bluuebunny/crossref_metadata_2025 huggingface dataset:
Specific genes involved in synthesis and editing of heparan sulfate proteoglycans show altered expression patterns in breast cancer
Authors: Fernández-Vega Iván , García Olivia , Crespo Ainara , Castañón Sonia , Menéndez Primitiva , Astudillo Aurora , Quirós Luis M
Published: January 2013

Background

The expression of a specific set of genes controls the different structures of heparan sulfate proteoglycans (HSPGs), which are involved in the growth, invasion and metastatic properties of cancerous cells. The purpose of this study is to increase knowledge of HSPG alterations in breast cancer.

Methods

Twenty-three infiltrating ductal adenocarcinomas (IDCs), both metastatic and non-metastatic were studied. A transcriptomic approach to the structure of heparan sulfate (HS) chains was used, employing qPCR to analyze both the expression of the enzymes involved in their biosynthesis and editing, as well as the proteoglycan core proteins. Since some of these proteoglycans can also carry chondroitin sulfate chains, we extended the study to include the genes involved in the biosynthesis of these glycosaminoglycans. Histochemical techniques were also used to analyze tissular expression of particular genes showing significant expression differences, of potential interest.

Results

No significant change in transcription was detected in approximately 70% of analyzed genes. However, 13 demonstrated changes in both tumor types (40% showing more intense deregulation in the metastatic), while 5 genes showed changes only in non-metastatic tumors. Changes were related to 3 core proteins: overexpression of syndecan-1 and underexpression of glypican-3 and perlecan. HS synthesis was affected by lower levels of some 3-O-sulfotransferase transcripts, the expression of NDST4 and, only in non metastatic tumors, higher levels of extracellular sulfatases. Furthermore, the expression of chondroitin sulfate also was considerably affected, involving both the synthesis of the saccharidic chains and sulfations at all locations. However, the pro-metastatic enzyme heparanase did not exhibit significant changes in mRNA expression, although in metastatic tumors it appeared related to increased levels of the most stable form of mRNA. Finally, the expression of heparanase 2, which displays anti-metastatic features, experienced a strong deregulation in all patients analyzed.

Conclusions

IDCs show alterations in the expression of HSPG genes; principally the expression and localization of proteoglycans and the sulfation patterns of glycosaminoglycan chains, depending on the metastatic nature of the tumor. In addition, the anti-proliferative molecule heparanase 2 experiences strong deregulation, thus highlighting it as a potentially interesting diagnostic factor.
Fluorescence modulation sensing of positively and negatively charged proteins on lipid bilayers
Authors: Robison Aaron D , Huang Da , Jung Hyunsook , Cremer Paul S
Published: January 2013

Background

Detecting ligand-receptor binding on cell membrane surfaces is required to understand their function and behavior. Detection platforms can also provide an avenue for the development of medical devices and sensor biotechnology. The use of fluorescence techniques for such purposes is highly desirable as they provide high sensitivity. Herein, we describe a technique that utilizes the sensitivity of fluorescence without directly tagging the analyte of interest to monitor ligand-receptor interactions on supported lipid bilayers. The fluorescence signal is modulated according to the charge state of the target analyte. The binding event elicits protonation or deprotonation of pH-responsive reporter dyes embedded in the lipid bilayer.

Methods

Supported lipid membranes containing ortho-conjugated rhodamine B-POPE (1-hexadecanoyl-2-(9Z-octadecenoyl)-sn-glycero-3-phosphoethanolamine), which fluoresces in its protonated but not in its deprotonated form, were utilized as sensor platforms for biotin-avidin and biotin-streptavidin binding events. The membranes contained 5 mol% biotin-PE (1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(cap biotinyl) (sodium salt) as a capture ligand. Supported lipid bilayers were formed in the channels of microfluidic devices and the fluorescence intensity of the dye was monitored as protein was introduced.

Results

The binding of avidin, which is positively charged at pH 7.2, made the bilayer surface charge more positive, which in turn deprotonated the ortho-rhodamine B dye, reducing its fluorescence. The binding of streptavidin, which is negatively charged at pH 7.2, had the opposite effect. Reducing the ionic strength of the analyte solution by removing 150 mM NaCl from the 10 mM phosphate buffered saline (PBS) solution raised the apparent pKa of the ortho-rhodamine B titration point by about 1 pH unit. This could be exploited in conjunction with bulk solution pH changes to turn the rhodamine B-POPE dye into a sensor for streptavidin involving a decrease, rather than an increase, in the fluorescence response, at pH values below streptavidin’s pI value.

Conclusions

This study demonstrates the ability to monitor ligand-receptor interactions on supported lipid bilayers through the protonation or deprotonation of reporter dyes for both negatively and positively charged analytes over a range of pH and ionic strength conditions. Specifically, the sensitivity and pH-operating range of this technique can be optimized by modulating the sensing conditions which are employed.
Evaluation of the relationship between GPR43 and adiposity in human
Authors: Dewulf Evelyne M , Ge Qian , Bindels Laure B , Sohet Florence M , Cani Patrice D , Brichard Sonia M , Delzenne Nathalie M
Published: January 2013

Background

GPR43 is a G-protein-coupled receptor that participates in adipocyte differentiation in mice and is over-expressed in adipose tissue of obese mice. The aim of this study was to investigate the implication of GPR43 in adipogenesis in humans and to determine the influence of obesity on its expression in human adipose tissue.

Findings

Preadipocytes were isolated from human omental adipose tissue and cultured during 13 days. One PPARγ agonist (troglitazone) and three GPR43 agonists (two physiological and one synthetic) were tested for their ability to induce differentiation. After 13 days, the three GPR43 agonists had no impact on aP2 expression, a marker of adipocyte differentiation, whereas troglitazone led to a huge over-expression of aP2 in these cells but tended to decrease GPR43 expression (p=0.06).

GPR43 and inflammatory markers expression was also quantified in omental adipose tissue from lean and obese individuals. GPR43 expression in total adipose tissue was similar between obese patients and lean subjects and did not correlate with aP2 expression. In contrast, GPR43 expression positively correlated with TNFα mRNA.

Conclusions

Our results suggest the absence of relationship between GPR43 and adipocyte differentiation in humans, unlike what was observed in mice. Furthermore, GPR43 expression is not increased in adipose tissue from obese subjects but could be related to TNFα-related inflammatory processes.
Serum amyloid P inhibits granulocyte adhesion
Authors: Maharjan Anu S , Roife David , Brazill Derrick , Gomer Richard H
Published: January 2013

Background

The extravasation of granulocytes (such as neutrophils) at a site of inflammation is a key aspect of the innate immune system. Signals from the site of inflammation upregulate granulocyte adhesion to the endothelium to initiate extravasation, and also enhance granulocyte adhesion to extracellular matrix proteins to facilitate granulocyte movement through the inflamed tissue. During the resolution of inflammation, other signals inhibit granulocyte adhesion to slow and ultimately stop granulocyte influx into the tissue. In a variety of inflammatory diseases such as acute respiratory distress syndrome, an excess infiltration of granulocytes into a tissue causes undesired collateral damage, and being able to reduce granulocyte adhesion and influx could reduce this damage.

Results

We found that serum amyloid P (SAP), a constitutive protein component of the blood, inhibits granulocyte spreading and granulocyte adhesion to extracellular matrix components. This indicates that in addition to granulocyte adhesion inhibitors that are secreted during the resolution of inflammation, a granulocyte adhesion inhibitor is present at all times in the blood. Although SAP affects adhesion, it does not affect the granulocyte adhesion molecules CD11b, CD62L, CD18, or CD44. SAP also has no effect on the production of hydrogen peroxide by resting or stimulated granulocytes, orN-formyl-methionine-leucine-phenylalanine (fMLP)-induced granulocyte migration. In mice treated with intratracheal bleomycin to induce granulocyte accumulation in the lungs, SAP injections reduced the number of granulocytes in the lungs.

Conclusions

We found that SAP, a constitutive component of blood, is a granulocyte adhesion inhibitor. We hypothesize that SAP allows granulocytes to sense whether they are in the blood or in a tissue.
Publishing and discovering context-dependent services
Authors: Ibrahim Naseem , Mohammad Mubarak , Alagar Vangalur
Published: January 2013

In service oriented computing, service providers and service requesters are main interacting entities. A service provider publishes the services it wishes to make public using service registries. A service requester initiates a discovery process to find the service that meets its requirements using the service registries. Current approaches for the publication and discovery do not realize the essential relationship between the service contract and the conditions in which the service can guarantee its contract. Moreover, they do not use any formal methods for specifying services, contracts, and compositions. Without a formal basis it is not possible to justify through a rigorous verification the correctness conditions for service compositions and the satisfaction of contractual obligations in service provisions. In our recent works, we have identified the role of contextual information, trustworthiness information and legal rules in service provision. This paper focuses on the publication and discovery of trustworthy context-dependent services as supported by the novel framework FrSeC. It introduces a novel ranking algorithm that ranks trustworthy context-dependent services according to the degree they match service requesters requirements. Finally, this paper introduces a prototype implementation for the matching and ranking of services as supported by FrSeC.
Combining creatinine and volume kinetics identifies missed cases of acute kidney injury following cardiac arrest
Authors: Pickering John W , Ralib Azrina Md , Endre Zoltán H
Published: January 2013

Introduction

Fluid resuscitation in the critically ill often results in a positive fluid balance, potentially diluting the serum creatinine concentration and delaying diagnosis of acute kidney injury (AKI).

Methods

Dilution during AKI was quantified by combining creatinine and volume kinetics to account for fluid type, and rates of fluid infusion and urine output. The model was refined using simulated patients receiving crystalloids or colloids under four glomerular filtration rate (GFR) change scenarios and then applied to a cohort of critically ill patients following cardiac arrest.

Results

The creatinine concentration decreased during six hours of fluid infusion at 1 litre-per-hour in simulated patients, irrespective of fluid type or extent of change in GFR (from 0% to 67% reduction). This delayed diagnosis of AKI by 2 to 9 hours. Crystalloids reduced creatinine concentration by 11 to 19% whereas colloids reduced concentration by 36 to 43%. The greatest reduction was at the end of the infusion period. Fluid dilution alone could not explain the rapid reduction of plasma creatinine concentration observed in 39 of 49 patients after cardiac arrest. Additional loss of creatinine production could account for those changes. AKI was suggested in six patients demonstrating little change in creatinine, since a 52 ± 13% reduction in GFR was required after accounting for fluid dilution and reduced creatinine production. Increased injury biomarkers within a few hours of cardiac arrest, including urinary cystatin C and plasma and urinary Neutrophil-Gelatinase-Associated-Lipocalin (biomarker-positive, creatinine-negative patients) also indicated AKI in these patients.

Conclusions

Creatinine and volume kinetics combined to quantify GFR loss, even in the absence of an increase in creatinine. The model improved disease severity estimation, and demonstrated that diagnostic delays due to dilution are minimally affected by fluid type. Creatinine sampling should be delayed at least one hour following a large fluid bolus to avoid dilution. Unchanged plasma creatinine post cardiac arrest signifies renal injury and loss of function.

Trial registration

Australian and New Zealand Clinical Trials Registry ACTRN12610001012066.
Glenn Ligon’s: AMERICA
Authors: Newbury Susanna
Published: January 2013

Glenn Ligon: AMERICA, the artist’s recent mid-career survey, argued that Ligon’s relationship to twentieth-century painting serves as an alternative means of examining the topics of identity, politics, and history that undergird the artist’s oeuvre. The exhibition reveals that the artist’s work leverages the expressionist possibilities of identity, figuration, and history on the abstract legacies of linguistic conceptualism. A continuous examination of representation grounded in the implacably figural substrate of race, gender, sexuality, and history, Ligon’s art highlights successive tiers of social abstraction in contemporary culture as they become visible and embodied in art objects.
Visual Poetry/Performing Script: The Art of Wosene Worke Kosrof
Authors: Kreamer Christine Mullen , Purpura Allyson
Published: January 2013

Drawing on numerous interviews with the artist, the authors use a loosely biographical approach to explore the conditions and inspirations of Wosene Worke Kosrof’s artistic production over his career of nearly forty years. Emphasis is placed on Wosene’s ability to layer multiple “stories” by evincing a temporal, spatial, and kinetic aesthetic in his visual work; on his choice of and approach to his materials; and on the changes in his oeuvre over the years: from painting and mixed media to monumental steel sculptures of Amharic letters, constructed in collaboration with local Ethiopian welders. The authors also bring Wosene’s work into conversation with some of the broader artistic movements that have used script “against itself.”
Nari Ward: Mirage Sub Lignum
Authors: Scruggs Dalila
Published: January 2013

This review is an interpretive description of Nari Ward’s Mirage Sub Lignum, a large-scale installation on view at the Massachusetts Museum of Contemporary Art.
The microRNA miR-7 regulates Tramtrack69 in a developmental switch in Drosophila follicle cells
Authors: Huang Yi-Chun , Smith Laila , Poulton John , Deng Wu-Min
Published: January 2013

Development in multicellular organisms includes both small incremental changes and major switches of cell differentiation and proliferation status. During Drosophila oogenesis, the follicular epithelial cells undergo two major developmental switches that cause global changes in the cell-cycle program. One, the switch from the endoreplication cycle to a gene-amplification phase, during which special genomic regions undergo repeated site-specific replication, is attributed to Notch downregulation, ecdysone signaling activation and upregulation of the zinc-finger protein Tramtrack69 (Ttk69). Here, we report that the microRNA miR-7 exerts an additional layer of regulation in this developmental switch by regulating Ttk69 transcripts. miR-7 recognizes the 3′ UTR of ttk69 transcripts and regulates Ttk69 expression in a dose-dependent manner. Overexpression of miR-7 effectively blocks the switch from the endocycle to gene amplification through its regulation of ttk69. miR-7 and Ttk69 also coordinate other cell differentiation events, such as vitelline membrane protein expression, that lead to the formation of the mature egg. Our studies reveal the important role miR-7 plays in developmental decision-making in association with signal-transduction pathways.
Successful Clinical Use of Daptomycin-Impregnated Bone Cement in Two-Stage Revision Hip Surgery for Prosthetic Joint Infection
Authors: Cortes Nicholas J , Lloyd John M , Koziol Leszek , O'Hara Lawrence
Published: January 2013

OBJECTIVE

To describe the safe and successful use of daptomycin-impregnated polymethyl methacrylate (PMMA) bone cement in the treatment of a case of recurrent prosthetic joint infection in a patient with multiple antibiotic allergies and past colonization with multiply antibiotic-resistant organisms.

CASE SUMMARY

A 79-year-old female had a history of chronic recurrent left prosthetic hip infection. The patient had confirmed allergies to multiple antibiotics and a past history of colonization with methicillin-resistant Staphylococcus aureus. At first-stage revision surgery, the infected prosthesis was removed and samples were sent for microbiologic culture. A spacer device was fashioned, with incorporation of daptomycin and gentamicin into the PMMA bone cement at a concentration of 5% w/w for each antibiotic. Systemic daptomycin and gentamicin were administered postoperatively for 14 days. Propionibacterium acnes was isolated from deep-tissue specimens. The patient made excellent postoperative progress and was discharged after 2 weeks. Second-stage revision surgery was performed at 6 months, with no signs of persistent infection. She remained well, pain free, and mobilizing independently 2 years later.

DISCUSSION

Daptomycin, a cyclic lipopeptide antibiotic, is approved for systemic treatment of endocarditis and skin and soft tissue infections. In vitro data demonstrate acceptable drug elution from and tensile strength of daptomycin-impregnated PMMA bone cement; however, clinical data are lacking. In our patient's case, the cement formulation was well tolerated, with no adverse effects detected, and demonstrated adequate mechanical strength in vivo. Infection with P. acnes, an unusual pathogen, was successfully treated. Further clinical studies are required to assess the efficacy of daptomycin-impregnated cement in infection with more typical pathogens, such as S. aureus.

CONCLUSIONS

Daptomycin impregnation of PMMA bone cement may be an option in cases in which patient or pathogen factors preclude use of routinely incorporated agents.
Tissue kallikrein, blood pressure regulation, and hypertension: insight from genetic kallikrein deficiency
Authors: Potier Louis , Waeckel Ludovic , Richer Christine , Roussel Ronan , Bouby Nadine , Alhenc-Gelas Francois
Published: January 2013

Tissue kallikrein has been suggested to be involved in blood pressure regulation and in protection against hypertension. However, this hypothesis remains debated. Recently, murine genetic models of kallikrein deficiency have been engineered and partial genetic deficiency in kallikrein activity has been characterized in humans. Studies in kallikrein-deficient mice indicate that kallikrein indeed influences blood pressure in the setting of mineralocorticoid excess and salt retention but not in normotensive animals and in high renin hypertension. These observations suggest that kallikrein can have antihypertensive function in physiological situations where sodium retention can trigger blood pressure elevation.
Adolescents with diabetes: support from healthcare teams and families
Authors: Singh Emma , Farruggia Susan P. , Peterson Elizabeth R.
Published: January 2013

Adolescents with diabetes must learn to manage their own health plans. Support from family is typically associated with positive self-management outcomes, yet less is known about how healthcare teams can facilitate positive self-management. This study aims to investigate the associations between family and healthcare team support and adolescent emotional, behavioral and physical diabetes management.

Method: A sample of 58 adolescents with type 1 diabetes completed self-report measures of their diabetes self-care management and their emotional distress or burden in relation to their diabetes. Adolescents’ diabetes clinic attendance and glycated hemoglobin (HBA1c) levels were also secured.

Results: Perceived positive support from the healthcare team or family appeared to have little or negative effect on diabetes management. However, the study found that greater healthcare non-support was related to poorer self-care and poorer self-management of diabetes control (less clinic attendance, poorer dietary control, less glucose testing, and higher HBA1c levels), and greater feelings of being distressed or burdened by diabetes.

Conclusions: These findings suggest that healthcare teams supporting adolescents should focus more on communicating and building relationships with adolescents in order to reduce perceived negative feelings of healthcare teams’ support.
A Phenomenological Micromechanical Model of FCC Metals under Radiation Induced Crystal Defects
Authors: Aoyagi Yoshiteru , Tsuru Tomohito , Kaji Yoshiyuki
Published: January 2013

Crystal defects induced by irradiation obstruct dislocation movement. Hence, the critical resolved shear stress of irradiated material increases. While part of the radiation defects are swept by dislocations released from dislocation sources; therefore localization of plastic deformation are caused by a decrease of radiation defects at the partial region. In this study, in order to predict increase of flow stress due to irradiation, information of density of radiation defects is introduced into a hardening modulus of crystal plasticity. Moreover, a decrease of the work-hardening ratio is represented by considering the disappearance of the radiation defects originating in the dislocation movement. Values of the controlling parameters operating effect of the radiation defects on the flow stress are estimated by a molecular dynamics simulation. We conduct crystal plasticity simulations for copper single crystals under a simple tensile condition. The macroscopic stress-strain responses such as the increase of yield stress and the decrease of work-hardening ratio due to irradiation are numerically predicted. We investigate the effect of radiation defects and the dislocation behaviors on processes of the strain localization.
Cluster Dynamics Simulation on Microstructure Evolution of Austenitic Stainless Steel and α-Iron Under Cascade Damage Condition
Authors: Abe Yosuke , Jitsukawa Shiro , Okubo Nariaki , Matsui Hideki , Tsukada Takashi
Published: January 2013

It is known that the degradation of mechanical properties of reactor pressure vessel steels caused by neutron irradiation is partly due to the formation of nanometer-size solute and point-defect (PD) clusters. Depending on temperature, PDs produced by collision cascades under neutron irradiation can migrate and either recombine or agglomerate to form larger defect clusters, greatly affecting the microstructure evolution and thus the mechanical properties of the material. Therefore, studying the rationalization of radiation-induced effects on the microstructure and their influence on the material properties through the development of predictive models is of great importance. A cluster dynamics (CD) simulation based on rate equations has been used to estimate the long-term evolution of point-defect clusters, i.e., clusters of self-interstitial atoms (SIAs) and those of vacancies and precipitations containing solute atoms. We have extended a CD simulation code to account for the possibility of all SIA clusters migrating three dimensionally, to reproduce the agglomeration of point-defects to form clusters during irradiation with collision cascades in austenitic stainless steel. We have also performed a parametric study of a production bias model, which can take into account the effects of fast one-dimensional motion of SIA loops, of defect accumulation processes in neutron-irradiated α-iron. It is found that formulations that take into account proper reaction kinetics for different materials can successfully reproduce the microstructure evolution under neutron irradiation.
Irradiation Testing of Zirconium Alloys and Stainless Steel in Fast Breeder Test Reactor, India
Authors: Murugan S. , Kumar P. V. , Joseph Jojo , Venugopal S. , Jayakumar T. , Raj Baldev
Published: January 2013

Fast Breeder Test Reactor (FBTR) at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, India is a sodium cooled fast reactor with a maximum neutron flux of about 3 × 1015 n/cm2/s. The neutron spectrum in the FBTR is hard and the damage rate attained in structural specimens is high. Compact pressurized capsules of zirconium alloys have been developed and subjected to irradiation in the FBTR to a fluence level of 1.1 × 1021 n/cm2 (E >1 MeV) at temperatures of 306 to 319°C to determine the irradiation creep rate of indigenously developed zirconium alloys (Zircaloy-2 and Zr-2.5%Nb alloy). To assess the changes in mechanical properties of FBTR grid plate material (modified type 316 stainless steel) due to prolonged low dose exposure, an accelerated irradiation test with dose levels up to 2.6 dpa (at 350°C) has also been carried out using miniature tensile test and disk specimens. Postirradiation examination (PIE) measurements carried out in the hot cells determined the creep rate of zirconium alloys, and indicated that the grid plate material has hardened but has still enough residual ductility. This paper presents salient features of the design and implementation of these irradiation experiments in FBTR and the results obtained during PIE.
Development of Models for Irradiation-induced Changes to Microstructure and Stress–Strain Relations of Austenitic Steels
Authors: Jitsukawa Shiro , Abe Yosuke , Suzuki Kazuhiko , Okubo Nariaki
Published: January 2013

Neutron irradiation often introduces severe changes in the mechanical properties of austenitic and martensitic steels (e.g., reduction of elongation below 400°C). This affects the mechanical responses of the reactor components. A large amount of hot cell work, however, is required in order to examine the mechanical response of intensely irradiated components experimentally, as well as to obtain materials irradiation data for the estimation of the component behavior. The development of a methodology with which to estimate the mechanical response of such components based on knowledge of the irradiation-induced microstructural changes and models of the post-irradiation mechanical properties is therefore an effective way to evaluate the structural integrity of an intensely irradiated structural component with minimal effort. A methodology for simulating the microstructural changes of face-centered cubic metals during irradiation using molecular dynamics and rate equation (RE) calculations has been developed. For RE calculation, the capture radius of the point defect clusters has been obtained through in situ ion irradiation experiments. The flow stress level is estimated from the dispersed barrier hardening equation with calculated microstructural data. By means of correlating the limited data from irradiation experiments with the calculated results (relation between the flow stress level and the microstructure of a heat), the flow stress levels of the heat can be estimated accurately as functions of the damage level and temperature. A Swift type constitutive equation with the concept of an equivalent plastic strain of irradiation hardening is proposed from the work hardening behavior of irradiated steels. By using this equation, it is possible to estimate the deformation and ductile fracture conditions of intensely irradiated components. This is a preliminary multi-scale method for estimating the mechanical response of irradiated components.
Precision of the Cone Calorimeter and ICAL Test Methods
Authors: Urbas Joe
Published: January 2013

Repeatability and reproducibility are typically determined for standard fire test methods on the basis of an interlaboratory test program (round-robin) to define their precision. Significant differences in precision were found in the past between the repeatability and reproducibility of smallscale and intermediate- and large-scale fire test methods that all utilize oxygen calorimetry to measure heat release rate. Repeatability of heat release rate related measurements with small-scale apparatus has been found to be significantly better than the repeatability of the intermediate and large-scale apparatuses. In this paper, the results of two round-robins are compared on the basis of relative repeatability standard deviations and relative reproducibility standard deviations calculated for individual materials for individual test parameters. The first one was a cone calorimeter round-robin and the second was an intermediate-scale calorimeter (ICAL) round-robin. The objective and subjective factors that might have contributed to the differences between the two test methods in both repeatability and reproducibility were analyzed. The most important factors that caused the differences in the ICAL round-robin were higher theoretical uncertainty of the ICAL, inadequate pre-round-robin calibrations, the small numbers of participating laboratories and samples tested, prevalence of fire-retardant-treated materials, and possible failure of some of the laboratories to fully comply with the standard. These factors, especially the fact that the testing procedures and apparatuses in the participating laboratories may not have been in complete accordance with the standards, indicate that the results of the round-robins did not reflect the real precision of the test methods. However, the terminology using the two components of precision, repeatability and reproducibility, is maintained in this paper except where a specific distinction is noted. Recommendations are made on how to improve the results of future fire test round-robins.
OLED degradation described by using a time-dependent local relaxation model
Authors: Racine Benoît , Féry Christophe , Bettinelli Armand , Doyeux Henri , Ciná Salvatore
Published: January 2013

The main mechanisms responsible for the luminance degradation in OLEDs driven under constant current has not yet been identified. In this paper we propose a new approach to describe the intrinsic mechanisms involved in the OLED aging. We will first show that a stretched exponential decay can be used to fit almost all the luminance vs time curves obtained under different driving conditions. In this way we are able to prove that they can all be described by employing a single free parameter model.

By using as an approach based on local relaxation events, we will demonstrate that a single mechanism is responsible for the dominant aging process. Furthermore, we will demonstrate that the main relaxation event is the annihilation of one emissive center.

We will then use our model to fit all the experimental data measured under different driving condition, and show that by carefully fitting the accelerated luminance lifetime-curves, we can extrapolate the low-luminance lifetime needed for real display applications, with a high degree of accuracy.
Growth and Resource Use of the Invasive Grass, Pampasgrass (Cortaderia selloana), in Response to Nitrogen and Water Availability
Authors: Vourlitis George L. , Kroon Joanna L.
Published: January 2013

Exotic invasive species are nonnative species that thrive outside of their native habitat, and while it is difficult to determine which exotic plants will become invasive, successful invaders often share a wide range of traits including high growth rate and reproductive output, vegetative reproduction, high population growth rates, early reproductive age, phenotypic and physiological plasticity, and high resource use efficiency. Here we report on the response of pampasgrass, an important exotic invasive plant of the western United States, to experimental variations in soil nitrogen (N) and water availability. Given its ability to invade a wide variety of ecosystems in southern California, we hypothesized that pampasgrass would have higher water and N use efficiency under conditions of low water and N availability but rapid growth and resource use under conditions of high water and N availability. Our data support this hypothesis and indicate that pampasgrass exhibited large variations in growth, carbon allocation, morphology, and N and phosphorus (P) nutrition to variations in N availability and water table depth. Many of these traits are highly correlated with invasive performance, and the high N and P use efficiency observed under low soil N (control) and water table, coupled with the large increase in physiological performance and resource use under high N and water table, indicate that pampasgrass is highly flexible to soil resource levels that are typical for coastal sage scrub and riparian ecosystems of southern California. Such flexibility in resource use could allow pampasgrass to persist in low-resource environments and expand as resource levels increase.
Body mass estimations and paleobiological inferences on a new species of large Caracara (Aves, Falconidae) from the late Pleistocene of Uruguay
Authors: Jones Washington , Rinderknecht Andrés , Migotto Rafael , Blanco R. Ernesto
Published: January 2013

The caracaras belong to a group of falconids with widespread geographical distribution in the Western Hemisphere, particularly in South America. Here we report fossil remains of a new species attributed to the genusCaracarafrom the late Pleistocene of Uruguay. This bird would have had an estimated body mass of 3700 grams, a value that greatly exceeds the maximum body mass reported for living falconids. Apparently, it would have had flying capabilities, in contrast to another paleospecies recently described from the Holocene of Jamaica. This fossil bird was found in association with mammal megafaunal remains and could offer new insights about the role of carnivorous birds in late Pleistocene environments of South America.
Echinoderms from the Lower Devonian (Emsian) of Bolivia (Malvinokaffric Realm)
Authors: Thompson Jeffrey R. , Ausich William I. , Smith Legrand
Published: January 2013

Crinoid faunas from the Lower Devonian of South America are poorly known. Two new taxa are described from the Emsian Icla Formation at Cerro Kochis in the Cochabamba Department: the rhodocrinitid, Lutocrinus boliviaensis n. gen. n. sp. and Griphocrinus pirovanoi n. sp. Two additional camerates are reported from the Emsian Belèn Formation of the Altiplano region in the La Paz Department, including Ctenocrinus branisai n. sp. and Boliviacrinus isaacsoni McIntosh, 1988. In addition, a specimen of the blastoid, Pachyblastus dicki Bremier and Macurda, 1972, was recovered from the Altiplano region. These crinoids and material previously collected by Leonardo Branisa, including specimens of C. branisai n. sp., Apurocrinus sucrei McIntosh, 1981, B. isaacsoni McIntosh, 1988, and L. boliviaensis n. sp., are described and revised. The specimens give new insights into the Lower Devonian Malvinokaffric Realm of Bolivia, a relatively new frontier in crinoid paleontology.
Food web structure in oil sands reclaimed wetlands
Authors: Kovalenko K. E. , Ciborowski J. J. H. , Daly C , Dixon D. G. , Farwell A. J. , Foote A. L. , Frederick K. R. , Costa J. M. Gardner , Kennedy K , Liber K , Roy M. C. , Slama C. A. , Smits J. E. G.
Published: January 2013

Boreal wetlands play an important role in global carbon balance. However, their ecosystem function is threatened by direct anthropogenic disturbance and climate change. Oil sands surface mining in the boreal regions of Western Canada denudes tracts of land of organic materials, leaves large areas in need of reclamation, and generates considerable quantities of extraction process‐affected materials. Knowledge and validation of reclamation techniques that lead to self‐sustaining wetlands has lagged behind development of protocols for reclaiming terrestrial systems. It is important to know whether wetlands reclaimed with oil sands process materials can be restored to levels equivalent to their original ecosystem function. We approached this question by assessing carbon flows and food web structure in naturally formed and oil sands‐affected wetlands constructed in 1970–2004 in the postmining landscape. We evaluated whether a prescribed reclamation strategy, involving organic matter amendment, accelerated reclaimed wetland development, leading to wetlands that were more similar to their natural marsh counterparts than wetlands that were not supplemented with organic matter. We measured compartment standing stocks for bacterioplankton, microbial biofilm, macrophytes, detritus, and zoobenthos; concentrations of dissolved organic carbon and residual naphthenic acids; and microbial production, gas fluxes, and aquatic–terrestrial exports (i.e., aquatic insect emergence). The total biomass of several biotic compartments differed significantly between oil sands and reference wetlands. Submerged macrophyte biomass, macroinvertebrate trophic diversity, and predator biomass and richness were lower in oil sands‐affected wetlands than in reference wetlands. There was insufficient evidence to conclude that wetland age and wetland amendment with peat–mineral mix mitigate effects of oil sands waste materials on the fully aquatic biota. Although high variability was observed within most compartments, our data show that 20‐year‐old wetlands containing oil sands material have not yet reached the same level of function as their reference counterparts.
Change in School Nutrition–Related Laws From 2003 to 2008: Evidence From the School Nutrition–Environment State Policy Classification System
Authors: Mâsse Louise C. , Perna Frank , Agurs-Collins Tanya , Chriqui Jamie F.
Published: January 2013

Objectives. We examined state laws affecting the school food environment and changes in these laws between 2003 to 2008.

Methods. We used the Westlaw legal database to identify state-codified laws, with scoring derived from the updated School Nutrition–Environment State Policy Classification System, obtained from the Classification of Laws Associated With School Students Web site.

Results. States significantly changed their school nutrition laws from 2003 to 2008, and many increased the stringency of the laws targeting competitive foods (snacks and entrées sold in competition with the school meal) and beverages sold in school and for in-school fundraising. Many states enacted laws that mandated the establishment of a coordinating or advisory wellness team or council. Stronger laws were enacted for elementary grades. We found tremendous variability in the strength of the laws and plenty of room for improvement.

Conclusions. State law governing school nutrition policies significantly changed from 2003 to 2008, primarily affecting the competitive food environment in schools. The extent to which changes in school nutrition laws will lead to desired health outcomes is an area for additional research.
Impact Evaluation of a Public Bicycle Share Program on Cycling: A Case Example of BIXI in Montreal, Quebec
Authors: Fuller Daniel , Gauvin Lise , Kestens Yan , Daniel Mark , Fournier Michel , Morency Patrick , Drouin Louis
Published: January 2013

Objectives. We examined associations between residential exposure to BIXI (BIcycle-taXI)—a public bicycle share program implemented in Montreal, Quebec, in 2009, which increases accessibility to cycling by making available 5050 bicycles at 405 bicycle docking stations—and likelihood of cycling (BIXI and non-BIXI) in Montreal over the first 2 years of implementation.

Methods. Three population-based samples of adults participated in telephone surveys. Data collection occurred at the launch of the program (spring 2009), and at the end of the first (fall 2009) and second (fall 2010) seasons of implementation. Difference in differences models assessed whether greater cycling was observed for those exposed to BIXI compared with those not exposed at each time point.

Results. We observed a greater likelihood of cycling for those exposed to the public bicycle share program after the second season of implementation (odds ratio = 2.86; 95% confidence interval = 1.85, 4.42) after we controlled for weather, built environment, and individual variables.

Conclusions. The implementation of a public bicycle share program can lead to greater likelihood of cycling among persons living in areas where bicycles are made available.
A Comprehensive Examination of the Influence of State Tobacco Control Programs and Policies on Youth Smoking
Authors: Farrelly Matthew C. , Loomis Brett R. , Han Beth , Gfroerer Joe , Kuiper Nicole , Couzens G. Lance , Dube Shanta , Caraballo Ralph S.
Published: January 2013

Objectives. We examined the influence of tobacco control policies (tobacco control program expenditures, smoke-free air laws, youth access law compliance, and cigarette prices) on youth smoking outcomes (smoking susceptibility, past-year initiation, current smoking, and established smoking).

Methods. We combined data from the 2002 to 2008 National Surveys on Drug Use and Health with state and municipality population data from the US Census Bureau to assess the associations between state tobacco control policy variables and youth smoking outcomes, focusing on youths aged 12 to 17 years. We also examined the influence of policy variables on youth access when these variables were held at 2002 levels.

Results. Per capita funding for state tobacco control programs was negatively associated with all 4 smoking outcomes. Smoke-free air laws were negatively associated with all outcomes except past-year initiation, and cigarette prices were associated only with current smoking. We found no association between these outcomes and retailer compliance with youth access laws.

Conclusions. Smoke-free air laws and state tobacco control programs are effective strategies for curbing youth smoking.
Important Considerations in Conducting Statistical Mediation Analyses
Authors: Morera Osvaldo F. , Castro Felipe González
Published: January 2013

An investigator wishes to examine mediation in a randomized control trial of the effectiveness of an intervention, which consists of a computerized decision aid for promoting colorectal cancer screening. Mediation is a naturally occurring process, and in any given instance, research investigators seek to ascertain whether it has occurred. In the case of a prevention intervention for a specific chain of events, mediation occurs (1) when the prevention intervention effects a change on a targeted intermediate condition: a mediator, for example, a person’s intentions to get a colorectal screening examination; and (2) when, at a later point in time, this condition effects a change on a targeted outcome, for example, the actual behavior of getting a colorectal screening exam. Full mediation is said to occur when the effectiveness of the intervention on the targeted outcome only takes place through the intermediate condition and does not directly affect the targeted outcome. Partial mediation is said to occur when the intervention causes changes in both the intermediate condition and the targeted outcome. The assessment of mediation is important because conclusions about the efficacy of a public health intervention may depend on how these indirect influences are assessed.
Hispanic Mortality Paradox: A Systematic Review and Meta-Analysis of the Longitudinal Literature
Authors: Ruiz John M. , Steffen Patrick , Smith Timothy B.
Published: January 2013

To investigate the possibility of a Hispanic mortality advantage, we conducted a systematic review and meta-analysis of the published longitudinal literature reporting Hispanic individuals’ mortality from any cause compared with any other race/ethnicity. We searched MEDLINE, PubMed, EMBASE, HealthSTAR, and PsycINFO for published literature from January 1990 to July 2010.

Across 58 studies (4 615 747 participants), Hispanic populations had a 17.5% lower risk of mortality compared with other racial groups (odds ratio = 0.825; P < .001; 95% confidence interval = 0.75, 0.91). The difference in mortality risk was greater among older populations and varied by preexisting health conditions, with effects apparent for initially healthy samples and those with cardiovascular diseases. The results also differed by racial group: Hispanics had lower overall risk of mortality than did non-Hispanic Whites and non-Hispanic Blacks, but overall higher risk of mortality than did Asian Americans.

These findings provided strong evidence of a Hispanic mortality advantage, with implications for conceptualizing and addressing racial/ethnic health disparities.
Early Childhood Lead Exposure and Academic Achievement: Evidence From Detroit Public Schools, 2008–2010
Authors: Zhang Nanhua , Baker Harolyn W. , Tufts Margaret , Raymond Randall E. , Salihu Hamisu , Elliott Michael R.
Published: January 2013

Objectives. We assessed the long-term effect of early childhood lead exposure on academic achievement in mathematics, science, and reading among elementary and junior high school children.

Methods. We linked early childhood blood lead testing surveillance data from the Detroit Department of Health and Wellness Promotion to educational testing data from the Detroit, Michigan, public schools. We used the linked data to investigate the effect of early childhood lead exposure on academic achievement among school-aged children, both marginally and adjusted for grade level, gender, race, language, maternal education, and socioeconomic status.

Results. High blood lead levels before age 6 years were strongly associated with poor academic achievement in grades 3, 5, and 8. The odds of scoring less than proficient for those whose blood lead levels were greater than 10 micrograms per deciliter were more than twice the odds for those whose blood lead levels were less than 1 micrograms per deciliter after adjustment for potential confounders.

Conclusions. Early childhood lead exposure was negatively associated with academic achievement in elementary and junior high school, after adjusting for key potential confounders. The control of lead poisoning should focus on primary prevention of lead exposure in children and development of special education programs for students with lead poisoning.
Living Through Some Giant Change: The Establishment of Abortion Services
Authors: Schoen Johanna
Published: January 2013

This article traces the establishment of abortion clinics following Roe v Wade. Abortion clinics followed one of two models: (1) a medical model in which physicians emphasized the delivery of high quality medical services, contrasting their clinics with the back-alley abortion services that had sent many women to hospital emergency rooms prior to legalization, or (2) a feminist model in which clinics emphasized education and the dissemination of information to empower women patients and change the structure of women’s health care. Male physicians and feminists came together in the newly established abortion services and argued over the priorities and characteristics of health care delivery. A broad range of clinics emerged, from feminist clinics to medical offices run by traditional male physicians to for-profit clinics. The establishment of the National Abortion Federation in the mid-1970s created a national forum of health professionals and contributed to the broadening of the discussion and the adoption of compromises as both feminists and physicians influenced each other's practices.