Selection in Reported Epidemiological Risks: An Empirical Assessment

BACKGROUND: Epidemiological studies may be subject to selective reporting, but empirical evidence thereof is limited. We empirically evaluated the extent of selection of significant results and large effect sizes in a large sample of recent articles. METHODS AND FINDINGS: We evaluated 389 articles of epidemiological studies that reported, in their respective abstracts, at least one relative risk for a continuous risk factor in contrasts based on median, tertile, quartile, or quintile categorizations. We examined the proportion and correlates of reporting statistically significant and nonsignificant results in the abstract and whether the magnitude of the relative risks presented (coined to be consistently ≥1.00) differs depending on the type of contrast used for the risk factor. In 342 articles (87.9%), ≥1 statistically significant relative risk was reported in the abstract, while only 169 articles (43.4%) reported ≥1 statistically nonsignificant relative risk in the abstract. Reporting of statistically significant results was more common with structured abstracts, and was less common in US-based studies and in cancer outcomes. Among 50 randomly selected articles in which the full text was examined, a median of nine (interquartile range 5–16) statistically significant and six (interquartile range 3–16) statistically nonsignificant relative risks were presented (p = 0.25). Paradoxically, the smallest presented relative risks were based on the contrasts of extreme quintiles; on average, the relative risk magnitude was 1.41-, 1.42-, and 1.36-fold larger in contrasts of extreme quartiles, extreme tertiles, and above-versus-below median values, respectively (p < 0.001). CONCLUSIONS: Published epidemiological investigations almost universally highlight significant associations between risk factors and outcomes. For continuous risk factors, investigators selectively present contrasts between more extreme groups, when relative risks are inherently lower

Linear beta pricing with inefficient benchmarks in a given factor structure

We show the equivalence between the zero-beta version of a multi-factor arbitrage pricing model and a linear pricing model utilizing undiversified inefficient benchmarks in a given factor structure. The resulting linear model is a two-beta model, with one beta related to the inefficient benchmark and another adjusting for its inefficiency. This linear model shows that there are only two distinctive and computable sources of risk, affecting security expected returns, despite the existence of several risk factors. In a short empirical example we demonstrate that the model can be employed to provide guidance and allow researchers to test for the validity of their selection of the underlying risk factors driving variations in security returns

Joint Compressed Sensing and Manipulation of Wireless Emissions with Intelligent Surfaces

Programmable, intelligent surfaces can manipulate electromagnetic waves impinging upon them, producing arbitrarily shaped reflection, refraction and diffraction, to the benefit of wireless users. Moreover, in their recent form of HyperSurfaces, they have acquired inter-networking capabilities, enabling the Internet of Material Properties with immense potential in wireless communications. However, as with any system with inputs and outputs, accurate sensing of the impinging wave attributes is imperative for programming HyperSurfaces to obtain a required response. Related solutions include field nano-sensors embedded within HyperSurfaces to perform minute measurements over the area of the HyperSurface, as well as external sensing systems. The present work proposes a sensing system that can operate without such additional hardware. The novel scheme programs the HyperSurface to perform compressed sensing of the impinging wave via simple one-antenna power measurements. The HyperSurface can jointly be programmed for both wave sensing and wave manipulation duties at the same time. Evaluation via simulations validates the concept and highlight its promising potential.Comment: Published at IEEE DCOSS 2019 / IoT4.0 workshop (https://www.dcoss.org/workshops.html). Funded by the European Union via the Horizon 2020: Future Emerging Topics - Research and Innovation Action call (FETOPEN-RIA), grant EU736876, project VISORSURF (http://www.visorsurf.eu

Accessory muscles around the superior radioulnar joint: a morphological study

During anatomical dissections on 36 human elbow joints, we observed the presence of three muscles around the superior radioulnar joint usually neglected by the classical anatomical literature, the lateral tensor muscle of the annular ligament (with an incidence of 16.6%), the medial tensor muscle of the annular ligament (11.1%) and the accessory supinator muscle (16.6%). We could not establish any association between the subject handedness and the sidedness of these aberrant muscles, neither we found a predominance in sidedness or in gender. Furthermore, we did not notice any significant predominance related to the occupation and specifically to heavy labor occupations. On the contrary we found these muscles to be more common in non-laborers, which supports the assumption that these variants constitute rather genetic than epigenetic traits. The knowledge of such anatomical variants facilitate the surgeon operating in the elbow region to better interpret supernumerary muscular bundles in the operative field

Diabetic Nephropathy: from bench to bedside

Diabetes mellitus together with arterial hypertension are the most common causes of chronic kidney disease (CKD). Notably, diabetic kidney disease (DKD) remains a major and independent risk for premature mortality. Therefore, continuous and accurate control of risk factors for the development of diabetic nephropathy is mandatory. Measurement of serum creatinine levels and calculation of estimated glomerular filtration rate (eGFR) according to CKD-EPI equation must be performed annually, Also, measurement of urine albumin and calculation of the urine albumin to creatine ratio rate (uACR) is recommended to be performed annually, too, as  uACR &gt; 30 mg/g creatinine is considered to be a continuous risk factor for cardiovascular disease. Equally important is good glycemic control, as determined by glycated hemoglobin levels of &lt; 7%, as well as control of hypertension, often with more than three anti-hypertensive drugs needed to achieve this goal. Inhibition of the renin-angiotensin-aldosterone system (RAAS) is not only effective in managing hypertension, but seems to reduce albuminuria levels among patients with diabetic nephropathy. However, combination of  angiotensin converting enzyme inhibitors  (ACE’s) with angiotensin receptor antagonists (AT2) or with direct renin inhibitors is not recommended due to the increased risk of hyperkalemia, hypotension and acute kidney injury.  Other antihypertensive drugs which decrease albuminuria levels are the newer dihydropyridines calcium blockers manidipine and the latest b-blockers (carvedilol). Dyslipidemia parameters should be improved, too, especially the serum LDL-cholesterol levels &lt;100 mg/dl. Vitamin D analogues have been shown to decrease albuminuria if eGFR &lt; 60 ml/min/1.73 cm2 on account of a) inhibition of RAAS b) immunomodulatory and anti-inflammatory effects and c) inhibition of interstitial fibrosis in conjunction with FGF-23 (Fibroblast Growth Factor-23). Besides, sodium glucose co-transporter 2 inhibitors, which produce glucosuria seem to possess nephroprotective properties among type 2 diabetic patients. In particular, the EMPAREG study has documented that empagliflozin reduces the relative risk of serum creatinine doubling by 44%, while the relative risk of introducing hemoperfusion has been decreased by 55% within four years. It seems likely that atrasentan, a selective antagonist of the receptor of endothelin A also reduces albuminuria by approximately 35%. Moreover, the significance of substances with anti-inflammatory properties, such as oxidase inhibitors, pentoxyfilline, and N-acetyl-cysteine remains to be elucidated. It is noteworthy that weight loss together with dietary consultation, not only are implicated in better glycemic control and dyslipidemia management, but also  in improving diabetic nephropathy per se