Technical, Economic and Environmental Evaluation on Mechanical Rice Straw Gathering Method

Rice straw is a rice by-product, which is currently mostly wasted in Vietnam, in particular in the Mekong delta. At present, the cost of straw gathering is increasing because of the increased use of combine harvesters. High labor cost and lack of labor makes manual collection unfeasible. Farmers therefore often just burn it, which causes pollution, increased greenhouse gas emissions and loss of opportunities to value add. An economic and environmental evaluation and technical field testing of a straw baler with 4 ha/day capacity was therefore conducted in Long An province. During the field testing data on the gathering capacity, fuel consumption, labor requirement and other cost items were collected. The test results showed that the baling cost is US$19.0 per ton of rice straw, the pay-back period of 2. 1 years and the internal rate of return of 38%. In addition to the baling cost, the transportation cost varies from US$24 for a distance of 100 km to US$32 for 150 km. The benefits of the machine are not only economical but also include the reduction of field burning.

A Simple Procedure for Extraction of Surface Protein of Salmonella Serotypes and Escherichia coli Strains Isolated from Poultry and Pigs

Salmonella and E.coli possess different surface protein structures that can induce protective immune responses.Identification of these proteins capacitates development of diverse applications in prevention and diagnosis that contribute to effectively control disease-causing enterobacteria pathogens such as Salmonella and E.coli.A simple procedure for obtaining protein complexes of Salmonella serotypes and E.coli is performed in this study.A sonication process with heat treatment of whole bacteria induced the release of protein complexes.Concentration of the protein extract was quantified using protein quantification Kits-Rapid,and protein complex profile was obtained by SDS-PAGE(Sodium dodecyl sulfate polyacrylamide gel electrophoresis)and silver staining.The concentrations of protein ranged from 29.45 to 45.35μg/mL in the Salmonella protein extracts,and from 25.35 to 36.72μg/mL in the E.coli protein extracts.Six major groups of proteins from E.coli(YfiO,NipB,OmpF,YfgL,Talc,YaeT)and four major groups of proteins from Salmonella(Flagellin,OmpA,Porin,SEF21)were preliminarily determined by a simple procedure of extraction based on the molecular weight.

Green Synthesis of Silver Nanoparticles Using Plectranthus Amboinicus Leaf Extract for Preparation of CMC/PVA Nanocomposite Film

In the present study,the biogenic silver nanoparticles have been synthesized using aqueous leaf extract of Plectranthus amboinicus(PA),which acted as both reducing and stabilizing agents.The PA synthesized silver nanoparticles were blended with carboxymethyl cellulose/polyvinyl alcohol(CMC/PVA)biocomposite.The prepared AgNPs as well as the biogenic AgNPs incorporated CMC/PVA films were investigated using UV-visible spectrophotometry,Fourier-transform infrared spectroscopy(FT-IR),dynamic light scattering(DLS),scanning electron microscope(SEM),and X–ray diffraction(XRD).The DLS results showed that biogenic AgNPs had the average particle size of 65.70 nm with polydispersity index of 0.44.The surface plasmon resonance of AgNPs,which was determined by UV-vis spectrophotometry,showed the value of 410.00 nm.These results therefore confirmed the reduction Ag+into Ag°and the formation of AgNPs in the medium.The SEM imaging showed that AgNPs was quasi-spherical and monodisperse.The XRD peaks at 33.07°,44.19°,64.58°and 77.47°confirmed the crystalline nature and presence of AgNPs.The CMC/PVA films that incorporated with AgNPs displayed best mechanical strength and morphological properties than the pure CMC/PVA film.The film of CMC/PVA-AgNPs exhibited significant antibacterial activities against Bacillus spizizenii,Staphylococcus aureus,Salmonella typhi and Escherichia Coli.

Dietary plant extracts modulate gene expression profiles in alveolar macrophages of pigs experimentally infected with porcine reproductive and respiratory syndrome virus

Background: Our previous study showed that 3 plant extracts enhanced the immune responses and growth efficiency of weaned pigs infected with porcine reproductive and respiratory syndrome virus(PRRSV), which is one of the most economically important disease in swine industry. However, each plant extract differently effected on growth efficiency and immune responses. Therefore, the objective of this study was conducted to characterize the effects and investigate the potential underlying mechanisms of 3 plant extracts on gene expression of alveolar macrophages in weaned pigs experimentally infected with PRRSV.Results: PRRSV infection altered(P < 0.05) the expression of 1,352 genes in pigs fed the control(CON;755 up, 597 down). Compared with the infected CON, feeding capsicum(CAP), garlic botanical(GAR), or turmeric oleoresin(TUR) altered the expression of 46 genes(24 up, 22 down), 134 genes(59 up, 75 down), or 98 genes(55 up, 43 down) in alveolar macrophages of PRRSV-infected pigs, respectively. PRRSV infection up-regulated(P < 0.05) the expression of genes related to cell apoptosis, immune system process, and response to stimulus, but downregulated(P < 0.05) the expression of genes involved in signaling transduction and innate immune response.Compared with the infected CON, feeding TUR or GAR reduced(P < 0.05) the expression of genes associated with antigen processing and presentation, feeding CAP up-regulated(P < 0.05) the expression of genes involved in antigen processing and presentation. Supplementation of CAP, GAR, or TUR also enhanced(P < 0.05) the expression of several genes related to amino acid metabolism, steroid hormone synthesis, or RNA degradation, respectively.Conclusions: The results suggest that 3 plant extracts differently regulated the expression of genes in alveolar macrophages of PRRSV-infected pigs, especially altering genes involved in immunity.

Parameters Effecting on Head Brown Rice Recovery and Energy Consumption of Rubber Roll and Stone Disk Dehusking

Application of improper methods on rice processing affects rice quality and head rice recovery. In Vietnam, paddy with different moisture contents （from 13% to 17%） is dehusked by both rubber roll and stone disk. Thus, objective of this research was to evaluate the technical and economic aspects of the two methods. Optimization was conducted with 20 experiments for input factors （moisture content） and output factors （head brown rice recovery, specific energy consumption）. Besides, other factors were also monitored, such as the gap between the two disks, speed of disk and roll, and pressure of rubber roll on paddy. Test results showed that the maximum value of head brown rice （77.4%） and the minimum value of specific energy consumption （0.66 kWh/ton） corresponding to moisture content of paddy of 13.7% for stone disk dehusker. At similar moisture content （13.7%）, head brown rice recovery and specific energy consumption were 77.2% and 1.04 kWh/ton for rubber roll dehusker, respectively. As the result, specific energy consumption of rubber roll dehusker was higher than that of stone disk dehusker, corresponding to the higher dehusking efficiency.

PRRS in Vietnam and Its Diagnosis

Genotyping 42 serum samples taken from the pigs in the oubreaks from 2009 to 2013 with RT-PCR and nested RT-PCR, showed more than 80% of samples were positive with Chinese PRRSV clade, and the others were European and North American classical PRRSV genotypes. Ten serum samples from unnapprent PRRS herds were examined for antibodies against PRRSV with ELISA and also for PRRSV with RT-PCR. It was clearly that the titer of antibodies against PRRSV by ELISA test could not be used for interpreting PRRSV infection. In despite of PRRS vaccination or non-vaccination, a risk of PRRSV infection and re-infection exist, utilizing RT-PCR in combination with serology will give the producer and veterinarian PRRSV more exact situation in the herds.

Forest Structure and a Sustainable Management Solution at the Permanent Plot in Bidoup-Nui Ba National Park

Vietnam is one of the countries with high biological diversity in the world but also greatly influenced by climate change.Therefore,it is necessary to have a solution for sustainable forest management through field surveys in permanent plots to study forest ecology,combining advanced GIS(Geographic Information System)technologies such as Google Earth,Global Mapper,etc.to monitor changes in forest structure and dynamics.The paper is based on the inheritance of the first measurement data in 2012 and directly measures in the second time after 5 years in 2017 at a 10-ha plot with ten 1-ha subplots.The results show that the number of trees is the highest at the diameter class of 10-20 cm(<20 cm),accounting for about 60%of the total number of trees of each 1-ha sub-plot and the study site and at the height of<20 m,respectively 8,402 out of 10,261 in 2012 and 8,189 out of 10,013 in 2017 were measured.In addition,the result of this paper indicates that Google Earth software is one of the most effective GIS tools in planning biodiversity conservation strategies and natural resource management.

Research on Cassava Drying, Application and Promotion of the Reversible Airflow Flatbed Dryers for Sliced Cassava

The study was conducted by researchers of the Research Center for Agricultural Energy and Machinery （CAEM） of the Ho Chi Minh City Nong Lam University （NLU） with the objectives of researching on drying ways for cassava and of evaluating the adaptability of the reversible-airflow dryers in drying of cassava. The results obtained were as follows： done with thin-layer drying experiments, deep-layer drying experiments in the lab, and conducted drying experiments at the cassava dryer in actual production scale with two capacity sizes of 8 tons/batch and 16 tons/batch, that operates based on principle of reversible-airflow drying （SRA dryers）. By the means of drying experiments, the performance of the SRA dryers such as optimal drying temperature, drying time, drying airflow reversal timing, moisture content uniformity of the sliced cassava mass after finishing drying process, drying cost, etc. was defined, the optimal drying temperature was 70 ~C, the total actual drying time for finishing one batch was 25-28 hours, applicable time for drying airflow reversal was after drying 16 hours since startup, the deviation in moisture content of the cassava mass after drying was just 2%-3%, the drying costs （per one kg of dried cassava） calculated were in turns VND407/kg at the SRA-8 dryer （8 tons/batch）, and VND351/kg at the SRA-16 dryer （16 tons/batch）. Obviously, comparing with the sale price of dry cassava at present, these levels of drying cost are accounting for 7%-10%, which are suitable and acceptable. Thus, investment of the dryers for sliced cassava would be effective and contribute to bring more income for Vietnamese cassava farmers and dryer end-users.

Determination of the Administration Routes,Doses and Appropriate Age to Vaccinate With Ornitin Triple Vaccine For Cross-breed Colored Broilers in Vietnam

The study was to determine the appropriate dose and administration route of Ornitin Triple vaccine in cross-breed coloured broilers in Vietnam by evaluating the antibody titer against Ornithobacterium rhinotracheale(ORT)and local reactions at injection sites on chickens after vaccination.The study was divided into 2 trials.Both trials were designed with 3 vaccine dose groups:0.0ml(control group),0.25ml and 0.5ml and 2 different administration routes:subcutaneous at neck(SC)and intramuscular at breast(IM)injection.The result showed that,no statistically significant difference was found between antibody titer of two administration routes as well as 2 vaccine doses until 13-week-old.Local reactions at the injection sites of IM route was less severe than SC at neck and in higher dose would produce a more severe swelling reaction.Daily weight gain was found to have a slight decrease in the vaccinated groups within 2 weeks after vaccination,however,no statistically significant difference was found in later stage(P>0.05).In conclusion,Ornitin Triple can be used to vaccinate by IM with the dose of 0.25ml for coloured broilers at early age(3-week-old),or 0.5ml for older birds and should be careful for some reactions at the injection sites.

Applications of Bootstrap in Analyzing General Extreme Value Distributions

The bootstrap method is one of the new ways of studying statistical math which this article uses but is a major tool for studying and evaluating the values of parameters in probability distribution.Our research is concerned overview of the theory of infinite distribution functions.The tool to deal with the problems raised in the paper is the mathematical methods of random analysis(theory of random process and multivariate statistics).In this article,we introduce the new function to find out the bias and standard error with jackknife method for Generalized Extreme Value distributions.

Comparative Study of Light Manipulation in Three-Level Systems Via Spontaneously Generated Coherence and Relative Phase of Laser Fields

We present a comparative study of the control of group velocity in three-level atomic systems including Λ-, Ladder-, and V-types via spontaneously generated coherence(SGC) and relative phase of laser fields.In the steady regime, expressions of group index are derived as an analytical function of controllable parameters related to SGC and relative phase.It is shown that the group velocity can be further slowed down or speeded up under SGC in which modifications of group velocity due to the SGC in Λ-and V-systems are stronger than that in Ladder-system.In particular, when interference strength of SGC p increases from 0.7 to 1.0, the light propagation is switched from superluminal to subluminal modes(for Λ-and Ladder-systems) or from subluminal to superluminal modes(for Vsystem).In the presence of relative phase, the group velocity changes between subluminal and superluminal modes with a period of 2π.In resonant region, the largest positive value of group index reaches at the relative phase φ=π while the largest negative value of group index reaches at φ= 0 and 2π for the Λ-and Ladder-systems, otherwise, for the V-system the largest positive group index occurs at φ= 0 and 2π, and the largest negative group index occurs at φ=π.