67 research outputs found
Different functions of Notch activation on formation and maintenance of rhombomere boundaries
Ph.DDOCTOR OF PHILOSOPH
Optimal Discrete Beamforming of RIS-Aided Wireless Communications: an Inner Product Maximization Approach
This paper addresses non-convex optimization problems in communication
services using reconfigurable intelligent surfaces (RISs). Specifically, we
focus on optimal beamforming in RIS-aided communications, and formulate it as a
discrete inner product maximization problem. To solve this problem, we propose
a highly efficient divide-and-sort (DaS) search framework that guarantees
global optima with linear search complexity, both in the number of discrete
levels and reflecting cells. This approach is particularly effective for
large-scale problems. Our numerical studies and prototype experiments
demonstrate the speed and effectiveness of the proposed DaS. We also show that
for moderate resolution quantization (4-bits and above), there is no noticeable
difference between continuous and discrete phase configurations
Wireless Communications in Cavity: A Reconfigurable Boundary Modulation based Approach
This paper explores the potential wireless communication applications of
Reconfigurable Intelligent Surfaces (RIS) in reverberant wave propagation
environments. Unlike in free space, we utilize the sensitivity to boundaries of
the enclosed electromagnetic (EM) field and the equivalent perturbation of
RISs. For the first time, we introduce the framework of reconfigurable boundary
modulation in the cavities . We have proposed a robust boundary modulation
scheme that exploits the continuity of object motion and the mutation of the
codebook switch, which achieves pulse position modulation (PPM) by
RIS-generated equivalent pulses for wireless communication in cavities. This
approach achieves around 2 Mbps bit rate in the prototype and demonstrates
strong resistance to channel's frequency selectivity resulting in an extremely
low bit error rate (BER)
Temporal Notch activation through Notch1a and Notch3 is required for maintaining zebrafish rhombomere boundaries
In vertebrates, hindbrain is subdivided into seven segments termed rhombomeres and the interface between each rhombomere forms the boundary. Similar to the D/V boundary formation in Drosophila, Notch activation has been shown to regulate the segregation of rhombomere boundary cells. Here we further explored the function of Notch signaling in the formation of rhombomere boundaries. By using bodipy ceramide cell-labeling technique, we found that the hindbrain boundary is formed initially in mib mutants but lost after 24 hours post-fertilization (hpf). This phenotype was more severe in mibta52b allele than in mibtfi91 allele. Similarly, injection of su(h)-MO led to boundary defects in a dosage-dependent manner. Boundary cells were recovered in mibta52b mutants in the hdac1-deficient background, where neurogenesis is inhibited. Furthermore, boundary cells lost sensitivity to reduced Notch activation from 15 somite stage onwards. We also showed that knockdown of notch3 function in notch1a mutants leads to the loss of rhombomere boundary cells and causes neuronal hyperplasia, indicating that Notch1a and Notch3 play a redundant role in the maintenance of rhombomere boundary
Influence of optic disc-fovea distance on macular thickness measurements with OCT in healthy myopic eyes
Assessment of macular thickness is important in the evaluation of various eye diseases. This study aimed to determine the influence of the optic disc-fovea distance (DFD) on macular thickness in myopic eyes. We determined the DFD and the macular thickness in 138 eyes from 138 healthy myopic subjects using the Cirrus HD-OCT. Correlation analysis and multiple linear regression were performed to determine the influence of DFD, axial length, disc area, and β-PPA on macular thickness. To further remove the confounding effect of ocular magnification on the DFD and OCT scan area, a subgroup analysis was performed in eyes with a limited axial length range (24-25 mm). DFD was significantly correlated with both regional (central, inner, and outer ETDRS subfields) and overall average macular thickness at a Bonferroni corrected P value of 0.004 (r ranging from-0.27 to-0.47), except for the temporal outer (r =-0.15, P = 0.089) and inferior outer (r =-0.22, P = 0.011) macular thickness. In the multivariable analysis, DFD was significantly associated with the average inner and outer macular thickness, the central subfield thickness, and the overall macular thickness (all P < 0.001), independent of ocular magnification and other covariates. Our findings indicate that eyes with a greater DFD have a lower macular thickness
Corneal Biomechanics Determination in Healthy Myopic Subjects
Purpose. To determine the corneal biomechanical properties by using the Ocular Response Analyzer™ and to investigate potential factors associated with the corneal biomechanics in healthy myopic subjects. Methods. 135 eyes from 135 healthy myopic subjects were included in this cross-sectional observational study. Cornea hysteresis (CH), corneal resistance factor (CRF), cornea-compensated intraocular pressure (IOPcc), and Goldmann-correlated intraocular pressure (IOPg) were determined with the Reichert Ocular Response Analyzer (ORA). Univariate and multivariate regression analyses were performed to investigate factors associated with corneal biomechanics. Results. The mean CH and CRF were 9.82±1.34 mmHg and 9.64±1.57 mmHg, respectively. In univariate regression analysis, CH was significantly correlated with axial length, refraction, central corneal thickness (CCT), and IOPg (r=-0.27, 0.23, 0.45, and 0.21, resp.; all with p≤0.015), but not with corneal curvature or age; CRF was significantly correlated with CCT and IOPg (r=0.52 and 0.70, resp.; all with p<0.001), but not with axial length/refraction, corneal curvature, or age. In multivariate regression analysis, axial length, IOPcc, and CCT were found to be independently associated with CH, while CCT and IOPg were associated with CRF. Conclusions. Both CH and CRF were positively correlated with CCT. Lower CH but not CRF was associated with increasing degree of myopia. Evaluation of corneal biomechanical properties should take CCT and myopic status into consideration
Relationship of corneal hysteresis and optic nerve parameters in healthy myopic subjects
Abstract The association between corneal biomechanical properties and glaucoma is an area of much interest. We determined the relationship between corneal hysteresis (CH) and optic nerve parameters in healthy myopic subjects in the current study. CH was measured with Reichert Ocular Response Analyzer in 108 eyes from 108 healthy myopic subjects. All subjects received retinal nerve fiber layer and optic disc imaging Cirrus HD-OCT, GDx ECC, and Heidelberg Retina Tomograph II. None of the tested optic nerve parameters showed statistical significance with CH by using correlation analysis. For RNFL parameters, there was a negative but not statistically significant correlation between CH and average RNFL thickness obtained with OCT (r = −0.15, p = 0.13). For optic disc parameters, there was a negative but not statistically significant correlation between CH and rim area measured with OCT (r = −0.10, p = 0.29). The current study did not find any statistically significant relationship between CH and optic nerve parameters as measured by all three imaging modalities in healthy myopic eyes. Therefore, the relationship observed previously in glaucoma subjects is likely coming to fruition as optic nerve damage is caused by the disease
Application of the ISNT rules on retinal nerve fibre layer thickness and neuroretinal rim area in healthy myopic eyes
PurposeWe determined the applicability of inferior>superior>nasal>temporal (ISNT) rules on retinal nerve fibre layer (RNFL) thickness and rim area and evaluated the impact of various ocular factors on the performance of the ISNT rules in healthy myopic eyes. MethodsA total of 138 eyes from 138 healthy myopic subjects were included in this cross-sectional observational study. The peripapillary RNFL and optic disc in each eye were imaged with Cirrus HD optical coherence tomography (OCT) and Heidelberg Retina Tomograph II (HRT2), respectively. The performance of the inferior>superior (IS), inferior>superior>nasal>temporal (IST) and ISNT rules on RNFL thickness and rim area was determined and compared between low-to-moderate myopia and high myopia. The effects of ocular factors [including axial length, disc area, disc tilt, disc torsion, disc-fovea angle (DFA) and retina artery angle] on the performance of ISNT rules were evaluated with logistic regression analysis. ResultsThe mean axial length and refractive error were 25.571.09mm (range, 22.52-28.77mm) and -5.12 +/- 2.30D [range, -9.63 to -0.50dioptres (D)], respectively. Sixty-three per cent of the healthy eyes were compliant with the ISNT rule on rim area, while ISNT rule on RNFL thickness was followed in only 11.6% of the included eyes. For rim area, smaller disc area was significantly associated with increased compliance of the IS rule (odds ratio: 0.46, p=0.039), IST rule (odds ratio: 0.46, p=0.037) and ISNT rule (odds ratio: 0.44, p=0.030). For RNFL thickness, greater DFA was significantly associated with increased compliance of the IS and IST rules (odds ratio: 1.30, p ConclusionIn healthy myopic subjects, 88.4% and 37% of eyes did not comply with the ISNT rule on RNFL thickness and rim area, respectively. Due to significant low compliance in healthy eyes, the ISNT rule and its variants have limited potential utility in diagnosing glaucoma in myopic subjects
MOF Acetylates the Histone Demethylase LSD1 to Suppress Epithelial-to-Mesenchymal Transition
SummaryThe histone demethylase LSD1 facilitates epithelial-to-mesenchymal transition (EMT) and tumor progression by repressing epithelial marker expression. However, little is known about how its function may be modulated. Here, we report that LSD1 is acetylated in epithelial but not mesenchymal cells. Acetylation of LSD1 reduces its association with nucleosomes, thus increasing histone H3K4 methylation at its target genes and activating transcription. The MOF acetyltransferase interacts with LSD1 and is responsible for its acetylation. MOF is preferentially expressed in epithelial cells and is downregulated by EMT-inducing signals. Expression of exogenous MOF impedes LSD1 binding to epithelial gene promoters and histone demethylation, thereby suppressing EMT and tumor invasion. Conversely, MOF depletion enhances EMT and tumor metastasis. In human cancer, high MOF expression correlates with epithelial markers and a favorable prognosis. These findings provide insight into the regulation of LSD1 and EMT and identify MOF as a critical suppressor of EMT and tumor progression
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