bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methane seep ecosystem functions and services from a recently discovered southern California seep
Authors: Grupe Benjamin M. , Krach Monika L. , Pasulka Alexis L. , Maloney Jillian M. , Levin Lisa A. , Frieder Christina A. 
Published: August 2015

AbstractThe recent discovery of a methane seep with diverse microhabitats and abundant groundfish in the San Diego Trough (1020 m) off the coast of Del Mar, California raised questions about the role of seep ecosystem functions and services in relation to continental margins. We used multicorer and ROV grab samples and an ROV survey to characterize macrofaunal structure, diversity, and trophic patterns in soft sediments and authigenic carbonates; seep microhabitats and taxa observed; and the abundance and spatial patterns of fishery‐relevant species. Biogenic microhabitats near the Del Mar Seep included microbially precipitated carbonate boulders, bacterial mats, vesicomyid clam beds, frenulate and ampharetid beds, vestimentiferan tubeworm clumps, and fields of Bathysiphon filiformis tubes. Macrofaunal abundance increased and mean faunal δ13C signatures decreased in multicorer samples nearer the seep, suggesting that chemosynthetic production enhanced animal densities outside the seep center. Polychaetes dominated sediments, and ampharetids became especially abundant near microbial mats, while gastropods, hydroids, and sponges dominated carbonate rocks. A wide range of stable isotopic signatures reflected the diversity of microhabitats, and methane‐derived carbon was the most prevalent source of nutrition for several taxa, especially those associated with carbonates. Megafaunal species living near the seep included longspine thornyhead (Sebastolobus altivelis), Pacific dover sole (Microstomus pacificus), and lithodid crabs (Paralomis verrilli), which represent targets for demersal fisheries. Sebastolobus altivelis was especially abundant (6.5–8.2 fish·100 m−2) and appeared to aggregate near the most active seep microhabitats. The Del Mar Methane Seep, like many others along the world's continental margins, exhibits diverse ecosystem functions and enhances regional diversity. Seeps such as this one may also contribute ecosystem services if they provide habitat for fishery species, export production to support margin food webs, and serve as sinks for methane‐derived carbon.
Bivalve populations inhabiting hydrothermal vents on submarine volcanoes: using size frequency distributions to infer potential regulatory factors
Authors: Metaxas Anna 
Published: August 2015

AbstractIn this study, I used length frequency distributions of bivalve populations at hydrothermal vents on submarine volcanoes at the South Tonga Arc and the Valu Fa Ridge to infer processes that may be responsible for the observed population structures. On Volcano 19, the lucinid Bathyaustriella thionipta co‐occurred with the sea star Rumbleaster eructans at two sedimented sites. At one site, live clams were significantly smaller (in shell length, SL) than dead ones (showing signs of predation by sea stars), whereas at the other site, both, live and dead clams had similarly small SL, suggesting a size refuge from predation. At Volcano 1, mussel beds of Bathymodiolus sp. were present in two areas: one with vigorous hydrothermal discharge (‘Bubbles’), and another with some discharge but also in the photic zone (‘Barracuda’). Mussels were smaller in SL at ‘Bubbles’ than at ‘Barracuda’, a consequence of either a younger population or a nutritionally less favourable environment at ‘Bubbles’. At ‘Barracuda’, mussels utilized both chemo‐ and photosynthetically derived carbon, possibly allowing them to reach larger sizes. At Hine Hina on Valu Fa Ridge, a population of mussels was composed mainly of large individuals (>55 mm SL), estimated to be on average 7–13 years old. The combination of old mussels, absence of recruits, and presence of abundant empty mussel shells and of dead chimneys suggests that this is a waning hydrothermal system. My results indicate that the population structure of bivalves at hydrothermal vents can provide information on the processes that regulate these populations, which in turn can be used to generate testable hypotheses for the same location, should return visits occur, or for other locations with similarly structured populations.
How are microbial and detrital sources partitioned among and within gastropods species at East Pacific Rise hydrothermal vents?
Authors: Gaudron Sylvie M. , Marqué Lise , Thiébaut Eric , Riera Pascal , Duperron Sébastien , Zbinden Magali 
Published: August 2015

AbstractFor the last few decades, trophic ecology has usually been investigated by using stable isotopes. However, the isotopic signatures of potential food sources in hydrothermal vent ecosystems are often unknown and so their relative contribution to the consumers’ diet, as well as resource partitioning, are then difficult to estimate. Here, we used a recent Bayesian mixing model (stable isotope analysis in R, SIAR) based on δ13C and δ15N to estimate the contribution of multiple food sources to the diet of eight vent gastropods that can reach high densities at hydrothermal vents (Lepetodrilus elevatus, Lepetodrilus pustulosus, Lepetodrilus ovalis, Eulepetopsis vitrea, Cyathermia naticoides, Peltospira delicata, Peltospira operculata and Rhynchopelta concentrica). These species, known as primary consumers (mostly bacterivores and detritivores), were sampled on the South‐East Pacific Rise at 17°25′ S and the North‐East Pacific Rise at 9°50′ N and 12°50′ N. Several potential food sources were sampled according to the gastropod habitat on the chimney wall, or mussel beds (proxies of Gammaproteobacteria form I RubisCO, Gammaproteobacteria form II RubisCO and Epsilonproteobacteria, biofilms of siboglinid and alvinellid tubes, biofilms of mussel shells and particulate organic matter). Some of these microbial and detrital sources were confirmed as present in the gut content of some small specimens by transmission electron microscopy. Distinct stable isotopic signatures of the potential food sources allowed calculation of their relative contributions to primary consumers’ diets. This revealed that gastropod species living on siboglinid or bathymodiolin habitats are usually generalists, feeding on various pools of microbial or detrital origins. For a particular habitat, sympatric gastropod species partition the food sources, thus avoiding being in competition. Only for the alvinellid habitat Peltospira spp. appeared to be more specialists as the choice of food sources is more reduced.
Genetic diversity and distribution patterns of diploid and polyploid hybrid water frog populations (Pelophylax esculentus complex) across Europe
Authors: Hoffmann Alexandra , Plötner Jörg , Pruvost Nicolas B. M. , Christiansen Ditte G. , Röthlisberger Sandra , Choleva Lukáš , Mikulíček Peter , Cogălniceanu Dan , Sas‐Kovács István , Shabanov Dmitry , Morozov‐Leonov Svyatoslav , Reyer Heinz‐Ulrich 
Published: August 2015

AbstractPolyploidization is a rare yet sometimes successful way for animals to rapidly create geno‐ and phenotypes that may colonize new habitats and quickly adapt to environmental changes. In this study, we use water frogs of the Pelophylax esculentus complex, comprising two species (Pelophylax lessonae, genotype LL; Pelophylax ridibundus, RR) and various diploid (LR) and triploid (LLR, LRR) hybrid forms, summarized as P. esculentus, as a model for studying recent hybridization and polyploidization in the context of speciation. Specifically, we compared the geographic distribution and genetic diversity of diploid and triploid hybrids across Europe to understand their origin, maintenance and potential role in hybrid speciation. We found that different hybrid and parental genotypes are not evenly distributed across Europe. Rather, their genetic diversity is structured by latitude and longitude and the presence/absence of parental species but not of triploids. Highest genetic diversity was observed in central and eastern Europe, the lowest in the northwestern parts of Europe. This gradient can be explained by the decrease in genetic diversity during postglacial expansion from southeastern glacial refuge areas. Genealogical relationships calculated on the basis of microsatellite data clearly indicate that hybrids are of multiple origin and include a huge variety of parental genomes. Water frogs in mixed‐ploidy populations without any parental species (i.e. all‐hybrid populations) can be viewed as evolutionary units that may be on their way towards hybrid speciation. Maintenance of such all‐hybrid populations requires a continuous exchange of genomes between diploids and triploids, but scenarios for alternative evolutionary trajectories are discussed.
SCR96, a small cysteine‐rich secretory protein of Phytophthora cactorum, can trigger cell death in the Solanaceae and is important for pathogenicity and oxidative stress tolerance
Authors: Chen Xiao‐Ren , Li Yan‐Peng , Li Qi‐Yuan , Xing Yu‐Ping , Liu Bei‐Bei , Tong Yun‐Hui , Xu Jing‐You 
Published: August 2015

SummaryPeptides and small molecules produced by both the plant pathogen Phytophthora and host plants in the apoplastic space mediate the relationship between the interplaying organisms. Various Phytophthora apoplastic effectors, including small cysteine‐rich (SCR) secretory proteins, have been identified, but their roles during interaction remain to be determined. Here, we identified an SCR effector encoded by scr96, one of three novel genes encoding SCR proteins in P. cactorum with similarity to the P. cactorum phytotoxic protein PcF. Together with the other two genes, scr96 was transcriptionally induced throughout the developmental and infection stages of the pathogen. These genes triggered plant cell death (PCD) in the Solanaceae, including Nicotiana benthamiana and tomato. The scr96 gene did not show single nucleotide polymorphisms in a collection of P. cactorum isolates from different countries and host plants, suggesting that its role is essential and non‐redundant during infection. Homologues of SCR96 were identified only in oomycetes, but not in fungi and other organisms. A stable protoplast transformation protocol was adapted for P. cactorum using green fluorescent protein as a marker. The silencing of scr96 in P. cactorum caused gene‐silenced transformants to lose their pathogenicity on host plants and these transformants were significantly more sensitive to oxidative stress. Transient expression of scr96 partially recovered the virulence of gene‐silenced transformants on plants. Overall, our results indicate that the P. cactorum scr96 gene encodes an important virulence factor that not only causes PCD in host plants, but is also important for pathogenicity and oxidative stress tolerance.
Guard cell hydrogen peroxide and nitric oxide mediate elevated CO2‐induced stomatal movement in tomato
Authors: Shi Kai , Li Xin , Zhang Huan , Zhang Guanqun , Liu Yaru , Zhou Yanhong , Xia Xiaojian , Chen Zhixiang , Yu Jingquan 
Published: August 2015

Summary

Climate change as a consequence of increasing atmospheric CO2 influences plant photosynthesis and transpiration. Although the involvement of stomata in plant responses to elevated CO2 has been well established, the underlying mechanism of elevated CO2‐induced stomatal movement remains largely unknown.

We used diverse techniques, including laser scanning confocal microscopy, transmission electron microscopy, biochemical methodologies and gene silencing to investigate the signaling pathway for elevated CO2‐induced stomatal movement in tomato (Solanum lycopersicum).

Elevated CO2‐induced stomatal closure was dependent on the production of RESPIRATORY BURST OXIDASE 1 (RBOH1)‐mediated hydrogen peroxide (H2O2) and NITRATE REDUCTASE (NR)‐mediated nitric oxide (NO) in guard cells in an abscisic acid (ABA)‐independent manner. Silencing of OPEN STOMATA 1 (OST1) compromised the elevated CO2‐induced accumulation of H2O2 and NO, upregulation of SLOW ANION CHANNEL ASSOCIATED 1 (SLAC1) gene expression and reduction of stomatal aperture, whereas silencing of RBOH1 or NR had no effects on the expression of OST1.

Our results demonstrate that as critical signaling molecules, RBOH1‐dependent H2O2 and NR‐dependent NO act downstream of OST1 that regulate SLAC1 expression and elevated CO2‐induced stomatal movement. This information is crucial to deepen the understanding of CO2 signaling pathway in guard cells.
Photosynthetic traits of Siebold's beech seedlings in changing light conditions by removal of shading trees under elevated CO2
Authors: Watanabe M. , Kitaoka S. , Eguchi N. , Watanabe Y. , Satomura T. , Takagi K. , Satoh F. , Koike T. 
Published: August 2015

AbstractThe purpose of this study was to obtain basic information on acclimation capacity of photosynthesis in Siebold's beech seedlings to increasing light intensity under future elevated CO2 conditions. We monitored leaf photosynthetic traits of these seedlings in changing light conditions (before removal of shade trees, the year after removal of shade trees and after acclimation to open conditions) in a 10‐year free air CO2 enrichment experiment in northern Japan. Elevated CO2 did not affect photosynthetic traits such as leaf mass per area, nitrogen content and biochemical photosynthetic capacity of chloroplasts (i.e. maximum rate of carboxylation and maximum rate of electron transport) before removal of the shade trees and after acclimation to open conditions; in fact, a higher net photosynthetic rate was maintained under elevated CO2. However, in the year after removal of the shade trees, there was no increase in photosynthesis rate under elevated CO2 conditions. This was not due to photoinhibition. In ambient CO2 conditions, leaf mass per area and nitrogen content were higher in the year after removal of shade trees than before, whereas there was no increase under elevated CO2 conditions. These results indicate that elevated CO2 delays the acclimation of photosynthetic traits of Siebold's beech seedlings to increasing light intensity.
Reconstructing fluvial bar surfaces from compound cross‐strata and the interpretation of bar accretion direction in large river deposits
Authors: Almeida Renato P. , Freitas Bernardo T. , Turra Bruno B. , Figueiredo Felipe T. , Marconato André , Janikian Liliane 
Published: August 2015

AbstractThe interpretation of fluvial styles from the rock record is based for a significant part on the identification of different types of fluvial bars, characterized by the geometric relationship between structures indicative of palaeocurrent and surfaces interpreted as indicative of bar form and bar accretion direction. These surfaces of bar accretion are the boundaries of flood‐related bar increment elements, which are typically less abundant in outcrops than what would be desirable, particularly in large river deposits in which each flood mobilizes large volumes of sediment, causing flood‐increment boundary surfaces to be widely spaced. Cross‐strata set boundaries, on the other hand, are abundant and indirectly reflect the process of unit bar accretion, inclined due to the combined effect of the unit bar surface inclination and the individual bedform climbing angle, in turn controlled by changes in flow structure caused by local bar‐scale morphology. This work presents a new method to deduce the geometry of unit bar surfaces from measured pairs of cross‐strata and cross‐strata set boundaries. The method can be used in the absence of abundant flood‐increment bounding surfaces; the study of real cases shows that, for both downstream and laterally accreting bars, the reconstructed planes are very similar to measured bar increment surfaces.
GI Expertise
Authors: Duckham Matt 
Published: August 2015

AbstractThis article concerns the identification of the expertise that GI scientists have in common. Rather than attempt to be exhaustive, the approach is to identify a minimal set of expert topics shared across GI science. In this article, a set of five expert topics is proposed for this purpose: structure, uncertainty, dynamism, language and cognition, and design with geographic information. The article then examines the extent to which the literature lends support for these five topics, using two analyses: first, a qualitative analysis of the papers found in the 2006 Classics from IJGIS; and second a citation analysis investigating the occurrences of keywords related to the proposed expert topics. The results suggest that these five areas of expertise do indeed tend to distinguish research in GI science from that in other fields, and in particular where the expert topics occur in combination. The establishment of an acknowledged core of shared expertise should assist in interdisciplinary research and teaching collaboration, usually founded on a shared understanding of what expertise different partners can contribute.
Insect herbivory elicits genome‐wide alternative splicing responses in Nicotiana attenuata
Authors: Ling Zhihao , Zhou Wenwu , Baldwin Ian T. , Xu Shuqing 
Published: August 2015

SummaryChanges in gene expression and alternative splicing (AS) are involved in many responses to abiotic and biotic stresses in eukaryotic organisms. In response to attack and oviposition by insect herbivores, plants elicit rapid changes in gene expression which are essential for the activation of plant defenses; however, the herbivory‐induced changes in AS remain unstudied. Using mRNA sequencing, we performed a genome‐wide analysis on tobacco hornworm (Manduca sexta) feeding‐induced AS in both leaves and roots of Nicotiana attenuata. Feeding by M. sexta for 5 h reduced total AS events by 7.3% in leaves but increased them in roots by 8.0% and significantly changed AS patterns in leaves and roots of existing AS genes. Feeding by M. sexta also resulted in increased (in roots) and decreased (in leaves) transcript levels of the serine/arginine‐rich (SR) proteins that are involved in the AS machinery of plants and induced changes in SR gene expression that were jasmonic acid (JA)‐independent in leaves but JA‐dependent in roots. Changes in AS and gene expression elicited by M. sexta feeding were regulated independently in both tissues. This study provides genome‐wide evidence that insect herbivory induces changes not only in the levels of gene expression but also in their splicing, which might contribute to defense against and/or tolerance of herbivory.
Serial ADAMTS13 measurements during initial plasma exchange therapy guide decisions for management of unresponsive thrombotic thrombocytopenic purpura
Authors: van der Veen Betty S. , Besseling Rens , Hoogendoorn Mels 
Published: August 2015

BACKGROUNDThe standard therapy in acquired thrombotic thrombocytopenic purpura (TTP) is plasma exchange. In unresponsive TTP, intensification of plasma exchange and immunomodulatory therapy can be initiated but it can be complicated to select for patients that will benefit from intensification.CASE REPORTWe describe two cases of newly diagnosed TTP with a complicated clinical course during initial treatment with plasma exchange. In one case, after an initial response to plasma exchange, a decrease in platelet count was observed on Day 7. The normalized ADAMTS13 activity guided the clinicians in the diagnosis of a concurrent heparin‐induced thrombocytopenia due to the heparin lock, used for the indwelling catheter. The other case with TTP clinically deteriorated early during initial treatment. Reevaluation on Day 5, including ADAMTS13 activity, which was undetectably low, supported the clinical decision to intensify the plasma exchange to twice daily and start with the immunomodulating agent rituximab. In both clinically complicated cases measurements of ADAMTS13 activity during plasma exchange proved to be useful in guiding treatment decisions.CONCLUSIONSerial measurements of ADAMTS13 activity should be considered in patients with newly diagnosed TTP with an unpredictable clinical course during initial therapeutic plasma exchange. These measurements may provide pivotal clinical insights on appropriate patient management.
Do Multinationals Deteriorate Developing Countries' Export Prices? The Impact of FDI on Net Barter Terms of Trade
Authors: Wacker Konstantin M. 
Published: August 2015

AbstractThis paper explores the economic relationship between foreign direct investment to developing countries and the export prices of the latter, measured by terms of trade. It is first shown that economic theory suggests such a relationship for various reasons but is inconclusive about the direction of the effect. To address this open issue empirically, I analyse data on more than 50 developing countries throughout the period 1980–2008 using robust dynamic panel data methods. The results show that FDI had an economically relevant and statistically significant positive impact on developing countries' net barter terms of trade. A higher level of education in the developing country fosters this effect.
Morphological and genetic differentiation of Eremina desertorum (Gastropoda, Pulmonata, Helicidae) in Egypt
Authors: Ali Reham F. , Neiber Marco T. , Walther Frank , Hausdorf Bernhard 
Published: August 2015

To understand the processes that result in morphological and genetic diversity, we studied the differentiation of the land snails Eremina d. desertorum and Eremina desertorum irregularis in the deserts of northern Egypt. These two taxa are differentiated with regard to shell size and shape and are separated by a narrow hybrid zone west of Alexandria. The lack of differences in the genitalia and the lack of reciprocal monophyly of the mitochondrial haplotypes of E. d. desertorum and E. desertorum irregularis support their classification as subspecies rather than distinct species. Low genetic distances indicate that the differentiation is probably less than half a million years old. The genetic data indicate a population expansion in agreement with other evidence that the Nile region in northern Egypt was more humid well into historical times than today. Shell size and shape are correlated with a climatic gradient from cooler and more humid conditions along the Mediterranean coast to arid and hot conditions in the interior. The decrease of body size with decreasing precipitation and increasing temperature might be explained by limited time for food intake in the more arid regions. The shape differences between the taxa are partly an indirect consequence of selection for body size, but are also directly affected by selection for reduction of aperture size.