Revitalization of Guangzhou Donghaochong River

published_or_final_versionArchitectureMasterMaster of Landscape Architectur

Distinct Aging Effects on Motion Repulsion and Surround Suppression in Humans

Elderly exhibit accumulating deficits in visual motion perception, which is critical for humans to interact with their environment. Previous studies have suggested that aging generally reduces neuronal inhibition in the visual system. Here, we investigated how aging affects the local intra-cortical inhibition using a motion direction discrimination task based on the motion repulsion phenomenon. Motion repulsion refers to the phenomenon by which observers overestimate the perceived angle when two superimposed dot patterns are moving at an acute angle. The misperception has been interpreted as local mutual inhibition between nearby direction-tuned neurons within the same cortical area. We found that elderly exhibited much stronger motion repulsion than young adults. We then compared this effect to how aging affects the global inter-cortical inhibition by adopting the surround suppression paradigm previously used by Betts et al. (2005). We found that elderly showed less change in the discrimination threshold when the size of a high-contrast drifting Gabor was increased, indicating reduced surround suppression compared to young adults. Our results indicate that aging may not always lead to a decrease of neuronal inhibition in the visual system. These distinct effects of aging on inhibitory functions might be one of the reasons that elderly people often exhibit deficits of motion perception in a real-world situation

Structure and Property Investigation of Composite ZnO/SnO2 Nanocrystalline Particles after High-Pressure Treatment

Composite ZnO/SnO2 nanocrystalline particles (ZnO/SnO2) were synthesized by sol-gel method and with treatment of high pressure at 6 GPa. The crystallinity and the particle size of the prepared samples were analyzed by X-ray diffraction (XRD) spectroscopy. The results indicated that all the samples had the good crystallinity, and the particle size of ZnO and ZnO/SnO2 decreased after high-pressure treatment. The infrared (IR) spectra showed that the distance of crystal lattice was shortened after high-pressure treatment, and the size distribution became more uneven after SnO2 doping. With the high-resolution transmission electron microscope (HRTEM), we got some morphology information and evidence to support the IR and XRD analysis results. The results of ultraviolet-visible absorption (UV-Vis) spectra showed that ZnO/SnO2 might improve the photocatalytic property of the samples after high-pressure treatment

Distinct Aging Effects on Motion Repulsion and Surround Suppression in Humans

Elderly exhibit accumulating deficits in visual motion perception, which is critical for humans to interact with their environment. Previous studies have suggested that aging generally reduces neuronal inhibition in the visual system. Here, we investigated how aging affects the local intra-cortical inhibition using a motion direction discrimination task based on the motion repulsion phenomenon. Motion repulsion refers to the phenomenon by which observers overestimate the perceived angle when two superimposed dot patterns are moving at an acute angle. The misperception has been interpreted as local mutual inhibition between nearby direction-tuned neurons within the same cortical area. We found that elderly exhibited much stronger motion repulsion than young adults. We then compared this effect to how aging affects the global inter-cortical inhibition by adopting the surround suppression paradigm previously used by Betts et al. (2005). We found that elderly showed less change in the discrimination threshold when the size of a high-contrast drifting Gabor was increased, indicating reduced surround suppression compared to young adults. Our results indicate that aging may not always lead to a decrease of neuronal inhibition in the visual system. These distinct effects of aging on inhibitory functions might be one of the reasons that elderly people often exhibit deficits of motion perception in a real-world situation.</p

Systematic Review of Contaminants of Emerging Concern (CECs): Distribution, Risks, and Implications for Water Quality and Health

The introduction of contaminants of emerging concern (CECs) into the environment has raised concerns due to the significant risks they pose to both ecosystems and human health. In this sys-tematic review, we investigate research trends on CECs worldwide over the past 10 years, focus-ing on four critical aspects: (i) the identification and distribution of typical CECs across various media, (ii) the sources and environmental behavior of CECs, (iii) the implications of CECs expo-sure on human health, and (iv) risk assessment and control measures for CECs. The review re-veals a comprehensive understanding of the typical types and distribution of CECs in different environmental media, shedding light on their prevalence and potential impact on ecosystems. Furthermore, insights into the sources and behavior of CECs provide crucial information for de-vising effective strategies to mitigate their release into the environment. By examining the health effects of EC exposure, we highlight the importance of considering potential risks to human well-being. This aspect of the review emphasizes the significance of monitoring and managing CECs to safeguard public health. The review also synthesizes the advancements in risk assessment methodologies and control measures for CECs, which are essential for developing comprehensive regulations and guidelines to manage these contaminants effectively. Drawing from the findings, we identify future research directions for CECs in aquatic environments

Social media data as a proxy for hourly fine-scale electric power consumption estimation

Accurate forecasting of electric demand is essential for the operation of modern power system. Inaccurate load forecasting will considerably affect the power grid efficiency. Forecasting the electric demand for a small area, such as a building, has long been a well-known challenge. In this research, we examined the association between geotagged tweets and hourly electric consumption at a fine scale. All available geotagged tweets and electric meter readings were retrieved and spatially aggregated to each building in the study area. Comparing to traditional studies, the usage of geotagged tweets is to reflect human activity dynamics to some degree by considering human beings as sensors, which therefore can be employed at the building level. High correlation is found between the human activity indicator and the power consumption as supported by a correlation coefficient level over 0.8. To the best of our knowledge, rare studies placed an emphasis on hourly electric power consumption using social media data, especially at such a fine scale. This research shows the great potential of using Twitter data as a proxy of human activities to model hourly electric power consumption at the building level. More studies are warranted in the future to further examine the effectiveness of the proposed method in this research

Entrepreneurial talent and economic development in China

In this paper, we argue that the economic miracle of China in the past three decades can be attributed to the reallocation of entrepreneurial talent from the government/state and agricultural sectors to business activities. This change is unprecedented in the past two thousand years of Chinese history. When entrepreneurial talent was moved more to business activities, it created wealth, and the economy boomed. Three dominant groups of entrepreneurs are identified: (1) Peasants-turned entrepreneurs, (2) officials-turned entrepreneurs, and (3) overseas-returned, and engineers-turned, entrepreneurs. They have emerged sequentially, and successively led three decades of economic growth. The success of the Chinese economy arises from a gradual replacement of position-based rights with property-based rights that has triggered this reallocation of entrepreneurial talent. We also argue that when position-based and property-based rights coexist, value-creating and rent-seeking can be complementary. Therefore, one should not be puzzled by the coexistence of rapid economic growth and pervasive corruption in China. In order to improve the efficiency of allocation of entrepreneurial talent and efforts, it is important to further reduce the domain of position-based rights, and build a better-defined and more effectively-protected property rights system.Entrepreneurial talent Economic development Position-based rights Property rights system Strategy China

A Data-Driven Framework for Walkability Measurement with Open Data: A Case Study of Triple Cities, New York

Walking is the most common, environment-friendly, and inexpensive type of physical activity. To perform in-depth walkability analysis, one option is to objectively evaluate different aspects of built environment related to walkability. In this study, we proposed a computational framework for walkability measurement using open data. Three major steps of this framework include the web scrapping of publicly available online data, determining varying weights of variables, and generating a synthetic walkability index. The results suggest three major conclusions. First, the proposed framework provides an explicit mechanism for walkability measurement. Second, the synthetic walkability index from this framework is comparable to Walk Score, and it tends to have a slightly higher sensitivity, especially in highly walkable areas in urban core. Third, this framework was effectively applied in a metropolitan area that contains three small cities that together represent a small, old shrinking region, which extends the topical area in the literature. This framework has the potential to quantify walkability in any city, especially cities with a small population where walkability has rarely been studied, or those having no quantification indicator. For such areas, researchers can calculate the synthetic walkability index based on this framework, to assist urban planners, community leaders, health officials, and policymakers in their practices to improve the walking environment of their communities

Bioactivation and Regioselectivity of Pig Cytochrome P450 3A29 towards Aflatoxin B1

Due to unavoidable contaminations in feedstuff, pigs are easily exposed to aflatoxin B1 (AFB1) and suffer from poisoning, thus the poisoned products potentially affect human health. Heretofore, the metabolic process of AFB1 in pigs remains to be clarified, especially the principal cytochrome P450 oxidases responsible for its activation. In this study, we cloned CYP3A29 from pig liver and expressed it in Escherichia coli, and its activity has been confirmed with the typical P450 CO-reduced spectral characteristic and nifedipine-oxidizing activity. The reconstituted membrane incubation proved that the recombinant CYP3A29 was able to oxidize AFB1 to form AFB1-exo-8,9-epoxide in vitro. The structural basis for the regioselective epoxidation of AFB1 by CYP3A29 was further addressed. The T309A mutation significantly decreased the production of AFBO, whereas F304A exhibited an enhanced activation towards AFB1. In agreement with the mutagenesis study, the molecular docking simulation suggested that Thr309 played a significant role in stabilization of AFB1 binding in the active center through a hydrogen bond. In addition, the bulk phenyl group of Phe304 potentially imposed steric hindrance on the binding of AFB1. Our study demonstrates the bioactivation of pig CYP3A29 towards AFB1 in vitro, and provides the insight for understanding regioselectivity of CYP3A29 to AFB1

Beryllium-7 measurements of wind erosion on sloping fields in the wind-water erosion crisscross region on the Chinese Loess Plateau

Soil erosion is complex in the wind-water erosion crisscross region of the Chinese Loess Plateau, as interleaving of wind and water erosion occurs on both temporal and spatial scales. It is difficult to distinguish wind erosion from the total erosion in previous studies due to the untraceable of aeolian particles and the limitation of feasible methods and techniques. This study used beryllium-7 measurements to study wind erosion in the wind-water erosion crisscross region on the Chinese Loess Plateau arms to delineate wind erosion distribution, to analyze its implication to erosive winds and surface microrelief, and to determine correlations between erosion rates and slope gradients. Results obtained using beryllium-7measurements based on observation plots were verified with saltating particle collection method, and were also verified on a field scale. Results indicated that the effective resultant erosion wind was from northward, which was proved by the eight-directional distributed saltating particles. The microrelief of the ground surface contributed to the formation of high or low erosion centers. Wind erosion rates increased with a linear (R-2 >= 0.95) or exponential (R-2 >= 0.83) fitting increase in the slope gradients as reported in previous studies. Compared to wind erosion on field scale, both the plots and fields exhibited similar distribution patterns in wind erosion isolines. We also determined that the wind erosion rate for two fields estimated, based on equations developed from plot scale was acceptable. This study validates the feasibility of beryllium-7 measurements for soil-wind erosion field experiments and the potential to expand this approach to real field conditions. (C) 2017 Elsevier B.V. All rights reserved