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81.
Aristolochic acids (AAs) are nephrotoxic and carcinogenic derivatives found in several Aristolochia species. To date, the toxicity of AAs has been inferred only from the effects observed in patients suffering from a kidney disease called “aristolochic acid nephropathy” (AAN, formerly known as “Chinese herbs nephropathy”). More recently, the chronic poisoning with Aristolochia seeds has been considered to be the main cause of Balkan endemic nephropathy, another form of chronic renal failure resembling AAN. So far, it was assumed that AAs can enter the human food chain only through ethnobotanical use (intentional or accidental) of herbs containing self-produced AAs. We hypothesized that the roots of some crops growing in fields where Aristolochia species grew over several seasons may take up certain amounts of AAs from the soil, and thus become a secondary source of food poisoning. To verify this possibility, maize plant (Zea mays) and cucumber (Cucumis sativus) were used as a model to substantiate the possible significance of naturally occurring AAs’ root uptake in food chain contamination. This study showed that the roots of maize plant and cucumber are capable of absorbing AAs from nutrient solution, consequently producing strong peaks on ultraviolet HPLC chromatograms of plant extracts. This uptake resulted in even higher concentrations of AAs in the roots compared to the nutrient solutions. To further validate the measurement of AA content in the root material, we also measured their concentrations in nutrient solutions before and after the plant treatment. Decreased concentrations of both AAI and AAII were found in nutrient solutions after plant growth. During this short-term experiment, there were much lower concentrations of AAs in the leaves than in the roots. The question is whether these plants are capable of transferring significant amounts of AAs from the roots into edible parts of the plant during prolonged experiments.  相似文献   
82.
Current flood risk strategies in Malawi are characterized by community-based flood risk management (CB-FRM), even though studies explicitly documenting evidence of successful CB-FRM remain limited. This paper investigates the realities and challenges of CB-FRM as seen through a lens of different stakeholders. In order to capture the experiences of CB-FRM, a predominantly qualitative research framework was developed. In 2016, 11 focus group discussions with stakeholder groups (local communities, local government and non-governmental organisations) were held. Additionally, informal discussions, field visits, a short survey and an extensive desk study were undertaken. The findings were analysed according to the major themes that emerged related to the realities and challenges of specific stakeholder groups. Although response and relief still remain prominent components of CB-FRM in Malawi, a number of mitigation and preparedness activities is observed. However, a lack of in-country resources, relief-oriented aid approaches and an ‘aid dependency’ syndrome represent obstacles. Different stakeholder groups share similar challenges in terms of financing, participation, decentralised governance and project management. Lack of project sustainability and localised ownership also emerged as major challenges. The identified challenges shed light on the frontiers and directions in which improvements are needed, thus offering a valuable contribution to the existing knowledgebase.  相似文献   
83.
Belgrade, capital city of Serbia, has over 1,600,000 inhabitants and over 400,000 vehicles trafficking every day on its streets. The investigation of soil pollution was performed by sequential extraction analysis to investigate the availability of potentially toxic metals (Zn, Cd, Pb, Co, Ni, Cu, Cr and Mn) under different oxidation and pH conditions. All investigated metals were mainly extracted from soils with neutral or acidic extractants. Serious pollution was observed along roads and streets with high traffic frequency, but Pb and Ni pollution was the highest since their concentrations exceed both soil Serbian standard and Canadian guidance values and is characteristic for all investigated sites. Cd, Cu, Cr and Zn concentrations are moderately high since they are between Canadian guideline and Serbian standard.  相似文献   
84.
Five variants of mixtures of different synthetic fibres at different area ratios were manufactured into needled nonwovens intended to be used as a filtering material for respiratory protection. Two variants were produced according to an earlier patent, and the contents of the other three was completely new. Samples of the nonwovens were tested for sodium chloride particles penetration and for breathing resistance. The results showed that one variant of a nonwoven, designated PP/PPFM, had very valuable filtering properties and that those properties were stable in time.  相似文献   
85.
This article contains the results of research into the impact of implementation of the requirements mentioned in Standard No. OHSAS 18001:2007 to reduce the number of injuries at work and the financial costs incurred in this way. The study was conducted on a determined sample by a written questionnaire survey method in the Republic of Croatia. The objective of the empirical research is to determine the impact of implementation of the requirements of Standard No. OHSAS 18001:2007 to reduce the number of injuries at work and financial costs in Croatia in business organizations that implement these requirements. To provide a broader picture, the research included the collection and analysis of data on the impact of the Standard No. OHSAS 18001:2007 on accidents and fatalities at work. Research findings are based on the analysis of performed statistical data where correlation and regression analysis has been applied.  相似文献   
86.
This paper presents daily, monthly and yearly variations of PAH mass concentrations measured in PM(10) particle fraction, collected at one measuring site in Zagreb air between 2001 and 2004, and seasonal differences in PAH mass concentrations in PM(10) samples collected from 21 March 2003 to 20 March 2004. Twenty-four hour samples were taken in the northern residential part of Zagreb using a low-volume (50 m(3)) sampler and glass or quartz filters. The analysis was performed using a high-performance liquid chromatograph (HPLC) and fluorescence detector with changeable excitation and emission wavelength. The annual average mass concentrations over the four-year measuring period for BaP ranged from 1.17 ng/m(3) in 2004 to 1.87 ng/m(3) in 2003 and were below the limit value (2 ng/m(3)) set by the Ordinance on Recommended and Limit Air Quality Values in Croatia. The highest concentrations of all PAHs measured in PM(10) samples collected from 21 March 2003 to 20 March 2004 were found in the winter and the lowest in the summer. Winter average of BaP was 2.94 ng/m(3) and summer average 0.12 ng/m(3). Autumn average was 2.76 ng/m(3) and was very similar to winter concentrations. Spring average of 0.58 ng/m(3) was higher than the summer average (0.12 ng/m(3)). Mass concentrations of all measured PAHs were much higher in the autumn than in the spring. Although annual averages for BaP did not exceed the limit value, autumn and winter BaP mass concentrations did, which calls for measures for reducing PAH emissions in the autumn and winter.  相似文献   
87.
Exploitation of certain resources within a protected area on a sustainable basis could contribute to higher living standards of rural people, particularly those in poor countries, and decrease conflicts between these populations and park authorities. This article presents data from a case study of Kopaonik National Park (NP), Serbia, which is a park with natural resources, most notably bilberries, which have always been relied on by local people. Vaccinium myrtillus traditionally has been collected for decades in Kopaonik NP and used by local people. However, little is known about the socioeconomic and ecological relations that affect the collection and use of this species. The aim of the present study was to understand how local people collect bilberries in Kopaonik NP and what their attitudes toward the park are. Household questionnaire data were used to examine how local people collect bilberries and how to improve the relations between local people and NP authorities. The survey questionnaire included 52 households from 7 local communities, and we applied a purposive sampling strategy. In addition, expert interviews were conducted, and from these data we obtained a broader understanding of the relation between local people and NP authorities. The results indicate that in Kopaonik NP, there is a conflict between pickers and NP authorities. Sustainable management should be directed toward the protection of bilberries. Education of local people is a key element in the sustainable collection and protection of natural resources.  相似文献   
88.
Conservation of biodiversity in managed forest landscapes needs to be complemented with new approaches given the threat from rapid climate change. Most frameworks for adaptation of biodiversity conservation to climate change include two major strategies. The first is the resistance strategy, which focuses on actions to increase the capacity of species and communities to resist change. The second is the transformation strategy and includes actions that ease the transformation of communities to a set of species that are well adapted to the novel environmental conditions. We suggest a number of concrete actions policy makers and managers can take. Under the resistance strategy, five tools are introduced, including: identifying and protecting forest climate refugia with cold-favored species; reducing the effects of drought by protecting the hydrological network; and actively removing competitors when they threaten cold-favored species. Under the transformation strategy, we suggest three tools, including: enhancing conditions for forest species favored by the new climate, but currently disfavored by forest management, by planting them at suitable sites outside their main range; and increasing connectivity across the landscape to enhance the expansion of warm-favored species to sites that have become suitable. Finally, we suggest applying a landscape perspective and simultaneously managing for both retreating and expanding species. The two different strategies (resistance and transformation) should be seen as complementary ways to maintain a rich biodiversity in future forest ecosystems.  相似文献   
89.
Environmental Chemistry Letters - Plastic pollution in water ecosystems is threatening the survival of wildlife. In particular, microplastics may be encapsulated into calcium carbonate, a crucial...  相似文献   
90.
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