Annual bluegrass is a troublesome weed in turfgrass, with reported resistance to at least 12 herbicide sites of action. The mitotic-inhibiting herbicide pronamide has both preemergence and postemergence activity on susceptible annual bluegrass populations. Previous studies suggest that postemergence activity may be compromised due to lack of root uptake, as well as target-site- and translocation-based mechanisms. Research was conducted to determine the effects of spray droplet spectra on spray coverage and control of annual bluegrass with pronamide, flazasulfuron, and a mixture of pronamide plus flazasulfuron. Herbicides were delivered to annual bluegrass plants having two to three leaves via five different spray spectra based on volume median diameters (VMD) of 200, 400, 600, 800, and 1,000 µm. Fluorescent tracer dye was added to each treatment solution to quantify the effects of herbicide and spray droplet spectra on herbicide deposition. In another experiment, the efficacy of 0.58, 1.16, and 2.32 kg pronamide ha−1; 0.022, 0.044, and 0.088 kg flazasulfuron ha−1, or a combination of the two, were assessed in iteration with droplet spectrum sprays of 400 and 1,000 µm on two pronamide-resistant and two pronamide-susceptible annual bluegrass populations. Spray droplet spectrum affected the deposition of pronamide and flazasulfuron, applied alone and in combination. Pronamide foliar deposition decreased with increasing droplet spectra. Pronamide efficacy was affected by droplet spectrum, with the largest (1,000 µm) exhibiting improved control. Flazasulfuron efficacy and pronamide plus flazasulfuron efficacy were not affected by droplet spectra. Pronamide plus flazasulfuron mixture controlled all four populations more effectively than pronamide alone, regardless of droplet spectra. A mixture of pronamide plus flazasulfuron applied with relatively large droplets may be optimal for annual bluegrass control, which offers valuable insights for optimizing herbicide application and combatting herbicide resistance. However, applications in this controlled-growth pot study may not mimic conditions in which thatch and turfgrass canopy limit the soil deposition of pronamide.

Consider a Brownian motion on the circumference of the unit circle, which jumps to the opposite point of the circumference at incident times of an independent Poisson process of rate $\lambda$. We examine the problem of coupling two copies of this ‘jumpy Brownian motion’ started from different locations, so as to optimise certain functions of the coupling time. We describe two intuitive co-adapted couplings (‘Mirror’ and ‘Synchronous’) which differ only when the two processes are directly opposite one another, and show that the question of which strategy is best depends upon the jump rate $\lambda$ in a non-trivial way. We also provide an explicit description of a (non-co-adapted) maximal coupling for any jump rate in the case that the two jumpy Brownian motions begin at antipodal points of the circle.

Crop residue can intercept and adsorb residual herbicides, leading to reduced efficacy. However, adsorption can sometimes be reversed by rainfall or irrigation. Greenhouse experiments were conducted to evaluate the effect of differential overhead irrigation level on barnyardgrass response to acetochlor, pyroxasulfone, and pendimethalin applied to bare soil or wheat straw–covered soil. Acetochlor applied to wheat straw–covered soil resulted in 25% to 40% reduced control, 30 to 50 more plants 213 cm−2, and greater biomass than bare soil applications, regardless of irrigation amount. Barnyardgrass suppression by pyroxasulfone applications to wheat straw–covered soil improved with increased irrigation; however, weed control levels similar to bare soil applications were not observed after any irrigation amount. Barnyardgrass densities from pyroxasulfone applications to bare soil decreased with irrigation but did not change in applications to wheat straw–covered soil. Aboveground barnyardgrass biomass from pyroxasulfone decreased with greater irrigation amounts in both bare soil and wheat straw–covered soil applications; however, decreased efficacy in wheat straw–covered soil applications was not alleviated with irrigation. Pendimethalin was the only herbicide tested that displayed reduced efficacy when irrigation amounts increased in applications to both bare soil and wheat straw–covered soil. Barnyardgrass control from pendimethalin applied to wheat straw–covered soil was similar to bare soil applications when approximately 0.3 to 1.2 cm of irrigation was applied; however, irrigation amounts greater than 1.2 cm resulted in greater barnyardgrass control in bare soil applications. No differences between wheat straw–covered soil and bare soil applications of pendimethalin were observed for barnyardgrass densities. These data indicate that increased irrigation or rainfall level can increase efficacy of acetochlor and pyroxasulfone. Optimal rainfall or irrigation amounts required for efficacy similar to bare soil applications are herbicide specific, and some herbicides, such as pendimethalin, may be adversely affected by increased rainfall or irrigation.

Guided by principles from life-history theory, theories of adaptive calibration provide an overarching theoretical framework for understanding the developmental roots of impulsivity and externalizing psychopathology. The current research provides evidence for robust associations between perceptions of childhood unpredictability, delay discounting (Studies 1a and 1b), and adult externalizing traits and behaviors (Study 2). Both associations were observed while controlling for perceptions of the harshness of childhood environments, as well as a range of demographic characteristics. The association with externalizing traits and behavior was observed over and above current mood and depressive symptoms. Study 2 also replicated a previously documented association between changes in maternal employment, residence, and cohabitation during childhood and externalizing behavior and, furthermore, suggested that this association was mediated by perceptions of unpredictability. These studies provided no evidence for links between perceived childhood unpredictability and basic forms of risk-taking (Studies 1a and 1c). This research adds to a growing body of work leveraging principles from life-history theory to demonstrate links between childhood experiences, impulsivity, and potentially debilitating forms of mental illness. This work also highlights the value of assessing people’s perceptions of their childhood environments.

Community-supported agriculture (CSA) is an alternative food marketing model in which community members subscribe to receive regular shares of a farm's harvest. Although CSA has the potential to improve access to fresh produce, certain features of CSA membership may prohibit low-income families from participating. A ‘cost-offset’ CSA (CO-CSA) model provides low-income families with purchasing support with the goal of making CSA more affordable. As a first step toward understanding the potential of CO-CSA to improve access to healthy foods among low-income households, we interviewed 24 CSA farmers and 20 full-pay CSA members about their experiences and perceptions of the cost-offset model and specific mechanisms for offsetting the cost of CSA. Audio recordings were transcribed verbatim and coded using a thematic approach. Ensuring that healthy food was accessible to everyone, regardless of income level, was a major theme expressed by both farmers and members. In general, CSA farmers and CSA members favored member donations over other mechanisms for funding the CO-CSA. The potential time burden that could affect CSA farmers when administering a cost-offset was a commonly-mentioned barrier. Future research should investigate various CO-CSA operational models in order to determine which models are most economically viable and sustainable.

The Square Kilometre Array (SKA) is a planned large radio interferometer designed to operate over a wide range of frequencies, and with an order of magnitude greater sensitivity and survey speed than any current radio telescope. The SKA will address many important topics in astronomy, ranging from planet formation to distant galaxies. However, in this work, we consider the perspective of the SKA as a facility for studying physics. We review four areas in which the SKA is expected to make major contributions to our understanding of fundamental physics: cosmic dawn and reionisation; gravity and gravitational radiation; cosmology and dark energy; and dark matter and astroparticle physics. These discussions demonstrate that the SKA will be a spectacular physics machine, which will provide many new breakthroughs and novel insights on matter, energy, and spacetime.

How did personal wealth and slaveownership affect the likelihood Southerners fought for the Confederate Army in the American Civil War? On the one hand, wealthy Southerners had incentives to free-ride on poorer Southerners and avoid fighting; on the other hand, wealthy Southerners were disproportionately slaveowners, and thus had more at stake in the outcome of the war. We assemble a dataset on roughly 3.9 million free citizens in the Confederacy and show that slaveowners were more likely to fight than non-slaveowners. We then exploit a randomized land lottery held in 1832 in Georgia. Households of lottery winners owned more slaves in 1850 and were more likely to have sons who fought in the Confederate Army. We conclude that slaveownership, in contrast to some other kinds of wealth, compelled Southerners to fight despite free-rider incentives because it raised their stakes in the war’s outcome.

A commercially available combined X-ray diffraction – differential scanning calorimetry (XRD-DSC) stage was adapted for studies of gas loading in microporous materials, including metal organic frameworks (MOFs). Insertion of a custom-built humid atmosphere swing chamber (HASC) between a humidity generator and the XRD-DSC stage facilitates both humid atmosphere and vacuum swing gas loading. The HASC is necessary to buffer between the humidity generator and the XRD-DSC stage, allowing the gas mixture to homogenize prior to sample exposure, so that both humid atmosphere and vacuum swings could be performed. The changes in XRD can be used to follow structural changes, including collapse, which is indicative of a lack of microporosity upon activation, and the flexibity of frameworks upon gas sorption–desorption cycles. Measurements of the area under the DSC curve allows for calculation of the isosteric heat of adsorption (Qst; kJ molGAS−1). Vacuum-atmosphere swing experiments performed at different pressure steps allow for the reconstruction of the enthalpy of gas adsorption before and after a phase transition. These modes of operation are illustrated in three case studies from a program of exploratory MOF synthesis used to discover novel materials for selective gas sorption from humid gas streams: (1) gas binding in Stony Brook metal organic framework-1, (2) zeolitic imidazolate framework-7 response to variable pressure vacuum-atmosphere swing, and (3) high throughput evaluation of the selectivity of novel MOFs synthesized from customized linkers.

Introduction: Recent reports suggest that up to 30% of medical interventions provide no benefit to patients. In a response to ED over-crowding, guidelines commonly exist to guide blood test ordering in patients waiting to see a physician. In many cases, this increases the use of tests without benefiting patients. We describe a quality improvement project designed to reduce the number of laboratory tests considered routine for waiting patients. Methods: A multidisciplinary group reviewed existing symptom-prompted nursing blood test guidelines for serum electrolytes and glucose, renal function tests, liver tests, lipase, toxicological tests and beta Human Chorionic gonadotrophin levels. Order sets were revised with tests eliminated from the routine panels that were not felt to routinely contribute to patient care. The new guidelines were communicated to nursing staff in a series of educational sessions, and the revised guidelines were posted at nursing stations. Physician ordering practice was not changed. A pre-post evaluation compared the period 1 December 2014, - 30 November 2015 with 1 December 2015 - 30 November 2016. Clinical outcomes and patient wait times were not evaluated. Results: The use of tests in these categories decreased 32% between the two periods, at a net saving of $210, 246c. The largest savings came from total protein (73% decrease), Creatine kinase (68%), chloride (64%), glucose (49%), and albumin (47%). Sodium/Potassium testing decreased by only 13%. The only increase in test ordering recorded was AST (3% increase). Conclusion: Simply changing symptom driven order sets resulted in significant savings to the system. In the era of Choosing wisely regular review of lab order sets is indicated. Further study is needed to assess the effect of these changes on patient flow and on clinical outcome.

Prescribed burning and the herbicide clopyralid are very effective tools for the management of yellow starthistle. However, repeated use of either can be impractical or can present other problems. The potential solution is the development of an effective integrated weed management strategy using a combination of the two approaches. In small plot studies (0.2 ha), we tested one of five possible treatments: (1) untreated control, (2) 2 consecutive yr of clopyralid (0.105 kg ha−1), (3) 2 consecutive yr of prescribed summer burning, (4) first-year clopyralid followed by second-year prescribed burning, and (5) first-year prescribed burning followed by second-year clopyralid. Treatments were made in 1999 and 2000 at three study sites in California (San Benito, Yuba, and Siskiyou counties). In 2001, the year following the final treatment, 2 consecutive yr of clopyralid or first-year burning followed by second-year clopyralid consistently reduced yellow starthistle cover in the following year by 92 to 100%. However, at the Yuba site, clopyralid alone increased medusahead and ripgut brome cover. Although 2 consecutive yr of burning was effective in Yuba, very high levels of starthistle infestation in San Benito were not completely burned in the second year because of the lack of available consumable fuel. Clopyralid treatment the first year followed by prescribed burning in the second year stimulated yellow starthistle germination and did not reduce the infestation. In a large-scale study conducted at two sites (13 and 81 ha) in southern Monterey County, we used a first-year burn followed by either 2 yr of clopyralid (0.158 kg ha−1) or a single year of clopyralid (0.210 kg ha−1) and a subsequent burn. Results were in close agreement with those found in the small-scale studies. In the year following the final treatment, control of yellow starthistle was greater than 99% when the burn was followed by 2 yr of clopyralid. In contrast, when a prescribed burn was used in the last year of the program, the level of control was not as good, probably because of the increased germination of the remaining soil seedbank. These results indicate that a first-year prescribed burn followed by a second-year clopyralid treatment can provide consistently good control of yellow starthistle, as well as reduced levels of noxious annual grasses, including medusahead and ripgut brome.