The Influence of Sampling Methods on the Estimation of Population Structure in Painted Turtles

1966 ◽  
Vol 75 (2) ◽  
pp. 325 ◽  
Author(s):  
Catherine Ream ◽  
Robert Ream
Keyword(s):  
Population Structure ◽  
Sampling Methods ◽  
Painted Turtles

scholarly journals Assessing the Impacts of Urbanization on Sex Ratios of Painted Turtles (Chrysemys picta)

Diversity ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 72 ◽  
Author(s):  
John P. Vanek ◽  
Gary A. Glowacki
Keyword(s):  
Population Structure ◽  
Sex Ratios ◽  
Monitoring Program ◽  
Chrysemys Picta ◽  
Adult Survival ◽  
Sampling Location ◽  
Road Mortality ◽  
Population Declines ◽  
Road Density ◽  
Painted Turtles

Turtles are particularly susceptible to the negative impacts of urbanization due to low mobility and a life history strategy emphasizing long generation times and high adult survival. In addition to declines directly through habitat loss, urbanization has been hypothesized to limit populations of aquatic turtles through changes in population structure, as adult females are disproportionally killed on and near roads, leading to male-biased populations, which can lead to population declines or local extirpations. The purpose of this study was to better understand how urbanization impacts the sex ratios of painted turtles (Chrysemys picta) in an urban ecosystem, as empirical results linking male-biased turtle populations to roads and urbanization are mixed. Using eight years of trapping data from a long-term monitoring program in a suburb of Chicago, IL, USA, we report one of the most male-biased populations ( x ¯ = 75% male) of turtles in the USA, consistent with prevailing road mortality hypotheses. However, we found no evidence that male-biased populations were related to road density or the amount of protected area around a sampling location and found that impervious surface (a metric of urbanization) was weakly related to less male-biased populations. Our results highlight the importance of replicating ecological studies across space and time and the difficulty in assessing population structure in aquatic turtles. We suggest that active conservation measures may be warranted for the continued persistence of urban turtle populations.

Population-size estimators and unequal catchability in painted turtles

1998 ◽  
Vol 76 (3) ◽  
pp. 458-465 ◽  
Author(s):  
Nicola Koper ◽  
Ronald J Brooks
Keyword(s):  
Population Size ◽  
Sampling Methods ◽  
Ecological Research ◽  
Closed Population ◽  
Painted Turtles ◽  
Population Size Estimates ◽  
Population Sizes ◽  
Almost All ◽  
Size Estimates ◽  
True Population

Most methods of estimating population size from mark-recapture data assume equal catchability. Failure to meet this assumption may have profound effects on population-size estimates. We used 3 sampling methods to compare population-size estimates derived from Petersen, Schumacher and Eschmeyer, and Jolly-Seber models with the true size of a closed population of painted turtles (Chrysemys picta) in Algonquin Park, Ontario. We found significant variation in capture probabilities, and almost all population-size estimates were far below the true population size. To try to improve the accuracy of the estimates, we applied 4 techniques commonly recommended for reducing bias when catchability is unequal: (i) changing sampling methods, (ii) using several sampling methods simultaneously, (iii) dividing the population by sex, and (iv) calculating population sizes using the computer program CAPTURE. None of the 4 methods reduced the error that resulted from unequal catchability in any of the estimates sufficiently for these methods to be suitable for management of populations or for ecological research.

Going Beyond 3-D Imaging: Automated 3-D Montaged image Analysis of Cytological Specimens

1996 ◽  
Vol 54 ◽  
pp. 282-283
Author(s):  
Badrinath Roysam ◽  
Hakan Ancin ◽  
Douglas E. Becker ◽  
Robert W. Mackin ◽  
Matthew M. Chestnut ◽  
...  
Keyword(s):  
Image Analysis ◽  
Structural Changes ◽  
Sampling Methods ◽  
Spatial Clustering ◽  
Three Dimensional ◽  
Field Of View ◽  
Cell Counting ◽  
Depth Of Field ◽  
Tissue Cell ◽  
Tissue Organization

This paper summarizes recent advances made by this group in the automated three-dimensional (3-D) image analysis of cytological specimens that are much thicker than the depth of field, and much wider than the field of view of the microscope. The imaging of thick samples is motivated by the need to sample large volumes of tissue rapidly, make more accurate measurements than possible with 2-D sampling, and also to perform analysis in a manner that preserves the relative locations and 3-D structures of the cells. The motivation to study specimens much wider than the field of view arises when measurements and insights at the tissue, rather than the cell level are needed.The term “analysis” indicates a activities ranging from cell counting, neuron tracing, cell morphometry, measurement of tracers, through characterization of large populations of cells with regard to higher-level tissue organization by detecting patterns such as 3-D spatial clustering, the presence of subpopulations, and their relationships to each other. Of even more interest are changes in these parameters as a function of development, and as a reaction to external stimuli. There is a widespread need to measure structural changes in tissue caused by toxins, physiologic states, biochemicals, aging, development, and electrochemical or physical stimuli. These agents could affect the number of cells per unit volume of tissue, cell volume and shape, and cause structural changes in individual cells, inter-connections, or subtle changes in higher-level tissue architecture. It is important to process large intact volumes of tissue to achieve adequate sampling and sensitivity to subtle changes. It is desirable to perform such studies rapidly, with utmost automation, and at minimal cost. Automated 3-D image analysis methods offer unique advantages and opportunities, without making simplifying assumptions of tissue uniformity, unlike random sampling methods such as stereology.12 Although stereological methods are known to be statistically unbiased, they may not be statistically efficient. Another disadvantage of sampling methods is the lack of full visual confirmation - an attractive feature of image analysis based methods.

Pengaruh Tekanan Waktu, Locus Of Control , Tindakan Supervisi, Dan Materialitas Terhadap Penghentian Prematur Atas Prosedur Audit Studi Kasus Pada Kantor Akuntan Publik Daerah Istimewa Yogyakarta Tahun 2015

2017 ◽  
Vol 24 (1) ◽  
pp. 35-53
Author(s):  
Sulastiningsih Sulastiningsih ◽  
Intan Ayu Candra
Keyword(s):  
Locus Of Control ◽  
Premature Termination ◽  
Sampling Methods ◽  
Time Pressure ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Test Reliability ◽  
Friedman Test ◽  
Independent Variables ◽  
Public Accountant

The purpose of this study is to prove: (1) Time pressure, locus of control, the action of supervision and materiality partially affect the premature termination of the audit procedures (2) Time pressure, locus of control, supervision and materiality simultaneously affect the premature termination on the audit procedures. This research was conducted in Public Accountant firm in Yogyakarta region of which total 12 samples of KAP, by distributing 105 questionnaires, and 57 questionnaires were returned (54%). 34 of the returned questionnaires can be processed (34%). The samples in this study were determined by using non-probability sampling, one of purposive sampling methods. Data analysis consisted of: (1) validity test, reliability test and classical assumption. The result showed that the instruments used are quite reliable and valid (2) multiple linear regression analysis. The results are (a) Some of independent variables partially affect premature termination of the audit procedure, while the action of supervision does not influence premature termination of audit procedures (b) All independent variables influence simultaneously to the premature termination of the audit procedures (c) All independent variables showed that as much as 55% it affects on premature termination of the audit procedures, the rest of it are influenced by other variables. (3) Friedman Test. The result shows that there are order of priority of audit procedures being terminated.

72. Evaluation of Different Sampling Methods for Determining Dust Lead Loading on Residential Carpet Surfaces

2000 ◽  
Author(s):  
Z. Bai ◽  
J. Zhang ◽  
G. Rhoads ◽  
P. Lioy ◽  
S. Tsai ◽  
...  
Keyword(s):  
Sampling Methods

431. Improved Generation and Sampling Methods for Tests Using Mycobacterium Aerosols

1999 ◽  
Author(s):  
N. McCullough ◽  
L. Brosseau ◽  
C. Pilon ◽  
D. Vesley
Keyword(s):  
Sampling Methods
Sign in / Sign up

Export Citation Format

Share Document