Showing papers by "University of Guelph published in 2009"
Royal Botanic Garden Edinburgh1, National Institutes of Health2, University of Guelph3, University of Johannesburg4, Royal Botanic Gardens5, Smithsonian Institution6, University of British Columbia7, Natural History Museum8, Korea University9, University of Toronto10, State University of Feira de Santana11, University of Costa Rica12, Columbus State University13, University of Wisconsin-Madison14, New York Botanical Garden15, University of the Andes16, University of Cape Town17, Seoul National University18, Hallym University19, National Autonomous University of Mexico20, Imperial College London21
TL;DR: The 2-locus combination of rbcL+matK will provide a universal framework for the routine use of DNA sequence data to identify specimens and contribute toward the discovery of overlooked species of land plants.
Abstract: DNA barcoding involves sequencing a standard region of DNA as a tool for species identification. However, there has been no agreement on which region(s) should be used for barcoding land plants. To provide a community recommendation on a standard plant barcode, we have compared the performance of 7 leading candidate plastid DNA regions (atpF–atpH spacer, matK gene, rbcL gene, rpoB gene, rpoC1 gene, psbK–psbI spacer, and trnH–psbA spacer). Based on assessments of recoverability, sequence quality, and levels of species discrimination, we recommend the 2-locus combination of rbcL+matK as the plant barcode. This core 2-locus barcode will provide a universal framework for the routine use of DNA sequence data to identify specimens and contribute toward the discovery of overlooked species of land plants.
2,255 citations
TL;DR: A review of the available science on the effects of N source, rate, timing, and placement, in combination with other cropping and tillage practices, on GHG emissions was conducted as mentioned in this paper.
1,203 citations
TL;DR: Genotypes for 38,416 markers and August 2003 genetic evaluations for 3,576 Holstein bulls born before 1999 were used to predict January 2008 daughter deviations and genomic prediction improves reliability by tracing the inheritance of genes even with small effects.
1,166 citations
Christine G. Elsik1, Christine G. Elsik2, Christine G. Elsik3, Ross L. Tellam3 +325 more•Institutions (65)
TL;DR: To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage and provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
Abstract: To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
1,144 citations
University of Hertfordshire1, University of Alabama at Birmingham2, University of Helsinki3, University of South Florida4, University of Glasgow5, University of Kentucky6, Leiden University Medical Center7, Institute for Animal Health8, University of Guelph9, Katholieke Universiteit Leuven10, Pasteur Institute11, Agriculture and Agri-Food Canada12, University of Bristol13, University of Edinburgh14, Queen's University15
TL;DR: Changes to virus taxonomy approved and ratified by the International Committee on Taxonomy of Viruses in February 2015 are listed.
Abstract: Changes to virus taxonomy approved and ratified by the International Committee on Taxonomy of Viruses in February 2015 are listed.
1,039 citations
TL;DR: Contrary to expectations, information disclosure and information control were not significantly negatively correlated, and multiple regression analyses revealed that while disclosure was significantly predicted by the need for popularity, levels of trust and self-esteem predicted information control.
Abstract: Facebook, the popular social network site, is changing the nature of privacy and the consequences of information disclosure. Despite recent media reports regarding the negative consequences of disclosing information on social network sites such as Facebook, students are generally thought to be unconcerned about the potential costs of this disclosure. The current study explored undergraduate students' information disclosure and information control on Facebook and the personality factors that influence levels of disclosure and control. Participants in this online survey were 343 undergraduate students who were current users of Facebook. Results indicated that participants perceived that they disclosed more information about themselves on Facebook than in general, but participants also reported that information control and privacy were important to them. Participants were very likely to have posted information such as their birthday and e-mail address, and almost all had joined an online network. Th...
688 citations
TL;DR: This chapter describes the classical overlay protocol, which is fundamental to many protocols in phage biology, genetics, and molecular biology.
Abstract: The determination of the concentration of infectious phage particles is fundamental to many protocols in phage biology, genetics, and molecular biology. In this chapter the classical overlay protocol is described.
665 citations
TL;DR: Serum BHBA concentrations at or above 1,200 micromol/L in the first week following calving were associated with increased risks of subsequent displaced abomasum and metritis, and the best threshold for predicting subsequent risk of clinical ketosis from serum obtained during wk 1 and wk 2 postpartum was 1,400 micromols/L.
613 citations
University of California, Santa Cruz1, National Institutes of Health2, Broad Institute3, University of Los Andes4, University of Guelph5, University of Nottingham6, University of California, Berkeley7, Pennsylvania State University8, Royal Ontario Museum9, Texas A&M University10, Louisiana State University11, Agency for Science, Technology and Research12, University of Kansas13, University of Montana14, American Museum of Natural History15, Oregon State University16, Villanova University17, University of Porto18, Smithsonian Institution19, Oswaldo Cruz Foundation20, Okinawa Institute of Science and Technology21, University of Sheffield22, Harvard University23, Swedish Museum of Natural History24, University of Copenhagen25, Novosibirsk State University26, Australian National University27, Max Planck Society28, Field Museum of Natural History29, Commonwealth Scientific and Industrial Research Organisation30, Science Applications International Corporation31, Stanford University32, University of Illinois at Urbana–Champaign33, George Washington University34, Global Viral35, University of Bedfordshire36, Federal University of Rio de Janeiro37, University of California, Davis38, University of California, Riverside39, Museum Victoria40, University College Dublin41, Monterey Bay Aquarium Research Institute42, Washington University in St. Louis43, University of California, Los Angeles44, Kunming Institute of Zoology45
TL;DR: A precipitous drop in costs and increase in sequencing efficiency is anticipated, with concomitant development of improved annotation technology, and it is proposed to create a collection of tissue and DNA specimens for 10,000 vertebrate species specifically designated for whole-genome sequencing in the very near future.
Abstract: American Genetic Association, Gordon and Betty Moore Foundation, NHGRI Intramural Sequencing Center, and UCSC Alumni Association to cost of the Genome 10K workshop; Howard Hughes Medical Institute to D. H.; Gordon and Betty Moore Foundation to S. C. S.; A
545 citations
TL;DR: The results confirmed the importance of knowing the carrier and removal status of canine coronavirus, as a source of infection for other animals, not necessarily belonging to the ABC Superfamily.
Abstract: 3.2. Other Potential in vivo Functions of Pgp 2992 3.3. Physiological Role of ABCG2 2992 3.4. Physiological Role of MRP1 2992 4. Structure of ABC Superfamily Drug Efflux Pumps 2992 4.1. Domain Structure of ABC Proteins 2992 4.2. Structure of Entire Bacterial ABC Proteins 2993 4.3. Structure of Pgp, MRP1, and ABCG2 2994 5. Substrate Specificity of ABC Drug Efflux Pumps 2995 5.1. MDR Spectrum Substrates 2995 5.2. Binding and Transport of Drugs 2998 5.3. Multidrug-Binding Pockets 2998 6. Catalytic Cycle of ABC Drug Efflux Pumps 3000 6.1. ATP Binding and Hydrolysis 3000 6.2. Occluded Nucleotide Conformation of Pgp 3000 6.3. Role of NBD Dimerization and the Occluded Conformation in the Catalytic Cycle of Pgp 3000
515 citations
TL;DR: This study provides evidence of Facebook's unique contributions to the experience of jealousy in romantic relationships and argues that this effect may be the result of a feedback loop whereby using Facebook exposes people to often ambiguous information about their partner that they may not otherwise have access to and that this new information incites further Facebook use.
Abstract: The social network site Facebook is a rapidly expanding phenomenon that is changing the nature of social relationships. Anecdotal evidence, including information described in the popular media, suggests that Facebook may be responsible for creating jealousy and suspicion in romantic relationships. The objectives of the present study were to explore the role of Facebook in the experience of jealousy and to determine if increased Facebook exposure predicts jealousy above and beyond personal and relationship factors. Three hundred eight undergraduate students completed an online survey that assessed demographic and personality factors and explored respondents' Facebook use. A hierarchical multiple regression analysis, controlling for individual, personality, and relationship factors, revealed that increased Facebook use significantly predicts Facebook-related jealousy. We argue that this effect may be the result of a feedback loop whereby using Facebook exposes people to often ambiguous information ...
TL;DR: In this article, a relativistic theory of Love numbers is presented for compact bodies with strong internal gravities. But the theory is not applicable to non-rotating black holes.
Abstract: In Newtonian gravitational theory, a tidal Love number relates the mass multipole moment created by tidal forces on a spherical body to the applied tidal field. The Love number is dimensionless, and it encodes information about the body's internal structure. We present a relativistic theory of Love numbers, which applies to compact bodies with strong internal gravities; the theory extends and completes a recent work by Flanagan and Hinderer, which revealed that the tidal Love number of a neutron star can be measured by Earth-based gravitational-wave detectors. We consider a spherical body deformed by an external tidal field, and provide precise and meaningful definitions for electric-type and magnetic-type Love numbers; and these are computed for polytropic equations of state. The theory applies to black holes as well, and we find that the relativistic Love numbers of a nonrotating black hole are all zero.
TL;DR: Examples from the literature, wherein co-expression has been used to corroborate and discover various aspects of plant biology are presented, and statistical issues including how normalization of gene expression data can influence co- expression results are discussed.
Abstract: Gene co-expression analysis has emerged in the past 5 years as a powerful tool for gene function prediction. In essence, co-expression analysis asks the question 'what are the genes that are co-expressed, that is, those that show similar expression profiles across many experiments, with my gene of interest?'. Genes that are highly co-expressed may be involved in the biological process or processes of the query gene. This review describes the tools that are available for performing such analyses, how each of these perform, and also discusses statistical issues including how normalization of gene expression data can influence co-expression results, calculation of co-expression scores and P values, and the influence of data sets used for co-expression analysis. Finally, examples from the literature will be presented, wherein co-expression has been used to corroborate and discover various aspects of plant biology.
TL;DR: It is found that habitat specialists responded primarily to environmental factors and habitat generalists responded mainly to spatial factors, which infer that a natural metacommunity can exhibit complicated dynamics, with some groups of species governed according to environmental processes and other groups governed mainly by dispersal processes.
Abstract: Emergence of the metacommunity concept has made a substantial contribution to better understanding of the community composition and dynamics in a regional context. However, long-term field data for testing of available metacommunity models are still scarce, and the extent to which these models apply to the real world remains unknown. Tests conducted so far have largely sought to fit data on the entire regional set of species to one of several metacommunity models, implicitly assuming that all species operate similarly over the same set of sites. However, species differ in their habitat use. These differences can, in the most general terms, be expressed as a gradient of habitat specialization (ranging from habitat specialists to habitat generalists). We postulate that such differences in habitat specialization will have implications for metacommunity dynamics. Specifically, we predict that specialists respond more to local processes and generalists respond to regional spatial processes. We tested these predictions using natural microcosm communities for which long-term (nine-year) environmental and population dynamics data were available. We used redundancy analysis to determine the proportion of variation explained by environmental and spatial factors. We repeated this analysis to explain variation in the entire regional set of species, in generalist species only, and in specialists only. We further used ANOVA to test for differences in the proportions of explained variation. We found that habitat specialists responded primarily to environmental factors and habitat generalists responded mainly to spatial factors. Thus, from the metacommunity perspective, the dynamics of habitat specialists are best explained by a combination of species sorting and mass effects, while that of habitat generalists are best explained by patch dynamics and neutral models. Consequently, we infer that a natural metacommunity can exhibit complicated dynamics, with some groups of species (e.g., habitat specialists) governed according to environmental processes and other groups (e.g., habitat generalists) governed mainly by dispersal processes.
TL;DR: It is shown how successful invader establishment depends on either a fitness advantage or niche difference from resident species, but that only the former allows invaders to become dominant.
Abstract: Summary 1. For plant invaders, being different is often equated with being successful, yet the mechanistic connection remains unclear. 2. Classic niche theory predicts that invaders with niches distinct from the native flora should coexist with little interaction with native species, yet such invaders often have substantial impacts. Meanwhile, invaders that overlap in niche space with native species should either be repelled or dominate, yet these invaders often naturalize with little effect. Such discrepancies between theory and observation raise questions about how species differences influence invader establishment and impact. 3. Here, we review these issues in light of recent work on coexistence theory, which shows how niche and fitness differences between natives and invaders interact to determine invasion outcomes. We show how successful invader establishment depends on either a fitness advantage or niche difference from resident species, but that only the former allows invaders to become dominant. 4. By identifying the role of niche and fitness differences in leading invasion hypotheses, we unify their predictions for invasion success while highlighting new approaches for evaluating the importance of species differences for invasion. 5. Synthesis. Situating the invasion process within a recent coexistence framework broadens our understanding of invasion mechanisms and more tightly links problems in invasion ecology with our more general understanding of community dynamics.
TL;DR: An overview of the basic process of natural selection is provided, the extent and possible causes of misunderstandings of the process are discussed, and a review of the most common misconceptions that must be corrected before a functional understanding ofnatural selection and adaptive evolution can be achieved.
Abstract: Natural selection is one of the central mechanisms of evolutionary change and is the process responsible for the evolution of adaptive features. Without a working knowledge of natural selection, it is impossible to understand how or why living things have come to exhibit their diversity and complexity. An understanding of natural selection also is becoming increasingly relevant in practical contexts, including medicine, agriculture, and resource management. Unfortunately, studies indicate that natural selection is generally very poorly understood, even among many individuals with postsecondary biological education. This paper provides an overview of the basic process of natural selection, discusses the extent and possible causes of misunderstandings of the process, and presents a review of the most common misconceptions that must be corrected before a functional understanding of natural selection and adaptive evolution can be achieved.
TL;DR: A new model for ammonia excretion in freshwater fish and its variable linkage to Na+ uptake and acid excretion is proposed, which is probably dependent on acid trapping in boundary layer water by H+ ions created by the catalysed or non-catalysed hydration of expired metabolic CO2.
Abstract: Ammonia excretion at the gills of fish has been studied for 80 years, but the mechanism(s) involved remain controversial. The relatively recent discovery of the ammonia-transporting function of the Rhesus (Rh) proteins, a family related to the Mep/Amt family of methyl ammonia and ammonia transporters in bacteria, yeast and plants, and the occurrence of these genes and glycosylated proteins in fish gills has opened a new paradigm. We provide background on the evolution and function of the Rh proteins, and review recent studies employing molecular physiology which demonstrate their important contribution to branchial ammonia efflux. Rhag occurs in red blood cells, whereas several isoforms of both Rhbg and Rhcg occur in many tissues. In the branchial epithelium, Rhcg appears to be localized in apical membranes and Rhbg in basolateral membranes. Their gene expression is upregulated during exposure to high environmental ammonia or internal ammonia infusion, and may be sensitive to synergistic stimulation by ammonia and cortisol. Rhcg in particular appears to be coupled to H(+) excretion and Na(+) uptake mechanisms. We propose a new model for ammonia excretion in freshwater fish and its variable linkage to Na(+) uptake and acid excretion. In this model, Rhag facilitates NH(3) flux out of the erythrocyte, Rhbg moves it across the basolateral membrane of the branchial ionocyte, and an apical "Na(+)/NH (+)(4) exchange complex" consisting of several membrane transporters (Rhcg, V-type H(+)-ATPase, Na(+)/H(+) exchanger NHE-2 and/or NHE-3, Na(+) channel) working together as a metabolon provides an acid trapping mechanism for apical excretion. Intracellular carbonic anhydrase (CA-2) and basolateral Na(+)/HCO (-)(3) cotransporter (NBC-1) and Na(+)/K(+)-ATPase play indirect roles. These mechanisms are normally superimposed on a substantial outward movement of NH(3) by simple diffusion, which is probably dependent on acid trapping in boundary layer water by H(+) ions created by the catalysed or non-catalysed hydration of expired metabolic CO(2). Profitable areas for future investigation of Rh proteins in fish are highlighted: their involvement in the mechanism of ammonia excretion across the gills in seawater fish, their possible importance in ammonia excretion across the skin, their potential dual role as CO(2) transporters, their responses to feeding, and their roles in early life stages prior to the full development of gills.
TL;DR: It is revealed that 11 psl genes, pslACDEFGHIJKL, are required for Psl production and surface attachment and the first structural analysis of the psl‐dependent polysaccharide, which consists of a repeating pentasaccharide containing d‐mannose, d‐glucose and l‐rhamnose.
Abstract: Exopolysaccharides contribute significantly to attachment and biofilm formation in the opportunisitc pathogen Pseudomonas aeruginosa. The Psl polysaccharide, which is synthesized by the polysaccharide synthesis locus (psl), is required for biofilm formation in non-mucoid strains that do not rely on alginate as the principal biofilm polysaccharide. In-frame deletion and complementation studies of individual psl genes revealed that 11 psl genes, pslACDEFGHIJKL, are required for Psl production and surface attachment. We also present the first structural analysis of the psl-dependent polysaccharide, which consists of a repeating pentasaccharide containing d-mannose, d-glucose and l-rhamnose: [See text]. In addition, we identified the sugar nucleotide precursors involved in Psl generation and demonstrated the requirement for GDP-d-mannose, UDP-d-glucose and dTDP-l-rhamnose in Psl production and surface attachment. Finally, genetic analyses revealed that wbpW restored Psl production in a pslB mutant and pslB promoted A-band LPS synthesis in a wbpW mutant, indicating functional redundancy and overlapping roles for these two enzymes. The structural and genetic data presented here provide a basis for further investigation of the Psl proteins and potential roles for Psl in the biology and pathogenesis of P. aeruginosa.
University of Pennsylvania1, Smithsonian Institution2, Instituto Nacional de Biodiversidad3, North Carolina State University4, California Department of Food and Agriculture5, Missouri Botanical Garden6, University of Guelph7, Natural History Museum8, University of Florida9, American Museum of Natural History10, Carnegie Museum of Natural History11, University of Illinois at Urbana–Champaign12, University of Kentucky13, United States Department of Agriculture14, University of Minnesota15
TL;DR: Adding DNA barcoding to the inventory of the caterpillars, their food plants and parasitoids in northwestern Costa Rica has substantially improved the quality and depth of the inventory, and greatly multiplied the number of situations requiring further taxonomic work for resolution.
Abstract: Inventory of the caterpillars, their food plants and parasitoids began in 1978 for today's Area de Conservacion Guanacaste (ACG), in northwestern Costa Rica This complex mosaic of 120 000 ha of conserved and regenerating dry, cloud and rain forest over 0–2000 m elevation contains at least 10 000 species of non-leaf-mining caterpillars used by more than 5000 species of parasitoids Several hundred thousand specimens of ACG-reared adult Lepidoptera and parasitoids have been intensively and extensively studied morphologically by many taxonomists, including most of the co-authors DNA barcoding — the use of a standardized short mitochondrial DNA sequence to identify specimens and flush out undisclosed species — was added to the taxonomic identification process in 2003 Barcoding has been found to be extremely accurate during the identification of about 100 000 specimens of about 3500 morphologically defined species of adult moths, butterflies, tachinid flies, and parasitoid wasps Less than 1% of the species have such similar barcodes that a molecularly based taxonomic identification is impossible No specimen with a full barcode was misidentified when its barcode was compared with the barcode library Also as expected from early trials, barcoding a series from all morphologically defined species, and correlating the morphological, ecological and barcode traits, has revealed many hundreds of overlooked presumptive species Many but not all of these cryptic species can now be distinguished by subtle morphological and/or ecological traits previously ascribed to ‘variation’ or thought to be insignificant for species-level recognition Adding DNA barcoding to the inventory has substantially improved the quality and depth of the inventory, and greatly multiplied the number of situations requiring further taxonomic work for resolution
TL;DR: A better understanding of the individual role for ALA, EPA and DHA is needed in order to make appropriate dietary recommendations regarding n-3 polyunsaturated fatty acid consumption, and potential mechanisms of action are reviewed.
Abstract: N-3 Polyunsaturated fatty acids have been shown to have potential beneficial effects for chronic diseases including cancer, insulin resistance and cardiovascular disease. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in particular have been studied extensively, whereas substantive evidence for a biological role for the precursor, alpha-linolenic acid (ALA), is lacking. It is not enough to assume that ALA exerts effects through conversion to EPA and DHA, as the process is highly inefficient in humans. Thus, clarification of ALA's involvement in health and disease is essential, as it is the principle n-3 polyunsaturated fatty acid consumed in the North American diet and intakes of EPA and DHA are typically very low. There is evidence suggesting that ALA, EPA and DHA have specific and potentially independent effects on chronic disease. Therefore, this review will assess our current understanding of the differential effects of ALA, EPA and DHA on cancer, insulin resistance, and cardiovascular disease. Potential mechanisms of action will also be reviewed. Overall, a better understanding of the individual role for ALA, EPA and DHA is needed in order to make appropriate dietary recommendations regarding n-3 polyunsaturated fatty acid consumption.
TL;DR: Comparison of sludge properties and cake layer structure from the two submerged anaerobic membrane bioreactors showed that the cake layer formed in the thermophilic SAnMBR contained higher levels of both organic and inorganic foulants, smaller particle sizes, and especially, a denser and more compact sludge cake structure.
TL;DR: In this paper, the putative Arabidopsis thaliana TREX-2 complex and its anchoring nucleoporin were identified and characterized, which is essential for mRNA export in eukaryotes.
Abstract: Nuclear pore complexes (NPCs) are vital to nuclear-cytoplasmic communication in eukaryotes. The yeast NPC-associated TREX-2 complex, also known as the Thp1-Sac3-Cdc31-Sus1 complex, is anchored on the NPC via the nucleoporin Nup1, and is essential for mRNA export. Here we report the identification and characterization of the putative Arabidopsis thaliana TREX-2 complex and its anchoring nucleoporin. Physical and functional evidence support the identification of the Arabidopsis orthologs of yeast Thp1 and Nup1. Of three Arabidopsis homologs of yeast Sac3, two are putative TREX-2 components, but, surprisingly, none are required for mRNA export as they are in yeast. Physical association of the two Cdc31 homologs, but not the Sus1 homolog, with the TREX-2 complex was observed. In addition to identification of these TREX-2 components, direct interactions of the Arabidopsis homolog of DSS1, which is an established proteasome component in yeast and animals, with both the TREX-2 complex and the proteasome were observed. This suggests the possibility of a link between the two complexes. Thus this work has identified the putative Arabidopsis TREX-2 complex and provides a foundation for future studies of nuclear export in Arabidopsis.
TL;DR: QMSim was designed to simulate large-scale genotyping data in multiple and complex livestock pedigrees and is efficient in terms of computing time and memory requirements.
Abstract: QMSim was designed to simulate large-scale genotyping data in multiple and complex livestock pedigrees. The simulation is basically carried out in two steps. In the first step, a historical population is simulated to establish mutation-drift equilibrium, and in the second step, recent population structures are generated, which can be very complex. A wide variety of genome architectures, ranging from infinitesimal model to single-locus model, can be simulated. The program is efficient in terms of computing time and memory requirements. Availability: Executable versions of QMSim for Windows and Linux are freely available at http://www.aps.uoguelph.ca/∼msargol/qmsim/. Contact: msargol@uoguelph.ca
TL;DR: Variability in colonization strategies evolved early in the diversification of AM fungi, and it is proposed that these strategies were influenced by functional interactions with host plants, resulting in an evolutionary stasis resembling trait conservatism.
Abstract: The diversity of functional and life-history traits of organisms depends on adaptation as well as the legacy of shared ancestry. Although the evolution of traits in macro-organisms is well studied, relatively little is known about character evolution in micro-organisms. Here, we surveyed an ancient and ecologically important group of microbial plant symbionts, the arbuscular mycorrhizal (AM) fungi, and tested hypotheses about the evolution of functional and life-history traits. Variation in the extent of root and soil colonization by AM fungi is constrained to a few nodes basal to the most diverse groups within the phylum, with relatively little variation associated with recent divergences. We found no evidence for a trade-off in biomass allocated to root versus soil colonization in three published glasshouse experiments; rather these traits were positively correlated. Partial support was observed for correlated evolution between fungal colonization strategies and functional benefits of the symbiosis to host plants. The evolution of increased soil colonization was positively correlated with total plant biomass and shoot phosphorus content. Although the effect of AM fungi on infection by root pathogens was phylogenetically conserved, there was no evidence for correlated evolution between the extent of AM fungal root colonization and pathogen infection. Variability in colonization strategies evolved early in the diversification of AM fungi, and we propose that these strategies were influenced by functional interactions with host plants, resulting in an evolutionary stasis resembling trait conservatism.
TL;DR: A polymerase chain reaction and sequence‐based technique is used to identify prey fragments in the guano of the generalist insectivore, the eastern red bat, and evaluate several hypotheses about prey selection and prey defences, providing an unprecedented level of detail for the study of predator–prey relationships in bats.
Abstract: One of the most difficult interactions to observe in nature is the relationship between a predator and its prey. When direct observations are impossible, we rely on morphological classification of prey remains, although this is particularly challenging among generalist predators whose faeces contain mixed and degraded prey fragments. In this investigation, we used a polymerase chain reaction and sequence-based technique to identify prey fragments in the guano of the generalist insectivore, the eastern red bat (Lasiurus borealis), and evaluate several hypotheses about prey selection and prey defences. The interaction between bats and insects is of significant evolutionary interest because of the adaptive nature of insect hearing against echolocation. However, measuring the successes of predator tactics or particular prey defences is limited because we cannot normally identify these digested prey fragments beyond order or family. Using a molecular approach, we recovered sequences from 89% of the fragments tested, and through comparison to a reference database of sequences, we were able to identify 127 different species of prey. Our results indicate that despite the robust jaws of L. borealis, most prey taxa were softer-bodied Lepidoptera. Surprisingly, more than 60% of the prey species were tympanate, with ears thought to afford protection against these echolocating bats. Moths of the family Arctiidae, which employ multiple defensive strategies, were not detected as a significant dietary component. Our results provide an unprecedented level of detail for the study of predator-prey relationships in bats and demonstrate the advantages which molecular tools can provide in investigations of complex ecological systems and food-web relationships.
TL;DR: Plant and fungal identity determines pathogen protection of plant roots by arbuscular mycorrhizas and this article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
Abstract: This is the peer reviewed version of the following article: BA Sikes, K Cottenie and JN Klironomos. (2009) Plant and fungal identity determines pathogen protection of plant roots by arbuscular mycorrhizas. Journal of Ecology 97: 1274-1280. http://dx.doi.org/10.1111/j.1365-2745.2009.01557.x, which has been published in final form at http://doi.org/10.1111/j.1365-2745.2009.01557.x This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
TL;DR: The data suggest that the critical threshold where greater body size increases dispersal limitation seems to come at the juncture between invertebrates and vertebrates rather than that between unicellular and multicellular organisms as has been previously suggested.
Abstract: Dispersal can limit the ranges of species and the diversity of communities. Despite its importance, little is known about its role in freshwater habitats and its relation to habitat type (lentic vs. lotic), especially for organisms with cryptic dispersal methods such as plankton. Poor dispersers are expected to show more clumped distributions or greater spatial autocorrelation (SA) in community composition than good dispersers. We examined patterns of SA across freshwater taxa with different dispersal modes (active vs. passive) and their association with habitat type (lake vs. stream) using 18 spatially explicit community composition data sets. We found significant relationships between SA and body size among taxa in lake habitats, but not in streams. However, the increase in SA with body size in lakes was driven entirely by fishes-organisms ranging in size from diatoms to macro-invertebrates showed equivalent levels of SA. These results support the idea that large organisms are less effective dispersers in aquatic environments, resulting in greater SA in community structure over broad scales. Streams may be effectively more connected than lakes as patterns of SA and body size were weaker in lotic habitats. Our data suggest that the critical threshold where greater body size increases dispersal limitation seems to come at the juncture between invertebrates and vertebrates rather than that between unicellular and multicellular organisms as has been previously suggested.
TL;DR: A full understanding of LPS biosynthesis in P. aeruginosa is almost within reach, and knowledge derived from detailed studies in the O5, O6 and O11 serotypes is applied to predict biosynthesis pathways of sugars in poorly-studied serotypes.
Abstract: Pseudomonas aeruginosa causes serious nosocomial infections, and an important virulence factor produced by this organism is lipopolysaccharide (LPS). This review summarizes knowledge about biosynthesis of all three structural domains of LPS - lipid A, core oligosaccharide, and O polysaccharides. In addition, based on similarities with other bacterial species, this review proposes new hypothetical pathways for unstudied steps in the biosynthesis of P. aeruginosa LPS. Lipid A biosynthesis is discussed in relation to Escherichia coli and Salmonella, and the biosyntheses of core sugar precursors and core oligosaccharide are summarised. Pseudomonas aeruginosa attaches a Common Polysaccharide Antigen and O-Specific Antigen polysaccharides to lipid A-core. Both forms of O polysaccharide are discussed with respect to their independent synthesis mechanisms. Recent advances in understanding O-polysaccharide biosynthesis since the last major review on this subject, published nearly a decade ago, are highlighted. Since P. aeruginosa O polysaccharides contain unusual sugars, sugar-nucleotide biosynthesis pathways are reviewed in detail. Knowledge derived from detailed studies in the O5, O6 and O11 serotypes is applied to predict biosynthesis pathways of sugars in poorly-studied serotypes, especially O1, O4, and O13/O14. Although further work is required, a full understanding of LPS biosynthesis in P. aeruginosa is almost within reach.
TL;DR: In this article, the authors compared emotional display rules of Canadian, US Americans, and Japanese across cultures regarding the specific emotion, the type of interaction partner, and gender, finding that Japanese display rules permit the expression of powerful (anger, contempt, and disgust) significantly less than those of the two North American samples.
Abstract: This study investigates emotional display rules for seven basic emotions. The main goal was to compare emotional display rules of Canadians, US Americans, and Japanese across as well as within cultures regarding the specific emotion, the type of interaction partner, and gender. A total of 835 university students participated in the study. The results indicate that Japanese display rules permit the expression of powerful (anger, contempt, and disgust) significantly less than those of the two North American samples. Japanese also think that they should express positive emotions (happiness, surprise) significantly less than the Canadian sample. Furthermore, Japanese varied the display rules for different interaction partners more than the two North American samples did only for powerful emotions. Gender differences were similar across all three cultural groups. Men expressed powerful emotions more than women and women expressed powerless emotions (sadness, fear) and happiness more than men. Depending on the type of emotion and interaction partner some shared display rules occurred across culture and gender. The implications of these findings are discussed in relation to cultural dimensions and other cultural characteristics.
TL;DR: This review will show the tremendous versatility and importance of scFv fragments as they provide the basic antigen binding unit for a multitude of engineered Abs for use as human therapeutics and diagnostics.