The Evolution of Inefficiency in USDA’s Forecasts of U.S. and World Soybean Markets

We derive a set of stylized facts about USDA’s soybean supply and demand forecasts and draw implications from these results for efforts to improve the accuracy of these forecasts. USDA’s short run soybean supply and demand forecasts are inefficient, with several key variables significantly biased throughout much of the annual forecast cycle. Bias and other characteristics have varied significantly over recent decades, and evaluation efforts intended to guide forecast improvement need to focus on very recent sample years and seasonally disaggregated data. USDA should expand the information set used in its forecasting of U.S. soybean yields, take note of its mid-season downward bias in its Brazilian production forecasts, and shift the weight of its early-season focus for China’s soybean consumption estimates towards forecasts of growth rates and reduce the weight it applies to forecasting consumption and trade by China in terms of levels. During 2004-2015, downward-biased U.S. production forecasts and upward-biased foreign excess supply forecasts resulted in downward-biased U.S. export forecasts throughout much of USDA’s annual forecasting cycle. Twenty years earlier, this downward bias was confined to the end of the forecasting cycle, whereas U.S. soybean ending stock forecasts have been upward biased for decades across much of the forecasting cycle. The forecasts for U.S. soybean exports are also characterized by smoothing, with strong correlation between month-to-month forecast revisions towards the later months of USDA’s annual forecasting cycle

Synthesis of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) derivatives functionalised with two, four or eight hydroxyl groups

Short synthetic routes to a range of BEDT-TTF derivatives functionalised with two, four or eight hydroxyl groups are reported, of interest because of their potential for introducing hydrogen bonding between donor and anion into their radical cation salts. The cycloaddition of 1,3-dithiole-2,4,5-trithione with alkenes to construct 5,6-dihydro-1,3-dithiolo[4,5-b]1,4-dithiin-2-thiones is a key step, with homo- or hetero-coupling procedures and O-deprotection completing the syntheses. The first synthesis of a single diastereomer of tetrakis(hydroxymethyl)BEDT-TTF, the cis, trans product, was achieved by careful choice of O-protecting groups to facilitate separation of homo- and hetero-coupled products. Cyclisation of the trithione with enantiopure 1R,2R,5R,6R-bis(O,O-isopropylidene)hex-3-ene-1,2,5,6-tetrol (from D-mannitol) gave two separable diastereomeric thiones, which can be transformed to enantiomeric BEDT-TTF derivatives with four or eight hydroxyl groups

From teaching physics to teaching children : beginning teachers learning from pupils

This paper discusses the development of beginning physics teachers' pedagogical content knowledge (PCK) in the context of teaching basic electricity during a one-year Professional Graduate Diploma in Education course (PGDE) and beyond. This longitudinal study used repeated semi-structured interviews over a period of four-and-a-half years. The interview schedule followed a line of development through the secondary school electrical syllabus in Scotland. Fifteen student teachers were interviewed during the PGDE year. Six of them were followed up at the end of the Induction Year (their first year as a newly qualified teacher), and again two-and-a-half years later. Thematic analysis of the interviews showed that before the beginning teachers had taught any classes, their initial focus was on how to transform their own subject matter knowledge (SMK) about electricity into forms that were accessible to pupils. As the beginning teachers gained experience working with classes, they gave vivid descriptions of interacting with particular pupils when teaching electricity which showed the development of their pedagogical knowledge. This played a significant role in the teachers' change of focus from teaching physics to teaching children as they transformed their SMK into forms that were accessible to pupils and developed their general pedagogical knowledge

Deliberative Democratic Monetary Valuation to implement the Ecosystem Approach

The potential for developing the participatory dimensions of the Ecosystem Approach are examined through the work of Habermas to guide the design of Deliberative Democratic Monetary Valuation (DDMV) and elicit social willingness to pay. DDMV is contrasted with Deliberated Preferences approaches, which are a deliberative adaptation of stated preference techniques and comprise almost all Deliberative Monetary Valuation studies so far. In a detailed case study where coastal and marine cultural ecosystem services were set within a broader societal context, DDMV was undertaken through three iterative workshops involving a single group of participants representing local residents and different interests across the public, private and third sectors. The use of DDMV generates insights into its potential for securing a socially sustainable route to environmental management: sustainable development that brings together values for ecosystem services with other social priorities, is more inclusive of diverse user needs and values, and is sensitive to issues of environmental justice. As well as highlighting the benefits and challenges that a more democratic deliberative valuation presents, we highlight the practical strengths and vulnerabilities of this approach and indicate directions for further methodological evolution of DDMV

Kilonova Luminosity Function Constraints Based on Zwicky Transient Facility Searches for 13 Neutron Star Merger Triggers during O3

We present a systematic search for optical counterparts to 13 gravitational wave (GW) triggers involving at least one neutron star during LIGO/Virgo's third observing run (O3). We searched binary neutron star (BNS) and neutron star black hole (NSBH) merger localizations with the Zwicky Transient Facility (ZTF) and undertook follow-up with the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration. The GW triggers had a median localization area of 4480 deg², a median distance of 267 Mpc, and false-alarm rates ranging from 1.5 to 10⁻²⁵ yr⁻¹. The ZTF coverage in the g and r bands had a median enclosed probability of 39%, median depth of 20.8 mag, and median time lag between merger and the start of observations of 1.5 hr. The O3 follow-up by the GROWTH team comprised 340 UltraViolet/Optical/InfraRed (UVOIR) photometric points, 64 OIR spectra, and three radio images using 17 different telescopes. We find no promising kilonovae (radioactivity-powered counterparts), and we show how to convert the upper limits to constrain the underlying kilonova luminosity function. Initially, we assume that all GW triggers are bona fide astrophysical events regardless of false-alarm rate and that kilonovae accompanying BNS and NSBH mergers are drawn from a common population; later, we relax these assumptions. Assuming that all kilonovae are at least as luminous as the discovery magnitude of GW170817 (−16.1 mag), we calculate that our joint probability of detecting zero kilonovae is only 4.2%. If we assume that all kilonovae are brighter than −16.6 mag (the extrapolated peak magnitude of GW170817) and fade at a rate of 1 mag day⁻¹ (similar to GW170817), the joint probability of zero detections is 7%. If we separate the NSBH and BNS populations based on the online classifications, the joint probability of zero detections, assuming all kilonovae are brighter than −16.6 mag, is 9.7% for NSBH and 7.9% for BNS mergers. Moreover, no more than 10⁻⁴, or φ > 30° to be consistent with our limits. We look forward to searches in the fourth GW observing run; even 17 neutron star mergers with only 50% coverage to a depth of −16 mag would constrain the maximum fraction of bright kilonovae to <25%

Comparing Notes: Recording and Criticism

This chapter charts the ways in which recording has changed the nature of music criticism. It both provides an overview of the history of recording and music criticism, from the advent of Edison’s Phonograph to the present day, and examines the issues arising from this new technology and the consequent transformation of critical thought and practice

Wider Still and Wider: British Music Criticism since the Second World War

This chapter provides the first historical examination of music criticism in Britain since the Second World War. In the process, it also challenges the simplistic prevailing view of this being a period of decline from a golden age in music criticism