bluuebunny/crossref_metadata_2025 huggingface dataset:
Contribuições ao estudo dos valores pessoais, laborais e organizacionais
Authors: Tamayo Alvaro
Published: February 2008

Este trabalho teve por objetivo fazer um breve histórico do meu interesse pelo estudo dos valores e discutir algumas das minhas contribuições científicas na área dos valores pessoais, laborais e organizacionais. O estímulo para escrever este texto foi o recebimento do título de professor emérito da Universidade de Brasília. Inicialmente, descrevi a minha trajetória de ensino e de pesquisa na Université de Moncton, no Canadá e na Universidade de Brasília. Os elementos discutidos neste relato representam indicadores da minha contribuição ao estudo dos valores pessoais, laborais e organizacionais.
O 18 Brumário e a análise de classe contemporânea
Authors: Perissinotto Renato Monseff
Published: February 2008

Este artigo considera O 18 Brumário de Louis Bonaparte uma espécie de súmula que condensa todas as dificuldades inerentes à análise de classe da política. O artigo está dividido em cinco partes. Na primeira, são analisadas as passagens de O 18 Brumário que enunciam algumas proposições fundamentais acerca da análise política de classe; na segunda, mostra-se que a literatura marxista contemporânea não solucionou os problemas identificados em relação às proposições marxianas; as terceira e quarta partes discutem algumas perspectivas alternativas (classistas e não - classistas) ao marxismo; por fim, à guisa de conclusão, faz-se algumas reflexões sobre modos possíveis de operacionalizar a análise de classe da política e sobre os problemas a serem enfrentados nesses casos.
Prognostic factors for perioperative pulmonary events among patients undergoing upper abdominal surgery
Authors: Sakai Rafael Luis , Abrão Graciela Maria Gera , Ayres José Franscisco Vasques , Vianna Pedro Thadeu Galvão , Carvalho Lídia Raquel de , Castiglia Yara Marcondes Machado
Published: February 2008

CONTEXT AND OBJECTIVE: The significant relationship between upper abdominal surgery and early (perioperative) pulmonary events was investigated among patients with preoperative pulmonary conditions undergoing general anesthesia. DESIGN AND SETTING: Retrospective study for which data were obtained prospectively from 1999 to 2004, at a tertiary university hospital. METHODS: We retrospectively studied 3107 patients over 11 years old presenting American Society of Anesthesiologists (ASA) status I, II or III who underwent upper abdominal surgery under general anesthesia and were discharged to the recovery room. The preoperative conditions analyzed using logistic regression were: age, sex, ASA physical status, congestive heart failure, asthma, chronic obstructive pulmonary disease (COPD), respiratory failure and smoking. The outcomes or dependent variables included intraoperative and postoperative events: bronchospasm, hypoxemia, hypercapnia, prolonged intubation and airway secretion. RESULTS: Among these patients (1500 males, 1607 females, mean age 48 years, 1088 ASA I, 1402 ASA II and 617 ASA III), there were 80 congestive heart failures, 82 asthmatics, 122 with COPD, 21 respiratory failures and 428 smokers. Logistic regression analysis showed that female sex (p < 0.001), age over 70 years (p < 0.01), smoking (p < 0.001) and COPD (p < 0.02) significantly influenced pulmonary event development, particularly hypoxemia and bronchospasm, at both times but not in the same patients. Asthma and congestive heart failure cases did not present pulmonary events in the recovery room. CONCLUSION: In upper abdominal surgery under general anesthesia, female sex, age over 70, smoking and COPD were independent risk factors for intra and postoperative pulmonary events.
Chronic idiopathic intestinal pseudo-obstruction treated with jejunostomy: case report and literature review
Authors: Lemos Carlos Renato dos Reis , Popoutchi Pedro , Parra Rogério Serafim , Féres Omar , Rocha José Joaquim Ribeiro da
Published: February 2008

CONTEXT: Chronic idiopathic intestinal pseudo-obstruction is a very rare condition. CASE REPORT: This study describes a male patient who had presented obstructive symptoms for 24 years. He had been treated clinically and had undergone two previous operations in different services, with no clinical improvement or correct diagnosis. He was diagnosed with intestinal obstruction without mechanical factors in our service and underwent jejunostomy, which had a significant decompressive effect. The patient was able to gain weight and presented improvements in laboratory tests. Jejunostomy is a relatively simple surgical procedure that is considered palliative but, in this case, it was resolutive.
Radionuclide imaging of musculoskeletal infection
Authors: Palestro Christopher J. , Love Charito
Published: February 2008

Radionuclide imaging studies are routinely used to evaluate patients suspected of having musculoskeletal infection. Three-phase bone imaging is readily available, relatively inexpensive, and very accurate in the setting of otherwise normal bone. Labeled leukocyte imaging should be used in cases of "complicating osteomyelitis" such as prosthetic joint infection. This test also is useful in clinically unsuspected diabetic pedal osteomyelitis as well as in the neuropathic joint. It is often necessary, however, to perform complementary bone marrow imaging, to maximize the accuracy of labeled leukocyte imaging. In contrast to other regions in the skeleton, labeled leukocyte imaging is not useful for diagnosing spinal osteomyelitis. At the moment, gallium is the preferred radionuclide procedure for this condition and is a useful adjunct to magnetic resonance imaging. FDG-PET likely will play an important role in the evaluation of musculoskeletal infection, especially spinal osteomyelitis, and may replace gallium imaging for this purpose.
Incontinência urinária e a prática de atividades físicas
Authors: Caetano Aletha Silva , Tavares Maria da Consolação Gomes Cunha Fernandes , Lopes Maria Helena Baena de Moraes
Published: February 2008

A incontinência urinária é definida como "toda perda involuntária de urina". Ela atinge com maior freqüência mulheres e é causada principalmente por partos e gestações que podem lesar os músculos responsáveis pela continência na mulher. É muito comum mulheres que praticam atividades físicas e esportes apresentarem incontinência. Muitas dessas mulheres abandonam suas atividades para evitar perder urina durante essa prática, pois essa perda causa vergonha, constrangimento, além de interferir no desempenho durante o exercício. Inexistem pesquisas na área da educação física que discutam esse tema. O objetivo deste estudo consistiu de uma revisão bibliográfica acerca da incontinência urinária, analisando sua relação com atividades físicas e esportivas por mulheres, o impacto causado pela incontinência nessa prática, e de que forma o profissional de educação física pode contribuir com essas mulheres para uma prática mais segura e confortável. Os dados da literatura a respeito desse tema são muito recentes, mas suficientes para evidenciar que a prática de atividades físicas e esportivas constituídas de exercícios que exijam muito esforço e alto impacto pode levar ao desenvolvimento da incontinência urinária. As mulheres que não abandonam suas atividades por causa da incontinência utilizam algumas estratégias para prevenir a perda de urina, como o uso de absorventes e restrição hídrica. O profissional de educação física tem um papel fundamental na orientação adequada de exercícios, transformando essa prática numa intervenção preventiva da incontinência urinária entre mulheres fisicamente ativas.
Avaliação em ambientes virtuais de aprendizagem
Authors: Laguardia Josué , Portela Margareth Crisóstomo , Vasconcellos Miguel Murat
Published: February 2008

A demanda por avaliações de projetos de aprendizagem virtual a distância tem requerido o emprego de conceitos e métodos que transcendem o campo exclusivo da Educação, destacando-se a multiplicidade de marcos teóricos e abordagens técnicas empregados nas estratégias avaliativas de aprendizagem online. A despeito da hegemonia dos métodos quantitativos na avaliação das tecnologias de informação e comunicação, o emprego de métodos qualitativos nas avaliações de ambientes virtuais tem crescido ao longo das duas últimas décadas. A combinação de métodos quali-quantitativos possibilita uma melhor compreensão dos fenômenos subjacentes ao uso das tecnologias para a aprendizagem online. Dado que a educação em ambientes virtuais refere-se a experiências de aprendizagem que utilizam recursos hipermidiáticos em ambientes apoiados por uma tecnologia de comunicação online, optou-se neste artigo enfocar alguns tópicos relativos à avaliação de tecnologias de informação e de aprendizagem nesses ambientes, aprofundando a discussão no que tange aos métodos relevantes à avaliação tanto dos ambientes virtuais de aprendizagem quanto da aprendizagem nesse meio. Essa opção se deve tanto ao reconhecimento das especificidades das práticas pedagógicas da EaD que colocam em evidência a relação entre educação e comunicação, viabilizadas por meio das tecnologias de informação e comunicação, quanto aos diversos papéis, negativos e positivos, atribuídos às tecnologias de comunicação e informação na Educação.
Vitamin K‐Independent Warfarin Resistance After Concurrent Administration of Warfarin and Continuous Enteral Nutrition
Authors: Dickerson Roland N. , Garmon Wesley M. , Kuhl David A. , Minard Gayle , Brown Rex O.
Published: February 2008

Study Objective. To assess the influence of withholding continuous enteral nutrition for 1 hour before and after warfarin administration compared with the coadministration of warfarin with continuous enteral nutrition on changes in international normalized ratios (INRs).

Design. Retrospective, crossover case series.

Setting. Intensive care units of a university‐affiliated medical center.

Patients. Six adults who required nutritional support for at least the first 10 consecutive days of warfarin therapy; during that 10‐day period, they had a period of at least 3 consecutive days during which the enteral feeding was withheld for 1 hour before and after warfarin administration, and had a period of at least 3 consecutive days when feedings were not withheld during warfarin administration. Patients with advanced liver disease and those who received therapies, during the observation period, that significantly alter warfarin metabolism were omitted from the study.

Measurements and Main Results. The change in INR during the 3‐day observation period when feedings were withheld for 1 hour before and after warfarin administration was significantly different versus the change in INR during coadministration of warfarin with continuous feeding (mean ± SD 0.74 ± 0.66 vs −0.13 ± 0.81, p<0.05). This difference in INR response occurred despite the administration of similar dosages of warfarin (5.6 ± 2.1 vs 5.7 ± 2.1 mg/day, p>0.05). Also noted was a clinically irrelevant, but statistically significant, difference in vitamin K intake between treatment periods (77 ± 36 μg/day when feedings were withheld vs 102 ± 28 μg/day when feedings were not withheld, p≥0.05).

Conclusion. Continuous enteral nutrition should be withheld for 1 hour before and after warfarin administration to prevent enteral nutrition‐associated warfarin resistance.
Lipid‐Lowering Efficacy and Safety After Switching to Atazanavir‐Ritonavir‐Based Highly Active Antiretroviral Therapy in Patients with Human Immunodeficiency Virus
Authors: Nguyen Sean T. , Eaton Susan A. , Bain Amy M. , Rahman Anita P. , Payne Kenna D. , Bedimo Roger , Herrington Jon D. , Maclayton Darego O. , Rodriguez‐Barradas Maria C. , Busti Anthony J.
Published: February 2008

Study Objective. To evaluate the efficacy, safety, and lipid‐lowering effects after switching from a non‐atazanavir‐containing, protease inhibitor‐based highly active antiretroviral therapy (HAART) to atazanavir‐ritonavir‐based HAART in patients infected with human immunodeficiency virus (HIV).

Design. Multicenter, noncontrolled, retrospective study.

Setting. Three tertiary teaching hospitals.

Patients. Thirty‐six patients with HIV infection, aged 18 years or older, who were receiving non‐atazanavir‐containing, protease inhibitor‐based HAART that was switched to atazanavir 300 mg‐ritonavir 100 mg‐based HAART without changes in nucleoside reverse transcriptase inhibitors and confounders known to alter serum lipid levels.

Measurements and Main Results. Lipid profiles measured 4 weeks‐6 months before the switch, as well as follow‐up lipid profiles measured 4 weeks‐6 months after receiving the new HAART regimen, were evaluated. The switch resulted in the following changes in lipid levels: total cholesterol−9% (p=0.002), low‐density lipoprotein cholesterol−13% (p<0.001), high‐density lipoprotein cholesterol (HDL)−2% (p=0.431), triglycerides−23% (p=0.007), non‐HDL−11% (p=0.002), total cholesterol:HDL ratio−10% (p=0.004), and triglyceride:HDL ratio−24% (p=0.019). A subgroup analysis was conducted on the lipid profiles of nine patients who still met the strict inclusion and exclusion criteria up to 9 months after the switch; it showed that the reductions in their lipid profiles were sustained. In addition, 33% more patients achieved their National Cholesterol Education Panel (NCEP) Adult Treatment Panel (ATP) III cholesterol goals. No significant changes were noted in median (interquartile range) CD4+ counts (372 [236–551] and 361 [217–464] cells/mm3, p=0.118) or in number of patients with undetectable HIV viral loads ([defined as < 50 copies/ml] 32/36 and 31/36 patients, p>0.05) between baseline and after the switch, respectively.

Conclusion. Switching to an atazanavir‐ritonavir‐based HAART regimen was associated with significant improvement in lipid profiles, similar to those seen in clinical trials, without compromising safety or viral and immunologic control. In addition, more patients were able to achieve their NCEP ATP III goals.
Temozolomide‐Induced Desquamative Skin Rash in a Patient with Metastatic Melanoma
Authors: Pick Amy M. , Neff William J. , Nystrom Kelly K.
Published: February 2008

Temozolomide is an oral alkylating agent used in the treatment of metastatic melanoma. Commonly reported adverse effects of the drug include nausea and vomiting, constipation, headache, and fatigue, as well as myelosuppression, which may be dose limiting. Few reports have described dermatologic adverse effects such as rash and pruritus, and, to our knowledge, none have discussed the seriousness or extensiveness of the rash. We describe a 37‐year‐old woman who was receiving temozolomide for treatment of metastatic melanoma. After 6 weeks of therapy, the patient developed an unexplained fever. The drug was discontinued, and the fever resolved within 2 days. Temozolomide was restarted 2 months later; the patient again developed a fever. This time the fever was accompanied by a diffuse erythematous skin rash that progressed to an extensive, full‐body, desquamative skin rash. The rash was treated with moisturizing cream along with intravenous and topical corticosteroids and antibiotics. Due to the severity of the rash, temozolomide was permanently discontinued. Even after its discontinuation, the patient experienced the rash on a long‐term basis, with periodic exacerbations. However, none were as severe as the first rash. The patient's metastatic disease remained stable for the next 2 years. According to the Naranjo adverse drug reaction probability scale, the likelihood that temozolomide was responsible for the adverse drug reaction of fever was probable (score of 6). Clinicians should be aware that an erythematous and exfoliative rash may be induced by temozolomide, and be familiar with the pharmacologic and supportive measures necessary for its treatment.
Situated Identities: Power and Positioning in the Work of a Literacy Coach
Authors: Rainville Kristin N. , Jones Stephanie
Published: February 2008

A literacy coach's work is about far more than a knowledge base in how teaching and learning works in literacy classrooms. It is also about deep understandings of situational enactments and how one's position will impact what happens in a particular context. This article has significant implications for the preparation and ongoing professional development opportunities for literacy coaches that includes work around issues of power and positioning and begins to support coaches in learning to “read” situations to help them to be responsive in the way they position themselves.
CPMs: A Kinesthetic Comprehension Strategy
Authors: Block Cathy Collins , Parris Sheri R. , Whiteley Cinnamon S.
Published: February 2008

This article discusses a study to determine whether primary grade students can learn comprehension processes via hand motions to portray these mental processes. Comprehension Process Motions (CPMs) were designed to provide students with a way to make abstract comprehension processes more consciously accessible and also to give teachers a way to observe what students have (or have not) comprehended. Results were based on a 12‐week study of 257 experimental and 256 control students in grades K–5. Comprehension scores on standardized, criterion‐referenced, and norm‐referenced tests were significantly higher for experimental students than for those who were not exposed to CPM instruction. These data provide evidence that even the youngest readers are capable of internalizing comprehension processes and knowing how to elicit them at specific points in a text when they are needed.
London Underground bridge slide at White City viaduct, UK
Authors: Karbassi A. , Knight P. , Sharrocks D.
Published: February 2008

At White City in west London, the Hammersmith and City line runs on a high-level brick arch viaduct that crosses over both Wood Lane and the eastbound Central line. As part of the White City development, a section of this viaduct was removed and replaced with a new twin-track highly skewed bridge. This comprised a half-through bridge formed from three principal steel girders with connecting cross-beams and concrete infill. The deck was built off line, then slid into position during a four-day possession of the Hammersmith and City line, requiring part of the existing viaduct to be demolished; the Central line below remained open throughout. The piled substructure was constructed within the constraints of the existing viaduct arches. The existing early 1930s steel bridge deck over Wood Lane was strengthened in advance to provide new bearing positions. During the possession it was truncated by 2 m and supported on new piers.
Analysis of compressive membrane action in concrete slabs
Authors: Zheng Y. , Robinson D. , Taylor S. , Cleland D. , Shaat A.
Published: February 2008

This paper summarises the results obtained from non-linear finite-element analysis (NLFEA) of a series of reinforced-concrete one-way slabs with various boundary conditions representative of a bridge deck slab strip in which compressive membrane action governs the structural behaviour. The application of NLFEA for the optimum analysis and design of in-plane restrained concrete slabs is explored. An accurate material model and various equation solution methods were assessed to find a suitable finite-element method for the analysis of concrete slabs in which arching action occurs. Finally, the results from the NLFEA are compared and validated with those from various experimental test data. Significantly, the numerical analysis was able to model the arching action that occurred as a result of external in-plane restraint at the supports and which enhanced the ultimate strength of the slab. The NLFEA gave excellent predictions for the ultimate load-carrying capacity and far more accurate predictions than those obtained using standard flexural or elastic theory.
Design, Execution, and Evaluation of Frac and Pack (F&P) Treatments in Unconsolidated Sand Formations in the Gulf of Mexico
Authors: Wong G. K. , Fors R. R. , Casassa J. S. , Hite R. H. , Shlyapobersky Jacob
Published: February 2008

This paper presents a skin analysis of Frac and Pack (F&P) completions and summarizes our F&P design methodology, field execution procedures, and productivity responses for ten F&P jobs done in a wide range of field conditions in the Gulf of Mexico (GOM). The purpose of the paper is to identify design and job execution requirements to better optimize F&P treatments.

The skin analysis revealed that near-wellbore skins, from perforation tunnels (casing and cement sheath) and a choked fracture, can dominate the final F&P completion skin. Near-wellbore skins are particularly damaging when F&P treatments have low dimensionless fracture conductivity ratios (FCD) and when perforation tunnels are not filled with permeable proppant. Therefore, F&P designs should aim for high fracture conductivities with FCD greater than one and fill perforation tunnels with proppant permeability greater than 200 times the formation permeability. For most applications in GOM, such requirements require larger proppant sizes that may not satisfy gravel packing requirements.

Besides maximizing the FCD, the perforating completion and the execution of F&P should include steps to minimize near-wellbore damage. These include perforating with high shot density and big hole charges, initiating or breaking down the fracture with high pump rate, packing the fracture (near the wellbore) with high concentration loading of sand, implementing fluid quality control, and providing sufficient breakers for the fracturing fluid.
Frac and Pack Stimulation: Application, Design, and Field Experience From the Gulf of Mexico to Borneo
Authors: Roodhart L. P. , Fokker P. A. , Davies D. R. , Shlyapobersky Jacob , Wong G. K.
Published: February 2008

A relatively short, highly conductive fracture created in a reservoir of moderate to high permeability will breach near-wellbore damage, reduce the drawdown, near-wellbore flow velocity and stresses and increase the effective wellbore radius. Fracturing treatments in such reservoirs consist of two stages: 1) fracture creation, terminated by tip screen-out, and 2) fracture inflation and packing. Such a two-stage treatment is the basis of a number of new well completion methods, known as "Frac & Pack". This technique has been successfully applied for a range of fracture sizes in various reservoirs in many parts of the globe.

The selection criteria for wells to be Frac & Packed are discussed. It is shown how an inflow-performance simulator can be used for assessing the potential of Frac & Packed wells, to identify the controlling factors and to optimize design parameters. It is shown that fracture conductivity is often the key to successful treatment. This conductivity is largely dependent on proppant size; formation permeability damage around the created fracture has less effect. The application of the overpressure-calibrated hydraulic fracture model in the design of Frac & Pack treatments and some operational considerations are illustrated with reference to field examples.

The full potential of this promising new completion method will only be achieved if the design is tailored to the individual well. This demands high-quality input data that can only be obtained from a calibration test.

This paper presents the strategy we have worked out for Frac & Pack design, with illustrations from field experience. Several areas which need to be addressed by the industry, such as proppant sizing in soft formations and fluid-resin interaction during use of resin-coated proppant, are identified.
Joint Hydrological–Geophysical Inversion for Soil Structure Identification
Authors: Finsterle Stefan , Kowalsky Michael B.
Published: February 2008

Reliable prediction of subsurface flow and contaminant transport depends on the accuracy with which the values and spatial distribution of process‐relevant model parameters can be identified. Successful characterization methods for complex soil systems are based on (i) an adequate parameterization of the subsurface, capable of capturing both random and structured aspects of the heterogeneous system, and (ii) site‐specific data that are sufficiently sensitive to the processes of interest. We present a stochastic approach in which the high‐resolution imaging capability of geophysical methods is combined with the process‐specific information obtained from the inversion of hydrological data. Geostatistical concepts are employed as a flexible means to describe and characterize subsurface structures. The key features of the proposed approach are (i) the joint inversion of geophysical and hydrological raw data, avoiding the intermediate step of creating a (nonunique and potentially biased) tomogram of geophysical properties and (ii) the concurrent estimation of hydrological and petrophysical parameters, in addition to (iii) the determination of geostatistical parameters from the joint inversion of hydrological and geophysical data. This approach is fundamentally different from inference of geostatistical parameters from an analysis of spatially distributed property data. The approach has been implemented into the iTOUGH2 inversion code and is demonstrated for the joint use of synthetic time‐lapse ground penetrating radar (GPR) travel times and hydrological data collected during a simulated ponded infiltration experiment at a highly heterogeneous site.
Modeling Hydraulic Responses to Meteorological Forcing: From Canopy to Aquifer
Authors: Pan Lehua , Jin Jiming , Miller Norman , Wu Yu‐Shu , Bodvarsson Gudmundur
Published: February 2008

An understanding of the hydrologic interactions among atmosphere, land surface, and subsurface is one of the keys to understanding the water cycling system that supports our life system on earth. Properly modeling such interactions is a difficult task because of the inherent coupled processes and complex feedback structures among subsystems. In this paper, we present a model that simulates the land‐surface and subsurface hydrologic response to meteorological forcing. This model combines a state‐of‐the‐art land‐surface model, the National Center for Atmospheric Research (NCAR) Community Land Model version 3 (CLM3), with a variably saturated groundwater model, TOUGH2, through an internal interface that includes flux and state variables shared by the two submodels. Specifically, TOUGH2 in its simulation uses infiltration, evaporation, and root‐uptake rates, calculated by CLM3, as source–sink terms; CLM3 in its simulation uses saturation and capillary pressure profiles, calculated by TOUGH2, as state variables. This new model, CLMT2, preserves the best aspects of both submodels: the state‐of‐the‐art modeling capability of surface energy and hydrologic processes from CLM3 and the more realistic physical process–based modeling capability of subsurface hydrologic processes from TOUGH2. The preliminary simulation results show that the coupled model greatly improves the predictions of the water table, evapotranspiration, surface temperature, and moisture in the top 20 cm of soil at a real watershed, as evaluated from 18 yr of observed data. The new model is also ready to be coupled with an atmospheric simulation model, representing one of the first models capable of simulating hydraulic processes from the top of the atmosphere to deep ground.
Numerical Simulation of Field‐Scale Contaminant Mass Transfer during Air Sparging
Authors: VanAntwerp Darby J. , Falta Ronald W. , Gierke John S.
Published: February 2008

Air sparging is a remediation technology for removing volatile organic contaminants (VOCs) from below the water table using air injection. Contaminant mass removal can be controlled by the mass transfer between liquid phases (aqueous and nonaqueous phase liquid [NAPL]) and the injected gas phase. Traditional multiphase flow numerical models ignore subgridblock‐scale effects of gas channel flow on local mass transfer and assume local equilibrium between liquid and gas phases. This traditional, single‐domain modeling approach tends to overpredict contaminant mass removal during sparging. A dual‐domain multiphase flow approach for local interphase mass transfer may more accurately simulate contaminant removal, while still accounting for injected gas plume behavior. Mass transfer limitations are introduced through a numerical grid modification where each traditional single‐domain gridblock is split into two domains: one with very strong capillary pressures that remains mostly water saturated and one with weak capillary pressures that becomes mostly gas saturated during sparging. The two domains are coupled through a first‐order mass transfer expression. This simple model can then approximate the localized (subgridblock‐scale) gas channel effects on mass transfer that are limited by liquid phase diffusion. In this study, data from a two‐dimensional laboratory‐scale experiment and a field‐scale air sparging demonstration were used to test the capabilities of the dual‐ and single‐domain approaches. It is the first time mass transfer has been simulated for air sparging at either of these scales using a multiphase flow kinetic interphase mass transfer model. Both experiments involved air sparging remediation of tetrachloroethylene, a NAPL. The single‐domain local‐equilibrium model resulted in an overprediction of mass removal rates in both cases. The dual‐domain mass transfer approach provided a much better fit of the experimental data, and it is shown that the apparent interphase mass transfer coefficient becomes smaller with increasing scale.
GPR Attenuation and Scattering in a Mature Hydrocarbon Spill: A Modeling Study
Authors: Cassidy Nigel J.
Published: February 2008

Subsurface contamination by light nonaqueous‐phase liquids (LNAPLs) is a pressing environmental issue with many industrial sites having some degree of near‐surface pollution. Noninvasive, geophysical investigation methods, such as ground penetrating radar (GPR), have become increasingly popular, but their use has tended to be restricted to plume “mapping” and recent contamination events only. Mature LNAPL contamination, where the hydrocarbons undergo significant alteration and biodegradation, complicates the electrophysical properties of the subsurface, making GPR data interpretation more difficult. This is particularly true in shallow, coastal environments where LNAPLs form a disaggregated, smeared zone associated with the seasonally changing groundwaters. Therefore, any method that can improve data interpretation has a significant practical benefit in these complex environments. By using dielectric material property analysis, empirical mixing model evaluation, and three‐dimensional, finite‐difference time‐domain (FDTD) modeling, it has been possible to investigate the nature and spectral content of GPR signal attenuation and scattering within the vadose or smeared zone of a mature LNAPL‐contaminated site. Using FDTD models to simulate real subsurface conditions, a comparison between the GPR response of “clean” and contaminated environments has been made where the subsurface materials contain different LNAPL–porewater saturations and contaminant geometries. The results show that uniform mixtures, disaggregated scattering mixtures, and stratified pools of contaminated material all exhibit different, yet characterizable, temporal and spectral GPR responses and that the recorded data can provide new insights into the mode of contaminant distribution and saturation as long as the incident field of the GPR system can be determined accurately.
Measuring Water Content Heterogeneity Using Multifold GPR with Reflection Tomography
Authors: Bradford John H.
Published: February 2008

Continuous multioffset acquisition of ground penetrating radar (GPR) data provides the capability to measure the lateral and vertical distribution of soil moisture. Multioffset data enable measurement of radar velocity, which in turn allows the estimation of soil moisture through an appropriate petrophysical relationship. Although rarely used in GPR investigations, reflection tomography coupled with prestack depth migration has the ability to measure lateral velocity variations with much greater resolution and accuracy than conventional methods of velocity analysis. I used reflection tomography in the post‐migration domain to estimate radar velocity and the Topp equation to estimate subsurface moisture distribution in two and three dimensions. At a contaminated site near a former refinery I identified a near‐vertical boundary separating coarse‐grained sands and gravels from a unit containing a high fraction of silts and clays. At a chlorinated solvent waste site, I found significant heterogeneity in the moisture content distribution despite apparent homogeneity indicated by direct push methods.
Assessment of Chlamydia trachomatis, Ureaplasma urealyticum, Ureaplasma parvum, Mycoplasma hominis, and Mycoplasma genitalium in Semen and First Void Urine Specimens of Asymptomatic Male Partners of Infertile Couples
Authors: Gdoura R. , Kchaou W. , Ammar‐Keskes L. , Chakroun N. , Sellemi A. , Znazen A. , Rebai T. , Hammami A.
Published: February 2008

ABSTRACT: The purpose of this study was threefold: to compare semen and first void urine (FVU) specimens from asymptomatic infertile men for the detection of Chlamydia trachomatis, genital ureaplasma, and genital mycoplasma infections using in‐house inhibitor‐controlled polymerase chain reaction (PCR)–microtiter plate hybridization assay; to determine the prevalence of those organisms in infertile men in Tunisia; and to study the relationship between these bacteria and male infertility. Paired urine and semen specimens from 104 patients were examined by in‐house PCR for the presence of DNA of Chlamydia trachomatis, genital ureaplasmas (Ureaplasma urealyticum and Ureaplasma parvum) and genital mycoplasmas (Mycoplasma hominis and Mycoplasma genitalium). Semen analysis was assessed according to the guidelines of the World Health Organization. Nominal scale variables, the Mann‐Whitney test, and the Kruskal‐Wallis nonparametric analysis of variance test were used for statistical analysis. There was a very high concordance (>95%) and a very good agreement (κ > 0.9) between the detection of Chlamydia trachomatis, genital ureaplasmas, and Mycoplasma hominis in semen and corresponding FVU specimens. Our findings also show a high concordance (81.1%) and a good agreement (κ = 0.79) between the detection of Mycoplasma genitalium in both specimens. C trachomatis, genital mycoplasmas, and genital ureaplasmas were found to be widespread among infertile male patients in Tunisia, as shown by their respective prevalences of 43.3%, 18.3%, and 14.4%. The mean values of seminal volume, sperm concentration, sperm viability, sperm motility, sperm morphology, and leukocyte count were not significantly related either to the detection of C trachomatis DNA or to that of genital ureaplasma or mycoplasma DNA in semen specimens. Using our in‐house PCR, both semen and FVU were found to be sensitive diagnostic specimens for the detection of C trachomatis, ureaplasmas, and mycoplasmas. The FVU, a less invasive and self‐collected specimen, can serve as a marker for the presence of these organisms in the genital tract and can be used as a reliable way of detecting asymptomatic carriers of infection.
LED vs Halogen Light-Curing of Adhesive-Precoated Brackets
Authors: Mirabella Davide , Spena Raffaele , Scognamiglio Giovanni , Luca Lombardo , Gracco Antonio , Siciliani Giuseppe
Published: February 2008

Objective: To test the hypothesis that bonding with a blue light-emitting diode (LED) curing unit produces no more failures in adhesive-precoated (APC) orthodontic brackets than bonding carried out by a conventional halogen lamp.

Materials and Methods: Sixty-five patients were selected for this randomized clinical trial, in which a total of 1152 stainless steel APC brackets were employed. In order to carry out a valid comparison of the bracket failure rate following use of each type of curing unit, each patient's mouth was divided into four quadrants. In 34 of the randomly selected patients, designated group A, the APC brackets of the right maxillary and left mandibular quadrants were bonded using a halogen light, while the remaining quadrants were treated with an LED curing unit. In the other 31 patients, designated group B, halogen light was used to cure the left maxillary and right mandibular quadrants, whereas the APC brackets in the remaining quadrants were bonded using an LED dental curing light. The bonding date, the type of light used for curing, and the date of any bracket failures over a mean period of 8.9 months were recorded for each bracket and, subsequently, the chi-square test, the Yates-corrected chi-square test, the Fisher exact test, Kaplan-Meier survival estimates, and the log-rank test were employed in statistical analyses of the results.

Results: No statistically significant difference in bond failure rate was found between APC brackets bonded with the halogen light-curing unit and those cured with LED light. However, significantly fewer bonding failures were noted in the maxillary arch (1.67%) than in the mandibular arch (4.35%) after each light-curing technique.

Conclusions: The hypothesis cannot be rejected since use of an LED curing unit produces similar APC bracket failure rates to use of conventional halogen light, with the advantage of a far shorter curing time (10 seconds).
Cone Beam Computed Tomography 3D Reconstruction of the Mandibular Condyle
Authors: Schlueter Brian , Kim Ki Beom , Oliver Donald , Sortiropoulos Gus
Published: February 2008

Objective: To determine the ideal window level and width needed for cone beam computed three-dimensional (3D) reconstruction of the condyle.

Materials and Methods: Linear dimensions were measured with a digital caliper to assess the anatomic truth for 50 dry human mandibular condyles. Condyles were scanned with the i-CAT cone beam computed tomography (CBCT) and 3D-models were reconstructed. Three linear three-dimensional measurements were made on each of the 50 condyles at 8 different Hounsfield unit (HU) windows. These measurements were compared with the anatomic truth. Volumetric measurements were also completed on all 50 condyles, at 23 different window levels, to define the volumetric distribution of bone mineral density (BMD) within the condyle.

Results: Significant differences were found in two of the three linear measurement groups at and below the recommended viewing window for osseous structures. The most accurate measurements were made within the soft tissue range for HU window levels. Volumetric distribution measurements revealed that the condyles were mostly comprised of low-density bone, and that condyles exhibiting significant changes in linear measurements were shown to have higher percentages of low-density bone than those condyles with little change from the anatomic truth.

Conclusions: CBCT assessment of the mandibular condyle, using the 3D reconstruction, is most accurate when accomplished at density levels below that recommended for osseous examination. However, utilizing lower window levels which extend into the soft tissue range, may compromise one's capacity to view the bony topography.
Healing of Periodontal Tissues Following Transplantation of Cells in a Rat Orthodontic Tooth Movement Model
Authors: Nayak Bob N. , Wiltshire William A. , Ganss Ben , Tenenbaum Howard , McCulloch Christopher A. G. , Lekic Charles
Published: February 2008

Objective: To determine the fate and differentiation of transplanted periodontal ligament (PL) precursor cells and mouse embryonic stem (ES) cells and their relative capacity to regenerate wounded periodontium.

Materials and Methods: Orthodontic tooth movement was introduced 24 hours before transplantation of PL or ES cells, and rats were euthanized either 24 hours or 72 hours after cell transplantation. The control rats received either no tooth movement and no cell transplantation or tooth movement and no cell transplantation. Differentiation of transplanted cells was assessed from mandibular periodontal histological tissue sections by immunohistochemical methods using monoclonal antibodies against PL cell differentiation markers. Data were analyzed using Student's t-test at a significance level of P = .05.

Results: Transplantation of PL and ES cells resulted in a higher number of osteopontin, bone sialoprotein, and α-smooth muscle actin labeled transplanted cells, predominantly around the blood vessels of the periodontium in study rats compared with control rats (cell transplantation but no orthodontic tooth movement, P = .05). Combined treatments of tooth movement and cell transplantation resulted in enhanced regeneration of the periodontium as a result of tooth movement. Transplantation of PL cells induced a higher number of differentiating cells in the PL and alveolar bone than did transplantation of ES cells.

Conclusions: Orthodontic tooth movement promotes the differentiation of transplanted cells, and the differentiation occurs predominantly in the paravascular areas of the periodontium. In terms of regeneration of wounded periodontium, transplantation of PL cells produced a higher level of regeneration than ES cells, possibly because of PL cell plasticity and the capacity to undergo effective differentiation in the periodontal cellular microenvironment.
Effects of Short- and Long-Term Celecoxib on Orthodontic Tooth Movement
Authors: Hauber Gameiro Gustavo , Nouer Darcy Flávio , Pereira Neto João Sarmento , Siqueira Vânia Célia , Andrade Eduardo Dias , Duarte Novaes Pedro , Veiga Maria Cecília Ferraz
Published: February 2008

Objective: To test the hypothesis that short- and long-term celecoxib administration has no effect on orthodontic tooth movement.

Materials and Methods: Male Wistar rats were submitted to short- (3 days) and long-term (14 days) celecoxib administration, while the respective control groups received equivolumetric saline intraperitoneal injections. The upper left first molars of all rats were moved mesially for 14 days by a fixed orthodontic appliance exerting 50 g force upon insertion. After the experimental period, tooth movement was quantified and tissues around the first molar were processed for tartrate-resistant acid phosphatase (TRAP) histochemistry. The amount of tooth movement and the number of TRAP-positive cells on the alveolar bone surface were evaluated.

Results: The amount of tooth movement was significantly reduced in rats submitted to short- and long-term celecoxib administration, while the number of osteoclasts on the alveolar bone did not differ between the four groups studied.

Conclusions: The hypothesis is rejected. Although celecoxib administration did not affect the number of osteoclasts, the osteoclast activity might be reduced, which could explain the inhibition of tooth movement observed in the celecoxib-treated animals. These results indicate that orthodontists should be aware of patients under short- and long-term therapy with celecoxib.
Effect of LDL Cholesterol and Treatment With Losartan on End-Stage Renal Disease in the RENAAL Study
Authors: Tershakovec Andrew M. , Keane William F. , Zhang Zhongxin , Lyle Paulette A. , Appel Gerald B. , McGill Janet B. , Parving Hans-Henrik , Cooper Mark E. , Shahinfar Shahnaz , Brenner Barry M.
Published: February 2008

Renal pathology and dyslipidemia commonly coexist. Treatments that lower albuminuria/proteinuria may lower lipids, but it is not known whether lipid lowering independent of lessening albuminuria/proteinuria slows progression of kidney disease. We examined the association between LDL cholesterol levels and treatment with losartan on end-stage renal disease (ESRD). Lipid levels and albuminuria measurements were obtained at baseline and at year 1 in a post hoc analysis from the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) study, which compared the effects of losartan- versus placebo-based antihypertensive therapy in patients with type 2 diabetes and nephropathy. LDL cholesterol lowering was associated with a lower risk of ESRD; however, this seemed to be largely an association with the reduction in albuminuria.
Relationship of Glycemic Control, Exogenous Insulin, and C-Peptide Levels to Ischemic Heart Disease Mortality Over a 16-Year Period in People With Older-Onset Diabetes
Authors: Hirai Flavio E. , Moss Scot E. , Klein Barbara E.K. , Klein Ronald
Published: February 2008

OBJECTIVE—The purpose of this study was to examine the relationship of glycemic control and exogenous and endogenous insulin levels with all-cause and cause-specific mortality (ischemic heart disease and stroke) in an older-onset diabetic population.

RESEARCH DESIGN AND METHODS—The Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) is an ongoing, prospective, population-based cohort study of individuals with diabetes first examined in 1980–1982. A stratified sample of all individuals with diabetes diagnosed at 30 years of age or older was labeled “older-onset” (n = 1,370). Those participating in the 1984–1986 examination phase (n = 1,007) were included in the analysis. Endogenous insulin was determined by measurements of plasma C-peptide (in nanomoles per liter), and exogenous insulin was calculated in units per kilogram per day. Glycemic control was determined by levels of glycosylated hemoglobin (HbA1).

RESULTS—After 16 years of follow-up, 824 individuals died (all-cause mortality); 358 deaths involved ischemic heart disease and 137 involved stroke. C-peptide and HbA1 were significantly associated with all-cause and ischemic heart disease mortality in our study. The hazard ratio (95% CI) values for all-cause mortality were 1.12 (1.07–1.17) per 1% increase in HbA1, 1.20 (0.85–1.69) per 1 unit · kg−1 · day−1 increase in exogenous insulin, and 1.15 (1.04–1.29) per 1 nmol/l increase in C-peptide and for ischemic heart disease mortality were 1.14 (1.06–1.22), 1.50 (0.92–2.46), and 1.19 (1.02–1.39) for HbA1, exogenous insulin, and C-peptide, respectively, after adjusting for relevant confounders. C-peptide was associated with stroke mortality only among men (1.65 [1.07–2.53]).

CONCLUSIONS—Our results show that individuals with higher endogenous insulin levels are at higher risk of all-cause, ischemic heart disease, and stroke mortality.
A Risk Score for Type 1 Diabetes Derived From Autoantibody-Positive Participants in the Diabetes Prevention Trial–Type 1
Authors: Sosenko Jay M. , Krischer Jeffrey P. , Palmer Jerry P. , Mahon Jeffrey , Cowie Catherine , Greenbaum Carla J. , Cuthbertson David , Lachin John M. , Skyler Jay S. ,   the Diabetes Prevention Trial–Type 1 Study Group
Published: February 2008

OBJECTIVE—The accurate prediction of type 1 diabetes is essential for appropriately identifying prevention trial participants. Thus, we have developed a risk score for the prediction of type 1 diabetes.

RESEARCH DESIGN AND METHODS—Diabetes Prevention Trial–Type 1 (DPT-1) participants, islet cell autoantibody (ICA)-positive relatives of type 1 diabetic patients (n = 670), were randomly divided into development and validation samples. Risk score values were calculated for the validation sample from development sample model coefficients obtained through forward stepwise proportional hazards regression.

RESULTS—A risk score based on a model including log-BMI, age, log-fasting C-peptide, and postchallenge glucose and C-peptide sums from 2-h oral glucose tolerance tests (OGTTs) was derived from the development sample. The baseline risk score strongly predicted type 1 diabetes in the validation sample (χ2 = 82.3, P < 0.001). Its strength of prediction was almost the same (χ2 = 83.3) as a risk score additionally dependent on a decreased first-phase insulin response variable from intravenous glucose tolerance tests (IVGTTs). Biochemical autoantibodies did not contribute significantly to the risk score model. A final type 1 diabetes risk score was then derived from all participants with the same variables as those in the development sample model. The change in the type 1 diabetes risk score from baseline to 1 year was in itself also highly predictive of type 1 diabetes (P < 0.001).

CONCLUSIONS—A risk score based on age, BMI, and OGTT indexes, without dependence on IVGTTs or additional autoantibodies, appears to accurately predict type 1 diabetes in ICA-positive relatives.