{1-[1-(3-Carboxy­propanamido)eth­yl]-1′,2-bis­(diphenyl­phosphino)ferrocene-κ2 P,P′}dichloridoplatinum(II) dichloro­methane 1.25-solvate

The dinuclear title compound, [FePtCl2(C17H14P)(C23H23NO3P)]·1.25CH2Cl2, has a slightly distorted cis-PtCl2P2 square-planar geometry around the Pt atom, and the ferrocenylphosphine ligands are staggered at an angle of 29.4 (2)° about Pt. In the crystal structure, the complex forms centrosymmetric dimers via two strong inter­molecular O—H⋯O bonds resulting in R 2 2(8) rings. A weak intra­molecular N—H⋯Cl bond leads to an S(8) motif. The solvent is highly disordered and has not been modelled with discrete atoms

Runtime virtual machine recontextualization for clouds

We introduce and define the concept of recontextualization for cloud applications by extending contextualization, i.e. the dynamic configuration of virtual machines (VM) upon initialization, with autonomous updates during runtime. Recontextualization allows VM images and instances to be dynamically re-configured without restarts or downtime, and the concept is applicable to all aspects of configuring a VM from virtual hardware to multi-tier software stacks. Moreover, we propose a runtime cloud recontextualization mechanism based on virtual device management that enables recontextualization without the need to customize the guest VM. We illustrate our concept and validate our mechanism via a use case demonstration: the reconfiguration of a cross-cloud migratable monitoring service in a dynamic cloud environment. We discuss the details of the interoperable recontextualization mechanism, its architecture and demonstrate a proof of concept implementation. A performance evaluation illustrates the feasibility of the approach and shows that the recontextualization mechanism performs adequately with an overhead of 18% of the total migration time

Metastable Dynamics above the Glass Transition

The element of metastability is incorporated in the fluctuating nonlinear hydrodynamic description of the mode coupling theory (MCT) of the liquid-glass transition. This is achieved through the introduction of the defect density variable $n$ into the set of slow variables with the mass density $\rho$ and the momentum density ${\bf g}$. As a first approximation, we consider the case where motions associated with $n$ are much slower than those associated with $\rho$. Self-consistently, assuming one is near a critical surface in the MCT sense, we find that the observed slowing down of the dynamics corresponds to a certain limit of a very shallow metastable well and a weak coupling between $\rho$ and $n$. The metastability parameters as well as the exponents describing the observed sequence of time relaxations are given as smooth functions of the temperature without any evidence for a special temperature. We then investigate the case where the defect dynamics is included. We find that the slowing down of the dynamics corresponds to the system arranging itself such that the kinetic coefficient $\gamma_v$ governing the diffusion of the defects approaches from above a small temperature-dependent value $\gamma^c_v$.Comment: 38 pages, 14 figures (6 figs. are included as a uuencoded tar- compressed file. The rest is available upon request.), RevTEX3.0+eps

ACTiCLOUD: Enabling the Next Generation of Cloud Applications

Despite their proliferation as a dominant computing paradigm, cloud computing systems lack effective mechanisms to manage their vast amounts of resources efficiently. Resources are stranded and fragmented, ultimately limiting cloud systems' applicability to large classes of critical applications that pose non-moderate resource demands. Eliminating current technological barriers of actual fluidity and scalability of cloud resources is essential to strengthen cloud computing's role as a critical cornerstone for the digital economy. ACTiCLOUD proposes a novel cloud architecture that breaks the existing scale-up and share-nothing barriers and enables the holistic management of physical resources both at the local cloud site and at distributed levels. Specifically, it makes advancements in the cloud resource management stacks by extending state-of-the-art hypervisor technology beyond the physical server boundary and localized cloud management system to provide a holistic resource management within a rack, within a site, and across distributed cloud sites. On top of this, ACTiCLOUD will adapt and optimize system libraries and runtimes (e.g., JVM) as well as ACTiCLOUD-native applications, which are extremely demanding, and critical classes of applications that currently face severe difficulties in matching their resource requirements to state-of-the-art cloud offerings

Moment Closure - A Brief Review

Moment closure methods appear in myriad scientific disciplines in the modelling of complex systems. The goal is to achieve a closed form of a large, usually even infinite, set of coupled differential (or difference) equations. Each equation describes the evolution of one "moment", a suitable coarse-grained quantity computable from the full state space. If the system is too large for analytical and/or numerical methods, then one aims to reduce it by finding a moment closure relation expressing "higher-order moments" in terms of "lower-order moments". In this brief review, we focus on highlighting how moment closure methods occur in different contexts. We also conjecture via a geometric explanation why it has been difficult to rigorously justify many moment closure approximations although they work very well in practice.Comment: short survey paper (max 20 pages) for a broad audience in mathematics, physics, chemistry and quantitative biolog

Cloud computing and RESERVOIR project

The support for complex services delivery is becoming a key point in current internet technology. Current trends in internet applications are characterized by on demand delivery of ever growing amounts of content. The future internet of services will have to deliver content intensive applications to users with quality of service and security guarantees. This paper describes the RESERVOIR project and the challenge of a reliable and effective delivery of services as utilities in a commercial scenario. It starts by analyzing the needs of a future infrastructure provider and introducing the key concept of a service oriented architecture that combines virtualisation-aware grid with grid-aware virtualisation, while being driven by business service management. This article will then focus on the benefits and the innovations derived from the RESERVOIR approach. Eventually, a high level view of RESERVOIR general architecture is illustrated

Competitive Substitution and Electron Transfer in Reactions between Haloamminegold(III) and Halocyanoaurate(III) Complexes and Thiocyanate

SynopsisReduction of gold(III) complexes by thiocyanate takes place via rapid substitutions at gold(III), followed by intramolecular, slower reductive elimination through attack by outer-sphere thiocyanate. A transition state with an S−S interaction between attacking and coordinated thiocyanate is suggested for the redox process.AbstractAbstract ImageKinetics for reactions between thiocyanate and trans-Au(CN)2Cl2-, trans-Au(CN)2Br2-, and trans-Au(NH3)2Cl2+ in an acidic, 1.00 M perchlorate aqueous medium have been studied by use of conventional and diode-array UV/vis spectroscopy and high-pressure and sequential-mixing stopped-flow spectrophotometry. Initial, rapid formation of mixed halide−thiocyanate complexes of gold(III) is followed by slower reduction to Au(CN)2- and Au(NH3)2+, respectively. This is an intermolecular process, involving attack on the complex by outer-sphere thiocyanate. Second-order rate constants at 25.0 °C for reduction of trans-Au(CN)2XSCN- are (6.9 ± 1.1) × 104 M-1 s-1 for X = Cl and (3.1 ± 0.7) × 103 M-1 s-1 for X = Br. For reduction of trans-Au(CN)2(SCN)2- the second-order rate constant at 25.0 °C is (3.1 ± 0.1) × 102 M-1 s-1 and the activation parameters are ΔH⧧ = (55 ± 3) × 102 kJ mol-1, ΔS⧧ = (−17.8 ± 0.8) J K-1 mol-1, and ΔV⧧ = (−4.6 ± 0.5) cm3 mol-1. The activation volume for substitution of one chloride on trans-Au(NH3)2Cl2+ is (−4.5 ± 0.5) cm3 mol-1, and that for reduction of trans-Au(NH3)2(SCN)2+ (4.6 ± 0.9) cm3 mol-1. The presence of π-back-bonding cyanide ligands stabilizes the transition states for both substitution and reductive elimination reactions compared to ammine. In particular, complexes trans-Au(CN)2XSCN- with an unsymmetric electron distribution along the X−Au−SCN axis are reduced rapidly. The observed entropies and volumes of activation reflect large differences in the transition states for the reductive elimination and substitution processes, respectively, the former being more loosely bound, more sensitive to solvational changes, and probably not involving any large changes in the inner coordination sphere. A transition state with an S−S interaction between attacking and coordinated thiocyanate is suggested for the reduction. The stability constants for formation of the very short-lived complex trans-Au(CN)2(SCN)2- from trans-Au(CN)2X(SCN)- (X = Cl, Br) by replacement of halide by thiocyanate prior to reduction can be calculated from the redox kinetics data to be KCl,2 = (3.8 ± 0.8) × 104 and KBr,2 = (1.1 ± 0.4) × 102

Platinum Interference with siRNA Non-seed Regions Fine-Tunes Silencing Capacity

Knowledge concerning the molecular mechanisms governing the influence of non-coding RNAs on protein production has emerged rapidly during the past decade. Today, two main research areas can be identified, one oriented toward the use of artificially introduced siRNAs for manipulation of gene expression, and the other one focused on the function of endogenous miRNAs. In both cases, the active molecule consists of a 20-nucleotide-long RNA duplex. In the siRNA case, improved systemic stability is of central interest for its further development toward clinical applications. With respect to miRNA processing and function, understanding its influence on mRNA targeting and the silencing ability of individual miRNAs, e.g., under pathological conditions, remains a scientific challenge. In the present study, a model system is presented where the influence of the two clinically used anticancer drugs, cisplatin and oxaliplatin, on siRNA's silencing capacity has been evaluated. More specifically, siRNAs targeting the 3' UTR region of Wnt-5a mRNA (NM_003352) were constructed, and the biologically active antisense RNA strand was pre-platinated. Platinum adducts were detected and characterized by a combination of gel electrophoresis and MALDI-MS techniques, and the silencing capacity was evaluated in cellular luciferase-expressing systems using HB2 cells. Data show that platination of the antisense strand of the siRNAs results in adducts with protection against hydrolytic cleavage in the proximity of the platination sites, i.e., with altered degradation patterns compared to native RNAs. The MALDI-MS method was successfully used to further identify and characterize platinated RNA, with the naturally occurring platinum isotopic patterns serving as sensitive fingerprints for metalated sites. Expression assays all confirm biological activity of antisense-platinated siRNAs, here with platination sites located outside of the seed region. A significant reduction of silencing capacity was observed as a general trend, however. Of the two complexes studied, oxaliplatin exhibits the larger influence, thus indicating subtle differences between the abilities of cis- and oxaliplatin to interfere with si- and miRNA processing