Comparison of strontium isotope ratios in Mexican human hair and tap water as provenance indicators

Deceased undocumented border crossers are some of the most difficult individuals to identify due to the inability to narrow down the region of origin and therefore to obtain family reference samples for DNA comparison. The isotopic compositions of various body tissues have been demonstrated to be useful biomarkers for tracking locations and movements to aid in the identification of human remains. This study closes the large spatial gap of available 87Sr/86Sr ratios from North America in tap water and presents the first 87Sr/86Sr human tissue-based ratios from Mexico. The 101 hair samples from 32 locations in Mexico range in 87Sr/86Sr ratios from 0.70424 to 0.71613 (ΔSrmax–min = 0.01189). Furthermore, 151 tap water samples from 51 locations range between 0.70404 to 0.71385 (ΔSrmax–min = 0.00981). Overall, small variations in the hair and tap water samples collected from individual locations were recorded (ΔSrmax–min = 0.00041 and 0.00034 respectively). Despite the fact that Mexico is one of the largest bottled water consumers in the world, the 87Sr/86Sr ratios of human hair and tap water correlated strongly (R2 = 0.87 for location averages and R2 = 0.80 when using individual data points). These data represent a valuable resource for identifying the provenance of human remains

Robustness of quantum Markov chains

If the conditional information of a classical probability distribution of three random variables is zero, then it obeys a Markov chain condition. If the conditional information is close to zero, then it is known that the distance (minimum relative entropy) of the distribution to the nearest Markov chain distribution is precisely the conditional information. We prove here that this simple situation does not obtain for quantum conditional information. We show that for tri-partite quantum states the quantum conditional information is always a lower bound for the minimum relative entropy distance to a quantum Markov chain state, but the distance can be much greater; indeed the two quantities can be of different asymptotic order and may even differ by a dimensional factor.Comment: 14 pages, no figures; not for the feeble-minde

Sensitive Observations of Radio Recombination Lines in Orion and W51: The Data and Detection of Systematic Recombination Line Blueshifts Proportional to Impact Broadening

Sensitive spectral observations made in two frequency bands near 6.0 and 17.6 GHz are described for Orion and W51. Using frequency switching we were able to achieve a dynamic range in excess of 10,000 without fitting sinusoidal or polynomial baselines. This enabled us to detect lines as weak as T$_{A} ~1mK in these strong continuum sources. Hydrogen recombination lines with$\Delta n$ as high as 25 have been detected in Orion. In the Orion data, where the lines are stronger, we have also detected a systematic shift in the line center frequencies proportional to linewidth that cannot be explained by normal optical depth effects.Comment: 22 pages, 13 figures. Accepted for publication in Astrophysics and Space Scienc

Using multi-objective grammar-based genetic programming to integrate multiple social theories in agent-based modeling

Different theoretical mechanisms have been proposed for explaining complex social phenomena. For example, explanations for observed trends in population alcohol use have been postulated based on norm theory, role theory, and others. Many mechanism-based models of phenomena attempt to translate a single theory into a simulation model. However, single theories often only represent a partial explanation for the phenomenon. The potential of integrating theories together, computationally, represents a promising way of improving the explanatory capability of generative social science. This paper presents a framework for such integrative model discovery, based on multi-objective grammar-based genetic programming (MOGGP). The framework is demonstrated using two separate theory-driven models of alcohol use dynamics based on norm theory and role theory. The proposed integration considers how the sequence of decisions to consume the next drink in a drinking occasion may be influenced by factors from the different theories. A new grammar is constructed based on this integration. Results of the MOGGP model discovery process find new hybrid models that outperform the existing single-theory models and the baseline hybrid model. Future work should consider and further refine the role of domain experts in defining the meaningfulness of models identified by MOGGP

Information measures and classicality in quantum mechanics

We study information measures in quantu mechanics, with particular emphasis on providing a quantification of the notions of classicality and predictability. Our primary tool is the Shannon - Wehrl entropy I. We give a precise criterion for phase space classicality and argue that in view of this a) I provides a measure of the degree of deviation from classicality for closed system b) I - S (S the von Neumann entropy) plays the same role in open systems We examine particular examples in non-relativistic quantum mechanics. Finally, (this being one of our main motivations) we comment on field classicalisation on early universe cosmology.Comment: 35 pages, LATE

Back reaction in the formation of a straight cosmic string

A simple model for the formation of a straight cosmic string, wiggly or unperturbed is considered. The gravitational field of such string is computed in the linear approximation. The vacuum expectation value of the stress tensor of a massless scalar quantum field coupled to the string gravitational field is computed to the one loop order. Finally, the back-reaction effect on the gravitational field of the string is obtained by solving perturbatively the semiclassical Einstein's equations.Comment: 29 pages, LaTeX, no figures. A postcript version can be obtained from anonymous ftp at ftp://ftp.ifae.es/preprint.f

Quantum gates with neutral atoms: Controlling collisional interactions in time dependent traps

We theoretically study specific schemes for performing a fundamental two-qubit quantum gate via controlled atomic collisions by switching microscopic potentials. In particular we calculate the fidelity of a gate operation for a configuration where a potential barrier between two atoms is instantaneously removed and restored after a certain time. Possible implementations could be based on microtraps created by magnetic and electric fields, or potentials induced by laser light.Comment: 10 pages, 3 figure

Appraisal of a high protein distiller’s dried grain (DDG) in diets for European sea bass, Dicentrarchus labrax fingerlings on growth performance, haematological status and related gut histology

High protein distiller's dried grains (HP‐DDG) are co‐products of ethanol production that uses prefractionation technology. An 8‐week growth trial was conducted to investigate the effect of partial replacement of soybean meal (SBM) by three levels of HP‐DDG (30%, 40% and 50%) on growth performance, physiological parameters and histological changes of the intestine of European sea bass, Dicentrarchus labrax. The results indicated that an increased dietary level of HP‐DDG of more than 30% significantly increases growth performance and improved the FCR of sea bass. In addition, replacement of SBM by HP‐DDG enhanced feed intake efficiency and the health status of fish. Haematology and serum biochemistry (haemoglobin (Hb), red blood cells (RBCs), white blood cells (WBCs), packed cell volume (PCV %) and humeral immune parameters including total protein, albumin, globulin, cholesterol, lysozyme activity and total antioxidant capacity significantly increased with increase HP‐DDG inclusion levels. The findings of this study indicated that HP‐DDG is a good complementary protein source for inclusion aquaculture diets and levels above 30% as a replacement of SBM did not compromise growth performance and physiological parameters of sea bass while enhancing some important indices of health status in this species