The Mediterranean Fruit Fly: Efficient Dynamic and Static Phytosanitary Measures, Information Values, and Current Policy

A bioeconomic model is used to examine efficient dynamic and static phytosanitary policies (cold treatment periods) designed to maximize the annual present value of net monthly U.S. welfare associated with trade in commodities that serve as hosts for the Mediterranean fruit fly (medfly). Accounting for the presence of the current U.S. medfly detection and control program, efficient dynamic and static policies require less cold treatment and increase U.S. welfare 9% and 3%, respectively, relative to the current minimum 14-day treatment period. The potential value of adjusting treatment periods regularly using available information on medfly pressure abroad is shown to be nontrivial.Food Consumption/Nutrition/Food Safety, International Relations/Trade,

Economic Determinants of Invasion and Discovery of Nonindigenous Insects

Introductions of nonindigenous organisms into the United States have been linked to international trade. The individual contributions of imports, immigration, and international travel, however, are poorly understood because introduction dates are unavailable. We examine relationships between economic trends and discoveries of nonindegenous insects and use these relationships to infer the timing and determinants of introductions. We find that a few variables can explain much variation in species introductions and identifications. The most significant contributor to the introduction appears to be agricultural imports. Currently available proxies for academic effort are weak determinants of the probability that introduced species are identified.identifications, insects, introductions, invasive species, nonindegenous, Agribusiness, Crop Production/Industries, F18, N7, Q56,

Establishing a Baseline for Nitrogen Policy Assessment

nitrogen, nitrogen use efficiency, nitrogen management, Environmental Economics and Policy,

Preliminary Assessment of Nitrous Oxide Offsets in a Cap and Trade Program

Nitrous oxide is a powerful greenhouse gas that is emitted from cropland treated with nitrogen fertilizer. Reducing such emissions through nutrient management might be able to produce offsets for sale in a cap and trade program aimed at reducing greenhouse gases. We use the Nitrate Leaching and Economic Analysis Program (NLEAP) model and data from the Agricultural and Resource Management Survey to examine what changes in rate, timing, or method of application a farmer would take to produce offsets. We find that reducing the application rate is the most favored approach for producing offsets. We also find that some management choices may increase nitrate losses to water.nitrous oxide, nutrient management, cap and trade, NLEAP, greenhouse gas, Environmental Economics and Policy,

BT COTTON REFUGE POLICY

Since cotton producers do not own legal rights to kill insect populations that are susceptible to insecticides, individual producers may have no incentive to account for future, insecticide-resistance productivity losses arising from their pest-management decisions. As a result, the collective actions of producers may increase the rate of resistance development relative to the rate that maximizes social welfare. Concerns regarding insect-pest development of resistance to Bt cotton prompted the Environmental Protection Agency to establish legal limits on the proportion of total acres individual producers may plant, representing the first attempt to regulate the development of insecticide resistance and the first instance of the use of refuge as a policy instrument. Ever since Carlson and Castle first pointed out the resource characteristics of insecticide susceptibility, pest management in the presence of increasing resistance has been viewed as an exhaustible resource allocation problem, and many studies have examined efficient insecticide use in this setting. Resistance management studies found in the economics literature, however, have examined single-insect single-insecticide problems almost exclusively. The majority of genetic and entomological studies have followed suit. Since cotton producers routinely use multiple insecticides and insecticide mixtures to manage multiple insect pests, and since simulation and empirical evidence suggests that toxin mixtures can affect the rate of resistance development to component toxins, the standard model may not be well suited for the examination of refuge policies under cotton production settings. Static refuge policies that maximize the present value of profit flows attainable by producers over five- and 10-year planning horizons are examined using a deterministic, operational model that accounts for short- and long-run features of production and resistance development. The model accounts for the development of resistance in two cotton insect pests to Bt cotton and a popular conventional insecticide, and relationships between refuge policy, insecticide resistance, producer profit and producer behavior in Louisiana. The model is used to examine relationships between resistance simulation model parameters and refuge policies and comparative advantages between treated and untreated refuge policies.Agricultural and Food Policy,

The Cost of Increasing Adoption of Beneficial Nutrient-Management Practices

We estimate the cost of offsets tied to reductions in the use of nitrogen on U.S. cornfields under the proposed American Clean Energy and Security Act.offsets, nitrogen, corn, Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy,

Does implementation matter if comprehension is lacking? A qualitative investigation into perceptions of advance care planning in people with cancer

Purpose: While advance care planning holds promise, uptake is variable and it is unclear how well people engage with or comprehend advance care planning. The objective of this study was to explore how people with cancer comprehended Advance Care Plans and examine how accurately advance care planning documentation represented patient wishes. Methods: This study used a qualitative descriptive design. Data collection comprised interviews and an examination of participants’ existing advance care planning documentation. Participants included those who had any diagnosis of cancer with an advance care plan recorded: Refusal of Treatment Certificate; Statement of Choices; and/or Enduring Power of Attorney (Medical Treatment) at one cancer treatment centre. Results: Fourteen participants were involved in the study. Twelve participants were female (86%). The mean age was 77 (range: 61-91) and participants had completed their advance care planning documentation between 8 and 72 weeks prior to the interview (mean 33 weeks). Three themes were evident from the data: Incomplete advance care planning understanding and confidence; Limited congruence for attitude and documentation; Advance care planning can enable peace of mind. Complete advance care planning understanding was unusual; most participants demonstrated partial comprehension of their own advance care plan, and some indicated very limited understanding. Participants’ attitudes and their written document congruence was limited, but advance care planning was seen as helpful. Conclusions: This study highlighted advance care planning was not a completely accurate representation of patient wishes. There is opportunity to improve how patients comprehend their own advance care planning documentation

K2 Discovers a Busy Bee: An Unusual Transiting Neptune Found in the Beehive Cluster

Open clusters have been the focus of several exoplanet surveys but only a few planets have so far been discovered. The \emph{Kepler} spacecraft revealed an abundance of small planets around small, cool stars, therefore, such cluster members are prime targets for exoplanet transit searches. Kepler's new mission, K2, is targeting several open clusters and star-forming regions around the ecliptic to search for transiting planets around their low-mass constituents. Here, we report the discovery of the first transiting planet in the intermediate-age (800 Myr) Beehive cluster (Praesepe). K2-95 is a faint ($\mathrm{Kp = 15.5\,mag}$) $\mathrm{M3.0\pm0.5}$ dwarf from K2's Campaign 5 with an effective temperature of $\mathrm{3471 \pm 124\,K}$, approximately solar metallicity and a radius of $\mathrm{0.402 \pm 0.050 \,R_\odot}$. We detected a transiting planet with a radius of $\mathrm{3.47^{+0.78}_{-0.53} \, R_\oplus}$ and an orbital period of 10.134 days. We combined photometry, medium/high-resolution spectroscopy, adaptive optics/speckle imaging and archival survey images to rule out any false positive detection scenarios, validate the planet, and further characterize the system. The planet's radius is very unusual as M-dwarf field stars rarely have Neptune-sized transiting planets. The comparatively large radius of K2-95b is consistent with the other recently discovered cluster planets K2-25b (Hyades) and K2-33b (Upper Scorpius), indicating systematic differences in their evolutionary states or formation. These discoveries from K2 provide a snapshot of planet formation and evolution in cluster environments and thus make excellent laboratories to test differences between field-star and cluster planet populations.Comment: 14 pages, 8 figues. Accepted for publication in A

Arterial spin labelling reveals an abnormal cerebral perfusion pattern in Parkinson's disease

There is a need for objective imaging markers of Parkinson's disease status and progression. Positron emission tomography and single photon emission computed tomography studies have suggested patterns of abnormal cerebral perfusion in Parkinson's disease as potential functional biomarkers. This study aimed to identify an arterial spin labelling magnetic resonance-derived perfusion network as an accessible, non-invasive alternative. We used pseudo-continuous arterial spin labelling to measure cerebral grey matter perfusion in 61 subjects with Parkinson's disease with a range of motor and cognitive impairment, including patients with dementia and 29 age- and sex-matched controls. Principal component analysis was used to derive a Parkinson's disease-related perfusion network via logistic regression. Region of interest analysis of absolute perfusion values revealed that the Parkinson's disease pattern was characterized by decreased perfusion in posterior parieto-occipital cortex, precuneus and cuneus, and middle frontal gyri compared with healthy controls. Perfusion was preserved in globus pallidus, putamen, anterior cingulate and post- and pre-central gyri. Both motor and cognitive statuses were significant factors related to network score. A network approach, supported by arterial spin labelling-derived absolute perfusion values may provide a readily accessible neuroimaging method to characterize and track progression of both motor and cognitive status in Parkinson's diseas

Three Small Planets Transiting a Hyades Star

We present the discovery of three small planets transiting K2-136 (LP 358 348, EPIC 247589423), a late K dwarf in the Hyades. The planets have orbital periods of $7.9757 \pm 0.0011$, $17.30681^{+0.00034}_{-0.00036}$, and $25.5715^{+0.0038}_{-0.0040}$ days, and radii of $1.05 \pm 0.16$, $3.14 \pm 0.36$, and $1.55^{+0.24}_{-0.21}$ $R_\oplus$, respectively. With an age of 600-800 Myr, these planets are some of the smallest and youngest transiting planets known. Due to the relatively bright (J=9.1) host star, the planets are compelling targets for future characterization via radial velocity mass measurements and transmission spectroscopy. As the first known star with multiple transiting planets in a cluster, the system should be helpful for testing theories of planet formation and migration.Comment: Accepted to The Astronomical Journa