Screening for technical flaws in multiple-choice items. A generalizability study.

Construction errors in multiple-choice items are quite prevalent and constitute threats to test validity of multiple-choice tests. Currently very little research on the usefulness of systematic item screening by local review committees before test administration seem to exist. The aim of this study was therefore to examine validity and feasibility aspects of review committee screening for item flaws. We examined the reliability of item reviewers’ independent judgments of the presence/absence of item flaws with a generalizability study design and found only moderate reliability using five reviewers. Statistical analyses of actual exam scores could be a more efficient way of identifying flaws and improving average item discrimination of tests in local contexts. The question of validity of human judgments of item flaws is important - not just for sufficiently sound quality assurance procedures of tests in local test contexts - but also for the global research on item flaws

Screening for technical flaws in multiple-choice items. A generalizability study.

Construction errors in multiple-choice items are quite prevalent and constitute threats to test validity of multiple-choice tests. Currently very little research on the usefulness of systematic item screening by local review committees before test administration seem to exist. The aim of this study was therefore to examine validity and feasibility aspects of review committee screening for item flaws. We examined the reliability of item reviewers’ independent judgments of the presence/absence of item flaws with a generalizability study design and found only moderate reliability using five reviewers. Statistical analyses of actual exam scores could be a more efficient way of identifying flaws and improving average item discrimination of tests in local contexts. The question of validity of human judgments of item flaws is important - not just for sufficiently sound quality assurance procedures of tests in local test contexts - but also for the global research on item flaws

Schistosomiasis-induced squamous cell bladder carcinoma in an HIV-infected patient

SummaryThe burden of Schistosoma haematobium-associated bladder cancer is very high in Africa; nevertheless the disease can pose considerable diagnostic challenges in low prevalence countries. We present the case of a 40-year-old HIV co-infected woman, originally from Mozambique, who had persisting haematuria for more than a year. Investigations revealed invasive S. haematobium-associated squamous cell bladder cancer. If her origin had been taken into account, the diagnosis might have been made earlier. Awareness of the disease prevalence among HIV co-infected patients from endemic areas and timely screening of such patients is important for the early diagnosis of schistosomiasis and related complications, such as S. haematobium-associated squamous cell bladder cancer

Two cases of erythema induratum of Bazin – a rare cutaneous manifestation of tuberculosis

Tuberculosis remains a global disease burden, counting more than 9 million new cases per year. Tuberculosis is caused by infection with Mycobacterium tuberculosis-complex. Though most commonly affecting the lungs, any organ can become a site of tuberculous infection. Cutaneous tuberculosis is rare, representing 1-2% of all cases of tuberculosis. There are numerous different cutaneous manifestations of tuberculosis. We describe two cases of erythema induratum of Bazin, a so-called tuberculid manifestation of cutaneous TB. Both cases are patients from endemic areas. In the cases presented, there were no signs of other organs affected, and cutaneous lesions disappeared during anti-tuberculous treatment

A high-throughput cellulase screening system based on droplet microfluidics

A new ultra-high-throughput screening assay for the detection of cellulase activity was developed based on microfluidic sorting. Cellulase activity is detected using a series of coupled enzymes leading to the formation of a fluorescent product that can be detected on a chip. Using this method, we have achieved up to 300-fold enrichments of the active population of cells and greater than 90% purity after just one sorting round. In addition, we proved that we can sort the cellulase-expressing cells from mixtures containing less than 1% active cells