Human proteomic profiles in latent and active tuberculosis

Distinguishing patients with active tuberculosis (TB) from those with latent TB is an important clinical problem. The SELDI-TOF MS (Surface Enhanced Laser Desorption Ionisation – Time of Flight Mass Spectrometry) platform allows for high throughput detection of multiple proteins in biological fluids. Proteomic patterns reflecting host-pathogen interaction can be used as a tool to aid our understanding of the Natural History of Tuberculosis. Methods: Plasma samples were collected prospectively in a shanty town in Lima, Peru. Latent and active TB status was defined using the Tuberculin Skin Test (TST), Quantiferon (QFN) assay and TB culture. Crude plasma and fractionated plasma samples were analysed on weak cationic CM10 chip surfaces using a Biomek 3000 Laboratory Automation Workstation. Spectra were generated using a ProteinChip System 4000 Mass spectrometer. Data was analysed using a Support Vector Machine. Results: Samples were collected from 154 patients with active TB, 112 patients with respiratory symptoms suggestive of TB and 151 healthy controls. Multiple peaks differed significantly between active TB patients and unhealthy controls. Trained optimal classifiers discriminate between: i) active TB and unhealthy controls with 84% accuracy (87% sensitivity, 79% specificity) in crude plasma and up to 89% accuracy (90% sensitivity, 88% specificity) in fractionated plasma ii) active TB and latent TB with 89% accuracy (90% sensitivity, 89% specificity) iii) latent TB and no TB in healthy controls with 77% accuracy (67% sensitivity, 84% specificity). Conclusions: SELDI-TOF MS proteomic profiles in combination with trained optimal classifiers accurately discriminate active TB from other respiratory disorders. The classifier for latent TB was not as accurate, but active TB could be discriminated from latent TB

Steady state and transient analysis of thermoelectric devices using finite element method

Thermoelectric devices offer noiseless and environment friendly operation, which makes them the most suitable devices of the future in their category. However, the performance of these devices is still way below its competitor thermal and electrical systems. The major factor that decides the performance of these devices is the thermoelectric material. Although the use of Silicon as a thermoelectric material greatly improved the performance of new thermoelectric devices over the metal based thermoelectric devices, it is still not close to the performance level of heat engines or refrigerators. With a limit on the material properties, these devices must be optimized based on all known effects that occur in the thermoelectric devices. The various effects that occur in a thermoelectric device are Seebeck effect, Peltier effect, Joule effect and Thomson effect. Most of the time, the design of thermoelectric generators and sensors is based on the steady state characteristics, which include only the governing thermoelectric effect (Seebeck effect) into the mathematical model. The Joule effect, Thomson effect and Peltier effect are historically assumed to have negligible influence on its performance characteristics. In this thesis, a complete steady state and transient model of thermoelectric generator is formed incorporating all the thermoelectric effects. The comprehensive model accounts for the internal heat generation inside the thermoelements due to the Joule effect and the Thomson effect. The Peltier effect is included as a plane heat source at the junctions that release heat in both directions. The model is formulated using finite element method, which is implemented into a computer program. The influence of different thermoelectric effects is studied under various working conditions. The use of finite element program, as a design tool for thermoelectric devices, is also demonstrated

An Optimized Two-Step Hybrid Block Method Formulated in Variable Step-Size Mode for Integrating y′′=f(x,y,y′)y''=f(x,y,y') Numerically.

[EN]An optimized two-step hybrid block method is presented for integrating general second order initial value problems numerically. The method considers two intra-step points which are selected adequately in order to optimize the local truncation errors of the main formulas for the solution and the first derivative at the final point of the block. The new proposed method is consistent, zero-stable and has seventh algebraic order of convergence. To illustrate the performance of the method, some numerical experiments are presented for solving this kind of problems, in comparison with methods of similar characteristics in the literature

Exponentially Fitted Variants of the Two-Step Adams-Bashforth Method for the Numerical Integration of Initial Problems

In this paper, we propose new variants of the two-step Adams-Bashforth and the one-step Adams-Moulton methods for the numerical integration of ordinary differential equations (ODEs). The methods are constructed geometrically from an exponentially fitted osculating parabola. The accuracy and stability of the proposed variants is discussed and their applicability to some initial value problems is also considered. Numerical experiments demonstrate that the exponentially fitted variants of the two-step Adams-Bashforth and the one-step Adams-Moulton methods outperform the existing classical two-step Adams-Bashforth and one-step Adams- Moulton methods respectively

Numerical solution of time dependent nonlinear partial differential equations using a novel block method coupled with compact finite difference schemes.

[EN]In this paper, we have developed a novel three step second derivative block method and coupled it with fourth order standard compact finite difference schemes for solving time dependent nonlinear partial differential equations (PDEs) of physical relevance. Two well-known problems viz. the FitzHugh–Nagumo equation and the Burgers’ equation have been considered as test problems to check the effectiveness of the proposed scheme. Firstly, we developed a novel block scheme and discussed its characteristics for solving initial-value systems, such as the one resulting from the discretization of the spatial derivatives that appear in the PDEs. Although many time integration techniques already exist to solve discretized PDEs, our goal is to develop a numerical scheme keeping in mind saving computational time while maintaining good accuracy. The proposed block scheme has been proved to be -stable and consistent. The method performs well for solving the stiff case of the FitzHugh–Nagumo equation, as well as for solving the Burgers equation at different values of viscosity and time. The numerical experiments reveal that the developed numerical scheme is computationally efficient

Evaluating capabilities of novel warm-season crops to fill forage deficit periods in the Southern Great Plains

Low nutritive value of perennial grasses during mid-late summer limits stocker cattle production in the Southern Great Plains (SGP). Our objectives were to explore annual crop species that might fit as a summer forage, and quantify their forage potentials under the highly variable agro-climatic conditions of the SGP. A field experiment compared the seasonal changes in aboveground dry matter (ADM), leaf-to-stem ratio, and chemical composition of tepary bean (Phaseolus acutifolius) and guar (Cyamopsis tetragonoloba) to soybean (Glycine max). Tepary bean outperformed soybean and guar by producing greater ADM (6.5 Mg ha-1) with a leaf-to-stem ratio of 3.1 at 65 days after planting (DAP), and its chemical composition also remained superior and consistent throughout the growing season. Secondly, ten mothbean (Vigna aconitifolia) lines were evaluated for their forage, grain or green manure potentials. Mothbean lines generated a ADM range of 7.3-18.1 Mg ha-1 with 10.8-14.6% crude protein (CP), 32.0-41.7% neutral detergent fiber (NDF), 20.7-29.6% acid detergent fiber (ADF), and 73-84% in vitro true digestibility (IVTD) at 100 DAP. Third, eleven finger millet (Eleusine coracana) accessions were assessed for their adaptability and forage characterization under the SGP conditions. Finger millet accessions resulted in ADM ranging from 5.0-12.3 Mg ha-1, which contained 10.5-15.6% CP, 59.8-73.4% NDF, 26.8-38.2% ADF, and 59.7-73.0% IVTD at 165 DAP. Finally, a greenhouse study was conducted to compare vegetative growth and physiological responses of mothbean, tepary and guar under four different water regimes. Tepary bean showed the lowest stomatal conductance (gs) and photosynthetic rate (A), but it maintained the highest instantaneous water use efficiency (WUEi) among species under water-stressed treatments. At final harvest (77 DAP), the ADM generated by tepary bean was 38-60% and 41-56% higher than guar and mothbean, respectively, across four water deficits. Tepary bean was identified as the most drought-tolerant and reliable option for SGP among the tested species, considering its higher biomass production, WUEi, leaf-to-stem ratio, and consistent nutritive value when grown as a summer forage. Future research should focus on defining management practices for growing these novel crops in extensive production settings for grazing or hay

An efficient optimized adaptive step-size hybrid block method for integrating w′′=f(t,w,w′) directly.

[EN]This article addresses the development and analysis of an efficient optimized hybrid block method for integrating general second order initial value problems (IVPs) of ordinary differential equations (ODEs). The construction of the method is based on a combination of two methodologies, namely hybrid and block that result in an efficient implicit numerical integrator. Further, an improved strategy is obtained considering its adaptive step-size formulation. Some numerical experiments have been carried out on solving some well-known problems existing in the literature with fixed and adaptive step-size implementation of the new scheme. Numerical data reveals that the new scheme is a good alternative to existing solvers with comparable properties

Antioxidant and Antimicrobial Properties of the Essential Oil and Extracts of Zanthoxylum alatum

The essential oil obtained from the fresh leaves of Zanthoxylum alatum was analysed by gas chromatography/mass spectrometry (GC/MS). Fourteen components were identified, and linalool (30.58%), 2-decanone (20.85%), β-fenchol (9.43%), 2-tridecanone (8.86%), β-phellandrene (5.99%), Sabinene (4.82%), and α-pinene (4.11%) were the main components. The EO and methanolic extract of Z. alatum exhibited potent antifungal activity against Alternaria alternata, Alternaria brassicae, and Curvularia lunata. The EO also showed significant antibacterial activity against Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, and Escherichia coli. Further, antimicrobial constituents of the EO were isolated by bioautography and preparative thin layer chromatography (PTLC) and identified as β-fenchol and linalool using GC/MS analysis. In addition to this, the free radical scavenging activity and antioxidant potential of EO and methanolic extract/fractions of Z. alatum were also investigated using in vitro assays including scavenging ability against DPPH•, reducing power and chelating ability on Fe2+ ions. Our results demonstrate that Z. alatum could be used as a resource of antioxidant and antimicrobial compounds which may find applications in food and pesticide industries

A High-Order Efficient Optimised Global Hybrid Method for Singular Two-Point Boundary Value Problems.

[EN]An optimised global hybrid block method for second order singular boundary value problems with two boundary conditions is developed. A special attention is paid to the problems having solutions with singularities at the left end of the interval considered. The method is a combination of known optimised hybrid formulas and a new set of formulas. The ad hoc procedure is used just to pass the singularity and the main formulas are applied to obtain approximations at other discrete points. Numerical experiments show that the method is a good alternative for the problems studied

Solving second order two-point boundary value problems accurately by a third derivative hybrid block integrator.

[EN]This article deals with the development of an optimized third-derivative hybrid block method for integrating general second order two-point boundary value problems (BVPs) subject to different types of boundary conditions (BCs) such as Dirichlet, Neumann or Robin. A purely interpolation and collocation approach has been used in order to develop the method. A constructive approach has been applied in the development of the method to consider two off-step optimal points among an infinite number of possible choices in a two-step block corresponding to a generic interval.The obtained method simultaneously produces an approximate solution over the entire integration interval. Some numerical experiments have been presented that show the good performance of the presented scheme