32 research outputs found
Ecologies of dramaturgy in dance creation: a conversation
AW é Jamaicana, Preta, dançarina mulher cisgênero e dramaturga. Dois interesses paralelos emergiram gradualmente ao longo de sua carreira – a contribuição do performer ao processo criativo, e a dinâmica da operação necessariamente colaborativa que é a coreografia contemporânea. Esta entrevista com a artista-pesquisadora reporta sua experiência artística e o processo criativo da obra Confession Publique, ao qual ela ocupa a posição triádica de dramaturga, dançarina e pesquisadora auto-etnógrafa, compondo uma conversa dialógica entre artistas interdisciplinares e pesquisadores do projeto Dramaturgical Ecologies (sediado na Anonimo). Para além de uma entrevista, este projeto polivocal–centrado nos temas de agenciamento, dramaturgia, corporalização e movimento–migrou do físico para o virtual, respondendo a reconfiguração biopolítica causada pela pandemia do COVID-19. Esta transição ativou tensões e ressonâncias no diálogo que se tornaram limitações facilitadoras, onde os corpos envolvidos na pesquisa se tornaram parte da co-composição dramatúrgica do processo de escrita deste texto. O resultado está distribuído nas páginas que seguem, tomando forma de uma escrita performativa dialógica-reflexiva, criada a partir de um processo de pensamento coletivo. Angelique Willkie é Jamaicana, Preta, dançarina mulher cisgênero e dramaturga. Dois interesses paralelos emergiram gradualmente ao longo de sua carreira – a contribuição do performer ao processo criativo, e a dinâmica da operação necessariamente colaborativa que é a coreografia contemporânea. Esta entrevista com a artista-pesquisadora reporta sua experiência artística e o processo criativo da obra Confession Publique, ao qual ela ocupa a posição triádica de dramaturga, dançarina e pesquisadora auto-etnógrafa, compondo uma conversa dialógica entre artistas interdisciplinares e pesquisadores do projeto Dramaturgical Ecologies (sediado na Concordia University, CA). Para além de uma entrevista, este projeto polivocal–centrado nos temas de agenciamento, dramaturgia, corporalização e movimento–migrou do físico para o virtual, respondendo a reconfiguração biopolítica causada pela pandemia do COVID-19. Esta transição ativou tensões e ressonâncias no diálogo que se tornaram limitações facilitadoras, onde os corpos envolvidos na pesquisa se tornaram parte da co-composição dramatúrgica do processo de escrita deste texto. O resultado está distribuído nas páginas que seguem, tomando forma de uma escrita performativa dialógica-reflexiva, criada a partir de um processo de pensamento coletivo.
Acyclovir is activated into a HIV-1 reverse transcriptase inhibitor in herpesvirus-infected human tissues
For most viruses, there is a need for antimicrobials that target unique viral molecular properties. Acyclovir (ACV) is one such drug. It is activated into a human herpesvirus (HHV) DNA polymerase inhibitor exclusively by HHV kinases and, thus, does not suppress other viruses. Here, we show that ACV suppresses HIV-1 in HHV-coinfected human tissues, but not in HHV-free tissue or cell cultures. However, addition of HHV-6-infected cells renders these cultures sensitive to anti-HIV ACV activity. We hypothesized that such HIV suppression requires ACV phosphorylation by HHV kinases. Indeed, an ACV monophosphorylated prodrug bypasses the HHV requirement for HIV suppression. Furthermore, phosphorylated ACV directly inhibits HIV-1 reverse transcriptase (RT), terminating DNA chain elongation, and can trap RT at the termination site. These data suggest that ACV anti-HIV-1 activity may contribute to the response of HIV/HHV-coinfected patients to ACV treatment and could guide strategies for the development of new HIV-1 RT inhibitors
A phylogenetic framework of the legume genus Aeschynomene for comparative genetic analysis of the Nod-dependent and Nod-independent symbioses
Background : Among semi-aquatic species of the legume genus Aeschynomene, some have the property of being nodulated by photosynthetic Bradyrhizobium lacking the nodABC genes necessary for the synthesis of Nod factors. Knowledge of the specificities underlying this Nod-independent symbiosis has been gained from the model legume Aeschynomene evenia but our understanding remains limited due to the lack of comparative genetics with related taxa using a Nod factor-dependent process. To fill this gap, we combined different approaches to perform a thorough comparative analysis in the genus Aeschynomene. Results: This study significantly broadened previous taxon sampling, including in allied genera, in order to construct a comprehensive phylogeny. In the phylogenetic tree, five main lineages were delineated, including a novel lineage, the Nod-independent clade and another one containing a polytomy that comprised several Aeschynomene groups and all the allied genera. This phylogeny was matched with data on chromosome number, genome size and low-copy nuclear gene sequences to reveal the diploid species and a polytomy containing mostly polyploid taxa. For these taxa, a single allopolyploid origin was inferred and the putative parental lineages were identified. Finally, nodulation tests with different Bradyrhizobium strains revealed new nodulation behaviours and the diploid species outside of the Nod-independent clade were compared for their experimental tractability and genetic diversity. Conclusions: The extended knowledge of the genetics and biology of the different lineages sheds new light of the evolutionary history of the genus Aeschynomene and they provide a solid framework to exploit efficiently the diversity encountered in Aeschynomene legumes. Notably, our backbone tree contains all the species that are diploid and it clarifies the genetic relationships between the Nod-independent clade and the Nod-dependent lineages. This study enabled the identification of A. americana and A. patula as the most suitable species to undertake a comparative genetic study of the Nod-independent and Nod-dependent symbioses
Prognostic impact of vitamin B6 metabolism in lung cancer
Patients with non-small cell lung cancer (NSCLC) are routinely treated with cytotoxic agents such as cisplatin. Through a genome-wide siRNA-based screen, we identified vitamin B6 metabolism as a central regulator of cisplatin responses in vitro and in vivo. By aggravating a bioenergetic catastrophe that involves the depletion of intracellular glutathione, vitamin B6 exacerbates cisplatin-mediated DNA damage, thus sensitizing a large panel of cancer cell lines to apoptosis. Moreover, vitamin B6 sensitizes cancer cells to apoptosis induction by distinct types of physical and chemical stress, including multiple chemotherapeutics. This effect requires pyridoxal kinase (PDXK), the enzyme that generates the bioactive form of vitamin B6. In line with a general role of vitamin B6 in stress responses, low PDXK expression levels were found to be associated with poor disease outcome in two independent cohorts of patients with NSCLC. These results indicate that PDXK expression levels constitute a biomarker for risk stratification among patients with NSCLC.publishedVersio
Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network
Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects
Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo
Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level
Continuous monitoring of rhizosphere respiration after labelling of plant shoots with 14CO2
International audienceThe present work describes an original method to follow rate of (CO2)-C-14 and total CO2 production from rhizosphere respiration after plant shoots had been pulse-labelled with (CO2)-C-14. We used a radioactivity detector equipped with a plastic cell for flow detection of beta radiation by solid scintillation counting. The radioactivity detector was coupled with an infrared gas analyser. The flow detection of (CO2)-C-14 was compared to trapping of (CO2)-C-14 in NaOH and counting by liquid scintillation. First, we demonstrated that NaOH (1 M) trapped 95% of the CO2 of a gaseous sample. Then, we determined that the counting efficiency of the radioactivity flow cell was 41% of the activity of gaseous samples as determined by trapping in NaOH (1 M) and by counting by static liquid scintillation. The sensitivity of the (CO2)-C-14- flow detection was 0.08 Bq mL(-1) air and the precision was 2.9% of the activity measured compared to 0.9% for NaOH trapping method. We presented two applications which illustrate the relevance of (CO2)-C-14-flow detection to investigations using C-14 to trace photoassimilates within the plant-soil system. First, we examined the kinetics of (CO2)-C-14 production when concentrated acid is added to (NaHCO3)-C-14. This method is the most commonly used to label photoassimilates with C-14. Then, we monitored (CO2)-C-14 activity in rhizosphere respiration of 5-week old maize cultivated in soil and whose shoots had been pulse-labelled with (CO2)-C-14. We conclude that alkali traps should be used for a cumulative determination of (CO2)-C-14 because they are cheap and accurate. On the other hand, we demonstrated that the flow detection of (CO2)-C-14 had a finer temporal resolution and was consequently a relevant tool to study C dynamics in the rhizosphere at a short time scale
Processing of translational, radial and rotational optic flow in older adults
Abstract Aging impacts human observer’s performance in a wide range of visual tasks and notably in motion discrimination. Despite numerous studies, we still poorly understand how optic flow processing is impacted in healthy older adults. Here, we estimated motion coherence thresholds in two groups of younger (age: 18–30, n = 42) and older (70–90, n = 42) adult participants for the three components of optic flow (translational, radial and rotational patterns). Stimuli were dynamic random-dot kinematograms (RDKs) projected on a large screen. Participants had to report their perceived direction of motion (leftward versus rightward for translational, inward versus outward for radial and clockwise versus anti-clockwise for rotational patterns). Stimuli had an average speed of 7°/s (additional recordings were performed at 14°/s) and were either presented full-field or in peripheral vision. Statistical analyses showed that thresholds in older adults were similar to those measured in younger participants for translational patterns, thresholds for radial patterns were significantly increased in our slowest condition and thresholds for rotational patterns were significantly decreased. Altogether, these findings support the idea that aging does not lead to a general decline in visual perception but rather has specific effects on the processing of each optic flow component
Henri IV of France’s larynx 3D reconstitution
International audienceObjectives: King Henri IV of France (reign from 1589 to 1610) was one of the most important kings of France. Embalmed and buried in Saint-Denis, his remains were beheaded in 1793. His head (including his larynx) survived in successive private collections until its definitive identification in 2010. The purpose of the study was to provide a morphologic study of the larynx with a 3D reconstitution. Methods: A flexible endoscopy was performed via the mouth and via the trachea. Measures of the larynx (vocal folds lengths, thickness, width, larynx height) were collected from the CT-scan by a panel of experts blind each other. The segmentation of the laryngeal anatomical components (vocal folds, cartilages) was performed using 3DSlicer®. Mesh smoothing and 3D reconstitution were performed using Fusion 360®. Reconstitution was discussed between the experts. Decision was made by consensus after discussion. Results: Cricoid, thyroid, arytenoid cartilages, vocal folds and hyoid bone were identified and a computed 3D reconstitution of the larynx was made. The laryngeal 3D model appeared morphologically similar to a living subject. Measures were similar but smaller than those of a modern subject. Conclusions: The 3D reconstitution of the larynx of Henri IV of France was conducted from the CT-scan of his mummified head. This work constitutes a first valuable morphologic analysis of a larynx from an embalmed individual. This anatomical work is the first step towards the reconstruction of the voice of this historical character, which we hope to concretize with computer modeling tools in a second step. Level of evidence: V based on experiential and non-research evidence
ER stress inhibits neuronal death by promoting autophagy
Endoplasmic reticulum (ER) stress has been implicated in neurodegenerative diseases but its relationship and role in disease progression remain unclear. Using genetic and pharmacological approaches, we showed that mild ER stress ("preconditioning") is neuroprotective in Drosophila and mouse models of Parkinson disease. In addition, we found that the combination of mild ER stress and apoptotic signals triggers an autophagic response both in vivo and in vitro. We showed that when autophagy is impaired, ER-mediated protection is lost. We further demonstrated that autophagy inhibits caspase activation and apoptosis. Based on our findings, we conclude that autophagy is required for the neuroprotection mediated by mild ER stress, and therefore ER preconditioning has potential therapeutic value for the treatment of neurodegenerative diseases