Investing in Young Children : An Early Childhood Development Guide for Policy Dialogue and Project Preparation

Investing in young children is the responsible thing to do. All children deserve a chance to grow into healthy, educated, and competent people, no matter where and when they were born. While parents bear most of the responsibility for raising their children, especially in the early years of life, governments also have an important role during this critical time of human capital accumulation. For example, governments can ensure that all expectant mothers and young children have access to quality health services and nutrition. They can support parents and other caregivers in providing a positive and stimulating environment for children from birth on by promoting parenting information programs, investing in direct services such as home-based visits, funding daycare centers and preschools, or providing financial incentives to access good quality programs for infants and children. This Early Childhood Development (ECD) guide presents lessons and experiences that have been useful in informing the policy debate about ECD interventions and the design of such programs across the world. Whether the user of this guide is at the initial stage of deciding whether to expand an ECD portfolio or already in the program design stage, the content offers a range of evidence- based options to inform policy and investment choices

\u3ci\u3eDrosophila\u3c/i\u3e Muller F Elements Maintain a Distinct Set of Genomic Properties Over 40 Million Years of Evolution

The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25–50%) than euchromatic reference regions (3–11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11–27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4–3.6 vs. 8.4–8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu