Duality and the Legendre Transform

We define a weak-strong coupling transformation based on the Legendre transformation of the effective action. In the case of N\es 2 supersymmetric Yang-Mills theory, this coincides with the duality transform on the low energy effective action considered by Seiberg and Witten. This Legendre transform interpretation of duality generalizes directly to the full effective action, and in principle to other theories.Comment: 6 pages, LaTe

In vivo screening reveals interactions between Drosophila Manf and genes involved in the mitochondria and the ubiquinone synthesis pathway

Background: Mesencephalic Astrocyte-derived Neurotrophic Factor (MANF) and Cerebral Dopamine Neurotrophic Factor (CDNF) form an evolutionarily conserved family of neurotrophic factors. Orthologues for MANF/CDNF are the only neurotrophic factors as yet identified in invertebrates with conserved amino acid sequence. Previous studies indicate that mammalian MANF and CDNF support and protect brain dopaminergic system in non-cell-autonomous manner. However, MANF has also been shown to function intracellularly in the endoplasmic reticulum. To date, the knowledge on the interacting partners of MANF/CDNF and signaling pathways they activate is rudimentary. Here, we have employed the Drosophila genetics to screen for potential interaction partners of Drosophila Manf (DmManf) in vivo. Results: We first show that DmManf plays a role in the development of Drosophila wing. We exploited this function by using Drosophila UAS-RNAi lines and discovered novel genetic interactions of DmManf with genes known to function in the mitochondria. We also found evidence of an interaction between DmManf and the Drosophila homologue encoding Ku70, the closest structural homologue of SAP domain of mammalian MANF. Conclusions: In addition to the previously known functions of MANF/CDNF protein family, DmManf also interacts with mitochondria-related genes. Our data supports the functional importance of these evolutionarily significant proteins and provides new insights for the future studies.Peer reviewe

The person-centred approach to an ageing society

Modern care is often based on investigations such as laboratory markers and imaging - for example, X-ray or ultrasound. The results contribute to a diagnosis and, if judged necessary, treatment is initiated. This diseased-oriented approach is the prevailing mode of management in modern medicine. In contrast, person-centered care (PCC) takes the point of departure from each person\ub4s subjective experience of illness and its impact on daily life. A patient is considered as a person with emotions and feelings. PCC is considered present within clinical care according to a definition articulated by the Centre for Person Centred Care at the University of Gothenburg (GPCC) when three core components are present: elicitation of a detailed patient narrative; formulated partnership between caregiver and patient and documentation of the partnership in the patient record. Accordingly, when there is an illness requiring care and the person is attended using these components, PCC is being applied. In most situations today, PCC is not applied in terms of the narrative and is not fully elicited or the partnership and/or the documentation are not included. It is proposed that the challenge to Society arising from changing demographics can be addressed by implementing PCC and creating an alternative to existing healthcare. The importance and benefits of such an approach on a wider scale is not yet clear as research has been limited to date. Studies in selected patient populations (heart failure and hip fractures), however, have shown promising results. As the population ages, there will be a dramatic increase in healthcare consumption. Even with technological developments, there will be a need for tremendous resources to be dedicated to care. A new organization and attitude from healthcare policymakers and providers above and beyond the present model appears required in order to respond to this demand. As part of such change, person-centred care, with the interaction between healthcare providers and the person of the patient, can facilitate, compensate and develop more effective healthcare services for the future

Worldsheet Instantons and a Null String Limit of Born-Infeld Theory

For a superstring theory in four spacetime dimensions, we propose a modification of the Born-Infeld action that possesses a well-defined tensionless limit. We interpret this as describing the effective target space dynamics of null strings on a D3-brane. We argue that such a modification can be induced by nonperturbative contributions from instantons in the worldsheet sigma-model describing string propagation on the brane.Comment: 11 pages; Comments and references adde

Twistor theory of hyper-K{\"a}hler metrics with hidden symmetries

We briefly review the hierarchy for the hyper-K\"ahler equations and define a notion of symmetry for solutions of this hierarchy. A four-dimensional hyper-K\"ahler metric admits a hidden symmetry if it embeds into a hierarchy with a symmetry. It is shown that a hyper-K\"ahler metric admits a hidden symmetry if it admits a certain Killing spinor. We show that if the hidden symmetry is tri-holomorphic, then this is equivalent to requiring symmetry along a higher time and the hidden symmetry determines a `twistor group' action as introduced by Bielawski \cite{B00}. This leads to a construction for the solution to the hierarchy in terms of linear equations and variants of the generalised Legendre transform for the hyper-K\"ahler metric itself given by Ivanov & Rocek \cite{IR96}. We show that the ALE spaces are examples of hyper-K\"ahler metrics admitting three tri-holomorphic Killing spinors. These metrics are in this sense analogous to the 'finite gap' solutions in soliton theory. Finally we extend the concept of a hierarchy from that of \cite{DM00} for the four-dimensional hyper-K\"ahler equations to a generalisation of the conformal anti-self-duality equations and briefly discuss hidden symmetries for these equations.Comment: Final version. To appear in the August 2003 special issue of JMP on `Integrability, Topological Solitons, and Beyond

Angle-Dependent Microresonator ESR Characterization of Locally Doped Gd3+:Al2O3

Interfacing rare-earth-doped crystals with superconducting circuit architectures provides an attractive platform for quantum memory and transducer devices. Here, we present the detailed characterization of such a hybrid system: a locally implanted rare-earth Gd3+ in Al2O3 spin system coupled to a superconducting microresonator. We investigate the properties of the implanted spin system through angular-dependent microresonator electron spin resonance (micro-ESR) spectroscopy. We find, despite the high-energy near-surface implantation, the resulting micro-ESR spectra to be in excellent agreement with the modeled Hamiltonian, supporting the integration of dopant ions into their relevant lattice sites while maintaining crystalline symmetries. Furthermore, we observe clear contributions from individual microwave field components of our microresonator, emphasizing the need for controllable local implantation

Goldstino and sgoldstino in microscopic models and the constrained superfields formalism

We examine the exact relation between the superconformal symmetry breaking chiral superfield (X) and the goldstino superfield in microscopic models of an arbitrary Kahler potential (K) and in the presence of matter fields. We investigate the decoupling of the massive sgoldstino and scalar matter fields and the offshell/onshell-SUSY expressions of their superfields in terms of the fermions composites. For general K of two superfields, we study the properties of the superfield X after integrating out these scalar fields, to show that in the infrared it satisfies (offshell) the condition $X^3=0$ and $X^2\not=0$. We then compare our results to those of the well-known method of constrained superfields discussed in the literature, based on the conjecture $X^2=0$. Our results can be used in applications, to couple offshell the (s)goldstino fields to realistic models such as the MSSM.Comment: 24 page