1,219 research outputs found
Effects of hypoxia on anabolic and catabolic gene expression and DNA methylation in OA chondrocytes
These findings demonstrate a role for hypoxia in the regulation of anabolic and catabolic gene expression and the influence of changes in DNA methylation. These results further support the role of epigenetics in OA and, critically, highlight the complex relationship between the physiological environment of cartilaginous cells and the osteoarthritic process with implications for therapeutic intervention and our understanding of OA pathophysiology
Primordial Density Fluctuations in a Dual Supergravity Cosmology
We analyse the spectrum of energy density fluctuations of a dual supergravity
model where the dilaton and the moduli are stabilized and sucessful inflation
is achieved inside domain walls that separate different vacua of the theory.
Constraints on the parameters of the superpotential are derived from the
amplitude of the primordial energy density fluctuations as inferred from COBE
and it is shown that the scale dependence of the tensor perturbations nearly
vanishes.Comment: 13 pages, Latex, 3 figures (uses epsf.sty
Approximations for the waiting-time distribution in an M/P H/c priority queue
We investigate the use of priority mechanisms when assigning service engineers to customers as a tool for service differentiation. To this end, we analyze a non-preemptive M/PH/c priority queue with various customer classes. For this queue, we present various accurate and fast methods to estimate the first two moments of the waiting time per class given that all servers are occupied. These waiting time moments allow us to approximate the overall waiting time distribution per class. We subsequently apply these methods to real-life data in a case study
Vibrational Analysis Of Amorphous Carbon-nitrogen Alloys By 15n And D Isotopic Substitution
The origin of the vibrational modes of a-CNx alloys is investigated by infrared (ir) and Raman spectroscopies. Isotopic substitution of 15N and D is used in the identification of vibration modes. In nonhydrogenated materials containing low nitrogen concentration (â€20 at. %), the ir and Raman spectra are not equivalent. Above this concentration (up to âŒ30 at. %), the spectra became very similar to each other. On the contrary, for a suitable hydrogen content the spectra are quite similar, independently of the range of nitrogen concentrations studied. Quantum chemical Parametric Method 3 calculations are performed to obtain the frequencies and intensities of the ir active vibrations of organic molecules and large carbon-nitrogen clusters. These results are used to help in the identification of the features observed in the ir spectra. The importance of both the promotion of bond dipoles and symmetry breaking by nitrogen in the ir spectra is established. ©2000 The American Physical Society.61210831087Fang, P.H., (1995) J. Mater. Sci. Lett., 14, p. 536Franceschini, D.F., Achete, C.A., Freire Jr., F.I., (1992) Appl. Phys. Lett., 60, p. 3229Jones, D.I., Stewart, A.D., (1982) Philos. Mag. B, 46, p. 423Chen, L.C., Lu, T.R., Cuo, C.T., Bhusari, D.M., Wu, J.J., Chen, K.H., Chen, T.M., (1998) Appl. Phys. Lett., 72, p. 3449Liu, A., Cohen, L., (1989) Science, 245, p. 841Kaufman, J.H., Metin, S., Saperstein, D.D., (1989) Phys. Rev. B, 39, p. 13053Souto, S., Alvarez, F., (1997) Appl. Phys. Lett., 70, p. 1539Hammer, P., Victoria, N.M., Alvarez, F., (1998) J. Vac. Sci. Technol. A, 16, p. 2941Alvarez, F., Victoria, N.M., Hammer, P., Freire Jr., F.L., Dos Santos, M.C., (1998) Appl. Phys. Lett., 73, p. 1065Alvarez, F., Dos Santos, M.C., Hammer, P., (1998) Appl. Phys. Lett., 73, p. 3521Souto, S., Pickholz, M., Dos Santos, M.C., Alvarez, F., (1998) Phys. Rev. B, 57, p. 2536Dos Santos, M.C., Alvarez, F., (1998) Phys. Rev. B, 58, p. 13918Stewart, J.J.P., (1989) J. Comput. Chem., 10, p. 209(1995) SPARTAN, Package V. 5, , Wavefunction, Inc(1996) HYPERCHEM, Version 5, , Hypercube, IncLey, L., (1984) Topics in Applied Physics, 56. , The Physics of Hydrogenated Amorphous Silicon II, edited by J. D. Joannopoulos and G. Lucousky, Springer-Verlag, BerlinSubramanian, V., Chitra, K., Venkatesh, K., Sanker, S., Ramasami, T., (1997) Chem. Phys. Lett., 264, p. 92Shinohara, Y., Saito, R., Kimura, T., Dresselhaus, G., Dresselhaus, M.S., (1994) Chem. Phys. Lett., 227, p. 365Borisenko, V.E., Baturin, A.V., Przeslawka, M., Koll, A., (1997) J. Mol. Struct., 407, p. 53Robertson, J., (1991) Prog. Solid State Chem., 21, p. 19
Brain age-dependent effects of acute endotoxemia on oxidative damage and mitochondrial function
Augmented Reality Based on SLAM to Assess Spatial Short-Term Memory
Spatial short-term memory is defined as the limited ability of people to retain and remember the location of elements for short periods of time. In this paper, we present the first AR app based on SLAM (Simultaneous Localization and Mapping) to assess spatial short-term memory. A total of 55 participants were involved in a study for remembering the real place where four virtual objects were located in the real environment. The participants were divided into two groups: the ARGroup (the participants learned the location of the virtual objects in the real environment in an adaptation phase using AR) and the NoARGroup (the participants learned the location of the objects by looking at photographs). The results indicated that the performance outcomes in remembering objects and their location for the participants in the ARGroup were statistically significantly greater than those obtained by the participants in the NoARGroup. From this result and our observations, we can conclude that touring the augmented environment helped the participants to better remember the location of virtual objects added to the real scene compared to looking at photographs of the environment. Furthermore, statistically significant differences were not found in relation to gender or age. Finally, our app has several advantages: 1) Our app works in any environment and does not require adding real elements to the environment; 2) the evaluators can select any real environment and place the virtual elements where they want and even change them between sessions; and 3) our app could work similar to the way spatial memory does in everyday life
Structure and property relationships of amorphous CNx: a joint experimental and theoretical study
Topological Inflation in Dual Superstring Models
We study the possibility of obtaining inflationary solutions from S-dual
superstring potentials. We find, in particular, that such solutions occur at
the core of domain walls separating degenerate minima whose positions differ by
modular transformations.Comment: 12 pages, uuencoded gzipped tar format, Latex, 2 figure
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