Mathematical modelling approach of the study of Ebola virus disease transmission dynamics in a developing country

Background: Ebola Virus causes disease both in human and non-human primatesespecially in developing countries. In 2014 during its outbreak, it led to majority of deaths especially in some impoverished area of West Africa and its effect is still witnessed up till date. Materials and Methods:We studied the spread of Ebola virus and obtained a system of equations comprising of eighteen equations which completely described the transmission of Ebola Virus ina population where control measures were incorporated and a major source of contacting the disease which is the traditional washing of dead bodies was also incorporated. We investigated the local stability of the disease-free equilibrium using the Jacobian Matrix approach and the disease-endemic stability using the center manifold theorem. We also investigated the global stability of the equilibrium points using the LaSalle's Invariant principle.Results: The result showed that the disease-free and endemic equilibrium where both local and globally stable and that the system exhibits a forward bifurcation.Conclusions: Numerical simulations were carried out and our graphs show that vaccine and condom use is best for susceptible population, quarantine is best for exposed population, isolation is best for infectious population and proper burial of the diseased dead is the best to avoid further disease spread in the population and have quicker and better recovery.

A comparative study of free laccase and laccase immobilized in copper alginate

Enzyme immobilization has gained considerable attention due to the incredible properties exhibited by the enzymes in immobilized condition. Therefore, in the present study, a comparative analysis of free and immobilized laccase is reported using various substrates. The ideal substrate for immobilization was found to be copper alginate with an immobilization yield of 91.078%. The optimum pH was 4 and 5, respectively, for free and immobilized enzymes while the optimum temperature was found to be 50 and 60?C, respectively. The kinetic parameters Vmax and Km were found from the Line weaver-Burk plot and were 48.076 U/mL and 0.480 mM for free enzyme while 55.55 U/mL and 1.277 mM for the immobilized enzyme, respectively. The catalytic efficiency Kcat was found as 100.01s?1 for free enzyme and 43.5s?1 for its immobilized counterpart. Out of the various metal ions used, Co2+ was found to enhance the activity of an immobilized enzymes. The storage stability of the enzyme was studied and was found that only 32.44% of initial activity was retained by free enzyme whereas, 70.21% of activity was retained by immobilized enzyme upon storage for four weeks at 4?C. The thermal stability studies shows that the immobilized enzyme retained 32.60% of its initial activity and the free enzyme retained 1.14% of initial activity on exposure to 60?C for 3 h. Finally, the reusability of immobilized laccase beads was evaluated by decolorization of methyl orange for five repeated cycles and a percentage decolorization of 32.04% could be retained at the fifth cycle. This study therefore, suggests copper alginate-immobilized beads to be an effective option for various applications

Elucidation of genotype–environment interactions and genetic stability parameters for yield, quality and agromorphological traits in ashwagandha (Withania somnifera (L.) Dunal)

The present study was undertaken to delineate genotype–environment interactions and stability status of 16 genotypes of ashwagandha (Withania somnifera (L.) Dunal) in context to the 12 characters, namely plant height, number of primary branches, number of secondary branches, days to flowering, days to maturity, number of berries, number of seeds/berry, root length, root diameter, root branches, dry root yield and total alkaloid content (%). Experiment was carried out in a randomized complete block design with three replications over three different locations (S. K. Nagar, Jagudan and Bhiloda) in north Gujarat for three years (2016–17, 2017–18 and 2018–19). Pooled analysis of variance revealed that the mean squares due to genotypes and genotype 9 environment interaction along with linear and nonlinear components were highly significant (P\0.01) for most of the traits under study. Stability parameters for component traits through Eberhart and Russell model showed that genotypes that can be used directly in breeding programme are SKA-4 for early flowering, SKA21 for early maturity and SKA-1, SKA-4, SKA-6 and SKA-17 for shorter plant height. Further, SKA-21 could be used for improving number of primary branches per plant, SKA-11 and SKA-17 for number of secondary branches per plant, SKA-19 for number of berries per plant, SKA-6, SKA-21, SKA-27 and AWS-1 for root branches and SKA-17 for root length as these genotypes were found to be most stable across the environments for mentioned traits. The result revealed that some reliable predictions about genotype 9 environment interaction and its unpredictable components were involved significantly in determining the stability of genotypes. Hence, the present investigation can be exploited for the identification of more productive genotypes in specific environments, leading to significant increase in root productivity of ashwagandha

Cloning and expression stability analysis of Actin, Tubulin and GAPDH genes in Dipsacus asper / 中草药

Objective: To clone and screen the stable internal reference genes from Dipsacus asper for qRT-PCR analysis correction, so as to provide a preliminary basis for future research on expression analysis and regulation mechanism of D. asper functional genes. Methods: The internal reference genes of Actin, Tubulin and GAPDH gene families were screened and cloned from D. asper transcriptome database. The D. asper plants from different origins, different tissues and different developmental stages were used to obtain expression information of each gene by qRT-PCR. The expression stability of each gene was analyzed by geNorm, NormFinder, BestKeeper, Delta CT and RefFinder, and the best genes were synthetically evaluated and screened. Results: Ten core fragments for candidate internal reference genes were cloned, belonging to three gene families: Actin, Tubulin and GAPDH, with high homology among them. The results of stability analysis showed that the expression of DaACT103 was stable and relatively high in different regions and tissues, while the expression of DaTUB5 was stable and relatively low in different developmental stages. Conclusion:s DaACT103 and DaTUB5 are suitable as the internal reference genes for D. asper. DaACT103 is used as the internal reference gene with high abundances and DaACT105 is used as the internal reference gene with low abundances.

Stability of the hypocotyl length of soybean cultivars using neural networks and traditional methods / Estabilidade do comprimento do hipocótilo de plantas de cultivares de soja por meio de redes neurais e metodologias tradicionais

ABSTRACT: The length of the hypocotyl has been highlighted as a potential descriptor of the soybean crop. However, there is no information available in the published literature about its behavior over several planting times. The present study aimed to identify soybean cultivars with stability and predictability of hypocotyl length behavior through neural networks and traditional adaptability and stability methodologies. We analyzed 16 soybean cultivars in 6 planting seasons under greenhouse conditions. In each season, a randomized block design with 4 replications was adopted. The experimental unit was composed of 3 plants. The plot mean was used in the analysis. Hypocotyl length data were analyzed by analysis of variance and Tukey's test. Then analyses were carried out using the Traditional Method, Plaisted and Peterson, Wricke, Eberhart and Russell, and Artificial Neural Networks. A significant effect (p<0.01 by the F test) was identified for Cultivars versus Planting Season and Planting Seasons and Cultivars. Cultivars BRS810C, BRSMG760SRR, TMG1175RR, and BMX Tornado RR showed lower averages, high stability, and general adaptability regarding soybean hypocotyl length whereas the cultivar BG4272 presented higher mean, high stability, and general adaptability. Identification of soybean cultivars of predictable and stable behavior as to hypocotyl length contributes to Soybean Improvement as it further our knowledge on the potential descriptor and the possibility of increasing the number of descriptors.

RESUMO: O comprimento do hipocótilo tem-se destacado como potencial descritor da cultura da soja, no entanto, não se tem informação sobre o seu comportamento ao longo de várias épocas de plantio. Diante disto, objetivou-se identificar cultivares de soja com estabilidade e previsibilidade de comportamento quanto ao comprimento do hipocótilo por meio de redes neurais e metodologias tradicionais de adaptabilidade e estabilidade. Analisou-se 16 cultivares de soja em seis épocas de plantio, em condições de casa de vegetação. Em cada época, adotou-se o delineamento em blocos casualizados com quatro repetições, sendo a unidade experimental composta por três plantas e usou-se a média da parcela na análise. Os dados de comprimento de hipocótilo foram analisados por meio da análise de variância e teste de Tukey e, posteriormente, procedeu-se análises por meio do Método Tradicional, Plaisted e Peterson, Wricke, Eberhart e Russell e Redes Neurais Artificiais. Identificou-se efeito significativo (p<0,01 pelo teste F) para Cultivares x Épocas, Épocas e Cultivares. As cultivares BRS810C, BRSMG760SRR, TMG1175RR e BMX Tornado RR apresentaram menores médias, alta estabilidade e adaptabilidade geral quanto ao comprimento do hipocótilo de soja; enquanto que, a cultivar BG4272 apresentou maior média, alta estabilidade e adaptabilidade geral. A identificação de cultivares de soja de comportamento previsível e estável, quanto ao comprimento do hipocótilo, contribui para o Melhoramento da Soja no tocante ao melhor conhecimento do potencial descritor e à possibilidade de incremento do número de descritores.

Regional stability analysis of Pseudostellariae Radix new variety "Shitai No.1" / 中国中药杂志

To provide guidance for certification, popularization and application of Pseudostellariae Radix new variety, the regional adaptation and stabilities of "Shitai No.1" were evaluated. The "Qian taizishen No.1" and "SB-C" varieties (strains) were used as the control varieties. The agronomic, medicinal material traits and medicine quality were used as evaluation index to compare the phenotypic difference of the three varieties (strains) in four planting areas. Compared to the control varieties, 10 agronomic traits of "Shitai No.1" had the smallest coefficient of variation among the 18 agronomic traits, and other 8 agronomic traits placed the middle level. Among 8 medicinal material traits and medicine quality indicators, the coefficient of variation of different regions of the extract content, pseudostellarin B content, the number of 50 g root tuber, the plant medicinal materials weight and weight of single root of "Shitai No.1" were the smallest compare to other varieties (strains). It could be divided into three groups based on the phenotypic difference of the three varieties (strains) in four planting areas. The "Shitai No.1" was classified as one group, while the "Qian taizishen No.1" and "SB-C" had cross clustering. The regional stability of several index about agronomic traits, medicinal material traits and medicine quality of "Shitai No.1" were better than that of the control varieties (strains). "Shitai No.1" was suitable for planting, popularization and application in the appropriate ecological areas of Guizhou province.

Influencia de las regiones de estabilidad del biorreactor en la producción eficiente de alcohol carburante / Influence of bioreactor stability regions in the efficient production of fuel ethanol

Colombia ha desarrollado un proyecto ambicioso en la producción de alcohol carburante, y actualmente es uno de los países líderes de América Latina en la producción de biocombustibles. No obstante, algunas de sus plantas industriales productoras de etanol presentan problemas durante el arranque y la operación de los fermentadores, que afectan adversamente la productividad del proceso global. Estudios teóricos y experimentales demuestran que el comportamiento dinámico del proceso depende de los fenómenos de estabilidad que exhibe el sistema. En este trabajo se muestra la influencia de las regiones de estabilidad sobre la eficiencia del proceso tomando como criterios de evaluación índices de impacto económico y ambiental. Para esto, se realizó un análisis de estabilidad donde se tomó como parámetro de operación principal la velocidad de dilución. Se empleó un programa propio desarrollado sobre Matlab® para generar diagramas de bifurcación y de fase. El algoritmo de reducción de residuos (WAR) desarrollado por la Agencia de Protección Ambiental de los Estados Unidos, y el software SuperPro Designer®, fueron utilizados respectivamente para hacer la evaluación ambiental y económica del proceso. Como resultado, se evidenció que los procesos continuos de fermentación se pueden llevar a cabo en diferentes regiones de estabilidad, y que las variables de respuesta, tales como el rendimiento, dependen de la región de operación seleccionada. Finalmente, se llegó a la conclusión de que la evaluación de la estabilidad de los procesos de fermentación debe incluirse en las etapas de diseño de bioprocesos para garantizar su buen desempeño.

Colombia has developed an ambitious project to produce fuel ethanol. Nowadays, Colombia is one of the leading countries in Latin America for the biofuels production. However, some of its industrial plants producing ethanol present problems during the startup and the operation of fermenters, which adversely affects the productivity of the global process. Theoretical and experimental studies show that the process’ dynamic behavior depends on the stability phenomenon exhibited by the system. This work shows the influence of the stability regions on the process’ efficiency. For this, economic and environmental index were used. A stability analysis was carried out. The dilution rate was selected as the main operating parameter. An own program developed on Matlab® was used to generate bifurcation diagrams and phase diagrams. The Waste Reduction Algorithm (WAR) developed by the Environmental Protection Agency of the United States, and the SuperPro Designer® software were used for estimating the environmental and economic assessment of the process. As a result, it was shown that continuous fermentation processes can be carried out in different stability regions. Likewise, it was shown that the response variables, such as the yield, depend on the selected operating region. Finally, it was concluded that the evaluation of fermentation processes’ stability must be included in the stages for designing of bioprocess in order to ensure a good performance.

Nonparametric stability methods for interpreting genotype by environment interaction of bread wheat genotypes (Triticum aestivum L. )

Evaluation of performance stability and high yield is essential for yield trials conducted in different environments. We determined the stability of 10 bread wheat (Triticum aestivum L.) genotypes (5 cultivars and 5 advanced lines) using nonparametric stability measures and compared nonparametric stability statistics across 19 environments in the Central Anatolian Region of Turkey. Experiments were setup in a randomized complete block design with four replications. Nonparametric stability measures revealed that AL-2, Karahan-99 and Altay-2000 were the most stable and well adapted genotypes across the 19 environments. In addition, it was concluded that graphs of mean grain yield (t ha-1) vs. nonparametric measures (Si(1), Si(2), S(3), Si(6) and sigma-gy) values and kr vs. sigma-r values could enhance visual efficiency of genotype selection based on genotype by environment interaction. Furthermore, high TOP values, Si(3) and Si(6) were associated with high grain yield, but the other nonparametric stability measures were not positively correlated with grain yield and instead characterized a static concept of stability. Choice of genotype for increased grain yield in bread wheat would, therefore, be expected to change yield stability by increasing the values of the Si(3), Si(6) and TOP nonparametric stability statistics.

EFFICIENT STEADY-STATE ANALYSIS METHOD FOR CLOSED-LOOP PWM SWITCHING CONVERTERS / 药物分析学报

An analysis technique of steady state and stability for closed-loop PWM DC/DC switching converters is presented. Using this method, the closed-loop switching converter is transformed into an open-loop system. By means of the fact that in steady state, the two boundary values are equal in one switching period. The exponential matrix is evaluated by precise time-domain-integration method, and then the related curve between feedback duty cycle and the input one is obtained. Not only can the steady-state duty cycle be found from the curve, but also the stability and stable domain of the system. Compared with other methods, it features with simplicity and less calculation, and fit for numerical simulation and analysis for closed-loop switching converters. The simulation results of examples indicate the correctness of the presented method.