255 research outputs found
Economic issues provokes hazardous landing decision-making by enhancing the activity of "emotional" neural pathways
The analysis of aeronautical accidents highlights the fact that some airline pilots demonstrate a trend to land whereas the approach is not well stabilized. This behavior seems to be the consequence of various factors, including financial issues. Our hypothesis is that financial constraints modulate the brain circuitry of emotion and reward, in particular via the interactions between two prefrontal structures: the dorsolateral prefrontal cortex(DLPFC), main center of the executive functions (EFs), high level cognitive abilities, and the ventromedial prefrontal cortex (VMPFC), structure linked with the limbic system, major substratum of emotional processes. In our experiment, participants performed a simplified task of landing in which the level of uncertainty and the financial incentive were manipulated. A preliminary behavioral experiment (n = 12) was conducted. A similar second experiment using functional magnetic resonance imaging (fMRI) is in progress and a case study only is reported here. The behavioral data showed that the participants made more risky decision to land in the financial incentive condition in comparison to the neutral condition, where no financial incentive was delivered. This was particularly true when the uncertainty was high. The functional neuroimaging results showed that the reasoning performed in neutral condition resulted in enhanced activity in DLPFC. On the contrary, under the influence of the financial incentive, VMPFC activity was increased. These results showed the effectiveness of the financial incentive to bias decision-making toward a more risky and less rational behavior from a safety point of view. Functional neuroimaging data showed a shift from cold to hot reasoning in presence of the financial incentive, suggesting that pilot erroneous trend to land could be explained by a temporary perturbation of the decision-making process due to the negative emotional consequences associated with the go-around
Decontamination on pork carcasses: qualification of thermic treatment by thermal imaging
Singeing improves the visual quality of rind in pig slaughterhouses. In addition, the thermic inactivation allows the bacterial contamination of carcass surfaces to be reduced. However, the thermal image of pig carcasses shows temperature differences along the carcasses.
The objective of this study was to develop a method to analyze a thermal image. After defining an imaging protocol adapted to pig slaughterhouses, image analysis was carried out with the free software: ImageJ©. Three methods were developed in order to preserve the spatial arrangement and time information for each measurement: (1) Method by line profile, (2) Method by mouse over, (3) Method by mouse over and line profile. Moreover, the method had to be simple and accurate. After a statistical comparison (mean, variance, distribution) between the three methods on 20 carcasses, the method by line profile was validated to analyze the characteristics of heat treatment in four pig slaughterhouses during process.
This validated method of image acquisition and analysis was a tool used to measure the temperature variability on carcasses. The reference temperature was the temperature of carcasses after 90 minutes of continuous process. This method confirmed temperature differences on carcass surfaces (the top part of the carcass is warmer than the bottom part within a range of 2-7°C) and within a production day; the lowest temperatures were observed when the process started or re-started (after breaks), on average 4°C. These temperature variations along the working day were observed in every slaughterhouse studied. Bacterial contamination was evaluated on carcasses prior and following singeing for two heating settings. Results were similar to the literature (reduction of 3 Log10 CFU/cmÂČ of the Aerobic colony counts).
With this pragmatic method, companies could have access to a measurement tool not only for characterizing, checking, optimizing and qualifying the efficiency of singeing, but also for investigating all thermic treatments on meat in slaughterhouses
Neuroimaging and Neurolaw: Drawing the Future of Aging
Human brain-aging is a complex, multidimensional phenomenon. Knowledge of the numerous aspects that revolve around it is therefore essential if not only the medical issues, but also the social, psychological, and legal issues related to this phenomenon are to be managed correctly. In the coming decades, it will be necessary to find solutions to the management of the progressive aging of the population so as to increase the number of individuals that achieve successful aging. The aim of this article is to provide a current overview of the physiopathology of brain aging and of the role and perspectives of neuroimaging in this context. The progressive development of neuroimaging has opened new perspectives in clinical and basic research and it has modified the concept of brain aging. Neuroimaging will play an increasingly important role in the definition of the individual's brain aging in every phase of the physiological and pathological process. However, when the process involved in age-related brain cognitive diseases is being investigated, factors that might affect this process on a clinical and behavioral level (genetic susceptibility, risks factors, endocrine changes) cannot be ignored but must, on the contrary, be integrated into a neuroimaging evaluation to ensure a correct and global management, and they are therefore discussed in this article. Neuroimaging appears important to the correct management of age-related brain cognitive diseases not only within a medical perspective, but also legal, according to a wider approach based on development of relationship between neuroscience and law. The term neurolaw, the neologism born from the relationship between these two disciplines, is an emerging field of study, that deals with various issues in the impact of neurosciences on individual rights. Neuroimaging, enhancing the detection of physiological and pathological brain aging, could give an important contribution to the field of neurolaw in elderly where the full control of cognitive and volitional functions is necessary to maintain a whole series of rights linked to legal capacity. For this reason, in order to provide the clinician and researcher with a broad view of the brain-aging process, the role of neurolaw will be introduced into the brain-aging context
Broad white matter impairment in multiple system atrophy.
Multiple system atrophy (MSA) is a rare neurodegenerative disorder characterized by the widespread aberrant accumulation of α-synuclein (α-syn). MSA differs from other synucleinopathies such as Parkinson's disease (PD) in that α-syn accumulates primarily in oligodendrocytes, the only source of white matter myelination in the brain. Previous MSA imaging studies have uncovered focal differences in white matter. Here, we sought to build on this work by taking a global perspective on whole brain white matter. In order to do this, in vivo structural imaging and diffusion magnetic resonance imaging were acquired on 26 MSA patients, 26 healthy controls, and 23 PD patients. A refined whole brain approach encompassing the major fiber tracts and the superficial white matter located at the boundary of the cortical mantle was applied. The primary observation was that MSA but not PD patients had whole brain deep and superficial white matter diffusivity abnormalities (p <â.001). In addition, in MSA patients, these abnormalities were associated with motor (Unified MSA Rating Scale, Part II) and cognitive functions (Mini-Mental State Examination). The pervasive whole brain abnormalities we observe suggest that there is widespread white matter damage in MSA patients which mirrors the widespread aggregation of α-syn in oligodendrocytes. Importantly, whole brain white matter abnormalities were associated with clinical symptoms, suggesting that white matter impairment may be more central to MSA than previously thought
Patterns of grey matter loss associated with motor subscores in early Parkinson's disease
Classical motor symptoms of Parkinson's disease (PD) such as tremor, rigidity, bradykinesia, and axial symptoms are graded in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) III. It is yet to be ascertained whether parkinsonian motor symptoms are associated with different anatomical patterns of neurodegeneration as reflected by brain grey matter (GM) alteration. This study aimed to investigate associations between motor subscores and brain GM at voxel level. High resolution structural MRI T1 scans from the Parkinson's Progression Markers Initiative (PPMI) repository were employed to estimate brain GM intensity of PD subjects. Correlations between GM intensity and total MDS-UPDRS III and its four subscores were computed. The total MDS-UPDRS III score was significantly negatively correlated bilaterally with putamen and caudate GM density. Lower anterior striatal GM intensity was significantly associated with higher rigidity subscores, whereas left-sided anterior striatal and precentral cortical GM reduction were correlated with severity of axial symptoms. No significant morphometric associations were demonstrated for tremor subscores. In conclusion, we provide evidence for neuroanatomical patterns underpinning motor symptoms in early PD
Intracranial fluids dynamics alterations and cortical thickness
Objectives: The issue of cortical atrophy is important in normal aging and disease since it is associated with cognitive and physical impairments. Cortical atrophy is potentially a relevant biomarker for the early diagnosis of Alzheimerâs disease (AD). The vascular component is also an integral part of AD and other late-life neurodegenerative diseases. Abnormalities in blood flow appear before accumulation of abnormal proteins in AD. The occlusion of capillaries by neutrophils are significantly higher in AD animal models than control and reduction of those occlusions with an antibody increases both blood flow and cognitive capacities. Vascular alterations lead to hypoperfusion, oxidative stress and inflammation, which in turn lead to damage of neurons, glia and myelin, predominantly in the white mater. Implication of vascular pathologies for gray matter remains unclear. A recent study showed that altered cerebral hemodyamics in asymptomatic carotid artery stenosis is associated with cortical thinning. However there is no proven link between vascular pathologies and cortical thinning. We propose to explore brain aging with a combined biomechanical and imaging approach in order to assess both fluid dynamics alterations and brain structural modifications. We hypothesize that there is a link between altered cerebral hemodynamics and loss of cortical thickness during brain aging.
Methods: 80 patients suspected of hydrocephalus were prospectively involved. All patients complain of gait alteration, urinary difficulties, mild apathy and ventriculomegaly on brain imaging. They all underwent brain MRI with T1 weighted images to quantify cortical thickness and phase contrast images to measure arterial, venous and CSF velocities. Lumbar infusion test was also performed to gauge lumbar pressure, a surrogate marker of intracranial pressure (ICP), and CSF dynamics. The cortical volumetric segmentation was done by an automatic post-processing analysis with FREESURFER and local thicknesses were assessed with CorThiZon. Venous, arterial and CSF velocities were measured from PCMRI with BIOFLOWIMAGE software. ICP and CSF dynamics were extracted form infusion tests. Pearson correlations were calculated between cortical thickness and arterial, venous and CSF velocities, but also ICP and derived indices.
Results: Mean cortical thickness is positively correlated with mean ICP (r=0.48, p=0.001), ICP pulse amplitude (r=0.43, p=0.001), arterial flow (r=0.44, p=0.001), aqueductal CSF flow(r=046, p=0.001), but negatively correlates with venous flow (r=-0.44, p=0.001). Conclusions: We demonstrate that cortical thickness is correlated with arterial and CSF pulsatility. The causality is more complex since it involves local microcirculation that could not be directly measured. However the association between intracranial pulsatility and gray matter thickness suggests that there is a relationship between vascular alterations at the macroscale level and the pathobiology of cortical atrophy
Shorter sleep duration and better sleep quality are associated with greater tissue density in the brain
Poor sleep quality is associated with unfavorable psychological measurements, whereas sleep duration has complex relationships with such measurements. The aim of this study was to identify the associations between microstructural properties of the brain and sleep duration/sleep quality in a young adult. The associations between mean diffusivity (MD), a measure of diffusion tensor imaging (DTI), and sleep duration/sleep quality were investigated in a study cohort of 1201 normal young adults. Positive correlations between sleep duration and MD of widespread areas of the brain, including the prefrontal cortex (PFC) and the dopaminergic systems, were identified. Negative correlations between sleep quality and MD of the widespread areas of the brain, including the PFC and the right hippocampus, were also detected. Lower MD has been previously associated with more neural tissues in the brain. Further, shorter sleep duration was associated with greater persistence and executive functioning (lower Stroop interference), whereas good sleep quality was associated with states and traits relevant to positive affects. These results suggest that bad sleep quality and longer sleep duration were associated with aberrant neurocognitive measurements in the brain in healthy young adults
Cuestiones epistemolĂłgicas y estudios de caso
En un paĂs -Francia- donde el campo del teatro estĂĄ estructurado culturalmente durante dĂ©cadas, el Teatro Aplicado es una nociĂłn que a menudo aparece como ancillar, frente a un arte institucionali-zado, incluso mirificado. Por un lado, estarĂa el Teatro, puro, noble, autĂ©ntico y por otro, estarĂan sus avatares: el teatro de empresa, el teatro para el desarrollo personal, el teatro para patologĂas, etc. Si tienen la misma fuente, su consanguinidad no deja de asustar. ÂżcĂłmo pueden unos artistas que crean alejados de cualquier coacciĂłn exterior pertenecer a la misma familia del teatro que unos actores o directores que "obedecen" a un encargo, en un contexto especĂfico, con un pĂșblico muchas veces participantes de talleres ... y que son por tanto prisioneros, en cierto modo, de un arte instru-mental izado? A este problema Ă©tico, este libro intenta responder, a travĂ©s de ejemplos concretos, para una mayor comprensiĂłn inrerculrural Francia/ Colombia.In a country -France- where the field of theater has been culturally structured for decades, Applied Theater is a notion that often appears as an ancillary, in the face of an institutionalized, even mirified, art. On the one hand, there would be the Theater, pure, noble, authentic and on the other, there would be its ups and downs: company theater, theater for personal development, theater for pathologies, etc. If they have the same source, their consanguinity does not stop frightening. How can some artists who create far from any external coercion belong to the same theater family as some actors or directors who "obey" a commission, in a specific context, with an audience that is often workshop participants... are they therefore prisoners, in a certain way, of an instrumented art? To this ethical problem, this book tries to respond, through concrete examples, for a greater intercultural understanding France/ Colombia.Bogot
Clinical heterogeneity of neuro-inflammatory PET profiles in early Alzheimerâs disease
The relationship between neuroinflammation and cognition remains uncertain in early Alzheimerâs disease (AD). We performed a cross-sectional study to assess how neuroinflammation is related to cognition using TSPO PET imaging and a multi-domain neuropsychological assessment. A standard uptake value ratio (SUVR) analysis was performed to measure [18F]-DPA-714 binding using the cerebellar cortex or the whole brain as a (pseudo)reference region. Among 29 patients with early AD, the pattern of neuroinflammation was heterogeneous and exhibited no correlation with cognition at voxel-wise, regional or whole-brain level. The distribution of the SUVR values was independent of sex, APOE phenotype, early and late onset of symptoms and the presence of cerebral amyloid angiopathy. However, we were able to demonstrate a complex dissociation as some patients with similar PET pattern had opposed neuropsychological profiles while other patients with opposite PET profiles had similar neuropsychological presentation. Further studies are needed to explore how this heterogeneity impacts disease progression
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