Beneficial and Deleterious Effects of Neutrophil Extracellular Traps on Infection

Polymorphonuclear neutrophils (PMNs) are the most abundant leukocytes in the blood and are considered as the first line of innate immune defence against infectious diseases. However, PMN cells have a crucial function in both innate and adaptive immune responses. Neutrophils have several mechanisms to control pathogens, and one of them is their capability to form neutrophil extracellular traps (NETs) that may control infection. NETs have the capacity to trap microorganisms, kill them, or avoid their dissemination. The aim of this chapter is to provide a comprehensive review on NETs, the cells that produce them, and some of the mechanisms involved in their formation, their role in the immune response, and the pros and cons of NETs, focusing mainly on infectious diseases

Concurrent and Construct Validity of Methods to Estimate Fat-Free Mass in Children, Adolescents, and Young Adults

INTRODUCTION: Indirect methodologies are available to estimate fat-free mass (FFM) as a skeletal muscle mass surrogate in field settings at low cost. However, there is a lack of knowledge related with the FMM estimations variability introduced by the available methods and its correlations with performance constructs. The association between repeated measures of FFM by different methodologies and strength tests must provide a valuable construct validity analysis, which allows us to select the best method to assess the functional body composition. PURPOSE: To analyze validity and agreement between laboratory and field methods to estimate FFM in children, adolescents, and young adults, and their relationships with strength. METHODS: We studied a dataset of participants aged 6-21y (531 assessments, 287 boys). FFM was evaluated by isotope dilution method (REF), dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA) and anthropometry (ANT). Isometric strength was assessed by limb dynamometry and dynamic strength as sprinting and jumping. Concurrent validity was analyzed by differences between methods and concordance correlation coefficient (CCC), agreement by Bland-Altman analysis, and construct validity by individual associations. RESULTS: FFM from ANT had the lowest bias in girls (-2.33±4.41kg, P≤0.0001) and from BIA in boys (-1.79±4.51kg, P≤0.0001). The best CCC was found for FFM-BIA (girls, 0.764; boys, 0.926). The highest correlation with constructs was found for handgrip and FFM-BIA in girls (r=-0.743) and FFM-REF in boys (r=0.812; both P≤0.001). CONCLUSION: Our results showed BIA was the best method to estimate FFM. Nonetheless, there was not a single method which correlated the best with all strength constructs. The low coordinative requirement of isometric strength test could be one of the reasons to find a better correlation with FFM than explosive dynamic tests, and this leads us to speculate that isometric strength is more dependent of body composition than dynamic tests. These findings needed to be refuted with additional constructs

Selfies beyond self-representation: the (theoretical) f(r)ictions of a practice

Drawing on a wide corpus of ethnographic research pro- jects, including on photography practices, young film- makers and writers, and current research with young unemployed people, we argue that contemporary under- standings of selfies either in relation to a ‘‘documenting of the self’’ or as a neoliberal (narcissistic) identity affirmation are inherently problematic. Instead, we argue that selfies should be understood as a wider social, cultural, and media phenomenon that understands the selfie as far more than a representational image. This, in turn, necessarily redirects us away from the object ‘‘itself,’’ and in so doing seeks to understand selfies as a socio-technical phenomenon that momentarily and tentatively holds together a number of different elements of mediated digital communication

Quantum mechanical description of Stern-Gerlach experiments

The motion of neutral particles with magnetic moments in an inhomogeneous magnetic field is described in a quantum mechanical framework. The validity of the semi-classical approximations which are generally used to describe these phenomena is discussed. Approximate expressions for the evolution operator are derived and compared to the exact calculations. Focusing and spin-flip phenomena are predicted. The reliability of Stern-Gerlach experiments to measure spin projections is assessed in this framework.Comment: 12 pages, 7 eps figures included, revtex, submitted to PR