192 research outputs found
Populism, Hegemony, and the Politics of Natural Resource Extraction in Evo Morales's Bolivia
Unidad de excelencia MarĂa de Maeztu MdM-2015-0552Is populism necessary to the articulation of counter-hegemonic projects, as Laclau has long argued? Or is it, as ĆœiĆŸek maintains, a dangerous strategy, which inevitably degenerates into ideological mystification and reactionary postures? In this paper, I address this question by exploring the politics of discourse in Evo Morales's Bolivia. While, in the years leading to the election of Morales, a populist ideological strategy was key to challenging neoliberal forces, once the hegemony of the new power bloc was stabilised, indigenous demands for emancipatory socio-environmental change began to be perceived as a threat to resource-based accumulation. In this context, the populist signifiers that originated in indigenous-popular struggles were used by the Morales government to legitimise repression of the indigenous movement. I argue, therefore, that ideological degeneration signals a problem not with populism per se, but rather with the class projects and shifting correlations of forces that underpin it in changing conjunctures
Can the State Learn to Live Well? Ălvaro GarcĂa Linera as an Intellectual of the State and Interpreter of History
Long-term quality assurance of fMRI and MRS on a 3.0T clinical scanner
Functional MRI (fMRI) and Magnetic Resonance Spectroscopy (MRS) are being increasingly used in clinical protocols. Subsequenly it is crucial to develop a routine quality assurance protocol (QA)of both techniques. This work describes a long-term variability study, as apart of the QA of fMRI and MRS on our institution clinical 3.0 T MR scanner
Changes in the Papez Circuit in early stages of Alzheimer's Disease
Alzheimer's disease (AD) is the most common cause of demenMa. Neuronal and synapMc losses occur iniMally and predominantly in the medial temporal lobe structures including hippocampus, amygdala and thalamus, structures that belong to the Papez circuit. The integrity of the connecMons amongst them is essenMal for episodic memory, which is specifically impaired in AD. For this reason we have invesMgated the degeneraMon paRern of subcorMcal structures and its relaMon to early stages of AD, i.e. Mild CogniMve Impairment (MCI), both in the amnesic and mulMdomain types using structural magneMc resonance imaging (using a 3T GE scanner) and VBMâDARTEL
Estudio de prevalencia y perfil clĂnico de la enfermedad reumĂĄtica infantil en nuestro medio
The partial volume effect in the quantification of 1H magnetic resonance spectroscopy in Alzheimer's disease and aging
[Abstract] 1H-MRS variability increases due to normal aging and also as a result of atrophy in grey and white matter caused by neurodegeneration. In this work, an automatic process was developed to integrate data from spectra and high-resolution anatomical images to quantify metabolites, taking into account tissue partial volumes within the voxel of interest avoiding additional spectra acquisitions required for partial volume correction. To evaluate this method, we use a cohort of 135 subjects (47 male and 88 female, aged between 57 and 99 years) classified into 4 groups: 38 healthy participants, 20 amnesic mild cognitive impairment patients, 22 multi-domain mild cognitive impairment patients, and 55 Alzheimer's disease patients. Our findings suggest that knowing the voxel composition of white and grey matter and cerebrospinal fluid is necessary to avoid partial volume variations in a single-voxel study and to decrease part of the variability found in metabolites quantification, particularly in those studies involving elder patients and neurodegenerative diseases. The proposed method facilitates the use of 1H-MRS techniques in statistical studies in Alzheimer's disease, because it provides more accurate quantitative measurements, reduces the inter-subject variability, and improves statistical results when performing group comparisons
Effect of water T2 shortening in the quantification of in-vitro proton MR spectroscopy
Short communication[Abstract] PURPOSE. This work studies the relationship between in-vitro Proton Magnetic Resonance Spectroscopy metabolite quantification and water T2 decay.
MATERIALS AND METHODS. An in-vitro correspondence is established between the iron accumulation and the shortening of water T2 relaxation times using seven spherical phantoms, 6 of them were doped with an increasing concentration of iron metal nanoparticles solution. This is later proposed as a source of error during the LCModel metabolite quantification of either absolute concentrations or ratios.
RESULTS. The Pearson's correlation coefficient between water T2 values against absolute metabolite concentrations was on average [r] = 0.97 and on average [r] = 0.85 for metabolite ratios.
CONCLUSION. These results suggest that the shortening of T2 values should be taken into account when performing metabolite quantification. Also, the need of demonstrated similar results in in-vivo studies, since the presence of iron deposits or other factors affecting the water T2 decay measurements could explain part of the inter-subject variability in the metabolite concentration and ratio quantification
Refining memory assessment of elderly people with cognitive impairment:Insights from the short-term memory binding test
Alzheimerâs disease (AD) affects temporary memory for bound features more remarkably than for individual features. Such selective impairments manifest from presymptomatic through dementia stages via titration procedures. A recent study suggested that without titration and with high memory load the binding selectivity may disappear in people at risk of AD such as those with Mild Cognitive Impairment (MCI). We compared data from two studies on temporary binding which assessed people with MCI and controls using different memory loads (2 or 3 items). Selective binding impairments were found in MCI, but relative to controls, such selectivity was contingent upon memory load (i.e., present with 2 items). Further analysis with MCI people who tested positive to neuroimaging biomarkers (i.e., hippocampal atrophy) confirmed that this specific binding impairments are a feature of prodromal AD. The temporary binding task has been recently suggested by consensus papers as a potential screening tool for AD. The results presented here inform on task properties that can maximise the reliability of this new assessment tool for the detection of memory impairments in prodromal cases of AD
Indigenous Peasant âOthernessâ: Rural Identities and Political Processes in Bolivia
Since Morales's election, rural movements have become the new protagonists of Bolivian politics. Previous analyses have emphasised their active role in shaping national politics, often focusing on those organisations as a compact block. However, their relationship is marked by both cooperation and fragmentation. This article provides a narrative of Bolivian socio-political history over the last 60âyears, establishing four main phases of identitarian articulations/disarticulations. It demonstrates the high degree of interdependence and fluidity of ethnic and class identities, as well as their interconnections with the broader socio-political context and the national legal and institutional changes
Structural changes after videogame practice related to a brain network associated with intelligence
Here gray and white matter changes after four weeks of videogame practice were analyzed using optimized voxel-based morphometry (VBM), cortical surface and cortical thickness indices, and white matter integrity computed from several projection, commissural, and association tracts relevant to cognition. Beginning with a sample of one hundred young females, twenty right handed participants were recruited for the study and assigned to a practice or a control group carefully matched by their general cognitive ability scores. After the first scan, the practice group played âProfessor Layton and The Pandora's Boxâ 4 h per week during four weeks. A second scan was obtained at the end of practice and intelligence was measured again. Image analyses revealed gray and white matter changes in the practice group. Gray matter changes theoretically relevant for intelligence were observed for the practice group mainly in frontal clusters (Brodmann areas 9 and 10) and also in smaller parietal and temporal regions. White matter findings were focused in the hippocampal cingulum and the inferior longitudinal fasciculus. These gray and white matter changes presumably induced by practice did not interact with intelligence tests' scores
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