Critical perspectives on rehabilitation education, practice and process: northern Honduras case study.

BACKGROUND: Rehabilitation services are an integral part of patient care, but in many developing countries, they are not prioritized and either unavailable or easily accessible to those who need them. Although the need for rehabilitation services is increasing in Honduras, rehabilitation workers are not included in the health care model that guides the care provided to communities, particularly in rural and remote areas. To understand the need for providing impactful rehabilitation services in disadvantaged communities, we explored the education and perception of the community relating to rehabilitation, investigated training available for rehabilitation workers, and examined the rehabilitation processes and practices in Northern Honduras from stakeholders' experiences. METHODS: We utilized a qualitative descriptive and interpretive approach grounded in case study methodology to understand rehabilitation education, process, and practice in Northern Honduras. Three rehabilitation centres were purposefully selected as the cases, and participants consisted of rehabilitation workers and managers from these centres. We collected data via interviews and focus group sessions. We analyzed the data via thematic analysis using NVivo version 12. RESULTS: In Northern Honduras, rehabilitation workers' limited training and continuing education, along with awareness about rehabilitation by community members and other health providers influence rehabilitation care. Although policies and initiatives to support people with disabilities and the broader community in need of rehabilitation exist, most policies are not applied in practice. The sustainability of rehabilitation services, which is rooted in charity, is challenged by the small range of funding opportunities strongly affecting rehabilitation care processes and clinical practices. The lack of trust and awareness from the medical profession towards rehabilitation workers sets a major barrier to referrals, interdisciplinary work, and quality of life for individuals in need of rehabilitation. CONCLUSION: This study advances knowledge of the need to increase understanding of rehabilitation care among community members and health providers, improve care processes and resources, and foster interprofessional practice, to enhance the quality of care and promote equitable care delivery, especially in rural and remote communities.

Complications of Congenital Hernia in Pregnancy: A Case Report.

Congenital hernias, frequently misdiagnosed during pregnancy, are potentially fatal and require prompt repair. A pregnant woman with medical history of repaired congenital hernia was admitted with misdiagnosis of preeclampsia. Physical examination and chest x-ray revealed a Bochdalek hernia. Transitory stabilization prompted surgeons to postpone hernia repair, but an urgent thoracotomy was required to relieve a subsequent bowel obstruction that was complicated by an intrathoracic colonic perforation. Emergent cesarean delivery was required with a good maternal and fetal outcome. A multidisciplinary team was present in the operating room. All monitoring catheters were placed in advance in the intensive care unit. During recovery, the patient experienced ventricular fibrillation, presumed to be a manifestation of takotsubo syndrome, which responded favorably to cardiopulmonary resuscitation.

The suprachiasmatic nucleus drives day-night variations in postprandial triglyceride uptake into skeletal muscle and brown adipose tissue.

NEW FINDINGS: What is the central question of this study? What are the factors influencing day-night variations in postprandial triglycerides? What is the main finding and its importance? Rats show low postprandial plasma triglyceride concentrations early in the active period that are attributable to a higher uptake by skeletal muscle and brown adipose tissue. We show that these day-night variations in uptake are driven by the suprachiasmatic nucleus, probably via a Rev-erbα-mediated mechanism and independent of locomotor activity. These findings highlight that the suprachiasmatic nucleus has a major role in day-night variations in plasma triglycerides and that disturbances in our biological clock might be an important risk factor contributing to development of postprandial hyperlipidaemia. Energy metabolism follows a diurnal pattern, mainly driven by the suprachiasmatic nucleus (SCN), and disruption of circadian regulation has been linked to metabolic abnormalities. Indeed, epidemiological evidence shows that night work is a risk factor for cardiovascular disease, and postprandial hyperlipidaemia is an important contributor. Therefore, the aim of this work was to investigate the factors that drive day-night variations in postprandial triglycerides (TGs). Intact and SCN-lesioned male Wistar rats were subjected to an oral fat challenge during the beginning of the rest phase (day) or the beginning of the active phase (night). The plasma TG profile was evaluated and tissue TG uptake assayed. After the fat challenge, intact rats showed lower postprandial plasma TG concentrations early in the night when compared with the day. However, no differences were observed in the rate of intestinal TG secretion between day and night. Instead, there was a higher uptake of TG by skeletal muscle and brown adipose tissue early in the active phase (night) when compared with the rest phase (day), and these variations were abolished in rats bearing bilateral SCN lesions. Rev-erbα gene expression suggests this as a possible mediator of the mechanism linking the SCN and day-night variations in TG uptake. These findings show that the SCN has a major role in day-night variations in plasma TGs by promoting TG uptake into skeletal muscle and brown adipose tissue. Consequently, disturbance of the biological clock might be an important risk factor contributing to the development of hyperlipidaemia.

Circadian disruption promotes tumor growth by anabolic host metabolism; experimental evidence in a rat model.

BACKGROUND: Light at night creates a conflicting signal to the biological clock and disrupts circadian physiology. In rodents, light at night increases the risk to develop mood disorders, overweight, disrupted energy metabolism, immune dysfunction and cancer. We hypothesized that constant light (LL) in rats may facilitate tumor growth via disrupted metabolism and increased inflammatory response in the host, inducing a propitious microenvironment for tumor cells. METHODS: Male Wistar rats were exposed to LL or a regular light-dark cycle (LD) for 5 weeks. Body weight gain, food consumption, triglycerides and glucose blood levels were evaluated; a glucose tolerance test was also performed. Inflammation and sickness behavior were evaluated after the administration of intravenous lipopolysaccharide. Tumors were induced by subcutaneous inoculation of glioma cells (C6). In tumor-bearing rats, the metabolic state and immune cells infiltration to the tumor was investigated by using immunohistochemistry and flow cytometry. The mRNA expression of genes involved metabolic, growth, angiogenes and inflammatory pathways was measured in the tumor microenvironment by qPCR. Tumor growth was also evaluated in animals fed with a high sugar diet. RESULTS: We found that LL induced overweight, high plasma triglycerides and glucose levels as well as reduced glucose clearance. In response to an LPS challenge, LL rats responded with higher pro-inflammatory cytokines and exacerbated sickness behavior. Tumor cell inoculation resulted in increased tumor volume in LL as compared with LD rats, associated with high blood glucose levels and decreased triglycerides levels in the host. More macrophages were recruited in the LL tumor and the microenvironment was characterized by upregulation of genes involved in lipogenesis (Acaca, Fasn, and Pparγ), glucose uptake (Glut-1), and tumor growth (Vegfα, Myc, Ir) suggesting that LL tumors rely on these processes in order to support their enhanced growth. Genes related with the inflammatory state in the tumor microenvironment were not different between LL and LD conditions. In rats fed a high caloric diet tumor growth was similar to LL conditions. CONCLUSIONS: Data indicates that circadian disruption by LL provides a favorable condition for tumor growth by promoting an anabolic metabolism in the host.

Food in synchrony with melatonin and corticosterone relieves constant light disturbed metabolism.

Circadian disruption is associated with metabolic disturbances such as hepatic steatosis (HS), obesity and type 2 diabetes. We hypothesized that HS, resulting from constant light (LL) exposure is due to an inconsistency between signals related to food intake and endocrine-driven suprachiasmatic nucleus (SCN) outputs. Indeed, exposing rats to LL induced locomotor, food intake and hormone arrhythmicity together with the development of HS. We investigated whether providing temporal signals such as 12-h food availability or driving a corticosterone plus melatonin rhythm could restore rhythmicity and prevent the metabolic disturbances under LL conditions in male rats. Discrete metabolic improvements under these separate treatments stimulated us to investigate whether the combination of hormone treatment together with mealtime restriction (12-h food during four weeks) could prevent the metabolic alterations. LL exposed arrhythmic rats, received daily administration of corticosterone (2.5 µg/kg) and melatonin (2.5 mg/kg) in synchrony or out of synchrony with their 12-h meal. HS and other metabolic alterations were importantly ameliorated in LL-exposed rats receiving hormonal treatment in synchrony with 12-h restricted mealtime, while treatment out of phase with meal time did not. Interestingly, liver bile acids, a major indication for HS, were only normalized when animals received hormones in synchrony with food indicating that disrupted bile acid metabolism might be an important mechanism for the HS induction under LL conditions. We conclude that food-elicited signals, as well as hormonal signals, are necessary for liver synchronization and that HS arises when there is conflict between food intake and the normal pattern of melatonin and corticosterone.

Obstetric Disorders in the ICU.

Pregnant and postpartum patients represent a challenge to critical care physicians, as two patients in one have to be cared for and because specific obstetric disorders, not universally covered in formal critical care training, need to be managed. Pregnancy also alters physiologic norms, so that the critical care physician may either fail to recognize a value as abnormal in pregnancy or mistakenly identify as abnormal a value within the normal range for a pregnant woman. In this article, we will review the most frequent obstetric causes of admission of pregnant/postpartum patients to the intensive care unit (hypertensive disease of pregnancy, obstetric hemorrhage, and obstetric sepsis) along with their diagnostic criteria, clinical presentation, and recommended treatment. We will also cover some specific, although less frequent, obstetric disorders, such as acute fatty liver of pregnancy, peripartum cardiomyopathy, and amniotic fluid embolism. Our primary aim is to improve quality of care for these types of patients.

The Arcuate Nucleus: A Site of Fast Negative Feedback for Corticosterone Secretion in Male Rats.

Variations in circulating corticosterone (Cort) are driven by the paraventricular nucleus of the hypothalamus (PVN), mainly via the sympathetic autonomic nervous system (ANS) directly stimulating Cort release from the adrenal gland and via corticotropin-releasing hormone targeting the adenohypophysis to release adrenocorticotropic hormone (ACTH). Cort feeds back through glucocorticoid receptors (GRs). Here we show in male Wistar rats that PVN neurons projecting to the adrenal gland do not express GRs, leaving the question of how the ANS in the PVN gets information about circulating Cort levels to control the adrenal. Since the arcuate nucleus (ARC) shows a less restrictive blood-brain barrier, expresses GRs, and projects to the PVN, we investigated whether the ARC can detect and produce fast adjustments of circulating Cort. In low Cort conditions (morning), local microdialysis in the ARC with type I GR antagonist produced a fast and sustained increase of Cort. This was not observed with a type II antagonist. At the circadian peak levels of Cort (afternoon), a type II GR antagonist, but not a type I antagonist, increased Cort levels but not ACTH levels. Antagonist infusions in the PVN did not modify circulating Cort levels, demonstrating the specificity of the ARC to give Cort negative feedback. Furthermore, type I and II GR agonists in the ARC prevented the increase of Cort after stress, demonstrating the role of the ARC as sensor to modulate Cort release. Our findings show that the ARC may be essential to sense blood levels of Cort and adapt Cort secretion depending on such conditions as stress or time of day.

Shift Work in Rats Results in Increased Inflammatory Response after Lipopolysaccharide Administration: A Role for Food Consumption.

The suprachiasmatic nucleus (SCN) drives circadian rhythms in behavioral and physiological variables, including the inflammatory response. Shift work is known to disturb circadian rhythms and is associated with increased susceptibility to develop disease. In rodents, circadian disruption due to shifted light schedules (jet lag) induced increased innate immune responses. To gain more insight into the influence of circadian disruption on the immune response, we characterized the inflammatory response in a model of rodent shift work and demonstrated that circadian disruption affected the inflammatory response to lipopolysaccharide (LPS) both in vivo and in vitro. Since food consumption is a main disturbing element in the shift work schedule, we also evaluated the inflammatory response to LPS in a group of rats that had no access to food during their working hours. Our results demonstrated that the shift work schedule decreased basal TNF-α levels in the liver but not in the circulation. Despite this, we observed that shift work induced increased cytokine response after LPS stimulation in comparison to control rats. Also, Kupffer cells (liver macrophages) isolated from shift work rats produced more TNF-α in response to in vitro LPS stimulation, suggesting important effects of circadian desynchronization on the functionality of this cell type. Importantly, the effects of shift work on the inflammatory response to LPS were prevented when food was not available during the working schedule. Together, these results show that dissociating behavior and food intake from the synchronizing drive of the SCN severely disturbs the immune response.

Food entrains clock genes but not metabolic genes in the liver of suprachiasmatic nucleus lesioned rats.

Hepatic circadian transcription, considered to be driven by the liver clock, is largely influenced by food even uncoupling it from the suprachiasmatic nucleus (SCN). In SCN lesioned rats (SCNx) we determined the influence of a physiological feeding schedule on the entrainment of clock and clock-controlled (CCG) genes in the liver. We show that clock genes and the CCG Rev-erbα and peroxisome proliferator-activated receptor alpha (PPARα) in food-scheduled intact and SCNx have a robust diurnal differential expression persisting after a 24h fast. However, hepatic nicotinamide phosphoribosyl transferase (Nampt) shows time dependent changes that are lost in intact animals under fasting; moreover, it is unresponsive to the nutrient status in SCNx, indicating a poor reliance on liver clock genes and highlighting the relevance of SCN-derived signals for its metabolic status-related expression.

Reciprocal interaction between the suprachiasmatic nucleus and the immune system tunes down the inflammatory response to lipopolysaccharide.

Several studies have shown circadian variations in the response of the immune system suggesting a role of the suprachiasmatic nucleus (SCN). Here we show that lipopolysaccharide (LPS) administration in the beginning of the active period induced more severe responses in temperature and cytokines than LPS given in the rest period. Moreover night administered LPS increased SCN basal neuronal activity indicating a direct influence of inflammation on the SCN. Bilateral lesions of the SCN resulted in an increased inflammatory response to LPS demonstrating that an interaction between the SCN and the immune system modulates the intensity of the inflammatory response.

PPAR activation as a regulator of lipid metabolism, nitric oxide production and lipid peroxidation in the placenta from type 2 diabetic patients.

Peroxisome proliferator activated receptors (PPARs) are ligand activated transcription factors with crucial functions in lipid homeostasis, anti-inflammatory processes and placental development. Maternal diabetes induces a pro-inflammatory environment and alters placental development. We investigated whether PPARs regulate lipid metabolism and nitric oxide (NO) production in placental explants from healthy and type 2 diabetic (DM2) patients. We found decreased PPARα and PPARγ concentrations, no changes in PPARδ concentrations, and increased lipids, lipoperoxides and NO production in placentas from DM2 patients. PPARα agonists reduced placental concentrations of triglycerides and both PPARα and PPARδ agonists reduced concentrations of phospholipids, cholesteryl esters and cholesterol. PPARγ agonists increased lipid concentrations in placentas from DM2 patients and more markedly in placentas from healthy patients. Endogenous ligands for the three PPAR isotypes reduced NO production and lipoperoxidation in placentas from DM2 patients. We conclude that PPARs play a role in placental NO and lipid homeostasis and can regulate NO production, lipid concentrations and lipoperoxidation in placentas from DM2 patients.

Shift work or food intake during the rest phase promotes metabolic disruption and desynchrony of liver genes in male rats.

In the liver, clock genes are proposed to drive metabolic rhythms. These gene rhythms are driven by the suprachiasmatic nucleus (SCN) mainly by food intake and via autonomic and hormonal pathways. Forced activity during the normal rest phase, induces also food intake, thus neglecting the signals of the SCN, leading to conflicting time signals to target tissues of the SCN. The present study explored in a rodent model of night-work the influence of food during the normal sleep period on the synchrony of gene expression between clock genes and metabolic genes in the liver. Male Wistar rats were exposed to forced activity for 8 h either during the rest phase (day) or during the active phase (night) by using a slow rotating wheel. In this shift work model food intake shifts spontaneously to the forced activity period, therefore the influence of food alone without induced activity was tested in other groups of animals that were fed ad libitum, or fed during their rest or active phase. Rats forced to be active and/or eating during their rest phase, inverted their daily peak of Per1, Bmal1 and Clock and lost the rhythm of Per2 in the liver, moreover NAMPT and metabolic genes such as Pparα lost their rhythm and thus their synchrony with clock genes. We conclude that shift work or food intake in the rest phase leads to desynchronization within the liver, characterized by misaligned temporal patterns of clock genes and metabolic genes. This may be the cause of the development of the metabolic syndrome and obesity in individuals engaged in shift work.

NPY and VGF immunoreactivity increased in the arcuate nucleus, but decreased in the nucleus of the Tractus Solitarius, of type-II diabetic patients.

Ample animal studies demonstrate that neuropeptides NPY and α-MSH expressed in Arcuate Nucleus and Nucleus of the Tractus Solitarius, modulate glucose homeostasis and food intake. In contrast is the absence of data validating these observations for human disease. Here we compare the post mortem immunoreactivity of the metabolic neuropeptides NPY, αMSH and VGF in the infundibular nucleus, and brainstem of 11 type-2 diabetic and 11 non-diabetic individuals. α-MSH, NPY and tyrosine hydroxylase in human brain are localized in the same areas as in rodent brain. The similar distribution of NPY, α-MSH and VGF indicated that these neurons in the human brain may share similar functionality as in the rodent brain. The number of NPY and VGF immuno positive cells was increased in the infundibular nucleus of diabetic subjects in comparison to non-diabetic controls. In contrast, NPY and VGF were down regulated in the Nucleus of the Tractus Solitarius of diabetic patients. These results suggest an activation of NPY producing neurons in the arcuate nucleus, which, according to animal experimental studies, is related to a catabolic state and might be the basis for increased hepatic glucose production in type-2 diabetes.

figuras de agentes psicoeducativos abordando problemas de violencias en escuelas: inter-agencias, implicación, historia e intervención estrategica / Figures of psycho-educational agents facing problems of violences at school: inter agencies, involvement, history and strategic intervention

El trabajo presenta figuras de intervención de los modelos mentales situacionales construidas por agentes psicoeducativos que ejercen su práctica profesional abordando problemas de violencias en escuelas. El objetivo es comprender los diferentes enfoques, agencialidades e implicaciones en interacciones entre sujetos y problemas en sistemas de actividad de contextos educativos. Categorías del marco socio-histórico-cultural se interrelacionan con la perspectiva contextualista del cambio cognitivo. Se administró el Cuestionario sobre Situaciones-Problema de Violencia en Escuelas a 114 agentes y para su análisis se aplicó al procesamiento de datos la Matriz Multidimensional de Profesionalización Psicoeducativa. El análisis factorial evidencia confiabilidad de los instrumentos de recolección de datos e identifica sistemas representacionales de cada figura. En la co-construcción estratégica de la intervención y el desarrollo del "aprendizaje por expansión", se hallan fracturas de la memoria social y desafíos para la historización del sistema de actividad distribuidos de manera diferente en las tres figuras.

The work presents the figures of intervention of the situational mental models that are built by psycho-educational agents who develop their professional practice facing violence problems at school .The aim is to understand the different focus, agencies and involvements in interactions between subjects and problems in activity systems of educational contexts. Categories from socio-historical-cultural framework are related to contextualist perspective of cognitive change. The Questionnaire about Problem-Situations of Violence at School was administered to 114 agents and for its analysis it was appl ied the Mult idimensional Matrix of Psycho-Educational Professional Modeling. The factorial analysis demonstrates confiability of instruments of data collection and identifies representational systems of each igure. In the strategic co-construction of intervention and the development of "expansive learning", fractures in the social memory and challenges for the process of recovering the history of activity systems are found, distributed in different ways in the three Figures.

figuras de agentes psicoeducativos abordando problemas de violencias en escuelas: inter-agencias, implicación, historia e intervención estrategica / Figures of psycho-educational agents facing problems of violences at school: inter agencies, involvement, history and strategic intervention

El trabajo presenta figuras de intervención de los modelos mentales situacionales construidas por agentes psicoeducativos que ejercen su práctica profesional abordando problemas de violencias en escuelas. El objetivo es comprender los diferentes enfoques, agencialidades e implicaciones en interacciones entre sujetos y problemas en sistemas de actividad de contextos educativos. Categorías del marco socio-histórico-cultural se interrelacionan con la perspectiva contextualista del cambio cognitivo. Se administró el Cuestionario sobre Situaciones-Problema de Violencia en Escuelas a 114 agentes y para su análisis se aplicó al procesamiento de datos la Matriz Multidimensional de Profesionalización Psicoeducativa. El análisis factorial evidencia confiabilidad de los instrumentos de recolección de datos e identifica sistemas representacionales de cada figura. En la co-construcción estratégica de la intervención y el desarrollo del "aprendizaje por expansión", se hallan fracturas de la memoria social y desafíos para la historización del sistema de actividad distribuidos de manera diferente en las tres figuras.(AU)

The work presents the figures of intervention of the situational mental models that are built by psycho-educational agents who develop their professional practice facing violence problems at school .The aim is to understand the different focus, agencies and involvements in interactions between subjects and problems in activity systems of educational contexts. Categories from socio-historical-cultural framework are related to contextualist perspective of cognitive change. The Questionnaire about Problem-Situations of Violence at School was administered to 114 agents and for its analysis it was appl ied the Mult idimensional Matrix of Psycho-Educational Professional Modeling. The factorial analysis demonstrates confiability of instruments of data collection and identifies representational systems of each igure. In the strategic co-construction of intervention and the development of "expansive learning", fractures in the social memory and challenges for the process of recovering the history of activity systems are found, distributed in different ways in the three Figures.(AU)

Regulation of matrix metalloproteinases 2 and 9 activities by peroxynitrites in term placentas from type 2 diabetic patients.

Matrix metalloproteinases (MMPs) are proteolytic enzymes related to a proinflammatory environment in several diseases, including diabetes, which can be activated by reactive nitrogen species. This work aimed to determine MMP-2 and MMP-9 activities and nitration in term placentas from type 2 diabetic patients and verify the hypothesis that peroxynitrites are positive regulators of placental MMP-2 and MMP-9 activities. For this purpose, term placentas from healthy and type 2 diabetic patients were analyzed for MMP-2 and MMP-9 levels and activities, protein nitration, and nitration of MMP-2 and MMP-9. Villous explants were cultured in the presence of peroxynitrites for further evaluation of MMP-2 and MMP-9 activities. We found that MMP-2 and MMP-9 activities were increased in term placentas from diabetic patients. These changes were found even when MMP-2 protein concentrations were diminished and MMP-9 protein concentrations were not changed in the diabetic group. Increased protein nitration and specific nitration of MMP-2 and MMP-9 were found in term placentas from diabetic patients. Peroxynitrites were able to increase the activity of placental MMP-2 and MMP-9. Taken together, this study has shown for first time that peroxynitrites can nitrate and activate MMP-2 and MMP-9 in the placenta, a nitrative pathway possibly related to MMPs overactivity in the placentas from type 2 diabetic patients.

Violencias en escuelas desde la perspectiva de los actores: un desafío para la Psicología Educacional / Violences at schools from actors perspective: a challenge for Educational Psychology

Se analizan modelos mentales de situaciones de violencias en instituciones escolares que construyen agentes psicoeducativos, en la reelaboración de su experiencia en escuelas primarias, secundarias, de rama especial y organizaciones sociales conexas, de Buenos Aires y La Plata. Se administraron Cuestionarios sobre Situaciones-Problema de Violencias en Escuelas a sesenta agentes psicoeducativos y se aplicó al análisis de datos la Matriz de Análisis Multidimensional con Ejes e Indicadores de Profesionalización. Categorías del marco socio-histórico-cultural se interrelacionan con la perspectiva contextualista del cambio cognitivo en contexto educativo. Fortalezas, desafíos y nudos críticos en las tres figuras del trabajo psicoeducativo en los sistemas de actividad se vinculan a: escenas de urgencia, formación de psicólogos, rol histórico de la escolarización y vicisitudes del desarrollo en contextos sociales de desigualdades acentuadas. Los actores psicoeducativos se apropian de instrumentos de reflexión sobre la práctica en zonas de construcción social de conocimientos, abriendo nuevas dimensiones de comprensión sobre problemas e intervenciones.

The work analyses mental models of violence situations at schools that psycho-educational agents build in the reconstruction of their experience in primary, secondary and special schools and social organizations linked at Buenos Aires and La Plata cities . Questionnaires about Problem-Situations of Violences at Schools were administered to sixty psycho-educational agents and it was applied for data processing a Multidimensional Analysis Matrix with Axis and Indicators of Becoming Professional Process. Categories from socio-historical-cultural framework are related to contextualist perspective of cognitive change in educational contexts. Strengths, challenges and critical knots in the three figures of work in activity systems are linked to: urgency scenes, psychologists modeling, historic role of schooling and development events in social contexts with increased inequalities. Psycho-educational actors appropriate instruments of reflection in practice through zones of social knowledge construction, opening new dimensions for understanding problems and interventions.

Interaction between hypothalamic dorsomedial nucleus and the suprachiasmatic nucleus determines intensity of food anticipatory behavior.

Food anticipatory behavior (FAA) is induced by limiting access to food for a few hours daily. Animals anticipate this scheduled meal event even without the suprachiasmatic nucleus (SCN), the biological clock. Consequently, a food-entrained oscillator has been proposed to be responsible for meal time estimation. Recent studies suggested the dorsomedial hypothalamus (DMH) as the site for this food-entrained oscillator, which has led to considerable controversy in the literature. Herein we demonstrate by means of c-Fos immunohistochemistry that the neuronal activity of the suprachiasmatic nucleus (SCN), which signals the rest phase in nocturnal animals, is reduced when animals anticipate the scheduled food and, simultaneously, neuronal activity within the DMH increases. Using retrograde tracing and confocal analysis, we show that inhibition of SCN neuronal activity is the consequence of activation of GABA-containing neurons in the DMH that project to the SCN. Next, we show that DMH lesions result in a loss or diminution of FAA, simultaneous with increased activity in the SCN. A subsequent lesion of the SCN restored FAA. We conclude that in intact animals, FAA may only occur when the DMH inhibits the activity of the SCN, thus permitting locomotor activity. As a result, FAA originates from a neuronal network comprising an interaction between the DMH and SCN. Moreover, this study shows that the DMH-SCN interaction may serve as an intrahypothalamic system to gate activity instead of rest overriding circadian predetermined temporal patterns.

Psicólogos en formación, modelos mentales y sistemas de actividad inter-institucionales: cambio cognitivo y aprendizaje por expansión / Psychologists in modelling, mental models and inter-institutional systems of activity: cognitive change and expansive learning

El trabajo analiza figuras del psicólogo de Estudiantes de Psicología de Universidad de Buenos Aires, antes y después de las Prácticas Profesionales y de Investigación, en 2008 y 2009. El objetivo es comprender la heterogeneidad de experiencias y los cambios cognitivos y actitudinales a través de los giros en los modelos mentales de los psicólogos en formación. La participación guiada en comunidades de práctica y la implicación en procesos de internalización y externalización son fundamentales para la apropiación de instrumentos de mediación y la construcción de competencias profesionales. El análisis factorial evidencia confiabilidad de los instrumentos de recolección de datos e identifica sistemas representacionales. Se denotan fortalezas y desafíos de la profesionalización y enriquecimiento en ejes relevantes: perspectivismo, tramas intersubjetivas y psicosociales, problemas y acciones complejas, inter.-agencialidad, especificidad de la Psicología y articulación con otras disciplinas; objetivos, formulación de hipótesis, direccionalidad de intervenciones, multiplicidad de herramientas, resultados y atribuciones.

The study analyses the figures of psychologists that students of Psychology at Buenos Aires University have built, at the beginning and at the end of Undergraduate Professional and Research Apprenticeship, in 2008 and 2009. The aim is to appreciate the heterogeneity of experiences and the change of cognitions and attitudes through the shifts in mental models of future psychologists in training. Guided participation in communities of practice and the involvement in processes of internalization and externalization are important for the appropriation of mediating instruments and for the construction of professional competences. The factorial analysis demonstrates confiability of instruments of data collection and identifies representational systems. Strengths and challenges are embedded in the process of becoming professional psychologist. Data show enhancement in significant axes: perspectivism, interpersonal and psycho-social wefts, complex problems and activities, inter-agencies, specificity of Psychology and its joint with other sciences, aims, hypothesis, direction of interventions, multiplicity of tools, results and attributions.