Brown representability for space-valued functors

In this paper we prove two theorems which resemble the classical cohomological and homological Brown representability theorems. The main difference is that our results classify small contravariant functors from spaces to spaces up to weak equivalence of functors. In more detail, we show that every small contravariant functor from spaces to spaces which takes coproducts to products up to homotopy and takes homotopy pushouts to homotopy pullbacks is naturally weekly equivalent to a representable functor. The second representability theorem states: every contravariant continuous functor from the category of finite simplicial sets to simplicial sets taking homotopy pushouts to homotopy pullbacks is equivalent to the restriction of a representable functor. This theorem may be considered as a contravariant analog of Goodwillie's classification of linear functors.Comment: 19 pages, final version, accepted by the Israel Journal of Mathematic

Hemodynamics in the thoracic aorta using OpenFOAM: 4D PCMRI versus CFD

The aim of this work is the study of fluid dynamics models using the CFD software OpenFOAM, an open source software allowing meshing, manipulation, simulation and post-processing of many problems involving fluid mechanics. The work consists of a study with OpenFOAM of a real engineering problem, namely to analyze hemodynamics in the thoracic aorta in collaboration with CIMNE (Centre Internacional de Metodes Numerics a l'Enginyeria) and LABSON-UPC (Laboratorio de Sistemas Oleohidricos y Neumcos). Speci cally, the study aims to compute the shear stress that blood causes to aorta walls

Transcriptional analysis of the HeT-A retrotransposon in mutant and wild type stocks reveals high sequence variability at Drosophila telomeres and other unusual features

<p>Abstract</p> <p>Background</p> <p>Telomere replication in Drosophila depends on the transposition of a domesticated retroelement, the <it>HeT-A </it>retrotransposon. The sequence of the <it>HeT-A </it>retrotransposon changes rapidly resulting in differentiated subfamilies. This pattern of sequence change contrasts with the essential function with which the <it>HeT-A </it>is entrusted and brings about questions concerning the extent of sequence variability, the telomere contribution of different subfamilies, and whether wild type and mutant Drosophila stocks show different <it>HeT-A </it>scenarios.</p> <p>Results</p> <p>A detailed study on the variability of <it>HeT-A </it>reveals that both the level of variability and the number of subfamilies are higher than previously reported. Comparisons between GIII, a strain with longer telomeres, and its parental strain Oregon-R indicate that both strains have the same set of <it>HeT-A </it>subfamilies. Finally, the presence of a highly conserved splicing pattern only in its antisense transcripts indicates a putative regulatory, functional or structural role for the <it>HeT-A </it>RNA. Interestingly, our results also suggest that most <it>HeT-A </it>copies are actively expressed regardless of which telomere and where in the telomere they are located.</p> <p>Conclusions</p> <p>Our study demonstrates how the <it>HeT-A </it>sequence changes much faster than previously reported resulting in at least nine different subfamilies most of which could actively contribute to telomere extension in Drosophila. Interestingly, the only significant difference observed between Oregon-R and GIII resides in the nature and proportion of the antisense transcripts, suggesting a possible mechanism that would in part explain the longer telomeres of the GIII stock.</p

Transposable element polymorphisms improve prediction of complex agronomic traits in rice

Acord transformatiu CRUE-CSICKey message: Transposon insertion polymorphisms can improve prediction of complex agronomic traits in rice compared to using SNPs only, especially when accessions to be predicted are less related to the training set. Abstract: Transposon insertion polymorphisms (TIPs) are significant sources of genetic variation. Previous work has shown that TIPs can improve detection of causative loci on agronomic traits in rice. Here, we quantify the fraction of variance explained by single nucleotide polymorphisms (SNPs) compared to TIPs, and we explore whether TIPs can improve prediction of traits when compared to using only SNPs. We used eleven traits of agronomic relevance from by five different rice population groups (Aus, Indica, Aromatic, Japonica, and Admixed), 738 accessions in total. We assess prediction by applying data split validation in two scenarios. In the within-population scenario, we predicted performance of improved Indica varieties using the rest of Indica accessions. In the across population scenario, we predicted all Aromatic and Admixed accessions using the rest of populations. In each scenario, Bayes C and a Bayesian reproducible kernel Hilbert space regression were compared. We find that TIPs can explain an important fraction of total genetic variance and that they also improve genomic prediction. In the across population prediction scenario, TIPs outperformed SNPs in nine out of the eleven traits analyzed. In some traits like leaf senescence or grain width, using TIPs increased predictive correlation by 30-50%. Our results evidence, for the first time, that TIPs genotyping can improve prediction on complex agronomic traits in rice, especially when accessions to be predicted are less related to training accessions

Forecasting in the light of Big Data

Predicting the future state of a system has always been a natural motivation for science and practical applications. Such a topic, beyond its obvious technical and societal relevance, is also interesting from a conceptual point of view. This owes to the fact that forecasting lends itself to two equally radical, yet opposite methodologies. A reductionist one, based on the first principles, and the naive inductivist one, based only on data. This latter view has recently gained some attention in response to the availability of unprecedented amounts of data and increasingly sophisticated algorithmic analytic techniques. The purpose of this note is to assess critically the role of big data in reshaping the key aspects of forecasting and in particular the claim that bigger data leads to better predictions. Drawing on the representative example of weather forecasts we argue that this is not generally the case. We conclude by suggesting that a clever and context-dependent compromise between modelling and quantitative analysis stands out as the best forecasting strategy, as anticipated nearly a century ago by Richardson and von Neumann

A Heuristic Based on the Intrinsic Dimensionality for Reducing the Number of Cyclic DTW Comparisons in Shape Classification and Retrieval Using AESA

Cyclic Dynamic Time Warping (CDTW) is a good dissimilarity of shape descriptors of high dimensionality based on contours, but it is computationally expensive. For this reason, to perform recognition tasks, a method to reduce the number of comparisons and avoid an exhaustive search is convenient. The Approximate and Eliminate Search Algorithm (AESA) is a relevant indexing method because of its drastic reduction of comparisons, however, this algorithm requires a metric distance and that is not the case of CDTW. In this paper, we introduce a heuristic based on the intrinsic dimensionality that allows to use CDTW and AESA together in classification and retrieval tasks over these shape descriptors. Experimental results show that, for descriptors of high dimensionality, our proposal is optimal in practice and significantly outperforms an exhaustive search, which is the only alternative for them and CDTW in these tasks

MISMIS: Desinformación y agresividad en los medios de comunicación social: agregando información y analizando el lenguaje

[EN] The general objectives of the project are to address and monitor misinformation (biased and fake news) and miscommunication (aggressive language and hate speech) in social media, as well as to establish a high quality methodological standard for the whole research community (i) by developing rich annotated datasets, a data repository and online evaluation services; (ii) by proposing suitable evaluation metrics; and (iii) by organizing evaluation campaigns to foster research on the above issues.[ES] Los objetivos generales del proyecto son abordar y monitorizar la desinformación (noticias sesgadas y falsas) y la mala comunicación (lenguaje agresivo y mensajes de odio) en los medios de comunicación social, así como establecer un estándar metodológico de calidad para toda la comunidad investigadora mediante: i) el desarrollo de datasets anotados, un repositorio de datos y servicios de evaluación online; ii) la propuesta de métricas de evaluación adecuadas; y iii) la organización de campañas de evaluación para fomentar la investigación sobre las cuestiones mencionadas.The MISMIS project (PGC2018-096212-B) is funded by the Spanish Ministry of Science, Innovation and Universities.Rosso, P.; Casacuberta Nolla, F.; Gonzalo, J.; Plaza, L.; Carrillo, J.; Amigó, E.; Verdejo, MF.... (2020). MISMIS: Misinformation and Miscommunication in social media: aggregating information and analysing language. Procesamiento del Lenguaje Natural. (65):101-104. https://doi.org/10.26342/2020-65-13S1011046

Influence of overlapping décollements, syn-tectonic sedimentation and structural inheritace in the evolution of contractional system: The central Kuqa fold-and-thrust bely (Tian Shan Mountains, NW China)

Contractional deformation in the Kuqa fold‐and‐thrust belt (southern foreland of the Tian Shan Mountains, NW China) is recorded by well‐preserved syntectonic continental sequences. In addition, its structural evolution was strongly controlled by synorogenic salt (Eocene in age) and presalt décollements with varying spatial distribution. We present a balanced and sequentially restored cross section across the central part of this fold‐and‐thrust belt that provides a new interpretation of the structure beneath the evaporites, in which Paleozoic and Mesozoic strata are deformed by a thrust stack involving (i) a thin‐skinned thrust system detached on Triassic‐Jurassic coal units and (ii) an ensemble of south‐directed basement thrusts. The latter formed from the inversion of Mesozoic extensional faults such as those preserved both in the Tarim foreland basin and beneath the frontal part of the Kuqa fold‐and‐thrust belt. The constructed section shows a total shortening of 35 km from the Late Cretaceous to the present. The restoration depicts a three‐stage evolution for the Kuqa fold‐and‐thrust belt: (i) minor Mesozoic extension, (ii) an early compressional stage (Late Cretaceous to early Miocene) with low shortening and syntectonic sedimentary rates, and (iii) a later compressional stage (late Pliocene‐Pleistocene) characterized by a greater and progressively increasing shortening rate and rapid deposition. Our results are discussed in light of previous analogue and numerical modeling studies and demonstrate the control exerted by the interplay between syntectonic sedimentation, the inversion of inherited basement structures, and the nature and extent of Triassic/Jurassic and Eocene décollements

Marine radioecology after the Fukushima Dai-ichi nuclear accident : are we better positioned to understand the impact of radionuclides in marine ecosystems?

© The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Science of The Total Environment 618 (2017): 80-92, doi:10.1016/j.scitotenv.2017.11.005.This paper focuses on how a community of researchers under the COMET (CO-ordination and iMplementation of a pan European projecT for radioecology) project has improved the capacity of marine radioecology to understand at the process level the behaviour of radionuclides in the marine environment, uptake by organisms and the resulting doses after the Fukushima Dai-ichi nuclear accident occurred in 2011. We present new radioecological understanding of the processes involved, such as the interaction of waterborne radionuclides with suspended particles and sediments or the biological uptake and turnover of radionuclides, which have been better quantified and mathematically described. We demonstrate that biokinetic models can better represent radionuclide transfer to biota in non-equilibrium situations, bringing more realism to predictions, especially when combining physical, chemical and biological interactions that occur in such an open and dynamic environment as the ocean. As a result, we are readier now than we were before the FDNPP accident in terms of having models that can be applied to dynamic situations. The paper concludes with our vision for marine radioecology as a fundamental research discipline and we present a strategy for our discipline at the European and international levels. The lessons learned are presented along with their possible applicability to assess/reduce the environmental consequences of future accidents to the marine environment and guidance for future research, as well as to assure sustainability of marine radioecology in Europe and globally. This guidance necessarily reflects on why and where further research funding is needed, signalling the way for future investigations.The research leading to this paper has received funding from the European Union's seventh Framework programme (FP7/2007-2013) under grant agreement No. is 604974 (Projects within COMET: Marine Initial Research Activity and The impact of recent releases from the Fukushima nucleaR Accident on the Marine Environment - FRAME). Sampling off Japan has been supported by the Gordon and Betty Moore Foundation, the Deerbrook Charitable Trust and contributions to the WHOI Centre for Marine and Environmental Radioactivity. We acknowledge the JSPS KAKENHI Grant-in-Aid for Scientific Research on Innovative Areas Grant No. 24110005 for supporting in part the activities during the research cruises to the FDNPP area

GBA mutation promotes early mitochondrial dysfunction in 3D neurosphere models

Glucocerebrosidase (GBA) mutations are the most important genetic risk factor for the development of Parkinson disease (PD). GBA encodes the lysosomal enzyme glucocerebrosidase (GCase). Loss-of-GCase activity in cellular models has implicated lysosomal and mitochondrial dysfunction in PD disease pathogenesis, although the exact mechanisms remain unclear. We hypothesize that GBA mutations impair mitochondria quality control in a neurosphere model.We have characterized mitochondrial content, mitochondrial function and macroautophagy flux in 3D-neurosphere-model derived from neural crest stem cells containing heterozygous and homozygous N370SGBA mutations, under carbonyl cyanide-m-chlorophenyl-hydrazine (CCCP)- induced mitophagy.Our findings on mitochondrial markers and ATP levels indicate that mitochondrial accumulation occurs in mutant N370SGBA neurospheres under basal conditions, and clearance of depolarised mitochondria is impaired following CCCP-treatment. A significant increase in TFEB-mRNA levels, the master regulator of lysosomal and autophagy genes, may explain an unchanged macroautophagy flux in N370SGBA neurospheres. PGC1α-mRNA levels were also significantly increased following CCCP-treatment in heterozygote, but not homozygote neurospheres, and might contribute to the increased mitochondrial content seen in cells with this genotype, probably as a compensatory mechanism that is absent in homozygous lines.Mitochondrial impairment occurs early in the development of GCase-deficient neurons. Furthermore, impaired turnover of depolarised mitochondria is associated with early mitochondrial dysfunction.In summary, the presence of GBA mutation may be associated with higher levels of mitochondrial content in homozygous lines and lower clearance of damaged mitochondria in our neurosphere model