1,191 research outputs found
A distributed amplifier system for bilayer lipid membrane (BLM) arrays with noise and individual offset cancellation
No full textLipid bilayer membrane (BLM) arrays are required for high throughput analysis, for example drug screening or advanced DNA sequencing. Complex microfluidic devices are being developed but these are restricted in terms of array size and structure or have integrated electronic sensing with limited noise performance. We present a compact and scalable multichannel electrophysiology platform based on a hybrid approach that combines integrated state-of-the-art microelectronics with low-cost disposable fluidics providing a platform for high-quality parallel single ion channel recording. Specifically, we have developed a new integrated circuit amplifier based on a novel noise cancellation scheme that eliminates flicker noise derived from devices under test and amplifiers. The system is demonstrated through the simultaneous recording of ion channel activity from eight bilayer membranes. The platform is scalable and could be extended to much larger array sizes, limited only by electronic data decimation and communication capabilities
Population balance equation for collisional breakage: A new numerical solution scheme and its convergence
No full text<p><strong>Synopsis</strong></p><p>These files represent a reference implementation of the finite volume method for the solution of the discretised population balance equation for collisional breakge. Several test cases are provided. </p><p>Implementation language: Matlab (FORTRAN-derivative)</p><p>The method and its capabilities are described in<br>P. Kuswah, A. Das, J. Saha, A. Bück, "Population balance equation for collisional breakage: A new numerical solution scheme and its convergence", Communications in Nonlinear Science and Numerical Simulation, vol 121, 107244, 2023. </p><p>If the method or code is used in other work, cite<br>P. Kuswah, A. Das, J. Saha, A. Bück, "Population balance equation for collisional breakage: A new numerical solution scheme and its convergence", Communications in Nonlinear Science and Numerical Simulation, vol 121, 107244, 2023. </p><p><strong>License</strong></p><p>The implementation is distributed as-is without taking over any responsibility by the authors or their affiliated institutions for potential damages resulting from its use. </p><p>The implementation is made available under Creative Commons Attribution Non Commercial No Derivatives 4.0 International. </p><p><strong>Folder contents</strong></p><p>The reference implementations are provided for the cases discussed in the mentioned publication. The implementation of the finite volume methode is stored in the sub-folders "DPBE_Brk", calling sequence and required initialisiations are given in the files "Main_FPT.m".</p><p>In case of problems, bug reports, feel free to contact any author.</p><p>On behalf of all authors,</p><p>Andreas Bück<br>Institute of Particle Technology<br>Friedrich-Alexander-Universität Erlangen-Germany<br>[email protected]<br>www.spg.forschung.fau.de</p><p> </p><p>v1.0: 31.08.2023</p>
Semi-abelian analogues of Schanuel conjecture and applications
No full textIn this article we study semi-abelian analogues of Schanuel conjecture. As showed by the first author, Schanuel conjecture is equivalent to the Generalized Period conjecture applied to 1-motives without abelian part. Extending her methods, the second, the third and the fourth authors have introduced the abelian analogue of Schanuel conjecture as the Generalized Period conjecture applied to 1-motives without toric part. As a first result of this paper, we define the semi-abelian analogue of Schanuel conjecture as the Generalized Period conjecture applied to 1-motives. C. Cheng et al. proved that Schanuel conjecture implies the algebraic independence of the values of the iterated exponential and the values of the iterated logarithm, answering a question of M. Waldschmidt. The second, the third and the fourth authors have investigated a similar question in the setup of abelian varieties: the Weak Abelian Schanuel conjecture implies the algebraic independence of the values of the iterated abelian exponential and the values of an iterated generalized abelian logarithm. The main result of this paper is that a Relative Semi-abelian conjecture implies the algebraic independence of the values of the iterated semi-abelian exponential and the values of an iterated generalized semi-abelian logarithm
Internet-of-Forensic (IoF): A blockchain based digital forensics framework for IoT applications
No full textDigital forensic in Internet-of-Thing (IoT) paradigm is critical due to its heterogeneity and lack of transparency of evidence processing. Moreover, cross-border legalization makes a hindrance in such process pertaining to the cloud forensic issues. This urges a forensic framework for IoT which provides distributed computing, decentralization, and transparency of forensic investigation of digital evidences in cross-border perspectives. To this end, we propose a framework for IoT forensics that addresses the above mentioned issues. The proposed solution called Internet-of-Forensics (IoF) considers a blockchain tailored IoT framework for digital forensics. It provides a transparent view of the investigation process that involves all the stakeholders (e.g., heterogeneous devices, and cloud service providers) in a single framework. It uses blockchain-based case chain to deal with the investigation process including chain-of-custody and evidence chain. Consensus is used for consortium to solve the problems of cross-border legalization. This is also beneficial for a transparent and ease of forensic reference. The programmable lattice-based cryptographic primitives produce reduced complexities. It shows benefits for power-aware devices and puts an add-on to the novelty of the presented idea. IoF is generic; hence, it can be used by autonomous security operation centers, cyber-forensic investigators and manually initiated evidences under chain-of-custody for man-made crimes. Security services are assured as required by the framework. IoF is experimented and compared with the other state-of-the-art frameworks. The outcomes and analysis prove the efficiency of IoF concerning complexity, time consumption, memory and CPU utilization, gas consumption, and energy analysis
Nucleosynthesis in heavy-ion collisions at the LHC via the Saha equation
No full textThe production of light (anti-)(hyper-)nuclei in heavy-ion collisions at the LHC is considered in the framework of the Saha equation, making use of the analogy between the evolution of the early universe after the Big Bang and that of “Little Bangs” created in the lab. Assuming that disintegration and regeneration reactions involving light nuclei proceed in relative chemical equilibrium after the chemical freeze-out of hadrons, their abundances are determined through the famous cosmological Saha equation of primordial nucleosynthesis and show no exponential dependence on the temperature typical for the thermal model. A quantitative analysis, performed using the hadron resonance gas model in partial chemical equilibrium, shows agreement with experimental data of the ALICE collaboration on d, 3He, HΛ3, and 4He yields for a very broad range of temperatures at T≲155 MeV. The presented picture is supported by the observed suppression of resonance yields in central Pb–Pb collisions at the LHC. Keywords: Light (anti-)(hyper-)nuclei production, Saha equation, Partial chemical equilibrium
Meghnad Saha: his life in science and politics
No full textThis biography is a short yet comprehensive overview of the life of Meghnad Saha, the mastermind behind the frequently used Saha equations and a strong contributor to the foundation of science in India. The author explores the lesser known details behind the man who played a major role in building scientific institutions in India, developed the breakthrough theory of thermal ionization, and whose fervor about India’s rapid progress in science and technology, along with concern for uplifting his countrymen and optimizing resources, led him to eventually enter politics and identify the mismanagement of many programs of national importance to Parliament. This book is free of most academic technicalities, so that the reader with general scientific knowledge can read and understand it easily. One interested only in Saha’s contribution to physics can pick up just that part and read it. Conversely, the average reader may skip the technical chapters, and read the book without loss of continuity or generality to still get a coherent picture. This work touches on all aspects of Saha’s multidimensional personality, which overflows in the pages of his periodical, Science and Culture,as well as his many speeches, debates and discussions in Parliament, all of which is appropriately conveyed in this book
Frontiers of metal-coordinating drug design
No full textIntroduction: The occurrence of metal ions in biomolecules is required to exert vital cellular functions. Metal-containing biomolecules can be modulated by small-molecule inhibitors targeting their metal-moiety. As well, the discovery of cisplatin ushered the rational discovery of metal-containing-drugs. The use of both drug types exploiting metal–ligand interactions is well established to treat distinct pathologies. Therefore, characterizing and leveraging metal-coordinating drugs is a pivotal, yet challenging, part of medicinal chemistry. Area covered: Atomic-level simulations are increasingly employed to overcome the challenges met by traditional drug-discovery approaches and to complement wet-lab experiments in elucidating the mechanisms of drugs’ action. Multiscale simulations, allow deciphering the mechanism of metal-binding inhibitors and metallo-containing-drugs, enabling a reliable description of metal-complexes in their biological environment. In this compendium, the authors review selected applications exploiting the metal–ligand interactions by focusing on understanding the mechanism and design of (i) inhibitors targeting iron and zinc-enzymes, and (ii) ruthenium and gold-based anticancer agents targeting the nucleosome and aquaporin protein, respectively. Expert opinion: The showcased applications exemplify the current role and the potential of atomic-level simulations and reveal how their synergic use with experiments can contribute to uncover fundamental mechanistic facets and exploit metal–ligand interactions in medicinal chemistry
Preference Heterogeneity in Experiments: Comparing the Field and Lab
No full textEconomists recognize that preferences can differ across individuals. We examine the strengths and weaknesses of lab and field experiments to detect differences in preferences that are associated with standard, observable characteristics of the individual. We consider preferences over risk and time, two fundamental concepts of economics. Our results provide striking evidence that there are good reasons to conduct field experiments. The lab fails to detect preference heterogeneity that is present in the field, obviously due to the demographic homogeneity of the lab. There are also differences in treatment effects measured in the lab and the field that can be traced to interactions between treatment and demographic effects. These can only be detected and controlled for properly in the field data. Thus one cannot simply claim, without additional empirical argument or assumption, that treatment effects estimated in the lab are reliable.
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