Determination of 28 Elements in Aquatic Moss Fontinalis Antipyretica Hedw. and Water from the Upper Reaches of the River Nysa (CZ,D), by ICP-MS,ICP-OES and AAS

The concentrations of 28 elements in samples of the bryophyte F. antipyretica Hedw collected from various sites on the upper reaches of the River Nysa and its main tributaries were determined. These results were compared with similar analyses of water samples collected at the same sites. So, it was possible to determine the elemental composition of the water both directly and indirectly, using a bioindicator organism. Analyses were carried out using different instrumental techniques (ICP-MS, ICP-OES, AAS), some elements being analysed by both ICP-MS and ICP-OES. Functional regression analysis showed that for some of these elements, namely Al, Ba, Fe, Sr and Ti in moss, and Ba, Ca and Zn in water samples, there was no significant difference (p < 0.05) in the concentrations determined by both techniques. The coefficients of correlation moss/water for each element were calculated, but they were in general low. However the coefficients of correlation between different elements were in general good. Finally, the elemental concentrations in the aquatic moss were also used to assess the level of contamination in the area of study, through the calculation of CF (Contamination Factor) values.     

Transformation of Eutypa dieback and esca disease pathogen toxins by antagonistic fungal strains reveals a second detoxification pathway not present in Vitis vinifera

Eutypine, 4-hydroxybenzaldehyde, and 3-phenyllactic acid are some of the phytotoxins produced by the pathogens causing Eutypa dieback and esca disease, two trunk diseases of grapevine (Vitis vinifera). Known biocontrol agents such as Fusarium lateritium and Trichoderma sp. were screened for their ability to consume these toxins. Transformation time courses were performed, and an high-performance liquid chromatography-based method was developed to analyze toxin metabolism and to identify and quantify the converted products. The results show that the aldehyde function of eutypine was reduced to eutypinol, as by V. vinifera cv. Merlot, the cultivar tolerant to Eutypa dieback. We revealed a supplementary detoxification pathway, not known in Merlot, where the aldehyde function was oxidized to eutypinic acid. Moreover, some strains tested could further metabolize the transformation products. Every strain tested could transform 4-hydroxybenzaldehyde to the corresponding alcohol and acid, and these intermediates disappeared totally at the end of the time courses. When biological assays on cells of V. vinifera cv. Chasselas were carried out, the transformation products exhibited a lower toxicity than the toxins. The possibility of selecting new biocontrol agents against trunk diseases of grapevine based on microbial detoxification is discussed.     

Biology of the gametes of some teleost species

Our knowledge of the biology of fish gametes is still limited. Up to now research was short-term, aiming at solving practical questions connected with gamete storage and artificial insemination. More information on gamete biology is now available and has been summarized in this minireview.In vivo storage of gametes in the genital tract after ovulation or spermiation may be influenced by the osmotic environmentvia changes in the ionic composition of the companion fluid. There is great inter-individual variability in gamete survival bothin vivo andin vitro. Mechanisms involved in the initiation of trout sperm motility have been analysed; after dilution in water or NaCl solution (125 mM) at pH > 7, Ca⁺⁺ entry due to changes in membrane potential have been observed. The involvement of cAMP and protein phosphorylation has been reported. The morphological, physical and biochemical changes in eggs that have been studied after fertilization and the corticol reaction lead to a better understanding of the mechanisms of polyspermy blockage.     

The feeding ecology of earthworms – A review

Current knowledge of earthworm feeding ecology is reviewed, with particular reference to food selection, ingestion, digestion and assimilation, and the use of novel techniques to advance understanding of the functional significance of these processes.

Traditional research methods including direct observation of feeding behaviour, gut content analysis, choice tests, and litter bags have provided a wealth of information on earthworm feeding. However, there is a lack of the mechanistic, quantitative information required to characterise adequately their functional role in soil ecosystem processes such as soil C sequestration and loss, decomposition of organic residues, the maintenance of soil structure and trophic interactions with plants and microorganisms.

Stable isotope ratio analysis of light elements (C, N, and S) offers a powerful research tool to reveal and quantify trophic relationships of earthworms in soil food webs, while molecular techniques can further enhance understanding of the interactions between earthworms and microorganisms and their functional significance.     

如何在花卉产销中增加产品附加值

超市的出路现在许多人都在满怀希望地关注着花卉零售连锁产业的发展,这个市场越来越大,参与的人们都希望能分得一杯羹。但是英国的经营模式告诉我们,在花卉贸易中,连锁经营中供应商的选择相当重要。     

Livelihoods and agro-ecological gradients: A meso-level analysis in the Indo-Gangetic Plains, India

Rice-wheat systems in the Indo-Gangetic Plains (IGP) have long exemplified South Asia’s agricultural transformation through the Green Revolution. The same systems now also typify the post-Green Revolution stagnation and equity challenges, despite receiving considerable attention from the research and development (R&D) community. The apparent homogeneity of vast irrigated plains masks significant diversity in assets, livelihood strategies and livelihood outcomes. The paper analyzes the rural livelihoods and underlying agro-ecological gradients in the IGP drawing on village surveys and secondary data as characterization tools. The contribution of the paper is twofold: (i) new knowledge of the socio-economic circumstances in farming communities across the Indian IGP to enhance the effectiveness and efficiency of R&D interventions and particularly poverty alleviation; and (ii) an illustration of a novel approach to operationalize livelihood analysis at the meso-level so as to address spatial scale issues and link micro-level contextual realities across a vast geographical area. The agricultural R&D community needs to incorporate this socio-economic diversity more proactively into its R&D agenda if it is to succeed in sustaining productivity gains, improving rural livelihoods equitably, and securing environmental sustainability in this important eco-region.