Ground squirrel damage and control in Montana

The Columbian ground squirrel (Spermophilus columbianus), Richardson ground squirrel (Spermophilus richardsoni), and blacktail prairie dog (Cynomys ludovicianus) cause millions of dollars of loss to Montana agriculture each year. Montana's ground squirrel and prairie dog control programs are based upon local organization and operation with technical assistance being provided by the Montana Department of Livestock Vertebrate Pest Control Bureau. The results of field research programs using zinc phosphide, Compound 1080 and strychnine grain baits to control these species are reported

RODENTICIDE RESIDUES IN ANIMAL CARCASSES AND THEIR RELEVANCE TO SECONDARY HAZARDS

Some complexities and limitations of using carcass residue data to determine secondary hazard to nontarget species are discussed. The roles of chemical and toxicological properties of the rodenticide such as metabolism, excretion, organs of retention, site of absorption and latent period in secondary hazard are reviewed and examples given. The possible effects of bait composition and application methods, the behavioral response of the nontarget species, and local environmental factors upon secondary hazard are outlined

RODENTICIDE RESIDUES IN ANIMAL CARCASSES AND THEIR RELEVANCE TO SECONDARY HAZARDS

Some complexities and limitations of using carcass residue data to determine secondary hazard to nontarget species are discussed. The roles of chemical and toxicological properties of the rodenticide such as metabolism, excretion, organs of retention, site of absorption and latent period in secondary hazard are reviewed and examples given. The possible effects of bait composition and application methods, the behavioral response of the nontarget species, and local environmental factors upon secondary hazard are outlined

Thermal denaturation of fluctuating finite DNA chains: the role of bending rigidity in bubble nucleation

Statistical DNA models available in the literature are often effective models where the base-pair state only (unbroken or broken) is considered. Because of a decrease by a factor of 30 of the effective bending rigidity of a sequence of broken bonds, or bubble, compared to the double stranded state, the inclusion of the molecular conformational degrees of freedom in a more general mesoscopic model is needed. In this paper we do so by presenting a 1D Ising model, which describes the internal base pair states, coupled to a discrete worm like chain model describing the chain configurations [J. Palmeri, M. Manghi, and N. Destainville, Phys. Rev. Lett. 99, 088103 (2007)]. This coupled model is exactly solved using a transfer matrix technique that presents an analogy with the path integral treatment of a quantum two-state diatomic molecule. When the chain fluctuations are integrated out, the denaturation transition temperature and width emerge naturally as an explicit function of the model parameters of a well defined Hamiltonian, revealing that the transition is driven by the difference in bending (entropy dominated) free energy between bubble and double-stranded segments. The calculated melting curve (fraction of open base pairs) is in good agreement with the experimental melting profile of polydA-polydT. The predicted variation of the mean-square-radius as a function of temperature leads to a coherent novel explanation for the experimentally observed thermal viscosity transition. Finally, the influence of the DNA strand length is studied in detail, underlining the importance of finite size effects, even for DNA made of several thousand base pairs.Comment: Latex, 28 pages pdf, 9 figure

OLFACTORY RESPONSES OF DEER MICE TO DOUGLAS-FIR SEED VOLATILES

An attempt was made to identify the olfactory cues produced by Douglas-fir seeds which attract deer mice (Peromyscus maniculatus) to the seeds. The olfactometers used are described, and the merits of different statistical analyses of the data are discussed. The odors produced by whole Douglas-fir seed and by the endosperm were preferred among the fractions tested to date. Deer mice were repelled by Douglas-fir turpentine, cedar oil, and, to a lesser degree, one extract

Poultry

Getting winter eggs from hens / D. C. Kennard and V. D. Chamberlin -- The protein requirements of growing pullets / R. M. Bethke, Paul R. Record and D. C. Kennard -- Coarse versus fine mash / D. C. Kennard -- Chicken vices / D. C. Kennard -- Tipping the beaks / D. C. Kennard -- Use of woven wire in poultry keeping -- Sun parlors for chick

OLFACTORY RESPONSES OF DEER MICE TO DOUGLAS-FIR SEED VOLATILES

An attempt was made to identify the olfactory cues produced by Douglas-fir seeds which attract deer mice (Peromyscus maniculatus) to the seeds. The olfactometers used are described, and the merits of different statistical analyses of the data are discussed. The odors produced by whole Douglas-fir seed and by the endosperm were preferred among the fractions tested to date. Deer mice were repelled by Douglas-fir turpentine, cedar oil, and, to a lesser degree, one extract

Should Species Distribution Models Account for Spatial Autocorrelation? A Test of Model Projections Across Eight Millennia of Climate Change

Aim: The distributions of many organisms are spatially autocorrelated, but it is unclear whether including spatial terms in species distribution models (SDMs) improves projections of species distributions under climate change. We provide one of the first comparative evaluations of the ability of a purely spatial SDM, a purely non-spatial SDM and a SDM that combines spatial and environmental information to project species distributions across eight millennia of climate change. Location: Eastern North America. Methods: To distinguish between the importance of climatic versus spatial explanatory variables we fit three Bayesian SDMs to modern occurrence data for Fagus and Tsuga, two tree genera whose distributions can be reliably inferred from fossil pollen: a spatially varying intercept model, a non-spatial model with climatic variables and a spatially varying intercept plus climate model. Using palaeoclimate data with a high temporal resolution, we hindcasted the SDMs in 1000-year time steps for 8000 years, and compared model projections with palynological data for the same periods. Results: For both genera, spatial SDMs provided better fits to the calibration data, more accurate predictions of a hold-out validation dataset of modern trees and higher variance in current predictions and hindcasted projections than non-spatial SDMs. Performance of non-spatial and spatial SDMs according to the area under the receiver operating curve varied by genus. For both genera, false negative rates between non-spatial and spatial models were similar, but spatial models had lower false positive rates than non-spatial models. Main conclusions: The inclusion of computationally demanding spatial random effects in SDMs may be warranted when ecological or evolutionary processes prevent taxa from shifting their distributions or when the cost of false positives is high.Organismic and Evolutionary Biolog

Roles of stiffness and excluded volume in DNA denaturation

The nature and the universal properties of DNA thermal denaturation are investigated by Monte Carlo simulations. For suitable lattice models we determine the exponent c describing the decay of the probability distribution of denaturated loops of length l, $P \sim l^{-c}$. If excluded volume effects are fully taken into account, c= 2.10(4) is consistent with a first order transition. The stiffness of the double stranded chain has the effect of sharpening the transition, if it is continuous, but not of changing its order and the value of the exponent c, which is also robust with respect to inclusion of specific base-pair sequence heterogeneities.Comment: RevTeX 4 Pages and 4 PostScript figures included. Final version as publishe