MRI-Determined Psoas Muscle Fat Infiltration Correlates with Severity of Weight Loss during Cancer Cachexia

Purpose: To evaluate the suitability of psoas and erector spinae muscle proton density fat fraction (PDFF) and fat volume as biomarkers for monitoring cachexia severity in an oncological cohort, and to evaluate regional variances in muscle parameters over time. Methods: In this prospective study, 58 oncological patients were examined by a 3 T MRI receiving between one and five scans. Muscle volume and PDFF were measured, segmentation masks were divided into proximal, middle and distal muscle section. Results: A regional variation of fat distribution in erector spinae muscle at baseline was found (p < 0.01). During follow-ups significant relative change of muscle parameters was observed. Relative maximum change of erector spinae muscle showed a significant regional variation. Correlation testing with age as a covariate revealed significant correlations for baseline psoas fat volume (r = −0.55, p < 0.01) and baseline psoas PDFF (r = −0.52, p = 0.02) with maximum BMI change during the course of the disease. Conclusion: In erector spinae muscles, a regional variation of fat distribution at baseline and relative maximum change of muscle parameters was observed. Our results indicate that psoas muscle PDFF and fat volume could serve as MRI-determined biomarkers for early risk stratification and disease monitoring regarding progression and severity of weight loss in cancer cachexia.

Influence of functional abilities on the quality of refereeing in handball

Background: Several factors contributed to the evolution of handball, and one of the most important changes for faster, more dynamic and aggressive game is the change of rules which increase physical demands of players and especially referees. The aim of this study is to determine whether functional abilities have an influence on the quality of refereeing. Material and methods: 31 subjects were involved in the research, all of them top-level referees with an average age of 34.66±6.44, height 184.02±5.87 cm and body mass 91.14±10.61 kg. Testing was divided into two parts: the first part was spiroergometric progressive test on a treadmill to diagnose functional abilities, and the second part was the official handball matches. Results: Results show an average relative maximum oxygen uptake of 45.35±6.12 ml/min/kg. No statistically significant correlation was found between better functional abilities of handball referees and a better quality of refereeing. Conclusions: Referees have a lower anaerobic capacity, which could lead to errors in their judgment during the highest physiological loads in a match. Referees are a homogeneous group due to elimination criteria on tests at official seminars. If there were no elimination criteria, there would be greater variability among referees, and it would be possible to confirm the hypothesis that better functional abilities would lead to a better quality of refereeing.

A Note on Simulation Pricing of π-Options

In this work, we adapt a Monte Carlo algorithm introduced by Broadie and Glasserman in 1997 to price a π-option. This method is based on the simulated price tree that comes from discretization and replication of possible trajectories of the underlying asset’s price. As a result, this algorithm produces the lower and the upper bounds that converge to the true price with the increasing depth of the tree. Under specific parametrization, this π-option is related to relative maximum drawdown and can be used in the real market environment to protect a portfolio against volatile and unexpected price drops. We also provide some numerical analysis.

A NEWLY DESIGNED ASSEMBLY LOCKING COMPRESSION PLATE TO TREAT COMMINUTED FRACTURES OF THE FEMORAL SHAFT: A BIOMECHANICAL STUDY

The aim of this paper is to compare the biomechanical characteristics of a newly designed assembly locking compression plate (NALCP) and traditional locking compression plate (LCP) for internal fixation of femoral-shaft comminuted fractures. A femoral-shaft wedge fracture model (AO classification 32-C2.1) was created in six pairs of femoral specimens ([Formula: see text]) randomly divided into two equal groups. Biomechanical properties were tested with axial and torsional loading tests. The relative maximum displacement of fracture blocks and strain was recorded. A strain diagram was made; the fatigue test results of NALCP specimens under axial load were recorded. Under axial load, the relative maximum displacement of fracture blocks in the [Formula: see text], [Formula: see text], and [Formula: see text] axes was smaller in NALCP specimens than in LCP specimens ([Formula: see text] and 0.01, respectively). Under torsional load, the relative maximum displacement of fracture blocks in the [Formula: see text] and [Formula: see text] axes in NALCP specimens was less than that in LCP specimens ([Formula: see text]) but no statistically significant difference in the [Formula: see text] axes ([Formula: see text]) was found. In both cases, the main NALCP strain was higher than the LCP strain ([Formula: see text]) but no statistically significant difference in mean strain ([Formula: see text]) was found. Our NALCP provides strong mechanical stability for comminuted femoral fractures and can effectively avoid stress concentration, reduce stress shielding, and facilitate bone healing.

Numerical and experimental investigation for the effect of permeability of spur dikes on local scour

The effect of using permeable spur dikes on the produced maximum scour depth compared to that of solid spur dikes is numerically investigated. The numerical model used for such purpose is the Nays-2DH model of the International River Interface Cooperative (iRIC) software package for bed and bank erosion. The model results are verified using the experimental data collected in this study by conducting experiments on five different models of spur dikes having different opening ratios. Using the statistical performance indices, the root mean square error and the coefficient of determination, the results showed an acceptable agreement between the numerical model results for the relative maximum scour depth defined by the ratio of the maximum scour depth to the flow depth and their corresponding observed values. A new empirical equation using nonlinear regression is developed using the experimental data collected in this study and tested with another existing empirical equation available in the literature for their accuracy in determining the relative maximum scour depth.

Optimal stopping rule for the full-information duration problem with random horizon

The full-information duration problem with a random number N of objects is considered. These objects appear sequentially and their values Xk are observed, where Xk, independent of N, are independent and identically distributed random variables from a known continuous distribution. The objective of the problem is to find a stopping rule that maximizes the duration of holding a relative maximum (e.g. the kth object is a relative maximum if Xk = max{X1, X2, . . ., Xk}). We assume that N is a random variable with a known upper bound n, so two models, Model 1 and Model 2, can be considered according to whether the planning horizon is N or n. The structure of the optimal rule, which depends on the prior distribution assumed on N, is examined. The monotone rule is defined and a necessary and sufficient condition for the optimal rule to be monotone is given for both models. Special attention is paid to the class of priors such that N / n converges, as n → ∞, to a random variable Vm having density fVm(v) = m(1 - v)m-1, 0 ≤ v ≤ 1 for a positive integer m. An interesting feature is that the optimal duration (relative to n) for Model 2 is just (m + 1) times as large as that for Model 1 asymptotically.