The spatial model of Levene (1953) was examined in a finite population and compared to a temporal model. The spatial model was much more effective in retaining genetic variation in a finite population. Furthermore, the haploid spatial model was more effective in retaining genetic variation than the analogous diploid absolute dominance model. This is the opposite from that found for the temporal...

HIS paper is concerned with certain statistical problems which arise in conTnection with attempts to estimate fitnesses from the genotype frequency data produced by artificial populations in which rapid changes in genotype frequencies are taking place. The special situation of concern here is the one in which the investigator wishes to obtain several estimates of fitness, each taken from small ...

Many people believe that American biologist James Watson and English physicist Francis Crick discovered DNA in the 1950s. In reality, this is not the case. Rather, DNA was first identified in the late 1860s by Swiss chemist Friedrich Miescher. Then, in the decades following Miescher's discovery, other scientists--notably, Phoebus Levene and Erwin Chargaff--carried out a series of research effor...

This case is one of considerable rarity. The literature on pulmonary hamartomata is almost exclusively limited to the chrondromatous type, in which the cartilage is associated marginally and between fissures with various non-cartilaginous tissues. In these, muscle fibres do not occur very frequently. For example, in 31 cases reported by Rubin and Berkman (1952) strands of smooth muscle were an ...

Discovery Learning is a learning model that intend training spatial of thinking skills because in the process each student given opportunity to independent active role such as problem identification, data collecting, processing, looking for proof, until conclude acquisition makes them have ability solve problems material. The study aims determine effect on students skills. This research quasi-e...

PURPOSE Novel irradiation techniques are continuously introduced in radiotherapy to optimize the accuracy, the security and the clinical outcome of treatments. These changes could raise the question of discontinuity in dosimetric presentation and the subsequent need for practice adjustments in case of significant modifications. This study proposes a comprehensive approach to compare different t...

statement of problem: the extraction versus non-extraction debate is almost as old as the advent of orthodontic practice and up to now, this dilemma remains. recently, the american board of orthodontics (abo) has developed a method by the name of objective grading system (ogs) in order to evaluate the results of orthodontic treatment. aim: the aim of the present study was to evaluate and compar...