Toxic structures: Speculation and lead exposure in Detroit\u27s single-family rental market

Foreclosure sales permitted investors to purchase large volumes of low-cost residential properties after the last financial crisis, reshaping patterns of property ownership in low-income housing markets across the US. This study links post-foreclosure property acquisitions by investor-landlords to subsequent lead poisoning cases among children under age six living in Detroit, Michigan. We find that the odds of exhibiting elevated blood lead levels (≥ 5 μg/dL) are higher for children living in investor-owned homes purchased through tax foreclosure sale. These findings highlight the potential for property speculation in post-foreclosure housing markets to exacerbate severe and racialized burdens of excess lead toxicity in low-income communities

Pauli's Theorem and Quantum Canonical Pairs: The Consistency Of a Bounded, Self-Adjoint Time Operator Canonically Conjugate to a Hamiltonian with Non-empty Point Spectrum

In single Hilbert space, Pauli's well-known theorem implies that the existence of a self-adjoint time operator canonically conjugate to a given Hamiltonian signifies that the time operator and the Hamiltonian possess completely continuous spectra spanning the entire real line. Thus the conclusion that there exists no self-adjoint time operator conjugate to a semibounded or discrete Hamiltonian despite some well-known illustrative counterexamples. In this paper we evaluate Pauli's theorem against the single Hilbert space formulation of quantum mechanics, and consequently show the consistency of assuming a bounded, self-adjoint time operator canonically conjugate to a Hamiltonian with an unbounded, or semibounded, or finite point spectrum. We point out Pauli's implicit assumptions and show that they are not consistent in a single Hilbert space. We demonstrate our analysis by giving two explicit examples. Moreover, we clarify issues sorrounding the different solutions to the canonical commutation relations, and, consequently, expand the class of acceptable canonical pairs beyond the solutions required by Pauli's theorem.Comment: contains corrections to minor typographical errors of the published versio

A Tangible Construction Kit for Exploring Graph Theory

ABSTRACT Graphs are a versatile representation of many systems in computer science, the social sciences, and mathematics, but graph theory is not taught in schools. We present our work on Graphmaster, a computationally enhanced construction kit that enables children to build graphs of their own and investigate their properties by experimenting with algorithms that operate on them. The system is distributed; microcontrollers inside each node execute an interpreted language in parallel. Graphmaster, with its magnetic connectors, illuminated edges, and capacitive sensing, encourages children to develop intuitions about connectivity long before they are introduced to the notation and formulas of graph theory

Changing Clinicians' Behaviors in an Academic Medical Center: Does Institutional Commitment to Total Quality Management Matter?

The purpose of this project was to determine whether changing clinicians' behaviors to reduce costs in a large academic medical center is facilitated by the prior existence of a total quality management program. Ten teams, made up primarily of clinicians, were charged with devising strategies for altering specific clinical behaviors to reduce costs without detriment to quality of care. Half the teams followed the center's total quality management approach. Team success was assessed by how well three key tasks were completed: problem definition, design of plan of action, and plan implementation. Two teams achieved outright success es, three had outright failures, and five were in between. Adherence to a total quality management approach was not found to be associated with team suc cess. A much better predictor of success was the level of involvement and support by clinicians and managers; because that factor is largely controlled by institution al incentives, those incentives may need to be realigned before the effectiveness of a total quality management approach can be properly evaluated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67013/2/10.1177_0885713x9701200102.pd

Nanocone‐Modified Surface Facilitates Gas Bubble Detachment for High‐Rate Alkaline Water Splitting

Abstract: The significant amount of gas bubbles generated during high‐rate alkaline water splitting (AWS) can be detrimental to the process. The accumulation of bubbles will block the active catalytic sites and hinder the ion and electrolyte diffusion, limiting the maximum current density. Furthermore, the detachment of large bubbles can also damage the electrode's surface layer. Here, a general strategy for facilitating bubble detachment is demonstrated by modifying the nickel electrode surface with nickel nanocone nanostructures, which turns the surface into underwater superaerophobic. Simulation and experimental data show that bubbles take a considerably shorter time to detach from the nanocone‐modified nickel foil than the unmodified foil. As a result, these bubbles also have a smaller detachment size and less chance for bubble coalescence. The nanocone‐modified electrodes, including nickel foil, nickel foam, and 3D‐printed nickel lattice, all show substantially reduced overpotentials at 1000 mA cm−2 compared to their pristine counterpart. The electrolyzer assembled with two nanocone‐modified nickel lattice electrodes retains >95% of the performance after testing at ≈900 mA cm−2 for 100 h. The surface NC structure is also well preserved. The findings offer an exciting and simple strategy for enhancing the bubble detachment and, thus, the electrode activity for high‐rate AWS

Experimental validation of the influence of white matter anisotropy on the intracranial EEG forward solution

Forward solutions with different levels of complexity are employed for localization of current generators, which are responsible for the electric and magnetic fields measured from the human brain. The influence of brain anisotropy on the forward solution is poorly understood. The goal of this study is to validate an anisotropic model for the intracranial electric forward solution by comparing with the directly measured ‘gold standard’. Dipolar sources are created at known locations in the brain and intracranial electroencephalogram (EEG) is recorded simultaneously. Isotropic models with increasing level of complexity are generated along with anisotropic models based on Diffusion tensor imaging (DTI). A Finite Element Method based forward solution is calculated and validated using the measured data. Major findings are (1) An anisotropic model with a linear scaling between the eigenvalues of the electrical conductivity tensor and water self-diffusion tensor in brain tissue is validated. The greatest improvement was obtained when the stimulation site is close to a region of high anisotropy. The model with a global anisotropic ratio of 10:1 between the eigenvalues (parallel: tangential to the fiber direction) has the worst performance of all the anisotropic models. (2) Inclusion of cerebrospinal fluid as well as brain anisotropy in the forward model is necessary for an accurate description of the electric field inside the skull. The results indicate that an anisotropic model based on the DTI can be constructed non-invasively and shows an improved performance when compared to the isotropic models for the calculation of the intracranial EEG forward solution

Selection for High Oridonin Yield in the Chinese Medicinal Plant Isodon (Lamiaceae) Using a Combined Phylogenetics and Population Genetics Approach

Oridonin is a diterpenoid with anti-cancer activity that occurs in the Chinese medicinal plant Isodon rubescens and some related species. While the bioactivity of oridonin has been well studied, the extent of natural variation in the production of this compound is poorly known. This study characterizes natural variation in oridonin production in order to guide selection of populations of Isodon with highest oridonin yield. Different populations of I. rubescens and related species were collected in China, and their offspring were grown in a greenhouse. Samples were examined for oridonin content, genotyped using 11 microsatellites, and representatives were sequenced for three phylogenetic markers (ITS, rps16, trnL-trnF). Oridonin production was mapped on a molecular phylogeny of the genus Isodon using samples from each population as well as previously published Genbank sequences. Oridonin has been reported in 12 out of 74 species of Isodon examined for diterpenoids, and the phylogeny indicates that oridonin production has arisen at least three times in the genus. Oridonin production was surprisingly consistent between wild-collected parents and greenhouse-grown offspring, despite evidence of gene flow between oridonin-producing and non-producing populations of Isodon. Additionally, microsatellite genetic distance between individuals was significantly correlated with chemical distance in both parents and offspring. Neither heritability nor correlation with genetic distance were significant when the comparison was restricted to only populations of I. rubescens, but this result should be corroborated using additional samples. Based on these results, future screening of Isodon populations for oridonin yield should initially prioritize a broad survey of all species known to produce oridonin, rather than focusing on multiple populations of one species, such as I. rubescens. Of the samples examined here, I. rubescens or I. japonicus from Henan province would provide the best source of oridonin

Conventional B cells, not B-1 cells, are responsible for producing autoantibodies in lpr mice

Mice homozygous for the lpr gene develop autoantibodies and polyclonal B cell activation similar to what is seen in human systemic lupus erythematosus patients. We have previously shown that an lpr-specific intrinsic B cell defect was necessary for autoantibody production in this model. In the current study, we have further defined these autoantibody-producing B cells. Two major subsets of B cells have been described. B-1 cells (CD5+ B cells) can be distinguished from conventional B cells on the basis of phenotype, cytokine secretion, gene expression, anatomical location, and function. In addition, B-1 cells have been implicated in autoimmunity in several murine and human studies. To address the question of which B cell subset produces autoantibodies in lpr mice, we used immunoglobulin heavy chain (Igh) allotype-marked peritoneal (B-1 cell source) and bone marrow (conventional B cell source) cells from lpr mice to establish B cell chimeras. We used two general approaches. In one, we reconstituted sublethally irradiated mice with B-1 cells of one allotype and bone marrow cells of another allotype. In the second method, we suppressed endogenous B cells in neonatal mice with allotype-specific anti-IgM antibody, and injected peritoneal cells of another allotype. After antibody treatment was stopped, the mouse's conventional B cells recovered, but the B-1 subset was only reconstituted by the donor. In both types of chimeras, antichromatin, rheumatoid factor, and anti- single stranded DNA (ssDNA) autoantibodies were produced by the conventional B cell bone marrow source. In addition, an age-related decrease in peritoneal B-1 cells was seen, even in unmanipulated lpr mice. These data show that lpr B-1 cells are not important producers of autoantibodies. Conventional B cells are the source of autoantibodies directed at chromatin, ssDNA, and IgG