bluuebunny/crossref_metadata_2025 huggingface dataset:
Daily Versus As-Needed Corticosteroids for Mild Persistent Asthma
Authors: Chipps Bradley E.
Published: September 2006

Purpose of the Study.

To determine the effectiveness of as-needed versus regular controller therapy in adults with mild persistent asthma.

Study Population.

A total of 225 adults with symptom criteria for mild persistent asthma and forced expiratory volume in 1 second (FEV1) >70% predicted with >12% reversibility or PC20 (provocative concentration causing a 20% decrease in FEV1) methacholine at ≤16 mg/mL.

Methods.

Patients were assigned to 1 of 3 treatment groups: budesonide DPI 200 μg twice daily (BUD), oral zafirlukast 20 mg twice daily (ZAF), or placebo. The study was double-blind, double-dummy. At the beginning and the end of the study, all patients were treated with 0.5 mg/kg per day of prednisone, 800 μg twice a day of budesonide, and 20 mg twice a day of zafirlukast plus as-needed albuterol. Evaluation was accomplished by assessing asthma symptoms followed by pulmonary-function testing and gathering information on, albuterol use and exacerbations over the 1-year study.

Results.

For both of the primary efficacy outcomes, morning peak expiratory flow rate and exacerbations, there were no differences between the groups. Several outcomes were superior for the BUD group, including prebronchodilator FEV1, bronchial reactivity, symptom scores, exhaled nitric oxide, asthma control score, and symptom-free days (26 more). Postbronchodilator FEV1 and quality of life were not different between the groups. The as-needed group took budesonide, on average, for only one-half week during the study.

Conclusions.

Adults with mild persistent asthma can be managed with high-dose budesonide on an intermittent basis. However, greater improvement in markers of airway inflammation and more symptom-free days (26 per year) occurred with regular use of low-dose budesonide.

Reviewer Comments.

This is an adult study that focused on short-term outcomes, which may not translate to children. It is not known if similar results would be seen with a longer-term study.
Long-term Safety of Once-Daily Budesonide in Patients With Early-Onset Mild Persistent Asthma: Results of the Inhaled Steroid Treatment as Regular Therapy in Early Asthma (START) Study
Authors: Skolnick Helen
Published: September 2006

Purpose of the Study.

Inhaled corticosteroids are the recommended treatment for all patients with persistent asthma. The aim of this study was to evaluate the safety and tolerability of long-term treatment of patients with mild persistent asthma with once-daily budesonide.

Study Population.

Seven thousand two hundred twenty-two patients (aged 5–66 years) with mild persistent asthma diagnosed within 2 years of study entry, with wheeze, cough, dyspnea, or chest tightness weekly and demonstration of reversible airway obstruction, were enrolled into the study.

Methods.

This was a prospective, double-blind, placebo-controlled study. Patients were divided into 2 groups according to age. Those patients younger than 11 years received 200 μg of budesonide via a dry-powder inhaler or placebo, and patients 11 years and older received 400 μg of budesonide via dry-powder inhaler or placebo. All treatments were administered for 3 years and in addition to the patients’ usual asthma therapy.

Results.

Overall, 21 520 adverse events were reported (10 850 in the budesonide group and 10 670 in the placebo group). The most commonly reported events were respiratory infections such as rhinitis, pharyngitis, bronchitis, viral infections, and sinusitis. Oral candidiasis was more common in the budesonide group (1.2%) than in the placebo group (0.5%); the frequencies of other adverse effects previously reported to be associated with inhaled corticosteroids (skin disorders, psychiatric disorders, and allergic reactions) were similar between the 2 groups. The number of deaths and serious adverse events were similar for children and adults in both treatment groups.

Conclusions.

Three-year treatment with budesonide (200 or 400 μg) is safe and well tolerated in both children and adults who have recent onset of mild persistent asthma.

Reviewer Comments.

This study shows not only that budesonide dramatically reduces the overall risk of experiencing a severe asthma-related event but also that budesonide has very little risk of causing any significant adverse events. One of the most difficult, yet very important tasks as a physician is to educate the patient that inhaled corticosteroids are not the enemy, but rather that the patient’s health is at greater risk from asthma itself. Clearly, early intervention is safe and effective. This study provides valuable information and should help patients and their families to feel comfortable with long-term inhaled corticosteroids use in asthma.
The Natural History of Tree Nut Allergy
Authors: Nowak-Wegrzyn Anna
Published: September 2006

Purpose of the Study.

To estimate the proportion of children who outgrow tree nut (TN) allergy and examine predictors of outgrowing it.

Study Population.

All children with TN allergy followed at the authors’ pediatric allergy clinic.

Methods.

Patients with TN allergy, defined as a history of reaction on ingestion and evidence of TN-specific immunoglobulin E (TN-IgE) or positive TN-specific IgE level but no history of ingestion, were evaluated. If all current TN-IgE levels were <10 kU of antibody (kUA)/L, double-blind, placebo-controlled food challenges were offered. Patients who had undergone open oral TN challenges as part of routine clinical care were also included.

Results.

Two hundred seventy-eight patients with TN allergy were identified. One hundred one (36%) had a history of acute reactions, 12 (12%) of whom had reactions to multiple TNs and 73 (63%) of whom had a history of moderate-to-severe reactions. Nine of 20 patients who had previously reacted to a TN passed challenges, so that 9 (8.9%; 95% confidence interval: 4%–16%) of 101 patients with a history of previous TN reactions outgrew TN allergy. Of 19 patients who had never ingested TNs but had detectable TN-specific IgE levels, 14 passed challenges. One hundred sixty-one did not meet the challenge criteria, and 78 met the criteria but declined challenges. Looking at specific TN-IgE values, 58% with TN-IgE levels of ≤5 kUA/L and 63% with TN-IgE levels of ≤2 kUA/L passed challenges.

Conclusions.

Approximately 9% of patients outgrow TN allergy, including some who had previous severe reactions. Although ideal cutoffs for challenge cannot be firmly recommended on the basis of these data, patients aged 4 years or older with all TN-IgE levels of ≤5 kUA/L should be considered for physician-supervised oral food challenges.

Reviewer Comments.

This is the first study to comprehensively address the natural history of TN allergy. Although the 9% chance of outgrowing TN allergy may seem low, it may be an underestimate of the actual resolution rate, because a large number of eligible patients declined diagnostic food challenges. The results of this study should encourage regular follow-up of children with TN allergy and consideration, when clinically indicated, for physician-supervised oral food challenges to determine the possibility of resolution. Because these oral food challenges can trigger anaphylaxis, they are generally undertaken under the supervision of an allergist and with immediate access to medications and equipment to treat a significant allergic reaction.
A Meta-analysis on Intravenous Magnesium Sulphate for Treating Acute Asthma
Authors: Kelso John M.
Published: September 2006

Purpose of the Study.

To evaluate the effectiveness of intravenous magnesium sulfate in the treatment of acute asthmatic attacks in children.

Study Population.

Pediatric patients (n = 182) with moderate-to-severe asthmatic attacks in the emergency department in 5 randomized, placebo-controlled trials comparing intravenous magnesium sulfate to placebo, with co-therapies of inhaled β2 agonists and systemic steroids.

Methods.

Meta-analysis that evaluated outcomes of hospitalization, short-term pulmonary-function tests, and symptom scores.

Results.

Magnesium sulfate was effective in preventing hospitalization (odds ratio: 0.29; 95% confidence interval: 0.143–0.589). The number needed to treat was 4 (95% confidence interval: 3–8). Secondary outcomes of short-term pulmonary-function tests and clinical symptom scores also showed significant improvement. The therapy was well tolerated with only minor adverse effects reported.

Conclusion.

Intravenous magnesium sulfate probably provides additional benefit in moderate-to-severe acute asthma in children treated with bronchodilators and steroids.

Reviewer Comments.

Meta-analyses are useful when multiple previous studies have shown inconsistent results. They may not, however, be the final answer, because subsequent large trials can alter the conclusion of a meta-analysis. Nonetheless, the data to date considered in this meta-analysis seem quite convincing. Also, the treatment is inexpensive and well tolerated, and the number needed to treat is small (you would need to give this therapy to only 4 children to keep 1 out of the hospital).
Presenting Phenotype in 100 Children With the 22q11 Deletion Syndrome
Authors: Bonilla Francisco A.
Published: September 2006

Purpose of the Study.

To describe the clinical presentations of individuals having deletion of the 22q11 region.

Study Population.

The first 100 individuals <20 years old presenting to the Queen Sylvia Children’s Hospital (Göteborg, Sweden) and found to have 22q11 deletion (from 1993–2002).

Methods.

All diagnoses were confirmed by fluorescence in situ hybridization. Clinical data collected at diagnosis included age and clinical findings in 8 categories (1, cardiac defects; 2, thymus size, infection history, autoimmune disease; 3, hypocalcemia; 4, feeding difficulties; 5, cleft lip/palate, speech/language impairment; 6, developmental delay, learning difficulties, behavioral abnormalities; 7, other malformations/deformities; 8, dysmorphic features). Those features that led (in particular) to the consideration of the diagnosis were distinguished.

Results.

The largest number was diagnosed by cardiologists (39) at a median age of 0.5 years old, with cleft palate or speech pathology specialists second (22) at a median age of 8 years, and neurologists or psychiatrists third (19) at a median age of 11.2. Note that 68 of the 74 children diagnosed after age 2 were born before the fluorescence in situ hybridization test was routinely available. The main findings are summarized in Table 1.

Conclusions.

The authors offer diagnostic guidelines for testing for 22q11 deletion (for infants: any typical cardiac defect or 2 of the features in categories 2 through 5, 7, or 8; for preschool-aged children and adolescents: any 2 of the 8 categories either present currently or in the past medical history).

Reviewer Comments.

22q11 deletion leads to a spectrum of phenotypes most commonly called velocardiofacial syndrome and/or DiGeorge syndrome. Occurring in ∼1 in 3000 to 4000 live births, it is among the most common syndromes associated with primary immunodeficiency. Serious infection occurs but is relatively rare. Early diagnosis is most desirable to prevent or mitigate morbidity arising from developmental and psychiatric complications in childhood and adolescence. Of the major clinical manifestations, the symptoms arising from velopharyngeal insufficiency (poor suck, nasal reflux) and various associated malformations seem to be significantly overlooked. The fact that all patients had subtle characteristic dysmorphisms that did not contribute very much to diagnosis shows how much our vision improves with the aid of molecular genetic glasses.
Sex-steroid regulation of vascular endothelial growth factor in breast cancer
Authors: Hyder S M
Published: September 2006

Angiogenesis is a key event, which occurs in both normal and pathological expansion of tissues and provides the nourishment necessary for growth. The role of angiogenic growth factors in breast pathology is rapidly gaining recognition since scientists and clinicians realized that these factors could function as molecular targets event 550 209822 for controlling tumor expansion. Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. Although significant advances have been made in understanding the sex-steroid-dependent regulation of this key factor, the role of VEGF in controlling breast tumors is not well understood. In this review, I discuss recent studies describing the role of the female sex steroids estrogens and progestins in the regulation of VEGF in breast cancer cells. Furthermore, I present a summary of recent studies from other biological systems (mainly focused on tumor biology) directed towards providing us with a better understanding of the regulation of classical VEGF and VEGF receptors. I propose that by extending such studies we will gain deeper insights into how we might combat the progression of breast cancer by controlling hormone-dependent angiogenesis within tumor tissue. I believe that information gained from such studies will permit us to target angiogenic growth factors and their initiated signal transduction pathways in a more precise and selective manner, and thereby to control the formation of new blood vessels that fuel the rapid growth of breast tumors. Finally, it is my hope that the concepts discussed here will help elucidate molecular targets in the hormone-dependent angiogenesis pathway that will ultimately allow us to overcome anti-hormone resistance and to provide insights into how we might pursue the concept of chemoprevention by considering ‘angioprevention’ as the end point.
Stat5 expression predicts response to endocrine therapy and improves survival in estrogen receptor-positive breast cancer
Authors: Yamashita H , Nishio M , Ando Y , Zhang Z , Hamaguchi M , Mita K , Kobayashi S , Fujii Y , Iwase H
Published: September 2006

Constitutively activated signal transducers and activators of transcription (Stats), in particular Stat3 and Stat5, have been demonstrated to directly contribute to oncogenesis by stimulating cell proliferation and preventing apoptosis in various cancers. Stat3 is essential in mammary gland epithelial cell apoptosis and involution, whereas Stat5 is well established as a key factor in mammary epithelial cell growth and differentiation. Crosstalk between Stats and estrogen receptor (ER) has been demonstrated by several laboratories and we have focused on the role of Stat5 in ER-positive breast cancer. Using immunohistochemical techniques, we examined the expression of Stat3 and Stat5 in 517 human breast cancer tissues and analyzed their significance for prognosis and prediction of response to endocrine therapy. Stat5 expression was significantly correlated with histological grade (P < 0.0001), ER (P = 0.02), and progesterone receptor (P = 0.026) expression. There was no difference between Stat3 expression and clinicopathological factors. In 346 patients with ER-positive breast cancer, patients with Stat5 positive tumors had significantly increased overall survival (P = 0.0009) in multivariate analysis. There were 70 patients who received endocrine therapy as first-line treatment for metastatic breast cancer at relapse. The patients whose primary breast tumors were Stat5 positive, had significantly better response to endocrine therapy (P = 0.04), and longer survival after relapse (P = 0.0003), than those whose tumors were Stat5 negative. The present study demonstrates for the first time that Stat5 is a predictive factor for endocrine therapy response and a strong prognostic molecular marker in ER-positive breast cancer. Our data suggest that the expression of Stat5 is helpful in selecting patients who may benefit from endocrine therapy.
Phosphorylation of ERα at serine 118 in primary breast cancer and in tamoxifen-resistant tumours is indicative of a complex role for ERα phosphorylation in breast cancer progression
Authors: Sarwar N , Kim J-S , Jiang J , Peston D , Sinnett H D , Madden P , Gee J M , Nicholson R I , Lykkesfeldt A E , Shousha S , Coombes R C , Ali S
Published: September 2006

Oestrogen receptor-α (ERα) is an important prognostic marker in breast cancer and endocrine therapies are designed to inhibit or prevent ERα activity. In vitro studies have indicated that phosphorylation of ERα, in particular on serine 118 (S118), can result in activation in a ligand-independent manner, thereby potentially contributing to resistance to endocrine agents, such as tamoxifen and aromatase inhibitors. Here we report the immunohistochemistry (IHC) of S118 phosphorylation in 301 primary breast tumour biopsies. Surprisingly, this analysis shows that S118 phosphorylation is higher in more differentiated tumours, suggesting that phosphorylation at this site is associated with a good prognosis in patients not previously treated with endocrine agents. However, we also report that S118 phosphorylation was elevated in tumour biopsies taken from patients who had relapsed following tamoxifen treatment, when compared to pre-treatment biopsies. Taken together, these data are consistent with the view that S118 phosphorylation is a feature of normal ERα function and that increases in levels of phosphorylation at this site may play a key role in the emergence of endocrine resistance in breast cancer.
Enhancement of sodium/iodide symporter expression in thyroid and breast cancer
Authors: Kogai T , Taki K , Brent G A
Published: September 2006

The sodium/iodide symporter (NIS) mediates iodide uptake in the thyroid gland and lactating breast. NIS mRNA and protein expression are detected in most thyroid cancer specimens, although functional iodide uptake is usually reduced resulting in the characteristic finding of a ‘cold’ or non-functioning lesion on a radioiodine image. Iodide uptake after thyroid stimulating hormone (TSH) stimulation, however, is sufficient in most differentiated thyroid cancer to utilize β-emitting radioactive iodide for the treatment of residual and metastatic disease. Elevated serum TSH, achieved by thyroid hormone withdrawal in athyreotic patients or after recombinant human thyrotropin administration, directly stimulates NIS gene expression and/or NIS trafficking to the plasma membrane, increasing radioiodide uptake. Approximately 10–20% differentiated thyroid cancers, however, do not express the NIS gene despite TSH stimulation. These tumors are generally associated with a poor prognosis. Reduced NIS gene expression in thyroid cancer is likely due in part, to impaired trans-activation at the proximal promoter and/or the upstream enhancer. Basal NIS gene expression is detected in about 80% breast cancer specimens, but the fraction with functional iodide transport is relatively low. Lactogenic hormones and various nuclear hormone receptor ligands increase iodide uptake in breast cancer cells in vitro, but TSH has no effect. A wide range of ‘differentiation’ agents have been utilized to stimulate NIS expression in thyroid and breast cancer using in vitro and in vivo models, and a few have been used in clinical studies. Retinoic acid has been used to stimulate NIS expression in both thyroid and breast cancer. There are similarities and differences in NIS gene regulation and expression in thyroid and breast cancer. The various agents used to enhance NIS expression in thyroid and breast cancer will be reviewed with a focus on the mechanism of action. Agents that promote tumor differentiation, or directly stimulate NIS gene expression, may result in iodine concentration in ‘scan-negative’ thyroid cancer and some breast cancer.
Proliferative responses to altered 17β-hydroxysteroid dehydrogenase (17HSD) type 2 expression in human breast cancer cells are dependent on endogenous expression of 17HSD type 1 and the oestradiol receptors
Authors: Jansson A , Gunnarsson C , Stål O
Published: September 2006

The primary source of oestrogen in premenopausal women is the ovary but, after menopause, oestrogen biosynthesis in peripheral tissue is the exclusive site of formation. An enzyme group that affects the availability of active oestrogens is the 17β-hydroxysteroid dehydrogenase (17HSD) family. In breast cancer, 17HSD type 1 and type 2 have been mostly investigated and seem to be the principal 17HSD enzymes involved thus far. The question whether 17HSD type 1 or type 2 is of greatest importance in breast tumour development is still not clear. The aim of this study was to investigate how the loss of 17HSD type 2 expression, using siRNA in the non-tumour breast epithelial cells HMEC (human mammal epithelial cells) and MCF10A, and gain of 17HSD type 2 expression, using transient transfection in the breast cancer derived cell lines MCF7 and T47D, affect oestradiol conversion and proliferation rate measured as S-phase fraction. We further investigated how this was related to the endogenous expression of 17HSD type 1 and oestradiol receptors in the examined cell lines. The oestradiol level in the medium changed significantly in the MCF7 transfected cells and the siRNA-treated HMEC cells, but not in T47D or MCF10A. The S-phase fraction decreased in the 17HSD type 2-transfected MCF7 cells and the siRNA-treated HMEC cells. The results seemed to be dependent on the endogenous expression of 17HSD type 1 and the oestradiol receptors. In conclusion, we found that high or low levels of 17HSD type 2 affected the oestradiol concentration significantly. However, the response was dependent on the endogenous expression of 17HSD type 1. Expression of 17HSD type 1 seems to be dominant to 17HSD type 2. Therefore, it may be important to investigate a ratio between 17HSD type 1 and 17HSD type 2.
Octreotide promotes apoptosis in human somatotroph tumor cells by activating somatostatin receptor type 2
Authors: Ferrante E , Pellegrini C , Bondioni S , Peverelli E , Locatelli M , Gelmini P , Luciani P , Peri A , Mantovani G , Bosari S , Beck-Peccoz P , Spada A , Lania A
Published: September 2006

Somatostatin analogs currently used in the treatment of acromegaly and other neuroendocrine tumors inhibit hormone secretion and cell proliferation by binding to somatostatin receptor type (SST) 2 and 5. The antiproliferative pathways coupled to these receptors have been only partially characterized. The aim of this study was to evaluate the effect of octreotide and super selective SST2 (BIM23120) and SST5 (BIM23206) analogs on apoptotic activity and apoptotic gene expression in human somatotroph tumor cells. Eight somatotroph tumors expressing similar levels of SST2 and SST5 evaluated by real-time PCR and western blot analyses were included in the study. In cultured cells obtained from these tumors, octreotide induced a dose-dependent increase of caspase-3 activity (160 ± 20% vs basal at 10 nM) and cleaved cytokeratin 18 levels (172 ± 25% vs basal) at concentrations higher than 0.1 nM. This effect was due to SST2 activation since BIM23120 elicited comparable responses, while BIM23206 was ineffective. BIM23120-stimulated apoptosis was dependent on phosphatases, since it was abrogated by the inhibitor orthovanadate, and independent from the induction of apoptosis-related genes, such as p53, p63, p73, Bcl-2, Bax, BID, BIK, TNFSF8, and FADD. In somatotroph tumors, both BIM23120 and BIM2306 caused growth arrest as indicated by the increase in p27 and decrease in cyclin D1 expression. In conclusion, the present study showed that octreotide-induced apoptosis in human somatotroph tumor cells by activating SST2. This effect, together with the cytostatic action exerted by both SST2 and SST5 analogs, might account for the tumor shrinkage observed in acromegalic patients treated with long-acting somatostatin analogs.
Effect of concrete composition on durability in natural acidic environment
Authors: Wasserman R. , Bentur A.
Published: September 2006

The durability of concretes from the precast industry was studied in environmental conditions simulating wetting/ drying in a natural acidic environment. The industrial concretes were dry concrete and fluid concrete, both having cement content of 265 kg/m3. They were compared with conventional concrete of 360 kg/m3 cement content, with all the concretes studied having the same water/cement ratio of 0·47. Ageing in the mild acidic environment did not result in any detrimental effect and in some cases even a positive influence was observed. These differences were discussed in terms of the micro-structural observations. The strength was largely independent of the type of concrete, reflecting their similar water/cement ratio. However, permeability and performance with regard to carbonation and chloride penetration was significantly better in the industrial concretes, and this was attributed to their lower cement content. This trend suggests that the current standards that set the requirements for minimum cement content for durability should be revisited.
Diffusion of water and methanol vapour in hydrated Portland cement paste
Authors: Beaudoin J. J. , Tumidajski P. J.
Published: September 2006

Equations are developed to describe the combined effect of diffusion and adsorption of water and methanol vapour in hydrated cement paste. The dynamic equation of flow is obtained by equating the space derivative of the spreading pressure of the adsorbed film to a resistive force equal to the product of the coefficient of resistance and the velocity of the film. Qualitative agreement is found for the diffusion of water and methanol vapour through cement paste when the BET and Langmuir equations respectively are used for adsorption. The diffusion of methanol vapour is underestimated due to intercalation and chemical interaction effects. The validity of Fick's law is discussed.
Research on the absorbing characteristics of cement matrix composites filled with carbon black-coated expanded polystyrene beads
Authors: Du J. , Liu S. , Guan H.
Published: September 2006

A new cement matrix composite filled with carbon black-coated expanded polystyrene (EPS) beads was developed. The electromagnetic reflection loss of this composite in the frequency range from 2·6 to 8 GHz was studied experimentally. It was shown that filling with carbon black (CB)-coated EPS beads can improve the reflection loss of plain cement-based materials greatly, and the EPS filler ratio and sample thickness all have remarkable effects on the electromagnetic wave reflection loss of this cement matrix composite material. With a CB-coated EPS filler volume concentration of 80% and sample thickness of 20 mm, the reflection loss can reach −24 dB in the range 2·6-8 GHz and the bandwidth for −10 dB reaches 3 GHz. This composite material still has a relatively low bulk density and can be handled easily.
Comparative studies of three methods for activating rejected fly ash
Authors: Qiao X. C. , Poon C. S. , Cheung E.
Published: September 2006

Pulverised fuel ash is a by-product of burning coal during the generation of electricity. In many places, the collected pulverised fuel ash has to be processed through a classifying stage before it can be used as a construction material. The rejected portion of the classifying process has remained unused due to its high carbon content and large particle size (> 45 μm). However, the rejected ash may be used in certain areas, such as in solidification and stabilisation processes of hazardous waste, and materials for road base or sub-base construction, which require relatively lower strength and reactivity. This paper presents the results of a study on the pozzolanic properties of cementitious materials prepared by blending rejected fly ash (rFA) with calcium hydroxide. The effects of adding chemical activators, elevating curing temperature, and grinding of the ash particles on the activation of rFA were compared by means of compressive strength, differential scanning calorimetry-thermogravimetric analysis, X-ray diffraction analysis and mercury intrusion porosimetry tests. The results show that the addition of Na2SO4 can significantly accelerate the strength development both at 28 and 90 days. K2SO4 is only effective at 28 days. The addition of flue gas desulphurisation sludge (a low-grade gypsum) and grinding can only increase the strength at 90 days. Pretreatment by steam curing decreases the 90 day strength of the samples. The compressive strength results correlate nicely with the results of the porosity and the thermal analysis tests. Adding chemical activators seems to be an effective and economical method to accelerate the hydration of rFA.
The Asian Development Bank and the case study of the Theun-Hinboun hydropower project in Lao PDR
Authors: Jusi S.
Published: September 2006

The Asian Development Bank (ADB) is one of the most influential development institutions in the Greater Mekong sub-region in the push to build large-scale infrastructure including hydroelectric dams. Controversies over big dams in Asia have unveiled the lack of effective governance mechanisms through which all stakeholder interests can be taken into account in resource management decision making. In the case of the Theun-Hinboun hydropower project in Lao PDR, the actions of the ADB have showed inadequacies regarding the project decision making and implementation processes although the project has been economically successful and the ADB has enhanced the country's capacity build-up. The aim of the article is to review the history of the Theun-Hinboun project and identify areas that need to be strengthened recognizing future planning needs, and to identify important future lines of study at Theun-Hinboun. Good governance can be enhanced by institutionalizing participation at the project, district, provincial and national levels including improving inter-agency coordination. An institutional mechanism, which ensures that revenue from the export of hydropower is actually used for poverty alleviation, is needed.
Public participation in water management in northern Thai highlands
Authors: Heyd Helene , Neef Andreas
Published: September 2006

In the early 1990s, Thailand launched an ambitious program of decentralized governance, conferring greater responsibilities upon sub-district administrations and providing fiscal opportunities for local development planning. This process was reinforced by Thailand's new Constitution of 1997, which explicitly assures individuals, communities and local authorities the right to participate in the management of natural resources.

Drawing on a study of water management in the Mae Sa watershed, northern Thailand, this article analyzes to what extent the constitutional right of participation has been put into practice. To this end, a stakeholder analysis was conducted in the watershed, with a focus on local people's interests and strategies in water management and the transformation of participatory policies through government agencies at the local level. While government officers stressed the importance of stakeholder inclusion and cooperation with the local people, there is a sharp contrast between the official rhetoric and the reality on the ground. The analysis reveals that government officers, particularly in the conservation-oriented agencies, are not disposed to devolve power to lower levels and that participation of local people in water management seems currently to be passive or, at best, consultative in nature.

In order to deal with the increasingly severe water problems in northern Thailand, decision makers have to recognize the value of participation and promote a profound change in government officers' attitudes towards local people through training programs and incentives.
Building a mosaic of values to support local water resources management
Authors: Hermans Leon M. , van Halsema Gerardo E. , Mahoo Henry F.
Published: September 2006

Water valuation is needed to enable sound and well-informed decisions on the allocation and management of water resources. The existing methods for water valuation have an important potential and need to be further developed. Practical tools are especially urgently needed to aid implementation on the ground. There is a need to expand the scope of existing water valuation methods beyond the focus on economic values to also include social and environmental values. Also, water valuation needs to fit the constraints of data availability and expertise that are typically found in practice and should be stakeholder driven, addressing values that are of relevance to local stakeholders. This paper proposes a stakeholder-driven approach to water valuation, based on the use of different indicators to produce a mosaic of values that support water resources management by local stakeholders. The use of this approach is illustrated by a case study in Tanzania.
Hydro-hegemony – a framework for analysis of trans-boundary water conflicts
Authors: Zeitoun Mark , Warner Jeroen
Published: September 2006

The increasing structural and physical scarcity of water across the globe calls for a deeper understanding of trans-boundary water conflicts. Conventional analysis tends to downplay the role that power asymmetry plays in creating and maintaining situations of water conflict that fall short of the violent form of war and to treat as unproblematic situations of cooperation occurring in an asymmetrical context. The conceptual Framework of Hydro-Hegemony presented herein attempts to give these two features – power and varying intensities of conflict – their respective place in the perennial and deeply political question: who gets how much water, how and why?

Hydro-hegemony is hegemony at the river basin level, achieved through water resource control strategies such as resource capture, integration and containment. The strategies are executed through an array of tactics (e.g. coercion-pressure, treaties, knowledge construction, etc.) that are enabled by the exploitation of existing power asymmetries within a weak international institutional context. Political processes outside the water sector configure basin-wide hydro-political relations in a form ranging from the benefits derived from cooperation under hegemonic leadership to the inequitable aspects of domination. The outcome of the competition in terms of control over the resource is determined through the form of hydro-hegemony established, typically in favour of the most powerful actor.

The Framework of Hydro-hegemony is applied to the Nile, Jordan and Tigris and Euphrates river basins, where it is found that current hydro-hegemonic configurations tend towards the dominative form.. There is evidence in each case of power asymmetries influencing an inequitable outcome – at the expense of lingering, low-intensity conflicts. It is proposed that the framework provides an analytical paradigm useful for examining the options of such powerful or hegemonized riparians and how they might move away from domination towards cooperation.
Perspective: The challenge of ecologically sustainable water management
Authors: Bernhardt Emily , Bunn StuartE. , Hart David D. , Malmqvist Björn , Muotka Timo , Naiman Robert J. , Pringle Catherine , Reuss Martin , Wilgen Brian van
Published: September 2006

Sustainable water resource management is constrained by three pervasive myths; that societal and environmental water demands always compete with one another; that technological solutions can solve all water resource management problems; and that environmental solutions to protect and maintain freshwater resources are more expensive and less dependable than technological solutions. We argue that conservation and good stewardship of water resources can go a long way toward meeting societal demands and values. Furthermore, water requirements to sustain ecosystem health and biodiversity in rivers and their associated coastal systems can be well aligned with options for human use and deliver a suite of ecosystem goods and services to society. However, to achieve ecologically sustainable water management, we propose several key issues that must be addressed. The objective of this opinion paper is to stimulate discussion across traditional discipline boundaries with the aim of forging new partnerships and collaborations to meet this pressing challenge of ecologically sustainable water management.
Effect of Multiple Compartments on Oxygen Transfer in Postaeration Tanks
Authors: Pincince Albert B.
Published: September 2006

National Pollution Discharge Elimination System permits for approximately 5900 wastewater treatment plants in the U.S. include a minimum dissolved oxygen requirement. Of these plants, approximately 2300 have an average flow exceeding 3900 m3/d (1 mgd). To achieve these dissolved oxygen standards, final effluent from some plants is aerated before discharge using cascades or postaeration tanks. Postaeration tanks are typically designed as completely mixed tanks with effluent concentration equal to concentration throughout the tank. The concentration difference that determines rate of oxygen transfer is the saturation concentration minus the effluent concentration.  Oxygen transfer can be made more efficient by dividing the tank into two or more compartments. Because the difference between oxygen deficit in the compartments before the last one is greater than the deficit in the last compartment, the standard oxygen‐transfer rate (SOTR) required with multiple compartments is less than with one compartment. A decrease in SOTR causes the same percent decrease in number of diffusers and diffuser capacity (for diffused‐air systems) or capacity of mechanical aerators. Also, the basin itself can be made smaller. Optimum configuration is obtained when the SOTR for each tank is equal. The most efficient system is a plug‐flow regime, which can be achieved by means of multiple compartments or use of a tank with a high length‐to‐width ratio.
In Situ Treatment of Cyanide‐Contaminated Groundwater by Iron Cyanide Precipitation
Authors: Ghosh Rajat S. , Dzombak David A. , Luthy Richard G. , Smith John R.
Published: September 2006

Groundwater contamination with cyanide is common at many former or active industrial sites. Metal–cyanide complexes typically dominate aqueous speciation of cyanide in groundwater systems, with iron–cyanide complexes often most abundant. Typically, metal–cyanide complexes behave as nonadsorbing solutes In sand–gravel aquifer systems in the neutral pH range, rendering cyanide relatively mobile in groundwater systems. Groundwater pump–and–treat systems have often been used to manage cyanide contamination in groundwater.  This study examined the feasibility of using in situ precipitation of iron cyanide in a reactive barrier to attenuate the movement of cyanide in groundwater. Laboratory column experiments were performed in which cyanide solutions were passed through mixtures of sand and elemental iron filings. Removal of dissolved cyanide was evaluated in a variety of cyanide–containing influents under various flow rates and sand‐to‐iron weight ratios. Long‐term column tests performed with various cyanide–containing influents under both oxic and anoxic conditions, at neutral pH and at flow rates typical of sand–gravel porous media, yielded effluent concentrations of total cyanide as low as 0.5 mg/L. Effluent cyanide concentrations achieved were close to the solubilities of Turnbull's blue–hydrous ferric oxide solid solutions, indicating co‐precipitation of the two solids. Maximum cyanide removal efficiency was achieved with approximately 10% by weight of iron in the sand‐iron mixtures; higher iron contents did not increase removal efficiency significantly. Results obtained indicate that in situ precipitation is a promising passive treatment approach for cyanide in groundwater.
Pilot‐Plant Treatment of a High‐Strength Brewery Wastewater Using a Membrane‐Aeration Bioreactor
Authors: Brindle Keith , Stephenson Tom , Semmens Michael J.
Published: September 2006

The membrane‐aeration bioreactor is a small footprint modular process, suited to on‐site treatment of high‐organic‐strength industrial wastewater. A pilot‐plant membrane‐aeration bioreactor was operated under completely mixed. low‐flow, and plug‐flow conditions during treatment of a high‐strength brewery wastewater. Hydrophobic dead‐end hollow fibers supplied pure oxygen in a bubbleless form to a biofilm attached to the shell side of the fibers. Biofilm development was rapid and fibers were e1eaned regularly to control excessive growth and sloughing. Organic removal rates of 27 kg total chemical oxygen demand/m3·d and removal efficiencies of 81% were achieved during plug‐flow operation. Biodegradation of organic matter within the wastewater was almost exclusively (99.8%) carried out within the biofilm.
Volatile Organic Compound Stripping at Clarifier Weirs
Authors: Zytner R.G. , Rahmé Z.G. , Corsi R.L. , Labocha M. , Parker W.
Published: September 2006

Volatile organic compound (VOC) stripping at clarifier weirs was investigated for both clean water and primary wastewater using a pilot‐scale model with a cross‐sectional geometry similar to clarifier weirs. Drop height, type of flow regime over the weir, and weir shape were identified as important parameters influencing mass transfer. It was also observed that VOC stripping from free‐fall flow could be correlated with Henry's law constant. A model that accounts for liquid‐ and gas‐phase mass transfer was developed to predict VOC stripping from clean water. The relatively low and consistent gas‐ and liquid‐phase mass‐transfer coefficients used in the model suggest that a representative value may apply for all weir conditions. Incorporating a transition coefficient between clean water and wastewater made it possible to predict VOC transfer in primary wastewater based on clean water data. Experimental results and modeling efforts described in this paper could serve as a first step in estimating VOC emissions for flows over clarifiers at wastewater treatment plants.
Light‐enhanced chemical oxidation for tertiary treatment of municipal landfill leachate
Authors: Ince Nilsun H.
Published: September 2006

Three advanced oxidation processes involving hydrogen peroxide, ozone, and ultraviolet (UV)/visible light were investigated for their relative effectiveness in removing refractory organics from biotreated leachate collected at the municipal landfill site of the city of Stuttgart, Germany. The efficiency of each system was compared with respect to the total reduction and the rate of degradation observed in chemical oxygen demand (COD), total dissolved organic carbon (TOC/DOC), and total organic halogens (TOX/AOX) during eight hours of treatment at acidic pHs. The effect of irradiation was investigated by operation of the systems under two different light sources, namely a low‐pressure mercury UV lamp with a maximum emission at 253.7 nm, and a high‐pressure mercury UV‐visible lamp, emitting light from 200 nm to 470 nm, respectively. Hydrogen peroxide‐ (H2O2) added systems with or without ozone (O3) and used with high‐pressure lamps were found adequate for reducing the TOX of the tested leachate to desirable limits. The greatest COD reduction was obtained with the H2O2–O3 system irradiated by low‐pressure lamps. Ozonation without the addition of H2O2 proved inadequate for the tested leachate even under high irradiation intensity.
Automatic control of polymer dose using the streaming current detector
Authors: Abu‐Orf Mohammad M. , Dentel Steven K.
Published: September 2006

A previous phase of this study demonstrated that streaming current (SC) measurements taken from the liquid stream after dewatering can be used to adjust and optimize polymer dosages used for conditioning of wastewater solids. Consequently, use of the streaming current detector (SCD) was evaluated for continuous feedback control of polymer dosing in two full‐scale dewatering facilities. Control was implemented using a slightly negative SC setpoint, and the SCD's ability to control the polymer pumps was assessed when the wastewater solids characteristics changed during routine operation and when controlled additions of ferrous chloride were made. Changes in the solids flow rate were also imposed to assess the control system's response at one facility. At the second wastewater treatment plant, an unexpected change in the polymer also occurred during SCD use, and the system's ability to adjust the polymer dose accordingly was assessed during this incident. Results indicated that the SCD adjusted the polymer feed rate appropriately during all changes in solids flow rate and characteristics and polymer concentrations. The device's success indicates that charge neutralization plays a significant role in solids conditioning and can be used as an indicator of polymer performance and for feedback control of dosage. Routine and thorough cleaning of the SCD's probe with a plastic brush may be necessary in certain applications to maintain consistent control.
Method development for measuring biodegradable organic carbon in reclaimed and treated wastewaters
Authors: Khan Eakalak , Babcock Roger W. , Suffet Irwin H. , Stenstrom Michael K.
Published: September 2006

Analyses that measure oxygen demand, such as biochemical oxygen demand (BOD) and chemical oxygen demand (COD) analyses, have long been used as indicators of contamination and wastewater treatment plant efficiency. They measure the tendency of pollutants to react with oxygen, which is generally a good indicator of the stability or level of treatment. Both parameters include reactions with organic as well as inorganic substances and suffer from a lack of precision and accuracy at low concentrations, which are becoming increasingly more important. Biodegradable dissolved organic carbon (BDOC) analysis is a relatively new procedure that has advantages over both BOD and COD analyses, including insensitivity to inorganic oxidations. A modified BDOC procedure was developed to characterize the performance of advanced treatment methods, such as those used in municipal water reclamation and secondary‐treated wastewaters, where moderately low dissolved organic carbon concentrations (4 to 15 mg/L) are routinely encountered. The development of the modified BDOC procedure was based on a combination of the existing batch BDOC protocol and BOD techniques. Various aspects and incubation conditions were investigated to finalize the procedure. Nitrification does not interfere with the procedure. It is possible to simultaneously determine the soluble BOD (SBOD) under certain conditions. The procedure has reduced variability and increased precision as compared to BOD and COD analyses.
Dual‐chemical conditioning and dewatering of anaerobically digested biosolids: laboratory evaluations
Authors: Chitikela Srinivasarao , Dentel Steven K.
Published: September 2006

Dual‐chemical conditioning of anaerobically digested biosolids was evaluated using either ferric chloride or a cationic surfactant, hexadecyltrimethyl ammonium bromide (HDTMA), followed by a cationic polymer (Percol 757). Significant reductions in the optimal doses of these additives were observed in dual‐chemical conditioning when compared to the dose requirements for either chemical when used individually. Adding a proportion of one chemical's optimum dose reduced the requirement for the other by roughly the same proportion. The use of ferric chloride or HDTMA to reduce the polymer requirement was not cost effective at the facilities involved with this study, but their cost‐effective use will depend, in general, on the polymer in use and the chemical costs relevant to a particular site. Regardless of cost, use of at least some polymer was required to obtain optimal dewaterability. Thus, neutralization of surface charge is necessary in the chemical conditioning of biosolids, but an additional mechanism, likely to be interparticle bridging, also plays a critical role in obtaining the most effective dewatering.