Modular Ion Mobility Calibrants for Organometallic Anions Based on Tetraorganylborate Salts

Organometallics are widely used in catalysis and synthesis. Their analysis relies heavily on mass spectrometric methods, among which traveling-wave ion mobility spectrometry (TWIMS) has gained increasing importance. Collision cross sections (CCS) obtainable by TWIMS significantly aid the structural characterization of ions in the gas phase, but for organometallics, their accuracy has been limited by the lack of appropriate calibrants. Here, we propose tetraorganylborates and their alkali-metal bound oligomers [Mn–1(BR4)n]− (M = Li, Na, K, Rb, Cs; R = aryl, Et; n = 1–6) as calibrants for electrospray ionization (ESI) TWIMS. These species chemically resemble typical organometallics and readily form upon negative-ion mode ESI of solutions of alkali-metal tetraorganylborates. By combining different tetraorganylborate salts, we have generated a large number of anions in a modular manner and determined their CCS values by drift-tube ion mobility spectrometry (DTIMS) (DTCCSHe = 81–585, DTCCSN2 = 130–704 Å2). In proof-of-concept experiments, we then applied these DTCCS values to the calibration of a TWIMS instrument and analyzed phenylcuprate and argentate anions, [Lin–1MnPh2n]− and [MnPhn+1]− (M = Cu, Ag), as prototypical reactive organometallics. The TWCCSN2 values derived from TWIMS measurements are in excellent agreement with those determined by DTIMS (<2% relative difference), demonstrating the effectiveness of the proposed calibration scheme. Moreover, we used theoretical methods to predict the structures and CCS values of the anions considered. These predictions are in good agreement with the experimental results and give further insight into the trends governing the assembly of tetraorganylborate, cuprate, and argentate oligomers

funcX: A Federated Function Serving Fabric for Science

Exploding data volumes and velocities, new computational methods and platforms, and ubiquitous connectivity demand new approaches to computation in the sciences. These new approaches must enable computation to be mobile, so that, for example, it can occur near data, be triggered by events (e.g., arrival of new data), be offloaded to specialized accelerators, or run remotely where resources are available. They also require new design approaches in which monolithic applications can be decomposed into smaller components, that may in turn be executed separately and on the most suitable resources. To address these needs we present funcX---a distributed function as a service (FaaS) platform that enables flexible, scalable, and high performance remote function execution. funcX's endpoint software can transform existing clouds, clusters, and supercomputers into function serving systems, while funcX's cloud-hosted service provides transparent, secure, and reliable function execution across a federated ecosystem of endpoints. We motivate the need for funcX with several scientific case studies, present our prototype design and implementation, show optimizations that deliver throughput in excess of 1 million functions per second, and demonstrate, via experiments on two supercomputers, that funcX can scale to more than more than 130000 concurrent workers.Comment: Accepted to ACM Symposium on High-Performance Parallel and Distributed Computing (HPDC 2020). arXiv admin note: substantial text overlap with arXiv:1908.0490

A security architecture for personal networks

Abstract Personal Network (PN) is a new concept utilizing pervasive computing to meet the needs of the user. As PNs edge closer towards reality, security becomes an important concern since any vulnerability in the system will limit its practical use. In this paper we introduce a security architecture designed for PNs. Our aim is to use secure but lightweight mechanisms suitable for resource constrained devices and wireless communication. We support pair-wise keys for secure cluster formation and use group keys for securing intra-cluster communication. In order to analyze the performance of our proposed mechanisms, we carry out simulations using ns-2. The results show that our mechanisms have a low overhead in terms of delay and energy consumption

A DYNAMIC CONTENT MANAGEMENT SYSTEM FOR THE VISUALIZATION OF CULTURAL INFORMATION; THE CASE OF THE STATE CONSERVATORY OF THESSALONIKI, GR

Although there are several attempts of embedding static content in events’ brochures and posters, the increasing need for flexibility and versatility of the content, leads to the development of a mobile application with an in-app dynamic content management system. In this context, DigiOrch is an ongoing research program where, a Content Management System is developed to organize all the digital material and maintain the appropriate connection to the analogical markers. Furthermore, a mobile application is developed that lev-erages this system using in app dynamic modules, which, by utilizing the augmented reality technology, presents multimedia data such as texts, photos, videos, and 3D Models to the end-user by “superimposing” them on mobile devices screen, providing extra additional information on any valid smart-leaflet.The overall workflow of the in-app Dynamic Content Management System (DCMS) can be described as a group of modules that managing and copying content files from a remote infrastructure such as an ftp server or a local resource if network is missing, to the mobile device’s file system.The in-app DCMS consists of 4 modules: The first module is the parser, which is responsible for reading a downloaded *.json file and creating content-linked objects. The second module is the download module which is responsible for downloading the overall content by iterating the content-linked objects, created by the previous module. The third module le is the update module that, by iterating the initial content file and the local file system, suggests whether a content update is necessary. The fourth module is the loading module, which is responsible for fetching the content on runtime to fill the content-holding components, such as 3D Models and UI photo galleries, of the AR scenes on runtime.</p

Aristotle University of Thessaloniki Library & Information Centre: A new-old library

The Aristotle University of Thessaloniki Library and Information Centre (AUTh Library) is a rather new library, 90 years old. Yet, its collections go back till the 10th century AD thanks to donations by professors, donors and other benefactors. This paper shortly presents the history of the AUTh Library

Books

Portrait of Don Craib In Search of Truth - A Portrait of Don Craib: By E.B. Adams pp. xi + 123. Illustrated.London and New York: Royal Society of Medicine Services. 1990.Internal medicine Harrison's Principles of Internal Medicine. 12th ed. Bd. by ].D. Wilson, E. Braunwald, K.]. Isselbacher, et al. pp. xxx + 2208. Illustrated. USA: McGraw-Hill. 1991.HPV and cervical cancer Human Papillomavirus and Cervical Cancer. Ed. by N. Munoz, F. X. Bosch and O. M. Jensen. Pp. xii + 155. Illustrated. France: International Agency for Research on Cancer. 1989

Case variation in coordination: Danish vs. Faroese

This paper is primarily concerned with inter- and intra-individually variable case-form mismatches inside coordinate determiner phrases (CoDPs). For English, the phenomenon is both socially salient (e.g., O'Conner &amp; Kellerman 2009, among many others) and well studied (Angermeyer &amp; Singler 2003, Quinn 2005, Grano 2006, Parrott 2007: Ch. 6). The most prominent theory of (default) case (Sch&uuml;tze 2001, incorporating Johannessen 1998) explains English variation in CoDPs mostly with parameterized syntactic mechanisms. The parametric theory does not make clear cross-linguistic predictions, and accordingly there has been little cross-linguistic investigation of case variation in CoDPs. This paper therefore has two main purposes. The first is to argue for a theory of (default) case (Parrott 2007, 2009a, following Emonds 1986, and incorporating McFadden 2004, 2007) within the Distributed Morphology (DM) framework (Halle &amp; Marantz 1993, Embick &amp; Noyer 2007). In contrast with the parametric theory, the DM theory makes testable cross-linguistic predictions that, inter alia, connect the (non) attestation of case mismatches in CoDPs with Germanic case typology. Thus, the paper&rsquo;s second purpose is to present some results from investigations, utilizing diverse empirical methods, into case variation in CoDPs for Danish and Faroese. These results are consistent with predictions made by the DM theory