Reducing the Dispersion of Periodic Structures with Twist and Polar Glide Symmetries.

In this article, a number of guiding structures are proposed which take advantage of higher symmetries to vastly reduce the dispersion. These higher symmetries are obtained by executing additional geometrical operations to introduce more than one period into the unit cell of a periodic structure. The specific symmetry operations employed here are a combination of p-fold twist and polar glide. Our dispersion analysis shows that a mode in a structure possessing higher symmetries is less dispersive than in a conventional structure. It is also demonstrated that, similar to the previously studied Cartesian glide-symmetric structures, polar glide-symmetric structures also exhibit a frequency independent response. Promising applications of these structures are leaky-wave antennas which utilize the low frequency dependence.

Phylogenetic analyses indicate that the 19'Hexanoyloxy-fucoxanthin-containing dinoflagellates have tertiary plastids of haptophyte origin.

The three anomalously pigmented dinoflagellates Gymnodinium galatheanum, Gyrodinium aureolum, and Gymnodinium breve have plastids possessing 19'-hexanoyloxy-fucoxanthin as the major carotenoid rather than peridinin, which is characteristic of the majority of the dinoflagellates. Analyses of SSU rDNA from the plastid and the nuclear genome of these dinoflagellate species indicate that they have acquired their plastids via endosymbiosis of a haptophyte. The dinoflagellate plastid sequences appear to have undergone rapid sequence evolution, and there is considerable divergence between the three species. However, distance, parsimony, and maximum-likelihood phylogenetic analyses of plastid SSU rRNA gene sequences place the three species within the haptophyte clade. Pavlova gyrans is the most basal branching haptophyte and is the outgroup to a clade comprising the dinoflagellate sequences and those of other haptophytes. The haptophytes themselves are thought to have plastids of a secondary origin; hence, these dinoflagellates appear to have tertiary plastids. Both molecular and morphological data divide the plastids into two groups, where G. aureolum and G. breve have similar plastid morphology and G. galatheanum has plastids with distinctive features.

Automated system for purification of dye-terminator sequencing products eliminates up-stream purification of templates.

The quality of sequencing results is to a large extent determined by the purity of the template and the purification of the sequencing products. Fragments that can act as unspecific primers and templates are removed before gel analysis, and the background of unspecific signals is highly reduced. Purification of the sequencing products is needed to remove salts, nucleotides, proteins and template DNA that can interfere with the gel separation. We have developed a product, DYNAPURE Dye Terminator Removal, that specifically isolates and purifies the sequencing products in 10 min. The method is based on biotinylated sequencing primers and super-paramagnetic streptavidin beads. A PCR product is sequenced using a biotinylated sequencing primer, and the sequencing products are then bound to streptavidin beads in a 5-min reaction. The bead-DNA complexes are magnetically separated from the rest of the solution, and the remaining buffer constituents are washed away with TE buffer or with 70% ethanol. The whole procedure can be automated on liquid-handling robots fitted with a magnet station. The method eliminates purification of templates before cycle sequencing.

Rapid, universal method to isolate PCR-ready DNA using magnetic beads.

A magnetic bead-based system for DNA isolation utilizing monodisperse beads was tested with the aim of producing a general approach for PCR-ready DNA. This commercially available system was originally designed for isolating PCR-ready DNA from human whole blood. We tested diverse organisms belonging to the major groups: bacteria, fungi, algae, vascular plants and vertebrates. Optimization of sample amounts and lysis conditions was done using several types of tissue (fish epithelium, plant leaves, mammalian liver and muscle tissues, fungal fruit-bodies and mycelium). The standard lysis conditions used for blood could be applied with good results for most bacteria, algae and vertebrates, while plant leaves and fungal fruit-bodies had to be mechanically broken to obtain proper lysis. For vascular plants and some cyanobacteria, lysis by heating to 65 degrees C gave better DNA yields than standard lysis at room temperature. In all cases, DNA suitable for PCR was prepared in less than 30 min. The PCR products yielded 350 to 500 bases of DNA sequence (99% accurate) by direct manual or automated sequencing.

The current status of nursing informatics in undergraduate nursing programs: comparative case studies between Sweden and Australia.

During the last ten years, the inclusion of education in health information systems has assumed an important role in graduate programs for health professionals. More recently, attention has focused on undergraduate programs. Throughout the world schools of nursing, organisations and associations are addressing the issue of educational offerings in nursing informatics. This paper reports on the status of nursing informatics at undergraduate level. Nurse academics from Gävle and Lund in Sweden, and from Melbourne and Sydney in Australia, took part in a survey of the respective nursing courses. The purpose of the study was to identify and describe examples of types of nursing informatics courses in Australia and Sweden. A convenient sample of academics were approached and interviewed. The results of the survey illustrate, in the schools surveyed, the slow emergence of nursing informatics into nursing curricula.

Low-dose antacids versus 400 mg cimetidine twice daily for reflux oesophagitis. A comparative, placebo-controlled, multicentre study.

Ninety-one patients with reflux oesophagitis were randomly allocated to treatment with one chewable antacid tablet (acid-neutralizing capacity, 30 mmol) four times daily, 400 mg cimetidine twice daily, or placebo. The study was double-blind, with a double-dummy technique. Endoscopy was performed before inclusion and after 8 weeks' treatment. Symptoms were recorded on diary cards and on visual analogue scales. Statistically significant healing of oesophagitis was achieved in all three treatment groups, but none of the active regimens were significantly superior to placebo. Symptoms were significantly reduced with both cimetidine and antacids compared with placebo. Patients taking antacids consumed significantly less extra antacids for pain relief and had significantly better global assessment score than patients taking cimetidine during the first and second half of the study, respectively. In conclusion, neither cimetidine nor antacids were significantly superior to placebo in healing of reflux oesophagitis. Both the active regimens were superior to placebo for symptomatic relief.

Low-dose antacids or cimetidine for duodenal ulcer?

In a double-blind, randomized, multicenter trial 150 consecutive outpatients with endoscopically verified duodenal ulcer were treated with either a low-dose antacid regimen (1 tablet q.i.d.; acid-neutralizing capacity, 120 mmol/day), or cimetidine (800 mg nocte). After 4 wk of treatment control gastroscopy showed ulcer healing in 54 of 76 patients (71.1%) in the antacid group, as compared with 58 of 74 patients (78.4%) in the cimetidine-treated group. The difference in healing rate of 7.3% (95% confidence interval, -6.5% to +21.1%) was not statistically significant. The symptomatic effect, measured as number of days and nights with ulcer pain, was also quite similar in the two treatment groups. However, the number of days with pain was significantly lower in the first week of treatment in the antacid group (p less than 0.01). Thus, the efficacy of a low-dose antacid tablet regimen approximated that of cimetidine (800 mg nocte) in the treatment of duodenal ulcer patients.