Commodity Futures Trading Commission v. Weintraub

After presenting a general discussion of the attorney-client privilege, this casenote will discuss the facts underlying Weintraub and then review the rationales of the Seventh Circuit and the Supreme Court in their respective holdings. This casenote will discuss other arguments which have been raised in support of the trustee\u27s authority over the privilege. The casenote will conclude with a discussion of other policy and precedent arguments which urge that the trustee should not be given this authority

Collision induced spatial organization of microtubules

The dynamic behavior of microtubules in solution can be strongly modified by interactions with walls or other structures. We examine here a microtubule growth model where the increase in size of the plus-end is perturbed by collisions with other microtubules. We show that such a simple mechanism of constrained growth can induce ordered structures and patterns from an initially isotropic and homogeneous suspension. First, microtubules self-organize locally in randomly oriented domains that grow and compete with each other. By imposing even a weak orientation bias, external forces like gravity or cellular boundaries may bias the domain distribution eventually leading to a macroscopic sample orientation.Comment: Submitted to Biophysical Journa

Vergleich von Strategien zum Clustern von Daten mit fehlenden Werten

Die klassischen Methoden zur Clusteranalyse wurden entwickelt, um auf vollständigen Daten Analysen durchzuführen. Oft fehlen aber in Daten einzelne Werte - systematisch oder unsystematisch -, z.B. infolge der Probleme bei der Datenerfassung, Datenübertragung, Datenbereinigung oder weil Daten aus unterschiedlichen Quellen stammen. Demzufolge können die traditionellen Clusteringmethoden zur Analyse solcher Daten nicht ohne weiteres angewendet werden. Im Rahmen dieses Beitrags werden unterschiedliche Strategien zum Umgang mit fehlenden Werten in Daten für das Clusteringproblem vorgestellt, analysiert und miteinander verglichen. Dabei wird das besondere Augenmerk auf die Untersuchung der Leistungsfähigkeit dieser Verfahren in Abhängigkeit von den Ausfallmechanismen, die den fehlenden Werten zugrundeliegen, und von dem Anteil fehlender Werte in Daten gelegt

Design considerations for M&S software

International audienceThe development of M&S products often seems to be driven by need: people start coding because they are interested in either a concrete simulation study, or they are interested in a (single) research subject of M&S methodology. We claim that discussing, designing, developing, and comparing M&S products should be based on software engineering concepts. We shortly introduce some of these engineering concepts and discuss how these relate to the M&S domain. By describing two examples, OSA and JAMES II, we illustrate that reuse might play an important role in the development of high quality M&S products as the examples allow reuse on the level of models and scenarios, on the level of "simulation studies", of algorithms (e.g., reuse of event queues, random number generators), across hardware architectures / operating systems, and of analysis tools

2-Aza­niumylcarba-closo-dodeca­borate ethanol monosolvate

Two formula units of the title compound, 2-H3N-closo-1-CB11H11·CH3CH2OH or CH14B11N·C2H5OH, form a ring motif of R 4 2(8) type in the solid state that surrounds a crystallographic center of symmetry. The ring motif is a result of N—H⋯O hydrogen bonds. In contrast to many structures of {closo-1-CB11} clusters, the assignment of the position of the cluster C atom in the structure of the title compound is unambigious. The relatively long B—N bond length [1.5396 (10) Å] documents the absence of any B—N π-inter­action in the title compound although this was observed for a related 2-amino­carba-closo-dodeca­borate

A survey on parallel and distributed Multi-Agent Systems

International audienceSimulation has become an indispensable tool for researchers to explore systems without having recourse to real experiments. Depending on the characteristics of the modeled system, methods used to represent the system may vary. Multi-agent systems are, thus, often used to model and simulate complex systems. Whatever modeling type used, increasing the size and the precision of the model increases the amount of computation, requiring the use of parallel systems when it becomes too large. In this paper, we focus on parallel platforms that support multi-agent simulations. Our contribution is a survey on existing platforms and their evaluation in the context of high performance computing. We present a qualitative analysis, mainly based on platform properties, then a performance comparison using the same agent model implemented on each platform

Alignment between PIN1 Polarity and Microtubule Orientation in the Shoot Apical Meristem Reveals a Tight Coupling between Morphogenesis and Auxin Transport

Morphogenesis during multicellular development is regulated by intercellular signaling molecules as well as by the mechanical properties of individual cells. In particular, normal patterns of organogenesis in plants require coordination between growth direction and growth magnitude. How this is achieved remains unclear. Here we show that in Arabidopsis thaliana, auxin patterning and cellular growth are linked through a correlated pattern of auxin efflux carrier localization and cortical microtubule orientation. Our experiments reveal that both PIN1 localization and microtubule array orientation are likely to respond to a shared upstream regulator that appears to be biomechanical in nature. Lastly, through mathematical modeling we show that such a biophysical coupling could mediate the feedback loop between auxin and its transport that underlies plant phyllotaxis

A novel, cellulose synthesis inhibitory action of ancymidol impairs plant cell expansion

The co-ordination of cell wall synthesis with plant cell expansion is an important topic of contemporary plant biology research. In studies of cell wall synthesis pathways, cellulose synthesis inhibitors are broadly used. It is demonstrated here that ancymidol, known as a plant growth retardant primarily affecting gibberellin biosynthesis, is also capable of inhibiting cellulose synthesis. Its ability to inhibit cellulose synthesis is not related to its anti-gibberellin action and possesses some unique features never previously observed when conventional cellulose synthesis inhibitors were used. It is suggested that ancymidol targets the cell wall synthesis pathway at a regulatory step where cell wall synthesis and cell expansion are coupled. The elucidation of the ancymidol target in plant cells could potentially contribute to our understanding of cell wall synthesis and cell expansion control

Markov chain simulation with fewer random samples

We propose an accelerated CTMC simulation method that is exact in the sense that it produces all of the transitions involved. We call our method Path Sampling Simulation as it samples from the distribution of trajectories and the distribution of time given some particular trajectory. Sampling from the trajectory space rather than the transition space means that we need to generate fewer random numbers, which is an operation that is typically computationally expensive. Sampling from the time distribution involves approximating the exponential distributions that govern the sojourn times with a geometric distribution. A proper selection for the approximation parameters can ensure that the stochastic process simulated is almost identical to the simulation of the original Markov chain. Our approach does not depend on the properties of the system and it can be used as an alternative to more efficient approaches when those are not applicable. 1

Cellulose Biosynthesis Inhibitors: Comparative Effect on Bean Cell Cultures

The variety of bioassays developed to evaluate different inhibition responses for cellulose biosynthesis inhibitors makes it difficult to compare the results obtained. This work aims (i) to test a single inhibitory assay for comparing active concentrations of a set of putative cellulose biosynthesis inhibitors and (ii) to characterize their effect on cell wall polysaccharides biosynthesis following a short-term exposure. For the first aim, dose-response curves for inhibition of dry-weight increase following a 30 days exposure of bean callus-cultured cells to these inhibitors were obtained. The compound concentration capable of inhibiting dry weight increase by 50% compared to control (I50) ranged from subnanomolar (CGA 325′615) to nanomolar (AE F150944, flupoxam, triazofenamide and oxaziclomefone) and micromolar (dichlobenil, quinclorac and compound 1) concentrations. In order to gain a better understanding of the effect of the putative inhibitors on cell wall polysaccharides biosynthesis, the [14C]glucose incorporation into cell wall fractions was determined after a 20 h exposure of cell suspensions to each inhibitor at their I50 value. All the inhibitors tested decreased glucose incorporation into cellulose with the exception of quinclorac, which increased it. In some herbicide treatments, reduction in the incorporation into cellulose was accompanied by an increase in the incorporation into other fractions. In order to appreciate the effect of the inhibitors on cell wall partitioning, a cluster and Principal Component Analysis (PCA) based on the relative contribution of [14C]glucose incorporation into the different cell wall fractions were performed, and three groups of compounds were identified. The first group included quinclorac, which increased glucose incorporation into cellulose; the second group consisted of compound 1, CGA 325′615, oxaziclomefone and AE F150944, which decreased the relative glucose incorporation into cellulose but increased it into tightly-bound cellulose fractions; and the third group, comprising flupoxam, triazofenamide and dichlobenil, decreased the relative glucose incorporation into cellulose and increased it into a pectin rich fraction