bluuebunny/crossref_metadata_2025_split huggingface dataset:
Macro-scale phenomena of arterial coupled cells: a massively parallel simulation
Authors: Shaikh Mohsin Ahmed , Wall David J. N. , David Tim 
Published: September 2011

Impaired mass transfer characteristics of blood-borne vasoactive species such as adenosine triphosphate in regions such as an arterial bifurcation have been hypothesized as a prospective mechanism in the aetiology of atherosclerotic lesions. Arterial endothelial cells (ECs) and smooth muscle cells (SMCs) respond differentially to altered local haemodynamics and produce coordinated macro-scale responses via intercellular communication. Using a computationally designed arterial segment comprising large populations of mathematically modelled coupled ECs and SMCs, we investigate their response to spatial gradients of blood-borne agonist concentrations and the effect of micro-scale-driven perturbation on the macro-scale. Altering homocellular (between same cell type) and heterocellular (between different cell types) intercellular coupling, we simulated four cases of normal and pathological arterial segments experiencing an identical gradient in the concentration of the agonist. Results show that the heterocellular calcium (Ca
2+
) coupling between ECs and SMCs is important in eliciting a rapid response when the vessel segment is stimulated by the agonist gradient. In the absence of heterocellular coupling, homocellular Ca
2+
coupling between SMCs is necessary for propagation of Ca
2+
waves from downstream to upstream cells axially. Desynchronized intracellular Ca
2+
oscillations in coupled SMCs are mandatory for this propagation. Upon decoupling the heterocellular membrane potential, the arterial segment looses the inhibitory effect of ECs on the Ca
2+
dynamics of the underlying SMCs. The full system comprises hundreds of thousands of coupled nonlinear ordinary differential equations simulated on the massively parallel Blue Gene architecture. The use of massively parallel computational architectures shows the capability of this approach to address macro-scale phenomena driven by elementary micro-scale components of the system.
Glutamine Synthetase Is a Molecular Target of Nitric Oxide in Root Nodules of Medicago truncatula and Is Regulated by Tyrosine Nitration
Authors: Melo Paula M. , Silva Liliana S. , Ribeiro Isa , Seabra Ana R. , Carvalho Helena G. 
Published: September 2011

Abstract
Nitric oxide (NO) is emerging as an important regulatory player in the Rhizobium-legume symbiosis, but its biological role in nodule functioning is still far from being understood. To unravel the signal transduction cascade and ultimately NO function, it is necessary to identify its molecular targets. This study provides evidence that glutamine synthetase (GS), a key enzyme for root nodule metabolism, is a molecular target of NO in root nodules of Medicago truncatula, being regulated by tyrosine (Tyr) nitration in relation to active nitrogen fixation. In vitro studies, using purified recombinant enzymes produced in Escherichia coli, demonstrated that the M. truncatula nodule GS isoenzyme (MtGS1a) is subjected to NO-mediated inactivation through Tyr nitration and identified Tyr-167 as the regulatory nitration site crucial for enzyme inactivation. Using a sandwich enzyme-linked immunosorbent assay, it is shown that GS is nitrated in planta and that its nitration status changes in relation to active nitrogen fixation. In ineffective nodules and in nodules fed with nitrate, two conditions in which nitrogen fixation is impaired and GS activity is reduced, a significant increase in nodule GS nitration levels was observed. Furthermore, treatment of root nodules with the NO donor sodium nitroprusside resulted in increased in vivo GS nitration accompanied by a reduction in GS activity. Our results support a role of NO in the regulation of nitrogen metabolism in root nodules and places GS as an important player in the process. We propose that the NO-mediated GS posttranslational inactivation is related to metabolite channeling to boost the nodule antioxidant defenses in response to NO.
Tissue-Specific Expression of FLOWERING LOCUS T in Arabidopsis Is Maintained Independently of Polycomb Group Protein Repression
Authors: Farrona Sara , Thorpe Frazer L. , Engelhorn Julia , Adrian Jessika , Dong Xue , Sarid-Krebs Liron , Goodrich Justin , Turck Franziska 
Published: September 2011

Abstract
The Polycomb Group (PcG) pathway represses transcription through a mechanism conserved among plants and animals. PcG-mediated repression can determine spatial territories of gene expression, but it remains unclear whether PcG-mediated repression is a regulatory requirement for all targets. Here, we show the role of PcG proteins in the spatial regulation of FLOWERING LOCUS T (FT), a main activator of flowering in Arabidopsis thaliana exclusively expressed in the vasculature. Strikingly, the loss of PcG repression causes down-regulation of FT. In addition, our results show how the effect of PcG-mediated regulation differs for target genes and that, for FT expression, it relies primarily on tissue differentiation.
The Xanthomonas Type III Effector XopD Targets the Arabidopsis Transcription Factor MYB30 to Suppress Plant Defense
Authors: Canonne Joanne , Marino Daniel , Jauneau Alain , Pouzet Cécile , Brière Christian , Roby Dominique , Rivas Susana 
Published: September 2011

Abstract
Plant and animal pathogens inject type III effectors (T3Es) into host cells to suppress host immunity and promote successful infection. XopD, a T3E from Xanthomonas campestris pv vesicatoria, has been proposed to promote bacterial growth by targeting plant transcription factors and/or regulators. Here, we show that XopD from the B100 strain of X. campestris pv campestris is able to target MYB30, a transcription factor that positively regulates Arabidopsis thaliana defense and associated cell death responses to bacteria through transcriptional activation of genes related to very-long-chain fatty acid (VLCFA) metabolism. XopD specifically interacts with MYB30, resulting in inhibition of the transcriptional activation of MYB30 VLCFA-related target genes and suppression of Arabidopsis defense. The helix-loop-helix domain of XopD is necessary and sufficient to mediate these effects. These results illustrate an original strategy developed by Xanthomonas to subvert plant defense and promote development of disease.
Changes in Twelve Homoeologous Genomic Regions in Soybean following Three Rounds of Polyploidy
Authors: Severin Andrew J. , Cannon Steven B. , Graham Michelle M. , Grant David , Shoemaker Randy C. 
Published: September 2011

Abstract
With the advent of high-throughput sequencing, the availability of genomic sequence for comparative genomics is increasing exponentially. Numerous completed plant genome sequences enable characterization of patterns of the retention and evolution of genes within gene families due to multiple polyploidy events, gene loss and fractionation, and differential evolutionary pressures over time and across different gene families. In this report, we trace the changes that have occurred in 12 surviving homoeologous genomic regions from three rounds of polyploidy that contributed to the current Glycine max genome: a genome triplication before the origin of the rosids (~130 to 240 million years ago), a genome duplication early in the legumes (~58 million years ago), and a duplication in the Glycine lineage (~13 million years ago). Patterns of gene retention following the genome triplication event generally support predictions of the Gene Balance Hypothesis. Finally, we find that genes in networks with a high level of connectivity are more strongly conserved than those with low connectivity and that the enrichment of these highly connected genes in the 12 highly conserved homoeologous segments may in part explain their retention over more than 100 million years and repeated polyploidy events.
Spatial patterns of the ant Crematogaster scutellaris in a model ecosystem
Authors: SANTINI GIACOMO , RAMSAY PAUL M. , TUCCI LORENZO , OTTONETTI LORENZO , FRIZZI FILIPPO 
Published: September 2011

1. The spatial arrangement of individuals and populations may have deep influences on all the biotic interactions within a community.2. The spatial distribution of nests of the ant Crematogaster scutellaris Olivier was analysed in an olive orchard in central Italy. As this species nests inside tree trunks, the regular structure of this simplified ecosystem may help to reduce the confounding effect of habitat heterogeneity on the spatial distribution of nests. In total, 531 trees were mapped and their shape (size and structure of the trunk) recorded. The presence of C. scutellaris nests in each tree was assessed in spring–summer and autumn 2006 and 2007.3. The number of occupied trees changed in time, from a maximum of 129 (summer 2006) to a minimum of 60 (autumn 2007). Occupancy of tree was related to its shape, with larger trees being more frequently and more steadily occupied than smaller ones.4. Nests were spatially aggregated, forming well‐defined clusters, but aggregation was not explained by a corresponding clumping of larger trees. Nests belonging to the same cluster were usually not aggressive to each other, whereas aggression was more common between nests belonging to different clusters. The dynamic nature of the system coupled with the clustered distribution of nests, is consistent with a hypothesis of seasonal polydomy, and suggest that whereas some trees are steadily occupied (core) others are opportunistically colonised when new resources are discovered (satellites).5. Clusters size distribution was shown to follow a truncated power‐law, a finding consistent with the idea that clusters are self‐organised structures dependent on local interactions. These results suggest that spatial self‐organisation in ant colonies may in principle be more common than previously thought, although the mechanisms generating these patterns still need to be clarified.
The role of leaf defensive traits in oaks on the preference and performance of a polyphagous herbivore, Orgyia vetusta
Authors: PEARSE IAN S. 
Published: September 2011

1. Leaves possess traits that mediate the preference and performance of herbivores. Most evidence for the importance of leaf traits as defences against herbivory comes from studies of few model plant species.2. In a phylogenetically explicit comparison, I explain the differences in preference and performance of tussock moth (Orgyia vetusta Boisduval) larvae on leaves of 27 oak (Quercus) species using nine putative leaf defences.3. The preference for an oak species correlated positively with the survival of caterpillars. The correlation between preference and performance did not differ between oak species native to the range of tussock moth versus those from outside the herbivore's range.4. The first principal component of leaf traits predicted survival of caterpillars on oak leaves but only marginally predicted their preference between oak species. A multiple regression model showed that evergreenness, toughness, and condensed tannin content were the best predictors of caterpillar survival, and leaf toughness was the best predictor of host preference.5. Generalist caterpillars may accurately assess the value of novel food sources. Moreover, many leaf traits that have been found to affect herbivory within a plant species can also be used to predict the fitness of a generalist herbivore between species.
Vector preference for hosts differing in infection status: sharpshooter movement and Xylella fastidiosa transmission
Authors: DAUGHERTY MATTHEW P. , RASHED ARASH , ALMEIDA RODRIGO P. P. , PERRING THOMAS M. 
Published: September 2011

1. Epidemiological theory predicts that vector preference for hosts differing in infection status (i.e. healthy or infected) affects disease dynamics.2. Numerous studies have documented strong vector preference for or discrimination against infected hosts. However, the significance of these behaviours for pathogen transmission and spread has been poorly described.3. We conducted a series of choice assays to evaluate orientation preference, feeding preference, and movement rates of an important group of vectors, the sharpshooter leafhoppers, based on host infection status for the generalist plant pathogen, Xylella fastidiosa Wells et al.4. Sharpshooters did not discriminate between healthy versus infected‐but‐asymptomatic grapevines, but they oriented preferentially to healthy grapevines more frequently than either symptomatic vines or those artificially coloured to mimic disease symptoms.5. In a field trial three sharpshooter species showed different movement rates and preferences for feeding site, but all species exhibited similar and significant preference for healthy hosts.6. Although there was no significant difference in acquisition efficiency among vector species, those individuals that spent more time on healthy hosts tended to be less likely to acquire the pathogen.7. These results suggest that sharpshooters discriminate against infected grapevines, which are likely to be of poorer quality, with visual cues playing a role in host selection. Preference by these vectors may affect pathogen acquisition, which could affect disease spread in the field.
Arboreality and the evolution of disease resistance in ants
Authors: WALKER THOMAS N. , HUGHES WILLIAM O. H. 
Published: September 2011

1. Parasites are an important selective force for almost all organisms and drive the evolution by hosts of defence mechanisms that are energetically costly. The strength of parasitism will vary between host species according to their specific ecology and life history, and so the optimal investment in costly resistance mechanisms is also likely to vary between host species with differing ecologies.2. Parasites are particularly important for social species such as ants, but very little is known about the strength of selection in different species. It has been suggested that, because arboreality reduces exposure to soil‐borne fungal pathogens, arboreal ant species may invest less in disease resistance. However, testing hypotheses such as this requires data on disease resistance in multiple species, and such studies have not previously been attempted.3. Here we examine the arboreality hypothesis by comparing the disease resistance of seven Neotropical ant species with different degrees of arboreality. We exposed ants to controlled doses of the generalist, virulent fungal parasite,Metarhizium anisopliae(Metchnikoff) Sorokin. We then monitored survival, parasite sporulation, and the anti‐fungal grooming response of the ants.4. Contrary to the hypothesis, we found that arboreal species were not less resistant toM. anisopliaethan species that were ground‐dwelling, and that the species that inhabited both arboreal and ground habitats had the greatest resistance. Surprisingly, the most resistant species was one that lacked the antibiotic‐producing metapleural gland, previously considered the lynchpin of disease resistance in ants.5. The results suggest that it may be the diversity of parasites encountered that is the greatest selection pressure. Further experimental studies with other parasites are needed to confirm the generality of the results, and similar comparative studies of other taxa are needed to understand the relationship between host ecology and the evolution of disease resistance.
Nutritional and anti‐nutritional compositions of defatted Nebraska hybrid hazelnut meal
Authors: Xu Yixiang , Hanna Milford A. 
Published: September 2011

SummaryDefatted meal of hybrid hazelnuts may have potential food and value‐added industrial applications. The proximate composition, mineral elements, amino acid profile and anti‐nutritional factors (total phenolics, tannins, condensed tannins and phytates) of defatted meals of ten Nebraska hybrid hazelnut genotypes were investigated. Excluding the amino acid profile, the nutritional and anti‐nutritional compositions of the meals differed significantly, with high protein, carbohydrate, neutral and acid detergent fibre concentrations and energy value. Mineral concentrations were higher than those previously reported. K was the most abundant mineral element, followed by P, Ca and Mg. Seven essential amino acids accounted for approximately 27.8% of the total amino acid contents. Tryptophan was not detected. All essential amino acid contents were significantly lower than the reference levels recommended for human and animal consumption. The high levels of anti‐nutritional factors, such as total phenolics, tannins, condensed tannins and phytate in the meals, could reduce protein and mineral bioavailability.
Optimisation of a new two‐plate screening method for the detection of antibiotic residues in meat
Authors: Dang Pham K. , Degand Guy , Douny Caroline , Ton Vu D. , Maghuin‐Rogister Guy , Scippo Marie‐Louise 
Published: September 2011

SummaryA two‐plate microbiological method to screen residues of the most commonly used antibiotics in animal production, named new two‐plate test (NTPT), has been optimised and validated, according to criteria derived from the European Commission Decision 2002/657/CE. This screening method used two media at different pH seeded with a single bacteria strain (Bacillus subtilis). The method consists of a simple extraction, followed by the application of the extract on Petri plates. The method detected, in pork and chicken muscles, most of the antibiotics from six groups (tetracyclines, (fluoro)quinolones, penicillins, macrolides, aminoglycosides and sulfonamides) and florfenicol at concentration very close to maximum residue limits used in the EU. The screening capacity of the NTPT was compared with another screening technique, the Premi‐Test®, by analysing spiked samples as well as real samples of meat from pork and chicken sold for local consumption, in the Red River Delta region (Vietnam). The NTPT described here appeared to detect more samples than the Premi‐Test®, showing its interest for Vietnamese control laboratories, as a screening method to monitor antibiotic residues in chicken and pork meat, before sending the suspected samples to the confirmatory step.
Influence of the commercial processing and floral origin on bioactive and nutritional properties of honeybee‐collected pollen
Authors: Domínguez‐Valhondo Diana , Bohoyo Gil Diego , Hernández María Teresa , González‐Gómez David 
Published: September 2011

SummaryPollen is characterised for having a low fat content, a relatively high content of dietary fibre and an important amount of minerals and essential amino acids. With regard to bioactive compounds, honeybee‐collected pollen exhibits an important source of phytochemical compounds and antioxidant activity. The purpose of this research was to study how the nutritional properties and the stability of the bioactive compounds found in honeybee‐collected pollen were affected by the commercial processing and its floral origin. To achieve this goal, pollen pellets of different floral origin were harvested directly from hives and immediately stored at −80 °C. Pollen pellets were dried by placing them into hot‐air chambers (traditional drying methodology) or by means of freeze‐drying. We found a slight influence of floral origin on the nutritional properties of pollen pellets (multifloral pollen had higher contents of fat, carbohydrates, proteins and mineral elements than monofloral‐type pollen), whereas the abundance of bioactive compounds was correlated with the origin factor as well as the methodology employed to dry the fresh pollen pellets, especially carotenoid pigments such as lutein (5.73 ± 1.80, 4.93 ± 1.16 and 0.81 ± 0.16 μg of lutein per g of pollen for fresh, lyophilised and hot‐air‐dried multifloral pollen).
Predictors of complementary and alternative medicine use by people with type 2 diabetes
Authors: Chang Hsiao‐Yun Annie , Wallis Marianne , Tiralongo Evelin 
Published: September 2011

chang h.‐y.a., wallis m. & tiralongo e. (2012) Predictors of complementary and alternative medicine use by people with type 2 diabetes. Journal of Advanced Nursing68(6), 1256–1266.AbstractAims.  This paper is a report of a study into factors predicting complementary and alternative medicine use in people with type 2 diabetes.Background.  The growing incidence of type 2 diabetes is emerging as a major health issue throughout the world. While the rate of complementary and alternative medicine use in this population is high, it is not clear what predicts its use, in this population.Methods.  A cross‐sectional survey, using a structured interview, was undertaken among people with type 2 diabetes attending diabetic clinics in three census regions in Taiwan, between July 2006 and February 2007. The survey instrument, derived from a review of Taiwanese and international literature, was developed using the Health Belief Model.Results.  A total of 326 participants with type 2 diabetes were interviewed (87·4% response rate). In people with type 2 diabetes, complementary and alternative medicine use was associated with a history of its use, a positive attitude towards it, stronger health beliefs about diabetes and the efficacy of complementary and alternative medicine in treating diabetes, a higher degree of self‐care activities by the individual and a longer duration of diabetes.Conclusions.  The results of this study indicate that complementary and alternative medicine use in people with type 2 diabetes is influenced by people’s experience, beliefs, attitudes towards complementary and alternative medicine, and their behaviour towards disease management rather than their demographic characteristics. Nurses and healthcare professionals should consider the patient’s background, health history, health beliefs and cultural background when planning specific strategies designed to modify lifestyle.