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This study was conducted to evaluate the current status of the intensive white-leg shrimp farming in earthen system and tarpaulin pond system in Tra Vinh Province by interviewing 110 farmers in Trà Vinh from May to December of 2019. The results of the study showed that an average stocking density in earthen systemand tarpaulin pond system were at 195 and 87 inds/m2 and the number of crops for earthen and tarpaulin ponds are respectively from 1 - 2 crops and 2 - 3 crops per year. The harvested shrimp size and the productivity in tarpaulin ponds (35 inds /kg; 48 tons/ha/crop) were significantly higher than those in the in earthen ponds (58 inds /kg; 12 tons/ha/crop). The net income obtained from the tarpaulin ponds model (1.760 millionVND/ha/crop) was significantly higher than that in the earthen ponds (267 million VND/ha/crop). Food change ratio in tarpaulin ponds was higher than in earthen ponds. The advantages and disadvantages of white - leg shrimp farmers in two models are also mentioned in this report.

Background In 2016-2017, 68 women in Southern Vietnam had RT-PCR confirmed Zika virus (ZIKV) infection during pregnancy. We report here the outcomes of the pregnancies and the virological analyses related to this outbreak. Methods We collected clinical and epidemiological information from the women who were enrolled in the study. Medical records related to the pregnancy in 2016–2017 were retrieved for those who were not able to be enrolled in the study. Children born to women with ZIKV infection during pregnancy were also enrolled. Serum samples were evaluated for presence of ZIKV antibodies. Phylogenetic analyses were performed on Zika virus genomes sequenced from the 2016–2017 serum samples. Findings Of the 68 pregnancies, 58 were livebirths and 10 were medically terminated. Four of the medical records from cases of fetal demise were able to be retrieved, of which one was consistent with congenital ZIKV infection. Of the 58 women with a livebirth, 21 participated in the follow-up investigation. All but two women had serologic evidence of ZIKV infection. Of the 21 children included in the study (mean age: 30.3 months), 3 had microcephaly at birth. No other clinical abnormalities were reported and no differences in neurodevelopment were observed compared to a control group. Phylogenetic analysis revealed a clade within the ZIKV Asian lineage and branch at the root of samples from the 2013–2014 French Polynesian outbreak. The prM S139N mutation was not observed. Interpretation We have been able to demonstrate a clade within the ZIKV Asian lineage implicated in adverse pregnancy outcomes in Southern Vietnam. Funding INCEPTION project (PIA/ANR-16-CONV-0005) and a grant received from BNP Paribas Simplidon.

BackgroundThe risk factors for scrub typhus in Vietnam remain unknown. Scrub typhus caused byOrientia tsutsugamushioften presents as an undifferentiated febrile illness and remains under appreciated due to the limited availability of diagnostic tests. This tropical rickettsial illness is increasingly recognized as an important cause of non-malaria acute undifferentiated fever in Asia. This study aimed to investigate behavioural and ecological related risk factors of scrub typhus to prevent this potentially life-threatening disease in Vietnam.MethodsWe conducted a clinical hospital-based active surveillance study, and a retrospective residence-enrolment date-age-matched case–control study in Khanh Hoa province, Vietnam, from August 2018 to March 2020. Clinical examinations, polymerase chain reaction and enzyme-linked immunosorbent assay IgM tests were applied to define cases and controls. All enrolled participants filled out a questionnaire including demographic socio-economic status, personal behaviors/protective equipment, habitat connections, land use, and possible exposure to the vector. Multivariable conditional logistic regression was used to define the scrub typhus associated risk factors.ResultsWe identified 44 confirmed cases and matched them with 152 controls. Among cases and controls, the largest age group was the 41–50 years old and males accounted for 61.4% and 42.8%, respectively. There were similarities in demographic characteristics between the two groups, with the exception of occupation. Several factors were significantly associated with acquisition of scrub typhus, including sitting/laying directly on household floor [adjustedOR(aOR) = 4.9, 95%CI:1.6–15.1,P = 0.006], household with poor sanitation/conditions (aOR = 7.9, 95%CI:1.9–32.9,P = 0.005), workplace environment with risk (aOR = 3.0, 95%CI:1.2–7.6,P = 0.020), always observing mice around home (aOR = 3.7, 95%CI:1.4–9.9,P = 0.008), and use of personal protective equipment in the field (aOR = 0.4, 95%CI:0.1–1.1,P = 0.076).ConclusionsEcological and household hygiene-related factors were more associated with scrub typhus infection, than individual-level exposure activities in the hyper-endemic area. These findings support local education and allow people to protect themselves from scrub typhus, especially in areas with limitations in diagnostic capacity.Graphical abstract

This study was conducted through the interview of 48 households applying alternative system of the giant freshwater prawn and shrimp farming in Tra Vinh province. The study aimed to evaluate the effects of different factors on the efficiency of the prawn farming in order to contribute to sustainable development ofthe faming system in the brackish water area of the Mekong Delta. The results showed that the pond was in average area of 0.8 ha; water salinity varied in range of 1-10 ppt during prawn farming. Prawn stocking density was 9.0 inds./m2, and all of the prawn were fed with pellet feed or combined with by-products andtrash fish. After 5, 6 months of culture, average prawn yield of 886 kg/ha/crop and net income of 68 millions VND/ha/crop were achieved. Prawn farming covered only 28.5% of total production cost of the whole system including prawn and tiger shrimp but contributed up to 44.1% of total net income of the prawn -tiger shrimp system. A total of 89.6% of prawn farming households succeeded in getting net income, compared to 81.3% for tiger shrimp farming households. Inaddition, the study also found that factors such as water salinity, pond preparation, seed nursing and feeding methods strongly affect to the efficiency of prawn farming. The result indicated the great potential and feasibility for farming giant freshwater alternatively with tiger shrimp in brackish water areas of the Mekong delta.

BK DNAemia in renal transplant recipients is a significant cause of allograft dysfunction and can lead to graft loss due to BK polyomavirus-associated nephropathy or to graft rejection due to immunosuppression reduction. Currently, the first-line treatment for BK DNAemia is immunosuppression reduction. Second-line treatment for BK DNAemia has not been well-established. In this report, we present a case of a highly sensitized second-time pediatric renal transplant recipient with severe and persistent BK DNAemia and rising DSA, who was treated with IVIG and subsequently found to have clearance of BK viremia with concomitant reduction in DSA.

Listeriolysin O (LLO) is an important extracellular toxin of Listeria monocytogenes which degrades the phospholipid membranes of the host cells’ phagosomes at low pH during the intracellular survival. In contrast to the natural form, the mutant LLO carrying two replacements of amino acid E247M and D320K possesses stable activity at pH 7.4. In this study, we have constructed vectors that carry the mhlyA gene encoding double-mutated LLOE247M/D320K express in B. subtilis 1012. The target gene was fused to the sequence of LysRN-6xHis-TEV site to enhance the recombinant protein expression in B. subtilis and to ease the acquisition of protein by Ni2+-based affinity chromatography. As results, we have obtained the purified protein LLOE247M/D320K with high purity. The activity measurement with 3 HU hemolytic toxins in the pH range from 5.0 to 8.5 suggested that the activity of LLOE247M/D320K was much better than that of natural LLO at neutral pH and slightly alkaline. These results not only provided important scientific foundations for mutant LLO bases expression in B. subtilis but also supplied purified materials for researche and medical applications based on this protein.

Background Besides Escherichia coli, Bacillus subtilis is an important bacterial species for the production of recombinant proteins. Recombinant genes are inserted into shuttle expression vectors which replicate in both E. coli and in B. subtilis. The ligation products are first transformed into E. coli cells, analyzed for correct insertions, and the correct recombinant plasmids are then transformed into B. subtilis. A major problem using E. coli cells can be the strong basal level of expression of the recombinant protein which may interfere with the stability of the cells. To minimize this problem, we developed strong expression vectors being repressed in E. coli and inducer-free in B. subtilis. Results In general, induction of IPTG-inducible expression vectors is determined by the regulatory lacI gene encoding the LacI repressor in combination with the lacO operator on the promoter. To investigate the inducer-free properties of the vectors, we constructed inducer-free expression plasmids by removing the lacI gene and characterized their properties. First, we examined the ability to repress a reporter gene in E. coli, which is a prominent property facilitating the construction of the expression vectors carrying a target gene. The β-galactosidase (bgaB gene) basal levels expressed from Pgrac01-bgaB could be repressed at least twice in the E. coli cloning strain. Second, the inducer-free production of BgaB from four different plasmids with the Pgrac01 promoter in B. subtilis was investigated. As expected, BgaB expression levels of inducer-free constructs are at least 37 times higher than that of the inducible constructs in the absence of IPTG, and comparable to those in the presence of the inducer. Third, using efficient IPTG-inducible expression vectors containing the strong promoter Pgrac100, we could convert them into inducer-free expression plasmids. The BgaB production levels from the inducer-free plasmid in the absence of the inducer were at least 4.5 times higher than that of the inducible vector using the same promoter. Finally, we used gfp as a reporter gene in combination with the two promoters Pgrac01 and Pgrac100 to test the new vector types. The GFP expression levels could be repressed at least 1.5 times for the Pgrac01-gfp+ inducer-free construct in E. coli. The inducer-free constructs Pgrac01-gfp+ and Pgrac100-gfp+ allowed GFP expression at high levels from 23 × 104 to 32 × 104 RFU units and 9–13% of total intracellular proteins. We could reconfirm the two major advantages of the new inducer-free expression plasmids: (1) Strong repression of the target gene expression in the E. coli cloning strain, and (2) production of the target protein at high levels in B. subtilis in the absence of the inducer. Conclusions We propose a general strategy to generate inducer-free expression vector by using IPTG-inducible vectors, and more specifically we developed inducer-free expression plasmids using IPTG-inducible promoters in the absence of the LacI repressor. These plasmids could be an excellent choice for high-level production of recombinant proteins in B. subtilis without the addition of inducer and at the same time maintaining a low basal level of the recombinant proteins in E. coli. The repression of the recombinant gene expression would facilitate cloning of genes that potentially inhibit the growth of E. coli cloning strains. The inducer-free expression plasmids will be extended versions of the current available IPTG-inducible expression vectors for B. subtilis, in which all these vectors use the same cognate promoters. These inducer-free and previously developed IPTG-inducible expression plasmids will be a useful cassette to study gene expression at a small scale up to a larger scale up for the production of recombinant proteins.

Background: Carabelli’s trait is an inner knob near the second molar and the first permanent molar and has been used as an important ethnic index for decades. It can be used to show great ethnic differences in dentistry. Objectives: The aim of this longitudinal study was to determine: (1) the frequencies of Carabelli trait and (2) the relationship of Carabelli’s trait between the deciduous and permanent teeth. Method: The sample consisted of 64 pairs of dental casts (32 boys, 32 girls, aged 3–5 and 12–14) on Vietnamese people. Results: The frequencies of pits and grooves were high (deciduous teeth: 51.56%, permanent teeth: 39.06%). By contrast, the frequencies of pronounced tubercular forms were low (25% in both dentitions). The correlation coefficient between the deciduous and permanent teeth was 0.65 (p

Objectives: This longitudinal study examined the relationship between the crown diameters of the deciduous and permanent teeth to establish prediction equations for the permanent tooth crown diameters. Method: The mesiodistal and buccolingual diameters of 64 pairs of dental casts (32 boys, 32 girls, aged 3–5 and 12–14) were measured. Results: Correlation coefficients between the deciduous and permanent teeth varied from low to high (0.45 to 0.73 for mesiodistal diameters; 0.52 to 0.71 for buccolingual). The correlation coefficients for the groups of teeth varied from medium (0.59) to high (0.85) (p

Sonneratia alba J.E. Smith, Sonneratiaceae widely grows in mangrove forests. There were some studies on plants of mangrove forests, and these results showed they contained many interesting bioactive compounds. Nevertheless, Sonneratia alba has not much been studied, especially, has not yet been chemically and biologically studied in Viet Nam. From the petroleum ether extract of the leaves of Sonnertia alba, oleanolic acid (1), betulin (2), betulinic acid (3), alphitolic acid (4), methyl gallate (5) and 5-hydroxymethylfurfural (6) were isolated. Their structures were identified by comparing their NMR data as well as the physical properties with those in literatures. Among them, (1) had high yield (about 0.15% of dried leave) with numerous pharmacological activities including inhibitory activity against HIV-1 protease with IC50 of 6.3 mM, anti-inflammatory, anti-cancer. So, Sonneratia alba should be exploited to afford to a valuable source in food and pharmaceutical products. Further studies on this plant are in progress.

In eutherians, the sex-reversing ATRX gene on the X has no homologue on the Y chromosome. However, testis-specific and ubiquitously expressed X-borne genes have been identified in Australian marsupials. We studied nucleotide sequence and chromosomal location of ATRX homologues in two American marsupials, the opossums Didelphis virginiana and Monodelphis domestica. A PCR fragment of M. domestica ATRX was used to probe Southern blots and to screen male genomic libraries. Southern analysis demonstrated ATRX homologues on both X and Y in D. virginiana, and two clones were isolated which hybridized to a single position on the Y chromosome in male-derived cells but to multiple sites of the X in female cells. In M. domestica, there was a single clone that mapped to the X but not to the Y, suggesting that it represents the M. domestica ATRX. However a male-specific band was detected in Southern blots probed with the D. virginiana ATRY and with a mouse ATRX clone, which implies that the Y copy in M. domestica has diverged further from other ATRX homologues. Thus there appears to be a Y-borne copy of ATRY in American, as well as Australian marsupials, although it has diverged in sequence, as have other Y genes that are testis-specific in both eutherian and marsupial lineages.

Oocyte maturation and ovulation require a coordinated interaction between gonadotrophs, steroid hormones, and growth factors. The extent to which estrogen is required in this process, however, remains unclear. To better understand the role of estrogen in maintaining developmental competence of mammalian oocytes, we studied the Aromatase knockout (ArKO) mouse, which has been genetically engineered to be incapable of synthesizing endogenous estrogen. Previous studies have established that ArKO female mice are anovulatory with ovaries that progressively degenerate, developing hemorrhagic cystic follicles. In young ArKO females, however, apparently healthy follicles and oocytes have been observed. We investigated if these oocytes could be induced to ovulate, then mature, fertilize, and develop in vitro. Following a standard superovulation protocol, ArKO oocytes did not ovulate. When recovered manually from the ovary, however, ArKO oocytes successfully progressed through in vitro maturation, fertilization, and development to the blastocyst stage at the same rate as wild-type and heterozygote littermates. Therefore, it appears that estrogen is not required for the production and growth of oocytes capable of maturation and complete preimplantation development but is required for continued follicle growth and feedback regulation of ovulation.

The specific binding of transcription factors to cognate sequence elements is thought to be critical for the generation of specific gene expression programs. Members of the nuclear factor κB (NF-κB) and interferon (IFN) regulatory factor (IRF) transcription factor families bind to the κB site and the IFN response element (IRE), respectively, of target genes, and they are activated in macrophages after exposure to pathogens. However, how these factors produce pathogen-specific inflammatory and immune responses remains poorly understood. Combining top-down and bottom-up systems biology approaches, we have identified the NF-κB p50 homodimer as a regulator of IRF responses. Unbiased genome-wide expression and biochemical and structural analyses revealed that the p50 homodimer repressed a subset of IFN-inducible genes through a previously uncharacterized subclass of guanine-rich IRE (G-IRE) sequences. Mathematical modeling predicted that the p50 homodimer might enforce the stimulus specificity of composite promoters. Indeed, the production of the antiviral regulator IFN-β was rendered stimulus-specific by the binding of the p50 homodimer to the G-IRE–containing IFN β enhancer to suppress cytotoxic IFN signaling. Specifically, a deficiency in p50 resulted in the inappropriate production of IFN-β in response to bacterial DNA sensed by Toll-like receptor 9. This role for the NF-κB p50 homodimer in enforcing the specificity of the cellular response to pathogens by binding to a subset of IRE sequences alters our understanding of how the NF-κB and IRF signaling systems cooperate to regulate antimicrobial immunity.

The Millennium Villages Project (MVP) is a community-based comprehensive multi-sectoral approach to achieving the Millennium Development Goals (MDGs) in Africa over a five-year period. MVP and Ericsson's Consumer Lab collaborated to investigate the baseline conditions for enhanced connectivity and integrating mobile telephony in MVP sites. It is hypothesized that this will accelerate the achievement of the MDGs through improved communication and availability of information. Using quantitative and qualitative methods, the research team aimed to assess the effects of network strengthening and strategic integration in the context of a rural village in a low-income African country. Four Millennium Village sites were examined for this study on connectivity: Bonsaaso, Ghana; Dertu, Kenya; Ikaram, Nigeria; and Mbola, Tanzania. The survey results from the sites showed common attributes for mobile phone owners but usage trends differed across study sites. Given the results, in three of the four sites, there is a significant market to be explored for voice services to be strengthened and made more easily available in terms of infrastructure and costs. Lessons drawn from these sites can provide us with useful insights into the potential for development and use of mobile phones in the rest of the continent, in addition to providing useful policy implications.

Many or most genes on the mammal Y chromosome evolved a testis-specific function after diverging from an X-borne copy with a general function in both sexes. In marsupial but not eutherian mammals, a testis-specific orthologue (ATRY) of the widely expressed X-borne ATRX gene lies on the Y chromosome. Since mutations in human ATRX cause sex reversal, it is possible that one function of ATRY in marsupials is testicular differentiation. We report here the isolation and sequencing of the tammar wallaby (Macropus eugenii) ATRY cDNA, and comparison of its sequence with that of tammar ATRX. The evolution of a testis-specific function for the ATRY protein distinct from the general role of ATRX in both sexes has been accompanied by sequence changes in many protein domains that would alter protein binding partners. A large open reading frame encodes a 1771 amino acid ATRY protein that has diverged extensively from ATRX. The conservation and loss of particular motifs identify those required for testicular function (ATRY) and function in other tissues (ATRX).

The ATRX protein, associated with X-linked alpha-thalassaemia, mental retardation and developmental abnormalities including genital dysgenesis, has been proposed to function as a global transcriptional regulator within a multi-protein complex. However, an understanding of the composition and mechanics of this machinery has remained elusive. We applied inter-specific comparative analysis to identify conserved elements which may be involved in regulating the conformation of chromatin. As part of this study, we cloned and sequenced the entire translatable coding region (7.4 kb) of the ATRX gene from a model marsupial (tammar wallaby, Macropus eugenii). We identify an ATRX ancestral core, conserved between plants, fish and mammals, comprising the cysteine-rich and SWI2/SNF2 helicase-like regions and protein interaction domains. Our data are consistent with the model of the cysteine-rich region as a DNA-binding zinc finger adjacent to a protein-binding (plant homeodomain-like) domain. Alignment of vertebrate ATRX sequences highlights other conserved elements, including a negatively charged mammalian sequence which we propose to be involved in binding of positively charged histone tails.