Combining Predicted and Live Traffic with Time-Dependent A* Potentials

We study efficient and exact shortest path algorithms for routing on road networks with realistic traffic data. For navigation applications, both current (i.e., live) traffic events and predictions of future traffic flows play an important role in routing. While preprocessing-based speedup techniques have been employed successfully to both settings individually, a combined model poses significant challenges. Supporting predicted traffic typically requires expensive preprocessing while live traffic requires fast updates for regular adjustments. We propose an A*-based solution to this problem. By generalizing A* potentials to time dependency, i.e. the estimate of the distance from a vertex to the target also depends on the time of day when the vertex is visited, we achieve significantly faster query times than previously possible. Our evaluation shows that our approach enables interactive query times on continental-sized road networks while allowing live traffic updates within a fraction of a minute. We achieve a speedup of at least two orders of magnitude over Dijkstra's algorithm and up to one order of magnitude over state-of-the-art time-independent A* potentials.Comment: 19 pages, 5 figures. Full version of ESA22 pape

Enhanced Productivity and Fish Abundance at a Submarine Spring in a Coastal Lagoon on Tahiti, French Polynesia

Submarine groundwater discharge (SGD), the direct discharge of groundwater into the sea, is abundant around the globe. Fresh SGD can occur as focused flow in submarine springs. However, little is known on the impact of submarine springs on marine organisms. For a better understanding of the interaction between SGD and its surrounding organisms, the impact of SGD on the abundance of fish was investigated in a coastal lagoon of Tahiti, French Polynesia. The study is based on the assumption of an enhanced biological production due to increased amounts of nutrient input caused by terrestrial groundwater supply into the sea. Biofouling processes and zooplankton samples were used as indicators for elevated nutrient input due to submarine springs. The main objective was to investigate the effect on the abundance of fish assuming a higher fish abundance possibly caused by a bottom-up control. Presented data show a significantly higher abundance around a submarine spring as well as significantly larger growth of algal turfs exposed to groundwater discharge. Zooplankton evaluations suggest slightly higher abundances around the submarine spring. The results suggest elevated nutrient concentrations transmitted by submarine springs may cause a bottom-up control resulting in a higher abundance of fish around the investigated submarine spring

Energy-filtered transmission electron microscopy of biological samples on highly transparent carbon nanomembranes

Ultrathin carbon nanomembranes (CNM) comprising crosslinked biphenyl precursors have been tested as support films for energy-filtered transmission electron microscopy (EFTEM) of biological specimens. Due to their high transparency CNM are ideal substrates for electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI) of stained and unstained biological samples. Virtually background-free elemental maps of tobacco mosaic virus (TMV) and ferritin have been obtained from samples supported by ~ 1 nm thin CNM. Furthermore, we have tested conductive carbon nanomembranes (cCNM) comprising nanocrystalline graphene, obtained by thermal treatment of CNM, as supports for cryoEM of ice-embedded biological samples. We imaged ice-embedded TMV on cCNM and compared the results with images of ice-embedded TMV on conventional carbon film (CC), thus analyzing the gain in contrast for TMV on cCNM in a quantitative manner. In addition we have developed a method for the preparation of vitrified specimens, suspended over the holes of a conventional holey carbon film, while backed by ultrathin cCNM

A Service-Oriented Operating System and an Application Development Infrastructure for Distributed Embedded Systems

The paradigm of service-orientation promises a significant ease of use in creating and managing distributed software systems. A very important aspect here is that also application domain experts and stakeholders, who are not necessarily skilled in computer programming, get a chance to create, analyze, and adapt distributed applications. However, up to now, service-oriented architectures have been mainly discussed in the context of complex business applications. In this paper we will investigate how to transfer the benefits of a service-oriented architecture into the field of embedded systems, so that this technology gets accessible to a much wider range of users. As an example, we will demonstrate this scheme for sensor network applications. In order to address the problem of limited device resources we will introduce a minimal operating system for such devices. It organizes all pieces of code running on a sensor node in a service-oriented fashion and also features the relocation of code to a different node at runtime. We will demonstrate that it is possible to design a sensor network application from a set of already existing services in a highly modular way by employing already existing technologies and standards

Loss of LRPPRC causes ATP synthase deficiency

Defects of the oxidative phosphorylation system, in particular of cytochrome-c oxidase (COX, respiratory chain complex IV), are common causes of Leigh syndrome (LS), which is a rare neurodegenerative disorder with severe progressive neurological symptoms that usually present during infancy or early childhood. The COX-deficient form of LS is commonly caused by mutations in genes encoding COX assembly factors, e.g. SURF1, SCO1, SCO2 or COX10. However, other mutations affecting genes that encode proteins not directly involved in COX assembly can also cause LS. The leucine-rich pentatricopeptide repeat containing protein (LRPPRC) regulates mRNA stability, polyadenylation and coordinates mitochondrial translation. In humans, mutations in Lrpprc cause the French Canadian type of LS. Despite the finding that LRPPRC deficiency affects the stability of most mitochondrial mRNAs, its pathophysiological effect has mainly been attributed to COX deficiency. Surprisingly, we show here that the impaired mitochondrial respiration and reduced ATP production observed in Lrpprc conditional knockout mouse hearts is caused by an ATP synthase deficiency. Furthermore, the appearance of inactive subassembled ATP synthase complexes causes hyperpolarization and increases mitochondrial reactive oxygen species production. Our findings shed important new light on the bioenergetic consequences of the loss of LRPPRC in cardiac mitochondria