EFFECT OF PERFORMANCE SPEED ON THE KINEMATICS AND KINETICS OF TWO TRUNK AND HIP STRENGTHENING EXERCISES

The aim of this work was to study the effect of speed on the sit-up (SU) and leg raising-lowering (LRL) exercise technique. Seventeen subjects volunteered to participate, performing at 3 cadences. Video 3D analysis was conducted and ground reaction forces were record. The anterior-posterior displacement of the centre of pressure (COP) and mean range of motion (ROM) for 6 angles were calculated. Results indicate that when SU speed increases, hip and knee ROM increase, while there is a decrease in the upper trunk flexion. In the LRL there is a decrease in the pelvic tilt and hip angle, and an increase in the knee angle. It seems that in higher speed exercises, subjects modified their technique to keep up with the cadence. Coaches and trainers should control the subjects’ technique during the execution of these high speed exercises

Global change and plant-ecosystem functioning in freshwaters

Freshwater ecosystems are of worldwide importance for maintaining biodiversity and sustaining the provision of a myriad of ecosystem services to modern societies. Plants, one of the most important components of these ecosystems, are key to water nutrient removal, carbon storage, and food provision. Understanding how the functional connection between freshwater plants and ecosystems is affected by global change will be key to our ability to predict future changes in freshwater systems. Here, we synthesize global plant responses, adaptations, and feedbacks to present-day and future freshwater environments through trait-based approaches, from single individuals to entire communities. We outline the transdisciplinary knowledge benchmarks needed to further understand freshwater plant biodiversity and the fundamental services they provide.Environmental Biolog

Direct construction of the effective action of chiral gauge fermions in the anomalous sector

The anomaly implies an obstruction to a fully chiral covariant calculation of the effective action in the abnormal parity sector of chiral theories. The standard approach then is to reconstruct the anomalous effective action from its covariant current. In this work we use a recently introduced formulation which allows to directly construct the non trivial chiral invariant part of the effective action within a fully covariant formalism. To this end we develop an appropriate version of Chan's approach to carry out the calculation within the derivative expansion. The result to four derivatives, i.e., to leading order in two and four dimensions and next-to-leading order in two dimensions, is explicitly worked out. Fairly compact expressions are found for these terms.Comment: 19 pages, revtex, no figures. Writing improved. (Refers to arXiv:0807.1696.

Gauge invariant derivative expansion of the effective action at finite temperature and density and the scalar field in 2+1 dimensions

A method is presented for the computation of the one-loop effective action at finite temperature and density. The method is based on an expansion in the number of spatial covariant derivatives. It applies to general background field configurations with arbitrary internal symmetry group and space-time dependence. Full invariance under small and large gauge transformations is preserved without assuming stationary or Abelian fields nor fixing the gauge. The method is applied to the computation of the effective action of spin zero particles in 2+1 dimensions at finite temperature and density and in presence of background gauge fields. The calculation is carried out through second order in the number of spatial covariant derivatives. Some limiting cases are worked out.Comment: 34 pages, REVTEX, no figures. Further comments adde

Selective area growth of a- and c-plane GaN nanocolumns by molecular beam epitaxy using colloidal nanolithography

Selective area growth of a-plane GaN nanocolumns by molecular beam epitaxy was performed for the first time on a-plane GaN templates. Ti masks with 150 nm diameter nanoholes were fabricated by colloidal lithography, an easy, fast and cheap process capable to handle large areas. Even though colloidal lithography does not provide a perfect geometrical arrangement like e-beam lithography, it produces a very homogeneous mask in terms of nanohole diameter and density, and is used here for the first time for the selective area growth of GaN. Selective area growth of a-plane GaN nanocolumns is compared, in terms of anisotropic lateral and vertical growth rates, with GaN nanocolumns grown selectively on the c-plan

Ordered gan/ingan nanorods arrays grown by molecular beam epitaxy for phosphor-free white light emission

The basics of the self-assembled growth of GaN nanorods on Si(111) are reviewed. Morphology differences and optical properties are compared to those of GaN layers grown directly on Si(111). The effects of the growth temperature on the In incorporation in self-assembled InGaN nanorods grown on Si(111) is described. In addition, the inclusion of InGaN quantum disk structures into selfassembled GaN nanorods show clear confinement effects as a function of the quantum disk thickness. In order to overcome the properties dispersion and the intrinsic inhomogeneous nature of the self-assembled growth, the selective area growth of GaN nanorods on both, c-plane and a-plane GaN on sapphire templates, is addressed, with special emphasis on optical quality and morphology differences. The analysis of the optical emission from a single InGaN quantum disk is shown for both polar and non-polar nanorod orientation

Broadband Acoustic Cloaking within an Arbitrary Hard Cavity

This paper reports the design, fabrication, and experimental validation of a broadband acoustic cloak for the concealing of three-dimensional (3D) objects placed inside an open cavity with arbitrary surfaces. This 3D cavity cloak represents the acoustic analogue of a magician hat, giving the illusion that a cavity with an object is empty. Transformation acoustics is employed to design this cavity cloak, whose parameters represent an anisotropic acoustic metamaterial. A practical realization is made of 14 perforated layers fabricated by drilling subwavelength holes on 1-mm-thick Plexiglas plates. In both simulation and experimental results, concealing of the reference object by the device is shown for airborne sound with wavelengths between 10 cm and 17 cm.W. W. K. and V. M. G.-C. contributed equally to this work. W. W. K., B. L., and J. C. C. acknowledge support by the National Basic Research Program of China (973 Program) (Grants No. 2010CB327803 and No. 2012CB921504), National Natural Science Foundation of China (Grants No. 11174138, No. 11174139, No. 11222442, No. 81127901, and No. 11274168), NCET-12-0254, a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions and a program supported by China Scholarship Council (CSC). W. W. K. was also supported by the program for outstanding Ph.D. students of Nanjing University. V. M. G.-C, F. C., and J. S.-D. acknowledge financial support from the U.S. Office of Naval Research under Grant No. N00014-12-1-0216 and from the Spanish Ministerio de Economia y Competitividad under Grant No. TEC2010-19751.Kan, W.; Garcia Chocano, VM.; Cervera Moreno, FS.; Liang, B.; Zou, X.; Yin, L.; Cheng, J.... (2015). Broadband Acoustic Cloaking within an Arbitrary Hard Cavity. Physical Review Applied. 3(6):064019-1-064019-9. doi:10.1103/PhysRevApplied.3.064019S064019-1064019-93

Measurements of long-range near-side angular correlations in sNN=5\sqrt{s_{\text{NN}}}=5TeV proton-lead collisions in the forward region

Two-particle angular correlations are studied in proton-lead collisions at a nucleon-nucleon centre-of-mass energy of $\sqrt{s_{\text{NN}}}=5$TeV, collected with the LHCb detector at the LHC. The analysis is based on data recorded in two beam configurations, in which either the direction of the proton or that of the lead ion is analysed. The correlations are measured in the laboratory system as a function of relative pseudorapidity, $\Delta\eta$, and relative azimuthal angle, $\Delta\phi$, for events in different classes of event activity and for different bins of particle transverse momentum. In high-activity events a long-range correlation on the near side, $\Delta\phi \approx 0$, is observed in the pseudorapidity range $2.0<\eta<4.9$. This measurement of long-range correlations on the near side in proton-lead collisions extends previous observations into the forward region up to $\eta=4.9$. The correlation increases with growing event activity and is found to be more pronounced in the direction of the lead beam. However, the correlation in the direction of the lead and proton beams are found to be compatible when comparing events with similar absolute activity in the direction analysed.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-040.htm