Knowledge, application and how about competence? Qualitative assessment of multiple-choice questions for dental students.

Background: Many medical schools train their faculty members to construct high cognitive level multiple choice questions (MCQs) that demand a great deal of analytical and critical thinking, application, and competence. The purpose of this study is to determine the cognitive levels of MCQs by using Moore's Expanded Outcomes Framework and to understand whether the quality of MCQs has an effect on students' assessment performance.Methods: Four trained faculty members analysed 100 randomly selected questions developed at the University Clinic of Dentistry (UCD) and 100 questions developed by the National Board of Dental Examinations (NBDE). Moore's framework was applied to assist the review process.Results: The majority of questions was at the level of declarative knowledge followed by questions at the level of procedural knowledge. The cognitive level of UCD questions from 2002 to 2009 was significantly lower than that of NBDE questions but increased in questions written from 2010 to 2018. The improvement of quality of MCQs had no impact on assessment performance of students.Conclusion: The enhanced cognitive levels of UCD MCQs written 2010-2018 coincides with the implementation of a faculty training program for writing high-ordered MCQs. In addition, this study shows that the use of Moore's expanded framework is on par with other known taxonomies in supporting educators in writing items and reviewing the process.Abbreviations: MCQs: Multiple Choice Questions; UCD: University Clinic of Dentistry; NBDE: National Board of Dental Examinations.

Spectral Characterization of Eight Marine Phytoplankton Phyla and Assessing a Pigment-Based Taxonomic Discriminant Analysis for the in Situ Classification of Phytoplankton Blooms.

Early stage identification of harmful algal blooms (HABs) has gained significance for marine monitoring systems over the years. Various approaches for in situ classification have been developed. Among them, pigment-based taxonomic classification is one promising technique for in situ characterization of bloom compositions, although it is yet underutilized in marine monitoring programs. To demonstrate the applicability and importance of this powerful approach for monitoring programs, we combined an ultra low-cost and miniaturized multichannel fluorometer with Fisher's linear discriminant analysis (LDA). This enables the real-time characterization of algal blooms at order level based on their spectral properties. The classification capability of the algorithm was examined with a leave-one-out cross validation of 53 different unialgal cultures conducted in terms of standard statistical measures and independent figures of merit. The separation capability of the linear discriminant analysis was further successfully examined in mixed algal suspensions. Besides this, the impact of the growing status on the classification capability was assessed. Further, we provide a comprehensive study of spectral features of eight different phytoplankton phyla including an extensive study of fluorescence excitation spectra and marker pigments analyzed via HPLC. The analyzed phytoplankton species belong to the phyla of Cyanobacteria, Dinophyta (Dinoflagellates), Bacillariophyta (Diatoms), Haptophyta, Chlorophyta, Ochrophyta, Cryptophyta, and Euglenophyta.

Time-resolved monitoring of heavy-metal intoxication in single hair by laser ablation ICP-DRCMS.

The potential of laser ablation inductively coupled plasma mass spectrometry for the time-resolved analysis of heavy-metal intoxication in human bodies by analysis of hair is demonstrated. As application, we analyzed forensic samples from one individual after Hg intake and from one treated with a Pt-containing cytostatic remedy. Single hairs were analyzed from the hair root to the tip by laser ablation ICP-MS with a spatial resolution of 20 mum (corresponding to approx. 2 h growth of the hair). Sulfur was used as internal standard and was analyzed by using oxygen as reaction gas in the dynamic reaction cell of the ICP-DRCMS. The detection limits for Hg and Pt were found to be 0.3 microg g(-1) and 0.5 ng g(-1), respectively. Standard uncertainties for the quantification results were 10% for Hg and approximately 15 % for Pt. The analyzed hair samples reflected the forensic evidence in both cases. A significant increase of Hg concentration, by a factor of 50, at the time of HgO administration could be shown, and variation of Pt in the hair strands could be used to monitor the time and relative amount of Pt intake by the patient. The investigations also revealed that the concentrations in the outer and the inner parts of the hair varied similarly with time, even though the concentration in the core of the hair is approximately 0.25 that at the surface for both Pt and Hg.