11 resultados para Tripartite entanglement
em Aston University Research Archive
Resumo:
A scheme of teleportation of an arbitrary two-particle state is presented when two pairs of entangled particles are used as quantum channels. After the Bell state measurements are operated by the sender, the original state with deterministic probability can be reconstructed by the receiver when a corresponding unitary transformation is followed.
Resumo:
A new poly(ethylene oxide)-tetraphenylalanine polymer-peptide conjugate has been prepared via a “click” reaction between an alkyne-modified peptide and an azide-terminated PEO oligomer. Self-assembled nanotubes are formed after dialysis of a THF solution of this polymer-peptide conjugate against water. The structure of these nanotubes has been probed by circular dichroism, IR, TEM, and SAXS. From these data, it is apparent that self-assembly involves the formation of antiparallel ß-sheets and p-p-stacking. Nanotubes are formed at concentrations between 2 and 10 mg mL-1. Entanglement between adjacent nanotubes occurs at higher concentrations, resulting in the formation of soft hydrogels. Gel strength increases at higher polymer-peptide conjugate concentration, as expected.
Resumo:
Tripartite neuropsychologies have featured through two and half millennia of Western thought. They received a modern airing in Paul MacLean's well-known text The Triune Brain. This paper examines the origin of these triune psychophysiologies. It is argued that the first such psychophysiology was developed in the fifth century BCE in the Republic and its Pythagorean sequel, the Timaeus. Aristotle, Plato's pupil and colleague, developed a somewhat similar theory, though this time based on his exhaustive biological researches. Finally, a generation later, Herophilus and Erasistratus at the Alexandrian Museum put together a more anatomically informed tripartite theory that, somewhat modified by Galen in the second century AD, remained the prevailing orthodoxy for nearly fifteen hundred years until it was overturned by the great figures of the Renaissance. Nonetheless, as already mentioned, the notion that human neuropsychology is somehow best thought of as having a tripartite structure has remained remarkably resilient and has reappeared time and again in modern and early modern times. This paper investigates its origins and suggests that it is perhaps now time to move on.
Resumo:
This work focuses on translated political speeches made by Canadas prime minister during times of national crises. Delivered orally in both English and French, this translation-based political discourse is examined in a tripartite manner, offering the reader contextualisation of the corpus researched; description of the translation shifts encountered; and interpretation of the discourse varies greatly depending on the era observed. Since the latter half of the 20th century, for instance, different text types have been assigned to different categories of translators. As for translative shifts revealed in the corpus, they have been categorised as either paratextual or textual divergences. Paratextual differences indicate that the Canadian prime ministers national statements in English and French do not necessarily seek to portray symmetry between what is presented in each language. Each version of a national speech thus retains a relative degree of visual autonomy. In sum, accumulated instances of paratextual divergence suggest an identifiable paratextual strategy, whereby translation contributes to the illusion that there is only one federal language: the readers. The deployment of this paratextual strategy obscures the fact that such federal expression occurs in two official languages. The illusion of monolingualism generates two different world views one for each linguistic community. Similarly, another strategy is discerned in the analysis of translative textual shifts a textual strategy useful in highlighting some of the power struggles inherent in translated federal expression. Textual interpretation of data identifies four federal translation tendencies: legitimisation and characterisation of linguistic communities; dislocation of the speech-event; neutralisation of (linguistic) territory; and valorisation of federalism.
Resumo:
Astrocytes in the somatosensory ventrobasal (VB) thalamus of rats respond to glutamatergic synaptic input with metabotropic glutamate receptor (mGluR) mediated intracellular calcium ([Ca²?](i)) elevations. Astrocytes in the VB thalamus also release the gliotransmitter (GT) glutamate in a Ca²?-dependent manner. The tripartite synapse hypothesis posits that astrocytic [Ca²?](i) elevations resulting from synaptic input releases gliotransmitters that then feedback to modify the synapse. Understanding the dynamics of this process and the conditions under which it occurs are therefore important steps in elucidating the potential roles and impact of GT release in particular brain activities. In this study, we investigated the relationship between VB thalamus afferent synaptic input and astrocytic glutamate release by recording N-methyl-D-aspartate (NMDA) receptor-mediated slow inward currents (SICs) elicited in neighboring neurons. We found that Lemniscal or cortical afferent stimulation, which can elicit astrocytic [Ca²?](i) elevations, do not typically result in the generation of SICs in thalamocortical (TC) neurons. Rather, we find that the spontaneous emergence of SICs is largely resistant to acute afferent input. The frequency of SICs, however, is correlated to long-lasting afferent activity. In contrast to short-term stimulus-evoked GT release effects reported in other brain areas, astrocytes in the VB thalamus do not express a straightforward input-output relationship for SIC generation but exhibit integrative characteristics.
Resumo:
This paper seeks to advance research and practice related to the role of employers in all stages of the assessment process of work-based learning (WBL) within a tripartite relationship of higher education institution (HEI), student and employer. It proposes a research-informed quality enhancement framework to develop good practice in engaging employers as partners in assessment. The Enhancement Framework comprises three dimensions, each of which includes elements and questions generated by the experiences of WBL students, HEI staff and employers. The three dimensions of the Enhancement Framework are: 1. ‘premises of assessment’ encompassing issues of learning, inclusion, standards and value; 2. ‘practice’, encompassing stages of assessment made up of course design, assessment task, responsibilities, support, grading and feedback; 3. ‘communication of assessment’ with the emphasis on role clarity, language and pathways. With its prompt questions, the Enhancement Framework may be used as a capacity-building tool for promoting, sustaining, benchmarking and evaluating productive dialogue and critical reflection about assessment between WBL partners. The paper concludes by emphasising the need for professional development as well as policy and research development, so that assessment in WBL can more closely correspond to the potentially transformative nature of the learning experience.
Resumo:
The primary aim of this research is to understand what constitutes management accounting and control (MACs) practice and how these control processes are implicated in the day to day work practices and operations of the organisation. It also examines the changes that happen in MACs practices over time as multiple actors within organisational settings interact with each other. I adopt a distinctive practice theory approach (i.e. sociomateriality) and the concept of imbrication in this research to show that MACs practices emerge from the entanglement between human/social agency and material/technological agency within an organisation. Changes in the pattern of MACs practices happens in imbrication processes which are produced as the two agencies entangle. The theoretical approach employed in this research offers an interesting and valuable lens which seeks to reveal the depth of these interactions and uncover the way in which the social and material imbricate. The theoretical framework helps to reveal how these constructions impact on and produce modifications of MACs practices. The exploration of the control practices at different hierarchical levels (i.e. from the operational to middle management and senior level management) using the concept of imbrication process also maps the dynamic flow of controls from operational to top management and vice versa in the organisation. The empirical data which is the focus of this research has been gathered from a case study of an organisation involved in a large vertically integrated palm oil industry company in Malaysia specifically the refinery sector. The palm oil industry is a significant industry in Malaysia as it contributed an average of 4.5% of Malaysian Gross Domestic Product, over the period 1990 -2010. The Malaysian palm oil industry also has a significant presence in global food oil supply where it contributed 26% of the total oils and fats global trade in 2010. The case organisation is a significant contributor to the Malaysian palm oil industry. The research access has provided an interesting opportunity to explore the interactions between different groups of people and material/technology in a relatively heavy process food industry setting. My research examines how these interactions shape and are shaped by control practices in a dynamic cycle of imbrications over both short and medium time periods.
Resumo:
Polymer beads have attracted considerable interest for use in catalysis, drug delivery, and photonics due to their particular shape and surface morphology. Electrospinning, typically used for producing nanofibers, can also be used to fabricate polymer beads if the solution has a sufficiently low concentration. In this work, a novel approach for producing more uniform, intact beads is presented by electrospinning self-assembled block copolymer (BCP) solutions. This approach allows a relatively high polymer concentration to be used, yet with a low degree of entanglement between polymer chains due to microphase separation of the BCP in a selective solvent system. Herein, to demonstrate the technology, a well-studied polystyrene-poly(ethylene butylene)–polystyrene triblock copolymer is dissolved in a co-solvent system. The effect of solvent composition on the characteristics of the fibers and beads is intensively studied, and the mechanism of this fiber-to-bead is found to be dependent on microphase separation of the BCP.
Resumo:
There is a widespread sense that the Front National (FN) came of age in 2014 as a challenger for power in France. The municipal and European elections appeared to herald a transformation in the party's development and prospects, demonstrating its capacity to compete as a major player at subnational and supranational levels following strong performances at the national level in the presidential and legislative elections of 2012. This article takes a critical view of that assessment. It argues that the FN in 2014 made significant progress but that the apparent surge of support for the party in these elections belies fundamental weaknesses in the depth and range of its electoral capacities and in its prospects for transforming itself into a party of government. These weaknesses were again evident in the departmental elections of 2015, confirming that the FN has not succeeded in ending bipolarisation and imposing a genuinely tripartite structure on French politics. Far from being the 'first party of France' and 'at the gates of power', the FN is still consigned primarily to a role of spoiler, with its progression stalled by institutional obstacles, electoral limitations and a political containment which it remains powerless to overcome.
Resumo:
There is currently great scientific and medical interest in the potential of tissue grown from stem cells. These cells present opportunities for generating model systems for drug screening and toxicological testing which would be expected to be more relevant to human outcomes than animal based tissue preparations. Newly realised astrocytic roles in the brain have fundamental implications within the context of stem cell derived neuronal networks. If the aim of stem cell neuroscience is to generate functional neuronal networks that behave as networks do in the brain, then it becomes clear that we must include and understand all the cellular components that comprise that network, and which are important to support synaptic integrity and cell to cell signalling. We have shown that stem cell derived neurons exhibit spontaneous and coordinated calcium elevations in clusters and in extended processes, indicating local and long distance signalling (1). Tetrodotoxin sensitive network activity could also be evoked by electrical stimulation. Similarly, astrocytes exhibit morphology and functional properties consistent with this glial cell type. Astrocytes also respond to neuronal activity and to exogenously applied neurotransmitters with calcium elevations, and in contrast to neurons, also exhibited spontaneous rhythmic calcium oscillations. Astroctyes also generate propagating calcium waves that are gap junction and purinergic signalling dependent. Our results show that stem cell derived astrocytes exhibit appropriate functionality and that stem cell neuronal networks interact with astrocytic networks in co-culture. Using mixed cultures of stem cell derived neurons and astrocytes, we have also shown both cell types also modulate their glucose uptake, glycogen turnover and lactate production in response to glutamate as well as increased neuronal activity (2). This finding is consistent with their neuron-astrocyte metabolic coupling thus demonstrating a tractable human model, which will facilitate the study of the metabolic coupling between neurons and astrocytes and its relationship with CNS functional issues ranging from plasticity to neurodegeneration. Indeed, cultures treated with oligomers of amyloid beta 1-42 (Aβ1-42) also display a clear hypometabolism, particularly with regard to utilization of substrates such as glucose (3). Both co-cultures of neurons and astrocytes and purified cultures of astrocytes showed a significant decrease in glucose uptake after treatment with 2 and 0.2 μmol/L Aβ at all time points investigated (p <0.01). In addition, a significant increase in the glycogen content of cells was also measured. Mixed neuron and astrocyte co-cultures as well as pure astrocyte cultures showed an initial decrease in glycogen levels at 6 hours compared with control at 0.2 μmol/L and 2 μmol/L P <0.01. These changes were accompanied by changes in NAD+/NADH (P<0.05), ATP (P<0.05), and glutathione levels (P<0.05), suggesting a disruption in the energy-redox axis within these cultures. The high energy demands associated with neuronal functions such as memory formation and protection from oxidative stress put these cells at particular risk from Aβ-induced hypometabolism. As numerous cell types interact in the brain it is important that any in vitro model developed reflects this arrangement. Our findings indicate that stem cell derived neuron and astrocyte networks can communicate, and so have the potential to interact in a tripartite manner as is seen in vivo. This study therefore lays the foundation for further development of stem cell derived neurons and astrocytes into therapeutic cell replacement and human toxicology/disease models. More recently our data provides evidence for a detrimental effect of Aβ on carbohydrate metabolism in both neurons and astrocytes. As a purely in vitro system, human stem cell models can be readily manipulated and maintained in culture for a period of months without the use of animals. In our laboratory cultures can be maintained in culture for up to 12 months months thus providing the opportunity to study the consequences of these changes over extended periods of time relevant to aspects of the disease progression time frame in vivo. In addition, their human origin provides a more realistic in vitro model as well as informing other human in vitro models such as patient-derived iPSC.
Resumo:
The departmental elections of March 2015 redrew the French political landscape, setting the new terms of electoral competition in advance of the regional elections of December 2015 and, more critically, the presidential election of April–May 2017. These elections saw the far-right National Front (FN) come top in both rounds only to be outmanoeuvred by the mainstream parties and prevented from winning a single department. As a case study in vote–seat distortion, the elections highlighted a voting system effective in keeping the FN out of executive power but deficient in terms of democratic representation and inadequate as a response to the new tripartite realities of France's changing political landscape.