398 research outputs found
Balancing WNT signaling in early forebrain development
During early forebrain development, the establishment of the regional identity of neural
progenitor cells (NPCs) relies on the integration of signals from multiple signaling
centers, including the WNT signaling pathway. WNT pathway is essential for
embryonic development and is regulated by LDL receptor related proteins (LRPs),
which act as co-receptors of frizzled. While the LRP family member - LRP5 and LRP6
are well known as co-receptors of frizzled, acting as the main receptor of WNT3a.
Recent evidence suggests that LRP4 also plays a role in the central nervous system.
My aim is to shed light on the common and distinct functions of LRP4 and LRP6 and
the interactions between LRP4/6 linked to the WNT pathway during early forebrain
development. To achieve this, a genetic approach was used to analyze the forebrain
development of LRP4-, LRP6-deficient mouse embryos, as well as Lrp4-/-; Lrp6-/-
double mutant mouse embryos at E9.5. High-resolution immunofluorescence imaging,
cell culture models and molecular biology approaches were employed to investigate
the effects of genetic inactivation of LRP4 and LRP6 on canonical WNT activity, mitotic
activity of forebrain neuronal precursors, and the development of NTDs.
The results of this study indicate that loss of LRP6 can lead to a developmental
disorder in E9.5 embryos, such as caudal truncation, neural tube defects (NTDs) and
forebrain hypoplasia. Importantly, loss of LRP4 can partially rescue these deficits in
Lrp6 null mutants. Specially, caudal truncation and impaired mitotic activity of forebrain
neuronal precursors observed in Lrp6-/- mutants were rescued in Lrp4-/-; Lrp6-/- double
mutants. However, cranial NTDs in LRP6-deficient mice were not ameliorated by
genetic ablation of Lrp4. Additionally, it was demonstrated that genetic inactivation of
LRP4 rescued impaired canonical WNT activity and the downstream targets in Lrp6-/-
mutants. Moreover, the data suggest that LRP4 and LRP6 also influence the
proliferation of human retinal pigment epithelial (hTERT RPE-1) cells in cell culture,
adding to their roles in embryonic development. Furthermore, the study revealed that
LRP4 modulates LRP6-dependent WNT signaling in a more general context, as
demonstrated in hTERT RPE-1 cells.
Overall, these results highlight the important and complex role of LRP4 and LRP6 in
forebrain development and WNT signaling regulation. The findings suggest that LRP4
2
acts as a negative regulator of LRP6-mediated canonical WNT signaling and plays a
critical role in the regulation of mitotic activity of neuronal precursors in the early
developing forebrain. Additionally, the results suggest that LRP5 or an as-yet
undetermined receptor can compensate for the loss of LRP6 as an FZD co-receptor
in the absence of LRP4. These findings provide new insights into the molecular
mechanisms that regulate forebrain development and may have implications for the
understanding and treatment of developmental disorders
An sTGC Prototype Readout System for ATLAS New-Small-Wheel Upgrade
This paper presents a readout system designed for testing the prototype of
Small-Strip Thin Gap Chamber (sTGC), which is one of the main detector
technologies used for ATLAS New-Small-Wheel Upgrade. This readout system aims
at testing one full-size sTGC quadruplet with cosmic muon triggers
Discriminating 1D new physics solutions in decays
The recent measurements of , , ,
, a set of CP-averaged angular observables for the decay, and its isospin partner by
the LHCb Collaboration, consistently hint at lepton universality violation in
the transitions. In this work, we first perform global fits to
the data and show that five one-dimensional scenarios, i.e,
, , , , and can best
explain the so-called B anamolies. Furthermore, we explore how these scenarios
can be distinguished from each other. For this purpose, we first study the
combinations of four angular asymmetries ~ and find that they
cannot distinguish the five new physics scenarios. We then show that a newly
constructed ratio can uniquely discriminate the five new physics
scenarios in proper intervals of if it can be measured with a percent
level precision.Comment: 16 pages, 6 figures; latest , data include
Patient Dropout Prediction in Virtual Health: A Multimodal Dynamic Knowledge Graph and Text Mining Approach
Virtual health has been acclaimed as a transformative force in healthcare
delivery. Yet, its dropout issue is critical that leads to poor health
outcomes, increased health, societal, and economic costs. Timely prediction of
patient dropout enables stakeholders to take proactive steps to address
patients' concerns, potentially improving retention rates. In virtual health,
the information asymmetries inherent in its delivery format, between different
stakeholders, and across different healthcare delivery systems hinder the
performance of existing predictive methods. To resolve those information
asymmetries, we propose a Multimodal Dynamic Knowledge-driven Dropout
Prediction (MDKDP) framework that learns implicit and explicit knowledge from
doctor-patient dialogues and the dynamic and complex networks of various
stakeholders in both online and offline healthcare delivery systems. We
evaluate MDKDP by partnering with one of the largest virtual health platforms
in China. MDKDP improves the F1-score by 3.26 percentage points relative to the
best benchmark. Comprehensive robustness analyses show that integrating
stakeholder attributes, knowledge dynamics, and compact bilinear pooling
significantly improves the performance. Our work provides significant
implications for healthcare IT by revealing the value of mining relations and
knowledge across different service modalities. Practically, MDKDP offers a
novel design artifact for virtual health platforms in patient dropout
management
Effects of time-varying in SNLS3 on constraining interacting dark energy models
It has been found that, for the Supernova Legacy Survey three-year (SNLS3)
data, there is strong evidence for the redshift-evolution of color-luminosity
parameter . In this paper, adopting the -cold-dark-matter (CDM)
model and considering its interacting extensions (with three kinds of
interaction between dark sectors), we explore the evolution of and its
effects on parameter estimation. In addition to the SNLS3 data, we also take
into account the Planck distance priors data of the cosmic microwave background
(CMB), the galaxy clustering (GC) data extracted from SDSS DR7 and BOSS, as
well as the direct measurement of Hubble constant from the Hubble Space
Telescope (HST) observation. We find that, for all the interacting dark energy
(IDE) models, adding a parameter of can reduce by 34,
indicating that is ruled out at 5.8 confidence level
(CL). Furthermore, it is found that varying can significantly change
the fitting results of various cosmological parameters: for all the dark energy
models considered in this paper, varying yields a larger
and a larger ; on the other side, varying yields a smaller for
the CDM model, but has no impact on for the three IDE models. This
implies that there is a degeneracy between and . Our work shows
that the evolution of is insensitive to the interaction between dark
sectors, and then highlights the importance of considering 's evolution
in the cosmology fits.Comment: 11 pages, 6 figures, 1 table; revised version accepted by EPJC. arXiv
admin note: substantial text overlap with arXiv:1310.6109, arXiv:1312.018
An integrated geophysical approach for investigating hydro-geological characteristics of a debris landslide in the Wenchuan Earthquake area
Debris landslides are one of the most widely distributed types of landslides in the Wenchuan earthquake area. The hydro-geological structure characteristics are the fundamental basis for stability evaluation, performing protection and administration of a landslide. The rock and soil mass of a debris landslide was highly non-uniform and preferential seepage paths were normally developed in it. Therefore, in situ identification of the underground water seepage system became particularly important. Recently, investigations on the seepage paths of underground water in debris landslides were restricted to indoor model testing and site observation, which were far from meeting the actual demand for landslide prevention and mitigation. To locate the seepage paths, we conducted survey work on a debris landslide seated in the Xishan Village, Li County, Sichuan Province, China, by combing four different geophysical methods. They were multichannel analysis of surface wave (MASW), electrical resistivity tomography (ERT), ground penetrating radar (GPR) and microtremor survey method (MSM). The geophysical interpretation was verified with field engineering surveys and monitoring data. The results suggested that a dendritic pipe-network seepage system usually developed in debris landslides. Varisized infiltration pipes showed the characteristics of inhomogeneity and concentration of the seepage. This work highlighted that geophysical parameters (shear wave velocity Vs, dielectric constant ε and resistivity value ρ) could provide reliable qualitative and quantitative information about the colluvial layer, bedrock interface, potential sliding surface and underground water seepage system of a landslide. The optimum combination of geophysical methods was suitable to survey the hydro-geological characteristics of debris landslides in the Wenchuan earthquake area
Robo-centric ESDF: A Fast and Accurate Whole-body Collision Evaluation Tool for Any-shape Robotic Planning
For letting mobile robots travel flexibly through complicated environments,
increasing attention has been paid to the whole-body collision evaluation. Most
existing works either opt for the conservative corridor-based methods that
impose strict requirements on the corridor generation, or ESDF-based methods
that suffer from high computational overhead. It is still a great challenge to
achieve fast and accurate whole-body collision evaluation. In this paper, we
propose a Robo-centric ESDF (RC-ESDF) that is pre-built in the robot body frame
and is capable of seamlessly applied to any-shape mobile robots, even for those
with non-convex shapes. RC-ESDF enjoys lazy collision evaluation, which retains
only the minimum information sufficient for whole-body safety constraint and
significantly speeds up trajectory optimization. Based on the analytical
gradients provided by RC-ESDF, we optimize the position and rotation of robot
jointly, with whole-body safety, smoothness, and dynamical feasibility taken
into account. Extensive simulation and real-world experiments verified the
reliability and generalizability of our method.Comment: Accepted at IROS 202
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