ESTIMATION OF WHEAT ACREAGE RESPONSE FUNCTIONS FOR THE NORTHWEST

Acreage response functions for wheat are fitted to aggregate data and pooled time-series and cross-sectional data for the Northwest. It was hypothesized that the pooled data approach provides a useful alternative to using aggregate data since it requires fewer timer-series observations for reliable parameter estimation and it does not require the assumption of constant acreage response elasticities throughout the region. The results of this study verify this hypothesis as well as indicate that regional response elasticities for Northwest wheat acreage may differ greatly from national estimates.Crop Production/Industries,

The Elegant Simplicity of Family Preservation Practice Legecies and Lessons

An earlier version of this manuscript was prepared for the Chapin Hall invitational seminar on family preservation, The Chapin Hall Center for Children at the University of Chicago, September 16 & 17, 1999. The author wishes to acknowledge the comments and helpful suggestions of seminar participants-Jacqueline McCroskey, Martha Shirk, Fran Jacobs, John Schuerman, Lee Schorr, Charlotte Booth, Kristi Nelson, Susan Kelly, Frank Farrow, and Susan Notkin. These comments, as indeed many of their prior contributions, have had a seminal effect on my thinking about family preservation services over the years. Clark Peters and other Chapin Hall staff deserve special thanks for creating the conditions necessary to produce a lively and productive discussion. As always, Harold Richman, Executive Director of Chapin Hall, and Hermon Dunlap, Smith Professor at the School of Social Service Administration of the University of Chicago, as seminar convenor combined perfectly the skills of gracious host and incisive critic. We in the child welfare field are in his debt for continually raising the level of discourse in our field. In the end, as it should be, the thoughts and opinions in the following paper are wholly my own

A new Q-matrix in the Eight-Vertex Model

We construct a $Q$-matrix for the eight-vertex model at roots of unity for crossing parameter $\eta=2mK/L$ with odd $L$, a case for which the existing constructions do not work. The new $Q$-matrix \Q depends as usual on the spectral parameter and also on a free parameter $t$. For $t=0$ \Q has the standard properties. For $t\neq 0$, however, it does not commute with the operator $S$ and not with itself for different values of the spectral parameter. We show that the six-vertex limit of \Q(v,t=iK'/2) exists.Comment: 10 pages section on quasiperiodicity added, typo corrected, published versio

Coordinate-invariant Path Integral Methods in Conformal Field Theory

We present a coordinate-invariant approach, based on a Pauli-Villars measure, to the definition of the path integral in two-dimensional conformal field theory. We discuss some advantages of this approach compared to the operator formalism and alternative path integral approaches. We show that our path integral measure is invariant under conformal transformations and field reparametrizations, in contrast to the measure used in the Fujikawa calculation, and we show the agreement, despite different origins, of the conformal anomaly in the two approaches. The natural energy-momentum in the Pauli-Villars approach is a true coordinate-invariant tensor quantity, and we discuss its nontrivial relationship to the corresponding non-tensor object arising in the operator formalism, thus providing a novel explanation within a path integral context for the anomalous Ward identities of the latter. We provide a direct calculation of the nontrivial contact terms arising in expectation values of certain energy-momentum products, and we use these to perform a simple consistency check confirming the validity of the change of variables formula for the path integral. Finally, we review the relationship between the conformal anomaly and the energy-momentum two-point functions in our formalism.Comment: Corrected minor typos. To appear in International Journal of Modern Physics

How can we help novice child protection social workers to see situations like experienced practitioners? A randomised controlled trial evaluation of the ShadowBox™ method using pre-recorded video feedback

Background Protecting children for abuse and neglect is a complex area of decision-making but frequent staff turnover has meant that many frontline child protection social workers are often relatively inexperienced. The ShadoxBoxTM method is an educational intervention that enables novice practitioners to gain decision-making skills quickly. Aim: This study was an RCT evaluation of an educational intervention for novice social workers that used the ShadoxBoxTM method adapted to include pre-recorded video feedback from an expert panel to test whether novice decision making would become more similar to experienced practitioners. Methods: The study was an RCT in which participants completed complex scenarios in a computer lab in control and intervention groups. The training method involved participants receiving feedback from highly experienced practitioners at each decision point within the scenarios. The intervention group received pre-recorded video feedback from a panel of highly experienced practitioners while the control group received no feedback. Participants and Setting Participants (n=83) were trainee social workers from a London university randomly allocated to control and intervention groups. Data was collected on computer stations using Qualtrics. Results Undertaking the scenarios improved both groups but greater improvement was seen in participants who had received video feedback from a panel of experienced practitioners. The results were promising, with participant accuracy increasing by 44% (from 31% to 75%) in the intervention group compared to an increase of 31% (from 32% to 63%) in the control group. Considerable improvements were noted in both intervention and control groups, which suggest that scenario-based interventions can be a promising educational method as learning is rooted in real life scenarios and participants have the opportunity to reflect upon their decisions. The qualitative findings are that novice participants make predictable errors, including: • Making shallow assumptions • Focusing exclusively on the parents rather than the child. • Jumping to early conclusions with insufficient information. Conclusions • ShadoxBoxTM training appears to be a promising intervention for improving decision making. • Novices benefitted from having concentrated exposure to complex scenarios focused on assessing risk and making professional judgements. • When this was augmented by direct feedback from a panel of highly experienced practitioners, these benefits were increased considerably. • The complexity of the scenarios also exposed the novices to real life pressures rather than the simplified versions used in decision research

Exploring the impact of varying definitions of exacerbations of chronic obstructive pulmonary disease in routinely collected electronic medical records

Background: Validity of exposure and outcome measures in electronic medical records is vital to ensure robust, comparable study findings however, despite validation studies, definitions of variables used often differ. Using exacerbations of chronic obstructive pulmonary disease (COPD) as an example, we investigated the impact of potential misclassification of different definitions commonly used in publications on study findings. Methods: A retrospective cohort study was performed. English primary care data from the Clinical Practice Research Datalink Aurum database with linked secondary care data were used to define a population of COPD patients ≥40 years old registered at a general practice. Index date was the date eligibility criteria were met and end of follow-up was 30/12/19, death or end of data collection. Exacerbations were defined using 6 algorithms based on definitions commonly used in the literature, including one validated definition. For each algorithm, the proportion of frequent exacerbators (≥2 exacerbations/year) and exacerbation rates were described. Cox proportional hazard regression was used to investigate each algorithm on the association between heart failure and risk of COPD exacerbation. Findings: A total of 315,184 patients were included. Baseline proportion of frequent exacerbators varied from 2.7% to 15.3% depending on the algorithm. Rates of exacerbations over follow-up varied from 19.3 to 66.6 events/100 person-years. The adjusted hazard ratio for the association between heart failure and exacerbation varied from 1.45, 95% confidence intervals 1.42–1.49, to 1.01, 0.98–1.04. Interpretation: The use of high validity definitions and standardisation of definitions in electronic medical records is crucial to generating high quality, robust evidence

Harmonic Maa{\ss}-Jacobi forms of degree 1 with higher rank indices

We define and investigate real analytic weak Jacobi forms of degree 1 and arbitrary rank. En route we calculate the Casimir operator associated to the maximal central extension of the real Jacobi group, which for rank exceeding 1 is of order 4. In ranks exceeding 1, the notions of H-harmonicity and semi-holomorphicity are the same.Comment: 28 page

Effect of nanoholes on the plasmonic properties of star nanostructures

The transmission and localized electric field distribution of nanostructures are the most important parameters in the plasmonic field for nano-optics and nanobiosensors. In this paper, we propose a novel nanostructure which may be used for nanobiosensor applications. The effect of nanoholes on the plasmonic properties of star nanostructure was studied via numerical simulation, using the finite-difference time-domain (FDTD) method. In the model, the material type and size of the nanostructures was fixed, but the distance between the monotor and the surface of the nanoholes was varied. For example, nanoholes were located in the center of the nanostructures. The simulation method was as follows. Initially, the wavelength of incident light was varied from 400 to 1200 nm and the transmission spectrum and the electric field distribution were simulated. Then at the resonance wavelength (wavelength where the transmission spectrum has a minimum), the localized electric field distribution was calculated at different distances from the surface of the nanostructures. This study shows that the position of nanoholes has a significant effect on the transmission and localized electric field distribution of star nanostructures. The condition for achieving the maximum localized electric field distribution can be used in nano-optics and nanobiosensors in the future

The Heun equation and the Calogero-Moser-Sutherland system V: generalized Darboux transformations

We obtain isomonodromic transformations for Heun's equation by generalizing Darboux transformation, and we find pairs and triplets of Heun's equation which have the same monodromy structure. By composing generalized Darboux transformations, we establish a new construction of the commuting operator which ensures finite-gap property. As an application, we prove conjectures in part III.Comment: 24 page

Family memories in the home: contrasting physical and digital mementos

We carried out fieldwork to characterise and compare physical and digital mementos in the home. Physical mementos are highly valued, heterogeneous and support different types of recollection. Contrary to expectations, we found physical mementos are not purely representational, and can involve appropriating common objects and more idiosyncratic forms. In contrast, digital mementos were initially perceived as less valuable, although participants later reconsidered this. Digital mementos were somewhat limited in function and expression, largely involving representational photos and videos, and infrequently accessed. We explain these digital limitations and conclude with design guidelines for digital mementos, including better techniques for accessing and integrating these into everyday life, allowing them to acquire the symbolic associations and lasting value that characterise their physical counterparts