THE EFFECT OF STEP-HEIGHT ON THE KNEE ANGLES AND IN-SHOE PRESSURE DISTRIBUTIONS DURING STEP-AEROBICS

INTRODUCTION A recent trend in indoor exercise is step-aerobics. This form of aerobic exercise involves the rhythmic stepping up to and down from a fixed platform to the beat of the accompanying "pop" music. In the past, substantial research has been done on the kinematics of the climbing of actual architectural stairs (Andriacchi et al., 1980; McFayden and Winter, 1988; Laubenthal et al., 1972) but no studies, to date, have been done to explore the kinematics of this new fitness phenomenon. Therefore, the purpose of this investigation was to study the biomechanics of step aerobics. Specifically, the effect of the step-height on the knee angles and in-shoe pressure distributions of subjects performing step aerobics was evaluated. It was hoped that the results of this study could be used to help determine any possible biomechanical health concerns of participation in step aerobics

Microscopic cluster model for the description of (18O,16O) two-neutron transfer reactions

Excitation energy spectra and absolute cross-section angular distributions were measured for the 13C(18O,16O)15C two-neutron transfer reaction at 84 MeV incident energy. Exact finite-range coupled reaction channel calculations are used to analyse the data considering both the direct two-neutron transfer and the two-step sequential mechanism. For the direct calculations, two approaches are discussed: The extreme cluster and the newly introduced microscopic cluster. The latter makes use of spectroscopic amplitudes in the centre-of-mass reference frame, derived from shell-model calculations. The results describe well the experimental cross sections

Microscopic cluster model for the description of new experimental results on the C 13 (O 18, O 16) C 15 two-neutron transfer at 84 MeV incident energy

The C13(O18,O16)C15 reaction is studied at 84 MeV incident energy. Excitation energy spectra and absolute cross-section angular distributions for the strongest transitions are measured with good energy and angular resolutions. Strong selectivity for two-neutron configurations in the states of the residual nucleus is found. The measured cross-section angular distributions are analyzed by exact finite-range coupled reaction channel calculations. The two-particle wave functions are extracted using the extreme cluster and the independent coordinate scheme with shell-model derived coupling strengths. A new approach also is introduced, the microscopic cluster, in which the spectroscopic amplitudes in the center-of-mass reference frame are derived from shell-model calculations using the Moshinsky transformation brackets. This new model is able to describe well the experimental cross section and to highlight cluster configurations in the involved wave functions

Hidden Overburden of Female-Headed Households in Guar Bean Production: Zimbabwean Experience

The study was done on a guar bean-growing project in Makachi area, Zimbabwe. The study objectives were to determine ownership of resources, time spent on production and access to information by male-headed and female-headed households. Data collection and analysis were based on the FAO Gender Analysis Framework. Results showed that male-headed households had more ownership of resources and spent less time on production; access to information was equal; female-headed households allocated a greater proportion of their land to guar bean production and matched their male counterparts in the mean yield. While inter-household exchanges helped female-headed households access draft power and farming equipment, obligations associated with these exchanges were found to be a source of overburden to female-headed households

Estimation of the hydraulic parameters of unsaturated samples by electrical resistivity tomography

In situ and laboratory experiments have shown that electrical resistivity tomography (ERT) is an effective tool to image transient phenomena in soils. However, its application in quantifying soil hydraulic parameters has been limited. In this study, experiments of water inflow in unsaturated soil samples were conducted in an oedometer equipped to perform three-dimensional electrical measurements. Reconstructions of the electrical conductivity at different times confirmed the usefulness of ERT for monitoring the evolution of water content. The tomographic reconstructions were subsequently used in conjunction with a finite-element simulation to infer the water retention curve and the unsaturated hydraulic conductivity. The parameters estimated with ERT agree satisfactorily with those determined using established techniques, hence the proposed approach shows good potential for relatively fast characterisations. Similar experiments could be carried out on site to study the hydraulic behaviour of the entire soil deposi

Delivering multiple gene products in the brain from a single adeno-associated virus vector

For certain gene therapy applications, the simultaneous delivery of multiple genes would allow for novel therapies. In the case of adeno-associated virus (AAV) vectors, the limited packaging capacity greatly restricts current methods of carrying multiple transgene cassettes. To address this issue, a recombinant AAV (rAAV) vector was designed such that a furin proteolytic cleavage site (RKRRKR) was placed between the coding sequences of two genes (green fluorescent protein (GFP) and galanin), to allow cleavage of the chimeric protein into two fragments. In addition, these constructs contained the fibronectin secretory signal sequence that causes the gene products to be constitutively secreted from transduced cells. In vitro studies show that after transfection of HEK293 cells, the appropriate cleavage and constitutive secretion occurred regardless of the order of the genes in the transgene cassette. In vivo, infusion of rAAV vectors into the piriform cortex resulted in both GFP expression and significant galanin attenuation of kainic acid-induced seizure activity. Thus, the present results establish the utility of a proteolytic approach for the expression and secretion of multiple gene products from a single AAV vector transgene cassette

Adeno-associated virus-mediated expression and constitutive secretion of NPY or NPY13-36 suppresses seizure activity in vivo

Neuropeptide Y (NPY) is a 36-amino-acid peptide that attenuates seizure activity following direct infusion or adeno-associated virus (AAV)-mediated expression in the central nervous system. However, NPY activates all NPY receptor subtypes, potentially causing unwanted side effects. NPY13-36 is a C-terminal peptide fragment of NPY that primarily activates the NPY Y2 receptor, thought to mediate the antiseizure activity. Therefore, we investigated if recombinant adeno-associated virus-mediated expression and constitutive secretion of NPY or NPY13-36 could alter limbic seizure sensitivity. Rats received bilateral piriform cortex infusions of AAV vectors that express and constitutively secrete full-length NPY (AAV-FIB-NPY) or NPY13-36 (AAV-FIB-NPY13-36). Control rats received no infusion, as we have previously shown that vectors expressing and secreting reporter genes like GFP (AAV-FIB-EGFP), as well as vectors expressing peptides that lack secretion sequences (AAV-GAL) have no effect on seizures. One week later, all animals received kainic acid (10 mg kg−1, intraperitoneally), and the latencies to wet dog shakes and limbic seizure behaviors were determined. Although both control and vector-treated rats developed wet dog shake behaviors with similar latencies, the latencies to class III and class IV limbic seizures were significantly prolonged in both NPY- and NPY13-36-treated groups. Thus, AAV-mediated expression and constitutive secretion of NPY and NPY13-36 is effective in attenuating limbic seizures, and provides a platform for delivering therapeutic peptide fragments with increased receptor selectivity

Location Dependent Dirichlet Processes

Dirichlet processes (DP) are widely applied in Bayesian nonparametric modeling. However, in their basic form they do not directly integrate dependency information among data arising from space and time. In this paper, we propose location dependent Dirichlet processes (LDDP) which incorporate nonparametric Gaussian processes in the DP modeling framework to model such dependencies. We develop the LDDP in the context of mixture modeling, and develop a mean field variational inference algorithm for this mixture model. The effectiveness of the proposed modeling framework is shown on an image segmentation task

Design of a Trans-Horizon radio link for ultra high and super high frequencies

Cost considerations and availability of frequencies condition the feasibility of links at distances in which there is no line of sight between antennas. These trans-horizon links require precise design procedures to determine whether the intensity of the signal and its noise ratio allow reception with reasonable quality. The present work describes a procedure for radio electric link calculation to transmit voice and data signals through bandwidth at ultra high and super high frequencies.Presentado en el V Workshop Arquitectura, Redes y Sistemas Operativos (WARSO)Red de Universidades con Carreras en Informática (RedUNCI