Polyamorphism and Two State Model in Liquid GeO2_{2} under Compression: Insight from Visualization of Molecular Dynamics Data

The polyamorphism and two-state model based on the coordination number distribution in liquid GeO$_{2}$ at 3200~K and in a wide pressure range are investigated by molecular dynamics simulation. Results show that the structure of liquid GeO$_{2}$ mainly consists of GeO$_{x}$ coordination units $(x=4,5,6)$ and OGe$_{y}$ linkages $(y=2, 3)$. The distribution of OGe$_{y}$ linkages in network structure is not uniform but tends to form clusters of OGe$_{y}$. The cluster of OGe$_{2}$ will form low-density phase region, conversely the cluster of OGe$_{3}$ will form high-density phase region. In other word, under compression, in the liquid GeO$_{2}$ coexist two states: low-density and high-density. The size of phase regions significantly depends on compression

ASSESSMENT OF THE POTENTIAL FOR DEVELOPMENT OF AGRITOURISM IN BINH DINH PROVINCE, VIETNAM

This study evaluates the potential for agritourism development in Binh Dinh Province, Central Vietnam. The analytical hierarchical process is used to determine the weights of four factors with 25 measurement criteria to assess agritourism potential. The research results show that Binh Dinh Province has great agritourism potential based on four evaluation factors, including (1) local agricultural tourism resources, (2) the trend for agritourism development and the agritourism market, (3) the local community’s willingness, and (4) the supporting activities of the local government. In particular, the local agricultural tourism resources factor received the highest score, followed by the local community’s willingness and the supporting activities of the local government. The trend for agritourism development and the agritourism market was rated the lowest. Therefore, Binh Dinh has viable opportunities to encourage the growth of agritourism to improve farmers’ livelihoodsDu lịch nông nghiệp đem lại nhiều cơ hội cho phát triển kinh tế cũng như đa dạng hóa các loại hình du lịch và cải thiện đời sống sinh kế của người dân. Nghiên cứu sử dụng phương pháp phân tích thứ bậc (AHP) để tính các trọng số của các tiêu chí đánh giá tiềm năng phát triển du lịch nông nghiệp tại các huyện, thị xã phía bắc tỉnh Bình Định. Tiếp theo, kết quả mô hình hóa sơ đồ mạng cho thấy cả 4 địa phương An Lão, Hoài Ân, Phù Mỹ, thị xã Hoài Nhơn đều được đánh giá ở mức điểm cao về tiềm năng phát triển du lịch nông nghiệp trên các khía cạnh tài nguyên du lịch, xu hướng phát triển du lịch, sự ủng hộ của người dân địa phương và sự quan tâm của chính quyền địa phương. Tuy nhiên, yếu tố xu hướng phát triển thị trường du lịch nông nghiệp được đánh giá ở mức điểm thấp hơn. Điều này cũng xuất phát từ việc phát triển du lịch nông nghiệp tại các huyện, thị xã phía Bắc tỉnh Bình Định cũng mới bắt đầu nhận được sự quan tâm trong vài năm gần đây, số lượt khách tham quan các huyện, thị xã phía Bắc tỉnh Bình Định còn ít so với tiềm năng du lịch của địa bàn

Hybrid OFDM RoF-Based WDM-PON/MMW Backhaul Architecture For Heterogeneous Wireless Networks

In this paper, a hybrid backhaul architecture, which is based on wavelength-division multiplexing passive optical networks (WDM-PON) and millimeter-wave (MMW) communications, is proposed to deliver orthogonal frequency-division multiplexing (OFDM) signals in heterogeneous wireless networks. MMW radio-over-fiber (RoF) technique, which combines the advantages of the both optical fiber and wireless communications, is used to simplify the base stations and provide flexibility long reach and high capacity connections. The feasibility of the proposed hybrid backhaul architecture is investigated via the bit-error rate (BER) performance of a downlink under the impacts of fiber nonlinear, wireless fading and noise components including clipping noise, amplifier noise and photodetector noise. The numerical results obtained from this study help to determine the optimum system parameters such as the optical launched power, modulation index, and amplifier gain so as to minimize the link’s BER

Costing analysis of national HIV treatment and care program in Vietnam

The study found that HIV treatment and care costs in Vietnam are economical, yet there is potential to further promote efficiency through strengthening competitive procurement, integrating HIV services, and promoting earlier antiretroviral therapy (ART) initiation. Non-antiretroviral (ARV) costs in adults at stand-alone facilities were 44% (first year ART) and 24% (later year ART) higher than those at integrated facilities. As well, early treatment before patients’ progress to advanced immunodeficiency will prevent an increase in new HIV infections, while decreasing need for ART in the future. This study provides a first-ever evidence base for nationwide HIV treatment and care costs in Vietnam

Age-time-specific transmission of hand-foot-and-mouth disease enterovirus serotypes in Vietnam: a catalytic model with maternal immunity

Hand, foot and mouth disease (HFMD) is highly prevalent in the Asia Pacific region, particularly in Vietnam. To develop effective interventions and efficient vaccination programs, we inferred the age-time-specific transmission patterns of HFMD serotypes enterovirus A71 (EV-A71), coxsackievirus A6 (CV-A6), coxsackievirus A10 (CV-A10), coxsackievirus A16 (CV-A16) in Ho Chi Minh City, Vietnam from a case data collected during 2013–2018 and a serological survey data collected in 2015 and 2017. We proposed a catalytic model framework with good adaptability to incorporate maternal immunity using various mathematical functions. Our results indicate the high-level transmission of CV-A6 and CV-A10 which is not obvious in the case data, due to the variation of disease severity across serotypes. Our results provide statistical evidence supporting the strong association between severe illness and CV-A6 and EV-A71 infections. The HFMD dynamic pattern presents a cyclical pattern with large outbreaks followed by a decline in subsequent years. Additionally, we identify the age group with highest risk of infection as 1-2 years and emphasise the risk of future outbreaks as over 50% of children aged 6-7 years were estimated to be susceptible to CV-A16 and EV-A71. Our study highlights the importance of multivalent vaccines and active surveillance for different serotypes, supports early vaccination prior to 1 year old, and points out the potential utility for vaccinating children older than 5 years old in Vietnam

Selecting phosphorus-solubilizing strains of purple nonsulfur bacteria isolated from pineapple cultivated acid sulfate soils

The presence of acid sulfate soils is such an obstacle for pineapple cultivation in Vietnam due to their low pH, high toxicity and poor nutrient availability, especially phosphorus (P), which is immobilized by cations in the soils. Therefore, the study occurred to select purple nonsulfur bacteria (PNSB) strains that can solubilize P under toxic and acidic conditions. There were 33 strains that can tolerate the acidic condition, and they were selected and tested for viability and P solubilization under conditions containing Al3+, Fe2+, and Mn2+ toxins. Four strains, including W15, W39, W42 and W48 suffered from growth inhibition by Al3+, Fe2+ and Mn2+ less than the other strains under both microaerobic light and aerobic dark conditions (ML and AD conditions). In addition, there were four strains (W15, W25, W42 and W48) solubilizing Al-P well (21.4-25.2 mg L-1), two strains (W23 and W42) solubilizing Fe-P well (15.9-17.3 mg L-1), and two strains (W17 and W42) solubilizing Ca-P well (23.0-36.4 mg L-1) under both ML and AD conditions. Ultimately, there were five strains selected (W17, W23, W25, W42 and W48) and identified as Rhodopseudomonas palustris strain W17 and W23, Cereibacter sphaeroides strain W23, W42 and W48 based on the 16S rRNA technique. The selected strains also produced ALA, EPS and siderophores at 1.31-2.19 mg L-1, 0.78-1.89 mg L-1, and 16.2-55.6%, respectively. Therefore, these strains were promising in providing nutrients for pineapples in the form of biofertilizer

Feasibility of wearable monitors to detect heart rate variability in children with hand, foot and mouth disease

Hand foot and mouth disease (HFMD) is caused by a variety of enteroviruses, and occurs in large outbreaks in which a small proportion of children deteriorate rapidly with cardiopulmonary failure. Determining which children are likely to deteriorate is difficult and health systems may become overloaded during outbreaks as many children require hospitalization for monitoring. Heart rate variability (HRV) may help distinguish those with more severe diseases but requires simple scalable methods to collect ECG data.We carried out a prospective observational study to examine the feasibility of using wearable devices to measure HRV in 142 children admitted with HFMD at a children's hospital in Vietnam. ECG data were collected in all children. HRV indices calculated were lower in those with enterovirus A71 associated HFMD compared to those with other viral pathogens.HRV analysis collected from wearable devices is feasible in a low and middle income country (LMIC) and may help classify disease severity in HFMD

ĐẶC ĐIỂM SINH HỌC SINH SẢN CỦA NGÁN (AUSTRIELLA CORRUGATA) TẠI VÙNG TRIỀU VEN BIỂN TỈNH QUẢNG NINH

360 samples of mud clam (Austriella corrugata) were collected in the intertidal zone of Quang Ninh province city from January 2015 to December 2015 for this study. The results showed that the gonad of female is black, that of male is milky white. The spawning season is from mid April to early September and the peak of spawning occurs from early June to early August. In spawning season, ratio of male/female is toward balance. In other months, rate of male is dominant in the population. Hermaphroditism occurs in the mud clam with a small percentage (from 3.3% to 10%) in the breeding season, in group with size of more than 40 mm. The length of mud clam at first sexual maturity is over 30 mm and the weight is over 20 g. The average absolute fecundity (Fa) is 960,680 eggs/individual. Development of mud clam larvae goes through main stages: Veliger, Umbo and Spat. Our findings contribute information to the planning of the artificial seed production, conservation and sustainable development of mud clam native resource.Kết quả phân tích 360 mẫu ngán (A. corrugata) thu tại các khu vực nơi có ngán phân bố thuộc vùng triều ven biển tỉnh Quảng Ninh từ tháng 1/2015 đến tháng 12/2015 cho thấy: Tuyến sinh dục ngán đực có màu trắng sữa, ngán cái có màu đen thẫm. Mùa vụ sinh sản của ngán hàng năm được xác định từ giữa tháng 4 đến đầu tháng 9, mùa sinh sản tập trung từ đầu tháng 6 đến đầu tháng 8. Ở các tháng tromg năm, tỷ lệ con đực luôn chiếm ưu thế so với con cái trong quần đàn ngán. Vào mùa sinh sản tỷ lệ đực cái cân bằng. Ngán lưỡng tính xuất hiện với tỷ lệ nhỏ (3,3 - 10%) vào mùa sinh sản và ở nhóm kích thước lớn hơn 40 mm. Ngán thành thục sinh dục lần đầu khi chiều dài đạt trên 30 mm, khối lượng trên 20 g. Sức sinh sản tuyệt đối giao động từ 340.690  - 2.090.000 trứng/cá thể, trung bình đạt 960.680 trứng/cá thể. Ấu trùng của ngán phát triển trải qua các giai đoạn chính: Ấu trùng chữ D, ấu trùng đỉnh vỏ và ấu trùng chân bò. Sau đó, ngán phát triển thành con non. Kết quả nghiên cứu góp phần cung cấp cơ sở khoa học cho việc xây dựng kế hoạch sản xuất giống nhân tạo, bảo vệ và phát triển bền vững nguồn lợi ngán tại địa phương