Leibniz University of Hanover

About: Leibniz University of Hanover is a education organization based out in Hanover, Niedersachsen, Germany. It is known for research contribution in the topics: Finite element method & Computer science. The organization has 14283 authors who have published 29845 publications receiving 682152 citations.

Twin Matter Waves for Interferometry Beyond the Classical Limit

Abstract: Interferometers with atomic ensembles are an integral part of modern precision metrology. However, these interferometers are fundamentally restricted by the shot noise limit, which can only be overcome by creating quantum entanglement among the atoms. We used spin dynamics in Bose-Einstein condensates to create large ensembles of up to 104 pair-correlated atoms with an interferometric sensitivity − 1 . 61 − 1 . 1 + 0. 98 decibels beyond the shot noise limit. Our proof-of-principle results point the way toward a new generation of atom interferometers.

The Distal Part of the Transition Zone Is the Most Aluminum-Sensitive Apical Root Zone of Maize

Abstract: For a better understanding of Al inhibition of root elongation, knowledge of the morphological and functional organization of the root apex is a prerequisite. We developed a polyvinyl chloride-block technique to supply Al (90 μm monomeric Al) in a medium containing agarose to individual 1-mm root zones of intact seedlings of maize (Zea mays L. cv Lixis). Root elongation was measured during a period of 5 h. After Al treatment, callose (5 h) and Al (1 h) contents of individual 1-mm apical root segments were determined. For comparison, callose and Al levels were also measured in root segments after uniform Al supply in agarose blocks to the 10-mm root apex. Only applying Al to the three apical 1-mm root zones inhibited root elongation after 1 h. The order of sensitivity was 1 to 2 > 0 to 1 > 2 to 3 mm. In the 1- to 2-mm root zone high levels of Al-induced callose formation and accumulation of Al was found, independently of whether Al was applied to individual apical root zones or uniformly to the whole-root apex. We conclude from these results that the distal part of the transition zone of the root apex, where the cells are undergoing a preparatory phase for rapid elongation (F. Baluska, D. Volkmann, P.W. Barlow [1996] Plant Physiol 112: 3–4), is the primary target of Al in this Al-sensitive maize cultivar.

An ecological 'footprint' of climate change

Abstract: Recently, there has been increasing evidence of species' range shifts due to changes in climate. Whereas most of these shifts relate ground truth biogeographic data to a general warming trend in regional or global climate data, we here present a reanalysis of both biogeographic and bioclimatic data of equal spatio-temporal resolution, covering a time span of more than 50 years. Our results reveal a coherent and synchronous shift in both species' distribution and climate. They show not only a shift in the northern margin of a species, which is in concert with gradually increasing winter temperatures in the area, they also confirm the simulated species' distribution changes expected from a bioclimatic model under the recent, relatively moderate climate change.

Mobile Visual Search

Abstract: Mobile phones have evolved into powerful image and video processing devices equipped with high-resolution cameras, color displays, and hardware-accelerated graphics. They are also increasingly equipped with a global positioning system and connected to broadband wireless networks. All this enables a new class of applications that use the camera phone to initiate search queries about objects in visual proximity to the user (Figure 1). Such applications can be used, e.g., for identifying products, comparison shopping, finding information about movies, compact disks (CDs), real estate, print media, or artworks.