The quadratic spinor Lagrangian is equivalent to the teleparallel theory

The quadratic spinor Lagrangian is shown to be equivalent to the teleparallel / tetrad representation of Einstein's theory. An important consequence is that the energy-momentum density obtained from this quadratic spinor Lagrangian is essentially the same as the ``tensor'' proposed by Moller in 1961.Comment: 10 pages, RevTe

Sensitivity analysis by the adjoint chemistry transport model DRAISfor an episode in the Berlin Ozone (BERLIOZ) experiment

International audienceThe Berlin Ozone Experiment (BERLIOZ) was carried out in summer 1998. One of its purposes was the evaluation of Chemistry Transport Models (CTM). CTM KAMM/DRAIS was one of the models considered. The data of 20 July were selected for evaluation. On that day, a pronounced ozone plume developed downwind of the city. Evaluation showed that the KAMM/DRAIS model is able to reproduce the meteorological and ozone data observed, except at farther distances (60?80 km) downwind of the city. In that region, the DRAIS model underestimates the measured ozone concentrations by 10?15 ppb, approximately. Therefore, this study was conducted to detect possible reasons for this deviation. A comprehensive sensitivity analysis was carried out to determine the most relevant model parameters. The adjoint DRAIS model was developed for this purpose, because for this study the application of this model is the most effective method of calculating the sensitivities. The least squares of the measured and simulated ozone concentrations between 08:00 UTC and 16:00 UTC at two stations 30 km and 70 km downwind of the city centre were chosen as distance function. The model parameters considered in this study are the complete set of initial and boundary species concentrations, emissions, and reaction rates, respectively. A sensitivity ranking showing the relevance of the individual parameters in the set is determined for each parameter set. In order to find out which modification in the parameter sets most reduces the cost function, simplified 4-D data assimilation was carried out. The result of this data assimilation shows that modifications of the reaction rates provide the best agreement between the measured and the simulated ozone concentrations at both stations. However, the modified reaction rates seem to be unrealistic for the whole simulation period. Therefore, the good agreement should not be overestimated. The agreement is still acceptable when the parameters in the other sets are modified together. The investigation demonstrates that an analysis of this type can help to explain inconsistencies between observations and simulations. But in the case considered here the inconsistencies cannot be explained by an error in only one parameter set

Enhancing a Permanent Sample Plot System in Natural Forests

Permanent sample plots (PSPs) provide the basis for growth models and thus determine the quality of inferences made from decision support systems for forest management. Existing plots may have been adequate in the past, but changing needs and possibilities may have made data suboptimal for present demands. Funds for the establishment of additional plots are generally limited, so supplementary sampling should be based on an optimal sampling strategy employing prior information. This case study in south-east Queensland used topoclimatic strata and existing inventory data to identify where additional PSPs should be established, so as to increase the geographical and silvicultural range of the growth data collected. Some existing PSPs in areas considered over-sampled may be abandoned

The effect of three different insoles on ankle movement variability during walking in athletes with functional ankle instability.

Increased ankle movement variability has been reported in people with functional ankle instability (FAI). The purpose of this study was to investigate the effect of textured insole, lateral wedge, and textured lateral wedge insole on ankle movement variability during walking in athletes with FAI. Twenty-one athletes diagnosed with FAI participated in this before-after study. Kinematic data were collected during four conditions (5 repeated trials per condition): (1) flat ethylene-vinyl acetate (EVA) insole, (2) textured flat EVA insole, (3) prefabricated lateral heel and sole wedge insole, and (4) textured lateral heel and sole wedge. The analysis of ankle movement variability was conducted during stance phase and 200 ms before initial contact to 200 ms after initial contact. The coefficient of multiple correlations (CMC) was calculated to investigate pattern variability and intraclass correlation (ICC) was used to investigate variability at the points of interest. In terms of pattern variability, wearing textured lateral wedge increased CMC compared to other insoles. However, statistically significant differences were observed only in the frontal plane during stance phase ( < 0.05). In terms of variability at the points of interest, in the frontal plane and in all points of interest, wearing textured lateral wedge increased ICC compared to other insoles. The effects of other insoles on ankle movement variability were inconsistent. The results of this study showed that textured insole has the potential to decrease variability and the use of texture with lateral wedge may more improve variability in athletes with FAI

Mass and Spin of Poincare Gauge Theory

We discuss two expressions for the conserved quantities (energy momentum and angular momentum) of the Poincar\'e Gauge Theory. We show, that the variations of the Hamiltonians, of which the expressions are the respective boundary terms, are well defined, if we choose an appropriate phase space for asymptotic flat gravitating systems. Furthermore, we compare the expressions with others, known from the literature.Comment: 16 pages, plain-tex; to be published in Gen. Rel. Gra

Dirac spinor fields in the teleparallel gravity: comment on "Metric-affine approach to teleparallel gravity"

We show that the coupling of a Dirac spinor field with the gravitational field in the teleparallel equivalent of general relativity is consistent. For an arbitrary SO(3,1) connection there are two possibilities for the coupling of the spinor field with the gravitational field. The problems of consistency raised by Y. N. Obukhov and J. G. Pereira in the paper {\it Metric-affine approach to teleparallel gravity} [gr-qc/0212080] take place only in the framework of one particular coupling. By adopting an alternative coupling the consistency problem disappears.Comment: 8 pages, Latex file, no figures, to appear in the Phys. Rev. D as a Commen