bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypoxia, the HIF pathway and neutrophilic inflammatory responses
Authors: Thompson A.A. Roger , Binham John , Plant Tracie , Whyte Moira K.B. , Walmsley Sarah R.
Published: January 2013

Many inflammatory diseases are characterised by persistent and inappropriate neutrophil activation, systemic or localised hypoxia, and bacterial colonisation. Hypoxia represents an important regulator of inflammatory responses because it inhibits neutrophil apoptosis, a process central to the timely resolution of inflammation. Progress in understanding how cells respond to hypoxia has led to the identification of hypoxia-inducible transcription factors (HIFs) and their hydroxylation by the prolyl hydroxylase enzymes. There is now a significant body of data to support a critical role for this HIF pathway in regulating neutrophil function. Moreover, manipulations of specific components of this pathway have very divergent effects on myeloid cell function. In this review, we will discuss the role individual members of the HIF pathway play in regulating key neutrophil functions and the implications this has for the development of effective therapeutic strategies that selectively target inappropriate neutrophil persistence while maintaining a fully competent immune response.
nanoHUB.org: cloud-based services for nanoscale modeling, simulation, and education
Authors: Madhavan Krishna , Zentner Lynn , Farnsworth Victoria , Shivarajapura Swaroop , Zentner Michael , Denny Nathan , Klimeck Gerhard
Published: January 2013

nanoHUB.org is arguably one of the most successful science gateways funded by the National Science Foundation (NSF). It is the cyberinfrastructure that supports the Network for Computational Nanotechnology (NCN), currently serving over 240,000 users annually in 172 countries worldwide. It features a range of resources including seminars, online courses, short courses, full-fledged tool-powered curricula, and over 260 online simulations and modeling tools. nanoHUB functions as a scientific cloud where users cannot only design and run their tools but also provide a worldwide audience access to these tools with no installation or minimal infrastructural requirements on the users’ part.
Who Gets the Benefit of the Doubt From Uncertainty?
Authors: Hall John R.
Published: January 2013

Codes, standards and regulations require compliance with criteria stated as the results of tests or calculations. These results have associated uncertainty. This paper discusses different approaches to the use of uncertainty in the determination of compliance. In particular, most discussion addresses the many ways in which the decision-making protocol, intended to result in a determination of compliance, may shift the benefit of the doubt of the uncertainty between different interested parties.
Measurement Uncertainty in Fire Tests— A Fire Laboratory Point of View
Authors: Trevino Javier O. , Curkeet Rick
Published: January 2013

Since the adoption of ISO/IEC 17025, testing laboratories have been required to perform Measurement Uncertainty analysis for the tests within their scope. Four points of recurring debate are discussed: (1) The variability in fire test results due to unforeseen/uncontrolled variables is generally far greater than the measurement uncertainty of the result. (2) It is important not to confuse “measurement uncertainty” (MU) with “precision” of results. MU has a very specific meaning as used in ISO/IEC 17025, ISO/IEC Guide 98-3 Guide to the Expression of Uncertainty in Measurement (GUM) and ISO Guide 99 International vocabulary of metrology—Basic and general concepts and associated terms (VIM). (3) An uncertainty result is not used to justify passing or failing a product with results very near the pass/fail limit. Where the measured result is subject to a measurement uncertainty evaluation and reporting, compliance limits may or may not require extending the test result by the MU value in making a compliance determination. (4) ISO/IEC 17025 specifically exempts standards that specify limits on sources of uncertainty and specify the form of reporting from a required MU statement. This makes uncertainty estimates inapplicable to those fire tests.
Bench Tests for Characterizing the Thermophysical Properties of Type X Special Fire Resistant Gypsum Board Exposed to Fire
Authors: Shipp Paul H. , Yu Qiang
Published: January 2013

ASTM C1396 Standard Specification for Gypsum Board defines type X special fire resistant gypsum board on the basis of the fire resistance of a load bearing wood framed gypsum partition tested in accordance with ASTM E119 Standard Test Methods for Fire Tests of Building Construction and Materials. Monitoring individual product performance in a wall system fire test presents serious challenges to the manufacturing facility. The expense and complexity of operating an ASTM E119 wall furnace makes it impossible for plants to run the defining test on site. In addition, many factors influence the outcome of a fire resistance test making it difficult to assess the performance of the gypsum board independently of other wall system and laboratory influences. In 2003 the Gypsum Association formed an ad hoc Product Standard Task Group in an attempt to develop an improved definition of type X gypsum board. The new definition had to be equivalent to the current ASTM C1396 specification but based on bench scale tests of the high temperature thermophysical properties of type X gypsum board alone. The tests must also be suitable for use as in-plant quality assurance procedures. A suite of three tests resulted. Their development and correlation to the ASTM E119 test has been documented by the authors in an earlier paper. An analysis of the precision of these three test methods is presented here.
Measurement Uncertainty and Statistical Process Control for the Steiner Tunnel (UL 723, ASTM E84)
Authors: Resing John V. , Ghi Pravinray D. , Sloan Dwayne E. , Laymon Rall K.
Published: January 2013

In the United States, the Steiner Tunnel (UL 723 [2008, “Test for Surface Burning Characteristics of Building Materials,” Ninth Edition, Underwriters Laboratories Inc., Northbrook, IL], ASTM E84-10 [2010, “Standard Test Method for Surface Burning Characteristics of Building Materials,” Annual Book of ASTM Standards, Vol. 4.07, ASTM International, West Conshohocken, PA.]) is an important fire test apparatus used by the building codes to assess the flammability and smoke generation characteristics of building products (e.g., insulation, sheathing materials, foamed plastics, wood-based products). This paper examines how various tools and methodologies can be used to quantify, improve, and control measurement uncertainty in fire tests, such as the ASTM E84 tunnel test. This paper also assesses uncertainty in the Steiner Tunnel using both a Gage Repeatability and Reproducibility (Gage r&R) study and historical results for reference materials. The improvements discussed were achieved by using a widely known Lean/Sigma principle—the define, measure, analyze, improve, control (DMAIC) method. Benefits derived from the DMAIC method include: (i) an improved understanding and control of the sources of variation; (ii) the development of process control charts to monitor Steiner Tunnel performance; and (iii) a reduced need for calibration and re-verification of Steiner Tunnel performance. The Gage r&R results show that the major contributor to uncertainty in flame spread and smoke developed results is primarily due to the performance difference in the test samples, and not due to the measurement device or the person conducting the test. The uncertainty, in the form of the standard deviation, is also shown in the results of each of the materials tested in the study. Monthly data for the historical reference material, red oak, and a proposed reference material, heptane, are shown to demonstrate stability of the measurement system over time. The heptane test is presented to help measure and reduce uncertainty of the smoke measurement in the Steiner Tunnel.
Uncertainty in Fire Protection Engineering Design
Authors: Hurley Morgan J.
Published: January 2013

The SFPE Engineering Guide to Performance-Based Fire Protection defines “uncertainty” as “the amount by which an observed or calculated value might differ from the true value.” In engineering, there are two types of uncertainly: epistemic and aleatory. Epistemic uncertainty is uncertainty due to lack of (complete) knowledge. Aleatory uncertainty is uncertainty due to random variation. At present, no single, widely accepted methodology exists for dealing with uncertainty in fire protection engineering. This paper reviews the sources of uncertainty that are present in fire protection engineering and methods that are used to address them.
Hydrothermal Emergence Model for Ripgut Brome (Bromus diandrus)
Authors: García Addy L. , Recasens Jordi , Forcella Frank , Torra Joel , Royo-Esnal Aritz
Published: January 2013

A model that describes the emergence of ripgut brome was developed using a two-season data set from a no-tilled field in northeastern Spain. The relationship between cumulative emergence and hydrothermal time (HTT) was described by a sigmoid growth function (Chapman). HTT was calculated with a set of water potentials and temperatures, iteratively used, to determine the base water potential and base temperature. Emergence of ripgut brome was well described with a Chapman function. The newly-developed function was validated with four sets of data, two of them belonging to a third season in the same field and the other two coming from independent data from Southern Spain. The model also successfully described the emergence in different field management and tillage systems. This model may be useful for predicting ripgut brome emergence in winter cereal fields of semiarid Mediterranean regions.
Increased Purple Nutsedge (Cyperus rotundus) Tuber Sprouting with Diurnally Fluctuating Temperatures
Authors: Wallace Rebekah D. , Grey Timothy L. , Webster Theodore M. , Vencill William K.
Published: January 2013

Purple nutsedge is among the most troublesome weeds of vegetables in the Southeast US and a substantial impediment in the search for methyl bromide alternatives. Greater understanding of the environmental cues that regulate tuber sprouting may assist in improved nutsedge management. Experiments were conducted to evaluate the effect of diurnal temperature variation on sprouting of purple nutsedge tubers. Two temperature regimes were evaluated: the first averaged 28 C, with daily fluctuations ranging from 0 to 19.5 C; the second temperature regime averaged 16 C, with daily fluctuations ranging from 0 to 18.5 C. When average temperature was 28 C, cumulative tuber sprouting ranged from 88 to 92%, with no detectable differences among diurnal fluctuations. The high average temperature in the first study may have negated any type of enforced sprouting suppression. However, when average temperature was lowered to 16 C (simulating early spring diurnal fluctuations under polyethylene mulch), there was a positive linear correlation between maximum tuber sprouting and temperature variation. With an average temperature of 16 C, the absence of temperature variation resulted in 52% purple nutsedge sprouting, while 87% sprouting occurred when daily temperature varied 18.5 C at the same average temperature. The use of various types of mulching material can affect average soil temperatures and diurnal variations, potentially shifting nutsedge emergence. Further studies are needed to determine if these data on tuber sprouting in response to alternating temperatures can facilitate more efficient weed management.
Competition between ACCase-Inhibitor Resistant and Susceptible Sterile Wild Oat (Avena sterilis) Biotypes
Authors: Travlos Ilias S.
Published: January 2013

Studies were conducted to determine the growth, fecundity, and competitive ability of an acetyl-CoA carboxylase (ACCase)–inhibitor resistant (R) sterile wild oat biotype compared with a susceptible (S) biotype. Seed germination studies indicated that there were no differences in seed germination and seedling vigor between R and S biotypes at any temperature regime. R and S biotypes were grown under noncompetitive and competitive arrangement in the greenhouse. Under noncompetitive greenhouse conditions, growth of the R biotype was similar to that of the S biotype on the basis of plant height, canopy area, and plant biomass. Seed production and weight of R and S plants were also at the same levels. Furthermore, relative competitiveness among the R and S sterile wild oat biotypes was investigated by means of replacement series experiments. The R and S biotypes were compared under seven mixture proportions (6 : 0, 5 : 1, 4 : 2, 3 : 3, 2 : 4, 1 : 5, and 0 : 6). No significant differences in competitive ability were observed between R and S biotypes on the basis of plant height, canopy area, or plant biomass. In most cases, relative crowding coefficient (RCC) values at 20, 60, and 100 d after transplanting (DAT) were close to one, indicating equal competitiveness between the R and S biotypes of wild oat used in this competitive study. However, in some cases, the RCC value was 1.31 for plant height, evident of a slight competitive advantage for the R biotype at 100 DAT. In general, ACCase-inhibitor R and S sterile wild oat biotypes were equally competitive, clearly without any growth penalty for R plants in either noncompetitive or competitive conditions.
Mechanical Termination of Diverse Cover Crop Mixtures for Improved Weed Suppression in Organic Cropping Systems
Authors: Wortman Sam E. , Francis Charles A. , Bernards Mark A. , Blankenship Erin E. , Lindquist John L.
Published: January 2013

Cover crops can provide many benefits in agroecosystems, including the opportunity for improved weed control. However, the weed suppressive potential of cover crops may depend on the species (or mixture of species) chosen, and the method of cover crop termination and residue management. The objective of this study was to determine the effects of cover crop mixture and mechanical termination method on weed biomass and density, and relative crop yield in an organic cropping system. A field experiment was conducted from 2009 to 2011 near Mead, NE, where spring-sown mixtures of two, four, six, and eight cover crop species were included in a sunflower–soybean–corn crop rotation. Cover crops were planted in late March, terminated in late May using a field disk or sweep plow undercutter, and main crops were planted within 1 wk of termination. Terminating cover crops with the undercutter consistently reduced early-season grass weed biomass, whereas termination with the field disk typically stimulated grass weed biomass relative to a no cover crop control (NC). The effects of cover crop mixture were not evident in 2009, but the combination of the undercutter and the eight-species mixture reduced early-season weed biomass by 48% relative to the NC treatment in 2010. Cover crops provided less weed control in 2011, where only the combination of the undercutter and the two-species mixture reduced weed biomass (by 31%) relative to the NC treatment. Termination with the undercutter resulted in relative yield increases of 16.6 and 22.7% in corn and soybean, respectively. In contrast, termination with the field disk resulted in a relative yield reduction of 13.6% in soybean. The dominant influence of termination method highlights the importance of appropriate cover crop residue management in maximizing potential agronomic benefits associated with cover crops.
Resistance to Glyphosate in Junglerice (Echinochloa colona) from California
Authors: Alarcón-Reverte Rocío , García Alejandro , Urzúa Jaime , Fischer Albert J.
Published: January 2013

A suspected glyphosate-resistant (R) junglerice population was collected from a glyphosate-R corn field near Durham in northern California where glyphosate had been applied at least twice a year for over 6 yr. Based on the amount of glyphosate required to reduce growth by 50% (ED50), the R population was 6.6 times more R than the susceptible (S) standard population. Based on the glyphosate concentration that inhibits EPSPS by 50% based on shikimate accumulation (I50) in leaf discs, R plants were four times more R than S plants. By 3 d after treatment with 0.42 kg ae ha−1glyphosate, the S population had accumulated approximately five times more shikimate than the R population. No differences in [14C]-glyphosate uptake and translocation were detected between R and S plants. However, partial sequencing of theEPSPSgene revealed a mutation in R plants causing a proline to serine change at EPSPS position 106 (P106S). Our results reveal the first case of a P106S target site mutation associated with glyphosate resistance in junglerice.
A revision of the rare genusCyclolampas(Echinoidea) using morphometrics with description of a new species from the upper Callovian of Burgundy (France)
Authors: Saucede Thomas , Bonnot Alain , Marchand Didier , Courville Philippe
Published: January 2013

The discovery of a new species,Cyclolampas altusnew species in the upper Callovian of Burgundy (France) leads to the systematic revision of the rare echinoid genusCyclolampasPomel, 1883. Two morphometric approaches are used jointly to describe and quantify variations in test shape: the analysis of linear measurements and the Elliptic Fourier shape analysis. Both analyses yield congruent results that highlight the amplitude of within-species variations and quantify the part due to allometry. Along with the description ofC. altus, the systematic position of species formerly assigned to the generaPygorhytisPomel, 1883 andCyclolampasis amended. Previously attributed to the genusPygorhytis,Cyclolampas castanea(Desor, 1858) is reassigned to the genusCyclolampason the base of new observations. Conversely, the examination of the Bajocian speciesPygorhytis kiliani(Lambert, 1909) andPygorhytis gillieroniDesor in Desor and de Loriol, 1872, which were previously assigned toCyclolampasnow supports their taxonomic reassignment to the genusPygorhytis. Finally, the two speciesCyclolampas verneuili(Cotteau, 1870) andCyclolampas cotteauiMintz, 1966 (nomen nudum) are considered junior synonyms of the genus type speciesCyclolampas voltzii(Agassiz, 1839). The questioned origin date of the genus, estimated either to the Bajocian or to the Oxfordian, is now clearly established to be upper Callovian. These new results fit well with the overall scheme of atelostomate echinoid evolution and migration to deep-sea environments during the Middle and Upper Jurassic.
Early Triassic (Spathian) post-extinction microconchids from western Pangea
Authors: Zatoń Michał , Taylor Paul D. , Vinn Olev
Published: January 2013

A new microconchid tentaculitoid,Microconchus utahensisnew species, is described from the Lower Triassic (Spathian) Virgin Formation of two localities (Hurricane Cliffs and Beaver Dam Mountains) near St George, Utah. This small encrusting tubeworm, previously referred to erroneously asSpirorbis, has a laminated shell microstructure containing minute pores (punctae). The population from deeper water facies of the Beaver Dam Mountains is more abundant than that from Hurricane Cliffs and the tubes are significantly larger in size. Although represented by only one species (M. utahensis), microconchids are by far the most dominant component of the otherwise impoverished sclerobiont assemblage of the Virgin Formation, which also includes rare cemented bivalves and probable foraminifers. Whereas the remainder of the Virgin fauna is quite diverse, the low diversity of encrusters suggests a slow recovery from end-Permian mass extinctions. Indeed, more typically Mesozoic sclerobiont assemblages dominated by cyclostome bryozoans and serpulid polychaetes did not appear until the Late Triassic, probably Rhaetian.
Consumer diversity interacts with prey defenses to drive ecosystem function
Authors: Rasher Douglas B. , Hoey Andrew S. , Hay Mark E.
Published: January 2013

Prey traits linking consumer diversity to ecosystem function remain poorly understood. On tropical coral reefs, herbivores promote coral dominance by suppressing competing macroalgae, but the roles of herbivore identity and diversity, macroalgal defenses, and their interactions in affecting reef resilience and function are unclear. We studied adjacent pairs of no‐take marine reserves and fished areas on reefs in Fiji and found that protected reefs supported 7–17× greater biomass, 2–3× higher species richness of herbivorous fishes, and 3–11× more live coral cover than did fished reefs. In contrast, macroalgae were 27–61× more abundant and 3–4× more species‐rich on fished reefs. When we transplanted seven common macroalgae from fished reefs into reserves they were rapidly consumed, suggesting that rates of herbivory (ecosystem functioning) differed inside vs. outside reserves.

We then video‐recorded feeding activity on the same seven macroalgae when transplanted into reserves, and assessed the functional redundancy vs. complementarity of herbivorous fishes consuming these macroalgae. Of 29 species of larger herbivorous fishes on these reefs, only four species accounted for 97% of macroalgal consumption. Two unicornfish consumed a range of brown macroalgae, a parrotfish consumed multiple red algae, and a rabbitfish consumed a green alga, with almost no diet overlap among these groups. The two most chemically rich, allelopathic algae were each consumed by a single, but different, fish species. This striking complementarity resulted from herbivore species differing in their tolerances to macroalgal chemical and structural defenses.

A model of assemblage diet breadth based on our feeding observations predicted that high browser diversity would be required for effective control of macroalgae on Fijian reefs. In support of this model, we observed strong negative relationships between herbivore diversity and macroalgal abundance and diversity across the six study reefs. Our findings indicate that the total diet breadth of the herbivore community and the probability of all macroalgae being removed from reefs by herbivores increases with increasing herbivore diversity, but that a few critical species drive this relationship. Therefore, interactions between algal defenses and herbivore tolerances create an essential role for consumer diversity in the functioning and resilience of coral reefs.
Mother-Perceived Social Capital and Children’s Oral Health and Use of Dental Care in the United States
Authors: Iida Hiroko , Rozier R. Gary
Published: January 2013

Objectives. We examined the association between mother-perceived neighborhood social capital and oral health status and dental care use in US children.

Methods. We analyzed data for 67 388 children whose mothers participated in the 2007 National Survey of Children’s Health. We measured mothers’ perceived social capital with a 4-item social capital index (SCI) that captures reciprocal help, support, and trust in the neighborhood. Dependent variables were mother-perceived ratings of their child’s oral health, unmet dental care needs, and lack of a previous-year preventive dental visit. We performed bivariate and multivariable logistic regression analyses for each outcome.

Results. After we controlled for potential confounders, children of mothers with high (SCI = 5–7) and lower levels (SCI ≥ 8) of social capital were 15% (P = .05) and about 40% (P ≤ .02), respectively, more likely to forgo preventive dental visits than were children of mothers with the highest social capital (SCI = 4). Mothers with the lowest SCI were 79% more likely to report unmet dental care needs for their children than were mothers with highest SCI (P = .01).

Conclusions. A better understanding of social capital’s effects on children’s oral health risks may help address oral health disparities.
The Impact of Functional Health Literacy and Acculturation on the Oral Health Status of Somali Refugees Living in Massachusetts
Authors: Geltman Paul L. , Adams Jo Hunter , Cochran Jennifer , Doros Gheorghe , Rybin Denis , Henshaw Michelle , Barnes Linda L. , Paasche-Orlow Michael
Published: January 2013

Objectives. We assessed the impact of health literacy and acculturation on oral health status of Somali refugees in Massachusetts.

Methods. Between December 2009 and June 2011, we surveyed 439 adult Somalis who had lived in the United States 10 years or less. Assessments included oral examinations with decayed, missing, and filled teeth (DMFT) counts and measurement of spoken English and health literacy. We tested associations with generalized linear regression models.

Results. Participants had means of 1.4 decayed, 2.8 missing, and 1.3 filled teeth. Among participants who had been in the United States 0 to 4 years, lower health literacy scores correlated with lower DMFT (rate ratio [RR] = 0.78; P = .016). Among participants who had been in the country 5 to 10 years, lower literacy scores correlated with higher DMFT (RR = 1.37; P = .012). Literacy was not significantly associated with decayed teeth. Lower literacy scores correlated marginally with lower risk of periodontal disease (odds ratio = 0.22; P = .047).

Conclusions. Worsening oral health of Somali refugees over time may be linked to less access to preventive care and less utilization of beneficial oral hygiene practices.
Individual, Family Background, and Contextual Explanations of Racial and Ethnic Disparities in Youths’ Exposure to Violence
Authors: Zimmerman Gregory M. , Messner Steven F.
Published: January 2013

We used data from the Project on Human Development in Chicago Neighborhoods to examine the extent to which individual, family, and contextual factors account for the differential exposure to violence associated with race/ethnicity among youths. Logistic hierarchical item response models on 2344 individuals nested within 80 neighborhoods revealed that the odds of being exposed to violence were 74% and 112% higher for Hispanics and Blacks, respectively, than for Whites. Appreciable portions of the Hispanic–White gap (33%) and the Black–White gap (53%) were accounted for by family background factors, individual differences, and neighborhood factors. The findings imply that programs aimed at addressing the risk factors for exposure to violence and alleviating the effects of exposure to violence may decrease racial/ethnic disparities in exposure to violence and its consequences.
Characteristics Associated With Awareness, Perceptions, and Use of Electronic Nicotine Delivery Systems Among Young US Midwestern Adults
Authors: Choi Kelvin , Forster Jean
Published: January 2013

Objectives. We assessed the characteristics associated with the awareness, perceptions, and use of electronic nicotine delivery systems (e-cigarettes) among young adults.

Methods. We collected data in 2010–2011 from a cohort of 2624 US Midwestern adults aged 20 to 28 years. We assessed awareness and use of e-cigarettes, perceptions of them as a smoking cessation aid, and beliefs about their harmfulness and addictiveness relative to cigarettes and estimated their associations with demographic characteristics, smoking status, and peer smoking.

Results. Overall, 69.9% of respondents were aware of e-cigarettes, 7.0% had ever used e-cigarettes, and 1.2% had used e-cigarettes in the past 30 days. Men, current and former smokers, and participants who had at least 1 close friend who smoked were more likely to be aware of and to have used e-cigarettes. Among those who were aware of e-cigarettes, 44.5% agreed e-cigarettes can help people quit smoking, 52.8% agreed e-cigarettes are less harmful than cigarettes, and 26.3% agreed e-cigarettes are less addictive than cigarettes.

Conclusions. Health communication interventions to provide correct information about e-cigarettes and regulation of e-cigarette marketing may be effective in reducing young adults’ experimentation with e-cigarettes.
Trends in Mortality Risk by Education Level and Cause of Death Among US White Women From 1986 to 2006
Authors: Montez Jennifer Karas , Zajacova Anna
Published: January 2013

Objectives. To elucidate why the inverse association between education level and mortality risk (the gradient) has increased markedly among White women since the mid-1980s, we identified causes of death for which the gradient increased.

Methods. We used data from the 1986 to 2006 National Health Interview Survey Linked Mortality File on non-Hispanic White women aged 45 to 84 years (n = 230 692). We examined trends in the gradient by cause of death across 4 time periods and 4 education levels using age-standardized death rates.

Results. During 1986 to 2002, the growing gradient for all-cause mortality reflected increasing mortality among low-educated women and declining mortality among college-educated women; during 2003 to 2006 it mainly reflected declining mortality among college-educated women. The gradient increased for heart disease, lung cancer, chronic lower respiratory disease, cerebrovascular disease, diabetes, and Alzheimer’s disease. Lung cancer and chronic lower respiratory disease explained 47% of the overall increase.

Conclusions. Mortality disparities among White women widened across 1986 to 2006 partially because of causes of death for which smoking is a major risk factor. A comprehensive policy framework should address the social conditions that influence smoking among disadvantaged women.
Asylum Seekers, Violence and Health: A Systematic Review of Research in High-Income Host Countries
Authors: Kalt Anne , Hossain Mazeda , Kiss Ligia , Zimmerman Cathy
Published: January 2013

We performed a systematic review of literature on violence and related health concerns among asylum seekers in high-income host countries. We extracted data from 23 peer-reviewed studies.

Prevalence of torture, variably defined, was above 30% across all studies. Torture history in clinic populations correlated with hunger and posttraumatic stress disorder, although in small, nonrepresentative samples. One study observed that previous exposure to interpersonal violence interacted with longer immigration detention periods, resulting in higher depression scores.

Limited evidence suggests that asylum seekers frequently experience violence and health problems, but large-scale studies are needed to inform policies and services for this vulnerable group often at the center of political debate.
The Burden of Influenza B: A Structured Literature Review
Authors: Paul Glezen W. , Schmier Jordana K. , Kuehn Carrie M. , Ryan Kellie J. , Oxford John
Published: January 2013

We reviewed the epidemiology, clinical characteristics, disease severity, and economic burden of influenza B as reported in the peer-reviewed published literature. We used MEDLINE to perform a systematic literature review of peer-reviewed, English-language literature published between 1995 and 2010.

Widely variable frequency data were reported. Clinical presentation of influenza B was similar to that of influenza A, although we observed conflicting reports. Influenza B–specific data on hospitalization rates, length of stay, and economic outcomes were limited but demonstrated that the burden of influenza B can be significant.

The medical literature demonstrates that influenza B can pose a significant burden to the global population. The comprehensiveness and quality of reporting on influenza B, however, could be substantially improved. Few articles described complications. Additional data regarding the incidence, clinical burden, and economic impact of influenza B would augment our understanding of the disease and assist in vaccine development.
The Impact of Increasing Health Insurance Coverage on Disparities in Mortality: Health Care Reform in Colombia, 1998–2007
Authors: Arroyave Ivan , Cardona Doris , Burdorf Alex , Avendano Mauricio
Published: January 2013

Objectives. We examined the impact of expanding health insurance coverage on socioeconomic disparities in total and cardiovascular disease mortality from 1998 to 2007 in Colombia.

Methods. We used Poisson regression to analyze data from mortality registries (633 905 deaths) linked to population census data. We used the relative index of inequality to compare disparities in mortality by education between periods of moderate increase (1998–2002) and accelerated increase (2003–2007) in health insurance coverage.

Results. Disparities in mortality by education widened over time. Among men, the relative index of inequality increased from 2.59 (95% confidence interval [CI] = 2.52, 2.67) in 1998–2002 to 3.07 (95% CI = 2.99, 3.15) in 2003–2007, and among women, from 2.86 (95% CI = 2.77, 2.95) to 3.12 (95% CI = 3.03, 3.21), respectively. Disparities increased yearly by 11% in men and 4% in women in 1998–2002, whereas they increased by 1% in men per year and remained stable among women in 2003–2007.

Conclusions. Mortality disparities widened significantly less during the period of increased health insurance coverage than the period of no coverage change. Although expanding coverage did not eliminate disparities, it may contribute to curbing future widening of disparities.
What “Price” Means When Buying Food: Insights From a Multisite Qualitative Study With Black Americans
Authors: DiSantis Katherine Isselmann , Grier Sonya A. , Odoms-Young Angela , Baskin Monica L. , Carter-Edwards Lori , Young Deborah Rohm , Lassiter Vikki , Kumanyika Shiriki K.
Published: January 2013

Objectives. We explored the role of price in the food purchasing patterns of Black adults and youths.

Methods. We analyzed qualitative data from interviews and focus groups with socioeconomically diverse, primarily female, Black adults or parents (n = 75) and youths (n = 42) in 4 US cities. Interview protocols were locality specific, but all were designed to elicit broad discussion of food marketing variables. We performed a conventional qualitative content analysis by coding and analyzing data from each site to identify common salient themes.

Results. Price emerged as a primary influence on food purchases across all sites. Other value considerations (e.g., convenience, food quality, healthfulness of product, and family preferences) were discussed, providing a more complex picture of how participants considered the price of a product.

Conclusions. Food pricing strategies that encourage consumption of healthful foods may have high relevance for Black persons across income or education levels. Accounting for how price intersects with other value considerations may improve the effectiveness of these strategies.
Reservoir Simulation of Steam Fracturing in Early-Cycle Cyclic Steam Stimulation
Authors: Cokar Marya , Kallos Michael S. , Gates Ian D.
Published: January 2013

In cyclic steam stimulation (CSS), steam is injected above the fracture pressure into the oil-sands reservoir. In early cycles, the injected steam fractures the reservoir, creating a relatively thin dilated zone that allows rapid distribution of heat within the reservoir without excessive displacement of oil from the neighborhood of the wellbore. Numerical reservoir-simulation models of CSS that deal with the fracturing process have difficulty simultaneously capturing flowing bottomhole-pressure (BHP) behavior and steam injection rate. In this research, coupled reservoir-simulation (flow and heat transfer) and geomechanics models are investigated to model dynamic fracturing during the first cycle of CSS in an oil-sands reservoir. In Alberta, Canada, in terms of volumetric production rate, CSS is the largest thermal recovery technology for bitumen production, with production rates equal to approximately 1.3 million B/D in 2008. The average recovery factor from CSS is between 25 and 28% at the economic end of the process. This implies that the majority of bitumen remains in the ground. Because the mobility of the bitumen depends strongly on temperature, the performance of CSS is intimately linked to steam conformance in the reservoir, which is largely established during steam fracturing of the reservoir in the early cycles of the process. Thus, a fundamental understanding of the flow and geomechanical aspects of early-cycle CSS is critical. A detailed thermal reservoir-simulation model, including dilation and dynamic fracturing, was developed, with the use of a commercially available thermal reservoir simulator, to understand their effects on BHP and injection rate. The results demonstrate that geomechanics must be included to accurately model CSS. The results also suggest that the reservoir dilates during steam injection as the result of increases in reservoir temperature, which lead to thermal dilation and higher pore pressure.
Surge-and-Swab Pressure Predictions for Yield-Power-Law Drilling Fluids
Authors: Crespo Freddy , Ahmed Ramadan , Enfis Majed , Saasen Arild , Amani Mahmood
Published: January 2013

Surge and swab pressures have been known to cause formation fracture, lost circulation, and well-control problems. Accurate prediction of these pressures is crucially important in estimating the maximum tripping speeds to keep the wellbore pressure within specified limits of the pore and fracture pressures. It also plays a major role in running casings, particularly with narrow annular clearances. Existing surge/swab models are based on Bingham plastic (BP) and power-law (PL) fluid rheology models. However, in most cases, these models cannot adequately describe the flow behavior of drilling fluids.

This paper presents a new steady-state model that can account for fluid and formation compressibility and pipe elasticity. For the closed-ended pipe, the model is cast into a simplified model to predict pressure surge in a more convenient way. The steady-state laminar-flow equation is solved for narrow slot geometry to approximate the flow in a concentric annulus with inner-pipe axial movement considering yield-PL (YPL) fluid. The YPL rheology model is usually preferred because it provides a better description of the flow behavior of most drilling fluids. The analytical solution yields accurate predictions, though not in convenient forms. Thus, a numerical scheme has been developed to obtain the solutions. After conducting an extensive parametric study, regression techniques were applied primarily to develop a simplified model (i.e., dimensionless correlation).

The performance of the correlation has been tested by use of field and laboratory measurements. Comparisons of the model predictions with the measurements showed a satisfactory agreement. In most cases, the model makes better predictions in terms of closeness to the measurements because of the application of a more realistic rheology model. The correlation and model are useful for slimhole, deepwater, and extended-reach drilling applications.
Adaptation of the CPR Preconditioner for Efficient Solution of the Adjoint Equation
Authors: Han Choongyong , Wallis John , Sarma Pallav , Li Gary , Schrader Mark L. , Chen Wen
Published: January 2013

It is well known that the adjoint approach is the most efficient approach for gradient calculation, and it can be used with gradient-based optimization techniques to solve various optimization problems, such as the production-optimization problem and the history-matching problem. The adjoint equation to be solved in the approach is a linear equation formed with the “transpose” of the Jacobian matrix from a fully implicit reservoir simulator. For a large and/or complex reservoir model, generalized preconditioners often prove impractical for solving the adjoint equation. Preconditioners specialized for reservoir simulation, such as constrained pressure residual (CPR), exploit properties of the Jacobian matrix to accelerate convergence, so they cannot be applied directly to the adjoint equation. To overcome this challenge, we have developed a new two-stage preconditioner for efficient solution of the adjoint equation by adaptation of the CPR preconditioner (named CPRA: CPR preconditioner for adjoint equation).

The CPRA preconditioner has been coupled with an algebraic multigrid (AMG) linear solver and implemented in Chevron's extended applications reservoir simulator (CHEARS®). The AMG solver is well known for its outstanding capability to solve the pressure equation of complex reservoir models; solving the linear system with the “transpose” of the pressure matrix is one of the two stages of construction of the CPRA preconditioner.

Through test cases, we have confirmed that the CPRA/AMG solver with generalized minimal residual (GMRES) acceleration solves the adjoint equation very efficiently with a reasonable number of linear-solver iterations. Adjoint simulations to calculate the gradients with the CPRA/AMG solver take approximately the same amount of time (at most) as do the corresponding CPR/AMG forward simulations. Accuracy of the solutions has also been confirmed by verifying the gradients against solutions with a direct solver. A production-optimization case study for a real field using the CPRA/AMG solver has further validated its accuracy, efficiency, and the capability to perform long-term optimization for large, complex reservoir models at low computational cost.
Accurate Resolution of Near-Well Effects in Upscaled Models Using Flow-Based Unstructured Local Grid Refinement
Authors: Karimi-Fard M.. , Durlofsky L.J.. J.
Published: January 2013

We present a new approach for representing wells in coarse-scale reservoir simulation models. The technique is based on an expanded well model concept which provides a systematic procedure for the construction of the near-well grid. The method proceeds by first defining an underlying fine-scale model, in which the well and any key near-well features such as hydraulic fractures are fully resolved using an unstructured grid. In the (coarse) simulation model, the geometry of the grid in the expanded well region, and the associated "radial" transmissibilities, are determined from the solution of a fine-scale, single-phase, well-driven flow problem. The coarse-scale transmissibilities outside of the well region are computed using existing local upscaling techniques or by applying a new global upscaling procedure. Thus, through use of near-well flow-based gridding and generalized local grid refinement, this methodology efficiently incorporates the advantages of highly-resolved unstructured grid representations of wells into coarse models. The overall model provided by this technique is compatible with any reservoir simulator that allows general unstructured cell-to-cell connections (model capabilities, in terms of flow physics, are defined by the simulator).

The expanded well modeling approach is applied to challenging 3D problems involving injection and production in a low-permeability heterogeneous reservoir, tight-gas production by a hydraulically-fractured well, and production in a gas-condensate reservoir. In the first two cases, where it is possible to simulate the fine-grid unstructured model, results using the expanded well model closely match the reference solutions, while standard approaches lead to significant error. In the gas-condensate example, which involves a nine-component compositional model, the reference solution is not computed, but the solution using the expanded well model is shown to be physically reasonable while standard coarse-grid solutions show large variation under grid refinement.
A Novel Alkaline/Surfactant/Foam Enhanced Oil Recovery Process
Authors: Guo Hua , Zitha Pacelli L.J. , Faber Rien , Buijse Marten
Published: January 2013

This article reports a laboratory study of a novel alkaline/surfactant/foam (ASF) process. The goal of the study was to investigate whether foaming a specially designed alkaline/surfactant (AS) formulation could meet the two key requirements for a good enhanced oil recovery (EOR) [i.e., lowering the interfacial tension (IFT) considerably and ensuring a good mobility control]. The study included phase-behavior tests, foam-column tests, and computed-tomography (CT)-scan-aided corefloods. It was found that the IFT of the designed AS and a selected crude oil drops by four orders of magnitude at the optimum salinity. The AS proved to be a good foaming agent in the column tests and corefloods in the absence of oil. The mobility reduction caused by the AS foam was hardly sensitive to salinity and increased with decreasing foam quality. CT-scanned corefloods demonstrated that AS foam, after a small AS preflush, recovered almost all the oil left after waterflooding. The oil-recovery mechanism by ASF combines the formation of an oil bank and the transport of emulsified oil by flowing lamellae. Further optimization of the ASF is needed to ensure that the oil is produced exclusively by the oil bank.
Interpreting Pressure and Flow-Rate Data From Permanent Downhole Gauges by Use of Data-Mining Approaches
Authors: Liu Yang , Horne Roland N.
Published: January 2013

The permanent downhole gauge (PDG) is a promising tool for reservoir testing but has yet to reach its full potential. Generally, conventional well-testing methods are most able to use small sections of constant-flow-rate data. However, data mining, a newly developed technique in computer science, is a tool that can reveal the relationship among variables from large volumes of data. The application of data-mining algorithms to synthetic and field data has been successful in extracting the reservoir model from variable-flow-rate and pressure-transient data. In fact, because of uncertainty in flow-rate measurements, this technique is one of the few ways to make use of the flow-rate data that are now available with some modern PDG tools.

The application is conducted in two steps. First, the pressure and flow-rate data from the PDG are used to train a nonparametric data-mining algorithm. The reservoir model is obtained implicitly in the form of polynomials in a high-dimensional Hilbert space defined by kernel functions when the algorithm converges after being trained to the data. Next, a specific flow-rate input (for example, constant rate) is fed into the data-mining algorithm. The data-mining algorithm will make a pressure prediction subject to the input flow rate. Because the data-mining algorithm has already obtained the reservoir model, the pressure prediction is expected to be the reservoir response given the constant flow rate. Therefore, the proposed constant flow rate and the predicted pressure reveal the reservoir model underlying the variable PDG data, without needing to specify in advance which reservoir model is to be used. Three methods (Methods A, B, and C), differing by input vectors, kernel functions, and presence of breakpoints detection, are proposed in the paper.

Synthetic noisy data and real field data were used to test this approach. Methods B and C were able to satisfactorily recover the wellbore/reservoir model in most considered cases. Even in extreme cases when the flow-rate data are noisy and changing frequently, and in the absence of any shut-ins, the method was still able to extract the reservoir models.