42 research outputs found
Espaços não formais de educação ambiental como ferramenta de sensibilização e conscientização socioambiental no município de Araraquara-SP
Non-formal education occurs in spaces where there are intentional interactive processes that are collectively constructed. The non-formal spaces of environmental education (EE) are places where people can experience how the natural environment is essential for the maintenance of ecosystem relationships that guarantee the maintenance of life in all its forms. In this sense, the aim of this article is to present an experience report of an EE program, developed for students from the 6th to the 9th year of elementary school at a public school in the city of Araraquara. For the 6th grade students, an eco-pedagogical trail was programmed from the school to the spring of the Água Branca stream, and for the 7th, 8th and 9th grade students, monitored technical visits were programmed to the Fonte Luminosa Water Treatment Station, Araraquara Sewage Plant and Solid Waste Treatment Station/Acácia Recyclable Material Collectors Cooperative. The selection of these places was made in order to allow students to get to know, throughout the final years of elementary school, the entire chain of environmental sanitation of Araraquara. The monitored visits, in addition to contributing to the understanding of the technical aspects related to the sanitation chain, are configured as an important tool for reflection on the relationships established between human beings and nature and between human beings themselves, reinforcing the socio-environmental bias of EE. Works in this direction can contribute to the construction of more robust and effective EE programs, towards a transformative education.A educação não formal ocorre em espaços onde há processos interativos intencionais construídos coletivamente. Os espaços não formais de educação ambiental (EA) são locais onde as pessoas podem vivenciar como o meio ambiente natural é imprescindível para a manutenção das relações ecossistêmicas que garantem a manutenção da vida em todas as suas formas. Assim, o objetivo deste artigo é apresentar um relato de experiência de um programa de EA, elaborado para estudantes do 6º ao 9º ano do ensino fundamental de uma escola pública na cidade de Araraquara. Para os discentes do 6º ano, foi programada uma trilha ecopedagógica da escola à Nascente do Córrego Água Branca, e para os estudantes dos 7º, 8º e 9º anos foram programadas visitas técnicas monitoradas à Estação de Tratamento de Água da Fonte Luminosa, Estação de Tratamento de Esgoto de Araraquara e Estação de Tratamento de Resíduos Sólidos/Cooperativa de Catadores de Materiais Recicláveis Acácia. A seleção desses locais se deu a fim de possibilitar aos estudantes conhecerem, ao longo dos anos finais do ensino fundamental, toda a cadeia do saneamento ambiental de Araraquara. As visitas monitoradas, além de contribuírem para o entendimento dos aspectos técnicos relacionados à cadeia de saneamento, se configuram como uma importante ferramenta de reflexão acerca das relações estabelecidas entre o ser humano e a natureza e entre os próprios seres humanos, reforçando o viés socioambiental da EA. Trabalhos nesse sentido podem contribuir para a construção de programas de EA mais robustos e eficazes, em direção a uma educação transformadora
Post-Weaning Protein Malnutrition Increases Blood Pressure and Induces Endothelial Dysfunctions in Rats
Malnutrition during critical periods in early life may increase the subsequent risk of hypertension and metabolic diseases in adulthood, but the underlying mechanisms are still unclear. We aimed to evaluate the effects of post-weaning protein malnutrition on blood pressure and vascular reactivity in aortic rings (conductance artery) and isolated-perfused tail arteries (resistance artery) from control (fed with Labina®) and post-weaning protein malnutrition rats (offspring that received a diet with low protein content for three months). Systolic and diastolic blood pressure and heart rate increased in the post-weaning protein malnutrition rats. In the aortic rings, reactivity to phenylephrine (10−10–3.10−4 M) was similar in both groups. Endothelium removal or L-NAME (10−4 M) incubation increased the response to phenylephrine, but the L-NAME effect was greater in the aortic rings from the post-weaning protein malnutrition rats. The protein expression of the endothelial nitric oxide isoform increased in the aortic rings from the post-weaning protein malnutrition rats. Incubation with apocynin (0.3 mM) reduced the response to phenylephrine in both groups, but this effect was higher in the post-weaning protein malnutrition rats, suggesting an increase of superoxide anion release. In the tail artery of the post-weaning protein malnutrition rats, the vascular reactivity to phenylephrine (0.001–300 µg) and the relaxation to acetylcholine (10−10–10−3 M) were increased. Post-weaning protein malnutrition increases blood pressure and induces vascular dysfunction. Although the vascular reactivity in the aortic rings did not change, an increase in superoxide anion and nitric oxide was observed in the post-weaning protein malnutrition rats. However, in the resistance arteries, the increased vascular reactivity may be a potential mechanism underlying the increased blood pressure observed in this model
Low mercury concentration produces vasoconstriction, decreases nitric oxide bioavailability and increases oxidative stress in rat conductance artery.
Mercury is an environmental pollutant that reduces nitric oxide (NO) bioavailability and increases oxidative stress, having a close link with cardiovascular diseases, as carotid atherosclerosis, myocardial infarction, coronary heart disease and hypertension. One of the main sites affected by oxidative stress, which develops atherosclerosis, is the aorta. Under acute exposure to low mercury concentrations reactive oxygen species (ROS) production were only reported for resistance vessels but if low concentrations of mercury also affect conductance arteries it is still unclear. We investigated the acute effects of 6 nM HgCl(2) on endothelial function of aortic rings measuring the reactivity to phenylephrine in rings incubated, or not, with HgCl(2) for 45 min, the protein expression for cyclooxygenase 2 (COX-2) and the AT1 receptor. HgCl(2) increased Rmax and pD2 to phenylephrine without changing the vasorelaxation induced by acetylcholine and sodium nitroprusside. Endothelial damage abolished the increased reactivity to phenylephrine. The increase of Rmax and pD2 produced by L-NAME was smaller in the presence of HgCl(2). Enalapril, losartan, indomethacin, furegrelate, the selective COX-2 inhibitor NS 398, superoxide dismutase and the NADPH oxidase inhibitor apocynin reverted HgCl(2) effects on the reactivity to phenylephrine, COX-2 protein expression was increased, and AT1 expression reduced. At low concentration, below the reference values, HgCl(2) increased vasoconstrictor activity by reducing NO bioavailability due to increased ROS production by NADPH oxidase activity. Results suggest that this is due to local release of angiotensin II and prostanoid vasoconstrictors. Results also suggest that acute low concentration mercury exposure, occurring time to time could induce vascular injury due to endothelial oxidative stress and contributing to increase peripheral resistance, being a high risk factor for public health
A Single Resistance Exercise Session Improves Aortic Endothelial Function in Hypertensive Rats
Cloning and characterization of bifunctional enzyme farnesyl diphosphate/geranylgeranyl diphosphate synthase from Plasmodium falciparum
BACKGROUND: Isoprenoids are the most diverse and abundant group of natural products. In Plasmodium falciparum, isoprenoid synthesis proceeds through the methyl erythritol diphosphate pathway and the products are further metabolized by farnesyl diphosphate synthase (FPPS), turning this enzyme into a key branch point of the isoprenoid synthesis. Changes in FPPS activity could alter the flux of isoprenoid compounds downstream of FPPS and, hence, play a central role in the regulation of a number of essential functions in Plasmodium parasites. METHODS: The isolation and cloning of gene PF3D7_18400 was done by amplification from cDNA from mixed stage parasites of P. falciparum. After sequencing, the fragment was subcloned in pGEX2T for recombinant protein expression. To verify if the PF3D7_1128400 gene encodes a functional rPfFPPS protein, its catalytic activity was assessed using the substrate [4-(14)C] isopentenyl diphosphate and three different allylic substrates: dimethylallyl diphosphate, geranyl diphosphate or farnesyl diphosphate. The reaction products were identified by thin layer chromatography and reverse phase high-performance liquid chromatography. To confirm the product spectrum formed of rPfFPPS, isoprenic compounds were also identified by mass spectrometry. Apparent kinetic constants K(M) and V(max) for each substrate were determined by Michaelis–Menten; also, inhibition assays were performed using risedronate. RESULTS: The expressed protein of P. falciparum FPPS (rPfFPPS) catalyzes the synthesis of farnesyl diphosphate, as well as geranylgeranyl diphosphate, being therefore a bifunctional FPPS/geranylgeranyl diphosphate synthase (GGPPS) enzyme. The apparent K(M) values for the substrates dimethylallyl diphosphate, geranyl diphosphate and farnesyl diphosphate were, respectively, 68 ± 5 μM, 7.8 ± 1.3 μM and 2.06 ± 0.4 μM. The protein is expressed constitutively in all intra-erythrocytic stages of P. falciparum, demonstrated by using transgenic parasites with a haemagglutinin-tagged version of FPPS. Also, the present data demonstrate that the recombinant protein is inhibited by risedronate. CONCLUSIONS: The rPfFPPS is a bifunctional FPPS/GGPPS enzyme and the structure of products FOH and GGOH were confirmed mass spectrometry. Plasmodial FPPS represents a potential target for the rational design of chemotherapeutic agents to treat malaria
Basal measurements from the right ventricle strips.
<p>The effect of myocardial infarction in rats with continuous exposure to HgCl<sub>2</sub> on the basal conditions of isometric force (A), time to peak tension (B), relaxation time to 90% (C), +dF/dt (D) and −dF/dt (E) of rat right ventricular strips from the Control, MI and HgCl<sub>2</sub>-MI groups. The results are reported as the means ± SEM for 10–12 animals per group. MI = myocardial infarction; dF/dt = time derivatives of right ventricular force development. *P<0.05 <i>vs</i> Control and HgCl<sub>2</sub>-MI; # P<0.05 <i>vs</i> Control (one-way ANOVA followed by Tukey's <i>post hoc</i> tests).</p
Response to β-adrenergic stimuli.
<p>The effect of myocardial infarction in rats with continuous exposure to HgCl<sub>2</sub> on isoproterenol (ISO, 10<sup>−4</sup> M) conditions compared to steady-state condition of isometric force. The results are reported as the means ± SEM for 10–12 animals per group. MI = myocardial infarction; # P<0.05 <i>vs</i> Control (one-way repeated measures ANOVA followed by the Tukey's <i>post hoc</i> test).</p