Quantum and classical localisation and the Manhattan lattice

We consider a network model, embedded on the Manhattan lattice, of a quantum localisation problem belonging to symmetry class C. This arises in the context of quasiparticle dynamics in disordered spin-singlet superconductors which are invariant under spin rotations but not under time reversal. A mapping exists between problems belonging to this symmetry class and certain classical random walks which are self-avoiding and have attractive interactions; we exploit this equivalence, using a study of the classical random walks to gain information about the corresponding quantum problem. In a field-theoretic approach, we show that the interactions may flow to one of two possible strong coupling regimes separated by a transition: however, using Monte Carlo simulations we show that the walks are in fact always compact two-dimensional objects with a well-defined one-dimensional surface, indicating that the corresponding quantum system is localised.Comment: 11 pages, 8 figure

Quantum and classical localisation, the spin quantum Hall effect and generalisations

We consider network models for localisation problems belonging to symmetry class C. This symmetry class arises in a description of the dynamics of quasiparticles for disordered spin-singlet superconductors which have a Bogoliubov - de Gennes Hamiltonian that is invariant under spin rotations but not under time-reversal. Our models include but also generalise the one studied previously in the context of the spin quantum Hall effect. For these systems we express the disorder-averaged conductance and density of states in terms of sums over certain classical random walks, which are self-avoiding and have attractive interactions. A transition between localised and extended phases of the quantum system maps in this way to a similar transition for the classical walks. In the case of the spin quantum Hall effect, the classical walks are the hulls of percolation clusters, and our approach provides an alternative derivation of a mapping first established by Gruzberg, Read and Ludwig, Phys. Rev. Lett. 82, 4254 (1999).Comment: 11 pages, 5 figure

Facing complexity, crisis, and risk: Opportunities and challenges in international human resource management

International human resource management (IHRM) as a field of practice involves heightened levels of complexity compared to domestic HRM based on the multitude of contexts in which multinational firms operate. As complexity increases, so do levels of risk and the chance the firm must deal with crisis situations. Based on articles presented at the 3rd Global Conference on IHRM, this special issue focuses on how IHRM can contribute to organization success when faced with extreme operating conditions. This editorial provides a backdrop to the articles by describing the challenging economic, political, and social environments impacting organizations, exploring conditions from the recent past and current day such as the global financial crisis, trends toward political nationalism, aging populations, and growing immigrant workforces. The focus lies on exploring how HRM can respond to such challenging external contexts to continue to contribute added value to the firm

Frames and actors: translating talent management strategy to Latin America

Multinational enterprises (MNEs) transfer their corporate strategies to subsidiaries globally, and in so doing, embark on a translation process. Despite the prevalence of MNEs and their investments in emerging economies, little is known about how local factors affect key actors when translating corporate talent management strategies (CTM) strategies to these regions. This study draws from the translation and talent management literatures to explore the travel of ideas in the context of CTM. Relevant frames (narratives that emerge around actions) and actors are proposed and explored empirically in a qualitative study of 76 employees across an Australian mining MNE with subsidiaries located in Latin America. The findings support extant literature as well as uncovering new frames (categorized in external or corporate, and internal or local) and actors (including non-managerial) as part of the translation process. The findings suggest the need to balance talent management strategies between corporate and subsidiaries by being aware of internal and external frames including in both urban and rural locations. This understanding provides further clarification of the global versus local paradox faced by MNEs. Implications for future research and practice are discussed

Clinical and radiological predictors of complete excision in breast-conserving surgery for primary breast cancer

BackgroundLocal recurrence after conservative surgery for breast cancer usually results from growth of residual cancer adjacent to the excised primary tumour or from multicentric disease. Complete local excision (CLE) confirmed histologically is essential to ensure that the risk of local recurrence is minimal. This study was undertaken to determine that clinical or radiological factors may assist the surgeon at the time of surgery to achieve this aim.MethodsA retrospective review of 101 cases treated by conservative surgery identified 70 cases of CLE and 31 of incomplete local excision (ILE). Clinical, surgical and histopathological data were taken from hospital records. Mammographic features and those of specimen X-rays were evaluated without knowledge of the histopathological outcome of surgery.ResultsComplete excision was significantly associated with type of operation (lumpectomy vs wide local excision/quadrantectomy, P 2.5 cm) and the presence of extensive ductal carcinoma in situ (DCIS) were associated with incomplete excision (P = 0.0005). No relationship was demonstrated with patient age, breast size, breast density, tumour grade, receptor status, axillary nodal status or spicules on X-ray and completeness of excision. Specimen X-ray had a positive predictive value of 94% with CLE.ConclusionsClinical and pre-operative mammographic parameters are important for predicting CLE for breast cancers treated by breast-conserving surgery. Specimen radiology for palpable lesions can confirm excision of the cancer and permit re-excision of breast tissue at the time of initial surgery. Its role in determining CLE should be further evaluated.Kollias, J. ; Gill, P. G. ; Beamond, B. ; Rossi, H. ; Langlois, S. ; Vernon‐roberts, E