Waste disposal is a serious global environmental threat resulting in heavy metal pollution. Contaminated soil with heavy metals has become a concern for agricultural scientists because of the progress made in agricultural product safety. Heavy metals are metalloids with biological toxicity. The most common are arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn). These metals exist throughout the terrestrial environment and produced from anthropogenic and natural activities. Recently, the landfills have been reported as persecutor to soil contamination, but still, there is no promising way proposed for the waste disposal management in some developing countries. This is the biggest threat to the soil, crops, and the communities living around the dumpsites. Soil polluted with heavy metals result in human health risks, groundwater pollution, plant phytotoxicity and decline in crop and soil production. Absorption of heavy metals through plant roots is the major pathway in which heavy metals penetrate the food chain and their successive crowding along the food chain is a critical threat to animal and human health. The previous findings reported that soil, vegetables, and other food crops around dumpsites are contaminated with heavy metals. The soil contaminated with heavy metals is a leading cause of vegetables and other crops contamination, which is a cause of adverse health outcomes in developing countries’ cities. Therefore, there is an urgent need for continuous monitoring of heavy metals in different open dumpsites. The necessary measures to reduce the high concentration of heavy metals in the soil and crops should be put in place. This paper aimed to review the harmful impacts of heavy metal contamination to the soil and crops grown in the vicinity of dumpsites, but also several techniques treating heavy metals pollution in the soil were discussed in this review.
{"title":"Harmful Impacts of Heavy Metal Contamination in the Soil and Crops Grown Around Dumpsites","authors":"P. Nyiramigisha, Komariah, Sajidan","doi":"10.7831/ras.9.0_271","DOIUrl":"https://doi.org/10.7831/ras.9.0_271","url":null,"abstract":"Waste disposal is a serious global environmental threat resulting in heavy metal pollution. Contaminated soil with heavy metals has become a concern for agricultural scientists because of the progress made in agricultural product safety. Heavy metals are metalloids with biological toxicity. The most common are arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn). These metals exist throughout the terrestrial environment and produced from anthropogenic and natural activities. Recently, the landfills have been reported as persecutor to soil contamination, but still, there is no promising way proposed for the waste disposal management in some developing countries. This is the biggest threat to the soil, crops, and the communities living around the dumpsites. Soil polluted with heavy metals result in human health risks, groundwater pollution, plant phytotoxicity and decline in crop and soil production. Absorption of heavy metals through plant roots is the major pathway in which heavy metals penetrate the food chain and their successive crowding along the food chain is a critical threat to animal and human health. The previous findings reported that soil, vegetables, and other food crops around dumpsites are contaminated with heavy metals. The soil contaminated with heavy metals is a leading cause of vegetables and other crops contamination, which is a cause of adverse health outcomes in developing countries’ cities. Therefore, there is an urgent need for continuous monitoring of heavy metals in different open dumpsites. The necessary measures to reduce the high concentration of heavy metals in the soil and crops should be put in place. This paper aimed to review the harmful impacts of heavy metal contamination to the soil and crops grown in the vicinity of dumpsites, but also several techniques treating heavy metals pollution in the soil were discussed in this review.","PeriodicalId":37168,"journal":{"name":"Reviews in Agricultural Science","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71254270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bakanae disease, caused by Fusarium fujikuroi , is a serious problem in rice production. This disease is widespread across the world and leads to substantial yield losses. F. fujikuroi is known to produce various secondary metabolites, including the plant hormone gibberellin, which induces typical bakanae symptoms. In this article, authors overviewed the methods for controlling bakanae disease, including the use of host resistance, chemical compounds, biocontrol agents, natural products, and physical methods. Although various strategies have been applied to control bakanae disease, the disease is not yet completely prevented. Authors discuss the advantages and disadvantages of these various methods. In addition, the mode of action of major fungicides and the resistance mechanisms to these fungicides were outlined. These information contribute to the development of more effective methods for controlling bakanae disease.
{"title":"Various Methods for Controlling the Bakanae Disease in Rice","authors":"Li Jing, H. Suga","doi":"10.7831/ras.9.0_195","DOIUrl":"https://doi.org/10.7831/ras.9.0_195","url":null,"abstract":"Bakanae disease, caused by Fusarium fujikuroi , is a serious problem in rice production. This disease is widespread across the world and leads to substantial yield losses. F. fujikuroi is known to produce various secondary metabolites, including the plant hormone gibberellin, which induces typical bakanae symptoms. In this article, authors overviewed the methods for controlling bakanae disease, including the use of host resistance, chemical compounds, biocontrol agents, natural products, and physical methods. Although various strategies have been applied to control bakanae disease, the disease is not yet completely prevented. Authors discuss the advantages and disadvantages of these various methods. In addition, the mode of action of major fungicides and the resistance mechanisms to these fungicides were outlined. These information contribute to the development of more effective methods for controlling bakanae disease.","PeriodicalId":37168,"journal":{"name":"Reviews in Agricultural Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71254492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ribonucleic acid (RNA) quantification is an essential technique in biology. There has been remarkable progress in RNA quantification techniques over the recent years; however, the specificity of these techniques to quantify a very small amount of RNA is doubtful because of factors which can inhibit precise quantification. To develop a technique that leads to the most sensitive RNA quantification, these problems must be overcome. In this article, we first review the factors that inhibit precise quantification of RNA: the quality of RNA, secondary structure of RNA, efficiency of the enzyme reaction, annealing conditions, limitations of the experimental protocol and equipment, and detection sensitivity of the equipment. Next, we discuss the possible methods which contribute to these factors: RNA quality control focused on target RNA degradation, isothermal amplification, techniques for avoiding amplification errors, RNase H-dependent PCR, targeting using a fluorescent-labeled probe, targeting using a padlock probe, bridged/locked nucleic acid (BNA/LNA) and peptide nucleic acid (PNA), and the clustered regularly interspaced short palindromic repeat (CRISPR) system. One of the goals for the development of an ultrasensitive RNA quantification technique is the absolute quantification of RNA. Here, we discuss the techniques used for this type of RNA quantification.
{"title":"Challenges for Accurate Quantification of RNA","authors":"Takema Hasegawa, D. Hapsari, H. Iwahashi","doi":"10.7831/RAS.9.0_1","DOIUrl":"https://doi.org/10.7831/RAS.9.0_1","url":null,"abstract":"Ribonucleic acid (RNA) quantification is an essential technique in biology. There has been remarkable progress in RNA quantification techniques over the recent years; however, the specificity of these techniques to quantify a very small amount of RNA is doubtful because of factors which can inhibit precise quantification. To develop a technique that leads to the most sensitive RNA quantification, these problems must be overcome. In this article, we first review the factors that inhibit precise quantification of RNA: the quality of RNA, secondary structure of RNA, efficiency of the enzyme reaction, annealing conditions, limitations of the experimental protocol and equipment, and detection sensitivity of the equipment. Next, we discuss the possible methods which contribute to these factors: RNA quality control focused on target RNA degradation, isothermal amplification, techniques for avoiding amplification errors, RNase H-dependent PCR, targeting using a fluorescent-labeled probe, targeting using a padlock probe, bridged/locked nucleic acid (BNA/LNA) and peptide nucleic acid (PNA), and the clustered regularly interspaced short palindromic repeat (CRISPR) system. One of the goals for the development of an ultrasensitive RNA quantification technique is the absolute quantification of RNA. Here, we discuss the techniques used for this type of RNA quantification.","PeriodicalId":37168,"journal":{"name":"Reviews in Agricultural Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71254047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The water-soluble dietary fiber, pectin, is a polysaccharide present in the cell wall of terrestrial plants. It is a polymer of Dgalacturonic acid polymerized by alpha-1,4 linkages and has side chains composed of 13 different sugars. Due to its complex chemical structure, pectin has a number of physical characteristics, including gelling properties and viscosity, and has physiological functions in vivo. The degree of esterification of the pectin main chain affects gelling. In addition, the side chain structure has been shown to affect antitumor activity and regulation of intestinal immunity, which are well-known physiological functions of pectin, and the rhamnogalacturonan-I region is particularly important. This review discusses the correlations between the molecular structure of pectin and its functions. Not only that, we will discuss the mechanisms and physiological significance of small intestinal villus morphological changes, which is still a mysterious function of pectin.
{"title":"Involvement of the Complex Polysaccharide Structure of Pectin in Regulation of Biological Functions","authors":"S. Gotoh, K. Kitaguchi, T. Yabe","doi":"10.7831/ras.9.0_221","DOIUrl":"https://doi.org/10.7831/ras.9.0_221","url":null,"abstract":"The water-soluble dietary fiber, pectin, is a polysaccharide present in the cell wall of terrestrial plants. It is a polymer of Dgalacturonic acid polymerized by alpha-1,4 linkages and has side chains composed of 13 different sugars. Due to its complex chemical structure, pectin has a number of physical characteristics, including gelling properties and viscosity, and has physiological functions in vivo. The degree of esterification of the pectin main chain affects gelling. In addition, the side chain structure has been shown to affect antitumor activity and regulation of intestinal immunity, which are well-known physiological functions of pectin, and the rhamnogalacturonan-I region is particularly important. This review discusses the correlations between the molecular structure of pectin and its functions. Not only that, we will discuss the mechanisms and physiological significance of small intestinal villus morphological changes, which is still a mysterious function of pectin.","PeriodicalId":37168,"journal":{"name":"Reviews in Agricultural Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71254435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Agriculture plays an important role in Indonesia, but it is often neglected by various parties. As a result, farmers face many problems particularly when it comes to selling their products. The solution is to strengthen the agricultural institutions, especially the auction market. This institution has proven to provide many benefits for all parties. Farmers' products are sold in large quantities at high prices and strengthen the existence of farmer groups. Consumers also get high-quality products while the industry will get a continual supply of raw materials. For the economy, the auction market has been shown to improve agricultural trade efficiency and contribute to government revenue. However, the auction market's performance is still not optimal due to ack of rigorous rules, lack of quantity and quality human resources, lack of funds and infrastructure, competition with traders, and weak support from other parties. The auction market needs to make a good collaboration with suppliers, buyers, financial institutions, and the government.
{"title":"Development Strategies of the Local Auction Market of Agricultural Product in Indonesia","authors":"A. Nugroho","doi":"10.7831/RAS.9.0_56","DOIUrl":"https://doi.org/10.7831/RAS.9.0_56","url":null,"abstract":"Agriculture plays an important role in Indonesia, but it is often neglected by various parties. As a result, farmers face many problems particularly when it comes to selling their products. The solution is to strengthen the agricultural institutions, especially the auction market. This institution has proven to provide many benefits for all parties. Farmers' products are sold in large quantities at high prices and strengthen the existence of farmer groups. Consumers also get high-quality products while the industry will get a continual supply of raw materials. For the economy, the auction market has been shown to improve agricultural trade efficiency and contribute to government revenue. However, the auction market's performance is still not optimal due to ack of rigorous rules, lack of quantity and quality human resources, lack of funds and infrastructure, competition with traders, and weak support from other parties. The auction market needs to make a good collaboration with suppliers, buyers, financial institutions, and the government.","PeriodicalId":37168,"journal":{"name":"Reviews in Agricultural Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71254521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Hasan, S. Takashi, M. M. Alam, R. Ali, Kumer Saha Chayan
Mechanized agriculture plays a key role in the overall socio-economic development in terms of food security, value addition, employment, poverty alleviation and export earnings. Due to the migration of agricultural labor in non-farm sectors and increasing climate vulnerability, it is a great challenge to keep pace of food production for the exponential growth of population, especially in the developing countries. Hence, the main aim of this study was to examine the present status and impact of modern rice harvesting practices over traditional manual harvesting. In order to investigate the interactions between modern rice harvesting technologies and benefits of use, we reviewed overall scenarios of rice harvesting in the world along with identified problems due to present practices and the benefit of using modern technologies including precision agriculture. The major findings of this study were as follows: agriculture in most of the developing countries were characterized by low productivity due to less practice of modern technologies, less management of modern technologies, inadequate control of repeated crop losses due to natural calamities. Identified problems in traditional manual rice harvesting were: labor crisis at peak harvesting period, high harvesting cost as the traditional method was labor intensive and high labor wages, delayed harvesting due to the unavailability of labors, more grain/yield losses owing to the over maturity. Furthermore, identified benefits in modern rice harvesting practices were to save harvesting time, cost and labor involvement with reducing grain/yield loss and human drudgery. The further benefits were enhancing the income through custom hire services and creating a new employment opportunity in technology operation and maintenance. The results indicated that adoption of appropriate rice harvesting technology in the developing countries is urgently needed to increase the cropping intensity, crop productivity and economic emancipation through less inputs of time, labor and cost.
{"title":"Impact of Modern Rice Harvesting Practices over Traditional Ones","authors":"K. Hasan, S. Takashi, M. M. Alam, R. Ali, Kumer Saha Chayan","doi":"10.7831/ras.8.0_89","DOIUrl":"https://doi.org/10.7831/ras.8.0_89","url":null,"abstract":"Mechanized agriculture plays a key role in the overall socio-economic development in terms of food security, value addition, employment, poverty alleviation and export earnings. Due to the migration of agricultural labor in non-farm sectors and increasing climate vulnerability, it is a great challenge to keep pace of food production for the exponential growth of population, especially in the developing countries. Hence, the main aim of this study was to examine the present status and impact of modern rice harvesting practices over traditional manual harvesting. In order to investigate the interactions between modern rice harvesting technologies and benefits of use, we reviewed overall scenarios of rice harvesting in the world along with identified problems due to present practices and the benefit of using modern technologies including precision agriculture. The major findings of this study were as follows: agriculture in most of the developing countries were characterized by low productivity due to less practice of modern technologies, less management of modern technologies, inadequate control of repeated crop losses due to natural calamities. Identified problems in traditional manual rice harvesting were: labor crisis at peak harvesting period, high harvesting cost as the traditional method was labor intensive and high labor wages, delayed harvesting due to the unavailability of labors, more grain/yield losses owing to the over maturity. Furthermore, identified benefits in modern rice harvesting practices were to save harvesting time, cost and labor involvement with reducing grain/yield loss and human drudgery. The further benefits were enhancing the income through custom hire services and creating a new employment opportunity in technology operation and maintenance. The results indicated that adoption of appropriate rice harvesting technology in the developing countries is urgently needed to increase the cropping intensity, crop productivity and economic emancipation through less inputs of time, labor and cost.","PeriodicalId":37168,"journal":{"name":"Reviews in Agricultural Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71253861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The generally-accepted tadpole shrimp (notostracan) classification of Longhurst does not include information on the world richest Triops collection in Budapest, Hungary. Besides, his “Triops granarius” (an ‘Asian’ species in the broadest sense), which is ranging from Africa through Eurasia and even to Japan, has been regarded as a single cosmopolitan species with wide morphological variations. However, the morphological and molecular analyses conducted by me revealed that it was a hotchpotch of multiple species. If a regional endemic species has been misidentified as a broadly-distributed one (to sum up, this is the most problematic matter of Longhurst’s classification), then any zoogeographical results based on this would be far from the nature; and as such I opted to verify its species definition. Invasive alien species of tadpole shrimp Triops were first introduced into rice fields of Japan in the 1910s and have spread around Japan. The expansion of Triops has resulted in negative ecological and potential economic impact. Regarding their establishment or extinction patterns, I built a simple mathematical competition model among two self-fertile and one related sexual Triops species of Japan, incorporating reproductive interference. Intense reproductive interference drove the competition to sexual exclusion of self-fertile species. Nonetheless, even under intense reproductive interference, the Allee effect (which reduces the population growth rate of sexual species with low density) allowed self-fertile species to survive when the competition started with the lower densities; conversely sexual species to be left alive when the competition started with the higher densities.
{"title":"Invasive Alien Species Triops (Branchiopoda, Notostraca) in Japan and Its Ecological and Economic Impact","authors":"H. Naganawa","doi":"10.7831/ras.8.0_138","DOIUrl":"https://doi.org/10.7831/ras.8.0_138","url":null,"abstract":"The generally-accepted tadpole shrimp (notostracan) classification of Longhurst does not include information on the world richest Triops collection in Budapest, Hungary. Besides, his “Triops granarius” (an ‘Asian’ species in the broadest sense), which is ranging from Africa through Eurasia and even to Japan, has been regarded as a single cosmopolitan species with wide morphological variations. However, the morphological and molecular analyses conducted by me revealed that it was a hotchpotch of multiple species. If a regional endemic species has been misidentified as a broadly-distributed one (to sum up, this is the most problematic matter of Longhurst’s classification), then any zoogeographical results based on this would be far from the nature; and as such I opted to verify its species definition. Invasive alien species of tadpole shrimp Triops were first introduced into rice fields of Japan in the 1910s and have spread around Japan. The expansion of Triops has resulted in negative ecological and potential economic impact. Regarding their establishment or extinction patterns, I built a simple mathematical competition model among two self-fertile and one related sexual Triops species of Japan, incorporating reproductive interference. Intense reproductive interference drove the competition to sexual exclusion of self-fertile species. Nonetheless, even under intense reproductive interference, the Allee effect (which reduces the population growth rate of sexual species with low density) allowed self-fertile species to survive when the competition started with the lower densities; conversely sexual species to be left alive when the competition started with the higher densities.","PeriodicalId":37168,"journal":{"name":"Reviews in Agricultural Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71253698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Slope stability is always one of the greatest issues of concern in geotechnical engineering. In slope stability analyses, the residual strength of slip zones is one of the most important parameters for understanding the reactivation mechanisms and for evaluating the stability of slopes. The kinds of soils, the situations of the soils, and the test conditions are the three main aspects that affect the residual strength. Among the test conditions, the selection of the shear testing apparatus, the normal stress, the overconsolidation ratio, the shear rate, and the acceleration are the main critical factors that affect the residual strength of soils. This paper firstly presents a systematic literature review of the factors that influence the residual strength of soils under certain test conditions, which can help obtain the residual strength accurately and easily in a geotechnical research. The paper also summarizes the available indexes, such as the Atterberg limits, for determining the residual strength. Moreover, this paper highlights future research challenges with an aim to clarify the effect of acceleration on the residual strength in a wider range which has not been well researched, but which needs to be explored further.
{"title":"Determination of Residual Strength of Soils for Slope Stability Analysis: State of the Art Review","authors":"Chen Fang, H. Shimizu, T. Nishiyama, S. Nishimura","doi":"10.7831/ras.8.0_46","DOIUrl":"https://doi.org/10.7831/ras.8.0_46","url":null,"abstract":"Slope stability is always one of the greatest issues of concern in geotechnical engineering. In slope stability analyses, the residual strength of slip zones is one of the most important parameters for understanding the reactivation mechanisms and for evaluating the stability of slopes. The kinds of soils, the situations of the soils, and the test conditions are the three main aspects that affect the residual strength. Among the test conditions, the selection of the shear testing apparatus, the normal stress, the overconsolidation ratio, the shear rate, and the acceleration are the main critical factors that affect the residual strength of soils. This paper firstly presents a systematic literature review of the factors that influence the residual strength of soils under certain test conditions, which can help obtain the residual strength accurately and easily in a geotechnical research. The paper also summarizes the available indexes, such as the Atterberg limits, for determining the residual strength. Moreover, this paper highlights future research challenges with an aim to clarify the effect of acceleration on the residual strength in a wider range which has not been well researched, but which needs to be explored further.","PeriodicalId":37168,"journal":{"name":"Reviews in Agricultural Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.7831/ras.8.0_46","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71253733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dams and reservoirs are artificial structures built to actively and effectively manage and exploit water resources. However, dam failures may induce catastrophes that often threaten human life and all socio-economic activities. Among the causes of dam failures, hydraulic fracturing is considered to be one of the most probable as it brings about concentrated leakage that results in the failures or incidents of fill dams, especially at the first reservoir filling. This paper focuses on reviewing studies on the mechanism of hydraulic fracturing in embankment dams. The statistics for many dam failures and incidents related to hydraulic fracturing are provided. Some measures for preventing hydraulic fracturing are also reviewed. Based on the review, a summary of incidents and failures related to hydraulic fracturing in embankment dams is given and possible future studies are discussed.
{"title":"Risk of Embankment Dam Failure from Viewpoint of Hydraulic Fracturing: Statistics, Mechanism, and Measures","authors":"D. Tran, S. Nishimura, M. Senge, T. Nishiyama","doi":"10.7831/ras.8.0_216","DOIUrl":"https://doi.org/10.7831/ras.8.0_216","url":null,"abstract":"Dams and reservoirs are artificial structures built to actively and effectively manage and exploit water resources. However, dam failures may induce catastrophes that often threaten human life and all socio-economic activities. Among the causes of dam failures, hydraulic fracturing is considered to be one of the most probable as it brings about concentrated leakage that results in the failures or incidents of fill dams, especially at the first reservoir filling. This paper focuses on reviewing studies on the mechanism of hydraulic fracturing in embankment dams. The statistics for many dam failures and incidents related to hydraulic fracturing are provided. Some measures for preventing hydraulic fracturing are also reviewed. Based on the review, a summary of incidents and failures related to hydraulic fracturing in embankment dams is given and possible future studies are discussed.","PeriodicalId":37168,"journal":{"name":"Reviews in Agricultural Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71253848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tilapia breeds effortlessly in captivity, with this attribute which is considered as the “Achilles heel” of the species, because it predisposes pond systems to overcrowding and low weight at harvest. Efforts to mitigate this shortcoming include mono-sex culture using exogenous hormone to reverse the sex of sexually undifferentiated fish. This is premised on the fact that improvement in the growth by mono-sex culture will lead to shortened production times and a more uniform weight at harvest, which will ultimately benefit the producers. However, the use of exogenous hormones in aquaculture has recently raised concerns about the effect on farm workers, consumers and on the environment. Recently research has focused on the use of substances of plants origin which mimic the action of hormones as a potential approach to achieve sex reversal in fish. Pawpaw ( Carica papaya ) seed contains phytochemicals that hold great promise as a sex reversal and a reproductive inhibition agent in aquaculture. The purpose of this study was to conduct a systematic review of the relevant literature on the possibility of using a less harmful phytochemicals abundant in the plant to effect sex reversal of sexually undifferentiated tilapia.
{"title":"Use of Pawpaw (Carica papaya) Seed in Tilapia Sex Reversal","authors":"V. O. Omeje, H. Lambrechts, D. Brink","doi":"10.7831/ras.8.0_230","DOIUrl":"https://doi.org/10.7831/ras.8.0_230","url":null,"abstract":"Tilapia breeds effortlessly in captivity, with this attribute which is considered as the “Achilles heel” of the species, because it predisposes pond systems to overcrowding and low weight at harvest. Efforts to mitigate this shortcoming include mono-sex culture using exogenous hormone to reverse the sex of sexually undifferentiated fish. This is premised on the fact that improvement in the growth by mono-sex culture will lead to shortened production times and a more uniform weight at harvest, which will ultimately benefit the producers. However, the use of exogenous hormones in aquaculture has recently raised concerns about the effect on farm workers, consumers and on the environment. Recently research has focused on the use of substances of plants origin which mimic the action of hormones as a potential approach to achieve sex reversal in fish. Pawpaw ( Carica papaya ) seed contains phytochemicals that hold great promise as a sex reversal and a reproductive inhibition agent in aquaculture. The purpose of this study was to conduct a systematic review of the relevant literature on the possibility of using a less harmful phytochemicals abundant in the plant to effect sex reversal of sexually undifferentiated tilapia.","PeriodicalId":37168,"journal":{"name":"Reviews in Agricultural Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71254034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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