USMLE Scores Do Not Predict the Clinical Performance of Emergency Medicine Residents

Background: Scores on “high-stakes” multiple choice exams such as the United States Medical Licensing Examination® (USMLE) are important screening and applicant ranking criteria used by residencies.Objective: We tested the hypothesis that USMLE scores do not predict overall clinical performance of emergency medicine (EM) residents.Methods: All graduates from our University-based EM residency between the years 2008 and 2015 were included. Residents who had incomplete USMLE records were terminated, transferred out of the program, or did not graduate within this timeframe were excluded from the analysis. Clinical performance was defined as a gestalt of the residency program’s leadership and was classified into three sets: top, average, and lowest clinical performer. Dissimilarities of the initial blind rankings were adjudicated during a consensus conference.Results: During the eight years of the study period, there were a total of 115 graduating residents: 73 men (63%) and 42 women. Nearly all of them (109; 95%) had allopathic medical degrees; the remainder had osteopathic degrees. There was not a statistically significant correlation between our ranking of clinical performance and the Step 2 Clinical Knowledge score. There was a non-significant correlation between clinical performance and the Step 1 score.Conclusion: Neither USMLE Step 1 nor Step 2 Clinical Knowledge were good predictors of the actual clinical performance of residents during their training. We feel that their scores are overemphasized in the resident selec­tion process

Orthogonal representations and connectivity of graphs

AbstractIt is proved that a graph on n nodes is k-connected if and only if its nodes can be represented by real vectors in dimension n – k such that (a) nonadjacent nodes are represented by orthogonal vectors and (b) any n – k of them are linearly independent. We show that the closure of the set of all representations with properties (a) and (b) is irreducible as an algebraic variety, and study the question of irreducibility of the variety of all representations with property (a)

An engineered Tetrahymena tRNA(Gln) for in vivo incorporation of unnatural amino acids into proteins by nonsense suppression

A new tRNA, THG73, has been designed and evaluated as a vehicle for incorporating unnatural amino acids site-specifically into proteins expressed in vivo using the stop codon suppression technique. The construct is a modification of tRNAGln(CUA) from Tetrahymena thermophila, which naturally recognizes the stop codon UAG. Using electrophysiological studies of mutations at several sites of the nicotinic acetylcholine receptor, it is established that THG73 represents a major improvement over previous nonsense suppressors both in terms of efficiency and fidelity of unnatural amino acid incorporation. Compared with a previous tRNA used for in vivo suppression, THG73 is as much as 100-fold less likely to be acylated by endogenous synthetases of the Xenopus oocyte. This effectively eliminates a major concern of the in vivo suppression methodology, the undesirable incorporation of natural amino acids at the suppression site. In addition, THG73 is 4-10-fold more efficient at incorporating unnatural amino acids in the oocyte system. Taken together, these two advances should greatly expand the range of applicability of the in vivo nonsense suppression methodology

Subacute Tension Hemopneumothorax with Novel Electrocardiogram Findings

This case report describes a patient with a subacute right-sided tension hemopneumothorax following an occult stab. The patient’s electrocardiogram (ECG), performed as part of a standardized triage process, demonstrated significant abnormalities that misguided initial resuscitation, but resolved following evacuation of the tension hemopneumothorax. Tension pneumothorax is typically regarded as an immediately life-threatening condition that requires emergent management with needle or tube thoracostomy. However, we believe that subacute tension pneumothorax may be a rarely observed clinical phenomenon and may lead to unique ECG findings. We believe that the ECG changes we observed provided an early clue to the eventual diagnosis of a subacute tension pneumothorax and have not been previously described in this setting.

Histological Chages of Testis and Caput Epididymis in the Goat after Cannulation of the Rete Testis

雄ヤギ5頭を用い, 精巣網カテーテル装着手術後の精巣および精巣上体頭の組織構造を観察するとともに精巣静脈血中のテストステロン濃度を調べた。カテーテル装着手術後の精巣は, いずれも萎縮し, 正常な精子形成過程が観察される精細管は少なかった。また, ライディヒ細胞の形態や染色性には異常は認められなかった。一方, 精巣上体頭では, 精巣上体管が萎縮し, 主細胞の高さは無傷のものよりも有意に減少した。同様の組織構造の変化は, 精巣輸出管を切除した場合の精巣および精巣上体頭でも認められた。精巣静脈血中のテストステロン濃度は無傷の場合94.4ng/mlであり, カテーテル装着手術後では86.5∿342.8ng/mlであった。 / The testis and caput epididymis of the goat after cannulation of the rete testis or efferentiectomy were examined histologically. The concentration of testosterone in testicular venous blood collected from the same animals was also measured by radioimmunoassay. After cannulation, seminiferous tubules showed a sign of degeneration, although no morphological change of Leydig cells was observed. Epididymal ducts were severely atrophied and the height of principal epithelial cells was significantly decreased. A similar damage was observed in the testis and epididymis after efferentiectomy. When the efferent duct bundle had been incompletely ligated at cannulation, or rete testis catheter was kept in place until sampling time, damages in the testis were less severe. And in the former case the epididymis was impaired less severely. The concentration of testosterone in testicular venous blood collected from an intact animal was 94.4ng/ml, while that obtained after cannulation was 86.5-342.8ng/ml. These results suggest that degeneration of germ cells in seminiferous tubules observed after cannulation of the rete testis or efferentiectomy may be caused by stagnation of rete testicular fluid in the tubules, and that testosterone in the fluid plays important roles in the maintenance of morphology and function of the principal cells in the caput epididymis

Pseudorandomness for Regular Branching Programs via Fourier Analysis

We present an explicit pseudorandom generator for oblivious, read-once, permutation branching programs of constant width that can read their input bits in any order. The seed length is $O(\log^2 n)$, where $n$ is the length of the branching program. The previous best seed length known for this model was $n^{1/2+o(1)}$, which follows as a special case of a generator due to Impagliazzo, Meka, and Zuckerman (FOCS 2012) (which gives a seed length of $s^{1/2+o(1)}$ for arbitrary branching programs of size $s$). Our techniques also give seed length $n^{1/2+o(1)}$ for general oblivious, read-once branching programs of width $2^{n^{o(1)}}$, which is incomparable to the results of Impagliazzo et al.Our pseudorandom generator is similar to the one used by Gopalan et al. (FOCS 2012) for read-once CNFs, but the analysis is quite different; ours is based on Fourier analysis of branching programs. In particular, we show that an oblivious, read-once, regular branching program of width $w$ has Fourier mass at most $(2w^2)^k$ at level $k$, independent of the length of the program.Comment: RANDOM 201

Employee engagement, human resource management practices and competitive advantage

AbstractPurpose - The purpose of this paper is to argue in support of a model that shows how four key HRM practices focused on engagement influence organizational climate, job demands and job resources, the psychological experiences of safety, meaningfulness and availability at work, employee engagement, and individual, group and organizational performance and competitive advantage.Design/methodology/approach - This conceptual review focuses on the research evidence showing interrelationships between organizational context factors, job factors, individual employee psychological and motivational factors, employee outcomes, organizational outcomes and competitive advantage. The proposed model integrates frameworks that have previously run independently in the HR and engagement literatures.Findings - The authors conclude that HRM practitioners need to move beyond the routine administration of annual engagement surveys and need to embed engagement in HRM policies and practices such personnel selection, socialization, performance management, and training and development.Practical implications - The authors offer organizations clear guidelines for how HR practices (i.e. selection, socialization, performance management, training) can be used to facilitate and improve employee engagement and result in positive outcomes that will help organizations achieve a competitive advantage.Originality/value - The authors provide useful new insights for researchers and management professionals wishing to embed engagement within the fabric of HRM policies and practices and employee behaviour, and organizational outcomes.<br /