191 research outputs found
Wann fährt man schon 30 km/h in 30 km/h-Zonen?
Dieses Experiment dient der Untersuchung des Fahrverhaltens von Kraftfahrzeugführern in Abhängigkeit von Gestaltungsmerkmalen der jeweiligen Straßenverkehrssituation. Schwerpunktmäßig wird der Einfluß von Gestaltungsmerkmalen, insbesondere auch von Maßnahmen zur Geschwindigkeitsreduktion, auf die Fahrgeschwindigkeiten untersucht. Die Versuchspersonen "durchfahren" im Videosimulator eine Fahrstrecke mit verschiedenen Verkehrssituationen. Die Unterschiede in den Situationen bestehen zum einen in der straßenbaulichen Gestaltung, zum anderen in situativen statischen und dynamischen Kennzeichen der Verkehrsszenen. Die Versuchspersonen können mit der Bedienung des Gas- und Bremspedals die Abspielgeschwindigkeit des Videofilms und damit die wahrgenommene "Fahrgeschwindigkeit" regulieren. Es wird ein deutlicher Einfluß der Gestaltungsmerkmale der durchfahrenen Straßenverkehrssituationen auf die gewählten Fahrgeschwindigkeiten sichtbar: Geschwindigkeitsreduzierend wirken statische Gestaltungsmerkmale wie Fahrbahnverengungen und Versätze, aber auch rein optische Verengungen der Fahrbahn. Kraftfahrer zeigen eine deutliche Bremsbereitschaft vor Bodenschwellen. Dagegen werden regulative Maßnahmen (Beschilderung) nur sehr kurzzeitig wirksam, nach einer vorübergehenden Verlangsamung vor dem Passieren des Verkehrszeichens wird anschließend sogar tendenziell schneller gefahren als vor der Maßnahme. Darüber hinaus werden Angaben von Höchstgeschwindigkeiten als Sollvorgaben für die Mindestgeschwindigkeiten interpretiert und dementsprechend häufig überschritten. Die älteren Autofahrer "fahren" im Durchschnitt in allen Situationen langsamer als jüngere Autofahrer und Autofahrer mittleren Alters, die jüngeren Autofahrer "durchfahren" alle Situationen mit höherer Geschwindigkeit als die Fahrer der anderen Altersgruppen. Besonders einige der jüngeren Autofahrer fallen durch extrem hohe Geschwindigkeiten auf
Ertrag und Qualitätsparameter von Winterweizensorten aus biologischer und konventioneller Züchtung in Luxemburg
Thirteen winter wheat varieties (Triticum aestivum L.) bred in conventional breeding programs and seven varieties from organic breeding were tested under organic conditions in two locations in 2009/10 and 2010/11 in Luxembourg. The objective was to analyze whether these conditions, organic varieties perform better than conventional ones. Grain yield (dt ha-1), protein content (%) and Zeleny sedimentation value were analyzed. The effect of the factor variety was statistically significant at a probability level of 0.05 for the three traits. For grain yield, the variety x year x location interaction was significant. For protein content, the variety x year interaction was significant. Location x year interaction was significant for sedimentation value. Results indicate that organic varieties generally lead to lower grain yields with higher baking quality (protein content and sedimentation value) than conventional varieties. However, a large range of grain yields, protein contents and sedimentation values were observed for both categories
Biologische Landwirtschaft als Strategie für einen pro-aktiven und nachhaltigen Wasserschutz in Luxemburg
In 2009, the water resource management plan came into force in Luxembourg, an implementation of the water framework directive 2000/60/EG. However the main goal, to improve the quality of the water bodies to Through the new management plan (2015-2021) this goal should be reached. The
organic cultivation is one of these actions of the old and new management plan, although it was rarely implemented so far. Therefore, the aims of the study were to
identify potential barriers for the conversion to organic and to develop strategies in order to promote water protection through organic farming. At first, the existing barriers, mainly in the socio-economic and the political fields as well as the water-related regulations, should be gradually eliminated. Subsequently an ideal concept combining e cooperation between actors of the government, the water industry and the agricultural sector is needed
Anbauwürdigkeit und Vorfruchtwert verschiedener Körnerleguminosen-Anbausysteme im Praxisversuch in Luxemburg
Due to the protein deficit in Europe and the many negative impacts related to soy imports from overseas, it is important to increase the cultivation of grain legumes for
regional fodder production. Therefore, as part of the COBRA project, two on-farm trial of different grain legume cropping systems were set up at two Luxembourgish organic
farms, with the aim to demonstrate the practicality of growing grain legumes and to study their fodder and pre-crop value, as well as their suitability for cultivation under
organic growing conditions in Luxembourg. Overall, all the tested grain legumes, with the exception of winter faba bean in Colmar-Berg, showed good suitability for regional
high-protein fodder production. Both lupin species showed a good previous crop value at both locations, as well as good suitability for cultivation. However, due to the high
anthracnose susceptibility of white lupin, this crop cannot be recommended for cultivation on a larger scale
Structure-Function Analysis of Axonal Fragile X Mental Retardation Protein
Silencing of the Fragile X Mental Retardation Protein (FMRP)-encoding gene Fmr1 causes Fragile X Syndrome, the leading known cause of autism. FMRP is an alternatively spliced, multidomain, RNA-binding protein most highly expressed in the brain that regulates mRNA transport and translation. Its function is well-characterized in dendrites but it is also found in the cell body, axons, and in the nucleus. Functioning throughout neurons suggests that some mechanism exists whereby it is appropriately transported and that this mechanism requires one or more of its domains. FMRP is alternatively spliced to yield at least 12 splice forms. These differ from each other in which domains and post-translational modification sites are present or absent. Our hypothesis is that one or more domains is required for axonal localization of FMRP. This is tested using EGFP-tagged FMRP splice form constructs to identify whether certain ones are preferentially localized to axons over others as well as mutation-containing constructs to identify one or more domains that are required for the mechanism of axonal localization of FMRP. These constructs are transfected into cultured rat cortical neurons with tdTomato and examined for differences in axonal localization, length, puncta distribution and density, and axonal arbor complexity, a process regulated by FMRP. All splice forms showed axonal localization at equivalent efficiencies and quantities suggesting that all are able to function in axons. Since the N-terminus is well-conserved between splice forms while the C-terminus is more variable due to the alternative splicing events, it was concluded that the domain required for axonal localization is N-terminal to the first splice site. Using a model for FMRP regulation of axonal arbor complexity in which overexpression of splice forms that function in axon growth and branching would oversimplify axonal arbors, SF7 and SF9-transfected neurons had reduced complexity. The domain(s) required for this function may be C-terminal. Because there are several domains in this region affected by alternative splicing, individual mutant analysis was required to narrow down the possibilities. All FMRP-SF7 mutant constructs showed an ability to localize to axons, supporting the idea that the region required for axonal localization is in the N-terminus. Intriguingly, the NES34A mutation in which the nuclear export sequence (NES) is deleted showed an increased efficiency over WT to localize axonally. Furthermore, the S500A, S500D and the ΔRGG mutants showed decreased puncta densities in axons. Axonal arbor complexity was not affected in neurons transfected with NES deletion or S500 mutants suggesting these domains may be required for FMRP to function in axon growth and branching regulation. Our results suggest a mechanism of axonal localization of FMRP that requires a region in the N-terminus which allows for all splice forms to be localized and function axonally. A region in the C-terminus is required for FMRP to function in regulation of axonal arbor complexity and this region may be the either the NES or S500 phosphorylation site or both. This is the first known attempt at elucidating a mechanism for differential localization of FMRP splice forms and the role of FMRP domains in axonal localization.M.S., Biology -- Drexel University, 201
Optimal Stratification and Allocation for the June Agricultural Survey
A computational approach to optimal multivariate designs with respect to stratification and allocation is investigated under the assumptions of fixed total allocation, known number of strata, and the availability of administrative data correlated with thevariables of interest under coefficient-of-variation constraints. This approach uses a penalized objective function that is optimized by simulated annealing through exchanging sampling units and sample allocations among strata. Computational speed is improved through the use of a computationally efficient machine learning method such as K-means to create an initial stratification close to the optimal stratification. The numeric stability of the algorithm has been investigated and parallel processing has been employed where appropriate. Results are presented for both simulated data and USDA’s June Agricultural Survey. An R package has also been made available for evaluation
Eignung verschiedener Körnerleguminosen als Vorfrucht für Winterweizen in ökologischen Fruchtfolgen
The Aim of this study has been to evaluate in two two-year field trials the pre-crop effect of different grain legumes (e.g. soy bean, peas or lupines) in the same environment and to detect possible effects of grain legumes on the N-supply, the yield potential and the yield structure of the subsequent crop winter wheat. According to different pre-crop yields, a higher but different nitrogen supply for subsequent winter wheat was observed in all N2-fixing pre-crop treatments. In contrast to non-fixings control higher NO3-N contents in soil and higher yields in subsequent winter wheat (up to 24 dt*ha- 1 surplus) were observed
LeguTec – mechanische Beikrautregulierung im Sojaanbau in Luxemburg
Fünf mechanische Beikrautregulierungsmethoden im Sojaanbau werden unter praxisnahen Bedingungen auf drei Bio-Betrieben in Luxemburg seit dem Frühjahr 2018 getestet. Die Feldversuche werden in vier Wiederholungen einschließlich Kontrollparzellen durchgeführt. Verschiedene Boniturparameter werden vor und nach jeder Regulierung sowie zur Blüte und zur Ernte erhoben, um die Effizienz der verwendeten Techniken in Bezug auf den Ertrag zu bewerten. Erste Resultate zeigen höhere Erträge und eine geringere Beikrautdeckung zur Blüte in den Hackvarianten im Vergleich zu den Striegelvarianten
ABILITY OF COMMERCIALLY AVAILABLE SOYBEAN BRADYRHIZOBIA INOCULANTS FOR COOL GROWING CONDITIONS IN CENTRAL EUROPE
In Central Europe the inoculation of soybean (Glycine max (L.) Merr.) with different Bradyrhizobia inoculants has led to unsatisfying nodulation results under low temperature conditions. The aim of this study was to test the capacity of commercially available inoculants under cool growing conditions in Central Europe. In 2011 and 2012 four Bradyrhizobia inoculants were tested on three early soybean varieties in a field trial in Germany. The number of nodules, yield and protein content were assessed. Two years data showed a successful nodulation of Product 4, Product 3 and Product 2 while Product 1 cannot be recommended. Independently of soybean variety, all of the three successful inoculants can be advised regarding grain yield. Protein content and protein yield depend on the combination of inoculants and soybean variety. Over the years Product 4 was the most reliable inoculant
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