Driving superfluidity with photoassociation

We theoretically examine photoassociation of a two-component Fermi degenerate gas. Our focus is on adjusting the atom-atom interaction, and thereby increasing the critical temperature of the BCS transition to the superfluid state. In order to avoid spontaneous decay of the molecules, the photoassociating light must be far-off resonance. Very high light intensities are therefore required for effective control of the BCS transition.Comment: 7 (preprint) pages; submitted to Optics Expres

An analysis of policy development within the Centre for Adult Education at the University of Natal (1971-1991)

Bibliography: pages 181-189.The construction of macro level policy is made more difficult by the absence of a reservoir of analytical accounts which raise issues which policy at that level must address. This study is concerned with the development of policy within a very specific context and as such it is a modest and limited contribution to the development of that reservoir of theorised practice of adult education in South Africa. In this it is both a documentary record of the development of adult education at the University of Natal and an exploration of the dynamics of the policies which were evolved to direct that development. The study is thus a descriptive and analytical account of the work of the Centre for Adult Education at the University of Natal over the 20 year period from 1971 to 1991 set against the context of the broad development of adult education in South Africa in general and developments in university based adult education development in particular

Uniqueness Typing for Resource Management in Message-Passing Concurrency

We view channels as the main form of resources in a message-passing programming paradigm. These channels need to be carefully managed in settings where resources are scarce. To study this problem, we extend the pi-calculus with primitives for channel allocation and deallocation and allow channels to be reused to communicate values of different types. Inevitably, the added expressiveness increases the possibilities for runtime errors. We define a substructural type system which combines uniqueness typing and affine typing to reject these ill-behaved programs

Capturing Economic Rents From Resources Through Royalties and Taxes

Oil price fluctuations, concerns over the division of resource revenues, and unconventional oil and gas developments are forcing governments to confront the same issue: how to design optimal royalty and corporate tax systems that bring in a publicly acceptable share of revenues without discouraging private investment. This paper surveys tax and royalty systems across six countries, as well as four US states and five Canadian provinces, offering concise analyses of their strengths and shortcomings to describe the best and simplest approaches to both. As in a public-private partnership, government owns the resources and allows private agents to maximize the rents resources generate. An optimal royalty system will thus be rent-based, ensuring that both owner and agent obtain maximally competitive returns so that each has incentives to continue the partnership. Such a system will also be simple, making compliance easy, manipulation difficult, and risks affordable. And it will be stable, instilling in the private sector the confidence needed to invest for the long term. As for corporate income taxes, they should be neutral across business activities, and applied at equal effective rates on economic income, to avoid distorting market forces through subsidies or needless complexity. A clean rent-based tax that allows all costs incurred by producers to be expensed or carried over, along with a corporate income tax system shorn of many of the preferences that negatively affect business activity, should be the way forward for any government looking to update their fiscal regimes for the 21st century

American Association of Physicists in Medicine Radiation Therapy Committee Task Group 53: Quality assurance for clinical radiotherapy treatment planning

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134846/1/mp8373.pd

Improving Benefit-harm Assessment of Therapies from the Patient Perspective: OMERACT Premeeting Toward Consensus on Core Sets for Randomized Controlled Trials

Objective: Outcome Measures in Rheumatology (OMERACT) convened a premeeting in 2018 to bring together patients, regulators, researchers, clinicians, and consumers to build upon previous OMERACT drug safety work, with patients fully engaged throughout all phases. Methods: Day 1 included a brief introduction to the history of OMERACT and methodology, and an overview of current efforts within and outside OMERACT to identify patient-reported medication safety concerns. On Day 2, two working groups presented results; after each, breakout groups were assembled to discuss findings. Results: Five themes pertaining to drug safety measurement emerged. Conclusion: Current approaches have failed to include data from the patient’s perspective. A better understanding of how individuals with rheumatic diseases view potential benefits and harms of therapies is essential

Fluid release from the subducted Cocos plate and partial melting of the crust deduced from magnetotelluric studies in southern Mexico: implications for the generation of volcanism and subduction dynamics

In order to study electrical conductivity phenomena that are associated with subduction related fluid release and melt production, magnetotelluric (MT) measurements were carried out in southern Mexico along two coast to coast profiles. The conductivity-depth distribution was obtained by simultaneous two-dimensional inversion of the transverse magnetic and transverse electric modes of the magnetotelluric transfer functions. The MT models demonstrate that the plate southern profile shows enhanced conductivity in the deep crust. The northern profile is dominated by an elongated conductive zone extending >250 km below the Trans-Mexican Volcanic Belt (TMVB). The isolated conductivity anomalies in the southern profile are interpreted as slab fluids stored in the overlying deep continental crust. These fluids were released by progressive metamorphic dehydration of the basaltic oceanic crust. The conductivity anomalies may be related to the main dehydration reactions at the zeolite → blueschist → eclogite facies transitions and the breakdown of chlorite. This relation allows the estimation of a geothermal gradient of ∼8.5°C/km for the top of the subducting plate. The same dehydration reactions may be recognized along the northern profile at the same position relative to the depth of the plate, but more inland due to a shallower dip, and merge near the volcanic front due to steep downbending of the plate. When the oceanic crust reaches a depth of 80–90 km, ascending fluids produce basaltic melts in the intervening hot subcontinental mantle wedge that give rise to the volcanic belt. Water-rich basalts may intrude into the lower continental crust leading to partial melting. The elongated highly conductive zone below the TMVB may therefore be caused by partial melts and fluids of various origins, ongoing migmatization, ascending basaltic and granitic melts, growing plutons as well as residual metamorphic fluids. Zones of extremely high conductance (>8000 S) in the continental crust on either MT profile might indicate extinct magmatism

Threatened North African seagrass meadows have supported green turtle populations for millennia

"Protect and restore ecosystems and biodiversity" is the second official aim of the current UN Ocean Decade (2021 to 2030) calling for the identification and protection of critical marine habitats. However, data to inform policy are often lacking altogether or confined to recent times, preventing the establishment of long-term baselines. The unique insights gained from combining bioarchaeology (palaeoproteomics, stable isotope analysis) with contemporary data (from satellite tracking) identified habitats which sea turtles have been using in the Eastern Mediterranean over five millennia. Specifically, our analysis of archaeological green turtle (Chelonia mydas) bones revealed that they likely foraged on the same North African seagrass meadows as their modern-day counterparts. Here, millennia-long foraging habitat fidelity has been directly demonstrated, highlighting the significance (and long-term dividends) of protecting these critical coastal habitats that are especially vulnerable to global warming. We highlight the potential for historical ecology to inform policy in safeguarding critical marine habitats