Transfer of Paralytic Shellfish Toxins via Marine Food Chains:A Simulated Experiment

Objective To study the transfer of paralytic shellfish toxins （PST） using four simulated marine food chains： dinoflagellate Alexandrium tamarense→Artemia Artemia salina→Mysid shrimp Neomysis awatschensis; A. tamarense→N. awatschensis; A. tamarense→A, salina→Perch Lateolabrax japonicus; and A. tamarense→L, japonicus. Methods The ingestion of A. tamarense, a producer of PST, by L. japonicus, N. awatschensis, and A. salina was first confirmed by microscopic observation of A. tamarense cells in the intestine samples of the three different organisms, and by the analysis of Chl.a levels in the samples. Toxin accumulation in L. japonicus and N. awatschensis directly from the feeding on A. tamarense or indirectly through the vector of A. salina was then studied, The toxicity of samples was measured using the AOAC mouse bioassay method, and the toxin content and profile of A. tamarense were analyzed by the HPLC method. Results Both A. salina and N. awatschensis could ingest A. tamarense cells. However, the ingestion capability of A. salina exceeded that of N. awatschensis. After the exposure to the culture of A. tamarense （2 000 cells·mL^-1） for 70 minutes, the content of Chl.a in A. salina and N. awatschensis reached 0.87 and 0.024 μg.mg^-1, respectively. Besides, A. tamarense cells existed in the intestines of L. japonicus, N. awatschensis and A. salina by microscopic observation. Therefore, the three organisms could ingest A. tamarense cells directly. A. salina could accumulate high content of PST, and the toxicity of A. salina in samples collected on days 1, 4, and 5 of the experiment was 2.18, 2.6, and 2.1 MU.g^-1, respectively. All extracts from the samples could lead to death of tested mice within 7 minutes, and the toxin content in anemia sample collected on the 1st day was estimated to be 1.65×10 ^5 μg STX equal/individual. Toxin accumulation in L japonicus and N. awatschensis directly from the feeding on A. tamarense or indirectly from the vector ofA. salina was also studied. The mice injected with extracts from L japonicus and N. awatschensis samples that accumulated PST either directly or indirectly showed PST intoxication symptoms, indicating that low levels of PST existed in these samples. Conclusion Paralytic shellfish toxins can be transferred to L. japonicus, N. awatschensis, and A. salina from A. tamarense directly or indirectly via the food chains.

Antibiotic susceptibility and molecular characterization of resistance genes among Escherichia coli and among Salmonella subsp. in chicken food chains

Objective: To investigate the occurrence of resistance genes among Escherichia coli(E. coli) and Salmonella subsp. isolated in chicken food chains in Phnom Penh, 2012–2013.Methods: Six hundred eighty two E. coli and 181 Salmonella Albany, Corvallis, and Kentucky strains were examined for susceptibilities to eight antimicrobials and following resistance genes were identified by PCR: blaTem, Str A, aad A, sul1, sul2, gyr A, Tet(A), and Tet(B).Results: E. coli presented high resistances to tetracycline, amoxicillin, and sulfamethoxazole(63.1%–76.1%). Salmonella Albany and Salmonella Kentucky traduced high resistance percentages to amoxicillin, tetracycline, sulfamethoxazole, and nalidixic acid(84.6%–100%). Among amoxicillin-resistant isolates, blaTemgenes were observed for 62% of E. coli isolates and 20% of 65 Salmonella Kentucky. The Str A gene was prevalent in 36% of 331 aminoglycoside-resistant E. coli and 90% of 40 aminoglycoside-resistant Salmonella Corvallis. The sul2 gene was predominant among sulfamethoxazole-resistant isolates, for 56% of 431 E. coli and 53% of 66 Salmonella Corvallis; the sul1 gene was observed in 54% of Salmonella Albany. The Tet(A) resistance gene was prevalent in E.coli(86%), Salmonella Corvallis(82%), Salmonella Kentucky(84%). High percentages of gyr A genes observed among nalidixic-acid resistant E. coli(91%), Salmonella Albany(92%), Salmonella Corvallis(75%) and Salmonella Kentucky(85%).Conclusions: Important occurrences of resistance gene were observed among E. coli and Salmonella in chicken food chains in Cambodia.

Poverty reduction through the development of inclusive food value chains

Propelled by urbanization,rising incomes,and changing diets,food markets have been expanding in Africa and South Asia,creating the vast potential for job and income opportunities along food supply chains and,hence,for poverty reduction.The novel coronavirus(COVID-19)that spread to a pandemic in early 2020 provokes enormous setbacks to this expansion.This,however,should provide lessons regarding the importance of resilient and inclusive food systems.Emergency responses to COVID-19 should consider interventions towards that end and leverage the opportunities provided by food markets growth as economies recover from the present economic recession.This paper assesses options of how this could be done by facilitating the better functioning and interconnectedness of the many small and medium-sized enterprises that are proliferating along the"hidden middle"of food value chains in storage,logistics,transportation,and wholesale and retail distribution.It also explores how policies can help smallholder farmers connect to this"hidden middle"in more gainful ways and help them climb out of poverty as well.

A Research on Global Supply Chains and Networking

It is argued that networking entails complex processes and should not be seen as a neutral term, devoid of relational content. Foremost, the institutional framework and economic environment in which research is conceived, designed, implemented, and evaluated need to be explicated. The paper takes the risk possibly over contextualizing processes in order to expose strong economic and institutional forces that are intersecting in food chains. By revealing many layers of economic and institutional context, we are able to show how major actors both inside and outside the food chains are endeavoring to constrain other actors into particular trajectories, thereby remaking the local and global structure, organization, and wider territoriality of the food chains.

Biotransfer of heavy metals along a soil-plant-insect-chicken food chain:Field study

The accumulation and transfer of Pb,Zn,Cu,and Cd along a soil-plant-insect-chicken food chain at contaminated sites were investigated.The study site nearing the Pb/Zn mine had been contaminated by heavy metals severely.Cadmium and Pb concentrations steadily declined with increasing trophic level（p 〈 0.01）,but concentrations of Zn and Cu slightly increased from plant to insect larva（p 〉 0.05）.The concentrations of heavy metals were the highest in chicken muscle,with lower values in liver and blood.The bioaccumulation of Pb was observed in chicken livers.The eliminations of Pb,Zn,Cu,and Cd via insect and chicken feces avoid metal bioaccumulation in insect and chicken body.These results suggest that the accumulation of heavy metals in specific animal organ of tissues could not be neglected,although transfer of metals to chicken from plant and insect was limited.

Preventing Hg Transference from Soil to Terrestrial Food Chain

Hg in acid soil could be activited by liming and become available to plant, if excessive or insufficient amount of lime was applied. The changes of Hg activity in acid soil with different rates of CaCO3 amendment Were studied by a pot experiment. To predict the adequate amount of lime application, a simple method using the pH (EDTA) as an indicator was suggested. The suitable range of lime application was the amount of lime addition when the pH of soil-EDTA system was.raised to 4.0-4.3.

Optimal harvesting for an age-dependent n-dimensional food chain model

This paper is concerned with optimal harvesting policy for an age-dependent n-dimensional food chain model. The existence and uniqueness of non-negative solution of the system are proved using the fixed point theorem. By Mazur＇s theorem, the existence of optimal control strategy is demonstrated and optimality conditions derived by means of normal cone.

A dynamic food-chain model and program for predicting the consequences of nuclear accident

A dynamic food chain model and program, DYFOM 95, for predicting the radiological consequences of nuclear accident has been developed, which is not only suitable to the West food chain but also to Chinese food chain. The following processes, caused by accident release which will make an impact on radionuclide concentration in the edible parts of vegetable were considered: dry and wet deposition interception and initial retention, translocation, percolation, root uptake and tillage. Activity intake rate of animals, effects of processing and activity intake of human through ingestion pathway ware also considered in calculations. The effects of leaf area index LAI of vegetable were considered in dry deposition model. A method for calculating the contribution of rain with different period and different intensity to total wet deposition was established. The program contains 1 main code and 5 sub codes to calculate dry and wet deposition on surface of vegetable and soil, translocation of nuclides in vegetable, nuclide concentration in the edible parts of vegetable and in animal products and activity intake of human and so on.

Impact of COVID-19 Epidemic on the International Food Supply Chain and Countermeasures of Shandong Province

The COVID-19 epidemic has exerted an impact on the global food supply chain,and also has contributed to the tendency of food hoarding and short supply;strong food demand has led to a rapid rise in international food prices,which has put enormous pressure on China's food import,and domestic food price showed a rise trend accordingly.In order to ensure sufficient and stable supply of China's food market,it is necessary to adhere to the food security strategy of"food self-sufficiency"for a long term.In the spring agricultural production,Shandong Province has taken effective measures to stabilize food production and achieved good results.It has not been greatly affected by the COVID-19 epidemic;however,under the continuous spread of foreign epidemics,we must adhere to the dual hard core operation of epidemic prevention and production,and explore the establishment of technical specifications for agricultural production under normal conditions for epidemic prevention and control to ensure the food security.

Deterministic and Stochastic Fractional-Order Hastings-Powell Food Chain Model

In this paper,a deterministic and stochastic fractional-order model of the tri-trophic food chain model incorporating harvesting is proposed and analysed.The interaction between prey,middle predator and top predator population is investigated.In order to clarify the characteristics of the proposed model,the analysis of existence,uniqueness,non-negativity and boundedness of the solutions of the proposed model are examined.Some sufficient conditions that ensure the local and global stability of equilibrium points are obtained.By using stability analysis of the fractional-order system,it is proved that if the basic reproduction number R_(0)<1,the predator free equilibrium point E_(1) is globally asymptotically stable.The occurrence of local bifurcation near the equilibrium points is investigated with the help of Sotomayor’s theorem.Some numerical examples are given to illustrate the theoretical findings.The impact of harvesting on prey and themiddle predator is studied.We conclude that harvesting parameters can control the dynamics of the middle predator.A numerical approximation method is developed for the proposed stochastic fractional-order model.

A DYNAMIC FOOD CHAIN MODEL FOR HONG KONG BASED ON RADFOOD MODEL AND BIRCHALL－JAMES ALGORITHM

In this paper a dynamic food chain model for Hong Kong which simulates the transfer of radioactive substances from a fallout deposition via the food chain into the human bodies is built. The model is based on the RADFOOD model and the BirchallJames algorithm. The radionuclides 13if and 90Sr representing the short-term and long-term risk situations have been studied as sample cases. Various types of crops,and the dietary pattern of the public have been collsidered. The resulting internal radiation doses have been calculated. The results are obtained for food consumption starting at various time after the fallout deposition and for different consumption durations.

Finite State Automaton for Food Traceability

To model the operation of food traceability, features of food supply chain are studied. The aim of the paper is to build an abstract model of food traceability, and to gain better understanding of food traceability and food safety. Based on the analysis of consumers＇ behavior of searching for traceability information, a finite state automaton for food traceability is presented by using automata theory. The states of the food supply chain are represented by a state transition diagram. The automaton in this paper simulates the entire food supply chain and provides a theoretical basis for the behavior description and structural design of a food traceability system.

The Micro-level Distributional Effects of Horticultural Export Value Chains Among Smallholders in Southern Ghana

Increasing foreign exchange problems and deteriorating prices of traditional exports have led policy makers and donor agencies to seek diversification in export crop production. In Ghana, crops such as pineapples and mangoes appear promising because of their high labour intensity and expanding demand for fruits in Europe. Notwithstanding, there is a possible trade-off between export and food crop production because of the possibility of resource re-allocation. So far the major concern of government has been the growth in export earnings while the micro-level distributional effects remain under-investigated. The study focused on a household survey undertaken in the forest and coastal-savannah transition zones, where the farming system has undergone transition from an established food-crop farming for urban markets to an intensive production of horticultural products for export. Logistic regression and Gini coefficient approaches were used to estimate the determinants of household food availability and income distribution respectively. Though, households engaged in export horticulture appear better-off than those that do not, the sole adoption of either staple or export crop is not sufficient for improving food availability. Consequently, linkages which allow simultaneous and reliably access to equitable distribution of resources and services are critical for household survival in competitive global food markets

Firm Size, Innovation and Vertical Integration Incentives： The Case of Food Supply Chain

This study aims to investigate and explore the relationship between vertical integration and the firm＇s innovativeness in food supply chain. For doing so, a two-stage least-squares model was used. It encompassed instrumental variables that attempt to describe the effective determinants of firm＇s vertical integration willingness. Results based on data concerning a set of 130 food-manufacturing firms, highlighted that vertical integration of a firm is strongly affected by internal incentives such as innovation rate and firm size. Moreover, it is simultaneously influenced by the economies of scale and some structure incentives. To conclude, results indicate globally that important and statistically significant differences exist across the studied firms and the small effective ones which acquire a high level of vertical integration.

A Food Traceability System Based on Blockchain and Radio Frequency Identification Technologies

The frequent occurrence of food safety accidents at the global level has triggered consumer sensitivity. Establishing a food traceability system can effectively guarantee food safety and increase consumer confidence and satisfaction. Existing food traceability systems often ignore environmental factors that affect food quality at all stages of the supply chain, and the authenticity of the information obtained through traceability is difficult to guarantee. In this study, a food supply chain traceability model was established based on blockchain and radio frequency identification (RFID) technologies. The model focused on the traceability of environmental data during the various stages of the food supply chain and combined a centralized database and blockchain for data storage. The lot identification data of the various supply chain stages were stored in a centralized database, while the environmental data were stored in a blockchain. Thereby, the authenticity and accuracy of the traceability data were ensured. The blockchain part of the model has been simulated in the Ethereum test environment, and the experiment has achieved traceability of temperature data.

Sustainability of Local Food Supply Chain in the New Theory Agriculture

World food production and its economic have rapidly grown over a decade; and number of supply chain management research has also increased in this field. However, this development relates to natural resources depletion and deterioration of quality of life in rural population, especially in smallholder farmers. Thailand has practiced the New Theory Agriculture （NTA）, one application aligned with sufficient economy. This theory not only remedies damaged natural resources but also helps smallholder farmers to improve quality of life; and it is analogous to local food supply chain theory, that is well-known in western countries. However, NTA has not been measured its sustainability. Following sustainable food criteria and sustainable agriculture criteria, this paper uses an Indicator of Sustainable Agricultural Practice （ISAP） to measure sustainability at farm level of small rural community＇s network called Inpaeng, a case study that has practiced NTA. The result of assessment in this case implies that NTA yields sustainability to local food supply chain more than monocrop system.

The Risk of <i>Fusarium</i>and Their Mycotoxins in the Food Chain

Fusarium sp. and mycotoxins of these species pose a major risk to consumer health, agriculture and the food industry. This paper is a worldwide bibliographic study on impact of Fusarium and mycotoxins on the food chain. The factors influencing the development of fungi Fusarium sp., the formation of mycotoxins and their microbiological risk on the food chain must be considered as a whole. For cereals and oilseeds before and after harvest, fungal infections and mycotoxin contamination present serious problems worldwide. This paper is an overview of the factors that include the microbiological risk and impact of Fusarium in the food chain mentioned in national and international studies. The methods and results obtained in this direction internationally are mentioned, such as: infrared spectroscopy, Raman spectrometry and hyperspectral imaging. Also, in review are presented solutions to reduce this impact on the food chain.

Slackening of Food Supply Chain during COVID-19 and Affecting Livelihood - A Global Concern

The outbreak of COVID-19 has brought about another age on world as the human civilization is restricted in many aspects of everyday lives.There is no exception in the sector of food production and the supply chain of food.Due to constraints on demand,shutting of food production facilities,financial limitations,enterprise operations and delivery of different food items have been interrupted in the food supply chain.Every nation must comprehend the importance of the situation according to the spreading scenario of the ongoing pandemic.The probability of transmission via the food sector is regarded inconsequential,and the public authorities do not believe it necessary to follow COVID into workplaces.The unfavourable effects on the climate,the food framework and the people of the foodstuffs network are evident.An installation for the food supply chain should focus on amenities such as maintaining the safety and health of employees and changing working circumstances.This paper aims at discussing the effects of COVID-19 on the socio-economic status of human being including the negative impacts on the agriculture and food supply chain.

Enabling affordances of blockchain in agri-food supply chains:A value-driver framework using Q-methodology

The application of blockchain beyond cryptocurrencies has received increasing attention from industry and scholars alike.Given predicted looming food crises,some of the most impactful deployments of blockchains are likely to concern food supply chains.This study outlined how blockchain adoption can result in positive affordances in the food supply chain.Using Q-methodology,this study explored the current status of the agri-food supply chain and how blockchain technology could be useful in addressing existing challenges.This theorization leads to the proposition of the 3TIC value-driver framework for determining the enabling affordances of blockchain that would increase shared value for stakeholders.First,we propose a framework based on the most promising features of blockchain technology to overcome current challenges in the agri-food industry.Our value-driver framework is driven by the Q-study findings of respondents closely associated with the agri-food supply chain.This framework can provide supply chain stakeholders with a clear perception of blockchain affordances and serve as a guideline for utilizing appropriate features of technology that match organizations’capabilities,core competencies,goals,and limitations.Therefore,it could assist top-level decision-makers in systematically evaluating parts of the organization to focus on and improve the infrastructure for successful blockchain implementation along the agri-food supply chain.We conclude by noting certain significant challenges that must be carefully addressed to successfully adopt blockchain technology.