bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Multiechelon Inventory Problem with Secondary Market Sales
Authors: Angelus Alexandar 
Published: October 2011

We consider a finite-horizon, multiechelon inventory system in which the surplus of stock can be sold (i.e., disposed) in the secondary markets at each stage in the system. What are called nested echelon order-up-to policies are shown to be optimal for jointly managing inventory replenishments and secondary market sales. Under a general restriction on model parameters, we establish that it is optimal not to both sell off excess stock and replenish inventory. Secondary market sales complicate the structure of the system, so that the classical Clark and Scarf echelon reformulation no longer allows for the decomposition of the objective function under the optimal policy. We introduce a novel class of policies, referred to as the disposal saturation policies, and show that there exists a disposal saturation policy, determined recursively by a single base-stock level at each echelon, that achieves the decomposition of this problem. The resulting optimal replenishment policy is shown to be the echelon base-stock policy. We demonstrate the heuristic performance of this disposal saturation policy through a series of numerical studies: except at extreme ranges of model parameters, the policy provides a very good approximation to the optimal policy while avoiding the curse of dimensionality. We also conduct numerical studies to determine the value of the secondary markets for multistage supply chains and assess its sensitivity to model parameters. The results provide potentially useful insights for companies seeking to enter or develop secondary markets for supply chains. This paper was accepted by Martin Lariviere, operations management.
Bayesian Dynamic Pricing Policies: Learning and Earning Under a Binary Prior Distribution
Authors: Harrison J. Michael , Keskin N. Bora , Zeevi Assaf 
Published: October 2011

Motivated by applications in financial services, we consider a seller who offers prices sequentially to a stream of potential customers, observing either success or failure in each sales attempt. The parameters of the underlying demand model are initially unknown, so each price decision involves a trade-off between learning and earning. Attention is restricted to the simplest kind of model uncertainty, where one of two demand models is known to apply, and we focus initially on performance of the myopic Bayesian policy (MBP), variants of which are commonly used in practice. Because learning is passive under the MBP (that is, learning only takes place as a by-product of actions that have a different purpose), it can lead to incomplete learning and poor profit performance. However, under one additional assumption, a constrained variant of the myopic policy is shown to have the following strong theoretical virtue: the expected performance gap relative to a clairvoyant who knows the underlying demand model is bounded by a constant as the number of sales attempts becomes large. This paper was accepted by Gérard P. Cachon, stochastic models and simulation.
Constant Proportion Debt Obligations: A Postmortem Analysis of Rating Models
Authors: Gordy Michael B. , Willemann Søren 
Published: October 2011

In its complexity and its vulnerability to market volatility, the constant proportion debt obligation (CPDO) might be viewed as the poster child for the excesses of financial engineering in the credit market. This paper examines the CPDO as a case study in model risk in the rating of complex structured products. We demonstrate that the models used by Standard and Poor's (S&P) and Moody's fail in-sample specification tests even during the precrisis period and in particular understate the kurtosis of spread changes. Because stochastic volatility is the most natural explanation for the excess kurtosis, we estimate an extended version of the S&P model with stochastic volatility and find that the volatility-of-volatility is large and significant. An implication is that agency model-implied probabilities of attaining high spread levels were biased downward, which in turn biased the rating upward. We conclude with larger lessons for the rating of complex products and for modeling credit risk in general.This paper was accepted by Wei Xiong, finance.
On the Approximability of Single-Machine Scheduling with Precedence Constraints
Authors: Ambühl Christoph , Mastrolilli Monaldo , Mutsanas Nikolaus , Svensson Ola 
Published: October 2011

We consider the single-machine scheduling problem to minimize the weighted sum of completion times under precedence constraints. In a series of recent papers, it was established that this scheduling problem is a special case of minimum weighted vertex cover. In this paper, we show that the vertex cover graph associated with the scheduling problem is exactly the graph of incomparable pairs defined in the dimension theory of partial orders. Exploiting this relationship allows us to present a framework for obtaining (2-2/f)-approximation algorithms, provided that the set of precedence constraints has fractional dimension of at most f. Our approach yields the best-known approximation ratios for all previously considered special classes of precedence constraints, and it provides the first results for bounded degree and orders of interval dimension 2. On the negative side, we show that the addressed problem remains NP-hard even when restricted to the special case of interval orders. Furthermore, we prove that the general problem, if a fixed cost present in all feasible schedules is ignored, becomes as hard to approximate as vertex cover. We conclude by giving the first inapproximability result for this problem, showing under a widely believed assumption that it does not admit a polynomial-time approximation scheme.
Differences in the timing of germination and reproduction relate to growth physiology and population dynamics of Sonoran Desert winter annuals
Authors: Kimball Sarah , Angert Amy L. , Huxman Travis E. , Venable D. Lawrence 
Published: October 2011

• Premise of the Study: Trait differences can promote distinct survival and fecundity responses to environmental fluctuations. In a Sonoran Desert winter annual plant community, we have identified a tradeoff between relative growth rate (RGR) and water‐use efficiency (WUE) that predicts interannual variation in reproductive success. Here we test the hypothesis that traits underlying RGR and WUE differences are linked to seasonal phenology.• Methods: We use long‐term demographic data and finer‐scale, short‐term data to investigate timing of germination, reproduction, and death of several winter annual species in multiple years in open and under‐shrub habitats. We hypothesized that species with high WUE and less interannual demographic variability would have life cycle transitions early in the winter to spring growing season. This would be due to an ability to use small amounts of rain and photosynthesize at low temperatures. By contrast, we hypothesized that species with low WUE whose survival and reproductive rates vary greatly from year to year would have life cycle transitions later in the season.• Key Results: In any given year, species with high WUE germinated and reproduced earlier in the season than species with low WUE, whereas low‐WUE species germinated later and had shorter reproductive phases.• Conclusions: Our results demonstrate a direct relationship between phenology and physiological trait differences. This link between phenology and physiology is of interest because it clarifies the mechanism by which trait differences determine species’ relative abundances.
Importance of autonomous selfing is inversely related to population size and pollinator availability in a monocarpic plant
Authors: Brys Rein , de Crop Eske , Hoffmann Maurice , Jacquemyn Hans 
Published: October 2011

• Premise of the study: In animal‐pollinated plants, autonomous selfing may provide reproductive assurance when pollinators or reproductive partners are limited. Under such circumstances, the contribution of pollinator‐mediated seed set to total seed production also may be more variable compared with situations in which pollinator abundances are high or populations consist of large numbers of individuals. Despite the widespread acceptance of the reproductive assurance hypothesis, only limited empirical evidence exists that autonomous selfing confers reproductive output and guarantees constant seed set under variable pollination environments.• Methods: We performed emasculation experiments in 22 populations of the short‐lived, monocarpic plant Centaurium erythraea in a fragmented dune landscape.• Key results: Floral emasculations resulted in a significantly lower seed set compared with that of intact flowers. Seed set in emasculated flowers also declined significantly with decreasing population size and pollinator availability, whereas seed set of intact flowers did not depend on population size nor on pollinator availability. Variability in seed set among individuals was significantly lower in intact than in emasculated flowers and decreased significantly with increasing population size when flowers were emasculated but not in intact flowers.• Conclusions: These results indicate that pollinator‐mediated seed set is strongly dependent both on population size and on pollinator availability but that reproductive assurance through autonomous selfing guarantees relatively constant levels of total seed production, even when populations are small and/or pollinator limited. High variation in seed set of emasculated flowers suggests strong unpredictability in pollinator services in small populations.
Development and characterization of EST‐SSR markers in Paeonia suffruticosa (Paeoniaceae)
Authors: Hou Xiao‐Gai , Guo Da‐Long , Wang Juan 
Published: October 2011

• Premise of the study: Paeonia suffruticosa is one of the most famous flowering species in China. Ten simple sequence repeat (SSR) markers were developed and characterized from the expressed sequence tag (EST) database of tree peonies to be applied in genetic diversity studies.• Methods and Results: A total of 10 novel EST‐SSR loci were developed and characterized when tested on two populations of 45 tree peony individuals from China. The number of alleles per locus ranged from one to four and the expected heterozygosity ranged from 0.2087 to 0.6581. Select loci also amplified successfully in three other Paeonia species (P. ostii, P. rockii, P. jishanensis).• Conclusions: These markers will facilitate analysis of genetic diversity, population differentiation, and marker‐assisted breeding of Paeoniaceae.
Isolation of 16 polymorphic microsatellite markers from an endangered and endemic species, Podocarpus nakaii (Podocarpaceae)
Authors: Chiang Yu‐Chung , Shih Huei‐Chuan , Chang Li‐Wan , Li Wan‐Rung , Lin Huan‐Yu , Ju Li‐Ping 
Published: October 2011

• Premise of the study: Sixteen polymorphic microsatellite markers were isolated and characterized from the endangered evergreen tree Podocarpus nakaii to evaluate the population structure for conservation efforts.• Methods and Results: Based on a modified amplified fragment length polymorphism and magnetic bead enrichment method, 16 polymorphic primer sets were developed for this endangered insular species. Allele numbers ranged from five to seven, with an observed heterozygosity ranging from 0.29 to 0.88. Most primers were able to amplify DNA from the endemic P. fasciculus and the widely distributed P. macrophyllus var. macrophyllus, P. macrophyllus var. maki, and P. costalis.• Conclusions: The results reported here indicate the usefulness of codominant markers for future studies of the population genetics of P. nakaii. In addition, the markers are useful for further phytogeographic and speciation studies in P. fasciculus, P. macrophyllus var. macrophyllus, and P. macrophyllus var. maki, which are closely related species.
Mannose-binding Lectin Gene Polymorphisms in Brazilian Patients with Rheumatoid Arthritis
Authors: MARTINY FERNANDA LETICIA , VEIT TIAGO DEGANI , BRENOL CLAITON VIEGAS , BRENOL JOÃO CARLOS TAVARES , XAVIER RICARDO MACHADO , BOGO MAURÍCIO REIS , CHIES JOSÉ ARTUR BOGO 
Published: October 2011

Objective.Rheumatoid arthritis (RA) is a disease with unknown etiology but it is probably multifactorial. RA susceptibility is related to genetic, hormonal, immunologic, and environmental factors. Mannose-binding lectin (MBL) is an important protein of the human innate immune system, encoded by the MBL2 gene. Polymorphisms in MBL2 were associated with several diseases, and may be an important factor in RA susceptibility. We analyzed 3 MBL2 gene polymorphisms in 322 Brazilian patients with RA and 345 ethnically matched healthy controls.Methods.MBL2 gene variants were analyzed through polymerase chain reaction sequencing.Results.Considering MBL2 B, C, and D alleles separately, a significant difference in both genotypic and allelic frequencies, particularly concerning frequency of the C allele, was observed comparing European-derived and African-derived individuals (European-derived patients 0.022 vs African-derived patients 0.205; European-derived controls 0.029 vs African-derived controls 0.144; both p < 0.001). We also analyzed MBL2 genotype in relation to extraarticular manifestations. Considering MBL2 variants together, we found an increased frequency of the OO genotype among patients with rheumatoid nodules (p = 0.031), although this association lost significance after Bonferroni correction.Conclusion.Our findings suggest an association of MBL2 genotypes with some clinical manifestations of RA, but more studies are needed to clarify the actual role of MBL in RA.
Look Beyond the Disease Activity Score of 28 Joints (DAS28): Tender Points Influence the DAS28 in Patients with Rheumatoid Arthritis
Authors: TON EVELIEN , BAKKER MARIJE F. , VERSTAPPEN SUZANNE M.M. , ter BORG EVERT JAN , van ALBADA-KUIPERS IET A. , SCHENK YOLANDE , van der VEEN MAAIKE J. , BIJLSMA JOHANNES W.J. , JACOBS JOHANNES W.G. 
Published: October 2011

Objective.To explore the influence of tender points (TP) on the Disease Activity Score assessing 28 joints (DAS28) in patients with rheumatoid arthritis (RA).Methods.In 200 consecutive patients with RA from the outpatient clinic, DAS28 and its components, tender and swollen joint counts (TJC, SJC, respectively), visual analog scale (VAS) for patient’s general health (GH), and erythrocyte sedimentation rate (ESR), along with a tender point count (TPC) were assessed. Patients were categorized according to 4 TPC classes: zero, 1–5, 6–10, and ≥ 11 TP. The influence of TPC classes on DAS28 and its individual components was determined with Kruskal-Wallis tests and correlations between TP and DAS28 and its components were calculated.Results.In 196 eligible patients, 70% were female, mean age was 59 years, and median disease duration was 3.9 years; median DAS28 was 3.1; and 49% had active disease, defined as DAS28 > 3.2. In 15% of patients, the TPC was ≥ 11, in 12% 6–10, in 30% 1–5, and in 43% zero. TPC significantly influenced the DAS28 and its less objective components TJC and VAS-GH (i.e., based on patient’s report), but not the more objective DAS28 components SJC and ESR (i.e., observer- and laboratory-based).Conclusion.DAS28 is influenced by tender points, even in the non-fibromyalgia range, falsely suggesting higher disease activity and decreasing the sensitivity of the DAS28 criterion of low disease activity or remission. When applying DAS28-guided “tight control” or “treat-to-target” treatment strategies in RA, evaluation of not only the DAS28, but also its individual components along with a full joint and physical evaluation including assessment of TP is required to reliably estimate the individual’s disease activity, which guides therapeutic decisions.
Synovial Infiltration with CD79a-positive B Cells, But Not Other B Cell Lineage Markers, Correlates with Joint Destruction in Rheumatoid Arthritis
Authors: MO YING-QIAN , DAI LIE , ZHENG DONG-HUI , ZHU LANG-JING , WEI XIU-NING , PESSLER FRANK , SHEN JUN , ZHANG BAI-YU 
Published: October 2011

Objective.The efficacy of B cell depletion in the treatment of patients with rheumatoid arthritis (RA) has revitalized interest in the pathogenic role(s) of B cells in RA. We evaluated the distribution of synovial B lineage cells and their correlation with histologic disease activity and joint destruction in RA.Methods.Synovial tissue samples were obtained by closed-needle biopsy from 69 Chinese patients with active RA, from 14 patients with osteoarthritis (OA), and from 15 with orthopedic arthropathies (OrthA) as disease controls. Serial tissue sections were stained immunohistochemically for CD79a (pro-B cell to plasma cell), CD20 (B cells), CD38 (plasma cells), CD21 (follicular dendritic cells), CD68 (macrophages), CD3 (T cells), and CD34 (endothelial cells). Densities of positive-staining cells were determined and correlated with histologic disease activity (Krenn 3-component synovitis score) and radiographic joint destruction (Sharp score).Results.Mean sublining CD79a-positive cell density was significantly higher in RA than in OA (p <0.001) or OrthA (p = 0.003). Receiver operating characteristic curve analysis showed that CD79a-positive cell density differentiated RA well from OA [area under the curve (AUC) = 0.79] or OrthA (AUC = 0.75). Spearman’s rank order correlation showed significant correlations between sublining CD79a-positive cell density and the synovitis score (r = 0.714, p < 0.001), total Sharp score (r = 0.490, p < 0.001), and the erosion subscore (r = 0.545, p < 0.001), as well as the joint space narrowing subscore (r = 0.468, p = 0.001) in RA.Conclusion.Synovial CD79a-positive B cells may be a helpful biomarker for histologic disease activity in RA and may be involved in the pathogenesis of joint destruction in RA.
Mourir et tuer pour de faux
Authors: Tisseron Serge 
Published: October 2011

Résumé Si l’acte de tuer est souvent présent dans les jeux vidéo, il prend une signification bien différente selon qu’il est intégré dans une narration ou pas. Mais parallèlement à l’acte de tuer, le joueur est aussi invité à expérimenter sa propre mort. Pour certains, il ne s’agit que d’un accident dans leur parcours initiatique, mais pour d’autre, c’est l’occasion de mettre en scène leur propre disparition, voire de mettre à mort des parties d’eux-mêmes dont ils ont envie de se débarrasser... y compris parfois leur désir de mourir !
Mort et cinéma : une dialectique du vide
Authors: Lecomte Kevin 
Published: October 2011

Résumé Le cinéma naît d’un cadre vide. Le cinéaste pioche dans la réalité, y intègre un espace, puis faire entrer l’élément humain. Ce nouvel espace-temps devient un lieu de vie propre, qui, à travers nous, agit comme une autre réalité, mais cloi- sonnée. Ainsi, tout ce qui est hors-cadre est inexistant, comme mort. Alors que se passe-t-il justement quand le cinéma traite de cette inconnue qu’est la mort ? Et bien il lui donne sens. La mort au cinéma est une réponse, une image du vide. À travers mon premier court métrage, j’ai tenté de le faire parler...
Le paradigme du déni social de la mort à l'épreuve des séries télévisées. Mise en scène et mise en sens de la mort
Authors: Julier-Costes Martin 
Published: October 2011

Résumé À l’inverse des thèses du déni social de la mort encore dominantes aujourd’hui, cet article démontre que les séries télévisées sont des tentatives de mise en sens de la mort. L’analyse d’une quinzaine d’entre elles a permis d’identifier des figures de la mort contemporaine. Classées en deux groupes : les experts et les intermédiaires, ces figures révèlent des lieux et des personnes d’une société certes scientifique et technicienne mais qui, par ailleurs, ne peut s’empêcher d’interroger la mort.
Programmation de la recherche : perspectives conceptuelles, institutionnelles et... actuelles
Authors: Barré Rémi 
Published: October 2011

Résumé On définit d’abord les trois fonctions d’un système national de recherche : orientation, programmation et recherche. Dans un second temps, on définit les deux grandes configurations possibles des systèmes de recherche selon le degré d’intégration – séparation des fonctions, en particulier des fonctions programmation et recherche (rôle important des organismes de recherche versus rôle important des agences de financement et des universités) ; on montre et on explique les différences entre les pays de ce point de vue et on caractérise chaque modèle. On présente alors le cas de la France, constitué depuis l’après seconde guerre mondiale sur le modèle à dominante intégrée ; on montre les succès de cette approche mais les interrogations qu’elle soulève depuis les années 1990, compte tenu de la montée en puissance des universités, de l’évolution des dynamiques de la recherche (pluridisciplinarité), des nécessité de lisibilité et de l’émergence de l’Espace européen de la recherche. On arrive alors aux réformes des années 2005-2008, qui tendent à faire évoluer, potentiellement, le système français vers le modèle à fonctions séparées. On évoque en conclusion, sous forme de scénario, les évolutions possibles des rapports entre universités et organismes de recherche. Codes JEL : I23, I28, O38
Programmer la recherche : facile mais... impossible
Authors: Claessens Michel 
Published: October 2011

Résumé Programmer la recherche est une idée relativement récente, du moins à grande échelle, que l’on peut dater avec précision. Dans cet article, nous abordons quelques aspects de cette thématique, en particulier le rôle des scientifiques, la contribution des programmes européens et la programmation de la recherche au niveau politique. Nous terminons par quelques réflexions sur le contrôle social et sociétal de la technoscience pour conclure par cette question qui figure au centre du développement technoscientifique : contrôler la marche du progrès a-t-il un sens ? Et pour aller dans quel sens ? Dans une société qui repose aussi étroitement (et aussi peu démocratiquement) sur la science et la technologie, notre seule marge de manœuvre se réduit-elle à anticiper l’évolution technoscientifique et à nous adapter à celle-ci ? Codes JEL : O20, O30, O31, O32, O33, O38
L'impact des critères de sélection des programmes de financement sur les pratiques scientifiques
Authors: Tricoire Aurélie 
Published: October 2011

Résumé	Cet article montre comment l’attribution compétitive des ressources dans le secteur de la recherche accentue la différenciation qualitative entre les équipes, au niveau de la solidité expérimentale des résultats produits, de la qualité de la formation du personnel et de la visibilité au sein d’une communauté disciplinaire. La mise en concurrence affecte aussi bien les individus, les collectifs que les projets, influençant les carrières, les réseaux et les contenus scientifiques. Percer les secrets du système compétitif d’allocation des ressources constitue un enjeu important pour un chercheur mais cela nécessite d’y consacrer du temps. En effet, il faut, d’une part, connaître aussi précisément que possible les processus d’évaluation, et, d’autre part, s’inscrire dans une logique de guichets multiples qui permet aux porteurs de projet de diversifier leurs chances d’être financés en développant un portefeuille de projets. Cette double assurance – affinement du contenu du projet et multiplication des demandes – répond à la forte incertitude qui demeure quant à l’accueil qui sera réservé à chacune des demandes formulées et qui dépend de la qualité relative des projets concurrents reçus par un même financeur. Ces nécessités de plus en plus pesantes réorganisent jusque dans ses activités quotidiennes le métier de chercheur. Le fonctionnement des équipes est modifié, dans le sens du renforcement de la division du travail ; les contenus scientifiques sont réorientés afin de les adapter aux préoccupations des bailleurs de fonds ; les réseaux scientifiques sont mobilisés afin de répondre aux critères de sélection. L’existence d’un lien entre modes d’attribution des financements et pratiques professionnelles quotidiennes des chercheurs nous amène donc à réinterroger la définition du terme de pratiques scientifiques.	Codes JEL : O22, O31, O32, O39