16,745 research outputs found
Clinical implications of the anisotropic analytical algorithm for IMRT treatment planning and verification
Get PDFPURPOSE:
To determine the implications of the use of the Anisotropic Analytical Algorithm(AAA) for the production and dosimetric verification of IMRT plans for treatments of the
prostate, parotid, nasopharynx and lung.
METHODS:
72 IMRT treatment plans produced using the Pencil Beam Convolution (PBC)algorithm were recalculated using the AAA and the dose distributions compared. 24 of the
plans were delivered to inhomogeneous phantoms and verification measurements made using a pinpoint ionisation chamber. The agreement between the AAA and measurement
was determined.
RESULTS:
Small differences were seen in the prostate plans, with the AAA predicting slightly lower minimum PTV doses. In the parotid plans, there were small increases in the lens and
contralateral parotid doses while the nasopharyngeal plans revealed a reduction in the volume of the PTV covered by the 95% isodose (the V95%) when the AAA was used. Large
changes were seen in the lung plans, the AAA predicting reductions in the minimum PTV dose and large reductions in the V95%. The AAA also predicted small increases in the mean
dose to the normal lung and the V20. In the verification measurements, all AAA calculations were within 3% or 3.5mm distance to agreement of the measured doses.
Conclusions: The AAA should be used in preference to the PBC algorithm for treatments involving low density tissue but this may necessitate re-evaluation of plan acceptability
criteria. Improvements to the Multi-Resolution Dose Calculation algorithm used in the inverse planning are required to reduce the convergence error in the presence of lung tissue. There was excellent agreement between the AAA and verification measurements for all sites
Rational tangle surgery and Xer recombination on catenanes
Full text linkThe protein recombinase can change the knot type of circular DNA. The action
of a recombinase converting one knot into another knot is normally
mathematically modeled by band surgery. Band surgeries on a 2-bridge knot
N((4mn-1)/(2m)) yielding a (2,2k)-torus link are characterized. We apply this
and other rational tangle surgery results to analyze Xer recombination on DNA
catenanes using the tangle model for protein-bound DNA.Comment: 20 pages, 23 figure
The Precision of Higgs Boson Measurements and Their Implications
Get PDFThe prospects for a precise exploration of the properties of a single or many
observed Higgs bosons at future accelerators are summarized, with particular
emphasis on the abilities of a Linear Collider (LC). Some implications of these
measurements for discerning new physics beyond the Standard Model (SM) are also
discussed.Comment: Summary report of the Precision Higgs Working Group P1WG2 at Snowmass
200
Déjà vu and the entorhinal cortex: dissociating recollective from familiarity disruptions in a single case patient
Get PDFPast research has demonstrated a relationship between déjà vu and the entorhinal cortex in patients with wider medial temporal lobe damage. The aim of the present research was to investigate this crucial link in a patient (MR) with a selective lesion to the left lateral entorhinal cortex to provide a more direct exploration of this relationship. Two experiments investigated the experiences of déjà vécu (using the IDEA questionnaire) and déjà vu (using an adapted DRM paradigm) in MR and a set of matched controls. The results demonstrated that MR had quantitatively more and qualitatively richer recollective experiences of déjà vécu. In addition, under laboratory-based déjà vu conditions designed to elicit both false recollection (critical lures) and false familiarity (weakly-associated lures), MR only revealed greater memory impairments for the latter. The present results are therefore the first to demonstrate a direct relationship between the entorhinal cortex and the experience of both déjà vu and déjà vécu. They furthermore suggest that the entorhinal cortex is involved in both weakly-associative false memory as well as strongly-associative memory under conditions that promote familiarity-based processing
FARM MACHINERY INVESTMENT AND THE TAX REFORM ACT OF 1986
Get PDFThe Tax Reform Act of 1986 significantly changed incentives for investing. This analysis specifically examines how changes in marginal tax rates, depreciation schedules, and the investment tax credit altered the cost of capital and net investment in agriculture. A stochastic coefficients econometric methodology is used to estimate an investment function which is then used to simulate the effects of tax reform. Estimates indicated that relative to prior law, the Tax Reform Act will reduce the capital stock of farm machinery and equipment by nearly $4 billion.Agricultural Finance, Farm Management,
Music Librarian as Development Officer: Raising Funds for Special Collections
Get PDFOver the past ten years, advances in technology have led to increased productivity and efficiency in nearly every area of librarianship. As a result, many music libraries across the United States are either beginning a special collections program or are turning to these collections for digitization; as special collections often consist of older materials no longer under copyright, they become priorities for digitization, which also affords a critical preservation benefit. As these collections grow, so does the need for funding, which is essential to their proper archival storage and long-term preservation. A review of the literature finds that little research has been published in the area of special collections fundraising, particularly specific to music; therefore, this article summarizes the literature and attempts to apply it to music special collections fundraising. Topics covered include grants and grant writing; employing a development officer or becoming one yourself; Friends\u27 groups; and, annual funds and other fundraising methods
Phaedra: The Influence and History of a Dramaturgical Mystery
Get PDFMany have debated the possible performance of Seneca\u27s plays. Theatre Historians have polarizing opinions on whether Seneca wrote them intending to perform for Roman Audiences. A comparative study of Euripides\u27 Hippolyte, Seneca\u27s Phaedra, and Sara Kane\u27s Phaedra\u27s Love demonstrates the flexibility of this story and its translation to different historical audiences. This further historical analysis illuminates clues within Seneca\u27s text and proves the possibility of staging, offering a new take on plays previously thought of as closet dramas
An Introduction to Theatre of Omniscience
Get PDFTheatre is an art of infinite possibility and is created and viewed from a variety of different lenses. Throughout history, artistic movements such as realism, surrealism, naturalism, expressionism, romanticism, and many more have influenced the ideologies of theatrical artists. Theatre practitioners make a stake in their artistic beliefs in the form of manifestos, which encapsulate their understanding in an abstract or concrete way. In reading and studying these manifestos, the individual then has the choice to follow suit to a school of thought, or derive their own philosophy. Theatre, in one viewpoint, can be understood as a means of omniscience, it allows the audience the possibility of understanding life as the third party, something they do not often have the chance to do in their day-to-day lives. Taking this outlook on theatre creates a different means of understanding the playwright, the actor, and their works. Analyzing the possibility of theatre through the lens of omniscience allows for a new understanding of what it means to create art and its impacts on practitioners and artists alike. In a subjective field, it is up to the individual to understand their means and methods of creating art above all else whether it be in a structured or abstract manner. In understanding the potential of Theatre of Omniscience, it opens the perspectives of practitioners allowing them to better understand their questions about life and orchestrate them onstage for audiences to ponder. It escalates theatre to be not only a form of entertainment, but a way to better comprehend questions that seems impossible to answer in their lives
The Primary Pretenders
Full text linkWe call a composite number q such that there exists a positive integer b with
b^p == b (mod q) a prime pretender to base b. The least prime pretender to base
b is the primary pretender q_b. It is shown that there are only 132 distinct
primary pretenders, and that q_b is a periodic function of b whose period is
the 122-digit number
19568584333460072587245340037736278982017213829337604336734362-
294738647777395483196097971852999259921329236506842360439300.Comment: 7 page
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