9 research outputs found
Modified autonomic balance in offsprings of diabetics detected by spectral analysis of heart rate variability
This study was performed to evaluate the influence of family history for non–insulin-dependent diabetes mellitus (NIDDM) on autonomic balance. The latter was assessed by spectral analysis of heart rate variability (SA-HRV) and by analyzing the relative contribution of low-frequency (LF) and high-frequency (HF) components. Twenty glucose normotolerant offsprings of NIDDM parents and 20 controls underwent a 1-hour continuous electrocardiogram (ECG). LF and HF (mean 6 SEM in normalized units [NU]), respectively increased and decreased in offspring versus controls. The LF/HF ratio (mean 6 SEM) significantly increased (LF/HF 5 3.25 6 0.7 v 1.45 6 0.5, P < .0001 offsprings v controls). To test a stimulated response, a passive tilting (1 90°) after 30 minutes of bed rest (0°) was performed in a subsample of subjects (10 offsprings v 10 controls). During bed rest, we found significantly higher values of the LF/HF ratio in offsprings versus controls (1.93 6 0.3 v 1.08 6 0.2, P < .05), whereas in the head-up position, the LF/HF ratio value increased to the same levels in the 2 groups (6.48 6 1.3 v 6.89 6 1.4, not significant [NS]). NIDDM family history is characterized in the basal condition by an imbalance of the autonomic system, which, compared with controls, is expressed by a higher weight of sympathetic and a lower weight of parasympathetic components. No significant differences can be found under stimulated conditions
Microgravity and the intervertebral disc: The impact of space conditions on the biomechanics of the spine
The environmental conditions to which astronauts and other military pilots are subjected represent a unique example for understanding and studying the biomechanical events that regulate the functioning of the human body. In particular, microgravity has shown a significant impact on various biological systems, such as the cardiovascular system, immune system, endocrine system, and, last but not least, musculoskeletal system. Among the potential risks of flying, low back pain (LBP) has a high incidence among astronauts and military pilots, and it is often associated with intervertebral disc degeneration events. The mechanisms of degeneration determine the loss of structural and functional integrity and are accompanied by the aberrant production of pro-inflammatory mediators that exacerbate the degenerative environment, contributing to the onset of pain. In the present work, the mechanisms of disc degeneration, the conditions of microgravity, and their association have been discussed in order to identify possible molecular mechanisms underlying disc degeneration and the related clinical manifestations in order to develop a model of prevention to maintain health and performance of air- and space-travelers. The focus on microgravity also allows the development of new proofs of concept with potential therapeutic implications
Trauma and the Politics of Memory of the Uruguayan Dictatorship
Ethnographic research on the life experiences of former political prisoners and their families in Uruguay suggests the need for rethinking of the concept of trauma, which is often inadequate to convey the historical and social specificity of painful memories. The collective wound is constructed in public space, and intimate memories are closely linked to the framework in which they are embedded. Working on the victim's self is not sufficient to overcome the trauma, distracting attention from the need for social recognition and justice. Making history and doing justice are unavoidable steps in the establishment of a different political regime.Las investigaciones etnográficas sobre las experiencias de vida de ex presos políticos y sus familias en Uruguay sugieren la necesidad de replantearse el concepto de trauma, el cual suele ser casi siempre inadecuado para expresar la especificidad histórica y social de las memorias dolorosas. La herida colectiva se construye en el espacio público y las memorias íntimas están estrechamente vinculadas con el marco en el que están inmersas. Trabajar sólo con el yo de la víctima no es suficiente para superar el trauma, y desvía la atención de la necesidad de reconocimiento social y justicia. Hacer historia y hacer justicia son pasos ineludibles en el establecimiento de un régimen político diferente
Divertor Tokamak Test facility project: status of design and implementation
An overview is presented of the progress since 2021 in the construction and scientific programme preparation of the Divertor Tokamak Test (DTT) facility. Licensing for building construction has been granted at the end of 2021. Licensing for Cat. A radiologic source has been also granted in 2022. The construction of the toroidal field magnet system is progressing. The prototype of the 170 GHz gyrotron has been produced and it is now under test on the FALCON facility. The design of the vacuum vessel, the poloidal field coils and the civil infrastructures has been completed. The shape of the first DTT divertor has been agreed with EUROfusion to test different plasma and exhaust scenarios: single null, double null, X-divertor and negative triangularity plasmas. A detailed research plan is being elaborated with the involvement of the EUROfusion laboratories
Recent progress in L-H transition studies at JET: Tritium, Helium, Hydrogen and Deuterium
We present an overview of results from a series of L-II transition experiments undertaken at JET since the installation of the ITER-like-wall (JET-ILW), with beryllium wall tiles and a tungsten divertor. Tritium, helium and deuterium plasmas have been investigated. Initial results in tritium show ohmic L-H transitions at low density and the power threshold for the L-H transition (P-LH) is lower in tritium plasmas than in deuterium ones at low densities, while we still lack contrasted data to provide a scaling at high densities. In helium plasmas there is a notable shift of the density at which the power threshold is minimum ((n) over bar (e,min)) to higher values relative to deuterium and hydrogen references. Above (n) over bar (e,min) (He) the L-H power threshold at high densities is similar for D and He plasmas. Transport modelling in slab geometry shows that in helium neoclassical transport competes with interchange-driven transport, unlike in hydrogen isotopes. Measurements of the radial electric field in deuterium plasmas show that E-r shear is not a good indicator of proximity to the L-H transition. Transport analysis of ion heat flux in deuterium plasmas show a non-linearity as density is decreased below (n) over bar (e,min). Lastly, a regression of the JET-ILW deuterium data is compared to the 2008 ITPA scaling law
Analysis of ELM stability with extended MHD models in JET, JT-60U and future JT-60SA tokamak plasmas
The stability with respect to a peelingballooning mode (PBM) was investigated numerically with extended MHD simulation codes in JET, JT-60U and future JT-60SA plasmas. The MINERVA-DI code was used to analyze the linear stability, including the effects of rotation and ion diamagnetic drift (w∗i), in JET-ILW and JT-60SA plasmas, and the JOREK code was used to simulate nonlinear dynamics with rotation, viscosity and resistivity in JT-60U plasmas. It was validated quantitatively that the ELM trigger condition in JET-ILW plasmas can be reasonably explained by taking into account both the rotation and w∗i effects in the numerical analysis. When deuterium poloidal rotation is evaluated based on neoclassical theory, an increase in the effective charge of plasma destabilizes the PBM because of an acceleration of rotation and a decrease in w∗i. The difference in the amount of ELM energy loss in JT-60U plasmas rotating in opposite directions was reproduced qualitatively with JOREK. By comparing the ELM affected areas with linear eigenfunctions, it was confirmed that the difference in the linear stability property, due not to the rotation direction but to the plasma density profile, is thought to be responsible for changing the ELM energy loss just after the ELM crash. A predictive study to determine the pedestal profiles in JT-60SA was performed by updating the EPED1 model to include the rotation and w∗i effects in the PBM stability analysis. It was shown that the plasma rotation predicted with the neoclassical toroidal viscosity degrades the pedestal performance by about 10% by destabilizing the PBM, but the pressure pedestal height will be high enough to achieve the target parameters required for the ITER-like shape inductive scenario in JT-60SA