4,775 research outputs found
Abundances of Disk Planetary Nebulae in M31 and the Radial Oxygen Gradient
We have obtained spectra of 16 planetary nebulae in the disk of M31 and
determined the abundances of He, N, O, Ne, S and Ar. Here we present the median
abundances and compare them with previous M31 PN disk measurements and with PNe
in the Milky Way. We also derive the radial oxygen gradient in M31, which is
shallower than that in the Milky Way, even accounting for M31's larger disk
scale length.Comment: 2 pages, 1 figure, 1 table, to appear in the proceedings of IAU
Symposium No. 283, Planetary Nebulae: An Eye to the Futur
Separator development for a heat sterilizable battery Final summary progress report, 1 May 1966 - 15 Mar. 1967
Development and testing of vivyl polymer separator materials for sterilized silver-zinc secondary batter
Empirical Studies of Evolving Systems
This paper describes the results of the working group investigating the issues of empirical studies for
evolving systems. The groups found that there were many issues that were central to successful evolution and this
concluded that this is a very important area within software engineering. Finally nine main areas were selected for consideration. For each of these areas the central issues were identified as well as success factors. In some cases success stories were also described and the critical factors accounting for the success analysed. In some cases it was later found that a number of areas were so tightly coupled that it was important to discuss them together
Development of improved semi-organic structural adhesives for elevated temperature applications Technical summary report, 1 ~JUL. 1964 - 29 ~FEB. 1968
Titanium chelate polymer adhesive formulation for aluminum joint curing in high temperature application
The Impact of Active Learning in a Speech-Language Pathology Swallowing and Dysphagia Course
The signature pedagogy in Speech-Language Pathology (SLP) higher education programs has been criticized for its instructor-centric lecture format and emphasis on the lower tiers of Bloom’s taxonomy (simply memorizing knowledge) at the expense of helping students develop the clinical problem-solving skills required for a lifetime of practice and learning. The purpose of this study was to examine the responses of a cohort of graduate speech-language pathology students to an active learning-oriented swallowing and dysphagia course design. A potential relationship between student perceptions of the active learning pedagogy and academic performance was also explored. The results suggest that active learning positively impacted both student perceptions and performance in the redesigned swallowing and dysphagia course
Mutations in repeating structural motifs of tropomyosin cause gain of function in skeletal muscle myopathy patients
The congenital myopathies include a wide spectrum of clinically, histologically and genetically variable neuromuscular disorders many of which are caused by mutations in genes for sarcomeric proteins. Some congenital myopathy patients have a hypercontractile phenotype. Recent functional studies demonstrated that ACTA1 K326N and TPM2 ΔK7 mutations were associated with hypercontractility that could be explained by increased myofibrillar Ca(2+) sensitivity. A recent structure of the complex of actin and tropomyosin in the relaxed state showed that both these mutations are located in the actin–tropomyosin interface. Tropomyosin is an elongated molecule with a 7-fold repeated motif of around 40 amino acids corresponding to the 7 actin monomers it interacts with. Actin binds to tropomyosin electrostatically at two points, through Asp25 and through a cluster of amino acids that includes Lys326, mutated in the gain-of-function mutation. Asp25 interacts with tropomyosin K6, next to K7 that was mutated in the other gain-of-function mutation. We identified four tropomyosin motifs interacting with Asp25 (K6-K7, K48-K49, R90-R91 and R167-K168) and three E-E/D-K/R motifs interacting with Lys326 (E139, E181 and E218), and we predicted that the known skeletal myopathy mutations ΔK7, ΔK49, R91G, ΔE139, K168E and E181K would cause a gain of function. Tests by an in vitro motility assay confirmed that these mutations increased Ca(2+) sensitivity, while mutations not in these motifs (R167H, R244G) decreased Ca(2+) sensitivity. The work reported here explains the molecular mechanism for 6 out of 49 known disease-causing mutations in the TPM2 and TPM3 genes, derived from structural data of the actin–tropomyosin interface
PEN: a low energy test of lepton universality
Allowed charged meson decays are characterized by simple dynamics, few
available decay channels, mainly into leptons, and extremely well controlled
radiative and loop corrections. In that sense, pion decays represent a
veritable triumph of the standard model (SM) of elementary particles and
interactions. This relative theoretical simplicity makes charged pion decays a
sensitive means for testing the underlying symmetries and the universality of
weak fermion couplings, as well as for studying pion structure and chiral
dynamics. Even after considerable recent improvements, experimental precision
is lagging far behind that of the theoretical description for pion decays. We
review the current state of experimental study of the pion electronic decay
, or , where the
indicates inclusion and explicit treatment of radiative decay events. We
briefly review the limits on non-SM processes arising from the present level of
experimental precision in decays. Focusing on the PEN
experiment at the Paul Scherrer Institute (PSI), Switzerland, we examine the
prospects for further improvement in the near term.Comment: 11 pages, 5 figures; paper presented at the XIII International
Conference on Heavy Quarks and Leptons, 22-27 May 2016, Blacksburg, Virginia,
US
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