bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subcellular Flux Analysis of Central Metabolism in a Heterotrophic Arabidopsis Cell Suspension Using Steady-State Stable Isotope Labeling
Authors: Masakapalli Shyam K. , Le Lay Pascaline , Huddleston Joanna E. , Pollock Naomi L. , Kruger Nicholas J. , Ratcliffe R. George 
Published: November 2009

Abstract
The presence of cytosolic and plastidic pathways of carbohydrate oxidation is a characteristic feature of plant cell metabolism. Ideally, steady-state metabolic flux analysis, an emerging tool for creating flux maps of heterotrophic plant metabolism, would capture this feature of the metabolic phenotype, but the extent to which this can be achieved is uncertain. To address this question, fluxes through the pathways of central metabolism in a heterotrophic Arabidopsis (Arabidopsis thaliana) cell suspension culture were deduced from the redistribution of label in steady-state 13C-labeling experiments using [1-13C]-, [2-13C]-, and [U-13C6]glucose. Focusing on the pentose phosphate pathway (PPP), multiple data sets were fitted simultaneously to models in which the subcellular compartmentation of the PPP was altered. The observed redistribution of the label could be explained by any one of three models of the subcellular compartmentation of the oxidative PPP, but other biochemical evidence favored the model in which the oxidative steps of the PPP were duplicated in the cytosol and plastids, with flux through these reactions occurring largely in the cytosol. The analysis emphasizes the inherent difficulty of analyzing the PPP without predefining the extent of its compartmentation and the importance of obtaining high-quality data that report directly on specific subcellular processes. The Arabidopsis flux map also shows that the potential ATP yield of respiration in heterotrophic plant cells can greatly exceed the direct metabolic requirements for biosynthesis, highlighting the need for caution when predicting flux through metabolic networks using assumptions based on the energetics of resource utilization.
Revealing secondary seed removers: results from camera trapping
Authors: Seufert Verena , Linden (née Heikamp) Birthe , Fischer Frauke 
Published: November 2009

AbstractThis paper reports the results of the first study on secondary seed removal of seeds dispersed by Sykes’ monkeys (Cercopithecus albogularis) using camera traps in Africa. Patterns of primary seed dispersal are often superimposed by secondary conveyance, emphasising the need to study these secondary processes carefully. As the agents and mechanisms of seed dispersal are often concealed, being carried out by cryptic or nocturnal animals in dense vegetation, camera trapping was deemed a viable means to investigate secondary removal of seeds disseminated by C. albogularis in the Western Soutpansberg, South Africa. Camera traps were established at preferred feeding trees of the focal Sykes’ monkey group to identify animal species that remove seeds and fruits spat and dropped to the forest floor and seed removal observations were carried out. This method proved to be effective in identifying seed removers and also allowed to get indications about the quantities of seeds removed. Ten animal species were recorded visiting the trees, of which eight were observed removing seeds and fruits. Overall seed and fruit removal rates were high, indicating that the foraging behaviour of C. albogularis attracts many terrestrial frugivores.
Aspects of community ecology of amphibians and reptiles at Bonny Island (Nigeria), an area of priority relevance for petrochemical industry
Authors: Akani Godfrey C. , Luiselli Luca M. 
Published: November 2009

AbstractFinima Nature Park, situated in Bonny Island (Niger Delta, Nigeria), is a protected forested area placed within one of the most industrially developed (and environmentally polluted) regions of the whole African continent. Amphibian and reptile community composition in relation to season and microhabitat characteristics was studied, by a combination of field techniques, during the wet and dry seasons of 2007 and 2008. Overall, a total of 21 species of reptiles from nine families (with 668 individuals caught) and eight amphibian species from five families (492 individuals caught) were recorded. Nearly 94% of the amphibian individuals and most of the species were recorded, especially during the wet season, whereas most of the reptiles were found with no inter‐seasonal differences. However,Agama agamaandMabuya affiniswere found especially during the dry season. As for microhabitat use, the reptile species showed a clear, aggregated preference for two microhabitat types (dry leaves and under logs), which are probably crucial when these animals need to lose body temperature to avoid overheating. Concerning amphibians, the various species used the available microhabitats in a way expectable from their main ecological traits, with toads differing from aquatic frogs, and these differing from arboreal frogs.
The role of lipopolysaccharide in the development of atopy in humans
Authors: Simpson A. , Martinez F. D. 
Published: November 2009

SummaryAtopy is a highly prevalent condition and remains the single biggest risk factor for asthma. Although atopy has a heritable component, the time frame of the increase in the prevalence indicates that it is not due to genetic factors alone. The relationship between allergen exposure and sensitization is complex. Lipopolysaccharide (LPS) and its bioactive moiety endotoxin are common to all gram‐negative bacteria, and have been used as a surrogate of microbial load. Endotoxin can be readily measured in dust collected from homes. Some studies have demonstrated a clear inverse dose–response relationship between exposure to endotoxin and the risk of atopy but this finding has not been reproduced in all studies. Our innate immune system recognizes LPS readily via the LPS signal transduction pathway, which has the trimolecular complex of CD14/TLR4/MD2 at the core. A common single‐nucleotide polymorphism in the promoter region of CD14 rs2569190 C to T (CD14/−260 or CD14/−159) has been associated with elevated sCD14. Although early studies suggested that this variant was associated with more severe atopy, this finding was not uniformly replicated. It has now been demonstrated in four independent populations that high exposure to endotoxin in the domestic environment is protective against the development of atopy, but only among carriers of the C allele, that is, the environmental exposure is only relevant when taken in the context of the genotype. Furthermore, this interaction is biologically plausible. We propose that neither the environmental exposure nor the genotype in isolation is sufficient to cause complex diseases like asthma and atopy, but disease results from the one acting in the context of the other, of which CD14 and endotoxin is one example contributing to the risk for atopy. Cite this as: A. Simpson and F. D. Martinez, Clinical & Experimental Allergy, 2010 (40) 209–223.
Antioxidants and allergic disease: a case of too little or too much?
Authors: Allan K. , Kelly F. J. , Devereux G. 
Published: November 2009

SummarySpeculation persists as to the possible role, if any, of dietary antioxidants in allergic disease. While it has been hypothesized that the recent increase in allergic disease is a consequence of declining dietary antioxidant intake, an alternative hypothesis proposes that the increase in allergic disease is due to increasing antioxidant intake. Dietary trends are conflicting; the intake of some antioxidants has declined, for others intakes are likely to have increased. Animal model studies demonstrate that antioxidant supplementation at the time of primary and subsequent allergen exposure attenuates allergic inflammatory responses. The data from human studies are less clear. Observational epidemiological studies of humans are beset by several methodological limitations associated with the assessment of diet and predominantly focus on asthma. Most observational studies report potentially beneficial associations between dietary antioxidants and allergic outcomes, but a small minority report potentially adverse associations. Human intervention studies suggest that single antioxidant supplements confer minimal, if any clinical benefit in adults with asthma, however, there is still scope for studies in children, atopic dermatitis, allergic rhinitis (AR) and of antioxidant combinations. More recently, it has been suggested that dietary antioxidants in the developmental context of fetal and infant development influence the development childhood asthma and atopic sensitization possibly by affecting the first interactions between the neonatal immune system and allergens. While a small number of birth cohort studies have reported potentially beneficial associations between maternal intake of some antioxidants during pregnancy and childhood asthma, there is very limited data suggesting associations between maternal antioxidant intake and childhood atopic dermatitis and AR. The available epidemiological, animal, molecular and immunological data suggest that there are associations between antioxidants and asthma and to a much lesser extent, atopic dermatitis and AR. However, the exact nature of the relationships and the potential for therapeutic intervention remain unclear. Cite this as: K. Allan, F. J. Kelly and G. Devereux, Clinical & Experimental Allergy, 2010 (40) 370–380.
United airways: circulating Th2 effector cells in an allergic rhinitis model are responsible for promoting lower airways inflammation
Authors: KleinJan A. , Willart M. , Van Nimwegen M. , Leman K. , Hoogsteden H. C. , Hendriks R. W. , Lambrecht B. N. 
Published: November 2009

SummaryBackground
Allergic rhinitis (AR) and asthma often coexist and are referred to as ‘united airways’ disease. However, the molecular and cellular pathways that are crucially involved in the interaction between upper and lower airways remain to be identified.Objective
We sought to assess whether and how AR exacerbates lower airway inflammation upon allergen challenge in mice.Methods
We previously developed an intranasal ovalbumin (OVA)‐driven AR model, characterized by nasal eosinophilic inflammation, enhanced serum levels of OVA‐specific IgE and Th2 cytokine production in cervical lymph nodes. In OVA‐sensitized mice with or without AR, a lower airway challenge was given, and after 24 h, lower airway inflammation was analysed.Results
We found that AR mice were more susceptible to eosinophilic inflammation following a lower airway OVA challenge than OVA‐sensitized controls. AR mice manifested increased numbers of eosinophils in bronchoalveolar lavage fluid and increased inter‐cellular adhesion molecule‐1 (ICAM‐1) expression on lung endothelium, when compared with OVA‐sensitized controls. Depletion of T cells in OVA‐challenged AR mice completely abrogated all hallmarks of lower airway inflammation, including enhanced IL‐5 and tissue eosinophilia. Conversely, adoptive transfer of Th2 effector cells in naïve animals induced lower airway eosinophilic inflammation after challenge with OVA. Blocking T cell recirculation during AR development by the spingosine‐1 analogue FTY720 also prevented lower airway inflammation including ICAM‐1 expression in AR mice upon a single lower airway challenge.Conclusion
Our mouse model of ‘united airways’ disease supports epidemiological and clinical data that AR has a significant impact on lower airway inflammation. Circulating Th2 effector cells are responsible for lung priming in AR mice, most likely through up‐regulation of ICAM‐1. Cite this as: A. KleinJan, M. Willart, M. van Nimwegen, K. Leman, H. C. Hoogsteden, R.W. Hendriks and B.N. Lambrecht, Clinical & Experimental Allergy, 2010 (40) 494–504.
Preserving the biodiversity and ecological services of rivers: new challenges and research opportunities
Authors: ARTHINGTON ANGELA H. , NAIMAN ROBERT J. , McCLAIN MICHAEL E. , NILSSON CHRISTER 
Published: November 2009

Summary1. Natural biogeochemical processes and diverse communities of aquatic biota regulate freshwater quantity and quality in ways that are not sufficiently acknowledged nor appreciated by the water resources management community. The establishment and enforcement of environmental flow requirements offer promising means to improve and care for these critical environmental services. This Special Issue provides new insights and novel techniques to determine, protect and restore ecologically and socially sustainable flow regimes, and thereby help achieve the water‐related goals of the Millennium Ecosystem Assessment.2. Whilst alteration of flow, sediment, organic matter and thermal regimes interact to reduce biological diversity and the ecological integrity of freshwater ecosystems – and thereby degrade the properties and ecological services most valued by humans –‘environmental flows’ left in rivers, or restored to developed rivers, will sustain many ecological and societal values. The success of river protection and rehabilitation/restoration depends upon understanding and accurately modelling relationships between hydrological patterns, fluvial disturbance and ecological responses in rivers and floodplains.3. This Special Issue presents new analytical and modelling approaches to support the development of hydro‐ecological models and environmental flow standards at multiple spatial scales – applicable to all rivers in any economic and societal setting. Examples include the new framework Ecological Limits of Hydrologic Alteration (ELOHA) founded on hydrological classification and gradient analysis; ecological trait analysis; Bayesian hierarchical modelling; Bayesian Decision Networks; and Integrated Basin Flow Assessment (IBFA).4. Advances in the allocation of flood flows along the River Murray in Australia, an Ecosystems Function Model (HEC‐EFM) for the Bill Williams River restoration programme in Arizona (U.S.A), the European Water Framework Directive, and improved management of hydroelectric dams demonstrate the potential for significant ecological recovery following partial restoration of natural river flow regimes.5. Based on contributions to this Special Issue, the action agenda of the 2007 Brisbane Declaration on environmental flows and the wider literature, we propose an invigorated global research programme to construct and calibrate hydro‐ecological models and to quantify the ecological goods and services provided by rivers in contrasting hydro‐climatic settings across the globe. A major challenge will be to find acceptable ways to manage rivers for multiple uses. Climate change intensifies the urgency. Environmental flows help to preserve the innate resilience of aquatic ecosystems, and thereby offer the promise of improved sustainability and wellbeing for people as well as for ecosystems.
How well are velocity effects on ∂13C signatures transmitted up the food web from algae to fish?
Authors: RASMUSSEN JOSEPH B. , TRUDEAU VERONIQUE 
Published: November 2009

Summary1. Benthic algae fractionate carbon isotopes less at low water velocities because of reduced boundary layer exchange, and this effect on δ13C is passed on to consumers via trophic transfer. This study examines the relationships between δ13C signatures of consumers (invertebrates and salmonid fishes) and water velocity in the Sainte Marguerite River, QC, Canada, and compares them to patterns for periphyton, both along the river main‐stem and in a small tributary.2. Relationships of δ13C signatures of herbivore/grazers and collector/gatherers with water velocity were strong and similar to those of periphyton, but relationships for filter‐feeders were weak, probably reflecting the effect of spatial averaging of their food supply as a result of downstream transport.3. Velocity effects on salmonid signatures were much weaker than those of lower trophic levels, being barely significant except in the small tributary where the fish were resident and isolated from the main river. In the river main‐stem, even when reach standardised (reach mean subtracted from each data point), fish signatures were only weakly related to water velocity.4. The fidelity with which velocity effects are transmitted to consumers from benthic algae is highly variable, and depends on a combination of consumer and resource movements, in addition to the trophic position of the consumer.
The effect of diet on the expression of lipase genes in the midgut of the lightbrown apple moth (Epiphyas postvittana Walker; Tortricidae)
Authors: Christeller J. T. , Poulton J. , Markwick N. M. , Simpson R. M. 
Published: November 2009

AbstractWe have identified lipase‐like genes from an Epiphyas postvittana larval midgut EST library. Of the 10 pancreatic lipase family genes, six appear to encode active lipases and four encode inactive lipases, based on the presence/absence of essential catalytic residues. The four gastric lipase family genes appear to encode active proteins. Phylogenetic analysis of 54 lepidopteran pancreatic lipase proteins resolved the clade into five groups of midgut origin and a sixth of non‐midgut lipases. The inactive proteins formed two separate groups with highly conserved mutations. The lepidopteran midgut lipases formed a ninth subfamily of pancreatic lipases. Eighteen insect and human gastric lipases were analysed phylogenetically with only very weak support for any groupings. Gene expression was measured in the larval midgut following feeding on five artificial diets and on apple leaves. The artificial diets contained different levels of triacylglycerol, linoleic acid and cholesterol. Significant changes in gene expression (more than 100‐fold for active pancreatic lipases) were observed. All the inactive lipases were also highly expressed. The gastric lipase genes were expressed at lower levels and suppressed in larvae feeding on leaves. Together, protein motif analysis and the gene expression data suggest that, in phytophagous lepidopteran larvae, the pancreatic lipases may function in vivo as galactolipases and phospholipases whereas the gastric lipases may function as triacylglycerol hydrolases.
A diversity of putative carboxylesterases are expressed in the antennae of the noctuid mothSpodoptera littoralis
Authors: Durand N. , Carot‐Sans G. , Chertemps T. , Montagné N. , Jacquin‐Joly E. , Debernard S. , Maïbèche‐Coisne M. 
Published: November 2009

AbstractRecent studies have suggested that pheromone‐degrading enzymes belonging to the carboxylesterase family could play a role in the dynamics of the olfactory response to acetate sex pheromones in insects. Bioinformatic analyses of a male antennal expressed sequence tag library allowed the identification of 19 putative esterase genes expressed in the antennae of the mothSpodoptera littoralis. Phylogenetic analysis revealed that these genes belong to different insect esterase clades, defined by their putative cellular localization and substrate preferences. Interestingly, two of the 19 genes appeared to be antennal specific, suggesting a specific role in olfactory processing. This high esterase diversity suggested that the antennae are the location for intense esterase‐based metabolism, against potentially a large range of exogenous and endogenous molecules.
Gene expression associated with changes in cold tolerance levels of the Antarctic springtail, Cryptopygus antarcticus
Authors: Burns G. , Thorne M. A. S. , Hillyard G. , Clark M. S. , Convey P. , Worland M. R. 
Published: November 2009

AbstractThe ability of the Antarctic microarthropod Cryptopygus antarcticus (Collembola, Isotomidae) to survive low temperatures has been well studied at the physiological level, with recent investigations indicating the importance of the moulting process in conferring this ability. This study investigated gene expression in groups of C. antarcticus that have distinct differences in their ability to survive low temperatures. A microarray containing c. 5400 C. antarcticus expressed sequence tags was used to investigate gene expression differences between groups of animals with different supercooling points (SCP), and to low temperatures close to their SCP. By demonstrating the involvement of moult‐related genes in the differential survival of two groups of C. antarcticus with distinct SCP profiles, the results of this investigation add support to the suggestion that moulting plays a role in conferring cold tolerance in C. antarcticus.
Extensive gene duplication of acetylcholinesterase associated with organophosphate resistance in the two‐spotted spider mite
Authors: Kwon D. H. , Clark J. M. , Lee S. H. 
Published: November 2009

AbstractMonocrotophos‐resistant two‐spotted spider mites (TSSMs), Tetranychus urticae, are known to possess three mutations on the acetylcholinesterase (AChE) gene (Tuace) that are involved in target site insensitivity. Cross‐strain comparison of three strains (highly resistant AD, moderately resistant PyriF and susceptible UD strains) revealed that resistant strains have relatively more Tuace copies than the UD strain and that the levels of transcript were directly proportional to copy numbers. AChEs from the AD and PyriF strains had similar Vmax values to those of AChE from the UD strain but increased Km and reduced kcat constants, suggesting that the mutated, resistant form of AChE may carry a fitness cost. Relative copy numbers of Tuace in field populations varied from 2.4 to 6.1, correlating well with their levels of resistance (r2= 0.895). These results are suggestive of the involvement of Tuace gene duplication in resistance. Thus, monocrotophos resistance in TSSMs appears to have evolved through a combination of mutation accumulation and extensive gene duplication.
Yellow fever mosquito sterol carrier protein‐2 gene structure and transcriptional regulation
Authors: Vyazunova I. , Lan Q. 
Published: December 2009

AbstractAeSCP‐2, a sterol carrier protein, is involved in sterol trafficking in mosquitoes. The activity of the AeSCP‐2 gene is important for mosquito development. An earlier study demonstrated that the transcription of this gene was upregulated by 20‐hydroxyecdysone (20E) in cultured gut tissues. To investigate 20E‐regulated transcription of the AeSCP‐2 gene we truncated the upstream flanking region of AeSCP‐2 gene and linked it to a reporter gene. The mosquito Aag‐2 cell line was transfected with these promoter/reporter constructs and treated with 20E at various concentrations. Expression vectors of different transcription factors such as HR3 and βFTZ‐F1 were also co‐transfected with the AeSCP‐2 promoter/reporter constructs. The observed results demonstrated that varied combinations of transcription factors produce different promoter activities of the AeSCP‐2 gene. This observation leads us to the conclusion that the partnership of transcription factors is crucial in regulating the transcriptional activity of the AeSCP‐2 gene.