Non-parental caregivers, parents, and the school readiness of the children of Latino/a immigrants

School readiness generally predicts trajectories of academic achievement over time, motivating efforts to support the development of school readiness skills by expanding access to and improving the quality of early childhood care and education. One dimension of early childhood care and education concerns the beliefs that non-parental caregivers (e.g. preschool teachers, relatives, child care providers) in these settings have about school readiness and how these beliefs may differ from parent beliefs. Non-parental caregivers’ beliefs—and their alignment with parents’ beliefs—may be especially significant for certain segments of the child population, namely children of Latino/a immigrant parents in the U.S., who are overrepresented among students who enter school with underdeveloped academic skills and whose parents may not have the resources nor the familiarity with the U.S. education system to know what schools will expect of their children upon school entry. Latino/a immigrant parents and their children, therefore, may be more influenced by the school readiness beliefs of non-parental caregivers than other groups. This study uses the Early Childhood Longitudinal Survey-Birth Cohort (ECLS-B) to investigate whether non-parental early caregivers’ beliefs about school readiness and their alignment with parental beliefs are associated with children’s achievement test scores at kindergarten entry—in general and especially among the children of Latino/a immigrant parents.Sociolog

Fundamental approach to laminar flame propagation

The complete system of equations for a theory of laminar flame equations is presented, taking into account both heat conduction and diffusion, for the case of an arbitrary number of simultaneous reactions. The eigenvalue problem determining the flame velocity is formulated. Two examples are given in order to show that explicit analytical expressions for the flame velocity can be obtained, which are in good agreement with the results obtained by numerical integration of the equations. In the first example (hydrazine decomposition) one reaction is considered as global, i.e., rate-controlling, reaction. In the second example (ozone decomposition) a hypothesis is introduced for the concentration of the free radical O, which corresponds to the steady-state approximation generally used in classical chemical kinetics. In both cases approximate explicit formulae are obtained for the flame velocity using legitimate approximation methods, without making drastic assumptions. The steady-state assumption used for the ozone flame has a bearing on a better understanding of the mechanism of chain reactions in general. The method indicated in the paper gives hope that the more complicated chain reactions, such as the combustion of hydrocarbons, will also be made accessible to theoretical computation

The thermal theory of constant-pressure deflagration for first-order global reactions

The one-dimensional thermal theory of constant-pressure deflagration has been discussed in a recent publication by the senior author and G. Millán. In this paper an explicit relation was given for the linear burning velocity in flames supported by first-order global reactions. It is the purpose of the present analysis to extend this work by dropping the assumptions (a) that the average molecular weight of the gas mixture remains constant, and (b) that the thermal conductivity is constant. As the result, the one-dimensional theory of constant-pressure deflagration described in this paper is complete except in so far as the following reasonable approximations are concerned: (a) a constant average specific heat equal to the ratio of heat release per gram of reactant to total temperature rise may be used; (b) the ideal gas law constitutes a satisfactory equation of state for reacting gas mixtures