Texas Forestry Paper No. 24

Comparisons of seedlings from east texas loblolly, shortleaf and suspected hybrid pineshttps://scholarworks.sfasu.edu/texas_forestry_papers/1012/thumbnail.jp

Siviculture and Management Strategies Applicable to Southern Hardwoods

Southern hardwood forests stretch from the Virginias to Florida and from the mid-Atlantic to Missouri. They can generally be grouped into upland forests and bottomland forests. The upland hardwood forests of the southern region are usually associated with the mountainous topography of the Appalachians and Ozarks. Bottomland hardwoods are found along the floodplains of larger rivers in the Atlantic and Gulf Coastal Plains, including the Mississippi River floodplain. Southern hardwood forests are owned by a variety of governmental and private owners, but the vast majority of owners are nonindustrial private individuals. These owners seldom engage in intensive forest management, often exploiting the resource. The silvicultural systems applicable to the management of hardwoods are the same as those recommended for pines, but in hardwood management, reliance on natural regeneration is more common than use of plantation silviculture. Oak species are very important in the southern hardwood forests, and lack of oak regeneration in present-day forests is a major concern. Lack of fire and the resurgence of white-tailed deer throughout the southern region are proposed as reasons for poor oak regeneration. Many stands, either due to their stage of development or neglect, are in need of intermediate management operations such as thinning and improvement cutting. Crop-tree management is a method that is particularly useful in southern hardwoods. It was concluded that although hardwoods make up a significant part of the southern forest resource, they are generally managed with less intensity than pines, and hardwood management is an opportunity area for the South in the future

Texas Forestry Paper No. 13

Pollen development and release in loblolly and shortleaf pine near nacogdoches, texas, 1971https://scholarworks.sfasu.edu/texas_forestry_papers/1024/thumbnail.jp

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 × 10−8), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution

An aggregate quantity framework for measuring and decomposing productivity change

Total factor productivity (TFP) can be defined as the ratio of an aggregate output to an aggregate input. This definition naturally leads to TFP indexes that can be expressed as the ratio of an output quantity index to an input quantity index. If the aggregator functions satisfy certain regularity properties then these TFP indexes are said to be multiplicativelycomplete. This paper formally defines what is meant by completeness and reveals that (1) the class of multiplicatively complete TFP indexes includes Laspeyres, Paasche, Fisher, Törnqvist and Hicks-Moorsteen indexes, (2) the popular Malmquist TFP index of Caves et al. (Econometrica 50(6):1393-1414, 1982a) is incomplete, implying it cannot always be interpreted as a measure of productivity change, (3) all multiplicatively complete TFP indexes can be exhaustively decomposed into measures of technical change and efficiency change, and (4) the efficiency change component can be further decomposed into measures of technical, mix and scale efficiency change. Artificial data are used to illustrate the decomposition of Hicks-Moorsteen and Fisher TFP indexes