Effects of Different Silvicultural Treatments on the Distribution of Light in Upland Hardwood Forest Stands of the Cumberland Plateau.

Although manipulation of the light regime is a common goal of silvicultural treatments, the specific light conditions created are poorly documented for many forest types and geographic locations. To help quantify effects of silivicultural treatments on light conditions, basal area, canopy structure, and photosynthetically active radiation (PAR), collected both instantaneously and across time, were measured in central hardwood forests following silvicultural treatments. These measurements were used to: 1.) investigate the magnitudes of differences in understory percent ambient PAR following implementation of shelterwood and thinning treatments; 2.) document the specific amount and variability of understory percent ambient PAR in shelterwood treatments (mean residual basal area=21 ft2/ac [4.8 m2/ha]), thinning (78 ft2/ac [17.9 m2/ha]), and untreated controls (18 ft2/ac[4.1 m2/ha); and 3.) Examine relationships between: basal area and canopy cover; basal area and measured percent ambient PAR; and canopy cover and measured percent ambient PAR. It was found that greater light levels resulted from greater canopy removals. Indexes of variability in light across time and among locations within a stand were higher in the shelterwood and thinning treatments than in the uncut control. Simple linear regression relationships were observed between basal area and PAR (r2= 0.8784 for instantaneous measurements, r2= 0.9697 for continuous measurements), and basal area and canopy cover (r2=0.8479). Such relationships provide a means for including light management in forest planning and application of silivicultural treatments

The Academy of Dental Materials: Providing roots and wings.

ObjectivesThe long history of the Academy of Dental Materials (ADM) is documented with its strategies (a) to rapidly communicate science among its members, (b) to establish special awards to stimulate new science, and (c) to develop new dental materials scientists.MethodsWe searched the history of the last 35 years of the ADM newsletters, transactions, journals, and officer notes. We document the (a) presidents, (b) meeting history, (c) membership growth, and (d) development of special awards through 2019 with the recent creation of the ADM Marshall Post-Doctoral Award.ResultsThere are 36 years of recent ADM history, 42 international meetings, membership growth to 400 individuals from 15 countries, service of 19 presidents, Paffenbarger annual Awardees since 1989, induction of >200 fellows, and recognition of the first winner of Marshall Post-Doctoral Award in 2018. New directions for recruiting members are suggested. Three potential new thrusts for the organization are presented: artificial intelligence, genetic engineering, and intensive member mentoring.SignificanceThese suggestions for the ADM provide a path for the ADM to continue to adapt to the ever changing scientific landscape

Initial Public Offerings of Ballplayers

As a field study of choice under uncertainty, we examine baseball teams' investments in amateur players. Though most prospects fail to deliver any return on their multi-million dollar signing bonuses, returns on the minority who succeed easily offset these losses: the expected annual yield on the median first-round draftee is 33 percent. However, the pattern of returns is inconsistent with market efficiency. Yields are lower for high schoolers than collegians (27 percent vs. 43 percent), lower for pitchers than position players (24 percent vs. 41 percent), decline for later round long-shots, and may be negative under competitive bidding.Market efficiency; Bounded rationality; Prospect theory; Winner’s curse

Sampling the Porridge: A Comparison of Ordered Variable Regression with \u3cem\u3eF\u3c/em\u3e and \u3cem\u3eR\u3c/em\u3e\u3csup\u3e2\u3c/sup\u3e and Multiple Linear Regression with Corrected \u3cem\u3eF\u3c/em\u3e and \u3cem\u3eR\u3c/em\u3e\u3csup\u3e2\u3c/sup\u3e in the Presence of Multicollinearity

Differences between the multiple linear regression model with Corrected R2 and Corrected F and the ordered variable regression model with R2 and F when intercorrelation is present are illustrated with simulated and real-world data

The Goldilocks Dilemma: Impacts of Multicollinearity -- A Comparison of Simple Linear Regression, Multiple Regression, and Ordered Variable Regression Models

A common consideration concerning the application of multiple linear regression is the lack of independence among predictors (multicollinearity). The main purpose of this article is to introduce an alternative method of regression originally outlined by Woolf (1951), which completely eliminates the relatedness between the predictors in a multiple predictor setting

Survival, Breeding Frequency, and Migratory Orientation in the Jefferson Salamander, \u3ci\u3eAmbystoma Jeffersonianum\u3c/i\u3e

Accurate estimates of demographic parameters, such as survival and breeding frequency, are necessary for the conservation and management of animal populations. Additionally, life-history data are required for gaining an empirical understanding of the ecology of natural populations. We monitored a population of Jefferson Salamanders (Ambystoma jeffersonianum) breeding in a permanent mountain-top pond at the southern limit of this species’ geographic range in Virginia over four years. We used closed multistate mark-recapture models with Pollock\u27s robust design to estimate the demographic parameters of this population. Additionally, we used point-of-capture data to compare the orientation of migrations into and out of the pond within and among years. Our model selection results support consistent annual adult survival across years with higher estimates for males compared to females. Our estimates of the probability of breeding in sequential years were high for both sexes during the four years of our study. Our model rankings and capture probability estimates indicate that females had a higher probability of detection when entering the breeding pond, likely reflecting differences between the sexes in arrival time to the pond. We found directionality in some, but not all, annual migrations, despite indications of individual fidelity in orientation across years. Our study provides the first estimates of breeding probability and assessment of migratory orientation patterns for A. jeffersonianum and contributes to the understanding of the reproductive ecology and natural history of pond-breeding amphibians

Students\u27 Attitudes Toward Debt-A Study of Atkinson Faculty of Liberal and Professional Studies, York University, and Ryerson University

In Ontario, the university system has been put on notice that there will be financial consequences for those universities whose Ontario Student Assistance Plan (OSAP) default rates are greater than the norm. As a result, it is important to determine all of the factors that affect students\u27 decisions to borrow. This paper uses survey information gathered from Atkinson Faculty of Liberal and Professional Studies, York University, and Ryerson University to focus attention on the relationship between students\u27 attitudes toward going into debt to finance their university education and their actual borrowing behavior. The study found that when all else is held constant, students with positive attitudes toward debt are more likely than others to be on the OSAP

Antivortex Device for Multi-Outlet Liquid Reservoir

A liquid reservoir with a sump includes at least two outlet ports in fluid communication with a fluid conduit. An anti-vortex device includes a first plate extending across the at least two outlet ports and a second plate coupled to the first plate and extending substantially perpendicular to the first plate. The anti-vortex device is configured to disrupt formation of a vortex formed by liquid passing from the reservoir through said outlet ports

Antivortex Device and Method of Assembling Thereof

An antivortex device for use in suppressing formation of a vortex created by fluid flowing through multiple outlet ports defined in a sump is provided. The antivortex device includes a plurality of center plates extending through a central axis of the sump, an extension plate substantially aligned with one of the plurality of center plates and extending substantially radially outward from the central axis, and a top plate coupled to the plurality of center plates

X-ray Diffraction Analysis of Stratum Corneum Membrane Couplets

X-ray diffraction analysis was done on the membrane couplets isolated from newborn mouse stratum corneum. The same lipid reflections were observed for whole stratum corneum and couplets, adding further support to the thesis that stratum corneum lipid is intercellular in location rather than associated with the intracellular filamentous protein