bluuebunny/crossref_metadata_2025 huggingface dataset:
The Future of Pediatrics: Mental Health Competencies for Pediatric Primary Care
Authors:   Committee on Psychosocial Aspects of Child and Family Health and Task Force on Mental Health
Published: June 2009

Pediatric primary care clinicians have unique opportunities and a growing sense of responsibility to prevent and address mental health and substance abuse problems in the medical home. In this report, the American Academy of Pediatrics proposes competencies requisite for providing mental health and substance abuse services in pediatric primary care settings and recommends steps toward achieving them. Achievement of the competencies proposed in this statement is a goal, not a current expectation. It will require innovations in residency training and continuing medical education, as well as a commitment by the individual clinician to pursue, over time, educational strategies suited to his or her learning style and skill level. System enhancements, such as collaborative relationships with mental health specialists and changes in the financing of mental health care, must precede enhancements in clinical practice. For this reason, the proposed competencies begin with knowledge and skills for systems-based practice. The proposed competencies overlap those of mental health specialists in some areas; for example, they include the knowledge and skills to care for children with attention-deficit/hyperactivity disorder, anxiety, depression, and substance abuse and to recognize psychiatric and social emergencies. In other areas, the competencies reflect the uniqueness of the primary care clinician's role: building resilience in all children; promoting healthy lifestyles; preventing or mitigating mental health and substance abuse problems; identifying risk factors and emerging mental health problems in children and their families; and partnering with families, schools, agencies, and mental health specialists to plan assessment and care. Proposed interpersonal and communication skills reflect the primary care clinician's critical role in overcoming barriers (perceived and/or experienced by children and families) to seeking help for mental health and substance abuse concerns.
Design of the Dubai Metro light rail viaducts—substructure
Authors: Smith D. A. , Hendy C. R.
Published: June 2009

The Dubai Metro light rail scheme is a flagship project in the United Arab Emirates which is currently one of the largest civil engineering projects under construction and, when completed, will be the longest fully automated rail system in the world. The first section of the rail system is due to be opened in September 2009. This paper describes the scheme outline and contractual set-up for the viaduct design and discusses the design and construction of the viaduct substructure. In particular, the design methodologies used for the piled foundations, single reinforced concrete columns and prestressed concrete pier heads are discussed as well as the design of elastomeric bearings that were used extensively for most of the viaduct spans. Seismic loading governed the design of many of the foundations and the seismic analysis and design methodology adopted is discussed, together with specific reinforcement detailing requirements. Rail–structure interaction analysis and design is also covered. Other critical design issues resolved included the fatigue performance of cranked reinforcement and the treatment of the onerous construction loading from overhead gantries used to erect the precast deck segments.
WIND LOADS ON STRUCTURES.
Authors: HORNE M R
Published: June 2009

Synopsis.

From a review of existing knowledge of wind loads it is clear that, although many observations of wind velocities and pressures have been made, it is difficult to estimate their true significance with reference to the derivation of design loads. Velocities vary considerably over the wind front and fluctuate rapidly, and the pressures actually recorded may act on only a small area of a structure and for only a few seconds. Hitherto, practically no attention has been given to the time effect, and an attempt is made in this Paper to estimate the probable damage inflicted on a structure during a high wind. The damage is expressed in terms of the permanent plastic deformation and, hence, wind loads suitable for use in ultimate (plastic) design methods may be derived. Although some numerical results are given, it is found that available data on wind velocities and pressures are insufficient to enable full calculations to be made. The investigation shows clearly the nature of further research which should be under-taken in order to achieve a rational treatment of wind loading.
SOME NOTES ON THE KARUN RIVER AND THE SHATT EL ARAB. (INCLUDES PLATES AND APPENDIX).
Authors: BINNIE G M
Published: June 2009

Synopsis.

The first part of the Paper describes the major rivers of Khuzistan, the ancient irrigation systems, and the possibilities of reviving irrigation on a large scale in the province without deteriment to navigation on the Karun. Used in conjunction with the Ab-i-Diz, a tributary of the Karun, and the River Karkeh, the potentialities of a suggested impounding reservoir on the Upper Karun for irrigation, and for hydro-electricity and flood control in the province are described in general terms. The silt problem is also discussed.

The second part of the Paper describes certain deductions made on the regime of the Shatt el Arab. The rise and fall of the water-level in the inland delta of South Iraq is influenced by the obstruction to the flow of the Shatt el Arab caused by the discharge of the Karun, and the suggested impounding reservoir on the Upper Karun offers possibilities for flood control and land reclamation in South Iraq.
Periodontitis in Pregnancy: Clinical and Serum Antibody Observations From a Baboon Model of Ligature‐Induced Disease
Authors: Cappelli D. , Steffen M.J. , Holt S.C. , Ebersole J.L.
Published: June 2009

Background: Chronic oral infections that elicit host responses leading to periodontal disease are linked with various sequelae of systemic diseases. This report provides seminal information on the clinical and adaptive immunologic characteristics of a baboon model of ligature‐induced periodontitis during pregnancy.

Methods: Female Papio anubis were evaluated for periodontal health at baseline. Ligatures were tied around selected teeth to initiate oral inflammation and periodontitis. Then the animals were bred. At midpregnancy (∼90 days), a clinical evaluation was performed, and additional ligatures were tied on teeth in the contralateral quadrants to maintain progressing periodontitis throughout pregnancy. A final clinical evaluation was done for all experimental teeth after delivery, and ligatures were removed. Serum was collected at all sampling intervals for the determination of antibody levels to a group of 20 oral bacteria. Unligated animals served as controls.

Results: At baseline, 16% of animals exhibited minimal plaque and gingival inflammation without periodontal disease. The remaining baboons demonstrated varying levels of inflammation/bleeding, and ∼20% of the population had periodontal pocketing (>3 mm). Ligated animals expressed increased levels of inflammation and increased probing depths and clinical attachment loss (AL) and could be stratified into multiple subsets postligation based upon changes in clinical parameters at midpregnancy and at delivery. Baboons were categorized into disease susceptibility groups (periodontal disease susceptibility 1 through 4) that described the extent/severity of induced disease during pregnancy. Control animals showed minimal periodontal changes during gestation. Significant differences in serum antibody to multiple oral bacteria were found in animals presenting with periodontitis at baseline and during the 6 months of ligature‐induced disease. A significant correlation to antibody to P. gingivalis, which was sustained throughout ligation and pregnancy, was observed with disease presentation.

Conclusions: The clinical presentation at baseline, reflecting the natural history of oral disease in these animals, suggests individual variation that is reflected in the characteristics of the adaptive immune responses to oral bacteria. The variability in the response to ligation with resulting periodontal disease provides a model to document prospectively the relationship between oral and systemic health outcomes.
Periodontal Disease Status in Gullah African Americans With Type 2 Diabetes Living in South Carolina
Authors: Fernandes Jyotika K. , Wiegand Ryan E. , Salinas Carlos F. , Grossi Sara G. , Sanders John J. , Lopes‐Virella Maria F. , Slate Elizabeth H.
Published: June 2009

Background: African Americans have a disproportionate burden of diabetes. Gullah African Americans are the most genetically homogeneous population of African descent in the United States, with an estimated European admixture of only 3.5%. This study assessed the previously unknown prevalence of periodontal disease among a sample of Gullah African Americans with diabetes and investigated the association between diabetes control and the presence of periodontal disease.

Methods: Two hundred thirty‐five Gullah African Americans with type 2 diabetes were included. Diabetes control was assessed by percentage of glycosylated hemoglobin (HbA1c) and divided into three categories: well controlled, <7%; moderately controlled, 7% to 8.5%; and poorly controlled, >8.5%. Participants were categorized as healthy (no clinical attachment loss [AL] or bleeding on probing) or as having early periodontitis (clinical AL ≥1 mm in at least two teeth), moderate periodontitis (three sites with clinical AL ≥4 mm and at least two sites with probing depth [PD] ≥3 mm), or severe periodontitis (clinical AL ≥6 mm in at least two teeth and PD ≥5 mm in at least one site). Observed prevalences of periodontitis were compared to rates reported for the National Health and Nutrition Examination Survey (NHANES) studies.

Results: All subjects had evidence of periodontal disease: 70.6% had moderate periodontitis and 28.5% had severe disease. Diabetes control was not associated with periodontal disease. The periodontal disease proportions were significantly higher than the reported national prevalence of 10.6% among African Americans without diabetes.

Conclusion: Our sample of Gullah African Americans with type 2 diabetes exhibited a higher prevalence of periodontal disease compared to African Americans, with and without diabetes, as reported in NHANES III and NHANES 1999‐2000.
The Effect of a Pulsed Nd:YAG Laser in Non‐Surgical Periodontal Therapy
Authors: Slot Dagmar E. , Kranendonk Aart A. , Paraskevas Spiros , Van der Weijden Fridus
Published: June 2009

Background: Laser treatment may serve as an alternative or adjunctive treatment to conventional mechanical therapy in periodontics. The neodymium‐doped:yttrium, aluminum, and garnet (Nd:YAG) laser has been used in periodontics. Systematic reviews aid in clinical decision‐making. The aim of this study was to evaluate, in a systematic manner and after a comprehensive search of the literature, the (additional) therapeutic effects of using a pulsed Nd:YAG laser in the initial treatment of patients with periodontitis.

Methods: The focused question for this systematic review was, “What is the efficacy of a pulsed Nd:YAG laser in the initial treatment of patients with periodontitis, either as monotherapy or as an adjunct to non‐surgical periodontal treatment?” The efficacy of this technique was compared to conventional therapy (ultrasonics and/or hand instrumentation) in removing plaque, as well as in improving clinical parameters, such as periodontal inflammation and probing depth. Articles published before May 2008 in the databases of MEDLINE/PubMed and the Cochrane Central Register of Controlled Trials were searched to identify appropriate studies. Clinical parameters of periodontal inflammation, namely, plaque, bleeding, gingivitis, probing depth, clinical attachment level, and gingival recession, were selected as outcome variables.

Results: Independent screening of the titles and abstracts of 285 PubMed and 38 Cochrane articles resulted in eight publications that met the eligibility criteria. Means ± SDs were collected by data extraction; only descriptive analysis was possible.

Conclusions: The majority of the studies analyzed showed no beneficial effect of a pulsed Nd:YAG laser compared to conventional therapy (ultrasonics and/or hand instrumentation) in the initial treatment of patients with periodontitis. The pulsed Nd:YAG laser was assessed as monotherapy and as an adjunct to non‐surgical periodontal treatment; efficacy was determined by the extent of plaque removal and the reduction of periodontal inflammation. This literature review suggests that there is no evidence to support the superiority of the Nd:YAG laser over traditional modalities of periodontal therapy.
Prevalence of Implant Loss and the Influence of Associated Factors
Authors: Koldsland Odd Carsten , Scheie Anne Aamdal , Aass Anne Merete
Published: June 2009

Background: The objective of this study was to assess the outcome of dental implants inserted at the Institute of Clinical Odontology, University of Oslo, between 1990 and 2005. The prevalence of implant loss and the factors associated with the outcome were studied.

Methods: A total of 164 subjects were invited to participate in this cross‐sectional project, of whom 55 were unable, leaving 109 volunteers available for examination. The study population included 69 females and 40 males with a mean age of 43.8 years at the time of implant insertion (range, 18 to 80 years). At the subject level, the mean time from implant loading to the present examination was 8.4 years (range, 1.1 to 16.0 years). The participants were examined clinically and radiographically and interviewed regarding general health and habits.

Results: The 109 examined subjects had been treated with 374 implants. Eighteen implants (4.8%) were lost in 10 subjects (9.2%). Eleven implants were lost before loading, three were lost during the first 5 years after loading, and four were lost 5 to 10 years after loading. No implants were lost after >10 years of loading. The loss of oral implants was significantly associated with a history of smoking and periodontitis (P <0.05).

Conclusions: The inserted implants showed a high survival rate, especially after the first year of insertion, even though the subjects were not maintained by specialists. All late implant losses were preceded by an early loss. Implant loss was significantly associated with smoking and periodontitis.
The Role of the Composite Interleukin‐1 Genotype in the Association Between Periodontitis and Acute Myocardial Infarction
Authors: Stein Jamal M. , Smeets Ralf , Reichert Stefan , Chrobot Jaroslaw , Fickl Stefan , Stanzel Sven , Kuch Bernhard
Published: June 2009

Background: Recent data indicate that interleukin (IL)‐1 polymorphism may influence the susceptibility to periodontitis and coronary heart diseases. The aim of this study was to evaluate the impact of the composite IL‐1 genotype (allele 2 at IL‐1A −889 and IL‐1B +3954) in the association between acute myocardial infarction (AMI) and periodontitis.

Methods: One hundred four white subjects (54 patients with AMI and 50 healthy controls) were studied; each received a comprehensive periodontal examination, including measurement of periodontal probing depth (PD) and clinical attachment level (CAL). The extent of periodontitis was assessed by the percentage of sites with clinical AL >3 mm. Polymorphisms in the IL‐1 gene cluster were assessed using a reverse hybridization assay.

Results: Compared to controls, mean values for PD (4.6 mm versus 3.7 mm; P <0.0001) and CAL (5.4 mm versus 4.5 mm; P = 0.0001) were significantly increased among patients with AMI. Significantly more subjects with moderate or severe periodontitis (≥33% of sites with clinical AL >3 mm) were found in the AMI group compared to controls (31.5% versus 8%; P = 0.0016). These differences remained statistically significant after adjustment for smoking, age, and gender. No significant differences were observed in the allele frequencies of the gene loci IL‐1A −889 and IL‐1B +C3954 between patients with AMI and controls. Also, there was no difference in the frequency of the composite IL‐1 genotype. IL‐1 genotype–positive patients with AMI had slightly increased PD and AL compared to IL‐1 genotype–negative patients with AMI.

Conclusions: The results confirmed an association between periodontitis and AMI but failed to detect a modifying impact of the composite IL‐1 genotype. Although the IL‐1 genotype was only weakly associated with compromised periodontal health, it was not associated with AMI.
A Pilot Study of Glycosylated Hemoglobin Levels in Periodontitis Cases and Healthy Controls
Authors: Wolff Ryan E. , Wolff Larry F. , Michalowicz Bryan S.
Published: June 2009

Background: Periodontitis is associated with glycemic control in patients with diabetes. The purpose of this study was to determine if glycosylated hemoglobin is elevated in patients with periodontitis who have not been diagnosed with diabetes.

Methods: Glycosylated hemoglobin (HbA1c) was assessed using a chairside test in 59 adults without diabetes but with periodontitis (having at least five teeth with probing depth [PD] ≥5 mm, bleeding on probing [BOP], and clinical attachment or radiographic bone loss) and 53 healthy controls (PDs ≤4 mm and BOP ≤15%). Groups were compared using the t test and linear regression. Patients with HbA1c levels ≥6% were compared using the Fisher exact test and logistic regression.

Results: Periodontitis cases were more likely than controls to be male (68% versus 38%; P = 0.002) and current or former smokers (P = 0.002). Cases had significantly higher body mass index (BMI) than controls (27.6 kg/m2 versus 25.5 kg/m2; P = 0.018) but were of similar age (51.3 years versus 50.9 years; P = 0.89). Unadjusted mean HbA1c levels did not differ significantly between cases and controls (5.66% ± 0.56% versus 5.51% ± 0.44%; P = 0.12). After adjustments for age, gender, BMI, and current smoking, mean HbA1c was significantly higher in cases (between‐group difference, 0.21%; P = 0.046). A higher proportion of cases (27.3%) than controls (13.2%) had HbA1c values ≥6%, although this difference was not statistically significant (P >0.1).

Conclusions: Periodontitis is associated with a slight elevation in glycosylated hemoglobin. The clinical significance of this difference remains to be determined. This preliminary finding is consistent with earlier reports that periodontitis is associated with elevated blood glucose in adults without diabetes and may increase one's risk for type 2 diabetes.
Advanced Glycation End Products Inhibit the Expression of Collagens Type I and III by Human Gingival Fibroblasts
Authors: Ren Lei , Fu Yun , Deng Yuquan , Qi Liuying , Jin Lijian
Published: June 2009

Background: It is evident that diabetes and periodontal disease are closely interrelated. Accumulation of advanced glycation end products (AGEs), coupled with exaggerated host responses to bacterial infection, may account for the increased periodontal destruction observed in patients with uncontrolled diabetes. The present study investigated the effects of AGEs on the viability of human gingival fibroblasts (HGFs) and the expression of types I and III collagen in HGFs.

Methods: The cell viability of HGFs was examined by methylthiazolet‐etrazolium assay, whereas the expression of types I and III collagen message and protein was detected by real‐time quantitative reverse transcription‐polymerase chain reaction and sandwich enzyme‐linked immunosorbent assay, respectively.

Results: AGEs significantly suppressed the cell viability of HGFs from 24 to 72 hours (P <0.01). A high concentration of glucose (25 mmol/l) in the culture media exaggerated the inhibition of the survival rate of HGFs (P <0.01). The expression of collagen types I and III messages and proteins was significantly downregulated at 72 hours by AGEs in a concentration‐dependent manner (P <0.05). Moreover, the synthesis of intracellular types I and III collagen protein was markedly inhibited by AGEs (P <0.05).

Conclusions: AGEs may suppress the cell viability of HGFs and downregulate the expression of types I and III collagen by the cells. Further investigations are warranted to clarify the molecular mechanisms of AGEs in the regulation of cell function and collagen metabolism in patients with diabetes and periodontitis.
Elevated Plasma Calcifediol Is Associated With Aggressive Periodontitis
Authors: Liu Kaining , Meng Huanxin , Tang Xiaolin , Xu Li , Zhang Li , Chen Zhibin , Shi Dong , Feng Xianghui , Lu Ruifang
Published: June 2009

Background:Vitamin D is associated with a number of inflammatory diseases and plays a significant role in regulating bone metabolism. Serum calcifediol was demonstrated to be potentially associated with periodontal disease. The purpose of this study was to evaluate whether an association exists between plasma calcifediol concentrations and aggressive periodontitis (AgP) and whether plasma levels of bone‐related biomarkers (osteocalcin, alkaline phosphatase, calcium, and phosphorus) regulated by vitamin D are related to AgP.

Methods:Sixty‐six patients with generalized AgP, 52 patients with chronic periodontitis, and 60 healthy controls were included in this study. Periodontal examination consisted of probing depth, attachment loss, and bleeding index measurements. Hematic calcifediol and bone‐related biomarker levels were detected using radioimmunity assay kits or a biochemical analyzer.

Results:Plasma calcifediol levels in patients with AgP were higher than those of healthy controls (29.28 versus 21.60 nmol/l;P<0.05) and were statistically significantly correlated with bleeding index (r = 0.321;P<0.05). Plasma osteocalcin concentrations in patients with AgP were higher than those of healthy controls (0.90 versus 0.70 ng/ml;P<0.05). Serum inorganic phosphorus values of both periodontitis groups were lower than those of healthy controls (1.06 ± 0.18 mmol/l and 1.10 ± 0.15 mmol/l versus 1.26 ± 0.17 mmol/l;P<0.05).

Conclusion:Plasma calcifediol levels might be associated with periodontal inflammation.
1‐Tetradecanol Complex: Therapeutic Actions in Experimental Periodontitis
Authors: Hasturk Hatice , Goguet‐Surmenian Emilie , Blackwood Amanda , Andry Chris , Kantarci Alpdogan
Published: June 2009

Background: The present study was planned to investigate the therapeutic actions of 1‐tetradecanol complex (1‐TDC), a novel monounsaturated fatty acid mixture, in established periodontitis in rabbits.

Methods: Periodontitis was initiated in 18 New Zealand White rabbits using ligatures around mandibular second premolars, followed by topical Porphyromonas gingivalis application (109 colony forming units). After 6 weeks of disease induction (phase 1), three animals were sacrificed to assess the established periodontitis level. P. gingivalis application was discontinued, and the remaining 15 animals continued with topical treatment of 1‐TDC (100 mg/ml; n = 5) or placebo (n = 5) or no treatment (n = 5) for an additional 6 weeks (phase 2). Mandibular block sections obtained after euthanasia were decalcified and embedded in paraffin. In addition to the macroscopic analyses, hematoxylin and eosin–stained sections were used to study cellular inflammatory infiltrate and quantitative histomorphometry. Tartrate‐resistant acid phosphatase and osteocalcin were used to identify osteoclastic and osteoblastic activity, respectively.

Results: P. gingivalis application resulted in periodontal disease with gingival inflammation and bone loss (30% compared to baseline) at 6 weeks. Treatment with 1‐TDC stopped the progression of the disease and resulted in a significant reduction in the macroscopic periodontal inflammation, attachment, and bone loss (10.1% ± 1.8%), whereas periodontal disease progressed in the untreated and placebo groups (P <0.05). Histologic assessment and histomorphometric measurements demonstrated that 1‐TDC inhibited inflammatory cell infiltration and osteoclastic activity (P <0.05).

Conclusion: The findings suggest that topical application of cetylated monounsaturated fatty acid complex (1‐TDC) is a potential therapeutic approach in controlling the progression of chronic periodontal disease.
Clinical Outcomes of Peri‐Implant Peripheral Giant Cell Granuloma: A Report of Three Cases
Authors: Hernandez Gonzalo , Lopez‐Pintor Rosa M. , Torres Jesús , de Vicente Juan Carlos
Published: June 2009

Background: Peripheral giant cell granuloma (PGCG) is a reactive lesion that occurs on the gingiva or alveolar mucosa and contains numerous giant cells. Its recurrence rate is 10%. Only five cases associated with dental implants have been reported. This case report describes three additional cases with clinical courses and outcomes.

Methods: Three women presented with a chief complaint of a gingival mass around the implants. The lesions were surgically excised under local anesthesia.

Results: The initial diagnosis at presentation was pyogenic granuloma. Radiography showed marginal bone loss accompanying the lesions. Histopathology confirmed the diagnosis of PGCG. In two cases, several recurrences resulted in explantation of the fixture. One case healed uneventfully.

Conclusions: Despite its usually benign clinical behavior, peri‐implant PGCG may follow an aggressive course. Treatment planning for this condition should take into account the presence of recurrences to evaluate the necessity of an aggressive surgical approach that may involve advanced bone loss and explantation. Further research on the origin of this implant‐associated condition with a larger series of cases is necessary to provide a basis for adequate management.
Causes of Post‐Fire Runoff and Erosion: Water Repellency, Cover, or Soil Sealing?
Authors: Larsen Isaac J. , MacDonald Lee H. , Brown Ethan , Rough Daniella , Welsh Matthew J. , Pietraszek Joseph H. , Libohova Zamir , de Dios Benavides-Solorio Juan , Schaffrath Keelin
Published: June 2009

Few studies have attempted to isolate the various factors that may cause the observed increases in peak flows and erosion after high‐severity wildfires. This study evaluated the effects of burning by: (i) comparing soil water repellency, surface cover, and sediment yields from severely burned hillslopes, unburned hillslopes, and hillslopes where the surface cover was removed by raking; and (ii) conducting rainfall simulations to compare runoff, erosion, and surface sealing from two soils with varying ash cover. The fire‐enhanced soil water repellency was only stronger on the burned hillslopes than the unburned hillslopes in the first summer after burning. For the first 5 yr after burning, the mean sediment yield from the burned hillslopes was 32 Mg ha−1, whereas the unburned hillslopes generated almost no sediment. Sediment yields from the raked and burned hillslopes were indistinguishable when they had comparable surface cover, rainfall erosivity, and soil water repellency values. The rainfall simulations on ash‐covered plots generated only 21 to 49% as much runoff and 42 to 67% as much sediment as the plots with no ash cover. Soil thin sections showed that the bare plots rapidly developed a structural soil seal. Successive simulations quickly eroded the ash cover and increased runoff and sediment yields to the levels observed from the bare plots. The results indicate that: (i) post‐fire sediment yields were primarily due to the loss of surface cover rather than fire‐enhanced soil water repellency; (ii) surface cover is important because it inhibits soil sealing; and (iii) ash temporarily prevents soil sealing and reduces post‐fire runoff and sediment yields.
Parameter Estimation of an Adsorption Model for Describing Ion‐Pair Adsorption
Authors: Cichota Rogerio , Vogeler Iris , Bolan Nanthi S. , Clothier Brent E.
Published: June 2009

The simultaneous retention of both cations and anions due to ion‐pair adsorption (IPA) has been identified in several soils. The mechanism controlling IPA is not yet understood, however, and the mathematical description of this phenomenon is only incipient. In this study, a parameterization analysis was performed using a recently proposed adsorption model that considers the occurrence of IPA. The model, which has two alternative approaches to describe IPA, has been shown in a previous study to describe experimental data reasonably well. That analysis was incomplete, however, as the parameter uncertainties were not estimated. In this study, with the parameterization procedure using the maximum‐likelihood method, a robust estimation of the model parameters, including the analysis of their uncertainties, was developed. The model was fitted to a data set obtained in batch experiments using the variable‐charge Egmont soil, from New Zealand, and a comprehensive combination of SO4 and Ca concentrations. This procedure allowed the analysis of some of the underlying model characteristics and also some inferences about the IPA phenomenon. Overall, it was shown that the proposed adsorption model is a useful tool for the modeling of solutes in soils where IPA occurs.
Sediment Transport and Soil Detachment on Steep Slopes: I. Transport Capacity Estimation
Authors: Zhang Guang-hui , Liu Yu-mei , Han Yan-feng , Zhang X. C.
Published: June 2009

Precise estimation of sediment transport capacity (Tc) is critical to the development of physically based erosion models. Few data are available for estimating Tc on steep slopes. The objectives of this study were to evaluate the effects of unit flow discharge (q), slope gradient (S), and mean flow velocity on Tc in shallow flows and to investigate the relationship between Tc and shear stress, stream power, and unit stream power on steep slopes using a 5‐m‐long and 0.4‐m‐wide nonerodible flume bed. Unit flow discharge ranged from 0.625 × 10−3 to 5 × 10−3 m2 s−1 and slope gradient from 8.8 to 46.6%. The diameter of the test riverbed sediment varied from 20 to 2000 μm, with a median diameter of 280 μm. The results showed that Tc increased as a power function with discharge and slope gradient with a coefficient of Nash–Sutcliffe model efficiency (NSE) of 0.95. The influences of S on Tc increased as S increased, with Tc being slightly more sensitive to q than to S The Tc was well predicted by shear stress (NSE = 0.97) and stream power (NSE = 0.98) but less satisfactorily by unit stream power (NSE = 0.92) for the slope range of 8.8 to 46.6%. Mean flow velocity was also a good predictor of Tc (NSE = 0.95). Mean flow velocity increased as q and S increased in this study. Overall, stream power seems to be the preferred predictor for estimating Tc for steep slopes; however, the predictive relationships derived in this study need to be evaluated further in eroding beds using a range of soil materials under various slopes.
Measurements of Nitrate Leaching from a Hillslope Cropland in the Central Sichuan Basin, China
Authors: Zhu Bo , Wang Tao , Kuang Fuhong , Luo Zhuanxi , Tang Jialiang , Xu Taiping
Published: June 2009

Nitrate losses through leaching were studied in a crop field in the central Sichuan Basin, southwestern China, during 2003 to 2006. Nitrate accumulations and losses via leaching were measured using two methods: a simulation with sampled soil profiles and field monitoring in situ at a 7% slope. The results showed that NO3 was accumulated in the dry season and leached in the rainy season. No spatial dependence of soil NO3 distribution could be distinguished along the hillslope due to complex water flow. The soil interflow was the major driver of NO3 leaching losses from the experimental plots. The average annual discharge of the interflows was 148 mm, accounting for 63% of total runoff in the rainy season in 2003 to 2006. The interflow water contained high NO3–N concentrations. The highest NO3–N concentration and loss flux were detected in storm runoff after a long drought in 2006. The NO3–N leaching through interflow showed clear annual and seasonal patterns, and largely occurred in the stages from stamen elongation to maturity of maize (Zea mays L.) with a flux of 2.2 g m−2, about 69% of the total annual loss flux. Annual estimated losses of NO3–N through interflow ranged from 20 to 53, with an average of 36 kg ha−1 yr−1 This study indicates that croplands on hillslopes with regosols are vulnerable to NO3 leaching. The interflow discharge monitoring method together with effluent NO3 content analysis used in this study proved to be useful and effective for quantifying NO3 leaching losses at the field scale in hillslope areas.
Shifts in Microbial Community Composition and Physiological Profiles across a Gradient of Induced Soil Degradation
Authors: Chaer Guilherme M. , Fernandes Marcelo F. , Myrold David D. , Bottomley Peter J.
Published: June 2009

A disturbance gradient was created to evaluate the relationship between changes in soil physical and chemical properties with microbial community composition. Plots of a 12‐yr fallow Ultisol in Northeastern Brazil were arranged in a Latin Square design and disturbed by tillage events applied zero, one, two, three, or four times over a 3‐mo period. Sixty days after the last event, plots were sampled (0–20 cm) and soil analyses performed. Tillage resulted in a linear disturbance gradient characterized by significant declines in soil available water, saturated hydraulic conductivity, soil aggregation, organic C, and microbial biomass. The disturbance gradient also affected soil microbial communities, but the changes observed were dependent on the profiling technique used. The application of one tillage event significantly altered terminal restriction fragment length polymorphism (T‐RFLP) profiles, which remained unchanged on further disturbances. In contrast, community level physiological profiles (CLPPs) continued to change as disturbance levels increased and were significantly correlated with most soil properties associated with soil degradation. Phospholipid fatty acid (PLFA)‐based assessment of microbial community structure was the least sensitive to disturbance, showing significant changes only between the control plots and those subjected to four tillage events. Nevertheless, the linear shift observed in a PLFA biomarker of bacterial stress (ratio of 19:0cy to 18:1w7c) in response to the disturbance gradient was consistent with physiological changes in the CLPPs. The results clearly illustrate that microbial community responses to increasing levels of soil physical disturbance can be detected at physiological (CLPPs), biochemical (PLFA), and genotypic (T‐RFLP) levels; however, they are not synchronously coupled. Further studies are needed to determine if there is functional significance to the physiological responses to disturbance that are, or are not, accompanied by community composition changes.
Sediment Transport and Soil Detachment on Steep Slopes: II. Sediment Feedback Relationship
Authors: Zhang Guang-hui , Liu Yu-mei , Han Yan-feng , Zhang X. C.
Published: June 2009

Quantifying the effect of sediment load on the detachment rate is crucial to understand soil erosion processes and develop physically based soil erosion models. Many recent studies attempted to quantify the feedback relationship between sediment load and detachment rate. To date, however, the effects of sediment load on detachment rate are still unclear. The objectives of this study were to examine the potential effects of sediment load on detachment rates and to examine the widely assumed linear relationship between sediment load and detachment rate in rills under controlled conditions. Experiments were performed in a hydraulic flume with constant roughness. Slope gradient (S) varied from 8.8 to 46.6% and unit flow rate (q) from 1.25 to 5.00 × 10−3 m2 s−1 Detachment rates were measured under different sediment loads, which were 0 (clear water), 25, 50, 75, and 100% of the sediment transport capacity (Tc) for 20 combinations of q and S Results showed that detachment rates decreased as sediment load increased. Discrepancies in declining patterns of detachment rates were observed. Regression results indicated that 16 combinations of q and S were best simulated by linear feedback relationships, while four combinations were best fitted to exponential functions. Both predicted detachment capacity (Dc) and Tc by linear relationships agreed well with the corresponding measured values (R2 = 0.99, Nash–Sutcliffe efficiency [NSE] = 0.97 for Dc; R2 = 0.99, NSE = 0.98 for Tc). The predicted detachment rate by a first‐order coupling equation agreed with the measured data (R2 = 0.94, NSE ≥ 0.92). Overall, the feedback relationship between sediment load and detachment rate in this flume study could be adequately represented by the first‐order coupling equation.
Asset deterioration analysis using multi-utility data and multi-objective data mining
Authors: Savic D. A. , Giustolisi O. , Laucelli D.
Published: June 2009

Physically-based models derive from first principles (e.g. physical laws) and rely on known variables and parameters. Because these have physical meaning, they also explain the underlying relationships of the system and are usually transportable from one system to another as a structural entity. They only require model parameters to be updated. Data-driven or regressive techniques involve data mining for modelling and one of the major drawbacks of this is that the functional form describing relationships between variables and the numerical parameters is not transportable to other physical systems as is the case with their classical physically-based counterparts. Aimed at striking a balance, Evolutionary Polynomial Regression (EPR) offers a way to model multi-utility data of asset deterioration in order to render model structures transportable across physical systems. EPR is a recently developed hybrid regression method providing symbolic expressions for models and works with formulae based on pseudo-polynomial expressions, usually in a multi-objective scenario where the best Pareto optimal models (parsimony versus accuracy) are selected from data in a single case study. This article discusses the improvement of EPR in dealing with multi-utility data (multi-case study) where it has been tried to achieve a general model structure for asset deterioration prediction across different water systems.
Hydroinformatics in multi-colours—part red: urban flood and disaster management
Authors: Mynett Arthur E. , Vojinovic Zoran
Published: June 2009

Hydroinformatics found its origin in the advancement of computational hydraulics in the early 1990s but has expanded considerably, both in scope and in application areas. It is now not only being applied in the fields of hydraulics and hydrology (often indicated by the colour blue), but also in environmental science and technology (green) as well as in knowledge systems and knowledge management (yellow). This paper focuses on urban (red) applications of hydroinformatics, taking urban flood and disaster management as an example. It is part of a sequence of papers, each focusing on a particular field (colour) of hydroinformatics, which together constitute a multi-coloured rainbow of application areas that hydroinformatics has expanded into over the past two decades or so. The combined papers on “Hydroinformatics in multi-colours” were presented as the opening keynote of the Workshop on Advances in Hydroinformatics held in Niagara Falls, in June 2007. In this paper—part red of the sequence—the role of urban hydroinformatics in assessing effects of climate change on urban flooding and health risk is addressed in relation to the UN Millennium Development Goals and illustrated on a case study of Dhaka, Bangladesh.
Investigating the capabilities of evolutionary data-driven techniques using the challenging estimation of soil moisture content
Authors: Elshorbagy Amin , El-Baroudy Ibrahim
Published: June 2009

Soil moisture has a crucial role in both the global energy and hydrological cycles; it affects different ecosystem processes. Spatial and temporal variability of soil moisture add to its complex behaviour, which undermines the reliability of most current measurement methods. In this paper, two promising evolutionary data-driven techniques, namely (i) Evolutionary Polynomial Regression and (ii) Genetic Programming, are challenged with modelling the soil moisture response to the near surface atmospheric conditions. The utility of the proposed models is demonstrated through the prediction of the soil moisture response of three experimental soil covers, used for the restoration of watersheds that were disturbed by the mining industry. The results showed that the storage effect of the soil moisture response is the major challenging factor; it can be quantified using cumulative inputs better than time-lag inputs, which can be attributed to the effect of the soil layer moisture-holding capacity. This effect increases with the increase in the soil layer thickness. Three different modelling tools are tested to investigate the tool effect in data-driven modelling. Despite the promising results with regard to the prediction accuracy, the study demonstrates the need for adopting multiple data-driven modelling techniques and tools (modelling environments) to obtain reliable predictions.
Tools for the assessment of hydrological ensemble forecasts obtained by neural networks
Authors: Boucher Marie-Amélie , Perreault Luc , Anctil François
Published: June 2009

The increasing demand for uncertainty assessment in streamflow forecasts has drawn the hydrological community's interest toward ensemble forecasting techniques. The widespread deterministic hydrological forecasting point of view focuses to a great extent on the search for a hydrological model that would come as close as possible to “perfection” (i.e. the aim is to implement a model that produces a point forecast that is as close as possible as the observed outcome). On the other hand, ensemble forecasting departs from the deterministic point of view by avoiding the assumption that the “perfect” model exists and instead focuses on issuing a type of forecast that accounts explicitly for the uncertainty inherent to the forecasting process as a whole. In this paper, one-day-ahead hydrological ensemble forecasts obtained by stacked neural networks are presented and analysed. To do so, three simple performance assessment criteria are presented. Those criteria were originally developed in the meteorological and statistical communities to accommodate the need for a quality assessment methodology that is coherent with the probabilistic nature of ensemble weather forecasts. It will be shown that, even though the ensemble forecasts suffer from underdispersion, they outperform point forecasts.
Advances in the identification and evaluation of complex environmental systems models
Authors: Wagener Thorsten , Reed Patrick , van Werkhoven Kathryn , Tang Yong , Zhang Zhenxing
Published: June 2009

Advances in our ability to model complex environmental systems are currently driven by at least four needs: (1) the need for the inclusion of uncertainty in monitoring, modelling and decision-making; (2) the need to provide environmental predictions everywhere; (3) the need to predict the impacts of environmental change; and (4) the need to adaptively evolve observation networks to better resolve environmental systems and embrace sensing innovations. Satisfying these needs will require improved theory, improved models and improved frameworks for making and evaluating predictions. All of these improvements should result in the long-term evolution and improvement of observation systems. In the context of this paper we discuss current bottlenecks and opportunities for advancing environmental modelling with and without local observations of system response. More realistic representations of real-world thresholds, nonlinearities and feedbacks motivates the use of more complex models as well as the consequent need for more rigorous evaluations of model performance. In the case of gauged systems, we find that global sensitivity analysis provides a widely underused tool for evaluating models' assumptions and estimating the information content of data. In the case of ungauged systems, including the modelling of environmental change impacts, we propose that the definition of constraints on the expected system response provides a promising way forward. Examples of our own work are included to support the conclusions of this discussion paper. Overall, we conclude that an important bottleneck currently limiting environmental predictions lies in how our model evaluation and identification approaches are extracting, using and evolving the information available for environmental systems at the watershed scale.
Applications of numerical modelling in hydroinformatics
Authors: Abbott M. B. , Vojinovic Z.
Published: June 2009

After a brief review of the mutation from modern to postmodern conditions of society, that is, from societies of knowers to societies of consumers of knowledge, the position of the knowledge provider in hydroinformatics is introduced. The provider's changing role in a society with an ever-increasing emphasis on communication is introduced. The sociotechnical forces that have driven numerical modelling, first from second to third generation, then to the fourth generation, and now into a fifth generation, are explicated. These forces are exemplified by an increasingly active stakeholder participation in projects, joint policy formulation and on-line management. The applications to the increasingly problematic developments in the so-called ‘Third World’ are then considered.

The overall consequences for the future of numerical modelling practice are then explored. The role of open-source software developments interacting with proprietorial software, together with the development and introduction of service-oriented architectures are explained. The concept of the knowledge supply chain is then advanced to introduce the concept of the extended halo of the global knowledge provider. This paper concludes with an analysis of appropriate and less appropriate business models.
Data and hydroinformatics: new possibilities and challenges
Authors: Gourbesville Philippe
Published: June 2009

The technology evolution, with new types of sensors such as acoustic Doppler current profiler (ADCP), multibeam sonars, light detection and ranging (LIDAR) and pushbroom cameras, has deeply modified the quality and the quantity of data available on hydro-environments. The hydroinformatics systems now have the possibility to investigate the details of the physical hydrodynamic process as well as the complexity of the geometry of the continental and marine environments. This new situation represents a unique situation where all hydroinformatics approaches (data driven and physically based) can be associated and combined. We provide a general overview of the different new emerging technologies and explore the added value provided by the new datasets. The presentation covers the data acquisition processes for velocity of currents and river flows. Doppler technology is presented and illustrated through an example located in Monaco. The numerous datasets demonstrate clearly the ability of the technology to highlight the complexity of the physical processes and to revisit the assumptions made in the different modelling systems. The availability of data allows the combination of data driven models in order to generate boundary conditions for physically based tools. The second part of the paper discusses high-resolution digital elevation models (DEMs) for bathymetry and topography representation. Geometry representation is a key issue in distributed models. Advances in the form of multibeam sonar and pushbroom cameras allow an improved modelling process. The hydroinformatics tools are facing a new challenge, in that the conceptual approaches used in the different models have to be redefined for a data rich environment.