1,521 research outputs found
BEVBert: Multimodal Map Pre-training for Language-guided Navigation
Large-scale pre-training has shown promising results on the
vision-and-language navigation (VLN) task. However, most existing pre-training
methods employ discrete panoramas to learn visual-textual associations. This
requires the model to implicitly correlate incomplete, duplicate observations
within the panoramas, which may impair an agent's spatial understanding. Thus,
we propose a new map-based pre-training paradigm that is spatial-aware for use
in VLN. Concretely, we build a local metric map to explicitly aggregate
incomplete observations and remove duplicates, while modeling navigation
dependency in a global topological map. This hybrid design can balance the
demand of VLN for both short-term reasoning and long-term planning. Then, based
on the hybrid map, we devise a pre-training framework to learn a multimodal map
representation, which enhances spatial-aware cross-modal reasoning thereby
facilitating the language-guided navigation goal. Extensive experiments
demonstrate the effectiveness of the map-based pre-training route for VLN, and
the proposed method achieves state-of-the-art on four VLN benchmarks.Comment: ICCV 2023, project page: https://github.com/MarSaKi/VLN-BEVBer
Detrimental effect of Bisphenol S in mouse germ cell cyst breakdown and primordial follicle assembly
The female reproductive lifespan is largely determined by the size of primordial follicle pool, which is established in early life. Bisphenol S (BPS), frequently present in plastic products used in daily life, has been demonstrated as an exogenous estrogen-like endocrine disrupting chemical interfering with the endocrine and reproductive systems. However, the molecular mechanisms of its reproductive toxicity remain to be determined. In the present study, we focused on the effect of BPS on the early ovarian folliculogenesis of mice. Our in vivo experiments showed that the treatment with BPS at 2 and 10 μg/kg body weight/day for 3 days induced abnormal germ cell cyst breakdown and primordial follicle assembly in the mouse ovary, further affecting later ovarian differentiation and reducing oocyte quality. In addition, our in vitro study demonstrated that BPS could interact with estrogen receptors (ERs) to induce phosphorylation of JNKs, which is responsible for reducing oocyte adhesion in cysts. Meanwhile, BPS exposure up-regulated Notch signaling pathway to increase the proliferation of granulosa cells precursors. Our study provided new evidence for the adverse effects of BPS on female reproduction, especially after perinatal exposure, and elucidated how it works
Uniparental Genetic Analyses Reveal the Major Origin of Fujian Tanka from Ancient Indigenous Daic Populations
The Fujian Tanka people are officially classified as a southern Han ethnic group while they have customs similar to Daic and Austronesion people. Whether they originated in Han or Daic people, there is no consensus. Three hypotheses have been proposed to explain the origin of this group: 1) the Han Chinese origin, 2) the ancient Daic origin, 3) and the admixture between Daic and Han. In this study, we address this issue by analyzing the paternal Y chromosome and maternal mtDNA variation of 62 Fujian Tanka and 25 neighboring Han in Fujian. We found that the southern East Asian predominant haplogroups, e.g. O1a1a-P203 and O1b1a1a-M95 of Y chromosome and F2a, M7c1, and F1a1 of mtDNA, reach relatively high frequencies in Tanka. The interpopulation comparison reveals that the Tanka have a closer affinity with Daic populations than with Han Chinese in paternal lineages while are closely clustered with southern Han populations such as Hakka and Chaoshanese in maternal lineages. Network and haplotype-sharing analyses also support the admixture hypothesis. The Fujian Tanka mainly originate from the ancient indigenous Daic people and have only limited gene flows from Han Chinese populations. Notably, the divergence time inferred by the Tanka-specific haplotypes indicates that the formation of Fujian Tanka was a least 1033.8-1050.6 years before present (the early Northern Song Dynasty), indicating that they are indigenous population, not late Daic migrants from southwestern China
Uniparental Genetic Analyses Reveal the Major Origin of Fujian Tanka from Ancient Indigenous Daic Populations
The Fujian Tanka people are officially classified as a southern Han ethnic group while they have customs similar to Daic and Austronesion people. Whether they originated in Han or Daic people, there is no consensus. Three hypotheses have been proposed to explain the origin of this group: 1) the Han Chinese origin, 2) the ancient Daic origin, 3) and the admixture between Daic and Han. In this study, we address this issue by analyzing the paternal Y chromosome and maternal mtDNA variation of 62 Fujian Tanka and 25 neighboring Han in Fujian. We found that the southern East Asian predominant haplogroups, e.g. O1a1a-P203 and O1b1a1a-M95 of Y chromosome and F2a, M7c1, and F1a1 of mtDNA, reach relatively high frequencies in Tanka. The interpopulation comparison reveals that the Tanka have a closer affinity with Daic populations than with Han Chinese in paternal lineages while are closely clustered with southern Han populations such as Hakka and Chaoshanese in maternal lineages. Network and haplotype-sharing analyses also support the admixture hypothesis. The Fujian Tanka mainly originate from the ancient indigenous Daic people and have only limited gene flows from Han Chinese populations. Notably, the divergence time inferred by the Tanka-specific haplotypes indicates that the formation of Fujian Tanka was a least 1033.8-1050.6 years before present (the early Northern Song Dynasty), indicating that they are indigenous population, not late Daic migrants from southwestern China
Protective Mechanism of Luteinizing Hormone and Follicle-Stimulating Hormone Against Nicotine-Induced Damage of Mouse Early Folliculogenesis
Previous studies have shown that nicotine could impair the germ cell cyst breakdown and the primordial follicle assembly by autophagy. In this paper, we discovered that luteinizing hormone (LH) and follicle-stimulating hormone (FSH) could counteract the damage caused by nicotine of mouse germ cell cyst breakdown. The neonatal mice were separately intraperitoneally injected with nicotine, nicotine plus LH, nicotine plus FSH, and saline (control) for 4 days. Compared with the nicotine group, the quality of oocytes and the number of follicles were remarkably increased in the nicotine plus LH group or nicotine plus FSH group. LH and FSH could alleviate nicotine-induced oocyte autophagy by different pathways. LH reduced the nicotine-induced autophagy by restoring the phosphorylation level of adenosine 5 '-monophosphate-activated protein kinase alpha-1, while FSH by downregulating the phosphorylation level of Forkhead box class O 1. In addition, in a subsequent study of 6-week mice in different treated groups, we found that LH and FSH supplementation significantly improved normal maturation rates, fertilization rates, and embryo's developmental potential of oocytes in oocytes exposed to nicotine. Taken together, these results suggested that LH and FSH could counteract the damage caused by nicotine and finally ensure normal germ cell cyst breakdown and early embryo development
Calibration of the Timing Performance of GECAM-C
As a new member of the Gravitational wave high-energy Electromagnetic
Counterpart All-sky Monitor (GECAM) after GECAM-A and GECAM-B, GECAM-C
(originally called HEBS), which was launched on board the SATech-01 satellite
on July 27, 2022, aims to monitor and localize X-ray and gamma-ray transients
from 6 keV to 6 MeV. GECAM-C utilizes a similar design to GECAM but
operates in a more complex orbital environment. In this work, we utilize the
secondary particles simultaneously produced by the cosmic-ray events on orbit
and recorded by multiple detectors, to calibrate the relative timing accuracy
between all detectors of GECAM-C. We find the result is 0.1 , which
is the highest time resolution among all GRB detectors ever flown and very
helpful in timing analyses such as minimum variable timescale and spectral
lags, as well as in time delay localization. Besides, we calibrate the absolute
time accuracy using the one-year Crab pulsar data observed by GECAM-C and
Fermi/GBM, as well as GECAM-C and GECAM-B. The results are and , respectively. Finally, we investigate the
spectral lag between the different energy bands of Crab pulsar observed by
GECAM and GBM, which is .Comment: submitte
Ground calibration of Gamma-Ray Detectors of GECAM-C
As a new member of GECAM mission, GECAM-C (also named High Energy Burst
Searcher, HEBS) was launched onboard the SATech-01 satellite on July 27th,
2022, which is capable to monitor gamma-ray transients from 6 keV to 6
MeV. As the main detector, there are 12 gamma-ray detectors (GRDs) equipped for
GECAM-C. In order to verify the GECAM-C GRD detector performance and to
validate the Monte Carlo simulations of detector response, comprehensive
on-ground calibration experiments have been performed using X-ray beam and
radioactive sources, including Energy-Channel relation, energy resolution,
detection efficiency, SiPM voltage-gain relation and the non-uniformity of
positional response. In this paper, the detailed calibration campaigns and data
analysis results for GECAM-C GRDs are presented, demonstrating the excellent
performance of GECAM-C GRD detectors.Comment: third versio
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