Systematic and Unsystematic Risk Costs for Southeastern Kansas Farm Enterprises

Six measures of farm returns are used to estimate the most "appropriate" market index for southeastern Kansas farms. Systematic and nonsystematic risks and risk costs are estimated for farm planning. Results suggest that regional indices are more appropriate for use as the market index than state indices.international trade, vector autoregressions, wheat markets, Farm Management,

RISK COSTS AND THE CHOICE OF MARKET RETURN INDEX

Six measures of returns are used to estimate the most "“appropriate"” market index for southeast Kansas farms. Results suggest that localized indices are more appropriate than state indices for use as the market index. The appropriate index was used to estimate systematic and nonsystematic risk and risk costs for farm planning. Estimated risks depend on the choice of market index, whereas risk costs depend on the index choice and the risk aversion are considered. More risk-averse specialized farmers are not completely compensated for risk.Farm Management, Risk and Uncertainty,

Estimation of Helmert Orthometric Heights Using Digital Barcode Levelling, Observed Gravity and Topographic Mass-Density Data Over Part of the Darling Scarp, Western Australia

The normal orthometric corrections used in the 1971 establishment of the Australian Height Datum (AHD) do not properly account for local variations in the Earth?s gravity field. Therefore, Helmert orthometric heights have been computed over a spirit-levelled height traverse over part of the Darling Fault and compared with normal orthometric heights. This involves a measured height change of ~175m, a measured gravity change of ~34mGal, and an estimated change in topographic mass-density of 480kgm-3. The computed Helmert orthometric correction reaches -4.8mm between the end-points of the traverse, whereas the normal orthometric correction only reaches 0.1mm. However, computing the corrections over each bay in the traverse gives totals over the entire traverse of -0.8 mm for the Helmert orthometric corrections and 0.2 mm for the normal orthometric corrections. A difference of 0.1 mm was observed between the Helmert orthometric corrections computed with constant and variable topographic mass-density models. It is recommended that orthometric corrections, which take into account observed gravity and topographic mass-density, be considered in any future redefinition of the AHD

Nonlinear subsidence at Fremantle, a long-recording tide gauge in the Southern Hemisphere

© 2015 The Authors. A combination of independent evidence (continuous GPS, repeat geodetic leveling, groundwater abstraction, satellite altimetry, and tide gauge (TG) records) shows that the long-recording Fremantle TG has been subsiding in a nonlinear way since the mid-1970s due to time-variable groundwater abstraction. The vertical land motion (VLM) rates vary from approximately -2 to -4 mm/yr (i.e., subsidence), thus producing a small apparent acceleration in mean sea level computed from the Fremantle TG records. We exemplify that GPS-derived VLM must be geodetically connected to the TG to eliminate the commonly used assumption that there is no differential VLM when the GPS is not colocated with the TG. In the Perth Basin, we show that groundwater abstraction can be used as a diagnostic tool for identifying nonlinear VLM that is not evident in GPS time series alone. Key Points: The Fremantle tide gauge is and has been subsiding in a nonlinear way Exemplar of the need for geodetic connection between tide gauge and GPS station Groundwater has been used as a diagnostic for nonlinear vertical land movement

Impact of stochastic modelling on GPS height and zenith wet delay estimation

Most stochastic modelling techniques assume the physical correlations among the raw observations to be negligible when forming the variance covariance matrix of the GPS observations. Such an assumption may, however, lead to significantly biased solutions. The Minimum Norm Quadratic Unbiased Estimation (MINQUE) method is an iterative technique that can be used to estimate spatial correlation among GPS measurements. Studies by previous authors have shown that MINQUE improves the accuracy and the reliability of the ambiguity resolution, and ultimately, the geodetic solution. However, its effect on the estimation of zenith wet delay (ZWD) is somewhat unknown. In this paper, an investigation into its impact on ZWD, as well as heighting, is carried out using simulated data. The results obtained from MINQUE for an observation window of five-days in static mode indicate an average improvement of 51% and 71% in the station height precision when compared against elevation-angle dependent and equal weighting models, respectively. This development, however, did not translate into better ZWD estimation, for which the differences between each respective stochastic model are generally at the sub-millimetre level

Autistic adults’ experiences of managing wellbeing and implications for social prescribing

doi: 10.1080/09687599.2023.2263628Autistic people demonstrate poor outcomes on objective measures of wellbeing, yet research centring lived experience provides a more nuanced picture. There is growing support for person-centred, holistic and community approaches to enhancing wellbeing for autistic people. Social prescribing may be one such approach. This qualitative study explored the concept of wellbeing for autistic adults – including barriers and self-management – and the implications of this for modifying social prescribing. It involved semi-structured interviews with 21 autistic adults in the UK. Reflexive thematic analysis of the data supports research suggesting that self-determination may underlie many aspects of wellbeing for autistic people. The COVID-19 pandemic provided new opportunities to develop wellbeing strategies but also had negative impacts. Social prescribing could promote self-determination by signposting autistic people to peer support opportunities building on intrinsic interests

Anthropogenic land subsidence in the Perth Basin: Challenges for its retrospective geodetic detection

Recent-past subsidence of parts of the Perth Basin has most probably been caused by increased groundwater extraction for domestic and agricultural use. However, no dedicated geodetic monitoring programs were established when the increased extraction began in around 2000, thus setting a challenge to retrospectively quantify and map the subsidence. Differential levelling is likely to be less effective as only a few repeat traverses cover the areas thought to be subsiding. Repeat gravimetry is totally ineffective because of microseismic vibrations propagating through the Perth Basin. Repeat episodic GPS (Global Positioning System) is also likely to be less effective because of the few station occupations over several days or weeks and the inherent weakness of GPS for height determination. However, from a continuously operating GPS receiver at Gnangara and nearby artesian monitoring boreholes, we show that the rate of land subsidence has slowed from about -6 mm/yr to about -2 mm/yr since the reduction of groundwater extraction from the Yarragadee Aquifer in around 2005. A promising technique is InSAR (interferometric synthetic aperture radar) because it can map large areas, but the lack of historical radar imagery over the period of increased subsidence is a hindrance

Using AUSGeoid2020 and its error grids in surveying computations

We present summarised formulas and worked examples for the propagation of geoid and vertical deflection errors through some common geodetic surveying computations, as well as a demonstration of their effects on least squares adjustments of small simulated geodetic networks. We also present location-specific uncertainties for the vertical deflections derived from the horizontal gradients of the AGQG2017 gravimetric-only quasigeoid model, upon which AUSGeoid2020 is based

Using Meta-Ethnography to Synthesize Relevant Studies: Capturing the Bigger Picture in Dementia with Challenging Behavior within Families

In understanding the range and depth of people’s experiences, it is important to include the wide range of approaches which capture the richness within a given knowledge base. However, systematic reviews using quantitative data alone risk missing findings that can contribute to a better understanding of a research question. In response, meta-ethnography has emerged as a potentially useful method to synthesize and integrate both qualitative and quantitative data from different perspectives using qualitative methodology. In this case study, we describe how we have used meta-ethnography to better understand how families experience dementia. We address a particular issue of selecting the highest quality evidence across a range of epistemologies