390 research outputs found
Cenozoic lacustrine deposits in the Duero Basin (Spain)
Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu
South-western Duero and Ciudad Rodrigo basins: infill and dissection of a Tertiary basin
In the soult western sector of the intracontinetal Duero basin, the post-Hercynian sedimentary record consist of Upper Cretaceous to Quaternary terrestrial sediments. Climates shifted from tropical, with poorly defined seansos (end of Cretaceous), to Mediterranean (Neogene). Tertiary deposits are divided into three tectonographic completes. The Late Cretaceous-Paleocene, related to the end of the Mesozoic cycle, is caractericed by a well developed weathering profile that eroded later. The Eocene Oligocene, formed during the morpho-structural definition of the actual basin boundaries, consists of three unconformity-bounded units related to successive tectonic events of the Alpine Orogeny by the cnd of this cycle, progressive incision of the Atlantic nuvial network led to capture of the fluvial systems of the southern Duero basin and degradation (emptying) began. The Miocene-Phocene, related to and extensional tectonic regime represents the spreading of exorheik conditions to the whole basin that marked a complete hydrugraphic reorganisation. Deposition and aggradation continued in more central areas of the basin until the end of the Neogene, coeval with degradation of the south-western corner of the Duero Basin. The coexistence resulted from differential subsidence, hinge lines (uplift zones) separated sub-basins, and the dynamics of capture processes
A first approach to the multipurpose relational database server
In this paper, an architecture and an implementation of a multipurpose relational database server are proposed. This architecture enables classical queries to be executed, deductions to be made, and data mining operations
to be performed on fuzzy or classical data. The proposal of this integration is to combine several ways of querying different types of data. In order to achieve this, a combination of existing metaknowledge bases and new data
catalog elements is presented. We also introduce a language for handling all these data coherently and uniformly on the basis of classical SQL sentences
The Duero Basin: a general overview
The Duero basin occupies a large area in the north-west of the Iberian Península. It has ao approximately quadrangular shape, and three of its four corners are the sites of distinctive sub-basins that extend outwards from the main basic. The different margins of lhe sub-basins and the main basic tend to have distinctive histories of tectonic and sedimentary evolution
Lacustrine Neogene systems of the Duero Basin: evolution and controls
Vertical aggradation of Neogene fluvial and lacustrine deposits occurred until the Late Neogene in central and northem areas of the Duero Basin, coeval with river incision in the southwestern corner of the basin. The whole basin became exorheic in the Latest Neogene. We have differentiated five tectonosedimentary units (TSUs) of basinal extent, bounded by unconfonnities or breaks in the sedimentary record. Deposits in each TSU consist of alluvial-fan deposits in areas close to the active northern and eastern margins, and fluvial deposits along the western margin. These systems converged in the lower, subsiding areas of the basin occupied by carbonate-evaporite lacustrine systems. Tectonics and climate controlled sedimentation. The main faults active from the Neogene to the Present reflect Late Hercynian basement fractures that were re-activated during the Alpine Orogeny, both fracturing blocks and modifying landscapes, and creating or modifying the areas of subsidence. Analysis of climatic variations during the Miocene shows that deposition of saline materials occurred in dry TSUs (1, 2) and, particularly, in humid TSUs (3,4). Climate does not seem to have been a determining factor for the formation of evaporites. However, it was a very important factor in determining both the amount of water that reached the basin and, eventually, also the extent of the lacustrine systems
Entrenamiento de las señales corticales a través de un sistema BMI-EEG, evolución e intervención. A propósito de un caso = Training cortical signals by means of a BMI-EEG system, its evolution and intervention. A case report
INTRODUCTION:
In the last years, new technologies such as the brain-machine interfaces (BMI) have been incorporated in the rehabilitation process of subjects with stroke. These systems are able to detect motion intention, analyzing the cortical signals using different techniques such as the electroencephalography (EEG). This information could guide different interfaces such as robotic devices, electrical stimulation or virtual reality.
CASE REPORT:
A 40 years-old man with stroke with two months from the injury participated in this study. We used a BMI based on EEG. The subject's motion intention was analyzed calculating the event-related desynchronization. The upper limb motor function was evaluated with the Fugl-Meyer Assessment and the participant's satisfaction was evaluated using the QUEST 2.0. The intervention using a physical therapist as an interface was carried out without difficulty.
CONCLUSIONS:
The BMI systems detect cortical changes in a subacute stroke subject. These changes are coherent with the evolution observed using the Fugl-Meyer Assessment
Moderate acute alcohol intoxication has minimal effect on surround suppression measured with a motion direction discrimination task.
A well-studied paradox of motion perception is that, in order to correctly judge direction in high-contrast stimuli, subjects need to observe motion for longer in large stimuli than in small stimuli. This effect is one of several perceptual effects known generally as "surround suppression." It is usually attributed to center-surround antagonism between neurons in visual cortex, believed to be mediated by GABA-ergic inhibition. Accordingly, several studies have reported that this index of surround suppression is reduced in groups known to have reduced GABA-ergic inhibition, including older people and people with schizophrenia and major depressive disorder. In this study, we examined the effect on this index of moderate amounts of ethanol alcohol. Among its many effects on the nervous system, alcohol potentiates GABA-ergic transmission. We therefore hypothesized that it should further impair the perception of motion in large stimuli, resulting in a stronger surround-suppression index. This prediction was not borne out. Alcohol consumption slightly worsened duration thresholds for both large and small stimuli, but their ratio did not change significantly
Tremor severity in Parkinson’s disease and cortical changes of areas controlling movement sequencing: a preliminary study.
. There remains much to learn about the changes in cortical anatomy that are associated with tremor severity in Parkinson’s disease (PD). For this reason, we used a combination of structural neuroimaging to measure cortical thickness and neurophysiological studies to analyze whether PD tremor was associated with cortex integrity. Magnetic resonance imaging and neurophysiological assessment were performed in 13 nondemented PD patients (9 women, 69.2%) with a clearly tremor-dominant phenotype. Cortical reconstruction and volumetric segmentation was performed with the Freesurfer image analysis software. Assessment of tremor was performed by means of high-density surface electromyography (hdEMG) and inertial measurement units (IMUs). Individual motor unit discharge patterns were identified from surface hdEMG and tremor metrics quantifying motor unit synchronization from IMUs were defined. Increased motor unit synchronization (i.e., more severe tremor) was associated with cortical changes (i.e., atrophy) in dorsal premotor cortices, left posterior parietal cortex, left lateral orbitofrontal cortex, cingulate cortex bilaterally, left posterior and transverse temporal cortex, and left occipital lobe, as well as reduced left middle temporal volume. Given that the majority of these areas are involved in controlling movement sequencing, our results support Albert’s classic hypothesis that PD tremor may be the result of an involuntary activation of a program of motor behavior used in the genesis of rapid voluntary alternating movements.pre-print670 K
A data mining approach using cortical thickness for diagnosis and characterization of essential tremor.
Essential tremor (ET) is one of the most prevalent movement disorders. Being that it is a common
disorder, its diagnosis is considered routine. However, misdiagnoses may occur regularly. Over the
past decade, several studies have identified brain morphometric changes in ET, but these changes
remain poorly understood. Here, we tested the informativeness of measuring cortical thickness for
the purposes of ET diagnosis, applying feature selection and machine learning methods to a study
sample of 18 patients with ET and 18 age- and sex-matched healthy control subjects. We found that
cortical thickness features alone distinguished the two, ET from controls, with 81% diagnostic accuracy.
More specifically, roughness (i.e., the standard deviation of cortical thickness) of the right inferior
parietal and right fusiform areas was shown to play a key role in ET characterization. Moreover, these
features allowed us to identify subgroups of ET patients as well as healthy subjects at risk for ET. Since
treatment of tremors is disease specific, accurate and early diagnosis plays an important role in tremor
management. Supporting the clinical diagnosis with novel computer approaches based on the objective
evaluation of neuroimage data, like the one presented here, may represent a significant step in this
direction.post-print1720 K
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