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41.
Farmland habitat diversity in marginal European landscapes changed significantly in the past decades. Further changes toward homogenization are expected, particularly in the course of European agricultural policy. Based on three alternative transfer payment schemes, we modeled spatially explicit potential effects on the farmland habitat diversity in a marginal European landscape. We defined (1) a scenario with direct transfer payments coupled to production, (2) a scenario with direct transfer payments decoupled from production, and (3) a scenario phasing out all direct transfer payments. We characterized habitat diversity with three indices: habitat richness, evenness, and rarity. The habitat pattern in 1995 served as reference for comparison. All scenarios predicted a general trend of homogenization of the farmland habitat pattern, yet to a differing extent. Transfer payments coupled to production (Scenario 1) favored the abandonment of agricultural production, particularly in low-productive areas and arable land use in more productive areas. Habitat richness and habitat evenness had intermediate values in this scenario. Decoupling transfer payments from production (Scenario 2) supported grassland as most profitable farming system. This led to a grassland-dominated landscape with low values of all habitat diversity indices. Phasing out transfer payments (Scenario 3) resulted in complete abandonment or afforestation of agricultural land and extremely low values in all habitat diversity indices. Scenario results indicate that transfer payments may prevent cessation of agricultural production, but may not counteract homogenization in marginal landscapes. Conserving high farmland habitat diversity in such landscapes may require support schemes, e.g., Pillar Two of EU Common Agricultural Policy.  相似文献   
42.
2  H). As a consequence, the former proteolytic enzyme gained peroxidase activity and catalyzed the selective reduction of hydroperoxides. Due to the identical binding sites of the semisynthetic peroxidase and the protease, the substrate selectivity of seleno-subtilisin was predictable in view of the well-known selectivity of subtilisin.  相似文献   
43.
The objective was to assess head injury risks and kinematics of adult pedestrians and bicyclists in primary impact to the passenger cars and secondary impact to the ground using real world accident data and computer reconstructions of the accidents. For this purpose, a subsample of 402 pedestrians and 940 bicyclists from the GIDAS database, Germany, was used for the statistical analysis, from which 22 pedestrian and 18 bicyclist accidents were further selected for reconstruction. PC-Crash was used to calculate impact conditions, such as vehicle impact velocity, vehicle kinematic sequence, and thrown distance. These conditions were employed to identify the initial conditions in reconstruction in MADYMO program. A comparable analysis was conducted based on the results from accident analysis and computer reconstructions for the impact configurations and the resulting injury patterns of pedestrians and bicyclists in view of head injury risks. Differences in HIC, head-relative impact velocity, linear acceleration, maximum angular velocity and acceleration, contact force, thrown distance, Wrap Around Distance (WAD), and head contact time were evaluated. Injury risk curves were generated by using a logistic regression model for vehicle impact velocity. The results indicate that bicyclists suffered less severe injuries compared with severity of pedestrian injuries. In the selected samples, the AIS 2+ and AIS 3+ head injury risks for pedestrians are 50% probability at impact speed of 38.87 km/h and 54.39 km/h respectively, while for bicyclists at 53.66 km/h and 58.89 km/h respectively. The findings of high injury risks suggested that in the area with high frequency car-pedestrian accidents, the vehicle speed limit should be 40 km/h, while in the area with high frequency car-cyclist accidents the vehicle speed limit should be 50 km/h.  相似文献   
44.
ABSTRACT: Water quality was monitored for 17 months during base flow periods in six agricultural watersheds to evaluate the impact of riparian vegetation on suspended solids and nutrient concentrations. In areas without riparian vegetation, both instream algal production and seasonal low flows appeared to be major determinants of suspended solids, turbidity, and phosphorus concentrations. Peak levels of all parameters were reached during the summer when flows were reduced and benthic algal production was high. Similar summer peaks were reached in streams receiving major point inputs but peaks occurred downstream from the input. Instream organic production was less important in regulating water quality in areas with riparian vegetation and permanent flows. Concentrations of suspended solids remained relatively constant, while phosphorus and turbidity increased in association with leaf fall in autumn. Intermittent flow conditions in summer increased the importance of instream organic production in controlling water quality, even when riparian vegetation was present. Efforts to improve water quality in agricultural watersheds during base flow should emphasize maintenance of riparian vegetation and stable flow conditions.  相似文献   
45.
Zusammenfassung  Im Rahmen praktischer Untersuchungen der Autoren zu Umweltmanagementsystemen in der Landwirtschaft, und hier insbesondere der Umweltprüfung, zeigen sich die Besonderheiten der Agrarwirtschaft im Implementierungsproze?. Einige Bereiche k?nnen relativ einfach umgesetzt werden, andere Aspekte bedürfen einer differenzierteren Methodik als bei anderen Wirtschaftsbereichen. W?hrend sich das Managementaudit durch die übersichtliche Organisationsstruktur landwirtschaftlicher Betriebe meist als unkritisch erweist, werden beim Wirkungsund Rechtsaudit einige bereichsspezifische Probleme erkannt. Das Wirkungsaudit zeigt dem Anwender nach der Einführung einer neuen, speziell auf die Landwirtschaft angepa?ten Methodik der Stoffstrombilanzierung praxisorientierte Handlungspotentiale. Die Ergebnisse k?nnen je nach Bedarf auf Betriebs-, Betriebszweigoder Kostentr?gerebene ausgewiesen relevant, da sie einhohes ?kologischen Gef?hrdungspotential besitzen und bei den praktischen Erhebungen h?ufig Gegenstand von Beanstandungen waren. Diese betreffen vor allem die Lagerung von umweltrelevanten Stoffen (Pflanzenschutzmittel, Diesel, Jauche, Gülle, Festmist oder Sickers?fte) sowie die etwaigen Notwendigkeit und Beschaffenheit eines Waschplatzes. Die Konfliktbereiche werden beschrieben und darauf aufbauend Optionen zur Verbesserung aufgezeigt. Online-Publikationsdatum: 20.12.1999  相似文献   
46.
The registration of the present situation regarding environmental investigation is the basis for efficiently proceeding in the course of the implementation of environmental management systems (EMS). The basic analysis is found on the individual elements: reaction audit, management audit and compliance audit. Via an optimal performance of an environmental investigation while implementing an EMS, the basis for a maximum utilization has been created for the user as well for agriculture. Utilization for the company is provided by documentation of the organizational structure showing a transparency of procedures with regard to efficiency. Furthermore, an EMS is useful in the course of external tasks, e.g. public approach, business partners, position to authorities, deregulation or minimization of liability.  相似文献   
47.
Atmospheric phosphine (PH3) fluxes from typical types of wetlands and PH3 concentrations in adjacent atmospheric air were measured. The seasonal distribution of PH3 in marsh and paddy fields were observed. Positive PH3 fluxes are significantly related to high air temperature (summer season) and increased vegetation. It is concluded that vegetation speeds up the liberation of PH3 from soils, while water coverage might function as a diffusion barrier from soils or sediments to the atmosphere. The concentrations of atmospheric PH3 (ng m−3) above different wetlands decrease in the order of paddy fields (51.8 ± 3.1) > marsh (46.5 ± 20.5) > lake (37.0 ± 22.7) > coastal wetland (1.71 ± 0.73). Highest atmospheric PH3 levels in marsh are found in summer. In paddy fields, atmospheric PH3 concentrations in flourishing stages are higher than those in slowly growing stages.  相似文献   
48.
Several hundred accidents involving the use of circular saws and resulting in injury, to hands or fingers occur each year in Germany.In the presented project, new approaches for the prevention of hand injuries and for the contactless detection of fingers are being investigated for comprehensive protection on circular saws. The basic principles can be applied to other machines with manual loading and/or unloading. This paper describes several principles to distinct human skin and wood and a safety guard that prevents touching the rotating blade. In a first approach a reliable protective device with functional diversity has been developed using a passive infrared sensor in combination with a capacitive field sensor. Second the distinction between skin and wood or other material is done by dedicated kind of spectral analysis in the near infrared region. With a kind of light curtain the intrusion into the dangerous zone near the blade can be prevented.The safety guard protects the operator’s hand within 50 ms. The forces of the protective system peak at no more than 120 N. We are presenting a complete strategy for such different tasks as cutting wedges, stopped cutting and hidden cutting, which have a very high odds ratio.  相似文献   
49.
Understanding patterns, dynamics, and drivers of land use is crucial for improving our ability to cope with sustainability challenges. The human appropriation of net primary production (HANPP) framework provides a set of integrated socio-ecological indicators that quantify how land use alters energy flows in ecosystems via land conversions and biomass harvest. Thus, HANPP enables researchers to systematically and consistently assess the outcome of changes in land cover and land-use intensity across spatio-temporal scales. Yet, fine-scale HANPP assessments are so far missing, an information important to address site-specific ecological implications of land use. Here, we provide such an assessment for Europe at a 1-km scale for the years 1990, 2000, and 2006. The assessment was based on a consistent land-use/biomass flow dataset derived from statistical data, remote sensing maps, and a dynamic global vegetation model. We find that HANPP in Europe amounted to ~43 % of potential productivity, well above the global average of ~25 %, with little variation in the European average since 1990. HANPP was highest in Central Europe and lower in Northern and Southern Europe. At the regional level, distinct changes in land-use intensity were observed, most importantly the decline of cropland areas and yields following the breakdown of socialism in Eastern Europe and the subsequent recovery after 2000, or strong dynamics related to storm events that resulted in massive salvage loggings. In sum, however, these local dynamics cancelled each other out at the aggregate level. We conclude that this finding warrants further research into aspects of the scale-dependency of dynamics and stability of land use.  相似文献   
50.
A fetus with thanatophoric dysplasia type 2 (TD2) associated with cloverleaf skull and abnormal development of the corpus callosum is reported. This case represents the first prenatal direct visualization of a partial agenesis of the corpus callosum (ACC) using high-resolution ultrasonography and colour power Doppler, which was confirmed by post-mortem magnetic resonance imaging (MRI). The causal link between cloverleaf skull in TD and partial ACC is discussed. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
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