Growth and morphological responses of Halophila beccarii to low salinity

Halophila beccarii Ascherson is classified as a threatened seagrass species by IUCN because of the reductive tendency of ​​its distribution area. This seagrass is considered a euryhaline species adapted to a wide range of salinities from freshwater and brackish water to marine water. Previous studies showed that the species tends to grow better under low salinity; however, its optimum salinity has not been determined. In Vietnam, H. beccarii grows in habitats with low salinity (0–20 ppt). The results show that salinity affects the growth, survival rate, shoot density, biomass, and morphological characteristics of the grass. The leaf dimension is more prolonged and broader; the petiole and shoot length are longer at 10 ppt salinity. In contrast, both the number of shoots and biomass peak at 5 ppt and decrease at lower and higher salinities. The study reveals that H. beccarii can grow better under mesohaline conditions than freshwater and hypersaline conditions with an optimum salinity at 5–10 ppt. These findings would explain the species’ distribution dynamics in coastal environments and be helpful information for conserving the seagrass populations in habitats with fluctuating salinity as coastal lagoons in Central Vietnam

Miliutine A acid, a new cyclofarnesane sesquiterpene from the stems of <i>Miliusa velutina</i>

Six compounds were isolated from the ethyl acetate extract of the stems of Miliusa velutina, including miliutine A acid (1), a new cyclofarnesane sesquiterpenoid; miliutine B methyl ester (2), a cyclofarnesane sesquiterpenoid which was determined the absolute configuration for the first time and four known phenol derivatives (3–6). NMR spectroscopic and mass spectrometry were used for identifying relative configurations. The assignments of the absolute configurations were determined based on Electronic Circular Dichroism (ECD) and NOESY spectra analysis. All six compounds were screened for their in vitro cytotoxic activities against HepG2 cell line using the SRB assay and they showed weak or none activities.</p

Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions

Deterministic compressive sampling for high-quality image reconstruction of ultrasound tomography

Abstract Background A well-known diagnostic imaging modality, termed ultrasound tomography, was quickly developed for the detection of very small tumors whose sizes are smaller than the wavelength of the incident pressure wave without ionizing radiation, compared to the current gold-standard X-ray mammography. Based on inverse scattering technique, ultrasound tomography uses some material properties such as sound contrast or attenuation to detect small targets. The Distorted Born Iterative Method (DBIM) based on first-order Born approximation is an efficient diffraction tomography approach. One of the challenges for a high quality reconstruction is to obtain many measurements from the number of transmitters and receivers. Given the fact that biomedical images are often sparse, the compressed sensing (CS) technique could be therefore effectively applied to ultrasound tomography by reducing the number of transmitters and receivers, while maintaining a high quality of image reconstruction. Methods There are currently several work on CS that dispose randomly distributed locations for the measurement system. However, this random configuration is relatively difficult to implement in practice. Instead of it, we should adopt a methodology that helps determine the locations of measurement devices in a deterministic way. For this, we develop the novel DCS-DBIM algorithm that is highly applicable in practice. Inspired of the exploitation of the deterministic compressed sensing technique (DCS) introduced by the authors few years ago with the image reconstruction process implemented using l 1 regularization. Results Simulation results of the proposed approach have demonstrated its high performance, with the normalized error approximately 90% reduced, compared to the conventional approach, this new approach can save half of number of measurements and only uses two iterations. Universal image quality index is also evaluated in order to prove the efficiency of the proposed approach. Conclusions Numerical simulation results indicate that CS and DCS techniques offer equivalent image reconstruction quality with simpler practical implementation. It would be a very promising approach in practical applications of modern biomedical imaging technology

ĐO LƯỜNG HIỆU QUẢ CỦA CÁC NGÂN HÀNG THƯƠNG MẠI TRÊN ĐỊA BÀN TỈNH THỪA THIÊN HUẾ SỬ DỤNG MÔ HÌNH KẾT HỢP BSC-DEA

The BSC-DEA model is a combination model between two performance measurement methods that are applied commonly at present: balanced scorecard (BSC) and data envelopment analysis (DEA). It is considered a reasonable model to measure efficiency of non-manufacturing organizations such as commercial banks, which use many inputs to produce a lot of outputs. This is because such a model can allow us not only to compare the relative efficiency between different banks but also to evaluate the performance of each bank on four perspectives: financial, customer, internal processes, learning and growth. Therefore, our study has applied this integrated model to measure the efficiency of commercial banks in Thua Thien Hue province. The results show that the customer perspective has the lowest average technical efficiency score; so the commercial banks in the area need to consider improving the efficiency of this aspect by expanding their scale and developing their new customers.Mô hình BSC-DEA là mô hình kết hợp giữa hai phương pháp đo lường hiệu quả đang được áp dụng phổ biến hiện nay là: thẻ điểm cân bằng (BSC) và phân tích bao dữ liệu (DEA). Đây được xem là mô hình hợp lý để đo lường hiệu quả của các tổ chức phi sản xuất, sử dụng nhiều đầu vào để tạo ra nhiều đầu ra như các NHTM. Phương pháp này không chỉ cho phép so sánh hiệu quả tương quan giữa các ngân hàng khác nhau mà còn cho phép đánh giá hiệu quả của mỗi ngân hàng trên cả bốn phương diện: tài chính, khách hàng, quy trình nội bộ, học hỏi và phát triển. Vì vậy, nghiên cứu của chúng tôi đã sử dụng mô hình kết hợp này để đo lường hiệu quả hoạt động của các NHTM trên địa bàn tỉnh Thừa Thiên Huế. Kết quả cho thấy phương diện khách hàng là phương diện có chỉ số hiệu quả kỹ thuật bình quân thấp nhất; các NHTM trên địa bàn cần xem xét cải thiện hiệu quả của phương diện này thông qua mở rộng quy mô, phát triển thêm khách hàng mới

Utilisation agricole de plantes aquatiques, notamment en tant qu'amendement des sols, dans la province de Thua Thien Hue, Centre Vietnam. 1. Inventaire, abondance et caractérisation chimique des plantes aquatiques disponibles localement.

Une pratique empirique fréquente au Centre Vietnam est d’utiliser des plantes aquatiques à diverses fins, et notamment en tant qu’amendement des sols. Cette pratique contribue à augmenter les entrées de matière organique dans les systèmes de production, ce qui est particulièrement crucial dans les zones sableuses où les sols sont intrinsèquement peu fertiles. Dans la province de Thua Thien Hue, la grande lagune de Tam Giang (22.000 ha) constitue une source potentiellement très importante de biomasse exogène pour l’agriculture. La présente étude dresse un inventaire des macrophytes submergés et des algues de la lagune durant la période février-avril 2005. Douze espèces de macrophytes appartenant aux familles des Potamogetonaceae, Najadaceae, Cymodoceaceae, Hydrocharitaceae, Ceratophyllaceae et Haloragaceae, et 5 espèces d’algues appartenant aux familles des Ulvaceae, Cladophoraceae, Characeae et Gracilariaceae ont été identifiées. Leur abondance varie fortement en fonction de l’espèce et de la position dans la lagune qui conditionne le niveau de salinité, la profondeur et le type de sédiments dans lequel s’ancrent les macrophytes. Les biomasses fraîches les plus importantes pour des tapis végétaux monospécifiques ont été relevées pour Vallisneria spiralis (3,1 kg.m-2), Najas indica (2,9 k.m-2), Halodule tridentata (2,5 kg.m-2) et Cymodoceae rotundata (2,3 kg.m-2). Toutes les plantes ont été collectées selon les techniques des agriculteurs et leur composition chimique a été déterminée. Pour les macrophytes, les gammes de teneurs suivantes ont été mesurées (en % de la matière sèche): N 1,0 à 3,5; P 0,08 à 0,45; K 1,0 à 4,2;Mg0,3à1,4;Ca0,7à2,8;Na0,7à7,6;cequimet en évidence des valeurs fertilisantes potentielles très différentes selon les espèces. Les algues présentent des teneurs encore plus contrastées selon les espèces pour la plupart de ces éléments. La teneur en Na est partiellement expliquée par le niveau de salinité du lieu de prélèvement