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1.
J Environ Manage ; 163: 146-54, 2015 Nov 01.
Article in English | MEDLINE | ID: mdl-26311087

ABSTRACT

Overuse of nitrogen (N) fertilizer constitutes the major issue of current crop production in China, exerting a substantial effect on global warming through massive emission of greenhouse gas (GHG). Despite the ongoing effort, which includes the promotion of technologically sophisticated N management schemes, farmers' N rates maintain at excessive rates. Therefore the current study tests three simple and easily to apply N fertilizer recommendation strategies, which could be implemented on large scale through the existing agricultural advisory system of China, at comparatively low cost. Building on a detailed crop production dataset of 65 winter wheat (WW) and summer maize (SM) producing farm households of the North China Plain, scenario analysis is applied. The effects of the three N strategies under constant and changing yield levels on product carbon footprint (PCF) and gross margin (GM) are determined for the production condition of every individual farm household. The N fixed rate strategy realized the highest improvement potential in PCF and GM in WW; while the N coefficient strategy performed best in SM. The analysis furthermore revealed that improved N management has a significant positive effect on PCF, but only a marginal and insignificant effect on GM. On the other side, a potential 10% yield loss would have only a marginal effect on PCF, but a detrimental effect on farmers' income. With farmers currently applying excessive N rates as "cheap insurance" against potential N limitation, it will be of vital importance to avoid any yield reductions (caused by N limitation) and respective severe financial losses, when promoting and implementing advanced fertilization strategies. To achieve this, it is furthermore recommended to increase the price of fertilizer, improve the agricultural extensions system, and recognize farmers' fertilizer related decision-making processes as key research areas.


Subject(s)
Agriculture/methods , Fertilizers , Greenhouse Effect , Nitrogen , Triticum/growth & development , Zea mays/growth & development , Carbon Footprint , China , Crops, Agricultural/growth & development , Fertilizers/analysis , Global Warming , Nitrogen/analysis
2.
Cancer Genet Cytogenet ; 142(2): 107-14, 2003 Apr 15.
Article in English | MEDLINE | ID: mdl-12699885

ABSTRACT

Acquired loss of material from chromosome 5 in bone marrow cells is common in myelodysplastic syndromes (MDS) and acute myelocytic leukemia (AML). In this study, we have applied fluorescence in situ hybridization (FISH) analyses with probes for the three regions 5p15.2, 5q31, 5q33-q34, and whole chromosome 5 painting probes (WCP 5) to investigate what further information could be gained regarding the cytogenetic abnormalities of chromosome 5 in 35 patients with MDS or AML. With FISH, a del(5q) was found in all patients except for two. Translocations of material from chromosome 5 were found in 10 patients. Among 16 patients with clones of monosomy 5 seen by cytogenetics, 14 had deletions or translocations. Different breakpoints on chromosome 5 were observed. In conclusion, the extended FISH analyses yielded additional information about chromosome 5 abnormalities in 60% of the patients. Of interest is the finding of a high proportion of translocations and that monosomy 5 occurs less often than is generally believed.


Subject(s)
Chromosome Deletion , Chromosomes, Human, Pair 5/genetics , Leukemia, Myeloid, Acute/genetics , Monosomy/genetics , Myelodysplastic Syndromes/genetics , Translocation, Genetic/genetics , Aged , Aged, 80 and over , Cytogenetic Analysis , Female , Genetic Predisposition to Disease , Humans , In Situ Hybridization, Fluorescence , Male , Middle Aged
3.
Oecologia ; 85(2): 226-232, 1990 Dec.
Article in English | MEDLINE | ID: mdl-28312559

ABSTRACT

The epidermal uptake of Pb, Cd, and the essential element Zn by tubificid worms was investigated. The animals were starved and contaminated via the water column at 4°C and 25°C. Atomic absorption spectroscopy (AAS), energy-dispersive X-ray microanalysis (EDX), laser induced mass analysis (LAMMA), electron microscopy, and the sulfide-silver method at the electron microscopical level were used. The sulfidesilver method revealed many reaction products indicating heavy metals in membrane-limited lysosomal structures in epidermal cells of contaminated Limnodrilus udekemianus. In these lysosomes, which were particularly abundant in the epidermis of the hind end, Pb, Cd, and Zn were detected by LAMMA and EDX analysis. Beside this distinct occurrence of the three elements a uniform pattern of reaction products was found in epidermal cells after contamination with Cd and Zn, but not after treatment with Pb. As shown by atomic absorption spectroscopy, Cd was the most enriched element at 25°C, followed by Pb and Zn. Simultaneous application of Zn reduced the uptake of Cd, whereas the uptake of Pb was increased. At 4° C uptake of Pb and Cd was slower than at 25° C, while Zn uptake was blocked completely. This shows that heavy metal uptake can be strongly dependent on environmental conditions, which has to be taken into account if animals are used as monitor organisms for heavy metal pollution in the environment.

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