DYNAMICS OF POPULATIONS DESCRIBED BY A LOTKAVOLTERA EQUATION UNDER RANDOM ENVIRONMENT

Joint Research on Environmental Science and Technology for the Eart

DYNAMICS OF PREDATOR-PREY POPULATION WITH MODIFIED LESLIE-GOWER AND HOLLING-TYPE II SCHEMES

Joint Research on Environmental Science and Technology for the Eart

A data-driven approach for Network Intrusion Detection and Monitoring based on Kernel Null Space

International audienceIn this study, we propose a new approach to determine intrusions of network in real-time based on statistical process control technique and kernel null space method. The training samples in a class are mapped to a single point using the Kernel Null Foley-Sammon Transform. The Novelty Score are computed from testing samples in order to determine the threshold for the real-time detection of anomaly. The efficiency of the proposed method is illustrated over the KDD99 data set. The experimental results show that our new method outperforms the OCSVM and the original Kernel Null Space method by 1.53% and 3.86% respectively in terms of accuracy

Robust stability of differential-algebraic equations

This paper presents a survey of recent results on the robust stability analysis and the distance to instability for linear time-invariant and time-varying differential-algebraic equations (DAEs). Different stability concepts such as exponential and asymptotic stability are studied and their robustness is analyzed under general as well as restricted sets of real or complex perturbations. Formulas for the distances are presented whenever these are available and the continuity of the distances in terms of the data is discussed. Some open problems and challenges are indicated

Stability and robust stability of linear time-invariant delay differential-algebraic equations

Necessary and sufficient conditions for exponential stability of linear time invariant delay differential-algebraic equations (DDAEs) are presented. The robustness of this property is studied when the equation is subjected to structured perturbations and a computable formula for the structured stability radius is derived. The results are illustrated by several examples

NGHIÊN CỨU VI SINH VẬT SỐNG CÙNG MỘT SỐ LOÀI SAN HÔ CỨNG TẠI HANG RÁI NINH THUẬN BẰNG PHƯƠNG PHÁP NHUỘM HUỲNH QUANG KẾT HỢP NUÔI CẤY TỚI HẠN

Coral associated bacteria and their host are currently one of the interested issues for research and scientists worldwide. The densities of zooxanthellae and bacteria associated with three most prevalent species Acropora hyacinthus, Acropora muricata and Acropora robusta in Hang Rai, Ninh Thuan was evaluated over time by staining with SYBR Gold and direct counting with epifluorescence method. The most dominant bacteria were isolated by culture dependent method. The densities of zooxanthellae and bacteria ranged from 0.39–1.83×107 cell/g, and 0.83–2.52×108 cell/g, respectively. Bacterial density in the 3 months was significantly different compared to the density of the bacteria in ambient water. Total heterotrophic bacteria, comma shaped bacteria and bacillus form showed negatively correlated with pH, PO4, while zooxanthellae showed no correlation with all factors.Rạn san hô trên toàn thế đang đối mặt với sự huỷ diệt nghiêm trọng, một trong những nguyên nhân chính là do vi khuẩn gây bệnh và những tác động của môi trường. Chính vì vậy, nghiên cứu về hệ vi khuẩn sống cùng san hô và mối tương quan giừa vi khuẩn, san hô và các yếu tố môi trường là quan trọng và cấp thiết. Trong nghiên cứu này, mật độ vi tảo Symbiodinium sp., vi khuẩn sống cùng 3 loài san hô cứng Acropora hyacinthus, Acropora muricata và Acropora robusta phổ biến tại Ninh Thuận được đánh giá vào các thời điểm trước, trong, và sau khi san hô bị tẩy trắng bằng phương pháp đếm huỳnh quang và pha loãng tới hạn. Kết quả cho thấy mật độ tảo Symbiodinium khác nhau có ý nghĩa thống kê (dao động 0,39-1,83x107tb/g) ở các loài san hô khác nhau. Tuy nhiên, mật độ tảo cộng sinh không có khác biệt lớn giữa các tháng nghiên cứu. Mật độ vi khuẩn dao động từ 0,83-2,52x108tb/g và có sự sai khác có ý nghĩa thống kê không chỉ giữa các loài san hô mà còn ở các thời điểm trước trong và sau tẩy trắng. Tổng vi khuẩn, phẩy khuẩn và trực khuẩn có tương quan nghịch và có ý nghĩa về mặt thống kê với chỉ số pH và hàm lượng PO4. Ngược lại, mật độ tảo hoàn toàn không tương quan với các yếu tố môi trường

PSSA- INTERNATIONAL SOLUTION TO PROTECT THE BIODIVERSITY IN HA LONG BAY - CAT BA MARINE AREA

A Particularly Sensitive Sea Area (PSSA) is an important management tool for biodiversity protection of a marine area. At the time of designation of a Particularly Sensitive Sea Area, an associated protective measure, which meets the requirements of the appropriate legal instrument establishing such measure, must have been approved or adopted by IMO to prevent, reduce, or eliminate the threat or identified vulnerability. Information on each of the Particularly Sensitive Sea Areas (PSSAs) that has been designated by IMO is available on the nautical chart. The Vietnam’s coastal zones and islands are the isolated oceanic habitat of extremely rich marine life in very good condition which is important to the maintenance and dispersal of the marine life of the western tropical Pacific. Vietnam coastal areas are very high risk areas affected by maritime activities, particularly international shipping, therefore in the future identification of some Particularly Sensitive Sea Areas (PSSAs) is necessary. The first Particularly Sensitive Sea Area for Vietnam in Ha Long - Cat Ba was initially proposed in this paper

A Bayesian approach to quantifying the effects of mass poultry vaccination upon the spatial and temporal dynamics of H5N1 in Northern Vietnam.

Published versio

Modelling the progression of pandemic influenza A (H1N1) in Vietnam and the opportunities for reassortment with other influenza viruses

BACKGROUND: A novel variant of influenza A (H1N1) is causing a pandemic and, although the illness is usually mild, there are concerns that its virulence could change through reassortment with other influenza viruses. This is of greater concern in parts of Southeast Asia, where the population density is high, influenza is less seasonal, human-animal contact is common and avian influenza is still endemic. METHODS: We developed an age- and spatially-structured mathematical model in order to estimate the potential impact of pandemic H1N1 in Vietnam and the opportunities for reassortment with animal influenza viruses. The model tracks human infection among domestic animal owners and non-owners and also estimates the numbers of animals may be exposed to infected humans. RESULTS: In the absence of effective interventions, the model predicts that the introduction of pandemic H1N1 will result in an epidemic that spreads to half of Vietnam's provinces within 57 days (interquartile range (IQR): 45-86.5) and peaks 81 days after introduction (IQR: 62.5-121 days). For the current published range of the 2009 H1N1 influenza's basic reproductive number (1.2-3.1), we estimate a median of 410,000 cases among swine owners (IQR: 220,000-670,000) with 460,000 exposed swine (IQR: 260,000-740,000), 350,000 cases among chicken owners (IQR: 170,000-630,000) with 3.7 million exposed chickens (IQR: 1.9 M-6.4 M), and 51,000 cases among duck owners (IQR: 24,000 - 96,000), with 1.2 million exposed ducks (IQR: 0.6 M-2.1 M). The median number of overall human infections in Vietnam for this range of the basic reproductive number is 6.4 million (IQR: 4.4 M-8.0 M). CONCLUSION: It is likely that, in the absence of effective interventions, the introduction of a novel H1N1 into a densely populated country such as Vietnam will result in a widespread epidemic. A large epidemic in a country with intense human-animal interaction and continued co-circulation of other seasonal and avian viruses would provide substantial opportunities for H1N1 to acquire new genes