The Effects of Imperfect Top-Down Selection on the Accuracy of the Direct Range Restriction Adjustment

Accurate assessment of the effectiveness of personnel psychology functions is vital to the field. Many personnel decisions are made based on correlations between predictor variables and measures of job performance; however, those correlations are often affected by range restriction. As encountered in applied practice, range restriction weakens the strength of the correlation. Equations exist to correct for the effects of range restriction on correlations; these equations are widely accepted and used by Industrial-Organizational psychologists today. This study expands on research by Hall (2016), which examined the accuracy of the direct range restriction correction equation provided by Thorndike (1949) under varying degrees of the violation of the assumption of perfect top-down selection. A Monte Carlo analysis was conducted so that the adjusted sample correlations could be compared to known, unrestricted population correlations. The results of the study indicate that Thorndike’s correction equation provides adjusted sample correlations that were closer to the true population correlation when perfect top-down selection does not occur. Implications and recommendations for future research are discussed

Advances in the Treatment of Monoclonal Gammopaties: The Emerging Role of Targeted Therapy in Plasma Cell Dyscrasias

The paradigm for the treatment of monoclonal gammopaties has dramatically changed: therapeutic options in multiple myeloma (MM) have evolved from the introduction of melphalan and prednisone in the 1960s, high-dose chemotherapy and stem cell transplantation in the late 1980s and 1990s, to the rapid introduction of small novel molecules within the last seven years. Based on the understanding of the complex interaction of the MM cells with the bone marrow microenvironment and the signaling pathways that are dysregulated in this process, a number of novel therapeutic agents are now available. Specifically, three novel agents with a specific-targeted anti-MM activity, have been FDA-approved for the treatment of this disease, namely Bortezomib, thalidomide, and lenalidomide which are now all playing a key role in the treatment of MM. The success of targeted therapy in MM has since led to the development and investigation of more than 30 new compounds in this disease and in other plasma cell dyscrasias such as Waldenström’s macroglobulinemia and primary amyloidosis, both in the preclinical settings and as part of clinical trials

Low Back Pain: Current Surgical Approaches

Low back pain (LBP) is a worldwide phenomenon. The UK studies place LBP as the largest single cause of absence from work; up to 80% of the population will experience LBP at least once in their lifetime. Most individuals do not seek medical care and are not disabled by their pain once it is managed by nonoperative measures. However, around 10% of patients go on to develop chronic pain. This review outlines the basics of the traditional approach to spinal surgery for chronic LBP secondary to osteoarthritis of the lumbar spine as well as explains the novel concepts and terminology of back pain surgery. Traditionally, the stepwise approach to surgery starts with local anaesthetic and steroid injection followed by spinal fusion. Fusion aims to alleviate pain by preventing movement between affected spinal segments; this commonly involves open surgery, which requires large soft tissue dissection and there is a possibility of blood loss and prolonged recovery time. Established minimally invasive spine surgery techniques (MISS) aim to reduce all of these complications and they include laparoscopic anterior lumbar interbody fusion and MISS posterior instrumentation with pedicle screws and rods. Newer MISS techniques include extreme lateral interbody fusion and axial interbody fusion. The main problem of fusion is the disruption of the biomechanics of the rest of the spine; leading to adjacent level disease. Theoretically, this can be prevented by performing motion-preserving surgeries such as total disc replacement, facet arthroplasty, and non fusion stabilisation. We outline the basic concepts of the procedures mentioned above as well as explore some of the novel surgical therapies available for chronic LBP

Advances in the treatment of monoclonal gammopaties: The emerging role of targeted therapy in plasma cell dyscrasias

The paradigm for the treatment of monoclonal gammopaties has dramatically changed: therapeutic options in multiple myeloma (MM) have evolved from the introduction of melphalan and prednisone in the 1960s, high-dose chemotherapy and stem cell transplantation in the late 1980s and 1990s, to the rapid introduction of small novel molecules within the last seven years. Based on the understanding of the complex interaction of the MM cells with the bone marrow microenvironment and the signaling pathways that are dysregulated in this process, a number of novel therapeutic agents are now available. Specifically, three novel agents with a specific-targeted anti-MM activity, have been FDA-approved for the treatment of this disease, namely Bortezomib, thalidomide, and lenalidomide which are now all playing a key role in the treatment of MM. The success of targeted therapy in MM has since led to the development and investigation of more than 30 new compounds in this disease and in other plasma cell dyscrasias such as Waldenström’s macroglobulinemia and primary amyloidosis, both in the preclinical settings and as part of clinical trials

NACA Research Memorandums

Report presenting the results of a wind-tunnel investigation to determine the effects of a variation in wing taper ratio on the longitudinal characteristics of a wing-body combination at a variety of Mach numbers. The wings had an aspect ratio of 3, an unswept midchord line, and an NACA 64A003 profile. Results regarding the lift and pitching-moment characteristics and drag characteristics are provided