A guide to time-resolved and parameter-free measures of spike train synchrony

Measures of spike train synchrony have proven a valuable tool in both experimental and computational neuroscience. Particularly useful are time-resolved methods such as the ISI- and the SPIKE-distance, which have already been applied in various bivariate and multivariate contexts. Recently, SPIKE-Synchronization was proposed as another time-resolved synchronization measure. It is based on Event-Synchronization and has a very intuitive interpretation. Here, we present a detailed analysis of the mathematical properties of these three synchronization measures. For example, we were able to obtain analytic expressions for the expectation values of the ISI-distance and SPIKE-Synchronization for Poisson spike trains. For the SPIKE-distance we present an empirical formula deduced from numerical evaluations. These expectation values are crucial for interpreting the synchronization of spike trains measured in experiments or numerical simulations, as they represent the point of reference for fully randomized spike trains.Comment: 8 pages, 4 figure

Protein stability in a proteomic perspective

Dissertation presented to obtain the Ph.D degree in BiochemistryThis work involved the identification and analysis of the properties of the most stable proteins present within proteomes, aiming at obtaining a general perspective of the factors that determine protein stability. As models we have focused on ensembles of proteins with high intrinsic stability, and for this purpose we have studied proteomes from the hyperthermophilic archaeon Sulfolobus solfataricus and Sulfurisphaera sp., whose properties were compared to those of the mesophilic bacterium Escherichia coli.(...

An Investment to Die For: From Life Insurance to Death Bonds, the Evolution and Legality of the Life Settlement Industry

Profiting from death may strike one as morally offensive, but the life settlement industry has created just such an opportunity. A life settlement is a transaction wherein an insured assigns the ownership interest (contract rights to the death benefit) of a life insurance policy to an investor for cash consideration. In other words, it is the sale of an economic interest in the death of the insured. As such, the industry has created a secondary market for what was once thought to be an illiquid asset: life insurance. While current market volatility makes an investment in death attractive, the life settlement industry is not without pitfalls. This Comment explores the evolution and legality of the industry as well as considerations for an individual contemplating a life settlement transaction

Design methods for integrated switching-mode power amplifiers

While a lot of time and resources have been placed into transceiver design, due to the pace of a conventional engineering design process, the design of a power amplifier is often completed using scattered resources; and not always in a methodological manner, and frequently even by an iterative trial and error process. In this thesis, a research question is posed which enables for the investigation of the possibility of streamlining the design flow for power amplifiers. After thorough theoretical investigation of existing power amplifier design methods and modelling, inductors inevitably used in power amplifier design were identified as a major drawback to efficient design, even when examples of inductors are packaged in design HIT-Kits. The main contribution of this research is engineering of an inductor design process, which in-effect contributes towards enhancing conventional power amplifiers. This inductance search algorithm finds the highest quality factor configuration of a single-layer square spiral inductor within certain tolerance using formulae for inductance and inductor parasitics of traditional single-π inductor model. Further contribution of this research is a set of algorithms for the complete design of switch-mode (Class-E and Class-F) power amplifiers and their output matching networks. These algorithms make use of classic deterministic design equations so that values of parasitic components can be calculated given input parameters, including required output power, centre frequency, supply voltage, and choice of class of operation. The hypothesis was satisfied for SiGe BiCMOS S35 process from Austriamicrosystems (AMS). Several metal-3 and thick-metal inductors were designed using the abovementioned algorithm and compared with experimental results provided by AMS. Correspondence was established between designed, experimental and EM simulation results, enabling qualification of inductors other than those with experimental results available from AMS by means of EM simulations with average relative errors of 3.7% for inductors and 21% for the Q factor at its peak frequency. For a wide range of inductors, Q-factors of 10 and more were readily experienced. Furthermore, simulations were performed for number of Class-E and Class-F amplifier configurations with HBTs with ft greater than 60 GHz and total emitter area of 96 μm² as driving transistors to complete the hypothesis testing. For the complete PA system design (including inductors), simulations showed that switch-mode power amplifiers for 50 Ω load at 2.4 GHz centre frequency can be designed using the streamlined method of this research for the output power of about 6 dB less than aimed. This power loss was expected, since it can be attributed to non-ideal properties of the driving transistor and Q-factor limitations of the integrated inductors, assumptions which the computations of the routine were based on. Although these results were obtained for a single micro-process, it was further speculated that outcome of this research has a general contribution, since streamlined method can be used with a much wider range of CMOS and BiCMOS processes, when low-gigahertz operating power amplifiers are needed. This theory was confirmed by means of simulation and fabrication in 180 nm BiCMOS process from IBM, results of which were also presented. The work presented here, was combined with algorithms for SPICE netlist extraction and the spiral inductor layout extraction (CIF and GDSII formats). This secondary research outcome further contributed to the completeness of the design flow. All the above features showed that the routine developed here is substantially better than cut-and-try methods for design of power amplifiers found in the existing body of knowledge.Thesis (PhD(Eng))--University of Pretoria, 2011.Electrical, Electronic and Computer Engineeringunrestricte

Ethics of the Sea – Experience of the Vis Archipelago Fishermen

Ethics of the Sea – Experience of the Vis Archipelago FishermenThis paper is based on the author's years-long research of the experience of fishermen of the island of Vis, their ethics and mutual relationships in the extreme conditions of fishing at distant open sea islands of the Adriatic where they were continously exposed to pirate attacks, open sea elements, with boats powered by wind or man, in small living quarters of a boat and fiercely competing with each other for survival. In such extreme conditions the only answer to the challenge of survival was mutual solidarity, willingness to help another, the principle of egalitarianism and mutual respect. The author also speaks about the transethnic culture of people living at sea, the phenomenon of the sea as the liquid element which does not divide but rather connects different shores, cultures and languages. He speaks about the insular world whose most important social principle is - work, manufacture as the basis of survival, sacrificing for another and high value of an individual  who  deserves to be held in esteem through his work and sacrifice as the corrective of selfish interests. Etyka morza – doświadczenie rybaków z wyspy VisArtykuł opiera się na wieloletnich badaniach autora nad doświadczeniem rybaków z wyspy Vis (Chorwacja), ich etyką i wzajemnymi relacjami w trudnych warunkach na odległych wyspach adriatyckich, gdzie nieustannie byli narażeni na ataki piratów, kaprysy otwartego morza; posługiwali się łodziami żaglowymi i wiosłowymi, żyjąc na małej przestrzeni i rywalizując między sobą o przetrwanie. W tak skrajnych warunkach jedynym wyjściem, by przetrwać, była wzajemna solidarność, troska o innego, zasada równości i wzajemny szacunek. Autor mówi też o transetnicznej kulturze ludów żyjących na morzu, zjawisku morza jako płynnego elementu, który nie dzieli, lecz raczej łączy różne brzegi, kultury i języki. Opisuje wyspiarski świat, gdzie najważniejszą zasadą społeczną jest praca, poświęcenie dla innego oraz wysoka wartość jednostki, która zasługuje na szacunek dzięki pracy i ofiarności, łagodzącym indywidualne interesy

Extremely Simple Activation Shaping for Out-of-Distribution Detection

The separation between training and deployment of machine learning models implies that not all scenarios encountered in deployment can be anticipated during training, and therefore relying solely on advancements in training has its limits. Out-of-distribution (OOD) detection is an important area that stress-tests a model's ability to handle unseen situations: Do models know when they don't know? Existing OOD detection methods either incur extra training steps, additional data or make nontrivial modifications to the trained network. In contrast, in this work, we propose an extremely simple, post-hoc, on-the-fly activation shaping method, ASH, where a large portion (e.g. 90%) of a sample's activation at a late layer is removed, and the rest (e.g. 10%) simplified or lightly adjusted. The shaping is applied at inference time, and does not require any statistics calculated from training data. Experiments show that such a simple treatment enhances in-distribution and out-of-distribution sample distinction so as to allow state-of-the-art OOD detection on ImageNet, and does not noticeably deteriorate the in-distribution accuracy. We release alongside the paper two calls for explanation and validation, believing the collective power to further validate and understand the discovery. Calls, video and code can be found at: https://andrijazz.github.io/ashComment: Preprint. 22 pages (14 main + appendix), 7 figure