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High-quality early care and education (ECE) programs promote positive child outcomes, allow parents to work, and contribute to the local economy. Although extant research takes into account the ECE sector in its entirety, recent economic and policy interest has centered on part-day prekindergarten for 3- and 4-year-olds only. Using an ecological framework, we review and synthesize the research literature to examine whether the emphasis on pre-k is justified as economically superior to a comprehensive approach. We compare impacts on the macrosystem (regional economy), exosystem (parents), and microsystem (children's long-term human development) and argue that a holistic approach that includes comprehensive ECE services has economic returns as great as or greater than pre-k alone. Finally, we explore the conceptual barriers that have contributed to the narrow focus on pre-k and the policy implications of ignoring the broader ecological context. 相似文献
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Thomas Horn Brian D. Warner Joyce A. Running Kristi Downing Jennifer Clyne Mickey S. Urdea 《Nucleosides, nucleotides & nucleic acids》2013,32(5-6):875-877
Abstract Branched oligonucleotides have been synthesized using phosphoramidite derivatives with two protected hydroxyl functions. These molecules are employed for a label amplification strategy used in DNA probe diagnostics. 相似文献
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Lauren B.A. Woodruff Brian L. May Joseph R. Warner Ryan T. Gill 《Biotechnology and bioengineering》2013,110(5):1520-1526
In the genome‐engineering era, it is increasingly important that researchers have access to a common set of platform strains that can serve as debugged production chassis and the basis for applying new metabolic engineering strategies for modeling and characterizing flux, engineering complex traits, and optimizing overall performance. Here, we describe such a platform strain of E. coli engineered for ethanol production. Starting with a fully characterized host strain (BW25113), we site‐specifically integrated the genes required for homoethanol production under the control of a strong inducible promoter into the genome and deleted the genes encoding four enzymes from competing pathways. This strain is capable of producing >30 g/L of ethanol in minimal media with <2 g/L produced of any fermentative byproduct. Using this platform strain, we tested previously identified ethanol tolerance genes and found that while tolerance was improved under certain conditions, any effect on ethanol production or tolerance was lost when grown under production conditions. Thus, our findings reinforce the need for a metabolic engineering “commons” that could provide a set of platform strains for use in more sophisticated genome‐engineering strategies. Towards this end, we have made this production strain available to the scientific community. Biotechnol. Bioeng. 2013; 110: 1520–1526. © 2013 Wiley Periodicals, Inc. 相似文献
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Thais R. Peclat Katie L. Thompson Gina M. Warner Claudia C.S. Chini Mariana
G. Tarrag Delaram Z. Mazdeh Chunlian Zhang Jose ZavalaSolorio Ganesh Kolumam Yao Liang Wong Robert L. Cohen Eduardo N. Chini 《Aging cell》2022,21(4)
Nicotinamide adenine dinucleotide (NAD) levels decline during aging, contributing to physical and metabolic dysfunction. The NADase CD38 plays a key role in age‐related NAD decline. Whether the inhibition of CD38 increases lifespan is not known. Here, we show that the CD38 inhibitor 78c increases lifespan and healthspan of naturally aged mice. In addition to a 10% increase in median survival, 78c improved exercise performance, endurance, and metabolic function in mice. The effects of 78c were different between sexes. Our study is the first to investigate the effect of CD38 inhibition in naturally aged animals. 相似文献
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A marked decrease in the amount of the A2 component of phenol oxidase occurs in the speck locus of Drosophila melanogaster. The amount of A2 in speck is restored to a normal amount in the presence of the suppressor mutant, su(s) 2. 相似文献
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Effects of Polyploidy on Photosynthetic Rates, Photosynthetic Enzymes, Contents of DNA, Chlorophyll, and Sizes and Numbers of Photosynthetic Cells in the C(4) Dicot Atriplex confertifolia 下载免费PDF全文
Photosynthetic rates, chlorophyll content, and activities of several photosynthetic enzymes were determined per cell, per unit DNA, and per unit leaf area in five ploidal levels of the C4 dicot Atriplex confertifolia. Volumes of bundle sheath and mesophyll protoplasts were measured in enzymatic digestions of leaf tissue. Photosynthetic rates per cell, contents of DNA per cell, and activities of the bundle sheath enzymes ribulose 1,5-bisphosphate carboxylase (RuBPC) and NAD-malic enzyme per cell were correlated with ploidal level at 99% or 95% confidence levels, and the results suggested a near proportional relationship between gene dosage and gene products. There was also a high correlation between volume of mesophyll and bundle sheath cells and the ploidal level. Contents of DNA per cell, activity of RuBPC per cell, and volumes of cells were correlated with photosynthetic rate per cell at the 95% confidence level. The mesophyll cells did not respond to changes in ploidy like the bundle sheath cells. In the mesophyll cells the chlorophyll content per cell was constant at different ploidal levels, there was less increase in cell volume than in bundle sheath cells with an increase in ploidy, and there was not a significant correlation (at 95% level) of phosphoenolpyruvate carboxylase activity or content and pyruvate,Pi dikinase activity with increase in ploidy. The number of photosynthetic cells per unit leaf area progressively decreased with increasing ploidy from diploid to hexaploid, but thereafter remained constant in octaploid and decaploid plants. Numbers of cells per leaf area were not correlated with cell volumes. The mean photosynthetic rates per unit leaf area were lowest in the diploid, similar in 4×, 6×, and 8×, and highest in the decaploid. The photosynthetic rate per leaf area was highly correlated with the DNA content per leaf area. 相似文献