257 research outputs found
Random strings and tt-degrees of Turing complete C.E. sets
We investigate the truth-table degrees of (co-)c.e.\ sets, in particular,
sets of random strings. It is known that the set of random strings with respect
to any universal prefix-free machine is Turing complete, but that truth-table
completeness depends on the choice of universal machine. We show that for such
sets of random strings, any finite set of their truth-table degrees do not meet
to the degree~0, even within the c.e. truth-table degrees, but when taking the
meet over all such truth-table degrees, the infinite meet is indeed~0. The
latter result proves a conjecture of Allender, Friedman and Gasarch. We also
show that there are two Turing complete c.e. sets whose truth-table degrees
form a minimal pair.Comment: 25 page
The effect of illumination on the time to, and pupil area of, maximum mydriasis
This study was designed to evaluate the mydriatic effects of patients being dilated under differing illumination conditions. Twenty subjects, ten females and ten males had their pupils dilated under darkened conditions and under normal illumination to determine if there would be a difference in the rate of mydriasis, or overall pupil size at the point of maximum dilation. Iris color and gender were separately evaluated factors in dilation results. Subjects were dilated using one drop each of tetracaine 1%, phenylephrine HCI 2.5%, and tropicamide 1%. Pupil diameter was periodically measured using a Cogan\u27s pupilometer starting 6 minutes after drop instillation. Measurements with the pupilometer were taken at two minute intervals throughout the 30 minute test period. The final measurement 33 minutes after instillation of the dilating drops was taken with a biomicroscope reticule, both horizontal and vertical diameters were measured. No significant differences were seen between gender, iris color, or illumination type on the rate of maximum mydriasis. However, the relative pupil area was significantly greater following dilation under normal illumination conditions
Towards Large-Scale Quantum Networks
The vision of a quantum internet is to fundamentally enhance Internet
technology by enabling quantum communication between any two points on Earth.
While the first realisations of small scale quantum networks are expected in
the near future, scaling such networks presents immense challenges to physics,
computer science and engineering. Here, we provide a gentle introduction to
quantum networking targeted at computer scientists, and survey the state of the
art. We proceed to discuss key challenges for computer science in order to make
such networks a reality.Comment: To be presented at the Sixth Annual ACM International Conference on
Nanoscale Computing and Communication, Dublin, Irelan
Biology and Biological Control of Exotic True Thistles
“Thistle” is an old English name for a large variety of weedy, prickly plants that grow throughout the world. The most notable characteristics of thistles are the prickly stems and leaves and the bracts around the flower head. While many different plants have “thistle” in their common name, only certain plant species fit the taxonomic requirements of being considered “true thistles.” True thistle species fall within the family Asteraceae, the tribe Cardueae, and the subtribe Carduinae. Examples of plants that are not true thistles include yellow starthistle (subtribe Centaureinae), sow thistle (subtribe Sonchinae), and Russian thistle (family Chenopodiaceae). Only true thistles in the subtribe Carduinae are discussed in this manual
Biology and Biological Control of Exotic True Thistles
“Thistle” is an old English name for a large variety of weedy, prickly plants that grow throughout the world. The most notable characteristics of thistles are the prickly stems and leaves and the bracts around the flower head. While many different plants have “thistle” in their common name, only certain plant species fit the taxonomic requirements of being considered “true thistles.” True thistle species fall within the family Asteraceae, the tribe Cardueae, and the subtribe Carduinae. Examples of plants that are not true thistles include yellow starthistle (subtribe Centaureinae), sow thistle (subtribe Sonchinae), and Russian thistle (family Chenopodiaceae). Only true thistles in the subtribe Carduinae are discussed in this manual
The effect of illumination on the time to, and pupil area of, maximum mydriasis
This study was designed to evaluate the mydriatic effects of patients being dilated under differing illumination conditions. Twenty subjects, 1 a females and 1 a males, had their pupils dilated under darkened conditions and under normal illumination to determine if there would be a difference in the rate of mydriasis or overall pupil size at the point of maximum dilation. Iris colour and gender were separately evaluated factors in dilation results. Subjects were dilated using one drop each of 1% tetracaine, 2.5% phenylephrine HCI and 1% tropicamide. Pupil diameter was periodically measured using a Cogan pupillometer starting 6 minutes after drop instillation. Measurements with the pupillometer were taken at two-minute intervals throughout the 3 a-minute test period. The final measurement 33 minutes after instillation of the dilating drops was taken with a biomicroscope reticule; both horizontal and vertical diameters were measured. No Significant differences were seen between gender, iris colour and illumination type on the rate of maximum mydriasis. However, the relative pupil area was significantly greater following dilation under normal illumination conditions
The Global Care Ecosystems of 3D Printed Assistive Devices
The popularity of 3D printed assistive technology has led to the emergence of
new ecosystems of care, where multiple stakeholders (makers, clinicians, and
recipients with disabilities) work toward creating new upper limb prosthetic
devices. However, despite the increasing growth, we currently know little about
the differences between these care ecosystems. Medical regulations and the
prevailing culture have greatly impacted how ecosystems are structured and
stakeholders work together, including whether clinicians and makers
collaborate. To better understand these care ecosystems, we interviewed a range
of stakeholders from multiple countries, including Brazil, Chile, Costa Rica,
France, India, Mexico, and the U.S. Our broad analysis allowed us to uncover
different working examples of how multiple stakeholders collaborate within
these care ecosystems and the main challenges they face. Through our study, we
were able to uncover that the ecosystems with multi-stakeholder collaborations
exist (something prior work had not seen), and these ecosystems showed
increased success and impact. We also identified some of the key follow-up
practices to reduce device abandonment. Of particular importance are to have
ecosystems put in place follow up practices that integrate formal agreements
and compensations for participation (which do not need to be just monetary). We
identified that these features helped to ensure multi-stakeholder involvement
and ecosystem sustainability. We finished the paper with socio-technical
recommendations to create vibrant care ecosystems that include multiple
stakeholders in the production of 3D printed assistive devices
Identification of Eastern United States Reticulitermes Termite Species via PCR-RFLP, Assessed Using Training and Test Data
Reticulitermes termites play key roles in dead wood decomposition and nutrient cycling in forests. They also damage man-made structures, resulting in considerable economic loss. In the eastern United States, five species (R. flavipes, R. virginicus, R. nelsonae, R. hageni and R. malletei) have overlapping ranges and are difficult to distinguish morphologically. Here we present a molecular tool for species identification. It is based on polymerase chain reaction (PCR) amplification of a section of the mitochondrial cytochrome oxidase subunit II gene, followed by a three-enzyme restriction fragment length polymorphism (RFLP) assay, with banding patterns resolved via agarose gel electrophoresis. The assay was designed using a large set of training data obtained from a public DNA sequence database, then evaluated using an independent test panel of Reticulitermes from the Southern Appalachian Mountains, for which species assignments were determined via phylogenetic comparison to reference sequences. After refining the interpretive framework, the PCR-RFLP assay was shown to provide accurate identification of four co-occurring species (the fifth species, R. hageni, was absent from the test panel, so accuracy cannot yet be extended to training data). The assay is cost- and time-efficient, and will help improve knowledge of Reticulitermes species distributions
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