The effects of endrin on Microtus and Peromyscus. II. Enclosed field populations

1972 ◽  
Vol 50 (6) ◽  
pp. 885-896 ◽  
Author(s):  
Ralph D. Morris
Keyword(s):  
Simple Model ◽  
Microtus Pennsylvanicus ◽  
Experimental Population ◽  
Population Changes ◽  
Grassland Species ◽  
Live Trapping ◽  
Competitive Interference ◽  
Experimental Enclosure ◽  
Better Than ◽  
Significant Mortality

Effects of endrin on enclosed field populations of Microtus pennsylvanicus and Peromyscus maniculatus were investigated in two 2-acre enclosures near Saskatoon, Saskatchewan. After removal trapping and introduction of marked animals, population changes were assessed by live-trapping at 2-week intervals from June to September 1968. The experimental enclosure was sprayed with endrin at 8.0 oz per acre on July 14, 1968.Before endrin was applied Microtus were more abundant in the experimental enclosure than in the control enclosure. Endrin caused immediate and significant mortality in the experimental population. Microtus which survived the spray subsequently survived as well as their control counterparts. Recruits entering the experimental population during post-spray periods survived significantly better than young entering the more crowded control population. This survival, combined with active post-spray breeding, yielded a final experimental population which significantly exceeded the control.Peromyscus escaped readily from both enclosures. Losses from the experimental enclosure were significantly greater than from the control enclosure during both pre-spray and post-spray periods. The tendency for Peromyscus to leave the experimental enclosure in greater numbers is related to the paucity of suitable woodland habitat and to inferred competitive interference from the grassland species Microtus.Finally, a simple model is presented which demonstrates the several ramifications of a biocide stress on small mammal populations.

Experimental studies of competitive interaction in a two-species system. I. Microtus and Clethrionomys species in enclosures

1969 ◽  
Vol 47 (5) ◽  
pp. 1059-1082 ◽  
Author(s):  
P. R. Grant
Keyword(s):  
Experimental Studies ◽  
Microtus Pennsylvanicus ◽  
Interspecific Interaction ◽  
Clethrionomys Gapperi ◽  
Grid Pattern ◽  
Grassland Species ◽  
Live Trapping ◽  
Deciduous Woodland ◽  
Poor Recruitment ◽  
The Difference

A 17-week experiment was performed in 1966 to determine under what conditions Microtus pennsylvanicus and Clethrionomys gapperi leave their usual habitat and enter another, and the significance of interspecific interaction. Three 1-ac enclosures were used, each containing equisized blocks of deciduous woodland and grassland. Into one enclosure three pairs of the woodland species Clethrionomys gapperi only were introduced. Into another, four pairs of the grassland species Microtus pennsylvanicus only were introduced. Into the remaining enclosure three pairs of Clethrionomys gapperi and four pairs of Microtus Pennsylvanicus were introduced. All these were placed in the appropriate habitats. Subsequent movements of the animals were determined by live-trapping with Longworth traps arranged in a grid pattern and used on one to three consecutive nights and (or) days per week. Both species reproduced. Because of poor recruitment, the population densities of Clethrionomys gapperi changed very little. Microtus pennsylvanicus reproduced with greater success, and the final densities were about three times greater than the starting densities.But for one individual, Microtus pennsylvanicus stayed entirely within the grassland habitat. From the beginning, and throughout the experiment, Clethrionomys gapperi individuals moved into the grassland habitat. Recruits entered the grassland proportionately more frequently than did the adults, but the adults entered the grassland more frequently in the second half of the experiment than in the first half. One adult female and her presumed offspring were trapped only in the grassland. Several data implicate density effects as contributors to the movement of Clethrionomys gapperi into the grassland habitat. It is proposed that the carrying capacity of the woodland habitat was exceeded by the initial number of animals introduced, and that the stimulus or stimuli to move into the grassland arose from social interaction above a threshold level.Many more Clethrionomys gapperi were trapped in the grassland (I) without Microtus pennsylvanicus (except for occasional transgressors) than in the grassland (II) with Microtus pennsylvanicus. After a possible trapping bias is taken into account it is estimated that the difference is no less than 40% of the larger number. It is suggested that interactions with Microtus pennsylvanicus, possibly reinforced by the signs of that species, were responsible for the fewer movements of Clethrionomys gapperi into the grassland of enclosure II.

scholarly journals Are two brands better than one? Investigating the effects of co-branding in advertising on audience memory

2017 ◽  
Vol 29 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Cathy Nguyen ◽  
Jenni Romaniuk ◽  
Margaret Faulkner ◽  
Justin Cohen
Keyword(s):  
Return On Investment ◽  
Brand Name ◽  
Interference Theory ◽  
Advertising Expenditure ◽  
Competitive Interference ◽  
Negative Effect ◽  
Neutral Effect ◽  
Better Than

Abstract Co-branded advertising, where advertisements feature two partnered brands from different categories, should ideally benefit both brands. We test this assertion by studying the effect of featuring a second brand in advertisements on ad and brand name memorability, and the role of category context on which brand is recalled. Our test covers online display advertisements for consumer-packaged brands paired with charity and retailer brands in three markets (USA, UK, and Australia). Independent sample comparisons across 54 brand pairs show that advertising two brands has a neutral effect on ad memorability and negative effect on brand memorability. Furthermore, the advertisement’s category context determines which of the brands is recalled. Our findings support a competitive interference theory of dual-brand processing, whereby the two brands compete for attention resources. The results have implications for the return on investment from advertising expenditure, which will vary substantively depending on whether the costs of advertising are shared or borne by one brand in the pair.

Evaluation of a very simple model for predicting the moisture content of eucalypt litter

2011 ◽  
Vol 20 (8) ◽  
pp. 1000 ◽  
Author(s):  
Jason J. Sharples ◽  
Richard H. D. McRae
Keyword(s):  
Simple Model ◽  
Moisture Content ◽  
Observational Data ◽  
Short Note ◽  
Fuel Moisture ◽  
Computational Power ◽  
Complex Process ◽  
Fuel Moisture Content ◽  
Better Than

Operational prediction of wildfire behaviour requires assessment of dead fuel moisture content to an acceptable degree of accuracy. Ideally, the methods of assessment should be simple enough to implement in most operational settings, including those where computational power is a constraining factor. In this short note, we describe a very simple model for estimating dead fine fuel moisture content and compare its predictions with several fuel moisture observations and the predictions of a complex process-based model and two of its simplifications. Remarkably, the very simple model is shown to fit the observational data just as well, if not slightly better, than the more sophisticated models. The result highlights the issues of engineering and parsimony of models for dead fuel moisture content. These issues are briefly discussed.

η PRODUCTION IN PROTON-PROTON COLLISIONS AT 72 MeV EXCESS ENERGY

2009 ◽  
Vol 24 (02n03) ◽  
pp. 446-449
Author(s):  
◽  
H. PETTERSSON ◽  
M. BASHKANOV ◽  
D. BOGOSLOWSKY ◽  
H. CALÉN ◽  
...  
Keyword(s):  
Simple Model ◽  
Strong Influence ◽  
Excess Energy ◽  
Exchange Model ◽  
Final States ◽  
Proton Proton ◽  
Proton Collisions ◽  
Boson Exchange ◽  
Proton Proton Collisions ◽  
Better Than

The production of η mesons at an excess energy of 72 MeV has been studied in the reaction pp → pp(η)γγ. It is shown that a simple model with Pp final states included reproduces observed differential distributions better than the same model restricted to Ss , Sd and Ds final states. The strong influence of the Pp states could be taken as an indication of ρ dominance within an one boson exchange model for the excitation of N *(1535).

Bait preference for remote camera trap studies of the endangered northern quoll (Dasyurus hallucatus)

2017 ◽  
Vol 39 (1) ◽  
pp. 72 ◽  
Author(s):  
Caitlin Austin ◽  
Katherine Tuft ◽  
Daniel Ramp ◽  
Teigan Cremona ◽  
Jonathan K. Webb
Keyword(s):  
Peanut Butter ◽  
Camera Traps ◽  
Livestock Grazing ◽  
Population Estimates ◽  
Northern Australia ◽  
Cane Toad ◽  
Live Trapping ◽  
Remote Camera ◽  
Reliable Methods ◽  
Better Than

Estimating population size is crucial for managing populations of threatened species. In the Top End of northern Australia, populations of northern quolls (Dasyurus hallucatus), already affected by livestock grazing, inappropriate burning regimes and predation, have collapsed following the spread of the toxic cane toad (Rhinella marina). Cane toads are currently invading the Kimberley, where they pose a threat to quoll populations. To manage these populations, we need reliable methods for detecting and estimating quoll abundance. We deployed camera traps with lures containing tuna, peanut butter or no bait and found that baited cameras performed better than the unbaited control. Cameras with a tuna lure detected more individuals than cameras baited with peanut butter or no bait. Cameras with a tuna lure yielded more photographs per quoll than those baited with peanut butter or no bait. We identified individual quolls from unique spot patterns and found multiple photographs improved the accuracy of identification. We also found that population estimates for the sample area derived from camera trapping were consistent with those from live trapping using mark–recapture techniques.

Effect of Process Oriented Instruction on Thought Processes in Gifted Students

1981 ◽  
Vol 47 (5) ◽  
pp. 326-330
Author(s):  
Alexinia Y. Baldwin
Keyword(s):  
Instructional Strategy ◽  
Gifted Students ◽  
Experimental Population ◽  
Thought Processes ◽  
Treatment Groups ◽  
Classroom Activities ◽  
Study Results ◽  
Process Oriented ◽  
And Control ◽  
Better Than

A process oriented instructional strategy to develop higher level thought processes in gifted students was studied to determine whether or not gifted students of the experimental group would advance more in this area than would the students in the average ability and treatment groups. A total of 312 seventh grade students from widely differing geographic areas and ethnic groups participated in the study. Results showed that under research conditions gifted students in the experimental population did significantly better than average students in the experimental and control groups. Although there was a mean difference in the scores of the experimental and control gifted classes, this difference was not significant at the .01 level. The evaluative comments of the students and teachers and the data from the Classroom Activities Questionnaire provided insight into the processes being used and the effect of lower level thought processes on developing higher level thought processes.

scholarly journals A simple model for cloud radiative forcing

2009 ◽  
Vol 9 (15) ◽  
pp. 5751-5758 ◽  
Author(s):  
T. Corti ◽  
T. Peter
Keyword(s):  
Energy Balance ◽  
Simple Model ◽  
Radiative Transfer ◽  
Radiative Forcing ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Cloud Radiative Forcing ◽  
Wide Range ◽  
Model Equations ◽  
Better Than

Abstract. We present a simple model for the longwave and shortwave cloud radiative forcing based on the evaluation of extensive radiative transfer calculations, covering a global range of conditions. The simplicity of the model equations fosters the understanding on how clouds affect the Earth's energy balance. In comparison with results from a comprehensive radiative transfer model, the accuracy of our parameterization is typically better than 20%. We demonstrate the usefulness of our model using the example of tropical cirrus clouds. We conclude that possible applications for the model include the convenient estimate of cloud radiative forcing for a wide range of conditions, the evaluation of the sensitivity to changes in environmental conditions, and as a tool in education. An online version of the model is available at http://www.iac.ethz.ch/url/crf.

scholarly journals Predicting Ideological Prejudice: A Pre-Registered Replication of Brandt (2017)

2018 ◽  
Author(s):  
Mark John Brandt
Keyword(s):  
Time Series ◽  
Simple Model ◽  
Political Ideology ◽  
Meta Analysis ◽  
Null Model ◽  
National Election ◽  
Target Group ◽  
Archival Data ◽  
Target Groups ◽  
Better Than

Brandt (2017) demonstrated that a simple model using the perceived ideology of a target group can predict the size and direction of the association between political ideology and prejudice. A meta-analysis of four studies showed that this simple ideology only model performs better than a null model and models using the perceived conventionalism, status, and choice of being a member of the target groups. This report describes a preregistered replication which uses data from the American National Election Study’s 2016 Time Series (N = 2616), archival data that was only made available after the study was preregistered. The findings of Brandt (2017) were replicated and the meta-analysis reported in Brandt (2017) is updated with these new data.

scholarly journals A simple model for cloud radiative forcing

2009 ◽  
Vol 9 (2) ◽  
pp. 8541-8560 ◽  
Author(s):  
T. Corti ◽  
T. Peter
Keyword(s):  
Energy Balance ◽  
Simple Model ◽  
Radiative Transfer ◽  
Environmental Conditions ◽  
Radiative Forcing ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Cloud Radiative Forcing ◽  
Model Equations ◽  
Better Than

Abstract. We present a simple model for the longwave and shortwave cloud radiative forcing based on the evaluation of extensive radiative transfer calculations. The simplicity of the model equations fosters the understanding on how clouds affect the Earth's energy balance. In comparison with results from a comprehensive radiative transfer model, the accuracy of our parameterization is typically better than 20%. We demonstrate the usefulness of our model using the example of tropical cirrus clouds. We conclude that possible applications for the model include the fast estimate of cloud radiative forcing, the evaluation of the sensitivity to changes in environmental conditions, and as a tool in education.

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