CENH3-GFP: a visual marker for gametophytic and somatic ploidy determination in Arabidopsis thaliana

Background: The in vivo determination of the cell-specific chromosome number provides a valuable tool in several aspects of plant research. However, current techniques to determine the endosystemic ploidy level do not allow non-destructive, cell-specific chromosome quantification. Particularly in the gametophytic cell lineages, which are physically encapsulated in the reproductive organ structures, direct in vivo ploidy determination has been proven very challenging. Using Arabidopsis thaliana as a model, we here assess the applicability of recombinant CENH3-GFP reporters for the labeling of the cell’s chromocenters and for the monitoring of the gametophytic and somatic chromosome number in vivo. Results: By modulating expression of a CENH3-GFP reporter cassette using different promoters, we isolated two reporter lines that allow for a clear and highly specific labeling of centromeric chromosome regions in somatic and gametophytic cells respectively. Using polyploid plant series and reproductive mutants, we demonstrate that the pWOX2-CENH3-GFP recombinant fusion protein allows for the determination of the gametophytic chromosome number in both male and female gametophytic cells, and additionally labels centromeric regions in early embryo development. Somatic centromere labeling through p35S-CENH3-GFP shows a maximum of ten centromeric dots in young dividing tissues, reflecting the diploid chromosome number (2x = 10), and reveals a progressive decrease in GFP foci frequency throughout plant development. Moreover, using chemical and genetic induction of endomitosis, we demonstrate that CENH3-mediated chromosome labeling provides an easy and valuable tool for the detection and characterization of endomitotic polyploidization events. Conclusions: This study demonstrates that the introgression of the pWOX2-CENH3-GFP reporter construct in Arabidopsis thaliana provides an easy and reliable methodology for determining the chromosome number in developing male and female gametes, and during early embryo development. Somatically expressed CENH3-GFP reporters, on the other hand, constitute a valuable tool to quickly determine the basic somatic ploidy level in young seedlings at the individual cell level and to detect and to quantify endomitotic polyploidization events in a non-destructive, microscopy-based manner

Chromosome segregation in plant meiosis

Faithful chromosome segregation in meiosis is essential for ploidy stability over sexual life cycles. In plants, defective chromosome segregation caused by gene mutations or other factors leads to the formation of unbalanced or unreduced gametes creating aneuploid or polyploid progeny, respectively. Accurate segregation requires the coordinated execution of conserved processes occurring throughout the two meiotic cell divisions. Synapsis and recombination ensure the establishment of chiasmata that hold homologous chromosomes together allowing their correct segregation in the first meiotic division, which is also tightly regulated by cell-cycle dependent release of cohesin and monopolar attachment of sister kinetochores to microtubules. In meiosis II, bi-orientation of sister kinetochores and proper spindle orientation correctly segregate chromosomes in four haploid cells. Checkpoint mechanisms acting at kinetochores control the accuracy of kinetochore-microtubule attachment, thus ensuring the completion of segregation. Here we review the current knowledge on the processes taking place during chromosome segregation in plant meiosis, focusing on the characterization of the molecular factors involved

Comisíon Ortúzar: actions around the legacy of one/the refoundation

The text presents the Comisión Ortúzar: acciones en torno al legado de una/la refundación project, developed by Núcleo Arte, Política y Comunidad in the city of Santiago de Chile between 2014 and 2015. The focus of this paper is  to discuss a Latin American contemporary experience that stresses scene and history through interdisciplinary actions that seek to bring together artistic, political and community sectors.O texto apresenta o projeto Comisión Ortúzar: acciones en torno al legado de una/la refundación, desenvolvido pelo Núcleo Arte, Política y Comunidad na cidade de Santiago do Chile entre 2014 e 2015. O foco do artigo é debater uma experiência latino-americana contemporânea que tensiona cena e história através de ações interdisciplinares que buscam aproximar as searas artísticas, políticas e comunitárias

Your place or mine:Shared sensory experiences elicit a remapping of peripersonal space

Our perceptual systems integrate multisensory information about objects that are close to our bodies, which allow us to respond quickly and appropriately to potential threats, as well as act upon and manipulate useful tools. Intriguingly, the representation of this area close to our body, known as the multisensory 'peripersonal space' (PPS), can expand or contract during social interactions. However, it is not yet known how different social interactions can alter the representation of PPS. In particular, shared sensory experiences, such as those elicited by bodily illusions such as the enfacement illusion, can induce feelings of ownership over the other's body which has also been shown to increase the remapping of the other's sensory experiences onto our own bodies. The current study investigated whether such shared sensory experiences between two people induced by the enfacement illusion could alter the way PPS was represented, and whether this alteration could be best described as an expansion of one's own PPS towards the other or a remapping of the other's PPS onto one's own. An audio-tactile integration task allowed us to measure the extent of the PPS before and after a shared sensory experience with a confederate. Our results showed a clear increase in audio-tactile integration in the space close to the confederate's body after the shared experience. Importantly, this increase did not extend across the space between participant and confederate, as would be expected if the participant's PPS had expanded. Thus, the pattern of results is more consistent with a partial remapping of the confederate's PPS onto the participant's own PPS. These results have important consequences for our understanding of interpersonal space during different kinds of social interactions. (C) 2014 Elsevier Ltd. All rights reserved

Can you feel the body that you see? On the relationship between interoceptive accuracy and body image

Interoception and exteroception for body signals are two different ways of perceiving the self: the first from within, the second from outside. We investigated the relationship between Interoceptive Accuracy (IAcc) and external perception of the body and we tested if seeing the body from an external perspective can affect IAcc. Fifty-two healthy female subjects performed a standard heartbeat perception task to assess the IAcc, before and after the Body Image Revealer (BIR), which is a body perception task designed to assess the different aspects of body-image. The performance of the lower IAcc group in the heartbeat perception task significantly improved after the exteroceptive task. These findings highlight the relations between interoceptive and exteroceptive body-representations, supporting the view that these two kinds of awareness are linked and interact with each other

Entrevista com Ana Longoni

Entrevista realizada em 4 de abril de 2019, por Paola Zamariola.Entrevista realizada em 4 de abril de 2019, por Paola Zamariola.Entrevista realizada em 4 de abril de 2019, por Paola Zamariola

G-DfAM: a methodological proposal of generative design for additive manufacturing in the automotive industry

Metal additive manufacturing is an emerging technology in the industry and has a great potential. Moreover, new technologies like generative design can maximize this potential by computing complex optimized parts for additive manufacturing solutions. However, there is a lack of methodologies combining both recent and promising technologies. This paper first establishes a state of the art of design for additive manufacturing (DfAM) and generative design methodologies. Then it proposes a generic workflow for generative design tools and it proposes a challenge approach to develop a new DfAM method including generative design tools. Finally, a global 4-step methodology maximizing the potential of generative design and additive manufacturing, the G-DfAM method, is presented and validated through an automotive use case

Laboratórios abertos: Encontros artístico-pedagógicos com o grupo Yuyachkani

No presente artigo, pretendemos discutir algumas experiências artísticas e pedagógicas, realizadas pelo grupo peruano Yuyachkani em seus Laboratórios Abertos. Realizados há mais de uma década, é possível diagnosticar em suas proposições, uma constante investigação com relação à possibilidade de reativação da potência política da arte na atualidade. Tais laboratórios são compostos por espetáculos, demonstrações de trabalhos, mesas de debates, oficinas, treinamentos e experimentos cênicos realizados anualmente ao longo dos oito primeiros dias do mês de agosto. Neste intenso período, os/as artistas realizam férteis intercâmbios com criadores/as e investigadores/as, que se propõem a tal imersão, na sede do grupo, na cidade de Lima.

Technical assistance in the field of risk communication

This report assesses peer-reviewed and grey literature on risk communication concepts and practices, as requested by the European Commission to support the implementation of a ‘General Plan for Risk Communication’, i.e. an integrated framework for EU food safety risk assessors and risk managers at Union and national level, as required by the revised EU General Food Law Regulation. We conducted a scoping review of social research studies and official reports in relation to risk communication in the following areas: understanding and awareness of risk analysis roles and tasks, reducing misunderstanding of the different meaning of the terms ‘hazard’ and ‘risk’, tackling misinformation and disinformation, enhancing confidence in EU food safety, taking account of risk perceptions, key factors in trade-offs about risks, audience segmentation and tools, channels and mechanisms for coordinated risk communications. We structured our findings as follows: i) definitions of key concepts, ii) audience analysis and information requirements, iii) risk profiling, models and mechanisms, iv) contributions to communication strategies. We make several recommendations for consideration by the Commission, both in terms of actions to support the design and implementation of the general plan, and research needs that we consider crucial to further inform appropriate risk communication in the EU. EFSA carried out a targeted consultation of experts and a public consultation open to all interested parties including the general public, in preparing and finalising this report