Ecpoc: an evolutionary computation-based proof of criteria consensus protocol

Recently, blockchain technology has been applied in many domains in our life. Blockchain networks typically utilize a consensus protocol to achieve consistency among network nodes in a decentralized environment. Delegated Proof of Stake (DPoS) is a popular mechanism adopted in many networks such as BitShares, EOS, and Cardano because of its speed and scalability advantages. However, votes that come from nodes on a DPoS network tend to support a set of specific nodes that have a greater chance of becoming block producers after voting rounds. Therefore, only a small group of nodes can be selected to become block producers. To address this issue, we propose a new protocol called Evolutionary Computation-based Proof of Criteria (ECPoC), which uses ten criteria to evaluate and select a new block procedure in each round. Next, a set of optimal weights used for maximizing the network’s decentralization level is identified through the use of evolutionary computation algorithms. The experimental results show that our consensus significantly enhances the degree of decentralization in the selection process of witness nodes compared to DPoS. As a result, ECPoC facilitates fairness between nodes and creates momentum for blockchain network developmen

GHI NHẬN ĐẦU TIÊN VỀ ĐỘC TÍNH CỦA LOÀI VI KHUẨN LAM PLANKTOHRIX RUBESCENS PHÂN LẬP TỪ AO NUÔI CÁ TỈNH SÓC TRĂNG

Cyanobacteria and their toxicity are of environmental quality and ecological health concerns. This study aimed to determine the toxicity of the cyanobacterium Planktothrix rubescens from Vietnam. The cyanobaccterial samples from a fish pond in Soc Trang province were collected and brought to the laboratory for morphological species indentification and isolation for culture. The extracts of the cyanobacterium, P. rubescens, were used for microcystins characterization and toxicity testing on a micro-crustacean, Daphnia magna. The results contributed the first photos and morphological description on the cyanobacterium P. rubescens from Vietnam. The Enzyme Linked Immunoabsorbent Assay (ELISA) analysis indicated that all five strains of P. rubescens could produce microcystins at the concentrations of 0.06-0.42 µg/g dried weight. The chronic exposure of D. magna to the extract of P. rubescens, strain S1, revealed that the survival of the animal was strongly reduced. The toxicity of the extract to D. magna showed that there should be toxic sencondary metabolites other than microcystins in the extract. This study contributed the scientific information on the biodiversity and toxicity of cyanobacteria from Vietnam.Vi khuẩn lam và độc tính của nó là một trong những mối quan ngại liên quan đến chất lượng môi trường và sức khỏe sinh thái. Nghiên cứu này nhằm mục tiêu xác định độc tính của loài vi khuẩn lam Planktothrix rubescens có nguồn gốc Việt Nam. Mẫu vi khuẩn lam trong ao nuôi cá ở tỉnh Sóc Trăng được thu và mang về phòng thí nghiệm phục vụ việc định danh trên cơ sở hình thái học và phân lập để nuôi lấy sinh khối. Dịch chiết của loài P. rubescens được dùng để phân tích độc tố microcystins và dùng để thử nghiệm độc tính trên loài vi giáp xác Daphnia magna. Kết quả nghiên cứu đã đóng góp hình ảnh và mô tả hình thái đầu tiên cho loài vi khuẩn lam P. rubescens có nguồn gốc Việt Nam. Phân tích bằng ELISA (Enzyme Linked Immunoabsorbent Assay) đã cho thấy cả 5 chủng thuộc loài P. rubescens đều có thể 3 sản sinh độc tố microcystins với nồng độ từ 0,06 – 0,42 µg/g trọng lượng khô. Phơi nhiễm mãn tính D. magna với dịch chiết của P. rubescens, chủng S1, được quan sát và sức sống của sinh vật bị suy giảm đáng kể. Độc tính của dịch chiết đối với D. magna cho thấy trong dịch chiết ắt hẳn có chứa hợp chất thứ cấp khác có độc đối với vi giáp xác. Nghiên cứu này đóng góp thêm thông tin khoa học về đa dạng sinh học và độc học sinh thái của VKL có nguồn gốc Việt Na

chemical constituents from methanolic extract of Garcinia mackeaniana leaves and their antioxidant activity

A phytochemical investigation of the methanolic extract of Garcinia mackeaniana leaves led to the isolation, and determination of five secondary metabolites, including one benzophenone 4,3',4'-trihydroxy-2,6-dimethoxybenzophenone (1), two flavone C-glucosides vitexin (2) and its 2''-O-acetyl derivative (3), one biflavone amentoflavone (4), and one mono-phenol methyl protocatechuate (5). The chemical structures of these compounds were characterized by the NMR-spectroscopic method. These isolated compounds were isolated from G. mackeaniana species for the first time. Benzophenone derivative 1 has shown to be associated with a significant IC50 value of 14.97±0.8 µg/mL in the DPPH-antioxidant assay

Cytotoxic naphthoquinones from Diospyros fleuryana leaves

In the search for anti-cancer plants in Vietnam, the leaves of Diospyros fleuryana were selected for chemical investigation. Phytochemical analysis of the ethyl acetate (EtOAc) extract led to the isolation of two naphthoquinones isodiospyrin (1), and 8'-hydroxyisodiospyrin (2), and one isoflavone 7-O-methylbiochanin A (3). The chemical structures of isolated compounds were determined by 1D-NMR (1H, and 13C-NMR), 2D-NMR spectra (HSQC, and HMBC), and MS spectroscopy. Compound 3 was isolated from genus Diospyros for the first time. Regarding the strong IC50 values of 2.27, and 8.0 µM against KB, and Hep cell lines respectively, cytotoxic examination suggested that compound 2 is a promising agent in anti-cancer treatment.Â

The results of deep magnetotelluric sounding for studying the Nha Trang - Tanh Linh fault

The profile of deep magnetotelluric sounding (MT) from Duc Trong - Tuy Phong has been carried out in Lam Dong and Binh Thuan  provinces. The length of the Duc Trong - Tuy Phong profile is about 80 km with 15 stations and the distance between the stations measures about 5 km. Two-dimensional MT inversion was used to find a resistivity model that fits the data. The 2D resistivity model allows determining position and development formation of the Nha Trang - Tanh Linh  fault. This is the deep fault, which is showed by the boundaries of remarkable change of resistivity. In the near surface of the Earth (from ground to the depth of 6 km), the angle of inclination of this fault is about 60o; in the next part, the direction of the Nha Trang - Tanh Linh  faut is vertical. Geoelectrical section of the Nha Trang - Tanh Linh  profile shows that the resistivity of mid-crust is higher than that of lower-crust and of upper-crust

ỨNG DỤNG CÔNG NGHỆ VIỄN THÁM VÀ GIS NGHIÊN CỨU QUÁ TRÌNH DỊCH CHUYỂN ĐƯỜNG BỜ VÀ ĐÓNG/MỞ CỬA ĐẦM Ô LOAN (PHÚ YÊN) GIAI ĐOẠN 1965 - 2014

Application of remote sensing and GIS (Geographic Information System) technologies found that: Fluctuation process of shoreline in O Loan lagoon became evident, through which a general picture of the shoreline development in a long time from 1965 - 2014 has been launched. The process of erosion - accretion evolutions occurred time by time. In which, the period from 1965 - 1995 was the process of erosion - accretion and gradual northward movement of O Loan lagoon inlet, with erosion area greater than deposition area. The period after 1995 was the process of erosion and An Hai inlet opening during rainy season, coincident with northeast monsoon and typhoon activity; and the process of accretion and An Hai inlet closing during dry season, coincident with southwest monsoon.Trên cơ sở ứng dụng công nghệ viễn thám và GIS (hệ thông tin địa lý) cho thấy: Quá trình biến động của đường bờ biển khu vực đầm Ô Loan được thể hiện rõ rệt, qua đó đã đưa ra bức tranh tổng quát về quá trình phát triển của đường bờ, trong một thời gian dài từ năm 1965 - 2014. Các quá trình xói lở - bồi tụ diễn biến theo thời gian. Trong đó, thời kỳ từ năm 1965 - 1995 là các quá trình xói lở - bồi tụ và dịch chuyển cửa biển đầm Ô Loan dần lên phía bắc, với diện tích bị xói lở lớn hơn diện tích được bồi tụ. Thời kỳ từ sau năm 1995 đến nay là quá trình xói lở và mở cửa biển An Hải chủ yếu xảy ra vào mùa mưa, trùng với thời kỳ gió mùa Đông Bắc và bão hoạt động, còn bồi lấp cửa biển xảy ra vào mùa khô, trùng với thời kỳ gió mùa Tây Nam

Composted tobacco waste increases the yield and organoleptic quality of leaf mustard

Tobacco (Nicotiana tabacum) waste is produced in many countries and is phytotoxic due to the alkaloid content; in Vietnam the waste is usually burned causing air pollution. We composted tobacco waste with chicken manure in different proportions—1 t of waste ± accelerant (C1 and C2); 0.8 t of waste + 0.2 t of chicken manure ± accelerant (C3 and C4); and 0.7 t of waste + 0.3 t of chicken manure ± accelerant (C5 and C6)—for 30 d in covered heaps. Three mixtures containing the accelerant (C2, C4, and C6) reached temperatures of ∼55 °C, that 5s, hot enough to suppress disease and weeds. Composting decreased the alkaloid content from ∼6,000 to ∼200 mg kg−1, and C4 with a C/N ratio of 19:1, was used in a field trial. The compost treatments (0, 10, 15, and 20 t ha−1) were combined fertilizer with phosphorus (40 kg ha−1), nitrogen (60 kg ha−1) and potassium (90 kg ha−1) for leaf mustard (Brassica integrifolia). The yield increased from ∼17 to ∼29 t ha−1 with the amount of compost applied, and the nitrate concentration decreased concomitantly from ∼67 to ∼42 mg NO3–N kg−1 fresh weight, presumably due to ongoing composting (nitrogen drawdown). Organoleptic evaluation showed a preference for the crops grown with the compost amendments. Whether remains to be seen whether one-off compost applications >20 t ha−1 and repeated, large applications provide additional, long-term production benefits, or if the benefits may be outweighed by the accumulation of persistent, phytotoxic alkaloids

Assessment of the Effectiveness of Ich Tam Khang as a Supportive Therapy for Chronic Heart Failure

Background: Heart failure is a chronic disease needing lifelong management. Despite the advances that have been made in the treatment of the disease, both the longevity and quality of life for those with chronic heart failure remain impaired. A more effective therapeutic approach with less negative side effects is still needed. In this study, we evaluate Ich Tam Khang (ITK), the poly-ingredient herbal and nutritional preparation with multiple physiological actions, as a supportive therapy for patients with chronic heart failure.Aims of Study: To evaluate the effectiveness and safety of Ich Tam Khang as an adjunctive treatment of chronic heart failure.Methods: A total of 60 patients with chronic congestive heart failure were enrolled in this open label, cross-sectional and prospective study. All patients were treated with a conventional regimen (digoxin, diuretics, angiotensin-converting-enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs), beta blockers) for at least 4 weeks before being divided into two equal groups. In the treated patients with ITK, patients received conventional therapy plus 4 tablets ITK per day added in two divided doses. In the control patients, all patients kept the same conventional regimen without ITK. All patients were followed up for 3 months for clinical and para-clinical outcomes.Result: The symptoms of heart failure (dyspnea, palpitation, peripheral edema, neck vein distention, heptojugular reflex) decreased. Heart rate and blood pressure stabilized during treatment in the treated patients with ITK. Additionally, total cholesterol and HDL-cholesterol normalized in the patients treated with ITK. Most of echocardiography parameters in the ITK treated patients were superior to the control patients. ITK is safe and it has no side effects.Conclusion: ITK as a combination of herbal and nutritional preparation is effective in reducing heart failure symptoms, improving patient's quality of life for the patients with decompensated heart failure and reducing total cholesterol and LDL-C

CAMELLIA SINENSIS VAR. MADOENSIS (SECT. THEA, THEACEAE), A NEW TAXON FROM VIETNAM

Camellia sinensis var. madoensis is described and illustrated as a new variety of Camellia sinensis (section Thea, Theaceae) from Xuan Loc Commune, Song Cau District, Phu Yen Province. The new variety is easily distinguishable from C. sinensis var. sinensis by style free ½ to the base. The ITS sequence of this variety is also different from that of Camellia sinensis and its other varieties, while the matK gene sequences are nearly identical among Camellia taxa.Camellia sinensis var. madoensis được mô tả và minh họa với vai trò là một thứ mới của Camellia sinensis (section Thea, Theaceae) ghi nhận tại xã Xuân Lộc, huyện Sông Cầu, tỉnh Phú Yên. Thứ mới này có thể dễ dàng phân biệt với C. sinensis var. sinensis bởi vòi nhụy rời ½ tính từ đế. Trình tự ITS của thứ này cũng khác với Camellia sinensis và các thứ khác của nó

THE EFFECTS OF DRYING TEMPERATURE ON THE STRUCTURE AND CORROSION RESISTANCE OF Cr3+-BASED CONVERSION COATINGS ON ZINC-COATED STEEL SURFACE

In this paper, we present results of drying temperature influence on the structure and corrosion  resistance of  Cr(III)–based conversion coatings on the surface of zinc-coated steel. The results show that the quality of Cr(III)–based conversion coatings is strongly influenced by the drying temperature, the appropriate drying temperature is about 80 oC, and drying at higher temperatures will reduce corrosion resistance durability and raise the cost of the production process