95 research outputs found
Guidelines for Selecting Professional Development for Early Childhood Teachers
Engaging teachers of young children in effective in-service professional development is a critical component of establishing high quality early childhood education. However, not all professional development offerings are effective in imparting new knowledge, enhancing teacher practice, or improving child outcomes, making it difficult for teachers and directors to select professional development that will benefit their centers. This paper critically reviews the research literature on professional development for early childhood education to identify what features of professional development make a difference for teacher interactions and children’s learning and development. Guidance is provided for selecting professional development opportunities which meet the needs of children and teachers. Recommendations for how to create an ongoing professional development program within an early childhood center by creating a professional learning community are also made. Such an approach supports the center to become a place that values learning and continued education for all professionals
Beyond the Pencil: Expanding the Occupational Therapists’ Role in Helping Young Children to Develop Writing Skills
Occupational therapists (OTs) play an important role in early childhood classrooms as vital members of the educational team, particularly for young children’s writing development. Children’s emergent writing is a foundational literacy skill, which begins to develop well before they enter elementary school. However, early childhood classrooms are lacking in supports for early writing development. OTs are experts in guiding the development of early writing skills in young children and, therefore, should be considered as critical members of the early literacy curriculum team. This paper identifies the critical role emergent writing plays in early childhood literacy development and how to effectively assess young children’s writing ability. Practical guidance is provided to identify specific ways that OTs can merge their occupation-centered approach with their expertise in writing to serve as a key resource for classroom teachers and enhance the writing development of all children. Specific strategies are included for encouraging OTs to expand their approaches to writing beyond handwriting
Self healing slip pulses along a gel/glass interface
We present an experimental evidence of self-healing shear cracks at a
gel/glass interface. This system exhibits two dynamical regimes depending on
the driving velocity : steady sliding at high velocity (> Vc = 100-125 \mu
m/s), caracterized by a shear-thinning rheology, and periodic stick-slip
dynamics at low velocity. In this last regime, slip occurs by propagation of
pulses that restick via a ``healing instability'' occuring when the local
sliding velocity reaches the macroscopic transition velocity Vc. At driving
velocities close below Vc, the system exhibits complex spatio-temporal
behavior.Comment: 4 pages, 6 figure
Does the continuum theory of dynamic fracture work?
We investigate the validity of the Linear Elastic Fracture Mechanics approach
to dynamic fracture. We first test the predictions in a lattice simulation,
using a formula of Eshelby for the time-dependent Stress Intensity Factor.
Excellent agreement with the theory is found. We then use the same method to
analyze the experiment of Sharon and Fineberg. The data here is not consistent
with the theoretical expectation.Comment: 4 page
Impacto de la variabilidad genotÃpica y ambiental sobre los carbohidratos solubles en el grano de soja
Optimizar la fecha de siembra del cultivo resulta crÃtico para maximizar el rendimiento (Di Mauro et al., 2018). Sin embargo, sus efectos sobre la calidad de los granos, más allá de la concentración de proteÃna y aceite, han sido raramente descriptos (Bosaz et al., 2019).A los efectos prácticos, el grano de soja está compuesto por: proteÃna, aceite y residual. El residual contiene cenizas, carbohidratos solubles (azúcares y oligosacáridos) e insolubles (celulosa y hemicelulosa) y lignina. Estos últimos son los componentes mayoritarios de la fibra dietaria (Westgate, 1999). La proteÃna y el aceite son los componentes de mayor valor económico y nutricional, representando en conjunto el 60% del peso del grano expresado en base seca, las cenizas corresponden a un 5% aproximadamente, mientras que un 35% pertenece a carbohidratos. Estos últimos se encuentran principalmente en la cubierta, pero también se pueden encontrar en las células del parénquima del embrión. Una porción de carbohidratos y lignina se elimina con las cascarillas, pero la harina de soja puede todavÃa contener hasta un 40% de carbohidratos totales (Medic et al., 2014). El residual es la fracción menos estudiada del grano de soja por ser el componente de menor retribución monetaria y calidad nutricional (Middelbos y Fahey, 2008). Sin embargo, su concentración y composición puede afectar el rendimiento y calidad de los ingredientes proteicos derivados. El residual, contiene rafinosa y estaquiosa, dos galactooligosacáridos de tres y cuatro monómeros respectivamente, con efectos antinutricionales. Estos oligosacáridos producen una disminución en la absorción intestinal de nutrientes, flatulencias y diarrea en cerdos, perros y humanos (Kumar et al., 2010). Genotipos con baja concentración de estaquiosa y elevada concentración de sacarosa han sido desarrollados para evitar dichas caracterÃsticas. Su utilización en la elaboración de ingredientes proteicos ha conducido a una disminución en la concentración de estaquiosa en los mismos, aumentando la eficiencia del proceso y generando propiedades funcionales únicas (Deak y Johnson, 2006).El objetivo de este estudio consistió en describir cómo los genotipos (G) y el ambiente (A) afectan a la proteÃna, el aceite y los carbohidratos solubles (estaquiosa, rafinosa, glucosa y fructosa) dentro de la fracción residual en el grano de soja.Fil: Lopez, E.. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Alvarez Prado, Santiago. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de AgronomÃa. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Rotundo, José Luis. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentina. Corteva Agriscience; Estados UnidosFil: Gerde, Jose Arnaldo. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentin
Nonlinear stability of oscillatory wave fronts in chains of coupled oscillators
We present a stability theory for kink propagation in chains of coupled
oscillators and a new algorithm for the numerical study of kink dynamics. The
numerical solutions are computed using an equivalent integral equation instead
of a system of differential equations. This avoids uncertainty about the impact
of artificial boundary conditions and discretization in time. Stability results
also follow from the integral version. Stable kinks have a monotone leading
edge and move with a velocity larger than a critical value which depends on the
damping strength.Comment: 11 figure
Microalgae Lipid Characterization
To meet the growing interest of utilizing microalgae biomass in the production of biofuels and nutraceutical and pharmaceutical lipids, we need suitable analytical methods and a comprehensive database for their lipid components. The objective of the present work was to demonstrate methodology and provide data on fatty acid composition, lipid class content and composition, characteristics of the unsaponifiables, and type of chlorophylls of five microalgae. Microalgae lipids were fractionated into TAG, FFA, and polar lipids using TLC, and the composition of fatty acids in total lipids and in each lipid class, hydrocarbons, and sterols were determined by GC-MS. Glyco- and phospholipids were profiled by LC/ESI-MS. Chlorophylls and their related metabolites were qualified by LC/APCI-MS. The melting and crystallization profiles of microalgae total lipids and their esters were analyzed by DSC to evaluate their potential biofuel applications. Significant differences and complexities of lipid composition among the algae tested were observed. The compositional information is valuable for strain selection, downstream biomass fractionation, and utilization
A comparison of drug transport in pulmonary absorption models: isolated perfused rat lungs, respiratory epithelial cell lines and primary cell culture
Purpose: To evaluate the ability of human airway epithelial
cell layers and a simple rat isolated perfused lung (IPL) model to predict pulmonary drug absorption in rats in vivo.
Method: The permeability of seven compounds selected to
possess a range of lipophilicity was measured in two airway
cell lines (Calu-3 and 16HBE14o-), in normal human bronchial
epithelial (NHBE) cells and using a simple isolated perfused
lungs (IPL) technique. Data from the cell layers and
ex vivo lungs were compared to published absorption rates
from rat lungs measured in vivo.
Results: A strong relationship was observed between the logarithm of the in vivo absorption half-life and the absorption half-life in the IPL (r = 0.97; excluding formoterol). Good log-linear relationships were also found between the apparent first-order absorption rate in vivo and cell layer permeability with correlation coefficients of 0.92, 0.93, 0.91 in Calu-3, 16HBE14o- and NHBE cells, respectively.
Conclusion: The simple IPL technique provided a good prediction of drug absorption from the lungs, making it a useful method for empirical screening of drug absorption in the lungs. Permeability measurements were similar in all the respiratory epithelial cell models evaluated, with Calu-3 having the advantage for routine permeability screening purposes of being readily availability, robust and easy to culture
Collective effects at frictional interfaces
We discuss the role of the long-range elastic interaction between the
contacts inside an inhomogeneous frictional interface. The interaction produces
a characteristic elastic correlation length (where
is the distance between the contacts, is the elastic constant of a
contact, and is the Young modulus of the sliding body), below which the
slider may be considered as a rigid body. The strong inter-contact interaction
leads to a narrowing of the effective threshold distribution for contact
breaking and enhances the chances for an elastic instability to appear. Above
the correlation length, , the interaction leads to screening of
local perturbations in the interface, or to appearance of collective modes ---
frictional cracks propagating as solitary waves
- …