Home About us Contact
|
Home About us Contact | ||
|
|
||
Greatest Length (greatest + length)
Selected AbstractsWhat becomes of dental research trainees once they leave the Dental Research Institute?EUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 2 2008An analysis over 53 years Abstract The careers of 131 dental research trainees were followed (1954,2007) to establish whether and how they utilised their research training in keeping with clinical research workforce needs. The Dental Research Institute database was used to obtain trainee demographic, teaching and research outputs which were examined according to degree types: PhD (18); MSc (55); MDent (42) and dropout (16). Current careers show that 48% are in exclusive private practice and 15% in exclusive academia with further 15% practitioners having academic links via sessional teaching or research at a dental school. Most (63%) have remained in South Africa but emigration is high amongst the PhD and MSc groups. Forty-one per cent of the cohort is of age ,55 years and 16% <40 years old. The 131 trainees have published 2287 peer-reviewed journal papers over their careers: quantity of research output is skewed towards degree type (PhD) and individuals (10% trainees produced 65% of all publications). Recent trainees have little research experience prior to their training and a lower subsequent research output than earlier trainees. PhDs have participated in research for the greatest length of time (29.1 years). Academic teaching is heavily reliant on older and PhD trainees. It is proposed that a threshold of four publications be used to indicate minimum research skills and a period of formal academic teaching taken into account when advocating criteria to assess clinical research workforce requirements. [source] A simple model of river meandering and its comparison to natural channelsHYDROLOGICAL PROCESSES, Issue 1 2002Stephen T. Lancaster Abstract We develop a new method for analysis of meandering channels based on planform sinuosity. This analysis objectively identifies three channel-reach lengths based on sinuosity measured at those lengths: the length of typical, simple bends; the length of long, often compound bends; and the length of several bends in sequence that often evolve from compound bends to form multibend loops. These lengths, when normalized by channel width, tend to fall into distinct and clustered ranges for different natural channels. Mean sinuosity at these lengths also falls into distinct ranges. That range is largest for the third and greatest length, indicating that, for some streams, multibend loops are important for planform sinuosity, whereas for other streams, multibend loops are less important. The role of multibend loops is seldom addressed in the literature, and they are not well predicted by previous modelling efforts. Also neglected by previous modelling efforts is bank,flow interaction and its role in meander evolution. We introduce a simple river meandering model based on topographic steering that has more in common with cellular approaches to channel braiding and landscape evolution modelling than to rigorous, physics-based analyses of river meandering. The model is sufficient to produce reasonable meandering channel evolution and predicts compound bend and multibend loop formation similar to that observed in nature, in both mechanism and importance for planform sinuosity. In the model, the tendency to form compound bends is sensitive to the relative magnitudes of two lengths governing meander evolution: (i) the distance between the bend cross-over and the zone of maximum bank shear stress, and (ii) the bank shear stress dissipation length related to bank roughness. In our simple model, the two lengths are independent. This sensitivity implies that the tendency for natural channels to form compound bends may be greater when the banks are smoother. Copyright © 2002 John Wiley & Sons, Ltd. [source] Morpho-physical Recording of Bovine Conceptus (Bos indicus) and Placenta from Days 20 to 70 of PregnancyREPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2010AC Assis Neto Contents The study is based on 141 pregnant Bos indicus cows, from days 20 to 70 post-insemination. First, special attention was given to the macroscopically observable phenomena of attachment of the conceptus to the uterus, i.e. the implantation, from about days 20 to 30 post-insemination up to day 70, and placentome development by growth, vascularization and increase in the number of cotyledons opposite to the endometrial caruncles. Secondly, as for the conceptuses, semiquantitative, statistical analyses were performed of the lengths of chorio-allantois, amnion and yolk sac; and the different parts of the centre and two extremes of the yolk sacs were also analysed. Thirdly, the embryos/foetuses corresponding to their membranes were measured by their greatest length and by weight, and described by the appearance of external developmental phenomena during the investigated period like neurulation, somites, branchial arcs, brain vesicles, limb buds, C-form, pigmented eye and facial grooves. In conclusion, all the data collected in this study from days 20 to 70 of bovine pregnancy were compared extensively with corresponding data of the literature. This resulted in an ,embryo/foetal age-scale', which has extended the data in the literature by covering the first 8 to 70 days of pregnancy. This age-scale of early bovine intrauterine development provides model for studies, even when using slaughtered cows without distinct knowledge of insemination or fertilization time, through macroscopic techniques. This distinctly facilitates research into the cow, which is now being widely used as ,an experimental animal' for testing new techniques of reproduction like in vitro fertilization, embryo transfer and cloning. [source] Brain size of the lion (Panthera leo) and the tiger (P. tigris): implications for intrageneric phylogeny, intraspecific differences and the effects of captivityBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009NOBUYUKI YAMAGUCHI Intraspecific encephalization of the lion and the tiger is investigated for the first time using a very large sample. Using cranial volume as a measure of brain size, the tiger has a larger brain relative to greatest length of skull than the lion, the leopard and the jaguar. The Asian lion has a relatively much smaller brain compared with those of sub-Saharan lions, between which there are few differences. The Balinese and Javan tigers had relatively larger brains compared with those of Malayan and Sumatran tigers, even although these four putative subspecies occupy adjacent ranges in south-eastern Asia. Differences in brain size do not appear to correlate with any known differences in behaviour and ecology and, therefore, may reflect only chance differences in intrageneric and intraspecific phylogeny. However, captive-bred big cats generally have a reduced brain size compared with that of wild animals, so that an animal's life history and living conditions may affect brain size and, hence, functional or environmental explanations should be considered when linking brain size differences to intraspecific phylogenies. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 85,93. [source] | ||||||||||