bluuebunny/crossref_metadata_2025_split huggingface dataset:
Different biomechanical design and ecophysiological strategies in juveniles of two liana species with contrasting growth habit
Authors: Chen Ya‐Jun , Bongers Frans , Zhang Jiao‐Lin , Liu Jin‐Yu , Cao Kun‐Fang 
Published: June 2014

• Premise of the study: Lianas constitute a major functional type in tropical zones. While some liana species start climbing immediately after germination (shade‐avoidance), others have a long self‐supporting phase (shade‐tolerance). The morphophysiological characteristics of these two growth habits are unknown.• Methods: We quantified growth traits, biomass allocation, mechanics, anatomy, and hydraulics for saplings of Ventilago calyculata (an immediate obligate climber) and Ziziphus attopensis (having a long self‐supporting phase), both in the family Rhamnaceae. The mechanics, anatomy, and hydraulics for the mature individuals of the two species were also evaluated.• Key results: In the juvenile stage, V. calyculata had a higher slenderness ratio, height growth rate, and photosynthetic rate but similar biomass growth rate compared with Z. attopensis. In contrast, Z. attopensis had a higher leaf area growth rate, specific leaf area, and leaf mass fraction. Ziziphus attopensis had stiffer, but less conductive stems than V. calyculata. Stem rigidity of saplings decreased from base to apex in Z. attopensis, but increased in V. calyculata. Both species had similar resistance to xylem embolism. However, the leaves of V. calyculata were able to resist greater water deficits. At the mature stage, wider and longer vessels emerged in the xylem, and both species increased stem specific conductivity and drought resistance in stems and leaves. Ventilago calyculata had significantly higher specific conductivity and was more drought tolerant than Z. attopensis.• Conclusions: The two lianas differed significantly in growth, biomass allocation, anatomy, mechanics, ecophysiology, and hydraulic properties in line with their growth habits and shade adaptation strategies.
Speciation via floral heterochrony and presumed mycorrhizal host switching of endemic butterfly orchids on the Azorean archipelago
Authors: Bateman Richard M. , Rudall Paula J. , Bidartondo Martin I. , Cozzolino Salvatore , Tranchida‐Lombardo Valentina , Carine Mark A. , Moura Mónica 
Published: June 2014

• Premise of the study: Most orchid species native to the Macaronesian islands reflect immigration from western Europe or North Africa followed by anagenesis. The only putative exception is the butterfly orchids (Platanthera) of the Azores, where three species apparently reflect at least one cladogenetic speciation event. This multidisciplinary study explores the origin, speciation, phenotypic, and genotypic cohesion of these Azorean species and their mainland relatives.• Methods: Plants of Platanthera from 30 localities spanning all nine Azorean islands were compared with those of four continental European relatives for 38 morphometric characters; substantial subsets were also analyzed for plastid microsatellites, and for nrITS of both the orchids and their mycorrhizae.• Key results: Although the three Azorean and four mainland species are all readily distinguished morphometrically using several floral characters, and hybridization appears rare, divergence in ITS and especially plastid sequences is small. Despite occupying similar laurisilva habitats, the Azorean species differ radically in the identities and diversity of their mycorrhizal partners; specialism apparently increases rarity.• Conclusions: Although morphological evidence suggests two invasions of the islands from NW Africa and/or SW Europe, ITS data imply only one. As the molecular data are unable to distinguish among the potential mainland ancestors, two scenarios of relationship are explored that imply different ancestors. Both scenarios require both anagenetic and cladogenetic speciation events, involving homoplastic shifts in overall flower size and (often substantial) changes in the relative dimensions of individual floral organs. Limited genotypic divergence among the three species compared with greater phenotypic divergence suggests comparatively recent speciation. Mycorrhizae may be the most critical factor dictating the respective ecological tolerances, and thus the relative frequencies, of these species. The recent IUCN Red‐List amalgamation of Azorean Platanthera taxa into a single species urgently requires reappraisal, as P. micrantha is an excellent indicator species of seminatural laurisilva forest and P. azorica is arguably Europe's rarest orchid.
Dynamic control of osmolality and ionic composition of the xylem sap in two mangrove species
Authors: López‐Portillo Jorge , Ewers Frank W. , Méndez‐Alonzo Rodrigo , Paredes López Claudia L. , Angeles Guillermo , Alarcón Jiménez Ana Luisa , Lara‐Domínguez Ana Laura , del Carmen Torres Barrera María 
Published: June 2014

• Premise of the study: Xylem sap osmolality and salinity is a critical unresolved issue in plant function with impacts on transport efficiency, pressure gradients, and living cell turgor pressure, especially for halophytes such as mangrove trees.• Methods: We collected successive xylem vessel sap samples from stems and shoots of Avicennia germinans and Laguncularia racemosa using vacuum and pressure extraction and measured their osmolality. Following a series of extractions with the pressure chamber, we depressurized the shoot and pressurized again after various equilibration periods (minutes to hours) to test for dynamic control of osmolality. Transpiration and final sap osmolality were measured in shoots perfused with deionized water or different seawater dilutions.• Key results: For both species, the sap osmolality values of consecutive samples collected by vacuum extraction were stable and matched those of the initial samples extracted with the pressure chamber. Further extraction of samples with the pressure chamber decreased sap osmolality, suggesting reverse osmosis occurred. However, sap osmolalities increased when longer equilibration periods after sap extraction were allowed. Analysis of expressed sap with HPLC indicated a 1:1 relation between measured osmolality and the osmolality of the inorganic ions in the sap (mainly Na+, K+, and Cl−), suggesting no contamination by organic compounds. In stems perfused with deionized water, the sap osmolality increased to mimic the native sap osmolality.• Conclusions: Xylem sap osmolality and ionic contents are dynamically adjusted by mangroves and may help modulate turgor pressure, hydraulic conductivity, and water potential, thus being important for mangrove physiology, survival, and distribution.
Cell differentiation and tissue formation in the unique fruits of devil's claws (Martyniaceae)
Authors: Horbens Melanie , Gao Jie , Neinhuis Christoph 
Published: June 2014

• Premise of the study: Martyniaceae are characterized by capsules with two upwardly curved, horn‐shaped extensions representing morphologically specialized epizoochorous fruits. Because the capsules are assumed to cling to hooves and ankles of large mammals, fiber arrangement and tissue combinations within the endocarp ensuring proper attachment to the vector's feet during transport are of particular interest. In this first detailed anatomical investigation, the functional adaptation of the fruits and their implications for the specific dispersal mode are provided. The peculiar fiber arrangement may also be of interest for future biomimetic composite materials.• Methods: Endocarp anatomy and details of tissue differentiation were examined in fruits of Ibicella lutea and Proboscidea louisianica subsp. fragrans combining light microscopy, SEM, and x‐ray microtomography analysis.• Key results: While tips of the extensions are predominantly reinforced by longitudinally oriented fibers, in the middle segment these fibers are densely packed in individual bundles entwined and separated by transversely elongated cells. Within the capsule wall, the fiber bundles are embedded in a dense mesh of transversely oriented fibers that circularly reinforce and protect the loculus. This fibrous pericarp tissue develops within few days by localized cell divisions and intrusive growth of primarily isodiametric parenchyma cells in the pistil.• Conclusions: The study allows insight into a unique and complex example of functionally driven cell growth and tissue formation. Long‐horned fruits of Martyniaceae obviously are highly specialized to epizoochorous dispersal, pointing to primary vector‐related seed dispersal. The highly ordered arrangement of fibers results in a great mechanical firmness.
Demographic variation across successional stages and their effects on the population dynamics of the neotropical palmEuterpe precatoria
Authors: Otárola Mauricio Fernández , Avalos Gerardo 
Published: June 2014

•Premise of the study:Environmental heterogeneity is a strong selective force shaping adaptation and population dynamics across temporal and spatial scales. Natural and anthropogenic gradients influence the variation of environmental and biotic factors, which determine population demography and dynamics. Successional gradients are expected to influence demographic parameters, but the relationship between these gradients and the species life history, habitat requirements, and degree of variation in demographic traits remains elusive.•Methods:We used the palmEuterpe precatoriato test the effect of successional stage on plant demography within a continuous population. We calculated demographic parameters for size stages and performed matrix analyses to investigate the demographic variation within primary and secondary forests of La Selva, Costa Rica.•Key results:We observed differences in mortality and recruitment of small juveniles between primary and secondary forests. Matrix models described satisfactorily the chronosequence of population changes, which were characterized by high population growth rate in disturbed areas, and decreased growth rate in old successional forests until reaching stability.•Conclusions:Different demographic parameters can be expressed in contiguous subpopulations along a gradient of successional stages with important consequences for population dynamics. Demographic variation superimposed on these gradients contributes to generate subpopulations with different demographic composition, density, and ecological properties. Therefore, the effects of spatial variation must be reconsidered in the design of demographic analyses of tropical palms, which are prime examples of subtle local adaptation. These considerations are crucial in the implementation of management plans for palm species within spatially complex and heterogeneous tropical landscapes.
Linking safe sites for recruitment with host‐canopy heterogeneity: The case of a parasitic plant, Viscum album subsp. austriacum (Viscaceae)
Authors: Mellado Ana , Zamora Regino 
Published: June 2014

• Premise of the study: Canopies are ecologically relevant compartments of forests. Multiple sources of heterogeneity interact within forest canopies due to their structural complexity, which exert major influences on the structure and composition of epiphyte communities. Here, we explore canopy environmental heterogeneity of a Mediterranean pine forest, identifying the key biotic and abiotic factors determining mistletoe (Viscum album subsp. austriacum) recruitment at coarse and fine spatial scales.• Methods: Through field experiments, we assessed the range of suitable host species for V. album subsp. austriacum (hereafter, V. a. austriacum). We characterized the variation in abiotic factors at a fine spatial scale on the host species. Finally, we examined the effects of biotic (predation) and abiotic (light, temperature) factors on the fate of mistletoe seeds and seedlings along host branches.• Key results: We confirmed the tight specificity of V. a. austriacum to pine species, in particular to P. nigra at the local scale. Biotic constraints increased toward the branch interior, with minor effects on apical locations due to the positive effect of pine‐needle coverage. Contrarily, abiotic constraints increased toward branch extremities, harming mistletoe seeds by encouraging their desiccation.• Conclusions: Biotic and abiotic variables exert a strong, nonrandom filter on V. album regeneration, resulting in recruitment hotspots at the periphery of the branches and sites with a high probability of recruitment failure at thicker and more exposed locations. The narrow range of suitable host species and the scarcity and spatially restricted recruitment hotspots for V. a. austriacum leads to the clumping of mistletoe populations at the finer spatial scale.
Comparative genetic structure betweenSedum ussurienseandS. kamtschaticum(Crassulaceae), two stonecrops co‐occurring on rocky cliffs
Authors: Chung Mi Yoon , López‐Pujol Jordi , Chung Myong Gi 
Published: June 2014

•Premise of the study:Geographic isolation due to discontinuities of suitable habitat may have significant effects on the genetic structure of plant populations. Even within a few kilometers, physical barriers to gene flow may lead to considerable genetic differentiation among populations.•Methods: Sedum ussurienseis a boreal species that in Korea occurs only in four valleys separated by mountain ranges in Juwangsan National Park and its vicinity (a range of ∼15 km). Its congenerS. kamtschaticum, by contrast, co‐occurs in the four valleys but also on the intervening mountains. Using 12 allozyme loci, we comparatively assessed genetic variability and structure in 12 population pairs of the two stonecrops.•Key results:While we found high and comparable levels of within‐population genetic variation for the two species, among‐population divergence was significantly higher inS. ussuriense(FST= 0.261 vs.FST= 0.165).Sedum ussuriensealso showed a much higher percentage of among‐valley variation (19%) thanS. kamtschaticum(4%).•Conclusions:High levels of genetic diversity in the twoSedumspecies are consistent with the previous hypothesis that mountains of the Korean Peninsula served as glacial refugia for many boreal species. Given that the two congeners have similar life‐history traits, the lower among‐population differentiation inS. kamtschaticumis attributable to its higher abundance and more continuous distribution in the study area. This study confirms the central role of geographic isolation in the genetic structure of plant species even at very small scales.
Bending properties of a macroalga: Adaptation of Peirce's cantilever test for in situ measurements of Laminaria digitata (Laminariaceae)
Authors: Henry Pierre‐Yves T. 
Published: June 2014

• Premise of the study: The mechanical properties of a plant are key variables governing the interaction between the plant and its environment. Thus, measuring variables such as the flexural rigidity (bending) of a plant element is necessary to understand and predict the plant–flow interaction. However, plant elements such as macrophyte blades can be relatively thin and flexible, thus difficult to characterize. Different adaptations of the classical 3‐point bending tests can also affect the interpretation of the flexural rigidity of an element. A simple, robust, method is newly applied to a biomaterial and validated here as an alternative to measure flexural rigidity of thin, flexible plant elements.• Methods: Based on a bending test procedure developed for the textile industry, an apparatus for in‐situ measurements was developed and compared with other normalized methods, then used in a field test on the blade of a marine macroalga (Laminaria digitata) to assess its suitability to measure the bending modulus of a biomaterial.• Key results: Results of the presented method on selected surrogate materials agree with a normalized cantilever method (ISO 9073‐7:1998) and 3‐point bending test (ISO 178:2010). Values determined for the bending moduli for blades of L. digitaria were in the typical range for algal material. The range of validity of the method is discussed.• Conclusion: By validating this method with existing norms, this study suggests a better approach to measure bending properties of different biomaterials in the field compared with more traditional bending tests and opens new possibilities.
Servir les pauvres. Oui, mais dites-moi : quels pauvres au juste ?
Authors: Nebel Mathias 
Published: June 2014

Si le service des pauvres est une constante de la Tradition chrétienne, les organismes chrétiens actuels sont contraints à la spécialisation. Nos connaissances modernes sur la pauvreté sont de plus en plus assurées. Nous analysons de plus en plus finement les systèmes et sous-systèmes de pauvreté entre le manque et l’excès. Amartya Sen a permis de renouveler l’approche. Quels choix sont à poser aujourd’hui pour les institutions caritatives chrétiennes ? Faut-il privilégier des types de pauvretés ou de pauvres ? Il s’agit bien pour elles de se souvenir de l’origine et donc de participer à l’action du Christ lui-même. En régime chrétien, on ne peut que distinguer efficacité et fécondité de l’action. Nous avons besoin d’une critériologie de choix pour mieux incarner l’option préférentielle pour les pauvres.
Le pape François. De la vocation prophétique à l'institution missionnaire
Authors: Defois Gérard 
Published: June 2014

Comment mesurer d’ores et déjà l’effet social de la première année de pontificat de François ? Un premier point : l’approche à la fois historique, subjective et interpersonnelle des pontificats de Benoît XVI et de François tranche avec l’intégrisme de la Fraternité S. Pie X. Primat de la relation et de l’humanisme personnaliste : le lien entre Jean-Paul II et François est aisé à faire. Pour autant, il est incontestable que François met fin aux symboles traditionnels de la monarchie pontificale. Les ostentations du pouvoir temporel ne l’intéressent pas. L’appareil d’Etat est ébranlé par la priorité missionnaire donnée aux périphéries. La formation religieuse du jésuite Bergoglio l’a poussé depuis longtemps à vivre une logique de dépossession contraire aux bénéfices temporels des séculiers. Les modalités d’action pastorale bougent. François change d’abord les esprits avant de toucher aux structures. L’Europe ne plus s’estimer propriétaire ! Ceci posé, bien des questions sont ouvertes, au sens où il est permis désormais de les ouvrir sans anticiper sur la réponse : éthique sexuelle à la faveur du prochain synode sur la famille, fonctionnement de la Curie comme quasi secrétariat de l’évêque de Rome, etc.
Les reconversions professionnelles dans l'artisanat d'art
Authors: Jourdain Anne 
Published: June 2014

Résumé Bénéficiant d’une profession socialement prestigieuse et bien rémunérée, un nombre croissant de cadres choisissent d’interrompre leur carrière professionnelle pour s’installer à leur compte en tant qu’artisans d’art. En se fondant essentiellement sur l’analyse d’entretiens biographiques, l’article rend compte de ces reconversions professionnelles « choisies » qui s’apparentent objectivement à une forme de déclassement. Il montre que la transition professionnelle vécue par ces cadres repose sur un double processus de désengagement et de réengagement, configurant une période enthousiasmante mais aussi angoissante du fait des irréversibilités qu’elle fait naître.
La malédiction du « Y'a qu'à former »
Authors: Allek Marnia 
Published: June 2014

Résumé L’inaptitude médicale peut être l’événement déclencheur d’une transition professionnelle. La reconversion vers un nouveau métier peut être facilitée par la formation, mais la mobilisation de ces salariés dits « en reclassement thérapeutique » n’est pas toujours simple. C’est pourquoi, la construction d’un dispositif de formation nécessite de penser les conditions de l’engagement des agents en formation, de réfléchir les conditions d’une reconnaissance des apprentissages ou des recompositions identitaires par les pairs et la hiérarchie, et enfin de considérer les dispositifs de gestion des ressources humaines comme des soutiens identitaires de ces transitions.
La Grèce, la crise et la sociologie
Authors: Constantopoulou Christiana 
Published: June 2014

Résumé Le texte qui suit propose un aperçu rapide de la sociologie dans la Grèce contemporaine. Cet article comporte également des « témoignages » de quelques sociologues grecs affrontant « la crise » dans leur vie quotidienne ainsi qu’une analyse de Constantin Tsoucalas.
Luminal Microbes Promote Monocyte–Stem Cell Interactions Across a Healthy Colonic Epithelium
Authors: Skoczek Dagmara A. , Walczysko Petr , Horn Nikki , Parris Alyson , Clare Simon , Williams Mark R. , Sobolewski Anastasia 
Published: June 2014

Abstract
The intestinal epithelium forms a vital barrier between luminal microbes and the underlying mucosal immune system. Epithelial barrier function is maintained by continuous renewal of the epithelium and is pivotal for gut homeostasis. Breaching of the barrier causes mobilization of immune cells to promote epithelial restitution. However, it is not known whether microbes at the luminal surface of a healthy epithelial barrier influence immune cell mobilization to modulate tissue homeostasis. Using a mouse colonic mucosal explant model, we demonstrate that close proximity of luminal microbes to a healthy, intact epithelium results in rapid mucus secretion and movement of Ly6C+7/4+ monocytes closer to epithelial stem cells. These early events are driven by the epithelial MyD88-signaling pathway and result in increased crypt cell proliferation and intestinal stem cell number. Over time, stem cell number and monocyte–crypt stem cell juxtapositioning return to homeostatic levels observed in vivo. We also demonstrate that reduced numbers of tissue Ly6C+ monocytes can suppress Lgr5EGFP+ stem cell expression in vivo and abrogate the response to luminal microbes ex vivo. The functional link between monocyte recruitment and increased crypt cell proliferation was further confirmed using a crypt–monocyte coculture model. This work demonstrates that the healthy gut epithelium mediates communication between luminal bacteria and monocytes, and monocytes can modulate crypt stem cell number and promote crypt cell proliferation to help maintain gut homeostasis.
The Inhibitory Effect of IFN-γ on Protease HTRA1 Expression in Rheumatoid Arthritis
Authors: Hou Yuzhu , Lin Haijiang , Zhu Linnan , Liu Zhaoting , Hu Fanlei , Shi Jianfeng , Yang Tao , Shi Xiaoyun , Guo Huifang , Tan Xiaotian , Zhang Lianfeng , Wang Qiang , Li Zhanguo , Zhao Yong 
Published: June 2014

Abstract
The high temperature requirement A1 (HTRA1) is a potent protease involved in many diseases, including rheumatoid arthritis (RA). However, the regulatory mechanisms that control HTRA1 expression need to be determined. In this study, we demonstrated that IFN-γ significantly inhibited the basal and LPS-induced HTRA1 expression in fibroblasts and macrophages, which are two major cells for HTRA1 production in RA. Importantly, the inhibitory effect of IFN-γ on HTRA1 expression was evidenced in collagen-induced arthritis (CIA) mouse models and in human RA synovial cells. In parallel with the enhanced CIA incidence and pathological changes in IFN-γ–deficient mice, HTRA1 expression in the joint tissues was also increased as determined by real-time PCR and Western blots. IFN-γ deficiency increased the incidence of CIA and the pathological severity in mice. Neutralization of HTRA1 by Ab significantly reversed the enhanced CIA frequency and severity in IFN-γ–deficient mice. Mechanistically, IFN-γ negatively controls HTRA1 expression through activation of p38 MAPK/STAT1 pathway. Dual luciferase reporter assay and chromatin immunoprecipitation analysis showed that STAT1 could directly bind to HTRA1 promoter after IFN-γ stimulation. This study offers new insights into the molecular regulation of HTRA1 expression and its role in RA pathogenesis, which may have significant impact on clinical therapy for RA and possibly other HTRA1-related diseases, including osteoarthritis, age-related macular degeneration, and cancer.