1,460 research outputs found
The Importance of Economic Perspective and Quantitative Approaches in Oncology Value Frameworks of Drug Selection and Shared Decision Making
The debate around value in oncology drug selection has been prominent in
recent years, and several professional bodies have furthered this debate
by advocating for so-called value frameworks. Herein, we provide a viewpoint
on these value frameworks, emphasizing the need to consider 4 key
aspects: (1) the economic underpinnings of value; (2) the importance of
the perspective adopted in the valuation; (3) the importance of the difference
between absolute and relative measures of risk and measuring
patient preferences; and (4) the recognition of multiple quality-of-life (QoL)
domains, and the aggregation and valuation of those domains, through
utilities within a multicriteria decision analysis, may allow prioritization of
QoL above the tallying of safety events, particularly in a value framework
focusing on the individual patient.
While several frameworks exist, they incorporate different attributes
andâimportantlyâassess value from alternative perspectives, including
those of patients, regulators, payers, and society. The various perspectives
necessarily lead to potentially different, if not sometimes divergent, conclusions
about the valuation. We show that the perspective of the valuation
affects the framing of the risk/benefit question and the methodology to
measure the individual patient choice, or preference, as opposed to the
collective, or population, choice.
We focus specifically on the American Society of Clinical Oncology
(ASCO) Value Framework. We argue that its laudable intent to assist in
shared clinician-patient decision making can be augmented by more formally
adopting methodology underpinned by micro- and health economic
concepts, as well as application of formal quantitative approaches. Our recommendations
for value frameworks focusing on the individual patient, such
as the ASCO Value Framework, are 3-fold: (1) ensure that stakeholders
understand the importance of the adopted (economic) perspective; (2)
consider using exclusively absolute measures of risk and formal patientpreference
methodology; and (3) consider foregoing safety parameters for
higher-order utility considerations
Gain limits of a Thick GEM in high-purity Ne, Ar and Xe
The dependence of the avalanche charge gain in Thick Gas Electron Multipliers
(THGEM) on the purity of Ne, Ar and Xe filling gases was investigated. The
gain, measured with alpha-particles in standard conditions (atmospheric
pressure, room temperature), was found to considerably drop in gases purified
by non-evaporable getters. On the other hand, small N2 admixtures to noble
gases resulted in high reachable gains. The results are of general relevance in
the operation of gas-avalanche detectors in noble gases, particularly that of
two-phase cryogenic detectors for rare events.Comment: 15 pages, 6 figures, submitted to JINS
Velocity-Based Gain-Scheduled Lateral Auto-Pilot For An Agile Missile
This paper investigates the application of velocity-based gain-scheduling
techniques to a demanding, highly nonlinear, missile control design task. Scheduling on
instantaneous incidence (a rapidly varying quantity) is well known to lead to
considerable difficulties with conventional gain-scheduling methods. Moreover, the
missile dynamics do not have well-defined relative degree at operating points where the
lateral velocity is zero and thus conventional feedback linearisation methods cannot be
applied to design a controller
Shading Reduces Yields of Edible Ginger Rhizomes Grown in Sub-Irrigated Pots
The purpose of this study was to determine the effects of four shading levels on the yield of edible ginger rhizomes that were grown in sub-irrigated pots under plastic-covered rainshelters
Bowhead whales, and not right whales, were the primary target of 16th- to 17th-century Basque Whalers in the Western North Atlantic
During the 16th and 17th centuries, Basque whalers travelled annually to the Strait of Belle Isle and Gulf of St. Lawrence to hunt whales. The hunting that occurred during this period is of primary significance for the North Atlantic right whale, Eubalaena glacialis (MĂŒller, 1776), because it has been interpreted as the largest human-induced reduction of the western North Atlantic population, with ~12250â21 000 whales killed. It has been frequently reported that the Basques targeted two species in this region: the North Atlantic right whale and the bowhead whale, Balaena mysticetus L., 1758. To evaluate this hypothesis and the relative impact of this period of whaling on both species, we collected samples from 364 whale bones during a comprehensive search of Basque whaling ports from the 16th to the 17th century in the Strait of Belle Isle and Gulf of St. Lawrence. Bones were found and sampled at 10 of the 20 sites investigated. DNA was extracted from a subset (n = 218) of these samples. Analysis of the mitochondrial cytochrome b region identified five whale species. The identification of only a single right whale bone and 203 bowhead whale bones from at least 72 individuals indicates that the bowhead whale was likely the principal target of the hunt. These results imply that this whaling had a much greater impact (in terms of numbers of whales removed) on the bowhead whale population than on the western North Atlantic right whale population.Aux XVIe et XVIIe siĂšcles, les baleiniers basques se rendaient tous les ans au dĂ©troit de Belle Isle et au golfe du Saint- Laurent pour faire la chasse aux baleines. La chasse qui sâest effectuĂ©e pendant cette pĂ©riode revĂȘt une grande importance pour la baleine franche ou baleine noire de lâAtlantique Nord, Eubalaena glacialis (MĂŒller, 1776), car cette activitĂ© serait interprĂ©tĂ©e comme la plus grande rĂ©duction de la population de baleines franches de lâAtlantique Nord causĂ©e par lâĂȘtre humain, au rythme dâenviron 12 250 Ă 21 000 baleines tuĂ©es. On a souvent signalĂ© que les Basques visaient deux espĂšces dans cette rĂ©gion, soit la baleine franche de lâAtlantique Nord et la baleine borĂ©ale, Balaena mysticetus L., 1758. Pour Ă©valuer cette hypothĂšse et lâincidence relative de cette pĂ©riode de pĂȘche aux baleines sur ces deux espĂšces, nous avons recueilli des Ă©chantillons provenant de 364 ossements de baleines dans le cadre dâune recherche approfondie de ports basques de chasse Ă la baleine remontant aux XVIe et XVIIe siĂšcles dans le dĂ©troit de Belle Isle et le golfe du Saint-Laurent. Des ossements ont Ă©tĂ© trouvĂ©s et Ă©chantillonnĂ©s Ă 10 des 20 sites ayant fait lâobjet de notre recherche. De lâADN a Ă©tĂ© extrait dâun sous-ensemble (n = 218) de ces Ă©chantillons. Lâanalyse mitochondriale cytochrome b de la rĂ©gion a permis dâidentifier cinq espĂšces de baleines. Lâidentification dâun seul os de baleine franche et de 203 os de baleines borĂ©ales provenant dâau moins 72 individus laisse croire que la baleine borĂ©ale Ă©tait probablement la cible principale des chasseurs. Ces rĂ©sultats impliquent que la chasse Ă la baleine a eu des incidences beaucoup plus grandes (en termes de nombres de baleines Ă©liminĂ©es) sur la population de baleines borĂ©ales que sur la population de baleines franches de lâouest de lâAtlantique Nord
Factorization of shell-model ground-states
We present a new method that accurately approximates the shell-model
ground-state by products of suitable states. The optimal factors are determined
by a variational principle and result from the solution of rather
low-dimensional eigenvalue problems. The power of this method is demonstrated
by computations of ground-states and low-lying excitations in sd-shell and
pf-shell nuclei.Comment: 5+epsilon pages, 5 eps-figures. Main additions: wave-function
overlaps, angular momentum expectation values, application to Ni56. To be
published as Rapid Communication in PR
Towards the architecture of an instructional multimedia database
The applicability of multimedia databases in education may be extended if they can serve multiple target groups, leading to affordable costs per unit for the user. In this contribution, an approach is described to build generic multimedia databases to serve that purpose. This approach is elaborated within the ODB Project ('Instructional Design of an Optical DataBase'); the term optical refers to the use of optical storage media to hold the audiovisual components. The project aims at developing a database in which a hypermedia encyclopedia is combined with instructional multimedia applications for different target groups at different educational levels. The architecture of the Optical Database will allow for switching between application types while working (for instance from tutorial instruction via the encyclopedia to a simulation and back). For instruction, the content of the database is thereby organized around so-called standard instruction routes: one route per target group. In the project, the teacher is regarded as the manager of instruction.\ud
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From that perspective, the database is primarily organized as a teaching facility. Central to the research is the condition that the architecture of the Optical Database has to enable teachers to select and tailor instruction routes to their needs in a way that is perceived as logical and easy to use
Increasing eigenstructure assignment design degree of freedom using lifting
This paper presents the exposition of an output-lifting eigenstructure assignment (EA) design framework, wherein the available EA design degrees of freedom (DoF) is significantly increased, and the desired eigenstructure of a single-rate full state feedback solution can be achieved within an output feedback system. A structural mapping is introduced to release the output-lifting causality constraint. Additionally, the available design DoF can be further enlarged via involving the input-lifting into the output-lifting EA framework. The newly induced design DoF can be utilised to calculate a structurally constrained, causal gain matrix which will maintain the same assignment capability. In this paper, the robustification of the output-lifting EA is also proposed, which allows a trade-off between performance and robustness in the presence of structured model uncertainties to be established. A lateral flight control benchmark in the EA literature and a numerical example are used to demonstrate the effectiveness of the design framework
General boundary conditions for the envelope function in multiband k.p model
We have derived general boundary conditions (BC) for the multiband envelope
functions (which do not contain spurious solutions) in semiconductor
heterostructures with abrupt heterointerfaces. These BC require the
conservation of the probability flux density normal to the interface and
guarantee that the multiband Hamiltonian be self--adjoint. The BC are energy
independent and are characteristic properties of the interface. Calculations
have been performed of the effect of the general BC on the electron energy
levels in a potential well with infinite potential barriers using a coupled two
band model. The connection with other approaches to determining BC for the
envelope function and to the spurious solution problem in the multiband k.p
model are discussed.Comment: 15 pages, 2 figures; to be published in Phys. Rev. B 65, March 15
issue 200
Simultaneous solution of Kompaneets equation and Radiative Transfer equation in the photon energy range 1 - 125 KeV
Radiative transfer equation in plane parallel geometry and Kompaneets
equation is solved simultaneously to obtain theoretical spectrum of 1-125 KeV
photon energy range. Diffuse radiation field is calculated using
time-independent radiative transfer equation in plane parallel geometry, which
is developed using discrete space theory (DST) of radiative transfer in a
homogeneous medium for different optical depths. We assumed free-free emission
and absorption and emission due to electron gas to be operating in the medium.
The three terms and where is photon phase density and , in Kompaneets equation and those due to
free-free emission are utilized to calculate the change in the photon phase
density in a hot electron gas. Two types of incident radiation are considered:
(1) isotropic radiation with the modified black body radiation [1] and
(2) anisotropic radiation which is angle dependent. The emergent radiation at
and reflected radiation are calculated by using the
diffuse radiation from the medium. The emergent and reflected radiation contain
the free-free emission and emission from the hot electron gas. Kompaneets
equation gives the changes in photon phase densities in different types of
media. Although the initial spectrum is angle dependent, the Kompaneets
equation gives a spectrum which is angle independent after several Compton
scattering times.Comment: 31 pages, 8 figures, Accepte
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