Nonlinear interplay of Alfven instabilities and energetic particles in tokamaks

The confinement of energetic particles (EP) is crucial for an efficient heating of tokamak plasmas. Plasma instabilities such as Alfven Eigenmodes (AE) can redistribute the EP population making the plasma heating less effective, and leading to additional loads on the walls. The nonlinear dynamics of toroidicity induced AE (TAE) is investigated by means of the global gyrokinetic particle-in-cell code ORB5, within the NEMORB project. The nonperturbative nonlinear interplay of TAEs and EP due to the wave-particle nonlinearity is studied. In particular, we focus on the nonlinear modification of the frequency, growth rate and radial structure of the TAE, depending on the evolution of the EP distribution in phase space. For the ITPA benchmark case, we find that the frequency increases when the growth rate decreases, and the mode shrinks radially. This nonlinear evolution is found to be correctly reproduced by means of a quasilinear model, namely a model where the linear effects of the nonlinearly modified EP distribution function are retained.Comment: Submitted to Plasma Phys. Control. Fusio

The moral legitimacy of entrepreneurs: An analysis of early-stage entrepreneurship across 26 countries

This article develops our socio-cultural understanding of entrepreneurship by examining the influence of the moral legitimacy of entrepreneurs upon an individual’s engagement in early-stage entrepreneurship. A multilevel analysis conducted across 26 countries demonstrates that the higher the perceived degree of moral legitimacy, the more likely an individual is to consider starting a business, to begin preparing a business and to progress to actually found and run the business. We conclude that moral norms in society are an important influence upon early-stage entrepreneurship; thus, it is critical to legitimize the position of entrepreneurs as moral and beneficial for society as a whole

Field deployments of a self-contained subsea platform for acoustic monitoring of the environment around marine renewable energy structurea

The drive towards sustainable energy has seen rapid development of marine renewable energy devices, and current efforts are focusing on wave and tidal stream energy. The NERC/DEFRA collaboration FLOWBEC-4D (Flow, Water column & Benthic Ecology 4D) is addressing the lack of knowledge of the environmental and ecological effects of installing and operating large arrays of wave and tidal energy devices. The FLOWBEC sonar platform combines a number of instruments to record information at a range of physical and multi-trophic levels. Data are recorded at a resolution of several measurements per second, for durations of 2 weeks to capture an entire spring-neap tidal cycle. An upward-facing multifrequency Simrad EK60 echosounder (38, 120 and 200 kHz) is synchronized with an upward-facing Imagenex 837B Delta T multibeam sonar (120° × 20° beamwidth, 260 kHz) aligned with the tidal flow. An ADV is used for local current measurements and a fluorometer is used to measure chlorophyll (as a proxy for plankton) and turbidity. The platform is self-contained with no cables or anchors, facilitating rapid deployment and recovery in high-energy sites and flexibility in allowing baseline data to be gathered. Five 2-week deployments were completed in 2012 and 2013 at wave and tidal energy sites, both in the presence and absence of renewable energy structures. These surveys were conducted at the European Marine Energy Centre, Orkney, UK. Algorithms for noise removal, target detection and target tracking have been written using a combination of LabVIEW, MATLAB and Echoview. Target morphology, behavior and frequency response are used to aid target classification, with concurrent shore-based seabird observations used to ground truth the acoustic data. Using this information, the depth preference and interactions of birds, fish schools and marine mammals with renewable energy structures can be tracked. Seabird and mammal dive profiles, predator-prey interactions a- d the effect of hydrodynamic processes during foraging events throughout the water column can also be analyzed. These datasets offer insights into how fish, seabirds and marine mammals successfully forage within dynamic marine habitats and also whether individuals face collision risks with tidal stream turbines. Measurements from the subsea platform are complemented by 3D hydrodynamic model data and concurrent shore-based marine X-band radar. This range of concurrent fine-scale information across physical and trophic levels will improve our understanding of how the fine-scale physical influence of currents, waves and turbulence at tidal and wave energy sites affect the behavior of marine wildlife, and how tidal and wave energy devices might alter the behavior of such wildlife. Together, the results from these deployments increase our environmental understanding of the physical and ecological effects of installing and operating marine renewable energy devices. These results can be used to guide marine spatial planning, device design, licensing and operation, as individual devices are scaled up to arrays and new sites are considered. The combination of our current technology and analytical approach can help to de-risk the licensing process by providing a higher level of certainty about the behavior of a range of mobile marine species in high energy environments. It is likely that this approach will lead to greater mechanistic understanding of how and why mobile predators use these high energy areas for foraging. If a fuller understanding and quantification can be achieved at single demonstration scales, and these are found to be similar, then the predictive power of the outcomes might lead to a wider strategic approach to monitoring and possibly lead to a reduction in the level of monitoring required at each commercial site

A need for definition: a matter of life and death for human embryos

A recent IMJ commentaryon brain stem death criteria summarised ethical and technical issues concerning “end of life decisions”, and we concur that physicians should have competence in eliciting the proper sequence of brain stem signs in clinical practice. However, a truly comprehensive dialogue on the definition of death should address another question that confronts IVF clinics in Ireland each day—when does a human embryo die? Despite the enormous social and political energy focused on “right to life” issues over recent decades, the death of a human embryo remains a sadly forgotten topic. As Dr Murphy indicated1, the introduction of brain stem death criteria in 1967 recognised permanent loss of consciousness and spontaneous breathing after the inactivation of essential human neural elements. But our IVF clinics and allied research facilities are responsible for human life well before any discrete neurological system has developed. For practitioners and scientists engaged in the care of these tiniest of “patients”, a relevant definition of death should not be neglected

Novel ETHE1 mutation in a carrier couple having prior offspring affected with ethylmalonic encephalopathy: Genetic analysis, clinical management and reproductive outcome.

Ethylmalonic encephalopathy (EE) is an autosomally recessive inherited disorder with a relentlessly progressive decline in neurological function, usually fatal by the age of ten. It is characterised by generalised hypotonia, psychomotor regression, spastic tetraparesis, dystonia, seizures and, eventually, global neurological failure. Approximately 50 reports have been published worldwide describing this devastating disease, most involving patients of Mediterranean or Arab origin. The fundamental defect in EE likely involves the impairment of a mitochondrial sulphur dioxygenase coded by the ETHE1 gene responsible for the catabolism of sulphide, which subsequently accumulates to toxic levels. A diagnosis of EE should initiate careful genetic evaluation and counselling, particularly if the parents intend to have additional offspring. The present report describes the diagnosis of EE in a reproductive endocrinology context, where both members of a non-consanguineous couple were confirmed to be carriers of an identical A↷G mutation. This previously unknown mutation at nucleotide position c.494 resulted in an amino acid substitution, p.Asp165Gly. Although consideration was given to in vitro fertilisation, embryo biopsy and single gene pre-implantation genetic diagnosis, the couple decided to first utilise a less aggressive therapeutic approach with donor sperm insemination. Pregnancy with a low risk of EE was indeed achieved; however, the infant was affected with a different anomaly (hypoplastic left heart). As this case demonstrates, prior to the initiation of fertility therapy, genetic analysis may be used to provide a confirmatory diagnosis when EE is suspected

Commensurate-Incommensurate Magnetic Phase Transition in Magnetoelectric Single Crystal LiNiPO4_4

Neutron scattering studies of single-crystal LiNiPO$_4$ reveal a spontaneous first-order commensurate-incommensurate magnetic phase transition. Short- and long-range incommensurate phases are intermediate between the high temperature paramagnetic and the low temperature antiferromagnetic phases. The modulated structure has a predominant antiferromagnetic component, giving rise to satellite peaks in the vicinity of the fundamental antiferromagnetic Bragg reflection, and a ferromagnetic component giving rise to peaks at small momentum-transfers around the origin at $(0,\pm Q,0)$. The wavelength of the modulated magnetic structure varies continuously with temperature. It is argued that the incommensurate short- and long-range phases are due to spin-dimensionality crossover from a continuous to the discrete Ising state. These observations explain the anomalous first-order transition seen in the magnetoelectric effect of this system

First Irish delivery following sequential, two-stage embryo and blastocyst transfer.

BACKGROUND: The timing of embryo transfer (ET) after in vitro fertilisation (IVF) remains controversial, and there are no reliable guidelines available to prospectively identify which patients would benefit from either day-3 or blastocyst transfer. While blastocyst transfer is generally favoured over day-3 transfers, very few IVF patients get both in the same treatment cycle. CASE DESCRIPTION: We report on a 35.5-year-old female with tubal factor infertility who underwent IVF, which included transfer of a fresh day-3 embryo and a thawed blastocyst frozen at day 6. Transfer occurred on two separate days (days 3 and 6) in a two-stage/dual catheter fashion and resulted in a healthy term singleton livebirth. CONCLUSIONS: While combined day-3 and day-5 ET has been available elsewhere for several years, this is the first description of its successful application in Ireland and confirms the effectiveness of coordinated two-stage transfer in a single IVF treatment cycle

Rare isotope production in statistical multifragmentation

Producing rare isotopes through statistical multifragmentation is investigated using the Mekjian method for exact solutions of the canonical ensemble. Both the initial fragmentation and the the sequential decay are modeled in such a way as to avoid Monte Carlo and thus provide yields for arbitrarily scarce fragments. The importance of sequential decay, exact particle-number conservation and the sensitivities to parameters such as density and temperature are explored. Recent measurements of isotope ratios from the fragmentation of different Sn isotopes are interpreted within this picture.Comment: 10 eps figure

First Irish pregnancies after IVF with gestational carrier

In this report, our early experience with screening, monitoring and coordinating IVF utilising gestational carrier treatment is described. Although congenital and iatrogenic etiologies for uterine factor infertility manifest distinctly different reasons for considering a gestational carrier approach, we outline a unified management strategy for both conditions. One patient had congenital absence of the uterus and proximal vagina (Mayer-Rokitansky-Kuster-Hauser syndrome variant), while another patient presented post-hysterectomy and adjuvant brachytherapy for invasive squamous cervical carcinoma. Conception was established for both patients, the first pregnancies to be achieved using an IVF/gestational carrier technique in Ireland. As demonstrated here, selected patients with at least one intact ovary who suffer from uterine factor infertility can be excellent candidates for IVF with embryo transfer to a carefully screened gestational carrier. The role of individual and group counselling is reviewed; professional legal advice is prudent in complex cases