An explanatory mixed methods study on the validity and validation of students’ assessment results in the undergraduate surgery course

Abstract

Background/purpose: There is inadequate evidence of reported validity of the results of assessment instruments used to assess clinical competence. This study aimed at combining multiple lines of quantitative and qualitative evidence to support interpretation and use of assessment results.

Method: This study is a mixed methods explanatory research set in two stages of data collection and analysis (QUAN : qual). Guided by Messick’s conceptual model, quantitative evidences as reliability and correlation coefficients of various validity components were calculated using students’ scores, grades and success rates of the whole population of students in 2012/2013 and 2013/2014 (n=?383; 326). The underlying values that scaffold validity evidences were identified via Focus Group Discussions (FGD) with faculty and students; sampling technique was purposive; and results were analyzed by content analysis.

Results: (1) Themes that resulted from content analysis aligned with quantitative evidences. (2) Assessment results showed: (a) content validity (table of specifications and blueprinting in another study); (b) consequential validity (positive unintended consequences resulted from new assessment approach); (c) relationships to other variables [a statistically significant correlation among various assessment methods; with combined score (0.64–0.86) and between mid and final exam results (r?=?0.672)]; (d) internal consistency (high reliability of MCQ and OSCE: 0.81, 0.80); (3) success rates and grades distribution alone could not provide evidence to advocate an argument on validity of results.

Conclusion: The unified approach pursued in this study created a strong evidential basis for meaningful interpretation of assessment scores that could be applied in clinical assessments.     

Effect of self-etch adhesives on the internal adaptation of composite restoration: a CP-OCT Study

Odontology - Despite improvements in dental adhesive materials, internal adaptation remains a challenge in bonded restorations. The aim of this study was to compare microgaps and internal floor...     

Morphological and Quantitative Study of the Myenteric Plexus in the Human Tenia Coli

The longitudinal muscle in the large intestine in humans and some other mammalian species is concentrated in regions known as “tenia coli.” The myenteric plexus under the tenia is believed to be highly developed to control the adjacent large muscle mass, however, data on the innervation of this region are very scarce. We used whole mount preparations of human colon to characterize the organization of the myenteric plexus under the tenia coli (UT) and compared it with the plexus between the tenia (BT). Using histochemical staining for NADPH diaphorase, we found that the meshwork UT was 50% denser than BT, and that the ganglia UT were 30% wider. The density and size of the NADPH‐d positive neurons UT were similar to those of BT. We conclude that the myenteric plexus UT is considerably more developed than BT, and suggest to understand the control of colonic motility, the myenteric plexus UT needs to be further investigated. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.     

Gap junctions in dorsal root ganglia: Possible contribution to visceral pain

Peripheral injuries can lead to sensitization of neurons in dorsal root ganglia (DRGs), which can contribute to chronic pain. The neurons are sensitized by a combination of physiological and biochemical changes, whose full details are still obscure. Another cellular element in DRGs are satellite glial cells (SGCs), which surround the neurons, but little is known about their role in nociception. We investigated the contribution of SGCs to neuronal sensitization in isolated S1 DRGs from a mouse model of colonic inflammation induced by local application of dinitrosulfonate benzoate (DNBS). Retrograde labeling was used to identify DRG neurons projecting to the colon. Cell‐to‐cell coupling was determined by intracellular dye injection, and the electrical properties of the neurons were studied with intracellular electrodes. Pain behavior was assessed with von‐Frey hairs. The dye injections showed that 10–12 days after DNBS application there was a 6.6‐fold increase in gap junction–mediated coupling between SGCs surrounding adjacent neurons, and this occurred preferentially (another 2‐fold increase) near neurons that project to the colon. Neuron–neuron coupling incidence increased from 0.7% to 12.1% by colonic inflammation. Inflammation led to an augmented neuronal excitability, and to a reduced pain threshold. Gap junction blockers abolished the inflammation‐induced changes in SGCs and neurons, and significantly reversed the pain behavior. We propose that inflammation induces augmented cell coupling in DRGs that contributes to neuronal hyperexcitability, which in turn leads to visceral pain. Gap junction blockers may have potential as analgesic drugs.     

Necrosis Factor-α (TNF-α) and the Presence of Macrophage M2 and T Regulatory Cells in Nasopharyngeal Carcinoma

Objective:To investigate the correlation between TLR3 and pro-inflammatory cytokines (TNFα, IL6) expression with the distribution of macrophage M2 and Treg on Epstein Barr virus-encoded RNAs (EBER+) nasopharyngeal carcinoma (NPC) tissues. Methods:A total of 23 FFPE NPC tissue samples were obtained from patients in Dr. Sardjito General Hospital, Yogyakarta, Indonesia in 2008–2010, which expressed EBER was collected. The expressions of TLR3, TNFα, and IL6 were examined using immunofluorescence assay. The distribution of macrophage M2 and Treg were examined by immunohistochemistry with anti-CD163 and -FOXP3 antibodies, respectively. The quantification of fluorescence intensity was analyzed by the RGB space method using ImageJ software. The M2 interpretation was done by the eyeballing method and the M2 scores were divided into 0 (negative), 1 (scant), 2 (focal), 3 (abundant). The average number of Treg FOXP3+ cells in five high power fields was counted. The relationship between variables were tested by the Spearman correlation test, and the coefficient correlation was used to see the correlation between variables. Results:All EBER+ NPC specimens showed TLR3 expression intracellularly. The expression of TNFα could be observed in the cell membranes and secreted extracellularly, while IL6 was secreted to the extracellular area. The expression of TNFα was two times higher than IL6. Most specimens showed low M2 score (56.52%) and high Treg (52.17%). A positive correlation was found between TLR3 and IL6 (12.9%). TNFα was positively correlated with the M2 distribution of 13.7% and Treg distribution of 12.9%, while the rest were explained by other factors. Conclusion:TNFα has a positive correlation with M2 and Treg distribution,but mostly through a different mechanism other than EBER-TLR3 interaction. Possibly, other pro-inflammatory and anti-inflammatory cytokines are involved in the formation of the NPC microenvironment, especially related to the presence of M2 and Treg, which provide immunosuppressive effects in NPC tumors. Key Words: Epstein Barr virus, encoded RNAs, TLR3, pro-inflammatory cytokines, M2, Treg     

Transition metal oxide (NiO,CuO, ZnO)-doped calcium oxide catalysts derived from eggshells for the transesterification of refined waste cooking oil

This paper reports the synthesis of new transition metal oxide-modified CaO catalysts derived from eggshells for the transesterification of refined waste cooking oil. CaO is a well-known base catalyst for transesterification. However, its moderate basicity and low surface area have restricted its catalytic performance. Therefore, a new attempt was made to modify the CaO catalyst with transition metal oxides, including Ni, Cu and Zn oxides, via simple wetness impregnation method. The catalytic performance of the resulting modified CaO-based catalysts was evaluated through the transesterification reaction using refined waste cooking oil. The results showed that the NiO/CaO(10 : 90)(ES) catalyst calcined at 700 °C, demonstrated being highly potential as a catalyst. It gave the highest biodiesel production (97.3%) at the optimum conditions of 1 : 18 oil-to-methanol molar ratio, 6 wt% catalyst loading and 180 minutes reaction time as verified by response surface methodology (RSM). The high catalytic activity of NiO/CaO(10 : 90)(ES)(700 °C) was attributed to its high basicity (8.5867 mmol g⁻¹) and relatively large surface area (7.1 m² g⁻¹). The acid value and free fatty acids of the biodiesel produced under optimal process conditions followed the EN 14214 and ASTM D6751 limit with 0.17 mg KOH per g (AV) and 0.09 mg KOH per g (FFA), respectively.

This paper reports the synthesis of new transition metal oxide-modified CaO catalysts derived from eggshells for the transesterification of refined waste cooking oil.     

Synaptic activity of myenteric neurons in tissue culture

Intracellular recordings were made from myenteric neurons of the guinea-pig caecum grown in tissue culture. The experiments were carried out on cultures older than 15 days, in which the neurons formed ganglion-like aggregates with many interconnecting nerve fibres. Intracellular injection of horseradish peroxidase demonstrated that the neurons project processes both within and outside the aggregates. Spontaneous activity was recorded in about 50% of the cells. This activity was composed of depolarizing potentials 2-20 mV in amplitude, and in most cases 10-20 ms in duration. In some instances, the potentials occurred in short bursts. The spontaneous potentials appear to be nicotinic cholinergic excitatory postsynaptic potentials (EPSPs). Electrical stimulation of the connecting fibers elicited in the neurons nicotinic cholinergic EPSPs, since they were blocked by hexamethonium. By varying the stimulus intensity and by stimulating several fibers, it was shown that the neurons are multiple-innervated. During repetitive presynaptic stimulation at frequencies above 10 Hz, there was a progressive reduction of the EPSP amplitude. It is concluded that the cultured myenteric neurons retain many of the characteristics found in the freshly isolated preparation and may be useful for studying the synaptic properties of these cells.