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A fast and straightforward method to prototype microfluidic chip systems for dead-volume-free hyphenation to electrospray-ionisation mass spectrometry is presented. The developed approach based on liquid-phase lithography provides an inexpensive and reliable access to microfluidic chips for MS coupling which can be manufactured in any laboratory with low technical demands. The rapid prototyping approach enables the seamless integration of capillaries serving as electrospray emitters with negligible dead volume. The high versatility of the presented prototyping method and the applicability of a variety of chip-based devices in different fields of lab-on-a-chip technology are established for analytical separations by means of chip-electrochromatography-MS and for continuous-flow synthesis using microreactor technology with MS detection. [ABSTRACT FROM AUTHOR]

Distance-based methods for measuring spatial concentration of industries have received an increasing popularity in the spatial econometrics community. However, a limiting factor for using these methods is their computational complexity since both their memory requirements and running times are in $${\mathcal {O}}(n^2)$$ . In this paper, we present an algorithm with constant memory requirements and shorter running time, enabling distance-based methods to deal with large data sets. We discuss three recent distance-based methods in spatial econometrics: the D&O-Index by Duranton and Overman (Rev Econ Stud 72(4):1077-1106, ), the M-function by Marcon and Puech (J Econ Geogr 10(5):745-762, ) and the Cluster-Index by Scholl and Brenner (Reg Stud (ahead-of-print):1-15, ). Finally, we present an alternative calculation for the latter index that allows the use of data sets with millions of firms. [ABSTRACT FROM AUTHOR]

Rising numbers of psychoactive tryptamine derivatives have become available on the drug market over the last decade, making these naturally occurring or synthetically manufactured compounds highly relevant for forensic analyses. One of these compounds is 5-methoxy- N,N -dimethyltryptamine (5-MeO-DMT), a constituent of the dried poison of Incilius alvarius (Colorado River toad), which has a history of ritual and/or recreational use. Still, comprehensive and validated qualitative as well as quantitative analytical data on the psychoactive components of this poison are scarce. In this study, samples of the poison of Incilius alvarius were collected from live toads in the Sonoran Desert, Arizona (USA), and analyzed with a set of complementary methods. Acetone/water (70/30, v/v) proved to be the solvent of choice for the extraction of tryptamine derivatives. Trace compounds were enriched, and overload with 5-MeO-DMT was prevented by chromatographic separation of 5-MeO-DMT prior to qualitative analyses. The method for quantification was validated. Attenuated total reflection–Fourier transform infrared spectroscopy was suitable to identify 5-MeO-DMT as the main tryptamine in samples of the poison. The combined evaluation of analytical data gained from gas chromatography–mass spectrometry (GC–MS), high-performance liquid chromatography–quadrupole time-of-flight high-resolution MS (HPLC–qToF-HRMS) and HPLC–MS-MS confirmed the presence of 5-MeO-DMT, 5-MeO- N -methyltryptamine, 5-MeO-tryptamine, 5-MeO-tryptophol, 2-(5-methoxy-1 H -indol-3-yl)-acetic-acid (5-MIAA), 5-HO- N -methyltryptamine, bufotenin, DMT and tryptophan. For the first time, 5-MeO-tryptamine and two positional isomers of hydroxylated MeO-DMT were detected in the poison of Incilius alvarius. The tryptamine present in the highest concentrations was 5-MeO-DMT (mean ± SD: 410,000 ± 30,000 μg/g). Mean concentrations of 5-MeO-tryptamine (490 ± 260 μg/g), 5-HO- N -methyltryptamine (270 ± 120 μg/g), bufotenin (2,800 ± 1,900 μg/g) and DMT (250 ± 80 μg/g) showed a relatively high variability between individual samples. The comprehensive analytical reference data of Incilius alvarius poison presented here might prove useful for forensic chemists. [ABSTRACT FROM AUTHOR]

Abstract: We present status and results of AstroGrid-D, a joint effort of astrophysicists and computer scientists to employ grid technology for scientific applications. AstroGrid-D provides access to a network of distributed machines with a set of commands as well as software interfaces. It allows simple use of computer and storage facilities and to schedule or monitor compute tasks and data management. It is based on the Globus Toolkit middleware (GT4). Chapter 1 describes the context which led to the demand for advanced software solutions in Astrophysics, and we state the goals of the project. We then present characteristic astrophysical applications that have been implemented on AstroGrid-D in chapter 2. We describe simulations of different complexity, compute-intensive calculations running on multiple sites (Section ), and advanced applications for specific scientific purposes (Section ), such as a connection to robotic telescopes (Section ). We can show from these examples how grid execution improves e.g. the scientific workflow. Chapter 3 explains the software tools and services that we adapted or newly developed. Section is focused on the administrative aspects of the infrastructure, to manage users and monitor activity. Section characterises the central components of our architecture: The AstroGrid-D information service to collect and store metadata, a file management system, the data management system, and a job manager for automatic submission of compute tasks. We summarise the successfully established infrastructure in chapter 4, concluding with our future plans to establish AstroGrid-D as a platform of modern e-Astronomy. [ABSTRACT FROM AUTHOR]