Single-to-Dual-View Adaptation for Egocentric 3D Hand Pose Estimation

The pursuit of accurate 3D hand pose estimation stands as a keystone for understanding human activity in the realm of egocentric vision. The majority of existing estimation methods still rely on single-view images as input, leading to potential limitations, e.g., limited field-of-view and ambiguity in depth. To address these problems, adding another camera to better capture the shape of hands is a practical direction. However, existing multi-view hand pose estimation methods suffer from two main drawbacks: 1) Requiring multi-view annotations for training, which are expensive. 2) During testing, the model becomes inapplicable if camera parameters/layout are not the same as those used in training. In this paper, we propose a novel Single-to-Dual-view adaptation (S2DHand) solution that adapts a pre-trained single-view estimator to dual views. Compared with existing multi-view training methods, 1) our adaptation process is unsupervised, eliminating the need for multi-view annotation. 2) Moreover, our method can handle arbitrary dual-view pairs with unknown camera parameters, making the model applicable to diverse camera settings. Specifically, S2DHand is built on certain stereo constraints, including pair-wise cross-view consensus and invariance of transformation between both views. These two stereo constraints are used in a complementary manner to generate pseudo-labels, allowing reliable adaptation. Evaluation results reveal that S2DHand achieves significant improvements on arbitrary camera pairs under both in-dataset and cross-dataset settings, and outperforms existing adaptation methods with leading performance. Project page: https://github.com/MickeyLLG/S2DHand.Comment: This paper is accepted by CVPR2024. Code will be released at https://github.com/ut-vision/S2DHan

The impact of building up the limb muscle mass by the resistance exercise with the intake of milk in middle-aged and elderly women

Background: In the rapidly aging Japanese society, the most serious disorder to prevent is sarcopenia for extending healthy life expectancy. Objective: This study was carried out to clarify whether five kinds of specific and simple resistance exercise performing at home for the short term (42 days) with theintake of whole milk could help to increase the limb muscle mass in middle-aged and elderly women. Participants and measurements: Subjects were 39 healthy women aged 50 to 80 years who gave the consent to participate in the present study. Body composition, physical fitness, food and nutrient intake were measured. Oral glucose-tolerance test (OGTT) was also performed. Groups and results: Subjects were categorized in two groups; Group I with the increase of the limb muscle mass after exercise and Group II with no increase. Body weight before exercise (Group I, 51.6±5.5 kg vs Group II, 58.5±10.3 kg), the body mass index (BMI) (21.7±2.5 kg/m2 vs 24.3±3.9 kg/m2), the limb muscle mass (14.4±1.3 kg vs 15.6±2.0 kg), the skeletal muscle mass index (SMI) (6.0±0.5 kg/m2 vs 6.5±0.7 kg/m2), were all significantly high in Group II. The intake of milk before exercise in Group I (162.1±103.7 g/day) was significantly higher than in Group II (92.5±63.3 g/day). The blood glucose level at 30 min after glucose loading in Group I before exercise was significantly higher than that in Group Ⅱ (199.3 ± 31.1 mg/dl vs 177.0±34.1 mg/dl). Conclusion: The subjects in Group I could successfully increase the limb muscle mass, but the subjects in Group II, whose weight, BMI, the limb muscle mass were significantly high before exercise, could not increase the muscle mass by resistance exercise with the intake of milk. It was considered that the resistance exercise carried out in this study was not strong enough for Group II. We assumed that the BMI value could be the indicator of the strength of exercise for building up the muscle mass in middle-aged and elderly individuals

Exo2EgoDVC: Dense Video Captioning of Egocentric Procedural Activities Using Web Instructional Videos

We propose a novel benchmark for cross-view knowledge transfer of dense video captioning, adapting models from web instructional videos with exocentric views to an egocentric view. While dense video captioning (predicting time segments and their captions) is primarily studied with exocentric videos (e.g., YouCook2), benchmarks with egocentric videos are restricted due to data scarcity. To overcome the limited video availability, transferring knowledge from abundant exocentric web videos is demanded as a practical approach. However, learning the correspondence between exocentric and egocentric views is difficult due to their dynamic view changes. The web videos contain mixed views focusing on either human body actions or close-up hand-object interactions, while the egocentric view is constantly shifting as the camera wearer moves. This necessitates the in-depth study of cross-view transfer under complex view changes. In this work, we first create a real-life egocentric dataset (EgoYC2) whose captions are shared with YouCook2, enabling transfer learning between these datasets assuming their ground-truth is accessible. To bridge the view gaps, we propose a view-invariant learning method using adversarial training in both the pre-training and fine-tuning stages. While the pre-training is designed to learn invariant features against the mixed views in the web videos, the view-invariant fine-tuning further mitigates the view gaps between both datasets. We validate our proposed method by studying how effectively it overcomes the view change problem and efficiently transfers the knowledge to the egocentric domain. Our benchmark pushes the study of the cross-view transfer into a new task domain of dense video captioning and will envision methodologies to describe egocentric videos in natural language

Evidence for hydrogen generation in laser- or spark-induced cavitation bubbles

The growing use of focused lasers or electric sparks to generate cavitation bubbles raises concerns about the possible alteration of gas content during the initiation process and its effect on bubble dynamics. We provide experimental evidence that hydrogen molecules are produced for such plasma-induced bubbles. We performed spectral analysis of the light emitted by the plasma and monitored the dissolved hydrogen concentration in water. The mass of dissolved hydrogen was found proportional to the potential energy of the rebound bubble for both laser and spark methods. Nevertheless, hydrogen concentration was found 2.7 times larger with the spark

Gene Suppression of Mouse Testis In Vivo Using Small Interfering RNA Derived from Plasmid Vectors

We evaluated whether inhibiting gene expression by small interfering RNA (siRNA) can be used for an in vivo model using a germ cell-specific gene (Tex101) as a model target in mouse testis. We generated plasmid-based expression vectors of siRNA targeting the Tex101 gene and transfected them into postnatal day 10 mouse testes by in vivo electroporation. After optimizing the electroporation conditions using a vector transfected into the mouse testis, a combination of high- and low-voltage pulses showed excellent transfection efficiency for the vectors with minimal tissue damage, but gene suppression was transient. Gene suppression by in vivo electroporation may be helpful as an alternative approach when designing experiments to unravel the basic role of testicular molecules

In situ detection of methylated DNA by histo endonuclease-linked detection of methylated DNA sites: a new principle of analysis of DNA methylation.

For a better understanding of epigenetic regulation of cell differentiation, it is important to analyze DNA methylation at a specific site. Although previous studies described methylation of isolated DNA extracted from cells and tissues using a combination of appropriate restriction endonucleases, no application to tissue cell level has been reported. Here, we report a new method, named histo endonuclease-linked detection of methylation sites of DNA (HELMET), designed to detect methylation sites of DNA with a specific sequences in a tissue section. In this study, we examined changes in the methylation level of CCGG sites during spermatogenesis in paraffin-embedded sections of mouse testis. In principle, the 3\u27-OH ends of DNA strand breaks in a section were firstly labeled with a mixture of dideoxynucleotides by terminal deoxynucleotidyl transferase (TdT), not to be further elongated by TdT. Then the section was digested with Hpa II, resulting in cutting the center portion of non-methylated CCGG. The cutting sites were labeled with biotin-16-dUTP by TdT. Next, the section was treated with Msp I, which can cut the CCGG sequence irrespective of the presence or absence of methylation of the second cytosine, and the cutting sites were labeled with digoxigenin-11-dUTP by TdT. Finally, both biotin and digoxigenin were visualized by enzyme- or fluorescence-immunohistochemistry. Using this method, we found hypermethylation of CCGG sites in most of the germ cells although non-methylated CCGG were colocalized in elongated spermatids. Interestingly, some TUNEL-positive germ cells, which are frequent in mammalian spermatogenesis, became markedly Hpa II-reactive, indicating that the CCGG sites may be demethylated during apoptosis