bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shrub expansion in tundra ecosystems: dynamics, impacts and research priorities
Authors: Myers-Smith Isla H , Forbes Bruce C , Wilmking Martin , Hallinger Martin , Lantz Trevor , Blok Daan , Tape Ken D , Macias-Fauria Marc , Sass-Klaassen Ute , Lévesque Esther , Boudreau Stéphane , Ropars Pascale , Hermanutz Luise , Trant Andrew , Collier Laura Siegwart , Weijers Stef , Rozema Jelte , Rayback Shelly A , Schmidt Niels Martin , Schaepman-Strub Gabriela , Wipf Sonja , Rixen Christian , Ménard Cécile B , Venn Susanna , Goetz Scott , Andreu-Hayles Laia , Elmendorf Sarah , Ravolainen Virve , Welker Jeffrey , Grogan Paul , Epstein Howard E , Hik David S 
Published: December 2011

Abstract
Recent research using repeat photography, long-term ecological monitoring and dendrochronology has documented shrub expansion in arctic, high-latitude and alpine tundra ecosystems. Here, we (1) synthesize these findings, (2) present a conceptual framework that identifies mechanisms and constraints on shrub increase, (3) explore causes, feedbacks and implications of the increased shrub cover in tundra ecosystems, and (4) address potential lines of investigation for future research. Satellite observations from around the circumpolar Arctic, showing increased productivity, measured as changes in ‘greenness’, have coincided with a general rise in high-latitude air temperatures and have been partly attributed to increases in shrub cover. Studies indicate that warming temperatures, changes in snow cover, altered disturbance regimes as a result of permafrost thaw, tundra fires, and anthropogenic activities or changes in herbivory intensity are all contributing to observed changes in shrub abundance. A large-scale increase in shrub cover will change the structure of tundra ecosystems and alter energy fluxes, regional climate, soil–atmosphere exchange of water, carbon and nutrients, and ecological interactions between species. In order to project future rates of shrub expansion and understand the feedbacks to ecosystem and climate processes, future research should investigate the species or trait-specific responses of shrubs to climate change including: (1) the temperature sensitivity of shrub growth, (2) factors controlling the recruitment of new individuals, and (3) the relative influence of the positive and negative feedbacks involved in shrub expansion.
Using an individual-based model with four trophic levels to model the effect of predation and competition on squid recruitment
Authors: Sinerchia Matteo , Field Anthony J. , Woods John D. , Vallerga Silvana , Hinsley Wes R. 
Published: December 2011

Abstract
Sinerchia, M., Field, A. J., Woods, J. D., Vallerga, S., and Hinsley, W. R. 2012. Using an individual-based model with four trophic levels to model the effect of predation and competition on squid recruitment. – ICES Journal of Marine Science, 69: 439–447. The Lagrangian Ensemble recruitment model (LERM) is the first prognostic model of fisheries recruitment based upon individuals. It incorporates five functional groups: phytoplankton (diatoms), herbivorous zooplankton (copepods), carnivorous zooplankton (squid paralarvae), and two top predators. Physiology and behaviour are described by equations derived from literature based on reproducible laboratory experiments. LERM is built using the Lagrangian Ensemble metamodel, in which the demography and biofeedback of each dynamic population are diagnostic properties, emerging from the life histories of individuals. The response of the plankton ecosystem and squid recruitment to different scenarios of exogenous forcing is investigated. Simulations were run at 41°N 27°W (Azores) under a stationary annual cycle of atmospheric forcing. The ecosystem adjusts to a stable attractor for each scenario. The emergent properties of each attractor are investigated, with focus on predation, competition for food, and spawning magnitude. Annual recruitment is a complex emergent property dependent on several factors, including food availability, predation, competition, and post-hatching growth rate, as proposed by Hjort's critical period theory, relating recruitment to predation mortality, depending on growth rate and hence food availability. The model provides a useful step towards linking small-scale processes governing the life histories of larvae and fisheries on the large scale.
Concurrent recruitment failure in gadoids and changes in the plankton community along the Norwegian Skagerrak coast after 2002
Authors: Johannessen Tore , Dahl Einar , Falkenhaug Tone , Naustvoll Lars J. 
Published: December 2011

Abstract
Johannessen, T., Dahl, E., Falkenhaug, T., and Naustvoll, L. J. 2012. Concurrent recruitment failure in gadoids and changes in the plankton community of the Norwegian Skagerrak coast after 2002. – ICES Journal of Marine Science, 69: 795–801. Since 1919, annual beach-seine sampling has been carried out along the Norwegian Skagerrak coast with the main objective of measuring the abundance of 0-group gadoids. Repeated incidents of abrupt and persistent recruitment collapses in gadoid populations have been observed locally. These collapses have been linked to gradual eutrophication, which has resulted in abrupt changes in the plankton community and deprivation of adequate prey for 0-group fish. Since 2002, the recruitment of 0-group gadoids has been very poor along the Skagerrak coast on a regional scale. At the same time, major changes in the plankton community have been observed. A regular and pronounced autumn bloom dominated by red-tide forming dinoflagellates such as large Ceratium spp. and the toxic Karenia mikimotoi has practically vanished, and a linear decrease in oxygen concentration at intermediate depths (30 m) that has been evident since the 1960s, was reversed around 2002. These changes would normally indicate improved environmental conditions. However, the recruitment failure in gadoids does not support this perception. Rather, the evidence points towards a potential shift in the plankton community that has resulted in gadoid recruitment failure.
An Abscisic Acid-AtNAP Transcription Factor-SAG113 Protein Phosphatase 2C Regulatory Chain for Controlling Dehydration in Senescing Arabidopsis Leaves
Authors: Zhang Kewei , Gan Su-Sheng 
Published: December 2011

Abstract
AtNAP is a NAC family transcription factor gene that plays a key role in leaf senescence but its underlying mechanisms are not known. SENESCENCE-ASSOCIATED GENE113 (SAG113), a gene encoding a Golgi-localized protein phosphatase 2C family protein phosphatase, mediates abscisic acid (ABA)-regulated stomatal movement and water loss specifically during leaf senescence. Here we report that SAG113 is a direct target gene of the AtNAP transcription factor. We found that both AtNAP and SAG113 were induced by leaf senescence and ABA. When AtNAP was chemically induced, SAG113 was also induced whereas when AtNAP was knocked out, the ABA- and senescence-induced expression of SAG113 was reduced. These data suggest that the expression of SAG113 is predominantly dependent on AtNAP. Functionally, overexpression of SAG113 restored the markedly delayed leaf senescence phenotype in atnap knockouts to wild type. Yeast (Saccharomyces cerevisiae) one-hybrid experiments and electrophoresis mobility shift assays showed that AtNAP could physically bind to the SAG113 promoter in vivo and in vitro, respectively. Site-directed mutagenesis revealed that AtNAP binds to a 9-bp core sequence of the SAG113 promoter, 5′CACGTAAGT3′. These results indicate that there is a unique regulatory chain, ABA-AtNAP-SAG113 protein phosphastase 2C, which controls stomatal movement and water loss during leaf senescence.
Co-Overexpression FIT with AtbHLH38 or AtbHLH39 in Arabidopsis-Enhanced Cadmium Tolerance via Increased Cadmium Sequestration in Roots and Improved Iron Homeostasis of Shoots
Authors: Wu Huilan , Chen Chunlin , Du Juan , Liu Hongfei , Cui Yan , Zhang Yue , He Yujing , Wang Yiqing , Chu Chengcai , Feng Zongyun , Li Junming , Ling Hong-Qing 
Published: December 2011

Abstract
Cadmium (Cd) is toxic to plant cells. Under Cd exposure, the plant displayed leaf chlorosis, which is a typical symptom of iron (Fe) deficiency. Interactions of Cd with Fe have been reported. However, the molecular mechanisms of Cd-Fe interactions are not well understood. Here, we showed that FER-like Deficiency Induced Transcripition Factor (FIT), AtbHLH38, and AtbHLH39, three basic helix-loop-helix transcription factors involved in Fe homeostasis in plants, also play important roles in Cd tolerance. The gene expression analysis showed that the expression of FIT, AtbHLH38, and AtbHLH39 was up-regulated in the roots of plants treated with Cd. The plants overexpressing AtbHLH39 and double-overexpressing FIT/AtbHLH38 and FIT/AtbHLH39 exhibited more tolerance to Cd exposure than wild type, whereas no Cd tolerance was observed in plants overexpressing either AtbHLH38 or FIT. Further analysis revealed that co-overexpression of FIT with AtbHLH38 or AtbHLH39 constitutively activated the expression of Heavy Metal Associated3 (HMA3), Metal Tolerance Protein3 (MTP3), Iron Regulated Transporter2 (IRT2), and Iron Regulated Gene2 (IREG2), which are involved in the heavy metal detoxification in Arabidopsis (Arabidopis thaliana). Moreover, co-overexpression of FIT with AtbHLH38 or AtbHLH39 also enhanced the expression of NICOTIANAMINE SYNTHETASE1 (NAS1) and NAS2, resulting in the accumulation of nicotiananamine, a crucial chelator for Fe transportation and homeostasis. Finally, we showed that maintaining high Fe content in shoots under Cd exposure could alleviate the Cd toxicity. Our results provide new insight to understand the molecular mechanisms of Cd tolerance in plants.
Polyphasic approach and typification of selected Phormidium strains (Cyanobacteria)
Authors: Sciuto Katia , Andreoli Carlo , Rascio Nicoletta , La Rocca Nicoletta , Moro Isabella 
Published: December 2011

AbstractCyanobacteria (phylum Cyanophyta/Cyanobacteria, class Cyanophyceae) are among the most widespread organisms and are able to adapt themselves to different extreme environments. These micro‐organisms have an important ecological role, given their ability to perform oxygenic photosynthesis, and are employed in different fields based on their ability to produce several bioactive compounds. Their prokaryotic nature, the presence of many cryptic species, and the coexistence of different nomenclature systems make the taxonomic identification of cyanobacteria particularly difficult. Moreover, for several species, the original reference strains (holotypes) are lacking. Increasingly, authors are using a polyphasic approach to characterize cyanobacteria, while typification is a recent trend that is being used to solve the problem of missing holotypes in other micro‐organisms. Here we focus on a filamentous cyanobacterium, isolated from the Euganean Thermal District (Padova, Italy) and temporarily named strain ETS‐02, using a polyphasic approach that includes morphological, ultrastructural, biochemical (pigment and fatty acid content), physiological (nitrogen fixation), and genetic (16S rRNA, 16S–23S ITS, cpcB‐IGS‐cpcA, rpoC1, gyrB, rbcL, nifD loci) analyses. The description of Phormidium cf. irriguum CCALA 759 as the epitype of Phormidium irriguum was also used to complete the characterization of strain ETS‐02.
In-vivoextravasation induces the expression of interleukin 1 receptor type 1 in human neutrophils
Authors: Paulsson J M , Moshfegh A , Dadfar E , Held C , Jacobson S H , Lundahl J 
Published: December 2011

SummaryIn order to address neutrophil activation during inflammation we assessed the expression of interleukin 1 receptor type 1 (IL-1R1) following in-vivo extravasation. Extravasated neutrophils were collected from 11 healthy study subjects by a skin chamber technique and compared to neutrophils in peripheral blood. Expression of IL-1R1 was assessed by microarray, quantitative polymerase chain reaction (qPCR), Western blot, flow cytometry, enzyme linked immunosorbent assay (ELISA) and immunoelectron microscopy (iEM). IL-1R1 was induced following extravasation, demonstrated by both gene array and qPCR. Western blot demonstrated an increased expression of IL-1R1 in extravasated leucocytes. This was confirmed further in neutrophils by flow cytometry and iEM that also demonstrated an increased intracellular pool of IL-1R1 that could be mobilized by N-formyl-methionine-leucine-phenylalanine (fMLP). Stimulation of peripheral neutrophils with IL-1 resulted in transcription of NFκB and a number of downstream chemokines and the corresponding chemokines were also induced following in-vivo extravasation. The present results demonstrate that IL-1R1 is induced following extravasation and exists on the neutrophil surface, as well as in a mobile intracellular pool. Furthermore, neutrophils express functional IL-1R1 as demonstrated by the induction of chemokines following IL-1 stimulation. The results indicate a potential role for IL-1 in the activation of neutrophils at inflammatory sites.
Increased levels and adipose tissue expression of visfatin in morbidly obese women: the relationship with pro‐inflammatory cytokines
Authors: Terra Ximena , Auguet Teresa , Quesada Isabel , Aguilar Carmen , Luna Anna Maria , Hernández Mercé , Sabench Fátima , Porras José Antonio , Martínez Salomé , Lucas Anna , Pellitero Silvia , Llutart Jordi , del Castillo Daniel , Richart Cristóbal 
Published: December 2011

SummaryObjective  The controversial results on the physiopathological role of visfatin led us to examine both circulating visfatin levels and gene expression in visceral (VAT) and subcutaneous fat (SAT) in a homogeneous group of morbidly obese women.Design, patients and measurements  We analysed circulating levels of several adipo/cytokines in 133 Spanish women: 40 lean (C) [body mass index (BMI) < 25 kg/m2] and 93 morbidly obese (MO) (BMI > 40 kg/m2). In the MO group, we found 31 diabetic and 62 nondiabetic subjects. We obtained follow‐up blood samples at 6 and 12 months after bariatric surgery from 30 MO patients. We determined the circulating levels of visfatin, adiponectin, interleukin‐6 (IL6), C‐reactive protein (CRP), resistin and tumour necrosis factor‐α (TNFα) by ELISA, and visfatin, adiponectin, IL6, resistin and TNFα gene expression in SAT and VAT by real‐time RT‐PCR.Results  Circulating visfatin levels were higher in MO women compared with lean controls (C = 1·43 ± 0·14 μg/l, MO = 3·60 ± 0·29 μg/l, P < 0·001). After bariatric surgery‐induced weight loss, visfatin levels were reduced significantly over 12 months. Visfatin expression in SAT and VAT was similar, but significantly higher in MO compared to C and independent of the presence of diabetes mellitus. Circulating visfatin levels were positively related to IL6 and CRP levels. Visfatin gene expression in VAT and SAT was strongly related to IL6 and TNFα expression.Conclusion  In a homogeneous cohort of morbidly obese women, our findings show that visfatin has a strong relationship with pro‐inflammatory factors in severe obesity.
Update of the precision geoid determination in Korea
Authors: Bae Tae‐Suk , Lee Jisun , Kwon Jay Hyoun , Hong Chang‐Ki 
Published: December 2011

ABSTRACTFrom the late 1990s, many studies on local geoid construction have been made in South Korea. However, the precision of the previous geoid has remained about 15 cm due to distribution and quality problems of gravity and GPS/levelling data. Since 2007, new land gravity data and GPS/levelling data have been obtained through many projects such as the Korean Land Spatilaization, Unified Control Point and Gravity survey on the Benchmark. The newly obtained data are regularly distributed to a certain degree and show much better improvement in their quality. In addition, an airborne gravity survey was conducted in 2008 to cover the Korean peninsula (South Korea only). Therefore, it is expected that the precision of the geoid could be improved. In this study, the new South Korean gravimetric geoid and hybrid geoid are presented based on land, airborne, ship‐borne, altimeter gravity data, geopotential model and topographic data. As for the methodology, the general remove‐restore approach was applied with the best chosen parameters in order to produce a precise local geoid. The global geopotential model EGM08 was used to remove the low‐frequency components using degree and order up to 360 and the short wavelength part of the gravity signal was dealt with by using the Shuttle Radar Topography Mission data. The parameters determined empirically in this study include for Stokes’ integral 0.5° and for Wong‐Gore kernel 110–120°, respectively and 10 km for both the Bjerhammar sphere depth and attenuation factor. The final gravimetric geoid in South Korea ranges from 20–31 m with a precision of 5.45 cm overall compared to 1096 GPS/levelling data. In addition, the South Korean hybrid geoid produces 3.46 cm and 3.92 cm for degrees of fitness and precision, respectively and a better statistic of 2.37 cm for plain and urban areas was achieved. The gravimetric and hybrid geoids are expected to improve further when the refined land gravity data are included in the near future.
Two‐dimensional controlled‐source electromagnetic interferometry by multidimensional deconvolution: spatial sampling aspects
Authors: Hunziker Jürg , Slob Evert , Fan Yuanzhong , Snieder Roel , Wapenaar Kees 
Published: December 2011

ABSTRACTWe use numerically modelled data sets to investigate the sensitivity of electromagnetic interferometry by multidimensional deconvolution to spatial receiver sampling. Interferometry by multidimensional deconvolution retrieves the reflection response below the receivers after decomposition of the fields into upward and downward decaying fields and deconvolving the upward decaying field by the downward decaying field. Thereby the medium above the receiver level is replaced with a homogeneous half‐space, the sources are redatumed to the receiver level and the direct field is removed. Consequently, in a marine setting the retrieved reflection response is independent of any effect of the water layer and the air above. A drawback of interferometry by multidimensional deconvolution is a possibly unstable matrix inversion, which is necessary to retrieve the reflection response. Additionally, in order to correctly separate the upward and the downward decaying fields, the electromagnetic fields need to be sampled properly. We show that the largest possible receiver spacing depends on two parameters: the vertical distance between the source and the receivers and the length of the source. The receiver spacing should not exceed the larger of these two parameters. Besides these two parameters, the presence of inhomogeneities close to the receivers may also require a dense receiver sampling. We show that by using the synthetic aperture concept, an elongated source can be created from conventionally acquired data in order to overcome these strict sampling criteria. Finally, we show that interferometry may work under real‐world conditions with random noise and receiver orientation and positioning errors.
Elastic properties of seafloor sediments from the modelling of amplitudes of multiple water waves recorded on the seafloor off Bear Island, North Atlantic
Authors: Grad Marek , Mjelde Rolf , Czuba Wojciech , Guterch Aleksander ,   the IPY Project Group
Published: December 2011

ABSTRACTWide‐angle seismic data acquired by use of air‐guns and ocean bottom seismometers (OBS) contain strong direct water arrivals and multiples, generally considered as noise and thus not included in the modelling. However, a recent study showed that standard ray‐tracing modelling of the water multiples recorded off the Bear Island, North Atlantic, provided a reliable estimate of the velocity distribution in the water layer. Here, we demonstrate that including the amplitudes in the modelling provide valuable information about the VP contrast at the seafloor, as well as the VP/VS ratio and attenuation (QP) of the uppermost sediments. The VP contrast at the seafloor is estimated at about 250 m/s, within a precision of approximately ±30 m/s. The VP/VS ratio in the uppermost sedimentary layer is modelled in the range 2.25–2.50 and the QP factor is estimated at 1000 for the water, 30–50 for the uppermost layer and 40–50 for the second sedimentary layer. The values obtained for the sediments suggest a lithology dominated by silty clays, with porosity below average.
Limitations to sustainable frankincense production: blocked regeneration, high adult mortality and declining populations
Authors: Groenendijk Peter , Eshete Abeje , Sterck Frank J. , Zuidema Pieter A. , Bongers Frans 
Published: December 2011

Summary1. Resins are highly valued non‐timber forest products (NTFP). One of the most widely traded resins is frankincense, tapped from several Boswellia tree species (Burseraceae). Exploited Boswellia populations often show poor regeneration, but the demographic consequences of these bottlenecks are unknown. Here we report on the first large‐scale demographic study of frankincense‐producing trees.2. We studied 12 populations of Boswellia papyrifera in northern Ethiopia, varying in altitude and productivity. Six of these populations had been tapped before and were tapped during the study. Survival, growth and fecundity were determined for 4370 trees and 2228 seedlings, in 22.8 ha over a 2‐year period. We also studied a remote population where no grazing and tapping took place. Matrix models were used to project population growth and frankincense production under four restoration scenarios.3. Population structures of both tapped and untapped populations showed clear gaps. Small seedlings were abundant in all populations, but none developed into persistent saplings. Such saplings were only present in the remote population. Fire and grazing are the likely causes of this regeneration bottleneck.4. Adult mortality was high (6–7% per year) in both tapped and untapped populations, probably caused by beetle attacks and fire. Unexpectedly, tapped populations presented higher diameter growth rates and fecundity compared to untapped populations. These differences are probably caused by non‐random selection of exploited populations by tappers.5. Under the ‘business as usual’ scenario, population models projected a 90% decline in the size of tapped and untapped populations within 50 years and a 50% decline in frankincense yield within 15 years. Model simulations for restoration scenarios revealed that populations and frankincense production could only be sustained with intensive management leading to full sapling recruitment and a 50–75% reduction in adult mortality.6.
Synthesis and applications. Regeneration bottlenecks and high adult mortality are causing rapid decline in frankincense‐producing tree populations in Ethiopia. This decline is unlikely to be a consequence of harvesting and is probably driven by fire, grazing and beetle attacks. Fire prevention and the establishment of non‐grazing areas are needed. Our results show that other factors than exploitation may seriously threaten populations yielding NTFP.