Isolation and characterization of novel enzymatic activities from gut metagenomes to support lignocellulose breakdown

The agricultural sector produces a large amount of organic waste as by-products (crop remains, foliage, seed pods, straw, etc.). Currently, these materials are not properly treated and their uncontrolled disposal can lead to many problems. In many countries crop remains are burned on the field, sometimes causing severe air pollution as well as damage health. This contributes to climate change and could impact the climate further to the point of irreversible damage. To realize a sustainable agriculture, organic wastes should not be disposed or burned but used as a cheap source for biomaterials. In line with the philosophy of the bio-based economy, agricultural waste is recycled and used as raw material in the chemical industry, replacing fossil fuels. However, the process of converting agricultural waste into useful products is not efficient and can be improved further for optimization. One of the dominant components of agricultural waste is lignocellulose, a complex biomaterial that is difficult to handle. To break down this complex structure, large amounts of energy or chemicals for treatment are required. This thesis aims to explore novel natural biological catalysts that can help to degrade lignocellulose and deliver useful compounds for the bio-based chemical industry. To discover such novel catalysts, the digestive systems of a number of different animals: goats, springtails, isopods and termites were investigated. Animal guts are mini ecosystems that contain many unknown interesting bacteria. These microorganisms are adapted to the host and might have interesting properties that can be explored. By looking at these organisms and their catalysts it is possible to identify and mine novel genes that can be used to breakdown biomass. This process creates substrates that can be used for many other procedures. In this thesis my main focus was on enzymes that can break down carbohydrates. The various bonds in complex carbohydrate molecules are cleaved by different enzymes. Every bacterium has a suit of carbohydrate-active enzymes, called CAZymes. Using metagenomics and bioinformatic tools to explore the genomes of microbial communities in search of novel CAZymes. Unlike traditional culturing methods, metagenomics is aimed at the whole genome of the communities involved, that is, all bacteria jointly. In addition, genes encoding antibiotic resistance, and the production of secondary metabolites were investigated since these two gene categories greatly contribute to the survival of bacteria in complex microbial communities. The work on this thesis shows the possibilities of using bioinformatic tools to investigate the microbiome communities and mine for interesting enzymes from metagenomes. The bacterial community appears to be very diverse and different between hosts. However, at the enzymatic level there is a core group of carbohydrate enzymes and antibiotic resistances. Some of the studied enzymes show the potential for bio-applications. The method could be further tested on different animal metagenomes. With the expansion of sequencing and bioinformatic tools as well as advances in computing and machine learning, it is possible to use and understand more about the natural environment. These tools could help to mine enzymes with interesting properties. Together with enzyme characterization, the bioinformatic tools could be improved further. When the whole process is streamlined and part of a pipeline, a large number of enzymes can be identified and tested to find optimal conditions for their action. These enzymes can be combined together to create cocktails, which can efficiently breakdown biomass. Since the enzymes are natural and the products are used as substrates, little energy and resources are wasted. Beneficial enzymes and bacteria are also preserved and promoted. By creating a recycling plant, agricultural waste can turn into new substrates and products, which in turn can help to improve the environment

The effect of inflation on income inequality in developing economies: Empirical evidence

Inflation is a controversial topic among economists because, on the one hand, it increases the cost of living, leading to social instability, but on the other hand, it increases savings - investments and improves capital accumulation for the development of the private sector, leading to economic growth and development. Meanwhile, income inequality is one of the eight-millennium goals that most developing economies are facing because severe inequality can lead to political instability. Does inflation enhance income inequality? This paper looks for the answer by employing the difference GMM Arellano-Bond estimators to study the effect of inflation on income inequality for a balanced panel dataset of 35 developing economies between 2002 and 2021. The results show that inflation increases income inequality. Furthermore, public spending, economic growth, and unemployment are significant determinants of income inequality in these economies. The findings in this paper suggest some crucial implications for developing economies in controlling inflation to limit the increase in income inequality

DEVELOPMENT OF A MODEL FOR EVALUATING THE EFFECTIVENESS OF ACCOUNTING INFORMATION SYSTEMS IN CO-OPERATIVES IN THUA THIEN HUE PROVINCE

The purpose of this paper is to develop an evaluation model that can be used to predict Accounting Information System (AIS) effectiveness. Direct interviews and questionnaires were used to collect data from a random sample of Co-operatives located in Thua Thien Hue province, Vietnam. By using Factor Analysis, Cronbach’s Alpha test, Linear Regression Model, 138 responses were analysed. In comparison with previously AIS studies, the results reveal that six factors evaluated the effectiveness probability of the AIS. Implementation of AIS at these Co-operatives resulted in the improvement of managers’ decision-making processes, internal control, performance measures and the quality of the financial reports as well as user information satisfactions. It also facilitated the process of financial transactions. The model can be used to assist software users to not only evaluate the success of AIS implementation, but also develop strategies accruing the considerable benefits from computerized accounting systems. The paper contributes to the continuing research in AIS innovations in the small business context. Keywords: Accounting information systems, Model for effectiveness evaluation, Quality of financial reporting, Internal control, Decision making, Performance measures, User information satisfactions, Financial transactions

DEVELOPMENT OF A MODEL FOR EVALUATING THE EFFECTIVENESS OF ACCOUNTING INFORMATION SYSTEMS IN CO-OPERATIVES IN THUA THIEN HUE PROVINCE

The purpose of this paper is to develop an evaluation model that can be used to predict Accounting Information System (AIS) effectiveness. Direct interviews and questionnaires were used to collect data from a random sample of Co-operatives located in Thua Thien Hue province, Vietnam. By using Factor Analysis, Cronbach’s Alpha test, Linear Regression Model, 138 responses were analysed. In comparison with previously AIS studies, the results reveal that six factors evaluated the effectiveness probability of the AIS. Implementation of AIS at these Co-operatives resulted in the improvement of managers’ decision-making processes, internal control, performance measures and the quality of the financial reports as well as user information satisfactions. It also facilitated the process of financial transactions. The model can be used to assist software users to not only evaluate the success of AIS implementation, but also develop strategies accruing the considerable benefits from computerized accounting systems. The paper contributes to the continuing research in AIS innovations in the small business context. Keywords: Accounting information systems, Model for effectiveness evaluation, Quality of financial reporting, Internal control, Decision making, Performance measures, User information satisfactions, Financial transactions

Các nhân tố ảnh hưởng đến cơ hội việc làm của sinh viên mới ra trường trong thời kỳ COVID-19: nghiên cứu tại thành phố Hà Nội

Vấn đề việc làm đã trở thành một chủ đề cấp thiết, đặc biệt là trong bối cảnh dịch COVID-19. Tuy nhiên, ở Việt Nam vấn đề này vẫn chưa có hướng giải quyết triệt để. Bài viết nhằm phân tích các yếu tố ảnh hưởng đến cơ hội việc làm của sinh viên mới ra trường trong thời kỳ COVID-19 trên địa bàn thành phố Hà Nội. Phương pháp phân tích hồi quy đa biến được sử dụng để phân tích dữ liệu từ 150 người tham gia khảo sát. Kết quả nghiên cứu chỉ ra rằng, trong 4 nhân tố nghiên cứu, nhân tố Kỹ năng mềm và học lực có tác động thuận chiều lớn nhất đến “Cơ hội việc làm”, tiếp đến là nhân tố trình độ chuyên môn và kinh nghiệm. Nhân tố Mạng lưới mối quan hệ bị phủ định ảnh hưởng đến “Cơ hội việc làm”, còn nhân tố Nhu cầu nhà tuyển dụng bị loại ra khỏi mô hình vì có độ tin cậy thấp. Trên cơ sở đó, nghiên cứu đưa ra một số đề xuất cải thiện vấn đề việc làm của sinh viên mới ra trường trên địa bàn Thành phố Hà Nội trong bối cảnh dịch COVID-19