56 research outputs found
Murine Dishevelled 3 Functions in Redundant Pathways with Dishevelled 1 and 2 in Normal Cardiac Outflow Tract, Cochlea, and Neural Tube Development
Dishevelled (Dvl) proteins are important signaling components of both the canonical ฮฒ-catenin/Wnt pathway, which controls cell proliferation and patterning, and the planar cell polarity (PCP) pathway, which coordinates cell polarity within a sheet of cells and also directs convergent extension cell (CE) movements that produce narrowing and elongation of the tissue. Three mammalian Dvl genes have been identified and the developmental roles of Dvl1 and Dvl2 were previously determined. Here, we identify the functions of Dvl3 in development and provide evidence of functional redundancy among the three murine Dvls. Dvl3โ/โ mice died perinatally with cardiac outflow tract abnormalities, including double outlet right ventricle and persistent truncus arteriosis. These mutants also displayed a misorientated stereocilia in the organ of Corti, a phenotype that was enhanced with the additional loss of a single allele of the PCP component Vangl2/Ltap (LtapLp/+). Although neurulation appeared normal in both Dvl3โ/โ and LtapLp/+ mutants, Dvl3+/โ;LtapLp/+ combined mutants displayed incomplete neural tube closure. Importantly, we show that many of the roles of Dvl3 are also shared by Dvl1 and Dvl2. More severe phenotypes were observed in Dvl3 mutants with the deficiency of another Dvl, and increasing Dvl dosage genetically with Dvl transgenes demonstrated the ability of Dvls to compensate for each other to enable normal development. Interestingly, global canonical Wnt signaling appeared largely unaffected in the double Dvl mutants, suggesting that low Dvl levels are sufficient for functional canonical Wnt signals. In summary, we demonstrate that Dvl3 is required for cardiac outflow tract development and describe its importance in the PCP pathway during neurulation and cochlea development. Finally, we establish several developmental processes in which the three Dvls are functionally redundant
Murine Dishevelled 3 Functions in Redundant Pathways with Dishevelled 1 and 2 in Normal Cardiac Outflow Tract, Cochlea, and Neural Tube Development
Dishevelled (Dvl) proteins are important signaling components of both the canonical ฮฒ-catenin/Wnt pathway, which controls cell proliferation and patterning, and the planar cell polarity (PCP) pathway, which coordinates cell polarity within a sheet of cells and also directs convergent extension cell (CE) movements that produce narrowing and elongation of the tissue. Three mammalian Dvl genes have been identified and the developmental roles of Dvl1 and Dvl2 were previously determined. Here, we identify the functions of Dvl3 in development and provide evidence of functional redundancy among the three murine Dvls. Dvl3โ/โ mice died perinatally with cardiac outflow tract abnormalities, including double outlet right ventricle and persistent truncus arteriosis. These mutants also displayed a misorientated stereocilia in the organ of Corti, a phenotype that was enhanced with the additional loss of a single allele of the PCP component Vangl2/Ltap (LtapLp/+). Although neurulation appeared normal in both Dvl3โ/โ and LtapLp/+ mutants, Dvl3+/โ;LtapLp/+ combined mutants displayed incomplete neural tube closure. Importantly, we show that many of the roles of Dvl3 are also shared by Dvl1 and Dvl2. More severe phenotypes were observed in Dvl3 mutants with the deficiency of another Dvl, and increasing Dvl dosage genetically with Dvl transgenes demonstrated the ability of Dvls to compensate for each other to enable normal development. Interestingly, global canonical Wnt signaling appeared largely unaffected in the double Dvl mutants, suggesting that low Dvl levels are sufficient for functional canonical Wnt signals. In summary, we demonstrate that Dvl3 is required for cardiac outflow tract development and describe its importance in the PCP pathway during neurulation and cochlea development. Finally, we establish several developmental processes in which the three Dvls are functionally redundant
RGB-D Odometry and SLAM
The emergence of modern RGB-D sensors had a significant impact in many
application fields, including robotics, augmented reality (AR) and 3D scanning.
They are low-cost, low-power and low-size alternatives to traditional range
sensors such as LiDAR. Moreover, unlike RGB cameras, RGB-D sensors provide the
additional depth information that removes the need of frame-by-frame
triangulation for 3D scene reconstruction. These merits have made them very
popular in mobile robotics and AR, where it is of great interest to estimate
ego-motion and 3D scene structure. Such spatial understanding can enable robots
to navigate autonomously without collisions and allow users to insert virtual
entities consistent with the image stream. In this chapter, we review common
formulations of odometry and Simultaneous Localization and Mapping (known by
its acronym SLAM) using RGB-D stream input. The two topics are closely related,
as the former aims to track the incremental camera motion with respect to a
local map of the scene, and the latter to jointly estimate the camera
trajectory and the global map with consistency. In both cases, the standard
approaches minimize a cost function using nonlinear optimization techniques.
This chapter consists of three main parts: In the first part, we introduce the
basic concept of odometry and SLAM and motivate the use of RGB-D sensors. We
also give mathematical preliminaries relevant to most odometry and SLAM
algorithms. In the second part, we detail the three main components of SLAM
systems: camera pose tracking, scene mapping and loop closing. For each
component, we describe different approaches proposed in the literature. In the
final part, we provide a brief discussion on advanced research topics with the
references to the state-of-the-art.Comment: This is the pre-submission version of the manuscript that was later
edited and published as a chapter in RGB-D Image Analysis and Processin
The serious games ecosystem: Interdisciplinary and intercontextual praxis
This chapter will situate academia in relation to serious games commercial production and contextual adoption, and vice-versa. As a researcher it is critical to recognize that academic research of serious games does not occur in a vaccum. Direct partnerships between universities and commercial organizations are increasingly common, as well as between research institutes and the contexts that their serious games are deployed in. Commercial production of serious games and their increased adoption in non-commercial contexts will influence academic research through emerging impact pathways and funding opportunities. Adding further complexity is the emergence of commercial organizations that undertake their own research, and research institutes that have inhouse commercial arms. To conclude, we explore how these issues affect the individual researcher, and offer considerations for future academic and industry serious games projects
Timescapes of Himalayan hydropower: promises, project life cycles, and precarities
In this paper, we review the existing social science scholarship focused on hydropower development in the Himalayan region, using an interpretive lens attuned to issues of time and temporality. While the spatial politics of Himalayan hydropower are well examined in the literature, an explicit examination of temporal politics is lacking. In this paper, we present a conceptual framework organized around the heuristic of timescapes, highlighting temporal themes implicit in the existing literature. In three sections, we explore the temporal politics of anticipation that shape hydropower dreams, the intersecting temporalities and rhythms that modulate the life cycles of hydropower projects, and the ways that geological and hydrological time affect both hydropower development and broader Himalayan futures. Along the way, we pose a series of questions useful for framing future research given the significant climatic, geophysical, and sociopolitical changes underway in the Himalayan bioregion, calling for greater analytical attention to time, temporality, and temporal ethics in future studies of hydropower in the Himalayas and beyond.Austin Lord, Georgina Drew, Mabel Denzin Gerga
Early-life gut dysbiosis linked to juvenile mortality in ostriches
Imbalances in the gut microbial community (dysbiosis) of vertebrates have been associated with several gastrointestinal and autoimmune diseases. However, it is unclear which taxa are associated with gut dysbiosis, and if particular gut regions or specific time periods during ontogeny are more susceptible. We also know very little of this process in non-model organisms, despite an increasing realization of the general importance of gut microbiota for health
Inhibition of the Wnt Signaling Pathway by Idax, a Novel Dvl-Binding Protein
In attempting to clarify the roles of Dvl in the Wnt signaling pathway, we identified a novel protein which binds to the PDZ domain of Dvl and named it Idax (for inhibition of the Dvl and Axin complex). Idax and Axin competed with each other for the binding to Dvl. Immunocytochemical analyses showed that Idax was localized to the same place as Dvl in cells and that expression of Axin inhibited the colocalization of Dvl and Idax. Further, Wnt-induced accumulation of ฮฒ-catenin and activation of T-cell factor in mammalian cells were suppressed by expression of Idax. Expression of Idax in Xenopus embryos induced ventralization with a reduction in the expression of siamois, a Wnt-inducible gene. Idax inhibited Wnt- and Dvl- but not ฮฒ-catenin-induced axis duplication. It is known that Dvl is a positive regulator in the Wnt signaling pathway and that the PDZ domain is important for this activity. Therefore, these results suggest that Idax functions as a negative regulator of the Wnt signaling pathway by directly binding to the PDZ domain of Dvl
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