Effects of Antibacterial Peptide Extracted from Bacillus subtilis fmbJ on the Growth, Physiological Response and Disease Resistance of Megalobrama amblycephala

The effects of an antibacterial peptide obtained from Bacillus subtilis fmbJ on growth, serum lysozyme complements 3 and 4, total protein content, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total antioxidative capacity, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and disease resistance of Wuchang bream (Megalobrama amblycephala) were examined. Fish were randomly divided into five groups: a control group which was fed a basic diet, and four groups fed the basic diet supplemented with 0.1%, 0.2%, 0.4%, or 0.8% antibacterial peptide. At eight weeks, M. amblycephala fed the diet containing 0.2% antibacterial peptide had higher serum lysozyme activity, complement 3 and 4 contents, and SOD activity than the control fish, but lower serum MDA content and AST activity. Fish fed the 0.4% diet had higher weight gain rate, serum lysozyme activity, complement 4 content, total antioxidative capacity, and total protein than the control, and lower serum ALT activity. Feed conversion ratios of fish fed the 0.2% or 0.4% diets were lower than those of control fish. Artificial infection with Aeromonas hydrophila resulted in 93% cumulative mortality in the control group, and 61-84% in the groups fed the 0.2% or 0.4% diets. The present study suggests that feed supplementation with 0.2-0.4% antibacterial peptides can stimulate immunity, increase resistance to pathogenic infection, and promote growth in M. amblycephala

Stress relaxation analysis facilitates a quantitative approach towards antimicrobial penetration into biofilms

Biofilm-related infections can develop everywhere in the human body and are rarely cleared by the host immune system. Moreover, biofilms are often tolerant to antimicrobials, due to a combination of inherent properties of bacteria in their adhering, biofilm mode of growth and poor physical penetration of antimicrobials through biofilms. Current understanding of biofilm recalcitrance toward antimicrobial penetration is based on qualitative descriptions of biofilms. Here we hypothesize that stress relaxation of biofilms will relate with antimicrobial penetration. Stress relaxation analysis of single-species oral biofilms grown in vitro identified a fast, intermediate and slow response to an induced deformation, corresponding with outflow of water and extracellular polymeric substances, and bacterial re-arrangement, respectively. Penetration of chlorhexidine into these biofilms increased with increasing relative importance of the slow and decreasing importance of the fast relaxation element. Involvement of slow relaxation elements suggests that biofilm structures allowing extensive bacterial re-arrangement after deformation are more open, allowing better antimicrobial penetration. Involvement of fast relaxation elements suggests that water dilutes the antimicrobial upon penetration to an ineffective concentration in deeper layers of the biofilm. Next, we collected biofilms formed in intra-oral collection devices bonded to the buccal surfaces of the maxillary first molars of human volunteers. Ex situ chlorhexidine penetration into two weeks old in vivo formed biofilms followed a similar dependence on the importance of the fast and slow relaxation elements as observed for in vitro formed biofilms. This study demonstrates that biofilm properties can be derived that quantitatively explain antimicrobial penetration into a biofilm

Back to the Soil: Sociological Practice and Chinese Society, 1903–1952.

‘Soil’ in Chinese language is a significant character with rich meanings. It constitutes an essential part of the Chinese character ‘society’. In history, it was applied by Chinese sociologists as a metaphor to describe a non-modern China bounded by agricultural cultures. And ‘soil’ in this usage implies a static and backward Chinese society. ‘Back to the soil’ in this research has a double significance. First, it refers to ‘back to the Chinese society’. Second, it indicates an intention to reverse the approach which places China in the dualistic structure between modem and non-modern, agriculture and industry. This study focuses on the question of how sociological practice happened in the Chinese soil. This research aims to trace the historical practice of Chinese sociology from 1903, when it was first transplanted into the Far East Chinese soil, to 1952 when it was abolished. It argues that sociological interpretations of Chinese society - as the fruit of this soil - were produced by importing and applying sociological knowledge and techniques; but it argues further that the nature, role and function of sociology in this different soil has been significantly re-defined. This research will unpack this historical development by examining the practice of sociology in the Chinese soil. There has recently been a growing awareness of sociology in non-Western or marginal areas. This research will enrich such study by taking Chinese sociology in history as a case. By focusing on the historical practice of sociology in the Chinese soil, this study distinguishes itself from other studies which challenge the Eurocentric sociology by stressing the need for alternative approaches or discourses for non-Western sociology. Furthermore, in the aspect of disciplinary history, unlike the ordinary approach which generates a classified system of canonical theories or theorists, this study explores the approach to the discipline’s past by examining sociological practice. Lastly, in comparative perspective, the Chinese case also implies a point of reference for sociologists in the English world to understand how their Chinese counterparts use sociological methods and techniques in a different context. Using documentary analysis to trace the practice of sociology in history, the data employed for this research include literature and archive material, official statistics, conference notes, field notes, biography and official newspapers. By tracing forms of practice, this research highlights the conceptual formation and transition of society in the Chinese context. It also examines the process and consequence of applying sociological methods (social surveys and community studies) to the Chinese soil for generating empirical and theoretical account of Chinese society. In addition, it reveals the shift of disciplinary identity of Chinese sociology. This research concludes that sociological knowledge imported from foreign countries cannot be reproduced completely by native scholars in the Chinese soil. Adaptations and modifications are required to guarantee the undertaking of sociological techniques. More importantly, the practice of sociology indicates an entanglement and hybridisation between the indigenous soil and the exotic sociology

Back to the Soil: Sociological Practice and Chinese Society, 1903–1952.

‘Soil’ in Chinese language is a significant character with rich meanings. It constitutes an essential part of the Chinese character ‘society’. In history, it was applied by Chinese sociologists as a metaphor to describe a non-modern China bounded by agricultural cultures. And ‘soil’ in this usage implies a static and backward Chinese society. ‘Back to the soil’ in this research has a double significance. First, it refers to ‘back to the Chinese society’. Second, it indicates an intention to reverse the approach which places China in the dualistic structure between modem and non-modern, agriculture and industry. This study focuses on the question of how sociological practice happened in the Chinese soil. This research aims to trace the historical practice of Chinese sociology from 1903, when it was first transplanted into the Far East Chinese soil, to 1952 when it was abolished. It argues that sociological interpretations of Chinese society - as the fruit of this soil - were produced by importing and applying sociological knowledge and techniques; but it argues further that the nature, role and function of sociology in this different soil has been significantly re-defined. This research will unpack this historical development by examining the practice of sociology in the Chinese soil. There has recently been a growing awareness of sociology in non-Western or marginal areas. This research will enrich such study by taking Chinese sociology in history as a case. By focusing on the historical practice of sociology in the Chinese soil, this study distinguishes itself from other studies which challenge the Eurocentric sociology by stressing the need for alternative approaches or discourses for non-Western sociology. Furthermore, in the aspect of disciplinary history, unlike the ordinary approach which generates a classified system of canonical theories or theorists, this study explores the approach to the discipline’s past by examining sociological practice. Lastly, in comparative perspective, the Chinese case also implies a point of reference for sociologists in the English world to understand how their Chinese counterparts use sociological methods and techniques in a different context. Using documentary analysis to trace the practice of sociology in history, the data employed for this research include literature and archive material, official statistics, conference notes, field notes, biography and official newspapers. By tracing forms of practice, this research highlights the conceptual formation and transition of society in the Chinese context. It also examines the process and consequence of applying sociological methods (social surveys and community studies) to the Chinese soil for generating empirical and theoretical account of Chinese society. In addition, it reveals the shift of disciplinary identity of Chinese sociology. This research concludes that sociological knowledge imported from foreign countries cannot be reproduced completely by native scholars in the Chinese soil. Adaptations and modifications are required to guarantee the undertaking of sociological techniques. More importantly, the practice of sociology indicates an entanglement and hybridisation between the indigenous soil and the exotic sociology

Connectedness Between Natural Gas Price and BRICS Exchange Rates: Evidence from Time and Frequency Domains

In this paper, we investigate the connectedness between natural gas and BRICS (Brazil, Russia, India, China, and South Africa)’s exchange rate in terms of time and frequency. This empirical work is based on the approach of connectedness proposed by Diebold and Yilmaz, who provided an effective way of valuing how much variation in one variable is responsible for the value of other variables, and the method proposed by Baruník and Křehlík, who decomposed the results from Diebold and Yilmaz into different frequencies. We also use the rolling-window method to conduct time-varying analysis. The data used in this paper are from 23 August 2010 to 20 June 2019. We find that the natural gas price hardly influences BRICS’s exchange rates, which provides an important practical implication for policymakers, especially in oil-dependent countries

Conditional Dependence between Oil Prices and Exchange Rates in BRICS Countries: An Application of the Copula-GARCH Model

We studied the dependence structure between West Texas Intermediate (WTI) oil prices and the exchange rates of BRICS1 countries, using copula models. We used the Normal, Plackett, rotated-Gumbel, and Student's t copulas to measure the constant dependence, and we captured the dynamic dependence using the Generalized Autoregressive Score with the Student's t copula. We found that negative dependence and significant tail dependence exist in all pairs considered. The Russian Ruble (RUB)-WTI pair has the strongest dependence. Moreover, we treated five exchange rate-oil pairs as portfolios and evaluated the Value at Risk and Expected Shortfall from the time-varying copula models. We found that both reach low values when the oil price falls sharply