General mathematical formulation of scattering processes in atom-diatomic collisions in the RmatReact methodology.

Accurately modelling cold and ultracold reactive collisions occurring over deep potential wells, such as [Formula: see text], requires the development of new theoretical and computational methodologies. One potentially useful framework is the R-matrix method adopted widely for electron-molecule collisions which has more recently been applied to non-reactive heavy-particle collisions such as Ar-Ar. The existing treatment of non-reactive elastic and inelastic scattering needs to be substantially extended to enable modelling of reactive collisions: this is the subject of this paper. Herein, we develop the general mathematical formulation for non-reactive elastic and inelastic scattering, photoassociation, photodissociation, charge exchange and reactive scattering using the R-matrix method. Of particular note is that the inner region, of central importance to calculable R-matrix methodologies, must be finite in all scattering coordinates rather than a single scattering coordinate as for non-reactive scattering. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H3+, H5+ and beyond'.

Who were they really? model-free and model-bound dental nonmetric analyses to affirm documented population affiliations of seven South African "Bantu" samples.

OBJECTIVES: For bioarchaeological biodistance analyses it is common to "assume" that skeletal samples are representative of the populations to which they are attributed. Here, alternatively, samples with "known" attribution in the Raymond A. Dart Collection are assessed regarding their suitability for use in such analyses. Prior curation issues may call their ascribed identities into question. MATERIALS AND METHODS: These 20th century samples ostensibly derive from South African Ndebele, Sotho, Swazi, Tswana, Venda, Xosa, and Zulu populations. First, the mean measure of divergence (MMD) is used to obtain among-sample dental phenetic distances for comparison with documented population relationships. Second, the Mantel test evaluates fit of the isolation-by-distance model between MMD and geographic distances, i.e., among the historic homelands. Third, R-matrices and minimum and estimated Fst from MMD distances give an indication of genetic micro-differentiation. RESULTS: Output from these model-free and model-bound analyses suggest that five and perhaps six samples are representative of their attributed populations-presenting differences along population lines and evidence of more ancient ancestry. DISCUSSION: Other than the Swazi and perhaps Nedebele, the among-sample variation: 1) mirrors documented population history, 2) reveals a moderately positive correlation between phenetic and geographic distances, and 3) although evidencing much homogeneity, provides measures of genetic distance in support of the phenetic distances. Therefore, with the two noted exceptions-perhaps from collection issues, swamping of past genetic structure, or both, most samples appear suitable for bioarchaeological analyses. On this basis, results are offered to supplement published findings concerning the biological relationships of these peoples.

Phenotypic variation of transitional forager-farmers in the Sonoran Desert.

This study examines phenotypic variation and biological distances estimated using morphological traits from three Early Agricultural period (EAP) (2100 BC-AD 50) site-complexes in the Sonoran Desert of southern Arizona and northern Sonora. The hypothesis tested is that EAP forager-farmers were phenotypically homogenous as suggested by patterns in material culture and works to refine inferences regarding gene flow and biological affinity during subsistence transitions. Seven measurements from 62 EAP male and female crania were collected and used to calculate phenotypic variances, biological distances, and FST values with RMET 5.0 software. Analyses were applied to both pooled site-complex samples and to males and females separately. Results show differential variation between site-complex population samples, multiple significant biological distances, and significant FST values for the EAP regional sample that indicate widespread phenotypic heterogeneity rather than homogeneity. Significantly lower than expected variance in the Cienega Creek male sample is inferred to suggest a small closely related population present during the Cienega phase. Greater than expected male variation is attributed to higher frequencies of gene flow in the La Playa and Santa Cruz River site-complex samples. These EAP males are inferred to be more mobile across the Sonoran Desert landscape and representative of multiple biological affinities compared with females. This study provides evidence supporting the canalization of phenotypic variation when associated with human populations becoming increasingly sedentary due to transitioning subsistence practices.

Uniquely identifying topological order based on boundary-bulk duality and anyon condensation.

Topological order is a new quantum phase that is beyond Landau's symmetry-breaking paradigm. Its defining features include robust degenerate ground states, long-range entanglement and anyons. It was known that R and F matrices, which characterize the fusion-braiding properties of anyons, can be used to uniquely identify topological order. In this article, we explore an essential question: how can the R and F matrices be experimentally measured? We show that the braidings, i.e. the R matrices, can be completely determined by the half braidings of boundary excitations due to the boundary-bulk duality and the anyon condensation. The F matrices can also be measured by comparing the quantum states involving the fusion of three anyons in two different orders. Thus we provide a model-independent experimental protocol to uniquely identify topological order. By using quantum simulations based on a toric code model with boundaries encoded in three- and four-qubit systems and state-of-the-art technology, we obtain the first experimental measurement of R and F matrices by means of an NMR quantum computer at room temperature.

A One-Dimensional Effective Model for Nanotransistors in Landauer-Büttiker Formalism.

In a series of publications, we developed a compact model for nanotransistors in which quantum transport in a variety of industrial nano-FETs was described quantitatively. The compact nanotransistor model allows for the extraction of important device parameters as the effective height of the source-drain barrier, device heating, and the quality of the coupling between conduction channel and the contacts. Starting from a basic description of quantum transport in a multi-terminal device in Landauer-Büttiker formalism, we give a detailed derivation of all relevant formulas necessary to construct our compact nanotransistor model. Here we make extensive use of the the R-matrix method.

A new analysis interpreting Nilotic relationships and peopling of the Nile Valley.

The process of the peopling of the Nile Valley likely shaped the population structure and early biological similarity of Egyptians and Nubians. As others have noted, affinity among Nilotic populations was due to an aggregation of events, including environmental, linguistic, and sociopolitical changes over a great deal of time. This study seeks to evaluate the relationships of Nubian and Egyptian groups in the context of the original peopling event. Cranial nonmetric traits from 18 Nubian and Egyptian samples, spanning Lower Egypt to Lower Nubia and approximately 7400 years, were analyzed using Mahalanobis D2 as a measure of biological distance. A principal coordinates analysis and spatial-temporal model were applied to these data. The results reveal temporal and spatial patterning consistent with documented events in Egyptian and Nubian population history. Moreover, the Mesolithic Nubian sample clustered with later Nubian and Egyptian samples, indicating that events prior to the Mesolithic were important in shaping the later genetic patterning of the Nubian population. Later contact through the establishment of the Egyptian fort at Buhen, Kerma's position as a strategic trade center along the Nile, and Egyptian colonization at Tombos maintained genetic similarity among the populations.

Elimination of interference from water in KBr disk FT-IR spectra of solid biomaterials by chemometrics solved with kinetic modeling.

Infrared analysis of proteins and polysaccharides by the well known KBr disk technique is notoriously frustrated and defeated by absorbed water interference in the important amide and hydroxyl regions of spectra. This interference has too often been overlooked or ignored even when the resulting distortion is critical or even fatal, as in quantitative analyses of protein secondary structure, because the water has been impossible to measure or eliminate. Therefore, a new chemometric method was devised that corrects spectra of materials in KBr disks by mathematically eliminating the water interference. A new concept termed the Beer-Lambert law absorbance ratio (R-matrix) model was augmented with water concentration ratios computed via an exponential decay kinetic model of the water absorption process in KBr, which rendered the otherwise indeterminate system of linear equations determinate and thus possible to solve in a formal analytic manner. Consequently, the heretofore baffling KBr water elimination problem is now solved once and for all. Using the new formal solution, efforts to eliminate water interference from KBr disks in research will be defeated no longer. Resulting spectra of protein were much more accurate than attenuated total reflection (ATR) spectra corrected using the well-accepted Advanced ATR Correction Algorithm.

Genetic differentiation and patterns of gene flow of seven minority populations in Xinjiang / 西安交通大学学报(医学版)

Objective Genotype data of nine CODIS STR loci were gathered to examine the features of population differentiation and gene flow of seven Xinjiang minorities.Methods Heterozygosity,Nei's coefficient of genetic differentiation,Nei's genetic distance and Wright's F-statistics were calculated. Statistical tests using exact method were performed to measure the level of differentiation.Phylogenetic trees were constructed by Mega;AMOVA was processed by Arlequin.R-matrix model had been applied to describe the patterns of gene flow.Results It shows that average genetic heterogeneity for each population was above 0.7 with genetic differentiation coefficient below 2%.Statistical tests for population differentiation were significant for most of the loci.Phylogenetic analysis and AMOVA showed that all populations were divided into three main groups.The R-matrix analysis reflected that Uygur,Kirgiz and Ozbek had more amounts of gene flow than other populations,while the pattern of Hui was more isolated.Conclusion The seven minorities in Xinjiang are independent populations,while the level of differentiation is at average.The relationship in evolution is not far from each other,with wide gene flow.