6,014 research outputs found
Extended early childhood intervention and school achievement: Age 13 findings from the Chicago longitudinal study
We evaluated the effects of participation in an extended program of compensatory education for a large sample of inner-city black children up to the seventh grade. The intervention is the Chicago Child-Parent Center and Expansion Program. Groups included 426 children who participated in the program from preschool to grades 2 or 3 and 133 school-stable children whose participation ceased in kindergarten. After taking into account initial differences in both the level and the growth rate of achievement, frequency of school mobility after the program, and sample selection bias, program participation for two or three years after preschool and kindergarten is positively associated with reading and math achievement in grade 7 and negatively associated with cumulative grade retention four years after the end of the program. Study findings provide rare longitudinal evidence from an established program concerning the effects of extending compensatory education into the primary grades.
Programmed schedule holds for improving launch vehicle holds
Baseline definition and system optimization are used for the analysis of programmed holds developed through prelaunch system analysis. Identification of design specifications for ground support equipment and maintenance concepts, and design specifications are used to describe the functional utilization of the overall flow process
Zonal rotor study of the subcellular distribution of acyl-CoA synthetases, carnitine acyl transferases and phosphatidate phosphatase in the guinea-pig small intestine.
Homogenates made from the mucosa of the guinea pig small intestine
were fractionated in a zonal rotor by rate and isopycnic centrifugation
in sucrose gradients. Density perturbation of endoplasmic reticulum
vesicles was done by treating homogenate with pyrophosphate and was
analysed by isopyenic centrifugation.
Subcellular fractions were analysed for the distribution of markers
for brush borders. basolateral plasma membrane. Iysosomes. peroxi.
somes. mitochondria. nuclei and endoplasmic reliculum. Fractions
werc also analysed for the distribution ofpropionyl-. butyryl-. and palmityl.
CoA synthetases. for carnitine acetyl and palmityltransferases.
and for phosphatidate phosphatase.
Comparison of marker and unknown distributions shows that palmityl-
CoA synthetase is located on the endoplasmic reticulum. while
propionyl- and butyryl-CoA synthetases and carnitine acetyl and pal.
mit)'l transferases are exclusively mitochondrial.
I'hosphatidate phosphatase has complex subcellular localisation
with activity in brush borders. microsomes (possibly not the endoplasmic
reticulum component) and possibly Iysosomes
Subcellular localization of monoglyceride acyltransferase, xanthine oxidation, NADP: isocitrate dehydrogenase and alkaline phosphatase in the mucosa of the guinea-pig small intestine.
1. Rate dependent and isopycnic banding in a zonal rotor were used to analyse the subcellular
sites of enzymes in homogenates of guinea-pig small intestinal mucosa.
2, The results demonstrate the following localizations: monoglyceride acyltransferase-microsomal;
xanthine oxidase and dehydrogenase-soluble phase, and NADP: isocitrate dehydrogenase-soluble
phase and mitochondrial.
3, Alkaline phosphatase is confined to brush borders and is absent from the basolateral plasma
membrane. A variable proportion of the activity, up to 40%, is on brush borders which during homogenization
break up into particles of reduced density and slow sedimentation rate
Calculation of Eddy Current Fields for Coils of Arbitrary Shape
In the design of an eddy current inspection device, it is useful to have available a means of visualizing the eddy current distribution produced in the material to be tested. This is evidenced by the widespread use of the early models of Dodd and Deeds [1], who provided analytic solutions for the field in a number of axisymmetric probe geometries. The analytic approach was later extended [2–4] to include a more general class of coils, and was applied to the case of a circular, air-core horizontal coil [4]
Intestinal peroxisomes of goldfish (Carrassius auratus) - examination for hydrolase, dehydrogenase and carnitine acetyltransferase activities.
1. Rate sedimentation and isopycnic centrifugation were used to analyse the subcellular
sites of enzymes in homogenates of goldfish intestinal mucosa.
2. The results allowed the following allocations to be made: carnitine acetyl transferase-mitochondrial
and peroxisomal, xanthine dehydrogenase and NAD: :x-glycerophosphate dehydrogenase soluble phase;
NADP: isocitrate dehydrogenase soluble phase and mitochondrial, and 2-naphthyl laurate hydrolase
microsomal and/or brush border.
3. Histochemistry confirmed the use of alkaline phosphatase and I-naphthyl acetate esterase as
brush border and microsome markers respectively.
4. Urate oxidase, allantoinase, allantoicase, xanthine oxidase and glycollatejlactate oxidase, activities
were undetectable, and I-naphthyl palmilale hydrolase was present only as a contaminant from pancreas
Cost-Effective Crime Prevention: Economic Analysis of the Chicago Child-Parent Centers Early Education Program
International Public Health Research Involving Interpreters: a Case Study from Bangladesh
Background: Cross-cultural and international research are important components of public health research, but the challenges of language barriers and working with interpreters are often overlooked, particularly in the case of qualitative research.
Methods: A case-study approach was used to explore experiences of working with an interpreter in Bangladesh as part of a research project investigating women's experiences of emergency obstetric care.
The case study: Data from the researcher's field notes provided evidence of experiences in working with an interpreter and show how the model of interviewing was adapted over time to give a more active role to the interpreter. The advantages of a more active role were increased rapport and "flow" in interviews. The disadvantages included reduced control from the researcher's perspective. Some tensions between the researcher and interpreter remained hard to overcome,
irrespective of the model used. Independent transcription and translation of the interviews also raised questions around accuracy in translation.
Conclusion: The issues examined in this case study have broader implications for public health research. Further work is needed in three areas: 1) developing effective relationships with interpreters; 2) the impact of the interpreter on the research process; and 3) the accuracy of the translation and level of analysis needed in any specific public health research. Finally, this paper highlights the importance to authors of reflecting on the potential impact of translation and interpretation on the research process when disseminating their research
Hyperbolic Balance Laws with a Non Local Source
This paper is devoted to hyperbolic systems of balance laws with non local
source terms. The existence, uniqueness and Lipschitz dependence proved here
comprise previous results in the literature and can be applied to physical
models, such as Euler system for a radiating gas and Rosenau regularization of
the Chapman-Enskog expansion.Comment: 26 page
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