1,221 research outputs found
A summary report on system effectiveness and optimization study
Report treats optimization and effectiveness separately. Report illustrates example of dynamic programming solution to system optimization. Computer algorithm has been developed to solve effectiveness problem and is included in report
Lean-inspired development work in agriculture: Implications for the work environment
Farmers operate in a turbulent environment that includes international competition,
weather conditions and animal behaviour, for example, and is difficult for them to control.
However, economy and productivity always have a high priority. As a consequence, farms have
started to implement lean-inspired work systems. At the same time, health and safety are of urgent
concern in the sector. This article explores how famers apply lean-inspired work processes. It
identifies work environment changes during and after a lean implementation, as well as possible
developments in the work environment following implementation of the lean philosophy. Data
were collected from three groups: lean, lean-light and development-inclined reference farms (in
total 54 farms), using a questionnaire and interviews. The results indicate that a majority of the
lean farms were applying several lean principles and tools, and the lean philosophy. The leanlight farms applied parts of the lean concept, while the reference farms applied some of the more
general tools, used in lean and elsewhere, such as visualisation in various forms and to various
extents. The results showed positive effects of lean on the psychosocial work environment, better
work structure and improved information, communication and co-operation. The physical work
environment was improved to some extent by lean, where advantages such as a more structured
and practical work environment with less physical movements and locomotion could be noticed.
The lean concept provided a more structured and systematic approach to dealing with work and
production environmental issues, for managers as well as for employees
Enhanced dispersion interaction between quasi-one dimensional conducting collinear structures
Recent investigations have highlighted the failure of a sum of terms
to represent the dispersion interaction in parallel metallic, anisotropic,
linear or planar nanostructures [J. F. Dobson, A. White, and A. Rubio, Phys.
Rev. Lett. 96, 073201 (2006) and references therein]. By applying a simple
coupled plasmon approach and using electron hydrodynamics, we numerically
evaluate the dispersion (non-contact van der Waals) interaction between two
conducting wires in a collinear pointing configuration. This case is compared
to that of two insulating wires in an identical geometry, where the dispersion
interaction is modelled both within a pairwise summation framework, and by
adding a pinning potential to our theory leading to a standard oscillator-type
model of insulating dielectric behavior. Our results provide a further example
of enhanced dispersion interaction between two conducting nanosystems compared
to the case of two insulating ones. Unlike our previous work, this calculation
explores a region of relatively close coupling where, although the electronic
clouds do not overlap, we are still far from the asymptotic region where a
single power law describes the dispersion energy. We find that strong
differences in dispersion attraction between metallic and semiconducting /
insulating cases persist into this non-asymptotic region. While our theory will
need to be supplemented with additional short-ranged terms when the electronic
clouds overlap, it does not suffer from the short-distance divergence exhibited
by purely asymptotic theories, and gives a natural saturation of the dispersion
energy as the wires come into contact.Comment: 10 pages, 5 figures. Added new extended numerical calculations, new
figures, extra references and heavily revised tex
Sex and Gender Topics in Medical Student Learners: Follow up
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Background: In an era of patient-centered, individualized medicine, it is important to consider of the impact of sex and gender on mechanisms of health and disease. Objectives: This study aimed to assess medical students’ current knowledge of sex and gender-based medical concepts and to compare responses to the prior assessment at Mayo Clinic in order to better inform ongoing efforts to improve medical education curricular materials.
Methods: An electronic survey that assessed current knowledge of sex and genderbased medicine was sent to all 1st – 4th year medical students at the Mayo Clinic Minnesota and Arizona campuses. Descriptive and qualitative thematic results were compared to the same survey administered in 2012 to assess the efficacy of curriculum changes in better covering sex and gender-based medicine topics.
Results: A total of 100 of 365 (27% response rate) of students responded, with 2:1 female to male with representation from all 4 years. The terms sex and gender were correctly identified by most respondents (93%). Various medical knowledge questions were answered incorrectly. Students reported many areas where concepts of sex and gender were not routinely covered n including orthopedics and nephrology, although these percentages have increased since 2012. Sixty two percent of students favored increasing sex and gender health concepts in the current curriculum.
Conclusions: Medical students appear to understand the definition of and importance of sex and gender. While some improvements in coverage by topic area have occurred, opportunity remains to more fully integrate these concepts in medical school curricula.https://jdc.jefferson.edu/sexandgenderhealth/1023/thumbnail.jp
Numerical Studies of a Confocal Resonator Pick-Up with FEMLAB
Diagnostic devices aimed at measuring beam profiles in high intensity accelerators are often perturbed by microwave fields generated by the beam itself upstream of the detection device, which propagate inside the vacuum pipe. These parasitic waveguide modes can significantly reduce the signal-to-noise ratio and thus the sensitivity of the beam monitor. This warrants investigation of detection devices that are sensitive to the direct electromagnetic fields of the beam, but largely ignore the parasitic waveguide modes. A new pick-up based on a confocal resonator configuration situated transversely to the direction of propagation of the beam is currently under development at Uppsala University, Sweden. Since a confocal resonator can have a high quality factor for the diffraction losses, then reciprocity suggests that it only couples weakly to external fields while keeping anyway a significant coupling to the direct fields of the beam. Numerical simulations were performed with FEMLAB to better characterize the electromagnetic properties of a confocal resonator pick-up to be operated in the multi-GHz range, especially in terms of eigen-frequencies and coupling to external electromagnetic fields. Our results were then compared to analytical predictions and a good agreement was found, despite a few limitations in the computation of the resonant modes. Having recently built a first confocal resonator prototype, we also performed experimental cross-checks of our numerical studies with a microwave network analyzer. Our results are presented in detail in this report and we discuss further applications of the confocal resonator microwave pick-up
The use of an artificial nucleotide for polymerase-based recognition of carcinogenic O6-alkylguanine DNA adducts.
Enzymatic approaches for locating alkylation adducts at single-base resolution in DNA could enable new technologies for understanding carcinogenesis and supporting personalized chemotherapy. Artificial nucleotides that specifically pair with alkylated bases offer a possible strategy for recognition and amplification of adducted DNA, and adduct-templated incorporation of an artificial nucleotide has been demonstrated for a model DNA adduct O(6)-benzylguanine by a DNA polymerase. In this study, DNA adducts of biological relevance, O(6)-methylguanine (O(6)-MeG) and O(6)-carboxymethylguanine (O(6)-CMG), were characterized to be effective templates for the incorporation of benzimidazole-derived 2'-deoxynucleoside-5'-O-triphosphates ( BENZI: TP and BIM: TP) by an engineered KlenTaq DNA polymerase. The enzyme catalyzed specific incorporation of the artificial nucleotide BENZI: opposite adducts, with up to 150-fold higher catalytic efficiency for O(6)-MeG over guanine in the template. Furthermore, addition of artificial nucleotide BENZI: was required for full-length DNA synthesis during bypass of O(6)-CMG. Selective incorporation of the artificial nucleotide opposite an O(6)-alkylguanine DNA adduct was verified using a novel 2',3'-dideoxy derivative of BENZI: TP. The strategy was used to recognize adducts in the presence of excess unmodified DNA. The specific processing of BENZI: TP opposite biologically relevant O(6)-alkylguanine adducts is characterized herein as a basis for potential future DNA adduct sequencing technologies
Atomic Supersymmetry, Rydberg Wave Packets, and Radial Squeezed States
We study radial wave packets produced by short-pulsed laser fields acting on
Rydberg atoms, using analytical tools from supersymmetry-based quantum-defect
theory. We begin with a time-dependent perturbative calculation for
alkali-metal atoms, incorporating the atomic-excitation process. This provides
insight into the general wave packet behavior and demonstrates agreement with
conventional theory. We then obtain an alternative analytical description of a
radial wave packet as a member of a particular family of squeezed states, which
we call radial squeezed states. By construction, these have close to minimum
uncertainty in the radial coordinates during the first pass through the outer
apsidal point. The properties of radial squeezed states are investigated, and
they are shown to provide a description of certain aspects of Rydberg atoms
excited by short-pulsed laser fields. We derive expressions for the time
evolution and the autocorrelation of the radial squeezed states, and we study
numerically and analytically their behavior in several alkali-metal atoms. Full
and fractional revivals are observed. Comparisons show agreement with other
theoretical results and with experiment.Comment: published in Physical Review
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