bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparative batch sorption and time-resolved laser fluorescence spectroscopy study on the sorption of Eu(III) and Cm(III) on synthetic and natural kaolinite
Authors: Huittinen N. , Rabung Thomas , Andrieux P. , Lehto Jukka , Geckeis H.
Published: November 2010

Eu(III) and Cm(III) sorption onto synthetic and natural kaolinite (St. Austell, UK) were studied by batch sorption experiments and time-resolved laser fluorescence spectroscopy (TRLFS). All investigations were performed under argon atmosphere (O2<1 ppm). 0.1 M NaClO4and 0.25 g/L kaolinite were used as electrolyte and solid concentrations, respectively, throughout the study. Batch sorption experiments were performed with Eu(III), a homologue to trivalent actinides at three different metal ion concentrations between 6.6×10−8and 6.6×10−6 M. pH-dependent sorption was found to be congruent for the two lowest Eu(III) concentrations (6.6×10−8and 6.6×10−7 M) while a shift of the sorption distribution coefficient,Kd, to higher pH values was observed for the highest metal ion concentration (6.6×10−6 M). Furthermore, the natural kaolinite showed higher uptake of Eu(III) for the lowest metal ion concentration at pH<5 as compared to the synthetic product. This difference is believed to arise from a higher amount of Eu(III) being sorbed as outer-sphere species on the natural kaolinite due to its negative surface charge being higher than that of the synthetic mineral. The spectroscopic investigations were performed with 2×10−7 M Cm(III) as a luminescent probe. Four single component spectra could be extracted from the recorded emission spectra for both the synthetic and the natural kaolinite, with peak positions in average at 598.8, 602.7, 607.4 and 611.0 nm. The three first emission peaks appearing between pH 5 and 13 were assigned to three inner-sphere Cm-complexes. The fourth emission peak appearing in the alkaline pH range (>9) is assumed to be a result of Cm(III) incorporation by a surface precipitate of hitherto unknown composition.
U(VI) sorption on granite: prediction and experiments
Authors: Nebelung Cordula , Brendler Vinzenz
Published: November 2010

One widely accepted approach – component additivity (CA) – to describe the sorption of contaminants onto complex materials such as rocks or soils is based on the assumption that the surface of a complex mineral assemblage is composed of a mixture of mineral constituents whose surface properties are known from independent studies. An internally consistent SCM (surface complexation model) database can be developed that describes the adsorption reactions of solutes to each phase. Here, the capability of such a methodology was tested, using the code MINTEQA2 including thermodynamic data of the NEA-TDB, and literature data for SCM, namely the DDL model.

The sorption characteristics of U(VI) on granite (from Eibenstock, Saxony, Germany, with the main components quartz, albite, orthoclase, and muscovite) was predicted and then compared to batch experiments. Granite plays an important role in the remediation of former uranium ore mining and milling sites, but is also one of the host rocks considered for final disposal of nuclear materials. Safety assessment requires a detailed understanding of this system and its retention potential with regard to hazardous components. Namely the sorption of uranium in this complex rock is not fully understood yet. The experiments thus also provided a better understanding of the far-field behaviour in granitic geological nuclear repositories.

The robustness of the prediction was tested by variation of the granite composition and the variation of the specific surface area (SSA) – first all components were predicted with a uniform granite SSA, second with a distinct SSA for each granite component (determined on pure minerals for the same grain size fractions). Changes in compositions yielded only marginal differences in the prediction. Different approaches to SSA showed somewhat larger deviations.

In conclusion, the CA methodology is a valid and robust approach to U(VI) sorption onto complex substrates such as granite, provided sufficient information on component phases is available. This should help to minimize experimental efforts and to increase confidence into complex SCM computations.
Quantum chemical modeling of uranyl adsorption on mineral surfaces
Authors: Kremleva Alena , Krüger Sven , Rösch Notker
Published: November 2010

We overview quantum mechanical simulations that model the adsorption of actinide ions at solvated mineral surfaces. Pertinent examples illustrate the status of this emerging field of computational chemistry. In particular, we describe our own studies on uranyl adsorption on kaolinite. Already the few available results, from applications of density functional methods to cluster models or periodic slab models, show that such calculations are a useful complement to experimental investigations. Detailed information at the atomic level from accurate electronic structure calculations on well defined model systems helps to refine current interpretations of the chemical nature of uranyl adsorption species and to discover new features of these interface systems. Results from quantum mechanical simulations also provide a valuable reference for future experimental investigations.
Molecular interactions of plutonium(VI) with synthetic manganese-substituted goethite
Authors: Hu Yung-Jin , Kestrel Schwaiger Luna , Booth Corwin H. , Kukkadapu Ravi K. , Cristiano Elena , Kaplan Daniel , Nitsche Heino
Published: November 2010

Plutonium(VI) sorption on the surface of well-characterized synthetic manganese-substituted goethite minerals (Fe1−xMnxOOH) was studied using X-ray absorption spectroscopy. We chose to study the influence of manganese as a minor component in goethite because goethite rarely exists as a pure phase in nature. Manganese X-ray absorption near-edge structure measurements indicated that essentially all the Mn in the goethite existed as Mn(III), even though Mn was added during mineral synthesis as Mn(II). Importantly, energy dispersive X-ray analysis demonstrated that Mn did not exist as discrete phases and that it was homogeneously mixed into the goethite to within the limit of detection of the method. Furthermore, Mössbauer spectra demonstrated that all Fe existed as Fe(III), with no Fe(II) present. Plutonium(VI) sorption experiments were conducted open to air and no attempt was made to exclude carbonate. The use of X-ray absorption spectroscopy allows us to directly and unambiguously measure the oxidation state of plutonium in situ at the mineral surface. Plutonium X-ray absorption near-edge structure measurements carried out on these samples showed that Pu(VI) was reduced to Pu(IV) upon contact with the mineral. This reduction appears to be strongly correlated with mineral solution pH, coinciding with pH transitions across the point of zero charge of the mineral. Furthermore, extended X-ray absorption fine structure measurements show evidence of direct plutonium binding to the metal surface as an inner-sphere complex. This combination of extensive mineral characterization and advanced spectroscopy suggests that sorption of the plutonium onto the surface of the mineral was followed by reduction of the plutonium at the surface of the mineral to form an inner-sphere complex. Because manganese is often found in the environment as a minor component associated with major mineral components, such as goethite, understanding the molecular-level interactions of plutonium with such substituted mineral phases is important for risk assessment purposes at radioactively contaminated sites and long-term underground radioactive waste repositories.
Uranium(VI) diffusion in low-permeability subsurface materials
Authors: Liu Chongxuan , Zhong Lirong , Zachara John M.
Published: November 2010

Uranium(VI) diffusion was investigated in a fine-grained saprolite sediment that was collected from U.S. Department of Energy (DOE) Oak Ridge site, TN, where uranium contamination in groundwater is a major environmental concern. U(VI) diffusion was studied in a diffusion cell with one cell end in contact with a large, air-equilibrated electrolyte reservoir. The pH, carbonate and U(VI) concentrations in the reservoir solution were varied to investigate the effect of solution chemical composition and uranyl speciation on U(VI) diffusion. The rates of U(VI) diffusion were evaluated by monitoring the U(VI) concentration in the reservoir solution as a function of time; and by measuring the total concentration of U(VI) extracted from the sediment as a function of time and distance in the diffusion cells. The estimated apparent rate of U(VI) diffusion varied significantly with pH, with the slowest rate observed at pH 7 as a result of strong adsorptive retardation. The estimated retardation factor was generally consistent with a surface complexation model. Numerical simulations indicated that a species-based diffusion model that incorporated both aqueous and surface complexation reactions was required to describe U(VI) diffusion in the low permeability material under variable geochemical conditions. Our results implied that low permeability materials will play an important role in storing U(VI) and attenuating U(VI) plume migration at circumneutral pH conditions, and will serve as a long-term source for releasing U(VI) back to the nearby aquifer during and after aquifer decontamination.
Distribution of Cs and Am in the solution-bentonite colloids-granite ternary system: effect of addition order and sorption reversibility
Authors: Iijima Kazuki , Tomura T. , Tobita M. , Suzuki Y.
Published: November 2010

Bentonite colloids may be generated from bentonite in the geological disposal system planned in Japan, and sorb radionuclides (RNs) thus facilitating migration. In this context, distribution coefficients and reversibility of the sorption of RNs onto colloids are sensitive factors in safety assessment. In this study, distribution behavior of Cs and Am in the synthetic groundwater-bentonite colloids-granite ternary system was investigated by batch methods. To evaluate the sorption reversibility, three series with different addition order of components were prepared, such as CR+G corresponding to the series beginning with a colloid (C)–RN (R) solution binary system followed by addition of granite (G) after around 100 d, GR+C and CG+R. Distribution coefficients for the bentonite colloids (R
d,col) interaction with Cs obtained in CR+G and CG+R are similar to calculated value (6.7–15 m3 kg−1) based on a previously reported sorption model, while that of GR+C is higher. Considering the contribution of micaceous colloids generated from granite, high R
d,col in GR+C can be explained. The experimental R
d,col data for Am in each series show similar values and agree well with calculation results (7.6×103–8.7×103 m3 kg−1) by applying the sorption models. Therefore, it is concluded that the sorption behavior of Cs and Am onto the bentonite colloids are reversible and the sorption models developed in the binary system are applicable to the ternary system. Interaction of Cs with granite shows slow kinetics both in sorption and desorption process. The K
d,gra values for Am in CR+G are lower than those of other series just after addition of granite, however, they gradually increase with time and finally congruent values are attained. The concentration of free Am in CR+G is one order of magnitude higher than that in GR+C in spite of the ternary system under similar chemical conditions of the solution, suggesting temporal generation of species such as colloidal Am which is not sorbed on granite in CR+G.
Influence of Birth Hospital on Outcomes of Ductal-Dependent Cardiac Lesions
Authors: Bennett Tellen D. , Klein Matthew B. , Sorensen Mathew D. , De Roos Anneclaire J. , Rivara Frederick P.
Published: November 2010

OBJECTIVE:

The goal was to determine the effect of birth hospital pediatric cardiac specialty center status and neonatal level of care on 90-day mortality for infants with ductal-dependent congenital heart disease.

METHODS:

A population-based, retrospective, cohort study was conducted in Washington State in 1987–2006. All infants born in Washington with gestational ages of ≥32 weeks and birth weights of ≥1500 g who were admitted to a Washington hospital for the care of a congenital cardiac anomaly likely to be ductal dependent were included. Subjects were required to receive a surgical or interventional cardiac procedure within 30 days after birth. Birth certificate data were linked with death certificate data and hospital administrative records. The exposures of interest were birth hospital pediatric cardiac specialty center status and neonatal level of care. The primary outcome was death within 90 days.

RESULTS:

A total of 823 infants met the inclusion criteria, 285 born at specialty centers and 538 at other centers. After adjustment for cardiac diagnoses, other congenital anomalies, birth year, maternal income quartile, and definitive-care hospital, there was no significant difference in 90-day mortality for infants born at specialty centers versus other centers (odds ratio: 1.05 [95% confidence interval: 0.65–1.68]).

CONCLUSION:

For infants with ductal-dependent congenital heart disease, there was no difference in 90-day mortality for infants born at specialty centers versus other centers in the state of Washington.
Therapeutic Acetaminophen Is Not Associated With Liver Injury in Children: A Systematic Review
Authors: Lavonas Eric J. , Reynolds Kate M. , Dart Richard C.
Published: November 2010

BACKGROUND:

Concern exists about the potential for liver injury with therapeutic dosing of acetaminophen in children.

OBJECTIVE:

We systematically reviewed the medical literature to determine the rate at which liver injury has been reported for children prescribed therapeutic doses of acetaminophen (≤75 mg/kg per day orally or intravenously or ≤100 mg/kg per day rectally).

METHODS:

We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials to locate all studies in which acetaminophen was administered to a defined pediatric population for ≥24 hours and for all case reports of liver injury after therapeutic acetaminophen dosing. Trained reviewers extracted data from each report. Major and minor hepatic adverse events (AEs) were defined prospectively. Causality was assessed by using the Naranjo algorithm.

RESULTS:

A total of 62 studies that enrolled 32 414 children were included. No child (0% [95% confidence interval: 0.000–0.009]) was reported to have exhibited signs or symptoms of liver disease, to have received an antidote or transplantation, or to have died. Major or minor hepatic AEs were reported for 10 children (0.031% [95% confidence interval: 0.015–0.057]). The highest transaminase value reported was 600 IU/L. Naranjo scores (2–3) suggested “possible” causation. Twenty-two case reports were identified. In 9 cases, the Naranjo score suggested “probable” causation (5–6).

CONCLUSIONS:

Hepatoxicity after therapeutic dosing of acetaminophen in children is rarely reported in defined-population studies. Case reports suggest that this phenomenon may occur, but few reports contain sufficient data to support a probable causal relationship.
Food Insecurity: Could School Food Supplementation Help Break Cycles of Intergenerational Transmission of Social Inequalities?
Authors: Roustit Christelle , Hamelin Anne-Marie , Grillo Francesca , Martin Judith , Chauvin Pierre
Published: November 2010

OBJECTIVE:

The aim of our study was to investigate the moderating effect of school food programs in schools in disadvantaged neighborhoods on the association between household food insecurity and scholastic difficulties among adolescents.

METHODS:

We analyzed data from the Social and Health Survey of Children and Adolescents in Quebec, Canada, which was conducted in 1999 and included 2346 adolescent students 13 and 16 years of age (and 1983 of their parents). Sample-weighted regression analyses were performed to determine the association between household food insecurity and school difficulties and to explore the moderating role of food supplementation programs with respect to this association.

RESULTS:

Household food insecurity, which was linked to the indicators of family socioeconomic status, was strongly associated with the indicators of scholastic difficulties. This association disappeared for adolescents who benefited from food supplementation programs in schools in disadvantaged neighborhoods. The risk of school activity limitation decreased from OR = 2.76 (95% confidence interval [CI]: 1.41–5.41) to OR = 1.57 (95% CI: 1.35–3.40), the risk of below-average grades in the language of instruction decreased from OR = 2.19 (95% CI: 1.28–3.74) to OR = 0.59 (95% CI: 0.21–1.63), the risk of repeating a year decreased from OR = 2.14 (95% CI: 1.35–3.40) to OR = 0.87 (95% CI: 0.42–1.81), and the risk of self-rated poor academic performance decreased from OR = 1.74 (95% CI: 1.08–2.81) to OR = 0.81(95% CI: 0.37–1.78).

CONCLUSION:

School food supplementation is a moderating factor in the association between household food insecurity and scholastic difficulties for adolescents.
Risk Factors in Children Hospitalized With RSV Bronchiolitis Versus Non–RSV Bronchiolitis
Authors: García Carla G. , Bhore Rafia , Soriano-Fallas Alejandra , Trost Margaret , Chason Rebecca , Ramilo Octavio , Mejias Asuncion
Published: November 2010

BACKGROUND:

The trends in hospitalization rates and risk factors for severe bronchiolitis have not been recently described, especially after the routine implementation of prophylaxis for respiratory syncytial virus (RSV) infections.

OBJECTIVES:

To define the burden of hospitalizations related to RSV and non-RSV bronchiolitis in a tertiary-care children's hospital from 2002 to 2007 and to identify the risk factors associated with severe disease.

METHODS:

Medical records of patients hospitalized for bronchiolitis were reviewed for demographic, clinical, microbiologic, and radiologic characteristics as well as the presence of underlying medical conditions. Differences were evaluated between children with RSV and non-RSV bronchiolitis, and multivariable logistic regression analyses were performed to identify independent risk factors for severe disease.

RESULTS:

Bronchiolitis hospitalizations in children younger than 2 years old (n = 4800) significantly increased from 536 (3.3%) in 2002 to 1241 (5.5%) in 2007, mainly because of RSV infections. Patients with RSV bronchiolitis (n = 2840 [66%]) were younger at hospitalization and had a lower percentage of underlying medical conditions than children hospitalized with non-RSV bronchiolitis (27 vs 37.5%; P < .001). However, disease severity defined by length of hospitalization and requirement of supplemental oxygen, intensive care, and mechanical ventilation was significantly worse in children with RSV bronchiolitis. RSV infection and prematurity, regardless of the etiology, were identified as independent risk factors for severe bronchiolitis.

CONCLUSIONS:

There was a significant increase in hospitalizations for RSV bronchiolitis from 2002 to 2007. A majority of the children with RSV bronchiolitis were previously healthy, but their disease severity was worse compared with those hospitalized with non-RSV bronchiolitis.
Left Vocal Cord Paralysis After Extreme Preterm Birth, a New Clinical Scenario in Adults
Authors: Røksund Ola Drange , Clemm Hege , Heimdal John Helge , Aukland Stein Magnus , Sandvik Lorentz , Markestad Trond , Halvorsen Thomas
Published: November 2010

OBJECTIVE:

The goal was to study the incidence and long-term consequences of left vocal cord paralysis (LVCP) after neonatal surgical treatment of patent ductus arteriosus (PDA) in a population-based cohort of adults who were born at gestational ages of ≤28 weeks or with birth weights of ≤1000 g in western Norway.

METHODS:

Subjects with a history of neonatal PDA surgery were examined with transnasal flexible laryngoscopy, and those with LVCP were examined with continuous laryngoscopy during maximal treadmill exercise (continuous laryngoscopy exercise testing). All subjects underwent lung function testing, ergospirometry, and pulmonary high-resolution computed tomography. Symptoms were recorded with a questionnaire.

RESULTS:

Forty-four (86%) of 51 eligible preterm infants participated in the study, 13 (26%) had a history of PDA surgery and 7 (54%) had LVCP, with the laryngeal appearances varying slightly. As a group, subjects with LVCP had significant airway obstruction, no decreases in aerobic capacity, and no obvious evidence of longstanding aspiration on high-resolution computed tomography scans. The continuous laryngoscopy exercise tests revealed increasing respiratory symptoms in parallel with increasing anteromedial collapse of the left aryepiglottic folds as the exercise load increased. Hoarseness and voice-related symptoms were the most typical complaints. Symptoms were attributed erroneously to other diseases for at least 2 subjects.

CONCLUSIONS:

LVCP is not uncommon in young adults exposed to PDA surgery as preterm infants. The condition may be overlooked easily, and symptoms may be confused with those of other diseases. Laryngoscopy should be offered on the basis of liberal indications after PDA ligation.
Late-Preterm Birth and Its Association With Cognitive and Socioemotional Outcomes at 6 Years of Age
Authors: Talge Nicole M. , Holzman Claudia , Wang Jianling , Lucia Victoria , Gardiner Joseph , Breslau Naomi
Published: November 2010

INTRODUCTION:

Late-preterm birth (34–36 weeks' gestation) has been associated with a risk for long-term cognitive and socioemotional problems. However, many studies have not incorporated measures of important contributors to these outcomes, and it is unclear whether effects attributed to gestational age are separate from fetal growth or its proxy, birth weight for gestational age.

METHOD:

Data came from a study of low- and normal-weight births sampled from urban and suburban settings between 1983 and 1985 (low birth weight, n = 473; normal birth weight; n = 350). Random sampling was used to pair singletons born late-preterm with a term counterpart whose birth weight z score was within 0.1 SD of his or her match (n = 168 pairs). With random-effects models, we evaluated whether pairs differed in their IQ scores and teacher-reported behavioral problems at the age of 6 years.

RESULTS:

In adjusted models, late-preterm birth was associated with an increased risk of full-scale (adjusted odds ratio [aOR]: 2.35 [95% confidence interval (CI): 1.20–4.61]) and performance (aOR: 2.04 [95% CI: 1.09–3.82]) IQ scores below 85. Late-preterm birth was associated with higher levels of internalizing and attention problems, findings that were replicated in models that used thresholds marking borderline or clinically significant problems (aOR: 2.35 [95% CI: 1.28–4.32] and 1.76 [95% CI: 1.04–3.0], respectively).

CONCLUSIONS:

Late-preterm birth is associated with behavioral problems and lower IQ at the age of 6, independent of maternal IQ, residential setting, and sociodemographics. Future research is needed to investigate whether these findings result from a reduction in gestational length, in utero (eg, obstetric complications) or ex-utero (eg, neonatal complications) factors marked by late-preterm birth, or some combination of these factors.
Queer Pedagogy and/in Religious Studies
Authors: Schippert Claudia
Published: November 2010

An Introduction to the Special Issue of the Bulletin. The essays emerged out of a panel discussion co-sponsored by the “Queer Theory and LGBT Studies Consultation” and the “Teaching Religion Section” at the 2009 Annual Meeting of the American Academy of Religion. Contributors were invited to produce reflections on teaching religion queerly, teaching religion as a queer thing, subverting conventional definitions of (the) discipline, and teaching religion outside of religious studies departments/programs, among other possible topics.
Freaks and Queers in the Study of Religion
Authors: Wilcox Melissa
Published: November 2010

What does is mean to be a freak - a chimera - in the study of religion? What does it mean to be queer? This paper explores the effects of freakishness and queerness on hiring practices and academic success, arguing that those scholars who embody such forms of Otherness are particularly vulnerable to the insidious complaint of "lack of fit." The second half of the article considers the role of "freakish" and "queer" religions in the classroom, asking what value such religions can have for teaching and what role social justice plays in the pedagogy surrounding the teaching of (and by) freaks and queers.
“It’s Queer Up in Here!”
Authors: Lassiter Kate , Tucker Andrea
Published: November 2010

How is queer pedagogy already being performed in a Divinity school classroom? Using the work of Judith Butler and their own reflections as scholars in training, the authors describe how a queer pedagogy that refuses to split religious studies and theological studies is already at work in the Divinity classroom. The authors argue that the categories of excess, experience, and performance are categories in a queer pedagogy that refuses binaries. They conclude with two suggestions of queer pedagogical practice.
Looking For Religion in All the Wrong Places
Authors: Burlein Ann
Published: November 2010

Drawing on recent work in secularism, this paper argues that religion exerts force in modern culture without anyone needing to beleive or practice a particular religion. This is especially the case with respect issues of sexuality. The paper uses the Introductory course as a way of exploring how, when it comes ot sexuality, religion still speaks us.
Estruturação da estrutura organizacional: o caso de uma empresa familiar
Authors: Machado-da-Silva Clóvis L. , Fonseca Valéria Silva da
Published: November 2010

Este artigo apresenta os resultados de uma investigação realizada em uma organização familiar, cujo arranjo formal sofreu algumas alterações nos últimos anos. Administrada com base em valores conservadores disseminados pelos fundadores, a organização possuia inicialmente uma configuração estrutural consistente com os princípios de um sistema de gestão tradicional. Ao longo do tempo, perante à força de orientações institucionais e de circunstâncias situacionais, surge a necessidade de implantar ações modernizadoras, condizentes com uma filosofia de gestão mais profissional, acarretando, consequentemente, a reformulação do arranjo formal. Considera-se que os padrões institucionais e as circunstâncias situacionais atuaram como propulsores da dinâmica de funcionamento da organização focalizada, cujo entendimento, efetuado de acordo com os valores predominantes em seu universo simbólico, ocasionou a estruturação da estrutura organizacional.
Competitividade organizacional: uma tentativa de reconstrução analítica
Authors: Machado-da-Silva Clóvis L. , Fonseca Valéria Silva da
Published: November 2010

Neste final de século, o processo de globalização dos mercados e seu efeito sobre os padrões de conduta econômica, política, social e organizacional, vêm assumindo importância crescente, compondo um cenário no qual a competitividade emerge como uma questão imperativa. Em decorrência, intensificam-se na literatura especializada as discussões em torno da necessidade de elaboração de um conceito de competitividade mais claro e abrangente, que transcenda a tendência existente no campo da microeconomia de associá-la somente à indicadores de desempenho ou de eficiência técnica. Para tanto, economistas menos ortodoxos têm sugerido vinculações a fatores como estratégia e padrões de concorrências setoriais, estudiosos organizacionais têm enfatizado mecanismos de seleção e de exclusão competitiva, pressupondo a relevância de se considerar a influência das circunstâncias ambientais. No entanto, na essência tais abordagens ainda se concentram na avaliação da eficiência de aspectos organizacionais. Acredita-se que o problema reside no fato de ambas confinarem o seu tratamento do ambiente aos limites do mercado ou de uma população de organizações, menosprezando a força das pressões que os rodeiam. Esse é foco de análise da teoria institucional. Portanto, pretende-se apresentar no presente artigo alguns pressupostos da teoria microeconômica e da teoria institucional, e demonstrar seu potencial de interseção e de consequente aplicação ao exame mais apurado do fenômeno da competitividade.
Estrutura, agência e interpretação: elementos para uma abordagem recursiva do processo de institucionalização
Authors: Machado-da-Silva Clóvis L. , Fonseca Valéria Silva da , Crubellate João Marcelo
Published: November 2010

A teoria neo-institucional tem sido caracterizada por alguns estudiosos do campo dos estudos organizacionais como uma abordagem supostamente determinística. Demonstramos no presente ensaio teórico que tal caracterização não pode ser impingida à perspectiva neo-institucional de maneira generalizada, mas apenas a uma leitura dicotômica dela, típica de visões monoparadigmáticas do processo de institucionalização. A partir dessa demonstração, defendemos a idéia da teoria institucional como teoria multiparadigmática. Para tanto, apresentamos argumentos em favor de uma abordagem recursiva do processo de institucionalização, ressaltando que as noções de estrutura, agência e interpretação são mais apropriadamente tratadas quando definidas como elementos fundamentais da institucionalização como processo recorrente, garantido e condicionado, não determinado, por certo grau de estabilização dos sistemas sociais. Concluímos o ensaio com considerações metodológicas sobre as conseqüências do uso da proposta de abordagem sistêmicoprocessual recorrente da institucionalização para o desenvolvimento de pesquisas no campo dos estudos organizacionais.
Treatment of Class II Molar Furcation Involvement: Meta‐Analyses of Reentry Results
Authors: Kinaia Bassam Michael , Steiger Jacob , Neely Anthony L. , Shah Maanas , Bhola Monish
Published: November 2010

Background: Predictable regeneration of lost periodontal tissues in furcations is difficult to achieve. This paper investigates the efficacy of different treatment modalities for Class II molar furcations.

Methods: Publications in English were searched using PubMed, Medline, and Cochrane Library databases combined with hand searching from January 1, 1966 to October 1, 2007. The search included randomized controlled human trials in molar Class II furcations with over 6 months of surgical reentry follow‐up. Changes in vertical probing depths, vertical attachment levels, and vertical and horizontal bone levels were compared.

Results: The search identified 801 articles of which 34 of 108 randomized clinical trials met the criteria. Thirteen trials had test and control arms allowing three meta‐analyses: 1) five comparing non‐resorbable versus resorbable membranes, 2) five comparing non‐resorbable membranes versus open flap debridement and 3) three comparing resorbable membranes versus open flap debridement. There was significant improvement for resorbable versus non‐resorbable membranes mainly in vertical bone fill (0.77 ± 0.33 mm; [95% CI; 0.13, 1.41]). Non‐resorbable membranes showed significant improvement in vertical probing reduction (0.75 ± 0.31 mm; [95% CI; 0.14, 1.35]), attachment gain (1.41 ± 0.46 mm; [95% CI; 0.50, 2.31]), horizontal bone fill (1.16 ± 0.29 mm; [95% CI; 0.59, 1.73]), and vertical bone fill (0.58 ± 0.11 mm; [95% CI; 0.35, 0.80]) over open flap debridement. Resorbable membranes showed significant improvement in vertical probing reduction (0.73 ± 0.16 mm; [95% CI; 0.42, 1.05]), attachment gain (0.88 ± 0.16 mm; [95% CI; 0.55, 1.20]), horizontal bone fill (0.98 ± 0.12 mm; [95% CI; 0.74, 1.21]) and vertical bone fill (0.78 ± 0.19 mm; [95% CI; 0.42, 1.15]) over open flap debridement.

Conclusions: Guided tissue regeneration with the use of resorbable membranes was superior to non‐resorbable membranes in vertical bone fill. Both types of membranes were more effective than open flap debridement in reducing vertical probing depths and gaining vertical attachment levels and in gaining vertical and horizontal bone.
One‐Stage Full‐Mouth Disinfection as a Therapeutic Approach for Generalized Aggressive Periodontitis
Authors: Aimetti Mario , Romano Federica , Guzzi Nicoletta , Carnevale Gianfranco
Published: November 2010

Background: Data concerning treatment outcomes in patients with generalized aggressive periodontitis (GAgP) are limited. The aim of this study is to investigate 6‐month clinical and microbiologic outcomes of the one‐stage full‐mouth disinfection (OSFMD) in the management of patients with GAgP.

Methods: Twenty‐seven patients with advanced GAgP were included in this prospective follow‐up intervention study. Clinical and microbiologic parameters were collected at baseline and 3 and 6 months after the OSFMD. Patient‐, tooth‐, and site‐level analyses were carried out. Subgingival samples from moderate (4 to 5 mm) and deep (≥6 mm) pocket sites were analyzed using a polymerase chain reaction for Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia (previously T. forsythensis), and Treponema denticola.

Results: The OSFMD resulted in significant improvements in all parameters. After 6 months, the whole‐mouth probing depth (PD) decreased from 4.2 ± 1.1 mm to 2.8 ± 0.6 mm, and the clinical attachment level was reduced from 4.5 ± 1.2 mm to 3.4 ± 1.1 mm (P <0.001). When data were analyzed based on the frequency distribution of PD, the number of sites with PD ≥5 mm decreased by 61% from baseline values, and mean PD reductions of 1.5 and 2.5 mm were noted in moderate and deep pockets, respectively. At 6 months, percentages of moderate and deep sites free of pathogens were 40% and 27%, respectively.

Conclusion: The OSFMD may be a viable approach to deal with severe GAgP.
Effects of Platelet‐Rich Plasma on Sinus Bone Graft: Meta‐Analysis
Authors: Bae Ji‐Hyun , Kim Young‐Kyun , Myung Seung‐Kwon
Published: November 2010

Background: This meta‐analysis investigates the effects of platelet‐rich plasma (PRP) on the sinus bone graft.

Methods: PubMed, the Cochrane Library, and EMBASE were searched in January 2010.

Results: Of 61 articles searched, eight controlled clinical trials, which included a total of 352 sinus bone graft cases in 191 patients, were included in the final analysis. In the fixed‐effects meta‐analysis, the implant survival was not significantly different between two groups in the patient‐based data of four studies (relative risk [RR]: 1.02; 95% confidence interval [CI]: 0.97 to 1.08) and in the implant‐based data of three studies (RR: 1.02; 95% CI: 0.99 to 1.04). The bone formation was significantly greater in the intervention group in the random‐effects model (standardized mean difference [SMD]: 1.30; 95% CI: 0.21 to 2.39) in five studies with significant heterogeneity (I2 = 76.2%). The bone‐to‐implant contact was not significantly different between two groups in the random‐effects model (SMD: 1.02; 95% CI: −1.65 to 3.70) in two studies with significant heterogeneity (I2 = 82.4%).

Conclusion: The present study indicates that there was sufficient evidence to support the use of PRP for bone formation on a sinus bone graft, whereas there was no significant effect on the implant survival and bone‐to‐implant contact.
Sensitivity of the Periodontal Pathogen Aggregatibacter actinomycetemcomitans at Mildly Acidic pH
Authors: Bhattacharjee Mrinal K. , Childs Claiborne B. , Ali Emdad
Published: November 2010

Background: Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), a capnophilic facultative anaerobe, is associated with localized aggressive periodontitis and endocarditis. When grown in broth, the cells begin to die rapidly after overnight growth. The cells also often lose viability on plates within a few days. The aim of this study is to identify the cause of the rapid loss of cell viability.

Methods: Cell viabilities, as measured by colony forming units, were determined for cells obtained from isolated colonies and from the dense part of a streak on plates. The effect of pH on cell viability was determined by growing cells in broth at various initial glucose concentrations and with or without added bicarbonate.

Results: A. actinomycetemcomitans cells were highly sensitive to even a mildly acidic pH of ≈6. Because the bacteria grew at a glucose concentration that is commonly used in many laboratories, there was a dramatic decrease in cell viability as the pH went <6, which happened long before the culture reached saturation. This was easily avoided by using a lower initial glucose concentration, and under these conditions, the addition of bicarbonate to the growth medium was not necessary. Cells resuspended in buffer without nutrients lost viability much faster at pH 6 than at a higher pH. On plates, the cell viability was much higher in isolated colonies than in the dense area of the streak.

Conclusions: A. actinomycetemcomitans cells rapidly lost viability at even a mildly acidic pH. The problem was easily rectified by growing cells at a low glucose concentration.
Stress Anisotropy, Long-Term Reservoir Flow Regimes and Production Performance in Tight Gas Reservoirs
Authors: Bahrami Hassan , Rezaee M. Reza , Asadi M. Sadegh
Published: November 2010

Tight gas reservoirs normally have production problems due to very low matrix permeability and different damage mechanisms during drilling, completion and stimulation. Tight reservoirs need advanced drilling and completion techniques to efficiently connect wellbore to the formation open natural fractures and produce gas at commercial rates.

Stress regimes have significant influence on tight gas reservoirs production performance. The stress regimes cause wellbore instability issues while drilling, which can result in large wellbore breakouts. The stress regimes can also control the well long-term production performance, since they affect permeability anisotropy. The preferred horizontal flow direction is expected to be parallel to the maximum in situ horizontal stress. The production and welltest data in non-fractured as well as hydraulically fractured wells in tight reservoirs have indicated the presence of a long-term linear flow regime due to the well and reservoir geometry and also as a result of the permeability anisotropy.

The stress anisotropy leads to different permeabilities in different directions, and the natural fractures that are aligned with maximum horizontal stress; they might have larger aperture and greater permeability. Due to the more severe stress anisotropy in tight formations, permeability in maximum stress direction might significantly be larger than permeability in the direction of minimum stress.

This study represents evaluation of parameters that might control well productivity and long-term well production performance in tight gas reservoirs. Geomechanical modeling is performed in order to understand the effect of stress anisotropy on aperture evolution of natural fractures in different directions. Furthermore, single well reservoir simulation study is performed in order to generate pressure build-up data for a typical tight gas reservoir, in order to evaluate effect of reservoir geometry and permeability anisotropy on late time linear flow regime, and also assess the well production performance for different well and reservoir conditions.
Comparative study of different formulations and solution methods for two phase flow in saturated porous media
Authors: Mathew Mini , Mohan Kumar M. S.
Published: November 2010

Six models (Simulators) are formulated and developed with all possible combinations of pressure and saturation of the phases as primary variables. A comparative study between six simulators with two numerical methods, conventional simultaneous and modified sequential methods are carried out. The results of the numerical models are compared with the laboratory experimental results to study the accuracy of the model especially in heterogeneous porous media. From the study it is observed that the simulator using pressure and saturation of the wetting fluid (PW, SW formulation) is the best among the models tested. Many simulators with nonwetting phase as one of the primary variables did not converge when used along with simultaneous method. Based on simulator 1 (PW, SW formulation), a comparison of different solution methods such as simultaneous method, modified sequential and adaptive solution modified sequential method are carried out on 4 test problems including heterogeneous and randomly heterogeneous problems. It is found that the modified sequential and adaptive solution modified sequential methods could save the memory by half and as also the CPU time required by these methods is very less when compared with that using simultaneous method. It is also found that the simulator with PNW and PW as the primary variable which had problem of convergence using the simultaneous method, converged using both the modified sequential method and also using adaptive solution modified sequential method. The present study indicates that pressure and saturation formulation along with adaptive solution modified sequential method is the best among the different simulators and methods tested.
Exposure assessment of metal intakes from drinking water relative to those from total diet in Japan
Authors: Ohno Koichi , Ishikawa Kohei , Kurosawa Yuki , Matsui Yoshihiko , Matsushita Taku , Magara Yasumoto
Published: November 2010

Daily intakes of 17 metals (boron, aluminium, chromium, manganese, nickel, copper, zinc, arsenic, selenium, molybdenum, cadmium, antimony, lead, uranium, magnesium, calcium, and iron) via drinking water and total diet were investigated in six cities in Japan. The daily metal intakes were estimated and compared with tolerable daily intake (TDI) values proposed by the WHO or Joint FAO/WHO Expert Committee on Food Additives for toxic metals and with recommended dietary allowances (RDAs) or adequate intake (AI) values proposed for essential metals by the Japanese Ministry of Health, Labour and Welfare. Among the 13 toxic metals, mean dietary intakes of 10 (except arsenic, selenium, and molybdenum) were less than 50% of TDI, suggesting that for these 10 metals the allocation of intake to drinking water in establishing guidelines or standards could possibly be increased from the normal allocation of 10–20% of TDI. For the 13 toxic metals, the contribution of drinking water to TDI was 2% or less in all six cities. Mean dietary intakes of the essential elements magnesium, calcium, and iron were less than the RDA or AI values. Drinking water did not contribute much to essential metal intake, accounting for less than 10% of RDA or AI.
Relationship between land use and water quality in a small watershed in South Korea
Authors: Lee J. Y. , Yang J. S. , Kim D. K. , Han M. Y.
Published: November 2010

Recent research and monitoring undertaken by various institutions have emphasized measurements of river-water quality. Based on the results, government agencies have set guidelines to improve river-water quality management. However, the relationship between water quality and land use/land cover (LULC) has not been examined closely in South Korea to date. This study investigated this relationship in the Imgok River watershed. For this study, the relationship between water quality parameters, e.g. metallic ions, biological oxygen demand and chemical oxygen demand (BOD and COD), NH3, NO3 and PO4 levels and land-use types (abandoned mine land, forest/grassland, agricultural, livestock and residential areas) was examined by correlation analysis with significant level (p < 0.05) and principal component analysis (PCA). Applying PCA to water quality parameters according to land-use coverage, the principal component impacting river water quality were found to be the pH, metallic ions, BOD, PO4, COD and total suspended solids (TSS) for abandoned mine land (AML) coverage; BOD, NO3 and PO4 for forest/grassland areas; TSS, NO3, and PO4 for agricultural land; BOD, COD, NH3 and NO3 for livestock coverage; and BOD, COD, NH3 and PO4 for residential areas. For the AML, the pH exhibited a significant negative correlation with other water quality parameters at the significant level (p < 0.05). Grassland showed significant positive correlations of BOD with values of 0.837 NO3 and 0.514 PO4. In agricultural land, TSS had a significant negative correlation with value of −0.772 PO4. For livestock coverage, BOD had significant positive correlations with values of 0.865 COD, 0.629 NH3, 0.709 NO3 and 0.472 TSS. In residential areas, COD was significantly positively correlated with values of 0.988 BOD and 0.856 PO4, and TSS was highly positively correlated with value of 0.810 NO3 but highly negatively correlated with value of −0.702 PO4. Based on the above, LULC is a significant factor to influence on river water quality and this relationship should be based on the management plan for river water quality control. Future work will be conducted to take more samples in the entire river and season, to run water quality model and to choose a new method for better analysis and more accurate relationship between land-use and water quality.
Fecal coliform removal in a sulfate reduction, autotrophic denitrification and nitrification integrated (SANI) process for saline sewage treatment
Authors: Abdeen Safra , Di Wu , Hui Lu , Chen Guang-Hao , van Loosdrecht Mark C. M.
Published: November 2010

The Sulfate Reduction, Autotrophic Denitrification, Nitrification Integrated (SANI) process has been specially designed to treat saline wastewater. In the process no biological excess sludge is produced. SANI process also has the added advantages of cost and footprint reduction when compared to traditional activated sludge processes. In the SANI pilot plant, the fecal coliform removal efficiency in the sulfate reducing up-flow sludge bed (SRUSB) was found to be 1.4 log, whereas that in the subsequent anoxic and aerobic reactors it was 0.6 and 0.2 log, respectively, leading to a relatively high overall coliform removal of 2.2 log. Sulfide was confirmed to be toxic to fecal coliform and the contact time between the sulfide produced and coliform in the SRUSB played an important role in the removal.
Economic analyses for optimizing the construction of separate sewer in a hybrid sewer system
Authors: Chen Home-Ming , Lo Shang-Lien
Published: November 2010

Metropolitan Taipei located in north Taiwan uses a hybrid sewer system consisting of mostly separate sewer for the populated regions, and partly combined sewer for less populated regions. This study used the concept that Marginal Cost of Control (MCC) equals to Marginal Benefits of Control (MBC) to establish the method for studying the optimal household connection percentage, and the most cost-effective construction of the separate sewer in the hybrid sewer system. Results indicate the improvement of the receiving water quality in a cost-effective analysis manner. The most cost-effective sanitary sewer construction can be reached when the stream Biochemical Oxygen Demand (BOD5) meets the river quality standard, which can be applied in other cities and existing systems.