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181.
Light (LM) and transmission electron (TEM) microscopy were used to study previously specified ozone symptoms in the foliage of Norway spruce. The three youngest green needle generations from twenty mature trees in two stands on sites of different soil fertility at Asa, southern Sweden, were sampled in 1999. The critical dose of ozone, expressed as AOT40, was 6,362 ppb.h. LM showed ozone-specific symptoms: decreased chloroplast size with electron dense stroma advancing gradually from the outer to the inner cell layers, being most severe in the needle side facing the sky. The symptoms were expressed as ozone syndrome indices at the needle generation, tree and stand levels. The index had higher values at the low fertility site. TEM was used to confirm the LM results. The study shows that LM can be used for diagnosis of the impact of ozone on conifers in the field.  相似文献   
182.
In order to explain some of the possible origins of an odor episode which took place in a drinking water supply in the region of Paris (France), the impact of disinfection on the formation of odorous by-products was investigated. We have previously established that very odorous and stable chloroaldimines are formed during amino acid chlorination in conditions relevant to those of drinking water treatment. As chlorination is preceded by a UV-irradiation step, we examined here the impact of this irradiation on the formation of chloroaldimines. Irradiation (30 m W cm(-2)) of various amino acids (glycine, valine, phenylalanine) and peptides (Phe-Gly-Gly-Phe, Phe-Ala) led to a degradation of the compounds but it was negligible at the doses applied in drinking water supplies. As peptides were concerned, contrary to what we previously expected, the degradation did not involve the peptidic bond breaking: irradiation induces therefore no increase in the quantity of free amino acids, precursors of odorous chloroaldimines. However chlorination of peptides (Phe-Ala-Ala-Val, Phe-Gly-Gly-Phe and Ala-Phe) showed that chloroaldimines are also probably formed during combined amino acids chlorination.  相似文献   
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The October 2005 earthquake in northern Pakistan severely affected the livelihoods of 1.5 million people. With the destruction of material assets and communications infrastructure, the quake had a devastating impact on people's way of life in this remote mountainous region. This paper explores livelihood revival interventions undertaken during the earthquake response, and considers how differentiated livelihood outcomes were achieved. In addressing this objective the paper examines livelihood rehabilitation schemes in terms of structural aspects, working strategies, key factors, strengths of interventions and the role of human agency in influencing livelihood trajectories of quake‐affected communities. Primary data for this study was gathered in northern Pakistan between October 2008 and January 2009. The study identifies structural shortcomings and strengths of the programmes attempting to revive the livelihoods of poor and vulnerable households. It identifies how households in two villages made the most of opportunities to improve their lives and move towards favourable outcomes.  相似文献   
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This study describes an outbreak investigation of 14 hepatitis A cases in the Netherlands. The hepatitis A virus (HAV) genotype IB sequences in cases were highly similar (459/460 nt). The origin of strains could be narrowed to Bulgaria based on information from EPIS-FWD. As an association with consumption of soft fruit was suspected, a case–control study was initiated using a questionnaire and a list of pictures of soft fruit available at the supermarket chain involved. Twelve out of 13 cases consumed a specific frozen raspberry/blueberry product shown on the list (OR 46.0, 95% CI 5.0–27). In multivariable regression analysis this product was the only risk factor (aOR 26.6, 95% CI 2.0–263). Laboratory analyses could not demonstrate HAV-RNA in batches that had been on the market in the incubation period of patients. Trace back of frozen fruit showed that raspberries had been traded by a producer in Bulgaria. After withdrawal of the product from the supermarket no new cases were reported. Use of advertisement pictures of consumed food was helpful in this investigation. Suspicion of the source was strengthened by data from molecular typing and food trace back activities, underlining the importance of good (inter)national cooperation between public health and food safety organisations.  相似文献   
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