Factors Influencing Reporting and Harvest Probabilities in North American Geese

ABSTRACT We assessed variation in reporting probabilities of standard bands among species, populations, harvest locations, and size classes of North American geese to enable estimation of unbiased harvest probabilities. We included reward (US$10, $20, $30, $50, or $100) and control ($0) banded geese from 16 recognized goose populations of 4 species: Canada (Branta canadensis), cackling (B. hutchinsii), Ross's (Chen rossii), and snow geese (C. caerulescens). We incorporated spatially explicit direct recoveries and live recaptures into a multinomial model to estimate reporting, harvest, and band-retention probabilities. We compared various models for estimating harvest probabilities at country (United States vs. Canada), flyway (5 administrative regions), and harvest area (i.e., flyways divided into northern and southern sections) scales. Mean reporting probability of standard bands was 0.73 (95% CI = 0.69–0.77). Point estimates of reporting probabilities for goose populations or spatial units varied from 0.52 to 0.93, but confidence intervals for individual estimates overlapped and model selection indicated that models with species, population, or spatial effects were less parsimonious than those without these effects. Our estimates were similar to recently reported estimates for mallards (Anas platyrhynchos). We provide current harvest probability estimates for these populations using our direct measures of reporting probability, improving the accuracy of previous estimates obtained from recovery probabilities alone. Goose managers and researchers throughout North America can use our reporting probabilities to correct recovery probabilities estimated from standard banding operations for deriving spatially explicit harvest probabilities.     

Substrate-induced interconversion of protein quaternary structure isoforms

Human porphobilinogen synthase (PBGS) can exist in two dramatically different quaternary structure isoforms, which have been proposed to be in dynamic equilibrium. The quaternary structure isoforms of PBGS result from two alternative conformations of the monomer; one monomer structure assembles into a high activity octamer, whereas the other monomer structure assembles into a low activity hexamer. The kinetic behavior of these oligomers led to the hypothesis that turnover facilitates the interconversion of the oligomeric structures. The current work demonstrates that the interactions of ligands at the enzyme active site promote the structural interconversion between human PBGS quaternary structure isoforms, favoring formation of the octamer. This observation illustrates that the assembly and disassembly of oligomeric proteins can be facilitated by the protein motions that accompany enzymatic catalysis.     

The Control of Color in Mammals

SYNOPSIS. Recent advances in the biology of mammalian pigmentationare reviewed.Particular attention is given to emerging informationon the integration of pigmentary events occurring at differentlevels of biological organization within mammalian skin andhair. The structural and functional significance of keratinocytesand melanocytes as components of mammalian epidermal melaninunits is viewed from this perspective. New evidence on the natureof genetic, developmental, endocrine, and radiation influenceson performance of melanocytes and the establishment of pigmentarypatterns is summarized.     

Ecophenotypic strategies of dalmanellid brachiopods

General ecophenotypic patterns, of particular interest when they apply to all, or most, taxa of the group concerned, can never be demonstrated until after monophyletic taxa have been recognized, that is, until after the initial stages of phylogeny construction have been carried out. In criticizing certain dalmanellid phylogenies, and based in large part on a study of five 'species subgroups'. Hurst & Watkins (1978; Geologica et Palaeontologica 12 ) postulate ecophenotypic patterns for Isorthis , and Hurst (1978; Palaeontology 21 ) postulates general patterns of ecophenotypic variation for dalmanellid brachiopods. These patterns may be invalid for four reasons: (1) Univariate and 'bivariate' statistical analysis of the samples used to define the five subgroups reveals no significant differences between subgroups, or vertical trends, for the very morphological characters claimed to exhibit the ecophenotypic patterns; (2) Hurst & Watkins' discriminant function analysis contains procedural errors and its results are ambiguous; (3) several of the five subgroups represent mixtures of unrelated taxa; (4) in recognizing the alleged patterns, Hurst & Watkins ignored contrary evidence from many taxa (and from many dalmanellid studies). □ Brachiopoda, Dalmanellidae, Silurian, ecology, evolution, systematics.     

On Autotropism in Botrytis: Measurement Technique and Control by CO(2)

The mutual orientation of the germination of nearby pairs of Botrytis spores growing in a simple, dilute medium was studied. If the medium is equilibrated with room air, they show a very strong tendency to germinate both toward each other and in a cis arrangement, i.e., toward the same side of the line joining their centers. If the medium is equilibrated with air enriched with 0.3% or 3% CO₂, (i.e., 10 or 100 times the normal CO₂ concentration) then the cells show an equally strong tendency to germinate away from each other. The interaction shows little dependence upon pH.