Supramolecular Fullerene Materials

With its unique physical and chemical properties, buckminsterfullerene C60 is becoming an attractive functional component for incorporation into three-dimensional molecular assemblies and supramolecular arrays with potential applications as advanced materials. In this article, we discuss the self-organization of C60 derivatives into ordered fullerene thin films using Langmuir techniques. Subsequently, it is shown how metal ion complexation at a crown ether site in tight proximity to the fullerene surface perturbs the electronic structure of the carbon sphere. Covalently modified fullerenes are used for the construction of interlocked molecules, such as rotaxanes and catenanes, with fascinating topologies. Finally, the formation of a C60-containing tetracationic cyclophane by PtII-directed self-assembly of two di(pyridyl)methanofullerene moieties is presented. These recent advances have become possible only through the development of a new synthetic methodology, which provides controlled, regioselective access to multiply functionalized fullerene derivatives

Venus wind map at cloud top level with the MTR/THEMIS visible spectrometer. I. Instrumental performance and first results

Solar light gets scattered at cloud top level in Venus' atmosphere, in the visible range, which corresponds to the altitude of 67 km. We present Doppler velocity measurements performed with the high resolution spectrometer MTR of the Solar telescope THEMIS (Teide Observatory, Canary Island) on the sodium D2 solar line (5890 \AA). Observations lasted only 49 min because of cloudy weather. However, we could assess the instrumental velocity sensitivity, 31 m/s per pixel of 1 arcsec, and give a value of the amplitude of zonal wind at equator at 151 +/- 16 m/s.Comment: 17 pages, 12 figure

A natural stochastic extension of the sandpile model on a graph

We introduce a new model of a stochastic sandpile on a graph $G$ containing a sink. When unstable, a site sends one grain to each of its neighbours independently with probability $p \in (0,1]$. For $p=1$, this coincides with the standard Abelian sandpile model. In general, for $p\in(0,1)$, the set of recurrent configurations of this sandpile model is different from that of the Abelian sandpile model. We give a characterisation of this set in terms of orientations of the graph $G$. We also define the lacking polynomial $L_G$ as the generating function counting this set according to the number of grains, and show that this polynomial satisfies a recurrence which resembles that of the Tutte polynomial

Parallel optimization of fiber bundle segmentation for massive tractography datasets

We present an optimized algorithm that performs automatic classification of white matter fibers based on a multi-subject bundle atlas. We implemented a parallel algorithm that improves upon its previous version in both execution time and memory usage. Our new version uses the local memory of each processor, which leads to a reduction in execution time. Hence, it allows the analysis of bigger subject and/or atlas datasets. As a result, the segmentation of a subject of 4,145,000 fibers is reduced from about 14 minutes in the previous version to about 6 minutes, yielding an acceleration of 2.34. In addition, the new algorithm reduces the memory consumption of the previous version by a factor of 0.79.Comment: This research has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sk{\l}odowska-Curie Actions H2020-MSCA-RISE-2015 BIRDS GA No. 690941, CONICYT PFCHA/ DOCTORADO NACIONAL/2016-21160342, CONICYT FONDECYT 1161427, CONICYT PIA/Anillo de Investigaci\'on en Ciencia y Tecnolog\'ia ACT172121, CONICYT BASAL FB0008 and from CONICYT Basal FB000

Stimuli‐Responsive Resorcin[4]arene Cavitands: Toward Visible‐Light‐Activated Molecular Grippers

Resorcin[4]arene cavitands, equipped with diverse quinone (Q) and [Ru(bpy)(2)dppz](2+)(bpy=2,2 '-bipyridine, dppz=dipyrido[3,2-a:2 ',3 '-c]phenazine) photosensitizing walls in different configurations, were synthesized. Upon visible-light irradiation at 420 nm, electron transfer from the [Ru(bpy)(2)dppz](2+)to theQgenerates the semiquinone (SQ) radical anion, triggering a large conformational switching from a flatkiteto avasewith a cavity for the encapsulation of small guests, such as cyclohexane and heteroalicyclic derivatives, in CD3CN. Depending on the molecular design, theSQradical anion can live for several minutes (approximate to 10 min) and thevasecan be generated in a secondary process without need for addition of a sacrificial electron donor to accumulate theSQstate. Switching can also be triggered by other stimuli, such as changes in solvent, host-guest complexation, and chemical and electrochemical processes. This comprehensive investigation benefits the development of stimuli-responsive nanodevices, such as light-activated molecular grippers

REPORT OF THE 2021 ICCAT SWORDFISH BIOLOGY WORKSHOP (Online, 22-26 March 2021)

“The results, conclusions and recommendations contained in this Report only reflect what was discussed by the Group of scientists that participated in the 2021 Swordfish Biology Workshop. Therefore, these should be considered preliminary until the Swordfish Species Group and the SCRS discuss and possibly adopts them at its annual Plenary meeting and the Commission revise them at its Annual meeting. Accordingly, ICCAT reserves the right to comment, object and endorse this Report, until it is finally adopted by the Commission.”En prens