1,093 research outputs found
Search Interfaces for Mathematicians
Access to mathematical knowledge has changed dramatically in recent years,
therefore changing mathematical search practices. Our aim with this study is to
scrutinize professional mathematicians' search behavior. With this
understanding we want to be able to reason why mathematicians use which tool
for what search problem in what phase of the search process. To gain these
insights we conducted 24 repertory grid interviews with mathematically inclined
people (ranging from senior professional mathematicians to non-mathematicians).
From the interview data we elicited patterns for the user group
"mathematicians" that can be applied when understanding design issues or
creating new designs for mathematical search interfaces.Comment: conference article "CICM'14: International Conference on Computer
Mathematics 2014", DML-Track: Digital Math Libraries 17 page
Recommended from our members
Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems
Computer models have been developed for evaluating conceptual designs of integrated coal gasification combined cycle power plants. An overall system model was developed for performing thermodynamic cycle analyses, and detailed models were developed for predicting performance characteristics of fixed bed coal gasifiers and hot gas clean up subsystem components. The overall system model performs mass and energy balances and does chemical equilibrium analyses to determine the effects of changes in operating conditions, or to evaluate proposed design changes. An existing plug flow model for fixed bed gasifiers known as the Wen II model was revised and updated. Also, a spread sheet model of zinc ferrite sulfur sorbent regeneration subsystem was developed. Parametric analyses were performed to determine how performance depends on variables in the system design. The work was done to support CRS Sirrine Incorporated in their study of standardized air blown coal gasifier gas turbine concepts
A Minimal Superstring Standard Model II: A Phenomenological Study
Recently, we demonstrated the existence of heterotic--string solutions in
which the observable sector effective field theory just below the string scale
reduces to that of the MSSM, with the standard observable gauge group being
just SU(3)_C x SU(2)_L x U(1)_Y and the SU(3)_C x SU(2)_L x U(1)_Y-charged
spectrum of the observable sector consisting solely of the MSSM spectrum.
Associated with this model is a set of distinct flat directions of vacuum
expectation values (VEVs) of non-Abelian singlet fields that all produce solely
the MSSM spectrum. In this paper, we study the effective superpotential induced
by these choices of flat directions. We investigate whether sufficient degrees
of freedom exist in these singlet flat directions to satisfy various
phenomenological constraints imposed by the observed Standard Model data. For
each flat direction, the effective superpotential is given to sixth order. The
variations in the singlet and hidden sector low energy spectrums are analyzed.
We then determine the mass matrices (to all finite orders) for the three
generations of MSSM quarks and leptons. Possible Higgs mu-terms are
investigated. We conclude by considering generalizations of our flat directions
involving VEVs of non-Abelian fields.Comment: 41 pages. Standard Late
75th Anniversary of âExistence of Electromagnetic-Hydrodynamic Wavesâ
We have recently passed the 75th anniversary of one of the most important
results in solar and space physics: Hannes Alfv\'en's discovery of Alfv\'en
waves and the Alfv\'en speed. To celebrate the anniversary, this article
recounts some major episodes in the history of MHD waves. Following an
initially cool reception, Alfv\'en's ideas were propelled into the spotlight by
Fermi's work on cosmic rays, the new mystery of coronal heating and, as
scientific perception of interplanetary space shifted dramatically and the
space race started, detection of Alfv\'en waves in the solar wind. From then
on, interest in MHD waves boomed, laying the foundations for modern remote
observations of MHD waves in the Sun, coronal seismology and some of today's
leading theories of coronal heating and solar wind acceleration. In 1970,
Alfv\'en received the Nobel Prize for his work in MHD, including these
discoveries. The article concludes with some reflection about what the history
implies about the way we do science, especially the advantages and pitfalls of
idealised mathematical models.Comment: 10 pages, accepted by Solar Physic
Toward a Rapid Production of Multivirus-Specific T Cells Targeting BKV, Adenovirus, CMV, and EBV from Umbilical Cord Blood
Umbilical cord blood (CB) has emerged as an effective alternative donor source for hematopoietic stem cell transplantation. Despite this success, the prolonged duration of immune suppression following CB transplantation and the naivetĂ© of CB T cells leave patients susceptible to viral infections. Adoptive transfer of ex vivo-expanded virus-specific T cells from CB is both feasible and safe. However, the manufacturing process of these cells is complicated, lengthy, and labor-intensive. We have now developed a simplified method to manufacture a single culture of polyclonal multivirus-specific cytotoxic T cells in less than 30 days. It eliminates the need for a live virus or transduction with a viral vector, thus making this approach widely available and GMP-applicable to target multiple viruses. The use of overlapping PepMixes as a source of antigen stimulation enable expansion of the repertoire of the T cell product to any virus of interest and make it available as a third party âoff the shelfâ treatment for viral infections following transplantation
Chronic Outpatient Sildenafil Therapy for Pulmonary Hypertension in a Child After Cardiac Surgery
We report the case of a 14-month-old male with d-transposition of the great arteries, ventricular septal defect, and pulmonary hypertension successfully treated with long-term sildenafil following cardiac surgery. To our knowledge, this is the first published report of long-term sildenafil treatment in a child after corrective cardiac surgery
Structural and biophysical characterization of bacillus thuringiensis insecticidal proteins Cry34Ab1 and Cry35Ab1
Bacillus thuringiensis strains are well known for the production of insecticidal proteins upon sporulation and these proteins are deposited in parasporal crystalline inclusions. The majority of these insect-specific toxins exhibit three domains in the mature toxin sequence. However, other Cry toxins are structurally and evolutionarily unrelated to this three-domain family and little is known of their three dimensional structures, limiting our understanding of their mechanisms of action and our ability to engineer the proteins to enhance their function. Among the non-three domain Cry toxins, the Cry34Ab1 and Cry35Ab1 proteins from B. thuringiensis strain PS149B1 are required to act together to produce toxicity to the western corn rootworm (WCR) Diabrotica virgifera virgifera Le Conte via a pore forming mechanism of action. Cry34Ab1 is a protein of âŒ14 kDa with features of the aegerolysin family (Pfam06355) of proteins that have known membrane disrupting activity, while Cry35Ab1 is a âŒ44 kDa member of the toxin_10 family (Pfam05431) that includes other insecticidal proteins such as the binary toxin BinA/BinB. The Cry34Ab1/Cry35Ab1 proteins represent an important seed trait technology having been developed as insect resistance traits in commercialized corn hybrids for control of WCR. The structures of Cry34Ab1 and Cry35Ab1 have been elucidated to 2.15 Ă
and 1.80 Ă
resolution, respectively. The solution structures of the toxins were further studied by small angle X-ray scattering and native electrospray ion mobility mass spectrometry. We present here the first published structure from the aegerolysin protein domain family and the structural comparisons of Cry34Ab1 and Cry35Ab1 with other pore forming toxins
ELISPOT and intracellular cytokine staining: Novel assays for quantifying T cell responses in the chicken
Extreme Ultra-Violet Spectroscopy of the Lower Solar Atmosphere During Solar Flares
The extreme ultraviolet portion of the solar spectrum contains a wealth of
diagnostic tools for probing the lower solar atmosphere in response to an
injection of energy, particularly during the impulsive phase of solar flares.
These include temperature and density sensitive line ratios, Doppler shifted
emission lines and nonthermal broadening, abundance measurements, differential
emission measure profiles, and continuum temperatures and energetics, among
others. In this paper I shall review some of the advances made in recent years
using these techniques, focusing primarily on studies that have utilized data
from Hinode/EIS and SDO/EVE, while also providing some historical background
and a summary of future spectroscopic instrumentation.Comment: 34 pages, 8 figures. Submitted to Solar Physics as part of the
Topical Issue on Solar and Stellar Flare
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