Comparative analysis of more than 3000 sequences reveals the existence of two pseudoknots in area V4 of eukaryotic small subunit ribosomal RNA

The secondary structure of V4, the largest variable area of eukaryotic small subunit ribosomal RNA, was re-examined by comparative analysis of 3253 nucleotide sequences distributed over the animal, plant and fungal kingdoms and a diverse set of protist taxa. An extensive search for compensating base pair substitutions and for base covariation revealed that in most eukaryotes the secondary structure of the area consists of 11 helices and includes two pseudoknots. In one of the pseudoknots, exchange of base pairs between the two stems seems to occur, and covariation analysis points to the presence of a base triple. The area also contains three potential insertion points where additional hairpins or branched structures are present in a number of taxa scattered throughout the eukaryotic domain.

Hierarchical cluster analysis of emotional concerns and personality characteristics in a freshman population

An investigation was conducted to examine correlates of emotional concerns and personality characteristics in a general freshman population. The scores were analysed using agglomerative and divisive hierarchical clustering methods. The results indicate the presence of a coherent group which concerns emotional factors, and show a distinct user group strongly related to the first group. The data do not determine the importance of various personality factors in influencing emotional concerns.

Visco-elastic properties of four currently used tissue conditioners

About 60% of complete denture wearers experience a mostly painless inflammation of the palatal mucosal membrane. Especially prosthetic trauma and Candida albicans infection are assumed as aetiological factors. The treatment can be prosthetic or medicamentous, dependent on the cause. In this connection tissue conditioners could be very effective by their visco-elastic properties. Four tissue conditioners have been examined (Coe Comfort, FITT, Ivoseal, Visco Gel) for their impression softness and elastic recovery. All tests have been done on 20 mm specimens. The length of the specimens was measured during a 10 min compression and a 60 min relaxation. Eight ageing times have been taken into consideration. From the results large differences appear between the various tissue conditioners. Two main groups can be distinguished. FITT and Ivoseal are harder materials, whereas Coe Comfort and Visco Gel are softer. The ageing time has a clear hardening influence especially on Visco Gel. Visco Gel appears to be the best tissue conditioner by its relative plasticity during the first hours and its elastic behaviour during a longer ageing period. The clinical relevance of these materials is certainly not proved by this study. Further research will show this.

Active anterior rhinomanometry in pre- and postoperative evaluation, use of Broms' mathematical model

The authors studied the value of the Broms' mathematical model for active anterior rhinomanometry in a pathological population. They compared all different variables of a pathological group with a normal group and found significant differences for v0, v2 and R. There existed no difference between the means of v0 before and after surgery. There existed, however, a strongly positive correlation between the expiration and inspiration value. The influence of surgery was always significant for the variables v1, v2, v3 and R. Furthermore, the absolute deviation between the computed values and the recorded values tended to be very small. So, the authors concluded that rhinomanometry is a valuable aid in judging pre- and postoperative results.

Search for the relationship between interrupted university attendance of first year students and some psychosocial factors

Eight hundred and seventy-four freshmen underwent a structured interview to study the relationship of some psychosocial factors to interrupted university attendance. The scores were measured using the SPSS computer package. The scores indicate negative significant relationships between interrupted university attendance and satisfactory housing, own study choice, study motivation, campus participation and irregular alcohol consumption. The results demonstrate a positive significant relationship between withdrawal and the distance from the university.