An Advancement in Removing Extraneous Color From Wood for Low-Magnification Reflected-Light Image Analysis of Conifer Tree Rings

This paper describes the removal of extraneous color from increment cores of conifers prior to reflected-light image analysis of tree rings. Ponderosa pine in central New Mexico was chosen for study. Peroxide bleaching was used as a pretreatment to remove extraneous color and still yield usable wood for image analysis. The cores were bleached in 3% peroxide raised to pH 12 and heated to 60° C, and then they were soaked in 95% ethanol and rinsed in water. The cores were dried slowly to avoid checking or cracking. This treatment removed heartwood color while leaving the wood reasonably sound. Wood reflectance and latewood width were measured using reflected-light image analysis. For dendroclimatic modeling, best-subsets regression was used to determine the strongest predictive model, which was May-September rainfall using latewood reflectance and latewood width. The ability to dendroclimatically model and reconstruct summer precipitation is contingent on having latewood reflectance (density) measurements, and reconstructing summer precipitation in the Southwest will enhance paleoclimatology of the region. Image analysis with reflected white light is thus closer to being more widely applicable in dendrochronology

Bayesian localization of CNV candidates in WGS data within minutes

Background: Full Bayesian inference for detecting copy number variants (CNV) from whole-genome sequencing (WGS) data is still largely infeasible due to computational demands. A recently introduced approach to perform Forward-Backward Gibbs sampling using dynamic Haar wavelet compression has alleviated issues of convergence and, to some extent, speed. Yet, the problem remains challenging in practice. Results: In this paper, we propose an improved algorithmic framework for this approach. We provide new space-efficient data structures to query sufficient statistics in logarithmic time, based on a linear-Time, in-place transform of the data, which also improves on the compression ratio. We also propose a new approach to efficiently store and update marginal state counts obtained from the Gibbs sampler. Conclusions: Using this approach, we discover several CNV candidates in two rat populations divergently selected for tame and aggressive behavior, consistent with earlier results concerning the domestication syndrome as well as experimental observations. Computationally, we observe a 29.5-fold decrease in memory, an average 5.8-fold speedup, as well as a 191-fold decrease in minor page faults. We also observe that metrics varied greatly in the old implementation, but not the new one. We conjecture that this is due to the better compression scheme. The fully Bayesian segmentation of the entire WGS data set required 3.5 min and 1.24 GB of memory, and can hence be performed on a commodity laptop

Sectional rearrangement of arborescent clades of Croton (Euphorbiaceae) in South America: Evolution of arillate seeds and a new species, Croton domatifer

Most of the arborescent Croton species in the New World were treated by Webster as belonging either to C. sect. Cyclostigma Griseb. or C. sect. Luntia (Neck. ex Raf.) G.L. Webster. The circumscription of C. sect. Cyclostigma has been treated recently. In this paper we focus on C. sect. Luntia, which was subdivided by Webster into two subsections, C. subsect. Matourenses and subsect. Cuneati. Using chloroplast trnL‐F and nuclear ITS DNA sequence data, morphology and a broader sampling of additional Croton lineages, we found that the two subsections are not closely related and form distinct monophyletic groups. Substantial morphological differences support the molecular data. A taxonomic recircumscription of the two subsections, elevated to sectional level, is proposed. A key and taxonomic revision, with new synonyms, is provided for C. sect. Cuneati; together with the description of a new species from the coastal mountains of Venezuela, Croton domatifer. The new species is the only one in the genus known to possess leaf domatia. We infer that species in the Cuneati clade have lost the typical Croton caruncle, and some of them have evolved a different, specialized type of aril. We hypothesize that the arillate seeds are an adaptation to dispersal by fish in the Orinoco and Amazon river basins.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147226/1/tax594014.pd

Characteristics of Ten Tropical Hardwoods from Certified Forests in Bolivia. Part II. Natural Durability to Decay Fungi

The natural durability of 10 lesser known, commercially available Bolivian hardwoods to decay fungi was evaluated using a modified ASTM soil-block analysis for 12 weeks. The blocks were then retested for an additional 12 weeks to determine their level of decay resistance, as determined by percentage of weight loss. Astronium urundeuva, Caesalpinia cf. pluviosa, Schinopsis quebrachocolorado, and Tabebuia sp. (Iapacho group) were found to be highly resistant to decay; Amburana cearensis, Anadenanthera colubrina (syn: A. macrocarpa), Aspidosperma cylindrocarpon, Diplotropis purpurea, and Guibourtia chodatiana, resistant to decay; and Phyllostylon rhamnoides, moderately resistant to decay. We conclude that an extended soil-bottle test is an effective tool for assessing the level of natural durability of these and other tropical species

Identificación de maderas colombianas utilizando el Xylotron: Prueba de concepto de una colaboración internacional

Field deployable computer vision wood identification systems can play a key role in combating illegal logging in the real world. This work used 764 xylarium specimens from 84 taxa to develop an image data set to train a classifier to identify 14 commercial Colombian timbers. We imaged specimens from various xylaria outside Colombia, trained and evaluated an initial identification model, then collected additional images from a Colombian xylarium (BOFw), and incorporated those images to refine and produce a final model. The specimen classification accuracy of this final model was ~ 97%, demonstrating that including local specimens can augment the accuracy and reliability of the XyloTron system. Our study demonstrates the first deployable computer vision model for wood identification in Colombia, developed on a timescale of months rather than years by leveraging international cooperation. We conclude that field testing and advanced forensic and machine learning training are the next logical steps.Sistemas de identificación automatizada de maderas pueden fortalecer la lucha contra el tráfico ilegal de maderas. Este trabajo utilizó 764 especímenes de xilotecas, correspondientes a 84 taxones, para desarrollar un modelo de identificación para 14 especies comerciales de Colombia. Se comenzó colectando imágenes de especímenes provenientes de xilotecas fuera de Colombia, que se utilizaron para entrenar y evaluar un modelo inicial. Se colectaron imágenes adicionales provenientes de una xiloteca Colombiana (BOFw), que se utilizaron para refinar y producir el modelo final. La capacidad de reconocimiento de este modelo fue del ~97%, demostrando que incluir muestras locales aumenta la precisión y confiabilidad del sistema [XyloTron]. Este estudio presenta el primer modelo de vision computarizada para identificación de maderas en Colombia, desarrollado en una escala de tiempo corta y bajo cooperación internacional. Concluimos que pruebas en campo y capacitación forense y en aprendizaje automatizado, son los siguientes pasos lógicos a seguir

Figured grain in aspen is heritable and not affected by graft-transmissible signals

Figure can add value to wood products, but its occurrence is unpredictable. A first step in reliably producing figured wood is determining whether it is faithfully transmitted to progeny via sexual and asexual reproduction. We describe a 26-year-old male aspen genotype, designated ‘Curly Poplar’, which was shown to be a Populus × canescens hybrid using microsatellite markers. All rooted cuttings of this genotype exhibited an undulating pattern on the radial surface that was not seen in the control trees, all of which showed a smooth radial surface and straight grain. We observed spiral grain with a magnitude of 2.77 ± 0.12°/cm from vertical in 11-month-old, field-grown rooted Curly Poplar cuttings, but spiral grain was not apparent in wood from the 26-year-old mature ortet that supplied these cuttings. Veneer cut from the mature tree exhibited a novel type of figure that we called ‘Scattered Moiré’. Reciprocal grafts between Curly Poplar and various non-figured aspens showed that a graft-transmissible signals did not appear to be involved in figure formation in Curly Poplar or the induction of figure in straight-grained trees. Curly Poplar was crossed to a straight-grained clone to test the inheritance of the gene(s) responsible for figure. Samples from the resulting population revealed that 79 out of 377 seedlings exhibited figure. A Chi-square test led to the rejection of a 1:1 segregation ratio between figured and non-figured phenotypes (p < 0.01), but not of a 1:3 segregation ratio (p 0.0793). Overall, these analyses showed that figure in Curly Poplar is under genetic control, but its inheritance may not be simple

Review of macroscopic features for hardwood and softwood identification and a proposal for a new character list

With the adoption of a number of anti-illegal logging laws, treaties, memoranda, and international agreements around the world, there is broad and renewed interest in wood identification, especially in the field at the macroscopic level. In response to this interest, and to begin to fill an obvious gap in the corpus of wood anatomical reference material, we review several prominent Englishlanguage publications on macroscopic wood identification in order to form a list of characters. We compile characters and organize them in the spirit of the IAWA lists for hardwood and softwood microscopic identification, present the state of the art as it exists, attempt to reconcile the different sets of definitions, characters, and character states, then present our proposed working-list. It is our intent with this publication to open an international discussion regarding the standardization of macroscopic wood identification features, and it is our hope that such a discussion can include critical works from the non-English literature. We also call for an illustrated glossary to accompany the proposed list. A standard lexicon to describe wood at the macroscopic level will simplify the preparation of identification documents and permit the ready translation of keys and other references for easy use and deployment around the world. \ua9 2015 International Association of Wood Anatomists

"Ray-intrusive" laticifers in species of Croton section Cyclostigma (Euphorbiaceae)

A description of the occurrence and structure of “ray-intrusive” laticifers in the rays of species of Croton section Cyclostigma is provided. The systematic significance of laticifers within Croton section Cyclostigma is briefly discussed in relation to the section’s known production of red latex, commonly called “dragon’s blood”. A developmental hypothesis is offered and discussed in the context of the assumption that all laticifers in wood rays are non-articulated.Peer reviewe