PreHevbrio for adult hepatitis B vaccination : evidence to recommendation and GRADE

2-HepWG-weng-508.pdf20221099

Weng v. Atty Gen USA

Agenc

Global stability in a regulated logistic growth model

Trofimchuk, S. Instituto de Matemática y Física, Universidad de Talca, Casilla 747, Talca, Chile.We investigate global stability of the regulated logistic growth model (RLC) n'(t) = rn(t)(1-n(t-h)/K-cu(t)), u'(t) = -au(t)+bn(t-h). It was proposed by Gopalsamy and Weng [1, 2] and studied recently in [4, 5, 6, 9]. Compared with the previous results, our stability condition is of different kind and has the asymptotical form. Namely, we prove that for the fixed parameters K and mu = bcK/a (which determine the levels of steady states in the delayed logistic equation n'(t) rn(t)(1 - n(t - h)/K) and in RLG) and for every hr < root 2 the regulated logistic growth model is globally stable if we take the dissipation parameter a sufficiently large. On the other hand, studying the local stability of the positive steady state, we observe the improvement of stability for the small values of a: in this case, the inequality rh < pi(1 + mu)/2 guaranties such a stabilit

Xiu Weng v. Atty Gen USA

Agenc

Production of L-Lactic Acid Using Various Carbon Sources by Enterococcus Gallinarum EB1

This study reports on the production of L-lactic acid using a locally isolated bacteria. Bacteria were screened and isolated from POME sludge, kitchen refuse, leachate biomass, soil and fermented milk. Five bacteria shown positive result in the preliminary test and only one bacteria which was isolated from POME effluent shown the highest lactic acid production. Using shake flask culture, 18.0 g/L of L-lactic acid was produced from 20.0 g/L glucose . The selectivity of lactic acid produced by the bacteria was 99.8% compared to other organic acids. This indicated that the bacteria can be use for the production of L-Lactic acid. Using the BIOLOG system, the bacteria was identified belonging to the family Enterococcus gallinarum and named as Enterococcus gallinarum EB1. Morphologically, the bacteria is cocci-shaped and in chains or grouped. The optimal growth condition for the bacteria was at pH 6 and temperature 37°C where at this condition, the bacteria able to produced highest lactic acid yield at 1.9 g/g using glucose as substrate. The organic acids composition was dependent on the pH and temperature. In an anaerobic batch fermentation to produce lactic acid using four types of substrates (glucose, kitchen refuse, sago starch and cooked rice), the highest lactic acid production was 45.0 g/L. From the experiment, the bacteria was able to convert the kitchen refuse into lactic acid at 45.2 g/L and small amount of other organic acids. The comparison was also done with other substrates to show that the bacteria able to utilise kitchen refuse in lactic acid production. In the recovery process of lactic acid, the best method was to use H₂SO₄ prior to evaporation at 90°C with 3mmHg vacuum pressure. H₂SO₄ able to free lactic acid from lactate salts formed in the fermentation because the use of NaOH to control pH in the bioreactor throughout the fermentation process. The evaporation method able to achieved 86.76% lactic acid recovery yield from the fermentation broth. It was the highest recovery yield recorded in evaporation compared to other evaporation method with additional of solvents (propanol and butanol) with temperature at 90°C and pressure around 3mmHg

Potential vorticity index

Using standard data analysis techniques, researchers explore the links between disturbance growth and quasi-geostrophic potential vorticity (PV) gradients; appearance and disappearance of cutoff lows and blocking highs and their relation to a zonal index (properly defined in terms of PV); and teleconnections between different flow patterns and their relation to the zonal index. It was found that the PV index and the eddy index correlate better than a zonal index (defined by zonal wind) and the eddy index. In the frequency domain there are three frequencies (.03, .07 and .17 cpd (cycle per day) corresponding to periods of 33, 14 and 6 days) at which PV index and the eddy index exhibit local maxima. The high correlation found at periods of 33 days is mainly due to eddy activity at high latitudes while the local correlation maxima found at the shorter periods are mainly due mid-latitude eddy activity. The correlation between the PV index and the geopotential height anomaly at 500 mb, at each grid point in the Northern Hemisphere, shows the existence of most of the teleconnection patterns summarized by Wallace and Gutzler (1981): the North Atlantic Oscillation, the North Pacific Oscillation, and the Pacific/North American patterns. Results show that the Isentropic Potential Vorticity (IPV) analysis can be a very useful and powerful tool when used to understand the dynamics of several large scale atmospheric systems. Although the data are limited to only one winter, and it is difficult to assess the statistical significance of the correlation coefficients presented here, the results are encouraging from physical viewpoint

Dynamics of baroclinic wave systems

The research carried out in the past year dealt with nonlinear baroclinic wave dynamics. The model consisted of an Eady baroclinic basic state and uneven Elkman dissipation at the top and bottom boundaries with/without slopes. The method of solution used a truncated spectral expansion with three zonal waves and one or two meridional modes. Numerical experiments were performed on synoptic scale waves or planetary scale waves with/without wave-wave interaction