Character education for the deaf and hard of hearing

This paper presents a curriculum guide for structured character education for deaf and hearing-impaired children. A list of suggested age-appropriate activities, role play ideas, thematic children’s books, and assistive internet resources are provided.

El viaje a Camelot de Bartolomé de las Casas (Estudios)

La autora lee la Brevísima, de Bartolomé de las Casas, en el contexto del auge del imaginario caballeresco en el siglo XVI español, propiciado por las empresas de la Conquista y la Colonia, y que alcanzó igualmente a las gestas religiosas. Estudia este reflejo caballeresco –ensombrecido tal vez por el dramatismo y la violencia de lo narrado, entre otras razones–, empezando por la promesa lascasiana de ennoblecer a campesinos pacíficos a cambio de que colonizaran con justicia, resalta el carácter cortés y pacífico de los indios, así como de sus valores de tinte caballeresco («lo mismo los varones que las mujeres, muertas antes que entregar su honra o faltar a sus esposos», destaca su respeto a la jerarquía, natural o adquirida, y a las responsabilidades de cada cual, incluidas las del buen rey, que protege a sus vasallos y defiende los límites de su territorio), incluso distingue su delicadeza corporal como signo de nobleza. El patrón narrativo de la Brevísima es similar al de muchas obras de la tradición caballeresca. Utiliza todos estos elementos en un retrato civilizado de los indios, presentados viviendo en sociedad y según las virtudes cristianas antes de la llegada de los españoles, en un equilibrio que sería amenazado por los afanes desmedidos de los conquistadores.

Rediscovering the King of Woodpeckers: Exploring the Implications

The Ivory-billed Woodpecker has long held a special place in the psyche of North American conservation, eliciting unusually colorful prose, even from scientists, as an icon of the wild. The reverence in which it was held did little to slow the habitat loss that led to its apparent extinction 60 years ago. A consequence of the emotion and attention associated with the amazing rediscovery of this species is that conservation biologists will be under considerable pressure to make good on this “second chance.” This poses a challenge to conservation paradigms that has important political consequences. First, the decline of the species is due to habitat loss, recovery from which has been much more seldom achieved than recovery from declines due to impacts on vital rates. This challenge is exacerbated by the enormous area requirements of the species. Second, the species at best exists as a critically small population. It will be difficult to make the case that a viable population can be established without undermining the small population paradigm that underlies conservation strategies for many other species. This has already resulted in some political backlash. Conservation of this species is best based on the one point of clear scientific consensus, that habitat is limiting, but this may result in additional political backlash because of conflicts with other land uses.

Bayesian estimation of ancestral character states on phylogenies

Biologists frequently attempt to infer the character states at ancestral nodes of a phylogeny from the distribution of traits observed in contemporary organisms. Because phylogenies are normally inferences from data, it is desirable to account for the uncertainty in estimates of the tree and its branch lengths when making inferences about ancestral states or other comparative parameters. Here we present a general Bayesian approach for testing comparative hypotheses across statistically justified samples of phylogenies, focusing on the specific issue of reconstructing ancestral states. The method uses Markov chain Monte Carlo techniques for sampling phylogenetic trees and for investigating the parameters of a statistical model of trait evolution. We describe how to combine information about the uncertainty of the phylogeny with uncertainty in the estimate of the ancestral state. Our approach does not constrain the sample of trees only to those that contain the ancestral node or nodes of interest, and we show how to reconstruct ancestral states of uncertain nodes using a most-recent-common-ancestor approach. We illustrate the methods with data on ribonuclease evolution in the Artiodactyla. Software implementing the methods ( BayesMultiState) is available from the authors.

A phylogenetic mixture model for detecting pattern-heterogeneity in gene sequence or character-state data

We describe a general likelihood-based 'mixture model' for inferring phylogenetic trees from gene-sequence or other character-state data. The model accommodates cases in which different sites in the alignment evolve in qualitatively distinct ways, but does not require prior knowledge of these patterns or partitioning of the data. We call this qualitative variability in the pattern of evolution across sites "pattern-heterogeneity" to distinguish it from both a homogenous process of evolution and from one characterized principally by differences in rates of evolution. We present studies to show that the model correctly retrieves the signals of pattern-heterogeneity from simulated gene-sequence data, and we apply the method to protein-coding genes and to a ribosomal 12S data set. The mixture model outperforms conventional partitioning in both these data sets. We implement the mixture model such that it can simultaneously detect rate- and pattern-heterogeneity. The model simplifies to a homogeneous model or a rate- variability model as special cases, and therefore always performs at least as well as these two approaches, and often considerably improves upon them. We make the model available within a Bayesian Markov-chain Monte Carlo framework for phylogenetic inference, as an easy-to-use computer program.