bluuebunny/crossref_metadata_2025 huggingface dataset:
Antidepressants at environmentally relevant concentrations affect predator avoidance behavior of larval fathead minnows (Pimephales promelas)
Authors: Painter Meghan M. , Buerkley Megan A. , Julius Matthew L. , Vajda Alan M. , Norris David O. , Barber Larry B. , Furlong Edward T. , Schultz Melissa M. , Schoenfuss Heiko L.
Published: April 2009

The effects of embryonic and larval exposure to environmentally relevant (ng/L) concentrations of common antidepressants, fluoxetine, sertraline, venlafaxine, and bupropion (singularly and in mixture) on C-start escape behavior were evaluated in fathead minnows (Pimephales promelas). Embryos (postfertilization until hatching) were exposed for 5 d and, after hatching, were allowed to grow in control well water until 12 d old. Similarly, posthatch fathead minnows were exposed for 12 d to these compounds. High-speed (1,000 frames/s) video recordings of escape behavior were collected and transferred to National Institutes of Health Image for frame-by-frame analysis of latency periods, escape velocities, and total escape response (combination of latency period and escape velocity). When tested 12 d posthatch, fluoxetine and venlafaxine adversely affected C-start performance of larvae exposed as embryos. Conversely, larvae exposed for 12 d posthatch did not exhibit altered escape responses when exposed to fluoxetine but were affected by venlafaxine and bupropion exposure. Mixtures of these four antidepressant pharmaceuticals slowed predator avoidance behaviors in larval fathead minnows regardless of the exposure window. The direct impact of reduced C-start performance on survival and, ultimately, reproductive fitness provides an avenue to assess the ecological relevance of exposure in an assay of relatively short duration.
The toxicity of Roundup Original Max® to 13 species of larval amphibians
Authors: Relyea Rick A. , Jones Devin K.
Published: April 2009

With the increased use of glyphosate-based herbicides (marketed under several names, including Roundup® and Vision®), there has been a concomitant increased concern about the unintended impacts that particular formulations containing the popular surfactant polyethoxylated tallowamine (POEA) might have on amphibians. Published studies have examined a relatively small number of anuran species (primarily from Australia and eastern North America) and, surprisingly, no species of salamanders. Using a popular formulation of glyphosate (Roundup Original Max®), the goal of the present study was to conduct tests of lethal concentrations estimated to kill 50% of a population after 96 h (LC5096-h) on a wider diversity of species from both eastern and western North America. Tests were conducted on nine species of stage 25, larval anurans from three families (Ranidae: Rana pipiens, R. clamitans, R. sylvatica, R. catesbeiana, R. cascadae; Bufonidae: Bufo americanus, B. boreas; and Hylidae: Hyla versicolor, Pseudacris crucifer) and four species of larval salamanders from two families (Ambystomatidae: Ambystoma gracile, A. maculatum, A. laterale; and Salamandridae: Notophthalmus viridescens). For the nine species of larval anurans, LC5096-h values ranged from 0.8- to 2.0-mg acid equivalents per liter with relatively little pattern in differential sensitivity among the species or families. The four species of larval salamanders were less sensitive than the anurans, with LC5096-h values ranging from 2.7- to 3.2-mg acid equivalents per liter and no substantial differences among the species of salamanders. This work substantially increases the available data on amphibian sensitivity to glyphosate formulations that include either POEA surfactants or the equally moderately to highly toxic surfactants of Roundup Original Max and should be useful for improving future risk assessments.
The Impact of the Stone Age Diet on Gingival Conditions in the Absence of Oral Hygiene
Authors: Baumgartner Stefan , Imfeld Thomas , Schicht Olivier , Rath Christian , Persson Rigmor E. , Persson G. Rutger
Published: April 2009

Background: The objective of this study was to assess the oral microbiota and clinical data in subjects without access to traditional oral hygiene methods and who ate a diet available in the Stone Age.

Methods: Ten subjects living in an environment replicating the Stone Age for 4 weeks were enrolled in this study. Bleeding on probing (BOP), gingival and plaque indices, and probing depth (PD) were assessed at baseline and at 4 weeks. Microbiologic samples were collected at the mesio‐buccal subgingival aspects of all teeth and from the dorsum of the tongue and were processed by checkerboard DNA‐DNA hybridization methods.

Results: No subject had periodontitis. Mean BOP decreased from 34.8% to 12.6% (P <0.001). Mean gingival index scores changed from 0.38 to 0.43 (not statistically significant) and mean plaque scores increased from 0.68 to 1.47 (P <0.001). PD at sites of subgingival sampling decreased (mean difference: 0.2 mm; P <0.001). At week 4, the total bacterial count was higher (P <0.001) for 24 of 74 species, including Bacteroides ureolyticus, Eikenella corrodens, Lactobacillus acidophilus, Capnocytophaga ochracea, Escherichia coli, Fusobacterium nucleatum naviforme, Haemophilus influenzae, Helicobacter pylori, Porphyromonas endodontalis, Staphylococcus aureus (two strains), Streptococcus agalactiae, Streptococcus anginosis, and Streptococcus mitis. Bacterial counts from tongue samples were higher at baseline (P <0.001) for 20 species, including Tannerella forsythia (previously T. forsythensis), Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans; serotype a), and Streptococcus spp.

Conclusions: The experimental gingivitis protocol is not applicable if the diet (e.g., Stone Age) does not include refined sugars. Although plaque levels increased, BOP and PD decreased. Subgingival bacterial counts increased for several species not linked to periodontitis, whereas tongue bacterial samples decreased during the study period.
A Prospective Multicenter 5‐Year Radiographic Evaluation of Crestal Bone Levels Over Time in 596 Dental Implants Placed in 192 Patients
Authors: Cochran David L. , Nummikoski Pirkka V. , Schoolfield John D. , Jones Archie A. , Oates Thomas W.
Published: April 2009

Background: Dental implants have been used to replace missing teeth to provide function and esthetics. One goal of such restorations is to maintain host tissue around the implants. The purpose of this prospective multicenter human clinical trial was to evaluate radiographic marginal bone levels around non‐submerged hollow cylindrical and solid‐screw implants for 5 years after loading.

Methods: Patients older than 18 years of age with sufficient native bone to surround a dental implant without imposing on a vital structure were recruited at five sites. Solid‐screw or hollow‐cylinder implants with a titanium plasma–sprayed implant surface were placed in the anterior maxilla or anterior mandible and restored with fixed restorations. Baseline radiographs were taken at the time of implant placement. Subsequent radiographs were taken at the time of final prosthesis placement, at 6 months after prosthesis placement, and annually from prosthesis placement for 5 years.

Results: The results of 596 implants in 192 patients at five international sites revealed that clinically significant remodeling of the marginal bone occurred during the first 6 months after implant placement, with a mean (± SD) marginal bone loss of 2.44 ± 1.20 mm. After that, clinically insignificant mean changes in the bone were observed. Overall, 0.22 ± 0.42 mm of bone loss occurred between the time of prosthesis placement and 1‐year postloading. Between 1‐year postloading and the last 5‐year recall, 0.18 ± 0.88 mm bone loss occurred. Because 2.84 ± 1.63 mm of bone loss occurred between implant placement and the 5‐year postloading follow‐up, 86% of the total mean bone loss over the course of 5 years was accounted for at the time of prosthesis placement. These same trends occurred if the data were analyzed with regard to implant design (solid screw and hollow cylinder), type of restoration (single and multiple), and length of implant (8 to 10, 12, and 14 to 16 mm).

Conclusions: These data demonstrate that, in general, clinically significant marginal bone remodeling occurred between the time of implant placement and final prosthesis placement around one‐stage non‐submerged titanium implants with a titanium plasma–sprayed surface. Subsequent to that, bone loss observed around implants up to 5 years postloading was minimal. These results suggest that the factors that influence early healing around implants are significantly different from those that affect later marginal bone remodeling.
Decreased Interleukin‐2 Responses to Fusobacterium nucleatum and Porphyromonas gingivalis in Generalized Aggressive Periodontitis
Authors: Borch Tanja Skuldbøl , Løbner Morten , Bendtzen Klaus , Holmstrup Palle , Nielsen Claus Henrik
Published: April 2009

Background: Compromised T‐cell responses to periodontal pathogens may contribute to the pathogenesis of generalized aggressive periodontitis (GAgP). In this study, we attempted to characterize T‐helper cell (Th1, Th2, and Th17) responses in patients with GAgP and healthy controls upon stimulation with disease‐relevant pathogens.

Methods: Mononuclear cells (MNCs) from 10 white patients with GAgP and 10 white controls were stimulated with Porphyromonas gingivalis American Type Culture Collection (ATCC) 33277 (Pg), Prevotella intermedia ATCC 25611, Fusobacterium nucleatum ATCC 49256 (Fn), and similar bacteria isolated from the participants' inherent oral flora. Tetanus toxoid (TT) was used as control antigen. The resulting production of interferon‐gamma (IFN‐γ) and interleukin (IL)‐2, −4, −5 and −17 and the induced proliferation of CD4+ T cells were measured.

Results: MNCs from patients with GAgP exhibited decreased IL‐2 responses to Pg and Fn. No difference was observed between patients with GAgP and controls with regard to CD4+ T‐cell proliferation or the production of IFN‐γ and IL‐4, −5, and −17, irrespective of whether type strains or bacteria isolated from the participants' oral cavity were used for stimulation. Moreover, similar proliferative and cytokine responses to TT were observed. Notably, smoking patients with GAgP exhibited significantly lower IFN‐γ responses to the bacteria and to TT than non‐smoking patients or controls.

Conclusions: The decreased IL‐2 responses of patients with GAgP to Pg and Fn combined with adequate IL‐2 responses to TT suggest an impaired antigen‐specific T‐cell reactivity with periodontal pathogens in GAgP. The decreased IFN‐γ responses of smokers within the patient group suggest that smoking may aggravate this impairment.
Temporal Association of Elevated C‐Reactive Protein and Periodontal Disease in Men
Authors: Yoshii Saori , Tsuboi Shinji , Morita Ichizo , Takami Yuko , Adachi Keiko , Inukai Junko , Inagaki Koji , Mizuno Kinichiro , Nakagaki Haruo
Published: April 2009

Background: Most studies on the relationship between serum C‐reactive protein (CRP) and periodontal disease have been cross‐sectional. In this study, we investigated the temporal association between CRP and periodontal disease by following a large number of subjects for 1 year.

Methods: We studied 11,162 men in Nagoya, Japan, who had an initial dental examination as part of a complete physical examination and then underwent the same examination 1 year later. For the 4,997 men without periodontal disease at baseline, logistic regression analysis was performed to examine the relationship between baseline CRP and periodontal disease 1 year later, adjusting for age, body mass index, glycosylated hemoglobin A1c level, and smoking status. Similarly, logistic regression analysis was performed to examine the relationship between periodontal disease at baseline and CRP 1 year later for the 10,376 men with normal baseline CRP, adjusting for the same confounding factors.

Results: Among men without high CRP at baseline, periodontal disease at baseline correlated to CRP 1 year later. The odds ratio was 1.336 (95% confidence interval [CI]: 1.115 to 1.674). However, in the men without periodontal disease, no significant correlations were seen with baseline CRP or periodontal disease 1 year later. The odds ratio was 1.163 (95% CI: 0.894 to 1.513).

Conclusion: Periodontal disease increased the risk for high serum CRP levels in men after 1 year of follow‐up.
Comparative Immunohistochemical Study of the Distribution of Fibronectin in Healthy and Diseased Root Surfaces
Authors: Komboli Mado G. , Kodovazenitis George J. , Katsorhis Theodore A.
Published: April 2009

Background: Periodontal disease is an inflammatory process which may result in damage to and/or loss of tooth‐supporting tissues, including bone, cementum, and periodontal ligament. Significant evidence supports a strong correlation between periodontitis and diseased or altered cementum. The aim of this study was to investigate the presence and distribution of fibronectin in normal human cementum and to determine whether its distribution is altered in periodontitis.

Methods: Five healthy and 10 periodontally affected teeth were collected. Following fixation and demineralization, specimens were embedded in paraffin, sectioned, and exposed to antibodies against fibronectin. Stained sections were assessed using light microscopy.

Results: The distribution of fibronectin, in the form of fibrils, in normal cementum was uniform in the whole cementum mass. In recession cementum, fibronectin appeared to lose its fibrillar morphology or to be completely amorphous on the whole cementum mass. Fibronectin showed variation in its distribution and fibrillar structure in pocket cementum; its absence from the cementum surface is characteristic. In the cementum apical to the pocket, fibronectin showed normal fibril structures, similar to normal cementum.

Conclusions: Changes in cementum due to periodontitis include changes in the distribution and morphology of fibronectin. These changes may influence the ability for regeneration and connective tissue attachment onto periodontally affected root surfaces.
The Constitutive Activation of Extracellular Signal‐Regulated Kinase 1 and 2 in Periodontal Ligament Nerve Fibers
Authors: Korkmaz Yüksel , Bloch Wilhelm , Klinz Franz‐Josef , Kübler Alexander C. , Schneider Kurt , Zimmer Stefan , Addicks Klaus , Raab Wolfgang H.‐M.
Published: April 2009

Background: The extracellular signal‐regulated kinases 1 and 2 (ERK1/2) have been implicated in the inflammation‐dependent sensitization of nociceptors. Because the periodontal ligament (PDL) contains numerous nociceptors and mechanoceptors, phosphorylation of ERK1/2 was investigated in nerve fibers of the PDL to elucidate the role of constitutive local activation of ERK1/2 in peripheral sensitization.

Methods: Decalcified free‐floating sections of rat molars with PDL were incubated using total (t)‐ERK1/2 and phosphorylated (p)‐ERK1/2 antibodies. For identification of nerve fibers in the PDL, double staining was performed using protein gene product 9.5 (PGP 9.5) with p‐ERK1/2. To test whether p‐ERK1/2 activated in sensory and mechanoreceptive terminals, double incubations were performed using p‐ERK1/2 with calcitonin gene‐related peptide (CGRP) and with calretinin. Labeled nerve fibers were quantified by the point‐counting method.

Results: In cervical, midroot, and apical zones of the PDL, t‐ERK1/2– and p‐ERK1/2–labeled nerve fibers were found in close association with blood vessels. The p‐ERK1/2–labeled free nerve fibers were often detected in cervical and apical areas of the PDL. In nerve fibers of the PDL, p‐ERK1/2 was colocalized with PGP 9.5, CGRP, and calretinin.

Conclusions: The perivascular distribution of t‐ERK1/2 and p‐ERK1/2 in nerve fibers in the PDL is compatible with a role for the constitutive activation of ERK1/2 in the neural regulation of blood vessels in the PDL. The colocalizations of p‐ERK1/2 with CGRP and calretinin indicate that ERK1/2 is constitutively activated in a subpopulation of sensory and mechanoreceptive nerve terminals in the PDL.
Cytokine Gene Polymorphisms Associated With Rheumatoid Arthritis and Periodontitis in Japanese Adults
Authors: Kobayashi Tetsuo , Murasawa Akira , Ito Satoshi , Yamamoto Kouji , Komatsu Yasutaka , Abe Asami , Sumida Takayuki , Yoshie Hiromasa
Published: April 2009

Background: Cytokines play a major role in the pathogenesis of rheumatoid arthritis (RA) and periodontitis. Both diseases were previously shown to be partly influenced by cytokine gene polymorphisms. Therefore, we evaluated whether the distributions of the cytokine genotypes were unique to subjects with both diseases.

Methods: The study subjects consisted of Japanese adults with RA (RA group; n = 153), periodontitis only (P group; n = 117), and healthy individuals (H group; n = 108). Clinical periodontal condition was defined by measurements of probing depth, clinical attachment level, and bleeding on probing. Genomic DNA was isolated from peripheral blood and analyzed for the determination of 16 gene polymorphisms encoding interleukin (IL)‐1, −2, −4, −6, and −10, tumor necrosis factor‐alpha, and transforming growth factor‐beta 1.

Results: The frequency of patients with RA who exhibited periodontitis was 89.5% (RA + P group; n = 137). No significant differences were observed in any of the frequencies of cytokine genotypes and alleles among the subject groups. After adjustment for age, gender, and smoking status, multiple logistic regression analysis revealed a significant difference in the distribution of IL‐1B +3954 genotypes between RA + P and P groups (P = 0.006) and between RA + P and H groups (P = 0.008).

Conclusion: Japanese individuals with RA and periodontitis may exhibit different distributions of IL‐1B +3954 genotypes than healthy controls and subjects with periodontitis only.
Potential of Bioactive Glass Particles of Different Size Ranges to Affect Bone Formation in Interproximal Periodontal Defects in Dogs
Authors: Felipe Maria Emília M.C. , Andrade Patrícia F. , Novaes Arthur B. , Grisi Márcio F.M. , Souza Sérgio L.S. , Taba Mário , Palioto Daniela B.
Published: April 2009

Background: The aim of this study was to compare the potential of bioactive glass particles of different size ranges to affect bone formation in periodontal defects, using the guided tissue regeneration model in dogs.

Methods: In six dogs, 2‐wall intrabony periodontal defects were surgically created and chronified on the mesial surfaces of mandibular third premolars and first molars bilaterally. After 1 month, each defect was randomly assigned to treatment with bioabsorbable membrane in association with bioactive glass with particle sizes between 300 and 355 μm (group 1) or between 90 and 710 μm (group 2), membrane alone (group 3), or negative control (group 4). The dogs were sacrificed 12 weeks after surgeries, and histomorphometric measurements were made of the areas of newly formed bone, new mineralized bone, and bioactive glass particle remnants.

Results: With regard to the area of bioactive glass particle remnants, there was a statistically significant difference between groups 1 and 2, favoring group 1. There were greater areas of mineralized bone in groups 1 and 2 compared to groups 3 and 4 (P <0.05).

Conclusion: The bioactive glass particles of small size range underwent faster resorption and substitution by new bone than the larger particles, and the use of bioactive glass particles favored the formation of mineralized bone.
Update on the Changing Numbers and Distribution of Periodontists
Authors: Waldman H. Barry , Chaudhry Ramiz A.
Published: April 2009

A review of the 2006 and past American Dental Association (ADA) studies on the distribution of dentists provides information on the evolving number of periodontists. Despite an overall increase in the number of periodontists, major differences continue in practitioner/population ratios in different geographic areas. As in past reviews, suggestions are offered for efforts by the ADA and/or the American Academy of Periodontology to draw attention to the limited numbers of periodontists in particular regions and states; to increase efforts to educate the public on the need and value of periodontal services; and to increase the profession's awareness of the growing diversity in the nation's population and the need to modify and adjust its efforts to attract underserved populations with different familial, cultural, and educational backgrounds.
Biologic Assessment of Antiseptic Mouthwashes Using a Three‐Dimensional Human Oral Mucosal Model
Authors: Moharamzadeh Keyvan , Franklin Kirsty L. , Brook Ian M. , van Noort Richard
Published: April 2009

Background: The biologic safety profile of oral health care products is often assumed on the basis of simplistic test models such as monolayer cell culture systems. We developed and characterized a tissue‐engineered human oral mucosal model, which was proven to represent a potentially more informative and more clinically relevant alternative for the biologic assessment of mouthwashes. The aim of this study was to evaluate the biologic effects of alcohol‐containing mouthwashes on an engineered human oral mucosal model.

Methods: Three‐dimensional (3D) models were engineered by the air/liquid interface culture technique using human oral fibroblasts and keratinocytes. The models were exposed to phosphate buffered saline (negative control), triethylene glycol dimethacrylate (positive control), cola, and three types of alcohol‐containing mouthwashes. The biologic response was recorded using basic histology; a cell proliferation assay; 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide tissue‐viability assay; transmission electron microscopy (TEM) analysis; and the measurement of release of interleukin (IL)‐1β by enzyme‐linked immunosorbent assay.

Results: Statistical analysis showed that there was no significant difference in tissue viability among the mouthwashes, cola, and negative control groups. However, exposure to the positive control significantly reduced the tissue viability and caused severe cytotoxic epithelial damage as confirmed by histology and TEM analysis. A significant increase of IL‐1β release was observed with the positive control and, to a lesser extent, with two of the tested mouthrinses.

Conclusions: The 3D human oral mucosal model can be a suitable model for the biologic testing of mouthwashes. The alcohol‐containing mouthwashes tested in this study do not cause significant cytotoxic damage and may slightly stimulate IL‐1β release.
Proficiency testing as the key element in implementing EN13275 olfactometry
Authors: Van Harreveld Anton P. , Mannebeck Dietmar , Maxeiner Björn
Published: April 2009

The technical standard for dynamic olfactometry EN13725:2003 is now widely applied in testing of odours for environmental management purposes. Many laboratories working in this field apply QA/QC systems according to ISO17025 and are accredited under international accreditation, e.g. European Accreditation and NATA (Australia). One of the key elements of the EN13725 standard is the requirement to attain defined levels of statistical performance parameters, in particular Precision under repeatability conditions r and Accuracy A. For the reference odour n-butanol laboratories can establish these performance characteristics in-house, through internal QA/QC measurements. However, the real proof of the pudding is to demonstrate compliance with the requirements in externally organised blind proficiency testing. Proficiency testing for olfactometry has been used since the mid 1980s in the Netherlands and Germany. Currently international proficiency tests are organised by private firm Olfatec, under EN ISO/IEC 17020:2004 accreditation. In 2007 the most recent test was held, with 29 laboratories participating in the extended proficiency test using n-butanol. Of the participating laboratories 12 fully complied with the statistical performance criteria of EN13725. This result confirms that the EN13725 performance criteria are attainable in practice. It also shows that the majority of laboratories claiming to work according to EN13725 actually fail to do so on the key issue of the performance characteristics, a key element of the EN13725 standard. Even more worrying is that among the laboratories that fail to attain the required performance, many are accredited under ISO17025. Of 36 accredited laboratories for olfactometry in Europe only 12 have demonstrated compliance in 2007. This situation may create a false sense of security among users of the data produced, trusting that they can apply uncertainties according to EN13725 while in fact the uncertainty can be larger. It is therefore very important that corrective actions are implemented, and that the accreditation organisations monitor the implementation and also ensure that all laboratories claiming to work according to EN13725 under ISO17025 accreditation actually are able to attain the minimum criteria for precision and accuracy in successive proficiency tests. For users of olfactometry results it must be absolutely clear that a laboratory working according to EN13725 under ISO17025 accreditation will deliver results with a defined and satisfactory uncertainty. Such laboratories must be able to consistently pass proficiency tests for olfactometry. Accreditation bodies are the key guardians of this reasonable expectation..
Design and validation of a wind tunnel system for odour sampling on liquid area sources
Authors: Capelli L. , Sironi S. , Del Rosso R. , Céntola P.
Published: April 2009

The aim of this study is to describe the methods adopted for the design and the experimental validation of a wind tunnel, a sampling system suitable for the collection of gaseous samples on passive area sources, which allows to simulate wind action on the surface to be monitored. The first step of the work was the study of the air velocity profiles. The second step of the work consisted in the validation of the sampling system. For this purpose, the odour concentration of some air samples collected by means of the wind tunnel was measured by dynamic olfactometry. The results of the air velocity measurements show that the wind tunnel design features enabled the achievement of a uniform and homogeneous air flow through the hood. Moreover, the laboratory tests showed a very good correspondence between the odour concentration values measured at the wind tunnel outlet and the odour concentration values predicted by the application of a specific volatilization model, based on the Prandtl boundary layer theory. The agreement between experimental and theoretical trends demonstrate that the studied wind tunnel represents a suitable sampling system for the simulation of specific odour emission rates from liquid area sources without outward flow.
Instrumental characterization of odour: a combination of olfactory and analytical methods
Authors: Zarra T. , Naddeo V. , Belgiorno V. , Reiser M. , Kranert M.
Published: April 2009

Odour emissions are a major environmental issue in wastewater treatment plants and are considered to be the main cause of disturbance noticed by the exposed population. Odour measurement is carried out using analytical or sensorial methods. Sensorial analysis, being assigned to the “human sensor”, is the cause of a considerable uncertainty. In this study a correlation between analytical and sensorial methods was investigated. A novel tool was used to both define odour indexes and characterise the odour sources and the volatile substances that cause annoyance in a wastewater treatment plant, with the aim to remove the subjective component in the measure of the odours and define the induced impact. The sources and the main chemical substances responsible for the olfactory annoyances were identified. Around 36 different substances were detected, with more than half being smell relevant components as well as responsible. Dimethyl disulphide was identified as key compound. Results highlight the applicability of highly correlation between analytical and sensorial methods in odour emission monitoring.
Application of Eriobotrya japonica (Thunb.) Lindley (Loquat) seed biomass as a new biosorbent for the removal of malachite green from aqueous solution
Authors: Aksakal Özkan , Ucun Handan , Kaya Yusuf
Published: April 2009

A new biosorbent, Eriobotrya japonica (loquat) seed biomass, has been investigated in order to remove malachite green (MG) from aqueous solutions. The factors affecting the biosorption process such as adsorbent dosage, pH of the solution and contact time were studied. The results showed that as the dose of loquat seed increased, the percentage of MG biosorption decreased accordingly. The experimental data suggested that the maximum pH for efficient biosorption of MG was 5.0. The biosorption process was relatively fast and equilibrium was achieved after about 60 min. Freundlich and Langmuir adsorption isotherm models were used for adsorption equilibrium data and based on the Langmuir isotherm plots the maximum bisorption capacity (Qmax) value was calculated to be 57.47 mg/g at 20°C. The biosorption kinetics was determined by fitting pseudo-first-order and pseudo-second-order kinetic models to the experimental data, with the second-order model providing the best description of MG biosorption onto loquat seed. Various thermodynamic parameters such as free energy change ΔG0, enthalpy of sorption ΔH0 and entropy ΔS0 were estimated. The positive value of ΔH0 and negative values of ΔG0 show the sorption process is endothermic and spontaneous. The positive value of ΔS0 shows the increased randomness at the solid–liquid interface during the biosorption of dyes onto loquat seed.
Optimization of measurement campaigns for calibration of a conceptual sewer model
Authors: Kleidorfer M. , Möderl M. , Fach S. , Rauch W.
Published: April 2009

To simulate hydrological models of combined sewer systems an accurate calibration is indispensable. In addition to all sources of uncertainties in data collection due to the measurement methods itself, it is a key question which data has to be collected to calibrate a hydrological model, how long measurement campaigns should last and where that data has to be collected in a spatial distributed system as it is neither possible nor sensible to measure the complete system characteristics. In this paper we address this question by means of stochastic modelling. Using Monte Carlo Simulation different calibration strategies (selection of measurement sites, selection of rainfall-events) and different calibration parameters (overflow volume, number of overflows) are tested, in order to evaluate the influence on predicting the total overflow volume of the entire system. This methodology is applied in a case study with the aim to calculate the combined sewer overflow (CSO) efficiency. It can be shown that a distributed hydrological model can be calibrated sufficiently when calibration is done on 30% of all existing CSOs based on long-term observation. Event based calibration is limited possible to a limited extend when calibration events are selected carefully as wrong selection of calibration events can result in a complete failure of the calibration exercise.
Cost–benefit evaluation of a decentralized water system for wastewater reuse and environmental protection
Authors: Chen R. , Wang X. C.
Published: April 2009

This paper proposed a net benefit value (NBV) model for cost–benefit evaluation of wastewater treatment and reuse projects, and attention was mainly paid to decentralized systems which are drawing wide interests all over the world especially in the water-deficient countries and regions. In the NBV model, all the factors related to project costs are monetary ones which can be calculated by using traditional methods, while many of the factors related to project benefits are non-monetary ones which need sophisticated methods for monetization. In this regard, the authors elaborated several methods for monetization of the benefits from wastewater discharge reduction, local environment improvement, and human health protection. The proposed model and methods were applied for the cost–benefit evaluation of a decentralized water reclamation and reuse project in a newly developed residential area in Xi'an, China. The system with dual-pipe collection and grey water treatment and reuse was found to be economically ineligible (NBV > 0) when all the treated water is reused for artificial pond replenishment, gardening and other non-potable purposes by taking into account the benefit of water saving. As environmental benefits are further considered, the economic advantage of the project is more significant.
An investigation into advanced oxidation of three chlorophenoxy pesticides in surface water
Authors: MacAdam Jitka , Parsons Simon A.
Published: April 2009

The performance of Fenton's reagent in removing 2,4-D, MCPA and mecoprop from surface water has been evaluated here. Initial trials were undertaken at a pesticide concentration of 4.5 × 10−5 mol l−1 in deionised water at pH 3 and two different stoichiometric ratios of pesticide: Fe(II): H2O2 (1:1:10, 1:10:10) were evaluated. At the 1:1:10 ratio, ∼10 minutes were required to achieve a 50% removal of the pesticide. At the higher ratio the removal achieved after 1 minute, was >90%. Subsequent experiments studied the performance of Fenton (4.5 × 10−4 mol l−1 Fe(II): 4.5 × 10−4 mol l−1 H2O2) in surface water spiked with pesticides and the impact of pH on the rate and degree of pesticide degradation was investigated. The removal was significantly improved at pH 3 in comparison to pH 6.5. The effect of Fenton on DOC removal from surface water was followed. Experiments investigated the performance of Fenton at pesticide concentrations of 7.5 × 10−9 mol l−1 in surface water. Fenton was shown to be an effective treatment for removing low levels of pesticides from surface waters at pH 3 & 4.
Study of an organoclay for the sorption of dissolved organic compounds in the wastewaters from offshore platform operation
Authors: Scurtu C. , Leiknes T. , Helness H.
Published: April 2009

The goal of this research work was to find a sorbent able to selectively retain the harmful dissolved compounds in the wastewaters from offshore platform operation but not the carboxylic acids and to study the effects of the most important parameters on the sorption process. BTX compounds (benzene, toluene and p-xylene) and acetic acid were chosen as the representatives of the harmful compounds and carboxylic acids groups respectively since they are found in the highest concentrations. An organically modified clay was determined to be the most suitable sorbent, where performance was evaluated at different values of pH (3, 5 and 8), acetic acid concentration (0, 160 and 320 mg/l), salinity (0, 35 and 70 g/l) and temperature (20, 40 and 60°C). Results show that there is a sorption competition between BTX and acetic acid. Sorption of BTX compounds decreased with increasing initial acetic acid concentration and temperature, and increased proportionally with the salinity. Sorption of acetic acid, however, decreased with increasing pH, temperature and salinity.
Effects of exogenous spermidine on subcellular distribution and chemical forms of cadmium in Typha latifolia L. under cadmium stress
Authors: Tang C. F. , Zhang R. Q. , Wen S. Z. , Li C. F. , Guo X. F. , Liu Y. G.
Published: April 2009

The effects of foliar spraying with spermidine (Spd) on the subcellular distribution and chemical speciation of Cd in Typha latifolia L. in hydroponic system were investigated. Increased Cd concentration in the medium caused an increase of Cd concentration in all tissues and all subcellular fractions, with the highest Cd level occurring in roots, followed by rhizomes and leaves and the greatest accumulation was in cell walls, soluble fraction and organelle containing fractions ranked next, respectively. The greatest amount of Cd was found in the extraction of 1 mol·L−1 NaCl, followed by 2% HAC, deionized water, 80% ethanol, residues and the least in 0.6 mol·L−1 HCl. The subcellular distribution and different chemical forms of Cd both decreased after Spd application and were more inhibited by 0.25 than 0.50 mmol·L−1 Spd, especially in roots at 0.10 mmol·L−1 Cd treatment. It could be suggested that the retention of Cd in roots, cell walls binding with metal, metal ion compartmentation in vacuoles and Cd forms existing in undissolved and integrated with pectates and protein play an important role in Cd detoxification and Spd could enhance the tolerance of cattail to Cd stress.
Fault tree analysis for urban flooding
Authors: ten Veldhuis J. A. E. , Clemens F. H. L. R. , van Gelder P. H. A. J. M.
Published: April 2009

Traditional methods to evaluate flood risk generally focus on heavy storm events as the principal cause of flooding. Conversely, fault tree analysis is a technique that aims at modelling all potential causes of flooding. It quantifies both overall flood probability and relative contributions of individual causes of flooding. This paper presents a fault model for urban flooding and an application to the case of Haarlem, a city of 147,000 inhabitants. Data from a complaint register, rainfall gauges and hydrodynamic model calculations are used to quantify probabilities of basic events in the fault tree. This results in a flood probability of 0.78/week for Haarlem. It is shown that gully pot blockages contribute to 79% of flood incidents, whereas storm events contribute only 5%. This implies that for this case more efficient gully pot cleaning is a more effective strategy to reduce flood probability than enlarging drainage system capacity. Whether this is also the most cost-effective strategy can only be decided after risk assessment has been complemented with a quantification of consequences of both types of events. To do this will be the next step in this study.
Use of cyanopigment determination as an indicator of cyanotoxins in drinking water
Authors: Schmidt Wido , Petzoldt Heike , Bornmann Katrin , Imhof Lutz , Moldaenke Christian
Published: April 2009

The indicator function of the fluorescence signals of the cyanopigments phycocyanin and phycoerythrin as early warning parameters against the microcystins in drinking water was investigated by lab- and pilot-scale studies. The early warning function of the fluorescence signals was examined with regard to the signals' real-time character, their sensitivity and the behaviour of the cyanopigments in different treatment stages in comparison to microcystins. Fluorescence measurements confirmed the real-time character, since they can be carried out on-site without the pre-concentration of pigments. The limit of detection of phycoerythrin is determined at 0.7 μg/L and of phycocyanin at 5.3 μg/L respectively. If the pigment/microcystin ratio is known and calculated to be higher than 1, very low microcystin concentrations can be estimated by the fluorescence signals. The compared behaviour of both pigments and selected microcystins (MC-LR and MC-RR) during water treatment shows that pigments have an early warning function against microcystins in conventional treatment stages using pre-oxidation with permanganate, powdered-activated carbon and chlorination. In contrast, cyanopigments do not have an early warning function if chlorine dioxide is used as a pre-oxidant or final disinfection agent. In order to use pigment control measurements in drinking water treatment the initial pigment/toxin ratio of the raw water must be known.
Assessment of Shock Collars as Nonlethal Management for Wolves in Wisconsin
Authors: HAWLEY JASON E. , GEHRING THOMAS M. , SCHULTZ RONALD N. , ROSSLER SHAWN T. , WYDEVEN ADRIAN P.
Published: April 2009

ABSTRACT  Lethal control alone has not proven entirely effective in reducing gray wolf (Canis lupus) depredations in chronic problem areas. Opponents of lethal control argue that more emphasis should be placed on integrating nonlethal strategies into current management. However, few evaluations have tested the effectiveness of nonlethal options. We compared behavior patterns in terms of frequency and duration of bait station visits for 5 wolves fitted with shock collars to 5 control animals inhabiting wolf pack territories in northern Wisconsin during summers of 2003 and 2004. Shock collared wolves spent less time and made fewer visits to bait station zones than did control animals. During and after shocking, wolves shifted 0.7 km away from the bait station zone. Although active shocking did restrict wolf access, which could be useful in controlling wolf depredations during a limited time period, conditioning was not clearly demonstrated once shocking ceased. The effect of shock collar design and operation on long‐term conditioning and shock‐conditioned wolves on pack behavior needs further study. If long‐term conditioning is possible, shock collars could be used by wildlife managers as a nonlethal wolf management method in chronic problem areas where lethal control has proven ineffective.
Incorporating Genotyping Error Into Non‐Invasive DNA‐Based Mark—Recapture Population Estimates
Authors: KNAPP SHANNON M. , CRAIG BRUCE A. , WAITS LISETTE P.
Published: April 2009

ABSTRACT  Use of non‐invasive sources of DNA, such as hair or scat, to obtain a genetic mark for population estimates is becoming commonplace. Unfortunately, with such marks, potentials for genotyping errors and for the shadow effect have resulted in use of many loci and amplification of each specimen many times at each locus, drastically increasing time and cost of obtaining a population estimate. We proposed a method, the Genotyping Uncertainty Added Variance Adjustment (GUAVA), which statistically adjusts for genotyping errors and the shadow effect, thereby allowing use of fewer loci and one amplification of each specimen per locus. Using allele frequencies and estimates of genotyping error rates, we determined, for each pair of specimens, the probability that the pair was obtained from the same individual, whether or not their observed genotypes match. Using these probabilities, we reconstructed possible capture history matrices and used this distribution to obtain a population estimate. With simulated data, we consistently found our estimates had lower bias and smaller variance than estimates based on single amplifications in which genotyping error was ignored and that were comparable to estimates based on data free of genotyping errors. We also demonstrated the method on a fecal DNA data set from a population of red wolves (Canis rufus). The GUAVA estimate based on only one amplification genotypes compares favorably to the estimate based on consensus genotypes. A program to conduct the analysis is available from the first author for UNIX or Windows platforms. Application of GUAVA may allow for increased accuracy in population estimates at reduced cost.
Development of a Sightability Model for Low‐Density Elk Populations in Ontario, Canada
Authors: MCINTOSH TERESE E. , ROSATTE RICHARD C. , HAMR JOSEF , MURRAY DENNIS L.
Published: April 2009

ABSTRACT  The status of recolonizing elk (Cervus elaphus) populations in Ontario, Canada, is unclear and there is a need for effective population survey methods that can be applied locally. We sought to develop a sightability model that could account for both low densities of elk and dense forest cover in elk‐release areas in Ontario. We corrected winter aerial survey counts for sightability based on radiocollared animals known to be within observable distance of the aircraft. The multivariate model with the highest Akaike's Information Criterion corrected for sample size weight (wi = 0.427) revealed that elk group size, elk activity, dominant tree type, percent canopy cover, and percent conifer cover were significant predictors of elk sightability. The group‐size effect indicated that odds of sighting an elk increased by 1.353 (95% CI = 0.874‐3.689) for every additional elk. Standing elk were 5.033 (95% CI = 0.936‐15.541) times more likely to be observed than were resting elk, and those located in conifer cover were 0.013 (95% CI = 0.001‐0.278) times less likely to be sighted than elk in deciduous cover. Furthermore, elk located in >50% canopy cover and >50% conifer cover were 0.041 (95% CI = 0.003‐0.619) times and 0.484 (95% CI = 0.024‐9.721) times less likely to be sighted than elk in more open habitat, respectively. During model validation, observers detected 79% (113/143) of known elk in any given area, and population and sightability model predictions (±90% CI) overlapped with the population estimate, implying that our predictive model was robust. Unsurprisingly, large groups of elk in open habitat increased model precision, which highlights difficulties of counting Ontario elk in their northern range. We conclude that our model provided increased reliability for estimating elk numbers in Ontario compared to existing methods, and that the estimator may be useful in other areas where elk density is low and sightability is poor due to dense forest cover.
White‐Tailed Deer Foraging Habitat in Intensively Established Loblolly Pine Plantations
Authors: JONES PHILLIP D. , EDWARDS SCOTT L. , DEMARAIS STEPHEN
Published: April 2009

ABSTRACT Stand establishment techniques involving multiple herbicide applications are commonly used on industrial pine (Pinusspp.) plantations, raising concern over potential effects on white‐tailed deer (Odocoileus virginianus) forage production. We tested effects of stand establishment intensity on deer forage in 1–5‐year‐old loblolly pine (Pinus taeda) plantations (n= 4) in the East Gulf Coastal Plain of Mississippi using forage biomass and 4 measures of nutritional carrying capacity that reflected crude protein or digestible energy requirements for body maintenance and lactation. We also assessed whether forage biomass combined with a deer use rating effectively indexed nutritional carrying capacity. Treatments were combinations of mechanical site preparation, chemical site preparation (CSP), and herbaceous weed control (HWC). Total forage biomass and forage biomass of grasses and forbs were reduced by broadcast HWC. Forage biomass of vines was reduced both by CSP and by multiple broadcast HWC applications. Maintenance‐level carrying capacity estimates were reduced by broadcast HWC; lactation‐level estimates were higher in moderate‐intensity treatments. We believe the inherently low fertility of this region makes high‐quality forage production a more important management priority than increasing forage quantity. Chemical or chemical and mechanical site preparation combined with banded HWC provided the best option for providing both forage quality and quantity in open‐canopied, intensively managed pine plantations. Biomass‐based indices may be suitable for indexing protein‐based maintenance‐level carrying capacity in this region, but our results indicated they were not useful for indexing other carrying capacity estimates.