Potencial fitot?xico de Pterodon polygalaeflorus Benth (Leguminosae) sobre Acanthospermum australe (Loefl.) O. Kuntze e Senna occidentalis (L.).

O objetivo dessa pesquisa foi sintetizar e caracterizar a atividade alelop?tica de derivados do ?cido 6?,7??di-hidroxivouacapan-17???ico, isolado de sementes de Pterodon polygalaeflorus Benth (Leguminosae). A caracteriza??o dos compostos envolveu espectrometria no infravermelho (IV) e resson?ncia magn?tica nuclear de hidrog?nio e de carbono (RMN de 1H e de 13C) incluindo experimentos em duas dimens?es (COSY 1H 1H, HMQC e HMBC). Os efeitos alelop?ticos foram avaliados atrav?s de bioensaios de germina??o de sementes e crescimento radicular, em condi??es controladas de temperatura (25 ?C) e fotoper?odo (12 h claro/12h escuro), durante 72 horas. Concentra??es de 1,0, 100,0 e 1000,0 mg.L-1 foram testadas. Senna occidentalis (fedegoso) e Acanthospermum australe (carrapichinho) foram utilizadas como esp?cies daninhas alvo. Foi observado que o efeito alelop?tico dos compostos aumentou em fun??o do aumento da concentra??o, mostrando assim uma rela??o dose dependente. A tend?ncia geral observada nos resultados foi de aumento da intensidade dos efeitos alelop?ticos inibit?rios em fun??o do aumento da concentra??o. A N-Etil-6?-acetoxi-7?- hidroxivouacapan-17??amida e N,N-Dietil-6?-acetoxi-7?-hidroxivouacapan-17??amida foram os derivados que apresentaram maior efeito inibidor da germina??o e do crescimento radicular do fedegoso e do carrapichinho. Portanto, esses compostos representam grande potencial aleloquimico contra essas ervas daninha.The objectives of this research were synthesize and characterize the allelopatic activity of 6a,7b?di-hydroxyvouacapan-17b?oic acid derivatives, isolated from seeds of Pterodon polygalaeflorus Benth (Leguminosae). The compound characterization processes involve in infrared spectrometry (IR) and hydrogen and carbon nuclear magnetic resonance (1H and 13C NMR) including experiments in double dimensions (COSY 1H 1H, HMQC and HMBC). Allellopathic effects were evaluated by bioassays, carried out at controlled 25 ?C temperature and photoperiod (12h light/12h dark), during 72 hours. Sample concentrations of 1,0, 100,0 and 1000,0 mg.L-1 were tested. Senna occidentalis (fedegoso) and Acanthospermum australe (carrapichinho) were used as the target weed plants. Was observed that the allelopatic effect of the compounds increased as a function of the enhancement of concentration, thus showing a relation dose dependence. The N-ethyl-6?-acethoxy- 7?-hydroxyvouacapan-17??amide and N,N-diethyl-6?-acethoxy-7?-hydroxyvouacapan-17??amide were the derivatives that present the biggest inhibitory effect on seed germination and root growth of fedegoso and carrapichinho. Therefore, these compounds represent the most allelochemical potential against these weeds

Chemical constituents and allelopathic activity of the essential oil from leaves of Eremanthus erythropappus.

The essential oil from leaves of Eremanthus erythropappus (DC.) MacLeish (Asteraceae) collected in South-eastern Brazil was extracted using a combination of water and steam distillation and investigated by chromatography/mass spectrometry (GC-MS). The sesquiterpene hydrocarbons were predominant (46.6%), followed by oxygenated sesquiterpenes (29.3%) and monoterpene hydrocarbons (18.8%). The major compounds were (?)-caryophyllene (29.3%), caryophyllene oxide (22.1%) and ?-pinene (12.8%). The allelopathic activity of E. erythropappus essential oil on the seed germination and radicle length of seedlings was evaluated in lettuce (Lactuca sativa L.), tomato (Lycopersicum esculentum Mill.) and in two field weeds (field mustard ? Brassica rapa L. and hairy beggarticks ? Bidens pilosa L.). Among the weed species tested, the most significant inhibition of seed germination was observed in field mustard, as measured by the half?minimal inhibitory concentration, IC50 (IC50?=?26.5??L mL?1), and the most significant inhibitory effect on radicle length of seedlings was observed in seedlings of hairy beggarticks (IC50?=?16.3??L mL?1). In contrast, the lowest allelopathic effects of E. erythropappus essential oil on seed germination and radicle length of seedlings were observed in tomato (IC50?=?>200??L mL?1 and 130.1??L mL?1 respectively) and lettuce (IC50?=?97.1??L mL?1 and 35.1??L mL?1 respectively). These results revealed significant allelopathic potential of E. erythropappus essential oil against weeds, but minimal effect on lettuce and tomato germination, and thus suggests it is feasible to use E. erythropappus sustainability as an eco-friendly bioherbicide in cropping settings

AN EXPLORATION OF HEALTH AND SAFETY MANAGEMENT ISSUES IN NIGERIA’S EFFORT TO INDUSTRIALIZE

All organizations have a duty of care to ensure that employees and other persons who may be affected by the company’s undertakings remain safe at all times. This paper examines the background of occupational health and safety (OHS) practices in Nigeria, and highlights the importance of mitigating the OHS challenges identified from the moral, legal, financial and other dimensions. In the Nigerian context, the need to reinforce health and safety management (HSM) issues is exemplified from the unsavory recurrent reports of plane crashes in the aviation industry, high rates of motor vehicle accidents, numerous cases of death due to poisoning in the solid mineral sector, frequent accounts of disasters in the petroleum sector arising from oil spills, pipeline vandalism as well as accidents involving petroleum tankers. More effective and efficient management of these issues is a sine qua non to the industrialization efforts of an economy. Against the background of extant HS legislation in Nigeria, some reasons for the frequent violations of OHS standards and norms by the operators were identified as bribery and corruption in the system, the ‘Nigerian Factor’, inadequate funding of monitoring institutions, low level of education of employees as well as problems of persistent unemployment in the country. While recommending ways to mitigate the OHS flaws in Nigerian institutions, the relative duties and responsibilities of stakeholders in the OHS business were identified. The paper concludes by noting the importance of a virile HSM environment to the overall economic development and industrialization of the nation

Selective oxidation of lupeol by iodosylbenzene catalyzed by manganese porphyrins.

Manganese porphyrin-catalyzed oxidation of lupeol by iodosylbenzenewas achieved undermild conditionswith low isolated yields but with remarkable selectivity, depending on the catalyst of choice. Mn(III) mesotetraphenylporphyrin and Mn(III) meso-tetrakis(4-carbomethoxyphenyl)porphyrin provided an entry for the preparation of 3?,30-dihydroxylup-20(29)-ene (6?14% yields), whereas Mn(III) ?-octabromo-meso-tetrakis(4- carbomethoxyphenyl)porphyrin led to 20-oxo-3?-hydroxy-29-norlupeol (6% yield), as single products. Unreacted lupeol was recovered in quantitative yield. The oxidative transformations at lupeol C20 or C30 take place with no need for protection of C3 hydroxyl moiety

Physicochemical characteristics of Brazilian green propolis evaluated during a six-year period.

Background: Propolis has been used as a natural health product mainly due to the presence of polyphenols, flavonoids, phenolic aldehydes, amino acids, vitamins and others bioactive constituents. To this natural substance are attributed different biological and pharmacological properties which are influenced by its chemical composition and organoleptic properties. The aim of this work was to evaluate the physicochemical properties and parameters of green propolis collected during a period of six years (2008-2013) in the state of Minas Gerais, located at the southeastern region of Brazil. Methods: The methodology were in accordance with Brazilian legislation on the identity and quality standards of propolis. The evaluated parameters of hydroalcoholic from green propolis were total flavonoids, antioxidant activity - DPPH method, oxidation index, wax content, humidity and insoluble impurities. Results: Propolis samples collected in different seasons during the years 2008 to 2013 presented mean values of total flavonoids (3.4 ? 0.11 mg/g), antioxidant activity DPPH (4.76 ? 0.16 ?g/mL), oxidation index (3, 4 ? 0.33 seconds) and wax (15.14 ? 0.78% m/m), which are in accordance with Brazilian legislation. Conclusion: Green propolis did not show abrupt seasonal changes during the six years of investigation, and may be considered as an adequate functional ingredient

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost