bluuebunny/crossref_metadata_2025 huggingface dataset:
Genome sequence of the necrotrophic plant pathogen Pythium ultimum reveals original pathogenicity mechanisms and effector repertoire
Authors: Lévesque C André , Brouwer Henk , Cano Liliana , Hamilton John P , Holt Carson , Huitema Edgar , Raffaele Sylvain , Robideau Gregg P , Thines Marco , Win Joe , Zerillo Marcelo M , Beakes Gordon W , Boore Jeffrey L , Busam Dana , Dumas Bernard , Ferriera Steve , Fuerstenberg Susan I , Gachon Claire MM , Gaulin Elodie , Govers Francine , Grenville-Briggs Laura , Horner Neil , Hostetler Jessica , Jiang Rays HY , Johnson Justin , Krajaejun Theerapong , Lin Haining , Meijer Harold JG , Moore Barry , Morris Paul , Phuntmart Vipaporn , Puiu Daniela , Shetty Jyoti , Stajich Jason E , Tripathy Sucheta , Wawra Stephan , van West Pieter , Whitty Brett R , Coutinho Pedro M , Henrissat Bernard , Martin Frank , Thomas Paul D , Tyler Brett M , De Vries Ronald P , Kamoun Sophien , Yandell Mark , Tisserat Ned , Buell C Robin
Published: August 2010

Background

Pythium ultimum is a ubiquitous oomycete plant pathogen responsible for a variety of diseases on a broad range of crop and ornamental species.

Results

The P. ultimum genome (42.8 Mb) encodes 15,290 genes and has extensive sequence similarity and synteny with related Phytophthora species, including the potato blight pathogen Phytophthora infestans. Whole transcriptome sequencing revealed expression of 86% of genes, with detectable differential expression of suites of genes under abiotic stress and in the presence of a host. The predicted proteome includes a large repertoire of proteins involved in plant pathogen interactions, although, surprisingly, the P. ultimum genome does not encode any classical RXLR effectors and relatively few Crinkler genes in comparison to related phytopathogenic oomycetes. A lower number of enzymes involved in carbohydrate metabolism were present compared to Phytophthora species, with the notable absence of cutinases, suggesting a significant difference in virulence mechanisms between P. ultimum and more host-specific oomycete species. Although we observed a high degree of orthology with Phytophthora genomes, there were novel features of the P. ultimum proteome, including an expansion of genes involved in proteolysis and genes unique to Pythium. We identified a small gene family of cadherins, proteins involved in cell adhesion, the first report of these in a genome outside the metazoans.

Conclusions

Access to the P. ultimum genome has revealed not only core pathogenic mechanisms within the oomycetes but also lineage-specific genes associated with the alternative virulence and lifestyles found within the pythiaceous lineages compared to the Peronosporaceae.
Concomitant Enzyme-Linked Immunosorbent Assay Measurements of Rat Insulin, Rat C-Peptide, and Rat Proinsulin from Rat Pancreatic Islets: Effects of Prolonged Exposure to Different Glucose Concentrations
Authors: Carlsson Annika , Hallgren Ing-Britt , Johansson Hanna , Sandler Stellan
Published: August 2010

Until now, there have been few assays to measure C-peptide and proinsulin in the rat. We used a well-established rat insulin ELISA and validated two novel ELISAs for rat C-peptide and rat/mouse proinsulin to examine secretion and content of insulin, proinsulin, and C-peptide from rat islets cultured for 72 h at different glucose concentrations in culture medium. To examine long-term effects in vitro rather than short-term effects of exposure to low, normal, and high glucose, the exposure time to the different glucose concentrations was set to 72 h. The measurement uncertainty of the values obtainable from the ELISAs was determined by calculation of the variation pattern from the intraassay variation generated by unknown samples, and repeatability was determined by analysis of controls. The precision study and the analysis of controls confirm that the validated ELISAs for rat C-peptide and proinsulin would be useful for further studies on the effects of preculture in different glucose concentrations. The higher the glucose concentration used during the 72-h culture period of rat islets, the higher insulin, C-peptide and proinsulin values were obtained in a subsequent short-term glucose-challenge experiment. The proportion of proinsulin to insulin secreted increased, as did islet content, with increasing glucose concentration during preculture. We also observed a nonequimolar, glucose-dependent secretion and content of rat insulin over rat C-peptide after culture at 11.1 and 28 mm glucose.
Mechanism of Attenuation of Skeletal Muscle Atrophy by Zinc-α2-Glycoprotein
Authors: Russell Steven T. , Tisdale Michael J.
Published: August 2010

The mechanism by which the adipokine zinc-α2-glycoprotein (ZAG) increases the mass of gastrocnemius, but not soleus muscle of diabetic mice, has been evaluated both in vivo and in vitro. There was an increased phosphorylation of both double-stranded RNA-dependent protein kinase and its substrate, eukaryotic initiation factor-2α, which was attenuated by about two-thirds in gastrocnemius but not soleus muscle of ob/ob mice treated with ZAG (50 μg, iv daily) for 5 d. ZAG also reduced the expression of the phospho forms of p38MAPK and phospholipase A2, as well as expression of the ubiquitin ligases (E3) muscle atrophy F-box/atrogin-1 and muscle RING finger protein, and the increased activity of both caspase-3 and casapse-8 to values found in nonobese controls. ZAG also increased the levels of phospho serine-threonine kinase and mammalian target of rapamycin in gastrocnemius muscle and reduced the phosphorylation of insulin receptor substrate-1 (Ser307) associated with insulin resistance. Similar changes were seen with ZAG when murine myotubes were incubated with high glucose concentrations (10 and 25 mm), showing that the effect of ZAG was direct. ZAG produced an increase in cAMP in murine myotubes, and the effects of ZAG on protein synthesis and degradation in vitro could be replicated by dibutyryl cAMP. ZAG increased cAMP levels of gastrocnemius but not soleus muscle. These results suggest that protein accretion in skeletal muscle in response to ZAG may be due to changes in intracellular cAMP and also that ZAG may have a therapeutic application in the treatment of muscle wasting conditions.
Impact of Monocarboxylate Transporter-8 Deficiency on the Hypothalamus-Pituitary-Thyroid Axis in Mice
Authors: Trajkovic-Arsic Marija , Müller Julia , Darras Veerle M. , Groba Claudia , Lee Sooyeon , Weih Debra , Bauer Karl , Visser Theo J. , Heuer Heike
Published: August 2010

In patients, inactivating mutations in the gene encoding the thyroid hormone-transporting monocarboxylate transporter 8 (Mct8) are associated with severe mental and neurological deficits and disturbed thyroid hormone levels. The latter phenotype characterized by high T3 and low T4 serum concentrations is replicated in Mct8 knockout (ko) mice, indicating that MCT8 deficiency interferes with thyroid hormone production and/or metabolism. Our studies of Mct8 ko mice indeed revealed increased thyroidal T3 and T4 concentrations without overt signs of a hyperactive thyroid gland. However, upon TSH stimulation Mct8 ko mice showed decreased T4 and increased T3 secretion compared with wild-type littermates. Moreover, similar changes in the thyroid hormone secretion pattern were observed in Mct8/Trhr1 double-ko mice, which are characterized by normal serum T3 levels and normal hepatic and renal D1 expression in the presence of very low T4 serum concentrations. These data strongly indicate that absence of Mct8 in the thyroid gland affects thyroid hormone efflux by shifting the ratio of the secreted hormones toward T3. To test this hypothesis, we generated Mct8/Pax8 double-mutant mice, which in addition to Mct8 lack a functional thyroid gland and are therefore completely athyroid. Following the injection of these animals with either T4 or T3, serum analysis revealed T3 concentrations similar to those observed in Pax8 ko mice under thyroid hormone replacement, indicating that indeed increased thyroidal T3 secretion in Mct8 ko mice represents an important pathogenic mechanism leading to the high serum T3 levels.
Impact of Type of Preadmission Sulfonylureas on Mortality and Cardiovascular Outcomes in Diabetic Patients with Acute Myocardial Infarction
Authors: Zeller Marianne , Danchin Nicolas , Simon Dominique , Vahanian Alec , Lorgis Luc , Cottin Yves , Berland Jacques , Gueret Pascal , Wyart Pascal , Deturck Régis , Tabone Xavier , Machecourt Jacques , Leclercq Florence , Drouet Elodie , Mulak Geneviève , Bataille Vincent , Cambou Jean-Pierre , Ferrieres Jean , Simon Tabassome ,   For the French Registry of Acute ST-Elevation and Non-ST-Elevation Myocardial Infarction investigators
Published: August 2010

Background: The impact of antidiabetic medications on clinical outcomes in patients developing acute myocardial infarction (MI) is controversial. We sought to determine whether in-hospital outcomes in patients who were on sulfonylureas (SUs) when they developed their MIs differed from that of diabetic patients not receiving SUs and whether clinical outcomes were related to the pancreatic cells specificity of SUs.

Methods and Results: We analyzed the outcomes of the 1310 diabetic patients included in the nationwide French Registry of Acute ST-Elevation and Non-ST-Elevation Myocardial Infarction in 2005. Medications used before the acute episode were recorded. In-hospital complications were analyzed according to prior antidiabetic treatment. Mortality was lower in patients previously treated with SUs (3.9%) vs. those on other oral medications (6.4%), insulin (9.4%), or no medication (8.4%) (P = 0.014). Among SU-treated patients, in-hospital mortality was lower in patients receiving pancreatic cells-specific SUs (gliclazide or glimepiride) (2.7%), compared with glibenclamide (7.5%) (P = 0.019). Arrhythmias and ischemic complications were also less frequent in patients receiving gliclazide/glimepiride. The lower risk in patients receiving gliclazide/glimepiride vs. glibenclamide persisted after multivariate adjustment (odds ratio 0.15; 95% confidence interval 0.04–0.56) and in propensity score-matched cohorts.

Conclusion: In this nationwide registry of patients hospitalized for acute MI, no hazard was associated with the use of SUs before the acute episode. In addition, patients previously receiving gliclazide/glimepiride had improved in-hospital outcomes, compared with those on glibenclamide.
Altered Retinoid Uptake and Action Contributes to Cell Survival in Endometriosis
Authors: Pavone Mary Ellen , Reierstad Scott , Sun Hui , Milad Magdy , Bulun Serdar E. , Cheng You-Hong
Published: August 2010

Context: Retinoic acid (RA) controls multiple biological processes via exerting opposing effects on cell survival. Retinol uptake into cells is controlled by stimulated by RA 6 (STRA6). RA is then produced from retinol in the cytosol. Partitioning of RA between the nuclear receptors RA receptor α and peroxisome-proliferator-activated receptor β/δ is regulated by cytosol-to-nuclear shuttling proteins cellular RA binding protein 2 (CRABP2) and fatty acid binding protein 5 (FABP5), which induce apoptosis or enhance survival, respectively. The roles of these mechanisms in endometrium or endometriosis remain unknown.

Objective: The aim was to determine the regulation of retinoid uptake and RA action in primary stromal cells from endometrium (n = 10) or endometriosis (n = 10).

Results: Progesterone receptor was necessary for high STRA6 and CRABP2 expression in endometrial stromal cells. STRA6, which was responsible for labeled retinoid uptake, was strikingly lower in endometriotic cells compared to endometrial cells. CRABP2 knockdown in endometrial cells increased survival, and FABP5 knockdown in endometriotic cells decreased survival without altering the expression of downstream nuclear retinoic acid receptor α and peroxisome-proliferator-activated receptor β/δ.

Conclusions: In endometrial stromal cells, progesterone receptor up-regulates expression of STRA6 and CRABP2, which control retinol uptake and growth-suppressor actions of RA. In endometriotic stromal cells, decreased expression of these genes leads to decreased retinol uptake and dominant FABP5-mediated prosurvival activity.
An SNP in an ultraconserved regulatory element affects Dlx5/Dlx6 regulation in the forebrain
Authors: Poitras Luc , Yu Man , Lesage-Pelletier Cindy , MacDonald Ryan B. , Gagné Jean-Philippe , Hatch Gary , Kelly Isabelle , Hamilton Steven P. , Rubenstein John L. R. , Poirier Guy G. , Ekker Marc
Published: August 2010

Dlx homeobox genes play a crucial role in the migration and differentiation of the subpallial precursor cells that give rise to various subtypes of γ-aminobutyric acid (GABA)-expressing neurons of the forebrain, including local-circuit cortical interneurons. Aberrant development of GABAergic interneurons has been linked to several neurodevelopmental disorders, including epilepsy, schizophrenia, Rett syndrome and autism. Here, we report in mice that a single-nucleotide polymorphism (SNP) found in an autistic proband falls within a functional protein binding site in an ultraconserved cis-regulatory element. This element, I56i, is involved in regulating Dlx5/Dlx6 homeobox gene expression in the developing forebrain. We show that the SNP results in reduced I56i activity, predominantly in the medial and caudal ganglionic eminences and in streams of neurons tangentially migrating to the cortex. Reduced activity is also observed in GABAergic interneurons of the adult somatosensory cortex. The SNP affects the affinity of Dlx proteins for their binding site in vitro and reduces the transcriptional activation of the enhancer by Dlx proteins. Affinity purification using I56i sequences led to the identification of a novel regulator of Dlx gene expression, general transcription factor 2 I (Gtf2i), which is among the genes most often deleted in Williams-Beuren syndrome, a neurodevelopmental disorder. This study illustrates the clear functional consequences of a single nucleotide variation in an ultraconserved non-coding sequence in the context of developmental abnormalities associated with disease.
Arterial pole progenitors interpret opposing FGF/BMP signals to proliferate or differentiate
Authors: Hutson Mary Redmond , Zeng Xiaopei Lily , Kim Andrew J. , Antoon Emily , Harward Stephen , Kirby Margaret L.
Published: August 2010

During heart development, a subpopulation of cells in the heart field maintains cardiac potential over several days of development and forms the myocardium and smooth muscle of the arterial pole. Using clonal and explant culture experiments, we show that these cells are a stem cell population that can differentiate into myocardium, smooth muscle and endothelial cells. The multipotent stem cells proliferate or differentiate into different cardiovascular cell fates through activation or inhibition of FGF and BMP signaling pathways. BMP promoted myocardial differentiation but not proliferation. FGF signaling promoted proliferation and induced smooth muscle differentiation, but inhibited myocardial differentiation. Blocking the Ras/Erk intracellular pathway promoted myocardial differentiation, while the PLCγ and PI3K pathways regulated proliferation. In vivo, inhibition of both pathways resulted in predictable arterial pole defects. These studies suggest that myocardial differentiation of arterial pole progenitors requires BMP signaling combined with downregulation of the FGF/Ras/Erk pathway. The FGF pathway maintains the pool of proliferating stem cells and later promotes smooth muscle differentiation.
Interaction Analyses of Amyloid β Peptide (1–40) with Glycosaminoglycan Model Polymers
Authors: Miura Yoshiko , Mizuno Hikaru
Published: August 2010

We synthesized a novel glycopolymer library with 6-sulfo-GlcNAc and glucuronic acid (GlcA) based on the structure of glycosaminoglycans. The molecular weights of the polymers were controlled via living radical polymerization. The interactions of Aβ(1–40) with glycopolymers were analyzed by inhibition activity of protein aggregation using ThT fluorescence assay, atomic force microscopy observation, and CD spectra. The inhibition activity of Aβ was much affected by the sugar structure and molecular weight of the polymer. The glycopolymers carrying 6-sulfo-GlcNAc showed inhibition activity toward Aβ aggregate, and those with 6-suflo-GlcNAc and GlcA showed the strong inhibition activity. The glycopolymer libraries yielded valuable information about Aβ aggregate with glycosaminoglycans.
Spotting the pantomime villain: do the usual approaches correctly indicate when waiting times got shorter?
Authors: Armstrong Paul W
Published: August 2010

To assess whether changes in length of wait are correlated (directly) with changes in size of list, i.e. whether census-, event- and enrolment-based estimates of the percentage that waited 0–2 months are valid measures. EyeNet Sweden supplied dates of extraction and enrolment for 1,061,246 cataracts extracted between 1992 and 2009 inclusive. Changes in size of list were calculated as enrolments minus extractions. Fifty-nine times out of 62 the enrolment-based measure reported an increase in length of wait when size of list increased or a decrease in length when size decreased ( LB = 90%, 95% confidence interval = 80–100). But 47 times out of 62 the event-based measure reported a decrease in length of wait when size of list increased, or an increase in length when size decreased ( LB = 40%, 95% confidence interval = 6–74). The census-based measure did likewise 34 times out of 63 ( LB = 6%). The three approaches gave different results despite using the same combination of cohorts and categories, the same point on the distribution of waits, the same rules about which waits (and which parts of these) count and the same length of follow-up. Census- and event-based measures often concealed the true direction of change in length of wait.
A configurational view of executive selection behaviours: a taxonomy of USA acute care hospitals
Authors: Landry Amy Yarbrough , Hernandez S Robert , Shewchuk Richard M , Garman Andrew N
Published: August 2010

Health-care organizations, particularly hospitals, are among the most complex organizations to manage. However, the executive selection processes these organizations have in place are poorly understood. The purpose of this study is to explore the executive selection processes employed by USA acute care hospitals and discern if such processes are related to environmental, structural and strategic organizational characteristics. We conceptualize this model using a configurational approach. We present an empirically derived taxonomy of hospitals based on executive selection processes, structural and environmental characteristics, and organizational strategy based on the Porter framework. Based on the analyses, three types of hospitals are identified: (1) small, rural, cost leaders with limited selection processes; (2) large, urban, differentiators, with a plan; and (3) small, rural, caught in the middle muddlers.
Rejoinder—Causes and Implications of Some Bidders Not Conforming to the Sealed-Bid Abstraction
Authors: Zeithammer Robert , Adams Christopher
Published: August 2010

This paper presents the authors' rejoinder to Zeithammer and Adams [Zeithammer, R., C. Adams. 2010. The sealed-bid abstraction in online auctions. Marketing Sci. 29(6) 964–987]. This rejoinder clarifies and qualifies conclusions of the original paper and makes suggestions for fruitful areas of future research. In particular, the original paper shows that bidding style can make a big difference in managerial decisions, but a structural model would be necessary to make confident predictions under different reserve prices. The rejoinder also clarifies the interpretation of feedback as a measure of bidder experience, and the relationship between bidder experience and bidding style.
Infliximab-Induced Lichen Planopilaris
Authors: Fernández-Torres Rosa , Paradela Sabela , Valbuena Luis , Fonseca Eduardo
Published: August 2010

Objective:

To report a case of lichen planopilaris in a patient treated with infliximab for longstanding refractory psoriasis.

Case Summary:

A 37-year-old man with recalcitrant plaque psoriasis was being treated with infliximab at a dosage of 5 mg/kg every 8 weeks, with good response. However, 11 months later the patient developed follicular keratotic papulo-pustules, perifollicular erythema, and scaling, with progressive hair toss of the frontal and parietal regions of the scalp and eyebrows. A skin biopsy from a representative lesion was consistent with the diagnosis of lichen planopilaris.

Discussion:

Anti-tumor necrosis factor (TNF) agents have been associated with numerous cutaneous adverse events. Lichenoid reactions are uncommon but are an emerging cutaneous adverse effect. At least 13 cases of these eruptions have been recently described. Although lichenoid reactions in patients treated with TNF-α inhibitors may be clinically very diverse, we have found no previously reported cases of lichen planopilaris induced by these agents. An objective causality assessment revealed that the adverse event was probable.

Conclusions:

Since anti-TNF agents are being used for a rapidly expanding number of rheumatic, digestive, and dermatologie diseases, it is expected that lichenoid eruptions and other skin toxicities are likely to be seen with increasing frequency in clinical practice.
Intravenous to Oral Conversion of Antihypertensives: A Toolkit for Guideline Development
Authors: Dasta Joseph F , Boucher Bradley A , Brophy Gretchen M , Cohen Henry , Hassan Erkan , MacLaren Robert , Muzykovsky Karina , Martin Steven J , Pass Steven E , Seybert Amy L
Published: August 2010

Objective:

To provide a toolkit of information for hospitals to use in developing intravenous to oral conversion protocols for antihypertensives.

Data Sources:

Articles describing intravenous to oral conversion protocols for any therapeutic category were identified in an English-language MEDLINE search (1990-April 2010) using a wide variety of MeSH terms. References from selected articles were reviewed for additional material.

Study Selection and Data Extraction:

Experimental and observational English-language studies and review articles that focused on oral transition of intravenous drugs were selected.

Data Synthesis:

Most of the literature on conversion from intravenous to oral formulations involves antimicrobials. There is considerable evidence documenting reduced costs and improved patient flow through the health-care system following implementing these protocols with drugs like antimicrobials, histamine-2 receptor antagonists, and proton pump inhibitors. Although antihypertensives have not been studied, principles and implementation strategies used for other drug classes can be applied to antihypertensives. Guidance is provided on framing the problem, issues surrounding oral absorption principles, information pertaining to oral conversion in specific disease slates, and implementation and documentation strategies. Detailed tables of oral and intravenous antihypertensives are provided.

Conclusions:

We recommend that hospitals consider developing protocols on conversion of intravenous to oral antihypertensives in an attempt to reduce unnecessarily prolonged intravenous therapy. Information contained in this article can be used as a toolkit to select information specific to the characteristics of individual health-care systems.
Predictors of Nonadherence to Statins: A Systematic Review and Meta-Analysis
Authors: Mann Devin M , Woodward Mark , Muntner Paul , Falzon Louise , Kronish Ian
Published: August 2010

Background:

Nonadherence to statins limits the benefits of this common drug class. Individual studies assessing predictors of nonadherence haue produced inconsistent results.

Objective:

To identify reliable predictors of nonadherence to statins through systematic review and meta-analysis.

Methods:

Multiple databases, including MEDLINE, EMBASE, and PsycINFO, were searched (from inception through February 2009) to identify studies that evaluated predictors of nonadherence to statins. Studies were selected using a priori defined criteria, and each study was reviewed by 2 authors who abstracted data on study characteristics and outcomes. Relative risks were then pooled, using an inverse-variance weighted random-effects model.

Results:

Twenty-two cohort studies met inclusion criteria. Age had a U-shaped association with adherence; the oldest (≥70 years) and youngest (<50 years) subjects had lower adherence than the middle-aged (50-69 years) subjects. Women and patients with lower incomes were more likely to be nonadherent than were men (odds of nonadherence 1.07; 95% CI 1.04 to 1.11) and those with higher incomes (odds of nonadherence 1.18:95% CI 1.10 to 1.28), respectively. A history of cardiovascular disease predicted better adherence to statins (odds of nonadherence 0.68; 95% CI 0.66 to 0.78). Similarly, a diagnosis of hypertension or diabetes was associated with better adherence. Although there were too few studies for quantitative pooling, increased testing of lipid levels and lower out-of-pocket costs appeared to be associated with better adherence. There was substantial (l2 range 68.7-96.3%) heterogeneity between studies across factors.

Conclusions:

Several sociodemographic, medical, and health-care utilization characteristics are associated with statin nonadherence. These factors may be useful guides for targeting statin adherence interventions.
Health-Care Reform 2010: How Will It Impact You and Your Practice?
Authors: Matzke Gary R , Ross Leigh Ann
Published: August 2010

There are several transformative features of the 2 landmark health-care reform laws passed by the Congress and signed into law by the President in March. The most critical elements that will impact pharmacists and patients are categorized into 6 key areas in this commentary: health insurance reform; improvements in Medicare and Medicaid; pharmacy practice expansion; health professions education and workforce initiatives; prevention and wellness; and enhanced access to affordable medications. The relevant features of these new opportunities are presented and the implications for pharmacists and their patients are discussed.
Patient Misidentifications Caused by Errors in Standard Bar Code Technology
Authors: Snyder Marion L , Carter Alexis , Jenkins Karen , Fantz Corinne R
Published: August 2010

BACKGROUND

Bar code technology has decreased transcription errors in many healthcare applications. However, we have found that linear bar code identification methods are not failsafe. In this study, we sought to identify the sources of bar code decoding errors that generated incorrect patient identifiers when bar codes were scanned for point-of-care glucose testing and to develop solutions to prevent their occurrence.

METHODS

We identified misread wristband bar codes, removed them from service, and rescanned them by using 5 different scanner models. Bar codes were reprinted in pristine condition for use as controls. We determined error rates for each bar code–scanner pair and manually calculated internal bar code data integrity checks.

RESULTS

As many as 3 incorrect patient identifiers were generated from a single bar code. Minor bar code imperfections, failure to control for bar code scanner resolution requirements, and less than optimal printed bar code orientation were confirmed as sources of these errors. Of the scanner models tested, the Roche ACCU-CHEK® glucometer had the highest error rate. The internal data integrity check system did not detect these errors.

CONCLUSIONS

Bar code–related patient misidentifications can occur. In the worst case, misidentified patient results could have been transmitted to the incorrect patient medical record. This report has profound implications not only for point-of-care testing but also for bar coded medication administration, transfusion recipient certification systems, and other areas where patient misidentifications can be life-threatening. Careful control of bar code scanning and printing equipment specifications will minimize this threat to patient safety. Ultimately, healthcare device manufacturers should adopt more robust and higher fidelity alternatives to linear bar code symbologies.
Preparing Very Loose Granular Triaxial Specimens by Ex Situ Freezing
Authors: Graham David S. , Elton David
Published: August 2010

Ex situ soil freezing can be used to prepare very loose cohesionless triaxial specimens that can be handled, stored, and transported. This paper describes two freezing techniques, freezing with cold air in a freezer and freezing with liquid nitrogen. These methods are used to prepare very loose saturated Ottawa sand specimens. Special equipment and techniques used for each method are described. The advantages and disadvantages of both methods and the effectiveness of the efforts to minimize disturbance due to volume changes during freezing are discussed. Properties of specimens prepared using each method are presented. The results of 16 consolidated undrained triaxial shear tests are presented. The freezing method affects the amount of volume change during freezing but does not significantly affect the effective angle of internal friction.
Laboratory Investigation of Fatigue Characteristics of Rubberized Asphalt Mixtures Containing Warm Asphalt Additives at a Low Temperature
Authors: Xiao Feipeng , Zhao Wenbin , Amirkhanian Serji N.
Published: August 2010

The fatigue life of an asphalt pavement is directly related to various factors of a typical warm mix asphalt (WMA) mixture. Improving the understanding of the fatigue behavior of the rubberized WMA mixtures is helpful in recycling the scrap tires and saving energy. This study explores the utilization of the conventional fatigue analysis approach in investigating the cumulative dissipated energy, stiffness, and fatigue life of rubberized asphalt concrete mixtures containing WMA additives. The fatigue beams were made with one rubber type (−40 mesh ambient crumb rubber), two aggregate sources, two WMA additives (Asphamin and Sasobit), and tested at 5°C. The test results indicated that the addition of crumb rubber and WMA additive not only reduced the mixing and compaction temperatures of rubberized asphalt mixtures offset by crumb rubber but also slightly extended the long-term performance of pavement when compared with conventional asphalt mixtures.
Propriedades mecânicas de peças com dimensões estruturais de Pinus spp: correlação entre resistência à tração e classificação visual
Authors: Fiorelli Juliano , Dias Antônio Alves , Coiado Bruno
Published: August 2010

A redução da disponibilidade de espécies de madeiras nativas e seus efeitos na economia, associada ao fortalecimento dos conceitos de preservação ambiental, criou a necessidade de desenvolvimento de alternativas viáveis para utilização racional de espécies de reflorestamento. E uma das opções é a realização de classificação visual das peças. Autores de trabalhos desenvolvidos nessa linha de pesquisa verificaram a adequação das regras de classificação visual do Southern Pine Inspection Bureau (SPIB) dos EUA à madeira de Pinus do Brasil e apresentaram proposta para normalizar o processo de classificação visual dessa madeira. Nessa classificação, os aspectos com maior influência são: presença de nós, desvio de grã em relação ao eixo da peça e densidade de anéis de crescimento. Assim, esta pesquisa apresenta um estudo experimental que consistiu na classificação visual e determinação da resistência à tração de 85 peças de Pinus spp e um estudo teórico, que propôs uma equação para determinar a resistência à tração média de peças estruturais em função da classificação visual. Com este trabalho, foi possível observar a influência dos nós e dos anéis de crescimento sobre a resistência à tração das peças analisadas.
Ecological boundary detection using Bayesian areal wombling
Authors: Fitzpatrick Matthew C. , Preisser Evan L. , Porter Adam , Elkinton Joseph , Waller Lance A. , Carlin Bradley P. , Ellison Aaron M.
Published: August 2010

The study of ecological boundaries and their dynamics is of fundamental importance to much of ecology, biogeography, and evolution. Over the past two decades, boundary analysis (of which wombling is a subfield) has received considerable research attention, resulting in multiple approaches for the quantification of ecological boundaries. Nonetheless, few methods have been developed that can simultaneously (1) analyze spatially homogenized data sets (i.e., areal data in the form of polygons rather than point‐reference data); (2) account for spatial structure in these data and uncertainty associated with them; and (3) objectively assign probabilities to boundaries once detected. Here we describe the application of a Bayesian hierarchical framework for boundary detection developed in public health, which addresses these issues but which has seen limited application in ecology. As examples, we analyze simulated spread data and the historic pattern of spread of an invasive species, the hemlock woolly adelgid (Adelges tsugae), using county‐level summaries of the year of first reported infestation and several covariates potentially important to influencing the observed spread dynamics. Bayesian areal wombling is a promising approach for analyzing ecological boundaries and dynamics related to changes in the distributions of native and invasive species.
Community composition and consumer identity determine the effect of resource species diversity on rates of consumption
Authors: Narwani Anita , Mazumder Asit
Published: August 2010

The effect of species diversity on ecosystem function is commonly studied within a single trophic level, but less is known about how resource diversity affects species interactions between trophic levels. We conducted a grazing experiment to determine how resource species diversity affects rates of consumption by three species of freshwater zooplankton consumers. We measured the effect of resource diversity on rates of consumption for several resource community compositions. These compositions varied in terms of palatability for the consumers. The effect of resource diversity on consumption rates depended on the diet breadth of the consumer species (from specialist to generalist) and the community composition of resources. Overall, high resource diversity commonly caused a decline in consumption rates of consumers. The most selective grazer showed reduced consumption for nearly all community compositions, whereas the most generalist grazer showed accelerated consumption when all resource species were palatable. Our results demonstrate that resource species diversity can modulate rates of consumption through the action of multiple different mechanisms.
Souring Remediation by Field-wide Nitrate Injection in an Alberta Oil Field
Authors: Grigoryan A. , Lambo A. , Lin S. , Cornish S.L. , Jack T.R. , Voordouw G.
Published: August 2010

When oil is produced by water injection, sulphide formation (souring) can be stimulated. Souring is often caused by sulphate-reducing bacteria (SRB) which oxidize organic carbon (oil organics) with sulphate in the injection water to CO2 and sulphide. As a result, H2S concentrations in the produced water, oil and gas gradually increase. A consequence can be that the piping infrastructure must be redesigned from sweet to sour service. A relatively novel biotechnology aimed to remedy souring is to add nitrate to the injection water. Nitrate tracks the injection water effectively and its cost allows continuous and field-wide treatment. In a field-wide nitrate injection, the injection water (approximately 3,500 m3/day) was amended continuously with 2.4 mM (150 ppm) nitrate. Three points in the injection water system and 12 production wells were monitored by sampling every 2 to 3 weeks. The concentrations of sulphide, sulphate, nitrate, nitrite and ammonia in injection and produced waters were determined, as well as the activities of nitrate-reducing bacteria (NRB). Field-wide nitrate injection gave a 70% drop of aqueous sulphide within the first 5 weeks, after which the concentration recovered somewhat for the next 20 weeks. The activity of NRB increased throughout this period, indicating the possibility of further decreases in souring in the future.

Introduction

Microbial production of sulphide by sulphate-reducing bacteria (SRB) in oil reservoirs (i.e. souring) often occurs during secondary oil recovery processes when water is injected to maintain reservoir pressure. Souring is largely perceived to have negative effects because dissolved sulphide (HS−) and precipitated metal sulphides (e.g. FeS) are corrosive towards metal pipes and equipment. Injection of suspended metal sulphides may decrease reservoir injectivity by plugging zones near the injection wellbore, decreasing oil production. Suspended metal sulphides also stabilize oil-water emulsions preventing effective separation of produced water and oil. Hence, souring is highly undesirable from a business and operating point of view, especially when the original facilities were not designed to handle sour production. Souring gives rise to safety concerns regarding the exposure of workers in the field to released hydrogen sulphide and to complaints about odours from surface rights owners and, in urban settings, over the threat to real estate values of a sour service operation on or near residential property.
Foam Mobility Control for Surfactant Enhanced Oil Recovery
Authors: Li Robert Feng , Yan Wei , Liu Shunhua , Hirasaki George J. , Miller Clarence A.
Published: August 2010

Foam generated in situ by surfactant-alternating-gas (SAG) injection is demonstrated as a substitute for polymer drive in the alkaline/surfactant/polymer (ASP) enhanced-oil-recovery (EOR) process. Foam is also effective in a similar process for a 266-cp crude oil, even though the system did not have enough polymer for favorable mobility control. Foam is shown to enhance sweep efficiency greatly in a layered sandpack with a 19:1 permeability ratio. Foam diverted surfactant solution from the high-permeability layer to the low-permeability layer. Ahead of the foam front, liquid in the low-permeability layer crossflowed into the high-permeability layer. A layered system with a 19:1 permeability contrast could be completely swept in 1.3 total pore volumes (TPV) with foam, while waterflood required 8 pore volumes (PV).
Slickwater Fracturing: Food for Thought
Authors: Palisch T.T.. T. , Vincent M.C.. C. , Handren P.J.. J.
Published: August 2010

The evolution of fracturing technology has provided the industry with numerous advances, ranging from sophisticated fluid systems to tip-screenout designs to propagation modeling. Interestingly, these advances typically have focused on conventional designs that use a crosslinked-fluid system. However, as the development of unconventional (e.g., tight gas, shales, coalbed methane) or underpressured reservoirs has increased, so has the demand for innovative hydraulic-fracture designs. The most recent of these design changes has been the popular method of placing proppant with slickwater, linear gel, or hybrid treatments.

Although our industry has significant expertise in fracture design, most of our experience has been in conventional crosslinked-fluid systems. However, there are many aspects of crosslinked-fluid design that either do not apply to slickwater treatments or, in some cases, are contrary to the requirements of slickwater treatments.

This paper will begin by reviewing the motivation, benefits, and concerns with slickwater fracturing and discuss why this seemingly old method has regained popularity over conventional crosslinked designs in many reservoirs. In addition, the authors will detail some of the important theories related to slickwater fracturing, including fracture width and complexity, proppant transport and settling, and conductivity requirements. In each scenario, emphasis will be placed on the different strategy employed compared to crosslinked-fluid designs, and the mistakes or misunderstandings that are frequently made will be highlighted.

Where appropriate, laboratory testing, field measurements, reference material, and other resources are presented to support the observations made by the authors. This paper will serve as a resource to any engineer or technician who is designing/pumping slickwater fracs, or who is considering this technology for potential application. By applying the concepts presented in this paper, engineers will be able to appropriately evaluate the potential benefits of using this technique in their completions, as well as draw on the experiences of others to take full advantage of this technology.
Dynamic Pore-Network Simulator for Modeling Buoyancy-Driven Migration During Depressurization of Oil-Saturated Systems
Authors: Ezeuko C.C.. C. , McDougall S.R.. R. , Bondino I.. , Hamon G..
Published: August 2010

A number of vertically oriented heavy- and light-oil-depletion experiments have been conducted in recent years in an attempt to investigate the effect of gravitational forces on gas evolution during solution-gas drive. Although some experimental results indirectly suggest the occurrence of gas migration during these tests (especially at slow depletion rates), a major limitation of such an interpretation is the difficulty in visualizing the process in reservoir-rock samples. In contrast, experimental observations using transparent glass models have proved invaluable in this context and provide a sound physical basis for modeling gravitational gas migration in gas/oil systems. However, the experimental observations often exhibit somewhat contradictory trends—some studies showing dispersed gas migration, while others describe fingered, channelized flow—and, to date, there appears to have been little systematic effort toward modeling the wide range of behaviors seen in or inferred from laboratory tests.

To this end, we present a new pore-network simulator that is capable of modeling the time-dependent migration of growing gas structures. Multiple pore-filling events are modeled dynamically with interface tracking allowing the full range of migratory behaviors to be reproduced, including braided migration (i.e., discontinuous flow of gas through narrow channels) and discontinuous dispersed flow. Simulation results are compared with experiments and are found to be in excellent agreement. Moreover, simulation results clearly show that a number of network and fluid parameters interact in a rather complex manner and, as a consequence, the competition between capillarity and buoyancy produces different gas-evolution patterns during pressure depletion. The implications of evolution regime on recovery from gas/oil systems undergoing depressurization are discussed extensively.
Effects of Friction on Post-Buckling Behavior and Axial Load Transfer in a Horizontal Well
Authors: Gao Guohua , Miska Stefan
Published: August 2010

In this paper, the buckling equation and natural boundary conditions are derived with the aid of calculus of variations. The natural and geometric boundary conditions are used to determine the proper solution that represents the post-buckling configuration. Effects of friction and boundary conditions on the critical load of helical buckling are investigated. Theoretical results show that the effect of boundary conditions on helical buckling becomes negligible for a long pipe with dimensionless length greater than 5π Velocity analysis shows that lateral friction becomes dominant at the instant of buckling initiation. Thus, friction can increase the critical load of helical buckling significantly. However, once buckling is initiated, axial velocity becomes dominant again and lateral friction becomes negligible for post-buckling behavior and axial-load-transfer analysis. Consequently, it is possible to seek an analytical solution for the buckling equation. Analytical solutions for both sinusoidal and helical post-buckling configurations are derived, and a practical procedure for modeling of axial load transfer is proposed. To verify the proposed model and analytical results, the authors also conducted experimental studies. Experimental results support the proposed solutions.
Transport of CO2-Foaming Agents During CO2-Foam Processes in Fractured Chalk Rock
Authors: Zuta John , Fjelde Ingebret
Published: August 2010

The coinjection of carbon dioxide (CO2) and a CO2-foaming agent to form stable CO2 foam has been found to improve the sweep efficiency during CO2-foam processes in carbonate reservoirs. However, only a few studies of CO2-foam transport in fractured rock have been reported. In fractured chalk reservoirs with low matrix permeability, the aqueous CO2-foaming-agent solution will flow mainly through the fractures. The total retention of the CO2-foaming agent in the reservoir will depend on how much of the matrix is contacted by the CO2-foaming-agent solution during the project period and, therefore, on its transport rate into the matrix.

This paper presents results from a series of static and flowthrough experiments carried out to investigate the transport and retention phenomena of CO2-foaming agents in fractured chalk models at 55°C. Fractured chalk models with 100% water-saturation and residual-oil saturation after waterflooding were used. In the static experiments, the fractured model was created by transferring core plugs with different diameters into steel cells with an annulus space around the plugs. The fracture volume was filled with foaming-agent solutions with different initial concentrations. The experiments were carried out in parallel, with liquid samples regularly taken out from the fracture above the plugs and analyzed for the foaming-agent concentration. The experiments were monitored until the concentrations in the fractures reached a plateau.

At specific and constant concentrations of the foaming agent in the fractures, the plugs were demounted and samples drilled out along the whole lengths of the plugs from the outer, middle, and center portions. These samples were analyzed for foaming-agent concentration to determine how much of it had penetrated the matrix.

Results indicate that the transport of the foaming-agent decreases toward the center of the plugs with 100% water-saturation and residual-oil saturation after waterflooding. Modeling of the static experiments using the Computer Modelling Group (CMG)'s commercial reservoir simulator STARS was also carried out to determine the transport rate for the foaming agent. A good history match between experimental and modeling results was obtained. In the flow-through experiments, the fractured model was created by drilling a concentric hole through the center of the plug. The hole, simulating an artificial fracture, was filled with glass beads of different dimensions. Fractured models with different effective permeability were flooded with equal volumes of the foaming-agent solution. Results show that the transport of CO2-foaming agent into the matrix is slower in the fractured models than in the homogeneous models with viscous flooding of the rock.