Exploring Agricultural Production Systems and Their Fundamental Components with System Dynamics Modelling

Agricultural production in the United States is undergoing marked changes due to rapid shifts in consumer demands, input costs, and concerns for food safety and environmental impact. Agricultural production systems are comprised of multidimensional components and drivers that interact in complex ways to influence production sustainability. In a mixed-methods approach, we combine qualitative and quantitative data to develop and simulate a system dynamics model that explores the systemic interaction of these drivers on the economic, environmental and social sustainability of agricultural production. We then use this model to evaluate the role of each driver in determining the differences in sustainability between three distinct production systems: crops only, livestock only, and an integrated crops and livestock system. The result from these modelling efforts found that the greatest potential for sustainability existed with the crops only production system. While this study presents a stand-alone contribution to sector knowledge and practice, it encourages future research in this sector that employs similar systems-based methods to enable more sustainable practices and policies within agricultural production

Trends in incidence of recorded diagnosis of osteoporosis, osteopenia, and fragility fractures in people aged 50 years and above: retrospective cohort study using UK primary care data

Summary: This study used primary care data to estimate the incidence of recorded diagnosis of osteoporosis, osteopenia, and fragility fracture in the UK during 2000–2018 accounting for age, sex, calendar year and social deprivation. More than 3 million people aged 50–99 years were included. We found that men living in the most deprived areas had a 45% higher risk of being diagnosed with osteoporosis and 50% higher risk of fragility fracture compared to men living in the least deprived areas. Purpose: a) To estimate the incidence trends of a recorded diagnosis of osteoporosis, osteopenia, and fragility fracture in the UK over time; b) to describe differences according to age, sex, and social deprivation. Methods: This is a longitudinal population-based cohort study using routinely collected primary care data obtained via IQVIA Medical Research Database (IMRD). All patients aged 50–99 years registered with a practice participating in THIN (The Health Improvement Network) between 2000–2018 were included. The first recorded diagnosis of osteoporosis, osteopenia, or fragility fracture was used to estimate incidence rates (IR) per 10,000 person-years at risk. Poisson regression was used to provide Incidence Rate Ratios (IRR) adjusted by age, sex, social deprivation, calendar year, and practice effect. Results: The year-specific adjusted IRR of recorded osteoporosis was highest in 2009 in women [IRR 1.44(95%CI 1.38–1.50)], whereas in men it was highest in 2013–2014 [IRR 1.94(95%CI 1.72–2.18)] compared to 2000. The year-specific adjusted IRR of fragility fracture was highest in 2012 in women [IRR 1.77(95%CI 1.69–1.85)], whereas in men it was highest in 2013 [IRR 1.64(95%CI 1.51–1.78)] compared to 2000. Men in the most deprived areas had a higher risk of being diagnosed with osteoporosis [IRR 1.45(95%CI 1.38–1.53)], osteopenia [IRR 1.17(95%CI 1.09–1.26)], and fragility fracture [IRR 1.50(95%CI 1.44–1.56)] compared to those living in the least deprived areas, but smaller differences were seen in women. Conclusion: Use of fracture risk assessment tools may enhance the detection of osteoporosis cases in primary care. Further research is needed on the effect of social deprivation on diagnosis of osteoporosis and fractures

Rapidly decaying supernova 2010X: A candidate ".Ia" explosion

We present the discovery, photometric, and spectroscopic follow-up observations of SN 2010X (PTF 10bhp). This supernova decays exponentially with τ_d = 5 days and rivals the current recordholder in speed, SN 2002bj. SN 2010X peaks at M_r = −17 mag and has mean velocities of 10,000 km s^(−1). Our light curve modeling suggests a radioactivity-powered event and an ejecta mass of 0.16M_⊙. If powered by Nickel, we show that the Nickel mass must be very small (≈0.02 M_⊙) and that the supernova quickly becomes optically thin to γ -rays. Our spectral modeling suggests that SN 2010X and SN 2002bj have similar chemical compositions and that one of aluminum or helium is present. If aluminum is present, we speculate that this may be an accretion-induced collapse of an O-Ne-Mg white dwarf. If helium is present, all observables of SN 2010X are consistent with being a thermonuclear helium shell detonation on a white dwarf, a “.Ia” explosion. With the 1 day dynamic-cadence experiment on the Palomar Transient Factory, we expect to annually discover a few such events

Foundations of space-time finite element methods: polytopes, interpolation, and integration

The main purpose of this article is to facilitate the implementation of space-time finite element methods in four-dimensional space. In order to develop a finite element method in this setting, it is necessary to create a numerical foundation, or equivalently a numerical infrastructure. This foundation should include a collection of suitable elements (usually hypercubes, simplices, or closely related polytopes), numerical interpolation procedures (usually orthonormal polynomial bases), and numerical integration procedures (usually quadrature rules). It is well known that each of these areas has yet to be fully explored, and in the present article, we attempt to directly address this issue. We begin by developing a concrete, sequential procedure for constructing generic four-dimensional elements (4-polytopes). Thereafter, we review the key numerical properties of several canonical elements: the tesseract, tetrahedral prism, and pentatope. Here, we provide explicit expressions for orthonormal polynomial bases on these elements. Next, we construct fully symmetric quadrature rules with positive weights that are capable of exactly integrating high-degree polynomials, e.g. up to degree 17 on the tesseract. Finally, the quadrature rules are successfully tested using a set of canonical numerical experiments on polynomial and transcendental functions.Comment: 34 pages, 18 figure

A Model for Assessing the Visual Resources of River Basins as an Aid to Making Landuse Planning Decisions

The visual quality of a river basin and its associated properties can be identified, evaluated and integrated into the landscape planning process. The model developed provides a quantitative methodology for determining visual quality on the basis of available Geographic Information System factors. These factors are utilized to develop the preference attributes, COLOR, FORM, TEXTURE and LINE, which are associated with the assessment of visual quality. The preference attributes are then combined through a decision making process into a continuum of DISTINCTIVE, GOOD, AVERAGE and MINIMAL visual quality and is expressed digitally in map format. By providing visual quality information in a digital format it can be treated as a discrete component of the planning process similar to physical, cultural and economic attributes

Interactivity:the missing link between virtual reality technology and drug discovery pipelines

The potential of virtual reality (VR) to contribute to drug design and development has been recognised for many years. Hardware and software developments now mean that this potential is beginning to be realised, and VR methods are being actively used in this sphere. A recent advance is to use VR not only to visualise and interact with molecular structures, but also to interact with molecular dynamics simulations of 'on the fly' (interactive molecular dynamics in VR, IMD-VR), which is useful not only for flexible docking but also to examine binding processes and conformational changes. iMD-VR has been shown to be useful for creating complexes of ligands bound to target proteins, e.g., recently applied to peptide inhibitors of the SARS-CoV-2 main protease. In this review, we use the term 'interactive VR' to refer to software where interactivity is an inherent part of the user VR experience e.g., in making structural modifications or interacting with a physically rigorous molecular dynamics (MD) simulation, as opposed to simply using VR controllers to rotate and translate the molecule for enhanced visualisation. Here, we describe these methods and their application to problems relevant to drug discovery, highlighting the possibilities that they offer in this arena. We suggest that the ease of viewing and manipulating molecular structures and dynamics, and the ability to modify structures on the fly (e.g., adding or deleting atoms) makes modern interactive VR a valuable tool to add to the armoury of drug development methods.Comment: 19 pages, 3 figure