Capture‐Recapture Methodology

Abstract

Capture‐recapture methods were initially developed to estimate human population abundance, but since that time have seen widespread use for fish and wildlife populations to estimate and model various parameters of population, metapopulation, and disease dynamics. Repeated sampling of marked animals provides information for estimating abundance and tracking the fate of individuals in the face of imperfect detection. Mark types have evolved from clipping or tagging to use of noninvasive methods such as photography of natural markings and DNA collection from feces. Survival estimation has been emphasized more recently as have transition probabilities between life history states and/or geographical locations, even where some states are unobservable or uncertain. Sophisticated software has been developed to handle highly parameterized models, including environmental and individual covariates, to conduct model selection, and to employ various estimation approaches such as maximum likelihood and Bayesian approaches. With these user‐friendly tools, complex statistical models for studying population dynamics have been made available to ecologists. The future will include a continuing trend toward integrating data types, both for tagged and untagged individuals, to produce more precise and robust population models.

Small‐angle X‐ray scattering as a useful supplementary technique to determine molecular masses of polyelectrolytes in solution

“…Some of the most employed methods to obtain absolute masses are mass spectroscopy, multiangle laser light scattering, membrane osmometry, and NMR, as well as size exclusion techniques such as size exclusion chromatograph and asymmetric flow field-flow fractionation (AF4) which, combined with multidetector and refractive index analysis, can give information on masses and polydispersity indexes (PDIs). [1][2][3][4][5] However, most of those methods are time consuming (especially that based on osmometry), sample consuming or may not be applied to all types of polymers. As an example, end-group analysis using NMR is probably the most straightforward and quick analysis method to determine M n , but it requires the presence of a clearly recognizable, nonoverlapping end-group signal with a good signal-to-noise ratio, which is not always present especially for high-molecular mass polymers.…”