A METHOD OF IMPROVING THE MEASUREMENT OF KINEMATIC PARAMETERS ABOVE AND UNDER WATER IN SWIMMING START

The objectives of this study were to develop an improved method of measuring kinematic parameters of a swimmer at the start of a race from water entry through the initial glide in a seamless manner and to consider deceleration factors with reference to changes in the swimmer’s kinematic parameters during the start. Ten elite collegiate male swimmers participated in this study. To obtain accurate displacements of each reference point on a swimmer while avoiding interference from bubbles, waterproofed, super-luminosity LED markers were used. Additionally, a metallic frame (3 m × 2 m) and a nylon belt (6.1 m long with marks at intervals of 0.5 m) were used as calibration control points. Participants were asked to start from a starting block three times with their maximum effort and maintain a streamlined position without any kicking after water entry until they reached the 10-m point. The mean calibration error was 0.0046 m in the horizontal direction and 0.0047 m in the vertical direction across the measurement span (11 m × 6 m). This improved method enabled us to measure successive changes in the velocity and acceleration of the centre of mass both above water and following water entry

Cellular Dynamics of Double Fertilization and Early Embryogenesis in Flowering Plants

Flowering plants (angiosperms) perform a unique double fertilization in which two sperm cells fuse with two female gamete cells in the embryo sac to develop a seed. Furthermore, during land plant evolution, the mode of sexual reproduction has been modified dramatically from motile sperm in the early-diverging land plants, such as mosses and ferns as well as some gymnosperms (Ginkgo and cycads) to nonmotile sperm that are delivered to female gametes by the pollen tube in flowering plants. Recent studies have revealed the cellular dynamics and molecular mechanisms for the complex series of double fertilization processes and elucidated differences and similarities between animals and plants. Here, together with a brief comparison with animals, we review the current understanding of flowering plant zygote dynamics, covering from gamete nuclear migration, karyogamy, and polyspermy block, to zygotic genome activation as well as asymmetrical division of the zygote. Further analyses of the detailed molecular and cellular mechanisms of flowering plant fertilization should shed light on the evolution of the unique sexual reproduction of flowering plants

A Discovery of a Peculiar Pulsar in the Small Magellanic Cloud

We report on a peculiar X-ray binary pulsar IKT1 = RXJ0047.3-7312 observed with XMM-Newton in Oct. 2000. The X-ray spectrum is described by a two-component spectrum. The hard component has a broken power-law with respective photon indices of 0.2 and 1.8, below and above the break energy at 5.8 keV. The soft component can be modeled by a blackbody of kT = 0.6 keV. The X-ray flux shows a gradual decrease and periodic variations of about 4000 s. The averaged flux in 0.7-10.0 keV is 2.9x10^-12 ergs/cm^2/s, which is ~10 times brighter than that in a ROSAT observation in Nov. 1999. In addition to the 4000-s variation, we found coherent pulsations of 263 +/- 1 s. These discoveries strengthen the Be/X-ray binary scenario proposed by the ROSAT and ASCA observations on this source, and confirm that most of the hard sources in the Small Magellanic Cloud are X-ray binary pulsars. A peculiar property of this XBP is that the coherent pulsations are found only in the soft component, and the folded light curve shows a flat top shape with a sharp dip. We discuss the nature of this XBP focusing on the peculiar soft component.Comment: 5 pages, 5figures, Accepted for publication in PAS

Freeze dried bone matrix on rat critical size defect regeneration

Bone allografts are commonly used for bone regeneration. The aim of this study was evaluate the efficacy of a freeze dried bone matrix (FDBM) in critical size defect (CZD) rat calvaria. Eighteen Wistar female rats (body weight 150 ± 50 g) with CZD (5mm) were divided in two groups: group 1, using freeze dried bone matrix; and group 2, only with coagulum. All samples were evaluated on the 1st, 3rd and 6th weeks post-surgery by soft X-ray, histological and histometric studies. Soft X-ray results showed a radiolucent image with many irregular radiopaque areas. Histologically, bone regeneration was initiated from the 3rd week, when a thin layer of new woven bone could be seen adjacent to the matrix. At the 6th week, lamellar bone covered over half (61.8%) of the defect area. The lack of FDBM resorption allowed its incorporation to the new regenerated bone. This behavior is important in circumstances where it is necessary not only to stimulate bone regeneration but also increase the volume in affected areas, such as during the placement of dental implants. The results obtained in this research are encouraging for the use of freeze dried bone matrix as a bone graft material.Fil: Jammal, María Victoria. Universidad Nacional de Tucumán. Facultad de Odontología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Missana, Liliana Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Odontología; ArgentinaFil: Takabatake, Kiyofumi. Okayama University; JapónFil: Takagi, Shin. Okayama University; JapónFil: Nagatsuka, Hitoshi. Okayama University; Japó

Neurofibroma of the tongue: a case report.

A tumor of nerve origin is relatively rare in the oral region. We report a neurofibroma of the tongue observed in a 34-year-old woman.</p