The central notionof thisthesisis repetitionsin words. We studyproblemsrelated to contiguous repetitions. More specifically we will consider repeating scattered subwords of non-primitive words, i.e. words which are complete repetitions of other words. We will present inequalities concerning these occurrences as well as giving apartial solutionto an openproblemposedby Salomaaet al. We will characterize languages, whichare closed under the operation ofduplication, thatis repeating any factor of a word. We alsogive newbounds onthe number of occurrencesof certain types of repetitions of words. We give a solution to an open problem posed by Calbrix and Nivat concerning regular languages consisting of non-primitive words. We alsopresentsomeresultsregarding theduplication closureoflanguages,among which a new proof to a problem of Bovet and Varricchio.

Knowledge of phylogenetic relationships among taxa is essential for comparative and evolutionary genomic research. Here, we report reconstruction of the phylogenetic tree of the genus Gossypium containing cultivated cottons of importance in agriculture by using variation of nuclear repetitive DNA sequences. Genomic DNA was isolated from 87 available accessions of 35 species representing all eight basic genome groups of the genus Gossypium and analyzed to infer phylogeny of the genus and genome origin of its polyploid species. Twenty-two interspersed repeated sequence clones derived from G. hirsutum, each representing a repeated sequence family, were hybridized to the genomic DNA of the 35 species, respectively. Southern hybridization showed that 15 of the repetitive DNA sequences could be detected in all of the eight diploid genome groups, five were A genome-specific, and two were detected in some of the non D-genome groups. A total of 642 major restriction bands of repeated sequences were used for phylogenetic analysis of the species. A phylogenetic tree of the species was constructed, based on the parsimony method and evaluated by the bootstrap approach. The tree was consistent with those previously constructed with different methods in major clades in which the genealogical lineages of species are largely congruent with genome designations and geographical distribution; but significantly different branching among some of the species was observed. These results not only further confirm the previously phylogenetic analysis of the species and the utility of repetitive DNA sequences for phylogenetic analysis of the genus Gossypium, but also provide new insights into the phylogeny of the genus.

Bielefeld, Univ., Diss., 2001. / Computerdatei im Fernzugriff.

Bielefeld, Univ., Diss., 2001. / Computerdatei im Fernzugriff.

Bielefeld, University, Diss., 2001.

No description available.

The majority of gymnasts are young girls. Training hours required to meet competition demands are high and gymnasts begin serious training at a young age. Concerns regarding injury risk are substantial and may be the result of repeated high impact loads experienced during landings from dismounts, tumbling and vaulting. There is currently little information available to coaches regarding the quantity of training that is safe or not safe. The use of acceleration was tested for its efficacy for use in the field to examine risk factors for injury. Risk factors examined were loading and fatigue. Kinematics, ground reaction forces and acceleration were measured during landing from gymnastics skills and also pre- and post fatigue during landing from a vertical jump and a 35cm drop in the laboratory. A pilot study was performed in the field to examine accelerations during gymnastics skills pre- and post-training. Lower body kinematics of landing were notably different between gymnastics skills analysed. Joint positions at touchdown and range of motion available during landing due to these joint positions affect the ability to contribute to energy absorption. Peak ground reaction forces and peak accelerations measured at the pelvis showed significant differences between skills landing on both the hands and the feet. The peak acceleration during landing from gymnastics skills was positively correlated with the peak ground reaction force. A large variability stiffness during landing meant that an estimation of ground reaction force using simple modelling was not successful in improving the correlation. After a fatiguing jumping and landing task peak accelerations measured at the pelvis during landing were increased indicating the use of acceleration for identifying fatigue. Pilot field testing of acceleration during landing from gymnastics skills showed similar results to laboratory results. Pre- and post-training measurements showed no difference in peak accelerations during landing from the skills analysed. The training session completed was not demanding enough to induce enough fatigue to be seen in acceleration values Acceleration has potential to be used to quantify repeated loading and accumulative effects in gymnastics, as well as the presence of fatigue in gymnasts during training sessions.

The majority of gymnasts are young girls. Training hours required to meet competition demands are high and gymnasts begin serious training at a young age. Concerns regarding injury risk are substantial and may be the result of repeated high impact loads experienced during landings from dismounts, tumbling and vaulting. There is currently little information available to coaches regarding the quantity of training that is safe or not safe. The use of acceleration was tested for its efficacy for use in the field to examine risk factors for injury. Risk factors examined were loading and fatigue. Kinematics, ground reaction forces and acceleration were measured during landing from gymnastics skills and also pre- and post fatigue during landing from a vertical jump and a 35cm drop in the laboratory. A pilot study was performed in the field to examine accelerations during gymnastics skills pre- and post-training. Lower body kinematics of landing were notably different between gymnastics skills analysed. Joint positions at touchdown and range of motion available during landing due to these joint positions affect the ability to contribute to energy absorption. Peak ground reaction forces and peak accelerations measured at the pelvis showed significant differences between skills landing on both the hands and the feet. The peak acceleration during landing from gymnastics skills was positively correlated with the peak ground reaction force. A large variability stiffness during landing meant that an estimation of ground reaction force using simple modelling was not successful in improving the correlation. After a fatiguing jumping and landing task peak accelerations measured at the pelvis during landing were increased indicating the use of acceleration for identifying fatigue. Pilot field testing of acceleration during landing from gymnastics skills showed similar results to laboratory results. Pre- and post-training measurements showed no difference in peak accelerations during landing from the skills analysed. The training session completed was not demanding enough to induce enough fatigue to be seen in acceleration values Acceleration has potential to be used to quantify repeated loading and accumulative effects in gymnastics, as well as the presence of fatigue in gymnasts during training sessions.

Proefschrift Universiteit van Amsterdam. / Met lit. opg. - Met samenvatting in het Nederlands.

Abstract The genetic structure at different spatial scales and growing habitats was studied on Silene tatarica, using AFLP and microsatellite markers. S. tatarica is a rare perennial plant occurring along riverbanks and shores of two annually flooding rivers in Finland. Regional scale analysis based on AFLP fragment analysis showed that at Oulanka River population structure represented mostly classical metapopulation model. In general, colonization-extinction processes had an important role, dispersal between subpopulations was limited and genetic differentiation was independent of geographic location. The same subpopulations were partly used to study spatial genetic structuring within subpopulations. Spatial autocorrelation revealed clear spatial genetic structure in each subpopulation. Paternity analysis in an isolated subpopulation showed small amounts of inbreeding, restricted seed dispersal and pollen flow through the subpopulation. Factors affecting the creation and maintenance of spatial genetic structure within subpopulation were most likely colonization events and restricted seed dispersal. The impact of river regulation on the genetic structure of populations was studied by comparing results from Oulanka River to the results obtained from second main growing area, Kitinen River. Oulanka River is a natural river system, whereas Kitinen is a regulated river. The overall regional scale studies did not indicate major differences between river systems. There were some clear population genetic differences between rivers but there were no clear evidence that those would have been caused by river regulation. More likely differences were related to the marginal location of Kitinen population at the edge of the distribution range. Studies indicated that regardless of the species rarity in Finland, active management measures are not currently needed in either S. tatarica growing area. Species specific microsatellite loci were isolated to complement AFLP studies. During the microsatellite isolation, an interesting amplification pattern was detected and studied further. It was suggested that there were repetitive areas within genome containing microsatellites resulting in unusual amplification. The most likely explanation for this phenomenon would be transposable elements containing proto-microsatellite areas. The microsatellites isolated could have evolved mostly from those proto-microsatellites.