Publications by authors named "John A Hall"

Aggregates of conjugated organic molecules (i.e., dyes) may exhibit relatively large one- and two-exciton interaction energies, which has motivated theoretical studies on their potential use in quantum information science (QIS).

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Nanoarchitectural control of matter is crucial for next-generation technologies. DNA origami templates are harnessed to accurately position single molecules; however, direct single molecule evidence is lacking regarding how well DNA origami can control the orientation of such molecules in three-dimensional space, as well as the factors affecting control. Here, we present two strategies for controlling the polar () and in-plane azimuthal () angular orientations of cyanine Cy5 single molecules tethered on rationally-designed DNA origami templates that are physically adsorbed (physisorbed) on glass substrates.

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Molecular excitons play a foundational role in chromophore aggregates found in light-harvesting systems and offer potential applications in engineered excitonic systems. Controlled aggregation of chromophores to promote exciton delocalization has been achieved by covalently tethering chromophores to deoxyribonucleic acid (DNA) scaffolds. Although many studies have documented changes in the optical properties of chromophores upon aggregation using DNA scaffolds, more limited work has investigated how structural modifications of DNA via bridged nucleotides and chromophore covalent attachment impact scaffold stability as well as the configuration and optical behavior of attached aggregates.

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Wildland fires are diminishing air quality on a seasonal and regional basis, raising concerns about respiratory health risks to the public and occupational groups. This American Thoracic Society (ATS) workshop was convened in 2019 to meet the growing health threat of wildland fire smoke. The workshop brought together a multidisciplinary group of 19 experts, including wildland fire managers, public health officials, epidemiologists, toxicologists, and pediatric and adult pulmonologists.

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Sea-level rise (SLR) is not just a future trend; it is occurring now in most coastal regions across the globe. It thus impacts not only long-range planning in coastal environments, but also emergency preparedness. Its inevitability and irreversibility on long time scales, in addition to its spatial non-uniformity, uncertain magnitude and timing, and capacity to drive non-stationarity in coastal flooding on planning and engineering timescales, create unique challenges for coastal risk-management decision processes.

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Premise Of The Study: Plants that invest in large, heavy seeds and colorful, fleshy fruits or analogous structures seem adapted for dispersal by large vertebrates. Some such plants, like Australian cycads in the genus Macrozamia, do not disperse well, which could be explained by seed-dispersal relationships with megafauna that are rare or extinct in contemporary ecosystems. Such plants provide an opportunity to investigate the ecological consequences of low seed-dispersal distances.

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This essay drews attention to two books on empires by historians which deserve the attention of sociologists. Bang's model of the workings of the Roman economy powerfully demonstrates the tributary nature of per-industrial tributary empires. Darwin's analysis concentrates on modern overseas empires, wholly different in character as they involved the transportation of consumption items for the many rather than luxury goods for the few.

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Purpose: Differences in prostate cancer incidence, grade and stage at diagnosis, and survival in black vs nonblack men are well documented. Recent studies indicate that lipids may have a role in oncogenesis, including that of prostate cancer. We investigated the relationship between circulating lipids in black and nonblack patients, and newly diagnosed prostate cancer.

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To be relevant to societal interests and needs, conservation science must explicitly lend itself to solving real-world problems. Failure to evaluate under field conditions how a new technology or method performs or the cost of its implementation can prevent its acceptance by end users. Demonstration, defined here as the translation of scientific understanding into metrics of performance and cost of implementation under real-world conditions, is a logical step in the challenging progression from fundamental research to application.

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Background: As digital rectal examination (DRE) remains an essential part of a routine physical examination, it is important to understand its diagnostic value in different circumstances.

Aim: To quantify sensitivity, specificity and predictive value of DRE as a predictor of biopsy-confirmed prostate cancer in the US Veteran population.

Methods: The study group included 628 consecutive patients who underwent transrectal biopsy for suspected prostate cancer due to abnormal digital examination of the prostate, elevated serum prostate specific antigen (PSA) or both.

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Retention of Foley balloon in the bladder or urethra is a troublesome complication that presents a challenge to the urologist. We describe a complicated case of Foley catheter balloon retention (and trauma) within the urethra in an orthopedic patient undergoing hemiarthroplasty. The Foley balloon failed to deflate with standard methods.

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We provide a detailed description of the larval morphology of the Great Basin spadefoot toad (Scaphiopus intermontanus), a species with documented morphological variability in larval structures associated with feeding. We based our findings on laboratory-raised individuals fed a herbivorous diet. We characterized the morphology of the prometamorphic larva (limited to developmental stages 37 and 38) and then related our findings to the larval ecology of the species.

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In brief A 46-year-old man presented with symptoms of peripheral vascular disease in 1966. In 1976 arteriography revealed 100% occlusion of both femoral arteries at midthigh and some reconstitution of flow via collaterals into the popliteal region. His cholesterol level was initially 407 mg/100 ml, and his walking tolerance was 100 yards.

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