our study precludes any diffusion-controlled bimolecular ESPT reactions. This allows the prompt ESPT reaction between hydrogen-bonded CouOH and MI molecules to be studied in isolation and the “contact” ESPT dynamics to be unambiguously determined. Our time-resolved studies reveal that ultrafast ESPT from the CouOH moiety to hydrogen-bonded MI molecules occurs within ∌1 ps, tracked by unequivocal spectroscopic signatures of CouO–* photoproducts that are formed in tandem with HMI+. Some of the ESPT photoproducts subsequently π-stack to form exciplexes on a ∌35 ps time scale, minimizing the attractive Coulombic forces between the oppositely charged aromatic molecules. For the concentrations of CouOH and MI used in our study (up to 8 mM), we saw no evidence for excited-state tautomerization of coumarin anions

    Thermodynamics of the classical spin-ice model with nearest neighbour interactions using the Wang-Landau algorithm

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    In this article we study the classical nearest-neighbour spin-ice model (nnSI) by means of Monte Carlo simulations, using the Wang-Landau algorithm. The nnSI describes several of the salient features of the spin-ice materials. Despite its simplicity it exhibits a remarkably rich behaviour. The model has been studied using a variety of techniques, thus it serves as an ideal benchmark to test the capabilities of the Wang Landau algorithm in magnetically frustrated systems. We study in detail the residual entropy of the nnSI and, by introducing an applied magnetic field in two different crystallographic directions ([111] and [100]), we explore the physics of the kagome-ice phase, the transition to full polarisation, and the three dimensional Kasteleyn transition. In the latter case, we discuss how additional constraints can be added to the Hamiltonian, by taking into account a selective choice of states in the partition function and, then, show how this choice leads to the realization of the ideal Kasteleyn transition in the system.Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicosFacultad de Ciencias Exacta

    High level triggers for explosive mafic volcanism: Albano Maar, Italy

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    Colli Albani is a quiescent caldera complex located within the Roman Magmatic Province (RMP), Italy. The recent Via dei Laghi phreatomagmatic eruptions led to the formation of nested maars. Albano Maar is the largest and has erupted seven times between ca 69-33ka. The highly explosive nature of the Albano Maar eruptions is at odds with the predominant relatively mafic (SiO2=48-52wt.%) foiditic (K2O=9wt.%) composition of the magma. The deposits have been previously interpreted as phreatomagmatic, however they contain large amounts (up to 30%vol) of deep seated xenoliths, skarns and all pre-volcanic subsurface units. All of the xenoliths have been excavated from depths of up to 6km, rather than being limited to the depth at which magma and water interaction is likely to have occurred, suggesting an alternative trigger for eruption. High precision geochemical glass and mineral data of fresh juvenile (magmatic) clasts from the small volume explosive deposits indicate that the magmas have evolved along one of two evolutionary paths towards foidite or phonolite. The foiditic melts record ca. 50% mixing between the most primitive magma and Ca-rich melt, late stage prior to eruption. A major result of our study is finding that the generation of Ca-rich melts via assimilation of limestone, may provide storage for significant amounts of CO2 that can be released during a mixing event with silicate magma. Differences in melt evolution are inferred as having been controlled by variations in storage conditions: residence time and magma volume. © 2013

    Rotavirus contamination of surface waters from the northwest of Argentina

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    Fecal pollution of water is a serious concern because it is associated with the transmission of pathogens. The aim of this study was to analyze the occurrence of group A rotavirus (RVA) in surface waters from the Arias–Arenales River in Salta, a northern city in Argentina, and to define possible sources of fecal viral pollution. A total of 116 water samples were analyzed and RVA was detected in 3.4% (95% CI: 0.1–7.0%), with concentrations ranging from 1.9 × 105 to 3.8 × 106 genome copies per liter. RVA strains were characterized as G1P[8], G4P[8] and G9P[8], which are common genotypes circulating in the local population. The Arias–Arenales River presented unusual and sporadic contamination by RVA, originated from stormwater discharges and a variety of non-identified sources, and support the essential need of viral indicators for enhanced monitoring of water quality.Fil: Prez, VerĂłnica Emilse. Universidad Nacional de CĂłrdoba. Facultad de Medicina. Instituto de VirologĂ­a Dr. J. M. Vanella; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba; ArgentinaFil: Poma, Hugo Ramiro. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Salta. Instituto de Investigaciones para la Industria QuĂ­mica. Universidad Nacional de Salta. Facultad de IngenierĂ­a. Instituto de Investigaciones para la Industria QuĂ­mica; ArgentinaFil: Giordano, Georgina Gisela. Universidad Nacional de CĂłrdoba. Facultad de Medicina. Instituto de VirologĂ­a Dr. J. M. Vanella; ArgentinaFil: Victoria, MatĂ­as. Universidad de la RepĂșblica. Centro Universitario del Litoral Norte. Centro Universitario de Salto; UruguayFil: Nates, Silvia Viviana. Universidad Nacional de CĂłrdoba. Facultad de Medicina. Instituto de VirologĂ­a Dr. J. M. Vanella; ArgentinaFil: Rajal, VerĂłnica Beatriz. Nanyang Technological University. Singapore Centre for Environmental Life Sciences Engineering; Singapur. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Salta. Instituto de Investigaciones para la Industria QuĂ­mica. Universidad Nacional de Salta. Facultad de IngenierĂ­a. Instituto de Investigaciones para la Industria QuĂ­mica; ArgentinaFil: Barril, Patricia Angelica. Centro de InvestigaciĂłn y Asistencia TĂ©cnica a la Industria; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Patagonia Confluencia; Argentin

    Reconciling complex stratigraphic frameworks reveals temporally and geographically variable depositional patterns of the Campanian Ignimbrite

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    The 39.8-ka Campanian Ignimbrite was emplaced during a large caldera-forming eruption of Campi Flegrei near Naples, Italy. The ignimbrite is found up to 80 km from the caldera, and co-ignimbrite ash-fall deposits occur 3200 km away. The proximal and distal stratigraphy of the Campanian Ignimbrite has not been definitively correlated due to the dissimilar appearance of the proximal and distal deposits, a lack of medial exposures, and the inconsistency and heterogeneity of the proximal stratigraphy. Here, we document the major-element glass-shard chemistry, matrix componentry, and lithic componentry of the proximal and distal stratigraphic sequences of the ignimbrite to attempt to correlate the units. The results of these disparate observations taken together suggest that the established stratigraphic units cannot be directly and uniquely correlated between the proximal and distal regions and that neither the proximal nor distal stratigraphy provides a record of the entire eruptive sequence. However, the characteristics studied can be used to demarcate eruptive phases that are connected to some of the defined units in the proximal and distal stratigraphy

    Thermodynamics of the classical spin-ice model with nearest neighbour interactions using the Wang-Landau algorithm

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    In this article we study the classical nearest-neighbour spin-ice model (nnSI) by means of Monte Carlo simulations, using the Wang-Landau algorithm. The nnSI describes several of the salient features of the spin-ice materials. Despite its simplicity it exhibits a remarkably rich behaviour. The model has been studied using a variety of techniques, thus it serves as an ideal benchmark to test the capabilities of the Wang Landau algorithm in magnetically frustrated systems. We study in detail the residual entropy of the nnSI and, by introducing an applied magnetic field in two different crystallographic directions ([111] and [100]), we explore the physics of the kagome-ice phase, the transition to full polarisation, and the three dimensional Kasteleyn transition. In the latter case, we discuss how additional constraints can be added to the Hamiltonian, by taking into account a selective choice of states in the partition function and, then, show how this choice leads to the realization of the ideal Kasteleyn transition in the system.Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicosFacultad de Ciencias Exacta
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