Combined hyperlipidemia in transgenic mice overexpressing human apolipoprotein Cl

We have generated transgenic mice over-expressing human apolipoprotein CI (apo CI) using the native gene joined to the downstream 154-bp liver-specific enhancer that we defined for apo E. Human apo CI (HuCI)-transgenic mice showed elevation of plasma triglycerides (mg/dl) compared to controls in both the fasted (211 +/- 81 vs 123 +/- 52, P = 0.0001) and fed (265 +/- 105 vs 146 +/- 68, P < 0.0001) states. Unlike the human apo CII (HuCII)- and apo CIII (HuCIII)-transgenic mouse models of hypertriglyceridemia, plasma cholesterol was disproportionately elevated (95 +/- 23 vs 73 +/- 23, P = 0.002, fasted and 90 +/- 24 vs 61 +/- 14, P < 0.0001, fed). Lipoprotein fractionation showed increased VLDL and IDL + LDL with an increased cholesterol/triglyceride ratio (0.114 vs 0.065, P = 0.02, in VLDL). The VLDL apo E/apo B ratio was decreased 3.4-fold (P = 0.05) and apo CII and apo CIII decreased in proportion to apo E. Triglyceride and apo B production rates were normal, but clearance rates of VLDL triglycerides and postlipolysis lipoprotein "remnants" were significantly slowed. Plasma apo B was significantly elevated. Unlike HuCII- and HuCIII-transgenic mice, VLDL from HuCI transgenic mice bound heparin-Sepharose, a model for cell-surface glycosaminoglycans, normally. In summary, apo CI overexpression is associated with decreased particulate uptake of apo B-containing lipoproteins, leading to increased levels of several potentially atherogenic species, including cholesterol-enriched VLDL, IDL, and LDL.     

Online segmentation of time series based on polynomial least-squares approximations

The paper presents SwiftSeg, a novel technique for online time series segmentation and piecewise polynomial representation. The segmentation approach is based on a least-squares approximation of time series in sliding and/or growing time windows utilizing a basis of orthogonal polynomials. This allows the definition of fast update steps for the approximating polynomial, where the computational effort depends only on the degree of the approximating polynomial and not on the length of the time window. The coefficients of the orthogonal expansion of the approximating polynomial-obtained by means of the update steps-can be interpreted as optimal (in the least-squares sense) estimators for average, slope, curvature, change of curvature, etc., of the signal in the time window considered. These coefficients, as well as the approximation error, may be used in a very intuitive way to define segmentation criteria. The properties of SwiftSeg are evaluated by means of some artificial and real benchmark time series. It is compared to three different offline and online techniques to assess its accuracy and runtime. It is shown that SwiftSeg-which is suitable for many data streaming applications-offers high accuracy at very low computational costs.     

Model Checking Games for the Quantitative μ-Calculus

We investigate quantitative extensions of modal logic and the modal μ-calculus, and study the question whether the tight connection between logic and games can be lifted from the qualitative logics to their quantitative counterparts. It turns out that, if the quantitative μ-calculus is defined in an appropriate way respecting the duality properties between the logical operators, then its model checking problem can indeed be characterised by a quantitative variant of parity games. However, these quantitative games have quite different properties than their classical counterparts, in particular they are, in general, not positionally determined. The correspondence between the logic and the games goes both ways: the value of a formula on a quantitative transition system coincides with the value of the associated quantitative game, and conversely, the values of quantitative parity games are definable in the quantitative μ-calculus.     

Evaluating and improving the content access in KAD

We analyze in detail the content retrieval process in kad. kad implements content search (publish and retrieval) functions that use the Kademlia Distributed Hash Table for content routing. Node churn is quite common in peer-to-peer systems and results in information loss and stale routing table entries. To deal with node churn, kad issues parallel route requests and publishes multiple redundant copies of each piece of information. We identify the key design parameters in kad and present an analytical model to evaluate the impact of changes in the values of these parameters on the overall lookup latency and message overhead. Extensive measurements of the lookup performance using an instrumented client allow us to validate the model. The overall lookup latency is in most cases 5 s or larger. We elucidate the cause for such high lookup latencies and propose an improved scheme that significantly decreases the overall lookup latency without increasing the overhead.     

Human eye-head co-ordination in natural exploration

During natural behavior humans continuously adjust their gaze by moving head and eyes, yielding rich dynamics of the retinal input. Sensory coding models, however, typically assume visual input as smooth or a sequence of static images interleaved by volitional gaze shifts. Are these assumptions valid during free exploration behavior in natural environments? We used an innovative technique to simultaneously record gaze and head movements in humans, who freely explored various environments (forest, train station, apartment). Most movements occur along the cardinal axes, and the predominance of vertical or horizontal movements depends on the environment. Eye and head movements co-occur more frequently than their individual statistics predicts under an independence assumption. The majority of co-occurring movements point in opposite directions, consistent with a gaze-stabilizing role of eye movements. Nevertheless, a substantial fraction of eye movements point in the same direction as co-occurring head movements. Even under the very most conservative assumptions, saccadic eye movements alone cannot account for these synergistic movements. Hence nonsaccadic eye movements that interact synergistically with head movements to adjust gaze cannot be neglected in natural visual input. Natural retinal input is continuously dynamic, and cannot be faithfully modeled as a mere sequence of static frames with interleaved large saccades.     

Trench-Hall devices

A trench-Hall device sensitive to magnetic inductions parallel to the chip surface is reported in this paper. The vertically oriented active region is defined by two parallel trenches with a distance of only 2.4 μm. Deep contacts connect the active region of the device at its bottom at a depth of 20 μm. These deep contacts allow a symmetrical operating condition of the active region analogous to a lateral symmetrical Hall plate, which is favorable for dynamic offset reduction. With the presented technology, trench-Hall devices with a sensitivity of 320 V/A with a nonlinearity below 0.1% are realized. Additionally, the presented fabrication technique enables the electrically insulated cointegration of sensor and circuitry on a single CMOS chip     

A structured marketplace for arbitrary services

Creating simple marketplaces with common rules, that enable the dynamic selection and consumption of functionality, is the missing link to allow small businesses to enter the cloud, not only as consumers, but also as vendors. In this paper, we present the concepts behind a hybrid service and process repository that can act as the foundation for such a marketplace, as well as a prototype that allowed us to test various real-world scenarios. The advantage of a hybrid service and process repository is that, it not only holds a flat list of services, but also exposes a generic set of use cases, that it obtains information on how specific services can be used to implement the use cases as well as information to select services at run-time according to customer’s goal functions.     

The OODB path-method generator (PMG) using access weights and precomputed access relevance

A path-method is used as a mechanism in object-oriented databases (OODBs) to retrieve or to update information relevant to one class that is not stored with that class but with some other class. A path-method is a method which traverses from one class through a chain of connections between classes and accesses information at another class. However, it is a difficult task for a casual user or even an application programmer to write path-methods to facilitate queries. This is because it might require comprehensive knowledge of many classes of the conceptual schema that are not directly involved in the query, and therefore may not even be included in a user's (incomplete) view about the contents of the database. We have developed a system, called path-method generator (PMG), which generates path-methods automatically according to a user's database-manipulating requests. The PMG offers the user one of the possible path-methods and the user verifies from his knowledge of the intended purpose of the request whether that path-method is the desired one. If the path method is rejected, then the user can utilize his now increased knowledge about the database to request (with additional parameters given) another offer from the PMG. The PMG is based on access weights attached to the connections between classes and precomputed access relevance between every pair of classes of the OODB. Specific rules for access weight assignment and algorithms for computing access relevance appeared in our previous papers [MGPF92, MGPF93, MGPF96]. In this paper, we present a variety of traversal algorithms based on access weights and precomputed access relevance. Experiments identify some of these algorithms as very successful in generating most desired path-methods. The PMG system utilizes these successful algorithms and is thus an efficient tool for aiding the user with the difficult task of querying and updating a large OODB. Received July 19, 1993 / Accepted May 16, 1997     

Lanthanzirkonat: ein innovatives Wärmedämmschichtmaterial. Lanthanum zirconate: an innovative Thermal Barrier Material

This paper presents the work of the research project AiF‐13114 N/1. Within the scope of this project coating systems from Lanthanum Zirconate and Y ttria s tabilised Z irconia (YSZ) were developed by use of E lectron B eam P hysical V apour D eposition (EB‐PVD). In addition, the potentials of Lanthanum Zirconate and YSZ as thermal barrier coatings within gas turbines were examined. Basis of the coating development was the use of powdery Lanthanum and YSZ, that were vaporised in a PVD‐machine from a double‐grooved cupreous crucible. Process parameters are evaluated to gain long lasting, columnar Lanthanum Zirconate EB‐PVD coatings with high stability, low heat conductivity a higher sintering inertness, that offer the opportunity to increase the temperature within the first stage of a gas turbine system [1, 2, 3, 4, 5, 6]. Therefor YSZ ‐ commonly used as conventional thermal barrier coating ‐ was used as a reference system during the tests. As base material Inconel Alloy 600 (a nickel‐based superalloy) was applied. The microstructure and the topography of the developed coating systems were characterized with the help of scanning electron microscopy. Nanoindentation proved to be a measurement method in order to define the stiffness distribution along the columns. The thermal cycle durability was determined via thermal cycle test.     

Local outlier detection reconsidered: a generalized view on locality with applications to spatial, video, and network outlier detection

Outlier detection research has been seeing many new algorithms every year that often appear to be only slightly different from existing methods along with some experiments that show them to “clearly outperform” the others. However, few approaches come along with a clear analysis of existing methods and a solid theoretical differentiation. Here, we provide a formalized method of analysis to allow for a theoretical comparison and generalization of many existing methods. Our unified view improves understanding of the shared properties and of the differences of outlier detection models. By abstracting the notion of locality from the classic distance-based notion, our framework facilitates the construction of abstract methods for many special data types that are usually handled with specialized algorithms. In particular, spatial neighborhood can be seen as a special case of locality. Here we therefore compare and generalize approaches to spatial outlier detection in a detailed manner. We also discuss temporal data like video streams, or graph data such as community networks. Since we reproduce results of specialized approaches with our general framework, and even improve upon them, our framework provides reasonable baselines to evaluate the true merits of specialized approaches. At the same time, seeing spatial outlier detection as a special case of local outlier detection, opens up new potentials for analysis and advancement of methods.