bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcomes of Active Surveillance for Men With Intermediate-Risk Prostate Cancer
Authors: Cooperberg Matthew R. , Cowan Janet E. , Hilton Joan F. , Reese Adam C. , Zaid Harras B. , Porten Sima P. , Shinohara Katsuto , Meng Maxwell V. , Greene Kirsten L. , Carroll Peter R.
Published: November 2010

Purpose

Active surveillance (AS) is an option for the initial management of early-stage prostate cancer. Current risk stratification schema identify patients with low-risk disease who are presumed to be most suitable for AS. However, some men with higher risk disease also elect AS; outcomes for such men have not been widely reported.

Patients and Methods

Men managed with AS at University of California, San Francisco, were classified as low- or intermediate-risk based on serum prostate-specific antigen (PSA), Gleason grade, extent of biopsy involvement, and T stage. Clinical and demographic characteristics, and progression in terms of Gleason score, PSA kinetics, and active treatment were compared between men with low- and intermediate-risk tumors.

Results

Compared to men with low-risk tumors, those with intermediate-risk tumors were older (mean, 64.9 v 62.3 years) with higher mean PSA values (10.9 v 5.1 ng/mL), and more tumor involvement (mean, 20.4% v 15.3% positive biopsy cores; all P < .01). Within 4 years of the first positive biopsy, the clinical risk group did not differ in terms of the proportions experiencing progression-free survival, (low [54%] v intermediate [61%]; log-rank P = .22) or the proportions who underwent active treatment (low [30%] v intermediate [35%]; log-rank P = .88). Among men undergoing surgery, none were node positive and none had biochemical recurrence within 3 years.

Conclusion

Selected men with intermediate-risk features be appropriate candidates for AS, and are not necessarily more likely to progress. AS for these men may provide an opportunity to further reduce overtreatment of disease that is unlikely to progress to advanced cancer.
Regulation of male germ cell cycle arrest and differentiation by DND1 is modulated by genetic background
Authors: Cook Matthew S. , Munger Steven C. , Nadeau Joseph H. , Capel Blanche
Published: November 2010

Human germ cell tumors show a strong sensitivity to genetic background similar to Dnd1Ter/Ter mutant mice, where testicular teratomas arise only on the 129/SvJ genetic background. The introduction of the Bax mutation onto mixed background Dnd1Ter/Ter mutants, where teratomas do not typically develop, resulted in a high incidence of teratomas. However, when Dnd1Ter/Ter; Bax–/– double mutants were backcrossed to C57BL/6J, no tumors arose. Dnd1Ter/Ter germ cells show a strong downregulation of male differentiation genes including Nanos2. In susceptible strains, where teratomas initiate around E15.5-E17.5, many mutant germ cells fail to enter mitotic arrest in G0 and do not downregulate the pluripotency markers NANOG, SOX2 and OCT4. We show that DND1 directly binds a group of transcripts that encode negative regulators of the cell cycle, including p27Kip1 and p21Cip1. P27Kip1 and P21Cip1 protein are both significantly decreased in Dnd1Ter/Ter germ cells on all strain backgrounds tested, strongly suggesting that DND1 regulates mitotic arrest in male germ cells through translational regulation of cell cycle genes. Nonetheless, in C57BL/6J mutants, germ cells arrest prior to M-phase of the cell cycle and downregulate NANOG, SOX2 and OCT4. Consistent with their ability to rescue cell cycle arrest, C57BL/6J germ cells overexpress negative regulators of the cell cycle relative to 129/SvJ. This work suggests that reprogramming of pluripotency in germ cells and prevention of tumor formation requires cell cycle arrest, and that differences in the balance of cell cycle regulators between 129/SvJ and C57BL/6 might underlie differences in tumor susceptibility.
Developmental and biomechanical considerations in the provision of wrist orthoses in children with obstetrical brachial plexus palsy
Authors: Ho Emily S
Published: November 2010

Introduction

Children with obstetrical brachial plexus palsy may have motor deficits in wrist extension that impact optimal hand function. Wrist orthoses are recommended for such impairment to address biomechanical and functional needs. The functional need of the child should be considered within the context of their developmental expectation.

Methods

A review of the literature pertaining to brachial plexus, wrist joint and injuries, orthotics devices and splints in children was conducted. The databases MEDLINE, AMED (Allied and Complementary Medicine) and CINAHL (Cumulative Index to Nursing and Allied Health Literature) were searched from 1950, 1985 and 1981, respectively, to July 2009 using the Medical Subject Headings (MeSH) brachial plexus, wrist joint and injuries, orthotics devices and splints under the limits of children aged 0–18 years.

Results

There is a paucity of literature on the orthotic management for this impairment. Therefore, an evaluation of the literature on development and the biomechanics of the wrist joint is necessary to develop clinical guidelines for the provision of wrist orthoses in children with obstetrical brachial plexus palsy. An algorithm for providing wrist orthoses in this population is proposed.

Discussion

A balance between biomechanical risks and functional needs at each developmental stage is needed to optimize hand function in the prescription of wrist orthoses.
Identification of an RNase J ortholog in Sulfolobus solfataricus: Implications for 5′-to-3′ directional decay and 5′-end protection of mRNA in Crenarchaeota
Authors: Hasenöhrl David , Konrat Robert , Bläsi Udo
Published: November 2010

In both Bacteria and Eukaryotes, degradation is known to start at the 5′ and at the 3′ extremities of mRNAs. Until the recent discovery of 5′-to-3′ exoribonucleases in hyperthermophilic Euryarchaeota, the exosome was assumed to be the key enzyme in mRNA degradation in Archaea. By means of zymogram assays and bioinformatics, we have identified a 5′-to-3′ exoribonuclease activity in the crenarchaeum Sulfolobus solfataricus (Sso), which is affected by the phosphorylation state of the 5′-end of the mRNA. The protein comprises typical signature motifs of the β-CASP family of metallo-β-lactamases and was termed Sso-RNAse J. Thus, our study provides the first evidence for a 5′-to-3′ directional mRNA decay pathway in the crenarchaeal clade of Archaea. In Bacteria the 5′-end of mRNAs is often protected by a tri-phosphorylated 5′-terminus and/or by stem–loop structures, while in Eukaryotes the cap-binding complex is responsible for this task. Here, we show that binding of translation initiation factor a/eIF2(γ) to the 5′-end of mRNA counteracts the 5′-to-3′ exoribonucleolytic activity of Sso-RNase J in vitro. Hence, 5′-to-3′ directional decay and 5′-end protection appear to be conserved features of mRNA turnover in all kingdoms of life.
What else life if not awkward?
Authors: Corcoran Tim.
Published: November 2010

This article is a commentary on ‘Contemporary discursive psychology: Issues, prospects, and Corcoran's awkward ontology’, by Potter (2010).
Federalism and Tax Bonuses: Reflections in the Australian Context
Authors: Guy Scott , Hocking Barbara Ann
Published: November 2010

Keynesianism is not new in Australia, and indeed has represented the economic orthodoxy for much of the post-World War II period. Commonwealth governments, of both major political persuasions, have been able to work within the existing constitutional framework to pursue Keynesian economic policies, more or less successfully, albeit with the occasional legal setback depending upon interpretations of the High Court of Australia. Recently, like many governments, the Australian Federal Government responded to the 2008 global financial crisis (GFC) by proposing a ‘stimulus package’ whereby Australian consumers would ‘spend their way out of the crisis’. The particular package proposed was also so-called a ‘tax bonus' to be paid to those who earned under a certain (relatively generous) amount per annum and had submitted their tax returns in the previous year, 2008. This package was to be at the ‘front end’ of the government's response to the crisis. Our paper explores some recent dilemmas for Australian federalism in the light of the High Court decision which decided that those ‘bonuses' were constitutional. Yet while the High Court in Pape v Commissioner of Taxation1 upheld the constitutionality of what was formally known as the ‘Tax Bonus for Working Australians’—seeing the federal ‘stimulus package’ as a response to a global financial crisis that is a matter of international concern—it did so only by a bare majority (a four to three decision) in the highest court. We suggest that a reappraisal of Australian federalism is pertinent given this narrow majority and in the light of a claim by prominent constitutional law scholar George Williams that Australia continues to manifest a form of ‘sick federalism’. This is an appraisal made only the more acute with the recent Australian federal election, which resulted in a hung parliament, for the first time since 1940: this followed a campaign with no mention of the complexities and niceties of modern federalism.
Doubting What the Elders Have to Say: A Critical Examination of Canadian Judicial Treatment of Aboriginal Oral History Evidence
Authors: Milward David
Published: November 2010

The Supreme Court of Canada has articulated several legal principles that mandate the flexible and generous treatment of Aboriginal oral history evidence in support of Aboriginal rights claims. Lower courts, however, continue to devalue such evidence, often displaying explicit disregard for the legal principles, in order to defeat rights claims and subordinate Aboriginal interests to state sovereignty. This has no rational basis, since it is now clearly established that documentary historical evidence does not have any innate superiority over oral history evidence when it comes to ascertaining what happened in the past. This article proposes several solutions. These include educating judges on the potential value and accuracy of oral history evidence, enhancing oral history evidence through flexible use of the doctrines of inference and judicial notice, and using court-appointed experts to assure greater objectivity.
Same-Sex Domestic Violence: Why Victims are More at Risk
Authors: Tesch Brian , Bekerian Debra , English Peter , Harrington Evan
Published: November 2010

The purpose of this study was to examine police officers' general knowledge, experience and training in the area of same-sex domestic violence. A survey was administered to 91 police officers from 5 towns in Illinois. The study revealed that a majority of officers had encountered at least one same-sex domestic violence call within the last six months. In contrast, officers reported very little training in their departments regarding this issue. While previous research studies suggest that same-sex domestic violence and opposite-sex domestic violence have a roughly equivalent frequency rate, the current study finds that police officers are encountering same-sex domestic violence on a regular basis. However, a lack of training may render cases of same-sex violence more difficult for officers, as training in same-sex violence is not as readily available as is training for opposite-sex violence.
Organisational Practices of the Management of in-Service Training in the Turkish National Police: A Thematic Analysis
Authors: Zengin Cevdet
Published: November 2010

This paper examines organisational perspectives on the management of the in-service training function within the Turkish National Police. It is based on themes that emerged during an examination of Turkish academic and professional literature relating to policing and police training. The emerging training-related issues are grouped under the following thematic areas: (1) policy-making and central planning, (2) training needs analysis, (3) training research and development, (4) training delivery, (5) training evaluation, (6) employment of both training staff and trainees, and (7) inspection practices relating to the training function. The themes revealed that the organisational management of the in-service training function in the Turkish National Police (TNP) seems to be largely disintegrated and poorly aligned.
Sticks, Stones and Words: Emotional Harm and the English Criminal Law
Authors: Stannard John E.
Published: November 2010

This article discusses the rule that criminal liability does not normally attach for the causing of emotional harm or mental distress in the absence of proof of a ‘recognised psychiatric injury’. It considers what is involved in the diagnosis of psychiatric injury, and to what extent the difference between such injury and ‘ordinary’ mental distress is one of degree rather than one of kind. It reviews the situations in which the law already criminalises the infliction of emotional harm without proof of psychiatric injury, and assesses the policy arguments for drawing the distinction in the normal case. The article concludes that the law can and should adopt a more flexible approach to cases of this sort.
Where does evidentiality reside? Notes on (alleged) limiting cases: seem and be like
Authors: Lampert Günther , Lampert Martina
Published: November 2010

Standard definitions of evidentiality yield unwanted effects for alleged English evidentials: Some (like seem) do not specify an information source at all, but only schematically refer to it, others (like reporting verbs) are, in light of the envisaged cognitive-functional definition, best examples, yet are supposed to be (partially) excluded because of their non-lexicalized meanings. The present meta-study of conceptualizations of evidentiality, a far from trivial issue which must be settled before any database can be compiled, scrutinizes relevant parameters and applies them to two test cases, seem and ‘mediated’ evidentials, suggesting to conceptualize evidentiality as a multi-dimensional contextu­al category.
What counts as an evidential unit? The case of evidential complex constructions in Italian and Modern Greek
Authors: Pietrandrea Paola , Stathi Katerina
Published: November 2010

The evidential meaning traditionally attributed to modal auxiliaries is conveyed in Italian and Greek by complex constructions clustering both modal and aspectual features. The evidential reading of Italian and Greek modal auxiliaries, indeed, is only licenced when the modals take as complements stative, progressive, habitual or resultative subordinates. A feature of aspectual incompleteness of the subordinate is therefore necessary in order to obtain an evidential reading of the auxiliary. This leads us to propose the entire construction combining the auxiliary, the subordinate and the specification of its aspectual values be taken as an entry of the database of evidential units.
On the syntactic status of sentential adverbs and modal particles
Authors: Cruschina Silvio
Published: November 2010

This paper sets out a number of reasons for establishing a distinction between sentential (modal) adverbs and modal particles. Adverbs and particles are generally difficult to define as two distinct and independent word classes in terms of unitary criteria and distinctive properties. The traditional role of an adverb is that of modifying a verb or a verb phrase. In reality, adverbs also modify adjectives, sentences, and other adverbs. Particles also serve a sort of ‘modification’ function. Modal particles, for example, take the whole sentence as their object and fit its content to the context of speech. This ‘vague’ similarity, though, should not be interpreted as a motivation for assimilating the two categories, especially when other syntactic properties, such as the sentential position, the distribution, and the sensitivity to sentence types, together with their correlated semantic interpretations, are taken into consideration.
Probiotics and Prebiotics in Pediatrics
Authors: Thomas Dan W. , Greer Frank R. ,   Committee on Nutrition; Section on Gastroenterology, Hepatology, and Nutrition
Published: November 2010

This Clinical Report was reaffirmed March 2021.

This clinical report reviews the currently known health benefits of probiotic and prebiotic products, including those added to commercially available infant formula and other food products for use in children. Probiotics are supplements or foods that contain viable microorganisms that cause alterations of the microflora of the host. Use of probiotics has been shown to be modestly effective in randomized clinical trials (RCTs) in (1) treating acute viral gastroenteritis in healthy children; and (2) preventing antibiotic-associated diarrhea in healthy children. There is some evidence that probiotics prevent necrotizing enterocolitis in very low birth weight infants (birth weight between 1000 and 1500 g), but more studies are needed. The results of RCTs in which probiotics were used to treat childhood Helicobacter pylori gastritis, irritable bowel syndrome, chronic ulcerative colitis, and infantile colic, as well as in preventing childhood atopy, although encouraging, are preliminary and require further confirmation. Probiotics have not been proven to be beneficial in treating or preventing human cancers or in treating children with Crohn disease. There are also safety concerns with the use of probiotics in infants and children who are immunocompromised, chronically debilitated, or seriously ill with indwelling medical devices.

Prebiotics are supplements or foods that contain a nondigestible food ingredient that selectively stimulates the favorable growth and/or activity of indigenous probiotic bacteria. Human milk contains substantial quantities of prebiotics. There is a paucity of RCTs examining prebiotics in children, although there may be some long-term benefit of prebiotics for the prevention of atopic eczema and common infections in healthy infants. Confirmatory well-designed clinical research studies are necessary.
Identification and Management of Eating Disorders in Children and Adolescents
Authors: Rosen David S. ,   the Committee on Adolescence
Published: November 2010

The incidence and prevalence of eating disorders in children and adolescents has increased significantly in recent decades, making it essential for pediatricians to consider these disorders in appropriate clinical settings, to evaluate patients suspected of having these disorders, and to manage (or refer) patients in whom eating disorders are diagnosed. This clinical report includes a discussion of diagnostic criteria and outlines the initial evaluation of the patient with disordered eating. Medical complications of eating disorders may affect any organ system, and careful monitoring for these complications is required. The range of treatment options, including pharmacotherapy, is described in this report. Pediatricians are encouraged to advocate for legislation and policies that ensure appropriate services for patients with eating disorders, including medical care, nutritional intervention, mental health treatment, and care coordination.
Jean-Baptiste Bélanger: hydraulic engineer and academic
Authors: Chanson H.
Published: November 2010

Jean-Baptiste Bélanger (1790–1874) worked as a hydraulic engineer at the beginning of his career. He developed the backwater equation to calculate the free-surface profile of gradually varied, steady open channel flow. He also introduced the concept of critical flow and the numerical technique called the direct step method. Later, as an academic staff member at the leading French engineering schools (Ecole Centrale des Arts et Manufactures, Ecole des Ponts et Chaussées and Ecole Polytechnique), he developed a new university curriculum in mechanics and wrote several textbooks including a seminal text in hydraulic engineering. His influence on his contemporaries was considerable, and his name is written on the border of one of the four façades of the Eiffel Tower. Bélanger's leading role demonstrated the dynamism of practising engineers at the time, and his contributions paved the way to many significant works in hydraulics and fluid dynamics during the late nineteenth and early twentieth centuries.
An integrated conceptual framework for long‐term social–ecological research
Authors: Collins Scott L , Carpenter Stephen R , Swinton Scott M , Orenstein Daniel E , Childers Daniel L , Gragson Ted L , Grimm Nancy B , Grove J Morgan , Harlan Sharon L , Kaye Jason P , Knapp Alan K , Kofinas Gary P , Magnuson John J , McDowell William H , Melack John M , Ogden Laura A , Robertson G Philip , Smith Melinda D , Whitmer Ali C
Published: November 2010

The global reach of human activities affects all natural ecosystems, so that the environment is best viewed as a social–ecological system. Consequently, a more integrative approach to environmental science, one that bridges the biophysical and social domains, is sorely needed. Although models and frameworks for social–ecological systems exist, few are explicitly designed to guide a long‐term interdisciplinary research program. Here, we present an iterative framework, “Press–Pulse Dynamics” (PPD), that integrates the biophysical and social sciences through an understanding of how human behaviors affect “press” and “pulse” dynamics and ecosystem processes. Such dynamics and processes, in turn, influence ecosystem services –thereby altering human behaviors and initiating feedbacks that impact the original dynamics and processes. We believe that research guided by the PPD framework will lead to a more thorough understanding of social–ecological systems and generate the knowledge needed to address pervasive environmental problems.
Turning Points in the Progression of Obsessive Relational Intrusion and Stalking
Authors: Mumm Sai Sato , Cupach William R.
Published: November 2010

This study examined the critical events defining the temporal progression of unwanted relationship pursuit. Retrospective interviews elicited the experiences of 42 victims of obsessive relational intrusion (ORI) and its extreme manifestation, stalking. Participants described turning points within their ORI experiences, and constructed graphs representing the progression of turning points over time in terms of changes in perceived severity. Inductive data analysis revealed 17 distinct turning point types. Some turning point types were associated with increases in ORI severity and others were associated with decreases. Five temporal trajectories of ORI progression also were identified. Results indicate that ORI does not necessarily progress along linear and continuous paths. Some findings support coping advice commonly given to victims of ORI and stalking.
Does Community Violence Exposure Predict Trauma Symptoms in a Sample of Maltreated Youth in Foster Care?
Authors: Garrido Edward F. , Culhane Sara E. , Raviv Tali , Taussig Heather N.
Published: November 2010

Previous studies find that childhood exposure to family and community violence is associated with trauma symptoms. Few studies, however, have explored whether community violence exposure (CVE) predicts trauma symptoms after controlling for the effects associated with family violence exposure (FVE). In the current study, CVE and FVE were examined in a sample of 179 youth with a recent history of maltreatment. CVE was associated with trauma symptoms after controlling for FVE, but FVE was not associated with trauma symptoms after controlling for CVE. In addition, negative coping strategies (e.g., self-harm, interpersonal aggression) partially mediated the association between CVE and trauma symptoms. These findings are discussed in terms of their implications for interventions aimed at addressing the needs of children exposed to violence.
The Impact of Childhood Sexual Abuse and Intimate Partner Violence on Sexually Transmitted Infections
Authors: Williams Corrine , Larsen Ulla , McCloskey Laura Ann
Published: November 2010

Childhood sexual abuse (CSA) and adult intimate partner violence (IPV) have both been found to be associated with sexually transmitted infections (STIs) independently, but studies of STIs have rarely looked at victimization during both childhood and adulthood. This paper examines the relationship between CSA, IPV and STIs using data from a nested casecontrol study of 309 women recruited from multiple health care settings. Overall, 37.3% of women experienced no violence, 10.3% experienced CSA only, 27.3% experienced IPV only, and 25.0% experienced both CSA and IPV. Having ever been diagnosed with an STI was associated with violence (CSA only, odds ratios [OR] = 2.8, 95% confidence intervals [CI] = 1.0–7.5; IPV only, OR = 2.2, 95% CI = 1.0–4.9; CSA and IPV: OR = 4.0, 95% CI = 1.7–9.4), controlling for demographic characteristics. Women who experienced CSA were younger when they were first diagnosed. Understanding how both childhood and adult victimization are associated with diagnosis of STIs is important to reducing the incidence and prevalence of STIs, as well as the associated consequences of STIs.
Psychometric Properties of the Arabic Version of the Depressive Cognition Scale in First-Year Adolescent Egyptian Nursing Students
Authors: Bekhet Abir K. , Zauszniewski Jaclene A.
Published: November 2010

Background: Identifying depressive cognitions in adolescent nursing students can be an important step to prevent the development of clinical depression, which is positively associated with suicide. Purpose: This study focused on the psychometric testing of the Arabic version of the Depressive Cognition Scale (A-DCS) among 170 first-year adolescent Egyptian nursing students. Methods: The questionnaire was assessed for internal consistency, homogeneity, and construct validity using factor analysis and convergent validity. Results: CronbachÊs alpha for (A-DCS) was .86. The homogeneity of the instrument was supported by item-to-total correlations between .30 and .70. Factor extraction generated only one factor with eigenvalues greater than 1, which is consistent with the English version. The (A-DCS) total score had a strong significant correlation with the Alienation Scale scores (r = .51, p < .01), indicating convergent validity. Conclusion: This scale has the potential to become a useful screening tool for depressive cognitions among Egyptian nursing students.
Review of Scales of Parenting Confidence
Authors: Črnčec Rudi , Barnett Bryanne , Matthey Stephen
Published: November 2010

Interest in the measurement of parenting confidence in research and clinical contexts has grown considerably in recent decades, particularly in the area of health care. Psychometric and technical characteristics of scales assessing this construct suitable for the parents of children aged 0–12 years were reviewed in this research. In so doing, information is provided that will assist clinicians and researchers in selecting a measure suitable to their needs. Thirty-six instruments assessing parenting confidence were located. Two dominant approaches to item selection were evident: (1) general items suitable for a range of child ages, or (2) task-specific items suitable for parents of a child of a particular age. Psychometrically, most scales possessed adequate reliability data, although validity data for many scales was limited. In addition, only two of the instruments, both with general items, had stratified normative data. Scales appropriate for a range of research purposes and some clinical applications are available. Further research is necessary to provide normative data for task-specific parenting confidence scales.
A Simple and Accurate Model for Well Productivity for Hydraulically Fractured Wells
Authors: Friehauf Kyle E. , Suri Ajay , Sharma Mukul M.
Published: November 2010

A new model is developed that calculates the productivity of a hydraulically fractured well, including the effect of fracture-face damage caused by fluid leakoff. Results of the new model are compared with three previous models (McGuire and Sikora 1960; Prats 1961; Binder and Raymond 1967). The existing models assume either elliptical or radial flow around the well, with permeability varying azimuthally. Significant differences in the calculated well productivity indicate that earlier assumptions made regarding the flow geometry can lead to significant overestimates of well productivity index (PI). Agreement with the analytical solution of Prats (1961) is achieved for finite-conductivity fractures and no fracture damage. It is shown that the use of either McGuire's model (McGuire and Sikora 1960) or Raymond's model (Binder and Raymond 1967) to estimate improvement in well PI in fractured wells can lead to a significant overestimation of the well PI. The new model provides a useful tool to quickly calculate the productivity of wells that have both a finite-conductivity fracture and damage in the invaded zone. The simple and discrete nature of the model makes it ideal for implementation in spreadsheets and to connect to fracture-performance models.

Cleanup of the damage in the invaded zone depends on the capillary properties of the formation and the drawdown pressure applied across the damaged zone during production. If capillary forces are small and drawdown pressure is high, the water will be recovered, resulting in negligible damage. It is found that the invaded zone will cause significant damage when the permeability of the damaged zone is reduced by more than 90%. For low-permeability, depleted formations where water recovery is poor, the fracturing fluid should be energized with a gas component so that the relative permeability damage to gas inflow can be minimized.
The Effect of Gas on the Injectivity of Particles in Sandstone
Authors: Nguyen Q.P.. P. , Currie Peter K. , Bouzanga P.S.R.. S.R.
Published: November 2010

Many operations involve the injection of fluids into the formation around a well. In many cases, the fluids contain colloidal particles, either initially present or introduced during the operation through dirt or naturally occurring particles. Therefore, all injection schemes potentially suffer from injectivity decline. This injectivity decline is caused by clogging of the formation by particles, forming an external filter cake on the surface of the formation and blocking the pores inside the formation.

This paper reports on the effects of gas on the injectivity of particles in sandstone. Experiments were performed in which water containing micron-sized particles (hematite) was injected into sandstone cores with or without small gas bubbles (nitrogen) present in the water. The position and amount of particle deposition could be determined both visually and by chemical analysis. It was found that the presence of gas reduces the external filter cake formed on the inlet surface of the core. Also, with gas, the particles penetrate deeper inside the core and more particles pass through the core and are detected in the effluent stream.

The same effects are enhanced when the mixture of gas bubbles and water is replaced by foam. This suggests that the presence of gas/water interfaces has a major influence on the retention of particles in the sandstone. Possible mechanisms are discussed.

The pressure drop across the core when gas or foam is present is initially higher than in an identical test without gas because of relative permeability effects or foam-flow resistance. However, because fewer particles are retained, ultimately the pressure drop is significantly less when gas is present. This effect may be significant in injection operations involving foam and offers ways to mitigate injectivity loss.
Data Assimilation Using the Constrained Ensemble Kalman Filter
Authors: Phale Hemant A. , Oliver Dean S.
Published: November 2010

When the ensemble Kalman filter (EnKF) is used for history matching, the resulting updates to reservoir properties sometimes exceed physical bounds, especially when the problem is highly nonlinear. Problems of this type are often encountered during history matching compositional models using the EnKF. In this paper, we illustrate the problem using an example in which the updated molar density of CO2 in some regions is observed to take negative values while molar densities of the remaining components are increased. Standard truncation schemes avoid negative values of molar densities but do not address the problem of increased molar densities of other components. The results can include a spurious increase in reservoir pressure with a subsequent inability to maintain injection. In this paper, we present a method for constrained EnKF (CEnKF), which takes into account the physical constraints on the plausible values of state variables during data assimilation. In the proposed method, inequality constraints are converted to a small number of equality constraints, which are used as virtual observations for calibrating the model parameters within plausible ranges.

The CEnKF method is tested on a 2D compositional model and on a highly heterogeneous three-phase-flow reservoir model. The effect of the constraints on mass conservation is illustrated using a 1D Buckley-Leverett flow example. Results show that the CEnKF technique is able to enforce the nonnegativity constraints on molar densities and the bound constraints on saturations (all phase saturations must be between 0 and 1) and achieve a better estimation of reservoir properties than is obtained using only truncation with the EnKF.
Sour Serviceability of Higher-Strength Coiled Tubing: Final Results
Authors: Padron Tomas
Published: November 2010

As early as 1999, the need for industry guidelines regarding the use of coiled tubing (CT) in sour wells was recognized (Luft and Wilde 1999). Small-scale standard National Assocation of Corrosion Engineers (NACE) tests (i.e., proof-ring, C-ring, double-cantilever-beam, and slow-strain-rate tests) have been performed to evaluate the behavior of CT materials in sour environments (Cayard and Kane 1997; McCoy 2005; McCoy and Thomas 2006; Luft 2003). Although these tests evaluate the crack-resistance properties of the material in sour conditions, they do not give data regarding the low-cycle fatigue performance of CT after sour exposure that could be used for CT-string management in real operating conditions.

By 2003, uniaxial low-cycle corrosion fatigue tests of short, full-body CT samples were used to evaluate the sour performance of Grade-70 and -80 materials (Luft 2003). These tests, although they considered fatigue performance, were based on uniaxial reversing loads rather than reversing bending strains, which is what occurs in CT operations. In addition to this, the need for high-strength CT materials (i.e., 90-grade and higher) in sour wells required additional knowledge regarding their sour performance.

By the end of 2004, a joint-industry project (JIP) among ExxonMobil Development Company, Shell Canada Limited, and BJ Services Company was initiated to investigate the serviceability of high-strength CT in sour environments, with the main emphasis on the measurement of low-cycle bending-fatigue life after sour exposure using full-body CT samples. Some of the early results of this project were included in a previous paper (Luft et al. 2007).

The present paper summarizes more than 4 years of laboratory testing aimed at establishing the effect of sour exposure on the low-cycle fatigue life of CT materials. Other aspects related to the possible CT degradation from sour exposure are also included, such as the effect of varying sour-environment severities, performance of anticracking (H2S) inhibitors, effect of prefatigue, butt- and bias- weld performance, and tensile-strength integrity. The results have led to changes in the current operating procedures regarding CT-strings management and CT-material selection criteria for sour service.
Effect of Elasticity During Viscoelastic Polymer Flooding: A Possible Mechanism of Increasing the Sweep Efficiency
Authors: Urbissinova Tolkynay S. , Trivedi Japan , Kuru Ergun
Published: November 2010

It has been long believed that the viscoelasticity of polymer solution improves the displacement efficiency in polymer flood operations, but the individual effect of elasticity has not been clearly distilled for a single viscoelastic polymer. In this study, the effect of elasticity of polymer-based fluids on the microscopic sweep efficiency is investigated by injecting two polymer solutions with similar shear viscosity, but significantly different elastic characteristics.

Blends of various grades of polyethylene oxide (PEO) with similar average molecular weight and different molecular weight distribution (MWD) were prepared by dissolving in deionized water. The polymer solutions exhibited identical shear viscosity, but different elasticity. A series of experiments were performed by injecting the polymer solutions through a sandpack saturated with mineral oil. The experiments were performed using a special core holder designed to simulate radial flow. Injection was done through a perforated injection line located at the centre of the cell and fluids were produced through two production lines located at the periphery. The experiments were conducted within a shear rate range of field applications. Because both polymer solutions had similar shear viscosity behaviour, but different elastic properties, it was possible to see the effect of elasticity on the sweep efficiency alone.

Results of the polymer flooding experiments indicated that the sweep efficiency of a polymeric fluid could be effectively improved by adjusting the MWD of the solution at constant shear viscosity and polymer concentration. The polymer solution with higher elasticity exhibited considerably higher resistance to flow through porous media than the one with lower elasticity, resulting in higher sweep efficiency and lower residual oil saturation.
Managing Drilling Vibrations Through BHA Design Optimization
Authors: Bailey J.R.. R. , Remmert S.M.. M.
Published: November 2010

Significant performance improvement has been achieved by successfully managing drilling vibrations through bottomhole-assembly (BHA) redesign. This effort has resulted in increased footage per day and reduced tool damage. Prior literature has described improvements in operating practices to manage vibrations (Dupriest et al. 2005; Remmert et al. 2007) as a key component of this rate-of-penetration management process. In a parallel work activity, BHA redesign efforts have provided additional performance improvements of approximately 36% in one drilling application. Dynamic modeling of the BHA has identified the key design changes leading to these improvements. The redesigned BHA has lower calculated vibration indices than the standard BHA.

The BHA design evaluation process uses a frequency-domain lateral dynamic model in both predrill forecast and post-drill hindcast modes. BHA lateral vibrations are characterized such that alternative BHA configurations may be developed and compared directly with a proposed baseline assembly. In the hindcast mode, the BHA model can be operated at the recorded weight on bit (WOB) and revolutions per minute (RPM) to generate corresponding model results in time or depth, and these values can be compared with the measured performance data.

In one case study, the redesign of a BHA with downhole motor and roller reamer is described, with corresponding field data for four original BHAs and four redesigned assemblies. In a second application, model and field drilling results for two rotary-steerable assemblies are compared to evaluate the predictive ability of the model in smaller hole size and with different BHA types. Finally, the utility of the model to identify preferred rotary-speed "sweet spots" is demonstrated in a motor BHA operating in larger hole.
Passive Reservoir Heating for Improved Bitumen Recovery
Authors: Cimolai Mauro P. , Solanki S.C. , Edmunds Neil
Published: November 2010

A new strategy for heavy oil recovery is identified for layered reservoirs, where hydraulic restrictions or barriers to vertical flow separate adjacent oil-saturated strata. Passive heat conduction from a thermal operation in one layer is used to preheat bitumen in the adjacent strata. Once preheated, the oil properties within the adjacent strata are favourably conditioned to either primary production or the effective in-situ application of solvents. This strategy permits greater thermal efficiency for heat either applied or generated within the reservoir, producing a higher recovery and access to otherwise uneconomic pay intervals.

A key insight in the passive heating assisted recovery method (PHARM) process is that the reservoir is preheated without the introduction of a secondary working fluid for heat transfer. To the exploitation of the secondary zone, this forms something of an ideal situation. In thermal, solvent-assisted or pure solvent applications, a means of heating heavy oils is essential to an economically effective process. Commonly, heat is introduced to the formation directly by means of a preheated working fluid. Working fluids, such as steam or condensing solvents, carry related costs, design restrictions and potential productivity impairment limitations with their application. If heat otherwise lost from an offsetting thermal process, or in-situ heat generated from waste fuel in offsetting strata, can be harnessed, the desired bitumen heating can be achieved independent to the introduction of an in-situ working fluid for heat transfer. Limitations inherent to the cycling of a working fluid for heat transfer are consequently overcome.

As an example, the PHARM strategy can be applied within the bitumen-saturated Grosmont formation, per the geological stratification within Laricina's Saleski project. Here, the Upper Grosmont C and D strata are separated by a regional marlstone, which, in areas forming a vertical hydraulic flow restriction, does not constitute a thermal barrier. Thermal processes in either layer will passively heat the adjacent strata by conduction. The preheated bitumen layer, rather than presenting a process heat loss, can now be more effectively exploited. The inherent advantage permits incremental bitumen volumes to be accessed at a markedly reduced CSOR equivalent. For a steam assisted gravity drainage (SAGD) process, a generic example provided illustrates an overall CSOR reduction from 3.2-2.5 for primary drainage, with potential system CSOR reductions below two with the application of solvents. Solvents further permit access to a significantly lower-permeability reservoir where the host rock below 100 md may be resourced.
Feasibility of Focused‐Pulsed Treated Waste Activated Sludge as a Supplemental Electron Donor for Denitrification
Authors: Lee Il‐Su , Parameswaran Prathap , Alder Jared M. , Rittmann Bruce E.
Published: November 2010

We evaluated the feasibility of using waste activated sludge (WAS) from a wastewater treatment plant as an internal electron donor to fuel denitrification, by increasing its bioavailability with Focused‐Pulsed (FP) technology. The focused‐pulsed treatment of WAS (producing FP‐WAS) increased the semi‐soluble chemical oxygen demand (SSCOD) by 26 times compared with the control WAS. The maximum denitrification rate of FP‐WAS (0.25 g nitrate‐nitrogen [NO3−‐N]/g volatile suspended solids [VSS]·d) was greater than for untreated WAS (0.05 g NO3−‐N/g VSS·d) and methanol (0.15 NO3−‐N/g VSS·d). Centrifuging out the larger suspended solids created FP‐centrate, which had a rate (0.14 g NO3−‐N/g VSS·d) comparable with that of methanol. Thus, FP treatment of WAS created SSCOD, which was an internal electron donor that was able to drive denitrification at a rate similar to or greater than methanol. One trade‐off of using FP‐WAS for denitrification is an increase in total Kjeldahl nitrogen (TKN) loading. While FP‐WAS achieved the lowest total nitrogen and NO3−‐N concentrations in the batch denitrification test, its final ammonia‐nitrogen (NH3‐N) concentration was the highest, as a result of the release of organic nitrogen from the FP‐treated biomass; FP‐centrate had less release of total soluble nitrogen. While the return of total nitrogen (TN) is small compared with the SSCOD, the effects of the added nitrogen loading need to be considered.
Using Risk Analysis to Predict Design Flow Exceedance of Decentralized Wastewater Management Systems
Authors: Dobbs Patrick A. , Cox Chris D. , Tyner John S. , Buchanan John R.
Published: November 2010

In small communities, the number of residential units is a more stable indicator of wastewater volume than population. Large communities benefit from averaging because the likelihood of having concurrent large flows from all users is small. In contrast, a single septic system connected to a single residence must be designed to accommodate large flow variations. The objective of this study was to determine the risk of assigning various daily wastewater volumes to residential units. Risk was based on the probability of underestimating daily volume and, therefore, exceeding the capacity of the system. This study concluded that assigning a value of 950 L/d per residence (250 gpd per residence) is appropriate for communities with 15 or more residences, and that assigning a value of 850 L/d per residence (225 gpd per residence) is appropriate for communities with 30 or more residential connections.
Corrosion Control When Using Secondary Treated Municipal Wastewater as Alternative Makeup Water for Cooling Tower Systems
Authors: Hsieh Ming‐Kai , Li Heng , Chien Shih‐Hsiang , Monnell Jason D. , Chowdhury Indranil , Dzombak David A. , Vidic Radisav D.
Published: November 2010

Secondary treated municipal wastewater is a promising alternative to fresh water as power plant cooling water system makeup water, especially in arid regions. Laboratory and field testing was conducted in this study to evaluate the corrosiveness of secondary treated municipal wastewater for various metals and metal alloys in cooling systems. Different corrosion control strategies were evaluated based on varied chemical treatment. Orthophosphate, which is abundant in secondary treated municipal wastewater, contributed to more than 80% precipitative removal of phosphorous‐based corrosion inhibitors. Tolyltriazole worked effectively to reduce corrosion of copper (greater than 95% inhibition effectiveness). The corrosion rate of mild steel in the presence of free chlorine 1 mg/L (as Cl2) was approximately 50% higher than in the presence of monochloramine 1 mg/L (as Cl2), indicating that monochloramine is a less corrosive biocide than free chlorine. The scaling layers observed on the metal alloys contributed to corrosion inhibition, which could be seen by comparing the mild steel 21‐day average corrosion rate with the last 5‐day average corrosion rate, the latter being approximately 50% lower than the former.
Boundary Layer Separation Method for Recycling of Sodium Ions from Industrial Wastewater
Authors: Pethő Dóra , Horváth Géza , Liszi János , Tóth Imre , Paor Dávid
Published: November 2010

The most effective technological solution for waste treatment is recycling. We have developed a new method for the treatment of industrial wastewaters and have called it the boundary layer separation method (BLSM). We have used the phenomenon that, on the surface of an electrically charged electrode, ions can be enriched in the boundary layer, as compared with the inside of the phase. The essence of the method is that, with an appropriately chosen velocity, the boundary layer can be removed from the wastewater, and the boundary layer, which is rich in ions, can be recycled. The BLSM can be executed as a cyclic procedure. The capacitance of the boundary layer was examined. The best mass transport can be achieved with the use of 1000 and 1200 mV polarization potentials in the examined system, with its value being 1200 mg/m2 per cycle. The necessary operation times were determined by the examination of the velocity of the electrochemical processes. When using 1000 mV polarization potential, the necessary adsorption time is at least 25 seconds, and the desorption time at least 300 seconds. The advantage of the procedure is that it does not use dangerous chemicals, only inert electrodes. The drawback is that it is not selective to ions, the achievable separation in one step is low, and the hydrogen that emerges during the electrolysis might be dangerous.