6,414 research outputs found
Evaluating the impact of Hymenoscyphus fraxineus in Trentino (Alps, Northern Italy): first investigations
The spread of Hymenoscyphus fraxineus has been causing great concern regarding the survival of European ash (Fraxinus excelsior) throughout Europe since the 1990s. The disease was first recorded in Trentino (southern Alps, Italy) in 2012 and has spread throughout the mountain landscape, where ash trees are scattered in small and isolated stands in different valleys. The status of the disease was checked by monitoring the damage to natural regeneration and adult trees in 90 sites spread over the whole region. The survey confirmed the complete colonization by the pathogen of the whole investigated area, with high levels of damage to both young and adult ash trees. Regeneration (both seedlings and saplings) was observed to be affected by the fungus in 88 plots out of 90. Out of 4486 examined young European ashes, 2261 (50.4%) were affected and 789 (17.6%) were already dead. Ten of the 384 assayed flowering ashes (Fraxinus ornus) showed symptoms on branches and apical stems, similar to those observed for European ash. Isolation and molecular analysis proved the presence of the fungus on both symptomatic European and flowering ashes. The examined 386 adult trees showed different levels of damage, sometimes reaching more than 75% of the crown. Some individual trees (42) growing close to severely damaged trees appeared fully healthy, which suggests the possible existence of some resistant/tolerant individuals in the examined populations
Difficulty in performing activities of daily living and the need for help in older adults: evidence on social distancing models from the ELSI-COVID-19 initiative
To analyze whether the older adults with difficulty or need of help to perform basic or instrumentals activities of daily living are more socially distanced in times of COVID-19. A total of 4,035 older adults participated in the telephone interviews from the second wave of the Brazilian Longitudinal Study of Aging (ELSI-Brazil). Difficulty, need and receiving help were classified into: (1) independents; (2) had difficulty without need for care; (3) had difficulty, needed and have received care from someone within their household; (4) had difficulty, needed and have received care from someone outside their household; and (5) had difficulty and needed care but did not receive it. Social distancing was categorized as follows: did not leave their houses in the last 7 days, left their houses for essential activities and went out for non-essential activities. Multinomial regression model adjusted for age, sex, schooling and great geographical region was performed. Older adults who had difficulty, needed and have received help from within their homes (odds ratio - OR = 2.34 95%CI: 1.25-4.39) or from outside their homes (OR = 3.94; 95%CI: 2.24-6.92) were more socially distanced. Age increased the odds of not going out (OR = 1.06; 95%CI: 1.03-1.09) while be men reduced it (OR = 0.48; 95%CI: 0.33-0.70). Living in the South of Brazil has increased the odds of the respondents going out for essential activities (OR = 1.77; 95%CI: 1.01-3.10). Older adults who had difficulty, needed and have received help from within or outside their homes did not leave their homes in the last 7 days. Even with social distancing, these older adults can not have their exposure to COVID-19 reduced, weakening the theory of selective social distancing
Potential application of Saccharomyces cerevisiae strains for the fermentation of banana pulp
This paper aimed at evaluating the fermentation behavior of selected Saccharomyces cerevisiae strains in banana pulp and they were compared with commercial yeast (baker’s yeast) for subsequent production of distilled spirits. Five types of microorganisms were used: Four yeast strains obtained from accredited microbiology laboratories were isolated from domestic cachaça distilleries (UNICAMPV1, UFMG-A905, UFMG-A1007 and UFMG-A1240) and commercial pressed yeast (COMMERCIAL-yeast). The fermentation parameters of the studied S. cerevisiae strains were significantly different. COMMERCIAL-yeast and UNICAMP-V1 strain presented higher ethanol yield and better yeast efficiency in converting total reducing sugars (TRS) into alcohol, with ethanol yields of 83.07 and 94.06%, and yeast efficiency of 90.75 and 96.41%, respectively for UNICAMP V1 and COMMERCIAL-yeast. The higher alcohol contents of 82.26 and 78.05 mg/100 ml anhydrous alcohol were obtained by the UNICAMP-V1 and COMMERCIAL-yeast, respectively. No significant differences in fermentative parameters were observed between COMMERCIAL-yeast and UNICAMP-V1 strain. The UFMG-A1240 strain showed the lowest ethanol yield and therefore not suitable for the production of distilled spirits made of bananas, despite being useful for the production of cachaça. Methanol contents did not significantly vary among the five strains tested, except for UFMG-A1007, which produced significantly higher quantities of 0.19 ml/100 ml anhydrous alcohol. However, higher alcohols contents varied significantly between the five strains tests, with the UFMG-A1007 and UFMG-A1240 strains producing the lowest quantities of higher alcohols (30.04 and 48.69 mg/100 ml anhydrous alcohol, respectively). In conclusion, the S. cerevisiae strains UNICAMP-V1 and the COMMERCIAL-yeast showed better fermentation behavior, did not produce high methanol and higher alcohols amounts, and therefore were recommended for the production of distilled spirits made of banana in pilot-scale plants.Key words: Yeast, Saccharomyces cerevisiae, alcoholic fermentation, banana spirits
Free radical scavenging activity of Pterogyne nitens Tul. (Fabaceae)
As part of our ongoing research on antioxidant agents from Brazilian flora, twenty extracts and fractions obtained from Pterogyne nitens Tulasne (Fabaceae) were screened for free radical scavenging activity by using ABTS [2,2’-azinobis(3-ethylenebenzothiazoline-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl-hydrate) radicals colorimetric assay and -carotene bleaching test. The strongest activity was found in ethyl acetate fraction from the stem barks, exhibiting IC50 values (inìg/ml) of 2.10 ± 0.1 and 10.2 ± 0.3 on ABTS•+ and DPPH•, respectively. Additionally, chromatographic fractionation of stem barks yielding myricetin, quercitrin and mirycetrin, three flavonols with remarkable antioxidant activity
Impact of carvedilol on the mitochondrial damage induced by hypoxanthine and xantine oxidase: what role in myocardial ischemia and reperfusion?
OBJECTIVES: The cardioprotective effects of carvedilol (CV) may be explained in part by interactions with heart mitochondria. The objective of this work was to study the protection afforded by CV against oxidative stress induced in isolated heart mitochondria by hypoxanthine and xanthine oxidase (HX/XO), a well-known source of reactive oxygen species (ROS) in the cardiovascular system. METHODS: Mitochondria were isolated from Wistar rat hearts (n = 8) and incubated with HX/XO in the presence and in the absence of calcium. Several methods were used to assess the protection afforded by CV: evaluation of mitochondrial volume changes (by measuring changes in the optical density of the mitochondrial suspension), calcium uptake and release (with a fluorescent probe, Calcium Green 5-N) and mitochondrial respiration (with a Clark-type oxygen electrode). RESULTS: CV decreased mitochondrial damage associated with ROS production by HX and XO, as verified by the reduction of mitochondrial swelling and increase in mitochondrial calcium uptake. In the presence of HX and XO, CV also ameliorated mitochondrial respiration in the active phosphorylation state and prevented decrease in the respiratory control ratio (p < 0.05) and in mitochondrial phosphorylative efficiency (p < 0.001). CONCLUSIONS: The data indicate that CV partly protected heart mitochondria from oxidative damage induced by HX and XO, which may be useful during myocardial ischemia and reperfusion. It is also suggested that mitochondria may be a priority target for the protective action of some compounds
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