bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the effects of conductivity on zone overlap with EMMA: Computer simulation and experiment
Authors: Stahl John W. , Catherman Adam D. , Sampath Ranasinghe K. , Seneviratne C. Aravinda , Strein Timothy G.
Published: May 2011

In this paper, we demonstrate, using both experiment and simulation, how sample zone conductivity can affect plug–plug mixing in small molecule applications of electrophoretically mediated microanalysis (EMMA). The effectiveness of in‐line mixing, which is driven by potential, can vary widely with experimental conditions. Using two small molecule systems, the effects of local conductivity differences between analyte plugs, reagent plugs and the BGE on EMMA analyses are examined. Simul 5.0, a dynamic simulation program for CE systems, is used to understand the ionic boundaries and profiles that give rise to the experimentally obtained data for EMMA analyses for (i) creatinine determination via the Jaffe reaction, a reaction involving a neutral and an anion, and (ii) the redox reaction between gallate and 2,6‐dichloroindophenol, two anions. Low sample conductivity, which is widely used in CE analyses, can be detrimental for in‐line reactions involving a neutral reactant, as rapid migration of the ionic component across a low conductivity neutral zone results in poor reagent plug overlap and low reaction efficiency. Conversely, with two similarly charged reagents, a low conductivity sample plug is advantageous, as it allows field‐amplified stacking of the reagents into a tight reaction zone. In addition, the complexity of simultaneously overlapping three reagent zones is considered, and experimental results validate the predictions made by the simulation. The simulations, however, do not appear to predict all of the observed experimental behavior. Overall, by combining experiment with simulation, an enhanced appreciation for the local field effects in EMMA is realized, and general guidelines for an advantageous sample matrix can be established for categories of EMMA analyses.
Metabolic profiling of pteridines for determination of potential biomarkers in cancer diseases
Authors: Kośliński Piotr , Bujak Renata , Daghir Emilia , Markuszewski Michał J.
Published: May 2011

Cancer disease is the second leading cause of death in the world. Epidemiology data indicate that early diagnosis of a tumour increases a patient's chance of recovery. Biomarkers are effective instruments which can potentially lead to precancer screening or precancer diagnosis and may provide useful information on the cancer type and the disease's stage of progression. The analysis of new biomarkers for cancer is currently a popular area of study in clinical and cancer research. Pteridines are a class of potential cancer biomarkers. The monitoring levels of pteridines may have prospective value for controlling the course of the malignant process. This review describes the functional employment of pteridines, as biomarkers, in cancer diagnosis. It also contains the description of application of analytical techniques such as high‐performance liquid chromatography (HPLC) and capillary electrophoresis (CE) used for pteridine analysis.
Large‐volume sample on‐line concentration of angiotensins in non‐aqueous capillary electrophoresis
Authors: Kitagawa Shinya , Noji Akitsugu , Matsushita Naofumi , Nakagawa Hiroyuki , Asai Takahiro , Ohitani Hajime
Published: May 2011

A single step on‐line concentration and separation method for peptides in non‐aqueous capillary electrophoresis was developed. ACN containing 50 mM tetraethylammonium perchlorate was used as the electrophoretic medium; angiotensins I–IV were separated as a result of the differences in the magnitudes of their interactions with perchlorate anions. When the sample solution (ACN containing 0.5% trifluoroacetic acid and angiotensins) was injected as a large‐volume plug, the analytes were concentrated at the inlet end of the capillary by both sweeping and stacking mechanisms; the separation procedure then started automatically without any operations such as polarity change. It was found that the concentration of analytes, injection period, and concentration of tetraethylammonium perchlorate in the electrophoretic medium were important factors for both separation and concentration efficiencies. The angiotensins were concentrated and separated with the large‐volume injection of up to 80% of the effective capillary length.
Optimizing protein recovery yield from serum samples treated with beads technology
Authors: Bellei Elisa , Monari Emanuela , Bergamini Stefania , Ozben Tomris , Tomasi Aldo
Published: May 2011

Proteomics studies are often complicated by the wide dynamic range of the biological fluids, in which few highly abundant proteins obscure the signal of low abundant ones. To overcome this problem, several techniques have been developed on the basis of “depletion principles,” namely immuno‐subtraction with specific antibodies against the most‐abundant proteins. Unfortunately, the probability of codepletion is a noteworthy drawback associated with these strategies. The ProteoMiner™ (PM) technology is a novel approach, consisting of a combinatorial library of hexapeptide ligands coupled to beads, that allows the capture of all species present in a proteome, but at much reduced protein concentration differences, simultaneously enhancing the concentration of the most dilute species. In this study, we evaluated the compatibility of the PM kit's elution reagent with 2‐DE analysis, comparing five different purification methods on serum samples eluted from the beads: the “ReadyPrep 2‐D Clean‐up kit” and precipitation with organic solvents, as acetone/methanol, TCA/acetone, ACN, and chloroform/methanol. Considering protein recovery yield (quantity) and 2‐DE spot pattern (quality), precipitation with ACN offered the most promising approach, showing the best spot resolution in all regions of the pH gradient and the greatest number of protein spots visualized on 2‐D gels.
Cave digitabula!
Authors: Françoise Lasne , Laurent Martin , Jean‐Antoine Martin
Published: May 2011

We report here observations clearly demonstrating that gloves can have a deleterious impact on an IEF experiment. These observations were made during the practice of analyses for anti‐doping control of erythropoietin. We show that the wearing of nitrile gloves to apply the catholyte strip onto the IEF gel may be responsible for dramatic distortions in the pattern of this hormone. These observations point out that gloves must not be considered only as protective items but also as possible factors in an analytic process.
Important electromigration effects of carbon dioxide in capillary electrophoresis at high pH
Authors: Malá Zdena , Gebauer Petr , Boček Petr
Published: May 2011

This paper deals with unwanted effects of carbonate in capillary zone electrophoretic analyses of anions in alkaline BGEs with indirect UV absorption and conductivity detection. Computer simulations and experimental study of selected model systems have shown that carbon dioxide absorbed from air into BGEs and samples induce important electrophoretic effects like formation of new additional zones and/or boundaries that may further induce strong and pronounced temporary changes in the migration of analytes. Examples are reduction of the pH of alkaline BGEs around pH 11 by up to 1 unit or formation of a pronounced detectable carbon dioxide peak comparable with peaks of analytes at 1 mM level. The higher the pH of the BGE, the stronger these effects and the broader their spectrum, involving (i) changes of effective mobilities and selectivity due to changes in pH of the BGE, (ii) occurrence of additional system zones appearing in form of peaks, dips or more complex disturbances in the detection signal, (iii) temporary interactions with the sample components and subsequent modification of the separation process and of its result. This paper reveals all these effects and brings the knowledge necessary to prevent problems with qualitative and quantitative evaluation of the analysis results.
A novel hybrid mode of sample injection to enhance CZE sensitivity for simultaneous determination of a pyridine‐triphenylborane anti‐fouling agent and its degradation products
Authors: Kaewchuay Netnapit , Yakushiji Yuki , Fukushi Keiichi , Saito Keiitsu , Hirokawa Takeshi
Published: May 2011

We developed a novel hybrid sample injection mode (HSIM) that presents the combination of electrokinetic injection and vacuum injection to enhance detection sensitivity in CZE. Samples were introduced using both vacuum and electrokinetic injections simultaneously, with a water plug injected into the capillary prior to sample introduction (i.e. similarly to field‐amplified sample injection, FASI). Using a sample mixture containing an anti‐fouling agent applied to ship hulls, pyridine‐triphenylborane and its degradation products (diphenylborinic acid, phenylboronic acid, and phenol) dissolved in ACN, the length of water plug, time, and voltage for sample introduction were optimized. The signal intensity (peak height) was found to be up to a 30‐fold increased using HSIM by applying 4 kV for 4 s at the inlet end of the capillary as the cathode with supplementary vacuum in comparison with only vacuum injection for 4 s. The LODs (at a S/N of 3) for pyridine‐triphenylborane, diphenylborinic acid, phenylboronic acid, and phenol were 0.88, 1.0, 21, and 23 μg/L, respectively. At the level of 0.04 mg/L, the RSDs (n=4, intra‐day) for the above analytes were in the ranges of 1.9–11, 4.3–9.2, and 0.34–0.66% for peak area, peak height, and migration time, respectively. The HSIM is a simple and promising procedure useful for enhancing the sensitivity for both low‐and high‐mobility ions in CZE.
Prior elicitation for mixed quantile regression with an allometric model
Authors: Alhamzawi Rahim , Yu Keming , Vinciotti Veronica , Tucker Allan
Published: May 2011

In this paper, we introduced methods for conducting Bayesian quantile analysis of an allometric model that included random effects, with the primary goal of estimating quantiles of the length‐weight relationship of fish data. We developed prior elicitation schemes to incorporate historical information into the analysis of current data. We proposed Gibbs sampler methods to facilitate Bayesian computation and provided detailed implementation schemes. We applied our methods to analyze data of walleye Sander vitreus and white bass Morone chrysops in Lake McConaughy, Nebraska. Copyright © 2011 John Wiley & Sons, Ltd.
Finite element‐fictitious boundary methods (FEM‐FBM) for 3D particulate flow
Authors: Münster R. , Mierka O. , Turek S.
Published: May 2011

In this paper we discuss numerical simulation techniques using a finite element approach in combination with the fictitious boundary method (FBM) for rigid particulate flow configurations in 3D. The flow is computed with a multigrid finite element solver (FEATFLOW), the solid particles are allowed to move freely through the computational mesh which can be static or adaptively aligned by a grid deformation method allowing structured as well as unstructured meshes. We explain the details of how we can use the FBM to simulate flows with complex geometries that are hard to describe analytically. Stationary and time‐dependent numerical examples, demonstrating the use of such geometries are provided. Our numerical results include well‐known benchmark configurations showing that the method can accurately and efficiently handle prototypical particulate flow situations in 3D with particles of different shape and size. Copyright © 2011 John Wiley & Sons, Ltd.
Adaptive non‐conformal mesh refinement and extended finite element method for viscous flow inside complex moving geometries
Authors: Sarhangi Fard A. , Hulsen M. A. , Meijer H. E. H. , Famili N. M. H. , Anderson P. D.
Published: May 2011

Two different techniques to analyze non‐Newtonian viscous flow in complex geometries with internal moving parts and narrow gaps are compared. The first technique is a non‐conforming mesh refinement approach based on the fictitious domain method (FDM), and the second one is the extended finite element method (XFEM). The refinement technique uses one fixed reference mesh, and to impose continuity across non‐conforming regions, constraints using Lagrangian multipliers are used. The size of elements locally in the high shear rate regions is reduced to increase accuracy. FDM is shown to have limitations; therefore, XFEM is applied to decouple the fluid from the internal moving rigid bodies. In XFEM, the discontinuous field variables are captured by using virtual degrees of freedom that serve as enrichment and by applying special integration over the intersected elements. The accuracy of the two methods is demonstrated by direct comparison with results of a boundary‐fitted mesh applied to a two‐dimensional cross section of a twin‐screw extruder. Compared with non‐conforming FDM, XFEM shows a considerable improvement in accuracy around the rigid body, especially in the narrow gap regions. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of splicing mutations on NF2‐transcripts: Transcript analysis and information theoretic predictions
Authors: Ellis James R. , Heinrich Bianca , Mautner Victor‐F. , Kluwe Lan
Published: May 2011

This study examined the effects of 22 putative splicing mutations in the NF2 gene by means of transcript analysis and information theory based prediction. Fourteen mutations were within the dinucleotide acceptor and donor regions, often referred to as (AG/GT) sequences. Six were outside these dinucleotide regions but within the more broadly defined splicing regions used in the information theory based model. Two others were in introns and outside the broadly defined regions. Transcript analysis revealed exon skipping or activation of one or more cryptic splicing sites for 17 mutations. No alterations were found for the two intronic mutations and for three mutations in the broadly defined splicing regions. Concordance and partial concordance between the calculated predictions and the results of transcript analysis were found for 14 and 6 mutations, respectively. For two mutations, the predicted alteration was not found in the transcripts. Our results demonstrate that the effects of splicing mutations in NF2 are often complex and that information theory based analysis is helpful in elucidating the consequences of these mutations. © 2011 Wiley‐Liss, Inc.
13q14 Deletion size and number of deleted cells both influence prognosis in chronic lymphocytic leukemia
Authors: Dal Bo Michele , Rossi Francesca Maria , Rossi Davide , Deambrogi Clara , Bertoni Francesco , Del Giudice Ilaria , Palumbo Giuseppe , Nanni Mauro , Rinaldi Andrea , Kwee Ivo , Tissino Erika , Corradini Giorgia , Gozzetti Alessandro , Cencini Emanuele , Ladetto Marco , Coletta Angela Maria , Luciano Fabrizio , Bulian Pietro , Pozzato Gabriele , Laurenti Luca , Forconi Francesco , Di Raimondo Francesco , Marasca Roberto , Del Poeta Giovanni , Gaidano Gianluca , Foà Robin , Guarini Anna , Gattei Valter
Published: May 2011

Deletion at 13q14 is detected by fluorescence in situ hybridization (FISH) in about 50% of chronic lymphocytic leukemia (CLL). Although CLL with 13q deletion as the sole cytogenetic abnormality (del13q‐only) usually have good prognosis, more aggressive clinical courses are documented for del13q‐only CLL carrying higher percentages of 13q deleted nuclei. Moreover, deletion at 13q of different sizes have been described, whose prognostic significance is still unknown. In a multi‐institutional cohort of 342 del13q‐only cases and in a consecutive unselected cohort of 265 CLL, we investigated the prognostic significance of 13q deletion, using the 13q FISH probes locus‐specific identifier (LSI)‐D13S319 and LSI‐RB1 that detect the DLEU2/MIR15A/MIR16‐1 and RB1 loci, respectively. Results indicated that both percentage of deleted nuclei and presence of larger deletions involving the RB1 locus cooperated to refine the prognosis of del13q‐only cases. In particular, CLL carrying <70% of 13q deleted nuclei with deletions not comprising the RB1 locus were characterized by particularly long time‐to‐treatment. Conversely, CLL with 13q deletion in <70% of nuclei but involving the RB1 locus, or CLL carrying 13q deletion in ≥70% of nuclei, with or without RB1 deletions, collectively experienced shorter time‐to‐treatment. A revised flowchart for the prognostic FISH assessment of del13q‐only CLL, implying the usage of both 13q probes, is proposed. © 2011 Wiley‐Liss, Inc.
Plasma homocysteine, brain imaging and cognition in older patients with mental illness
Authors: Nilsson Karin , Gustafson Lars , Hultberg Björn
Published: May 2011

Background

Total plasma homocysteine (tHcy) concentration is elevated in older patients with mental illness, and patients with vascular disease have higher plasma tHcy concentration than patients without vascular disease. Plasma tHcy has been reported to be associated with cognitive functions. The mechanism by which plasma tHcy may influence cognitive functions is not clear.

Method

We have investigated the relation between plasma tHcy, brain imaging findings (computer tomography scan [CT]) and cognition, measured as Mini mental state examination (MMSE), in 395 consecutively enrolled older patients with mental illness.

Results

Age and plasma tHcy were significant predictors of MMSE score, whereas pathological CT findings, indicating cerebrovascular disease, showed no prediction of MMSE score.

Conclusion

The relation between plasma tHcy and cognition is not mediated by cerebrovascular disease as evaluated by pathological CT findings. Copyright © 2011 John Wiley & Sons, Ltd.
Reducing monitoring gaps at the aquifer–river interface by modelling groundwater–surface water exchange flow patterns
Authors: Munz Matthias , Krause Stefan , Tecklenburg Christina , Binley Andrew
Published: May 2011

This study investigates spatial patterns and temporal dynamics of aquifer–river exchange flow at a reach of the River Leith, UK. Observations of sub‐channel vertical hydraulic gradients at the field site indicate the dominance of groundwater up‐welling into the river and the absence of groundwater recharge from surface water. However, observed hydraulic heads do not provide information on potential surface water infiltration into the top 0–15 cm of the streambed as these depths are not covered by the existing experimental infrastructure. In order to evaluate whether surface water infiltration is likely to occur outside the ‘window of detection’, i.e. the shallow streambed, a numerical groundwater model is used to simulate hydrological exchanges between the aquifer and the river. Transient simulations of the successfully validated model (Nash and Sutcliff efficiency of 0·91) suggest that surface water infiltration is marginal and that the possibility of significant volumes of surface water infiltrating into non‐monitored shallow streambed sediments can be excluded for the simulation period. Furthermore, the simulation results show that with increasing head differences between river and aquifer towards the end of the simulation period, the impact of streambed topography and hydraulic conductivity on spatial patterns of exchange flow rates decreases. A set of peak flow scenarios with altered groundwater‐surface water head gradients is simulated in order to quantify the potential for surface water infiltration during characteristic winter flow conditions following the observation period. The results indicate that, particularly at the beginning of peak flow conditions, head gradients are likely to cause substantial increase in surface water infiltration into the streambed. The study highlights the potential for the improvement of process understanding of hyporheic exchange flow patterns at the stream reach scale by simulating aquifer‐river exchange fluxes with a standard numerical groundwater model and a simple but robust model structure and parameterization. Copyright © 2011 John Wiley & Sons, Ltd.
Pentapeptide‐modified poly(N,N‐diethylacrylamide) hydrogel scaffolds for tissue engineering
Authors: Horák Daniel , Matulka Kamil , Hlídková Helena , Lapčíková Monika , Beneš Milan J. , Jaroš Josef , Hampl Aleš , Dvořák Petr
Published: May 2011

Poly(N,N‐diethylacrylamide) (PDEAAm) hydrogel scaffolds were prepared by radical copolymerization of N,N‐diethylacrylamide (DEAAm), N,N′‐methylenebisacrylamide and methacrylic acid in the presence of (NH4)2SO4 or NaCl. The hydrogels were characterized by low‐vacuum scanning electron microscopy in the water‐swollen state, water and cyclohexane regain, and by mercury porosimetry. The pentapeptide, YIGSR‐NH2, was immobilized on the hydrogel. Human embryonic stem cells (hESCs) were cultured with the hydrogels to test their biocompatibility. The results suggest that the PDEAAm hydrogel scaffolds are nontoxic and support hESC attachment and proliferation, and that interconnected pores of the scaffolds are important for hESC cultivation. Immobilization of YIGSR‐NH2 pentapeptide on the PDEAAm surface improved both adhesion and growth of hESCs compared with the unmodified hydrogel. The YIGSR‐NH2‐modified PDEAAm hydrogels may be a useful tool for tissue‐engineering purposes. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Synthesis and characterization of high‐quality skin‐cooling sheets containing thermosensitive poly(N‐isopropylacrylamid)
Authors: Takegami Yoshiaki , Yokoyama Yoshiyuki , Norisugi Osamu , Nagatsuma Masahiro , Takata Koji , Rehman Mati Ur , Matsunaga Kenji , Yokoi Hideharu , Fujiki Satoshi , Makino Teruhiko , Shimizu Tadamichi
Published: May 2011

Poly(N‐isopropylacrylamide) (PNIPAAm) is the most popular thermosensitive polymer, and exhibits a low critical solution temperature of approximately 32°C. This study aimed to examine the usefulness of new cooling sheets, which are manufactured using a thermosensitive poly(N‐isopropylacrylamide) (PNIPAAm) material. We prepared cooling‐hydrogel sheets containing PNIPAAm (PNIPAAm sheet). We measured the skin temperature on the arms of the subjects using a thermograph and compared the usefulness of the PNIPAAm sheet and a control cooling‐hydrogel sheet that did not contain the PNIPAAm mixture. Thermographic measurements obtained 40 min after the treatment with the cooling sheets showed the skin temperature of the subjects treated with the 3.% (w/w) PNIPAAm sheets to be significantly lower than that of the subjects treated with the control cooling‐hydrogel sheet (p < 0.005). Compared with the control sheet, the cooling effect of the new PNIPAAm sheet also persisted for a longer duration (up to 100 min). The PNIPAAm sheets exhibited excellent cooling effects. This sheet may therefore be useful for lowering the body temperature of patients with high‐grade fever, such as fever due to influenza infection. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Is 4‐nitrobenzenethiol converted to p,p′‐dimercaptoazobenzene or 4‐aminothiophenol by surface photochemistry reaction?
Authors: Dong Bin , Fang Yurui , Xia Lixin , Xu Hongxing , Sun Mengtao
Published: May 2011

For the first time, the experimental and theoretical evidence for the conversion of 4‐nitrobenzenethiol (4‐NBT) to p,p′‐dimercaptoazobenzene (DMAB) in Ag and Cu sols by surface photochemistry reaction is obtained with surface‐enhanced Raman scattering (SERS) spectroscopy. The SERS spectrum of 4‐NBT in Cu sol is identical to that of DMAB produced from 4‐aminothiophenol in Ag sol as reported in recent literature, thereby providing direct spectral evidence. Copyright © 2011 John Wiley & Sons, Ltd.
Raman spectroscopic identification of fullerene inclusions in polymer/fullerene blends
Authors: Falke Sarah , Eravuchira Pinkie , Materny Arnulf , Lienau Christoph
Published: May 2011

Thin films of the conjugated polymer poly(3‐hexylthiophene) (P3HT) and blends of the soluble fullerene derivative[6,6]‐phenyl C61‐butyric acid methyl ester (PCBM) with P3HT—a well studied but not completely understood donor–acceptor system for organic solar cells—have been studied by means of UV–visible absorption and resonant Raman spectroscopy. Additionally, we have employed atomic force microscopy phase imaging to characterize the nanomorphology of the P3HT : PCBM thin film, revealing a close intermixing of two phases with domain sizes ranging from a few to several tens of nanometers. A systematic analysis of pristine polymer and blend Raman spectra provides evidence that features attributable to PCBM, possibly even depending on the charge state of the fullerene molecule, can be observed. Hence our results suggest that fullerene inclusions in polymer/fullerene blends can be identified via Raman spectroscopy. Copyright © 2011 John Wiley & Sons, Ltd.
Elk parturition site selection at local and landscape scales
Authors: Barbknecht Andrea E. , Fairbanks W. Sue , Rogerson Jared D. , Maichak Eric J. , Scurlock Brandon M. , Meadows Laura L.
Published: May 2011

Selection of habitat components by ungulates associated with parturition sites varies among and within species depending upon vulnerability to predators, variation in local topography and climate regimes, and the length of time that the maternal–neonatal unit spends at or near the parturition location. We marked 169 parturition locations of elk (Cervus elaphus nelsoni) in western Wyoming using vaginal implant transmitters and evaluated parturition‐specific habitat selection at macro‐ and microhabitat scales using a resource selection function modeling approach. Elk calved in a variety of habitats, yet demonstrated selection at both spatial scales. We found the strongest support for models that incorporated multiple habitat features and focused on topographical and vegetative cover types that provide physical and thermal cover at the macrohabitat scale and for visual cover models at the microhabitat scale. Models based solely on forage availability or quality were least supported at both scales, which may be indicative of a brief occupation of the parturition location or low heterogeneity in the availability of forage resources on parturition ranges. Results of early elk natural history studies may have represented a bias introduced by variable sightability and accessibility of females with calves and a lack of differentiation between calving and neonatal periods. More clearly defining calving site selection and removing biases toward more open habitats where sightability of neonates is greater may be used by wildlife or land managers to improve or protect calving habitats, which is often a stated objective of management actions. The results of this study suggest that microhabitat is more important to elk and that temporal closures over broad areas versus closures focused on specific macrohabitats may be more effective in protecting calving animals. © 2011 The Wildlife Society.
Temporal change in the morphometry–body mass relationship of polar bears
Authors: Thiemann Gregory W. , Lunn Nicholas J. , Richardson Evan S. , Andriashek Dennis S.
Published: May 2011

Accurate information on animal body mass is often an essential component of wildlife research and management. However, for many large‐bodied species, obtaining direct scale weights from individuals may be difficult. In these cases, morphometric equations (e.g., based on girth or length) may provide accurate and precise estimates of body mass. We developed predictive equations to estimate the body mass of free‐ranging polar bears (Ursus maritimus) in western Hudson Bay, Canada. Using multiple linear and non‐linear regression, we identified a strong relationship between polar bear body weight and linear measures of straight line length and axillary girth. The mass–morphometry relationship appeared to change over time and we developed separate equations for polar bears measured during 2 time periods, 1980–1996 and 2007–2009. Non‐linear models were more accurate and provided body mass estimates within 5.8% (R2 = 0.98) and 6.1% (R2 = 0.98) of scale weight in the earlier and later time periods, respectively. Earlier equations developed for polar bears in this subpopulation performed poorly when applied to recently sampled individuals. In contrast, some contemporary equations from other regions performed reasonably well, suggesting that temporal changes within a subpopulation may be more pronounced than regional differences and can render earlier predictive equations obsolete. Our results have important implications for current and future studies of polar bear body condition and the effects of ongoing climate warming. © 2011 The Wildlife Society.
Estimating occupancy to monitor northern goshawk in the central Rocky Mountains
Authors: Beck Jeffrey L. , Skorkowsky Robert C. , Hayward Gregory D.
Published: May 2011

Designing monitoring programs to evaluate trends in low‐density wildlife species at regional scales is challenging given difficulties detecting uncommon organisms distributed in potential habitats over large spatial extents. The northern goshawk (Accipiter gentilis) has been petitioned for listing under the Endangered Species Act and the review of the petition indicated a need for information on population trend. To evaluate trends in goshawk populations, the U.S. Forest Service developed the Northern Goshawk Bioregional Monitoring Design to estimate goshawk occupancy over broad spatial extents. We adapted and implemented this design to approximately 30,600 km2 of 88,128 km2 of National Forest System lands in the Forest Service Rocky Mountain Region, including portions of Colorado, Wyoming, and South Dakota. We developed a stratified random design to monitor goshawk occupancy in sampling units, defined by primary and secondary habitat quality as well as accessibility. To define habitat quality, we examined a time series for 58 previously located nesting territories. Using logistic regression, we found that the dominant conifer species and status of aspen in postfledging zones best characterized high‐quality goshawk nesting habitat. We applied model results to stratify 4,445 sampling units based on habitat quality and further stratified sampling units based on accessibility into easy and difficult access categories. We conducted field sampling during the goshawk breeding season in the summer of 2006 to estimate detection probabilities and occupancy rates. Within our sampling frame, we sampled 51 sampling units and estimated goshawk occupancy of 0.329 (95% CI: 0.213–0.445). Occupancy within primary strata (high quality) sampling units was 0.811 (SE = 0.113), whereas occupancy in secondary strata (lower quality) sampling units was 0.124 (SE = 0.067). Future implementation of this monitoring program can achieve 0.8 power to detect 30–40% declines in with 140 sampling units. Our implementation of a stratified sampling design to monitor occupancy of goshawks at a region‐wide scale reduced the number of sampling units in each administrative unit and focused our efforts on those areas most likely to have goshawks. © 2011 The Wildlife Society.
Effects of supplemental feeding and density of white‐tailed deer on rodents
Authors: Moseley William A. , Cooper Susan M. , Hewitt David G. , Fulbright Timothy E. , Deyoung Charles A.
Published: May 2011

Spatial distribution, population density, and reproductive success of many wildlife species may be altered by changes in vegetation composition, habitat structure, and availability of food. Altered distributions of key herbivores such as white‐tailed deer (Odocoileus virginianus) may impact all of these factors. Our objective was to determine the direct and indirect effects of supplemental feeding of deer on rodent populations in south Texas. We modeled effects of supplemental feeding and habitat change due to deer browsing through surveys of rodents. Rodents have a short generation time and populations respond quickly to change, so they are a suitable indicator of changes in habitat structure brought about by deer browsing pressure. We sampled rodent populations near to and far from deer feeders within twelve 81‐ha enclosures containing three different densities of deer with and without supplemental feed. The three deer densities were low (8.1 ha/deer), medium (3.2 ha/deer), and high (2 ha/deer). We conducted rodent trapping during March and April of 2007 and 2008. Abundance of rodents was much higher (P < 0.001) in 2008 than in the previous year due to an increase in rainfall. However, we found little effect of deer density, supplemental feeding of deer, or distance from deer feeders on rodent populations. Thus we conclude that supplemental feeding of deer and deer density had little influence on rodent communities in this environment. Rodent species native to semi‐arid environments are probably adapted to large changes in vegetative productivity brought about by the highly variable annual rainfall patterns, therefore they can adapt to the less abrupt habitat changes resulting from changing densities of deer. Conservation concerns that providing supplemental feed to deer in semi‐arid rangeland will disrupt the ecology of the land through changes in rodent populations were not supported. © 2011 The Wildlife Society.
Efficiency of time‐lapse intervals and simple baits for camera surveys of wild pigs
Authors: Williams Brian L. , Holtfreter Robert W. , Ditchkoff Stephen S. , Grand James B.
Published: May 2011

Growing concerns surrounding established and expanding populations of wild pigs (Sus scrofa) have created the need for rapid and accurate surveys of these populations. We conducted surveys of a portion of the wild pig population on Fort Benning, Georgia, to determine if a longer time‐lapse interval than had been previously used in surveys of wild pigs would generate similar detection results. We concurrently examined whether use of soured corn at camera sites affected the time necessary for pigs to locate a new camera site or the time pigs remained at a site. Our results suggest that a 9‐min time‐lapse interval generated dependable detection results for pigs and that soured corn neither attracted pigs to a site any quicker than plain, dry, whole‐kernel corn, nor held them at a site longer. Maximization of time‐lapse interval should decrease data and processing loads, and use of a simple, available bait should decrease cost and effort associated with more complicated baits; combination of these concepts should increase efficiency of wild pig surveys. © 2011 The Wildlife Society.
Grassland birds and rotational‐grazing in the northeast: Breeding ecology, survival and management opportunities
Authors: Perlut Noah G. , Strong Allan M.
Published: May 2011

We studied long‐term (2002–2009) demographics of bobolinks (Dolichonyx oryzivorus) and savannah sparrows (Passerculus sandwichensis) breeding in rotationally grazed systems in the northeastern United States. Both nest success (6–44% bobolink; 7–48% savannah sparrow) and annual productivity (0.43–2.83 bobolink; 0.70–2.35 savannah sparrow) varied annually. Predation (48%) and trampling by cows (32%) accounted for most failed nests. Annual adult apparent survival ranged from 23% to 85% and showed substantial variation by species and sex. Although grazing resulted in substantial loss of vegetative cover, savannah sparrows responded similarly to predation and grazing‐induced nest failure (time to renest, distance moved between nests) and generally remained in the same paddock to renest. Minimum paddock size to accommodate one female within this rotation was 70 m × 70 m (0.49 ha), allowing a female to stay within a paddock and move (approx. 50 m) between nesting attempts. To balance pasturing objectives and birds' needs in paddocks first grazed before 25 June, managers in the Northeast should rest that paddock 42–50 days before the second grazing. © 2011 The Wildlife Society.
Barred owl occupancy surveys within the range of the northern spotted owl
Authors: Wiens J. David , Anthony Robert G. , Forsman Eric D.
Published: May 2011

The range expansion by barred owls (Strix varia) into western North America has raised considerable concern regarding their potential effects on declining northern spotted owl (Strix occidentalis caurina) populations, yet most information on the occurrence of barred owls in the region is limited to incidental detections during surveys for spotted owls. To address this shortcoming we investigated response behavior, detection probabilities, and landscape occupancy patterns of barred owls in western Oregon, USA, during conspecific versus spotted owl call‐broadcast surveys. Subtle differences in barred owl response behavior to conspecific versus spotted owl vocalizations combined with minor procedural differences between species‐specific survey protocols led to a sizeable difference in estimated detection probabilities during conspecific (0.66, 95% CI = 0.61–0.71) versus spotted owl (0.48, 95% CI = 0.39–0.56) surveys. We identified 61 territorial pairs of barred owls during repeated surveys of a multi‐ownership study area with the probability of occupancy being highest in the structurally diverse mixture of mature and old forests that occurred almost entirely on public lands. Our findings suggest that research and management strategies to address potential competitive interactions between spotted owls and barred owls will require carefully designed, species‐specific survey methods that account for erratic response behaviors and imperfect detection of both species. Our sampling methods can be used by forest managers to determine the occurrence and distribution of barred owls with high confidence. © 2011 The Wildlife Society.
Influence of fruit on habitat selection of Asian bears in a tropical forest
Authors: Ngoprasert Dusit , Steinmetz Robert , Reed David H. , Savini Tommaso , Gale George A.
Published: May 2011

Wild bear populations in Southeast Asia are threatened with extinction, but the ecology and distribution of the 2 species occurring in the region's protected areas is poorly known, so there is little scientific basis underlying conservation strategies. We used bear signs, primarily claw marks on climbed trees, to study habitat selection and distribution of Asiatic black bear (Ursus thibetanus) and sun bear (Helarctos malayanus) across Khao Yai National Park, Thailand from March to December 2008. We found black bear claw marks in 24 of 30 random sample blocks (80%), indicating that this species was widely distributed across Khao Yai. Sun bear signs were much scarcer: their claw marks occurred in 11 blocks (37%); data were too sparse for sun bear so we limited our focus to Asiatic black bear. Using logistic regression, we found that fruit abundance best explained variation in presence of black bear, whereas human disturbance, distance to park edge, elevation, and ground cover had little influence. Fruits appear to be a key resource for Asiatic black bears, and factors affecting fruit abundance or shifts in seasonality (e.g., climate change) will impact bear populations. Knowledge of this relationship will allow managers to be more proactive in managing bears. We recommend using sign surveys for monitoring changes in black bear occupancy as they are inexpensive, efficient, and can be conducted by trained park rangers. © 2011 The Wildlife Society.
Seeking parsimony in landscape metrics
Authors: Cunningham Mary Ann , Johnson Douglas H.
Published: May 2011

Numerous metrics describing landscape patterns have been used to explain landscape‐scale habitat selection by birds. The myriad metrics, their complexity, and inconsistent responses to them by birds have led to a lack of clear recommendations for managing land for desired species. The amount of a target land cover type in the landscape (percentage cover) often has been a useful indicator of the likelihood of species occurrence or of habitat selection; is it also a more adequate and parsimonious measure for explaining species distributions than patch size or more complex measures of landscape configuration? We examined responses of 6 woodland‐interior bird species to the percentage tree cover within prescribed areas and to patch size, edge density, and other metrics. We examined responses in 2 landscapes: a mixed woodland‐savanna and an eastern deciduous forest. For these 6 species, percentage tree cover explained bird occurrence as well as or better than other measures in both study areas. We then repeated the analysis on a larger group of woodland species, including those associated with woodland edges. The bird species we studied had varied responses to landscape metrics, but percentage tree cover was the strongest explanatory variable overall. Although percentage cover estimated from remotely sensed data is an inexact representation of habitat in the landscape, it does appear to be reliable and easy to conceptualize, relative to other measures. We suggest that, at least for woodland habitat, percentage cover is a broadly useful measure that can be helpful in pragmatic questions of explaining responses to landscapes or in anticipating responses to landscape change. © 2011 The Wildlife Society.
Decision analysis for conservation breeding: Maximizing production for reintroduction of whooping cranes
Authors: Smith Des H.V. , Converse Sarah J. , Gibson Keith W. , Moehrenschlager Axel , Link William A. , Olsen Glenn H. , Maguire Kelly
Published: May 2011

Captive breeding is key to management of severely endangered species, but maximizing captive production can be challenging because of poor knowledge of species breeding biology and the complexity of evaluating different management options. In the face of uncertainty and complexity, decision‐analytic approaches can be used to identify optimal management options for maximizing captive production. Building decision‐analytic models requires iterations of model conception, data analysis, model building and evaluation, identification of remaining uncertainty, further research and monitoring to reduce uncertainty, and integration of new data into the model. We initiated such a process to maximize captive production of the whooping crane (Grus americana), the world's most endangered crane, which is managed through captive breeding and reintroduction. We collected 15 years of captive breeding data from 3 institutions and used Bayesian analysis and model selection to identify predictors of whooping crane hatching success. The strongest predictor, and that with clear management relevance, was incubation environment. The incubation period of whooping crane eggs is split across two environments: crane nests and artificial incubators. Although artificial incubators are useful for allowing breeding pairs to produce multiple clutches, our results indicate that crane incubation is most effective at promoting hatching success. Hatching probability increased the longer an egg spent in a crane nest, from 40% hatching probability for eggs receiving 1 day of crane incubation to 95% for those receiving 30 days (time incubated in each environment varied independently of total incubation period). Because birds will lay fewer eggs when they are incubating longer, a tradeoff exists between the number of clutches produced and egg hatching probability. We developed a decision‐analytic model that estimated 16 to be the optimal number of days of crane incubation needed to maximize the number of offspring produced. These results show that using decision‐analytic tools to account for uncertainty in captive breeding can improve the rate at which such programs contribute to wildlife reintroductions. © 2011 The Wildlife Society.
Assessing release protocols for Canada lynx reintroduction in colorado
Authors: Devineau Olivier , Shenk Tanya M. , Doherty Paul F. , White Gary C. , Kahn Rick H.
Published: May 2011

Reintroductions are a common strategy to restore ecosystem integrity, especially when top predators are involved. Reintroductions are often time consuming, expensive, and controversial, and thus understanding what aspects are important for a successful program is needed. Focusing on the example of the reintroduction of Canada lynx (Lynx canadensis) to Colorado, we investigated how different release protocols (RP) affected mortality within the first year post‐release. We found that average monthly mortality in the study area during the first year decreased with time in captivity from 0.205 (95% CI = 0.069, 0.475) for lynx having spent up to 7 days in captivity to 0.028 (95% CI = 0.012, 0.064) for lynx spending >45 days in captivity before release. Our results also suggest that keeping lynx in captivity beyond 5–6 weeks accrued little benefit in terms of monthly survival. We found that, on a monthly average basis, lynx were as likely to move out (P = 0.196, SE = 0.032) as well as back onto (P = 0.143, SE = 0.034) the reintroduction area during the first year after release. Mortality was 1.6 times greater outside of the study area, suggesting that permanent emigration and differential mortality rates on and off reintroduction areas should be factored into sample size calculations for an effective reintroduction effort. A post‐release monitoring plan is critical to providing information to assess aspects of RP and to improve survival of individuals. Future lynx and other carnivore reintroductions may use our results to help design reintroduction programs including both the release and post‐release monitoring protocols. © 2011 The Wildlife Society.
Effects of satellite transmitters fitted to breeding Cory's shearwaters
Authors: Villard Pascal , Bonenfant Christophe , Bretagnolle Vincent
Published: May 2011

We studied the effects of a new technique to fix satellite transmitters on the feeding behavior and chick body growth of the Cory's shearwater (Calonectris diomedea). Transmitters did not significantly affect the breeding bird's body mass or diving performance. However, on average, pairs with ≥1 adult equipped with a transmitter brought a lighter meal (54.8 ± 18.9 g) to nestlings than did control birds or the same pair with the transmitter removed (77.4 ± 8.3 g) leading to a decreased chick body growth. However at fledging, chicks in control and treatment groups had similar body mass whether parents were equipped with a PTT or not. Our method of transmitter attachment could therefore be an appropriate alternative for studying the ecology of procellariiforms weighing <1 kg given that birds are fitted with transmitters for <2 weeks and restricted to 1 parent only. © 2011 The Wildlife Society.