Electron Spin Decoherence in Bulk and Quantum Well Zincblende Semiconductors

A theory for longitudinal (T1) and transverse (T2) electron spin coherence times in zincblende semiconductor quantum wells is developed based on a non-perturbative nanostructure model solved in a fourteen-band restricted basis set. Distinctly different dependences of coherence times on mobility, quantization energy, and temperature are found from previous calculations. Quantitative agreement between our calculations and measurements is found for GaAs/AlGaAs, InGaAs/InP, and GaSb/AlSb quantum wells.Comment: 11 pages, 3 figure

Policy, Performativity and Partnership: an Ethical Leadership Perspective

This article identifies the need to think differently about educational partnerships in a changing and turbulent post compulsory policy environment in England. The policy and institutional contexts in which universities and colleges currently operate seem to be fuelling performativity at the expense of educational values. There appears to be a sharp interruption in the steady increase in educational partnerships as a vehicle for increasing and widening participation in higher education. We are witnessing a marked change in university / college relationships that appears to be a consequence of government calling a halt to increased participation in higher education, creating an increasingly competitive market for a more limited pool of student places. The implication that educational policy at the national level determines a particular pattern or mode of leadership decision making throughout an institution should however be resisted. Policy developments that challenge the moral precepts of education should not be allowed to determine how a leader acts, rather they should prompt actions that are truly educational, rooted in morality, and atached to identifiable educational values. Educational leaders have agency to resist restricted discourses in favour of ethical and principled change strategies that are a precondition for sustainable transformative partnerships in post compulsory education. University leaders in particular are called upon to use their considerable influence to resist narrow policy or managerial instrumentalism or performativity and embrace alternatives that are both educationally worthwhile and can enhance institutional resilience

Radiation-induced oscillatory magnetoresistance as a sensitive probe of the zero-field spin splitting in high mobility GaAs/AlGaAs devices

We suggest an approach for characterizing the zero-field spin splitting of high mobility two-dimensional electron systems, when beats are not readily observable in the Shubnikov-de Haas effect. The zero-field spin splitting and the effective magnetic field seen in the reference frame of the electron is evaluated from a quantitative study of beats observed in radiation-induced magnetoresistance oscillations.Comment: 4 pages, 4 color figure

Anisotropic splitting of intersubband spin plasmons in quantum wells with bulk and structural inversion asymmetry

In semiconductor heterostructures, bulk and structural inversion asymmetry and spin-orbit coupling induce a k-dependent spin splitting of valence and conduction subbands, which can be viewed as being caused by momentum-dependent crystal magnetic fields. This paper studies the influence of these effective magnetic fields on the intersubband spin dynamics in an asymmetric n-type GaAs/AlGaAs quantum well. We calculate the dispersions of intersubband spin plasmons using linear response theory. The so-called D'yakonov-Perel' decoherence mechanism is inactive for collective intersubband excitations, i.e., crystal magnetic fields do not lead to decoherence of spin plasmons. Instead, we predict that the main signature of bulk and structural inversion asymmetry in intersubband spin dynamics is a three-fold, anisotropic splitting of the spin plasmon dispersion. The importance of many-body effects is pointed out, and conditions for experimental observation with inelastic light scattering are discussed.Comment: 8 pages, 6 figure

Board gender diversity and firm performance: the UK evidence

The file attached to this record is the author's final peer reviewed version.open access articleThis paper examines the relationship between gender diversity, selected female attributes and financial performance of FTSE 100 firms in the UK. Drawing on critical mass theory by measuring gender diversity as levels of female representation in the boardroom, this study finds a positive and significant relationship between gender diversity and firm performance. However, the results become highly significant and unequivocal when three or more females are appointed to the board compared to the appointment of two or less females. Further analysis reveals that post-appointment financial performance is positively related to female age, level of education and where female board members also hold executive director positions. The results remain unchanged after accounting for endogeneity concerns and employing alternative measures of firm performance, namely, return on assets and Tobin’s Q

Understanding employee resourcing in construction organizations

In recent years the literature on employee resourcing has consistently advocated the importance of adopting a holistic, strategic approach to employee deployment decision making rather than adopting a reactive needs-based approach. This is particularly problematic in construction where the multi-project environment leads to constantly changing resource requirements and to changing demands over a project's life cycle. This can lead to inappropriate decisions, which fail to meet the longer-term needs of both construction organizations and their employees. A structured and comprehensive understanding of the current project team deployment practices within large construction organizations was developed. Project deployment practices were examined within seven case study contracting firms. The emergent themes that shaped the decision-making processes were grouped into five broad clusters comprising human resource planning, performance/career management, team deployment, employee involvement and training and development. The research confirms that a reactive and ad hoc approach to the function prevails within the firms investigated. This suggests a weak relationship between the deployment process and human resource planning, team deployment, performance management, employee involvement and training and development activities. It is suggested that strategic HR-business partnering could engender more transparent and productive relationships in this crucial area

Identification of autoantigens and their potential post-translational modification in EGPA and severe eosinophilic asthma.

BACKGROUND: The chronic airway inflammation in severe eosinophilic asthma (SEA) suggests potential autoimmune aetiology with unidentified autoantibodies analogous to myeloperoxidase (MPO) in ANCA-positive EGPA (eosinophilic granulomatosis with polyangiitis). Previous research has shown that oxidative post-translational modification (oxPTM) of proteins is an important mechanism by which autoantibody responses may escape immune tolerance. Autoantibodies to oxPTM autoantigens in SEA have not previously been studied. METHODS: Patients with EGPA and SEA were recruited as well as healthy control participants. Autoantigen agnostic approach: Participant serum was incubated with slides of unstimulated and PMA-stimulated neutrophils and eosinophils, and autoantibodies to granulocytes were identified by immunofluorescence with anti-human IgG FITC antibody. Target autoantigen approach: Candidate proteins were identified from previous literature and FANTOM5 gene set analysis for eosinophil expressed proteins. Serum IgG autoantibodies to these proteins, in native and oxPTM form, were detected by indirect ELISA. RESULTS: Immunofluorescence studies showed that serum from patients with known ANCA stained for IgG against neutrophils as expected. In addition, serum from 9 of 17 tested SEA patients stained for IgG to PMA-stimulated neutrophils undergoing NETosis. Immunofluorescent staining of eosinophil slides was evident with serum from all participants (healthy and with eosinophilic disease) with diffuse cytoplasmic staining except for one SEA individual in whom subtle nuclear staining was evident. FANTOM5 gene set analysis identified TREM1 (triggering receptor expressed on myeloid cells 1) and IL-1 receptor 2 (IL1R2) as eosinophil-specific targets to test for autoantibody responses in addition to MPO, eosinophil peroxidase (EPX), and Collagen-V identified from previous literature. Indirect ELISAs found high concentrations of serum autoantibodies to Collagen-V, MPO, and TREM1 in a higher proportion of SEA patients than healthy controls. High concentrations of serum autoantibodies to EPX were evident in serum from both healthy and SEA participants. The proportion of patients with positive autoantibody ELISAs was not increased when examining oxPTM compared to native proteins. DISCUSSION: Although none of the target proteins studied showed high sensitivity for SEA, the high proportion of patients positive for at least one serum autoantibody shows the potential of more research on autoantibody serology to improve diagnostic testing for severe asthma. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, identifier, NCT04671446

Spin-orbit terms in multi-subband electron systems: A bridge between bulk and two-dimensional Hamiltonians

We analyze the spin-orbit terms in multi-subband quasi-two-dimensional electron systems, and how they descend from the bulk Hamiltonian of the conduction band. Measurements of spin-orbit terms in one subband alone are shown to give incomplete information on the spin-orbit Hamiltonian of the system. They should be complemented by measurements of inter-subband spin-orbit matrix elements. Tuning electron energy levels with a quantizing magnetic field is proposed as an experimental approach to this problem.Comment: Typos noticed in the published version have been corrected and several references added. Published in the special issue of Semiconductors in memory of V.I. Pere

The Paradox of Power in CSR: A Case Study on Implementation

Purpose Although current literature assumes positive outcomes for stakeholders resulting from an increase in power associated with CSR, this research suggests that this increase can lead to conflict within organizations, resulting in almost complete inactivity on CSR. Methods A single in-depth case study, focusing on power as an embedded concept. Results Empirical evidence is used to demonstrate how some actors use CSR to improve their own positions within an organization. Resource dependence theory is used to highlight why this may be a more significant concern for CSR. Conclusions Increasing power for CSR has the potential to offer actors associated with it increased personal power, and thus can attract opportunistic actors with little interest in realizing the benefits of CSR for the company and its stakeholders. Thus power can be an impediment to furthering CSR strategy and activities at the individual and organizational level

Signaling in Secret: Pay-for-Performance and the Incentive and Sorting Effects of Pay Secrecy

Key Findings: Pay secrecy adversely impacts individual task performance because it weakens the perception that an increase in performance will be accompanied by increase in pay; Pay secrecy is associated with a decrease in employee performance and retention in pay-for-performance systems, which measure performance using relative (i.e., peer-ranked) criteria rather than an absolute scale (see Figure 2 on page 5); High performing employees tend to be most sensitive to negative pay-for- performance perceptions; There are many signals embedded within HR policies and practices, which can influence employees’ perception of workplace uncertainty/inequity and impact their performance and turnover intentions; and When pay transparency is impractical, organizations may benefit from introducing partial pay openness to mitigate these effects on employee performance and retention