Impact of Spatial and Temporal Variation in Calf Survival on the Growth of Elk Populations

Abstract: The realized impact of a vital rate on population growth (λ) is determined by both the relative influence of the vital rate on λ (elasticity) and its magnitude of variability. We estimated mean survival and reproductive rates in elk (Cervus elaphus) and spatial and temporal variation in these rates from 37 sources located primarily across the Rocky Mountain region and northwestern United States. We removed sampling variance from estimates of process variance both within and across vital-rate data sets using the variance discounting method developed by White (2000). Deterministic elasticities calculated from a population matrix model parameterized with these mean vital rates ranked adult female survival (e_Scow = 0.869) much higher than calf survival (e_Scalf = 0.131). However, process variance in calf survival was >11 times greater than process variance in female survival across data sets and 10 times greater on average within studies. We conducted Life-Stage Simulation Analysis to incorporate both vital-rate elasticity patterns and empirical estimates of variability to identify those vital rates most influential in elk population dynamics. The overwhelming magnitude of variation in calf survival explained 75% of the variation in the population growth rates generated from 1,000 matrix replicates, compared to just 16% of the variation in λ explained by variation in female survival. Variation in calf survival greatly impacts elk population growth and calls into question the utility of classical elasticity analysis alone for guiding elk management. These results also suggest that the majority of interannual variability that wildlife managers document in late-winter and spring elk surveys is attributable to variation in calf survival over the previous year and less influenced by variation in the harvest of females during the preceding autumn. To meet elk population size objectives, managers should consider the inherent variation in calf survival, and its apparent sensitivity to management, in addition to female harvest.     

Construction of Prediction Intervals in Location-Scale Families

Let x₁ ≤x₂ ≤x₃ … ≤x_r be the r smallest observations out of n observations from a location-scale family with density $ \frac{1}{\sigma}f\left({\frac{{x - \mu}}{\sigma}} \right) $ where μ and σ are the location and the scale parameters respectively. The goal is to construct a prediction interval of the form $ \left({\hat \mu + k_1 \hat \sigma,\,\hat \mu + k_2 \hat \sigma} \right) $ for a location-scale invariant function, T(Y) = T(Y₁, …, Y_m), of m future observations from the same distribution. Given any invariant estimators $ \hat \mu $ and $ \hat \sigma $, we have developed a general procedure for how to compute the values of k₁ and k₂. The two attractive features of the procedure are that it does not require any distributional knowledge of the joint distribution of the estimators beyond their first two raw moments and $ \hat \mu $ and $ \hat \sigma $ can be any invariant estimators of μ and σ. Examples with real data have been given and extensive simulation study showing the performance of the procedure is also offered.     

Regulation of changes in cytosolic Ca2+ and Na+ concentrations in rat submandibular gland acini exposed to carbachol and ATP

The relationship between cytosolic concentrations of Ca²⁺ (Ca) and Na⁺ (Na) were studied in preparations of rat submandibular and pancreatic acini loaded with the Ca²⁺-sensitive dye Fura-2 or the Na⁺-sensitive dye SBFI. Pancreatic acini showed no changes in Na during either transient or persistent changes in Ca. Increases in Ca produced by exposure of submandibular gland acini to carbachol, a muscarinic cholinergic agonist, were followed by an increase in Na after a delay of 5–10 s. When Ca²⁺ stores were mobilized without Ca²⁺ influx Na also increased, but in acini loaded with BAPTA, a nonfluorescent Ca²⁺ chelator, the transient increase in Ca²⁺ caused by mobilization of stored Ca²⁺ was virtually abolished, as was the increase in Na. In the presence of ionomycin, increases in Ca were followed by increases in Na. Ca²⁺-dependent increases in Na were abolished in Na⁺-free buffer and by the presence of furosemide, a blocker of Na⁺-K⁺-2Cl⁻ cotransport. In other studies, extracellular ATP (ATP_o) produced an increase in Ca and Na. The steady-state increase in Ca was reduced by increasing extracellular Na⁺ concentrations (Na) in dose-dependent fashion (IC₅₀ = 16.4 ± 4.7 mM Na⁺). Likewise, increasing Na reduced ATP_o-stimulated ⁴⁵Ca²⁺ uptake at steady state (IC₅₀ = 15.8 ± 9.2 mM Na⁺). Changing Na had no effect on carbachol-stimulated increases in Ca. We conclude that, in rat submandibular gland acini, ATP_o promotes an increase in Ca and Na via a common influx pathway and that, under physiologic conditions, Na⁺ significantly limits the ATP_o-stimulated increase in Ca. In the presence of carbachol, however, Na rises in Ca-dependent fashion in submandibular gland acini via stimulation of Na⁺-K⁺-2Cl⁻ cotransport. © 1996 Wiley-Liss, Inc.     

Levels of DNA strand breaks and superoxide in phorbol ester-treated human granulocytes

Phorbol ester treatment of granulocytes triggers release of superoxide (O) and a concomitant burst of DNA strand breaks. The relationship between the amount of O and the number of DNA breaks has not previously been explored. To quantify the relatively large amount of O generated over a 40-min period by 1 × 10⁶ granulocytes/mL, a discontinuous “10-min pulse” method employing cytochrome c was used; 140 nmol O per 1 × 10⁶ cells was detected. DNA strand breaks were quantified by fluorimetric analysis of DNA unwinding (FADU). To vary the level of O released by cells, inhibitors of the respiratory burst were used. Sodium fluoride (1–10 mM) and staurosporine (2–10 nM) both inhibited O production. In both cases, however, inhibition of strand breakage was considerably more pronounced than inhibition of O. Zinc chloride (50–200 μM) inhibited both O and DNA breaks, approximately equally. Dinophysistoxin-1 (okadaic acid) inhibited O production more effectively than it inhibited DNA breaks. O dismutes to H₂O₂, a reactive oxygen species known to cause DNA breaks. The addition of catalase to remove extracellular H₂O₂ had no effect on DNA breakage. Using pulse field gel electrophoresis, few double-stranded breaks were detected compared to the number detected by FADU, indicating that about 95% of breaks were single-stranded. The level of DNA breaks is not directly related to the amount of extracellular O or H₂O₂ in PMA-stimulated granulocytes. We conclude that either an intracellular pool of these reactive oxygen species is involved in breakage or that the metabolic inhibitors are affecting a novel strand break pathway. J. Cell. Biochem. 66:219–228, 1997. © 1997 Wiley-Liss Inc.     

Conformation of poly(L-arginine). I. Effects of anions

The conformational transition of poly(L -agrignine) by binding with various mono-, di-, and polyvalent anions, especially with SO, was studied by CD measurements. The intramolecular random coil-to-α-helix conformational transition and the subsequent transition to the β-turn-like structure was caused by binding with SO. The binding data obtained from equilibrium dialysis experiments showed that the α-helical conformation of poly(L -arginine) is stabilized at a 1:3 stoichiometric ratio of bound SO to arginine residue; at higher free SO concentrations, the α-helix converts to the β-turn-like structure accompanied by a decrease in amount of bound SO. The same conformaitonal transition of poly(L -arginine) also occurred in the solutions of other divalent anions (SO, CO, and HPO) and polyvalent anions (P₂O, P₃O). Among the monovalent anions examined, CIO and dodecyl sulfate were effective in including α-helical conformation, while the other monovalent anions (OH^?, Cl^?, F^?, H₂PO, HCO and CIO) failed to induce poly(L -arginine) to assume the α-helical conformation. Thus, we noticed that, except for dodecyl sufate, the terahedral structure is common to the α-helix-forming anions. A well-defined model to the α-helical poly(L -arginine)/anion complex was proposed, in which both the binding stoichiometry of anions to the arginine residue and the tetrahedral structure of anions were taken into consideration. Based on these results, it was concluded that the tetrahedral-type anions stabilize the α-helical conformation of poly(L -arginine) by crosslinking between two guanidinium groups of nearby side chains on the same α-helix through the ringed structures stabilized by hydrogen bonds as well as by electrostatic interaction. Throughout the study it was noticed that the structural behavior of poly(L -arginine) toward anions is distinct from that of poly(L -lysine).     

Enantioselective interactions of inversion-labile trigonal iron(II) complexes upon binding to DNA

We studied the interactions of the substitution-inert inversion-labile complexes Fe(bipy) and Fe(phen) [and the inversion-stable complex Ru(bipy)] with DNA. The association of these complexes to DNA is mainly electrostatic, and Fe(phen) shows a more effective binding to DNA than the two bipyridyl complexes, possibly owing to a different binding mode. The interactions are enantioselective, leading to a Pfeiffer shift in the diastereomeric inversion equilibria and an excess of the Δ-enantiomer of Fe(phen) and Fe(bipy), which is directly monitorable through CD. The partition constants for the inversion equilibrium range from 1.3 to 2.0 for Fe(bipy) and Fe(phen), depending on ionic conditions. From flow LD information about the orientation of the complexes on DNA was obtained: it is consistent with a fit of the Δ-enantiomer in the major groove of the right-handed DNA helix. The mechanisms of interaction are discussed against equilibrium, spectroscopic, and kinetic data.     

The role of predator removal,density-dependence,and environmental factors on mallard duckling survival in North Dakota

Duckling survival is an important component of mallard (Anas platyrhynchos) recruitment and population growth, yet many factors regulating duckling survival are poorly understood. We investigated factors affecting mallard duckling survival in the drift prairie of northeastern North Dakota, 2006–2007. Mammalian meso-predators were removed by trapping on 4 92.3 km² study sites and another 4 study sites served as controls. We monitored 169 broods using telemetry and periodic resighting, and we modeled cumulative survival to 30 days of age using the nest survival module in Program MARK. Duckling survival was not affected by predator removal ( , 85% CI: 0.182–0.234; , 85% CI: 0.155–0.211) and was only weakly negatively correlated with duckling density. Duckling survival was higher in 2007 ( , 85% CI: 0.193–0.355) than 2006 ( , 85% CI: 0.084–0.252) and increased with total seasonal and semipermanent wetland area and declined with perennial cover in the surrounding landscape. Broods that hatched earlier in the season (especially in 2006) and ducklings that were heavier at hatch also had higher survival. Our estimates of duckling survival are among the lowest reported for mallards and contradict previous research in Saskatchewan that found predator removal increased duckling survival. However, our results are consistent with other studies suggesting that earlier hatch date, increased wetland availability, and better duckling condition lead to increased survival. Management actions that increase wetland density, improve nest success early in the season, and potentially target brood-specific predators such as mink (Neovison vison) would likely lead to higher duckling survival. © 2011 The Wildlife Society.     

Reactivity of Hg(II) with superoxide: Evidence for the catalytic dismutation of superoxide by HG(II)

Mercuric ion, a well-known nephrotoxin, promotes oxidative tissue damage to kidney cells. One principal toxic action of Hg(II) is the disruption of mitochondrial functions, although the exact significance of this effect with regard to Hg(II) toxicity is poorly understood. In studies of the effects of Hg(II) on superoxide (O) and hydrogen peroxide (H₂O₂) production by rat kidney mitochondria, Hg(II) (1–6 μM), in the presence of antimycin A, caused a concentration-dependent increase (up to fivefold) in mitochondrial H₂O₂ production but an apparent decrease in mitochondrial O production. Hg(II) also inhibited O-dependent cytochrome c reduction (IC₅₀ ≈?2–3 μM) when O was produced from xanthine oxidase. In contrast, Hg(I) did not react with O in either system, suggesting little involvement of Hg(I) in the apparent dismutation of O by Hg(II). Hg(II) also inhibited the reactions of KO₂ (i.e., O) with hemin or horseradish peroxidase dissolved in dimethyl sulfoxide (DMSO). Finally, a combination of Hg(II) and KO₂ in DMSO resulted in a stable UV absorbance spectrum [currently assigned Hg(II)-peroxide] distinct from either Hg(II) or KO₂. These results suggest that Hg(II), despite possessing little redox activity, enhances the rate of O dismutation, leading to increased production of H₂O₂ by renal mitochondria. This property of Hg(II) may contribute to the oxidative tissue-damaging properties of mercury compounds.     

A stereospecific complex of poly(I) with ammonium ion

We describe conditions which lead to complete helix formation of poly(I) in the presence of NH. Binding of NH is shown to be specific in the presence of Li⁺, which does not by itself support helix formation under these conditions. The NH–poly(I) complex is characterized by uv, CD, and ir spectroscopy. The CD spectrum is strikingly different from those of the Na⁺ or K⁺ complexes, the first extremum being changed from negative for the metal ions to positive for NH. A stereospecific model is proposed for the NH–poly(I) helix in which the N of NH is located on the axis of the four-stranded helix, midway between planar tetramers formed by the bases. The model is consistent with the tetrahedral symmetry of NH, the requirement for four acceptable hydrogen bonds, the observed stability of the helix, and the accepted geometry of the backbone.     

How Large is the Probability for the Estimate of a Variance Component to be Negative?

For a balanced one-way classification, where the normally distributed observations obey a random model y_ij=μ+b_i+c_ij with two variance components var (b_i) = δ and var (c_ij) = δ, the probability is given that the analysis of variance estimate of δ will be negative. This probability depends on δ/δ and the degrees of freedom in the ANOVA table. Tables for this probability are given. If the normally distributed observations obey an intra-class correlation model, the probability that the Mean Square between groups is smaller than the Mean Square within groups can also be evaluated from the given tables.     

Equi-replicated balanced block designs generated by a balanced matrix

In this paper it is shown that if N= \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop \sum \limits_{i = 1}^{S_h} $\end{document} c_ihN_ih, where c_ih are some non-negative integer numbers and N_ih are such incidence matrices that A_h = \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop \sum \limits_{i = 1}^{S_h} $\end{document} i N_ih is a balanced matrix defined by SHAH (1959), for h = 1, 2,…, p, then a block design with an incidence matrix Ñ = [N, N,…,N] is an equi-replicated balanced block design. Here the balance of a block design is defined in terms of the matrix M₀ introduced by CALI?SKI (1971).     

Abundance trends of American martens in Michigan based on statistical population reconstruction

Estimating the dynamics of furbearer populations is challenging because their elusive behavior and low densities make observations difficult. Statistical population reconstruction is a flexible approach to demographic assessment for harvested populations, but the technique has not been applied to furbearers. We extended this approach to furbearers and analyzed 8 yr of age-at-harvest data for American marten (Martes americana) in the Upper Peninsula of Michigan. Marten abundance estimates showed a general downward trend from an estimate of = 1,733.3 animals in 2000 to = 1,163.9 in 2007. The harvest probability of martens increased nearly 5-fold from 0.0542 in 2000 to 0.2637 in 2007, which corresponded to a 5-fold increase in trap-nights. Continued monitoring of martens in the Upper Peninsula, Michigan, and a reassessment of current harvest regulations are necessary given the estimated decreases. Moreover, we do not encourage the use of harvest indices as the sole technique to assess the status and trends of marten and fisher populations. Auxiliary studies in the Upper Peninsula, Michigan, will allow for continued use and improvement in the application of these models. © 2011 The Wildlife Society.     

Kinetics of ethidium's intercalation in packaged bacteriophage T7 DNA: effects of DNA packing density

The kinetics of ethidium's intercalative binding to DNA packaged in bacteriophage T7 and two T7 deletion mutants have been determined, using enhancement of fluorescence to quantitate binding. At a constant ethidium concentration, the results can be described as first-order binding with two different rate constants, k (= k₁ + k_?1) and k (= k₂ + k_?2). The larger rate constant (k) was at least four orders of magnitude smaller than the comparable first-order forward rate constant for binding to DNA released from its capsid. At 25°C values of k decreased as the amount of DNA packaged per internal volume increased. This latter observation indicates that the rate of ethidium's binding to packaged T7 DNA is limited by an event that occurs inside of the DNA-containing region of T7, not by the crossing of T7 capsid's outer shell. Arrhenius plots of kM are biphasic, indicating a transition for packaged DNA at a temperature of 20°C. The data indicate that k s are limited by either sieving of ethidium during its passage through the packaged DNA or subsequent hindered intercalation.     

Turgor and osmotic relations of the desert shrub Larrea tridentata

Abstract Leaf water relations characteristics of creosote bush, Larrea tridentata, were studied in view of previous reports that its leaves commonly experience zero or negative turgor under dry conditions. Leaf turgor loss point () was determined by a pressure-volume method for samples subjected to a hydration procedure and for untreated samples. Hydration caused to increase by as much as 3 M Pa. Hydration of samples also caused changes in other leaf water relations characteristics such as symplastic solute content, tissue elasticity and symplasmic water fraction, but total leaf solute content was unchanged. Comparison of our field plant water potential data with values of obtained by the two methods resulted in predictions of turgor loss during part or all of a diurnal cycle based on hydrated samples, and turgor maintenance (at least 0.3 MPa) based on untreated samples. Pooled data for obtained from both partially hydrated and untreated samples showed that L. tridentata maintains fairly constant levels of turgor over a wide range of leaf water potential. Dilution of cell contents by apoplastic water introduced significant errors in psychrometric determinations of osmotic potential in both frozen and thawed leaf tissue and expressed cell sap. Use of these values of osmotic potential resulted in predictions of zero turgor at all plant water potentials measured in the field.     

MATERNAL INHERITANCE AND ITS EFFECT ON ADAPTIVE EVOLUTION: A QUANTITATIVE GENETIC ANALYSIS OF MATERNAL EFFECTS IN A NATURAL PLANT POPULATION

A mother can influence a trait in her offspring both by the genes she transmits (Mendelian inheritance) and by maternal attributes that directly affect that trait in her offspring (maternal inheritance). Maternal inheritance can alter the direction, rate, and duration of adaptive evolution from standard Mendelian models and its impact on adaptive evolution is virtually unexplored in natural populations. In a hierarchical quantitative genetic analysis to determine the magnitude and structure of maternal inheritance in the winter annual plant, Collinsia verna, I consider three potential models of inheritance. These range from a standard Mendelian model estimating only direct (i.e., Mendelian) additive and environmental variance components to a maternal inheritance model estimating six additive and environmental variance components: direct additive and environmental variances; maternal additive and environmental variances; and the direct-maternal additive () and environmental covariances. The structure of maternal inheritance differs among the 10 traits considered at four stages in the life cycle. Early in the life cycle, seed weight and embryo weight display substantial , a negative , and a positive . Subsequently, cotyledon diameter displays and of roughly the same magnitude and negative . For fall rosettes, leaf number and length are best described by a Mendelian model. In the spring, leaf length displays maternal inheritance with significant and and a negative . All maternally inherited traits show significant negative . Predicted response to selection under maternal inheritance depends on and as well as . Negative results in predicted responses in the opposite direction to selection for seed weight and embryo weight and predicted responses near zero for all subsequent maternally inherited traits. Maternal inheritance persists through the life cycle of this annual plant for a number of size-related traits and will alter the direction and rate of evolutionary response in this population.     

Characterization of the transition state of Lysozyme unfolding. I. Effect of protein-solvent interactions on the transition state

The influence of proline cis-trans isomerization on the kinetics of lysozyme unfolding was examined carefully according to the theory of Hagerman and Baldwin [(1976) Biochemistry 15, 1462–1473]. As a result, the kinetics of lysozyme unfolding was found to follow the two-state transition model well. The temperature dependencies of k_uf and k_f over a wide temperature range showed that ΔC = 0 and ΔC = ?6.7 kJ K^?1 mol^?1 in solutions of different concentrations of GuHCl. The data observed in solutions containing other denaturants also supported the conclusion that ΔC is nearly equal to zero. The activation enthalpies of unfolding (ΔH) were observed at various concentrations of several kinds of denaturants. They were independent of species and concentrations of denaturants ΔH = 200 kJ mol^?1). These facts indicate that the aspect of interaction between protein and different kinds of solvent molecules varies only slightly during the unfolding to the transition state, that is, the transition state is at compact as the native one. Therefore, it is also suggested that ΔH of 200 kJ mol^?1 is primarily required for the disruption of long-range interactions among different structural domains through a subtle conformational change. We compared the effects of several kinds of denaturants on the unfolding rate. The addition of PrOH more remarkably increases the unfolding rate than do other hydrophilic denaturants. This is probably because PrOH molecules can penetrate into the hydrophobic core of lysozyme, but hydrophilic reagents cannot because of the compactness of the transition state.     

Heat capacity changes and partial molal heat capacities of some di- and tripeptides in water

Integral enthalpies of solution of several dipeptides and tripeptides in water at low concentrations have been determined at 25 and 35°C. These data have been used to derive the changes in heat capacity on dissolution at infinite dilution ΔC at 30°C. Limiting partial molal heat capacities ΔC have been determined by combining ΔC with C_p2 (heat capacity of pure solid peptides). Using the data on ω-amino acids and these peptides, the partial molal heat capacity of a peptide group ? CONH? was semiquantitatively estimated.     

Wolf Use of Summer Territory in Northeastern Minnesota

ABSTRACT Movements of wolves (Canis lupus) during summer 2003 and 2004 in the Superior National Forest were based around homesites but included extensive use of territories. Away from homesites, wolves used different areas daily, exhibiting rotational use. Mean daily range overlap was 22% (SE = 0.02) and that of breeding wolves was significantly greater than for nonbreeders ( = 25% and 16%, respectively). Rotational use may improve hunting success. Managers seeking to remove entire packs must maintain control long enough to ensure that all pack members are targeted.     

On the blue color of triiodide ions in starch and starch fractions. I. Characterization and assignment of absorption and circular dichroism spectra of triiodide ions in amylose

Four fundamental Raman lines were observed at 159, 111, 55 and 27 cm^-1 corresponding to the I bound (I) in amyloses with DP from 20 to 100, regardless of the degree of polymerization of I and the excitation wavelength. The spectral resolution was based on the molar extinction coefficient and molar ellipticity spectra of I. Eight bands, named, S₁, S₂, ?, S₈ from long to short wavelength, were isolated. These were found regardless of the DP. By a resonance excitation Raman study, the characteristics of S₃ and S₄, comprising the shoulder around 480 nm, were found to be different from those of S₁ and S₂, comprising the blue band. The assignment of the spectra was based on the electronic states of the monomeric I in the exciton-coupled dimeric unit. It was concluded that the blue band (S₁,S₂) belonged to the long-axis transitions and the shoulder band (S₃,S₄) to the short-axis ones on the monmeric coordinate system.