Helen Dalton

Student evaluation of courses : what predicts satisfaction?

The main goals of course evaluations are to obtain student feedback regarding courses and teaching for improvement purposes and to provide a defined and practical process to ensure that actions are taken to improve courses and teaching. Of the items on course evaluation forms, the one that receives the most attention and consequently the most weight is the question, ‘Overall, I was satisfied with the quality of this course.’ However, no attention has been placed on examining the predictors of students being ‘satisfied with the quality of this course’ overall. This study attempts to address this gap. The findings show that while student characteristics and reasons for enrolling in a course are predictors of overall satisfaction, it is the evaluation questions that predict the majority of the variation in course satisfaction. The findings also reveal that faculty‐selected optional questions are stronger predictors of overall satisfaction than compulsory questions.

Molecular genetics of bacterial attachment and biofouling

Microbial adhesion to animate or inert surfaces is potentially mediated by nonspecific physical or specific ligand-receptor interactions. Growth and survival of the microbial community or biofilm then depends on adaptation to a series of changing environmental milieux. Within the realm of cell-cell interaction, recent advances suggest that flagella, fimbriae and other protein receptors are essential for bacterial attachment to surfaces. There has also been profound progress in the elucidation of genes and molecules necessary for bacterial attachments to surfaces and subsequent biofilm formation.

A biological assay for detection of heterogeneities in the surface hydrophobicity of polymer coatings exposed to the marine environment.

Minimally adhesive polymers are being developed as potential coatings for use in the marine environment. A ‘bioprobe’, the bacterium Psychrobacter sp. strain SW5, was employed to detect heterogeneities in substratum hydrophobicity at a micrometer level, rather than the millimeter level detected by traditional contact angle measurements. This novel assay was based on substratum‐induced shifts in bacterial morphology and was used to demonstrate that characteristics of these surfaces can be evaluated for maintenance of parameters such as low surface free energy as well as temporal stability when immersed in water. Immersion of developmental substrata in artificial seawater for up to 90d prior to testing with the bioprobe potentially affects the stability of the designed characteristics of the polymers. It is proposed that the shifts in cell and biofilm morphology results from changes influencing the surface hydrophobicity of the polymers. An unpredicted outcome of this testing was the detection of modifications to coatings inferred by the addition of filler particles. Exposure of coatings to the natural microbial community of seawater revealed colonization characteristics that substantiate the results obtained by using the bioindicator.

Detection, Isolation, and Characterization of Helicobacter Species from the Gastrointestinal Tract of the Brushtail Possum

ABSTRACT The presence of Helicobacter species in Australian marsupials was examined systematically using microscopy, culture, and PCR in different regions of the gastrointestinal tract (GIT) and in the liver of brushtail possums (BTPs) (Trichosurus vulpecula), a common Australian marsupial that feeds on eucalyptus leaves. The spatial distribution of Helicobacter species in the GIT sections also was examined microscopically in silver-stained sections and by fluorescent in situ hybridization (FISH) using a Helicobacter genus-specific probe. Helicobacter species were found colonizing the lower bowel of all BTPs studied. Good agreement was observed between the detection of Helicobacter species using culture and PCR, which was supported by the microscopic examination of silver-stained sections and FISH. The lower bowel of BTPs were colonized by one to three morphologically different (a comma-shaped species with no apparent flagella, a fusiform-shaped species entwined with periplasmic fibers and a bipolar sheathed flagella, and an S-shaped species with bipolar sheathed flagella) and potentially novel Helicobacter species, as well as in one case with a potentially novel Campylobacter species, which was a tightly coiled rod with bipolar unsheathed flagella. The isolation and characterization of these Helicobacter species in BTPs provides important information regarding the specific natural niche of these bacteria and their corelationship within their host, and it increases our understanding of the ecology of Helicobacter species.

Molecular Genetics of Bacterial Adhesion and Biofouling

It has been estimated that in natural environments ninety nine percent of all bacteria exist in biofilms, or at least reside at surfaces.6 To date, bacterial attachment or adhesion to both natural and artificial surfaces has been examined in many different contexts. These include attachment to inert (solid and agar) and animate (eukaryotic cells) surfaces. In the vast majority of cases little is known about how bacteria attach to these surfaces. Recent advances, particularly in the area of bacteria adhering to eukaryotic cells, have pointed to the importance of surface organelles and receptors in the attachment process. Following attachment, growth on solid surfaces results in the formation of a biofilm, and in most cases this contributes to biofouling. Advances in fluorescent microscopy and reporter gene-fusion technology have provided a means of detecting altered gene expression as it occurs during microbial growth at surfaces and within biofilms (see Chapter 12).