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To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1523-1739.2007.00756.x Byline: MARK C. VANDERWEL (*[double dagger]), JAY R. MALCOLM (*), STEPHEN C. MILLS ([dagger]) Keywords: Akaike's information criterion; bird conservation; forest management; habitat alteration; partial-harvest silviculture; tree retention Abstract: Abstract: Most data on the effects of partial-harvest silviculture (where live trees are purposely retained at the time of harvest) on birds come from one or a few discrete harvesting treatments. It is thus difficult to infer species responses across a continuous gradient of tree retention from individual studies. To quantify the levels of tree retention expected to produce specified changes in the relative abundance of individual species, we carried out a meta-analysis of 42 studies that examined the impacts of uniform partial harvesting on North American birds. Of 34 species, sigmoidal models showed a negative effect of harvesting for 14 species and a positive effect for 6 species. Ovenbirds (Seiurus aurocapilla) and Brown Creepers (Certhia americana) were the species most sensitive to harvesting. Most of the 14 species that were negatively affected by harvesting showed 25%, 50%, and 75% reductions in abundance (relative to control sites) at tree retention levels ranging from 45 to 85%, 30-70%, and 15-50%, respectively. A few species, such as Yellow-rumped Warblers (Dendroica coronata), exhibited these levels of response at lower tree retention or were not predicted to decrease by 75% in harvested stands. Five of the 6 species that were positively affected by harvesting showed at least a 50% increase in abundance at nearly all levels of tree retention, although other early successional bird species did not appear to benefit from the relatively small openings created by uniform partial harvesting. Three of 20 species exhibited stronger responses to harvesting at a given level of tree retention in boreal and northern mixed forests of North America than other regions of the continent, but, with these exceptions, lack of variation among forest regions supported the broad-scale generality of species' responses to harvesting. The species response models we developed represent useful tools for evaluating stand-level impacts of partial harvesting on birds within an adaptive management framework. Uniform partial harvesting at light and, to a lesser degree, moderate intensities may be effective approaches to managing habitat for late successional bird species as part of broader ecosystem-based forest management. Abstract (Spanish): Un Meta Analisis de las Respuestas de Aves a la Cosecha Parcial Uniforme en Norte America Resumen: La mayoria de los datos sobre efectos de la silvicultura de cosecha parcial (retencion de arboles vivos al momento de la cosecha) sobre las aves provienen de uno o unos cuantos tratamientos de cosecha discretos. Por lo tanto, es dificil inferir las respuestas de las especies a lo largo de un gradiente continuo de retencion de arboles a partir de estudios individuales. Para cuantificar los niveles de retencion de arboles esperados para producir cambios especificados en la abundancia relativa de especies individuales, realizamos un meta analisis de 42 estudios que examinaron los impactos de la cosecha parcial uniforme sobre aves de Norte America. Los modelos sigmoides mostraron efectos negativos para 14 de 34 especies y un efecto positivo para 6 especies. Seiurus aurocapilla y Certhia americana fueron las especies mas sensibles a la cosecha. La mayoria de las 14 especies que fueron afectadas negativamente mostraron reducciones en abundancia (en relacion con sitios control) de 25%, 50% y 75% en niveles de retencion de arboles de 45-85%, 30-70% y 15-50%, respectivamente. Unas cuantas especies, como Dendroica coronata, exhibieron estos niveles de respuesta a menor retencion de arboles o no se predijo su decremento en 75% en sitios cosechados. Cinco de las 6 especies que fueron afectadas positivamente mostraron un incremento de abundancia por lo menos de 50% en casi todos los niveles de retencion de arboles, aunque otras especies de aves caracteristicas de etapas sucesionales tempranas aparentemente no se beneficiaron de los claros relativamente pequenos creados por la cosecha parcial uniforme. Tres de 20 especies exhibieron respuestas mas fuertes a la cosecha en un determinado nivel de retencion de arboles en bosques boreales y en bosques mixtos en Norte America que en otras regiones del continente, pero, con estas excepciones, la falta de variacion entre bosques soporto la generalidad, a gran escala, de las respuestas de las especies a la cosecha. Los modelos de respuesta de las especies que desarrollamos representan herramientas utiles para la evaluacion de impactos de la cosecha parcial sobre las aves en el marco del manejo adaptativo. La cosecha parcial uniforme en intensidades bajas y, en menor grado, moderadas pueden ser metodos efectivos para manejar el habitat para especies de aves caracteristicas de etapas sucesionales avanzadas como parte de la gestion de bosques basada en ecosistemas. Author Affiliation: (*)Faculty of Forestry, University of Toronto, 33 Willcocks Street, Toronto, ON M5S 3B3, Canada ([dagger])Northeast Science & Information Section, Ontario Ministry of Natural Resources, Highway 101 East, P.O. Bag 3020, South Porcupine, ON P0N 1H0, Canada Article History: Paper submitted February 15, 2007; revised manuscript accepted April 11, 2007. Article note: ([double dagger]) email mark.vanderwel@utoronto.ca

High school athletes seem particularly predisposed to dental injury, but athletic mouthguards have an excellent track record of success in reducing the severity and incidence of dental injuries in sports. Therefore, it has been suggested that mouthguards be made mandatory for high school athletes who participate in sports with risk of injury. The National Federation of State High School Associations currently recommends that mouthguards be mandated for high school football, lacrosse, ice hockey, and field hockey players as well as for wrestlers who are wearing orthodontic appliances. Different states have tried to mandate additional sports with varying degrees of success. This article summarizes the process that leads to rule changes for high school athletes at the national level and discusses the history of 4 states--Minnesota, Maine, New Hampshire, and Massachusetts--that have tried to mandate mouthguards for different sports. Common complaints that lead to the cessation of mouthguard rules, such as speech considerations, breathing ability, and cleanliness, are discussed. [ABSTRACT FROM AUTHOR]

Protection of athletes during sporting activities was of some concern even in the late 1800s. That concern continues, over 140 years later. In baseball, safety for the catcher was of primary concern because of inherent risks of being "behind the plate" while balls are pitched, bats are swung, and runners attempting to score come barreling in. Doug Allison was the skilled catcher for the 1869 Cincinnati Red Stockings who was known to use certain objects for self-protection, including George Wright's rubber "Mouthpiece." This report reviews earliest development of mouth protection in baseball, as known through reports of the times, and Doug Allison's career., (Copyright 2023 © American Academy of the History of Dentistry.)