976 resultados para separação


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pouco se conhece sobre os epítopos derivados de promastigotas metacíclicos de Leishmania que são importantes para a regulação ou destruição do parasita, como alvos de ação imunológica no hospedeiro vertebrado. Neste estudo, nós investigamos um método alternativo para obter promastigotas metacíclicos de Leishmania major, pela avaliação do curso da infecção e reação de hipersensibilidade do tipo retardado (HTR) em hospedeiros resistentes e susceptíveis. Promastigotas não-infectantes (procíclicos) de L. major, recentemente isolados de amastigotas, foram selecionados pela adesão a colunas de lã de vidro negativamente carregadas, enquanto que promastigotas metacíclicos não se aderem à coluna e podem ser recuperados com facilidade. Condições ótimas de cromatografia foram validadas por análise estatística. O rendimento médio de parasitas obtidos após separação em colunas de lã de vidro e a viabilidade dos promastigotas foram estimados por microscopia óptica. Os promastigotas metacíclicos tiveram um rendimento médio de 43,5% a 57,5%. Camundongos BALB/c (susceptíveis) e camundongos C57BL/6 (resistentes) apresentaram padrões distintos de lesões cutâneas, os primeiros com lesões mais agressivas, induzidas por promastigotas metacíclicos. As respostas à reação de HTR foram maiores nos grupos de camundongos C57BL/6, submetidos à infecção com promastigotas metacíclicos. Estes resultados indicam que o novo método poderia ser integrado aos protocolos existentes para estudar a metaciclogênese de parasitas do gênero Leishmania in vivo.

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The mirror has always been related to different symbols, usually connected to self-knowledge and truth. This is due to the fact that this object shows whoever looks oneself in it an image as close to reality as it is possible. On the other hand, the mirror is also associated to mysticism and to the supernatural for it can magically duplicate one who looks into it. This ambiguous characteristic turns the mirror into an element that is fantastic in itself and places it in the central position of our discussion. Therefore, in this study, we analyze the texts In a Glass Darkly, by Agatha Christie, The Oval Portrait, by Edgar Allan Poe, and The Picture of Dorian Gray, by Oscar Wilde, giving special attention to the study of the images and artificial representations of men: the mirror, as an ephemeral representation; and the portrait, as an attempt to eternize an ephemeral image. We also discuss themes such as jealousy, the double, and death in the several forms in which it appears in the texts: suicides, homicides, attempted murders, death in life (mourning, separation, and developmental phases) all of which are, somehow, related to the specular representations. The narrative resource of using a mirror to introduce the supernatural event, along with the theme of death in all the narratives we have studied, and the difficulty to place these texts within the pre-established genres led us to categorize them as being part of a hybrid genre that presents characteristics both of the fantastic and of the detective story which we have named fantastic-detective story

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Esta investigación toma como tema la asignatura Lengua Portuguesa en el contexto de la enseñanza media integrada a la educación profesional, implementado en el año de 2005, en el Instituto Federal de Educação, ciência y tecnología del Rio Grande do Norte. En el ámbito general, objetiva analizar las voces reveladas en posicionamientos sobre la asignatura Lengua Portuguesa en este contexto. En este estudio, el uso del adjetivo integrado es comprendido como revelador de una formación escolar no basada en investigaciones dicotómicas, sobre todo en aquellas que evidencian una separación entre el conocimiento y el ejercicio profesional. Se buscó aporte teórico en los debates del área de educación, sobre formación integrada, en la visión de contemporaneidad de Bauman y en la concepción de lenguaje de M. Bakhtin. El corpus se compone de material empírico de la naturaleza cuantitativa y cualitativa, obtenido por medio de aplicación de cuestionarios con alumnos y profesionales, además del análisis documental de los PCNEM y de las OCEM, a lo que se refiere a asignatura Lengua Portuguesa. El direccionamiento metodológico es guiado por el paradigma cualitativo inserido en una perspectiva socio-histórica y eligió como categoría de análisis el concepto de voces sociales. Los resultados indican que la asignatura Lengua Portuguesa, en la perspectiva de integración con el mundo del trabajo, adquiere, en mayor o menor grado, en lo observado en los documentos oficiales y en los posicionamientos de alumnos y profesionales de la enseñanza media integrada a la educación profesional del IFRN, un perfil cuya esencia, lejos de asumir características de una enseñanza instrumental reductora, requiere una concepción de lenguaje que esté en sintonía con el mundo del trabajo de la sociedad contemporánea, una sociedad cada vez más abierta a la pluralidad de opiniones y a la ambivalencia de sentidos

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Conselho Nacional de Desenvolvimento Científico e Tecnológico

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The effect of confinement on the magnetic structure of vortices of dipolar coupled ferromagnetic nanoelements is an issue of current interest, not only for academic reasons, but also for the potential impact in a number of promising applications. Most applications, such as nano-oscillators for wireless data transmission, benefit from the possibility of tailoring the vortex core magnetic pattern. We report a theoretical study of vortex nucleation in pairs of coaxial iron and Permalloy cylinders, with diameters ranging from 21nm to 150nm, and 12nm and 21nm thicknesses, separated by a non-magnetic layer. 12nm thick iron and Permalloy isolated (single) cylinders do not hold a vortex, and 21nm isolated cylinders hold a vortex. Our results indicate that one may tailor the magnetic structure of the vortices, and the relative chirality, by selecting the thickness of the non-magnetic spacer and the values of the cylinders diameters and thicknesses. Also, the dipolar interaction may induce vortex formation in pairs of 12nm thick nanocylinders and inhibit the formation of vortices in pairs of 21nm thick nanocylinders. These new phases are formed according to the value of the distance between the cylinderes. Furthermore, we show that the preparation route may control relative chirality and polarity of the vortex pair. For instance: by saturating a pair of Fe 81nm diameter, 21nm thickness cylinders, along the crystalline anisotropy direction, a pair of 36nm core diameter vortices, with same chirality and polarity is prepared. By saturating along the perpendicular direction, one prepares a 30nm diameter core vortex pair, with opposite chirality and opposite polarity. We also present a theoretical discussion of the impact of vortices on the thermal hysteresis of a pair of interface biased elliptical iron nanoelements, separated by an ultrathin nonmagnetic insulating layer. We have found that iron nanoelements exchange coupled to a noncompensated NiO substrate, display thermal hysteresis at room temperature, well below the iron Curie temperature. The thermal hysteresis consists in different sequences of magnetic states in the heating and cooling branches of a thermal loop, and originates in the thermal reduction of the interface field, and on the rearrangements of the magnetic structure at high temperatures, 5 produce by the strong dipolar coupling. The width of the thermal hysteresis varies from 500 K to 100 K for lateral dimensions of 125 nm x 65 nm and 145 nm x 65 nm. We focus on the thermal effects on two particular states: the antiparallel state, which has, at low temperatures, the interface biased nanoelement with the magnetization aligned with the interface field and the second nanoelement aligned opposite to the interface field; and in the parallel state, which has both nanoelements with the magnetization aligned with the interface field at low temperatures. We show that the dipolar interaction leads to enhanced thermal stability of the antiparallel state, and reduces the thermal stability of the parallel state. These states are the key phases in the application of pairs of ferromagnetic nanoelements, separated by a thin insulating layer, for tunneling magnetic memory cells. We have found that for a pair of 125nm x 65nm nanoelements, separated by 1.1nm, and low temperature interface field strength of 5.88kOe, the low temperature state (T = 100K) consists of a pair of nearly parallel buckle-states. This low temperature phase is kept with minor changes up to T= 249 K when the magnetization is reduced to 50% of the low temperature value due to nucleation of a vortex centered around the middle of the free surface nanoelement. By further increasing the temperature, there is another small change in the magnetization due to vortex motion. Apart from minor changes in the vortex position, the high temperature vortex state remains stable, in the cooling branch, down to low temperatures. We note that wide loop thermal hysteresis may pose limits on the design of tunneling magnetic memory cells

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Este estudo teve por objetivo: (a) caracterizar uma amostra de mães e filhos, em famílias separadas, quanto às suas habilidades sociais; (b) investigar relações entre as habilidades sociais educativas das mães e o comportamento das crianças; e (c) comparar grupo clínico e não-clínico quanto ao repertório comportamental. Participaram da pesquisa 43 mães de crianças de ambos os sexos, com idade entre quatro e seis anos. As participantes responderam a um Questionário Sociodemográfico, Roteiro de Entrevista de Habilidades Sociais Educativas Parentais, Child Behavior Checklist - CBCL, Questionário de Respostas Socialmente Habilidosas e Escala Infantil A2 de Rutter. Para análise de dados, empregaram-se os testes Spearman e Mann-Whitney. Os resultados mostraram que habilidades sociais educativas das mães estiveram relacionadas a habilidades sociais das crianças, enquanto práticas negativas foram relacionadas a problemas de comportamento. Discutem-se como as habilidades sociais maternas podem influenciar o comportamento dos filhos em famílias separadas.

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The caffeine is a mild psychostimulant that has positive cognitive effects at low doses, while promotes detrimental effects on these processes at higher doses. The episodic-like memory can be evaluated in rodents through hippocampus-dependent tasks. The dentate gyrus is a hippocampal subregion in which neurogenesis occurs in adults, and it is believed that this process is related to the function of patterns separation, such as the identification of spatial and temporal patterns when discriminating events. Furthermore, neurogenesis is influenced spatial and contextual learning tasks. Our goal was to evaluate the performance of male Wistar rats in episodic-like tasks after acute or chronic caffeine treatment (15mg/kg or 30mg/kg). Moreover, we assessed the chronic effect of the caffeine treatment, as well as the influence of the hippocampus-dependent learning tasks, on the survival of new-born neurons at the beginning of treatment. For this purpose, we used BrdU to label the new cells generated in the dentate gyrus. Regarding the acute treatment, we found that the saline group presented a tendency to have better spatial and temporal discrimination than caffeine groups. The chronic caffeine group 15 mg/kg (low dose) showed the best discrimination of the temporal aspect of episodic-like memory, whereas the chronic caffeine group 30mg/kg (high dose) was able to discriminate temporal order, only in a condition of greater difficulty. Assessment of neurogenesis using immunohistochemistry for evaluating survival of new-born neurons generated in the dentate gyrus revealed no difference among groups of chronic treatment. Thus, the positive mnemonic effects of the chronic caffeine treatment were not related to neuronal survival. However, another plastic mechanism could explain the positive mnemonic effect, given that there was no improvement in the acute caffeine groups

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Desde os descobrimentos pioneiros de Hubel e Wiesel acumulou-se uma vasta literatura descrevendo as respostas neuronais do córtex visual primário (V1) a diferentes estímulos visuais. Estes estímulos consistem principalmente em barras em movimento, pontos ou grades, que são úteis para explorar as respostas dentro do campo receptivo clássico (CRF do inglês classical receptive field) a características básicas dos estímulos visuais como a orientação, direção de movimento, contraste, entre outras. Entretanto, nas últimas duas décadas, tornou-se cada vez mais evidente que a atividade de neurônios em V1 pode ser modulada por estímulos fora do CRF. Desta forma, áreas visuais primárias poderiam estar envolvidas em funções visuais mais complexas como, por exemplo, a separação de um objeto ou figura do seu fundo (segregação figura-fundo) e assume-se que as conexões intrínsecas de longo alcance em V1, assim como as conexões de áreas visuais superiores, estão ativamente envolvidas neste processo. Sua possível função foi inferida a partir da análise das variações das respostas induzidas por um estímulo localizado fora do CRF de neurônios individuais. Mesmo sendo muito provável que estas conexões tenham também um impacto tanto na atividade conjunta de neurônios envolvidos no processamento da figura quanto no potencial de campo, estas questões permanecem pouco estudadas. Visando examinar a modulação do contexto visual nessas atividades, coletamos potenciais de ação e potenciais de campo em paralelo de até 48 eletrodos implantados na área visual primária de gatos anestesiados. Estimulamos com grades compostas e cenas naturais, focando-nos na atividade de neurônios cujo CRF estava situado na figura. Da mesma forma, visando examinar a influência das conexões laterais, o sinal proveniente da área visual isotópica e contralateral foi removido através da desativação reversível por resfriamento. Fizemos isso devido a: i) as conexões laterais intrínsecas não podem ser facilmente manipuladas sem afetar diretamente os sinais que estão sendo medidos, ii) as conexões inter-hemisféricas compartilham as principais características anatômicas com a rede lateral intrínseca e podem ser vistas como uma continuação funcional das mesmas entre os dois hemisférios e iii) o resfriamento desativa as conexões de forma causal e reversível, silenciando temporariamente seu sinal, permitindo conclusões diretas a respeito da sua contribuição. Nossos resultados demonstram que o mecanismo de segmentação figurafundo se reflete nas taxas de disparo de neurônios individuais, assim como na potência do potencial de campo e na relação entre sua fase e os padrões de disparo produzidos pela população. Além disso, as conexões laterais inter-hemisféricas modulam estas variáveis dependendo da estimulação feita fora do CRF. Observamos também uma influência deste circuito lateral na coerência entre potenciais de campo entre eletrodos distantes. Em conclusão, nossos resultados dão suporte à ideia de um mecanismo complexo de segmentação figura-fundo atuando desde as áreas visuais primárias em diferentes escalas de frequência. Esse mecanismo parece envolver grupos de neurônios ativos sincronicamente e dependentes da fase do potencial de campo. Nossos resultados também são compatíveis com a hipótese que conexões laterais de longo alcance também fazem parte deste mecanismo

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The present study investigated the reproductive dynamics and parasitism of four species of marine fishes: serra Spanish mackerel, Scomberomorus brasiliensis, Atlantic leatherjacks, Oligoplites saurus and O. palometa,, and Atlantic bumper, C. chrysurus, during the period of August, 2005 to July, 2007, in the coastal waters of Southwest Atlantic Ocean, Brazil. The collected fish samples were measured, weighed, dissected, the gonads were weighed and examined to separate the sex. The gonadosomatic index (GSI), fecundity, type of spawning, the breeding season, the macro and microscopic characterization of the gonads were determined. The ectoparasites from the branchial chambers and bucal cavity of the fish were collected, measured, weighed and identified. The sex ratio of the study fish species were approximately 1M:1F, however, there was a predominance of males of O. palometa (3M:2F). The GSI of fishes varied according to their reproductive cycle and the stage of gonadal maturation. The highest values of GSI and the spawning period coincided with the rainy period of the region. The females presented total spawning and the fecundity was positively correlated with the weight of the ovary and the body. Four stages of development of the gonads immature, maturing, mature and spent were identified macroscopically and histological analyses of ovaries revealed the different phases of oocyte development. Three species of isopod parasites were identified in the study fishes: Livoneca redmmanni, Rocinela signata and Cimothoa spinipalpa. The first two species occurred in the branchial cavities of C. chrysurus and S. brasiliensis. The isopod C.spinipalpa (a new species) was registered for the first time in the bucal cavity of O. saurus and O. palometa. The parasitic isopods preferred the branchial chambers and the bucal cavity of the host fishes as these were protected microhabitats. The isopods parasitized the immature, maturing and mature fishes. The prevalence of infection of isopods in the hosts varied from 16 to 21%, though in O. palometa it was 60%. In the rainy period the highest isopod parasitic occurrence was registered, however, this did not prejudice the normal reproductive cycle of the host fish.

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Regarding the growing number of human beings with physical and mental pathologies associated to different stressor agents, attempts are being made to validate animal models with a close phylogenetic resemblance to man, to study stress response. Callithrix jacchus has been widely used in biomedical research, including on stress, but there is scarce information in the literature about how individual and social factors modulate stressor response in this species. This study uses 4 approaches to investigate the response of male and female adult C. jacchus, under situations of stress, and in the first we show evidence of the importance of this animal as an experimental model in research involving the hypothalamus-pituitary-adrenal axis. And we investigate if sex and baseline cortisol levels modulate the behavioral and hormonal response to separation. In two additional approaches investigate if type of social support (co-specific parent or non-parent) and social rank interfere in behavioral and hormonal when the animal are exposure to a new environment, paired with a co-specific (F2), exposure of the animal to a new environment, isolated (F3) or during reunion (F4). Finally, we also investigated the androgen levels in the males, with a focus on the challenge hypothesis, referring to environmental responsiveness and male-male exposure to relatives and non-relatives of C. jacchus. It was observed that: (1) the baseline cortisol of the animal is predictive of cortisol reactivity at separation; (2) males and females do not show dimorphism in the response of cortisol to stressors, although the females have higher baseline levels of this hormone and exhibit higher frequencies of anxiety-related behaviors; (3) only social support provided by relatives proved to be effective in buffering the cortisol response. In behavioral terms this response was dimorphic, showing that only the male dyads displayed an attenuated response to stress; (4) the males showed differences in cortisol levels as a function of social rank and study phases, whereas in the females no such alterations were observed. The males with indefinite dominance hierarchy (IDH) had reduced cortisol in F2 and F4, while the IDH females showed an increase in F3 and F4; (5) the males of relative and non-relative dyads did not exhibit variations in androgen levels as a function of a new environment. These results, taken together, (a) corroborate the use of C. jacchus as a good animal model for stress-related studies, given that they exhibit similar behavioral and physiological alterations to those of human beings in response to stressor agents; (b) point to the importance of considering individual and social modulating factors during experiments with stressors; (c) provide more reliable comparison parameters in studies where these primates are used as animal models, and (d) show that androgens vary as a function of genetic proximity (relative or non-relative) when the animals are faced with physical and social environmental challenges, thus providing important information for studying the challenge hypothesis in this species

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Episodic memory refers to the recollection of what, where and when a specific event occurred. Hippocampus is a key structure in this type of memory. Computational models suggest that the dentate gyrus (DG) and the CA3 hippocampal subregions are involved in pattern separation and the rapid acquisition of episodic memories, while CA1 is involved in memory consolidation. However there are few studies with animal models that access simultaneously the aspects ‗what-where-when . Recently, an object recognition episodic-like memory task in rodents was proposed. This task consists of two sample trials and a test phase. In sample trial one, the rat is exposed to four copies of an object. In sample trial two, one hour later, the rat is exposed to four copies of a different object. In the test phase, 1 h later, two copies of each of the objects previously used are presented. One copy of the object used in sample trial one is located in a different place, and therefore it is expected to be the most explored object.However, the short retention delay of the task narrows its applications. This study verifies if this task can be evoked after 24h and whether the pharmacological inactivation of the DG/CA3 and CA1 subregions could differentially impair the acquisition of the task described. Validation of the task with a longer interval (24h) was accomplished (animals showed spatiotemporal object discrimination and scopolamine (1 mg/kg, ip) injected pos-training impaired performance). Afterwards, the GABA agonist muscimol, (0,250 μg/μl; volume = 0,5 μl) or saline were injected in the hippocampal subregions fifteen minutes before training. Pre-training inactivation of the DG/CA3 subregions impaired the spatial discrimination of the objects (‗where ), while the temporal discrimination (‗when ) was preserved. Rats treated with muscimol in the CA1 subregion explored all the objects equally well, irrespective of place or presentation time. Our results corroborate the computational models that postulate a role for DG/CA3 in spatial pattern separation, and a role for CA1 in the consolidation process of different mnemonic episodes

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The new Evolutionary Psychology (E. P.) paradigm has been trying to understand how the human beings make their decisions over time regarding the most diverse variables, always bearing in mind that such a cognitive process is due to a complex natural selection process that occurred millions of years ago. One of the main topics discussed by this new paradigm is the issue of parental investment, i.e., the care the parents provide to an offspring at the expense of the investment into a new one. The present work sought to integrate these two topics, trying to understand how some variables modulate the process of decision making in a sample of the city of Natal, Rio Grande do Norte state. It was investigated the hypothesis that the presence of both parents, along the individual development, could signal a more favorable environment, providing clues to the individual that he could assume a competitive position at the socio-biological market. His decisions, therefore, could be guided by long-term investments with aims to obtain more robust rewards. On the contrary, those who has suffered for some moment the absence of one the parents could develop theirselves in a not so competitive way, starting to choose immediate benefits - but lesser ones -, since the future would be less predictable due to their worse development conditions. This study involved 152 individuals from three higher education institutions, one of them being public and the others being private ones. In the results found, there was no difference between children of coupled parents and children of deceased or divorced parents concerning discount rates. The levels of hopelessness did not affect the discount rates of children of single parents when compared to children of coupled parents. Not having one of the parents because of divorce made the child to tend to present lower scores in the domain of social relations of WHOQOL - Bref, whilst the absence of the father by death made the scores lower in the domain of environment. The results indicate that loosing one of the parents along the development influences the individual's quality of life perception, but the measurement method of future discounting rates by means of financial choices is not sensitive to this variation

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Espécies de artrópodos entomófagos foram coletadas e identificadas nos genótipos sorgo AF-28, IAC-83/75-5-1-6, TX-2536, BR-300, IPA-201 e SAR, no Município de Selvíria, MS. Foram conduzidos três experimentos em campo, com os genótipos sendo semeados em 03/1988, 10/1988 e 02/1989, respectivamente. Para contagem dos artrópodos entomófagos, no início do florescimento foram marcadas 560 panículas por genótipo. Após esse momento, diariamente e durante 14 dias seguidos, foram coletadas 40 panículas por genótipo (10 por parcela). Nas coletas foram utilizados sacos plásticos com 10 litros de capacidade para envolver as panículas e capturar os artrópodos presentes. As panículas coletadas foram levadas para o Laboratório de Entomologia da Faculdade de Engenharia/UNESP, Campus de Ilha Solteira, SP, para separação, contagem e identificação dos artrópodos. Nas panículas provenientes da semeadura da seca coletou-se, em média, maior número de artrópodos entomófagos em relação à semeadura das águas. Dos artrópodos entomófagos coletados, as aranhas apresentaram maior número de espécies e, desses, a tecelã Alpaida veniliae (Keys.), a aranha corredora noturna Cheiracanthium inclusum (Blackwall), e a caçadora de emboscada, Misumenops pallidus (Keys.), foram as mais abundantes. O genótipo de sorgo IPA-201 comportou-se como o mais atrativo ao percevejo Orius sp. e à tesourinha Doru lineare (Eschs.), enquanto que o IAC-83/75-5-1-6 foi medianamente atrativo a D. lineare. As aranhas foram coletadas em maior número nos genótipos BR-300 e SART.

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The tales of children's literature, in their plots, mark existential dilemmas belonging in human‟s lives, such as death, situations of separation, loss, abandonment, fear, challenges, achievements and other elements that make them suitable material to assist children in their developmental process. Such elements, present in children‟s storybooks, are close to the experiences lived by the children in the context of hospitalization in a special manner. With that said this study focus on the understanding of the therapeutic possibilities of the tales of children's literature in the care of hospitalized children in Pediatric Intensive Care Units (UTIPED) based on the Heidegger's concept of Care and adopting the Phenomenology as the method. The UTIPED of a state public hospital located in the municipality of Natal/RN was elected as the study site and four hospitalized children aged between six and nine years, all males, presenting different clinical conditions were selected to participate in the study following age and clinical conditions as the selective criteria. The procedure of corpus construction included eight individual sessions of storytelling accompanied by the use of ludic resources. The phenomenological understanding about the therapeutic possibilities of tales was structured under three main elements: (1) the ludic axis; (2) the reflective axis; and (3) the affective axis. The appropriateness of the proposed therapy in the context of the UTIPED and the potential of the tales as a protection factor to the child was evident. The storytelling activity framed a scenario of care unusual in the context of intensive care units, establishing a symbolic space for children‟s expression. Therefore, this study indicates this therapeutic proposal for children‟s care in the UTIPED that considers their evolutionary stage, their clinical conditions at the time and especially their emotional needs during their immersion in a diverse and foreign environment which is filled with potentially harmful elements to their full development.