Intermediate Range Structure in Ion-Conducting Tellurite Glasses

We present ac conductivity spectra of tellurite glasses at several temperatures. For the first time, we report oscillatory modulations at frequencies around MHz. This effect is more pronounced the lower the temperature, and washes out when approaching the glass transition temperature $T_g$. We show, by using a minimal model, how this modulation may be attributed to the fractal structure of the glass at intermediate mesoscopic length scales

Anomalous diffusion with log-periodic modulation in a selected time interval

On certain self-similar substrates the time behavior of a random walk is modulated by logarithmic periodic oscillations on all time scales. We show that if disorder is introduced in a way that self-similarity holds only in average, the modulating oscillations are washed out but subdiffusion remains as in the perfect self-similar case. Also, if disorder distribution is appropriately chosen the oscillations are localized in a selected time interval. Both the overall random walk exponent and the period of the oscillations are analytically obtained and confirmed by Monte Carlo simulations.Comment: 4 pages, 5 figure

Local Einstein relation for fractals

We study single random walks and the electrical resistance for fractals obtained as the limit of a sequence of periodic structures. In the long-scale regime, power laws describe both the mean-square displacement of a random walk as a function of time and the electrical resistance as a function of length. We show that the corresponding power-law exponents satisfy the Einstein relation. For shorter scales, where these exponents depend on length, we find how the Einstein relation can be generalized to hold locally. All these findings were analytically derived and confirmed by numerical simulations.Comment: 12 pages, 6 figure

Anisotropic anomalous diffusion modulated by log-periodic oscillations

We introduce finite ramified self-affine substrates in two dimensions with a set of appropriate hopping rates between nearest-neighbor sites, where the diffusion of a single random walk presents an anomalous {\it anisotropic} behavior modulated by log-periodic oscillations. The anisotropy is revealed by two different random walk exponents, $\nu_x$ and $\nu_y$, in the {\it x} and {\it y} direction, respectively. The values of these exponents, as well as the period of the oscillation, are analytically obtained and confirmed by Monte Carlo simulations.Comment: 7 pages, 7 figure

What’s new in the YRRS? A look at new questionnaire items with a focus on sexual minority status.

Presented at: 2015 Annual Conference of the New Mexico Public Health Association; March 31-April 1, 2015; Albuquerque, NM.https://digitalrepository.unm.edu/prc-posters-presentations/1039/thumbnail.jp

Log-periodic modulation in one-dimensional random walks

We have studied the diffusion of a single particle on a one-dimensional lattice. It is shown that, for a self-similar distribution of hopping rates, the time dependence of the mean-square displacement follows an anomalous power law modulated by logarithmic periodic oscillations. The origin of this modulation is traced to the dependence on the length of the diffusion coefficient. Both the random walk exponent and the period of the modulation are analytically calculated and confirmed by Monte Carlo simulations.Comment: 6 pages, 7 figure

New Mexico Youth Risk & Resiliency 2013 Survey Results Report: Tobacco Use and Related Behaviors

Te negative effects of tobacco use are well documented: cigarette smoking has been linked to cancer, heart disease, and chronic obstructive pulmonary disease (COPD). The earlier a person initiates smoking, the greater their risk for long-term health problems and nicotine addiction. The Centers for Disease Control and Prevention (CDC) estimates that 1 in 5 high school students currently uses some form of tobacco. NM-YRRS measures tobacco use, attitudes, and behaviors among New Mexico students in grades 6–12

Muon Detection of TeV Gamma Rays from Gamma Ray Bursts

Because of the limited size of the satellite-borne instruments, it has not been possible to observe the flux of gamma ray bursts (GRB) beyond GeV energy. We here show that it is possible to detect the GRB radiation of TeV energy and above, by detecting the muon secondaries produced when the gamma rays shower in the Earth's atmosphere. Observation is made possible by the recent commissioning of underground detectors (AMANDA, the Lake Baikal detector and MILAGRO) which combine a low muon threshold of a few hundred GeV or less, with a large effective area of 10^3 m^2 or more. Observations will not only provide new insights in the origin and characteristics of GRB, they also provide quantitative information on the diffuse infrared background.Comment: Revtex, 12 pages, 3 postscript figures, uses epsfig.st

Stealth Acceleration and Modified Gravity

We show how to construct consistent braneworld models which exhibit late time acceleration. Unlike self-acceleration, which has a de Sitter vacuum state, our models have the standard Minkowski vacuum and accelerate only in the presence of matter, which we dub ``stealth-acceleration''. We use an effective action for the brane which includes an induced gravity term, and allow for an asymmetric set-up. We study the linear stability of flat brane vacua and find the regions of parameter space where the set-up is stable. The 4-dimensional graviton is only quasi-localised in this set-up and as a result gravity is modified at late times. One of the two regions is strongly coupled and the scalar mode is eaten up by an extra symmetry that arises in this limit. Having filtered the well-defined theories we then focus on their cosmology. When the graviton is quasi-localised we find two main examples of acceleration. In each case, we provide an illustrative model and compare it to LambdaCDM.Comment: 32 pages, 5 figure