WorldWideScience

Sample records for understanding host-pathogen interactions

  1. Gnotobiotic mouse model's contribution to understanding host-pathogen interactions

    Czech Academy of Sciences Publication Activity Database

    Kubelková, K.; Benuchová, M.; Kozáková, Hana; Šinkora, Marek; Kročová, Z.; Pejchal, J.; Macela, A.

    2016-01-01

    Roč. 73, č. 20 (2016), s. 3961-3969 ISSN 1420-682X R&D Projects: GA ČR GA15-02274S Institutional support: RVO:61388971 Keywords : Germ- free model * Gnotobiology * Host-pathogen interaction Subject RIV: EC - Immunology Impact factor: 5.788, year: 2016

  2. Genes, communities & invasive species: understanding the ecological and evolutionary dynamics of host-pathogen interactions.

    Science.gov (United States)

    Burdon, J J; Thrall, P H; Ericson, L

    2013-08-01

    Reciprocal interactions between hosts and pathogens drive ecological, epidemiological and co-evolutionary trajectories, resulting in complex patterns of diversity at population, species and community levels. Recent results confirm the importance of negative frequency-dependent rather than 'arms-race' processes in the evolution of individual host-pathogen associations. At the community level, complex relationships between species abundance and diversity dampen or alter pathogen impacts. Invasive pathogens challenge these controls reflecting the earliest stages of evolutionary associations (akin to arms-race) where disease effects may be so great that they overwhelm the host's and community's ability to respond. Viewing these different stabilization/destabilization phases as a continuum provides a valuable perspective to assessment of the role of genetics and ecology in the dynamics of both natural and invasive host-pathogen associations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Serpin functions in host-pathogen interactions

    Directory of Open Access Journals (Sweden)

    Jialing Bao

    2018-04-01

    Full Text Available Serpins are a broadly distributed superfamily of protease inhibitors that are present in all kingdoms of life. The acronym, serpin, is derived from their function as potent serine proteases inhibitors. Early studies of serpins focused on their functions in haemostasis since modulating serine proteases activities are essential for coagulation. Additional research has revealed that serpins function in infection and inflammation, by modulating serine and cysteine proteases activities. The aim of this review is to summarize the accumulating findings and current understanding of the functions of serpins in host-pathogen interactions, serving as host defense proteins as well as pathogenic factors. We also discuss the potential crosstalk between host and pathogen serpins. We anticipate that future research will elucidate the therapeutic value of this novel target.

  4. Host-pathogen interactions in typhoid fever

    NARCIS (Netherlands)

    de Jong, H.K.

    2015-01-01

    This thesis focuses on host-pathogen interactions in Salmonella Typhi and Burkholderia pseudomallei infections and explores the interplay between these bacteria and the innate immune system. Typhoid fever is one of the most common causes of bacterial infection in low-income countries. With adequate

  5. Deconstructing host-pathogen interactions in Drosophila

    Directory of Open Access Journals (Sweden)

    Ethan Bier

    2012-01-01

    Full Text Available Many of the cellular mechanisms underlying host responses to pathogens have been well conserved during evolution. As a result, Drosophila can be used to deconstruct many of the key events in host-pathogen interactions by using a wealth of well-developed molecular and genetic tools. In this review, we aim to emphasize the great leverage provided by the suite of genomic and classical genetic approaches available in flies for decoding details of host-pathogen interactions; these findings can then be applied to studies in higher organisms. We first briefly summarize the general strategies by which Drosophila resists and responds to pathogens. We then focus on how recently developed genome-wide RNA interference (RNAi screens conducted in cells and flies, combined with classical genetic methods, have provided molecular insight into host-pathogen interactions, covering examples of bacteria, fungi and viruses. Finally, we discuss novel strategies for how flies can be used as a tool to examine how specific isolated virulence factors act on an intact host.

  6. Host-pathogen interactions during apoptosis

    Indian Academy of Sciences (India)

    Unknown

    349. Keywords. Antioxidant; baculovirus; host-pathogen; eIF2α-kinase; P35; PKR .... conferring a selective advantage to the virus, the capacity to prevent apoptosis is ..... totic extracts were found to cleave purified PKR in vitro. These findings ...

  7. RNA-seq in kinetoplastids: A powerful tool for the understanding of the biology and host-pathogen interactions.

    Science.gov (United States)

    Patino, Luz Helena; Ramírez, Juan David

    2017-04-01

    The kinetoplastids include a large number of parasites responsible for serious diseases in humans and animals (Leishmania and Trypanosoma brucei) considered endemic in several regions of the world. These parasites are characterized by digenetic life cycles that undergo morphological and genetic changes that allow them to adapt to different microenvironments on their vertebrates and invertebrates hosts. Recent advances in ´omics´ technology, specifically transcriptomics have allowed to reveal aspects associated with such molecular changes. So far, different techniques have been used to evaluate the gene expression profile during the various stages of the life cycle of these parasites and during the host-parasite interactions. However, some of them have serious drawbacks that limit the precise study and full understanding of their transcriptomes. Therefore, recently has been implemented the latest technology (RNA-seq), which overcomes the drawbacks of traditional methods. In this review, studies that so far have used RNA-seq are presented and allowed to expand our knowledge regarding the biology of these parasites and their interactions with their hosts. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Exploring NAD+ metabolism in host-pathogen interactions.

    Science.gov (United States)

    Mesquita, Inês; Varela, Patrícia; Belinha, Ana; Gaifem, Joana; Laforge, Mireille; Vergnes, Baptiste; Estaquier, Jérôme; Silvestre, Ricardo

    2016-03-01

    Nicotinamide adenine dinucleotide (NAD(+)) is a vital molecule found in all living cells. NAD(+) intracellular levels are dictated by its synthesis, using the de novo and/or salvage pathway, and through its catabolic use as co-enzyme or co-substrate. The regulation of NAD(+) metabolism has proven to be an adequate drug target for several diseases, including cancer, neurodegenerative or inflammatory diseases. Increasing interest has been given to NAD(+) metabolism during innate and adaptive immune responses suggesting that its modulation could also be relevant during host-pathogen interactions. While the maintenance of NAD(+) homeostatic levels assures an adequate environment for host cell survival and proliferation, fluctuations in NAD(+) or biosynthetic precursors bioavailability have been described during host-pathogen interactions, which will interfere with pathogen persistence or clearance. Here, we review the double-edged sword of NAD(+) metabolism during host-pathogen interactions emphasizing its potential for treatment of infectious diseases.

  9. Host-pathogen interactions: A cholera surveillance system

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Aaron T.

    2016-02-22

    Bacterial pathogen-secreted proteases may play a key role in inhibiting a potentially widespread host-pathogen interaction. Activity-based protein profiling enabled the identification of a major Vibrio cholerae serine protease that limits the ability of a host-derived intestinal lectin to bind to the bacterial pathogen in vivo.

  10. Protein prenylation: a new mode of host-pathogen interaction.

    Science.gov (United States)

    Amaya, Moushimi; Baranova, Ancha; van Hoek, Monique L

    2011-12-09

    Post translational modifications are required for proteins to be fully functional. The three step process, prenylation, leads to farnesylation or geranylgeranylation, which increase the hydrophobicity of the prenylated protein for efficient anchoring into plasma membranes and/or organellar membranes. Prenylated proteins function in a number of signaling and regulatory pathways that are responsible for basic cell operations. Well characterized prenylated proteins include Ras, Rac and Rho. Recently, pathogenic prokaryotic proteins, such as SifA and AnkB, have been shown to be prenylated by eukaryotic host cell machinery, but their functions remain elusive. The identification of other bacterial proteins undergoing this type of host-directed post-translational modification shows promise in elucidating host-pathogen interactions to develop new therapeutics. This review incorporates new advances in the study of protein prenylation into a broader aspect of biology with a focus on host-pathogen interaction. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Protein Disulfide Isomerase and Host-Pathogen Interaction

    Directory of Open Access Journals (Sweden)

    Beatriz S. Stolf

    2011-01-01

    Full Text Available Reactive oxygen species (ROS production by immunological cells is known to cause damage to pathogens. Increasing evidence accumulated in the last decade has shown, however, that ROS (and redox signals functionally regulate different cellular pathways in the host-pathogen interaction. These especially affect (i pathogen entry through protein redox switches and redox modification (i.e., intra- and interdisulfide and cysteine oxidation and (ii phagocytic ROS production via Nox family NADPH oxidase enzyme and the control of phagolysosome function with key implications for antigen processing. The protein disulfide isomerase (PDI family of redox chaperones is closely involved in both processes and is also implicated in protein unfolding and trafficking across the endoplasmic reticulum (ER and towards the cytosol, a thiol-based redox locus for antigen processing. Here, we summarise examples of the cellular association of host PDI with different pathogens and explore the possible roles of pathogen PDIs in infection. A better understanding of these complex regulatory steps will provide insightful information on the redox role and coevolutional biological process, and assist the development of more specific therapeutic strategies in pathogen-mediated infections.

  12. Entomopathogenic Fungi: New Insights into Host-Pathogen Interactions.

    Science.gov (United States)

    Butt, T M; Coates, C J; Dubovskiy, I M; Ratcliffe, N A

    2016-01-01

    Although many insects successfully live in dangerous environments exposed to diverse communities of microbes, they are often exploited and killed by specialist pathogens. Studies of host-pathogen interactions (HPI) provide valuable insights into the dynamics of the highly aggressive coevolutionary arms race between entomopathogenic fungi (EPF) and their arthropod hosts. The host defenses are designed to exclude the pathogen or mitigate the damage inflicted while the pathogen responds with immune evasion and utilization of host resources. EPF neutralize their immediate surroundings on the insect integument and benefit from the physiochemical properties of the cuticle and its compounds that exclude competing microbes. EPF also exhibit adaptations aimed at minimizing trauma that can be deleterious to both host and pathogen (eg, melanization of hemolymph), form narrow penetration pegs that alleviate host dehydration and produce blastospores that lack immunogenic sugars/enzymes but facilitate rapid assimilation of hemolymph nutrients. In response, insects deploy an extensive armory of hemocytes and macromolecules, such as lectins and phenoloxidase, that repel, immobilize, and kill EPF. New evidence suggests that immune bioactives work synergistically (eg, lysozyme with antimicrobial peptides) to combat infections. Some proteins, including transferrin and apolipophorin III, also demonstrate multifunctional properties, participating in metabolism, homeostasis, and pathogen recognition. This review discusses the molecular intricacies of these HPI, highlighting the interplay between immunity, stress management, and metabolism. Increased knowledge in this area could enhance the efficacy of EPF, ensuring their future in integrated pest management programs. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Host-pathogen interactions between the human innate immune system and Candida albicans—understanding and modeling defense and evasion strategies

    Science.gov (United States)

    Dühring, Sybille; Germerodt, Sebastian; Skerka, Christine; Zipfel, Peter F.; Dandekar, Thomas; Schuster, Stefan

    2015-01-01

    The diploid, polymorphic yeast Candida albicans is one of the most important human pathogenic fungi. C. albicans can grow, proliferate and coexist as a commensal on or within the human host for a long time. However, alterations in the host environment can render C. albicans virulent. In this review, we describe the immunological cross-talk between C. albicans and the human innate immune system. We give an overview in form of pairs of human defense strategies including immunological mechanisms as well as general stressors such as nutrient limitation, pH, fever etc. and the corresponding fungal response and evasion mechanisms. Furthermore, Computational Systems Biology approaches to model and investigate these complex interactions are highlighted with a special focus on game-theoretical methods and agent-based models. An outlook on interesting questions to be tackled by Systems Biology regarding entangled defense and evasion mechanisms is given. PMID:26175718

  14. Metabolic investigation of host/pathogen interaction using MS2-infected Escherichia coli

    Directory of Open Access Journals (Sweden)

    Jain Rishi

    2009-12-01

    Full Text Available Abstract Background RNA viruses are responsible for a variety of illnesses among people, including but not limited to the common cold, the flu, HIV, and ebola. Developing new drugs and new strategies for treating diseases caused by these viruses can be an expensive and time-consuming process. Mathematical modeling may be used to elucidate host-pathogen interactions and highlight potential targets for drug development, as well providing the basis for optimizing patient treatment strategies. The purpose of this work was to determine whether a genome-scale modeling approach could be used to understand how metabolism is impacted by the host-pathogen interaction during a viral infection. Escherichia coli/MS2 was used as the host-pathogen model system as MS2 is easy to work with, harmless to humans, but shares many features with eukaryotic viruses. In addition, the genome-scale metabolic model of E. coli is the most comprehensive model at this time. Results Employing a metabolic modeling strategy known as "flux balance analysis" coupled with experimental studies, we were able to predict how viral infection would alter bacterial metabolism. Based on our simulations, we predicted that cell growth and biosynthesis of the cell wall would be halted. Furthermore, we predicted a substantial increase in metabolic activity of the pentose phosphate pathway as a means to enhance viral biosynthesis, while a break down in the citric acid cycle was predicted. Also, no changes were predicted in the glycolytic pathway. Conclusions Through our approach, we have developed a technique of modeling virus-infected host metabolism and have investigated the metabolic effects of viral infection. These studies may provide insight into how to design better drugs. They also illustrate the potential of extending such metabolic analysis to higher order organisms, including humans.

  15. Recent insights into host-pathogen interaction in white spot syndrome virus infected penaeid shrimp.

    Science.gov (United States)

    Shekhar, M S; Ponniah, A G

    2015-07-01

    Viral disease outbreaks are a major concern impeding the development of the shrimp aquaculture industry. The viral disease due to white spot syndrome virus (WSSV) observed in early 1990s still continues unabated affecting the shrimp farms and cause huge economic loss to the shrimp aquaculture industry. In the absence of effective therapeutics to control WSSV, it is important to understand viral pathogenesis and shrimp response to WSSV at the molecular level. Identification and molecular characterization of WSSV proteins and receptors may facilitate in designing and development of novel therapeutics and antiviral drugs that may inhibit viral replication. Investigations into host-pathogen interactions might give new insights to viral infectivity, tissue tropism and defence mechanism elicited in response to WSSV infection. However, due to the limited information on WSSV gene function and host immune response, the signalling pathways which are associated in shrimp pathogen interaction have also not been elucidated completely. In the present review, the focus is on those shrimp proteins and receptors that are potentially involved in virus infection or in the defence mechanism against WSSV. In addition, the major signalling pathways involved in the innate immune response and the role of apoptosis in host-pathogen interaction is discussed. © 2014 John Wiley & Sons Ltd.

  16. MODELING HOST-PATHOGEN INTERACTIONS: COMPUTATIONAL BIOLOGY AND BIOINFORMATICS FOR INFECTIOUS DISEASE RESEARCH (Session introduction)

    Energy Technology Data Exchange (ETDEWEB)

    McDermott, Jason E.; Braun, Pascal; Bonneau, Richard A.; Hyduke, Daniel R.

    2011-12-01

    Pathogenic infections are a major cause of both human disease and loss of crop yields and animal stocks and thus cause immense damage to the worldwide economy. The significance of infectious diseases is expected to increase in an ever more connected warming world, in which new viral, bacterial and fungal pathogens can find novel hosts and ecologic niches. At the same time, the complex and sophisticated mechanisms by which diverse pathogenic agents evade defense mechanisms and subvert their hosts networks to suit their lifestyle needs is still very incompletely understood especially from a systems perspective [1]. Thus, understanding host-pathogen interactions is both an important and a scientifically fascinating topic. Recently, technology has offered the opportunity to investigate host-pathogen interactions on a level of detail and scope that offers immense computational and analytical possibilities. Genome sequencing was pioneered on some of these pathogens, and the number of strains and variants of pathogens sequenced to date vastly outnumbers the number of host genomes available. At the same time, for both plant and human hosts more and more data on population level genomic variation becomes available and offers a rich field for analysis into the genetic interactions between host and pathogen.

  17. Organoid culture systems to study host-pathogen interactions

    NARCIS (Netherlands)

    Dutta, Devanjali; Clevers, Hans

    2017-01-01

    Recent advances in host-microbe interaction studies in organoid cultures have shown great promise and have laid the foundation for much more refined future studies using these systems. Modeling of Zika virus (ZIKV) infection in cerebral organoids have helped us understand its association with

  18. Limitations of a metabolic network-based reverse ecology method for inferring host-pathogen interactions.

    Science.gov (United States)

    Takemoto, Kazuhiro; Aie, Kazuki

    2017-05-25

    Host-pathogen interactions are important in a wide range of research fields. Given the importance of metabolic crosstalk between hosts and pathogens, a metabolic network-based reverse ecology method was proposed to infer these interactions. However, the validity of this method remains unclear because of the various explanations presented and the influence of potentially confounding factors that have thus far been neglected. We re-evaluated the importance of the reverse ecology method for evaluating host-pathogen interactions while statistically controlling for confounding effects using oxygen requirement, genome, metabolic network, and phylogeny data. Our data analyses showed that host-pathogen interactions were more strongly influenced by genome size, primary network parameters (e.g., number of edges), oxygen requirement, and phylogeny than the reserve ecology-based measures. These results indicate the limitations of the reverse ecology method; however, they do not discount the importance of adopting reverse ecology approaches altogether. Rather, we highlight the need for developing more suitable methods for inferring host-pathogen interactions and conducting more careful examinations of the relationships between metabolic networks and host-pathogen interactions.

  19. Mechanisms of Disease: Host-Pathogen Interactions between Burkholderia Species and Lung Epithelial Cells

    Science.gov (United States)

    David, Jonathan; Bell, Rachel E.; Clark, Graeme C.

    2015-01-01

    Members of the Burkholderia species can cause a range of severe, often fatal, respiratory diseases. A variety of in vitro models of infection have been developed in an attempt to elucidate the mechanism by which Burkholderia spp. gain entry to and interact with the body. The majority of studies have tended to focus on the interaction of bacteria with phagocytic cells with a paucity of information available with regard to the lung epithelium. However, the lung epithelium is becoming more widely recognized as an important player in innate immunity and the early response to infections. Here we review the complex relationship between Burkholderia species and epithelial cells with an emphasis on the most pathogenic species, Burkholderia pseudomallei and Burkholderia mallei. The current gaps in knowledge in our understanding are highlighted along with the epithelial host-pathogen interactions that offer potential opportunities for therapeutic intervention. PMID:26636042

  20. Protozoa lectins and their role in host-pathogen interactions.

    Science.gov (United States)

    Singh, Ram Sarup; Walia, Amandeep Kaur; Kanwar, Jagat Rakesh

    2016-01-01

    Lectins are proteins/glycoproteins of non-immune origin that agglutinate red blood cells, lymphocytes, fibroblasts, etc., and bind reversibly to carbohydrates present on the apposing cells. They have at least two carbohydrate binding sites and their binding can be inhibited by one or more carbohydrates. Owing to carbohydrate binding specificity of lectins, they mediate cell-cell interactions and play role in protozoan adhesion and host cell cytotoxicity, thus are central to the pathogenic property of the parasite. Several parasitic protozoa possess lectins which mediate parasite adherence to host cells based on their carbohydrate specificities. These interactions could be exploited for development of novel therapeutics, targeting the adherence and thus helpful in eradicating wide spread of protozoan diseases. The current review highlights the present state knowledge with regard to protozoal lectins with an emphasis on their haemagglutination activity, carbohydrate specificity, characteristics and also their role in pathogenesis notably as adhesion molecules, thereby aiding the pathogen in disease establishment. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Epigenetics of host-pathogen interactions: the road ahead and the road behind.

    Directory of Open Access Journals (Sweden)

    Elena Gómez-Díaz

    Full Text Available A growing body of evidence points towards epigenetic mechanisms being responsible for a wide range of biological phenomena, from the plasticity of plant growth and development to the nutritional control of caste determination in honeybees and the etiology of human disease (e.g., cancer. With the (partial elucidation of the molecular basis of epigenetic variation and the heritability of certain of these changes, the field of evolutionary epigenetics is flourishing. Despite this, the role of epigenetics in shaping host-pathogen interactions has received comparatively little attention. Yet there is plenty of evidence supporting the implication of epigenetic mechanisms in the modulation of the biological interaction between hosts and pathogens. The phenotypic plasticity of many key parasite life-history traits appears to be under epigenetic control. Moreover, pathogen-induced effects in host phenotype may have transgenerational consequences, and the bases of these changes and their heritability probably have an epigenetic component. The significance of epigenetic modifications may, however, go beyond providing a mechanistic basis for host and pathogen plasticity. Epigenetic epidemiology has recently emerged as a promising area for future research on infectious diseases. In addition, the incorporation of epigenetic inheritance and epigenetic plasticity mechanisms to evolutionary models and empirical studies of host-pathogen interactions will provide new insights into the evolution and coevolution of these associations. Here, we review the evidence available for the role epigenetics on host-pathogen interactions, and the utility and versatility of the epigenetic technologies available that can be cross-applied to host-pathogen studies. We conclude with recommendations and directions for future research on the burgeoning field of epigenetics as applied to host-pathogen interactions.

  2. Lawrence Livermore National Laboratory Workshop Characterization of Pathogenicity, Virulence and Host-Pathogen Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, A

    2006-08-30

    The threats of bio-terrorism and newly emerging infectious diseases pose serious challenges to the national security infrastructure. Rapid detection and diagnosis of infectious disease in human populations, as well as characterizing pathogen biology, are critical for reducing the morbidity and mortality associated with such threats. One of the key challenges in managing an infectious disease outbreak, whether through natural causes or acts of overt terrorism, is detection early enough to initiate effective countermeasures. Much recent attention has been directed towards the utility of biomarkers or molecular signatures that result from the interaction of the pathogen with the host for improving our ability to diagnose and mitigate the impact of a developing infection during the time window when effective countermeasures can be instituted. Host responses may provide early signals in blood even from localized infections. Multiple innate and adaptive immune molecules, in combination with other biochemical markers, may provide disease-specific information and new targets for countermeasures. The presence of pathogen specific markers and an understanding of the molecular capabilities and adaptations of the pathogen when it interacts with its host may likewise assist in early detection and provide opportunities for targeting countermeasures. An important question that needs to be addressed is whether these molecular-based approaches will prove useful for early diagnosis, complement current methods of direct agent detection, and aid development and use of countermeasures. Lawrence Livermore National Laboratory (LLNL) will host a workshop to explore the utility of host- and pathogen-based molecular diagnostics, prioritize key research issues, and determine the critical steps needed to transition host-pathogen research to tools that can be applied towards a more effective national bio-defense strategy. The workshop will bring together leading researchers/scientists in the

  3. Mining Host-Pathogen Protein Interactions to Characterize Burkholderia mallei Infectivity Mechanisms

    Science.gov (United States)

    2015-03-04

    the cytoskeleton, in lysosomes , and in the nuclear lumen. These results were consistent with the experimentally observed pathogen interference with...RESEARCH ARTICLE Mining Host- Pathogen Protein Interactions to Characterize Burkholderia mallei Infectivity Mechanisms Vesna Memišević1, Nela...Bacteriology Division, U.S. Army Medical Research Institute of Infectious Diseases , Fort Detrick, Maryland, United States of America * jaques.reifman.civ

  4. Investigating host-pathogen behavior and their interaction using genome-scale metabolic network models.

    Science.gov (United States)

    Sadhukhan, Priyanka P; Raghunathan, Anu

    2014-01-01

    Genome Scale Metabolic Modeling methods represent one way to compute whole cell function starting from the genome sequence of an organism and contribute towards understanding and predicting the genotype-phenotype relationship. About 80 models spanning all the kingdoms of life from archaea to eukaryotes have been built till date and used to interrogate cell phenotype under varying conditions. These models have been used to not only understand the flux distribution in evolutionary conserved pathways like glycolysis and the Krebs cycle but also in applications ranging from value added product formation in Escherichia coli to predicting inborn errors of Homo sapiens metabolism. This chapter describes a protocol that delineates the process of genome scale metabolic modeling for analysing host-pathogen behavior and interaction using flux balance analysis (FBA). The steps discussed in the process include (1) reconstruction of a metabolic network from the genome sequence, (2) its representation in a precise mathematical framework, (3) its translation to a model, and (4) the analysis using linear algebra and optimization. The methods for biological interpretations of computed cell phenotypes in the context of individual host and pathogen models and their integration are also discussed.

  5. DAF as a therapeutic target for steroid hormones: implications for host-pathogen interactions.

    Science.gov (United States)

    Nowicki, Bogdan; Nowicki, Stella

    2013-01-01

    In this chapter, we present a concise historic prospective and a summary of accumulated knowledge on steroid hormones, DAF expression, and therapeutic implication of steroid hormone treatment on multiple pathologies, including infection and the host-pathogen interactions. DAF/CD55 plays multiple physiologic functions including tissue protection from the cytotoxic complement injury, an anti-inflammatory function due to its anti-adherence properties which enhance transmigration of monocytes and macrophages and reduce tissue injury. DAF physiologic functions are essential in many organ systems including pregnancy for protection of the semiallogeneic fetus or for preventing uncontrolled infiltration by white cells in their pro- and/or anti-inflammatory functions. DAF expression appears to have multiple regulatory tissue-specific and/or menstrual cycle-specific mechanisms, which involve complex signaling mechanisms. Regulation of DAF expression may involve a direct or an indirect effect of at least the estrogen, progesterone, and corticosteroid regulatory pathways. DAF is exploited in multiple pathologic conditions by pathogens and viruses in chronic tissue infection processes. The binding of Escherichia coli bearing Dr adhesins to the DAF/CD55 receptor is DAF density dependent and triggers internalization of E. coli via an endocytic pathway involving CD55, lipid rafts, and microtubules. Dr+ E. coli or Dr antigen may persist in vivo in the interstitium for several months. Further understanding of such processes should be instrumental in designing therapeutic strategies for multiple conditions involving DAF's protective or pathologic functions and tailoring host expression of DAF.

  6. Prediction of host - pathogen protein interactions between Mycobacterium tuberculosis and Homo sapiens using sequence motifs.

    Science.gov (United States)

    Huo, Tong; Liu, Wei; Guo, Yu; Yang, Cheng; Lin, Jianping; Rao, Zihe

    2015-03-26

    Emergence of multiple drug resistant strains of M. tuberculosis (MDR-TB) threatens to derail global efforts aimed at reigning in the pathogen. Co-infections of M. tuberculosis with HIV are difficult to treat. To counter these new challenges, it is essential to study the interactions between M. tuberculosis and the host to learn how these bacteria cause disease. We report a systematic flow to predict the host pathogen interactions (HPIs) between M. tuberculosis and Homo sapiens based on sequence motifs. First, protein sequences were used as initial input for identifying the HPIs by 'interolog' method. HPIs were further filtered by prediction of domain-domain interactions (DDIs). Functional annotations of protein and publicly available experimental results were applied to filter the remaining HPIs. Using such a strategy, 118 pairs of HPIs were identified, which involve 43 proteins from M. tuberculosis and 48 proteins from Homo sapiens. A biological interaction network between M. tuberculosis and Homo sapiens was then constructed using the predicted inter- and intra-species interactions based on the 118 pairs of HPIs. Finally, a web accessible database named PATH (Protein interactions of M. tuberculosis and Human) was constructed to store these predicted interactions and proteins. This interaction network will facilitate the research on host-pathogen protein-protein interactions, and may throw light on how M. tuberculosis interacts with its host.

  7. Use of high-throughput mass spectrometry to elucidate host-pathogen interactions in Salmonella

    Energy Technology Data Exchange (ETDEWEB)

    Rodland, Karin D.; Adkins, Joshua N.; Ansong, Charles; Chowdhury, Saiful M.; Manes, Nathan P.; Shi, Liang; Yoon, Hyunjin; Smith, Richard D.; Heffron, Fred

    2008-12-01

    New improvements to mass spectrometry include increased sensitivity, improvements in analyzing the collected data, and most important, from the standpoint of this review, a much higher throughput allowing analysis of many samples in a single day. This short review describes how host-pathogen interactions can be dissected by mass spectrometry using Salmonella as a model system. The approach allowed direct identification of the majority of annotate Salmonella proteins, how expression changed under various in vitro growth conditions, and how this relates to virulence and expression within host cell cells. One of the most significant findings is that a very high percentage of the all annotated genes (>20%) are regulated post-transcriptionally. In addition, new and unexpected interactions have been identified for several Salmonella virulence regulators that involve protein-protein interactions suggesting additional functions of the regulator in coordinating virulence expression. Overall high throughput mass spectrometer provides a new view of pathogen-host interaction emphasizing the protein products and defining how protein interactions determine the outcome of infection.

  8. Use of high-throughput mass spectrometry to elucidate host pathogen interactions in Salmonella

    Energy Technology Data Exchange (ETDEWEB)

    Rodland, Karin D.; Adkins, Joshua N.; Ansong, Charles; Chowdhury, Saiful M.; Manes, Nathan P.; Shi, Liang; Yoon, Hyunjin; Smith, Richard D.; Heffron, Fred

    2008-12-01

    Capabilities in mass spectrometry are evolving rapidly, with recent improvements in sensitivity, data analysis, and most important, from the standpoint of this review, much higher throughput allowing analysis of many samples in a single day. This short review describes how these improvements in mass spectrometry can be used to dissect host-pathogen interactions using Salmonella as a model system. This approach enabled direct identification of the majority of annotated Salmonella proteins, quantitation of expression changes under various in vitro growth conditions, and new insights into virulence and expression of Salmonella proteins within host cell cells. One of the most significant findings is that a very high percentage of the all annotated genes (>20%) in Salmonella are regulated post-transcriptionally. In addition, new and unexpected interactions have been identified for several Salmonella virulence regulators that involve protein-protein interactions, suggesting additional functions of these regulators in coordinating virulence expression. Overall high throughput mass spectrometry provides a new view of pathogen-host interactions emphasizing the protein products and defining how protein interactions determine the outcome of infection.

  9. Ocean acidification and host-pathogen interactions: blue mussels, Mytilus edulis, encountering Vibrio tubiashii.

    Science.gov (United States)

    Asplund, Maria E; Baden, Susanne P; Russ, Sarah; Ellis, Robert P; Gong, Ningping; Hernroth, Bodil E

    2014-04-01

    Ocean acidification (OA) can shift the ecological balance between interacting organisms. In this study, we have used a model system to illustrate the interaction between a calcifying host organism, the blue mussel Mytilus edulis and a common bivalve bacterial pathogen, Vibrio tubiashii, with organisms being exposed to a level of acidification projected to occur by the end of the 21st century. OA exposures of the mussels were carried out in relative long-term (4 months) and short-term (4 days) experiments. We found no effect of OA on the culturability of V. tubiashii, in broth or in seawater. OA inhibited mussel shell growth and impaired crystalline shell structures but did not appear to affect mussel immune parameters (i.e haemocyte counts and phagocytotic capacity). Despite no evident impact on host immunity or growth and virulence of the pathogen, V. tubiashii was clearly more successful in infecting mussels exposed to long-term OA compared to those maintained under ambient conditions. Moreover, OA exposed V. tubiashii increased their viability when exposed to haemocytes of OA-treated mussel. Our findings suggest that even though host organisms may have the capacity to cope with periods of OA, these conditions may alter the outcome of host-pathogen interactions, favouring the success of the latter. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  10. In vivo Host-Pathogen Interaction as Revealed by Global Proteomic Profiling of Zebrafish Larvae

    Directory of Open Access Journals (Sweden)

    Francisco Díaz-Pascual

    2017-07-01

    Full Text Available The outcome of a host-pathogen interaction is determined by the conditions of the host, the pathogen, and the environment. Although numerous proteomic studies of in vitro-grown microbial pathogens have been performed, in vivo proteomic approaches are still rare. In addition, increasing evidence supports that in vitro studies inadequately reflect in vivo conditions. Choosing the proper host is essential to detect the expression of proteins from the pathogen in vivo. Numerous studies have demonstrated the suitability of zebrafish (Danio rerio embryos as a model to in vivo studies of Pseudomonas aeruginosa infection. In most zebrafish-pathogen studies, infection is achieved by microinjection of bacteria into the larvae. However, few reports using static immersion of bacterial pathogens have been published. In this study we infected 3 days post-fertilization (DPF zebrafish larvae with P. aeruginosa PAO1 by immersion and injection and tracked the in vivo immune response by the zebrafish. Additionally, by using non-isotopic (Q-exactive metaproteomics we simultaneously evaluated the proteomic response of the pathogen (P. aeruginosa PAO1 and the host (zebrafish. We found some zebrafish metabolic pathways, such as hypoxia response via HIF activation pathway, were exclusively enriched in the larvae exposed by static immersion. In contrast, we found that inflammation mediated by chemokine and cytokine signaling pathways was exclusively enriched in the larvae exposed by injection, while the integrin signaling pathway and angiogenesis were solely enriched in the larvae exposed by immersion. We also found important virulence factors from P. aeruginosa that were enriched only after exposure by injection, such as the Type-III secretion system and flagella-associated proteins. On the other hand, P. aeruginosa proteins involved in processes like biofilm formation, and cellular responses to antibiotic and starvation were enriched exclusively after exposure by

  11. Lipids in host-pathogen interactions: pathogens exploit the complexity of the host cell lipidome.

    Science.gov (United States)

    van der Meer-Janssen, Ynske P M; van Galen, Josse; Batenburg, Joseph J; Helms, J Bernd

    2010-01-01

    Lipids were long believed to have a structural role in biomembranes and a role in energy storage utilizing cellular lipid droplets and plasma lipoproteins. Research over the last decades has identified an additional role of lipids in cellular signaling, membrane microdomain organization and dynamics, and membrane trafficking. These properties make lipids an attractive target for pathogens to modulate host cell processes in order to allow their survival and replication. In this review we will summarize the often ingenious strategies of pathogens to modify the lipid homeostasis of host cells, allowing them to divert cellular processes. To this end pathogens take full advantage of the complexity of the lipidome. The examples are categorized in generalized and emerging principles describing the involvement of lipids in host-pathogen interactions. Several pathogens are described that simultaneously induce multiple changes in the host cell signaling and trafficking mechanisms. Elucidation of these pathogen-induced changes may have important implications for drug development. The emergence of high-throughput lipidomic techniques will allow the description of changes of the host cell lipidome at the level of individual molecular lipid species and the identification of lipid biomarkers.

  12. Human mini-guts: new insights into intestinal physiology and host-pathogen interactions.

    Science.gov (United States)

    In, Julie G; Foulke-Abel, Jennifer; Estes, Mary K; Zachos, Nicholas C; Kovbasnjuk, Olga; Donowitz, Mark

    2016-11-01

    The development of indefinitely propagating human 'mini-guts' has led to a rapid advance in gastrointestinal research related to transport physiology, developmental biology, pharmacology, and pathophysiology. These mini-guts, also called enteroids or colonoids, are derived from LGR5 + intestinal stem cells isolated from the small intestine or colon. Addition of WNT3A and other growth factors promotes stemness and results in viable, physiologically functional human intestinal or colonic cultures that develop a crypt-villus axis and can be differentiated into all intestinal epithelial cell types. The success of research using human enteroids has highlighted the limitations of using animals or in vitro, cancer-derived cell lines to model transport physiology and pathophysiology. For example, curative or preventive therapies for acute enteric infections have been limited, mostly due to the lack of a physiological human intestinal model. However, the human enteroid model enables specific functional studies of secretion and absorption in each intestinal segment as well as observations of the earliest molecular events that occur during enteric infections. This Review describes studies characterizing these human mini-guts as a physiological model to investigate intestinal transport and host-pathogen interactions.

  13. Studying Host-Pathogen Interactions In 3-D: Organotypic Models For Infectious Disease And Drug Development

    Science.gov (United States)

    Nickerson, Cheryl A.; Richter, Emily G.; Ott, C. Mark

    2006-01-01

    Representative, reproducible and high-throughput models of human cells and tissues are critical for a meaningful evaluation of host-pathogen interactions and are an essential component of the research developmental pipeline. The most informative infection models - animals, organ explants and human trials - are not suited for extensive evaluation of pathogenesis mechanisms and screening of candidate drugs. At the other extreme, more cost effective and accessible infection models such as conventional cell culture and static co-culture may not capture physiological and three-dimensional aspects of tissue biology that are important in assessing pathogenesis, and effectiveness and cytotoxicity of therapeutics. Our lab has used innovative bioengineering technology to establish biologically meaningful 3-D models of human tissues that recapitulate many aspects of the differentiated structure and function of the parental tissue in vivo, and we have applied these models to study infectious disease. We have established a variety of different 3-D models that are currently being used in infection studies - including small intestine, colon, lung, placenta, bladder, periodontal ligament, and neuronal models. Published work from our lab has shown that our 3-D models respond to infection with bacterial and viral pathogens in ways that reflect the infection process in vivo. By virtue of their physiological relevance, 3-D cell cultures may also hold significant potential as models to provide insight into the neuropathogenesis of HIV infection. Furthermore, the experimental flexibility, reproducibility, cost-efficiency, and high throughput platform afforded by these 3-D models may have important implications for the design and development of drugs with which to effectively treat neurological complications of HIV infection.

  14. Laboratory simulation reveals significant impacts of ocean acidification on microbial community composition and host-pathogen interactions between the blood clam and Vibrio harveyi.

    Science.gov (United States)

    Zha, Shanjie; Liu, Saixi; Su, Wenhao; Shi, Wei; Xiao, Guoqiang; Yan, Maocang; Liu, Guangxu

    2017-12-01

    It has been suggested that climate change may promote the outbreaks of diseases in the sea through altering the host susceptibility, the pathogen virulence, and the host-pathogen interaction. However, the impacts of ocean acidification (OA) on the pathogen components of bacterial community and the host-pathogen interaction of marine bivalves are still poorly understood. Therefore, 16S rRNA high-throughput sequencing and host-pathogen interaction analysis between blood clam (Tegillarca granosa) and Vibrio harveyi were conducted in the present study to gain a better understanding of the ecological impacts of ocean acidification. The results obtained revealed a significant impact of ocean acidification on the composition of microbial community at laboratory scale. Notably, the abundance of Vibrio, a major group of pathogens to many marine organisms, was significantly increased under ocean acidification condition. In addition, the survival rate and haemolytic activity of V. harveyi were significantly higher in the presence of haemolymph of OA treated T. granosa, indicating a compromised immunity of the clam and enhanced virulence of V. harveyi under future ocean acidification scenarios. Conclusively, the results obtained in this study suggest that future ocean acidification may increase the risk of Vibrio pathogen infection for marine bivalve species, such as blood clams. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Transcriptional response of Nautella italica R11 towards its macroalgal host uncovers new mechanisms of host-pathogen interaction.

    Science.gov (United States)

    Hudson, Jennifer; Gardiner, Melissa; Deshpande, Nandan; Egan, Suhelen

    2018-04-01

    Macroalgae (seaweeds) are essential for the functioning of temperate marine ecosystems, but there is increasing evidence to suggest that their survival is under threat from anthropogenic stressors and disease. Nautella italica R11 is recognized as an aetiological agent of bleaching disease in the red alga, Delisea pulchra. Yet, there is a lack of knowledge surrounding the molecular mechanisms involved in this model host-pathogen interaction. Here we report that mutations in the gene encoding for a LuxR-type quorum sensing transcriptional regulator, RaiR, render N. italica R11 avirulent, suggesting this gene is important for regulating the expression of virulence phenotypes. Using an RNA sequencing approach, we observed a strong transcriptional response of N. italica R11 towards the presence of D. pulchra. In particular, genes involved in oxidative stress resistance, carbohydrate and central metabolism were upregulated in the presence of the host, suggesting a role for these functions in the opportunistic pathogenicity of N. italica R11. Furthermore, we show that RaiR regulates a subset of genes in N. italica R11, including those involved in metabolism and the expression of phage-related proteins. The outcome of this research reveals new functions important for virulence of N. italica R11 and contributes to our greater understanding of the complex factors mitigating microbial diseases in macroalgae. © 2017 John Wiley & Sons Ltd.

  16. Calcineurin orchestrates dimorphic transitions, antifungal drug responses and host-pathogen interactions of the pathogenic mucoralean fungus Mucor circinelloides.

    Science.gov (United States)

    Lee, Soo Chan; Li, Alicia; Calo, Silvia; Inoue, Makoto; Tonthat, Nam K; Bain, Judith M; Louw, Johanna; Shinohara, Mari L; Erwig, Lars P; Schumacher, Maria A; Ko, Dennis C; Heitman, Joseph

    2015-09-01

    Calcineurin plays essential roles in virulence and growth of pathogenic fungi and is a target of the natural products FK506 and Cyclosporine A. In the pathogenic mucoralean fungus Mucor circinelloides, calcineurin mutation or inhibition confers a yeast-locked phenotype indicating that calcineurin governs the dimorphic transition. Genetic analysis in this study reveals that two calcineurin A catalytic subunits (out of three) are functionally diverged. Homology modeling illustrates modes of resistance resulting from amino substitutions in the interface between each calcineurin subunit and the inhibitory drugs. In addition, we show how the dimorphic transition orchestrated by calcineurin programs different outcomes during host-pathogen interactions. For example, when macrophages phagocytose Mucor yeast, subsequent phagosomal maturation occurs, indicating host cells respond appropriately to control the pathogen. On the other hand, upon phagocytosis of spores, macrophages fail to form mature phagosomes. Cytokine production from immune cells differs following exposure to yeast versus spores (which germinate into hyphae). Thus, the morphogenic transition can be targeted as an efficient treatment option against Mucor infection. In addition, genetic analysis (including gene disruption and mutational studies) further strengthens the understanding of calcineurin and provides a foundation to develop antifungal agents targeting calcineurin to deploy against Mucor and other pathogenic fungi. © 2015 John Wiley & Sons Ltd.

  17. Systems Biology Analysis of Temporal In vivo Brucella melitensis and Bovine Transcriptomes Predicts host:Pathogen Protein–Protein Interactions

    Directory of Open Access Journals (Sweden)

    Carlos A. Rossetti

    2017-07-01

    Full Text Available To date, fewer than 200 gene-products have been identified as Brucella virulence factors, and most were characterized individually without considering how they are temporally and coordinately expressed or secreted during the infection process. Here, we describe and analyze the in vivo temporal transcriptional profile of Brucella melitensis during the initial 4 h interaction with cattle. Pathway analysis revealed an activation of the “Two component system” providing evidence that the in vivo Brucella sense and actively regulate their metabolism through the transition to an intracellular lifestyle. Contrarily, other Brucella pathways involved in virulence such as “ABC transporters” and “T4SS system” were repressed suggesting a silencing strategy to avoid stimulation of the host innate immune response very early in the infection process. Also, three flagellum-encoded loci (BMEII0150-0168, BMEII1080-1089, and BMEII1105-1114, the “flagellar assembly” pathway and the cell components “bacterial-type flagellum hook” and “bacterial-type flagellum” were repressed in the tissue-associated B. melitensis, while RopE1 sigma factor, a flagellar repressor, was activated throughout the experiment. These results support the idea that Brucella employ a stealthy strategy at the onset of the infection of susceptible hosts. Further, through systems-level in silico host:pathogen protein–protein interactions simulation and correlation of pathogen gene expression with the host gene perturbations, we identified unanticipated interactions such as VirB11::MAPK8IP1; BtaE::NFKBIA, and 22 kDa OMP precursor::BAD and MAP2K3. These findings are suggestive of new virulence factors and mechanisms responsible for Brucella evasion of the host's protective immune response and the capability to maintain a dormant state. The predicted protein–protein interactions and the points of disruption provide novel insights that will stimulate advanced hypothesis

  18. The conserved clag multigene family of malaria parasites: essential roles in host-pathogen interaction.

    Science.gov (United States)

    Gupta, Ankit; Thiruvengadam, Girija; Desai, Sanjay A

    2015-01-01

    The clag multigene family is strictly conserved in malaria parasites, but absent from neighboring genera of protozoan parasites. Early research pointed to roles in merozoite invasion and infected cell cytoadherence, but more recent studies have implicated channel-mediated uptake of ions and nutrients from host plasma. Here, we review the current understanding of this gene family, which appears to be central to host-parasite interactions and an important therapeutic target. Published by Elsevier Ltd.

  19. Novel experimental Pseudomonas aeruginosa lung infection model mimicking long-term host-pathogen interactions in cystic fibrosis

    DEFF Research Database (Denmark)

    Moser, Claus; van Gennip, Maria; Bjarnsholt, Thomas

    2009-01-01

    Moser C, van Gennip M, Bjarnsholt T, Jensen PO, Lee B, Hougen HP, Calum H, Ciofu O, Givskov M, Molin S, Hoiby N. Novel experimental Pseudomonas aeruginosa lung infection model mimicking long-term host-pathogen interactions in cystic fibrosis. APMIS 2009; 117: 95-107. The dominant cause of premature...... death in patients suffering from cystic fibrosis (CF) is chronic lung infection with Pseudomonas aeruginosa. The chronic lung infection often lasts for decades with just one clone. However, as a result of inflammation, antibiotic treatment and different niches in the lungs, the clone undergoes...... and 2003) of the chronic lung infection of one CF patient using the seaweed alginate embedment model. The results showed that the non-mucoid clones reduced their virulence over time, resulting in faster clearing of the bacteria from the lungs, improved pathology and reduced pulmonary production...

  20. Pharmacological Targeting of the Host-Pathogen Interaction: Alternatives to Classical Antibiotics to Combat Drug-Resistant Superbugs.

    Science.gov (United States)

    Munguia, Jason; Nizet, Victor

    2017-05-01

    The rise of multidrug-resistant pathogens and the dearth of new antibiotic development place an existential strain on successful infectious disease therapy. Breakthrough strategies that go beyond classical antibiotic mechanisms are needed to combat this looming public health catastrophe. Reconceptualizing antibiotic therapy in the richer context of the host-pathogen interaction is required for innovative solutions. By defining specific virulence factors, the essence of a pathogen, and pharmacologically neutralizing their activities, one can block disease progression and sensitize microbes to immune clearance. Likewise, host-directed strategies to boost phagocyte bactericidal activity, enhance leukocyte recruitment, or reverse pathogen-induced immunosuppression seek to replicate the success of cancer immunotherapy in the field of infectious diseases. The answer to the threat of multidrug-resistant pathogens lies 'outside the box' of current antibiotic paradigms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. A Genomic Approach to Unravel Host-Pathogen Interaction in Chelonians: The Example of Testudinid Herpesvirus 3.

    Directory of Open Access Journals (Sweden)

    Francesco C Origgi

    novel information is not only fundamental for the genetic characterization of this virus but is also critical to lay the groundwork for an improved understanding of host-pathogen interactions in chelonians and contribute to tortoise conservation.

  2. A Genomic Approach to Unravel Host-Pathogen Interaction in Chelonians: The Example of Testudinid Herpesvirus 3

    Science.gov (United States)

    Origgi, Francesco C.; Tecilla, Marco; Pilo, Paola; Aloisio, Fabio; Otten, Patricia; Aguilar-Bultet, Lisandra; Sattler, Ursula; Roccabianca, Paola; Romero, Carlos H.; Bloom, David C.; Jacobson, Elliott R.

    2015-01-01

    information is not only fundamental for the genetic characterization of this virus but is also critical to lay the groundwork for an improved understanding of host-pathogen interactions in chelonians and contribute to tortoise conservation. PMID:26244892

  3. Regulation of host-pathogen interactions via the post-transcriptional Csr/Rsm system.

    Science.gov (United States)

    Kusmierek, Maria; Dersch, Petra

    2018-02-01

    A successful colonization of specific hosts requires a rapid and efficient adaptation of the virulence-relevant gene expression program by bacterial pathogens. An important element in this endeavor is the Csr/Rsm system. This multi-component, post-transcriptional control system forms a central hub within complex regulatory networks and coordinately adjusts virulence properties with metabolic and physiological attributes of the pathogen. A key function is elicited by the RNA-binding protein CsrA/RsmA. CsrA/RsmA interacts with numerous target mRNAs, many of which encode crucial virulence factors, and alters their translation, stability or elongation of transcription. Recent studies highlighted that important colonization factors, toxins, and bacterial secretion systems are under CsrA/RsmA control. CsrA/RsmA deficiency impairs host colonization and attenuates virulence, making this post-transcriptional regulator a suitable drug target. The CsrA/RsmA protein can be inactivated through sequestration by non-coding RNAs, or via binding to specific highly abundant mRNAs and interacting proteins. The wide range of interaction partners and RNA targets, as well as the overarching, interlinked genetic control circuits illustrate the complexity of this regulatory system in the different pathogens. Future work addressing spatio-temporal changes of Csr/Rsm-mediated control during the course of an infection will help us to understand how bacteria reprogram their expression profile to cope with continuous changes experienced in colonized niches. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. The Promise of Systems Biology Approaches for Revealing Host Pathogen Interactions in Malaria

    Directory of Open Access Journals (Sweden)

    Meghan Zuck

    2017-11-01

    Full Text Available Despite global eradication efforts over the past century, malaria remains a devastating public health burden, causing almost half a million deaths annually (WHO, 2016. A detailed understanding of the mechanisms that control malaria infection has been hindered by technical challenges of studying a complex parasite life cycle in multiple hosts. While many interventions targeting the parasite have been implemented, the complex biology of Plasmodium poses a major challenge, and must be addressed to enable eradication. New approaches for elucidating key host-parasite interactions, and predicting how the parasite will respond in a variety of biological settings, could dramatically enhance the efficacy and longevity of intervention strategies. The field of systems biology has developed methodologies and principles that are well poised to meet these challenges. In this review, we focus our attention on the Liver Stage of the Plasmodium lifecycle and issue a “call to arms” for using systems biology approaches to forge a new era in malaria research. These approaches will reveal insights into the complex interplay between host and pathogen, and could ultimately lead to novel intervention strategies that contribute to malaria eradication.

  5. Cell penetrating peptides to dissect host-pathogen protein-protein interactions in Theileria -transformed leukocytes

    KAUST Repository

    Haidar, Malak; de Laté , Perle Latré ; Kennedy, Eileen J.; Langsley, Gordon

    2017-01-01

    One powerful application of cell penetrating peptides is the delivery into cells of molecules that function as specific competitors or inhibitors of protein-protein interactions. Ablating defined protein-protein interactions is a refined way

  6. Modelling the host-pathogen interactions of macrophages and Candida albicans using Game Theory and dynamic optimization.

    Science.gov (United States)

    Dühring, Sybille; Ewald, Jan; Germerodt, Sebastian; Kaleta, Christoph; Dandekar, Thomas; Schuster, Stefan

    2017-07-01

    The release of fungal cells following macrophage phagocytosis, called non-lytic expulsion, is reported for several fungal pathogens. On one hand, non-lytic expulsion may benefit the fungus in escaping the microbicidal environment of the phagosome. On the other hand, the macrophage could profit in terms of avoiding its own lysis and being able to undergo proliferation. To analyse the causes of non-lytic expulsion and the relevance of macrophage proliferation in the macrophage- Candida albicans interaction, we employ Evolutionary Game Theory and dynamic optimization in a sequential manner. We establish a game-theoretical model describing the different strategies of the two players after phagocytosis. Depending on the parameter values, we find four different Nash equilibria and determine the influence of the systems state of the host upon the game. As our Nash equilibria are a direct consequence of the model parameterization, we can depict several biological scenarios. A parameter region, where the host response is robust against the fungal infection, is determined. We further apply dynamic optimization to analyse whether macrophage mitosis is relevant in the host-pathogen interaction of macrophages and C. albicans For this, we study the population dynamics of the macrophage- C. albicans interactions and the corresponding optimal controls for the macrophages, indicating the best macrophage strategy of switching from proliferation to attacking fungal cells. © 2017 The Author(s).

  7. A Systems Biology Approach to the Coordination of Defensive and Offensive Molecular Mechanisms in the Innate and Adaptive Host-Pathogen Interaction Networks.

    Science.gov (United States)

    Wu, Chia-Chou; Chen, Bor-Sen

    2016-01-01

    Infected zebrafish coordinates defensive and offensive molecular mechanisms in response to Candida albicans infections, and invasive C. albicans coordinates corresponding molecular mechanisms to interact with the host. However, knowledge of the ensuing infection-activated signaling networks in both host and pathogen and their interspecific crosstalk during the innate and adaptive phases of the infection processes remains incomplete. In the present study, dynamic network modeling, protein interaction databases, and dual transcriptome data from zebrafish and C. albicans during infection were used to infer infection-activated host-pathogen dynamic interaction networks. The consideration of host-pathogen dynamic interaction systems as innate and adaptive loops and subsequent comparisons of inferred innate and adaptive networks indicated previously unrecognized crosstalk between known pathways and suggested roles of immunological memory in the coordination of host defensive and offensive molecular mechanisms to achieve specific and powerful defense against pathogens. Moreover, pathogens enhance intraspecific crosstalk and abrogate host apoptosis to accommodate enhanced host defense mechanisms during the adaptive phase. Accordingly, links between physiological phenomena and changes in the coordination of defensive and offensive molecular mechanisms highlight the importance of host-pathogen molecular interaction networks, and consequent inferences of the host-pathogen relationship could be translated into biomedical applications.

  8. Cell penetrating peptides to dissect host-pathogen protein-protein interactions in Theileria -transformed leukocytes

    KAUST Repository

    Haidar, Malak

    2017-09-08

    One powerful application of cell penetrating peptides is the delivery into cells of molecules that function as specific competitors or inhibitors of protein-protein interactions. Ablating defined protein-protein interactions is a refined way to explore their contribution to a particular cellular phenotype in a given disease context. Cell-penetrating peptides can be synthetically constrained through various chemical modifications that stabilize a given structural fold with the potential to improve competitive binding to specific targets. Theileria-transformed leukocytes display high PKA activity, but PKAis an enzyme that plays key roles in multiple cellular processes; consequently genetic ablation of kinase activity gives rise to a myriad of confounding phenotypes. By contrast, ablation of a specific kinase-substrate interaction has the potential to give more refined information and we illustrate this here by describing how surgically ablating PKA interactions with BAD gives precise information on the type of glycolysis performed by Theileria-transformed leukocytes. In addition, we provide two other examples of how ablating specific protein-protein interactions in Theileria-infected leukocytes leads to precise phenotypes and argue that constrained penetrating peptides have great therapeutic potential to combat infectious diseases in general.

  9. Elucidating Host-Pathogen Interactions Based on Post-Translational Modifications Using Proteomics Approaches

    DEFF Research Database (Denmark)

    Ravikumar, Vaishnavi; Jers, Carsten; Mijakovic, Ivan

    2015-01-01

    can be efficiently applied to gain an insight into the molecular mechanisms involved. The measurement of the proteome and post-translationally modified proteome dynamics using mass spectrometry, results in a wide array of information, such as significant changes in protein expression, protein...... display host specificity through a complex network of molecular interactions that aid their survival and propagation. Co-infection states further lead to complications by increasing the microbial burden and risk factors. Quantitative proteomics based approaches and post-translational modification analysis...... pathogen interactions....

  10. Bright fluorescent Streptococcus pneumoniae for live cell imaging of host-pathogen interactions

    NARCIS (Netherlands)

    Kjos, M.; Aprianto, R.; Fernandes, V.E.; Andrew, P.W.; Strijp, van J.A.G.; Nijland, R.; Veening, J.W.

    2015-01-01

    Streptococcus pneumoniae is a common nasopharyngeal resident in healthy people, but at the same time one of the major causes of infectious diseases such as pneumonia, meningitis and sepsis. The shift from commensal to pathogen and its interaction with host cells is poorly understood. One of the

  11. Bright Fluorescent Streptococcus pneumoniae for Live-Cell Imaging of Host-Pathogen Interactions

    NARCIS (Netherlands)

    Kjos, Morten; Aprianto, Rieza; Fernandes, Vitor E.; Andrew, Peter W.; van Strijp, Jos A. G.; Nijland, Reindert; Veening, Jan-Willem

    Streptococcus pneumoniae is a common nasopharyngeal resident in healthy people but, at the same time, one of the major causes of infectious diseases such as pneumonia, meningitis, and sepsis. The shift from commensal to pathogen and its interaction with host cells are poorly understood. One of the

  12. Genome-Wide Host-Pathogen Interaction Unveiled by Transcriptomic Response of Diamondback Moth to Fungal Infection.

    Directory of Open Access Journals (Sweden)

    Zhen-Jian Chu

    Full Text Available Genome-wide insight into insect pest response to the infection of Beauveria bassiana (fungal insect pathogen is critical for genetic improvement of fungal insecticides but has been poorly explored. We constructed three pairs of transcriptomes of Plutella xylostella larvae at 24, 36 and 48 hours post treatment of infection (hptI and of control (hptC for insight into the host-pathogen interaction at genomic level. There were 2143, 3200 and 2967 host genes differentially expressed at 24, 36 and 48 hptI/hptC respectively. These infection-responsive genes (~15% of the host genome were enriched in various immune processes, such as complement and coagulation cascades, protein digestion and absorption, and drug metabolism-cytochrome P450. Fungal penetration into cuticle and host defense reaction began at 24 hptI, followed by most intensive host immune response at 36 hptI and attenuated immunity at 48 hptI. Contrastingly, 44% of fungal genes were differentially expressed in the infection course and enriched in several biological processes, such as antioxidant activity, peroxidase activity and proteolysis. There were 1636 fungal genes co-expressed during 24-48 hptI, including 116 encoding putative secretion proteins. Our results provide novel insights into the insect-pathogen interaction and help to probe molecular mechanisms involved in the fungal infection to the global pest.

  13. Convergent evolution and mimicry of protein linear motifs in host-pathogen interactions.

    Science.gov (United States)

    Chemes, Lucía Beatriz; de Prat-Gay, Gonzalo; Sánchez, Ignacio Enrique

    2015-06-01

    Pathogen linear motif mimics are highly evolvable elements that facilitate rewiring of host protein interaction networks. Host linear motifs and pathogen mimics differ in sequence, leading to thermodynamic and structural differences in the resulting protein-protein interactions. Moreover, the functional output of a mimic depends on the motif and domain repertoire of the pathogen protein. Regulatory evolution mediated by linear motifs can be understood by measuring evolutionary rates, quantifying positive and negative selection and performing phylogenetic reconstructions of linear motif natural history. Convergent evolution of linear motif mimics is widespread among unrelated proteins from viral, prokaryotic and eukaryotic pathogens and can also take place within individual protein phylogenies. Statistics, biochemistry and laboratory models of infection link pathogen linear motifs to phenotypic traits such as tropism, virulence and oncogenicity. In vitro evolution experiments and analysis of natural sequences suggest that changes in linear motif composition underlie pathogen adaptation to a changing environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Targeting the C-type lectins-mediated host-pathogen interactions with dextran.

    Science.gov (United States)

    Pustylnikov, Sergey; Sagar, Divya; Jain, Pooja; Khan, Zafar K

    2014-01-01

    Dextran, the α-1,6-linked glucose polymer widely used in biology and medicine, promises new applications. Linear dextran applied as a blood plasma substitute demonstrates a high rate of biocompatibility. Dextran is present in foods, drugs, and vaccines and in most cases is applied as a biologically inert substance. In this review we analyze dextran's cellular uptake principles, receptor specificity and, therefore, its ability to interfere with pathogen-lectin interactions: a promising basis for new antimicrobial strategies. Dextran-binding receptors in humans include the DC-SIGN (dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin) family receptors: DC-SIGN (CD209) and L-SIGN (the liver and lymphatic endothelium homologue of DC-SIGN), the mannose receptor (CD206), and langerin. These receptors take part in the uptake of pathogens by dendritic cells and macrophages and may also participate in the modulation of immune responses, mostly shown to be beneficial for pathogens per se rather than host(s). It is logical to predict that owing to receptor-specific interactions, dextran or its derivatives can interfere with these immune responses and improve infection outcome. Recent data support this hypothesis. We consider dextran a promising molecule for the development of lectin-glycan interaction-blocking molecules (such as DC-SIGN inhibitors) that could be applied in the treatment of diseases including tuberculosis, influenza, hepatitis B and C, human immunodeficiency virus infection and AIDS, etc. Dextran derivatives indeed change the pathology of infections dependent on DC-SIGN and mannose receptors. Complete knowledge of specific dextran-lectin interactions may also be important for development of future dextran applications in biological research and medicine.

  15. Host-pathogen Interaction at the Intestinal Mucosa Correlates With Zoonotic Potential of Streptococcus suis

    DEFF Research Database (Denmark)

    Ferrando, Maria Laura; de Greeff, Astrid; van Rooijen, Willemien J. M.

    2015-01-01

    Background. Streptococcus suis has emerged as an important cause of bacterial meningitis in adults. The ingestion of undercooked pork is a risk factor for human S. suis serotype 2 (SS2) infection. Here we provide experimental evidence indicating that the gastrointestinal tract is an entry site of...... be considered a food-borne pathogen. S. suis interaction with human and pig IEC correlates with S. suis serotype and genotype, which can explain the zoonotic potential of SS2....... of SS2 infection. Methods. We developed a noninvasive in vivo model to study oral SS2 infection in piglets. We compared in vitro interaction of S. suis with human and porcine intestinal epithelial cells (IEC). Results. Two out of 15 piglets showed clinical symptoms compatible with S. suis infection 24......Background. Streptococcus suis has emerged as an important cause of bacterial meningitis in adults. The ingestion of undercooked pork is a risk factor for human S. suis serotype 2 (SS2) infection. Here we provide experimental evidence indicating that the gastrointestinal tract is an entry site...

  16. The membrane as the gatekeeper of infection: Cholesterol in host-pathogen interaction.

    Science.gov (United States)

    Kumar, G Aditya; Jafurulla, Md; Chattopadhyay, Amitabha

    2016-09-01

    The cellular plasma membrane serves as a portal for the entry of intracellular pathogens. An essential step for an intracellular pathogen to gain entry into a host cell therefore is to be able to cross the cell membrane. In this review, we highlight the role of host membrane cholesterol in regulating the entry of intracellular pathogens using insights obtained from work on the interaction of Leishmania and Mycobacterium with host cells. The entry of these pathogens is known to be dependent on host membrane cholesterol. Importantly, pathogen entry is inhibited either upon depletion (or complexation), or enrichment of membrane cholesterol. In other words, an optimum level of host membrane cholesterol is necessary for efficient infection by pathogens. In this overall context, we propose a general mechanism, based on cholesterol-induced conformational changes, involving cholesterol binding sites in host cell surface receptors that are implicated in this process. A therapeutic strategy targeting modulation of membrane cholesterol would have the advantage of avoiding the commonly encountered problem of drug resistance in tackling infection by intracellular pathogens. Insights into the role of host membrane cholesterol in pathogen entry would be instrumental in the development of novel therapeutic strategies to effectively tackle intracellular pathogenesis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Xenopus-FV3 host-pathogen interactions and immune evasion.

    Science.gov (United States)

    Jacques, Robert; Edholm, Eva-Stina; Jazz, Sanchez; Odalys, Torres-Luquis; Francisco, De Jesús Andino

    2017-11-01

    We first review fundamental insights into anti-ranavirus immunity learned with the Xenopus laevis/ranavirus FV3 model that are generally applicable to ectothermic vertebrates. We then further investigate FV3 genes involved in immune evasion. Focusing on FV3 knockout (KO) mutants defective for a putative viral caspase activation and recruitment domain-containing (CARD)-like protein (Δ64R-FV3), a β-hydroxysteroid dehydrogenase homolog (Δ52L-FV3), and an immediate-early18kDa protein (FV3-Δ18K), we assessed the involvement of these viral genes in replication, dissemination and interaction with peritoneal macrophages in tadpole and adult frogs. Our results substantiate the role of 64R and 52L as critical immune evasion genes, promoting persistence and dissemination in the host by counteracting type III IFN in tadpoles and type I IFN in adult frogs. Comparably, the substantial accumulation of genome copy numbers and exacerbation of type I and III IFN gene expression responses but deficient release of infectious virus suggests that 18K is a viral regulatory gene. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Variation in the Early Host-Pathogen Interaction of Bovine Macrophages with Divergent Mycobacterium bovis Strains in the United Kingdom.

    Science.gov (United States)

    Jensen, Kirsty; Gallagher, Iain J; Johnston, Nicholas; Welsh, Michael; Skuce, Robin; Williams, John L; Glass, Elizabeth J

    2018-03-01

    Bovine tuberculosis has been an escalating animal health issue in the United Kingdom since the 1980s, even though control policies have been in place for over 60 years. The importance of the genetics of the etiological agent, Mycobacterium bovis , in the reemergence of the disease has been largely overlooked. We compared the interaction between bovine monocyte-derived macrophages (bMDM) and two M. bovis strains, AF2122/97 and G18, representing distinct genotypes currently circulating in the United Kingdom. These M. bovis strains exhibited differences in survival and growth in bMDM. Although uptake was similar, the number of viable intracellular AF2122/97 organisms increased rapidly, while G18 growth was constrained for the first 24 h. AF2122/97 infection induced a greater transcriptional response by bMDM than G18 infection with respect to the number of differentially expressed genes and the fold changes measured. AF2122/97 infection induced more bMDM cell death, with characteristics of necrosis and apoptosis, more inflammasome activation, and a greater type I interferon response than G18. In conclusion, the two investigated M. bovis strains interact in significantly different ways with the host macrophage. In contrast to the relatively silent infection by G18, AF2122/97 induces greater signaling to attract other immune cells and induces host cell death, which may promote secondary infections of naive macrophages. These differences may affect early events in the host-pathogen interaction, including granuloma development, which could in turn alter the progression of the disease. Therefore, the potential involvement of M. bovis genotypes in the reemergence of bovine tuberculosis in the United Kingdom warrants further investigation. Copyright © 2018 Jensen et al.

  19. Alteration of host-pathogen interactions in the wake of climate change - Increasing risk for shellfish associated infections?

    Science.gov (United States)

    Hernroth, Bodil E; Baden, Susanne P

    2018-02-01

    The potential for climate-related spread of infectious diseases through marine systems has been highlighted in several reports. With this review we want to draw attention to less recognized mechanisms behind vector-borne transmission pathways to humans. We have focused on how the immune systems of edible marine shellfish, the blue mussels and Norway lobsters, are affected by climate related environmental stressors. Future ocean acidification (OA) and warming due to climate change constitute a gradually increasing persistent stress with negative trade-off for many organisms. In addition, the stress of recurrent hypoxia, inducing high levels of bioavailable manganese (Mn) is likely to increase in line with climate change. We summarized that OA, hypoxia and elevated levels of Mn did have an overall negative effect on immunity, in some cases also with synergistic effects. On the other hand, moderate increase in temperature seems to have a stimulating effect on antimicrobial activity and may in a future warming scenario counteract the negative effects. However, rising sea surface temperature and climate events causing high land run-off promote the abundance of naturally occurring pathogenic Vibrio and will in addition, bring enteric pathogens which are circulating in society into coastal waters. Moreover, the observed impairments of the immune defense enhance the persistence and occurrence of pathogens in shellfish. This may increase the risk for direct transmission of pathogens to consumers. It is thus essential that in the wake of climate change, sanitary control of coastal waters and seafood must recognize and adapt to the expected alteration of host-pathogen interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Scaling up complexity in host-pathogens interaction models. Comment on "Coupled disease-behavior dynamics on complex networks: A review" by Z. Wang et al.

    Science.gov (United States)

    Aguiar, Maíra

    2015-12-01

    Caused by micro-organisms that are pathogenic to the host, infectious diseases have caused debilitation and premature death to large portions of the human population, leading to serious social-economic concerns. The persistence and increase in the occurrence of infectious diseases as well the emergence or resurgence of vector-borne diseases are closely related with demographic factors such as the uncontrolled urbanization and remarkable population growth, political, social and economical changes, deforestation, development of resistance to insecticides and drugs and increased human travel. In recent years, mathematical modeling became an important tool for the understanding of infectious disease epidemiology and dynamics, addressing ideas about the components of host-pathogen interactions. Acting as a possible tool to understand, predict the spread of infectious diseases these models are also used to evaluate the introduction of intervention strategies like vector control and vaccination. Many scientific papers have been published recently on these topics, and most of the models developed try to incorporate factors focusing on several different aspects of the disease (and eventually biological aspects of the vector), which can imply rich dynamic behavior even in the most basic dynamical models. As one example to be cited, there is a minimalistic dengue model that has shown rich dynamic structures, with bifurcations (Hopf, pitchfork, torus and tangent bifurcations) up to chaotic attractors in unexpected parameter regions [1,2], which was able to describe the large fluctuations observed in empirical outbreak data [3,4].

  1. Loss and gain of function in SERPINB11: an example of a gene under selection on standing variation, with implications for host-pathogen interactions.

    Directory of Open Access Journals (Sweden)

    Susana Seixas

    Full Text Available Serine protease inhibitors (SERPINs are crucial in the regulation of diverse biological processes including inflammation and immune response. SERPINB11, located in the 18q21 gene cluster, is a polymorphic gene/pseudogene coding for a non-inhibitory SERPIN. In a genome-wide scan for recent selection, SERPINB11 was identified as a potential candidate gene for adaptive evolution in Yoruba. The present study sought a better understanding of the evolutionary history of SERPINB11, with special focus on evaluating its selective signature. Through the resequencing of coding and noncoding regions of SERPINB11 in 20 Yorubans and analyzing primate orthologous sequences, we identified a full-length SERPINB11 variant encoding a non-inhibitory SERPIN as the putative candidate of selection--probably driven to higher frequencies by an adaptive response using preexisting variation. In addition, we detected contrasting evolutionary features of SERPINB11 in primates: While primate phylogeny as a whole is under purifying selection, the human lineage shows evidence of positive selection in a few codons, all associated with the active SERPINB11. Comparative modeling studies suggest that positively selected codons reduce SERPINB11's ability to undergo the conformational changes typical of inhibitory SERPINs--suggesting that it is evolving towards a new non-inhibitory function in humans. Significant correlations between SERPINB11 variants and the environmental variables, pastoralism and pathogen richness, have led us to propose a selective advantage through host-pathogen interactions, possibly linked to an adaptive response combating the emergence of infectious diseases in recent human evolution. This work represents the first description of a resurrected gene in humans, and may well exemplify selection on standing variation triggered by drastic ecological shifts.

  2. Virulence on the fly: Drosophila melanogaster as a model genetic organism to decipher host-pathogen interactions.

    NARCIS (Netherlands)

    Limmer, S.; Quintin, J.; Hetru, C.; Ferrandon, D.

    2011-01-01

    To gain an in-depth grasp of infectious processes one has to know the specific interactions between the virulence factors of the pathogen and the host defense mechanisms. A thorough understanding is crucial for identifying potential new drug targets and designing drugs against which the pathogens

  3. Signatures of co-evolutionary host-pathogen interactions in the genome of the entomopathogenic nematode Steinernema carpocapsae.

    Science.gov (United States)

    Flores-Ponce, Mitzi; Vallebueno-Estrada, Miguel; González-Orozco, Eduardo; Ramos-Aboites, Hilda E; García-Chávez, J Noé; Simões, Nelson; Montiel, Rafael

    2017-04-26

    The entomopathogenic nematode Steinernema carpocapsae has been used worldwide as a biocontrol agent for insect pests, making it an interesting model for understanding parasite-host interactions. Two models propose that these interactions are co-evolutionary processes in such a way that equilibrium is never reached. In one model, known as "arms race", new alleles in relevant genes are fixed in both host and pathogens by directional positive selection, producing recurrent and alternating selective sweeps. In the other model, known as"trench warfare", persistent dynamic fluctuations in allele frequencies are sustained by balancing selection. There are some examples of genes evolving according to both models, however, it is not clear to what extent these interactions might alter genome-level evolutionary patterns and intraspecific diversity. Here we investigate some of these aspects by studying genomic variation in S. carpocapsae and other pathogenic and free-living nematodes from phylogenetic clades IV and V. To look for signatures of an arms-race dynamic, we conducted massive scans to detect directional positive selection in interspecific data. In free-living nematodes, we detected a significantly higher proportion of genes with sites under positive selection than in parasitic nematodes. However, in these genes, we found more enriched Gene Ontology terms in parasites. To detect possible effects of dynamic polymorphisms interactions we looked for signatures of balancing selection in intraspecific genomic data. The observed distribution of Tajima's D values in S. carpocapsae was more skewed to positive values and significantly different from the observed distribution in the free-living Caenorhabditis briggsae. Also, the proportion of significant positive values of Tajima's D was elevated in genes that were differentially expressed after induction with insect tissues as compared to both non-differentially expressed genes and the global scan. Our study provides a first

  4. Use of an Optical Trap for Study of Host-Pathogen Interactions for Dynamic Live Cell Imaging

    OpenAIRE

    Tam, Jenny M.; Castro, Carlos E.; Heath, Robert J. W.; Mansour, Michael K.; Cardenas, Michael L.; Xavier, Ramnik J.; Lang, Matthew J.; Vyas, Jatin M.

    2011-01-01

    Dynamic live cell imaging allows direct visualization of real-time interactions between cells of the immune system1, 2; however, the lack of spatial and temporal control between the phagocytic cell and microbe has rendered focused observations into the initial interactions of host response to pathogens difficult. Historically, intercellular contact events such as phagocytosis3 have been imaged by mixing two cell types, and then continuously scanning the field-of-view to find serendipitous int...

  5. Protease Inhibitors in Tick Saliva: The Role of Serpins and Cystatins in Tick-host-Pathogen Interaction

    Czech Academy of Sciences Publication Activity Database

    Chmelař, J.; Kotál, Jan; Langhansová, Helena; Kotsyfakis, Michalis

    2017-01-01

    Roč. 7, MAY 29 (2017), č. článku 276. ISSN 2235-2988 Institutional support: RVO:60077344 Keywords : tick-host interaction * immunomodulation * protease inhibitors * serpins * cystatins Subject RIV: EC - Immunology OBOR OECD: Immunology Impact factor: 4.300, year: 2016

  6. Group X hybrid histidine kinase Chk1 is dispensable for stress adaptation, host-pathogen interactions and virulence in the opportunistic yeast Candida guilliermondii.

    Science.gov (United States)

    Navarro-Arias, María J; Dementhon, Karine; Defosse, Tatiana A; Foureau, Emilien; Courdavault, Vincent; Clastre, Marc; Le Gal, Solène; Nevez, Gilles; Le Govic, Yohann; Bouchara, Jean-Philippe; Giglioli-Guivarc'h, Nathalie; Noël, Thierry; Mora-Montes, Hector M; Papon, Nicolas

    2017-09-01

    Hybrid histidine kinases (HHKs) progressively emerge as prominent sensing proteins in the fungal kingdom and as ideal targets for future therapeutics. The group X HHK is of major interest, since it was demonstrated to play an important role in stress adaptation, host-pathogen interactions and virulence in some yeast and mold models, and particularly Chk1, that corresponds to the sole group X HHK in Candida albicans. In the present work, we investigated the role of Chk1 in the low-virulence species Candida guilliermondii, in order to gain insight into putative conservation of the role of group X HHK in opportunistic yeasts. We demonstrated that disruption of the corresponding gene CHK1 does not influence growth, stress tolerance, drug susceptibility, protein glycosylation or cell wall composition in C. guilliermondii. In addition, we showed that loss of CHK1 does not affect C. guilliermondii ability to interact with macrophages and to stimulate cytokine production by human peripheral blood mononuclear cells. Finally, the C. guilliermondii chk1 null mutant was found to be as virulent as the wild-type strain in the experimental model Galleria mellonella. Taken together, our results demonstrate that group X HHK function is not conserved in Candida species. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  7. Use of an optical trap for study of host-pathogen interactions for dynamic live cell imaging.

    Science.gov (United States)

    Tam, Jenny M; Castro, Carlos E; Heath, Robert J W; Mansour, Michael K; Cardenas, Michael L; Xavier, Ramnik J; Lang, Matthew J; Vyas, Jatin M

    2011-07-28

    Dynamic live cell imaging allows direct visualization of real-time interactions between cells of the immune system(1, 2); however, the lack of spatial and temporal control between the phagocytic cell and microbe has rendered focused observations into the initial interactions of host response to pathogens difficult. Historically, intercellular contact events such as phagocytosis(3) have been imaged by mixing two cell types, and then continuously scanning the field-of-view to find serendipitous intercellular contacts at the appropriate stage of interaction. The stochastic nature of these events renders this process tedious, and it is difficult to observe early or fleeting events in cell-cell contact by this approach. This method requires finding cell pairs that are on the verge of contact, and observing them until they consummate their contact, or do not. To address these limitations, we use optical trapping as a non-invasive, non-destructive, but fast and effective method to position cells in culture. Optical traps, or optical tweezers, are increasingly utilized in biological research to capture and physically manipulate cells and other micron-sized particles in three dimensions(4). Radiation pressure was first observed and applied to optical tweezer systems in 1970(5, 6), and was first used to control biological specimens in 1987(7). Since then, optical tweezers have matured into a technology to probe a variety of biological phenomena(8-13). We describe a method(14) that advances live cell imaging by integrating an optical trap with spinning disk confocal microscopy with temperature and humidity control to provide exquisite spatial and temporal control of pathogenic organisms in a physiological environment to facilitate interactions with host cells, as determined by the operator. Live, pathogenic organisms like Candida albicans and Aspergillus fumigatus, which can cause potentially lethal, invasive infections in immunocompromised individuals(15, 16) (e.g. AIDS

  8. The co-transcriptome of uropathogenic Escherichia coli-infected mouse macrophages reveals new insights into host-pathogen interactions

    KAUST Repository

    Mavromatis, Charalampos Harris; Bokil, Nilesh J.; Totsika, Makrina; Kakkanat, Asha; Schaale, Kolja; Cannistraci, Carlo V.; Ryu, Tae Woo; Beatson, Scott A.; Ulett, Glen C.; Schembri, Mark A.; Sweet, Matthew J.; Ravasi, Timothy

    2015-01-01

    Urinary tract infections (UTI) are among the most common infections in humans. Uropathogenic Escherichia coli (UPEC) can invade and replicate within bladder epithelial cells, and some UPEC strains can also survive within macrophages. To understand the UPEC transcriptional programme associated with intramacrophage survival, we performed host–pathogen co-transcriptome analyses using RNA sequencing. Mouse bone marrow-derived macrophages (BMMs) were challenged over a 24 h time course with two UPEC reference strains that possess contrasting intramacrophage phenotypes: UTI89, which survives in BMMs, and 83972, which is killed by BMMs. Neither of these strains caused significant BMM cell death at the low multiplicity of infection that was used in this study. We developed an effective computational framework that simultaneously separated, annotated and quantified the mammalian and bacterial transcriptomes. Bone marrow-derived macrophages responded to the two UPEC strains with a broadly similar gene expression programme. In contrast, the transcriptional responses of the UPEC strains diverged markedly from each other. We identified UTI89 genes up-regulated at 24 h post-infection, and hypothesized that some may contribute to intramacrophage survival. Indeed, we showed that deletion of one such gene (pspA) significantly reduced UTI89 survival within BMMs. Our study provides a technological framework for simultaneously capturing global changes at the transcriptional level in co-cultures, and has generated new insights into the mechanisms that UPEC use to persist within the intramacrophage environment.

  9. Distinct intensity of host-pathogen interactions in Chlamydia psittaci- and Chlamydia abortus-infected chicken embryos.

    Science.gov (United States)

    Braukmann, Maria; Sachse, Konrad; Jacobsen, Ilse D; Westermann, Martin; Menge, Christian; Saluz, Hans-Peter; Berndt, Angela

    2012-09-01

    Factors and mechanisms determining the differences in virulence and host specificity between the zoonotic agents Chlamydia psittaci and Chlamydia abortus are still largely unknown. In the present study, two strains were compared for their invasiveness, virulence, and capability of eliciting an immune response in chicken embryos. On breeding day 10, embryonated chicken eggs were inoculated with 5 × 10(4) inclusion-forming units. As shown by immunohistochemistry and quantitative real-time PCR, C. psittaci displayed a significantly better capability of disseminating in the chorioallantoic membrane (CAM) and internal organs than C. abortus. The higher infectious potential of C. psittaci in birds was underlined by significantly higher mRNA expression rates of essential chlamydial genes, such as incA, groEL (in CAM, liver, and spleen), cpaf, and ftsW (in CAM). Although the immune responses to both pathogens were similar, C. psittaci elicited higher macrophage numbers and a stronger expression of a subset of immune-related proteins. The data imply that invasiveness of Chlamydia spp. and propagation in the host are not solely dependent on the level of host immune response but, even to a greater extent, on the expression of bacterial factors related to virulence. The fact that C. psittaci has coped far better than C. abortus with the avian embryo's response by upregulating essential genes may be a key to understanding the mechanisms underlying host adaptation and etiopathology.

  10. Comparative and functional genomics of Legionella identified eukaryotic like proteins as key players in host-pathogen interactions

    Directory of Open Access Journals (Sweden)

    Laura eGomez-Valero

    2011-10-01

    Full Text Available Although best known for its ability to cause severe pneumonia in people whose immune defenses are weakened, Legionella pneumophila and Legionella longbeachae are two species of a large genus of bacteria that are ubiquitous in nature, where they parasitize protozoa. Adaptation to the host environment and exploitation of host cell functions are critical for the success of these intracellular pathogens. The establishment and publication of the complete genome sequences of L. pneumophila and L. longbeachae isolates paved the way for major breakthroughs in understanding the biology of these organisms. In this review we present the knowledge gained from the analyses and comparison of the complete genome sequences of different L. pneumophila and L. longbeachae strains. Emphasis is given on putative virulence and Legionella life cycle related functions, such as the identification of an extended array of eukaryotic-like proteins, many of which have been shown to modulate host cell functions to the pathogen's advantage. Surprisingly, many of the eukaryotic domain proteins identified in L. pneumophila as well as many substrates of the Dot/Icm type IV secretion system essential for intracellular replication are different between these two species, although they cause the same disease. Finally, evolutionary aspects regarding the eukaryotic like proteins in Legionella are discussed.

  11. The co-transcriptome of uropathogenic Escherichia coli-infected mouse macrophages reveals new insights into host-pathogen interactions

    KAUST Repository

    Mavromatis, Charalampos Harris

    2015-01-24

    Urinary tract infections (UTI) are among the most common infections in humans. Uropathogenic Escherichia coli (UPEC) can invade and replicate within bladder epithelial cells, and some UPEC strains can also survive within macrophages. To understand the UPEC transcriptional programme associated with intramacrophage survival, we performed host–pathogen co-transcriptome analyses using RNA sequencing. Mouse bone marrow-derived macrophages (BMMs) were challenged over a 24 h time course with two UPEC reference strains that possess contrasting intramacrophage phenotypes: UTI89, which survives in BMMs, and 83972, which is killed by BMMs. Neither of these strains caused significant BMM cell death at the low multiplicity of infection that was used in this study. We developed an effective computational framework that simultaneously separated, annotated and quantified the mammalian and bacterial transcriptomes. Bone marrow-derived macrophages responded to the two UPEC strains with a broadly similar gene expression programme. In contrast, the transcriptional responses of the UPEC strains diverged markedly from each other. We identified UTI89 genes up-regulated at 24 h post-infection, and hypothesized that some may contribute to intramacrophage survival. Indeed, we showed that deletion of one such gene (pspA) significantly reduced UTI89 survival within BMMs. Our study provides a technological framework for simultaneously capturing global changes at the transcriptional level in co-cultures, and has generated new insights into the mechanisms that UPEC use to persist within the intramacrophage environment.

  12. Wheat Ammonium Transporter (AMT) Gene Family: Diversity and Possible Role in Host-Pathogen Interaction with Stem Rust.

    Science.gov (United States)

    Li, Tianya; Liao, Kai; Xu, Xiaofeng; Gao, Yue; Wang, Ziyuan; Zhu, Xiaofeng; Jia, Baolei; Xuan, Yuanhu

    2017-01-01

    Ammonium transporter (AMT) proteins have been reported in many plants, but no comprehensive analysis was performed in wheat. In this study, we identified 23 AMT members (hereafter TaAMTs) using a protein homology search in wheat genome. Tissue-specific expression analysis showed that TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a were relatively more highly expressed in comparison with other TaAMTs . TaAMT1;1a, TaAMT1;1b, and TaAMT1;3a-GFP were localized in the plasma membrane in tobacco leaves, and TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a successfully complemented a yeast 31019b strain in which ammonium uptake was deficient. In addition, the expression of TaAMT1;1b in an Arabidopsis AMT quadruple mutant ( qko ) successfully restored [Formula: see text] uptake ability. Resupply of [Formula: see text] rapidly increased cellular [Formula: see text] contents and suppressed expression of TaAMT1;3a , but not of TaAMT;1;1a and TaAMT1;1b expressions. Expression of TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a was not changed in leaves after [Formula: see text] resupply. In contrast, nitrogen (N) deprivation induced TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a gene expressions in the roots and leaves. Expression analysis in the leaves of the stem rust-susceptible wheat line "Little Club" and the rust-tolerant strain "Mini 2761" revealed that TaAMT1;1a, TaAMT1;1b , and TaAMT1;3a were specifically induced in the former but not in the latter. Rust-susceptible wheat plants grown under N-free conditions exhibited a lower disease index than plants grown with [Formula: see text] as the sole N source in the medium after infection with Puccinia graminis f. sp. tritici , suggesting that [Formula: see text] and its transport may facilitate the infection of wheat stem rust disease. Our findings may be important for understanding the potential function TaAMTs in wheat plants.

  13. Agent-based dynamic knowledge representation of Pseudomonas aeruginosa virulence activation in the stressed gut: Towards characterizing host-pathogen interactions in gut-derived sepsis.

    Science.gov (United States)

    Seal, John B; Alverdy, John C; Zaborina, Olga; An, Gary

    2011-09-19

    There is a growing realization that alterations in host-pathogen interactions (HPI) can generate disease phenotypes without pathogen invasion. The gut represents a prime region where such HPI can arise and manifest. Under normal conditions intestinal microbial communities maintain a stable, mutually beneficial ecosystem. However, host stress can lead to changes in environmental conditions that shift the nature of the host-microbe dialogue, resulting in escalation of virulence expression, immune activation and ultimately systemic disease. Effective modulation of these dynamics requires the ability to characterize the complexity of the HPI, and dynamic computational modeling can aid in this task. Agent-based modeling is a computational method that is suited to representing spatially diverse, dynamical systems. We propose that dynamic knowledge representation of gut HPI with agent-based modeling will aid in the investigation of the pathogenesis of gut-derived sepsis. An agent-based model (ABM) of virulence regulation in Pseudomonas aeruginosa was developed by translating bacterial and host cell sense-and-response mechanisms into behavioral rules for computational agents and integrated into a virtual environment representing the host-microbe interface in the gut. The resulting gut milieu ABM (GMABM) was used to: 1) investigate a potential clinically relevant laboratory experimental condition not yet developed--i.e. non-lethal transient segmental intestinal ischemia, 2) examine the sufficiency of existing hypotheses to explain experimental data--i.e. lethality in a model of major surgical insult and stress, and 3) produce behavior to potentially guide future experimental design--i.e. suggested sample points for a potential laboratory model of non-lethal transient intestinal ischemia. Furthermore, hypotheses were generated to explain certain discrepancies between the behaviors of the GMABM and biological experiments, and new investigatory avenues proposed to test those

  14. Agent-based dynamic knowledge representation of Pseudomonas aeruginosa virulence activation in the stressed gut: Towards characterizing host-pathogen interactions in gut-derived sepsis

    Directory of Open Access Journals (Sweden)

    Zaborina Olga

    2011-09-01

    Full Text Available Abstract Background There is a growing realization that alterations in host-pathogen interactions (HPI can generate disease phenotypes without pathogen invasion. The gut represents a prime region where such HPI can arise and manifest. Under normal conditions intestinal microbial communities maintain a stable, mutually beneficial ecosystem. However, host stress can lead to changes in environmental conditions that shift the nature of the host-microbe dialogue, resulting in escalation of virulence expression, immune activation and ultimately systemic disease. Effective modulation of these dynamics requires the ability to characterize the complexity of the HPI, and dynamic computational modeling can aid in this task. Agent-based modeling is a computational method that is suited to representing spatially diverse, dynamical systems. We propose that dynamic knowledge representation of gut HPI with agent-based modeling will aid in the investigation of the pathogenesis of gut-derived sepsis. Methodology/Principal Findings An agent-based model (ABM of virulence regulation in Pseudomonas aeruginosa was developed by translating bacterial and host cell sense-and-response mechanisms into behavioral rules for computational agents and integrated into a virtual environment representing the host-microbe interface in the gut. The resulting gut milieu ABM (GMABM was used to: 1 investigate a potential clinically relevant laboratory experimental condition not yet developed - i.e. non-lethal transient segmental intestinal ischemia, 2 examine the sufficiency of existing hypotheses to explain experimental data - i.e. lethality in a model of major surgical insult and stress, and 3 produce behavior to potentially guide future experimental design - i.e. suggested sample points for a potential laboratory model of non-lethal transient intestinal ischemia. Furthermore, hypotheses were generated to explain certain discrepancies between the behaviors of the GMABM and biological

  15. Mapping of the Co-Transcriptomes of UPEC-Infected Macrophages Reveals New Insights into the Molecular Basis of Host-Pathogen Interactions in Human and Mouse

    KAUST Repository

    Mavromatis, Charalampos Harris

    2014-01-01

    Urinary tract infections (UTI) are among the most common infections in humans. Uropathogenic Escherichia coli (UPEC), the main causative agent of UTIs, can invade and replicate within bladder epithelial cells, and recent evidence demonstrated that some UPEC strains also survive within macrophages. To understand the mechanisms of host subversion that enable UPEC to survive within macrophages, and the contribution of macrophages to UPEC-mediated pathology, I performed hostpathogen co-transcriptome analyses using RNA sequencing. I developed an effective computational framework that simultaneously separated, annotated, and quantified the mammalian and bacterial transcriptomes. First, mouse bone morrow-derived macrophages (BMM) were challenged over a 24 h time course with UPEC reference strains, UTI89 (cystitis strain), 83972 and VR50 (asymptomatic bacteriuria strains) that possess contrasting intramacrophage phenotypes. My results showed that BMM responded to the three different UPEC strains with broadly similar gene expression programs. In contrast to the conserved pattern of BMM responses, the transcriptional responses of the different UPEC strains diverged markedly from each other. Hypothesizing that genes upregulated at 24 h post-infection may contribute to intramacrophage survival, I identified UTI89 genes upregulated at this time point, and showed that deletion of one of these genes (pspA) compromised intramacrophage survival of UPEC strain UTI89. Second, human monocyte-derived macrophages (HMDM) and BMM were challenged over a 24 h course with the UPEC strain EC958, a globally disseminated, multi-drug resistant strain. My analysis identified extensive divergence in UPEC-regulated orthologous gene expression between HMDM and BMM, and I validated both known and novel genes in the context of differential regulation. On the contrary, the transcriptional response of EC958 showed a broad conservation across both mammalian intramacrophage environments. My study thus

  16. Host-pathogen interactions between the human innate immune system and Candida albicans - Understanding and modeling defense and evasion strategies

    Directory of Open Access Journals (Sweden)

    Sybille eDühring

    2015-06-01

    Full Text Available The diploid, polymorphic yeast Candida albicans is one of the most important humanpathogenic fungi. C. albicans can grow, proliferate and coexist as a commensal on or within thehuman host for a long time. Alterations in the host environment, however, can render C. albicansvirulent. In this review, we describe the immunological cross-talk between C. albicans and thehuman innate immune system. We give an overview in form of pairs of human defense strategiesincluding immunological mechanisms as well as general stressors such as nutrient limitation,pH, fever etc. and the corresponding fungal response and evasion mechanisms. FurthermoreComputational Systems Biology approaches to model and investigate these complex interactionare highlighted with a special focus on game-theoretical methods and agent-based models. Anoutlook on interesting questions to be tackled by Systems Biology regarding entangled defenseand evasion mechanisms is given.

  17. Aspergillus flavus infection triggered immune responses and host-pathogen cross-talks in groundnut during in-vitro seed colonization

    Science.gov (United States)

    Aflatoxin contamination, caused by fungal pathogen Aspergillus flavus, is a major quality and health problem delimiting the trade and consumption of groundnut (Arachis hypogaea L.) worldwide. RNA-seq approach was deployed to understand the host-pathogen interaction by identifying differentially expr...

  18. The apolipoprotein L family of programmed cell death and immunity genes rapidly evolved in primates at discrete sites of host-pathogen interactions.

    Science.gov (United States)

    Smith, Eric E; Malik, Harmit S

    2009-05-01

    Apolipoprotein L1 (APOL1) is a human protein that confers immunity to Trypanosoma brucei infections but can be countered by a trypanosome-encoded antagonist SRA. APOL1 belongs to a family of programmed cell death genes whose proteins can initiate host apoptosis or autophagic death. We report here that all six members of the APOL gene family (APOL1-6) present in humans have rapidly evolved in simian primates. APOL6, furthermore, shows evidence of an adaptive sweep during recent human evolution. In each APOL gene tested, we found rapidly evolving codons in or adjacent to the SRA-interacting protein domain (SID), which is the domain of APOL1 that interacts with SRA. In APOL6, we also found a rapidly changing 13-amino-acid cluster in the membrane-addressing domain (MAD), which putatively functions as a pH sensor and regulator of cell death. We predict that APOL genes are antagonized by pathogens by at least two distinct mechanisms: SID antagonists, which include SRA, that interact with the SID of various APOL proteins, and MAD antagonists that interact with the MAD hinge base of APOL6. These antagonists either block or prematurely cause APOL-mediated programmed cell death of host cells to benefit the infecting pathogen. These putative interactions must occur inside host cells, in contrast to secreted APOL1 that trafficks to the trypanosome lysosome. Hence, the dynamic APOL gene family appears to be an important link between programmed cell death of host cells and immunity to pathogens.

  19. Establishment of Myotis myotis cell lines--model for investigation of host-pathogen interaction in a natural host for emerging viruses.

    Directory of Open Access Journals (Sweden)

    Xiaocui He

    Full Text Available Bats are found to be the natural reservoirs for many emerging viruses. In most cases, severe clinical signs caused by such virus infections are normally not seen in bats. This indicates differences in the virus-host interactions and underlines the necessity to develop natural host related models to study these phenomena. Due to the strict protection of European bat species, immortalized cell lines are the only alternative to investigate the innate anti-virus immune mechanisms. Here, we report about the establishment and functional characterization of Myotis myotis derived cell lines from different tissues: brain (MmBr, tonsil (MmTo, peritoneal cavity (MmPca, nasal epithelium (MmNep and nervus olfactorius (MmNol after immortalization by SV 40 large T antigen. The usefulness of these cell lines to study antiviral responses has been confirmed by analysis of their susceptibility to lyssavirus infection and the mRNA patterns of immune-relevant genes after poly I:C stimulation. Performed experiments indicated varying susceptibility to lyssavirus infection with MmBr being considerably less susceptible than the other cell lines. Further investigation demonstrated a strong activation of interferon mediated antiviral response in MmBr contributing to its resistance. The pattern recognition receptors: RIG-I and MDA5 were highly up-regulated during rabies virus infection in MmBr, suggesting their involvement in promotion of antiviral responses. The presence of CD14 and CD68 in MmBr suggested MmBr cells are microglia-like cells which play a key role in host defense against infections in the central nervous system (CNS. Thus the expression pattern of MmBr combined with the observed limitation of lyssavirus replication underpin a protective mechanism of the CNS controlling the lyssavirus infection. Overall, the established cell lines are important tools to analyze antiviral innate immunity in M. myotis against neurotropic virus infections and present a valuable

  20. Establishment of Myotis myotis cell lines--model for investigation of host-pathogen interaction in a natural host for emerging viruses.

    Science.gov (United States)

    He, Xiaocui; Korytář, Tomáš; Zhu, Yaqing; Pikula, Jiří; Bandouchova, Hana; Zukal, Jan; Köllner, Bernd

    2014-01-01

    Bats are found to be the natural reservoirs for many emerging viruses. In most cases, severe clinical signs caused by such virus infections are normally not seen in bats. This indicates differences in the virus-host interactions and underlines the necessity to develop natural host related models to study these phenomena. Due to the strict protection of European bat species, immortalized cell lines are the only alternative to investigate the innate anti-virus immune mechanisms. Here, we report about the establishment and functional characterization of Myotis myotis derived cell lines from different tissues: brain (MmBr), tonsil (MmTo), peritoneal cavity (MmPca), nasal epithelium (MmNep) and nervus olfactorius (MmNol) after immortalization by SV 40 large T antigen. The usefulness of these cell lines to study antiviral responses has been confirmed by analysis of their susceptibility to lyssavirus infection and the mRNA patterns of immune-relevant genes after poly I:C stimulation. Performed experiments indicated varying susceptibility to lyssavirus infection with MmBr being considerably less susceptible than the other cell lines. Further investigation demonstrated a strong activation of interferon mediated antiviral response in MmBr contributing to its resistance. The pattern recognition receptors: RIG-I and MDA5 were highly up-regulated during rabies virus infection in MmBr, suggesting their involvement in promotion of antiviral responses. The presence of CD14 and CD68 in MmBr suggested MmBr cells are microglia-like cells which play a key role in host defense against infections in the central nervous system (CNS). Thus the expression pattern of MmBr combined with the observed limitation of lyssavirus replication underpin a protective mechanism of the CNS controlling the lyssavirus infection. Overall, the established cell lines are important tools to analyze antiviral innate immunity in M. myotis against neurotropic virus infections and present a valuable tool for a

  1. Establishment of Myotis myotis Cell Lines - Model for Investigation of Host-Pathogen Interaction in a Natural Host for Emerging Viruses

    Science.gov (United States)

    He, Xiaocui; Korytář, Tomáš; Zhu, Yaqing; Pikula, Jiří; Bandouchova, Hana; Zukal, Jan; Köllner, Bernd

    2014-01-01

    Bats are found to be the natural reservoirs for many emerging viruses. In most cases, severe clinical signs caused by such virus infections are normally not seen in bats. This indicates differences in the virus-host interactions and underlines the necessity to develop natural host related models to study these phenomena. Due to the strict protection of European bat species, immortalized cell lines are the only alternative to investigate the innate anti-virus immune mechanisms. Here, we report about the establishment and functional characterization of Myotis myotis derived cell lines from different tissues: brain (MmBr), tonsil (MmTo), peritoneal cavity (MmPca), nasal epithelium (MmNep) and nervus olfactorius (MmNol) after immortalization by SV 40 large T antigen. The usefulness of these cell lines to study antiviral responses has been confirmed by analysis of their susceptibility to lyssavirus infection and the mRNA patterns of immune-relevant genes after poly I:C stimulation. Performed experiments indicated varying susceptibility to lyssavirus infection with MmBr being considerably less susceptible than the other cell lines. Further investigation demonstrated a strong activation of interferon mediated antiviral response in MmBr contributing to its resistance. The pattern recognition receptors: RIG-I and MDA5 were highly up-regulated during rabies virus infection in MmBr, suggesting their involvement in promotion of antiviral responses. The presence of CD14 and CD68 in MmBr suggested MmBr cells are microglia-like cells which play a key role in host defense against infections in the central nervous system (CNS). Thus the expression pattern of MmBr combined with the observed limitation of lyssavirus replication underpin a protective mechanism of the CNS controlling the lyssavirus infection. Overall, the established cell lines are important tools to analyze antiviral innate immunity in M. myotis against neurotropic virus infections and present a valuable tool for a

  2. The systems biology of host pathogen interactions.

    Directory of Open Access Journals (Sweden)

    Nikolai Petrovsky

    2013-06-01

    Full Text Available Infectious diseases constitute a major public health burden, particularly in developing countries. Amongst the pathogens afflicting humans, malaria, HIV, shigellosis and tuberculosis (TB cause a large number of deaths. Whilst antivirals, antibiotics and antiparasitic drugs have all helped to reduce the burden of disease, problems of drug resistance are increasingly common, presenting the need to come up with alternative approaches to disease prevention. Ideally, effective prophylactic vaccines would be developed against each of these infections, but unfortunately with the exception of TB, no vaccine is currently available against the other three infections. Baring a breakthrough, coming for example from the application of newer more potent adjuvants to vaccine candidates, new paradigms are needed to help tackle these infectious diseases.

  3. Host-pathogen interplay of Haemophilus ducreyi.

    Science.gov (United States)

    Janowicz, Diane M; Li, Wei; Bauer, Margaret E

    2010-02-01

    Haemophilus ducreyi, the causative agent of the sexually transmitted infection chancroid, is primarily a pathogen of human skin. During infection, H. ducreyi thrives extracellularly in a milieu of professional phagocytes and other antibacterial components of the innate and adaptive immune responses. This review summarizes our understanding of the interplay between this pathogen and its host that leads to development and persistence of disease. H. ducreyi expresses key virulence mechanisms to resist host defenses. The secreted LspA proteins are tyrosine-phosphorylated by host kinases, which may contribute to their antiphagocytic effector function. The serum resistance and adherence functions of DsrA map to separate domains of this multifunctional virulence factor. An influx transporter protects H. ducreyi from killing by the antimicrobial peptide LL37. Regulatory genes have been identified that may coordinate virulence factor expression during disease. Dendritic cells and natural killer cells respond to H. ducreyi and may be involved in determining the differential outcomes of infection observed in humans. A human model of H. ducreyi infection has provided insights into virulence mechanisms that allow this human-specific pathogen to survive immune pressures. Components of the human innate immune system may also determine the ultimate fate of H. ducreyi infection by driving either clearance of the organism or an ineffective response that allows disease progression.

  4. Using a Bayesian network to clarify areas requiring research in a host-pathogen system.

    Science.gov (United States)

    Bower, D S; Mengersen, K; Alford, R A; Schwarzkopf, L

    2017-12-01

    Bayesian network analyses can be used to interactively change the strength of effect of variables in a model to explore complex relationships in new ways. In doing so, they allow one to identify influential nodes that are not well studied empirically so that future research can be prioritized. We identified relationships in host and pathogen biology to examine disease-driven declines of amphibians associated with amphibian chytrid fungus (Batrachochytrium dendrobatidis). We constructed a Bayesian network consisting of behavioral, genetic, physiological, and environmental variables that influence disease and used them to predict host population trends. We varied the impacts of specific variables in the model to reveal factors with the most influence on host population trend. The behavior of the nodes (the way in which the variables probabilistically responded to changes in states of the parents, which are the nodes or variables that directly influenced them in the graphical model) was consistent with published results. The frog population had a 49% probability of decline when all states were set at their original values, and this probability increased when body temperatures were cold, the immune system was not suppressing infection, and the ambient environment was conducive to growth of B. dendrobatidis. These findings suggest the construction of our model reflected the complex relationships characteristic of host-pathogen interactions. Changes to climatic variables alone did not strongly influence the probability of population decline, which suggests that climate interacts with other factors such as the capacity of the frog immune system to suppress disease. Changes to the adaptive immune system and disease reservoirs had a large effect on the population trend, but there was little empirical information available for model construction. Our model inputs can be used as a base to examine other systems, and our results show that such analyses are useful tools for

  5. Dermatófitos: interação patógeno-hospedeiro e resistência a antifúngicos Dermatophytes: host-pathogen interaction and antifungal resistance

    Directory of Open Access Journals (Sweden)

    Nalu Teixera de Aguiar Peres

    2010-10-01

    Full Text Available As micoses cutâneas estão entre as infecções mais comuns em humanos e se tornaram um importante problema de saúde pública, principalmente por causarem infecções invasivas em pacientes imunodeprimidos. Durante a infecção, a interação dermatófito-hospedeiro desencadeia adaptações metabólicas específicas que permitem aos patógenos aderirem e penetrarem no tecido, remodelando seu metabolismo para captar nutrientes e superar os mecanismos de defesa do hospedeiro. Esse remodelamento metabólico e a inter-relação entre metabolismo, morfogênese e resposta ao estresse são importantes fatores que estão sendo intensamente avaliados em diversos patógenos. As células do hospedeiro também respondem aos estímulos do patógeno, ativando vias de sinalização intracelular que culminam no desencadeamento de uma resposta imune contra o agente infeccioso. O entendimento molecular dessas respostas metabólicas pode ajudar no estabelecimento de novas estratégias terapêuticas. Nesta revisão, são abordados diferentes aspectos da biologia dos dermatófitos, com ênfase na interação dermatófito-hospedeiro e nos mecanismos de resistência a antifúngicos.Cutaneous mycoses are among the most common infections in humans and have become an important public health issue because they cause invasive infections in immunocompromised patients. During the infectious process, dermatophyte-host interactions trigger specific metabolic adaptations that allow the pathogen to adhere to and penetrate the host tissue, scavenge nutrients, and overcome the host defense mechanisms. This metabolic shift and the interplay between metabolism, morphogenesis and stress response are important factors that have been extensively studied in several pathogens. Host cells also respond to the pathogen stimuli by activating intracellular signaling pathways that trigger the immune response against the infectious agent. The comprehension of the molecular aspects of these

  6. The intrinsically disordered structural platform of the plant defence hub protein RPM1-interacting protein 4 provides insights into its mode of action in the host-pathogen interface and evolution of the nitrate-induced domain protein family.

    Science.gov (United States)

    Sun, Xiaolin; Greenwood, David R; Templeton, Matthew D; Libich, David S; McGhie, Tony K; Xue, Bin; Yoon, Minsoo; Cui, Wei; Kirk, Christopher A; Jones, William T; Uversky, Vladimir N; Rikkerink, Erik H A

    2014-09-01

    Arabidopsis thaliana (At) RPM1-interacting protein 4 (RIN4), targeted by many defence-suppressing bacterial type III effectors and monitored by several resistance proteins, regulates plant immune responses to pathogen-associated molecular patterns and type III effectors. Little is known about the overall protein structure of AtRIN4, especially in its unbound form, and the relevance of structure to its diverse biological functions. AtRIN4 contains two nitrate-induced (NOI) domains and is a member of the NOI family. Using experimental and bioinformatic approaches, we demonstrate that the unbound AtRIN4 is intrinsically disordered under physiological conditions. The intrinsically disordered polypeptide chain of AtRIN4 is interspersed with molecular recognition features (MoRFs) and anchor-identified long-binding regions, potentially allowing it to undergo disorder-to-order transitions upon binding to partner(s). A poly-l-proline II structure, often responsible for protein recognition, is also identified in AtRIN4. By performing bioinformatics analyses on RIN4 homologues from different plant species and the NOI proteins from Arabidopsis, we infer the conservation of intrinsic disorder, MoRFs and long-binding regions of AtRIN4 in other plant species and the NOI family. Intrinsic disorder and MoRFs could provide RIN4 proteins with the binding promiscuity and plasticity required to act as hubs in a pivotal position within plant defence signalling cascades. © 2014 FEBS.

  7. Inhibiting host-pathogen interactions using membrane-based nanostructures.

    Science.gov (United States)

    Bricarello, Daniel A; Patel, Mira A; Parikh, Atul N

    2012-06-01

    Virulent strains of bacteria and viruses recognize host cells by their plasma membrane receptors and often exploit the native translocation machinery to invade the cell. A promising therapeutic concept for early interruption of pathogen infection is to subvert this pathogenic trickery using exogenously introduced decoys that present high-affinity mimics of cellular receptors. This review highlights emerging applications of molecularly engineered lipid-bilayer-based nanostructures, namely (i) functionalized liposomes, (ii) supported colloidal bilayers or protocells and (iii) reconstituted lipoproteins, which display functional cellular receptors in optimized conformational and aggregative states. These decoys outcompete host cell receptors by preferentially binding to and neutralizing virulence factors of both bacteria and viruses, thereby promising a new approach to antipathogenic therapy. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Host-pathogen Interactions in Guillain-Barré Syndrome

    NARCIS (Netherlands)

    M.L. Kuijf (Mark)

    2009-01-01

    textabstractGuillain-Barré syndrome (GBS) is a neurological illness in which patients become rapidly paralyzed and require long-term rehabilitation. At present, it is the world’s most frequent cause of acute ascending paralysis in those countries where poliomyelitis has been eradicated (1). GBS is a

  9. Host pathogen interactions in Helicobacter pylori related gastric cancer

    Science.gov (United States)

    Chmiela, Magdalena; Karwowska, Zuzanna; Gonciarz, Weronika; Allushi, Bujana; Stączek, Paweł

    2017-01-01

    Helicobacter pylori (H. pylori), discovered in 1982, is a microaerophilic, spiral-shaped gram-negative bacterium that is able to colonize the human stomach. Nearly half of the world's population is infected by this pathogen. Its ability to induce gastritis, peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma has been confirmed. The susceptibility of an individual to these clinical outcomes is multifactorial and depends on H. pylori virulence, environmental factors, the genetic susceptibility of the host and the reactivity of the host immune system. Despite the host immune response, H. pylori infection can be difficult to eradicate. H. pylori is categorized as a group I carcinogen since this bacterium is responsible for the highest rate of cancer-related deaths worldwide. Early detection of cancer can be lifesaving. The 5-year survival rate for gastric cancer patients diagnosed in the early stages is nearly 90%. Gastric cancer is asymptomatic in the early stages but always progresses over time and begins to cause symptoms when untreated. In 97% of stomach cancer cases, cancer cells metastasize to other organs. H. pylori infection is responsible for nearly 60% of the intestinal-type gastric cancer cases but also influences the development of diffuse gastric cancer. The host genetic susceptibility depends on polymorphisms of genes involved in H. pylori-related inflammation and the cytokine response of gastric epithelial and immune cells. H. pylori strains differ in their ability to induce a deleterious inflammatory response. H. pylori-driven cytokines accelerate the inflammatory response and promote malignancy. Chronic H. pylori infection induces genetic instability in gastric epithelial cells and affects the DNA damage repair systems. Therefore, H. pylori infection should always be considered a pro-cancerous factor. PMID:28321154

  10. Host-pathogen interactions between Francisella tularensis and Drosophila melanogaster

    OpenAIRE

    Vonkavaara, Malin

    2012-01-01

    Francisella tularensis is a highly virulent Gram-negative bacterium causing the zoonotic disease tularemia. Arthropod-borne transmission plays an important role in transferring the disease to humans. F. tularensis induces very low amounts of pro-inflammatory cytokines during infection, due to inhibition of immune signaling pathways and an unusual structure of its lipopolysaccharide (LPS). To date, there is no vaccine available that is approved for public use, although an attenuated live vacci...

  11. Host-pathogen interaction during Streptococcus pneumoniae colonization and infection

    NARCIS (Netherlands)

    D. Bogaert (Debby)

    2004-01-01

    markdownabstract__Abstract__ Streptococcus pneumoniae was discovered by Sternberg and Pasteur in 1880. It took another six years to discover that this microorganism, called the pneumococcus, was the actual cause of bacterial pneumonia . Subsequently, this bacterium has been shown to provoke an

  12. Host-pathogen interactions mediating pain of urinary tract infection.

    Science.gov (United States)

    Rudick, Charles N; Billips, Benjamin K; Pavlov, Vladimir I; Yaggie, Ryan E; Schaeffer, Anthony J; Klumpp, David J

    2010-04-15

    Pelvic pain is a major component of the morbidity associated with urinary tract infection (UTI), yet the molecular mechanisms underlying UTI-induced pain remain unknown. UTI pain mechanisms probably contrast with the clinical condition of asymptomatic bacteriuria (ASB), characterized by significant bacterial loads without lack symptoms. A murine UTI model was used to compare pelvic pain behavior elicited by infection with uropathogenic Escherichia coli strain NU14 and ASB strain 83972. NU14-infected mice exhibited pelvic pain, whereas mice infected with 83972 did not exhibit pain, similar to patients infected with 83972. NU14-induced pain was not dependent on mast cells, not correlated with bacterial colonization or urinary neutrophils. UTI pain was not influenced by expression of type 1 pili, the bacterial adhesive appendages that induce urothelial apoptosis. However, purified NU14 lipopolysaccharide (LPS) induced Toll-like receptor 4 (TLR4)-dependent pain, whereas 83972 LPS induced no pain. Indeed, 83972 LPS attenuated the pain of NU14 infection, suggesting therapeutic potential. These data suggest a novel mechanism of infection-associated pain that is dependent on TLR4 yet independent of inflammation. Clinically, these findings also provide the rational for probiotic therapies that would minimize the symptoms of infection without reliance on empirical therapies that contribute to antimicrobial resistance.

  13. Mutants in the host-pathogen system barley-powdery mildew

    International Nuclear Information System (INIS)

    Joergensen, J.H.

    1989-10-01

    Mutation induction was used to analyse the host/pathogen interaction of barley and Erysiphe graminis. By irradiation or chemical mutagens, a number of similar mutations were induced in the ml-o gene (locus) of barley. The mutants had non-specific and durable resistance, which is rather uncommon. Studies revealed, that in spite of their similarity (the same mutated locus, monogenic recessive inheritance), the mutants were not identical and represent unique sources of disease resistant germ plasm. To study more fundamentally the interference of induced mutations in host/pathogen interactions, barley carrying the dominant resistance gene M1-a 12 was irradiated to mutate this gene. Instead of the expected ''monogenic recessive susceptibility'', several different mutational events inside and outside the locus were found to modify the resistance towards a more or less susceptible reaction. A third interesting approach was to induce mutations in the pathogen and thus create new virulence genes. The result, that no true mutation towards virulence was obtained in extremely large populations, deserves attention and further study to be sure about its implication. 13 refs

  14. Predators indirectly control vector-borne disease: linking predator-prey and host-pathogen models.

    Science.gov (United States)

    Moore, Sean M; Borer, Elizabeth T; Hosseini, Parviez R

    2010-01-06

    Pathogens transmitted by arthropod vectors are common in human populations, agricultural systems and natural communities. Transmission of these vector-borne pathogens depends on the population dynamics of the vector species as well as its interactions with other species within the community. In particular, predation may be sufficient to control pathogen prevalence indirectly via the vector. To examine the indirect effect of predators on vectored-pathogen dynamics, we developed a theoretical model that integrates predator-prey and host-pathogen theory. We used this model to determine whether predation can prevent pathogen persistence or alter the stability of host-pathogen dynamics. We found that, in the absence of predation, pathogen prevalence in the host increases with vector fecundity, whereas predation on the vector causes pathogen prevalence to decline, or even become extinct, with increasing vector fecundity. We also found that predation on a vector may drastically slow the initial spread of a pathogen. The predator can increase host abundance indirectly by reducing or eliminating infection in the host population. These results highlight the importance of studying interactions that, within the greater community, may alter our predictions when studying disease dynamics. From an applied perspective, these results also suggest situations where an introduced predator or the natural enemies of a vector may slow the rate of spread of an emerging vector-borne pathogen.

  15. Determinants of the Sympatric Host-Pathogen Relationship in Tuberculosis

    Science.gov (United States)

    David, Susana; Mateus, A. R. A.; Duarte, Elsa L.; Albuquerque, José; Portugal, Clara; Sancho, Luísa; Lavinha, João; Gonçalves, Guilherme

    2015-01-01

    Major contributions from pathogen genome analysis and host genetics have equated the possibility of Mycobacterium tuberculosis co-evolution with its human host leading to more stable sympatric host–pathogen relationships. However, the attribution to either sympatric or allopatric categories depends on the resolution or grain of genotypic characterization. We explored the influence on the sympatric host-pathogen relationship of clinical (HIV infection and multidrug-resistant tuberculosis [MDRTB]) and demographic (gender and age) factors in regards to the genotypic grain by using spacer oligonucleotide typing (spoligotyping) for classification of M. tuberculosis strains within the Euro-American lineage. We analyzed a total of 547 tuberculosis (TB) cases, from six year consecutive sampling in a setting with high TB-HIV coinfection (32.0%). Of these, 62.0% were caused by major circulating pathogen genotypes. The sympatric relationship was defined according to spoligotype in comparison to the international spoligotype database SpolDB4. While no significant association with Euro-American lineage was observed with any of the factors analyzed, increasing the resolution with spoligotyping evidenced a significant association of MDRTB with sympatric strains, regardless of the HIV status. Furthermore, distribution curves of the prevalence of sympatric and allopatric TB in relation to patients’ age showed an accentuation of the relevance of the age of onset in the allopatric relationship, as reflected in the trimodal distribution. On the contrary, sympatric TB was characterized by the tendency towards a typical (standard) distribution curve. Our results suggest that within the Euro-American lineage a greater degree of genotyping fine-tuning is necessary in modeling the biological processes behind the host-pathogen interplay. Furthermore, prevalence distribution of sympatric TB to age was suggestive of host genetic determinisms driven by more common variants. PMID:26529092

  16. Understanding Speaker-Listener Interaction

    NARCIS (Netherlands)

    Heylen, Dirk K.J.

    2009-01-01

    We provide an eclectic generic framework to understand the back and forth interactions between participants in a conversation highlighting the complexity of the actions that listeners are engaged in. Communicative actions of one participant implicate the “other��? in many ways. In this paper, we try

  17. Phenotypic Variation Is Almost Entirely Independent of the Host-Pathogen Relationship in Clinical Isolates of S. aureus.

    Directory of Open Access Journals (Sweden)

    Adrian D Land

    Full Text Available A key feature of Staphylococcus aureus biology is its ability to switch from an apparently benign colonizer of ~30% of the population to a cutaneous pathogen, to a deadly invasive pathogen. Little is known about the mechanisms driving this transition or the propensity of different S. aureus strains to engender different types of host-pathogen interactions. At the same time, significant weight has been given to the role of specific in vitro phenotypes in S. aureus virulence. Biofilm formation, hemolysis and pigment formation have all been associated with virulence in mice.To determine if there is a correlation between in vitro phenotype and the three types of host-pathogen relationships commonly exhibited by S. aureus in the context of its natural human host, we assayed 300 clinical isolates for phenotypes implicated in virulence including hemolysis, sensitivity to autolysis, and biofilm formation. For comparative purposes, we also assayed phenotype in 9 domesticated S. aureus strains routinely used for analysis of virulence determinants in laboratory settings.Strikingly, the clinical strains exhibited significant phenotypic uniformity in each of the assays evaluated in this study. One exception was a small, but significant, correlation between an increased propensity for biofilm formation and isolation from skin and soft tissue infections (SSTIs. In contrast, we observed a high degree of phenotypic variation between common laboratory strains that exhibit virulence in mouse models. These data suggest the existence of significant evolutionary pressure on the S. aureus genome and highlight a role for host factors as a strong determinant of the host-pathogen relationship. In addition, the high degree of variation between laboratory strains emphasizes the need for caution when applying data obtained in one lab strain to the analysis of another.

  18. Allopatric tuberculosis host-pathogen relationships are associated with greater pulmonary impairment.

    Science.gov (United States)

    Pasipanodya, Jotam G; Moonan, Patrick K; Vecino, Edgar; Miller, Thaddeus L; Fernandez, Michel; Slocum, Philip; Drewyer, Gerry; Weis, Stephen E

    2013-06-01

    Host pathogen relationships can be classified as allopatric, when the pathogens originated from separate, non-overlapping geographic areas from the host; or sympatric, when host and pathogen shared a common ancestral geographic location. It remains unclear if host-pathogen relationships, as defined by phylogenetic lineage, influence clinical outcome. We sought to examine the association between allopatric and sympatric phylogenetic Mycobacterium tuberculosis lineages and pulmonary impairment after tuberculosis (PIAT). Pulmonary function tests were performed on patients 16 years of age and older who had received ≥20 weeks of treatment for culture-confirmed M. tuberculosis complex. Forced Expiratory Volume in 1 min (FEV1) ≥80%, Forced Vital Capacity (FVC) ≥80% and FEV1/FVC >70% of predicted were considered normal. Other results defined pulmonary impairment. Spoligotype and 12-locus mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) were used to assign phylogenetic lineage. PIAT severity was compared between host-pathogen relationships which were defined by geography and ethnic population. We used multivariate logistic regression modeling to calculate adjusted odds ratios (aOR) between phylogenetic lineage and PIAT. Self-reported continental ancestry was correlated with Mycobacterium. tuberculosis lineage (pallopatric host-pathogen relationships and PIAT was 1.8 (95% confidence interval [CI]: 1.1, 2.9) compared to sympatric relationships. Smoking >30 pack-years was also associated with PIAT (aOR: 3.2; 95% CI: 1.5, 7.2) relative to smoking allopatric-host-pathogen relationship were more likely to have PIAT than patients with disease from sympatric-host-pathogen relationship infection. Further study of this association may identify ways that treatment and preventive efforts can be tailored to specific lineages and racial/ethnic populations. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Identifying the Achilles heel of multi-host pathogens: the concept of keystone ‘host’ species illustrated by Mycobacterium ulcerans transmission

    International Nuclear Information System (INIS)

    Roche, Benjamin; Eric Benbow, M; Merritt, Richard; Kimbirauskas, Ryan; McIntosh, Mollie; Small, Pamela L C; Williamson, Heather; Guégan, Jean-François

    2013-01-01

    Pathogens that use multiple host species are an increasing public health issue due to their complex transmission, which makes them difficult to mitigate. Here, we explore the possibility of using networks of ecological interactions among potential host species to identify the particular disease-source species to target to break down transmission of such pathogens. We fit a mathematical model on prevalence data of Mycobacterium ulcerans in western Africa and we show that removing the most abundant taxa for this category of pathogen is not an optimal strategy to decrease the transmission of the mycobacterium within aquatic ecosystems. On the contrary, we reveal that the removal of some taxa, especially Oligochaeta worms, can clearly reduce rates of pathogen transmission, and these should be considered as keystone organisms for its transmission because they lead to a substantial reduction in pathogen prevalence regardless of the network topology. Besides their potential application for the understanding of M. ulcerans ecology, we discuss how networks of species interactions can modulate transmission of multi-host pathogens. (letter)

  20. Modelling the dynamics of an experimental host-pathogen microcosm within a hierarchical Bayesian framework.

    Directory of Open Access Journals (Sweden)

    David Lunn

    Full Text Available The advantages of Bayesian statistical approaches, such as flexibility and the ability to acknowledge uncertainty in all parameters, have made them the prevailing method for analysing the spread of infectious diseases in human or animal populations. We introduce a Bayesian approach to experimental host-pathogen systems that shares these attractive features. Since uncertainty in all parameters is acknowledged, existing information can be accounted for through prior distributions, rather than through fixing some parameter values. The non-linear dynamics, multi-factorial design, multiple measurements of responses over time and sampling error that are typical features of experimental host-pathogen systems can also be naturally incorporated. We analyse the dynamics of the free-living protozoan Paramecium caudatum and its specialist bacterial parasite Holospora undulata. Our analysis provides strong evidence for a saturable infection function, and we were able to reproduce the two waves of infection apparent in the data by separating the initial inoculum from the parasites released after the first cycle of infection. In addition, the parameter estimates from the hierarchical model can be combined to infer variations in the parasite's basic reproductive ratio across experimental groups, enabling us to make predictions about the effect of resources and host genotype on the ability of the parasite to spread. Even though the high level of variability between replicates limited the resolution of the results, this Bayesian framework has strong potential to be used more widely in experimental ecology.

  1. Toxoplasmosis and Polygenic Disease Susceptibility Genes: Extensive Toxoplasma gondii Host/Pathogen Interactome Enrichment in Nine Psychiatric or Neurological Disorders

    Directory of Open Access Journals (Sweden)

    C. J. Carter

    2013-01-01

    Full Text Available Toxoplasma gondii is not only implicated in schizophrenia and related disorders, but also in Alzheimer's or Parkinson's disease, cancer, cardiac myopathies, and autoimmune disorders. During its life cycle, the pathogen interacts with ~3000 host genes or proteins. Susceptibility genes for multiple sclerosis, Alzheimer's disease, schizophrenia, bipolar disorder, depression, childhood obesity, Parkinson's disease, attention deficit hyperactivity disorder (multiple sclerosis, and autism (, but not anorexia or chronic fatigue are highly enriched in the human arm of this interactome and 18 (ADHD to 33% (MS of the susceptibility genes relate to it. The signalling pathways involved in the susceptibility gene/interactome overlaps are relatively specific and relevant to each disease suggesting a means whereby susceptibility genes could orient the attentions of a single pathogen towards disruption of the specific pathways that together contribute (positively or negatively to the endophenotypes of different diseases. Conditional protein knockdown, orchestrated by T. gondii proteins or antibodies binding to those of the host (pathogen derived autoimmunity and metabolite exchange, may contribute to this disruption. Susceptibility genes may thus be related to the causes and influencers of disease, rather than (and as well as to the disease itself.

  2. Dynamics and profiles of a diffusive host-pathogen system with distinct dispersal rates

    Science.gov (United States)

    Wu, Yixiang; Zou, Xingfu

    2018-04-01

    In this paper, we investigate a diffusive host-pathogen model with heterogeneous parameters and distinct dispersal rates for the susceptible and infected hosts. We first prove that the solution of the model exists globally and the model system possesses a global attractor. We then identify the basic reproduction number R0 for the model and prove its threshold role: if R0 ≤ 1, the disease free equilibrium is globally asymptotically stable; if R0 > 1, the solution of the model is uniformly persistent and there exists a positive (pathogen persistent) steady state. Finally, we study the asymptotic profiles of the positive steady state as the dispersal rate of the susceptible or infected hosts approaches zero. Our result suggests that the infected hosts concentrate at certain points which can be characterized as the pathogen's most favoured sites when the mobility of the infected host is limited.

  3. Advances in understanding river-groundwater interactions

    Science.gov (United States)

    Brunner, Philip; Therrien, René; Renard, Philippe; Simmons, Craig T.; Franssen, Harrie-Jan Hendricks

    2017-09-01

    River-groundwater interactions are at the core of a wide range of major contemporary challenges, including the provision of high-quality drinking water in sufficient quantities, the loss of biodiversity in river ecosystems, or the management of environmental flow regimes. This paper reviews state of the art approaches in characterizing and modeling river and groundwater interactions. Our review covers a wide range of approaches, including remote sensing to characterize the streambed, emerging methods to measure exchange fluxes between rivers and groundwater, and developments in several disciplines relevant to the river-groundwater interface. We discuss approaches for automated calibration, and real-time modeling, which improve the simulation and understanding of river-groundwater interactions. Although the integration of these various approaches and disciplines is advancing, major research gaps remain to be filled to allow more complete and quantitative integration across disciplines. New possibilities for generating realistic distributions of streambed properties, in combination with more data and novel data types, have great potential to improve our understanding and predictive capabilities for river-groundwater systems, especially in combination with the integrated simulation of the river and groundwater flow as well as calibration methods. Understanding the implications of different data types and resolution, the development of highly instrumented field sites, ongoing model development, and the ultimate integration of models and data are important future research areas. These developments are required to expand our current understanding to do justice to the complexity of natural systems.

  4. Review Essay: Understanding in Professional Interactions

    Directory of Open Access Journals (Sweden)

    Rainer Schützeichel

    2012-07-01

    Full Text Available "Professions" are work collaborations in which representatives of certain vocations address the life problems of "laypersons." In such relationships, adequate communication between representatives of the profession and laypersons is crucial in addressing their individual problems. Accordingly, "understanding," as well as interactional documentation of this understanding, is of considerable importance. The authors of the present volume, "Understanding in Professional Spheres of Activity,"  address the documentation of this understanding in certain professional spheres. They examine the requirements for the documentation of such understanding and the forms of documentation used in the fields of doctor-patient communication, counseling communication, and organizational collaboration on a movie set. Conversation analytic as well as ethnographically complemented studies draw further attention to an examination of the interactional level in its socio-structural context, and to that end the study employs a combination of conversational linguistics and sociological research. This contribution is therefore important not only in terms of linguistics but also sociologically. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1203142

  5. Penicillium expansum (compatible) and Penicillium digitatum (non-host) pathogen infection differentially alter ethylene biosynthesis in apple fruit.

    Science.gov (United States)

    Vilanova, Laura; Vall-Llaura, Núria; Torres, Rosario; Usall, Josep; Teixidó, Neus; Larrigaudière, Christian; Giné-Bordonaba, Jordi

    2017-11-01

    The role of ethylene on inducing plant resistance or susceptibility to certain fungal pathogens clearly depends on the plant pathogen interaction with little or no-information available focused on the apple-Penicillium interaction. Taken advantage that Penicillium expansum is the compatible pathogen and P. digitatum is the non-host of apples, the present study aimed at deciphering how each Penicillium spp. could interfere in the fruit ethylene biosynthesis at the biochemical and molecular level. The infection capacity and different aspects related to the ethylene biosynthesis were conducted at different times post-inoculation. The results show that the fruit ethylene biosynthesis was differently altered during the P. expansum infection than in response to other biotic (non-host pathogen P. digitatum) or abiotic stresses (wounding). The first symptoms of the disease due to P. expansum were visible before the initiation of the fruit ethylene climacteric burst. Indeed, the ethylene climacteric burst was reduced in response to P. expansum concomitant to an important induction of MdACO3 gene expression and an inhibition (ca. 3-fold) and overexpression (ca. 2-fold) of ACO (1-Aminocyclopropane-1-carboxylic acid oxidase) and ACS (1-Aminocyclopropane-1-carboxylic acid synthase) enzyme activities, indicating a putative role of MdACO3 in the P. expansum-apple interaction which may, in turn, be related to System-1 ethylene biosynthesis. System-1 is auto-inhibited by ethylene and is characteristic of non-climateric or pre-climacteric fruit. Accordingly, we hypothesise that P. expansum may 'manipulate' the endogenous ethylene biosynthesis in apples, leading to the circumvention or suppression of effective defences hence facilitating its colonization. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. Understanding and modelling Man-Machine Interaction

    International Nuclear Information System (INIS)

    Cacciabue, P.C.

    1991-01-01

    This paper gives an overview of the current state of the art in man machine systems interaction studies, focusing on the problems derived from highly automated working environments and the role of humans in the control loop. In particular, it is argued that there is a need for sound approaches to design and analysis of Man-Machine Interaction (MMI), which stem from the contribution of three expertises in interfacing domains, namely engineering, computer science and psychology: engineering for understanding and modelling plants and their material and energy conservation principles; psychology for understanding and modelling humans and their cognitive behaviours; computer science for converting models in sound simulations running in appropriate computer architectures. (author)

  7. Understanding and modelling man-machine interaction

    International Nuclear Information System (INIS)

    Cacciabue, P.C.

    1996-01-01

    This paper gives an overview of the current state of the art in man-machine system interaction studies, focusing on the problems derived from highly automated working environments and the role of humans in the control loop. In particular, it is argued that there is a need for sound approaches to the design and analysis of man-machine interaction (MMI), which stem from the contribution of three expertises in interfacing domains, namely engineering, computer science and psychology: engineering for understanding and modelling plants and their material and energy conservation principles; psychology for understanding and modelling humans an their cognitive behaviours; computer science for converting models in sound simulations running in appropriate computer architectures. (orig.)

  8. Host-Pathogen Interactions: I. A Correlation Between α-Galactosidase Production and Virulence 1

    Science.gov (United States)

    English, Patricia D.; Albersheim, Peter

    1969-01-01

    Resistance or susceptibility of Red Kidney, Pinto and Small White beans (Phaseolus vulgaris) to the alpha, beta, and gamma strains of Colletotrichum lindemuthianum was either confirmed or established. These fungal strains secrete α-galactosidase, β-galactosidase and β-xylosidase when grown on cell walls isolated from the hypocotyls of any of the above bean varieties. These enzymes effectively degrade cell walls isolated from susceptible 5-day old hypocotyls but degrade only slightly the walls isolated from resistant 18-day old hypocotyls. The amounts of the β-galactosidase and β-xylosidase secreted by the 3 fungal strains are relatively low and are approximately equivalent. The secretion of these 2 enzymes is not dependent upon the bean variety from which the hypocotyl cell walls used as a carbon source were isolated. However, the fungal strains secrete greater amounts of α-galactosidase when grown on hypocotyl cell walls isolated from susceptible plants than when grown on walls from resistant plants. Virulent isolates of the fungus, when grown on hypocotyl cell walls isolated from a susceptible plant, secrete more α-galactosidase than do attenuated (avirulent) isolates of the same fungal strain grown under the same conditions. The α-galactosidase secreted by each of the fungal strains is capable of removing galactose from the hypocotyl cell walls of each bean variety tested. Galactose is removed from the cell walls of each variety at the same rate regardless of whether the cell walls were isolated from a susceptible or resistant plant. PMID:16657049

  9. Effects of urbanization on host-pathogen interactions, using Yersinia in house sparrows as a model

    Science.gov (United States)

    Strubbe, Diederik; Teyssier, Aimeric; Salleh Hudin, Noraine; Van den Abeele, Anne-Marie; Cox, Ivo; Haesendonck, Roel; Delmée, Michel; Haesebrouck, Freddy; Pasmans, Frank; Lens, Luc; Martel, An

    2017-01-01

    Urbanization strongly affects biodiversity, altering natural communities and often leading to a reduced species richness. Yet, despite its increasingly recognized importance, how urbanization impacts on the health of individual animals, wildlife populations and on disease ecology remains poorly understood. To test whether, and how, urbanization-driven ecosystem alterations influence pathogen dynamics and avian health, we use house sparrows (Passer domesticus) and Yersinia spp. (pathogenic for passerines) as a case study. Sparrows are granivorous urban exploiters, whose western European populations have declined over the past decades, especially in highly urbanized areas. We sampled 329 house sparrows originating from 36 populations along an urbanization gradient across Flanders (Belgium), and used isolation combined with ‘matrix-assisted laser desorption ionization- time of flight mass spectrometry’ (MALDI-TOF MS) and PCR methods for detecting the presence of different Yersinia species. Yersinia spp. were recovered from 57.43% of the sampled house sparrows, of which 4.06%, 53.30% and 69.54% were identified as Y. pseudotuberculosis, Y. enterocolitica and other Yersinia species, respectively. Presence of Yersinia was related to the degree of urbanization, average daily temperatures and the community of granivorous birds present at sparrow capture locations. Body condition of suburban house sparrows was found to be higher compared to urban and rural house sparrows, but no relationships between sparrows’ body condition and presence of Yersinia spp. were found. We conclude that two determinants of pathogen infection dynamics, body condition and pathogen occurrence, vary along an urbanization gradient, potentially mediating the impact of urbanization on avian health. PMID:29281672

  10. Novel Burkholderia mallei Virulence Factors Linked to Specific Host-Pathogen Protein Interactions

    Science.gov (United States)

    2013-06-23

    equine hosts. Thus, the genes retained in B. mallei share a high sequence similarity to genes common to B. pseudomallei (3), and many virulence...oppor- tunistic infections in mammalian hosts. Even for the equine - adapted and, thus, more genetically constrained, B. mallei pathogen, we cannot...BioDrugs: Clin. Immunotherapeut., Biopharmaceut. Gene Therapy 17, 413–424 88. Anderson, D. M., and Frank, D. W. (2012) Five mechanisms of manipula

  11. Host-pathogen interactions in Lyme disease and their application in diagnostics

    NARCIS (Netherlands)

    Burgel, Nathalie Daniëlle van

    2013-01-01

    B. burgdorferi has a wide variety of strategies to hide from the host immune system. Complement regulatory binding proteins have been described for almost all complement resistant B. burgdorferi sl, except for the complement resistant B. bavariensis, one of the species that is known to frequently

  12. Host-Pathogen Interactions : XXXII. A Fungal Glucan Preparation Protects Nicotianae against Infection by Viruses.

    Science.gov (United States)

    Kopp, M; Rouster, J; Fritig, B; Darvill, A; Albersheim, P

    1989-05-01

    A glucan preparation obtained from the mycelial walls of the fungus Phytophthora megasperma f.sp. glycinea and known as an elicitor of phytoalexins in soybean was shown to be a very efficient inducer of resistance against viruses in tobacco. The glucan preparation protected against mechanically transmitted viral infections on the upper and lower leaf surfaces. Whether the glucan preparation was applied by injection, inoculation, or spraying, it protected the plants if applied before, at the same time as, or not later than 8 hours after virus inoculation. At concentrations ranging from 0.1 to 10 micrograms per milliliter, the glucan preparation induced protection ranging from 50 to 100% against both symptom production (necrotic local lesions, necrotic rings, or systemic mosaic) and virus accumulation in all Nicotiana-virus combinations examined. However, no significant protection against some of the same viruses was observed in bean or turnip. The host plants successfully protected included N. tabacum (9 different cultivars), N. sylvestris, N. glutinosa, and N. clevelandii. The viruses belonged to several taxonomic groups including tobacco mosaic virus, alfalfa mosaic virus, and tomato black ring virus. The glucan preparation did not act directly on the virus and did not interfere with virus disassembly; rather, it appeared to induce changes in the host plant that prevented infections from being initiated or recently established infections from enlarging. The induced resistance does not depend on induction of pathogenesis-related proteins, the phenylpropanoid pathway, lignin-like substances, or callose-like materials. We believe the induced resistance results from a mechanism that has yet to be described.

  13. Bacterial Serine/Threonine Protein Kinases in Host-Pathogen Interactions*

    Science.gov (United States)

    Canova, Marc J.; Molle, Virginie

    2014-01-01

    In bacterial pathogenesis, monitoring and adapting to the dynamically changing environment in the host and an ability to disrupt host immune responses are critical. The virulence determinants of pathogenic bacteria include the sensor/signaling proteins of the serine/threonine protein kinase (STPK) family that have a dual role of sensing the environment and subverting specific host defense processes. STPKs can sense a wide range of signals and coordinate multiple cellular processes to mount an appropriate response. Here, we review some of the well studied bacterial STPKs that are essential virulence factors and that modify global host responses during infection. PMID:24554701

  14. Bacterial serine/threonine protein kinases in host-pathogen interactions.

    Science.gov (United States)

    Canova, Marc J; Molle, Virginie

    2014-04-04

    In bacterial pathogenesis, monitoring and adapting to the dynamically changing environment in the host and an ability to disrupt host immune responses are critical. The virulence determinants of pathogenic bacteria include the sensor/signaling proteins of the serine/threonine protein kinase (STPK) family that have a dual role of sensing the environment and subverting specific host defense processes. STPKs can sense a wide range of signals and coordinate multiple cellular processes to mount an appropriate response. Here, we review some of the well studied bacterial STPKs that are essential virulence factors and that modify global host responses during infection.

  15. Host-Pathogen Coupled Networks: Model for Bacillus Anthracis Interaction with Host Macrophages

    Science.gov (United States)

    2015-09-01

    circles). Data points represent absorbance values at 570 nm following the MTT assay. Fitted values are KX2 = 10-6 nM-1s-1 and R = 0.21 nM s-1. (B...represent absorbance values at 570 nm following MTT assay. Here cell “death”, as indicated by the diminution of the signal (corrected for residual...cleaves the N-terminus of MAPKKs and induces tyrosine /threonine phosphorylation of MAPKs in cultured macrophages. Biochem Biophys Res Commun. 248(3):706

  16. Host-pathogen interactions and genome evolution in two generalist and specialist microsporidian pathogens of mosquitoes

    Science.gov (United States)

    The adaptation of two distantly related microsporidia to their mosquito hosts was investigated. Edhazardia aedis is a specialist pathogen that infects Aedes aegypti, the main vector of dengue and yellow fever arboviruses. Vavraia culicis is a generalist pathogen of several insects including Anophele...

  17. Understanding Radionuclide Interactions with Layered Materials

    Science.gov (United States)

    Wang, Y.

    2015-12-01

    Layered materials play an important role in nuclear waste management and environmental cleanup. Better understanding of radionuclide interactions with those materials is critical for engineering high-performance materials for various applications. This presentation will provide an overview on radionuclide interactions with two general categories of layered materials - cationic clays and anionic clays - from a perspective of nanopore confinement. Nanopores are widely present in layered materials, either as the interlayers or as inter-particle space. Nanopore confinement can significantly modify chemical reactions in those materials. This effect may cause the preferential enrichment of radionuclides in nanopores and therefore directly impact the mobility of the radionuclides. This effect also implies that conventional sorption measurements using disaggregated samples may not represent chemical conditions in actual systems. The control of material structures on ion exchange, surface complexation, and diffusion in layered materials will be systematically examined, and the related modeling approaches will be discussed. This work was performed at Sandia National Laboratories, which is a multiprogram laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the DOE under contract DE-AC04-94AL8500.

  18. Understanding the Properties of Interactive Televised Characters

    Science.gov (United States)

    Claxton, Laura J.; Ponto, Katelyn C.

    2013-01-01

    Children's television programming frequently uses interactive characters that appear to directly engage the viewers. These characters encourage children to answer questions and perform actions to help the characters solve problems in the televised world. Children readily engage in these interactions; however, it is unclear why they do so. To…

  19. Understanding children's science identity through classroom interactions

    Science.gov (United States)

    Kim, Mijung

    2018-01-01

    Research shows that various stereotypes about science and science learning, such as science being filled with hard and dry content, laboratory experiments, and male-dominated work environments, have resulted in feelings of distance from science in students' minds. This study explores children's experiences of science learning and science identity. It asks how children conceive of doing science like scientists and how they develop views of science beyond the stereotypes. This study employs positioning theory to examine how children and their teacher position themselves in science learning contexts and develop science identity through classroom interactions. Fifteen students in grades 4-6 science classrooms in Western Canada participated in this study. Classroom activities and interactions were videotaped, transcribed, and analysed to examine how the teacher and students position each other as scientists in the classroom. A descriptive explanatory case analysis showed how the teacher's positioning acted to develop students' science identity with responsibilities of knowledge seeking, perseverance, and excitement about science.

  20. Our interests in protein-protein interactions

    Indian Academy of Sciences (India)

    protein interactions. Evolution of P-P partnerships. Evolution of P-P structures. Evolutionary dynamics of P-P interactions. Dynamics of P-P interaction network. Host-pathogen interactions. CryoEM mapping of gigantic protein assemblies.

  1. Foreign Body Infection Models to Study Host-Pathogen Response and Antimicrobial Tolerance of Bacterial Biofilm

    Directory of Open Access Journals (Sweden)

    Justyna Nowakowska

    2014-08-01

    Full Text Available The number of implanted medical devices is steadily increasing and has become an effective intervention improving life quality, but still carries the risk of infection. These infections are mainly caused by biofilm-forming staphylococci that are difficult to treat due to the decreased susceptibility to both antibiotics and host defense mechanisms. To understand the particular pathogenesis and treatment tolerance of implant-associated infection (IAI animal models that closely resemble human disease are needed. Applications of the tissue cage and catheter abscess foreign body infection models in the mouse will be discussed herein. Both models allow the investigation of biofilm and virulence of various bacterial species and a comprehensive insight into the host response at the same time. They have also been proven to serve as very suitable tools to study the anti-adhesive and anti-infective efficacy of different biomaterial coatings. The tissue cage model can additionally be used to determine pharmacokinetics, efficacy and cytotoxicity of antimicrobial compounds as the tissue cage fluid can be aspirated repeatedly without the need to sacrifice the animal. Moreover, with the advance in innovative imaging systems in rodents, these models may offer new diagnostic measures of infection. In summary, animal foreign body infection models are important tools in the development of new antimicrobials against IAI and can help to elucidate the complex interactions between bacteria, the host immune system, and prosthetic materials.

  2. A Multi-Omic View of Host-Pathogen-Commensal Interplay in Salmonella-Mediated Intestinal Infection

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Brooke LD; Li, Jie; Sanford, James A.; Kim, Young-Mo; Kronewitter, Scott R.; Jones, Marcus B.; Peterson, Christine; Peterson, Scott N.; Frank, Bryan C.; Purvine, Samuel O.; Brown, Joseph N.; Metz, Thomas O.; Smith, Richard D.; Heffron, Fred; Adkins, Joshua N.

    2013-06-26

    The potential for commensal microorganisms indigenous to a host (the ‘microbiome’ or ‘microbiota’) to alter infection outcome by influencing host-pathogen interplay is largely unknown. We used a multi-omics “systems” approach, incorporating proteomics, metabolomics, glycomics, and metagenomics, to explore the molecular interplay between the murine host, the pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium), and commensal gut microorganisms during intestinal infection with S. Typhimurium. We find proteomic evidence that S. Typhimurium thrives within the infected 129/SvJ mouse gut without antibiotic pre-treatment, inducing inflammation and disrupting the intestinal microbiome (e.g., suppressing Bacteroidetes and Firmicutes while promoting growth of Salmonella and Enterococcus). Alteration of the host microbiome population structure was highly correlated with gut environmental changes, including the accumulation of metabolites normally consumed by commensal microbiota. Finally, the less characterized phase of S. Typhimurium’s lifecycle was investigated, and both proteomic and glycomic evidence suggests S. Typhimurium may take advantage of increased fucose moieties to metabolize fucose while growing in the gut. The application of multiple omics measurements to Salmonella-induced intestinal inflammation provides insights into complex molecular strategies employed during pathogenesis between host, pathogen, and the microbiome.

  3. Multiple-host pathogens in domestic hunting dogs in Nicaragua's Bosawás Biosphere Reserve.

    Science.gov (United States)

    Fiorello, Christine V; Straub, Mary H; Schwartz, Laura M; Liu, James; Campbell, Amanda; Kownacki, Alexa K; Foley, Janet E

    2017-03-01

    Nicaragua's Bosawás Biosphere Reserve is a vast forested area inhabited largely by indigenous Mayangna and Miskitu people. Most Bosawás residents rely on subsistence hunting and swidden agriculture, and hunting dogs are important for finding and securing wild game. We investigated the health of hunting dogs in three communities differing in location, size, and economy. Dogs in all communities were nutritionally compromised and experienced a heavy burden of disease. Seroprevalence of canine distemper, canine parvovirus, Rickettsia rickettsii, and Leptospira spp. exceeded 50% of dogs. At least one dog was actively shedding leptospires in urine, and many dogs were anemic and/or dehydrated. These dogs interact with wildlife in the forest and humans and domestic livestock in the communities, and may therefore serve as sources of zoonotic and wildlife diseases. Bosawás represents one of the largest intact tracts of habitat for jaguars (Panthera onca) in Central America, and given that these communities are located within the forest, jaguars may be at risk from disease spillover from hunting dogs. Dog owners reported that four of 49 dogs had been attacked and killed by jaguars in the past year, and that retaliatory killing of jaguars was sometimes practiced. Disease spillover from dogs to wildlife could occur both in the course of dogs' hunting activities as well as during jaguar attacks. A better understanding of dog depredation by jaguars, pathogen exposure in jaguars, and a management strategy for the hunting dog population, are urgently needed to mitigate these dual threats to jaguars, improve the lives of hunting dogs, and safeguard the health of their owners. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Understanding cyanobacteria-zooplankton interactions in a more eutrophic world

    NARCIS (Netherlands)

    Ger, K.A.; Hansson, L.; Lurling, M.F.L.L.W.

    2014-01-01

    1.We review and update recent observations of cyanobacteria–zooplankton interactions, identify theoretical and methodological limitations and evaluate approaches necessary for understanding the effects of increasing cyanobacterial blooms on plankton dynamics. 2.The emphasis on oversimplified studies

  5. Biochemical response and host-pathogen relation of stalk rot fungi ...

    African Journals Online (AJOL)

    Stalk rot is a destructive disease in maize caused by Fusarium and Macrophomina species. A study was carried out to understand the mode of infection, host biochemical response and comparison of inoculation techniques in Fusarium verticillioides and Macrophomina phaseolina in maize. In seed inoculation experiment, ...

  6. Concurrent host-pathogen gene expression in the lungs of pigs challenged with Actinobacillus pleuropneumoniae

    DEFF Research Database (Denmark)

    Brogaard, Louise; Schou, Kirstine Klitgaard; Heegaard, Peter M. H.

    2015-01-01

    Background: Actinobacillus pleuropneumoniae causes pleuropneumonia in pigs, a disease which is associated with high morbidity and mortality, as well as impaired animal welfare. To obtain in-depth understanding of this infection, the interplay between virulence factors of the pathogen and defense ...

  7. Hessian-based quantitative image analysis of host-pathogen confrontation assays.

    Science.gov (United States)

    Cseresnyes, Zoltan; Kraibooj, Kaswara; Figge, Marc Thilo

    2018-03-01

    Host-fungus interactions have gained a lot of interest in the past few decades, mainly due to an increasing number of fungal infections that are often associated with a high mortality rate in the absence of effective therapies. These interactions can be studied at the genetic level or at the functional level via imaging. Here, we introduce a new image processing method that quantifies the interaction between host cells and fungal invaders, for example, alveolar macrophages and the conidia of Aspergillus fumigatus. The new technique relies on the information content of transmitted light bright field microscopy images, utilizing the Hessian matrix eigenvalues to distinguish between unstained macrophages and the background, as well as between macrophages and fungal conidia. The performance of the new algorithm was measured by comparing the results of our method with that of an alternative approach that was based on fluorescence images from the same dataset. The comparison shows that the new algorithm performs very similarly to the fluorescence-based version. Consequently, the new algorithm is able to segment and characterize unlabeled cells, thus reducing the time and expense that would be spent on the fluorescent labeling in preparation for phagocytosis assays. By extending the proposed method to the label-free segmentation of fungal conidia, we will be able to reduce the need for fluorescence-based imaging even further. Our approach should thus help to minimize the possible side effects of fluorescence labeling on biological functions. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

  8. Increasing process understanding by analyzing complex interactions in experimental data

    DEFF Research Database (Denmark)

    Naelapaa, Kaisa; Allesø, Morten; Kristensen, Henning Gjelstrup

    2009-01-01

    understanding of a coating process. It was possible to model the response, that is, the amount of drug released, using both mentioned techniques. However, the ANOVAmodel was difficult to interpret as several interactions between process parameters existed. In contrast to ANOVA, GEMANOVA is especially suited...... for modeling complex interactions and making easily understandable models of these. GEMANOVA modeling allowed a simple visualization of the entire experimental space. Furthermore, information was obtained on how relative changes in the settings of process parameters influence the film quality and thereby drug......There is a recognized need for new approaches to understand unit operations with pharmaceutical relevance. A method for analyzing complex interactions in experimental data is introduced. Higher-order interactions do exist between process parameters, which complicate the interpretation...

  9. Development of bioassay for pathogenecity testing of Ureaplasma urealyticum as part of host-pathogen communication

    Directory of Open Access Journals (Sweden)

    Purnomo Soeharso

    2005-12-01

    Full Text Available Bioassay of Ureaplasma urealyticum is necessary for detection as well as determination of pathogenic factors in order to understand the pathogenesis of diseases associate with ureaplasma infection. Cultivation and verification of ureaplasma is the first step of this study in the purpose of discovering sensitive method for ureaplasma detection. Cultivation of ureaplasma either in liquid or in solid media are able to detect the existence of ureaplasma in samples analyzed. However, application of PCR using specific primers to be compatible with urease gene (ure would confirm the presence of ureaplasma. The pathogenicity of ureaplasma is potentially monitored using reporter gene as a marker for gene expression. IceC was chosen as reporter gene for ureaplasma pathogenic determination as the gene has great sensitivity, easily detectable and quantitated in simple method of ice nucleation assay. Transposon 916 (Tn916 was selected as a vector for iceC gene to transform ureaplasma. The application of recombinant Tn916-iceC which is considered as pUI, allow detection of ureaplasma activities when transform ureaplasma is tested by ice nucleation assay. It was expected that ureaplasma transformation is the manifestation of mutagenesis which interfere genes responsible for bacterial pathogenicity, in order pathogenesis of bacterial infection to be analyzed accurately. IgA1 protease is considered to be an important factor for ureaplasma pathogenicity as the enzyme is required for successful colonization. Identification of iga gene and  determination of IgA1 protease activity are important for understanding the pathogenesis of ureaplasma infection. Putative iga gene of Mycoplasma genitalium was used as a reference to identify the presence of iga nucleotide sequence in U. urealyticum. Convincing evidence were obtained after PCR amplification of ureaplasma DNA using primers designed to be compatible with putative iga gene of M. genitalium followed by the

  10. Identification of powdery mildew resistance genes in Polish common oat (Avena sativa L. cultivars using host-pathogen tests

    Directory of Open Access Journals (Sweden)

    Sylwia Okoń

    2012-10-01

    Full Text Available The aim of the present study was to characterize and identify powdery mildew resistance genes in Polish common oat cultivars using host-pathogen tests. A differential set of six Blumeria graminis f.sp. avenae isolates virulent or avirulent to four cultivars and one line that has known resistance to powdery mildew were used. Among the investigated cultivars, only four of them (13.3% had resistance patterns similar to genotypes belonging to the differential set. The resistance of OMR group 1 was found in the cultivar ‘Dragon’, while that of OMR2 in the cultivar ‘Skrzat’. The cultivars ‘Deresz’ and ‘Hetman’ showed a resistance pattern that corresponded with OMR group 3. The resistance corresponding to OMR4 was not found, which suggests that until now this gene has not been used in Polish oat breeding programmes. The cultivar ‘Canyon’ had a different pat- tern of resistance than the genotypes that have already known OMR genes, which indicates that the resistance of this cultivar is determined by a new gene or a combination of known genes.

  11. Correlative cryo-fluorescence and cryo-scanning electron microscopy as a straightforward tool to study host-pathogen interactions

    Czech Academy of Sciences Publication Activity Database

    Strnad, Martin; Elsterová, Jana; Schrenková, Jana; Vancová, Marie; Rego, Ryan O. M.; Grubhoffer, Libor; Nebesářová, Jana

    2015-01-01

    Roč. 5, DEC 10 2015 (2015), s. 18029 ISSN 2045-2322 R&D Projects: GA TA ČR(CZ) TE01020118; GA ČR GAP502/11/2116 EU Projects: European Commission(XE) 278976; European Commission(XE) 602272 Institutional support: RVO:60077344 Keywords : Borrelia burgdorferi * cryoelectron tomography * lyme disease Subject RIV: EE - Microbiology, Virology Impact factor: 5.228, year: 2015

  12. Development of a transformation system for Mycosphaerella pathogens of banana: a tool for the study of host/pathogen interactions.

    Science.gov (United States)

    Balint-Kurti, P J; May, G D; Churchill, A C

    2001-02-05

    A genetic transformation system has been developed for three Mycosphaerella pathogens of banana and plantain (Musa spp.). Mycosphaerella fijiensis and Mycosphaerella musicola, the causal agents of black and yellow Sigatoka, respectively, and Mycosphaerella eumusae, which causes Septoria leaf spot of banana, were transformed with a construct carrying a synthetic gene encoding green fluorescent protein (GFP). Most single-spored transformants that expressed GFP constitutively were mitotically stable in the absence of selection for hygromycin B resistance. Transformants of all three species were pathogenic on the susceptible banana cultivar Grand Nain, and growth in planta was comparable to wild-type strains. GFP expression by transformants allowed us to observe extensive fungal growth within leaf tissue that eventually turned necrotic, at which point the fungi grew saprophytically on the dead tissue. Leaf chlorosis and necrosis were often observed in advance of saprophytic growth of the mycelium on necrotic tissue, which supports previous reports suggesting secretion of a phytotoxin.

  13. A 6-Nucleotide Regulatory Motif within the AbcR Small RNAs of Brucella abortus Mediates Host-Pathogen Interactions.

    Science.gov (United States)

    Sheehan, Lauren M; Caswell, Clayton C

    2017-06-06

    In Brucella abortus , two small RNAs (sRNAs), AbcR1 and AbcR2, are responsible for regulating transcripts encoding ABC-type transport systems. AbcR1 and AbcR2 are required for Brucella virulence, as a double chromosomal deletion of both sRNAs results in attenuation in mice. Although these sRNAs are responsible for targeting transcripts for degradation, the mechanism utilized by the AbcR sRNAs to regulate mRNA in Brucella has not been described. Here, two motifs (M1 and M2) were identified in AbcR1 and AbcR2, and complementary motif sequences were defined in AbcR-regulated transcripts. Site-directed mutagenesis of M1 or M2 or of both M1 and M2 in the sRNAs revealed transcripts to be targeted by one or both motifs. Electrophoretic mobility shift assays revealed direct, concentration-dependent binding of both AbcR sRNAs to a target mRNA sequence. These experiments genetically and biochemically characterized two indispensable motifs within the AbcR sRNAs that bind to and regulate transcripts. Additionally, cellular and animal models of infection demonstrated that only M2 in the AbcR sRNAs is required for Brucella virulence. Furthermore, one of the M2-regulated targets, BAB2_0612, was found to be critical for the virulence of B. abortus in a mouse model of infection. Although these sRNAs are highly conserved among Alphaproteobacteria , the present report displays how gene regulation mediated by the AbcR sRNAs has diverged to meet the intricate regulatory requirements of each particular organism and its unique biological niche. IMPORTANCE Small RNAs (sRNAs) are important components of bacterial regulation, allowing organisms to quickly adapt to changes in their environments. The AbcR sRNAs are highly conserved throughout the Alphaproteobacteria and negatively regulate myriad transcripts, many encoding ABC-type transport systems. In Brucella abortus , AbcR1 and AbcR2 are functionally redundant, as only a double abcR1 abcR2 ( abcR1 / 2 ) deletion results in attenuation in vitro and in vivo In the present study, we confirmed that the AbcR sRNAs have redundant regulatory functions and defined two six-nucleotide motifs, M1 and M2, that the AbcR sRNAs utilize to control gene expression. Importantly, only M2 was linked to B. abortus virulence. Further investigation of M2-regulated targets identified BAB2_0612 as critical for colonization of B. abortus in mice, highlighting the significance of AbcR M2-regulated transcripts for Brucella infection. Overall, our findings define the molecular mechanism of the virulence-associated AbcR system in the pathogenic bacterium B. abortus . Copyright © 2017 Sheehan and Caswell.

  14. Characterization of surface proteins and exosomes and their role in host:pathogen and parasite:parasite interactions

    OpenAIRE

    Twu, Olivia

    2014-01-01

    Trichomonas vaginalis, an extracellular protozoan parasite, is the causative agent of the most common, non-viral sexually transmitted infection. Infection is often asymptomatic, but is associated with long-term effects such as premature labor, low-birth weight babies, cervical cancer, prostate cancer, and increased risk of HIV infection. In spite of its prevalence and medical importance, the pathogenesis of T. vaginalis is poorly understood. It is known that adherence to epithelial cells is v...

  15. Proteome data from a host-pathogen interaction study with Staphylococcus aureus and human lung epithelial cells

    Directory of Open Access Journals (Sweden)

    Kristin Surmann

    2016-06-01

    Full Text Available To simultaneously obtain proteome data of host and pathogen from an internalization experiment, human alveolar epithelial A549 cells were infected with Staphylococcus aureus HG001 which carried a plasmid (pMV158GFP encoding a continuously expressed green fluorescent protein (GFP. Samples were taken hourly between 1.5 h and 6.5 h post infection. By fluorescence activated cell sorting GFP-expressing bacteria could be enriched from host cell debris, but also infected host cells could be separated from those which did not carry bacteria after contact (exposed. Additionally, proteome data of A549 cells which were not exposed to S. aureus but underwent the same sample processing steps are provided as a control. Time-resolved changes in bacterial protein abundance were quantified in a label-free approach. Proteome adaptations of host cells were monitored by comparative analysis to a stable isotope labeled cell culture (SILAC standard. Proteins were extracted from the cells, digested proteolytically, measured by nanoLC–MS/MS, and subsequently identified by database search and then quantified. The data presented here are related to a previously published research article describing the interplay of S. aureus HG001 and human epithelial cells (Surmann et al., 2015 [1]. They have been deposited to the ProteomeXchange platform with the identifiers PRIDE: http://www.ebi.ac.uk/pride/archive/projects/PXD002384 for the S. aureus HG001 proteome dataset and PRIDE: http://www.ebi.ac.uk/pride/archive/projects/PXD002388 for the A549 proteome dataset.

  16. Comparative Proteomics Reveals Differences in Host-Pathogen Interaction between Infectious and Commensal Relationship with Campylobacter jejuni

    Directory of Open Access Journals (Sweden)

    Juan J. Garrido

    2017-04-01

    Full Text Available Campylobacter jejuni is the leading food-borne poisoning in industrialized countries. While the bacteria causes disease in humans, it merely colonizes the gut in poultry or pigs, where seems to establish a commensal relationship. Until now, few studies have been conducted to elucidate the relationship between C. jejuni and its different hosts. In this work, a comparative proteomics approach was used to identify the underlying mechanisms involved in the divergent outcome following C. jejuni infection in human and porcine host. Human (INT-407 and porcine (IPEC-1 intestinal cell lines were infected by C. jejuni for 3 h (T3h and 24 h (T24h. C. jejuni infection prompted an intense inflammatory response at T3h in human intestinal cells, mainly characterized by expression of proteins involved in cell spreading, cell migration and promotion of reactive oxygen species (ROS. Proteomic analysis evidenced significantly regulated biofunctions in human cells related with engulfment and endocytosis, and supported by canonical pathways associated to infection such as caveolar- and clathrin-mediated endocytosis signaling. In porcine IPEC-1 cells, inflammatory response as well as signaling pathways that control cellular functions such as cell migration, endocytosis and cell cycle progression resulted downregulated. These differences in the host response to infection were supported by the different pattern of adhesion and invasion proteins expressed by C. jejuni in human and porcine cells. No marked differences in expression of virulence factors involved in adaptive response and iron acquisition functions were observed. Therefore, the results of this study suggest that both host and pathogen factors are responsible for commensal or infectious character of C. jejuni in different hosts.

  17. Host-Pathogen Interactions in Guillain-Barré Syndrome : the role of Campylobacter jejuni lipooligosaccharide sialylation

    NARCIS (Netherlands)

    A.P. Heikema (Astrid)

    2013-01-01

    markdownabstract*Campylobacter jejuni* (*C. jejuni*) is a spiral, comma-shaped Gram-negative bacterium which is motile due to bipolar flagella. *C. jejuni* is frequently present in the intestines of poultry and birds, where it is considered to be part of the normal intestinal flora (1).

  18. Host-pathogen interactions in specific pathogen-free chickens following aerogenous infection with Chlamydia psittaci and Chlamydia abortus.

    Science.gov (United States)

    Kalmar, Isabelle; Berndt, Angela; Yin, Lizi; Chiers, Koen; Sachse, Konrad; Vanrompay, Daisy

    2015-03-15

    Although Chlamydia (C.) psittaci infections are recognized as an important factor causing economic losses and impairing animal welfare in poultry production, the specific mechanisms leading to severe clinical outcomes are poorly understood. In the present study, we comparatively investigated pathology and host immune response, as well as systemic dissemination and expression of essential chlamydial genes in the course of experimental aerogeneous infection with C. psittaci and the closely related C. abortus, respectively, in specific pathogen-free chicks. Clinical signs appeared sooner and were more severe in the C. psittaci-infected group. Compared to C. abortus infection, more intense systemic dissemination of C. psittaci correlated with higher and faster infiltration of immune cells, as well as more macroscopic lesions and epithelial pathology, such as hyperplasia and erosion. In thoracic air sac tissue, mRNA expression of immunologically relevant factors, such as IFN-γ, IL-1β, IL-6, IL-17, IL-22, LITAF and iNOS was significantly stronger up-regulated in C. psittaci- than in C. abortus-infected birds between 3 and 14 days post-infection. Likewise, transcription rates of the chlamydial genes groEL, cpaf and ftsW were consistently higher in C. psittaci during the acute phase. These findings illustrate that the stronger replication of C. psittaci in its natural host also evoked a more intense immune response than in the case of C. abortus infection. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. A novel approach to probe host-pathogen interactions of bovine digital dermatitis, a model of a complex polymicrobial infection

    DEFF Research Database (Denmark)

    Marcatili, Paolo; Weiss Nielsen, Martin; Sicheritz-Pontén, Thomas

    2016-01-01

    Polymicrobial infections represent a great challenge for the clarification of disease etiology and the development of comprehensive diagnostic or therapeutic tools, particularly for fastidious and difficult-to-cultivate bacteria. Using bovine digital dermatitis (DD) as a disease model, we introduce...... a novel strategy to study the pathogenesis of complex infections. The strategy combines meta-transcriptomics with high-density peptide-microarray technology to screen for in vivo-expressed microbial genes and the host antibody response at the site of infection. Bacterial expression patterns supported....... The extraordinary diversity observed in bacterial expression, antigens and host antibody responses between individual cows pointed toward microbial variability as a hallmark of DD. Persistence of infection and DD reinfection in the same individual is common; thus, high microbial diversity may undermine the host...

  20. Glycosylphosphatidylinositol-anchored proteases of Candida albicans target proteins necessary for both cellular processes and host-pathogen interactions

    Czech Academy of Sciences Publication Activity Database

    Albrecht, A.; Felk, A.; Pichová, Iva; Naglik, J. R.; Schaller, M.; Groot de, P.; MacCallum, D.; Odds, F. C.; Schäfer, W.; Klis, F.; Monod, M.; Hube, B.

    2006-01-01

    Roč. 281, č. 2 (2006), s. 688-694 ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA303/04/0432 Grant - others:DFG(DE) Hu528/8; DFG(DE) Scha897/1; GFC(XE) QLK2-2000-00795; GFC(XE) MRTN-CT-2003-504148 Institutional research plan: CEZ:AV0Z40550506 Keywords : GPL * SAP * GFP * BEC Subject RIV: CE - Biochemistry Impact factor: 5.808, year: 2006

  1. Quantitative proteomic analysis of host--pathogen interactions: a study of Acinetobacter baumannii responses to host airways.

    Science.gov (United States)

    Méndez, Jose Antonio; Mateos, Jesús; Beceiro, Alejandro; Lopez, María; Tomás, María; Poza, Margarita; Bou, Germán

    2015-05-30

    Acinetobacter baumannii is a major health problem. The most common infection caused by A. baumannii is hospital acquired pneumonia, and the associated mortality rate is approximately 50%. Neither in vivo nor ex vivo expression profiling has been performed at the proteomic or transcriptomic level for pneumonia caused by A. baumannii. In this study, we characterized the proteome of A. baumannii under conditions that simulate those found in the airways, to gain some insight into how A. baumannii adapts to the host and to improve knowledge about the pathogenesis and virulence of this bacterium. A clinical strain of A. baumannii was grown under different conditions: in the presence of bronchoalveolar lavage fluid from infected rats, of RAW 264.7 cells to simulate conditions in the respiratory tract and in control conditions. We used iTRAQ labelling and LC-MALDI-TOF/TOF to investigate how A. baumannii responds on exposure to macrophages/BALF. 179 proteins showed differential expression. In both models, proteins involved in the following processes were over-expressed: (i) pathogenesis and virulence (OmpA, YjjK); (ii) cell wall/membrane/envelope biogenesis (MurC); (iii) energy production and conversion (acetyl-CoA hydrolase); and (iv) translation (50S ribosomal protein L9). Proteins involved in the following were under-expressed: (i) lipid metabolism (short-chain dehydrogenase); (ii) amino acid metabolism and transport (aspartate aminotransferase); (iii) unknown function (DNA-binding protein); and (iv) inorganic ion transport and metabolism (hydroperoxidase). We observed alterations in cell wall synthesis and identified 2 upregulated virulence-associated proteins with >15 peptides/protein in both ex vivo models (OmpA and YjjK), suggesting that these proteins are fundamental for pathogenesis and virulence in the airways. This study is the first comprehensive overview of the ex vivo proteome of A. baumannii and is an important step towards identification of diagnostic biomarkers, novel drug targets and potential vaccine candidates in the fight against pneumonia caused by A. baumannii.

  2. Context Matters: Increasing Understanding with Interactive Clicker Case Studies

    Science.gov (United States)

    Lundeberg, Mary A.; Kang, Hosun; Wolter, Bjorn; delMas, Robert; Armstrong, Norris; Borsari, Bruno; Boury, Nancy; Brickman, Peggy; Hannam, Kristi; Heinz, Cheryl; Horvath, Thomas; Knabb, Maureen; Platt, Terry; Rice, Nancy; Rogers, Bill; Sharp, Joan; Ribbens, Eric; Maier, Kimberly S.; Deschryver, Mike; Hagley, Rodney; Goulet, Tamar; Herreid, Clyde F.

    2011-01-01

    Although interactive technology is presumed to increase student understanding in large classes, no previous research studies have empirically explored the effects of Clicker Cases on students' performance. A Clicker Case is a story (e.g., a problem someone is facing) that uses clickers (student response systems) to engage students in understanding…

  3. Understanding Protein Synthesis: An Interactive Card Game Discussion

    Science.gov (United States)

    Lewis, Alison; Peat, Mary; Franklin, Sue

    2005-01-01

    Protein synthesis is a complex process and students find it difficult to understand. This article describes an interactive discussion "game" used by first year biology students at the University of Sydney. The students, in small groups, use the game in which the processes of protein synthesis are actioned by the students during a…

  4. Learning Emotional Understanding and Emotion Regulation through Sibling Interaction

    Science.gov (United States)

    Kramer, Laurie

    2014-01-01

    Research Findings: Young children's relationships with their sisters and brothers offer unique and important opportunities for learning about emotions and developing emotional understanding. Through a critical analysis, this article examines sibling interaction in 3 different but normative contexts (conflict/conflict management, play, and…

  5. FireDetective : Understanding Ajax Client/Server Interactions

    NARCIS (Netherlands)

    Matthijssen, N.; Zaidman, A.

    2011-01-01

    Ajax-enabled web applications are a new breed of highly interactive, highly dynamic web applications. Although Ajax allows developers to create rich web applications, Ajax applications can be difficult to comprehend and thus to maintain. FireDetective aims to facilitate the understanding of Ajax

  6. Understanding and Managing Process Interaction in IS Development Projects

    DEFF Research Database (Denmark)

    Bygstad, Bendik; Nielsen, Peter Axel

    2005-01-01

    Increasingly, information systems must be developed and implemented as a part of business change. This is a challenge for the IS project manager, since business change and information systems development usually are performed as separate processes. Thus, there is a need to understand and manage......-technical innovation in a situation where the organisational change process and the IS development process are parallel but incongruent. We also argue that iterative software engineering frameworks are well structured to support process interaction. Finally, we advocate that the IS project manager needs to manage...... the relationship between these two kinds of processes. To understand the interaction between information systems development and planned organisational change we introduce the concept of process interaction. We draw on a longitudinal case study of an IS development project that used an iterative and incremental...

  7. Immobilized enzymes: understanding enzyme - surface interactions at the molecular level.

    Science.gov (United States)

    Hoarau, Marie; Badieyan, Somayesadat; Marsh, E Neil G

    2017-11-22

    Enzymes immobilized on solid supports have important and industrial and medical applications. However, their uses are limited by the significant reductions in activity and stability that often accompany the immobilization process. Here we review recent advances in our understanding of the molecular level interactions between proteins and supporting surfaces that contribute to changes in stability and activity. This understanding has been facilitated by the application of various surface-sensitive spectroscopic techniques that allow the structure and orientation of enzymes at the solid/liquid interface to be probed, often with monolayer sensitivity. An appreciation of the molecular interactions between enzyme and surface support has allowed the surface chemistry and method of enzyme attachement to be fine-tuned such that activity and stability can be greatly enhanced. These advances suggest that a much wider variety of enzymes may eventually be amenable to immobilization as green catalysts.

  8. Towards a systems understanding of plant-microbe interactions

    Directory of Open Access Journals (Sweden)

    Akira eMine

    2014-08-01

    Full Text Available Plants are closely associated with microorganisms including pathogens and mutualists that influence plant fitness. Molecular genetic approaches have uncovered a number of signaling components from both plants and microbes and their mode of actions. However, signaling pathways are highly interconnected and influenced by diverse sets of environmental factors. Therefore, it is important to have systems views in order to understand the true nature of plant-microbe interactions. Indeed, systems biology approaches have revealed previously overlooked or misinterpreted properties of the plant immune signaling network. Experimental reconstruction of biological networks using exhaustive combinatorial mutants is particularly powerful to elucidate network structure and properties and relationships among network components. Recent advances in metagenomics of microbial communities associated with plants further point to the importance of systems approaches and open a research area of microbial community reconstruction. In this review, we highlight the importance of a systems understanding of plant-microbe interactions, with a special emphasis on reconstruction strategies.

  9. Pseudomonas predators: understanding and exploiting phage-host interactions.

    Science.gov (United States)

    De Smet, Jeroen; Hendrix, Hanne; Blasdel, Bob G; Danis-Wlodarczyk, Katarzyna; Lavigne, Rob

    2017-09-01

    Species in the genus Pseudomonas thrive in a diverse set of ecological niches and include crucial pathogens, such as the human pathogen Pseudomonas aeruginosa and the plant pathogen Pseudomonas syringae. The bacteriophages that infect Pseudomonas spp. mirror the widespread and diverse nature of their hosts. Therefore, Pseudomonas spp. and their phages are an ideal system to study the molecular mechanisms that govern virus-host interactions. Furthermore, phages are principal catalysts of host evolution and diversity, which directly affects the ecological roles of environmental and pathogenic Pseudomonas spp. Understanding these interactions not only provides novel insights into phage biology but also advances the development of phage therapy, phage-derived antimicrobial strategies and innovative biotechnological tools that may be derived from phage-bacteria interactions.

  10. Stringent homology-based prediction of H. sapiens-M. tuberculosis H37Rv protein-protein interactions.

    Science.gov (United States)

    Zhou, Hufeng; Gao, Shangzhi; Nguyen, Nam Ninh; Fan, Mengyuan; Jin, Jingjing; Liu, Bing; Zhao, Liang; Xiong, Geng; Tan, Min; Li, Shijun; Wong, Limsoon

    2014-04-08

    H. sapiens-M. tuberculosis H37Rv protein-protein interaction (PPI) data are essential for understanding the infection mechanism of the formidable pathogen M. tuberculosis H37Rv. Computational prediction is an important strategy to fill the gap in experimental H. sapiens-M. tuberculosis H37Rv PPI data. Homology-based prediction is frequently used in predicting both intra-species and inter-species PPIs. However, some limitations are not properly resolved in several published works that predict eukaryote-prokaryote inter-species PPIs using intra-species template PPIs. We develop a stringent homology-based prediction approach by taking into account (i) differences between eukaryotic and prokaryotic proteins and (ii) differences between inter-species and intra-species PPI interfaces. We compare our stringent homology-based approach to a conventional homology-based approach for predicting host-pathogen PPIs, based on cellular compartment distribution analysis, disease gene list enrichment analysis, pathway enrichment analysis and functional category enrichment analysis. These analyses support the validity of our prediction result, and clearly show that our approach has better performance in predicting H. sapiens-M. tuberculosis H37Rv PPIs. Using our stringent homology-based approach, we have predicted a set of highly plausible H. sapiens-M. tuberculosis H37Rv PPIs which might be useful for many of related studies. Based on our analysis of the H. sapiens-M. tuberculosis H37Rv PPI network predicted by our stringent homology-based approach, we have discovered several interesting properties which are reported here for the first time. We find that both host proteins and pathogen proteins involved in the host-pathogen PPIs tend to be hubs in their own intra-species PPI network. Also, both host and pathogen proteins involved in host-pathogen PPIs tend to have longer primary sequence, tend to have more domains, tend to be more hydrophilic, etc. And the protein domains from both

  11. Nuclear Fusion Research Understanding Plasma-Surface Interactions

    CERN Document Server

    Clark, Robert E.H

    2005-01-01

    It became clear in the early days of fusion research that the effects of the containment vessel (erosion of "impurities") degrade the overall fusion plasma performance. Progress in controlled nuclear fusion research over the last decade has led to magnetically confined plasmas that, in turn, are sufficiently powerful to damage the vessel structures over its lifetime. This book reviews current understanding and concepts to deal with this remaining critical design issue for fusion reactors. It reviews both progress and open questions, largely in terms of available and sought-after plasma-surface interaction data and atomic/molecular data related to these "plasma edge" issues.

  12. Pollution prevention and energy conservation: Understanding the interactions

    International Nuclear Information System (INIS)

    Purcell, A.H.

    1992-01-01

    The traditional view holds that pollution prevention is good for energy conservation and vice versa. Analysis of pollution prevention and energy conservation activities indicates, however, that interactions and synergies between environmental and energy factors can mean that pollution prevention can be energy intensive and, conversely, that energy conservation can lead to increased pollution. Full cost accounting, taking into account all media, must be performed before precise pollution prevention-energy conservation interrelationships can be characterized and quantified. Use of a pollution prevention-energy conservation matrix can further this understanding

  13. The seaweed holobiont: understanding seaweed-bacteria interactions.

    Science.gov (United States)

    Egan, Suhelen; Harder, Tilmann; Burke, Catherine; Steinberg, Peter; Kjelleberg, Staffan; Thomas, Torsten

    2013-05-01

    Seaweeds (macroalgae) form a diverse and ubiquitous group of photosynthetic organisms that play an essential role in aquatic ecosystems. These ecosystem engineers contribute significantly to global primary production and are the major habitat formers on rocky shores in temperate waters, providing food and shelter for aquatic life. Like other eukaryotic organisms, macroalgae harbor a rich diversity of associated microorganisms with functions related to host health and defense. In particular, epiphytic bacterial communities have been reported as essential for normal morphological development of the algal host, and bacteria with antifouling properties are thought to protect chemically undefended macroalgae from detrimental, secondary colonization by other microscopic and macroscopic epibiota. This tight relationship suggests that macroalgae and epiphytic bacteria interact as a unified functional entity or holobiont, analogous to the previously suggested relationship in corals. Moreover, given that the impact of diseases in marine ecosystems is apparently increasing, understanding the role of bacteria as saprophytes and pathogens in seaweed communities may have important implications for marine management strategies. This review reports on the recent advances in the understanding of macroalgal-bacterial interactions with reference to the diversity and functional role of epiphytic bacteria in maintaining algal health, highlighting the holobiont concept. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  14. Current understanding of interactions between nanoparticles and the immune system.

    Science.gov (United States)

    Dobrovolskaia, Marina A; Shurin, Michael; Shvedova, Anna A

    2016-05-15

    The delivery of drugs, antigens, and imaging agents benefits from using nanotechnology-based carriers. The successful translation of nanoformulations to the clinic involves thorough assessment of their safety profiles, which, among other end-points, includes evaluation of immunotoxicity. The past decade of research focusing on nanoparticle interaction with the immune system has been fruitful in terms of understanding the basics of nanoparticle immunocompatibility, developing a bioanalytical infrastructure to screen for nanoparticle-mediated immune reactions, beginning to uncover the mechanisms of nanoparticle immunotoxicity, and utilizing current knowledge about the structure-activity relationship between nanoparticles' physicochemical properties and their effects on the immune system to guide safe drug delivery. In the present review, we focus on the most prominent pieces of the nanoparticle-immune system puzzle and discuss the achievements, disappointments, and lessons learned over the past 15years of research on the immunotoxicity of engineered nanomaterials. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Understanding the Interaction between a Steel Microstructure and Hydrogen

    Science.gov (United States)

    Depover, Tom; Laureys, Aurélie; Wallaert, Elien

    2018-01-01

    The present work provides an overview of the work on the interaction between hydrogen (H) and the steel’s microstructure. Different techniques are used to evaluate the H-induced damage phenomena. The impact of H charging on multiphase high-strength steels, i.e., high-strength low-alloy (HSLA), transformation-induced plasticity (TRIP) and dual phase (DP) is first studied. The highest hydrogen embrittlement resistance is obtained for HSLA steel due to the presence of Ti- and Nb-based precipitates. Generic Fe-C lab-cast alloys consisting of a single phase, i.e., ferrite, bainite, pearlite or martensite, and with carbon contents of approximately 0, 0.2 and 0.4 wt %, are further considered to simplify the microstructure. Finally, the addition of carbides is investigated in lab-cast Fe-C-X alloys by adding a ternary carbide forming element to the Fe-C alloys. To understand the H/material interaction, a comparison of the available H trapping sites, the H pick-up level and the H diffusivity with the H-induced mechanical degradation or H-induced cracking is correlated with a thorough microstructural analysis. PMID:29710803

  16. Towards a better understanding of Lactobacillus rhamnosus GG - host interactions

    Science.gov (United States)

    2014-01-01

    Lactobacillus rhamnosus GG (LGG) is one of the most widely used probiotic strains. Various health effects are well documented including the prevention and treatment of gastro-intestinal infections and diarrhea, and stimulation of immune responses that promote vaccination or even prevent certain allergic symptoms. However, not all intervention studies could show a clinical benefit and even for the same conditions, the results are not univocal. Clearly, the host phenotype governed by age, genetics and environmental factors such as the endogenous microbiota, plays a role in whether individuals are responders or non-responders. However, we believe that a detailed knowledge of the bacterial physiology and the LGG molecules that play a key role in its host-interaction capacity is crucial for a better understanding of its potential health benefits. Molecules that were yet identified as important factors governing host interactions include its adhesive pili or fimbriae, its lipoteichoic acid molecules, its major secreted proteins and its galactose-rich exopolysaccharides, as well as specific DNA motifs. Nevertheless, future studies are needed to correlate specific health effects to these molecular effectors in LGG, and also in other probiotic strains. PMID:25186587

  17. Antagonism between salicylic and abscisic acid reflects early host-pathogen conflict and moulds plant defence responses.

    Science.gov (United States)

    de Torres Zabala, Marta; Bennett, Mark H; Truman, William H; Grant, Murray R

    2009-08-01

    The importance of phytohormone balance is increasingly recognized as central to the outcome of plant-pathogen interactions. Recently it has been demonstrated that abscisic acid signalling pathways are utilized by the bacterial phytopathogen Pseudomonas syringae to promote pathogenesis. In this study, we examined the dynamics, inter-relationship and impact of three key acidic phytohormones, salicylic acid, abscisic acid and jasmonic acid, and the bacterial virulence factor, coronatine, during progression of P. syringae infection of Arabidopsis thaliana. We show that levels of SA and ABA, but not JA, appear to play important early roles in determining the outcome of the infection process. SA is required in order to mount a full innate immune responses, while bacterial effectors act rapidly to activate ABA biosynthesis. ABA suppresses inducible innate immune responses by down-regulating SA biosynthesis and SA-mediated defences. Mutant analyses indicated that endogenous ABA levels represent an important reservoir that is necessary for effector suppression of plant-inducible innate defence responses and SA synthesis prior to subsequent pathogen-induced increases in ABA. Enhanced susceptibility due to loss of SA-mediated basal resistance is epistatically dominant over acquired resistance due to ABA deficiency, although ABA also contributes to symptom development. We conclude that pathogen-modulated ABA signalling rapidly antagonizes SA-mediated defences. We predict that hormonal perturbations, either induced or as a result of environmental stress, have a marked impact on pathological outcomes, and we provide a mechanistic basis for understanding priming events in plant defence.

  18. Current understanding of interactions between nanoparticles and the immune system

    International Nuclear Information System (INIS)

    Dobrovolskaia, Marina A.; Shurin, Michael; Shvedova, Anna A.

    2016-01-01

    The delivery of drugs, antigens, and imaging agents benefits from using nanotechnology-based carriers. The successful translation of nanoformulations to the clinic involves thorough assessment of their safety profiles, which, among other end-points, includes evaluation of immunotoxicity. The past decade of research focusing on nanoparticle interaction with the immune system has been fruitful in terms of understanding the basics of nanoparticle immunocompatibility, developing a bioanalytical infrastructure to screen for nanoparticle-mediated immune reactions, beginning to uncover the mechanisms of nanoparticle immunotoxicity, and utilizing current knowledge about the structure–activity relationship between nanoparticles' physicochemical properties and their effects on the immune system to guide safe drug delivery. In the present review, we focus on the most prominent pieces of the nanoparticle–immune system puzzle and discuss the achievements, disappointments, and lessons learned over the past 15 years of research on the immunotoxicity of engineered nanomaterials. - Graphical abstract: API — active pharmaceutical ingredient; NP — nanoparticles; PCP — physicochemical properties, CARPA — complement activation-related pseudoallergy, ICH — International Conference on Harmonization. Display Omitted - Highlights: • Achievements, disappointments and lessons learned over past decade are reviewed. • Areas in focus include characterization, immunotoxicity and utility in drug delivery. • Future direction focusing on mechanistic immunotoxicity studies is proposed.

  19. Current understanding of interactions between nanoparticles and the immune system

    Energy Technology Data Exchange (ETDEWEB)

    Dobrovolskaia, Marina A., E-mail: marina@mail.nih.gov [Nanotechnology Characterization Laboratory, Cancer Research Technology Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, NCI at Frederick, Frederick, MD 21702 (United States); Shurin, Michael [Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States); Department of Immunology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States); Shvedova, Anna A., E-mail: ats1@cdc.gov [Health Effects Laboratory Division, National Institute of Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505 (United States); Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506 (United States)

    2016-05-15

    The delivery of drugs, antigens, and imaging agents benefits from using nanotechnology-based carriers. The successful translation of nanoformulations to the clinic involves thorough assessment of their safety profiles, which, among other end-points, includes evaluation of immunotoxicity. The past decade of research focusing on nanoparticle interaction with the immune system has been fruitful in terms of understanding the basics of nanoparticle immunocompatibility, developing a bioanalytical infrastructure to screen for nanoparticle-mediated immune reactions, beginning to uncover the mechanisms of nanoparticle immunotoxicity, and utilizing current knowledge about the structure–activity relationship between nanoparticles' physicochemical properties and their effects on the immune system to guide safe drug delivery. In the present review, we focus on the most prominent pieces of the nanoparticle–immune system puzzle and discuss the achievements, disappointments, and lessons learned over the past 15 years of research on the immunotoxicity of engineered nanomaterials. - Graphical abstract: API — active pharmaceutical ingredient; NP — nanoparticles; PCP — physicochemical properties, CARPA — complement activation-related pseudoallergy, ICH — International Conference on Harmonization. Display Omitted - Highlights: • Achievements, disappointments and lessons learned over past decade are reviewed. • Areas in focus include characterization, immunotoxicity and utility in drug delivery. • Future direction focusing on mechanistic immunotoxicity studies is proposed.

  20. Understanding Protein-Protein Interactions Using Local Structural Features

    DEFF Research Database (Denmark)

    Planas-Iglesias, Joan; Bonet, Jaume; García-García, Javier

    2013-01-01

    Protein-protein interactions (PPIs) play a relevant role among the different functions of a cell. Identifying the PPI network of a given organism (interactome) is useful to shed light on the key molecular mechanisms within a biological system. In this work, we show the role of structural features...... interacting and non-interacting protein pairs to classify the structural features that sustain the binding (or non-binding) behavior. Our study indicates that not only the interacting region but also the rest of the protein surface are important for the interaction fate. The interpretation...... to score the likelihood of the interaction between two proteins and to develop a method for the prediction of PPIs. We have tested our method on several sets with unbalanced ratios of interactions and non-interactions to simulate real conditions, obtaining accuracies higher than 25% in the most unfavorable...

  1. Understanding Molecular Interactions within Chemically Selective Layered Polymer Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Gary J. Blanchard

    2009-06-30

    This work focuses on two broad issues. These are (1) the molecular origin of the chemical selectivity achieved with ultrathin polymer multilayers, and (2) how the viscoelastic properties of the polymer layers are affected by exposure to solvent and analytes. These issues are inter-related, and to understand them we need to design experiments that probe both the energetic and kinetic aspects of interfacial adsorption processes. This project focuses on controling the chemical structure, thickness, morphology and sequential ordering of polymer layers bound to interfaces using maleimide-vinyl ether and closely related alternating copolymerization chemistry and efficient covalent cross-linking reactions that allow for layer-by-layer polymer deposition. This chemistry has been developed during the funding cycle of this Grant. We have measure the equilibrium constants for interactions between specific layers within the polymer interfaces and size-controlled, surface-functionalized gold nanoparticles. The ability to control both size and functionality of gold nanoparticle model analytes allows us to evaluate the average “pore size” that characterizes our polymer films. We have measured the “bulk” viscosity and shear modulus of the ultrathin polymer films as a function of solvent overlayer identity using quartz crystal microbalance complex impedance measurements. We have measured microscopic viscosity at specific locations within the layered polymer interfaces with time-resolved fluorescence lifetime and depolarization techniques. We combine polymer, cross-linking and nanoparticle synthetic expertise with a host of characterization techniques, including QCM gravimetry and complex impedance analysis, steady state and time-resolved spectroscopies.

  2. The essential interactions between understanding climate variability and climate change

    Science.gov (United States)

    Neelin, J. D.

    2017-12-01

    Global change is sometimes perceived as a field separate from other aspects of atmospheric and oceanic sciences. Despite the long history of communication between the scientific communities studying global change and those studying interannual variability and weather, increasing specialization and conflicting societal demands on the fields can put these interactions at risk. At the same time, current trajectories for greenhouse gas emissions imply substantial adaptation to climate change will be necessary. Instead of simply projecting effects to be avoided, the field is increasingly being asked to provide regional-level information for specific adaptation strategies—with associated requirements for increased precision on projections. For extreme events, challenges include validating models for rare events, especially for events that are unprecedented in the historical record. These factors will be illustrated with examples of information transfer to climate change from work on fundamental climate processes aimed originally at timescales from hours to interannual. Work to understand the effects that control probability distributions of moisture, temperature and precipitation in historical weather can yield new factors to examine for the changes in the extremes of these distributions under climate change. Surprisingly simple process models can give insights into the behavior of vastly more complex climate models. Observation systems and model ensembles aimed at weather and interannual variations prove valuable for global change and vice versa. Work on teleconnections in the climate system, such as the remote impacts of El Niño, is informing analysis of projected regional rainfall change over California. Young scientists need to prepare to work across the full spectrum of climate variability and change, and to communicate their findings, as they and our society head for future that is more interesting than optimal.

  3. Conserved host-pathogen PPIs. Globally conserved inter-species bacterial PPIs based conserved host-pathogen interactome derived novel target in C. pseudotuberculosis, C. diphtheriae, M. tuberculosis, C. ulcerans, Y. pestis, and E. coli targeted by Piper betel compounds

    DEFF Research Database (Denmark)

    Barh, Debmalya; Gupta, Krishnakant; Jain, Neha

    2013-01-01

    of Caseous Lymphadenitis (CLA). In this study, we used computational approaches to develop common conserved intra-species protein-protein interaction (PPI) networks first time for four Cp strains (Cp FRC41, Cp 316, Cp 3/99-5, and Cp P54B96) followed by development of a common conserved inter...

  4. Understanding protein–protein interactions by genetic suppression

    Indian Academy of Sciences (India)

    Unknown

    Protein–protein interactions influence many cellular processes and it is increasingly being felt that even a weak and ... In a bacterial system where the complete genome sequence is available, it is an arduous ... teins (primary mutations) are useful in these studies. ... of interaction of this antibiotic with the central enzyme.

  5. Proteomics Advances in the Understanding of Pollen–Pistil Interactions

    Directory of Open Access Journals (Sweden)

    Ziyang Fu

    2014-09-01

    Full Text Available The first key point to the successful pollination and fertilization in plants is the pollen-pistil interaction, referring to the cellular and molecular levels, which mainly involve the haploid pollen and the diploid pistil. The process is defined as “siphonogamy”, which starts from the capture of pollen by the epidermis of stigma and ends up with the fusion of sperm with egg. So far, the studies of the pollen-pistil interaction have been explicated around the self-compatibility and self-incompatibility (SI process in different species from the molecular genetics and biochemistry to cellular and signal levels, especially the mechanism of SI system. Among them, numerous proteomics studies based on the advanced technologies from gel-system to gel-free system were conducted, focusing on the interaction, in order to uncover the mechanism of the process. The current review mainly focuses on the recent developments in proteomics of pollen-pistil interaction from two aspects: self-incompatible and compatible pollination. It might provide a comprehensive insight on the proteins that were involved in the regulation of pollen-pistil interaction.

  6. Mechanisms of Host-Pathogen Protein Complex Formation and Bacterial Immune Evasion of Streptococcus suis Protein Fhb.

    Science.gov (United States)

    Li, Xueqin; Liu, Peng; Gan, Shuzhen; Zhang, Chunmao; Zheng, Yuling; Jiang, Yongqiang; Yuan, Yuan

    2016-08-12

    Streptococcus suis serotype 2 (S. suis 2)-induced sepsis and meningitis are often accompanied by bacteremia. The evasion of polymorphonuclear leukocyte-mediated phagocytic clearance is central to the establishment of bacteremia caused by S. suis 2 and is facilitated by the ability of factor H (FH)-binding protein (Fhb) to bind FH on the bacterial surface, thereby impeding alternative pathway complement activation and phagocytic clearance. Here, C3b/C3d was found to bind to Fhb, along with FH, forming a large immune complex. The formation of this immune complex was mediated by domain II of Fhb via electrostatic and hydrophobic interactions, which, to our knowledge, is a new type of interaction. Interestingly, Fhb was found to be associated with the cell envelope and also present in the culture supernatant, where secreted Fhb inhibited complement activation via interactions with domain II, thereby enhancing antiphagocytic clearance by polymorphonuclear leukocytes. Thus, Fhb is a multifunctional bacterial protein, which binds host complement component C3 as well as FH and interferes with innate immune recognition in a secret protein manner. S. suis 2 therefore appears to have developed a new strategy to combat host innate immunity and enhance survival in host blood. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Mechanisms of Host-Pathogen Protein Complex Formation and Bacterial Immune Evasion of Streptococcus suis Protein Fhb*

    Science.gov (United States)

    Li, Xueqin; Liu, Peng; Gan, Shuzhen; Zhang, Chunmao; Zheng, Yuling; Jiang, Yongqiang; Yuan, Yuan

    2016-01-01

    Streptococcus suis serotype 2 (S. suis 2)-induced sepsis and meningitis are often accompanied by bacteremia. The evasion of polymorphonuclear leukocyte-mediated phagocytic clearance is central to the establishment of bacteremia caused by S. suis 2 and is facilitated by the ability of factor H (FH)-binding protein (Fhb) to bind FH on the bacterial surface, thereby impeding alternative pathway complement activation and phagocytic clearance. Here, C3b/C3d was found to bind to Fhb, along with FH, forming a large immune complex. The formation of this immune complex was mediated by domain II of Fhb via electrostatic and hydrophobic interactions, which, to our knowledge, is a new type of interaction. Interestingly, Fhb was found to be associated with the cell envelope and also present in the culture supernatant, where secreted Fhb inhibited complement activation via interactions with domain II, thereby enhancing antiphagocytic clearance by polymorphonuclear leukocytes. Thus, Fhb is a multifunctional bacterial protein, which binds host complement component C3 as well as FH and interferes with innate immune recognition in a secret protein manner. S. suis 2 therefore appears to have developed a new strategy to combat host innate immunity and enhance survival in host blood. PMID:27342778

  8. Optically polarized atoms understanding light-atom interactions

    CERN Document Server

    Auzinsh, Marcis; Rochester, Simon M

    2010-01-01

    This book is addressed at upper-level undergraduate and graduate students involved in research in atomic, molecular, and optical Physics. It will also be useful to researchers practising in this field. It gives an intuitive, yet sufficiently detailed and rigorous introduction to light-atom interactions with a particular emphasis on the symmetry aspects of the interaction, especially those associated with the angular momentum of atoms and light. The book will enable readers to carryout practical calculations on their own, and is richly illustrated with examples drawn from current research topic

  9. Understanding Peptide Dendrimer Interactions with Model Cell Membrane Mimics

    DEFF Research Database (Denmark)

    Lind, Tania Kjellerup

    few new drugs have been marketed over the last decades, making it impossible to keep pace with the disturbing levels of multi-drug resistant bacteria. Research in the area of novel drugs, which are less prone to induce resistance, and in-depth knowledge on their uptake mechanisms is thus of paramount...... fusion method, which presents improved means for studying drug-membrane interactions in the future. The interaction mechanism of a family of dendrimers was examined and in particular one dendrimer (BALY) was extensively studied by the combined use of quartz crystal microbalance, atomic force microscopy...

  10. Understanding and Creating Accessible Touch Screen Interactions for Blind People

    Science.gov (United States)

    Kane, Shaun K.

    2011-01-01

    Using touch screens presents a number of usability and accessibility challenges for blind people. Most touch screen-based user interfaces are optimized for visual interaction, and are therefore difficult or impossible to use without vision. This dissertation presents an approach to redesigning gesture-based user interfaces to enable blind people…

  11. Connecting traces : Understanding client-server interactions in Ajax applications

    NARCIS (Netherlands)

    Matthijssen, N.; Zaidman, A.; Storey, M.; Bull, I.; Van Deursen, A.

    2010-01-01

    Ajax-enabled web applications are a new breed of highly interactive, highly dynamic web applications. Although Ajax allows developers to create rich web applications, Ajax applications can be difficult to comprehend and thus to maintain. For this reason, we have created FireDetective, a tool that

  12. Understanding the Dynamic System of Terrorist-Government Interaction

    Science.gov (United States)

    2003-03-01

    Figure 62. Model 5D Equation Level Screen Shot 3 167 Bibliography Bajaracharya, Arun, Stephen Olu Ogunlana, and Nguyen Luong Bach...Understanding the New Security Environment Readings and Interpretations. Guilford, Connecticut: Mc- Graw -Hill/Dushkin 2002 Laqueur, Walter. “Postmodern

  13. Understanding and Managing Process Interaction in IS Development Projects

    DEFF Research Database (Denmark)

    Bygstad, Bendik; Nielsen, Peter Axel

    2012-01-01

    Software-based information systems must be developed and implemented as a part of business change. This is a major challenge, since business change and the development of software-based information systems usually are performed in separate processes. Thus, there is a need to understand and manage...... critical events in the case, what led to the events, and what the consequences are. We discuss the implications for information systems research and in particular we discuss the contribution to project management of iterative and incremental software development.......Software-based information systems must be developed and implemented as a part of business change. This is a major challenge, since business change and the development of software-based information systems usually are performed in separate processes. Thus, there is a need to understand and manage...

  14. Understanding WIMP-baryon interactions with direct detection: a roadmap

    International Nuclear Information System (INIS)

    Gluscevic, Vera; Peter, Annika H.G.

    2014-01-01

    We study prospects of dark-matter direct-detection searches for probing non-relativistic effective theory for WIMP-baryon scattering. We simulate a large set of noisy recoil-energy spectra for different scattering scenarios (beyond the standard momentum-independent contact interaction), for Generation 2 and futuristic experiments. We analyze these simulations and quantify the probability of successfully identifying the operator governing the scattering, if a WIMP signal is observed. We find that the success rate depends on a combination of factors: the WIMP mass, the mediator mass, the type of interaction, and the experimental energy window. For example, for a 20 GeV WIMP, Generation 2 is only likely to identify the right operator if the interaction is Coulomb-like, and is unlikely to do so in any other case. For a WIMP with a mass of 200 GeV or higher, success is almost guaranteed. We also find that, regardless of the scattering model and the WIMP parameters, a single Generation 2 experiment is unlikely to successfully discern the momentum dependence of the underlying operator on its own, but prospects improve drastically when experiments with different target materials and energy windows are analyzed jointly. Furthermore, we examine the quality of parameter estimation and degeneracies in the multi-dimensional parameter space of the effective theory. We find in particular that the resulting WIMP mass estimates can be severely biased if data are analyzed assuming the standard (momentum-independent) operator while the actual operator has momentum-dependence. Finally, we evaluate the ultimate reach of direct detection, finding that the prospects for successful operator selection prior to reaching the irreducible backgrounds are excellent, if the signal is just below the current limits, but slim if Generation 2 does not report WIMP detection

  15. Conservation Physiology and Conservation Pathogens: White-Nose Syndrome and Integrative Biology for Host-Pathogen Systems.

    Science.gov (United States)

    Willis, Craig K R

    2015-10-01

    Conservation physiology aims to apply an understanding of physiological mechanisms to management of imperiled species, populations, or ecosystems. One challenge for physiologists hoping to apply their expertise to conservation is connecting the mechanisms we study, often in the laboratory, with the vital rates of populations in the wild. There is growing appreciation that infectious pathogens can threaten populations and species, and represent an important issue for conservation. Conservation physiology has much to offer in terms of addressing the threat posed to some host species by infectious pathogens. At the same time, the well-developed theoretical framework of disease ecology could provide a model to help advance the application of physiology to a range of other conservation issues. Here, I use white-nose syndrome (WNS) in hibernating North American bats as an example of a conservation problem for which integrative physiological research has been a critical part of research and management. The response to WNS highlights the importance of a well-developed theoretical framework for the application of conservation physiology to a particular threat. I review what is known about physiological mechanisms associated with mortality from WNS and emphasize the value of combining a strong theoretical background with integrative physiological studies in order to connect physiological mechanisms with population processes and thereby maximize the potential benefits of conservation physiology. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  16. Spatiotemporal dynamics in understanding hand—object interactions

    Science.gov (United States)

    Avanzini, Pietro; Fabbri-Destro, Maddalena; Campi, Cristina; Pascarella, Annalisa; Barchiesi, Guido; Cattaneo, Luigi; Rizzolatti, Giacomo

    2013-01-01

    It is generally accepted that visual perception results from the activation of a feed-forward hierarchy of areas, leading to increasingly complex representations. Here we present evidence for a fundamental role of backward projections to the occipito-temporal region for understanding conceptual object properties. The evidence is based on two studies. In the first study, using high-density EEG, we showed that during the observation of how objects are used there is an early activation of occipital and temporal areas, subsequently reaching the pole of the temporal lobe, and a late reactivation of the visual areas. In the second study, using transcranial magnetic stimulation over the occipital lobe, we showed a clear impairment in the accuracy of recognition of how objects are used during both early activation and, most importantly, late occipital reactivation. These findings represent strong neurophysiological evidence that a top-down mechanism is fundamental for understanding conceptual object properties, and suggest that a similar mechanism might be also present for other higher-order cognitive functions. PMID:24043805

  17. Hi-Jack: a novel computational framework for pathway-based inference of host–pathogen interactions

    KAUST Repository

    Kleftogiannis, Dimitrios A.; Wong, Limsoon; Archer, John A.C.; Kalnis, Panos

    2015-01-01

    also describe host-pathogen interaction principles that can be used in the future for subsequent studies. Our case study on Mycobacterium tuberculosis (Mtb) revealed pathways in human-e.g. carbohydrate metabolism, lipids metabolism and pathways related

  18. Understanding Mesoscale Land-Atmosphere Interactions in Arctic Region

    Science.gov (United States)

    Hong, X.; Wang, S.; Nachamkin, J. E.

    2017-12-01

    Land-atmosphere interactions in Arctic region are examined using the U.S. Navy Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS©*) with the Noah Land Surface Model (LSM). Initial land surface variables in COAMPS are interpolated from the real-time NASA Land Information System (LIS). The model simulations are configured for three nest grids with 27-9-3 km horizontal resolutions. The simulation period is set for October 2015 with 12-h data assimilation update cycle and 24-h integration length. The results are compared with those simulated without using LSM and evaluated with observations from ONR Sea State R/V Sikuliaq cruise and the North Slope of Alaska (NSA). There are complex soil and vegetation types over the surface for simulation with LSM, compared to without LSM simulation. The results show substantial differences in surface heat fluxes between bulk surface scheme and LSM, which may have an important impact on the sea ice evolution over the Arctic region. Evaluations from station data show surface air temperature and relative humidity have smaller biases for simulation using LSM. Diurnal variation of land surface temperature, which is necessary for physical processes of land-atmosphere, is also better captured than without LSM.

  19. Inverse pH regulation of plant and fungal sucrose transporters: a mechanism to regulate competition for sucrose at the host/pathogen interface?

    Directory of Open Access Journals (Sweden)

    Kathrin Wippel

    Full Text Available BACKGROUND: Plant sucrose transporter activities were shown to respond to changes in the extracellular pH and redox status, and oxidizing compounds like glutathione (GSSG or H(2O(2 were reported to effect the subcellular targeting of these proteins. We hypothesized that changes in both parameters might be used to modulate the activities of competing sucrose transporters at a plant/pathogen interface. We, therefore, compared the effects of redox-active compounds and of extracellular pH on the sucrose transporters UmSRT1 and ZmSUT1 known to compete for extracellular sucrose in the Ustilago maydis (corn smut/Zea mays (maize pathosystem. METHODOLOGY/PRINCIPAL FINDINGS: We present functional analyses of the U. maydis sucrose transporter UmSRT1 and of the plant sucrose transporters ZmSUT1 and StSUT1 in Saccharomyces cerevisiae or in Xenopus laevis oocytes in the presence of different extracellular pH-values and redox systems, and study the possible effects of these treatments on the subcellular targeting. We observed an inverse regulation of host and pathogen sucrose transporters by changes in the apoplastic pH. Under none of the conditions analyzed, we could confirm the reported effects of redox-active compounds. CONCLUSIONS/SIGNIFICANCE: Our data suggest that changes in the extracellular pH but not of the extracellular redox status might be used to oppositely adjust the transport activities of plant and fungal sucrose transporters at the host/pathogen interface.

  20. A Network Approach of Gene Co-expression in the Zea mays/Aspergillus flavus Pathosystem to Map Host/Pathogen Interaction Pathways

    Science.gov (United States)

    Musungu, Bryan M.; Bhatnagar, Deepak; Brown, Robert L.; Payne, Gary A.; OBrian, Greg; Fakhoury, Ahmad M.; Geisler, Matt

    2016-01-01

    A gene co-expression network (GEN) was generated using a dual RNA-seq study with the fungal pathogen Aspergillus flavus and its plant host Zea mays during the initial 3 days of infection. The analysis deciphered novel pathways and mapped genes of interest in both organisms during the infection. This network revealed a high degree of connectivity in many of the previously recognized pathways in Z. mays such as jasmonic acid, ethylene, and reactive oxygen species (ROS). For the pathogen A. flavus, a link between aflatoxin production and vesicular transport was identified within the network. There was significant interspecies correlation of expression between Z. mays and A. flavus for a subset of 104 Z. mays, and 1942 A. flavus genes. This resulted in an interspecies subnetwork enriched in multiple Z. mays genes involved in the production of ROS. In addition to the ROS from Z. mays, there was enrichment in the vesicular transport pathways and the aflatoxin pathway for A. flavus. Included in these genes, a key aflatoxin cluster regulator, AflS, was found to be co-regulated with multiple Z. mays ROS producing genes within the network, suggesting AflS may be monitoring host ROS levels. The entire GEN for both host and pathogen, and the subset of interspecies correlations, is presented as a tool for hypothesis generation and discovery for events in the early stages of fungal infection of Z. mays by A. flavus. PMID:27917194

  1. A Network Approach of Gene Co-expression in the Zea mays/Aspergillus flavus Pathosystem to Map Host/Pathogen Interaction Pathways

    OpenAIRE

    Musungu, Bryan M.; Bhatnagar, Deepak; Brown, Robert L.; Payne, Gary A.; OBrian, Greg; Fakhoury, Ahmad M.; Geisler, Matt

    2016-01-01

    A gene co-expression network (GEN) was generated using a dual RNA-seq study with the fungal pathogen Aspergillus flavus and its plant host Zea mays during the initial 3 days of infection. The analysis deciphered novel pathways and mapped genes of interest in both organisms during the infection. This network revealed a high degree of connectivity in many of the previously recognized pathways in Z. mays such as jasmonic acid, ethylene, and reactive oxygen species (ROS). For the pathogen A. flav...

  2. Microgravity as a biological tool to examine host-pathogen interactions and to guide development of therapeutics and preventatives that target pathogenic bacteria.

    Science.gov (United States)

    Higginson, Ellen E; Galen, James E; Levine, Myron M; Tennant, Sharon M

    2016-11-01

    Space exploration programs have long been interested in the effects of spaceflight on biology. This research is important not only in its relevance to future deep space exploration, but also because it has allowed investigators to ask questions about how gravity impacts cell behavior here on Earth. In the 1980s, scientists designed and built the first rotating wall vessel, capable of mimicking the low shear environment found in space. This vessel has since been used to investigate growth of both microorganisms and human tissue cells in low shear modeled microgravity conditions. Bacterial behavior has been shown to be altered both in space and under simulated microgravity conditions. In some cases, bacteria appear attenuated, whereas in others virulence is enhanced. This has consequences not only for manned spaceflight, but poses larger questions about the ability of bacteria to sense the world around them. By using the microgravity environment as a tool, we can exploit this phenomenon in the search for new therapeutics and preventatives against pathogenic bacteria for use both in space and on Earth. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. A Network Approach of Gene Co-expression in the Zea mays/Aspergillus flavus Pathosystem to Map Host/Pathogen Interaction Pathways.

    Science.gov (United States)

    Musungu, Bryan M; Bhatnagar, Deepak; Brown, Robert L; Payne, Gary A; OBrian, Greg; Fakhoury, Ahmad M; Geisler, Matt

    2016-01-01

    A gene co-expression network (GEN) was generated using a dual RNA-seq study with the fungal pathogen Aspergillus flavus and its plant host Zea mays during the initial 3 days of infection. The analysis deciphered novel pathways and mapped genes of interest in both organisms during the infection. This network revealed a high degree of connectivity in many of the previously recognized pathways in Z. mays such as jasmonic acid, ethylene, and reactive oxygen species (ROS). For the pathogen A. flavus , a link between aflatoxin production and vesicular transport was identified within the network. There was significant interspecies correlation of expression between Z. mays and A. flavus for a subset of 104 Z. mays , and 1942 A. flavus genes. This resulted in an interspecies subnetwork enriched in multiple Z. mays genes involved in the production of ROS. In addition to the ROS from Z. mays , there was enrichment in the vesicular transport pathways and the aflatoxin pathway for A. flavus . Included in these genes, a key aflatoxin cluster regulator, AflS, was found to be co-regulated with multiple Z. mays ROS producing genes within the network, suggesting AflS may be monitoring host ROS levels. The entire GEN for both host and pathogen, and the subset of interspecies correlations, is presented as a tool for hypothesis generation and discovery for events in the early stages of fungal infection of Z. mays by A. flavus .

  4. Targeting of insect epicuticular lipids by the entomopathogenic fungus Beauveria bassiana: hydrocarbon oxidation within the context of a host-pathogen interaction

    Science.gov (United States)

    Pedrini, Nicolás; Ortiz-Urquiza, Almudena; Huarte-Bonnet, Carla; Zhang, Shizhu; Keyhani, Nemat O.

    2013-01-01

    Broad host range entomopathogenic fungi such as Beauveria bassiana attack insect hosts via attachment to cuticular substrata and the production of enzymes for the degradation and penetration of insect cuticle. The outermost epicuticular layer consists of a complex mixture of non-polar lipids including hydrocarbons, fatty acids, and wax esters. Long chain hydrocarbons are major components of the outer waxy layer of diverse insect species, where they serve to protect against desiccation and microbial parasites, and as recognition molecules or as a platform for semiochemicals. Insect pathogenic fungi have evolved mechanisms for overcoming this barrier, likely with sets of lipid degrading enzymes with overlapping substrate specificities. Alkanes and fatty acids are substrates for a specific subset of fungal cytochrome P450 monooxygenases involved in insect hydrocarbon degradation. These enzymes activate alkanes by terminal oxidation to alcohols, which are further oxidized by alcohol and aldehyde dehydrogenases, whose products can enter β-oxidation pathways. B. bassiana contains at least 83 genes coding for cytochrome P450s (CYP), a subset of which are involved in hydrocarbon oxidation, and several of which represent new CYP subfamilies/families. Expression data indicated differential induction by alkanes and insect lipids and four CYP proteins have been partially characterized after heterologous expression in yeast. Gene knockouts revealed a phenotype for only one (cyp52X1) out of six genes examined to date. CYP52X1 oxidizes long chain fatty acids and participates in the degradation of specific epicuticular lipid components needed for breaching the insect waxy layer. Examining the hydrocarbon oxidizing CYP repertoire of pathogens involved in insect epicuticle degradation can lead to the characterization of enzymes with novel substrate specificities. Pathogen targeting may also represent an important co-evolutionary process regarding insect cuticular hydrocarbon synthesis. PMID:23422735

  5. Time-resolved quantitative proteome profiling of host-pathogen interactions: the response of Staphylococcus aureus RN1HG to internalisation by human airway epithelial cells.

    Science.gov (United States)

    Schmidt, Frank; Scharf, Sandra S; Hildebrandt, Petra; Burian, Marc; Bernhardt, Jörg; Dhople, Vishnu; Kalinka, Julia; Gutjahr, Melanie; Hammer, Elke; Völker, Uwe

    2010-08-01

    Staphylococcus aureus is a versatile gram-positive pathogen that gains increasing importance due to the rapid spreading of resistances. Functional genomics technologies can provide new insights into the adaptational network of this bacterium and its response to environmental challenges. While functional genomics technologies, including proteomics, have been extensively used to study these phenomena in shake flask cultures, studies of bacteria from in vivo settings lack behind. Particularly for proteomics studies, the major bottleneck is the lack of sufficient proteomic coverage for low numbers of cells. In this study, we introduce a workflow that combines a pulse-chase stable isotope labelling by amino acids in cell culture approach with high capacity cell sorting, on-membrane digestion, and high-sensitivity MS to detect and quantitatively monitor several hundred S. aureus proteins from a few million internalised bacteria. This workflow has been used in a proof-of-principle experiment to reveal changes in levels of proteins with a function in protection against oxidative damage and adaptation of cell wall synthesis in strain RN1HG upon internalisation by S9 human bronchial epithelial cells.

  6. Host-pathogen interactions in bovine mammary epithelial cells and HeLa cells by Staphylococcus aureus isolated from subclinical bovine mastitis.

    Science.gov (United States)

    Castilho, Ivana G; Dantas, Stéfani Thais Alves; Langoni, Hélio; Araújo, João P; Fernandes, Ary; Alvarenga, Fernanda C L; Maia, Leandro; Cagnini, Didier Q; Rall, Vera L M

    2017-08-01

    Staphylococcus aureus is a common pathogen that causes subclinical bovine mastitis due to several virulence factors. In this study, we analyzed S. aureus isolates collected from the milk of cows with subclinical mastitis that had 8 possible combinations of bap, icaA, and icaD genes, to determine their capacity to produce biofilm on biotic (bovine primary mammary epithelial cells and HeLa cells) and abiotic (polystyrene microplates) surfaces, and their ability to adhere to and invade these cells. We also characterized isolates for microbial surface components recognizing adhesive matrix molecules (MSCRAMM) and agr genes, and for their susceptibility to cefquinome sulfate in the presence of biofilm. All isolates adhered to and invaded both cell types, but invasion indexes were higher in bovine primary mammary epithelial cells. Using tryptic soy broth + 1% glucose on abiotic surfaces, 5 out of 8 isolates were biofilm producers, but only the bap + icaA + icaD + isolate was positive in Dulbecco's Modified Eagle's medium. The production of biofilm on biotic surfaces occurred only with this isolate and only on HeLa cells, because the invasion index for bovine primary mammary epithelial cells was too high, making it impossible to use these cells in this assay. Of the 5 biofilm producers in tryptic soy broth + 1% glucose, 4 presented with the bap/fnbA/clfA/clfB/eno/fib/ebpS combination, and all were protected from cefquinome sulfate. We found no predominance of any agr group. The high invasive potential of S. aureus made it impossible to observe biofilm in bovine primary mammary epithelial cells, and we concluded that cells with lower invasion rates, such as HeLa cells, were more appropriate for this assay. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  7. Effect of dietary capsicum and turmeric oleoresins on host-pathogen interaction in experimental necrotic enteritis in three commercial broiler chicken breeds

    Science.gov (United States)

    Necrotic enteritis (NE) is among the most economically important enteric diseases affecting the poultry industry worldwide. In an effort to develop alternatives to antibiotics strategies to reduce the negative impact of NE to gut health, we investigated the efficacy of dietary phytonutrient mixture...

  8. A new early-warning system for stripe rust affecting wheat and triticale: Host-pathogen interactions under different environmental conditions

    DEFF Research Database (Denmark)

    Rodriguez Algaba, Julian; Justesen, Annemarie Fejer; Hovmøller, Mogens Støvring

    resistant it was susceptible under field conditions in March 2012. All Pst isolates from Tulus, obtained from multiple locations, were identified as the ‘Kranich’-race, and were avirulent on Tulus under experimental conditions. In May and June 2012 Tulus recovered on a country-wide scale and was resistant...

  9. Is AIBO Real? Understanding Children's Beliefs about and Behavioral Interactions with Anthropomorphic Toys

    Science.gov (United States)

    Francis, Andrea; Mishra, Punya

    2009-01-01

    Interactive toys for children are becoming more popular for both play and educational purposes, yet an understanding of the dependent measures used to study such interactions has not yet been explored. This study takes advantage of the idea that robotic animals exhibit both living and pretend qualities, and are therefore ideal for studying…

  10. Adaptive interaction a utility maximization approach to understanding human interaction with technology

    CERN Document Server

    Payne, Stephen J

    2013-01-01

    This lecture describes a theoretical framework for the behavioural sciences that holds high promise for theory-driven research and design in Human-Computer Interaction. The framework is designed to tackle the adaptive, ecological, and bounded nature of human behaviour. It is designed to help scientists and practitioners reason about why people choose to behave as they do and to explain which strategies people choose in response to utility, ecology, and cognitive information processing mechanisms. A key idea is that people choose strategies so as to maximise utility given constraints. The frame

  11. Use of isotopes for research and control of vectors of animal diseases, host-pathogen relationships and the environmental impact of control procedures

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1979-08-15

    Full text: To cope with the world-wide problems of famine, malnutrition and environmental pollution it is imperative that all techniques and resources for the protection of animals and plants be utilized. As an example, nagana alone (animal trypanosomiasis) profoundly affects socioeconomic development in Africa. Its vector, the tsetse fly, is widespread and prevents agricultural development over much of the more than 7 million square kilometres where it is present. The need to control this disease has been emphasized by a mandate from the 1974 World Food Conference of the United Nations. If this disease alone could be eliminated, the cattle population could be increased by at least 120 million head with a resultant yearly increase in meat production of 1.5 million tons having a value totalling 750 million US dollars. The symposium was convened to discuss the various research and control aspects of nagana and related diseases and was the first of its kind to be convened by the sponsoring organizations The symposium amply demonstrated the value and usefulness of isotopes in the research and control of vectors of animal diseases, the elucidation of host-pathogen relationships and the degradation of pesticides. The symposium received an enthusiastic response, reflected in the large number of papers presented, which covered a variety of topics, including the sterile insect technique (SIT) as applied to tsetse flies. Several papers were presented covering its different aspects such as mass-rearing, sterility induction, ecology, behaviour and computer modelling. Other topics emphasized were pathogenesis and immunology of vector borne diseases such as trypanosomiasis, anaplasmosis, babesiosis and leishmaniasis. Also included were presentations on insect repellents and the biotransformation and degradation of labelled pesticides. The technical sessions began with 3 review papers, one on the FAO Animal Health Division's field research on tsetse flies, the second on the

  12. Use of isotopes for research and control of vectors of animal diseases, host-pathogen relationships and the environmental impact of control procedures

    International Nuclear Information System (INIS)

    1979-01-01

    Full text: To cope with the world-wide problems of famine, malnutrition and environmental pollution it is imperative that all techniques and resources for the protection of animals and plants be utilized. As an example, nagana alone (animal trypanosomiasis) profoundly affects socioeconomic development in Africa. Its vector, the tsetse fly, is widespread and prevents agricultural development over much of the more than 7 million square kilometres where it is present. The need to control this disease has been emphasized by a mandate from the 1974 World Food Conference of the United Nations. If this disease alone could be eliminated, the cattle population could be increased by at least 120 million head with a resultant yearly increase in meat production of 1.5 million tons having a value totalling 750 million US dollars. The symposium was convened to discuss the various research and control aspects of nagana and related diseases and was the first of its kind to be convened by the sponsoring organizations The symposium amply demonstrated the value and usefulness of isotopes in the research and control of vectors of animal diseases, the elucidation of host-pathogen relationships and the degradation of pesticides. The symposium received an enthusiastic response, reflected in the large number of papers presented, which covered a variety of topics, including the sterile insect technique (SIT) as applied to tsetse flies. Several papers were presented covering its different aspects such as mass-rearing, sterility induction, ecology, behaviour and computer modelling. Other topics emphasized were pathogenesis and immunology of vector borne diseases such as trypanosomiasis, anaplasmosis, babesiosis and leishmaniasis. Also included were presentations on insect repellents and the biotransformation and degradation of labelled pesticides. The technical sessions began with 3 review papers, one on the FAO Animal Health Division's field research on tsetse flies, the second on the

  13. Molecular Understanding of Fullerene - Electron Donor Interactions in Organic Solar Cells

    KAUST Repository

    Ryno, Sean

    2016-09-13

    Organic solar cells hold promise of providing low-cost, renewable power generation, with current devices providing up to 13% power conversion efficiency. The rational design of more performant systems requires an in-depth understanding of the interactions between the electron donating and electron accepting materials within the active layers of these devices. Here, we explore works that give insight into the intermolecular interactions between electron donors and electron acceptors, and the impact of molecular orientations and environment on these interactions. We highlight, from a theoretical standpoint, the effects of intermolecular interactions on the stability of charge carriers at the donor/acceptor interface and in the bulk and how these interactions influence the nature of the charge transfer states as wells as the charge separation and charge transport processes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. ShapeShop: Towards Understanding Deep Learning Representations via Interactive Experimentation

    Energy Technology Data Exchange (ETDEWEB)

    Hohman, Frederick M.; Hodas, Nathan O.; Chau, Duen Horng

    2017-05-30

    Deep learning is the driving force behind many recent technologies; however, deep neural networks are often viewed as “black-boxes” due to their internal complexity that is hard to understand. Little research focuses on helping people explore and understand the relationship between a user’s data and the learned representations in deep learning models. We present our ongoing work, ShapeShop, an interactive system for visualizing and understanding what semantics a neural network model has learned. Built using standard web technologies, ShapeShop allows users to experiment with and compare deep learning models to help explore the robustness of image classifiers.

  15. ShapeShop: Towards Understanding Deep Learning Representations via Interactive Experimentation.

    Science.gov (United States)

    Hohman, Fred; Hodas, Nathan; Chau, Duen Horng

    2017-05-01

    Deep learning is the driving force behind many recent technologies; however, deep neural networks are often viewed as "black-boxes" due to their internal complexity that is hard to understand. Little research focuses on helping people explore and understand the relationship between a user's data and the learned representations in deep learning models. We present our ongoing work, ShapeShop, an interactive system for visualizing and understanding what semantics a neural network model has learned. Built using standard web technologies, ShapeShop allows users to experiment with and compare deep learning models to help explore the robustness of image classifiers.

  16. Recent advances in understanding Epstein-Barr virus [version 1; referees: 4 approved

    Directory of Open Access Journals (Sweden)

    Brent A. Stanfield

    2017-03-01

    Full Text Available Epstein-Barr virus (EBV is a common human herpes virus known to infect the majority of the world population. Infection with EBV is often asymptomatic but can manifest in a range of pathologies from infectious mononucleosis to severe cancers of epithelial and lymphocytic origin. Indeed, in the past decade, EBV has been linked to nearly 10% of all gastric cancers. Furthermore, recent advances in high-throughput next-generation sequencing and the development of humanized mice, which effectively model EBV pathogenesis, have led to a wealth of knowledge pertaining to strain variation and host-pathogen interaction. This review highlights some recent advances in our understanding of EBV biology, focusing on new findings on the early events of infection, the role EBV plays in gastric cancer, new strain variation, and humanized mouse models of EBV infection.

  17. Developing Social Interaction and Understanding in Individuals with Autism Spectrum Disorder: A Groupwork Intervention

    Science.gov (United States)

    MacKay, Tommy; Knott, Fiona; Dunlop, Aline-Wendy

    2007-01-01

    Background: Difficulties with social interaction and understanding lie at the heart of the communication disorder that characterises the autism spectrum. This study sought to improve social communication for individuals with autism spectrum disorder (ASD) by means of a groupwork intervention focusing on social and emotional perspective-taking,…

  18. An Understanding Information Management System for a Real-Time Interactive Distance Education Environment

    Science.gov (United States)

    He, Aiguo

    2009-01-01

    A real-time interactive distance lecture is a joint work that should be accomplished by the effort of the lecturer and his students in remote sites. It is important for the lecturer to get understanding information from the students which cannot be efficiently collected by only using video/audio channels between the lecturer and the students. This…

  19. Understanding Motivations and User Interests as Antecedents for Different Interaction Forms in Online Communities

    DEFF Research Database (Denmark)

    Jacobsen, Lina; Sørensen, Bjarne Taulo; Tudoran, Ana Alina

    This study contributes to the understanding of online user communities as a potential source of innovation. That would require an interest from users in interacting in such communities. In order to establish interaction, users must provide as well as consume information. However, depending...... on the innovation task, one may be more important than the other. It is therefore important to understand, how companies can increase user willingness to engage in these different interaction forms. This study investigates the influence of various motivation factors and user interests on intention to provide...... or consume information in online food communities. A survey was conducted among 1009 respondents followed by analysis based on Structural Equation Modelling. Results revealed the effect of motivation factors to be stronger than basic consumer interests indicating that companies can influence the intended...

  20. Understanding consumer motivations for interacting in online food communities – potential for innovation

    DEFF Research Database (Denmark)

    Jacobsen, Lina; Sørensen, Bjarne Taulo; Tudoran, Ana Alina

    This study contributes to the understanding of online user communities as a potential source of innovation. That would require an interest from users in interacting in such communities. In order to establish interaction, users must provide as well as consume information. However, depending...... on the innovation task, one may be more important than the other. It is therefore important to understand, how companies can increase user willingness to engage in these different interaction forms. This study investigates the influence of various motivation factors and user interests on intention to provide...... or consume information in online food communities. A survey was conducted among 1009 respondents followed by analysis based on Structural Equation Modelling. Results revealed the effect of motivation factors to be stronger than basic consumer interests indicating that companies can influence the intended...

  1. Understanding Situated Social Interactions: A Case Study of Public Places in the City

    DEFF Research Database (Denmark)

    Paay, Jeni; Kjeldskov, Jesper

    2008-01-01

    these and their situated interactions. In response, this paper addresses the challenge of informing design of mobile services for fostering social connections by using the concept of place for studying and understanding peoples’ social activities in a public built environment. We present a case study of social experience...... of a physical place providing an understanding of peoples’ situated social interactions in public places of the city derived through a grounded analysis of small groups of friends socialising out on the town. Informed by this, we describe the design and evaluation of a mobile prototype system facilitating......Ubiquitous and mobile computer technologies are increasingly being appropriated to facilitate people’s social life outside the work domain. Designing such social and collaborative technologies requires an understanding of peoples’ physical and social context, and the interplay between...

  2. The interactions between CdTe quantum dots and proteins: understanding nano-bio interface

    Directory of Open Access Journals (Sweden)

    Shreeram S. Joglekar

    2017-01-01

    Full Text Available Despite remarkable developments in the nanoscience, relatively little is known about the physical (electrostatic interactions of nanoparticles with bio macromolecules. These interactions can influence the properties of both nanoparticles and the bio-macromolecules. Understanding this bio-interface is a prerequisite to utilize both nanoparticles and biomolecules for bioengineering. In this study, luminescent, water soluble CdTe quantum dots (QDs capped with mercaptopropionic acid (MPA were synthesized by organometallic method and then interaction between nanoparticles (QDs and three different types of proteins (BSA, Lysozyme and Hemoglobin were investigated by fluorescence spectroscopy at pH= 7.4. Based on fluorescence quenching results, Stern-Volmer quenching constant (Ksv, binding constant (Kq and binding sites (n for proteins were calculated. The results show that protein structure (e.g.,globular, metalloprotein, etc. has a significant role in Protein-Quantum dots interactions and each type of protein influence physicochemical properties of Quantum dots differently.

  3. Fuel-coolant interaction (FCI) phenomena in reactor safety. Current understanding and future research needs

    Energy Technology Data Exchange (ETDEWEB)

    Speis, T.P. [Maryland Univ., College Park, MD (United States); Basu, S.

    1998-01-01

    This paper gives an account of the current understanding of fuel-coolant interaction (FCI) phenomena in the context of reactor safety. With increased emphasis on accident management and with emerging in-vessel core melt retention strategies for advanced light water reactor (ALWR) designs, recent interest in FCI has broadened to include an evaluation of potential threats to the integrity of reactor vessel lower head and ex-vessel structural support, as well as the role of FCI in debris quenching and coolability. The current understanding of FCI with regard to these issues is discussed, and future research needs to address the issues from a risk perspective are identified. (author)

  4. DP 71 AND BETA DYSTROGLYCAN INTERACTION: A MOLECULAR MODELING APPROACH TO UNDERSTAND DUCHENNE MUSCULAR DYSTROPHY

    Directory of Open Access Journals (Sweden)

    Simanti Bhattacharya,

    2013-12-01

    Full Text Available Dp 71 is the most prevalent and widely expressed non muscle isoform of dystrophin (Dp and its mutations are associated with Duchenne muscular dystrophy, a severe form of muscular disorder. Dp 71 deviates from the canonical Dp by means of its truncated N terminal which also has abolished certain amino acids that comprise WW domain in the canonical form. This WW domain is very crucial for Dp’s interaction with partner proteins to establish a bridge between extra cellular matrices and cellular cytoskeleton. In our current study we have employed molecular modeling technique to understand the structural architecture of the N terminal region of Dp 71 and its deviation from the canonical form. We have further extended our studies to analyze the interaction probabilities between Dp 71 and β-DG applying molecular docking. Our studies for the first time have revealed that in spite of the underlying differences in terms of amino acids and structural organization, Dp 71 can interact with β-DG with its N terminal region which shares the similar molecular surface with the canonical form of Dp. These findings have opened up a platform to investigate the molecular interactions, spatio temporal orientations of the amino acids of Dp 71 and β-DG to understand the onset of DMD in much more greater detail

  5. Effect of science magic applied in interactive lecture demonstrations on conceptual understanding

    Science.gov (United States)

    Taufiq, Muhammad; Suhandi, Andi; Liliawati, Winny

    2017-08-01

    Research about the application of science magic-assisting Interactive Lecture Demonstrations (ILD) has been conducted. This research is aimed at providing description about the comparison of the improvement of the conceptual understanding of lesson on pressure between students who receive physics lesson through science magic-assisting ILD and students who receive physics lesson through ILD without science magic. This research used a quasi-experiment methods with Control Group Pretest-Posttest Design. The subject of the research is all students of class VIII in one of MTs (Islamic junior high school) in Pekalongan. Research samples were selected using random sampling technique. Data about students' conceptual understanding was collected using test instrument of conceptual understanding in the form of multiple choices. N-gain average calculation was performed in order to determine the improvement of students' conceptual understanding. The result of the research shows that conceptual understanding of students on lesson about pressure who received lesson with ILD using science magic is higher than students who received lesson with ILD without science magic . Therefore, the conclusion is that the application of science magic ILD is more effective to improve the conceptual understanding of lesson on pressure.

  6. Babesia spp. and Anaplasma phagocytophilum in questing ticks, ticks parasitizing rodents and the parasitized rodents--analyzing the host-pathogen-vector interface in a metropolitan area.

    Science.gov (United States)

    Silaghi, Cornelia; Woll, Dietlinde; Hamel, Dietmar; Pfister, Kurt; Mahling, Monia; Pfeffer, Martin

    2012-09-05

    The aims of this study were to evaluate the host-tick-pathogen interface of Babesia spp. and Anaplasma phagocytophilum in restored areas in both questing and host-attached Ixodes ricinus and Dermacentor reticulatus and their small mammalian hosts. Questing ticks were collected from 5 sites within the city of Leipzig, Germany, in 2009. Small mammals were trapped at 3 of the 5 sites during 2010 and 2011. DNA extracts of questing and host-attached I. ricinus and D. reticulatus and of several tissue types of small mammals (the majority bank voles and yellow-necked mice), were investigated by PCR followed by sequencing for the occurrence of DNA of Babesia spp. and by real-time PCR for A. phagocytophilum. A selected number of samples positive for A. phagocytophilum were further investigated for variants of the partial 16S rRNA gene. Co-infection with Rickettsia spp. in the questing ticks was additionally investigated. 4.1% of questing I. ricinus ticks, but no D. reticulatus, were positive for Babesia sp. and 8.7% of I. ricinus for A. phagocytophilum. Sequencing revealed B. microti, B. capreoli and Babesia spp. EU1 in Leipzig and sequence analysis of the partial 16S RNA gene of A. phagocytophilum revealed variants either rarely reported in human cases or associated with cervid hosts. The statistical analysis revealed significantly less ticks infected with A. phagocytophilum in a city park in Leipzig as compared to the other sampling sites. A. phagocytophilum-DNA was detected in 2 bank voles, DNA of B. microti in 1 striped field-mouse and of Babesia sp. EU1 in the skin tissue of a mole. Co-infections were detected. Our results show the involvement of small mammals in the natural endemic cycles of tick-borne pathogens. A more thorough understanding of the interactions of ticks, pathogens and hosts is the essential basis for effective preventive control measures.

  7. Babesia spp. and Anaplasma phagocytophilum in questing ticks, ticks parasitizing rodents and the parasitized rodents – Analyzing the host-pathogen-vector interface in a metropolitan area

    Directory of Open Access Journals (Sweden)

    Silaghi Cornelia

    2012-09-01

    Full Text Available Abstract Background The aims of this study were to evaluate the host-tick-pathogen interface of Babesia spp. and Anaplasma phagocytophilum in restored areas in both questing and host-attached Ixodes ricinus and Dermacentor reticulatus and their small mammalian hosts. Methods Questing ticks were collected from 5 sites within the city of Leipzig, Germany, in 2009. Small mammals were trapped at 3 of the 5 sites during 2010 and 2011. DNA extracts of questing and host-attached I. ricinus and D. reticulatus and of several tissue types of small mammals (the majority bank voles and yellow-necked mice, were investigated by PCR followed by sequencing for the occurrence of DNA of Babesia spp. and by real-time PCR for A. phagocytophilum. A selected number of samples positive for A. phagocytophilum were further investigated for variants of the partial 16S rRNA gene. Co-infection with Rickettsia spp. in the questing ticks was additionally investigated. Results 4.1% of questing I. ricinus ticks, but no D. reticulatus, were positive for Babesia sp. and 8.7% of I. ricinus for A. phagocytophilum. Sequencing revealed B. microti, B. capreoli and Babesia spp. EU1 in Leipzig and sequence analysis of the partial 16S RNA gene of A. phagocytophilum revealed variants either rarely reported in human cases or associated with cervid hosts. The statistical analysis revealed significantly less ticks infected with A. phagocytophilum in a city park in Leipzig as compared to the other sampling sites. A. phagocytophilum-DNA was detected in 2 bank voles, DNA of B. microti in 1 striped field-mouse and of Babesia sp. EU1 in the skin tissue of a mole. Co-infections were detected. Conclusion Our results show the involvement of small mammals in the natural endemic cycles of tick-borne pathogens. A more thorough understanding of the interactions of ticks, pathogens and hosts is the essential basis for effective preventive control measures.

  8. Babesia spp. and Anaplasma phagocytophilum in questing ticks, ticks parasitizing rodents and the parasitized rodents – Analyzing the host-pathogen-vector interface in a metropolitan area

    Science.gov (United States)

    2012-01-01

    Background The aims of this study were to evaluate the host-tick-pathogen interface of Babesia spp. and Anaplasma phagocytophilum in restored areas in both questing and host-attached Ixodes ricinus and Dermacentor reticulatus and their small mammalian hosts. Methods Questing ticks were collected from 5 sites within the city of Leipzig, Germany, in 2009. Small mammals were trapped at 3 of the 5 sites during 2010 and 2011. DNA extracts of questing and host-attached I. ricinus and D. reticulatus and of several tissue types of small mammals (the majority bank voles and yellow-necked mice), were investigated by PCR followed by sequencing for the occurrence of DNA of Babesia spp. and by real-time PCR for A. phagocytophilum. A selected number of samples positive for A. phagocytophilum were further investigated for variants of the partial 16S rRNA gene. Co-infection with Rickettsia spp. in the questing ticks was additionally investigated. Results 4.1% of questing I. ricinus ticks, but no D. reticulatus, were positive for Babesia sp. and 8.7% of I. ricinus for A. phagocytophilum. Sequencing revealed B. microti, B. capreoli and Babesia spp. EU1 in Leipzig and sequence analysis of the partial 16S RNA gene of A. phagocytophilum revealed variants either rarely reported in human cases or associated with cervid hosts. The statistical analysis revealed significantly less ticks infected with A. phagocytophilum in a city park in Leipzig as compared to the other sampling sites. A. phagocytophilum-DNA was detected in 2 bank voles, DNA of B. microti in 1 striped field-mouse and of Babesia sp. EU1 in the skin tissue of a mole. Co-infections were detected. Conclusion Our results show the involvement of small mammals in the natural endemic cycles of tick-borne pathogens. A more thorough understanding of the interactions of ticks, pathogens and hosts is the essential basis for effective preventive control measures. PMID:22950642

  9. Recent progress in understanding host immune response to Avian Coccidiosis: Th1 and Th17 responses

    Science.gov (United States)

    Host-pathogen interaction leading to protection against coccidiosis is complex, involving many aspects of innate and adaptive immunity to intracellular parasites. The etiologic agent of avian coccidiosis is Eimeria, a genus of eukaryotic obligate intracellular parasites belonging to the phylum Apico...

  10. Network Understanding of Herb Medicine via Rapid Identification of Ingredient-Target Interactions

    Science.gov (United States)

    Zhang, Hai-Ping; Pan, Jian-Bo; Zhang, Chi; Ji, Nan; Wang, Hao; Ji, Zhi-Liang

    2014-01-01

    Today, herb medicines have become the major source for discovery of novel agents in countermining diseases. However, many of them are largely under-explored in pharmacology due to the limitation of current experimental approaches. Therefore, we proposed a computational framework in this study for network understanding of herb pharmacology via rapid identification of putative ingredient-target interactions in human structural proteome level. A marketing anti-cancer herb medicine in China, Yadanzi (Brucea javanica), was chosen for mechanistic study. Total 7,119 ingredient-target interactions were identified for thirteen Yadanzi active ingredients. Among them, about 29.5% were estimated to have better binding affinity than their corresponding marketing drug-target interactions. Further Bioinformatics analyses suggest that simultaneous manipulation of multiple proteins in the MAPK signaling pathway and the phosphorylation process of anti-apoptosis may largely answer for Yadanzi against non-small cell lung cancers. In summary, our strategy provides an efficient however economic solution for systematic understanding of herbs' power.

  11. Children's Aesthetic Understanding of Photographic Art and the Quality of Art-Related Parent-Child Interactions

    Science.gov (United States)

    Szechter, Lisa E.; Liben, Lynn S.

    2007-01-01

    This research was designed to examine the quality of children's aesthetic understanding of photographs, observe social interactions between parents and children in this aesthetic domain, and study whether qualitatively different dyadic interactions were associated with children's own aesthetic understanding. Parents and children (7-13 years; 40…

  12. Understanding small biomolecule-biomaterial interactions: a review of fundamental theoretical and experimental approaches for biomolecule interactions with inorganic surfaces.

    Science.gov (United States)

    Costa, Dominique; Garrain, Pierre-Alain; Baaden, Marc

    2013-04-01

    Interactions between biomolecules and inorganic surfaces play an important role in natural environments and in industry, including a wide variety of conditions: marine environment, ship hulls (fouling), water treatment, heat exchange, membrane separation, soils, mineral particles at the earth's surface, hospitals (hygiene), art and buildings (degradation and biocorrosion), paper industry (fouling) and more. To better control the first steps leading to adsorption of a biomolecule on an inorganic surface, it is mandatory to understand the adsorption mechanisms of biomolecules of several sizes at the atomic scale, that is, the nature of the chemical interaction between the biomolecule and the surface and the resulting biomolecule conformations once adsorbed at the surface. This remains a challenging and unsolved problem. Here, we review the state of art in experimental and theoretical approaches. We focus on metallic biomaterial surfaces such as TiO(2) and stainless steel, mentioning some remarkable results on hydroxyapatite. Experimental techniques include atomic force microscopy, surface plasmon resonance, quartz crystal microbalance, X-ray photoelectron spectroscopy, fluorescence microscopy, polarization modulation infrared reflection absorption spectroscopy, sum frequency generation and time of flight secondary ion mass spectroscopy. Theoretical models range from detailed quantum mechanical representations to classical forcefield-based approaches. Copyright © 2012 Wiley Periodicals, Inc.

  13. Understanding Consumer Interaction on Instagram: The Role of Satisfaction, Hedonism, and Content Characteristics.

    Science.gov (United States)

    Casaló, Luis V; Flavián, Carlos; Ibáñez-Sánchez, Sergio

    2017-06-01

    The increasing relevance of Instagram and its growing adoption among top brands suggest an effort to better understand consumers' behaviors within this context. The purpose of this study is to examine the role of perceived hedonism and satisfaction in determining consumers' intentions to interact and their actual interaction behaviors (the number of likes, by tapping a heart icon, and comments) in a brand's official Instagram account. Also, we investigate the effect of consumer perceptions about the characteristics of the content generated in the account (perceived originality, quantity, and quality) on their perceived hedonism and satisfaction. Data were collected in two stages from 808 members of a fashion brand's official Instagram account. First, participants answered an online questionnaire to evaluate their perceptions, satisfaction, and interaction intentions. Second, 1 month later, we measure the number of likes and comments done by each participant in the brand's official Instagram account during that month. Using partial least squares to analyze the data, perceived hedonism is found to affect both satisfaction and the intention to interact in Instagram, which in turn influences actual behavior. Besides, perceived originality is the most relevant content characteristic to develop perceived hedonism. These findings offer managers a general vision of consumers' behaviors on Instagram, highlighting the importance of hedonism to create a satisfactory experience.

  14. A Century of Plant Pathology: A Retrospective View on Understanding Host-Parasite Interactions.

    Science.gov (United States)

    Keen, N T

    2000-09-01

    ▪ Abstract  The twentieth century has been productive for the science of plant pathology and the field of host-parasite interactions-both in understanding how pathogens and plant defense work and in developing more effective means of disease control. Early in the twentieth century, plant pathology adopted a philosophy that encouraged basic scientific investigation of pathogens and disease defense. That philosophy led to the strategy of developing disease-resistant plants as a prima facie disease-control measure-and in the process saved billions of dollars and avoided the use of tons of pesticides. Plant pathology rapidly adopted molecular cloning and its spin-off technologies, and these have fueled major advances in our basic understanding of plant diseases. This knowledge and the development of efficient technologies for producing transgenic plants convey optimism that plant diseases will be more efficiently controlled in the twenty-first century.

  15. A Diagrammatic Approach to Understanding Complex Eco-Social Interactions in Kathmandu, Nepal

    Directory of Open Access Journals (Sweden)

    R. Cynthia. Neudoerffer

    2005-12-01

    Full Text Available As part of developing an international network of community-based ecosystem approaches to health, a project was undertaken in a densely populated and socio-economically diverse area of Kathmandu, Nepal. Drawing on hundreds of pages of narrative reports based on surveys, interviews, secondary data, and focus groups by trained Nepalese facilitators, the authors created systemic depictions of relationships between multiple stakeholder groups, ecosystem health, and human health. These were then combined to examine interactions among stakeholders, activities, concerns, perceived needs, and resource states (ecosystem health indicators. These qualitative models have provided useful heuristics for both community members and research scholars to understand the eco-social systems in which they live; many of the strategies developed by the communities and researchers to improve health intuitively drew on this systemic understanding. The diagrams enabled researchers and community participants to explicitly examine relationships and conflicts related to health and environmental issues in their community.

  16. The Interaction of Procedural Skill, Conceptual Understanding and Working Memory in Early Mathematics Achievement

    Directory of Open Access Journals (Sweden)

    Camilla Gilmore

    2017-12-01

    Full Text Available Large individual differences in children’s mathematics achievement are observed from the start of schooling. Previous research has identified three cognitive skills that are independent predictors of mathematics achievement: procedural skill, conceptual understanding and working memory. However, most studies have only tested independent effects of these factors and failed to consider moderating effects. We explored the procedural skill, conceptual understanding and working memory capacity of 75 children aged 5 to 6 years as well as their overall mathematical achievement. We found that, not only were all three skills independently associated with mathematics achievement, but there was also a significant interaction between them. We found that levels of conceptual understanding and working memory moderated the relationship between procedural skill and mathematics achievement such that there was a greater benefit of good procedural skill when associated with good conceptual understanding and working memory. Cluster analysis also revealed that children with equivalent levels of overall mathematical achievement had differing strengths and weaknesses across these skills. This highlights the importance of considering children’s skill profile, rather than simply their overall achievement.

  17. Aspergillus fumigatus in cystic fibrosis: An update on immune interactions and molecular diagnostics in allergic bronchopulmonary aspergillosis.

    Science.gov (United States)

    Carsin, A; Romain, T; Ranque, S; Reynaud-Gaubert, M; Dubus, J-C; Mège, J-L; Vitte, J

    2017-11-01

    A wide spectrum of pathological conditions may result from the interaction of Aspergillus fumigatus and the immune system of its human host. Allergic bronchopulmonary aspergillosis is one of the most severe A. fumigatus-related diseases due to possible evolution toward pleuropulmonary fibrosis and respiratory failure. Allergic bronchopulmonary aspergillosis occurs almost exclusively in cystic fibrosis or asthmatic patients. An estimated 8%-10% of patients with cystic fibrosis experience this condition. The diagnosis of allergic bronchopulmonary aspergillosis relies on criteria first established in 1977. Progress in the understanding of host-pathogen interactions in A. fumigatus and patients with cystic fibrosis and the ongoing validation of novel laboratory tools concur to update and improve the diagnosis of allergic bronchopulmonary aspergillosis. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

  18. Post-genomic approaches to understanding interactions between fungi and their environment.

    Science.gov (United States)

    de Vries, Ronald P; Benoit, Isabelle; Doehlemann, Gunther; Kobayashi, Tetsuo; Magnuson, Jon K; Panisko, Ellen A; Baker, Scott E; Lebrun, Marc-Henri

    2011-06-01

    Fungi inhabit every natural and anthropogenic environment on Earth. They have highly varied life-styles including saprobes (using only dead biomass as a nutrient source), pathogens (feeding on living biomass), and symbionts (co-existing with other organisms). These distinctions are not absolute as many species employ several life styles (e.g. saprobe and opportunistic pathogen, saprobe and mycorrhiza). To efficiently survive in these different and often changing environments, fungi need to be able to modify their physiology and in some cases will even modify their local environment. Understanding the interaction between fungi and their environments has been a topic of study for many decades. However, recently these studies have reached a new dimension. The availability of fungal genomes and development of post-genomic technologies for fungi, such as transcriptomics, proteomics and metabolomics, have enabled more detailed studies into this topic resulting in new insights. Based on a Special Interest Group session held during IMC9, this paper provides examples of the recent advances in using (post-)genomic approaches to better understand fungal interactions with their environments.

  19. Effect of Collaborative Learning in Interactive Lecture Demonstrations (ILD on Student Conceptual Understanding of Motion Graphs

    Directory of Open Access Journals (Sweden)

    Erees Queen B. Macabebe

    2017-04-01

    Full Text Available To assess effectively the influence of peer discussion in understandingconcepts, and to evaluate if the conceptual understanding through Interactive Lecture Demonstrations (ILD and collaborative learning can be translated to actual situations, ten (10 questions on human and carts in motion were presented to 151 university students comprising mostly of science majors but of different year levels. Individual and group predictions were conducted to assess the students’ pre-conceptual understanding of motion graphs. During the ILD, real-time motion graphs were obtained and analysed after each demonstration and an assessment that integrates the ten situations into two scenarios was given to evaluate the conceptual understanding of the students. Collaborative learning produced a positive effect on the prediction scores of the students and the ILD with real-time measurement allowed the students to validate their prediction. However, when the given situations were incorporated to create a scenario, it posted a challenge to the students. The results of this activity identified the area where additional instruction and emphasis is necessary.

  20. Understanding Plant-Microbe Interactions for Phytoremediation of Petroleum-Polluted Soil

    Science.gov (United States)

    Nie, Ming; Wang, Yijing; Yu, Jiayi; Xiao, Ming; Jiang, Lifen; Yang, Ji; Fang, Changming; Chen, Jiakuan; Li, Bo

    2011-01-01

    at these stages. The information provided by this study enhances our understanding of the effects of petroleum pollution on plant-microbe interactions and the roles of these interactions in the phytoremediation of petroleum-polluted soil. PMID:21437257

  1. Understanding and Resolving Failures in Human-Robot Interaction: Literature Review and Model Development

    Directory of Open Access Journals (Sweden)

    Shanee Honig

    2018-06-01

    Full Text Available While substantial effort has been invested in making robots more reliable, experience demonstrates that robots operating in unstructured environments are often challenged by frequent failures. Despite this, robots have not yet reached a level of design that allows effective management of faulty or unexpected behavior by untrained users. To understand why this may be the case, an in-depth literature review was done to explore when people perceive and resolve robot failures, how robots communicate failure, how failures influence people's perceptions and feelings toward robots, and how these effects can be mitigated. Fifty-two studies were identified relating to communicating failures and their causes, the influence of failures on human-robot interaction (HRI, and mitigating failures. Since little research has been done on these topics within the HRI community, insights from the fields of human computer interaction (HCI, human factors engineering, cognitive engineering and experimental psychology are presented and discussed. Based on the literature, we developed a model of information processing for robotic failures (Robot Failure Human Information Processing, RF-HIP, that guides the discussion of our findings. The model describes the way people perceive, process, and act on failures in human robot interaction. The model includes three main parts: (1 communicating failures, (2 perception and comprehension of failures, and (3 solving failures. Each part contains several stages, all influenced by contextual considerations and mitigation strategies. Several gaps in the literature have become evident as a result of this evaluation. More focus has been given to technical failures than interaction failures. Few studies focused on human errors, on communicating failures, or the cognitive, psychological, and social determinants that impact the design of mitigation strategies. By providing the stages of human information processing, RF-HIP can be used as a

  2. Using the tools of the trade to understand plasma interactions at Jupiter and Saturn

    Science.gov (United States)

    Kivelson, Margaret G.

    2017-10-01

    For more than half a century, we have been learning how magnetospheres work. Fluid motions and electromagnetic interactions combine to produce the plasma and field environment of a planet. Kinetic responses often control the dynamics. Initial descriptions of the terrestrial magnetosphere were often theoretical (e.g., Chapman and Ferraro, Dungey) before an explosion of spacecraft data provided an atlas of the system and its temporal variations. The basic structure and dynamics of the terrestrial magnetosphere are now largely understood. A different situation exists for the magnetospheres of Jupiter, Saturn, and their moons. Data acquired from spacecraft flybys or from orbit have characterized many aspects of these systems, but measurements are far more limited than at Earth both in space and in time. Even after Cassini’s mission to Saturn and Juno’s prime mission at Jupiter have ended, large regions in the plasma environments of these planets will remain unexplored. No monitors are available to characterize the upstream solar wind. Theory is challenged by the complexity introduced by dynamical effects of the planets’ rapid rotation and the unfamiliar parameter regimes governing interactions with their large moons. Simulation has come to the rescue, providing computational models designed to incorporate the effects of rotation or to describe moon-magnetosphere interactions. Yet simulations must be viewed with appropriate skepticism as they invariably require some compromise with reality. This talk will describe a symbiotic approach to understanding the dynamics of giant planet magnetospheres and the plasma interactions between magnetospheric plasma and large moons. Data acquired along a spacecraft trajectory are compared with values extracted from a virtual spacecraft moving through the same path in the simulation. If results are similar, we use the simulation to identify the processes responsible for puzzling aspects of the signatures. If results differ

  3. Understanding Urban Watersheds through Digital Interactive Maps, San Francisco Bay Area, California

    Science.gov (United States)

    Sowers, J. M.; Ticci, M. G.; Mulvey, P.

    2014-12-01

    Dense urbanization has resulted in the "disappearance" of many local creeks in urbanized areas surrounding the San Francisco Bay. Long reaches of creeks now flow in underground pipes. Municipalities and water agencies trying to reduce non-point-source pollution are faced with a public that cannot see and therefore does not understand the interconnected nature of the drainage system or its ultimate discharge to the bay. Since 1993, we have collaborated with the Oakland Museum, the San Francisco Estuary Institute, public agencies, and municipalities to create creek and watershed maps to address the need for public understanding of watershed concepts. Fifteen paper maps are now published (www.museumca.org/creeks), which have become a standard reference for educators and anyone working on local creek-related issues. We now present digital interactive creek and watershed maps in Google Earth. Four maps are completed covering urbanized areas of Santa Clara and Alameda Counties. The maps provide a 3D visualization of the watersheds, with cartography draped over the landscape in transparent colors. Each mapped area includes both Present and Past (circa 1800s) layers which can be clicked on or off by the user. The Present layers include the modern drainage network, watershed boundaries, and reservoirs. The Past layers include the 1800s-era creek systems, tidal marshes, lagoons, and other habitats. All data are developed in ArcGIS software and converted to Google Earth format. To ensure the maps are interesting and engaging, clickable icons pop-up provide information on places to visit, restoration projects, history, plants, and animals. Maps of Santa Clara Valley are available at http://www.valleywater.org/WOW.aspx. Maps of western Alameda County will soon be available at http://acfloodcontrol.org/. Digital interactive maps provide several advantages over paper maps. They are seamless within each map area, and the user can zoom in or out, and tilt, and fly over to explore

  4. Can understanding the packing of side chains improve the design of protein-protein interactions?

    Science.gov (United States)

    Zhou, Alice; O'Hern, Corey; Regan, Lynne

    2011-03-01

    With the long-term goal to improve the design of protein-protein interactions, we have begun extensive computational studies to understand how side-chains of key residues of binding partners geometrically fit together at protein-peptide interfaces, e.g. the tetratrico-peptide repeat protein and its cognate peptide). We describe simple atomic-scale models of hydrophobic dipeptides, which include hard-core repulsion, bond length and angle constraints, and Van der Waals attraction. By completely enumerating all minimal energy structures in these systems, we are able to reproduce important features of the probability distributions of side chain dihedral angles of hydrophic residues in the protein data bank. These results are the crucial first step in developing computational models that can predict the side chain conformations of residues at protein-peptide interfaces. CSO acknowledges support from NSF grant no. CMMT-1006527.

  5. Inflaming the brain: CRPS a model disease to understand neuroimmune interactions in chronic pain.

    Science.gov (United States)

    Linnman, C; Becerra, L; Borsook, D

    2013-06-01

    We review current concepts in CRPS from a neuroimaging perspective and point out topics and potential mechanisms that are suitable to be investigated in the next step towards understanding the pathophysiology of CRPS. We have outlined functional aspects of the syndrome, from initiating lesion via inflammatory mechanisms to CNS change and associated sickness behavior, with current evidence for up-regulation of immunological factors in CRPS, neuroimaging of systemic inflammation, and neuroimaging findings in CRPS. The initiation, maintenances and CNS targets implicated in CRPS and in the neuro-inflammatory reflex are discussed in terms of CRPS symptoms and recent preclinical studies. Potential avenues for investigating CRPS with PET and fMRI are described, along with roles of inflammation, treatment and behavior in CRPS. It is our hope that this outline will provoke discussion and promote further empirical studies on the interactions between central and peripheral inflammatory pathways manifest in CRPS.

  6. Arabidopsis thaliana - Myzus persicae interaction: shaping the understanding of plant defense against phloem-feeding aphids

    Directory of Open Access Journals (Sweden)

    Joe eLouis

    2013-07-01

    Full Text Available The phloem provides a unique niche for several organisms. Aphids are a large group of Hemipteran insects that utilize stylets present in their mouthparts to pierce sieve elements and drink large volumes of phloem sap. In addition, many aphids also vector viral diseases. Myzus persicae, commonly known as the green peach aphid (GPA, is an important pest of a large variety of plants that includes Arabidopsis thaliana. This review summarizes recent studies that have exploited the compatible interaction between Arabidopsis and GPA to understand the molecular and physiological mechanisms utilized by plants to control aphid infestation, as well as genes and mechanisms that contribute to susceptibility. In addition, recent efforts to identify aphid-delivered elicitors of plant defenses and novel aphid salivary components that facilitate infestation are also discussed.

  7. Children’s Third-Party Understanding of Communicative Interactions in a Foreign Language

    Directory of Open Access Journals (Sweden)

    Narges Afshordi

    2018-01-01

    Full Text Available Two studies explored young children’s understanding of the role of shared language in communication by investigating how monolingual English-speaking children interact with an English speaker, a Spanish speaker, and a bilingual experimenter who spoke both English and Spanish. When the bilingual experimenter spoke in Spanish or English to request objects, four-year-old children, but not three-year-olds, used her language choice to determine whom she addressed (e.g. requests in Spanish were directed to the Spanish speaker. Importantly, children used this cue – language choice – only in a communicative context. The findings suggest that by four years, monolingual children recognize that speaking the same language enables successful communication, even when that language is unfamiliar to them. Three-year-old children’s failure to make this distinction suggests that this capacity likely undergoes significant development in early childhood, although other capacities might also be at play.

  8. The Paracoccidioides cell wall: past and present layers towards understanding interaction with the host

    Directory of Open Access Journals (Sweden)

    Rosana ePuccia

    2011-12-01

    Full Text Available The cell wall of pathogenic fungi plays import roles in interaction with the host, so that its composition and structure may determine the course of infection. Here we present an overview of the current and past knowledge on the cell wall constituents of Paracoccidioides brasiliensis and P. lutzii. These are temperature-dependent dimorphic fungi that cause paracoccidioidomycosis, a systemic granulomatous and debilitating disease. Focus is given on cell wall carbohydrate and protein contents, their immune-stimulatory features, adhesion properties, drug target characteristics, and morphological phase specificity. We offer a journey towards the future understanding of the dynamic life that takes place in the cell wall and of the changes that it may suffer when living in the human host.

  9. Understanding the physical dynamics and ecological interactions in tidal stream energy environments

    Science.gov (United States)

    Fraser, Shaun; Williamson, Benjamin J.; Nikora, Vladimir; Scott, Beth E.

    2017-04-01

    Tidal stream energy devices are intended to operate in energetic physical environments characterised by high flows and extreme turbulence. These environments are often of ecological importance to a range of marine species. Understanding the physical dynamics and ecological interactions at fine scales in such sites is essential for device/array design and to understand environmental impacts. However, investigating fine scale characteristics requires high resolution field measurements which are difficult to attain and interpret, with data often confounded by interference related to turbulence. Consequently, field observations in tidal stream energy environments are limited and require the development of specialised analysis methods and so significant knowledge gaps are still present. The seabed mounted FLOWBEC platform is addressing these knowledge gaps using upward facing instruments to collect information from around marine energy infrastructure. Multifrequency and multibeam echosounder data provide detailed information on the distribution and interactions of biological targets, such as fish and diving seabirds, while simultaneously recording the scales and intensity of turbulence. Novel processing methodologies and instrument integration techniques have been developed which combine different data types and successfully separates signal from noise to reveal new evidence about the behaviour of mobile species and the structure of turbulence at all speeds of the tide and throughout the water column. Multiple platform deployments in the presence and absence of marine energy infrastructure reveal the natural characteristics of high energy sites, and enable the interpretation of the physical and biological impacts of tidal stream devices. These methods and results are relevant to the design and consenting of marine renewable energy technologies, and provide novel information on the use of turbulence for foraging opportunities in high energy sites by mobile species.

  10. Understanding interactions with the food environment: an exploration of supermarket food shopping routines in deprived neighbourhoods.

    Science.gov (United States)

    Thompson, Claire; Cummins, Steven; Brown, Tim; Kyle, Rosemary

    2013-01-01

    Despite a sustained academic interest in the environmental determinants of diet, relatively little is known about the ways in which individuals interact with their neighbourhood food environment and the use of its most important element, the supermarket. This qualitative study explores how residents of deprived neighbourhoods shop for food and how the supermarket environment influences their choices. Go-along interviews were conducted with 26 residents of Sandwell, a uniformly deprived metropolitan borough in the West Midlands, UK. Routine approaches to food shopping are characterised in terms of planning and reliance on the supermarket environment. Four distinct routines are identified: chaotic and reactive; working around the store; item-by-item; and restricted and budgeted. This suggests that residents of deprived neighbourhoods do not have uniform responses to food environments. Responses to supermarket environments appear to be mediated by levels of individual autonomy. A better understanding of how residents of deprived neighbourhoods interact with their food environment may help optimise environmental interventions aimed at improving physical access to food in these places. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Understanding Epistatic Interactions between Genes Targeted by Non-coding Regulatory Elements in Complex Diseases

    Directory of Open Access Journals (Sweden)

    Min Kyung Sung

    2014-12-01

    Full Text Available Genome-wide association studies have proven the highly polygenic architecture of complex diseases or traits; therefore, single-locus-based methods are usually unable to detect all involved loci, especially when individual loci exert small effects. Moreover, the majority of associated single-nucleotide polymorphisms resides in non-coding regions, making it difficult to understand their phenotypic contribution. In this work, we studied epistatic interactions associated with three common diseases using Korea Association Resource (KARE data: type 2 diabetes mellitus (DM, hypertension (HT, and coronary artery disease (CAD. We showed that epistatic single-nucleotide polymorphisms (SNPs were enriched in enhancers, as well as in DNase I footprints (the Encyclopedia of DNA Elements [ENCODE] Project Consortium 2012, which suggested that the disruption of the regulatory regions where transcription factors bind may be involved in the disease mechanism. Accordingly, to identify the genes affected by the SNPs, we employed whole-genome multiple-cell-type enhancer data which discovered using DNase I profiles and Cap Analysis Gene Expression (CAGE. Assigned genes were significantly enriched in known disease associated gene sets, which were explored based on the literature, suggesting that this approach is useful for detecting relevant affected genes. In our knowledge-based epistatic network, the three diseases share many associated genes and are also closely related with each other through many epistatic interactions. These findings elucidate the genetic basis of the close relationship between DM, HT, and CAD.

  12. How does money memorize social interactions? Understanding time-homogeneity in monetary systems

    Science.gov (United States)

    Braun, Dieter; Schmitt, Matthias; Schacker, Andreas

    2013-03-01

    Understanding how money shapes and memorizes our social interactions is central to modern life. There are many schools of thought on as to how monetary systems contribute to crises or boom/bust cycles and how monetary policy can try to avert them. We find that statistical physics gives a refreshing perspective. We analyze how credit mechanisms introduce non-locality and time-heterogeneity to the monetary memory. Motivated by an analogy to particle physics, locality and time-homogeneity can be imposed to monetary systems. As a result, a full reserve banking system is complemented with a bi-currency system of non-bank assets (``money'') and bank assets (``antimoney''). Payment can either be made by passing on money or by receiving antimoney. As a result, a free floating exchange rate between non-bank assets and bank assets is established. Interestingly, this monetary memory allows for credit creation by the simultaneous transfer of money and antimoney at a negotiated exchange rate. We analyze this novel mechanism of liquidity transfer in a model of random social interactions, yielding analytical results for all relevant distributions and the price of liquidity under the conditions of a fully transparent credit market.

  13. Teaching Photosynthesis in a Compulsory School Context. Students’ Reasoning, Understanding and Interactions.

    Directory of Open Access Journals (Sweden)

    Helena Näs

    2011-02-01

    Full Text Available According to previous research, students show difficulties in understanding photosynthesis and respiration, and basic ecological concepts like energy flow in ecosystems. There are successful teaching units accomplished in this area and many of them can be described as inquiry-based teaching. One definition of inquiry-based teaching is that it involves everything from finding problems, investigating them, debating with peers and trying to explain and give solutions. Accordingly students need to be confronted with challenging questions and empirical data to reason about and teachers need to implement student-generated inquiry discussion since students often stay silent and do not express their thoughts during science lessons. This thesis will focus on young peoples’ understanding of the functioning of plants, students’ participation during biology lessons, and how biology teaching is accomplished in primary and secondary school.Two school classroom projects focusing on teaching about plants and ecology are described. Four teachers and their 4th, 5th and 6th grade classes plus two science teachers and their three 8th grade classes collaborated. Photosynthesis and respiration were made concrete by using tasks where plants, plant cells, germs, seeds and the gas exchange were used. The aim was to listen to students’ reasoning in both teaching and interview situations. Learning outcome, as described by students’ reasoning in the classrooms and in individual interviews but also by their test results, is especially focused. Student-student and student-teacher interactions have been analysed with an ethnographic approach in the classroom context.The plant tasks encouraged the students’ in primary school to develop scientific reasoning and the interviews confirmed that the students had learned about photosynthesis. The ecology teaching in secondary school showed a substantial understanding confirmed both by students’ oral and written

  14. An examination of student attitudes and understanding of exponential functions using interactive instructional multimedia

    Science.gov (United States)

    Singleton, Cynthia M.

    The purpose of this study was to examine students' attitudes and understanding of exponential functions using InterAct Math, a mathematics tutorial software. The researcher used a convenience sampling of a total of 78 students from two intact pre-calculus classes; the students in the experimental group totaled 41 and the control group totaled 37. The two groups were exposed to the same curriculum content taught by the same instructor, the researcher. The experimental group used the mathematics tutorial software as an integral part of the instructional delivery. The control group used traditional instruction without integration of the educational technology. Data were collected during a two week span using a mixed-methodology to address the major research questions: (1) Is there a statistically significant difference in the mean achievement test scores between the experimental and the control groups? (2) Is there a statistically significant difference in students' attitudes toward learning mathematics between the experimental group and the control group? The researcher utilized paired t-tests and independent t-tests as statistical methods to evaluate the effectiveness of the intervention and to establish whether there was a significant difference between the experimental and control groups. Based on the analyses of the quantitative data, it was established that the students who received the InterAct Math tutorial (experimental group) did not perform better than the control group on exponential functions, graphs and applications. However, the quantitative part of the study (Aiken-Dreger Mathematics Attitude Scale) revealed that, while students in the experimental and control groups started with similar attitudes about mathematics and the integration of technology, their attitudes were significantly different at the conclusion of the study. The fear of mathematics was reduced for the experimental group at the end of the study, and their enjoyment of the subject matter

  15. Probing Genomic Aspects of the Multi-Host Pathogen Clostridium perfringens Reveals Significant Pangenome Diversity, and a Diverse Array of Virulence Factors

    Directory of Open Access Journals (Sweden)

    Raymond Kiu

    2017-12-01

    Full Text Available Clostridium perfringens is an important cause of animal and human infections, however information about the genetic makeup of this pathogenic bacterium is currently limited. In this study, we sought to understand and characterise the genomic variation, pangenomic diversity, and key virulence traits of 56 C. perfringens strains which included 51 public, and 5 newly sequenced and annotated genomes using Whole Genome Sequencing. Our investigation revealed that C. perfringens has an “open” pangenome comprising 11667 genes and 12.6% of core genes, identified as the most divergent single-species Gram-positive bacterial pangenome currently reported. Our computational analyses also defined C. perfringens phylogeny (16S rRNA gene in relation to some 25 Clostridium species, with C. baratii and C. sardiniense determined to be the closest relatives. Profiling virulence-associated factors confirmed presence of well-characterised C. perfringens-associated exotoxins genes including α-toxin (plc, enterotoxin (cpe, and Perfringolysin O (pfo or pfoA, although interestingly there did not appear to be a close correlation with encoded toxin type and disease phenotype. Furthermore, genomic analysis indicated significant horizontal gene transfer events as defined by presence of prophage genomes, and notably absence of CRISPR defence systems in >70% (40/56 of the strains. In relation to antimicrobial resistance mechanisms, tetracycline resistance genes (tet and anti-defensins genes (mprF were consistently detected in silico (tet: 75%; mprF: 100%. However, pre-antibiotic era strain genomes did not encode for tet, thus implying antimicrobial selective pressures in C. perfringens evolutionary history over the past 80 years. This study provides new genomic understanding of this genetically divergent multi-host bacterium, and further expands our knowledge on this medically and veterinary important pathogen.

  16. Probing Genomic Aspects of the Multi-Host Pathogen Clostridium perfringens Reveals Significant Pangenome Diversity, and a Diverse Array of Virulence Factors.

    Science.gov (United States)

    Kiu, Raymond; Caim, Shabhonam; Alexander, Sarah; Pachori, Purnima; Hall, Lindsay J

    2017-01-01

    Clostridium perfringens is an important cause of animal and human infections, however information about the genetic makeup of this pathogenic bacterium is currently limited. In this study, we sought to understand and characterise the genomic variation, pangenomic diversity, and key virulence traits of 56 C. perfringens strains which included 51 public, and 5 newly sequenced and annotated genomes using Whole Genome Sequencing. Our investigation revealed that C. perfringens has an "open" pangenome comprising 11667 genes and 12.6% of core genes, identified as the most divergent single-species Gram-positive bacterial pangenome currently reported. Our computational analyses also defined C. perfringens phylogeny (16S rRNA gene) in relation to some 25 Clostridium species, with C. baratii and C. sardiniense determined to be the closest relatives. Profiling virulence-associated factors confirmed presence of well-characterised C. perfringens -associated exotoxins genes including α-toxin ( plc ), enterotoxin ( cpe ), and Perfringolysin O ( pfo or pfoA ), although interestingly there did not appear to be a close correlation with encoded toxin type and disease phenotype. Furthermore, genomic analysis indicated significant horizontal gene transfer events as defined by presence of prophage genomes, and notably absence of CRISPR defence systems in >70% (40/56) of the strains. In relation to antimicrobial resistance mechanisms, tetracycline resistance genes ( tet ) and anti-defensins genes ( mprF ) were consistently detected in silico ( tet : 75%; mprF : 100%). However, pre-antibiotic era strain genomes did not encode for tet , thus implying antimicrobial selective pressures in C. perfringens evolutionary history over the past 80 years. This study provides new genomic understanding of this genetically divergent multi-host bacterium, and further expands our knowledge on this medically and veterinary important pathogen.

  17. Experimental simulation: using generative modelling and palaeoecological data to understand human-environment interactions

    Directory of Open Access Journals (Sweden)

    George Perry

    2016-10-01

    Full Text Available The amount of palaeoecological information available continues to grow rapidly, providing improved descriptions of the dynamics of past ecosystems and enabling them to be seen from new perspectives. At the same time, there has been concern over whether palaeoecological enquiry needs to move beyond descriptive inference to a more hypothesis-focussed or experimental approach; however, the extent to which conventional hypothesis-driven scientific frameworks can be applied to historical contexts (i.e., the past is the subject of ongoing debate. In other disciplines concerned with human-environment interactions, including physical geography and archaeology, there has been growing use of generative simulation models, typified by agent-based approaches. Generative modelling encourages counter-factual questioning (what if…?, a mode of argument that is particularly important in systems and time-periods, such as the Holocene and now the Anthropocene, where the effects of humans and other biophysical processes are deeply intertwined. However, palaeoecologically focused simulation of the dynamics of the ecosystems of the past either seems to be conducted to assess the applicability of some model to the future or treats humans simplistically as external forcing factors. In this review we consider how generative simulation-modelling approaches could contribute to our understanding of past human-environment interactions. We consider two key issues: the need for null models for understanding past dynamics and the need to be able learn more from pattern-based analysis. In this light, we argue that there is considerable scope for palaeocology to benefit from developments in generative models and their evaluation. We discuss the view that simulation is a form of experiment and, by using case studies, consider how the many patterns available to palaeoecologists can support model evaluation in a way that moves beyond simplistic pattern-matching and how such models

  18. Multilayered phantoms with tunable optical properties for a better understanding of light/tissue interactions

    Science.gov (United States)

    Roig, Blandine; Koenig, Anne; Perraut, François; Piot, Olivier; Vignoud, Séverine; Lavaud, Jonathan; Manfait, Michel; Dinten, Jean-Marc

    2015-03-01

    Light/tissue interactions, like diffuse reflectance, endogenous fluorescence and Raman scattering, are a powerful means for providing skin diagnosis. Instrument calibration is an important step. We thus developed multilayered phantoms for calibration of optical systems. These phantoms mimic the optical properties of biological tissues such as skin. Our final objective is to better understand light/tissue interactions especially in the case of confocal Raman spectroscopy. The phantom preparation procedure is described, including the employed method to obtain a stratified object. PDMS was chosen as the bulk material. TiO2 was used as light scattering agent. Dye and ink were adopted to mimic, respectively, oxy-hemoglobin and melanin absorption spectra. By varying the amount of the incorporated components, we created a material with tunable optical properties. Monolayer and multilayered phantoms were designed to allow several characterization methods. Among them, we can name: X-ray tomography for structural information; Diffuse Reflectance Spectroscopy (DRS) with a homemade fibered bundle system for optical characterization; and Raman depth profiling with a commercial confocal Raman microscope for structural information and for our final objective. For each technique, the obtained results are presented and correlated when possible. A few words are said on our final objective. Raman depth profiles of the multilayered phantoms are distorted by elastic scattering. The signal attenuation through each single layer is directly dependent on its own scattering property. Therefore, determining the optical properties, obtained here with DRS, is crucial to properly correct Raman depth profiles. Thus, it would be permitted to consider quantitative studies on skin for drug permeation follow-up or hydration assessment, for instance.

  19. How innovative ICT tools can enhance understanding of interactions between societal, hydrological and environmental changes

    Science.gov (United States)

    Foglia, L.; Borsi, I.; Cannata, M.; De Filippis, G.; Criollo, R.; Mehl, S.; Rossetto, R.

    2017-12-01

    The interaction of environmental, physical, and socioeconomic processes alter and are altered by water and by how human can affect water use. For example, a warming climate increases the chance of warm temperatures and lack of precipitation, and when combined with growing population requires understanding of impact on water resources and on all the processes related to the water budget including evapotranspiration. On this foundation, humans add engineered and social systems to control, manage, utilize, and alter our water environment for a variety of uses and through a variety of organizational and individual decisions. Some engineered systems have mixed consequences, for example groundwater helped sustain agriculture during drought periods, but then groundwater levels critically decrease with no chances to recover in some parts of the world. Innovative ICT tools have been demonstrated as a helpful tool for enhancing human understanding of the effect that societal, economical, and policy-based decisions have on the water resources and on the environment in general. Here we apply the new FREEWAT platform to demonstrate the importance of developing ad-hoc database and hydrological models to simulate different scenarios using a participatory approach. Stakeholders have been involved in data collection, database design and model development during the entire project period and discussion between researcher and stakeholders have been fostered during Focus Groups and workshops organized in many countries in Europe and beyond (including case studies in Ukraine and Africa). FREEWAT is an open source and public domain GIS integrated modelling environment for simulation of water quantity and quality in surface water and groundwater with an integrated water management and planning module. FREEWAT aims at promoting water resource management by simplifying the application of the Water Framework Directive and related Directives. Fourteen case studies have been considered and

  20. Using a social-ecological systems perspective to understand tourism and landscape interactions in coastal areas

    Directory of Open Access Journals (Sweden)

    Jasper Hessel Heslinga

    2017-04-01

    Full Text Available Purpose – The purpose of this paper is to look at the potential synergies between tourism and landscapes and examine the potential contribution of tourism to build social-ecological resilience in the Dutch Wadden. Design/methodology/approach – The authors reveal how a social-ecological systems perspective can be used to conceptualize the Wadden as a coupled and dynamic system. This paper is a conceptual analysis that applies this approach to the Dutch Wadden. The data used for the inquiry primarily comes from a literature review. Findings – The authors argue that the social-ecological systems perspective is a useful approach and could be used to improve the governance of multi-functional socio-ecological systems in coastal areas. Opportunities for synergies between tourism and landscapes have been overlooked. The authors consider that tourism and nature protection are potentially compatible and that the synergies should be identified. Research limitations/implications – This paper is only a conceptual application rather than an empirical case study. Further research to actually apply the methodology is needed. Practical implications – Managers of protected areas should consider applying a social-ecological systems approach. Social implications – The views of a wide variety of stakeholders should be considered in landscape planning. Originality/value – The value of this paper lies in the articulation of the social-ecological systems perspective as a way to identify and understand the complex interactions between tourism and landscape, and the potential synergies between them.

  1. Dynamics of gas-surface interactions atomic-level understanding of scattering processes at surfaces

    CERN Document Server

    Díez Muniño, Ricardo

    2013-01-01

    This book gives a representative survey of the state of the art of research on gas-surface interactions. It provides an overview of the current understanding of gas surface dynamics and, in particular, of the reactive and non-reactive processes of atoms and small molecules at surfaces. Leading scientists in the field, both from the theoretical and the experimental sides, write in this book about their most recent advances. Surface science grew as an interdisciplinary research area over the last decades, mostly because of new experimental technologies (ultra-high vacuum, for instance), as well as because of a novel paradigm, the ‘surface science’ approach. The book describes the second transformation which is now taking place pushed by the availability of powerful quantum-mechanical theoretical methods implemented numerically. In the book, experiment and theory progress hand in hand with an unprecedented degree of accuracy and control. The book presents how modern surface science targets the atomic-level u...

  2. How can the study of action kinematics inform our understanding of human social interaction?

    Science.gov (United States)

    Krishnan-Barman, Sujatha; Forbes, Paul A G; Hamilton, Antonia F de C

    2017-10-01

    The kinematics of human actions are influenced by the social context in which they are performed. Motion-capture technology has allowed researchers to build up a detailed and complex picture of how action kinematics vary across different social contexts. Here we review three task domains-point-to-point imitation tasks, motor interference tasks and reach-to-grasp tasks-to critically evaluate how these tasks can inform our understanding of social interactions. First, we consider how actions within these task domains are performed in a non-social context, before highlighting how a plethora of social cues can perturb the baseline kinematics. We show that there is considerable overlap in the findings from these different tasks domains but also highlight the inconsistencies in the literature and the possible reasons for this. Specifically, we draw attention to the pitfalls of dealing with rich, kinematic data. As a way to avoid these pitfalls, we call for greater standardisation and clarity in the reporting of kinematic measures and suggest the field would benefit from a move towards more naturalistic tasks. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Creating the brain and interacting with the brain: an integrated approach to understanding the brain

    Science.gov (United States)

    Morimoto, Jun; Kawato, Mitsuo

    2015-01-01

    In the past two decades, brain science and robotics have made gigantic advances in their own fields, and their interactions have generated several interdisciplinary research fields. First, in the ‘understanding the brain by creating the brain’ approach, computational neuroscience models have been applied to many robotics problems. Second, such brain-motivated fields as cognitive robotics and developmental robotics have emerged as interdisciplinary areas among robotics, neuroscience and cognitive science with special emphasis on humanoid robots. Third, in brain–machine interface research, a brain and a robot are mutually connected within a closed loop. In this paper, we review the theoretical backgrounds of these three interdisciplinary fields and their recent progress. Then, we introduce recent efforts to reintegrate these research fields into a coherent perspective and propose a new direction that integrates brain science and robotics where the decoding of information from the brain, robot control based on the decoded information and multimodal feedback to the brain from the robot are carried out in real time and in a closed loop. PMID:25589568

  4. Models for the brane-bulk interaction: Toward understanding braneworld cosmological perturbations

    Science.gov (United States)

    Binétruy, Pierre; Bucher, Martin; Carvalho, Carla

    2004-08-01

    Using some simple toy models, we explore the nature of the brane-bulk interaction for cosmological models with a large extra dimension. We are in particular interested in understanding the role of the bulk gravitons, which from the point of view of an observer on the brane will appear to generate dissipation and nonlocality, effects that cannot be incorporated into an effective (3+1)-dimensional Lagrangian field theoretic description. We explicitly work out the dynamics of several discrete systems consisting of a finite number of degrees of freedom on the boundary coupled to a (1+1)-dimensional field theory subject to a variety of wave equations. Systems both with and without time translation invariance are considered and moving boundaries are discussed as well. The models considered contain all the qualitative features of quantized linearized cosmological perturbations for a Randall-Sundrum universe having an arbitrary expansion history, with the sole exception of gravitational gauge invariance, which will be treated in a later paper.

  5. T Lymphocyte-Endothelial Interactions: Emerging Understanding of Trafficking and Antigen-Specific Immunity

    Directory of Open Access Journals (Sweden)

    Christopher Vincent Carman

    2015-11-01

    Full Text Available Antigen-specific immunity requires regulated trafficking of T cells in and out of diverse tissues in order to orchestrate lymphocyte development, immune surveillance, responses and memory. The endothelium serves as a unique barrier, as well as a sentinel, between the blood and the tissues and as such it plays an essential locally tuned role in regulating T cell migration and information exchange. While it is well established that chemoattractants and adhesion molecules are major determinants of T cell trafficking, emerging studies have now enumerated a large number of molecular players as well as a range of discrete cellular remodeling activities (e.g. transmigratory cups and invadosome-like protrusions, IPLs that participate in directed migration and pathfinding by T cells. In addition to providing trafficking cues, intimate cell-cell interaction between lymphocytes and endothelial cells provide instruction to T cells that influence their activation and differentiation states. Perhaps the most intriguing and underappreciated of these ‘sentinel’ roles is the ability of the endothelium to act as a non-hematopoietic ‘semi-professional’ antigen-presenting cell. Close contacts between circulating T cells and antigen-presenting endothelium may play unique non-redundant roles in shaping adaptive immune responses within the periphery. A better understanding of the mechanisms directing T cell trafficking and the antigen-presenting role of the endothelium may not only increase our knowledge of the adaptive immune response but also empower the utility of emerging immunomodulatory therapeutics.

  6. Long-term experiments to better understand soil-human interactions

    Science.gov (United States)

    Bormann, B. T.; Homann, P. S.

    2011-12-01

    Interactions between soils and people may be transforming global conditions, but the interactions are poorly understood. Changes in soils have proven difficult to quantify, especially in complex ecosystems manifesting large spatiotemporal variability. Long-term ecosystem experiments that evaluate soil change and demonstrate alternative choices are important to understanding changes, discovering new controls and drivers, and influencing decisions. Inspired by agriculture studies, like Rothamsted, the US Forest Service established in 1990 a network of operational-scale experiments across the Pacific Northwest to evaluate long-term effects of different forest management and disturbance regimes. With a strong experimental design, these experiments are now helping to better understand the long-term effects of managing tree harvesting (clearcutting and thinning), woody debris, and tree and understory species composition, and-serendipitously-the effects of fire. Initial results from the Southern Oregon experimental site indicate surprisingly rapid soil changes in some regimes but not others. We've also learned that rapid change presents challenges to repeat sampling. We present our sample-archive and comparable-layer approaches that seek to accommodate changes in surface elevation, aggregation and disaggregation, and mineral-soil exports. Thinning mature forest stands (80-100 yrs old) did not significantly change soil C in 11-yrs. A small upper-layer C increase was observed after thinning, but it was similar to the control. Significant increases in upper-layer soil N were observed with most treatments, but all increases were similar to the control. Leaving woody debris had little effect. The most remarkable change occurred when mature stands were clearcut and Douglas-firs were planted and tended. Associated with rapid growth of Douglas-fir, an average of 8 Mg C ha-1 was lost from weathered soil 4-18 cm deep. This contrasts with clearcuts where early-seral hardwoods and

  7. Probability weighted ensemble transfer learning for predicting interactions between HIV-1 and human proteins.

    Directory of Open Access Journals (Sweden)

    Suyu Mei

    Full Text Available Reconstruction of host-pathogen protein interaction networks is of great significance to reveal the underlying microbic pathogenesis. However, the current experimentally-derived networks are generally small and should be augmented by computational methods for less-biased biological inference. From the point of view of computational modelling, data scarcity, data unavailability and negative data sampling are the three major problems for host-pathogen protein interaction networks reconstruction. In this work, we are motivated to address the three concerns and propose a probability weighted ensemble transfer learning model for HIV-human protein interaction prediction (PWEN-TLM, where support vector machine (SVM is adopted as the individual classifier of the ensemble model. In the model, data scarcity and data unavailability are tackled by homolog knowledge transfer. The importance of homolog knowledge is measured by the ROC-AUC metric of the individual classifiers, whose outputs are probability weighted to yield the final decision. In addition, we further validate the assumption that only the homolog knowledge is sufficient to train a satisfactory model for host-pathogen protein interaction prediction. Thus the model is more robust against data unavailability with less demanding data constraint. As regards with negative data construction, experiments show that exclusiveness of subcellular co-localized proteins is unbiased and more reliable than random sampling. Last, we conduct analysis of overlapped predictions between our model and the existing models, and apply the model to novel host-pathogen PPIs recognition for further biological research.

  8. Predicting and understanding comprehensive drug-drug interactions via semi-nonnegative matrix factorization.

    Science.gov (United States)

    Yu, Hui; Mao, Kui-Tao; Shi, Jian-Yu; Huang, Hua; Chen, Zhi; Dong, Kai; Yiu, Siu-Ming

    2018-04-11

    Drug-drug interactions (DDIs) always cause unexpected and even adverse drug reactions. It is important to identify DDIs before drugs are used in the market. However, preclinical identification of DDIs requires much money and time. Computational approaches have exhibited their abilities to predict potential DDIs on a large scale by utilizing pre-market drug properties (e.g. chemical structure). Nevertheless, none of them can predict two comprehensive types of DDIs, including enhancive and degressive DDIs, which increases and decreases the behaviors of the interacting drugs respectively. There is a lack of systematic analysis on the structural relationship among known DDIs. Revealing such a relationship is very important, because it is able to help understand how DDIs occur. Both the prediction of comprehensive DDIs and the discovery of structural relationship among them play an important guidance when making a co-prescription. In this work, treating a set of comprehensive DDIs as a signed network, we design a novel model (DDINMF) for the prediction of enhancive and degressive DDIs based on semi-nonnegative matrix factorization. Inspiringly, DDINMF achieves the conventional DDI prediction (AUROC = 0.872 and AUPR = 0.605) and the comprehensive DDI prediction (AUROC = 0.796 and AUPR = 0.579). Compared with two state-of-the-art approaches, DDINMF shows it superiority. Finally, representing DDIs as a binary network and a signed network respectively, an analysis based on NMF reveals crucial knowledge hidden among DDIs. Our approach is able to predict not only conventional binary DDIs but also comprehensive DDIs. More importantly, it reveals several key points about the DDI network: (1) both binary and signed networks show fairly clear clusters, in which both drug degree and the difference between positive degree and negative degree show significant distribution; (2) the drugs having large degrees tend to have a larger difference between positive degree

  9. They Work Together to Roar: Kindergartners' Understanding of an Interactive Causal Task

    Science.gov (United States)

    Solis, S. Lynneth; Grotzer, Tina A.

    2016-01-01

    The aim of this study was to investigate kindergartners' exploration of interactive causality during their play with a pair of toy sound blocks. Interactive causality refers to a type of causal pattern in which two entities interact to produce a causal force, as in particle attraction and symbiotic relationships. Despite being prevalent in nature,…

  10. Meeting report - Intercellular interactions in context: towards a mechanistic understanding of cells in organs.

    Science.gov (United States)

    Bryant, David; Johnson, Aaron

    2017-07-01

    The Company of Biologists held the workshop 'Intercellular interactions in context: towards a mechanistic understanding of cells in organs' at historic Wiston House in West Sussex, UK, 5-8 February 2017. The meeting brought together around 30 scientists from disparate backgrounds - yet with a common interest of how tissue morphogenesis occurs and its dysregulation leads to pathologies - to intensively discuss their latest research, the current state of the field, as well as any challenges for the future. This report summarises the concepts and challenges that arose as key questions for the fields of cell, cancer and developmental biology. By design of the organizers - Andrew Ewald (John Hopkins University, MA), John Wallingford (University of Texas at Austin, TX) and Peter Friedl (Radboud University, Nijmegen, The Netherlands) - the attendee makeup was cross-sectional: both in terms of career stage and scientific background. This intermingling was mirrored in the workshop format; all participants - irrespective of career stage - were given equal speaking and question time, and all early-career researchers also chaired a session, which promoted an atmosphere for discussions that were open, egalitarian and supportive. This was particularly evident in the scheduled 'out-of-the-box' sessions, which provided an avenue for participants to raise ideas and concepts or to discuss specific problems they wanted feedback or clarification on. In the following, rather than act as court reporters and convey chronological accounting of presentations, we present the questions that arose from the workshop and should be posed to the field at large, by discussing the presentations as they relate to these concepts. © 2017. Published by The Company of Biologists Ltd.

  11. Towards an Enhanced Understanding of Plant–Microbiome Interactions to Improve Phytoremediation: Engineering the Metaorganism

    Science.gov (United States)

    Thijs, Sofie; Sillen, Wouter; Rineau, Francois; Weyens, Nele; Vangronsveld, Jaco

    2016-01-01

    Phytoremediation is a promising technology to clean-up contaminated soils based on the synergistic actions of plants and microorganisms. However, to become a widely accepted, and predictable remediation alternative, a deeper understanding of the plant–microbe interactions is needed. A number of studies link the success of phytoremediation to the plant-associated microbiome functioning, though whether the microbiome can exist in alternative, functional states for soil remediation, is incompletely understood. Moreover, current approaches that target the plant host, and environment separately to improve phytoremediation, potentially overlook microbial functions and properties that are part of the multiscale complexity of the plant-environment wherein biodegradation takes place. In contrast, in situ studies of phytoremediation research at the metaorganism level (host and microbiome together) are lacking. Here, we discuss a competition-driven model, based on recent evidence from the metagenomics level, and hypotheses generated by microbial community ecology, to explain the establishment of a catabolic rhizosphere microbiome in a contaminated soil. There is evidence to ground that if the host provides the right level and mix of resources (exudates) over which the microbes can compete, then a competitive catabolic and plant-growth promoting (PGP) microbiome can be selected for as long as it provides a competitive superiority in the niche. The competition-driven model indicates four strategies to interfere with the microbiome. Specifically, the rhizosphere microbiome community can be shifted using treatments that alter the host, resources, environment, and that take advantage of prioritization in inoculation. Our model and suggestions, considering the metaorganism in its natural context, would allow to gain further knowledge on the plant–microbial functions, and facilitate translation to more effective, and predictable phytotechnologies. PMID:27014254

  12. Towards an Enhanced Understanding of Plant-Microbiome Interactions to Improve Phytoremediation: Engineering the Metaorganism

    Directory of Open Access Journals (Sweden)

    Sofie eThijs

    2016-03-01

    Full Text Available Phytoremediation is a promising technology to clean-up contaminated soils based on the synergistic actions of plants and microorganisms. However, to become a widely accepted, and predictable remediation alternative, a deeper understanding of the plant-microbe interactions is needed. A number of studies link the success of phytoremediation to the plant-associated microbiome functioning, though whether the microbiome can exist in alternative, functional states for soil remediation, is incompletely understood. Moreover, current approaches that target the plant host, and environment separately to improve phytoremediation, potentially overlook microbial functions and properties that are part of the multiscale complexity of the plant-environment wherein biodegradation takes place. In contrast, in situ studies of phytoremediation research at the metaorganism level (host and microbiome together are lacking. Here, we discuss a competition-driven model, based on recent evidence from the metagenomics level, and hypotheses generated by microbial community ecology, to explain the establishment of a catabolic rhizosphere microbiome in a contaminated soil. There is evidence to ground that if the host provides the right level and mix of resources (exudates over which the microbes can compete, then a competitive catabolic and plant-growth promoting (PGP microbiome can be selected for as long as it provides a competitive superiority in the niche. The competition-driven model indicates four strategies to interfere with the microbiome. Specifically, the rhizosphere microbiome community can be shifted using treatments that alter the host, resources, environment, and that take advantage of prioritization in inoculation. Our model and suggestions, considering the metaorganism in its natural context, would allow to gain further knowledge on the plant-microbial functions, and facilitate translation to more effective, and predictable phytotechnologies.

  13. Understanding human - bat interactions in NSW, Australia: improving risk communication for prevention of Australian bat lyssavirus.

    Science.gov (United States)

    Quinn, Emma K; Massey, Peter D; Cox-Witton, Keren; Paterson, Beverley J; Eastwood, Keith; Durrheim, David N

    2014-07-02

    Australian bat lyssavirus (ABLV) infects a number of flying fox and insectivorous bats species in Australia. Human infection with ABLV is inevitably fatal unless prior vaccination and/or post-exposure treatment (PET) is given. Despite ongoing public health messaging about the risks associated with bat contact, surveillance data have revealed a four-fold increase in the number of people receiving PET for bat exposure in NSW between 2007 and 2011. Our study aimed to better understand these human - bat interactions in order to identify additional risk communication messages that could lower the risk of potential ABLV exposure. All people aged 18 years or over whom received PET for non-occupation related potential ABLV exposure in the Hunter New England Local Health District of Australia between July 2011 and July 2013 were considered eligible for the study. Eligible participants were invited to a telephone interview to explore the circumstances of their bat contact. Interviews were then transcribed and thematically analysed by two independent investigators. Of 21 eligible participants that were able to be contacted, 16 consented and participated in a telephone interview. Participants reported bats as being widespread in their environment but reported a general lack of awareness about ABLV, particularly the risk of disease from bat scratches. Participants who attempted to 'rescue' bats did so because of a deep concern for the bat's welfare. Participants reported a change in risk perception after the exposure event and provided suggestions for public health messages that could be used to raise awareness about ABLV. Reframing the current risk messages to account for the genuine concern of people for bat welfare may enhance the communication. The potential risk to the person and possible harm to the bat from an attempted 'rescue' should be promoted, along with contact details for animal rescue groups. The potential risk of ABLV from bat scratches merits greater emphasis.

  14. Children's aesthetic understanding of photographic art and the quality of art-related parent-child interactions.

    Science.gov (United States)

    Szechter, Lisa E; Liben, Lynn S

    2007-01-01

    This research was designed to examine the quality of children's aesthetic understanding of photographs, observe social interactions between parents and children in this aesthetic domain, and study whether qualitatively different dyadic interactions were associated with children's own aesthetic understanding. Parents and children (7-13 years; 40 dyads) individually completed measures of aesthetic understanding and jointly selected photographs for a souvenir scrapbook. Parents' artistic experience varied widely and was associated with their own performance on aesthetic understanding measures. Children's performance on the individual aesthetic tasks was related to age, but not to parents' art experience nor to the qualities of parent-child discussions of aesthetic concepts. Among both parents and children, artistic experience was associated with aesthetic preferences for photographs.

  15. The human-bacterial pathogen protein interaction networks of Bacillus anthracis, Francisella tularensis, and Yersinia pestis.

    Directory of Open Access Journals (Sweden)

    Matthew D Dyer

    2010-08-01

    Full Text Available Bacillus anthracis, Francisella tularensis, and Yersinia pestis are bacterial pathogens that can cause anthrax, lethal acute pneumonic disease, and bubonic plague, respectively, and are listed as NIAID Category A priority pathogens for possible use as biological weapons. However, the interactions between human proteins and proteins in these bacteria remain poorly characterized leading to an incomplete understanding of their pathogenesis and mechanisms of immune evasion.In this study, we used a high-throughput yeast two-hybrid assay to identify physical interactions between human proteins and proteins from each of these three pathogens. From more than 250,000 screens performed, we identified 3,073 human-B. anthracis, 1,383 human-F. tularensis, and 4,059 human-Y. pestis protein-protein interactions including interactions involving 304 B. anthracis, 52 F. tularensis, and 330 Y. pestis proteins that are uncharacterized. Computational analysis revealed that pathogen proteins preferentially interact with human proteins that are hubs and bottlenecks in the human PPI network. In addition, we computed modules of human-pathogen PPIs that are conserved amongst the three networks. Functionally, such conserved modules reveal commonalities between how the different pathogens interact with crucial host pathways involved in inflammation and immunity.These data constitute the first extensive protein interaction networks constructed for bacterial pathogens and their human hosts. This study provides novel insights into host-pathogen interactions.

  16. From Trust in Automation to Decision Neuroscience: Applying Cognitive Neuroscience Methods to Understand and Improve Interaction Decisions Involved in Human Automation Interaction

    Science.gov (United States)

    Drnec, Kim; Marathe, Amar R.; Lukos, Jamie R.; Metcalfe, Jason S.

    2016-01-01

    Human automation interaction (HAI) systems have thus far failed to live up to expectations mainly because human users do not always interact with the automation appropriately. Trust in automation (TiA) has been considered a central influence on the way a human user interacts with an automation; if TiA is too high there will be overuse, if TiA is too low there will be disuse. However, even though extensive research into TiA has identified specific HAI behaviors, or trust outcomes, a unique mapping between trust states and trust outcomes has yet to be clearly identified. Interaction behaviors have been intensely studied in the domain of HAI and TiA and this has led to a reframing of the issues of problems with HAI in terms of reliance and compliance. We find the behaviorally defined terms reliance and compliance to be useful in their functionality for application in real-world situations. However, we note that once an inappropriate interaction behavior has occurred it is too late to mitigate it. We therefore take a step back and look at the interaction decision that precedes the behavior. We note that the decision neuroscience community has revealed that decisions are fairly stereotyped processes accompanied by measurable psychophysiological correlates. Two literatures were therefore reviewed. TiA literature was extensively reviewed in order to understand the relationship between TiA and trust outcomes, as well as to identify gaps in current knowledge. We note that an interaction decision precedes an interaction behavior and believe that we can leverage knowledge of the psychophysiological correlates of decisions to improve joint system performance. As we believe that understanding the interaction decision will be critical to the eventual mitigation of inappropriate interaction behavior, we reviewed the decision making literature and provide a synopsis of the state of the art understanding of the decision process from a decision neuroscience perspective. We forward

  17. From Trust in Automation to Decision Neuroscience: Applying Cognitive Neuroscience Methods to Understand and Improve Interaction Decisions Involved in Human Automation Interaction.

    Science.gov (United States)

    Drnec, Kim; Marathe, Amar R; Lukos, Jamie R; Metcalfe, Jason S

    2016-01-01

    Human automation interaction (HAI) systems have thus far failed to live up to expectations mainly because human users do not always interact with the automation appropriately. Trust in automation (TiA) has been considered a central influence on the way a human user interacts with an automation; if TiA is too high there will be overuse, if TiA is too low there will be disuse. However, even though extensive research into TiA has identified specific HAI behaviors, or trust outcomes, a unique mapping between trust states and trust outcomes has yet to be clearly identified. Interaction behaviors have been intensely studied in the domain of HAI and TiA and this has led to a reframing of the issues of problems with HAI in terms of reliance and compliance. We find the behaviorally defined terms reliance and compliance to be useful in their functionality for application in real-world situations. However, we note that once an inappropriate interaction behavior has occurred it is too late to mitigate it. We therefore take a step back and look at the interaction decision that precedes the behavior. We note that the decision neuroscience community has revealed that decisions are fairly stereotyped processes accompanied by measurable psychophysiological correlates. Two literatures were therefore reviewed. TiA literature was extensively reviewed in order to understand the relationship between TiA and trust outcomes, as well as to identify gaps in current knowledge. We note that an interaction decision precedes an interaction behavior and believe that we can leverage knowledge of the psychophysiological correlates of decisions to improve joint system performance. As we believe that understanding the interaction decision will be critical to the eventual mitigation of inappropriate interaction behavior, we reviewed the decision making literature and provide a synopsis of the state of the art understanding of the decision process from a decision neuroscience perspective. We forward

  18. Geo-Sandbox: An Interactive Geoscience Training Tool with Analytics to Better Understand Student Problem Solving Approaches

    Science.gov (United States)

    Butt, N.; Pidlisecky, A.; Ganshorn, H.; Cockett, R.

    2015-12-01

    The software company 3 Point Science has developed three interactive learning programs designed to teach, test and practice visualization skills and geoscience concepts. A study was conducted with 21 geoscience students at the University of Calgary who participated in 2 hour sessions of software interaction and written pre and post-tests. Computer and SMART touch table interfaces were used to analyze user interaction, problem solving methods and visualization skills. By understanding and pinpointing user problem solving methods it is possible to reconstruct viewpoints and thought processes. This could allow us to give personalized feedback in real time, informing the user of problem solving tips and possible misconceptions.

  19. Coevolution study of mitochondria respiratory chain proteins: toward the understanding of protein--protein interaction.

    Science.gov (United States)

    Yang, Ming; Ge, Yan; Wu, Jiayan; Xiao, Jingfa; Yu, Jun

    2011-05-20

    Coevolution can be seen as the interdependency between evolutionary histories. In the context of protein evolution, functional correlation proteins are ever-present coordinated evolutionary characters without disruption of organismal integrity. As to complex system, there are two forms of protein--protein interactions in vivo, which refer to inter-complex interaction and intra-complex interaction. In this paper, we studied the difference of coevolution characters between inter-complex interaction and intra-complex interaction using "Mirror tree" method on the respiratory chain (RC) proteins. We divided the correlation coefficients of every pairwise RC proteins into two groups corresponding to the binary protein--protein interaction in intra-complex and the binary protein--protein interaction in inter-complex, respectively. A dramatical discrepancy is detected between the coevolution characters of the two sets of protein interactions (Wilcoxon test, p-value = 4.4 × 10(-6)). Our finding reveals some critical information on coevolutionary study and assists the mechanical investigation of protein--protein interaction. Furthermore, the results also provide some unique clue for supramolecular organization of protein complexes in the mitochondrial inner membrane. More detailed binding sites map and genome information of nuclear encoded RC proteins will be extraordinary valuable for the further mitochondria dynamics study. Copyright © 2011. Published by Elsevier Ltd.

  20. Understanding plant-to-plant interactions for soil resources in multilayered Iberian dehesas

    Science.gov (United States)

    Moreno, G.; Rolo, V.; Cubera, E.; López-Díaz, L.

    2009-04-01

    Iberian dehesa is usually defined as two-layered silvopastoral system, where native grasses cohabit with a scattered widely-space tree layer. In the last two decades, an intense debate has been developed on the sustainability of this simplified type of dehesa. While some authors argue that that the forest cycle has been disrupted in most dehesas, where the lack of regeneration is an inherent problem to their exploitation, other authors have showed that dehesa degradation is easily reversible if certain abandonment is periodically exerted. The coexistence of two-layered plots with multilayered plots (encroached open woodlands) and mono-layered plots (either closed forest or mono-pasture/monocrops) has been a common feature of dehesas, as result of a systematic combination of agricultural, pastoral, and forestry uses. Different structures of vegetation depend on land use, giving a mosaic at both estate and landscape scales. These mosaic-type systems allow finding several scenarios of plant-to-plant interactions, mostly at belowground level. A key issue for sustainable management of oak woodland is to understand the complexity of the plant-to-plant relationships and their consequences in the ecosystem functioning in terms of productivity and stability. The competitive abilities of component systems are modified by the environment conditions. Dehesas, as most savanna systems, exhibit a low rainfall with high variability within and between years as well as a high evaporative demand during the summer. Indeed, water availability is one of the major ecological factors influencing either natural savannas or man-made open woodlands. Although most of the available studies have focused different aspects of the mature tree-grass interactions, we also present here some recent results on tree-tree, tree-shrub, shrub-seedling and seedling-grass interactions, explained mostly in terms of competition for soil water and nutrients. Trees can modify the soil and microclimate

  1. Students' Understanding on Newton's Third Law in Identifying the Reaction Force in Gravity Interactions

    Science.gov (United States)

    Zhou, Shaona; Zhang, Chunbin; Xiao, Hua

    2015-01-01

    In the past three decades, previous researches showed that students had various misconceptions of Newton's Third Law. The present study focused on students' difficulties in identifying the third-law force pair in gravity interaction situations. An instrument involving contexts with gravity and non-gravity associated interactions was designed and…

  2. Extending Face-to-Face Interactions: Understanding and Developing an Online Teacher and Family Community

    Science.gov (United States)

    Zhang, Chun; Du, Jianxia; Sun, Li; Ding, Yi

    2018-01-01

    Technology has been quickly changing human interactions, traditional practices, and almost every aspect of our lives. It is important to maintain effective face-to-face communication and interactions between teachers and families. Nonetheless, technology and its tools can also extend and enhance family-teacher relationships and partnerships. This…

  3. Parent-Adolescent Collaboration: An Interpersonal Model for Understanding Optimal Interactions

    Science.gov (United States)

    Beveridge, Ryan M.; Berg, Cynthia A.

    2007-01-01

    Current parent-adolescent behavioral interaction research highlights the importance of three elements of behavior in defining adaptive interactions: autonomy, control, and warmth vs. hostility. However, this research has largely addressed the developmental needs and psychosocial outcomes of adolescents, as opposed to parents, with a focus on how…

  4. User-generated content? Get Serious! Understanding the interactions between organizations and customers on social media

    NARCIS (Netherlands)

    Moser, C.; van Eijkeren, A

    2016-01-01

    This study examines interactions between customers and organisations on social media by investigating how user-generated content influences interactions between organisations and customers on social media. In compliance with existing perspectives on user-generated content, a total of seven

  5. Understanding the Symbolic Capital of Intercultural Interactions: A Case Study of International Students in Australia

    Science.gov (United States)

    Pham, Lien; Tran, Ly

    2015-01-01

    Intercultural interaction plays an important role in contributing to international students' learning and wellbeing in the host country. While research on international students' intercultural interactions reveals multifaceted aspects of personal and social factors, there is a tendency to consider language barrier and cultural differences as…

  6. Understanding the influence of social interactions on individual's behavior pattern in a work environment

    NARCIS (Netherlands)

    Chen, Chih-Wei; Aztiria, Asier; Ben Allouch, Soumaya; Aghajan, Hamid; Salah, Albert Ali; Lepri, Bruno

    2011-01-01

    In this work, we study social interactions in a work environment and investigate how the presence of other people changes personal behavior patterns. We design the visual processing algorithms to track multiple people in the environment and detect dyadic interactions using a discriminative

  7. The Effect of Interactive Lecture Demonstrations on Students' Understanding of Heat and Temperature: A Study from Thailand

    Science.gov (United States)

    Tanahoung, Choksin; Chitaree, Ratchapak; Soankwan, Chernchok; Sharma, Manjula D.; Johnston, Ian D.

    2009-01-01

    The purpose of this study was to investigate the effectiveness of Interactive Lecture Demonstrations over traditional instruction on university students' understanding of heat and temperature. The participants were 327 first year undergraduate students from two science classes in two academic years from the same university in Thailand. One class…

  8. Towards a molecular level understanding of the sulfanilamide-soil organic matter-interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Ashour A., E-mail: ashour.ahmed@uni-rostock.de [University of Rostock, Institute of Physics, Albert-Einstein-Str. 23-24, D-18059 Rostock (Germany); Steinbeis GmbH & Co. KG für Technologietransfer, 70174 Stuttgart (Germany); University of Cairo, Faculty of Science, Department of Chemistry, 12613 Giza (Egypt); Thiele-Bruhn, Sören, E-mail: thiele@uni-trier.de [University of Trier, Soil Science, D-54286 Trier (Germany); Leinweber, Peter, E-mail: peter.leinweber@uni-rostock.de [Steinbeis GmbH & Co. KG für Technologietransfer, 70174 Stuttgart (Germany); University of Rostock, Soil Science, D-18051 Rostock (Germany); Kühn, Oliver, E-mail: oliver.kuehn@uni-rostock.de [University of Rostock, Institute of Physics, Albert-Einstein-Str. 23-24, D-18059 Rostock (Germany)

    2016-07-15

    Sorption experiments of sulfanilamide (SAA) on well-characterized samples of soil size-fractions were combined with the modeling of SAA-soil-interaction via quantum chemical calculations. Freundlich unit capacities were determined in batch experiments and it was found that they increase with the soil organic matter (SOM) content according to the order fine silt > medium silt > clay > whole soil > coarse silt > sand. The calculated binding energies for mass-spectrometrically quantified sorption sites followed the order ionic species > peptides > carbohydrates > phenols and lignin monomers > lignin dimers > heterocyclic compounds > fatty acids > sterols > aromatic compounds > lipids, alkanes, and alkenes. SAA forms H-bonds through its polar centers with the polar SOM sorption sites. In contrast dispersion and π-π-interactions predominate the interaction of the SAA aromatic ring with the non-polar moieties of SOM. Moreover, the dipole moment, partial atomic charges, and molecular volume of the SOM sorption sites are the main physical properties controlling the SAA-SOM-interaction. Further, reasonable estimates of the Freundlich unit capacities from the calculated binding energies have been established. Consequently, we suggest using this approach in forthcoming studies to disclose the interactions of a wide range of organic pollutants with SOM. - Highlights: • Experiment and theory showed that SAA obeys a site-specific sorption on soil surfaces. • SAA-SOM-interaction increases by increasing polarity of SOM sorption site. • H-bonds, dispersion, and π-π-interactions were observed for SAA-SOM-interaction. • Dipole moment and atomic charges of SOM sorption sites control SAA-SOM-interaction. • The Freundlich unit capacities were estimated from the calculated binding energies. • The current SOM model is flexible to describe interactions of SOM with other pollutants.

  9. The molecular understanding of interfacial interactions of functionalized graphene and chitosan

    International Nuclear Information System (INIS)

    Zhang, Hong-ping; Luo, Xue-gang; Lin, Xiao-yan; Lu, Xiong; Tang, Youhong

    2016-01-01

    Graphical abstract: The type of the functional groups can be used to modulating interactions between graphene sheet and chitosan. - Highlights: • Investigate interfacial interactions between chitosan and functionalized graphene by DFT. • Observe covalent linkages between COOH-modified graphene and chitosan units. • Multi-functionalized graphene regulates the interfacial interactions with chitosan. • It is useful for guiding the preparation of graphene/chitosan composites. - Abstract: Graphene-reinforced chitosan scaffolds have been extensively studied for several years as promising hard tissue replacements. However, the interfacial interactions between graphene and chitosan are strongly related to the solubility, processability, and mechanical properties of graphene-reinforced chitosan (G–C) composites. The functionalization of graphene is regarded as the most effective way to improve the abovementioned properties of the G–C composite. In this study, the interfacial interactions between chitosan and functionalized graphene sheets with carboxylization (COOH-), amination (NH 2 -), and hydroxylation (OH-) groups were systematically studied at the electronic level using the method of ab initio simulations based on quantum mechanics theory and the observations were compared with reported experimental results. The covalent linkages between COOH-modified graphene and the chitosan units were demonstrated and the combination of multi-functionalization on graphene could regulate the interfacial interactions between graphene and the chitosan. The interfacial interactions between chitosan and properly functionalized graphene are critical for the preparation of G–C-based composites for tissue engineering scaffolds and other applications.

  10. Towards a better understanding of the specificity of protein-protein interaction

    Czech Academy of Sciences Publication Activity Database

    Kysilka, Jiří; Vondrášek, Jiří

    2012-01-01

    Roč. 25, č. 11 (2012), s. 604-615 ISSN 0952-3499 R&D Projects: GA ČR GAP208/10/0725; GA ČR GAP302/10/0427; GA MŠk(CZ) LH11020 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50520701 Keywords : protein-protein interaction * molecular recognition * x-ray structure analysis * empirical potentials * side chain-side chain interaction * interaction energy * bioinformatics Subject RIV: CE - Biochemistry Impact factor: 3.006, year: 2012

  11. Co-evolutionary interactions between host resistance and pathogen avirulence genes in rice-Magnaporthe oryzae pathosystem.

    Science.gov (United States)

    Singh, Pankaj Kumar; Ray, Soham; Thakur, Shallu; Rathour, Rajeev; Sharma, Vinay; Sharma, Tilak Raj

    2018-06-01

    Rice and Magnaporthe oryzae constitutes an ideal pathosystem for studying host-pathogen interaction in cereals crops. There are two alternative hypotheses, viz. Arms race and Trench warfare, which explain the co-evolutionary dynamics of hosts and pathogens which are under continuous confrontation. Arms race proposes that both R- and Avr- genes of host and pathogen, respectively, undergo positive selection. Alternatively, trench warfare suggests that either R- or Avr- gene in the pathosystem is under balanced selection intending to stabilize the genetic advantage gained over the opposition. Here, we made an attempt to test the above-stated hypotheses in rice-M. oryzae pathosystem at loci of three R-Avr gene pairs, Piz-t-AvrPiz-t, Pi54-AvrPi54 and Pita-AvrPita using allele mining approach. Allele mining is an efficient way to capture allelic variants existing in the population and to study the selective forces imposed on the variants during evolution. Results of nucleotide diversity, neutrality statistics and phylogenetic analyses reveal that Piz-t, Pi54 and AvrPita are diversified and under positive selection at their corresponding loci, while their counterparts, AvrPiz-t, AvrPi54 and Pita are conserved and under balancing selection, in nature. These results imply that rice-M. oryzae populations are engaged in a trench warfare at least at the three R/Avr loci studied. It is a maiden attempt to study the co-evolution of three R-Avr gene pairs in this pathosystem. Knowledge gained from this study will help in understanding the evolutionary dynamics of host-pathogen interaction in a better way and will also aid in developing new durable blast resistant rice varieties in future. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Ontology-based representation and analysis of host-Brucella interactions.

    Science.gov (United States)

    Lin, Yu; Xiang, Zuoshuang; He, Yongqun

    2015-01-01

    -Brucella interactions and implemented in IDOBRU. Current IDOBRU includes 3611 ontology terms. SPARQL queries identified many results that are critical to the host-Brucella interactions. For example, out of 269 protein virulence factors related to macrophage-Brucella interactions, 81 are critical to Brucella intracellular replication inside macrophages. A SPARQL query also identified 11 biological processes important for Brucella virulence. To systematically represent and analyze fundamental host-pathogen interaction mechanisms, we provided for the first time comprehensive ontological modeling of host-pathogen interactions using Brucella as the pathogen model. The methods and ontology representations used in our study are generic and can be broadened to study the interactions between hosts and other pathogens.

  13. Multiple stressor effects in Chlamydomonas reinhardtii--toward understanding mechanisms of interaction between effects of ultraviolet radiation and chemical pollutants.

    Science.gov (United States)

    Korkaric, Muris; Behra, Renata; Fischer, Beat B; Junghans, Marion; Eggen, Rik I L

    2015-05-01

    The effects of chemical pollutants and environmental stressors, such as ultraviolet radiation (UVR), can interact when organisms are simultaneously exposed, resulting in higher (synergistic) or lower (antagonistic) multiple stressor effects than expected based on the effects of single stressors. Current understanding of interactive effects is limited due to a lack of mechanism-based multiple stressor studies. It has been hypothesized that effect interactions may generally occur if chemical and non-chemical stressors cause similar physiological effects in the organism. To test this hypothesis, we exposed the model green alga Chlamydomonas reinhardtii to combinations of UVR and single chemicals displaying modes of action (MOA) similar or dissimilar to the impact of UVR on photosynthesis. Stressor interactions were analyzed based on the independent action model. Effect interactions were found to depend on the MOA of the chemicals, and also on their concentrations, the exposure time and the measured endpoint. Indeed, only chemicals assumed to cause effects on photosynthesis similar to UVR showed interactions with UVR on photosynthetic yield: synergistic in case of Cd(II) and paraquat and antagonistic in case of diuron. No interaction on photosynthesis was observed for S-metolachlor, which acts dissimilarly to UVR. However, combined effects of S-metolachlor and UVR on algal reproduction were synergistic, highlighting the importance of considering additional MOA of UVR. Possible mechanisms of stressor effect interactions are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Soil-structure interaction studies for understanding the behavior of integral abutment bridges.

    Science.gov (United States)

    2012-03-01

    Integral Abutment Bridges (IAB) are bridges without any joints within the bridge deck or between the : superstructure and the abutments. An IAB provides many advantages during construction and maintenance of : a bridge. Soil-structure interactions at...

  15. Understanding interparticle interactions in dry powder inhalation : glass beads as an innovative model carrier system

    OpenAIRE

    Renner, Niklas Ludwig

    2017-01-01

    Delivery of drugs via the pulmonary route is the most common approach to treat diseases of the respiratory system, e.g. asthma bronchiale. Here, the active pharmaceutical ingredient is generally formulated in a so-called interactive mixture with a coarse and inert carrier. This enhances flowability and therefore dose metering and dispersibility. Interparticle interactions between carrier and drug govern aerosolisation behaviour of the blend and consequently the efficacy of the drug deposition...

  16. An attempt to understand glioma stem cell biology through centrality analysis of a protein interaction network.

    Science.gov (United States)

    Mallik, Mrinmay Kumar

    2018-02-07

    Biological networks can be analyzed using "Centrality Analysis" to identify the more influential nodes and interactions in the network. This study was undertaken to create and visualize a biological network comprising of protein-protein interactions (PPIs) amongst proteins which are preferentially over-expressed in glioma cancer stem cell component (GCSC) of glioblastomas as compared to the glioma non-stem cancer cell (GNSC) component and then to analyze this network through centrality analyses (CA) in order to identify the essential proteins in this network and their interactions. In addition, this study proposes a new centrality analysis method pertaining exclusively to transcription factors (TFs) and interactions amongst them. Moreover the relevant molecular functions, biological processes and biochemical pathways amongst these proteins were sought through enrichment analysis. A protein interaction network was created using a list of proteins which have been shown to be preferentially expressed or over-expressed in GCSCs isolated from glioblastomas as compared to the GNSCs. This list comprising of 38 proteins, created using manual literature mining, was submitted to the Reactome FIViz tool, a web based application integrated into Cytoscape, an open source software platform for visualizing and analyzing molecular interaction networks and biological pathways to produce the network. This network was subjected to centrality analyses utilizing ranked lists of six centrality measures using the FIViz application and (for the first time) a dedicated centrality analysis plug-in ; CytoNCA. The interactions exclusively amongst the transcription factors were nalyzed through a newly proposed centrality analysis method called "Gene Expression Associated Degree Centrality Analysis (GEADCA)". Enrichment analysis was performed using the "network function analysis" tool on Reactome. The CA was able to identify a small set of proteins with consistently high centrality ranks that

  17. The Merapi Interactive Project: Offering a Fancy Cross-Disciplinary Scientific Understanding of Merapi Volcano to a Wide Audience.

    Science.gov (United States)

    Morin, J.; Kerlow, I.

    2015-12-01

    The Merapi volcano is of great interest to a wide audience as it is one of the most dangerous volcanoes worldwide and a beautiful touristic spot. The scientific literature available on that volcano both in Earth and Social sciences is rich but mostly inaccessible to the public because of the scientific jargon and the restricted database access. Merapi Interactive aims at developing clear information and attractive content about Merapi for a wide audience. The project is being produced by the Art and Media Group at the Earth Observatory of Singapore, and it takes the shape of an e-book. It offers a consistent, comprehensive, and jargon-filtered synthesis of the main volcanic-risk related topics about Merapi: volcanic mechanisms, eruptive history, associated hazards and risks, the way inhabitants and scientists deal with it, and what daily life at Merapi looks like. The project provides a background to better understand volcanoes, and it points out some interactions between scientists and society. We propose two levels of interpretation: one that is understandable by 10-year old kids and above and an expert level with deeper presentations of specific topics. Thus, the Merapi Interactive project intends to provide an engaging and comprehensive interactive book that should interest kids, adults, as well as Earth Sciences undergraduates and academics. Merapi Interactive is scheduled for delivery in mid-2016.

  18. Teaching Interaction Design and Children: Understanding the Relevance of Theory for Design

    Directory of Open Access Journals (Sweden)

    Tilde Bekker

    2014-08-01

    Full Text Available In this paper we address the challenge of teaching interaction design for children’s products especially pertaining to bridging the gap between child development theories and interaction design issues. We describe our experiences from developing a one-week course on interaction design and children, that is part of a competency based Masters program in design. We conclude that key elements in this course, to support learning how to incorporate theoretical knowledge in design, are a providing design tool that covers a child developmental model of four domains (cognitive, social, emotional and physical , such as the Developmentally Situated Design cards for creating child personas and design concepts b using a design exercise c giving students the possibility to work on several iterations d giving students more than one age-group to work with in the project, and e providing the students with an evaluation protocol.

  19. Understanding interactions in virtual HIV communities: a social network analysis approach.

    Science.gov (United States)

    Shi, Jingyuan; Wang, Xiaohui; Peng, Tai-Quan; Chen, Liang

    2017-02-01

    This study investigated the driving mechanism of building interaction ties among the people living with HIV/AIDS in one of the largest virtual HIV communities in China using social network analysis. Specifically, we explained the probability of forming interaction ties with homophily and popularity characteristics. The exponential random graph modeling results showed that members in this community tend to form homophilous ties in terms of shared location and interests. Moreover, we found a tendency away from popularity effect. This suggests that in this community, resources and information were not disproportionally received by a few of members, which could be beneficial to the overall community.

  20. Can toxicokinetic and toxicodynamic modeling be used to understand and predict synergistic interactions between chemicals?

    DEFF Research Database (Denmark)

    Cedergreen, Nina; Dalhoff, Kristoffer; Li, Dan

    2017-01-01

    including synergists. The aim of the present study is to develop a mechanistic toxicokinetic (TK) and toxicodynamic (TD) model for the synergistic mixture of the azole fungicide, propiconazole (the synergist), and the insecticide, α-cypermethrin, on the mortality of the crustacean Daphnia magna. The study...... by their effect on the biotransformation rate but that this effect could only partly be explained by the effect of the two azoles on cytochrome P450 activity, measured on D. magna in vivo. TKTD models of interacting mixtures seem to be a promising tool to test mechanisms of interactions between chemicals...

  1. A perspective on multi-user interaction design based on an understanding of domestic lighting conflict

    NARCIS (Netherlands)

    Niemantsverdriet, K.; van Essen, H.A.; Eggen, J.H.

    2017-01-01

    More and more connected systems are entering the social and shared home environment. Interaction with these systems is often rather individual and based on personal preferences, leading to conflicts in multi-user situations. In this paper, we aim to develop a perspective on how to design for

  2. Upper Secondary Students' Understanding of the Basic Physical Interactions in Analogous Atomic and Solar Systems

    Science.gov (United States)

    Taber, Keith S.

    2013-01-01

    Comparing the atom to a "tiny solar system" is a common teaching analogy, and the extent to which learners saw the systems as analogous was investigated. English upper secondary students were asked parallel questions about the physical interactions between the components of a simple atomic system and a simple solar system to investigate…

  3. Understanding the electron-phonon interaction in polar crystals: Perspective presented by the vibronic theory

    Science.gov (United States)

    Pishtshev, A.; Kristoffel, N.

    2017-05-01

    We outline our novel results relating to the physics of the electron-TO-phonon (el-TO-ph) interaction in a polar crystal. We explained why the el-TO-ph interaction becomes effectively strong in a ferroelectric, and showed how the electron density redistribution establishes favorable conditions for soft-behavior of the long-wavelength branch of the active TO vibration. In the context of the vibronic theory it has been demonstrated that at the macroscopic level the interaction of electrons with the polar zone-centre TO phonons can be associated with the internal long-range dipole forces. Also we elucidated a methodological issue of how local field effects are incorporated within the vibronic theory. These result provided not only substantial support for the vibronic mechanism of ferroelectricity but also presented direct evidence of equivalence between vibronic and the other lattice dynamics models. The corresponding comparison allowed us to introduce the original parametrization for constants of the vibronic interaction in terms of key material constants. The applicability of the suggested formula has been tested for a wide class of polar materials.

  4. Understanding guide dog team interactions: design opportunities to support work and play

    NARCIS (Netherlands)

    Hauser, S.; Wakkary, R.L.; Neustaedter, C.

    2014-01-01

    The visually impaired have been a longstanding and well-recognized user group addressed in the field of Human-Computer Interaction (HCI). Recently, the study of sighted dog owners and their pets has gained interest in HCI. Despite this, there is a noticeable gap in the field with regards to research

  5. Understanding Information Sharing Among Scientists Through a Professional Online Community: Analyses on Interaction Patterns and Contents

    Directory of Open Access Journals (Sweden)

    Shin, Eun-Ja

    2017-12-01

    Full Text Available Even through many professional organizations increasingly use Q&A sites in their online communities for information sharing, there are few studies which examine what is really going on in the Q&A activities in professional online communities (POC. This study aims to examine the interaction patterns and contents posted in the Q&A site of a POC, KOSEN, a science and technology online community in South Korea, focusing on how actively scientific information and knowledge are shared. The interaction patterns among the participants were identified through social network analysis (SNA and the contents in the Q&As were examined by content analysis. The results show that the overall network indicated a moderate level of participation and connection and answerers especially tended to be active. Also, there are different interaction patterns depending on academic fields. Relatively few participants were posting leaders who seemed to steer the overall interactions. Furthermore, some content related to manipulation and explanation for experiments, which are in urgent need, seem to be posted in the sites more frequently with more amounts. Combining both SNA and content analysis, this study demonstrated how actively information and knowledge is shared and what types of contents are exchanged. The findings have practical implications for POC managers and practitioners.

  6. Understanding soaring bird migration through interactions and decisions at the individual level

    NARCIS (Netherlands)

    van Loon, E.E.; Shamoun-Baranes, J.; Bouten, W.; Davis, S.L.

    2011-01-01

    Many soaring bird species migrate southwards in autumn from their breeding grounds in Europe and Central Asia towards their wintering grounds. Our knowledge about interactions between migrating birds, thermal selection during migration and mechanisms that lead to flocking or convergent travel

  7. Towards Understanding the Two Way Interaction Effects of Extraversion and Openness to Experience on Career Commitment

    Science.gov (United States)

    Arora, Ridhi; Rangnekar, Santosh

    2016-01-01

    In this study, we examined potential two-way interaction effects of the Big Five personality traits extraversion and openness to experience on career commitment measured in terms of three components of career identity, career resilience, and career planning. Participants included 450 managers from public and private sector organizations in North…

  8. Multiple stressor effects in Chlamydomonas reinhardtii – Toward understanding mechanisms of interaction between effects of ultraviolet radiation and chemical pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Korkaric, Muris [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600, Duebendorf (Switzerland); ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich (Switzerland); Behra, Renata; Fischer, Beat B. [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600, Duebendorf (Switzerland); Junghans, Marion [Swiss Center for Applied Ecotoxicology Eawag-EPFL, 8600, Duebendorf (Switzerland); Eggen, Rik I.L., E-mail: rik.eggen@eawag.ch [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600, Duebendorf (Switzerland); ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich (Switzerland)

    2015-05-15

    Highlights: • Systematic study of multiple stressor effects of UVR and chemicals in C. reinhardtii. • UVR and chemicals did not act independently on algal photosynthesis and reproduction. • Multiple stressor effects of UVR and chemicals depended on chemical MOA. • Synergistic effect interactions not limited to oxidative stress inducing chemicals. • Multiple MOAs of UVR may limit applicability of current prediction models. - Abstract: The effects of chemical pollutants and environmental stressors, such as ultraviolet radiation (UVR), can interact when organisms are simultaneously exposed, resulting in higher (synergistic) or lower (antagonistic) multiple stressor effects than expected based on the effects of single stressors. Current understanding of interactive effects is limited due to a lack of mechanism-based multiple stressor studies. It has been hypothesized that effect interactions may generally occur if chemical and non-chemical stressors cause similar physiological effects in the organism. To test this hypothesis, we exposed the model green alga Chlamydomonas reinhardtii to combinations of UVR and single chemicals displaying modes of action (MOA) similar or dissimilar to the impact of UVR on photosynthesis. Stressor interactions were analyzed based on the independent action model. Effect interactions were found to depend on the MOA of the chemicals, and also on their concentrations, the exposure time and the measured endpoint. Indeed, only chemicals assumed to cause effects on photosynthesis similar to UVR showed interactions with UVR on photosynthetic yield: synergistic in case of Cd(II) and paraquat and antagonistic in case of diuron. No interaction on photosynthesis was observed for S-metolachlor, which acts dissimilarly to UVR. However, combined effects of S-metolachlor and UVR on algal reproduction were synergistic, highlighting the importance of considering additional MOA of UVR. Possible mechanisms of stressor effect interactions are

  9. Multiple stressor effects in Chlamydomonas reinhardtii – Toward understanding mechanisms of interaction between effects of ultraviolet radiation and chemical pollutants

    International Nuclear Information System (INIS)

    Korkaric, Muris; Behra, Renata; Fischer, Beat B.; Junghans, Marion; Eggen, Rik I.L.

    2015-01-01

    Highlights: • Systematic study of multiple stressor effects of UVR and chemicals in C. reinhardtii. • UVR and chemicals did not act independently on algal photosynthesis and reproduction. • Multiple stressor effects of UVR and chemicals depended on chemical MOA. • Synergistic effect interactions not limited to oxidative stress inducing chemicals. • Multiple MOAs of UVR may limit applicability of current prediction models. - Abstract: The effects of chemical pollutants and environmental stressors, such as ultraviolet radiation (UVR), can interact when organisms are simultaneously exposed, resulting in higher (synergistic) or lower (antagonistic) multiple stressor effects than expected based on the effects of single stressors. Current understanding of interactive effects is limited due to a lack of mechanism-based multiple stressor studies. It has been hypothesized that effect interactions may generally occur if chemical and non-chemical stressors cause similar physiological effects in the organism. To test this hypothesis, we exposed the model green alga Chlamydomonas reinhardtii to combinations of UVR and single chemicals displaying modes of action (MOA) similar or dissimilar to the impact of UVR on photosynthesis. Stressor interactions were analyzed based on the independent action model. Effect interactions were found to depend on the MOA of the chemicals, and also on their concentrations, the exposure time and the measured endpoint. Indeed, only chemicals assumed to cause effects on photosynthesis similar to UVR showed interactions with UVR on photosynthetic yield: synergistic in case of Cd(II) and paraquat and antagonistic in case of diuron. No interaction on photosynthesis was observed for S-metolachlor, which acts dissimilarly to UVR. However, combined effects of S-metolachlor and UVR on algal reproduction were synergistic, highlighting the importance of considering additional MOA of UVR. Possible mechanisms of stressor effect interactions are

  10. An Interactive Modeling Lesson Increases Students' Understanding of Ploidy during Meiosis

    Science.gov (United States)

    Wright, L. Kate; Newman, Dina L.

    2011-01-01

    Chromosome structure is confusing to students at all levels, and chromosome behavior during meiosis is a notoriously difficult topic. Undergraduate biology majors are exposed to the process of meiosis numerous times during their presecondary and postsecondary education, yet understanding of key concepts, such as the point at which haploidy is…

  11. Argument Construction in Understanding Noncovalent Interactions: A Comparison of Two Argumentation Frameworks

    Science.gov (United States)

    Cooper, A. Kat; Oliver-Hoyo, M. T.

    2016-01-01

    Argument construction is a valuable ability for explaining scientific phenomena and introducing argumentation skills as part of a curriculum can greatly enhance student understanding by promoting self-reflection on the topic under investigation. This article aims to use argument construction as a technique to support an activity designed to…

  12. Using Interactive Technology to Support Students' Understanding of the Greenhouse Effect and Global Warming

    Science.gov (United States)

    Varma, Keisha; Linn, Marcia C.

    2012-01-01

    In this work, we examine middle school students' understanding of the greenhouse effect and global warming. We designed and refined a technology-enhanced curriculum module called "Global Warming: Virtual Earth". In the module activities, students conduct virtual experiments with a visualization of the greenhouse effect. They analyze data and draw…

  13. A First Step toward the Automatic Understanding of Social Touch for Naturalistic Human–Robot Interaction

    NARCIS (Netherlands)

    Jung, Merel Madeleine; Poel, Mannes; Reidsma, Dennis; Heylen, Dirk K.J.

    2017-01-01

    Social robots should be able to automatically understand and respond to human touch. The meaning of touch does not only depend on the form of touch but also on the context in which the touch takes place. To gain more insight into the factors that are relevant to interpret the meaning of touch within

  14. Understanding “Baby Boomers” and “Millennials” motivations to interact with brands on Social Media

    OpenAIRE

    Oliveira, Rute Sofia Matos de

    2017-01-01

    The emergence and importance of social media and, in particular, social networking sites (SNS), has made it possible for an accessible integration between consumers and brands, by providing unlimited reasons for users to express, share and create content. The aim of this dissertation is to explore what motivates consumers to interact with brands on social media and to understand the relevance of those variables in explaining consumers’ loyalty toward a brand. Members of two distinct genera...

  15. Social meanings and understandings in patient-nurse interaction in the community practice setting: a grounded theory study

    Directory of Open Access Journals (Sweden)

    Stoddart Kathleen M

    2012-09-01

    Full Text Available Abstract Background The patient-nurse relationship is a traditional concern of healthcare research. However, patient-nurse interaction is under examined from a social perspective. Current research focuses mostly on specific contexts of care delivery and experience related to medical condition or illness, or to nurses’ speciality. Consequentially, this paper is about the social meanings and understandings at play within situated patient-nurse interaction in the community practice setting in a transforming healthcare service. Methods Grounded theory methodology was used and the research process was characterised by principles of theoretical sensitivity and constant comparative analysis. The field of study was four health centres in the community. The participants were patients and nurses representative of those attending or working in the health centres and meeting there by scheduled appointment. Data collection methods were observations, informal interviews and semi-structured interviews. Results Key properties of ‘Being a good patient, being a good nurse’, ‘Institutional experiences’ and ‘Expectations about healthcare’ were associated with the construction of a category entitled ‘Experience’. Those key properties captured that in an evolving healthcare environment individuals continually re-constructed their reality of being a patient or nurse as they endeavoured to perform appropriately; articulation of past and present healthcare experiences was important in that process. Modus operandi in role as patient was influenced by past experiences in healthcare and by those in non-healthcare institutions in terms of engagement and involvement (or not in interaction. Patients’ expectations about interaction in healthcare included some uncertainly as they strived to make sense of the changing roles and expertise of nurses and, differentiating between the roles and expertise of nurses and doctors. Conclusions The importance of social

  16. Mechanistic understanding of nanoparticles' interactions with extracellular matrix: the cell and immune system.

    Science.gov (United States)

    Engin, Ayse Basak; Nikitovic, Dragana; Neagu, Monica; Henrich-Noack, Petra; Docea, Anca Oana; Shtilman, Mikhail I; Golokhvast, Kirill; Tsatsakis, Aristidis M

    2017-06-24

    Extracellular matrix (ECM) is an extraordinarily complex and unique meshwork composed of structural proteins and glycosaminoglycans. The ECM provides essential physical scaffolding for the cellular constituents, as well as contributes to crucial biochemical signaling. Importantly, ECM is an indispensable part of all biological barriers and substantially modulates the interchange of the nanotechnology products through these barriers. The interactions of the ECM with nanoparticles (NPs) depend on the morphological characteristics of intercellular matrix and on the physical characteristics of the NPs and may be either deleterious or beneficial. Importantly, an altered expression of ECM molecules ultimately affects all biological processes including inflammation. This review critically discusses the specific behavior of NPs that are within the ECM domain, and passing through the biological barriers. Furthermore, regenerative and toxicological aspects of nanomaterials are debated in terms of the immune cells-NPs interactions.

  17. [Use of laws of interelement interactions for understanding of mechanisms of various human diseases].

    Science.gov (United States)

    Barashkov, G K; Zaĭtseva, L I

    2008-01-01

    The review considers the basic laws of interaction of elements in real physiological conditions of metabolism. The law of replacement and two it consequences have been formulated taking into account a major principle of cybernetics, the feedback principle. A rule of a fractional threshold and the law of toxicity based on the Mertz's rules have been formulated. These laws have been used here for consideration of mechanisms of occurrence and development of apoptosis and also side-effects of statins. Study of bioinorganic mechanisms of different diseases is a erspective way for search of complex connections of metals and ligands, capable to interaction with initiators of chain reactions, and for a finding of substances--inhibitors these reactions.

  18. Understanding the nanoscale local buckling behavior of vertically aligned MWCNT arrays with van der Waals interactions

    Science.gov (United States)

    Li, Yupeng; Kim, Hyung-Ick; Wei, Bingqing; Kang, Junmo; Choi, Jae-Boong; Nam, Jae-Do; Suhr, Jonghwan

    2015-08-01

    The local buckling behavior of vertically aligned carbon nanotubes (VACNTs) has been investigated and interpreted in the view of a collective nanotube response by taking van der Waals interactions into account. To the best of our knowledge, this is the first report on the case of collective VACNT behavior regarding van der Waals force among nanotubes as a lateral support effect during the buckling process. The local buckling propagation and development of VACNTs were experimentally observed and theoretically analyzed by employing finite element modeling with lateral support from van der Waals interactions among nanotubes. Both experimental and theoretical analyses show that VACNTs buckled in the bottom region with many short waves and almost identical wavelengths, indicating a high mode buckling. Furthermore, the propagation and development mechanism of buckling waves follow the wave damping effect.The local buckling behavior of vertically aligned carbon nanotubes (VACNTs) has been investigated and interpreted in the view of a collective nanotube response by taking van der Waals interactions into account. To the best of our knowledge, this is the first report on the case of collective VACNT behavior regarding van der Waals force among nanotubes as a lateral support effect during the buckling process. The local buckling propagation and development of VACNTs were experimentally observed and theoretically analyzed by employing finite element modeling with lateral support from van der Waals interactions among nanotubes. Both experimental and theoretical analyses show that VACNTs buckled in the bottom region with many short waves and almost identical wavelengths, indicating a high mode buckling. Furthermore, the propagation and development mechanism of buckling waves follow the wave damping effect. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03581c

  19. Understanding the Effect of Audio Communication Delay on Distributed Team Interaction

    Science.gov (United States)

    2013-06-01

    means for members to socialize and learn about each other, engenders development cooperative relationships, and lays a foundation for future interaction...length will result in increases in task completion time and mental workload. 3. Audiovisual technology will moderate the effect of communication...than audio alone. 4. Audiovisual technology will moderate the effect of communication delays such that task completion time and mental workload will

  20. Pathways of understanding: The interactions of humanity and global environmental change

    International Nuclear Information System (INIS)

    Jacobson, H.K.; Katzenberger, J.; Lousma, J.; Mooney, H.A.; Moss, R.H.; Kuhn, W.; Luterbacher, U.; Wiegandt, E.

    1992-01-01

    How humans, interacting within social systems, affect and are affected by global change is explored. Recognizing the impact human activities have on the environment and responding to the need to document the interactions among human activities, the Consortium for International Earth Science Information Network (CIESIN) commissioned a group of 12 scientists to develop a framework illustrating the key human systems that contribute to global change. This framework, called the Social Process Diagram, will help natural and social scientists, educators, resource managers and policy makers envision and analyze how human systems interact among themselves and with the natural system. The Social Process Diagram consists of the following blocks that constitute the Diagram's structural framework: (1) fund of knowledge and experience; (2) preferences and expectations; (3) factors of production and technology; (4) population and social structure; (5) economic systems; (6) political systems and institutions; and (7) global scale environmental processes. To demonstrate potential ways the Diagram can be used, this document includes 3 hypothetical scenarios of global change issues: global warming and sea level rise; the environmental impact of human population migration; and energy and the environment. These scenarios demonstrate the Diagram's usefulness for visualizing specific processes that might be studied to evaluate a particular global change issues. The scenario also shows that interesting and unanticipated questions may emerge as links are explored between categories on the Diagram

  1. Pathways of Understanding: the Interactions of Humanity and Global Environmental Change

    Science.gov (United States)

    Jacobson, Harold K.; Katzenberger, John; Lousma, Jack; Mooney, Harold A.; Moss, Richard H.; Kuhn, William; Luterbacher, Urs; Wiegandt, Ellen

    1992-01-01

    How humans, interacting within social systems, affect and are affected by global change is explored. Recognizing the impact human activities have on the environment and responding to the need to document the interactions among human activities, the Consortium for International Earth Science Information Network (CIESIN) commissioned a group of 12 scientists to develop a framework illustrating the key human systems that contribute to global change. This framework, called the Social Process Diagram, will help natural and social scientists, educators, resource managers and policy makers envision and analyze how human systems interact among themselves and with the natural system. The Social Process Diagram consists of the following blocks that constitute the Diagram's structural framework: (1) fund of knowledge and experience; (2) preferences and expectations; (3) factors of production and technology; (4) population and social structure; (5) economic systems; (6) political systems and institutions; and (7) global scale environmental processes. To demonstrate potential ways the Diagram can be used, this document includes 3 hypothetical scenarios of global change issues: global warming and sea level rise; the environmental impact of human population migration; and energy and the environment. These scenarios demonstrate the Diagram's usefulness for visualizing specific processes that might be studied to evaluate a particular global change issues. The scenario also shows that interesting and unanticipated questions may emerge as links are explored between categories on the Diagram.

  2. Biosensors paving the way to understanding the interaction between cadmium and the estrogen receptor alpha.

    Directory of Open Access Journals (Sweden)

    Peter Fechner

    Full Text Available Cadmium is a toxic heavy metal ubiquitously present in the environment and subsequently in the human diet. Cadmium has been proposed to disrupt the endocrine system, targeting in particular the estrogen signaling pathway already at environmentally relevant concentrations. Thus far, the reports on the binding affinity of cadmium towards human estrogen receptor alpha (hERα have been contradicting, as have been the reports on the in vivo estrogenicity of cadmium. Hence, the mode of interaction between cadmium and the receptor remains unclear. Here, we investigated the interaction between cadmium and hERα on a molecular level by applying a novel, label-free biosensor technique based on reflectometric interference spectroscopy (RIfS. We studied the binding of cadmium to hERα, and the conformation of the receptor following cadmium treatment. Our data reveals that cadmium interacts with the ligand binding domain (LBD of the ERα and affects the conformation of the receptor. However, the binding event, as well as the induced conformation change, greatly depends on the accessibility of the cysteine tails in the LBD. As the LBD cysteine residues have been reported as targets of post-translational modifications in vivo, we present a hypothesis according to which different cellular pools of ERα respond to cadmium differently. Our proposed theory could help to explain some of the previously contradicting results regarding estrogen-like activity of cadmium.

  3. Recent advances in the understanding of the interaction of antidepressant drugs with serotonin and norepinephrine transporters

    DEFF Research Database (Denmark)

    Andersen, Jacob; Kristensen, Anders Skov; Bang-Andersen, Benny

    2009-01-01

    The biogenic monoamine transporters are integral membrane proteins that perform active transport of extracellular dopamine, serotonin and norepinephrine into cells. These transporters are targets for therapeutic agents such as antidepressants, as well as addictive substances such as cocaine...... and amphetamine. Seminal advances in the understanding of the structure and function of this transporter family have recently been accomplished by structural studies of a bacterial transporter, as well as medicinal chemistry and pharmacological studies of mammalian transporters. This feature article focuses...

  4. Using Interactive Case Studies to Support Students Understandings of Local Environmental Problems

    Directory of Open Access Journals (Sweden)

    Z. Kostova

    2012-12-01

    Full Text Available The article presents designed and refined an interactive-enhanced curriculum module for 9th grade secondary school students in Bulgaria, based on environmental case studies. In the module activities students from two schools studied the local environments, performed observations and experiments, collected and analyzed data, prepared and presented posters and role plays, made connections between scientific processes and socio-scientific issues and drew conclusions about the global effects of locally created environmental problems. The students’ critical observations of the quality of their surroundings helped them to make a list of local environmental problems, to apply interactive strategies in studying them and to propose rational scientifically based solutions. In the study the attention was directed to the advantages and disadvantages of poster presentations and role playing and to the specific learning difficulties that students had to overcome. Students’ achievements from the two experimental schools were assessed independently in order to give us insights into the details of learning using different interactive strategies and into the acquired performance skills, dependant on students’ interests and personal abilities. The three versions of the module (traditional, dominated by teacher presentation; poster preparation and presentation in which students imitate scientific team research; and role playing in which students not only study the local environmental problems but assume social roles to cope with them demonstrate three levels of students learning independence. Specific assessment tests and check lists were developed for analyzing, evaluating and comparing students’ achievements in each version of the module and in each school. Ecological knowledge assessment tests were based on Bloom’s taxonomy of educational objectives. Poster and role playing preparations and presentations were assessed by specific criteria, shown in the

  5. Interactive tool that empowers structural understanding and enables FEM analysis in a parametric design environment

    DEFF Research Database (Denmark)

    Christensen, Jesper Thøger; Parigi, Dario; Kirkegaard, Poul Henning

    2014-01-01

    This paper introduces an interactive tool developed to integrate structural analysis in the architectural design environment from the early conceptual design stage. The tool improves exchange of data between the design environment of Rhino Grasshopper and the FEM analysis of Autodesk Robot...... Structural Analysis. Further the tool provides intuitive setup and visual aids in order to facilitate the process. Enabling students and professionals to quickly analyze and evaluate multiple design variations. The tool has been developed inside the Performance Aided Design course at the Master...... of Architecture and Design at Aalborg University...

  6. Understanding and improving the efficiency of full configuration interaction quantum Monte Carlo.

    Science.gov (United States)

    Vigor, W A; Spencer, J S; Bearpark, M J; Thom, A J W

    2016-03-07

    Within full configuration interaction quantum Monte Carlo, we investigate how the statistical error behaves as a function of the parameters which control the stochastic sampling. We define the inefficiency as a measure of the statistical error per particle sampling the space and per time step and show there is a sizeable parameter regime where this is minimised. We find that this inefficiency increases sublinearly with Hilbert space size and can be reduced by localising the canonical Hartree-Fock molecular orbitals, suggesting that the choice of basis impacts the method beyond that of the sign problem.

  7. Understanding and improving the efficiency of full configuration interaction quantum Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Vigor, W. A.; Bearpark, M. J. [Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Spencer, J. S. [Department of Physics, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Thom, A. J. W. [Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); University Chemical Laboratory, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2016-03-07

    Within full configuration interaction quantum Monte Carlo, we investigate how the statistical error behaves as a function of the parameters which control the stochastic sampling. We define the inefficiency as a measure of the statistical error per particle sampling the space and per time step and show there is a sizeable parameter regime where this is minimised. We find that this inefficiency increases sublinearly with Hilbert space size and can be reduced by localising the canonical Hartree–Fock molecular orbitals, suggesting that the choice of basis impacts the method beyond that of the sign problem.

  8. Understanding the Work-Life Interaction from a Working Time Perspective

    DEFF Research Database (Denmark)

    Pedersen, Vivi Bach

    time not only defines the temporal structure of work, but also determines the individual’s social time. The theoretical framework is based on theories concerning influence, in particular Organizational Participation (e.g. Heller, Pusic, Strauss & Wilpert, 1998) and Self-Determination Theory (e.g. Deci...... & Ryan, 2002). Through theoretical analyses it is shown that a participatory influence approach reveals new perspectives in understanding the complexity of the work-life phenomenon and help counteracting the undesirable split-up between the existing conflict versus balance approaches. Participants from...

  9. Towards understanding the trajectory and interactions of the gut microbiome in healthy older humans

    DEFF Research Database (Denmark)

    Castro Mejia, Josue Leonardo

    The human gastrointestinal tract (GIT) is inhabited by a vast amount of microorganisms from different domains of life collectively denominated the gut microbiome (GM). Among its numerous functions, GM plays a crucial role in developing the immune system in early-life and contributes to maintain...... by food-selectivity (pickiness) and associated patterns of carbohydrates’ consumption (and total energy), reflecting changes in GM composition that corresponded with signs of glucoseintolerance. Lastly, in order to gain understanding on the role of viral communities in the gut of older adults, we...

  10. Interactive simulations for promoting transdisciplinary understanding: a case study of the Western Cape fisheries, South Africa

    Directory of Open Access Journals (Sweden)

    Cecile Proches

    2012-07-01

    Full Text Available Simulations have proven beneficial in enabling participants from various backgrounds to meaningfully engage in learning from experience. The aim of this paper is to investigate how interactive simulations can play a role in navigating the changes faced in a multi- stakeholder setting, characterised by users dependent on marine resources and an authorising institution. Relevant literature in the areas of simulation and gaming, change management, systems thinking, and complexity theory was examined. A qualitative research approach and purposive sampling were employed. Interviews were first conducted with diverse stakeholders in the Western Cape fisheries of South Africa to determine the issues. A simulation was thereafter designed. The main findings from this study indicate that simulation use illustrates how the various stakeholders in a system interact, and how their actions and decisions influence each other. The simulation may be used in other areas of natural resource management, as well as in other kinds of multi- stakeholder scenarios. Keywords: Simulation and gaming, Change management, Fisheries, Multi-stakeholder scenarios, Systems thinking, Complexity theory Disciplines: Conflict Resolution, Leadership Studies, Management Studies, Natural Resource Management

  11. Understanding AuNP interaction with low-generation PAMAM dendrimers: a CIELab and deconvolution study

    International Nuclear Information System (INIS)

    Jimenez-Ruiz, A.; Carnerero, J. M.; Castillo, P. M.; Prado-Gotor, R.

    2017-01-01

    Low-generation polyamidoamine (PAMAM) dendrimers are known to adsorb on the surface of gold nanoparticles (AuNPs) causing aggregation and color changes. In this paper, a thorough study of this affinity using absorption spectroscopy, colorimetric, and emission methods has been carried out. Results show that, for citrate-capped gold nanoparticles, interaction with the dendrimer is not only of an electrostatic character but instead occurs, at least in part, through the dendrimer’s uncharged internal amino groups. The possibilities of the CIELab chromaticity system parameters’ evolution have also been explored in order to quantify dendrimer interaction with the red-colored nanoparticles. By measuring and quantifying 17 nm citrate-capped AuNP color changes, which are strongly dependant on their aggregation state, binding free energies are obtained for the first time for these systems. Results are confirmed via an alternate fitting method which makes use of deconvolution parameters from absorbance spectra. Binding free energies obtained through the use of both means are in good agreement with each other.

  12. A new analytical approach to understanding nanoscale lead-iron interactions in drinking water distribution systems.

    Science.gov (United States)

    Trueman, Benjamin F; Gagnon, Graham A

    2016-07-05

    High levels of iron in distributed drinking water often accompany elevated lead release from lead service lines and other plumbing. Lead-iron interactions in drinking water distribution systems are hypothesized to be the result of adsorption and transport of lead by iron oxide particles. This mechanism was explored using point-of-use drinking water samples characterized by size exclusion chromatography with UV and multi-element (ICP-MS) detection. In separations on two different stationary phases, high apparent molecular weight (>669 kDa) elution profiles for (56)Fe and (208)Pb were strongly correlated (average R(2)=0.96, N=73 samples representing 23 single-unit residences). Moreover, (56)Fe and (208)Pb peak areas exhibited an apparent linear dependence (R(2)=0.82), consistent with mobilization of lead via adsorption to colloidal particles rich in iron. A UV254 absorbance peak, coincident with high molecular weight (56)Fe and (208)Pb, implied that natural organic matter was interacting with the hypothesized colloidal species. High molecular weight UV254 peak areas were correlated with both (56)Fe and (208)Pb peak areas (R(2)=0.87 and 0.58, respectively). On average, 45% (std. dev. 10%) of total lead occurred in the size range 0.05-0.45 μm. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Investigation of corner shock boundary layer interactions to understand inlet unstart

    Science.gov (United States)

    Funderburk, Morgan

    2015-11-01

    Inlet unstart is a detrimental phenomenon in dual-mode ramjet/scramjet engines that causes severe loss of thrust, large transient structural load, and potentially a loss of the aircraft. In order to analyze the effects that the corner shock boundary layer interaction (SBLI) has on initiating and perpetuating inlet unstart, a qualitative and quantitative investigation into mean and dynamic features of corner SBLI at various Mach numbers is made. Surface streakline visualization showed that the corner SBLI is highly three-dimensional with a dominant presence of corner separation vortex. Further, the peak r.m.s. pressure was located at the periphery of corner separation vortex, suggesting that the unsteady loading is caused by the corner vortex. Power spectral densities of wall-pressure fluctuations in the peak r.m.s. location were analyzed in order to characterize the dominant frequencies of oscillation of the flow structures and to unravel the dynamic interactions between them in order to expand the operating margin of future hypersonic air breathing vehicles.

  14. Understanding AuNP interaction with low-generation PAMAM dendrimers: a CIELab and deconvolution study

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Ruiz, A., E-mail: ailjimrui@alum.us.es; Carnerero, J. M.; Castillo, P. M.; Prado-Gotor, R., E-mail: pradogotor@us.es [University of Seville, The Department of Physical Chemistry (Spain)

    2017-01-15

    Low-generation polyamidoamine (PAMAM) dendrimers are known to adsorb on the surface of gold nanoparticles (AuNPs) causing aggregation and color changes. In this paper, a thorough study of this affinity using absorption spectroscopy, colorimetric, and emission methods has been carried out. Results show that, for citrate-capped gold nanoparticles, interaction with the dendrimer is not only of an electrostatic character but instead occurs, at least in part, through the dendrimer’s uncharged internal amino groups. The possibilities of the CIELab chromaticity system parameters’ evolution have also been explored in order to quantify dendrimer interaction with the red-colored nanoparticles. By measuring and quantifying 17 nm citrate-capped AuNP color changes, which are strongly dependant on their aggregation state, binding free energies are obtained for the first time for these systems. Results are confirmed via an alternate fitting method which makes use of deconvolution parameters from absorbance spectra. Binding free energies obtained through the use of both means are in good agreement with each other.

  15. From idea to blah! understanding mobile services development as interactive innovation

    Directory of Open Access Journals (Sweden)

    Eduardo Fontana

    2005-08-01

    Full Text Available Mobile communications are permeating virtually every aspect of our lives. The market is experiencing rapid improvements in technologies, while mobile operators are trying to figure out new ways their infrastructures can provide services to the customers. Furthermore, user-innovation with new ways of using these technologies generates powerful feedback loops back into the innovation processes. In this turbulent environment it is difficult to capture and conceptualize how newness comes about and what the main characteristics of innovation are. The aim of this paper is to illustrate how the concept of interactive innovation can be applied to explain the development of mobile services. This study adopts the perspective of the developer rather than the user. Moreover, through the social construction of technology lens, the concepts of sense-making and bricolage are applied to explain the innovation appropriation process during the mobile data value chain improvement process. One of the conclusions drawn is that in the rapidly changing and complex context of mobile services development, the traditional notion of ‘interactive innovation’ cannot fully explain this phenomenon that takes place.

  16. An optimized, fast-to-perform mouse lung infection model with the human pathogen Chlamydia trachomatis for in vivo screening of antibiotics, vaccine candidates and modified host-pathogen interactions.

    Science.gov (United States)

    Dutow, Pavel; Wask, Lea; Bothe, Miriam; Fehlhaber, Beate; Laudeley, Robert; Rheinheimer, Claudia; Yang, Zhangsheng; Zhong, Guangming; Glage, Silke; Klos, Andreas

    2016-03-01

    Chlamydia trachomatis causes sexually transmitted diseases with infertility, pelvic inflammatory disease and neonatal pneumonia as complications. The duration of urogenital mouse models with the strict mouse pathogen C. muridarum addressing vaginal shedding, pathological changes of the upper genital tract or infertility is rather long. Moreover, vaginal C. trachomatis application usually does not lead to the complications feared in women. A fast-to-perform mouse model is urgently needed to analyze new antibiotics, vaccine candidates, immune responses (in gene knockout animals) or mutants of C. trachomatis. To complement the valuable urogenital model with a much faster and quantifiable screening method, we established an optimized lung infection model for the human intracellular bacterium C. trachomatis serovar D (and L2) in immunocompetent C57BL/6J mice. We demonstrated its usefulness by sensitive determination of antibiotic effects characterizing advantages and limitations achievable by early or delayed short tetracycline treatment and single-dose azithromycin application. Moreover, we achieved partial acquired protection in reinfection with serovar D indicating usability for vaccine studies, and showed a different course of disease in absence of complement factor C3. Sensitive monitoring parameters were survival rate, body weight, clinical score, bacterial load, histological score, the granulocyte marker myeloperoxidase, IFN-γ, TNF-α, MCP-1 and IL-6. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Evaluating role of interactive visualization tool in improving students' conceptual understanding of chemical equilibrium

    Science.gov (United States)

    Sampath Kumar, Bharath

    The purpose of this study is to examine the role of partnering visualization tool such as simulation towards development of student's concrete conceptual understanding of chemical equilibrium. Students find chemistry concepts abstract, especially at the microscopic level. Chemical equilibrium is one such topic. While research studies have explored effectiveness of low tech instructional strategies such as analogies, jigsaw, cooperative learning, and using modeling blocks, fewer studies have explored the use of visualization tool such as simulations in the context of dynamic chemical equilibrium. Research studies have identified key reasons behind misconceptions such as lack of systematic understanding of foundational chemistry concepts, failure to recognize the system is dynamic, solving numerical problems on chemical equilibrium in an algorithmic fashion, erroneous application Le Chatelier's principle (LCP) etc. Kress et al. (2001) suggested that external representation in the form of visualization is more than a tool for learning, because it enables learners to make meanings or express their ideas which cannot be readily done so through a verbal representation alone. Mixed method study design was used towards data collection. The qualitative portion of the study is aimed towards understanding the change in student's mental model before and after the intervention. A quantitative instrument was developed based on common areas of misconceptions identified by research studies. A pilot study was conducted prior to the actual study to obtain feedback from students on the quantitative instrument and the simulation. Participants for the pilot study were sampled from a single general chemistry class. Following the pilot study, the research study was conducted with a total of 27 students (N=15 in experimental group and N=12 in control group). Prior to participating in the study, students have completed their midterm test on the topic of chemical equilibrium. Qualitative

  18. I just ran a thousand analyses: benefits of multiple testing in understanding equivocal evidence on gene-environment interactions.

    Directory of Open Access Journals (Sweden)

    Vera E Heininga

    Full Text Available In psychiatric genetics research, the volume of ambivalent findings on gene-environment interactions (G x E is growing at an accelerating pace. In response to the surging suspicions of systematic distortion, we challenge the notion of chance capitalization as a possible contributor. Beyond qualifying multiple testing as a mere methodological issue that, if uncorrected, leads to chance capitalization, we advance towards illustrating the potential benefits of multiple tests in understanding equivocal evidence in genetics literature.We focused on the interaction between the serotonin-transporter-linked promotor region (5-HTTLPR and childhood adversities with regard to depression. After testing 2160 interactions with all relevant measures available within the Dutch population study of adolescents TRAILS, we calculated percentages of significant (p < .05 effects for several subsets of regressions. Using chance capitalization (i.e. overall significance rate of 5% alpha and randomly distributed findings as a competing hypothesis, we expected more significant effects in the subsets of regressions involving: 1 interview-based instead of questionnaire-based measures; 2 abuse instead of milder childhood adversities; and 3 early instead of later adversities. Furthermore, we expected equal significance percentages across 4 male and female subsamples, and 5 various genotypic models of 5-HTTLPR.We found differences in the percentages of significant interactions among the subsets of analyses, including those regarding sex-specific subsamples and genetic modeling, but often in unexpected directions. Overall, the percentage of significant interactions was 7.9% which is only slightly above the 5% that might be expected based on chance.Taken together, multiple testing provides a novel approach to better understand equivocal evidence on G x E, showing that methodological differences across studies are a likely reason for heterogeneity in findings - but chance

  19. Visualization of Host-Polerovirus Interaction Topologies Using Protein Interaction Reporter Technology.

    Science.gov (United States)

    DeBlasio, Stacy L; Chavez, Juan D; Alexander, Mariko M; Ramsey, John; Eng, Jimmy K; Mahoney, Jaclyn; Gray, Stewart M; Bruce, James E; Cilia, Michelle

    2016-02-15

    Demonstrating direct interactions between host and virus proteins during infection is a major goal and challenge for the field of virology. Most protein interactions are not binary or easily amenable to structural determination. Using infectious preparations of a polerovirus (Potato leafroll virus [PLRV]) and protein interaction reporter (PIR), a revolutionary technology that couples a mass spectrometric-cleavable chemical cross-linker with high-resolution mass spectrometry, we provide the first report of a host-pathogen protein interaction network that includes data-derived, topological features for every cross-linked site that was identified. We show that PLRV virions have hot spots of protein interaction and multifunctional surface topologies, revealing how these plant viruses maximize their use of binding interfaces. Modeling data, guided by cross-linking constraints, suggest asymmetric packing of the major capsid protein in the virion, which supports previous epitope mapping studies. Protein interaction topologies are conserved with other species in the Luteoviridae and with unrelated viruses in the Herpesviridae and Adenoviridae. Functional analysis of three PLRV-interacting host proteins in planta using a reverse-genetics approach revealed a complex, molecular tug-of-war between host and virus. Structural mimicry and diversifying selection-hallmarks of host-pathogen interactions-were identified within host and viral binding interfaces predicted by our models. These results illuminate the functional diversity of the PLRV-host protein interaction network and demonstrate the usefulness of PIR technology for precision mapping of functional host-pathogen protein interaction topologies. The exterior shape of a plant virus and its interacting host and insect vector proteins determine whether a virus will be transmitted by an insect or infect a specific host. Gaining this information is difficult and requires years of experimentation. We used protein interaction

  20. Understanding cellulose dissolution: energetics of interactions of ionic liquids and cellobiose revealed by solution microcalorimetry.

    Science.gov (United States)

    de Oliveira, Heitor Fernando Nunes; Rinaldi, Roberto

    2015-05-11

    In this report, the interactions between fifteen selected ionic liquids (ILs) and cellobiose (CB) are examined by high-precision solution microcalorimetry. The heat of mixing (Δmix H) of CB and ILs, or CB and IL/molecular solvent (MS) solutions, provides the first ever-published measure of the affinity of CB with ILs. Most importantly, we found that there is a very good correlation between the nature of the results found for Δmix H(CB) and the solubility behavior of cellulose. This correlation suggests that Δmix H(CB) offers a good estimate of the enthalpy of dissolution of cellulose even in solvents in which cellulose is insoluble. Therefore, the current findings open up new horizons for unravelling the intricacies of the thermodynamic factors accounting for the spontaneity of cellulose dissolution in ILs or IL/MS solutions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. The repository ecology an approach to understanding repository and service interactions

    CERN Document Server

    CERN. Geneva; Hagemann, Melissa

    2007-01-01

    An increasing number of university institutions and other organisations are deciding to deploy repositories and a growing number of formal and informal distributed services are supporting or capitalising on the information these repositories provide. Despite reasonably well understood technical architectures, early majority adopters may struggle to articulate their place within the actualities of a wider information environment. The idea of a repository ecology provides developers and administrators with a useful way of articulating and analysing their place in the information environment, and the technical and organisational interactions they have, or are developing, with other parts of such an environment. This presentation will provide an overview of the concept of a repository ecology and examine some examples from the domains of scholarly communications and elearning.

  2. Interactive Whiteboard Integration in Classrooms: Active Teachers Understanding about Their Training Process

    Science.gov (United States)

    Pujol, Meritxell Cortada; Quintana, Maria Graciela Badilla; Romaní, Jordi Riera

    With the incorporation in education of Information and Communication Technologies (ICT), especially the Interactive Whiteboard (IWB), emerges the need for a proper teacher training process due to adequate the integration and the didactic use of this tool in the classroom. This article discusses the teachers' perception on the training process for ICT integration. Its main aim is to contribute to the unification of minimum criteria for effective ICT implementation in any training process for active teachers. This case study begins from the development of a training model called Eduticom which was putted into practice in 4 schools in Catalonia, Spain. Findings indicated different teachers' needs such as an appropriate infrastructure, a proper management and a flexible training model which essentially addresses methodological and didactic aspects of IWB uses in the classroom.

  3. The repository ecology: an approach to understanding repository and service interactions

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    An increasing number of university institutions and other organisations are deciding to deploy repositories and a growing number of formal and informal distributed services are supporting or capitalising on the information these repositories provide. Despite reasonably well understood technical architectures, early majority adopters may struggle to articulate their place within the actualities of a wider information environment. The idea of a repository ecology provides developers and administrators with a useful way of articulating and analysing their place in the information environment, and the technical and organisational interactions they have, or are developing, with other parts of such an environment. This presentation will provide an overview of the concept of a repository ecology and examine some examples from the domains of scholarly communications and elearning. View John Robertson's biography

  4. Understanding the structural drivers governing glass-water interactions in borosilicate based model bioactive glasses.

    Science.gov (United States)

    Stone-Weiss, Nicholas; Pierce, Eric M; Youngman, Randall E; Gulbiten, Ozgur; Smith, Nicholas J; Du, Jincheng; Goel, Ashutosh

    2018-01-01

    The past decade has witnessed a significant upsurge in the development of borate and borosilicate based resorbable bioactive glasses owing to their faster degradation rate in comparison to their silicate counterparts. However, due to our lack of understanding about the fundamental science governing the aqueous corrosion of these glasses, most of the borate/borosilicate based bioactive glasses reported in the literature have been designed by "trial-and-error" approach. With an ever-increasing demand for their application in treating a broad spectrum of non-skeletal health problems, it is becoming increasingly difficult to design advanced glass formulations using the same conventional approach. Therefore, a paradigm shift from the "trial-and-error" approach to "materials-by-design" approach is required to develop new-generations of bioactive glasses with controlled release of functional ions tailored for specific patients and disease states, whereby material functions and properties can be predicted from first principles. Realizing this goal, however, requires a thorough understanding of the complex sequence of reactions that control the dissolution kinetics of bioactive glasses and the structural drivers that govern them. While there is a considerable amount of literature published on chemical dissolution behavior and apatite-forming ability of potentially bioactive glasses, the majority of this literature has been produced on silicate glass chemistries using different experimental and measurement protocols. It follows that inter-comparison of different datasets reveals inconsistencies between experimental groups. There are also some major experimental challenges or choices that need to be carefully navigated to unearth the mechanisms governing the chemical degradation behavior and kinetics of boron-containing bioactive glasses, and to accurately determine the composition-structure-property relationships. In order to address these challenges, a simplified

  5. Understanding of the Interaction between Clearance Leakage Flow and Main Passage Flow in a VGT Turbine

    Directory of Open Access Journals (Sweden)

    Ben Zhao

    2015-02-01

    Full Text Available The clearance flow between the nozzle and endwall in a variable geometry turbine (VGT has been numerically investigated to understand the clearance effect on the VGT performance and internal flow. It was found that the flow rate through turbine increases but the turbine efficiency decreases with height of clearance. Detailed flow field analyses indicated that most of the efficiency loss resulting from the leakage flow occurs at the upstream of the rotor area, that is, in the nozzle endwall clearance and between the nozzle vanes. There are two main mechanisms associated with this efficiency loss. One is due to the formation of the local vortex flow structure between the clearance flow and the main flow. The other is due to the impact of the clearance flow on the main flow after the nozzle throat. This impact reduces the span of shockwave with increased shockwave magnitude by changing the trajectory of the main flow.

  6. Transdisciplinary science: a path to understanding the interactions among ocean acidification, ecosystems, and society

    Science.gov (United States)

    Yates, Kimberly K.; Turley, Carol; Hopkinson, Brian M.; Todgham, Anne E.; Cross, Jessica N.; Greening, Holly; Williamson, Phillip; Van Hooidonk, Ruben; Deheyn, Dimitri D.; Johnson, Zachary

    2015-01-01

    The global nature of ocean acidification (OA) transcends habitats, ecosystems, regions, and science disciplines. The scientific community recognizes that the biggest challenge in improving understanding of how changing OA conditions affect ecosystems, and associated consequences for human society, requires integration of experimental, observational, and modeling approaches from many disciplines over a wide range of temporal and spatial scales. Such transdisciplinary science is the next step in providing relevant, meaningful results and optimal guidance to policymakers and coastal managers. We discuss the challenges associated with integrating ocean acidification science across funding agencies, institutions, disciplines, topical areas, and regions, and the value of unifying science objectives and activities to deliver insights into local, regional, and global scale impacts. We identify guiding principles and strategies for developing transdisciplinary research in the ocean acidification science community.

  7. Health Care Professionals' Understandings of Cross-Cultural Interaction in End-of-Life Care: A Focus Group Study.

    Science.gov (United States)

    Milberg, Anna; Torres, Sandra; Ågård, Pernilla

    2016-01-01

    The academic debate on cross-cultural interaction within the context of end-of-life care takes for granted that this interaction is challenging. However, few empirical studies have actually focused on what health care professionals think about this interaction. This study aimed to explore health care professionals' understandings of cross-cultural interaction during end-of-life care. Sixty end-of-life care professionals were recruited from eleven care units in Sweden to take part in focus group interviews. These interviews were analyzed using qualitative content analysis. The health care professionals interviewed talked about cross-cultural interaction in end-of-life care as interaction that brings about uncertainty, stress and frustration even though they had limited experience of this type of interaction. The focus group discussions brought attention to four specific challenges that they expected to meet when they care for patients with migrant backgrounds since they took for granted that they would have an ethno-cultural background that is different to their own. These challenges had to do with communication barriers, 'unusual' emotional and pain expressions, the expectation that these patients' families would be 'different' and the anticipation that these patients and their families lack knowledge. At the core of the challenges in question is the idea that cross-cultural interaction means meeting "the unknown". In addition, the end-of-life care professionals interviewed talked about patients whose backgrounds they did not share in homogenizing terms. It is against this backdrop that they worried about their ability to provide end-of-life care that is individualized enough to meet the needs of these patients. The study suggests that end-of-life care professionals who regard cross-cultural interaction in this manner could face actual challenges when caring for patients whose backgrounds they regard as "the unknown" since they anticipate a variety of challenges

  8. Health Care Professionals’ Understandings of Cross-Cultural Interaction in End-of-Life Care: A Focus Group Study

    Science.gov (United States)

    Torres, Sandra; Ågård, Pernilla

    2016-01-01

    Objective The academic debate on cross-cultural interaction within the context of end-of-life care takes for granted that this interaction is challenging. However, few empirical studies have actually focused on what health care professionals think about this interaction. This study aimed to explore health care professionals’ understandings of cross-cultural interaction during end-of-life care. Methods Sixty end-of-life care professionals were recruited from eleven care units in Sweden to take part in focus group interviews. These interviews were analyzed using qualitative content analysis. Results The health care professionals interviewed talked about cross-cultural interaction in end-of-life care as interaction that brings about uncertainty, stress and frustration even though they had limited experience of this type of interaction. The focus group discussions brought attention to four specific challenges that they expected to meet when they care for patients with migrant backgrounds since they took for granted that they would have an ethno-cultural background that is different to their own. These challenges had to do with communication barriers, ‘unusual’ emotional and pain expressions, the expectation that these patients’ families would be ‘different’ and the anticipation that these patients and their families lack knowledge. At the core of the challenges in question is the idea that cross-cultural interaction means meeting “the unknown”. In addition, the end-of-life care professionals interviewed talked about patients whose backgrounds they did not share in homogenizing terms. It is against this backdrop that they worried about their ability to provide end-of-life care that is individualized enough to meet the needs of these patients. Conclusions The study suggests that end-of-life care professionals who regard cross-cultural interaction in this manner could face actual challenges when caring for patients whose backgrounds they regard as

  9. Health Care Professionals' Understandings of Cross-Cultural Interaction in End-of-Life Care: A Focus Group Study.

    Directory of Open Access Journals (Sweden)

    Anna Milberg

    Full Text Available The academic debate on cross-cultural interaction within the context of end-of-life care takes for granted that this interaction is challenging. However, few empirical studies have actually focused on what health care professionals think about this interaction. This study aimed to explore health care professionals' understandings of cross-cultural interaction during end-of-life care.Sixty end-of-life care professionals were recruited from eleven care units in Sweden to take part in focus group interviews. These interviews were analyzed using qualitative content analysis.The health care professionals interviewed talked about cross-cultural interaction in end-of-life care as interaction that brings about uncertainty, stress and frustration even though they had limited experience of this type of interaction. The focus group discussions brought attention to four specific challenges that they expected to meet when they care for patients with migrant backgrounds since they took for granted that they would have an ethno-cultural background that is different to their own. These challenges had to do with communication barriers, 'unusual' emotional and pain expressions, the expectation that these patients' families would be 'different' and the anticipation that these patients and their families lack knowledge. At the core of the challenges in question is the idea that cross-cultural interaction means meeting "the unknown". In addition, the end-of-life care professionals interviewed talked about patients whose backgrounds they did not share in homogenizing terms. It is against this backdrop that they worried about their ability to provide end-of-life care that is individualized enough to meet the needs of these patients.The study suggests that end-of-life care professionals who regard cross-cultural interaction in this manner could face actual challenges when caring for patients whose backgrounds they regard as "the unknown" since they anticipate a variety

  10. Sticking to cellulose: exploiting Arabidopsis seed coat mucilage to understand cellulose biosynthesis and cell wall polysaccharide interactions.

    Science.gov (United States)

    Griffiths, Jonathan S; North, Helen M

    2017-05-01

    The cell wall defines the shape of cells and ultimately plant architecture. It provides mechanical resistance to osmotic pressure while still being malleable and allowing cells to grow and divide. These properties are determined by the different components of the wall and the interactions between them. The major components of the cell wall are the polysaccharides cellulose, hemicellulose and pectin. Cellulose biosynthesis has been extensively studied in Arabidopsis hypocotyls, and more recently in the mucilage-producing epidermal cells of the seed coat. The latter has emerged as an excellent system to study cellulose biosynthesis and the interactions between cellulose and other cell wall polymers. Here we review some of the major advances in our understanding of cellulose biosynthesis in the seed coat, and how mucilage has aided our understanding of the interactions between cellulose and other cell wall components required for wall cohesion. Recently, 10 genes involved in cellulose or hemicellulose biosynthesis in mucilage have been identified. These discoveries have helped to demonstrate that xylan side-chains on rhamnogalacturonan I act to link this pectin directly to cellulose. We also examine other factors that, either directly or indirectly, influence cellulose organization or crystallization in mucilage. © 2017 INRA. New Phytologist © 2017 New Phytologist Trust.

  11. Teachers' Beliefs about the Role of Interaction in Teaching Newtonian Mechanics and Its Influence on Students' Conceptual Understanding of Newton's Third Law

    Science.gov (United States)

    Jauhiainen, Johanna; Koponen, Ismo T.; Lavonen, Jari

    2006-01-01

    Students' conceptual understanding of Newton's third law has been the subject of numerous studies. These studies have often pointed out the importance of addressing the concept of interaction in teaching Newtonian mechanics. In this study, teachers were interviewed in order to examine how they understand interaction and use it in their…

  12. Celebrity Climate Contrarians: Understanding a keystone species in contemporary climate science-policy-public interactions

    Science.gov (United States)

    Boykoff, M. T.

    2012-12-01

    Since the 1980s, a keystone species called 'climate contrarians' has emerged and thrived. Through resistance to dominant interpretations of scientific evidence, and often outlier views on optimal responses to climate threats, contrarians have raised many meta-level questions: for instance, questions involve to what extent have their varied interventions been effective in terms of sparking a new and wise Copernican revolution; or do their amplified voices instead service entrenched carbon-based industry interests while they blend debates over 'climate change' with other culture wars? While the value of their influence has generated numerous debates, there is no doubt that climate contrarians have had significant influence on climate science, policy and public communities in ways that are larger than would be expected from their relative abundance in society. As such, a number of these actors have achieved 'celebrity status' in science-policy circles, and, at times, larger public spaces. This presentation focuses on how - particularly through amplified mass media attention to their movements - various outlier interventions have demonstrated themselves to be (often deliberately) detrimental to efforts that seek to enlarge rather than constrict the spectrum of possibility for mobilizing appropriate responses to ongoing climate challenges. Also, this work analyses the growth pathways of these charismatic megafauna through interview data and participant observations completed by the author at the 2011 Heartland Institute's Sixth International Conference on Climate Change. This provides detail on how outlier perspectives characterized as climate contrarians do work in these spaces under the guise of public intellectualism to achieve intended goals and objectives. The research undertaken and related in the presentation here seeks to better understand motivations that prop up these contrarian stances, such as possible ideological or evidentiary disagreement to the orthodox

  13. Enactive cinema paves way towards understanding complex real-time social interaction in neuroimaging experiments

    Directory of Open Access Journals (Sweden)

    Pia eTikka

    2012-11-01

    Full Text Available We outline general theoretical and practical implications of what we promote as enactive cinema for the neuroscientific study of online socio-emotional interaction. In a real-time functional magnetic resonance imaging (rt-fMRI setting, participants are immersed in cinematic experiences that simulate social situations. While viewing, their physiological reactions - including brain responses - are tracked, representing implicit and unconscious experiences of the on-going social situations. These reactions, in turn, are analysed in real-time and fed back to modify the cinematic sequences they are viewing while being scanned. Due to the engaging cinematic content, the proposed setting focuses on living-by in terms of shared psycho-physiological epiphenomena of experience rather than active coping in terms of goal-oriented motor actions. It constitutes a means to parametrically modify stimuli that depict social situations and their broader environmental contexts. As an alternative to studying the variation of brain responses as a function of a priori fixed stimuli, this method can be applied to survey the range of stimuli that evoke similar responses across participants at particular brain regions of interest.

  14. Enactive cinema paves way for understanding complex real-time social interaction in neuroimaging experiments.

    Science.gov (United States)

    Tikka, Pia; Väljamäe, Aleksander; de Borst, Aline W; Pugliese, Roberto; Ravaja, Niklas; Kaipainen, Mauri; Takala, Tapio

    2012-01-01

    We outline general theoretical and practical implications of what we promote as enactive cinema for the neuroscientific study of online socio-emotional interaction. In a real-time functional magnetic resonance imaging (rt-fMRI) setting, participants are immersed in cinematic experiences that simulate social situations. While viewing, their physiological reactions-including brain responses-are tracked, representing implicit and unconscious experiences of the on-going social situations. These reactions, in turn, are analyzed in real-time and fed back to modify the cinematic sequences they are viewing while being scanned. Due to the engaging cinematic content, the proposed setting focuses on living-by in terms of shared psycho-physiological epiphenomena of experience rather than active coping in terms of goal-oriented motor actions. It constitutes a means to parametrically modify stimuli that depict social situations and their broader environmental contexts. As an alternative to studying the variation of brain responses as a function of a priori fixed stimuli, this method can be applied to survey the range of stimuli that evoke similar responses across participants at particular brain regions of interest.

  15. Understanding trophic interactions of Orius spp. (Hemiptera: Anthocoridae) in lettuce crops by molecular methods.

    Science.gov (United States)

    Gomez-Polo, Priscila; Alomar, Oscar; Castañé, Cristina; Aznar-Fernández, Thaïs; Lundgren, Jonathan G; Piñol, Josep; Agustí, Nuria

    2016-02-01

    The aphid Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae) and the thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) are common pests in Mediterranean lettuce crops, where Orius spp. are common generalist predators. Predation by Orius spp. was studied in a lettuce plot by conventional polymerase chain reaction (PCR) and real-time PCR analyses using specific primers of both main pests. Also, high-throughput sequencing was used to have a wider approach of the diet of these predators in natural field conditions. Molecular analyses indicated a higher predation on N. ribisnigri in spring and on F. occidentalis in summer. Predation on alternative prey, like Collembola, was also found in both seasons. Real-time PCR was more sensitive than conventional PCR in showing the target trophic links, whereas high-throughput sequencing revealed predation on other natural enemies - intraguild predation (IGP), showing other trophic interactions of Orius majusculus within the studied ecosystem. This study gives important information about the trophic relationships present in Mediterranean lettuce crops in different periods of the year. The detected predation by Orius spp. on alternative prey, as well as on other natural enemies, should be further investigated to clarify whether it adds or detracts to the biological control of N. ribisnigri and F. occidentalis. © 2015 Society of Chemical Industry.

  16. Understanding the Flow Physics of Shock Boundary-Layer Interactions Using CFD and Numerical Analyses

    Science.gov (United States)

    Friedlander, David J.

    2013-01-01

    Computational fluid dynamic (CFD) analyses of the University of Michigan (UM) Shock/Boundary-Layer Interaction (SBLI) experiments were performed as an extension of the CFD SBLI Workshop held at the 48th AIAA Aerospace Sciences Meeting in 2010. In particular, the UM Mach 2.75 Glass Tunnel with a semi-spanning 7.75deg wedge was analyzed in attempts to explore key physics pertinent to SBLI's, including thermodynamic and viscous boundary conditions as well as turbulence modeling. Most of the analyses were 3D CFD simulations using the OVERFLOW flow solver, with additional quasi-1D simulations performed with an in house MATLAB code interfacing with the NIST REFPROP code to explore perfect verses non-ideal air. A fundamental exploration pertaining to the effects of particle image velocimetry (PIV) on post-processing data is also shown. Results from the CFD simulations showed an improvement in agreement with experimental data with key contributions including adding a laminar zone upstream of the wedge and the necessity of mimicking PIV particle lag for comparisons. Results from the quasi-1D simulation showed that there was little difference between perfect and non-ideal air for the configuration presented.

  17. [Understanding social interaction in children with autism spectrum disorders: does whole-body motion mean anything to them?].

    Science.gov (United States)

    Centelles, L; Assaiante, C; Etchegoyhen, K; Bouvard, M; Schmitz, C

    2012-06-01

    Autism spectrum disorders (ASD) are characterized by difficulties in social interaction and verbal and non verbal reciprocal communication. Face and gaze direction, which participate in non verbal communication, are described as atypical in ASD. Also body movements carry multiple social cues. Under certain circumstances, for instance when seeing two persons from far, they constitute the only support that allows the grasping of a social content. Here, we investigated the contribution of whole-body motion processing in social understanding. The aim of the study was to evaluate whether children with ASD make use of information carried by body motion to categorize dynamic visual scenes that portrayed social interactions. In 1973, Johansson devised a technique for studying the perception of biological motion that minimizes static form information from the stimulus, but retains motion information. In these point-light displays, the movement figure, such as a body, is represented by a small number of illuminated dots positioned to highlight the motion of the body parts. We used Johansson's model to explore the ability of children with ASD to understand social interactions based on human movement analysis. Three-second silent point-light displays were created by videotaping two actors. The two actors were either interacting together or moving side by side without interacting. A large range of social interaction displays were used to cover social scenes depicting social norms (conventional gestures and courteous attitudes), emotional situations (carrying positive or negative valences) and scenes from games (sports, dance, etc.). Children were asked to carefully watch the stimuli and to classify them according to the question "Are the two persons communicating or not?". Four sessions of 3 minutes were performed by each child. Children with ASD were compared with typically developing control children matched with either non verbal mental age or chronological age. Response and

  18. Understanding the interaction between wild fire and vegetation distribution within the NCAR CESM framework

    Science.gov (United States)

    Seo, H.; Kim, Y.; Kim, H. J.

    2017-12-01

    Every year wild fire brings about 400Mha of land burned therefore 2Pg of carbon emissions from the surface occur. In this way fire not only affects the carbon circulation but also has an effect on the terrestrial ecosystems. This study aims to understand role of fire on the geographic vegetation distribution and the terrestrial carbon balances within the NCAR CESM framework, specifically with the CLM-BGC and CLM-BGC-DV. Global climate data from Climate Research Unit (CRU)-National Centers for Environmental Prediction (NCEP) data ranging from 1901 to 2010 are used to drive the land models. First, by comparing fire-on and fire-off simulations with the CLM-BGC-DV, the fire impacts in dynamic vegetation are quantified by the fractional land areas of the different plant functional types. In addition, we examine how changes in vegetation distribution affect the total sum of the burned areas and the carbon balances. This study would provide the limits of and suggestions for the fire and dynamic vegetation modules of the CLM-BGC. AcknowledgementsThis work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2015R1C1A2A01054800) and by the Korea Meteorological Administration R&D Program under Grant KMIPA 2015-6180. This work was also supported by the Yonsei University Future-leading Research Initiative of 2015(2016-22-0061).

  19. A Transforming Electricity System: Understanding the Interactions Between Clean Energy Technologies, Markets, and Policies

    Science.gov (United States)

    Mooney, David

    The U.S. electricity system is currently undergoing a dramatic transformation. State-level renewable portfolio standards, abundant natural gas at low prices, and rapidly falling prices for wind and solar technologies are among the factors that have ushered in this transformation. With objective, rigorous, technology-neutral analysis, NREL aims to increase the understanding of energy policies, markets, resources, technologies, and infrastructure and their connections with economic, environmental, and security priorities. The results of these analyses are meant to inform R&D, policy, and investment decisions as energy-efficient and renewable energy technologies advance from concept to commercial application to market penetration. This talk will provide an overview of how NREL uses high-fidelity data, deep knowledge of energy technology cost and performance, and advanced models and tools to provide the information needed to ensure this transformation occurs economically, while maintaining system reliability. Examples will be explored and will include analysis of tax credit impacts on wind and solar deployment and power sector emissions, as well as analysis of power systems operations in the Eastern Interconnection under 30% wind and solar penetration scenarios. Invited speaker number 47185.

  20. Frameworks for Understanding the Nature of Interactions, Networking, and Community in a Social Networking Site for Academic Practice

    Directory of Open Access Journals (Sweden)

    Grainne Conole

    2011-03-01

    Full Text Available This paper describes a new social networking site, Cloudworks, which has been developed to enable discussion and sharing of learning and teaching ideas/designs and to promote reflective academic practice. The site aims to foster new forms of social and participatory practices (peer critiquing, sharing, user-generated content, aggregation, and personalisation within an educational context. One of the key challenges in the development of the site has been to understand the user interactions and the changing patterns of user behaviour as it evolves. The paper explores the extent to which four frameworks that have been used in researching networked learning contexts can provide insights into the patterns of user behaviour that we see in Cloudworks. The paper considers this within the current debate about the new types of interactions, networking, and community being observed as users adapt to and appropriate new technologies.

  1. Narratives with Robots: The Impact of Interaction Context and Individual Differences on Story Recall and Emotional Understanding

    Directory of Open Access Journals (Sweden)

    Iolanda Leite

    2017-07-01

    Full Text Available Role-play scenarios have been considered a successful learning space for children to develop their social and emotional abilities. In this paper, we investigate whether socially assistive robots in role-playing settings are as effective with small groups of children as they are with a single child and whether individual factors such as gender, grade level (first vs. second, perception of the robots (peer vs. adult, and empathy level (low vs. high play a role in these two interaction contexts. We conducted a three-week repeated exposure experiment where 40 children interacted with socially assistive robotic characters that acted out interactive stories around words that contribute to expanding children’s emotional vocabulary. Our results showed that although participants who interacted alone with the robots recalled the stories better than participants in the group condition, no significant differences were found in children’s emotional interpretation of the narratives. With regard to individual differences, we found that a single child setting appeared more appropriate to first graders than a group setting, empathy level is an important predictor for emotional understanding of the narratives, and children’s performance varies depending on their perception of the robots (peer vs. adult in the two conditions.

  2. Interaction between G Protein-Coupled Receptor 143 and Tyrosinase: Implications for Understanding Ocular Albinism Type 1.

    Science.gov (United States)

    De Filippo, Elisabetta; Schiedel, Anke C; Manga, Prashiela

    2017-02-01

    Developmental eye defects in X-linked ocular albinism type 1 are caused by G-protein coupled receptor 143 (GPR143) mutations. Mutations result in dysfunctional melanosome biogenesis and macromelanosome formation in pigment cells, including melanocytes and retinal pigment epithelium. GPR143, primarily expressed in pigment cells, localizes exclusively to endolysosomal and melanosomal membranes unlike most G protein-coupled receptors, which localize to the plasma membrane. There is some debate regarding GPR143 function and elucidating the role of this receptor may be instrumental for understanding neurogenesis during eye development and for devising therapies for ocular albinism type I. Many G protein-coupled receptors require association with other proteins to function. These G protein-coupled receptor-interacting proteins also facilitate fine-tuning of receptor activity and tissue specificity. We therefore investigated potential GPR143 interaction partners, with a focus on the melanogenic enzyme tyrosinase. GPR143 coimmunoprecipitated with tyrosinase, while confocal microscopy demonstrated colocalization of the proteins. Furthermore, tyrosinase localized to the plasma membrane when coexpressed with a GPR143 trafficking mutant. The physical interaction between the proteins was confirmed using fluorescence resonance energy transfer. This interaction may be required in order for GPR143 to function as a monitor of melanosome maturation. Identifying tyrosinase as a potential GPR143 binding protein opens new avenues for investigating the mechanisms that regulate pigmentation and neurogenesis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Understanding aerosol-cloud interactions in the development of orographic cumulus congestus during IPHEx

    Science.gov (United States)

    Barros, A. P.; Duan, Y.

    2017-12-01

    A new cloud parcel model (CPM) including activation, condensation, collision-coalescence, and lateral entrainment processes is presented here to investigate aerosol-cloud interactions (ACI) in cumulus development prior to rainfall onset. The CPM was employed along with ground based radar and surface aerosol measurements to predict the vertical structure of cloud formation at early stages and evaluated against airborne observations of cloud microphysics and thermodynamic conditions during the Integrated Precipitation and Hydrology Experiment (IPHEx) over the Southern Appalachian Mountains. Further, the CPM was applied to explore the space of ACI physical parameters controlling cumulus congestus growth not available from measurements, and to examine how variations in aerosol properties and microphysical processes influence the evolution and thermodynamic state of clouds over complex terrain via sensitivity analysis. Modeling results indicate that simulated spectra with a low value of condensation coefficient (0.01) are in good agreement with IPHEx aircraft observations around the same altitude. This is in contrast with high values reported in previous studies assuming adiabatic conditions. Entrainment is shown to govern the vertical development of clouds and the change of droplet numbers with height, and the sensitivity analysis suggests that there is a trade-off between entrainment strength and condensation process. Simulated CDNC also exhibits high sensitivity to variations in initial aerosol concentration at cloud base, but weak sensitivity to aerosol hygroscopicity. Exploratory multiple-parcel simulations capture realistic time-scales of vertical development of cumulus congestus (deeper clouds and faster droplet growth). These findings provide new insights into determinant factors of mid-day cumulus congestus formation that can explain a large fraction of warm season rainfall in mountainous regions.

  4. An interactive modelling tool for understanding hydrological processes in lowland catchments

    Science.gov (United States)

    Brauer, Claudia; Torfs, Paul; Uijlenhoet, Remko

    2016-04-01

    Recently, we developed the Wageningen Lowland Runoff Simulator (WALRUS), a rainfall-runoff model for catchments with shallow groundwater (Brauer et al., 2014ab). WALRUS explicitly simulates processes which are important in lowland catchments, such as feedbacks between saturated and unsaturated zone and between groundwater and surface water. WALRUS has a simple model structure and few parameters with physical connotations. Some default functions (which can be changed easily for research purposes) are implemented to facilitate application by practitioners and students. The effect of water management on hydrological variables can be simulated explicitly. The model description and applications are published in open access journals (Brauer et al, 2014). The open source code (provided as R package) and manual can be downloaded freely (www.github.com/ClaudiaBrauer/WALRUS). We organised a short course for Dutch water managers and consultants to become acquainted with WALRUS. We are now adapting this course as a stand-alone tutorial suitable for a varied, international audience. In addition, simple models can aid teachers to explain hydrological principles effectively. We used WALRUS to generate examples for simple interactive tools, which we will present at the EGU General Assembly. C.C. Brauer, A.J. Teuling, P.J.J.F. Torfs, R. Uijlenhoet (2014a): The Wageningen Lowland Runoff Simulator (WALRUS): a lumped rainfall-runoff model for catchments with shallow groundwater, Geosci. Model Dev., 7, 2313-2332. C.C. Brauer, P.J.J.F. Torfs, A.J. Teuling, R. Uijlenhoet (2014b): The Wageningen Lowland Runoff Simulator (WALRUS): application to the Hupsel Brook catchment and Cabauw polder, Hydrol. Earth Syst. Sci., 18, 4007-4028.

  5. Furthering our Understanding of Land Surface Interactions using SVAT modelling: Results from SimSphere's Validation

    Science.gov (United States)

    North, Matt; Petropoulos, George; Ireland, Gareth; Rendal, Daisy; Carlson, Toby

    2015-04-01

    With current predicted climate change, there is an increased requirement to gain knowledge on the terrestrial biosphere, for numerous agricultural, hydrological and meteorological applications. To this end, Soil Vegetation Atmospheric Transfer (SVAT) models are quickly becoming the preferred scientific tool to monitor, at fine temporal and spatial resolutions, detailed information on numerous parameters associated with Earth system interactions. Validation of any model is critical to assess its accuracy, generality and realism to distinctive ecosystems and subsequently acts as important step before its operational distribution. In this study, the SimSphere SVAT model has been validated to fifteen different sites of the FLUXNET network, where model performance was statistically evaluated by directly comparing the model predictions vs in situ data, for cloud free days with a high energy balance closure. Specific focus is given to the models ability to simulate parameters associated with the energy balance, namely Shortwave Incoming Solar Radiation (Rg), Net Radiation (Rnet), Latent Heat (LE), Sensible Heat (H), Air Temperature at 1.3m (Tair 1.3m) and Air temperature at 50m (Tair 50m). Comparisons were performed for a number distinctive ecosystem types and for 150 days in total using in-situ data from ground observational networks acquired from the year 2011 alone. Evaluation of the models' coherence to reality was evaluated on the basis of a series of statistical parameters including RMSD, R2, Scatter, Bias, MAE , NASH index, Slope and Intercept. Results showed good to very good agreement between predicted and observed datasets, particularly so for LE, H, Tair 1.3m and Tair 50m where mean error distribution values indicated excellent model performance. Due to the systematic underestimation, poorer simulation accuracies were exhibited for Rg and Rnet, yet all values reported are still analogous to other validatory studies of its kind. In overall, the model

  6. Tools to study pathogen-host interactions in bats.

    Science.gov (United States)

    Banerjee, Arinjay; Misra, Vikram; Schountz, Tony; Baker, Michelle L

    2018-03-15

    Bats are natural reservoirs for a variety of emerging viruses that cause significant disease in humans and domestic animals yet rarely cause clinical disease in bats. The co-evolutionary history of bats with viruses has been hypothesized to have shaped the bat-virus relationship, allowing both to exist in equilibrium. Progress in understanding bat-virus interactions and the isolation of bat-borne viruses has been accelerated in recent years by the development of susceptible bat cell lines. Viral sequences similar to severe acute respiratory syndrome corona virus (SARS-CoV) have been detected in bats, and filoviruses such as Marburg virus have been isolated from bats, providing definitive evidence for the role of bats as the natural host reservoir. Although viruses can be readily detected in bats using molecular approaches, virus isolation is far more challenging. One of the limitations in using traditional culture systems from non-reservoir species is that cell types and culture conditions may not be compatible for isolation of bat-borne viruses. There is, therefore, a need to develop additional bat cell lines that correspond to different cell types, including less represented cell types such as immune cells, and culture them under more physiologically relevant conditions to study virus host interactions and for virus isolation. In this review, we highlight the current progress in understanding bat-virus interactions in bat cell line systems and some of the challenges and limitations associated with cell lines. Future directions to address some of these challenges to better understand host-pathogen interactions in these intriguing mammals are also discussed, not only in relation to viruses but also other pathogens carried by bats including bacteria and fungi. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Affect recognition and the quality of mother-infant interaction: understanding parenting difficulties in mothers with schizophrenia.

    Science.gov (United States)

    Healy, Sarah J; Lewin, Jona; Butler, Stephen; Vaillancourt, Kyla; Seth-Smith, Fiona

    2016-02-01

    This study investigated the quality of mother-infant interaction and maternal ability to recognise adult affect in three study groups consisting of mothers with a diagnosis of schizophrenia, mothers with depression and healthy controls. Sixty-four mothers were recruited from a Mother and Baby Unit and local children's centres. A 5-min mother-infant interaction was coded on a number of caregiving variables. Affect recognition and discrimination abilities were tested via a series of computerised tasks. Group differences were found both in measures of affect recognition and in the mother-infant interaction. Mothers with schizophrenia showed consistent impairments across most of the parenting measures and all measures of affect recognition and discrimination. Mothers with depression fell between the mothers with schizophrenia and healthy controls on most measures. However, depressed women's parenting was not significantly poorer than controls on any of the measures, and only showed trends for differences with mothers with schizophrenia on a few measures. Regression analyses found impairments in affect recognition and a diagnosis of schizophrenia to predict the occurrence of odd or unusual speech in the mother-infant interaction. Results add to the growing body of knowledge on the mother-infant interaction in mothers with schizophrenia and mothers with depression compared to healthy controls, suggesting a need for parenting interventions aimed at mothers with these conditions. While affect recognition impairments were not found to fully explain differences in parenting among women with schizophrenia, further research is needed to understand the psychopathology of parenting disturbances within this clinical group.

  8. Model of competence: a conceptual framework for understanding the person-environment interaction for persons with motor disabilities.

    Science.gov (United States)

    Rousseau, Jacqueline; Potvin, Louise; Dutil, Elisabeth; Falta, Patricia

    2002-01-01

    The "Model of Competence" has been recently elaborated to help expand our understanding relating to a person's interaction with the environment. Specifically, it seeks to deal with the issues related to the home adaptation (the home layout and equipment) for a person living with motor disabilities. This theoretical model takes into account various characteristics of the person as well as of the environment, by re-grouping six concepts: person, environment, activity, role, competence and handicap situation. The "Model of Competence" is distinct because it includes: (1) both the human and the nonhuman dimension of the environment; (2) personal characteristics other than the strictly physical ones; (3) a clear identification of the interaction between the person and the environment; and (4) a means of operationalizing it via an assessment instrument. This model proposes an innovative approach to the person-environment relation in terms of personalizing accessibility, and thereby offers a new approach to understanding the concept of universal access. It has been developed for research and application, and addresses several disciplines.

  9. Understanding response patterns in dyadic conflict: An interactive approach combining self-construal and opponent's dominance-submissiveness.

    Science.gov (United States)

    Au, Al K C; Lam, Shui-Fong

    2017-04-01

    Previous works on the effect of self-construal in interpersonal behaviours tend to adopt a main effect approach. The present research proposes an interactive approach in understanding two response patterns in dyadic conflict by combining self-construal and the stance of the opponent. Independent self-construal was hypothesised to be associated with a self-centred pattern of conflict response, which is characterised by taking contending responses regardless of whether the stance of the opponent is dominant or submissive. Relational self-construal was hypothesised to be associated with a tuning-in pattern of conflict response, which is characterised by showing contending responses when the opponent is submissive but yielding responses when the opponent is dominant. With trait self-construal measured and opponent's stance manipulated, Study 1 provided initial support for the hypotheses. Study 2 showed a three-way interaction effect between trait self-construal, manipulated self-construal and the opponent's stance on actual conflict responses during discussion of a scenario. The effect of self-construal manipulation was only observed among people who were low in trait independent self-construal and average in trait relational self-construal. The results pinpoint the importance of considering personal and opponent factors simultaneously in understanding the dynamics of dyadic conflict processes. © 2015 International Union of Psychological Science.

  10. Gödel, Escher, and degree of handedness: differences in interhemispheric interaction predict differences in understanding self-reference.

    Science.gov (United States)

    Niebauer, Christopher Lee; Garvey, Kilian

    2004-01-01

    Ramachandran (1995) theorised that the left hemisphere (LH) is specialised for making a single and consistent interpretation of the self and the world, whereas the right hemisphere (RH) is responsible for monitoring anomalies in reference to these interpretations. If the anomalous information reaches a threshold, it interacts with the LH to update these interpretations or beliefs. Because mixed handers may have greater degrees of interhemispheric interaction compared to strong handers, they may have a lower threshold for updating beliefs. Two previous studies found this to be the case (Niebauer, Aselage, & Schutte, 2002a; Niebauer, Christman, & Reid, 2002b). Because monitoring one's beliefs may involve metacognitive processes, i.e., cognitions about cognitions, this model was extended to help explain individual differences in understanding self-referential concepts. In the first two studies, mixed-handed participants displayed a greater understanding of self-reference using a conceptual description of Gödel's Incompleteness Theorem. In a third study, mixed-handed participants displayed greater appreciation for self-referential works of M. C. Escher. Implications for a neuropsychological model of metacognition are discussed.

  11. Quantum interactive learning tutorial on the double-slit experiment to improve student understanding of quantum mechanics

    Science.gov (United States)

    Sayer, Ryan; Maries, Alexandru; Singh, Chandralekha

    2017-06-01

    Learning quantum mechanics is challenging, even for upper-level undergraduate and graduate students. Research-validated interactive tutorials that build on students' prior knowledge can be useful tools to enhance student learning. We have been investigating student difficulties with quantum mechanics pertaining to the double-slit experiment in various situations that appear to be counterintuitive and contradict classical notions of particles and waves. For example, if we send single electrons through the slits, they may behave as a "wave" in part of the experiment and as a "particle" in another part of the same experiment. Here we discuss the development and evaluation of a research-validated Quantum Interactive Learning Tutorial (QuILT) which makes use of an interactive simulation to improve student understanding of the double-slit experiment and strives to help students develop a good grasp of foundational issues in quantum mechanics. We discuss common student difficulties identified during the development and evaluation of the QuILT and analyze the data from the pretest and post test administered to the upper-level undergraduate and first-year physics graduate students before and after they worked on the QuILT to assess its effectiveness. These data suggest that on average, the QuILT was effective in helping students develop a more robust understanding of foundational concepts in quantum mechanics that defy classical intuition using the context of the double-slit experiment. Moreover, upper-level undergraduates outperformed physics graduate students on the post test. One possible reason for this difference in performance may be the level of student engagement with the QuILT due to the grade incentive. In the undergraduate course, the post test was graded for correctness while in the graduate course, it was only graded for completeness.

  12. Quantum interactive learning tutorial on the double-slit experiment to improve student understanding of quantum mechanics

    Directory of Open Access Journals (Sweden)

    Ryan Sayer

    2017-05-01

    Full Text Available Learning quantum mechanics is challenging, even for upper-level undergraduate and graduate students. Research-validated interactive tutorials that build on students’ prior knowledge can be useful tools to enhance student learning. We have been investigating student difficulties with quantum mechanics pertaining to the double-slit experiment in various situations that appear to be counterintuitive and contradict classical notions of particles and waves. For example, if we send single electrons through the slits, they may behave as a “wave” in part of the experiment and as a “particle” in another part of the same experiment. Here we discuss the development and evaluation of a research-validated Quantum Interactive Learning Tutorial (QuILT which makes use of an interactive simulation to improve student understanding of the double-slit experiment and strives to help students develop a good grasp of foundational issues in quantum mechanics. We discuss common student difficulties identified during the development and evaluation of the QuILT and analyze the data from the pretest and post test administered to the upper-level undergraduate and first-year physics graduate students before and after they worked on the QuILT to assess its effectiveness. These data suggest that on average, the QuILT was effective in helping students develop a more robust understanding of foundational concepts in quantum mechanics that defy classical intuition using the context of the double-slit experiment. Moreover, upper-level undergraduates outperformed physics graduate students on the post test. One possible reason for this difference in performance may be the level of student engagement with the QuILT due to the grade incentive. In the undergraduate course, the post test was graded for correctness while in the graduate course, it was only graded for completeness.

  13. Current Understanding of Physicochemical Mechanisms for Cell Membrane Penetration of Arginine-rich Cell Penetrating Peptides: Role of Glycosaminoglycan Interactions.

    Science.gov (United States)

    Takechi-Haraya, Yuki; Saito, Hiroyuki

    2018-01-01

    Arginine-rich cell penetrating peptides (CPPs) are very promising drug carriers to deliver membrane-impermeable pharmaceuticals, such as siRNA, bioactive peptides and proteins. CPPs directly penetrate into cells across cell membranes via a spontaneous energy-independent process, in which CPPs appear to interact with acidic lipids in the outer leaflet of the cell membrane. However, acidic lipids represent only 10 to 20% of the total membrane lipid content and in mammalian cell membranes they are predominantly located in the inner leaflet. Alternatively, CPPs favorably bind in a charge density- dependent manner to negatively charged, sulfated glycosaminoglycans (GAGs), such as heparan sulfate and chondroitin sulfate, which are abundant on the cell surface and are involved in many biological functions. We have recently demonstrated that the interaction of CPPs with sulfated GAGs plays a critical role in their direct cell membrane penetration: the favorable enthalpy contribution drives the high-affinity binding of arginine-rich CPPs to sulfated GAGs, initiating an efficient cell membrane penetration. The favorable enthalpy gain is presumably mainly derived from a unique property of the guanidino group of arginine residues forming multidentate hydrogen bonding with sulfate and carboxylate groups in GAGs. Such interactions can be accompanied with charge neutralization of arginine-rich CPPs, promoting their partition into cell membranes. This review summarizes the current understanding of the physicochemical mechanism for lipid membrane penetration of CPPs, and discusses the role of the GAG interactions on the cell membrane penetration of CPPs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. Dynamic interactions between dermal macrophages and Staphylococcus aureus.

    Science.gov (United States)

    Feuerstein, Reinhild; Kolter, Julia; Henneke, Philipp

    2017-01-01

    The dermis, a major reservoir of immune cells in immediate vicinity to the colonizing skin microflora, serves as an important site of host-pathogen interactions. Macrophages (Mϕ) are the most frequent resident immune cell type in the dermis. They protect the host from invasive infections by highly adapted bacteria, such as staphylococci via pattern recognition of bacterial effectors, phagocytosis, and recruitment of other myeloid cells from the blood. Already under homeostatic conditions, the dermal Mϕ population receives a dynamic input of monocytes invading from the bloodstream. This quantitative renewal is promoted further at the beginning of life, when prenatally seeded cells are rapidly replaced and in healing phases after injuries or infections. Here, we discuss the potential implications of the dynamic dermal Mϕ biology on the establishment and maintenance of immunity against Staphylococcus aureus, which can either be a harmless colonizer or an invasive pathogen. The understanding of the heterogeneity of the "mature" dermal Mϕ compartment driven both by the influx of differentiating monocytes and by a bone marrow-independent Mϕ persistence and expansion may help to explain failing immunity and immunopathology originating from the skin, the important interface between host and environment. © Society for Leukocyte Biology.

  15. Towards a New Understanding of the e-Business Strategic Process: The Rise of a Dynamic Interaction-Based Approach

    DEFF Research Database (Denmark)

    Ivang, Reimer

    2013-01-01

    -business strategic process adapt to changes in the planning environment and internal changes within the organization? E-business strategy, because of increased uncertainty and environmental complexity, must encourage interaction between key stakeholders that implement and use the e-business technology......In the early 1970s, strategic planning was introduced onto the corporate management scene and since then it has been a dominating conceptual frame for understanding and designing various strategies in the corporate world. Nearly a decade later, strategic planning has been used by various scholars...... to explain how companies could strategize in the field of ICT and e-business. Strategic information systems planning (SISP) is an example of this application of strategic planning in the field of e-business. The prominence of SISP within the corporate IS strategy literature has been dramatic, but today...

  16. Biomedical and veterinary science can increase our understanding of coral disease

    Science.gov (United States)

    Work, Thierry M.; Richardson, Laurie L.; Reynolds, T.L.; Willis, Bette L.

    2008-01-01

    A balanced approach to coral disease investigation is critical for understanding the global decline of corals. Such an approach should involve the proper use of biomedical concepts, tools, and terminology to address confusion and promote clarity in the coral disease literature. Investigating disease in corals should follow a logical series of steps including identification of disease, systematic morphologic descriptions of lesions at the gross and cellular levels, measurement of health indices, and experiments to understand disease pathogenesis and the complex interactions between host, pathogen, and the environment. This model for disease investigation is widely accepted in the medical, veterinary and invertebrate pathology disciplines. We present standard biomedical rationale behind the detection, description, and naming of diseases and offer examples of the application of Koch's postulates to elucidate the etiology of some infectious diseases. Basic epidemiologic concepts are introduced to help investigators think systematically about the cause(s) of complex diseases. A major goal of disease investigation in corals and other organisms is to gather data that will enable the establishment of standardized case definitions to distinguish among diseases. Concepts and facts amassed from empirical studies over the centuries by medical and veterinary pathologists have standardized disease investigation and are invaluable to coral researchers because of the robust comparisons they enable; examples of these are given throughout this paper. Arguments over whether coral diseases are caused by primary versus opportunistic pathogens reflect the lack of data available to prove or refute such hypotheses and emphasize the need for coral disease investigations that focus on: characterizing the normal microbiota and physiology of the healthy host; defining ecological interactions within the microbial community associated with the host; and investigating host immunity, host

  17. Understanding Oxygen Vacancy Formation, Interaction, Transport, and Strain in SOFC Components via Combined Thermodynamics and First Principles Calculations

    Science.gov (United States)

    Das, Tridip

    Understanding of the vacancy formation, interaction, increasing its concentration and diffusion, and controlling its chemical strain will advance the design of mixed ionic and electronic conductor (MIEC) materials via element doping and strain engineering. This is especially central to improve the performance of the solid oxide fuel cell (SOFC), an energy conversion device for sustainable future. The oxygen vacancy concentration grows exponentially with the temperature at dilute vacancy concentration but not at higher concentration, or even decreases due to oxygen vacancy interaction and vacancy ordered phase change. This limits the ionic conductivity. Using density functional theory (DFT), we provided fundamental understanding on how oxygen vacancy interaction originates in one of the typical MIEC, La1-xSrxFeO3-delta (LSF). The vacancy interaction is determined by the interplay of the charge state of multi-valence ion (Fe), aliovalent doping (La/Sr ratio), the crystal structure, and the oxygen vacancy concentration and/or nonstoichiometry (delta). It was found excess electrons left due to the formation of a neutral oxygen vacancy get distributed to Fe directly connected to the vacancy or to the second nearest neighboring Fe, based on crystal field splitting of Fe 3d orbital in different Fe-O polyhedral coordination. The progressively larger polaron size and anisotropic shape changes with increasing Sr-content resulted in increasing oxygen vacancy interactions, as indicated by an increase in the oxygen vacancy formation energy above a critical delta threshold. This was consistent with experimental results showing that Sr-rich LSF and highly oxygen deficient compositions are prone to oxygen-vacancy-ordering-induced phase transformations, while Sr-poor and oxygen-rich LSF compositions are not. Since oxygen vacancy induced phase transformations, cause a decrease in the mobile oxygen vacancy site fraction (X), both delta and X were predicted as a function of

  18. Interventions and Interactions: Understanding Coupled Human-Water Dynamics for Improved Water Resources Management in the Himalayas

    Science.gov (United States)

    Crootof, A.

    2017-12-01

    Understanding coupled human-water dynamics offers valuable insights to address fundamental water resources challenges posed by environmental change. With hydropower reshaping human-water interactions in mountain river basins, there is a need for a socio-hydrology framework—which examines two-way feedback loops between human and water systems—to more effectively manage water resources. This paper explores the cross-scalar interactions and feedback loops between human and water systems in river basins affected by run-of-the-river hydropower and highlights the utility of a socio-hydrology perspectives to enhance water management in the face of environmental change. In the Himalayas, the rapid expansion of run-of-the-river hydropower—which diverts streamflow for energy generation—is reconfiguring the availability, location, and timing of water resources. This technological intervention in the river basin not only alters hydrologic dyanmics but also shapes social outcomes. Using hydropower development in the highlands of Uttarakhand, India as a case study, I first illustrate how run-of-the-river projects transform human-water dynamics by reshaping the social and physical landscape of a river basin. Second, I emphasize how examining cross-scalar feedbacks among structural dynamics, social outcomes, and values and norms in this coupled human-water system can inform water management. Third, I present hydrological and social literature, raised separately, to indicate collaborative research needs and knowledge gaps for coupled human-water systems affected by run-of-the-river hydropower. The results underscore the need to understand coupled human-water dynamics to improve water resources management in the face of environmental change.

  19. Development of an Intelligent Digital Watershed to understand water-human interaction for a sustainable Agroeconomy in Midwest USA

    Science.gov (United States)

    Mishra, S. K.; Rapolu, U.; Ding, D.; Muste, M.; Bennett, D.; Schnoor, J. L.

    2011-12-01

    Human activity is intricately linked to the quality and quantity of water resources. Although many studies have examined water-human interaction, the complexity of such coupled systems is not well understood largely because of gaps in our knowledge of water-cycle processes which are heavily influenced by socio-economic drivers. Considerable research has been performed to develop an understanding of the impact of local land use decisions on field and catchment processes at an annual basis. Still less is known about the impact of economic and environmental outcomes on decision-making processes at the local and national level. Traditional geographic information management systems lack the ability to support the modeling and analysis of complex spatial processes. New frameworks are needed to track, query, and analyze the massive amounts of data generated by ensembles of simulations produced by multiple models that couple socioeconomic and natural system processes. On this context, we propose to develop an Intelligent Digital Watershed (IDW) which fuses emerging concepts of Digital Watershed (DW). DW is a comprehensive characterization of the eco hydrologic systems based on the best available digital data generated by measurements and simulations models. Prototype IDW in the form of a cyber infrastructure based engineered system will facilitate novel insights into human/environment interactions through multi-disciplinary research focused on watershed-related processes at multiple spatio-temporal scales. In ongoing effort, the prototype IDW is applied to Clear Creek watershed, an agricultural dominating catchment in Iowa, to understand water-human processes relevant to management decisions by farmers regarding agro ecosystems. This paper would also lay out the database design that stores metadata about simulation scenarios, scenario inputs and outputs, and connections among these elements- essentially the database. The paper describes the cyber infrastructure and

  20. Understanding the interactions of phosphonate-based flame-retarding additives with graphitic anode for lithium ion batteries

    International Nuclear Information System (INIS)

    Feng, Jinkui; Ma, Peng; Yang, Hanxi; Lu, Li

    2013-01-01

    Highlights: •Diethyl ethylphosphonate (DEEP) and dimethyl methylphosphonate are tested as flame retardants for lithium ion batteries. •The DMMP shows a destructive reaction with graphitic anode while DEEP shows a self-reduction mechanism. •DEEP is reported for the first time as flame-retardant additive for lithium ion batteries and demonstrates a much better compatibility with graphitic anode. -- Abstract: The compatibility with graphitic anode has been one key problem in developing flame-retarding additives for lithium ion batteries. To understand the interactions between flame-retarding additives and graphitic anode, two phosphonate esters (dimethyl methylphosphonate DMMP and diethyl ethylphosphonate DEEP) are selected and characterized as flame retardant addtives. DEEP is reported as a flame-retarding additive for the first time. Their interactions with graphite anode are characterized via current-static charge–discharge, ex-situ XRD, FE-SEM and AC impedance. The results reveal that the two phosphonate esters demonstrate different reaction mechanisms with graphitic anode, which result in different anode compatibility. These findings may be useful for designing better flame-retarding additives for lithium ion batteries

  1. Understanding the interaction between an obligate hyperparasitic bacterium, Pasteuria penetrans and its obligate plant-parasitic nematode host, Meloidogyne spp.

    Science.gov (United States)

    Davies, Keith G

    2009-01-01

    Pasteuria penetrans is an endospore-forming bacterium, which is a hyperparasite of root-knot nematodes Meloidogyne spp. that are economically important pests of a wide range of crops. The life cycle of the bacterium and nematode are described with emphasis on the bacterium's potential as a biocontrol agent. Two aspects that currently prohibit the commercial development of the bacterium as a biocontrol agent are the inability to culture it outside its host and its host specificity. Vegetative growth of the bacterium is possible in vitro; however, getting the vegetative stages of the bacterium to enter sporogenesis has been problematic. Insights from genomic survey sequences regarding the role of cation concentration and the phosphorylation of Spo0F have proved useful in inducing vegetative bacteria to sporulate. Similarly, genomic data have also proved useful in understanding the attachment of endospores to the cuticle of infective nematode juveniles, and a Velcro-like model of spore attachment is proposed that involves collagen-like fibres on the surface of the endospore interacting with mucins on the nematode cuticle. Ecological studies of the interactions between Daphnia and Pasteuria ramosa are examined and similarities are drawn between the co-evolution of virulence in the Daphnia system and that of plant-parasitic nematodes.

  2. Understanding an Elementary School Teachers' Journey of Using Technology in the Classroom from Sand Table to Interactive Whiteboard

    Directory of Open Access Journals (Sweden)

    Ali Ersoy

    2015-09-01

    Full Text Available The aim of this study is to understand an elementary teachers’ experiences about using interactive whiteboard (IWB in the classroom. Narrative inquiry were adopted to conduct the study. The data were collected through semi-structured interviews with the teacher and analysed through narrative analysis. In the study, two major stories emerged. The first story was about the characteristics and difficulties of being an innovative and transformative teacher. In the second story, the use of technology in the classroom were cited. Second story consisted of such sub-stories as changing student profiles, teaching-learning process, measurement and evaluation process, infrastructural adequacy, stakeholder interaction, facilitator role of the technology and challenges of using IWB in the classroom. In all these stories, the examples and advantages of effective use of IWB in the classroom were explained. We can have the following suggestions from the words of the classroom teacher who has been using various technological tools in his classroom for about 40 years, including 10-year IWB use: Teachers should be open-minded for innovation in the sense of professional development, consider the interests of students, reduce the prejudice about the use of technology, utilize the processes that increase and facilitate the learning.

  3. Retrospective use of PBPK modelling to understand a clinical drug-drug interaction between dextromethorphan and GSK1034702.

    Science.gov (United States)

    Hobbs, Michael J; Bloomer, Jackie; Dear, Gordon

    2017-08-01

    1. In a clinical trial, a strong drug-drug interaction (DDI) was observed between dextromethorphan (DM, the object or victim drug) and GSK1034702 (the precipitant or perpetrator drug), following single and repeat doses. This study determined the inhibition parameters of GSK1034702 in vitro and applied PBPK modelling approaches to simulate the clinical observations and provide mechanistic hypotheses to understand the DDI. 2. In vitro assays were conducted to determine the inhibition parameters of human CYP2D6 by GSK1034702. PBPK models were populated with the in vitro parameters and DDI simulations conducted and compared to the observed data from a clinical study with DM and GSK1034702. 3. GSK1034702 was a potent direct and metabolism-dependent inhibitor of human CYP2D6, with inhibition parameters of: IC 50  =   1.6 μM, K inact  = 3.7 h -1 and K I  = 0.8 μM. Incorporating these data into PBPK models predicted a DDI after repeat, but not single, 5 mg doses of GSK1034702. 4. The DDI observed with repeat administration of GSK1034702 (5 mg) can be attributed to metabolism-dependent inhibition of CYP2D6. Further, in vitro data were generated and several potential mechanisms proposed to explain the interaction observed following a single dose of GSK1034702.

  4. Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions.

    Science.gov (United States)

    Khayet, Mohamed; Fernández, Victoria

    2012-11-14

    Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals. Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall. The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions.

  5. The impact of deoxynivalenol on pigeon health : occurrence in feed, toxicokinetics and interaction with salmonellosis

    OpenAIRE

    Antonissen, Gunther; Haesendonck, Roel; Devreese, Mathias; Broekaert, Nathan; Verbrugghe, Elin; De Saeger, Sarah; Audenaert, Kris; Haesebrouck, Freddy; Pasmans, Frank; Ducatelle, Richard; Croubels, Siska; Martel, An

    2016-01-01

    Seed-based pigeon diets could be expected to result in exposure of pigeons to mycotoxins such as deoxynivalenol (DON). Ingestion of low to moderate contamination levels of DON may impair intestinal health, immune function and/or pathogen fitness, resulting in altered host-pathogen interactions and thus different outcome of infections. Here we demonstrate that DON was one of the most frequently detected mycotoxins in seed-based racing pigeons feed, contaminating 5 out of 10 samples (range 177-...

  6. Anaplasma phagocytophilum MSP4 and HSP70 Proteins Are Involved in Interactions with Host Cells during Pathogen Infection

    Directory of Open Access Journals (Sweden)

    Marinela Contreras

    2017-07-01

    Full Text Available Anaplasma phagocytophilum transmembrane and surface proteins play a role during infection and multiplication in host neutrophils and tick vector cells. Recently, A. phagocytophilum Major surface protein 4 (MSP4 and Heat shock protein 70 (HSP70 were shown to be localized on the bacterial membrane, with a possible role during pathogen infection in ticks. In this study, we hypothesized that A. phagocytophilum MSP4 and HSP70 have similar functions in tick-pathogen and host-pathogen interactions. To address this hypothesis, herein we characterized the role of these bacterial proteins in interaction and infection of vertebrate host cells. The results showed that A. phagocytophilum MSP4 and HSP70 are involved in host-pathogen interactions, with a role for HSP70 during pathogen infection. The analysis of the potential protective capacity of MSP4 and MSP4-HSP70 antigens in immunized sheep showed that MSP4-HSP70 was only partially protective against pathogen infection. This limited protection may be associated with several factors, including the recognition of non-protective epitopes by IgG in immunized lambs. Nevertheless, these antigens may be combined with other candidate protective antigens for the development of vaccines for the control of human and animal granulocytic anaplasmosis. Focusing on the characterization of host protective immune mechanisms and protein-protein interactions at the host-pathogen interface may lead to the discovery and design of new effective protective antigens.

  7. Ecosystem services capacity across heterogeneous forest types: understanding the interactions and suggesting pathways for sustaining multiple ecosystem services.

    Science.gov (United States)

    Alamgir, Mohammed; Turton, Stephen M; Macgregor, Colin J; Pert, Petina L

    2016-10-01

    As ecosystem services supply from tropical forests is declining due to deforestation and forest degradation, much effort is essential to sustain ecosystem services supply from tropical forested landscapes, because tropical forests provide the largest flow of multiple ecosystem services among the terrestrial ecosystems. In order to sustain multiple ecosystem services, understanding ecosystem services capacity across heterogeneous forest types and identifying certain ecosystem services that could be managed to leverage positive effects across the wider bundle of ecosystem services are required. We sampled three forest types, tropical rainforests, sclerophyll forests, and rehabilitated plantation forests, over an area of 32,000m(2) from Wet Tropics bioregion, Australia, aiming to compare supply and evaluate interactions and patterns of eight ecosystem services (global climate regulation, air quality regulation, erosion regulation, nutrient regulation, cyclone protection, habitat provision, energy provision, and timber provision). On average, multiple ecosystem services were highest in the rainforests, lowest in sclerophyll forests, and intermediate in rehabilitated plantation forests. However, a wide variation was apparent among the plots across the three forest types. Global climate regulation service had a synergistic impact on the supply of multiple ecosystem services, while nutrient regulation service was found to have a trade-off impact. Considering multiple ecosystem services, most of the rehabilitated plantation forest plots shared the same ordination space with rainforest plots in the ordination analysis, indicating that rehabilitated plantation forests may supply certain ecosystem services nearly equivalent to rainforests. Two synergy groups and one trade-off group were identified. Apart from conserving rainforests and sclerophyll forests, our findings suggest two additional integrated pathways to sustain the supply of multiple ecosystem services from a

  8. Plant-pathogen interactions: what microarray tells about it?

    Science.gov (United States)

    Lodha, T D; Basak, J

    2012-01-01

    Plant defense responses are mediated by elementary regulatory proteins that affect expression of thousands of genes. Over the last decade, microarray technology has played a key role in deciphering the underlying networks of gene regulation in plants that lead to a wide variety of defence responses. Microarray is an important tool to quantify and profile the expression of thousands of genes simultaneously, with two main aims: (1) gene discovery and (2) global expression profiling. Several microarray technologies are currently in use; most include a glass slide platform with spotted cDNA or oligonucleotides. Till date, microarray technology has been used in the identification of regulatory genes, end-point defence genes, to understand the signal transduction processes underlying disease resistance and its intimate links to other physiological pathways. Microarray technology can be used for in-depth, simultaneous profiling of host/pathogen genes as the disease progresses from infection to resistance/susceptibility at different developmental stages of the host, which can be done in different environments, for clearer understanding of the processes involved. A thorough knowledge of plant disease resistance using successful combination of microarray and other high throughput techniques, as well as biochemical, genetic, and cell biological experiments is needed for practical application to secure and stabilize yield of many crop plants. This review starts with a brief introduction to microarray technology, followed by the basics of plant-pathogen interaction, the use of DNA microarrays over the last decade to unravel the mysteries of plant-pathogen interaction, and ends with the future prospects of this technology.

  9. NOD1CARD Might Be Using Multiple Interfaces for RIP2-Mediated CARD-CARD Interaction: Insights from Molecular Dynamics Simulation.

    Directory of Open Access Journals (Sweden)

    Jitendra Maharana

    Full Text Available The nucleotide-binding and oligomerization domain (NOD-containing protein 1 (NOD1 plays the pivotal role in host-pathogen interface of innate immunity and triggers immune signalling pathways for the maturation and release of pro-inflammatory cytokines. Upon the recognition of iE-DAP, NOD1 self-oligomerizes in an ATP-dependent fashion and interacts with adaptor molecule receptor-interacting protein 2 (RIP2 for the propagation of innate immune signalling and initiation of pro-inflammatory immune responses. This interaction (mediated by NOD1 and RIP2 helps in transmitting the downstream signals for the activation of NF-κB signalling pathway, and has been arbitrated by respective caspase-recruitment domains (CARDs. The so-called CARD-CARD interaction still remained contradictory due to inconsistent results. Henceforth, to understand the mode and the nature of the interaction, structural bioinformatics approaches were employed. MD simulation of modelled 1:1 heterodimeric complexes revealed that the type-Ia interface of NOD1CARD and the type-Ib interface of RIP2CARD might be the suitable interfaces for the said interaction. Moreover, we perceived three dynamically stable heterotrimeric complexes with an NOD1:RIP2 ratio of 1:2 (two numbers and 2:1. Out of which, in the first trimeric complex, a type-I NOD1-RIP2 heterodimer was found interacting with an RIP2CARD using their type-IIa and IIIa interfaces. However, in the second and third heterotrimer, we observed type-I homodimers of NOD1 and RIP2 CARDs were interacting individually with RIP2CARD and NOD1CARD (in type-II and type-III interface, respectively. Overall, this study provides structural and dynamic insights into the NOD1-RIP2 oligomer formation, which will be crucial in understanding the molecular basis of NOD1-mediated CARD-CARD interaction in higher and lower eukaryotes.

  10. A Cognitive Model of How Interactive Multimedia Authoring Facilitates Conceptual Understanding of Object-Oriented Programming in Novices

    Science.gov (United States)

    Yuen, Timothy; Liu, Min

    2011-01-01

    This paper presents a cognitive model of how interactive multimedia authoring (IMA) affect novices' cognition in object-oriented programming. This model was generated through an empirical study of first year computer science students at the university level being engaged in interactive multimedia authoring of a role-playing game. Clinical…

  11. Nitric oxide production by necrotrophic pathogen Macrophomina phaseolina and the host plant in charcoal rot disease of jute: complexity of the interplay between necrotroph-host plant interactions.

    Directory of Open Access Journals (Sweden)

    Tuhin Subhra Sarkar

    Full Text Available M. phaseolina, a global devastating necrotrophic fungal pathogen causes charcoal rot disease in more than 500 host plants. With the aim of understanding the plant-necrotrophic pathogen interaction associated with charcoal rot disease of jute, biochemical approach was attempted to study cellular nitric oxide production under diseased condition. This is the first report on M. phaseolina infection in Corchorus capsularis (jute plants which resulted in elevated nitric oxide, reactive nitrogen species and S nitrosothiols production in infected tissues. Time dependent nitric oxide production was also assessed with 4-Amino-5-Methylamino-2',7'-Difluorofluorescein Diacetate using single leaf experiment both in presence of M. phaseolina and xylanases obtained from fungal secretome. Cellular redox status and redox active enzymes were also assessed during plant fungal interaction. Interestingly, M. phaseolina was found to produce nitric oxide which was detected in vitro inside the mycelium and in the surrounding medium. Addition of mammalian nitric oxide synthase inhibitor could block the nitric oxide production in M. phaseolina. Bioinformatics analysis revealed nitric oxide synthase like sequence with conserved amino acid sequences in M. phaseolina genome sequence. In conclusion, the production of nitric oxide and reactive nitrogen species may have important physiological significance in necrotrophic host pathogen interaction.

  12. Understanding Trends in Catalytic Activity: The Effect of Adsorbate-Adsorbate Interactions for CO Oxidation Over Transition Metals

    DEFF Research Database (Denmark)

    Grabow, Lars; Larsen, Britt Hvolbæk; Nørskov, Jens Kehlet

    2010-01-01

    Using high temperature CO oxidation as the example, trends in the reactivity of transition metals are discussed on the basis of density functional theory (DFT) calculations. Volcano type relations between the catalytic rate and adsorption energies of important intermediates are introduced...... and the effect of adsorbate-adsorbate interaction on the trends is discussed. We find that adsorbate-adsorbate interactions significantly increase the activity of strong binding metals (left side of the volcano) but the interactions do not change the relative activity of different metals and have a very small...... influence on the position of the top of the volcano, that is, on which metal is the best catalyst....

  13. Toward understanding social cues and signals in human?robot interaction: effects of robot gaze and proxemic behavior

    OpenAIRE

    Fiore, Stephen M.; Wiltshire, Travis J.; Lobato, Emilio J. C.; Jentsch, Florian G.; Huang, Wesley H.; Axelrod, Benjamin

    2013-01-01

    As robots are increasingly deployed in settings requiring social interaction, research is needed to examine the social signals perceived by humans when robots display certain social cues. In this paper, we report a study designed to examine how humans interpret social cues exhibited by robots. We first provide a brief overview of perspectives from social cognition in humans and how these processes are applicable to human–robot interaction (HRI). We then discuss the need to examine the relatio...

  14. Phenotypic interactions between tree hosts and invasive forest pathogens in the light of globalization and climate change.

    Science.gov (United States)

    Stenlid, Jan; Oliva, Jonàs

    2016-12-05

    Invasive pathogens can cause considerable damage to forest ecosystems. Lack of coevolution is generally thought to enable invasive pathogens to bypass the defence and/or recognition systems in the host. Although mostly true, this argument fails to predict intermittent outcomes in space and time, underlining the need to include the roles of the environment and the phenotype in host-pathogen interactions when predicting disease impacts. We emphasize the need to consider host-tree imbalances from a phenotypic perspective, considering the lack of coevolutionary and evolutionary history with the pathogen and the environment, respectively. We describe how phenotypic plasticity and plastic responses to environmental shifts may become maladaptive when hosts are faced with novel pathogens. The lack of host-pathogen and environmental coevolution are aligned with two global processes currently driving forest damage: globalization and climate change, respectively. We suggest that globalization and climate change act synergistically, increasing the chances of both genotypic and phenotypic imbalances. Short moves on the same continent are more likely to be in balance than if the move is from another part of the world. We use Gremmeniella abietina outbreaks in Sweden to exemplify how host-pathogen phenotypic interactions can help to predict the impacts of specific invasive and emergent diseases.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'. © 2016 The Author(s).

  15. Results from Pion-Carbon Interactions Measured by NA61/SHINE for Improved Understanding of Extensive Air Showers

    CERN Document Server

    Herve, Alexander

    2015-07-21

    The interpretation of extensive air shower measurements, produced by ultra-high energy cosmic rays, relies on the correct modeling of the hadron-air interactions that occur during the shower development. The majority of hadronic particles are produced at equivalent beam energies below the TeV range. NA61/SHINE is a fixed target experiment using secondary beams produced at CERN at the SPS. Hadron-hadron interactions have been recorded at beam momenta between 13 and 350 GeV/c with a wide-acceptance spectrometer. In this contribution we present measurements of the spectra of charged pions and the $\\rho^0$ production in pion-carbon interactions, which are essential for modeling of air showers.

  16. Quantum Interactive Learning Tutorial on the Double-Slit Experiment to Improve Student Understanding of Quantum Mechanics

    Science.gov (United States)

    Sayer, Ryan; Maries, Alexandru; Singh, Chandralekha

    2017-01-01

    Learning quantum mechanics is challenging, even for upper-level undergraduate and graduate students. Research-validated interactive tutorials that build on students' prior knowledge can be useful tools to enhance student learning. We have been investigating student difficulties with quantum mechanics pertaining to the double-slit experiment in…

  17. Understanding plant cell-wall remodelling during the symbiotic interaction between Tuber melanosporum and Corylus avellana using a carbohydrate microarray.

    Science.gov (United States)

    Sillo, Fabiano; Fangel, Jonatan U; Henrissat, Bernard; Faccio, Antonella; Bonfante, Paola; Martin, Francis; Willats, William G T; Balestrini, Raffaella

    2016-08-01

    A combined approach, using a carbohydrate microarray as a support for genomic data, has revealed subtle plant cell-wall remodelling during Tuber melanosporum and Corylus avellana interaction. Cell walls are involved, to a great extent, in mediating plant-microbe interactions. An important feature of these interactions concerns changes in the cell-wall composition during interaction with other organisms. In ectomycorrhizae, plant and fungal cell walls come into direct contact, and represent the interface between the two partners. However, very little information is available on the re-arrangement that could occur within the plant and fungal cell walls during ectomycorrhizal symbiosis. Taking advantage of the Comprehensive Microarray Polymer Profiling (CoMPP) technology, the current study has had the aim of monitoring the changes that take place in the plant cell wall in Corylus avellana roots during colonization by the ascomycetous ectomycorrhizal fungus T. melanosporum. Additionally, genes encoding putative plant cell-wall degrading enzymes (PCWDEs) have been identified in the T. melanosporum genome, and RT-qPCRs have been performed to verify the expression of selected genes in fully developed C. avellana/T. melanosporum ectomycorrhizae. A localized degradation of pectin seems to occur during fungal colonization, in agreement with the growth of the ectomycorrhizal fungus through the middle lamella and with the fungal gene expression of genes acting on these polysaccharides.

  18. Toward understanding social cues and signals in human–robot interaction: effects of robot gaze and proxemic behavior

    Science.gov (United States)

    Fiore, Stephen M.; Wiltshire, Travis J.; Lobato, Emilio J. C.; Jentsch, Florian G.; Huang, Wesley H.; Axelrod, Benjamin

    2013-01-01

    As robots are increasingly deployed in settings requiring social interaction, research is needed to examine the social signals perceived by humans when robots display certain social cues. In this paper, we report a study designed to examine how humans interpret social cues exhibited by robots. We first provide a brief overview of perspectives from social cognition in humans and how these processes are applicable to human–robot interaction (HRI). We then discuss the need to examine the relationship between social cues and signals as a function of the degree to which a robot is perceived as a socially present agent. We describe an experiment in which social cues were manipulated on an iRobot AvaTM mobile robotics platform in a hallway navigation scenario. Cues associated with the robot’s proxemic behavior were found to significantly affect participant perceptions of the robot’s social presence and emotional state while cues associated with the robot’s gaze behavior were not found to be significant. Further, regardless of the proxemic behavior, participants attributed more social presence and emotional states to the robot over repeated interactions than when they first interacted with it. Generally, these results indicate the importance for HRI research to consider how social cues expressed by a robot can differentially affect perceptions of the robot’s mental states and intentions. The discussion focuses on implications for the design of robotic systems and future directions for research on the relationship between social cues and signals. PMID:24348434

  19. Toward understanding social cues and signals in human-robot interaction: effects of robot gaze and proxemic behavior.

    Science.gov (United States)

    Fiore, Stephen M; Wiltshire, Travis J; Lobato, Emilio J C; Jentsch, Florian G; Huang, Wesley H; Axelrod, Benjamin

    2013-01-01

    As robots are increasingly deployed in settings requiring social interaction, research is needed to examine the social signals perceived by humans when robots display certain social cues. In this paper, we report a study designed to examine how humans interpret social cues exhibited by robots. We first provide a brief overview of perspectives from social cognition in humans and how these processes are applicable to human-robot interaction (HRI). We then discuss the need to examine the relationship between social cues and signals as a function of the degree to which a robot is perceived as a socially present agent. We describe an experiment in which social cues were manipulated on an iRobot Ava(TM) mobile robotics platform in a hallway navigation scenario. Cues associated with the robot's proxemic behavior were found to significantly affect participant perceptions of the robot's social presence and emotional state while cues associated with the robot's gaze behavior were not found to be significant. Further, regardless of the proxemic behavior, participants attributed more social presence and emotional states to the robot over repeated interactions than when they first interacted with it. Generally, these results indicate the importance for HRI research to consider how social cues expressed by a robot can differentially affect perceptions of the robot's mental states and intentions. The discussion focuses on implications for the design of robotic systems and future directions for research on the relationship between social cues and signals.

  20. Towards understanding social cues and signals in human-robot interaction: Effects of robot gaze and proxemic behavior

    Directory of Open Access Journals (Sweden)

    Stephen M. Fiore

    2013-11-01

    Full Text Available As robots are increasingly deployed in settings requiring social interaction, research is needed to examine the social signals perceived by humans when robots display certain social cues. In this paper, we report a study designed to examine how humans interpret social cues exhibited by robots. We first provide a brief overview of perspectives from social cognition in humans and how these processes are applicable to human-robot interaction (HRI. We then discuss the need to examine the relationship between social cues and signals as a function of the degree to which a robot is perceived as a socially present agent. We describe an experiment in which social cues were manipulated on an iRobot Ava™ Mobile Robotics Platform in a hallway navigation scenario. Cues associated with the robot’s proxemic behavior were found to significantly affect participant perceptions of the robot’s social presence and emotional state while cues associated with the robot’s gaze behavior were not found to be significant. Further, regardless of the proxemic behavior, participants attributed more social presence and emotional states to the robot over repeated interactions than when they first interacted with it. Generally, these results indicate the importance for HRI research to consider how social cues expressed by a robot can differentially affect perceptions of the robot’s mental states and intentions. The discussion focuses on implications for the design of robotic systems and future directions for research on the relationship between social cues and signals.

  1. Understanding the Effect of Response Rate and Class Size Interaction on Students Evaluation of Teaching in a Higher Education

    Science.gov (United States)

    Al Kuwaiti, Ahmed; AlQuraan, Mahmoud; Subbarayalu, Arun Vijay

    2016-01-01

    Objective: This study aims to investigate the interaction between response rate and class size and its effects on students' evaluation of instructors and the courses offered at a higher education Institution in Saudi Arabia. Study Design: A retrospective study design was chosen. Methods: One thousand four hundred and forty four different courses…

  2. Increasing Parent and Caregiver Understanding of the Power of Positive Interactions in Promoting Prosocial Behaviour in Young Children.

    Science.gov (United States)

    Thompson, Pamela

    The goal of the project presented in the practicum was to help parents develop competencies in interacting with their children in ways which foster self esteem and cooperative behavior. The objectives of the practicum included, first, increasing parents' knowledge of: (1) the factors leading to high self esteem and cooperative behavior; (2) the…

  3. Understanding the Importance of “Symbolic Interaction Stigma:” How Expectations about the Reactions of Others Adds to the Burden of Mental illness Stigma

    Science.gov (United States)

    Link, Bruce G.; Wells, Jennifer; Phelan, Jo C.; Yang, Lawrence

    2017-01-01

    Objective Important components of stigma include imagining what others might think of a stigmatized status, anticipating what might transpire in an interaction with others, and rehearsing what one might do if something untoward occurs. These imagined relations are here called “symbolic interaction stigma” and can be impactful even if the internalization of negative stereotypes fails to occur. Concepts and measures that capture symbolic interaction stigma are introduced and a preliminary assessment of their impact provided. Methods Four self-report measures of symbolic interaction stigma (perceived devaluation discrimination, anticipation of rejection, stigma consciousness and concern with staying in) were developed or adapted and administered to a sample of individuals who have experienced mental illness (N=65). Regression analyses examined whether forms of symbolic interaction stigma were associated with withdrawal, self-esteem and isolation from relatives independent of measures of internalization of stigma and rejection experiences. Results As evidenced by scores on four distinct measures symbolic interaction stigma was relatively common in the sample, somewhat more common than the internalization of stigma. Additionally, measures of symbolic interaction stigma were significantly associated with withdrawal, self-esteem and isolation from relatives even when a measure of the internalization of stigma was statistically controlled. Conclusions and Implications for Practice The study suggests the potential importance of considering symbolic interaction forms of stigma in understanding and addressing stigma and its consequences. Being aware of symbolic interaction stigma could be useful in enhancing rehabilitation goals if an approach to counteracting the negative effects of these aspects of stigma can be developed. PMID:26075528

  4. Understanding the importance of "symbolic interaction stigma": How expectations about the reactions of others adds to the burden of mental illness stigma.

    Science.gov (United States)

    Link, Bruce G; Wells, Jennifer; Phelan, Jo C; Yang, Lawrence

    2015-06-01

    Important components of stigma include imagining what others might think of a stigmatized status, anticipating what might transpire in an interaction with others, and rehearsing what one might do if something untoward occurs. These imagined relations are here called symbolic interaction stigma and can have an impact even if the internalization of negative stereotypes fails to occur. Concepts and measures that capture symbolic interaction stigma are introduced, and a preliminary assessment of their impact is provided. Four self-report measures of symbolic interaction stigma (perceived devaluation discrimination, anticipation of rejection, stigma consciousness, and concern with staying in) were developed or adapted and administered to a sample of individuals who have experienced mental illness (N = 65). Regression analyses examined whether forms of symbolic interaction stigma were associated with withdrawal, self-esteem, and isolation from relatives independent of measures of internalization of stigma and rejection experiences. As evidenced by scores on 4 distinct measures, symbolic interaction stigma was relatively common in the sample, somewhat more common than the internalization of stigma. In addition, measures of symbolic interaction stigma were significantly associated with withdrawal, self-esteem, and isolation from relatives even when a measure of the internalization of stigma was statistically controlled. The study suggests the potential importance of considering symbolic interaction forms of stigma in understanding and addressing stigma and its consequences. Being aware of symbolic interaction stigma could be useful in enhancing rehabilitation goals if an approach to counteracting the negative effects of these aspects of stigma can be developed. (c) 2015 APA, all rights reserved).

  5. Impact of Interactive Multimedia Module with Pedagogical Agents on Students' Understanding and Motivation in the Learning of Electrochemistry

    Science.gov (United States)

    Osman, Kamisah; Lee, Tien Tien

    2014-01-01

    The Electrochemistry topic is found to be difficult to learn due to its abstract concepts involving macroscopic, microscopic, and symbolic representation levels. Studies have shown that animation and simulation using information and communication technology (ICT) can help students to visualize and hence enhance their understanding in learning…

  6. Bipartite networks improve understanding of effects of waterbody size and angling method on angler–fish interactions

    Science.gov (United States)

    Chizinski, Christopher J.; Martin, Dustin R.; Shizuka, Daizaburo; Pope, Kevin L.

    2018-01-01

    Networks used to study interactions could provide insights to fisheries. We compiled data from 27 297 interviews of anglers across waterbodies that ranged in size from 1 to 12 113 ha. Catch rates of fish species among anglers grouped by species targeted generally differed between angling methods (bank or boat). We constructed angler–catch bipartite networks (angling method specific) between anglers and fish and measured several network metrics. There was considerable variation in networks among waterbodies, with multiple metrics influenced by waterbody size. Number of species-targeting angler groups and number of fish species caught increased with increasing waterbody size. Mean number of links for species-targeting angler groups and fish species caught also increased with waterbody size. Connectance (realized proportion of possible links) of angler–catch interaction networks decreased slower for boat anglers than for bank anglers with increasing waterbody size. Network specialization (deviation of number of interactions from expected) was not significantly related to waterbody size or angling methods. Application of bipartite networks in fishery science requires careful interpretation of outputs, especially considering the numerous confounding factors prevalent in recreational fisheries.

  7. Water absorption in PEEK and PEI matrices. Contribution to the understanding of water-polar group interactions

    Science.gov (United States)

    Courvoisier, E.; Bicaba, Y.; Colin, X.

    2016-05-01

    The water absorption in two aromatic linear polymers (PEEK and PEI) was studied between 10% and 90% RH at 30, 50 and 70°C. It was found that these polymers display classical Henry and Fick's behaviors. Moreover, they have very close values of equilibrium water concentration C∞ and water diffusivity D presumably because their respective polar groups establish molecular interactions of the same nature with water. This assumption was checked from a literature compilation of values of C∞ and D for a large variety of linear and tridimensional polymers containing a single type of polar group. It was then evidenced that almost all types of carbonyl group (in particular, those belonging to imides, amides and ketones) have the same molar contribution to water absorption, except those belonging to esters which are much less hydrophilic. Furthermore, hydroxyl and sulfone groups are much more hydrophilic than carbonyl groups so that their molar contribution is located on another master curve. On this basis, semi-empirical structure/water transport property relationships were proposed. It was found that C∞ increases exponentially with the concentration of polar groups (presumably because water is doubly bonded), but also with the intensity of their molecular interactions with water. In contrast, D is inversely proportional to C∞, which means that polar group-water interactions slow down the rate of water diffusion.

  8. Proceedings of the 19. IAHR international symposium on ice : using new technology to understand water-ice interaction

    International Nuclear Information System (INIS)

    Jasek, M.; Andrishak, R.; Siddiqui, A.

    2008-01-01

    This conference provided a venue for scientists, engineers and researchers an opportunity to expand their knowledge of water-ice interactions with reference to water resources, river and coastal hydraulics, risk analysis, energy and the environment. The the theme of new technology falls into 3 basic groups, notably measurement and instrumentation; remote sensing; and numerical simulation. The thermal regime of rivers was discussed along with ice mechanics, ice hydraulics, ice structures and modelling ice phenomena. The titles of the sessions were: river ice, glaciers and climate change; freeze-up processes on rivers and oceans; river ice-structure interactions; numerical simulations in ice engineering; river-ice break-up and ice jam formation; ice measurement; Grasse River ice evaluation; evaluation of structural ice control alternatives; remote sensing; hydropower and dam decommissioning; mechanical behaviour of river ice, ice covered flow and thermal modelling; mathematical and computer model formulations for ice friction and sea ice; ice bergs and ice navigation; ice crushing processes; sea ice and shore/structure interactions; ice properties, testing and physical modelling; ice actions on compliant structures; oil spills in ice; desalination, ice thickness and climate change; and, sea ice ridges. The conference featured 123 presentations, of which 20 have been catalogued separately for inclusion in this database. refs., tabs., figs

  9. Proteomics and its applications to aquaculture in China: infection, immunity, and interaction of aquaculture hosts with pathogens.

    Science.gov (United States)

    Peng, Xuan-Xian

    2013-01-01

    China is the largest fishery producer worldwide in term of its aquaculture output, and plays leading and decisive roles in international aquaculture development. To improve aquaculture output further and promote aquaculture business development, infectious diseases and immunity of fishes and other aquaculture species must be studied. In this regard, aquaculture proteomics has been widely carried out in China to get a better understanding of aquaculture host immunity and microbial pathogenesis as well as host-pathogen interactions, and to identify novel disease targets and vaccine candidates for therapeutic interventions. These proteomics studies include development of novel methods, assays, and advanced concepts in order to characterize proteomics mechanisms of host innate immune defense and microbial pathogenesis. This review article summarizes some recently published technical approaches and their applications to aquaculture proteomics with an emphasis on the responses of aquaculture animals to bacteria, viruses, and other aqua-environmental stresses, and development of broadly cross-protective vaccine candidates. The reviewed articles are those that have been published in international peer reviewed journals. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Dual transcriptomics of virus-host interactions: comparing two Pacific oyster families presenting contrasted susceptibility to ostreid herpesvirus 1.

    Science.gov (United States)

    Segarra, Amélie; Mauduit, Florian; Faury, Nicole; Trancart, Suzanne; Dégremont, Lionel; Tourbiez, Delphine; Haffner, Philippe; Barbosa-Solomieu, Valérie; Pépin, Jean-François; Travers, Marie-Agnès; Renault, Tristan

    2014-07-09

    Massive mortality outbreaks affecting Pacific oyster (Crassostrea gigas) spat in various countries have been associated with the detection of a herpesvirus called ostreid herpesvirus type 1 (OsHV-1). However, few studies have been performed to understand and follow viral gene expression, as it has been done in vertebrate herpesviruses. In this work, experimental infection trials of C. gigas spat with OsHV-1 were conducted in order to test the susceptibility of several bi-parental oyster families to this virus and to analyze host-pathogen interactions using in vivo transcriptomic approaches. The divergent response of these oyster families in terms of mortality confirmed that susceptibility to OsHV-1 infection has a significant genetic component. Two families with contrasted survival rates were selected. A total of 39 viral genes and five host genes were monitored by real-time PCR. Initial results provided information on (i) the virus cycle of OsHV-1 based on the kinetics of viral DNA replication and transcription and (ii) host defense mechanisms against the virus. In the two selected families, the detected amounts of viral DNA and RNA were significantly different. This result suggests that Pacific oysters are genetically diverse in terms of their susceptibility to OsHV-1 infection. This contrasted susceptibility was associated with dissimilar host gene expression profiles. Moreover, the present study showed a positive correlation between viral DNA amounts and the level of expression of selected oyster genes.

  11. Host-Brucella interactions and the Brucella genome as tools for subunit antigen discovery and immunization against brucellosis

    Science.gov (United States)

    Gomez, Gabriel; Adams, Leslie G.; Rice-Ficht, Allison; Ficht, Thomas A.

    2013-01-01

    Vaccination is the most important approach to counteract infectious diseases. Thus, the development of new and improved vaccines for existing, emerging, and re-emerging diseases is an area of great interest to the scientific community and general public. Traditional approaches to subunit antigen discovery and vaccine development lack consideration for the critical aspects of public safety and activation of relevant protective host immunity. The availability of genomic sequences for pathogenic Brucella spp. and their hosts have led to development of systems-wide analytical tools that have provided a better understanding of host and pathogen physiology while also beginning to unravel the intricacies at the host-pathogen interface. Advances in pathogen biology, host immunology, and host-agent interactions have the potential to serve as a platform for the design and implementation of better-targeted antigen discovery approaches. With emphasis on Brucella spp., we probe the biological aspects of host and pathogen that merit consideration in the targeted design of subunit antigen discovery and vaccine development. PMID:23720712

  12. Understanding human – bat interactions in NSW, Australia: improving risk communication for prevention of Australian bat lyssavirus

    OpenAIRE

    Quinn, Emma K; Massey, Peter D; Cox-Witton, Keren; Paterson, Beverley J; Eastwood, Keith; Durrheim, David N

    2014-01-01

    Background Australian bat lyssavirus (ABLV) infects a number of flying fox and insectivorous bats species in Australia. Human infection with ABLV is inevitably fatal unless prior vaccination and/or post-exposure treatment (PET) is given. Despite ongoing public health messaging about the risks associated with bat contact, surveillance data have revealed a four-fold increase in the number of people receiving PET for bat exposure in NSW between 2007 and 2011. Our study aimed to better understand...

  13. An understanding about the process of communicative interactions in Joint Planning Groups among professors of the physics degree course based on Theory of Communicative Acts

    Directory of Open Access Journals (Sweden)

    João Ricardo Neves da Silva

    2016-04-01

    Full Text Available This article presents the results of a study that aims to understand the possibilities from the accession of professors who teach specific topics of physics and physics teaching in the teachers formation degree in a Joint Planning Group about the relations among their disciplines. The study was built from the establishment and monitoring of a group of professors who met regularly during a year to plan their courses in the degree in physics together. Based on the theoretical perspective of the Theory of Communicative Acts, by Jürgen Habermas, the analysis aimed to understand the planning process through the use of language as a means of inter-subjective interaction and intention of understanding through the use of valid claims. The possibilities presented enable conceptualize the elements of a Joint Planning Group from the perspective of joint construction of concepts and practices, actions coordinating and theming of the practice in a an environment that enables communicative acts.

  14. Micropatterned co-culture of hepatocyte spheroids layered on non-parenchymal cells to understand heterotypic cellular interactions

    International Nuclear Information System (INIS)

    Otsuka, Hidenori; Sasaki, Kohei; Okimura, Saya; Nagamura, Masako; Nakasone, Yuichi

    2013-01-01

    Microfabrication and micropatterning techniques in tissue engineering offer great potential for creating and controlling cellular microenvironments including cell–matrix interactions, soluble stimuli and cell–cell interactions. Here, we present a novel approach to generate layered patterning of hepatocyte spheroids on micropatterned non-parenchymal feeder cells using microfabricated poly(ethylene glycol) (PEG) hydrogels. Micropatterned PEG-hydrogel-treated substrates with two-dimensional arrays of gelatin circular domains (ϕ = 100 μm) were prepared by photolithographic method. Only on the critical structure of PEG hydrogel with perfect protein rejection, hepatocytes were co-cultured with non-parenchymal cells to be led to enhanced hepatocyte functions. Then, we investigated the mechanism of the functional enhancement in co-culture with respect to the contributions of soluble factors and direct cell–cell interactions. In particular, to elucidate the influence of soluble factors on hepatocyte function, hepatocyte spheroids underlaid with fibroblasts (NIH/3T3 mouse fibroblasts) or endothelial cells (BAECs: bovine aortic endothelial cells) were compared with physically separated co-culture of hepatocyte monospheroids with NIH3T3 or BAEC using trans-well culture systems. Our results suggested that direct heterotypic cell-to-cell contact and soluble factors, both of these between hepatocytes and fibroblasts, significantly enhanced hepatocyte functions. In contrast, direct heterotypic cell-to-cell contact between hepatocytes and endothelial cells only contributed to enhance hepatocyte functions. This patterning technique can be a useful experimental tool for applications in basic science, drug screening and tissue engineering, as well as in the design of artificial liver devices. (paper)

  15. The architecture of visual narrative comprehension: the interaction of narrative structure and page layout in understanding comics.

    Science.gov (United States)

    Cohn, Neil

    2014-01-01

    How do people make sense of the sequential images in visual narratives like comics? A growing literature of recent research has suggested that this comprehension involves the interaction of multiple systems: The creation of meaning across sequential images relies on a "narrative grammar" that packages conceptual information into categorical roles organized in hierarchic constituents. These images are encapsulated into panels arranged in the layout of a physical page. Finally, how panels frame information can impact both the narrative structure and page layout. Altogether, these systems operate in parallel to construct the Gestalt whole of comprehension of this visual language found in comics.

  16. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    This paper considers the impact of visual art and performance on robotics and human-computer interaction and outlines a research project that combines puppetry and live performance with robotics. Kinesics—communication through movement—is the foundation of many theatre and performance traditions ...

  17. Toward Understanding Phage:Host Interactions in the Rumen; Complete Genome Sequences of Lytic Phages Infecting Rumen Bacteria

    Directory of Open Access Journals (Sweden)

    Rosalind A. Gilbert

    2017-12-01

    Full Text Available The rumen is known to harbor dense populations of bacteriophages (phages predicted to be capable of infecting a diverse range of rumen bacteria. While bacterial genome sequencing projects are revealing the presence of phages which can integrate their DNA into the genome of their host to form stable, lysogenic associations, little is known of the genetics of phages which utilize lytic replication. These phages infect and replicate within the host, culminating in host lysis, and the release of progeny phage particles. While lytic phages for rumen bacteria have been previously isolated, their genomes have remained largely uncharacterized. Here we report the first complete genome sequences of lytic phage isolates specifically infecting three genera of rumen bacteria: Bacteroides, Ruminococcus, and Streptococcus. All phages were classified within the viral order Caudovirales and include two phage morphotypes, representative of the Siphoviridae and Podoviridae families. The phage genomes displayed modular organization and conserved viral genes were identified which enabled further classification and determination of closest phage relatives. Co-examination of bacterial host genomes led to the identification of several genes responsible for modulating phage:host interactions, including CRISPR/Cas elements and restriction-modification phage defense systems. These findings provide new genetic information and insights into how lytic phages may interact with bacteria of the rumen microbiome.

  18. Toward a better understanding of the interaction between TGF-β family members and their ALK receptors

    KAUST Repository

    Romano, Valentina; Raimondo, Domenico; Calvanese, Luisa; D’ Auria, Gabriella; Tramontano, Anna; Falcigno, Lucia

    2012-01-01

    Transforming growth factor-beta (TGF-β) proteins are a family of structurally related extracellular proteins that trigger their signaling functions through interaction with the extracellular domains of their cognate serine/threonine kinase receptors. The specificity of TGF-β/receptor binding is complex and gives rise to multiple functional roles. Additionally, it is not completely understood at the atomic level. Here, we use the most reliable computational methods currently available to study systems involving activin-like kinase (ALK) receptors ALK4 and ALK7 and their multiple TGF-β ligands. We built models for all these proteins and their complexes for which experimental structures are not available. By analyzing the surfaces of interaction in six different TGF-β/ALK complexes we could infer which are the structural distinctive features of the ligand-receptor binding mode. Furthermore, this study allowed us to rationalize why binding of the growth factors GDF3 and Nodal to the ALK4 receptor requires the Cripto co-factor, whilst binding to the ALK7 receptor does not. © Springer-Verlag 2012.

  19. Understanding spatial and temporal patterning of astrocyte calcium transients via interactions between network transport and extracellular diffusion

    Science.gov (United States)

    Shtrahman, E.; Maruyama, D.; Olariu, E.; Fink, C. G.; Zochowski, M.

    2017-02-01

    Astrocytes form interconnected networks in the brain and communicate via calcium signaling. We investigate how modes of coupling between astrocytes influence the spatio-temporal patterns of calcium signaling within astrocyte networks and specifically how these network interactions promote coordination within this group of cells. To investigate these complex phenomena, we study reduced cultured networks of astrocytes and neurons. We image the spatial temporal patterns of astrocyte calcium activity and quantify how perturbing the coupling between astrocytes influences astrocyte activity patterns. To gain insight into the pattern formation observed in these cultured networks, we compare the experimentally observed calcium activity patterns to the patterns produced by a reduced computational model, where we represent astrocytes as simple units that integrate input through two mechanisms: gap junction coupling (network transport) and chemical release (extracellular diffusion). We examine the activity patterns in the simulated astrocyte network and their dependence upon these two coupling mechanisms. We find that gap junctions and extracellular chemical release interact in astrocyte networks to modulate the spatiotemporal patterns of their calcium dynamics. We show agreement between the computational and experimental findings, which suggests that the complex global patterns can be understood as a result of simple local coupling mechanisms.

  20. Toward a better understanding of the interaction between TGF-β family members and their ALK receptors

    KAUST Repository

    Romano, Valentina

    2012-02-22

    Transforming growth factor-beta (TGF-β) proteins are a family of structurally related extracellular proteins that trigger their signaling functions through interaction with the extracellular domains of their cognate serine/threonine kinase receptors. The specificity of TGF-β/receptor binding is complex and gives rise to multiple functional roles. Additionally, it is not completely understood at the atomic level. Here, we use the most reliable computational methods currently available to study systems involving activin-like kinase (ALK) receptors ALK4 and ALK7 and their multiple TGF-β ligands. We built models for all these proteins and their complexes for which experimental structures are not available. By analyzing the surfaces of interaction in six different TGF-β/ALK complexes we could infer which are the structural distinctive features of the ligand-receptor binding mode. Furthermore, this study allowed us to rationalize why binding of the growth factors GDF3 and Nodal to the ALK4 receptor requires the Cripto co-factor, whilst binding to the ALK7 receptor does not. © Springer-Verlag 2012.

  1. Collaborative Research: Atmospheric Pressure Plasma-Biomaterial Surface Interactions - Bridging Understanding of APP Sources to Rational Modification of Biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Graves, David Barry [Univ. of California, Berkeley, CA (United States)

    2017-11-24

    The overriding objective of this work is to bridge the gap between understanding of atmospheric pressure plasma (APP) sources and predictive chemical modifications of biomolecules. A key aspect of this problem is to understand what oxidizing species are created in water adjacent to APP jets that would ultimately affect aqueous biomolecules. We report the production of highly oxidative species in solutions exposed to a self-pulsed corona discharge in air. We examine how the properties of the target solution (pH, conductivity) and the discharge power affect the discharge stability and the production of H2O2. Indigo carmine, a common organic dye, is used as an indicator of oxidative strength and in particular, hydroxyl radical (OH•) production. The observed rate of indigo oxidation in contact with the discharge far exceeds that predicted from reactions based on concentrations of species measured in the bulk solution. The generation of H2O2 and the oxidation of indigo carmine indicate a high concentration of highly oxidizing species such as OH• at the plasma-liquid interface. These results indicate that reactions at the air plasma-liquid interface play a dominant role in species oxidation during direct non-equilibrium atmospheric pressure plasma (NE-APP) treatment.

  2. Towards a better understanding of the interaction between bed roughness and flow hydraulics in small eroded channels

    Science.gov (United States)

    Giménez, Rafael; Zubieta, Elena; Campo-Bescós, Miguel A.; Casalí, Javier

    2016-04-01

    Rills eroding cohesive materials are hydraulically different from rivers or large channels. Unlike rivers, rills are small, shallow flow stream with frequently a relatively steep slope gradient. Besides, rills evolve morphologically over much shorter timescales due to active bed erosion. This leads to a strong interaction between the channel flow and bed roughness. This interaction gives rise to a reconfiguration of the bed geometry generated by the important erosive action of the flow. This new shape is characterized by a typical alternance between concavities (pools) and more or less flat reaches (steps). The new rill geometry affects, in turn, the behaviour of the flow that is why we talk about interaction or feedback. In addition, the greatest energy dissipation occurs in the pools -mainly due to the action of hydraulic jumps- which, in turn, lead to an increase in the pool size. We hypothesize there is a regular spacing of step-pools units and that, both the frequency and the depth of the pools will be strongly conditioned by the discharge and the general rill slope. The determination of that periodicity (if any) would be an important contribution for concentrated flow erosion modelling of small channels. That is because the majority of erosion models are based on formulations which assume that a rill has a flat bed, only affected by micro-roughness. For instance, equations like Manning's - widely used in river and large channel hydraulics -, if a constant value of roughness is assumed, would be inappropriate in erosion rills since, as explained above, the roughness is not constant. The objectives of this work are then: (i) to investigate the geometry of erosion rills aiming at determining if there is a spatial arrangement of the macro roughness of their beds; and (ii) to establish (semi)-empirical models of prediction of this periodicity, mainly based on topographic parameters. Rills were generated in an agricultural field in a homogeneous hillslope (with no

  3. A model for understanding diagnostic imaging referrals and complex interaction processes within the bigger picture of a healthcare system

    International Nuclear Information System (INIS)

    Makanjee, Chandra R.; Bergh, Anne-Marie; Hoffmann, Willem A.

    2014-01-01

    Using experiences from the South African public healthcare system with limited resources, this review proposes a model that captures a holistic perspective of diagnostic imaging services embedded in a network of negotiated decision-making processes. Professional interdependency and interprofessional collaboration, cooperation and coordination are built around the central notion of integration in order to achieve a seamless transition through the continuum of various types of services needed to come to a diagnosis. Health-system role players interact with patients who enter the system from the perspective of their life-world. The distribution of diagnostic imaging services – within one setting or at multiple levels of care – demonstrates how fragments of information are filtered, interpreted and transformed at each point of care. The proposed model could contribute to alignment towards a common goal: services providing holistic quality of care within and beyond a complex healthcare system

  4. Conceptual shifts needed to understand the dynamic interactions of genes, environment, epigenetics, social processes, and behavioral choices.

    Science.gov (United States)

    Jackson, Fatimah L C; Niculescu, Mihai D; Jackson, Robert T

    2013-10-01

    Social and behavioral research in public health is often intimately tied to profound, but frequently neglected, biological influences from underlying genetic, environmental, and epigenetic events. The dynamic interplay between the life, social, and behavioral sciences often remains underappreciated and underutilized in addressing complex diseases and disorders and in developing effective remediation strategies. Using a case-study format, we present examples as to how the inclusion of genetic, environmental, and epigenetic data can augment social and behavioral health research by expanding the parameters of such studies, adding specificity to phenotypic assessments, and providing additional internal control in comparative studies. We highlight the important roles of gene-environment interactions and epigenetics as sources of phenotypic change and as a bridge between the life and social and behavioral sciences in the development of robust interdisciplinary analyses.

  5. Studies of Sociosexual Interactions in Rats in an Externally Valid Procedure: Are They Relevant for Understanding Human Sexual Behavior?

    Directory of Open Access Journals (Sweden)

    Xi Chu

    2016-09-01

    Full Text Available When a prolonged observation of groups of rats in a seminatural environment is used as testing procedure, different behavioral patterns are shown compared with what observed in a pair housed in a small cage. Males and females copulate simultaneously, they show a promiscuously and random copulatory pattern. Females remain completely receptive from the first lordosis displayed in the period of behavioral estrus until the last. There is no reduction in paracopulatory behaviors and no increase in rejections towards the end of estrus. Female paracopulatory behavior and receptivity change in a most abrupt way at both initiation and termination of behavioral estrus. It appears that, in the seminatural environment, males copulate in bouts, and males do not pursue the females unless they are fully receptive. Non-sexual, social behavior including affiliative and nonaffiliative interaction among rats is rather unrelated to sexual activities in both sex.

  6. Volume transmission and receptor-receptor interactions in heteroreceptor complexes: understanding the role of new concepts for brain communication

    Directory of Open Access Journals (Sweden)

    Kjell Fuxe

    2016-01-01

    Full Text Available The discovery of the central monoamine neurons not only demonstrated novel types of brain stem neurons forming global terminal networks all over the brain and the spinal cord, but also to a novel type of communication called volume transmission. It is a major mode of communication in the central nervous system that takes places in the extracellular fluid and the cerebral spinal fluid through diffusion and flow of molecules, like neurotransmitters and extracellular vesicles. The integration of synaptic and volume transmission takes place through allosteric receptor-receptor interactions in heteroreceptor complexes. These heterocomplexes represent major integrator centres in the plasma membrane and their protomers act as moonlighting proteins undergoing dynamic changes and their structure and function. In fact, we propose that the molecular bases of learning and memory can be based on the reorganization of multiples homo and heteroreceptor complexes into novel assembles in the post-junctional membranes of synapses.

  7. Symbolic interactionism: a perspective for understanding parent-nurse interactions following the birth of a child with Down syndrome.

    Science.gov (United States)

    van Riper, M; Pridham, K; Ryff, C

    1992-01-01

    The birth of a child with Down syndrome is a challenge to parental and societal expectations. Feelings of shock, sadness, confusion, denial, fear, anger, guilt, and helplessness may be evoked. In this paper, the impact of stigma on individuals with Down syndrome and their families will be reviewed to clarify why interactions between parents and others need to be explored. Next, the central concepts important to the symbolic interactionist perspective will be reviewed. Then, qualitative data from an ongoing study of 90 parents of children with Down syndrome (ages 3 months to 18 years) will be presented to illustrate how symbolic interactionism can be applied to the to care of children with Down syndrome and their families. Finally, implications for nurses working with families that include a child with Down syndrome will be addressed.

  8. A dynamic ecosystem process model for understanding interactions between permafrost thawing and vegetation responses in the arctic

    Science.gov (United States)

    Xu, C.; Travis, B. J.; Fisher, R. A.; Wilson, C. J.; McDowell, N.

    2010-12-01

    The arctic is expected to play an important role in the Earth’s future climate due to the large carbon stocks that are stored in permafrost and peatlands, a substantial proportion of which may be released to the atmosphere due to permafrost thawing. There may be positive feedbacks of permafrost thawing on plant growth by releasing stored nitrogen and increasing rooting depth; however, vegetation response to other changing variables such as CO2 and temperature can also modify soil hydrology and energy fluxes, leading to either positive or negative feedbacks on permafrost thawing. Disentangling the interactions between permafrost thawing and vegetation growth is critical for assessing the potential role of arctic regions on current and future global carbon cycling. We have developed a mechanistic, regional, and spatially explicit dynamic ecosystem process model through the integration of a 3-D soil hydrology and biogeochemistry model (Arctic Hydrology, ARCHY) and a dynamic vegetation model (Ecosystem Demography, ED), to quantify the importance of plant-permafrost interactions to soil and plant carbon storage. This model integrates important processes including photosynthesis, transpiration, respiration, 3-D competition for light, 3-D soil hydrology, energy fluxes (ice melting in the soil and solar radiation interception by canopy), nitrogen cycles (microbial decomposition, nitrogen transportation in soil, passive and active nitrogen uptake by plants), species migration, and drought-related mortality. A sensitivity analysis has been implemented to assess the importance of the hydrological cycle, the nitrogen cycle and energy fluxes in regulating the above and below-ground carbon cycles in arctic regions. Our model can fill an important gap between field and global land surface models for assessing plot and regional level hypotheses in the context of global climate.

  9. Nonlocal electrostatics in ionic liquids: The key to an understanding of the screening decay length and screened interactions

    Science.gov (United States)

    Kjellander, Roland

    2016-09-01

    Screened electrostatic interactions in ionic liquids are investigated by means of exact statistical mechanical analysis combined with physical arguments that enhance the transparency and conceptual accessibility of the analysis and results. The constituent ions and immersed particles in the liquid can have arbitrary shapes and any internal charge distributions. The decay of the screened electrostatic potential and the free energy of interaction in ionic liquids can be exponentially damped oscillatory (like in molten simple salts) as well as plain exponential and long-ranged (like in dilute electrolyte solutions). Both behaviors are in agreement with the exact statistical mechanical analysis and reasons for their appearances are investigated. Exact but surprisingly simple expressions for the decay parameter κ of the screened electrostatics are obtained, which replace the classical expression for the Debye-Hückel parameter κDH (the reciprocal Debye length). The expressions are applicable both for cases with plain exponential and oscillatory behaviors. The key importance of nonlocal electrostatics is thereby demonstrated explicitly. Dielectric properties of ionic liquids and other electrolytes are investigated, in particular the static dielectric function ɛ ˜ ( k ) and some effective relative permittivities ( Er eff and Er ∗ ), which take roles that the dielectric constant ɛr has for polar liquids consisting of electroneutral molecules. The dielectric constant in the latter case, which is the limit of ɛ ˜ ( k ) when the wave number k → 0, can be expressed solely in terms of dipolar features of the molecules. In contrast to this, the effective dielectric permittivities of ionic liquids have contributions also from quadrupolar, octupolar, and higher multipolar features of the constituent ions. The "dielectric constant" of electrolytes does not exist since ɛ ˜ ( k ) → ∞ when k → 0, a well-known effect of perfect screening. The effective relative

  10. Comparing human-Salmonella with plant-Salmonella protein-protein interaction predictions

    Directory of Open Access Journals (Sweden)

    Sylvia eSchleker

    2015-01-01

    Full Text Available Salmonellosis is the most frequent food-borne disease world-wide and can be transmitted to humans by a variety of routes, especially via animal and plant products. Salmonella bacteria are believed to use not only animal and human but also plant hosts despite their evolutionary distance. This raises the question if Salmonella employs similar mechanisms in infection of these diverse hosts. Given that most of our understanding comes from its interaction with human hosts, we investigate here to what degree knowledge of Salmonella-human interactions can be transferred to the Salmonella-plant system. Reviewed are recent publications on analysis and prediction of Salmonella-host interactomes. Putative protein-protein interactions (PPIs between Salmonella and its human and Arabidopsis hosts were retrieved utilizing purely interolog-based approaches in which predictions were inferred based on available sequence and domain information of known PPIs, and machine learning approaches that integrate a larger set of useful information from different sources. Transfer learning is an especially suitable machine learning technique to predict plant host targets from the knowledge of human host targets. A comparison of the prediction results with transcriptomic data shows a clear overlap between the host proteins predicted to be targeted by PPIs and their gene ontology enrichment in both host species and regulation of gene expression. In particular, the cellular processes Salmonella interferes with in plants and humans are catabolic processes. The details of how these processes are targeted, however, are quite different between the two organisms, as expected based on their evolutionary and habitat differences. Possible implications of this observation on evolution of host-pathogen communication are discussed.

  11. Variable host-pathogen compatibility in Mycobacterium tuberculosis.

    NARCIS (Netherlands)

    Gagneux, Sebastien; DeRiemer, Kathryn; Van, Tran; Kato-Maeda, Midori; Jong, Bouke C de; Narayanan, Sujatha; Nicol, Mark; Niemann, Stefan; Kremer, Kristin; Gutierrez, M Cristina; Hilty, Markus; Hopewell, Philip C; Small, Peter M

    2006-01-01

    Mycobacterium tuberculosis remains a major cause of morbidity and mortality worldwide. Studies have reported human pathogens to have geographically structured population genetics, some of which have been linked to ancient human migrations. However, no study has addressed the potential evolutionary

  12. Host pathogen relations: exploring animal models for fungal pathogens.

    Science.gov (United States)

    Harwood, Catherine G; Rao, Reeta P

    2014-06-30

    Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.

  13. Host Pathogen Relations: Exploring Animal Models for Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    Catherine G. Harwood

    2014-06-01

    Full Text Available Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.

  14. Understanding the interactions between Social Capital, climate change, and community resilience in Gulf of Mexico coastal counties

    Science.gov (United States)

    Young, C.; Blomberg, B.; Kolker, A.; Nguyen, U.; Page, C. M.; Sherchan, S. P.; Tobias, V. D.; Wu, H.

    2017-12-01

    Coastal communities in the Gulf of Mexico are facing new and complex challenges as their physical environment is altered by climate warming and sea level rise. To effectively prepare for environmental changes, coastal communities must build resilience in both physical structures and social structures. One measure of social structure resilience is how much social capital a community possesses. Social capital is defined as the connections among individuals which result in networks with shared norms, values and understandings that facilitate cooperation within or among groups. Social capital exists in three levels; bonding, bridging and linking. Bonding social capital is a measure of the strength of relationships amongst members of a network who are similar in some form. Bridging social capital is a measure of relationships amongst people who are dissimilar in some way, such as age, education, or race/ethnicity. Finally Linking social capital measures the extent to which individuals build relationships with institutions and individuals who have relative power over them (e.g local government, educational institutions). Using census and American Community Survey data, we calculated a Social Capital index value for bonding, bridging and linking for 60 Gulf of Mexico coastal counties for the years 2000, and 2010 to 2015. To investigate the impact of social capital on community resilience we coupled social capital index values with physical datasets of land-use/land cover, sea level change, climate, elevation and surface water quality for each coastal county in each year. Preliminary results indicate that in Gulf of Mexico coastal counties, increased bonding social capital results in decreased population change. In addition, we observed a multi-year time lag in the effect of increased bridging social capital on population stability, potentially suggesting key linkages between the physical and social environment in this complex coupled-natural human system. This

  15. Contribution of MS-based proteomics to the understanding of Herpes Simplex Virus type 1 interaction with host cells

    Directory of Open Access Journals (Sweden)

    Enrique eSantamaría

    2012-03-01

    Full Text Available Like other DNA viruses, Herpes Simplex Virus type 1 (HSV-1 replicates and proliferates in host cells continuously modulating the host molecular environment. Following a sophisticated temporal expression pattern, HSV-1 encodes at least 89 multifunctional proteins that interplay with and modify the host cell proteome. During the last decade, advances in mass spectrometry applications coupled to the development of proteomic separation methods have allowed to partially monitor the impact of HSV-1 infection in human cells. In this review, we discuss the current use of different proteome fractionation strategies to define HSV-1 targets on two major application areas: i viral protein interactomics to decipher viral protein interactions in host cells and ii differential quantitative proteomics to analyse the virally induced changes in the cellular proteome. Moreover, we will also discuss the potential application of high throughput proteomic approaches to study global proteome dynamics and also post-translational modifications in HSV-1-infected cells, what will greatly improved our molecular knowledge of HSV-1 infection.

  16. Unraveling the in vitro secretome of the phytopathogen Botrytis cinerea to understand the interaction with its hosts

    Directory of Open Access Journals (Sweden)

    Raquel eGonzález-Fernández

    2015-10-01

    Full Text Available Botrytis cinerea is a necrotrophic fungus with high adaptability to different environments and hosts. It secretes a large number of extracellular proteins, which favor plant tissue penetration and colonization, thus contributing to virulence. Secretomics is a proteomics sub-discipline which study the secreted proteins and their secretion mechanisms, so-called secretome. By using proteomics as experimental approach, many secreted proteins by B. cinerea have been identified from in vitro experiments, and belonging to different functional categories: i cell wall-degrading enzymes such as pectinesterases, and endo-polygalacturonases; ii proteases involved in host protein degradation such as an aspartic protease; iii proteins related to the oxidative burst such as glyoxal oxidase; iv proteins which may induce the plant hypersensitive response such as a cerato-platanin domain-containing protein; and v proteins related to production and secretion of toxins such as malate dehydrogenase. In this mini-review, we made an overview of the proteomics contribution to the study and knowledge of the B. cinerea extracellular secreted proteins based on our current work carried out from in vitro experiments, and recent published papers both in vitro and in planta studies on this fungi. We hypothesize on the putative functions of these secreted proteins, and their connection to the biology of the B. cinerea interaction with its hosts.

  17. The Nature of Child-Adult Interaction. From Turn-Taking to Understanding Pointing and Use of Pointing Gestures

    Directory of Open Access Journals (Sweden)

    Białek Arkadiusz

    2014-08-01

    Full Text Available Analyses of interactions between an adult and a one-year-old child are often connected with studying early communicative competences, e.g. the child’s participation in turn-taking sequences, in joint attention, and use of pointing gestures. Infants’ communicative behaviors were studied using a structured observational measure - the Early Social Communication Scales (Mundy et al., 2003 in a study of 358 12-month-old children. An exploratory factor analysis revealed: (i a distinction between the categories of initiation and response among the behaviors displayed, (ii simple and complex behavior categories occurring; (iii the presence within one factor of behaviors fulfilling various functions (e.g. requesting and sharing interest. An analysis of the results showed that communicative competences can be classified according to their level and ignoring their function, and made it possible to suggest modifications to the way in which behaviors are coded on the ESCS and to complement the procedure of studying early communicative competences.

  18. Understanding the Role of Air-Sea Interaction on Extreme Rainfall in Aquaplanet and Earth-like CESM2

    Science.gov (United States)

    Benedict, J. J.; Clement, A. C.; Medeiros, B.

    2017-12-01

    Extreme precipitation events are associated with anomalous, latitudinally dependent dynamical and convective weather systems. For example, plumes of excessive poleward water vapor transport and topographical effects drive extreme precipitation events in the midlatitudes, while intense tropical precipitation is associated with organized convective systems. In both cases, air-sea fluxes have the potential to contribute significantly to the moisture budget of these storms, but the roles of surface fluxes and upper-ocean processes and their impact on precipitation extremes have yet to be explored in sufficient detail. To examine such mechanisms, we implement a climate model hierarchy that encompasses a spectrum of ocean models, from prescribed-SST to fully dynamic, as well as both aquaplanet and Earth-like lower boundary types within version 2 of the Community Earth System Model (CESM2). Using the CESM2 hierarchy and comparing to observations, we identify key moisture processes and related air-sea interactions that drive extreme precipitation events across different latitudes in Earth-like models and then generalize the analyses in aquaplanet configurations to highlight the most salient features. The analyses are applied to both present-day and global warming conditions to investigate how these fundamental mechanisms might change extreme precipitation events in the future climate.

  19. Establishment and metabolic analysis of a model microbial community for understanding trophic and electron accepting interactions of subsurface anaerobic environments

    Directory of Open Access Journals (Sweden)

    Yang Zamin K

    2010-05-01

    Full Text Available Abstract Background Communities of microorganisms control the rates of key biogeochemical cycles, and are important for biotechnology, bioremediation, and industrial microbiological processes. For this reason, we constructed a model microbial community comprised of three species dependent on trophic interactions. The three species microbial community was comprised of Clostridium cellulolyticum, Desulfovibrio vulgaris Hildenborough, and Geobacter sulfurreducens and was grown under continuous culture conditions. Cellobiose served as the carbon and energy source for C. cellulolyticum, whereas D. vulgaris and G. sulfurreducens derived carbon and energy from the metabolic products of cellobiose fermentation and were provided with sulfate and fumarate respectively as electron acceptors. Results qPCR monitoring of the culture revealed C. cellulolyticum to be dominant as expected and confirmed the presence of D. vulgaris and G. sulfurreducens. Proposed metabolic modeling of carbon and electron flow of the three-species community indicated that the growth of C. cellulolyticum and D. vulgaris were electron donor limited whereas G. sulfurreducens was electron acceptor limited. Conclusions The results demonstrate that C. cellulolyticum, D. vulgaris, and G. sulfurreducens can be grown in coculture in a continuous culture system in which D. vulgaris and G. sulfurreducens are dependent upon the metabolic byproducts of C. cellulolyticum for nutrients. This represents a step towards developing a tractable model ecosystem comprised of members representing the functional groups of a trophic network.

  20. Ferenczi's concept of identification with the aggressor: understanding dissociative structure with interacting victim and abuser self-states.

    Science.gov (United States)

    Howell, Elizabeth F

    2014-03-01

    No one has described more passionately than Ferenczi the traumatic induction of dissociative trance with its resulting fragmentation of the personality. Ferenczi introduced the concept and term, identification with the aggressor in his seminal "Confusion of Tongues" paper, in which he described how the abused child becomes transfixed and robbed of his senses. Having been traumatically overwhelmed, the child becomes hypnotically transfixed by the aggressor's wishes and behavior, automatically identifying by mimicry rather than by a purposeful identification with the aggressor's role. To expand upon Ferenczi's observations, identification with the aggressor can be understood as a two-stage process. The first stage is automatic and initiated by trauma, but the second stage is defensive and purposeful. While identification with the aggressor begins as an automatic organismic process, with repeated activation and use, gradually it becomes a defensive process. Broadly, as a dissociative defense, it has two enacted relational parts, the part of the victim and the part of the aggressor. This paper describes the intrapersonal aspects (how aggressor and victim self-states interrelate in the internal world), as well as the interpersonal aspects (how these become enacted in the external). This formulation has relevance to understanding the broad spectrum of the dissociative structure of mind, borderline personality disorder, and dissociative identity disorder.

  1. Trend-outflow method for understanding interactions of surface water with groundwater and atmospheric water for eight reaches of the Upper Rio Grande

    Science.gov (United States)

    Liu, Yi; Sheng, Zhuping

    2011-11-01

    SummaryAtmospheric water, surface water, and groundwater interact very actively through hydrologic processes such as precipitation, infiltration, seepage, irrigation, drainage, evaporation, and evapotranspiration in the Upper Rio Grande Basin. A trend-outflow method has been developed in this paper to gain a better understanding of the interactions based on cumulated inflow and outflow data for any river reaches of interest. A general trend-outflow equation was derived by associating the net interaction of surface water with atmospheric water as a polynomial of inflow and the net interaction of surface water with groundwater as a constant based on surface water budget. Linear and quadratic relations are probably two common trend-outflow types in the real world. It was found that trend-outflows of the Upper Rio Grande reaches, Española, Albuquerque, Socorro-Engle, Palomas, and Rincon are linear with inflow, while those of reaches, Belen, Mesilla and Hueco are quadratic. Reaches Belen, Mesilla and Hueco are found as water deficit reaches mainly for irrigated agriculture in extreme drought years.

  2. Paternal Aging Affects Behavior in Pax6 Mutant Mice: A Gene/Environment Interaction in Understanding Neurodevelopmental Disorders.

    Science.gov (United States)

    Yoshizaki, Kaichi; Furuse, Tamio; Kimura, Ryuichi; Tucci, Valter; Kaneda, Hideki; Wakana, Shigeharu; Osumi, Noriko

    2016-01-01

    Neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention deficit and hyperactivity disorder (ADHD) have increased over the last few decades. These neurodevelopmental disorders are characterized by a complex etiology, which involves multiple genes and gene-environmental interactions. Various genes that control specific properties of neural development exert pivotal roles in the occurrence and severity of phenotypes associated with neurodevelopmental disorders. Moreover, paternal aging has been reported as one of the factors that contribute to the risk of ASD and ADHD. Here we report, for the first time, that paternal aging has profound effects on the onset of behavioral abnormalities in mice carrying a mutation of Pax6, a gene with neurodevelopmental regulatory functions. We adopted an in vitro fertilization approach to restrict the influence of additional factors. Comprehensive behavioral analyses were performed in Sey/+ mice (i.e., Pax6 mutant heterozygotes) born from in vitro fertilization of sperm taken from young or aged Sey/+ fathers. No body weight changes were found in the four groups, i.e., Sey/+ and wild type (WT) mice born to young or aged father. However, we found important differences in maternal separation-induced ultrasonic vocalizations of Sey/+ mice born from young father and in the level of hyperactivity of Sey/+ mice born from aged fathers in the open-field test, respectively, compared to WT littermates. Phenotypes of anxiety were observed in both genotypes born from aged fathers compared with those born from young fathers. No significant difference was found in social behavior and sensorimotor gating among the four groups. These results indicate that mice with a single genetic risk factor can develop different phenotypes depending on the paternal age. Our study advocates for serious considerations on the role of paternal aging in breeding strategies for animal studies.

  3. Paternal Aging Affects Behavior in Pax6 Mutant Mice: A Gene/Environment Interaction in Understanding Neurodevelopmental Disorders.

    Directory of Open Access Journals (Sweden)

    Kaichi Yoshizaki

    Full Text Available Neurodevelopmental disorders such as autism spectrum disorder (ASD and attention deficit and hyperactivity disorder (ADHD have increased over the last few decades. These neurodevelopmental disorders are characterized by a complex etiology, which involves multiple genes and gene-environmental interactions. Various genes that control specific properties of neural development exert pivotal roles in the occurrence and severity of phenotypes associated with neurodevelopmental disorders. Moreover, paternal aging has been reported as one of the factors that contribute to the risk of ASD and ADHD. Here we report, for the first time, that paternal aging has profound effects on the onset of behavioral abnormalities in mice carrying a mutation of Pax6, a gene with neurodevelopmental regulatory functions. We adopted an in vitro fertilization approach to restrict the influence of additional factors. Comprehensive behavioral analyses were performed in Sey/+ mice (i.e., Pax6 mutant heterozygotes born from in vitro fertilization of sperm taken from young or aged Sey/+ fathers. No body weight changes were found in the four groups, i.e., Sey/+ and wild type (WT mice born to young or aged father. However, we found important differences in maternal separation-induced ultrasonic vocalizations of Sey/+ mice born from young father and in the level of hyperactivity of Sey/+ mice born from aged fathers in the open-field test, respectively, compared to WT littermates. Phenotypes of anxiety were observed in both genotypes born from aged fathers compared with those born from young fathers. No significant difference was found in social behavior and sensorimotor gating among the four groups. These results indicate that mice with a single genetic risk factor can develop different phenotypes depending on the paternal age. Our study advocates for serious considerations on the role of paternal aging in breeding strategies for animal studies.

  4. Modelling Engagement in Multi-Party Conversations : Data-Driven Approaches to Understanding Human-Human Communication Patterns for Use in Human-Robot Interactions

    OpenAIRE

    Oertel, Catharine

    2016-01-01

    The aim of this thesis is to study human-human interaction in order to provide virtual agents and robots with the capability to engage into multi-party-conversations in a human-like-manner. The focus lies with the modelling of conversational dynamics and the appropriate realization of multi-modal feedback behaviour. For such an undertaking, it is important to understand how human-human communication unfolds in varying contexts and constellations over time. To this end, multi-modal human-human...

  5. Understanding kidney transplant patients' treatment choices: The interaction of emotion with medical and social influences on risk preferences.

    Science.gov (United States)

    Harrington, Jean; Morgan, Myfanwy

    2016-04-01

    Following renal transplantation patients experience on-going immunosuppressant medication to reduce the risk of graft rejection. Over the long term the side effects of immunosuppressive drugs may affect graft survival and significantly increase risks of cancers, stroke and cardiovascular disease. To reduce these risks research is underway to develop a biomarker test to identify those patients who are likely to be 'tolerant' to their graft and therefore able to reduce immunosuppression. Biomarker tests may however incorrectly identify some patients as tolerant, thus jeopardising their graft. Following a quantitative assessment of risk preferences we undertook a qualitative study to investigate the range of influences that shaped the substantial variations found in the level of risk transplant recipients were hypothetically willing to take. In-depth interviews were carried out in the United Kingdom between May 2013 and July 2014 with 24 transplant recipients all of whom had stable kidney graft function. These interviews identified a range of factors that patients take into account when making risk assessments, including familial views, trust and the ritual of 'gift exchange' that permeates the social space of kidney transplantation. Our data support the notion that emotion is not part of a linear process, preceding and separate to reason, but is intertwined with personal understanding and perception of risk and involves a complex interplay between different influences on decision-making. Our data also support Lupton's view that risk judgements are shared and collective rather than located within the individual and suggests that patient choice rather than involving a purely rational weighing of medical benefit is often based on influences that may not accord with the framework nor intention of medical professionals and medical research. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Hippocampal Temporal-Parietal Junction Interaction in the Production of Psychotic Symptoms: A Framework for Understanding the Schizophrenic Syndrome

    Directory of Open Access Journals (Sweden)

    Cynthia Gayle Wible

    2012-06-01

    Full Text Available A framework is described for understanding the schizophrenic syndrome at the brain systems level. It is hypothesized that over-activation of dynamic gesture and social perceptual processes in the temporal-parietal occipital junction (TPJ, posterior superior temporal sulcus (PSTS and surrounding regions produce the syndrome (including positive and negative symptoms, their prevalence, prodromal signs and cognitive deficits. Hippocampal system hyper-activity and atrophy have been consistently found in schizophrenia. Hippocampal activity is highly related to activity in the TPJ and may be a source of over-excitation of the TPJ and surrounding regions. Strong evidence for this comes from in-vivo recordings in humans during psychotic episodes. The TPJ and PSTS play a key role in the perception (and production of dynamic social, emotional and attentional gestures for the self and others (e.g., body/face/eye gestures, audiovisual speech, prosody. The single cell representation of dynamic gestures is multimodal (auditory, visual, tactile, matching the predominant hallucinatory categories in schizophrenia. Inherent in the single cell perceptual signal of dynamic gesture representations is a computation of intention, agency, and anticipation or expectancy (for the self and others. The neurons are also tuned or biased to detect threat related emotions. Abnormal over-activation in this system could produce the conscious hallucination of a voice (audiovisual speech, person or a touch. Over-activation could interfere with attentional/emotional gesture perception and production (negative symptoms. It could produce the unconscious feeling of being watched, followed or of a social situation unfolding along with accompanying perception of intent and agency inherent in those representations (delusions. Cognitive disturbances in attention, predictive social processing, agency, working memory, and a bias toward the perception of threat would also be predicted.

  7. The direct way may not be the best way: Children with ADHD and their understanding of self-presentation in social interactions

    Science.gov (United States)

    Kloo, Daniela; Kain, Winfried

    2016-01-01

    Knowledge and use of self-presentational tactics is an important social skill. We examined understanding of the function of three different self-presentational tactics (self-promotion, ingratiation and blasting) in 11 8–12-year-old boys with attention-deficit/hyperactivity disorder (ADHD) and 11 matched comparison children. Children were given six different self-presentation stories, two for each one of the three different tactics. After each story, they were asked to evaluate the effects of the self-presentational tactic used. Children with ADHD rated self-promotion and blasting as more positive and more effective—and ingratiation as less positive and less effective—than children in the control group. This implicates that children with ADHD prefer simple and direct self-presentational strategies (like self-promotion), and, therefore, may not as easily understand more subtle strategies (like ingratiation). They also seem to be more inclined to use negatively connoted strategies (like blasting). We suggest that this limited understanding of self-presentational strategies in children with ADHD may explain some of their problems in social interactions. Therefore, social skill interventions in children with ADHD should incorporate elements focusing on use and understanding of different self-presentational strategies. PMID:27081391

  8. Formation of complexes between hematite nanoparticles and a non-conventional galactomannan gum. Toward a better understanding on interaction processes.

    Science.gov (United States)

    Busch, Verónica M; Loosli, Fréderic; Santagapita, Patricio R; Buera, M Pilar; Stoll, Serge

    2015-11-01

    The physicochemical characteristics of hematite nanoparticles related to their size, surface area and reactivity make them useful for many applications, as well as suitable models to study aggregation kinetics. For several applications (such as remediation of contaminated groundwater) it is crucial to maintain the stability of hematite nanoparticle suspensions in order to assure their arrival to the target place. The use of biopolymers has been proposed as a suitable environmentally friendly option to avoid nanoparticle aggregation and assure their stability. The aim of the present work was to investigate the formation of complexes between hematite nanoparticles and a non-conventional galactomannan (vinal gum--VG) obtained from Prosopis ruscifolia in order to promote hematite nanoparticle coating with a green biopolymer. Zeta potential and size of hematite nanoparticles, VG dispersions and the stability of their mixtures were investigated, as well as the influence of the biopolymer concentration and preparation method. DLS and nanoparticle tracking analysis techniques were used for determining the size and the zeta-potential of the suspensions. VG showed a polydispersed size distribution (300-475 nm Z-average diameter, 0.65 Pdi) and a negative zeta potential (between -1 and -12 mV for pH2 and 12, respectively). The aggregation of hematite nanoparticles (3.3 mg/L) was induced by the addition of VG at lower concentrations than 2mg/L (pH5.5). On the other hand, hematite nanoparticles were stabilized at concentrations of VG higher than 2 mg/L. Several phenomena between hematite nanoparticles and VG were involved: steric effects, electrostatic interactions, charge neutralization, charge inversion and polymer bridging. The process of complexation between hematite nanoparticles and the biopolymer was strongly influenced by the preparation protocols. It was concluded that the aggregation, dispersion, and stability of hematite nanoparticles depended on biopolymer

  9. Integrating plant-microbe interactions to understand soil C stabilization with the MIcrobial-MIneral Carbon Stabilization model (MIMICS)

    Science.gov (United States)

    Grandy, Stuart; Wieder, Will; Kallenbach, Cynthia; Tiemann, Lisa

    2014-05-01

    If soil organic matter is predominantly microbial biomass, plant inputs that build biomass should also increase SOM. This seems obvious, but the implications fundamentally change how we think about the relationships between plants, microbes and SOM. Plant residues that build microbial biomass are typically characterized by low C/N ratios and high lignin contents. However, plants with high lignin contents and high C/N ratios are believed to increase SOM, an entrenched idea that still strongly motivates agricultural soil management practices. Here we use a combination of meta-analysis with a new microbial-explicit soil biogeochemistry model to explore the relationships between plant litter chemistry, microbial communities, and SOM stabilization in different soil types. We use the MIcrobial-MIneral Carbon Stabilization (MIMICS) model, newly built upon the Community Land Model (CLM) platform, to enhance our understanding of biology in earth system processes. The turnover of litter and SOM in MIMICS are governed by the activity of r- and k-selected microbial groups and temperature sensitive Michaelis-Menten kinetics. Plant and microbial residues are stabilized short-term by chemical recalcitrance or long-term by physical protection. Fast-turnover litter inputs increase SOM by >10% depending on temperature in clay soils, and it's only in sandy soils devoid of physical protection mechanisms that recalcitrant inputs build SOM. These results challenge centuries of lay knowledge as well as conventional ideas of SOM formation, but are they realistic? To test this, we conducted a meta-analysis of the relationships between the chemistry of plant liter inputs and SOM concentrations. We find globally that the highest SOM concentrations are associated with plant inputs containing low C/N ratios. These results are confirmed by individual tracer studies pointing to greater stabilization of low C/N ratio inputs, particularly in clay soils. Our model and meta-analysis results suggest

  10. Analysis of protein targets in pathogen-host interaction in infectious diseases: a case study on Plasmodium falciparum and Homo sapiens interaction network.

    Science.gov (United States)

    Saha, Sovan; Sengupta, Kaustav; Chatterjee, Piyali; Basu, Subhadip; Nasipuri, Mita

    2017-09-23

    Infection and disease progression is the outcome of protein interactions between pathogen and host. Pathogen, the role player of Infection, is becoming a severe threat to life as because of its adaptability toward drugs and evolutionary dynamism in nature. Identifying protein targets by analyzing protein interactions between host and pathogen is the key point. Proteins with higher degree and possessing some topologically significant graph theoretical measures are found to be drug targets. On the other hand, exceptional nodes may be involved in infection mechanism because of some pathway process and biologically unknown factors. In this article, we attempt to investigate characteristics of host-pathogen protein interactions by presenting a comprehensive review of computational approaches applied on different infectious diseases. As an illustration, we have analyzed a case study on infectious disease malaria, with its causative agent Plasmodium falciparum acting as 'Bait' and host, Homo sapiens/human acting as 'Prey'. In this pathogen-host interaction network based on some interconnectivity and centrality properties, proteins are viewed as central, peripheral, hub and non-hub nodes and their significance on infection process. Besides, it is observed that because of sparseness of the pathogen and host interaction network, there may be some topologically unimportant but biologically significant proteins, which can also act as Bait/Prey. So, functional similarity or gene ontology mapping can help us in this case to identify these proteins. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Teaching Teaching & Understanding Understanding

    DEFF Research Database (Denmark)

    2006-01-01

    "Teaching Teaching & Understanding Understanding" is a 19-minute award-winning short-film about teaching at university and higher-level educational institutions. It is based on the "Constructive Alignment" theory developed by Prof. John Biggs. The film delivers a foundation for understanding what...

  12. Moving college students to a better understanding of substrate specificity of enzymes through utilizing multimedia pre-training and an interactive enzyme model

    Science.gov (United States)

    Saleh, Mounir R.

    Scientists' progress in understanding enzyme specificity uncovered a complex natural phenomenon. However, not all of the currently available biology textbooks seem to be up to date on this progress. Students' understanding of how enzymes work is a core requirement in biochemistry and biology tertiary education. Nevertheless, current pre-college science education does not provide students with enough biochemical background to enable them to understand complex material such as this. To bridge this gap, a multimedia pre-training presentation was prepared to fuel the learner's prior knowledge with discrete facts necessary to understand the presented concept. This treatment is also known to manage intrinsic cognitive load during the learning process. An interactive instructional enzyme model was also built to motivate students to learn about substrate specificity of enzymes. Upon testing the effect of this combined treatment on 111 college students, desirable learning outcomes were found in terms of cognitive load, motivation, and achievement. The multimedia pre-training group reported significantly less intrinsic cognitive load, higher motivation, and demonstrated higher transfer performance than the control and post-training groups. In this study, a statistical mediation model is also proposed to explain how cognitive load and motivation work in concert to foster learning from multimedia pre-training. This type of research goes beyond simple forms of "what works" to a deeper understanding of "how it works", thus enabling informed decisions for multimedia instructional design. Multimedia learning plays multiple roles in science education. Therefore, science learners would be some of the first to benefit from improving multimedia instructional design. Accordingly, complex scientific phenomena can be introduced to college students in a motivating, informative, and cognitively efficient learning environment.

  13. How Our Cognition Shapes and Is Shaped by Technology: A Common Framework for Understanding Human Tool-Use Interactions in the Past, Present, and Future

    Directory of Open Access Journals (Sweden)

    François Osiurak

    2018-03-01

    Full Text Available Over the evolution, humans have constantly developed and improved their technologies. This evolution began with the use of physical tools, those tools that increase our sensorimotor abilities (e.g., first stone tools, modern knives, hammers, pencils. Although we still use some of these tools, we also employ in daily life more sophisticated tools for which we do not systematically understand the underlying physical principles (e.g., computers, cars. Current research is also turned toward the development of brain–computer interfaces directly linking our brain activity to machines (i.e., symbiotic tools. The ultimate goal of research on this topic is to identify the key cognitive processes involved in these different modes of interaction. As a primary step to fulfill this goal, we offer a first attempt at a common framework, based on the idea that humans shape technologies, which also shape us in return. The framework proposed is organized into three levels, describing how we interact when using physical (Past, sophisticated (Present, and symbiotic (Future technologies. Here we emphasize the role played by technical reasoning and practical reasoning, two key cognitive processes that could nevertheless be progressively suppressed by the proficient use of sophisticated and symbiotic tools. We hope that this framework will provide a common ground for researchers interested in the cognitive basis of human tool-use interactions, from paleoanthropology to neuroergonomics.

  14. Interactive case vignettes utilizing simulated pathologist-clinician encounters with whole slide imaging and video tutorials of whole slide scans improves student understanding of disease processes

    Directory of Open Access Journals (Sweden)

    Adam J Horn

    2012-01-01

    Full Text Available Background: One of the drawbacks of studying pathology in the second year of medical school in a classroom setting is the relatively limited exposure to patient encounters/clinical rotations, making it difficult to understand and fully appreciate the significance of the course material, specifically the molecular and tissue aspects of disease. In this study, we determined if case vignettes incorporating pathologist-clinician encounters with whole slide imaging (WSI and narrated/annotated videos of whole slide (WS scans in addition to clinical data improved student understanding of pathologic disease processes. Materials and Methods: Case vignettes were created for several genitourinary disease processes that utilized clinical data including narratives of pathologist-clinician encounters, WSI, and annotated video tutorials of WS scans (designed to simulate "double-heading". The students were encouraged to view the virtual slide first, with the video tutorials being provided to offer additional assistance. The case vignettes were created to be interactive with a detailed explanation of each correct and incorrect question choice. The cases were made available to all second year medical students via a website and could be viewed only after completing a 10 question pre-test. A post-test could be completed after viewing all cases followed by a brief satisfaction survey. Results: Ninety-six students completed the pre-test with an average score of 7.7/10. Fifty-seven students completed the post-test with an average score of 9.4/10. Thirty-six students completed the satisfaction survey. 94% agreed or strongly agreed that this was a useful exercise and 91% felt that it helped them better understand the topics. Conclusion: The development of interactive case vignettes incorporating simulated pathologist-clinician encounters with WSI and video tutorials of WS scans helps to improve student enthusiasm to learn and grasp pathologic aspects of disease

  15. Understanding unemployment

    OpenAIRE

    Guillaume Rocheteau

    2006-01-01

    Modern economists have built models of the labor market, which isolate the market’s key drivers and describe the way these interact to produce particular levels of unemployment. One of the most popular models used by macroeconomists today is the search-matching model of equilibrium unemployment. We explain this model, and show how it can be applied to understand the way various policies, such as unemployment benefits, taxes, or technological changes, can affect the unemployment rate.

  16. Signatures of pleiotropy, economy and convergent evolution in a domain-resolved map of human-virus protein-protein interaction networks.

    Directory of Open Access Journals (Sweden)

    Sara Garamszegi

    Full Text Available A central challenge in host-pathogen systems biology is the elucidation of general, systems-level principles that distinguish host-pathogen interactions from within-host interactions. Current analyses of host-pathogen and within-host protein-protein interaction networks are largely limited by their resolution, treating proteins as nodes and interactions as edges. Here, we construct a domain-resolved map of human-virus and within-human protein-protein interaction networks by annotating protein interactions with high-coverage, high-accuracy, domain-centric interaction mechanisms: (1 domain-domain interactions, in which a domain in one protein binds to a domain in a second protein, and (2 domain-motif interactions, in which a domain in one protein binds to a short, linear peptide motif in a second protein. Analysis of these domain-resolved networks reveals, for the first time, significant mechanistic differences between virus-human and within-human interactions at the resolution of single domains. While human proteins tend to compete with each other for domain binding sites by means of sequence similarity, viral proteins tend to compete with human proteins for domain binding sites in the absence of sequence similarity. Independent of their previously established preference for targeting human protein hubs, viral proteins also preferentially target human proteins containing linear motif-binding domains. Compared to human proteins, viral proteins participate in more domain-motif interactions, target more unique linear motif-binding domains per residue, and contain more unique linear motifs per residue. Together, these results suggest that viruses surmount genome size constraints by convergently evolving multiple short linear motifs in order to effectively mimic, hijack, and manipulate complex host processes for their survival. Our domain-resolved analyses reveal unique signatures of pleiotropy, economy, and convergent evolution in viral

  17. Signatures of pleiotropy, economy and convergent evolution in a domain-resolved map of human-virus protein-protein interaction networks.

    Science.gov (United States)

    Garamszegi, Sara; Franzosa, Eric A; Xia, Yu

    2013-01-01

    A central challenge in host-pathogen systems biology is the elucidation of general, systems-level principles that distinguish host-pathogen interactions from within-host interactions. Current analyses of host-pathogen and within-host protein-protein interaction networks are largely limited by their resolution, treating proteins as nodes and interactions as edges. Here, we construct a domain-resolved map of human-virus and within-human protein-protein interaction networks by annotating protein interactions with high-coverage, high-accuracy, domain-centric interaction mechanisms: (1) domain-domain interactions, in which a domain in one protein binds to a domain in a second protein, and (2) domain-motif interactions, in which a domain in one protein binds to a short, linear peptide motif in a second protein. Analysis of these domain-resolved networks reveals, for the first time, significant mechanistic differences between virus-human and within-human interactions at the resolution of single domains. While human proteins tend to compete with each other for domain binding sites by means of sequence similarity, viral proteins tend to compete with human proteins for domain binding sites in the absence of sequence similarity. Independent of their previously established preference for targeting human protein hubs, viral proteins also preferentially target human proteins containing linear motif-binding domains. Compared to human proteins, viral proteins participate in more domain-motif interactions, target more unique linear motif-binding domains per residue, and contain more unique linear motifs per residue. Together, these results suggest that viruses surmount genome size constraints by convergently evolving multiple short linear motifs in order to effectively mimic, hijack, and manipulate complex host processes for their survival. Our domain-resolved analyses reveal unique signatures of pleiotropy, economy, and convergent evolution in viral-host interactions that are

  18. Stringent DDI-based prediction of H. sapiens-M. tuberculosis H37Rv protein-protein interactions.

    Science.gov (United States)

    Zhou, Hufeng; Rezaei, Javad; Hugo, Willy; Gao, Shangzhi; Jin, Jingjing; Fan, Mengyuan; Yong, Chern-Han; Wozniak, Michal; Wong, Limsoon

    2013-01-01

    H. sapiens-M. tuberculosis H37Rv protein-protein interaction (PPI) data are very important information to illuminate the infection mechanism of M. tuberculosis H37Rv. But current H. sapiens-M. tuberculosis H37Rv PPI data are very scarce. This seriously limits the study of the interaction between this important pathogen and its host H. sapiens. Computational prediction of H. sapiens-M. tuberculosis H37Rv PPIs is an important strategy to fill in the gap. Domain-domain interaction (DDI) based prediction is one of the frequently used computational approaches in predicting both intra-species and inter-species PPIs. However, the performance of DDI-based host-pathogen PPI prediction has been rather limited. We develop a stringent DDI-based prediction approach with emphasis on (i) differences between the specific domain sequences on annotated regions of proteins under the same domain ID and (ii) calculation of the interaction strength of predicted PPIs based on the interacting residues in their interaction interfaces. We compare our stringent DDI-based approach to a conventional DDI-based approach for predicting PPIs based on gold standard intra-species PPIs and coherent informative Gene Ontology terms assessment. The assessment results show that our stringent DDI-based approach achieves much better performance in predicting PPIs than the conventional approach. Using our stringent DDI-based approach, we have predicted a small set of reliable H. sapiens-M. tuberculosis H37Rv PPIs which could be very useful for a variety of related studies. We also analyze the H. sapiens-M. tuberculosis H37Rv PPIs predicted by our stringent DDI-based approach using cellular compartment distribution analysis, functional category enrichment analysis and pathway enrichment analysis. The analyses support the validity of our prediction result. Also, based on an analysis of the H. sapiens-M. tuberculosis H37Rv PPI network predicted by our stringent DDI-based approach, we have discovered some

  19. Embodied Understanding

    Directory of Open Access Journals (Sweden)

    Mark Leonard Johnson

    2015-06-01

    Full Text Available Western culture has inherited a view of understanding as an intellectual cognitive operation of grasping of concepts and their relations. However, cognitive science research has shown that this received intellectualist conception is substantially out of touch with how humans actually make and experience meaning. The view emerging from the mind sciences recognizes that understanding is profoundly embodied, insofar as our conceptualization and reasoning recruit sensory, motor, and affective patterns and processes to structure our understanding of, and engagement with, our world. A psychologically realistic account of understanding must begin with the patterns of ongoing interaction between an organism and its physical and cultural environments and must include both our emotional responses to changes in our body and environment, and also the actions by which we continuously transform our experience. Consequently, embodied understanding is not merely a conceptual/propositional activity of thought, but rather constitutes our most basic way of being in, and engaging with, our surroundings in a deep visceral manner.

  20. Use of the ARM Measurements of Spectral Zenith Radiance for Better Understanding of 3D Cloud-Radiation Processes & Aerosol-Cloud Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Alexander Marshak; Warren Wiscombe; Yuri Knyazikhin; Christine Chiu

    2011-05-24

    We proposed a variety of tasks centered on the following question: what can we learn about 3D cloud-radiation processes and aerosol-cloud interaction from rapid-sampling ARM measurements of spectral zenith radiance? These ARM measurements offer spectacular new and largely unexploited capabilities in both the temporal and spectral domains. Unlike most other ARM instruments, which average over many seconds or take samples many seconds apart, the new spectral zenith radiance measurements are fast enough to resolve natural time scales of cloud change and cloud boundaries as well as the transition zone between cloudy and clear areas. In the case of the shortwave spectrometer, the measurements offer high time resolution and high spectral resolution, allowing new discovery-oriented science which we intend to pursue vigorously. Research objectives are, for convenience, grouped under three themes: • Understand radiative signature of the transition zone between cloud-free and cloudy areas using data from ARM shortwave radiometers, which has major climatic consequences in both aerosol direct and indirect effect studies. • Provide cloud property retrievals from the ARM sites and the ARM Mobile Facility for studies of aerosol-cloud interactions. • Assess impact of 3D cloud structures on aerosol properties using passive and active remote sensing techniques from both ARM and satellite measurements.

  1. Transcriptome profiling during a natural host-parasite interaction.

    Science.gov (United States)

    McTaggart, Seanna J; Cézard, Timothée; Garbutt, Jennie S; Wilson, Phil J; Little, Tom J

    2015-08-28

    Infection outcome in some coevolving host-pathogens is characterised by host-pathogen genetic interactions, where particular host genotypes are susceptible only to a subset of pathogen genotypes. To identify candidate genes responsible for the infection status of the host, we exposed a Daphnia magna host genotype to two bacterial strains of Pasteuria ramosa, one of which results in infection, while the other does not. At three time points (four, eight and 12 h) post pathogen exposure, we sequenced the complete transcriptome of the hosts using RNA-Seq (Illumina). We observed a rapid and transient response to pathogen treatment. Specifically, at the four-hour time point, eight genes were differentially expressed. At the eight-hour time point, a single gene was differentially expressed in the resistant combination only, and no genes were differentially expressed at the 12-h time point. We found that pathogen-associated transcriptional activity is greatest soon after exposure. Genome-wide resistant combinations were more likely to show upregulation of genes, while susceptible combinations were more likely to be downregulated, relative to controls. Our results also provide several novel candidate genes that may play a pivotal role in determining infection outcomes.

  2. Grafting computer projected simulations and interactive engagement methods within a traditional classroom setting: The influence on secondary level students' understanding of Newtonian mechanics and on attitudes towards physics

    Science.gov (United States)

    Zoubeir, Wassim Fouad

    This research explored the effects of a constructivist approach using computer projected simulations (CPS) and interactive engagement (IE) methods on 12th grade school students. The treatment lasted 18 weeks during the 1999-2000 fall semester and seeked to evaluate three variations in students': (1)conceptual understanding of Newtonian mechanics as measured by the Force Concept Inventory (FCI), (2)modification of their views about science as measured by the Views About Science Survey (VASS), and (3)achievement on traditional examinations, as measured by their end of semester grades. Analysis of Covariance (ANCOVA) was applied to determine the differences between the mean scores of the experimental group students, and students of the control group, who were exposed to traditional teaching methods only. The FCI data analysis showed that, after 18 weeks, conceptual understanding of Newtonian mechanics had markedly improved only in the experimental group (F(1,99) = 44.739, p performance on the VASS instrument for both groups (F(1,99) = .033, p = .856), confirming previous and comparable findings for studies of short implementation period. The lack of statistically significant difference between the control and experimental groups in graded achievement, while controlling for students' previous achievement, was unexpected (F(1,99) = 1.178, p = .280). It is suggested that in this particular setting, the influence of a technical factor may have been overlooked: the monitored and systematic drill exercises using elaborate math formulae to prepare students for traditional math-loaded exams. Still, despite being intentionally deprived of such preparation throughout the study, students of the experimental group did not achieve less than their counterpart, and in addition, they had gained a satisfactory understanding of Newtonian mechanics. This result points unmistakably at a plausible positive correlation between a better grasp of basic concepts in physics in a challenging

  3. Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4-CO2-H2O) Interactions in Shale Nanopores under Reservoir Conditions.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yifeng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-02-01

    Shale is characterized by the predominant presence of nanometer-scale (1-100 nm) pores. The behavior of fluids in those pores directly controls shale gas storage and release in shale matrix and ultimately the wellbore production in unconventional reservoirs. Recently, it has been recognized that a fluid confined in nanopores can behave dramatically differently from the corresponding bulk phase due to nanopore confinement (Wang, 2014). CO2 and H2O, either preexisting or introduced, are two major components that coexist with shale gas (predominately CH4) during hydrofracturing and gas extraction. Note that liquid or supercritical CO2 has been suggested as an alternative fluid for subsurface fracturing such that CO2 enhanced gas recovery can also serve as a CO2 sequestration process. Limited data indicate that CO2 may preferentially adsorb in nanopores (particularly those in kerogen) and therefore displace CH4 in shale. Similarly, the presence of water moisture seems able to displace or trap CH4 in shale matrix. Therefore, fundamental understanding of CH4-CO2-H2O behavior and their interactions in shale nanopores is of great importance for gas production and the related CO2 sequestration. This project focuses on the systematic study of CH4-CO2-H2O interactions in shale nanopores under high-pressure and high temperature reservoir conditions. The proposed work will help to develop new stimulation strategies to enable efficient resource recovery from fewer and less environmentally impactful wells.

  4. Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4-CO2-H2O) Interactions in Shale Nanopores under Reservoir Conditions: Quarterly Report.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yifeng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-11-01

    Shale is characterized by the predominant presence of nanometer-scale (1-100 nm) pores. The behavior of fluids in those pores directly controls shale gas storage and release in shale matrix and ultimately the wellbore production in unconventional reservoirs. Recently, it has been recognized that a fluid confined in nanopores can behave dramatically differently from the corresponding bulk phase due to nanopore confinement (Wang, 2014). CO2 and H2O, either preexisting or introduced, are two major components that coexist with shale gas (predominately CH4) during hydrofracturing and gas extraction. Note that liquid or supercritical CO2 has been suggested as an alternative fluid for subsurface fracturing such that CO2 enhanced gas recovery can also serve as a CO2 sequestration process. Limited data indicate that CO2 may preferentially adsorb in nanopores (particularly those in kerogen) and therefore displace CH4 in shale. Similarly, the presence of water moisture seems able to displace or trap CH4 in shale matrix. Therefore, fundamental understanding of CH4-CO2-H2O behavior and their interactions in shale nanopores is of great importance for gas production and the related CO2 sequestration. This project focuses on the systematic study of CH4-CO2-H2O interactions in shale nanopores under high-pressure and high temperature reservoir conditions. The proposed work will help to develop new stimulation strategies to enable efficient resource recovery from fewer and less environmentally impactful wells.

  5. Towards Improving our Understanding on the Retrievals of Key Parameters Characterising Land Surface Interactions from Space: Introduction & First Results from the PREMIER-EO Project

    Science.gov (United States)

    Ireland, Gareth; North, Matthew R.; Petropoulos, George P.; Srivastava, Prashant K.; Hodges, Crona

    2015-04-01

    Acquiring accurate information on the spatio-temporal variability of soil moisture content (SM) and evapotranspiration (ET) is of key importance to extend our understanding of the Earth system's physical processes, and is also required in a wide range of multi-disciplinary research studies and applications. The utility and applicability of Earth Observation (EO) technology provides an economically feasible solution to derive continuous spatio-temporal estimates of key parameters characterising land surface interactions, including ET as well as SM. Such information is of key value to practitioners, decision makers and scientists alike. The PREMIER-EO project recently funded by High Performance Computing Wales (HPCW) is a research initiative directed towards the development of a better understanding of EO technology's present ability to derive operational estimations of surface fluxes and SM. Moreover, the project aims at addressing knowledge gaps related to the operational estimation of such parameters, and thus contribute towards current ongoing global efforts towards enhancing the accuracy of those products. In this presentation we introduce the PREMIER-EO project, providing a detailed overview of the research aims and objectives for the 1 year duration of the project's implementation. Subsequently, we make available the initial results of the work carried out herein, in particular, related to an all-inclusive and robust evaluation of the accuracy of existing operational products of ET and SM from different ecosystems globally. The research outcomes of this project, once completed, will provide an important contribution towards addressing the knowledge gaps related to the operational estimation of ET and SM. This project results will also support efforts ongoing globally towards the operational development of related products using technologically advanced EO instruments which were launched recently or planned be launched in the next 1-2 years. Key Words: PREMIER

  6. Pan-Eurasian Experiment (PEEX: towards a holistic understanding of the feedbacks and interactions in the land–atmosphere–ocean–society continuum in the northern Eurasian region

    Directory of Open Access Journals (Sweden)

    H. K. Lappalainen

    2016-11-01

    Full Text Available The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic–boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX, a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/. PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land–atmosphere–aquatic–society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context.

  7. Phages of lactic acid bacteria: The role of genetics in understanding phage-host interactions and their co-evolutionary processes

    International Nuclear Information System (INIS)

    Mahony, Jennifer; Ainsworth, Stuart; Stockdale, Stephen; Sinderen, Douwe van

    2012-01-01

    Dairy fermentations are among the oldest food processing applications, aimed at preservation and shelf-life extension through the use of lactic acid bacteria (LAB) starter cultures, in particular strains of Lactococcus lactis, Streptococcus thermophilus, Lactobacillus spp. and Leuconostoc spp. Traditionally this was performed by continuous passaging of undefined cultures from a finished fermentation to initiate the next fermentation. More recently, consumer demands on consistent and desired flavours and textures of dairy products have led to a more defined approach to such processes. Dairy (starter) companies have responded to the need to define the nature and complexity of the starter culture mixes, and dairy fermentations are now frequently based on defined starter cultures of low complexity, where each starter component imparts specific technological properties that are desirable to the product. Both mixed and defined starter culture approaches create the perfect environment for the proliferation of (bacterio)phages capable of infecting these LAB. The repeated use of the same starter cultures in a single plant, coupled to the drive towards higher and consistent production levels, increases the risk and negative impact of phage infection. In this review we will discuss recent advances in tracking the adaptation of phages to the dairy industry, the advances in understanding LAB phage-host interactions, including evolutionary and genomic aspects.

  8. Phages of lactic acid bacteria: The role of genetics in understanding phage-host interactions and their co-evolutionary processes

    Energy Technology Data Exchange (ETDEWEB)

    Mahony, Jennifer, E-mail: j.mahony@ucc.ie [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Ainsworth, Stuart; Stockdale, Stephen [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Sinderen, Douwe van, E-mail: d.vansinderen@ucc.ie [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Alimentary Pharmabiotic Centre, Biosciences Institute, University College Cork, Western Road, Cork (Ireland)

    2012-12-20

    Dairy fermentations are among the oldest food processing applications, aimed at preservation and shelf-life extension through the use of lactic acid bacteria (LAB) starter cultures, in particular strains of Lactococcus lactis, Streptococcus thermophilus, Lactobacillus spp. and Leuconostoc spp. Traditionally this was performed by continuous passaging of undefined cultures from a finished fermentation to initiate the next fermentation. More recently, consumer demands on consistent and desired flavours and textures of dairy products have led to a more defined approach to such processes. Dairy (starter) companies have responded to the need to define the nature and complexity of the starter culture mixes, and dairy fermentations are now frequently based on defined starter cultures of low complexity, where each starter component imparts specific technological properties that are desirable to the product. Both mixed and defined starter culture approaches create the perfect environment for the proliferation of (bacterio)phages capable of infecting these LAB. The repeated use of the same starter cultures in a single plant, coupled to the drive towards higher and consistent production levels, increases the risk and negative impact of phage infection. In this review we will discuss recent advances in tracking the adaptation of phages to the dairy industry, the advances in understanding LAB phage-host interactions, including evolutionary and genomic aspects.

  9. Possible Roles of Ectophosphatases in Host-Parasite Interactions

    Directory of Open Access Journals (Sweden)

    Marta T. Gomes

    2011-01-01

    Full Text Available The interaction and survival of pathogens in hostile environments and in confrontation with host immune responses are important mechanisms for the establishment of infection. Ectophosphatases are enzymes localized at the plasma membrane of cells, and their active sites face the external medium rather than the cytoplasm. Once activated, these enzymes are able to hydrolyze phosphorylated substrates in the extracellular milieu. Several studies demonstrated the presence of surface-located ecto-phosphatases in a vast number of pathogenic organisms, including bacteria, protozoa, and fungi. Little is known about the role of ecto-phosphatases in host-pathogen interactions. The present paper provides an overview of recent findings related to the virulence induced by these surface molecules in protozoa and fungi.

  10. Networks of Interacting Processes: Relationships Between Drivers and Deltaic Variables to Understand Water and Sediment Transport in Wax Lake Delta, Coastal Louisiana

    Science.gov (United States)

    Sendrowski, A.; Passalacqua, P.; Wagner, W.; Mohrig, D. C.; Meselhe, E. A.; Sadid, K. M.; Castañeda-Moya, E.; Twilley, R.

    2017-12-01

    Studying distributary channel networks in river deltaic systems provides important insight into deltaic functioning and evolution. This view of networks highlights the physical connection along channels and can also encompass the structural link between channels and deltaic islands (termed structural connectivity). An alternate view of the deltaic network is one composed of interacting processes, such as relationships between external drivers (e.g., river discharge, tides, and wind) and internal deltaic response variables (e.g., water level and sediment concentration). This network, also referred to as process connectivity, is dynamic across space and time, often comprises nonlinear relationships, and contributes to the development of complex channel networks and ecologically rich island platforms. The importance of process connectivity has been acknowledged, however, few studies have directly quantified these network interactions. In this work, we quantify process connections in Wax Lake Delta (WLD), coastal Louisiana. WLD is a naturally prograding delta that serves as an analogue for river diversion projects, thus it provides an excellent setting for understanding the influence of river discharge, tides, and wind on water and sediment in a delta. Time series of water level and sediment concentration were collected in three channels from November 2013 to February 2014, while water level and turbidity were collected on an island from April 2014 to August 2015. Additionally, a model run on WLD bathymetry generated two years of sediment concentration time series in multiple channels. River discharge, tide, and wind measurements were collected from the USGS and NOAA, respectively. We analyze this data with information theory (IT), a set of statistics that measure uncertainty in signals and communication between signals. Using IT, the timescale, strength, and direction of network links are quantified by measuring the synchronization and direct influence from one

  11. Conflict or synergy? Understanding interaction between municipalities and village commons (regole in polycentric governance of mountain areas in the Veneto Region, Italy

    Directory of Open Access Journals (Sweden)

    Matteo Favero

    2016-08-01

    Full Text Available A particular challenge for mountainous areas in Italy is the definition of suitable governance models for local resources. Several solutions have been proposed over time, resulting in the co-existence of a number of decision-making centers. A crucial role is played by municipalities, but, in recent years, village commons – regola (singular / regole (plural in the local language – have been re-constituted as institutions with local power. In this dynamic context, little is known on how municipalities and regole interact. This paper aims at improving the understanding of local governance of mountain areas in the Veneto Region, from the viewpoint of municipalities, which represent the political, legal and administrative authority. The analysis is grounded in the polycentric governance literature, especially crucial in drawing attention to level and extent of cooperation, trustworthiness, mutual learning and effort for adaptation. Tensions, conflicts and conflict-resolution mechanisms were also assessed. We carried out a survey of 14 municipalities containing regole within their administrative jurisdictions. The results of our work provide evidence that this relationship is mostly a synergistic one. Municipalities showed adaptive capacity in mirroring values and views of the regole and proved willing to share responsibilities. Their decisions were formulated whilst taking into account the need for creating the appropriate linkages with local communities. Where conflicts or discontent have emerged, they have been mostly resolved, or considered as reflecting a need for greater coordination. This outcome can be looked upon as a local polycentric governance innovation that so far has only partially received policy support at the regional level. We conclude that municipalities will continue to play a central role in regulation of local-level socio-economic dynamics, remaining the institutional reference point for mountainous areas in the Veneto

  12. The Use of Three Dimensional Printed Interactive Models and a Digital Anatomy Case Study to Improve Medical Student Understanding of Pelvic and Perineal Anatomy

    Science.gov (United States)

    Solis, Laura de Jesus

    The anatomy of the pelvis and perineum is especially complex for novice students. In the Language of Medicine Module (Gross Anatomy and Embryology), medical students are expected to learn a high volume of material in a short time. The study of these regions is especially challenging due to the limited visibility of structures and difficulty of dissection. Understanding of the spatial relationships of the pelvic and perineal structures is important to acquire the foundational knowledge for future clinical application. Traditional methods such as dissection, prosected specimens, peer teaching, and radiological images are used at UT Health San Antonio to teach these regions. Emerging three dimensional technologies applied in computer based models and printed physical models serve as alternative ways to teach Anatomy. This study examines the effectiveness of adding two active learning methods that use these technologies to teach the anatomy of the pelvis and perineum in the Language of Medicine module, as assessed by exam performance and a satisfaction survey. The learning methods included female pelvic and perineal printed models with simulated anatomical contents made with arts and crafts material, and a digital anatomy case study using BodyVizRTM. In 2016, 220 medical students in four groups (A-D) rotated between demonstrations on prosected cadavers and interactive sessions with each 3D learning tool. Student exam performance was assessed as the percentage of points obtained on select written and practical exam questions relevant to the anatomy of the pelvis and perineum. Across four years, practical exam performance for all relevant pelvic and perineal tags (structures tagged with a string or pin) shows a consistent decline of averages from 2013 (83%) to 2015 (75.7%). This decline was slightly reversed in 2016 (76.6%) following the integration of the 3D learning tools. The analysis of the obturator internus muscle tag, a tag included in the practical exams across

  13. Hemoparasites in a wild primate: Infection patterns suggest interaction of Plasmodium and Babesia in a lemur species

    Directory of Open Access Journals (Sweden)

    Andrea Springer

    2015-12-01

    Full Text Available Hemoparasites can cause serious morbidity in humans and animals and often involve wildlife reservoirs. Understanding patterns of hemoparasite infections in natural populations can therefore inform about emerging disease risks, especially in the light of climate change and human disruption of natural ecosystems. We investigated the effects of host age, sex, host group size and season on infection patterns of Plasmodium sp., Babesia sp. and filarial nematodes in a population of wild Malagasy primates, Verreaux's sifakas (Propithecus verreauxi, as well as the effects of these infections on hematological variables. We tested 45 blood samples from 36 individuals and identified two species of Plasmodium, one species of Babesia and two species of filarial nematodes. Plasmodium spp. and Babesia sp. infections showed opposite patterns of age-dependency, with babesiosis being prevalent among young animals, while older animals were infected with Plasmodium sp. In addition, Babesia sp. infection was a statistically significant negative predictor of Plasmodium sp. infection. These results suggest that Plasmodium and Babesia parasites may interact within the host, either through cross-immunity or via resource competition, so that Plasmodium infections can only establish after babesiosis has resolved. We found no effects of host sex, host group size and season on hemoparasite infections. Infections showed high prevalences and did not influence hematological variables. This preliminary evidence supports the impression that the hosts and parasites considered in this study appear to be well-adapted to each other, resulting in persistent infections with low pathogenic and probably low zoonotic potential. Our results illustrate the crucial role of biodiversity in host-parasite relationships, specifically how within-host pathogen diversity may regulate the abundance of parasites.

  14. Hemoparasites in a wild primate: Infection patterns suggest interaction of Plasmodium and Babesia in a lemur species.

    Science.gov (United States)

    Springer, Andrea; Fichtel, Claudia; Calvignac-Spencer, Sébastien; Leendertz, Fabian H; Kappeler, Peter M

    2015-12-01

    Hemoparasites can cause serious morbidity in humans and animals and often involve wildlife reservoirs. Understanding patterns of hemoparasite infections in natural populations can therefore inform about emerging disease risks, especially in the light of climate change and human disruption of natural ecosystems. We investigated the effects of host age, sex, host group size and season on infection patterns of Plasmodium sp., Babesia sp. and filarial nematodes in a population of wild Malagasy primates, Verreaux's sifakas (Propithecus verreauxi), as well as the effects of these infections on hematological variables. We tested 45 blood samples from 36 individuals and identified two species of Plasmodium, one species of Babesia and two species of filarial nematodes. Plasmodium spp. and Babesia sp. infections showed opposite patterns of age-dependency, with babesiosis being prevalent among young animals, while older animals were infected with Plasmodium sp. In addition, Babesia sp. infection was a statistically significant negative predictor of Plasmodium sp. infection. These results suggest that Plasmodium and Babesia parasites may interact within the host, either through cross-immunity or via resource competition, so that Plasmodium infections can only establish after babesiosis has resolved. We found no effects of host sex, host group size and season on hemoparasite infections. Infections showed high prevalences and did not influence hematological variables. This preliminary evidence supports the impression that the hosts and parasites considered in this study appear to be well-adapted to each other, resulting in persistent infections with low pathogenic and probably low zoonotic potential. Our results illustrate the crucial role of biodiversity in host-parasite relationships, specifically how within-host pathogen diversity may regulate the abundance of parasites.

  15. Hemoparasites in a wild primate: Infection patterns suggest interaction of Plasmodium and Babesia in a lemur species☆

    Science.gov (United States)

    Springer, Andrea; Fichtel, Claudia; Calvignac-Spencer, Sébastien; Leendertz, Fabian H.; Kappeler, Peter M.

    2015-01-01

    Hemoparasites can cause serious morbidity in humans and animals and often involve wildlife reservoirs. Understanding patterns of hemoparasite infections in natural populations can therefore inform about emerging disease risks, especially in the light of climate change and human disruption of natural ecosystems. We investigated the effects of host age, sex, host group size and season on infection patterns of Plasmodium sp., Babesia sp. and filarial nematodes in a population of wild Malagasy primates, Verreaux's sifakas (Propithecus verreauxi), as well as the effects of these infections on hematological variables. We tested 45 blood samples from 36 individuals and identified two species of Plasmodium, one species of Babesia and two species of filarial nematodes. Plasmodium spp. and Babesia sp. infections showed opposite patterns of age-dependency, with babesiosis being prevalent among young animals, while older animals were infected with Plasmodium sp. In addition, Babesia sp. infection was a statistically significant negative predictor of Plasmodium sp. infection. These results suggest that Plasmodium and Babesia parasites may interact within the host, either through cross-immunity or via resource competition, so that Plasmodium infections can only establish after babesiosis has resolved. We found no effects of host sex, host group size and season on hemoparasite infections. Infections showed high prevalences and did not influence hematological variables. This preliminary evidence supports the impression that the hosts and parasites considered in this study appear to be well-adapted to each other, resulting in persistent infections with low pathogenic and probably low zoonotic potential. Our results illustrate the crucial role of biodiversity in host-parasite relationships, specifically how within-host pathogen diversity may regulate the abundance of parasites. PMID:26767166

  16. Study of metal specific interaction, F-LUMO and VL shift to understand interface of CuPc thin films and noble metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Sumona; Mukherjee, M., E-mail: manabendra.mukherjee@saha.ac.in

    2015-10-30

    Graphical abstract: - Highlights: • F-LUMO, a hybridized state near E{sub F} confirms partial charge transfer. • Non-significant role of partial charge transfer in VL shift over push back effect. • Pyrrole sites affected for partial charge transfer from Cu and Ag substrates. • Negligible effect on pyrrole cites for Pt and Au substrates. - Abstract: The performances of organic electronic devices are significantly associated with their energy level alignment at organic semiconductor/metal–electrode interfaces. The electronic character of an organic semiconducting molecular over-layer on a metal surface can vary from semiconducting to metallic, depending on the nature of the molecular orbitals with respect to the Fermi level of the electrode. The general tendency of extrapolating established models for single crystal substrates to ‘real’ device substrates is highly misleading. Hence, the importance of metal specific interaction, former lowest unoccupied molecular orbital (F-LUMO) and vacuum level (VL) shift have been investigated as a function of thickness of the deposited films by means of photoelectron spectroscopy (XPS and UPS) to understand the interface between CuPc and Cu, Ag, Pt and Au foils sequentially. The XPS data provides the signature of affectability of pyrrole sites of CuPc molecules for partial charge transfer from Cu and Ag substrates while a negligible effect on pyrrole cites resulted for Pt and Au substrates. Furthermore, the appearance of F-LUMO, a hybridized state close to the Fermi level gives confirmatory information about partial charge transfer. Contrary to the general belief that vacuum level shift caused by charge transfer can partially or totally cancel that for push back effect, our observation indicates that the partial charge transfer does not play significant role in the shift of vacuum level. The entire thickness dependent electronic energy level alignment of CuPc films on all noble metal substrates is explained in terms

  17. Study of metal specific interaction, F-LUMO and VL shift to understand interface of CuPc thin films and noble metal surfaces

    International Nuclear Information System (INIS)

    Sinha, Sumona; Mukherjee, M.

    2015-01-01

    Graphical abstract: - Highlights: • F-LUMO, a hybridized state near E_F confirms partial charge transfer. • Non-significant role of partial charge transfer in VL shift over push back effect. • Pyrrole sites affected for partial charge transfer from Cu and Ag substrates. • Negligible effect on pyrrole cites for Pt and Au substrates. - Abstract: The performances of organic electronic devices are significantly associated with their energy level alignment at organic semiconductor/metal–electrode interfaces. The electronic character of an organic semiconducting molecular over-layer on a metal surface can vary from semiconducting to metallic, depending on the nature of the molecular orbitals with respect to the Fermi level of the electrode. The general tendency of extrapolating established models for single crystal substrates to ‘real’ device substrates is highly misleading. Hence, the importance of metal specific interaction, former lowest unoccupied molecular orbital (F-LUMO) and vacuum level (VL) shift have been investigated as a function of thickness of the deposited films by means of photoelectron spectroscopy (XPS and UPS) to understand the interface between CuPc and Cu, Ag, Pt and Au foils sequentially. The XPS data provides the signature of affectability of pyrrole sites of CuPc molecules for partial charge transfer from Cu and Ag substrates while a negligible effect on pyrrole cites resulted for Pt and Au substrates. Furthermore, the appearance of F-LUMO, a hybridized state close to the Fermi level gives confirmatory information about partial charge transfer. Contrary to the general belief that vacuum level shift caused by charge transfer can partially or totally cancel that for push back effect, our observation indicates that the partial charge transfer does not play significant role in the shift of vacuum level. The entire thickness dependent electronic energy level alignment of CuPc films on all noble metal substrates is explained in terms of a

  18. A Model of an Integrated Immune System Pathway in Homo sapiens and Its Interaction with Superantigen Producing Expression Regulatory Pathway in Staphylococcus aureus: Comparing Behavior of Pathogen Perturbed and Unperturbed Pathway

    Science.gov (United States)

    Tomar, Namrata; De, Rajat K.

    2013-01-01

    Response of an immune system to a pathogen attack depends on the balance between the host immune defense and the virulence of the pathogen. Investigation of molecular interactions between the proteins of a host and a pathogen helps in identifying the pathogenic proteins. It is necessary to understand the dynamics of a normally behaved host system to evaluate the capacity of its immune system upon pathogen attack. In this study, we have compared the behavior of an unperturbed and pathogen perturbed host system. Moreover, we have developed a formalism under Flux Balance Analysis (FBA) for the optimization of conflicting objective functions. We have constructed an integrated pathway system, which includes Staphylococcal Superantigen (SAg) expression regulatory pathway and TCR signaling pathway of Homo sapiens. We have implemented the method on this pathway system and observed the behavior of host signaling molecules upon pathogen attack. The entire study has been divided into six different cases, based on the perturbed/unperturbed conditions. In other words, we have investigated unperturbed and pathogen perturbed human TCR signaling pathway, with different combinations of optimization of concentrations of regulatory and signaling molecules. One of these cases has aimed at finding out whether minimization of the toxin production in a pathogen leads to the change in the concentration levels of the proteins coded by TCR signaling pathway genes in the infected host. Based on the computed results, we have hypothesized that the balance between TCR signaling inhibitory and stimulatory molecules can keep TCR signaling system into resting/stimulating state, depending upon the perturbation. The proposed integrated host-pathogen interaction pathway model has accurately reflected the experimental evidences, which we have used for validation purpose. The significance of this kind of investigation lies in revealing the susceptible interaction points that can take back the

  19. Understanding Blood Pressure Readings

    Science.gov (United States)

    ... Venous Thromboembolism Aortic Aneurysm More Understanding Blood Pressure Readings Updated:Jun 1,2018 What do your blood ... and Live Our Interactive Cardiovascular Library has detailed animations and illustrations to help you learn about conditions, ...

  20. Using protein design algorithms to understand the molecular basis of disease caused by protein-DNA interactions: the Pax6 example

    DEFF Research Database (Denmark)

    Alibes, A.; Nadra, A.; De Masi, Federico

    2010-01-01

    diseases such as aniridia. The validity of FoldX to deal with protein-DNA interactions was demonstrated by showing that high levels of accuracy can be achieved for mutations affecting these interactions. Also we showed that protein-design algorithms can accurately reproduce experimental DNA-binding logos......Quite often a single or a combination of protein mutations is linked to specific diseases. However, distinguishing from sequence information which mutations have real effects in the protein's function is not trivial. Protein design tools are commonly used to explain mutations that affect protein...... stability, or protein-protein interaction, but not for mutations that could affect protein-DNA binding. Here, we used the protein design algorithm FoldX to model all known missense mutations in the paired box domain of Pax6, a highly conserved transcription factor involved in eye development and in several...

  1. Understanding plant cell-wall remodelling during the symbiotic interaction between Tuber melanosporum and Corylus avellana using a carbohydrate microarray

    DEFF Research Database (Denmark)

    Sillo, Fabiano; Fangel, Jonatan Ulrik; Henrissat, Bernard

    2016-01-01

    . An important feature of these interactions concerns changes in the cell-wall composition during interaction with other organisms. In ectomycorrhizae, plant and fungal cell walls come into direct contact, and represent the interface between the two partners. However, very little information is available...... on the re-arrangement that could occur within the plant and fungal cell walls during ectomycorrhizal symbiosis. Taking advantage of the Comprehensive Microarray Polymer Profiling (CoMPP) technology, the current study has had the aim of monitoring the changes that take place in the plant cell wall in Corylus...

  2. The interactional management of ‘language difficulties’ at work – L2 strategies for responding to explicit inquiries about understanding

    DEFF Research Database (Denmark)

    Tranekjær, Louise

    2017-01-01

    In multilingual work-place settings, there are many ways of addressing (or not addressing) the issue of understanding, and different ways of handling when the issue is explicitly raised in the form of a question. Building on a previous study by Tranekjær (Tranekjær, 2015; Tranekjær og Kappa, 2016......; 2014) the paper will explore the possibility of outlining differences in the efficiency of SL learner strategies for addressing inquiries about understanding. The paper in this way provides valuable input to language teachers and trainers within the field of diversity management and intercultural...

  3. Enhancing the Reuse of Digital Resources for Integrated Systems to Represent, Understand and Dynamize Complex Interactions in Architectural Cultural Heritage Environments

    Science.gov (United States)

    Delgado, F. J.; Martinez, R.; Finat, J.; Martinez, J.; Puche, J. C.; Finat, F. J.

    2013-07-01

    In this work we develop a multiply interconnected system which involves objects, agents and interactions between them from the use of ICT applied to open repositories, users communities and web services. Our approach is applied to Architectural Cultural Heritage Environments (ACHE). It includes components relative to digital accessibility (to augmented ACHE repositories), contents management (ontologies for the semantic web), semiautomatic recognition (to ease the reuse of materials) and serious videogames (for interaction in urban environments). Their combination provides a support for local real/remote virtual tourism (including some tools for low-level RT display of rendering in portable devices), mobile-based smart interactions (with a special regard to monitored environments) and CH related games (as extended web services). Main contributions to AR models on usual GIS applied to architectural environments, concern to an interactive support performed directly on digital files which allows to access to CH contents which are referred to GIS of urban districts (involving facades, historical or preindustrial buildings) and/or CH repositories in a ludic and transversal way to acquire cognitive, medial and social abilities in collaborative environments.

  4. Affective and behavioral responses to robot-initiated social touch : Towards understanding the opportunities and limitations of physical contact in human-robot interaction

    NARCIS (Netherlands)

    Willemse, C.J.A.M.; Toet, A.; Erp, J.B.F. van

    2017-01-01

    Social touch forms an important aspect of the human non-verbal communication repertoire, but is often overlooked in human–robot interaction. In this study, we investigated whether robot-initiated touches can induce physiological, emotional, and behavioral responses similar to those reported for

  5. “So, it is about how negative it is?!” Understanding researcher/researched interactions as relations between intersectional social positions

    Directory of Open Access Journals (Sweden)

    Sune Qvotrup Jensen

    2012-09-01

    Full Text Available The article argues that interactions in qualitative interviews and ethnography can be analyzed as relations between intersectional social positions. It draws attention to the importance of class and geographical location in such analysis. It further argues that such interactions work through typifications, that they have a power dimension and that they entail processes of identity formation. The identities being offered through these processes can, however, be negotiated or resisted. The article then analyses such interactions as they were experienced in two research projects the author participated in: His PhD project about young marginalized ethnic minority men, and the collective project INTERLOC which focused on the interplay between gender, class, ethnicity and ‘race’ in an underprivileged Danish suburb. It is demonstrated that relationality influences the assumptions research participants have about the researcher. It is also demonstrated that the research encounter entails powerful mechanism of identity formation. The informants, however, sometimes resist these processes resulting in blurred and unstable, sometimes antagonistic, power relations. It is finally argued that analyses of such interactions can provide central insight into the subject studied.

  6. How Do Pre-Service Teachers Picture Various Electromagnetic Phenomenon? A Qualitative Study of Pre-Service Teachers' Conceptual Understanding of Fundamental Electromagnetic Interaction

    Science.gov (United States)

    Beer, Christopher P.

    2010-01-01

    This study analyzes the nature of pre-service teachers' conceptual models of various electromagnetic phenomena, specifically electrical current, electrical resistance, and light/matter interactions. This is achieved through the students answering the three questions on electromagnetism using a free response approach including both verbal and…

  7. Affective and Behavioral Responses to Robot-Initiated Social Touch : Toward Understanding the Opportunities and Limitations of Physical Contact in Human–Robot Interaction

    NARCIS (Netherlands)

    Willemse, Christian J. A. M.; Toet, Alexander; van Erp, Jan B. F.

    2017-01-01

    Social touch forms an important aspect of the human non-verbal communication repertoire, but is often overlooked in human-robot interaction. In this study, we investigated whether robot-initiated touches can induce physiological, emotional, and behavioral responses similar to those reported for

  8. A review of our understanding of the aerosol-cloud interaction from the perspective of a bin resolved cloud scale modelling

    Science.gov (United States)

    Flossmann, Andrea I.; Wobrock, Wolfram

    2010-09-01

    This review compiles the main results obtained using a mesoscale cloud model with bin resolved cloud micophysics and aerosol particle scavenging, as developed by our group over the years and applied to the simulation of shallow and deep convective clouds. The main features of the model are reviewed in different dynamical frameworks covering parcel model dynamics, as well as 1.5D, 2D and 3D dynamics. The main findings are summarized to yield a digested presentation which completes the general understanding of cloud-aerosol interaction, as currently available from textbook knowledge. Furthermore, it should provide support for general cloud model development, as it will suggest potentially minor processes that might be neglected with respect to more important ones and can support development of parameterizations for air quality, chemical transport and climate models. Our work has shown that in order to analyse dedicated campaign results, the supersaturation field and the complex dynamics of the specific clouds needs to be reproduced. Only 3D dynamics represents the variation of the supersaturation over the entire cloud, the continuous nucleation and deactivation of hydrometeors, and the dependence upon initial particle size distribution and solubility. However, general statements on certain processes can be obtained also by simpler dynamics. In particular, we found: Nucleation incorporates about 90% of the initial aerosol particle mass inside the cloud drops. Collision and coalescence redistributes the scavenged aerosol particle mass in such a way that the particle mass follows the main water mass. Small drops are more polluted than larger ones, as pollutant mass mixing ratio decreases with drops size. Collision and coalescence mixes the chemical composition of the generated drops. Their complete evaporation will release processed particles that are mostly larger and more hygroscopic than the initial particles. An interstitial aerosol is left unactivated between the

  9. Understanding the controls on sediment-P interactions and dynamics along a non-tidal river system in a rural–urban catchment: The River Nene

    International Nuclear Information System (INIS)

    Tye, A.M.; Rawlins, B.G.; Rushton, J.C.; Price, R.

    2016-01-01

    The release of Phosphorus (P) from river sediments has been identified as a contributing factor to waters failing the criteria for ‘Good Ecological Status’ under the EU Water Framework Directive (WFD). To identify the contribution of sediment-P to river systems, an understanding of the factors that influence its distribution within the entire non-tidal system is required. Thus the aims of this work were to examine the (i) total (P_T_o_t_a_l) and labile (P_L_a_b_i_l_e) concentrations in sediment, (ii) the sequestration processes and (iii) the interactions between sediment P and the river water in the six non-tidal water bodies of the River Nene, U.K. Collection of sediments followed a long period of flooding and high stream flow. In each water body, five cores were extracted and homogenised for analysis with an additional core being taken and sampled by depth increments. Comparing the distribution of sediment particle size and P_T_o_t_a_l data with soil catchment geochemical survey data, large increases in P_T_o_t_a_l were identified in sediments from water body 4–6, where median concentrations of P_T_o_t_a_l in the sediment (3603 mg kg"−"1) were up to double those of the catchment soils. A large proportion of this increase may be related to in-stream sorption of P, particularly from sewage treatment facilities where the catchment becomes more urbanised after water body 3. A linear correlation (r = 0.8) between soluble reactive phosphate (SRP) and Boron in the sampled river waters was found suggesting increased STW input in water bodies 4–6. P_L_a_b_i_l_e concentrations in homogenised cores were up to 100 mg kg"−"1 PO_4–P (generally < 2% of P_T_o_t_a_l) and showed a general increase with distance from the headwaters. A general increase in Equilibrium Phosphate Concentrations (EPC_0) from an average of 0.9–∼1.7 μm L"−"1 was found between water bodies 1–3 and 4–6. Fixation within oxalate extractable phases (Al, Fe and Mn) accounted

  10. Interaction of amines with native aluminium oxide layers in non-aqueous environment: Application to the understanding of the formation of epoxy-amine/metal interphases

    International Nuclear Information System (INIS)

    Mercier, D.; Rouchaud, J.-C.; Barthes-Labrousse, M.-G.

    2008-01-01

    Interaction of propylamine (PA), 1,2-diaminoethane (DAE) or 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophorone diamine, IPDA) with native aluminium oxide layers in non-aqueous environment has been studied using time-resolved inductively coupled plasma optical emission spectroscopy (ICP-OES) and X-ray photoelectron spectroscopy (XPS). The formation of several surface complexes has been evidenced. Monodentate and bidentate metal-bond surface complexes (MBSC) result from interactions between the amine terminations of the molecule and aluminium cations by donation of the N lone electron pair to the metal ion (Lewis-like mechanism leading to O-Al...N bonds). Monodentate and bidentate hydrogen-bond surface complexes (HBSC) are due to interaction of the amino group with surface hydroxyl groups by protonation of the amine termination (Bronsted-like mechanism leading to the formation of Al-OH...N bonds) or interaction with carbonaceous contamination (C x O y H z ...N bonds). Diamines can also form mixed complexes with one amino group forming an O-Al...N bond and the other group forming an Al-OH...N or C x O y H z ...N bond. Al-OH...N and C x O y H z ...N bonds are less stable under vacuum than O-Al...N bonds, leading to partial desorption of the DAE molecules in vacuum and modification of the interaction modes. Only DAE and IPDA can lead to partial dissolution of the aluminium native (hydr)oxide films. A detailed mechanism of dissolution has been proposed based on the formation of mononuclear bidentate (chelate) MBSC by ligand exchange between the terminal η 1 -OH and bridged μ 2 -OH surface sites and the amino terminations of the molecule. The detachment of this complex from the surface is likely to be the precursor step to the formation of the interphase in epoxy-amine/metal systems

  11. A reassessment of the potential for an alpha-mode containment failure and a review of the current understanding of broader fuel-coolant interaction issues. Second steam explosion review group workshop

    Energy Technology Data Exchange (ETDEWEB)

    Basu, S. [Nuclear Regulatory Commission, Washington, DC (United States); Ginsberg, T. [Brookhaven National Lab., Upton, NY (United States)

    1996-08-01

    This report summarizes the review and evaluation by experts of the current understanding of the molten fuel-coolant interaction (FCI) issues covering the complete spectrum of interactions, i.e., from mild quenching to very energetic interactions including those that could lead to the alpha-mode containment failure. Of the eleven experts polled, all but two concluded that the alpha-mode failure issue was resolved from a risk perspective, meaning that this mode of failure is of very low probability, that it is of little or no significance to the overall risk from a nuclear power plant, and that any further reduction in residual uncertainties is not likely to change the probability in an appreciable manner. To a lesser degree, discussions also took place on the broader FCI issues such as mild quenching of core melt during non-explosive FCI, and shock loading of lower head and ex-vessel support structures arising from explosive localized FCIs. These latter issues are relevant with regard to determining the efficacy of certain accident management strategies for operating reactors as well as for advanced light water reactors. The experts reviewed the status of understanding of the FCI phenomena in the context of these broader issues, identified residual uncertainties in the understanding, and recommended future research (both experimental and analytical) to reduce the uncertainties.

  12. A reassessment of the potential for an alpha-mode containment failure and a review of the current understanding of broader fuel-coolant interaction issues. Second steam explosion review group workshop

    International Nuclear Information System (INIS)

    Basu, S.; Ginsberg, T.

    1996-08-01

    This report summarizes the review and evaluation by experts of the current understanding of the molten fuel-coolant interaction (FCI) issues covering the complete spectrum of interactions, i.e., from mild quenching to very energetic interactions including those that could lead to the alpha-mode containment failure. Of the eleven experts polled, all but two concluded that the alpha-mode failure issue was resolved from a risk perspective, meaning that this mode of failure is of very low probability, that it is of little or no significance to the overall risk from a nuclear power plant, and that any further reduction in residual uncertainties is not likely to change the probability in an appreciable manner. To a lesser degree, discussions also took place on the broader FCI issues such as mild quenching of core melt during non-explosive FCI, and shock loading of lower head and ex-vessel support structures arising from explosive localized FCIs. These latter issues are relevant with regard to determining the efficacy of certain accident management strategies for operating reactors as well as for advanced light water reactors. The experts reviewed the status of understanding of the FCI phenomena in the context of these broader issues, identified residual uncertainties in the understanding, and recommended future research (both experimental and analytical) to reduce the uncertainties

  13. Serish inulin and wheat biopolymers interactions in model systems as a basis for understanding the impact of inulin on bread properties: a FTIR investigation.

    Science.gov (United States)

    Pourfarzad, Amir; Habibi Najafi, Mohammad B; Haddad Khodaparast, Mohammad H; Khayyat, Mohammad Hassanzadeh

    2015-12-01

    In this study the interactions between Serish root inulin and the main biopolymer types of wheat flour namely gluten, starch and phospholipid, were investigated in different model systems using Fourier transform infrared (FTIR) spectroscopy to unravel the underlying physical mechanism by which inulin impacts dough and bread properties. Interactions of inulin with starch and phospholipid were not considerable compared to gluten, but it was also clear that the modes of these interactions varied with the type and the amount of additives used in model formulation. This study revealed that when inulin is added to gluten, water redistribution promotes partial dehydration of gluten and collapse of β-spirals into intermolecular β-sheet structures; this trans-conformations might be due to physical reasons are believed to further impact the poor quality of bread containing added inulin. Upon performing Gaussian-Lorenzian curve fitting, it was observed that by adding of inulin to model systems, the relative contribution of characteristic peaks of β-turn and intramolecular β-sheet was progressively decreased whereas intermolecular β-sheet and α-helix contents were increased.

  14. Understanding the Selectivity Mechanism of the Human Asialoglycoprotein Receptor (ASGP-R toward Gal- and Man- type Ligands for Predicting Interactions with Exogenous Sugars

    Directory of Open Access Journals (Sweden)

    Emo Chiellini

    2007-01-01

    Full Text Available A practical approach for addressing the computer simulation of protein-carbohydrate interactions is described here. An articulated computational protocol was setup and validated by checking its ability to predict experimental data, available in theliterature, and concerning the selectivity shown by the Carbohydrate Recognition Domain(CRD of the human asialoglycoprotein receptor (ASGP-R toward Gal-type ligands. Somerequired features responsible for the interactions were identified. Subsequently the sameprotocol was applied to monomer sugar molecules that constitute the building blocks foralginates and ulvans. Such sugar polymers may supply a low-cost source of rare sugars witha potential impact on several industrial applications, from pharmaceutical to fine chemicalindustry. An example of their applicative exploitation could be given by their use indeveloping biomaterial with adhesion properties toward hepatocytes, through interactionwith the ASGP-R. Such a receptor has been already proposed as a target for exogenousmolecules, specifically in the case of hepatocytes, for diagnostic and therapeutic purposes.The DOCK5.2 program was used to search optimal locations of the above ligands of interestinto CRD binding site and to roughly estimate interaction energies. Finally, the binding ∆G oftheoretical protein-ligand complexes was estimated by using the DelPhi program in which thesolvation free energy is accounted for with a continuum solvent model, by solving the Poisson-Boltzmann equation. The structure analysis of the obtained complexes and their ∆G values suggest that one of the sugar monomers of interest shows the desired characteristics.

  15. A real-time spoken-language system for interactive problem-solving, combining linguistic and statistical technology for improved spoken language understanding

    Science.gov (United States)

    Moore, Robert C.; Cohen, Michael H.

    1993-09-01

    Under this effort, SRI has developed spoken-language technology for interactive problem solving, featuring real-time performance for up to several thousand word vocabularies, high semantic accuracy, habitability within the domain, and robustness to many sources of variability. Although the technology is suitable for many applications, efforts to date have focused on developing an Air Travel Information System (ATIS) prototype application. SRI's ATIS system has been evaluated in four ARPA benchmark evaluations, and has consistently been at or near the top in performance. These achievements are the result of SRI's technical progress in speech recognition, natural-language processing, and speech and natural-language integration.

  16. Development of an integrated model for the Campaspe catchment: a tool to help improve understanding of the interaction between society, policy, farming decision, ecology, hydrology and climate

    Science.gov (United States)

    Iwanaga, Takuya; Zare, Fateme; Croke, Barry; Fu, Baihua; Merritt, Wendy; Partington, Daniel; Ticehurst, Jenifer; Jakeman, Anthony

    2018-06-01

    Management of water resources requires understanding of the hydrology and hydrogeology, as well as the policy and human drivers and their impacts. This understanding requires relevant inputs from a wide range of disciplines, which will vary depending on the specific case study. One approach to gain understanding of the impact of climate and society on water resources is through the use of an integrated modelling process that engages stakeholders and experts in specifics of problem framing, co-design of the underpinning conceptual model, and discussion of the ensuing results. In this study, we have developed such an integrated modelling process for the Campaspe basin in northern Victoria, Australia. The numerical model built has a number of components: - Node/link based surface water hydrology module based on the IHACRES rainfall-streamflow model - Distributed groundwater model for the lower catchment (MODFLOW) - Farm decision optimisation module (to determine irrigation requirements) - Policy module (setting conditions on availability of water based on existing rules) - Ecology module (determining the impacts of available streamflow on platypus, fish and river red gum trees) The integrated model is component based and has been developed in Python, with the MODFLOW and surface water hydrology model run in external programs, controlled by the master program (in Python). The integrated model has been calibrated using historical data, with the intention of exploring the impact of various scenarios (future climate scenarios, different policy options, water management options) on the water resources. The scenarios were selected based on workshops with, and a social survey of, stakeholders in the basin regarding what would be socially acceptable and physically plausible options for changes in management. An example of such a change is the introduction of a managed aquifer recharge system to capture dam overflows, and store at least a portion of this in the aquifer

  17. Understanding the adsorptive interactions of arsenate-iron nanoparticles with curved fullerene-like sheets in activated carbon using a quantum mechanics/molecular mechanics computational approach.

    Science.gov (United States)

    Ha, Nguyen Ngoc; Cam, Le Minh; Ha, Nguyen Thi Thu; Goh, Bee-Min; Saunders, Martin; Jiang, Zhong-Tao; Altarawneh, Mohammednoor; Dlugogorski, Bogdan Z; El-Harbawi, Mohanad; Yin, Chun-Yang

    2017-06-07

    The prevalence of global arsenic groundwater contamination has driven widespread research on developing effective treatment systems including adsorption using various sorbents. The uptake of arsenic-based contaminants onto established sorbents such as activated carbon (AC) can be effectively enhanced via immobilization/impregnation of iron-based elements on the porous AC surface. Recent suggestions that AC pores structurally consist of an eclectic mix of curved fullerene-like sheets may affect the arsenic adsorption dynamics within the AC pores and is further complicated by the presence of nano-sized iron-based elements. We have therefore, attempted to shed light on the adsorptive interactions of arsenate-iron nanoparticles with curved fullerene-like sheets by using hybridized quantum mechanics/molecular mechanics (QMMM) calculations and microscopy characterization. It is found that, subsequent to optimization, chemisorption between HAsO 4 2- and the AC carbon sheet (endothermic process) is virtually non-existent - this observation is supported by experimental results. Conversely, the incorporation of iron nanoparticles (FeNPs) into the AC carbon sheet greatly facilitates chemisorption of HAsO 4 2- . Our calculation implies that iron carbide is formed at the junction between the iron and the AC interface and this tightly chemosorbed layer prevents detachment of the FeNPs on the AC surface. Other aspects including electronic structure/properties, carbon arrangement defects and rate of adsorptive interaction, which are determined using the Climbing-Image NEB method, are also discussed.

  18. The interaction of R&D and market orientation in improving business performance: An empirically based framework for understanding what drives innovation activity

    DEFF Research Database (Denmark)

    Grunert, Klaus G.; Harmsen, Hanne

    1997-01-01

    The interplay between R&D skills and competencies and market skills and competencies is in the more recent product development literature seen as a major determinant of successful innovation. The study reported in this paper was done in order to c more light on these two constructs in a tradition......The interplay between R&D skills and competencies and market skills and competencies is in the more recent product development literature seen as a major determinant of successful innovation. The study reported in this paper was done in order to c more light on these two constructs...... in a traditionally low-tech industry, where product development is nevertheless considered to be strategically important, i.e., the food processing industry. The results of a series of case studies indicate that constructs than R&D and market orientation may be more appropriate for understanding innovation...

  19. Understanding the perceptions, roles and interactions of stakeholder networks managing health-care waste: A case study of the Gaza Strip.

    Science.gov (United States)

    Caniato, M; Tudor, T; Vaccari, M

    2015-01-01

    The sustainable management of waste requires a holistic approach involving a range of stakeholders. What can often be difficult is to understand the manner in which different types of stakeholder networks are composed and work, and how best to enhance their effectiveness. Using social network analysis and stakeholder analysis of healthcare waste management stakeholders in the case study region of the Gaza Strip, this study aimed to understand and examine the manner in which the networks functioned. The Ministry of Health was found to be the most important stakeholder, followed by municipalities and solid waste management councils. Some international agencies were also mentioned, with specific roles, while other local institutions had a limited influence. Finally while health-care facilities had a strong interest in waste management, they were generally poorly informed and had limited links to each other. The manner in which the networks operated was complicated and influenced by differences in perception, sharing of information, access to finance and levels of awareness. The lack of a clear legal framework generated various mistakes about roles and responsibilities in the system, and evidently regulation was not an effective driver for improvement. Finally stakeholders had different priorities according to the waste management issues they were involved with, however segregation at the source was identified as a key requirement by most. Areas for improving the effectiveness of the networks are suggested. The analysis utilized an innovative methodology, which involved a large number of stakeholders. Such an approach served to raise interest and awareness at different levels (public authorities, health providers, supporting actors, others), stimulate the discussion about the adoption of specific policies, and identify the effective way forward. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Understanding the perceptions, roles and interactions of stakeholder networks managing health-care waste: A case study of the Gaza Strip

    International Nuclear Information System (INIS)

    Caniato, M.; Tudor, T.; Vaccari, M.

    2015-01-01

    Highlights: • We systematically review scientific literature about health-care waste management. • We identify and discuss gaps, trends, efforts, and key-factors. • We suggest areas for improvement and best practices reported in literature. • We include recommendations for policy makers, practitioners and researchers. • We promote a holistic and harmonized approach to health-care waste management. - Abstract: The sustainable management of waste requires a holistic approach involving a range of stakeholders. What can often be difficult is to understand the manner in which different types of stakeholder networks are composed and work, and how best to enhance their effectiveness. Using social network analysis and stakeholder analysis of healthcare waste management stakeholders in the case study region of the Gaza Strip, this study aimed to understand and examine the manner in which the networks functioned. The Ministry of Health was found to be the most important stakeholder, followed by municipalities and solid waste management councils. Some international agencies were also mentioned, with specific roles, while other local institutions had a limited influence. Finally while health-care facilities had a strong interest in waste management, they were generally poorly informed and had limited links to each other. The manner in which the networks operated was complicated and influenced by differences in perception, sharing of information, access to finance and levels of awareness. The lack of a clear legal framework generated various mistakes about roles and responsibilities in the system, and evidently regulation was not an effective driver for improvement. Finally stakeholders had different priorities according to the waste management issues they were involved with, however segregation at the source was identified as a key requirement by most. Areas for improving the effectiveness of the networks are suggested. The analysis utilized an innovative methodology

  1. Understanding the perceptions, roles and interactions of stakeholder networks managing health-care waste: A case study of the Gaza Strip

    Energy Technology Data Exchange (ETDEWEB)

    Caniato, M., E-mail: marcocaniato@gmail.com [Research Centre on Appropriate Technologies for Environmental Management in Developing Countries (CeTAmb), University of Brescia, Brescia (Italy); Tudor, T. [Centre for Sustainable Waste Management, School of Science and Technology, University of Northampton, Northampton (United Kingdom); Vaccari, M. [Research Centre on Appropriate Technologies for Environmental Management in Developing Countries (CeTAmb), University of Brescia, Brescia (Italy)

    2015-01-15

    Highlights: • We systematically review scientific literature about health-care waste management. • We identify and discuss gaps, trends, efforts, and key-factors. • We suggest areas for improvement and best practices reported in literature. • We include recommendations for policy makers, practitioners and researchers. • We promote a holistic and harmonized approach to health-care waste management. - Abstract: The sustainable management of waste requires a holistic approach involving a range of stakeholders. What can often be difficult is to understand the manner in which different types of stakeholder networks are composed and work, and how best to enhance their effectiveness. Using social network analysis and stakeholder analysis of healthcare waste management stakeholders in the case study region of the Gaza Strip, this study aimed to understand and examine the manner in which the networks functioned. The Ministry of Health was found to be the most important stakeholder, followed by municipalities and solid waste management councils. Some international agencies were also mentioned, with specific roles, while other local institutions had a limited influence. Finally while health-care facilities had a strong interest in waste management, they were generally poorly informed and had limited links to each other. The manner in which the networks operated was complicated and influenced by differences in perception, sharing of information, access to finance and levels of awareness. The lack of a clear legal framework generated various mistakes about roles and responsibilities in the system, and evidently regulation was not an effective driver for improvement. Finally stakeholders had different priorities according to the waste management issues they were involved with, however segregation at the source was identified as a key requirement by most. Areas for improving the effectiveness of the networks are suggested. The analysis utilized an innovative methodology

  2. Engineering Defect-Free Nanoporous Pd from Optimized Pd-Ni Precursor Alloy by Understanding Palladium-Hydrogen Interactions During Dealloying

    Science.gov (United States)

    Schoop, Julius; Balk, T. John

    2014-04-01

    Thin films of nanoporous palladium (np-Pd) were produced from binary palladium-nickel (Pd-Ni) precursor alloys. A suitable precursor alloy and a method of dealloying to yield optimum nanoporosity (average pore/ligament size of 7 nm) were developed by studying the effects of various processing parameters on final microstructure. To obtain crack-free np-Pd, a 100 nm thin film of 20 at. pct Pd (80 at. pct Ni) can be dealloyed for ~5 hours in a 1 M solution of sulfuric acid, with oleic acid and oleylamine added as surfactants. Both shorter and longer dealloying times, as well as heating, inhibit the formation of crack-free np-Pd. Stress measurements at different stages of dealloying revealed that the necessary dealloying time is determined by the diffusion-controlled corrosion reaction occurring within the thin film during dealloying. Strong interaction between hydrogen and np-Pd was reflected in the stress evolution during dealloying. A mechanism is proposed for the formation of a Ni-rich dense top layer that results from H-induced swelling during initial dealloying and permits the development of defect-free np-Pd beneath, by limiting the speed of dealloying.

  3. A review of recent theoretical developments in the understanding of the migration of helium in metals and its interaction with lattice defects

    International Nuclear Information System (INIS)

    Reed, D.J.

    1977-01-01

    Recent theoretical calculations of the properties of rare gases, and in particular helium, in the common f.c.c. and b.c.c. metals, are reviewed from the viewpoint of the investigator concerned with the behaviour of rare gas in such radiation damage processes as surface blistering and void swelling. Particular attention is paid to mechanisms by which helium may migrate in a damaged metal lattice during irradiation and to the properties of small gas and vacancy clusters which may represent bubble or void nuclei. Initially the proposed rapid migration of interstitial helium is discussed together with the substitutional de-trapping mechanism, whereby thermally activated helium jumps from a substitutional to an interstitial position. This enables a mechanism of substitutional helium diffusion to be proposed which may proceed at temperatures below those of self-diffusion. The formation, binding, migration and dissociation energies of gas-vacancy clusters have been reviewed. The relevance of the predicted trend towards the optimum stability of clusters composed of equal numbers of gas atoms and vacancies is discussed. The limited data available concerned with the binding of a helium atom to a pure dislocation line is presented together with comments on the possible nature of the interaction of helium with the dislocation jog. (author)

  4. Sphagnum physiology in the context of changing climate: emergent influences of genomics, modelling and host-microbiome interactions on understanding ecosystem function.

    Science.gov (United States)

    Weston, David J; Timm, Collin M; Walker, Anthony P; Gu, Lianhong; Muchero, Wellington; Schmutz, Jeremy; Shaw, A Jonathan; Tuskan, Gerald A; Warren, Jeffrey M; Wullschleger, Stan D

    2015-09-01

    Peatlands harbour more than one-third of terrestrial carbon leading to the argument that the bryophytes, as major components of peatland ecosystems, store more organic carbon in soils than any other collective plant taxa. Plants of the genus Sphagnum are important components of peatland ecosystems and are potentially vulnerable to changing climatic conditions. However, the response of Sphagnum to rising temperatures, elevated CO2 and shifts in local hydrology have yet to be fully characterized. In this review, we examine Sphagnum biology and ecology and explore the role of this group of keystone species and its associated microbiome in carbon and nitrogen cycling using literature review and model simulations. Several issues are highlighted including the consequences of a variable environment on plant-microbiome interactions, uncertainty associated with CO2 diffusion resistances and the relationship between fixed N and that partitioned to the photosynthetic apparatus. We note that the Sphagnum fallax genome is currently being sequenced and outline potential applications of population-level genomics and corresponding plant photosynthesis and microbial metabolic modelling techniques. We highlight Sphagnum as a model organism to explore ecosystem response to a changing climate and to define the role that Sphagnum can play at the intersection of physiology, genetics and functional genomics. © 2014 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

  5. Understanding of CO{sub 2} interaction with thermally grown SiO{sub 2} on Si using IBA depth profiling techniques

    Energy Technology Data Exchange (ETDEWEB)

    Deokar, Geetanjali; D’Angelo, Marie; Briand, Emrick [INSP, UPMC, CNRS UMR 7588, 4 Place Jussieu, Paris F-75005 (France); Deville Cavellin, Catherine, E-mail: deville@univ-paris12.fr [INSP, UPMC, CNRS UMR 7588, 4 Place Jussieu, Paris F-75005 (France); Faculté des Sciences et Technologie UPEC, 61 Av., De Gaulle, Créteil F-94010 (France)

    2013-06-01

    Interactions between CO{sub 2} and SiO{sub 2} films thermally grown on Si have been studied using {sup 18}O and {sup 13}C as isotopic tracers associated with ion beam analysis (IBA) depth profiling techniques. From secondary ion mass spectrometry (SIMS) measurements no carbon from CO{sub 2} is detected in the silica while it is found in Si. These results suggest that CO{sub 2} diffuses through the silica. Exchanges of oxygen between CO{sub 2} and silica can be observed from {sup 18}O to {sup 16}O SIMS signals variation. The oxygen concentration depth profiles were determined quantitatively using the narrow resonance near 151 keV in the {sup 18}O(p,α){sup 15}N nuclear reaction (Narrow Resonance Profiling, NRP). We demonstrate that two distinct oxygen exchanges processes co-exist and we determine the diffusion coefficient of the CO{sub 2} molecule in the silica at 1100 °C.

  6. Understanding the land-atmospheric interaction in drought forecast from CFSv2 for the 2011 Texas and 2012 Upper Midwest US droughts

    Science.gov (United States)

    Zhang, Y.; Roundy, J. K.; Ek, M. B.; Wood, E. F.

    2015-12-01

    Prediction and thus preparedness in advance of hydrological extremes, such as drought and flood events, is crucial for proactively reducing their social and economic impacts. In the summers of 2011 Texas, and 2012 the Upper Midwest, experienced intense droughts that affected crops and the food market in the US. It is expected that seasonal forecasts with sufficient skill would reduce the negative impacts through planning and preparation. However, the forecast skill from models such as Climate Forecast System Version 2 (CFSv2) from National Centers for Environmental Prediction (NCEP) is low over the US, especially during the warm season (Jun - Sep), which restricts their practical use for drought prediction. This study analyzes the processes that lead to premature termination of 2011 and 2012 US summer droughts in CFSv2 forecast resulting in its low forecast skill. Using the North American Land Data Assimilation System version 2 (NLDAS2) and Climate Forecast System Reanalysis (CFSR) as references, this study investigates the forecast skills of CFSv2 initialized at 00, 06, 12, 18z from May 15 - 31 (leads out to September) for each event in terms of land-atmosphere interaction, through a recently developed Coupling Drought Index (CDI), which is based on the Convective Triggering Potential-Humidity Index-soil moisture (CTP-HI-SM) classification of four climate regimes: wet coupling, dry coupling, transitional and atmospherically controlled. A recycling model is used to trace the moisture sources in the CFSv2 forecasts of anomalous precipitation, which lead to the breakdown of drought conditions and a lack of drought forecasting skills. This is then compared with tracing the moisture source in CFSR with the same recycling model, which is used as the verification for the same periods. This helps to identify the parameterization that triggered precipitation in CFSv2 during 2011 and 2012 summer in the US thus has the potential to improve the forecast skill of CSFv2.

  7. Streaming Potential Modeling to Understand the Identification of Hydraulically Active Fractures and Fracture-Matrix Fluid Interactions Using the Self-Potential Method

    Science.gov (United States)

    Jougnot, D.; Roubinet, D.; Linde, N.; Irving, J.

    2016-12-01

    Quantifying fluid flow in fractured media is a critical challenge in a wide variety of research fields and applications. To this end, geophysics offers a variety of tools that can provide important information on subsurface physical properties in a noninvasive manner. Most geophysical techniques infer fluid flow by data or model differencing in time or space (i.e., they are not directly sensitive to flow occurring at the time of the measurements). An exception is the self-potential (SP) method. When water flows in the subsurface, an excess of charge in the pore water that counterbalances electric charges at the mineral-pore water interface gives rise to a streaming current and an associated streaming potential. The latter can be measured with the SP technique, meaning that the method is directly sensitive to fluid flow. Whereas numerous field experiments suggest that the SP method may allow for the detection of hydraulically active fractures, suitable tools for numerically modeling streaming potentials in fractured media do not exist. Here, we present a highly efficient two-dimensional discrete-dual-porosity approach for solving the fluid-flow and associated self-potential problems in fractured domains. Our approach is specifically designed for complex fracture networks that cannot be investigated using standard numerical methods due to computational limitations. We then simulate SP signals associated with pumping conditions for a number of examples to show that (i) accounting for matrix fluid flow is essential for accurate SP modeling and (ii) the sensitivity of SP to hydraulically active fractures is intimately linked with fracture-matrix fluid interactions. This implies that fractures associated with strong SP amplitudes are likely to be hydraulically conductive, attracting fluid flow from the surrounding matrix.

  8. Understanding the plant-microbe interaction molecular mechanisms for better exploitation of bio-control agents to enhance sustainable agricultural practices

    Directory of Open Access Journals (Sweden)

    Indu Kumari

    2017-10-01

    Full Text Available Trichoderma spp. are well-known bio-control agents which promote the plant growth and suppress the pathogen infection. The beneficial effects are attributed to the production of phytohormones, antibiotics, siderophores and secondary metabolites (SM. Trichodermin and Harzianum A, SMs have documented anti-fungal activities as well. Tri5 gene encodes for trichodiene synthase (TS contains a terpene fold and involved at the initial step of the biosynthetic pathway of these molecules. Furthermore, domain analysis of proteins from diverse organisms showed that the terpene fold has functional diversity with diverse applications in agriculture, medicine and applied biotechnology. These proteins can be classified into single and multi-domains based on their structures. It was observed that multi-domain proteins carry additional helices which may regulate the catalytic efficiency. Further, activity enhancing mutations with potentially higher catalytic activities were screened. In an offshoot to the above work, we have analyzed binding of Trichodermin with the 25S rRNA that constitutes the petidyltransferase centre (PTC. The trichodermin resistance protein (60S ribosomal protein L3 was reported to overcome the inhibitory effects of trichothecene compounds. Normal mode analysis and MD of trichodermin resistance protein and 25S consisting of PTC showed that the W-finger region of the protein may move towards 25S rRNA and may block the binding pocket of the trichodermin. These results may lead to develop strategies for higher TS activity and the mechanism of action of these molecules involved in plant-microbe interactions. These may be further exploited for enhancing the efficiency of these biotechnological agents used in sustainable agriculture.