43 research outputs found
Red light represses the photophysiology of the scleractinian coral Stylophora pistillata
Light spectrum plays a key role in the biology of symbiotic corals, with blue light resulting in higher coral growth, zooxanthellae density, chlorophyll a content and photosynthesis rates as compared to red light. However, it is still unclear whether these physiological processes are blue-enhanced or red-repressed. This study investigated the individual and combined effects of blue and red light on the health, zooxanthellae density, photophysiology and colouration of the scleractinian coral Stylophora pistillata over 6 weeks. Coral fragments were exposed to blue, red, and combined 50/50% blue red light, at two irradiance levels (128 and 256 μmol m−2 s−1). Light spectrum affected the health/survival, zooxanthellae density, and NDVI (a proxy for chlorophyll a content) of S. pistillata. Blue light resulted in highest survival rates, whereas red light resulted in low survival at 256 μmol m−2 s−1. Blue light also resulted in higher zooxanthellae densities compared to red light at 256 μmol m−2 s−1, and a higher NDVI compared to red and combined blue red light. Overall, our results suggest that red light negatively affects the health, survival, symbiont density and NDVI of S. pistillata, with a dominance of red over blue light for NDVI
Development of an amplicon-based sequencing approach in response to the global emergence of mpox
The 2022 multicountry mpox outbreak concurrent with the ongoing Coronavirus Disease 2019 (COVID-19) pandemic further highlighted the need for genomic surveillance and rapid pathogen whole-genome sequencing. While metagenomic sequencing approaches have been used to sequence many of the early mpox infections, these methods are resource intensive and require samples with high viral DNA concentrations. Given the atypical clinical presentation of cases associated with the outbreak and uncertainty regarding viral load across both the course of infection and anatomical body sites, there was an urgent need for a more sensitive and broadly applicable sequencing approach. Highly multiplexed amplicon-based sequencing (PrimalSeq) was initially developed for sequencing of Zika virus, and later adapted as the main sequencing approach for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Here, we used PrimalScheme to develop a primer scheme for human monkeypox virus that can be used with many sequencing and bioinformatics pipelines implemented in public health laboratories during the COVID-19 pandemic. We sequenced clinical specimens that tested presumptively positive for human monkeypox virus with amplicon-based and metagenomic sequencing approaches. We found notably higher genome coverage across the virus genome, with minimal amplicon drop-outs, in using the amplicon-based sequencing approach, particularly in higher PCR cycle threshold (Ct) (lower DNA titer) samples. Further testing demonstrated that Ct value correlated with the number of sequencing reads and influenced the percent genome coverage. To maximize genome coverage when resources are limited, we recommend selecting samples with a PCR Ct below 31 Ct and generating 1 million sequencing reads per sample. To support national and international public health genomic surveillance efforts, we sent out primer pool aliquots to 10 laboratories across the United States, United Kingdom, Brazil, and Portugal. These public health laboratories successfully implemented the human monkeypox virus primer scheme in various amplicon sequencing workflows and with different sample types across a range of Ct values. Thus, we show that amplicon-based sequencing can provide a rapidly deployable, cost-effective, and flexible approach to pathogen whole-genome sequencing in response to newly emerging pathogens. Importantly, through the implementation of our primer scheme into existing SARS-CoV-2 workflows and across a range of sample types and sequencing platforms, we further demonstrate the potential of this approach for rapid outbreak response.This publication was made possible by
CTSA Grant Number UL1 TR001863 from the
National Center for Advancing Translational
Science (NCATS), a component of the National
Institutes of Health (NIH) awarded to CBFV. INSA
was partially funded by the HERA project (Grant/
2021/PHF/23776) supported by the European
Commission through the European Centre for
Disease Control (to VB).info:eu-repo/semantics/publishedVersio
Can fetal ultrasound result in prenatal diagnosis of Prader-Willi syndrome?
OBJECTIVE: To define fetal ultrasound characteristics triggering an antenatal diagnosis of Prader Willi syndrome (PWS).
METHODS: Retrospective analysis of sonographic characteristics retrieved from obstetric ultrasound records. All children (n=11) had a postnatal genetically confirmed diagnosis of PWS.
RESULTS: All patients (n=11) showed at least one aspecific abnormality on prenatal ultrasound. Ten out of eleven (90.9 %) had decreased fetal movements, 7 (63.6%) presented in breech position, 7 (63.6%) had severe intra-uterine growth restriction (<5th centile) and 4 (36.4%) showed a polyhydramnios. Immobile flexed limbs and clenched hands were seen in one patient (9.1%). Severe growth restriction combined with polyhydramnios favors the diagnosis in 3/11 cases.
CONCLUSION: Prenatal sonographic phenotype of PWS includes decreased fetal movements, fetal malpresentation, severe intra-uterine growth restriction and polyhydramnios. These findings are not specific to PWS, but the combination of some of them (especially severe intra-uterine growth restriction and polyhydramnios) can prompt clinicians to perform invasive testing leading to a molecular cytogenomic diagnosis prenatally.status: publishe
Discrimination of locomotion direction in impoverished displays of walkers by macaque monkeys
A vast literature exists on human biological motion perception in impoverished displays, e.g., point-light walkers. Less is known about the perception of impoverished biological motion displays in macaques. We trained 3 macaques in the discrimination of facing direction (left versus right) and forward versus backward walking using motion-capture-based locomotion displays (treadmill walking) in which the body features were represented by cylinder-like primitives. The displays did not contain translatory motion. Discriminating forward versus backward locomotion requires motion information while the facing-direction/view task can be solved using motion and/or form. All monkeys required lengthy training to learn the forward-backward task, while the view task was learned more quickly. Once acquired, the discriminations were specific to walking and stimulus format but generalized across actors. Although the view task could be solved using form cues, there was a small impact of motion. Performance in the forward-backward task was highly susceptible to degradations of spatiotemporal stimulus coherence and motion information. These results indicate that rhesus monkeys require extensive training in order to use the intrinsic motion cues related to forward versus backward locomotion and imply that extrapolation of observations concerning human perception of impoverished biological motion displays onto monkey perception needs to be made cautiously
Discrimination of locomotion direction at different speeds: A comparison between macaque monkeys and algorithms
Nater F., Vangeneugden J., Grabner H., Van Gool L., Vogels R., ''Discrimination of locomotion direction at different speeds: A comparison between macaque monkeys and algorithms'', Detection and identification of rare audiovisual cues (series : studies in computational intelligence), vol. 384, pp. 181-190, Weinshall Daphna, Anemüller Jörn and Van Gool Luc, eds., 2012, Springer-Verlag Berlin Heidelberg.status: publishe
Mission du Team belge au Kosovo :science et justice à la rencontre du drame humain. Premiers résultats
info:eu-repo/semantics/publishe
Mission du team belge au Kosovo: science et justice à la rencontre du drame humain. Premiers résultats
peer reviewe
Distinct Mechanisms for Coding of Visual Actions in Macaque Temporal Cortex
Temporal cortical neurons are known to respond to visual dynamic-action displays. Many human psychophysical and functional imaging studies examining biological motion perception have used treadmill walking, in contrast to previous macaque single-cell studies. We assessed the coding of locomotion in rhesus monkey (Macaca mulatta) temporal cortex using movies of stationary walkers, varying both form and motion (i.e., different facing directions) or varying only the frame sequence (i.e., forward vs backward walking). The majority of superior temporal sulcus and inferior temporal neurons were selective for facing direction, whereas a minority distinguished forward from backward walking. Support vector machines using the temporal cortical population responses as input classified facing direction well, but forward and backward walking less so. Classification performance for the latter improved markedly when the within-action response modulation was considered, reflecting differences in momentary body poses within the locomotion sequences. Responses to static pose presentations predicted the responses during the course of the action. Analyses of the responses to walking sequences wherein the start frame was varied across trials showed that some neurons also carried a snapshot sequence signal. Such sequence information was present in neurons that responded to static snapshot presentations and in neurons that required motion. Our data suggest that actions are analyzed by temporal cortical neurons using distinct mechanisms. Most neurons predominantly signal momentary pose. In addition, temporal cortical neurons, including those responding to static pose, are sensitive to pose sequence, which can contribute to the signaling of learned action sequences.Vangeneugden J., De Mazière P.A., Van Hulle M.M., Jaeggli T., Van Gool L., Vogels R., ''Distinct mechanisms for coding of visual actions in macaque temporal cortex'', Journal of neuroscience, vol. 31, no. 2, pp. 385-401, January 2011.status: publishe
DIRAC: Detection and Identification of Rare Audio-Visual Events
The DIRAC project was an integrated project that was carried out between January 1 st 2006 and December 31 st 2010. It was funded by the European Commission within the Sixth Framework Research Programme (FP6) under contract number IST-027787. Ten partners joined forces to investigate the concept of rare events in machine and cognitive systems, and developed multi-modal technology to identify such events and deal with them in audio-visual applications. This document summarizes the project and its achievements. In Section 2 we present the research and engineering problem that the project set out to tackle, and discuss why we believe that advance made on solving these problems will get us closer to achieving the general objective of building artificial cognitive system with cognitive capabilities. We describe the approach taken to solving the problem, detailing the theoretical framework we came up with. We further describe how the inter-disciplinary nature of our research and evidence collected from biological and cognitive systems gave us the necessary insights and support for the proposed approach. In Section 3 we describe our efforts towards system design that follow the principles identified in our theoretical investigation. In Section 4 we describe a variety of algorithms we have developed in the context of different applications, to implement the theoretical framework described in Section 2. In Section 5 we describe algorithmic progress on a variety of questions that concern the learning of those rare events as defined in our Section 2. Finally, in Section 6 we describe our application scenarios, an integrated test-bed developed to test our algorithms in an integrated way. © 2012 Springer-Verlag Berlin Heidelberg.Anemüller J., Caputo B., Hermansky H., Ohl F.W., Pajdla T., Pavel M., Van Gool L., Vogels R., Wabnik S., Weinshall D., ''DIRAC: Detection and Identification of Rare Audio-Visual Events'', Detection and identification of rare audiovisual cues (series : studies in computational intelligence), vol. 384, pp. 3-35, Weinshall Daphna, Anemüller Jörn and Van Gool Luc, eds., 2012, Springer-Verlag Berlin Heidelberg.status: publishe
Zooxanthellae density under various experimental conditions (blue, red, 50/50% blue red and white light at an irradiance of 128/256 μmol m<sup>−2</sup> s<sup>−1</sup>) after week 6.
<p>Values are means + s.d. (<i>N</i> = 4). **Indicates significant difference (<i>P</i><0.010).</p