30 research outputs found
EVE: Efficient zero-shot text-based Video Editing with Depth Map Guidance and Temporal Consistency Constraints
Motivated by the superior performance of image diffusion models, more and
more researchers strive to extend these models to the text-based video editing
task. Nevertheless, current video editing tasks mainly suffer from the dilemma
between the high fine-tuning cost and the limited generation capacity. Compared
with images, we conjecture that videos necessitate more constraints to preserve
the temporal consistency during editing. Towards this end, we propose EVE, a
robust and efficient zero-shot video editing method. Under the guidance of
depth maps and temporal consistency constraints, EVE derives satisfactory video
editing results with an affordable computational and time cost. Moreover,
recognizing the absence of a publicly available video editing dataset for fair
comparisons, we construct a new benchmark ZVE-50 dataset. Through comprehensive
experimentation, we validate that EVE could achieve a satisfactory trade-off
between performance and efficiency. We will release our dataset and codebase to
facilitate future researchers
Dual-Modal Attention-Enhanced Text-Video Retrieval with Triplet Partial Margin Contrastive Learning
In recent years, the explosion of web videos makes text-video retrieval
increasingly essential and popular for video filtering, recommendation, and
search. Text-video retrieval aims to rank relevant text/video higher than
irrelevant ones. The core of this task is to precisely measure the cross-modal
similarity between texts and videos. Recently, contrastive learning methods
have shown promising results for text-video retrieval, most of which focus on
the construction of positive and negative pairs to learn text and video
representations. Nevertheless, they do not pay enough attention to hard
negative pairs and lack the ability to model different levels of semantic
similarity. To address these two issues, this paper improves contrastive
learning using two novel techniques. First, to exploit hard examples for robust
discriminative power, we propose a novel Dual-Modal Attention-Enhanced Module
(DMAE) to mine hard negative pairs from textual and visual clues. By further
introducing a Negative-aware InfoNCE (NegNCE) loss, we are able to adaptively
identify all these hard negatives and explicitly highlight their impacts in the
training loss. Second, our work argues that triplet samples can better model
fine-grained semantic similarity compared to pairwise samples. We thereby
present a new Triplet Partial Margin Contrastive Learning (TPM-CL) module to
construct partial order triplet samples by automatically generating
fine-grained hard negatives for matched text-video pairs. The proposed TPM-CL
designs an adaptive token masking strategy with cross-modal interaction to
model subtle semantic differences. Extensive experiments demonstrate that the
proposed approach outperforms existing methods on four widely-used text-video
retrieval datasets, including MSR-VTT, MSVD, DiDeMo and ActivityNet.Comment: Accepted by ACM MM 202
Inhibition of HDAC activity directly reprograms murine embryonic stem cells to trophoblast stem cells
Embryonic stem cells (ESCs) can differentiate into all cell types of the embryonic germ layers. ESCs can also generate totipotent 2C-like cells and trophectodermal cells. However, these latter transitions occur at low frequency due to epigenetic barriers, the nature of which is not fully understood. Here, we show that treating mouse ESCs with sodium butyrate (NaB) increases the population of 2C-like cells and enables direct reprogramming of ESCs into trophoblast stem cells (TSCs) without a transition through a 2C-like state. Mechanistically, NaB inhibits histone deacetylase activities in the LSD1-HDAC1/2 corepressor complex. This increases acetylation levels in the regulatory regions of both 2C- and TSC-specific genes, promoting their expression. In addition, NaB-treated cells acquire the capacity to generate blastocyst-like structures that can develop beyond the implantation stage in vitro and form deciduae in vivo. These results identify how epigenetics restrict the totipotent and trophectoderm fate in mouse ESCs.</p
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Encroachment order and spatial patterns of broad-leaf tree species in the naturalization of a Cunninghamia lanceolata plantation
Authors of the article state that the aim of this study was to understand the encroachment order, spatial patterns, interspecific associations, and species diversity of a Cunninghamia lanceolata plantation and to provide context for how to improve the spatial structure of C. lanceolata plantations. Their results show that the encroachment of broad-leaf trees into the C. lanceolata plantation followed a clear successional sequence of tree community assembly: intolerant tree species encroachment first, such as Alniphyllum fortunei and Liquidambar formosana, encroached; neutral tree species then encroachment, such as Daphniphyllum oldhamii and Schima superba, and shade-tolerant tree species encroachment last, such as Castanopsis eyrei and Castanopsis tibetana
Strong Law of Large Numbers for Countable Markov Chains Indexed by an Infinite Tree with Uniformly Bounded Degree
We study the strong law of large numbers for the frequencies of occurrence of states and ordered couples of states for countable Markov chains indexed by an infinite tree with uniformly bounded degree, which extends the corresponding results of countable Markov chains indexed by a Cayley tree and generalizes the relative results of finite Markov chains indexed by a uniformly bounded tree
Synthesis, Antimicrobial, Moisture Absorption and Retention Activities of Kojic Acid-Grafted Konjac Glucomannan Oligosaccharides
Kojic acid (KA) with antibacterial activities produced by fermentation was grafted onto konjac glucomannan oligosaccharide (KGO) composed of glucose and mannose linked by β-1,4 glycosidic bonds. A novel KGO derivative, konjac glucomannan oligosaccharide kojic acid (KGOK) possessing both moisture retention and antibacterial activities was synthesized. The structure of KGOK was characterized and analyzed by thermogravimetric analysis (TG), XRD, UV–vis absorption, FTIR, and 1H NMR. The analysis results suggest that KA was linked to the KGO molecular chain through a covalent bond, and the reaction site of KA was the methylol group. The studies demonstrate that KGOK maintained the excellent moisture absorption and retention properties of KGO and the good antibacterial activities of KA. The minimum inhibitory concentration (MIC) of KGOK is 2 mg/mL for Staphylococcus aureus, Staphylococcus epidermidis, Shewanella putrefaciens, and Salmonella enterica, while its MIC is 3 mg/mL for Escherichia coli. The multi-functionality of the KGOK synthesized from natural sources provides a theoretical foundation for their potential applications in the preservation of food, beverage, aquatic, and cosmetic products