Preserving, Protecting, and Expanding Affordable Housing: A Policy Toolkit for Public Health

Resurgent interest in urban living is helping to revive neighborhoods in numerous American cities, stabilizing populations and sometimes beginning to reverse previous declines. One consequence of the influx of residents is new public and private investment in amenities such as parks, bike paths and grocery and other stores. However, new demand and investment can also drive up housing costs. That's particularly true in areas that have traditionally been affordable to low- and moderate-income individuals and families, notes a report by ChangeLab Solutions. With support from Kresge's Health Program, the nonprofit ChangeLab Solutions developed a guide to help practitioners and community advocates preserve and expand the number of affordable rental housing options in high-demand neighborhoods. The guide is aimed at practitioners who work at the intersection of housing and health, an area of increasing emphasis for Kresge's Health Program.The ChangeLab team has produced a policy toolkit with information on housing market trends and research on the links between rising housing costs and poor health outcomes. The toolkit identifies strategies to help ensure that households of all incomes have housing options in the areas where they want to live. It covers six policy areas: preservation, protection, inclusion, revenue generation, incentives and property acquisition

Near-field angular distributions of high velocity ions for low-power hall thrusters

Experimental angular distributions of high-energy primary ions in the near-field region of a small Hall thruster between 50-200 mm downstream of the thruster exit plane at a range of centerline angles have been determined using a highly-collimated, energy-selective diagnostic probe. The measurements reveal a wide angular distribution of ions exiting the thruster channel and the formation of a strong, axially-directed jet of ions along the thruster centerline. Comparisons are made to other experimental determinations as applicable

The Theory of Pseudoknots

Classical knots in $\mathbb{R}^3$ can be represented by diagrams in the plane. These diagrams are formed by curves with a finite number of transverse crossings, where each crossing is decorated to indicate which strand of the knot passes over at that point. A pseudodiagram is a knot diagram that may be missing crossing information at some of its crossings. At these crossings, it is undetermined which strand passes over. Pseudodiagrams were first introduced by Ryo Hanaki in 2010. Here, we introduce the notion of a pseudoknot, i.e. an equivalence class of pseudodiagrams under an appropriate choice of Reidemeister moves. In order to begin a classification of pseudoknots, we introduce the concept of a weighted resolution set, an invariant of pseudoknots. We compute the weighted resolution set for several pseudoknot families and discuss notions of crossing number, homotopy, and chirality for pseudoknots.Comment: 15 pages, 14 figures. In v.2, we corrected an error in Figure 2 of v.

Identifying Struggling Readers in Middle School with ORF, Maze and Prior Year Assessment Data

Response to Intervention (RTI) is a framework with the primary purpose of early identification and prevention of learning problems. Screening procedures identify students in need of targeted intervention, but current screening research is limited to the elementary grades. This study explored the use of screening measures: prior year assessment data, oral reading fluency (ORF), and maze, to predict performance on Georgia’s Criterion-Referenced Competency Test (CRCT-8) for 236 eighth grade students from one district in Georgia. Logistic regression analyses compared the accuracy of the predictor variables. Overall classification accuracy was 96.6% for ORF and maze and 97.1% for CRCT-7; however, this was primarily due to the low base rate of poor performance on the CRCT-8 in the sample. A combination of screens did not significantly improve classification accuracy. A screening process that used CRCT-7 data followed by fall ORF resulted in 100% sensitivity and 90% specificity. Implications for practice are discussed

Push-Pull Control of Motor Output

Inhibition usually decreases input–output excitability of neurons. If, however, inhibition is coupled to excitation in a push–pull fashion, where inhibition decreases as excitation increases, neuron excitability can be increased. Although the presence of push–pull organization has been demonstrated in single cells, its functional impact on neural processing depends on its effect on the system level. We studied push–pull in the motor output stage of the feline spinal cord, a system that allows independent control of inhibitory and excitatory components. Push–pull organization was clearly present in ankle extensor motoneurons, producing increased peak-to-peak modulation of synaptic currents. The effect at the system level was equally strong. Independent control of the inhibitory component showed that the stronger the background of inhibition, the greater the peak force production. This illustrates the paradox at the heart of push–pull organization: increased force output can be achieved by increasing background inhibition to provide greater disinhibition

A nucleotide resolution map of Top2-linked DNA breaks in the yeast and human genome

DNA topoisomerases are required to resolve DNA topological stress. Despite this essential role, abortive topoisomerase activity generates aberrant protein-linked DNA breaks, jeopardising genome stability. Here, to understand the genomic distribution and mechanisms underpinning topoisomerase-induced DNA breaks, we map Top2 DNA cleavage with strand-specific nucleotide resolution across the S. cerevisiae and human genomes—and use the meiotic Spo11 protein to validate the broad applicability of this method to explore the role of diverse topoisomerase family members. Our data characterises Mre11-dependent repair in yeast and defines two strikingly different fractions of Top2 activity in humans: tightly localised CTCF-proximal, and broadly distributed transcription-proximal, the latter correlated with gene length and expression. Moreover, single nucleotide accuracy reveals the influence primary DNA sequence has upon Top2 cleavage—distinguishing sites likely to form canonical DNA double-strand breaks (DSBs) from those predisposed to form strand-biased DNA single-strand breaks (SSBs) induced by etoposide (VP16) in vivo

Coupled ‘storm-flood’ depositional model: application to the Miocene–Modern Baram Delta Province, north-west Borneo

The Miocene to Modern Baram Delta Province is a highly efficient source to sink system that has accumulated 9 to 12 km of coastal-deltaic to shelf sediments over the past 15 Myr. Facies analysis based on ca 1 km of total vertical outcrop stratigraphy, combined with subsurface geology and sedimentary processes in the present-day Baram Delta Province, suggests a ‘storm-flood’ depositional model comprising two distinct periods: (i) fair-weather periods are dominated by alongshore sediment reworking and coastal sand accumulation; and (ii) monsoon-driven storm periods are characterised by increased wave energy and offshore-directed downwelling storm flow that occur simultaneously with peak fluvial discharge caused by storm-precipitation (‘storm-floods’). The modern equivalent environment has the following characteristics: (i) humid-tropical monsoonal climate; (ii) narrow (ca <100 km) and steep (ca 1°), densely vegetated, coastal plain; (iii) deep tropical weathering of a mudstone-dominated hinterland; (iv) multiple independent, small to moderate-sized (102 to 105 km2) drainage basins; (v) predominance of river-mouth bypassing; and (vi) supply-dominated shelf. The ancient, proximal part of this system (the onshore Belait Formation) is dominated by strongly cyclical sandier-upward successions (metre to decametre-scale) comprising (from bottom to top): (i) finely laminated mudstone with millimetre-scale silty laminae; (ii) heterolithic sandstone-mudstone alternations (centimetre to metre-scale); and (iii) sharp-based, swaley cross-stratified sandstone beds and bedsets (metre to decimetre-scale). Gutter casts (decimetre to metre-scale) are widespread, they are filled with swaley cross-stratified sandstone and their long-axes are oriented perpendicular to the palaeo-shoreline. The gutter casts and other associated waning-flow event beds suggest that erosion and deposition was controlled by high-energy, offshore-directed, oscillatory-dominated, sediment-laden combined flows within a shoreface to delta front setting. The presence of multiple river mouths and exceptionally high rates of accommodation creation (characteristic of the Neogene to Recent Baram Delta Province; up to 3000 m/Ma), in a ‘storm-flood’ dominated environment, resulted in a highly efficient and effective offshore-directed sediment transport system