Some Uptake Studies of Metal Ions and the Formation of Cu₂0 Particles in Wool

This research programme is concerned with the uptake studies of Cu2+, Zn2+ and Mn2+ at different conditions, by merino wool fibres and also uptake studies of Cu2+ ions by chemically modified wool fibres. Cu2O particles and Cu complexes are formed within merino wool by an in situ reaction with sodium borohydride and thioglycoloic acid respectively. The d-block elements have the ability to bind chemically to certain functional groups present within the keratin protein of wool. The absorption of the Cu2+, Mn2+ and Zn2+ from solution by wool fibres under different conditions notably, time, temperature and initial concentration have been studied. The optimum temperature and reaction time to give highest absorption of the Cu2+ by the wool fibre was found to be 90 oC and one hour without modifying the nature of the wool, from a solution of Cu2+ concentration of 450 mg L-1. Cu2+ was found to give the greatest absorption by the wool fibres, whereas Zn2+ and Mn2+ were found to be absorbed the least. The absorption of Cu2+ ions increases with increasing temperature. At the higher temperature of 90 oC, the -S-S- bonds in the cystine amino acids break more readily, generating thiol and cysteic acid groups to bind with copper ions. The uptake of Cu2+ by ethylenediaminetetraacetic dianhydride (14 mg g-1 of wool) or thioglycolic acid (42.5 mg g-1 of wool) or sodium borohydride (41.8 mg g-1 of wool) treated merino wool fibres increases with respect to unmodified wool (8 mg g-1 of wool). NaBH4 treated merino wool reduces Cu2+ ions to Cu2O particles which form within the wool fibres by an in situ reaction. TGA treated merino wool provides additional functional groups to bind with copper ions and Cu2O particles also likely to be formed within TGA treated wool composites. The metal ions were absorbed into the fibres under various conditions and the extent of absorption was quantified. The form and binding of the Cu2O particles or Cu2+ ions onto the wool fibres are studied using UV-Visible, FTIR, XRD, SEM, EDS and TEM methods

Reward Learning from Demonstrations for Autonomous Earthmoving

With the increasing complexity of specific tasks, automation engineers look at various machine learning methods as opposed to methods that require laborious task specifications. Imitation learning methods have had varying degrees of success in the past. The main drawback of imitation learning methods is their inability to adapt to newer and ever-changing problems which hinder their flexibility. Reinforcement learning aims to solve the problem by learning instead based on a rewarding mechanism. However, a reward function needs to be determined prior to carrying out reinforcement learning. A range of methods have been used to define the reward functions, which are collectively referred to as inverse reinforcement learning methods. The objective of this research is to find a reward function for the autonomous earthmoving of a GIM Machine. In this study, different inverse reinforcement learning implementations were explored. Unsupervised perceptual rewards was selected considering that it is a sample efficient method that is easy to implement on a machine without good simulations for the environment and its interactions. Based on this method, the task is broken down into stages. Demonstration data and stage labels are used to train a stage classifier. When an observation is made, it is classified into one of the stages, and the reward is calculated as a function of the distance to the next stage. Unsupervised perceptual rewards is first used to obtain the reward function for the OpenAI Gym mountain car problem. Then q-learning is used to confirm that reinforcement learning can be applied effectively using the reward function obtained using this unsupervised perceptual rewards method. The method is then applied to demonstrations of the GIM Machine. Both low-level sensor data, as well as image features, have been used to calculate the reward. This research confirms the feasibility of using unsupervised perceptual rewards for reward function calculation and tests its robustness to changes in weather and lighting

Some Uptake Studies of Metal Ions and the Formation of Cu₂0 Particles in Wool

This research programme is concerned with the uptake studies of Cu2+, Zn2+ and Mn2+ at different conditions, by merino wool fibres and also uptake studies of Cu2+ ions by chemically modified wool fibres. Cu2O particles and Cu complexes are formed within merino wool by an in situ reaction with sodium borohydride and thioglycoloic acid respectively. The d-block elements have the ability to bind chemically to certain functional groups present within the keratin protein of wool. The absorption of the Cu2+, Mn2+ and Zn2+ from solution by wool fibres under different conditions notably, time, temperature and initial concentration have been studied. The optimum temperature and reaction time to give highest absorption of the Cu2+ by the wool fibre was found to be 90 oC and one hour without modifying the nature of the wool, from a solution of Cu2+ concentration of 450 mg L-1. Cu2+ was found to give the greatest absorption by the wool fibres, whereas Zn2+ and Mn2+ were found to be absorbed the least. The absorption of Cu2+ ions increases with increasing temperature. At the higher temperature of 90 oC, the -S-S- bonds in the cystine amino acids break more readily, generating thiol and cysteic acid groups to bind with copper ions. The uptake of Cu2+ by ethylenediaminetetraacetic dianhydride (14 mg g-1 of wool) or thioglycolic acid (42.5 mg g-1 of wool) or sodium borohydride (41.8 mg g-1 of wool) treated merino wool fibres increases with respect to unmodified wool (8 mg g-1 of wool). NaBH4 treated merino wool reduces Cu2+ ions to Cu2O particles which form within the wool fibres by an in situ reaction. TGA treated merino wool provides additional functional groups to bind with copper ions and Cu2O particles also likely to be formed within TGA treated wool composites. The metal ions were absorbed into the fibres under various conditions and the extent of absorption was quantified. The form and binding of the Cu2O particles or Cu2+ ions onto the wool fibres are studied using UV-Visible, FTIR, XRD, SEM, EDS and TEM methods.</p

Some Uptake Studies of Metal Ions and the Formation of Cu₂0 Particles in Wool

This research programme is concerned with the uptake studies of Cu2+, Zn2+ and Mn2+ at different conditions, by merino wool fibres and also uptake studies of Cu2+ ions by chemically modified wool fibres. Cu2O particles and Cu complexes are formed within merino wool by an in situ reaction with sodium borohydride and thioglycoloic acid respectively. The d-block elements have the ability to bind chemically to certain functional groups present within the keratin protein of wool. The absorption of the Cu2+, Mn2+ and Zn2+ from solution by wool fibres under different conditions notably, time, temperature and initial concentration have been studied. The optimum temperature and reaction time to give highest absorption of the Cu2+ by the wool fibre was found to be 90 oC and one hour without modifying the nature of the wool, from a solution of Cu2+ concentration of 450 mg L-1. Cu2+ was found to give the greatest absorption by the wool fibres, whereas Zn2+ and Mn2+ were found to be absorbed the least. The absorption of Cu2+ ions increases with increasing temperature. At the higher temperature of 90 oC, the -S-S- bonds in the cystine amino acids break more readily, generating thiol and cysteic acid groups to bind with copper ions. The uptake of Cu2+ by ethylenediaminetetraacetic dianhydride (14 mg g-1 of wool) or thioglycolic acid (42.5 mg g-1 of wool) or sodium borohydride (41.8 mg g-1 of wool) treated merino wool fibres increases with respect to unmodified wool (8 mg g-1 of wool). NaBH4 treated merino wool reduces Cu2+ ions to Cu2O particles which form within the wool fibres by an in situ reaction. TGA treated merino wool provides additional functional groups to bind with copper ions and Cu2O particles also likely to be formed within TGA treated wool composites. The metal ions were absorbed into the fibres under various conditions and the extent of absorption was quantified. The form and binding of the Cu2O particles or Cu2+ ions onto the wool fibres are studied using UV-Visible, FTIR, XRD, SEM, EDS and TEM methods

Dependence of Collision-Induced Mass Spectra of Protonated Michler’s Ketone on the Nature of LC-MS Mobile Phase

Michler’s ketone (MK) is a dimethylamino ketone that undergoes facile protonation under electrospray-ionization conditions to produce an ion of m/z 269. Initial LC-MS results showed that the collision-induced dissociation (CID) spectra of the m/z 269 ion depend heavily on the composition of the chromatographic mobile phase. Subsequent ion-mobility separation of the mass-selected m/z 269 ion revealed that protonated MK exists as two tautomeric forms. Moreover, the relative population of the two protomeric forms in the ion ensemble depends on the nature of the ambient molecules present in the atmospheric pressure ion source. For example, the ion-mobility arrival-time profile acquired from the mass-selected m/z 269 ion generated from an acetonitrile solution showed two peaks of near equal intensity. The peak with the shorter arrival time represented the O-protomer and that with the longer arrival time represented the N-protomer. However, when methanol or ammonia vapors were introduced to the ambient-pressure ion source, the intensity of the N-protomer peak decreased rapidly and that of the O-protomer signal soared until it became the dominant peak. When the introduction of methanol (or ammonia) vapors was stopped, the mobilogram signals gradually reverted back to their initial intensities. To rationalize this observation, we propose that the N-protomer of MK in the presence of methanol vapor undergoes transformation to the O-protomer by a Grotthuss-type mechanism via a methanol-based solvent bridge

Conditional inactivation of Npy1r gene in mice induces behavioural inflexibility and orbitofrontal cortex hyperactivity that are reversed by escitalopram

Cognitive flexibility is the ability to rapidly adapt established patterns of behaviour in the face of changing circumstance and depends critically on the orbitofrontal cortex (OFC). Impaired flexibility also results from altered serotonin transmission in the OFC. The Y1 (Y1R) and Y5 (Y5R) receptors for neuropeptide Y (NPY) colocalize in several brain regions and have overlapping functions in regulating cognition and emotional behaviour. The targeted disruption of gene encoding Y1R (Npy1r gene) in Y5R containing neurons (Npy1rY5R-/- mice) increases anxiety-like behaviour and spatial reference memory. Here we used the same conditional system to analyse whether the coordinated expression of the Y1R and Y5R might be required for behavioural flexibility in reversal learning tasks, OFC serotoninergic tone and OFC neural activity, as detected by immunohistochemical quantification of the immediate-early gene, c-Fos. In addition, we investigated whether the acute treatment of Npy1rY5R-/- mice with the selective serotonin reuptake inhibitor escitalopram affected behavioural flexibility and OFC c-Fos expression. Npy1rY5R-/- male mice exhibit an impairment in performing the reversal task of the Morris water maze and the water T-maze but normal spatial learning, working memory and sociability, compared to their control siblings. Furthermore, Npy1rY5R-/- male mice display decreased 5-hydroxytriptamine (5-HT) positive fibres and increased baseline neural activity in OFC. Importantly, escitalopram normalizes OFC neural activity and restores behavioural flexibility of Npy1rY5R-/- male mice. These findings suggest that the inactivation of Y1R in Y5R containing neurons increases pyramidal neuron activity and dysregulates serotoninergic tone in OFC, whereby contributing to reversal learning impairment

Multiple origins and modularity in the spatiotemporal emergence of cerebellar astrocyte heterogeneity.

The morphological, molecular, and functional heterogeneity of astrocytes is under intense scrutiny, but how this diversity is ontogenetically achieved remains largely unknown. Here, by quantitative in vivo clonal analyses and proliferation studies, we demonstrate that the major cerebellar astrocyte types emerge according to an unprecedented and remarkably orderly developmental program comprising (i) a time-dependent decline in both clone size and progenitor multipotency, associated with clone allocation first to the hemispheres and then to the vermis(ii) distinctive clonal relationships among astrocyte types, revealing diverse lineage potentials of embryonic and postnatal progenitors; and (iii) stereotyped clone architectures and recurrent modularities that correlate to layer-specific dynamics of postnatal proliferation/differentiation. In silico simulations indicate that the sole presence of a unique multipotent progenitor at the source of the whole astrogliogenic program is unlikely and rather suggest the involvement of additional committed components