Moral hazard and the division of labor in agricultural land leases

land lease contracts, moral hazard, contract duration, division of labor, Land Economics/Use,

Rapid generation of angular momentum in bounded magnetized plasma

Direct numerical simulations of two-dimensional decaying MHD turbulence in bounded domains show the rapid generation of angular momentum in nonaxisymmetric geometries. It is found that magnetic fluctuations enhance this mechanism. On a larger time scale, the generation of a magnetic angular momentum, or angular field, is observed. For axisymmetric geometries, the generation of angular momentum is absent; nevertheless, a weak magnetic field can be observed. The derived evolution equations for both the angular momentum and angular field yield possible explanations for the observed behavior

Sustainable coastal social-ecological systems: how do we define “coastal”?

Coastal social-ecological systems (SES) are home to over 500 million people and one of the most productive and diverse ecosystems in the world. In recent years, coastal SES are experiencing severe threat from an increasing population, resource exploitation, and global environmental change (e.g. climate change), which have devastating societal impacts in coastal areas. Despite several global, national, and local initiatives, there is a growing consensus that coastal resources are depleting and increasing conflicts in coastal areas. Recognizing the global call to understand social–ecological interactions for implementing development practices, this special issue features a suite (seven) of articles advancing the understanding of the sustainability of social and ecological interactions within coastal areas through theoretical SES approaches and related analytical methods. In this editorial of this special issue, we also argued that coastal area needs to define from SES perspectives, which have received less attention compared to ecological and social perspectives. We hope that this special issue will stimulate the debate and further thinking of how coastal SES can be managed sustainably by conceptualizing and understanding the complex dynamics (interaction, feedback) of SES

Background independent quantization and the uncertainty principle

It is shown that polymer quantization leads to a modified uncertainty principle similar to that obtained from string theory and non-commutative geometry. When applied to quantum field theory on general background spacetimes, corrections to the uncertainty principle acquire a metric dependence. For Friedmann-Robertson-Walker cosmology this translates to a scale factor dependence which gives a large effect in the early universe.Comment: 6 page

Heavy fermion behavior in PrRh2B2C: Excitonic mass enhancement

We report magnetic and transport properties of a new quaternary borocarbide PrRh$_{2}$B$_{2}$C, based on magnetisation, resistivity and specific heat studies. This compound forms in LuNi$_{2}$B$_{2}$C-type tetragonal structure (space group {\it I4/mmm}) and does not exhibit magnetic ordering or superconductivity down to 0.5 K. The crystal field analysis of specific heat data suggests a singlet ground state in this compound. The high value of the Sommerfeld coefficient, $\gamma$ $\approx$ 250 mJ/mole K$^{2}$, together with a singlet ground state suggests that the heavy fermion behaviour in PrRh$_{2}$B$_{2}$C results from the interaction of the conduction electrons with the low lying crystal field excitations. No signature of magnetic ordering or superconductivity is observed in PrRh$_{2}$B$_{2}$C under the application of pressure up to 23 kbar.Comment: 10 pages, 5 figure

Effective State Metamorphosis in Semi-Classical Loop Quantum Cosmology

Modification to the behavior of geometrical density at short scales is a key result of loop quantum cosmology, responsible for an interesting phenomenology in the very early universe. We demonstrate the way matter with arbitrary scale factor dependence in Hamiltonian incorporates this change in its effective dynamics in the loop modified phase. For generic matter, the equation of state starts varying near a critical scale factor, becomes negative below it and violates strong energy condition. This opens a new avenue to generalize various phenomenological applications in loop quantum cosmology. We show that different ways to define energy density may yield radically different results, especially for the case corresponding to classical dust. We also discuss implications for frequency dispersion induced by modification to geometric density at small scales.Comment: Revised version; includes expanded discussion of natural trans-Planckian modifications to frequency dispersion and robustness to quantization ambiguities. To appear in Class. Quant. Gra

First year nursing students use of social media within education: results of a survey

Introduction – Social media rapidly disseminates information but is a controversial learning platform in nurse education. This study aimed to explore how students viewed the use of Twitter, and other social media, in their first year of a nursing degree. Aim - The aim of this study was to evaluate first year student nurses’ use of social media, before and after commencing a pre-registration programme, where Twitter was used in a module Methodology – A cross-sectional approach using a descriptive survey was completed. Methods – An online survey, that included Likert scale and open questions, was open for one month in 2016 Sample – All students on Nursing Undergraduate Degrees, in Adult, Child and Mental Health, who were in the first year of their programme were eligible to participate. 121 students took part with a response rate of 32%. Results –Most students were positive about using social media as they found it an engaging way to promote discussion and share information. Students use of Twitter changed in the first year with 19.8% using it once or more per week on commencement of the programme which increased to 45.5%; other social media platforms remained static. Most students (57.8%) understood the purpose of using Twitter although 14% reported that it was not used within their module; thus, not all students gained experience of using the social media. 81% of students said that using Twitter had been beneficial to increase awareness of nursing issues within their course. However, there were areas that students found difficult such as time, and not knowing what to say. Conclusion –The study suggests that teaching about social media, and incorporating it into learning activities, may be beneficial for students. However, more research into the subject using an experimental design to assess changes over time would be useful

Self-organization in turbulence as a route to order in plasma and fluids

Transitions from turbulence to order are studied experimentally in thin fluid layers and magnetically confined toroidal plasma. It is shown that turbulence self-organizes through the mechanism of spectral condensation. The spectral redistribution of the turbulent energy leads to the reduction in the turbulence level, generation of coherent flow, reduction in the particle diffusion and increase in the system's energy. The higher order state is sustained via the nonlocal spectral coupling of the linearly unstable spectral range to the large-scale mean flow. The similarity of self-organization in two-dimensional fluids and low-to-high confinement transitions in plasma suggests the universality of the mechanism.Comment: 5 pages, 4 figure