Identification of Factors that Promote the Growth of Dormant Mycobacterium avium subsp. paratuberculosis

Johne\u27s disease, which is caused by the acid-fast bacterium Mycobacterium avium subspecies paratuberculosis (Mpt), is a chronic, inflammatory intestinal disease that primarily affects ruminants. This disease has a significant effect on the economics of dairy farming. Mpt has a remarkable ability to survive in host tissues for 2-6 years without producing any signs of infection. However, the reliability of diagnostic techniques is limited only to those animals with clinical disease. This may be due to the entry of the organism into a dormant state, which has been reported for other mycobacteria. Reversion to the actively growing state (resuscitation) would improve the sensitivity of diagnostic culture; however, the substances effecting resuscitation have not been defined. Previous work in our laboratory showed that conditioned medium obtained from starvation-dormant Mpt (SDCM) enhanced the resuscitation of dormant Mpt. Research by others demonstrated that resuscitation of other dormant mycobacterial pathogens was enhanced by resuscitation promoting factors (Rpf), a class of 17-19 kDa proteins that are secreted by these organisms. We therefore hypothesized that one or more Rpf was responsible for the resuscitative activity in SDCM. In this study, we sought to identify and characterize fractions of SDCM that contain resuscitative activity. SDCM was fractionated into 6 molecular weight classes, and each fraction was tested for the ability to promote the resuscitation of anaerobically dormant Mpt responder cells. Most (if not all) of this activity was confined to a fraction containing molecules with a molecular weight of 5 kDa or less (F5). To characterize F5, this fraction was subjected to heat, protease treatment, and combinations of the two. The resuscitative activity of F5 was stable at high temperatures (65oC and 80oC), resistant to trypsin and thermolysin, and was not impaired by a combination of heat and protease treatment. Growth factors in F5 were concluded to be non-protein in nature, thereby refuting our hypothesis. F5 prepared from 5-, 6, and 8-month-old cultures were analyzed by reversed-phase high performance liquid chromatography to compare peptide and acyl homoserine lactone (AHL) components in F5. AHL peaks steadily accumulated with time, whereas peptide analysis identified hydrophobic peaks that generally diminished over time, and hydrophilic peaks that increased with time. Further characterization and identification of this Mpt-resuscitative growth factor will be necessary in order to test its ability to enhance the recovery of dormant Mpt in clinical specimens

Corporate Social Responsibility - On Aspect of Environmental Protection in Vietnam Today

Through collecting secondary data by deploying desk review method and collecting primary data by using various qualitative methods including observations and interviews of business owners, workers and consumers, the article argues that the corporate social responsibility in the area of environmental protection is essential. First, the article examines the theoretical framework of social responsibility and environmental protection issues in the social responsibility of enterprises. Second, the article considers the implementation of corporate social responsibility for environmental protection of the businesses in Vietnam through the statistics. The article also points out the causes and consequences of this situation. Finally, the article provides some key solutions to make the implementation of environmental policies more effective in reality. DOI: 10.5901/jesr.2015.v5n3p3

THE EFFECTIVENESS OF EXPERIENTIAL LEARNING MODELS IN TEACHER TRAINING: A CASE STUDY IN THAI NGUYEN PROVINCE, VIETNAM

The quality of education may be raised in large part by investing in teacher training. It contributes to the expansion and updating of professional knowledge, teaching abilities, and new and improved methods of approaching students. Teachers can also continue to grow individually via the refresher process, reflect on their teaching methods, and adjust to shifts in the educational landscape and the needs of their students. The purpose of the project is to identify an experiential learning-based teacher training paradigm that is efficient and workable. A pedagogical experiment using this model was conducted with two classes and 35 high school teachers in Thai Nguyen Province, Vietnam. The findings of the research, which used the document research approach together with expert opinion, demonstrate that learning via experience in teacher training has accomplished the desired objective in 5 key stages: (1) (1) Choosing a few standard lessons to organize to teach illustrations; (2) preparing to organize the illustration teaching after the standard lesson has been chosen; (3) practicing demonstration teaching; (4) organizing the discussion after attending the demonstration lesson; and (5) making personal plans to organize the lesson in accordance with the training's content.  Article visualizations

Payment Methods in Acquisitions of Association of Southeast Asian Nations Bidders

This paper examines the determinants of methods of payment in M&A transactions in ASEAN countries. We take into account the effects of characteristics of bidders, targets and countries on the choice of method of payment. The findings document the importance of bidders' technology status, targets' ownership status, relative size of bidders and targets, and especially the corporate governance variables in the countries that involved in those M&A transactions. In addition, crisis periods also distinguish the choices of payment method for domestic and cross-border M&As in ASEAN countries. Keywords: Methods of payment, ASEAN countries, Mergers, Acquisitions JEL Classifications: G32, G34, G3

TÌNH HÌNH Ô NHIỄM DẦU TRONG NƯỚC DẢI VEN BỜ VIỆT NAM

Các kết quả quan trắc về nồng độ dầu trong nước dải ven biển Việt Nam trong hơn 10 năm qua cho thấy nước biển đã bị ô nhiễm bởi dầu và mức độ ô nhiễm ngày càng gia tăng. Các nguyên nhân gây ô nhiễm dầu trong nước bao gồm quá trình khai thác dầu trong thềm lục địa, quá trình chế biến dầu tại các cơ sở lọc dầu ven biển, hoạt động của hệ thống cảng biển trong vùng nước ven bờ, các sự cố tràn dầu, tai nạn hàng hải. Các cuộc khảo sát mới nhất năm 2009 - 2010 tại 4 khu vực trọng điểm là Hạ Long, Tam Giang - Cầu Hai, Vũng Tàu và Phú Quốc cũng cho thấy sự gia tăng của nồng độ dầu trong nước biển. Điều này cho thấy cần thiết phải kiểm soát các nguồn thải dầu mỡ trên vùng biển nhằm góp phần giữ gìn chất lượng môi trường, bảo vệ nguồn tài nguyên biển và đa dạng sinh học

TÍNH TOÁN KHẢ NĂNG TIẾP NHẬN CHẤT Ô NHIỄM CỦA ĐẦM THỊ NẠI (TỈNH BÌNH ĐỊNH)

Based on the surveys at Thi Nai lagoon in rainy season (October, 2013) and dry season (May, 2014) and the documents on natural conditions, socio-economic status of Thi Nai lagoon, receiving capacity of pollutants in the lagoon was calculated on the basis of environmental standards, using Delft3D model. Calculation results showed that at present Thi Nai lagoon no longer has capacity to receive ammonium and nitrate. Until 2025, besides two parameters, Thi Nai lagoon will no longer have capacity to receive phosphate. In addition, the receiving capacity of the lagoon will be reduced for most of parameters while receiving capacity of lagoon for BOD5 and TSS will increase. Regarding heavy metals, receiving capacity of lagoon will be reduced, especially for Zn (12.18%).Dựa trên các số liệu khảo sát về chất lượng nước tại đầm Thị Nại mùa mưa (tháng 10/2013) và mùa khô (tháng 5/2014), các tài liệu thu thập về điều kiện tự nhiên, kinh tế - xã hội ven đầm và các tiêu chuẩn môi trường, đã tính toán khả năng tiếp nhận các chất ô nhiễm trong đầm thông qua sử dụng mô hình Delft3D. Kết quả tính cho thấy, hiện tại đầm Thị Nại không còn khả năng tiếp nhận amoni, nitrat. Tới năm 2025, ngoài 2 thông số này đầm Thị Nại sẽ không còn khả năng tiếp nhận phosphat. Ngoài ra, khả năng tiếp nhận của đầm sẽ giảm đi đối với hầu hết các thông số (3,44%, 1,84%, 0,02%, 12,18%, 0,46% đối với COD, Cu, Pb, Zn và As, tương ứng), trong khi khả năng tiếp nhận BOD5 và vật lơ lửng tăng lên. Liên quan đến các kim loại nặng, khả năng tiếp nhận của đầm cũng giảm đi nhiều nhất là Zn (12,18%)