Estimating the Implicit Value of Crop Stubble as a Barrier to Technology Adoption in Morocco

For mixed cereal-livestock farmers, cereal production provides a bundle of goods. Grain is consumed by the household or sold at market, and crop residues are used as livestock feed. The straw component of crop residue can be bought and sold at market and therefore has a well-established local market price. Crop stubble, the portion of the crop residue left on the ground, is generally not traded and therefore has no market price. Some agricultural technologies require farmers to forgo using crop stubble as feed, and cultivation of high value crops entails sacrificing residue production altogether. In this paper we apply a structural econometric model to household data from Morocco to estimate the implicit value of crop stubble. We use a sample splitting technique to investigate differences in the value of this resource and find that it is significantly higher for smaller farmers, who therefore face an even larger barrier to technology adoption.Mixed cereal-livestock systems, Non-market valuation, Land use, Technology adoption, No-till, International Development, Land Economics/Use, Livestock Production/Industries, O33, Q12, Q24,

Quantifying stretching and rearrangement in epithelial sheet migration

Although understanding the collective migration of cells, such as that seen in epithelial sheets, is essential for understanding diseases such as metastatic cancer, this motion is not yet as well characterized as individual cell migration. Here we adapt quantitative metrics used to characterize the flow and deformation of soft matter to contrast different types of motion within a migrating sheet of cells. Using a Finite-Time Lyapunov Exponent (FTLE) analysis, we find that - in spite of large fluctuations - the flow field of an epithelial cell sheet is not chaotic. Stretching of a sheet of cells (i.e., positive FTLE) is localized at the leading edge of migration. By decomposing the motion of the cells into affine and non-affine components using the metric D$^{2}_{min}$, we quantify local plastic rearrangements and describe the motion of a group of cells in a novel way. We find an increase in plastic rearrangements with increasing cell densities, whereas inanimate systems tend to exhibit less non-affine rearrangements with increasing density.Comment: 21 pages, 7 figures This is an author-created, un-copyedited version of an article accepted for publication in the New Journal of Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.1088/1367-2630/15/2/02503

The glacial geomorphology of upper Godthåbsfjord (Nuup Kangerlua) in south-west Greenland

© 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Journal of Maps. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.The Greenland Ice Sheet (GrIS) is known to have experienced widespread retreat over the last century. Information on outlet glacier dynamics, prior to this, are limited due to both a lack of observations and a paucity of mapped or mappable deglacial evidence which restricts our understanding of centennial to millennial timescale dynamics of the GrIS. Here we present glacial geomorphological mapping, for upper Godthåbsfjord, covering 5800 km 2 at a scale of 1:92,000, using a combination of ASTER GDEM V2, a medium-resolution DEM (error < 10 m horizontal and < 6 m vertical accuracy), panchromatic orthophotographs and ground truthing. This work provides a detailed geomorphological assessment for the area, compiled as a single map, comprising of moraines, meltwater channels, streamlined bedrock, sediment lineations, ice-dammed lakes, trimlines, terraces, gullied sediment and marine limits. Whilst some of the landforms have been previously identified, the new information presented here improves our understanding of ice margin behaviour and can be used for future numerical modelling and landform dating programmes. Data also form the basis for palaeoglaciological reconstructions and contribute towards understanding of the centennial to millennial timescale record of this sector of the GrIS.Peer reviewedFinal Published versio

Investigation of Pyrolyzing Ablators Using a Gas Injection Probe

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143112/1/6.2017-0437.pd

Management practices and the quality of care in cardiac units

Importance:- To improve the quality of health care, many researchers have suggested that health care institutions adopt management approaches that have been successful in the manufacturing and technology sectors. However, relatively little information exists about how these practices are disseminated in hospitals and whether they are associated with better performance. Objectives:- To describe the variation in management practices among a large sample of hospital cardiac care units; assess association of these practices with processes of care, readmissions, and mortality for patients with acute myocardial infarction (AMI); and suggest specific directions for the testing and dissemination of health care management approaches. Design:- We adapted an approach used to measure management and organizational practices in manufacturing to collect management data on cardiac units. We scored performance in 18 practices using the following 4 dimensions: standardizing care, tracking of key performance indicators, setting targets, and incentivizing employees. We used multivariate analyses to assess the relationship of management practices with process-of-care measures, 30-day risk-adjusted mortality, and 30-day readmissions for acute myocardial infarction (AMI). Setting:- Cardiac units in US hospitals. Participants_ Five hundred ninety-seven cardiac units, representing 51.5% of hospitals with interventional cardiac catheterization laboratories and at least 25 annual AMI discharges. Main Outcome Measures:- Process-of-care measures, 30-day risk-adjusted mortality, and 30-day readmissions for AMI. Results:- We found a wide distribution in management practices, with fewer than 20% of hospitals scoring a 4 or a 5 (best practice) on more than 9 measures. In multivariate analyses, management practices were significantly correlated with mortality (P = .01) and 6 of 6 process measures (P < .05). No statistically significant association was found between management and 30-day readmissions. Conclusions and Relevance:- The use of management practices adopted from manufacturing sectors is associated with higher process-of-care measures and lower 30-day AMI mortality. Given the wide differences in management practices across hospitals, dissemination of these practices may be beneficial in achieving high-quality outcomes. Interest in quality improvement in health care during the past 10 years has been associated with a handful of important successes.1- 3 However, improvements in the quality of care have been slower than many would have hoped for,4- 8 and quality is still highly variable across organizations.9 Although significant effort has been focused on the use of evidence-based medicine—clinical practices that lead to better care—an interest in organizational strategies and management practices that enable and incentivize high-quality health care is emerging.10- 15 One of the most active areas of interest is in the use of management practices with origins in manufacturing, including, for example, “Lean” methodologies developed at Toyota16 or the use of balanced scorecard approaches that originated in the technology sector.17 These management approaches can be characterized as a set of formalized tools, the use of which is intended to improve quality through multiple pathways, such as eliminating inefficient and variable practices; engaging providers in a collaborative, team-based approach; and structuring mechanisms for setting targets and tracking progress. However, the evidence on the potential effectiveness of these approaches in health care is relatively weak13,18 and consists primarily of single-site studies.19- 21 To address this gap in knowledge, we present a new framework and instrument for defining key management dimensions and for measuring them on a large scale in health care organizations. We describe the variation in management practices among a large sample of hospitals; assess its association with processes of care, readmissions, and mortality for patients with acute myocardial infarction (AMI); and suggest specific directions for the testing and dissemination of health care management approaches

Metropolitan quantum key distribution with silicon photonics

Photonic integrated circuits (PICs) provide a compact and stable platform for quantum photonics. Here we demonstrate a silicon photonics quantum key distribution (QKD) transmitter in the first high-speed polarization-based QKD field tests. The systems reach composable secret key rates of 950 kbps in a local test (on a 103.6-m fiber with a total emulated loss of 9.2 dB) and 106 kbps in an intercity metropolitan test (on a 43-km fiber with 16.4 dB loss). Our results represent the highest secret key generation rate for polarization-based QKD experiments at a standard telecom wavelength and demonstrate PICs as a promising, scalable resource for future formation of metropolitan quantum-secure communications networks

A Novel Vertebrate Eye Using Both Refractive and Reflective Optics

SummarySunlight is attenuated rapidly in the ocean, resulting in little visually useful light reaching deeper than ∼1000 m in even the clearest water [1]. To maximize sensitivity to the relatively brighter downwelling sunlight, to view the silhouette of animals above them, and to increase the binocular overlap of their eyes, many mesopelagic animals have developed upward-pointing tubular eyes [2–4]. However, these sacrifice the ability to detect bioluminescent [5] and reflective objects in other directions. Thus, some mesopelagic fish with tubular eyes extend their visual fields laterally and/or ventrally by lensless ocular diverticula, which are thought to provide unfocused images, allowing only simple detection of objects, with little spatial resolution [2–4]. Here, we show that a medial mirror within the ventrally facing ocular diverticulum of the spookfish, Dolichopteryx longipes, consisting of a multilayer stack derived from a retinal tapetum, is used to reflect light onto a lateral retina. The reflective plates are not orientated parallel to the surface of the mirror. Instead, plate angles change progressively around the mirror, and computer modeling indicates that this provides a well-focused image. This is the first report of an ocular image being formed in a vertebrate eye by a mirror

The Ursinus Weekly, October 28, 1940

Senator J. A. Ellender holds Willkie temperamentally unfit for president • Importance of \u27but\u27 told by vespers talk • Connor calls news staff to plan for Jr. paper • Republican rally to hear Davis tomorrow evening • Rev. Mr. Faye \u2724, to speak on problems of college students • Prof. Mauchly gives lecture at conference of physicists • Hoosier prophet ventures vote prognostication • Get a mask for Friday! • Results of Berlin-Tokyo axis discussed in IRC panel talks • Meistersingers to sing at Collegeville-Trappe assembly • Minutes before, Huey and I were talking... • Campaigning with Yehudi! • Mules\u27 offensive attack swamps bears by 15-6 • Allison leads \u27Fords against bakermen, 3-0 • Rootin\u27 tootin\u27 bout slated, Nov. 5, Sam\u27s arena • Ursinus hockeyites blank Rosemont • Baker is optimistic on soccer future • English Club admits seven; discusses books for review • Joyce Ward reports plans of women\u27s archery practice • \u27Big sisters\u27 treat freshmen and co-ed transfers at movie • Pre-legals fingerprinted; hear of scientific detectionhttps://digitalcommons.ursinus.edu/weekly/1796/thumbnail.jp

The Factory and the Beehive III: PTFEB132.707+19.810, a Low-Mass Eclipsing Binary in Praesepe Observed by PTF and K2

Theoretical models of stars constitute a fundamental bedrock upon which much of astrophysics is built, but large swaths of model parameter space remain uncalibrated by observations. The best calibrators are eclipsing binaries in clusters, allowing measurement of masses, radii, luminosities, and temperatures, for stars of known metallicity and age. We present the discovery and detailed characterization of PTFEB132.707+19.810, a P=6.0 day eclipsing binary in the Praesepe cluster ($\tau$~600--800 Myr; [Fe/H]=0.14$\pm$0.04). The system contains two late-type stars (SpT$_P$=M3.5$\pm$0.2; SpT$_S$=M4.3$\pm$0.7) with precise masses ($M_p=0.3953\pm0.0020$~$M_{\odot}$; $M_s=0.2098\pm0.0014$~$M_{\odot}$) and radii ($R_p=0.363\pm0.008$~$R_{\odot}$; $R_s=0.272\pm0.012$~$R_{\odot}$). Neither star meets the predictions of stellar evolutionary models. The primary has the expected radius, but is cooler and less luminous, while the secondary has the expected luminosity, but is cooler and substantially larger (by 20%). The system is not tidally locked or circularized. Exploiting a fortuitous 4:5 commensurability between $P_{orb}$ and $P_{rot,prim}$, we demonstrate that fitting errors from the unknown spot configuration only change the inferred radii by <1--2%. We also analyze subsets of data to test the robustness of radius measurements; the radius sum is more robust to systematic errors and preferable for model comparisons. We also test plausible changes in limb darkening, and find corresponding uncertainties of ~1%. Finally, we validate our pipeline using extant data for GU Boo, finding that our independent results match previous radii to within the mutual uncertainties (2--3%). We therefore suggest that the substantial discrepancies are astrophysical; since they are larger than for old field stars, they may be tied to the intermediate age of PTFEB132.707+19.810.Comment: Accepted to ApJ; 36 pages, 19 figures, 8 tables in two-column AASTEX6 forma