Embodied neurology: an integrative framework for neurological disorders

From a systems biology perspective, the brain and spinal cord are interwoven with the body, through afferent and efferent synaptic connections—they are literally ‘embodied’ (Adams et al., 2013). Neurologists appreciate the embodied nature of neurological disorders in terms of diagnosis, classification and their understanding of the underlying pathophysiology. They routinely use a combination of physical examinations (e.g. scales that test motor, sensory and autonomic function) in conjunction with physiological, biochemical and anatomical measures (e.g. electrophysiology, serum and CSF, and radiology) of the peripheral and central nervous system. These measures often produce combinations of symptoms and signs that translate into conventional nosological classifications. While therapeutics focus on the ‘treatable’ cause of a disorder, it is difficult to separate out the impact on the patient due to the primary effects of a lesion/insult etc. and the effects of (possibly delayed) secondary processes that may be reasonable targets for interventions on their own. Moreover, standard neurological assessments often fail to distinguish between pathogenic and compensatory processes. This state of affairs calls for a better understanding of neurological disease within a formal framework that links pathology to phenomenology (i.e. symptoms, impairment and physical signs). We suggest that such a framework should pay special attention to the embodied nature of the nervous system and the implicit pathophysiological and compensatory processes that can be present throughout the neuroaxis. In particular, we postulate that reciprocal information flows, between the body and the nervous system, are crucial for understanding and treating neurological disorders. This framework aims to link pathology to phenomenology, while respecting the ‘embodied’ nature of the nervous system. If fully realized, the framework of embodied neurology has the potential to improve functional outcome following individualized treatment (i.e. precision neurology), promote successful translation of novel therapeutics into clinical use, and refine nosology in the context of disease heterogeneity.Our description of embodied neurology is largely theoretical and is based on a series of focused workshops. It draws on recent advances in biophysical modelling of functional (Deco et al., 2008) and microstructural processes and neuroimaging (Weiskopf et al., 2015). These advances—together with preclinical research—constitute the three tenets of embodied neurology: biophysical modelling, quantitative physiological measures (with an emphasis on non-invasive neuroimaging) and preclinical research on basic mechanisms. These three have a particular focus on the entire nervous system

Seagrass can mitigate negative ocean acidification effects on calcifying algae

The ultimate effect that ocean acidification (OA) and warming will have on the physiology of calcifying algae is still largely uncertain. Responses depend on the complex interactions between seawater chemistry, global/local stressors and species-specific physiologies. There is a significant gap regarding the effect that metabolic interactions between coexisting species may have on local seawater chemistry and the concurrent effect of OA. Here, we manipulated CO2 and temperature to evaluate the physiological responses of two common photoautotrophs from shallow tropical marine coastal ecosystems in Brazil: the calcifying alga Halimeda cuneata, and the seagrass Halodule wrightii. We tested whether or not seagrass presence can influence the calcification rate of a widespread and abundant species of Halimeda under OA and warming. Our results demonstrate that under elevated CO2, the high photosynthetic rates of H. wrightii contribute to raise H. cuneata calcification more than two-fold and thus we suggest that H. cuneata populations coexisting with H. wrightii may have a higher resilience to OA conditions. This conclusion supports the more general hypothesis that, in coastal and shallow reef environments, the metabolic interactions between calcifying and non-calcifying organisms are instrumental in providing refuge against OA effects and increasing the resilience of the more OA-susceptible species.E.B. would like to thank the Coordenação de Aperfeiçoamento de Pessoas de Nível Superior (CAPES) for Masters funding. Funding for this project came from the Synergism grant (CNPq 407365/2013-3). We extend our thanks to the Brazil-based Projeto Coral Vivo and its sponsor PetroBras Ambiental for providing the Marine Mesocosm structure and experimental assistance.info:eu-repo/semantics/publishedVersio

Silicon carbide particulates incorporated into microalloyed steel surface using TIG: microstructure and properties

Surface metal matrix composites have been developed to enhance properties such as erosion, wear and corrosion of alloys. In this study, ~5 µm or ~75 µm SiC particulates were preplaced on a microalloyed steel. Single track surface zones were melted by a tungsten inert gas torch, and the effect of two heat inputs, 420Jmm-1 and 840 Jmm-1,compared. The results showed that the samples melted using 420Jmm-1 were crack-free. Pin-on-disk wear testing under dry sliding conditions were conducted. The effects of load and sliding velocity were used to characterise the performance of the crack-free samples. Microstructural and X-ray diffraction studies of the surface showed that the SiC had dissolved, and that martensite, was the main phase influencing the hardness

Computations of uncertainty mediate acute stress responses in humans

The effects of stress are frequently studied, yet its proximal causes remain unclear. Here we demonstrate that subjective estimates of uncertainty predict the dynamics of subjective and physiological stress responses. Subjects learned a probabilistic mapping between visual stimuli and electric shocks. Salivary cortisol confirmed that our stressor elicited changes in endocrine activity. Using a hierarchical Bayesian learning model, we quantified the relationship between the different forms of subjective task uncertainty and acute stress responses. Subjective stress, pupil diameter and skin conductance all tracked the evolution of irreducible uncertainty. We observed a coupling between emotional and somatic state, with subjective and physiological tuning to uncertainty tightly correlated. Furthermore, the uncertainty tuning of subjective and physiological stress predicted individual task performance, consistent with an adaptive role for stress in learning under uncertain threat. Our finding that stress responses are tuned to environmental uncertainty provides new insight into their generation and likely adaptive function. Copyright The Authors

The relationship between stimulus intensity and response amplitude for the photopic negative response of the flash electroretinogram

The aim of this study was to investigate the relationship between stimulus intensity and response amplitude for the photopic negative response (PhNR) of the flash ERG. Specific aims were (i) to determine whether a generalized Naka-Rushton function provided a good fit to the intensity-response data and (ii) to determine the variability of the parameters of the best-fitting Naka-Rushton models. Electroretinograms were recorded in 18 participants, on two occasions, using both DTL fibre and skin active electrodes, in response to Ganzfeld red stimuli (Lee filter "terry red") ranging in stimulus strength from -1.30 to 0.53 log cd.s.m(-2) (0.28-2.11 log phot td.s) presented over a steady blue background (Schott glass filter BG28; 3.9 log scot td). PhNR amplitude was measured from b-wave peak and from pre-stimulus baseline. The Naka-Rushton function was fitted to all intensity-response data, and parameters, 'n', 'Vmax' and 'K' were obtained. Coefficients of variation (CoV), and inter-ocular and inter-session limits of agreement (LoA) were calculated for both Naka-Rushton parameters. A generalized Naka-Rushton function was found to provide a good fit to the intensity-response data, except at the highest stimulus intensity, where a reduction in amplitude occurred in many individuals. The 'Vmax' parameter was less variable than 'K' for all intensity-response data. Variability was lower for DTL than skin electrodes, and for peak-to-trough PhNR measurements, compared to baseline-to-trough. This study has demonstrated for the first time that the Naka-Rushton model provides a useful means of quantifying the intensity-response relationship of the PhNR

Effect of dietary fiber, genetic strain and age on the digestive metabolism of broiler chickens

In this study, 360 male broilers, out of which 240 of a fast-growing strain (Cobb500), and 120 of a slow-growing strain (Label Rouge), were used to evaluate the effect of dietary fiber on digesta transit time and digestive metabolism during the period of 1 to 42 days of age. A completely randomized experimental design with a 3x2 factorial arrangement was applied, consisting of three groups of birds (slow-growing – SG; fast-growing fed ad libitum – FGAL; and fast-growing pair-fed with SG broilers – FGPF) and two iso-protein diets (a 3100 kcal ME/kg low-fiber diet –LFD- and a 2800 kcal ME/ kg high-fiber diet –HFD- with 14% wheat bran and 4% oat hulls). HFD-fed birds presented lower ME retention (p < 0.001) and lower dry matter metabolizability (DMM) (p < 0.001), which is possibly related to the shorter digesta transit time observed in these birds (p < 0.001). DMM was reduced with age, whereas metabolizable energy remained almost constant (p < 0.001) independently of strain. This may be related to the increase in feed intake as birds age. The slowgrowing strain did not present better utilization of the high-fiber diet as compared to the fast-growing strain in none of the analyzed ages, even though showing a significant better use of fiber and dietary energy from 31 days of age

Rules, Practices and Information Technology (IT): A Trifecta of Organizational Regulation

As information technology (IT) based regulation has become critical and pervasive for contemporary organizing, Information Systems research turns mostly a deaf ear to the topic. Current explanations of IT-based regulation fit into received frameworks such as structuration theory, actor-network theory, or neo-institutional analyses but fail to recognize the unique capacities IT and related IT based regulatory practices offer as a powerful regulatory means. Any IT-based regulation system is made up of rules, practices and IT artifacts and their relationships. We propose this trifecta as a promising lens to study IT-based regulation in that it sensitizes scholars into how IT artifacts mediate rules and constitute regulatory processes embracing rules, capacities of IT endowed by the artifact, and organizational practices. We review the concepts of rules and IT-based regulation and identify two gaps in the current research on organizational regulation: 1)the critical role of sense-making as part of IT based regulation, and 2)the challenge of temporally coupling rules and their enactment during IT based regulation. To address these gaps we introduce the concept of regulatory episode as a unit of analysis for studying IT-based regulation. We also formulate a tentative research agenda for IT-based regulation that focuses on tensions triggered by the three key elements of the IT-based regulatory processes

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal