An exact sinΘ\Theta formula for matrix perturbation analysis and its applications

In this paper, we establish a useful set of formulae for the $\sin\Theta$ distance between the original and the perturbed singular subspaces. These formulae explicitly show that how the perturbation of the original matrix propagates into singular vectors and singular subspaces, thus providing a direct way of analyzing them. Following this, we derive a collection of new results on SVD perturbation related problems, including a tighter bound on the $\ell_{2,\infty}$ norm of the singular vector perturbation errors under Gaussian noise, a new stability analysis of the Principal Component Analysis and an error bound on the singular value thresholding operator. For the latter two, we consider the most general rectangular matrices with full matrix rank

Molecular Characterization of Osmotin and Four Plasmodesmata Callose Binding Protein Homologs from Arabidopsis in Turnip Mosaic Virus Infection

Plant viruses enter neighboring cells through plasmodesmata (PD), plasma membrane-lined microchannels that traverse the cell wall, to establish systemic infection. This intercellular movement process relies on the coordinated action of virus-encoded proteins and host proteins, especially PD-localized ones. To better understand the involvement of PD in viral infection, our lab previously conducted a quantitative, comparative proteomic study on the PD-enriched fraction from Nicotiana benthamiana leaves infected by turnip mosaic virus (TuMV). Osmotin (OSM, a PR-5 related protein) and plasmodesmata callose-binding protein 3 (PDCB3) are among the significantly differentially accumulated proteins in response to TuMV infection. In this thesis, I employed the TuMV-Arabidopsis thaliana pathosystem and characterized OSM (AtOSM34) and four PDCB homologs (AtPDCB1, AtPDCB2, AtPDCB3 and AtPDCB5) from Arabidopsis in TuMV infection. I found that in Arabidopsis, AtOSM34 expression is upregulated, while AtPDCBs are downregulated after TuMV infection, consistent with previous proteomic data derived from N. benthamiana. Deficiency of osmotin in A. thaliana and N. benthamiana inhibits TuMV infection, whereas overexpression of AtOSM34 promotes viral replication and intercellular movement. Knockout of AtPDCB5 promotes TuMV infection but knockout of any of the other three AtPDCBsdoes not affect TuMV infection. As PDCB1, PDCB2 and PDCB3 may have functional redundancy, I generated double and triple knockout mutants. Only the triple knockout mutant shows enhanced TuMV infection, suggesting theses three AtPDCBs highly likely do have functional redundancy. Moreover, overexpression of AtPDCBs inhibits TuMV infection and reduces PD permeability by stimulating callose deposition. Overexpression of AtPDCB5 inhibits TuMV intercellular movement. In this thesis I also found that AtOSM34 and AtPDCBs are localized at PD and redistributed to virus replication complexes (VRCs) in TuMV-infected cells. Recruitment of AtOSM34 and AtPDCBs to VRCs is likely through the interaction with 6K2, the virus-encoded integral membrane protein that induces the formation of VRC-associated membrane structures. Overexpression of AtOSM34 increases PD permeability, reduces PD callose deposition and promotes TuMV intercellular movement. Overexpression of AtOSM34 also compromises antiviral resistance mediated by reactive oxygen species (ROS) burst. Taken together, these data suggest that OSM functions as a proviral host factor and PDCBs play antiviral roles in TuMV infection

Abusive Supervision, Leader-Member Exchange, and Creativity: A Multilevel Examination

Despite the growing attention on the topic of abusive supervision, how abusive supervision affects individual and team creativity have not yet been thoroughly investigated. Drawn from the perspective of leader-member exchange (LMX), the current study develops a multilevel model to describe the relationships between abusive supervision and creativity at both team and individual levels, with a focus on the roles played by team-level leader-member exchange (TLMX) and LMX differentiation (DLMX). Based on data collected from 319 team members and their team leaders in 71 teams, the results show that abusive supervision has a negative relationship with TLMX, a practice that is conducive to both team and individual creativity. At the team level, the negative relationship between abusive supervision and TLMX is lessened by a higher level of DLMX. In addition, the positive relationship between TLMX and team creativity is weakened by a higher level of DLMX. Theoretical and practical implications of the findings are discussed

PixelFolder: An Efficient Progressive Pixel Synthesis Network for Image Generation

Pixel synthesis is a promising research paradigm for image generation, which can well exploit pixel-wise prior knowledge for generation. However, existing methods still suffer from excessive memory footprint and computation overhead. In this paper, we propose a progressive pixel synthesis network towards efficient image generation, coined as PixelFolder. Specifically, PixelFolder formulates image generation as a progressive pixel regression problem and synthesizes images by a multi-stage paradigm, which can greatly reduce the overhead caused by large tensor transformations. In addition, we introduce novel pixel folding operations to further improve model efficiency while maintaining pixel-wise prior knowledge for end-to-end regression. With these innovative designs, we greatly reduce the expenditure of pixel synthesis, e.g., reducing 90% computation and 57% parameters compared to the latest pixel synthesis method called CIPS. To validate our approach, we conduct extensive experiments on two benchmark datasets, namely FFHQ and LSUN Church. The experimental results show that with much less expenditure, PixelFolder obtains new state-of-the-art (SOTA) performance on two benchmark datasets, i.e., 3.77 FID and 2.45 FID on FFHQ and LSUN Church, respectively. Meanwhile, PixelFolder is also more efficient than the SOTA methods like StyleGAN2, reducing about 74% computation and 36% parameters, respectively. These results greatly validate the effectiveness of the proposed PixelFolder.Comment: 11 pages, 7 figure

Future Arctic Climate Change in CMIP6 Strikingly Intensified by NEMO‐Family Climate Models

Climate change in the Arctic has substantial impacts on human life and ecosystems both within and beyond the Arctic. Our analysis of CMIP6 simulations shows that some climate models project much larger Arctic climate change than other models, including changes in sea ice, ocean mixed layer, air-sea heat flux, and surface air temperature in wintertime. In particular, dramatic enhancement of Arctic Ocean convection down to a few hundred meters is projected in these models but not in others. Interestingly, these models employ the same ocean model family (NEMO) while the choice of models for the atmosphere and sea ice varies. The magnitude of Arctic climate change is proportional to the strength of the increase in poleward ocean heat transport, which is considerably higher in this group of models. Establishing the plausibility of this group of models with high Arctic climate sensitivity to anthropogenic forcing is imperative given the implied ramifications

Synergistic Improvement of Production, Economic Return and Sustainability in the Tea Industry through Ecological Pest Management

The use of ecological principles to manage plant pests has attracted renewed attention, but our knowledge related to the contributions of ecological pest management to social and natural sustainability is fragmented. In this study, we compared the performance and resilience of tea production and the economic benefits of tea ecological management (TEM) and tea conventional management (TCM). We show that TEM significantly improved tea biomass and quality, nutritional efficiency, and beneficial insects, but reduced seasonal variation. As a result, economic return increased by $8045/ha in the TEM mode compared to$6064/ha in the TCM mode. These results confirm that TEM is a promising production mode that can reconcile the conflict between the immediate and long-term service of agriculture. However, environmental improvements associated with organic pest control benefit society, and the government should provide adequate financial support to promote the production system

A quantitative technique to analyze and evaluate microstructures of skin hair follicles based on mueller matrix polarimetry

In this study, we propose a quantitative technique to analyze and evaluate microstructures of skin hair follicles based on Mueller Matrix transmission microscopy. We measure the Mueller matrix polar decomposition (MMPD) parameter images to reveal the characteristic linear birefringence distribution induced by hair follicles in mouse skin tissue samples. The results indicate that the Mueller matrix-derived parameters can be used to reveal the location and structural integrity of hair follicles. For accurate hair follicle location identification and quantitative structural evaluations, we use the image segmentation method, sliding window algorithm, and image texture analysis methods together to process the Mueller matrix-derived images. It is demonstrated that the hair follicle regions can be more accurately recognized, and their locations can be precisely identified based on the Mueller matrix-derived texture parameters. Moreover, comparisons between manual size measurement and polarimetric calculation results confirm that the Mueller matrix parameters have good performance for follicle size estimation. The results shown in this study suggest that the technique based on Mueller matrix microscopy can realize automatically hair follicle identification, detection, and quantitative evaluation. It has great potential in skin structure-related studies and clinical dermatological applications