MODELING SPATIAL DEPENDENCE AND SPATIAL HETEROGENEITY IN COUNTY YIELD FORECASTING MODELS

The implications of ignoring potential spatial dependence in county-level yield data are discussed. Spatial dependence in a county-level yield data set is identified and methods for correcting the dependence via spatial weighting matrices and generalized least squares regression are performed. The paper also examines how the spatial dependence declines as the distance between observations increases.Productivity Analysis, Research Methods/ Statistical Methods,

Discordance between cosmogenic nuclide concentrations in amalgamated sands and individual fluvial pebbles in an arid zone catchment

Based on cosmogenic 10Be and 26Al analyses in 15 individual detrital quartz pebbles (16–21 mm) and cosmogenic 10Be in amalgamated medium sand (0.25–0.50 mm), all collected from the outlet of the upper Gaub River catchment in Namibia, quartz pebbles yield a substantially lower average denudation rate than those yielded by the amalgamated sand sample. 10Be and 26Al concentrations in the 15 individual pebbles span nearly two orders of magnitude (0.22 ± 0.01 to 20.74 ± 0.52 × 10610Be atoms g−1 and 1.35 ± 0.09 to 72.76 ± 2.04 × 10626Al atoms g−1, respectively) and yield average denudation rates of ∼0.7 m Myr−1 (10Be) and ∼0.9 m Myr−1 (26Al). In contrast, the amalgamated sand yields an average 10Be concentration of 0.77 ± 0.03 × 106 atoms g−1, and an associated mean denudation rate of 9.6 ± 1.1 m Myr−1, an order of magnitude greater than the rates obtained for the amalgamated pebbles. The inconsistency between the 10Be and 26Al in the pebbles and the 10Be in the amalgamated sand is likely due to the combined effect of differential sediment sourcing and longer sediment transport times for the pebbles compared to the sand-sized grains. The amalgamated sands leaving the catchment are an aggregate of grains originating from all quartz-bearing rocks in all parts of the catchment. Thus, the cosmogenic nuclide inventories of these sands record the overall average lowering rate of the landscape. The pebbles originate from quartz vein outcrops throughout the catchment, and the episodic erosion of the latter means that the pebbles will have higher nuclide inventories than the surrounding bedrock and soil, and therefore also higher than the amalgamated sand grains. The order-of-magnitude grain size bias observed in the Gaub has important implications for using cosmogenic nuclide abundances in depositional surfaces because in arid environments, akin to our study catchment, pebble-sized clasts yield substantially underestimated palaeo-denudation rates. Our results highlight the importance of carefully considering geomorphology and grain size when interpreting cosmogenic nuclide data in depositional surfaces

Testing the Attractiveness and Efficacy of Baits for the Monitoring and Control of the Thief Ant, Solenopsis papuana

Solenopsis papuana is one of the few introduced ant species that have widely infiltrated undisturbed mesic and wet forests in Hawaii. This may be problematic since many endemic Hawaiian insects are limited to mountain forests, and methods for monitoring and controlling S. papuana would be useful. Four non-toxic monitoring baits (corn syrup, SPAM®, peanut butter, and tuna/ corn syrup blend) and five ant pesticide baits (Advion® Fire Ant BaitTM, Amdro® Ant Block®, ExtinguishTM Plus, MaxForce® Complete Brand Granular Insect Bait, and SiestaTM) were tested for attractiveness to S. papuana in choice tests at Lyon Arboretum and Pahole Natural Area Reserve (NAR) on the island of Oahu. Amdro® Ant Block® and SiestaTM were also tested for efficacy against S. papuana in field plots at Pahole NAR. SPAM® and peanut butter were the most attractive monitoring baits at both locations. There were few significant differences in at- tractiveness among the five ant pesticides, but Amdro® Ant Block® attracted the highest or second highest number of ants at both sites, while rankings among the other baits were inconsistent. Amdro® Ant Block® presented in bait stations 2.5 m apart greatly reduced the number of ants at monitoring cards in field plots, by an average of 96% from pre-treatment levels over the course of the 246-day trial. Ant numbers also declined in the SiestaTM plots (by 77%), but more closely mir- rored fluctuations in the untreated control plots. These methods were effective for monitoring and suppressing S. papuana populations in localized natural areas in the Waianae Mountain Range

The prose poem as Igel: a reading of fragmentation and closure in prose poetry

This paper takes up Nikki Santilli’s lament about the scarcity of scholarship on the prose poem in English to analyse two key features of prose poetry: fragmentation and closure. This paper argues that the prose poem’s visual containment within the paragraph form promises a complete narrative while simultaneously subverting this visual cue by offering, instead, gaps and spaces. Such apertures render the prose poem a largely fragmentary form that relies on metonymic metamorphoses to connect to a larger, unnamed frame of reference. In this way, the prose poem is both complete and yet searching for completeness, closed and lacking closure.The prose poem’s reaching outwards to embrace a larger, absent whole connects this literary form to Friedrich Schlegel’s ‘Athenaeum Fragment 206’ and to the Romantic critical fragment more generally. ‘Athenaeum Fragment 206’ has provided this paper with its title, as a metaphorical reading of Schlegel’s igel, or hedgehog, as fragment ‘implies the existence of [a form that suggests] what is outside itself’ (Rosen 1995: 48). The final section of this paper, analyses two prose poems from the University of Canberra’s International Poetry Studies Institute’s Prose Poetry Project. These works by Jen Webb and Carrie Etter are read for their appeal to metonymy in their exploration of time passing and ultimately, death. They demonstrate that prose poetry is both fragmented and open ended in ways very different from lineated poems

Peripheral visual cues contribute to the perception of object movement during self-movement

Safe movement through the environment requires us to monitor our surroundings for moving objects or people. However, identification of moving objects in the scene is complicated by self-movement, which adds motion across the retina. To identify worldrelative object movement the brain thus has to “compensate for” or “parse out” the components of retinal motion that are due to self-movement. We have previously demonstrated that retinal cues arising from central vision contribute to solving this problem. Here we investigate the contribution of peripheral vision, commonly thought to provide strong cues to self-movement. Stationary participants viewed a large field of view display, with radial flow patterns presented in the periphery, and judged the trajectory of a centrally presented probe. Across two experiments, we demonstrate andquantify the contribution of peripheral optic flow to flow parsing during forward and backward movement

Nitrogen-Linked Diphosphine Ligands with Ethers Attached to Nitrogen for Chromium-Catalyzed Ethylene Tri- and Tetramerizations

A series of bis(diphenylphosphino)amine ligands with a donor group attached to the nitrogen linker have been prepared. Metalation of these ligands with chromium trichloride provides precursors to highly active, relatively stable, and selective catalysts for trimerization and tetramerization of ethylene. It has been demonstrated in oligomerization reactions performed at 1 and 4 atm of ethylene that these new systems increase total productivity by enhancing catalyst stability, as compared with those lacking a donor group on the diphosphine ligand. Furthermore, the use of chlorobenzene solvent (rather than toluene) significantly improves productivity, stability, and selectitvity. The product distributions and minor byproducts provide information relevant to mechanistic issues surrounding these types of reactions

COMPETITIVE GRANTS AND THE FUNDING OF AGRICULTURAL RESEARCH IN THE U.S.

To increase the efficiency of the public agricultural R&D system, expanded use of competitive grants to fund state institutions has been advocated. This paper characterizes different funding instruments and empirically assesses the effects of changes in mechanism use. Factors associated with greater levels of competitive grants are modeled.Research and Development/Tech Change/Emerging Technologies,

Sixteen years of Collaborative Learning through Active Sense-making in Physics (CLASP) at UC Davis

This paper describes our large reformed introductory physics course at UC Davis, which bioscience students have been taking since 1996. The central feature of this course is a focus on sense-making by the students during the five hours per week discussion/labs in which the students take part in activities emphasizing peer-peer discussions, argumentation, and presentations of ideas. The course differs in many fundamental ways from traditionally taught introductory physics courses. After discussing the unique features of CLASP and its implementation at UC Davis, various student outcome measures are presented showing increased performance by students who took the CLASP course compared to students who took a traditionally taught introductory physics course. Measures we use include upper-division GPAs, MCAT scores, FCI gains, and MPEX-II scores.Comment: Also submitted to American Journal of Physic