5,600 research outputs found
Impact of the Spruce Budworm (Lepidoptera: Tortricidae) on the Ottawa and Hiawatha National Forests, 1978-1980
The Michigan Impact Plot System was established during 1978 and 1979 to obtain a data base for quantifying the impact of the spruce budworm in the Ottawa and Hiawatha National Forests. The formulae used to estimate the mean, total, and associated standard errors of the various parameters at the national forest and forest district levels are presented. We present the 1978, 1979, and 1980 impact data for the following parameters; percent mortality, total dead volume. dead volume per ha, live volume per ha, defoliation ranking, frequency and extent of top-kill, and incidence of spruce budworm feeding on saplings and regenera- tion. Statistics from an annual inventory of 108 composite ground sampling units (CGSU) in 1978, and 136 CGSU\u27s in 1979 and 1980 provide a more precise estimate ofthe impact of the spruce budworm in Michigan\u27s Upper Peninsula than ha~ been available to date
Teaching Casual Random Blood Glucose Screening to Second-Year Dental Students
In our project, archived casual random blood glucose levels of second-year dental students who were taught the mechanics of self-testing were retrieved. Material data were analyzed by calculating means, medians, standard deviations, and ranges for 161 dental students screened by this casual and random self-monitoring of blood glucose levels as described by the American Diabetes Association’s 2008 Standards of Medical Care in Diabetes. Three types of data were assessed in this study. The first was the casual blood glucose levels of second-year dental students. The second was the data retrieved from student questionnaires regarding the value of teaching casual random blood glucose screening. The third was the U.S. dental schools’ responses regarding inclusion of casual blood glucose screening in their current curricula. Second-year dental students self-reported hypoglycemia in three instances and hyperglycemia in eight, based on current American Diabetes Association standards. Students agreed or strongly agreed that the value of teaching was informative (92.3 percent), beneficial (95 percent), and something that might be included in their practices (78.2 percent), with 19.2 percent being neutral on the inclusion. Only six U.S. dental schools reported teaching casual random glucose screening
EXCEDE Technology Development III: First Vacuum Tests
This paper is the third in the series on the technology development for the
EXCEDE (EXoplanetary Circumstellar Environments and Disk Explorer) mission
concept, which in 2011 was selected by NASA's Explorer program for technology
development (Category III). EXCEDE is a 0.7m space telescope concept designed
to achieve raw contrasts of 1e6 at an inner working angle of 1.2 l/D and 1e7 at
2 l/D and beyond. This will allow it to directly detect and spatially resolve
low surface brightness circumstellar debris disks as well as image giant
planets as close as in the habitable zones of their host stars. In addition to
doing fundamental science on debris disks, EXCEDE will also serve as a
technological and scientific precursor for any future exo-Earth imaging
mission. EXCEDE uses a Starlight Suppression System (SSS) based on the PIAA
coronagraph, enabling aggressive performance.
We report on our continuing progress of developing the SSS for EXCEDE, and in
particular (a) the reconfiguration of our system into a more flight-like
layout, with an upstream deformable mirror and an inverse PIAA system, as well
as a LOWFS, and (b) testing this system in a vacuum chamber, including IWA,
contrast, and stability performance. The results achieved so far are 2.9e-7
contrast between 1.2-2.0 l/D and 9.7e-8 contrast between 2.0-6.0 l/D in
monochromatic light; as well as 1.4e-6 between 2.0-6.0 l/D in a 10% band, all
with a PIAA coronagraph operating at an inner working angle of 1.2 l/D. This
constitutes better contrast than EXCEDE requirements (in those regions) in
monochromatic light, and progress towards requirements in broadband light. Even
though this technology development is primarily targeted towards EXCEDE, it is
also germane to any exoplanet direct imaging space-based telescopes because of
the many challenges common to different coronagraph architectures and mission
requirements.Comment: 12 pages, 12 figures, to be published in proceedings of SPIE
Astronomical Telescopes + Instrumentation (2014
Direct Nano-Imaging of Light-Matter Interactions in Nanoscale Excitonic Emitters
Strong light-matter interactions in localized nano-emitters when placed near
metallic mirrors have been widely reported via spectroscopic studies in the
optical far-field. Here, we report a near-field nano-spectroscopic study of the
localized nanoscale emitters on a flat Au substrate. We observe strong-coupling
of the excitonic dipoles in quasi 2-dimensional CdSe/CdxZnS1-xS nanoplatelets
with gap mode plasmons formed between the Au tip and substrate. We also observe
directional propagation on the Au substrate of surface plasmon polaritons
launched from the excitons of the nanoplatelets as wave-like fringe patterns in
the near-field photoluminescence maps. These fringe patterns were confirmed via
extensive electromagnetic wave simulations to be standing-waves formed between
the tip and the emitter on the substrate plane. We further report that both
light confinement and the in-plane emission can be engineered by tuning the
surrounding dielectric environment of the nanoplatelets. Our results lead to
renewed understanding of in-plane, near-field electromagnetic signal
transduction from the localized nano-emitters with profound implications in
nano and quantum photonics as well as resonant optoelectronics.Comment: manuscript + supporting informatio
Energy Index For Aircraft Maneuvers
Method and system for analyzing, separately or in combination, kinetic energy and potential energy and/or their time derivatives, measured or estimated or computed, for an aircraft in approach phase or in takeoff phase, to determine if the aircraft is or will be put in an anomalous configuration in order to join a stable approach path or takeoff path. A 3 reference value of kinetic energy andor potential energy (or time derivatives thereof) is provided, and a comparison index .for the estimated energy and reference energy is computed and compared with a normal range of index values for a corresponding aircraft maneuver. If the computed energy index lies outside the normal index range, this phase of the aircraft is identified as anomalous, non-normal or potentially unstable
The attitude of patients with progressive ataxias towards clinical trials
Background
The development of new therapies may rely on the conduct of human experimentation as well as later clinical trials of therapeutic interventions. Ethical considerations seek to protect the patient from risk but few have sought to ascertain the attitude to such risk of patients with progressive debilitating or terminal conditions, for which no mitigating or curative therapies exist. Such understanding is also important if recruitment is to be maximized. We therefore sought to define the motivations for and barriers to trial participation amongst patients with progressive ataxias, as well as their condition-specific trial preferences.
Methods
We conducted an online survey consisting of 29 questions covering four key domains (demographics, personal motivation, drug therapy and study design) relating to the design of clinical trials. Two major ataxia charities, Ataxia UK and the Friedreich’s Ataxia Research Alliance (FARA) sent the survey to their members. Responses were analysed by disease and by ambulatory status.
Results
Of 342 respondents, 204 reported a diagnosis of Friedreich’s ataxia (FRDA), 55 inherited cerebellar ataxia (CA) and 70 idiopathic CA. The most important symptoms to be addressed by a trial were considered to be balance problems and ambulation, although these were superseded by speech problems in wheelchair users. Common motivations for participation were potential benefits to self and others. Reasons for non-participation included concerns about side effects, and the burden and cost of travel. Financial reimbursement for expenses was reported to be likely to increase trial engagement, Phase two trials were the most popular to participate in, and the use of a placebo arm was seen as a disincentive. Across all disease subgroups, drug repurposing trials proved popular and just under 70% of participants would be prepared to undergo intrathecal drug administration.
Conclusions
Knowledge of motivations for and barriers to trial participation as well as the acceptability of investigations, time commitments and routes of drug administration should inform better, more patient focused trial design. This in turn may improve recruitment and retention of participants to future trials
Accelerating root system phenotyping of seedlings through a computer-assisted processing pipeline
Background: There are numerous systems and techniques to measure the growth of plant roots. However, phenotyping large numbers of plant roots for breeding and genetic analyses remains challenging. One major difficulty is to achieve high throughput and resolution at a reasonable cost per plant sample. Here we describe a cost-effective root phenotyping pipeline, on which we perform time and accuracy benchmarking to identify bottlenecks in such pipelines and strategies for their acceleration.
Results: Our root phenotyping pipeline was assembled with custom software and low cost material and equipment. Results show that sample preparation and handling of samples during screening are the most time consuming task in root phenotyping. Algorithms can be used to speed up the extraction of root traits from image data, but when applied to large numbers of images, there is a trade-off between time of processing the data and errors contained in the database.
Conclusions: Scaling-up root phenotyping to large numbers of genotypes will require not only automation of sample preparation and sample handling, but also efficient algorithms for error detection for more reliable replacement of manual interventions
Ultrastrong Light-Matter Coupling in 2D Metal-Chalcogenates
Hybridization of excitons with photons to form hybrid quasiparticles,
exciton-polaritons (EPs), has been widely investigated in a range of
semiconductor material systems coupled to photonic cavities. Self-hybridization
occurs when the semiconductor itself can serve as the photonic cavity medium
resulting in strongly-coupled EPs with Rabi splitting energies > 200 meV at
room temperatures which recently were observed in layered two-dimensional (2D)
excitonic materials. Here, we report an extreme version of this phenomenon, an
ultrastrong EP coupling, in a nascent, 2D excitonic system, the metal organic
chalcogenate (MOCHA) compound named mithrene. The resulting self-hybridized EPs
in mithrene crystals placed on Au substrates show Rabi Splitting in the
ultrastrong coupling range (> 600 meV) due to the strong oscillator strength of
the excitons concurrent with the large refractive indices of mithrene. We
further show bright EP emission at room temperature as well as EP dispersions
at low-temperatures. Importantly, we find lower EP emission linewidth narrowing
to ~1 nm when mithrene crystals are placed in closed Fabry-Perot cavities. Our
results suggest that MOCHA materials are ideal for polaritonics in the deep
green-blue part of the spectrum where strong excitonic materials with large
optical constants are notably scarce
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