Validity of very short answer versus single best answer questions for undergraduate assessment

Background Single Best Answer (SBA) questions are widely used in undergraduate and postgraduate medical examinations. Selection of the correct answer in SBA questions may be subject to cueing and therefore might not test the student’s knowledge. In contrast to this artificial construct, doctors are ultimately required to perform in a real-life setting that does not offer a list of choices. This professional competence can be tested using Short Answer Questions (SAQs), where the student writes the correct answer without prompting from the question. However, SAQs cannot easily be machine marked and are therefore not feasible as an instrument for testing a representative sample of the curriculum for a large number of candidates. We hypothesised that a novel assessment instrument consisting of very short answer (VSA) questions is a superior test of knowledge than assessment by SBA. Methods We conducted a prospective pilot study on one cohort of 266 medical students sitting a formative examination. All students were assessed by both a novel assessment instrument consisting of VSAs and by SBA questions. Both instruments tested the same knowledge base. Using the filter function of Microsoft Excel, the range of answers provided for each VSA question was reviewed and correct answers accepted in less than two minutes. Examination results were compared between the two methods of assessment. Results Students scored more highly in all fifteen SBA questions than in the VSA question format, despite both examinations requiring the same knowledge base. Conclusions Valid assessment of undergraduate and postgraduate knowledge can be improved by the use of VSA questions. Such an approach will test nascent physician ability rather than ability to pass exams

An unusual cause of gynaecomastia in a male

Summary: Beta-human chorionic gonadotropin (βhCG) is normally produced by syncytiotrophoblasts of the placenta during pregnancy and aids embryo implantation. However, it is also secreted in varying amounts in non-pregnant conditions commonly heralding a neoplastic process. We present a case of 50-year-old man, who presented with bilateral gynaecomastia with elevated testosterone, oestradiol, suppressed gonadotropins with progressively increasing levels of human chorionic gonadotropin (hCG). Biochemical and radiological investigations including ultrasonography of testes, breast tissue, MRI pituitary and CT scan full body did not identify the source of hCG. FDG PET scan revealed a large mediastinal mass with lung metastasis. Immunostaining and histological analysis confirmed the diagnosis of primary choriocarcinoma of the mediastinum. It is highly aggressive and malignant tumor with poor prognosis. Early diagnosis and management are essential for the best outcome. Learning Points: High βhCG in a male patient or a non-pregnant female suggests a paraneoplastic syndrome. In the case of persistently positive serum hCG, exclude immunoassay interference by doing the urine hCG as heterophilic antibodies are not present in the urine. Non-gestational choriocarcinoma is an extremely rare trophoblastic tumor and should be considered in young men presenting with gynaecomastia and high concentration of hCG with normal gonads. A high index of suspicion and extensive investigations are required to establish an early diagnosis of extra-gonadal choriocarcinoma. Early diagnosis is crucial to formulate optimal management strategy and to minimize widespread metastasis for best clinical outcome

Use of capecitabine in management of early colon cancer

Capecitabine (Xeloda®, Roche, Basel, Switzerland) is a pro-drug of 5-fluorouracil (5-FU), and it is converted to 5-FU in the cancer cell by enzymatic degradation. The role of capecitabine in colorectal cancer has evolved in the last 15 years. In early trials in the metastatic setting, capecitabine has shown superior response rates compared with those achieved with 5-FU (Mayo Clinic regimen) (26% vs 17%), with equivalent progression-free survival and overall survival. In the adjuvant setting, the Xeloda in Adjuvant Colon Cancer Therapy (X-ACT) trial demonstrated that capecitabine as a single agent led to improvement in relapse-free survival (hazard ratio: 0.86, 95% confidence interval: 0.74–0.99, P = 0.04) and was associated with significantly fewer adverse events than 5-FU plus leucovorin (LV, folinic acid). On the basis of the X-ACT trial, capecitabine was approved by the United States Food and Drug Administration, the National Institute for Clinical Excellence, and the Scottish Medicines Consortium as monotherapy for the adjuvant treatment of stage III colon cancer. The next step was to incorporate capecitabine into combination therapy. The XELOXA trial studied the combination of capecitabine and oxaliplatin (XELOX) vs 5-FU/LV and demonstrated 5-year disease-free survival of 66% for XELOX, compared with 60% for 5-FU/LV. The toxicity profile was also quite comparable in the two arms. So both the single agent use of capecitabine as well as in combination with oxaliplatin can be considered as part of the standard of care in management of early colon cancer in appropriately selected patient groups

A Scientist's Guide to Achieving Broader Impacts through K-12 STEM Collaboration.

The National Science Foundation and other funding agencies are increasingly requiring broader impacts in grant applications to encourage US scientists to contribute to science education and society. Concurrently, national science education standards are using more inquiry-based learning (IBL) to increase students' capacity for abstract, conceptual thinking applicable to real-world problems. Scientists are particularly well suited to engage in broader impacts via science inquiry outreach, because scientific research is inherently an inquiry-based process. We provide a practical guide to help scientists overcome obstacles that inhibit their engagement in K-12 IBL outreach and to attain the accrued benefits. Strategies to overcome these challenges include scaling outreach projects to the time available, building collaborations in which scientists' research overlaps with curriculum, employing backward planning to target specific learning objectives, encouraging scientists to share their passion, as well as their expertise with students, and transforming institutional incentives to support scientists engaging in educational outreach

On the dynamic tensile strength of Zirconium

Despite its fundamental nature, the process of dynamic tensile failure (spall) is poorly understood. Spall initiation via cracks, voids, etc, before subsequent coalesce, is known to be highly microstructure-dependant. In particular, the availability of slip planes and other methods of plastic deformation controls the onset (or lack thereof) of spall. While studies have been undertaken into the spall response of BCC and FCC materials, less attention has paid to the spall response of highly anisotropic HCP materials. Here the dynamic behaviour of zirconium is investigated via plate-impact experiments, with the aim of building on an ongoing in-house body of work investigating these highly complex materials. In particular, in this paper the effect of impact stress on spall in a commercially sourced Zr rod is considered, with apparent strain-rate softening highlighted

Apply Parametric Shared Frailty Models to Colorectal Cancer Patients

 Colorectal cancer is a combination of colon and rectal cancer that indicates an abnormal growth of cells in either the colon or rectum and is named according to its original location. After treatment, cancer may return to the primary site of the original tumor or to a different location in the body once or more, which is called recurrent. This paper aimed to model this type of data from 128 colorectal cancer patients collected at Hiwa hospital in Sulaimani considering the gamma shared and inverse Gaussian shared frailty models for analyzing the patient’s survival times with colorectal cancer recurrence and estimate the prognostic factor’s impact on their survival. Comparison of the results of these models with those without a frailty model using Weibull, log-logistic, and lognormal as a baseline distribution. To identify the best model for the data the (AIC) Akaike Information Criterion and (BIC) Bayesian Information Criterion were also used. Results showed that the cancer stage was the only significant factor affecting survival in recurrent events, as well as evidence of existing heterogeneity in colorectal patients. According to (AIC) and (BIC), the Weibull as baseline distribution with shared Gamma frailty model proved the most efficient model for the colorectal recurrent data. In Conclusion, the shared frailty model is better than no frailty when analyzing this type of data

Pituitary Apoplexy: Report Of Two Cases

Pituitary apoplexy is a common clinical syndrome characterised by acute headache, ophthalmoplegia, diminished visual acuity and altered mental status caused by the sudden haemorrhage or infarction of the pituitary gland. The two cases reported highlight the variability in presentation which underscores the need for a high index of suspicion and the need for MRI in patients presenting with a thunderclap headache and \'normal\' initial investigations. East African Medical Journal Vol. 85 (3) 2008: pp. 142-14

The variance on the shock response of a carbon fibre composite due to the orientation of the weave

Three different orientations of a tape-wrapped carbon fibre composite with phenolic resin matrix (abbreviated to TWCP) have been investigated under one-dimensional shock loading. This has been achieved via a single-stage gas gun, with manganin gauges as the diagnostic tool. The orientations of TWCP studied in this paper were 25°, 45° and 90°, with respect to the impact face. The shock response of these orientations, for this material, has been obtained (the Hugoniot equation of state). These results have been contrasted with previously reported literature data for the same material at different orientations (0° and 20°). It was found that orientation had minimal effect on the behaviour of this composite under shock. The exception to this was the 90° orientation which exhibited an elastic precursor at particle velocities of less than 0.65 mm µs−1; where the shock velocity was equivalent to the elastic sound speed of the material

Enhancement of voip and video streaming performance over IEEE802.11e WLAN

There are various versions of IEEE802.11 WLAN in the market, and each applies different modulation technique and operates in different frequency bands. For example, the IEEE 802.11 b version provides data rates up to 11 Mb/s on the wireless medium, applying complementary code keying (CCK) and direct sequence spread spectrum (DSSS) as modulation technique. It operates in the industrial, scientific, and medical (ISM) band at 2.4 GHz. On the other hand, the IEEE 802.11 a version operates in the unlicensed 5 GHz band, and provides data rates up to 54 Mb/s on the wireless medium, applying the multicarrier technique orthogonal frequency-divi sion multiplexing (OFDM) as the modulation technique [1]. The 802.11 g version applies the same multicarrier modulation technique as 802.11 a, but operates in the 2.4 GHz ISM band like 802.11 b. However, due to channel conditions and protocol overhead, the maximum achievable throughput on the MAC layer is less than the data rate available on the wireless medium for the mentioned IEEE 802.11 version

Pancreas Retrieval for Whole Organ and Islet Cell Transplantation

For more than five decades, we have been refining advances in pancreas whole organ and islet cell transplantation as clinical therapies to treat the ever-increasing number of patients suffering from type-1-diabetes. Research and clinical practice have contributed to making both whole organ and cellular transplantation viable therapeutic options for a broader range of patients. Furthermore, both forms of clinical transplantation results have progressively improved, due to the ongoing refinement of organ donation and its various technical processes, combined with the evolution of immunosuppression and patient care now offering excellent long-term treatment for both type-1-diabetes and concomitant renal failure. This chapter provides an overview on how this has been undertaken and achieved over decades to ultimately provide outstanding outcomes on par with other organ transplantation results. Briefly, we cover the history of pancreas retrieval procedures, the importance of donor selection, the intricate processes of the organ donor operation, preservation of the pancreas, and the ideal ways to best improve outcomes for transplantation. Improving and providing the optimal donor and preservation conditions underpinning the success of subsequent whole pancreas or islet transplantation as a safe, effective, and feasible therapeutic option for an increasing number of patients suffering from type-1-diabetes