11 research outputs found

    Advances in research on the use of biochar in soil for remediation: a review

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    Purpose: Soil contamination mainly from human activities remains a major environmental problem in the contemporary world. Significant work has been undertaken to position biochar as a readily-available material useful for the management of contaminants in various environmental media notably soil. Here, we review the increasing research on the use of biochar in soil for the remediation of some organic and inorganic contaminants.  Materials and methods: Bibliometric analysis was carried out within the past 10 years to determine the increasing trend in research related to biochar in soil for contaminant remediation. Five exemplar contaminants were reviewed in both laboratory and field-based studies. These included two inorganic (i.e., As and Pb) and three organic classes (i.e., sulfamethoxazole, atrazine, and PAHs). The contaminants were selected based on bibliometric data and as representatives of their various contaminant classes. For example, As and Pb are potentially toxic elements (anionic and cationic, respectively), while sulfamethoxazole, atrazine, and PAHs represent antibiotics, herbicides, and hydrocarbons, respectively.  Results and discussion: The interaction between biochar and contaminants in soil is largely driven by biochar precursor material and pyrolysis temperature as well as some characteristics of the contaminants such as octanol-water partition coefficient (KOW) and polarity. The structural and chemical characteristics of biochar in turn determine the major sorption mechanisms and define biochar’s suitability for contaminant sorption. Based on the reviewed literature, a soil treatment plan is suggested to guide the application of biochar in various soil types (paddy soils, brownfield, and mine soils) at different pH levels (4–5.5) and contaminant concentrations ( 50 mg kg−1).  Conclusions: Research on biochar has grown over the years with significant focus on its properties, and how these affect biochar’s ability to immobilize organic and inorganic contaminants in soil. Few of these studies have been field-based. More studies with greater focus on field-based soil remediation are therefore required to fully understand the behavior of biochar under natural circumstances. Other recommendations are made aimed at stimulating future research in areas where significant knowledge gaps exist

    EQ-5D in Central and Eastern Europe : 2000-2015

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    Objective: Cost per quality-adjusted life year data are required for reimbursement decisions in many Central and Eastern European (CEE) countries. EQ-5D is by far the most commonly used instrument to generate utility values in CEE. This study aims to systematically review the literature on EQ-5D from eight CEE countries. Methods: An electronic database search was performed up to July 1, 2015 to identify original EQ-5D studies from the countries of interest. We analysed the use of EQ-5D with respect to clinical areas, methodological rigor, population norms and value sets. Results: We identified 143 studies providing 152 country-specific results with a total sample size of 81,619: Austria (n=11), Bulgaria (n=6), Czech Republic (n=18), Hungary (n=47), Poland (n=51), Romania (n=2), Slovakia (n=3) and Slovenia (n=14). Cardiovascular (20%), neurologic (16%), musculoskeletal (15%) and endocrine/nutritional/metabolic diseases (14%) were the most frequently studied clinical areas. Overall 112 (78%) of the studies reported EQ VAS results and 86 (60%) EQ-5D index scores, of which 27 (31%) did not specify the applied tariff. Hungary, Poland and Slovenia have population norms. Poland and Slovenia also have a national value set. Conclusions: Increasing use of EQ-5D is observed throughout CEE. The spread of health technology assessment activities in countries seems to be reflected in the number of EQ-5D studies. However, improvement in informed use and methodological quality of reporting is needed. In jurisdictions where no national value set is available, in order to ensure comparability we recommend to apply the most frequently used UK tariff. Regional collaboration between CEE countries should be strengthened

    Staminodial Nectary Structure in Two Pulsatilla (L.) Species

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    In plants belonging to the Ranunculaceae the floral nectaries may differ in origin, location in the flower, shape and structure. In many cases they are defined as modified tepals or modified stamens. The nectary organs in this family are frequently termed "honey leaves," and staminodial origin is attributed to them. Gynopleural and receptacular nectaries are rarely found in Ranunculaceae. To date there are no reports on the structure of the nectary organs in plants of the genus Pulsatilla. We used light and scanning electron microscopy to study the location and structure of the nectaries in Pulsatilla slavica and P. vulgaris flowers. The staminodial nectaries were found to be nectar-secreting organs. The number of stamens per flower (102-398) increases with plant age. The share of staminodes is 12–15%. The staminodes are composed of a filament and a modified head. They are green due to the presence of chloroplasts in the epidermal and parenchymal cells. The parenchymal cells are in a loose arrangement. Stomata (3–20), through which nectar exudation occurred, were found only in the abaxial epidermis of the staminode head. The stomata are evenly distributed and have well-developed outer cuticular ledges. Some of them are immature during nectar secretion, with their pores covered by a layer of cuticle. During the activity of the nectariferous organs in the flowers, primary (on the staminode surface) and secondary nectar (at the base of tepals) are presented. The staminodes of the two Pulsatilla species show similar structural features and have similar shares in the androecium

    Floral resources provided by the new energy crop, Silphium perfoliatum

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    Flower-visiting insects are important crop pollinators, but their populations in agricultural landscapes are declining. One reason is the decreasing quantity and quality of floral resources. Deterioration of the situation caused by an increasing production of energy crops like maize, a pollen-only resource, may be mitigated by alternative crops such as Silphium perfoliatum L., which produces pollen and nectar over a long-lasting flowering period (July–September). The aim of this study was to assess the floral resources of S. perfoliatum. We calculated pollen grains and nectar sugar mass per inflorescence as well as inflorescences per plant using experimental plots and commercial fields in Germany. In addition, we analyzed free and protein-bound amino acids in pollen as well as sugars and free amino acids in nectar. The amount of pollen and nectar sugar per inflorescence decreased with increasing stem branching. The production of pollen and nectar sugar, however, was greatest in the second half of August due to the high number of inflorescences per plant at that stage. About half of the farmers harvested S. perfoliatum before the end of flowering to gain higher methane yields. With an early harvest around the beginning of September about one sixth of total pollen and one fifth of total nectar sugar production were lost to pollinators. Pollen and nectar showed high amounts of certain essential amino acids, particularly histidine, but total amino acids were low in concentration. Hence, S. perfoliatum should be complemented with different bee fodder plants to ensure a well-balanced diet
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