3,854 research outputs found

    The Selection of Talent for Stenography and Typing

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    H. C. Link states that The application of psychological tests in those fields where their value has been verified, is the only method short of the laborious and costly method of trial and error, which makes it possible to discover the exact ability, both innate and acquired, of an individual. Unless these facts are known, it becomes impossible to assign the individual to the work for which he is best fitted or to give him the training which he deserves. Once the potential and actual ability of an individual has been discovered the vocational selection or training of that individual can be decided with a measurable degree of intelligence

    Is the Pale Blue Dot unique? Optimized photometric bands for identifying Earth-like exoplanets

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    The next generation of ground and space-based telescopes will image habitable planets around nearby stars. A growing literature describes how to characterize such planets with spectroscopy, but less consideration has been given to the usefulness of planet colors. Here, we investigate whether potentially Earth-like exoplanets could be identified using UV-visible-to-NIR wavelength broadband photometry (350-1000 nm). Specifically, we calculate optimal photometric bins for identifying an exo-Earth and distinguishing it from uninhabitable planets including both Solar System objects and model exoplanets. The color of some hypothetical exoplanets - particularly icy terrestrial worlds with thick atmospheres - is similar to Earth's because of Rayleigh scattering in the blue region of the spectrum. Nevertheless, subtle features in Earth's reflectance spectrum appear to be unique. In particular, Earth's reflectance spectrum has a 'U-shape' unlike all our hypothetical, uninhabitable planets. This shape is partly biogenic because O2-rich, oxidizing air is transparent to sunlight, allowing prominent Rayleigh scattering, while ozone absorbs visible light, creating the bottom of the 'U'. Whether such uniqueness has practical utility depends on observational noise. If observations are photon limited or dominated by astrophysical sources (zodiacal light or imperfect starlight suppression), then the use of broadband visible wavelength photometry to identify Earth twins has little practical advantage over obtaining detailed spectra. However, if observations are dominated by dark current then optimized photometry could greatly assist preliminary characterization. We also calculate the optimal photometric bins for identifying extrasolar Archean Earths, and find that the Archean Earth is more difficult to unambiguously identify than a modern Earth twin.Comment: 10 figures, 38 page

    Concepts for Life Cycle Cost Control Required to Achieve Space Transportation Affordability and Sustainability

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    Cost control must be implemented through the establishment of requirements and controlled continually by managing to these requirements. Cost control of the non-recurring side of life cycle cost has traditionally been implemented in both commercial and government programs. The government uses the budget process to implement this control. The commercial approach is to use a similar process of allocating the non-recurring cost to major elements of the program. This type of control generally manages through a work breakdown structure (WBS) by defining the major elements of the program. If the cost control is to be applied across the entire program life cycle cost (LCC), the approach must be addressed very differently. A functional breakdown structure (FBS) is defined and recommended. Use of a FBS provides the visibifity to allow the choice of an integrated solution reducing the cost of providing many different elements of like function. The different functional solutions that drive the hardware logistics, quantity of documentation, operational labor, reliability and maintainability balance, and total integration of the entire system from DDT&E through the life of the program must be fully defined, compared, and final decisions made among these competing solutions. The major drivers of recurring cost have been identified and are presented and discussed. The LCC requirements must be established and flowed down to provide control of LCC. This LCC control will require a structured rigid process similar to the one traditionally used to control weight/performance for space transportation systems throughout the entire program. It has been demonstrated over the last 30 years that without a firm requirement and methodically structured cost control, it is unlikely that affordable and sustainable space transportation system LCC will be achieved

    Short-term emission line and continuum variations in Mrk110

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    We present results of a variability campaign of Mrk110 performed with the 9.2-m Hobby-Eberly Telescope (HET) at McDonald Observatory. The high S/N spectra cover most of the optical range. They were taken from 1999 November through 2000 May. The average interval between the observations was 7.3 days and the median interval was only 3.0 days. Mrk110 is a narrow-line Seyfert 1 galaxy. During our campaign the continuum flux was in a historically low stage. Considering the delays of the emission lines with respect to the continuum variations we could verify an ionization stratification of the BLR. We derived virial masses of the central black hole from the radial distances of the different emission lines and from their widths. The calculated central masses agree within 20%. Furthermore, we identified optical HeI singlet emission lines emitted in the broad-line region. The observed line fluxes agree with theoretical predictions. We show that a broad wing on the red side of the [OIII]5007 line is caused by the HeI singlet line at 5016A.Comment: 11 pages, 16 figures, A&A Latex. Accepted for publication in A&A Main Journa

    Entanglement between static and flying qubits in a semiconducting carbon nanotube

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    Entanglement can be generated by two electrons in a spin-zero state on a semiconducting single-walled carbon nanotube. The two electrons, one weakly bound in a shallow well in the conduction band, and the other injected into the conduction band, are coupled by the Coulomb interaction. Both transmission and entanglement are dependent on the well characteristics, which can be controlled by a local gate, and on the kinetic energy of the injected electron. Regimes with different degrees of electron correlation exhibit full or partial entanglement. In the latter case, the maximum entanglement can be estimated as a function of width and separation of a pair of singlet-triplet resonances.Comment: 17 pages and 12 figures, accepted to J. Phys. Cond. Ma

    The Influence of Health Care Professional Characteristics on Pain Management Decisions

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    Objective Evidence suggests that patient characteristics such as sex, race, and age influence the pain management decisions of health care providers. Although this signifies that patient demographics may be important determinants of health care decisions, pain-related care also may be impacted by the personal characteristics of the health care practitioner. However, the extent to which health care provider characteristics affect pain management decisions is unclear, underscoring the need for further research in this area. Methods A total of 154 health care providers (77 physicians, 77 dentists) viewed video vignettes of virtual human (VH) patients varying in sex, race, and age. Practitioners provided computerized ratings of VH patients’ pain intensity and unpleasantness, and also reported their willingness to prescribe non-opioid and opioid analgesics for each patient. Practitioner sex, race, age, and duration of professional experience were included as predictors to determine their impact on pain management decisions. Results When assessing and treating pain, practitioner sex, race, age, and duration of experience were all significantly associated with pain management decisions. Further, the role of these characteristics differed across VH patient sex, race, and age. Conclusions These findings suggest that pain assessment and treatment decisions may be impacted by the health care providers’ demographic characteristics, effects which may contribute to pain management disparities. Future research is warranted to determine whether findings replicate in other health care disciplines and medical conditions, and identify other practitioner characteristics (e.g., culture) that may affect pain management decisions

    LUMOS - Low and Intermediate Grade Glioma Umbrella Study of Molecular Guided TherapieS at relapse: Protocol for a pilot study

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    Grades 2 and 3 gliomas (G2/3 gliomas), when combined, are the second largest group of malignant brain tumours in adults. The outcomes for G2/3 gliomas at progression approach the dismal outcomes for glioblastoma (GBM), yet there is a paucity of trials for Australian patients with relapsed G2/3 gliomas compared with patients with GBM. LUMOS will be a pilot umbrella study for patients with relapsed G2/3 gliomas that aims to match patients to targeted therapies based on molecular screening with contemporaneous tumour tissue. Participants in whom no actionable or no druggable mutation is found, or in whom the matching drug is not available, will form a comparator arm and receive standard of care chemotherapy. The objective of the LUMOS trial is to assess the feasibility of this approach in a multicentre study across five sites in Australia, with a view to establishing a national molecular screening platform for patient treatment guided by the mutational analysis of contemporaneous tissue biopsies
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