The Monty Hall problem revisited: Autonomic arousal in an inverted version of the game.

The asymmetry of autonomic arousal for potential losses and gains was assessed by the galvanic skin response (GSR) of participants playing classic and inverted versions of the Monty Hall problem (MHP). In both versions, the prize remained the same (a pen valued at £10 for the right answer), but in the modified version, prizes were received prior to choosing the door. Both experimental groups showed increased levels of GSR while completing the task, demonstrating increased autonomic arousal during the game. However, a robust difference in GSR was detected between classic and inverted versions of the MHP, thus demonstrating the differing autonomic arousal involved in deciding between the alternatives presented by the game. Participants experienced a stronger autonomic response when they could lose the prize than when they could win the prize. This experiment presents the first demonstration of this effect on the MHP. The stronger autonomic arousal for the inverted task may indicate a stronger emotional reaction and/or greater attentional focus than for the standard version of the task. These data demonstrate that potential losses increase arousal in more complex tasks than is typically shown.

Supra and infratentorial ectopic schwannoma mimicking a meningioma.

We report the case of a supra and infratentorial ectopic schwannoma, mimicking a meningioma, that was surgically resected on a 75-year-old man, with a history of progressive visual loss and headaches. MRI was in favour of an occipital, cystic, tentorial-based meningioma extending to the posterior fossa, with signs of intratumoral haemorrhage. This is a unique case because of the rare type of lesion, in a very atypical location, completely unexpected by the preoperative imaging analysis, and to the best of our knowledge it is the oldest patient reported in the literature with this kind of tumour.

A high performance cost-effective digital complex correlator for an X-band polarimetry survey.

The detailed knowledge of the Milky Way radio emission is important to characterize galactic foregrounds masking extragalactic and cosmological signals. The update of the global sky models describing radio emissions over a very large spectral band requires high sensitivity experiments capable of observing large sky areas with long integration times. Here, we present the design of a new 10 GHz (X-band) polarimeter digital back-end to map the polarization components of the galactic synchrotron radiation field of the Northern Hemisphere sky. The design follows the digital processing trends in radio astronomy and implements a large bandwidth (1 GHz) digital complex cross-correlator to extract the Stokes parameters of the incoming synchrotron radiation field. The hardware constraints cover the implemented VLSI hardware description language code and the preliminary results. The implementation is based on the simultaneous digitized acquisition of the Cartesian components of the two linear receiver polarization channels. The design strategy involves a double data rate acquisition of the ADC interleaved parallel bus, and field programmable gate array device programming at the register transfer mode. The digital core of the back-end is capable of processing 32 Gbps and is built around an Altera field programmable gate array clocked at 250 MHz, 1 GSps analog to digital converters and a clock generator. The control of the field programmable gate array internal signal delays and a convenient use of its phase locked loops provide the timing requirements to achieve the target bandwidths and sensitivity. This solution is convenient for radio astronomy experiments requiring large bandwidth, high functionality, high volume availability and low cost. Of particular interest, this correlator was developed for the Galactic Emission Mapping project and is suitable for large sky area polarization continuum surveys. The solutions may also be adapted to be used at signal processing subsystem levels for large projects like the square kilometer array testbeds.

Combining Different Tools for EEG Analysis to Study the Distributed Character of Language Processing.

Recent studies on language processing indicate that language cognition is better understood if assumed to be supported by a distributed intelligent processing system enrolling neurons located all over the cortex, in contrast to reductionism that proposes to localize cognitive functions to specific cortical structures. Here, brain activity was recorded using electroencephalogram while volunteers were listening or reading small texts and had to select pictures that translate meaning of these texts. Several techniques for EEG analysis were used to show this distributed character of neuronal enrollment associated with the comprehension of oral and written descriptive texts. Low Resolution Tomography identified the many different sets (s i ) of neurons activated in several distinct cortical areas by text understanding. Linear correlation was used to calculate the information H(e i ) provided by each electrode of the 10/20 system about the identified s i . H(e i ) Principal Component Analysis (PCA) was used to study the temporal and spatial activation of these sources s i . This analysis evidenced 4 different patterns of H(e i ) covariation that are generated by neurons located at different cortical locations. These results clearly show that the distributed character of language processing is clearly evidenced by combining available EEG technologies.

Relation between magnetic parameters and nematode abundance in agricultural soils of Portugal--a multidisciplinary study in the scope of environmental magnetism.

Soil is composed of different types of particles which are either natural or of anthropogenic origin. Anthropogenic particles are often related to the presence of heavy metals and thus provide information on soil quality. Magnetic parameters can detect the presence of such particles and may be used as a proxy for environmental pollution. This study explores the relationships between magnetic particles and the nematofauna of agricultural soils. Magnetic, pedological, microscopy and nematological analyses were conducted in soils collected from major regions of potato production in Portugal. The magnetic characterisation of soils identified regions with magnetic particles with possible anthropogenic origin. Microscopy analysis revealed the presence of spherical particles dominantly composed of Fe, O and C. A positive and significant relationship was found between saturation isothermal remanent magnetisation (SIRM) and mass-specific susceptibility (χ), confirming the importance the ferrimagnetic fraction to magnetic properties. The nematode communities were composed of nematodes belonging to four trophic groups (bacterial feeding, plant feeders, fungal feeders and omnivores/predators). The relationships between magnetic parameters and the nematodes showed that (1) S-25 has a linear correlation with number of nematodes per kilogram of soil and with plant feeders' trophic group and (2) SIRM correlates with the bacterial feeders trophic group. This study reveals that magnetic proxies may provide means for detecting regions with higher levels of pollution, possibly related to heavy metals. Due to the large background variability found in magnetic parameters, the sampling spacial mesh should to be further refined and the input of magnetic minerals needs to be locally calibrated.

Brain activity and medical diagnosis: an EEG study.

BACKGROUND: Despite new brain imaging techniques that have improved the study of the underlying processes of human decision-making, to the best of our knowledge, there have been very few studies that have attempted to investigate brain activity during medical diagnostic processing. We investigated brain electroencephalography (EEG) activity associated with diagnostic decision-making in the realm of veterinary medicine using X-rays as a fundamental auxiliary test. EEG signals were analysed using Principal Components (PCA) and Logistic Regression Analysis RESULTS: The principal component analysis revealed three patterns that accounted for 85% of the total variance in the EEG activity recorded while veterinary doctors read a clinical history, examined an X-ray image pertinent to a medical case, and selected among alternative diagnostic hypotheses. Two of these patterns are proposed to be associated with visual processing and the executive control of the task. The other two patterns are proposed to be related to the reasoning process that occurs during diagnostic decision-making. CONCLUSIONS: PCA analysis was successful in disclosing the different patterns of brain activity associated with hypothesis triggering and handling (pattern P1); identification uncertainty and prevalence assessment (pattern P3), and hypothesis plausibility calculation (pattern P2); Logistic regression analysis was successful in disclosing the brain activity associated with clinical reasoning success, and together with regression analysis showed that clinical practice reorganizes the neural circuits supporting clinical reasoning.

Complex sacral fracture.

We reported a case of a patient with suspected cauda equina syndrome secondary to sacral fracture, after sustaining a fall. The difficulty in early diagnosis of complex sacral fractures and the lack of clearly defined guidelines for treatment are highlighted. Thorough clinical examination is mandatory, in order to make an adequate initial assessment and follow symptoms progression and response to treatment. The threshold for performing CT imaging (or MRI, if advised), when suspecting sacral fracture and neurological compromise, should be low. A multidisciplinary approach, with contributions from orthopaedic and/or neurosurgical surgery and physiatry, should be the gold standard of treatment. In this particular case, conservative management and close follow-up led to a significant improvement of problems and a good final outcome, showing that surgical decompression is not the only valid option and that further prospective studies are needed, regarding patient selection and timing of intervention.

Hematoma iatrogênico simulando lesão tumoral intradural lombar / Iatrogenic hematoma mimicking lumbar intradural tumoral lesion

Em um quadro clínico de lombociatalgia, o diagnóstico diferencial engloba uma variedade de possíveis etiologias. Descreve-se um caso de um doente do sexo feminino, com história de lombociatalgia incapacitante relacionada com hematoma intradural, consequência de punção lombar e drenado após laminectomia lombar. São revistas as várias séries descritas na literatura, assim como são discutidos os diferentes fatores de risco, quadros clínicos e estratégias de prevenção e tratamento.

In the presence of lumbar radicular pain, the differential diagnosis includes several possible etiologies. Here is described a case of a female patient with incapacitating low back pain and lumbar radicular pain caused by an intradural hematoma, consequence of lumbar puncture, surgically drained after laminectomy. The several series in the literature describing these cases are revised, and the different risk factors, clinical pictures, prevention and treatment strategies are discussed.

[Glioblastoma multiforme mimicking limbic encephalitis]. / Glioblastoma multiforme mimetizando encefalite límbica.

Selective and bilateral involvement of the limbic system by gliomas is rarely reported. The authors report the case of a 58 years-male complaining of short-term memory loss in the preceding three weeks. The initial MRI revealed areas of hyperintensity on T2 and FLAIR sequences involving both hippocampus, amygdala, parahippocampus gyrus and the fornix, with contrast enhancement in the right mesial temporal region. Limbic encephalitis diagnosis was assumed and steroid therapy was applied. All other evaluation work-up was negative and follow-up imaging was compatible with tumor. The neuropathologic study of the right temporal lesion revealed glioblastoma multiforme. Glioblastoma can crossover through the commissural white matter to the opposite cerebral hemisphere, most often through the corpus callosum. However, selective and bilateral invasion of the limbic system is rare and when it occurs it may mimic limbic encephalitis.

The brain as a distributed intelligent processing system: an EEG study.

BACKGROUND: Various neuroimaging studies, both structural and functional, have provided support for the proposal that a distributed brain network is likely to be the neural basis of intelligence. The theory of Distributed Intelligent Processing Systems (DIPS), first developed in the field of Artificial Intelligence, was proposed to adequately model distributed neural intelligent processing. In addition, the neural efficiency hypothesis suggests that individuals with higher intelligence display more focused cortical activation during cognitive performance, resulting in lower total brain activation when compared with individuals who have lower intelligence. This may be understood as a property of the DIPS. METHODOLOGY AND PRINCIPAL FINDINGS: In our study, a new EEG brain mapping technique, based on the neural efficiency hypothesis and the notion of the brain as a Distributed Intelligence Processing System, was used to investigate the correlations between IQ evaluated with WAIS (Wechsler Adult Intelligence Scale) and WISC (Wechsler Intelligence Scale for Children), and the brain activity associated with visual and verbal processing, in order to test the validity of a distributed neural basis for intelligence. CONCLUSION: The present results support these claims and the neural efficiency hypothesis.

Planktonic ciliates in a hypertrophic pond: functional role and importance.

Taxonomical composition and abundance of the planktonic ciliate assemblage in a Lake Tezozomoc, a hypertrophic pond located into an urban park in Mexico City, was investigated along the rainy season (May to October). The aims of the study were to know the main trophic roles and ecological significance of ciliates in a highly productive environment. A low number of taxa (27) and a wide abundance fluctuation (104-387 cil ml(-1)) were found. The most abundant species (up to 162 cil ml(-1)) was Halteria grandinella, an oligotrich ciliate that graze on bacteria and picoplankton, but also several big body sized species that feed on pico and nanoplankton were abundant. Sudden temporal changes in species dominance occurred. Ciliate biomass was very high and fluctuated widely (1.6-88 10(6) microm(3) ml(-1)) being dominated by the >50 microm size fraction that mainly included the pico and nanoplankton feeders. Ciliates are a very important component in the plankton of hypertrophic lakes and their main control factor seems to be the grazing by big-body size Daphnia species.

Neurodynamics of an election.

Variables influencing decision-making in real settings, as in the case of voting decisions, are uncontrollable and in many times even unknown to the experimenter. In this case, the experimenter has to study the intention to decide (vote) as close as possible in time to the moment of the real decision (election day). Here, we investigated the brain activity associated with the voting intention declared 1 week before the election day of the Brazilian Firearms Control Referendum about prohibiting the commerce of firearms. Two alliances arose in the Congress to run the campaigns for YES (for the prohibition of firearm commerce) and NO (against the prohibition of firearm commerce) voting. Time constraints imposed by the necessity of studying a reasonable number (here, 32) of voters during a very short time (5 days) made the EEG the tool of choice for recording the brain activity associated with voting decision. Recent fMRI and EEG studies have shown decision-making as a process due to the enrollment of defined neuronal networks. In this work, a special EEG technique is applied to study the topology of the voting decision-making networks and is compared to the results of standard ERP procedures. The results show that voting decision-making enrolled networks in charge of calculating the benefits and risks of the decision of prohibiting or allowing firearm commerce and that the topology of such networks was vote- (i.e., YES/NO-) sensitive.

Studying the satisfaction of patients on the outcome of an aesthetic dermatological filler treatment.

BACKGROUND: Many factors contribute to extend productive life in the modern world. Competition makes people worry about physical appearance, mostly in respect to facial and skin aging. This has motivated new developments in cosmetic dermatology and the need of evaluating patient satisfaction with the new proposed treatments. Poll questionnaire has been used for such evaluation, and the analysis of the electroencephalogram (EEG) mapping obtained while the patient answers the satisfaction questionnaire may render the results less subjective. OBJECTIVES: The purpose of this paper is to study the satisfaction of a group of 33 women (mean age, 44 years) treated with hyaluronic acid filling of nasolabial folding or lips, combining the EEG brain mapping and questionnaire techniques. METHODS: At the third month of evaluation, two networked personal computers were used for the EEG recording and for presenting the patient with a questionnaire about her well-being feeling; self-evaluation of her face; her satisfaction with the results of the aesthetic treatment; how the family, friends, and people at work evaluated the result of the treatment; and her decision to repeat the treatment and to recommend it to friends and family. RESULTS: Poll results showed that patients were feeling well and were satisfied with the results of the aesthetic treatment. Furthermore, the regression EEG mappings showed patients to be satisfied with their appearance and with the treatment involving similar brain areas. CONCLUSION: Patients decided to undergo the treatment because they were already considering it (54%) or because they were dissatisfied with their lips or nasolabial folding (52%). The fact that the treatment was free of charge solidified the decision. Patients consider themselves as good-looking and they wanted to preserve such a condition.

Mental retadation: a MRI study of 146 Brazilian children.

We report results of a magnetic ressonance imaging (MRI) study of 146 Brazilian children, whose intelligence quotient scored less than 70. 50% of MRI examinations did not exhibit any signal of structural lesion (N group), whereas a focal thinning at the junction of the body and splenium of the corpus callosum; ventricular asymmetry; periventricular leukomalacia; gliosis and arachnoid cysts were among the most frequent findings in the remaining of subjects (L group). Maternal stress and altered blood pressure were the most frequent findings in the pre-natal history of both N and L children. Familial antecedents of mental deficiency were reported in 30% of both groups, whereas familiar history of alcoholism was important in N group (60% in N versus 0% in L groups). Neuropsychomotor development was delayed in 80% of the children in both groups. Aggressiveness is the most frequent finding in the post-natal children history.

Mental retadation: a MRI study of 146 Brazilian children

Estudamos, através de ressonância magnética (RM), 146 crianças com quociente de inteligência menor que 70. 50% das RM não exibiram nenhum sinal de lesão (grupo N), enquanto adelgaçamento focal da junção do corpo e esplênio do corpo caloso, assimetria ventricular, leucomalácia periventricular, gliose e cisto aracnóide foram os achados mais freqüentes no restante das crianças (grupo L). Estresse materno e alteração da pressão arterial foram os achados mais freqüentes da história do pré-natal das crianças de ambos os grupos. Antecedentes familiares de deficiência mental apareceram em 30% de ambos os grupos. História de alcoolismo foi importante no grupo N. Atraso no desenvolvimento neuropsicomotor foi encontrado em 80% das crianças de ambos os grupos. Agressividade foi o achado mais freqüente na história pós-natal destas crianças.

Language plasticity revealed by electroencephalogram mapping.

Reasoning is the result of the computations made by intelligent systems, for instance those in the brain. It is not an abstract concept because calculations performed by computations are very concrete transactions among the different central processing unit components. Entropy measurements are proposed here to disclose the plasticity of the cerebral processing associated with language comprehension in video game playing. It is also assumed that entropy may be evaluated from the correlation coefficients obtained for the game event-related activity calculated for the different electroencephalogram derivations in the 10/20 system. The brain mapping derived from these entropy measurements clearly demonstrates the reallocation of speech functions to right brain areas when the classic left language circuits are damaged during prenatal life.

[Glioblastoma multiforme... with multifocal presentation]. / Glioblastoma multiforme ... com apresentação multifocal.

Glioblastoma multiforme is the most common malignant primary brain tumor in adults (+/- 40% of the Central Nervous System primary tumors). Representing only 2% of all oncologic processes, they are associated with a great deterioration of cerebral functions and a poor prognosis, facts that contribute to their great individual and social impact. The authors report a case of glioblastoma multiforme, with multifocal lesions "ab initio" and show the difficulty to make a correct diagnosis, even with the most modern imagiologic techniques. They also make a brief review of the literature.

Hallazgos histopatológicos, pronósticos del granuloma de células gigantes multinucleadas bucal / Histopathological, prognostic findings of the oral multinucleated giant cell granuloma

Se efectuó un estudio retrospectivo, comparativo, descriptivo, analítico, de las laminillas con diagnóstico de granuloma de células gigantes multinucleadas en cavidad bucal, de los casos diagnosticados en un periodo comprendido entre 1987 y 1994, que se presentaron en los hospitales regionales del IMSS, ISSSTE, SS y UBAC, en la escuela de odontología de la ciudad de León, Guanajuato. Se registraron 17 casos; 14 de primera vez y tres de recidiva. Para todas las laminillas se determinó la edad y sexo de los pacientes, el tamaño de las células, la distribución de las células en el estroma, la presencia de hemosiderina tanto de forma externa como interna a la célula, la vascularización, los eritrocitos extravasados, la presencia de hueso maduro, la presencia de hueso inmaduro, el número de mitosis y la cantidad de células gigantes multinucleadas. Se reporta por primera vez que la presencia de hueso inmaduro puede ser utilizada como un factor histopatológico de pronóstico para la recidiva de esta lesión en cavidad bucal