bluuebunny/crossref_metadata_2025 huggingface dataset:
Amount of Bone Lengthening Affects Blood Flow Recovery and Bone Mineralization after Distraction Osteogenesis in a Canine Cleft Palate Model
Authors: Aoki Asato , Kawamoto Tatsuo , Aoki Kazuhiro , Inokuchi Takato , Kudoh Atsuo , Nagahama Kouhei , Baba Yoshiyuki , Suzuki Syouichi , Ohya Keiichi , Moriyama Keiji
Published: April 2010

Objectives

Distraction osteogenesis has been applied to the craniofacial region. To reduce the cleft width of patients with cleft lip and palate, alveolar bones are distracted toward the cleft. However, no reports have described limitations to the amount of lengthening that can be achieved by distraction osteogenesis in this area. Therefore, we investigated the healing process following different extents of distraction osteogenesis using a canine cleft palate model.

Methods

A 10-mm bone defect was made in the palates. A bony segment including the canine was prepared and translocated into the defect area at a rate of 1 mm/d for 6 or 10 days, resulting in two groups (6- and 10-mm groups). Canine pulpal blood flow was monitored for 100 days with Doppler flowmetry. Then, the animals were sacrificed and the regenerated bone area was evaluated radiologically and histologically. Statistical significance was confirmed with the Mann-Whitney rank test.

Results

Pulpal blood flow in the 6-mm group recovered to original levels earlier than in the 10-mm group. Cortical bone density in the regenerated bone, measured by peripheral quantitative computed tomography, was significantly greater in the 6-mm group than in the 10-mm group. The amount of regenerated bone in histologic sections was also significantly greater in the 6-mm group.

Conclusion

We clearly showed that healing progress depends on the extent of distraction osteogenesis, highlighting the importance of limited distraction osteogenesis in the alveolar area.
Craniofacial Morphology in Children of Mothers with the m.3243A>G Mutation in Mitochondrial DNA
Authors: Pihlajaniemi Taija L. , Pirttiniemi Pertti , Uusimaa Johanna , Majamaa Kari
Published: April 2010

Objective

To describe craniofacial morphology in children from families with the mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes (MELAS) syndrome.

Design

Transversal prospective case-control study from a tertiary center.

Subjects

Nine children (five girls, four boys; aged 7.5 to 15.3 years) of mothers with m.3243A>G mutation in mitochondrial DNA and 36 age- and sex-matched healthy children as controls.

Methods

Seventy-three cephalometric variables representing craniofacial and dental features were analyzed in lateral radiographs. The statistical dependence caused by intrafamilial correlation was taken into account by using a two-level analysis of variance model that was fitted to the data using SAS procedure MIXED.

Results

The frontal bone was thicker and the frontal sinus, mandibular symphysis width, and lower posterior face height were larger in the subjects than in the controls. Upper incisors were more labially inclined, and the interincisal angle was smaller in subjects than in the control children.

Conclusions

Differences were found in craniofacial structures between the children of mothers with m.3243A>G and unaffected children. Differences in the upper incisor inclination, mandibular symphysis width, and lower posterior face height suggest an altered mandibular growth pattern in the subjects. In addition, the children had cranial aberrations such as larger frontal sinuses and the thicker frontal bone.
Tooth Abnormalities of Number and Position in the Permanent Dentition of Patients with Complete Bilateral Cleft Lip and Palate
Authors: Tereza Guida Paola Genovez , Carrara Cleide Fehcio De Carvalho , Costa Beatriz
Published: April 2010

Objective

To radiographically evaluate the prevalence of tooth abnormalities of number and position in the permanent dentition of individuals with complete bilateral cleft lip and palate.

Design

Cross-sectional retrospective.

Setting

Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo, Bauru, Brazil.

Patients

Two hundred five individuals with complete bilateral cleft lip and palate.

Interventions

Analysis of patient records and panoramic radiographs.

Main outcome measures

Evaluation of hypodontia and supernumerary teeth and analysis of the position of the permanent maxillary lateral incisor in relation to the alveolar cleft.

Results

Hypodontia was observed in 144 patients (70.2%), and the highest prevalence was observed for the maxillary lateral incisor. When both lateral incisors were present (43%), they were primarily located on the distal side of the cleft (25%). Supernumerary teeth were observed in 11.7% of individuals.

Conclusion

Patients with cleft lip and palate presented high prevalence of hypodontia and supernumerary teeth. The prevailing characteristics of their location may suggest the presence of a similar genetic component for the occurrence of hypodontia and cleft.
Clinical Features of the Microform Cleft Lip and the Ultrastructural Characteristics of the Orbicularis Oris Muscle
Authors: Kim Eun Key , Khang Shin Kwang , Lee Taik Jong , Kim Tae Gon
Published: April 2010

Objective

To clarify the clinical features of the microform cleft lip and to establish the ultrastructural characteristics of the orbicularis muscle.

Design

Clinical observations of the characteristic deformities and associated anomalies were made. Muscle biopsies were harvested for histologic and ultrastructural analyses.

Patients

Seventy-one consecutive patients with microform cleft lip were included in the study. Muscle biopsies were investigated in 11 patients among them.

Results

Nasal deformity, a ridge or a groove from the vermilion to the nostril sill, and interruption of the “white roll” were present in all patients. Lack of a philtral column and a free border notch was observed in over 97% of patients. The orbicularis muscle demonstrated hypoplastic myofibers with nonneurogenic atrophy and focal accumulation of subsarcolemmal mitochondria.

Conclusion

The typical gross morphology of the microform cleft lip is a surface manifestation of muscular defect, and the disruption of the muscle further extends down to the ultrastructural level. The clinical features, taken together with the ultrastructural defects of the musculature, might help with a more precise delineation of the microform cleft lip, and provide better understanding of cleft lip in general.
Craniofacial Morphology in Patients with Velocardiofacial Syndrome
Authors: Dalben Gisele Da Silva , Richieri-Costa Antonio , Taveira Luís Antônio De Assis
Published: April 2010

Objective

To compare cephalometric measurements of patients with and without velocardiofacial syndrome.

Design

Cross-sectional.

Setting

Public tertiary craniofacial center.

Subjects

Lateral cephalograms of 18 patients with velocardiofacial syndrome and 18 controls without morphofunctional alterations, matched for gender and age; all cephalograms were obtained before orthodontic intervention.

Main Outcome Measures

The cephalograms were manually traced and digitized for the achievement of linear and angular measurements.

Results

Individuals with velocardiofacial syndrome presented a reduced length of the skull base, retrusion of nasal bones, reduced posterior height of the maxilla, increased gonial angle, increased interincisal angle, greater lingual inclination of the mandibular incisors, reduced nasolabial angle, and reduced nasal depth compared with the control group.

Conclusions

Patients with velocardiofacial syndrome presented morphological differences compared with individuals without morphofunctional alterations, which might be considered in the evaluation of patients with suspected diagnosis of the syndrome, as well as for the establishment of treatment protocols adequate to their needs. The present findings did not support the hypothesis of differences in pharyngeal dimensions mentioned by other authors, suggesting that the velopharyngeal insufficiency in these patients may be caused by functional alterations rather than by anatomical differences.
Quality of Life among Children with Velocardiofacial Syndrome
Authors: Looman Wendy S. , Thurmes Anna K. , O'conner-Von Susan K.
Published: April 2010

Objective

To explore the health-related quality of life (QoL) among children with velocardiofacial syndrome (VCFS) and to compare QoL by gender and with samples of chronically ill and healthy children.

Design and Setting

Cross-sectional design, comparing data obtained from a survey of parents of children with VCFS to previously published data from comparison groups of children who are healthy or who have other chronic conditions.

Participants

Parents of 45 children aged 2 to 18 years with VCFS participated in this study. Results were compared with published data on the same measures from samples of parents of healthy children (n = 10,343) and children with a variety of chronic conditions (n = 683).

Main Outcome Measures

Quality of life, including fatigue, was measured using the PedsQL™ Measurement Model. Strengths were assessed by parent report from a list of character traits developed from the Values in Action Classification System.

Results

Quality of life was lower across all domains compared with healthy children. Boys with VCFS scored significantly lower than girls on school functioning ( p < .05) and cognitive fatigue ( p < .01). Compared with children with chronic conditions, children with VCFS scored lower on emotional ( p < .01), social ( p < .01), and school functioning ( p < .001) but not on physical health. Parents described their children's strengths as humor, caring, kindness, persistence, and enthusiasm.

Conclusions

Quality of life among children with VCFS is characterized by significant challenges in the cognitive, social, and emotional domains. These children have strengths that may be useful in coping with the daily challenges of this condition.
Duplication of the Mandibular Primary Dentition in Orofacial-Digital Syndrome Type IV
Authors: Soneji Bhavin
Published: April 2010

Supernumerary teeth are commonly reported in patients with cleft lip and palate. The presence of a complete duplicate quadrant of teeth, however, is very rare. A patient with orofacial-digital syndrome type IV (Mohr-Majewski) presented with a duplication of the mandibular primary dentition in the right quadrant. Presence of decay and poor oral hygiene dictated intervention and removal of the supernumery teeth. A case report is presented.
Objective Assessment of the Nasal Airway in Unilateral Cleft Lip and Palate—A Long-Term Study
Authors: Mani Maria , Morén Staffan , Thorvardsson Ornolfur , Jakobsson Olafur , Skoog Valdemar , Holmström Mats
Published: April 2010

Objective

To objectively evaluate the nasal function in adults operated on for unilateral cleft lip and palate with one-stage or two-stage palate closure.

Design

The population consists of all unilateral cleft lip and palate patients born from 1960 to 1987 and treated at the Cleft Lip and Palate Center, Uppsala University Hospital, Sweden. The patients were treated according to the same protocol except for palate closure, which was performed in one stage until 1977 and in two stages thereafter. Eighty-three patients participated. Mean follow-up time after primary surgery was 32 years. An age-matched control group underwent the same examinations.

Main Outcome Measures

Nasal minimum cross-sectional area (cm2) and volume (cm3) were assessed (acoustic rhinometry). Airflow resistance (Pa s/cm3) (rhinomanometry), peak inspiratory flow (L/min) (peak nasal inspiratory flow), and number of identified odors (Scandinavian Odor Identification Test) were determined.

Results

The cleft side of unilateral cleft lip and palate patients had significantly lower values for all parameters compared with controls (p < .001). No difference was found between one-stage and two-stage procedures in values for the cleft side. However, the nasal area and volume of the noncleft side were significantly larger in patients who underwent one-stage as compared with two-stage procedures (p < .05).

Conclusion

The nasal airway of unilateral cleft lip and palate patients demonstrates a wide range of impairments that can be quantified by objective measurements. However, the measurements used did not differentiate between patients operated on with the one-stage and two-stage procedures except for values of the noncleft side.
Recycled aggregate concrete (RAC) – comparative analysis of existing specifications
Authors: Gonçalves P. , Brito J.de
Published: April 2010

This paper presents an overall review on how the production of concrete with recycled aggregates is treated in normative standards of different countries, as well as its response to the need for a sustainable development. Based on existing norms and specifications that allow the use of recycled aggregates in the production of concrete, a comparison is made of the parameters involved, such as density, water absorption and contaminants ratio within the recycled aggregates and maximum strength allowed for the recycled aggregate concrete, among others.
Behaviour and analysis of beam–column joint strengthened by cast-in-situ expansion
Authors: Chaimahawan P. , Pimanmas A.
Published: April 2010

This paper presents a joint strengthening method using cast-in-situ expansion. The objective of cast-in-situ expansion is to make a joint stronger than adjoining beams and change failure from brittle joint shear to ductile beam flexure. In this method, cast-in-situ expansions are fabricated around corners of the joint. The cast-in-situ expansion increases joint shear capacity through increased effective joint area and increases anchorage bond capacity of beam bars passing through the joint through increased apparent column depth. An experimental programme is conducted. Four half-scale beam–column specimens were tested under quasi-static cyclic load. The specimens were strengthened with triangular and square expansions. Test results indicated brittle joint shear failure in the control specimen and beam flexural failure in the strengthened specimens. The strength, stiffness and energy dissipation of strengthened specimens were increased. The experiment is supplemented by non-linear finite-element analysis to investigate the flow of stresses in the joint panel and the expansion. The non-linear finite-element analysis applies the fixed smeared crack concept to simulate distributed cracks in the beam, column and joint panel. A one-dimensional discrete joint element is applied to represent the interfacial contact between beam and column and between expansions and members where local non-linearity such as bar pull-out and interface shear may occur. Both experiment and finite-element analyses demonstrate parallel cracks along the edge of expansion, indicating a diagonal compressive strut. Based on the principal stress plot, the finite-element method reveals two load-bearing mechanisms. In addition to the primary diagonal compressive strut in the joint panel, the expansion provides the secondary strut mechanism along the edge of the opposite expansions. The size of expansion has a direct influence on the capacity of the secondary strut. The failure of the strengthened specimens depends on the relative bending capacity of beam sections and the combined capacity of the primary and secondary joint strut mechanism.
Novel direct‐view LED backlight unit with an aspheric microlens array and a rough‐texture sheet
Authors: Tsou Chingfu , Chang Chunming , Lai Tenghsien , Huang Chenghan
Published: April 2010

Abstract— This study proposes a novel direct‐view light‐emitting‐diode (LED) backlight unit with a high‐fill‐factor aspheric microlens array and a rough‐texture sheet. An aspheric microlens array and a rough‐texture sheet made from polysiloxine were used as the grating element and optical diffuser, respectively, which increases light‐extraction efficiency and improves luminance uniformity. The specific aspheric microlens‐array mold was fabricated by using a heating encapsulated air process based on a glass wafer. This microlens array has the features of high fill factor and square‐foot boundary with a continuous surface‐relief profile. This unique out‐of‐plane surface profile creates a square light pattern with uniform luminance, and thus composes a uniform large‐sized light pattern exactly in accordance with the layout of the LED array. The rough‐texture sheet, which can scatter light uniformly, was formed by fine‐grit‐sandpaper molding. Experimental results show that by using an aspheric microlens array and rough‐texture sheet reported here as the backlight diffusing components is highly effective in improving light uniformity at a wide viewing angle. An increase in illuminance by more than 10% was achieved in comparison with commercial backlight modules. Low cost in fabricating the aspheric microlens array and rough‐texture sheet is anticipated due to the simplicity of the process.
A new low‐power driving method for high‐resolution mobile IPS LCDs
Authors: Takada Naoki , Mamba Norio , Eriguchi Takuya , Kudo Yasuyuki , Kotani Yoshihiro , Maki Masahiro , Satou Hideo , Nagao Shouji , Iwasaki Shinichi , Hashimoto Shinya , Akiyama Kenichi , Furuhashi Tsutomu
Published: April 2010

Abstract— High‐resolution displays are now needed for mobile equipment, not only for cell phones but for other devices such as ultra‐mobile PCs (UMPCs) and mobile Internet protocol televisions (IPTVs). A new low‐cost and low‐power driving method for high‐resolution in‐plane‐switching (IPS) liquid‐crystal displays (LCDs) on a low‐temperature polycrystalline‐silicon (LTPS) thin‐film‐transistor (TFT) platform has been developed. Because this method drives common electrodes separated by each line, it can reduce inversion frequency, unlike “dot‐inversion” or “column‐inversion” methods. On the other hand, it was found that horizontal smear is an obstacle to achieve this method. To solve this problem, techniques to optimize the timing of RGB time‐sharing are proposed. A 5‐in. WXGA (1366 × 768) prototype using the new driving method was fabricated, and it was found that the horizontal smear is less than ±1% of the luminance and that the power consumption of the display discharge and charge is 0.245 W.
Nitrogen dynamics in a small arctic watershed: retention and downhill movement of15N
Authors: Yano Yuriko , Shaver Gaius R. , Giblin Anne E. , Rastetter Edward B. , Nadelhoffer Knute J.
Published: April 2010

We examined short‐ and long‐term nitrogen (N) dynamics and availability along an arctic hillslope in Alaska, USA, using a stable isotope of nitrogen (15N), as a tracer. Tracer levels of15NH4+were sprayed once onto the tundra at six sites in four tundra types: heath (crest), tussock with high and low water flux (mid‐ and footslope), and wet sedge (riparian).15N in vegetation and soil was monitored to estimate retention and loss over a 3‐year period.

Nearly all15NH4+was immediately retained in the surface moss–detritus–plant layer, and >57% of the15N added remained in this layer at the end of the second year. Organic soil was the second largest15N sink. By the end of the third growing season, the moss–detritus–plant layer and organic soil combined retained ≥87% of the15N added except at the Midslope site with high water flux, where recovery declined to 68%. At all sites, non‐extractable and non‐labile‐N pools were the principal sinks for added15N in the organic soil.

Hydrology played an important role in downslope movement of dissolved15N. Crest and Midslope with high‐water‐flux sites were most susceptible to15N losses via leaching, perhaps because of deep permeable mineral soil (crest) and high water flow (Midslope with high water flux). Late spring melt season also resulted in downslope dissolved‐15N losses, perhaps because of an asynchrony between N release into melt water and soil immobilization capacity. We conclude that separation of the rooting zone from the strong sink for incoming N in the moss–detritus–plant layer, rapid incorporation of new N into relatively recalcitrant‐soil‐N pools within the rooting zone, and leaching loss from the upper hillslope would all contribute to the strong N‐limitation of this ecosystem. An extended snow‐free season and deeper depth of thaw under warmer climate may significantly alter current N dynamics in this arctic ecosystem.
Stochasticity as an alternative to deterministic explanations for patterns of habitat use by birds
Authors: Campbell Steven P. , Witham Jack W. , Hunter Malcolm L.
Published: April 2010

Stochasticity is rarely explicitly investigated as a determinant of patterns of habitat use, even though evidence of its influence would undermine support for deterministic models of habitat selection. To assess the role of stochasticity in generating patterns in habitat use, we compared observed patterns of year‐to‐year variation in habitat use of 20 bird species over five years with patterns randomly generated from null models with different biological constraints (i.e., abundance, territoriality, exclusion of unused habitat, site fidelity, and habitat preference). We were able to recreate patterns of variability in spatial distributions with one or more null models for 18 species, suggesting an important role of stochasticity. Although year‐to‐year variability could be modeled as a purely stochastic process for only four species, null models in which random variability was constrained by the influences of vegetation or site fidelity collectively matched the observed patterns of variability of all 18 species. Support for these two models suggested that factors that increase the likelihood of returning to a previously used area and thus limit the spatial extent of random territory placement can generate patterns similar to those we observed. Greater support for models with preference constraints (i.e., models that included bird–vegetation associations) over models with avoidance constraints (i.e., models that excluded areas that were never occupied) indicated that preference was the primary mode of habitat selection. Stochastic patterns in habitat use may have resulted from a weak relationship between habitat selection and habitat quality, influence of non‐vegetation habitat features (e.g., climatic fluctuations), nonequilibrium conditions, and a greater influence of stochastic variation at small spatial and temporal scales. Alternatively, responses to environmental cues may have been deterministic, but in summation, these responses may have created variability in spatial distribution patterns that was indistinguishable from random variation. In such cases, we suggest that it may be easier to model variation in habitat use as a random process rather than using deterministic models that account for a multitude of environmental factors influencing habitat selection of birds. Regardless, stochasticity may play a larger role in generating patterns of habitat use than is often considered, and it deserves wider attention.
Using DNA to assess errors in tropical tree identifications: How often are ecologists wrong and when does it matter?
Authors: Dexter Kyle G. , Pennington Terence D. , Cunningham Clifford W.
Published: April 2010

Ecological surveys of tropical tree communities have provided an important source of data to study the forces that generate and maintain tropical diversity. Accurate species identification is central to these studies. Incorrect lumping or splitting of species will distort results, which may in turn affect conclusions. Although ecologists often work with taxonomists, they likely make some identification errors. This is because most trees encountered in the field are not reproductive and must be identified using vegetative characters, while most species descriptions rely on fruit and flower characters. Because every tree has DNA, ecological surveys can incorporate molecular approaches to enhance accuracy. This study reports an extensive ecological and molecular survey of nearly 4000 trees belonging to 55 species in the tree genus Inga (Fabaceae). These trees were sampled in 25 community surveys in the southwestern Amazon. In a process of reciprocal illumination, trees were first identified to species using vegetative characters, and these identifications were revised using phylogenies derived from nuclear and chloroplast DNA sequences.

We next evaluated the effects of these revised species counts upon analyses often used to assess ecological neutral theory. The most common morphological identification errors involved incorrectly splitting rare morphological variants of common species and incorrectly lumping geographically segregated, morphologically similar species. Total error rates were significant (6.8–7.6% of all individuals) and had a measurable impact on ecological analyses. The revised identifications increased support for spatially autocorrelated, potentially neutral factors in determining community composition. Nevertheless, the general conclusions of community‐level ecological analyses were robust to misidentifications. Ecological factors, such as soil composition, and potentially neutral factors, such as dispersal limitation, both play important roles in the assembly of Inga communities. In contrast, species‐level analyses of neutrality with respect to habitat were strongly impacted by identification errors. Although this study found errors in morphological identifications, there was also strong evidence that a purely molecular approach to species identification, such as DNA barcoding, would be prone to substantial errors. The greatest accuracy in ecological surveys will be obtained through a synthesis of traditional, morphological and modern, molecular approaches.
Large herbivore responses to water and settlements in savannas
Authors: Ogutu Joseph O. , Piepho Hans-Peter , Reid Robin S. , Rainy Michael E. , Kruska Russell L. , Worden Jeffrey S. , Nyabenge Meshack , Hobbs N. Thompson
Published: April 2010

Sustaining wildlife and pastoral communities in savannas worldwide depends on understanding how landscapes provide for their needs. The composite effects of multiple forces shape herbivore distribution in savannas. We propose a model describing the distribution of animal density along two resource utilization gradients. The model estimates where animals are most abundant in relation to water and pastoral settlements and how strongly they respond to these gradients, as indicated by the location of peak densities in landscape space and degree of attraction of animals to these locations. We use the model to show that distances to water and settlements interactively influence the distribution of wild herbivore and livestock densities in a semiarid protected and pastoral African savanna. The herbivores were distributed along distance from water and settlement gradients according to four distinct patterns, suggesting the preponderance of constrained foraging. The impact of distance to water and settlement on herbivore distribution was modified by land use type and temporal variation in rainfall, and also varied among different species of wildlife and between wildlife and livestock. Wild herbivores peaked in density farther from settlements than from water and were much more strongly attracted to their points of maximum density in the pastoral than in the protected land. The point of maximum density was farther removed from settlements in the protected than in the pastoral landscape where the wild herbivores were compressed into smaller suitable habitats. The interaction between distances from settlement and water produced discernible spatial segregation among species in terms of the locations of their points of maximum density, presumably to minimize interspecific competition for forage and water. Settlements exerted relatively stronger influence on livestock distribution than water, resulting in densities that declined exponentially away from settlements at all distances from water.
Hydrological change in lakes inferred from midge assemblages through use of an intralake calibration set
Authors: Luoto Tomi P.
Published: April 2010

Midge (Insecta: Diptera: Nematocera) assemblages were examined in surface sediment samples from Lake Pieni‐Kauro and the Saavanjoki River, eastern Finland, using their sedimentary remains. The aim was first to identify the forcing factors behind midge distribution within an aquatic ecosystem and second to develop new midge‐based calibration models for the reconstruction of past environmental conditions, with a special focus on paleohydrology. The third objective was to apply the models to a midge stratigraphy. The effect of sampling‐point selection in paleolimnological studies and its possible influence on chironomid‐inferred temperature reconstructions was also assessed. The species assemblages in Lake Pieni‐Kauro showed high levels of heterogeneity within the surface sediment samples, signifying that the assemblages predominantly incorporate locally dwelling fauna, instead of integrating remains from a larger area. Stream flow and water depth were the most important factors explaining the midge distributions in the lake. In addition, sampling distance from littoral vegetation (DLV), proximity of wetland, distance from shore, and organic content of the sediment were significantly correlated statistically with the midge assemblages. In the lacustrine samples, absolute midge abundance and taxon richness were highest at intermediate water depths. Because hydrological variables were the most important factors controlling the species' distributions, paleohydrological calibration models for water depth and stream flow were developed. Additionally, a transfer function for the sampling DLV was developed that can be used to track changes in the past location of littoral vegetation stands, which is often closely related to hydrological factors. The models' test use on the subfossil midge assemblages of the previously available downcore sediment sequence showed coherent and expected results, compared with previous studies and the modern observed environmental conditions of the lake. Based on the results of this study, these models can provide reliable estimates of past hydrological variability that is closely related to climatic changes and thus may provide a valuable tool for environmental management and global change assessments. This study also indicates that care should be taken in choosing the sampling point in chironomid‐based calibration studies because the influence of depth may distort the temperature estimations.
Climate, snow, ice, crashes, and declines in populations of reindeer and caribou (Rangifer tarandus L.)
Authors: Tyler N. J. C.
Published: April 2010

Snow is a major determinant of forage availability for reindeer and caribou (Rangifer tarandus; hereafterRangifer) in winter and is, consequently, a medium through which climate variation may influence population dynamics in this species. Periodic “icing” of winter ranges, where interludes of mild weather result in formation of crusted snow and basal ice that restrict access to forage, is held to be a cause of mass starvation, catastrophic declines in numbers, and even extirpation of local populations. It has been suggested that warming of the Arctic may result in increased frequency of winters with unfavorable snow and ice conditions, with serious consequences forRangifer. This paper examines data on major declines in populations ofRangiferto determine the mechanism(s) of these events and the role of snow and ice conditions in them. Thirty‐one declines, involving numerical decreases between 25% and 99%, were identified in 12 populations.Declines were of two types: the negative phase of irruptive oscillations, mainly associated with populations introduced into new habitat, and numerical fluctuation in persistently unstable established populations. The mechanisms of decline differed widely in both categories, ranging from wholly mortality to almost wholly emigration. In all cases, the observed dynamics are best interpreted as a product of interaction between internal processes (density dependence) and the external abiotic conditions (density independence). The strength and the form of density independence, parameterized in terms of local weather or large‐scale climate, varies widely between populations, reflecting the enormous range of climate conditions across the circumpolar distribution ofRangifer. This complicates the search for abiotic components likely to be consistently important determinants of population growth in the species. There are few data demonstrating the presence of extensive hard snow or basal ice on ranges during winter(s) in which populations declined, and none confirming ice as a ubiquitous and potent agent in the dynamics ofRangifer. Instead, where the simultaneous effects of density‐dependent and density‐independent factors are examined across the full temporal record of dynamics, climatic conditions associated with increased amounts of snow or winter warming are generally found to enhance the abundance of animals, at least in established populations.
Affective-Cognitive Behavioral Therapy for Somatization Disorder
Authors: Woolfolk Robert L. , Allen Lesley A.
Published: April 2010

Somatization disorder is the most severe and refractory of the somatoform disorders. In this article, we provide an overview of somatization disorder, reviewing both the experimental psychopathology and treatment outcome literatures. We also describe a new psychosocial intervention that we developed to treat somatization disorder, affective-cognitive behavioral therapy. We attempt to place the treatment within the context of contemporary cognitive behavioral therapy.
Avian Density and Nest Survival on the San Pedro River: Importance of Vegetation Type and Hydrologic Regime
Authors: BRAND L. ARRIANA , STROMBERG JULIET C. , NOON BARRY R.
Published: April 2010

Abstract:Lowland riparian vegetation in the southwestern United States is critically important for maintaining a high richness and density of breeding birds. Further investigation is needed within riparian corridors, however, to evaluate the relative importance of vegetation type and hydrologic regime for avian density and nest survival as targets for regional conservation or restoration efforts. We estimated the densities of 40 bird species and for species grouped on the basis of nest height and dependence on surface water in gallery cottonwood–willow (Populusspp.–Salixspp.) forests, saltcedar (Tamarixspp.) shrub lands, and terrace vegetation types along a gradient in the hydrologic regime of the San Pedro River, Arizona, USA. We also assessed nest survival for shrub‐nesting insectivores and herbivores. Canopy‐nesting birds as a group and 14 individual bird species reached their greatest densities in cottonwood forests regardless of the hydrologic regime. Water‐dependent birds as a group reached their highest density in both intermittent‐ and perennial‐flow cottonwood stands, but certain species occurred almost exclusively in perennial‐flow sites. Two shrub‐nesting species and the brown‐headed cowbird (Molothrus ater) were most abundant in saltcedar shrub lands, and the brown‐headed cowbird was most abundant in saltcedar stands with intermittent flows. Mesquite (Prosopisspp.) and big sacaton (Sporobolus wrightii) grassland each maintained the highest densities of certain species within ≥1 hydrologic regime. Shrub‐nesting insectivores had the greatest nest survival in cottonwood, including Arizona Bell's vireo (Vireo bellii arizonae), and also had lower proportions of nests parasitized and preyed upon, although 95% confidence intervals among vegetation types overlapped. Nest survival for both shrub‐nesting insectivores and herbivores was lowest in intermittent‐flow saltcedar, although, again, confidence intervals overlapped. Nest survival was lower in parasitized than nonparasitized nests in mesquite and across vegetation types for Arizona Bell's vireo and in cottonwood for Abert's towhee (Pipilo aberti). Riparian management that maintains heterogeneous riparian vegetation types, including floodplain vegetation comprising cottonwood–willow gallery riparian forests with some stretches of perennial flow, are important for maintaining the high diversity and abundance of breeding birds on the San Pedro River and probably across the region. Cottonwood stands also appear to maintain highest nest survival for some shrub‐nesting birds.
Evaluation of Bear Rub Surveys to Monitor Grizzly Bear Population Trends
Authors: STETZ JEFFREY B. , KENDALL KATHERINE C. , SERVHEEN CHIRSTOPHER
Published: April 2010

Abstract: Wildlife managers need reliable estimates of population size, trend, and distribution to make informed decisions about how to recover at‐risk populations, yet obtaining these estimates is costly and often imprecise. The grizzly bear (Ursus arctos) population in northwestern Montana, USA, has been managed for recovery since being listed under the United States Endangered Species Act in 1975, yet no rigorous data were available to evaluate the program's success. We used encounter data from 379 grizzly bears identified through bear rub surveys to parameterize a series of Pradel model simulations in Program MARK to assess the ability of noninvasive genetic sampling to estimate population growth rates. We evaluated model performance in terms of 1) power to detect gender‐specific and population‐wide declines in population abundance, 2) precision and relative bias of growth rate estimates, and 3) sampling effort required to achieve 80% power to detect a decline within 10 years. Simulations indicated that ecosystem‐wide, annual bear rub surveys would exceed 80% power to detect a 3% annual decline within 6 years. Robust‐design models with 2 simulated surveys per year provided precise and unbiased annual estimates of trend, abundance, and apparent survival. Designs incorporating one survey per year require less sampling effort but only yield trend and apparent survival estimates. Our results suggest that systematic, annual bear rub surveys may provide a viable complement or alternative to telemetry‐based methods for monitoring trends in grizzly bear populations.
Importance of Montane Riparian Forest and Influence of Wildfire on Nest‐Site Selection of Ground‐Nesting Birds
Authors: KIRKPATRICK CHRIS , CONWAY COURTNEY J.
Published: April 2010

Abstract:We studied breeding populations of 2 coexisting ground‐nesting birds, the red‐faced warbler (Cardellina rubrifrons) and yellow‐eyed junco (Junco phaeonotus), in high‐elevation (>2,000 m) forested drainages of the Santa Catalina Mountains, Arizona, USA. From 2004 to 2005, we 1) estimated density and nesting success of breeding populations of red‐faced warblers and yellow‐eyed juncos, 2) identified nest‐site characteristics for each species (i.e., used sites vs. random plots), 3) compared nest‐site characteristics between the 2 species, and 4) examined effects of a recent (2003) wildfire on distribution of nests of both species. In addition, we estimated the areal extent of montane riparian forest (the preferred breeding habitat of both species) within high‐elevation forests of the Santa Catalina Mountains. We found that red‐faced warblers and yellow‐eyed juncos were the 2 most common ground‐nesting birds within our study area with an average density of 2.4 and 1.4 singing males/ha, respectively, along drainage bottoms. Compared to random plots, most red‐faced warbler and yellow‐eyed junco nests were located close (≤30 m) to drainage bottoms within a strip of montane riparian forest characterized by abundant brush, small woody debris, ferns, and forbs (both species), high number and diversity of saplings and small trees (red‐faced warblers), and abundant shrubs and downed logs and less canopy cover (yellow‐eyed juncos). Although both species nested in close proximity within montane riparian forest, nest‐site characteristics differed between the 2 species, especially at finer spatial scales. For example, most yellow‐eyed juncos nested adjacent to grass (principallyMuhlenbergiaspp.), whereas red‐faced warblers nested adjacent to a variety of plant species, including grass, bigtooth maple (Acer grandidentatum), white fir (Abies concolor), and Douglas‐fir (Pseudotsuga menziesii). Both red‐faced warblers and yellow‐eyed juncos avoided nesting in areas burned during a recent wildfire. In addition, nesting success was low for red‐faced warblers (13%) and yellow‐eyed juncos (19%) following the wildfire, suggesting an indirect negative effect of fire on breeding populations in the short‐term. Montane riparian forest appears to provide important breeding habitat for red‐faced warblers and yellow‐eyed juncos. However, little research or conservation planning has been directed toward montane riparian forest in the region, even though this forest type is limited in its areal extent (<11% of high‐elevation forest in the Santa Catalina Mountains) and increasingly threatened by disturbance. Results from our study can be used to facilitate the management and conservation of breeding populations of red‐faced warblers and yellow‐eyed juncos in high‐elevation forests of the southwestern United States.
Paradigm Shifts in Habitat Ecology of Threatened Newfoundland Martens
Authors: HEARN BRIAN J. , HARRISON DANIEL J. , FULLER ANGELA K. , LUNDRIGAN CYRIL G. , CURRAN WILLIAM J.
Published: April 2010

Abstract:We evaluated multiscale habitat selection by threatened Newfoundland (Canada) martens (Martes americana atrata) across landscapes composed of a range of habitat types to test the hypothesis that martens preferred mature (61–80‐yr‐old) and overmature (>80 yr) conifer stands. At both the landscape and stand scales, adult (≥1 yr) resident martens (n= 58, 92 yr‐specific home ranges) selected for, or used in proportion to availability, a broad range of habitat types, including recent cuts ≤ 5 yr old, regenerating forest <6.5 m, precommercially thinned stands, and mature and overmature forest. Marten home ranges were not dominated by mature and overmature forest; median availability of mature and overmature forest within individual home ranges was only 30% (range = 11–76%). Age distributions were not different among martens with high, intermediate, and low quantity of mature and overmature forest in their home range; our data do not indicate that martens inhabiting ranges with little mature and overmature forest were compromising fitness. Habitat selection by martens in Newfoundland was more generalized than has traditionally been inferred, and we suggest that inherent landscape fragmentation, in combination with absence of many predators and competitors (i.e., ecological release), caused the Newfoundland marten to evolve to use a more generalized habitat niche than many mainland populations of American martens. We recommend that landscapes suitable for marten not exceed >29% younger aged forest. Maintaining resident martens in landscapes where forest harvesting is occurring requires prescriptions that recognize the highly fragmented nature of the natural landscape, the prevalence of mature and overmature forest, younger forests, avoided landcover types, and human access.
Fire Effects on Cover and Dietary Resources of Sage‐Grouse Habitat
Authors: RHODES EDWARD C. , BATES JONATHAN D. , SHARP ROBERT N. , DAVIES KIRK W.
Published: April 2010

Abstract: We evaluated 6 years of vegetation response following prescribed fire in Wyoming big sagebrush (Artemisia tridentata spp. wyomingensis) steppe on vegetation cover, productivity, and nutritional quality of forbs preferred by greater sage‐grouse (Centrocercus urophasianus), and abundance of common arthropod orders. Habitat cover (shrubs and tall herbaceous cover [>18 cm ht]) was about 50% lower after burning compared to unburned controls because of the loss of sagebrush. Perennial grasses and an invasive annual forb, pale alyssum (Alyssum alyssoides), increased in cover or yield after fire. There were no increases in yield or nutritional quality of forb species important in diets of sage‐grouse. Abundance of ants (Hymenoptera), a significant component in the diet of young sage‐grouse, decreased after fire. These results suggest that prescribed fire will not improve habitat characteristics for sage‐grouse in Wyoming big sagebrush steppe where the community consists of shrubs, native grasses, and native forbs.
Tracing Genetic Lineages of Captive Desert Tortoises in Arizona
Authors: EDWARDS TAYLOR , JARCHOW CHRISTOPHER J. , JONES CRISTINA A. , BONINE KEVIN E.
Published: April 2010

Abstract: We genotyped 180 captive desert tortoises (Gopherus agassizii) from Kingman (n = 45), Phoenix (n = 113), and Tucson (n = 22), Arizona, USA, to determine if the genetic lineage of captives is associated with that of wild tortoises in the local area (Sonoran Desert). We tested all samples for 16 short tandem repeats and sequenced 1,109 base pairs of mitochondrial DNA (mtDNA). To determine genetic origin, we performed assignment tests against a reference database of 997 desert tortoise samples collected throughout the Mojave and Sonoran Deserts. We found that >40% of our Arizona captive samples were genetically of Mojave Desert or hybrid origin, with the percentage of individuals exhibiting the Mojave genotype increasing as the sample locations approached the California, USA, border. In Phoenix, 11.5% were Sonoran–Mojave crosses, and 8.8% were hybrids between desert tortoise and Texas tortoise (G. berlandieri). Our findings present many potential implications for wild tortoises in the Sonoran Desert of Arizona. Escaped or released captive tortoises with Mojave or hybrid genotypes have the potential to affect the genetic composition of Sonoran wild populations. Genotyping captive desert tortoises could be used to inform the adoption process, and thereby provide additional protection to native desert‐tortoise populations in Arizona.
Scavenging Makes Cougars Susceptible to Snaring at Wolf Bait Stations
Authors: KNOPFF KYLE H. , KNOPFF ALIAH ADAMS , BOYCE MARK S.
Published: April 2010

Abstract:In western Canada it is illegal to trap or snare cougars (Puma concolor), but cougars are sometimes caught accidentally in snares placed near carrion baits, a technique commonly used by trappers to harvest wolves (Canis lupus). We studied cougar foraging ecology and survival in west‐central Alberta to estimate the propensity for cougars to scavenge, their susceptibility to snaring at trapper bait stations, and the implications these have for managing cougar populations. During 2005–2008, we used data from visits to 3,407 Global Positioning System (GPS) location clusters and >400 km of snow tracking of 44 cougars to locate foraging events and calculate scavenging rates. We identified 83 instances of scavenging, and 64% of monitored cougars scavenged at least once. Scavenging rates were higher in winter (0.12 events/week) than in summer (0.04 events/week), reflecting seasonal variation in carrion availability. Individual cougars scavenged at different rates, and winter feeding on carrion occupied up to 50% of total carcass handling time for some cougars. Based on these results we conclude that cougars are facultative scavengers. A propensity to scavenge made cougars susceptible to snaring causing high annual mortality in radiocollared cougars (0.11, 95% CI = 0.03–0.21). Provincial cougar mortality data demonstrate that snaring has increased dramatically as a mortality source in Alberta over the last 2 decades. Mortalities of radiocollared cougars during our study were 100% human caused and the addition of snaring mortality to already high hunting mortality resulted in low annual survival (0.67, 95% CI = 0.53–0.81). Our study is one of the first to identify population‐level consequences for nontarget animals killed unintentionally by indiscriminate harvest techniques in a terrestrial ecosystem. Maintaining sustainable cougar harvest where snaring at carrion baits is permitted may require flexible hunting quotas capable of accommodating high cougar snaring mortalities in some years.