Psychophysical or spinal reflex measures when assessing conditioned pain modulation?

Background: Assessing conditioning pain modulation (CPM) with spinal reflex measures may produce more objective and stable CPM effects than using psychophysical measures. The aim of the study was to compare the CPM effect and test–retest reliability between a psychophysical protocol with thermal test‐stimulus and a spinal reflex protocol with electrical test‐stimulus. Methods: Twenty‐five healthy volunteers participated in two identical experiments separated by minimum 1 week. The thermal test‐stimulus was a constant heat stimulation of 120 s on the subjects’ forearm with continuous ratings of pain intensity on a 10 cm visual analogue scale. The electrical test‐stimulus was repeated electrical stimulation on the arch of the foot for 120 s, which elicited a nociceptive withdrawal reflex recorded from the anterior tibial muscle. Conditioning stimulus was a 7°C water bath. Differences in the magnitude and test–retest reliability were investigated with repeated‐measures analysis of variance and by relative and absolute reliability indices. Results: The CPM effect was −46% and 4.5% during the thermal and electrical test‐stimulus (p < 0.001) respectively. Intraclass correlation coefficient of 0.5 and 0.4 was found with the electrical and thermal test‐stimulus respectively. Wide limits of agreement were found for both the electrical (−3.4 to 3.8 mA) and the thermal test‐stimulus (−3.2 to 3.6 cm). Conclusions: More pronounced CPM effect was demonstrated when using a psychophysical protocol with thermal test‐stimulus compared to a spinal reflex protocol with electrical test‐stimulus. Fair relative reliability and poor absolute reliability (due to high intraindividual variability) was found in both protocols. Significance: The large difference in CPM effect between the two protocols suggests that the CPM effect relates to pain perception rather than nociception on the spinal level. Due to poor absolute intrarater reliability, we recommend caution and further research before using any of the investigated CPM protocols in clinical decision making on an individual level

Use of Complex Lie Symmetries for Linearization of Systems of Differential Equations - II: Partial Differential Equations

The linearization of complex ordinary differential equations is studied by extending Lie's criteria for linearizability to complex functions of complex variables. It is shown that the linearization of complex ordinary differential equations implies the linearizability of systems of partial differential equations corresponding to those complex ordinary differential equations. The invertible complex transformations can be used to obtain invertible real transformations that map a system of nonlinear partial differential equations into a system of linear partial differential equation. Explicit invariant criteria are given that provide procedures for writing down the solutions of the linearized equations. A few non-trivial examples are mentioned.Comment: This paper along with its first part ODE-I were combined in a single research paper "Linearizability criteria for systems of two second-order differential equations by complex methods" which has been published in Nonlinear Dynamics. Due to citations of both parts I and II these are not replaced with the above published articl

Deciphering osteoarthritis genetics across 826,690 individuals from 9 populations

Osteoarthritis affects over 300 million people worldwide. Here, we conduct a genome-wide association study meta-analysis across 826,690 individuals (177,517 with osteoarthritis) and identify 100 independently associated risk variants across 11 osteoarthritis phenotypes, 52 of which have not been associated with the disease before. We report thumb and spine osteoarthritis risk variants and identify differences in genetic effects between weight-bearing and non-weight-bearing joints. We identify sex-specific and early age-at-onset osteoarthritis risk loci. We integrate functional genomics data from primary patient tissues (including articular cartilage, subchondral bone, and osteophytic cartilage) and identify high-confidence effector genes. We provide evidence for genetic correlation with phenotypes related to pain, the main disease symptom, and identify likely causal genes linked to neuronal processes. Our results provide insights into key molecular players in disease processes and highlight attractive drug targets to accelerate translation. © 2021 The Author

Search for squarks and gluinos in final states with one isolated lepton, jets, and missing transverse momentum at s = 13 TeV with the ATLAS detector

Abstract: The results of a search for gluino and squark pair production with the pairs decaying via the lightest charginos into a final state consisting of two W bosons, the lightest neutralinos (χ~10), and quarks, are presented: the signal is characterised by the presence of a single charged lepton (e± or μ±) from a W boson decay, jets, and missing transverse momentum. The analysis is performed using 139 fb-1 of proton–proton collision data taken at a centre-of-mass energy s=13 delivered by the Large Hadron Collider and recorded by the ATLAS experiment. No statistically significant excess of events above the Standard Model expectation is found. Limits are set on the direct production of squarks and gluinos in simplified models. Masses of gluino (squark) up to 2.2 (1.4 ) are excluded at 95% confidence level for a light χ~10