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Abstract

The aim of the study was to evaluate the degree of pollution of bottom sediments from small water reservoirs with heavy metals on the basis of geochemical criteria: the enrichment factor and the geo-accumulation index. The investigations concerned sediment from eight small water reservoirs located in the Kielce Highland. Selected heavy metals, including cadmium, chromium, copper, lead and zinc, were determined using inductively coupled plasma-atomic emission spectrometry method. Additionally, particle size distribution and the content of organic matter expressed as loss of ignition were designated. The concentration of heavy metals in sediments was characterized by a great variety. The sediments of Morawica and Rejów show very high and extremely high enrichment in Cr, Zn, Pb and Cd. The values of EF>20 indicate also an extremely high enrichment in Cd of sediments in Mostki. In addition, over 50% of the samples of sediment from Suchedniów, Kaniów, Mostki and Jaśle reservoirs (the value of EF for Cr exceeded 5) indicate a moderately high enrichment of this element. Results of the analysis of the Igeo values indicate that the tested sediments are characterized by moderately high (2<Igeo<3) or high (3<Igeo<4) pollution. The differences in individual enrichment factor and geoaccumulation index values may result in the nature of heavy metals, their pollution loads, as well as speciation forms of trace elements occurrence in sediment-water complex. These findings indicate that the integration of geochemical methods is necessary for an appropriate ecological risk assessment of heavy metals in bottom sediments.

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Authors and Affiliations

Aleksandra Sałata
Łukasz Z. Bąk
Krzysztof Chmielowski
Anna Rabajczyk
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Abstract

Since the 1980s, seaport cities have been characterized by the spatiotemporal concurrence of highly modern terminals away from the city and derelict and/or sub-optimally used inner city harbours and waterfront sites. The post-Fordist city disintegrated into a polycentric fragmented structure with aggravated social confl icts between older residential areas of dockers and requirements for modern expensive waterfront condominiums. The cranes of the shipbuilders’ yards, which used to be a characteristic feature of the city silhouette and a symbol for dynamic port economies, have been dismantled, the land left derelict and contaminated. The formerly close functional and spatial relationship of port and city was relaxed from the end of the 1960s onwards and off ered opportunities for transformations. In this article different approaches for redevelopment und revitalization are discussed.

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Authors and Affiliations

Dirk Schubert
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Abstract

Fall armyworm ( Spodoptera frugiperda) (FAW) is an important invasive pest of maize. The young FAW larva disrupts the photosynthetic system by feeding on the leaves. The older caterpillar interferes with pollination and fertilization processes, destroying the tassel and silks, or it bores into the maize cob, reducing harvest quality and predisposing the cob to secondary infections. The infested plant responds by channeling or converting the primary metabolites into secondary metabolites for plant defense, further reducing crop yield. The devastating feeding effect on maize becomes even more severe when maize plants are exposed to prolonged drought, during which the production of secondary metabolites is optimum. These secondary metabolites are food for herbivorous insects like the fall armyworm. Naturally, plants possess several adaptive features which enable them to cope and survive herbivorous insect attacks without compensating yield for plant defense. Such features include: thickening of the leaf cuticle of the epidermal cell walls, production of certain allelochemicals, defense proteins and the toxic chemical compound, favone glycoside (silk maysin). This review attempts to critically appraise the physiological implications of fall armyworm damage on developmental processes and maize yield. Understanding the mechanisms of various adaptive traits that confer resistance to maize against herbivorous insect damage would assist greatly in crop improvement processes.
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Authors and Affiliations

Folake Bosede Anjorin
1
Oluwaseyi Oluwakemi Odeyemi
1
Olufolake Adenike Akinbode
1
Kehinde Tolulope Kareem
1

  1. Institute of Agricultural Research and Training, Obafemi Awolowo University, Ibadan, Nigeria

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