Naresuan University Journal
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State-led Education for Democratic Socialism: Venezuela's Education Missions
No full textVenezuela’s ‘Bolivarian Revolution’ is conceptualised as an anti-neoliberal project that aims to promote fundamental changes in the configuration of political power via processes of state-grassroots collaboration. Central to this process is an emphasis on the key role of education in the development of a 21st Century socialism based on principles of protagonist participation and democratic socialism. While many education policies claim to encourage the participation of citizens and the idea of the ‘democratic person’, and have used the language of liberation, empowerment and justice, very few state-led initiatives have shown a clear commitment to creating spaces and opportunities whereby people can develop critical consciousness and become active agents in the restructuring of state-society relations. While many see developing critical literacy in a state-based education system as an oxymoron, the current process of state-promoted social change in Venezuela offers a rare opportunity to examine how state-sponsored education to promote protagonist, participatory democracy might develop in practice. This article therefore uses the Venezuelan case to examine the extent to which discourse has been put into practice, thereby shedding light on the possibility of state-grassroots collaboration to promote education for critical consciousness and structural change
A sense of balance: Experimental investigation and modeling of a malonyl-CoA sensor in Escherichia coli
No full textProduction of value-added chemicals in microorganisms is regarded as a viable alternative to chemical synthesis. In the past decade, several engineered pathways producing such chemicals, including plant secondary metabolites in microorganisms have been reported; upscaling their production yields, however, was often challenging. Here, we analyze a modular device designed for sensing malonyl-CoA, a common precursor for both fatty acid and flavonoid biosynthesis. The sensor can be used either for high-throughput pathway screening in synthetic biology applications or for introducing a feedback circuit to regulate production of the desired chemical. Here, we used the sensor to compare the performance of several predicted malonyl-CoA producing pathways, and validated the utility of malonyl-CoA reductase and malonate-CoA transferase for malonyl-CoA biosynthesis. We generated a second-order dynamic linear model describing the relation of the fluorescence generated by the sensor to the biomass of the host cell representing a filter/amplifier with a gain that correlates with the level of induction. We found the time constants describing filter dynamics to be independent of the level of induction but distinctively clustered for each of the production pathways, indicating the robustness of the sensor. Moreover, by monitoring the effect of the copy-number of the production plasmid on the dose-response curve of the sensor, we managed to coarse-tune the level of pathway expression to maximize malonyl-CoA synthesis. In addition, we provide an example of the sensor's use in analyzing the effect of inducer or substrate concentrations on production levels. The rational development of models describing sensors, supplemented with the power of high-throughput optimization provide a promising potential for engineering feedback loops regulating enzyme levels to maximize productivity yields of synthetic metabolic pathways
The phase behaviour of mixed saturated and unsaturated monoglycerides in hydrophobic system
No full textLyotropic liquid crystals are formed on the dissolution of most surfactants in water as represented by regions on the phase diagram, and are more common than micellar solutions. Monoglycerides with saturated or unsaturated fatty acids are one of the most commonly used food surfactants. While there is considerable interest in the behaviour of monoglycerides mixed with oils (particularly triglycerides), limited information is available regarding the phase behaviour of such systems. We have examined the phase behaviour of mixed saturated and unsaturated monoglycerides1:1 (by weight) together with different oils systems. The main technique employed was X-ray diffraction, supplemented by optical microscopy, proton nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). Our results suggest that six phases (L2, α-gel phase, sub α- phase, β1 and oil crystallisation phase (β` for palm oil or β2 for miglyol oil or olive oil) were observed for G50/oil mixture. Furthermore, this paper proves that miglyol and palm oil incorporate into α-gel phase of G50. In contrast, olive oil dose not incorporate into α-gel phase of G50
Monitoring Ras Interactions with the Nucleotide Exchange Factor Sos using Site-specific NMR Reporter Signals and Intrinsic Fluorescence
No full textThe activity of Ras is controlled by the inter-conversion between GTP- and GDP-bound forms, partly regulated by the binding of the guanine nucleotide exchange factor Son of Sevenless (Sos). The details of Sos binding, leading to nucleotide exchange and subsequent dissociation of the complex, are not completely understood. Here, we used uniformly [15N]-labeled Ras, as well as [13C-methyl-M,I]-labeled Sos, for observing site-specific details of Ras:Sos interactions in solution. Binding of various forms of Ras (loaded with GDP and mimics of GTP, or nucleotide-free) at the allosteric and catalytic sites of Sos was comprehensively characterized, by monitoring signal perturbations in the NMR spectra. The overall affinity of binding between these protein variants, as well as their selected functional mutants, was also investigated using intrinsic fluorescence. The data supports a positive feedback activation of Sos by Ras-GTP, with Ras-GTP binding as a substrate for the catalytic site of activated Sos more weakly than Ras-GDP, suggesting that Sos should actively promote unidirectional GDP→GTP exchange on Ras, in preference of passive homonucleotide exchange. Ras-GDP weakly binds to the catalytic, but not to the allosteric site of Sos. This confirms that Ras-GDP cannot properly activate Sos at the allosteric site. The novel site-specific assay described may be useful for design of drugs aimed at perturbing Ras:Sos interactions
Supplemental Blue LED Lighting Array to Improve the Signal Quality in Hyperspectral Imaging of Plants
No full textHyperspectral imaging systems used in plant science or agriculture often have suboptimal signal-to-noise ratio in the blue region (400–500 nm) of the electromagnetic spectrum. Typically there are two principal reasons for this effect, the low sensitivity of the imaging sensor and the low amount of light available from the illuminating source. In plant science, the blue region contains relevant information about the physiology and the health status of a plant. We report on the improvement in sensitivity of a hyperspectral imaging system in the blue region of the spectrum by using supplemental illumination provided by an array of high brightness light emitting diodes (LEDs) with an emission peak at 470 nm
At the crossroads between Asia and Africa: paleobiogeographic significance of a new ctenodactyline rodent from the Miocene of Lebanon
No full textSpin-gap study of the spin-½ J<sub>1</sub><i>-</i>J<sub>2</sub> model on the triangular lattice
No full textWe use the coupled cluster method implemented at high orders of approximation to study the spin- -- model on the triangular lattice with Heisenberg interactions between nearest-neighbour and next-nearest-neighbour pairs of spins, with coupling strengths J_{1}>0 and J_{2} \equiv \kappa J_{1} >0, respectively. In the window we find that the 3-sublattice 120 N\'{e}el-ordered and 2-sublattice 180 stripe-ordered antiferromagnetic states form the stable ground-state phases in the regions \kappa <\kappa^{c}_{1} = 0.060(10) and \kappa > \kappa^{c}_{2} = 0.165(5), respectively. The spin-triplet gap is found to vanish over essentially the entire region \kappa^{c}_{1} <\kappa <\kappa^{c}_{2} of the intermediate phase
Deliverable 1.3 "Monitoring Aspects and Benefits" and Deliverable 2.1 "EVs and PV: Literature review and initial modelling"
No full textThis report presents a quantitative assessment of the benefits from adopting different levels of monitoring considering location, sampling and data latency. This report is also presents a summary of the literature review and current pilot projects investigating the control of EV and PV systems
The Effect of Formulation on Microbicide Potency and Mitigation of the Development of Bacterial Insusceptibility.
No full textRisk assessments into the potential for microbicides to select for reduced bacterial susceptibility have been based largely on data generated through the exposure of bacteria to microbicides in aqueous solution. Since microbicides are normally formulated with multiple excipients, we have investigated the effect of formulation on antimicrobial activity and the induction of bacterial insusceptibility. The susceptibilities of 8 species of bacteria (7 genera) were determined before and after repeated exposure (14 passages) using a previously validated gradient plating system, to the microbicides benzalkonium chloride, benzisothiozolinone, chlorhexidine, didecyldimethyl ammonium chloride, DMDM-hydantoin, polyhexamethylene biguanide, thymol and triclosan in aqueous solution (non-formulated) and in formulation with excipients often deployed in consumer products. Susceptibilities were also assessed following an additional 14 passages without microbicide to determine the stability of any susceptibility changes. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were on average 11-fold lower for formulated vs. non-formulated microbicides. After exposure to the antimicrobial compounds, of 72 combinations of microbicide and bacterium, there were 19 ≥4- fold (mean 8-fold) increases in MIC for non-formulated and 8 ≥4-fold (mean 2-fold) increases in MIC for formulated microbicides. Furthermore, there were 20 ≥4-fold increases in MBC (mean 8-fold) for non-formulated and 10 ≥4-fold (mean 2-fold) increases in MBC for formulated microbicides. Susceptibility decreases fully or partially reverted back to pre- exposure values for 49% of MICs and 72% of MBCs after further passage. In summary, formulated microbicides exhibited greater antibacterial potency than unformulated actives and susceptibility decreases following repeated exposure were lower in frequency and extent