bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil ecosystem functioning under climate change: plant species and community effects
Authors: Kardol Paul , Cregger Melissa A. , Campany Courtney E. , Classen Aimee T.
Published: April 2010

Feedbacks of terrestrial ecosystems to atmospheric and climate change depend on soil ecosystem dynamics. Soil ecosystems can directly and indirectly respond to climate change. For example, warming directly alters microbial communities by increasing their activity. Climate change may also alter plant community composition, thus indirectly altering the soil communities that depend on their inputs. To better understand how climate change may directly and indirectly alter soil ecosystem functioning, we investigated old‐field plant community and soil ecosystem responses to single and combined effects of elevated [CO2], warming, and precipitation in Tennessee (USA). Specifically, we collected soils at the plot level (plant community soils) and beneath dominant plant species (plant‐specific soils). We used microbial enzyme activities and soil nematodes as indicators for soil ecosystem functioning.

Our study resulted in two main findings: (1) Overall, while there were some interactions, water, relative to increases in [CO2] and warming, had the largest impact on plant community composition, soil enzyme activity, and soil nematodes. Multiple climate‐change factors can interact to shape ecosystems, but in our study, those interactions were largely driven by changes in water. (2) Indirect effects of climate change, via changes in plant communities, had a significant impact on soil ecosystem functioning, and this impact was not obvious when looking at plant community soils. Climate‐change effects on enzyme activities and soil nematode abundance and community structure strongly differed between plant community soils and plant‐specific soils, but also within plant‐specific soils.

These results indicate that accurate assessments of climate‐change impacts on soil ecosystem functioning require incorporating the concurrent changes in plant function and plant community composition. Climate‐change‐induced shifts in plant community composition will likely modify or counteract the direct impact of atmospheric and climate change on soil ecosystem functioning, and hence, these indirect effects should be taken into account when predicting the manner in which global change will alter ecosystem functioning.
Ungulate and topographic control of arbuscular mycorrhizal fungal spore community composition in a temperate grassland
Authors: Murray Tanya R. , Frank Douglas A. , Gehring Catherine A.
Published: April 2010

Large herbivores and topo‐edaphic gradients are well‐documented, major determinants of grassland plant production and species composition. In contrast, there is limited information about how these factors together may influence the composition of the arbuscular mycorrhizal fungus (AMF) communities associated with plants. AMF are a common component of grassland ecosystems where they can influence plant productivity, diversity, and soil stability. In this study, AMF community composition was analyzed in paired plots located inside and outside 40–44‐year‐old ungulate exclosures at six grassland sites in Yellowstone National Park (YNP), USA, that varied in soil moisture and the availability of soil nitrogen (N) and phosphorus (P). AMF spore abundance, species richness, and the relative abundance of AMF species were determined from soil samples collected (1) randomly (n= 5 samples) within each of the 12 plots and (2) from beneath the dominant grass (n= 5 samples per plot) at each site. Randomly collected soil samples explored the effects of ungulates and topographic position on AMF composition at the plant community level, subsuming potential effects of ungulates on plant species composition. Dominant plant samples examined how grazers, in particular, influenced AMF communities, while controlling for host‐plant identity. Grazing decreased AMF spore abundance across the landscape (examined by random sampling) but increased the AMF species richness associated with dominant plants. Grazing influenced the AMF species composition at the plant community level and at the host‐plant level by shifting the relative abundances of individual AMF species. Individual AMF species responded differently to grazing and N and P availability. Our results demonstrate how soil moisture and N and P availability across the landscape interact with grazing to influence AMF species composition.
Reconstructing Holocene fire history in a southern Appalachian forest using soil charcoal
Authors: Fesenmyer Kurt A. , Christensen Norman L.
Published: April 2010

Lacking long‐term dendrochronological and lake sediment data, little is known regarding the history of fire in southern Appalachian forests through the Holocene. Here we used 82 radiocarbon ages for soil charcoal collected from local depositional sites along a topographic gradient from mixed hardwood (Liriodendron tulipiferaandQuercusspp.) to oak–pine (Quercus prinusandPinus rigida) forest to provide a coarse‐grained picture of changes in fire frequency within a 10‐ha area during the Holocene. Charcoal ages ranged from 0 to 10 570 yr BP, with a single date older than 4000 yr BP. The data indicate that fires occurred regularly across the study area over the past 4000 yr. Further, such fires were not confined to dry oak–pine dominated ridges, but extended downslope into areas that are today dominated by mesic hardwood forest. Summed probability analysis taking into account radiometric errors suggests that fires became more frequent ∼1000 yr ago, coinciding with the appearance of Woodland Tradition Native Americans in this region. We provide a direct demonstration of relatively frequent fire at the forest stand scale in Appalachian forests over a significant portion of the Holocene. Our results are consistent with the widely held view that fires have become less frequent in this region over the past 250 years. We discuss the difficulties in calculating the inbuilt error associated with estimating actual fire dates from charcoal fragments. But we conclude that such analysis of soil charcoal is a promising approach for reconstructing general trends in fire behavior within forest stands in this region.
Differences in wetland nitrogen cycling between the invasive grass Microstegium vimineum and a diverse plant community
Authors: DeMeester Julie E. , deB. Richter Daniel
Published: April 2010

Wetlands are valuable for buffering waterways from excess nitrogen, yet these habitats are often dominated by invasive plant species. There is little understanding as to how various invasive species alter ecosystem nitrogen cycling, especially if one invasive overtakes an entire community of plants. Microstegium vimineum is a nonnative annual grass from Asia that is dominating riparian wetlands in the southeastern United States. To evaluate M. vimineum impacts on the N cycle, we used six paired plots, one invaded by M. vimineum and the other carefully weeded of M. vimineum; removal allowed the establishment of a diverse plant community consisting of Polygonum, Juncus, and Carex species. In the paired plots, we estimated (1) N uptake and accumulation in vegetation biomass, (2) rates of decomposition and N release from plant detritus, (3) mineral soil N mineralization and nitrification, (4) root zone redox potential, and (5) soil water concentrations of inorganic N. The M. vimineum community accumulated approximately half the annual N biomass of the diverse community, 5.04 vs. 9.36 g N·m−2·yr−1, respectively (P = 0.05). Decomposition and release of N from M. vimineum detritus was much less than in the diverse community, 1.19 vs. 5.24 g N·m−2·yr−1. Significantly higher inorganic soil N persisted beneath M. vimineum during the dormant season, although rates of soil N mineralization estimated by in situ incubations were relatively similar in all plots. Microstegium vimineum invasion thus appears to greatly diminish within‐ecosystem circulation of N through the understory plants of these wetlands, whereas invasion effects on ecosystem N losses may derive more from enhanced denitrification (due to lower redox potential under M. vimineum plots) than due to leaching. Microstegium vimineum's dominance and yet slower internal cycling of N are counterintuitive to conventional thinking that ecosystems with high N contain vegetation that quickly uptake and release N.
The contribution of brown vegetation to vegetation dynamics
Authors: Okin Gregory S.
Published: April 2010

Indices of vegetation dynamics that include both green vegetation (GV) and non‐photosynthetic vegetation (NPV), that is, brown vegetation, were applied to MODIS surface reflectance data from 2000 to 2006 for the southwestern United States. These indices reveal that the cover of NPV, a measure of vegetation brownness and a component of ecosystems worldwide, is highly variable in both space and time in the study region. In the more mesic regions of the study area, the timing of peaks in NPV appears to result from simple senescence of GV at the end of the growing season. In these regions, the amplitude of GV cyclicity dominates the total vegetation signal. In contrast, in arid and semiarid regions, the amplitude of cyclicity of NPV dominates the total vegetation signal, showing the vegetation of these regions to be unexpectedly dynamic. Shrublands of southwestern United States exhibit temporal behavior in which the annual peak in NPV cover precedes the annual peak in GV cover by a few months. Several explanations for this behavior are offered. This study shows the importance of vegetation indices that include NPV, or vegetation brownness, in understanding terrestrial ecosystem dynamics, as well as the response to change for these ecosystems.
Eco‐evolutionary dynamics: fluctuations in population growth rate reduce effective population size in chinook salmon
Authors: Waples Robin S. , Jensen David W. , McClure Michelle
Published: April 2010

We empirically assess the relationship between population growth rate (λ, a parameter central to ecology) and effective population size (Ne, a key parameter in evolutionary biology). Recent theoretical and numerical studies indicate that in semelparous species with variable age at maturity (such as Pacific salmon, many monocarpic plants, and various other species), differences in mean reproductive success among individuals reproducing in different years leads to variation in λ, and this in turn can reduce Ne. However, this phenomenon has received little empirical evaluation. We examined time series of abundance data for 56 populations of chinook salmon (Onchorhynchus tshawytscha) from the northwestern United States and compared Ne (calculated from demographic data) with the total number of spawners each generation (NT). Important results include: (1) The mean multigenerational ratio xÑe/xÑT was 0.64 (median = 0.67), indicating that annual variation in λ reduces effective population size in chinook salmon by an average of ∼35%. These reductions are independent of, and in addition to, factors that reduce Ne within individual cohorts (uneven sex ratio and greater‐than‐random variance in reproductive success). (2) The coefficient of variation of λ was the most important factor associated with reductions in Ne, explaining up to two‐thirds of the variance in xÑe/xÑT. (3) Within individual generations, Ne was lower when there was a negative correlation between annual Ni and λ, i.e., when relatively few breeders produced relatively high numbers of offspring. Our results thus highlight an important and little‐studied eco‐evolutionary trade‐off: density‐dependent compensation has generally favorable ecological consequences (promoting stability and long‐term viability) but incurs an evolutionary cost (reducing Ne because a few individuals make a disproportionate genetic contribution). (4) For chinook salmon, Nx^eH (an estimator based on the harmonic mean number of breeders per year) is generally a good proxy for true Ne and requires much less data to calculate.
Analysis of ecological time series with ARMA(p,q) models
Authors: Ives Anthony R. , Abbott Karen C. , Ziebarth Nicolas L.
Published: April 2010

Autoregressive moving average (ARMA) models are useful statistical tools to examine the dynamical characteristics of ecological time‐series data. Here, we illustrate the utility and challenges of applying ARMA(p,q) models, wherepis the dimension of the autoregressive component of the model, andqis the dimension of the moving average component. We focus on parameter estimation and model selection, comparing both maximum likelihood (ML) and restricted maximum likelihood (REML) parameter estimation. While REML estimation performs better (has less bias) than ML estimation for ARMA(p,q) models withp= 1 (as has been found previously), for models withp> 1 the performance of the estimators is complicated by multimodal likelihood functions. The resulting difficulties in estimation lead to our recommendation that likelihood functions be routinely investigated when applying ARMA(p,q) models. To aid this investigation, we provide MATLAB and R code for the ML and REML likelihood functions. We further explore the consequences of measurement error, showing how it can be explicitly and implicitly incorporated into estimation. In addition to parameter estimation, we also examine model selection for identifying the correct model dimensions (pandq). Finally, we estimate the characteristic return rate of the stochastic process to its stationary distribution, a quantity that describes a key property of population dynamics, and investigate bias that results from both estimation and model selection. While fitting ARMA models to ecological time series with complex dynamics has challenges, these challenges can be surmounted, making ARMA a useful and broadly applicable approach.
Ultraviolet radiation affects invasibility of lake ecosystems by warm‐water fish
Authors: Tucker Andrew J. , Williamson Craig E. , Rose Kevin C. , Oris James T. , Connelly Sandra J. , Olson Mark H. , Mitchell David L.
Published: April 2010

Predicting where species invasions will occur remains a substantial challenge in ecology, but identifying factors that ultimately constrain the distribution of potential invaders could facilitate successful prediction. Whereas ultraviolet radiation (UVR) is recognized as an important factor controlling species distribution and community composition, the role of UVR in a habitat invasibility context has not been explored. Here we examine how underwater UVR can regulate warm‐water fish invasion. In Lake Tahoe, California and Nevada, USA, established populations of exotic bluegill sunfish (Lepomis macrochirus) are currently limited to turbid, low‐UVR embayments. An in situ incubation experiment that manipulated incident UVR exposure of larval bluegill, combined with an assessment of UVR exposure levels in nearshore habitats around Lake Tahoe, demonstrates that UVR can mediate habitat invasibility. Our findings suggest that the susceptibility to invasion by UVR sensitive species may increase in transparent aquatic systems threatened by declining water quality, and they highlight the importance of abiotic factors as regulators of invasion risk in ecosystems.
Short‐ and long‐term population response to changes in vital rates: implications for population viability analysis
Authors: Chirakkal Haridas , Gerber Leah R.
Published: April 2010

Conservation practitioners use demographic population viability analysis (PVA) to understand long‐term effects of changing demographic rates on population growth rate. Sensitivities and elasticities of stage‐specific survival and fertility rates provide managers with guidelines on the relative contributions of various life‐history stages to long‐term population growth. However, short‐term patterns, especially single‐year effects, of elasticity may be dramatically different from long‐term effects, calling for caution in implementing management policies focusing entirely on only long‐ or short‐term elasticities. Here we illustrate the temporal and spatial variation in elasticity patterns for four populations of California sea lions. Short‐term stochastic elasticities were significantly different from long‐term elasticities, and spatial patterns of short‐ and long‐term elasticities varied across sites. These differences may be explained by transient effects in age structure and deviations from the stable age distribution, as well as environmental variation. Our results suggest that conservation practitioners should consider calculations of both short‐and long‐term elasticity in viability analyses that are used to guide management and should use caution in generalizing elasticity patterns across populations.
The Jena Experiment: six years of data from a grassland biodiversity experiment
Authors: Weigelt Alexandra , Marquard Elisabeth , Temperton Vicky M. , Roscher Christiane , Scherber Christoph , Mwangi Peter N. , Felten Stefanievon , Buchmann Nina , Schmid Bernhard , Schulze Ernst-Detlef , Weisser Wolfgang W.
Published: April 2010

This data set contains species‐specific biomass and cover data as well as community leaf area index (LAI) and height from a large grassland biodiversity experiment (Jena Experiment). In this experiment, 82 grassland plots of 20 × 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, and tall and small herbs). In May 2002, varying numbers of plant species were sown into the plots to create a gradient of plant species richness (1, 2, 4, 8, 16, and 60 species) and functional richness (1, 2, 3, and 4 functional groups). Plots were maintained by biannual weeding and mowing. The data set encompasses the 2002–2008 May and August biomass harvests from 3–4 subplots of 0.2 × 0.5 m per experimental plot sorted to species. Moreover, plant species and community cover estimated in an approximately 9‐m2 subplot per plot are included in the data set. Each biomass harvest was accompanied by measurements of vegetation height and LAI per plot. Analyses of the community biomass data have identified species richness as well as functional group composition as important drivers of a positive biodiversity–productivity relationship.

The data set can be used to study a variety of questions about how plant community composition and structure respond to changes in species richness and functional diversity over time. Sampling is ongoing, and new data will be added.

The complete data sets corresponding to abstracts published in the Data Papers section of the journal are published electronically in Ecological Archives at 〈http://esapubs.org/archive〉. (The accession number for each Data Paper is given directly beneath the title.)
Periodontal Regeneration Using an Anabolic Peptide With Two Carriers in Baboons
Authors: Yamashita Motofumi , Lazarov Mirella , Jones Archie A. , Mealey Brian L. , Mellonig James T. , Cochran David L.
Published: April 2010

Background: Various growth proteins have been used to encourage periodontal tissue regeneration. The purpose of this pilot study is to evaluate the periodontal regeneration achieved with the use of a synthetic anabolic peptide (AP) combined with either beta‐tricalcium phosphate (β‐TCP) or an absorbable collagen sponge (ACS) as the carrier.

Methods: Periodontal defects were created bilaterally adjacent to four mandibular teeth in five baboons. Plaque was allowed to accumulate around wire ligatures placed into the defects. After 2 months, the wire ligatures were removed, and a notch was placed at the base of the defect. The four teeth were randomly treated with one of the following treatments: 1) saline + ACS serving as the control, 2) AP + ACS, 3) saline + β‐TCP serving as another control, or 4) AP + β‐TCP. The baboons were sacrificed 5 months post‐treatment, and histomorphometric analyses were performed under masked conditions.

Results: At 5 months post‐surgery, the mean length of new cementum for sites treated with AP + ACS, AP + β‐TCP, saline + ACS, saline + β‐TCP amounted to 3.32 ± 1.7 mm, 3.86 ± 1.0 mm, 2.87 ± 1.3 mm, and 3.15 ± 1.9 mm, respectively. The mean width of new cementum for the corresponding values was 52.5 ± 14.7 μm, 54.5 ± 24.2 μm, 37.4 ± 12.7 μm, and 48.9 ± 12.4 μm, respectively. The mean width of new periodontal ligament for corresponding values was 246 ± 140 μm, 166 ± 26 μm, 251 ± 92 μm, and 240 ± 91 μm. No statistically significant difference was observed for any of the parameters among groups in this pilot study.

Conclusions: Preclinical studies showed that AP has positive anabolic effects on bone cells. In this study, no adverse tissue reactions were observed in the AP‐treated sites, including root resorption, ankylosis, or a foreign body reaction. The cementum length and width were greater in the sites treated with AP versus sites treated with a control; however, these differences were not significant in the small number of animals used. Further research is needed to define the potential of AP as a periodontal therapeutic agent.
Validation of an Algorithm for Chronic Periodontitis Risk Assessment and Prognostication: Analysis of an Inflammatory Reactivity Test and Selected Risk Predictors
Authors: Lindskog Sven , Blomlöf Johan , Persson Inger , Niklason Anders , Hedin Anders , Ericsson Leif , Ericsson Mats , Järncrantz Bo , Palo Ulf , Tellefsen Georg , Zetterström Olle , Blomlöf Leif
Published: April 2010

Background: Patients with severe forms of chronic periodontitis present with varying degrees of decreased inflammatory reactivity. A previously reported algorithm for chronic periodontitis risk assessment and prognostication is based on the analysis of some 20 risk predictors. One of these predictors is a skin provocation test that assesses the individual patient's reactivity to a lipid A challenge. The aim of this report was to analyze results from validation data for the algorithm with respect to the contribution of results of the skin provocation test as a risk predictor for the progression of chronic periodontitis and to compare these results with the contribution from other predictors, namely smoking, angular bony destruction, furcation involvement, abutment teeth, and endodontic pathology.

Methods: Data from a previously reported clinical validation sample were used for the analysis, including the calculation of quality measures and explanatory values using different types of regression analysis and non‐parametric testing.

Results: Smoking, endodontic pathology, abutment teeth, angular bony destruction, and furcation involvement presented with individual explanatory values for periodontitis progression between 4% and 13% and highly significant parameter estimates. Explanatory values for the results of the skin provocation test ranged between 2.6% and 5.1% depending on the disease severity group, with a positive predictive value of 82% for the identification of high‐risk patients.

Conclusion: The skin provocation test provided a clinically significant contribution to the quality of analysis with the periodontitis risk and prognostication algorithm, in particular in the selection of high‐risk patients for in‐depth individual tooth analysis.
Periodontitis and Inflammatory Markers in Transplant Recipients
Authors: Shaqman Murad , Ioannidou Effie , Burleson Joseph , Hull David , Dongari‐Bagtzoglou Anna
Published: April 2010

Background: Inflammation is associated with the deterioration of solid‐organ transplants. Chronic periodontitis is linked to systemic inflammation, although it is unknown whether it plays a causative or comorbid role. We hypothesized that transplant subjects have a greater prevalence of severe periodontitis, accompanied by higher levels of serum interleukin‐6 (IL‐6) and C‐reactive protein (CRP), compared to systemically healthy subjects.

Methods: We recruited 90 renal and cardiac transplant recipients and 72 age‐matched controls and compared their periodontal and systemic inflammatory status.

Results: The prevalence of severe periodontitis was not statistically significantly different between transplant and control subjects. Serum IL‐6 and CRP were higher in transplant subjects compared to control subjects and in subjects with severe periodontitis compared to subjects without periodontitis, but multivariate analysis showed that severe periodontitis was a significant positive predictor of serum IL‐6 in the control group only. In the test group, significant predictors of systemic inflammation were age, diabetes, higher body mass index, and a cadaveric transplant donor.

Conclusion: Despite the presence of higher levels of systemic markers of inflammation in transplant subjects with severe periodontitis compared to transplant subjects without periodontitis, periodontal parameters were not statistical predictors of systemic inflammation in this population in a multivariate model.
Human Bone Repair After Mandibular Symphysis Block Harvesting: A Clinical and Tomographic Study
Authors: Verdugo Fernando , Simonian Krikor , D'Addona Antonio , Pontón José , Nowzari Hessam
Published: April 2010

Background: There are limited data on the healing potential of osseous defects in the human mandible. Animal model studies have shown that defect fill is size dependent.

Methods: Twenty patients who had autogenous block transplants harvested from the mandibular symphysis were included in the study. Computerized tomography (CT) scans were carried out at an average of 26.7 months after augmentation to assess bone healing. Subgroups were compared on the basis of bone volume harvested, healing time, incision design, symphysis midline preservation, age, and gender. Percentage bone fill was calculated by comparing the preoperative and postoperative CT scans using a computer software program.

Results: CT scan analysis showed a significant percentage (74.5% ± 10.36%) of bone fill at an average of 26.7 ± 22.3 months (range, 4 to 72 months). Healing time and bone volume harvested were significant variables influencing the osteogenic potential of mandibular donor‐site defects. Defects <0.5 cc with a healing period of 34.2 months showed 81% ± 7.4% bone fill, whereas those >0.5 cc and 7.2 months of healing had a repair of 63.8% ± 12.2% (P <0.05; 95% CI, 2.46 to 31.93). A positive trend in bone fill was observed for subgroups receiving sulcular incisions (80%) and midline preservation (77.5%).

Conclusions: The osteogenic potential of human osseous repair in the mandibular symphysis is size and time dependent. The process of osteogenesis of repair in humans seems to be multifactorial. Such factors as preservation of the periosteum and symphysis cortical midline may positively influence defect fill allowing for reharvesting.
Stimulatory Effects of Areca Nut Extracts on Prostaglandin E2 Production by Human Polymorphonuclear Leukocytes
Authors: Lai Yu‐Lin , Wu Ching‐Yi , Lee Ya‐Yun , Chang Hui‐Wen , Liu Tsung‐Yun , Hung Shan‐Ling
Published: April 2010

Background: Areca quid chewing increases the prevalence of periodontal diseases. Areca nut extract (ANE) inhibits the defensive functions of human polymorphonuclear leukocytes (PMNs). This in vitro study investigates the effects of ANE on the production of cyclooxygenase (COX)‐2 and the inflammatory mediator prostaglandin E2 (PGE2) by PMNs.

Methods: The possible effects of ANE on the production of COX‐2 were examined using Western blotting analysis. The viability and production of PGE2 of treated PMNs were determined using the propidium iodide staining method and the competition enzyme assay, respectively. The possible pathways involved were also examined using the COX‐2 inhibitor (NS398), the intracellular calcium chelator 1,2‐bis(2‐aminophenoxy)ethane‐N, N, N′, N′‐tetraacetic acid tetrakis (acetoxymethyl ester) (BAPTA‐AM), the p38 mitogen‐activated protein kinase (MAPK) inhibitor (SB203580), and the extracellular signal‐regulated protein kinase (ERK) inhibitor (U0126). The effects of ANE on the viability or PGE2 production were statistically assessed using a one‐way analysis of variance and Tukey multiple‐comparison intervals with α = 0.05.

Results: ANE significantly induced the production of PGE2 in a time‐ and concentration‐dependent manner. This induction resulted from an increased expression of COX‐2. Moreover, the application of BAPTA‐AM, SB203580, and U0126 statistically significantly suppressed the induction of PGE2.

Conclusions: ANE induced the production of PGE2. The activation of the intracellular calcium concentrations, p38 MAPK, and ERK may be involved in the inducing effects of ANE on PMNs. The findings suggest that areca nut chewing may induce an inflammatory response and affect the periodontal health of consumers.
Double Flap Incision Design for Guided Bone Regeneration: A Novel Technique and Clinical Considerations
Authors: Hur Yong , Tsukiyama Teppei , Yoon Tae‐Ho , Griffin Terrence J.
Published: April 2010

Background: Premature membrane exposure for guided bone regeneration may result in complications, such as inadequate bone regeneration, inflammatory reactions, and wound infection. This paper presents a clinical case of a novel incision‐flap design used to advance the flap to enhance tension‐free primary closure for the vertical ridge augmentation.

Methods: A 61‐year‐old white man presented with the chief complaint of wanting to replace his posterior mandibular teeth. A severe alveolar bone deformity vertically and horizontally (Seibert Class III) was noticed, especially over the mental foramen area. A staged guided bone regeneration procedure prior to the implant installation was chosen as the most optimal treatment. A partial‐thickness flap, separating the mucosal flap from the periosteum overlying the alveolar bone, was used to advance the flap.

Results: During the healing period, neither soft tissue dehiscence nor membrane exposure were noted. Clinical and radiographic evaluation revealed a 4‐ to 5‐mm gain in vertical height and a noticeable increase in horizontal thickness. After the 6 to 8 months of healing for both sites, two implants were placed on each side with good primary stability and without complications.

Conclusions: This technique facilitates flap advancement by the tension‐free nature of the design and enhances soft tissue maintenance during the course of regeneration. This approach, the separation of the periosteal layer and the mucosal layer, can be used as an alternative to overcome some of the limitations with conventional technique.
Early Loading at 21 Days of Non‐Submerged Titanium Implants With a Chemically Modified Sandblasted and Acid‐Etched Surface: 3‐Year Results of a Prospective Study in the Posterior Mandible
Authors: Bornstein Michael M. , Wittneben Julia‐Gabriela , Brägger Urs , Buser Daniel
Published: April 2010

Background:This study evaluates 3‐year success rates of titanium screw‐type implants with a chemically modified sandblasted and acid‐etched surface (mod SLA), which were functionally loaded after 3 weeks of healing.

Methods:A total of 56 implants, inserted in the posterior mandibles of 39 partially edentulous patients, underwent undisturbed healing for 3 weeks. At day 21, the implants were fully loaded with provisional crowns. Definitive metal ceramic restorations were fabricated after 6 months of healing. Clinical measurements regarding soft tissue parameters and radiographs were obtained at different time points up to 36 months after implant placement. The soft tissue and radiographic parameters for the mod SLA implants after 3 years in function were compared to a historic control group of implants with an SLA surface using an early loading protocol after 6 weeks.

Results:None of the implants failed to integrate. However, two implants were considered “spinners” at day 21 and were left unloaded for an extended period. Therefore, 96.4% of the inserted implants were loaded according to the protocol tested. All 56 implants, including the “spinners,” showed favorable clinical and radiographic findings at the 3‐year follow‐up examination. All 56 implants were considered successfully integrated, resulting in a 3‐year survival and success rate of 100%. Dental implants with a mod SLA surface demonstrated statistically significant differences for probing depths and clinical attachment level values compared to the historic control group, with the mod SLA surface implants having overall lower probing depths and clinical attachment level scores.

Conclusion:This prospective study using an early loading protocol demonstrates that titanium implants with the mod SLA surface can achieve and maintain successful tissue integration over a period of 3 years.
Immediate Loading of a Dental Implant Placed in Fresh Socket With Acute Dehiscence‐Type Defect: A Clinical Case Report
Authors: Villa Roberto , Crespi Roberto , Capparè Paolo , Gherlone Enrico
Published: April 2010

Background: The aim of the present clinical case is to show buccal bone repair around a dental implant placed by flapless technique and immediately loaded in fresh socket with acute buccal dehiscence‐type defect.

Methods: A 58‐year‐old female presented with a fistula on the buccal side and a root fracture at the left lateral incisive. The dental extraction was performed without mucogingival flap elevation; the absence of buccal bone plate was recorded. A screw‐shaped implant was placed. Immediately after the surgical procedure, the patient received temporary prosthetic restoration, and 3 months later definitive metal‐ceramic restoration was positioned.

Results: Four years later, a fracture of the crown and gingival inflammatory process were observed. The crown was removed and a fracture of the zirconia abutment was reported. Surgical reentry was performed, gingival flap was raised, and buccal bone repair was observed.

Conclusion: Biologically, it is very difficult to explain the bone repair process around implants in the acute dehiscence‐type defect, and only biologic speculations explain the outcome of this clinical result.
Removal of Hydrogen Sulfide from Gas Stream Using a Novel Metal Membrane Prepared by Wire Arc Spraying
Authors: Madaeni Sayed Siavash , Aalami-Aleagha Mohammad Ebrahim , Taei Babak , Amirinejad Mehdi , Daraei Parisa
Published: April 2010

In this research, we have demonstrated the feasibility of fabrication of a novel metal membrane by wire arc spraying. The feedstock wires were made of carbon steel (1.1% C, 1.9% Mn, and 1.8% Cr). The effects of stand-off distance between the gun and the substrate and the pressure of atomizing gas on the oxides, the porosity and mean pore size of the prepared membranes were studied. The SEM micrograph showed that the prepared membranes are asymmetrically porous. They were not uniform. The performance of prepared membranes was elucidated using gas stream containing hydrogen sulfide. The membranes with higher porosity exhibited gas permeability. Hydrogen sulfide reacts with the available iron in the membrane and produces iron sulfide and hydrogen. Hydrogen sulfide was considerably removed from the gas stream. The EDX test on the reacted membrane indicated that FeS covered the active surface of the metal membrane.
Zombie Politics and other Late Modern Monstrosities in the Age of Disposability
Authors: Giroux Henry A.
Published: April 2010

Monsters of disaster are special kinds of divine warning. They are harbingers of things we do not want to face, of catastrophes, and we fear they will bring such events upon us by coming to us. (Jane Anna Gordon & Lewis R. Gordon)[2]
Managing Reward in Developing Economies: The Challenge for Multinational Corporations
Authors: Opute John
Published: April 2010

Reward has been, and continues to be, subject to significant changes in developing economies; the industrial relations model prevalent being driven by the complex socio-economic and cultural paradigms and the increasing demands of globalisation. The issue of reward in developing economies is therefore central and dependent on numerous contextual factors. The research presented in this article focuses on emerging trends in reward management practices in a developing economy, like Nigeria. Nigeria, with a population of about 140 million people and the economic opportunities derivable from its oil wealth, provides substantial opportunities for industrialisation. Consequently, the country continues to attract investment by multinational corporations. However, because of its evolving industrial relations setting, reward management is complex. This can be seen in the context of the interlocking roles of national institutions, culture, socio-economic factors and employee engagement in developing an appropriate framework. The framework of the research is based on both qualitative and quantitative analysis of data collected from 11 companies, through interviews and questionnaires. The conclusion points at the significant role industrial relations must assume. In particular, it highlights how essential contextual factors and employee engagement are in generating a supportive framework for the challenges facing multinationals in reward management.
Assessing the Debt: George W. Bush's Legacy and the Future of Public Education under Barack Obama
Authors: Means Alex , Taylor Kendall
Published: April 2010

This article utilizes Gloria Ladson-Billings' notion of educational debt in order to explore the historical, economic, and cultural politics of education reform under George W. Bush and Barack Obama. It tracks the No Child Left Behind Act across a number of fields in order to claim that Bush's expansion of the educational debt should be understood as both an exacerbation of systemic inequality as well as the erosion of the democratic purposes of public education. In conclusion, the article forecasts ahead to the future of the educational debt under the Obama administration by looking at the policies implemented in Chicago under former Chicago Public Schools chief executive, and now current secretary of education, Arne Duncan. The authors contend that the sociopolitical infrastructure of Bush's No Child Left Behind presents a fundamental challenge to progressive educational reform under an Obama administration.
After Pell Grants: The Neoliberal Assault on Prisoners
Authors: Yates Mark T. , Lakes Richard D.
Published: April 2010

The number of prisoners in the United States has accelerated over the past thirty years, giving it the highest incarceration rate in the world. The rise in the prison rate has coincided with the ascendancy of neoliberal policies of governance. These include, deregulation of markets, reduction of welfare services, and harsh punitive measures for those who transgress social mores. Contained within neoliberal criminal policy is the proclivity to utilize prisons as a means to maintain societal inequities. This article examines the link between prisoner education policy and wider social and economic policies that disproportionately affect people of color and the poor. Neoliberal prisoner education is predicated, in part, upon the privileging of vocational training over liberal, higher learning. Current policy, typified by the recently passed Second Chance Act, reinforces hierarchies both in education and in the workplace by narrowly defining prisoners as human capital within the market.
Did Educational Expansion Trigger the Development of an Education Society? Chances and Risks of a New Model of Society
Authors: Haunberger Sigrid
Published: April 2010

This article focuses on the question of whether educational expansion leads to a new type of society, the education society. Taking into consideration the combined elements of three models of society (the post-industrial society, the knowledge society and the information society) – the chances and risks of an educational society will be elicited and, subsequently, confronted with an empirical validation. It turned out that modern societies are not education societies. Only a society which reflects upon the difficulty of the unfair distribution of opportunities through the differential access to knowledge and institutional obstacles of the educational system can become an actual education society.
Acoustogyration diffraction of optical waves: case of SiO2 and TeO2 crystals
Authors: Martynyuk-Lototska I. , Mys O. , Akimov S. , Krupych O. , Vlokh R.
Published: April 2010

Interaction of acoustic and light waves with accounting for elastooptic and elastogyration effects is theoretically described. Collinear acoustogyration diffraction in quartz and paratellurite crystals is experimentally investigated and thoroughly analyzed. Piezogyration effect is experimentally studied for TeO2 crystals. The acoustogyration efficiency and the acoustogyration figure of merit calculated for a number of crystals (GaAs, TeO2 and SiO2) are shown to be too small for experimental detection. On the other hand, we demonstrate that the light diffraction at periodical distribution of the imaginary part of dielectric permittivity related to the piezogyration effect should, in principle, be observed for the case of interaction of optical waves with enantiomorphous ferroelastic domain structure and in cholesteric liquid crystals.
Impact of Work-Related Pain on Physical Therapists and Occupational Therapists
Authors: Campo Marc , Darragh Amy R.
Published: April 2010

Background

Physical therapists and occupational therapists experience high rates of work-related pain. Although most therapists continue to work through this pain, it interferes with work and alters therapists’ work habits. However, the effects on productivity, quality of patient care, and therapists’ quality of life and long-term career plans are unknown.

Objectives

The purpose of this study was to determine the impact of working with work-related pain on physical therapists and occupational therapists.

Design

Multiple methods were used in this study. It was primarily a phenomenological study.

Methods

A phenomenological approach was used to explore the meaning of work-related pain in therapists. Focus group interviews were used as the method of data collection. A questionnaire was used to supplement the qualitative analysis.

Results

Nineteen therapists participated in 4 focus groups ranging from 2 to 7 participants each. The participants noted substantial effects of work-related pain at work, at home, and in their career plans. All of the therapists were concerned about their potential clinical longevity. The professional culture complicated these effects by forcing therapists into a professional ideal.

Conclusions

Work-related pain affects therapists in several personal and professional domains. It also may affect career plans. Strategies to reduce the risk of injury and physical loading of jobs are needed.
A Balance Exercise Program Appears to Improve Function for Patients With Total Knee Arthroplasty: A Randomized Clinical Trial
Authors: Piva Sara R. , Gil Alexandra B. , Almeida Gustavo J.M. , DiGioia Anthony M. , Levison Timothy J. , Fitzgerald G. Kelley
Published: April 2010

Background

Patients with total knee arthroplasty (TKA) have impaired balance and movement control. Exercise interventions have not targeted these impairments in this population.

Objectives

The purposes of this study were: (1) to determine the feasibility of applying a balance exercise program in patients with TKA, (2) to investigate whether a functional training (FT) program supplemented with a balance exercise program (FT+B program) could improve physical function compared with an FT program alone in a small group of individuals with TKA, and (3) to test the methods and calculate sample size for a future randomized trial with a larger study sample.

Design

This study was a double-blind, pilot randomized clinical trial.

Setting

The study was conducted in the clinical laboratory of an academic center.

Participants

The participants were 43 individuals (30 female, 13 male; mean age=68 years, SD=8) who underwent TKA 2 to 6 months prior to the study.

Interventions

The interventions were 6 weeks (12 sessions) of a supervised FT or FT+B program, followed by a 4-month home exercise program.

Measurements

Feasibility measures included pain, stiffness, adherence, and attrition. The primary outcome measure was a battery of physical performance tests: self-selected gait speed, chair rise test, and single-leg stance time. Secondary outcome measures were the Western Ontario and McMaster Universities Osteoarthritis Index and the Lower Extremity Functional Scale.

Results

Feasibility of the balance training in people with TKA was supported by high exercise adherence, a relatively low dropout rate, and no adverse events. Both groups demonstrated clinically important improvements in lower-extremity functional status. The degree of improvement seemed higher for gait speed, single-leg stance time, and stiffness in the FT+B group compared with the FT group.

Limitations

Due to the pilot nature of the study, differences between groups did not have adequate power to show statistical significance.

Conclusions

There is a need for conducting a larger randomized controlled trial to test the effectiveness of an FT+B program after TKA.
Effect of a Home Program of Hip Abductor Exercises on Knee Joint Loading, Strength, Function, and Pain in People With Knee Osteoarthritis: A Clinical Trial
Authors: Sled Elizabeth A. , Khoja Latif , Deluzio Kevin J. , Olney Sandra J. , Culham Elsie G.
Published: April 2010

Background

Hip abductor muscle weakness may result in impaired frontal-plane pelvic control during gait, leading to greater medial compartment loading in people with knee osteoarthritis (OA).

Objective

This study investigated the effect of an 8-week home strengthening program for the hip abductor muscles on knee joint loading (measured by the external knee adduction moment during gait), strength (force-generating capacity), and function and pain in individuals with medial knee OA.

Design

The study design was a nonequivalent, pretest-posttest, control group design.

Setting

Testing was conducted in a motor performance laboratory.

Patients

An a priori sample size calculation was performed. Forty participants with knee OA were matched for age and sex with a control group of participants without knee OA.

Intervention

Participants with knee OA completed a home hip abductor strengthening program.

Measurements

Three-dimensional gait analysis was performed to obtain peak knee adduction moments in the first 50% of the stance phase. Isokinetic concentric strength of the hip abductor muscles was measured using an isokinetic dynamometer. The Five-Times-Sit-to-Stand Test was used to evaluate functional performance. Knee pain was assessed with the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire.

Results

Following the intervention, the OA group demonstrated significant improvement in hip abductor strength, but not in the knee adduction moment. Functional performance on the sit-to-stand test improved in the OA group compared with the control group. The OA group reported decreased knee pain after the intervention.

Limitations

Gait strategies that may have affected the knee adduction moment, including lateral trunk lean, were not evaluated in this study.

Conclusions

Hip abductor strengthening did not reduce knee joint loading but did improve function and reduce pain in a group with medial knee OA.