457 research outputs found
Ausgewählte Parameter der Ökoeffizienz im ökologischen und konventionellen Marktfruchtbau Schleswig-Holsteins
Approximately 13 % of the total greenhouse gas emissions in Germany are caused by agricultural practices. From an environmental and economic point of view, gaseous N losses as well as nitrate leaching to groundwater play, a significant role. The aim of the present study is to analyze abiotic environmental effects of organic and conventional all-arable farming at a highly productive site in Northern Germany. Two different organic crop rotations with 25% vs. 40% legumes and no application of external N-fertilizers were compared over a two-year period to a typical site specific conventional rotation at an average mineral fertilser input of 195 kg N ha-1 a-1. For gas flux measurement, the closed-chamber method was applied. Nitrate leaching was measured by using ceramic suction cups. The results of the ongoing project show that organic farming can implement the objectives of water- and climate protection in the area more effectively than conventional systems. By trend, the GHG emissions of the organic crop rotations were lower, both per hectare and per unit of product. While for the organic systems nitrate leaching per hectare was lower, higher values were detected when using the product unit as a scale for comparisons
Energieeffizienz der Fruchtfolgen viehloser Ökobetriebe und eines konventionellen Ackerbaubetriebs in Schleswig-Holstein
Several studies have shown that changing from conventional to organic farming is an alternative to reduce negative impacts on the environment, for example nitrogen losses, reduced biodiversity and input of fossil energy per unit land and per unit product. In organic agriculture, as well, there is currently a trend towards specialized farming systems. To compensate for the lack of data on energy efficiency measured at farm scale, a comparison between three differently managed organic all-arable crop rotations and a typical rotation of typical regional N-intensive conventional farm was carried out over a two-year period at a highly productive site in northern Germany. Comparing the all-arable crop rotations, the organic systems had a 62 % lower output measured in MJ metabolizable energy. Due to a 74 % lower input of fossil energy, the organic crop rotations showed a 37.7 % higher energy efficiency than the compared conventional rotation. Taking into account the area of land needed to produce the same amount of energy, the conventional system was more efficient. The net energy gain per hectare (derived from subtracting energy input from the gross energy output) of the conventional farm of 95.96 GJ ha-1 was considerably higher than the average of the 3 organic crop rotations (39.69 GJ ha-1)
Nitrous Oxide Emissions and Methane Uptake from Organic and Conventionally Managed Arable Crop Rotations on Farms in Northwest Germany
Land-use extensification by shifting from conventional to organic arable farming is often discussed as a measure for reducing greenhouse gas (GHG) emissions from agricultural land. Doubts about the benefits arise when emissions are calculated per product unit, particularly where high yields are possible under conventional management. Among the non-CO2 GHG emissions, nitrous oxide (N2O) is the main contributor from arable land and is controlled by soil type, environmental conditions and management. In order to investigate how land-use change from conventional to organic farming would perform under highly productive site conditions in northwest Germany, and how this would affect the important greenhouse gases N2O and methane (CH4), an on-farm field research was conducted over two experimental years. Two site-specific organic crop rotations, (i) with 25% legumes (grass + clover - winter wheat – winter rye – oats) and (ii) with 40% legumes (grass + clover – winter wheat – winter rye – spring field peas – winter rye), were compared with (iii) a conventional arable rotation (winter oilseed rape – winter wheat – winter wheat – sugar beet – winter wheat) and two reference systems, (iv) extensive grassland and (v) a beech forest), which were chosen as the baseline. The results showed that organic farming had lower N2O emissions of 0.7 N2O–N ha−1 year−1 than the conventional rotation, with 2.1 kg N2O–N ha−1 year−1 (p < 0.05), but higher emissions than the extensive grassland (0.3 kg N2O ha−1 year−1) and beech forest (0.4 kg N2O ha−1 year−1). CH4 emissions were a negligible part of total GHG emissions (as CO2 equivalents) in the two arable systems, and considerable uptake of CH4 from the forest soils showed this was a GHG sink in the first experimental year
Adaptive strategies and environmental significance of lingulid brachiopods across the late Permian extinction
Competition and mimicry: the curious case of chaetae in brachiopods from the middle Cambrian Burgess Shale
Increased Motor Activity During REM Sleep Is Linked with Dopamine Function in Idiopathic REM Sleep Behavior Disorder and Parkinson Disease
STUDY OBJECTIVES: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by impaired motor inhibition during REM sleep, and dream-enacting behavior. RBD is especially associated with α-synucleinopathies, such as Parkinson disease (PD). Follow-up studies have shown that patients with idiopathic RBD (iRBD) have an increased risk of developing an α-synucleinopathy in later life. Although abundant studies have shown that degeneration of the nigrostriatal dopaminergic system is associated with daytime motor function in Parkinson disease, only few studies have investigated the relation between this system and electromyographic (EMG) activity during sleep. The objective of this study was to investigate the relationship between the nigrostriatal dopamine system and muscle activity during sleep in iRBD and PD. METHODS: 10 iRBD patients, 10 PD patients with PD, 10 PD patients without RBD, and 10 healthy controls were included and assessed with (123)I-N-omega-fluoropropyl-2-beta-carboxymethoxy-3beta-(4-iodophenyl) nortropane ((123)I-FP-CIT) Single-photon emission computed tomography (SPECT) scanning ((123)I-FP-CIT SPECT), neurological examination, and polysomnography. RESULTS: iRBD patients and PD patients with RBD had increased EMG-activity compared to healthy controls. (123)I-FP-CIT uptake in the putamen-region was highest in controls, followed by iRBD patients, and lowest in PD patients. In iRBD patients, EMG-activity in the mentalis muscle was correlated to (123)I-FP-CIT uptake in the putamen. In PD patients, EMG-activity was correlated to anti-Parkinson medication. CONCLUSIONS: Our results support the hypothesis that increased EMG-activity during REM sleep is at least partly linked to the nigrostriatal dopamine system in iRBD, and with dopamine function in PD. CITATION: Zoetmulder M, Nikolic M, Biernat H, Korbo L, Friberg L, Jennum P. Increased motor activity during rem sleep is linked with dopamine function in idiopathic REM sleep behavior disorder and Parkinson disease. J Clin Sleep Med 2016;12(6):895–903
Prepulse inhibition is associated with attention, processing speed, and 123I-FP-CIT SPECT in Parkinson's disease
Earliest ontogeny of early Cambrian acrotretoid brachiopods : first evidence for metamorphosis and its implications
Our understanding of the ontogeny of Palaeozoic brachiopods has changed significantly during the last two decades. However, the micromorphic acrotretoids have received relatively little attention, resulting in a poor knowledge of their ontogeny, origin and earliest evolution. The uniquely well preserved early Cambrian fossil records in South China provide a great new opportunity to investigate the phylogenetically important ontogeny of the earliest acrotretoid brachiopods, and give new details of the dramatic changes in anatomy of acrotretoid brachiopods during the transition from planktotrophic larvae to filter feeding sedentary juveniles
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