The assessment of size in fossil felidae

Estimations of body size in fossil vertebrates depend on establishing the relationships between body mass, overall length or some measure of stature and measurements taken on skeletal elements in living relatives or close proxies. However, most osteological collections lack information on body size for individual specimens, and published investigations usually fa11 back on summary data derived from the literature to plot against measurements taken directly on the skeletal material. The utility of such approaches beyond very general indications of size is open to question. In an effort to reduce these problems we attempt to establish some objective basis for using skeletal elements for the purpose of size estimation in the larger Felidae of the genus Panthera, using data for the jaguar, Panthera onca. We show that cranial length offers a good indication of overall size in the living animal, and that various other cranial dimensions correlate closely with that measurement, while individual teeth, despite their frequent occurrence in assemblages, show a looser relationship and therefore appear less useful for size estimations of fossil material than has been thought.Las estimaciones de la talla corporal en vertebrados fósiles depende de las relaciones establecidas entre el peso corporal, la longitud total o alguna medida de estatura tomada de los elementos esqueléticos de animales actuales emparentados o muy afines. Sin embargo, en muchas colecciones osteológicas falta información sobre la talla corporal de los ejemplares, de forma que las investigaciones publicadas usualmente recurren a datos sintetizados de la literatura que se relacionan con medidas tomadas directamente del material esquelético. La utilidad de estas aproximaciones más allá de indicaciones generales sobre la talla es discutible. En un esfuerzo de minimizar estos problemas intentamos establecer bases objetivas para el uso de los elementos esqueléticos con el propósito de estimar la talla de los grandes Felidae del género Panthera, utilizando los datos obtenidos del jaguar, Panthera onca. Se muestra que la longitud craneal ofrece una buena indicación de la talla total en los animales actuales, y que otras dimensiones craneales se correlacionan estrechamente con esta medida, mientras que los dientes aislados, a pesar de su hallazgo frecuente en las asociaciones fósiles, muestra una menor correlación y por lo tanto es menos útil para la estimación de la talla en formas fósiles de lo que anteriormente se había pensado

Enhancing Nervous System Recovery through Neurobiologics, Neural Interface Training, and Neurorehabilitation.

After an initial period of recovery, human neurological injury has long been thought to be static. In order to improve quality of life for those suffering from stroke, spinal cord injury, or traumatic brain injury, researchers have been working to restore the nervous system and reduce neurological deficits through a number of mechanisms. For example, neurobiologists have been identifying and manipulating components of the intra- and extracellular milieu to alter the regenerative potential of neurons, neuro-engineers have been producing brain-machine and neural interfaces that circumvent lesions to restore functionality, and neurorehabilitation experts have been developing new ways to revitalize the nervous system even in chronic disease. While each of these areas holds promise, their individual paths to clinical relevance remain difficult. Nonetheless, these methods are now able to synergistically enhance recovery of native motor function to levels which were previously believed to be impossible. Furthermore, such recovery can even persist after training, and for the first time there is evidence of functional axonal regrowth and rewiring in the central nervous system of animal models. To attain this type of regeneration, rehabilitation paradigms that pair cortically-based intent with activation of affected circuits and positive neurofeedback appear to be required-a phenomenon which raises new and far reaching questions about the underlying relationship between conscious action and neural repair. For this reason, we argue that multi-modal therapy will be necessary to facilitate a truly robust recovery, and that the success of investigational microscopic techniques may depend on their integration into macroscopic frameworks that include task-based neurorehabilitation. We further identify critical components of future neural repair strategies and explore the most updated knowledge, progress, and challenges in the fields of cellular neuronal repair, neural interfacing, and neurorehabilitation, all with the goal of better understanding neurological injury and how to improve recovery

Optical fiber interferometer for the study of ultrasonic waves in composite materials

The possibility of acoustic emission detection in composites using embedded optical fibers as sensing elements was investigated. Optical fiber interferometry, fiber acoustic sensitivity, fiber interferometer calibration, and acoustic emission detection are reported. Adhesive bond layer dynamical properties using ultrasonic interface waves, the design and construction of an ultrasonic transducer with a two dimensional Gaussian pressure profile, and the development of an optical differential technique for the measurement of surface acoustic wave particle displacements and propagation direction are also examined

Inter-limb asymmetry during rehabilitation understanding formulas and monitoring the "magnitude" and "direction"

This article outlines how asymmetry can be used during the rehabilitation process for practitioners, and the importance of both the magnitude and direction of an inter-limb asymmetry

Tradeoff between short-term and long-term adaptation in a changing environment

We investigate the competition dynamics of two microbial or viral strains that live in an environment that switches periodically between two states. One of the strains is adapted to the long-term environment, but pays a short-term cost, while the other is adapted to the short-term environment and pays a cost in the long term. We explore the tradeoff between these alternative strategies in extensive numerical simulations, and present a simple analytic model that can predict the outcome of these competitions as a function of the mutation rate and the time scale of the environmental changes. Our model is relevant for arboviruses, which alternate between different host species on a regular basis.Comment: 9 pages, 3 figures, PRE in pres

Comparison of bilateral vs. unilateral-biased strength and power training interventions on measures of physical performance in elite youth soccer players

The aim of the present study was to compare the effects of bilateral and unilateral-biased strength and power training programs on measures of physical performance in male youth soccer players. Twenty-three elite youth players (age: 17.6 1.2 years) were randomly assigned to either a unilateral (n = 11) or a bilateral (n = 12) group, who completed a strength and power intervention, twice per week for 6-weeks. The unilateral group completed rear foot elevated split squats (RFESS), single leg countermovement jumps (SLCMJ), single leg drop jumps (SLDJ) and single leg broad jumps (SLBJ). The bilateral group intervention performed back squats, countermovement jumps (CMJ), drop jumps (DJ) and broad jumps (BJ). A 2 x 2 repeated measures ANOVA showed no between-group differences. However, within-group differences were evident. The bilateral training group showed significant (p < 0.05) improvements in back squat strength (d = 1.27; %Δ = 26.01), RFESS strength (d = 1.64; %Δ = 23.34), BJ (d = 0.76; %Δ = 5.12), 10 m (d = -1.17; %Δ = 4.29) and 30 m (d = -0.88; %Δ = 2.10) performance. The unilateral group showed significant (p < 0.05) improvements in RFESS strength (d = 1.40; %Δ = 33.29), SLCMJ on the left leg (d = 0.76; %Δ = 9.84), SLBJ on the left leg (d = 0.97; %Δ = 6.50), 10 m (d = -1.50; %Δ = 5.20), and 505 on the right leg (d = -0.78; %Δ = 2.80). Standardised mean differences showed that bilateral training favoured improvements in back squat strength and unilateral training favoured improvements in RFESS strength, SLDJ on the right leg and 505 on the right leg. These results show that although both training interventions demonstrated trivial to large improvements in physical performance, the notion of training specificity was evident with unilateral training showing greater improvements in unilateral test measures

Determination of Crystalline Content Gradients in Cold-Drawn Poly-L-Lactic Acid Films by DSC

Poly-L-lactic acid (PLLA) is a semi-crystalline, optically active, biodegradable, and biocompatible polymer that has been utilized extensively in biomedical applications as an implantable artificial cell scaffold material. In its crystalline form, PLLA is piezoelectric and it has been implicated in the enhancement of electromechanically induced osteogenesis in vivo. In its amorphous state, however, PLLA does not exhibit piezoelectricity. By uniaxially cold-drawing the polymer, PLLA can be endowed with varying degrees of piezoelectricity. It is important to understand the crystalline architecture of drawn PLLA so that the osteogenic potential imparted by piezoelectricity, if any, can be differentiated from the effects of sample crystallinity. In our work we investigate the induced crystallinity for samples of drawn PLLA at draw ratios between 1.0 and 5.5 by differential scanning calorimetry (DSC). As long-range molecular ordering occurs along the draw axis, we observe an increase in the average percent crystallinity up to a draw ratio of 5.0 and a slight decrease at a draw ratio of 5.5. More importantly, we observe significant heterogeneity in the crystalline content along the draw axis of standard dumbbells cut from PLLA and cold-drawn to representative draw ratios of 2.5 and 4.0. On average, the highest percent crystallinity occurs nearest the dumbbell center, but the maximum crystallinity is independent of draw ratio. Therefore, the draw ratio should not be considered a semi-quantitative estimate of localized PLLA crystallinity and point-to-point analysis of crystallinity in PLLA samples is required for constructing scaffolds with enhanced cell growth properties