Dietary nitrate supplementation effect on dynamic cerebral autoregulation in normoxia and acute hypoxia

We tested the hypothesis that increasing the nitric oxide (NO) bioavailability by dietary nitrate would recover the hypoxia-induced reduction in dynamic cerebral autoregulation (CA). Twelve healthy males (age 21 ± 2 years) completed four days of dietary supplementation with a placebo or inorganic nitrate drink (140-ml beetroot juice per day) followed by 60-min of normoxia or hypoxia (fraction of inspired oxygen [FiO(2)] = 13%). Duplex ultrasonography was used to perform volumetric change-based assessment of dynamic CA in the internal carotid artery (ICA). Dynamic CA was assessed by rate of regulation (RoR) of vascular conductance using the thigh-cuff method. Four days of beetroot supplementation increased circulating nitrate by 208 [171,245] μM (mean difference [95% confidence interval]) compared with placebo. Dynamic CA was lower in hypoxia than normoxia (RoR Δ−0.085 [−0.116, −0.054]). Compared with placebo, nitrate did not alter dynamic CA in normoxia (RoR Δ−0.022 [−0.060, 0.016]) or hypoxia (RoR Δ0.017 [−0.019, 0.053]). Further, nitrate did not affect ICA vessel diameter, blood velocity or flow in either normoxia or hypoxia. Increased bioavailability of NO through dietary nitrate supplementation did not recover the hypoxia-induced reduction in dynamic CA. This suggests the mechanism of hypoxia-induced reduction in dynamic CA does not relate to the availability of NO

Dietary nitrate supplementation effect on dynamic cerebral autoregulation in normoxia and acute hypoxia

We tested the hypothesis that increasing the nitric oxide (NO) bioavailability by dietary nitrate would recover the hypoxia-induced reduction in dynamic cerebral autoregulation (CA). Twelve healthy males (age 21 ± 2 years) completed four days of dietary supplementation with a placebo or inorganic nitrate drink (140-ml beetroot juice per day) followed by 60-min of normoxia or hypoxia (fraction of inspired oxygen [FiO2] = 13%). Duplex ultrasonography was used to perform volumetric change-based assessment of dynamic CA in the internal carotid artery (ICA). Dynamic CA was assessed by rate of regulation (RoR) of vascular conductance using the thigh-cuff method. Four days of beetroot supplementation increased circulating nitrate by 208 [171,245] μM (mean difference [95% confidence interval]) compared with placebo. Dynamic CA was lower in hypoxia than normoxia (RoR Δ-0.085 [-0.116, -0.054]). Compared with placebo, nitrate did not alter dynamic CA in normoxia (RoR Δ-0.022 [-0.060, 0.016]) or hypoxia (RoR Δ0.017 [-0.019, 0.053]). Further, nitrate did not affect ICA vessel diameter, blood velocity or flow in either normoxia or hypoxia. Increased bioavailability of NO through dietary nitrate supplementation did not recover the hypoxia-induced reduction in dynamic CA. This suggests the mechanism of hypoxia-induced reduction in dynamic CA does not relate to the availability of NO

A importância da afetividade na educação

Affectivity is a human psychological state, so it is part of schooling and the teaching-learning process. The aim of this article is to demonstrate how and why affectivity is linked to the teaching-learning process, emphasizing that without the establishment of affective bonds, it is not possible for the learner to provide energy so that his desire to learn is manifested. In this way, it is possible to affirm that there will be no learning if there is no cognitive and affective development, concomitantly. The affectivity has been the subject of study by many authors, and all are unanimous in stating that integral human development must have cognition affection. Not infrequently, we find children who do not learn or who do not wish to learn since they are unable to establish affective bonds with the school and with teachers. The school is the first living environment away from parents and family, so it should be welcoming and amenable to affective development.La afectividad es un estado psicológico humano, luego forma parte de la escolarización y del proceso de enseñanza-aprendizaje. El objetivo de este artículo es demostrar cómo y por qué la afectividad está vinculada al proceso de enseñanza-aprendizaje, resaltando que, sin el establecimiento de vínculos afectivos, no es posible que el alumno disponga energía para que su deseo de aprender se manifieste. De esta forma, es posible afirmar que no habrá aprendizaje si no existe el desarrollo cognitivo y afectivo, concomitantemente. La afectividad ha sido objeto de estudio de muchos autores, y todos son unánimes en afirmar que el desarrollo humano integral debe tener cognición afección. No es raro encontrar niños que no aprenden o que no desean aprender, ya que no pueden establecer vínculos afectivos con la escuela y los profesores. La escuela es el primer ambiente de vivencia lejos de los padres y de la familia, por lo que debe ser acogedora y pasible al desarrollo afectivo.A afetividade é um estado psicológico humano, logo faz parte da escolarização e do processo de ensino-aprendizagem. O objetivo deste artigo é demonstrar como e porque a afetividade está vinculada ao processo de ensino-aprendizagem, ressaltando que, sem o estabelecimento de vínculos afetivos, não é possível o aprendente disponibilizar energia para que seu desejo de aprender se manifeste. Desta forma, é possível afirmar que não haverá aprendizagem se não houver o desenvolvimento cognitivo e afetivo, concomitantemente. A afetividade tem sido alvo de estudo de muitos autores, e todos são unânimes em afirmarem que o desenvolvimento humano integral deve ter cognição afeição. Não raro, encontramos crianças que não aprendem ou, que não desejam aprender, uma vez que são incapazes de estabelecer vínculos afetivos com a escola e com os professores. A escola é o primeiro ambiente de vivência longe dos pais e da família, por isso deve ser acolhedor e passível aos desenvolvimento afetivo

A importância da afetividade na educação

A afetividade é um estado psicológico humano, logo faz parte da escolarização e do processo de ensino-aprendizagem. O objetivo deste artigo é demonstrar como e porque a afetividade está vinculada ao processo de ensino-aprendizagem, ressaltando que, sem o estabelecimento de vínculos afetivos, não é possível o aprendente disponibilizar energia para que seu desejo de aprender se manifeste. Desta forma, é possível afirmar que não haverá aprendizagem se não houver o desenvolvimento cognitivo e afetivo, concomitantemente. A afetividade tem sido alvo de estudo de muitos autores, e todos são unânimes em afirmarem que o desenvolvimento humano integral deve ter cognição afeição. Não raro, encontramos crianças que não aprendem ou, que não desejam aprender, uma vez que são incapazes de estabelecer vínculos afetivos com a escola e com os professores. A escola é o primeiro ambiente de vivência longe dos pais e da família, por isso deve ser acolhedor e passível aos desenvolvimento afetivo

Hypoxia alters posterior cingulate cortex metabolism during a memory task: a 1H fMRS study

Environmental hypoxia (fraction of inspired oxygen (F(I)O(2)) ~ 0.120) is known to trigger a global increase in cerebral blood flow (CBF). However, regionally, a heterogeneous response is reported, particularly within the posterior cingulate cortex (PCC) where decreased CBF is found after two hours of hypoxic exposure. Furthermore, hypoxia reverses task-evoked BOLD signals within the PCC, and other regions of the default mode network, suggesting a reversal of neurovascular coupling. An alternative explanation is that the neural architecture supporting cognitive tasks is reorganised. Therefore, to confirm if this previous result is neural or vascular in origin, a measure of neural activity that is not haemodynamic-dependant is required. To achieve this, we utilised functional magnetic resonance spectroscopy to probe the glutamate response to memory recall in the PCC during normoxia (F(I)O(2) = 0.209) and after two hours of poikilocapnic hypoxia (F(I)O(2) = 0.120). We also acquired ASL-based measures of CBF to confirm previous findings of reduced CBF within the PCC in hypoxia. Consistent with previous findings, hypoxia induced a reduction in CBF within the PCC and other regions of the default mode network. Under normoxic conditions, memory recall was associated with an 8% increase in PCC glutamate compared to rest (P = 0.019); a change which was not observed during hypoxia. However, exploratory analysis of other neurometabolites showed that PCC glucose was reduced during hypoxia compared to normoxia both at rest (P = 0.039) and during the task (P = 0.046). We conclude that hypoxia alters the activity-induced increase in glutamate, which may reflect a reduction in oxidative metabolism within the PCC. The reduction in glucose in hypoxia reflects continued metabolism, presumably by non-oxidative means, without replacement of glucose due to reduced CBF

“Quem Não Pega, Não Se Apega”? Interações e Vínculos com Bebês Acolhidos

This study investigated the emotional bonds between caregivers and foster infants, and how these were meant and enabled in a foster care institution. An exploratory study was conducted, following the interactions of three babies (age: 4-13 months). Video recordings were weekly made, along three months, in addition to interviews and field diaries. Observational categories were quantified. Results indicate low caregivers’ responsiveness to the infants’ expressions. Caregivers avoided physical contacts. Institutionalized guidelines (as “don´t pick-up the baby to not get attached”) circunscribed interactions. Strong emotional bonds were established with certain children. It was discussed how emotional socialization, caregivers’ responsiveness and the context organization are related to infant’s socio-affective development, the construction of bonds and the process of learning.Investigou-se o estabelecimento de vínculos entre cuidadores e bebês acolhidos, e como estes eram significados e (im)possibilitados em instituição de acolhimento. Utilizando videogravações semanais, por três meses, entrevistas e diários de campo, conduziu-se estudo exploratório, descritivo-qualitativo, em contexto naturalístico, acompanhando interações entre cuidadoras e 3 bebês (idade: 4 a 13 meses). Categorias observacionais foram quantificadas. Observou-se baixa responsividade às expressões dos bebês. Contatos físicos eram evitados pelas cuidadoras. Orientações institucionalizadas (como não pegue para não se apegar) mostraram-se significativos circunscritores das interações. Laços afetivos se estabeleceram apenas com determinadas crianças. Discutiu-se como a socialização emocional, a responsividade das cuidadoras e a organização do contexto relacionavam-se com o desenvolvimento socioafetivo, a construção de vínculos e os processos de aprendizagens