2,130 research outputs found
The effects of theophylline on the in vitro respiratory response to hypoxia
The isolated transverse brainstem slice preparation of neonatal mice is employed to investigate the function of theophylline, a competitive nonselective phophodiesterase inhibitor and adenosine receptor antagonist, on the hypoxic ventilatory response. Brainstem slices are isolated from neonatal mice (4-8 days old) and superfused with artificial cerebrospinal fluid (aCSF), equilibrated with a hyperoxic gas mixture (95% O2, 5% CO2) as a control, and anoxic mixture (0% O2, 5% CO2, 95% N2) to create severe hypoxia at the tissue level. Using suction electrodes, extracellular population activities of respiratory neurons is recorded from brainstem slices in the region of the pre-Bötzinger Complex (preBötC), a site of inspiratory rhythm generation. One goal of this study is to detect if the theophylline increases in vitro respiratory activity under control oxygen conditions. Another goal is to determine the extent to which theophylline reverses the respiratory depression during severe hypoxia
Should China Provide Intellectual Property Protection for Genetically Modified Animals?
The advent of recombinant genetic engineering techniques has revolutionized biotechnology. The biomedicine and biotechnology industries have extensively employed these techniques to improve the quality of agricultural crops and livestock and to create genetically modified organisms ( GMOs ) in order to produce drugs. Since as much as twenty-five percent of the world\u27s intellectual property-related trade involves biotechnology, many countries have realized the importance of providing intellectual property protection for biotechnological technologies, including GMOs. In the past decade, China\u27s booming economy has helped make its biotechnological market the fastest growing market in the world. To stimulate innovation and attract private investment in its biotechnology industry, China has rapidly transformed its intellectual property laws to conform with western models in the last two decades. However, plants and animals are not patentable in China. While plant varieties enjoy sui generis system protection, animal varieties are not protected by any law. This poses a serious problem for biotechnology firms that have heavily invested in the research and development of genetically modified animals. This article focuses on whether China should provide intellectual property protection for new animal varieties, including genetically modified animals. Section II offers a brief introduction to the development of recombinant genetic engineering techniques. Section III discusses the benefits and risks of GMOs. The ethical issues of animal patenting are discussed in section IV. Sections V and VI present an overview of international and China\u27s intellectual property protection for GMOs, respectively. Section VII concludes with a discussion of why and how China should provide intellectual property protection for genetically engineered animals
Phase regeneration of QPSK signals based on Kerr soliton combs in a highly nonlinear optical fiber
We demonstrate an all-optical phase regeneration technique based on Kerr
soliton combs, which can realize degraded quaternary phase shift keying (QPSK)
signal regeneration through phase-sensitive amplification. A Kerr soliton comb
is generated at the receiver side of optical communication systems based on a
carrier recovery scheme and is used as coherent dual pumps to achieve phase
regeneration. Our study will enhance the relay and reception performance of
all-optical communication systems.Comment: 8pages;5figure
A New Approach for Characterizing the Intermediate Feature of α-Chymotrypsin Refolding by Hydrophobic Interaction Chromatography
A new approach for characterizing the intermediate of urea-denatured α-chymotrypsin (α-Chy) by hydrophobic interaction chromatography (HIC) is presented. The contact surface region (Z, S), affinity (logI), and the character of interaction force (j) of the α-Chy to the stationary phase of HIC (STHIC) between the intermediate (M) and native (N) states were found to be quite different as urea concentration (Curea) changes. With the changes in Curea, a linear relationship between logI and Z was found to exist only for its N state, not for M state, indicating the interaction force between α-Chy in N state to the STHIC to be non-selective, but selective one for its M state. Also, the measured magnitude of both logI and Z in M state is only a fifth of that in N state. All three parameters were employed to distinguish protein in the N state from that in the M state. It would be expected that this result could be employed to distinguish any kind of non-functional protein having correct three-, or four-dimensional molecular structure from their stable M state of any kinds of proteins, and/or other proteins in proteome investigation, separation process of protein, and intensively understanding the intrinsic rule of protein folding in molecular biology
Correlation of Road Network Structure and Urban Mobility Intensity: An Exploratory Study Using Geo-Tagged Tweets
Urban planners have been long interested in understanding how urban structure and activities are mutually influenced. Human mobility and economic activities naturally drive the formation of road network structure and the accessibility of the latter shapes the patterns of movement flow across urban space. In this paper, we perform an exploratory study on the relationship between the street network structure and the intensity of human movement in urban areas. We focus on two cities and we utilize a dataset of geo-tagged tweets that can form a proxy to urban mobility and the corresponding street networks as obtained from OpenStreetMap. We apply three network centrality measures, including closeness, betweenness and straightness centrality, calculated at a global or local scale, as well as under mixed or individual transportation mode (e.g., driving, biking and walking) with its directional accessibility, to uncover the structural properties of urban street networks. We further design an urban area transition network and apply PageRank to capture the intensity of human mobility. Our correlation analysis indicates different centrality metrics have different levels of correlation with the intensity of human movement. The closeness centrality consistently shows the highest correlation (with a coefficient around ) with human movement intensity when calculated at a global scale, while straightness centrality often shows no correlation at the global scale or weaker correlation at the local scale. The correlation levels further depend on the type of directional accessibility and of various types of transportation modes. Hence, the directionality and transportation mode, largely ignored in the analysis of road networks, are crucial. Furthermore, the strength of the correlation varies in the two cities examined, indicating potential differences in urban spatial structure and human mobility patterns
ERA: Expert Retrieval and Assembly for Early Action Prediction
Early action prediction aims to successfully predict the class label of an
action before it is completely performed. This is a challenging task because
the beginning stages of different actions can be very similar, with only minor
subtle differences for discrimination. In this paper, we propose a novel Expert
Retrieval and Assembly (ERA) module that retrieves and assembles a set of
experts most specialized at using discriminative subtle differences, to
distinguish an input sample from other highly similar samples. To encourage our
model to effectively use subtle differences for early action prediction, we
push experts to discriminate exclusively between samples that are highly
similar, forcing these experts to learn to use subtle differences that exist
between those samples. Additionally, we design an effective Expert Learning
Rate Optimization method that balances the experts' optimization and leads to
better performance. We evaluate our ERA module on four public action datasets
and achieve state-of-the-art performance.Comment: Accepted to ECCV 202
DiffPose: Toward More Reliable 3D Pose Estimation
Monocular 3D human pose estimation is quite challenging due to the inherent
ambiguity and occlusion, which often lead to high uncertainty and
indeterminacy. On the other hand, diffusion models have recently emerged as an
effective tool for generating high-quality images from noise. Inspired by their
capability, we explore a novel pose estimation framework (DiffPose) that
formulates 3D pose estimation as a reverse diffusion process. We incorporate
novel designs into our DiffPose to facilitate the diffusion process for 3D pose
estimation: a pose-specific initialization of pose uncertainty distributions, a
Gaussian Mixture Model-based forward diffusion process, and a
context-conditioned reverse diffusion process. Our proposed DiffPose
significantly outperforms existing methods on the widely used pose estimation
benchmarks Human3.6M and MPI-INF-3DHP. Project page:
https://gongjia0208.github.io/Diffpose/.Comment: Accepted to CVPR 202
Research on financing ecology and financing efficiency of strategic emerging industries in China
After integrating external ecological and endogenous factors of the development of the industry, the paper builds a financing ecology index system, and analyses the financing ecology of strategic emerging industries in recent years. Then the paper further analyses the influence of external and internal financing ecology on financing efficiency. The results show that the financing ecology of the strategic emerging industries, external financing ecology in particular, is in the continuous improvement. The financing efficiency is significantly positively correlated with the macro-economy level and the internal financing ecology, and significantly negatively correlated with the role of government. There is a positive but non-significant correlation between financial development and financing efficiency, meanwhile a negative and non-significant correlation between credit environment and financing efficiency. The internal and external financing ecology can be replaced to some extent. Therefore, the strategic emerging industries should give full consideration to the synergistic optimization of the endogenous factors and external financing ecology so as to improve the financing efficiency
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