Effect of yeast extract and chitosan on shoot proliferation, morphology and antioxidant activity of Curcuma mangga in vitro plantlets

This paper reported the effect of yeast extract and chitosan with combination of yeast extract on the growth and morphological changes and production of phenolics in the in vitro plantlets of Curcuma mangga. Yeast extract did not show any effect on the biomass and shoot proliferation of in vitro plantlets. However, the plantlets showed morphological abnormality when exposed to higher concentration of yeast extract (3.5 mgL-1 and above) supplemented into the culture medium. Plantlets cultured in media supplemented with 3.5 and 5.0 mgL-1 of yeast extract showed higher radical scavenging activity (RSA) which also indicated that stress induced by yeast extract might elicit the production of secondary metabolites which acted as free radical scavenger in 1,1-diphenyl-2- picrylhydrazyl (DPPH) assay. The plantlets treated with different concentration of chitosan combined with 3.5 mgL-1 of yeast extract affected the biomass of C. mangga. The plantlets that were cultured in media supplemented with 150 mgL-1 of chitosan combined and 3.5 mgL-1 of yeast extract showed higher RSA towards DPPH as compared to the other treatments. Kinetic of DPPH free RSA from C. mangga extract was considered slow as compared to quercetin and the correlation between total phenolic content and RSA was poor (R2 = 0.2293) for yeast extract and (R2 = 0.0373) for chitosan combination with yeast extract. This indicated that the presence of phenolic compounds in the extracts were not the major factor contributing to the anti-oxidative activity of C. mangga.Key words: Curcuma mangga, in-vitro, elicitor, phenolics, anti-oxidative activities

Entropic Interactions in Suspensions of Semi-Flexible Rods: Short-Range Effects of Flexibility

We compute the entropic interactions between two colloidal spheres immersed in a dilute suspension of semi-flexible rods. Our model treats the semi-flexible rod as a bent rod at fixed angle, set by the rod contour and persistence lengths. The entropic forces arising from this additional rotational degree of freedom are captured quantitatively by the model, and account for observations at short range in a recent experiment. Global fits to the interaction potential data suggest the persistence length of fd-virus is about two to three times smaller than the commonly used value of $2.2 \mu {m}$.Comment: 4 pages, 5 figures, submitted to PRE rapid communication

Performance Pay, the Marriage Market and Rising Income Inequality in Taiwan

Taiwan expanded its college access significantly over the past two decades by converting 2-year junior colleges to 4-year colleges and relaxing entrance standards. The share of college graduates in the 22–24 years old population rose from 12 to 71% between 1990 and 2014. This should have suppressed returns to schooling and lowered household income inequality. Instead, Taiwan’s Gini coefficient rose. We show that rising use of performance pay and positive assortative mating in the marriage market jointly increase the household income inequality by 46.5% between 1980 and 2014. Our results suggest that uneven quality of the most recent cohorts of college graduates led to two sources of rising household income inequality: the increased use of bonus pay which increases residual inequality among college graduates; and matching on unobserved skills in the marriage market which increases inequality among married couples

Revenue-driven scheduling in drone delivery networks with time-sensitive service level agreements

Drones are widely anticipated to be used for commercial service deliveries, with potential to contribute to economic growth, estimated at £42 billion in the UK alone by the year 2030. Alongside air traffic control algorithms, drone-based courier services will have to make intelligent decisions about how to deploy their limited resources in order to increase profits. This paper presents a new scheduling algorithm for optimising the revenue of a drone courier service provider in these highly utilised time-sensitive service delivery systems. The first input to the algorithm is a monotonically decreasing value over time function which describes the service level agreement between the service provider and its customers. The second is the anticipated drone flight-time duration distribution. Our results show that the newly-developed scheduling algorithm, Least Lost Value, inspired by concepts for real-time computational workload processing, is able to successfully route drones to extract increased revenue to the service provider in comparison with two widely-used scheduling algorithms: First Come First Served and Shortest Job First, in terms of realised revenue

An Audit of UK Hospital Doctors’ Knowledge and Experience of Myalgic Encephalomyelitis

Background and Objectives: There is some evidence that knowledge and understanding of ME among doctors is limited. Consequently, an audit study was carried out on a group of hospital doctors attending a training event to establish how much they knew about ME and their attitudes towards it. Materials and Methods: Participants at the training event were asked to complete a questionnaire, enquiring about prior knowledge and experience of ME and their approaches to diagnosis and treatment. A total of 44 completed questionnaires were returned. Responses were tabulated, proportions selecting available options determined, 95% confidence limits calculated, and the significance of associations determined by Fisher’s exact test. Results: Few respondents had any formal teaching on ME, though most had some experience of it. Few knew how to diagnose it and most lacked confidence in managing it. None of the respondents who had had teaching or prior experience of ME considered it a purely physical illness. Overall, 91% of participants believed ME was at least in part psychological. Most participants responded correctly to a series of propositions about the general epidemiology and chronicity of ME. There was little knowledge of definitions of ME, diagnosis, or of clinical manifestations. Understanding about appropriate management was very deficient. Similarly, there was little appreciation of the impact of the disease on daily living or quality of life. Where some doctors expressed confidence diagnosing or managing ME, this was misplaced as they were incorrect on the nature of ME, its diagnostic criteria and its treatment. Conclusion: This audit demonstrates that most doctors lack training and clinical expertise in ME. Nevertheless, participants recognised a need for further training and indicated a wish to participate in this. It is strongly recommended that factually correct and up-to-date medical education on ME be made a priority at undergraduate and postgraduate levels. It is also recommended that this audit be repeated following a period of medical education

Quasinormal Modes in three-dimensional time-dependent Anti-de Sitter spacetime

The massless scalar wave propagation in the time-dependent BTZ black hole background has been studied. It is shown that in the quasi-normal ringing both the decay and oscillation time-scales are modified in the time-dependent background.Comment: 8 pages and 7 figure

Turbulent mixing of particles under tidal bores: An experimental analysis

A tidal bore develops in an estuary when the tidal range exceeds 4.5-6 m and the estuarine bathymetry amplifies the tidal wave. The bore is an abrupt rise in water depth associated with a discontinuity in velocity and pressure fields at the front. Herein the free-surface properties and the turbulent mixing of light-weight particles were investigated during the passage of tidal bores. The free-surface properties were recorded using a non-intrusive technique, while particle tracking was performed under undular and breaking bores. A basic result was the identification of a broad spectrum of particle trajectories, linked with the existence of large-scale vortical structures. These turbulent structures were responsible for the vertical water mixing as a tidal bore propagates upstream in an estuary. The large-scale eddies were also responsible for the rapid longitudinal dispersion of particulates, such as fish eggs, with some form of preferential motion, depending upon the particle's vertical elevation

Dirac Cosmology and the Acceleration of the Contemporary Universe

A model is suggested to unify the Einstein GR and Dirac Cosmology. There is one adjusted parameter $b_2$ in our model. After adjusting the parameter $b_2$ in the model by using the supernova data, we have calculated the gravitational constant $\bar G$ and the physical quantities of $a(t)$, $q(t)$ and $\rho_r(t)/ \rho_b(t)$ by using the present day quantities as the initial conditions and found that the equation of state parameter $w_{\theta}$ equals to -0.83, the ratio of the density of the addition creation $\Omega_{\Lambda}=0.8$ and the ratio of the density of the matter including multiplication creation, radiation and normal matter $\Omega_m =0.2$ at present. The results are self-consistent and in good agreement with present knowledge in cosmology. These results suggest that the addition creation and multiplication creation in Dirac cosmology play the role of the dark energy and dark matter.Comment: 13 pages, 8 figure