bluuebunny/crossref_metadata_2025_split huggingface dataset:
The changing global carbon cycle: linking plant–soil carbon dynamics to global consequences
Authors: Stuart Chapin III F. , McFarland Jack , David McGuire A. , Euskirchen Eugenie S. , Ruess Roger W. , Kielland Knut 
Published: August 2009

Summary 1.
Most current climate–carbon cycle models that include the terrestrial carbon (C) cycle are based on a model developed 40 years ago by Woodwell & Whittaker (1968) and omit advances in biogeochemical understanding since that time. Their model treats net C emissions from ecosystems as the balance between net primary production (NPP) and heterotrophic respiration (HR, i.e. primarily decomposition). 2.  Under conditions near steady state, geographic patterns of decomposition closely match those of NPP, and net C emissions are adequately described as a simple balance of NPP and HR (the Woodwell‐Whittaker model). This close coupling between NPP and HR occurs largely because of tight coupling between C and N (nitrogen) cycles and because NPP constrains the food available to heterotrophs. 3.
Processes in addition to NPP and HR become important to understanding net C emissions from ecosystems under conditions of rapid changes in climate, hydrology, atmospheric CO2, land cover, species composition and/or N deposition. Inclusion of these processes in climate–C cycle models would improve their capacity to simulate recent and future climatic change. 4.  Processes that appear critical to soil C dynamics but warrant further research before incorporation into ecosystem models include below‐ground C flux and its partitioning among roots, mycorrhizas and exudates; microbial community effects on C sequestration; and the effects of temperature and labile C on decomposition. The controls over and consequences of these processes are still unclear at the ecosystem scale. 5.  Carbon fluxes in addition to NPP and HR exert strong influences over the climate system under conditions of rapid change. These fluxes include methane release, wildfire, and lateral transfers of food and fibre among ecosystems. 6.  Water and energy exchanges are important complements to C cycle feedbacks to the climate system, particularly under non‐steady‐state conditions. An integrated understanding of multiple ecosystem–climate feedbacks provides a strong foundation for policies to mitigate climate change. 7.
Synthesis. Current climate systems models that include only NPP and HR are inadequate under conditions of rapid change. Many of the recent advances in biogeochemical understanding are sufficiently mature to substantially improve representation of ecosystem C dynamics in these models.
Vegetation composition promotes carbon and nitrogen storage in model grassland communities of contrasting soil fertility
Authors: De Deyn Gerlinde B. , Quirk Helen , Yi Zou , Oakley Simon , Ostle Nick J. , Bardgett Richard D. 
Published: August 2009

Summary 1. The benefits of plant functional group and plant species diversity for sustaining primary productivity have been extensively studied. However, few studies have simultaneously explored potential benefits of plant species and functional group richness and composition for the delivery of other ecosystem services and their dependency on resource availability. 2. Here, we investigated in soils of different fertility the effects of plant species and functional group richness and composition on carbon (C) and nitrogen (N) stocks in vegetation, soil and soil microbes and on CO2 exchange and the loss of C and N from soil through leaching. We established plant communities from a pool of six mesotrophic grassland species belonging to one of three functional groups (C3 grasses, forbs and legumes) in two soils of contrasting fertility. We varied species richness using one, two, three or six species and one, two or three functional groups. 3. After 2 years, vegetation C and N and soil microbial biomass were greater in the more fertile soil and increased significantly with greater numbers of plant species and functional group richness. The positive effect of plant diversity on vegetation C and N coincided with reduced loss of water and N through leaching, which was especially governed by forbs, and increased rates of net ecosystem CO2 exchange. 4. Soil C and N pools were not affected by the number of plant species or functional group richness per se after 2 years, but were enhanced by the presence and biomass of the legumes Lotus corniculatus and Trifolium repens. 5.
Synthesis. Collectively, our findings indicate that changes in plant species and functional group richness influence the storage and loss of both C and N in model grassland communities but that these responses are related to the presence and biomass of certain plant species, notably N fixers and forbs. Our results therefore suggest that the co‐occurrence of species from specific functional groups is crucial for the maintenance of multifunctionality with respect to C and N storage in grasslands.
An experimental comparison of chemical traits and litter decomposition rates in a diverse range of subarctic bryophyte, lichen and vascular plant species
Authors: Lang Simone I. , Cornelissen Johannes H. C. , Klahn Thorsten , Van Logtestijn Richard S. P. , Broekman Rob , Schweikert Wenka , Aerts Rien 
Published: August 2009

Summary1. Climate change in the subarctic is expected to influence vegetation composition, specifically bryophyte and lichen communities, thereby modifying litter decomposition rates and carbon (C) dynamics of these systems with possible feedbacks to climate.2. In a 2‐year experiment, we investigated decomposition rates and chemical traits of 27 bryophytes, 17 lichens and 5 vascular plants in litter beds in subarctic Sweden. The majority of the sampled cryptogam species are widespread at higher northern latitudes.3. Average 2‐year litter decomposition rates (exponential mass loss constantk) of lichen (0.44 ± 0.01) and vascular plant (0.56 ± 0.03) species were higher than that of bryophytes (0.11 ± 0.01), while within main cryptogam taxa, species identity was an important determinant of mass loss rates. At cryptogam group level, 2‐year litter mass loss ofSphagnumwas significantly lower than for non‐Sphagnummosses and liverworts. Within lichens, N2‐fixing versus non‐N2‐fixing lichens showed no variation in decomposability.4. In a subset of the large species set, mass loss differed both among incubation environments (reflecting nutrient‐rich and poor birch forest andSphagnumpeatlands, respectively) and species. The pattern of mass loss across incubation environments was not consistent among cryptogam species. N2‐fixing, in contrast to non‐N2‐fixing lichens with lower nitrogen (N) levels displayed similar decomposition rates across incubation environments. Mass loss of non‐Sphagnummosses was correlated with initial N irrespective of incubation environment.5. Litter mass loss of cryptogam taxa could be predicted very well from infrared spectra of the initial chemical composition of the species, by application of Fourier transform infrared using an attenuated total reflectance probe. The initial macronutrient concentrations (N, phosphorus, C and cations) and initial litter pH correlated less well.6. Synthesis. We showed comprehensively that decomposition rates of bryophytes are generally lower than those of lichens and vascular plants. Among bryophyte or lichen species there is also great variation in litter decomposability which depends strongly on species‐specific chemistry. Our data will help predict changing land surface feedback to C cycles and climate in cold biomes by understanding long‐term climate effects on litter decomposability through shifting vegetation composition.
Another way to divide: the case of anammox bacteria
Authors: Rachel Reinhard 
Published: August 2009

SummaryAnammox bacteria exhibit remarkable and characteristic metabolic features that enable them to oxidize ammonium under anoxic conditions. Their ultrastructure is complex, with three compartments, comprising paryphoplasm, the riboplasm and the anammoxosome. The latter is surrounded by ladderane lipids, creating a lipid‐surrounded organelle within the riboplasm. In this edition of Molecular Microbiology, van Niftrik and co‐workers present detailed ultrastructural investigations that, together with the analysis of the product of a predicted gene and its localization in ultrathin sections, provide the first hints at the way in which these cells divide.
A LuxRI‐family regulatory system controls excision and transfer of the Mesorhizobium loti strain R7A symbiosis island by activating expression of two conserved hypothetical genes
Authors: Ramsay Joshua P. , Sullivan John T. , Jambari Nuzul , Ortori Catharine A. , Heeb Stephan , Williams Paul , Barrett David A. , Lamont Iain L. , Ronson Clive W. 
Published: August 2009

SummaryThe symbiosis island ICEMlSymR7A of Mesorhizobium loti R7A is an integrative and conjugative element (ICE) that carries genes required for a nitrogen‐fixing symbiosis with Lotus species. ICEMlSymR7A encodes homologues (TraR, TraI1 and TraI2) of proteins that regulate plasmid transfer by quorum sensing in rhizobia and agrobacteria. Introduction of traR cloned on a plasmid induced excision of ICEMlSymR7A in all cells, a 1000‐fold increase in the production of 3‐oxo‐C6‐homoserine lactone (3‐oxo‐C6‐HSL) and a 40‐fold increase in conjugative transfer. These effects were dependent on traI1 but not traI2. Induction of expression from the traI1 and traI2 promoters required the presence of plasmid‐borne traR and either traI1 or 100 pM 3‐oxo‐C6‐HSL, suggesting that traR expression or TraR activity is repressed in wild‐type cells by a mechanism that can be overcome by additional copies of traR. The traI2 gene formed an operon with hypothetical genes msi172 and msi171 that were essential for ICEMlSymR7A excision and transfer. Our data suggest that derepressed TraR in conjunction with TraI1‐synthesized 3‐oxo‐C6‐HSL regulates excision and transfer of ICEMlSymR7A through expression of msi172 and msi171. Homologues of msi172 and msi171 were present on putative ICEs in several α‐proteobacteria, indicating a conserved role in ICE excision and transfer.
Plasmodium falciparum circumsporozoite protein: epidemiological variations among field isolates prevalent in India
Authors: Singh J. P. N. , Verma S. , Bhattacharya P. R. , Srivastava N. , Dash A. P. , Biswas S. 
Published: August 2009

SummaryObjective  To investigate the extent of genetic variations in T‐helper‐cell epitopic regions of circumsporozoite (CS) protein in Plasmodium falciparum field isolates collected from different regions of India at different phases of malaria transmission.Methods  Genomic DNA was isolated from 507 P. falciparum wild‐parasite isolates obtained from six geographical locations of India at three time points coinciding with malaria transmissions. The T‐helper‐cell epitopic regions were polymerase chain reaction (PCR)‐amplified and the products were purified and then sequenced.Results  Based on sequences, nine variants were found among isolates and they were categorized into nine groups (V‐1 to V‐9), where V‐1 and V‐2 were observed in all three time points (TP). The variants V‐1 to V‐4 in TP‐1; V‐1, V‐2, V‐5 to V‐8 in TP‐2; and V‐1, V‐2, V‐5 and V‐9 in TP‐3 were present and they showed restricted heterogeneity. During peak transmission (TP‐2), parasite populations were more diverse and heterogeneous and the variants regionally unbiased and restricted. However, the alleles of V‐6 and V‐9 in both Th2R and Th3R showed identical sequence variation with those observed in other geographical regions of the world. The remaining seven groups did not show such similarity.Conclusion  The Th2R and Th3R epitopes are implicated in host immune response to P. falciparum. The polymorphism in these epitopic regions indicates antigenic diversity, which may cause adverse outcome of a subunit vaccine including the CS prototype variant. Therefore, the formulation of a vaccine considering the restricted local repertoire parasite populations may be helpful.
Differential Evolution of Advertisement Call Traits in Dart‐Poison Frogs (Anura: Dendrobatidae)
Authors: Erdtmann Luciana , Amézquita Adolfo 
Published: August 2009

AbstractThe ability to recognise and discriminate between heterospecific and conspecific individuals plays an essential role in mate choice, reproductive isolation and thus species diversification. Many animals discriminate based on advertisement calls, whose evolution may be driven by a variety of forces such as natural selection, sexual selection or stochastic processes. The relative importance of stochastic processes acting on a given trait is usually correlated with its phylogenetic signal. Mate‐recognition signals are complex traits composed of multiple features that could potentially respond independently to evolutionary forces. The advertisement call of anurans is used in species recognition and mate choice. In this study, we estimate the phylogenetic signal for body size and a suite of traits describing the male advertisement call from dart‐poison frogs (Anura: Dendrobatidae). We found a surprisingly high phylogenetic signal for all call traits. In addition, call traits varied in their degree of phylogenetic signal, suggesting that evolutionary forces have been acting differently on different traits. Pulse duration showed the strongest phylogenetic signal. Peak frequency and body size were correlated and presented high phylogenetic signal indicating that the evolution of one trait may be driving or constraining the other. Since most variation in call traits can be explained by the phylogenetic history of the species, we cannot reject the hypothesis that stochastic processes account for significant evolutionary divergence in frog calls.
Influence of Winter Ranging Behaviour on the Social Organization of a Cooperatively Breeding Bird Species, The Apostlebird
Authors: Griesser Michael , Barnaby Jonathan , Schneider Nicole A. , Figenschau Nina , Wright Jonathan , Griffith Simon C. , Kazem Anahita , Russell Andrew F. 
Published: August 2009

AbstractMost cooperative breeding bird species live in family groups that are formed through the prolonged association of offspring with their parents. Research into cooperative families has in particular investigated the balance between cooperation and conflict over reproductive decisions. As a consequence of this research focus, social interactions among group members outside the breeding season are rarely studied, despite the fact that they are likely to be crucial for social decisions. We investigated the social dynamics and ranging behaviour of the family group living cooperatively breeding apostlebird (Struthidea cinerea) outside the breeding season. Group size changed between, but not within, the seasons, being smaller during the breeding season than in the winter season. This change in group size was a consequence of breeding groups merging after breeding, then splitting again before the next breeding season. While breeding groups used small, non‐overlapping home ranges ( = 113 ha) around the nesting site, during winter groups moved up to 1200 ha ( = 598 ha), and interacted frequently with up to four other winter groups. In particular large groups often joined together during winter and spent up to 50% of their time associating with other large winter groups. This apparent fission‐fusion system facilitated the exchange of group members, offering the possibility to form new breeding coalitions and new groups. The results of this study suggest that behaviour outside the breeding season can be of considerable importance to the social dynamics of both families and cooperative breeding in such systems.
Fixed Rejection Responses to Single and Multiple Experimental Parasitism in TwoFringillaHosts of the Common Cuckoo
Authors: Vikan Johan R. , Stokke Bård G. , Fossøy Frode , Jackson Craig , Huhta Esa , Rutila Jarkko , Moksnes Arne , Røskaft Eivin 
Published: August 2009

AbstractPrevious studies have shown that the tendency to reject parasitic eggs among certain hosts is strongly dependent on the degree of similarity with own eggs, whereas other conditional cues do not affect rejection decisions. This paper examines whether two such hosts, the closely related brambling and chaffinch, show a different tendency to reject parasitic eggs if they are multiply parasitized. Some individuals were experimentally parasitized with both a non‐mimetic and a low–intermediate contrasting egg in the same breeding attempt. The non‐mimetic egg was rejected almost without exception. In chaffinches, the low–intermediate contrasting egg was introduced shortly after rejection of the non‐mimetic egg whereas in bramblings, both eggs were introduced simultaneously. A control group consisted of individuals that were parasitized with one low–intermediate contrasting egg. There was no significant difference in the tendency to reject the low–medium contrasting eggs between the experimental and control group in any of the species, implying that the same acceptance threshold is applied to each parasitic egg independently. Moreover, the rejection rate of non‐mimetic eggs was high (>90%) regardless of whether the egg was introduced alone or together with a low–medium contrasting egg. The results are discussed in relation to recent studies with great reed warblersAcrocephalus arundinaceusthat obtained contrasting results in similar experimental designs. The different degrees of flexibility displayed byFringillaand great reed warbler hosts are likely to reflect differences in both the perception and action component of the recognition system.
Prevalence of i.v. thiopental use in psychiatric emergency settings in Japan
Authors: Hatta Kotaro , Nakamura Mitsuru , Yoshida Kenichi , Hamakawa Hiroshi , Wakejima Toru , Nishimura Takao , Kawabata Toshitaka , Hirata Toyoaki , Usui Chie , Sawa Yutaka 
Published: August 2009

Aim:  Because i.v. barbiturates such as thiopental carry the risk of apnea and laryngeal spasm in asthmatic patients, reducing the use of barbiturate in emergency situations is important. The purpose of the present study was therefore to investigate the prevalence of i.v. thiopental as a choice of sedation in behavioral emergency settings, we conducted a cross‐sectional multicenter study.Methods:  Psychiatric emergency departments of seven hospitals were studied during a 4‐month period. Patients with a score >15 on the Excited Component of the Positive and Negative Syndrome Scale (PANSS‐EC) who received i.v. medication were included in the study. Drugs were chosen according to the Japanese guidelines, in which the first injection was either haloperidol or benzodiazepine in accordance with clinical requirements. A second injection, which was the opposite drug to the first injection was administered as needed. Only when excitement obviously increased following the first injection, which was considered uncontrollable without thiopental according to expert experience, was thiopental given as a second injection. A total of 137 patients were included. The mean age was 40.4 years (SD 13.1), and the rate of male gender, drug‐naïve, and F2 (schizophrenia, schizotypal and delusional disorders) on the ICD‐10 were 48.9%, 29.9%, and 65.7%, respectively.Results:  The rate of patients treated with thiopental as a second injection was 8.0% (n = 11). All of the first injections in patients treated with thiopental were not haloperidol but benzodiazepines (P = 0.0072).Conclusion:  Because this multicenter study has an epidemiological character, the prevalence of i.v. thiopental use in psychiatric emergency settings in Japan is considered to be 8.0%.
Effect of age and gender on schizotypal personality traits in the normal population
Authors: Bora Emre , Baysan Arabaci Leyla 
Published: August 2009

Aim:  There is some evidence that age and gender influence expression of schizotypal traits in the normal population. One important limitation of previous studies, however, is the restricted age range of subjects. The aim of the present study was therefore to investigate the effect of gender and age on schizotypal personality features.Methods:  A total of 1024 participants aged between 16 and 90 were assessed using the schizotypal personality questionnaire. The effect of gender and age on schizotypal features was investigated. Confirmatory factor analysis was used to examine the factor structure of the scale in different age groups.Results:  Male subjects scored higher than women in negative and disorganized‐like symptoms. Female subjects scored significantly in social anxiety and odd belief subscales. Younger participants significantlyscored higher in reference, odd belief, unusual perceptual experiences, odd behavior and odd speech subscales. While decreases in schizotypy scores were gradual for most of the scales, increased disorganization in female subjects was restricted to late adolescence. Confirmatory factor analysis of the data supported modified versions of the Raine three‐factor model across all age groups.Conclusion:  Psychological changes related to adolescence and better social adaptation as a result of life experience might contribute to the age‐ and gender‐related differences in schizotypy.
Do inefficient selfing and inbreeding depression challenge the persistence of the rare Dianthus guliae Janka (Caryophyllaceae)? Influence of reproductive traits on a plant's proneness to extinction
Authors: GARGANO DOMENICO , GULLO TERESA , BERNARDO LILIANA 
Published: August 2009

AbstractThe yellow carnation Dianthus guliae Janka is a rare endemic of the Italian peninsula. As numerous extinctions have occurred in the past, very few populations are still present. Two years of field surveys revealed high mortality and an absence of recruitment in the southernmost populations of this species. Work in a botanical garden, under semi‐natural conditions, revealed the occurrence of proterandrous hermaphroditism and self‐compatibility. The durable flower lifespan, the competitive effects among flowers and the different outcomes from spontaneous and hand‐performed pollinations (with both self‐ and cross‐pollen) suggested low pollination rates in the experimental stand. Pollinator exclusion experiments revealed a low frequency of delayed autonomous selfing, suggesting that self‐fertilization in D. guliae relies mainly on facilitated selfing and geitonogamy. Studies of inbreeding depression during the early life‐history stages revealed significant differences between selfed and crossed progenies in terms of seed mass, germination rates, developmental vigour and mortality rates. Therefore, when pollen delivery is scarce, the plant may fail reproductive assurance via autonomous selfing. The influence of inbreeding depression contributes to a further reduction in recruitment chances in very small D. guliae populations. Experimental reintroductions are urgent to avoid local extinction at the southern periphery of its range.