WorldWideScience

Sample records for factors influence host

  1. Host factors influencing viral persistence

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Nansen, A; Ørding Andreasen, Susanne

    2000-01-01

    host were used. Our results reveal that very different outcomes may be observed depending on virus strain and immunocompetence of the host. Thus while CD4+ cells are not critical during the initial phase of virus control, infectious virus reappear in mice lacking CD4+ cells, B cells or CD40 ligand...... that these different outcomes may be explained in relatively simple mathematical terms. This suggests that modelling may be used as a means to predict critical host and virus parameters. Therefore, combining mathematical modelling with precise, quantitative, in vivo analyses looks to be a promising approach...

  2. A Trematode Parasite Derived Growth Factor Binds and Exerts Influences on Host Immune Functions via Host Cytokine Receptor Complexes

    Science.gov (United States)

    Sulaiman, Azad A.; Zolnierczyk, Katarzyna; Japa, Ornampai; Owen, Jonathan P.; Maddison, Ben C.; Hodgkinson, Jane E.; Gough, Kevin C.

    2016-01-01

    The trematode Fasciola hepatica is responsible for chronic zoonotic infection globally. Despite causing a potent T-helper 2 response, it is believed that potent immunomodulation is responsible for rendering this host reactive non-protective host response thereby allowing the parasite to remain long-lived. We have previously identified a growth factor, FhTLM, belonging to the TGF superfamily can have developmental effects on the parasite. Herein we demonstrate that FhTLM can exert influence over host immune functions in a host receptor specific fashion. FhTLM can bind to receptor members of the Transforming Growth Factor (TGF) superfamily, with a greater affinity for TGF-β RII. Upon ligation FhTLM initiates the Smad2/3 pathway resulting in phenotypic changes in both fibroblasts and macrophages. The formation of fibroblast CFUs is reduced when cells are cultured with FhTLM, as a result of TGF-β RI kinase activity. In parallel the wound closure response of fibroblasts is also delayed in the presence of FhTLM. When stimulated with FhTLM blood monocyte derived macrophages adopt an alternative or regulatory phenotype. They express high levels interleukin (IL)-10 and arginase-1 while displaying low levels of IL-12 and nitric oxide. Moreover they also undergo significant upregulation of the inhibitory receptor PD-L1 and the mannose receptor. Use of RNAi demonstrates that this effect is dependent on TGF-β RII and mRNA knock-down leads to a loss of IL-10 and PD-L1. Finally, we demonstrate that FhTLM aids newly excysted juveniles (NEJs) in their evasion of antibody-dependent cell cytotoxicity (ADCC) by reducing the NO response of macrophages—again dependent on TGF-β RI kinase. FhTLM displays restricted expression to the F. hepatica gut resident NEJ stages. The altered fibroblast responses would suggest a role for dampened tissue repair responses in facilitating parasite migration. Furthermore, the adoption of a regulatory macrophage phenotype would allow for a reduced

  3. A Trematode Parasite Derived Growth Factor Binds and Exerts Influences on Host Immune Functions via Host Cytokine Receptor Complexes.

    Directory of Open Access Journals (Sweden)

    Azad A Sulaiman

    2016-11-01

    Full Text Available The trematode Fasciola hepatica is responsible for chronic zoonotic infection globally. Despite causing a potent T-helper 2 response, it is believed that potent immunomodulation is responsible for rendering this host reactive non-protective host response thereby allowing the parasite to remain long-lived. We have previously identified a growth factor, FhTLM, belonging to the TGF superfamily can have developmental effects on the parasite. Herein we demonstrate that FhTLM can exert influence over host immune functions in a host receptor specific fashion. FhTLM can bind to receptor members of the Transforming Growth Factor (TGF superfamily, with a greater affinity for TGF-β RII. Upon ligation FhTLM initiates the Smad2/3 pathway resulting in phenotypic changes in both fibroblasts and macrophages. The formation of fibroblast CFUs is reduced when cells are cultured with FhTLM, as a result of TGF-β RI kinase activity. In parallel the wound closure response of fibroblasts is also delayed in the presence of FhTLM. When stimulated with FhTLM blood monocyte derived macrophages adopt an alternative or regulatory phenotype. They express high levels interleukin (IL-10 and arginase-1 while displaying low levels of IL-12 and nitric oxide. Moreover they also undergo significant upregulation of the inhibitory receptor PD-L1 and the mannose receptor. Use of RNAi demonstrates that this effect is dependent on TGF-β RII and mRNA knock-down leads to a loss of IL-10 and PD-L1. Finally, we demonstrate that FhTLM aids newly excysted juveniles (NEJs in their evasion of antibody-dependent cell cytotoxicity (ADCC by reducing the NO response of macrophages-again dependent on TGF-β RI kinase. FhTLM displays restricted expression to the F. hepatica gut resident NEJ stages. The altered fibroblast responses would suggest a role for dampened tissue repair responses in facilitating parasite migration. Furthermore, the adoption of a regulatory macrophage phenotype would allow

  4. Influence of host factors and parasite biomass on the severity of imported Plasmodium falciparum malaria.

    Science.gov (United States)

    Argy, Nicolas; Kendjo, Eric; Augé-Courtoi, Claire; Cojean, Sandrine; Clain, Jérôme; Houzé, Pascal; Thellier, Marc; Hubert, Veronique; Deloron, Philippe; Houzé, Sandrine

    2017-01-01

    Imported malaria in France is characterized by various clinical manifestations observed in a heterogeneous population of patients such as travelers/expatriates and African migrants. In this population, host factors and parasite biomass associated with severe imported malaria are poorly known. From data collected by the Centre National de Référence du Paludisme, we identified epidemiological, demographic and biological features including parasite biomass and anti-plasmodial antibody levels (negative, positive and strongly positive serology) associated with different disease severity groups (very severe, moderately severe, and uncomplicated malaria) in 3 epidemiological groups (travelers/expatriates, first- and second-generation migrants). Age, ethnicity, absence of prior infection with P. falciparum, antibody levels, plasma PfHRP2 levels, total and circulating parasite biomass were related to severe malaria onset. Sequestered parasite biomass tended to be increased in very severe malaria, and was strongly correlated to the antibody level of the host. Prior exposure to P. falciparum is associated with high anti-plasmodial antibody levels which influence clinical presentation of imported malaria and its correlated circulating and sequestered parasite burden.

  5. Natural and human induced factors influencing the abundance of Schistosoma host snails in Zambia.

    Science.gov (United States)

    Monde, Concillia; Syampungani, Stephen; van den Brink, Paul J

    2016-06-01

    Schistosomiasis remains a global public health problem affecting about 240 million people. In Zambia, 2 million are infected while 3 million live with the risk of getting infected. Research and interventions relating to schistosomiasis are mainly linked to disease epidemiology. Malacological and ecological aspects of the disease are superficially understood. Developing effective control measures requires an understanding of interacting environmental and socioeconomic factors of host snails vis-a-vis schistosomiasis. Therefore, the present work involved collecting social and environmental data in a large field study in two zones in Zambia that are different in terms of temperature and rainfall amounts. Social data collected through questionnaires included demographic, educational and knowledge of schistosomiasis disease dynamics. Environmental data included physicochemical factors, aquatic plants and snails. Gender (P < 0.001) significantly influences livelihood strategies, while age (P = 0.069) and level of education (P = 0.086) have a moderate influence in zone I. In zone III, none of these factors (age, P = 0.378; gender, P = 0.311; education, P = 0.553) play a significant role. Environmental parameters explained 43 and 41 % variation in species composition for zones I and III, respectively. Most respondents' (52 %, 87 %) perception is that there are more cases of bilharzia in hot season than in other seasons (rainy season 23 %, 7 %; cold season 8 %, 0 % and year round 17 %, 6 %) for zone I and zone III, respectively.

  6. Influence of temperature on symptom expression, detection of host factors in virus infected Piper nigrum L.

    Science.gov (United States)

    Umadevi, P; Bhat, A I; Krishnamurthy, K S; Anandaraj, M

    2016-05-01

    Expression of symptoms in black pepper plants (Piper nigrum) infected with Piper yellow mottle virus (PYMoV) vary depending on the season, being high during summer months. Here, we explored the influence of temperature on symptom expression in PYMoV infected P. nigrum. Our controlled environment study revealed increase in virus titer, total proteins, IAA and reducing sugars when exposed to temperature stress. There was change in the 2-D separated protein before and after exposure. The 2-D proteomics LC-MS identified host and viral proteins suggesting virus-host interaction during symptom expression. The analysis as well as detection of host biochemical compounds may help in understanding the detailed mechanisms underlying the viral replication and damage to the crop, and thereby plan management strategies.

  7. Ecological and genetic factors influencing the transition between host-use strategies in sympatric Heliconius butterflies.

    Science.gov (United States)

    Merrill, R M; Naisbit, R E; Mallet, J; Jiggins, C D

    2013-09-01

    Shifts in host-plant use by phytophagous insects have played a central role in their diversification. Evolving host-use strategies will reflect a trade-off between selection pressures. The ecological niche of herbivorous insects is partitioned along several dimensions, and if populations remain in contact, recombination will break down associations between relevant loci. As such, genetic architecture can profoundly affect the coordinated divergence of traits and subsequently the ability to exploit novel habitats. The closely related species Heliconius cydno and H. melpomene differ in mimetic colour pattern, habitat and host-plant use. We investigate the selection pressures and genetic basis underlying host-use differences in these two species. Host-plant surveys reveal that H. melpomene specializes on a single species of Passiflora. This is also true for the majority of other Heliconius species in secondary growth forest at our study site, as expected under a model of interspecific competition. In contrast, H. cydno, which uses closed-forest habitats where both Heliconius and Passiflora are less common, appears not to be restricted by competition and uses a broad selection of the available Passiflora. However, other selection pressures are likely involved, and field experiments reveal that early larval survival of both butterfly species is highest on Passiflora menispermifolia, but most markedly so for H. melpomene, the specialist on that host. Finally, we demonstrate an association between host-plant acceptance and colour pattern amongst interspecific hybrids, suggesting that major loci underlying these important ecological traits are physically linked in the genome. Together, our results reveal ecological and genetic associations between shifts in habitat, host use and mimetic colour pattern that have likely facilitated both speciation and coexistence.

  8. SARS Pathogenesis: Host Factors

    NARCIS (Netherlands)

    A. de Lang (Anna)

    2012-01-01

    textabstractWhile it is hypothesized that Sever Acute Respiratory Syndrome (SARS) in humans is caused by a disproportional immune response illustrated by inappropriate induction of inflammatory cytokines, the exact nature of the host response to SARS coronavirus (CoV) infection causing severe

  9. Dual RNA-sequencing of Eucalyptus nitens during Phytophthora cinnamomi challenge reveals pathogen and host factors influencing compatibility

    Directory of Open Access Journals (Sweden)

    Febe Elizabeth Meyer

    2016-03-01

    Full Text Available Damage caused by Phytophthora cinnamomi Rands remains an important concern on forest tree species. The pathogen causes root and collar rot, stem cankers and dieback of various economically important Eucalyptus spp. In South Africa, susceptible cold tolerant Eucalyptus plantations have been affected by various Phytophthora spp. with P. cinnamomi considered one of the most virulent. The molecular basis of this compatible interaction is poorly understood. In this study, susceptible Eucalyptus nitens plants were stem inoculated with P. cinnamomi and tissue was harvested five days post inoculation. Dual RNA-sequencing, a technique which allows the concurrent detection of both pathogen and host transcripts during infection, was performed. Approximately 1% of the reads mapped to the draft genome of P. cinnamomi while 78% of the reads mapped to the Eucalyptus grandis genome. The highest expressed P. cinnamomi gene in planta was a putative crinkler effector (CRN1. Phylogenetic analysis indicated the high similarity of this P. cinnamomi CRN1 to that of Phytophthora infestans. Some CRN effectors are known to target host nuclei to suppress defense. In the host, over 1400 genes were significantly differentially expressed in comparison to mock inoculated trees, including suites of pathogenesis related (PR genes. In particular, a PR-9 peroxidase gene with a high similarity to a Carica papaya PR-9 ortholog previously shown to be suppressed upon infection by Phytophthora palmivora was down-regulated two-fold. This PR-9 gene may represent a cross-species effector target during P. cinnamomi infection. This study identified pathogenicity factors, potential manipulation targets and attempted host defense mechanisms activated by E. nitens that contributed to the susceptible outcome of the interaction.

  10. Host factors in nidovirus replication

    NARCIS (Netherlands)

    Wilde, Adriaan Hugo de

    2013-01-01

    The interplay between nidoviruses and the infected host cell was investigated. Arterivirus RNA-synthesising activity was shown to depend on intact membranes and on a cytosolic host protein which does not cosediment with the RTC. Furthermore, the immunosuppressant drug cyclosporin A (CsA) blocks repl

  11. Population differences in host immune factors may influence survival of Gunnison's prairie dogs (Cynomys Gunnisoni) during plague outbreaks

    Science.gov (United States)

    Busch, Joseph D.; Van Andel, Roger; Cordova, Jennifer; Colman, Rebecca E.; Keim, Paul; Rocke, Tonie E.; Leid, Jeff G.; Van Pelt, William E.; Wagner, David M.

    2011-01-01

    Over the past 40 yr, epizootics of plague (Yersinia pestis) in northern Arizona have reduced populations of the Gunnison’s prairie dog (Cynomys gunnisoni), with the exception of a large population found in the Aubrey Valley (AV). To examine potential mechanisms accounting for their survival, we collected prairie dog serum samples in 2005–2006 from AV and a neighboring population near Seligman (SE), Arizona. We quantified gene expression at 58 diverse immune proteins using a multiplexed enzyme-linked immunosorbent assay panel. We found a subset of proteins important in coagulation and inflammation (tissue factor [TF], calbindin [Cal], and thrombopoietin [TPO]) and T-cell responses (CD40L and CD40) that were present in AV at levels two to eight times greater than SE. These results suggest that AV and SE animals might differ in their ability to mount an immune response.

  12. Influencing factors of distribution of Trichinella larvae in host muscles%旋毛虫幼虫在宿主肌组织中分布的影响因素

    Institute of Scientific and Technical Information of China (English)

    李立宏; 姜文静

    2012-01-01

    The distribution states of Trichinella spimlis larvae in host muscles are very complicated, and they are possibly in-fluenced by many factors, such as host species, the physiological condition of host muscles, Trichinella species, the encapsulat-ing condition of Trichinella spiralis encapsulated larvae, the level of infection and others. This paper summarizes the advance in the study of the influencing factors of distribution of Trichinella spiralis encapsulated larvae in host muscles.%旋毛虫幼虫在宿主肌组织中的分布受多种因素的影响,如宿主种类、肌肉生理状况、旋毛虫种别、旋毛虫幼虫能否成囊、感染量等.本文对旋毛虫幼虫在宿主肌组织分布的影响因素作一综述.

  13. Evaluating the Biological and Ecological Factors Influencing Transmission of Larval Digenetic Trematodes: A Test of Second Intermediate Host Specificity of Two North American Halipegus Species.

    Science.gov (United States)

    Stigge, Heather A; Bolek, Matthew G

    2016-12-01

    approximate 2-fold difference in the average percentage of worms that established in odonates from the ostracod, Cypridopsis sp., than from the harpacticoid copepod, Phyllognathopus sp., and the difference was nearly 3-fold between Cypridopsis sp. and the cyclopoid copepod, Thermocyclops sp. Therefore, despite all 3 microcrustacean species becoming infected, not all species were equally suited for transmission and completion of the life cycle. Differences among the 3 microcrustacean species in cercaria ingestion, metacercarial growth and development, and odonate predation rates on infected microcrustacean species were important factors in determining transmission of the 2 Halipegus species to odonate hosts.

  14. Responsiveness of cardiometabolic-related microbiota to diet is influenced by host genetics

    OpenAIRE

    O’Connor, Annalouise; Quizon, Pamela M.; Albright, Jody E.; Lin, Fred T.; Brian J Bennett

    2014-01-01

    Intestinal microbial community structure is driven by host genetics in addition to environmental factors such as diet. In comparison with environmental influences, the effect of host genetics on intestinal microbiota, and how host-driven differences alter host metabolism is unclear. Additionally, the interaction between host genetics and diet, and the impact on the intestinal microbiome and possible down-stream effect on host metabolism is not fully understood, but represents another aspects ...

  15. The alternative sigma factor B modulates virulence gene expression in a murine Staphylococcus aureus infection model but does not influence kidney gene expression pattern of the host.

    Science.gov (United States)

    Depke, Maren; Burian, Marc; Schäfer, Tina; Bröker, Barbara M; Ohlsen, Knut; Völker, Uwe

    2012-01-01

    Infections caused by Staphylococcus aureus are associated with significant morbidity and mortality and are an increasing threat not only in hospital settings. The expression of the staphylococcal virulence factor repertoire is known to be affected by the alternative sigma factor B (SigB). However, its impact during infection still is a matter of debate. Kidney tissues of controls or mice infected with S. aureus HG001 or its isogenic sigB mutant were analyzed by transcriptome profiling to monitor the host response, and additionally expression of selected S. aureus genes was monitored by RT-qPCR. Direct transcript analysis by RT-qPCR revealed significant SigB activity in all mice infected with the wild-type strain, but not in its isogenic sigB mutant (p<0.0001). Despite a clear-cut difference in the SigB-dependent transcription pattern of virulence genes (clfA, aur, and hla), the host reaction to infection (either wild type or sigB mutant) was almost identical. Despite its significant activity in vivo, loss of SigB did neither have an effect on the outcome of infection nor on murine kidney gene expression pattern. Thus, these data support the role of SigB as virulence modulator rather than being a virulence determinant by itself.

  16. Host and Viral Factors in HIV-Mediated Bystander Apoptosis

    Science.gov (United States)

    Garg, Himanshu; Joshi, Anjali

    2017-01-01

    Human immunodeficiency virus (HIV) infections lead to a progressive loss of CD4 T cells primarily via the process of apoptosis. With a limited number of infected cells and vastly disproportionate apoptosis in HIV infected patients, it is believed that apoptosis of uninfected bystander cells plays a significant role in this process. Disease progression in HIV infected individuals is highly variable suggesting that both host and viral factors may influence HIV mediated apoptosis. Amongst the viral factors, the role of Envelope (Env) glycoprotein in bystander apoptosis is well documented. Recent evidence on the variability in apoptosis induction by primary patient derived Envs underscores the role of Env glycoprotein in HIV disease. Amongst the host factors, the role of C-C Chemokine Receptor type 5 (CCR5), a coreceptor for HIV Env, is also becoming increasingly evident. Polymorphisms in the CCR5 gene and promoter affect CCR5 cell surface expression and correlate with both apoptosis and CD4 loss. Finally, chronic immune activation in HIV infections induces multiple defects in the immune system and has recently been shown to accelerate HIV Env mediated CD4 apoptosis. Consequently, those factors that affect CCR5 expression and/or immune activation in turn indirectly regulate HIV mediated apoptosis making this phenomenon both complex and multifactorial. This review explores the complex role of various host and viral factors in determining HIV mediated bystander apoptosis. PMID:28829402

  17. Host allometry influences the evolution of parasite host-generalism: theory and meta-analysis

    Science.gov (United States)

    Hurford, Amy; Ellison, Amy R.

    2017-01-01

    Parasites vary widely in the diversity of hosts they infect: some parasite species are specialists—infecting just a single host species, while others are generalists, capable of infecting many. Understanding the factors that drive parasite host-generalism is of basic biological interest, but also directly relevant to predicting disease emergence in new host species, identifying parasites that are likely to have unidentified additional hosts, and assessing transmission risk. Here, we use mathematical models to investigate how variation in host body size and environmental temperature affect the evolution of parasite host-generalism. We predict that parasites are more likely to evolve a generalist strategy when hosts are large-bodied, when variation in host body size is large, and in cooler environments. We then explore these predictions using a newly updated database of over 20 000 fish–macroparasite associations. Within the database we see some evidence supporting these predictions, but also highlight mismatches between theory and data. By combining these two approaches, we establish a theoretical basis for interpreting empirical data on parasites' host specificity and identify key areas for future work that will help untangle the drivers of parasite host-generalism. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289257

  18. Mesoscale spatiotemporal variability in a complex host-parasite system influenced by intermediate host body size.

    Science.gov (United States)

    Rodríguez, Sara M; Valdivia, Nelson

    2017-01-01

    Parasites are essential components of natural communities, but the factors that generate skewed distributions of parasite occurrences and abundances across host populations are not well understood. Here, we analyse at a seascape scale the spatiotemporal relationships of parasite exposure and host body-size with the proportion of infected hosts (i.e., prevalence) and aggregation of parasite burden across ca. 150 km of the coast and over 22 months. We predicted that the effects of parasite exposure on prevalence and aggregation are dependent on host body-sizes. We used an indirect host-parasite interaction in which migratory seagulls, sandy-shore molecrabs, and an acanthocephalan worm constitute the definitive hosts, intermediate hosts, and endoparasite, respectively. In such complex systems, increments in the abundance of definitive hosts imply increments in intermediate hosts' exposure to the parasite's dispersive stages. Linear mixed-effects models showed a significant, albeit highly variable, positive relationship between seagull density and prevalence. This relationship was stronger for small (cephalothorax length >15 mm) than large molecrabs (<15 mm). Independently of seagull density, large molecrabs carried significantly more parasites than small molecrabs. The analysis of the variance-to-mean ratio of per capita parasite burden showed no relationship between seagull density and mean parasite aggregation across host populations. However, the amount of unexplained variability in aggregation was strikingly higher in larger than smaller intermediate hosts. This unexplained variability was driven by a decrease in the mean-variance scaling in heavily infected large molecrabs. These results show complex interdependencies between extrinsic and intrinsic population attributes on the structure of host-parasite interactions. We suggest that parasite accumulation-a characteristic of indirect host-parasite interactions-and subsequent increasing mortality rates over

  19. Virus and host factors affecting the clinical outcome of Bluetongue Virus infection

    NARCIS (Netherlands)

    Caporale, M.; Gialleonorado, L.; Janowicz, A.; Wilkie, G.; Shaw, A.; Savini, G.; Rijn, van P.A.; Mertens, P.; Ventura, M.; Palmarini, M.

    2014-01-01

    Bluetongue is a major infectious disease of ruminants caused by bluetongue virus (BTV), an arbovirus transmitted by Culicoides. Here, we assessed virus and host factors influencing the clinical outcome of BTV infection using a single experimental framework. We investigated how mammalian host species

  20. Macrophage Migration Inhibitory Factor (MIF) of the protozoan parasite Eimeria influences the components of the immune system of its host, the chicken

    Science.gov (United States)

    Macrophage migration inhibitory factor (MIF) is a soluble factor produced by sensitized T lymphocytes that inhibits the random migration of macrophages. Homologues of MIF from invertebrates have been identified making it an interesting molecule from a functional perspective. In the present study, ...

  1. Mesoscale spatiotemporal variability in a complex host-parasite system influenced by intermediate host body size

    Directory of Open Access Journals (Sweden)

    Sara M. Rodríguez

    2017-08-01

    Full Text Available Background Parasites are essential components of natural communities, but the factors that generate skewed distributions of parasite occurrences and abundances across host populations are not well understood. Methods Here, we analyse at a seascape scale the spatiotemporal relationships of parasite exposure and host body-size with the proportion of infected hosts (i.e., prevalence and aggregation of parasite burden across ca. 150 km of the coast and over 22 months. We predicted that the effects of parasite exposure on prevalence and aggregation are dependent on host body-sizes. We used an indirect host-parasite interaction in which migratory seagulls, sandy-shore molecrabs, and an acanthocephalan worm constitute the definitive hosts, intermediate hosts, and endoparasite, respectively. In such complex systems, increments in the abundance of definitive hosts imply increments in intermediate hosts’ exposure to the parasite’s dispersive stages. Results Linear mixed-effects models showed a significant, albeit highly variable, positive relationship between seagull density and prevalence. This relationship was stronger for small (cephalothorax length >15 mm than large molecrabs (<15 mm. Independently of seagull density, large molecrabs carried significantly more parasites than small molecrabs. The analysis of the variance-to-mean ratio of per capita parasite burden showed no relationship between seagull density and mean parasite aggregation across host populations. However, the amount of unexplained variability in aggregation was strikingly higher in larger than smaller intermediate hosts. This unexplained variability was driven by a decrease in the mean-variance scaling in heavily infected large molecrabs. Conclusions These results show complex interdependencies between extrinsic and intrinsic population attributes on the structure of host-parasite interactions. We suggest that parasite accumulation—a characteristic of indirect host

  2. H pylori and host interactions that influence pathogenesis

    Institute of Scientific and Technical Information of China (English)

    Ellen J Beswick; Giovanni Suarez; Victor E Reyes

    2006-01-01

    H pylori is probably the most prevalent human pathogen worldwide. Since it was initially suggested in 1983 by Marshall and Warren to be implicated in gastritis and pepticulcer disease,H pylori has also been implicated in gastric carcinoma and was classified as a class I carcinogen. In the last two decades, a noteworthy body of research has revealed the multiple processes that this gram negative bacterium activates to cause gastroduodenal disease in humans. Most infections are acquired early in life and may persist for the life of the individual.While infected individuals mount an inflammatory response that becomes chronic, along with a detectable adaptive immune response, these responses are ineffective in clearing the infection. H pylori has unique features that allow it to reside within the harsh conditions of the gastric environment, and also to evade the host immune response. In this review, we discuss the various virulence factors expressed by this bacterium and how they interact with the host epithelium to influence pathogenesis.

  3. Discovery of insect and human dengue virus host factors.

    Science.gov (United States)

    Sessions, October M; Barrows, Nicholas J; Souza-Neto, Jayme A; Robinson, Timothy J; Hershey, Christine L; Rodgers, Mary A; Ramirez, Jose L; Dimopoulos, George; Yang, Priscilla L; Pearson, James L; Garcia-Blanco, Mariano A

    2009-04-23

    Dengue fever is the most frequent arthropod-borne viral disease of humans, with almost half of the world's population at risk of infection. The high prevalence, lack of an effective vaccine, and absence of specific treatment conspire to make dengue fever a global public health threat. Given their compact genomes, dengue viruses (DENV-1-4) and other flaviviruses probably require an extensive number of host factors; however, only a limited number of human, and an even smaller number of insect host factors, have been identified. Here we identify insect host factors required for DENV-2 propagation, by carrying out a genome-wide RNA interference screen in Drosophila melanogaster cells using a well-established 22,632 double-stranded RNA library. This screen identified 116 candidate dengue virus host factors (DVHFs). Although some were previously associated with flaviviruses (for example, V-ATPases and alpha-glucosidases), most of the DVHFs were newly implicated in dengue virus propagation. The dipteran DVHFs had 82 readily recognizable human homologues and, using a targeted short-interfering-RNA screen, we showed that 42 of these are human DVHFs. This indicates notable conservation of required factors between dipteran and human hosts. This work suggests new approaches to control infection in the insect vector and the mammalian host.

  4. Human Genome-Wide RNAi Screen for Host Factors That Modulate Intracellular Salmonella Growth

    OpenAIRE

    Thornbrough, Joshua M.; Tom Hundley; Raphael Valdivia; Worley, Micah J.

    2012-01-01

    Salmonella enterica is a bacterial pathogen of humans that can proliferate within epithelial cells as well as professional phagocytes of the immune system. While much has been learned about the microbial genes that influence the infectious process through decades of intensive research, relatively little is known about the host factors that affect infection. We performed a genome-wide siRNA screen to identify host genes that Salmonella enterica serovar Typhimurium (S. typhimurium) utilizes to ...

  5. Reduction of Influence Factors

    NARCIS (Netherlands)

    Regtien, Paulus P.L.; Sydenham, Peter H.; Thorn, Richard

    Any measurement system has imperfections and any act of measurement is liable to errors. Measurement errors either originate from system deficiencies (for instance system noise, quantization, and drift), or are due to environmental influences such as thermal, electromagnetic, and mechanical

  6. Citizen science data reveal ecological, historical and evolutionary factors shaping interactions between woody hosts and wood-inhabiting fungi.

    Science.gov (United States)

    Heilmann-Clausen, Jacob; Maruyama, Pietro K; Bruun, Hans Henrik; Dimitrov, Dimitar; Laessøe, Thomas; Frøslev, Tobias Guldberg; Dalsgaard, Bo

    2016-12-01

    Woody plants host diverse communities of associated organisms, including wood-inhabiting fungi. In this group, host effects on species richness and interaction network structure are not well understood, especially not at large geographical scales. We investigated ecological, historical and evolutionary determinants of fungal species richness and network modularity, that is, subcommunity structure, across woody hosts in Denmark, using a citizen science data set comprising > 80 000 records of > 1000 fungal species on 91 genera of woody plants. Fungal species richness was positively related to host size, wood pH, and the number of species in the host genus, with limited influence of host frequency and host history, that is, time since host establishment in the area. Modularity patterns were unaffected by host history, but largely reflected host phylogeny. Notably, fungal communities differed substantially between angiosperm and gymnosperm hosts. Host traits and evolutionary history appear to be more important than host frequency and recent history in structuring interactions between hosts and wood-inhabiting fungi. High wood acidity appears to act as a stress factor reducing fungal species richness, while large host size, providing increased niche diversity, enhances it. In some fungal groups that are known to interact with live host cells in the establishment phase, host selectivity is common, causing a modular community structure. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  7. Defining dysbiosis and its influence on host immunity and disease.

    Science.gov (United States)

    Petersen, Charisse; Round, June L

    2014-07-01

    Mammalian immune system development depends on instruction from resident commensal microorganisms. Diseases associated with abnormal immune responses towards environmental and self antigens have been rapidly increasing over the last 50 years. These diseases include inflammatory bowel disease (IBD), multiple sclerosis (MS), type I diabetes (T1D), allergies and asthma. The observation that people with immune mediated diseases house a different microbial community when compared to healthy individuals suggests that pathogenesis arises from improper training of the immune system by the microbiota. However, with hundreds of different microorganisms on our bodies it is hard to know which of these contribute to health and more importantly how? Microbiologists studying pathogenic organisms have long adhered to Koch's postulates to directly relate a certain disease to a specific microbe, raising the question of whether this might be true of commensal-host relationships as well. Emerging evidence supports that rather than one or two dominant organisms inducing host health, the composition of the entire community of microbial residents influences a balanced immune response. Thus, perturbations to the structure of complex commensal communities (referred to as dysbiosis) can lead to deficient education of the host immune system and subsequent development of immune mediated diseases. Here we will overview the literature that describes the causes of dysbiosis and the mechanisms evolved by the host to prevent these changes to community structure. Building off these studies, we will categorize the different types of dysbiosis and define how collections of microorganisms can influence the host response. This research has broad implications for future therapies that go beyond the introduction of a single organism to induce health. We propose that identifying mechanisms to re-establish a healthy complex microbiota after dysbiosis has occurred, a process we will refer to as rebiosis

  8. Phonological Awareness: Factors of Influence

    Science.gov (United States)

    Frohlich, Linda Paulina; Petermann, Franz; Metz, Dorothee

    2013-01-01

    Early child development is influenced by various genetic and environmental factors. This study aims to identify factors that affect the phonological awareness of preschool and first grade children. Based on a sample of 330 German-speaking children (mean age = 6.2 years) the following domains were evaluated: Parent factors, birth and pregnancy,…

  9. Influence of host iron status on Plasmodium falciparum infection

    Directory of Open Access Journals (Sweden)

    Martha A. Clark

    2014-05-01

    Full Text Available Iron deficiency affects one quarter of the world’s population and causes significant morbidity, including detrimental effects on immune function and cognitive development. Accordingly, the World Health Organization recommends routine iron supplementation in children and adults in areas with high prevalence of iron deficiency. However, a large body of clinical and epidemiological evidence has accumulated which clearly demonstrates that host iron deficiency is protective against falciparum malaria and that host iron supplementation may increase the risk of malaria. Although many effective antimalarial treatments and preventive measures are available, malaria remains a significant public health problem, in part because the mechanisms of malaria pathogenesis remain obscured by the complexities in the relationships between parasite virulence factors, host susceptibility traits, and the immune responses that modulate disease. Here we review (i the clinical and epidemiological data that describes the relationship between host iron status and malaria infection and (ii the progress being made to understand the biological basis for these clinical and epidemiological observations.

  10. Drivers of aggregation in a novel arboreal parasite: the influence of host size and infra-populations.

    Science.gov (United States)

    Yule, Kirsty J; Burns, Kevin C

    2015-02-01

    As a novel arboreal parasite, New Zealand's largest endemic moth, Aenetus virescens, is a biological oddity. With arguably the most unusual lepidopteran life history on earth, larvae grow to 100mm, spending ∼6 years as wood-boring parasites feeding on host tree phloem. Parasite fitness is a product of host suitability. Parasite discrimination between heterogeneous hosts in fragmented populations shapes parasite aggregation. We investigated whether A. virescens aggregation among hosts occurs randomly (target area effect), or if larvae select hosts based on host quality (ideal free distribution). Using long-term larval growth as an indicator of energy intake, we examined A. virescens aggregation in relation to host size and infra-population. Using a generalised linear model, the relationship between parasite intensity and host tree size was analysed. Reduced major axis regression was used to evaluate A. virescens growth after 1 year. Linear mixed-effects models inferred the influence of parasite infra-population on parasite growth, with host tree as a random factor. Results indicate parasite intensity scaled positively with host size. Furthermore, parasite growth remained consistent throughout ontogeny regardless of host size or parasite infra-population. Aenetus virescens aggregation among hosts violates the ideal free distribution hypothesis, occurring instead as a result of host size, supporting the target area effect.

  11. Host Cell Factors as Antiviral Targets in Arenavirus Infection

    Directory of Open Access Journals (Sweden)

    Elsa B. Damonte

    2012-09-01

    Full Text Available Among the members of the Arenaviridae family, Lassa virus and Junin virus generate periodic annual outbreaks of severe human hemorrhagic fever (HF in endemic areas of West Africa and Argentina, respectively. Given the human health threat that arenaviruses represent and the lack of a specific and safe chemotherapy, the search for effective antiviral compounds is a continuous demanding effort. Since diverse host cell pathways and enzymes are used by RNA viruses to fulfill their replicative cycle, the targeting of a host process has turned an attractive antiviral approach in the last years for many unrelated virus types. This strategy has the additional benefit to reduce the serious challenge for therapy of RNA viruses to escape from drug effects through selection of resistant variants triggered by their high mutation rate. This article focuses on novel strategies to identify inhibitors for arenavirus therapy, analyzing the potential for antiviral developments of diverse host factors essential for virus infection.

  12. Host cell factors as antiviral targets in arenavirus infection.

    Science.gov (United States)

    Linero, Florencia N; Sepúlveda, Claudia S; Giovannoni, Federico; Castilla, Viviana; García, Cybele C; Scolaro, Luis A; Damonte, Elsa B

    2012-09-01

    Among the members of the Arenaviridae family, Lassa virus and Junin virus generate periodic annual outbreaks of severe human hemorrhagic fever (HF) in endemic areas of West Africa and Argentina, respectively. Given the human health threat that arenaviruses represent and the lack of a specific and safe chemotherapy, the search for effective antiviral compounds is a continuous demanding effort. Since diverse host cell pathways and enzymes are used by RNA viruses to fulfill their replicative cycle, the targeting of a host process has turned an attractive antiviral approach in the last years for many unrelated virus types. This strategy has the additional benefit to reduce the serious challenge for therapy of RNA viruses to escape from drug effects through selection of resistant variants triggered by their high mutation rate. This article focuses on novel strategies to identify inhibitors for arenavirus therapy, analyzing the potential for antiviral developments of diverse host factors essential for virus infection.

  13. Susceptibility to Phytophthora ramorum in a key infectious host: landscape variation in host genotype, host phenotype, and environmental factors.

    Science.gov (United States)

    Anacker, Brian L; Rank, Nathan E; Hüberli, Daniel; Garbelotto, Matteo; Gordon, Sarah; Harnik, Tami; Whitkus, Richard; Meentemeyer, Ross

    2008-01-01

    Sudden oak death is an emerging forest disease caused by the invasive pathogen Phytophthora ramorum. Genetic and environmental factors affecting susceptibility to P. ramorum in the key inoculum-producing host tree Umbellularia californica (bay laurel) were examined across a heterogeneous landscape in California, USA. Laboratory susceptibility trials were conducted on detached leaves and assessed field disease levels for 97 host trees from 12 225-m(2) plots. Genotype and phenotype characteristics were assessed for each tree. Effects of plot-level environmental conditions (understory microclimate, amount of solar radiation and topographic moisture potential) on disease expression were also evaluated. Susceptibility varied significantly among U. californica trees, with a fivefold difference in leaf lesion size. Lesion size was positively related to leaf area, but not to other phenotypic traits or to field disease level. Genetic diversity was structured at three spatial scales, but primarily among individuals within plots. Lesion size was significantly related to amplified fragment length polymorphism (AFLP) markers, but local environment explained most variation in field disease level. Thus, substantial genetic variation in susceptibility to P. ramorum occurs in its principal foliar host U. californica, but local environment mediates expression of susceptibility in nature.

  14. Influence of host diet and phylogeny on parasite sharing by fish in a diverse tropical floodplain.

    Science.gov (United States)

    Lima, L B; Bellay, S; Giacomini, H C; Isaac, A; Lima-Junior, D P

    2016-03-01

    The patterns of parasite sharing among hosts have important implications for ecosystem structure and functioning, and are influenced by several ecological and evolutionary factors associated with both hosts and parasites. Here we evaluated the influence of fish diet and phylogenetic relatedness on the pattern of infection by parasites with contrasting life history strategies in a freshwater ecosystem of key ecological importance in South America. The studied network of interactions included 52 fish species, which consumed 58 food types and were infected with 303 parasite taxa. Our results show that both diet and evolutionary history of hosts significantly explained parasite sharing; phylogenetically close fish species and/or species sharing food types tend to share more parasites. However, the effect of diet was observed only for endoparasites in contrast to ectoparasites. These results are consistent with the different life history strategies and selective pressures imposed on these groups: endoparasites are in general acquired via ingestion by their intermediate hosts, whereas ectoparasites actively seek and attach to the gills, body surface or nostrils of its sole host, thus not depending directly on its feeding habits.

  15. Plant host and soil origin influence fungal and bacterial assemblages in the roots of woody plants.

    Science.gov (United States)

    Bonito, Gregory; Reynolds, Hannah; Robeson, Michael S; Nelson, Jessica; Hodkinson, Brendan P; Tuskan, Gerald; Schadt, Christopher W; Vilgalys, Rytas

    2014-07-01

    Microbial communities in plant roots provide critical links between above- and belowground processes in terrestrial ecosystems. Variation in root communities has been attributed to plant host effects and microbial host preferences, as well as to factors pertaining to soil conditions, microbial biogeography and the presence of viable microbial propagules. To address hypotheses regarding the influence of plant host and soil biogeography on root fungal and bacterial communities, we designed a trap-plant bioassay experiment. Replicate Populus, Quercus and Pinus plants were grown in three soils originating from alternate field sites. Fungal and bacterial community profiles in the root of each replicate were assessed through multiplex 454 amplicon sequencing of four loci (i.e., 16S, SSU, ITS, LSU rDNA). Soil origin had a larger effect on fungal community composition than did host species, but the opposite was true for bacterial communities. Populus hosted the highest diversity of rhizospheric fungi and bacteria. Root communities on Quercus and Pinus were more similar to each other than to Populus. Overall, fungal root symbionts appear to be more constrained by dispersal and biogeography than by host availability.

  16. Factors Influencing Healthcare Service Quality

    OpenAIRE

    Ali Mohammad Mosadeghrad

    2014-01-01

    Background The main purpose of this study was to identify factors that influence healthcare quality in the Iranian context. Methods Exploratory in-depth individual and focus group interviews were conducted with 222 healthcare stakeholders including healthcare providers, managers, policy-makers, and payers to identify factors affecting the quality of healthcare services provided in Iranian healthcare organisations. Results Quality in healthcare is a production o...

  17. Host tree influences on longicorn beetle (Coleoptera: Cerambycidae) attack in subtropical Corymbia (Myrtales: Myrtaceae).

    Science.gov (United States)

    Nahrung, Helen F; Smith, Timothy E; Wiegand, Aaron N; Lawson, Simon A; Debuse, Valerie J

    2014-02-01

    Phoracantha longicorn beetles are endemic to Australia, and some species have become significant pests of eucalypts worldwide, yet little is known about their host plant interactions and factors influencing tree susceptibility in Australia. Here, we investigate the host relationships of Phoracantha solida (Blackburn, 1894) on four eucalypt taxa (one pure species and three hybrid families), examining feeding site physical characteristics including phloem thickness, density, and moisture content, and host tree factors such as diameter, height, growth, taper, and survival. We also determine the cardinal and vertical (within-tree) and horizontal (between-tree) spatial distribution of borers. Fewer than 10% of P. solida attacks were recorded from the pure species (Corymbia citriodora subsp. variegate (Hook)), and this taxon also showed the highest survival, phloem thickness, relative growth rate, and bark:wood area. For the two most susceptible taxa, borer severity was negatively correlated with moisture content, and positively related to phloem density. Borers were nonrandomly and nonuniformly distributed within trees, and were statistically aggregated in 32% of plots. More attacks were situated on the northern side of the tree than the other aspects, and most larvae fed within the lower 50 cm of the bole, with attack height positively correlated with severity. Trees with borers had more dead neighbors, and more bored neighbors, than trees without borers, while within plots, borer incidence and severity were positively correlated. Because the more susceptible taxa overlapped with less susceptible taxa for several physical tree factors, the role of primary and secondary chemistries in determining host suitability needs to be investigated. Nevertheless, taxon, moisture content, phloem density, tree size, and mortality of neighboring trees appeared the most important physical characteristics influencing host suitability for P. solida at this site.

  18. Broad-Host-Range Expression Reveals Native and Host Regulatory Elements That Influence Heterologous Antibiotic Production in Gram-Negative Bacteria.

    Science.gov (United States)

    Zhang, Jia Jia; Tang, Xiaoyu; Zhang, Michelle; Nguyen, Darlene; Moore, Bradley S

    2017-09-05

    Heterologous expression has become a powerful tool for studying microbial biosynthetic gene clusters (BGCs). Here, we extend the transformation-associated recombination cloning and heterologous expression platform for microbial BGCs to include Gram-negative proteobacterial expression hosts. Using a broad-host-range expression platform, we test the implicit assumption that biosynthetic pathways are more successfully expressed in more closely related heterologous hosts. Cloning and expression of the violacein BGC from Pseudoalteromonas luteoviolacea 2ta16 revealed robust production in two proteobacterial hosts, Pseudomonas putida KT2440 and Agrobacterium tumefaciens LBA4404, but very little production of the antibiotic in various laboratory strains of Escherichia coli, despite their closer phylogenetic relationship. We identified a nonclustered LuxR-type quorum-sensing receptor from P. luteoviolacea 2ta16, PviR, that increases pathway transcription and violacein production in E. coli by ∼60-fold independently of acyl-homoserine lactone autoinducers. Although E. coli harbors the most similar homolog of PviR identified from all of the hosts tested, overexpression of various E. coli transcription factors did not result in a statistically significant increase in violacein production, while overexpression of two A. tumefaciens PviR homologs significantly increased production. Thus, this work not only introduces a new genetic platform for the heterologous expression of microbial BGCs, it also challenges the assumption that host phylogeny is an accurate predictor of host compatibility.IMPORTANCE Although Gram-positive heterologous hosts such as Streptomyces have been developed and optimized to support diverse secondary metabolic reactions, there has been comparatively less work on Gram-negative hosts, some of which grow faster and are easier to work with. This work presents a new genetic platform for direct cloning and broad-host-range heterologous expression of BGCs

  19. The Host Specificities of Baculovirus per os Infectivity Factors.

    Directory of Open Access Journals (Sweden)

    Jingjiao Song

    Full Text Available Baculoviruses are insect-specific pathogens with a generally narrow host ranges. Successful primary infection is initiated by the proper interaction of at least 8 conserved per os infectivity factors (PIFs with the host's midgut cells, a process that remains largely a mystery. In this study, we investigated the host specificities of the four core components of the PIF complex, P74, PIF1, PIF2 and PIF3 by using Helicoverpa armigera nucleopolyhedrovirus (HearNPV backbone. The four pifs of HearNPV were replaced by their counterparts from a group I Autographa californica multiple nucleopolyhedrovirus (AcMNPV or a group II Spodoptera litura nucleopolyhedrovirus (SpltNPV. Transfection and infection assays showed that all the recombinant viruses were able to produce infectious budded viruses (BVs and were lethal to H. armigera larvae via intrahaemocoelic injection. However, feeding experiments using very high concentration of occlusion bodies demonstrated that all the recombinant viruses completely lost oral infectivity except SpltNPV pif3 substituted pif3-null HearNPV (vHaBacΔpif3-Sppif3-ph. Furthermore, bioassay result showed that the median lethal concentration (LC50 value of vHaBacΔpif3-Sppif3-ph was 23-fold higher than that of the control virus vHaBacΔpif3-Hapif3-ph, indicating that SpltNPV pif3 can only partially substitute the function of HearNPV pif3. These results suggested that most of PIFs tested have strict host specificities, which may account, at least in part, for the limited host ranges of baculoviruses.

  20. Complement factor H in host defense and immune evasion.

    Science.gov (United States)

    Parente, Raffaella; Clark, Simon J; Inforzato, Antonio; Day, Anthony J

    2017-05-01

    Complement is the major humoral component of the innate immune system. It recognizes pathogen- and damage-associated molecular patterns, and initiates the immune response in coordination with innate and adaptive immunity. When activated, the complement system unleashes powerful cytotoxic and inflammatory mechanisms, and thus its tight control is crucial to prevent damage to host tissues and allow restoration of immune homeostasis. Factor H is the major soluble inhibitor of complement, where its binding to self markers (i.e., particular glycan structures) prevents complement activation and amplification on host surfaces. Not surprisingly, mutations and polymorphisms that affect recognition of self by factor H are associated with diseases of complement dysregulation, such as age-related macular degeneration and atypical haemolytic uremic syndrome. In addition, pathogens (i.e., non-self) and cancer cells (i.e., altered-self) can hijack factor H to evade the immune response. Here we review recent (and not so recent) literature on the structure and function of factor H, including the emerging roles of this protein in the pathophysiology of infectious diseases and cancer.

  1. Factors influencing pacing in triathlon.

    Science.gov (United States)

    Wu, Sam Sx; Peiffer, Jeremiah J; Brisswalter, Jeanick; Nosaka, Kazunori; Abbiss, Chris R

    2014-01-01

    Triathlon is a multisport event consisting of sequential swim, cycle, and run disciplines performed over a variety of distances. This complex and unique sport requires athletes to appropriately distribute their speed or energy expenditure (ie, pacing) within each discipline as well as over the entire event. As with most physical activity, the regulation of pacing in triathlon may be influenced by a multitude of intrinsic and extrinsic factors. The majority of current research focuses mainly on the Olympic distance, whilst much less literature is available on other triathlon distances such as the sprint, half-Ironman, and Ironman distances. Furthermore, little is understood regarding the specific physiological, environmental, and interdisciplinary effects on pacing. Therefore, this article discusses the pacing strategies observed in triathlon across different distances, and elucidates the possible factors influencing pacing within the three specific disciplines of a triathlon.

  2. Host conservatism or host specialization? Patterns of fungal diversification are influenced by host specificity in Ophiognomonia (Gnomoniaceae, Diaporthales)

    Science.gov (United States)

    Species of Ophiognomonia (Gnomoniaceae) are perithecial fungi that occur as endophytes, pathogens, and latent saprobes on leaf and stem tissue of plants in the Betulaceae, Fagaceae, Juglandaceae, Lauraceae, Malvaceae, Platanaceae, Rosaceae, Salicaceae, and Sapindaceae. In this study host plant patte...

  3. The developmental race between maturing host plants and their butterfly herbivore - the influence of phenological matching and temperature.

    Science.gov (United States)

    Posledovich, Diana; Toftegaard, Tenna; Wiklund, Christer; Ehrlén, Johan; Gotthard, Karl

    2015-11-01

    Interactions between herbivorous insects and their host plants that are limited in time are widespread. Therefore, many insect-plant interactions result in a developmental race, where herbivores need to complete their development before plants become unsuitable, while plants strive to minimize damage from herbivores by outgrowing them. When spring phenologies of interacting species change asymmetrically in response to climate warming, there will be a change in the developmental state of host plants at the time of insect herbivore emergence. In combination with altered temperatures during the subsequent developmental period, this is likely to affect interaction strength as well as fitness of interacting species. Here, we experimentally explore whether the combined effect of phenological matching and thermal conditions influence the outcome of an insect-host interaction. We manipulated both developmental stages of the host plants at the start of the interaction and temperature during the subsequent developmental period in a model system of a herbivorous butterfly, Anthocharis cardamines, and five of its Brassicaceae host plant species. Larval performance characteristics were favoured by earlier stages of host plants at oviposition as well as by higher developmental temperatures on most of the host species. The probability of a larva needing a second host plant covered the full range from no influence of either phenological matching or temperature to strong effects of both factors, and complex interactions between them. The probability of a plant outgrowing a larva was dependent only on the species identity. This study demonstrates that climatic variation can influence the outcome of consumer-resource interactions in multiple ways and that its effects differ among host plant species. Therefore, climate warming is likely to change the temporal match between larval and plant development in some plant species, but not in the others. This is likely to have important

  4. Odours of Plasmodium falciparum-infected participants influence mosquito-host interactions

    NARCIS (Netherlands)

    Boer, De Jetske G.; Robinson, Ailie; Powers, Stephen J.; Burgers, Saskia L.G.E.; Caulfield, John C.; Birkett, Michael A.; Smallegange, Renate C.; Genderen, Van Perry J.J.; Bousema, Teun; Sauerwein, Robert W.; Pickett, John A.; Takken, Willem; Logan, James G.

    2017-01-01

    Malaria parasites are thought to influence mosquito attraction to human hosts, a phenomenon that may enhance parasite transmission. This is likely mediated by alterations in host odour because of its importance in mosquito host-searching behaviour. Here, we report that the human skin odour profile

  5. Factors Influencing Healthcare Service Quality

    Directory of Open Access Journals (Sweden)

    Ali Mohammad Mosadeghrad

    2014-07-01

    Full Text Available Background The main purpose of this study was to identify factors that influence healthcare quality in the Iranian context. Methods Exploratory in-depth individual and focus group interviews were conducted with 222 healthcare stakeholders including healthcare providers, managers, policy-makers, and payers to identify factors affecting the quality of healthcare services provided in Iranian healthcare organisations. Results Quality in healthcare is a production of cooperation between the patient and the healthcare provider in a supportive environment. Personal factors of the provider and the patient, and factors pertaining to the healthcare organisation, healthcare system, and the broader environment affect healthcare service quality. Healthcare quality can be improved by supportive visionary leadership, proper planning, education and training, availability of resources, effective management of resources, employees and processes, and collaboration and cooperation among providers. Conclusion This article contributes to healthcare theory and practice by developing a conceptual framework that provides policy-makers and managers a practical understanding of factors that affect healthcare service quality.

  6. Effects of Host Plant Factors on the Bacterial Communities Associated with Two Whitefly Sibling Species.

    Science.gov (United States)

    Su, Ming-Ming; Guo, Lei; Tao, Yun-Li; Zhang, You-Jun; Wan, Fang-Hao; Chu, Dong

    2016-01-01

    Although discrepancy in the specific traits and ecological characteristics of Bemisia tabaci between species are partially attributed to the B. tabaci-associated bacteria, the factors that affect the diversity of B. tabaci-associated bacteria are not well-understood. We used the metagenomic approach to characterize the B. tabaci-associated bacterial community because the approach is an effective tool to identify the bacteria. To investigate the effects of the host plant and a virus, tomato yellow leaf curl virus (TYLCV), on the bacterial communities of B. tabaci sibling species B and Q, we analyzed the bacterial communities associated with whitefly B and Q collected from healthy cotton, healthy tomato, and TYLCV-infected tomato. The analysis used miseq-based sequencing of a variable region of the bacterial 16S rDNA gene. For the bacteria associated with B. tabaci, we found that the influence of the host plant species was greater than that of the whitefly cryptic species. With further analysis of host plants infected with the TYLCV, the virus had no significant effects on the B. tabaci-associated bacterial community. The effects of different plant hosts and TYLCV-infection on the diversity of B. tabaci-associated bacterial communities were successfully analyzed in this study. To explain why B. tabaci sibling species with different host ranges differ in performance, the analysis of the bacterial community may be essential to the explanation.

  7. Influence of host-related risk indicators on dental caries in permanent dentition.

    Science.gov (United States)

    Delgado-Angulo, Elsa K; Bernabé, Eduardo

    2006-01-01

    The aim of this study was to assess the individual and grouped influence of host-related factors on dental caries experience in permanent dentition of 7-9 year-old children. One hundred and twenty one children were recruited applying a stratified cluster sampling without replacement. Clinical examinations, Colorimetric Test and non-stimulated and stimulated saliva collection were performed; the samples obtained were later incubated using Snyder culture medium. Simple and multiple binary logistic regression analyses were performed to assess the individual and grouped influence of the host-related factors and establish a modelfor predicting dental caries in permanent dentition. 78.5% of the evaluated children presented dental caries in permanent dentition. Binary logistic regression analyses revealMd that only dental caries in deciduous dentition and stimulated salivary flow were significantly associated to dental caries in permanent dentition. The final multivariate model showed that the adjusted OR was 1.76 for an increase of 1 tooth in dmft and 2.29 for a decrease of 1 ml in stimulated salivary flow. Dental caries in deciduous dentition is a risk indicator for dental caries in permanent dentition, and stimulated salivary flow is a protective factor Variables like enamel resistance to acid dissolution and buffer capacity are not related to dental caries in permanent dentition, making them inappropriate for risk studies.

  8. Host genetics and environmental factors regulate ecological succession of the mouse colon tissue-associated microbiota.

    Directory of Open Access Journals (Sweden)

    Philip Smith

    Full Text Available BACKGROUND: The integration of host genetics, environmental triggers and the microbiota is a recognised factor in the pathogenesis of barrier function diseases such as IBD. In order to determine how these factors interact to regulate the host immune response and ecological succession of the colon tissue-associated microbiota, we investigated the temporal interaction between the microbiota and the host following disruption of the colonic epithelial barrier. METHODOLOGY/PRINCIPAL FINDINGS: Oral administration of DSS was applied as a mechanistic model of environmental damage of the colon and the resulting inflammation characterized for various parameters over time in WT and Nod2 KO mice. RESULTS: In WT mice, DSS damage exposed the host to the commensal flora and led to a migration of the tissue-associated bacteria from the epithelium to mucosal and submucosal layers correlating with changes in proinflammatory cytokine profiles and a progressive transition from acute to chronic inflammation of the colon. Tissue-associated bacteria levels peaked at day 21 post-DSS and declined thereafter, correlating with recruitment of innate immune cells and development of the adaptive immune response. Histological parameters, immune cell infiltration and cytokine biomarkers of inflammation were indistinguishable between Nod2 and WT littermates following DSS, however, Nod2 KO mice demonstrated significantly higher tissue-associated bacterial levels in the colon. DSS damage and Nod2 genotype independently regulated the community structure of the colon microbiota. CONCLUSIONS/SIGNIFICANCE: The results of these experiments demonstrate the integration of environmental and genetic factors in the ecological succession of the commensal flora in mammalian tissue. The association of Nod2 genotype (and other host polymorphisms and environmental factors likely combine to influence the ecological succession of the tissue-associated microflora accounting in part for their

  9. Factors influencing alginate gel biocompatibility.

    Science.gov (United States)

    Tam, Susan K; Dusseault, Julie; Bilodeau, Stéphanie; Langlois, Geneviève; Hallé, Jean-Pierre; Yahia, L'Hocine

    2011-07-01

    Alginate remains the most popular polymer used for cell encapsulation, yet its biocompatibility is inconsistent. Two commercially available alginates were compared, one with 71% guluronate (HiG), and the other with 44% (IntG). Both alginates were purified, and their purities were verified. After 2 days in the peritoneal cavity of C57BL/6J mice, barium (Ba)-gel and calcium (Ca)-gel beads of IntG alginate were clean, while host cells were adhered to beads of HiG alginate. IntG gel beads, however, showed fragmentation in vivo while HiG gel beads stayed firm. The physicochemical properties of the sodium alginates and their gels were thoroughly characterized. The intrinsic viscosity of IntG alginate was 2.5-fold higher than that of HiG alginate, suggesting a greater molecular mass. X-ray photoelectron spectroscopy indicated that both alginates were similar in elemental composition, including low levels of counterions in all gels. The wettabilities of the alginates and gels were also identical, as measured by contact angles of water on dry films. Ba-gel beads of HiG alginate resisted swelling and degradation when immersed in water, much more than the other gel beads. These results suggest that the main factors contributing to the biocompatibility of gels of purified alginate are the mannuronate/guluronate content and/or intrinsic viscosity.

  10. Factors influencing pacing in triathlon

    Directory of Open Access Journals (Sweden)

    Wu SSX

    2014-09-01

    Full Text Available Sam SX Wu,1 Jeremiah J Peiffer,2 Jeanick Brisswalter,3 Kazunori Nosaka,1 Chris R Abbiss1 1Centre for Exercise and Sports Science Research, School of Exercise and Health Sciences, Edith Cowan University, Perth, WA, Australia; 2School of Psychology and Exercise Science, Murdoch University, Perth, WA, Australia; 3Laboratory of Human Motricity, Education Sport and Health, University of Nice Sophia Antipolis, Nice, France Abstract: Triathlon is a multisport event consisting of sequential swim, cycle, and run disciplines performed over a variety of distances. This complex and unique sport requires athletes to appropriately distribute their speed or energy expenditure (ie, pacing within each discipline as well as over the entire event. As with most physical activity, the regulation of pacing in triathlon may be influenced by a multitude of intrinsic and extrinsic factors. The majority of current research focuses mainly on the Olympic distance, whilst much less literature is available on other triathlon distances such as the sprint, half-Ironman, and Ironman distances. Furthermore, little is understood regarding the specific physiological, environmental, and interdisciplinary effects on pacing. Therefore, this article discusses the pacing strategies observed in triathlon across different distances, and elucidates the possible factors influencing pacing within the three specific disciplines of a triathlon. Keywords: cycle, endurance, multisport, pacing strategy, run, swim

  11. Host susceptibility factors in mycobacterial infection. Genetics and body morphotype.

    Science.gov (United States)

    Guide, Shireen V; Holland, Steven M

    2002-03-01

    Through identification and evaluation of mutations and polymorphisms in components of the IFN gamma response pathways, a better understanding of the mechanisms and risk factors influencing the development of mycobacterial disease is gained. This may lead the way for development of therapeutic and preventative strategies. Although conventional science has focused on identifying discrete mutations, greater awareness of the impact of subtle changes, both at the genetic (polymorphisms) and physical levels (body morphotype), may prove critical in the investigative process. There has been extraordinary progress in the understanding of mycobacterial susceptibility factors over the last few years. The recognition of characteristic phenotypes will lead to the identification of new genetic bases for disease.

  12. Relative host body condition and food availability influence epidemic dynamics: a Poecilia reticulata-Gyrodactylus turnbulli host-parasite model.

    Science.gov (United States)

    Tadiri, Christina P; Dargent, Felipe; Scott, Marilyn E

    2013-03-01

    Understanding disease transmission is important to species management and human health. Host body condition, nutrition and disease susceptibility interact in a complex manner, and while the individual effects of these variables are well known, our understanding of how they interact and translate to population dynamics is limited. Our objective was to determine whether host relative body condition influences epidemic dynamics, and how this relationship is affected by food availability. Poecilia reticulata (guppies) of roughly similar size were selected and assembled randomly into populations of 10 guppies assigned to 3 different food availability treatments, and the relative condition index (Kn) of each fish was calculated. We infected 1 individual per group ('source' fish) with Gyrodactyus turnbulli and counted parasites on each fish every other day for 10 days. Epidemic parameters for each population were analysed using generalized linear models. High host Kn-particularly that of the 'source' fish-exerted a positive effect on incidence, peak parasite burden, and the degree of parasite aggregation. Low food availability increased the strength of the associations with peak burden and aggregation. Our findings suggest that host Kn and food availability interact to influence epidemic dynamics, and that the condition of the individual that brings the parasite into the host population has a profound impact on the spread of infection.

  13. Factors influencing women's decisions to purchase specific ...

    African Journals Online (AJOL)

    Keywords: multi-nutrient supplements; survey; children; women's decisions. Factors influencing .... associations between level of education and various factors influencing women's ..... Social marketing improved the use of multivitamin and ...

  14. Factors Influencing Learner Permit Duration

    Directory of Open Access Journals (Sweden)

    Johnathon P. Ehsani

    2016-12-01

    Full Text Available An increasing number of countries are requiring an extended learner permit prior to independent driving. The question of when drivers begin the learner permit period, and how long they hold the permit before advancing to independent licensure has received little research attention. Licensure timing is likely to be related to “push” and “pull” factors which may encourage or inhibit the process. To examine this question, we recruited a sample of 90 novice drivers (49 females and 41 males, average age of 15.6 years soon after they obtained a learner permit and instrumented their vehicles to collect a range of driving data. Participants completed a series of surveys at recruitment related to factors that may influence licensure timing. Two distinct findings emerged from the time-to-event analysis that tested these push and pull factors in relation to licensure timing. The first can be conceptualized as teens’ motivation to drive (push, reflected in a younger age when obtaining a learner permit and extensive pre-permit driving experience. The second finding was teens’ perceptions of their parents’ knowledge of their activities (pull; a proxy for a parents’ attentiveness to their teens’ lives. Teens who reported higher levels of their parents’ knowledge of their activities took longer to advance to independent driving. These findings suggest time-to-licensure may be related to teens’ internal motivation to drive, and the ability of parents to facilitate or impede early licensure.

  15. The influence of host and bacterial genotype on the development of disseminated disease with Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Maxine Caws

    2008-03-01

    Full Text Available The factors that govern the development of tuberculosis disease are incompletely understood. We hypothesized that some strains of Mycobacterium tuberculosis (M. tuberculosis are more capable of causing disseminated disease than others and may be associated with polymorphisms in host genes responsible for the innate immune response to infection. We compared the host and bacterial genotype in 187 Vietnamese adults with tuberculous meningitis (TBM and 237 Vietnamese adults with uncomplicated pulmonary tuberculosis. The host genotype of tuberculosis cases was also compared with the genotype of 392 cord blood controls from the same population. Isolates of M. tuberculosis were genotyped by large sequence polymorphisms. The hosts were defined by polymorphisms in genes encoding Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP and Toll-like receptor-2 (TLR-2. We found a significant protective association between the Euro-American lineage of M. tuberculosis and pulmonary rather than meningeal tuberculosis (Odds ratio (OR for causing TBM 0.395, 95% confidence intervals (C.I. 0.193-0.806, P = 0.009, suggesting these strains are less capable of extra-pulmonary dissemination than others in the study population. We also found that individuals with the C allele of TLR-2 T597C allele were more likely to have tuberculosis caused by the East-Asian/Beijing genotype (OR = 1.57 [95% C.I. 1.15-2.15] than other individuals. The study provides evidence that M. tuberculosis genotype influences clinical disease phenotype and demonstrates, for the first time, a significant interaction between host and bacterial genotypes and the development of tuberculosis.

  16. The Influence of Host and Bacterial Genotype on the Development of Disseminated Disease with Mycobacterium tuberculosis

    Science.gov (United States)

    Caws, Maxine; Thwaites, Guy; Dunstan, Sarah; Hawn, Thomas R.; Thi Ngoc Lan, Nguyen; Thuong, Nguyen Thuy Thuong; Stepniewska, Kasia; Huyen, Mai Nguyet Thu; Bang, Nguyen Duc; Huu Loc, Tran; Gagneux, Sebastien; van Soolingen, Dick; Kremer, Kristin; van der Sande, Marianne; Small, Peter; Thi Hoang Anh, Phan; Chinh, Nguyen Tran; Thi Quy, Hoang; Thi Hong Duyen, Nguyen; Quang Tho, Dau; Hieu, Nguyen T.; Torok, Estee; Hien, Tran Tinh; Dung, Nguyen Huy; Thi Quynh Nhu, Nguyen; Duy, Phan Minh; van Vinh Chau, Nguyen; Farrar, Jeremy

    2008-01-01

    The factors that govern the development of tuberculosis disease are incompletely understood. We hypothesized that some strains of Mycobacterium tuberculosis (M. tuberculosis) are more capable of causing disseminated disease than others and may be associated with polymorphisms in host genes responsible for the innate immune response to infection. We compared the host and bacterial genotype in 187 Vietnamese adults with tuberculous meningitis (TBM) and 237 Vietnamese adults with uncomplicated pulmonary tuberculosis. The host genotype of tuberculosis cases was also compared with the genotype of 392 cord blood controls from the same population. Isolates of M. tuberculosis were genotyped by large sequence polymorphisms. The hosts were defined by polymorphisms in genes encoding Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) and Toll-like receptor-2 (TLR-2). We found a significant protective association between the Euro-American lineage of M. tuberculosis and pulmonary rather than meningeal tuberculosis (Odds ratio (OR) for causing TBM 0.395, 95% confidence intervals (C.I.) 0.193–0.806, P = 0.009), suggesting these strains are less capable of extra-pulmonary dissemination than others in the study population. We also found that individuals with the C allele of TLR-2 T597C allele were more likely to have tuberculosis caused by the East-Asian/Beijing genotype (OR = 1.57 [95% C.I. 1.15–2.15]) than other individuals. The study provides evidence that M. tuberculosis genotype influences clinical disease phenotype and demonstrates, for the first time, a significant interaction between host and bacterial genotypes and the development of tuberculosis. PMID:18369480

  17. Wolbachia as an infectious extrinsic factor manipulating host signalling pathways

    Directory of Open Access Journals (Sweden)

    Ilaria eNegri

    2012-01-01

    Full Text Available Wolbachia pipientis is a widespread endosymbiont of filarial nematodes and arthropods. While in worms the symbiosis is obligate, in arthropods Wolbachia induces several reproductive manipulations (i.e. cytoplasmic incompatibility, parthenogenesis, feminization of genetic males and male-killing in order to increase the number of infected females. These various phenotypic effects may be linked to differences in host physiology, and in particular to endocrine-related processes governing growth, development and reproduction. Indeed, a number of evidences links Wolbachia symbiosis to insulin and ecdysteroid signalling, two multilayered pathways known to work antagonistically, jointly or even independently for the regulation of different molecular networks. At present it is not clear whether Wolbachia manipulates one pathway, thus affecting other related metabolic networks, or if it targets both pathways, even interacting at several points in each of them. Interestingly, in view of the interplay between hormone signalling and epigenetic machinery, a direct influence of the infection on hormonal signalling involving ecdysteroids might be achievable through the manipulation of the host’s epigenetic pathways.

  18. Gut Microbiome and Infant Health: Brain-Gut-Microbiota Axis and Host Genetic Factors

    Science.gov (United States)

    Cong, Xiaomei; Xu, Wanli; Romisher, Rachael; Poveda, Samantha; Forte, Shaina; Starkweather, Angela; Henderson, Wendy A.

    2016-01-01

    The development of the neonatal gut microbiome is influenced by multiple factors, such as delivery mode, feeding, medication use, hospital environment, early life stress, and genetics. The dysbiosis of gut microbiota persists during infancy, especially in high-risk preterm infants who experience lengthy stays in the Neonatal intensive care unit (NICU). Infant microbiome evolutionary trajectory is essentially parallel with the host (infant) neurodevelopmental process and growth. The role of the gut microbiome, the brain-gut signaling system, and its interaction with the host genetics have been shown to be related to both short and long term infant health and bio-behavioral development. The investigation of potential dysbiosis patterns in early childhood is still lacking and few studies have addressed this host-microbiome co-developmental process. Further research spanning a variety of fields of study is needed to focus on the mechanisms of brain-gut-microbiota signaling system and the dynamic host-microbial interaction in the regulation of health, stress and development in human newborns.

  19. Gut Microbiome and Infant Health: Brain-Gut-Microbiota Axis and Host Genetic Factors.

    Science.gov (United States)

    Cong, Xiaomei; Xu, Wanli; Romisher, Rachael; Poveda, Samantha; Forte, Shaina; Starkweather, Angela; Henderson, Wendy A

    2016-09-01

    The development of the neonatal gut microbiome is influenced by multiple factors, such as delivery mode, feeding, medication use, hospital environment, early life stress, and genetics. The dysbiosis of gut microbiota persists during infancy, especially in high-risk preterm infants who experience lengthy stays in the Neonatal intensive care unit (NICU). Infant microbiome evolutionary trajectory is essentially parallel with the host (infant) neurodevelopmental process and growth. The role of the gut microbiome, the brain-gut signaling system, and its interaction with the host genetics have been shown to be related to both short and long term infant health and bio-behavioral development. The investigation of potential dysbiosis patterns in early childhood is still lacking and few studies have addressed this host-microbiome co-developmental process. Further research spanning a variety of fields of study is needed to focus on the mechanisms of brain-gut-microbiota signaling system and the dynamic host-microbial interaction in the regulation of health, stress and development in human newborns.

  20. Nutrition and Helicobacter pylori: Host Diet and Nutritional Immunity Influence Bacterial Virulence and Disease Outcome

    Directory of Open Access Journals (Sweden)

    Kathryn P. Haley

    2016-01-01

    Full Text Available Helicobacter pylori colonizes the stomachs of greater than 50% of the world’s human population making it arguably one of the most successful bacterial pathogens. Chronic H. pylori colonization results in gastritis in nearly all patients; however in a subset of people, persistent infection with H. pylori is associated with an increased risk for more severe disease outcomes including B-cell lymphoma of mucosal-associated lymphoid tissue (MALT lymphoma and invasive adenocarcinoma. Research aimed at elucidating determinants that mediate disease progression has revealed genetic differences in both humans and H. pylori which increase the risk for developing gastric cancer. Furthermore, host diet and nutrition status have been shown to influence H. pylori-associated disease outcomes. In this review we will discuss how H. pylori is able to create a replicative niche within the hostile host environment by subverting and modifying the host-generated immune response as well as successfully competing for limited nutrients such as transition metals by deploying an arsenal of metal acquisition proteins and virulence factors. Lastly, we will discuss how micronutrient availability or alterations in the gastric microbiome may exacerbate negative disease outcomes associated with H. pylori colonization.

  1. Human genome-wide RNAi screen for host factors that modulate intracellular Salmonella growth.

    Science.gov (United States)

    Thornbrough, Joshua M; Hundley, Tom; Valdivia, Raphael; Worley, Micah J

    2012-01-01

    Salmonella enterica is a bacterial pathogen of humans that can proliferate within epithelial cells as well as professional phagocytes of the immune system. While much has been learned about the microbial genes that influence the infectious process through decades of intensive research, relatively little is known about the host factors that affect infection. We performed a genome-wide siRNA screen to identify host genes that Salmonella enterica serovar Typhimurium (S. typhimurium) utilizes to facilitate growth within human epithelial cells. In this screen, with siRNAs targeting every predicted gene in the human genome, we identified 252 new human-host-susceptibility factors (HSFs) for S. typhimurium. We also identified 39 genes whose silencing results in increased intracellular growth of S. typhimurium. The HSFs identified are regulated most centrally by NFκB and associate with each other through an extremely dense network of interactions that center around a group of kinases. Most genes identified were not previously appreciated as playing roles in the intracellular lifecycle of S. enterica. Numerous HSFs identified with interesting characteristics that could play plausible roles in mediating intracellular microbial growth are discussed. Importantly, this study reveals significant overlap between the host network that supports S. typhimurium growth within human epithelial cells and the one that promotes the growth of Mycobacterium tuberculosis within human macrophages. In addition to providing much new information about the molecular mechanisms underlying S. enterica-host cell interplay, all 252 HSFs identified are candidates for new anti-microbial targets for controlling S. enterica infections, and some may provide broad-spectrum anti-microbial activity.

  2. FACTORS INFLUENCING THE EVOLUTION OF YOUTH TRAVEL

    Directory of Open Access Journals (Sweden)

    Student Claudia MOISĂ

    2010-01-01

    Full Text Available Youth travel is an important part of global tourism, consequently, getting to know the evolution of this form of tourism requires an approach of the aspects regarding the permissive and restrictive factors that influence the youth travel dynamic worldwide. In terms of the factors that influence youth travel, we highlighted these two categories of factors (permissive and restrictive and, within each category, we tried to singularize the influence of every factor over youth travel.

  3. Physiological factors influencing capillary growth.

    Science.gov (United States)

    Egginton, S

    2011-07-01

    (1) Angiogenesis (growth of new capillaries from an existing capillary bed) may result from a mismatch in microvascular supply and metabolic demand (metabolic error signal). Krogh examined the distribution and number of capillaries to explore the correlation between O(2) delivery and O(2) consumption. Subsequently, the heterogeneity in angiogenic response within a muscle has been shown to reflect either differences in fibre type composition or mechanical load. However, local control leads to targetted angiogenesis in the vicinity of glycolytic fibre types following muscle stimulation, or oxidative fibres following endurance training, while heterogeneity of capillary spacing is maintained during ontogenetic growth. (2) Despite limited microscopy resolution and lack of specific markers, Krogh's interest in the structure of the capillary wall paved the way for understanding the mechanisms of capillary growth. Angiogenesis may be influenced by the response of perivascular or stromal cells (fibroblasts, macrophages and pericytes) to altered activity, likely acting as a source for chemical signals modulating capillary growth such as vascular endothelial growth factor. In addition, haemodynamic factors such as shear stress and muscle stretch play a significant role in adaptive remodelling of the microcirculation. (3) Most indices of capillarity are highly dependent on fibre size, resulting in possible bias because of scaling. To examine the consequences of capillary distribution, it is therefore helpful to quantify the area of tissue supplied by individual capillaries. This allows the spatial limitations inherent in most models of tissue oxygenation to be overcome generating an alternative approach to Krogh's tissue cylinder, the capillary domain, to improve descriptions of intracellular oxygen diffusion. © 2010 The Author. Acta Physiologica © 2010 Scandinavian Physiological Society.

  4. Fundamental factors determining the nature of parasite aggregation in hosts.

    Directory of Open Access Journals (Sweden)

    Sébastien Gourbière

    Full Text Available The distribution of parasites in hosts is typically aggregated: a few hosts harbour many parasites, while the remainder of hosts are virtually parasite free. The origin of this almost universal pattern is central to our understanding of host-parasite interactions; it affects many facets of their ecology and evolution. Despite this, the standard statistical framework used to characterize parasite aggregation does not describe the processes generating such a pattern. In this work, we have developed a mathematical framework for the distribution of parasites in hosts, starting from a simple statistical description in terms of two fundamental processes: the exposure of hosts to parasites and the infection success of parasites. This description allows the level of aggregation of parasites in hosts to be related to the random variation in these two processes and to true host heterogeneity. We show that random variation can generate an aggregated distribution and that the common view, that encounters and success are two equivalent filters, applies to the average parasite burden under neutral assumptions but it does not apply to the variance of the parasite burden, and it is not true when heterogeneity between hosts is incorporated in the model. We find that aggregation decreases linearly with the number of encounters, but it depends non-linearly on parasite success. We also find additional terms in the variance of the parasite burden which contribute to the actual level of aggregation in specific biological systems. We have derived the formal expressions of these contributions, and these provide new opportunities to analyse empirical data and tackle the complexity of the origin of aggregation in various host-parasite associations.

  5. General Adjustment Influence Factor of Malaysian Construction Expatriates Executives Abroad

    Directory of Open Access Journals (Sweden)

    Zainol Halmi

    2016-01-01

    Full Text Available The success of Malaysian construction companies creates an opportunity to explore abroad. Past studies have shown that the difficulty of expatriates in adjusting to a new environment is the main aspect that leads to failure of assignments. The success in implementing an overseas assignment does not solely depend on an expatriate’s technical expertise. The adjustment issues such as the interaction with the host nationals, and adaptability to the host country’s culture also exert influence on the assignment. The research was conducted to identify the influence of executive expatriate general adjustment on assignment in host countries. The objective of the study was to identify adjustment influence factors relating to general adjustment abroad. Questionnaires were sent to Malaysian expatriate executives. Sixty four Malaysian expatriate executives from Malaysian construction companies overseas were involved in this study. The findings show interaction, social and living environment influences their adjustment during expatriation. Pre-departure training preparation aspects for expatriates is a good step before their departure to host countries.

  6. Host discrimination ability and the influencing factors in Meteorus pulchricornis(Hymenoptera: Braconidae)%斑痣悬茧蜂的寄主辨别能力及其影响因素

    Institute of Scientific and Technical Information of China (English)

    张博; 冯素芳; 黄露; 孟玲; 李保平

    2011-01-01

    To gain insights into mechanisms of superparasitization in Meteorus pulchricornis ( Wesmael) , dual-choice tests were performed to observe preferences of the parasitoid between healthy and parasitized hosts, Prodenia litura ( Fabricius) ( healthy: parasitized 2nd instar larvae =5:5), as affected by parasitization experiences ( three levels; no parasitization experience, parasitization once, superparasitization once) and interval-time (1 -7 d) elapsed after single parasitization; a repeated measures design was exercised to observe oviposition stings during three successive visits to host patches of different quality as measured by the proportion of parasitized hosts (2,5, and 8 parasitized hosts among 10 hosts, respectively) in a patch. The analysis results of preferences showed that the probability of superparasitization was significantly affected by parasitization experiences of parasitoids and time interval after single parasitization, and it was decreased with the time interval and parasitization experience. The Cox model was fitted to the discrimination time prior to oviposition, and the results indicated that the hazard of superparasitization diminished both with extending of the interval time after single parasitization and with the parasitoid experience of superparasitization. The trials on parasitization during visits to host-patches of different qualities showed that the number of oviposition stings increased with the quality of host patch. The results suggest that M. Pulchricomis can discriminate not only parasitized hosts, but also host patches with single parasitized hosts.%为评价斑痣悬茧蜂Meteorus pulchricornis(Wesmael)的寄主辨别能力及其影响因素,采用双选试验(斜纹夜蛾2龄寄主幼虫,健康:被寄生=5:5),观察了寄生经历(无寄生经历、有1次寄生经历、有1次过奇生经历)和寄主被首次寄生后的间隔时间(1-7 d)对斑痣悬茧蜂在健康寄主和被寄生寄主之间的选择;为探究斑痣

  7. The Influence of Learning on Host Plant Preference in a Significant Phytopathogen Vector, Diaphorina citri.

    Science.gov (United States)

    Stockton, Dara G; Martini, Xavier; Patt, Joseph M; Stelinski, Lukasz L

    2016-01-01

    Although specialist herbivorous insects are guided by innate responses to host plant cues, host plant preference may be influenced by experience and is not dictated by instinct alone. The effect of learning on host plant preference was examined in the Asian citrus psyllid, Diaphorina citri; vector of the causal agent of citrus greening disease or huanglongbing. We investigated: a) whether development on specific host plant species influenced host plant preference in mature D. citri; and b) the extent of associative learning in D. citri in the form of simple and compound conditioning. Learning was measured by cue selection in a 2-choice behavioral assay and compared to naïve controls. Our results showed that learned responses in D. citri are complex and diverse. The developmental host plant species influenced adult host plant preference, with female psyllids preferring the species on which they were reared. However, such preferences were subject to change with the introduction of an alternative host plant within 24-48 hrs, indicating a large degree of experience-dependent response plasticity. Additionally, learning occurred for multiple sensory modalities where novel olfactory and visual environmental cues were associated with the host plant. However, males and females displayed differing discriminatory abilities. In compound conditioning tasks, males exhibited recognition of a compound stimulus alone while females were capable of learning the individual components. These findings suggest D. citri are dynamic animals that demonstrate host plant preference based on developmental and adult experience and can learn to recognize olfactory and visual host plant stimuli in ways that may be sex specific. These experience-based associations are likely used by adults to locate and select suitable host plants for feeding and reproduction and may suggest the need for more tailored lures and traps, which reflect region-specific cultivars or predominate Rutaceae in the area

  8. The Influence of Learning on Host Plant Preference in a Significant Phytopathogen Vector, Diaphorina citri.

    Directory of Open Access Journals (Sweden)

    Dara G Stockton

    Full Text Available Although specialist herbivorous insects are guided by innate responses to host plant cues, host plant preference may be influenced by experience and is not dictated by instinct alone. The effect of learning on host plant preference was examined in the Asian citrus psyllid, Diaphorina citri; vector of the causal agent of citrus greening disease or huanglongbing. We investigated: a whether development on specific host plant species influenced host plant preference in mature D. citri; and b the extent of associative learning in D. citri in the form of simple and compound conditioning. Learning was measured by cue selection in a 2-choice behavioral assay and compared to naïve controls. Our results showed that learned responses in D. citri are complex and diverse. The developmental host plant species influenced adult host plant preference, with female psyllids preferring the species on which they were reared. However, such preferences were subject to change with the introduction of an alternative host plant within 24-48 hrs, indicating a large degree of experience-dependent response plasticity. Additionally, learning occurred for multiple sensory modalities where novel olfactory and visual environmental cues were associated with the host plant. However, males and females displayed differing discriminatory abilities. In compound conditioning tasks, males exhibited recognition of a compound stimulus alone while females were capable of learning the individual components. These findings suggest D. citri are dynamic animals that demonstrate host plant preference based on developmental and adult experience and can learn to recognize olfactory and visual host plant stimuli in ways that may be sex specific. These experience-based associations are likely used by adults to locate and select suitable host plants for feeding and reproduction and may suggest the need for more tailored lures and traps, which reflect region-specific cultivars or predominate

  9. A Single Residue in Ebola Virus Receptor NPC1 Influences Cellular Host Range in Reptiles.

    Science.gov (United States)

    Ndungo, Esther; Herbert, Andrew S; Raaben, Matthijs; Obernosterer, Gregor; Biswas, Rohan; Miller, Emily Happy; Wirchnianski, Ariel S; Carette, Jan E; Brummelkamp, Thijn R; Whelan, Sean P; Dye, John M; Chandran, Kartik

    2016-01-01

    Filoviruses are the causative agents of an increasing number of disease outbreaks in human populations, including the current unprecedented Ebola virus disease (EVD) outbreak in western Africa. One obstacle to controlling these epidemics is our poor understanding of the host range of filoviruses and their natural reservoirs. Here, we investigated the role of the intracellular filovirus receptor, Niemann-Pick C1 (NPC1) as a molecular determinant of Ebola virus (EBOV) host range at the cellular level. Whereas human cells can be infected by EBOV, a cell line derived from a Russell's viper (Daboia russellii) (VH-2) is resistant to infection in an NPC1-dependent manner. We found that VH-2 cells are resistant to EBOV infection because the Russell's viper NPC1 ortholog bound poorly to the EBOV spike glycoprotein (GP). Analysis of panels of viper-human NPC1 chimeras and point mutants allowed us to identify a single amino acid residue in NPC1, at position 503, that bidirectionally influenced both its binding to EBOV GP and its viral receptor activity in cells. Significantly, this single residue change perturbed neither NPC1's endosomal localization nor its housekeeping role in cellular cholesterol trafficking. Together with other recent work, these findings identify sequences in NPC1 that are important for viral receptor activity by virtue of their direct interaction with EBOV GP and suggest that they may influence filovirus host range in nature. Broader surveys of NPC1 orthologs from vertebrates may delineate additional sequence polymorphisms in this gene that control susceptibility to filovirus infection. IMPORTANCE Identifying cellular factors that determine susceptibility to infection can help us understand how Ebola virus is transmitted. We asked if the EBOV receptor Niemann-Pick C1 (NPC1) could explain why reptiles are resistant to EBOV infection. We demonstrate that cells derived from the Russell's viper are not susceptible to infection because EBOV cannot bind to

  10. Demotivating factors influencing rubber production workers

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Iravani

    2012-01-01

    Full Text Available Motivation is one of the most important factors influencing workers' productivity. An increase in workers' motivation could add more value to organizations' structure and influence the profitability, significantly. In this paper, we study different factors on demotivating workers using questionnaire consist of various questions. The questionnaire is distributed among some employees who work for rubber production units located in Esfahan, Iran. The results of this survey indicate that discrimination on annual job compensation, entrusting responsibilities and unpleasant relationship with family partner are some of the most important factors influencing employees' motivation. While financial factors play important role on increasing employees' motivation, non-financial factors are considered more important.

  11. Influence of Azospirillum spp. on the nitrogen supply of a gramineous host.

    NARCIS (Netherlands)

    Christiansen-Weniger, C.

    1991-01-01

    The main objectives of this study were to identify factors that control the behaviour of Azospirillum in the rhizosphere of a gramineous plant in order to be able to optimize the association between the bacteria and the host plants in terms of nitrogen supply to the host.Plant produced growth substa

  12. Emerging functions as host cell factors - an encyclopedia of annexin-pathogen interactions.

    Science.gov (United States)

    Kuehnl, Alexander; Musiol, Agnes; Raabe, Carsten A; Rescher, Ursula

    2016-10-01

    Emerging infectious diseases and drug-resistant infectious agents call for the development of innovative antimicrobial strategies. With pathogenicity now considered to arise from the complex and bi-directional interplay between a microbe and the host, host cell factor targeting has emerged as a promising approach that might overcome the limitations of classical antimicrobial drug development and could open up novel and efficient therapeutic strategies. Interaction with and modulation of host cell membranes is a recurrent theme in the host-microbe relationship. In this review, we provide an overview of what is currently known about the role of the Ca2+ dependent, membrane-binding annexin protein family in pathogen-host interactions, and discuss their emerging functions as host cell derived auxiliary proteins in microbe-host interactions and host cell targets.

  13. DMPD: Macrophage migration inhibitory factor and host innate immune responses tomicrobes. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14620137 Macrophage migration inhibitory factor and host innate immune responses to...microbes. Calandra T. Scand J Infect Dis. 2003;35(9):573-6. (.png) (.svg) (.html) (.csml) Show Macrophage migration... inhibitory factor and host innate immune responses tomicrobes. PubmedID 14620137 Title Macrophage migration

  14. KAP1 Is a Host Restriction Factor That Promotes Human Adenovirus E1B-55K SUMO Modification

    DEFF Research Database (Denmark)

    Bürck, Carolin; Mund, Andreas; Berscheminski, Julia

    2016-01-01

    characterized, but represent a decisive moment in establishing a productive infection. Here, we identify a novel host viral restriction factor, KAP1. This heterochromatin associated transcription factor regulates the dynamic organization of host chromatin structure via its ability to influence epigenetic marks...... epigenetic gene silencing and to promote SUMO modification of E1B-55K by a so far unknown mechanism. IMPORTANCE: Here we describe a novel cellular restriction factor for Human Adenovirus (HAdV) that sheds light on very early modulation processes in viral infection. We reported that chromatin formation...... and cellular SWI/SNF chromatin remodeling play a key role in HAdV transcriptional regulation (1-4). We observed that the cellular chromatin-associated factor, and epigenetic reader SPOC1 represses HAdV infection and gene expression. Here, we illustrate the role of the SPOC1 interacting factor KAP1 during...

  15. The influence of interspecific competition and host preference on the phylogeography of two African ixodid tick species.

    Science.gov (United States)

    Cangi, Nídia; Horak, Ivan G; Apanaskevich, Dmitry A; Matthee, Sonja; das Neves, Luís C B G; Estrada-Peña, Agustín; Matthee, Conrad A

    2013-01-01

    A comparative phylogeographic study on two economically important African tick species, Amblyomma hebraeum and Hyalomma rufipes was performed to test the influence of host specificity and host movement on dispersion. Pairwise AMOVA analyses of 277 mtDNA COI sequences supported significant population differentiation among the majority of sampling sites. The geographic mitochondrial structure was not supported by nuclear ITS-2 sequencing, probably attributed to a recent divergence. The three-host generalist, A. hebraeum, showed less mtDNA geographic structure, and a lower level of genetic diversity, while the more host-specific H. rufipes displayed higher levels of population differentiation and two distinct mtDNA assemblages (one predominantly confined to South Africa/Namibia and the other to Mozambique and East Africa). A zone of overlap is present in southern Mozambique. A mechanistic climate model suggests that climate alone cannot be responsible for the disruption in female gene flow. Our findings furthermore suggest that female gene dispersal of ticks is more dependent on the presence of juvenile hosts in the environment than on the ability of adult hosts to disperse across the landscape. Documented interspecific competition between the juvenile stages of H. rufipes and H. truncatum is implicated as a contributing factor towards disrupting gene flow between the two southern African H. rufipes genetic assemblages.

  16. The influence of interspecific competition and host preference on the phylogeography of two African ixodid tick species.

    Directory of Open Access Journals (Sweden)

    Nídia Cangi

    Full Text Available A comparative phylogeographic study on two economically important African tick species, Amblyomma hebraeum and Hyalomma rufipes was performed to test the influence of host specificity and host movement on dispersion. Pairwise AMOVA analyses of 277 mtDNA COI sequences supported significant population differentiation among the majority of sampling sites. The geographic mitochondrial structure was not supported by nuclear ITS-2 sequencing, probably attributed to a recent divergence. The three-host generalist, A. hebraeum, showed less mtDNA geographic structure, and a lower level of genetic diversity, while the more host-specific H. rufipes displayed higher levels of population differentiation and two distinct mtDNA assemblages (one predominantly confined to South Africa/Namibia and the other to Mozambique and East Africa. A zone of overlap is present in southern Mozambique. A mechanistic climate model suggests that climate alone cannot be responsible for the disruption in female gene flow. Our findings furthermore suggest that female gene dispersal of ticks is more dependent on the presence of juvenile hosts in the environment than on the ability of adult hosts to disperse across the landscape. Documented interspecific competition between the juvenile stages of H. rufipes and H. truncatum is implicated as a contributing factor towards disrupting gene flow between the two southern African H. rufipes genetic assemblages.

  17. The correlated factors of the uneven performances of the CDM host countries

    Science.gov (United States)

    Zhu, Jinshan

    2012-03-01

    The Kyoto Protocol’s Clean Development Mechanism (CDM) has experienced a rapid growth. Up to 2010, 2763 projects have been registered, standing for about 433 million ton CO2 equivalent (CO2-eq.) of annual carbon credits. However, the performances of CDM host countries are remarkably unbalanced. Previous literature suggested that economic and investment conditions, energy intensity, energy structure, the share of annual carbon credits from high global warming potential (GWP) green house gas (GHG), capacity and institutional buildings of domestic CDM governance can play important roles in promoting CDM. This quantitative analysis shows that domestic economic and investment conditions are the most decisive factors determining the performance of the CDM host countries. Additionally, the influence of carbon intensity of energy consumption is relatively modest, and energy intensity of GDP as well as the share of annual carbon credits from high GWP GHG is less significant. Moreover, several leading CDM countries are not as successful as they seem to be, when the influences of their vast territories, distinguished economic and investment conditions are excluded. Therefore, to simply transplant the CDM governances of these countries can hardly guarantee that other countries will boost their carbon credit outputs.

  18. Structural basis for antagonizing a host restriction factor by C7 family of poxvirus host-range proteins.

    Science.gov (United States)

    Meng, Xiangzhi; Krumm, Brian; Li, Yongchao; Deng, Junpeng; Xiang, Yan

    2015-12-01

    Human sterile alpha motif domain-containing 9 (SAMD9) protein is a host restriction factor for poxviruses, but it can be overcome by some poxvirus host-range proteins that share homology with vaccinia virus C7 protein. To understand the mechanism of action for this important family of host-range factors, we determined the crystal structures of C7 and myxoma virus M64, a C7 family member that is unable to antagonize SAMD9. Despite their different functions and only 23% sequence identity, the two proteins have very similar overall structures, displaying a previously unidentified fold comprised of a compact 12-stranded antiparallel β-sandwich wrapped in two short α helices. Extensive structure-guided mutagenesis of C7 identified three loops clustered on one edge of the β sandwich as critical for viral replication and binding with SAMD9. The loops are characterized with functionally important negatively charged, positively charged, and hydrophobic residues, respectively, together forming a unique "three-fingered molecular claw." The key residues of the claw are not conserved in two C7 family members that do not antagonize SAMD9 but are conserved in distantly related C7 family members from four poxvirus genera that infect diverse mammalian species. Indeed, we found that all in the latter group of proteins bind SAMD9. Taken together, our data indicate that diverse mammalian poxviruses use a conserved molecular claw in a C7-like protein to target SAMD9 and overcome host restriction.

  19. The influence of social structure, habitat, and host traits on the transmission of Escherichia coli in wild elephants.

    Directory of Open Access Journals (Sweden)

    Patrick I Chiyo

    Full Text Available Social structure is proposed to influence the transmission of both directly and environmentally transmitted infectious agents. However in natural populations, many other factors also influence transmission, including variation in individual susceptibility and aspects of the environment that promote or inhibit exposure to infection. We used a population genetic approach to investigate the effects of social structure, environment, and host traits on the transmission of Escherichia coli infecting two populations of wild elephants: one in Amboseli National Park and another in Samburu National Reserve, Kenya. If E. coli transmission is strongly influenced by elephant social structure, E. coli infecting elephants from the same social group should be genetically more similar than E. coli sampled from members of different social groups. However, we found no support for this prediction. Instead, E. coli was panmictic across social groups, and transmission patterns were largely dominated by habitat and host traits. For instance, habitat overlap between elephant social groups predicted E. coli genetic similarity, but only in the relatively drier habitat of Samburu, and not in Amboseli, where the habitat contains large, permanent swamps. In terms of host traits, adult males were infected with more diverse haplotypes, and males were slightly more likely to harbor strains with higher pathogenic potential, as compared to adult females. In addition, elephants from similar birth cohorts were infected with genetically more similar E. coli than elephants more disparate in age. This age-structured transmission may be driven by temporal shifts in genetic structure of E. coli in the environment and the effects of age on bacterial colonization. Together, our results support the idea that, in elephants, social structure often will not exhibit strong effects on the transmission of generalist, fecal-oral transmitted bacteria. We discuss our results in the context of

  20. The influence of social structure, habitat, and host traits on the transmission of Escherichia coli in wild elephants.

    Science.gov (United States)

    Chiyo, Patrick I; Grieneisen, Laura E; Wittemyer, George; Moss, Cynthia J; Lee, Phyllis C; Douglas-Hamilton, Iain; Archie, Elizabeth A

    2014-01-01

    Social structure is proposed to influence the transmission of both directly and environmentally transmitted infectious agents. However in natural populations, many other factors also influence transmission, including variation in individual susceptibility and aspects of the environment that promote or inhibit exposure to infection. We used a population genetic approach to investigate the effects of social structure, environment, and host traits on the transmission of Escherichia coli infecting two populations of wild elephants: one in Amboseli National Park and another in Samburu National Reserve, Kenya. If E. coli transmission is strongly influenced by elephant social structure, E. coli infecting elephants from the same social group should be genetically more similar than E. coli sampled from members of different social groups. However, we found no support for this prediction. Instead, E. coli was panmictic across social groups, and transmission patterns were largely dominated by habitat and host traits. For instance, habitat overlap between elephant social groups predicted E. coli genetic similarity, but only in the relatively drier habitat of Samburu, and not in Amboseli, where the habitat contains large, permanent swamps. In terms of host traits, adult males were infected with more diverse haplotypes, and males were slightly more likely to harbor strains with higher pathogenic potential, as compared to adult females. In addition, elephants from similar birth cohorts were infected with genetically more similar E. coli than elephants more disparate in age. This age-structured transmission may be driven by temporal shifts in genetic structure of E. coli in the environment and the effects of age on bacterial colonization. Together, our results support the idea that, in elephants, social structure often will not exhibit strong effects on the transmission of generalist, fecal-oral transmitted bacteria. We discuss our results in the context of social, environmental

  1. Deconstructing the Bat Skin Microbiome: Influences of the Host and the Environment

    Directory of Open Access Journals (Sweden)

    Christine V Avena

    2016-11-01

    Full Text Available Bats are geographically widespread and play an important role in many ecosystems, but relatively little is known about the ecology of their associated microbial communities and the role microbial taxa play in bat health, development, and evolution. Moreover, few vertebrate animal skin microbiomes have been comprehensively assessed, and thus characterizing the bat skin microbiome will yield valuable insight into the variability of vertebrate skin microbiomes as a whole. The recent emergence of the skin fungal disease white-nose syndrome highlights the potentially important role bat skin microbial communities could play in bat health. Understanding the determinant of bat skin microbial communities could provide insight into important factors allowing individuals to persist with disease. We collected skin swabs from a total of 11 bat species from the eastern United States (n=45 and Colorado (n=119, as well as environmental samples (n=38 from a subset of sites, and used 16S rRNA marker gene sequencing to observe bacterial communities. In addition, we conducted a literature survey to compare the skin microbiome across vertebrate groups, including the bats presented in this study. Host species, region, and site were all significant predictors of the variability across bat skin bacterial communities. Many bacterial taxa were found both on bats and in the environment. However, some bacterial taxa had consistently greater relative abundances on bat skin relative to their environments. Bats shared many of their abundant taxa with other vertebrates, but also hosted unique bacterial lineages such as the class Thermoleophilia (Actinobacteria. A strong effect of site on the bat skin microbiome indicates that the environment very strongly influences what bacteria are present on bat skin. Bat skin microbiomes are largely composed of site-specific microbiota, but there do appear to be important host-specific taxa. How this translates to differences in host

  2. Psychological Factors Influencing Consumer Behaviour

    OpenAIRE

    Vainikka, Bianca

    2015-01-01

    This paper’s aim is to provide an in-depth elucidation of the many aspects that influence consumer behaviour. The study of consumer behaviour emphasizes the “why” and “how” questions involved in decision making and buying behaviour. This exciting field visits a dynamic blend of themes of consumer marketing strategies, psychology and behavioural discipline. Consumer behaviour in this day and age is highly applicable to modern society as it is an integral part of our everyday lives. This paper ...

  3. Targeting Host Factors to Treat West Nile and Dengue Viral Infections

    Directory of Open Access Journals (Sweden)

    Manoj N. Krishnan

    2014-02-01

    Full Text Available West Nile (WNV and Dengue (DENV viruses are major arboviral human pathogens belonging to the genus Flavivirus. At the current time, there are no approved prophylactics (e.g., vaccines or specific therapeutics available to prevent or treat human infections by these pathogens. Due to their minimal genome, these viruses require many host molecules for their replication and this offers a therapeutic avenue wherein host factors can be exploited as treatment targets. Since several host factors appear to be shared by many flaviviruses the strategy may result in pan-flaviviral inhibitors and may also attenuate the rapid emergence of drug resistant mutant viruses. The scope of this strategy is greatly enhanced by the recent en masse identification of host factors impacting on WNV and DENV infection. Excellent proof-of-principle experimental demonstrations for host-targeted control of infection and infection-induced pathogenesis have been reported for both WNV and DENV. These include exploiting not only those host factors supporting infection, but also targeting host processes contributing to pathogenesis and innate immune responses. While these early studies validated the host-targeting approach, extensive future investigations spanning a range of aspects are needed for a successful deployment in humans.

  4. The Golgi associated ERI3 is a Flavivirus host factor

    Science.gov (United States)

    Ward, Alex Michael; Calvert, Meredith E. K.; Read, Leah R.; Kang, Seokyoung; Levitt, Brandt E.; Dimopoulos, George; Bradrick, Shelton S.; Gunaratne, Jayantha; Garcia-Blanco, Mariano A.

    2016-01-01

    Dengue virus (DENV) is a mosquito-borne Flavivirus classified into four serotypes (DENV-1-4) that causes Dengue fever (DF), Dengue hemorrhagic Fever (DHF) or Dengue shock syndrome (DSS). An estimated 390 million people are at risk for infection with DENV and there are no effective vaccines or therapeutics. We utilized RNA chromatography coupled with quantitative mass spectrometry (qMS) to identify host RNA binding proteins (RBPs) that interact with DENV-2 RNA. We identified ERI3 (also PRNPIP and PINT1), a putative 3′–5′ RNA exonuclease, which preferentially associates with DENV-2 genomic RNA via interactions with dumbbell structures in the 3′ UTR. ERI3 is required for accumulation of DENV-2 genomic RNA and production of infectious particles. Furthermore, the mosquito homologue of ERI3 is required for DENV-2 replication in adult Aedes aegypti mosquitos implying that the requirement for ERI3 is conserved in both DENV hosts. In human cells ERI3 localizes to the Golgi in uninfected cells, but relocalizes near sites of DENV-2 replication in infected cells. ERI3 is not required for maintaining DENV-2 RNA stability or translation of the viral polyprotein, but is required for viral RNA synthesis. Our results define a specific role for ERI3 and highlight the importance of Golgi proteins in DENV-2 replication. PMID:27682269

  5. Thymic Output: Influence Factors and Molecular Mechanism

    Institute of Scientific and Technical Information of China (English)

    Rong Jin; Jun Zhang; Weifeng Chen

    2006-01-01

    Thymus is a primary lymphoid organ, able to generate mature T cells that eventually colonize secondary lymphoid organs, and is therefore essential for peripheral T cell renewal. Recent data showed that normal thymocyte export can be altered by several influence factors including several chemokines,sphingosinel-phosphate (S1P),transcription factors such as Foxjl, Kruppel-like transcription factor 2 (KLF2) and antigen stimulation, etc. In this review, we summarized the recent reports about study strategies, influence factors and possible molecular mechanisms in thymic output.

  6. 31. FACTORS INFLUENCING UTILIZATION OF INTERMITTENT ...

    African Journals Online (AJOL)

    Esem

    treatment of malaria during pregnancy(IPTp), effective IPTp service utilization ... effective case management of malaria. Despite the ... Factors influencing IPTp utilization identified in the study included; educational status of a woman,. Medical ...

  7. Home Environmental Factors Influencing Performance and Progress ...

    African Journals Online (AJOL)

    ... Factors Influencing Performance and Progress of Primary School Pupils in ... found that parents' educational level and income level have a bearing on school ... on school progress and performance, however; home language did play a role.

  8. Factors Influencing Self Employment Media Service Providers ...

    African Journals Online (AJOL)

    Factors Influencing Self Employment Media Service Providers among Tertiary ... role stereotype and common business practices on media self employment in ... Sex, Psycho-social Characteristics, self Employment, Providing Media Services.

  9. Age-Related Factors That Influence Fertility

    Science.gov (United States)

    ... can be found at the NICHD Pregnancy Loss topic page . Committee on Gynecologic Practice of American College of ... 2012, from http://www.nichd.nih.gov/health/topics/pregnancyloss/researchinfo/Pages/default.aspx [top] « Lifestyle Factors That Influence Fertility ...

  10. Factors that negatively influence consumption of traditionally ...

    African Journals Online (AJOL)

    Factors that negatively influence consumption of traditionally fermented milk ... of sub-Saharan Africa and a number of health benefits to human beings are ... Key words: Mursik, Lactic acid bacteria (LAB), probiotic, Preschoolers, Focus group

  11. FACTORS INFLUENCING THE SELECTION OF DENTAL NURSING ...

    African Journals Online (AJOL)

    drclement

    FACTORS INFLUENCING THE SELECTION OF DENTAL NURSING AS A. PROFESSION ... Colleges of Health Technology undergoing external ... questionnaire requested information on age ... individual with good communication skills and ...

  12. Factors that Influence Adolescents to Smoke.

    Science.gov (United States)

    Smith, Karen H.; Stutts, Mary Ann

    1999-01-01

    A survey of the factors that influence adolescents (n=246) to smoke found that family smoking behavior, peer pressure, and prior beliefs were more important in predicting smoking level than were advertising and antismoking information. (Author/JOW)

  13. FACTORS INFLUENCING SUSTAINED MANAGERIAL EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Alexandru Marius RIZESCU

    2017-04-01

    Full Text Available The concept of effectiveness is learnable in economic theory and practice with various forms of manifestation of the results obtained by the managers, such as profitability, the productivity of factors of production, capital efficiency, cost savings, etc. Regarded as the organizing principle and driving activity in the market economy, it has a much richer content and also favorable results of generalizing all derived by managers. Choosing effective in meeting needs with limited resources or powerlessness to maximize resource needs under restrains, are expressions through which efficiency is situated at the heart of economic theory and practice.

  14. ENERGY EFFICIENCY. TRENDS AND INFLUENCE FACTORS

    Directory of Open Access Journals (Sweden)

    Zizi GOSCHIN

    2006-12-01

    Full Text Available Energy efficiency is correlated with many factors of influence: Gross National Income per capita, energy imports (% of energy use, renewable combustible and waste (% of total, energy use per capita, services as % of GDP and others. In this paper we are testing a model of piecewise linear regression with breakpoint in order to measure the influence of these factors on the variation of GDP per unit of energy use in Europe in the year 2003.

  15. Host age, social group, and habitat type influence the gut microbiota of wild ring-tailed lemurs (Lemur catta).

    Science.gov (United States)

    Bennett, Genevieve; Malone, Matthew; Sauther, Michelle L; Cuozzo, Frank P; White, Bryan; Nelson, Karen E; Stumpf, Rebecca M; Knight, Rob; Leigh, Steven R; Amato, Katherine R

    2016-08-01

    The gut microbiota contributes to host health by maintaining homeostasis, increasing digestive efficiency, and facilitating the development of the immune system. The composition of the gut microbiota can change dramatically within and between individuals of a species as a result of diet, age, or habitat. Therefore, understanding the factors determining gut microbiota diversity and composition can contribute to our knowledge of host ecology as well as to conservation efforts. Here we use high-throughput sequencing to describe variation in the gut microbiota of the endangered ring-tailed lemur (Lemur catta) at the Bezà Mahafaly Special Reserve (BMSR) in southwestern Madagascar. Specifically, we measured the diversity and composition of the gut microbiota in relation to social group, age, sex, tooth wear and loss, and habitat disturbance. While we found no significant variation in the diversity of the ring-tailed lemur gut microbiota in response to any variable tested, the taxonomic composition of the gut microbiota was influenced by social group, age, and habitat disturbance. However, effect sizes were small and appear to be driven by the presence or absence of relatively low abundance taxa. These results suggest that habitat disturbance may not impact the lemur gut microbiota as strongly as it impacts the gut microbiota of other primate species, highlighting the importance of distinct host ecological and physiological factors on host-gut microbe relationships. Am. J. Primatol. 78:883-892, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  16. The influence of host and bacterial genotype on the development of disseminated disease with Mycobacterium tuberculosis.

    OpenAIRE

    2008-01-01

    The factors that govern the development of tuberculosis disease are incompletely understood. We hypothesized that some strains of Mycobacterium tuberculosis (M. tuberculosis) are more capable of causing disseminated disease than others and may be associated with polymorphisms in host genes responsible for the innate immune response to infection. We compared the host and bacterial genotype in 187 Vietnamese adults with tuberculous meningitis (TBM) and 237 Vietnamese adults with uncomplicated p...

  17. Virulence Factors and Strategies of Leptopilina spp.: Selective Responses in Drosophila Hosts

    Science.gov (United States)

    Lee, Mark J.; Kalamarz, Marta E.; Paddibhatla, Indira; Small, Chiyedza; Rajwani, Roma; Govind, Shubha

    2010-01-01

    To ensure survival, parasitic wasps of Drosophila have evolved strategies to optimize host development to their advantage. They also produce virulence factors that allow them to overcome or evade host defense. Wasp infection provokes cellular and humoral defense reactions, resulting in alteration in gene expression of the host. The activation of these reactions is controlled by conserved mechanisms shared by other invertebrate and vertebrate animals. Application of genomics and bioinformatics approaches is beginning to reveal comparative host gene expression changes after infection by different parasitic wasps. We analyze this comparison in the context of host physiology and immune cells, as well as the biology of the venom factors that wasps introduce into their hosts during oviposition. We compare virulence strategies of Leptopilina boulardi and L. heterotoma, in relation to genome-wide changes in gene expression in the fly hosts after infection. This analysis highlights fundamental differences in the changes that the host undergoes in its immune and general physiology in response to the two parasitic wasps. Such a comparative approach has the potential of revealing mechanisms governing the evolution of pathogenicity and how it impacts host range. PMID:19773069

  18. Variation properties of ionospheric eclipse factor and ionospheric influence factor

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chunmei; YUAN Yunbin; OU Jikun; CHEN Jinping

    2005-01-01

    The concepts and calculation methods of ionospheric eclipse factor (IEF) and ionospheric influence factor (IFF) are further illustrated. The temporal and spacial variation properties of IEF and IFF are studied, which shows that the properties are influenced by the geographic position and season. The possibility of improving the precision of using GPS data to determine ionospheric delay based on the above variation properties is also analysed.

  19. Yersinia virulence factors - a sophisticated arsenal for combating host defences.

    Science.gov (United States)

    Atkinson, Steve; Williams, Paul

    2016-01-01

    The human pathogens Yersinia pseudotuberculosis and Yersinia enterocolitica cause enterocolitis, while Yersinia pestis is responsible for pneumonic, bubonic, and septicaemic plague. All three share an infection strategy that relies on a virulence factor arsenal to enable them to enter, adhere to, and colonise the host while evading host defences to avoid untimely clearance. Their arsenal includes a number of adhesins that allow the invading pathogens to establish a foothold in the host and to adhere to specific tissues later during infection. When the host innate immune system has been activated, all three pathogens produce a structure analogous to a hypodermic needle. In conjunction with the translocon, which forms a pore in the host membrane, the channel that is formed enables the transfer of six 'effector' proteins into the host cell cytoplasm. These proteins mimic host cell proteins but are more efficient than their native counterparts at modifying the host cell cytoskeleton, triggering the host cell suicide response. Such a sophisticated arsenal ensures that yersiniae maintain the upper hand despite the best efforts of the host to counteract the infecting pathogen.

  20. Yersinia virulence factors - a sophisticated arsenal for combating host defences

    Science.gov (United States)

    Atkinson, Steve; Williams, Paul

    2016-01-01

    The human pathogens Yersinia pseudotuberculosis and Yersinia enterocolitica cause enterocolitis, while Yersinia pestis is responsible for pneumonic, bubonic, and septicaemic plague. All three share an infection strategy that relies on a virulence factor arsenal to enable them to enter, adhere to, and colonise the host while evading host defences to avoid untimely clearance. Their arsenal includes a number of adhesins that allow the invading pathogens to establish a foothold in the host and to adhere to specific tissues later during infection. When the host innate immune system has been activated, all three pathogens produce a structure analogous to a hypodermic needle. In conjunction with the translocon, which forms a pore in the host membrane, the channel that is formed enables the transfer of six ‘effector’ proteins into the host cell cytoplasm. These proteins mimic host cell proteins but are more efficient than their native counterparts at modifying the host cell cytoskeleton, triggering the host cell suicide response. Such a sophisticated arsenal ensures that yersiniae maintain the upper hand despite the best efforts of the host to counteract the infecting pathogen. PMID:27347390

  1. FACTORS INFLUENCING COMPOSTING POULTRY WASTE

    Directory of Open Access Journals (Sweden)

    Michał Kopeć

    2015-11-01

    Full Text Available Organic recycling of waste, taking into account sanitary safety, should be a fundamental method for recovering the nutrients present in the waste for plants and organic matter. It also refers to by-products of animal origin, which are not intended for consumption by humans. In the present research , composting of hydrated poultry slaughterhouse waste with maize straw was carried out. A combination with fodder yeast and post-cellulose lime was also introduced, which modified chemical and physico-chemical properties of the mixtures. The experiment was carried out by recording the biomass temperature for 110 days in 1.2×1.0×0.8 m reactors with perforated bottoms enabling active aeration. The following parameters were taken into consideration in the composted material: carbon, nitrogen, sulfur, respiratory activity, microorganisms, fractions of compost obtained after washing on sieves. Small amounts of fodder yeast favoured the development of microorganisms and caused a sanitary risk in the final product. At the initial stage, the temperature of raw compost in that object was several degrees lower than in the case of the composted mass without yeast addition. The addition of post-cellulose lime at ratios 6.5:1:6.5 (maize straw: poultry slaughterhouse waste: post-cellulose lime caused a change in the time of microbiological activity, and led to its inhibition in the final process. In comparison to objects with poultry waste, the highest degree of hygienization was found in the compost with post-cellulose lime (with pH close to neutral. By adjusting the ratios of substrates we can influence the microbiological activity, but the amounts of individual substrates should be determined taking into account the quality of the obtained compost.

  2. Factors Influencing the Quality of Mobile Applications

    Directory of Open Access Journals (Sweden)

    Alin ZAMFIROIU

    2014-01-01

    Full Text Available Mobile applications are becoming increasingly used. Mobile devices are becoming indispensable for the user. In the material are claiming the sales of mobile devices internationally and the use of mobile applications compared to traditional internet use on desktop systems for the United States. Are presented influences the quality of mobile applications and based on these influencing factors built a model of choice for optimal application of mobile applications and traditional desktop application. At the end of the material presented methods to increase quality by tracking the influence factors during the development of mobile applications.

  3. Heterogeneity shapes invasion: host size and environment influence susceptibility to a nonnative pathogen.

    Science.gov (United States)

    Kauffman, Matthew J; Jules, Erik S

    2006-02-01

    Theoretical study of invasion dynamics has suggested that spatial heterogeneity should strongly influence the rate and extent of spreading organisms. However, empirical support for this prediction is scant, and the importance of understanding heterogeneity for real-world systems has remained ambiguous. This study quantified the influence of host and environmental heterogeneity on the dynamics of a 19-year disease invasion by the exotic and fatal pathogen, Phytophthora lateralis, within a stream population of its host tree, Port Orford cedar (Chamaecyparis lawsoniana). Using dendrochronology, we reconstructed the invasion history along a 1350-m length of infected stream, which serves as the only route of pathogen dispersal. Contrary to theoretical predictions, the temporal progression of the disease invasion was not related to a host's downstream spatial position, but instead was determined by two sources of heterogeneity: host size and proximity to the stream channel. These sources of heterogeneity influenced both the epidemic and endemic dynamics of this pathogen invasion. This analysis provides empirical support for the influence of heterogeneity on the invasion dynamics of a commercially important forest pathogen and highlights the need to incorporate such natural variability into both invasion theory and methods aimed at controlling future spread.

  4. Antibiotic Administration and Factors Influencing the Vaginal Microbiota during Pregnancy

    DEFF Research Database (Denmark)

    Stokholm, Jakob

    2012-01-01

    The commensal flora consists of non-pathogenic microbiota found on all body surfaces maintaining a well-balanced host-microbial symbiotic state. The vaginal microbiota represents a microbial ecosystem. A low pH level is maintained by acid producing bacteria, most often dominated by Lactobacillus....... The low pH level is together with the host immunity responsible for protection of the vagina. A vast number of other bacterial species are represented in the vaginal commensal microbiota and among these both Staphylococcus and E. coli are often found. Skewing of the vaginal commensal flora...... with a following increase in pH level can lead to an overgrowth of certain microbiota resulting in bacterial vaginosis or vaginal candidiasis. Humans are continuously exposed to a large amount of environmental factors providing a possible influence on their microbial ecology. Antibiotic administration is one...

  5. What Factors Influence Wind Perceptions

    Science.gov (United States)

    Stein, Tatiana

    Over the last decade, wind power has emerged as a possible source of energy and has attracted the attention of homeowners and policy makers worldwide. Many technological hurdles have been overcome in the last few years that make this technology feasible and economical. The United States has added more wind power than any other type of electric generation in 2012. Depending on the location, wind resources have shown to have the potential to offer 20% of the nation's electricity; a single, large wind turbine has the capacity to produce enough electricity to power 350 homes. Throughout the development of wind turbines, however, energy companies have seen significant public opposition towards the tall white structures. The purpose of this research was to measure peoples' perceptions on wind turbine development throughout their growth, from proposal to existing phase. Three hypotheses were developed based on the participant's political affiliation, proximity and knowledge of wind turbines. To validate these hypotheses, participants were asked an array of questions regarding their perception on economic, environmental, and social impacts of wind turbines with an online service called Amazon Mechanical Turk. The responses were from residents living in the United States and required them to provide their zip code for subsequent analysis. The analysis from the data obtained suggests that participants are favorable towards wind turbine development and would be supportive of using the technology in their community. Political affiliation and proximity to the nearest wind turbine in any phase of development (proposal, construction, existing) were also analyzed to determine if they had an effect on a person's overall perception on wind turbines and their technology. From the analysis, political affiliation was seen to be an indirect factor to understanding favorability towards wind turbines; the more liberal you are, the more supportive you will be towards renewable energy use

  6. Host-derived, pore-forming toxin-like protein and trefoil factor complex protects the host against microbial infection.

    Science.gov (United States)

    Xiang, Yang; Yan, Chao; Guo, Xiaolong; Zhou, Kaifeng; Li, Sheng'an; Gao, Qian; Wang, Xuan; Zhao, Feng; Liu, Jie; Lee, Wen-Hui; Zhang, Yun

    2014-05-06

    Aerolysins are virulence factors belonging to the bacterial β-pore-forming toxin superfamily. Surprisingly, numerous aerolysin-like proteins exist in vertebrates, but their biological functions are unknown. βγ-CAT, a complex of an aerolysin-like protein subunit (two βγ-crystallin domains followed by an aerolysin pore-forming domain) and two trefoil factor subunits, has been identified in frogs (Bombina maxima) skin secretions. Here, we report the rich expression of this protein, in the frog blood and immune-related tissues, and the induction of its presence in peritoneal lavage by bacterial challenge. This phenomena raises the possibility of its involvement in antimicrobial infection. When βγ-CAT was administrated in a peritoneal infection model, it greatly accelerated bacterial clearance and increased the survival rate of both frogs and mice. Meanwhile, accelerated Interleukin-1β release and enhanced local leukocyte recruitments were determined, which may partially explain the robust and effective antimicrobial responses observed. The release of interleukin-1β was potently triggered by βγ-CAT from the frog peritoneal cells and murine macrophages in vitro. βγ-CAT was rapidly endocytosed and translocated to lysosomes, where it formed high molecular mass SDS-stable oligomers (>170 kDa). Lysosomal destabilization and cathepsin B release were detected, which may explain the activation of caspase-1 inflammasome and subsequent interleukin-1β maturation and release. To our knowledge, these results provide the first functional evidence of the ability of a host-derived aerolysin-like protein to counter microbial infection by eliciting rapid and effective host innate immune responses. The findings will also largely help to elucidate the possible involvement and action mechanisms of aerolysin-like proteins and/or trefoil factors widely existing in vertebrates in the host defense against pathogens.

  7. Patient factors that influence warfarin dose response.

    Science.gov (United States)

    White, Pamela J

    2010-06-01

    Warfarin has long been the mainstay of oral anticoagulation therapy for the treatment and prevention of venous and arterial thrombosis. The narrow therapeutic index of warfarin, and the complex number of factors that influence international normalized ratio (INR) response, makes optimization of warfarin therapy challenging. Determination of the appropriate warfarin dose during initiation and maintenance therapy requires an understanding of patient factors that influence dose response: age, body weight, nutritional status, acute and chronic disease states, and changes in concomitant drug therapy and diet. This review will examine specific clinical factors that can affect the pharmacokinetics and pharmacodynamics of warfarin, as well as the role of pharmacogenetics in optimizing warfarin therapy.

  8. DMPD: The interferon regulatory factor family in host defense: mechanism of action. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17502370 The interferon regulatory factor family in host defense: mechanism of acti....html) (.csml) Show The interferon regulatory factor family in host defense: mechanism of action. PubmedID 1...7502370 Title The interferon regulatory factor family in host defense: mechanism

  9. Interaction between viral RNA silencing suppressors and host factors in plant immunity.

    Science.gov (United States)

    Nakahara, Kenji S; Masuta, Chikara

    2014-08-01

    To elucidate events in the molecular arms race between the host and pathogen in evaluating plant immunity, a zigzag model is useful for uncovering aspects common to different host-pathogen interactions. By analogy of the steps in virus-host interactions with the steps in the standard zigzag model outlined in recent papers, we may regard RNA silencing as pattern-triggered immunity (PTI) against viruses, RNA silencing suppressors (RSSs) as effectors to overcome host RNA silencing and resistance gene (R-gene)-mediated defense as effector-triggered immunity (ETI) recognizing RSSs as avirulence proteins. However, because the standard zigzag model does not fully apply to some unique aspects in the interactions between a plant host and virus, we here defined a model especially designed for viruses. Although we simplified the phenomena involved in the virus-host interactions in the model, certain specific interactive steps can be explained by integrating additional host factors into the model. These host factors are thought to play an important role in maintaining the efficacy of the various steps in the main pathway of defense against viruses in this model for virus-plant interactions. For example, we propose candidates that may interact with viral RSSs to induce the resistance response. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Genetic structure in the seabuckthorn carpenter moth (Holcocerus hippophaecolus in China: the role of outbreak events, geographical and host factors.

    Directory of Open Access Journals (Sweden)

    Jing Tao

    Full Text Available Understanding factors responsible for structuring genetic diversity is of fundamental importance in evolutionary biology. The seabuckthorn carpenter moth (Holcocerus hippophaecolus Hua is a native species throughout the north of China and is considered the main threat to seabuckthorn, Hippophae rhamnoides L. We assessed the influence of outbreaks, environmental factors and host species in shaping the genetic variation and structure of H. hippophaecolus by using Amplified Fragment Length Polymorphism (AFLP markers. We rejected the hypothesis that outbreak-associated genetic divergence exist, as evidenced by genetic clusters containing a combination of populations from historical outbreak areas, as well as non-outbreak areas. Although a small number of markers (4 of 933 loci were identified as candidates under selection in response to population densities. H. hippophaecolus also did not follow an isolation-by-distance pattern. We rejected the hypothesis that outbreak and drought events were driving the genetic structure of H. hippophaecolus. Rather, the genetic structure appears to be influenced by various confounding bio-geographical factors. There were detectable genetic differences between H. hippophaecolus occupying different host trees from within the same geographic location. Host-associated genetic divergence should be confirmed by further investigation.

  11. Factors influencing lysis time stochasticity in bacteriophage λ

    Directory of Open Access Journals (Sweden)

    Dennehy John J

    2011-08-01

    Full Text Available Abstract Background Despite identical genotypes and seemingly uniform environments, stochastic gene expression and other dynamic intracellular processes can produce considerable phenotypic diversity within clonal microbes. One trait that provides a good model to explore the molecular basis of stochastic variation is the timing of host lysis by bacteriophage (phage. Results Individual lysis events of thermally-inducible λ lysogens were observed using a temperature-controlled perfusion chamber mounted on an inverted microscope. Both mean lysis time (MLT and its associated standard deviation (SD were estimated. Using the SD as a measure of lysis time stochasticity, we showed that lysogenic cells in controlled environments varied widely in lysis times, and that the level of lysis time stochasticity depended on allelic variation in the holin sequence, late promoter (pR' activity, and host growth rate. In general, the MLT was positively correlated with the SD. Both lower pR' activities and lower host growth rates resulted in larger SDs. Results from premature lysis, induced by adding KCN at different time points after lysogen induction, showed a negative correlation between the timing of KCN addition and lysis time stochasticity. Conclusions Taken together with results published by others, we conclude that a large fraction of λ lysis time stochasticity is the result of random events following the expression and diffusion of the holin protein. Consequently, factors influencing the timing of reaching critical holin concentrations in the cell membrane, such as holin production rate, strongly influence the mean lysis time and the lysis time stochasticity.

  12. Role of viral and host factors in interferon based therapy of hepatitis C virus infection

    Science.gov (United States)

    2013-01-01

    The current standard of care (SOC) for hepatitis C virus (HCV) infection is the combination of pegylated interferon (PEG-IFN), Ribavirin and protease inhibitor for HCV genotype 1. Nevertheless, this treatment is successful only in 70-80% of the patients. In addition, the treatment is not economical and is of immense physical burden for the subject. It has been established now, that virus-host interactions play a significant role in determining treatment outcomes. Therefore identifying biological markers that may predict the treatment response and hence treatment outcome would be useful. Both IFN and Ribavirin mainly act by modulating the immune system of the patient. Therefore, the treatment response is influenced by genetic variations of the human as well as the HCV genome. The goal of this review article is to summarize the impact of recent scientific advances in this area regarding the understanding of human and HCV genetic variations and their effect on treatment outcomes. Google scholar and PubMed have been used for literature research. Among the host factors, the most prominent associations are polymorphisms within the region of the interleukin 28B (IL28B) gene, but variations in other cytokine genes have also been linked with the treatment outcome. Among the viral factors, HCV genotypes are noteworthy. Moreover, for sustained virological responses (SVR), variations in core, p7, non-structural 2 (NS2), NS3 and NS5A genes are also important. However, all considered single nucleotide polymorphisms (SNPs) of IL28B and viral genotypes are the most important predictors for interferon based therapy of HCV infection. PMID:24079723

  13. The Influence of Programmed Cell Death in Myeloid Cells on Host Resilience to Infection with Legionella pneumophila or Streptococcus pyogenes

    Science.gov (United States)

    Gamradt, Pia; Xu, Yun; Gratz, Nina; Duncan, Kellyanne; Kobzik, Lester; Högler, Sandra; Decker, Thomas

    2016-01-01

    Pathogen clearance and host resilience/tolerance to infection are both important factors in surviving an infection. Cells of the myeloid lineage play important roles in both of these processes. Neutrophils, monocytes, macrophages, and dendritic cells all have important roles in initiation of the immune response and clearance of bacterial pathogens. If these cells are not properly regulated they can result in excessive inflammation and immunopathology leading to decreased host resilience. Programmed cell death (PCD) is one possible mechanism that myeloid cells may use to prevent excessive inflammation. Myeloid cell subsets play roles in tissue repair, immune response resolution, and maintenance of homeostasis, so excessive PCD may also influence host resilience in this way. In addition, myeloid cell death is one mechanism used to control pathogen replication and dissemination. Many of these functions for PCD have been well defined in vitro, but the role in vivo is less well understood. We created a mouse that constitutively expresses the pro-survival B-cell lymphoma (bcl)-2 protein in myeloid cells (CD68(bcl2tg), thus decreasing PCD specifically in myeloid cells. Using this mouse model we explored the impact that decreased cell death of these cells has on infection with two different bacterial pathogens, Legionella pneumophila and Streptococcus pyogenes. Both of these pathogens target multiple cell death pathways in myeloid cells, and the expression of bcl2 resulted in decreased PCD after infection. We examined both pathogen clearance and host resilience and found that myeloid cell death was crucial for host resilience. Surprisingly, the decreased myeloid PCD had minimal impact on pathogen clearance. These data indicate that the most important role of PCD during infection with these bacteria is to minimize inflammation and increase host resilience, not to aid in the clearance or prevent the spread of the pathogen. PMID:27973535

  14. The influence of aphids (Myzus persicae) and pink lady beetle larvae (Coleomegilla maculata) on host plant preference of imported cabbageworm (Pieris rapae)

    Science.gov (United States)

    Oviposition decisions by herbivorous insects hinge on multiple factors; host plant quality, enemy free space, plant density, offspring performance, and competition for resources all which influence decisions by an ovipositing female. Here, we evaluate whether the presence of aphids (a competitor) or...

  15. To be or not to be: The host genetic factor and beyond in Helicobacter pylori mediated gastro-duodenal diseases.

    Science.gov (United States)

    Datta De, Dipanjana; Roychoudhury, Susanta

    2015-03-14

    Helicobacter pylori (H. pylori) have long been associated with a spectrum of disease outcomes in the gastro-duodenal system. Heterogeneity in bacterial virulence factors or strains is not enough to explain the divergent disease phenotypes manifested by the infection. This review focuses on host genetic factors that are involved during infection and eventually are thought to influence the disease phenotype. We have summarized the different host genes that have been investigated for association studies in H. pylori mediated duodenal ulcer or gastric cancer. We discuss that as the bacteria co-evolved with the host; these host gene also show much variation across different ethnic population. We illustrate the allelic distribution of interleukin-1B, across different population which is one of the most popular candidate gene studied with respect to H. pylori infections. Further, we highlight that several polymorphisms in the pathway gene can by itself or collectively affect the acid secretion pathway axis (gastrin: somatostatin) thereby resulting in a spectrum of disease phenotype.

  16. Influencing factors in MMR immunisation decision making.

    Science.gov (United States)

    Hill, Marie C; Cox, Carol L

    Immunisation decision making is not a straightforward process for parents. Many factors influence parental decision making on whether they immunise their child with the measles, mumps and rubella (MMR) vaccine. The feasibility study described in this article provides insight into influencing factors associated with decisions regarding the immunisation of children by parents. The study findings suggest that the practice nurse is a credible source of information for parents seeking informed decision making. At a time when the incidence of measles and mumps is rising in the UK, the provision of appropriate information by the practice nurse has the potential to increase uptake of the MMR vaccine.

  17. Circles of Influence and Chains of Command: The Social Processes Whereby Ethnic Communities Influence Host Societies

    Science.gov (United States)

    Orum, Anthony M.

    2005-01-01

    Research into immigration has for many years focused most of its attention on the issue of how immigrants adapt to host societies. This tendency is especially true in the work of sociologists. Yet if we acknowledge the growing ethnic diversity today in the United States and elsewhere, the most interesting questions arise as to how immigrants…

  18. Host genetic risk factors for West Nile virus infection and disease progression.

    Directory of Open Access Journals (Sweden)

    Abigail W Bigham

    Full Text Available West Nile virus (WNV, a category B pathogen endemic in parts of Africa, Asia and Europe, emerged in North America in 1999, and spread rapidly across the continental U.S. Outcomes of infection with WNV range from asymptomatic to severe neuroinvasive disease manifested as encephalitis, paralysis, and/or death. Neuroinvasive WNV disease occurs in less than one percent of cases, and although host genetic factors are thought to influence risk for symptomatic disease, the identity of these factors remains largely unknown. We tested 360 common haplotype tagging and/or functional SNPs in 86 genes that encode key regulators of immune function in 753 individuals infected with WNV including: 422 symptomatic WNV cases and 331 cases with asymptomatic infections. After applying a Bonferroni correction for multiple tests and controlling for population stratification, SNPs in IRF3 (OR 0.54, p = 0.035 and MX1, (OR 0.19, p = 0.014 were associated with symptomatic WNV infection and a single SNP in OAS1 (OR 9.79, p = 0.003 was associated with increased risk for West Nile encephalitis and paralysis (WNE/P. Together, these results suggest that genetic variation in the interferon response pathway is associated with both risk for symptomatic WNV infection and WNV disease progression.

  19. Endogenous tissue factor pathway inhibitor has a limited effect on host defence in murine pneumococcal pneumonia.

    Science.gov (United States)

    van den Boogaard, Florry E; van 't Veer, Cornelis; Roelofs, Joris J T H; Meijers, Joost C M; Schultz, Marcus J; Broze, George J; van der Poll, Tom

    2015-07-01

    Streptococcus (S.) pneumoniae is the most common causative pathogen in community-acquired pneumonia. Coagulation and inflammation interact in the host response to infection. Tissue factor pathway inhibitor (TFPI) is a natural anticoagulant protein that inhibits tissue factor (TF), the main activator of inflammation-induced coagulation. It was the objective of this study to investigate the effect of endogenous TFPI levels on coagulation, inflammation and bacterial growth during S. pneumoniae pneumonia in mice. The effect of low endogenous TFPI levels was studied by administration of a neutralising anti-TFPI antibody to wild-type mice, and by using genetically modified mice expressing low levels of TFPI, due to a genetic deletion of the first Kunitz domain of TFPI (TFPIK1(-/-)) rescued with a human TFPI transgene. Pneumonia was induced by intranasal inoculation with S. pneumoniae and samples were obtained at 6, 24 and 48 hours after infection. Anti-TFPI reduced TFPI activity by ~50 %. Homozygous lowTFPI mice and heterozygous controls had ~10 % and ~50 % of normal TFPI activity, respectively. TFPI levels did not influence bacterial growth or dissemination. Whereas lung pathology was unaffected in all groups, mice with ~10 % (but not with ~50 %) of TFPI levels displayed elevated lung cytokine and chemokine concentrations 24 hours after infection. None of the groups with low TFPI levels showed an altered procoagulant response in lungs or plasma during pneumonia. These data argue against an important role for endogenous TFPI in the antibacterial, inflammatory and procoagulant response during pneumococcal pneumonia.

  20. Influence of Azospirillum spp. on the nitrogen supply of a gramineous host

    NARCIS (Netherlands)

    Christiansen - Weniger, C.

    1991-01-01

    The main objectives of this study were to identify factors that control the behaviour of Azospirillum in the rhizosphere of a gramineous plant in order to be able to optimize the association between the bacteria and the host plants in terms of nitrogen supply to the hos

  1. INFLUENCE FACTORS FOR LEASING MARKET CONTRACTS

    Directory of Open Access Journals (Sweden)

    Oana BĂRBULESCU

    2016-11-01

    Full Text Available This paper aims to investigate the relationship between leasing contracts and some factors that influence the value of these contracts. In order to do this, we have decided on some quantitative marketing research by appealing to statistics for accomplishing the objectives that we have set: to find a correlation between the turnover percentage assigned to leasing expenses and several influence factors. This study indicated that the more contracts are signed by a firm, the more likely is to assign a bigger fraction of the income to each new leasing contract. The study confirmed that bigger companies are relying more on leasing as a way of financing than small companies. This study also discovered that companies with more employees are using larger contracts in order to sustain their activity. The findings are expected to contribute to adjusting the offers by the leasing companies, taking into consideration these factors and to using these factors in order to better predict the market evolution.

  2. Functional analysis of host factors that mediate the intracellular lifestyle of Cryptococcus neoformans.

    Directory of Open Access Journals (Sweden)

    Qing-Ming Qin

    2011-06-01

    Full Text Available Cryptococcus neoformans (Cn, the major causative agent of human fungal meningoencephalitis, replicates within phagolysosomes of infected host cells. Despite more than a half-century of investigation into host-Cn interactions, host factors that mediate infection by this fungal pathogen remain obscure. Here, we describe the development of a system that employs Drosophila S2 cells and RNA interference (RNAi to define and characterize Cn host factors. The system recapitulated salient aspects of fungal interactions with mammalian cells, including phagocytosis, intracellular trafficking, replication, cell-to-cell spread and escape of the pathogen from host cells. Fifty-seven evolutionarily conserved host factors were identified using this system, including 29 factors that had not been previously implicated in mediating fungal pathogenesis. Subsequent analysis indicated that Cn exploits host actin cytoskeletal elements, cell surface signaling molecules, and vesicle-mediated transport proteins to establish a replicative niche. Several host molecules known to be associated with autophagy (Atg, including Atg2, Atg5, Atg9 and Pi3K59F (a class III PI3-kinase were also uncovered in our screen. Small interfering RNA (siRNA mediated depletion of these autophagy proteins in murine RAW264.7 macrophages demonstrated their requirement during Cn infection, thereby validating findings obtained using the Drosophila S2 cell system. Immunofluorescence confocal microscopy analyses demonstrated that Atg5, LC3, Atg9a were recruited to the vicinity of Cn containing vacuoles (CnCvs in the early stages of Cn infection. Pharmacological inhibition of autophagy and/or PI3-kinase activity further demonstrated a requirement for autophagy associated host proteins in supporting infection of mammalian cells by Cn. Finally, systematic trafficking studies indicated that CnCVs associated with Atg proteins, including Atg5, Atg9a and LC3, during trafficking to a terminal intracellular

  3. Obesity and endocrine therapy: host factors and breast cancer outcome.

    Science.gov (United States)

    Goodwin, Pamela J

    2013-08-01

    Obesity is becoming increasingly prevalent and it has been linked to poor breast cancer outcomes. Because obesity is associated with increased adipose tissue mass and aromatase activity [the target of aromatase inhibitors (AIs)], there is concern that these agents may be less effective in women who are overweight or obese. Four of the randomized trials of AIs vs. tamoxifen conducted in the adjuvant breast cancer setting (ATAC, BIG 1-98 and TEAM in the postmenopausal setting and ABCSG-12 in the premenopausal setting) have reported effects of body mass index (BMI) on the relative effectiveness of an AI vs. tamoxifen. Obesity was confirmed as an adverse prognostic factor in ATAC and BIG 1-98 but not the TEAM study; in ABSCG-12, obesity was associated with poor outcomes in the anastrozole arm only. In the three postmenopausal trials, the use of an AI vs. tamoxifen was associated with better outcomes at all levels of BMI [all hazard ratios for recurrence breast cancer. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. A factor analysis to detect factors influencing building national brand

    Directory of Open Access Journals (Sweden)

    Naser Azad

    Full Text Available Developing a national brand is one of the most important issues for development of a brand. In this study, we present factor analysis to detect the most important factors in building a national brand. The proposed study uses factor analysis to extract the most influencing factors and the sample size has been chosen from two major auto makers in Iran called Iran Khodro and Saipa. The questionnaire was designed in Likert scale and distributed among 235 experts. Cronbach alpha is calculated as 84%, which is well above the minimum desirable limit of 0.70. The implementation of factor analysis provides six factors including “cultural image of customers”, “exciting characteristics”, “competitive pricing strategies”, “perception image” and “previous perceptions”.

  5. Microbial Hub Taxa Link Host and Abiotic Factors to Plant Microbiome Variation.

    Directory of Open Access Journals (Sweden)

    Matthew T Agler

    2016-01-01

    Full Text Available Plant-associated microorganisms have been shown to critically affect host physiology and performance, suggesting that evolution and ecology of plants and animals can only be understood in a holobiont (host and its associated organisms context. Host-associated microbial community structures are affected by abiotic and host factors, and increased attention is given to the role of the microbiome in interactions such as pathogen inhibition. However, little is known about how these factors act on the microbial community, and especially what role microbe-microbe interaction dynamics play. We have begun to address this knowledge gap for phyllosphere microbiomes of plants by simultaneously studying three major groups of Arabidopsis thaliana symbionts (bacteria, fungi and oomycetes using a systems biology approach. We evaluated multiple potential factors of microbial community control: we sampled various wild A. thaliana populations at different times, performed field plantings with different host genotypes, and implemented successive host colonization experiments under lab conditions where abiotic factors, host genotype, and pathogen colonization was manipulated. Our results indicate that both abiotic factors and host genotype interact to affect plant colonization by all three groups of microbes. Considering microbe-microbe interactions, however, uncovered a network of interkingdom interactions with significant contributions to community structure. As in other scale-free networks, a small number of taxa, which we call microbial "hubs," are strongly interconnected and have a severe effect on communities. By documenting these microbe-microbe interactions, we uncover an important mechanism explaining how abiotic factors and host genotypic signatures control microbial communities. In short, they act directly on "hub" microbes, which, via microbe-microbe interactions, transmit the effects to the microbial community. We analyzed two "hub" microbes (the

  6. On factors influencing students’ listening abilities

    Institute of Scientific and Technical Information of China (English)

    胡天秀

    2012-01-01

    As we all know,listening,speaking,reading,and writing are four basic skills in language teaching and learning.Listening plays an important role in improving other skills.There are some factors influencing students’ listening abilities.So it’s important for teachers to improve students’ listening abilities.

  7. Factors Influencing High School Students' Career Aspirations

    Science.gov (United States)

    Tang, Mei; Pan, Wei; Newmeyer, Mark D.

    2008-01-01

    This article explores the factors influencing high school students' career aspirations with a study analyzing 141 high school students. The Social Cognitive Career Development Model was utilized to examine the interactive relationships among learning experiences, career self-efficacy, outcome expectations, career interests, and career choices. The…

  8. Factors influencing laser cutting of wood

    Science.gov (United States)

    V.G. Barnekov; C.W. McMillin; H.A. Huber

    1986-01-01

    Factors influencing the ability of lasers to cut wood may be generally classified into these three areas: 1) characteristics of the laser beam; 2) equipment and processing variables; and 3) properties of the workpiece. Effects of beam power, mode, polarization, and stability are discussed as are aspects of optics, location of focal point, feed speed, gas-jet assist...

  9. Factors influencing the process of farm liquidation

    Directory of Open Access Journals (Sweden)

    Michał Dudek

    2010-01-01

    Full Text Available In the paper the logit analysis was used in order to define the factors influencing farm liquidation. The prevalence of this phenomenon and its regional differences were analysed. Significant and negative impact of the number of people in a family farm and the number of machinery and technical equipment, as well as the positive impact of the farmer’ age are reported.

  10. Social Factors Influencing Child Health in Ghana.

    Directory of Open Access Journals (Sweden)

    Emmanuel Quansah

    Full Text Available Social factors have profound effects on health. Children are especially vulnerable to social influences, particularly in their early years. Adverse social exposures in childhood can lead to chronic disorders later in life. Here, we sought to identify and evaluate the impact of social factors on child health in Ghana. As Ghana is unlikely to achieve the Millennium Development Goals' target of reducing child mortality by two-thirds between 1990 and 2015, we deemed it necessary to identify social determinants that might have contributed to the non-realisation of this goal.ScienceDirect, PubMed, MEDLINE via EBSCO and Google Scholar were searched for published articles reporting on the influence of social factors on child health in Ghana. After screening the 98 articles identified, 34 of them that met our inclusion criteria were selected for qualitative review.Major social factors influencing child health in the country include maternal education, rural-urban disparities (place of residence, family income (wealth/poverty and high dependency (multiparousity. These factors are associated with child mortality, nutritional status of children, completion of immunisation programmes, health-seeking behaviour and hygiene practices.Several social factors influence child health outcomes in Ghana. Developing more effective responses to these social determinants would require sustainable efforts from all stakeholders including the Government, healthcare providers and families. We recommend the development of interventions that would support families through direct social support initiatives aimed at alleviating poverty and inequality, and indirect approaches targeted at eliminating the dependence of poor health outcomes on social factors. Importantly, the expansion of quality free education interventions to improve would-be-mother's health knowledge is emphasised.

  11. Seasonal and Spatial Environmental Influence on Opisthorchis viverrini Intermediate Hosts, Abundance, and Distribution: Insights on Transmission Dynamics and Sustainable Control

    Science.gov (United States)

    Kim, Christina Sunyoung; Echaubard, Pierre; Suwannatrai, Apiporn; Kaewkes, Sasithorn; Wilcox, Bruce A.; Sripa, Banchob

    2016-01-01

    Background Opisthorchis viverrini (Ov) is a complex-life-cycle trematode affecting 10 million people in SEA (Southeast Asia). Human infection occurs when infected cyprinid fish are consumed raw or undercooked. Ov requires three hosts and presents two free-living parasitic stages. As a consequence Ov transmission and infection in intermediate and human hosts are strongly mediated by environmental factors and understanding how environmental variability influences intermediate host abundance is critical. The objectives of this study were 1) to document water parameters, intermediate hosts abundance and infection spatio-temporal variation, 2) to assess their causal relationships and identify windows of transmission risk. Methodology/Principal Findings Fish and snails were collected monthly for one year at 12 sites in Lawa Lake, an Ov-endemic region of Khon Kaen Province in Northeast Thailand. Physicochemical water parameters [pH, temperature (Tp), dissolved oxygen (DO), Salinity, electrical conductivity (EC), total dissolved solid (TDS), nitrite nitrogen (NO2-N), lead (Pb), total coliform bacteria (TCB) and fecal coliform bacteria (FCB)] were measured. Multivariate analyses, linear models and kriging were used to characterize water parameter variation and its influence on host abundance and infection prevalence. We found that sampling sites could be grouped in three clusters and discriminated along a nitrogen-salinity gradient where higher levels in the lake’s southern region predicted higher Bithynia relative abundance (P<0.05) and lower snail and fish species diversity (P<0.05). Highest Bithynia abundance occurred during rainy season (P<0.001), independently of site influence. Cyprinids were the most abundant fish family and higher cyprinid relative abundance was found in areas with higher Bithynia relative abundance (P<0.05). Ov infection in snails was anecdotal while Ov infection in fish was higher in the southern region (P<0.001) at sites showing high FCB

  12. Seasonal and Spatial Environmental Influence on Opisthorchis viverrini Intermediate Hosts, Abundance, and Distribution: Insights on Transmission Dynamics and Sustainable Control.

    Directory of Open Access Journals (Sweden)

    Christina Sunyoung Kim

    2016-11-01

    Full Text Available Opisthorchis viverrini (Ov is a complex-life-cycle trematode affecting 10 million people in SEA (Southeast Asia. Human infection occurs when infected cyprinid fish are consumed raw or undercooked. Ov requires three hosts and presents two free-living parasitic stages. As a consequence Ov transmission and infection in intermediate and human hosts are strongly mediated by environmental factors and understanding how environmental variability influences intermediate host abundance is critical. The objectives of this study were 1 to document water parameters, intermediate hosts abundance and infection spatio-temporal variation, 2 to assess their causal relationships and identify windows of transmission risk.Fish and snails were collected monthly for one year at 12 sites in Lawa Lake, an Ov-endemic region of Khon Kaen Province in Northeast Thailand. Physicochemical water parameters [pH, temperature (Tp, dissolved oxygen (DO, Salinity, electrical conductivity (EC, total dissolved solid (TDS, nitrite nitrogen (NO2-N, lead (Pb, total coliform bacteria (TCB and fecal coliform bacteria (FCB] were measured. Multivariate analyses, linear models and kriging were used to characterize water parameter variation and its influence on host abundance and infection prevalence. We found that sampling sites could be grouped in three clusters and discriminated along a nitrogen-salinity gradient where higher levels in the lake's southern region predicted higher Bithynia relative abundance (P<0.05 and lower snail and fish species diversity (P<0.05. Highest Bithynia abundance occurred during rainy season (P<0.001, independently of site influence. Cyprinids were the most abundant fish family and higher cyprinid relative abundance was found in areas with higher Bithynia relative abundance (P<0.05. Ov infection in snails was anecdotal while Ov infection in fish was higher in the southern region (P<0.001 at sites showing high FCB.Our results indicate that water contamination

  13. Problem solving III: factors influencing classroom problem

    Directory of Open Access Journals (Sweden)

    Sayonara Salvador Cabral da Costa

    1997-05-01

    Full Text Available This paper presents a review of the literature in the area of problem solving, particularly in physics, focusing only on factors that influence classroom problem solving. Fifty-seven papers have been analyzed in terms of theoretical basis, investigated factors/methodology and findings/relevant factors, which were organized in a table that served as support for a synthesis made by the authors. It is the third of a four-paper series reviewing different aspects of the problem solving subject.

  14. Factors that influence women's dispositions toward science

    Science.gov (United States)

    Atria, Catherine Graczyk

    Females have been underrepresented in the study of science and science careers for decades although advancements have been made in closing this gender gap, the gap persists particularly in the physical sciences. Variables which influence a woman's desire to pursue and maintain a science course of study and career must be discovered. The United States lags behind other industrialized countries in the fields of science, math, and engineering. Females comprise an estimated half of the population; their potential contributions cannot be ignored or overlooked. This retrospective research study explores the personal experiences of ten women enrolled in science majors, with science related career plans. The goal of this study is to describe the factors that influence the participants' interest in science. The findings, the effect of science coursework, science teachers' personality and manner, other influential educational personnel, role models and mentors, external influences exclusive of school, parental influence, locus of control and positive attitudes toward science confirm what other researchers have found.

  15. Uncovering Factors Influencing Interpersonal Health Communication.

    Science.gov (United States)

    Donné, Lennie; Jansen, Carel; Hoeks, John

    2017-01-01

    Talking to friends, family, or peers about health issues might, among other things, increase knowledge of social norms and feelings of self-efficacy in adopting a healthier lifestyle. We often see interpersonal health communication as an important mediating factor in the effects of health campaigns on health behavior. No research has been done so far, however, on factors that influence whether and how people talk about health issues without being exposed to a health campaign first. In this exploratory study, we interviewed 12 participants about their communication behavior concerning six different health themes, like smoking and exercising. The results suggest that at least four types of interpersonal health communication can be distinguished, each influenced by different factors, like conversational partner and objective of the conversation. Future research should take this diversity of interpersonal health communication into account, and focus on designing health campaigns that aim to trigger dialogue within target populations.

  16. Theoretical difference between impact factor and influence factor

    Directory of Open Access Journals (Sweden)

    Đilda Pečarić

    2010-06-01

    Full Text Available Bibliometric constructions of "knowledge maps" and "cognitive structures of science" do not differentiate between impact and influence factors. The difference can be constructedaccording to different meaning and interpretation of the terms reference and citation. Reference is "acknowledgment which one author gives to another", whereas citation is "acknowledgment which one document receives from another". Development of Information Science according to period and subject area is analyzed on the corpus of citation literature retrieved from doctoral dissertations in Information Science from 1978 to 2007 at Croatian universities. The research aim is to indicate the difference between document impact factor and author's influence factor (i.e. reference ability to produce effects on actions, behavior, and opinions of authors of doctoral theses. The influence factor serves to distinguish the key role of cited authors in time and according to the duration of the influence (the average age for cited papers of dominant authors in different periods is between eight and ten years. The difference between linear and interactive communication seems vital for the interpretation of cited half-life, i.e. the attitude of one science community towards used information resources and cognitive heritage. The analyzed corpus of 22,210 citations can be divided into three communication phases according to influence factor criteria: in the phase of dialogue and interactive communication 25% of bibliographic units are cited in the first four years; in the second phase another 25% of units are cited from the fifth to the ninth year; after ten years, in the dominant linear communication phase, approximately 30% of units are cited.

  17. What Factors Influence Knowledge Sharing in Organizations?

    DEFF Research Database (Denmark)

    Razmerita, Liana; Kirchner, Kathrin; Nielsen, Pia

    2016-01-01

    Purpose: Enterprise social media platforms provide new ways of sharing knowledge and communicating within organizations to benefit from the social capital and valuable knowledge that employees have. Drawing on social dilemma and self-determination theory, the aim of the study is to understand what...... factors drive employees’ participation and what factors hamper their participation in enterprise social media. Design/methodology/approach: Based on a literature review, a unified research model is derived integrating demographic, individual, organizational and technological factors that influence...... knowledge sharing framework helps to understand what factors impact engagement on social media. Furthermore the article suggests different types of interventions to overcome the social dilemma of knowledge sharing. Originality/value: The study contributes to an understanding of factors leading...

  18. Investigating important factors influencing purchasing from chains

    Directory of Open Access Journals (Sweden)

    Naser Azad

    2012-04-01

    Full Text Available In this paper, we survey important factors, influencing customers to buy more from one of well known food market operating in capital city of Iran named Shahrvand. The survey studies the effects of six factors including customer's perception, persuasive factors, brand, customers' expectations, product's characteristics and special features of store on attracting more customers. We have distributed questionnaire among 196 customers who regularly visit stores and analyzed details of the data. The results indicate that customers' perception is the most important item, which includes eight components. Years of experience is the most important item in our survey followed by impact of color and working hours. Diversity of services is another factor, which plays the most important role followed by quality of services. Next, fidelity and brand are other most important factors and the name of store and risk are in lower degree of importance.

  19. Influence of host age and host deprivation on longevity,egg load dynamics and oviposition rate in Microplitis rufiventris

    Institute of Scientific and Technical Information of China (English)

    ESMAT MOHAMED HEGAZI; GEHAN MOHAMED ABD EL-AZIZ; AHMED YOUSEF EL-SHAZLY; WEDAD EMAM KHAFAGI

    2007-01-01

    Adult size, longevity, egg load dynamics and oviposition of Microplitis rufiventris Kok. which began their development in the first, second, third (preferred hosts) or fourth (non-preferred hosts) instar larvae of Spodoptera littoralis (Boisd.) were studied. The parasitoid size was largely determined by the initial host size at parasitism. Non-ovipositing females derived from older hosts lived for longer periods than those derived from younger ones. However, the ovipositing females, irrespective of their size, lived for almost the same periods. At emergence, the oviducts of adult females contain a significant amount of mature eggs available for oviposition for a few hours on eclosion day. Egg load increases during the early phase of adult life. The amount of additional mature eggs and rate of egg maturation per hour was greater for wasps derived from preferred hosts compared with those in females derived from non-preferred hosts. The pattern of egg production in M. rufiventris females depended on the availability of hosts for parasitization. Host-deprived females depleted the egg complement with aging; the longer the host deprivation, the lower the oviduct egg load.Marked reduction in both realized or potential fecundity of host-deprived females was observed following host availability. Host privation for more than 3 days induced a marked deficit fecundity pattern through the female's life. The realized fecundity was determined by the interaction among host availability, the number of eggs that are matured over the female's life span, oviposition rate and host size from which the female was derived. These results suggest that: (i) M. rufiventris wasp is a weak synovigenic species; (ii) the maturation of additional eggs is inhibited once the maximum oviduct egg load is reached; (iii) the egg load of the newly emerged female is significantly less than the realized fecundity; and (iv)because M. rufiventris females oviposit fewer eggs when they begin depleting their

  20. Cycle Inhibiting Factors (Cifs): Cyclomodulins That Usurp the Ubiquitin-Dependent Degradation Pathway of Host Cells

    Science.gov (United States)

    Taieb, Frédéric; Nougayrède, Jean-Philippe; Oswald, Eric

    2011-01-01

    Cycle inhibiting factors (Cifs) are type III secreted effectors produced by diverse pathogenic bacteria. Cifs are “cyclomodulins” that inhibit the eukaryotic host cell cycle and also hijack other key cellular processes such as those controlling the actin network and apoptosis. This review summarizes current knowledge on Cif since its first characterization in enteropathogenic Escherichia coli, the identification of several xenologues in distant pathogenic bacteria, to its structure elucidation and the recent deciphering of its mode of action. Cif impairs the host ubiquitin proteasome system through deamidation of ubiquitin or the ubiquitin-like protein NEDD8 that regulates Cullin-Ring-ubiquitin Ligase (CRL) complexes. The hijacking of the ubiquitin-dependent degradation pathway of host cells results in the modulation of various cellular functions such as epithelium renewal, apoptosis and immune response. Cif is therefore a powerful weapon in the continuous arm race that characterizes host-bacteria interactions. PMID:22069713

  1. Cycle inhibiting factors (cifs): cyclomodulins that usurp the ubiquitin-dependent degradation pathway of host cells.

    Science.gov (United States)

    Taieb, Frédéric; Nougayrède, Jean-Philippe; Oswald, Eric

    2011-04-01

    Cycle inhibiting factors (Cifs) are type III secreted effectors produced by diverse pathogenic bacteria. Cifs are "cyclomodulins" that inhibit the eukaryotic host cell cycle and also hijack other key cellular processes such as those controlling the actin network and apoptosis. This review summarizes current knowledge on Cif since its first characterization in enteropathogenic Escherichia coli, the identification of several xenologues in distant pathogenic bacteria, to its structure elucidation and the recent deciphering of its mode of action. Cif impairs the host ubiquitin proteasome system through deamidation of ubiquitin or the ubiquitin-like protein NEDD8 that regulates Cullin-Ring-ubiquitin Ligase (CRL) complexes. The hijacking of the ubiquitin-dependent degradation pathway of host cells results in the modulation of various cellular functions such as epithelium renewal, apoptosis and immune response. Cif is therefore a powerful weapon in the continuous arm race that characterizes host-bacteria interactions.

  2. Cycle Inhibiting Factors (Cifs: Cyclomodulins That Usurp the Ubiquitin-Dependent Degradation Pathway of Host Cells

    Directory of Open Access Journals (Sweden)

    Eric Oswald

    2011-03-01

    Full Text Available Cycle inhibiting factors (Cifs are type III secreted effectors produced by diverse pathogenic bacteria. Cifs are “cyclomodulins” that inhibit the eukaryotic host cell cycle and also hijack other key cellular processes such as those controlling the actin network and apoptosis. This review summarizes current knowledge on Cif since its first characterization in enteropathogenic Escherichia coli, the identification of several xenologues in distant pathogenic bacteria, to its structure elucidation and the recent deciphering of its mode of action. Cif impairs the host ubiquitin proteasome system through deamidation of ubiquitin or the ubiquitin-like protein NEDD8 that regulates Cullin-Ring-ubiquitin Ligase (CRL complexes. The hijacking of the ubiquitin-dependent degradation pathway of host cells results in the modulation of various cellular functions such as epithelium renewal, apoptosis and immune response. Cif is therefore a powerful weapon in the continuous arm race that characterizes host-bacteria interactions.

  3. Host genetic factors in susceptibility to HIV-1 infection and progression to AIDS

    Indian Academy of Sciences (India)

    Koushik Chatterjee

    2010-04-01

    HIV-1 infection has rapidly spread worldwide and has become the leading cause of mortality in infectious diseases. The duration for development of AIDS (AIDS progression) is highly variable among HIV–1 infected individuals, ranging from 2–3 years to no signs of AIDS development in the entire lifetime. Several factors regulate the rate at which HIV-1 infection progresses to AIDS. Host genetic factors play an important role in the outcome of such complex or multifactor diseases as AIDS and are also known to regulate the rate of disease progression. This review focuses on the major host genes reported to affect the progression to AIDS in HIV-1 infected individuals.

  4. Host-guest interaction and structural ordering in polymeric nanoassemblies: Influence of molecular design.

    Science.gov (United States)

    Antoniuk, Iurii; Plazzotta, Beatrice; Wintgens, Véronique; Volet, Gisèle; Nielsen, Thorbjørn T; Pedersen, Jan Skov; Amiel, Catherine

    2017-02-24

    Host-guest nanoassemblies made from spontaneous self-association of host and guest polymers in aqueous solutions have been studied. The specific motivation behind this work was to clarify the impact of the molecular design of the polymers on the interactions between them and on the inner structure of the resulting nanoassemblies. The polymers were composed of a dextran backbone, functionalized with either pendant β-cyclodextrin (CD) or adamantyl (Ada). Those groups were connected to the backbone either directly or with hydrophilic polyethylene glycol (PEG) spacers. To study the impact of those spacers we have proposed a synthetic pathway to new guest polymers. The latter relied on the use of thiol-substituted dextrans as a scaffold, which is subsequently transformed into PEG-Ada grafted guest polymers via nucleophile-mediated thiol-click reaction. Surface plasmon resonance (SPR) studies evidenced strong mutual affinities between the host and guest polymers and showed that the stoichiometry was close to the ideal one (CD/Ada = 1/1) when PEG spacers were introduced. The structure of the nanoassemblies was studied by a combination of dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS). The nature of the individual host or guest polymers has a strong impact on the size and internal structure of the resulting nanoassemblies. The presence of PEG spacers in the polymers led to smaller and less compact nanoassemblies, as evidenced by their large correlation length values (4-20nm compared to 2nm without PEG spacers). At the same time, all types of nanoassemblies appear to have radial density distribution with denser cores and pending polymer chains at the periphery. This study, centered on the influence of the molecular design on the host-guest interactions and structural ordering in polymeric nanoassemblies, will help to tailor host-guest nanoassemblies with attractive drug delivery profiles.

  5. Influence of organizational factors on safety

    Energy Technology Data Exchange (ETDEWEB)

    Haber, S.B.; Metlay, D.S.; Crouch, D.A.

    1990-01-01

    There is a need for a better understanding of exactly how organizational management factors at a nuclear power plant (NPP) affect plant safety performance, either directly or indirectly, and how these factors might be observed, measured, and evaluated. The purpose of this research project is to respond to that need by developing a general methodology for characterizing these organizational and management factors, systematically collecting information on their status and integrating that information into various types of evaluative activities. Research to date has included the development of the Nuclear Organization and Management Analysis Concept (NOMAC) of a NPP, the identification of key organizational and management factors, and the identification of the methods for systematically measuring and analyzing the influence of these factors on performance. Most recently, two field studies, one at a fossil fuel plant and the other at a NPP, were conducted using the developed methodology. Results are presented from both studies highlighting the acceptability, practicality, and usefulness of the methods used to assess the influence of various organizational and management factors including culture, communication, decision-making, standardization, and oversight. 6 refs., 3 figs., 1 tab.

  6. Factors Influencing Colorectal Cancer Screening Participation

    Directory of Open Access Journals (Sweden)

    Antonio Z. Gimeno García

    2012-01-01

    Full Text Available Colorectal cancer (CRC is a major health problem worldwide. Although population-based CRC screening is strongly recommended in average-risk population, compliance rates are still far from the desirable rates. High levels of screening uptake are necessary for the success of any screening program. Therefore, the investigation of factors influencing participation is crucial prior to design and launches a population-based organized screening campaign. Several studies have identified screening behaviour factors related to potential participants, providers, or health care system. These influencing factors can also be classified in non-modifiable (i.e., demographic factors, education, health insurance, or income and modifiable factors (i.e., knowledge about CRC and screening, patient and provider attitudes or structural barriers for screening. Modifiable determinants are of great interest as they are plausible targets for interventions. Interventions at different levels (patient, providers or health care system have been tested across the studies with different results. This paper analyzes factors related to CRC screening behaviour and potential interventions designed to improve screening uptake.

  7. Spatial structure and nest demography reveal the influence of competition, parasitism and habitat quality on slavemaking ants and their hosts

    Directory of Open Access Journals (Sweden)

    Fischer-Blass Birgit

    2011-03-01

    Full Text Available Abstract Background Natural communities are structured by intra-guild competition, predation or parasitism and the abiotic environment. We studied the relative importance of these factors in two host-social parasite ecosystems in three ant communities in Europe (Bavaria and North America (New York, West Virginia. We tested how these factors affect colony demography, life-history and the spatial pattern of colonies, using a large sample size of more than 1000 colonies. The strength of competition was measured by the distance to the nearest competitor. Distance to the closest social parasite colony was used as a measure of parasitism risk. Nest sites (i.e., sticks or acorns are limited in these forest ecosystems and we therefore included nest site quality as an abiotic factor in the analysis. In contrast to previous studies based on local densities, we focus here on the positioning and spatial patterns and we use models to compare our predictions to random expectations. Results Colony demography was universally affected by the size of the nest site with larger and more productive colonies residing in larger nest sites of higher quality. Distance to the nearest competitor negatively influenced host demography and brood production in the Bavarian community, pointing to an important role of competition, while social parasitism was less influential in this community. The New York community was characterized by the highest habitat variability, and productive colonies were clustered in sites of higher quality. Colonies were clumped on finer spatial scales, when we considered only the nearest neighbors, but more regularly distributed on coarser scales. The analysis of spatial positioning within plots often produced different results compared to those based on colony densities. For example, while host and slavemaker densities are often positively correlated, slavemakers do not nest closer to potential host colonies than expected by random. Conclusions The

  8. Individual host factors associated with Onchocerca volvulus microfilarial densities 15, 80 and 180 days after a first dose of ivermectin.

    Science.gov (United States)

    Pion, Sébastien D S; Grout, Lise; Kamgno, Joseph; Nana-Djeunga, Hugues; Boussinesq, Michel

    2011-09-01

    Reduction in Onchocerca volvulus skin microfilarial densities after treatment with ivermectin shows wide between-host variation. Data from two separate studies conducted in Cameroon on onchocerciasis patients treated for the first time with ivermectin were analyzed to identify host factors associated with microfilarial density at different time-points after treatment. In one site (Nkam valley), the dataset included 103 adult males for whom age, number of palpable onchocercal nodules and microfilarial densities on D0 (pre-treatment), D15, D80 and D180 were available. In the other site (Vina valley), analyses were conducted on 965 individuals of both sexes aged 5 years and over; in this dataset, available information included age, gender, exact dose of ivermectin received, onchocerciasis endemicity level in the village of residence and microfilarial densities on D0 and D180. Negative binomial regression models of microfilarial density at the different intervals post-treatment were fitted, using maximum likelihood, with the available independent variables. Gender and age were found to be associated with microfilarial density on D180. The initial microfilarial density influenced post-treatment densities at all the time-points. All other things being equal, microfilarial densities on D180 were higher in individuals harbouring a higher number of nodules or living in communities with high endemicity levels. This study demonstrates that O. volvulus microfilarial density measured after a first treatment with ivermectin, and thus probably the rate of skin repopulation by microfilariae (mf) varies according to several host factors. Should such factors also influence ivermectin efficacy after repeated treatment, then they should be taken into account to determine whether sub-optimal responses to treatment reported from various areas in Africa are actually due to parasite-related factors, particularly to the emergence of resistant populations.

  9. Immune modulation by group B Streptococcus influences host susceptibility to urinary tract infection by uropathogenic Escherichia coli.

    Science.gov (United States)

    Kline, Kimberly A; Schwartz, Drew J; Gilbert, Nicole M; Hultgren, Scott J; Lewis, Amanda L

    2012-12-01

    Urinary tract infection (UTI) is most often caused by uropathogenic Escherichia coli (UPEC). UPEC inoculation into the female urinary tract (UT) can occur through physical activities that expose the UT to an inherently polymicrobial periurethral, vaginal, or gastrointestinal flora. We report that a common urogenital inhabitant and opportunistic pathogen, group B Streptococcus (GBS), when present at the time of UPEC exposure, undergoes rapid UPEC-dependent exclusion from the murine urinary tract, yet it influences acute UPEC-host interactions and alters host susceptibility to persistent outcomes of bladder and kidney infection. GBS presence results in increased UPEC titers in the bladder lumen during acute infection and reduced inflammatory responses of murine macrophages to live UPEC or purified lipopolysaccharide (LPS), phenotypes that require GBS mimicry of host sialic acid residues. Taken together, these studies suggest that despite low titers, the presence of GBS at the time of polymicrobial UT exposure may be an overlooked risk factor for chronic pyelonephritis and recurrent UTI in susceptible groups, even if it is outcompeted and thus absent by the time of diagnosis.

  10. Factors influencing the feasibility of laparoscopy colectomy

    Institute of Scientific and Technical Information of China (English)

    He Zhiyun; Zhang Zhongtao

    2014-01-01

    Objective The objective was to review the factors affecting the feasibility of performing successful laparoscopic colectomy.Data sources The literatures about the risk factors closely related to the ability to perform laparoscopic colectomy on different surgical diseases of the colon cited in this review were obtained from PubMed published in English from 2006 to 2012.Study selection Original articles regarding the risk factors that affect the ability to perform laparoscopic colectomy were selected.Results Obesity,diabetes,inflammatory bowel diseases,advanced age,emergency operation,and pelvic anatomy are all important risk factors that increase the risk of developing serious complications such as hemorrhage,anastomotic leak,and skin and soft tissue infections following laparoscopic colectomy.These factors also increase the likelihood of conversion to an open operation.In this study,we reviewed the recent original articles about the relationship of laparoscopic colectomy with these risk factors.We also describe some strategies that limit the likelihood of these complications and the likelihood of conversion to an open operation.Conclusions Obesity,diabetes,inflammatory bowel diseases,age,emergency operation,and pelvic anatomy are all important risk factors that increase the risk of either serious complications or conversion to open operation with laparoscopic colectomy.Evaluation of these risk factors preoperatively should influence the decision to perform colectomy using laparoscopic techniques.

  11. Factors Influencing Tacit Knowledge in Construction

    Directory of Open Access Journals (Sweden)

    Jawahar Nesan

    2012-11-01

    Full Text Available Increased complexity of the construction business and consequentuse of new management concepts and technologies ledconstruction organisations to focus more on the transfer of explicitknowledge. However, it is the tacit knowledge that determinesthe construction companies’ competitiveness in a business thatis driven by turbulent market conditions and customers’ everincreasingdemands. This paper highlights the importance of tacitknowledge sharing in construction, explores the challenges andopportunities to efficiently share tacit knowledge, and based on theliterature review identifies some critical factors that influence tacitknowledge in construction. It is argued that employees’ knowledgesharing (learning behaviours are influenced by work practices thatare borne by respective organisational behaviours. Organisational,cultural, and project characteristics that facilitate knowledgesharing among construction employees are explored and thepractices that influence the construction employee behaviour insharing tacit knowledge are highlighted.

  12. Factors Influencing Tacit Knowledge in Construction

    Directory of Open Access Journals (Sweden)

    Jawahar Nesan

    2012-11-01

    Full Text Available Increased complexity of the construction business and consequentuse of new management concepts and technologies ledconstruction organisations to focus more on the transfer of explicitknowledge. However, it is the tacit knowledge that determinesthe construction companies’ competitiveness in a business thatis driven by turbulent market conditions and customers’ everincreasingdemands. This paper highlights the importance of tacitknowledge sharing in construction, explores the challenges andopportunities to efficiently share tacit knowledge, and based on theliterature review identifies some critical factors that influence tacitknowledge in construction. It is argued that employees’ knowledgesharing (learning behaviours are influenced by work practices thatare borne by respective organisational behaviours. Organisational,cultural, and project characteristics that facilitate knowledgesharing among construction employees are explored and thepractices that influence the construction employee behaviour insharing tacit knowledge are highlighted.

  13. Microencapsulation techniques, factors influencing encapsulation efficiency.

    Science.gov (United States)

    Jyothi, N Venkata Naga; Prasanna, P Muthu; Sakarkar, Suhas Narayan; Prabha, K Surya; Ramaiah, P Seetha; Srawan, G Y

    2010-05-01

    Microencapsulation is one of the quality preservation techniques of sensitive substances and a method for production of materials with new valuable properties. Microencapsulation is a process of enclosing micron-sized particles in a polymeric shell. There are different techniques available for the encapsulation of drug entities. The encapsulation efficiency of the microparticle or microsphere or microcapsule depends upon different factors like concentration of the polymer, solubility of polymer in solvent, rate of solvent removal, solubility of organic solvent in water, etc. The present article provides a literature review of different microencapsulation techniques and different factors influencing the encapsulation efficiency of the microencapsulation technique.

  14. Factors Influencing Consumer Behavior of Smartphone Users

    OpenAIRE

    Nagarkoti, Bishal

    2014-01-01

    The aim of the study is to know about the factors influencing consumer behavior of Smartphone users. Under this study, the main focus is to identify whether Smartphone users buy Smartphone because of their need or wish, reasons to buy expensive smart phones, how social and personal factors affect them to make purchasing decision, for what purposes they use Smartphone, where and how long a day, change in usage of com-puters due to Smartphone and how high is the phone bill after using Smartphon...

  15. FACTORS INFLUENCING BENDING RIGIDITY OF SUBMERGED VEGETATION

    Institute of Scientific and Technical Information of China (English)

    WU Long-hua; YANG Xiao-li

    2011-01-01

    The bending rigidity of submerged vegetation is closely related with vegetative drag force.This work aims at determining the effects of flow conditions and characteristics of vegetation on the bending rigidity of submerged vegetation.Based on the dimensional analysis method,the factors influencing the bending rigidity of individual submerged vegetation were analyzed.The relationship between the relative bending rigidity and its influencing factors was investigated by experimental observation,and a relative bending rigidity expression for submerged vegetation was obtained by means of multiple linear regression method.The results show that the submerged vegetation has three states under different inflow conditions,and the each critical relative bending rigidity of individual submerged vegetation was determined for the different states of submerged vegetation.

  16. Investigating different factors influencing on brand equity

    Directory of Open Access Journals (Sweden)

    Afsane Zamanimoghadam

    2014-07-01

    Full Text Available The purpose of this paper is to determine and prioritize factors influencing on brand equity in consumer’s point of view for a case study of Samsung appliance consumers in city of Tehran, Iran. The study investigates the effects of four factors in terms of the customer's perspective, price, advertisement, family and brand image, by dimensions of brand equity, perceived quality, brand awareness, brand association, brand loyalty, on brand equity. The research method is based on a descriptive-survey research. The questionnaire includes Samsung consumers in city of Tehran, Iran. To test the hypotheses, SPSS and LISREL software packages are used. For data analysis, descriptive statistics and inferential statistical tests including structural equation modeling and path analysis are used. The results of the survey have indicated that family and brand image influence positively on brand equity but the effects of advertisement and price on brand equity were not confirmed.

  17. Influence of synthesis conditions and mesoporous structures on the gold nanoparticles supported on mesoporous silica hosts

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byunghwan [Korea Institute of Industrial Technology, ChonAn, Korea; Ma, Zhen [ORNL; Zhang, Zongtao [ORNL; Park, Chulhwan [Kwangwoon University; Dai, Sheng [ORNL

    2009-01-01

    Loading gold on mesoporous materials via different methods has been actively attempted in the literature, but the knowledge about the influences of synthesis details and different mesoporous structures on the size and thermal stability of gold nanoparticles supported on mesoporous hosts is still limited. In this study, Au/HMS, Au/MCM-41, Au/MCM-48, Au/SBA-15, and Au/SBA-16 samples were prepared by modifying a variety of mesoporous silicas by amine ligands followed by loading HAuCl4 and calcination. The influences of different amine ligands ((3-aminopropyl)triethoxysilane versus N-[3-(trimethoxysilyl)propyl]ethylenediamine), solvents (water versus ethanol), calcination temperatures (200 or 550 C), and mesoporous structures on the size of supported gold nanoparticles were systematically investigated employing nitrogen adsorption-desorption measurement, X-ray diffraction (XRD), diffuse reflectance UV-vis spectroscopy, and transmission electron microscopy (TEM). Interestingly, while big and irregular gold particles situate on MCM-48 with bicontinuous three-dimensional pore structure and relatively small pore size (2.4 nm) upon calcination at 550 C, homogeneous and small gold nanoparticles maintain inside SBA-15 with one-dimensional pore structure and relatively big pore size (6.8 nm). Apparently, the pore structure and pore size of mesoporous silica hosts play a key role in determining the size and thermal stability of the supported gold nanoparticles. Our results may provide some useful clues for the rational design of supported metal catalysts by choosing suitable mesoporous hosts.

  18. Odours of Plasmodium falciparum-infected participants influence mosquito-host interactions.

    Science.gov (United States)

    de Boer, Jetske G; Robinson, Ailie; Powers, Stephen J; Burgers, Saskia L G E; Caulfield, John C; Birkett, Michael A; Smallegange, Renate C; van Genderen, Perry J J; Bousema, Teun; Sauerwein, Robert W; Pickett, John A; Takken, Willem; Logan, James G

    2017-08-24

    Malaria parasites are thought to influence mosquito attraction to human hosts, a phenomenon that may enhance parasite transmission. This is likely mediated by alterations in host odour because of its importance in mosquito host-searching behaviour. Here, we report that the human skin odour profile is affected by malaria infection. We compared the chemical composition and attractiveness to Anopheles coluzzii mosquitoes of skin odours from participants that were infected by Controlled Human Malaria Infection with Plasmodium falciparum. Skin odour composition differed between parasitologically negative and positive samples, with positive samples collected on average two days after parasites emerged from the liver into the blood, being associated with low densities of asexual parasites and the absence of gametocytes. We found a significant reduction in mosquito attraction to skin odour during infection for one experiment, but not in a second experiment, possibly due to differences in parasite strain. However, it does raise the possibility that infection can affect mosquito behaviour. Indeed, several volatile compounds were identified that can influence mosquito behaviour, including 2- and 3-methylbutanal, 3-hydroxy-2-butanone, and 6-methyl-5-hepten-2-one. To better understand the impact of our findings on Plasmodium transmission, controlled studies are needed in participants with gametocytes and higher parasite densities.

  19. Factors Influencing Impulse Buying in Retail Stores

    OpenAIRE

    Giorgadze, Nino

    2014-01-01

    Impulse buying is a widely pervasive phenomenon. Statistics shows that more and more shoppers are experiencing irresistible urge to purchase unplanned and in most cases unnecessary product. Existing researches fall short in identifying most suitable tools that marketers can adopt in order to promote impulsive sales. Therefore, this thesis provides deep analysis of those, controllable factors that influence impulse buying. Particularly four external cues are examined: product display, promotio...

  20. Major Factors influences the 2008 Stock Market

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ 2007 was an unusual year for China's stock market, as the index climbed from 2675 points up to 6124 by the end of the year, setting new records again and again throughout 2007. What will happen to the stock market in the coming 2008? Let's havea look at some of the main factors that will influence the stock market this year, perhaps we can find out if 2008 will be another memorable year full of surprises.

  1. Factors influencing the eicosanoids synthesis in vivo.

    Science.gov (United States)

    Szefel, Jarosław; Kruszewski, Wiesław Janusz; Sobczak, Ewa

    2015-01-01

    External factors activate a sequence of reactions involving the reception, transduction, and transmission of signals to effector cells. There are two main phases of the body's reaction to harmful factors: the first aims to neutralize the harmful factor, while in the second the inflammatory process is reduced in size and resolved. Secondary messengers such as eicosanoids are active in both phases. The discovery of lipoxins and epi-lipoxins demonstrated that not all arachidonic acid (AA) derivatives have proinflammatory activity. It was also revealed that metabolites of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) such as resolvins, protectins, and maresins also take part in the resolution of inflammation. Knowledge of the above properties has stimulated several clinical trials on the influence of EPA and DHA supplementation on various diseases. However, the equivocal results of those trials prevent the formulation of guidelines on EPA and DHA supplementation. Prescription drugs are among the substances with the strongest influence on the profile and quantity of the synthesized eicosanoids. The lack of knowledge about their influence on the conversion of EPA and DHA into eicosanoids may lead to erroneous conclusions from clinical trials.

  2. Identification of FAM111A as an SV40 host range restriction and adenovirus helper factor.

    Directory of Open Access Journals (Sweden)

    Debrah A Fine

    Full Text Available The small genome of polyomaviruses encodes a limited number of proteins that are highly dependent on interactions with host cell proteins for efficient viral replication. The SV40 large T antigen (LT contains several discrete functional domains including the LXCXE or RB-binding motif, the DNA binding and helicase domains that contribute to the viral life cycle. In addition, the LT C-terminal region contains the host range and adenovirus helper functions required for lytic infection in certain restrictive cell types. To understand how LT affects the host cell to facilitate viral replication, we expressed full-length or functional domains of LT in cells, identified interacting host proteins and carried out expression profiling. LT perturbed the expression of p53 target genes and subsets of cell-cycle dependent genes regulated by the DREAM and the B-Myb-MuvB complexes. Affinity purification of LT followed by mass spectrometry revealed a specific interaction between the LT C-terminal region and FAM111A, a previously uncharacterized protein. Depletion of FAM111A recapitulated the effects of heterologous expression of the LT C-terminal region, including increased viral gene expression and lytic infection of SV40 host range mutants and adenovirus replication in restrictive cells. FAM111A functions as a host range restriction factor that is specifically targeted by SV40 LT.

  3. A Review of Factors Influencing Health Inequalities

    Directory of Open Access Journals (Sweden)

    Hassan Almaspoor Khanghah

    2016-01-01

    Full Text Available ​Background and Objectives : Inequity in health is a universal term which is used for showing current differences, variations and inequalities of people in accessing to health services. The current study aimed to assess the factors influencing health inequalities to present the results to the researchers and health care professionals. Material and Methods : In this review, several databases including PubMed, Proquest, Scopus, Google Scholar search engine, SID and IranDoc were searched within 2000-2014 period. We found 746 articles and refined them step by step according to the aim of the study by reviewing the titles, abstracts and full texts. Finally, 16 articles were selected for further study Results: In the present study, identified determinants in health inequalities were as follows: 1- Economic and income factors 2- Political factors, social and public policy 3- Cultural and social values 4- social and demographic factors 5- Behavioral, psychological and biological factors. Although, other factors like governmental, international, social cohesion, incidents and even the health system itself were involved in health inequalities, but the listed determinants were among the most important determinants in health inequalities in the conducted studies. Conclusion : Given the importance of people's health and inequalities in health, the approach should focus on reducing the inequalities in all policies and development programs and the role of these factors should be taken into consideration by managers and policy-makers

  4. A Supramolecular Host-Guest Carrier System for Growth Factors Employing VHH Fragments

    NARCIS (Netherlands)

    Cabanas-Danés, J.; Rodrigues, E.D.; Landman, Ellie B.M.; Weerd, van J.; Blitterswijk, van C.A.; Verrips, T.; Huskens, J.; Karperien, H.B.J.; Jonkheijm, Pascal

    2014-01-01

    A supramolecular strategy is presented for the assembly of growth factors employing His6-tagged single-domain antibodies (VHH). A combination of orthogonal supramolecular interactions of β-cyclodextrin (βCD)-adamantyl (Ad) host-guest and N-nitrilotriacetic acid (NTA)-histidine (His) interactions was

  5. Host-related factors explaining interindividual variability of carotenoid bioavailability and tissue concentrations in humans

    NARCIS (Netherlands)

    Bohn, Torsten; Desmarchelier, Charles; Dragsted, Lars O.; Nielsen, Charlotte S.; Stahl, Wilhelm; Rühl, Ralph; Keijer, Jaap; Borel, Patrick

    2017-01-01

    Carotenoid dietary intake and their endogenous levels have been associated with a decreased risk of several chronic diseases. There are indications that carotenoid bioavailability depends, in addition to the food matrix, on host factors. These include diseases (e.g. colitis), life-style habits (e

  6. Distinct immunoregulatory properties of macrophage migration inhibitory factors encoded by Eimeria parasites and their chicken host

    Science.gov (United States)

    Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that plays an important role in host defense against a variety of microorganisms including protozoan parasites. Interestingly, some microbial pathogens also express a MIF-like protein, although its role in disease pathogenesi...

  7. Influence of host chloroplast proteins on Tobacco mosaic virus accumulation and intercellular movement.

    Science.gov (United States)

    Bhat, Sumana; Folimonova, Svetlana Y; Cole, Anthony B; Ballard, Kimberly D; Lei, Zhentian; Watson, Bonnie S; Sumner, Lloyd W; Nelson, Richard S

    2013-01-01

    Tobacco mosaic virus (TMV) forms dense cytoplasmic bodies containing replication-associated proteins (virus replication complexes [VRCs]) upon infection. To identify host proteins that interact with individual viral components of VRCs or VRCs in toto, we isolated viral replicase- and VRC-enriched fractions from TMV-infected Nicotiana tabacum plants. Two host proteins in enriched fractions, ATP-synthase γ-subunit (AtpC) and Rubisco activase (RCA) were identified by matrix-assisted laser-desorption ionization time-of-flight mass spectrometry or liquid chromatography-tandem mass spectrometry. Through pull-down analysis, RCA bound predominantly to the region between the methyltransferase and helicase domains of the TMV replicase. Tobamovirus, but not Cucumber mosaic virus or Potato virus X, infection of N. tabacum plants resulted in 50% reductions in Rca and AtpC messenger RNA levels. To investigate the role of these host proteins in TMV accumulation and plant defense, we used a Tobacco rattle virus vector to silence these genes in Nicotiana benthamiana plants prior to challenge with TMV expressing green fluorescent protein. TMV-induced fluorescent lesions on Rca- or AtpC-silenced leaves were, respectively, similar or twice the size of those on leaves expressing these genes. Silencing Rca and AtpC did not influence the spread of Tomato bushy stunt virus and Potato virus X. In AtpC- and Rca-silenced leaves TMV accumulation and pathogenicity were greatly enhanced, suggesting a role of both host-encoded proteins in a defense response against TMV. In addition, silencing these host genes altered the phenotype of the TMV infection foci and VRCs, yielding foci with concentric fluorescent rings and dramatically more but smaller VRCs. The concentric rings occurred through renewed virus accumulation internal to the infection front.

  8. Host life history strategy, species diversity, and habitat influence Trypanosoma cruzi vector infection in Changing landscapes.

    Directory of Open Access Journals (Sweden)

    Nicole L Gottdenker

    Full Text Available BACKGROUND: Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama. METHODOLOGY/PRINCIPAL FINDINGS: R. pallescens vectors (N = 643 were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3% vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3% dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as r(max, the maximum intrinsic rate of population increase, and habitat type (forest fragments and peridomiciliary sites were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of r(max were positively associated with higher vector infection rate at a site. CONCLUSIONS/SIGNIFICANCE: In this study, anthropogenic landscape disturbance increased vector infection with T

  9. CREDIT LEVEL INFLUENCING FACTORS AT HUNGARIAN FARMS

    Directory of Open Access Journals (Sweden)

    Toth Jozsef

    2012-12-01

    Full Text Available In this paper we estimate the impact of different factors on creditability of agricultural farms. According to the literature the collateral (tangible assets, the farm size, productivity, and subsidies should have significant effects on farm loans. We use data from the Hungarian Farm Accountancy Data Network to test our two hypotheses and theoretical assumptions for the period 2001-2010. Because of using panel data, we do our estimations using fixed effects econometrics model to test our assumptions. The results indicate that the chosen factors have significant influence on total liabilities and short- and long-term loans as well. With specially interest of subsidies the growing level of supports decrease the need of other financial tools. At output factors (inclusive farm size have significant and positive effect, same as collateral (tangible assets.

  10. Internal factors influencing the knowledge continuity ensuring

    Directory of Open Access Journals (Sweden)

    Hana Urbancová

    2012-01-01

    Full Text Available The aim of the systematic ensuring of knowledge continuity is the continuity of an organisation’s development, the quality of managerial positions and the continuity of decision-making. By ensuring knowledge continuity, organisations may gain a performance-enhancing factor. The objective of the article is to identify the level of impact of decisive internal factors determining knowledge continuity ensuring and contributing to the efficiency of the organisations. Knowledge continuity ensuring as an internal force, however, can together with the right employees, help adapt more quickly to external conditions that organisations can hardly control. Monitoring and ensuring knowledge continuity can contribute to a higher quality of processes in general, in particular processes exploiting knowledge, and thus help improve the level of management. The first part of the article presents theoretical views on the aspects of knowledge continuity ensuring in organisations while the second part analyses the findings of the surveys carried out among managers in organisations in the Czech Republic. Based on the summary of the outcomes obtained it is possible to say that internal factors influence knowledge continuity ensuring in organisations, however, the level of impact of individual factors is determined by their size. The findings regarding the impact of each of the factors show that the most significant barriers to knowledge continuity ensuring are those associated with the human factor.

  11. Structural determinants of host specificity of complement Factor H recruitment by Streptococcus pneumoniae.

    Science.gov (United States)

    Achila, David; Liu, Aizhuo; Banerjee, Rahul; Li, Yue; Martinez-Hackert, Erik; Zhang, Jing-Ren; Yan, Honggao

    2015-01-15

    Many human pathogens have strict host specificity, which affects not only their epidemiology but also the development of animal models and vaccines. Complement Factor H (FH) is recruited to pneumococcal cell surface in a human-specific manner via the N-terminal domain of the pneumococcal protein virulence factor choline-binding protein A (CbpAN). FH recruitment enables Streptococcus pneumoniae to evade surveillance by human complement system and contributes to pneumococcal host specificity. The molecular determinants of host specificity of complement evasion are unknown. In the present study, we show that a single human FH (hFH) domain is sufficient for tight binding of CbpAN, present the crystal structure of the complex and identify the critical structural determinants for host-specific FH recruitment. The results offer new approaches to the development of better animal models for pneumococcal infection and redesign of the virulence factor for pneumococcal vaccine development and reveal how FH recruitment can serve as a mechanism for both pneumococcal complement evasion and adherence.

  12. Bovine Host Genetic Variation Influences Rumen Microbial Methane Production with Best Selection Criterion for Low Methane Emitting and Efficiently Feed Converting Hosts Based on Metagenomic Gene Abundance.

    Directory of Open Access Journals (Sweden)

    Rainer Roehe

    2016-02-01

    Full Text Available Methane produced by methanogenic archaea in ruminants contributes significantly to anthropogenic greenhouse gas emissions. The host genetic link controlling microbial methane production is unknown and appropriate genetic selection strategies are not developed. We used sire progeny group differences to estimate the host genetic influence on rumen microbial methane production in a factorial experiment consisting of crossbred breed types and diets. Rumen metagenomic profiling was undertaken to investigate links between microbial genes and methane emissions or feed conversion efficiency. Sire progeny groups differed significantly in their methane emissions measured in respiration chambers. Ranking of the sire progeny groups based on methane emissions or relative archaeal abundance was consistent overall and within diet, suggesting that archaeal abundance in ruminal digesta is under host genetic control and can be used to genetically select animals without measuring methane directly. In the metagenomic analysis of rumen contents, we identified 3970 microbial genes of which 20 and 49 genes were significantly associated with methane emissions and feed conversion efficiency respectively. These explained 81% and 86% of the respective variation and were clustered in distinct functional gene networks. Methanogenesis genes (e.g. mcrA and fmdB were associated with methane emissions, whilst host-microbiome cross talk genes (e.g. TSTA3 and FucI were associated with feed conversion efficiency. These results strengthen the idea that the host animal controls its own microbiota to a significant extent and open up the implementation of effective breeding strategies using rumen microbial gene abundance as a predictor for difficult-to-measure traits on a large number of hosts. Generally, the results provide a proof of principle to use the relative abundance of microbial genes in the gastrointestinal tract of different species to predict their influence on traits e

  13. Bovine Host Genetic Variation Influences Rumen Microbial Methane Production with Best Selection Criterion for Low Methane Emitting and Efficiently Feed Converting Hosts Based on Metagenomic Gene Abundance.

    Science.gov (United States)

    Roehe, Rainer; Dewhurst, Richard J; Duthie, Carol-Anne; Rooke, John A; McKain, Nest; Ross, Dave W; Hyslop, Jimmy J; Waterhouse, Anthony; Freeman, Tom C; Watson, Mick; Wallace, R John

    2016-02-01

    Methane produced by methanogenic archaea in ruminants contributes significantly to anthropogenic greenhouse gas emissions. The host genetic link controlling microbial methane production is unknown and appropriate genetic selection strategies are not developed. We used sire progeny group differences to estimate the host genetic influence on rumen microbial methane production in a factorial experiment consisting of crossbred breed types and diets. Rumen metagenomic profiling was undertaken to investigate links between microbial genes and methane emissions or feed conversion efficiency. Sire progeny groups differed significantly in their methane emissions measured in respiration chambers. Ranking of the sire progeny groups based on methane emissions or relative archaeal abundance was consistent overall and within diet, suggesting that archaeal abundance in ruminal digesta is under host genetic control and can be used to genetically select animals without measuring methane directly. In the metagenomic analysis of rumen contents, we identified 3970 microbial genes of which 20 and 49 genes were significantly associated with methane emissions and feed conversion efficiency respectively. These explained 81% and 86% of the respective variation and were clustered in distinct functional gene networks. Methanogenesis genes (e.g. mcrA and fmdB) were associated with methane emissions, whilst host-microbiome cross talk genes (e.g. TSTA3 and FucI) were associated with feed conversion efficiency. These results strengthen the idea that the host animal controls its own microbiota to a significant extent and open up the implementation of effective breeding strategies using rumen microbial gene abundance as a predictor for difficult-to-measure traits on a large number of hosts. Generally, the results provide a proof of principle to use the relative abundance of microbial genes in the gastrointestinal tract of different species to predict their influence on traits e.g. human metabolism

  14. Environmental factors influencing the development of atherosclerosis

    Directory of Open Access Journals (Sweden)

    Andrzej Brodziak

    2013-12-01

    Full Text Available The aim of the paper is to present an overview of recent findings on the environmental and behavioral factors influencing the development of atherosclerosis. The authors primarily concentrated on deliberations of possibile main causes of the damage of the endothelium. At the same time the following pathogenic mechanisms as cellular dysfunction, inflammation and coagulation disorders have been enumerated. The links between the state of the vascular endothelium and life style have been emphasized. It is also important to note that the primary causes of the endothelial damage should be traced as originally suggested many years ago viewing such factors as anger, hostility, aggression, impulsiveness and depression but with a new approach. The authors supplement the comments, on the environmental factors influencing the development of atherosclerosis, with basic data on family predisposition to the development of this disease. They highlight that current genetic research have not determined genes responsible for atheroscelosis. According to the authors the considerations and conclusions presented in this overview are important for the educational purposes related to the most frequent disease process resulting in many diseases in medical disciplines.

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

    Science.gov (United States)

    Memišević, Vesna; Zavaljevski, Nela; Pieper, Rembert; Rajagopala, Seesandra V.; Kwon, Keehwan; Townsend, Katherine; Yu, Chenggang; Yu, Xueping; DeShazer, David; Reifman, Jaques; Wallqvist, Anders

    2013-01-01

    Burkholderia mallei is an infectious intracellular pathogen whose virulence and resistance to antibiotics makes it a potential bioterrorism agent. Given its genetic origin as a commensal soil organism, it is equipped with an extensive and varied set of adapted mechanisms to cope with and modulate host-cell environments. One essential virulence mechanism constitutes the specialized secretion systems that are designed to penetrate host-cell membranes and insert pathogen proteins directly into the host cell's cytosol. However, the secretion systems' proteins and, in particular, their host targets are largely uncharacterized. Here, we used a combined in silico, in vitro, and in vivo approach to identify B. mallei proteins required for pathogenicity. We used bioinformatics tools, including orthology detection and ab initio predictions of secretion system proteins, as well as published experimental Burkholderia data to initially select a small number of proteins as putative virulence factors. We then used yeast two-hybrid assays against normalized whole human and whole murine proteome libraries to detect and identify interactions among each of these bacterial proteins and host proteins. Analysis of such interactions provided both verification of known virulence factors and identification of three new putative virulence proteins. We successfully created insertion mutants for each of these three proteins using the virulent B. mallei ATCC 23344 strain. We exposed BALB/c mice to mutant strains and the wild-type strain in an aerosol challenge model using lethal B. mallei doses. In each set of experiments, mice exposed to mutant strains survived for the 21-day duration of the experiment, whereas mice exposed to the wild-type strain rapidly died. Given their in vivo role in pathogenicity, and based on the yeast two-hybrid interaction data, these results point to the importance of these pathogen proteins in modulating host ubiquitination pathways, phagosomal escape, and actin

  16. Contextual factors influencing research use in nursing.

    Science.gov (United States)

    French, Beverley

    2005-01-01

    Contextual factors are perceived to be significant barriers to research-utilisation-related activity, but little is known about how context impacts on specific research-based decisions, or how the individual interacts with the organisation in the requirement for research-based change. This study describes the impact of contextual factors on the practical reasoning of nurse specialists in the construction of policy for practice. Three groups of clinical nurse specialists were observed during a series of meetings convened to construct evidence-based guidelines for nursing practice. Transcripts of the meetings were analysed to identify and categorise the physical, social, political, and economic influences on 31 nursing issues. Multiple contextual factors influenced each decision made, with decisions about nursing practice bounded by setting and system considerations, relationships with others in the care team, and resource constraints. Practitioners were involved in weighing up alternative scenarios, contexts, and contingencies for each decision, requiring strategies to adapt and reconstruct the nature of care, to influence others, and to affect organisational decision-making processes. The practical accomplishment of evidence-based practice required diverse skills: translating between evidence and practice; mediating the values, preferences, and working practices of multiple stakeholders; negotiating organisational complexity and the management of boundaries; and coordinating inter-organisational and inter-agency working. Nurse specialists in this study had a significant role in instigating, fuelling, and coordinating policy review, predominantly by communication across professional and organisational boundaries. Clinical specialists acting as organisational boundary spanners require skills in the informal cultural work of organising, facilitating, and maintaining links across professional, team, and organisational boundaries. If their role in the negotiation of

  17. Influence of selected factors on induced syneresis

    Directory of Open Access Journals (Sweden)

    Jovanović Snežana T.

    2004-01-01

    Full Text Available Syneresis is the process of whey separation induced by gel contraction resulting in rearranging or restructuring of casein matrix formed during enzymatic coagulation. Numerous factors can influence the process of syneresis. The influences of pH, calcium concentration, temperature of coagulation of milk and applied heat treatment on the syneresis induced by different intensity of centrifugal force have been investigated. Coagulated samples were centrifuged at 1000, 2000 and 3000 rpm for 5 min, respectively. Reconstituted skim milk powder (control sample and reconstituted non-fat milk heat treated at 87ºC/10 min (experimental sample are coagulated at temperatures of 30ºC and 35ºC, at pH value of 5.8 and 6.2, and with the addition of 100, 200 and 400 mg/l of CaCl2, respectively. Centrifugation at 1000 rpm of both control and experimental samples didn’t recover any sera, regardless of the applied coagulation conditions. This indicates that the intensity of centrifugal force wasn’t strong enough to disrupt gel structure and cause syneresis. When the intensity of centrifugal force was increased up to 2000 rpm, the syneresis was induced, but the degree of syneresis depended on the applied factors of coagulation, primary on the applied heat treatments and temperature of coagulation. The amount of added CaCl2 didn’t have a significant influence on the induced syneresis at 2000 rpm. The induced syneresis was very significant for both control and experimental samples when the intensity of centrifugal force of 3000 rpm was applied. It was also noted that curd produced from heat treated milk in which milk protein coaggregates were formed, released less sera regardless of the applied coagulation factors.

  18. Factors influencing aircraft ground handling performance

    Science.gov (United States)

    Yager, T. J.

    1983-01-01

    Problems associated with aircraft ground handling operations on wet runways are discussed and major factors which influence tire/runway braking and cornering traction capability are identified including runway characteristics, tire hydroplaning, brake system anomalies, and pilot inputs. Research results from tests with instrumented ground vehicles and aircraft, and aircraft wet runway accident investigation are summarized to indicate the effects of different aircraft, tire, and runway parameters. Several promising means are described for improving tire/runway water drainage capability, brake system efficiency, and pilot training to help optimize aircraft traction performance on wet runways.

  19. Asynchronous development of honey bee host and Varroa destructor (Mesostigmata: Varroidae) influences reproductive potential of mites.

    Science.gov (United States)

    Kirrane, Maria J; De Guzman, Lilia I; Rinderer, Thomas E; Frake, Amanda M; Wagnitz, Jeremy; Whelan, Pádraig M

    2011-08-01

    A high proportion of nonreproductive (NR) Varroa destructor Anderson & Trueman (Mesostigmata: Varroidae), is commonly observed in honey bee colonies displaying the varroa sensitive hygienic trait (VSH). This study was conducted to determine the influence of brood removal and subsequent host reinvasion of varroa mites on mite reproduction. We collected foundress mites from stages of brood (newly sealed larvae, prepupae, white-eyed pupae, and pink-eyed pupae) and phoretic mites from adult bees. We then inoculated these mites into cells containing newly sealed larvae. Successful reproduction (foundress laid both a mature male and female) was low (13%) but most common in mites coming from sealed larvae. Unsuccessful reproductive attempts (foundress failed to produce both a mature male and female) were most common in mites from sealed larvae (22%) and prepupae (61%). Lack of any progeny was most common for mites from white-eyed (83%) and pink-eyed pupae (92%). We also collected foundress mites from sealed larvae and transferred them to cells containing newly sealed larvae, prepupae, white-eyed pupae, or pink-eyed pupae. Successful reproduction only occurred in the transfers to sealed larvae (26%). Unsuccessful reproductive attempts were most common in transfers to newly sealed larvae (40%) and to prepupae (25%). Unsuccessful attempts involved the production of immature progeny (60%), the production of only mature daughters (26%) or the production of only a mature male (14%). Generally, lack of progeny was not associated with mites having a lack of stored sperm. Our results suggest that mites exposed to the removal of prepupae or older brood due to hygiene are unlikely to produce viable mites if they invade new hosts soon after brood removal. Asynchrony between the reproductive status of reinvading mites and the developmental stage of their reinvasion hosts may be a primary cause of NR mites in hygienic colonies. Even if reinvading mites use hosts having the proper age

  20. Quantitative Proteomics Identifies Serum Response Factor Binding Protein 1 as a Host Factor for Hepatitis C Virus Entry

    Directory of Open Access Journals (Sweden)

    Gisa Gerold

    2015-08-01

    Full Text Available Hepatitis C virus (HCV enters human hepatocytes through a multistep mechanism involving, among other host proteins, the virus receptor CD81. How CD81 governs HCV entry is poorly characterized, and CD81 protein interactions after virus binding remain elusive. We have developed a quantitative proteomics protocol to identify HCV-triggered CD81 interactions and found 26 dynamic binding partners. At least six of these proteins promote HCV infection, as indicated by RNAi. We further characterized serum response factor binding protein 1 (SRFBP1, which is recruited to CD81 during HCV uptake and supports HCV infection in hepatoma cells and primary human hepatocytes. SRFBP1 facilitates host cell penetration by all seven HCV genotypes, but not of vesicular stomatitis virus and human coronavirus. Thus, SRFBP1 is an HCV-specific, pan-genotypic host entry factor. These results demonstrate the use of quantitative proteomics to elucidate pathogen entry and underscore the importance of host protein-protein interactions during HCV invasion.

  1. Factors influencing the cardiac MIBG accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Takatsu, Hisato; Fujiwara, Hisayoshi [Gifu Univ. (Japan). School of Medicine

    1997-02-01

    Following factors possibly influencing the cardiac MIBG accumulation were examined mainly in mice. 1. The specific activity of the MIBG (meta-iodo-benzyl guanidine) on the neuronal and non-neuronal fractions. 2. Motor restriction stress on MIBG accumulation and washout. 3. Loading and restriction of sodium chloride on the accumulation and effect of suppression of renin-angiotensin system. 4. Examinations in Dahl rats. 125I- or 131I-MIBG was intravenously administered to mice at 74 kBq. At 30 min or 4 hr after administration, mice were sacrificed and their left ventricles were dissected out for measurement of radioactivity in a liquid scintillation counter. Salt-sensitive and -resistant Dahl rats were given with 37 MBq of 123I-MIBG and cardiac radioactivity was measured externally for calculation of washout. Factors examined were found highly correlated with the accumulation of MIBG and measurement of its washout was considered useful for evaluating sympathetic activity. (K.H.)

  2. A survey on factors influencing city branding

    Directory of Open Access Journals (Sweden)

    Seyed Mohsen Mahmoudzadeh

    2014-10-01

    Full Text Available Nowadays, the issue of “globalization” is entering to all areas in the world. In addition to products and companies, cities and countries also have the opportunity to see themselves as important actors in international arena. Places define their positions in different fields like business, leisure and recreation, educational opportunities, living, etc. This paper presents an empirical study to introduce city branding as one of the solutions to join globalization process. The method of this research is based on the “descriptive-analytic” and utilize the available literature and experts’ opinions to prioritize the influencing factors of city branding. We use Delphi consensus methods and technique of analytical hierarchy process to evaluate the factors. Finally, the results of the study indicate that security, transportation and mental creativity are the weakest fields and business and shopping facilities are strong fields of city branding in metropolitan of Tehran.

  3. Influence of habitat pattern on orientation during host fruit location in the tomato fruit fly, Neoceratitis cyanescens.

    Science.gov (United States)

    Brévault, T; Quilici, S

    2007-12-01

    Fruit flies have evolved mechanisms using olfactory and visual signals to find and recognize suitable host plants. The objective of the present study was to determine how habitat patterns may assist fruit flies in locating host plants and fruit. The tomato fruit fly, Neoceratitis cyanescens (Bezzi), was chosen as an example of a specialized fruit fly, attacking plants of the Solanaceae family. A series of experiments was conducted in an outdoor field cage wherein flies were released and captured on sticky orange and yellow spheres displayed in pairs within or above potted host or non-host plants. Bright orange spheres mimicking host fruit were significantly more attractive than yellow spheres only when placed within the canopy of host plants and not when either within non-host plants or above both types of plants. Additional experiments combining sets of host and non-host plants in the same cage, or spraying leaf extract of host plant (bug weed) on non-host plants showed that volatile cues emitted by the foliage of host plants may influence the visual response of flies in attracting mature females engaged in a searching behaviour for a laying site and in assisting them to find the host fruit. Moreover, the response was specific to mature females with a high oviposition drive because starved mature females, immature females and males showed no significant preference for orange spheres. Olfactory signals emitted by the host foliage could be an indicator of an appropriate habitat, leading flies to engage in searching for a visual image.

  4. A study of factors influencing advanced puberty

    Directory of Open Access Journals (Sweden)

    Yong Jun Park

    2010-02-01

    Full Text Available Purpose : The purpose of this study was to evaluate the timing of puberty and the factors inducing advanced puberty in elemental school students of low grades. Methods : The 1st, 2nd, and 3rd grade elemental students from the Goyang province were randomly selected, and their sexual maturation rate was assessed by physical examination. After obtaining an informed consent, a questionnaire was administered to the parents; eating habits, lifestyle, use of growth-inducing medication, and present illness of the students were evaluated to determine the factors that induced advanced puberty. The data were statistically analyzed. Results : We selected 170 children and the girls:boys sex ratio was 1.2:1. Two 9-year-old boys were in genital stage 2. Two (14.3% 6-year-old girls, 6 (19.4% 7-year-old girls, 15 (39.6% 8-year-old girls, and 4 (57.1% 9-year-old girls were in breast stage 2. The average pubertal timing predicted for girls was 9.11¡?#?.86; years. The main factors influencing pubertal timing were obesity scale, frequency of eating fast food, and the use of growth-inducing medication. A high rating on the obesity scale and high frequency of eating fast food indicated advanced stage of puberty. Growth-inducing medication induced puberty through obesity. Conclusion : We proposed that predictive average pubertal timing in girls was 9.11¡?#?.86; years, which was consistent with the previously reported findings from abroad. The significant influencing factors in advanced puberty were obesity scale and frequency of fast food.

  5. Visual Genome-Wide RNAi Screening to Identify Human Host Factors Required for Trypanosoma cruzi Infection

    Science.gov (United States)

    de Macedo Dossin, Fernando; Choi, Seo Yeon; Kim, Nam Youl; Kim, Hi Chul; Jung, Sung Yong; Schenkman, Sergio; Almeida, Igor C.; Emans, Neil; Freitas-Junior, Lucio H.

    2011-01-01

    The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical infection that affects millions of people in the Americas. Current chemotherapy relies on only two drugs that have limited efficacy and considerable side effects. Therefore, the development of new and more effective drugs is of paramount importance. Although some host cellular factors that play a role in T. cruzi infection have been uncovered, the molecular requirements for intracellular parasite growth and persistence are still not well understood. To further study these host-parasite interactions and identify human host factors required for T. cruzi infection, we performed a genome-wide RNAi screen using cellular microarrays of a printed siRNA library that spanned the whole human genome. The screening was reproduced 6 times and a customized algorithm was used to select as hits those genes whose silencing visually impaired parasite infection. The 162 strongest hits were subjected to a secondary screening and subsequently validated in two different cell lines. Among the fourteen hits confirmed, we recognized some cellular membrane proteins that might function as cell receptors for parasite entry and others that may be related to calcium release triggered by parasites during cell invasion. In addition, two of the hits are related to the TGF-beta signaling pathway, whose inhibition is already known to diminish levels of T. cruzi infection. This study represents a significant step toward unveiling the key molecular requirements for host cell invasion and revealing new potential targets for antiparasitic therapy. PMID:21625474

  6. Visual genome-wide RNAi screening to identify human host factors required for Trypanosoma cruzi infection.

    Directory of Open Access Journals (Sweden)

    Auguste Genovesio

    Full Text Available The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical infection that affects millions of people in the Americas. Current chemotherapy relies on only two drugs that have limited efficacy and considerable side effects. Therefore, the development of new and more effective drugs is of paramount importance. Although some host cellular factors that play a role in T. cruzi infection have been uncovered, the molecular requirements for intracellular parasite growth and persistence are still not well understood. To further study these host-parasite interactions and identify human host factors required for T. cruzi infection, we performed a genome-wide RNAi screen using cellular microarrays of a printed siRNA library that spanned the whole human genome. The screening was reproduced 6 times and a customized algorithm was used to select as hits those genes whose silencing visually impaired parasite infection. The 162 strongest hits were subjected to a secondary screening and subsequently validated in two different cell lines. Among the fourteen hits confirmed, we recognized some cellular membrane proteins that might function as cell receptors for parasite entry and others that may be related to calcium release triggered by parasites during cell invasion. In addition, two of the hits are related to the TGF-beta signaling pathway, whose inhibition is already known to diminish levels of T. cruzi infection. This study represents a significant step toward unveiling the key molecular requirements for host cell invasion and revealing new potential targets for antiparasitic therapy.

  7. Host Cell Factors in Filovirus Entry: Novel Players, New Insights

    Directory of Open Access Journals (Sweden)

    Stefan Pöhlmann

    2012-11-01

    Full Text Available Filoviruses cause severe hemorrhagic fever in humans with high case-fatality rates. The cellular factors exploited by filoviruses for their spread constitute potential targets for intervention, but are incompletely defined. The viral glycoprotein (GP mediates filovirus entry into host cells. Recent studies revealed important insights into the host cell molecules engaged by GP for cellular entry. The binding of GP to cellular lectins was found to concentrate virions onto susceptible cells and might contribute to the early and sustained infection of macrophages and dendritic cells, important viral targets. Tyrosine kinase receptors were shown to promote macropinocytic uptake of filoviruses into a subset of susceptible cells without binding to GP, while interactions between GP and human T cell Ig mucin 1 (TIM-1 might contribute to filovirus infection of mucosal epithelial cells. Moreover, GP engagement of the cholesterol transporter Niemann-Pick C1 was demonstrated to be essential for GP-mediated fusion of the viral envelope with a host cell membrane. Finally, mutagenic and structural analyses defined GP domains which interact with these host cell factors. Here, we will review the recent progress in elucidating the molecular interactions underlying filovirus entry and discuss their implications for our understanding of the viral cell tropism.

  8. Host factors and HIV-1 replication: clinical evidence and potential therapeutic approaches

    Directory of Open Access Journals (Sweden)

    Mariana eSanta-Marta

    2013-10-01

    Full Text Available HIV and human defense mechanisms have co-evolved to counteract each other. In the process of infection, HIV takes advantage of cellular machinery and blocks the action of the host restriction factors. A small subset of HIV+ individuals control HIV infection and progression to AIDS in the absence of treatment. These individuals known, as long-term non-progressors (LNTPs exhibit genetic and immunological characteristics that confer upon them an efficient resistance to infection and/or disease progression. The identification of some of these host factors led to the development of therapeutic approaches that attempted to mimic the natural control of HIV infection. Some of these approaches are currently being tested in clinical trials. While there are many genes which carry mutations and polymorphisms associated with non-progression, this review will be specifically focused on HIV host restriction factors (RF including both the main chemokine receptors and chemokines as well as intracellular restriction factors including, APOBEC, TRIM, tetherin and SAMHD1. The understanding of molecular profiles and mechanisms present in LTNPs should provide new insights to control HIV infection and contribute to the development of novel therapies against AIDS.

  9. Factors influencing seed germination in Cerrado grasses

    Directory of Open Access Journals (Sweden)

    Rosana Marta Kolb

    2016-03-01

    Full Text Available Few studies address the ecology of herbs of Cerrado grasslands, which are ecosystems where the long dry season, high temperatures, insolation, fire and invasive grasses greatly influencing germination and the establishment of plants. We assessed germination of 13 species of Poaceae from Cerrado grasslands under nursery conditions or in germination chambers, the latter with i recently collected seeds and seeds after six months storage, ii under constant and alternating temperatures, and iii in the presence and absence of light. Germinability, mean germination time (MGT and required light were quantified to elucidate factors involved in successful germination. Germinability was low for most grasses, probably because of low seed viability. For most species, germinability and MGT were not altered by seed storage. Germination percentages were higher at alternating temperatures and in the presence of light, factors that are more similar to natural environmental situations compared with constant temperature or the absence of light. Our findings indicate that alternating temperatures and light incidence are key factors for germination of species of Poaceae. The maintenance of these environmental factors, which are crucial for the conservation of Cerrado grasslands, depends on appropriate management interventions, such as fire management and the control of biological invasion.

  10. Elucidating biotic factors that influence assembly of fungal endophyte communities

    Science.gov (United States)

    Most plants harbor a diverse assemblage of non-mycorrhizal fungal endophytes. These fungi can directly influence the host plant, and can instigate trophic cascades that affect surrounding communities of herbivores, plants, and animals. Despite this, biotic mechanisms that influence assembly of funga...

  11. Factors Influencing Acceptance Of Contraceptive Methods

    Directory of Open Access Journals (Sweden)

    Anita Gupta

    1997-04-01

    Full Text Available Research Problem: What are the factors influencing acceptance of contraceptive methods.Objective: To study the determinants influencing contra­ceptive acceptance.Study design: Population based cross - sectional study.Setting: Rural area of East DelhiParticipants: Married women in the reproductive age group.Sample:Stratified sampling technique was used to draw the sample.Sample Size: 328 married women of reproductive age group.Study Variables: Socio-economic status, Type of contraceptive, Family size, Male child.Outcome Variables: Acceptance of contraceptivesStatistical Analysis: By proportions.Result: Prevalence of use of contraception at the time of data collection was 40.5%. Tubectomy and vasectomy were most commonly used methods. (59.4%, n - 133. Educational status of the women positively influenced the contraceptive acceptance but income did not. Desire for more children was single most important deterrent for accepting contraception.Recommendations:(i             Traditional method of contraception should be given more attention.(ii            Couplesshould be brought in the contraceptive use net at the early stage of marriage.

  12. Landslide forecasting and factors influencing predictability

    Science.gov (United States)

    Intrieri, Emanuele; Gigli, Giovanni

    2016-11-01

    Forecasting a catastrophic collapse is a key element in landslide risk reduction, but it is also a very difficult task owing to the scientific difficulties in predicting a complex natural event and also to the severe social repercussions caused by a false or missed alarm. A prediction is always affected by a certain error; however, when this error can imply evacuations or other severe consequences a high reliability in the forecast is, at least, desirable. In order to increase the confidence of predictions, a new methodology is presented here. In contrast to traditional approaches, this methodology iteratively applies several forecasting methods based on displacement data and, thanks to an innovative data representation, gives a valuation of the reliability of the prediction. This approach has been employed to back-analyse 15 landslide collapses. By introducing a predictability index, this study also contributes to the understanding of how geology and other factors influence the possibility of forecasting a slope failure. The results showed how kinematics, and all the factors influencing it, such as geomechanics, rainfall and other external agents, are key concerning landslide predictability.

  13. Molecular evidence of host influences on the evolution and spread of human tapeworms.

    Science.gov (United States)

    Michelet, Lorraine; Dauga, Catherine

    2012-08-01

    The taeniasis/cysticercosis complex is included in the list of neglected zoonotic diseases by the World Health Organization due to its significant impact on public health in tropical areas. Cysticercosis is still endemic in many regions of Asia, Africa and Latin America. Long absent in Europe and in other developed countries, cysticercosis has recently re-emerged in the United States and Canada, due to immigration, travel and local transmission. This has encouraged the use of molecular data to understand better the influence of animal and human hosts on the emergence and spread of Taenia species. The increasing number of mitochondrial sequences now available from human tapeworms and recent advances in computational tools has enabled reconstruction of the biogeography and evolutionary history of these organisms. New molecular data have provided insights into the biogeography of T. solium, T. asiatica and T. saginata. A Bayesian statistical framework using variable evolutionary rates from lineage to lineage has allowed an improved timescale analysis of human tapeworms. The dates of divergence obtained were compared to the timing of evolutionary events in the history of their hosts, based on the hypothesis that Taenia spp. and their hosts share a common history. Herein, we review changes in the definitive and secondary hosts and human interactions that underlie the differentiation and evolution of tapeworms. Species diversification of Taenia seems to be closely linked with the evolution of intermediate hosts in response to climatic events during the Pleistocene. Different genotypes of T. solium emerged when European and Asian wild boar Sus spp. populations diverged. Taenia saginata emerged when wild cattle Bos primigenius evolved and when zebu Bos indicus and taurine Bos taurus ancestors separated. Humans through migrations and later with the development of farming and animal husbandry may have had a significant impact on the spread and diversification of tapeworms

  14. Intrinsic and extrinsic factors influencing large African herbivore movements

    NARCIS (Netherlands)

    Venter, J.A.; Prins, H.H.T.; Mashanova, A.; Boer, de W.F.; Slotow, R.

    2015-01-01

    Understanding environmental as well as anthropogenic factors that influence large herbivore ecological patterns and processes should underpin their conservation and management. We assessed the influence of intrinsic, extrinsic environmental and extrinsic anthropogenic factors on movement behaviour o

  15. Intestinal microbiota composition in fishes is influenced by host ecology and environment

    Science.gov (United States)

    WONG, SANDI; RAWLS, JOHN F.

    2016-01-01

    The digestive tracts of vertebrates are colonized by complex assemblages of micro-organisms, collectively called the gut microbiota. Recent studies have revealed important contributions of gut microbiota to vertebrate health and disease, stimulating intense interest in understanding how gut microbial communities are assembled and how they impact host fitness (Sekirov et al. 2010). Although all vertebrates harbour a gut microbiota, current information on microbiota composition and function has been derived primarily from mammals. Comparisons of different mammalian species have revealed intriguing associations between gut microbiota composition and host diet, anatomy and phylogeny (Ley et al. 2008b). However, mammals constitute <10% of all vertebrate species, and it remains unclear whether similar associations exist in more diverse and ancient vertebrate lineages such as fish. In this issue, Sullam et al. (2012) make an important contribution toward identifying factors determining gut microbiota composition in fishes. The authors conducted a detailed meta-analysis of 25 bacterial 16S rRNA gene sequence libraries derived from the intestines of different fish species. To provide a broader context for their analysis, they compared these data sets to a large collection of 16S rRNA gene sequence data sets from diverse free-living and host-associated bacterial communities. Their results suggest that variation in gut microbiota composition in fishes is strongly correlated with species habitat salinity, trophic level and possibly taxonomy. Comparison of data sets from fish intestines and other environments revealed that fish gut microbiota compositions are often similar to those of other animals and contain relatively few free-living environmental bacteria. These results suggest that the gut microbiota composition of fishes is not a simple reflection of the micro-organisms in their local habitat but may result from host-specific selective pressures within the gut (Bevins

  16. Genome-wide RNAi screen identifies broadly-acting host factors that inhibit arbovirus infection.

    Directory of Open Access Journals (Sweden)

    Ari Yasunaga

    2014-02-01

    Full Text Available Vector-borne viruses are an important class of emerging and re-emerging pathogens; thus, an improved understanding of the cellular factors that modulate infection in their respective vertebrate and insect hosts may aid control efforts. In particular, cell-intrinsic antiviral pathways restrict vector-borne viruses including the type I interferon response in vertebrates and the RNA interference (RNAi pathway in insects. However, it is likely that additional cell-intrinsic mechanisms exist to limit these viruses. Since insects rely on innate immune mechanisms to inhibit virus infections, we used Drosophila as a model insect to identify cellular factors that restrict West Nile virus (WNV, a flavivirus with a broad and expanding geographical host range. Our genome-wide RNAi screen identified 50 genes that inhibited WNV infection. Further screening revealed that 17 of these genes were antiviral against additional flaviviruses, and seven of these were antiviral against other vector-borne viruses, expanding our knowledge of invertebrate cell-intrinsic immunity. Investigation of two newly identified factors that restrict diverse viruses, dXPO1 and dRUVBL1, in the Tip60 complex, demonstrated they contributed to antiviral defense at the organismal level in adult flies, in mosquito cells, and in mammalian cells. These data suggest the existence of broadly acting and functionally conserved antiviral genes and pathways that restrict virus infections in evolutionarily divergent hosts.

  17. Examinations of factors influencing toe grip strength.

    Science.gov (United States)

    Soma, Masayuki; Murata, Shin; Kai, Yoshihiro; Nakae, Hideyuki; Satou, Yousuke; Murata, Jun; Miyazaki, Junya

    2016-11-01

    [Purpose] This study examined the relationship between toe grip strength and its associated factors by focusing on factors that were suggested to have a relationship with toe grip strength in previous studies, aiming to clarify the factors influencing the toe grip strength of healthy women. [Subjects and Methods] Twelve healthy young women were selected for this study. Their toe grip strength, angular changes in their ankle joint during toe grip, maximum voluntary contraction activities of the rectus femoris, biceps femoris, and tibialis anterior muscles, and the medial head of the gastrocnemius muscles were measured using electromyography. Their toe curl ability, foot-arch height ratio, and weight were also measured. [Results] Multiple regression analysis demonstrated that the predictors of toe grip strength in the resulting model were foot-arch height ratio and the percentage of integrated electromyography (%IEMG) of the tibialis anterior muscle, as the dependent variables. This reveals that women whose tibialis anterior muscle %IEMG values and foot-arch height ratio are high have greater %IEMG values have greater toe grip strength. [Conclusion] These findings suggest a significant relationship between foot-arch height ratio and toe grip strength, with a reciprocal interaction. These findings further indicate that the risk of falls by the elderly could be decreased if toe grip strength were enhanced, by increasing the height of a low foot-arch with the help of an inserted insole.

  18. Local and regional factors influencing bacterial community assembly.

    Science.gov (United States)

    Lindström, Eva S; Langenheder, Silke

    2012-02-01

    The classical view states that microbial biogeography is not affected by dispersal barriers or historical events, but only influenced by the local contemporary habitat conditions (species sorting). This has been challenged during recent years by studies suggesting that also regional factors such as mass effect, dispersal limitation and neutral assembly are important for the composition of local bacterial communities. Here we summarize results from biogeography studies in different environments, i.e. in marine, freshwater and soil as well in human hosts. Species sorting appears to be the most important mechanism. However, this result might be biased since this is the mechanism that is easiest to measure, detect and interpret. Hence, the importance of regional factors may have been underestimated. Moreover, our survey indicates that different assembly mechanisms might be important for different parts of the total community, differing, for example, between generalists and specialists, and between taxa of different dispersal ability and motility. We conclude that there is a clear need for experimental studies, first, to clearly separate regional and local factors in order to study their relative importance, and second, to test whether there are differences in assembly mechanisms depending on different taxonomic or functional groups.

  19. Host Factors and Biomarkers Associated with Poor Outcomes in Adults with Invasive Pneumococcal Disease.

    Directory of Open Access Journals (Sweden)

    Shigeo Hanada

    Full Text Available Invasive pneumococcal disease (IPD causes considerable morbidity and mortality. We aimed to identify host factors and biomarkers associated with poor outcomes in adult patients with IPD in Japan, which has a rapidly-aging population.In a large-scale surveillance study of 506 Japanese adults with IPD, we investigated the role of host factors, disease severity, biomarkers based on clinical laboratory data, treatment regimens, and bacterial factors on 28-day mortality.Overall mortality was 24.1%, and the mortality rate increased from 10.0% in patients aged ˂50 years to 33.1% in patients aged ≥80 years. Disease severity also increased 28-day mortality, from 12.5% among patients with bacteraemia without sepsis to 35.0% in patients with severe sepsis and 56.9% with septic shock. The death rate within 48 hours after admission was high at 54.9%. Risk factors for mortality identified by multivariate analysis were as follows: white blood cell (WBC count <4000 cells/μL (odds ratio [OR], 6.9; 95% confidence interval [CI], 3.7-12.8, p < .001; age ≥80 years (OR, 6.5; 95% CI, 2.0-21.6, p = .002; serum creatinine ≥2.0 mg/dL (OR, 4.5; 95% CI, 2.5-8.1, p < .001; underlying liver disease (OR, 3.5; 95% CI, 1.6-7.8, p = .002; mechanical ventilation (OR, 3.0; 95% CI, 1.7-5.6, p < .001; and lactate dehydrogenase ≥300 IU/L (OR, 2.4; 95% CI, 1.4-4.0, p = .001. Pneumococcal serotype and drug resistance were not associated with poor outcomes.Host factors, disease severity, and biomarkers, especially WBC counts and serum creatinine, were more important determinants of mortality than bacterial factors.

  20. Prevalence patterns of avian Plasmodium and Haemoproteus parasites and the influence of host relative abundance in southern China.

    Science.gov (United States)

    Zhang, Yanhua; Wu, Yuchun; Zhang, Qiang; Su, Dongdong; Zou, Fasheng

    2014-01-01

    Infectious diseases threaten the health and survival of wildlife populations. Consequently, relationships between host diversity, host abundance, and parasite infection are important aspects of disease ecology and conservation research. Here, we report on the prevalence patterns of avian Plasmodium and Haemoproteus infections and host relative abundance influence based on sampling 728 wild-caught birds representing 124 species at seven geographically widespread sites in southern China. The overall prevalence of two haemoprotozoan parasites, Plasmodium and Haemoproteus, was 29.5%, with 22.0% attributable to Haemoproteus and 7.8% to Plasmodium. Haemoproteus prevalence differed significantly among different avian host families, with the highest prevalence in Nectariniidae, Pycnonotidae and Muscicapidae, whereas Plasmodium prevalence varied significantly among host species. Seventy-nine mitochondrial lineages including 25 from Plasmodium and 54 from Haemoproteus were identified, 80% of which were described here for the first time. The phylogenetic relationships among these parasites indicated stronger host-species specificity for Haemoproteus than Plasmodium. Well-supported host-family (Timaliidae) specific clades were found in both Plasmodium and Haemoproteus. The Haemoproteus tree shows regional subclades, whereas the Plasmodium clades are "scattered" among different geographical regions. Interestingly, there were statistically significant variations in the prevalence of Plasmodium and Haemoproteus among the geographical regions. Furthermore, the prevalence of Plasmodium and Haemoproteus were not significantly correlated with host relative abundance. Further efforts will focus on exploring the relationships between parasite prevalence and sex, age, and immune defense of the host.

  1. Factors influencing career choice in anaesthesiology

    Directory of Open Access Journals (Sweden)

    Asha Tyagi

    2012-01-01

    Full Text Available Background: There is a shortage of anaesthesiologists in India. The factors that prompt medical students to opt for anaesthesiology as their career are not known; neither do we have any mechanism to know a student′s stress-bearing ability before he/she opts for a stressful career like anaesthesiology. We conducted an anonymous, questionnaire-based, cross-sectional survey among 200 post-graduate anaesthesiology students to know various factors that they considered while opting for this speciality, and also evaluated their stress-bearing ability using Antonovsky′s 13-point sense of coherence scale. Methods: Two-hundred anaesthesiology students were asked to complete a questionnaire regarding the factors they considered important while opting for anaesthesiology, also enumerated in order of importance the three most important factors that led to opting this career. Students also answered the questions in Antonovsky′s sense of coherence (SOC scale. Results: Economic security was considered by maximum number of students (67.7%, while intellectual stimulation/challenge offered by anaesthesiology was rated first in order of importance. Influence of doctor−patient relationship was not considered by large number of students. The weak SOC score (55 (25 th percentile was not greatly different than the mean SOC score (60 in the survey. Conclusion: Increasing the exposure of students to anaesthesiology at undergraduate level and building public awareness about the speciality will prompt more students to opt for the speciality, while career counselling with regard to specific needs of a speciality and ability of a student will help in opting the speciality that best suits the student′s personality.

  2. Factors influencing nurses' perceptions of occupational safety.

    Science.gov (United States)

    Samur, Menevse; Intepeler, Seyda Seren

    2017-01-02

    To determine nurses' perceptions of occupational safety and their work environment and examine the sociodemographic traits and job characteristics that influence their occupational safety, we studied a sample of 278 nurses. According to the nurses, the quality of their work environment is average, and occupational safety is insufficient. In the subdimensions of the work environment scale, it was determined that the nurses think "labor force and other resources" are insufficient. In the occupational safety subdimensions "occupational illnesses and complaints" and "administrative support and approaches," they considered occupational safety to be insufficient. "Doctor-nurse-colleague relationships," "exposure to violence," and "work unit" (eg, internal medicine, surgical, intensive care) are the main factors that affect occupational safety. This study determined that hospital administrations should develop and immediately implement plans to ameliorate communication and clinical precautions and to reduce exposure to violence.

  3. Factors Influencing Sulfinatodehalogenation Reactions of Perhalocarbons

    Institute of Scientific and Technical Information of China (English)

    WU,Kai(吴恺); CHEN,Qing-Yun(陈庆云)

    2004-01-01

    The study on the factors influencing sulfinatodehalogenation of perfluorohexyl chloride plus octene-1 by using Na2S2O4/NaHCO3 discovered that among the various solvents tested(e.g.Me2SO,NMP,DMAc,CH3CN,CH3CN/H2O)at different temperatures,Me2SO was found to be the most suitable solvent and the conversion of the chloride was very dependent on the reaction temperature.When Me2SO was used in the reaction of perfluoroalkyl iodides,the reaction temperature could be decreased by 20℃ as compared with that carried out in CH3CN/H2O to reach the comparable yields.

  4. Factors influencing presence in virtual worlds.

    Science.gov (United States)

    Chow, Meyrick C M

    2012-01-01

    Virtual worlds are showing potential as an effective platform for a variety of activities, including learning. The concept of presence (the sensation of "being there" in a mediated environment) has received substantial attention from the virtual reality community, and the effectiveness of virtual worlds has often been linked to the feelings of presence reported by their users. The present study examined the effects of attitude and perceived ease of use on sense of presence in Second Life, which is one of the most known and used virtual worlds. Based on data from a survey of 206 nursing students, hypotheses are empirically tested. Findings suggest that users' attitude toward using Second Life and their perceived ease of use of it have a positive effect on their sense of presence in the virtual environment. This study advances our understanding of factors influencing presence in virtual worlds.

  5. Salidroside exhibits anti-dengue virus activity by upregulating host innate immune factors.

    Science.gov (United States)

    Sharma, Navita; Mishra, K P; Ganju, Lilly

    2016-12-01

    Dengue is an arboviral disease with no effective therapy available. Therefore, there is an urgent need to find a potent antiviral agent against dengue virus (DENV). In the present study, salidroside, a main bioactive compound of Rhodiola rosea, was evaluated for its antiviral potential against DENV serotype-2 infection and its effect on host innate immune factors. Antiviral effects of salidroside were examined in DENV-infected cells by western blotting, flow cytometry and real-time PCR. Its underlying mechanism involved in antiviral action was determined by evaluating expression of host innate immune factors including RIG-I, IRF-3, IRF-7, PKR, P-eIF2α and NF-κB. Salidroside potently inhibited DENV infection by decreasing DENV envelope protein expression more than tenfold. Salidroside exerts its antiviral activity by increasing expression of RNA helicases such as RIG-I, thereby initiating a downstream signaling cascade that induces upregulation of IRF-3 and IRF-7. It prevents viral protein synthesis by increasing the expression of PKR and P-eIF2α while decreasing NF-κB expression. It was also found to induce the expression of IFN-α. In addition, the number of NK cells and CD8(+) T cells were also found to be increased by salidroside treatment in human PBMCs, which are important in limiting DENV replication during early stages of infection. The findings presented here suggest that salidroside exhibits antiviral activity against DENV by inhibiting viral protein synthesis and boosting host immunity by increasing the expression of host innate immune factors and hence could be considered for the development of an effective therapeutic agent against DENV infection.

  6. Butterfly Larval Host Plant use in a Tropical Urban Context: Life History Associations, Herbivory, and Landscape Factors

    Science.gov (United States)

    Tiple, Ashish D.; Khurad, Arun M.; Dennis, Roger L. H.

    2011-01-01

    This study examines butterfly larval host plants, herbivory and related life history attributes within Nagpur City, India. The larval host plants of 120 butterfly species are identified and their host specificity, life form, biotope, abundance and perennation recorded; of the 126 larval host plants, most are trees (49), with fewer herbs (43), shrubs (22), climbers (7) and stem parasites (2). They include 89 wild, 23 cultivated, 11 wild/cultivated and 3 exotic plant species; 78 are perennials, 43 annuals and 5 biannuals. Plants belonging to Poaceae and Fabaceae are most widely used by butterfly larvae. In addition to distinctions in host plant family affiliation, a number of significant differences between butterfly families have been identified in host use patterns: for life forms, biotopes, landforms, perennation, host specificity, egg batch size and ant associations. These differences arising from the development of a butterfly resource database have important implications for conserving butterfly species within the city area. Differences in overall butterfly population sizes within the city relate mainly to the number of host plants used, but other influences, including egg batch size and host specificity are identified. Much of the variation in population size is unaccounted for and points to the need to investigate larval host plant life history and strategies as population size is not simply dependent on host plant abundance. PMID:21864159

  7. Factors influencing consumer dietary health preventative behaviours

    Directory of Open Access Journals (Sweden)

    Ritson Christopher

    2006-09-01

    Full Text Available Abstract Background The deterioration of the health status of the Romanian population during the economic transition from a centrally planned to a free market economy has been linked to lifestyles factors (e.g. diet regarded as a main determinants of the disparity in life expectancy between Eastern and Western Europe. Reforms in the health care system in this transition economy aim to focus on preventive action. The purpose of this study was to identify the factors that impact on the individual decision to engage in Dietary Health Preventive Behaviour (DHPB and investigate their influence in the context of an adapted health cognition model. Methods A population-based study recruited 485 adult respondents using random route sampling and face-to-face administered questionnaires. Results and discussion Respondents' health motivation, beliefs that diet can prevent disease, knowledge about nutrition, level of education attainment and age have a positive influence on DHPB. Perceived barriers to healthy eating have a negative impact on alcohol moderation. The information acquisition behaviour (frequency of reading food labels is negatively predicted by age and positively predicted by health motivation, education, self-reported knowledge about nutrition and household financial status. A significant segment of respondents believe they are not susceptible to the elicited diseases. Health promotion strategies should aim to change the judgments of health risk. Conclusion The adaptation of the Health Belief Model and the Theory of Health Preventive Behaviour represents a valid framework of predicting DHPB. The negative sign of perceived threat of disease on DHPB may suggest that, under an income constraint, consumers tend to trade off long-term health benefits for short-term benefits. This cautions against the use of negative messages in public health campaigns. Raising the awareness of diet-disease relationships, knowledge about nutrition (particularly

  8. Factors influencing women's decision making in hysterectomy.

    Science.gov (United States)

    Janda, Monika; Armfield, Nigel R; Page, Katie; Kerr, Gayle; Kurz, Suzanne; Jackson, Graeme; Currie, Jason; Weaver, Edward; Yazdani, Anusch; Obermair, Andreas

    2017-09-12

    To explore factors influencing how well-informed women felt about hysterectomy, influences on their decision making, and on them receiving a less-invasive alternative to open surgery. Online questionnaire, conducted in 2015-2016, of women who had received a hysterectomy in Australia, in the preceding two years. Questionnaires were completed by 2319/6000 women (39% response). Most women (n=2225; 96%) felt well-informed about hysterectomy. Women were more aware of the open abdominal approach (n=1798; 77%), than of less-invasive vaginal (n=1552; 67%), laparoscopic (n=1540; 66%), laparoscopic-assisted (n=1303; 56%), and robotic approaches (n=289; 12%). Most women (n=1435; 62%) reported their gynaecologist was the most influential information source. Women who received information about hysterectomy from a GP (OR=1.47; 95% CI 1.15-1.90), or from a gynaecologist (OR=1.3; 95% CI 1.06-1.58), were more likely to feel better informed (p<0.01). This study is important because it helps clinicians, researchers and health policy makers to understand why many women still receive an open abdominal approach despite many learned societies recommending to avoid it if possible. Additional information, or education about avoiding open abdominal approach where possible may lead to a greater number of women receiving less-invasive types of hysterectomy in the future. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  9. Annexin A1 influences in breast cancer: Controversies on contributions to tumour, host and immunoediting processes.

    Science.gov (United States)

    Tu, Yan; Johnstone, Cameron N; Stewart, Alastair G

    2017-05-01

    Annexin A1 is a multifunctional protein characterised by its actions in modulating the innate and adaptive immune response. Accumulating evidence of altered annexin A1 expression in many human tumours raises interest in its functional role in cancer biology. In breast cancer, altered annexin A1 expression levels suggest a potential influence on tumorigenic and metastatic processes. However, reports of conflicting results reveal a relationship that is much more complex than first conceptualised. In this review, we explore the diverse actions of annexin A1 on breast tumour cells and various host cell types, including stromal immune and structural cells, particularly in the context of cancer immunoediting. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Transcription factor ATF3 links host adaptive response to breast cancer metastasis

    Science.gov (United States)

    Wolford, Chris C.; McConoughey, Stephen J.; Jalgaonkar, Swati P.; Leon, Marino; Merchant, Anand S.; Dominick, Johnna L.; Yin, Xin; Chang, Yiseok; Zmuda, Erik J.; O’Toole, Sandra A.; Millar, Ewan K.A.; Roller, Stephanie L.; Shapiro, Charles L.; Ostrowski, Michael C.; Sutherland, Robert L.; Hai, Tsonwin

    2013-01-01

    Host response to cancer signals has emerged as a key factor in cancer development; however, the underlying molecular mechanism is not well understood. In this report, we demonstrate that activating transcription factor 3 (ATF3), a hub of the cellular adaptive response network, plays an important role in host cells to enhance breast cancer metastasis. Immunohistochemical analysis of patient tumor samples revealed that expression of ATF3 in stromal mononuclear cells, but not cancer epithelial cells, is correlated with worse clinical outcomes and is an independent predictor for breast cancer death. This finding was corroborated by data from mouse models showing less efficient breast cancer metastasis in Atf3-deficient mice than in WT mice. Further, mice with myeloid cell–selective KO of Atf3 showed fewer lung metastases, indicating that host ATF3 facilitates metastasis, at least in part, by its function in macrophage/myeloid cells. Gene profiling analyses of macrophages from mouse tumors identified an ATF3-regulated gene signature that could distinguish human tumor stroma from distant stroma and could predict clinical outcomes, lending credence to our mouse models. In conclusion, we identified ATF3 as a regulator in myeloid cells that enhances breast cancer metastasis and has predictive value for clinical outcomes. PMID:23921126

  11. Clinical heterogeneity of human neurocysticercosis results from complex interactions among parasite, host and environmental factors.

    Science.gov (United States)

    Fleury, Agnès; Escobar, Alfonso; Fragoso, Gladis; Sciutto, Edda; Larralde, Carlos

    2010-04-01

    Human neurocysticercosis (NC) is endemic in most countries of Latin America, Asia and Africa and is re-emerging in some industrialized nations. Both within and among endemic countries, NC is very variable in its clinical and radiological features, as well as in the intensity of the immuno-inflammatory reactions of the hosts. This review, focusing on the Mexican experience, describes and interprets the heterogeneity of NC as the result of different combinations among factors associated with the parasite, host and environment. The review may serve to foster similar descriptive efforts in other endemic areas of the world in order to facilitate the identification of the distinct factors that participate in the complex pathogenesis and diverse clinical outcomes of NC. In particular, it is necessary to understand the precise physiopathology of the inflammatory reaction associated with NC, as inflammation is one of the characteristics of those NC cases that are clinically more severe and less responsive to current treatments. Devising new medical interventions through the use of molecular regulators of the innate and adaptive immune responses of the host is a largely unexplored approach that could improve the existing forms of treatment. Copyright 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  12. Cancer immunology--analysis of host and tumor factors for personalized medicine.

    Science.gov (United States)

    Ogino, Shuji; Galon, Jérôme; Fuchs, Charles S; Dranoff, Glenn

    2011-08-09

    Immune cells in the tumor microenvironment have an important role in regulating tumor progression. Therefore, stimulating immune reactions to tumors can be an attractive therapeutic and prevention strategy. Cancer cells and host cells constantly interact with each other in the tumor microenvironment; thus, cancer immunology is an interdisciplinary area where integrated analysis of both host and tumor factors is needed. Cancer represents a heterogeneous group of diseases with different genetic and epigenetic alterations; therefore, molecular classification of cancer (for example lung, prostate and breast cancers) is an important component in clinical decision making. However, most studies on antitumor immunity and clinical outcome lack analysis of tumor molecular biomarkers. In this Review, we discuss colorectal cancer as a prototypical example of cancer. Common molecular classifiers of colon cancer include KRAS, BRAF and PIK3CA mutations, microsatellite instability, LINE-1 methylation, and CpG island methylator phenotype. Since tumor molecular features and immune reactions are inter-related, a comprehensive assessment of these factors is critical. Examining the effects of tumor-host interactions on clinical outcome and prognosis represents an evolving interdisciplinary field of molecular pathological epidemiology. Pathological immunity evaluation may provide information on prognosis and help identify patients who are more likely to benefit from immunotherapy.

  13. Factors Influencing Students’ Perceptions of Online Teamwork

    Directory of Open Access Journals (Sweden)

    Irina Falls

    2014-02-01

    Full Text Available The evolution of online teaching in higher education demands a change in the types of pedagogies used in those courses. An example of one of these important pedagogies includes online teamwork. Teamwork in this context is one in which the majority of the individual’s grade is dependent on the positive or negative group experiences. This study utilized the theoretical framework of social motivation and cohesion to identify the factors shaping students’ perceptions of teamwork in online college courses. In these courses, the pedagogical approach known as the Five Pillars of effective collaborative work was applied. An Online Teamwork Learning Survey was developed based on these principles and completed by 62 undergraduate students enrolled in semester-long online courses required in their early childhood education program of study. Using a comparison between pre–postsurveys and regression analysis, the results showed that although the students’ perceptions of teamwork did not significantly change, the factors influencing their responses during the posttest doubled in number. The results showed that through carefully designed virtual teamwork activities, students learned that essential team characteristics such as promotive interaction, individual accountability, and positive interdependence are an integral part of effective collaboration and strong predictors of teamwork perception.

  14. Helicobacter pylori virulence genes and host genetic polymorphisms as risk factors for peptic ulcer disease.

    Science.gov (United States)

    Miftahussurur, Muhammad; Yamaoka, Yoshio

    2015-01-01

    Helicobacter pylori infection plays an important role in the pathogenesis of peptic ulcer disease (PUD). Several factors have been proposed as possible H. pylori virulence determinants; for example, bacterial adhesins and gastric inflammation factors are associated with an increased risk of PUD. However, differences in bacterial virulence factors alone cannot explain the opposite ends of the PUD disease spectrum, that is duodenal and gastric ulcers; presumably, both bacterial and host factors contribute to the differential response. Carriers of the high-producer alleles of the pro-inflammatory cytokines IL-1B, IL-6, IL-8, IL-10, and TNF-α who also carry low-producer allele of anti-inflammatory cytokines have severe gastric mucosal inflammation, whereas carriers of the alternative alleles have mild inflammation. Recent reports have suggested that the PSCA and CYP2C19 ultra-rapid metabolizer genotypes are also associated with PUD.

  15. Role of Host Genetic Factors in the Outcome of Hepatitis C Virus Infection

    Directory of Open Access Journals (Sweden)

    Hubert E. Blum

    2009-08-01

    Full Text Available The natural history of hepatitis C virus (HCV infection is determined by a complex interplay between host genetic, immunological and viral factors. This review highlights genes involved in innate and adaptive immune responses associated with different outcomes of HCV infection. For example, an association of HCV clearance with certain HLA alleles has been demonstrated. The mechanisms responsible for these associations have been linked to specific T cell responses for some particular alleles (e.g., HLA-B27. Genetic associations involved in T cell regulation and function further underline the role of the adaptive immune response in the natural history of HCV infection. In addition, some genes involved in innate NK cell responses demonstrate the complex interplay between components of the immune system necessary for a successful host response to HCV infection.

  16. Preoperative factors influencing success in pterygium surgery

    Directory of Open Access Journals (Sweden)

    Torres-Gimeno Ana

    2012-08-01

    Full Text Available Abstract Background To identify preoperative, perioperative and postoperative risk factors that influence the success of pterygium surgery. Methods This is a prospective study of thirty-six patients with primary or recurrent pterygia. A detailed anamnesis and an ophthalmological examination were performed looking for the following factors: age, race, latitude and altitude of the main place of residence, hours of exposure to the sun, use of protective measures against UV-radiation, classification of pterygium, width of the pterygium at limbus, surgical technique (conjunctival autograft plus suturing versus tissue glue, graft alterations (misapposition, granuloma, haemorrhage, oedema, retraction or necrosis, and postoperative symptoms (foreign-body sensation, pain. The examinations were performed 2 and 7 days and 2, 6 and 12 months after surgery. In addition, recurrence was defined as any growth of conjunctiva into the cornea. Results A logistic regression and a survival analysis have been used to perform data analysis. A total number of 36 patients completed a one year follow-up. A total of 13 patients were born and lived in Spain, and 26 came from other countries, mostly Latin America. A total number of 8 males (no women presented a recurrence, mainly between 2 and 6 months. The hours of sun exposure through their life was independently related to surgical success. Pterygia of less than 5 mm of base width showed a weak positive correlation with recurrence. None of the other factors considered were significantly related to recurrence. Conclusions Male gender and high sun exposure are strongly and independently related to surgical success after the removal of pterygia.

  17. Factors affecting patterns of Amblyomma triste (Acari: Ixodidae) parasitism in a rodent host.

    Science.gov (United States)

    Colombo, Valeria C; Nava, Santiago; Antoniazzi, Leandro R; Monje, Lucas D; Racca, Andrea L; Guglielmone, Alberto A; Beldomenico, Pablo M

    2015-07-30

    Here we offer a multivariable analysis that explores associations of different factors (i.e., environmental, host parameters, presence of other ectoparasites) with the interaction of Amblyomma triste immature stages and one of its main hosts in Argentina, the rodent Akodon azarae. Monthly and for two years, we captured and sampled rodents at 16 points located at 4 different sites in the Parana River Delta region. The analyses were conducted with Generalized Linear Mixed Models with a negative binomial response (counts of larvae or nymphs). The independent variables assessed were: (a) environmental: trapping year, season, presence of cattle; type of vegetation (natural grassland or implanted forest); rodent abundance; (b) host parameters: body length; sex; body condition; blood cell counts; natural antibody titres; and (c) co-infestation with other ectoparasites: other stage of A. triste; Ixodes loricatus; lice; mites; and fleas. Two-way interaction terms deemed a priori as relevant were also included in the analysis. Larvae were affected by all environmental variables assessed and by the presence of other ectoparasites (lice, fleas and other tick species). Host factors significantly associated with larval count were sex and levels of natural antibodies. Nymphs were associated with season, presence of cattle, body condition, body length and with burdens of I. loricatus. In most cases, the direction and magnitude of the associations were context-dependent (many interaction terms were significant). The findings of greater significance and implications of our study are two. Firstly, as burdens of A. triste larvae and nymphs were greater where cattle were present, and larval tick burdens were higher in implanted forests, silvopastoral practices developing in the region may affect the population dynamics of A. triste, and consequently the eco-epidemiology of Rickettsia parkeri. Secondly, strong associations and numerous interactions with other ectoparasites suggest that

  18. Quantitative factors proposed to influence the prevalence of canine tick-borne disease agents in the United States

    OpenAIRE

    Stich, Roger W.; Blagburn, Byron L; Bowman, Dwight D.; Carpenter, Christopher; Cortinas, M. Roberto; Ewing, Sidney A; Foley, Desmond; Foley, Janet E.; Gaff, Holly; Hickling, Graham J.; Lash, R. Ryan; Little, Susan E; Lund, Catherine; Lund, Robert; Mather, Thomas N.

    2014-01-01

    The Companion Animal Parasite Council hosted a meeting to identify quantifiable factors that can influence the prevalence of tick-borne disease agents among dogs in North America. This report summarizes the approach used and the factors identified for further analysis with mathematical models of canine exposure to tick-borne pathogens.

  19. Remarks on the physical factor influencing the individual language learners

    Institute of Scientific and Technical Information of China (English)

    刘晨君

    2015-01-01

    individual language learner as a subject of learning can be influenced by many factors such as physical factor,cognitive factor,and affective factor.All of which play an important role in language learning.These three factors are worthy of our research and physical factor will be discussed in this essay.

  20. Differences in host breed and diet influence colonization by Campylobacter jejuni and induction of local immune responses in chicken.

    Science.gov (United States)

    Han, Zifeng; Willer, Thomas; Pielsticker, Colin; Gerzova, Lenka; Rychlik, Ivan; Rautenschlein, Silke

    2016-01-01

    Chickens are regarded as the main reservoir for human campylobacteriosis. Little is known about the interaction between Campylobacter jejuni (C. jejuni) and chickens. This interaction may be influenced by the stage of maturation of the immune system, developing gut microbiota composition and other factors including breed and diet. Our aim was to investigate the impact of breed, and diet on C. jejuni colonization and host immune responses in chickens. Birds were inoculated with 10(4) colony forming units (CFU) of C. jejuni or diluent at one (Exp. 1) or 22 (Exp. 2) days post hatch. We compared local immune cell subpopulations, cytokine expression levels, and gut microbiota composition between broiler-type (BT) and layer-type (LT) birds fed with either commercial broiler feed (bf) or layer feed (lf). Lower colonization rates were observed in the older age group independent of breed and diet. Independent of breed, birds fed with bf showed higher CFU of C. jejuni compared to lf-fed groups. Campylobacter jejuni-inoculation had a significant effect on lymphocyte numbers and cytokine expression levels in BT birds independent of feeding strategy (p breeds. Diet and breed influenced C. jejuni colonization, immune responses and microbiota composition to a different extent comparing between LT and BT birds. The mechanisms behind these differences have to be elucidated further. Our results suggest that selection for more resistant breeds in combination with adapted feeding strategies may help to reduce Campylobacter colonization levels in commercial poultry in the future.

  1. The Host Microenvironment Influences Prostate Cancer Invasion, Systemic Spread, Bone Colonization, and Osteoblastic Metastasis

    Science.gov (United States)

    Ganguly, Sourik S.; Li, Xiaohong; Miranti, Cindy K.

    2014-01-01

    Prostate cancer (PCa) is the second leading cause of cancer death in men worldwide. Most PCa deaths are due to osteoblastic bone metastases. What triggers PCa metastasis to the bone and what causes osteoblastic lesions remain unanswered. A major contributor to PCa metastasis is the host microenvironment. Here, we address how the primary tumor microenvironment influences PCa metastasis via integrins, extracellular proteases, and transient epithelia-mesenchymal transition (EMT) to promote PCa progression, invasion, and metastasis. We discuss how the bone-microenvironment influences metastasis; where chemotactic cytokines favor bone homing, adhesion molecules promote colonization, and bone-derived signals induce osteoblastic lesions. Animal models that fully recapitulate human PCa progression from primary tumor to bone metastasis are needed to understand the PCa pathophysiology that leads to bone metastasis. Better delineation of the specific processes involved in PCa bone metastasize is needed to prevent or treat metastatic PCa. Therapeutic regimens that focus on the tumor microenvironment could add to the PCa pharmacopeia. PMID:25566502

  2. Human host defense peptide LL-37 stimulates virulence factor production and adaptive resistance in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Nikola Strempel

    Full Text Available A multitude of different virulence factors as well as the ability to rapidly adapt to adverse environmental conditions are important features for the high pathogenicity of Pseudomonas aeruginosa. Both virulence and adaptive resistance are tightly controlled by a complex regulatory network and respond to external stimuli, such as host signals or antibiotic stress, in a highly specific manner. Here, we demonstrate that physiological concentrations of the human host defense peptide LL-37 promote virulence factor production as well as an adaptive resistance against fluoroquinolone and aminoglycoside antibiotics in P. aeruginosa PAO1. Microarray analyses of P. aeruginosa cells exposed to LL-37 revealed an upregulation of gene clusters involved in the production of quorum sensing molecules and secreted virulence factors (PQS, phenazine, hydrogen cyanide (HCN, elastase and rhamnolipids and in lipopolysaccharide (LPS modification as well as an induction of genes encoding multidrug efflux pumps MexCD-OprJ and MexGHI-OpmD. Accordingly, we detected significantly elevated levels of toxic metabolites and proteases in bacterial supernatants after LL-37 treatment. Pre-incubation of bacteria with LL-37 for 2 h led to a decreased susceptibility towards gentamicin and ciprofloxacin. Quantitative Realtime PCR results using a PAO1-pqsE mutant strain present evidence that the quinolone response protein and virulence regulator PqsE may be implicated in the regulation of the observed phenotype in response to LL-37. Further experiments with synthetic cationic antimicrobial peptides IDR-1018, 1037 and HHC-36 showed no induction of pqsE expression, suggesting a new role of PqsE as highly specific host stress sensor.

  3. Targeting host factors: A novel rationale for the management of hepatitis C virus

    Institute of Scientific and Technical Information of China (English)

    Mahmoud Aboelneen Khattab

    2009-01-01

    Hepatitis C is recognized as a major threat to global public health. The current treatment of patients with chronic hepatitis C is the addition of ribavirin to interferon-based therapy which has limited efficacy, poor tolerability, and significant expense. New treatment options that are more potent and less toxic are much needed. Moreover, more effective treatment is an urgent priority for those who relapse or do not respond to current regimens. A major obstacle in combating hepatitis C virus (HCV) infection is that the fidelity of the viral replication machinery is notoriously low, thus enabling the virus to quickly develop mutations that resist compounds targeting viral enzymes. Therefore, an approach targeting the host cofactors, which are indispensable for the propagation of viruses, may be an ideal target for the development of antiviral agents because they have a lower rate of mutation than that of the viral genome, as long as they have no side effects to patients. Drugs targeting, for example, receptors of viral entry, host metabolism or nuclear receptors, which are factors required to complete the HCV life cycle, may be more effective in combating the viral infection. Targeting host cofactors of the HCV life cycle is an attractive concept because it imposes a higher genetic barrier for resistance than direct antiviral compounds. However the principle drawback of this strategy is the greater potential for cellular toxicity.

  4. Hydrolysis kinetics of atrazine and influence factors

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The hydrolysis kinetics of atrazine in distilled water and leaching water from soil, and their influence factors were studied by incubation at 35℃ and HPLC analysis method in this paper. The kinetic process of atrazine hydrolysis can be described by the first-order reaction law. The results showed that the hydrolysis rate constants k in leaching water and distilled water were 1.606x10-3/d and 1.055x10-3/d, respectively; the half-life of atrazine hydrolysis in distilled water at pH 3, pH 4.5 and pH 8 were 373 days, 522 days and 657 days respectively. The results also showed that the proton in reaction solution can catalyze the atrazine hydrolysis; humic acid and NH4+ etc. substances in aqueous solution can facilitate atrazine hydrolysis; rate constants of atrazine hydrolysis with humic acid and NH4NO3 were 2.431x10-3/d and 1.498x10-3/d respectively which were 2.3 and 1.42 times of control(1.055x10-3/d); anion NO3- can inhibit catalysis of humic acid to atrazine hydrolysis.

  5. Factors influencing competitive anxiety in Brazilian athletes

    Directory of Open Access Journals (Sweden)

    Marcos Gimenes Fernandes

    2013-09-01

    Full Text Available The study of factors influencing competitive anxiety, according to a multidimensional perspective and supported by valid instruments, is scarce among Brazilian athletes of different sports. The present study aims to: i investigate the theoretical relationship between the different dimensions of the multidimensional theory of anxiety (i.e., cognitive anxiety, somatic anxiety and self-confidence; and ii investigate the effects of gender, type of sport (individual or collective and competitive experience levels on cognitive anxiety, somatic anxiety and self-confidence. A total of 303 athletes (233 males and 70 females, from different sports, aged between 18 and 40 years (M =24.22, SD = 5.07 completed a shortened version of CSAI-2 (i.e., CSAI-2R, about one hour before the start of competitions. Results revealed significant correlations between cognitive anxiety, somatic anxiety and self-confidence dimensions, in accordance with the assumptions of the multidimensional theory. Additionally, comparative analyses indicated that female athletes and athletes from collective sports showed higher levels of cognitive anxiety, while male athletes and athletes with high competitive experience reported higher levels of self-confidence. These results were discussed taking into account the theoretical and practical implications of these findings for planning interventions of sport psychology in Brazil with athletes of different contexts.

  6. Factors That Influence Primary Cilium Length

    Directory of Open Access Journals (Sweden)

    Miyoshi,Ko

    2011-10-01

    Full Text Available Almost all mammalian cells carry one primary cilium that functions as a biosensor for chemical and mechanical stimuli. Genetic damages that compromise cilia formation or function cause a spectrum of disorders referred to as ciliapathies. Recent studies have demonstrated that some pharmacological agents and extracellular environmental changes can alter primary cilium length. Renal injury is a well-known example of an environmental insult that triggers cilia length modification. Lithium treatment causes primary cilia to extend in several cell types including neuronal cells;this phenomenon is likely independent of glycogen synthase kinase-3β inhibition. In renal epithelial cell lines, deflection of the primary cilia by fluid shear shortens them by reducing the intracellular cyclic AMP level, leading to a subsequent decrease in mechanosensitivity to fluid shear. Primary cilium length is also influenced by the dynamics of actin filaments and microtubules through the levels of soluble tubulin in the cytosol available for primary cilia extension. Thus, mammalian cells can adapt to the extracellular environment by modulating the primary cilium length, and this feedback system utilizing primary cilia might exist throughout the mammalian body. Further investigation is required concerning the precise molecular mechanisms underlying the control of primary cilium length in response to environmental factors.

  7. The influence of Hymenolepis diminuta on the survival and fecundity of the intermediate host, Tribolium confusum.

    Science.gov (United States)

    Keymer, A E

    1980-10-01

    An experimental study of the effects of parasitism by H. diminuta on the intermediate host, Tribolium confusum, is described. No density-dependent constraints on parasite establishment within individual hosts are evident, although a reduction in cysticercoid size at high parasite burdens is demonstrated. The relationship between parasite burden, host mortality and host fecundity is investigated. Host mortality is linearly related to parasite burden, whereas the relationship between parasite burden and host fecundity is non-linear. There is no difference in viability between eggs from infected and uninfected females. The generative causes of these effects are not investigated experimentally, although it is postulated that survival is related to the degree of damage to the midgut wall caused by parasite penetration, and fecundity to the biomass of parasites harboured by the host. The significance of these effects is discussed in relation to the overall dynamics of the host-parasite association.

  8. Yersinia virulence factors - a sophisticated arsenal for combating host defences [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Steve Atkinson

    2016-06-01

    Full Text Available The human pathogens Yersinia pseudotuberculosis and Yersinia enterocolitica cause enterocolitis, while Yersinia pestis is responsible for pneumonic, bubonic, and septicaemic plague. All three share an infection strategy that relies on a virulence factor arsenal to enable them to enter, adhere to, and colonise the host while evading host defences to avoid untimely clearance. Their arsenal includes a number of adhesins that allow the invading pathogens to establish a foothold in the host and to adhere to specific tissues later during infection. When the host innate immune system has been activated, all three pathogens produce a structure analogous to a hypodermic needle. In conjunction with the translocon, which forms a pore in the host membrane, the channel that is formed enables the transfer of six ‘effector’ proteins into the host cell cytoplasm. These proteins mimic host cell proteins but are more efficient than their native counterparts at modifying the host cell cytoskeleton, triggering the host cell suicide response. Such a sophisticated arsenal ensures that yersiniae maintain the upper hand despite the best efforts of the host to counteract the infecting pathogen.

  9. Urban water consumption and its influencing factors in China

    NARCIS (Netherlands)

    Fan, Liangxin; Gai, Lingtong; Tong, Yan; Li, Ruihua

    2017-01-01

    Factors that affect water consumption should be identified to develop effective public policies. However, factors influencing domestic water consumption in cities in China, particularly on a national scale, are unclear. In this study, urban water consumption and its influencing factors in 286

  10. What Factors Influence a Teacher's Commitment to Student Learning?

    Science.gov (United States)

    Dannetta, Vincent

    2002-01-01

    Study of the personal, organizational, student-related factors influencing teacher commitment to student learning. Finds, for example, that among personal factors intrinsic rewards are more important than extrinsic rewards, that among organization factors collegiality is an important influence on commitment to student learning, and that among…

  11. Degree of host susceptibility in the initial disease outbreak influences subsequent epidemic spread.

    Science.gov (United States)

    Severns, Paul M; Estep, Laura K; Sackett, Kathryn E; Mundt, Christopher C

    2014-12-01

    Disease epidemics typically begin as an outbreak of a relatively small, spatially explicit population of infected individuals (focus), in which disease prevalence increases and rapidly spreads into the uninfected, at-risk population. Studies of epidemic spread typically address factors influencing disease spread through the at-risk population, but the initial outbreak may strongly influence spread of the subsequent epidemic.We initiated wheat stripe rust Puccinia striiformis f. sp. tritici epidemics to assess the influence of the focus on final disease prevalence when the degree of disease susceptibility differed between the at-risk and focus populations.When the focus/at-risk plantings consisted of partially genetic resistant and susceptible cultivars, final disease prevalence was statistically indistinguishable from epidemics produced by the focus cultivar in monoculture. In these experimental epidemics, disease prevalence was not influenced by the transition into an at-risk population that differed in disease susceptibility. Instead, the focus appeared to exert a dominant influence on the subsequent epidemic.Final disease prevalence was not consistently attributable to either the focus or the at-risk population when focus/at-risk populations were planted in a factorial set-up with a mixture (~28% susceptible and 72% resistant) and susceptible individuals. In these experimental epidemics, spatial heterogeneity in disease susceptibility within the at-risk population appeared to counter the dominant influence of the focus.Cessation of spore production from the focus (through fungicide/glyphosate application) after 1.3 generations of stripe rust spread did not reduce final disease prevalence, indicating that the focus influence on disease spread is established early in the epidemic.Synthesis and applications. Our experiments indicated that outbreak conditions can be highly influential on epidemic spread, even when disease resistance in the at-risk population is

  12. A Comparison of Factors that Influence the Lyophilization Process

    OpenAIRE

    Dumitru Mnerie; Gabriela-victoria Anghel; Alin Vasile Mnerie; Constantin Cheveresan

    2007-01-01

    The lyophilization (or freeze drying) process for agro-foods products depends on a series of technological factors that are in an inter-dependence with the process performance. This paper presents an expert method and its application. This method characterizes the influence factors of the lyophilization process, after the importance level of some factors in correlation with other factors, is defined. Only the most important factors were considered; influence considerations were made in relati...

  13. Factors Influencing Food Choice in the Elderly Mauritian Population ...

    African Journals Online (AJOL)

    Factors Influencing Food Choice in the Elderly Mauritian Population. ... in influencing food choices and thus food intake of the elderly people in Mauritius. A cross-sectional nutritional survey was carried out in different regions around the island ...

  14. Factors of Influence on Receivables and Payables and Their Classification

    OpenAIRE

    Kuzmin Oleg Ye.; Volovich Yelena B.

    2013-01-01

    The approaches to classification factors of receivables and payables are analyzed in the article. In order to develop effective methods of receivables and payables management, its factors of influence are proposed to divide into three groups - macro factors, the factors of enterprises immediate environment and micro factors.

  15. Influence of different host associations on glutamine synthetase activity and ammonium transporter in Santalumalbum L.

    Science.gov (United States)

    Deepa, P; Yusuf, A

    2016-07-01

    The present study was aimed at understanding the role of different hosts in ammonium transporter1;2 expressions and glutamine synthetase(GS) activity and their effects on the growth parameters in the sandal. Sandal plant associated with leguminous host expressed better growth parameters. GS activity of leguminous hosts alone and in host associated sandals was analyzed using GS transferase assay. Highest GS activity was expressed in Mimosa pudica-sandal association compared to other leguminous and non-leguminous host associations. The association of N2 fixing host with sandal enhanced C and N levels in order to maintain the C/N value. The role of ammonium transporters in N nutrition of sandal-host association was elucidated by cloning AMT1;2 from the leaves, haustoria and roots of host associated sandal and quantifying the relative expression by the [Formula: see text] method. SaAMT1;2 was strongly up-regulated in leaves, roots and haustoria of leguminous host associated sandal compared to non-leguminous host associations. The relative increase in SaAMT1;2 expressions and up-regulated GS activity positively affected the growth parameters in sandal when associated with leguminous hosts.

  16. Lipoarabinomannan in urine during tuberculosis treatment: association with host and pathogen factors and mycobacteriuria

    Directory of Open Access Journals (Sweden)

    Wood Robin

    2012-02-01

    Full Text Available Abstract Background Detection of lipoarabinomannan (LAM, a Mycobacterium tuberculosis (Mtb cell wall antigen, is a potentially attractive diagnostic. However, the LAM-ELISA assay has demonstrated variable sensitivity in diagnosing TB in diverse clinical populations. We therefore explored pathogen and host factors potentially impacting LAM detection. Methods LAM-ELISA assay testing, sputum smear and culture status, HIV status, CD4 cell count, proteinuria and TB outcomes were prospectively determined in adults diagnosed with TB and commencing TB treatment at a South African township TB clinic. Sputum TB isolates were characterised by IS61110-based restriction fragment length polymorphism (RFLP and urines were tested for mycobacteriuria by Xpert® MTB/RIF assay. Results 32/199 (16.1% of patients tested LAM-ELISA positive. Median optical density and proportion testing LAM positive remained unchanged during 2 weeks of treatment and then declined over 24 weeks. LAM was associated with positive sputum smear and culture status, HIV infection and low CD4 cell counts but not proteinuria, RFLP strain or TB treatment outcome. The sensitivity of LAM for TB in HIV-infected patients with CD4 counts of ≥ 200, 100-199, 50-99, and Conclusions Urinary LAM was related to host immune factors, was unrelated to Mtb strain and declined steadily after an initial 2 weeks of TB treatment. The strong association of urine LAM with mycobacteriuria is a new finding, indicating frequent TB involvement of the renal tract in advanced HIV infection.

  17. Lipoarabinomannan in urine during tuberculosis treatment: association with host and pathogen factors and mycobacteriuria.

    Science.gov (United States)

    Wood, Robin; Racow, Kimberly; Bekker, Linda-Gail; Middelkoop, Keren; Vogt, Monica; Kreiswirth, Barry N; Lawn, Stephen D

    2012-02-27

    Detection of lipoarabinomannan (LAM), a Mycobacterium tuberculosis (Mtb) cell wall antigen, is a potentially attractive diagnostic. However, the LAM-ELISA assay has demonstrated variable sensitivity in diagnosing TB in diverse clinical populations. We therefore explored pathogen and host factors potentially impacting LAM detection. LAM-ELISA assay testing, sputum smear and culture status, HIV status, CD4 cell count, proteinuria and TB outcomes were prospectively determined in adults diagnosed with TB and commencing TB treatment at a South African township TB clinic. Sputum TB isolates were characterised by IS61110-based restriction fragment length polymorphism (RFLP) and urines were tested for mycobacteriuria by Xpert® MTB/RIF assay. 32/199 (16.1%) of patients tested LAM-ELISA positive. Median optical density and proportion testing LAM positive remained unchanged during 2 weeks of treatment and then declined over 24 weeks. LAM was associated with positive sputum smear and culture status, HIV infection and low CD4 cell counts but not proteinuria, RFLP strain or TB treatment outcome. The sensitivity of LAM for TB in HIV-infected patients with CD4 counts of ≥ 200, 100-199, 50-99, and Urinary LAM was related to host immune factors, was unrelated to Mtb strain and declined steadily after an initial 2 weeks of TB treatment. The strong association of urine LAM with mycobacteriuria is a new finding, indicating frequent TB involvement of the renal tract in advanced HIV infection.

  18. Host and viral factors contributing to CD8+ T cell failure in hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    Christoph Neumann-Haefelin; Hans Christian Spangenberg; Hubert E Blum; Robert Thimme

    2007-01-01

    Virus-specific CD8+ T cells are thought to be the major anti-viral effector cells in hepatitis C virus (HCV)infection. Indeed, viral clearance is associated with vigorous CD8+ T cell responses targeting multiple epitopes. In the chronic phase of infection, HCV-specific CD8+ T cell responses are usually weak, narrowly focused and display often functional defects regarding cytotoxicity, cytokine production, and proliferative capacity. In the last few years, different mechanisms which might contribute to the failure of HCV-specific CD8+ T cells in chronic infection have been identified,including insufficient CD4+ help, deficient CD8+ T cell differentiation, viral escape mutations, suppression by viral factors, inhibitory cytokines, inhibitory ligands, and regulatory T cells. In addition, host genetic factors such as the host's human leukocyte antigen (HLA) background may play an important role in the efficiency of the HCVspecific CD8+ T cell response and thus outcome of infection. The growing understanding of the mechanisms contributing to T cell failure and persistence of HCV infection will contribute to the development of successful immunotherapeutical and -prophylactical strategies.

  19. The interplay of host genetic factors and Epstein-Barr virus in the development of nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Maria Li Lung; Arthur Kwok Leung Cheung; Josephine Mun Yee Ko; Hong Lok Lung; Yue Cheng; Wei Dai

    2014-01-01

    The interplay between host cell genetics and Epstein-Barr virus (EBV) infection contributes to the development of nasopharyngeal carcinoma (NPC). Understanding the host genetic and epigenetic alterations and the influence of EBV on cell signaling and host gene regulation will aid in understanding the molecular pathogenesis of NPC and provide useful biomarkers and targets for diagnosis and therapy. In this review, we provide an update of the oncogenes and tumor suppressor genes associated with NPC, as wel as genes associated with NPC risk including those involved in carcinogen detoxification and DNA repair. We also describe the importance of host genetics that govern the human leukocyte antigen (HLA) complex and immune responses, and we describe the impact of EBV infection on host cell signaling changes and epigenetic regulation of gene expression. High-power genomic sequencing approaches are needed to elucidate the genetic basis for inherited susceptibility to NPC and to identify the genes and pathways driving its molecular pathogenesis.

  20. Energy transfer between a nanosystem and its host fluid: A multiscale factorization approach

    Energy Technology Data Exchange (ETDEWEB)

    Sereda, Yuriy V.; Espinosa-Duran, John M.; Ortoleva, Peter J., E-mail: ortoleva@indiana.edu [Center for Cell and Virus Theory, Department of Chemistry, Indiana University, 800 E. Kirkwood Ave, Bloomington, Indiana 47405 (United States)

    2014-02-21

    Energy transfer between a macromolecule or supramolecular assembly and a host medium is considered from the perspective of Newton's equations and Lie-Trotter factorization. The development starts by demonstrating that the energy of the molecule evolves slowly relative to the time scale of atomic collisions-vibrations. The energy is envisioned to be a coarse-grained variable that coevolves with the rapidly fluctuating atomistic degrees of freedom. Lie-Trotter factorization is shown to be a natural framework for expressing this coevolution. A mathematical formalism and workflow for efficient multiscale simulation of energy transfer is presented. Lactoferrin and human papilloma virus capsid-like structure are used for validation.

  1. Host factors are dominant in the development of post-liver transplant non-alcoholic steatohepatitis

    Institute of Scientific and Technical Information of China (English)

    Salih; Boga; Armando; Salim; Munoz-Abraham; Manuel; I; Rodriguez-Davalos; Sukru; H; Emre; Dhanpat; Jain; Michael; L; Schilsky

    2016-01-01

    Non-alcoholic fatty liver disease(NAFLD) is a recognized problem in patients after orthotopic liver transplantation and may lead to recurrent graft injury. As the increased demand for liver allografts fail to match the available supply of donor organs, split liver transplantation(SLT) has emerged as an important technique to increase the supply of liver grafts. SLT allows two transplants to occur from one donor organ, and provides a unique model for observing the pathogenesis of NAFLD with respect to the role of recipient environmental and genetic factors. Here we report on two recipients of a SLT from the same deceased donor where only one developed non-alcoholic steatohepatitis(NASH), suggesting that host factors are critical for the development of NASH.

  2. Influence of presence and spatial arrangement of belowground insects on host-plant selection of aboveground insects: a field study

    NARCIS (Netherlands)

    Soler, R.; Schaper, S.V.; Bezemer, T.M.; Cortesero, A.M.; Hoffmeister, T.S.; Putten, van der W.H.; Vet, L.E.M.; Harvey, J.A.

    2009-01-01

    1. Several studies have shown that above- and belowground insects can interact by influencing each others growth, development, and survival when they feed on the same host-plant. In natural systems, however, insects can make choices on which plants to oviposit and feed. A field experiment was carrie

  3. Graft-versus-host disease after orthotopic liver transplantation: multivariate analysis of risk factors.

    Science.gov (United States)

    Elfeki, Mohamed A; Pungpapong, Surakit; Genco, Petrina V; Nakhleh, Raouf E; Nguyen, Justin H; Harnois, Denise M

    2015-12-01

    Graft-versus-host disease (GVHD) is a rare, fatal complication following orthotopic liver transplantation (OLT). To date, several risk factors have been proposed, but reports on these factors have been inconclusive. This is a retrospective, case-control study of prospectively collected data from 2775 OLTs performed at our institution. Eight cases of GVHD after OLT were diagnosed on the basis of the patient's clinical characteristics, and the findings were confirmed with skin and colonic biopsies. Each case was matched to three controls based on the diagnosis of liver disease, recipient's age, and blood group. Univariate and multivariate analyses were performed to identify risk factors associated with the development of GVHD after OLT. The univariate and multivariate analyses identified two main risk factors associated with development of GVHD in OLT recipients, a difference between recipient and donor age of >20 yr, and any human leukocyte antigen class I matches. Taking these two risk factors into consideration while matching prospective donors and recipients may reduce further incidence of GVHD in OLT patients. However, further studies are recommended to validate these findings. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Influence of Host Genetics and Environment on Nasal Carriage of Staphylococcus aureus in Danish Middle-Aged and Elderly Twins

    DEFF Research Database (Denmark)

    Andersen, Paal Skytt; Pedersen, Jacob Krabbe; Fode, Peder;

    2012-01-01

    Background. Nasal carriage is a major risk factor for Staphylococcus aureus infection. Approximately, one-quarter of adults carry S. aureus. However, the role of host genetics on S. aureus nasal carriage is unknown. Methods. Nasal swabs were obtained from a national cohort of middle-aged and elde......Background. Nasal carriage is a major risk factor for Staphylococcus aureus infection. Approximately, one-quarter of adults carry S. aureus. However, the role of host genetics on S. aureus nasal carriage is unknown. Methods. Nasal swabs were obtained from a national cohort of middle.......4%-34.5%), and opposite sex (21.4%; 95% CI, 12.0%-33.4%) dizygotic twins. Despite shared childhoods, only 1 of 617 pairs was concordant with respect to lineage. Although heritability increased for S. aureus and lineage persistency, no significant heritability was detected. Conclusion. In this study, host genetic factors...

  5. Factors Influencing the Adoption of Minimally Invasive Surgery

    African Journals Online (AJOL)

    of institutional, patient and surgeon-related factors ... Surgical site infections ... Factors influencing choice of open procedures over MIS are summarized in Table 1. The main .... written with pharmaceutical products in mind (25). ... JAMA Intern.

  6. External factors influencing the environmental performance of South African firms

    CSIR Research Space (South Africa)

    Peart, R

    2001-01-01

    Full Text Available This article reviews the external factors that influence environmental performance of companies in South Africa, drawing on international and local literature. After considering factors within the natural, social, economic and institutional...

  7. Factors influencing knowledge and practice of exclusive ...

    African Journals Online (AJOL)

    The independent variables were maternal education, marital status, both ... maternal employment status, health factors (place of delivery and maternal chronic illness) ... It was evident that family support is a key factor in the success of EBF with ...

  8. Factors influencing electric utility expansion. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Masud, E. [ed.

    1977-01-01

    This report, Vol. 2, submitted by the General Electric Co., identifies factors that should be considered in planning interconnected systems and discusses how these factors relate to one another. The objective is to identify all the factors and classify them by their use and importance in arriving at a decision. Chapter 2 discusses the utility system and its system behavior characteristics, emphasizing behavior that affects the planning of the bulk-power generation and transmission system. Chapter 3 introduces interconnection planning by discussing the new system characteristics brought to operation and planning. Forty-two factors associated with cost, reliability, constraints, and coordination are related to each other by factor trees. Factor trees display the relationship of one factor such as reliability to more-detailed factors which in turn are further related to individual characteristics of facilities. These factor trees provide a structure to the presentation. A questionnaire including the 42 factors was completed by 52 system planners from utility companies and government authorities. The results of these questionnaires are tabulated and presented with pertinent discussion of each factor. Chapter 4 deals with generation planning, recognizing the existence of interconnections. Chapter 5 addresses transmission planning, questions related to reliability and cost measures and constraints, and factors related to both analytical techniques and planning procedures. The chapter ends with a discussion of combined generation-transmission planning. (MCW)

  9. Host factors and genetic susceptibility to infections due to intracellular bacteria and fastidious organisms.

    Science.gov (United States)

    Asner, S A; Morré, S A; Bochud, P-Y; Greub, G

    2014-12-01

    While genetic polymorphisms play a paramount role in tuberculosis (TB), less is known about their contribution to the severity of diseases caused by other intracellular bacteria and fastidious microorganisms. We searched electronic databases for observational studies reporting on host factors and genetic predisposition to infections caused by intracellular fastidious bacteria published up to 30 May 2014. The contribution of genetic polymorphisms was documented for TB. This includes genetic defects in the mononuclear phagocyte/T helper cell type 1 (Th1) pathway contributing to disseminated TB disease in children and genome-wide linkage analysis (GWAS) in reactivated pulmonary TB in adults. Similarly, experimental studies supported the role of host genetic factors in the clinical presentation of illnesses resulting from other fastidious intracellular bacteria. These include IL-6 -174G/C or low mannose-binding (MBL) polymorphisms, which are incriminated in chronic pulmonary conditions triggered by C. pneumoniae, type 2-like cytokine secretion polymorphisms, which are correlated with various clinical patterns of M. pneumoniae infections, and genetic variation in the NOD2 gene, which is an indicator of tubal pathology resulting from Chamydia trachomatis infections. Monocyte/macrophage migration and T lymphocyte recruitment defects are corroborated to ineffective granuloma formation observed among patients with chronic Q fever. Similar genetic polymorphisms have also been suggested for infections caused by T. whipplei although not confirmed yet. In conclusion, this review supports the paramount role of genetic factors in clinical presentations and severity of infections caused by intracellular fastidious bacteria. Genetic predisposition should be further explored through such as exome sequencing.

  10. Extrapulmonary tuberculosis: Mycobacterium tuberculosis strains and host risk factors in a large urban setting in Brazil.

    Directory of Open Access Journals (Sweden)

    Teresa Gomes

    Full Text Available BACKGROUND: Factors related to the development of extrapulmonary forms of tuberculosis (EPTB are still poorly understood, particularly in high-endemic countries like Brazil. The objective of the paper is to determine host and Mycobacterium tuberculosis (MTB strain-related factors associated with the development of EPTB in Espírito Santo state, Brazil. METHODS AND FINDINGS: We conducted a retrospective laboratory-based surveillance study of new tuberculosis (TB cases diagnosed in Espírito Santo state, Brazil between 1998 and 2007. We genotyped 612 isolates of MTB from 606 TB patients using spoligotyping and IS6110-restriction fragment length polymorphism (RFLP typing and compared sociodemographic and clinical characteristics of patients with pulmonary TB (PTB and EPTB. Among 606 patients, 464 (77% had PTB, 79 (13% had EPTB, 51 (8% had both, and 12 (2% had miliary TB. The IS6110 RFLP analysis demonstrated that 250 (41% isolates belonged to clustered RFLP patterns, 27 (11% of which were from EPTB. We identified 73 clusters including 35 (48% composed of 2 isolates each. By spoligotyping, 506 (83% MTB isolates fell into known patterns and 106 (17% fell into patterns with no family assignment; 297 (48% isolates belonged to the Latin-American Mediterranean family. Higher school level (4-7 years OR: 0.16 95% CI 0.34-0.73 and > 8 years of education, OR 0.06 95% CI 0.009-0.50 white ethnicity (OR: 2.54 95% CI 1.03-6.25 and HIV infection (OR: 16.83 95% CI 5.23-54.18 were associated with EPTB. No specific strain lineage or percentage of clustering was associated with EPTB. CONCLUSIONS: These results demonstrate that risk factors for EPTB are related more to host than to MTB strain lineage characteristics.

  11. Community Factors Influencing Birth Spacing among Married ...

    African Journals Online (AJOL)

    AJRH Managing Editor

    outcomes. This study investigates community-level influences on birth spacing outcomes among women aged 15-49 in Uganda ...... childhood stunting in nigeria: A multilevel analysis. ... Equity monitoring for social marketing: Use of wealth.

  12. Dermal factors influencing measurement of skin autofluorescence

    NARCIS (Netherlands)

    Noordzij, Margaretha J.; Lefrandt, Johan; Graaff, Reindert; Smit, Andries J.

    Background: Skin autofluorescence (SAF) is a noninvasive marker of accumulation of advanced glycation end products. It predicts cardiovascular complications and mortality in diabetes and renal failure. We assessed the influence of potential common confounders in SAF measurement, by determining the

  13. Experimental infections with Mycoplasma agalactiae identify key factors involved in host-colonization.

    Directory of Open Access Journals (Sweden)

    Eric Baranowski

    Full Text Available Mechanisms underlying pathogenic processes in mycoplasma infections are poorly understood, mainly because of limited sequence similarities with classical, bacterial virulence factors. Recently, large-scale transposon mutagenesis in the ruminant pathogen Mycoplasma agalactiae identified the NIF locus, including nifS and nifU, as essential for mycoplasma growth in cell culture, while dispensable in axenic media. To evaluate the importance of this locus in vivo, the infectivity of two knock-out mutants was tested upon experimental infection in the natural host. In this model, the parental PG2 strain was able to establish a systemic infection in lactating ewes, colonizing various body sites such as lymph nodes and the mammary gland, even when inoculated at low doses. In these PG2-infected ewes, we observed over the course of infection (i the development of a specific antibody response and (ii dynamic changes in expression of M. agalactiae surface variable proteins (Vpma, with multiple Vpma profiles co-existing in the same animal. In contrast and despite a sensitive model, none of the knock-out mutants were able to survive and colonize the host. The extreme avirulent phenotype of the two mutants was further supported by the absence of an IgG response in inoculated animals. The exact role of the NIF locus remains to be elucidated but these data demonstrate that it plays a key role in the infectious process of M. agalactiae and most likely of other pathogenic mycoplasma species as many carry closely related homologs.

  14. An siRNA Screen Identifies the U2 snRNP Spliceosome as a Host Restriction Factor for Recombinant Adeno-associated Viruses.

    Science.gov (United States)

    Schreiber, Claire A; Sakuma, Toshie; Izumiya, Yoshihiro; Holditch, Sara J; Hickey, Raymond D; Bressin, Robert K; Basu, Upamanyu; Koide, Kazunori; Asokan, Aravind; Ikeda, Yasuhiro

    2015-08-01

    Adeno-associated viruses (AAV) have evolved to exploit the dynamic reorganization of host cell machinery during co-infection by adenoviruses and other helper viruses. In the absence of helper viruses, host factors such as the proteasome and DNA damage response machinery have been shown to effectively inhibit AAV transduction by restricting processes ranging from nuclear entry to second-strand DNA synthesis. To identify host factors that might affect other key steps in AAV infection, we screened an siRNA library that revealed several candidate genes including the PHD finger-like domain protein 5A (PHF5A), a U2 snRNP-associated protein. Disruption of PHF5A expression selectively enhanced transgene expression from AAV by increasing transcript levels and appears to influence a step after second-strand synthesis in a serotype and cell type-independent manner. Genetic disruption of U2 snRNP and associated proteins, such as SF3B1 and U2AF1, also increased expression from AAV vector, suggesting the critical role of U2 snRNP spliceosome complex in this host-mediated restriction. Notably, adenoviral co-infection and U2 snRNP inhibition appeared to target a common pathway in increasing expression from AAV vectors. Moreover, pharmacological inhibition of U2 snRNP by meayamycin B, a potent SF3B1 inhibitor, substantially enhanced AAV vector transduction of clinically relevant cell types. Further analysis suggested that U2 snRNP proteins suppress AAV vector transgene expression through direct recognition of intact AAV capsids. In summary, we identify U2 snRNP and associated splicing factors, which are known to be affected during adenoviral infection, as novel host restriction factors that effectively limit AAV transgene expression. Concurrently, we postulate that pharmacological/genetic manipulation of components of the spliceosomal machinery might enable more effective gene transfer modalities with recombinant AAV vectors.

  15. An siRNA Screen Identifies the U2 snRNP Spliceosome as a Host Restriction Factor for Recombinant Adeno-associated Viruses.

    Directory of Open Access Journals (Sweden)

    Claire A Schreiber

    2015-08-01

    Full Text Available Adeno-associated viruses (AAV have evolved to exploit the dynamic reorganization of host cell machinery during co-infection by adenoviruses and other helper viruses. In the absence of helper viruses, host factors such as the proteasome and DNA damage response machinery have been shown to effectively inhibit AAV transduction by restricting processes ranging from nuclear entry to second-strand DNA synthesis. To identify host factors that might affect other key steps in AAV infection, we screened an siRNA library that revealed several candidate genes including the PHD finger-like domain protein 5A (PHF5A, a U2 snRNP-associated protein. Disruption of PHF5A expression selectively enhanced transgene expression from AAV by increasing transcript levels and appears to influence a step after second-strand synthesis in a serotype and cell type-independent manner. Genetic disruption of U2 snRNP and associated proteins, such as SF3B1 and U2AF1, also increased expression from AAV vector, suggesting the critical role of U2 snRNP spliceosome complex in this host-mediated restriction. Notably, adenoviral co-infection and U2 snRNP inhibition appeared to target a common pathway in increasing expression from AAV vectors. Moreover, pharmacological inhibition of U2 snRNP by meayamycin B, a potent SF3B1 inhibitor, substantially enhanced AAV vector transduction of clinically relevant cell types. Further analysis suggested that U2 snRNP proteins suppress AAV vector transgene expression through direct recognition of intact AAV capsids. In summary, we identify U2 snRNP and associated splicing factors, which are known to be affected during adenoviral infection, as novel host restriction factors that effectively limit AAV transgene expression. Concurrently, we postulate that pharmacological/genetic manipulation of components of the spliceosomal machinery might enable more effective gene transfer modalities with recombinant AAV vectors.

  16. Influence of Lactic Acid Bacteria on Longevity of Caenorhabditis elegans and Host Defense against Salmonella enterica Serovar Enteritidis▿

    OpenAIRE

    Ikeda, Takanori; Yasui, Chikako; Hoshino, Kaori; Arikawa, Kentaro; Nishikawa, Yoshikazu

    2007-01-01

    This study aimed to develop a convenient model to investigate the senescence of host defenses and the influence of food and nutrition. A small soil nematode, Caenorhabditis elegans, was grown for 3 days from hatching on a lawn of Escherichia coli OP50 as the normal food source, and subsequently some of the nematodes were fed lactic acid bacteria (LAB). The life spans of worms fed LAB were significantly longer than the life spans of those fed OP50. To investigate the effect of age on host defe...

  17. Socio-economic, cultural and livelihood factors influencing local ...

    African Journals Online (AJOL)

    Socio-economic, cultural and livelihood factors influencing local people ... The social and economic circumstances prevailing in Tanzania today have made ... sociocultural and livelihood factors that influence community participation in ... Increased capacity for conservation skills was the most important driver of community ...

  18. Analysis of Factors Influencing Farmers’ Identification of Entrepreneurial Opportunity

    Institute of Scientific and Technical Information of China (English)

    Jing; GAO; Fang; YANG

    2013-01-01

    Based on the survey data of entrepreneurship concerning farmers in China,this article uses the multivariate adjustment regression analysis method,to analyze the factors influencing farmers’ identification of entrepreneurial opportunity and the mechanism. The results show that demographic characteristics are still an important factor influencing farmers’ identification of entrepreneurial opportunity,but the extent of its influence is weaker than entrepreneurs’ trait. The new trait theory is verified in farmers’ entrepreneurship opportunity behavior; entrepreneurship environment is becoming an important factor influencing entrepreneurial opportunity identification,whose regulation effect on entrepreneurs’ social network and previous experience is stronger than the regulation effect on entrepreneurs’ psychological trait.

  19. Influence of host diversity on development of epidemics: An evaluation and elaboration of mixture theory

    NARCIS (Netherlands)

    Skelsey, P.; Rossing, W.A.H.; Kessel, G.J.T.; Powell, J.; Werf, van der W.

    2005-01-01

    A spatiotemporal/integro-difference equation model was developed and utilized to study the progress of epidemics in spatially heterogeneous mixtures of susceptible and resistant host plants. The effects of different scales and patterns of host genotypes on the development of focal and general epidem

  20. Identification and Structural Basis of Binding to Host Lung Glycogen by Streptococcal Virulence Factors

    Energy Technology Data Exchange (ETDEWEB)

    Lammerts van Bueren,A.; Higgins, M.; Wang, D.; Burke, R.; Boraston, A.

    2007-01-01

    The ability of pathogenic bacteria to recognize host glycans is often essential to their virulence. Here we report structure-function studies of previously uncharacterized glycogen-binding modules in the surface-anchored pullulanases from Streptococcus pneumoniae (SpuA) and Streptococcus pyogenes (PulA). Multivalent binding to glycogen leads to a strong interaction with alveolar type II cells in mouse lung tissue. X-ray crystal structures of the binding modules reveal a novel fusion of tandem modules into single, bivalent functional domains. In addition to indicating a structural basis for multivalent attachment, the structure of the SpuA modules in complex with carbohydrate provides insight into the molecular basis for glycogen specificity. This report provides the first evidence that intracellular lung glycogen may be a novel target of pathogenic streptococci and thus provides a rationale for the identification of the streptococcal {alpha}-glucan-metabolizing machinery as virulence factors.

  1. Time resolved bovine host reponse to virulence factors mapped in milk by selected reaction monitoring

    DEFF Research Database (Denmark)

    Bislev, Stine Lønnerup; Kusebauch, Ulrike; Codrea, Marius Cosmin

    TIME RESOLVED BOVINE HOST RESPONSE TO VIRULENCE FACTORS, MAPPED IN MILK BY SELECTED REACTION MONITORING S.L. Bislev1, U. Kusebauch2, M.C. Codrea1, R. Moritz2, C.M. Røntved1, E. Bendixen1 1 Department of Animal Science, Faculty of Science and Technology, Aarhus University, Tjele, Denmark; 2...... Institute for Systems Biology, Seattle, Washington, USA Mastitis is beyond doubt the largest health problem in modern milk production. Many different pathogens can cause infections in the mammary gland, and give rise to severe toll on animal welfare, economic gain as well as on excessive use of antibiotics...... in food production. Rapid diagnostic methods are still not available, and particularly pathogen-specific biomarkers would be highly valuable, as these may allow correct antibiotic treatment to be applied shortly after an udder infection has been observed. Moreover, with automatic milking systems and on...

  2. Time resolved bovine host reponse to virulence factors mapped in milk by selected reaction monitoring

    DEFF Research Database (Denmark)

    Bislev, Stine Lønnerup; Kusebauch, Ulrike; Codrea, Marius Cosmin

    in food production. Rapid diagnostic methods are still not available, and particularly pathogen-specific biomarkers would be highly valuable, as these may allow correct antibiotic treatment to be applied shortly after an udder infection has been observed. Moreover, with automatic milking systems and on-line....... Furthermore, this SRM approach provides a strong tool for investigating these proteins in very large scale experiments, particularly with the scope to investigate whether these candidate biomarkers are suited for monitoring animal health in milk production.......TIME RESOLVED BOVINE HOST RESPONSE TO VIRULENCE FACTORS, MAPPED IN MILK BY SELECTED REACTION MONITORING S.L. Bislev1, U. Kusebauch2, M.C. Codrea1, R. Moritz2, C.M. Røntved1, E. Bendixen1 1 Department of Animal Science, Faculty of Science and Technology, Aarhus University, Tjele, Denmark; 2...

  3. Host-related factors explaining interindividual variability of carotenoid bioavailability and tissue concentrations in humans

    DEFF Research Database (Denmark)

    Bohn, Torsten; Desmarchelier, Charles; Dragsted, Lars Ove

    2017-01-01

    Carotenoid dietary intake and their endogenous levels have been associated with a decreased risk of several chronic diseases. There are indications that carotenoid bioavailability depends, in addition to the food matrix, on host factors. These include diseases (e.g. colitis), life-style habits (e.......g. smoking), gender and age, as well as genetic variations including single nucleotide polymorphisms that govern carotenoid metabolism. These are expected to explain interindividual differences that contribute to carotenoid uptake, distribution, metabolism and excretion, and therefore possibly also...... their association with disease risk. For instance, digestion enzymes fostering micellization (PNLIP, CES), expression of uptake/efflux transporters (SRARB1, CD36, NPC1L1), cleavage enzymes (BCO1/2), intracellular transporters (FABP2), secretion into chylomicrons (APOB, MTTP), carotenoid metabolism in the blood...

  4. Host-related factors explaining interindividual variability of carotenoid bioavailability and tissue concentrations in humans

    DEFF Research Database (Denmark)

    Bohn, Torsten; Desmarchelier, Charles; Dragsted, Lars Ove

    2017-01-01

    Carotenoid dietary intake and their endogenous levels have been associated with a decreased risk of several chronic diseases. There are indications that carotenoid bioavailability depends, in addition to the food matrix, on host factors. These include diseases (e.g. colitis), life-style habits (e.......g. smoking), gender and age, as well as genetic variations including single nucleotide polymorphisms that govern carotenoid metabolism. These are expected to explain interindividual differences that contribute to carotenoid uptake, distribution, metabolism and excretion, and therefore possibly also...... their association with disease risk. For instance, digestion enzymes fostering micellization (PNLIP, CES), expression of uptake/efflux transporters (SRARB1, CD36, NPC1L1), cleavage enzymes (BCO1/2), intracellular transporters (FABP2), secretion into chylomicrons (APOB, MTTP), carotenoid metabolism in the blood...

  5. The roles of host and pathogen factors and the innate immune response in the pathogenesis of Clostridium difficile infection

    Science.gov (United States)

    Sun, Xingmin; Hirota, Simon A.

    2014-01-01

    Clostridium difficile (C. difficile) is the most common cause of nosocomial antibiotic-associated diarrhea and the etiologic agent of pseudomembranous colitis. The clinical manifestation of Clostridium difficile infection (CDI) is highly variable, from asymptomatic carriage, to mild self-limiting diarrhea, to the more severe pseudomembranous colitis. Furthermore, in extreme cases, colonic inflammation and tissue damage can lead to toxic megacolon, a condition requiring surgical intervention. C. difficile expresses two key virulence factors; the exotoxins, toxin A (TcdA) and toxin B (TcdB), which are glucosyltransferases that target host-cell monomeric GTPases. In addition, some hypervirulent strains produce a third toxin, binary toxin or C. difficile transferase (CDT), which may contribute to the pathogenesis of CDI. More recently, other factors such as surface layer proteins (SLPs) and flagellin have also been linked to the inflammatory responses observed in CDI. Although the adaptive immune response can influence the severity of CDI, the innate immune responses to C. difficile and its toxins play crucial roles in CDI onset, progression, and overall prognosis. Despite this, the innate immune responses in CDI have drawn relatively little attention from clinical researchers. Targeting these responses may prove useful clinically as adjuvant therapies, especially in refractory and/or recurrent CDI. This review will focus on recent advances in our understanding of how C. difficile and its toxins modulate innate immune responses that contribute to CDI pathogenesis. PMID:25242213

  6. Highlights Regarding Host Predisposing Factors to Recurrent Vulvovaginal Candidiasis: Chronic Stress and Reduced Antioxidant Capacity.

    Directory of Open Access Journals (Sweden)

    Luciene Akimoto-Gunther

    Full Text Available We studied host factors that could predispose women to develop recurrent vulvovaginal candidiasis (RVVC, including glycemia, insulin resistance, chronic stress, antioxidant capacity, overall immune status, local inflammation and vaginal microbiota. The presence of yeasts in vaginal culture was screened in 277 women, with or without signs and symptoms of VVC and RVVC. The presence of an inflammatory process and microbiota were analyzed through vaginal bacterioscopy and cervical-vaginal cytology, respectively. Fasting-blood samples were collected by standard venipuncture for biochemical analyses. Flow cytometry was employed to obtain the T helper/T cytotoxic lymphocyte ratio, and insulin resistance was assessed by the HOMA index (HI. Yeasts were isolated from 71 (26% women: 23 (32.4% with a positive culture but without symptoms (COL, 22 (31% in an acute episode (VVC, and 26 (36.6% with RVVC. C. albicans was the main yeast isolated in all clinical profiles. The control group (negative culture comprised 206 women. Diabetes mellitus and insulin resistance were more associated with the positive-culture groups (COL, VVC and RVVC than with negative ones. The RVVC group showed lower mean levels of cortisol than the control group and lower antioxidant capacity than all other groups. The T Helper/T cytotoxic lymphocyte ratio was similar in all groups. The RVVC group showed a similar level of vaginal inflammation to the control group, and lower than in the COL and VVC groups. Only the CVV group showed a reduction in vaginal lactobacillus microbiota. Our data suggest that both chronic stress (decreased early-morning cortisol levels and reduced antioxidant capacity can be host predisposing factors to RVVC.

  7. Highlights Regarding Host Predisposing Factors to Recurrent Vulvovaginal Candidiasis: Chronic Stress and Reduced Antioxidant Capacity

    Science.gov (United States)

    Akimoto-Gunther, Luciene; Bonfim-Mendonça, Patrícia de Souza; Takahachi, Gisele; Irie, Mary Mayumi T.; Miyamoto, Sônia; Consolaro, Márcia Edilaine Lopes; Svidzinsk, Terezinha I. Estivalet

    2016-01-01

    We studied host factors that could predispose women to develop recurrent vulvovaginal candidiasis (RVVC), including glycemia, insulin resistance, chronic stress, antioxidant capacity, overall immune status, local inflammation and vaginal microbiota. The presence of yeasts in vaginal culture was screened in 277 women, with or without signs and symptoms of VVC and RVVC. The presence of an inflammatory process and microbiota were analyzed through vaginal bacterioscopy and cervical-vaginal cytology, respectively. Fasting-blood samples were collected by standard venipuncture for biochemical analyses. Flow cytometry was employed to obtain the T helper/T cytotoxic lymphocyte ratio, and insulin resistance was assessed by the HOMA index (HI). Yeasts were isolated from 71 (26%) women: 23 (32.4%) with a positive culture but without symptoms (COL), 22 (31%) in an acute episode (VVC), and 26 (36.6%) with RVVC. C. albicans was the main yeast isolated in all clinical profiles. The control group (negative culture) comprised 206 women. Diabetes mellitus and insulin resistance were more associated with the positive-culture groups (COL, VVC and RVVC) than with negative ones. The RVVC group showed lower mean levels of cortisol than the control group and lower antioxidant capacity than all other groups. The T Helper/T cytotoxic lymphocyte ratio was similar in all groups. The RVVC group showed a similar level of vaginal inflammation to the control group, and lower than in the COL and VVC groups. Only the CVV group showed a reduction in vaginal lactobacillus microbiota. Our data suggest that both chronic stress (decreased early-morning cortisol levels) and reduced antioxidant capacity can be host predisposing factors to RVVC. PMID:27415762

  8. Neurocysticercosis: the effectiveness of the cysticidal treatment could be influenced by the host immunity.

    Science.gov (United States)

    Cárdenas, Graciela; Fragoso, Gladis; Rosetti, Marcos; Uribe-Figueroa, Laura; Rangel-Escareño, Claudia; Saenz, Brenda; Hernández, Marisela; Sciutto, Edda; Fleury, Agnes

    2014-12-01

    Neurocysticercosis, a clinically and radiologically pleomorphic parasitic disease, is still endemic to most non-developed countries of Latin America, Africa, and Asia. Anti-helminthic drugs (AHD) are generally effective and rapidly destroy parenchymal cysticerci. In contrast, several cycles of AHD are frequently necessary to damage extraparenchymally located parasites. The present study was designed to evaluate whether differences in the immunological profile of the patients is involved in the diversity of the response to AHD. To this end, a global gene expression microarray and a cytokine analysis were made. Responder patients were those showing a radiological reduction greater than 50 % in the parasite burden following AHD treatment. Microarray pre- and post-treatment comparisons showed that a total of eighteen immune-related genes were up-regulated in the five responder patients with respect the expression profile seen in the four non-responder subjects. The function of up-regulated genes exerted pro-inflammatory (RORγC, Sema4A, SLAMF3, SLAMF6), anti-inflammatory (TGFβ, TNFRSF25, TNFRS18, SLAMF1, ILF2), or immunomodulatory effects (CXCL2, RUNX3, SLAMF9, TGFBR3). To further explore the causes of the heterogeneity in the response to treatment, a wide ELISA cytokine analysis was performed in serum, PBMC supernatants, and CSF samples from 39 responder and 26 non-responder patients. Responder patients showed higher CSF IL-17A levels (P = 0.04) and higher supernatant IL-6 levels (P = 0.03) 60 days after treatment. These results suggest a possible influence of pro-inflammatory cytokines on the response to AHD as observed by radiological methods, and thus the possible participation of the host immunity in the effectiveness of AHD treatment.

  9. Genome-Wide Search for Host Association Factors during Ovine Progressive Pneumonia Virus Infection.

    Directory of Open Access Journals (Sweden)

    Jesse Thompson

    Full Text Available Ovine progressive pneumonia virus (OPPV is an important virus that causes serious diseases in sheep and goats with a prevalence of 36% in the USA. Although OPPV was discovered more than half of a century ago, little is known about the infection and pathogenesis of this virus. In this report, we used RNA-seq technology to conduct a genome-wide probe for cellular factors that are associated with OPPV infection. A total of approximately 22,000 goat host genes were detected of which 657 were found to have been significantly up-regulated and 889 down-regulated at 12 hours post-infection. In addition to previously known restriction factors from other viral infections, a number of factors which may be specific for OPPV infection were uncovered. The data from this RNA-seq study will be helpful in our understanding of OPPV infection, and also for further study in the prevention and intervention of this viral disease.

  10. Optimization of reporter gene assay: several factors influencing detection of promoter activity

    Institute of Scientific and Technical Information of China (English)

    XUE Li-xiang; WENG Mo; ZHANG Zong-yu; TONG Tan-jun

    2007-01-01

    Background Promoter analysis is currently applied to detect the expression of the targeted gene in studies of signal transduction and transcriptional regulation. As a reporter gene, luciferase plays an important role and has been used widely in the promoter assay.Methods Human embryonic lung fibroblast cells (2BS), HeLa cells and MCF-7 cells were transfected with various genes embedded by lipofectamine. This study determined various factors that affect promoter activity determination,such as the selection of the reporter genes and internal references, the dose and the type of the vectors carrying the transcription factors, the host cells and the instruments.Results The sensitivity of the luciferase assay was much higher than that of enhanced green fluorescence protein (EGFP). Moreover, promoter activity is increased in a dose-related manner only in certain ranges outside of which the results may be reversed and the promoter activity is related to the expression vector which is carrying the cDNA.Otherwise, the length of the promoter, internal references and the host cell can also influence the promoter activity.Conclusions To detect the promoter activity accurately, a few factors including dose, vector, length and host cell which influence reporter gene assay aforementioned should be considered.

  11. FACTORS INFLUENCING FRICTION OF PHOSPHATE COATINGS,

    Science.gov (United States)

    surface roughness, crystalline structure , and velocity. The coefficients of friction for manganese phosphate coatings did not differ to any practical...The coefficient of friction was independent of the applied load. Velocity during dynamic testing, surface finish, and crystalline structure influenced

  12. Dermal factors influencing measurement of skin autofluorescence

    NARCIS (Netherlands)

    Noordzij, Margaretha J.; Lefrandt, Johan; Graaff, Reindert; Smit, Andries J.

    2011-01-01

    Background: Skin autofluorescence (SAF) is a noninvasive marker of accumulation of advanced glycation end products. It predicts cardiovascular complications and mortality in diabetes and renal failure. We assessed the influence of potential common confounders in SAF measurement, by determining the e

  13. The influence of host genetics on erythrocytes and malaria infection: is there therapeutic potential?

    Science.gov (United States)

    Lelliott, Patrick M; McMorran, Brendan J; Foote, Simon J; Burgio, Gaetan

    2015-07-29

    As parasites, Plasmodium species depend upon their host for survival. During the blood stage of their life-cycle parasites invade and reside within erythrocytes, commandeering host proteins and resources towards their own ends, and dramatically transforming the host cell. Parasites aptly avoid immune detection by minimizing the exposure of parasite proteins and removing themselves from circulation through cytoadherence. Erythrocytic disorders brought on by host genetic mutations can interfere with one or more of these processes, thereby providing a measure of protection against malaria to the host. This review summarizes recent findings regarding the mechanistic aspects of this protection, as mediated through the parasites interaction with abnormal erythrocytes. These novel findings include the reliance of the parasite on the host enzyme ferrochelatase, and the discovery of basigin and CD55 as obligate erythrocyte receptors for parasite invasion. The elucidation of these naturally occurring malaria resistance mechanisms is increasing the understanding of the host-parasite interaction, and as discussed below, is providing new insights into the development of therapies to prevent this disease.

  14. Leptospira seroprevalence and associations between seropositivity, clinical disease and host factors in horses

    Directory of Open Access Journals (Sweden)

    Engvall E Olsson

    2009-03-01

    Full Text Available Abstract Background A cross-sectional study was carried out to determine the seroprevalence of different serovars of Leptospira spp. and their association with clinical disease and host factors in Swedish horses. Methods Sera from 2017 horses brought to equine clinics during 1997–98 were investigated. The sera were examined by microscopic agglutination test for the presence of antibodies against the following L. interrogans serovars: Bratislava strain Jez, Icterohaemorrhagiae strain Kantorowicz and Pomona strain Pomona and also L. kirschneri sv Grippotyphosa strain Duyster and L. borgpetersenii sv Sejroe strain M 84. Host factors, disease factors, season, pasture access and outdoor confinement variables were analysed with respect to seropositivity to sv Bratislava and Icterohaemorrhagiae. Multivariable logistic regression was used to model seropositivity to sv Bratislava and Icterohaemorrhagiae (seroprevalence > 8%. Results The seroprevalence, at a cut-off 1:100, were for sv Bratislava (16.6%, Icterohaemorrhagiae (8.3%, Sejroe (1.2%, Pomona (0.5% and Grippotyphosa (0.4%. In the multivariable analysis, it was demonstrated that seroprevalence increased with age for sv Bratislava and Icterohaemorrhagiae. For sv Bratislava the seasons April – June and October – December and for sv Icterohaemorrhagiae October – December had higher seroprevalences than other seasons. Horses not used for racing had higher levels of seropositivity to sv Bratislava. Furthermore, horses with respiratory problems as well as horses with fatigue had higher levels of seropositivity to sv Bratislava. Ponies and coldbloods, and horses with access to pasture, had lower seroprevalence for sv Icterohaemorrhagiae. Healthy horses had lower seroprevalence for sv Icterohaemorrhagiae, than non-healthy horses. Conclusion There was no significant association between clinical signs and disease and positive titres to sv Bratislava (except for the association between respiratory

  15. Factors influencing societal response of nanotechnology : an expert stakeholder analysis

    OpenAIRE

    2012-01-01

    Nanotechnology can be described as an emerging technology and, as has been the case with other emerging technologies such as genetic modification, different socio-psychological factors will potentially influence societal responses to its development and application. These factors will play an important role in how nanotechnology is developed and commercialised. This article aims to identify expert opinion on factors influencing societal response to applications of nanotechnology. Structured i...

  16. Abiotic and biotic factors associated with tick population dynamics on a mammalian host: Ixodes hexagonus infesting otters, Lutra lutra.

    Directory of Open Access Journals (Sweden)

    Ellie Sherrard-Smith

    Full Text Available The Eurasian otter, Lutra lutra, hosts several parasites with zoonotic potential. As this semiaquatic mammal has large ranges across terrestrial, freshwater and marine habitats, it has the capacity for wide dispersion of pathogens. Despite this, parasites of otters have received relatively little attention. Here, we examine their ectoparasite load and assess whether this is influenced by abiotic or biotic variables. Climatic phenomena such as the North Atlantic Oscillation (NAO affect weather conditions in northern Europe. Consequently parasite distributions, particularly species with life stages exposed to the external environment, can be affected. We assessed the extent to which inter-annual variations in large-scale weather patterns (specifically the NAO and Central England (CE temperatures and host characteristics influenced tick prevalence and intensity. Ectoparasites consisted of a single species, the nidiculous tick Ixodes hexagonus (prevalence = 24.3%; mean intensity = 7.2; range = 1-122; on n = 820 otter hosts. The prevalence, but not intensity of infestation, was associated with high CE temperatures, while both prevalence and intensity were associated with positive phases of the NAO. Such associations indicate that I. hexagonus are most abundant when weather conditions are warmer and wetter. Ticks were more prevalent on juvenile than sub-adult or adult otters, which probably reflects the length of time the hosts spend in the holt where these ticks quest. High tick number was associated with poor host condition, so either poor condition hosts are more susceptible to ticks, or tick infestations negatively impact on host condition. Otters are clearly an important and common host for I. hexagonus, which has implications for vector-borne diseases. This work is the first to consider the impacts of long-term weather patterns on I. hexagonus and uses wild-animal cadavers to illustrate the importance of abiotic and biotic pressures impacting

  17. Factors Influencing Job Satisfaction among Army Chaplains

    Science.gov (United States)

    1976-05-20

    supported by Maslow’s need hierarchy, it is not substantiated by Herzberg’s Two Factor Theory. Still another approach is that of Leon Festinger’s...Herzberg, Vroom, McGregor, Lawler and Festinger provide a basic JWM » -, —_—^ . foundation and starting point for examining the factors of chaplain...identity, and autonomy, which are examined in this section. Further, Leon Festinger’s work on "cognitive dissonance" points toward the

  18. Factors influencing consumer dietary health preventative behaviours

    OpenAIRE

    Petrovici, Dan A.; Ritson, Christopher

    2006-01-01

    Background The deterioration of the health status of the Romanian population during the economic transition from a centrally planned to a free market economy has been linked to lifestyles factors (e.g. diet) regarded as a main determinants of the disparity in life expectancy between Eastern and Western Europe. Reforms in the health care system in this transition economy aim to focus on preventive action. The purpose of this study was to identify the factors that impact on the individual decis...

  19. Influences of Host Community Characteristics on Borrelia burgdorferi Infection Prevalence in Blacklegged Ticks

    Science.gov (United States)

    Chiu, Grace S.; Smouse, Peter E.; Fonseca, Dina M.; Brisson, Dustin; Morin, Peter J.; Ostfeld, Richard S.

    2017-01-01

    Lyme disease is a major vector-borne bacterial disease in the USA. The disease is caused by Borrelia burgdorferi, and transmitted among hosts and humans, primarily by blacklegged ticks (Ixodes scapularis). The ~25 B. burgdorferi genotypes, based on genotypic variation of their outer surface protein C (ospC), can be phenotypically separated as strains that primarily cause human diseases—human invasive strains (HIS)—or those that rarely do. Additionally, the genotypes are non-randomly associated with host species. The goal of this study was to examine the extent to which phenotypic outcomes of B. burgdorferi could be explained by the host communities fed upon by blacklegged ticks. In 2006 and 2009, we determined the host community composition based on abundance estimates of the vertebrate hosts, and collected host-seeking nymphal ticks in 2007 and 2010 to determine the ospC genotypes within infected ticks. We regressed instances of B. burgdorferi phenotypes on site-specific characteristics of host communities by constructing Bayesian hierarchical models that properly handled missing data. The models provided quantitative support for the relevance of host composition on Lyme disease risk pertaining to B. burgdorferi prevalence (i.e. overall nymphal infection prevalence, or NIPAll) and HIS prevalence among the infected ticks (NIPHIS). In each year, NIPAll and NIPHIS was found to be associated with host relative abundances and diversity. For mice and chipmunks, the association with NIPAll was positive, but tended to be negative with NIPHIS in both years. However, the direction of association between shrew relative abundance with NIPAll or NIPHIS differed across the two years. And, diversity (H') had a negative association with NIPAll, but positive association with NIPHIS in both years. Our analyses highlight that the relationships between the relative abundances of three primary hosts and the community diversity with NIPAll, and NIPHIS, are variable in time and

  20. Influence of host preference, mating, and release density on the parasitism of Telenomus remus (Nixon (Hymenoptera, Platygastridae

    Directory of Open Access Journals (Sweden)

    Ana Paula de Queiroz

    Full Text Available ABSTRACT We evaluated the influence of host preference, mating, and release density on Telenomus remus (Nixon, 1937 (Hymenoptera: Platygastridae parasitizing eggs of Spodoptera frugiperda (Smith, 1797 (Lepidoptera: Noctuidae. First, we tested host preference of T. remus (free choice test offered a choice between eggs of Corcyra cephalonica (Stainton, 1865 (Lepidoptera: Pyralidae and S. frugiperda. Parasitism capacity and host preference (S. frugiperda of T. remus reared on either of the two hosts did not differ. Secondly, we evaluated the influence of mating behavior of T. remus females on its parasitism. Only the offspring sex ratio differed between treatments, indicating that the species reproduces by parthenogenesis of the arrhenotoky type. Finally, we evaluated the influence of release density on T. remus parasitism. This was tested by releasing different numbers of the parasitoid per S. frugiperda egg using T. remus reared for different numbers of generations on C. cephalonica eggs. The regression analysis between percentage of parasitism and density of released T. remus females showed a quadratic effect for all tested parasitoid generations (F35, F40, and F45 with maximum parasitism from 65.07% to 71.69%. Our results allow the conclusion that (a T. remus prefers S. frugiperda eggs, regardless of the host on which this parasitoid was reared, showing no preimaginal conditioning; (b Mating does not affect the number of eggs parasitized by T. remus or the development of its offspring; and (c The optimal T. remus release density when reared on C. cephalonica is between 0.133 and 0.150 females/S. frugiperda.

  1. Influences of leaf-mining insects on their host plants: A review

    Directory of Open Access Journals (Sweden)

    Liu, W. H.

    2015-12-01

    Full Text Available Leaf-mining insects are an herbivore group whose larvae live and feed inside plant leaves. Leaf mines are distinct marks on leaves and can provide much information on insect-plant relationships. Most leaf miners are monophagous or oligophagous. Therefore ecologists and paleontologists use them to study interactions and coevolution among plants, insects and natural enemies. There are many different types of leaf-mining patterns on plant leaves, which may have different impacts on host plants. Compared with ectophagous herbivores, leaf-mining insects should have unique influences on host plant characteristics, such as leaf morphology, leaf chemistry, plant physiology, plant growth and production. Obvious impacts include leaf asymmetry, callus formation, photosynthesis, and green islands. Types and degrees of such influences are varied for different leaf miner species or different host plant species. In turn, the change of plant features may have positive or negative impacts on oviposition and feeding of leaf-mining insects. Studies on plant responses to leaf-mining and the defensive mechanisms of plants are helpful in understanding the coevolution between leaf miners and their food plants.Los insectos minadores de hojas son un grupo de herbívoros cuyas larvas viven y se alimentan del interior de las hojas. Lo que denominamos minas son las diferentes marcas que quedan en las hojas y que pueden proporcionar valiosa información acerca de las relaciones planta-insecto. La mayoría de minadores son monófagos u oligófagos. Los ecólogos y paleontólogos los usan para estudiar las interacciones y la coevolución entre plantas, insectos y sus enemigos naturales. Existen numerosos tipos de patrones de minas en las hojas, que pueden producir diferentes impactos en la planta hospedadora. Si los comparamos con los insectos ectófagos, los minadores de hojas pueden tener una influencia muy característica en numerosos aspectos de la planta hospedadora

  2. Influence of Nutritional Factors on Lipid Metabolism.

    Science.gov (United States)

    1980-12-01

    conditions of chronic high level fat oxidation such as exercise, Askew et al. (121) fed exercising rats diets supplemented with 0.5Z L- carnitine . Although...exercise increased adipose tissue fatty acid turnover, supplemental dietary carnitine neither increased skeletal muscle in vitro fatty acid oxidation...some investigators believe the relative activities of the sn-glycerolphosphate acyltransferase and carnitine palmttyltrans- ferase may influence the

  3. Dermal factors influencing measurement of skin autofluorescence.

    Science.gov (United States)

    Noordzij, Margaretha J; Lefrandt, Joop D; Graaff, Reindert; Smit, Andries J

    2011-02-01

    Skin autofluorescence (SAF) is a noninvasive marker of accumulation of advanced glycation end products. It predicts cardiovascular complications and mortality in diabetes and renal failure. We assessed the influence of potential common confounders in SAF measurement, by determining the effects of endogenous and exogenous local dermal changes by body creams, hyperemia, vasoconstriction, and hydration. SAF was measured before and after local administration of body lotion, day cream, sunscreen, or self-browning cream and after attempts to remove these effects with alcohol swabs and washing. SAF was measured before and during three hyperemia maneuvers: vasoconstriction and on a dry and wet skin. The body lotion increased SAF by 18%. Day cream, sunscreen, and self-browning cream gave an increase of >100%. Except for body lotion, subsequent cleaning with alcohol swabs and washing with soap did not return SAF to baseline values. The effect of self-browning cream persisted for 2 weeks and that of sunscreen for 4 days. Hyperemia caused by a hot bath, capsicum cream, or postocclusive reactive hyperemia gave a decrease in SAF of, respectively, 18%, 22%, and 2.3%. Vasoconstriction caused by immersing the arm in cold water gave a 10% increase. Hydration state did not influence SAF. Measurement of SAF is strongly affected by several skin creams. This effect was often not fully corrected by alcohol swabs and washing with soap and may persist for many days. Marked hyperemia and vasoconstriction also influence SAF. We advise avoiding these potential error sources.

  4. Choice of treatment with antidepressants: influencing factors.

    Science.gov (United States)

    Himmerich, Hubertus; Wranik, Dominika W

    2012-01-01

    Depressive disorders place a large burden on patients and on society. Although efficacious treatment options for unipolar depressive disorders exist, substantial gaps in care remain. In part, the challenge lies in the matching of individual patients with appropriate care. This is complicated by the steady increases in the variety of antidepressants available in the market. The goal of this study is to highlight the decision processes in the selection of antidepressants by clinicians, given that most treatments have similar clinical effectiveness profiles. We conducted a systematic literature review of studies that referred to the decisions surrounding treatment with antidepressants for the treatment of non-psychotic unipolar depression. Our analysis of the literature reveals that the choice of treatment is based on a variety of factors, of which clinical evidence is only one. These factors can be categorized into clinical factors such as illness and treatment characteristics, individual factors such as patient and physician characteristics, and contextual factors such as setting characteristics, decision supports and pharmacoeconomic aspects. Illness characteristics are defined by the type and severity of depression. Treatment characteristics include drug properties, efficacy, effectiveness and favorable as well as unintended adverse effects of the drug. Examples for patient characteristics are co-morbidities and individual preferences, and physician characteristics include knowledge, experience, values and beliefs, and the relationship with the patient. Treatment guidelines, algorithms, and most recently, computational supports and biological markers serve as decision supports.

  5. Influence of early life exposure, host genetics and diet on the mouse gut microbiome and metabolome

    Energy Technology Data Exchange (ETDEWEB)

    Snijders, Antoine M.; Langley, Sasha A.; Kim, Young-Mo; Brislawn, Colin J.; Noecker, Cecilia; Zink, Erika M.; Fansler, Sarah J.; Casey, Cameron P.; Miller, Darla; Huang, Yurong; Karpen , Gary H.; Celniker, Susan E.; Brown, James B.; Borenstein, Elhanan A.; Jansson, Janet K.; Metz, Thomas O.; Mao, Jian-Hua

    2016-11-28

    Although the gut microbiome plays important roles in host physiology, health and disease1, we lack understanding of the complex interplay between host genetics and early life environment on the microbial and metabolic composition of the gut.We used the genetically diverse Collaborative Cross mouse system2 to discover that early life history impacts themicrobiome composition, whereas dietary changes have only a moderate effect. By contrast, the gut metabolome was shaped mostly by diet, with specific non-dietary metabolites explained by microbial metabolism. Quantitative trait analysis identified mouse genetic trait loci (QTL) that impact the abundances of specific microbes. Human orthologues of genes in the mouse QTL are implicated in gastrointestinal cancer. Additionally, genes located in mouse QTL for Lactobacillales abundance are implicated in arthritis, rheumatic disease and diabetes. Furthermore, Lactobacillales abundance was predictive of higher host T-helper cell counts, suggesting an important link between Lactobacillales and host adaptive immunity.

  6. Influence of early life exposure, host genetics and diet on the mouse gut microbiome and metabolome

    Energy Technology Data Exchange (ETDEWEB)

    Snijders, Antoine M.; Langley, Sasha A.; Kim, Young-Mo; Brislawn, Colin J.; Noecker, Cecilia; Zink, Erika M.; Fansler, Sarah J.; Casey, Cameron P.; Miller, Darla R.; Huang, Yurong; Karpen, Gary H.; Celniker, Susan E.; Brown, James B.; Borenstein, Elhanan; Jansson, Janet K.; Metz, Thomas O.; Mao, Jian-Hua

    2016-11-28

    Although the gut microbiome plays important roles in host physiology, health and disease1, we lack understanding of the complex interplay between host genetics and early life environment on the microbial and metabolic composition of the gut.We used the genetically diverse Collaborative Cross mouse system2 to discover that early life history impacts themicrobiome composition, whereas dietary changes have only a moderate effect. By contrast, the gut metabolome was shaped mostly by diet, with specific non-dietary metabolites explained by microbial metabolism. Quantitative trait analysis identified mouse genetic trait loci (QTL) that impact the abundances of specific microbes. Human orthologues of genes in the mouse QTL are implicated in gastrointestinal cancer. Additionally, genes located in mouse QTL for Lactobacillales abundance are implicated in arthritis, rheumatic disease and diabetes. Furthermore, Lactobacillales abundance was predictive of higher host T-helper cell counts, suggesting an important link between Lactobacillales and host adaptive immunity.

  7. Influence of host resistance on viral adaptation: hepatitis C virus as a case study

    OpenAIRE

    Plauzolles A; Lucas M; Gaudieri S

    2015-01-01

    Anne Plauzolles,1 Michaela Lucas,2,3 Silvana Gaudieri41Centre for Forensic Science, 2School of Medicine and Pharmacology, Harry Perkins Institute, 3School of Pathology and Laboratory Medicine, 4School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, WA, AustraliaAbstract: Genetic and cellular studies have shown that the host's innate and adaptive immune responses are an important correlate of viral infection outcome. The features of the host's ...

  8. Factors influencing quality of life in asthmatics

    DEFF Research Database (Denmark)

    Al-kalemji, Abir; Petersen, Karin Dam; Sørensen, Jan

    2013-01-01

    INTRODUCTION: The quality of life (QOL) in persons with asthma is reduced and different factors such as demography, asthma severity and psychiatric comorbidity play an influential role. However, little is known about the interplay of these factors. OBJECTIVE: To describe QOL in relation to asthma...... and analyse for the relative impact of asthma severity, psychiatric comorbidity, lifestyle (smoking and obesity) and demographic determinants on QOL in persons with asthma. METHODS: One thousand one hundred sixty-one subjects from an earlier cohort with and without asthma were sent an asthma screening...... gender and smoking were associated with reduced QOL, suggesting that these factors play an independent role on lowering QOL. Depression did not inflate the relationship between asthma severity and worse QOL, suggesting that asthma severity plays an independent role on everyday life regardless...

  9. Factors influencing nurses' participation in clinical research.

    Science.gov (United States)

    Jacobson, Ann F; Warner, Andrea M; Fleming, Eileen; Schmidt, Bruce

    2008-01-01

    Clinical research is necessary for developing nursing's body of knowledge and improving the quality of gastroenterology nursing care. The support and participation of nursing staff are crucial to conducting interventional research. Identification of characteristics of nurses and their work settings that facilitate or impede participation in research is needed. The purpose of this descriptive correlational study was to examine the effect of personal and professional characteristics and attitudes about nursing research on staff nurses' participation in a clinical nursing research project. A questionnaire measuring nurses' attitudes, perceptions of availability of support, and research use was distributed to staff nurses working on an endoscopy lab and two same-day surgery units where a nursing research study had recently been conducted. Investigator-developed items measured nurses' attitudes about the utility and feasibility of the interventions tested in the original study. A total of 36 usable questionnaires comprised the sample. Factor analysis of the two questionnaires resulted in three-factor (Importance of Research, Interest in Research, and Environment Support of Research) and two-factor (Value of Cognitive-Behavioral Interventions [CBIs] and Participation in Study) solutions, respectively. There were no statistically significant differences in mean scores for the five factors between nurses who did (n = 19) and those who did not (n = 17) participate in the original study. The Participation in Research Factor was significantly negatively correlated with years in nursing (r = -.336, p body of knowledge about factors that facilitate or impede staff nurses' involvement in research. This knowledge will be useful for nurse researchers planning intervention studies to forecast and foster staff nurse involvement in their projects. Findings may also be useful to nurse managers, nurse educators, and staff development personnel in assessing and promoting staff nurses

  10. Influencing factors of infrared surveying in roadway

    Institute of Scientific and Technical Information of China (English)

    CAI Kang-xu; GUO Da

    2006-01-01

    The main factors that affect infrared surveying in roadway include that property of rock, electromechanical equipments running, environmental temperature, hydrogeology and support material etc. This paper sums up the expression features of these disturbing factor through theoretical analysis and actual measurement contrasts and considers that some tunnel section does not suit to go on infrared survey, for instance, soft rock meets water to expanse, and surround rock has obviously pouring water. The basic methods had made evading disturbing of electromechanical equipments, environmental temperature and protect material etc to become possible. It is helpful that offers infrared surveying technical service for production safety better in roadway.

  11. Sphingosine kinase 2 is a chikungunya virus host factor co-localized with the viral replication complex.

    Science.gov (United States)

    Reid, St Patrick; Tritsch, Sarah R; Kota, Krishna; Chiang, Chih-Yuan; Dong, Lian; Kenny, Tara; Brueggemann, Ernest E; Ward, Michael D; Cazares, Lisa H; Bavari, Sina

    2015-10-01

    Chikungunya virus (CHIKV) is a re-emerging alphavirus which causes severe and prolonged arthralgic febrile illness. The recent global spread of the virus and lack of approved therapeutic options makes it imperative to gain greater insight into the molecular mechanisms underlying CHIKV pathogenesis, in particular host factors recruited by the virus. In the current study, we identify sphingosine kinase 2 (SK2) as a CHIKV host factor co-localized with the viral replication complex (VRC) during infection. SK2 was demonstrated to co-localize with viral RNA and nonstructural proteins. Targeted impairment of SK2 expression or function significantly inhibited CHIKV infection. Furthermore, affinity purification-mass spectrometry studies revealed that SK2 associates with a number of proteins involved in cellular gene expression specifically during viral infection, suggesting a role in replication. Collectively these results identify SK2 as a novel CHIKV host factor.

  12. Breeding matters: Natal experience influences population state-dependent host acceptance by an eruptive insect herbivore

    Science.gov (United States)

    2017-01-01

    Eruptive forest insects are highly influential agents of change in forest ecosystems, and their effects have increased with recent climate change. State-dependent life histories contribute significantly to the population dynamics of eruptive forest insect herbivores; however, the proximate mechanisms by which these species shift between states is poorly understood. Laboratory bioassays were conducted using the mountain pine beetle (Dendroctonus ponderosae) to determine the effect of maternal host selection on offspring host preferences, as they apply to population state-dependent behaviors. Female mountain pine beetles exhibited state-dependent preference for artificial host material amended with monoterpenes in the absence of other cues, such that individuals reared in high-density epidemic-state simulations rejected low monoterpene conditions, while low-density endemic-state beetles accepted low monoterpene conditions. State-specific behavior in offspring was dependent on rearing conditions, as a function of maternal host selection, and these effects were observed within one generation. Density-dependent host selection behaviors exhibited by female mountain pine beetle offspring is reinforced by context-dependent maternal effects arising from parental host selection, and in situ exposure to conspecifics. These results demonstrate potential proximate mechanisms that control population dynamics in eruptive forest insects, and will allow for more accurate predictions of continued impact and spread of these species. PMID:28207862

  13. Caenorhabditis elegans-based screen identifies Salmonella virulence factors required for conserved host-pathogen interactions.

    Science.gov (United States)

    Tenor, Jennifer L; McCormick, Beth A; Ausubel, Frederick M; Aballay, Alejandro

    2004-06-01

    A Caenorhabditis elegans-Salmonella enterica host-pathogen model was used to identify both novel and previously known S. enterica virulence factors (HilA, HilD, InvH, SptP, RhuM, Spi4-F, PipA, VsdA, RepC, Sb25, RfaL, GmhA, LeuO, CstA, and RecC), including several related to the type III secretion system (TTSS) encoded in Salmonella pathogenicity island 1 (SPI-1). Mutants corresponding to presumptive novel virulence-related genes exhibited diminished ability to invade epithelial cells and/or to induce polymorphonuclear leukocyte migration in a tissue culture model of mammalian enteropathogenesis. When expressed in C. elegans intestinal cells, the S. enterica TTSS-exported effector protein SptP inhibited a conserved p38 MAPK signaling pathway and suppressed the diminished pathogenicity phenotype of an S. enterica sptP mutant. These results show that C. elegans is an attractive model to study the interaction between Salmonella effector proteins and components of the innate immune response, in part because there is a remarkable overlap between Salmonella virulence factors required for human and nematode pathogenesis.

  14. Integration host factor of Mycobacterium tuberculosis, mIHF, compacts DNA by a bending mechanism.

    Directory of Open Access Journals (Sweden)

    Arpit Mishra

    Full Text Available The bacterial chromosomal DNA is folded into a compact structure called as 'nucleoid' so that the bacterial genome can be accommodated inside the cell. The shape and size of the nucleoid are determined by several factors including DNA supercoiling, macromolecular crowding and nucleoid associated proteins (NAPs. NAPs bind to different sites of the genome in sequence specific or non-sequence specific manner and play an important role in DNA compaction as well as regulation. Until recently, few NAPs have been discovered in mycobacteria owing to poor sequence similarities with other histone-like proteins of eubacteria. Several putative NAPs have now been identified in Mycobacteria on the basis of enriched basic residues or histone-like "PAKK" motifs. Here, we investigate mycobacterial Integration Host Factor (mIHF for its architectural roles as a NAP using atomic force microscopy and DNA compaction experiments. We demonstrate that mIHF binds DNA in a non-sequence specific manner and compacts it by a DNA bending mechanism. AFM experiments also indicate a dual architectural role for mIHF in DNA compaction as well as relaxation. These results suggest a convergent evolution in the mechanism of E. coli and mycobacterial IHF in DNA compaction.

  15. Emergency department crowding: Factors influencing flow

    NARCIS (Netherlands)

    van der Linden, M.C.

    2015-01-01

    This thesis focuses on emergency department (ED) crowding. In the first part (ED crowding in the Netherlands) the current state of EDs regarding patients’ length of stay and ED managers’ experiences of crowding are described. Part two (input factors) contains three studies which describe the case lo

  16. A review of factors influencing the incidence and severity of plaque-induced gingivitis.

    Science.gov (United States)

    Trombelli, L; Farina, R

    2013-06-01

    An individual variation in the gingival inflammatory response to the dental biofilm has been demonstrated. This variability can be observed between individuals with neither quantitative nor qualitative differences in plaque accumulation. The reported significant differences in gingival inflammatory response under quantitatively and/or qualitatively almost identical bacterial challenge suggest that the gingival response to plaque accumulation may be an individual trait, possibly genetic in origin. The most recent classification of periodontal diseases acknowledges that the clinical expression of plaque-induced gingival inflammation can be substantially modified by systemic factors, either inherent to the host or related to environmental influences. The aim of the present literature review is to describe (i) the factors influencing the development of plaque-induced gingivitis as well as (ii) those metabolic, environmental and systemic factors which have a direct impact on the etiopathogenetic pathway of plaque-induced gingivitis, thus altering the nature or course of the gingival inflammatory response to dental biofilm.

  17. Influence of Host-Plant Surface Chemicals on the Oviposition of the Cereal Stemborer Busseola Fusca.

    Science.gov (United States)

    Juma, Gerald; Clément, Gilles; Ahuya, Peter; Hassanali, Ahmed; Derridj, Sylvie; Gaertner, Cyrile; Linard, Romain; Le Ru, Bruno; Frérot, Brigitte; Calatayud, Paul-André

    2016-05-01

    The chemical composition of plant surfaces plays a role in selection of host plants by herbivorous insects. Once the insect reaches the plant, these cues determine host acceptance. Laboratory studies have shown that the stem borer Busseola fusca (Lepidoptera: Noctuidae), an important pest of sorghum and maize in sub-Saharan Africa, is able to differentiate between host and non-host plant species. However, no information is available on the cues used by this insect to seek and accept the host plant. Thus, the role of surface phytochemical stimuli on host selection and oviposition by B. fusca was studied in the laboratory using two host plants, sorghum, Sorghum bicolor, and maize, Zea mays, and one non-host plant, Napier grass, Pennisetum purpureum. The numbers of eggs and egg masses deposited on the three plant species were compared first under no-choice and choice conditions. In both cases, more eggs and egg masses were laid on maize and sorghum than on the non-host. Artificial surrogate stems treated with a water or chloroform surface extract of each plant were then compared with surrogate stems treated with, respectively, water or chloroform as controls, under similar conditions. Surrogate stems treated with plant water extracts did not show an increase in oviposition when compared to controls, indicating that the major compounds in these extracts, i.e., simple sugars and free amino acids, are not significantly responsible for the oviposition preference. By contrast, a chloroform extract of sorghum enhanced oviposition on the surrogate stems compared to the control, while those of maize and Napier grass showed no significant effects. Analysis of the chloroform extract of sorghum showed higher amounts of α-amyrin, ß-amyrin, and n-nonacosane compared to those of maize and Napier grass. A blend of the three chemicals significantly increased oviposition compared to the chloroform-treated control, indicating that these compounds are part of the surface chemical

  18. [Factors that influence student ratings of instruction].

    Science.gov (United States)

    Chae, Su Jin; Choung, Yun Hoon; Chung, Yoon Sok

    2015-03-01

    The purpose of this study was to examine the validity of student ratings of instruction by analyzing their relationships with several variables, including gender, academic rank, specialty, teaching time, and teaching method, at a medical school. This study analyzed the student ratings of 297 courses at Ajou University School of Medicine in 2013. SPSS version 12.0 was used to analyze the data and statistics by t-test, analysis of variance, and Scheffe test. There were no statistically significant differences in student ratings between gender, rank, and specialty. However, student ratings were significantly influenced by teaching times and methods (pStudent ratings were high for teaching times of 10 hours or more and small-group learning, compared with lectures. There was relatively mean differences in students ratings by teaching times, specialty and rank, although the difference in ratings was not statistically significant. Student ratings can be classified by teaching time and method for summative purposes. To apply student ratings to the evaluation of the performance of faculty, further studies are needed to analyze the variables that influence student ratings.

  19. Propionibacterium acnes CAMP factor and host acid sphingomyelinase contribute to bacterial virulence: potential targets for inflammatory acne treatment.

    Directory of Open Access Journals (Sweden)

    Teruaki Nakatsuji

    Full Text Available BACKGROUND: In the progression of acne vulgaris, the disruption of follicular epithelia by an over-growth of Propionibacterium acnes (P. acnes permits the bacteria to spread and become in contact with various skin and immune cells. METHODOLOGY/PRINCIPAL FINDINGS: We have demonstrated in the present study that the Christie, Atkins, Munch-Peterson (CAMP factor of P. acnes is a secretory protein with co-hemolytic activity with sphingomyelinase that can confer cytotoxicity to HaCaT keratinocytes and RAW264.7 macrophages. The CAMP factor from bacteria and acid sphingomyelinase (ASMase from the host cells were simultaneously present in the culture supernatant only when the cells were co-cultured with P. acnes. Either anti-CAMP factor serum or desipramine, a selective ASMase inhibitor, significantly abrogated the P. acnes-induced cell death of HaCaT and RAW264.7 cells. Intradermal injection of ICR mouse ears with live P. acnes induced considerable ear inflammation, macrophage infiltration, and an increase in cellular soluble ASMase. Suppression of ASMase by systemic treatment with desipramine significantly reduced inflammatory reaction induced by intradermal injection with P. acnes, suggesting the contribution of host ASMase in P. acnes-induced inflammatory reaction in vivo. Vaccination of mice with CAMP factor elicited a protective immunity against P. acnes-induced ear inflammation, indicating the involvement of CAMP factor in P. acnes-induced inflammation. Most notably, suppression of both bacterial CAMP factor and host ASMase using vaccination and specific antibody injection, respectively, cooperatively alleviated P. acnes-induced inflammation. CONCLUSIONS/SIGNIFICANCE: These findings envision a novel infectious mechanism by which P. acnes CAMP factor may hijack host ASMase to amplify bacterial virulence to degrade and invade host cells. This work has identified both CAMP factor and ASMase as potential molecular targets for the development of drugs

  20. Factors influencing women's attitudes towards midwifery: Tool validation.

    Science.gov (United States)

    Al-Rajabi, Omaymah; Al-Hadid, Lourance; Subih, Maha

    2015-10-01

    The purpose of this study was to validate a tool that explores the factors influencing women's opinion of and attitudes towards midwifery. A descriptive, cross-sectional design was used. The sample consisted of 526 Jordanian women. Cluster sampling was used to ensure a representative sample; then, convenience sampling was performed. The instrument asked non-identifying demographic questions and covered factors reported in literature to influence women's attitudes towards and views of the profession. The resulting instrument consisted of five factors explained by 29 items. These factors were women's general view of midwives, midwife duties, professional ethics, media influence and demotivating factors associated with working as a midwife. Although the instrument is valid and reliable, it needs further testing in other studies. Taking the factors reported on by the present study into account in public policy-making could promote better understanding of midwifery and improve its status in the community. © 2014 Wiley Publishing Asia Pty Ltd.

  1. Factors influencing medication label viewing in Malaysia.

    Science.gov (United States)

    Cheah, Yong Kang; Chong, Yen Wan

    2016-07-12

    The misuse of medicine is a serious public health issue worldwide. An important factor that contributes to the misuse of medicine is the lack of medication label viewing by consumers. The objective of the present study is to examine the socio-economic, demographic and lifestyle factors associated with medication label viewing among Malaysian adults. The empirical analysis is based on a nationally representative data set of 30,992 respondents. An ordered probit model is used to examine different types of medication label viewers. The results of this study suggest that socio-economic (i.e. age, income level, education level, location of residence), demographic (i.e. gender, ethnicity, marital status) and lifestyle factors (i.e. physical activity, smoking) have significant effects on medication label viewing. It is found that age, low-income and low-education level reduce the likelihood of viewing medication label. Based on these findings, several policy implications are suggested. The present study provides policy makers with baseline information regarding which cohorts of individuals to focus on in efforts to increase the frequency of medication label viewing.

  2. Factors influencing early survival after liver transplantation.

    Science.gov (United States)

    Stock, P G; Estrin, J A; Fryd, D S; Payne, W D; Belani, K G; Elick, B A; Najarian, J S; Ascher, N L

    1989-02-01

    The purpose of this study was to analyze data from all adult and pediatric liver transplants performed between January 1, 1983 and January 15, 1986 at the University of Minnesota Hospital and identify perioperative variables that predict patient survival and could aid in patient selection. Charts, intraoperative anesthesia records, blood bank records, flow sheets, outpatient records, and autopsy reports were examined in 45 pediatric and 15 adult patients who underwent primary orthotopic liver transplantation. Analysis of the data can be summarized as follows: (1) Pediatric patients whose coagulation parameters could not be corrected prior to operation and who consequently required preoperative exchange transfusion had poorer outcomes than those not requiring an exchange to correct coagulation parameters. (2) The rapid infusion technique for massive blood transfusion resulted in significantly decreased blood loss and intraoperative blood product replacement. (3) Twenty-four hour postoperative factor V levels were good predictors of survival. Patients with poor factor V levels required rigorous replacement of coagulation factors. (4) Pediatric patients with uncorrectable coagulopathies requiring immediate postoperative exchange transfusion had extremely high mortality.

  3. Factors influencing recognition of interrupted speech.

    Science.gov (United States)

    Wang, Xin; Humes, Larry E

    2010-10-01

    This study examined the effect of interruption parameters (e.g., interruption rate, on-duration and proportion), linguistic factors, and other general factors, on the recognition of interrupted consonant-vowel-consonant (CVC) words in quiet. Sixty-two young adults with normal-hearing were randomly assigned to one of three test groups, "male65," "female65" and "male85," that differed in talker (male/female) and presentation level (65/85 dB SPL), with about 20 subjects per group. A total of 13 stimulus conditions, representing different interruption patterns within the words (i.e., various combinations of three interruption parameters), in combination with two values (easy and hard) of lexical difficulty were examined (i.e., 13×2=26 test conditions) within each group. Results showed that, overall, the proportion of speech and lexical difficulty had major effects on the integration and recognition of interrupted CVC words, while the other variables had small effects. Interactions between interruption parameters and linguistic factors were observed: to reach the same degree of word-recognition performance, less acoustic information was required for lexically easy words than hard words. Implications of the findings of the current study for models of the temporal integration of speech are discussed.

  4. Clinically important factors influencing endothelial function.

    Science.gov (United States)

    Vapaatalo, H; Mervaala, E

    2001-01-01

    The endothelium, a continuous cellular monolayer lining the blood vessels, has an enormous range of important homeostatic roles. It serves and participates in highly active metabolic and regulatory functions including control of primary hemostasis, blood coagulation and fibrinolysis, platelet and leukocyte interactions with the vessel wall, interaction with lipoprotein metabolism, presentation of histocompatibility antigens, regulation of vascular tone and growth and further of blood pressure. Many crucial vasoactive endogenous compounds like prostacyclin, thromboxane, nitric oxide, endothelin, angiotensin, endothelium derived hyperpolarizing factor, free radicals and bradykinin are formed in the endothelial cells to control the functions of vascular smooth muscle cells and of circulating blood cells. These versatile and complex systems and cellular interactions are extremely vulnerable. The balances may be disturbed by numerous endogenous and exogenous factors including psychological and physical stress, disease states characterized by vasospasm, inflammation, leukocyte and platelet adhesion and aggregation, thrombosis, abnormal vascular proliferation, atherosclerosis and hypertension. The endothelial cells are also the site of action of many drugs and exogenous toxic substances (e.g. smoking, alcohol). As markers and assays for endothelial dysfunction, direct measurement of nitric oxide, its metabolites from plasma and urine, functional measurement of vascular nitric oxide dependent responses and assay of different circulating markers have been used. In numerous pathological conditions (e.g. atherosclerosis, hypertension, congestive heart failure, hyperhomocysteinemia, diabetes, renal failure, transplantation, liver cirrhosis) endothelial dysfunction has been described to exist. Some of them, as well as hormonal and nutritional factors and drug treatment will be discussed in this short review.

  5. Ecological factors driving the long-term evolution of influenza's host range

    Science.gov (United States)

    Cobey, Sarah; Pascual, Mercedes; Dieckmann, Ulf

    2010-01-01

    The evolution of a pathogen's host range is shaped by the ecology of its hosts and by the physiological traits that determine host specificity. For many pathogen traits, there is a trade-off: a phenotype suitable for infecting one set of hosts poorly infects another. Introducing and analysing a simple evo-epidemiological model, here we study how such a trade-off is expected to affect evolution of the host ranges of influenza viruses. We examine a quantitative trait underlying host specificity, given by an influenza virus's degree of adaptation to certain conformations of sialic acid receptors, and investigate how this receptor preference evolves in a minimal network of host species, including humans, that differ in life history and receptor physiology. Using adaptive dynamics theory, we establish thresholds in interspecific transmission rates and host population sizes that govern the emergence and persistence of human-adapted viruses. These ecological thresholds turn out to be largely independent of the strength of the evolutionary trade-off, underscoring the importance of ecological conditions in determining a disease's host range. PMID:20444714

  6. Factors Influencing the Performance of Coal Briquettes

    Directory of Open Access Journals (Sweden)

    Unsia HABIB

    2014-01-01

    Full Text Available The continuous supply of energy resources is essential for the development of any nation. The economic and social life of any nation depends enormously on the energy resources. Over the past few years the energy crisis is becoming a major issue in developing countries as Pakistan. Oil, Natural gas and hydro are the three major energy resources of the Pakistan. These conventional energy resources were being exploited in the past leading to an issue of energy crisis in the country. Replacing expensive imported energy resources with coal briquettes made from indigenous coal reserves can provide fuel for the local residential and commercial markets. Coal briquettes formation is a process to convert coal powder into a specific shape with the help of a binder. An external force is applied to the coal binder mixture to make a firm body of desired shape. The briquettes formed this way will not disintegrate under normal conditions of transportation and use. Coal briquettes are preferred over raw coal because they are a smokeless, strong and low emissive fuel that can be used in numerous domestic and commercial applications. The performance of coal briquettes formed is dependent largely upon its thermal properties and the mechanical strength. Nowadays an environmentally safe briquettes formation process is also included in the performance criteria of coal briquettes. The mechanical strength of coal briquettes affects its storage and transportation to the intended market. The studies on coal briquettes show that coal briquettes quality depends on many factors like the type of binder, quantity of binder, grade of coal, moisture level, coal particle size and its distribution etc. These factors along with some of the factors as time of compaction, compaction temperature, and compaction pressure and moisture level are discussed in this paper to evaluate the performance of briquetting technology in future.

  7. Organizational Culture Factors that Can Influence Knowledge Transfer

    Directory of Open Access Journals (Sweden)

    Ioan Pastor

    2011-05-01

    Full Text Available The paper tries to establish the correlation that exists between the types of organizational culture and the factors that influence knowledge transfer. We started from the hypothesis that organizations which have high scores for cultural factors of openness to change and innovation as well as for task-oriented organizational growth will have the tendency of being favourable to knowledge transfer. Moreover, we started from the hypothesis that organizations that have high scores for bureaucracy and competition factors will have the tendency of being unfavourable to knowledge transfer. The research reached the conclusion that there seems to be a correlation between organizational culture and the factors that influence knowledge transfer.

  8. M062 is a host range factor essential for myxoma virus pathogenesis and functions as an antagonist of host SAMD9 in human cells.

    Science.gov (United States)

    Liu, Jia; Wennier, Sonia; Zhang, Leiliang; McFadden, Grant

    2011-04-01

    Myxoma virus (MYXV) M062R is a functional homolog of the C7L family of host range genes from orthopoxviruses. We constructed a targeted M062R-knockout-MYXV (vMyxM062-KO) and characterized its properties in vitro and in vivo. In European rabbits, infection by vMyxM062-KO was completely asymptomatic. The surviving rabbits did not gain full protection against the subsequent lethal-dose challenge with wild-type MYXV. We also looked for cellular tropism defects in a variety of cultured cells. In all of the rabbit cells tested, vMyxM062-KO conducts an abortive infection, although it initiates viral DNA replication. In many, but not all, human cancer cells that are permissive for wild-type MYXV, vMyxM062-KO exhibited a profound replication defect. We categorized human cells tested into two groups: (i) type A, which support productive replication for wild-type MYXV but are unable to produce significant levels of progeny virus by vMyxM062-KO, and (ii) type B, which are permissive to infections by both wild-type MYXV and vMyxM062-KO. Furthermore, using proteomic strategies, we identified sterile α motif domain containing 9 (SAMD9), an interferon-regulated cellular protein implicated in human inflammatory disorders, as a unique host binding partner of M062 in human cells. Significantly, knocking down SAMD9 in type A human cancer cells led to a substantial rescue of vMyxM062-KO infection. In summary, M062 is a novel host range factor that controls productive MYXV replication in rabbit cells and in a wide variety of human cells. M062 also binds and antagonizes cellular SAMD9 in human cells, suggesting that SAMD9 is a novel innate antiviral factor against poxviruses.

  9. Factors influencing condom use among Nigerian undergraduates: A ...

    African Journals Online (AJOL)

    Factors influencing condom use among Nigerian undergraduates: A mixed method study. ... PROMOTING ACCESS TO AFRICAN RESEARCH ... group discussions) and quantitative (cross-sectional survey) methods were utilised for this study.

  10. Social and economic factors influencing the patronage and use of ...

    African Journals Online (AJOL)

    Social and economic factors influencing the patronage and use of complementary and alternative medicine in Enugu. ... Journal of Pharmacy & Bioresources ... approaches to medical treatment that are outside of mainstream medical training.

  11. Personal and Socio-Economic Factors Influencing Female Choice of ...

    African Journals Online (AJOL)

    Personal and Socio-Economic Factors Influencing Female Choice of Courses in ... Female students in six (Arts, Education, Pharmacy, Science, Social Sciences and ... services to secondary school students in the choice of courses and career.

  12. Factors Influencing the Development of Practical Skills of Interns ...

    African Journals Online (AJOL)

    Factors Influencing the Development of Practical Skills of Interns Working in ... It starts with a good theoretical preparation and some practical experience at university. ... The relationship between intern and senior doctor was important when it ...

  13. Factors influencing the job satisfaction of academics in higher ...

    African Journals Online (AJOL)

    Factors influencing the job satisfaction of academics in higher education. ... 94 respondents from similar departments at a residential and a distance education institution. A questionnaire focused on teaching, research, community service, ...

  14. Assessment of risk factors that influence pregnancy outcomes in ...

    African Journals Online (AJOL)

    Keywords: Pregnancy outcome, low birth weight, Apgar score, maternal age, Tanzania ... (2006) reported that, several risk factors influence neonatal mortality. ..... which is the lowest cut off point for the classification of normal blood pressure.

  15. 'Mum never loved me.' How structural factors influence adolescent ...

    African Journals Online (AJOL)

    How structural factors influence adolescent sexual and reproductive health ... Research in high income countries shows parent–child connectedness to be ... to young people's low self-esteem and risky sexual behaviour while unplanned ...

  16. Analysis of Socio-Economic Factors Influencing Farmers' Adoption ...

    African Journals Online (AJOL)

    Analysis of Socio-Economic Factors Influencing Farmers' Adoption of Rice ... Farming experience, household size, farm size and extension contact ... gender, market availability, education, extension contact, labour availability and farm size.

  17. Factors Influencing Farmer Output in the International Fund for ...

    African Journals Online (AJOL)

    kim

    Department of Rural Sociology and Extension. Michael Okpara ... This study analysed factors influencing International Fund for Agricultural. Development ..... farmers (50.9%) acquired secondary education as against Cross River IFAD farmers.

  18. Factors Influencing the Consumption of Pulses in Rural and Urban ...

    African Journals Online (AJOL)

    Factors Influencing the Consumption of Pulses in Rural and Urban Areas of Tanzania. ... Model results revealed that household sizes and education levels of the ... To increase the market share of pulses, traders should devise effective ...

  19. Characteristics and factors influencing fast food intake of young ...

    African Journals Online (AJOL)

    Characteristics and factors influencing fast food intake of young adult consumers in Johannesburg, South Africa. ... their reasons for and frequency of fast food consumption, their specific fast food choices, and their attitudes towards health.

  20. LITERATURE REVIEW ON FACTORS INFLUENCING MILK PURCHASE BEHAVIOUR

    National Research Council Canada - National Science Library

    Klaudia Kurajdova; Janka Taborecka-Petrovicova

    2015-01-01

    In today’s highly informed, competitive and saturated market, a key to success of any business depends on knowing consumer and his consumption patterns and recognizing and understanding factors influencing...

  1. Socio-Demographic Factors Influencing Work-Role Salience Among ...

    African Journals Online (AJOL)

    Socio-Demographic Factors Influencing Work-Role Salience Among ... The findings showed that students from lower socio-economic status homes and those ... The need to involve the students\\' parents in career education programmes and ...

  2. Factors Influencing Food Choice in the Elderly Mauritian Population

    African Journals Online (AJOL)

    admpather

    Only the factor of taste influencing food choice was significantly different between the two ..... available through the media, promotions, and advertising may confuse consumers and cause ... Predictors of self-initiated, healthful dietary change.

  3. Factors Influencing the Consumption of Pulses in Rural and Urban ...

    African Journals Online (AJOL)

    factors that influenced the extent of consumption in urban areas. In summary, the model .... model to control for self-selection bias because some potential consumers may ... accommodate consumer's zero value of purchase as an outcome of a ...

  4. Factors influencing eating attitudes in secondary-school girls in ...

    African Journals Online (AJOL)

    Factors influencing eating attitudes in secondary-school girls in South Africa - a preliminary stud. ... PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN JOURNALS ONLINE (AJOL) ... South African Medical Journal. Journal Home ...

  5. Factors influencing utilization of Natural Family Planning among ...

    African Journals Online (AJOL)

    Factors influencing utilization of Natural Family Planning among Child Bearing Women in Chilonga ... Medical Journal of Zambia ... The literature review was mainly obtained from studies conducted globally, regionally and Zambia inclusively.

  6. Factors influencing choice of paediatrics as a career among medical ...

    African Journals Online (AJOL)

    female students (30%) considered gender distribution to be a factor influencing their career choice (p=0.046). ... role models in the specialty, job opportunities and financial .... of non-responder bias, although the relatively high response.

  7. Prevalence Of Early Childhood Malnutrition And Influencing Factors ...

    African Journals Online (AJOL)

    therefore, to asses the prevalence of malnutrition and the factors influencing the ... childhood malnutrition in Kabarole District and other areas in Uganda, and ..... Jitta JJ, Migadde M and J Mudusu Determinants of Malnutrition in under-fives.

  8. INFLUENCING FACTORS OF PRICE AND ASSOCIATED STRATEGIES

    OpenAIRE

    Liviu NEAMTU; NEAMTU Adina Claudia

    2012-01-01

    The price is an important element in product position; it is a means of sending signals to consumers about the nature and quality of the product. When, for a certain business environment, the demand curve is known in relation to market (competition) costs and prices, the firm can choose a pricing policy simultaneously with business strategy. This study synthesizes the key-factors occurring in choosing a business strategy and the game of price and cost on the market As an approach to pricing p...

  9. Emotional Factors Influencing Students’ English Writing Competence

    Institute of Scientific and Technical Information of China (English)

    聂勇伟

    2015-01-01

    As an international common language,English becomes more and more important.Students try their best to improve their English writing competence,especially as the social’s requirements for their English writing become higher and higher.However,students’English writing is very poor,fewer and fewer of them can write fluent English.Through the study of this topic,the author hopes it can remove students’emotional obstacles of English writing learning,master the direction of emotional factor,arouse students’interesting in learning oral English,make them practice English writing positively and obtain a better teaching effect

  10. Treatment Factors That Influence Mortality in Acromegaly.

    Science.gov (United States)

    McCabe, John; Ayuk, John; Sherlock, Mark

    2016-01-01

    Acromegaly is a rare condition characterized by excessive secretion of growth hormone (GH), which is almost always due to a pituitary adenoma. Acromegaly is associated with significant morbidity such as hypertension, type 2 diabetes, cardiomyopathy, obstructive sleep apnoea, malignancy and musculoskeletal abnormalities. Acromegaly has also been associated with increased mortality in several retrospective studies. This review will focus on the epidemiological data relating to mortality rates in acromegaly, the relationship between acromegaly and malignancy, the role of GH and insulin-like growth factor-I in assessing the risk of future mortality, and the impact of radiotherapy and hypopituitarism on mortality.

  11. Factors influencing consumer satisfaction with health care.

    Science.gov (United States)

    Deshpande, Satish P; Deshpande, Samir S

    2014-01-01

    The purpose of this study was to examine factors that impact consumer satisfaction with health care. This is a secondary analysis of the Center for Studying Health System Change's 2010 Health Tracking Household Survey. Regression analysis was used to examine the impact of treatment issues, financial issues, family-related issues, sources of health care information, location, and demographics-related factors on satisfaction with health care. The study involved 12280 subjects, 56% of whom were very satisfied with their health care, whereas 66% were very satisfied with their primary care physician. Fourteen percent of the subjects had no health insurance; 34% of the subjects got their health care information from the Web. Satisfaction with primary care physician, general health status, promptness of visit to doctor, insurance type, medical cost per family, annual income, persons in family, health care information from friends, and age significantly impacted satisfaction with health care. The regression models accounted for 23% of the variance in health care satisfaction. Satisfaction with primary care physicians, health insurance, and general health status are the 3 most significant indicators of an individual's satisfaction with health care.

  12. Factors influencing the intention to watch online video advertising.

    Science.gov (United States)

    Lee, Joonghwa; Lee, Mira

    2011-10-01

    This study examines the factors influencing consumer intention to watch online video ads, by applying the theory of reasoned action. The attitude toward watching online video ads, the subjective norm, and prior frequency of watching online video ads positively influence the intention to watch online video ads. Further, beliefs held about entertainment and information outcomes from watching online video ads and subjective norm influence attitude toward watching these ads.

  13. A study of the factors influencing school-going students considering medical careers.

    LENUS (Irish Health Repository)

    McHugh, S M

    2012-02-01

    INTRODUCTION: Obtaining a place in an Irish medical school is extremely competitive, a situation mirrored in many other countries. We aimed to determine the factors influencing school students in deciding to study medicine in university. We further determined what level of interest exists in pursuing a surgical career after completion of medical school. METHODS: The Royal College of Surgeons in Ireland hosts an annual "Introduction to Medicine" programme for senior school children. Attendees were surveyed using a Likert scale to examine the factors influencing the group in choosing to study medicine, and pursue surgery as their ultimate career choice. RESULTS: A total of 128 completed the survey, giving a response rate of 100%. The opportunity to help others was most the most influential factors cited by students (97%). Males were significantly more likely to have an interest in a career in surgery rather than medicine (p = 0.003), and ranked "financial reward" (p = 0.036) as a more significant factors in influencing career choice than did females. CONCLUSIONS: A clear understanding of these factors influencing our students in their career choices and a strategy of recruitment based on these is imperative in order to optimize recruitment of students most suited to working as doctors.

  14. FACTORS INFLUENCING BRAND EQUITY OF BALI AS A TOURISM DESTINATION

    OpenAIRE

    I Ketut Surya Diarta; I Gde Pitana; Nyoman Darma Putra; Agung Suryawan Wiranatha

    2016-01-01

    Globally, competition among tourism destinations is more stringent in getting foreign tourists, including Bali. One effort to win the competition is increasing destination brand equity through maintaining its influencing factors and gaining tourist positive behavior toward destination. This effort, in long run, will increase and stabilize destination revenue and sustainability. This research aims to analyze factors influencing brand equity of Bali as a tourism destination. This research was c...

  15. Factors Influencing the Disabled's Employment in the Competitive Labour Market.

    Science.gov (United States)

    Mannila, Simo

    1995-01-01

    Factors influencing the job search outcomes of 1,353 Finnish individuals with disabilities were studied, focusing on age, gender, domicile, basic education, vocational training, and type of disability. Results showed that age, education, and domicile influenced outcomes, and labor market status was to some extent gender specific. (JDD)

  16. STUDY ON FACTORS INFLUENCING INK ABSORPTION OF COATED PAPER

    Institute of Scientific and Technical Information of China (English)

    Yanxin Liu; Chuanshan Zhao; Shuxia Shang; Zhongwei Sun

    2004-01-01

    Ink absorption is one of the most important factors which influence printing properties. This article had discussed the influence of coating properties,technologies of heating and pressure etc. on ink absorption and showed that ink absorption can be adjusted and coating surface structure can be improved when technologies of heating and pressure change, pigment and adhesive altered.

  17. Linguistic Factors Influencing Speech Audiometric Assessment.

    Science.gov (United States)

    Coene, Martine; Krijger, Stefanie; Meeuws, Matthias; De Ceulaer, Geert; Govaerts, Paul J

    2016-01-01

    In speech audiometric testing, hearing performance is typically measured by calculating the number of correct repetitions of a speech stimulus. We investigate to what extent the repetition accuracy of Dutch speech stimuli presented against a background noise is influenced by nonauditory processes. We show that variation in verbal repetition accuracy is partially explained by morpholexical and syntactic features of the target language. Verbs, prepositions, conjunctions, determiners, and pronouns yield significantly lower correct repetitions than nouns, adjectives, or adverbs. The reduced repetition performance for verbs and function words is probably best explained by the similarities in the perceptual nature of verbal morphology and function words in Dutch. For sentences, an overall negative effect of syntactic complexity on speech repetition accuracy was found. The lowest number of correct repetitions was obtained with passive sentences, reflecting the cognitive cost of processing a noncanonical sentence structure. Taken together, these findings may have important implications for the audiological practice. In combination with hearing loss, linguistic complexity may increase the cognitive demands to process sentences in noise, leading to suboptimal functional hearing in day-to-day listening situations. Using test sentences with varying degrees of syntactic complexity may therefore provide useful information to measure functional hearing benefits.

  18. Physical factors influence for biologic systems

    Science.gov (United States)

    Piruzyan, L. A.

    2005-08-01

    Physical methods are widely spread in diagnostics and therapy of different pathologies, especially in oncology. The application of lasers occurred to be the perspective approach for combined methods application in medicine. Our work is devoted to investigation of thermal effect of focused laser beam in the model of Garding-Passi melanoma and also to the study of free radicals activity after the radiation with non-focused laser beam. The histologic alterations correlated with theoretical calculations of temperature distribution in irradiated tissue for energies 30-60 J attracted our interest. The values of maximal temperatures in depths of tissue for energies 30-60 J were carried out. In the model of permanent magnetic field (PMF) effect for mice ascites sarcoma 37 we have showed the linear dependence of tumor growth inhibition from the period of PMF treatment. Simultaneously we investigated PMF influence for free radical"s (FR) concentrations in mice organs and tissues and potentially appearing questions of PMF effect for biopotential in connection with FR formation. We have also studied the alterations of K, Na and Ca ions concentrations in ascetic fluids after animal"s PMF treatment. We revealed some reasons of biopotential generation and concluded that biopotential is not the result of specific ions gradient only but its generation can be followed by free radicals states appearance and occurrence of semi-conductivity in biostructures.

  19. Host heterogeneity influences the impact of a non-native disease invasion on populations of a foundation tree species

    Science.gov (United States)

    Jules, Erik S.; Carroll, Allyson L.; Garcia, Andrea M.; Steenbock, Christopher M.; Kauffman, Matthew J.

    2014-01-01

    Invasive pathogens are becoming increasingly important in forested ecosystems, yet they are often difficult to study because of their rapid transmission. The rate and extent of pathogen spread are thought to be partially controlled by variation in host characteristics, such as when host size and location influence susceptibility. Few host-pathogen systems, however, have been used to test this prediction. We used Port Orford cedar (Chamaecyparis lawsoniana), a foundation tree species in riparian areas of California and Oregon (USA), and the invasive oomycete Phytophthora lateralis to assess pathogen impacts and the role of host characteristics on invasion. Across three streams that had been infected for 13–18 years by P. lateralis, we mapped 2241 trees and determined whether they had been infected using dendrochronology. The infection probability of trees was governed by host size (diameter at breast height [DBH]) and geomorphic position (e.g., active channel, stream bank, floodplain, etc.) similarly across streams. For instance, only 23% of trees DBH were infected, while 69% of trees ≥20 cm DBH were infected. Presumably, because spores of P. lateralis are transported downstream in water, they are more likely to encounter well-developed root systems of larger trees. Also because of this water-transport of spores, differences in infection probability were found across the geomorphic positions: 59% of cedar in the active channel and the stream bank (combined) were infected, while 23% of trees found on higher geomorphic types were infected. Overall, 32% of cedar had been infected across the three streams. However, 63% of the total cedar basal area had been killed, because the greatest number of trees, and the largest trees, were found in the most susceptible positions. In the active channel and stream bank, 91% of the basal area was infected, while 46% was infected across higher geomorphic positions. The invasion of Port Orford cedar populations by

  20. Temporal SILAC-based quantitative proteomics identifies host factors involved in chikungunya virus replication.

    Science.gov (United States)

    Treffers, Emmely E; Tas, Ali; Scholte, Florine E M; Van, Myrthe N; Heemskerk, Matthias T; de Ru, Arnoud H; Snijder, Eric J; van Hemert, Martijn J; van Veelen, Peter A

    2015-07-01

    Chikungunya virus (CHIKV) is an arthropod-borne reemerging human pathogen that generally causes a severe persisting arthritis. Since 2005, the virus has infected millions of people during outbreaks in Africa, Indian Ocean Islands, Asia, and South/Central America. Many steps of the replication and expression of CHIKV's 12-kb RNA genome are highly dependent on cellular factors, which thus constitute potential therapeutic targets. SILAC and LC-MS/MS were used to define the temporal dynamics of the cellular response to infection. Using samples harvested at 8, 10, and 12 h postinfection, over 4700 proteins were identified and per time point 2800-3500 proteins could be quantified in both biological replicates. At 8, 10, and 12 h postinfection, 13, 38, and 106 proteins, respectively, were differentially expressed. The majority of these proteins showed decreased abundance. Most subunits of the RNA polymerase II complex were progressively degraded, which likely contributes to the transcriptional host shut-off observed during CHIKV infection. Overexpression of four proteins that were significantly downregulated (Rho family GTPase 3 (Rnd3), DEAD box helicase 56 (DDX56), polo-like kinase 1 (Plk1), and ubiquitin-conjugating enzyme E2C (UbcH10) reduced susceptibility of cells to CHIKV infection, suggesting that infection-induced downregulation of these proteins is beneficial for CHIKV replication. All MS data have been deposited in the ProteomeXchange with identifier PXD001330 (http://proteomecentral.proteomexchange.org/dataset/PXD001330).

  1. The contribution of tumor and host tissue factor expression to oncogene-driven gliomagenesis.

    Science.gov (United States)

    Magnus, Nathalie; Meehan, Brian; Garnier, Delphine; Hashemi, Maryam; Montermini, Laura; Lee, Tae Hoon; Milsom, Chloe; Pawlinski, Rafal; Ohlfest, John; Anderson, Mark; Mackman, Nigel; Rak, Janusz

    2014-11-14

    Glioblastoma multiforme (GBM) is an aggressive form of glial brain tumors, associated with angiogenesis, thrombosis, and upregulation of tissue factor (TF), the key cellular trigger of coagulation and signaling. Since TF is upregulated by oncogenic mutations occurring in different subsets of human brain tumors we investigated whether TF contributes to tumourigenesis driven by oncogenic activation of EGFR (EGFRvIII) and RAS pathways in the brain. Here we show that TF expression correlates with poor prognosis in glioma, but not in GBM. In situ, the TF protein expression is heterogeneously expressed in adult and pediatric gliomas. GBM cells harboring EGFRvIII (U373vIII) grow aggressively as xenografts in SCID mice and their progression is delayed by administration of monoclonal antibodies blocking coagulant (CNTO 859) and signaling (10H10) effects of TF in vivo. Mice in which TF gene is disrupted in the neuroectodermal lineage exhibit delayed progression of spontaneous brain tumors driven by oncogenic N-ras and SV40 large T antigen (SV40LT) expressed under the control of sleeping beauty transposase. Reduced host TF levels in low-TF/SCID hypomorphic mice mitigated growth of glioma subcutaneously but not in the brain. Thus, we suggest that tumor-associated TF may serve as therapeutic target in the context of oncogene-driven disease progression in a subset of glioma.

  2. A chromosomally encoded virulence factor protects the Lyme disease pathogen against host-adaptive immunity.

    Directory of Open Access Journals (Sweden)

    Xiuli Yang

    2009-03-01

    Full Text Available Borrelia burgdorferi, the bacterial pathogen of Lyme borreliosis, differentially expresses select genes in vivo, likely contributing to microbial persistence and disease. Expression analysis of spirochete genes encoding potential membrane proteins showed that surface-located membrane protein 1 (lmp1 transcripts were expressed at high levels in the infected murine heart, especially during early stages of infection. Mice and humans with diagnosed Lyme borreliosis also developed antibodies against Lmp1. Deletion of lmp1 severely impaired the pathogen's ability to persist in diverse murine tissues including the heart, and to induce disease, which was restored upon chromosomal complementation of the mutant with the lmp1 gene. Lmp1 performs an immune-related rather than a metabolic function, as its deletion did not affect microbial persistence in immunodeficient mice, but significantly decreased spirochete resistance to the borreliacidal effects of anti-B. burgdorferi sera in a complement-independent manner. These data demonstrate the existence of a virulence factor that helps the pathogen evade host-acquired immune defense and establish persistent infection in mammals.

  3. Integration host factor is required for replication of pYGK-derived plasmids in Aggregatibacter actinomycetemcomitans.

    Science.gov (United States)

    Torres-Escobar, Ascención; Juárez-Rodríguez, María D; Demuth, Donald R

    2014-08-01

    In this study, we show that integration host factor protein (IHF) is required for replication of pYGK plasmids in Aggregatibacter actinomycetemcomitans. YGK plasmids were not replicated in A. actinomycetemcomitans strains lacking either the α- or β- subunit of IHF. However, the deletion mutants were complemented, and plasmid replication was restored when the promoter region and gene for either ihfA or ihfB was cloned into pYGK. We also identified two motifs that resemble the consensus IHF-binding site in a 813-bp fragment containing the pYGK origin of replication. Using electrophoretic mobility shift assays, purified IHFα-IHFβ protein complex was shown to bind to probes containing either of these motifs. To our knowledge, this is the first report showing that plasmid replication is IHF-dependent in the family Pasteurellaceae. In addition, using site-direct mutagenesis, the XbaI and KpnI restriction sites in the suicide vector pJT1 were modified to generate plasmid pJT10. The introduction of these new unique sites in pJT10 facilitates the transfer of transcriptional or translational lacZ fusion constructs for the generation of single-copy chromosomal insertion of the reporter construct. Plasmid pJT10 and its derivatives will be useful for genetic studies in Aggregatibacter (Actinobacillus) and probably other genera of Pasteurellaceae, including Haemophilus, Pasteurella, and Mannheimia.

  4. Exploring factors influencing smoking behaviour in Malaysia.

    Science.gov (United States)

    Cheah, Yong Kang; Naidu, Balkish Mahadir

    2012-01-01

    The objective of present study is to investigate the determinants of smoking behaviour among adults in Malaysia. Findings of the Third National Health and Morbidity Survey (NHMS-3) by the Ministry of Health, Malaysia, were used. The sample consisted of 34,539 observations. A logistic regression model was thus applied to estimate the probability to participate in smoking. Age, income, gender, marital status, ethnicity, employment status, residential area, education, lifestyle and health status were statistically significant in affecting the likelihood of smoking. Specifically, youngsters, low income earners, males, unmarried individuals, Malays, employed individuals, rural residents and primary educated individuals were more likely to smoke. In conclusion, socio-demographic, lifestyle and health factors have significant impacts on smoking participation in Malaysia. Based on these empirical findings, several policy implications are suggested.

  5. Factors influencing dependence on mobile phone

    Directory of Open Access Journals (Sweden)

    Mohammad-Hossein Biglu

    2016-08-01

    Full Text Available Introduction: The purpose of current study was to investigate the relationship between the problematic use of mobile phone and Big Five personality traits among students of Tabriz University of Medical Sciences in Tabriz, Iran. Methods: A total number of 120 students (80 females and 40 males were selected by applying proportional randomized classification sampling method from Tabriz University of Medical Sciences. The Mobile Phone Problematic Use Scale (MPPUS and demographic questionnaire were used to gather data. Data were analyzed using SPSS software. Results: Analysis of gathered data showed that gender, neuroticism, extraversion, and openness to experience had positive correlation with the problematic use of mobile phone, whereas conscientiousness and agreeableness were not correlated with the problematic use of mobile phone. Conclusion: The evaluation of Big Five personality traits would be a reliable factor for predicting the problematic use of mobile phone among students.

  6. Factors influencing citizen participation in community management

    Directory of Open Access Journals (Sweden)

    Ali Shamai

    2015-04-01

    Full Text Available The primary objective of this study is to assess the factors affecting citizen participation in community management in district 13 of Tehran Municipality. Measured variables are: social cohesion, profitable partnerships, social-economic agencies, trust among civilians, trust in municipality management, feelings of powerlessness and social anomie. The results of the implementation of Pearson correlation test show that all of these variables had significant relationships with community participation in neighborhood management. The results of multiple regression analysis showed that three variables of social cohesion, profitable partnerships and socio-economic status had explained 37% of changes in citizen participation in community management while the changing social cohesion maintained the highest impact.

  7. Factors influencing excessive daytime sleepiness in adolescents

    Directory of Open Access Journals (Sweden)

    Thiago de Souza Vilela

    2016-04-01

    Full Text Available Abstract Objective: Sleep deprivation in adolescents has lately become a health issue that tends to increase with higher stress prevalence, extenuating routines, and new technological devices that impair adolescents' bedtime. Therefore, this study aimed to assess the excessive sleepiness frequency and the factors that might be associated to it in this population. Methods: The cross-sectional study analyzed 531 adolescents aged 10–18 years old from two private schools and one public school. Five questionnaires were applied: the Cleveland Adolescent Sleepiness Questionnaire; the Sleep Disturbance Scale for Children; the Brazilian Economic Classification Criteria; the General Health and Sexual Maturation Questionnaire; and the Physical Activity Questionnaire. The statistical analyses were based on comparisons between schools and sleepiness and non-sleepiness groups, using linear correlation and logistic regression. Results: Sleep deprivation was present in 39% of the adolescents; sleep deficit was higher in private school adolescents (p < 0.001, and there was a positive correlation between age and sleep deficit (p < 0.001; r = 0.337. Logistic regression showed that older age (p = 0.002; PR: 1.21 [CI: 1.07–1.36] and higher score level for sleep hyperhidrosis in the sleep disturbance scale (p = 0.02; PR: 1.16 [CI: 1.02–1.32] were risk factors for worse degree of sleepiness. Conclusions: Sleep deficit appears to be a reality among adolescents; the results suggest a higher prevalence in students from private schools. Sleep deprivation is associated with older age in adolescents and possible presence of sleep disorders, such as sleep hyperhidrosis.

  8. Factors influencing weight gain after renal transplantation.

    Science.gov (United States)

    Johnson, C P; Gallagher-Lepak, S; Zhu, Y R; Porth, C; Kelber, S; Roza, A M; Adams, M B

    1993-10-01

    Weight gain following renal transplantation occurs frequently but has not been investigated quantitatively. A retrospective chart review of 115 adult renal transplant recipients was used to describe patterns of weight gain during the first 5 years after transplantation. Only 23 subjects (21%) were overweight before their transplant. Sixty-six subjects (57%) experienced a weight gain of greater than or equal to 10%, and 49 subjects (43%) were overweight according to Metropolitan relative weight criteria at 1 year after transplantation. There was an inverse correlation between advancing age and weight gain, with the youngest patients (18-29 years) having a 13.3% weight gain and the oldest patients (age greater than 50 years) having the lowest gain of 8.3% at 1 year (P = 0.047). Black recipients experienced a greater weight gain than whites during the first posttransplant year (14.6% vs. 9.0%; P = 0.043), and maintained or increased this difference over the 5-year period. Men and women experienced comparable weight gain during the first year (9.5% vs. 12.1%), but women continued to gain weight throughout the 5-year study (21.0% total weight gain). The men remained stable after the first year (10.8% total weight gain). Recipients who experienced at least a 10% weight gain also increased their serum cholesterol (mean 261 vs. 219) and triglyceride (mean 277 vs. 159) levels significantly, whereas those without weight gain did not. Weight gain did not correlate with cumulative steroid dose, donor source (living-related versus cadaver), rejection history, pre-existing obesity, the number of months on dialysis before transplantation, or posttransplant renal function. Posttransplant weight gain is related mainly to demographic factors, not to treatment factors associated with the transplant. The average weight gain during the first year after renal transplantation is approximately 10%. This increased weight, coupled with changes in lipid metabolism, may be significant in

  9. Factors influencing professional life satisfaction among neurologists.

    Science.gov (United States)

    Teixeira-Poit, Stephanie M; Halpern, Michael T; Kane, Heather L; Keating, Michael; Olmsted, Murrey

    2017-06-19

    Predicted shortages in the supply of neurologists may limit patients' access to and quality of care for neurological disorders. Retaining neurologists already in practice provides one opportunity to support the overall supply of practicing neurologists. Understanding factors associated with professional life satisfaction (and dissatisfaction) and implementing policies to enhance satisfaction may encourage neurologists to remain in clinical practice. In this paper, we present results from the first study examining factors associated with professional life satisfaction among a large sample of U.S, neurologists. We collaborated with the AAN to survey a sample of U.S. neurologists about their professional life satisfaction. Analyses examined the association of physician and practice characteristics with aspects of professional life satisfaction, including satisfaction with their career in medicine, medical specialty, current position, relationship with colleagues, relationship with patients, work/life balance, and pay. The study population consisted of 625 neurologists. In multivariate regression analyses, no single group or population stratum indicated high (or low) responses to all aspects of satisfaction. Older neurologists reported higher satisfaction with career, specialty, and relationship with patients than younger neurologists. Female neurologists had significantly lower satisfaction with pay than male neurologists. Neurologists who spent more time in research and teaching had greater satisfaction with specialty, relationship with colleagues, and relationship with patients than those spending no time in research. Neurologists who practiced in small cities/rural areas reported lower satisfaction across multiple dimensions than those practicing in large urban areas. Neurologists in solo practice had greater satisfaction with the relationship with their patients, but lower satisfaction with pay. Satisfaction is a multidimensional construct that is associated with

  10. Influence of lactic acid bacteria on longevity of Caenorhabditis elegans and host defense against salmonella enterica serovar enteritidis.

    Science.gov (United States)

    Ikeda, Takanori; Yasui, Chikako; Hoshino, Kaori; Arikawa, Kentaro; Nishikawa, Yoshikazu

    2007-10-01

    This study aimed to develop a convenient model to investigate the senescence of host defenses and the influence of food and nutrition. A small soil nematode, Caenorhabditis elegans, was grown for 3 days from hatching on a lawn of Escherichia coli OP50 as the normal food source, and subsequently some of the nematodes were fed lactic acid bacteria (LAB). The life spans of worms fed LAB were significantly longer than the life spans of those fed OP50. To investigate the effect of age on host defenses, 3- to 7-day-old worms fed OP50 were transferred onto a lawn of Salmonella enterica serovar Enteritidis for infection. The nematodes died over the course of several days, and the accumulation of salmonella in the intestinal lumen suggested that the worms were infected. The 7-day-old worms showed a higher death rate during the 5 days after infection than nematodes infected at the age of 3 days; no clear difference was observed when the worms were exposed to OP50. We then investigated whether the LAB could exert probiotic effects on the worms' host defenses and improve life span. Seven-day-old nematodes fed LAB from the age of 3 days were more resistant to salmonella than worms fed OP50 until they were infected with salmonella. This study clearly showed that LAB can enhance the host defense of C. elegans and prolong life span. The nematode appears to be an appropriate model for screening useful probiotic strains or dietetic antiaging substances.

  11. Host Factors Invovled in the Entry of Coronaviruses into Mammalian Cells

    NARCIS (Netherlands)

    Burkard, C.

    2015-01-01

    Enveloped viruses need to fuse with a host cell membrane in order to deliver their genome into the host cell. While some viruses fuse with the plasma membrane, many viruses are endocytosed prior to fusion. Specific cues in the endosomal microenvironment induce conformational changes in the viral fus

  12. Fish consumption preferences and factors influencing it

    Directory of Open Access Journals (Sweden)

    Mehmet Ferit Can

    2015-06-01

    Full Text Available Fish consumption preferences are affected by individuals’ socioeconomic characteristics. The aims of the present paper were (i to obtain information on fish consumption level and frequency; (ii to investigate the associations between the socioeconomic characteristics of consumers and their preferences; and (iii to examine the influence of determinants on fish consumption. Data were gathered through a questionnaire completed by a total of 127 randomly selected individuals from different socioeconomic backgrounds from the Antakya, Turkey. The average consumption was found to be 2.98 kg/person/year for fish. Anchovies, gilt-head sea bream, and sea bass were reported as the most consumed three species, respectively. Significant differences in fish consumption were found among age groups, gender groups, and education groups, as well as between marital statuses. A majority of the consumers eat fish once a month throughout the year or only during the winter months. Fish consumption level and frequency were significantly positively correlated with education (p<0.01, income (p<0.05 and total meat consumption (p<0.01. The stepwise multiple regression model explained 41.7% (p<0.01 of the total variance for fish consumption. The amount and frequency of the consumption in the region, which is very far below the world and Turkey average especially for lower socioeconomic groups and for less-consumed fish species, can be increased by certain policies, such as training, advertising and different marketing strategies. Moreover, consumption should be distributed equally throughout the year instead of consuming only in certain seasons.

  13. Probiotics, gut microbiota, and their influence on host health and disease.

    Science.gov (United States)

    Sánchez, Borja; Delgado, Susana; Blanco-Míguez, Aitor; Lourenço, Anália; Gueimonde, Miguel; Margolles, Abelardo

    2017-01-01

    The gastrointestinal tract of mammals hosts a high and diverse number of different microorganisms, known as intestinal microbiota. Many probiotics were originally isolated from the gastrointestinal tract, and they were defined by the Food and Agriculture Organization of the United Nations (FAO)/WHO as "live microorganisms which when administered in adequate amounts confer a health benefit on the host." Probiotics exert their beneficial effects on the host through four main mechanisms: interference with potential pathogens, improvement of barrier function, immunomodulation and production of neurotransmitters, and their host targets vary from the resident microbiota to cellular components of the gut-brain axis. However, in spite of the wide array of beneficial mechanisms deployed by probiotic bacteria, relatively few effects have been supported by clinical data. In this regard, different probiotic strains have been effective in antibiotic-associated diarrhea or inflammatory bowel disease for instance. The aim of this review was to compile the molecular mechanisms underlying the beneficial effects of probiotics, mainly through their interaction with the intestinal microbiota and with the intestinal mucosa. The specific benefits discussed in this paper include among others those elicited directly through dietary modulation of the human gut microbiota.

  14. Host plants indirectly influence plant virus transmission by altering gut cysteine protease activity of aphid vectors

    Science.gov (United States)

    Luteoviridae), transmitted exclusively by aphids in a circulative manner. PLRV transmission efficiency was significantly reduced when a clonal lineage of M. persicae was reared on turnip as compared to the weed physalis, a transient effect caused by a host-switch response. A trend of higher PLRV tit...

  15. Host influence in the genomic composition of flaviviruses: A multivariate approach.

    Science.gov (United States)

    Simón, Diego; Fajardo, Alvaro; Sóñora, Martín; Delfraro, Adriana; Musto, Héctor

    2017-10-28

    Flaviviruses present substantial differences in their host range and transmissibility. We studied the evolution of base composition, dinucleotide biases, codon usage and amino acid frequencies in the genus Flavivirus within a phylogenetic framework by principal components analysis. There is a mutual interplay between the evolutionary history of flaviviruses and their respective vectors and/or hosts. Hosts associated to distinct phylogenetic groups may be driving flaviviruses at different pace and through various sequence landscapes, as can be seen for viruses associated with Aedes or Culex spp., although phylogenetic inertia cannot be ruled out. In some cases, viruses face even opposite forces. For instance, in tick-borne flaviviruses, while vertebrate hosts exert pressure to deplete their CpG, tick vectors drive them to exhibit GC-rich codons. Within a vertebrate environment, natural selection appears to be acting on the viral genome to overcome the immune system. On the other side, within an arthropod environment, mutational biases seem to be the dominant forces. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Influence of host plants on sexual communication in the herbivorous bug Lygocoris pabulinus

    NARCIS (Netherlands)

    Groot, A.T.; Visser, J.H.

    2001-01-01

    Host plant volatiles may be involved in the sexual communication of insects in several ways. In the pheromone-producing sex, these volatiles may affect pheromone production or release and, in the receptive sex, plant volatiles may have a synergistic effect on the attraction to sex pheromone. We cond

  17. Enhancement and abrogation : modifications of host immune status influence IL-2 and LAK cell immunotherapy

    NARCIS (Netherlands)

    E.P. Steller (Erick)

    1988-01-01

    textabstractThis thesis will discuss the role immune cells and the host immune system can play in enhancement and abrogation of this novel immunotherapy with interleukin 2 and lymphokine-activated killer cells. Chapter 3 and 4 will discuss the scoring methods in this intraperitoneal cancer and immun

  18. Atmospheric Humidity Influences Oviposition Rate of Tetranychus urticae (Acari: Tetranychidae) Through Morphological Responses of Host Cucumis sativus Leaves.

    Science.gov (United States)

    Shibuya, T; Itagaki, K; Ueyama, S; Hirai, N; Endo, R

    2016-02-01

    We investigated the effects of morphology of host cucumber, Cucumis sativus L., leaves acclimatized to different atmospheric humidity levels on oviposition by adult females of the twospotted spider mite, Tetranychus urticae Koch. Cucumber seedlings were grown at a vapor pressure deficit (VPD) of 0.4, 1.9, or 3.0 kPa at 28°C (90%, 50%, or 20% relative humidity, respectively) in growth chambers until the second true leaves had expanded. Adult females of T. urticae were released on the adaxial surfaces of leaf squares cut from first and second true leaves in each treatment group, and held in the same humidity condition. Eggs were counted 2 d after release. The lower acclimatization humidity (higher VPD) increased trichome (leaf hair) density of the host leaves and oviposition rate, but the relationship between the trichome and oviposition differed between leaf positions. The leaf mass per area (LMA) was greater in first true leaves than in second true leaves, but was not influenced by VPD. A linear regression model with oviposition rate as the dependent variable and trichome density and LMA as independent variables showed that both variables influenced the oviposition rate approximately equally. We conclude that oviposition was accelerated under low humidity (high VPD) conditions indirectly probably through an increase in the trichome density of host leaves.

  19. Spatial and temporal factors affecting parasite genotypes encountered by hosts: empirical data from American dog ticks (Dermacentor variabilis) parasitising raccoons (Procyon lotor).

    Science.gov (United States)

    Dharmarajan, G; Beasley, J C; Rhodes, O E

    2010-06-01

    The American dog tick (Dermacentor variabilis) is an important vector of numerous pathogens of humans and animals. In this study, we analysed population genetic patterns in D. variabilis at scales of the host individual (infrapopulation) and population (component population) to elucidate fine-scale spatial and temporal factors influencing transmission dynamics. We genotyped D. variabilis collected from raccoons (Procyon lotor) trapped in two habitat patches (located in Indiana, USA) which were spatially proximate (5.9 km) and limited in size (10.48 Ha and 25.47 Ha, respectively). Despite the fine spatial sampling scale, our analyses revealed significant genetic differentiation amongst component populations and infrapopulations (within each component population), indicating a non-random pattern of encountering tick genotypes by raccoons at both scales evaluated. We found evidence for male-biased dispersal in the ticks themselves (in one component population) and an age-bias in spatial scales at which raccoons encountered ticks in the environment. At the scale of the component population, our analyses revealed that raccoons encountered ticks from a limited number of D. variabilis family groups, likely due to high reproductive variance amongst individual ticks. Finally, we found evidence for a temporal effect with raccoons encountering ticks in the environment as "clumps" of related individuals. While the genetic structure of parasite populations are increasingly being investigated at small spatial scales (e.g. the infrapopulation), our data reveal that genetic structuring can originate at scales below that of the infrapopulation, due to the interaction between temporal and biological factors affecting the encounter of parasites by individual hosts. Ultimately, our data indicate that genetic structure in parasites must be viewed as a consequence of both spatial and temporal variance in host-parasite interactions, which in turn are driven by demographic factors related

  20. Identical accumulation and immobilization of sulfated and nonsulfated Nod factors in host and nonhost root hair cell walls

    NARCIS (Netherlands)

    Goedhart, J.; Bono, J.J.; Bisseling, T.; Gadella, T.W.J.

    2003-01-01

    Nod factors are signaling molecules secreted by Rhizobium bacteria. These lipo-chitooligosaccharides (LCOs) are required for symbiosis with legumes and can elicit specific responses at subnanomolar concentrations on a compatible host. How plants perceive LCOs is unclear. In this study, using fluores

  1. Analyses of risk factors for intestinal acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

    Institute of Scientific and Technical Information of China (English)

    燕法红

    2014-01-01

    Objective To investigate the risk factors of intestinal acute graft-versus-host disease(aGVHD)after allogeneic hematopoietic stem cell transplantation(allo-HSCT).Methods The clinical data of 534 cases of 533 patients undergoing allo-HSCT during Jan 2004 and Sep 2012were retrospectively analyzed.The effects of donor-recipient HLA

  2. Factors influencing phototaxis in nocturnal migrating birds.

    Science.gov (United States)

    Zhao, Xuebing; Chen, Mingyan; Wu, Zhaolu; Wang, Zijiang

    2014-12-01

    Many migratory bird species fly during the night (nocturnal migrants) and have been shown to display some phototaxis to artificial light. During 2006 to 2009, we investigated phototaxis in nocturnal migrants at Jinshan Yakou in Xinping County (N23°56', E101°30'; 2400 m above sea-level), and at the Niaowang Mountain in Funing County (N23°30', E105°35'; 1400 m above sea-level), both in the Yunnan Province of Southwest China. A total of 5069 birds, representing 129 species, were captured by mist-netting and artificial light. The extent of phototaxis effect on bird migration was examined during all four seasons, three phases of the moon, and under two weather conditions (mist and wind). Data were statistically analyzed to determine the extent to which these factors may impact phototaxis of nocturnal migrants. The results point to phototaxis in birds migrating in the spring and autumn, especially in the autumn. Furthermore, migrating birds were more readily attracted to artificial lights during nights with little moonlight, mist, and a headwind. Regardless of the initial orientation in which birds flew, either following the wind or against the wind, birds would always fly against the wind when flying towards the light. This study broadens our understanding of the nocturnal bird migration, potentially resulting in improved bird ringing practices, increased awareness, and better policies regarding bird protection.

  3. Factors influencing riverine fish assemblages in Massachusetts

    Science.gov (United States)

    Armstrong, David S.; Richards, Todd A.; Levin, Sara B.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the Massachusetts Department of Conservation and Recreation, Massachusetts Department of Environmental Protection, and the Massachusetts Department of Fish and Game, conducted an investigation of fish assemblages in small- to medium-sized Massachusetts streams. The objective of this study was to determine relations between fish-assemblage characteristics and anthropogenic factors, including impervious cover and estimated flow alteration, relative to the effects of environmental factors, including physical-basin characteristics and land use. The results of this investigation supersede those of a preliminary analysis published in 2010. Fish data were obtained for 669 fish-sampling sites from the Massachusetts Division of Fisheries and Wildlife fish-community database. A review of the literature was used to select fish metrics - species richness, abundance of individual species, and abundances of species grouped on life history traits - responsive to flow alteration. The contributing areas to the fish-sampling sites were delineated and used with a geographic information system to determine a set of environmental and anthropogenic factors that were tested for use as explanatory variables in regression models. Reported and estimated withdrawals and return flows were used together with simulated unaltered streamflows to estimate altered streamflows and indicators of flow alteration for each fish-sampling site. Altered streamflows and indicators of flow alteration were calculated on the basis of methods developed in a previous U.S. Geological Survey study in which unaltered daily streamflows were simulated for a 44-year period (water years 1961-2004), and streamflow alterations were estimated by use of water-withdrawal and wastewater-return data previously reported to the State for the 2000-04 period and estimated domestic-well withdrawals and septic-system discharges. A variable selection process, conducted using principal

  4. Influence of Wolbachia on host gene expression in an obligatory symbiosis

    Directory of Open Access Journals (Sweden)

    Kremer Natacha

    2012-01-01

    Full Text Available Abstract Background Wolbachia are intracellular bacteria known to be facultative reproductive parasites of numerous arthropod hosts. Apart from these reproductive manipulations, recent findings indicate that Wolbachia may also modify the host’s physiology, notably its immune function. In the parasitoid wasp, Asobara tabida, Wolbachia is necessary for oogenesis completion, and aposymbiotic females are unable to produce viable offspring. The absence of egg production is also associated with an increase in programmed cell death in the ovaries of aposymbiotic females, suggesting that a mechanism that ensures the maintenance of Wolbachia in the wasp could also be responsible for this dependence. In order to decipher the general mechanisms underlying host-Wolbachia interactions and the origin of the dependence, we developed transcriptomic approaches to compare gene expression in symbiotic and aposymbiotic individuals. Results As no genetic data were available on A. tabida, we constructed several Expressed Sequence Tags (EST libraries, and obtained 12,551 unigenes from this species. Gene expression was compared between symbiotic and aposymbiotic ovaries through in silico analysis and in vitro subtraction (SSH. As pleiotropic functions involved in immunity and development could play a major role in the establishment of dependence, the expression of genes involved in oogenesis, programmed cell death (PCD and immunity (broad sense was analyzed by quantitative RT-PCR. We showed that Wolbachia might interfere with these numerous biological processes, in particular some related to oxidative stress regulation. We also showed that Wolbachia may interact with immune gene expression to ensure its persistence within the host. Conclusions This study allowed us to constitute the first major dataset of the transcriptome of A. tabida, a species that is a model system for both host/Wolbachia and host/parasitoid interactions. More specifically, our results

  5. The Influence of Host Plant Volatiles on the Attraction of Longhorn Beetles to Pheromones.

    Science.gov (United States)

    Collignon, R Maxwell; Swift, Ian P; Zou, Yunfan; McElfresh, J Steven; Hanks, Lawrence M; Millar, Jocelyn G

    2016-03-01

    Host plant volatiles have been shown to strongly synergize the attraction of some longhorn beetle species (Coleoptera: Cerambycidae) to their pheromones. This synergism is well documented among species that infest conifers, but less so for angiosperm-infesting species. To explore the extent of this phenomenon in the Cerambycidae, we first tested the responses of a cerambycid community to a generic pheromone blend in the presence or absence of chipped material from host plants as a source of host volatiles. In the second phase, blends of oak and conifer volatiles were reconstructed, and tested at low, medium, and high release rates with the pheromone blend. For conifer-infesting species in the subfamilies Spondylidinae and Lamiinae, conifer volatiles released at the high rate synergized attraction of some species to the pheromone blend. When comparing high-release rate conifer blend with high-release rate α-pinene as a single component, species responses varied, with Asemum nitidum LeConte being most attracted to pheromones plus α-pinene, whereas Neospondylis upiformis (Mannerheim) were most attracted to pheromones plus conifer blend and ethanol. For oak-infesting species in the subfamily Cerambycinae, with the exception of Phymatodes grandis Casey, which were most attracted to pheromones plus ethanol, neither synthetic oak blend nor ethanol increased attraction to pheromones. The results indicate that the responses to combinations of pheromones with host plant volatiles varied from synergistic to antagonistic, depending on beetle species. Release rates of host plant volatiles also were important, with some high release rates being antagonistic for oak-infesting species, but acting synergistically for conifer-infesting species.

  6. EGFR and EphA2 are host factors for hepatitis C virus entry and possible targets for antiviral therapy

    Science.gov (United States)

    Lupberger, Joachim; Zeisel, Mirjam B.; Xiao, Fei; Thumann, Christine; Fofana, Isabel; Zona, Laetitia; Davis, Christopher; Mee, Christopher J.; Turek, Marine; Gorke, Sebastian; Royer, Cathy; Fischer, Benoit; Zahid, Muhammad N.; Lavillette, Dimitri; Fresquet, Judith; Cosset, François-Loïc; Rothenberg, S Michael; Pietschmann, Thomas; Patel, Arvind H.; Pessaux, Patrick; Doffoël, Michel; Raffelsberger, Wolfgang; Poch, Olivier; Mckeating, Jane A.; Brino, Laurent; Baumert, Thomas F.

    2011-01-01

    Hepatitis C virus (HCV) is a major cause of liver disease. Therapeutic options are limited and preventive strategies are absent. Entry is the first step of infection and requires the cooperative interaction of several host cell factors. Using a functional RNAi kinase screen we identified epidermal growth factor receptor and ephrin receptor A2 as host co-factors for HCV entry. Blocking of kinase function by approved inhibitors broadly inhibited HCV infection of all major HCV genotypes and viral escape variants in cell culture and an animal model in vivo. Receptor tyrosine kinases (RTKs) mediate HCV entry by regulating CD81-claudin-1 co-receptor associations and membrane fusion. These results identify RTKs as novel HCV entry co-factors and uncover that kinase inhibitors have significant antiviral activity. Inhibition of RTK function may constitute a novel approach for prevention and treatment of HCV infection. PMID:21516087

  7. Biotic mortality factors affecting emerald ash borer (Agrilus planipennis) are highly dependent on life stage and host tree crown condition.

    Science.gov (United States)

    Jennings, D E; Duan, J J; Shrewsbury, P M

    2015-10-01

    Emerald ash borer (EAB), Agrilus planipennis, is a serious invasive forest pest in North America responsible for killing tens to hundreds of millions of ash trees since it was accidentally introduced in the 1990 s. Although host-plant resistance and natural enemies are known to be important sources of mortality for EAB in Asia, less is known about the importance of different sources of mortality at recently colonized sites in the invaded range of EAB, and how these relate to host tree crown condition. To further our understanding of EAB population dynamics, we used a large-scale field experiment and life-table analyses to quantify the fates of EAB larvae and the relative importance of different biotic mortality factors at 12 recently colonized sites in Maryland. We found that the fates of larvae were highly dependent on EAB life stage and host tree crown condition. In relatively healthy trees (i.e., with a low EAB infestation) and for early instars, host tree resistance was the most important mortality factor. Conversely, in more unhealthy trees (i.e., with a moderate to high EAB infestation) and for later instars, parasitism and predation were the major sources of mortality. Life-table analyses also indicated how the lack of sufficient levels of host tree resistance and natural enemies contribute to rapid population growth of EAB at recently colonized sites. Our findings provide further evidence of the mechanisms by which EAB has been able to successfully establish and spread in North America.

  8. Influence of previous experience on the preference, food utilization and performance of Ascia monuste orseis wild larvae (Godart) (Lepidoptera: Pieridae) for three different hosts.

    Science.gov (United States)

    Santana, A F K; Zucoloto, F S

    2011-01-01

    The exhaustion of food resources which occurs during the ontogenetic growth of Ascia monuste orseis (Godart) results in the dispersion of older larvae to nearby plants in order to complete their development, which might expose these animals to the nutritional variation of the hosts found. This study aimed to verify whether the food ingested in the beginning of the development influences the larvae host preference and whether the shift to a new host can affect the digestion and performance of A. monuste orseis, using two natural hosts: kale (Brassica oleracea var. acephala) and rocket (Eruca sativa), or kale and cabbage (B. oleracea var. capitata). Larvae were reared throughout their larval development on a single host or on two different hosts. When a host change was tested, larvae were reared for four instars on a host, and offered the other host plant in the fifth instar. Development time, percentage of pupation and emergence, pupal weight, fecundity and digestive indices were evaluated. The change in feeding preference for kale and for rocket in the fourth instar, when those were the original hosts, respectively, shows that prior experience plays a major role in food preference of immature A. monuste orseis. The shift can be beneficial for larval development, depending on the order of the hosts; in general, larvae fed on kale at the end of the development showed better performance. Our results presented strong evidence of a considerable phenotypic plasticity in A. monuste orseis for host preferences.

  9. Factors influencing ring closure through olefin metathesis - A perspective

    Indian Academy of Sciences (India)

    Subrata Ghosh; Sarita Ghosh; Niladri Sarkar

    2006-05-01

    Success of ring closure reactions of substrates having two terminal alkenes through olefin metathesis depends on a number of factors such as catalysts, nature and size of the rings to be formed and the substituents/functional groups present on the alkenes as well as at the allylic position. This article presents an overview of these influencing factors with illustrative examples.

  10. Professional Identity Development in Higher Education: Influencing Factors

    Science.gov (United States)

    Barbarà-i-Molinero, Alba; Cascón-Pereira, Rosalía; Hernández-Lara, Ana beatriz

    2017-01-01

    Purpose: In the last few years, the interest on professional identity development (PID) and the factors that influence PID has become central in higher education (HE) literature. However, the knowledge developed in this domain has focussed on a factor at a time and on a degree or discipline, thus being difficult to have a general picture of all…

  11. Influence of Psychological Factors on the Improvement of Spoken English

    Institute of Scientific and Technical Information of China (English)

    董宁

    2013-01-01

      From learner's innermost feelings,the author attempts to elaborate the influences of psychological factors on improving the spoken language. The study of spoken English is a very complex process, which is affected easily by learner's linguistic environment and character. We can draw a conclusion that psychological factors are an important problem and cannot be neglected.

  12. Factors influencing societal response of nanotechnology : an expert stakeholder analysis

    NARCIS (Netherlands)

    Gupta, N.; Fischer, A.R.H.; Lans, van der I.A.; Frewer, L.J.

    2012-01-01

    Nanotechnology can be described as an emerging technology and, as has been the case with other emerging technologies such as genetic modification, different socio-psychological factors will potentially influence societal responses to its development and application. These factors will play an import

  13. The influence of motivational factors on choice behaviour

    NARCIS (Netherlands)

    Van Amelsfort, D.H.; Steg, L.; Bliemer, M.C.J.; Schuitema, G.

    2010-01-01

    In this paper we investigate if and how motivational factors influence choice behaviour. We study four motivational factors: attitude towards car use, personal norm to reduce car use, car use habit, and perceived behavioural control to change car use to explain the choice behaviour of respondents in

  14. Using mixed methods to identify factors influencing patient flow.

    Science.gov (United States)

    Van Vaerenbergh, Cindy

    2009-11-01

    An effective method of identifying operational factors that influence patient flow can potentially lead to improvements and thus have huge benefits on the efficiency of hospital departments. This paper presents a new inductive mixed-method approach to identify operational factors that influence patient flow through an accident and emergency (A&E) department. Preliminary explorative observations were conducted, followed by semi-structured interviews with key stakeholders. A questionnaire survey of all medical, nursing, porter and clerical staff was then conducted. The observations provided factors for further exploration: skill-mix, long working hours, equipment availability, lack of orientation programmes, inefficient IT use and issues regarding communication structures. Interviewees highlighted several factors, including availability of medical supervision and senior nursing staff, nursing documentation issues, lack of morale due to overcrowding, personality differences and factors relating to the department layout. The questionnaire respondents strongly supported the importance of the previously identified factors. This paper demonstrates an effective mixed-method approach that can be replicated by other health-care managers to identify factors influencing patient flow. Further benefits include increased volume and quality of data, increased staff awareness for the influence of internal factors on patient flow and enhancing the evidence base for future decision making when prioritizing A&E projects.

  15. Psychosocial Factors Influencing Competency of Children's Statements on Sexual Trauma

    Science.gov (United States)

    Kim, Tae Kyung; Choi, Soul; Shin, Yee Jin

    2011-01-01

    Objectives: The objectives of this study are to assess children's competence to state their traumatic experience and to determine psychosocial factors influencing the competency of children's statements, such as emotional factors of children and parents and trauma-related variables, in Korean child sex abuse victims. Methods: We enrolled 214…

  16. Factors Influencing Technology Planning in Developing Countries: A Literature Review

    Science.gov (United States)

    Keengwe, Jared; Malapile, Sandy

    2014-01-01

    This article is a literature review concerning the factors that play an important role in the development of educational technology plans in the educational system of developing countries (DCs). Largely, the technology plans are influenced by factors that emanates from within the country (internal) and those outside of their borders (external).…

  17. Factors that Influence Students' Decision to Dropout of Online Courses

    Science.gov (United States)

    Willging, Pedro A.; Johnson, Scott D.

    2009-01-01

    Although there are many reasons why students dropout of college courses, those reasons may be unique for students who are enrolled in an online program. Issues of isolation, disconnectedness, and technological problems may be factors that influence a student to leave a course. To understand these factors, an online survey was developed to collect…

  18. Factors Influencing Psychological Help Seeking in Adults: A Qualitative Study

    Science.gov (United States)

    Topkaya, Nursel

    2015-01-01

    The aim of the current research is to identify which factors, and in what direction these factors influence adults' decisions to seek psychological help for their personal problems. The research was designed as a phenomenology model; the data was gathered through the semi-structured interview technique, which is mostly used in qualitative research…

  19. FACTORS INFLUENCING YIELD SPREADS OF THE MALAYSIAN BONDS

    Directory of Open Access Journals (Sweden)

    Norliza Ahmad

    2009-01-01

    Full Text Available Malaysian bond market is developing rapidly but not much is understood in terms of macroeconomic factors that could influence the yield spread of the Ringgit Malaysian denominated bonds. Based on a multifactor model, this paper examines the impact of four macroeconomic factors namely: Kuala Lumpur Composite Index (KLCI, Industry Production Index (IPI, Consumer Price Index (CPI and interest rates (IR on bond yield spread of the Malaysian Government Securities (MGS and Corporate Bonds (CBs for a period from January 2001 to December 2008. The findings support the expected hypotheses that CPI and IR are the major drivers that influence the changes in MGS yield spreads. However IPI and KLCI have weak and no influence on MGS yield spreads respectively Whilst IR, CPI and IPI have significant influence on the yield spreads of CB1, CB2 and CB3, KLCI has significant influence only on the CB1 yield spread but not on CB2 and CB3 yield spreads.

  20. Factors influencing nursing career choices and choice of study program.

    Science.gov (United States)

    Haron, Yafa; Reicher, Sima; Riba, Shoshana

    2014-01-01

    In advance of a recruitment campaign, Israeli first-year nursing students of all ethnicities were surveyed to elucidate what factors had influenced them to make nursing their career and what sort of training track they preferred. The responses made it clear that different factors influence different groups differently. There were noticeable differences by gender, age, and ethnicity. Overall, training institutions were chosen for their closeness to the student's home but other factors also operated among particular groups, such as institutional prestige and flexible entry criteria. There was a blatant preference for academic, particularly university-sited, programs over diploma programs.

  1. A Discussion on Motivation Factor Influencing Second Language Acquisition

    Institute of Scientific and Technical Information of China (English)

    盛芊芊

    2016-01-01

    Various characteristics can influence students'second language acquisition and language development, which in-cludes age, gender, personality, cognitive ability, motivation, learning strategies and so on. Among all these factors mentioned, motivation factor that is categorized into learner factors affects learner's learning effect to a great extent. In this paper, motiva-tion characteristic that influences second language learning are discussed. At last, some strategies on the real classroom teaching application are provided after the discussion, which aims at making contribution to the second language teaching process as well as students'language development.

  2. Nurturing Sport Expertise: Factors Influencing the Development of Elite Athlete

    Science.gov (United States)

    Baker, Joseph; Horton, Sean; Robertson-Wilson, Jennifer; Wall, Michael

    2003-01-01

    The development of expertise in sport is the result of successful interaction of biological, psychological, and sociological constraints. This review examines the training and environmental factors that influence the acquisition of sport expertise. Research examining the quality and quantity of training indicate that these two elements are crucial predictors of attainment. In addition, the possession of resources such as parental support and adequate coaching are essential. Social factors such as cultural influences and the relative age effect are also considered as determinants of sport expertise. Although it is evident that environmental factors are essential to the acquisition of high levels of sport development, further research is clearly required. PMID:24616603

  3. NURTURING SPORT EXPERTISE: FACTORS INFLUENCING THE DEVELOPMENT OF ELITE ATHLETE

    Directory of Open Access Journals (Sweden)

    Michael Wall

    2003-03-01

    Full Text Available The development of expertise in sport is the result of successful interaction of biological, psychological, and sociological constraints. This review examines the training and environmental factors that influence the acquisition of sport expertise. Research examining the quality and quantity of training indicate that these two elements are crucial predictors of attainment. In addition, the possession of resources such as parental support and adequate coaching are essential. Social factors such as cultural influences and the relative age effect are also considered as determinants of sport expertise. Although it is evident that environmental factors are essential to the acquisition of high levels of sport development, further research is clearly required

  4. Which factors influence women in the decision to breastfeed?

    Directory of Open Access Journals (Sweden)

    Cândida Canicali Primo

    Full Text Available Objective.Identify the factors that influence women in the decision to breastfeed. Methods. Integrative review. Information was gathered from original articles, case studies, theoretical studies, consensus and systematic reviews published between 2007-2013 in Spanish, Portuguese and English and recovered in the databases MEDLINE and LILACS. The descriptors used in this study were: breastfeeding, maternal behavior, risk factors, lactation and newborn. Results. Were included 30 articles, grouped into five categories. Factors influencing the decision of the breastfeeding woman are a convergence of breastfeeding's advantages, benefits and justifications, family, social and professional support, sociodemographic and clinical characteristics of women, personal experience and family tradition and personal choice. Conclusion. The decision to breastfeed by women is influenced by a convergence of factors. It is essential the role of nursing to encourage women in the decision to initiate and maintain breastfeeding her child.

  5. RISK FACTORS INFLUENCING CONSTRUCTION PROCUREMENT PERFORMANCE IN NIGERIA

    OpenAIRE

    Dahiru, A; Aminu, Muhammad Bashir

    2016-01-01

    One of the challenges facing construction procurement performance is the failure to determine the risk related factors limiting its success. These risk factors can cause a significant increase in the procurement cost leading to an increase in the overall project cost. The purpose of this study is to identify and evaluate the risk factors influencing construction procurement performance with a view to achieve the overall project performance. The objectives are to establish a relative significa...

  6. Environmental factors influencing asexual reproductive processes in echinoderms

    OpenAIRE

    Mladenov, Pv

    1996-01-01

    This review provides a brief update of the occurrence and adaptive significance of asexual reproduction in echinoderms. It then focuses on the state of knowledge of biotic and abiotic factors that influence asexual processes in this group, particularly factors that may play a role in regulating the expression and relative proportion of asexual versus sexual phenotypes within populations of species, as well as factors modulating and triggering asexual processes. The information presented in th...

  7. Possible Influence of MLP Regulators in Foliage of Host Species on Invasion of Phyllophagous Insects

    Directory of Open Access Journals (Sweden)

    Vasiliy I. Ponomarev

    2010-01-01

    Full Text Available On the northern border of the Gypsy moth area (Lymantria dispar L., 1758, caterpillars are reorient to exogenous regulators of membrane lipid peroxidation in connection with repeated cold periods during feeding. In case of an introduction of host plants with high contents of exogenous regulators of MLP (e.g. Fe2+ in foliage in these areas that may affect diapause duration, the boundaries of spreading and intensity of outbreaks may change.

  8. The Influence of Multiple Host Contacts on the Acquisition and Transmission of Dengue-2 Virus

    Science.gov (United States)

    1993-01-01

    live through the extrinsic incubation period. Therefore, Iap is an estimate of the daily number of infective ft. agg3=i generated from a single human...interrupted attempts to blood food on an active host. Such interruptions could include interruption of probing. Conversely, there is reason to believe that AS...induces life long immunity in humans. In areas where dengue viruses are prevalent, dengue fever is usually a childhood disease and most of the adult

  9. Characteristics of the human host have little influence on which local Schistosoma mansoni populations are acquired.

    Directory of Open Access Journals (Sweden)

    Lúcio M Barbosa

    Full Text Available BACKGROUND: Brazil remains the country in the Americas with the highest prevalence of schistosomiasis. A combination of control efforts and development, however, has sharply reduced its intensity and distribution. The acquisition of specific schistosome populations may be dependent on host characteristics such as sex, age, geography, work, habits and culture. How these and other host characteristics align with parasite subpopulations may guide approaches to improve control. METHODOLOGY: A cohort of more than 90% of the residents in two rural communities in Brazil participated in an epidemiologic survey of demographic, socio-economic and behavioral characteristics. The variables sex, age, intensity of infection, socio-economic index, % lifetime spent on site, previous infection, and trips outside the district were used to group parasites infecting individuals. Schistosoma mansoni infection status was determined by examination of stools submitted on 3 different days. The aggregate of eggs collected from the whole stool was used to determine degree of population differentiation from allele frequencies for 15 microsatellites. CONCLUSIONS/SIGNIFICANCE: Infection prevalence was 41% for these communities, and the epidemiologic characteristics were similar to many of the endemic areas of Brazil and the world. Parasite population structuring was observed between the two communities (Jost's D 0.046, CI95% 0.042-0.051, although separated by only 8 km and connected by a highway. No structuring was observed when infected individuals were stratified by host's biologic, demographic or epidemiologic characteristics. Those most heavily infected best reflected the communities' overall parasite diversity. The lack of differentiation within villages suggests that individuals are likely to get infected at the same sites or that the same parasite multilocus genotypes can be found at most sites. The geographic structuring between villages and the lack of structuring

  10. Drosophila host model reveals new enterococcus faecalis quorum-sensing associated virulence factors.

    Science.gov (United States)

    Teixeira, Neuza; Varahan, Sriram; Gorman, Matthew J; Palmer, Kelli L; Zaidman-Remy, Anna; Yokohata, Ryoji; Nakayama, Jiro; Hancock, Lynn E; Jacinto, António; Gilmore, Michael S; de Fátima Silva Lopes, Maria

    2013-01-01

    Enterococcus faecalis V583 is a vancomycin-resistant clinical isolate which belongs to the hospital-adapted clade, CC2. This strain harbours several factors that have been associated with virulence, including the fsr quorum-sensing regulatory system that is known to control the expression of GelE and SprE proteases. To discriminate between genes directly regulated by Fsr, and those indirectly regulated as the result of protease expression or activity, we compared gene expression in isogenic mutants of V583 variously defective in either Fsr quorum sensing or protease expression. Quorum sensing was artificially induced by addition of the quorum signal, GBAP, exogenously in a controlled manner. The Fsr regulon was found to be restricted to five genes, gelE, sprE, ef1097, ef1351 and ef1352. Twelve additional genes were found to be dependent on the presence of GBAP-induced proteases. Induction of GelE and SprE by GBAP via Fsr resulted in accumulation of mRNA encoding lrgAB, and this induction was found to be lytRS dependent. Drosophila infection was used to discern varying levels of toxicity stemming from mutations in the fsr quorum regulatory system and the genes that it regulates, highlighting the contribution of LrgAB and bacteriocin EF1097 to infection toxicity. A contribution of SprE to infection toxicity was also detected. This work brought to light new players in E. faecalis success as a pathogen and paves the way for future studies on host tolerance mechanisms to infections caused by this important nosocomial pathogen.

  11. Two host microRNAs influence WSSV replication via STAT gene regulation

    Science.gov (United States)

    Huang, Ying; Wang, Wen; Ren, Qian

    2016-01-01

    MicroRNAs (miRNAs) have important roles in post-transcriptional regulation of gene expression. During viral infection, viruses utilize hosts to enhance their replication by altering cellular miRNAs. The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway plays crucial roles in the antiviral responses. In this study, two miRNAs (miR-9041 and miR-9850) from Macrobrachium rosenbergii were found to promote white spot syndrome virus (WSSV) replication. The up-regulation of miR-9041 or miR-9850 suppresses STAT expression in the gills of M. rosenbergii, which subsequently down-regulates the expression of its downstream dynamin (Dnm) genes: Dnm1, Dnm2, and Dnm3. Knockdown of miR-9041 and miR-9850 restricts WSSV replication by up-regulating STAT and Dnm gene expression. The silencing of STAT, Dnm1, Dnm2, or Dnm3 led to an increase of the number of WSSV copies in shrimp. The injection of recombinant Dnm1, Dnm2, or Dnm3 proteins could inhibit WSSV replication in vivo. Overall, our research indicates the roles of host miRNAs in the enhancement of WSSV replication by regulating the host JAK/STAT pathway. PMID:27029712

  12. Genetic and environmental factors influencing the Placental Growth Factor (PGF) variation in two populations

    DEFF Research Database (Denmark)

    Sorice, Rossella; Ruggiero, Daniela; Nutile, Teresa

    2012-01-01

    . However, to date, no information is available regarding the genetics of PGF variability. Furthermore, even though the effect of environmental factors (e.g.: cigarette smoking) on angiogenesis has been explored, no data on the influence of these factors on PGF levels have been reported so far. Here we have...... strongly replicated in the Danish sample. These results, for the first time, support the hypothesis of the presence of genetic and environmental factors influencing PGF plasma variability....

  13. The wills of older people: risk factors for undue influence.

    Science.gov (United States)

    Peisah, C; Finkel, S; Shulman, K; Melding, P; Luxenberg, J; Heinik, J; Jacoby, R; Reisberg, B; Stoppe, G; Barker, A; Firmino, H; Bennett, H

    2009-02-01

    As people live longer, there is increasing potential for mental disorders to interfere with testamentary distribution and render older people more vulnerable to "undue influence" when they are making a will. Accordingly, clinicians dealing with the mental disorders of older people will be called upon increasingly to advise the courts about a person's vulnerability to undue influence. A Subcommittee of the IPA Task Force on Testamentary Capacity and Undue Influence undertook to establish consensus on the definition of undue influence and the provision of guidelines for expert assessment of risk factors for undue influence. International jurisdictions differ in their approach to the notion of undue influence. Despite differences in legal systems, from a clinical perspective, the subcommittee identified some common "red flags" which might alert the expert to risk of undue influence. These include: (i) social or environmental risk factors such as dependency, isolation, family conflict and recent bereavement; (ii) psychological and physical risk factors such as physical disability, deathbed wills, sexual bargaining, personality disorders, substance abuse and mental disorders including dementia, delirium, mood and paranoid disorders; and (iii) legal risk factors such as unnatural provisions in a will, or provisions not in keeping with previous wishes of the person making the will, and the instigation or procurement of a will by a beneficiary. This review provides some guidance for experts who are requested by the courts to provide an opinion on the risk of undue influence. Whilst international jurisdictions require different thresholds of proof for a finding of undue influence, there is good international consensus on the clinical indicators for the concept.

  14. A paradigm for endosymbiotic life: cell differentiation of Rhizobium bacteria provoked by host plant factors.

    Science.gov (United States)

    Kondorosi, Eva; Mergaert, Peter; Kereszt, Attila

    2013-01-01

    Symbiosis between Rhizobium bacteria and legumes leads to the formation of the root nodule. The endosymbiotic bacteria reside in polyploid host cells as membrane-surrounded vesicles where they reduce atmospheric nitrogen to support plant growth by supplying ammonia in exchange for carbon sources and energy. The morphology and physiology of endosymbionts, despite their common function, are highly divergent in different hosts. In galegoid plants, the endosymbionts are terminally differentiated, uncultivable polyploid cells, with remarkably elongated and even branched Y-shaped cells. Bacteroid differentiation is controlled by host peptides, many of which have antibacterial activity and require the bacterial function of BacA. Although the precise and combined action of several hundred host peptides and BacA has yet to be discovered, similarities, especially to certain insect-bacterium symbioses involving likewise host peptides for manipulation of endosymbionts, suggest convergent evolution. Rhizobium-legume symbiosis provides a rich source of information for understanding host-controlled endosymbiotic life in eukaryotic cells.

  15. Genetic Factors and Host Traits Predict Spore Morphology for a Butterfly Pathogen

    Directory of Open Access Journals (Sweden)

    Jacobus C. de Roode

    2013-08-01

    Full Text Available Monarch butterflies (Danaus plexippus throughout the world are commonly infected by the specialist pathogen Ophryocystis elektroscirrha (OE. This protozoan is transmitted when larvae ingest infectious stages (spores scattered onto host plant leaves by infected adults. Parasites replicate internally during larval and pupal stages, and adult monarchs emerge covered with millions of dormant spores on the outsides of their bodies. Across multiple monarch populations, OE varies in prevalence and virulence. Here, we examined geographic and genetic variation in OE spore morphology using clonal parasite lineages derived from each of four host populations (eastern and western North America, South Florida and Hawaii. Spores were harvested from experimentally inoculated, captive-reared adult monarchs. Using light microscopy and digital image analysis, we measured the size, shape and color of 30 replicate spores per host. Analyses examined predictors of spore morphology, including parasite source population and clone, parasite load, and the following host traits: family line, sex, wing area, and wing color (orange and black pigmentation. Results showed significant differences in spore size and shape among parasite clones, suggesting genetic determinants of morphological variation. Spore size also increased with monarch wing size, and monarchs with larger and darker orange wings tended to have darker colored spores, consistent with the idea that parasite development depends on variation in host quality and resources. We found no evidence for effects of source population on variation in spore morphology. Collectively, these results provide support for heritable variation in spore morphology and a role for host traits in affecting parasite development.

  16. Effect of stiffness and thickness ratio of host plate and piezoelectric patches on reduction of the stress concentration factor

    Science.gov (United States)

    Fesharaki, Javad Jafari; Madani, Seyed Ghasem; Golabi, Sa'id

    2016-09-01

    This paper focuses on the effects of stiffness ratio and thickness ratio on reducing stress concentration factor using piezoelectric patches in a rectangular plate with a hole, as a classical shape. Various locations of actuators and induction of positive/negative strains into the host plate are investigated and the best location of patches is presented. The study investigated the ratio effects and piezoelectric patches bounded on a rectangular host plate having various thicknesses and materials. Results show that the best position of actuators varies based on values of thickness and stiffness ratios of the host plate and piezoelectric patches. Also, the location of maximum stress concentration is transmitted from top and bottom of the hole to another point around the edge by changing the location of the piezoelectric actuators. To verify the results, some experimental tests are applied. The results show good agreement between the finite element analysis and experimental tests.

  17. [Factors influencing research activity of Andalusian nurses and improvement strategies].

    Science.gov (United States)

    López Alonso, Sergio R; Gálvez González, María; Amezcua, Manuel

    2013-04-01

    To identify factors influencing research activity of Andalusian nurses and to find improvement strategies. Qualitative research using SWOT analysis (weaknesses, threats, strengths, opportunities). Nurses were selected deliberately in eight groups according to predetermined criteria. Analysis included categorization and relationship of factors and strategies. 81 participants were included in groups of 7-12 range. 45 categories were identified with 212 factors: 12 weaknesses (50 factors), 10 strengths (44 factors), 12 threats (68 factors) and 11 opportunities (50 factors). In addition, 32 categories were identified with 53 strategies: 14 categories of W-T strategies (42 strategies), 3 categories of S-T strategies (11 strategies), 5 categories of W-O strategies (13 strategies) and 10 categories of S-O strategies (41 strategies). Nurses identified numerous factors, mainly threats. The strategies are focused on W-T but they also suggest many but weak 5-0 strategies due to the low potential of the opportunities and strengths perceived.

  18. Factors influencing adherence among older people with osteoarthritis.

    Science.gov (United States)

    Loew, Laurianne; Brosseau, Lucie; Kenny, Glen P; Durand-Bush, Natalie; Poitras, Stéphane; De Angelis, Gino; Wells, George A

    2016-09-01

    This study aims to identify potential factors that could affect adherence and influence the implementation of an evidence-based structured walking program, among older adults diagnosed with knee osteoarthritis. A total of 69 participants with mild to moderate osteoarthritis of the knee fulfilled an online survey on potential factors that could affect their adherence to an evidence-based structured walking program. Adherence with regard to the influencing factors was explored using a logistic regression model. Results tend to show higher odds of adhering to the evidence-based walking program if the participants were supervised (more than 2.9 times as high), supported by family/friends (more than 3.7 times as high), and not influenced by emotional involvement (more than 11 times as high). The odds of adhering were 3.6 times lower for participants who indicated a change in their medication intake and 3.1 times lower for individuals who considered themselves as less physically active (95 % confidence interval (CI)). Our exploratory findings identified and defined potential adherence factors that could guide health professionals in their practice to better identify positive influences and obstacles to treatment adherence, which would lead to the adoption of a more patient-centered approach. A large-scale study is required to clearly delineate the key factors that would influence adherence. We addressed a new knowledge gap by identifying the main strategies to promote the long-term adherence of community-based walking program.

  19. The Staphylococcus aureus protein Sbi acts as a complement inhibitor and forms a tripartite complex with host complement Factor H and C3b.

    Directory of Open Access Journals (Sweden)

    Katrin Haupt

    2008-12-01

    Full Text Available The Gram-positive bacterium Staphylococcus aureus, similar to other pathogens, binds human complement regulators Factor H and Factor H related protein 1 (FHR-1 from human serum. Here we identify the secreted protein Sbi (Staphylococcus aureus binder of IgG as a ligand that interacts with Factor H by a-to our knowledge-new type of interaction. Factor H binds to Sbi in combination with C3b or C3d, and forms tripartite SbiratioC3ratioFactor H complexes. Apparently, the type of C3 influences the stability of the complex; surface plasmon resonance studies revealed a higher stability of C3d complexed to Sbi, as compared to C3b or C3. As part of this tripartite complex, Factor H is functionally active and displays complement regulatory activity. Sbi, by recruiting Factor H and C3b, acts as a potent complement inhibitor, and inhibits alternative pathway-mediated lyses of rabbit erythrocytes by human serum and sera of other species. Thus, Sbi is a multifunctional bacterial protein, which binds host complement components Factor H and C3 as well as IgG and beta(2-glycoprotein I and interferes with innate immune recognition.

  20. An influence of the copy number of biosynthetic gene clusters on the production level of antibiotics in a heterologous host.

    Science.gov (United States)

    Manderscheid, Niko; Bilyk, Bohdan; Busche, Tobias; Kalinowski, Jörn; Paululat, Thomas; Bechthold, Andreas; Petzke, Lutz; Luzhetskyy, Andriy

    2016-08-20

    Streptomyces albus J1074 is a well-known host for heterologous expression of secondary metabolites. To further increase its potential and to study the influence of cluster multiplication, additional φC31-attachment site was integrated into its genome using a system for transposon mutagenesis. Four secondary metabolite clusters were expressed in strains with different numbers of attachment sites, ranging from one to three copies of the site. Secondary metabolite production was examined and a new compound could be detected, purified and its structure was elucidated.

  1. A survey on critical factors influencing organizational commitment

    Directory of Open Access Journals (Sweden)

    Hamidreza Kheirkhah

    2014-04-01

    Full Text Available Organizational commitment is an important issue and organization attitude has become an area of study among many researchers in the fields of organizational behavior. In fact, there are many studies on human resource management where the effects of organizational commitment on other issues have been investigated and the purpose of this research is to find critical factors influencing on organizational commitment. Based on an exploration of the literature review and interviews, the proposed study of this paper extracts 24 variables and using factor analysis, we select the most important factors, which are grouped in four categories. The implementation of our factor analysis has revealed Affective commitment, Continuous commitment, Moral commitment and Enduring commitment are the most important factors influencing organizational commitment.

  2. A survey on critical factors influencing agricultural insurance

    Directory of Open Access Journals (Sweden)

    Ali Valipour

    2013-01-01

    Full Text Available Agricultural business is a very high-risk job and an increase demand for agricultural products from one side and steady increase in production cost and weather changes, on the other side, have motivated many to use insurance for agricultural products. Insurance plays an important role in influencing crop production and insured satisfaction or farmers. The purpose of this research is to find critical components in agricultural insurance. Based on an exploration of the literature review and interviews, the proposed study of this paper extracts 24 variables and using factor analysis, we select the most important factors, which are grouped in seven categories. The implementation of our factor analysis has revealed uncertainty, moderator, market equilibrium, risky environment, empowering factor, education, training, structural hazards and natural ecosystems as the most important factors influencing agricultural industry.

  3. Influence of host seed on metabolic activity by Enterobacter cloacae in the spermosphere

    Science.gov (United States)

    Little is known regarding the influences of nutrients released from plants on the metabolic activity of colonizing microbes. To gain a better understanding of these influences, we used bioluminescence- and oxygen consumption-based methods to compare bacterial metabolic activity expressed during col...

  4. Microscopy-based Assays for High-throughput Screening of Host Factors Involved in Brucella Infection of Hela Cells.

    Science.gov (United States)

    Casanova, Alain; Low, Shyan H; Emmenlauer, Mario; Conde-Alvarez, Raquel; Salcedo, Suzana P; Gorvel, Jean-Pierre; Dehio, Christoph

    2016-08-05

    Brucella species are facultative intracellular pathogens that infect animals as their natural hosts. Transmission to humans is most commonly caused by direct contact with infected animals or by ingestion of contaminated food and can lead to severe chronic infections. Brucella can invade professional and non-professional phagocytic cells and replicates within endoplasmic reticulum (ER)-derived vacuoles. The host factors required for Brucella entry into host cells, avoidance of lysosomal degradation, and replication in the ER-like compartment remain largely unknown. Here we describe two assays to identify host factors involved in Brucella entry and replication in HeLa cells. The protocols describe the use of RNA interference, while alternative screening methods could be applied. The assays are based on the detection of fluorescently labeled bacteria in fluorescently labeled host cells using automated wide-field microscopy. The fluorescent images are analyzed using a standardized image analysis pipeline in CellProfiler which allows single cell-based infection scoring. In the endpoint assay, intracellular replication is measured two days after infection. This allows bacteria to traffic to their replicative niche where proliferation is initiated around 12 hr after bacterial entry. Brucella which have successfully established an intracellular niche will thus have strongly proliferated inside host cells. Since intracellular bacteria will greatly outnumber individual extracellular or intracellular non-replicative bacteria, a strain constitutively expressing GFP can be used. The strong GFP signal is then used to identify infected cells. In contrast, for the entry assay it is essential to differentiate between intracellular and extracellular bacteria. Here, a strain encoding for a tetracycline-inducible GFP is used. Induction of GFP with simultaneous inactivation of extracellular bacteria by gentamicin enables the differentiation between intracellular and extracellular

  5. Eop1 from a Rubus strain of Erwinia amylovora functions as a host-range limiting factor.

    Science.gov (United States)

    Asselin, J E; Bonasera, J M; Kim, J F; Oh, C-S; Beer, S V

    2011-08-01

    Strains of Erwinia amylovora, the bacterium causing the disease fire blight of rosaceous plants, are separated into two groups based on host range: Spiraeoideae and Rubus strains. Spiraeoideae strains have wide host ranges, infecting plants in many rosaceous genera, including apple and pear. In the field, Rubus strains infect the genus Rubus exclusively, which includes raspberry and blackberry. Based on comparisons of limited sequence data from a Rubus and a Spiraeoideae strain, the gene eop1 was identified as unusually divergent, and it was selected as a possible host specificity factor. To test this, eop1 genes from a Rubus strain and a Spiraeoideae strain were cloned and mutated. Expression of the Rubus-strain eop1 reduced the virulence of E. amylovora in immature pear fruit and in apple shoots. Sequencing the orfA-eop1 regions of several strains of E. amylovora confirmed that forms of eop1 are conserved among strains with similar host ranges. This work provides evidence that eop1 from a Rubus-specific strain can function as a determinant of host specificity in E. amylovora.

  6. FACTORS INFLUENCING BRAND EQUITY OF BALI AS A TOURISM DESTINATION

    Directory of Open Access Journals (Sweden)

    I Ketut Surya Diarta

    2016-03-01

    Full Text Available Globally, competition among tourism destinations is more stringent in getting foreign tourists, including Bali. One effort to win the competition is increasing destination brand equity through maintaining its influencing factors and gaining tourist positive behavior toward destination. This effort, in long run, will increase and stabilize destination revenue and sustainability. This research aims to analyze factors influencing brand equity of Bali as a tourism destination. This research was conducted in Bali’s five major tourism objects. The 240 foreign tourists were chosen as respondents through convenience sampling technique. Data were analyzed using factor analysis. The results showed that factors that significantly influenced Bali brand equity were: symbolic and experiential benefit factor, direct and indirect destinations attributes, destination reliability and tangibility, assurance and empathy, brand destinations recognition and recall, destinations common psychological attributes, destination common functional attributes, unique functional attributes, behavioral loyalty, destination awareness, and attitudinal loyalty. Given the fluctuative nature of brand equity, Bali needs a consistent effort to maintain or to enhance brand equity of Bali as a tourism destination. Maintaining the dominant factors that influence the strength of brand equity can be used as a basis to develop destination branding strategy to expand market segment,  choose the right target market, and anchoring destination position in world market competition.

  7. Factors negatively influencing knowledge sharing in software development

    Directory of Open Access Journals (Sweden)

    Lucas T. Khoza

    2017-01-01

    Full Text Available Background: ‘Knowledge is power’ and software developing organisations are dependent on knowledge to achieve and maintain a competitive advantage. Subsequently, knowledge sharing is a key factor for modern software developing organisations to succeed in today’s competitive environment. For software developing organisations to reach their goals and objectives, knowledge sharing – and in particular the sharing of useful knowledge – needs to be targeted. To promote knowledge sharing, factors influencing knowledge sharing need to be identified and understood.Objective: This study seeks to identify factors that negatively influence knowledge sharing in software development in the developing country context.Method: Expert sampling as a subcategory of purposive sampling was employed to extract information, views and opinions from experts in the field of information and communication technology, more specifically from those who are involved in software development projects. Four Johannesburg-based software developing organisations listed on the Johannesburg Stock Exchange (JSE, South Africa, participated in this research study. Quantitative data were collected using an online questionnaire with closed-ended questions.Results: Findings of this research reveal that job security, motivation, time constraints, physiological factors, communication, resistance to change and rewards are core factors negatively influencing knowledge sharing in software developing organisations.Conclusions: Improved understanding of factors negatively influencing knowledge sharing is expected to assist software developing organisations in closing the gap for software development projects failing to meet the triple constraint of time, cost and scope.

  8. Host specificity in the host-seeking larva of the dipteran parasitoid Mallophora ruficauda and the influence of age on parasitism decisions.

    Science.gov (United States)

    Barrantes, M E; Castelo, M K

    2014-06-01

    Larvae of the robber fly Mallophora ruficauda are ectoparasitoids of white grubs and adults are an important apiculture pest in Argentina. Females oviposit on tall grasses and the second instar larva actively searches and locates hosts. There are nine potential hosts in the distribution area of this parasitoid and Cyclocephala signaticollis (Coleoptera: Scarabaeidae) is the most parasitized in the field. However, M. ruficauda has a certain degree of behavioural flexibility towards different host species, and not being a strict specialist. The conditions under which the parasitoid orientates and accepts different hosts' species are unknown. We studied the host specificity of M. ruficauda towards three species of Cyclocephala genus and we determined whether this specificity depends on larval age. We also evaluated whether larva orientation towards Cyclocephala species changes with chemical cue concentration. We assessed host specificity measuring the orientation and acceptance behaviours towards kairomones extracts and live individuals of Cyclocephala species using M. ruficauda larvae of low and high life expectancy (i.e., young and aged second instar larvae). We observed that young larvae orientated only towards C. signaticollis chemical stimulus, whereas aged larvae orientated also towards C. modesta, and the same was observed with increasing stimuli's concentration. Both young and aged M. ruficauda larvae orientate towards live C. signaticollis and C. putrida species and rejected C. modesta. Also, we found that larvae accepted all Cyclocephala hosts. In conclusion, our results indicate that specificity in the laboratory, observed through host orientation and host acceptance behaviours, depends not only on the availability of host species, but also on the nature of the host's stimuli combined with parasitoid age.

  9. Influence of social factors on lead exposure and child development

    Energy Technology Data Exchange (ETDEWEB)

    Bornschein, R.L.

    1985-10-01

    A brief overview of current views of child development is provided, with particular attention given to the role the child's physical and social environment plays in influencing the developmental process. Examples from the recent literature are used to illustrate how these factors can influence lead exposure and most importantly how they might interact with lead to ameliorate or exacerbate possible lead effects. An example is provided which demonstrates that failure to control adequately and to adjust the data statistically to correct for the influence of these factors can lead one erroneously to attribute cognitive and behavioral changes to lead. Finally, data from the Cincinnati Prospective Lead Study are presented to illustrate the application of structural equation modeling as a means for unraveling the complex web of sociodemographic, environmental and behavioral influences on childhood lead exposure.

  10. ICT Interventions for Girls: Factors Influencing ICT Career Intentions

    Directory of Open Access Journals (Sweden)

    Elena Gorbacheva

    2014-11-01

    Full Text Available Intervention programs aimed at promoting study and work opportunities in the Information and Communications Technology (ICT field to schoolgirls have been encouraged to combat a decline in the interest among girls to study ICT at school. The goal of our study is to investigate the influence of such interventions on schoolgirls’ intentions to choose a career in the ICT field by analysing comprehensive survey data (n = 3577, collected during four interventions in Australia, using the Partial Least Squares method. Our study is also aimed at identifying other factors influencing ICT career intentions. We found that the attitude towards interventions has an indirect influence on ICT career intentions by affecting interest in ICT. Our results also challenge several existing theoretical studies by showing that factors that had previously been suggested as influencers were found to have little or no impact in this study, these being same-sex education and computer usage.

  11. Getting what is served? Feeding ecology influencing parasite-host interactions in invasive round goby Neogobius melanostomus.

    Science.gov (United States)

    Emde, Sebastian; Kochmann, Judith; Kuhn, Thomas; Plath, Martin; Klimpel, Sven

    2014-01-01

    Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus) in the rivers Rhine and Main in Germany. A total of 350 N. melanostomus were sampled between June and October 2011. Gut content analysis revealed a broad prey spectrum, partly reflecting temporal and local differences in prey availability. For the major food type (amphipods), species compositions were determined. Amphipod fauna consisted entirely of non-native species and was dominated by Dikerogammarus villosus in the Main and Echinogammarus trichiatus in the Rhine. However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus. Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main. To analyse infection pathways, we examined 17,356 amphipods and found Pomphorhynchus sp. larvae only in D. villosus in the river Rhine at a prevalence of 0.15%. Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range.

  12. Getting what is served? Feeding ecology influencing parasite-host interactions in invasive round goby Neogobius melanostomus.

    Directory of Open Access Journals (Sweden)

    Sebastian Emde

    Full Text Available Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus in the rivers Rhine and Main in Germany. A total of 350 N. melanostomus were sampled between June and October 2011. Gut content analysis revealed a broad prey spectrum, partly reflecting temporal and local differences in prey availability. For the major food type (amphipods, species compositions were determined. Amphipod fauna consisted entirely of non-native species and was dominated by Dikerogammarus villosus in the Main and Echinogammarus trichiatus in the Rhine. However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus. Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main. To analyse infection pathways, we examined 17,356 amphipods and found Pomphorhynchus sp. larvae only in D. villosus in the river Rhine at a prevalence of 0.15%. Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes may influence host-parasite dynamics of N. melanostomus in its introduced range.

  13. Factors Influencing the Intended Likelihood of Exposing Sexual Infidelity.

    Science.gov (United States)

    Kruger, Daniel J; Fisher, Maryanne L; Fitzgerald, Carey J

    2015-08-01

    There is a considerable body of literature on infidelity within romantic relationships. However, there is a gap in the scientific literature on factors influencing the likelihood of uninvolved individuals exposing sexual infidelity. Therefore, we devised an exploratory study examining a wide range of potentially relevant factors. Based in part on evolutionary theory, we anticipated nine potential domains or types of influences on the likelihoods of exposing or protecting cheaters, including kinship, strong social alliances, financial support, previous relationship behaviors (including infidelity and abuse), potential relationship transitions, stronger sexual and emotional aspects of the extra-pair relationship, and disease risk. The pattern of results supported these predictions (N = 159 men, 328 women). In addition, there appeared to be a small positive bias for participants to report infidelity when provided with any additional information about the situation. Overall, this study contributes a broad initial description of factors influencing the predicted likelihood of exposing sexual infidelity and encourages further studies in this area.

  14. Empirical Analysis on Factors Influencing Distribution of Vegetal Production

    Institute of Scientific and Technical Information of China (English)

    Wenjie; WU

    2015-01-01

    Since the reform and opening-up,there has been a great change in spatial pattern of China’s vegetable production. This paper studied vegetable production in provinces of China in 1978- 2013. From the sequential characteristics,China’s vegetable production area is constantly growing and takes on stage characteristic. From the spatial distribution,China’s vegetable production takes on the trend of " going down the south" and " marching the west". In order to grasp rules of changes of vegetable production and the influence factors,this paper made theoretical and empirical analysis on factors possibly influencing distribution of vegetable production. Results show that major factors influencing distribution of China’s vegetable production include irrigation condition,non-agricultural employment,market demand,knowledge spillover,comparative effectiveness,rural road and government policies.

  15. MOTIVATIONS AND FACTORS INFLUENCING THE DECISION OF ONLINE TRADING

    Directory of Open Access Journals (Sweden)

    Ioana Ancuta IANCU

    2016-12-01

    Full Text Available In this study, using survey data, we explore motivations and factors that influence the Romanian investors to trade online even if they initially traded through a broker. To identify the factors we used secondary sources and for exploring the factors that influence the decision of trading online we used primary data. We find that investors decide to trade online especially because they spend less time, they have an easier access to information (due to the fact that most of the online trading platforms have notifications and alarms for news that can affect the stock market and they know how to use the internet. We discover that only a few investors are influenced by advertising and the fact that it is fashionable to trade online.

  16. Factors influencing the tolerance of flufenacet applications in winter rye

    OpenAIRE

    2016-01-01

    In winter rye which is grown mostly on locations with a lighter soil texture loose silky-bent grass (Apera spica-venti) is a dominate weed grass. Because of increasing herbicide resistance the control of A. spica-venti becomes more difficult. To manage resistant weed grass populations in winter rye flufenacet is a very important active substance. However, the application of flufenacet can lead to substantially culture damage. The influence of different factors influencing the tolerance of ...

  17. Acquired resistance in a weevil to its parasitoid influenced by host plants

    Directory of Open Access Journals (Sweden)

    Stephen Latham Goldson

    2016-08-01

    Full Text Available Field parasitism rates of the Argentine stem weevil Listronotus bonariensis (Kuschel (Coleoptera: Curculionidae by Microctonus hyperodae Loan (Hymenoptera: Braconidae are known to vary according to different host Lolium species that also differ in ploidy. To further investigate this, a laboratory study was conducted to examine parasitism rates on tetraploid Italian L. multiflorum, diploid L. perenne and diploid hybrid L. perenne × L. multiflorum; none of which were infected by Epichloë endophyte. At the same time, the opportunity was taken to compare the results of this study with observations made during extensive laboratory-based research and parasitoid-rearing in the 1990s using the same host plant species. This made it possible to determine whether there has been any change in weevil susceptibility to the parasitoid over a 20 year period in the presence of the tetraploid Italian, diploid perennial and hybrid host grasses that were common to both experiments.The incidence of parasitism in cages, in the presence of these three grasses mirrored what has recently been observed in the field. When caged, weevil parasitism rates in the presence of a tetraploid Italian ryegrass host were significantly higher (75% than rates that occurred in the presence of either the diploid perennial (46% or the diploid hybrid (52% grass, which were not significantly different from each other. This is very different to laboratory parasitism rates in the 1990s when in the presence of both of the latter grasses high rates of parasitism (c. 75% were recorded. These high rates are typical of those still found in both field and caged tetraploid Italian grasses. In contrast, the abrupt decline in weevil parasitism rates points to the possibility of evolved resistance by the weevil to the parasitoid in the diploid and hybrid grasses, but not so in the tetraploid. The orientation of plants in the laboratory cages had no significant effect on parasitism rates under any

  18. [Influence of human gastrointestinal tract bacterial pathogens on host cell apoptosis].

    Science.gov (United States)

    Wronowska, Weronika; Godlewska, Renata; Jagusztyn-Krynicka, Elzbieta Katarzyna

    2005-01-01

    Several pathogenic bacteria are able to trigger apoptosis in the host cell, but the mechanisms by which it occurs differ, and the resulting pathology can take different courses. Induction and/or blockage of programmed cell death upon infection is a result of complex interaction of bacterial proteins with cellular proteins involved in signal transduction and apoptosis. In this review we focus on pro/anti-apoptotic activities exhibited by two enteric pathogens Salmonella enterica, Yersinia spp. and gastric pathogen Helicobacter pylori. We present current knowledge on how interaction between mammalian and bacterial cell relates to the molecular pathways of apoptosis, and what is the role of apoptosis in pathogenesis.

  19. Identification of host cytosolic sensors and bacterial factors regulating the type I interferon response to Legionella pneumophila.

    Directory of Open Access Journals (Sweden)

    Kathryn M Monroe

    2009-11-01

    Full Text Available Legionella pneumophila is a gram-negative bacterial pathogen that replicates in host macrophages and causes a severe pneumonia called Legionnaires' Disease. The innate immune response to L. pneumophila remains poorly understood. Here we focused on identifying host and bacterial factors involved in the production of type I interferons (IFN in response to L. pneumophila. It was previously suggested that the delivery of L. pneumophila DNA to the host cell cytosol is the primary signal that induces the type I IFN response. However, our data are not easily reconciled with this model. We provide genetic evidence that two RNA-sensing proteins, RIG-I and MDA5, participate in the IFN response to L. pneumophila. Importantly, these sensors do not seem to be required for the IFN response to L. pneumophila DNA, whereas we found that RIG-I was required for the response to L. pneumophila RNA. Thus, we hypothesize that bacterial RNA, or perhaps an induced host RNA, is the primary stimulus inducing the IFN response to L. pneumophila. Our study also identified a secreted effector protein, SdhA, as a key suppressor of the IFN response to L. pneumophila. Although viral suppressors of cytosolic RNA-sensing pathways have been previously identified, analogous bacterial factors have not been described. Thus, our results provide new insights into the molecular mechanisms by which an intracellular bacterial pathogen activates and also represses innate immune responses.

  20. Factors influencing consumer behaviour in market vegetables in Yemen

    Directory of Open Access Journals (Sweden)

    Tarish H. Al-Gahaifi

    2011-01-01

    Full Text Available The purpose of the research is to understand factors influencing consumer behaviour when buying vegetables in Republic of Yemen. Data collection was done by structured questionnaire administered through schools, universities, government offices, and markets from 13 provinces in 5 governorates. Random convenience sampling technique was used. Total sample comprised of 463 completed questionnaires which were used for analysis. The respondents were classified into five categories on the base of their monthly income, age, education, gender, and type of settlement. Authors present the factors that can influence significantly this behaviour, e.g. price, quality, the location of seller, habit, personal relationship between consumer and seller, occasions, discount, sorting, word-mouth, time of purchase, the way of products display, and recommendation of friends and families. From the obtained results, it is obvious that there was high influence on the behaviour of Yemeni consumer when buying vegetables for factors price, occasions, discontent, and time of purchase, while factors habit, display, sorting, and the location of seller suggests medium influence, and the influence was low for word-mouth.

  1. Psychosocial factors for influencing healthy aging in adults in Korea.

    Science.gov (United States)

    Han, KyungHun; Lee, YunJung; Gu, JaSung; Oh, Hee; Han, JongHee; Kim, KwuyBun

    2015-03-07

    Healthy aging includes physical, psychological, social, and spiritual well-being in later years. The purpose of this study is to identify the psychosocial factors influencing healthy aging and examining their socio-demographic characteristics. Perceived health status, depression, self-esteem, self-achievement, ego-integrity, participation in leisure activities, and loneliness were identified as influential factors in healthy aging. 171 Korean adults aged between 45 and 77 years-old participated in the study. Self-reporting questionnaires were used, followed by descriptive statistics and multiple regressions as inferential statistical analyses. There were significant differences between participants' general characteristics: age, education, religion, housing, hobby, and economic status. The factors related to healthy aging had positive correlation with perceived health status, self-esteem, self-achievements, and leisure activities, and negative correlation with depression and loneliness. The factors influencing healthy aging were depression, leisure activities, perceived health status, ego integrity, and self-achievements. These factors were able to explain 51.9%. According to the results, depression is the factor with the greatest influence on healthy aging. Perceived health status, ego integrity, self-achievement, self-esteem, participation of leisure activities were also influential on healthy aging as beneficial factors.

  2. [Influence of the sex of the final host on experimental Dipetalonema vitae filariosis in golden hamsters Cricetus auratus (author's transl)].

    Science.gov (United States)

    Reynouard, F; Barrabes, A; Combescot, C

    1979-01-01

    The authors have studied the influence of the sex of the host on experimental Dipetalonema viteae parasitosis in golden hamsters Cricetus auratus. The parasited hamsters are sacrificed fifteen days after testing for microfilarial count, and then the extent of the infestation is measured by counting the number of male worms and female worms. The average level of microfilarial count is significantly higher in male hamsters than in female hamsters. The same applies to the extent of parasitism: the average number of adult worms is higher when parasitosis occurs in males. However, the sex of the hamster has no influence on the proportion of male and female worms present and the degree of microfilarial count, observed in male hamsters seems to result only from the presence in the same of a greater number of worms.

  3. Factors of influence and changes in the tourism consumer behaviour

    Directory of Open Access Journals (Sweden)

    Fratu, D.

    2011-01-01

    Full Text Available Consumer behaviour is a very important aspect to be studied in every marketing activity, therefore in tourism marketing as well. Defining and identifying the factors that influence consumers help in understanding individual needs and buying processes in their whole complexity. Consumers have changed their behaviour over the last two years due to the instability of the economic environment. The author describes in this article the factors which influence consumer behaviour and also presents how it has changed over the past two years.

  4. Host stress physiology and Trypanosoma haemoparasite infection influence innate immunity in the woylie (Bettongia penicillata).

    Science.gov (United States)

    Hing, Stephanie; Currie, Andrew; Broomfield, Steven; Keatley, Sarah; Jones, Krista; Thompson, R C Andrew; Narayan, Edward; Godfrey, Stephanie S

    2016-06-01

    Understanding immune function is critical to conserving wildlife in view of infectious disease threats, particularly in threatened species vulnerable to stress, immunocompromise and infection. However, few studies examine stress, immune function and infection in wildlife. We used a flow cytometry protocol developed for human infants to assess phagocytosis, a key component of innate immunity, in a critically endangered marsupial, the woylie (Bettongia penicillata). The effects of stress physiology and Trypanosoma infection on phagocytosis were investigated. Blood and faecal samples were collected from woylies in a captive facility over three months. Trypanosoma status was determined using PCR. Faecal cortisol metabolites (FCM) were quantified by enzyme-immunoassay. Mean phagocytosis measured was >90%. An interaction between sex and FCM influenced the percentage of phagocytosing leukocytes, possibly reflecting the influence of sex hormones and glucocorticoids. An interaction between Trypanosoma status and FCM influenced phagocytosis index, suggesting that stress physiology and infection status influence innate immunity.

  5. Metabolic Interactions in the Gastrointestinal Tract (GIT: Host, Commensal, Probiotics, and Bacteriophage Influences

    Directory of Open Access Journals (Sweden)

    Luis Vitetta

    2015-12-01

    Full Text Available Life on this planet has been intricately associated with bacterial activity at all levels of evolution and bacteria represent the earliest form of autonomous existence. Plants such as those from the Leguminosae family that form root nodules while harboring nitrogen-fixing soil bacteria are a primordial example of symbiotic existence. Similarly, cooperative activities between bacteria and animals can also be observed in multiple domains, including the most inhospitable geographical regions of the planet such as Antarctica and the Lower Geyser Basin of Yellowstone National Park. In humans bacteria are often classified as either beneficial or pathogenic and in this regard we posit that this artificial nomenclature is overly simplistic and as such almost misinterprets the complex activities and inter-relationships that bacteria have with the environment as well as the human host and the plethora of biochemical activities that continue to be identified. We further suggest that in humans there are neither pathogenic nor beneficial bacteria, just bacteria embraced by those that tolerate the host and those that do not. The densest and most complex association exists in the human gastrointestinal tract, followed by the oral cavity, respiratory tract, and skin, where bacteria—pre- and post-birth—instruct the human cell in the fundamental language of molecular biology that normally leads to immunological tolerance over a lifetime. The overall effect of this complex output is the elaboration of a beneficial milieu, an environment that is of equal or greater importance than the bacterium in maintaining homeostasis.

  6. The Hoopoe's Uropygial Gland Hosts a Bacterial Community Influenced by the Living Conditions of the Bird.

    Directory of Open Access Journals (Sweden)

    Sonia M Rodríguez-Ruano

    Full Text Available Molecular methods have revealed that symbiotic systems involving bacteria are mostly based on whole bacterial communities. Bacterial diversity in hoopoe uropygial gland secretion is known to be mainly composed of certain strains of enterococci, but this conclusion is based solely on culture-dependent techniques. This study, by using culture-independent techniques (based on the 16S rDNA and the ribosomal intergenic spacer region shows that the bacterial community in the uropygial gland secretion is more complex than previously thought and its composition is affected by the living conditions of the bird. Besides the known enterococci, the uropygial gland hosts other facultative anaerobic species and several obligated anaerobic species (mostly clostridia. The bacterial assemblage of this community was largely invariable among study individuals, although differences were detected between captive and wild female hoopoes, with some strains showing significantly higher prevalence in wild birds. These results alter previous views on the hoopoe-bacteria symbiosis and open a new window to further explore this system, delving into the possible sources of symbiotic bacteria (e.g. nest environments, digestive tract, winter quarters or the possible functions of different bacterial groups in different contexts of parasitism or predation of their hoopoe host.

  7. The Hoopoe's Uropygial Gland Hosts a Bacterial Community Influenced by the Living Conditions of the Bird.

    Science.gov (United States)

    Rodríguez-Ruano, Sonia M; Martín-Vivaldi, Manuel; Martín-Platero, Antonio M; López-López, J Pablo; Peralta-Sánchez, Juan M; Ruiz-Rodríguez, Magdalena; Soler, Juan J; Valdivia, Eva; Martínez-Bueno, Manuel

    2015-01-01

    Molecular methods have revealed that symbiotic systems involving bacteria are mostly based on whole bacterial communities. Bacterial diversity in hoopoe uropygial gland secretion is known to be mainly composed of certain strains of enterococci, but this conclusion is based solely on culture-dependent techniques. This study, by using culture-independent techniques (based on the 16S rDNA and the ribosomal intergenic spacer region) shows that the bacterial community in the uropygial gland secretion is more complex than previously thought and its composition is affected by the living conditions of the bird. Besides the known enterococci, the uropygial gland hosts other facultative anaerobic species and several obligated anaerobic species (mostly clostridia). The bacterial assemblage of this community was largely invariable among study individuals, although differences were detected between captive and wild female hoopoes, with some strains showing significantly higher prevalence in wild birds. These results alter previous views on the hoopoe-bacteria symbiosis and open a new window to further explore this system, delving into the possible sources of symbiotic bacteria (e.g. nest environments, digestive tract, winter quarters) or the possible functions of different bacterial groups in different contexts of parasitism or predation of their hoopoe host.

  8. The Hoopoe's Uropygial Gland Hosts a Bacterial Community Influenced by the Living Conditions of the Bird

    Science.gov (United States)

    Rodríguez-Ruano, Sonia M.; Martín-Vivaldi, Manuel; Martín-Platero, Antonio M.; López-López, J. Pablo; Peralta-Sánchez, Juan M.; Ruiz-Rodríguez, Magdalena; Soler, Juan J.; Valdivia, Eva; Martínez-Bueno, Manuel

    2015-01-01

    Molecular methods have revealed that symbiotic systems involving bacteria are mostly based on whole bacterial communities. Bacterial diversity in hoopoe uropygial gland secretion is known to be mainly composed of certain strains of enterococci, but this conclusion is based solely on culture-dependent techniques. This study, by using culture-independent techniques (based on the 16S rDNA and the ribosomal intergenic spacer region) shows that the bacterial community in the uropygial gland secretion is more complex than previously thought and its composition is affected by the living conditions of the bird. Besides the known enterococci, the uropygial gland hosts other facultative anaerobic species and several obligated anaerobic species (mostly clostridia). The bacterial assemblage of this community was largely invariable among study individuals, although differences were detected between captive and wild female hoopoes, with some strains showing significantly higher prevalence in wild birds. These results alter previous views on the hoopoe-bacteria symbiosis and open a new window to further explore this system, delving into the possible sources of symbiotic bacteria (e.g. nest environments, digestive tract, winter quarters) or the possible functions of different bacterial groups in different contexts of parasitism or predation of their hoopoe host. PMID:26445111

  9. Adaptation to toxic hosts as a factor in the evolution of insecticide resistance.

    Science.gov (United States)

    Alyokhin, Andrei; Chen, Yolanda H

    2017-06-01

    Insecticide resistance is a serious economic problem that jeopardizes sustainability of chemical control of herbivorous insects and related arthropods. It can be viewed as a specific case of adaptation to toxic chemicals, which has been driven in large part, but not exclusively, by the necessity for insect pests to tolerate defensive compounds produced by their host plants. Synthetic insecticides may simply change expression of specific sets of detoxification genes that have evolved due to ancestral associations with host plants. Feeding on host plants with more abundant or novel secondary metabolites has even been shown to prime insect herbivores to tolerate pesticides. Clear understanding of basic evolutionary processes is important for achieving lasting success in managing herbivorous arthropods. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Population Distribution and Influencing Factors Based on ESDA

    Institute of Scientific and Technical Information of China (English)

    Lv Chen; Fan Jie; Sun Wei

    2012-01-01

    Based on the exploratory spatial data analysis (ESDA) technique and geographic information system (GIS) platform, with statistic data of counties in 2005, this paper confirms that there is a large population density gap between counties in 2005 because the Gini coefficient is 0.55. Population distribution does not change a lot during the past decades, and the southeast China is still much more densely populated than the northwest China. The global spa- tial autoeorrelation of population distribution is obvious because Moran's I scores 0.42 and local spatial autocorrelation is partly significant. Climate and elevation are still the main natural influ- encing factors. Meanwhile industrial structure and transportation significantly influence population distribution. Different combinations of natural factors have different effects on population distribution. For a long term, climate and terrain factor stability affect population distribution. But its influence will be weakened by progress of technology. Economic development is the main factor that changes population distribution for a short term.

  11. Virulence factors of Actinobacillus pleuropneumoniae involved in colonization, persistence and induction of lesions in its porcine host

    Science.gov (United States)

    Chiers, Koen; De Waele, Tine; Pasmans, Frank; Ducatelle, Richard; Haesebrouck, Freddy

    2010-01-01

    Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. The virulence factors of this microorganism involved in colonization and the induction of lung lesions have been thoroughly studied and some have been well characterized. A. pleuropneumoniae binds preferentially to cells of the lower respiratory tract in a process involving different adhesins and probably biofilm formation. Apx toxins and lipopolysaccharides exert pathogenic effects on several host cells, resulting in typical lung lesions. Lysis of host cells is essential for the bacterium to obtain nutrients from the environment and A. pleuropneumoniae has developed several uptake mechanisms for these nutrients. In addition to persistence in lung lesions, colonization of the upper respiratory tract – and of the tonsils in particular – may also be important for long-term persistent asymptomatic infection. Information on virulence factors involved in tonsillar and nasal cavity colonization and persistence is scarce, but it can be speculated that similar features as demonstrated for the lung may play a role. PMID:20546697

  12. EGFR and EphA2 are host factors for hepatitis C virus entry and possible targets for antiviral therapy.

    Science.gov (United States)

    Lupberger, Joachim; Zeisel, Mirjam B; Xiao, Fei; Thumann, Christine; Fofana, Isabel; Zona, Laetitia; Davis, Christopher; Mee, Christopher J; Turek, Marine; Gorke, Sebastian; Royer, Cathy; Fischer, Benoit; Zahid, Muhammad N; Lavillette, Dimitri; Fresquet, Judith; Cosset, François-Loïc; Rothenberg, S Michael; Pietschmann, Thomas; Patel, Arvind H; Pessaux, Patrick; Doffoël, Michel; Raffelsberger, Wolfgang; Poch, Olivier; McKeating, Jane A; Brino, Laurent; Baumert, Thomas F

    2011-05-01

    Hepatitis C virus (HCV) is a major cause of liver disease, but therapeutic options are limited and there are no prevention strategies. Viral entry is the first step of infection and requires the cooperative interaction of several host cell factors. Using a functional RNAi kinase screen, we identified epidermal growth factor receptor and ephrin receptor A2 as host cofactors for HCV entry. Blocking receptor kinase activity by approved inhibitors broadly impaired infection by all major HCV genotypes and viral escape variants in cell culture and in a human liver chimeric mouse model in vivo. The identified receptor tyrosine kinases (RTKs) mediate HCV entry by regulating CD81-claudin-1 co-receptor associations and viral glycoprotein-dependent membrane fusion. These results identify RTKs as previously unknown HCV entry cofactors and show that tyrosine kinase inhibitors have substantial antiviral activity. Inhibition of RTK function may constitute a new approach for prevention and treatment of HCV infection.

  13. What factors influence UK medical students' choice of foundation school?

    OpenAIRE

    Miah, S.; Pang, K.H.; Rebello, W.; Rubakumar, Z.; Fung, V; Venugopal, S.; Begum, H.

    2017-01-01

    Background: We aimed to identify the factors influencing UK medical student applicants’ choice of foundation school. We also explored the factors that doctors currently approaching the end of their 2-year program believe should be considered. Methods: A cross-sectional study was conducted during the 2013–2014 academic year. An online questionnaire was distributed to 2092 final-year medical students from nine UK medical schools and 84 foundation year-2 (FY2) doctors from eight foundation sc...

  14. Psychosocial factors for influencing healthy aging in adults in Korea

    OpenAIRE

    Han, KyungHun; Lee, YunJung; Gu, JaSung; Oh, Hee; Han, JongHee; Kim, KwuyBun

    2015-01-01

    Background Healthy aging includes physical, psychological, social, and spiritual well-being in later years. The purpose of this study is to identify the psychosocial factors influencing healthy aging and examining their socio-demographic characteristics. Perceived health status, depression, self-esteem, self-achievement, ego-integrity, participation in leisure activities, and loneliness were identified as influential factors in healthy aging. Methods 171 Korean adults aged between 45 and 77 y...

  15. Multilevel factors influencing preterm birth in an urban setting

    Directory of Open Access Journals (Sweden)

    Saba W. Masho

    2014-01-01

    Full Text Available Racial disparity in preterm is a major problem in the US. Although significant strides have been made in identifying some of the risk factors, the complexities between community and individual factors are not understood. This study examines the influence of individual and community level factors affecting preterm birth among Black and White women in an urban setting. A 10-year live birth registry dataset from a mid-sized, racially diverse city was analyzed (N = 30,591. Data were geocoded and merged with block group level Census data. Five hierarchical models were examined using PROC GLIMMIX. Education, illicit drug use, pregnancy complications, previous preterm birth, paternal presence, inadequate and adequate plus prenatal care, and poverty were associated with preterm births in both Blacks and Whites. In Black women, increasing maternal age, maternal smoking, and a previous infant death were significant predictors of preterm births, which was not the case for White women. Residing in medium or high poverty neighborhoods resulted in 19% and 28% higher odds, respectively, of preterm birth for Black women. In addition to individual level factors, neighborhood poverty is an important risk factor influencing preterm birth. It is essential to engage multisectoral agencies in addressing factors influencing preterm birth.

  16. Host and Environmental Factors Modulate the Exposure of Free-Ranging and Farmed Red Deer (Cervus elaphus) to Coxiella burnetii

    OpenAIRE

    González-Barrio, David; Velasco Ávila , Ana Luisa; Boadella, Mariana; Beltrán-Beck, Beatriz; Barasona, José Ángel; Santos, João P. V.; Queirós, João; García-Pérez, Ana L; Barral, Marta; Ruiz-Fons, Francisco

    2015-01-01

    The control of multihost pathogens, such as Coxiella burnetii, should rely on accurate information about the roles played by the main hosts. We aimed to determine the involvement of the red deer (Cervus elaphus) in the ecology of C. burnetii. We predicted that red deer populations from broad geographic areas within a European context would be exposed to C. burnetii, and therefore, we hypothesized that a series of factors would modulate the exposure of red deer to C. burnetii. To test this hyp...

  17. Behavioural risk factors in two generations of non-Western migrants: do trends converge towards the host population?

    OpenAIRE

    Hosper, K.; Nierkens, V.; Nicolaou, M; Stronks, K

    2007-01-01

    Migrant mortality does not conform to a single pattern of convergence towards prevalence rates in the host population. To understand better how migrant mortality develops, it is necessary to further investigate how the underlying behavioural determinants change following migration. We studied whether the prevalence of behavioural risk factors over two generations of Turkish and Moroccan migrants converge towards the prevalence rates in the Dutch population. From a random sample from the popul...

  18. Factors affecting virus dynamics and microbial host-virus interactions in marine environments

    NARCIS (Netherlands)

    Mojica, K.D.A.; Brussaard, C.P.D.

    2015-01-01

    Marine microorganisms constitute the largest percentage of living biomass and serve as the major driving force behind nutrient and energy cycles. While viruses only comprise a small percentage of this biomass (i.e., 5%), they dominate in numerical abundance and genetic diversity. Through host infect

  19. Factors affecting virus dynamics and microbial host-virus interactions in marine environments

    NARCIS (Netherlands)

    Mojica, K.D.A.; Brussaard, C.P.D.

    2014-01-01

    Marine microorganisms constitute the largest percentage of living biomass and serve as the major driving force behind nutrient and energy cycles. While viruses only comprise a small percentage of this biomass (i.e., 5%), they dominate in numerical abundance and genetic diversity. Through host infect

  20. Factors affecting virus dynamics and microbial host-virus interactions in marine environments

    NARCIS (Netherlands)

    Mojica, K.D.A.; Brussaard, C.P.D.

    2014-01-01

    Marine microorganisms constitute the largest percentage of living biomass and serve as the major driving force behind nutrient and energy cycles. While viruses only comprise a small percentage of this biomass (i.e., 5%), they dominate in numerical abundance and genetic diversity. Through host infect

  1. Factors affecting virus dynamics and microbial host-virus interactions in marine environments

    NARCIS (Netherlands)

    Mojica, K.D.A.; Brussaard, C.P.D.

    2015-01-01

    Marine microorganisms constitute the largest percentage of living biomass and serve as the major driving force behind nutrient and energy cycles. While viruses only comprise a small percentage of this biomass (i.e., 5%), they dominate in numerical abundance and genetic diversity. Through host infect

  2. Infrapopliteal Percutaneous Transluminal Balloon Angioplasty: Clinical Results and Influence Factors

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jang Hyeon; Lee, Seung Jin; Jung, Hye Doo; Lim, Jae Hoon; Chang, Nam Kyu; Yim, Nam Yeol; Kim, Jae Kyu [Dept. of Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of); Lee, Keun Bae [Dept. of Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of)

    2011-09-15

    To assess the efficacy of percutaneous transluminal angioplasty (PTA) in patients with infrapopliteal arterial disease, and to determine the influencing factor for prognosis. A total of 55 patients (60 limbs) with infrapopliteal arterial stenosis or occlusion underwent PTA. Atherosclerotic risk factors, clinical symptoms, TransAtlantic Inter-Society Consensus (TASC) classification, and vascular wall calcification were evaluated before PTA. The number of patent infrapopliteal arteries was estimated, and the outcome was evaluated by symptom relief and limb salvage. Technical success was achieved in 53/60 limbs (88.3%) and 81/93 arteries (87.1%), TASC classification (p = 0.038) and vascular calcification (p = 0.002) influenced on technical failure. During follow-up, 26 of 55 limbs (47%) achieved symptom relief and 42/55 limbs (76%) underwent limb salvage. Non-diabetic patients (9/12, 75%) were superior to diabetic patients (17/43, 40%) in terms of symptom relief (p = 0.024). TASC classification and vascular wall calcification influenced on symptom relief and limb salvage. The number of patent infrapopliteal arteries after PTA influenced symptom relief (p < 0.001) and limb amputation (p = 0.003). PTA in patients with chronic critical limb ischemia is worthwhile as a primary treatment. The influence factors should be considered before PTA, and PTA should be performed in as many involved arteries as possible.

  3. Factors that influence the speed of bacterial wood degradation

    NARCIS (Netherlands)

    Klaassen, R.K.W.M.; Overeem, van B.S.

    2012-01-01

    Bacterial wood decay is a serious threat to the many wooden foundation piles in the Netherlands. In order to learn more about the factors that influence the process of decay, approx. 2000 wood samples taken from Amsterdam piles heads were analysed on type and degree of decay and for 59 extracted pil

  4. Modifiable factors influencing relapses and disability in multiple sclerosis

    NARCIS (Netherlands)

    D'hooghe, M. B.; Nagels, G.; Bissay, V.; De Keyser, J.

    2010-01-01

    A growing body of literature indicates that the natural course of multiple sclerosis can be influenced by a number of factors. Strong evidence suggests that relapses can be triggered by infections, the postpartum period and stressful life events. Vaccinations against influenza, hepatitis B and tetan

  5. Factors Influencing the Academic Persistence of College Students with ADHD

    Science.gov (United States)

    Melara, Claudia Alexia

    2012-01-01

    Students with Attention Deficit Hyperactivity Disorder (ADHD) are at greater risk for failing to complete their postsecondary educational degrees than their typical peers. The present qualitative sought to identify factors influencing the academic persistence of students with ADHD in postsecondary settings. Utilizing direct interviews with…

  6. Information Booklets about Cancer: Factors Influencing Patient Satisfaction and Utilisation.

    Science.gov (United States)

    Butow, Phyllis; Brindle, Elizabeth; McConnell, David; Boakes, Robert; Tattersall, Martin

    1998-01-01

    Explored factors influencing patient satisfaction with and utilization of information booklets. Patients (N=36) rated five booklets, and strongly preferred one with a grade-eight reading level. The relationship of preference and recall was investigated. No difference between those who seek or avoid information was found. Additional findings are…

  7. Factors Influencing Consent to Having Videotaped Mental Health Sessions

    Science.gov (United States)

    Ko, Kenton; Goebert, Deborah

    2011-01-01

    Objective: The authors critically reviewed the literature regarding factors influencing consent to having videotaped mental health sessions. Methods: The authors searched the literature in PubMed, PsycINFO, Google Scholar, and Web of Science from the mid-1950s through February 2009. Results: The authors identified 27 studies, of which 19 (73%)…

  8. Identifying factors that influence workplace learning in postgraduate medical education.

    NARCIS (Netherlands)

    Stok-Koch, E.G.H.J.; Bolhuis, S.M.; Koopmans, R.T.C.M.

    2007-01-01

    CONTEXT: In their postgraduate educational programs, residents are immersed in a complex workplace. To improve the quality of the training program, it is necessary to gain insight into the factors that influence the process of learning in the workplace. METHODS: An exploratory study was carried out

  9. The genetic factors influencing the development of trichotillomania

    Indian Academy of Sciences (India)

    Koushik Chatterjee

    2012-08-01

    Trichotillomania (TTM), an obsessive–compulsive spectrum disorder (OCSD), is a psychiatric condition characterized by repetitive hair pulling. Evidence from family and twin studies suggest a heritable link of TTM. Functional polymorphisms in genes involved in neuronal pathways might influence the susceptibility to TTM. This review is an attempt to compile the genetic factors reported to modify the development of TTM.

  10. Abuse of Working Children and Influencing Factors, Turkey

    Science.gov (United States)

    Oncu, Emine; Kurt, Ahmet Oner; Esenay, Figen Isik; Ozer, Fatma

    2013-01-01

    Objective: The study was planned as the research of the kind/kinds of abuse and the factors influencing the abuse that the children under 18 who are working full-time at a workplace and enrolled in a vocational training center subjected to. Method: Questionnaires were administered to 595 apprentices who were attending a vocational training center.…

  11. Social Factors Influencing Participation in Sport for the Deaf.

    Science.gov (United States)

    Stewart, David A.

    1987-01-01

    The article looks at social factors influencing participation in sport by the deaf including communication mode and value orientations of community, family, school, and peers of both the hearing and deaf world. A model for integration of the deaf into sports is offered. (DB)

  12. Factors Influencing Stress, Burnout, and Retention of Secondary Teachers

    Science.gov (United States)

    Fisher, Molly H.

    2011-01-01

    This study examines the stress, burnout, satisfaction, and preventive coping skills of nearly 400 secondary teachers to determine variables contributing to these major factors influencing teachers. Analysis of Variance (ANOVA) statistics were conducted that found the burnout levels between new and experienced teachers are significantly different,…

  13. Investigation and control of factors influencing resistance upset butt welding.

    NARCIS (Netherlands)

    Kerstens, N.F.H.

    2010-01-01

    The purpose of this work is to investigate the factors influencing the resistance upset butt welding process to obtain an understanding of the metal behaviour and welding process characteristics, so that new automotive steels can be welded with reduced development time and fewer failures in

  14. Factors that Influence Informal Learning in the Workplace

    Science.gov (United States)

    Berg, Shelley A.; Chyung, Seung Youn

    2008-01-01

    Purpose: The purpose of this research is to investigate factors that influence informal learning in the workplace and the types of informal learning activities people engage in at work. More specifically, the research examined: the relationship between informal learning engagement and the presence of learning organization characteristics; and…

  15. Factors Influencing the Academic Persistence of College Students with ADHD

    Science.gov (United States)

    Melara, Claudia Alexia

    2012-01-01

    Students with Attention Deficit Hyperactivity Disorder (ADHD) are at greater risk for failing to complete their postsecondary educational degrees than their typical peers. The present qualitative sought to identify factors influencing the academic persistence of students with ADHD in postsecondary settings. Utilizing direct interviews with…

  16. Factors influencing career choice after initial training in surgery.

    LENUS (Irish Health Repository)

    McHugh, Seamus

    2011-03-01

    Irish general surgery faces a recruitment crisis with only 87 of 145 (60%) basic surgical training (BST) places filled in 2009. We assessed basic surgical trainees to identify objective, and potentially modifiable, factors that influence ultimate recruitment into a general surgical career.

  17. Factors Influencing Career Choice of Management Students in India

    Science.gov (United States)

    Agarwala, Tanuja

    2008-01-01

    Purpose: This paper aims to explore the influence of a range of factors on the career choice of management students in India. The importance of different individuals in the family and at work in making career choices among these students is also to be explored. In addition, the study seeks to address the relationship of the cultural values of…

  18. Hepatitus B virus infection : factors influencing the outcome

    NARCIS (Netherlands)

    J. van Hattum (Jan)

    1986-01-01

    textabstractThis study was designed to find correlations between the various courses of disease after hepatitis B virus (HBV) infection and factors that could conceivably have influenced the course of disease. The aim of the study was to find correlations between parameters of viral replication and

  19. Modifiable factors influencing relapses and disability in multiple sclerosis

    NARCIS (Netherlands)

    D'hooghe, M. B.; Nagels, G.; Bissay, V.; De Keyser, J.

    A growing body of literature indicates that the natural course of multiple sclerosis can be influenced by a number of factors. Strong evidence suggests that relapses can be triggered by infections, the postpartum period and stressful life events. Vaccinations against influenza, hepatitis B and

  20. Consumers with Major Depressive Disorder: Factors Influencing Job Placement

    Science.gov (United States)

    Hergenrather, Kenneth C.; Haase, Eileen; Zeglin, Robert J.; Rhodes, Scott D.

    2013-01-01

    The theory of planned behavior (TPB) was applied to study the factors that influence the intention of public rehabilitation placement professionals to place consumers with major depressive disorder (MDD) in jobs. A sample of 108 public rehabilitation placement professionals in the Mid-Atlantic region of the United States completed the MDD…

  1. Investigation and control of factors influencing resistance upset butt welding.

    NARCIS (Netherlands)

    Kerstens, N.F.H.

    2010-01-01

    The purpose of this work is to investigate the factors influencing the resistance upset butt welding process to obtain an understanding of the metal behaviour and welding process characteristics, so that new automotive steels can be welded with reduced development time and fewer failures in producti

  2. Factors Influencing the Occurrence of Adult Agricultural Education Programs.

    Science.gov (United States)

    Christmas, Oren L.; Warmbrod, J. Robert

    A study examined the institutional factors the influence whether or not adult agricultural education programs are offered in high schools. All Ohio secondary schools that offered vocational agriculture programs in agricultural production or farm business management during 1985-1986 (a total of 260 schools) were included in the study. Data were…

  3. Social and Environmental Factors Influencing In-Prison Drug Use

    Science.gov (United States)

    Woodall, James

    2012-01-01

    Purpose: There is a strong political imperative to regard the prison as a key social setting for health promotion, but evidence indicates that drug misuse continues to be a significant issue for many prisoners. This paper aims to examine the social and environmental factors within the setting that influence individuals' drug taking.…

  4. Leadership Factors Influencing the Performance of Educational Institutions. Final Report.

    Science.gov (United States)

    Fiedler, Fred E.

    This document is the summary report of a study having as its main objectives: (1) an intensive study of organizational and group-structural factors influencing the research and teaching effectiveness of individual faculty members and their relations to the students; (2) research investigating the effect of academic area and technology on…

  5. Factors Influencing Latino Participation in Community-Based Diabetes Education

    Science.gov (United States)

    Francis, Sarah L.; Noterman, Amber; Litchfield, Ruth

    2014-01-01

    An Extension diabetes program (DP) was revised for Latinos; however, participation was limited. Factors influencing low participation rates were examined. Five Latinos interested in the DP participated in a focus group discussion. Transcripts were analyzed for themes. Preferred education programs were multi-session, local, group classes led by an…

  6. Hepatitus B virus infection : factors influencing the outcome

    NARCIS (Netherlands)

    J. van Hattum (Jan)

    1986-01-01

    textabstractThis study was designed to find correlations between the various courses of disease after hepatitis B virus (HBV) infection and factors that could conceivably have influenced the course of disease. The aim of the study was to find correlations between parameters of viral replication and

  7. Factors Influencing Student Participation in College Study Abroad Programs

    Science.gov (United States)

    Bandyopadhyay, Soumava; Bandyopadhyay, Kakoli

    2015-01-01

    This paper proposes a theoretical framework to investigate the factors that influence student participation in college study abroad programs. The authors posit that students' general perceptions regarding the study abroad experience and their expectations of intercultural awareness from study abroad programs will impact their perceptions of…

  8. Factors that Influence Women's Technical Skill Development in Outdoor Adventure

    Science.gov (United States)

    Warren, Karen; Loeffler, TA

    2006-01-01

    This article provides a theoretical foundation for understanding women's technical skill development (TSD) in outdoor adventure. An examination of societal and biological factors influencing women's TSD focuses on gender role socialization, sense of competence, technical conditioning, sexism, spatial ability, and risk-taking. The article suggests…

  9. Identifying factors that influence workplace learning in postgraduate medical educaton

    NARCIS (Netherlands)

    L. Stok-Koch; R. Koopmans; Dr. S. Bolhuis

    2007-01-01

    In their postgraduate educational programs, residents are immersed in a complex workplace. To improve the quality of the training program, it is necessary to gain insight into the factors that influence the process of learning in the workplace. An exploratory study was carried out among 56 nursing

  10. Factors influencing adherence to an emergency department national protocol.

    NARCIS (Netherlands)

    Ebben, R.H.A.; Vloet, L.C.M.; Groot, J.M. de; Achterberg, T. van

    2012-01-01

    The objective of this study was to identify factors that influence emergency nurses' adherence to an emergency department national protocol (EDNP). A survey of emergency nurses (n=200) and physicians with medical end responsibility on an emergency department (n=103) was carried out. Emergency nurses

  11. STUDY ON MAJOR FACTORS INFLUENCING SPONTANEOUS COMBUSTION OF COAL

    Institute of Scientific and Technical Information of China (English)

    Deng Jun; Xu Jingcai; Zhang Xinghai

    2000-01-01

    This paper theoretically analyzes major factors influencing spontaneous combustion of coal, such as molecule structure of coal, porosity, temperature, concentration of oxygen, coal thickness, velocity of face advance, and so on; and probes into how they affect the process of spontaneous combustion of coal, which is of momentous significance to predict or control self-ignition of coal.

  12. External and Internal Factors Influencing Happiness in Elite Collegiate Athletes

    Science.gov (United States)

    Denny, Katherine G.; Steiner, Hans

    2009-01-01

    When under conditions of high demand and allostatic load, are happiness and satisfaction in four domains (family, friends, academics, recreation) influenced more by external or internal factors? Do student-athletes who lead exceedingly complicated lives report happiness as a function of athletic achievement or internal disposition? Stanford…

  13. Product development alliances: factors influencing formation and success

    DEFF Research Database (Denmark)

    Olsen, Johanne Rønnow; Harmsen, Hanne; Friis, Alan

    2008-01-01

    Purpose - The objective of this paper is to develop a framework, based on existing literature, for factors influencing the formation and success of product development alliances, and relate this specifically to the food industry. Design/methodology/approach - Case study of a product development a...

  14. Factors influencing beta-amylase activity in sorghum malt

    CSIR Research Space (South Africa)

    Taylor, JRN

    1993-09-01

    Full Text Available An investigation into factors influencing beta-amylase activity in sorghum malt confirmed that ungerminated sorghum grain exhibited essentially no beta-amylase activity. Malted sorghum had beta-amylase activity less than 25% of the level in barley...

  15. INFLUENCE FACTOR ANALYSIS OF CHINESE STUDENTS' LERANING STYLES

    Institute of Scientific and Technical Information of China (English)

    周平

    2009-01-01

    Learning style, aiming at language learner, is a hot issue of second language acquisition. The article first reviews the various definitions of learning style. From the perspective of cognition, three influence factors of Chinese students' learning styles are analyzed. Suggestions are proposed for teachers to help students develop learning styles.

  16. International preferences for pork appearance: II. Factors influencing consumer choice

    NARCIS (Netherlands)

    Ngapo, T.M.; Martin, J.F.; Dransfield, E.

    2007-01-01

    The preference for pork varying in its fat cover, lean colour, marbling and drip differs among countries, but the influence of socio-demographic factors is unknown. In this study of 11,717 consumers from 22 countries, more than 80% of consumers liked pork, thought that pork quality was at least

  17. Identifying factors that influence workplace learning in postgraduate medical education.

    NARCIS (Netherlands)

    Stok-Koch, E.G.H.J.; Bolhuis, S.M.; Koopmans, R.T.C.M.

    2007-01-01

    CONTEXT: In their postgraduate educational programs, residents are immersed in a complex workplace. To improve the quality of the training program, it is necessary to gain insight into the factors that influence the process of learning in the workplace. METHODS: An exploratory study was carried out

  18. Identifying factors that influence workplace learning in postgraduate medical educaton

    NARCIS (Netherlands)

    Stok-Koch, L.; Bolhuis, S.; Koopmans, R.

    2007-01-01

    In their postgraduate educational programs, residents are immersed in a complex workplace. To improve the quality of the training program, it is necessary to gain insight into the factors that influence the process of learning in the workplace. An exploratory study was carried out among 56 nursing h

  19. Consumers with Major Depressive Disorder: Factors Influencing Job Placement

    Science.gov (United States)

    Hergenrather, Kenneth C.; Haase, Eileen; Zeglin, Robert J.; Rhodes, Scott D.

    2013-01-01

    The theory of planned behavior (TPB) was applied to study the factors that influence the intention of public rehabilitation placement professionals to place consumers with major depressive disorder (MDD) in jobs. A sample of 108 public rehabilitation placement professionals in the Mid-Atlantic region of the United States completed the MDD…

  20. FACTORS INFLUENCING THE PURCHASE DECISION OF ORGANIC TOFU

    Directory of Open Access Journals (Sweden)

    Tantry Nugroho

    2015-09-01

    Full Text Available This study aimed to analyze the factors that influence consumers in making the decision to buy organic tofu. The theory of factors that influence the purchasing behavior developed by Kotler was used as the analytical tool, and these factors include cultural factors, social factors, personal factors, psychological factors and purchasing process. These data were collected through interview techniques and analyzed descriptively using multinomial logistic regression. The characteristics of respondents indicated the consumers who never bought organic tofu are mostly at the age of 26-35 years old and university graduates, do not work, have an expenditure from Rp 1 million to Rp 2.5 million, are highly knowledge, and have the highest scores on the perceptions on sustainable and environmentally friendly organic farming, health benefits, and a more expensive price. There are a number of factors that influence consumers in making purchase decisions of organic tofu including age, education, knowledge and product external factors. The consumers who are potentially interested in purchasing the organic tofu are at the age of 36–50 years old, university graduates, highly knowledgeable in food and organic tofu products, because the higher the education and knowledge, the greater the interest in buying the products, and they approved of the external products such as price, advertising, personal selling and places of selling which are also potentially equal. The managerial implications for the business agents of tofu organic product is that they must be more active in assuring the consumers that these products are good for them by creating a blog, an ad in the local paper, or a pamphlet containing information of the product.Keywords: purchase decision, logistic regression, organic tofu product, purchasing interest

  1. Evaluation of the efficacy of factors influencing on marketing SMEs

    Directory of Open Access Journals (Sweden)

    Mona Yaghoubi

    2014-07-01

    Full Text Available This paper presents an empirical investigation to study the effects of different factors influencing on marketing in small and medium enterprises (SMEs in city of Tehran, Iran. The study has been accomplished among 57 SMEs out of 70 active business units who were involved in hand made carpet. The survey uses a questionnaire originally developed by Merrilees et al. (2011 [Merrilees, B., Rundle-Thiele, S., & Lye, A. (2011. Marketing capabilities: Antecedents and implications for B2B SME performance. Industrial Marketing Management, 40(3, 368-375.] to determine the factors influencing on marketing SMEs. Using structural equation modeling, the results of survey indicate that market orientation, management capability, innovation capability and brand capability of SME's marketing performance influence on development of marketing, positively.

  2. The Influence Factors and Mechanism of Societal Risk Perception

    Science.gov (United States)

    Zheng, Rui; Shi, Kan; Li, Shu

    Risk perception is one of important subjects in management psychology and cognitive psychology. It is of great value in the theory and practice to investigate the societal hazards that the public cares a lot especially in Socio-economic transition period. A survey including 30 hazards and 6 risk attributes was designed and distributed to about 2, 485 residents of 8 districts, Beijing. The major findings are listed as following: Firstly, a scale of societal risk perception was designed and 2 factors were identified (Dread Risk & Unknown Risk). Secondly, structural equation model was used to analyze the influence factors and mechanism of societal risk perception. Risk preference, government support and social justice could influence societal risk perception directly. Government support fully moderated the relationship between government trust and societal risk perception. Societal risk perception influenced life satisfaction, public policy preferences and social development belief.

  3. Factors influencing the flavour of game meat: A review.

    Science.gov (United States)

    Neethling, J; Hoffman, L C; Muller, M

    2016-03-01

    Flavour is a very important attribute contributing to the sensory quality of meat and meat products. Although the sensory quality of meat includes orthonasal and retronasal aroma, taste, as well as appearance, juiciness and other textural attributes, the focus of this review is primarily on flavour. The influence of species, age, gender, muscle anatomical location, diet, harvesting conditions, ageing of meat, packaging and storage, as well as cooking method on the flavour of game meat are discussed. Very little research is available on the factors influencing the flavour of the meat derived from wild and free-living game species. The aim of this literature review is thus to discuss the key ante- and post-mortem factors that influence the flavour of game meat, with specific focus on wild and free-living South African game species.

  4. Factors Influencing Renewable Energy Production & Supply - A Global Analysis

    Science.gov (United States)

    Ali, Anika; Saqlawi, Juman Al

    2016-04-01

    Renewable energy is one of the key technologies through which the energy needs of the future can be met in a sustainable and carbon-neutral manner. Increasing the share of renewable energy in the total energy mix of each country is therefore a critical need. While different countries have approached this in different ways, there are some common aspects which influence the pace and effectiveness of renewable energy incorporation. This presentation looks at data and information from 34 selected countries, analyses the patterns, compares the different parameters and identifies the common factors which positively influence renewable energy incorporation. The most successful countries are analysed for their renewable energy performance against their GDP, policy/regulatory initiatives in the field of renewables, landmass, climatic conditions and population to identify the most influencing factors to bring about positive change in renewable energy share.

  5. CONSIDERATIONS REGARDING THE FACTORS THAT INFLUENCE THE PERFORMANCE OF CLUSTER

    Directory of Open Access Journals (Sweden)

    DANA-CODRUŢA DUDĂ-DĂIANU

    2012-05-01

    Full Text Available Economic performance is an objective of each cluster and innovation is a result of future performance indicator. The working paper proposed to measure the cluster performance based on three success factors: competitiveness cluster, cluster growth and the degree of the objectives. Based on Porter's diamond model will be a breakdown of the main factors influencing the development of clusters and their delineation in general and specific factors cluster. In the same time, will analyze the main directions that define performance clusters: access to resources, access to specialized knowledge, entrepreneurship based on the opportunities, collaboration between organizations and cluster specific organizational culture.

  6. A host basal transcription factor is a key component for infection of rice by TALE-carrying bacteria.

    Science.gov (United States)

    Yuan, Meng; Ke, Yinggen; Huang, Renyan; Ma, Ling; Yang, Zeyu; Chu, Zhaohui; Xiao, Jinghua; Li, Xianghua; Wang, Shiping

    2016-07-29

    Transcription activator-like effectors (TALEs) are sequence-specific DNA binding proteins found in a range of plant pathogenic bacteria, where they play important roles in host-pathogen interactions. However, it has been unclear how TALEs, after they have been injected into the host cells, activate transcription of host genes required for infection success. Here, we show that the basal transcription factor IIA gamma subunit TFIIAγ5 from rice is a key component for infection by the TALE-carrying bacterium Xanthomonas oryzae pv. oryzae, the causal agent for bacterial blight. Direct interaction of several TALEs with TFIIAγ5 is required for activation of disease susceptibility genes. Conversely, reduced expression of the TFIIAγ5 host gene limits the induction of susceptibility genes and thus decreases bacterial blight symptoms. Suppression or mutation of TFIIAγ5 can also reduce bacterial streak, another devastating disease of rice caused by TALE-carrying X. oryzae pv. oryzicola. These results have important implications for formulating a widely applicable strategy with which to improve resistance of plants to TALE-carrying pathogens.

  7. Why neurology? Factors which influence career choice in neurology.

    Science.gov (United States)

    Albert, Dara V; Hoyle, Chad; Yin, Han; McCoyd, Matthew; Lukas, Rimas V

    2016-01-01

    To evaluate the factors which influence the decision to pursue a career in neurology. An anonymous survey was developed using a Likert scale to rate responses. The survey was sent to adult and child neurology faculty, residents and fellows, as well as medical students applying for neurology. Descriptive statistics were used to analyse the factors of influence. Respondents were subsequently categorized into pre-neurology trainees, neurology trainees, child neurologists and adult neurologists, and differences between the groups were analysed using Pearson's chi-square test. One hundred and thirty-three anonymous responses were received. The respondents were neurologists across all levels of training and practice. Across all respondents, the most common factor of high importance was intellectual content of specialty, challenging diagnostic problems, type of patient encountered and interest in helping people. Responses were similar across the groups; however, the earliest trainees cited interest in helping people as most important, while those in neurology training and beyond cite intellectual content of the specialty as most important. As trainees transition from their earliest levels of clinical experience into working as residents and faculty, there is a shift in the cited important factors. Lifestyle and financial factors seem to be the least motivating across all groups. Encouragement from peers, mentors, faculty and practicing physicians is considered high influences in a smaller number of neurologists. This may present an opportunity for practicing neurologists to make connections with medical students early in their education in an effort to encourage and mentor candidates.

  8. A Review of Factors Influencing Athletes' Food Choices.

    Science.gov (United States)

    Birkenhead, Karen L; Slater, Gary

    2015-11-01

    Athletes make food choices on a daily basis that can affect both health and performance. A well planned nutrition strategy that includes the careful timing and selection of appropriate foods and fluids helps to maximize training adaptations and, thus, should be an integral part of the athlete's training programme. Factors that motivate food selection include taste, convenience, nutrition knowledge and beliefs. Food choice is also influenced by physiological, social, psychological and economic factors and varies both within and between individuals and populations. This review highlights the multidimensional nature of food choice and the depth of previous research investigating eating behaviours. Despite numerous studies with general populations, little exploration has been carried out with athletes, yet the energy demands of sport typically require individuals to make more frequent and/or appropriate food choices. While factors that are important to general populations also apply to athletes, it seems likely, given the competitive demands of sport, that performance would be an important factor influencing food choice. It is unclear if athletes place the same degree of importance on these factors or how food choice is influenced by involvement in sport. There is a clear need for further research exploring the food choice motives of athletes, preferably in conjunction with research investigating dietary intake to establish if intent translates into practice.

  9. Factors influencing first childbearing timing decisions among men: Path analysis

    Science.gov (United States)

    Kariman, Nourossadat; Amerian, Maliheh; Jannati, Padideh; Salmani, Fatemeh

    2016-01-01

    Background: Factors that influence men’s childbearing intentions have been relatively unexplored in the literature. Objective: This study aimed to determine the influencing factors about the first childbearing timing decisions of men. Materials and Methods: In this cross-sectional study, 300 men who were referred to private and governmental healthcare centers in Shahrood, Iran were randomly recruited from April to September 2014. Data were collected using a demographic questionnaire, the Quality of Life Questionnaire; ENRICH Marital Satisfaction Questionnaire, Synder’s Hope Scale, and the Multidimensional Scale of Perceived Social Support. Results: After removing the statistically insignificant paths, men’s age at marriage had the highest direct effect (β=0.86) on their first childbearing decision. Marital satisfaction (β=-0.09), social support (β=0.06), economic status (β=0.06), and quality of life (β=-0.08) were other effective factors on men’s first childbearing decisions. Moreover, marital satisfaction and social support had significant indirect effects on men’s childbearing decisions (β=-0.04 and -0.01, respectively). Conclusion: Many factors, including personal factors (age at marriage and quality of life), family factors (marital satisfaction), and social factors (social support), can affect men’s decision to have a child. Policymakers are hence required to develop strategies to promote the socioeconomic and family conditions of the couples and to encourage them to have as many children as they desire at an appropriate time. PMID:27738661

  10. Consumer's Online Shopping Influence Factors and Decision-Making Model

    Science.gov (United States)

    Yan, Xiangbin; Dai, Shiliang

    Previous research on online consumer behavior has mostly been confined to the perceived risk which is used to explain those barriers for purchasing online. However, perceived benefit is another important factor which influences consumers’ decision when shopping online. As a result, an integrated consumer online shopping decision-making model is developed which contains three elements—Consumer, Product, and Web Site. This model proposed relative factors which influence the consumers’ intention during the online shopping progress, and divided them into two different dimensions—mentally level and material level. We tested those factors with surveys, from both online volunteers and offline paper surveys with more than 200 samples. With the help of SEM, the experimental results show that the proposed model and method can be used to analyze consumer’s online shopping decision-making process effectively.

  11. Variance of indoor radon concentration: Major influencing factors.

    Science.gov (United States)

    Yarmoshenko, I; Vasilyev, A; Malinovsky, G; Bossew, P; Žunić, Z S; Onischenko, A; Zhukovsky, M

    2016-01-15

    Variance of radon concentration in dwelling atmosphere is analysed with regard to geogenic and anthropogenic influencing factors. Analysis includes review of 81 national and regional indoor radon surveys with varying sampling pattern, sample size and duration of measurements and detailed consideration of two regional surveys (Sverdlovsk oblast, Russia and Niška Banja, Serbia). The analysis of the geometric standard deviation revealed that main factors influencing the dispersion of indoor radon concentration over the territory are as follows: area of territory, sample size, characteristics of measurements technique, the radon geogenic potential, building construction characteristics and living habits. As shown for Sverdlovsk oblast and Niška Banja town the dispersion as quantified by GSD is reduced by restricting to certain levels of control factors. Application of the developed approach to characterization of the world population radon exposure is discussed.

  12. Microevolutionary events involving narrow host plasmids influences local fixation of vancomycin-resistance in Enterococcus populations.

    Directory of Open Access Journals (Sweden)

    Ana R Freitas

    Full Text Available Vancomycin-resistance in enterococci (VRE is associated with isolates within ST18, ST17, ST78 Enterococcus faecium (Efm and ST6 Enterococcus faecalis (Efs human adapted lineages. Despite of its global spread, vancomycin resistance rates in enterococcal populations greatly vary temporally and geographically. Portugal is one of the European countries where Tn1546 (vanA is consistently found in a variety of environments. A comprehensive multi-hierarchical analysis of VRE isolates (75 Efm and 29 Efs from Portuguese hospitals and aquatic surroundings (1996-2008 was performed to clarify the local dynamics of VRE. Clonal relatedness was established by PFGE and MLST while plasmid characterization comprised the analysis of known relaxases, rep initiator proteins and toxin-antitoxin systems (TA by PCR-based typing schemes, RFLP comparison, hybridization and sequencing. Tn1546 variants were characterized by PCR overlapping/sequencing. Intra- and inter-hospital dissemination of Efm ST18, ST132 and ST280 and Efs ST6 clones, carrying rolling-circle (pEFNP1/pRI1 and theta-replicating (pCIZ2-like, Inc18, pHTβ-like, two pRUM-variants, pLG1-like, and pheromone-responsive plasmids was documented. Tn1546 variants, mostly containing ISEf1 or IS1216, were located on plasmids (30-150 kb with a high degree of mosaicism and heterogeneous RFLP patterns that seem to have resulted from the interplay between broad host Inc18 plasmids (pIP501, pRE25, pEF1, and narrow host RepA_N plasmids (pRUM, pAD1-like. TAs of Inc18 (ω-ε-ζ and pRUM (Axe-Txe plasmids were infrequently detected. Some plasmid chimeras were persistently recovered over years from different clonal lineages. This work represents the first multi-hierarchical analysis of VRE, revealing a frequent recombinatorial diversification of a limited number of interacting clonal backgrounds, plasmids and transposons at local scale. These interactions provide a continuous process of parapatric clonalization driving a full

  13. Microevolutionary Events Involving Narrow Host Plasmids Influences Local Fixation of Vancomycin-Resistance in Enterococcus Populations

    Science.gov (United States)

    Freitas, Ana R.; Novais, Carla; Tedim, Ana P.; Francia, María Victoria; Baquero, Fernando; Peixe, Luísa; Coque, Teresa M.

    2013-01-01

    Vancomycin-resistance in enterococci (VRE) is associated with isolates within ST18, ST17, ST78 Enterococcus faecium (Efm) and ST6 Enterococcus faecalis (Efs) human adapted lineages. Despite of its global spread, vancomycin resistance rates in enterococcal populations greatly vary temporally and geographically. Portugal is one of the European countries where Tn1546 (vanA) is consistently found in a variety of environments. A comprehensive multi-hierarchical analysis of VRE isolates (75 Efm and 29 Efs) from Portuguese hospitals and aquatic surroundings (1996–2008) was performed to clarify the local dynamics of VRE. Clonal relatedness was established by PFGE and MLST while plasmid characterization comprised the analysis of known relaxases, rep initiator proteins and toxin-antitoxin systems (TA) by PCR-based typing schemes, RFLP comparison, hybridization and sequencing. Tn1546 variants were characterized by PCR overlapping/sequencing. Intra- and inter-hospital dissemination of Efm ST18, ST132 and ST280 and Efs ST6 clones, carrying rolling-circle (pEFNP1/pRI1) and theta-replicating (pCIZ2-like, Inc18, pHTβ-like, two pRUM-variants, pLG1-like, and pheromone-responsive) plasmids was documented. Tn1546 variants, mostly containing ISEf1 or IS1216, were located on plasmids (30–150 kb) with a high degree of mosaicism and heterogeneous RFLP patterns that seem to have resulted from the interplay between broad host Inc18 plasmids (pIP501, pRE25, pEF1), and narrow host RepA_N plasmids (pRUM, pAD1-like). TAs of Inc18 (ω-ε-ζ) and pRUM (Axe-Txe) plasmids were infrequently detected. Some plasmid chimeras were persistently recovered over years from different clonal lineages. This work represents the first multi-hierarchical analysis of VRE, revealing a frequent recombinatorial diversification of a limited number of interacting clonal backgrounds, plasmids and transposons at local scale. These interactions provide a continuous process of parapatric clonalization driving a full

  14. Influence of Plasmid Type on the Replication of Rhodococcus equi in Host Macrophages.

    Science.gov (United States)

    Willingham-Lane, Jennifer M; Berghaus, Londa J; Giguère, Steeve; Hondalus, Mary K

    2016-01-01

    The soil-dwelling, saprophytic actinomycete Rhodococcus equi is a multihost, facultative intracellular pathogen of macrophages. When inhaled by susceptible foals, it causes severe bronchopneumonia. It is also a pathogen of pigs, which may develop submaxillary lymphadenitis upon exposure. R. equi isolates obtained from foals and pigs possess conjugative plasmids housing a pathogenicity island (PAI) containing a novel family of genes of unknown function called the virulence-associated protein or vap family. The PAI regions of the equine and swine plasmids differ in vap gene composition, with equine isolates possessing six vap genes, including the major virulence determinant vapA, while the PAIs of swine isolates house vapB and five other unique vap genes. Possession of the pVAPA-type virulence plasmid by equine isolates bestows the capacity for intramacrophage replication essential for disease development in vivo. Swine isolates of R. equi are largely unstudied. Here, we show that R. equi isolates from pigs, carrying pVAPB-type plasmids, are able to replicate in a plasmid-dependent manner in macrophages obtained from a variety of species (murine, swine, and equine) and anatomical locations. Similarly, equine isolates carrying pVAPA-type plasmids are capable of replication in swine macrophages. Plasmid swapping between equine and swine strains through conjugation did not alter the intracellular replication capacity of the parental strain, indicating that coevolution of the plasmid and chromosome is not crucial for this attribute. These results demonstrate that while distinct plasmid types exist among R. equi isolates obtained from equine and swine sources, this tropism is not determined by host species-specific intramacrophage replication capabilities. IMPORTANCE This work greatly advances our understanding of the opportunistic pathogen Rhodococcus equi, a disease agent of animals and immunocompromised people. Clinical isolates from diseased foals carry a

  15. Behavioural risk factors in two generations of non-Western migrants: do trends converge towards the host population?

    Science.gov (United States)

    Hosper, Karen; Nierkens, Vera; Nicolaou, Mary; Stronks, Karien

    2007-01-01

    Migrant mortality does not conform to a single pattern of convergence towards prevalence rates in the host population. To understand better how migrant mortality develops, it is necessary to further investigate how the underlying behavioural determinants change following migration. We studied whether the prevalence of behavioural risk factors over two generations of Turkish and Moroccan migrants converge towards the prevalence rates in the Dutch population. From a random sample from the population register of Amsterdam, 291 Moroccan and 505 Turkish migrants, aged 15-30, participated in a structured interview that included questions on smoking, alcohol consumption, physical inactivity and weight/height. Data from the Dutch population were available from Statistics Netherlands. By calculating age-adjusted Odds Ratio's, prevalence rates among both generations were compared with prevalence rates in the host population for men and women separately. We found indications of convergence across generations towards the prevalence rates in the host population for smoking in Turkish men, for overweight in Turkish and Moroccan women and for physical inactivity in Turkish women. Alcohol consumption, however, remained low in all subgroups and did not converge towards the higher rates in the host population. In addition, we found a reversed trend among Turkish women regarding smoking: the second generation smoked significantly more, while the first generation did not differ from ethnic Dutch. In general, behavioural risk factors in two generations of non-Western migrants in the Netherlands seem to converge towards the prevalence rates in the Dutch population. However, some subgroups and risk factors showed a different pattern.

  16. Factors influencing Neurodevelopment after Cardiac Surgery during Infancy

    Directory of Open Access Journals (Sweden)

    Hedwig Hubertine Hövels-Gürich

    2016-12-01

    Full Text Available Short- and long-term neurodevelopmental (ND disabilities with negative impact on psychosocial and academic performance, quality of life and independence in adulthood are known to be the most common sequelae for surviving children after surgery for congenital heart disease (CHD. This article reviews influences and risk factors for ND impairment. For a long time, the search for independent risk factors was focused on the perioperative period and modalities of cardiopulmonary bypass (CPB. CPB operations to ensure intraoperative vital organ perfusion and oxygen supply with or without circulatory arrest or regional cerebral perfusion bear specific risks. Examples for such risks are embolization, deep hypothermia, flow rate, hemodilution, blood gas management, postoperative hyperthermia, systemic-inflammatory response and capillary leak syndrome. However, influences of these procedure-specific risk factors on ND outcome have not been found as strong as expected. Furthermore, modifications have not been found to support the effectiveness of the currently used neuroprotective strategies.Postoperative factors, such as need for extracorporal membrane oxygenation or assist device support and duration of hospital stay, significantly influence ND parameters. On the other hand, the so-called innate, less modifiable patient-specific risk factors have been found to exert significant influences on ND outcomes. Examples are type and severity of CHD, genetic or syndromic abnormalities as well as prematurity and low birth weight.Structural and hemodynamic characteristics of different CHDs are assumed to result in impaired brain growth and delayed maturation with special respect to the white matter. Beginning in the fetal period, this so-called encephalopathy of CHD is suggested a major innate risk factor for pre-, peri- and postoperative additional hypoxic or ischemic brain injury and subsequent ND impairment. Furthermore, MRI studies on brain volume, structure and

  17. Factors Influencing Neurodevelopment after Cardiac Surgery during Infancy

    Science.gov (United States)

    Hövels-Gürich, Hedwig Hubertine

    2016-01-01

    Short- and long-term neurodevelopmental (ND) disabilities with negative impact on psychosocial and academic performance, quality of life, and independence in adulthood are known to be the most common sequelae for surviving children after surgery for congenital heart disease (CHD). This article reviews influences and risk factors for ND impairment. For a long time, the search for independent risk factors was focused on the perioperative period and modalities of cardiopulmonary bypass (CPB). CPB operations to ensure intraoperative vital organ perfusion and oxygen supply with or without circulatory arrest or regional cerebral perfusion bear specific risks. Examples of such risks are embolization, deep hypothermia, flow rate, hemodilution, blood gas management, postoperative hyperthermia, systemic inflammatory response, and capillary leak syndrome. However, influences of these procedure-specific risk factors on ND outcome have not been found as strong as expected. Furthermore, modifications have not been found to support the effectiveness of the currently used neuroprotective strategies. Postoperative factors, such as need for extracorporal membrane oxygenation or assist device support and duration of hospital stay, significantly influence ND parameters. On the other hand, the so-called “innate,” less modifiable patient-specific risk factors have been found to exert significant influences on ND outcomes. Examples are type and severity of CHD, genetic or syndromic abnormalities, as well as prematurity and low birth weight. Structural and hemodynamic characteristics of different CHDs are assumed to result in impaired brain growth and delayed maturation with respect to the white matter. Beginning in the fetal period, this so-called “encephalopathy of CHD” is suggested a major innate risk factor for pre-, peri-, and postoperative additional hypoxic or ischemic brain injury and subsequent ND impairment. Furthermore, MRI studies on brain volume, structure, and

  18. Trypanosome infection establishment in the tsetse fly gut is influenced by microbiome-regulated host immune barriers.

    Directory of Open Access Journals (Sweden)

    Brian L Weiss

    Full Text Available Tsetse flies (Glossina spp. vector pathogenic African trypanosomes, which cause sleeping sickness in humans and nagana in domesticated animals. Additionally, tsetse harbors 3 maternally transmitted endosymbiotic bacteria that modulate their host's physiology. Tsetse is highly resistant to infection with trypanosomes, and this phenotype depends on multiple physiological factors at the time of challenge. These factors include host age, density of maternally-derived trypanolytic effector molecules present in the gut, and symbiont status during development. In this study, we investigated the molecular mechanisms that result in tsetse's resistance to trypanosomes. We found that following parasite challenge, young susceptible tsetse present a highly attenuated immune response. In contrast, mature refractory flies express higher levels of genes associated with humoral (attacin and pgrp-lb and epithelial (inducible nitric oxide synthase and dual oxidase immunity. Additionally, we discovered that tsetse must harbor its endogenous microbiome during intrauterine larval development in order to present a parasite refractory phenotype during adulthood. Interestingly, mature aposymbiotic flies (Gmm(Apo present a strong immune response earlier in the infection process than do WT flies that harbor symbiotic bacteria throughout their entire lifecycle. However, this early response fails to confer significant resistance to trypanosomes. Gmm(Apo adults present a structurally compromised peritrophic matrix (PM, which lines the fly midgut and serves as a physical barrier that separates luminal contents from immune responsive epithelial cells. We propose that the early immune response we observe in Gmm(Apo flies following parasite challenge results from the premature exposure of gut epithelia to parasite-derived immunogens in the absence of a robust PM. Thus, tsetse's PM appears to regulate the timing of host immune induction following parasite challenge. Our results

  19. An empirical investigation on factors influencing choice of foreign market by media firms

    Directory of Open Access Journals (Sweden)

    Ali Akbar Farhangi

    2014-02-01

    Full Text Available This study examines a number of factors suggested in the literature as important determinants of the foreign market selection. Key strategic factors are determined as four groups: host-country characteristics, firm-specific factors, competitive situation and content adaptation. In this study, multiple regression and path analysis are used. To test the model with modeling techniques, the necessary data from 29 media firms were used. It is based on a questionnaire, which has provided several insights into market selection elements. Our findings indicate that all components of the host country, exporting companies, competitive situation and the content adaptation could influence positively the selection of foreign market. The results also indicate that the adaptation of content was the most effective in choosing a foreign market. In addition, cross-cultural adaptation is an important component in selection of foreign markets. The results also suggest that the causal relationships between the independent variables are positive and significant, while the relationship between the content adaptation and the competitive situation has not been confirmed.

  20. An exploration study on factors influencing Iranian food industry

    Directory of Open Access Journals (Sweden)

    Arash Hosseinzadeh

    2013-05-01

    Full Text Available The proposed study of this paper present an empirical investigation to detect important factors impacting on food market using factor analysis. The proposed study designed a questionnaire, distributed among 207 customers who were regular customers of two food chains in city of Tehran, Iran named Shahrvand and Hyperstar. The results of our survey indicate that six major factors including brand loyalty, physical characteristics, pricing effects, performance characteristics, brand relationship and brand position influence food industry, significantly. In terms of the first factor, brand loyalty, “Trust”, “Packaging design characteristics”, “Competitive pricing strategy”, “Stability in quality”, “External relationships” and “Meeting expectations” are important factors in different categories.