bluuebunny/crossref_metadata_2025 huggingface dataset:
Flow Cytometric Immunophenotypic Assessment of T-Cell Clonality by Vβ Repertoire Analysis
Authors: Tembhare Prashant , Yuan Constance M. , Xi Liqiang , Morris John C. , Liewehr David , Venzon David , Janik John E. , Raffeld Mark , Stetler-Stevenson Maryalice
Published: May 2011

Flow cytometric T-cell receptor (TCR)-Vβ repertoire analysis (TCR-Vβ-R) is a sensitive method for detection of T-cell clonality; however, no uniform approach exists to define clonality in neoplastic T cells. TCR-Vβ-R was evaluated in patients with a diagnosis of T-cell neoplasia in initial diagnostic specimens from 41 patients and for minimal residual disease (MRD) monitoring in 61 sequential samples from 14 patients with mature T-cell neoplasia. Gating strategies and criteria for detection of T-cell clonality were determined. In all 41 initial specimens, T-cell clonality was demonstrated via TCR-Vβ-R. The frequency of Vβ usage was consistent with random neoplastic transformation of TCR-Vβ subsets. MRD was successfully detected in follow-up samples from all 14 patients evaluated, Furthermore, MRD after therapy was quantitated in 48 peripheral blood specimens. TCR-Vβ-R analysis is a sensitive method for detection of T-cell clonality and is useful for diagnosis and MRD detection in multiple specimen types.
Ein Routing-Atlas für die strukturelle und visuelle Exposition des deutschen Internets
Authors: Schmidt Thomas C. , Wählisch Matthias , de Brün Markus , Häberlen Thomas
Published: May 2011

Ursprünglich wurde das Internets von der Idee geprägt, Übertragungsdienste für alle anzubieten, die eine wechselseitige Kopplung eingehen wollten. Seine skalierbare Architektur zielte auf eine globale Informationsinfrastruktur, in welcher nationale Ebenen oder staatengebundene Strukturen bedeutungslos waren. Das heutige Internet bildet jedoch in vielen Ländern eine potentiell kritische Infrastruktur, deren transparentes Funktionieren für die öffentliche Verwaltung und das private Geschäftshandeln, für Erziehung und Wissenschaft sowie die Information und Unterhaltung großer Bevölkerungskreise maßgeblich ist. Folgerichtig haben die Funktionsweise und die Funktionsqualität der Internet-Infrastruktur eine vielbeachtete politische Dimension angenommen.

In diesem Beitrag stellen wir Verfahren, methodische Auswertungen und deren Ergebnisse vor, welche das ‚deutsche Internet‘ identifizieren, inhaltlich und strukturell charakterisieren sowie seine verschiedenen Aspekte visualisieren. Ausgehend von der Fragestellung, welche Akteure an üblichen Kommunikationsprozessen mitwirken und diese folglich beeinflussen können, rekonstruieren und visualisieren wir Routing-Graphen auf der Ebene Autonomer Systeme, welche die zum Messzeitpunkt gültige Vermittlungsstruktur wiedergeben. Diese Messungen und Charakterisierungen werden aus einer vollständig automatisierten Kette von Abfrage- und Verfeinerungswerkzeugen gewonnen. Das Vorgehen ist insofern geeignet, ein online Monitoring-System für die Fehler- und Leistungsüberwachung des deutschen Internet-Routings zu errichten.
Experimentalumgebungen für das Internet der Dinge: Überblick, Taxonomie und praktische Nutzung
Authors: Pfisterer Dennis , Bimschas Daniel , Fischer Stefan
Published: May 2011

Die experimentelle Validierung neuartiger Ansätze hat, besonders im Kontext des Internet der Dinge, stark an Bedeutung gewonnen. Dieser Beitrag identifiziert Anforderungen an Experimentaleinrichtungen für das Internet der Dinge, gibt einen Überblick über aktive und öffentlich zugängliche Experimentaleinrichtungen und stellt verschiedene Plattformen auf Basis dieser Anforderungen qualitativ gegenüber. Es wird beispielhaft auf eine der Plattformen (WISEBED) näher eingegangen, um den Lesern einen Eindruck zu vermitteln, welche Möglichkeiten der experimentellen Forschung heute bereits zur Verfügung stehen. Des Weiteren wird besprochen, wie eigene Testbeds auf Basis der WISEBED Software betrieben und – falls gewünscht – mit anderen föderiert werden können.
A Mobility Model for the Realistic Simulation of Social Context
Authors: Fischer Daniel
Published: May 2011

Simulation is a fundamental means for evaluating mobile applications based on ad-hoc networks. In recent years, the new breed of social mobility models (SMMs) has risen. Contrary to most classical mobility models, SMMs model the social aspects of human mobility, i.e. which users meet, when and how often. Such information is indispensable for the simulation of a wide range of socially-aware communication protocols mostly based on delay-tolerant networks, including opportunistic ad-hoc routing and data dissemination systems. Each SMM needs a model of the relations between a set of relevant people (called social network model – SNM) in order to simulate their mobility. Existing SMMs lack flexibility since each of them is implicitly restricted to a specific, simplifying SNM.

We present GeSoMo (General Social Mobility Model), a new SMM that separates the core mobility model from the structural description of the social network underlying the simulation. This simple and elegant design principle gives GeSoMo generalizing power: Arbitrary existing and future SNMs can be used without changing GeSoMo itself. Our evaluation results show that GeSoMo produces simulations that are coherent with a broad range of empirical data describing real-world human social behavior and mobility.
Building a Distributed Trust Anchor in P2P Systems – Creating Trustworthy System Signatures without a Trusted Third Party
Authors: Liebau Nicolas C. , Mauthe Andreas U. , Steinmetz Ralf
Published: May 2011

Trustworthy applications in fully decentralized systems require a trust anchor. However, in p2p systems there does not exist a central trust anchor. This paper describes how a distributed anchor can be implemented efficiently in such and environment. Different alternatives have been proposed in the literature; most of them suggesting distributing the trust anchor by using a quorum decision, assuming that a random quorum would ensure trustworthiness. However, there are major issues, e.g., can it be assumed that a quorum was actually randomly chosen? how can it be verified, that a signature was created by a truly random quorum? In this paper a solution for this is presented through the token-based accounting scheme using specific mechanisms that ensure a distributed trust anchor in p2p systems and its evaluation.
A Novel Algorithm for Distributed Dynamic Interference Coordination in Cellular Networks
Authors: Necker Marc C.
Published: May 2011

Wireless systems based on Orthogonal Frequency Division Multiple Access (OFDMA) multiplex different users in time and frequency. One of the main problems in OFDMA-systems is the inter-cell interference. A promising approach to solve this problem is interference coordination (IFCO). In this paper, we present a novel distributed IFCO scheme, where a central coordinator communicates coordination information in regular time intervals. This information is the basis for a local inner optimization in every basestation. The proposed scheme achieves an increase of more than 100% with respect to the cell edge throughput, and a gain of about 30% in the aggregate spectral efficiency compared to a reuse 3 system.
ÖPNV-optimiertes Routing in unterbrechungstoleranten Netzen
Authors: Pögel Tobias
Published: May 2011

Für die Realisierung vieler neuer Dienste ist eine Kommunikation zwischen Fahrzeugen im ÖPNV notwendig. Die Bereitstellung geeigneter Infrastruktur oder die Nutzung bestehender kommerzieller Systeme verursacht aber hohe Kosten. Ein anderer Ansatz ist die Nutzung von DTN-Netzen, welche eine direkte Kommunikation der Fahrzeuge untereinander ermöglicht. Für den hierbei verfolgten ‚Store-and-Forward‘- Ansatz wird ein geeignetes Routing benötigt, welches möglichst effizient und ressourcenschonend arbeitet. Ein auf dieses Anwendungsszenario optimiertes Routing soll vorgestellt und analysiert werden. Dabei müssen die besonderen Eigenschaften des ÖPNV in dem Routing berücksichtigt werden. Mittels zusätzlich bereitgestellter Kontextinformationen werden dabei die potenziellen Kontakte zwischen den Fahrzeugen berechnet und für das Routing ausgenutzt.
Zur DIN SPEC 1041
Authors: Bauer Hans-Jörg
Published: May 2011

DIN SPEC 1041 beschreibt ein Phasenmodell für das „Outsourcing technologieorientierter wissensintensiver Dienstleistungen“. Das Modell deckt viele Aspekte von IT-Outsourcing- Verfahren ab. Für Rechenzentren von Hochschulen erscheint von das Dokument gerade angesichts zahlreicher Cloud-Angebote von hoher praktischer Relevanz.
Role of the basolateral amygdala and NMDA receptors in higher-order conditioned fear
Authors: Parkes Shauna L. , Westbrook R. Frederick
Published: May 2011

Laboratory rats learn to fear relatively innocuous stimuli which signal the imminent arrival of an innate source of danger, typically brief but aversive foot shock. Much is now known about the neural substrates underling the acquisition, consolidation and subsequent expression of this fear. Rats also learn to fear stimuli which signal learned sources of danger but relatively little is known about the neural substrates underlying this form of fear. Two Pavlovian conditioning paradigms used to study this form of fear are second-order conditioning and sensory preconditioning. In second-order conditioning, rats are first exposed to a signaling relationship between one stimulus, such as a tone, and aversive foot shock, and then to a signaling relationship between a second stimulus, such as a light, and the now dangerous tone. In sensory preconditioning, these phases are reversed: rats are first exposed to a signaling relationship between the light and the tone and then to a signaling relationship between the tone and the foot shock. In both paradigms, rats exhibit fear when tested with the light. In this review paper, we describe the evidence for higher-order forms of conditioning, the conditions which promote this learning and its contents. We compare and contrast the substrates of the learning underlying second-order and sensory preconditioning fear with those known to underlie the better studied first-order conditioned fear. We conclude with some comments as to the role of higher-order processes in anxiety disorders.
Process Capability Evaluation for Square Bumps with Mean Shift
Authors: Pearn W. L. , Hung H. N. , Tai Y. T. , Hou H. H.
Published: May 2011

Process capability indices have been widely used in manufacturing industries to provide numerical measures of process potential and performance. In in-plant applications, some inevitable process mean shift may be undetected when the statistical process control charts are applied, particularly, in the bumping process for square bumps. Bothe in 2002 provided a statistical reason for considering such a shift in the process mean to accommodate the undetected mean shifts for normally distributed processes when evaluating process capability. In this paper, we consider a bumping process for square bumps in which the data can be formulated as a non-central chi-square distribution, a class of non-normal distributions. To evaluate the popular yield-based process capability Cpk more accurately, we accommodate the magnitudes of undetected mean shifts using the modified capability evaluation formula and tabulate the detection powers under various subgroup sizes and non-central chi-square parameters. Based on the modified process capability evaluation, we can provide a more reliable process capability evaluation of capability index Cpk for square bumps and make more correct decisions. For illustration purpose, a real application in a bumping factory which is located on the Science-based Industrial Park in Hsinchu, Taiwan, is presented.
Hashimoto's thyroiditis is associated with papillary thyroid carcinoma: role of TSH and of treatment with l-thyroxine
Authors: Fiore E , Rago T , Latrofa F , Provenzale M A , Piaggi P , Delitala A , Scutari M , Basolo F , Di Coscio G , Grasso L , Pinchera A , Vitti P
Published: May 2011

The possible association between Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC) is a still debated issue. We analyzed the frequency of PTC, TSH levels and thyroid autoantibodies (TAb) in 13 738 patients (9824 untreated and 3914 under l-thyroxine, l-T4). Patients with nodular-HT (n=1593) had high titer of TAb and/or hypothyroidism. Patients with nodular goiter (NG) were subdivided in TAb−NG (n=8812) with undetectable TAb and TAb+NG (n=3395) with positive TAb. Among untreated patients, those with nodular-HT showed higher frequency of PTC (9.4%) compared with both TAb−NG (6.4%; P=0.002) and TAb+NG (6.5%; P=0.009) and presented also higher serum TSH (median 1.30 vs 0.71 μU/ml, P<0.001 and 0.70 μU/ml, P<0.001 respectively). Independently of clinical diagnosis, patients with high titer of TAb showed a higher frequency of PTC (9.3%) compared to patients with low titer (6.8%, P<0.001) or negative TAb (6.3%, P<0.001) and presented also higher serum TSH (median 1.16 vs 0.75 μU/ml, P<0.001 and 0.72 μU/ml, P<0.001 respectively). PTC frequency was strongly related with serum TSH (odds ratio (OR)=1.111), slightly related with anti-thyroglobulin antibodies (OR=1.001), and unrelated with anti-thyroperoxidase antibodies. In the l-T4-treated group, when only patients with serum TSH levels below the median value (0.90 μU/ml) were considered, no significant difference in PTC frequency was found between nodular-HT, TAb−NG and TAb+NG. In conclusion, the frequency of PTC is significantly higher in nodular-HT than in NG and is associated with increased levels of serum TSH. Treatment with l-T4 reduces TSH levels and decreases the occurrence of clinically detectable PTC.
Cardiac extrinsic apoptotic pathway is silent in young but activated in elder mice overexpressing bovine GH: interplay with the intrinsic pathway
Authors: Bogazzi Fausto , Russo Dania , Raggi Francesco , Bohlooly-Y Mohammad , Tornell Jan , Sardella Chiara , Lombardi Martina , Urbani Claudio , Manetti Luca , Brogioni Sandra , Martino Enio
Published: May 2011

Apoptosis may occur through the mitochondrial (intrinsic) pathway and activation of death receptors (extrinsic pathway). Young acromegalic mice have reduced cardiac apoptosis whereas elder animals have increased cardiac apoptosis. Multiple intrinsic apoptotic pathways have been shown to be modulated by GH and other stimuli in the heart of acromegalic mice. However, the role of the extrinsic apoptotic pathways in acromegalic hearts is currently unknown. In young (3-month-old) acromegalic mice, expression of proteins of the extrinsic apoptotic pathway did not differ from that of wild-type animals, suggesting that this mechanism did not participate in the lower cardiac apoptosis levels observed at this age. On the contrary, the extrinsic pathway was active in elder (9-month-old) animals (as shown by increased expression of TRAIL, FADD, TRADD and increased activation of death inducing signaling complex) leading to increased levels of active caspase 8. It is worth noting that changes of some pro-apoptotic proteins were induced by GH, which seemed to have, in this context, pro-apoptotic effects. The extrinsic pathway influenced the intrinsic pathway by modulating t-Bid, the cellular levels of which were reduced in young and increased in elder animals. However, in young animals this effect was due to reduced levels of Bid regulated by the extrinsic pathway, whereas in elder animals the increased levels of t-Bid were due to the increased levels of active caspase 8. In conclusion, the extrinsic pathway participates in the cardiac pro-apoptotic phenotype of elder acromegalic animals either directly, enhancing caspase 8 levels or indirectly, increasing t-Bid levels and conveying death signals to the intrinsic pathway.
Acute stimulation of glucagon secretion by linoleic acid results from GPR40 activation and [Ca2+]i increase in pancreatic islet α-cells
Authors: Wang Li , Zhao Yufeng , Gui Baosong , Fu Rongguo , Ma Feng , Yu Jun , Qu Ping , Dong Lei , Chen Chen
Published: May 2011

The role of free fatty acids (FFAs) in glucagon secretion has not been well established, and the involvement of FFA receptor GPR40 and its downstream signaling pathways in regulating glucagon secretion are rarely demonstrated. In this study, it was found that linoleic acid (LA) acutely stimulated glucagon secretion from primary cultured rat pancreatic islets. LA at 20 and 40 μmol/l dose-dependently increased glucagon secretion both at 3 mmol/l glucose and at 15 mmol/l glucose, although 15 mmol/l glucose reduced basal glucagon levels. LA induced an increase in cytoplasmic free calcium concentrations ([Ca2+]i) in identified rat α-cells, which is reflected by increased Fluo-3 intensity under confocal microscopy recording. The increase in [Ca2+]i was partly inhibited by removal of extracellular Ca2+ and eliminated overall by further exhaustion of intracellular Ca2+ stores using thapsigargin treatment, suggesting that both Ca2+ release and Ca2+ influx contributed to the LA-stimulated increase in [Ca2+]i in α-cells. Double immunocytochemical stainings showed that GPR40 was expressed in glucagon-positive α-cells. LA-stimulated increase in [Ca2+]i was blocked by inhibition of GPR40 expression in α-cells after GPR40-specific antisense treatment. The inhibition of phospholipase C activity by U73122 also blocked the increase in [Ca2+]i by LA. It is concluded that LA activates GPR40 and phospholipase C (and downstream signaling pathways) to increase Ca2+ release and associated Ca2+ influx through Ca2+ channels, resulting in increase in [Ca2+]i and glucagon secretion.
Vertical Bone Augmentation With Simultaneous Implant Placement Using Particulate Mineralized Bone and Mesenchymal Stem Cells: A Preliminary Study in Rabbit
Authors: Khojasteh Arash , Eslaminejad Mohamadreza Baghaban , Nazarian Hamid , Morad Golnaz , Dashti Seyyedeh Ghazaleh , Behnia Hossein , Stevens Mark
Published: May 2011

This study aimed to assess vertical bone augmentation with simultaneous implant placement in rabbit tibiae using particulate mineralized bone/fibrin glue/mesenchymal stem cell. Bone marrow was aspirated from tibiae of five 10-week-old New Zealand White male rabbits. Right and left tibiae of each rabbit were prepared, and a 3-mm protruding implant from tibial bone was placed in each side. Particulate allogenic bone/fibrin glue/mesenchymal stem cell combination was placed around test implants and particulate bone graft/fibrin glue around controls. Two months postoperatively, the animals were euthanized, and sections were prepared for histological analysis. The mean amount of vertical bone length was higher in the experimental group than the control group (2.09 mm vs 1.03 mm; P < .05). New supracrestal trabecular bone formation was also significantly higher in the test group (28.5 ± 4.5% vs 4.3 ±1.8%; P < .05). Mesenchymal stem cell/particulate allograft/fibrin glue appears to be a promising combination for vertical bone augmentation around simultaneously inserted implants in rabbit tibia.
Cyclic stress–strain response of compacted gravel
Authors: MODONI G. , KOSEKI J. , ANH DAN L.Q.
Published: May 2011

The positive effect of artificial densification on the stress–strain performance of granular materials is acknowledged from very ancient times but its importance greatly increased after the development of powerful machineries for the construction of large earth and rockfill dams. It is, however, pointed out that the extensive exploitation of gravelly soil is rarely supported by a thorough analytical assessment of the compaction effects on the constitutive relationships of materials, as would be desirable considering the massive dimension of these works and the complexity of typical loading conditions. The present research aims to fill this gap by means of a detailed experimental investigation and a theoretical analysis on the stress–strain response of dense gravels under monotonic and cyclic loading. The experimental campaign consists of a large number of triaxial tests performed at different initial mean effective stresses, following different stress paths and sequences, on artificially reconstituted samples of large dimensions compacted at different initial densities. The great care placed in the accuracy of laboratory instrumentation enables a high repeatability of experimental results, which is necessary to provide a clear focus on non-linearity in the limited strain range of the pre-failure response of the gravel. Based on the curve-fitting method the ingredients of an elasto-plastic constitutive model have been defined to predict the response of gravel under monotonic and cyclic loading. Elastic stiffness is simulated with a model derived from the literature which assumes a dependency on soil density together with inherent and stress-induced anisotropy. Plastic strain development from different initial stress and volume states of gravel is simulated by a critical state, multiple yielding constitutive model. Hardening and flow rules for the latter have been obtained by modifying previously existing laws in order better to reproduce the observations under monotonic compression, extension and cyclic loading. Validation of the proposed model is finally provided by comparing simulations and experimental results in a variety of testing conditions.
Chemo-mechanical effects in kaolinite. Part 2: exposed samples and chemical and phase analyses
Authors: WAHID A.S. , GAJO A. , DI MAGGIO R.
Published: May 2011

Continuing from part 1 of this paper, the results of laboratory tests on chemo-mechanical interactions in kaolinite subjected to the diffusion of inorganic, salt, acid and base solutions under an applied stress state are presented. Chemical analyses on the surnatant and analyses on X-ray diffraction patterns, high-temperature differential scanning calorimetry thermal gravimetry scans and transmission electron microscopy micrographs led to the conclusion that the bulk of kaolinite mineral is probably only slightly affected by the chemical interactions, the chemical attack being concentrated mainly at the particle edges, where it induces a change in the shape of the edges, which become irregular and less sharp. The mechanical behaviour of kaolinite is not affected by pore fluid salinity, but it is significantly affected by pore fluid pH: both acid or base solutions under an applied stress cause significant volumetric compression. Such strains are irreversible and probably related to the particle rearrangement induced mainly by the degradation of the particle edges, in addition to the decrease in basal friction angle (described in the companion paper) and the change of strength at edge-to-face contact points. The mechanical effects are slightly related to the dielectric constant of the pore fluid and this is consistent with the general conviction that interactions between kaolinite particles are mostly mechanical.
A field study of stress-dependent soil–water characteristic curves and permeability of a saprolitic slope in Hong Kong
Authors: NG C.W.W. , WONG H.N. , TSE Y.M. , PAPPIN J.W. , SUN H.W. , MILLIS S.W. , LEUNG A.K.
Published: May 2011

It is well recognised that field measurements of stress-dependent soil–water characteristic curves (SDSWCCs) and the permeability function (coefficient of permeability with respect to the water phase) are vital for assessing transient seepage, pore water pressure changes and the stability of unsaturated soil slopes. In this study, SDSWCCs and the permeability function were measured by using the instantaneous profile method on a saprolitic hillside in Tung Chung, Hong Kong. The ground profile comprises colluvium and completely decomposed tuff (CDT). A 3 m diameter circular plot was instrumented and subjected to two wetting–drying cycles. Throughout a 48-day monitoring period, variations of volumetric water content and matrix suction in the uppermost 3 m of soil were measured continuously using time-domain reflectometry moisture probes and jet-fill tensiometers, respectively. The field observations reveal that there is a clear trend of decreasing sizes of hysteretic loops of SDSWCCs with depth. In a comparison of the field- and laboratory-measured SDSWCCs, general agreement can be seen in the first wetting–drying cycle but not in the second cycle. The field-observed unsaturated permeability function is highly dependent on suction history (wetting–drying cycles). The field-measured permeability ranges from 4 × 10−7 m/s to 3 × 10−4 m/s in the colluvium, whereas the corresponding measured values vary from 4 × 10−7 m/s to 1 × 10−4 m/s in the CDT. Predictions of SWCC and permeability function using existing empirical approaches based on particle size distributions (PSDs) should be treated with caution. There is a clear qualitative and quantitative inconsistency between predictions of permeability function from PSD and field measurements.
Analysis of model sheet pile walls with plastic hinges
Authors: BOURNE-WEBB P.J. , POTTS D.M. , KöNIG D. , ROWBOTTOM D.
Published: May 2011

As part of a wider project investigating the implications of Eurocode 3, Design of steel structures – Part 5: Piling, centrifuge testing of model sheet pile walls and numerical back-analysis were undertaken. The aims of the study were to examine the effect of plastic hinging on embedded retaining wall response, and to verify calculation methods for use in wider generic calculations. Physical modelling of an anchored wall embedded in dry sand was undertaken. In some of the tests a hinge zone was introduced into the wall in order to reproduce a kinematic mechanism similar to that associated with plastic hinge formation. Finite-element calculations were undertaken using Lade's double-hardening cap model to represent the behaviour of the sand. The analyses generally yielded good accord with the test results in many aspects of the wall behaviour. In terms of the aims of the testing, the study of the effect of plastic hinging was not realistically captured, because the hinge zone was present from the outset of the test, allowing greater than expected earth pressure redistribution, and because the moment–curvature characteristic of the notched wall did not reproduce the buckling effects seen in the plastic bending response of steel sheet piles. On the other hand, the satisfactory agreement between the test observations and the numerical predictions gave confidence in the use of the calculation model for further generic calculations using realistic steel sheet pile moment–plastic curvature characteristics.
Use of Electronic Technologies to Promote Community and Personal Health for Individuals Unconnected to Health Care Systems
Authors: Crilly John F. , Keefe Robert H. , Volpe Fred
Published: May 2011

Ensuring health care services for populations outside the mainstream health care system is challenging for all providers. But developing the health care infrastructure to better serve such unconnected individuals is critical to their health care status, to third-party payers, to overall cost savings in public health, and to reducing health disparities.

Our increasingly sophisticated electronic technologies offer promising ways to more effectively engage this difficult to reach group and increase its access to health care resources. This process requires developing not only newer technologies but also collaboration between community leaders and health care providers to bring unconnected individuals into formal health care systems.

We present three strategies to reach vulnerable groups, outline benefits and challenges, and provide examples of successful programs.
Referrals Among Cancer Services Organizations Serving Underserved Cancer Patients in an Urban Area
Authors: Harris Jenine K. , Cyr Julianne , Carothers Bobbi J. , Mueller Nancy B. , Anwuri Victoria V. , James Aimee I.
Published: May 2011

Significant racial, socioeconomic, and geographic disparities exist nationwide in cancer screenings, treatments, and outcomes. Differences in health and social service provision and utilization may contribute to or exacerbate these disparities. We evaluated the composition and structure of a referral network of organizations providing services to underserved cancer patients in an urban area in 2007. We observed a need for increased awareness building among provider organizations, broader geographic coverage among organizations, and increased utilization of tobacco cessation and financial assistance services.
Impact on Social Inequalities of Population Strategies of Prevention for Folate Intake in Women of Childbearing Age
Authors: Sumar Nureen , McLaren Lindsay
Published: May 2011

We reviewed the recent assertion that population strategies of prevention may inadvertently widen social inequalities in health. We used folate intake as a case example to examine what is known about the impact on inequalities of 2 population strategies: one agentic (public information campaign) and the other structural (mandatory fortification policy). We found some support for our hypothesis that the mandatory fortification policy was less likely than were the information campaigns to lead to worsening inequalities in health by socioeconomic status or race/ethnicity; however, conclusions were complicated by different outcome variables and different economic and political regimes in which interventions took place.
Epidemiology of Urban Tuberculosis in the United States, 2000–2007
Authors: Oren Eyal , Winston Carla A. , Pratt Robert , Robison Valerie A. , Narita Masahiro
Published: May 2011

Objectives. We investigated tuberculosis (TB) incidence rates and characteristics of patients with TB in large US cities.

Methods. Using the Centers for Disease Control and Prevention's National Tuberculosis Surveillance System data, we categorized 48 cities annually from 2000 to 2007 as reporting decreasing or nondecreasing rates with Joinpoint analysis. We compared demographic, clinical, and treatment characteristics of patients with TB using bivariate and multivariate analyses.

Results. We found that 42 448 patients with TB in 48 cities accounted for 36% of all US patients with TB; these cities comprised 15% of the US population. The average TB incidence rate in the 48 cities (12.1 per 100 000) was higher than that in the US excluding the cities (3.8 per 100 000) but decreased at a faster rate. Nineteen cities had decreasing rates; 29 cities had nondecreasing rates. Patient characteristics did not conclusively distinguish decreasing and nondecreasing rate cities.

Conclusions. A significant TB burden occurs in large US cities. More than half (60%) of the selected cities did not show decreasing TB incidence rates. Studies of city-level variations in migration, socioeconomic status, and resources are needed to improve urban TB control.
Changing Drug Markets Under New Intellectual Property Regimes: The View From Central America
Authors: Godoy Angelina Snodgrass , Cerón Alejandro
Published: May 2011

The intellectual property rules inscribed in the Central American Free Trade Agreement have generated concern about access to medicines.

We examined the implementation of the new intellectual property regime by tracking the policies and practices in place across 4 Central American countries. Although all 4 were responding to the same requirements under the agreement, their implementation of intellectual property rules differed. Not only were institutional practices different, but the lists of drugs to which intellectual property protection was applied varied in both volume and content.

We also found that even without the influence of intellectual property, drug pricing in the region was often unpredictable and that lower cost was not the only motivation driving governments' purchasing decisions.
Associations Between Herpes Simplex Virus Type 2 and HCV With HIV Among Injecting Drug Users in New York City: The Current Importance of Sexual Transmission of HIV
Authors: Des Jarlais Don C. , Arasteh Kamyar , McKnight Courtney , Hagan Holly , Perlman David C. , Semaan Salaam
Published: May 2011

Objectives. We examined relationships between herpes simplex virus type 2 (HSV-2), a biomarker for sexual risk, and HCV, a biomarker for injecting risk, with HIV among injecting drug users (IDUs) who began injecting after large-scale expansion of syringe exchange programs in New York City.

Methods. We recruited 337 heroin and cocaine users who began injecting in 1995 or later from persons entering drug detoxification. We administered a structured interview covering drug use and HIV risk behavior and collected serum samples for HIV, HCV, and HSV-2 testing.

Results. HIV prevalence was 8%, HSV-2 39%, and HCV 55%. We found a significant association between HSV-2 and HIV (odds ratio [OR] = 7.9; 95% confidence interval [CI] = 2.9, 21.4) and no association between HCV and HIV (OR = 1.14; 95% CI = 0.5, 2.6). Black IDUs had the highest prevalence of HSV-2 (76%) and HIV (24%) but the lowest prevalence of HCV (34%).

Conclusions. Most HIV infections among these IDUs occurred through sexual transmission. The relative importance of injecting versus sexual transmission of HIV may be critical for understanding racial/ethnic disparities in HIV infection.
Modeling the Future Effects of a Menthol Ban on Smoking Prevalence and Smoking-Attributable Deaths in the United States
Authors: Levy David T. , Pearson Jennifer L. , Villanti Andrea C. , Blackman Kenneth , Vallone Donna M. , Niaura Raymond S. , Abrams David B.
Published: May 2011

We used a validated smoking simulation model and data from the 2003 Tobacco Use Supplement to the Current Population Survey to project the impact that a US menthol ban would have on smoking prevalence and smoking-attributable deaths. In a scenario in which 30% of menthol smokers quit and 30% of those who would have initiated as menthol smokers do not initiate, by 2050 the relative reduction in smoking prevalence would be 9.7% overall and 24.8% for Blacks; deaths averted would be 633 252 overall and 237 317 for Blacks.
Impact and Ethics of Excluding Sweetened Beverages From the SNAP Program
Authors: Barnhill Anne
Published: May 2011

The state of New York recently petitioned the US Department of Agriculture (USDA) for permission to conduct a demonstration project in which sweetened beverages would be excluded from the foods eligible to be purchased with Supplemental Assistance Nutrition Program (SNAP) benefits (i.e., food stamps) in New York City.

The USDA and advocacy groups have raised objections to new SNAP restrictions such as the proposed exclusion of sweetened beverages. Some objections rest on empirical issues best resolved by demonstration projects or pilot studies of new exclusions. Other objections question the equity of excluding sweetened beverages from SNAP; these objections are important but not ethically decisive.

The USDA should approve the proposed demonstration project and should encourage other pilot studies to assess the effects of excluding sweetened beverages from SNAP.
Estimation of Equilibrium-Adsorption Behavior at Cryogenic Temperatures of CO2 and N2 Using a Simple Predictive Tool
Authors: Bahadori Alireza
Published: May 2011

Conventionally, carbon dioxide (CO2) removal requires the use of a water-based amine solution and large absorber and regeneration towers. The capital and ongoing operational costs for this process are substantial, and the use (regeneration and disposal) of the amine solution can be problematic from the perspectives of both safety and the environment. Nitrogen (N2) can also be a problematic impurity in natural gas. Many researchers have been investigating the use of alternative gas-separation technologies (such as membranes and adsorption) targeted at removing N2 or CO2 from natural gas more efficiently. In this work, a simple-to-use predictive tool that is easier than existing approaches, is less complicated, and requires shorter computational times is applied to accurately predict the CO2 and N2-adsorption isotherms at low temperatures and pressures up to saturation for a commercial carbon molecular sieve as a function of temperature and partial pressure of these components. Accurate prediction of such data is useful in evaluating the feasibility of using pressure-swing adsorption to separate N2 and CO2 from natural gases at cryogenic temperatures. The proposed method showed consistently accurate results across the investigated wide pressure and temperature ranges, with an average absolute deviation of less than 1% for both N2 and CO2 compared to the existing Toth equation, which shows deviations of 3.5 and 1% for N2 and CO2, respectively. This simple-to-use approach can be of immense practical value for engineers and scientists to have a quick check on adsorption capacities of a given adsorbent at various temperatures and pressures without the necessity of any experimental measurements. In particular, natural-gas-process engineers would find the proposed approach to be user friendly, involving transparent calculations with no complex expressions.
Technical Evaluations To Support the Decision To Reinject Produced Water
Authors: Zuluaga E.. , Evans P.. , Nesom P.. , Spratt T.. , Daniels E..
Published: May 2011

The industry is moving away from overboard discharging of produced water and is increasingly selecting produced-water reinjection (PWRI) as the preferred method for waterflooding projects. This does not come without risks because the produced water usually needs to be supplemented by seawater in order to meet injection-volume requirements, increasing the risk of both scaling and souring.

PWRI supplemented by seawater was the selected produced-water-management strategy for Field M located in West Africa. Produced water from the adjacent Field K is also being considered for reinjection into Field M. Field M will be waterflooded from the beginning to maintain reservoir pressure close to the bubblepoint. Recent experiences of PWRI in other assets have created a challenging atmosphere because scaling posed a major risk to production. Field M had to go through very detailed and thorough souring and scaling evaluations to justify the feasibility of this project.

A consistent formation-water chemistry analysis for these evaluations was obtained by incorporating thermodynamic equilibrium constraints on formation-water composition from reservoir mineralogy and using knowledge of basin formation-water contributions from proximal salt formations. The evaluation of scaling potential was performed using ScaleSoftPitzer. The results show a low risk of scaling when the waters are commingled. Periodic formation scale squeezes are recommended to mitigate the scaling potential.

The souring-potential study was conducted using a full-field reservoir-souring simulation model (SourSimRL). SourSimRL superimposes criteria for the generation, partitioning, and transport of H2S. On the basis of the results, the souring potential is predicted to be generally moderate. The souring potential for the field is restricted by the availability of carbon nutrients in the injection waters and the high reservoir temperature of 250°F.

These rigorous technical evaluations were instrumental to obtain the support for PWRI and could be used as guidance for other PWRI projects.
Comparison of Leak-Detection Technologies for Continuous Monitoring of Subsea-Production Templates
Authors: Vrålstad Torbjørn , Melbye Alf G. , Carlsen Inge M. , Llewelyn David
Published: May 2011

Subsea leakages from underwater production facilities may have significant environmental and economical consequences. There is a wide range of different technologies available for detection of subsea leakages, depending on the type of application and approach to leak detection. The two most common approaches to direct subsea-leak detection are inspection/surveying, where sensors are attached to mobile units such as remotely operated vehicles (ROVs), and continuous monitoring, where the sensors are permanently installed at the seabed. For the latter case, there are several different types of leak-detection technologies, depending on whether templates or pipelines are to be monitored. While most subsea facilities are monitored by flow-measurement devices that can typically detect leaks that are greater than a few percent of overall flow, this paper addresses direct methods of leak detection suitable for smaller leaks.

The Norwegian Oil Industry Association (OLF) has initiated a series of projects on subsea-leak detection to obtain an overview of the different types of leak-detection systems available and to determine the practical applicability and functionality of these systems. An important issue in this regard is to test the leak-detection systems experimentally with both gas and oil leakages under realistic conditions. This paper presents results from comparative, experimental tests of five different leak-detection systems that are suitable for continuous monitoring of subsea templates with the goal of elucidating the strengths and limitations of the different detection principles.
Analyzing Production Data From Tight Oil Wells
Authors: Kabir Shah , Rasdi Faisal , Igboalisi B.
Published: May 2011

Performance prediction of wells producing from tight (microdarcy) formations is a daunting task. Complexities of geology (the presence/absence of naturally occurring fractures and contribution from different lithological layers), completion and fracture geometry complexities (multiple transverse or longitudinal fractures in long horizontal boreholes), and two-phase flow are impediments to simple performance forecasting.

We demonstrate the use of various analytical and numerical tools to learn about both short- and long-term reservoir behaviours. These tools include (a) traditional decline-curve analysis (Arps 1945), (b) Valko's stretched-exponential (SE) method (Valko 2009), (c) the Ilk et al. (2008, 2010) power-law exponential (PLE) method, (d) rate-transient-analysis (RTA) and transient-PI analyses to ascertain the stimulated-reservoir volume (SRV), and (e) numerical-simulation studies to gain insights into observed flow regimes.

The benefits of collective use of analytical modelling tools in history matching and forecasting both short- and long-term production performance of tight oil reservoirs are demonstrated with the use of real and simulated data. Diagnosing natural fractures, quantifying stimulated-reservoir volume, and assessing reliability of future performance predictions all became feasible by using an ensemble of analytical tools.
Pore-Level Investigation of Oil-Mobility Enhancement in Heavy-Oil Reservoirs
Authors: Ortiz-Arango Julian D. , Kantzas Apostolos
Published: May 2011

One of the most important properties for understanding multiphase flow in porous media is relative permeability. In two-phase flow, the relative permeability to a given phase is generally assumed only to be a function of its saturation, independent of the properties of fluids involved and/or flow conditions and ranging from zero to unity.

Considering the physical principles of multiphase flow through porous media, the momentum transfer or viscous coupling appears as a hidden driving mechanism that might lead to higher than expected oil-flow rates.

In an effort to provide a better understanding of oil mobility in heavy-oil reservoirs, a capillary model is used to assess the importance of lubrication in two-phase flow and to determine the effect of the viscous coupling on relative permeabilities. Different cross-sectional geometries are analyzed. The problem is addressed analytically even for the unequal-viscosity case by making use of the Galerkin method. The concept of contact angle is used in the determination of the fluid distribution inside a noncircular channel.

The model results show that the viscosity ratio theoretically affects relative permeabilities, especially in systems involving heavy oil.
The Effect of Suspended Solid Concentration and Oil Droplet Size Distribution on Particle Coalesces and Emulsion Stability
Authors: Ali Mohammad A. , Abeer Al-Farhan A. , Ali Al-Haddad A. , Suhaib Al-Kholosy A.
Published: May 2011

Reinjection of produced water is of increasing importance in the oil industry as water production continues to increase worldwide. It provides an environmentally acceptable solution to the disposal of produced water, and contributes to pressure maintenance. The performance of the injection wells and the distribution of the injected water are strongly influenced by water quality and the build-up of formation impairment around the wellbore.

Solid particles and small oil droplets present in the injected water can block the reservoir pores and cause rapid and severe permeability decline. Total removal of solids and oil may not be economically feasible or practically possible. Therefore, to minimize or slow the rate of impairment, it is important to understand the relationship between the impairment mechanism and water quality parameters, such as the total suspended solids and oil droplet.

This experimental study highlights the importance of water quality for the purpose of water injection. An online particle size analyzer was used to measure particle size distribution and coalesces in the injected water. Different concentrations of suspended solid, oil droplet, water salinity, and oil viscosity were used in this study. The effect of suspended solids on the stability of oil-in-water emulsion was investigated. Finally, coreflood system was used to measure permeability decline during water injection containing suspended particle.

The results showed that increasing suspended solid concentration did not affect particle coalesce, but increasing oil concentration resulted in an increase of oil droplets coalesces. However, when a combination of solid particles and oil droplets were suspended in water, newly solid-oil attachment particles were formed. Increasing water salinity did not affect solid-solid coalesce, but formed smaller oil droplets. Higher oil viscosity generated relatively in larger oil droplets than lower viscosity oil. Visual observation of emulsion containing suspended solids and oil droplets showed more stabilized emulsion with higher salinity water than at lower salinity water. However, weaker emulsion was seen when high oil viscosity concentration was used. Finally, permeability reduction of core samples caused by oil droplets alone was insignificant, but higher damage was seen by suspended solids, and severe damage was observed with combined solid and oil droplets.
The NBP Negative Binomial Model for Assessing Differential Gene Expression from RNA-Seq
Authors: Di Yanming , Schafer Daniel W , Cumbie Jason S , Chang Jeff H
Published: May 2011

We propose a new statistical test for assessing differential gene expression using RNA sequencing (RNA-Seq) data. Commonly used probability distributions, such as binomial or Poisson, cannot appropriately model the count variability in RNA-Seq data due to overdispersion. The small sample size that is typical in this type of data also prevents the uncritical use of tools derived from large-sample asymptotic theory. The test we propose is based on the NBP parameterization of the negative binomial distribution. It extends an exact test proposed by Robinson and Smyth (2007, 2008). In one version of Robinson and Smyth’s test, a constant dispersion parameter is used to model the count variability between biological replicates. We introduce an additional parameter to allow the dispersion parameter to depend on the mean. Our parametric method complements nonparametric regression approaches for modeling the dispersion parameter. We apply the test we propose to an Arabidopsis data set and a range of simulated data sets. The results show that the test is simple, powerful and reasonably robust against departures from model assumptions.
The IMF's Switch in Time
Authors: Stiglitz Joseph E.
Published: May 2011

So much for the Washington Consensus. The IMF has finally begun to come around and has realized that unfettered markets can create dangerous instability and inequality, according to Joseph Stiglitz of Columbia University.