Wiki as a tool for microbiology teaching, learning and assessment

INTRODUCTION

Evidence suggests that cooperative learning and peer-assessment fosters students' ability to work with others and may lead to better cognitive outcomes and higher achievement. This work aimed to assess the use of an online collaborative tool for the teaching/learning and assessment of Microbiology.

MATERIALS AND METHODS

A total of 144 students were grouped and assigned to create wiki entries as well as to peer review wikis created by colleagues (peer-assessment process) using the Wiki module from Moodle Virtual Learning Environment (MVLE). MVLE actions log was used for tracking students' activity.

RESULTS

The number of student's actions within wiki did not present a strong correlation with wiki scores, so it should not be used as a heavy evaluation parameter. The amount of work developed between members of the same group differed significantly, suggesting that final scores should be attributed individually. When peer-assessment process was implemented, the number of editing actions increased, suggesting that the peer-assessment strategy encourages the development of a better work. The vast majority of students execute the work in the last 10% of the period assigned for task development, which can be counter-productive for a truly collaborative work.

CONCLUSIONS

Wiki revealed to be a useful tool for Microbiology teaching/learning and assessment, promoting collaborative work, promoting virtual mobility and facilitating the real-time monitoring of the students' work. This pedagogical project promoted also the involvement of students in their assessment process, encouraging their critical sense and quest for Excellency.

Prostaglandin synthesis genes are differentially transcripted in normal and pyometra endometria of bitches

Pro-inflammatory stimuli, such as endotoxins released by Gram-negative bacteria, are potent stimulators of prostaglandin (PG) synthesis. The aim of this study was to evaluate the gene transcription pattern of PG synthesis enzymes in normal (anestrous, n = 6 and diestrous, n = 8) and pyometra (n = 7) endometria of bitches. Uteri were collected during routine ovariohysterectomy, processed for histopathological evaluation and uterine contents cultured. Gene transcription of COX-1, COX-2, mPGES-1 and PGF-synthase (PGFS) were evaluated by relative real-time PCR and normalized with the ribosomal protein L27 (RPL27) housekeeping gene. Normal uteri had no histological abnormalities and were negative for bacteriology. All pyometra uteri were hyperplasic and Escherichia coli was the only isolated bacterium. Except for COX-1, gene transcription was significantly higher in pyometra than in normal endometria. No significant differences in gene transcription were observed between normal diestrous and anestrous endometria. COX-2 gene transcription was 19 and 69 times higher in pyometra than in diestrous and anestrous endometria (p < 0.001), while PGFS gene transcription had a 3- and 600-fold increase in pyometra endometria compared to normal diestrous and anestrous endometria (p < 0.001). Gene transcription of mPGES-1 was 9 times higher in pyometra than in normal uteri (p < 0.01). Based on these results, we suggest that pyometra-associated E. coli endotoxin release stimulates the up-regulation of COX-2 PGFS and mPGES-1 gene transcription in the endometrium.

Blood COX-2 and PGES gene transcription during the peripartum period of dairy cows with normal puerperium or with uterine infection

In the dairy cow, puerperal uterine intra-luminal concentrations of PGE(2) are related to the establishment and severity of uterine infections. Here we evaluated whether the blood concentrations of PGE(2) and the gene transcription profiles of enzymes involved in its synthesis (cyclooxygenase-2 and prostaglandin E synthase) could be used as markers of predisposition and/or presence of puerperal uterine infections. We also studied the relationship between the endocrine status and the leukocyte profiles around parturition and the transcription patterns of the genes. Finally, we have characterized the in vitro gene transcription and expression response to a challenge of LPS. Gene transcription profiles, quantified by real-time PCR, were similar in normal puerperium and metritis/endometritis cows, indicating that they are not suitable markers of predisposition to/presence of puerperal uterine infections. Transcription decreased from 2 weeks before parturition until parturition, when a minimum was attained, and then increased during the first week postpartum. The lowest gene transcription, at parturition, was coincidental with the highest total leukocytes, polymorphonuclear neutrophils and CD14 positive cell numbers. It is suggested that by this mechanism, a large number of PMN can be recruited into the uterus after parturition, avoiding an excessive acute inflammatory response. The lowest gene transcription was also coincidental with the surge in cortisol concentrations, indicating that this hormone plays a main immunomodulatory role around parturition. Gene transcription was significantly greater after stimulation with LPS than in non-stimulated blood. We suggest that this PGE(2) producing cells might arrive to the uterine lumen, contributing to the local PGE(2) concentrations and mediating the inflammatory response.

Genomic characterization of Arcanobacterium pyogenes isolates recovered from the uterus of dairy cows with normal puerperium or clinical metritis

Arcanobacterium pyogenes is considered to be the most relevant bacterium involved in the establishment of puerperal uterine infection in cattle due to its persistence in utero, resistance to treatment and synergic action with Gram negative anaerobes. Once the infection is established, A. pyogenes is responsible for the persistence of the infection. The objective of this study was to characterize A. pyogenes field isolates recovered from the uterus of cows with either normal puerperium or clinical metritis, in an attempt to identify factors that might be associated with the establishment and persistence of the disease. This characterization was based on BOX-PCR typing and on screening of eight virulence factor genes (plo, nanP, nanH, cbpA, fimA, fimC, fimE, fimG) by conventional PCR. Finally, a relationship between clonal types, virulence factors and presence of disease was investigated. A. pyogenes clonal types identified from isolates recovered from the uterus of postpartum dairy cows differed among herds. Although some clonal types were strictly associated with the development of clinical metritis, others were identified from isolates recovered from normal puerperium and clinical metritis cows. Moreover, the presence of the eight virulence factor genes was not related with the ability to induce clinical metritis, suggesting that the type of A. pyogenes may not be a determinant factor in the development of the disease. We suggest that host intrinsic factors, the synergism between A. pyogenes and other bacteria and the differential gene expression of virulence factor genes may play a more relevant role in the establishment of puerperal uterine infections.

Phonological processing skills in speech and language impaired children

Phonological processing has been shown by many researchers to be strongly related to the acquisition of reading and spelling skills. Children with speech and language impairment appear to be at increased risk for phonological processing problems and hence literary difficulties. However, not all children with speech and language impairment experience difficulties: the literature is not clear as to which groups of speech and language impaired children are most severely affected nor which aspects of phonological processing are most likely to be impaired. Rigorous subject selection was employed to compare the performance of four groups of 20 children, aged approximately 6 years: speech-impaired (Speech); language-impaired (Language); speech and language impaired (Mixed); and children with normally developing language (Normal), by use of a battery of phonological processing tasks. The results supported the research that has shown speech and language impaired children to have weaker phonological processing skills than the general population. All the subjects in this sample appeared to be at risk: the Mixed children demonstrated the most difficulty, followed by the Language group, with the Normal group performing the best. Whilst the Speech group as a whole performed significantly more poorly than the Normal group, it consisted of two levels of performance which, on post hoc analysis were shown to relate to the pattern of speech impairment exhibited by the child.