bluuebunny/crossref_metadata_2025 huggingface dataset:
Periodontitis and Rheumatoid Arthritis: A Review
Authors: Bartold P.M. , Marshall R.I. , Haynes D.R.
Published: November 2005

Periodontitis and rheumatoid arthritis (RA) appear to share many pathologic features. In this review, the common pathologic mechanisms of these two common chronic conditions are explored. Emerging evidence now suggests a strong relationship between the extent and severity of periodontal disease and RA. While this relationship is unlikely to be causal, it is clear that individuals with advanced RA are more likely to experience more significant periodontal problems compared to their non‐RA counterparts, and vice versa. A case is made that these two diseases could be very closely related through common underlying dysfunction of fundamental inflammatory mechanisms. The nature of such dysfunction is still unknown. Nonetheless, there is accruing evidence to support the notion that both conditions manifest as a result of an imbalance between proinflammatory and anti‐inflammatory cytokines. As a result, new treatment strategies are expected to emerge for both diseases that may target the inhibition of proinflammatory cytokines and destructive proteases. The clinical implications of the current data dictate that patients with RA should be carefully screened for their periodontal status.
A Proposed Model Linking Inflammation to Obesity, Diabetes, and Periodontal Infections
Authors: Genco Robert J. , Grossi Sara G. , Ho Alex , Nishimura Fusanori , Murayama Yoji
Published: November 2005

Background: Obesity is an important risk factor for diabetes, cardiovascular disease, and periodontal disease. Adipocytes appear to secrete proinflammatory cytokines which may be the molecules linking the pathogenesis of these diseases. We evaluated the relationship between obesity, periodontal disease, and diabetes mellitus insulin resistance as well as the plasma levels of tumor necrosis factor alpha (TNFα) and its soluble receptors (sTNFα) to assess the relationship of inflammation to obesity, diabetes, and periodontal infections.

Methods: The relationship between periodontal disease, obesity, and insulin resistance was examined in the Third National Health and Nutrition Examination Survey (NHANES III). In a population of 12,367 non‐diabetic subjects, the variable body mass index (BMI) was used as an assessment of obesity and periodontal disease was assessed by mean clinical attachment loss. The plasma levels of TNFα and sTNFα were assessed in subsets of 1,221 adults from Erie County, New York, who represented the highest and lowest quartile of BMI. These subjects had extensive periodontal and medical evaluations.

Results: In the NHANES III portion of the study, BMI was positively related to severity of periodontal attachment loss (P <0.001). Weighted multiple logistic regressions showed that this relationship is likely mediated by insulin resistance, since overweight individuals (with BMI ≥27 kg/m2) with high levels of insulin resistance (IR) exhibited an odds ratio of 1.48 (95% confidence interval 1.13 ‐ 1.93) for severe periodontal disease as compared to overweight subjects with low IR. In the Erie County adult population, the highest levels of TNFα and sTNFα receptors were found in those individuals in the highest quartile of BMI. A positive correlation of TNFα levels with periodontal disease was found only in those in the lowest quartile of BMI.

Conclusions: Obesity is a significant predictor of periodontal disease and insulin resistance appears to mediate this relationship. Furthermore, obesity is associated with high plasma levels of TNFα and its soluble receptors, which in turn may lead to a hyperinflammatory state increasing the risk for periodontal disease and also accounting in part for insulin resistance. Further studies of the molecular basis of insulin resistance and its relationship to diabetes, periodontal disease, and obesity are necessary to fully test the hypothesis that adipocyte production of proinflammatory cytokines is a pathogenic factor linking obesity to diabetes and periodontal infections.
Dental Infections and Cardiovascular Diseases: A Review
Authors: Mattila Kimmo J. , Pussinen Pirkko J. , Paju Susanna
Published: November 2005

Accumulating evidence suggests that chronic infections, such as periodontitis, are associated with increased risk for cardiovascular diseases (CVD). The mechanisms behind the association are not known. Like herpes viruses and Chlamydia pneumoniae, periodontal pathogens cause atherosclerosis in experimental animals and have been found in human atherosclerotic lesions. Higher concentrations of total and low density lipoprotein (LDL) cholesterol and triglycerides and lower concentrations of high density lipoprotein (HDL) cholesterol have been observed in individuals with periodontitis before periodontal treatment. Periodontitis also induces a peripheral inflammatory and immune response, reflected in elevated concentrations of C‐reactive protein (CRP) and IgA‐class antibodies to periodontal pathogens. The prevalence of CVD seems to be highest in those individuals in whom periodontitis coexists with elevated CRP levels. This may indicate that periodontitis is a CVD risk factor in individuals who react to the infection with a systemic inflammatory and immune response. This may be due to genetic reasons and may also apply to other chronic low‐grade infections.
Systemic Effects of Periodontitis: Epidemiology of Periodontal Disease and Cardiovascular Disease
Authors: Beck James D. , Offenbacher Steven
Published: November 2005

There have been 42 published studies describing associations between oral conditions and cardiovascular diseases. In the absence of randomized controlled trials, the 16 longitudinal studies represent the highest level of evidence available. However, two databases produced eight of the 16 studies. There also is extensive variability in definitions of the oral exposure that include salivary flow, reported periodontal disease, number of teeth, oral organisms, antibodies to oral organisms, Total Dental Index, Community Periodontal Index of Treatment Needs, plaque scores, probing depth, attachment loss, and bone level. Variability also exists in the cardiovascular outcomes that include atherosclerosis measures and events, such as hospitalization for coronary heart disease (CHD), chronic CHD, fatal CHD, total stroke, ischemic stroke, and revascularization procedures. One of the criticisms of this research is that the exposure has not been represented by measures of infection. To begin to address this concern, we present new data showing that patterns of high and low levels of eight periodontal pathogens and antibody levels against those organisms are related to clinical periodontal disease as well as other characteristics of the individuals, such as age, race, gender, diabetic status, atherosclerosis, and CHD. As others before us, we conclude that the cumulative evidence presented above supports, but does not prove, a causal association between periodontal infection and atherosclerotic cardiovascular disease or its sequelae. A number of legitimate concerns have arisen about the nature of the relationship and, indeed, the appropriate definitions for periodontal disease when it is thought to be an exposure for systemic diseases. There is still much work needed to identify which aspects of the exposure are related to which aspects of the outcome. Principal component analyses illustrate the complexity of the interactions among risk factors, exposures, and outcomes. These analyses provide an initial clustering that describes and suggests the presence of specific syndromes.
Systemic Markers of Inflammation in Periodontitis
Authors: Loos Bruno G.
Published: November 2005

This literature review summarizes current knowledge on the systemic levels of selected markers of inflammation in periodontitis. From samples of peripheral blood the following cellular factors are discussed: total number of white blood cells, red blood cells, and thrombocytes. Further, plasma levels of acute‐phase proteins, cytokines, and coagulation factors are reviewed. From the available literature it appears that the total numbers of leukocytes and plasma levels of C‐reactive protein are consistently higher in periodontitis patients compared to healthy controls. Numbers of red blood cells and levels of hemoglobin are lower in periodontitis and there is a trend towards anemia of chronic disease. Most systemic markers of inflammation discussed in this review are also regarded as predictive markers for cardiovascular diseases. Therefore, changes in these markers in periodontitis may be part of the explanation why periodontitis is associated with cardiovascular diseases and/or cerebrovascular events in epidemiological studies. It is hypothesized that possibly daily episodes of a bacteremia originating from periodontal lesions are the cause for the changes in systemic markers in periodontitis; the cumulative size of all periodontal lesions in the untreated severe patient may amount to 15 to 20 cm2.
The Association Between Osteoporosis and Alveolar Crestal Height in Postmenopausal Women
Authors: Wactawski‐Wende Jean , Hausmann Ernest , Hovey Kathleen , Trevisan Maurizio , Grossi Sara , Genco Robert J.
Published: November 2005

Background: Evidence supporting an association between osteoporosis and loss of alveolar crestal bone is limited. This study investigated that association in a large cohort of postmenopausal women.

Methods: A cohort of 1,341 postmenopausal women aged 53 to 85 were assessed for alveolar crestal height (ACH) and bone density. ACH was determined from oral radiographs with subjects dichotomized by disease severity. Bone density was assessed by dual energy x‐ray absorptiometry, with severity determined by worst T score measured (normal >−1.00; low −1.00 to −2.00; moderate −2.01 to −2.49; osteoporotic <−2.5).

Results: Compared to subjects in the normal T‐score group, the odds of worse ACH increased by 39%, 59%, and 230% for those in the low, moderate, and osteoporotic groups, respectively. Adjustment for weight, education, hormone use, calcium or vitamin D supplementation, and smoking did not appreciably change the findings. Further adjustment for age attenuated the association, with osteoporotic subjects having a 1.9‐fold increase of being in the worst ACH group (95% confidence interval [CI] 1.19 to 3.05). After age stratification, in women younger than 70 there was a significant trend by decreasing T‐score category (P <0.02). Osteoporotic subjects had worse ACH (odds ratio [OR] = 1.95; 95% CI 1.20 to 3.17). In women aged 70 and older, worse ACH was 2.5‐ to 4.6‐fold increased for decreasing T‐score category. After adjustment, the OR (95% CI) for the low, moderate, and osteoporotic groups were 2.66 (1.12 to 6.29), 2.31 (0.89 to 6.01), and 3.57 (1.42 to 8.97), respectively (P trend = 0.026).

Conclusions: This study found a strong and consistent association between T score and ACH in postmenopausal women. Increasing age is an important modifier of that association.
Periodontitis and Airway Obstruction
Authors: Katancik James A. , Kritchevsky Stephen , Weyant Robert J. , Corby Patricia , Bretz Walter , Crapo Robert O. , Jensen Robert , Waterer Grant , Rubin Susan M. , Newman Anne B.
Published: November 2005

Background: The objective of this study was to examine the relationship between airway obstruction and periodontal disease.

Methods: Participants were a subset of 860 community‐ dwelling, well functioning elderly (aged 70 to 79, blacks and whites, males and females) selected from 2,732 participants enrolled in the Health, Aging, and Body Composition Study (Health ABC). The periodontal evaluations occurred over years 2 and 3 of the study and included four indices of periodontal health: plaque index (PI), gingival index (GI), probing depth (PD), and loss of attachment (LOA). The pulmonary evaluation took place in year 1: conducted according to American Thoracic Society criteria, based on the forced expiratory volume/forced vital capacity (FEV1/FVC) ratio and then using the percent of predicted FEV1 to categorize severity.

Results: GI (P = 0.023) and LOA (P = 0.009) were significantly better in participants with normal pulmonary function compared to those with airway obstruction after adjusting for age, race, gender, and field center. When stratified by smoking status and after adjusting for age, race, gender, center, and pack‐years, there was a significant association between periodontal health and airway obstruction in former smokers. Within this group, those with normal pulmonary function had significantly better GI (P = 0.036) and LOA (P = 0.0003) scores than those with airway obstruction. All periodontal indices were elevated in smokers regardless of pulmonary status; however, the current smoker group was too small to detect a periodontitis effect.

Conclusion: While the present cross‐sectional study cannot provide direct inference of cause and effect, it does reveal a significant association between periodontal disease and airway obstruction, particularly in former smokers.
Resolution of Inflammation in Periodontitis
Authors: Kantarci Alpdogan , Van Dyke Thomas E.
Published: November 2005

Chronic inflammatory illnesses such as diabetes, arthritis, and heart disease are now seen as problems that might have impacts on the periodontium, and reciprocal effects of periodontal diseases are being considered as factors potentially affecting the progression of these diseases. Successful management of the inflammatory disorders in the human body depends on the identification of common pathways that would lead to a better understanding of the disease processes and development of novel treatment strategies. In this review, our objective is to identify the inflammatory basis of periodontal disease and common inflammatory mechanisms underlying several disorders elsewhere in the body, with an emphasis on how the potential extrinsic and intrinsic control methods could be used to prevent or treat the harmful effects linked to inflammation.
Cadmium, Copper, Nickel, and Zinc Availability in a Biosolids‐Amended Piedmont Soil Years after Application
Authors: Sukkariyah Beshr F. , Evanylo Gregory , Zelazny Lucian , Chaney Rufus L.
Published: November 2005

Concerns over the possible increase in phytoavailability of biosolids‐applied trace metals to plants have been raised based on the assumption that decomposition of applied organic matter would increase phytoavailability. The objectives of this study were to assess the effect of time on chemical extractability and concentration of Cd, Cu, Ni, and Zn in plants on plots established by a single application of biosolids with high trace metals content in 1984. Biosolids were applied to 1.5 by 2.3 m confined plots of a Davidson clay loam (clayey, kaolinitic, thermic Rhodic Kandiudults) at 0, 42, 84, 126, 168, and 210 Mg ha−1 The highest biosolids application supplied 4.5, 760, 43, and 620 kg ha−1 of Cd, Cu, Ni, and Zn, respectively. Radish (Raphanus sativus L.), romaine lettuce (Lactuca sativa L. varlongifolia), and barley (Hordeum vulgare L.) were planted at the site for 3 consecutive years, 17 to 19 yr after biosolids application. Extractable Cd, Cu, Ni, and Zn (as measured by DTPA, CaCl2, and Mehlich‐1) were determined on 15‐cm depth samples from each plot. The DTPA‐extractable Cu and Zn decreased by 58 and 42%, respectively, 17 yr after application despite a significant reduction in organic matter content. Biosolids treatments had no significant effect on crop yield. Plant tissue metal concentrations increased with biosolids rate but were within the normal range of these crops. Trace metal concentrations in plants generally correlated well with the concentrations extracted from soil with DTPA, CaCl2, and Mehlich‐1. Metal concentrations in plant tissue exhibited a plateau response in most cases. The uptake coefficient values generated for the different crops were in agreement with the values set by the Part 503 Rule.
Mycorrhizae Increase Arsenic Uptake by the Hyperaccumulator Chinese Brake Fern (Pteris vittataL.)
Authors: Al Agely Abid , Sylvia David M. , Ma Lena Q.
Published: November 2005

Chinese brake fern (Pteris vittataL.) is a hyperaccumulator of arsenic (As) that grows naturally on soils in the southern United States. It is reasonable to expect that mycorrhizal symbiosis may be involved in As uptake by this fern. This is because arbuscular mycorrhizal (AM) fungi have a well‐documented role in increasing plant phosphorus (P) uptake, P and As have similar chemical properties, and ferns are known to be colonized by AM fungi. We conducted a factorial greenhouse experiment with three levels of As (0, 50, and 100 mg kg−1) and P (0, 25, and 50 mg kg−1) and with and without Chinese brake fern colonized by a community of AM fungi from an As‐contaminated site. We found that the AM fungi not only tolerated As amendment, but their presence increased frond dry mass at the highest As application rate. Furthermore, the AM fungi increased As uptake across a range of P levels, while P uptake was generally increased only when there was no As amendment. These data indicate that AM fungi have an important role in arsenic accumulation by Chinese brake fern. Therefore, to effectively phytoremediate As‐contaminated soils, the mycorrhizal status of ferns needs to be taken into account.
Freeze–Thaw Effects on Phosphorus Loss in Runoff from Manured and Catch‐Cropped Soils
Authors: Bechmann Marianne E. , Kleinman Peter J. A. , Sharpley Andrew N. , Saporito Lou S.
Published: November 2005

Concern over nonpoint source P losses from agricultural lands to surface waters in frigid climates has focused attention on the role of freezing and thawing on P loss from catch crops (cover crops). This study evaluated the effect of freezing and thawing on the fate of P in bare soils, soils mixed with dairy manure, and soils with an established catch crop of annual ryegrass (Lolium multiflorum L.). Experiments were conducted to evaluate changes in P runoff from packed soil boxes (100 by 20 by 5 cm) and P leaching from intact soil columns (30 cm deep). Before freezing and thawing, total P (TP) in runoff from catch‐cropped soils was lower than from manured and bare soils due to lower erosion. Repeated freezing and thawing significantly increased water‐extractable P (WEP) from catch crop biomass and resulted in significantly elevated concentrations of dissolved P in runoff (9.7 mg L−1) compared with manured (0.18 mg L−1) and bare soils (0.14 mg L−1). Catch crop WEP was strongly correlated with the number of freeze–thaw cycles. Freezing and thawing did not change the WEP of soils mixed with manures, nor were differences observed in subsurface losses of P between catch‐cropped and bare soils before or after manure application. This study illustrates the trade‐offs of establishing catch crops in frigid climates, which can enhance P uptake by biomass and reduce erosion potential but increase dissolved P runoff.
Root Exudation, Phosphorus Acquisition, and Microbial Diversity in the Rhizosphere of White Lupine as Affected by Phosphorus Supply and Atmospheric Carbon Dioxide Concentration
Authors: Wasaki Jun , Rothe Annett , Kania Angelika , Neumann Günter , Römheld Volker , Shinano Takuro , Osaki Mitsuru , Kandeler Ellen
Published: November 2005

White lupine (Lupinus albus L.) was used as a phosphorus (P)‐efficient model plant to study the effects of elevated atmospheric CO2 concentrations on (i) P acquisition, (ii) the related alterations in root development and rhizosphere chemistry, and (iii) the functional and structural diversity of rhizosphere microbial communities, on a P‐deficient calcareous subsoil with and without soluble P fertilization. In both +P (80 mg P kg−1) and −P treatments (no added P), elevated CO2 (800 μmol mol−1) increased shoot biomass production by 20 to 35% and accelerated the development of cluster roots, which exhibit important functions in chemical mobilization of sparingly soluble soil P sources. Accordingly, cluster root formation was stimulated in plants without P application by 140 and 60% for ambient and elevated CO2 treatments, respectively. Intense accumulation of citrate and increased activities of acid and alkaline phosphatases, but also of chitinase, in the rhizosphere were mainly confined to later stages of cluster root development in −P treatments. Regardless of atmospheric CO2 concentrations, there was no significant effect on accumulation of citrate or on selected enzyme activities of C, N, and P cycles in the rhizosphere of individual root clusters. Discriminant analysis of selected enzyme activities revealed that mainly phosphatase and chitinase contributed to the experimental variance (81.3%) of the data. Phosphatase and chitinase activities in the rhizosphere might be dominated by the secretion from cluster roots rather than by microbial activity. Alterations in rhizosphere bacterial communities analyzed by denaturing gradient gel electrophoresis (DGGE) were related with the intense changes in root secretory activity observed during cluster root development but not with elevated CO2 concentrations.
Phosphorus Losses from Agricultural Areas in River Basins
Authors: Kronvang B. , Bechmann M. , Lundekvam H. , Behrendt H. , Rubæk G. H. , Schoumans O. F. , Syversen N. , Andersen H. E. , Hoffmann C. C.
Published: November 2005

In this paper we show the quantitative and relative importance of phosphorus (P) losses from agricultural areas within European river basins and demonstrate the importance of P pathways, linking agricultural source areas to surface water at different scales. Agricultural P losses are increasingly important for the P concentration in most European rivers, lakes, and estuaries, even though the quantity of P lost from agricultural areas in European catchments varies at least one order of magnitude (<0.2 kg P ha−1 to >2.1 kg P ha−1). We focus on the importance of P for the implementation of the EU Water Framework Directive and discuss the benefits, uncertainties, and side effects of the different targeted mitigation measures that can be adopted to combat P losses from agricultural areas in river basins. Experimental evidence of the effects of some of the main targeted mitigation measures hitherto implemented is demonstrated, including: (i) soil tillage changes, (ii) treatment of soils near ditches and streams with iron to reduce P transport from source areas to surface waters, (iii) establishment of buffer zones for retaining P from surface runoff, (iv) restoration of river–floodplain systems to allow natural inundation of riparian areas and deposition of P, and (v) inundation of riparian areas with tile drainage water for P retention. Furthermore, we show how river basin managers can map and analyze the extent and importance of P risk areas, exemplified by four catchments differing in size in Norway, Denmark, and the Netherlands. Finally, we discuss the factors and mechanisms that may delay and/or counteract the responses of mitigation measures for combating P losses from agricultural areas when monitored at the catchment scale.
Long‐Term Effects of Poultry Litter, Alum‐Treated Litter, and Ammonium Nitrate on Aluminum Availability in Soils
Authors: Moore P. A. , Edwards D. R.
Published: November 2005

Research has shown that alum [Al2(SO4)3·14H2O] applications to poultry litter can greatly reduce phosphorus (P) runoff, as well as decrease ammonia (NH3) volatilization. However, the long‐term effects of fertilizing with alum‐treated litter are unknown. The objectives of this study were to evaluate the long‐term effects of normal poultry litter, alum‐treated litter, and ammonium nitrate (NH4NO3) on aluminum (Al) availability in soils, Al uptake by tall fescue (Festuca arundinacea Schreb.), and tall fescue yields. A long‐term study was initiated in April of 1995. There were 13 treatments (unfertilized control, four rates of normal litter, four rates of alum‐treated litter, and four rates of NH4NO3) in a randomized block design. All fertilizers were broadcast applied to 52 small plots (3.05 × 1.52 m) cropped to tall fescue annually in the spring. Litter application rates were 2.24, 4.49, 6.73, and 8.98 Mg ha−1 (1, 2, 3, and 4 tons acre−1); NH4NO3 rates were 65, 130, 195, and 260 kg N ha−1 and were based on the amount of N applied with alum‐treated litter. Soil pH, exchangeable Al (extracted with potassium chloride), Al uptake by fescue, and fescue yields were monitored periodically over time. Ammonium nitrate applications resulted in reductions in soil pH beginning in Year 3, causing exchangeable Al values to increase from less than 1 mg Al kg−1 soil in Year 2 to over 100 mg Al kg−1 soil in Year 7 for many of the NH4NO3 plots. In contrast, normal and alum‐treated litter resulted in an increase in soil pH, which decreased exchangeable Al when compared to unfertilized controls. Severe yield reductions were observed with NH4NO3 beginning in Year 6, which were due to high levels of acidity and exchangeable Al. Aluminum uptake by forage and Al runoff from the plots were not affected by treatment. Fescue yields were highest with alum‐treated litter (annual average = 7.36 Mg ha−1), followed by normal litter (6.93 Mg ha−1), NH4NO3 (6.16 Mg ha−1), and the control (2.89 Mg ha−1). These data indicate that poultry litter, particularly alum‐treated litter, may be a more sustainable fertilizer than NH4NO3
Predicting Soil Fumigant Air Concentrations under Regional and Diverse Agronomic Conditions
Authors: Cryer Steven A.
Published: November 2005

SOFEA (SOil Fumigant Exposure Assessment system; Dow AgroSciences, Indianapolis, IN) is a new stochastic numerical modeling tool for evaluating and managing human inhalation exposure potential associated with the use of soil fumigants. SOFEA calculates fumigant concentrations in air arising from volatility losses from treated fields for large agricultural regions using multiple transient source terms (treated fields), geographical information systems (GIS) information, agronomic specific variables, user‐specified buffer zones, and field reentry intervals. A modified version of the USEPA Industrial Source Complex Short Term model (ISCST3) is used for air dispersion calculations. Weather information, field size, application date, application rate, application type, soil incorporation depth, pesticide degradation rates in air, tarp presence, field retreatment, and other sensitive parameters are varied stochastically using Monte Carlo techniques to mimic region and crop specific agronomic practices. Regional land cover, elevation, and population information can be used to refine source placement (treated fields), dispersion calculations, and risk assessments. This paper describes the technical algorithms of SOFEA and offers comparisons of simulation predictions for the soil fumigant 1,3‐dichloropropene (1,3‐D) to actual regional air monitoring measurements from Kern, California. Comparison of simulation results to daily air monitoring observations is remarkable over the entire concentration distribution (average percent deviation of 44% and model efficiency of 0.98), especially considering numerous inputs such as meteorological conditions for SOFEA were unavailable and approximated by neighboring regions. Both current and anticipated and/or forecasted fumigant scenarios can be simulated using SOFEA to provide risk managers and product stewards the necessary information to make sound regulatory decisions regarding the use of soil fumigants in agriculture.
Volunteer Revegetation of Waste Rock Surfaces at the Bingham Canyon Mine, Utah
Authors: Borden Richard K. , Black Rick
Published: November 2005

Voluntary recolonization of sulfide‐bearing waste rock dumps by native vegetation is inhibited by the harsh chemical and physical conditions. The success of volunteer vegetation on the waste rock surfaces at the Bingham Canyon (Utah) porphyry copper deposit is most strongly dependent on the soil pH and salinity, and to a lesser extent on physical characteristics such as compaction and distance from seed source. Vegetation cover and richness both decline below a paste pH of about 6 and above a paste conductivity of about 0.7 dS/m (for a 1:1 soil to water mixture). No significant vegetation establishment occurs below a soil pH of about 4.5. Young sulfide‐bearing waste rock surfaces at Bingham Canyon have high salinity, but as reactive pyrite is depleted and salts are flushed from the soil, the salinity eventually declines, allowing volunteer native vegetation to become established on surfaces with a circumneutral pH. Under natural conditions, the pH of older acidic weathered surfaces will recover very slowly, but it can be rapidly raised by adding relatively small amounts of limestone because there are few intact reactive sulfides. For uncompacted waste rock surfaces with favorable chemical conditions, less than 90% gravel content, and that are located near a native seed source, the arithmetic mean volunteer vegetation cover was 56 ± 24% and the mean species richness was 17 ± 5. These data indicate that with adequate surface preparation and limestone addition, direct planting of older, acidic, but low salinity waste rock surfaces can greatly accelerate natural revegetation.
Biotic and Abiotic Degradation of CL‐20 and RDX in Soils
Authors: Crocker Fiona H. , Thompson Karen T. , Szecsody James E. , Fredrickson Herbert L.
Published: November 2005

The caged cyclic nitramine 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (CL‐20) is a new explosive that has the potential to replace existing military explosives, but little is known about its environmental toxicity, transport, and fate. We quantified and compared the aerobic environmental fate of CL‐20 to the widely used cyclic nitramine explosive hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX) in surface and subsurface soil microcosms. Soil‐free controls and biologically attenuated soil controls were used to separate abiotic processes from biologically mediated processes. Both abiotic and biological processes significantly degraded CL‐20 in all soils examined. Apparent abiotic, first‐order degradation rates (k) for CL‐20 were not significantly different between soil‐free controls (0.018 < k < 0.030 d−1) and biologically attenuated soil controls (0.003 < k < 0.277 d−1). The addition of glucose to biologically active soil microcosms significantly increased CL‐20 degradation rates (0.068 < k < 1.22 d−1). Extents of mineralization of 14C–CL‐20 to 14CO2 in biologically active soil microcosms were 41.1 to 55.7%, indicating that the CL‐20 cage was broken, since all carbons are part of the heterocyclic cage. Under aerobic conditions, abiotic degradation rates of RDX were generally slower (0 < k < 0.032 d−1) than abiotic CL‐20 degradation rates. In biologically active soil microcosms amended with glucose aerobic RDX degradation rates varied between 0.010 and 0.474 d−1 Biodegradation was a key factor in determining the environmental fate of RDX, while a combination of biotic and abiotic processes was important with CL‐20. Our data suggest that CL‐20 should be less recalcitrant than RDX in aerobic soils.
Chemical and Physical Changes Following Co‐Composting of Beef Cattle Feedlot Manure with Phosphogypsum
Authors: Zvomuya Francis , Larney Francis J. , Nichol Connie K. , Olson Andrew F. , Miller Jim J. , DeMaere Paul R.
Published: November 2005

Nitrogen (N) loss during beef cattle (Bos taurus) feedlot manure composting may contribute to greenhouse gas emissions and increase ammonia (NH3) in the atmosphere while decreasing the fertilizer value of the final compost. Phosphogypsum (PG) is an acidic by‐product of phosphorus (P) fertilizer manufacture and large stockpiles currently exist in Alberta. This experiment examined co‐composting of PG (at rates of 0, 40, 70, and 140 kg PG Mg−1 manure plus PG dry weight) with manure from feedlot pens bedded with straw or wood chips. During the 99‐d composting period, PG addition reduced total nitrogen (TN) loss by 0.11% for each 1 kg Mg−1 increment in PG rate. Available N at the end of composting was significantly higher for wood chip–bedded (2180 mg kg−1) than straw‐bedded manure treatments (1820 mg kg−1). Total sulfur (TS) concentration in the final compost increased by 0.19 g kg−1 for each 1 kg Mg−1 increment in PG rate from 5.2 g TS kg−1 without PG addition. Phosphogypsum (1.6 g kg−1 P) addition had no significant effect on total phosphorus (TP) concentration of the final composts. Results from this study demonstrate the potential of PG addition to reduce overall N losses during composting. The accompanying increase in TS content has implications for use of the end‐product on sulfur‐deficient soils. Co‐composting feedlot manure with PG may provide an inexpensive and technologically straightforward solution for managing and improving the nutrient composition of composted cattle manure.
Transport and Fate of Nitrate and Pesticides
Authors: Puckett Larry J. , Hughes W. Brian
Published: November 2005

There is continuing concern over potential impacts of widespread application of nutrients and pesticides on ground‐ and surface‐water quality. Transport and fate of nitrate and pesticides were investigated in a shallow aquifer and adjacent stream, Cow Castle Creek, in Orangeburg County, South Carolina. Pesticide and pesticide degradate concentrations were detected in ground water with greatest frequency and largest concentrations directly beneath and downgradient from the corn (Zea mays L.) field where they were applied. In almost all samples in which they were detected, concentrations of pesticide degradates greatly exceeded those of parent compounds, and were still present in ground waters that were recharged during the previous 18 yr. The absence of both parent and degradate compounds in samples collected from deeper in the aquifer suggests that this persistence is limited or that the ground water had recharged before use of the pesticide. Concentrations of NO−3 in ground water decreased with increasing depth and age, but denitrification was not a dominant controlling factor. Hydrologic and chemical data indicated that ground water discharges to the creek and chemical exchange takes place within the upper 0.7 m of the streambed. Ground water had its greatest influence on surface‐water chemistry during low‐flow periods, causing a decrease in concentrations of Cl−, NO−3, pesticides, and pesticide degradates. Conversely, shallow subsurface drainage dominates stream chemistry during high‐flow periods, increasing stream concentrations of Cl−, NO−3, pesticides, and pesticide degradates. These results point out the importance of understanding the hydrogeologic setting when investigating transport and fate of contaminants in ground water and surface water.
Laboratory Evaluation of Thermophilic‐Anaerobic Digestion to Produce Class A Biosolids. 2. Inactivation of Pathogens and Indicator Organisms in a Continuous‐Flow Reactor Followed by Batch Treatment
Authors: Aitken Michael D. , Sobsey Mark D. , Shehee Mina , Blauth Kimberly E. , Hill Vincent R. , Farrell Joseph B. , Nappier Sharon P. , Walters Glenn W. , Crunk Phillip L. , Van Abel Nicole
Published: November 2005

Thermophilic‐anaerobic digestion in a single‐stage, mixed, continuous‐flow reactor is not approved in the United States as a process capable of producing Class A biosolids for land application. This study was designed to evaluate the inactivation of pathogens and indicator organisms in such a reactor followed by batch treatment in a smaller reactor. The combined process was evaluated at 53°C with sludges from three different sources and at 51 and 55°C with sludge from one of the sources. Feed sludge to the continuous‐flow reactor was spiked with the pathogen surrogates Ascaris suum and vaccine‐strain poliovirus. Feed and effluent were analyzed for these organisms and for indigenous Salmonella spp., fecal coliforms, Clostridium perfringens spores, and somatic and male‐specific coliphages. No viable Ascaris eggs were observed in the effluent from the continuous reactor at 53 or 55°C, with greater than 2‐log removals across the digester in all cases. Approximately 2‐log removal was observed at 51°C, but all samples of effluent biosolids contained at least one viable Ascaris egg at 51°C. No viable poliovirus was found in the digester effluent at any of the operating conditions, and viable Salmonella spp. were measured in the digester effluent in only one sample throughout the study. The ability of the continuous reactor to remove fecal coliforms to below the Class A monitoring limit depended on the concentration in the feed sludge. There was no significant removal of Clostridium perfringens across the continuous reactor under any condition, and there also was limited removal of somatic coliphages. The removal of male‐specific coliphages across the continuous reactor appeared to be related to temperature. Overall, at least one of the Class A pathogen criteria or the fecal coliform limit was exceeded in at least one sample in the continuous‐reactor effluent at each temperature. Over the range of temperatures evaluated, the maximum time required to meet the Class A criteria by batch treatment of the continuous‐reactor effluent was 1 hour for Ascaris suum and Salmonella spp. and 2 hours for fecal coliforms.
Modeling Depth Filtration of Activated Sludge Effluent Using a Compressible Medium Filter
Authors: Caliskaner Onder , Tchobanoglous George
Published: November 2005

A new filter, using a compressible‐filter medium, has been evaluated for the filtration of secondary effluent. The ability to adjust the properties of the filter medium by altering the degree of the medium compression is a significant departure from conventional depth‐filtration technology. Unlike conventional filters, it is possible to optimize the performance of the compressible‐medium filter (CMF) by adjusting the medium properties (i.e., collector size, porosity, and depth) to respond to the variations in influent quality.    Because existing filter models cannot be used to predict the performance of the CMF, a new predictive model has been developed to describe the filtration performance of the CMF and the effect of medium‐compression ratio. The model accounts for the fact that the properties of the filter medium change with time and depth. The model, developed for heterodisperse suspensions and variable influent total suspended solids concentrations, can be used to predict all possible phases of filtration (i.e., ripening, constant removal, and breakthrough). A hyperbolic‐type, second‐order, nonlinear, partial‐differential equation was derived to model the CMF. The equation was solved using the finite‐difference numerical method. The accuracy of the numerical method was tested by a sensitivity analysis and a convergence test. The model is first‐order accurate with respect to medium depth and time.    Field data were obtained for the filtration of settled secondary effluent using a CMF with a capacity of 1200 m3/d. Model predictions were compared with observed performance from filter runs conducted at medium‐compression ratios between 15 and 40% and filtration rates from 410 to 820 L/m2·min. The difference between the observed and the predicted values was found to be within 0 to 15%.
The Human Side of the Digital Divide: Media Experience as the Border of Communication Satisfaction with Email
Authors: Ishii Kumi
Published: November 2005

Electronic mail (email) has rapidly become one of the most prominent communication media, and a substantial amount of information is processed by it in the contemporary workplace. It is well known that digital technology produces a “digital divide.” In addition, it is well examined that the digital divide produces cognitive differences (e.g., knowledge gaps) among users. Yet, little is known about affective disparities. In addition, few studies on the digital divide were undertaken in organizational setting. This study considers the human side of the digital divide in an organizational setting and investigates if the digital divide exists in the workplace by examining multiple dimensions of communication satisfaction. The data from 303 university employees indicates that email experience differentiates communication satisfaction with amount of email and email use for equivocal tasks.
Cost‐Effective Management of bEnign Positional Vertigo Using Canalith Repositioning
Authors: Li John C. , Li Celeste J. , Epley John , Weinberg Lynn
Published: November 2005

OBJECTIVE

The misdiagnosis and inappropriate treatment of benign positional vertigo have resulted in significant costs to the medical system. In the current medical‐economic climate, there is an increased emphasis on cost control. Recent studies have shown that the canalith repositioning procedure (CRP) is effective; the next step is to show the impact of CRP in cost‐effective management of benign positional vertigo.

METHODS

Forty‐six of 100 patients who underwent CRP for benign positional vertigo responded to a survey regarding the financial impact of their disease. They were asked to subjectively estimate the sum of all disease‐related expenses. Objective substantiation of this number was estimated by tabulating physician data, laboratory data, and failed treatment costs.

RESULTS

The subjective figure totaled $2684.74 per individual. Summation of the tangible objective figures yielded $2009.63 per patient, corroborating the subjective figure.

CONCLUSIONS

Because CRP is a relatively simple procedure that can obviate many wasted expenses in most patients, we believe that it is very cost‐effective and should be incorporated into routine practice.
Endolymphatic Mastoid Shunt: A Reevaluation of Efficacy
Authors: Welling D. Bradley , Nagaraja H. N.
Published: November 2005

OBJECTIVES

The main goal of this paper was to statistically reevaluate the efficacy of the endolymphatic shunt procedure for Meniere's disease.

METHODS

Thomsen et al (Arch Otolaryngol 1981; 107:271‐7) reported on the placebo effect in surgery for Meniere's disease in a controlled doubleblind study. Thirty patients with typical Meniere's disease in whom medical treatment failed participated in the study. A placebo‐controlled blinded surgical study has not since been replicated. We performed a retrospective statistical analysis using data extracted from the published report and reanalyzed it using both the original and new statistical measures and techniques.

RESULTS

The original conclusions drawn by Thomsen et al differed considerably from ours in 5 key areas, including postoperative vertigo, nausea and vomiting, tinnitus, and combined score.

CONCLUSIONS

This analysis strongly supports the effectiveness of the endolymphatic shunt in the management of Meniere's disease and refutes the placebo effect previously proposed.
Conductive Hearing Loss Associated with Pressure Equalization Tubes
Authors: Estrem Scott A. , Batra Pete S.
Published: November 2005

Pressure equalization (PE) tube placement traditionally has been used to lessen conductive hearing loss with chronic middle ear effusion. It is assumed that the small diameter of the tube should not interfere with the conduction of sound. In this article we present 5 patients in whom placement of a PE tube resulted in significantly worse conductive hearing. Occlusion of the PE tube with cigarette paper or Gelfoam improved hearing, as documented with audiometry. The average conductive hearing losses attributable to the ventilation tube for this series of patients were 22, 17, 15, 13, 4, and 10 dB at the frequencies of 250, 500, 1000, 2000, 4000, and 8000 Hz, respectively. This amount of change attributable to PE tubes in this small selection of patients is much greater than would be commonly appreciated. We conclude that the opening in the tympanic membrane provided by PE tubes can potentially result in a significant conductive hearing loss. Discussion includes those conditions in which reduced hearing may be more likely to occur.
Tall Cell Variant: An Aggressive Form of Papillary Thyroid Carcinoma
Authors: Prendiville Stephen , Burman Kenneth D. , Ringel Matthew D. , Shmookler Barry M. , Deeb Ziad E. , Wolfe Katherine , Azumi Norio , Wartofsky Leonard , Sessions Roy B.
Published: November 2005

Twenty‐four cases of the tall cell variant (TCV), a subset of papillary thyroid carcinoma, were identified in a group of 624 patients with thyroid cancer. All pathology specimens were reviewed, and each patient's carcinoma was categorized according to characteristics on presentation, local recurrence, distant metastases, follow‐up, and tumor‐related mortality. The TCV group was compared with a historical control group (Mazzaferri and Jhiang: 1355 patients). The TCV group had a statistically higher percentage of stage 3 and 4 carcinoma, extrathyroidal invasion, and tumor size less than 1.5 cm than the control group. There was no statistical relationship between age greater than 50 years and stage in the TCV group. No relationship could be found between TCV histology and recurrence or mortality. These findings, combined with those of studies that link stage on presentation to poor outcomes, have led to our conclusion that TCV is an aggressive malignancy warranting appropriate treatment and close follow‐up.
Comparison of Postoperative Pain between Laser‐Assisted Uvulopalatoplasty, Uvulopalatopharyngoplasty, and Radiofrequency Volumetric Tissue Reduction of the Palate
Authors: Troell Robert J. , Powell Nelson B. , Riley Robert W. , Li Kasey K. , Guilleminault Christian
Published: November 2005

OBJECTIVES

This study compares the posttreatment discomfort between laser‐assisted uvulopalatoplasty (LAUP), uvulopalatopharyngoplasty (UPPP), and radiofrequency volumetric tissue reduction (RFVTR) of the palate through the use of visual analog pain scales and a quantitative assessment of the analgesic medication taken.

METHODS

In one group, LAUP (n = 10) or UPPP (n = 9) was used to treat patients' snoring or sleep‐disordered breathing (SDB), and the other group underwent RFVTR (n = 22).

RESULTS

The mean numbers of days with pain after RFVTR, LAUP, and UPPP were 2.6, 13.8, and 14.3 days, respectively. Narcotic analgesics were required in the RFVTR, LAUP and UPPP groups in 9%, 100%, and 100% of the subjects, respectively. The mean number of these days requiring narcotic pain medications for RFVTR, LAUP, and UPPP was 0.2, 11.8, and 12.4 days, whereas the total narcotic equivalent was 0.3, 7.4 and 29.6 days, respectively.

CONCLUSION

RFVTR of the soft palate produced less posttreatment pain than LAUP or UPPP. LAUP and UPPP appeared to show little difference in the severity or duration of posttreatment discomfort.
Surgery and Obstructive Sleep Apnea: Long‐Term Clinical Outcomes
Authors: Riley Robert W. , Powell Nelson B. , Li Kasey K. , Troell Robert J. , Guilleminault Christian
Published: November 2005

OBJECTIVE

Outcome data on the surgical treatment of obstructive sleep apnea are, in general, based on short‐term follow‐up (<6‐9 months). This examination was undertaken to assess long‐term results.

METHODS

Forty patients who underwent soft tissue and skeletal surgery were the subjects of this review. Methods of evaluation included polysomnographic variables (respiratory disturbance index [RDI], low oxyhemoglobin desaturation [LSATT]), body mass index, quality‐of‐life assessments, roentgenographic analysis, and complications. Statistical analysis used the SAS 6.12 system.

RESULTS

Thirty‐six of 40 patients (90%) showed long‐term clinical success. The mean preoperative RDI, nasal continuous positive airway pressure RDI, and long‐term RDI were 71.2 ± 27.0, 7.6 ± 5.2 and 7.6 ± 5.1, respectively. The mean preoperative LSAT, nasal continuous positive airway pressure LSAT, and long‐term LSAT were 67.5% ± 14.8%, 87.1% ± 3.2%, and 86.3% ± 3.9%, respectively. The mean follow‐up was 50.7 ± 31.9 months. The patients showed a statistically significant long‐term weight gain (P = 0.0002) compared with their 6‐month postoperative level (body mass index 31.4 ± 6.7 vs 32.2 ± 6.3). There was a positive correlation with the amount of skeletal advancement and clinical outcome.

CONCLUSION

Comprehensive evaluation and surgical treatment can result in successful long‐term clinical outcome.