Megapolitan Political Ecology and Urban Metabolism in Southern Appalachia

Drawing on megapolitan geographies, urban political ecology, and urban metabolism as theoretical frameworks, this article theoretically and empirically explores megapolitan political ecology. First, we elucidate a theoretical framework in the context of southern Appalachia and, in particular, the Piedmont megapolitan region, suggesting that the megapolitan region is a useful scale through which to understand urban metabolic connections that constitute this rapidly urbanizing area. We also push the environmental history and geography literature of the U.S. South and southern Appalachia to consider the central role urban metabolic connections play in the region's pressing social and environmental crises. Second, we empirically illuminate these human and nonhuman urban metabolisms across the Piedmont megapolitan region using data from the Coweeta Long-Term Ecological Research (LTER) program, especially highlighting a growing “ring of asphalt” that epitomizes several developing changes to patterns of metabolism. The conclusion suggests that changing urban metabolisms indicated by Coweeta LTER data, ranging from flows of people to flows of water, pose a complicated problem for regional governance and vitality in the future

Disease duration in autosomal dominant familial Alzheimer disease

OBJECTIVE: To use survival modeling to estimate disease duration in autosomal dominant familial Alzheimer disease (ADAD) and ascertain whether factors influencing age at onset also affect survival. METHODS: Symptomatic mutation carriers (201 presenilin 1 [PSEN1] and 55 amyloid precursor protein [APP]) from ADAD families referred to the Dementia Research Centre, between 1987 and 2019, were included. Survival was assessed with respect to age at onset, year of birth, APOE ε4 status, cognitive presentation, and sex using multilevel mixed-effects Weibull survival models. The contribution of mutation and family to variance in age at onset and duration was also assessed. RESULTS: Estimated mean survival was 11.6 (10.4–12.9) years and was similar for APP and PSEN1 mutations. Sixty-seven percent of the variance in age at onset was explained by mutation and 72% by mutation and family together. In contrast, only 6% of the variance in disease duration was explained by mutation specificity and 18% by family membership. Irrespective of gene, survival appeared longer for successive generations and in individuals with atypical presentations. Older age at onset was associated with longer duration within PSEN1 and shorter duration within APP mutation carriers. No differences in survival time were found between sexes or between mutations located before or beyond codon 200 within PSEN1. CONCLUSIONS: Survival is influenced by mutation to a much lesser extent than age at onset. Survival time has increased over time and is longer in atypical presentations. These insights may inform the interpretation of disease-modifying therapy trials in ADAD

Polaron states in fullerene adducts modeled by coarse-grained molecular dynamics and tight binding

Strong electron–phonon coupling leads to polaron localization in molecular semiconductor materials and influences charge transport, but it is expensive to calculate atomistically. Here, we propose a simple and efficient model to determine the energy and spatial extent of polaron states within a coarse-grained representation of a disordered molecular film. We calculate the electronic structure of the molecular assembly using a tight-binding Hamiltonian and determine the polaron state self-consistently by perturbing the site energies by the dielectric response of the surrounding medium to the charge. When applied to fullerene derivatives, the method shows that polarons extend over multiple molecules in C60 but localize on single molecules in higher adducts of phenyl-C61-butyric-acid-methyl-ester (PCBM) because of packing disorder and the polar side chains. In PCBM, polarons localize on single molecules only when energetic disorder is included or when the fullerene is dispersed in a blend. The method helps to establish the conditions under which a hopping transport model is justified

Polarization and temperature dependence of photoluminescence from zincblende and wurtzite InP nanowires

We use polarization-resolved and temperature-dependent photoluminescence of single zincblende (ZB) (cubic) and wurtzite (WZ) (hexagonal) InPnanowires to probe differences in selection rules and bandgaps between these two semiconductor nanostructures. The WZ nanowires exhibit a bandgap80meV higher in energy than the ZB nanowires. The temperature dependence of the PL is similar but not identical for the WZ and ZB nanowires. We find that ZB nanowires exhibit strong polarization parallel to the nanowire axis, while the WZ nanowires exhibit polarized emission perpendicular to the nanowire axis. This behavior is interpreted in terms of the different selection rules for WZ and ZB crystal structures.A.M., L.V.T., T.B.H., H.E.J., L.M.S., and J.M.Y.-R. acknowledge support from the Institute for Nanoscale Science and Technology of the University of Cincinnati and the National Science Foundation through Grant Nos. EEC/NUE 0532495 and ECCS 0701703. The Australian authors acknowledge support from the Australian Research Council. Y.K. acknowledges support by the Korean Science and Engineering Foundation KOSEF through Grant No. F01- 2007-000-10087-0

The development and implementation of a computer adaptive progress test across European countries

Longitudinal progress testing promotes self-directed deep learning across a full spectrum of knowledge, enabling early detection of underperformance and opportunities for remediation. Computer adaptive testing (CAT), where the difficulty of a test dynamically adjusts according to a test taker's ability, has benefits in a progress testing context, but significant resource and experience is required to develop appropriate test materials. This study describes how a transnational consortium from eight medical schools in five countries across Europe was formed to develop a computer adaptive progress test applicable across international curricula. 1,212 students from more than 40 nationalities took part in the study, of whom more than 70% were not native English speakers, though nearly all reported competence in English. A content map for an international assessment blueprint was agreed and a substantial bank of 1,127 English language progress test items was successfully calibrated after pilot testing to form the computer adaptive progress test (CA-PT) item bank. Results from the CA-PT pilot showed reliable convergence to stable estimates of ability, low standard errors of measurement and high test reliability for all participants. This study shows that an international collaborative consortium approach enables effective development of progress testing resources appropriate for computer adaptive testing, with potential for application across international borders and in populations where English is not the native language. Pooling resources internationally facilitates the comparison and development of appropriate assessment blueprints and the efficient generation of high-quality assessment items

Diversity, Equity, and Inclusiveness in Medicine and Cardiology: Next Steps for JAHA.

We, the Editors of the Journal of the American Heart Association, sincerely regret the publication of the article "Diversity, Inclusion, and Equity: Evolution of Race and Ethnicity Considerations for the Cardiology Workforce in the United States of America From 1969 to 2019".1 We are aware that the publication of this flawed and biased article has caused a great deal of unnecessary pain and anguish to a number of parties, and reflects extremely poorly on us. We fully support the retraction of this article

Asymmetric triplex metallohelices with high and selective activity against cancer cells

Small cationic amphiphilic α-helical peptides are emerging as agents for the treatment of cancer and infection, but they are costly and display unfavourable pharmacokinetics. Helical coordination complexes may offer a three-dimensional scaffold for the synthesis of mimetic architectures. However, the high symmetry and modest functionality of current systems offer little scope to tailor the structure to interact with specific biomolecular targets, or to create libraries for phenotypic screens. Here, we report the highly stereoselective asymmetric self-assembly of very stable, functionalized metallohelices. Their anti-parallel head-to-head-to-tail ‘triplex’ strand arrangement creates an amphipathic functional topology akin to that of the active sub-units of, for example, host-defence peptides and ​p53. The metallohelices display high, structure-dependent toxicity to the human colon carcinoma cell-line HCT116 ​p53++, causing dramatic changes in the cell cycle without DNA damage. They have lower toxicity to human breast adenocarcinoma cells (MDA-MB-468) and, most remarkably, they show no significant toxicity to the bacteria methicillin-resistant Staphylococcus aureus and Escherichia coli. At a glanc