Identifying student profiles and their impact on academic performance in a Brazilian undergraduate student sample.

The recognition of the student profile provides strategic information for planning educational policies in the university environment. The aims of this study were to identify natural segmentation of freshman undergraduate dental students based on demographic, socioeconomic and educational variables, and to subsequently investigate their impact on academic performance of Brazilian undergraduate students. Cluster analysis (two-step algorithm) was used to segment students who entered dental school in the time period from 1999 to 2001 (n=158) into groups based on responses to a questionnaire completed by students at the time of the admission examination. Clustering analysis revealed three natural groups. Age, the parents' level of education, and performance on the first admission test were the most important variables for cluster segmentation. Cluster 1 (n=42; 26.6%) was characterized by female students with higher socioeconomic status and better previous educational indicators. Cluster 2 (n=62; 39.2%) represented disadvantaged socioeconomic profiles, with a predominance of females and older students. Cluster 3 (n=54; 34.2%) showed similar socioeconomic characteristics to cluster 1, except for male prevalence, higher age, and experiencing difficulty in the admission test. Clusters' academic performance was satisfactory in both overall course and course groups (grade point average of at least 7.0), with average ranging from 7.89 (SD=0.44) to 8.13 (SD=0.31) and 7.37 (SD=0.75) to 8.31(SD=0.26), respectively. Our findings provide encouraging evidence for the current context of equality of access to education and reveal the importance of financial support to maximize successful educational experiences of socioeconomically disadvantaged dental students.

Assessing perceived potential outcomes of prosthodontic treatment in partial and fully edentulous patients.

The aim was to develop an instrument to measure and to explore the perception of potential outcomes of prosthodontic treatment in partial and fully edentulous patients, including benefits, risks and consequences of non replacement of missing teeth. It was also aimed to assess the influence of clinical and socio-demographic variables on the perception of potential outcomes. Using a two-phase data collection (open-ended and closed-form), a scale was developed containing 41 statements to measure subject's perception scores in a 5-point Likert-type scale (1, strongly disagree; 2, disagree; 3, neutral; 4, agree; 5, strongly agree). In the second phase 126 partially or fully edentulous subjects were interviewed. Influence of age, gender and clinical variables on perceived outcomes were tested using one-way anova, independent t-test and two-way anova (general linear model). Respondents' mean age was 51.8 years (s.d.=12.3), and 74% were female. Cronbach's alpha coefficient of the scale and subscales ranged from 0.70 to 0.90. Patients' mean scores ranged from 2.37 to 4.88 (mean=4.25; s.d.=0.65), indicating that subjects tended to agree with the proposed affirmatives (scores 4 and 5). Perception scores were influenced by age, gender, edentulous spaces and use of prosthodontics. Older subjects, female, those with higher number of missing teeth and who have been previously treated had greater perception of benefits and risks of prosthodontic treatment. It was concluded that the proposed instrument was suitable for measuring subjects' perception of potential outcomes of prosthodontic treatment.

Detecting animal by-product intake using stable isotope ratio mass spectrometry (IRMS).

Sheep are used in many countries as food and for manufacturing bioproducts. However, when these animals consume animal by-products (ABP), which is widely prohibited, there is a risk of transmitting scrapie - a fatal prion disease in human beings. Therefore, it is essential to develop sensitive methods to detect previous ABP intake to select safe animals for producing biopharmaceuticals. We used stable isotope ratio mass spectrometry (IRMS) for 13C and 15N to trace animal proteins in the serum of three groups of sheep: 1 - received only vegetable protein (VP) for 89 days; 2 - received animal and vegetable protein (AVP); and 3 - received animal and vegetable protein with animal protein subsequently removed (AVPR). Groups 2 and 3 received diets with 30% bovine meat and bone meal (MBM) added to a vegetable diet (from days 16-89 in the AVP group and until day 49 in the AVPR group, when MBM was removed). The AVPR group showed 15N equilibrium 5 days after MBM removal (54th day). Conversely, 15N equilibrium in the AVP group occurred 22 days later (76th day). The half-life differed between these groups by 3.55 days. In the AVPR group, 15N elimination required 53 days, which was similar to this isotope's incorporation time. Turnover was determined based on natural 15N signatures. IRMS followed by turnover calculations was used to evaluate the time period for the incorporation and elimination of animal protein in sheep serum. The δ13C and δ15N values were used to track animal protein in the diet. This method is biologically and economically relevant for the veterinary field because it can track protein over time or make a point assessment of animal feed with high sensitivity and resolution, providing a low-cost analysis coupled with fast detection. Isotopic profiles could be measured throughout the experimental period, demonstrating the potential to use the method for traceability and certification assessments.

Changes in the water quality conditions of Kuwait's marine waters: Long term impacts of nutrient enrichment.

This work analyses a 30 year water quality data set collated from chemical analyses of Kuwait's marine waters. Spatial patterns across six sites in Kuwait Bay and seven sites located in the Arabian Gulf are explored and discussed in terms of the changing influences associated with point and diffuse sources. Statistical modelling demonstrated significant increases for dissolved nutrients over the time period. Kuwait marine waters have been subject to inputs from urban development, untreated sewage discharges and decreasing river flow from the Shatt al-Arab River. Chlorophyll biomass showed a small but significant reduction; the high sewage content of the coastal waters from sewage discharges likely favouring the presence of smaller phytoplankton taxa. This detailed assessment of temporal data of the impacts of sewage inputs into Kuwait's coastal waters establishes an important baseline permitting future assessments to be made as sewage is upgraded, and the river continues to be extracted upstream.