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Selected AbstractsInfluence of different load models on gear crack path shapes and fatigue livesFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 5 2008S. PODRUG ABSTRACT A computational model for determination of the service life of gears with regard to bending fatigue at gear tooth root is presented. In conventional fatigue models of the gear tooth root, it is usual to approximate actual gear load with a pulsating force acting at the highest point of the single tooth contact. However, in actual gear operation, the magnitude as well as the position of the force changes as the gear rotates. A study to determine the effect of moving gear tooth load on the gear service life is performed. The fatigue process leading to tooth breakage is divided into crack-initiation and crack-propagation period. The critical plane damage model has been used to determine the number of stress cycles required for the fatigue crack initiation. The finite-element method and linear elastic fracture mechanics theories are then used for the further simulation of the fatigue crack growth. [source] High salt-treatment-induced Na+ extrusion and low salt-treatment-induced Na+ accumulation in suspension-cultured cells of the mangrove plant, Bruguiera sexangulaPLANT CELL & ENVIRONMENT, Issue 10 2001M. Kura-Hotta Abstract A suspension-cultured cell strain of the mangrove plant (Bruguiera sexangula) was established from a callus culture and maintained in an amino acid medium in the absence of NaCl. NaCl non-adapted cells were transferred to media containing 0,200 mm NaCl. The initial growth rate decreased gradually with increasing salt concentrations. However, at up to 150 mm NaCl, cell number growth at the highest point was almost the same as that at lower salt concentrations. Cells even continued to grow in the presence of 200 mm NaCl. Cells incubated in a medium containing 50 mm NaCl for 3 weeks accumulated Na+, while those incubated in 150 mm NaCl for 2 d showed only a transient increase in Na+ and Cl, concentrations. In the latter treatment, the intracellular concentration of Na+ returned to the original low level within 2 weeks. It took a longer time for Cl, to return to its original level. As a result, the Na+ and Cl, concentrations in cells cultured with 50 mm NaCl were much larger than those in cells cultured with 150 mm NaCl. The intracellular distribution of ions after transfer to the medium containing 150 mm NaCl was analysed by isolating the vacuoles. Treatment with amiloride, an inhibitor of the Na+/H+ antiporter, suppressed the recovery of Na+ to the original level in the cells. Treatment with 150 mm NaCl for 3 d stimulated the activities of both the vanadate-dependent H+ -ATPase and the Na+/H+ antiporter in the plasma membrane fraction. [source] Double child burial from sunghir (Russia): Pathology and inferences for upper paleolithic funerary practicesAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2004Vincenzo Formicola Abstract The double child burial from Sunghir (Russia) is a spectacular Mid Upper Palaeolithic funerary example dated to about 24,000 BP. A boy (Sunghir 2) and a girl (Sunghir 3), about 12,13 and 9,10 years old, respectively, were buried at the same time, head to head, covered by red ocher and ornamented with extraordinarily rich grave goods. Examination of the two skeletons reveals that the Sunghir 3 femora are short and exhibit marked antero-posterior bowing. The two femora do not show any asymmetry in the degree of shortening and bowing. Bowing affects the whole diaphysis and shows a regularly incurved profile, with the highest point at midshaft. Pathology is confined to the femora, and no other part of this well-preserved specimen shows abnormality. The isolated nature of the Sunghir 3 anomalies points to cases reported in the medical literature under the label of "congenital bowing of long bones" (CBLB). These are a group of rare conditions exhibiting localized, sometimes bilateral, bowing and shortening which are nonspecific and may result from different causes, including abnormalities of the primary cartilaginous anlage (i.e., the aggregation of cells representing the first trace of an organ). Localized ossification disturbances, possibly linked to a diabetic maternal condition, might explain the shortening and the coincidence of maximum midshaft curvature with the position of the primary ossification center, as well as the lack of involvement of other skeletal parts. This scenario, rather than other possibilities (early bilateral midshaft fracture, acute plastic bowing deformities, or faulty fetal posture), provides the most likely explanation for the Sunghir 3 femoral deformities. The intriguing combination of a pathological condition apparent since birth with a spectacular burial of unusually positioned young individuals of different sexes recalls significant aspects of the triple burial from the contemporary site of Dolní V,stonice (Moravia), evoking a patterned relationship between physical abnormality and extraordinary Upper Paleolithic funerary behavior. Am J Phys Anthropol, 2003. © 2003 Wiley-Liss, Inc. [source] Changes in Nasal Cavity Dimensions in Children and Adults by Gender and Age,THE LARYNGOSCOPE, Issue 8 2007Boles, aw K. Samoli, ski MD Abstract Objective: The aim of the study was to establish the dynamics of changes in the intranasal spaces of children and adults by gender and age. Materials and methods: Each side of the nasal cavity was evaluated separately in 366 healthy subjects 9 to 74 years old. The following acoustic rhinometry parameters were analyzed: 1) I-C, distance between the isthmus nasi (I) and the head of the inferior turbinate (C); 2) CA-I, cross-sectional area at the isthmus nasi; 3) CA-C, at the head of the inferior turbinate; and 4) CA-F, the highest point on the rhinometric curve between points I and C. Results: Before age 11 years, the intranasal spaces were slightly larger in girls than in boys. After age 11 years the nasal parameters were larger in boys than in girls. The growth rates before age 17 years were as follows: I-C: 0.073 cm/yr, 0.135 cm/yr, CA-F: 0.055 cm2/yr, 0.133 cm2/yr (P < .00001), and CA-C: 0.010 cm2/yr, 0.034 cm2/yr (P < .02) in girls and boys, respectively. In subjects older than 16 years, the mean values of I-C were 1.707 cm, 1.934 cm (P < .0001), and of CA-C, 0.493 cm2, 0.611 cm2 (P < .0001) in women and men, respectively, and changed slightly over the year. Conclusions: The parameters of intranasal spaces depend on age and gender. The dynamics of the changes is greater in boys than in girls and usually the growth is completed by the age of 16. After this age, nasal cavities are bigger in men than in women. [source] Anatomical development of urinary bladder during the fetal periodCLINICAL ANATOMY, Issue 7 2008O. Sulak Abstract The aim of this study was to determine the development, location, and size of the urinary bladder during the fetal period. The study was performed on 149 human fetuses between 9 and 40 weeks of gestation. The location of the urinary bladder with respect to transverse plane between the highest point of pubic symphysis and the sacral promontory and median sagittal plane was first determined. The dimensions and the angle of the urinary bladder were measured, and bladder shapes were determined. In addition, the edges of the vesical trigone were measured. There was no significant difference between sexes for any of the parameters (P > 0.05). A significant correlation was observed between all parameters and gestational age (P < 0.001). The urinary bladder was located above the transverse plane in most of the cases (83%) and in the median sagittal plane in every case. It was determined that the angle of bladder did not change and the mean value of the angle was 151° during the fetal period. Bladder was categorized into four different shapes (ellipsoid, round, cuboid, and triangular), and the most common shape found during the fetal period was cuboid. The vesical trigone was an isosceles triangle during the fetal period. The new data provided by this study will enable evaluation of the development of the fetal urinary bladder, and should be useful in several fields such as anatomy, fetopathology, medical imaging, obstetrics, and pediatric urology. Clin. Anat. 21:683,690, 2008. © 2008 Wiley-Liss, Inc. [source] | ||||||||||