1,135 research outputs found
Conscience as the Organising Concept in Equity
ArticleThis article sets out a defence of the concept of equity based on conscience by tracing its development from the earliest cases, by establishing that a conscience is something objective and not subjective, and by demonstrating that the idea of conscience provides a coherent central principle for equitable doctrines. Equity is based on a methodology identified by Aristotle in his Ethics which seeks to mitigate the rigour of abstract rules, and also on the idea of conscience. Contrary to most of the assumptions made in the academic commentary on equity, a conscience is an objectively constituted phenomenon. This understanding of a conscience is a commonplace across our culture in sources as disparate as the work of Freud and Kant, in Shakespeare’s King Lear, and in Walt Disney’s Pinocchio. The conscience is the internal policeman which is planted in our minds by our interactions with the outside world. Consequently, when a court judges in the name of conscience, that court is holding up the individual’s behaviour to an objective standard. This conceptualisation of conscience and of “unconscionability” is shown to be the common thread running through the law on dishonest assistance, secret trusts, bribery, proprietary estoppel, ownership of the home and so on. The centuries-old arguments about the efficacy of equity turn on this understanding of a conscience and they can be resolved by reference to it
Thermal-Error Regime in High-Accuracy Gigahertz Single-Electron Pumping
Single-electron pumps based on semiconductor quantum dots are promising candidates for the emerging quantum standard of electrical current. They can transfer discrete charges with part-per-million (ppm) precision in nanosecond time scales. Here, we employ a metal-oxide-semiconductor silicon quantum dot to experimentally demonstrate high-accuracy gigahertz single-electron pumping in the regime where the number of electrons trapped in the dot is determined by the thermal distribution in the reservoir leads. In a measurement with traceability to primary voltage and resistance standards, the averaged pump current over the quantized plateau, driven by a 1-GHz sinusoidal wave in the absence of a magnetic field, is equal to the ideal value of ef within a measurement uncertainty as low as 0.27 ppm
Cost-effectiveness of a community-delivered multicomponent intervention compared with enhanced standard care of obese adolescents: cost-utility analysis alongside a randomised controlled trial (the HELP trial)
OBJECTIVE: To undertake a cost-utility analysis of a motivational multicomponent lifestyle-modification intervention in a community setting (the Healthy Eating Lifestyle Programme (HELP)) compared with enhanced standard care. DESIGN: Cost-utility analysis alongside a randomised controlled trial. SETTING: Community settings in Greater London, England. PARTICIPANTS: 174 young people with obesity aged 12-19 years. INTERVENTIONS: Intervention participants received 12 one-to-one sessions across 6 months, addressing lifestyle behaviours and focusing on motivation to change and self-esteem rather than weight change, delivered by trained graduate health workers in community settings. Control participants received a single 1-hour one-to-one nurse-delivered session providing didactic weight-management advice. MAIN OUTCOME MEASURES: Mean costs and quality-adjusted life years (QALYs) per participant over a 1-year period using resource use data and utility values collected during the trial. Incremental cost-effectiveness ratio (ICER) was calculated and non-parametric bootstrapping was conducted to generate a cost-effectiveness acceptability curve (CEAC). RESULTS: Mean intervention costs per participant were £918 for HELP and £68 for enhanced standard care. There were no significant differences between the two groups in mean resource use per participant for any type of healthcare contact. Adjusted costs were significantly higher in the intervention group (mean incremental costs for HELP vs enhanced standard care £1003 (95% CI £837 to £1168)). There were no differences in adjusted QALYs between groups (mean QALYs gained 0.008 (95% CI -0.031 to 0.046)). The ICER of the HELP versus enhanced standard care was £120 630 per QALY gained. The CEAC shows that the probability that HELP was cost-effective relative to the enhanced standard care was 0.002 or 0.046, at a threshold of £20 000 or £30 000 per QALY gained. CONCLUSIONS: We did not find evidence that HELP was more effective than a single educational session in improving quality of life in a sample of adolescents with obesity. HELP was associated with higher costs, mainly due to the extra costs of delivering the intervention and therefore is not cost-effective. TRIAL REGISTRATION NUMBER: ISRCTN9984011
Coherent electrical control of a single high-spin nucleus in silicon
Nuclear spins are highly coherent quantum objects. In large ensembles, their control and detection via magnetic resonance is widely exploited, for example, in chemistry, medicine, materials science and mining. Nuclear spins also featured in early proposals for solid-state quantum computers1 and demonstrations of quantum search2 and factoring3 algorithms. Scaling up such concepts requires controlling individual nuclei, which can be detected when coupled to an electron4–6. However, the need to address the nuclei via oscillating magnetic fields complicates their integration in multi-spin nanoscale devices, because the field cannot be localized or screened. Control via electric fields would resolve this problem, but previous methods7–9 relied on transducing electric signals into magnetic fields via the electron–nuclear hyperfine interaction, which severely affects nuclear coherence. Here we demonstrate the coherent quantum control of a single 123Sb (spin-7/2) nucleus using localized electric fields produced within a silicon nanoelectronic device. The method exploits an idea proposed in 196110 but not previously realized experimentally with a single nucleus. Our results are quantitatively supported by a microscopic theoretical model that reveals how the purely electrical modulation of the nuclear electric quadrupole interaction results in coherent nuclear spin transitions that are uniquely addressable owing to lattice strain. The spin dephasing time, 0.1 seconds, is orders of magnitude longer than those obtained by methods that require a coupled electron spin to achieve electrical driving. These results show that high-spin quadrupolar nuclei could be deployed as chaotic models, strain sensors and hybrid spin-mechanical quantum systems using all-electrical controls. Integrating electrically controllable nuclei with quantum dots11,12 could pave the way to scalable, nuclear- and electron-spin-based quantum computers in silicon that operate without the need for oscillating magnetic fields
Recombination rate and selection strength in HIV intra-patient evolution
The evolutionary dynamics of HIV during the chronic phase of infection is
driven by the host immune response and by selective pressures exerted through
drug treatment. To understand and model the evolution of HIV quantitatively,
the parameters governing genetic diversification and the strength of selection
need to be known. While mutation rates can be measured in single replication
cycles, the relevant effective recombination rate depends on the probability of
coinfection of a cell with more than one virus and can only be inferred from
population data. However, most population genetic estimators for recombination
rates assume absence of selection and are hence of limited applicability to
HIV, since positive and purifying selection are important in HIV evolution.
Here, we estimate the rate of recombination and the distribution of selection
coefficients from time-resolved sequence data tracking the evolution of HIV
within single patients. By examining temporal changes in the genetic
composition of the population, we estimate the effective recombination to be
r=1.4e-5 recombinations per site and generation. Furthermore, we provide
evidence that selection coefficients of at least 15% of the observed
non-synonymous polymorphisms exceed 0.8% per generation. These results provide
a basis for a more detailed understanding of the evolution of HIV. A
particularly interesting case is evolution in response to drug treatment, where
recombination can facilitate the rapid acquisition of multiple resistance
mutations. With the methods developed here, more precise and more detailed
studies will be possible, as soon as data with higher time resolution and
greater sample sizes is available.Comment: to appear in PLoS Computational Biolog
'Digital by Default' and the 'hard to reach': Exploring solutions to digital exclusion in remote rural areas
Williams, F., Philip, L., Fairhurst, G., & Farrington, J. (2016). ‘Digital by Default’ and ‘the hard to reach’: exploring solutions to digital exclusion in remote rural areas. Local Economy, 31(7), 757-777. DOI: 10.1177/0269094216670938. Copyright © 2016 SAGE. Reprinted by permission of SAGE Publications.In the UK, the geography of Information and Communication Technology (ICT) infrastructure required for Internet connectivity is such that high speed broadband and mobile phone networks are generally less available in rural areas compared with urban areas or, in other words, as remoteness and population sparsity increase so too does the likelihood of an area having no or very poor broadband connectivity. Against a policy backdrop of UK Government efforts to bring forward network infrastructure upgrades and to improve the accessibility of broadband services in locations where there is a weak commercial investment case, this paper considers the options for the ‘final few’ in the prevailing ‘Digital by Default’ public services context. The paper outlines the Rural Public Access WiFi Services project, a study focused upon enabling Internet connectivity for commercially ‘hard to reach’ rural areas in the UK. The Rural Public Access WiFi Services concept and the experiment are introduced before findings from a pilot deployment of a broadband service to households in a remote rural area, who may be classified as ‘digitally excluded’, are presented. The paper then reflects on our field experiment and the potential of the Rural Public Access WiFi Services model as a solution to overcoming some of the digital participation barriers manifest in the urban–rural divide. Early indications show that the Rural Public Access WiFi Services model has the potential to encourage participation in the Digital Economy and could aid the UK Government’s Digital by Default agenda, although adoption of the model is not without its challenges
WNT signaling regulates self-renewal and differentiation of prostate cancer cells with stem cell characteristics
Prostate cancer cells with stem cell characteristics were identified in human prostate cancer cell lines by their ability to form from single cells self-renewing prostaspheres in non-adherent cultures. Prostaspheres exhibited heterogeneous expression of proliferation, differentiation and stem cell-associated makers CD44, ABCG2 and CD133. Treatment with WNT inhibitors reduced both prostasphere size and self-renewal. In contrast, addition of Wnt3a caused increased prostasphere size and self-renewal, which was associated with a significant increase in nuclear Β-catenin, keratin 18, CD133 and CD44 expression. As a high proportion of LNCaP and C4-2B cancer cells express androgen receptor we determined the effect of the androgen receptor antagonist bicalutamide. Androgen receptor inhibition reduced prostasphere size and expression of PSA, but did not inhibit prostasphere formation. These effects are consistent with the androgen-independent self-renewal of cells with stem cell characteristics and the androgen-dependent proliferation of transit amplifying cells. As the canonical WNT signaling effector Β-catenin can also associate with the androgen receptor, we propose a model for tumour propagation involving a balance between WNT and androgen receptor activity. That would affect the self-renewal of a cancer cell with stem cell characteristics and drive transit amplifying cell proliferation and differentiation. In conclusion, we provide evidence that WNT activity regulates the self-renewal of prostate cancer cells with stem cell characteristics independently of androgen receptor activity. Inhibition of WNT signaling therefore has the potential to reduce the self-renewal of prostate cancer cells with stem cell characteristics and improve the therapeutic outcome.Peer reviewe
Analytical Framework for Identifying and Differentiating Recent Hitchhiking and Severe Bottleneck Effects from Multi-Locus DNA Sequence Data
Hitchhiking and severe bottleneck effects have impact on the dynamics of genetic diversity of a population by inducing homogenization at a single locus and at the genome-wide scale, respectively. As a result, identification and differentiation of the signatures of such events from DNA sequence data at a single locus is challenging. This paper develops an analytical framework for identifying and differentiating recent homogenization events at multiple neutral loci in low recombination regions. The dynamics of genetic diversity at a locus after a recent homogenization event is modeled according to the infinite-sites mutation model and the Wright-Fisher model of reproduction with constant population size. In this setting, I derive analytical expressions for the distribution, mean, and variance of the number of polymorphic sites in a random sample of DNA sequences from a locus affected by a recent homogenization event. Based on this framework, three likelihood-ratio based tests are presented for identifying and differentiating recent homogenization events at multiple loci. Lastly, I apply the framework to two data sets. First, I consider human DNA sequences from four non-coding loci on different chromosomes for inferring evolutionary history of modern human populations. The results suggest, in particular, that recent homogenization events at the loci are identifiable when the effective human population size is 50000 or greater in contrast to 10000, and the estimates of the recent homogenization events are agree with the “Out of Africa” hypothesis. Second, I use HIV DNA sequences from HIV-1-infected patients to infer the times of HIV seroconversions. The estimates are contrasted with other estimates derived as the mid-time point between the last HIV-negative and first HIV-positive screening tests. The results show that significant discrepancies can exist between the estimates
Clinical and molecular features of an infant patient affected by Leigh Disease associated to m.14459G > A mitochondrial DNA mutation: a case report
<p>Abstract</p> <p>Background</p> <p>Leigh Syndrome (LS) is a severe neurodegenerative disorder characterized by bilateral symmetrical necrotic lesions in the basal ganglia and brainstem. Onset is in early infancy and prognosis is poor. Causative mutations have been disclosed in mitochondrial DNA and nuclear genes affecting respiratory chain subunits and assembly factors.</p> <p>Case presentation</p> <p>Here we report the clinical and molecular features of a 15-month-old female LS patient. Direct sequencing of her muscle-derived mtDNA revealed the presence of two apparently homoplasmic variants: the novel m.14792C > G and the already known m.14459G > A resulting in p.His16Asp change in cytochrome b (MT-CYB) and p.Ala72Val substitution in ND6 subunit, respectively. The m.14459G > A was heteroplasmic in the mother's blood-derived DNA.</p> <p>Conclusions</p> <p>The m.14459G > A might lead to LS, complicated LS or Leber Optic Hereditary Neuropathy. A comprehensive re-evaluation of previously described 14459G > A-mutated patients does not explain this large clinical heterogeneity.</p
Compensation for Changing Motor Uncertainty
When movement outcome differs consistently from the intended movement, errors are used to correct subsequent movements (e.g., adaptation to displacing prisms or force fields) by updating an internal model of motor and/or sensory systems. Here, we examine changes to an internal model of the motor system under changes in the variance structure of movement errors lacking an overall bias. We introduced a horizontal visuomotor perturbation to change the statistical distribution of movement errors anisotropically, while monetary gains/losses were awarded based on movement outcomes. We derive predictions for simulated movement planners, each differing in its internal model of the motor system. We find that humans optimally respond to the overall change in error magnitude, but ignore the anisotropy of the error distribution. Through comparison with simulated movement planners, we found that aimpoints corresponded quantitatively to an ideal movement planner that updates a strictly isotropic (circular) internal model of the error distribution. Aimpoints were planned in a manner that ignored the direction-dependence of error magnitudes, despite the continuous availability of unambiguous information regarding the anisotropic distribution of actual motor errors
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