School Absenteeism through the Transition to Kindergarten

ABSTRACT

Using nationally representative data from the Family and Child Experiences Survey 2009 Cohort (n = 2,798), this study examined patterns of absenteeism and their consequences through the transition to kindergarten. Overall, children were less likely to be absent in kindergarten than from Head Start at ages 3 and 4. Absenteeism was fairly stable across these early years, but children who experienced two years of Head Start were less likely to be absent in kindergarten than their classmates who only attended the program for one year. Ultimately, absenteeism at both ages 3 and 4 was associated with lower math and literacy achievement. However, children who experienced two years of Head Start and were more frequently absent demonstrated greater language development through the end of kindergarten as compared with children who only attended the program for one year. Policy implications are discussed in light of the complexity of early childhood education attendance in the United States.     

Classroom age composition and the early learning of preschoolers

Data from 1,407 preschoolers were used to examine the implications of classroom age composition for the early learning and development of 4-year-olds in classrooms with 3- and 5-year-olds also in attendance. Results suggest that a greater number of younger classmates did not detract from 4-year-olds’ language development, literacy performance, or inhibitory control, nor did having older peers consistently facilitate learning in these domains. However, 4-year-olds who entered school with low inhibitory control and print knowledge demonstrated greater gains in both domains when attending classrooms with more same-age or older classmates than when in classrooms with more younger peers. When taken together, these results suggest that classroom age composition, in prekindergarten programs serving mostly 4-year-olds, for the most part has little consequence except for those 4-year-olds entering school with lower skill levels in key domains, in which case having older peers is of benefit.     

Absenteeism in Head Start and Children's Academic Learning

Using nationally representative data from the Family and Child Experiences Survey 2009 cohort (n = 2,842), this study examined the implications of 3‐ and 4‐year‐old's absences from Head Start for their early academic learning. The findings from this study revealed that children who missed more days of school, and especially those who were chronically absent, demonstrated fewer gains in areas of math and literacy during the preschool year. Moreover, excessive absenteeism was found to detract from the potential benefits of quality preschool education and was especially problematic for the early learning of children who entered the Head Start program with a less developed skill set. Implications for policy and practice are discussed.     

Limitations of autopilot design for controlling a statically unstable flexible interceptor

The Mach number, angle of attack and altitude of operation for an interceptor vary widely during the course of its trajectory. As a result, the interceptor Center of Pressure (CP) locations move significantly around a given Center of Gravity (CG) location at these operating conditions. This results in an inevitable variation in aerodynamic static stability leading to stable and unstable operating regions. In order to ensure good speed of response during the interceptor homing phase, lesser static stability is desirable. Hence the requirement to handle aerodynamic instability at some other operating conditions in the interceptor envelope become inevitable. Since flexibility has a strong bearing on autopilot design, it becomes necessary to control unstable operating points in the presence of flexibility modes. Despite the static stability variation, aerodynamic design can control the level of maximum instability of the configuration. Hence the maximum static instability the autopilot can handle has to be specified for aerodynamic configuration design. This paper brings out the limitations of autopilot design in controlling an unstable interceptor with low bending mode frequencies in terms of maximum instability the autopilot design can handle, which serves as an important input for aerodynamic design.     

The Grade-Level and Cumulative Outcomes of Absenteeism

Nationally representative data from the Early Childhood Longitudinal Study Kindergarten Class of 2011 (n = 14,370) were used to examine the grade-level and cumulative outcomes of school absenteeism between kindergarten and fifth grade for students’ school performance in the United States. Students who were more frequently absent in any year of elementary school demonstrated lower academic, executive function, and socioemotional outcomes. Although there was little variation in the magnitude of associations across grade levels, there was evidence of cumulative associations. Specifically, students who were consistently absent throughout elementary school tended to have lower outcomes across developmental domains in the long-term. The negative links between absenteeism and outcomes were larger for Black than White students, but few other subgroup differences emerged.     

Cardioprotective response to chronic administration of vitamin E in isoproterenol induced myocardial necrosis: Hemodynamic,biochemical and ultrastructural studies

The present study evaluated the cardioprotective potential of vitamin-E by studying its effect on hemodynamic parameters, lipid peroxidation, myocyte injury marker and ultrastructural changes in model of isoproterenol-induced myocardial necrosis in rats. Wistar albino male rats (150–200 g) were randomly divided into saline, ISP control, and vit E groups. Vitamin E group was administered vitamin E at a dose of 100mg/kg/day while saline and ISP control groups received saline orally for one month. On 29^th and 30^th day, ISP (85 mg/kg, sc) was administered at an interval of 24 h to vit E and ISP control rats. On 31^st day, rats of all groups were anesthetized and hemodynamic parameters were recorded. At the end of experimentation, animals were sacrificed; hearts were excised and processed for biochemical and ultrastructural studies. ISP administration produced marked cardiac necrosis as evidenced by significant decrease in my ocardial creatine kinase-MB as well as increase in malonaldialdehyde levels. ISP-induced myocardial necrosis resulted in myocardial dysfunction as evidenced by significant depression in heart rate and mean arterial pressure in the ISP control group as compared to saline control. Salient ultrastructural changes including extensive loss of myofibrils, muscle necrosis, loss of mitochondria, and formation of several intracytoplasmic vacuoles and lipid droplets further confirmed the ISP-induced myocardial damage. However, subsequent to ISP challenge, vit E treatment significantly preserved the myocardium by restoring myocardial CK-MB activity, inhibiting the ISP-induced lipid peroxidation and ultrastructural changes. Additionally, pre-and co-treatment of vit E prevented the deleterious ultrastructural changes caused by ISP. These beneficial effects of chronic vit E treatment also translated into significant restoration of the altered hemodynamic parameters. The present study clearly demonstrated the cardioprotective potential of vit E at dose of 100 mg/kg in ISP-induced model of myocardial necrosis in rats. The significant restoration of altered hemodynamic parameters, myocardial CK-MB activity, prevention of ISP-induced rise in lipid peroxidation and ultrastructural changes may confirm its cardioprotective effect.     

AGC of two-area electric power systems using optimized fuzzy PID with filter plus double integral controller

The incessant swell in size, complexity, nonlinearity and structural variations in modern electric power systems, as well as rise in power demand has entailed the use of intelligent control strategies for the real-time satisfactory operation of power system. Hence, in this paper, a novel fuzzy PID with filter plus double integral (FPIDF-II) controller is proposed for automatic generation control (AGC) of two-area interconnected power systems. Initially, a well accepted two-area non-reheat thermal system is considered and the output scaling factors (SF) of FPIDF-II controller are optimized using imperialist competitive algorithm (ICA) employing an integral squared error (ISE) criterion. The supremacy of the proposed approach is demonstrated by contrasting the results with recently published optimal and various modern heuristic optimization techniques based controllers. To demonstrate the efficacy and scalability of the approach over other prevalent intelligent control techniques, the study is further extended to two-area non-reheat thermal system with governor deadband nonlinearity, two-area reheat thermal system, recently appeared two-area photovoltaic (PV)-reheat thermal system and two-area multi-source hydrothermal system. Finally, a sensitivity analysis is carried out to demonstrate the robustness of the proposed controller under broad variations in the system parameters from their nominal values.