Changes in mangrove vegetation area and character in a war and land use change affected region of Vietnam (Mui Ca Mau) over six decades

Aerial photographs and satellite images have been used to determine land cover changes during the period 1953 to 2011 in the Mui Ca Mau, Vietnam, especially in relation to changes in the mangrove area. The mangrove area declined drastically from approximately 71,345 ha in 1953 to 33,083 ha in 1992, then rose to 46,712 ha in 2011. Loss due to herbicide attacks during the Vietnam War, overexploitation, and conversion into agriculture and aquaculture encouraged by land management policies are being partially counteracted by natural regeneration and replanting, especially a gradual increase in plantations as part of integrated mangrove-shrimp farming systems. The nature of the mangrove vegetation has markedly been transformed over this period. The results are valuable for management planning to understand and improve the contribution of mangrove forests to the provision of ecosystem services and resources, local livelihood and global interest

Mechanism of enhanced photocatalytic activity of Cr-doped ZnO nanoparticles revealed by photoluminescence emission and electron spin resonance

In this work, we successfully synthesized Cr³⁺ doped ZnO nanoparticles using a sol-gel method, and elucidated how Cr³⁺ dopant is critical for enhancing photocatalytic activity. The nature of the point defect analyzed by electron spin resonance (ESR), and photoluminescence (PL) emission revealed the role of the Cr³⁺ dopant. When introducing Cr³⁺ ions in ZnO, the PL emission intensity decreased, indicating a reduction of the radiative recombination rate due to the heterojunction formation between the dopant and the host. The Cr³⁺ doped ZnO nanostructures showed that the typical ESR signal with g-factor value ∼1.96 was completely passivated, indicating the diffusion of electrons near the conduction band into the dopant ions. The doped Cr³⁺ ion acts as an electron trap in the ZnO crystal described as Cr³⁺ + e⁻ → Cr²⁺. The mechanism for enhancing the photocatalytic activity of heterogeneous ZnO:Cr³⁺ was proposed in respect of point defect evolution through the manner of Cr³⁺ doping. As a result, the photocatalytic efficiency investigated by measuring methylene blue degradation under 210 min of direct sunlight irradiation reached 93.5% for 1 at % Cr³⁺ doped ZnO, which was significantly improved compared to 59.8% of the pure ZnO.Nguyen Xuan Sang, Nguyen Minh Quan, Nguyen Huu Tho, Nguyen Tri Tuan, and Tran Thanh Tun

Changes in the spike and nucleocapsid protein of porcine epidemic diarrhea virus strain in Vietnam—a molecular potential for the vaccine development?

Background Porcine epidemic diarrhea virus (PEDV) is a dangerous virus causing large piglet losses. PEDV spread rapidly between pig farms and caused the death of up to 90% of infected piglets. Current vaccines are only partially effective in providing immunity to suckling due to the rapid dissemination and ongoing evolution of PEDV. Methods In this study, the complete genome of a PEDV strain in Vietnam 2018 (IBT/VN/2018 strain) has been sequenced. The nucleotide sequence of each fragment was assembled to build a continuous complete sequence using the DNASTAR program. The complete nucleotide sequences and amino acid sequences of S, N, and ORF3 genes were aligned and analyzed to detect the mutations. Results The full-length genome was determined with 28,031 nucleotides in length which consisted of the 5′UTR, ORF1ab, S protein, ORF3, E protein, M protein, N protein, and 3′UTR region. The phylogenetic analysis showed that the IBT/VN/2018 strain was highly virulent belonged to the G2b subgroup along with the Northern American and Asian S-INDEL strains. Multiple sequence alignment of deduced amino acids revealed numerous mutations in the S, N, and ORF3 regions including one substitution 766P > L766 in the epitope SS6; two in the S0subdomain (135DN136 > 135SI136 and N144> D144); two in subdomain SHR1 at aa 1009L > M1009 and 1089S > L1089; one at aa 1279P > S1279 in subdomain SHR2 of the S protein; two at aa 364N > I364 and 378N > S378 in the N protein; four at aa 25L > S25, 70I > V70, 107C > F107, and 168D > N168 in the ORF3 protein. We identified two insertions (at aa 59NQGV62 and aa 145N) and one deletion (at aa 168DI169) in S protein. Remarkable, eight amino acid substitutions (294I > M294, 318A > S318, 335V > I335, 361A > T361, 497R > T497, 501SH502 > 501IY502, 506I > T506, 682V > I682, and 777P > L777) were found in SA subdomain. Besides, N- and O-glycosylation analysis of S, N, and ORF3 protein reveals three known sites (25G+, 123N+, and 62V+) and three novel sites (144D+, 1009M+, and 1279L+) in the IBT/VN/2018 strain compared with the vaccine strains. Taken together, the results showed that mutations in the S, N, and ORF3 genes can affect receptor specificity, viral pathogenicity, and the ability to evade the host immune system of the IBT/VN/2018 strain. Our results highlight the importance of molecular characterization of field strains of PEDV for the development of an effective vaccine to control PEDV infections in Vietnam

miREM: An expectation-maximization approach for prioritizing miRNAs associated with gene-set

10.1186/s12859-018-2292-1BMC Bioinformatics19129