bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonal variation in nutritional characteristics of the diet of greater white‐fronted geese
Authors: Ely Craig R. , Raveling Dennis G. 
Published: March 2011

AbstractWe studied diet and habitat use of greater white‐fronted geese (Anser albifrons) from autumn through spring on their primary staging and wintering areas in the Pacific Flyway, 1979–1982. There have been few previous studies of resource use and forage quality of wintering greater white‐fronted geese in North America, and as a consequence there has been little empirical support for management practices pertaining to habitat conservation of this broadly distributed species. Observations of >2,500 flocks of geese and collections of foraging birds revealed seasonal and geographic variation in resource use reflective of changes in habitat availability, selection, and fluctuating physiological demands. Autumn migrants from Alaska arrived first in the Klamath Basin of California and southern Oregon, where they fed on barley, oats, wheat, and potatoes. Geese migrated from the Klamath Basin into the Central Valley of California in late autumn where they exploited agricultural crops rich in soluble carbohydrates, with geese in the Sacramento Valley feeding almost exclusively on rice and birds on the Sacramento–San Joaquin Delta primarily utilizing corn. White‐fronted geese began their northward migration in late winter, and by early spring most had returned to the Klamath Basin where 37% of flocks were found in fields of new growth cultivated and wild grasses. Cereal grains and potatoes ingested by geese were low in protein (7–14%) and high in soluble nutrients (17–47% neutral detergent fiber [NDF]), whereas grasses were low in available energy (47–49% NDF) but high in protein (26–42%). Greater white‐fronted geese are generalist herbivores and can exploit a variety of carbohydrate‐rich cultivated crops, likely making these geese less susceptible to winter food shortages than prior to the agriculturalization of the North American landscape. However, agricultural landscapes can be extremely dynamic and may be less predictable in the long‐term than the historic environments to which geese are adapted. Thus far greater white‐fronted geese have proved resilient to changes in land cover in the Pacific Flyway and by altering their migration regime have even been able to adapt to changes in the availability of suitable forage crops. © 2010 The Wildlife Society.
Factors affecting piping plover hatching success on Long Island, New York
Authors: Doherty Paul J. , Heath Julie A. 
Published: March 2011

AbstractLow hatching success may limit progress towards reaching productivity goals for Atlantic Coast piping plover (Charadrius melodus) recovery, despite management strategies to protect eggs from predators and decrease human disturbance of birds on nests. We measured piping plover hatching success on Eastern Long Island beaches and identified the major causes of egg failure to better understand why eggs that were otherwise intact (not depredated or destroyed by tidal flooding) failed to hatch. We documented egg and nest fates, dissected contents of unhatched eggs to determine viability, and recorded human and predator activity near a subset of plover nests on Suffolk County Parks properties. The low hatching success we recorded (0.60) in 2006 and 2007 would require higher chick survival rates than are typically observed for piping plovers to meet recovery targets for productivity. Few eggs showed signs of poor viability and overall egg hatchability was comparable to other ground nesting birds. Most egg failure was due to either depredation at unexclosed nests or nest abandonment by adults. The best predictor of nest abandonment was the maximum number of red fox tracks (Vulpes vulpes) counted on nearby transects (β = −1.16, 95% CI: −2.0 to −0.3) and we found evidence that plovers abandoned eggs in response to predation risk (e.g., a fox circling a nest exclosure). Adults from abandoned nests may have deserted eggs or been depredated. In either case, intact and viable eggs were abandoned. Nest abandonment was not related to human activity near nests, which were buffered from human disturbance by symbolic string fencing. Our results suggest that depredation and nest abandonment (e.g., desertion or death of adults) due to predator disturbance, not human disturbance or poor egg viability, contributed to the low hatching success we recorded. Active predator removal in addition to modification of predator exclosure use and design may be necessary to prevent direct (egg depredation) and indirect (nest abandonment) negative effects of predators on hatching success. © 2010 The Wildlife Society.
Nest success of northern bobwhite on managed and unmanaged landscapes in southeast Iowa
Authors: Potter Lisa M. , Otis David L. , Bogenschutz Todd R. 
Published: March 2011

AbstractRange‐wide declines in northern bobwhite populations (Colinus virginianus) have been attributed to concomitant loss of breeding habitat. Bobwhite management efforts to restore this habitat resource can be informed by empirical studies of associations between breeding success and multi‐scale habitat attributes. We compared bobwhite nest success in 2 southern Iowa landscapes as a function of microhabitat and landscape composition. Lake Sugema Fish and Wildlife Area (LSWA) was managed to promote bobwhite recruitment, and Harrisburg Township (HT) was an adjacent landscape dominated by private agricultural production. Survival rate modeling based on telemetry data provided evidence for age‐specific daily nest survival rate. Daily survival rates decreased as nest age increased, but the decline was more severe at HT. Nest survival at LSWA (S = 0.495, SE = 0.103) was nearly twice that on HT (S = 0.277, SE = 0.072). We found no evidence that habitat composition or spatial attributes within 210 m of a nest site significantly influenced nest success. Forb canopy at the nest site had a positive influence on nest success at HT but not at LSWA. We suggest nesting habitat with greater forb canopy cover will increase the opportunity for nesting success in landscapes with limited nesting habitat. © 2010 The Wildlife Society.
Estimating abundance of Sitka black‐tailed deer using DNA from fecal pellets
Authors: Brinkman Todd J. , Person David K. , Chapin F. Stuart , Smith Winston , Hundertmark Kris J. 
Published: March 2011

AbstractDensely vegetated environments have hindered collection of basic population parameters on forest‐dwelling ungulates. Our objective was to develop a mark–recapture technique that used DNA from fecal pellets to overcome constraints associated with estimating abundance of ungulates in landscapes where direct observation is difficult. We tested our technique on Sitka black‐tailed deer (Odocoileus hemionus sitkensis) in the temperate coastal rainforest of Southeast Alaska. During 2006–2008, we sampled fecal pellets of deer along trail transects in 3 intensively logged watersheds on Prince of Wales Island, Alaska. We extracted DNA from the surface of fecal pellets and used microsatellite markers to identify individual deer. With genotypes of individual deer, we estimated abundance of deer with moderate precision (±20%) using mark–recapture models. Combining all study sites, we identified a 30% (SE = 5.1%) decline in abundance during our 3‐year study, which we attributed to 3 consecutive severe winters. We determined that deer densities in managed land logged >30 years ago (7 deer/km2, SE = 1.3) supported fewer deer compared to both managed land logged <30 years ago (10 deer/km2, SE = 1.5) and unmanaged land (12 deer/km2, SE = 1.4). Our study provides the first estimates of abundance (based on individually identified deer) for Sitka black‐tailed deer and the first estimates of abundance of an unenclosed ungulate population using DNA from fecal pellets. Our tool enables managers to accurately and precisely estimate the abundance of deer in densely vegetated habitats using a non‐invasive approach. © 2011 The Wildlife Society.
Comparison of techniques for sex determination of American martens
Authors: Belant Jerrold L. , Etter Dwayne R. , Friedrich Paul D. , Cosgrove Melinda K. , Williams Bronwyn W. , Scribner Kim T. 
Published: March 2011

AbstractAccurate determination of sex in harvested species is critical for understanding demography and developing population models for management. We used genetic‐based sex identification to assess accuracy of external carcass and pelt examination at registration and maximum canine root area (MRA) to determine sex of American martens (Martes americana) trapped in the Upper Peninsula of Michigan, 2000–2004. Overall percent similarity between MRA and genetic‐based sex determination was 98.4% (n = 188). In contrast, only 84.6% (n = 421) of martens were similarly classified using external examination. For external examination, percent similarity to genetic‐based sex determination for juveniles (<1‐yr old) and adults (≥1‐yr old; Wald χ21 = 2.168, P = 0.141), as well as for males and females (Wald χ21 = 0.005, P = 0.946), was similar. We recommend MRA as a suitable technique for sex determination of martens; thus, marten sex and age (using cementum annuli counts) can be obtained from one lower canine tooth. We do not recommend use of external examination at registration to identify sex of martens without implementing additional quality assurance measures. © 2010 The Wildlife Society.
Modifications of traps to reduce bycatch of freshwater turtles
Authors: Bruce Bury R. 
Published: March 2011

AbstractMortality of freshwater turtles varies among types and deployments of traps. There are few or no losses in hoop or fyke traps set where turtles may reach air, including placement in shallows, addition of floats on traps, and tying traps securely to a stake or to shore. Turtle mortality occurs when traps are set deep, traps are checked at intervals >1 day, and when turtles are captured as bycatch. Devices are available that exclude turtles from traps set for crab or game fish harvest. Slotted gates in front of the trap mouth reduce turtle entry, but small individuals still may be trapped. Incidental take of turtles is preventable by integrating several designs into aquatic traps, such as adding floats to the top of traps so turtles may reach air or an extension tube (chimney, ramp) that creates an escape route. © 2010 The Wildlife Society.
Nest return times in response to static versus mobile human disturbance
Authors: Weston Michael A. , Ehmke Glenn C. , Maguire Grainne S. 
Published: March 2011

AbstractWe delivered standardized stimuli to incubating hooded plovers (Thinornis rubricollis) to examine the influence of human movement on disruption of incubation. The probability of plovers returning to nests within 60 min was higher in our treatment that mimicked mobile (e.g., walking) humans (85.7%) than in our treatment that mimicked static (e.g., sunbathing) humans (9.5%; n = 20 pairs). Thus, temporary beach closures that reduce or eliminate static but not mobile disturbances are likely to be effective at reducing disruption to incubation caused by human disturbance. © 2011 The Wildlife Society
Detection distance and environmental factors in conservation detection dog surveys
Authors: Reed Sarah E. , Bidlack Allison L. , Hurt Aimee , Getz Wayne M. 
Published: March 2011

AbstractSurveys using conservation detection dogs have grown increasingly popular as an efficient means to gather monitoring data, particularly for elusive and low‐density species such as carnivores. Working with dogs can greatly increase the area surveyed for wildlife and the detection rate of survey targets. Due to the confounding effects of scent dispersion and dog movement, however, it can be difficult to estimate the area searched in a survey. Additionally, although detection dogs have been used in studies under a wide range of air temperature, humidity, and wind conditions, little research has examined how environmental factors affect detection dogs' effectiveness for wildlife surveys. Between 2003 and 2005, we trained 2 dogs to assist us with surveys for mammalian carnivore scats in northern California. We conducted controlled search trials to assess how the dogs' scat detection rates were affected by the distance of scats from the transect search line, as well as variation in six environmental factors. Both dogs detected >75% of scats located within 10 m, and the dogs' detection rates decreased with increasing distance of scats from the transect line. Among environmental factors, precipitation was the most important variable explaining variation in scat detection rates for both dogs. Precipitation likely degrades or removes scats from the landscape over time, and detection rates increase as scat begins to accumulate following the last substantial (>5 mm) rain event of the year. If scat accumulation is not controlled for in ecosystems with a strong seasonal pattern of rainfall, it could lead to considerable bias in study results. We recommend that researchers report the conditions under which conservation detection dog surveys took place and analyze how detection rates vary as a function of distance, temperature, precipitation, humidity, wind, and other locally important environmental factors. © 2010 The Wildlife Society.
Volume‐based trends in surgical care of patients with oropharyngeal cancer
Authors: Gourin Christine G. , Forastiere Arlene A. , Sanguineti Giuseppe , Marur Shanthi , Koch Wayne M. , Bristow Robert E. 
Published: March 2011

AbstractObjective:Positive volume–outcome relationships exist for diseases treated with technically complex surgery. Contemporary patterns of oropharyngeal cancer surgery by hospital and surgeon volume are poorly defined.Methods:The Maryland Health Service Cost Review Commission database was queried for hospital and surgeon oropharyngeal cancer surgical case volumes from 1990 to 2009.Results:Overall, 1,534 oropharyngeal cancer surgeries were performed by 238 surgeons at 41 hospitals. Cases performed by high‐volume surgeons increased from 18.9% in 1990 to 1999 to 24.8% in 2000 to 2009 (odds ratio [OR] = 1.5, P = .002), whereas cases performed at high‐volume hospitals increased from 35.0% to 41.8% (OR = 1.7, P <.001). High‐volume surgeons were significantly associated with university hospitals (OR = 25.9, P < .001) and were more likely to perform partial glossectomy (OR = 1.8, P = .002), total glossectomy (OR = 3.8, P < .001), and neck dissection (OR = 2.3, P < .001). High‐volume hospitals were significantly associated with tonsillectomy (OR = 3.0, P < .001), partial glossectomy (OR = 1.4, P = .044), total glossectomy (OR = 4.3, P < .001), neck dissection (OR = 3.1, P < .001), flap reconstruction (OR = 1.9, P = .028), and prior radiation (OR = 5.0, P < .001). After controlling for other variables, oropharyngeal cancer surgery in 2000 to 2009 was associated with increased utilization of university hospitals (OR = 1.7, P < .001), increased mortality risk scores (OR = 3.1, P = .022), prior radiation (OR = 4.9, P = .011), and a decrease in partial glossectomy (OR = 0.5, P < .001), total glossectomy (OR = 0.4, P = .004), pharyngectomy (OR = 0.6, P = .007), and mandibulectomy (OR = 0.6, P = .022) procedures.Conclusions:The proportion of oropharyngeal cancer surgery patients treated by high‐volume surgeons and hospitals increased significantly from 1990 to 1999 to 2000 to 2009, with a decrease in partial glossectomy, total glossectomy, pharyngectomy, and mandibulectomy procedures. These findings may be due to changing trends in the primary management of oropharyngeal cancer. Laryngoscope, 2011
Laser‐MSG‐Hybridschweißen von Schwarz‐Weiß‐Verbindungen
Authors: Jasnau Ulf , Sumpf André , Brandt René 
Published: March 2011

AbstractObwohl viele Industriezweige Schwarz‐Weiß‐Verbindungen einsetzen, liegen bislang nur wenige Erkenntnisse zum Schweißen solcher Materialkombinationen mit Hochleistungs‐Festkörperlasern vor. Das Projekt „Laserbasiertes Fügen von so genannten ‚SchwarzWeiß‐Verbindungen’︁ größerer Blechdicken mit dem Hochleistungsfaserlaser”︁ ermittelte Parameter, um das Metallschutz(MSG)‐Hybridschweißen mit Lasern auch für das Verbinden von Materialkombinationen aus unlegierten und hochlegierten Stählen größerer Blechdicken nutzbar zu machen. Dabei galt das besondere Interesse den geeigneten Nahtvorbereitungen und den Schweißparametern für das Schweißen von Stumpfnähten an Blechen und Rohren und Stumpfnähten am T‐Stoß.
Aus Tradition auf eigenen Wegen
Authors: Autz Irina , Friedrich Florian 
Published: March 2011

AbstractWie allgemein üblich, ändern sich beim Generationswechsel auch in einem Unternehmen der Blechbearbeitung neben den „Köpfen”︁ meist noch Strategien und Ziele. Dass dabei Lasermaschinen als Konstante bleiben, hat einen guten Grund: Sie erweisen sich gerade beim Bearbeiten von Blechen als Schlüssel für Neues.
Leadership begins with an inner journey
Authors: Kouzes James M. , Posner Barry Z. 
Published: March 2011

AbstractDrawing on the stories of exemplary leaders, the authors argue that all effective leaders must make an inner journey “to discover who you are and what you care about.” Developing your ability to lead, they show, “is not about stuffing in a whole bunch of new information or trying out the latest technique. It's about leading out of what is already in your soul. It's about liberating the leader within you.”
Free‐radical polymerization: An international study
Authors: Eastmond G. C. 
Published: March 2011

AbstractThe International Union of Pure and Applied Chemistry established a Working Party to investigate selected aspects of the kinetics of free‐radical polymerization. This paper, which precedes formal reports of the Working Party's activities and experimental results, describes the experimental programme established. It highlights some aspects of the study and draws attention to lessons learned during the course of the programme.
Initiation of polymerization: Azo compounds and peroxides
Authors: Bevington John C. 
Published: March 2011

AbstractAzobis(isobutyronitrile) and benzoyl peroxide are considered in detail as initiators of radical polymerization; the discussion is extended to other azo compounds and organic peroxides which can be used for the same purpose. Emphasis is placed on the value of isotopic labelling methods for study of the initiators and of the end–groups formed from them.
A review of the kinetics of the low conversion, free‐radical termination process
Authors: Mahabadi Hadi K. 
Published: March 2011

AbstractA review of recent experimental and theoretical results exploring the free‐radical termination process in low conversion polymerization systems is presented. This very interesting and very specific, bimolecular termination step is vital in the development of free‐radical polymerization kinetics and is frequently assumed to operate independent of the reaction system. It is the authors' belief that a good deal of the scatter in low conversion kinetic parameter estimates prevalent in the current literature is due to the effect of nonideal free‐radical termination. While most current work is done in derivation of semi‐empirical correlations describing the magnitude of this effect, such methods lack generality since they, by design, ignore effects which are significant in describing the phenomena. Thus, the predictive ability of such models is compromised from the outset.A general discussion of accepted low conversion kinetic modelling structures and applicable theoretical development of the process by which free‐radical termination occurs at low polymer concentrations is included. A review of current activities in this field is then presented, with a description of experimental techniques, pertinent results, a list of dominant effects and conclusions. Finally, a simple and comprehensive model structure is introduced which will be useful in analyzing low conversion kinetics and predicting rates and molecular weights from a variety of effects.The intentions of this work are to order some of the more important results in the literature in the study of this particular reaction step and thus, provide some clarity and to demonstrate the sensitivity of this reaction step and its potential effect on kinetic predictions for free‐radical polymerizations.
Diffusion in dense polymer fluids
Authors: Lodge Timothy P. , Wheeler Louise , Hartley Brian , Huang W. James , Landry Michael R. , Frick Theodore S. , Lee Jeffrey A. , Tirrell Matthew 
Published: March 2011

AbstractMost reactions involving a polymeric reactant are, or can easily become, diffusion‐controlled. While phenomenological models have been developed, direct fundamental knowledge of the diffusion, and data on the diffusion coefficients are lacking. Data on small molecule and polymer self‐diffusion coefficients are being obtained by two optical techniques over wide ranges of polymer concentration (0–100%) and diffusivity (10−14 to 10−5 cm2/sec). We present here a summary of our work of the last year in diffusion measurement by two different techniques. Forced Rayleigh Scattering (FRS) is being used to study small molecule diffusion in polymer fluids. Dynamic light scattering is being used to study polymer molecule diffusion over same range of variables. We hope through this work to be able to provide a complete picture of molecular mobility under polymerization conditions.
Non‐classical radical propagation
Authors: Kabanov Victor A. 
Published: March 2011

AbstractComplexing of acrylic and methacrylic monomers with Lewis acids results both in their resonance stabilization and polarization of C=C bonds which cause a change of their reactivity in a classical sense. However, non‐classical reaction paths including growing radical‐monomer coordination in the transition state apparently play an important role in homo‐ and copolymerization of such monomers. An alternating copolymerization of acrylic and methacrylic monomers with olefines and dienes in the presence of Lewis acids in some cases proceeds due to a “classical” cross propagation rate constant increase. In the other cases alternation is caused by non‐classical mechanisms such as addition of comonomer complexes as the whole and (or) growing radical–monomer precomplexing. An alternating copolymerization of conventional donor‐acceptor monomer pairs also can proceed via classical and non‐classical reaction paths. ESR method combined with using of spin trap and corresponding kinetic measurements can be successfully applied for clarification of a propagation mechanism in each case.
Molecular weight distributions in free radical polymerizations
Authors: Rudin Alfred 
Published: March 2011

AbstractIn practical polymerization processes the goal is to control reaction conditions so as to produce polymers with optimum balances of properties for different applications. A key to success in this task is an understanding of the effects of the polymerization process on the molecular weight distribution (mwd) of the product as well as the response of polymer properties to changes in mwd. The effects of molecular weight and mwd on properties of commercial polymers made by free radical processes is dimly understood. Mechanical properties of polymer solids are theoretically related to mwd whereas the weight of the scanty evidence that is available suggests correlations with single average values, such as M̄n̄. By contrast, melt rheological properties are often referred to M̄w̄, while the evidence points to overriding effects of mwd.Analyses of mwd's by gel permeation chromatography have made great advances recently, but the value of the results is limited by the relative insensitivity of the technique in the high and low molecular weight regions of the distribution. The differences between various grades of the same commodity polymer are apparently due to nuances in mwd in these regions.Practical free radical polymerizations are very complex reactions. The reaction models must be correspondingly complex. Some illustrations of the value of experimental mwd data to guide predictions of kinetic schemes are given.