501 research outputs found

    Restaurant Revenue Management: Applying Yield Management to the Restaurant Industry

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    The crucial element in a strategy for boosting restaurant revenues may be to relate prices to the length of time guests spend at the table. But, as the Witch of the West told Dorothy, the issue is how to do it

    Surrogate light curve models for kilonovae with comprehensive wind ejecta outflows and parameter estimation for AT2017gfo

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    The electromagnetic emission resulting from neutron star mergers have been shown to encode properties of the ejected material in their light curves. The ejecta properties inferred from the kilonova emission has been in tension with those calculated based on the gravitational wave signal and numerical relativity models. Motivated by this tension, we construct a broad set of surrogate light curve models derived for kilonova ejecta. The four-parameter family of two-dimensional anisotropic simulations and its associated surrogate explore different assumptions about the wind outflow morphology and outflow composition, keeping the dynamical ejecta component consistent. We present the capabilities of these surrogate models in interpolating kilonova light curves across various ejecta parameters and perform parameter estimation for AT2017gfo both without any assumptions on the outflow and under the assumption that the outflow must be representative of solar r-process abundance patterns. Our parameter estimation for AT2017gfo shows these surrogate models help alleviate the ejecta property discrepancy while also illustrating the impact of systematic modeling uncertainties on these properties, urging further investigation.Comment: 15 pages, 6 figures, data available in Zenodo (https://zenodo.org/record/7335961) and GitHub (https://github.com/markoris/surrogate_kne

    You Can Quit Me But I’m Not Going to Quit You:” A Focus Group Study of Leaders’ Perceptions of Their Positive Influences on Youth in Boy Scouts of America

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    As part of a longitudinal, mixed-method study with Boy Scouts of America, we conducted five focus groups with a diverse group of 46 program leaders in order to better understand their perceptions of how they influence youth. Drawing from grounded theory analysis methods, we found that leaders believed they promoted positive youth outcomes, including character and self-confidence, through caring youth-leader relationships and facilitating opportunities for youth to participate in and lead skill-building activities and apply skills in different contexts. Leaders differed in the particular outcomes that they emphasized. Implications of these findings for future research and practice are discussed

    Ursinus College Alumni Journal, November 1961

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    The president\u27s wife writes • Mater Ursini • The Ursinus College European tour • Admiral Moreell looks at a philosopher • Zucker looks at Moreell • A woman\u27s approach to peace • Founders\u27 Day • 1962 Forum programs • Cutting campus • From Alaska to Greenland • Faith and freedom in Taiwan • Reginald Helfferich honored • Poet King • Henry P. Laughlin, \u2738 • Robert Pease, \u2733 • Ursinus student at White House conference • Harleston R. Wood • Football • Soccer • Hockey • Basketball • Wrestling • 53.5% contribute to Loyalty Fund in 1961 • Progress report 1962 campaign • 1961 campaign results • The Century Club • Loyalty Fund all-stars • Loyalty Fund kick-off dinner • Matching gifts • Results of the 1961 Loyalty Fund campaign • Contributors to the 1961 Loyalty Fund campaign • Class notes • Weddings • Births • Necrology • Sing along with us • New faculty membershttps://digitalcommons.ursinus.edu/alumnijournal/1072/thumbnail.jp

    Droplet Size Impact on Efficacy of a Dicamba-plus-Glyphosate Mixture

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    Chemical weed control remains a widely used component of integrated weed management strategies because of its cost-effectiveness and rapid removal of crop pests. Additionally, dicamba-plus-glyphosate mixtures are a commonly recommended herbicide combination to combat herbicide resistance, specifically in recently commercially released dicamba-tolerant soybean and cotton. However, increased spray drift concerns and antagonistic interactions require that the application process be optimized to maximize biological efficacy while minimizing environmental contamination potential. Field research was conducted in 2016, 2017, and 2018 across three locations (Mississippi, Nebraska, and North Dakota) for a total of six site-years. The objectives were to characterize the efficacy of a range of droplet sizes [150 μm (Fine) to 900 μm (Ultra Coarse)] using a dicamba-plus-glyphosate mixture and to create novel weed management recommendations utilizing pulse-width modulation (PWM) sprayer technology. Results across pooled site-years indicated that a droplet size of 395 μm (Coarse) maximized weed mortality from a dicamba-plus-glyphosate mixture at 94 L ha–1. However, droplet size could be increased to 620 μm (Extremely Coarse) to maintain 90% of the maximum weed mortality while further mitigating particle drift potential. Although generalized droplet size recommendations could be created across site-years, optimum droplet sizes within each site-year varied considerably and may be dependent on weed species, geographic location, weather conditions, and herbicide resistance(s) present in the field. The precise, site-specific application of a dicamba-plus-glyphosate mixture using the results of this research will allow applicators to more effectively utilize PWM sprayers, reduce particle drift potential, maintain biological efficacy, and reduce the selection pressure for the evolution of herbicide-resistant weeds

    A Halomethane thermochemical network from iPEPICO experiments and quantum chemical calculations

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    Internal energy selected halomethane cations CH3Cl+, CH2Cl2+, CHCl3+, CH3F+, CH2F2+, CHClF2+ and CBrClF2+ were prepared by vacuum ultraviolet photoionization, and their lowest energy dissociation channel studied using imaging photoelectron photoion coincidence spectroscopy (iPEPICO). This channel involves hydrogen atom loss for CH3F+, CH2F2+ and CH3Cl+, chlorine atom loss for CH2Cl2+, CHCl3+ and CHClF2+, and bromine atom loss for CBrClF2+. Accurate 0 K appearance energies, in conjunction with ab initio isodesmic and halogen exchange reaction energies, establish a thermochemical network, which is optimized to update and confirm the enthalpies of formation of the sample molecules and their dissociative photoionization products. The ground electronic states of CHCl3+, CHClF2+ and CBrClF2+ do not confirm to the deep well assumption, and the experimental breakdown curve deviates from the deep well model at low energies. Breakdown curve analysis of such shallow well systems supplies a satisfactorily succinct route to the adiabatic ionization energy of the parent molecule, particularly if the threshold photoelectron spectrum is not resolved and a purely computational route is unfeasible. The ionization energies have been found to be 11.47 ± 0.01 eV, 12.30 ± 0.02 eV and 11.23 ± 0.03 eV for CHCl3, CHClF2 and CBrClF2, respectively. The updated 0 K enthalpies of formation, ∆fHo0K(g) for the ions CH2F+, CHF2+, CHCl2+, CCl3+, CCl2F+ and CClF2+ have been derived to be 844.4 ± 2.1, 601.6 ± 2.7, 890.3 ± 2.2, 849.8 ± 3.2, 701.2 ± 3.3 and 552.2 ± 3.4 kJ mol–1, respectively. The ∆fHo0K(g) values for the neutrals CCl4, CBrClF2, CClF3, CCl2F2 and CCl3F and have been determined to be –94.0 ± 3.2, –446.6 ± 2.7, –702.1 ± 3.5, –487.8 ± 3.4 and –285.2 ± 3.2 kJ mol–1, respectively

    Dry weather induces outbreaks of human West Nile virus infections

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    <p>Abstract</p> <p>Background</p> <p>Since its first occurrence in the New York City area during 1999, West Nile virus (WNV) has spread rapidly across North America and has become a major public health concern in North America. By 2002, WNV was reported in 40 states and the District of Columbia with 4,156 human and 14,539 equine cases of infection. Mississippi had the highest human incidence rate of WNV during the 2002 epidemic in the United States. Epidemics of WNV can impose enormous impacts on local economies. Therefore, it is advantageous to predict human WNV risks for cost-effective controls of the disease and optimal allocations of limited resources. Understanding relationships between precipitation and WNV transmission is crucial for predicting the risk of the human WNV disease outbreaks under predicted global climate change scenarios.</p> <p>Methods</p> <p>We analyzed data on the human WNV incidences in the 82 counties of Mississippi in 2002, using standard morbidity ratio (SMR) and Bayesian hierarchical models, to determine relationships between precipitation and human WNV risks. We also entertained spatial autocorrelations of human WNV risks with conditional autocorrelative (CAR) models, implemented in WinBUGS 1.4.3.</p> <p>Results</p> <p>We observed an inverse relationship between county-level human WNV incidence risk and total annual rainfall during the previous year. Parameters representing spatial heterogeneity in the risk of human exposure to WNV improved model fit. Annual precipitation of the previous year was a predictor of spatial variation of WNV risk.</p> <p>Conclusions</p> <p>Our results have broad implications for risk assessment of WNV and forecasting WNV outbreaks. Assessing risk of vector-born infectious diseases will require understanding of complex ecological relationships. Based on the climatologically characteristic drought occurrence in the past and on climate model predictions for climate change and potentially greater drought occurrence in the future, we suggest that the frequency and relative risk of WNV outbreaks could increase.</p

    Program Innovations and Character in Cub Scouts: Findings from Year 1 of a Mixed-Methods, Longitudinal Study

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    Youth development programs seek to promote positive development through mentoring and engaging youth in opportunities for individual growth and community connectedness. We present findings from the initial phase of a mixed-methods, longitudinal study aimed at assessing the impact of one such program, Cub Scouts, on character development. We assessed if Scouting, and a recent innovation in Scouting focused on program quality, are associated with the development of character and other positive youth outcomes. Participants were 1,083 Scouts and non-Scouts, aged 5-12 years. At the start of the study, there was no difference in indicators of character between Scouts and non-Scouts, once matched through propensity score analyses. Through content analyses of interviews and short- answer questionnaires administered to leaders, we found that leaders’ views of character and of their roles corresponded to those envisioned by Cub Scouts. Implications for character development, and for the role of program components in character development, are discussed
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