Adaptive clustering procedure for continuous gravitational wave searches

In hierarchical searches for continuous gravitational waves, clustering of candidates is an important postprocessing step because it reduces the number of noise candidates that are followed-up at successive stages [1][7][12]. Previous clustering procedures bundled together nearby candidates ascribing them to the same root cause (be it a signal or a disturbance), based on a predefined cluster volume. In this paper, we present a procedure that adapts the cluster volume to the data itself and checks for consistency of such volume with what is expected from a signal. This significantly improves the noise rejection capabilities at fixed detection threshold, and at fixed computing resources for the follow-up stages, this results in an overall more sensitive search. This new procedure was employed in the first Einstein@Home search on data from the first science run of the advanced LIGO detectors (O1) [11].Comment: 11 pages, 9 figures, 2 tables; v1: initial submission; v2: journal review, copyedited version; v3: fixed typo in Fig

I-V Curve Tracer Communication Protocol

This thesis aims at developing a communication protocol for an I-V Curve Tracer. The IV Curve Tracer consists of a Raspberry Pi as the central unit to which a Source Measuring Unit (SMU) and a Relay Board is connected via USB and Ethernet, respectively. The SMU measures the I-V curve by generating a voltage sweep and measuring the resulting current. The relay board enables testing of multiple specimens. We include an Arduino Mega in this set up to accelerate the communication interface between the Relay modules and the Raspberry Pi. Therefore, our project aims to address the challenge of a scalable, low latency communication between the Pi-Arduino-Relay interface. Each Arduino is connected to one or multiple relay modules that are used to configure the interconnection between a single measurement device and various combinations of multiple PV cells in a current-voltage curve tracer (IVCT) testbed. This is significant because the time taken to complete a battery of tests using previous methods is over 15 minutes. However, an initial timing analysis found that the majority of the testing interval was spent on the communication to setup the relay configuration, not on the actual measurement process and hence, caused the relay boards to be slow to respond. This significantly limited the ability of the IVCT to scale-up in number of DUTs and complexity of interconnections tested. Our project seeks to overcome limitations of the current technology by significantly reducing the packet size of the transmitted data and eliminating the bloated and slow IoT platform. The expected outcome is a lightweight communication platform that is flexible and scalable with fast messaging not just for the IVCT testbed but also suitable for other research laboratory automation and control

A short antisense oligonucleotide masking a unique intronic motif prevents skipping of a critical exon in spinal muscular atrophy

Spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality. Most SMA cases are associated with the low levels of SMN owing to deletion of Survival Motor Neuron 1 (SMN1). SMN2, a nearly identical copy of SMN1, fails to compensate for the loss of SMN1 due to predominant skipping of exon 7. Hence, correction of aberrant splicing of SMN2 exon 7 holds the potential for cure of SMA. Here we report an 8-mer antisense oligonucleotide (ASO) to have a profound stimulatory response on correction of aberrant splicing of SMN2 exon 7 by binding to a unique GC-rich sequence located within intron 7 of SMN2. We confirm that the splicing-switching ability of this short ASO comes with a high degree of specificity and reduced off-target effect compared to larger ASOs targeting the same sequence. We further demonstrate that a single low nanomolar dose of this 8-mer ASO substantially increases the levels of SMN and a host of factors including Gemin 2, Gemin 8, ZPR1, hnRNP Q and Tra2-β1 known to be down regulated in SMA. Our findings underscore the advantages and unmatched potential of very short ASOs in splicing modulation in vivo

Lipophagy: Connecting Autophagy and Lipid Metabolism

Lipid droplets (LDs), initially considered “inert” lipid deposits, have gained during the last decade the classification of cytosolic organelles due to their defined composition and the multiplicity of specific cellular functions in which they are involved. The classification of LD as organelles brings along the need for their regulated turnover and recent findings support the direct contribution of autophagy to this turnover through a process now described as lipophagy. This paper focuses on the characteristics of this new type of selective autophagy and the cellular consequences of the mobilization of intracellular lipids through this process. Lipophagy impacts the cellular energetic balance directly, through lipid breakdown and, indirectly, by regulating food intake. Defective lipophagy has been already linked to important metabolic disorders such as fatty liver, obesity and atherosclerosis, and the age-dependent decrease in autophagy could underline the basis for the metabolic syndrome of aging

Models and Materials for Generalized Kitaev Magnetism

The exactly solvable Kitaev model on the honeycomb lattice has recently received enormous attention linked to the hope of achieving novel spin-liquid states with fractionalized Majorana-like excitations. In this review, we analyze the mechanism proposed by G. Jackeli and G. Khaliullin to identify Kitaev materials based on spin-orbital dependent bond interactions and provide a comprehensive overview of its implications in real materials. We set the focus on experimental results and current theoretical understanding of planar honeycomb systems (Na$_2$IrO$_3$, $\alpha$-Li$_2$IrO$_3$, and $\alpha$-RuCl$_3$), three-dimensional Kitaev materials ($\beta$- and $\gamma$-Li$_2$IrO$_3$), and other potential candidates, completing the review with the list of open questions awaiting new insights.Comment: updated references, published versio