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441.
In this paper we analyse how risk factors in highly industrialised agriculture are connected to animal neglect. With Danish agriculture as a case study, we use two types of data. First, we use register data from Statistics Denmark to map how risk factors such as farmers’ financial and social troubles are connected to convictions of neglect. Second, we analyse narratives where interviewed farmers, involved in cases of neglect, describe how they themselves experienced the incidents. We find that while livestock farmers in general have a low risk of animal neglect problems, a small percentage of them face severe financial difficulties, divorce and psychiatric problems, which are connected to an increased risk of being convicted for the neglect of farm animals. The narratives bring forward themes of pressure related to financial trouble, technological break down, family problems, stress and a growing concern among the farmers towards the governmental control in farm animal production. We discuss how these factors can be used to identify and help farmers with a high risk of being convicted of livestock neglect.  相似文献   
442.
Cutting the cake: Supporting environmental fund allocation decisions   总被引:1,自引:0,他引:1  
This paper describes a decision support model for allocating financial resources amongst multiple user groups in environmental management problems. The model is based on the multiple criteria analysis (MCA) method of compromise programming. It was used to inform the allocation of Natural Heritage Trust funds across 14 regions in Queensland, Australia. The model targets funding to those regions with greater natural resource management needs. Need is determined by 19 weighted criteria relating to natural resource assets and threats. The model was accepted by the Australian Government, Queensland Government and regional groups as an appropriate means for allocating program funds; first in 2005 and then again, with improvements, in 2007. This paper shows that an MCA model can improve the transparency, auditability and acceptance of allocation decisions which would otherwise be heavily politicised.  相似文献   
443.
Biology is searching for a paradigm of life and is proceeding from an inductive, empirical to a deductive, formal science. All life phenomena result from the efficacy of a principle, i.e., systemic information, which is not reducible to physics and chemistry. Systemic information, together with genetic information engraved on macromolecules and matter described by physics and chemistry, represents the existential basis of life. A strategy is developed which makes it possible to determine the systemic information of a living organism provided there is enough knowledge of the organism concerned.  相似文献   
444.
The ring-opening polymerization of l-lactide with calcium alkoxides generated in-situ from bis(tetrahydrofuran)calcium bis[bis(trimethylsilyl)amide] and 2-propanol are presented. The polymerization in THF at room temperature proceeds rapidly and in a living manner, giving poly(l-lactide)s of controlled molecular weight, low polydispersity, and tailored end-functionalities. Kinetic studies show the absence of an induction period and a pseudo-first order rate constant of 6.41 L mol–1 min–1, which is significantly higher than for related Y5(-O)(O i Pr)13– or aluminum alkoxide-initiated polymerizations. The initiation involves a two-step process: (1) alcoholysis of bis(tetrahydrofuran)calcium bis[bis(trimethylsilyl)amide] to give the corresponding calcium alkoxide and (2) ring-opening of l-lactide via acyl-oxygen cleavage and insertion into the calcium-alkoxide bond. In the presence of excess alcohol, fast and reversible exchange between free alcohol molecules and coordinated alkoxide ligands takes place. This allows tuning of the poly(l-lactide) molecular weight over a wide range.  相似文献   
445.
446.
Separation and chemical characterisation of specific compounds responsible for soil water repellency has not previously been achieved. Here we describe the extraction, separation and analysis by gas chromatography-mass spectrometry of organic compounds found in wettable and water repellent sandy soils from the Netherlands and United Kingdom. Fatty acids (C16–C24), amides (C14–C24), alkanes (C25–C33), aldehydes/ketones (C23–C31) and complex ring-containing structures were detected in all samples. We found a greater abundance of high molecular mass polar compounds in the water repellent samples.  相似文献   
447.
ABSTRACT: Synoptic water temperature measurements were taken in three temperate lakes located within 25 km of one another to study the effects of morphometry (and changes in weather) on seasonal and short-term thermal stratification characteristics. Two of the lakes had nearly the same surface areas and two had nearly identical mean depths; all were exposed to identical weather conditions. The dominance of weather over morphometry on the water surface temperature response was illustrated by the synoptic measurements in two different years. Stratification structure was also found to be dominated by weather for sufficiently deep lakes. Surface area effects were most subtle but explainable as sheltering effects. The onset of stratification was not, as traditionally described, a simple, gradual response of a lake to the annual solar radiation cycle. Rather it depends on a series of alternating heating, cooling, and mixing cycles similar to annual and diel cycles but with a period of approximately five days. These were in direct response to the passage of major weather systems and displayed no apparent time lag. No comparable synoptic water temperature data set could be found in the literature.  相似文献   
448.
A model to estimate the entry length to a fully developed diffusive boundary layer above a sediment bed, such as those found in lakes, reservoirs, rivers, and estuaries, is presented. The model is used to determine how the length of a sediment bed in mass-transfer experiments influences the measured vertical diffusive flux at the sediment-water interface. A nondimensional local mass flux is introduced in the form of a Sherwood number (Sh) and expressed as a function of both the distance from the leading edge of the sediment bed (x) and the Schmidt number (Sc). Similarly, a mean Sherwood number (Sh(ave)) for a sediment bed of length (L) is introduced. The diffusive boundary layer grows with distance, and its thickness depends on the Schmidt number (i.e., the diffusive boundary layer gets thicker and develops more quickly as the Schmidt number decreases). For Schmidt numbers greater than or equal to 100, the diffusive boundary layer begins to develop slowly but is fully developed when the nondimensional horizontal coordinate (x+) is approximately 1000. The Sherwood number is largest (i.e., infinity) near the leading edge of the sediment bed (i.e., at x = 0), decreases as the distance from the bed increases, and, finally, approaches a constant value for a fully developed diffusive boundary layer (Sh(infinity)). In this paper, the distance to a fully developed diffusive boundary layer (L99) and the required length of a sediment bed are related explicitly to Sc, sheer velocity (U*), and the relative errors of local or average Sherwood numbers (Sh or Sh(ave), respectively) against the Sherwood number for the fully developed diffusive boundary layer (Sh(infinity)). The lengths L99 and L decrease as the Schmidt number increases and become independent of the Schmidt number when Sc is greater than 1000. A longer sediment bed is needed when the shear velocity or the Schmidt number is small (e.g., L99 and L approximately 1.0 m and 8.0 m, respectively, for Sc = 500, U* = 0.1 cm/s, and a 3% acceptable error). Experimental studies may not be able to meet these requirements and an adjustment of measured mass-transfer rates at a sediment-water interface may be necessary. The magnitude of that adjustment is up to 50%. Its dependence on the Schmidt number, shear velocity, and bed length is given in this paper.  相似文献   
449.
450.
Oenema O  Pietrzak S 《Ambio》2002,31(2):159-168
The notion of management has undergone many changes during the past century. Nowadays, management is perceived as "specialized activity to achieve targets." Skill in management is the single most important factor determining the economic and environmental performance of agroecosystems. Nutrient management is "management of nutrients to achieve agronomic and environmental targets;" it requires proper understanding of nutrient cycling, site- and farm-specific guidelines and technology, and often direct coaching. These activities are diverse and complicated, especially in mixed farming systems that involve both crop and animal production. To be effective, economic and environmental targets must be coherent, flexible, and controllable. They also must be defined and implemented quantitatively at strategic, tactical, and operational levels. Data from farms in Poland and The Netherlands are used to show how economic incentives, provided through governmental policies and measures in both countries, can improve nutrient-use efficiency by a factor of 2 on many intensively managed mixed farming systems.  相似文献   
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