A Magnetic Resonance Realization of Decoherence-Free Quantum Computation

We report the realization, using nuclear magnetic resonance techniques, of the first quantum computer that reliably executes an algorithm in the presence of strong decoherence. The computer is based on a quantum error avoidance code that protects against a class of multiple-qubit errors. The code stores two decoherence-free logical qubits in four noisy physical qubits. The computer successfully executes Grover's search algorithm in the presence of arbitrarily strong engineered decoherence. A control computer with no decoherence protection consistently fails under the same conditions.Comment: 5 pages with 3 figures, revtex4, accepted by Physical Review Letters; v2 minor revisions to conten

Robust and fragile Werner states in the collective dephasing

We investigate the concurrence and Bell violation of the standard Werner state or Werner-like states in the presence of collective dephasing. It is shown that the standard Werner state and certain kinds of Werner-like states are robust against the collective dephasing, and some kinds of Werner-like states is fragile and becomes completely disentangled in a finite-time. The threshold time of complete disentanglement of the fragile Werner-like states is given. The influence of external driving field on the finite-time disentanglement of the standard Werner state or Werner-like states is discussed. Furthermore, we present a simple method to control the stationary state entanglement and Bell violation of two qubits. Finally, we show that the theoretical calculations of fidelity based on the initial Werner state assumption well agree with previous experimental results.Comment: 7 pages, 6 figures, 1 table, RevTex4, Accepted by EPJ

War, industrial mobilisation and society in Northern Ireland, 1939-1945

Archive-based regional studies can contribute much that is new to the economic, political and social history of the Second World War. This paper considers the process of industrial mobilisation in Northern Ireland, a politically divided region which was part of the United Kingdom but which had its own government. It examines the changing administrative framework of war production, the debate on military and industrial conscription, the role of women and the economic implications of geographical remoteness from London. The paper adds to our limited knowledge of regional mobilisation and contributes to a neglected aspect of the history of Northern Ireland. © 2007 Cambridge University Press

Burden Reduction: An Evaluation of Statutory Instruments in the UK Government's Regulatory Off-setting and Business Impact Target Initiatives 2010-2019

© The Author(s) 2023. Published by Oxford University Press on behalf of the Hansard Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https:// creativecommons.org/licenses/by/4.0/).This article analyses Statutory Instruments passed between 2010 and 2019 to evaluate the embeddedness of the UK Government’s regulatory off-setting and Business Impact Target initiatives. It begins by outlining the origins of those initiatives and their scope, technical details and compliance mechanisms. After describing the methodology for the analysis, it reports results showing that a range of exclusions and exemptions limit the number of Statutory Instruments covered by the initiatives, that the intensity with which burden reduction is pursued declines over time and that the largest savings are incidental rather than being motivated by a desire to reduce burden.Peer reviewe

A STUDY OF THE MOLECULAR GENETICS OF RENAL CELL CARCINOMA IN MAN

The aim was to measure the expression levels of hypoxia inducible factor 1-α (HJF-lα), glucose transporter one (GLUT-1), and vascular endothelial growth factor (VEGF) isoforms 165 and 189 mRNA in patients with renal cell carcinoma (RCC). Patients with RCC underwent radical nephrectomy at Derriford Hospital, Plymouth. Tumour as well as matched normal tissue from the kidney was harvested, snap frozen and stored in liquid nitrogen, and used to quantitate VEGF 165, VEGF 189, GLUT-1 and HJF-1α mRNA expression using ribonuclease protection assays, and quantified using a Phosphor-imager system. The VEGF 165 isoform was increased in the tumour tissue in comparison with the adjacent normal tissue (3.05 vs. 1.56 P=0.00002) as was the VEGF 189 isoform (2.41 vs. 1.43 P=0.0002). Forty four patients were analysed for the expression of HIF-lα and GLUT-1 with statically significant differences seen between the tumour tissues with respect to the normal tissue for both HIF-lα (1.34 vs. 1.10 P=0.01) and GLUT-1 (1.99 vs. 1.63 P=0.003). Hypoxia inducible factor I (HIF-1) is a key regulator of genes involved in the hypoxic response. HIF consists of alpha and beta subunits, with the alpha subunit being degraded under normoxic conditions and stabilised under hypoxia. Polymorph isms in exon 12 of the HIF gene have been recently been identified consisting of nucleotide changes (C+ 1772T and G+ 1790A) resulting in an amino acid substitution from Proline 582 to Serine, and Alanine 588 to Threonine respectively. These polymorphisms are found within the oxygen-dependent degradation domain (ODD) of the HIF-lα protein when transcribed which is important in the oxygen regulation of the protein via hydroxylation of the proline residue at position 564 (P564) by HIF-α- prolylhydroxylase (HIF-PH). The regulation of HIF-1α by this method is a novel way of regulating the levels of the protein, and polymorphisms in the ODD of HIF-lα may affect the ability of VHL to direct the alpha subunit for destruction. We have genotyped 146 patients and 288 controls for the G+ 1790A, and 160 patients and 162 controls for the C+ 1772T polymorphisms respectively. We found an increase in both the GA and CC (P<0.00001 and P= 0.00002) genotypes in our patients with renal cell carcinoma, and a decrease in GG and CT (P<0.00001 and P=0.00002) genotypes respectively. Haplotype analysis revealed there to be an increase in the T-A and C-A haplotypes (P=0.00008, and P=0.02) and a decrease in the T-G haplotype P=0.01. No statistical difference was found for the other haplotypes. We have shown that these HIF-lα polymorphisms are present in RCC with increased frequency and may play an important role in the disease process, leading to increased angiogenesis in the tumour. Vascular endothelial growth factor (VEGF) is a highly specific mitogen that is able to stimulate the proliferation of endothelial cells. There have been a number of findings linking the expression of VEGF with RCC, with it also being used to assess the prognosis of the disease. Polymorphisms in the VEGF gene have been recently identified. A possible link between promoter polymorphisms and expression of mRNA isoforms has been found in a variety of cytokines. Certain polymorphisms in renal cell carcinoma patients can lead to an up regulation of the expression of the mRNA, and may be a factor in the highly vascularized nature of the tumours studied. The aim was to investigate the frequency of polymorphisms within the VEGF gene (C-2578A) in 173 patients with RCC and 142 normal controls. No differences were seen between the patients and control populations, and the polymorphism did not correlate with Robson stage, Fuhrman grade or age and gender. Although a trend was seen between the C- 2578A polymorphism and expression of VEGF mRNA species in RCC patients

The relationship between business incubator services and the psychological capital of tenants

Business incubators (BI) provide a supportive environment for new tenant businesses to grow to independence. Incubators offer characteristic services including (a) space, physical resources, and infrastructure; (b) business support services, (c) networking; and, (d) structured selection, entry, and exit. Despite the global growth in incubator facilities, complemented by extensive research, knowledge gaps remain. Little research has examined the relationship between the characteristic services at incubators and tenants’ psychological capital; a higher-order construct representing an individual’s positive psychological state of development that includes hope, efficacy, resilience, and optimism. Preliminary examination of the characteristic services at business incubators show analogies with interventions for developing psychological capital. Two research studies were designed to examine these relationships. In the first study, survey (n = 30) and interview data (n = 12) were collected from incubator tenants to examine the existence of a relationship between the four characteristic services at business incubators and tenants’ psychological capital, their hope, efficacy, resilience, and optimism. The survey data confirmed the existence of a relationship between three incubator services – space, physical resources, and infrastructure, business support services, and networking – and tenants’ psychological capital. Tenants’ narrative experiences confirmed that these same three incubator services support tenants’ hope, efficacy, resilience, and optimism. This finding implies that the three incubator services contribute to, and augment tenants’ positive psychological states, which is then manifest in their positive behaviours and attitudes towards their business. To further elucidate these relationships a second study was conducted. Data from surveys (n = 75) and interviews (n = 28) with incubators managers also confirmed that space, physical resources, and infrastructure, business support services, and networking were analogous with methods that support tenants’ hope, efficacy, resilience, and optimism. These findings infer that incubator managers are not only instrumental in delivering these three characteristic services at incubators but are integral in optimising these services to benefit tenants’ hope, efficacy, resilience, and optimism. This current research provides robust evidence that three characteristic services at incubators are associated with tenants’ psychological capital, hope, efficacy, resilience, and optimism. These research findings are novel, and the implications for the incubator industry wide-ranging, with evidence indicating that the three characteristic services at incubators are analogous with interventions that support tenants’ psychological capital, and that incubator staff are integral to the delivery of these characteristic services. New directions for the incubator industry are proposed that include establishing a consistent approach to delivering the characteristic services at incubators that support incubator tenants’ businesses, and their positive psychological development.Doctor of Philosoph

Presynaptic adenosine receptor-mediated regulation of diverse thalamocortical short-term plasticity in the mouse whisker pathway

Short-term synaptic plasticity (STP) sets the sensitivity of a synapse to incoming activity and determines the temporal patterns that it best transmits. In “driver” thalamocortical (TC) synaptic populations, STP is dominated by depression during stimulation from rest. However, during ongoing stimulation, lemniscal TC connections onto layer 4 neurons in mouse barrel cortex express variable STP. Each synapse responds to input trains with a distinct pattern of depression or facilitation around its mean steady-state response. As a result, in common with other synaptic populations, lemniscal TC synapses express diverse rather than uniform dynamics, allowing for a rich representation of temporally varying stimuli. Here, we show that this STP diversity is regulated presynaptically. Presynaptic adenosine receptors of the A1R type, but not kainate receptors (KARs), modulate STP behavior. Blocking the receptors does not eliminate diversity, indicating that diversity is related to heterogeneous expression of multiple mechanisms in the pathway from presynaptic calcium influx to neurotransmitter release