Neurobiology and clinical implications of lucid dreaming

Several lines of evidence converge to the idea that rapid eye movement sleep (REMS) is a good model to foster our understanding of psychosis. Both REMS and psychosis course with internally generated perceptions and lack of rational judgment, which is attributed to a hyperlimbic activity along with hypofrontality. Interestingly, some individuals can become aware of dreaming during REMS, a particular experience known as lucid dreaming (LD), whose neurobiological basis is still controversial. Since the frontal lobe plays a role in self-consciousness, working memory and attention, here we hypothesize that LD is associated with increased frontal activity during REMS. A possible way to test this hypothesis is to check whether transcranial magnetic or electric stimulation of the frontal region during REMS triggers LD. We further suggest that psychosis and LD are opposite phenomena: LD as a physiological awakening while dreaming due to frontal activity, and psychosis as a pathological intrusion of dream features during wake state due to hypofrontality. We further suggest that LD research may have three main clinical implications. First, LD could be important to the study of consciousness, including its pathologies and other altered states. Second, LD could be used as a therapy for recurrent nightmares, a common symptom of depression and post-traumatic stress disorder. Finally, LD may allow for motor imagery during dreaming with possible improvement of physical rehabilitation. In all, we believe that LD research may clarify multiple aspects of brain functioning in its physiological, altered and pathological states.

Arthropoda de solo em um ecossistema semi-árido da região neotropical: composição, variabilidade temporal e estratificação

Caatinga is an important laboratory for studies about arthropods adaptations and aclimatations because its precipitation is highly variable in time. We studied the effects of time variability over the composition of Arthropods in a caatinga area. The study was carried out at a preservation area on Almas Farm, São José dos Cordeiros, Paraíba. Samples were collected in two 100 m long parallel transects, separated for a 30 m distance, in a dense tree dominated caatinga area, between August 2007 and July 2008. Samples were collected in each transect every 10 m. Ten soil samples were taken from each transect, both at 0-5 cm (A) and 5-10 cm (B) depth, resulting in 40 samples each month. The Berlese funnel method was used for fauna extraction. We registered 26 orders and the arthropods density in the soil ranged from 3237 to 22774 individuals.m-2 from January 2007 to March 2008, respectively. There was no difference between layers A and B regarding orders abundance and richness. The groups recorded include groups with few records or that had no records in the Caatinga region yet as Pauropoda, Psocoptera, Thysanoptera, Protura and Araneae. Acari was the most abundant group, with 66,7% of the total number of individuals. Soil Arthropods presented a positive correlation with soil moisture, vegetal cover, precipitation and real evapotranspiration. Increases in fauna richness and abundance were registered in February, a month after the beginning of the rainy season. A periodic rain events in arid and semiarid ecosystems triggers physiological responses in edafic organisms, like arthropods. Edafic arthropods respond to time variability in the Caatinga biome. This fauna variation has to be considered in studies of this ecosystem, because the variation of Arthropods composition in soil can affect the dynamics of the food web through time

Práticas populares de cuidado à criança: o saber/fazer de cuidadoras

Popular practices correspond to the resources used by households, lay people and popular therapists, whose perception of knowledge is constructed in the everyday. In this context, the sick child can become vulnerable to be dependent on a family caregiver, who often decide to employ popular practices. Thus, the child care should be shared between carer and health professional. However, they know little about the resources that the family uses to detect a grievance in infant. Therefore, the present research aimed to analyse the use of popular practices by caregivers of children with zero to five years old. We conducted an exploratory and descriptive study with a qualitative approach, together with 15 caregivers of children who were treated at the Joint Unit Felipe Shrimp, located in Natal, Rio Grande do Norte, Brazil. To select the participants, they should be age and above 18 years; be caregivers of children up to five years of age; and reside in the area ascribed the Joint Unit Felipe Shrimp. The data collection took place between September and October 2013, through in depth interview. This step was preceded by the approval of the Health Department of the city of Natal; the direction of the Joint Unit Felipe Shrimp; as well as, the Committee on Ethics in Research from the Federal University of Rio Grande do Norte with Certificate of Presentation and Consideration Ethics, No 15467013.8.0000.5537. Furthermore, the interviewees formally authorized their participation in the research by signing the consent form. The data were treated according to the technique of content analysis in the form of thematic analysis according to Bardin. This process, four categories emerged: "Types of popular practices used in the care of the child"; "Source of information of popular practices"; "Results obtained with popular practices"; "Factors that hinder the adoption of common practices." The results showed the use of popular practices by caregivers in the case of illness to children such as the homemade preparations with medicinal plants and folk healers. The family environment was referenced as the main learning space and spread of popular practices, which are influenced by cultural relations present in this context. As to the results obtained with popular features, the caregivers said to be satisfactory, and this triggers a feeling of confidence and acceptability of such measures. It is concluded that the use of popular practices in child care persists in everyday most of the participants, despite the hegemony of allopathic therapy. The caregivers stated that such practices are effective and easy to obtain, being secured in context by popular culture. In addition, health professionals, especially nurses, were seldom mentioned by the caregivers as to the information concerning popular resources used by them, which suggests the weakness in dialogic process of negotiating practices between both of them

Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional

Several research lines show that sleep favors memory consolidation and learning. It has been proposed that the cognitive role of sleep is derived from a global scaling of synaptic weights, able to homeostatically restore the ability to learn new things, erasing memories overnight. This phenomenon is typical of slow-wave sleep (SWS) and characterized by non-Hebbian mechanisms, i.e., mechanisms independent of synchronous neuronal activity. Another view holds that sleep also triggers the specific enhancement of synaptic connections, carrying out the embossing of certain mnemonic traces within a lattice of synaptic weights rescaled each night. Such an embossing is understood as the combination of Hebbian and non-Hebbian mechanisms, capable of increasing and decreasing respectively the synaptic weights in complementary circuits, leading to selective memory improvement and a restructuring of synaptic configuration (SC) that can be crucial for the generation of new behaviors ( insights ). The empirical findings indicate that initiation of Hebbian plasticity during sleep occurs in the transition of the SWS to the stage of rapid eye movement (REM), possibly due to the significant differences between the firing rates regimes of the stages and the up-regulation of factors involved in longterm synaptic plasticity. In this study the theories of homeostasis and embossing were compared using an artificial neural network (ANN) fed with action potentials recorded in the hippocampus of rats during the sleep-wake cycle. In the simulation in which the ANN did not apply the long-term plasticity mechanisms during sleep (SWS-transition REM), the synaptic weights distribution was re-scaled inexorably, for its mean value proportional to the input firing rate, erasing the synaptic weights pattern that had been established initially. In contrast, when the long-term plasticity is modeled during the transition SWSREM, an increase of synaptic weights were observed in the range of initial/low values, redistributing effectively the weights in a way to reinforce a subset of synapses over time. The results suggest that a positive regulation coming from the long-term plasticity can completely change the role of sleep: its absence leads to forgetting; its presence leads to a positive mnemonic change

Geologia, Geocronologia, Geoquímica e Petrogênese das Rochas Ígneas Cretácicas da Província Magmática do Cabo e suas Relações com as Unidades Sedimentares da Bacia de Pernambuco (NE do Brasil)

The area studied forms a thin NNE-directed belt situated south of Recife town (Pernambuco state), northeastern Brazil. Geologically, it comprises the Pernambuco Basin (PB), which is limited by the Pernambuco Lineament to the north, the Maragogi high to the south and the Pernambuco Alagoas massif to the west, all of them with Precambrian age. This thesis reports the results obtained for the Cabo Magmatic Province (CMP), aiming the characterization of the geology, stratigraphy, geochronology, geochemistry and petrogenesis of the Cretaceous igneous rocks presented in the PB. The PB is composed of the Cabo Formation (rift phase) at the base (polymictic conglomerates, sandstones, shales), an intermediate unit, the Estiva Formation (marbles and argillites), and, at the top, the Algodoais Formation (monomictic conglomerates, sandstones, shales). The CMP is represented by trachytes, rhyolites, pyroclastics (ignimbrites), basalts / trachy-andesites, monzonites and alkali-feldspar granite, which occur as dykes, flows, sills, laccoliths and plugs. Field observations and well descriptions show that the majority of the magmatic rocks have intrusive contacts with the Cabo Formation, although some occurrences are also suggestive of synchronism between volcanism and siliciclastic sedimentation. 40Ar/39Ar and zircon fission tracks for the magmatic rocks indicate an average age of 102 r 1 Ma for the CMP. This age represents an expressive event in the province and is detected in all igneous dated materials. It is considered as a minimum age (Albian) for the magmatic episode and the peak of the rift phase in the PB. The 40Ar/39Ar dates are about 10-14 Ma younger than published palynologic ages for this basin. Geochemically, the CMP may be divided in two major groups; i) a transitional to alkaline suite, constituted by basalts to trachy-andesites (types with fine-grained textures and phenocrysts of sanidine and plagioclase), trachytes (porphyrytic texture, with phenocrysts of sanidine and plagioclase) and monzonites; ii) a alkaline suite, highly fractionated, acidic volcano-plutonic association, formed by four subtypes (pyroclastic flows ignimbrites, fine-to medium-grained rhyolites, a high level granite, and later rhyolites). These four types are distinguished essentially by field aspects and petrographic and textural features. Compatible versus incompatible trace element concentrations and geochemical modeling based on both major and trace elements suggest the evolution through low pressure fractional crystallization for trachytes and other acidic rocks, whereas basalts / trachy-andesites and monzonites evolved by partial melting from a mantle source. Sr and Nd isotopes reveal two distinct sources for the rocks of the CMP. Concerning the acidic ones, the high initial Sr ratios (ISr = 0.7064-1.2295) and the negative HNd (-0.43 to -3.67) indicate a crustal source with mesoproterozoic model ages (TDM from 0.92 to 1.04 Ga). On the other hand, the basic to intermediate rocks have low ISr (0.7031-0.7042) and positive HNd (+1.28 to +1.98), which requires the depleted mantle as the most probable source; their model ages are in the range 0.61-0.66 Ga. However, the light rare earth enrichment of these rocks and partial melting modeling point to an incompatible-enriched lherzolitic mantle with very low quantity of garnet (1-3%). This apparent difference between geochemical and Nd isotopes may be resolved by assuming that the metasomatizing agent did not obliterate the original isotopic characteristics of the magmas. A 2 to 5% partial melting of this mantle at approximately 14 kbar and 1269oC account very well the basalts and trachy-andesites studied. By using these pressure and temperatures estimates for the generation of the basaltic to trachy-andesitic magma, it is determined a lithospheric stretching (E) of 2.5. This E value is an appropriated estimate for the sub-crustal stretching (astenospheric or the base of the lithosphere?) region under the Pernambuco Basin, the crustal stretching probably being lower. The integration of all data obtained in this thesis permits to interpret the magmatic evolution of the PB as follows; 1st) the partial melting of a garnet-bearing lherzolite generates incompatible-enriched basaltic, trachy-andesitic and monzonitic magmas; 2nd) the underplating of these basaltic magmas at the base of the continental crust triggers the partial melting of this crust, and thus originating the acidic magmas; 3rd) concomitantly with the previous stage, trachytic magmas were produced by fractionation from a monzonitic to trachy-andesitic liquid; 4th) the emplacement of the several magmas in superficial (e.g. flows) or sub-superficial (e.g. dykes, sills, domes, laccoliths) depths was almost synchronically, at about 102 r 1 Ma, and usually crosscutting the sedimentary rocks of the Cabo Formation. The presence of garnet in the lherzolitic mantle does not agree with pressures of about 14 kbar for the generation of the basaltic magma, as calculated based on chemical parameters. This can be resolved by admitting the astenospheric uplifting under the rift, which would place deep and hot material (mantle plume?) at sub-crustal depths. The generation of the magmas and their subsequent emplacement would be coupled with the crustal rifting of the PB, the border (NNE-SSW directed) and transfer (NW-SE directed) faults serving as conduits for the magma emplacement. Based on the E parameter and the integration of 40Ar/39Ar and palynologic data it is interpreted a maximum duration of 10-14 Ma for the rift phase (Cabo Formation clastic sedimentation and basic to acidic magmatism) of the PB

Imaginários da morte: poética das imagens em cemitérios brasileiros

The thesis presented is committed to a poetic reading that results in the creation of meaning and images of the death from the various cultural practices and symbolic representations exposed in urban cemeteries in some Brazilian cities, aiming to give visibility to new understandings about the imaginary of the in the contemporary scene. Death, therefore, will be seen as a imagining condition of anthroposwhen starts itself from the prerogative of the human consciousness of death (MORIN, 1970), in other words, this awareness that man has he will die and that triggers reflections about their existence allows the emergence of a number of practices such as: mourning, funeral rituals and the creation of several impregnated representations of human emotions emerged from the death facing the man and present, in a more evident form in cemeterial spaces. For this, it focuses on the conflictuous dimension that man establishes with death, because the cultural practices and symbolic representations observed in the research field are the result of this conflict and allow the expansion of the senses about this issue, to the extent that these are coated with a fantastic aura, mystical, secret, spooky, fearful, religious, building a complex imagination. The general plan of this study is to discuss and create, from a phenomenology of imagination and materials / dynamics imagination, as well as along the lines treated by Gaston Bachelard, images of death, from a field experience in cemeteries in Brazil. For this, it is assumed, to observe the cultural practices and symbolic representations in these spaces, a posture able to make the experience into the search field a moment of symbolic exchanges and creation. Thus, it was used observation, conversations with visitors and employees of the cemeteries and the capture of photographic records. The data produced as a fragment of a conversation, a tearful outburst about the loss of a relative, a melancholic epitaph, a flower on the grave or a cry captured by photography were seen as detonators of meanings and a poetic of the imagination.

Imaginários da morte: poética das imagens em cemitérios brasileiros

The thesis presented is committed to a poetic reading that results in the creation of meaning and images of the death from the various cultural practices and symbolic representations exposed in urban cemeteries in some Brazilian cities, aiming to give visibility to new understandings about the imaginary of the in the contemporary scene. Death, therefore, will be seen as a imagining condition of anthroposwhen starts itself from the prerogative of the human consciousness of death (MORIN, 1970), in other words, this awareness that man has he will die and that triggers reflections about their existence allows the emergence of a number of practices such as: mourning, funeral rituals and the creation of several impregnated representations of human emotions emerged from the death facing the man and present, in a more evident form in cemeterial spaces. For this, it focuses on the conflictuous dimension that man establishes with death, because the cultural practices and symbolic representations observed in the research field are the result of this conflict and allow the expansion of the senses about this issue, to the extent that these are coated with a fantastic aura, mystical, secret, spooky, fearful, religious, building a complex imagination. The general plan of this study is to discuss and create, from a phenomenology of imagination and materials / dynamics imagination, as well as along the lines treated by Gaston Bachelard, images of death, from a field experience in cemeteries in Brazil. For this, it is assumed, to observe the cultural practices and symbolic representations in these spaces, a posture able to make the experience into the search field a moment of symbolic exchanges and creation. Thus, it was used observation, conversations with visitors and employees of the cemeteries and the capture of photographic records. The data produced as a fragment of a conversation, a tearful outburst about the loss of a relative, a melancholic epitaph, a flower on the grave or a cry captured by photography were seen as detonators of meanings and a poetic of the imagination.