Teaching Business Statistics: Some Useful Relationships

The purpose of this paper is to suggest an instructional approach in the introductory business statistics course that utilizes relationships between separately introduced topics. The paper will explore three “useful relationships” that can assist classroom instruction: (1) the relationship between the simple arithmetic mean, the weighted arithmetic mean, and the expected value of a discrete probability distribution; (2) the relationship between the use of the multiplication rule to calculate the joint probability associated with two events, use of tree diagrams, and the use of the binomial and hypergeometric distributions; and (3) the relationship between the geometric mean and the compound interest rate. Each discussion includes detailed examples of calculations to demonstrate the relationships

COLONIZATION OF NORTHERN LOUISIANA BY THE MEDITERRANEAN GECKO, HEMIDACTYLUS TURCICUS

The Mediterranean Gecko, Hemidactylus turcicus, is known to have colonized nearly every state in the southern United States. In Louisiana, the Mediterranean Gecko has been documented in many of the southern parishes, but records for the northern portion of the state are limited. We sampled northern Louisiana parishes to document the presence of the Mediterranean Gecko. We sampled a total of 21 parishes in northern Louisiana and found geckos in 17 of those parishes, 16 of which represent new distribution records for the species. This indicates a significant range expansion of this introduced species throughout northern Louisiana. Geckos were found across a temperature range of 14.0–28.0°C and had a strong association with buildings. The species’ affinity for anthropogenic association and the continual nature of anthropogenic expansion facilitate the high vagility of this species. The result is a successful colonization throughout much of Louisiana and likely continued range expansion throughout the southern United States

An Employment-Weighted Municipal Stock Index

State and local officials are often tasked with policy decisions that are influenced by projections of future economic conditions. However, properly assessing and predicting local economic performance is challenging. Common macroeconomic indicators can be helpful, but additional tools are needed. Stock indices have traditionally been used in the investment community to evaluate performance. While a recent surge in fundamental indexing has led to a debate over performance measurement, other uses of fundamental indices have been largely ignored. We introduce an employment-weighted stock index as a supplement to traditional forecasting measures for policymakers at the state and local level

Bermudagrass pasture management

The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

The importance of biotic entrainment for base flow fluvial sediment transport

Sediment transport is regarded as an abiotic process driven by geophysical energy, but zoogeomorphological activity indicates that biological energy can also fuel sediment movements. It is therefore prudent to measure the contribution that biota make to sediment transport, but comparisons of abiotic and biotic sediment flux are rare. For a stream in the UK, the contribution of crayfish bioturbation to suspended sediment flux was compared with the amount of sediment moved by hydraulic forcing. During baseflow periods, biotic fluxes can be isolated because nocturnal crayfish activity drives diel turbidity cycles, such that night-time increases above day-time lows are attributable to sediment suspension by crayfish. On average, crayfish bioturbation contributed at least 36% (430 kg) to monthly baseflow suspended sediment loads; this biotic surcharge added between 4.7 and 13.54 t (0.19 to 0.55 t km-2 yr-1) to the annual sediment yield. As anticipated, most sediment was moved by hydraulic forcing during floods and the biotic contribution from baseflow periods represented between 0.43 and 1.24% of the annual load. Crayfish activity is nonetheless an important impact during baseflow periods and the measured annual contribution may be a conservative estimate because of unusually prolonged flooding during the measurement period. In addition to direct sediment entrainment by bioturbation, crayfish burrowing supplies sediment to the channel for mobilization during floods so that the total biotic effect of crayfish is potentially greater than documented in this study. These results suggest that in rivers, during baseflow periods, bioturbation can entrain significant quantities of fine sediment into suspension with implications for the aquatic ecosystem and baseflow sediment fluxes. Energy from life rather than from elevation can make significant contributions to sediment fluxes

Does cycle commuting reduce the risk of mental ill-health? An instrumental variable analysis using distance to nearest cycle path

BackgroundPrevious studies have linked cycling with improved mental wellbeing but these studies tend to use cross-sectional survey data that have small sample sizes and self-reported health measures, and are potentially susceptible to omitted-variable bias and reverse causation. We use an instrumental variable approach and an objective measure of mental ill-health taken from linked administrative data to ask: ‘Does cycle commuting reduce the risk of mental ill-health?’MethodsOur study links data on commuting in Edinburgh and Glasgow from the Scottish population census with mental health prescriptions from the National Health Service Prescribing Information System records. We use road distance from home to nearest cycle path as an instrumental variable for cycle commuting.ResultsIn total, 378 253 people aged 16–74 years living and working in the City of Edinburgh and Glasgow City council areas at the 2011 census were included in our study; 1.85% of commuters in Glasgow and 4.8% of commuters in Edinburgh cycled to work. Amongst cyclists, 9% had a prescription for mental health compared with 14% amongst non-cyclists. Using a bivariate probit model, we estimate a mean average reduction in prescriptions for antidepressants and/or anxiolytics in the 5 years following the census of –15.1% (95% CI: –15.3% to –15.0%) amongst cycle commuters compared with those who use any other mode to commute.ConclusionsThis work suggests that cycle commuting is causally related to reduced mental ill-health and provides further evidence in support of the promotion of active travel to encourage commuters travelling shorter distances to shift to cycle commutes

A decade of monitoring Atlantic cod Gadus morhua spawning aggregations in Massachusetts Bay using passive acoustics

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Caiger, P. E., Dean, M. J., DeAngelis, A. I., Hatch, L. T., Rice, A. N., Stanley, J. A., Tholke, C., Zemeckis, D. R., & Van Parijs, S. M. A decade of monitoring Atlantic cod Gadus morhua spawning aggregations in Massachusetts Bay using passive acoustics. Marine Ecology Progress Series, 635, (2020): 89-103, doi:10.3354/meps13219.Atlantic cod Gadus morhua populations in the northeast USA have failed to recover since major declines in the 1970s and 1990s. To rebuild these stocks, managers need reliable information on spawning dynamics in order to design and implement control measures; discovering cost-effective and non-invasive monitoring techniques is also favorable. Atlantic cod form dense, site-fidelic spawning aggregations during which they vocalize, permitting acoustic detection of their presence at such times. The objective of this study was to detect spawning activity of Atlantic cod using multiple fixed-station passive acoustic recorders to sample across Massachusetts Bay during the winter spawning period. A generalized linear modeling approach was used to investigate spatio-temporal trends of cod vocalizing over 10 consecutive winter spawning seasons (2007-2016), the longest such timeline of any passive acoustic monitoring of a fish species. The vocal activity of Atlantic cod was associated with diel, lunar, and seasonal cycles, with a higher probability of occurrence at night, during the full moon, and near the end of November. Following 2009 and 2010, there was a general decline in acoustic activity. Furthermore, the northwest corner of Stellwagen Bank was identified as an important spawning location. This project demonstrated the utility of passive acoustic monitoring in determining the presence of an acoustically active fish species, and provides valuable data for informing the management of this commercially, culturally, and ecologically important species.Thanks to Eli Bonnell, Genevieve Davis, Julianne Bonell, Samara Haver, and Eric Matzen for assistance in MARU deployments, Dana Gerlach and Heather Heenehan for help in passive acoustic data analysis, and the NEFSC passive acoustics group for useful discussions. Funding for 2007−2012 passive acoustic surveys was provided by Excelerate Energy and Neptune LNG to Cornell University. Fieldwork for 2013−2015 was funded through the 2013−2014 NOAA Saltonstall-Kennedy grant program (Award No. NA14NMF4270027), and jointly funded by The Nature Conservancy, Massachusetts Division of Marine Fisheries, and the Cabot Family Charitable Foundation. Funding for 2016 SoundTrap data was provided by NOAA’s Ocean Acoustics Program (4 Sanctuaries Project)