The first occurrence of a toxodont (Mammalia, Notoungulata) in the United States

This is the publisher's version, also available electronically from http://www.tandfonline.com/doi/abs/10.1080/02724634.2012.711405#.U1qJK4UvDGJ.Toxodonts were a group of large-sized notoungulates of South American origin. They were diverse and widespread in South America in deposits ranging in age from late Oligocene to late Pleistocene. Sparse remains have been found from the Pleistocene of isolated regions of Central America. All of the Central American specimens have been referred to the genus Mixotoxodon (Van Frank, 1950). They were not previously known north of the southern Mexican states of Michoacan and Veracruz, except for an unconfirmed report of an occurrence in Tamaulipas (Arroyo-Cabrales et al., 2010). Here we report the occurrence of a single toxodont tooth, a left upper third molar, from late Pleistocene deposits in Harris County, Texas (30◦N). This is the first record of toxodonts, or any notoungulate, in the United States and extends the geographic range of this group 1600 km north of their previously known localities at Hihuitlán, Michoacan (18◦52' 3"0 N, 103◦24' 14 "W) and La Estribera, Veracruz (18◦07 '01.27" N, 94◦53 '15.59W) (Polaco et al., 2004) to latitude 30◦N

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Estimation of stem attributes using a combination of terrestrial and airborne laser scanning

Properties of individual trees can be estimated from airborne laser scanning (ALS) data provided that the scanning is dense enough and the positions of field-measured trees are available as training data. However, such detailed manual field measurements are laborious. This paper presents new methods to use terrestrial laser scanning (TLS) for automatic measurements of tree stems and to further link these ground measurements to ALS data analyzed at the single tree level. The methods have been validated in six 80 × 80 m field plots in spruce-dominated forest (lat. 58°N, long. 13°E). In a first step, individual tree stems were automatically detected from TLS data. The root mean square error (RMSE) for DBH was 38.0 mm (13.1 %), and the bias was 1.6 mm (0.5 %). In a second step, trees detected from the TLS data were automatically co-registered and linked with the corresponding trees detected from the ALS data. In a third step, tree level regression models were created for stem attributes derived from the TLS data using independent variables derived from trees detected from the ALS data. Leave-one-out cross-validation for one field plot at a time provided an RMSE for tree level ALS estimates trained with TLS data of 46.0 mm (15.4 %) for DBH, 9.4 dm (3.7 %) for tree height, and 197.4 dm3 (34.0 %) for stem volume, which was nearly as accurate as when data from manual field inventory were used for training