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31.
32.
Regionalism has commonly been expected to dissolve as a consequence of the administrative regional penetration of the centralized modern state and the homogenizing forces associated with modernization. This mode of reasoning has reappeared recently among authors who see globalization as a universal force that will eradicate regional economic inequalities, local identities and regional political mobilization. Contrary to these expectations, regional autonomy movements continue to play a central political role within many states. Consequently, it remains an important analytical challenge to understand the construction and politicization of regional interests. Against this background, the article presents a critical interpretation and contextual analysis of Tamil separatism in Sri Lanka. It is argued that studies of nationalist movements should seek inspiration in the contemporary dialog between three main perspectives on social movements (theories of new social movements, resource mobilization theories, and theories of collective identity) and a corresponding three‐dimensional understanding of place (location, locale, and sense of place). The paper shows how nationalist mobilization cannot be reduced to essentialist notions of primordial nations, territorial nation‐states, or internal colonialism, but instead should be understood as the outcome of cultural and political practices by a multitude of actors, operating in time‐ and place‐specific contexts.  相似文献   
33.
Head and neck squamous cell carcinoma (HNSCC) is a common, morbid, and frequently lethal malignancy. To uncover its mutational spectrum, we analyzed whole-exome sequencing data from 74 tumor-normal pairs. The majority exhibited a mutational profile consistent with tobacco exposure; human papillomavirus was detectable by sequencing DNA from infected tumors. In addition to identifying previously known HNSCC genes (TP53, CDKN2A, PTEN, PIK3CA, and HRAS), our analysis revealed many genes not previously implicated in this malignancy. At least 30% of cases harbored mutations in genes that regulate squamous differentiation (for example, NOTCH1, IRF6, and TP63), implicating its dysregulation as a major driver of HNSCC carcinogenesis. More generally, the results indicate the ability of large-scale sequencing to reveal fundamental tumorigenic mechanisms.  相似文献   
34.
During the latter decades extensive fish kills have been observed in the mountainous areas of southernmost Norway. These kills have been attributed to the increased acidity of the river-water. The increased acidity is generally assumed to be caused by acid precipitation. However, the relationship between precipitation and runoff quality is very complex. The present paper is concerned with the relationship between chemical composition of simulated rain and that of runoff from bare granitic rock, partly covered by lichens. When supplying simulated rain with a pH value of approximately 5 the very first runoff had pH values between 4.1 and 4.3. However, the pH in the runoff increased rapidly and leveled out at values between 4.6 and 4.7. When supplying simulated rain with pH approximately 3.5, the pH in the first runoff varied between 3.8 and 3.6. The pH then gradually decreased to the same values as those in the simulated rain. Runoff from ‘rain’ with pH 4.3, obtained the same pH value as that of the ‘rain’. The pH of the runoff was dependent not only on the rain acidity, but also on its content of neutral salts.  相似文献   
35.
A computerised system for non-invasive monitoring of heart and ventilation rates and the time intervals between heart beats and between breaths was developed and used to investigate cardio-respiratory changes in rainbow trout exposed to hypoxia and to combined hypoxia and hypercapnia. Upon exposure to hypoxia and hypoxia-hypercapnia the arterial O2 tension decreased from about 90 mmHg to about 30 mmHg. Acid-base changes were small in hypoxia whereas exposure to combined hypoxia-hypercapnia caused a large extracellular respiratory acidosis. This acidosis was completely compensated within 24h by accumulation of bicarbonate in plasma to concentrations twice the normoxic values. The ventilation rate was increased to higher values in hypoxic-hypercapnic trout than in hypoxic trout. In contrast to previous reports, the heart rate increased in hypoxia. On top of the tachycardia response to hypoxia, the heart rate was governed by circadian rhythms, with higher heart rates during the day than during the night. The time interval between heart beats varied considerably in normoxic fish. Hypoxia strongly reduced this variability, which may originate in a reduced cholinergic tone to the heart. The width of the frequency distribution of the time intervals between breaths was not affected by hypoxia. The degree of cardio-respiratory synchronization was low in both normoxic and in hypoxic and hypoxic-hypercapnic trout.  相似文献   
36.
To ensure high yield and quality in organic vegetable production, crops often require additional fertilizer applied during the season. Due to the risk of contamination of edible plant products from slurry, plant‐based fertilizers may be used as an alternative. The purpose of our work was to develop mobile green manures with specific high nutrient concentrations (e.g., nitrogen [N], sulfur [S], and phosphorus [P]) that are released quickly after soil incorporation and that are easy to handle during storage and application. To distinguish from traditional green manures that are grown to improve soil fertility, the term “mobile green manures” is used for green‐manure crops that are harvested in one field and then moved as a whole and used as fertilizer in other fields. To further investigate mobile‐green‐manure crops for use as efficient fertilizers, pot and field experiments were conducted with cauliflower (Brassica oleracea botrytis) and kale (Brassica oleracea sabellica) supplied with organic matter consisting of a wide range of plant species with varying nutrient concentrations. Further, field experiments were conducted with leek (Allium porrum) and celery (Apium graveolens dulce) supplied with increasing amounts of organic matter consisting of fresh, ensiled, or dried green manures. Results show that garden sorrel (Rumex acetosa), dyer's woad (Isatis tinctoria), and fodder radish (Raphanus sativus) harvested with a high leaf‐to‐stem ratio resulted in high P concentration, and cruciferous crops in high S concentration. Dyer's woad, salad burnet (Sanguisorba minor), and stinging nettle (Urtica dioica) showed high boron (B) concentration, whereas species such as dandelion (Taraxacum officinale), chicory (Cichorium intybus), and garden sorrel showed high potassium (K) concentration. Green manures with high P and S concentrations increased the nutrient uptake and yield of pot‐grown cauliflower and kale. Field experiments showed that the production of cauliflower and kale decreased when the carbon‐to‐nitrogen (C : N) ratio of applied green manure increased. In kale, for example, application of 160 kg N ha–1 in early harvested lucerne (Medicago sativa) with a C : N ratio of 10 resulted in the highest kale production whereas application of an equal amount of N in late harvested lucerne with a C : N ratio of 20 produced 34% less. Differences in vegetable production were not due to the amount of N applied, but to the N availability. Field experiments with fresh, ensiled, or dry green manure applied to leek and celery showed that the C : N ratio has to be low to get a fast response. Further, these field experiments demonstrate the importance of green manures, which can be stored and are easy to handle during transport, crop application, and soil incorporation. It is concluded that it is possible to produce green manures with high concentrations of S, P, K, and B, and low C : N ratios and that these properties have a great impact on the value of the green manure for vegetable production.  相似文献   
37.
Since the early 1990s, Ulaanbaatar, the capital of Mongolia, has experienced rapid rural to urban migration and population growth resulting in the growth in informal settlements across the city. The informal settlements are known as ‘ger’ districts. In response to these pressures, since the 1990s, the central government has adopted a programme of land reform and metropolitan planning. These new reforms take place in the context of a unique, post‐socialist political, economic and institutional context. The land reform process has attempted to privatise land ownership, which has traditionally resided with the state. The privatisation process was initiated under the new Constitution of Mongolia, which initiated reforms in all sectors of social and economic development, and since 2003, targeted land reform in ger districts. Running parallel, a series of urban land‐use planning schemes have been introduced to frame the development of Ulaanbaatar in the context of an emerging market economy. Although master plans for urban development have been established since the 1950s, urban land‐use planning is a new concept in this emerging market economy. The aim of this paper is to trace the rationales and challenges of implementing master plans and land privatisation processes in Ulaanbaatar. Drawing on interviews with city, national and local government officials conducted in 2009, the paper focuses on the implications of these reforms for both the government and the residents of ger districts.  相似文献   
38.
Oxygen microsensors were used to determine oxygen profiles in situ from the top to the bottom layer of the growing medium for potted plants of Rosa sp. ‘Dior’. The growing medium was peat- based and compacted uniformly to 3 different bulk densities of 0.14, 0.18 and 0.23 g cm−3 (0, 20 and 40% compacted, respectively). The water distribution in the pot was determined as water content (g cm−3) in the top, middle and bottom layers of the peat. Oxygen content was also determined after a standard subirrigation cycle and after excessive irrigation where the bottom of the pots were left waterlogged for 24 h. Measurements were carried out at 5.5 weeks during the production phase and at 12 weeks at the end of the production. The results showed that with increasing compaction and density, more water was transported to the upper layers of the pot. After a standard irrigation cycle there was no effect of the level of medium compaction on the oxygen distribution, whereas after excessive irrigation, the oxygen contents at the bottom of the pots were strongly reduced and the level of compaction significantly affected oxygen availability. The most compacted medium had the lowest oxygen content at 5.5 weeks, with anoxic conditions in the bottom 30 mm. Plant quality measured as fresh weight, dry weight, height and number of shoots with flowers and buds was not affected by the different levels of compaction. The use of oxygen microsensors provided a new insight into the spatial and temporal distribution of oxygen in growing media and how this was affected by the physical characteristics of the growing media.  相似文献   
39.
Fusarium culmorum and F. equiseti were characterized with regard to production of trichothecenes and other secondary metabolites. Results following growth on laboratory media are interpreted with the aim of increasing the understanding of fungal metabolism in the field environment. While trichothecene production was detected for 94 of 102 F. culmorum isolates, only 8 of 57 F. equiseti isolates were positive. Profiles of secondary metabolites were compared by following growth on yeast extract sucrose agar (YES), potato sucrose agar (PSA), and an agar medium, prepared from soil organic matter (SOM), which was included to simulate growth conditions in soil. SOM supported the production of chrysogine by F. culmorum. The two species utilized the media differently. F. culmorumproduced zearalenone (ZEA) on YES, whereas some F. equiseti isolates produced ZEA on PSA. Other F. equiseti isolates produced equisetin. These differences may reflect that F. culmorum depends on a pathogenic life style while F. equiseti has a more saprotrophic mode of existence.  相似文献   
40.
Abstract

The effects of catch crops on the nitrogen nutrition of a succeeding carrot crop were investigated. An attempt was made to distinguish the effects of growth and nitrogen uptake by the catch crop from the effect of mineralization of its residues. It was found that growth and nitrogen uptake by catch crops could reduce the nitrogen supply to the succeeding carrot crop through pre-emptive competition, whereas mineralization of nitrogen from the catch crop residues increased the nitrogen supply to the carrot crop. Nitrogen uptake by the carrots was thus highest where catch crop residues were incorporated on plots where no catch crop had been grown. The effect of the mineralization was found mainly to influence topsoil mineral nitrogen contents and the early nitrogen uptake by carrots, whereas the effect of pre-emptive competition was to reduce subsoil mineral nitrogen content and the nitrogen uptake by carrots late in the growing season. The apparent recovery of catch crop nitrogen by carrots was between 8 and 33%.  相似文献   
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