Extensive Mode Research Articles

Effect of smart city construction on an urban transition to a low-carbon economy: evidence from China.

China is currently in a new era of an urban transition to a low-carbon economy and digital economic development. Smart cities, as an advanced form of information-based urban development, may be the key to the urban transition to low-carbon emissions. This paper examined the effect of smart city construction (SCC) on urban low-carbon transitions and its transmission mechanisms in China from the dual perspectives of reducing urban total carbon emissions (TCE) and improving urban total-factor carbon emission efficiency (TFCEE). Utilizing a multi-period difference in differences (DID) method, this study was conducted based on panel data of 245 Chinese prefecture-level cities from 2003 to 2021. The results demonstrated that SCC both reduced TCE and enhanced TFCEE. The effects of SCC were stronger in cities with more stringent environmental regulations. SCC achieved the dual effect of reducing TCE and enhancing urban TFCEE by promoting green technological progress and a low-carbon transformation of city residents' lifestyles. Moreover, optimization of the industrial structure was also a transmission mechanism for SCC to improve TFCEE. These conclusions provide an empirical basis for the SCC to empower low-carbon transitions of cities and help countries in different regions to transform the extensive urban development mode and promote urban low-carbon economic development.

Carbon emission efficiency of China’s construction industry based on super-efficiency SBM and Tobit model

Global warming is one of the key issues attracting international concern. The carbon dioxide emission produced by energy combustion is the main cause of the greenhouse effect, and reducing carbon emissions is considered the most effective way to deal with the greenhouse effect. The extensive production mode characterized by high energy consumption, high emission, and low efficiency in China’s construction industry intensifies the contradiction between economic development and resources and the environment, and the growth under this mode is at the expense of consuming a lot of resources and energy. The improvement of carbon emission efficiency is an effective means of achieving the goal of economic growth and carbon emission reduction simultaneously, making it necessary to accurately measure the carbon emission efficiency of the construction industry in each province, determine the influencing factors, and formulate reasonable emission reduction policies for this industry. In this study, an input-output index system of carbon emission efficiency of China’s construction industry was constructed, the carbon emission efficiency of the construction industry in each province was evaluated using the super-efficiency SBM model, and the factors affecting the carbon emission efficiency of this industry were analyzed via the Tobit model. The results showed that the average value of carbon emission efficiency of the construction industry generally showed a rising trend in a fluctuating way during the study period. From 2014 to 2022, the average carbon emission efficiency of the national construction industry presented an upward trend, from 1.122 in 2014 to 1.148 in 2022; the regional economic level (p= 0.020 < 0.05) and human capital level (p= 0.000 < 0.01) exerted obvious promoting effects on the carbon emission efficiency of China’s construction industry, while the urbanization development (p= 0.049 < 0.05) generated evident negative effects on carbon emission efficiency of this industry. The research results have important reference values for making cross-provincial emission reduction plans for the construction industry, promoting its carbon emission efficiency, and driving the research and development of green building materials and clean energy.

The Impact of Green Finance on Corporate Carbon Productivity

The Impact of Green Finance on Corporate Carbon Productivity

Research on the coupling and coordinated development of Guangxi's tourism industry, new urbanization and environmental health system in the post-epidemic era.

As one of China's sunrise industries, tourism has always been the engine to promote the development of the national economy, and in 2018, the annual income of China's tourism industry exceeded 5 trillion yuan unprecedentedly. In recent years, the traditional extensive production mode has inevitably brought about problems such as environmental pollution and public health threats, while helping the development of new urbanization, thus triggering a series of challenges in the environmental health system. The tourism industry, new urbanization, and environmental health system three cooperate and promote each other, the coordinated development between them for economic growth, new urbanization development, environmental protection, and public health play a vital role, in the post-epidemic era is a special period of historical opportunities, the public's focus from the original sacrifice of environmental health in exchange for economic growth model began to green, low-carbon sustainable development mode, Guangxi Zhuang Autonomous Region as a tourism resource endowment rich region, It is of positive significance to explore the coupling degree and coordination between the tourism industry, new urbanization and environmental health system, and put forward targeted practical enlightenment, which is of positive significance for promoting the sustainable development of tourism industry. Taking Guangxi Zhuang Autonomous Region as a case study, this paper constructs three comprehensive evaluation index systems of the tourism industry, new urbanization and environmental health system, and analyzes and compares the weights of various indicators in the three fields of tourism economy, new urbanization and environmental health system in Guangxi by using the entropy weight TOPSIS method. The coupling coordination model was used to measure the coupling degree and coordination degree of the tourism industry, new urbanization and environmental health system construction in Guangxi Zhuang Autonomous Region from 2009 to 2021. The empirical results show that the weights of various indicators change with the development of the social economy. The comprehensive efficacy index of Guangxi's tourism industry has increased year by year for 11 consecutive years; At the end of the evaluation period, after the outbreak of the new crown epidemic, the evaluation index of the tourism industry, new urbanization and environmental health system all showed a downward trend to varying degrees. Before the pandemic, the coupling coordination type of the three subsystems generally experienced a transformation of "moderate dissonance-reluctant coordination-primary coordination-intermediate coordination," but the overall development level was still poor. After the outbreak of the new crown epidemic, the coupling and coordination between the three has been reduced to a state of poor coordination. Because of the above research conclusions, this study proposes to make full use of the important time node of the post-epidemic era and proposes to actively promote the development of the tourism industry, promote the upgrading of the industrial structure, use digital empowerment of the economic form, optimize the environmental health system and other targeted countermeasures to keep the coupling degree and coordination between the three within a reasonable range. This ensures the sustainable development of social systems in the region. This study has made some contributions to the development of high-quality tourism and a healthy environment. First of all, it enriches the content of the environmental health system. This study takes the ecological environment and atmospheric environment in the environmental health system as the entry point and adds the index content of the environmental health evaluation system, which provides a certain supplement for the relevant research on the environmental health system strength. Secondly, the relationship between the tourism industry, new urbanization and environmental health is analyzed and into a unified theoretical framework. This study takes the Guangxi Zhuang Autonomous Region, which is rich in tourism resources, as a case study site, and innovatively explores the coupling and coordination relationship among the tourism industry, new urbanization and environmental health system in the case site. Finally, it provides targeted countermeasures for the sustainable development path of the three systems of tourism industry, new urbanization and environmental health in the case site in the future. It is of positive practical significance to compare the coupling and coordination degree between the three, realize the coordinated, orderly, and healthy development of the three in the region, and provide operational suggestions for the upgrading of the tourism industry structure, the benign development of new urbanization, and the formulation of environmental health system policies.

Research on Cost Management of Logistics Enterprises from the Perspective of Value Chain

In recent years, the rise of online platform transactions has led to the rapid development of the logistics industry. On the other hand, the extensive management mode of China's logistics industry can be changed to precise management, which has more advantages in international competition. This paper adopts a combination of literature research and case analysis to analyze how SN Holdings can use value chain cost management to optimize and allocate internal and external resources in the process of cost management, reduce energy consumption and improve resource efficiency, so as to maintain the long-term competitive advantage of the enterprise.

Shale 3D Flow and Interaction With Basement Faults in the Niger Delta Deep‐Water Fold and Thrust Belt

AbstractBased on a large 3D seismic data set in the deep‐water domain of the Niger Delta, this study challenges previous interpretations involving the occurrence of multiple detachments and extensive thrust flats, illustrating timing and mode of shales flow at the toe of the gravity system. Five units of syn‐kinematic sediments, reaching a maximum thickness of ∼800 m, accumulated in the tectonically subsiding synclines during fold amplification between ∼9.5 and ∼1.4 Ma. The volumes of syn‐kinematic units roughly balance those of the shales accumulated in the thickened cores of WNW trending anticlines. This feature is consistent with folding resulting from buckling controlled by the competence contrast between isopach Cenozoic units and underlying overpressured shales of the Akata Formation. A dense network of NE‐SW striking oblique extensional faults offsets a prominent anticline characterized by a NE‐SW trend (which is almost perpendicular to the regional fold trend). These faults form a narrow, continuous deformation zone extending for tens of kilometers along and beyond the length of the anticline. The faults, rooting within the shales of the Akata Formation, formed since ∼5 Ma and deform the seabed. Displacement distribution suggests mechanical interaction between isolated fault segments within the deformation zone. The latter is interpreted as the shallow expression of a deep‐seated fault zone inherited from the segmented passive margin and marked by gravity and magnetic data. Our results, providing a comprehensive picture of active deformation features and their relationships with deep‐seated faults, shed new light into the modes of interaction between gravity systems and underlying basement structures.

The Influence of Social Norms and Environmental Regulations on Rural Households’ Pesticide Packaging Waste Disposal Behavior

The agricultural ecological environment provides an important resource guarantee for social development. The extensive management mode of agriculture in China has not fundamentally changed; the contradiction between production and governance is still prominent, and the management of agricultural surface pollution has a long way to go. Based on the data from 572 rural households in Jiangxi province, this paper uses the Ordered Logit, 2SLS, and the moderation effect model to analyze the mechanism between social norms (SNs) and rural households’ (RHs) disposal of pesticide packaging waste (PPW) and to test the moderation effect of environmental regulation (ER) in the influence path of SN to RHs’ disposal of PPW. The results show that (1) descriptive norms and directive norms promote RHs not littering PPW; the probability of RHs not littering PPW increases by 4.0% for each unit decrease in descriptive norms, and the probability of RHs not littering PPW increases by 12.1% when there are directive norms, but the directive norms are more significant than the descriptive norms. Consistent conclusions were obtained after the robustness test and endogeneity treatment. (2) Reputational incentives strengthen the promotional effect of directive norms on RHs’ behavior of not littering PPW; punitive regulations hinder the promotional effect of descriptive norms on RHs’ behavior of not littering PPW. Based on the findings of the study, the following policy recommendations are put forward: Actively cultivate SNs and give full play to their role in promoting RHs’ choice of the disposal behavior of PPW; improve the role of ER in regulating RHs’ choice of the disposal behavior of PPW; guide the ER and SNs to work in coordination.

Energy‐related‐CO2 emissions in China's electricity and heating industry: A dual perspective of the economic “new normal”

AbstractAfter China's economy entered a “new normal,” their economic development model shifted from an energy‐intensive to an energy‐saving, given that China's electricity and heating industry accounts for about half of the country's energy consumption and carbon emissions. Based on the sample data from 2005 to 2020, this paper adopts the energy consumption method and the extended index decomposition model to explore carbon emissions of the electricity and heating industry in the early and late period of the economic new normal. The results show that: (1) carbon emissions from the electricity and heating industry showed a growing direction in the economic new normal period. However, compared with the early period of economic new normal, the increasing speed of carbon emissions from the electricity and heating industry slowed down significantly in the late period. This point also directly reflects that the extensive development mode of energy utilization has been alleviated after the electricity and heating industry entered the economic new normal. (2) Compared with the early period, the energy structure effect on the emission reduction was enhanced after entering the economic new normal. Meanwhile, the investment efficiency effect has changed from promoting to inhibiting. (3) Compared with the early period, the promotion impact of the investment scale effect on carbon emissions in the electricity and heating industry has no significant change after entering the economic new normal. Nevertheless, it is noteworthy that the emission reduction impact of the energy intensity effect is weak. This paper not only provides empirical evidence for evaluating the emission reduction effects of the Chinese electricity and heating industry before and after the economic new normal but also shares policy insights for precise emission reduction in the electricity and heating industry in the later stage of the economic new normal.

Impacts of digital government on regional eco-innovation: Moderating role of dual environmental regulations

Regional eco-innovation can change the extensive development mode and promote the sustainable development of the economy and society. In the background of digital government construction, the external environment of regional eco-innovation has changed. In this study, the panel data of 125 prefecture-level cities in China from 2013 to 2020 are used to construct a fixed-effect model for empirical analysis by sorting out the relationships among digital government, regional eco-innovation, and dual environmental regulation. The following conclusions are drawn: First, digital government mainly promotes the improvement of regional eco-innovation through digital society and digital citizenship. Second, formal and informal environmental regulations have remarkable positive effects on regional eco-innovation. Third, informal environmental regulation has a positive moderating effect on digital administration and regional eco-innovation and a positive moderating effect on digital citizenship and regional eco-innovation. Fourth, formal environmental regulation cannot moderate the relationship between digital government and regional eco-innovation. This study can give priority to promoting the digital government to serve and play a role in ecological governance and environmental information disclosure, so as to provide policy opinions for the government when issuing documents supporting the improvement of regional eco-innovation, and promote the realization of a more reasonable allocation of innovation resources.

Bitcoin trading, economic growth, energy use, and CO2 emissions: An advanced panel study of emerging market economies

Carbon dioxide emissions pose a severe threat to the global eco-system and human health, yet at the same time the exponential growth of Bitcoin trading, unsustainable mode of current economic development, and the low efficient energy usage have become burgeoning issues in emerging market economies. By applying advanced econometric techniques, this research empirically tests the dynamic impacts of Bitcoin trading, economic growth, and energy use on CO2 emissions in the top 20 Bitcoin-trading emerging market economies from 2013 to 2020, highlighting results on the existence of cross-section dependence, slope heterogeneity, and unit roots in the panel data. Moreover, Bitcoin trading, economic growth, and energy use have a significantly positive effect on CO2 emissions from a long-term perspective. Findings further show that CO2 emissions have a bi-causal correlation with all three determinants. Relevant implications are offered as follows. For academic researchers, cross-section dependence and slope heterogeneity are important considerations, and ignoring them would lead to significantly biased inferences. Emerging market governments should introduce eco-friendly technology for Bitcoin trading, modify the present extensive mode of economic growth, and guard against unsustainable energy consumption.

The Effects of Ripening Stage and Mode of Culture of Chemlali, Arbequina, and Koroneiki on the Capacities of Oils to Scavenge ABTS Free Radicals

This paper focuses on evaluating the antioxidant power of olive oil against the cation radical ABTS•+ according to cultivars (Chemlali, Arbequina and Koroneiki), culture modes (extensive and intensive), ripening stages (November and December corresponding stages), and study year (2017 and 2018). Radical percentage inhibition (PI), Trolox equivalent antioxidant capacity (TEAC), inhibitory concentration required to scavenge 50% of radicals (IC50), and principal component analysis (PCA) were determined. The oil of the Tunisian main cultivar, Chemlali, cultivated in extensive mode, has the best scavenging power with the lowest IC50 values of 9.3, 10.8, 9.65 and 10.4 µg/ml respectively in all the ripening stages. Also, at the lowest tested concentration of 20 µg/ml, this oil has the highest TEAC values, respectively 2.28 and 2.20 in November of 2017 and 2018. For the introduced cultivars, Koroneiki presents better performance than Arbequina, in intensive mode, with IC50 ranged from 9.6 to 13.8 against 12.40 to 22.35 for Arbequina. Furthermore, the principal component analysis proves that the oils of Chemlali in extensive mode and Koroneiki in intensive mode have the best scavenging capacity of ABTS•+. This study proves that the extensive mode is the best culture mode and the ripening stage of November is the best stage in order to get oils with the highest antioxidant capacity.

Local environmental legislation and employment growth: evidence from Chinese manufacturing firms.

In China, there exists a huge debate for a long time on whether a double dividend, reducing pollution emissions and boosting employment, can be achieved by intensifying environmental regulations. In this paper, we use two data sets on provincial environmental legislation and Chinese manufacturing firms during 1998-2013, to estimate the impact of provincial environmental legislation on the firms' employment growth with a difference-in-difference (DID) model. Results showed that (1) after the implementation of environmental legislation, the employment growth of regulated manufacturing firms decreases significantly by 3.07%, and this result is robust to alternative tests. (2) Local environmental legislation reduces employment growth mainly via the influencing mechanism of the firm's entry and exit, export, and innovation. (3) The local environmental legislation has heterogeneous impacts on employment growth in different industries and different regions, and the estimated effect is more obvious in high-pollution industries and areas with strong enforcement. (4) Environmental legislation significantly improves job destruction and reduces job creation, resulting in a - 3.86% job net increase. Due to the long-term implementation of extensive economic growth mode, China's ecological environment has been deteriorating since the 1990s, and environmental pollution has attracted more and more social attention. Until 2013, the Communist Party of China put forward 'ecological civilization', and building a beautiful new China with harmonious coexistence between man and nature has become an important development strategy. Meanwhile, starting from the implementation of the Two-Control-Zone policy in 1998, China has implemented numerous environmental policies in just ten years. These environmental policies have greatly improved the quality of China's ecological environment, but their economic effects have been controversial. Given the special historical period, this paper helps assess the impact of Chinese environmental policies on employment and provides a more objective policy evaluation and implications for improving existing laws and regulations to achieve higher social welfare. To achieve this goal of balancing the improvement of the ecological environment and high employment level, environmental policies firstly should be flexible to ensure that the environmental standards follow the firm's characteristics and regional characteristics to avoid "one size fits all". Particularly, for regions with poor economic development or having a single industrial structure, the implementation cycle of the environmental policies should be extended to ensure that they have enough time to achieve industrial restructuring and complete the environmental protection goals. Secondly, we find that environmental legislation hurts employment growth by limiting export decisions, so the government should use multiple channels to stabilize export when implementing environmental legislation. Thirdly, technological R&D and innovation play an important role in the effect of environmental legislation on firms' employment growth. Therefore, the government should provide a more flexible environment for firms' R&D and innovation with appropriate fiscal policies and technical support.

Typology of rabbit rearing systems in tropical areas: A case of Benin (West Africa)

The breeding of rabbits in tropical areas is confronted with enormous difficulties related to feeding and health, which limit the expansion and viability of these farms. The objective of this study is to carry out a typology of rabbit farms in tropical conditions to characterize the structure and function of this rearing in order to better understand their production results. A sample of 600 rabbit farms located throughout Benin was selected. The typology was carried out using multiple correspondence analysis (MCA) followed by Hierarchical Cluster Analysis (HCA) according to the Ward's aggregation algorithm and Euclidean distance, which identified five typological groups. Group 1 covered 45.7% of the farms and included small-scale production (fewer than 20 does) by professional breeders using traditional parasite control methods. Group 2 covered 3.3% of the rearing and includes a larger number of semi-extensive farms using self-produced feed. Group 3 (14.7%) was characterized by farms with fewer than 20 does that were semi-extensive and used more phytotherapy. In Group 4 (9.7% of the farms), the extensive mode was the most used, with veterinary medicine being the most used. Group 5 concentrated 26.7% of the farms and was marked by semi-extensive breeding. These farms did not record any cases of parasitosis. The typology carried out allowed a better understanding of the operating modes of these farms, their problems and the main limiting factors.

Classification and Development Potential Evaluation of Urban Metro Station Areas Based on Extended Node-Place Model-- A case study of Nanjing Metro Line 1

In the process of changing from the extensive mode to the compact mode of the urban space development in China, metro has solved the problem of high-capacity and rapid transportation in cities. The planning of metro stations needs to be investigated in the context of station types in the process of the urban development. In the research, combined with the development examples of stations and surrounding areas along Nanjing Subway Line 1, the factors such as the classification of station types, the current development potential assessment and so on were investigated based on the extended "node-place" model. And then the scientific and reasonable optimization and adjustment strategies for stations and surrounding areas were proposed, which provides reference for the subsequent planning strategies and development and construction of metro stations and surrounding areas.

Production Efficiency of Raw Milk and Its Determinants: Application of Combining Data Envelopment Analysis and Stochastic Frontier Analysis

China’s raw milk production is confronted with problems such as high production costs, stringent environmental constraints, weak industrial interest linkages, etc. The extensive and inefficient operation mode seriously restricts the further development of China’s dairy industry. How to increase the production efficiency of raw milk and realize the transition from “a country with high milk production” to “a country with high-efficiency milk production” has become the key to further developing China’s dairy industry. In order to explore the upgrading path of the raw milk industry in China, this study used the DEA-Malmquist model to estimate the production efficiency of raw milk in China and analyze its spatial and temporal distribution characteristics based on raw milk production input and output data at four scales (i.e., free-range, small-scale, medium-scale, and large-scale) from 2004 to 2020. It then adopted the SFA model to explore the relationship between raw milk input and output factors and the driving factors of production efficiency. Finally, robustness was discussed according to the existing research differences. The study draws several valuable conclusions. First, the production efficiency of raw milk in China from 2004 to 2020 fluctuated upward and showed specific regular regional distribution characteristics, but the spatial–temporal differences were minor. Second, raw milk production efficiency is significantly influenced by various factors, including the proportion of concentrate to roughage consumption, medical and epidemic prevention investment, the price of raw milk, the wage level, and fixed assets. Third, the spatial–temporal distribution and driving factors of raw milk production efficiency are less robust, so efficiency analysis and improvement measures should fully consider analytical methods, scale heterogeneity, indicator systems, and temporal heterogeneity.

Research on Coal Mine Building Compliance Inspection System Based on Accident Causation and BIM in China

Coal mine construction projects have high risks, and non-compliant designs generated in the design stage will have adverse effects on subsequent construction and production stages. Therefore, it is of great importance to conduct effective preconstruction compliance inspections on coal mine construction designs. To make the compliance check of coal mine building design more rapid and effective, and to reduce the risks arising from the design phase, this study built a compliance inspection system for coal mine building design from the causes of coal mine accidents, using the Word2Vec word similarity calculation method and BIM platform secondary development technology. The system was tested and was found to be able to detect a 92.82% non-compliant component rate where the correct inspection rate was 97.68%. In addition, the inspection time for a single component was only 0.23 s. The construction of the compliance inspection system based on accident causes has changed the extensive inspection mode in the traditional manual model inspection, and the inspection no longer depends on the experience of inspectors, thus improving the efficiency and accuracy of coal mine building model inspection. The inspection focuses on the building elements with high risks, which achieves the purpose of risk control in the design stage.

Spectrally-Pure Integrated Telecom-Band Photon Sources in Silicon

We demonstrate theoretically the direct (filter-free) generation of spectrally uncorrelated photon pairs, and consequently high-purity heralded single photons at telecommunication wavelengths, in SOI (silicon-on-insulator) nanowaveguides via spontaneous four-wave mixing (SFWM). The inherent strong waveguide dispersion in such high-index contrast structures is employed for discrete-band phase-matching in order to suppress the pair spectral correlations, and to produce photons in the fundamental spatial mode for easy in-out coupling to single-mode optical fibers. Additionally, by optimizing the source parameters like waveguide length, dispersion and pump bandwidth, the group-velocity of generated photons is also engineered to further eliminate spectral correlations. Extensive numerical mode simulations for various waveguide widths are used to design intrinsically pure photon sources via joint spectral amplitude (JSA) engineering. Purity <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$&gt;$</tex-math></inline-formula> 95% is shown to be achievable in a silica-clad SOI waveguide with a cross-section 220 × 600 nm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula> for typical values of length and pump bandwidth. The wavelength of these heralded single photons can be tuned in the range of 1266–1363 nm ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sim$</tex-math></inline-formula> O-band) by varying the pump wavelength. Considering the high accuracy provided by silicon nanofabrication techniques, the feasibility of generating single photons across the wavelength range 1333–1425 nm (E-band) and 1437–1510 nm (S-band) for slightly different waveguide widths (625 nm & 650 nm) is also demonstrated. These filter-free integrated photon sources could be important for large-scale linear optical quantum computation (LOQC) and long-distance fiber-optic quantum key distribution (QKD) networks.

How do economic growth targets affect energy consumption? The role of Chinese-style fiscal decentralization

The strategic formulation of economic growth targets (TAR) plays an essential role in economic development, but it may also affect energy consumption. Using China’s provincial data from 2000 to 2018, this study empirically analyzes the impact of TAR on energy consumption. The results show that the local TAR significantly increases energy consumption, and this effect is significant in the eastern and midwestern regions, but there are differences in different development stages. Meanwhile, the unreasonable industrial structure and extensive urbanization mode are the important influencing mechanisms that TAR affects energy consumption. More importantly, Chinese-style fiscal decentralization is an important factor in explaining the relationship between TAR and energy consumption. As the degree of fiscal decentralization increases, the promotion effect of TAR on energy consumption becomes more obvious. In conclusion, the theoretical and empirical evidence of this study indicates that deepening the reform of government target-based management system is helpful to stimulate the motivation of local governments in energy conservation.

The Effects of Ripening Stage and Mode of Culture of Chemlali, Arbequina and Koroneiki on the Capacities of Oils to Scavenge ABTS Free Radicals

The aim of this study is to evaluate the antioxidant power of the olive oil against the cation radical ABTS•+, according to cultivars: Chemlali, Arbequina and Koroneiki; culture modes: extensive and intensive; ripening stages: November and December corresponding stages and study year: 2017 and 2018. Radical percentage inhibition (PI), Trolox equivalent antioxidant capacity (TEAC), inhibitory concentration required to scavenge 50% of radicals (IC50) and principal component analysis (ACP) were determined. The oil of the Tunisian main cultivar Chemlali, cultivated in extensive mode, has the best scavenging power with the lowest IC50 values of 9.3, 10.8, 9.65 and 10.4 µg/ml respectively in all the ripening stages. Also, at the lowest tested concentration of 20 µg/ml, this oil has the highest TEAC values, respectively 2.28 and 2.20 in November of 2017 and 2018. For the introduced cultivars, Koroneiki presents better performance than Arbequina, in intensive mode, with IC50 ranged from 9.6 to 13.8 against 12.40 to 22.35 for Arbequina. Furthermore, the principal component analysis proves that the oils of Chemlali in extensive mode and Koroneiki in intensive have the best scavenging capacity of ABTS•+. This study proves that the extensive mode is the best culture mode and the ripening stage of November is the best stage in order to get oils with a height antioxidant capacity.

Characterization of Microorganisms in Fish and Farmed Water from Sidi M’Hamed Ben Tiba Dam (Algeria)

Background: The production of fishery resources and the abundance of new species in our markets are becoming increasingly important. The consumption of fish continues to increase. Microbiological analysis of fish provides information on the diversity of the bacterial population abundant in these species. Methods: Our work was based on the isolation and identification of the bacterial flora of two fish species bred in extensive mode at the Sidi M’Hamed Ben Taiba dam (Barbel and Bighead carp). By introducing the influence environmental factors on the load and diversity of bacterial species by physicochemical (temperature, pH, turbidity, conductivity and dissolved oxygen) and bacteriological (search for total and faecal coliforms, enterococci and sulphate-reducing bacteria) analysis of the rearing water. Result: A variety of bacteria were isolated from the different compartments of the two fish species. Of which we were able to identify 12 species divided into 9 genera: Staphylococcus, Streptococcus, Pseudomomas, Serratia, Salmonella, Citrobacter, Proteus, Chrysobacterium, Stenotrophomonas and genera of lactic acid bacteria.