bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of Gas Diffusivity in Heavy Oils and Bitumens by Use of Pressure-Decay Test and Establishment of Minimum Time Criteria for Experiments
Authors: Ratnakar Ram R. , Dindoruk Birol 
Published: May 2015

Summary
Molecular diffusion plays a very important role in various reservoir processes, especially in the oil-recovery processes where convective forces are not dominant or when direct frontal contact and mixing are not possible. For example, in heavy-oil and bitumen recovery, injected light hydrocarbons can diffuse into the oil beyond the potential fronts and/or convective zones and promote the effectiveness of the displacement process, reducing in-situ viscosities and in turn enhancing the oil recovery.
Similarly, diffusive mixing can also be a dominant mechanism in the gas-redissolution process, even in lighter-hydrocarbon systems. For example, it controls how much gas will be dissolved in oil and how long it will take to dissolve, in the absence of mechanical/convective mixing, as in the case of reservoir repressurization. The extent of dissolution of a gas into oil is governed by its solubility, but the rate is controlled by both molecular diffusivity and solubility. Thus, accurate determination of these parameters is essential to design and understand displacement processes.
Despite the significance of diffusion in various aspects of oil recovery, there are very few experimental studies available in the literature addressing the diffusion of gas in heavy oils. Experimental work is most commonly based on the pressure-decay concept. However, the parameter inversion in these tests relies on an error-function solution that neglects the transient processes at the gas/oil interface and assumes constant-saturation concentration. This assumption is not appropriate when decay in pressure is large because pressure in the gas cap changes continuously as gas is dissolved in the oil, and hence the gas solubility varies with time. One of the major issues related to this experimental process is that it takes a long time (order of several days to several months) to achieve steady-state (converged) solution to determine diffusivity.
In this work, we have
Experimentally investigated the diffusion of methane in heavy oils as well as light oils by use of a pressure-decay test Captured properly the variation in gas concentration in oil at the gas/oil interface with time by expressing gas solubility in terms of Henry's constant in the mathematical model Developed the exact solution of the 1D pressure-decay (transient-diffusion) model with pressure-dependent gas/oil-interface concentration and shown that after a long time, pressure decays exponentially in time with an exponent that depends on diffusivity as well as solubility Presented the inversion technique to determine the diffusivity and other parameters from late-transient-pressure data, and shown the convergence in their estimates (Most importantly) developed a cutoff criterion permitting us to stop the experiments while still being able to extract the converged diffusivity values (this is important in situations when the experiment is stopped prematurely for technical or other reasons)
Theories and Applications of Pulsed-Jet Drilling With Mechanical Specific Energy
Authors: Minghui Wei , Gensheng Li , Huaizhong Shi , Shuaishuai Shi , Zhaokun Li , Yi Zhang 
Published: May 2015

Summary
Mechanical specific energy (MSE) is the amount of energy required to destroy a unit volume of rock. The main work of this study is to bring the hydraulic energy of a pulsed jet into an MSE model and further analyze the mechanism of improving the rate of penetration (ROP) for pulsed-jet drilling on the basis of the model. Laboratory experiments are used to obtain the relationship of bit hydraulic horsepower between pulsed jet and continuous jet, and then the MSE model of pulsed-jet drilling is established. According to the MSE theory, the major mechanisms of improving ROP in pulsed-jet drilling are changing the breaking strength of rock and improvement of downhole-cuttings-cleaning efficiency. Field tests and data presented in this study showed that this model could be used to evaluate drilling efficiency and identify abnormal conditions for pulsed-jet drilling. All tests were operated with similar parameters and on the same drilled formation. The field results illuminate that pulsed-jet drilling has higher drilling efficiency compared with conventional drilling. Moreover, the specific patterns for abnormal conditions can be detected in real time in the process of pulsed-jet drilling. This model is less ambiguous as well as robust. Therefore, it could provide theoretical support for the wide application of pulsed-jet drilling.
Evaluation of Reference Genes for RT‐qPCR Normalization in Cowpea under Drought Stress during Biological Nitrogen Fixation
Authors: Da Silva Helder Anderson P. , Nardeli Sarah Muniz , Alves‐Ferreira Marcio , Simões‐Araújo Jean Luiz 
Published: May 2015

ABSTRACTReverse transcription–quantitative polymerase chain reaction (RT‐qPCR) has emerged as an important technique for gene‐expression analysis. However, for accurate and reliable results, the data normalization using appropriated reference genes is critical, and a systematic validation of reference genes in cowpea (Vigna unguiculata L. Walp), a high stress‐tolerant leguminous, has not been performed. To provide suitable reference genes in this strategic leguminous species under drought stress, we evaluated the expression stability of eight candidate genes using geNorm and NormFinder algorithms. The analyses were performed in nodules and leaves separately (organ‐specific analysis) or grouping the two organs (global analysis). Our results showed VuPp2A and VuUbq28 as the best reference genes—by both algorithms—for global analysis. For organ‐specific analyses, geNorm identified VuPp2A/VuYls8 as the most stable genes for nodules and NormFinder identified VuPolyP/VuPp2A as the most stable ones for leaves. Moreover, VuUbq28 was always identified among the top three genes. The proposed reference genes were validated by two stress‐responsive genes (VusHsp17.7 and VuNced1). In conclusion, VuPp2A was the best reference gene in all analyses, followed by VuUbq28, VuYls8, and VuPolyP as the most stable genes for RT‐qPCR data normalization in cowpea under drought stress. These genes could be a good starting point for reference‐gene validation in other leguminous species under stress and BNF conditions.
Influence of Discontinuous Precipitation on the Creep Behavior of a β-Solidified γ-TiAl Based Alloy
Authors: Kastenhuber M. , Gaitzenauer A. , Hawranek G. , Krajnc B. , Clemens H. , Mayer S. 
Published: May 2015

Abstract
Owing to their excellent high temperature properties, intermetallic γ-TiAl based alloys are potentially suitable materials for applications in the aviation and automotive industry. In order to adjust a fine lamellar microstructure with optimum properties, the forging process is followed by a multi-stage heat treatment. During the final annealing process, a discontinuous precipitation reaction, a so-called cellular reaction, may occur which decomposes the fine lamellae in the α2/γ colonies. A stable microstructure is a crucial factor in the development of highly creep resistant alloys. In the scope of this work, various heat treatments were performed in order to adjust microstructures with a varying proportion of discontinuous precipitation. Furthermore, creep tests were performed at 800 °C and 150 MPa. Scanning electron microscopy in the back-scattered electron mode was used to characterize the microstructure's morphology. The respective phase fractions were determined by X-ray diffractometry. It could be shown that the creep resistance decreases with an increasing amount of discontinuous precipitation.
Quelques aspects des mutations contemporaines des campagnes françaises (Recent changes in the French countryside)
Authors: Renard Jean 
Published: May 2015

Résumé. - Les transformations du contenu social des campagnes, la remise en cause du modèle agricole intensif et productiviste, l'émergence de nouvelles fonctions dévolues à l'agriculture, ainsi que les fonctions des bourgs-centres et des petites villes aux dynamiques contrastées contribuent aux mutations des espaces ruraux.
Ces différents éléments du complexe rural agissent en interaction et expliquent la diversité des aspects et des situations.
« Jouer collectif » dans un territoire fragmenté
Authors: Maisetti Nicolas 
Published: May 2015

La candidature de Marseille-Provence au titre de Capitale européenne de la culture en 2013 sera interrogée pour comprendre les dynamiques actuelles de recomposition du pouvoir urbain au sein de ce territoire. On se demandera dans quelle mesure la séquence a constitué un tournant dans les interactions entre les élus et les acteurs économiques, en redistribuant les ressources d’autorité et en fondant un nouveau territoire d’action publique. À première vue, la domination des facteurs économiques sur la candidature tend à accréditer les résultats des travaux de la géographie urbaine néo-marxiste. Cependant, et conformément à la critique formulée par les approches de la gouvernance urbaine, les acteurs politiques n’ont pas été jusqu’à remettre les clés du pouvoir local aux animateurs de la chambre de commerce. Nuançant les conclusions de ces perspectives néo-institutionnalistes, en dépit des injonctions des acteurs privés, nous voudrions montrer que le « jouer collectif » n’a jamais pleinement fonctionné, ni permis de voir émerger un acteur territorial doté de capacités d’actions nouvelles. En somme, nous verrons que la division du travail politique qui a sous-tendu l’opération Capitale a certes recomposé les frontières de l’échange politique territorialisé, mais sans dépasser les conflits d’institution ou les luttes politiques structurantes du pouvoir urbain.
La capacité d’appropriation, une capacité organisationnelle immatérielle négligée dans l’adoption des systèmes d’information et de gestion
Authors: Ologeanu-Taddei Roxana , Gauche Karine , Morquin David , Bourret Rodolphe 
Published: May 2015

Notre article porte sur la capacité d’appropriation des systèmes d’information et de gestion (SIG). Celle-ci intègre la mise en place du soutien organisationnel pour définir des règles concertées d’indexation de l’information et d’utilisation tout en laissant aux utilisateurs l’autonomie pour leur adaptation. Nous montrons que la formalisation de cette capacité par les organisations est un aspect souvent négligé lors de l’implémentation de ces systèmes. Nous illustrons notre propos par deux études de cas, réalisées dans deux bureaucraties professionnelles publiques françaises. Dans les deux cas, nous constatons des sous-utilisations et des pratiques de contournement de SIG, témoignant d’une adoption subie et non d’une appropriation authentique des SIG. Nous expliquons ces résultats par le fait que l’appropriation ainsi que la capacité d’appropriation sont négligées, en raison notamment des coûts supplémentaires qu’elles induisent. Nous proposons d’éviter cette situation par l’intégration de la capacité d’appropriation dans l’actif immatériel de l’organisation. Codes JEL : J24, L23, M15
Capacité d’innovation du prestataire de services logistiques et performance logistique perçue par l’industriel : quelle relation dans le contexte vietnamien ?
Authors: Duong Huu Tuyen , Paché Gilles 
Published: May 2015

Le développement rapide des prestataires de services logistiques (PSL) est devenu une réalité dans de nombreux pays développés, mais également dans des économies en transition. Ils offrent aujourd’hui une large gamme de services à leurs clients, et ils font preuve d’une importante capacité d’innovation dans la création de nouveaux services à valeur ajoutée. La question est de savoir si leurs clients ont pris conscience que cette capacité d’innovation influence positivement leur performance logistique. Si tel était le cas, cela signifierait que les PSL les plus innovants sont en position favorable sur le marché, et qu’ils peuvent espérer une forte loyauté de leurs clients. L’article s’interroge sur le lien entre capacité d’innovation du PSL et performance logistique perçue par l’industriel, à partir des résultats d’une recherche conduite auprès de 139 industriels agro-alimentaires vietnamiens. Codes JEL : L66, L87, M10, R49
Pierre réconcilierait-il Luc et Jean?
Authors: Rastoin Marc 
Published: May 2015

Les points de contact entre les évangiles de Luc et de Jean ont été relevés depuis longtemps et ont intrigué les biblistes. Diverses tentatives ont essayé d’en rendre compte par le biais d’hypothèses touchant à l’histoire rédactionnelle des deux textes et à leurs liens littéraires éventuels. Aucun consensus ne s’est vraiment imposé ! Ceci témoigne d’un certain essoufflement de pareil angle d’approche, pourtant nécessaire. Mettre en lumière les ressemblances proprement théologiques, révélant les soucis communs des deux évangélistes, peut éclairer le moment ecclésial de leur écriture. Le traitement de la figure de Pierre le montre au premier chef.
Le ministère presbytéral : thèmes majeurs de la théologie espagnole postconciliaire (1971-2011)
Authors: del Cura Elena Santiago 
Published: May 2015

Cet article se propose de dresser un bilan de la théologie postconciliaire du ministère presbytéral dans l’Église espagnole durant la période de 1971 à 2011. L’auteur présente quelques thèmes majeurs de la réflexion en la matière et signale les points de possibles ou nécessaires développements ultérieurs : la place du presbytérat dans l’ensemble des ministères et charismes, la nature et la mission du ministère presbytéral, la sacramentalité de l’ordre dans ses divers degrés, l’intégration des différentes tâches ministérielles et les caractéristiques de la spiritualité presbytérale.
Diverse Inflammatory Cytokines Induce Selectin Ligand Expression on Murine CD4 T Cells via p38α MAPK
Authors: Ebel Mark E. , Awe Olufolakemi , Kaplan Mark H. , Kansas Geoffrey S. 
Published: May 2015

Abstract
Selectins are glycan-binding adhesion molecules that mediate the initial steps of leukocyte recognition of endothelium. Cytokines control numerous aspects of CD4 Th cell differentiation, but how cytokines control the induction of ligands for E- and P-selectin on Th cell subsets remains poorly understood. Among 20 cytokines that affect Th cell differentiation, we identified six that induce expression of selectin ligands on murine CD4 T cells above the low levels associated with TCR engagement: IL-12, IL-18, IL-27, IL-9, IL-25, and TGF-β1. Collectively, these six cytokines could potentially account for selectin ligand expression on all of the currently defined nonsessile Th cell lineages, including Th1, Th2, Th9, and Th17 cells, as well as regulatory T cells. Induction of selectin ligand expression by each of these six cytokines was almost completely inhibited by pharmacologic inhibition of p38 MAPK, but not other MAPKs, or by conditional genetic deletion of p38α MAPK. Analysis of the expression of key glycosyltransferase genes revealed that p38α signaling was selectively required for induction of Fut7 and Gcnt1 but not for the induction of St3gal4 or St3gal6. Constitutively active MKK6, an immediate upstream activator of p38 MAPK, induced selectin ligand expression equivalent to that of cytokines, and this induction was completely dependent on the expression of p38α. Our results identify the repertoire of cytokines responsible for selectin ligand induction on CD4 T cells and provide a mechanistic link between Th cell development and T cell migration.
IMPORTANCE OF CLASSICAL MORPHOLOGY IN THE DIAGNOSIS OF MYELODYSPLASTIC SYNDROME
Authors: Invernizzi Rosangela , Quaglia Federica , Della Porta Matteo Giovanni 
Published: May 2015

Myelodysplastic syndromes (MDS) are hematopoietic stem cell disorders characterized by dysplastic, ineffective, clonal and neoplastic hematopoiesis. MDS represent a complex hematological problem: differences in disease presentation, progression and outcome have necessitated the use of classification systems to improve diagnosis, prognostication and treatment selection. However, since a single biological or genetic reliable diagnostic marker has not yet been discovered for MDS, quantitative and qualitative dysplastic morphological alterations of bone marrow precursors and of peripheral blood cells are still fundamental for diagnostic classification. In this paper World Health Organization (WHO) classification refinements and current minimal diagnostic criteria proposed by expert panels are highlighted and related problematic issues are discussed. The recommendations should facilitate diagnostic and prognostic evaluations in MDS and selection of patients for new effective targeted therapies. Although in the future morphology should be supplemented with new molecular techniques, the morphological approach, at least for the moment, is still the cornerstone for the diagnosis and classification of these disorders.
Cervical cancer screening: Safety, acceptability, and feasibility of a single-visit approach in Bulawayo, Zimbabwe
Authors: Fallala Muriel S. , Mash Robert 
Published: May 2015

Background: Cervical cancer is the commonest cancer amongst African women, and yet preventative services are often inadequate.Aim: The purpose of the study was to assess the safety, acceptability and feasibility of visual inspection with acetic acid and cervicography (VIAC) followed by cryotherapy or a loop electrical excision procedure (LEEP) at a single visit for prevention of cancer of the cervix.Setting:The United Bulawayo Hospital, Zimbabwe.Methods: The study was descriptive, using retrospective data extracted from electronic medical records of women attending the VIAC clinic. Over 24 months 4641 women visited the clinic and were screened for cervical cancer using VIAC. Cryotherapy or LEEP was offered immediately to those that screened positive. Treated women were followed up at three months and one year.Results: The rate of positive results on VIAC testing was 10.8%. Of those who were eligible, 17.0% received immediate cryotherapy, 44.1% received immediate LEEP, 1.9% delayed treatment, and 37.0% were referred to a gynaecologist. No major complications were recorded after cryotherapy or LEEP. Amongst those treated 99.5% expressed satisfaction with their experience. Only 3.2% of those treated at the clinic had a positive result on VIAC one year later. The service was shown to be feasible to sustain over time with the necessary consumables. There were no service-related treatment postponements and the clinic staff and facility were able to meet the demand for the service.Conclusion: A single-visit approach using VIAC, followed by cryotherapy or LEEP, proved to be safe, acceptable and feasible in an urban African setting in Bulawayo, Zimbabwe. Outcomes a year later suggested that treatment had been effective.
Prediction of Early Breast Cancer Metastasis from DNA Microarray Data Using High-Dimensional Cox Regression Models
Authors: Zemmour Christophe , Bertucci François , Finetti Pascal , Chetrit Bernard , Birnbaum Daniel , Filleron Thomas , Boher Jean-Marie 
Published: May 2015

Background DNA microarray studies identified gene expression signatures predictive of metastatic relapse in early breast cancer. Standard feature selection procedures applied to reduce the set of predictive genes did not take into account the correlation between genes. In this paper, we studied the performances of three high-dimensional regression methods – CoxBoost, LASSO (Least Absolute Shrinkage and Selection Operator), and Elastic net – to identify prognostic signatures in patients with early breast cancer. Methods We analyzed three public retrospective datasets, including a total of 384 patients with axillary lymph node-negative breast cancer. The Amsterdam van't Veer's training set of 78 patients was used to determine the optimal gene sets and classifiers using sensitivity thresholds resulting in misclassification of no more than 10% of the poor-prognosis group. To ensure the comparability between different methods, an automatic selection procedure was used to determine the number of genes included in each model. The van de Vijver's and Desmedt's datasets were used as validation sets to evaluate separately the prognostic performances of our classifiers. The results were compared to the original Amsterdam 70-gene classifier. Results The automatic selection procedure reduced the number of predictive genes up to a minimum of six genes. In the two validation sets, the three models (Elastic net, LASSO, and CoxBoost) led to the definition of genomic classifiers predicting the 5-year metastatic status with similar performances, with respective 59, 56, and 54% accuracy, 83, 75, and 83% sensitivity, and 53, 52, and 48% specificity in the Desmedt's dataset. In comparison, the Amsterdam 70-gene signature showed 45% accuracy, 97% sensitivity, and 34% specificity. The gene overlap and the classification concordance between the three classifiers were high. All the classifiers added significant prognostic information to that provided by the traditional prognostic factors and showed a very high overlap with respect to gene ontologies (GOs) associated with genes overexpressed in the predicted poor-prognosis vs. good-prognosis classes and centred on cell proliferation. Interestingly, all classifiers reported high sensitivity to predict the 4-year status of metastatic disease. Conclusions High-dimensional regression methods are attractive in prognostic studies because finding a small subset of genes may facilitate the transfer to the clinic, and also because they strengthen the robustness of the model by limiting the selection of false-positive predictive genes. With only six genes, the CoxBoost classifier predicted the 4-year status of metastatic disease with 93% sensitivity. Selecting a few genes related to ontologies other than cell proliferation might further improve the overall sensitivity performance.
The inherent instability of leveed seafloor channels
Authors: Dorrell Robert M. , Burns Alan D. , McCaffrey William D. 
Published: May 2015

AbstractNew analytical models demonstrate that under aggradational flow conditions, seafloor channel‐levee systems are inherently unstable; both channel area and stability necessarily decrease at long timescales. In time such systems must avulse purely through internal (autogenic) forcing. Although autogenic instabilities likely arise over long enough time for additional allogenic forcing to be expected, channel‐levee sensitivity to variations in flow character depends on the prior degree of system evolution. Recalibrated modern Amazon Fan avulsion timings are consistent with this model, challenging accepted interpretations of avulsion triggering.