Series Solution of the Multispecies Lotka-Volterra Equations by Means of the Homotopy Analysis Method

The time evolution of the multispecies Lotka-Volterra system is investigated by the homotopy analysis method (HAM). The continuous solution for the nonlinear system is given, which provides a convenient and straightforward approach to calculate the dynamics of the system. The HAM continuous solution generated by polynomial base functions is of comparable accuracy to the purely numerical fourth-order Runge-Kutta method. The convergence theorem for the three-dimensional case is also given

Smart e-trader: A prototype information management system for UAE stock markets

This paper presents a new online smart trading approach for investors in UAE stock markets. Smart trader is a web-based information management system that provides investors with real time stock market information and personalized stock recommendations. A study was conducted to assess the needs for such system in UAE markets and found a strong demand for it among investors. A new system architecture is also proposed, called smart e- trader, to accommodate investors\u27 new needs and preferences. A prototype system of smart trader has been implemented to evaluate the usefulness and effectiveness of the new approach. The findings of this research suggests that deploying a smart online stock trading applications in UAE markets would help investors make an informative investment decisions as well as assist them manage their stock trading transactions

Vegetation Diversity in Natural and Restored Forested Wetland Sites in Southeast Arkansas

The loss of forested wetlands in the Lower Mississippi River Alluvial Valley in Arkansas has altered regional vegetation communities. Multiple restoration projects have been established in this region to restore wetlands and the services they provide. In order to return these functions to the environment, microtopographic features were constructed in 2001 at Bob White Memorial Wetlands Research and Teaching Station (Bob White). Vegetation diversity was examined at Cut-Off Creek Wildlife Management Area (Cutoff), a naturally forested wetland, and Bob White, an area formally converted to cropland that is now undergoing forest wetland restoration. Vegetation diversity is one way to determine if restoration efforts are effectively restoring ecosystem structure and functions to natural wetland conditions. Vegetation diversity and composition were examined across three topographical features: hummocks/ridges, swales, and flats. Vegetation diversity was examined in the spring, summer, and fall. Indices were used for determining composition similarities between Bob White and Cutoff. Bob White had a species richness of 33 and Cutoff’s species richness was 47. Beta diversity between the two sites was 76 species, this value is high and suggests there is low similarity between the two sites. Sorensen-Dice Similarity Index value was calculated as 0.05, where on a scale of zero to one a low value indicates low similarity in composition. The low similarity between the two sites suggests that vegetation composition at Bob White has not been fully restored to conditions comparable to a natural setting. An explanation for this is the presence of Baccharis halimifolia (Eastern baccharis). B. halimifolia inhibits other species from colonizing. Another factor for the difference between the vegetation at Bob White and Cutoff is that Cutoff is an older forest. Hydrophyte communities in a forested wetland take 50 years after restoration begins for them to resemble a natural forested wetland. The results from this study provide mixed evidence that restoration at Bob White is succeeding; there is a high percentage of wetlands species, while vegetation lacks similarity. This study improves our understanding of the influence that anthropogenic changes have on wetland functions as agricultural lands are restored to their previous land cover. Ecosystem functions should continue to be monitored to determine time frames as these functions are restored to Bob Whit

Effect of pulsed magnetic field pre-treatment of AISI 52100 steel on the coefficient of sliding friction and wear in pin-on-disk tests

Disc specimens manufactured from commercial bearing rollers (AISI 52100 steel, 62–63 HRC) in initial state and after pre-treatment by pulsed magnetic field (PMF) with a magnetic field strength of 1–7 MA/m were tested with sunflower oil using pin-on-disk apparatus. According to the obtained results the treatment causes a reduction in the coefficient of friction and wear. To explain the results, nano- and microhardness tests as well as optical and atomic force microscopy were used. Reasons of the effect of PMF on the friction and wear were discussed.Peer reviewe

Boundary layer flow of nanofluid over an exponentially stretching surface

The steady boundary layer flow of nanofluid over an exponential stretching surface is investigated analytically. The transport equations include the effects of Brownian motion parameter and thermophoresis parameter. The highly nonlinear coupled partial differential equations are simplified with the help of suitable similarity transformations. The reduced equations are then solved analytically with the help of homotopy analysis method (HAM). The convergence of HAM solutions are obtained by plotting h-curve. The expressions for velocity, temperature and nanoparticle volume fraction are computed for some values of the parameters namely, suction injection parameter α, Lewis number Le, the Brownian motion parameter Nb and thermophoresis parameter Nt

Transverse Spin at PHENIX: Results and Prospects

The Relativistic Heavy Ion Collider (RHIC), as the world's first and only polarized proton collider, offers a unique environment in which to study the spin structure of the proton. In order to study the proton's transverse spin structure, the PHENIX experiment at RHIC took data with transversely polarized beams in 2001-02 and 2005, and it has plans for further running with transverse polarization in 2006 and beyond. Results from early running as well as prospective measurements for the future will be discussed.Comment: 6 pages, 2 figures, presented at Transversity 2005, Como, Ital

Altered respiratory microbiota composition and functionality associated with asthma early in life

BACKGROUND: The microbiota of the respiratory tract has an important role in maintaining respiratory health. However, little is known on the respiratory microbiota in asthmatic patients among Middle Eastern populations. This study investigated the respiratory microbiota composition and functionality associated with asthma in Emirati subjects. METHODS: We performed 16S rRNA and ITS2-gene based microbial profiling of 40 expectorated sputum samples from adult and pediatric Emirati individuals averaging 52 and 7 years of age, respectively with or without asthma. RESULTS: We report bacterial difference belonging to Bacteroidetes, Firmicutes, Fusobacteria and Proteobacteria phyla between asthmatic and non-asthmatic controls. Similarly, fungal difference belonging to Ascomycota, Basidiomycota phyla and other unclassified fungi. Differential abundance testing among asthmatic individuals with relation to Asthma Control Test show a significant depletion of Penicillium aethiopicum and Alternaria spp., among poorly controlled asthmatics. Moreover, data suggest a significant expansion of Malassezia spp. and other unclassified fungi in the airways of those receiving steroids and leukotriene receptor antagonists’ combination therapy, in contrast to those receiving steroids alone. Functional profiling from 16S data showed marked differences between pediatric asthmatic and non-asthmatic controls, with pediatric asthmatic patients showing an increase in amino acid (p-value < 5.03 × 10− 7), carbohydrate (p-value < 4.76 × 10− 7), and fatty acid degradation (p-value < 6.65 × 10− 7) pathways, whereas non-asthmatic controls are associated with increase in amino acid (p-value < 8.34 × 10− 7), carbohydrate (p-value < 3.65 × 10− 7), and fatty acid (p-value < 2.18 × 10− 6) biosynthesis pathways in concordance with enterotype composition. CONCLUSIONS: These differences provide an insight into respiratory microbiota composition in Emirati population and its possible role in the development of asthma early in life. This study provides important information that may eventually lead to the development of screening biomarkers to predict early asthma development and novel therapeutic approaches

Extremal number of theta graphs of order 7

For a set of graphsF, letH(n;F) denote the class of non-bipartiteHamiltonian graphs onnvertices that does not contain any graph ofFas a subgraphandh(n;F) = max{E(G) :G∈H(n;F)}whereE(G) is the number of edges inG.In this paper we determineh(n;{θ4, θ5, θ7}) andh(n;θ7) for sufficiently odd largen. Our result confirms the conjecture made in [1] fork= 3.Scopu

Edge-maximal -free non-bipartite Hamiltonian graphs of odd order

Let (Formula presented.) denote the class of non-bipartite graphs on n vertices containing no (Formula presented.) -graph and (Formula presented.) Let (Formula presented.) denote the class of non-bipartite Hamiltonian graphs on n vertices containing no (Formula presented.) -graph and (Formula presented.) In this paper we determine (Formula presented.) by proving that for sufficiently large odd n, (Formula presented.) Furthermore, the bound is best possible. Our results confirm the conjecture made by Bataineh in 2007.Open Access funding provided by the Qatar National Library.Scopu

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions.

The PHENIX collaboration presents first measurements of low-momentum (0.41  GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (&gt;5  GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield