WorldWideScience

Sample records for virus agente causal

  1. [Antibibiotic resistance by nosocomial infections' causal agents].

    Science.gov (United States)

    Salazar-Holguín, Héctor Daniel; Cisneros-Robledo, María Elena

    2016-01-01

    The antibibiotic resistance by nosocomial infections (NI) causal agents constitutes a seriously global problematic that involves the Mexican Institute of Social Security's Regional General Hospital 1 in Chihuahua, Mexico; although with special features that required to be specified and evaluated, in order to concrete an effective therapy. Observational, descriptive and prospective study; by means of active vigilance all along 2014 in order to detect the nosocomial infections, for epidemiologic study, culture and antibiogram to identify its causal agents and antibiotics resistance and sensitivity. Among 13527 hospital discharges, 1079 displayed NI (8 %), standed out: the related on vascular lines, of surgical site, pneumonia and urinal track; they added up two thirds of the total. We carried out culture and antibiogram about 300 of them (27.8 %); identifying 31 bacterian species, mainly seven of those (77.9 %): Escherichia coli, Staphylococcus aureus and epidermidis, Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae and Enterobacter cloacae; showing multiresistance to 34 tested antibiotics, except in seven with low or without resistance at all: vancomycin, teicoplanin, linezolid, quinupristin-dalfopristin, piperacilin-tazobactam, amikacin and carbapenems. When we contrasted those results with the recommendations in the clinical practice guides, it aroused several contradictions; so they must be taken with reserves and has to be tested in each hospital, by means of cultures and antibiograms in practically every case of nosocomial infection.

  2. In vitro inhibition of pathogenic Verticillium dahliae , causal agent of ...

    African Journals Online (AJOL)

    In vitro inhibition of pathogenic Verticillium dahliae, causal agent of potato wilt disease in China by Trichoderma isolates. C Xiaojun, S Wongkaew, Y Jie, Y Xuehui, H Haiyong, W Shiping, T Qigqun, W Lishuang, D Athinuwat, N Buensanteai ...

  3. Evidence for Lettuce big-vein associated virus as the causal agent of a syndrome of necrotic rings and spots in lettuce

    NARCIS (Netherlands)

    Verbeek, M.; Dullemans, A.M.; Bekkum, van P.J.; Vlugt, van der R.A.A.

    2013-01-01

    Lettuce big-vein associated virus (LBVaV, genus Varicosavirus) was shown to be responsible for characteristic necrotic symptoms observed in combination with big-vein symptoms in lettuce breeding lines when tested for their susceptibility to lettuce big-vein disease (BVD) using viruliferous Olpidium

  4. Phenotypic and molecular characterisation of the causal agent of ...

    African Journals Online (AJOL)

    A study was carried out to confirm the identity of the causal agent of anthracnose, a major fungal disease of mango in Ghana. Forty-five isolates of the pathogen were obtained from diseased mango plant parts, and were identified using morphological, physiological and molecular methods. The results showed that the ...

  5. Pathogenicity and fungicide sensitivity of the causal agent of ...

    African Journals Online (AJOL)

    Studies were carried out on the stem end rot disease of mango in Ghana. The incidence and severity of the disease were evaluated on mango fruits collected from major mango growing areas of Ghana. The causal agent was isolated on media and identified. The pathogenicity of the fungus and its cross-infection potential ...

  6. New Caledonian crows reason about hidden causal agents.

    Science.gov (United States)

    Taylor, Alex H; Miller, Rachael; Gray, Russell D

    2012-10-02

    The ability to make inferences about hidden causal mechanisms underpins scientific and religious thought. It also facilitates the understanding of social interactions and the production of sophisticated tool-using behaviors. However, although animals can reason about the outcomes of accidental interventions, only humans have been shown to make inferences about hidden causal mechanisms. Here, we show that tool-making New Caledonian crows react differently to an observable event when it is caused by a hidden causal agent. Eight crows watched two series of events in which a stick moved. In the first set of events, the crows observed a human enter a hide, a stick move, and the human then leave the hide. In the second, the stick moved without a human entering or exiting the hide. The crows inspected the hide and abandoned probing with a tool for food more often after the second, unexplained series of events. This difference shows that the crows can reason about a hidden causal agent. Comparative studies with the methodology outlined here could aid in elucidating the selective pressures that led to the evolution of this cognitive ability.

  7. Zika Virus Infection and Microcephaly: Evidence for a Causal Link.

    Science.gov (United States)

    Wang, Jin-Na; Ling, Feng

    2016-10-20

    Zika virus (ZIKV) is a flavivirus related to the Dengue, yellow fever and West Nile viruses. Since the explosive outbreaks of ZIKV in Latin America in 2015, a sudden increase in the number of microcephaly cases has been observed in infants of women who were pregnant when they contracted the virus. The severity of this condition raises grave concerns, and extensive studies on the possible link between ZIKV infection and microcephaly have been conducted. There is substantial evidence suggesting that there is a causal link between ZIKV and microcephaly, however, future studies are warranted to solidify this association. To summarize the most recent evidence on this issue and provide perspectives for future studies, we reviewed the literature to identify existing evidence of the causal link between ZIKV infection and microcephaly within research related to the epidemics, laboratory diagnosis, and possible mechanisms.

  8. Zika Virus Infection and Microcephaly: Evidence for a Causal Link

    Directory of Open Access Journals (Sweden)

    Jin-Na Wang

    2016-10-01

    Full Text Available Zika virus (ZIKV is a flavivirus related to the Dengue, yellow fever and West Nile viruses. Since the explosive outbreaks of ZIKV in Latin America in 2015, a sudden increase in the number of microcephaly cases has been observed in infants of women who were pregnant when they contracted the virus. The severity of this condition raises grave concerns, and extensive studies on the possible link between ZIKV infection and microcephaly have been conducted. There is substantial evidence suggesting that there is a causal link between ZIKV and microcephaly, however, future studies are warranted to solidify this association. To summarize the most recent evidence on this issue and provide perspectives for future studies, we reviewed the literature to identify existing evidence of the causal link between ZIKV infection and microcephaly within research related to the epidemics, laboratory diagnosis, and possible mechanisms.

  9. Stenotrophomonas maltophilia: a new potential biocontrol agent of Ralstonia solanacearum, causal agent of potato brown rot

    NARCIS (Netherlands)

    Messiha, N.A.S.; Diepeningen, van A.D.; Farag, N.S.; Abdallah, S.A.; Janse, J.D.; Bruggen, van A.H.C.

    2007-01-01

    Stenotrophomonas maltophilia was isolated from the rhizosphere of eggplant in the Nile Delta of Egypt, and its antagonistic potential against Ralstonia solanacearum race 3 biovar 2, the causal agent of potato brown rot, was in vitro evaluated on KB agar medium and in vivo on potato plants. In vitro,

  10. Monilophthora roreri, causal agent of cacao frosty pod rot.

    Science.gov (United States)

    Bailey, Bryan A; Evans, Harry C; Phillips-Mora, Wilbert; Ali, Shahin S; Meinhardt, Lyndel W

    2017-12-01

    Taxonomy: Moniliophthora roreri (Cif.) H.C. Evans et al. (1978); Phylum Basidiomycota; Class Agaricomycetes; Order Agaricales; Family Marasmiaceae; Genus Moniliophthora. Biology: M. roreri attacks Theobroma and Herrania species causing frosty pod rot. Theobroma cacao (cacao) is the host of major economic concern. M. roreri is a hemibiotroph with a long biotrophic phase (45-90 days). Spore masses, of apparent asexual origin, are produced on the pod surface after initiation of the necrotrophic phase. Spores are spread by wind, rain and human activity. Symptoms of the biotrophic phase can include necrotic flecks and, in some cases, pod malformation, but pods otherwise remain asymptomatic. Relationship to Moniliophthora perniciosa. M. roreri and Moniliophthora perniciosa, causal agent of witches's broom disease of cacao, are closely related. Their genomes are similar, including many of the genes they carry considered important in the disease process. M. perniciosa, also a hemibiotroph, has a typical basidiomycete lifestyle and morphology, forming clamp connections and producing mushrooms. Basidiospores infect meristematic tissues including flower cushions, stem tips, and pods. M. roreri does not form clamp connections or mushrooms and infects pods only. Both pathogens are limited to the Western Hemisphere and are a threat to cacao production around the world. Agronomic importance: Disease losses due to frosty pod rot can reach 90% and result in field abandonment. M. roreri remains in the invasive phase in the Western Hemisphere not having reached Brazil, some islands within the Caribbean, and a few specific regions within otherwise invaded countries. The disease can be managed by a combination of cultural (for example maintaining tree height and removing infected pods) and chemical methods. These methods benefit from regional application but can be cost prohibitive. Breeding for disease resistance offers the greatest potential for frosty pod rot management and new

  11. Isolation of Clostridium perfringens, Causal agents of necrotic enteritis in chickens

    OpenAIRE

    Miah, M. S.; Asaduzzaman, M.; Sufian, M. A.; Hossain, M. M.

    2011-01-01

    The present study was conducted to isolate the causal agent of necrotic enteritis (NE) from broiler chickens. A total of 50 jejunal samples from necropsied broiler chickens were collected for isolation of Clostridium perfringens, the causal agent of NE. The novel method for isolation of Clostridium perfringens was stab culture in association with pouring of olive oil on the surface of the stab culture. The collected samples in nutrient broth were kept in a candle jar and incubated for 24 hrs ...

  12. The causal direction in the association between respiratory syncytial virus hospitalization and asthma

    DEFF Research Database (Denmark)

    Stensballe, Lone Graff; Simonsen, Jacob Brunbjerg; Thomsen, Simon Francis

    2009-01-01

    BACKGROUND: Earlier studies have reported an increased risk of asthma after respiratory syncytial virus (RSV) hospitalization. Other studies found that asthmatic disposition and propensity to wheeze increase the risk of RSV hospitalization. OBJECTIVE: The current study examined the causal direction...

  13. Canine Myiasis and Its Causal Agents in Northeastern Iran

    Directory of Open Access Journals (Sweden)

    Ali MOSHAVERINIA

    2016-03-01

    Full Text Available Background: Myiasis is defined as the infestation of live human and vertebrate animals with dipterous larvae for a certain period. There are reports indicating that dogs are the most common species affected by myiasis. This study was conducted to identify myiasis-causing flies in owned and stray dogs in Mashhad (Northeastern Iran. Methods: A total of 435 owned dogs and 800 stray dogs were examined for myia­sis. Myiasis cases were cured and fly larvae were identified by microscopy using the relevant standard identification keys.Results: Ten out of 435 owned dogs (2.29 % and 18 out of 800 stray dogs (2.25 % had myiasis. The causative agents of myiasis in dogs based on their fre­quencies were as follows: Wohlfahrtia magnifica (50%, Lucilia sericata (28.57% and Chrysomya albiceps (21.42%.Conclusion: W. magnifica was the most important myiasis-causing fly among the dogs sampled here, sometimes causing very serious damages. However, when treatment was given early enough, the larvae removed and the wound disinfected, the animals usually made a full recovery.

  14. In vitro evidence for sexual reproduction in Venturia effusa, causal agent of pecan scab

    Science.gov (United States)

    Venturia effusa is the causal agent of pecan scab, the most prevalent disease of pecan in the southeastern US. Venturia effusa is currently only known to reproduce asexually, yet the genetic diversity among populations of pecan scab suggest it is a sexually reproducing pathogen. Analysis of the mati...

  15. Structure elucidation and stereoselective total synthesis of pavettamine, the causal agent of gousiekte

    CSIR Research Space (South Africa)

    Bode, ML

    2010-03-01

    Full Text Available The structure elucidation of a novel natural product pavettamine (1), the causal agent of the plant toxicosis gousiekte, is reported. The structure was defined by analysis of NMR and MS data and the relative configuration followed from the 13C NMR...

  16. Draft Genome Sequence of Cercospora arachidicola, Causal Agent of Early Leaf Spot in Peanuts.

    Science.gov (United States)

    Orner, Valerie A; Cantonwine, Emily G; Wang, Xinye Monica; Abouelleil, Amr; Bochicchio, James; Nusbaum, Chad; Culbreath, Albert K; Abdo, Zaid; Arias, Renee S

    2015-11-05

    Cercospora arachidicola, causal agent of early leaf spot, is an economically important peanut pathogen. Lack of genetic information about this fungus prevents understanding the role that potentially diverse genotypes may have in peanut breeding programs. Here, we report for the first time a draft genome sequence of C. arachidicola. Copyright © 2015 Orner et al.

  17. Viruses and human cancer: from detection to causality.

    Science.gov (United States)

    Sarid, Ronit; Gao, Shou-Jiang

    2011-06-28

    The study of cancer is incomplete without taking into consideration of tumorigenic viruses. Initially, searches for human cancer viruses were fruitless despite an expansion of our knowledge in the same period concerning acute-transforming retroviruses in animals. However, over the last 40 years, we have witnessed rapid progress in the tumor virology field. Currently, acknowledged human cancer viruses include Epstein-Barr virus, hepatitis B virus, hepatitis C virus, high-risk human papilloma viruses, human T-cell lymphotropic virus type 1 and Kaposi's sarcoma-associated herpesvirus. Extensive epidemiological and mechanistic studies have led to the development of novel preventive and therapeutic approaches for managing some of these infections and associated cancers. In addition, recent advances in molecular technologies have enabled the discovery of a new potential human tumor virus, Merkel cell polyomavirus, but its association with cancer remains to be validated. It is anticipated that in the next few decades many additional human cancer viruses will be discovered and the mechanisms underlying viral oncogenesis delineated. Thus, it can be expected that better tools for preventing and treating virus-associated cancer will be available in the near future. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  18. Antagonistic activity Trichoderma harzianum Rifai on the causal agent of rice blast (Pyricularia grisea Sacc.

    Directory of Open Access Journals (Sweden)

    Ernesto Juniors Pérez Torres

    2017-10-01

    Full Text Available With the objective to evaluate the antagonistic activity of T. harzianum (strain A-34 on the causal agent of rice blast (P. grisea, were developed several in vitro experiments. It was evaluated the biocontrol mechanisms such as competition through mounted the percent inhibition of radial growth of hyphae of P. grisea from 24 to 240 hours and the antagonistic capacity. In addition, was evaluated micoparasitism to inclination the observation of events Microscopy winding, penetration, vacuolization, lysis, and antibiosis by observing 24 hours a confrontation between the hyphae of the phytopathogenic fungus and biological control agent. It was obtained at 120 hours 100 % inhibition of micelial growth of causal agent, what corresponded with the degree 1 of antagonistic capacity (scale and is recorded as a hyperparasitic action on P. grisea. It was evidenced an antibiotic effect of metabolites produced by T. harzianum (strain A-34 to 24 hours of confrontation, where there was time interaction between the hyphae of microorganisms with 14,3 % inhibition, also was evidence the micoparasitism events by penetration, vacuolization and lysis in the cells of phytopathogenic fungus. These results demonstrated the ability of T. harzianum (strain A-34 on causal agent of rice blast (P. grisea.

  19. Occupational Asthma: New Low-Molecular-Weight Causal Agents, 2000–2010

    Directory of Open Access Journals (Sweden)

    J. A. Pralong

    2012-01-01

    Full Text Available Background. More than 400 agents have been documented as causing occupational asthma (OA. The list of low-molecular-weight (LMW agents that have been identified as potential causes of OA is constantly expanding, emphasizing the need to continually update our knowledge by reviewing the literature. Objective. The objective of this paper was to identify all new LMW agents causing occupational asthma reported during the period 2000–2010. Methods. A Medline search was performed using the keywords occupational asthma, new allergens, new causes, and low-molecular-weight agents. Results. We found 39 publications describing 41 new LMW causal agents, which belonged to the following categories: drugs (n=12, wood dust (n=11, chemicals (n=8, metals (n=4, biocides (n=3, and miscellaneous (n=3. The diagnosis of OA was confirmed through SIC for 35 of 41 agents, peak expiratory flow monitoring for three (3 agents, and the clinical history alone for three (3 agents. Immunological tests provided evidence supporting an IgE-mediated mechanism for eight (8 (20% of the newly described agents. Conclusion. This paper highlights the importance of being alert to the occurrence of new LMW sensitizers, which can elicit OA. The immunological mechanism is explained by a type I hypersensitivity reaction in 20% of all newly described LMW agents.

  20. Sugarcane mosaic virus: The causal agent of mosaic disease on ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... substrates BCIP/NBT used according to the manufacturer's instructions. Reverse Transcription-Polymerase Chain Reaction (RT-PCR). For nucleic acid extraction and Reverse Transcription-Polymerase. Chain Reaction (RT-PCR), the total nucleic acids were extracted from the frozen infected leaves from ...

  1. Cristulariella depraedans as causal agent of leaf spots of maple and other trees and shrubs

    Directory of Open Access Journals (Sweden)

    Tomasz Kowalski

    2013-12-01

    Full Text Available Results of the first studies in Poland on Cristulariella depraedans, the causal agent of necroses on tree and shrub leaves, are presented. The fungus was recorded on Acer platanoides, A. pseudoplatanus and eight other species of trees and shrubs, including Corylus avellana, Fagus sylvatica, Lonicera xylosteum and Padus avium that were not previously known as hosts of the fungus. The disease symptoms, which depend on the host plant species, the size and number of necrotic lesions on leaves, and the morphological features of the fungal propagules were characterized.

  2. Molecular Detection of Monilinia fructigena as Causal Agent of Brown Rot on Quince

    Directory of Open Access Journals (Sweden)

    Jovana Hrustić

    2012-01-01

    Full Text Available Species of the genus Monilinia are important causal agents of fruit rot on pome and stone fruits in Serbia. The pathogen is very harmful, especially on small properties and cottage plantations where intensive control measures are not applied. Quince is importanthost for the pathogens of this genus. During spring 2010, intensive occurrence of mummified fruits overwintering on branches of the quince was observed. The pathogen was isolated using standard phytopathological methods. Pathogenicity of eight obtained isolates was tested by artificial inoculation of injured apple fruits. Identification was performed according to pathogenic, morphological and ecological properties, and was confirmed by Multiplex polimeraze chain reaction, PCR. All the isolates studied caused brown rot on inoculated apple fruits. The isolates form light yellow colonies with lobate margins,with single-celled, transparent, elliptical or oval conidia in chains, regardless temperature or light presence. Sclerotia are observed in 14 days old cultures. The highest growth rate of most of the isolates is at 27°C and in dark. Based on studied pathogenic, morphological and ecological characteristics, it was found that the Monilinia fructigena is causal agent of brown rot of quince. Using specific primers (MO368-5, MO368-8R, MO368-10R, Laxa-R2for detection of Monilinia species in Multiplex PCR reaction, the expected fragment 402 bp in size was amplified, which confirmed that the studied isolates belonged to the speciesM. fructigena.

  3. Zika Virus and Guillain?Barre Syndrome: Is There Sufficient Evidence for Causality?

    OpenAIRE

    Leis, A. Arturo; Stokic, Dobrivoje S.

    2016-01-01

    Worldwide concern over Zika virus causing Guillain–Barre syndrome (GBS) soared after recent reports that Zika-related weakness was due to GBS. A global strategic response plan was initiated with recommendations for at-risk countries to prepare for GBS. This plan has major economic implications, as nations with limited resources struggle to implement costly immunotherapy. Since confirmation of causality is prerequisite to providing specific management recommendations, it is prudent to review d...

  4. Characteristics of winter wheat varieties for resistance to causal agents and pests

    Directory of Open Access Journals (Sweden)

    Г. М. Ковалишина

    2016-02-01

    Full Text Available Purpose. Studying and identifying winter wheat varieties that are resistant to causal agents of major diseases and pests. Methods. Laboratory analysis, field study. Results. On artificial infection backgrounds of causal agents such varieties as ‘Smuhlianka’, ‘Svitanok Myronivskyi’, ‘Berehynia Myronіvska’, ‘Horlytsia Myronіvska’ have shown high level of resistance to brown rust; ‘Svitanok Myronivskyi’, ‘Berehynia Myronіvska’ – to powdery mildew; ‘Smuhlianka’ – to covered smut. Varieties ‘Voloshkova’, ‘Yuviliar Myronivskyi’, ‘Myrliena’, ‘Oberih Myronivskyi’, ‘Kolos Myronivschyny’, ‘Lehenda Myronivska’ had medium resistance to Septoria leaf blotch; ‘Smuhlianka’, ‘Myrliena’, ‘Oberih Myronivskyi’, ‘Berehynia Myronіvska’, ‘Horlytsia Myronіvska’, ‘Myronivska storichna’ – to Fusarium head blight; ‘Myronіvska 65’, ‘Smuhlianka’, ‘Lehenda Myronivska’, ‘Berehynia Myronіvska’ – to root rots. Among the varieties studied, there were those with group resistance to diseases: ‘Voloshkova’, ‘Myrliena’, ‘Yuviliar Myronivskyi’, ‘Oberih Myronivskyi’, ‘Bohdana’, ‘Myronivska storichna’, ‘Ekonomka’, ‘Svitanok Myronivskyi’, ‘Berehynia Myronіvska’, ‘Horlytsia Myronіvska’, ‘Smuhlianka’. Varieties bred at the V. M. Remeslo Myronivka Institute of Wheat are distinguished by pest resistance. During autumn tillering phase of winter wheat the smallest number of large cereal aphids was observed in varieties ‘Smuhlianka’ and ‘Myronivska storichna’, leafhoppers – in varieties ‘Smuhlianka’, ‘Myrliena’, ‘Yuviliar Myronivskyi’. The slight population of thrips in the phase of earing was marked in the variety ‘Kolos Myronivschyny’, in the milk-ripe stage the smallest number of larvae per ear was detected in varieties ‘Smuhlianka’, ‘Voloshkova’, ‘Kolos Myronivschyny’. Varieties

  5. Agents and Patients in Physical Settings: Linguistic Cues Affect the Assignment of Causality in German and Tongan

    Directory of Open Access Journals (Sweden)

    Andrea Bender

    2017-07-01

    Full Text Available Linguistic cues may be considered a potent tool for focusing attention on causes or effects. In this paper, we explore how different cues affect causal assignments in German and Tongan. From a larger screening study, two parts are reported here: Part 1 dealt with syntactic variations, including word order (agent vs. patient in first/subject position and case marking (e.g., as ergative vs. non-ergative in Tongan depending on verb type (transitive vs. intransitive. For two physical settings (wood floating on water and a man breaking a glass, participants assigned causality to the two entities involved. In the floating setting, speakers of the two languages were sensitive to syntactic variations, but differed in the entity regarded as causative. In the breaking setting, the human agent was uniformly regarded as causative. Part 2 dealt with implicit verb causality. Participants assigned causality to subject or object of 16 verbs presented in minimal social scenarios. In German, all verbs showed a subject (agent focus; in Tongan, the focus depended on the verb; and for nine verbs, the focus differed across languages. In conclusion, we discuss the question of domain-specificity of causal cognition, the role of the ergative as causal marker, and more general differences between languages.

  6. Agents and Patients in Physical Settings: Linguistic Cues Affect the Assignment of Causality in German and Tongan.

    Science.gov (United States)

    Bender, Andrea; Beller, Sieghard

    2017-01-01

    Linguistic cues may be considered a potent tool for focusing attention on causes or effects. In this paper, we explore how different cues affect causal assignments in German and Tongan. From a larger screening study, two parts are reported here: Part 1 dealt with syntactic variations, including word order (agent vs. patient in first/subject position) and case marking (e.g., as ergative vs. non-ergative in Tongan) depending on verb type (transitive vs. intransitive). For two physical settings (wood floating on water and a man breaking a glass), participants assigned causality to the two entities involved. In the floating setting, speakers of the two languages were sensitive to syntactic variations, but differed in the entity regarded as causative. In the breaking setting, the human agent was uniformly regarded as causative. Part 2 dealt with implicit verb causality. Participants assigned causality to subject or object of 16 verbs presented in minimal social scenarios. In German, all verbs showed a subject (agent) focus; in Tongan, the focus depended on the verb; and for nine verbs, the focus differed across languages. In conclusion, we discuss the question of domain-specificity of causal cognition, the role of the ergative as causal marker, and more general differences between languages.

  7. Retargeting of viruses to generate oncolytic agents

    NARCIS (Netherlands)

    Verheije, M.H.; Rottier, P.J.M.

    2012-01-01

    Oncolytic virus therapy is based on the ability of viruses to effectively infect and kill tumor cells without destroying the normal tissues. While some viruses seem to have a natural preference for tumor cells, most viruses require the modification of their tropism to specifically enter and

  8. ‘Candidatus Liberibacter asiaticus’, Causal Agent of Citrus Huanglongbing, Is Reduced by Treatment with Brassinosteroids

    Science.gov (United States)

    Hernández, Ingrid; Portieles, Roxana; Rodríguez García, Mayra; López, Yunior; Aranguren, Miguel; Alonso, Eugenio; Delgado, Roger; Luis, Maritza; Batista, Lochy; Paredes, Camilo; Rodríguez, Meilyn; Pujol, Merardo; Ochagavia, María Elena; Falcón, Viviana; Terauchi, Ryohei; Matsumura, Hideo; Ayra-Pardo, Camilo; Llauger, Raixa; Pérez, María del Carmen; Núñez, Mirian; Borrusch, Melissa S.; Walton, Jonathan D.; Silva, Yussuan; Pimentel, Eulogio; Borroto, Carlos; Borrás-Hidalgo, Orlando

    2016-01-01

    Huanglongbing (HLB) constitutes the most destructive disease of citrus worldwide, yet no established efficient management measures exist for it. Brassinosteroids, a family of plant steroidal compounds, are essential for plant growth, development and stress tolerance. As a possible control strategy for HLB, epibrassinolide was applied to as a foliar spray to citrus plants infected with the causal agent of HLB, ‘Candidatus Liberibacter asiaticus’. The bacterial titers were reduced after treatment with epibrassinolide under both greenhouse and field conditions but were stronger in the greenhouse. Known defense genes were induced in leaves by epibrassinolide. With the SuperSAGE technology combined with next generation sequencing, induction of genes known to be associated with defense response to bacteria and hormone transduction pathways were identified. The results demonstrate that epibrassinolide may provide a useful tool for the management of HLB. PMID:26731660

  9. Microsatellite isolation and characterization for Colletotrichum spp, causal agent of anthracnose in Andean blackberry.

    Science.gov (United States)

    Marulanda, M L; López, A M; Isaza, L; López, P

    2014-09-26

    The genus Colletotrichum, comprised of pathogenic fungi that affect plants grown worldwide, causes the disease known as anthracnose in several fruit and vegetable species. Several studies conducted on plants have shown that the disease is characterized by the presence of one or several species of the fungus attacking the fruit or other organs of the same host. To develop and implement effective control strategies, it is vital to understand the genetic structure of the fungus in agricultural systems, identify associated Colletotrichum species, and define the subpopulations responsible for the disease. Molecular tools were accordingly developed to characterize genotypic populations of Colletotrichum spp, causal agent of anthracnose in commercial crops of Andean blackberry (Rubus glaucus Benth.). A microsatellite-enriched library for Colletotrichum gloeosporioides was developed to identify and characterize microsatellite loci among isolates collected in R. glaucus plantations. Thirty microsatellites were developed and tested in 36 isolates gathered from eight different blackberry-production areas of Colombia. Ten pairs of microsatellites were polymorphic.

  10. 'Candidatus Liberibacter asiaticus', Causal Agent of Citrus Huanglongbing, Is Reduced by Treatment with Brassinosteroids.

    Directory of Open Access Journals (Sweden)

    Eduardo Canales

    Full Text Available Huanglongbing (HLB constitutes the most destructive disease of citrus worldwide, yet no established efficient management measures exist for it. Brassinosteroids, a family of plant steroidal compounds, are essential for plant growth, development and stress tolerance. As a possible control strategy for HLB, epibrassinolide was applied to as a foliar spray to citrus plants infected with the causal agent of HLB, 'Candidatus Liberibacter asiaticus'. The bacterial titers were reduced after treatment with epibrassinolide under both greenhouse and field conditions but were stronger in the greenhouse. Known defense genes were induced in leaves by epibrassinolide. With the SuperSAGE technology combined with next generation sequencing, induction of genes known to be associated with defense response to bacteria and hormone transduction pathways were identified. The results demonstrate that epibrassinolide may provide a useful tool for the management of HLB.

  11. Identification and Control of Cladobotryum spp., Causal Agents of Cobeweb Disease of Cultivated Mushroom

    Directory of Open Access Journals (Sweden)

    Ivana Potočnik

    2009-01-01

    Full Text Available Cladobotryum spp. are causal agents of cobweb disease, one of the most serious diseases of cultivated mushroom (Agaricus bisporus (Lange Imbach in Serbia and worldwide, which affects product quality and yield. The disease symptoms are: cottony fluffy white oryellowish to pink colonies on mushroom casing, rapid colonization of casing surface, covering of host basidiomata by mycelia, and their decay. Prochloraz-Mn has been officially recommended for mushroom cultivation in EU countries. However, inefficiency of prochloraz-Mn has been noted at a level of spotting symptoms of cobweb disease. With regard to cases of resistance evolution and a general threat to the environment and human health, special attention should be focused on good programmes of hygiene, and inventing and developing alternative methods of disease control.

  12. Integrated Management of Causal Agents of Postharvest Fruit Rot of Apple

    Directory of Open Access Journals (Sweden)

    Mila Grahovac

    2011-01-01

    Full Text Available One of the major causes of poor quality and fruit loss (during storage and transportare diseases caused by phytopathogenic fungi. Economic losses which are the consequenceof the phytopathogenic fungus activity after harvest exceed the losses in the field.Themost important postharvest fungal pathogens of apple fruits are: Botrytis cinerea Pers. exFr., Penicillium expansum (Lk. Thom., Cryptosporiopsis curvispora (Peck. Grem., Colletotrichumgloeosporioides (Penz. Sacc., Monilinia sp., Gloeosporium album Osterw, Alternaria alternata(Fr. Keissler, Cladosporium herbarium Link., Cylindrocarpon mali (Alles. Wollenw., Stemphyliumbotryosum Wallr. The use of available protection technologies can significantly reducelosses caused by pathogens in storage. The concept of integrated pest management (IPMin apple fruits i.e. sustainable approach in control of causal agents of postharvest fruit rot,using cultural, physical, biological and chemical measures, to minimize economic, healthand risks to consumers and environment, is presented in the paper.

  13. Molecular identification of pathogenic Fusarium species, the causal agents of tomato wilt in western Iran

    Directory of Open Access Journals (Sweden)

    Chehri Khosrow

    2016-04-01

    Full Text Available Fusarium species are causal agents of fungal diseases occurring frequently in numerous agriculturally important plants, including potato, garlic and are one of the common pathogens of tomato, causing root rot in the west part of Iran. Therefore, the objectives of this study were to isolate and identify disease-causing Fusarium species from infected tomatoes based on the morphological and molecular characteristics. Twenty-five isolates of Fusarium were obtained from infected root of tomato plants collected from the fields in different regions of western Iran. Based on morphological features, the strains were classified into four following Fusarium species: F. oxysporum, F. redolens, F. proliferatum and F. verticillioides. The phylogenetic trees based on tef1 and tub2 dataset clearly distinguished closely related species. All of the isolates were evaluated for their pathogenicity on healthy tomato seedlings in the greenhouse. This is the first report on molecular identification of Fusarium species isolated from tomato plants cultivated in Iran.

  14. El consumo de basuco* como agente causal de alteraciones en la encía

    Directory of Open Access Journals (Sweden)

    Lorena Dávila

    2001-08-01

    Full Text Available El abuso en el consumo de drogas, entre ellas al BASUCO, es uno de los grandes problemas de salud pública que tiene que afrontar nuestra comunidad. En este estudio se utilizaron 40 ratas de la cepa Wistar, 20 con carácter experimental y 20 de control utilizando agua destilada durante 16 semanas. Se demostró que existe una relación directa entre el uso de BASUCO y las alteraciones clínicas e histológicas en la encía, de las cuales que el absceso gingival la patología más frecuente (63,2 % de los casos. Tomando en cuenta el incremento del consumo de drogas en nuestra sociedad y los resultados obtenidos, es importante que el odontólgo relacione el uso de las drogas como un agente causal de alteraciones en la encía.The abuse of drugs, and among them of BASUCO, is one of the great public health problems our communioty has to face. 40 Wistar strain rats were used in this study: 20 with an experimental character and 20 as controls. Distilled water was utilized during 16 weeks. It was demonstrated that there is a direct relationship between the use of BASUCO and the clinical and histological alterations of the gingiva, of which the gingival abscess is the most frequent pathology (63.2 % of the cases. Taking into account the increasing consumption of drugs in our society and the results obtained, it is important that the odontologist considers the use of drugs as a causal agent of gingival alterations.

  15. Prevalencia de Chlamydia Trachomatis como agente causal de Leucorrea único o en asociación con otros agentes en Mujeres Embarazadas

    OpenAIRE

    Benavides, María Dolores; Téllez, Aleyda; Matus, Gregorio; Baltodano Martínez, Yubelka Susana; Centeno Cárdenas, Nora María

    2008-01-01

    El objetivo del presente estudio fue, identificar la prevalencia de Chlamydia Trachomatis como agente causal único o en asociación con otros agentes causales de Leucorrea en mujeres embarazadas ingresadas en el servicio de ARO del HEODRA, en el período de Agosto de 2007 a Enero de 2008. El estudio es descriptivo, de corte transversal. Se trabajó con fuentes primarias, a través de la entrevista y exploración ginecológica de las pacientes, y secundarias, a través de la revisión de los resultado...

  16. Analysis of genetic diversity of Fusarium tupiense, the main causal agent of mango malformation disease in southern Spain

    Science.gov (United States)

    Mango malformation disease (MMD) has become an important global disease affecting this crop. The aim of this study was to identify the main causal agents of MMD in the Axarquía region of southern Spain and determine their genetic diversity. Fusarium mangiferae was previously described in the Axarquí...

  17. Complete genome sequence of Spiroplasma citri strain R8-A2T, causal agent of stubborn disease in Citrus spp

    Science.gov (United States)

    Spiroplasma citri is the causal agent of stubborn disease in Citrus spp., as well as the cause of diseases in numerous other plant genera. Here we report the nucleotide sequence of the 1,599,709 bp circular chromosome and two plasmids of strain R8-A2T. This information will facilitate comparative ...

  18. Eutypa lata, causal agent of dieback in red currant (Ribes rubrum) and gooseberry (R. uva-crispa) in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Raak, van M.; Brouwershaven, van I.R.; Martin, W.S.; Kox, L.F.F.

    2011-01-01

    Dieback of red currant (Ribes rubrum) and gooseberry (Ribes uva-crispa) is an increasing problem in commercial fields in the Netherlands. Field surveys were done in 2006–2007 and samples with dieback symptoms were analysed. In this study the causal agent was diagnosed as Eutypa lata, based on

  19. White rot of garlic and onion (Causal agent, Sclerotium cepivorum): A status report from the Pacific Northwest

    Science.gov (United States)

    There is evidence from literature, state department of agriculture documents, and recent diagnoses that Sclerotium cepivorum, causal agent of white rot of garlic and onion, is spreading and/or becoming more established in the Pacific Northwest. Previously documented distributions are summarized, an...

  20. Zika Virus: An Emergent Neuropathological Agent

    Science.gov (United States)

    White, Martyn K.; Wollebo, Hassen S.; Beckham, J. David; Tyler, Kenneth L.; Khalili, Kamel

    2016-01-01

    The emergence of Zika virus in the Americas has followed a pattern that is familiar from earlier epidemics of other viruses, where a new disease is introduced into a human population and then spreads rapidly with important public health consequences. In the case of Zika virus, an accumulating body of recent evidence implicates the virus in the etiology of serious pathologies of the human nervous system, that is, the occurrence of microcephaly in neonates and Guillain–Barré syndrome in adults. Zika virus is an arbovirus (arthropod-borne virus) and a member of the family Flaviviridae, genus Flavivirus. Zika virions are enveloped and icosahedral, and contain a nonsegmented, single-stranded, positive-sense RNA genome, which encodes 3 structural and 7 nonstructural proteins that are expressed as a single polyprotein that undergoes cleavage. Zika genomic RNA replicates in the cytoplasm of infected host cells. Zika virus was first detected in 1947 in the blood of a febrile monkey in Uganda’s Zika Forest and in crushed suspensions of the Aedes mosquito, which is one of the vectors for Zika virus. The virus remained obscure, with a few human cases confined to Africa and Asia. There are two lineages of the Zika virus, African and Asian, with the Asian strain causing outbreaks in Micronesia in 2007 and French Polynesia in 2013–2014. From here, the virus spread to Brazil with the first report of autochthonous Zika transmission in the Americas in March 2015. The rapid advance of the virus in the Americas and its likely association with microcephaly and Guillain–Barré syndrome make Zika an urgent public health concern. PMID:27464346

  1. Morphological and molecular characterization of the causal agent of downy mildew on Quinoa (Chenopodium quinoa).

    Science.gov (United States)

    Choi, Young-Joon; Danielsen, Solveig; Lübeck, Mette; Hong, Seung-Beom; Delhey, Rolf; Shin, Hyeon-Dong

    2010-05-01

    Downy mildew is an economically important and widespread disease in quinoa (Chenopodium quinoa) growing areas. Although in many studies Peronospora farinosa is most commonly regarded as the causal agent of the disease, identification and classification of the pathogen remain still uncertain due to its taxonomic confusion. Thirty-six Peronospora isolates from quinoa with different geographic origins including Argentina, Bolivia, Denmark, Ecuador, and Peru were morphologically and molecularly compared with Peronospora species from other Chenopodium species. The morphology of three herbarium specimens was similar to that of P. variabilis, which originated from C. album, characterized by flexuous to curved ultimate branchlets and pedicellated conidia. Phylogenetic analysis based on ITS rDNA sequences also placed the quinoa pathogen within the same clade as P. variabilis. Within the ITS rDNA sequences of the quinoa pathogens, two base substitutions were found, which separated the majority of the Danish isolates from isolates from South America, but no sequence difference was found among the isolates from different cultivars of quinoa. The present results indicate that the pathogen responsible for the quinoa downy mildew is identical to Peronospora variabilis and that it should not be lumped with P. farinosa as claimed previously by most studies.

  2. Current Perspectives on Mycobacterium farcinogenes and Mycobacterium senegalense, the Causal Agents of Bovine Farcy

    Directory of Open Access Journals (Sweden)

    Mohamed E. Hamid

    2014-01-01

    Full Text Available Mycobacterium farcinogenes and M. senegalense are the causal agents of bovine farcy, a chronic, progressive disease of the skin and lymphatics of zebu cattle. The disease, which is prevalent mainly in sub-Saharan Africa, was in earlier times thought to be caused by Nocardia farcinica and can be described as one of the neglected diseases in cattle. Some aspects of the disease have been investigated during the last five decades but the major development had been in the bacteriological, chemotaxonomic, and phylogenetic aspects. Molecular analyses confirmed that M. farcinogenes and M. senegalense fall in a subclade together with M. houstonense and M. fortuitum. This subclade is closely related to the one accommodating M. peregrinum, M. porcinum, M. septicum, M. neworleansense, and M. alvei. DNA probes were designed from 16S-23S rRNA internal transcribed spacer and could be used for the rapid diagnosis of bovine farcy. An ELISA assay has been evaluated for the serodiagnosis of the disease. The zoonotic potentials of M. farcinogenes and M. senegalense are unknown; few studies reported the isolation of M. senegalense and M. farcinogenes from human clinical sources but not from environmental sources or from other domestic or wild animals.

  3. FUNGITOXICITY OF ESSENTIAL OILS ON PLASMOPARA VITICOLA,CAUSAL AGENT OF GRAPEVINE DOWNY MILDEW

    Directory of Open Access Journals (Sweden)

    RÉGIS DE OLIVEIRA FIALHO

    2017-10-01

    Full Text Available ABSTRACT This study aimed to evaluate the fungitoxic (antifungal effect of seven essential oils on Plasmopara viticola, the causal agent of grapevine downy mildew. The cinnamon, eucalyptus globulus, marjoram, melaleuca, peppermint, oregano and white thyme essential oils were compared with the mancozeb + metalaxyl-M fungicide. Three experiments were conducted to evaluate the effect of essential oils on spore germination. The first experiment evaluated the effect of direct contact of essential oils on the pathogen; the second evaluated the effect of volatile compounds on the pathogen and the third assessed the behavior of essential oils, when applied to vine leaves in field conditions, on the pathogen. All essential oils inhibited the spores’ germination, but in varying degrees, in addition, presenting fungistatic activity. All the essential oils showed chemical instability when the incubation time or the interval between products application where increased, all oils decrease antifungal activity percentage. Noteworthy, the cinnamon and the eucalyptus globulus essential oils were the most fungitoxic (antifungal on P. viticola.

  4. Erwinia amylovora – the Causal Agent of Root Collar Necrosis of Apple Trees

    Directory of Open Access Journals (Sweden)

    Veljko Gavrilović

    2008-01-01

    Full Text Available A large-scale outbreak of fire blight symptoms caused by Erwinia amylovora was recorded in pome fruit trees during 2007. In addition to fruit necrosis and shoot blight as the typical disease symptoms, dark purple necrosis was observed in the root collar area girdling the trunk just above the ground and thus withering the whole apple tree. Since similar symptoms on apple trees could be caused by E. amylovora or one of several phytopathogenic fungi of the genera Phomopsis and Phytophthora, an investigation was conducted to identify the causal agent of this disease. Levan-producing, nonfluorescent bacteria were isolated from diseased samples. The isolated strains produced HR in tobacco leaves and necrosis of artificially inoculated, immature pear fruits, followed by oozing of bacterial exudate, a characterisitic of E. amylovora. Based on the results of pathogenicity tests, biochemical characteristics, ELISA test and PCR analysis, it was confirmed that the investigated strainsbelonged to E. amylovora, causing the root collar necrosis of apple trees as an atypical symptom of this bacterium in Serbia. The explanation of this symptom may be that the vegetative rootstocks were infected with E. amylovora. Therefore, the development of diagnostic protocols for detection of E. amylovora in apple rootstock is very important for health inspections of planting materials.

  5. Tetranychus urticae (Acari: Tetranychidae) transmits Acidovorax citrulli, causal agent of bacterial fruit blotch of watermelon.

    Science.gov (United States)

    Choi, Okhee; Park, Jung-Joon; Kim, Jinwoo

    2016-08-01

    The two-spotted spider mite (TSSM) Tetranychus urticae is one of the most important pests of cucurbit plants. If TSSM can act as vector for Acidovorax citrulli (Acc), causal agent of bacterial fruit blotch (BFB), then the movement of mites from infected to healthy plants may represent a potential source of inocula for BFB outbreaks. To confirm the association between Acc and TSSM, we generated a green fluorescent protein-tagged mutant strain (Acc02rf) by transposon mutagenesis and demonstrated that TSSM can transmit Acc from infected to non-infected watermelon plants. Challenge with 10 TSSMs carrying Acc02rf population densities of 1.3 × 10(3) CFU each on freshly grown individual watermelon plants caused disease transmission to 53 %. Incubation periods ranged 7-9 days. Bacteria recovered from symptoms typical of those associated with leaf necrosis were characterized and identified as Acc. To our knowledge, this is the first report showing that TSSM can be a vector of Acc. The results reported here support that the strong association of TSSM with Acc is of particular importance in controlling BFB.

  6. Characterization, In Vitro Culture, and Molecular Analysis of Thecaphora solani, the Causal Agent of Potato Smut.

    Science.gov (United States)

    Andrade, Orlando; Muñoz, Gastón; Galdames, Rafael; Durán, Paola; Honorato, Rodrigo

    2004-08-01

    ABSTRACT The fungus Thecaphora solani (syn.: Angiosorus solani), the causal agent of potato smut, was cultivated in vitro for the first time. Teliospores obtained from galls of infected potato plants were used to inoculate commonly used solid and liquid media. The teliospores produced two kinds of vegetative tissue depending on the nutrient status of the media. A very slow radial-growing, hyaline, and septate mycelium, as usually seen in most of the in vitro-cultivated filamentous fungi, was obtained in wateragar medium after 30 to 40 days. On the other hand, a white, sponge-like mycelial mass was obtained in HCM + 1% activated charcoal, and on common potato dextrose agar or malt-yeast-peptone solid or liquid media, after 40 to 50 days under lab conditions. The identity among teliospores and the sponge-like mycelial mass was corroborated by DNA fingerprinting and partial sequencing of the large subunit (LSU) rDNA region. The sexual cycle of the pathogen was completed under lab conditions based on the development of teliospores on the sponge-like mycelial mass. The first attempt to reproduce the disease under controlled conditions was successful, inducing a gall in a cv. Desirée potato explant cultivated in vitro inoculated with radial-growing mycelia. Phylogenetic analysis of LSU rDNA data of the genus Thecaphora and other smut fungi confirmed the initial classification of the pathogen as T. solani.

  7. Aleppo pine knot disease: histology of the knots, detection of causal agent and mode of transmission

    Directory of Open Access Journals (Sweden)

    ROBERTO CALAMASSI

    2008-07-01

    Full Text Available Knot disease of Aleppo pine (Pinus halepensis subsp. halepensis occurs in the western range of the host in the Mediterranean region. The disease, originally named Aleppo pine tuberculosis (from tubercle, i.e. knot by Petri in 1924, causes a hyperplastic growth on the twigs and small branches, with knots that initially are small, green and lignified, and expand to 5–6 cm diameter at maturity. These knots have been associated with various bacterial species. In this study, only one bacterium was isolated from Aleppo pine knots, and this bacterium was constantly associated with the pine weevil Pissodes castaneus. The hyperplastic growth started either in the cortex or in the xylem, while the knot was formed in the cortical parenchyma. Bacteria were grouped in zoogloeae in the intercellular spaces or inside lysigenous cavities. Bacterial microcolonies have also been observed in the parenchyma cells. Inoculation of two of the bacterial strains on healthy Aleppo pine twigs did not induce knot formation. Knots did however form when adults of P. castaneus were externally contaminated with the bacteria and were then allowed to feed on pine saplings. These latter knots contained the same bacterial isolate as that which had been used to contaminate the weevils. All the isolates examined were tentatively assigned to the genus Erwinia. As this bacterium seems to be the causal agent of Aleppo pine knot disease, its complete identification and characterisation is needed.

  8. Monitoring the infective process of the downy mildew causal agent within micropropagated rose plants

    Directory of Open Access Journals (Sweden)

    Sonia Yamile Gómez

    2012-08-01

    Full Text Available Downy mildew in the rose caused by a species of the Peronospora genus is a very restrictive disease for the Colombian greenhouse rose production. The damage observed in the susceptible varieties of commercial rose include symptoms affect young steams and tiny leaves causing reddish and brown spots and defoliation; leading to 10% production losses. The infective behavior of this pathogen was studied with the aim of increasing the knowledge about the biology of the rose downy mildew. The study of the infective process was performed on the Charlotte variety using micropropagated roses inoculated with suspensions of sporangia. A germinal tube was observed during the germination process, it came from a lateral papilla and reached up to 300 microns in length. During this study, the ability of the pathogen to use vascular sieves as communication systems within the plant was determined. Oogonia and antheridia were also observed inside the epidermal cells, and oospores inside the parenchymal tissue close to xylem vessels. To the best of our knowledge, these sexual structures have not been reported on in Colombia before. This study verifies the ability of the downy mildew causal agent to move through the xylem vessels and produce sexual structures, such as oogonia, antheridia and oospores within those tissues.

  9. Anti-Human Immunodeficiency Virus (HIV) Agents | Okolie | Journal ...

    African Journals Online (AJOL)

    This article gives a brief review of anti-retroviral agents with activity against the Human Immunodeficiency Virus (HIV) the causative agen of Acquired Immunodeficiency Syndrome (AIDS). It also outlines the principles, mode of action of anti-HIV agents and their sites of therapeutic intervention. Zidovudine or Azidothymidine ...

  10. Zika Virus and Guillain–Barre Syndrome: Is There Sufficient Evidence for Causality?

    Science.gov (United States)

    Leis, A. Arturo; Stokic, Dobrivoje S.

    2016-01-01

    Worldwide concern over Zika virus causing Guillain–Barre syndrome (GBS) soared after recent reports that Zika-related weakness was due to GBS. A global strategic response plan was initiated with recommendations for at-risk countries to prepare for GBS. This plan has major economic implications, as nations with limited resources struggle to implement costly immunotherapy. Since confirmation of causality is prerequisite to providing specific management recommendations, it is prudent to review data endorsing a GBS diagnosis. We searched PubMed for manuscripts reporting original clinical, laboratory, and electrodiagnostic data on Zika virus and GBS. Five papers met criteria; four case reports and one large case–control study (French Polynesia) that attributed 42 paralysis cases to a motor variant of GBS. Brighton criteria were reportedly used to diagnose GBS, but no differential diagnosis was presented, which violates criteria. GBS was characterized by early onset (median 6 days post-viral syndrome), rapid progression (median 6 days from onset to nadir), and atypical clinical features (52% lacked areflexia, 48% of facial palsies were unilateral). Electrodiagnostic evaluations fell short of guidelines endorsed by American Academy of Neurology. Typical anti-ganglioside antibodies in GBS motor variants were rarely present. We conclude that there is no causal relationship between Zika virus and GBS because data failed to confirm GBS and exclude other causes of paralysis. Focus should be redirected at differential diagnosis, proper use of diagnostic criteria, and electrodiagnosis that follows recommended guidelines. We also call for a moratorium on recommendations for at-risk countries to prepare costly immunotherapies directed at GBS. PMID:27746763

  11. Zika Virus and Guillain-Barre Syndrome: Is There Sufficient Evidence for Causality?

    Directory of Open Access Journals (Sweden)

    A Arturo Leis

    2016-09-01

    Full Text Available Worldwide concern over Zika virus causing Guillain-Barre syndrome (GBS soared after recent reports that Zika-related weakness was due to GBS. A global strategic response plan was initiated with recommendations for at risk countries to prepare for GBS. This plan has major economic implications, as nations with limited resources struggle to implement costly immunotherapy. Since confirmation of causality is prerequisite to providing specific management recommendations, it is prudent to review data endorsing a GBS diagnosis. We searched PubMed for manuscripts reporting original clinical, laboratory, and electrodiagnostic data on Zika virus and GBS. Five papers met criteria; four case reports and one large case-control study (French Polynesia that attributed 42 paralysis cases to a motor variant of GBS. Brighton criteria were reportedly used to diagnose GBS, but no differential diagnosis was presented, which violates criteria. GBS was characterized by early onset (median 6 days post-viral syndrome, rapid progression (median 6 days from onset to nadir, and atypical clinical features (52% lacked areflexia, 48% of facial palsies were unilateral. Electrodiagnostic evaluations fell short of guidelines endorsed by American Academy of Neurology. Typical anti-ganglioside antibodies in GBS motor variants were rarely present. We conclude that there is no causal relationship between Zika virus and GBS because data failed to confirm GBS and exclude other causes of paralysis. Focus should be redirected at differential diagnosis, proper use of diagnostic criteria, and electrodiagnosis that follows recommended guidelines. We also call for a moratorium on recommendations for at risk countries to prepare costly immunotherapies directed at GBS.

  12. Retargeting of Viruses to Generate Oncolytic Agents

    Directory of Open Access Journals (Sweden)

    M. H. Verheije

    2012-01-01

    Full Text Available Oncolytic virus therapy is based on the ability of viruses to effectively infect and kill tumor cells without destroying the normal tissues. While some viruses seem to have a natural preference for tumor cells, most viruses require the modification of their tropism to specifically enter and replicate in such cells. This review aims to describe the transductional targeting strategies currently employed to specifically redirect viruses towards surface receptors on tumor cells. Three major strategies can be distinguished; they involve (i the incorporation of new targeting specificity into a viral surface protein, (ii the incorporation of a scaffold into a viral surface protein to allow the attachment of targeting moieties, and (iii the use of bispecific adapters to mediate targeting of a virus to a specified moiety on a tumor cell. Of each strategy key features, advantages and limitations are discussed and examples are given. Because of their potential to cause sustained, multiround infection—a desirable characteristic for eradicating tumors—particular attention is given to viruses engineered to become self-targeted by the genomic expression of a bispecific adapter protein.

  13. Vaccinia virus, a promising new therapeutic agent for pancreatic cancer.

    Science.gov (United States)

    Al Yaghchi, Chadwan; Zhang, Zhongxian; Alusi, Ghassan; Lemoine, Nicholas R; Wang, Yaohe

    2015-01-01

    The poor prognosis of pancreatic cancer patients signifies a need for radically new therapeutic strategies. Tumor-targeted oncolytic viruses have emerged as attractive therapeutic candidates for cancer treatment due to their inherent ability to specifically target and lyse tumor cells as well as induce antitumor effects by multiple action mechanisms. Vaccinia virus has several inherent features that make it particularly suitable for use as an oncolytic agent. In this review, we will discuss the potential of vaccinia virus in the management of pancreatic cancer in light of our increased understanding of cellular and immunological mechanisms involved in the disease process as well as our extending knowledge in the biology of vaccinia virus.

  14. Recombinant mumps virus as a cancer therapeutic agent

    Directory of Open Access Journals (Sweden)

    Arun Ammayappan

    2016-01-01

    Full Text Available Mumps virus belongs to the family of Paramyxoviridae and has the potential to be an oncolytic agent. Mumps virus Urabe strain had been tested in the clinical setting as a treatment for human cancer four decades ago in Japan. These clinical studies demonstrated that mumps virus could be a promising cancer therapeutic agent that showed significant antitumor activity against various types of cancers. Since oncolytic virotherapy was not in the limelight until the beginning of the 21st century, the interest to pursue mumps virus for cancer treatment slowly faded away. Recent success stories of oncolytic clinical trials prompted us to resurrect the mumps virus and to explore its potential for cancer treatment. We have obtained the Urabe strain of mumps virus from Osaka University, Japan, which was used in the earlier human clinical trials. In this report we describe the development of a reverse genetics system from a major isolate of this Urabe strain mumps virus stock, and the construction and characterization of several recombinant mumps viruses with additional transgenes. We present initial data demonstrating these recombinant mumps viruses have oncolytic activity against tumor cell lines in vitro and some efficacy in preliminary pilot animal tumor models.

  15. Recombinant mumps virus as a cancer therapeutic agent.

    Science.gov (United States)

    Ammayappan, Arun; Russell, Stephen J; Federspiel, Mark J

    2016-01-01

    Mumps virus belongs to the family of Paramyxoviridae and has the potential to be an oncolytic agent. Mumps virus Urabe strain had been tested in the clinical setting as a treatment for human cancer four decades ago in Japan. These clinical studies demonstrated that mumps virus could be a promising cancer therapeutic agent that showed significant antitumor activity against various types of cancers. Since oncolytic virotherapy was not in the limelight until the beginning of the 21(st) century, the interest to pursue mumps virus for cancer treatment slowly faded away. Recent success stories of oncolytic clinical trials prompted us to resurrect the mumps virus and to explore its potential for cancer treatment. We have obtained the Urabe strain of mumps virus from Osaka University, Japan, which was used in the earlier human clinical trials. In this report we describe the development of a reverse genetics system from a major isolate of this Urabe strain mumps virus stock, and the construction and characterization of several recombinant mumps viruses with additional transgenes. We present initial data demonstrating these recombinant mumps viruses have oncolytic activity against tumor cell lines in vitro and some efficacy in preliminary pilot animal tumor models.

  16. Potential of Pest and Host Phenological Data in the Attribution of Regional Forest Disturbance Detection Maps According to Causal Agent

    Science.gov (United States)

    Spruce, Joseph; Hargrove, William; Norman Steve; Christie, William

    2014-01-01

    Near real time forest disturbance detection maps from MODIS NDVI phenology data have been produced since 2010 for the conterminous U.S., as part of the on-line ForWarn national forest threat early warning system. The latter has been used by the forest health community to identify and track many regional forest disturbances caused by multiple biotic and abiotic damage agents. Attribution of causal agents for detected disturbances has been a goal since project initiation in 2006. Combined with detailed cover type maps, geospatial pest phenology data offer a potential means for narrowing the candidate causal agents responsible for a given biotic disturbance. U.S. Aerial Detection Surveys (ADS) employ such phenology data. Historic ADS products provide general locational data on recent insect-induced forest type specific disturbances that may help in determining candidate causal agents for MODIS-based disturbance maps, especially when combined with other historic geospatial disturbance data (e.g., wildfire burn scars and drought maps). Historic ADS disturbance detection polygons can show severe and extensive regional forest disturbances, though they also can show polygons with sparsely scattered or infrequent disturbances. Examples will be discussed that use various historic disturbance data to help determine potential causes of MODIS-detected regional forest disturbance anomalies.

  17. Evidence for Systemic Infection by Puccinia horiana, Causal Agent of Chrysanthemum White Rust, in Chrysanthemum.

    Science.gov (United States)

    Bonde, M R; Murphy, C A; Bauchan, G R; Luster, D G; Palmer, C L; Nester, S E; Revell, J M; Berner, D K

    2015-01-01

    Puccinia horiana, causal agent of the disease commonly known as chrysanthemum white rust (CWR), is a quarantine-significant fungal pathogen of chrysanthemum in the United States and indigenous to Asia. The pathogen was believed to have been eradicated in the United States but recently reappeared on several occasions in northeastern United States. The objective of the study presented here was to determine whether P. horiana could systemically infect chrysanthemum plants, thus providing a means of survival through winters. Scanning and transmission electron microscopy revealed the development of P. horiana on the surface and within leaves, stems, or crowns of inoculated chrysanthemum plants artificially exposed to northeastern U.S. winter temperatures. P. horiana penetrated leaves directly through the cuticle and then colonized the mesophyll tissue both inter- and intracellularly. An electron-dense material formed at the interface between fungal and host mesophyll cells, suggesting that the pathogen adhered to the plant cells. P. horiana appeared to penetrate mesophyll cell walls by enzymatic digestion, as indicated by the absence of deformation lines in host cell walls at penetration sites. The fungus was common in vascular tissue within the infected crown, often nearly replacing the entire contents of tracheid cell walls. P. horiana frequently passed from one tracheid cell to an adjacent tracheid cell by penetration either through pit pairs or nonpitted areas of the cell walls. Individual, presumed, fungal cells in mature tracheid cells of the crown and stems arising from infected crowns suggested that the pathogen might have been moving at least partially by means of the transpiration stream. The demonstration that chrysanthemum plants can be systemically infected by P. horiana suggests that additional disease control measures are required to effectively control CWR.

  18. In vitro Antifungal Activity of Different Plant Extracts against Phytophthora infestans the Causal Agent of Potato Late Blight

    OpenAIRE

    Saida Messgo-Moumene; Rym Boukhalfa; Djazia Belaïdi; Lyes Beninal; Siham Haddadj-Hamdi; Mohamed Bellatreche

    2017-01-01

    Our study aimed to evaluate the in vitro antifungal activity of aqueous extracts prepared from seven medicinal plants (Carya illinoinensis, Equisetum arvense, Rosmarinus officinalis, Pistacia lentiscus, Mentha suaveolens, Punica granatum, and Posidonia oceanica) against A1 and A2 isolates of Phytophthora infestans the causal agent of potato late blight. The crude (100%) plant extracts were prepared by decoction and tested at various concentrations (70, 50, 30 and 10% v/v) for dete...

  19. Epstein-Barr virus and Burkitt's lymphoma worldwide: the causal relationship revisited.

    Science.gov (United States)

    de-Thé, G

    1985-01-01

    Burkitt's lymphoma (BL) in tropical Africa represents by far the most common tumour in children between 0 and 14 years of age, 97% of the tumours being associated with Epstein-Barr virus (EBV). In North Africa, the tumour is about ten times less frequent than in equatorial Africa, but, according to reports from Algeria, 85% of the cases appear to be associated with EBV. In Western countries, BL represents about 3% of childhood tumours, 10 to 15% of them EBV-associated. Thus, from the northern industrialized countries to the equatorial developing countries, increasing incidences of lymphomas of the BL type are paralleled by an increasing proportion of EBV-associated cases. The Ugandan BL prospective study showed that high antibody titres to viral capsid antigen (VCA) preceded BL development by many years, with a quantifiable relationship between the level of VCA antibodies and tumour risk. If an early and/or massive EBV primary infection seems to represent the critical event for BL development in equatorial Africa, the favourable conditions for EBV-associated tumours in North Africa and in Europe remain to be investigated. Malaria appears to favour BL development through an EBV-specific T-cell immune deficiency. Chromosomal translocations and oncogene activation, considered as the final step in lymphoma development, do not appear to be related to EBV. Intervention against the virus may represent the ultimate proof of a causal relationship between EBV and the majority of BL cases around the world.

  20. Clarification on host range of Didymella pinodes the causal agent of pea ascochyta blight

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    Eleonora eBarilli

    2016-05-01

    Full Text Available Didymella pinodes is the principal causal agent of ascochyta blight, one of the most important fungal diseases of pea (Pisum sativum worldwide. Understanding its host specificity has crucial implications in epidemiology and management; however, this has not been clearly delineated yet. In this study we attempt to clarify the host range of D. pinodes and to compare it with that of other close Didymella spp. D. pinodes was very virulent on pea accessions, although differences in virulence were identified among isolates. On the contrary, studied isolates D. fabae, D. rabiei and D. lentil showed a reduced ability to infect pea not causing macroscopically visible symptoms on any of the pea accessions tested.D. pinodes isolates were also infective to some extend on almost all species tested including species such as Hedysarum coronarium, Lathyrus sativus, Lupinus albus, Medicago spp., Trifolium spp., Trigonella foenum-graecum and Vicia articulata which were not mentioned before as hosts of D. pinodes. On the contrary, D. lentil and D. rabiei were more specific, infecting only lentil and chickpea, respectively. D. fabae was intermediate, infecting mainly faba bean, but also slightly other species such as Glycine max, Phaseolus vulgaris, Trifolium spp., Vicia sativa and V. articulata.DNA sequence analysis of the nuclear ribosomal internal transcribed spacer region (ITS was performed to confirm identity of the isolates studies and to determine phylogenetic relationship among the Didymella species, revealing the presence of two clearly distinct clades. Clade one was represented by two supported subclusters including D. fabae isolates as well as D. rabiei with D. lentil isolates. Clade two was the largest and included all the D. pinodes isolates as well as Phoma medicaginis var. pinodella. Genetic distance between D. pinodes and the other Didymella spp. isolates was not correlated with overall differences in pathogenicity. Based on evidences presented here

  1. Cholesterol reducing agents inhibit assembly of type I parainfluenza viruses.

    Science.gov (United States)

    Bajimaya, Shringkhala; Hayashi, Tsuyoshi; Frankl, Tünde; Bryk, Peter; Ward, Brian; Takimoto, Toru

    2017-01-15

    Many enveloped RNA viruses utilize lipid rafts for the assembly of progeny virions, but the role of cholesterol, a major component of rafts, on paramyxovirus budding and virion formation is controversial. In this study, we analyzed the effects of FDA-approved cholesterol-reducing agents, gemfibrozil and lovastatin, on raft formation and assembly of human parainfluenza virus type 1 (hPIV1) and Sendai virus (SeV). Treatment of the human airway epithelial A549 cells with the agents, especially when combined, significantly decreased production of infectious hPIV1 and SeV. Mechanistic analysis indicated that depletion of cellular cholesterol reduced cell surface accumulation of envelope glycoproteins and association of viral matrix and nucleocapsids with raft membrane, which resulted in impaired virus budding and release from the cells. These results indicate that cellular cholesterol is required for assembly and formation of type 1 parainfluenza viruses and suggest that cholesterol could be an attractive target for antiviral agents against hPIV1. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Molecular characterization and pathogenicity assays of Colletotrichum acutatum, causal agent for lime anthracnose in Texas

    Science.gov (United States)

    Several distorted Mexican lime [Citrus aurantiifolia (Christm). Swingle] fruit, leaf, and twig samples with lime anthracnose symptoms were collected from three trees in residential areas of Brownsville, Texas. The causal fungal organism, Colletotrichum acutatum J. H. Simmonds was isolated from leave...

  3. Host range of Phakopsora pachyrhizi, the causal agent of soybean rust

    Science.gov (United States)

    Phakopsora pachyrhizi, the causal organism of soybean rust, was first described in 1903 from leaves of Glycine max subsp. soja, or wild soybean, in Japan. Since that time, there have been numerous reports of the pathogen on various leguminous species around the world, first in Asia, followed by Aust...

  4. [Canine distemper virus--an agent looking for new hosts].

    Science.gov (United States)

    Baumgärtner, W; Alldinger, S; Beineke, A; Gröters, S; Herden, C; Kaim, U; Müller, G; Seeliger, F; Van Moll, P; Wohlsein, P

    2003-04-01

    Canine distemper is caused by the canine distemper virus (CDV), a RNA virus belonging to the genus Morbillivirus of the family Paramyxoviridae. The genus Morbillivirus includes measles virus, Rinderpest virus and peste-des-petits-ruminants virus. The host spectrum of CDV, which includes numerous families of Carnivores, has been changed in the last years and distemper-like diseases have been observed in numerous other species. These include epidemics in large felids, marine mammals and javelinas. Different viruses have been isolated from pinnipeds including a seal-specific isolate, termed phocine distemper virus 1, PDV-1, and a CDV strain, named PDV-2. Retrospective analysis of previous epidemics among marine mammals in various regions of the world provide evidence for the occurrence of so far unrecognized morbillivirus epidemics. In some including the mass mortalities of Baikal and Caspian seals and of large felids in the Serengeti, terrestrial carnivores including dogs and wolves have been suspected as a vector for the infectious agent. However, in other epidemics among marine mammals the source of infection remains unknown including both seal epidemics in northwestern Europe in 1988 and 2002. It remains to be determined whether a morbillivirus from other marine mammals or terrestrial carnivores caused the infection in this unprotected seal populations.

  5. Antiviral agents for herpes simplex virus.

    Science.gov (United States)

    Vere Hodge, R Anthony; Field, Hugh J

    2013-01-01

    This review starts with a brief description of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), the clinical diseases they cause, and the continuing clinical need for antiviral chemotherapy. A historical overview describes the progress from the early, rather toxic antivirals to acyclovir (ACV) which led the way for its prodrug, valacyclovir, to penciclovir and its prodrug, famciclovir (FCV). These compounds have been the mainstay of HSV therapy for two decades and have established a remarkable safety record. This review focuses on these compounds, the preclinical studies which reveal potentially important differences, the clinical trials, and the clinical experience through two decades. Some possible areas for further investigation are suggested. The focus shifts to new approaches and novel compounds, in particular, the combination of ACV with hydrocortisone, known as ME609 or zovirax duo, an HSV helicase-primase inhibitor, pritelivir (AIC316), and CMX001, the cidofovir prodrug for treating resistant HSV infection in immunocompromised patients. Letermovir has established that the human cytomegalovirus terminase enzyme is a valid target and that similar compounds could be sought for HSV. We discuss the difficulties facing the progression of new compounds. In our concluding remarks, we summarize the present situation including a discussion on the reclassification of FCV from prescription-only to pharmacist-controlled for herpes labialis in New Zealand in 2010; should this be repeated more widely? We conclude that HSV research is emerging from a quiescent phase. © 2013 Elsevier Inc. All rights reserved.

  6. Development of novel microsatellites from Moniliophthora perniciosa, causal agent of the witches' broom disease of Theobroma cacao.

    Science.gov (United States)

    Silva, Jurema R Q; Figueira, Antonio; Pereira, Gonçalo A G; Albuquerque, Paulo

    2008-07-01

    Moniliophthora perniciosa is the causal agent of the witches' broom disease of cacao. Based on available genomic sequences, we identified 30 new microsatellite loci, which were analysed using 50 isolates from four populations sampled over a wide geographical area in Brazil, including three populations from the Amazon, the fungal putative centre of diversity, plus one from Bahia. Nine loci were polymorphic, with an average of 2.9 alleles per locus. The level of polymorphism observed was low, but these markers may allow the evaluation of pathogen diversity and the establishment of molecular standards for isolate fingerprinting to support cacao breeding. © 2007 The Authors. Journal compilation © 2007 Blackwell Publishing Ltd.

  7. ANTAGONISTIC EFFECT OF FOUR FUNGAL ISOLATES TO GANODERMA BONINENSE, THE CAUSAL AGENT OF BASAL STEM ROT OF OIL PALM

    Directory of Open Access Journals (Sweden)

    OKKY SETYAWATI DHARMAPUTRA

    1990-01-01

    Full Text Available Four fungal isolates from soils obtained from three sites of the oil palm plantations in North Sumatra were found antagonistic to Ganoderma boninense, the causal agent of basal stem rot of oil palm. Penicillium citrinum inhibited the growth of the pathogen and formed a zone of inhibition on the agar media. Trichoderma harzianum BIO - 1 as well as BIO - 2 and T. viride not only repressed the growth of the pathogen but also caused lysis of the hyphae, and the colony was totally overgrown by the antagonists.

  8. The Born Rule and Free Will: why Libertarian Agent-Causal Free Will is not "antiscientific"

    Science.gov (United States)

    Kastner, Ruth E.

    In the libertarian "agent causation" view of free will, free choices are attributable only to the choosing agent, as opposed to a specific cause or causes outside the agent. An often-repeated claim in the philosophical literature on free will is that agent causation necessarily implies lawlessness, and is therefore "antiscientific." That claim is critiqued and it is argued, on the contrary, that the volitional powers of a free agent need not be viewed as anomic, specifically with regard to the quantum statistical law (the Born Rule). Assumptions about the role and nature of causation, taken as bearing on volitional agency, are examined and found inadequate to the task. Finally, it is suggested that quantum theory may constitute precisely the sort of theory required for a nomic grounding of libertarian free will.

  9. Species-specific detection and identification of fusarium species complex, the causal agent of sugarcane pokkah boeng in China.

    Directory of Open Access Journals (Sweden)

    Zhenyue Lin

    Full Text Available BACKGROUND: Pokkah boeng disease caused by the Fusarium species complex results in significant yield losses in sugarcane. Thus, the rapid and accurate detection and identification of the pathogen is urgently required to manage and prevent the spreading of sugarcane pokkah boeng. METHODS: A total of 101 isolates were recovered from the pokkah boeng samples collected from five major sugarcane production areas in China throughout 2012 and 2013. The causal pathogen was identified by morphological observation, pathogenicity test, and phylogenetic analysis based on the fungus-conserved rDNA-ITS. Species-specific TaqMan real-time PCR and conventional PCR methods were developed for rapid and accurate detection of the causal agent of sugarcane pokkah boeng. The specificity and sensitivity of PCR assay were also evaluated on a total of 84 isolates of Fusarium from China and several isolates from other fungal pathogens of Sporisorium scitamineum and Phoma sp. and sugarcane endophyte of Acremonium sp. RESULT: Two Fusarium species (F. verticillioides and F. proliferatum that caused sugarcane pokahh boeng were identified by morphological observation, pathogenicity test, and phylogenetic analysis. Species-specific TaqMan PCR and conventional PCR were designed and optimized to target their rDNA-ITS regions. The sensitivity of the TaqMan PCR was approximately 10 pg of fungal DNA input, which was 1,000-fold over conventional PCR, and successfully detected pokkah boeng in the field-grown sugarcane. CONCLUSIONS/SIGNIFICANCE: This study was the first to identify two species, F. verticillioides and F. proliferatum, that were causal pathogens of sugarcane pokkah boeng in China. It also described the development of a species-specific PCR assay to detect and confirm these pathogens in sugarcane plants from mainland China. This method will be very useful for a broad range of research endeavors as well as the regulatory response and management of sugarcane pokkah boeng.

  10. Hepatitis C Virus Resistance to Carbohydrate-Binding Agents.

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    Laure Izquierdo

    Full Text Available Carbohydrate binding agents (CBAs, including natural lectins, are more and more considered as broad-spectrum antivirals. These molecules are able to directly inhibit many viruses such as Human Immunodeficiency Virus (HIV, Hepatitis C Virus (HCV, Dengue Virus, Ebola Virus or Severe Acute Respiratory Syndrome Coronavirus through binding to envelope protein N-glycans. In the case of HIV, it has been shown that CBAs select for mutant viruses with N-glycosylation site deletions which are more sensitive to neutralizing antibodies. In this study we aimed at evaluating the HCV resistance to CBAs in vitro. HCV was cultivated in the presence of increasing Galanthus nivalis agglutinin (GNA, Cyanovirin-N, Concanavalin-A or Griffithsin concentrations, during more than eight weeks. At the end of lectin exposure, the genome of the isolated strains was sequenced and several potential resistance mutations in the E1E2 envelope glycoproteins were identified. The effect of these mutations on viral fitness as well as on sensitivity to inhibition by lectins, soluble CD81 or the 3/11 neutralizing antibody was assessed. Surprisingly, none of these mutations, alone or in combination, conferred resistance to CBAs. In contrast, we observed that some mutants were more sensitive to 3/11 or CD81-LEL inhibition. Additionally, several mutations were identified in the Core and the non-structural proteins. Thus, our results suggest that in contrast to HIV, HCV resistance to CBAs is not directly conferred by mutations in the envelope protein genes but could occur through an indirect mechanism involving mutations in other viral proteins. Further investigations are needed to completely elucidate the underlying mechanisms.

  11. Characterization of Mycobacterium salmoniphilum as causal agent of mycobacteriosis in Atlantic salmon, Salmo salar L., from a freshwater recirculation system.

    Science.gov (United States)

    Aro, L; Correa, K; Martínez, A; Ildefonso, R; Yáñez, J M

    2014-04-01

    Thirty Atlantic salmon, Salmo salar L., with low corporal condition relative to other fish present in the culture system, were sampled from a freshwater recirculation pisciculture located in Chile. The most characteristic signs and lesions were cachexia and presence of multiple greyish-white granulomas within internal organs. The external and internal lesions, along with the microscopic, histologic and biochemical findings, were consistent with mycobacteriosis. The identification of Mycobacterium salmoniphilum as the causal agent of the lesions was possible through the use of molecular analyses. This study represents the first report of Mycobacterium salmoniphilum in a freshwater recirculation system and the first case of fish mycobacteriosis described in Chile. © 2013 John Wiley & Sons Ltd.

  12. The potato dry rot causal agent and severity in Ardabil storages and the resistance of cultivars to the disease

    Directory of Open Access Journals (Sweden)

    Leila Khoshnevis

    2016-09-01

    Full Text Available Introduction: Dry rot is one of the most important diseases of potato in storages. The aim of this study was to determine dry rot severity in potato storages of Ardabil, identify the disease causal agents and evaluate some potato cultivars resistance to the disease. Materials and methods: Totally 150 infected samples were collected from thirty nine studied storages in Ardabil. Dry rot severity and the prevalence of infected tubers were determined by surveying three 50 kg bags of potato in the storages. Fungi isolated and purified from the tubers with dry rot symptoms. A factorial design with four replications was applied in order to evaluate the reaction of five potato cultivars to four Fusarium species and determining the resistant one to dry rot. Potato tuber slices were inoculated by conidial suspension of Fusarium species. Four days after inoculation and maintaining in darkness and 25oC, the cultivars susceptibility was  identified. Results: Four species of Fusarium were identified as dry rot causal agents in Ardabil as follows: F. oxysporum, F. poae, F. solani and F. sporotrichioides. There was no significant difference between Fusarium species in pathogenicity. The reaction of cultivars to various Fusarium species was different. Boren had the lowest infection (12.5% and Sabalan showed the highest (98.87 %. Sabalan ،Khavaran ،Agria and hybrid line 3970093 displayed the highest susceptibility to various studied Fusarium species. Discussion and conclusion: Based on the results, Boren is introduced as the most resistant cultivar to Fusarium dry rot and Sabalan, Agria and hybrid line 3970093 as the susceptible ones.

  13. Amebae and ciliated protozoa as causal agents of waterborne zoonotic disease.

    Science.gov (United States)

    Schuster, Frederick L; Visvesvara, Govinda S

    2004-12-09

    The roles free-living amebae and the parasitic protozoa Entamoeba histolytica and Balantidium coli play as agents of waterborne zoonotic diseases are examined. The free-living soil and water amebae Naegleria fowleri, Acanthamoeba spp., and Balamuthia mandrillaris are recognized etiologic agents of mostly fatal amebic encephalitides in humans and other animals, with immunocompromised and immunocompetent hosts among the victims. Acanthamoeba spp. are also agents of amebic keratitis. Infection is through the respiratory tract, breaks in the skin, or by uptake of water into the nostrils, with spread to the central nervous system. E. histolytica and B. coli are parasitic protozoa that cause amebic dysentery and balantidiasis, respectively. Both intestinal infections are spread via a fecal-oral route, with cysts as the infective stage. Although the amebic encephalitides can be acquired by contact with water, they are not, strictly speaking, waterborne diseases and are not transmitted to humans from animals. Non-human primates and swine are reservoirs for E. histolytica and B. coli, and the diseases they cause are acquired from cysts, usually in sewage-contaminated water. Amebic dysentery and balantidiasis are examples of zoonotic waterborne infections, though human-to-human transmission can occur. The epidemiology of the diseases is examined, as are diagnostic procedures, anti-microbial interventions, and the influence of globalization, climate change, and technological advances on their spread.

  14. Monoclonal Antibodies as Prophylactic and Therapeutic Agents Against Chikungunya Virus.

    Science.gov (United States)

    Clayton, April M

    2016-12-15

    Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that is responsible for considerable epidemics worldwide and recently emerged in the Americas in 2013. CHIKV may cause long-lasting arthralgia after acute infection. With currently no licensed vaccines or antivirals, the design of effective therapies to prevent or treat CHIKV infection is of utmost importance and will be facilitated by increased understanding of the dynamics of chikungunya. In this article, monoclonal antibodies against CHIKV as viable prophylactic and therapeutic agents will be discussed. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  15. Non- dermatophytes as emerging opportunistic causal agents of superficial mycoses at Balaghat (M.P

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    S M Singh

    1990-01-01

    Full Text Available A clinico-mycological study of 75 suspected cases of superficial mycoses occurring at Balaghat (MP was done. Out of these 51 cases were both KOH as well as culture positive. Among these 51 cases, 33 were of onychomycosis and in the rest of the cases either skin and/ or both nails were infected. Among the isolates recovered, 27 were of dermatophytes, 22 non- dermatophytes and 4 yeasts. Trichophyton rubrum was the only species recovered among dermatophytes. The most prevalent among non dermatophytes were Hendersonula toruloidea. Microascus cinereus, Fusarium solani. Trichosporon sp. Canadida Curvularia lunate, Chaetophoma dermo-unquis, Geosmithia putterilli. Eupenicillum pervum, Phialophora bubakii and Phoma multirostrata. The use of cycloheximide free medium is recommended in the isolation of non-dermatophyte aetiologic agent causing superficial mycoses.

  16. Sharka: how do plants respond to Plum pox virus infection?

    National Research Council Canada - National Science Library

    Clemente-Moreno, María J; Hernández, José A; Diaz-Vivancos, Pedro

    2015-01-01

    Plum pox virus (PPV), the causal agent of sharka disease, is one of the most studied plant viruses, and major advances in detection techniques, genome characterization and organization, gene expression, transmission...

  17. Variable Number of Tandem Repeat Markers in the Genome Sequence of Mycosphaerella Fijiensis, the Causal Agent of Black Leaf Streak Disease of Banana (Musa spp.)

    Science.gov (United States)

    Mycosphaerella fijiensis, the causal agent of banana leaf streak disease (commonly known as black Sigatoka), is the most devastating pathogen attacking bananas (Musa spp). Recently the whole genome sequence of M. fijiensis became available. This sequence was screened for the presence of Variable Num...

  18. Thermal inactivation of infested plants, nursery equipment, and soil is a management option for the treatment of Phytophthora ramorum, causal agent of sudden oak death

    Science.gov (United States)

    Wolfgang Schweigkofler; Vernon Huffman; Karen Suslow; Kathleen Kosta

    2017-01-01

    Infected nursery plants play an important role in the spread of Phytophthora ramorum , the causal agent of sudden oak death and ramorum blight. In order to minimize the risk for disease transmission to new areas, nurseries are inspected regularly for P. ramorum , and federal regulations require the eradication of...

  19. Presencia de Blastocystis Hominis como agente causal de enfermedades gatrointestinales en la comuna 7 (Gaira del Distrito de Santa Marta

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    Sonja Liliana Lozano Socarras

    2013-10-01

    Full Text Available La Blastocystis hominis es un protozoo que causa cuadros diarreicos. Es altamente prevalente en poblaciones que no cuentan con servicios adecuados de higiene, alcantarillado y salud pública. La infección con Blastocystis hominis frecuentemente concomita con otros enteropatógenos de reconocida patogenicidad, además se ha reportado como parásito oportunista en pacientes con VIII SIDA. El objetivo del presente estudio es determinar la presencia de Blastocystis hominis en pacientes de consulta externa con síntomas asociados a enfermedades gastrointestinales, en la comuna 7 del distrito de Santa Marta, Colombia, durante el mes de Enero a Diciembre de 2004. El método de diagnóstico utilizado fue examen coproparasitológico seriado y el número de pacientes analiza-dos fue de 291. Los resultados muestran una alta presencia de Blastocystis hominken pacientes con enfermedad diarreica residentes en Gaira. Un alto porcentaje de la población parasitada (62,6% presento como único agente causal de la enfermedad diarreica al Blastocystis hominis lo que sugiere la presencia de otras enfermedades que pueden involucrar un compromiso inmunológico, el efecto será una respuesta inmune débil contra el parásito.

  20. Production of calcium oxalate crystals by the basidiomycete Moniliophthora perniciosa, the causal agent of witches' broom disease of Cacao.

    Science.gov (United States)

    Rio, Maria Carolina S do; de Oliveira, Bruno V; de Tomazella, Daniela P T; Silva, José A Fracassi da; Pereira, Gonçalo A G

    2008-04-01

    Oxalic acid has been shown as a virulence factor for some phytopathogenic fungi, removing calcium from pectin and favoring plant cell wall degradation. Recently, it was published that calcium oxalate accumulates in infected cacao tissues during the progression of Witches' Broom disease (WBD). In the present work we report that the hemibiotrophic basidiomycete Moniliophthora perniciosa, the causal agent of WBD, produces calcium oxalate crystals. These crystals were initially observed by polarized light microscopy of hyphae growing on a glass slide, apparently being secreted from the cells. The analysis was refined by Scanning electron microscopy and the compositon of the crystals was confirmed by energy-dispersive x-ray spectrometry. The production of oxalate by M. perniciosa was reinforced by the identification of a putative gene coding for oxaloacetate acetylhydrolase, which catalyzes the hydrolysis of oxaloacetate to oxalate and acetate. This gene was shown to be expressed in the biotrophic-like mycelia, which in planta occupy the intercellular middle-lamella space, a region filled with pectin. Taken together, our results suggest that oxalate production by M. perniciosa may play a role in the WBD pathogenesis mechanism.

  1. Dieback of rose caused by Acremonium sclerotigenum as a new causal agent of rose dieback in Iran

    Energy Technology Data Exchange (ETDEWEB)

    Mirtalebi, M.; Banihashemi, Z.; Sabahi, F.; Mafakheri, H.

    2016-07-01

    Severe dieback of rose has been recently observed in several rose greenhouses in Fars province of Iran. During 2014 and 2015, stems of rose plants showing yellow to brown discoloration and dieback were collected from rose greenhouses. Coniothyrium fuckelii, Botrytis cinerea and Acremonium were subsequently isolated from the margin between healthy and symptomatic tissue. B. cinerea and C. fuckelii isolates were similar to those previously reported for dieback of rose worldwide. Morphological and cultural characters along with molecular analysis based on partial sequences of the internal transcribed spacer (ITS) region of the ribosomal RNA genome allowed confirming the affiliation of the Acremonium isolates, corresponding to A. sclerotigenum as a new causal agent of rose dieback. To determine its pathogenicity on rose, Koch's postulates were fulfilled by stem inoculation of nine rose cultivars under greenhouse conditions. While A. sclerotigenum is considered as a soil-born pathogen, and produces sclerotia that are resistant to adverse conditions enables the fungus to survive extended period in soil, propagule trapping in our study revealed that conidia can become airborn, imply that an aerial phase, forms an important component of the disease cycle.

  2. Relationships between altitude, triatomine (Triatoma dimidiata) immune response and virulence of Trypanosoma cruzi, the causal agent of Chagas' disease.

    Science.gov (United States)

    DE Fuentes-Vicente, J A; Cabrera-Bravo, M; Enríquez-Vara, J N; Bucio-Torres, M I; Gutiérrez-Cabrera, A E; Vidal-López, D G; Martínez-Ibarra, J A; Salazar-Schettino, P M; Córdoba-Aguilar, A

    2017-03-01

    Little is known about how the virulence of a human pathogen varies in the environment it shares with its vector. This study focused on whether the virulence of Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae), the causal agent of Chagas' disease, is related to altitude. Accordingly, Triatoma dimidiata (Hemiptera: Reduviidae) specimens were collected at three different altitudes (300, 700 and 1400 m a.s.l.) in Chiapas, Mexico. The parasite was then isolated to infect uninfected T. dimidiata from the same altitudes, as well as female CD-1 mice. The response variables were phenoloxidase (PO) activity, a key insect immune response, parasitaemia in mice, and amastigote numbers in the heart, oesophagus, gastrocnemius and brain of the rodents. The highest levels of PO activity, parasitaemia and amastigotes were found for Tryp. cruzi isolates sourced from 700 m a.s.l., particularly in the mouse brain. A polymerase chain reaction-based analysis indicated that all Tryp. cruzi isolates belonged to a Tryp. cruzi I lineage. Thus, Tryp. cruzi from 700 m a.s.l. may be more dangerous than sources at other altitudes. At this altitude, T. dimidiata is more common, apparently because the conditions are more beneficial to its development. Control strategies should focus activity at altitudes around 700 m a.s.l., at least in relation to the region of the present study sites. © 2016 The Royal Entomological Society.

  3. Characterization of Phytophthora pistaciae, the causal agent of pistachio gummosis, based on host range, morphology, and ribosomal genome

    Directory of Open Access Journals (Sweden)

    Zahra MIRSOLEIMANI

    2014-01-01

    Full Text Available Gummosis is the most important disease of pistachio trees in Iranian pistachio orchards. Phytophthora pistaciae, the main causal agent of this disease, was isolated and described from Kerman province of Iran for the first time. The present study aimed to establish the host range, morphological characteristics and ribosomal genome of P. pistaciae isolates. During 2009–2010, isolates of P. pistaciae were sampled from 12 infected pistachio plantations in Kerman and Yazd provinces of Iran. Based on phylogenetic analysis of ITS regions, all isolates belonged to a monophyletic clade and clustered with P. pistaciae from other studies. The isolates were high temperature tolerant and produced non-papillate, ellipsoid to ovoid sporangia with polar caps, and were non-caducous, sympodial and had internal and external proliferation. The isolates were homothallic and produced spherical oogonia with smooth walls and paragynous, rarely amphigynous, spherical to ovoid antheridia. Oospores were spherical, colorless and aplerotic. Isolates generated chlamydospores in host tissues. The host range of P. pistaciae is not limited to pistachio species. Almond, walnut, apricot, grape, mango, sour cherry, among woody plants, and pea, different types of beans, chickpea, faba bean, safflower and okra, among herbaceous plants, were shown to be potential hosts of the pathogen. This study showed that isolates of P. pistaciae were homogenous in ITS rDNA genome and their host range, and morphological traits were similar. 

  4. Efficacy of Copper Compounds in Controlling Xanthomonas campestris pv. vesicatoria, the Causal Agent of Bacterial Spot of Pepper

    Directory of Open Access Journals (Sweden)

    Svetlana Milijašević

    2006-01-01

    Full Text Available The efficacy of several new formulations of copper compounds in controlling Xanthomonas campestris pv. vesicatoria in pepper was estimated in field conditions using artificial inoculation. The efficacies of Cuprozin 35 WP (copper-oxychloride and Blauvit(copper-hydroxide were tested in the localities Dobanovci and Kupinovo in 2005. Another two formulations, Cuproxat (copper-sulfate and Fungohem SC (copper-hydroxide, were tested along with the previous two in the localities Zemun and Smederevska Palanka in2006. Both bactericides tested in 2005 exhibited high efficacy in controlling X. c. pv. vesicatoria in both localities. However, there were no significant differences in the efficacy of Cuprozin 35 WP at higher concentration (74.3%-78.7% and Blauvit (74.6%-78.9% inthe two trials. Cuprozin 35 WP decreased efficacy, but a satisfactory effectiveness was still achieved at lower concentration (66.5%-66.5%. In the experiments conducted in 2006, higher concentration of Fungohem SC showed the highest efficacy (86.1%-89.1% in controllingbacterial spot of pepper. Blauvit, Cuprozin 35 WP and Cuproxat also exhibited high efficacy. However, there were no significant differences in the efficacy of these bactericides between the two localities. Fungohem SC applied at lower concentration was less effective (77.2%-80.0% but its efficacy was still good enough. Our experiments showed that copper bactericides based on copper-sulfate, copper-oxychloride and copper-hydroxide exhibited satisfactory efficacy in controlling the causal agent of bacterial spot of pepper in our climatic conditions.

  5. Development of Nested-PCR Assay to Detect Acidovorax citrulli, a Causal Agent of Bacterial Fruit Blotch at Cucurbitaceae

    Directory of Open Access Journals (Sweden)

    Young-Tak Kim

    2015-06-01

    Full Text Available The specific and sensitive nested-PCR method to detect Acidovorax citrulli, a causal agent of bacterial fruit blotch on cucurbitaceae, was developed. PCR primers were designed from the draft genome sequence which was obtained with the Next Generation Sequencing of A. citrulli KACC10651, and the nested-PCR primer set (Ac-ORF 21F/Ac-ORF 21R were selected by checking of specificity to A. citrulli with PCR assays. The selected nested-PCR primer amplified the 140 bp DNA only from A. citrulli strains, and detection sensitivity of the nested PCR increased 10,000 times of 1st PCR detection limit (10 ng genomic DNA/PCR. The nested PCR detected A. citrulli from the all samples of seed surface wash (external seed detection of the artificially inoculated watermelon seeds with 101 cfu/ml and above population of A. citrulli while the nested PCR could not detected A. citrulli from the mashed seed suspension (internal seed detection of the all artificially inoculated watermelon seeds. When the naturally infested watermelon seeds (10% seed infested rate with grow-out test used, the nested PCR detected A. citrulli from 2 seed samples out of 10 replication samples externally and 5 seed samples out of 10 replication samples internally. We believe that the nested-PCR developed in this study will be useful method to detect A. citrulli from the Cucurbitaceae seeds.

  6. Causal direction between respiratory syncytial virus bronchiolitis and asthma studied in monozygotic twins

    DEFF Research Database (Denmark)

    Poorisrisak, Porntiva; Halkjaer, Liselotte Brydensholt; Thomsen, Simon Francis

    2010-01-01

    Respiratory syncytial virus (RSV) bronchiolitis has been associated with later development of asthma, wheezing, abnormal pulmonary function, and sensitization. Our aim was to determine the differential effect within monozygotic (MZ) twin pairs discordant for severe RSV bronchiolitis in infancy...

  7. 9 CFR 113.55 - Detection of extraneous agents in Master Seed Virus.

    Science.gov (United States)

    2010-01-01

    ... Master Seed Virus. 113.55 Section 113.55 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... STANDARD REQUIREMENTS Ingredient Requirements § 113.55 Detection of extraneous agents in Master Seed Virus... Seed Virus (MSV) shall be tested as prescribed in this section. A MSV found unsatisfactory by any...

  8. ITS-rDNA phylogeny of Colletotrichum spp. causal agent of apple Glomerella leaf spot Filogenia por ITS-rDNA de Colletotrichum spp., agente causal da mancha foliar da Gala em macieira

    Directory of Open Access Journals (Sweden)

    Diorvania Ribeiro Giaretta

    2010-04-01

    Full Text Available Several diseases have affected apple production, among them there is Glomerella leaf spot (GLS caused by Colletotrichum spp. The first report of this disease in apple was in plants nearby citrus orchards in São Paulo State, Brazil. The origin of this disease is still not clear, and studies based on the molecular phylogeny could relate the organisms evolutionarily and characterize possible mechanisms of divergent evolution. The amplification of 5.8S-ITS (Internal Transcribed Spacer of rDNA of 51 pathogenic Colletotrichum spp. isolates from apples, pineapple guava and citrus produced one fragment of approximately 600 bases pairs (bp for all the isolates analyzed. The amplified fragments were cleaved with restriction enzymes, and fragments from 90 to 500bp were obtained. The sequencing of this region allowed the generation of a phylogenetic tree, regardless of their hosts, and 5 isolated groups were obtained. From the "in silico" comparison, it was possible to verify a variation from 93 to 100% of similarity between the sequences studied and the Genbank data base. The causal agent of GLS is nearly related (clustered to isolates of pineapple guava and to the citrus isolates used as control.A produção de maçã vem sendo comprometida pela ocorrência de muitas doenças, entre as quais se destaca a Mancha Foliar de Glomerella (MFG, causada por Colletotrichum spp. O primeiro relato dessa doença em maçã foi registrado em plantas próximas a pomares de citrus no Estado de São Paulo, Brasil. A origem da MFG ainda não está bem clara, e estudos baseados na filogenia permitirão relacionar o organismo evolutivamente, possibilitando caracterizar possíveis mecanismos divergentes de evolução. A amplificação da região 5.8S-ITS (espaçador interno transcrito do rDNA de 51 isolados de Colletotrichum patogênicos em de maçã, goiabeira serrana e citrus produziu um fragmento de aproximadamente 600 pares de bases (pb para todos os isolados analisados

  9. Multi-agent model of hepatitis C virus infection.

    Science.gov (United States)

    Wasik, Szymon; Jackowiak, Paulina; Figlerowicz, Marek; Blazewicz, Jacek

    2014-02-01

    The objective of this study is to design a method for modeling hepatitis C virus (HCV) infection using multi-agent simulation and to verify it in practice. In this paper, first, the modeling of HCV infection using a multi-agent system is compared with the most commonly used model type, which is based on differential equations. Then, the implementation and results of the model using a multi-agent simulation is presented. To find the values of the parameters used in the model, a method using inverted simulation flow and genetic algorithm is proposed. All of the data regarding HCV infection are taken from the paper describing the model based on the differential equation to which the proposed method is compared. Important advantages of the proposed method are noted and demonstrated: these include flexibility, clarity, re-usability and the possibility to model more complex dependencies. Then, the simulation framework that uses the proposed approach is successfully implemented in C++ and is verified by comparing it to the approach based on differential equations. The verification proves that an objective function that performs the best is the function that minimizes the maximal differences in the data. Finally, an analysis of one of the already known models is performed, and it is proved that it incorrectly models a decay in the hepatocytes number by 40%. The proposed method has many advantages in comparison to the currently used model types and can be used successfully for analyzing HCV infection. With almost no modifications, it can also be used for other types of viral infections. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Multisource causal data mining

    Science.gov (United States)

    Woodley, Robert; Gosnell, Michael; Shallenberger, Kevin

    2012-06-01

    Analysts are faced with mountains of data, and finding that relevant piece of information is the proverbial needle in a haystack, only with dozens of haystacks. Analysis tools that facilitate identifying causal relationships across multiple data sets are sorely needed. 21st Century Systems, Inc. (21CSi) has initiated research called Causal-View, a causal datamining visualization tool, to address this challenge. Causal-View is built on an agent-enabled framework. Much of the processing that Causal-View will do is in the background. When a user requests information, Data Extraction Agents launch to gather information. This initial search is a raw, Monte Carlo type search designed to gather everything available that may have relevance to an individual, location, associations, and more. This data is then processed by Data- Mining Agents. The Data-Mining Agents are driven by user supplied feature parameters. If the analyst is looking to see if the individual frequents a known haven for insurgents he may request information on his last known locations. Or, if the analyst is trying to see if there is a pattern in the individual's contacts, the mining agent can be instructed with the type and relevance of the information fields to look at. The same data is extracted from the database, but the Data Mining Agents customize the feature set to determine causal relationships the user is interested in. At this point, a Hypothesis Generation and Data Reasoning Agents take over to form conditional hypotheses about the data and pare the data, respectively. The newly formed information is then published to the agent communication backbone of Causal- View to be displayed. Causal-View provides causal analysis tools to fill the gaps in the causal chain. We present here the Causal-View concept, the initial research into data mining tools that assist in forming the causal relationships, and our initial findings.

  11. Virus como inductores de neoplasias cutáneas Viruses as agents inducing cutaneous neoplasms

    Directory of Open Access Journals (Sweden)

    Francisco Bravo Puccio

    2013-03-01

    Full Text Available El rol oncogénico de los virus en las neoplasias cutáneas es conocido por el hombre desde hace más de un siglo, cuando se atribuía el origen de la verruga vulgar al virus papiloma humano (VPH. En la actualidad, las neoplasias inducidas por virus pueden agruparse en tumores sólidos y procesos linfoproliferativos. Destacan entre los primeros el VPH, del cual ahora conocemos numerosos serotipos, cada uno vinculado a una neoplasia específica, el herpesvirus humano tipo 8 que produce el sarcoma de Kaposi y el poliomavirus vinculado al carcinoma de Merkel. Entre los procesos linfoproliferativos debemos mencionar al virus linfotrópico de células T humanas tipo 1 (HTLV-1 responsable de los linfomas de células T, en los cuales el compromiso cutáneo es inespecífico, con un amplio espectro de presentaciones clínicas y, que por consiguiente, plantean un reto para el diagnóstico diferencial. En este grupo también se encuentra el virus Epstein Barr vinculado a los linfomas nasales de Células NK/T y a los linfomas tipo Hidroa, de reciente descripción. En esta era en la que lo genético y lo molecular priman en las investigaciones en cáncer, no podemos dejar de lado el concepto de neoplasia como resultado de la infección por un agente viral, lo que abre una nueva veta de posibilidades de tratamiento anticanceroso basado en medicamentos antiviralesThe oncogenic role of viruses in cutaneous neoplasms has been known by humankind for more than a century, when the origin of the common wart, or verruca vulgaris, was attributed to the human papilloma virus (HPV. Currently, virus-induced cutaneous neoplasms may be grouped into solid tumors and lymphoproliferative disorders. HPV, from which various serotypes are now known, each being linked to a specific neoplasm, the human herpes virus type 8 producing Kaposi sarcoma, and the Merkel cell polyomavirus, highlight among the first group. Regarding the lymphoproliferative disorders, we should mention the

  12. [Causal agents of onychomycosis].

    Science.gov (United States)

    Canteros, G E; Davel, G O; Vivot, W

    1994-01-01

    The results obtained with 307 specimens from putatively immunocompetent patients between May 1991 and May 1992 were reviewed, to determine the frequency of isolation of fungal species causing onychomycoses. Sixty eight percent of the specimen were positive for microscopic examination and/or cultures. Onychomycoses occurred with double frequency in women than in men (Table 1), and 77% of cases were diagnosed in patients aged between 30 and 70 years (Figure 1). Out of 182 patients with positive cultures, 60% were affected by dermatophytes and 39% by yeasts; molds (Aspergillus spp.) were isolated in only two cases (Table 3). Neither Corynebacterium spp., nor Malasezzia furfur were detected. In toe nails Trichophyton rubrum predominated over yeasts being isolated in 72.9% of the cases; yeasts other than Candida albicans were isolated in 12.3%, Trichophyton mentagrophytes in 10%, while Aspergillus spp., C. albicans and Epidermophyton floccosum in only 1.6%. On the other hand, in finger nails yeasts predominated: C. albicans was isolated in 46.7% of cases, other yeasts in 43.3%; and T. rubrum in the remaining 10%. Out of 41 isolations of yeasts other than C. albicans, 42% were C. parapsilosis, 16% Debaryomyces hansenii, 6% C. pulcherrima, 6% Trichosporum cutaneum and 6% C. famata (Figure 2).

  13. Nutritional Capability of and Substrate Suitability for Pseudogymnoascus destructans, the Causal Agent of Bat White-Nose Syndrome

    Science.gov (United States)

    Raudabaugh, Daniel B.; Miller, Andrew N.

    2013-01-01

    Pseudogymnoascus destructans, the causal agent of bat white-nose syndrome, has caused nearly six million deaths in North American bats since its introduction into the United States in 2006. Current research has shown that caves can harbor P. destructans even after the infected bats are removed and bats no longer visit or inhabit previously infected caves. Our research focuses on elucidating reservoir requirements by investigating the nutritional capabilities of and substrate suitability requirements for six different P. destructans isolates from various localities including Illinois, Indiana, New York (Type specimen), and Pennsylvania. Enzyme assays implicate that both urease and b-glucosidase appear to be constitutive, lipase and esterase activity were more rapid than proteinase activity on 6% gelatin, gelatin degradation was accompanied by medium alkalinization, the reduction of thiosulfate generated hydrogen sulfide gas, chitinase and manganese dependent peroxidase activity were not visually demonstrated within eight weeks, and keratinase activity was not evident at pH 8 within eight weeks. We demonstrate that all P. destructans isolates are capable of growth and sporulation on dead fish, insect, and mushroom tissues. Sole nitrogen source assays demonstrated that all P. destructans isolates exhibit Class 2 nitrogen utilization and that growth-dependent interactions occur among different pH and nitrogen sources. Substrate suitability assays demonstrated that all isolates could grow and sporulate on media ranging from pH 5–11 and tolerated media supplemented with 2000 mg/L of calcium and 700 mg/L of three separated sulfur compounds: thiosulfate L-cysteine, and sulfite. All isolates were intolerant to PEG-induced matric potential with delayed germination and growth at −2.5 MPa with no visible germination at −5 MPa. Interestingly, decreasing the surface tension with Tween 80 permitted germination and growth of P. destructans in −5 MPa PEG medium within 14

  14. Efecto biofungicida del gel de Aloe vera sobre Mycosphaerella fijiensis, agente causal de la Sigatoka negra en Musa (AAA

    Directory of Open Access Journals (Sweden)

    Edwin Jaramillo Aguilar

    2017-01-01

    Full Text Available El objetivo de este trabajo fue evaluar a nivel in vitro la actividad antifúngica del gel de Aloe vera sobre el crecimiento micelial de Mycosphaerella fijiensis. Se utilizó la técnica de envenenamiento en el medio de cultivo PDA para determinar la actividad antifúngica del gel. El diseño utilizado fue completamente al azar, con siete tratamientos y tres repeticiones. En los tratamientos se utilizó un fungicida químico comercial (propiconazol, a 250 ppm y 500 ppm; un biofungicida comercial (Trichoderma sp. a 500 ppm y 1000 ppm; ambos productos se usaron como testigo químico y biológico, respectivamente; el gel de Aloe vera a 500 ppm y 1000 ppm; y un testigo absoluto. Se determinó diferencias significativas entre los tratamientos (ANOVA, El test de Tukey demostró que todos los tratamientos registraron diferencia significativa (p ≤ 0,05 con respecto al testigo absoluto. El propiconazol presentó el mayor porcentaje de inhibición del micelio (73,10%; el test de Tukey y el porcentaje de inhibición del micelio presentaron valores similares en el control del crecimiento del hongo a los 30 días de inoculación, en los tratamientos gel de Aloe vera y el T6 de Trichoderma sp. Los resultados sugieren que el Aloe vera podría ser un adecuado biofungicida para el control de Mycosphaerella fijiensis, agente causal de la Sigatoka negra.

  15. Parasitosis intestinales en Argentina: principales agentes causales encontrados en la población y en el ambiente

    Directory of Open Access Journals (Sweden)

    María M Juárez

    Full Text Available Las parasitosis intestinales se encuentran ampliamente distribuidas en el mundo, con mayor prevalencia en los países en desarrollo. Principalmente afectan a los niños, en los que además provocan disminución del desarrollo físico y mental, situación que puede potenciarse enormemente cuando se suma a un estado nutricional deficiente. La Organización Mundial de la Salud las considera una de las principales causas de morbilidad, estrechamente ligada a la pobreza y relacionada con inadecuada higiene personal, incorrecta manipulación de los alimentos crudos, falta de servicios sanitarios, falta de provisión de agua potable y contaminación fecal del ambiente. Algunas enfermedades parasitarias se vinculan con condiciones de transmisión que existen universalmente, por lo que son cosmopolitas, mientras que otras tienen distribución geográfica variable. En los últimos años, debido a la globalización, el movimiento de personas de zonas endémicas a regiones no endémicas ha permitido la diseminación de ciertas parasitosis. Y aunque también influyen en la frecuencia de algunas de estas enfermedades las costumbres de los pueblos, las condiciones ambientales son un factor determinante para la supervivencia de los parásitos. En nuestro país, debido a la diversidad de suelos y condiciones climáticas que existen, es posible hallar variedad de agentes causales de estas parasitosis. El objetivo de este trabajo fue realizar una revisión bibliográfica de los agentes parasitarios causantes de enfermedades entéricas encontrados en la República Argentina, tanto en materia fecal de personas como en el ambiente, ya que la contaminación parasitaria de este último constituye un indicador directo del riesgo de infección por parásitos intestinales.

  16. Cucumber mosaic virus associated RNA 5: causal agent for tomato necrosis.

    Science.gov (United States)

    Kaper, J M; Waterworth, H E

    1977-04-22

    A small replicating RNA, encapsidated with and dependent on, but not part of the viral genome, modifies disease expression depending on the host. In tomato plants, it causes a lethal necrotic disease which is probably the same as that which, in 1972, destroyed most of the field tomato crop in large regions of the French Alsace.

  17. Murcha do manjericão (Ocimum basilicum no Brasil: agente causal, círculo de plantas hospedeiras e transmissão via semente Sweet basil (Ocimum basilicum wilt in Brazil: causal agent, host range and seed transmission

    Directory of Open Access Journals (Sweden)

    Ailton Reis

    2007-06-01

    Full Text Available O manjericão (Ocimum basilicum L. é uma hortaliça da família Lamiaceae, utilizada na culinária ou como matéria prima para a indústria de fármacos e óleos essenciais. Amostras de plantas de manjericão apresentando sintomas de murcha, seca de hastes e podridão de colo foram coletadas na área rural de Brazlândia (DF durante a estação chuvosa de 2005. Outras duas amostras foram coletadas em plantas cultivadas em campo aberto e casas de vegetação na região de Ponte Alta (DF. Isolados de um fungo, identificado como Fusarium oxysporum, foram obtidos em todas as amostras. Testes de patogenicidade foram conduzidos com mudas das cultivares O. basilicum 'Dark Opal' e 'Italian Large Leaf', e de acessos das espécies O. americanum L. (manjericão de folha miúda, O. campechianum Mill. (alfavaca, Origanum manjorana L. (manjerona, Origanum vulgare L. (orégano, Mentha arvensis L. (menta, Coleus blumei Benth. (tapete, Leonorus sibiricus L. (rubim e Leonotis nepetaefolia (L. W.T. Aiton (cordão-de-frade. Todos os isolados fúngicos mostraram-se altamente virulentos sobre as duas cultivares de manjericão. Em O. campechianum e O. americanum os isolados causaram apenas suave escurecimento vascular e leve redução de crescimento, sendo avirulentos sobre acessos das espécies O. manjorana, O. vulgare, M. arvensis, C. blumei, L. sibiricus e L. nepetaefolia. Este conjunto de dados indicou que o agente causal da doença é o fungo F. oxysporum f. sp. basilici, constituindo-se no primeiro registro formal deste patógeno no Brasil. Os lotes de sementes utilizados nas áreas de ocorrência da doença foram submetidos a um teste de sanidade visando verificar a presença do patógeno. O fungo F. oxysporum f. sp. basilici foi detectado em quatro dos seis lotes e os isolados obtidos das sementes contaminadas mostraram similar sintomatologia e um idêntico perfil de virulência aos verificados em campo e casa de vegetação, sugerindo que as sementes

  18. Specific PCR detection of Fusarium oxysporum f. sp. raphani: a causal agent of Fusarium wilt on radish plants.

    Science.gov (United States)

    Kim, H; Hwang, S-M; Lee, J H; Oh, M; Han, J W; Choi, G J

    2017-08-01

    Fusarium oxysporum, a causal agent of Fusarium wilt, is one of the most important fungal pathogens worldwide, and detection of F. oxysporum DNA at the forma specialis level is crucial for disease diagnosis and control. In this study, two novel F. oxysporum f. sp. raphani (For)-specific primer sets were designed, FOR1-F/FOR1-R and FOR2-F/FOR2-R, to target FOQG_17868 and FOQG_17869 ORFs, respectively, which were selected based on the genome comparison of other formae speciales of F. oxysporum including conglutinans, cubense, lycopersici, melonis, and pisi. The primer sets FOR1-F/FOR1-R and FOR2-F/FOR2-R that amplified a 610- and 425-bp DNA fragment, respectively, were specific to For isolates which was confirmed using a total of 40 F. oxysporum isolates. From infected plants, the FOR2-F/FOR2-R primer set directly detected the DNA fragment of For isolates even when the radish plants were collected in their early stage of disease development. Although the loci targeted by the For-specific primer sets were not likely involved in the pathogenesis, the primer set FOR2-F/FOR2-R is available for the determination of pathogenicity of radish-infecting F. oxysporum isolates. This study is the first report providing novel primer sets to detect F. oxysporum f. sp. raphani. Because plant pathogenic Fusarium oxysporum has been classified into special forms based on its host specificity, identification of F. oxysporum usually requires a pathogenicity assay as well as knowledge of the morphological characteristics. For rapid and reliable diagnosis, this study provides PCR primer sets that specifically detect Fusarium oxysporum f. sp. raphani (For) which is a devastating pathogen of radish plants. Because one of the primer sets directly detected the DNA fragment of For isolates from infected plants, the specific PCR method demonstrated in this study will provide a foundation for integrated disease management practices in commodity crops. © 2017 The Society for Applied Microbiology.

  19. Viruses as new agents of organomineralization in the geological record.

    Science.gov (United States)

    Pacton, Muriel; Wacey, David; Corinaldesi, Cinzia; Tangherlini, Michael; Kilburn, Matt R; Gorin, Georges E; Danovaro, Roberto; Vasconcelos, Crisogono

    2014-07-03

    Viruses are the most abundant biological entities throughout marine and terrestrial ecosystems, but little is known about virus-mineral interactions or the potential for virus preservation in the geological record. Here we use contextual metagenomic data and microscopic analyses to show that viruses occur in high diversity within a modern lacustrine microbial mat, and vastly outnumber prokaryotes and other components of the microbial mat. Experimental data reveal that mineral precipitation takes place directly on free viruses and, as a result of viral infections, on cell debris resulting from cell lysis. Viruses are initially permineralized by amorphous magnesium silicates, which then alter to magnesium carbonate nanospheres of ~80-200 nm in diameter during diagenesis. Our findings open up the possibility to investigate the evolution and geological history of viruses and their role in organomineralization, as well as providing an alternative explanation for enigmatic carbonate nanospheres previously observed in the geological record.

  20. Macromolecular Antiviral Agents against Zika, Ebola, SARS, and Other Pathogenic Viruses

    DEFF Research Database (Denmark)

    Schandock, Franziska; Riber, Camilla Frich; Röcker, Annika

    2017-01-01

    . This work performs selection of synthetic polymers as novel broadly active agents and demonstrates activity of these polymers against Zika, Ebola, Lassa, Lyssa, Rabies, Marburg, Ebola, influenza, herpes simplex, and human immunodeficiency viruses. Results presented herein offer structure...

  1. How accurate are diagnostic tools for Epstein-Barr virus (EBV) to establish causal association of an uncommon clinical condition with EBV?

    Science.gov (United States)

    Neocleous, C; Adramerina, A; Spanou, C; Spyrou, G; Mitsios, A; Dragoumi, M; Tzanetis, F

    2013-01-01

    Epstein-Barr virus (EBV) infection has been implicated as a possible cause of a wide range of clinical conditions in children and young adults. In uncommon clinical conditions, where clinical experience is missing, it is important to evaluate both the biological plausibility and the virological basis that substantiates their causal association with EBV. By reviewing the diagnostic procedures performed in the diagnosis of EBV infection in case reports concerning uncommon clinical conditions causally related to EBV infection in children and young adults, the aim of the present study was to discuss the limitations of the diagnostic procedure used to establish EBV diagnosis, which may cause false-positive results and compromise the reliability of such a diagnosis. We should be aware not only of the nuances of serological tests and virus detection tests for latent viruses such as EBV, but also of the risk of using them alone or in combination with molecular methods as the sole mean for establishing a causal relation between EBV infection and an uncommon clinical condition. Accurate laboratory tests for EBV detection, strict criteria for EBV infection diagnosis, and a cumulative clinical experience coupled with biological plausibility and experimental data are needed to avoid a possible coincidental association between several clinical manifestations, mainly uncommon clinical conditions, and EBV infection. Epstein-Barr virus; diagnostics; uncommon condition.

  2. The puzzle of new etiological agents in the Americas: Punta del Toro virus another piece?

    Directory of Open Access Journals (Sweden)

    Salim Mattar V

    2017-01-01

    Full Text Available In a recent study of undifferentiated tropical fevers in an endemic area of Colombia, it was shown that not all acute fevers are caused by the dengue virus (1. The complex clinical-epidemiological panorama of tropical fevers has become a puzzle of difficult resolution due to the appearance of new etiological agents in the Americas such as Chikungunya and Zika. For the differential diagnosis Hantavirus, Arenavirus, Orupuche, tick thrombocytopenic virus, Heartland virus, leptospira and malaria should be considered.

  3. A review of the Mycrocylus ulei Ascomycetes fungus, causative agent of South American rubber-leaf blight Revisión sobre el hongo Microcyclus ulei, agente causal del mal suramericano de la hoja del caucho

    OpenAIRE

    Ancízar Aristizábar Fabio; Montoya Castaño Dolly; García Romero Ibonne Aydee

    2006-01-01

    The Microcyclus ulei Ascomycetes fungus is the causal agent of south-American leaf blight (SALB), this being one of the most important diseases affecting the natural rubber tree (Hevea brasiliensis) in Latina-America and has been responsible for numerous economic losses. This fungus has presented high physiological variability, suggesting its great adaptability. HCN tolerance has been described as being one of the mechanisms associated with its virulence. Resistant Hevea clones have been obta...

  4. Causality in Classical Electrodynamics

    Science.gov (United States)

    Savage, Craig

    2012-01-01

    Causality in electrodynamics is a subject of some confusion, especially regarding the application of Faraday's law and the Ampere-Maxwell law. This has led to the suggestion that we should not teach students that electric and magnetic fields can cause each other, but rather focus on charges and currents as the causal agents. In this paper I argue…

  5. Reacción de variedades de frijol a la inoculación del nematodo Aphelenchoides besseyi, agente causal de la falsa mancha angular

    OpenAIRE

    Barrantes-Santamaría, Walter; Araya Fernández, Carlos Manuel

    2007-01-01

    Reacción de variedades de frijol a la inoculación artifi cial de Aphelenchoides besseyi, agente causal de la falsa mancha angular. Especímenes adultos y juveniles de A. besseyi provenientes de cultivo in vitro se inocularon sobre el follaje de plantas de frijol de las variedades Bribri, Huetar, Telire y Chirripó Rojo. Las edades de las plantas inoculadas en el invernadero fueron de diez, 20 y 30 días después de siembra (dds). Los bioensayos se realizaron en los invernaderos de la Escuela de C...

  6. A Distributed Agent Architecture for a Computer Virus Immune System

    National Research Council Canada - National Science Library

    Harmer, Paul

    2000-01-01

    .... Information protection and information assurance are vital components required for achieving superiority in the Infosphere, but these goals are threatened by the exponential birth rate of new computer viruses...

  7. A novel fungal hyperparasite of Puccinia striiformis f. sp. tritici, the causal agent of wheat stripe rust.

    Directory of Open Access Journals (Sweden)

    Gangming Zhan

    Full Text Available Puccinia striiformis f. sp. tritici (Pst, the causal fungus of wheat stripe rust, was previously reported to be infected by Lecanicillium lecanii, Microdochium nivale and Typhula idahoensis. Here, we report a novel hyperparasite on Pst. This hyperparasitic fungus was identified as Cladosporium cladosporioides (Fresen. GA de Vries based on morphological characteristics observed by light and scanning electron microscopy together with molecular data. The hyperparasite reduced the production and viability of urediniospores and, therefore, could potentially be used for biological control of wheat stripe rust.

  8. Nuclear polyhedrosis virus as biological control agent of Spodoptera exigua

    NARCIS (Netherlands)

    Smits, P.H.

    1987-01-01

    Several aspects of the control of the beet armyworm, Spodopteraexigua (Hübner) (Lepidoptera: Noctuidae) in greenhouse crops with nuclear polyhedrosis viruses (NPVs) (Baculoviridae, subgroup A) were studied.

    Beet armyworm behaviour was observed in various

  9. Resistance of Berne virus to physical and chemical agents

    NARCIS (Netherlands)

    Horzinek, M.C.; Weiss, Marianne

    1985-01-01

    Thermal inactivation of Berne virus proceeded at a linear rate between 31°C and 43°C. Storage at temperatures lower than −20°C preserved the infectivity, while at 4°C appreciable loss occurred between 92 and 185 days. Freeze-drying or desiccation at 22°C caused only insignificant loss of

  10. Vesicular stomatitis virus as an oncolytic agent against pancreatic ductal adenocarcinoma.

    Science.gov (United States)

    Murphy, Andrea M; Besmer, Dahlia M; Moerdyk-Schauwecker, Megan; Moestl, Natascha; Ornelles, David A; Mukherjee, Pinku; Grdzelishvili, Valery Z

    2012-03-01

    Vesicular stomatitis virus (VSV) is a promising oncolytic agent against a variety of cancers. However, it has never been tested in any pancreatic cancer model. Pancreatic ductal adenocarcinoma (PDA) is the most common and aggressive form of pancreatic cancer. In this study, the oncolytic potentials of several VSV variants were analyzed in a panel of 13 clinically relevant human PDA cell lines and compared to conditionally replicative adenoviruses (CRAds), Sendai virus and respiratory syncytial virus. VSV variants showed oncolytic abilities superior to those of other viruses, and some cell lines that exhibited resistance to other viruses were successfully killed by VSV. However, PDA cells were highly heterogeneous in their susceptibility to virus-induced oncolysis, and several cell lines were resistant to all tested viruses. Resistant cells showed low levels of very early VSV RNA synthesis, indicating possible defects at initial stages of infection. In addition, unlike permissive PDA cell lines, most of the resistant cell lines were able to both produce and respond to interferon, suggesting that intact type I interferon responses contributed to their resistance phenotype. Four cell lines that varied in their permissiveness to VSV-ΔM51 and CRAd dl1520 were tested in mice, and the in vivo results closely mimicked those in vitro. While our results demonstrate that VSV is a promising oncolytic agent against PDA, further studies are needed to better understand the molecular mechanisms of resistance of some PDAs to oncolytic virotherapy.

  11. Effect of temperature and photoperiod on the in vitro germination of conidia of Botrytis squamosa, the causal agent of Botrytis leaf blight of onion

    Directory of Open Access Journals (Sweden)

    Leandro Luiz Marcuzzo

    Full Text Available ABSTRACT Temperature and photoperiod have a direct effect on spore germination and, for Botrytis squamosa, there is scare information on this subject. Learning the biology of the causal agent has a great importance to understand the development of the disease in the field, as well to take control measures. With the aim of evaluating the influence of temperature and photoperiod on B. squamosa conidial germination, an experiment was conducted in a completely randomized design with four replicates. A 0.1-ml suspension of 1.65x105 conidia per ml was added and spread on Petri dishes containing 1% water-agar. The Petri dishes were placed in BOD incubators adjusted to 10, 15, 20, 25 and 30°C without light, and the percentage of germination of 100 conidia was evaluated under an optical microscope by measuring the germ tube after 24 hours of incubation. In a second moment, this experiment was repeated by incubating the spores at 23°C and photoperiods of 0, 6, 12, 18 and 24 hours, and by evaluating the percentage of germination after 24 hours. Results showed that the highest germination percentages can be obtained in the temperature range between 10 (79.75% and 30°C (92.5%, and the optimum temperature for germination is 23°C. In relation to photoperiod, the highest germination percentage (94% was obtained without light, which indicates that B. squamosa germination is favored by shorter periods of light. Thus, the information obtained on the biology of the causal agent of botrytis leaf blight allows better understand the epidemiology of this disease, and such results can be used to help develop a disease forecasting system.

  12. Chloroquine, an Endocytosis Blocking Agent, Inhibits Zika Virus Infection in Different Cell Models

    Directory of Open Access Journals (Sweden)

    Rodrigo Delvecchio

    2016-11-01

    Full Text Available Zika virus (ZIKV infection in utero might lead to microcephaly and other congenital defects. Since no specific therapy is available thus far, there is an urgent need for the discovery of agents capable of inhibiting its viral replication and deleterious effects. Chloroquine is widely used as an antimalarial drug, anti-inflammatory agent, and it also shows antiviral activity against several viruses. Here we show that chloroquine exhibits antiviral activity against ZIKV in Vero cells, human brain microvascular endothelial cells, human neural stem cells, and mouse neurospheres. We demonstrate that chloroquine reduces the number of ZIKV-infected cells in vitro, and inhibits virus production and cell death promoted by ZIKV infection without cytotoxic effects. In addition, chloroquine treatment partially reveres morphological changes induced by ZIKV infection in mouse neurospheres.

  13. Chloroquine, an Endocytosis Blocking Agent, Inhibits Zika Virus Infection in Different Cell Models.

    Science.gov (United States)

    Delvecchio, Rodrigo; Higa, Luiza M; Pezzuto, Paula; Valadão, Ana Luiza; Garcez, Patrícia P; Monteiro, Fábio L; Loiola, Erick C; Dias, André A; Silva, Fábio J M; Aliota, Matthew T; Caine, Elizabeth A; Osorio, Jorge E; Bellio, Maria; O'Connor, David H; Rehen, Stevens; de Aguiar, Renato Santana; Savarino, Andrea; Campanati, Loraine; Tanuri, Amilcar

    2016-11-29

    Zika virus (ZIKV) infection in utero might lead to microcephaly and other congenital defects. Since no specific therapy is available thus far, there is an urgent need for the discovery of agents capable of inhibiting its viral replication and deleterious effects. Chloroquine is widely used as an antimalarial drug, anti-inflammatory agent, and it also shows antiviral activity against several viruses. Here we show that chloroquine exhibits antiviral activity against ZIKV in Vero cells, human brain microvascular endothelial cells, human neural stem cells, and mouse neurospheres. We demonstrate that chloroquine reduces the number of ZIKV-infected cells in vitro, and inhibits virus production and cell death promoted by ZIKV infection without cytotoxic effects. In addition, chloroquine treatment partially reveres morphological changes induced by ZIKV infection in mouse neurospheres.

  14. Virus como inductores de neoplasias cutáneas Viruses as agents inducing cutaneous neoplasms

    OpenAIRE

    Francisco Bravo Puccio

    2013-01-01

    El rol oncogénico de los virus en las neoplasias cutáneas es conocido por el hombre desde hace más de un siglo, cuando se atribuía el origen de la verruga vulgar al virus papiloma humano (VPH). En la actualidad, las neoplasias inducidas por virus pueden agruparse en tumores sólidos y procesos linfoproliferativos. Destacan entre los primeros el VPH, del cual ahora conocemos numerosos serotipos, cada uno vinculado a una neoplasia específica, el herpesvirus humano tipo 8 que produce el sarcoma d...

  15. Cladosporium cladosporioides and Cladosporium pseudocladosporioides as potential new fungal antagonists of Puccinia horiana Henn., the causal agent of chrysanthemum white rust.

    Directory of Open Access Journals (Sweden)

    David Eduardo Torres

    Full Text Available Puccinia horiana Hennings, the causal agent of chrysanthemum white rust, is a worldwide quarantine organism and one of the most important fungal pathogens of Chrysanthemum × morifolium cultivars, which are used for cut flowers and as potted plants in commercial production regions of the world. It was previously reported to be controlled by Lecanicillium lecanii, Cladosporium sphaerospermum, C. uredinicola and Aphanocladium album, due to their antagonistic and hyperparasitic effects. We report novel antagonist species on Puccinia horiana. Fungi isolated from rust pustules in a commercial greenhouse from Villa Guerrero, México, were identified as Cladosporium cladosporioides and Cladosporium pseudocladosporioides based upon molecular analysis and morphological characters. The antagonism of C. cladosporioides and C. pseudocladosporioides on chrysanthemum white rust was studied using light and electron microscopy in vitro at the host/parasite interface. Cladosporium cladosporioides and C. pseudocladosporioides grew towards the white rust teliospores and colonized the sporogenous cells, but no direct penetration of teliospores was observed; however, the structure and cytoplasm of teliospores were altered. The two Cladosporium spp. were able to grow on media containing laminarin, but not when chitin was used as the sole carbon source; these results suggest that they are able to produce glucanases. Results from the study indicate that both Cladosporium species had potential as biological control agents of chrysanthemum white rust.

  16. Cladosporium cladosporioides and Cladosporium pseudocladosporioides as potential new fungal antagonists of Puccinia horiana Henn., the causal agent of chrysanthemum white rust.

    Science.gov (United States)

    Torres, David Eduardo; Rojas-Martínez, Reyna Isabel; Zavaleta-Mejía, Emma; Guevara-Fefer, Patricia; Márquez-Guzmán, G Judith; Pérez-Martínez, Carolina

    2017-01-01

    Puccinia horiana Hennings, the causal agent of chrysanthemum white rust, is a worldwide quarantine organism and one of the most important fungal pathogens of Chrysanthemum × morifolium cultivars, which are used for cut flowers and as potted plants in commercial production regions of the world. It was previously reported to be controlled by Lecanicillium lecanii, Cladosporium sphaerospermum, C. uredinicola and Aphanocladium album, due to their antagonistic and hyperparasitic effects. We report novel antagonist species on Puccinia horiana. Fungi isolated from rust pustules in a commercial greenhouse from Villa Guerrero, México, were identified as Cladosporium cladosporioides and Cladosporium pseudocladosporioides based upon molecular analysis and morphological characters. The antagonism of C. cladosporioides and C. pseudocladosporioides on chrysanthemum white rust was studied using light and electron microscopy in vitro at the host/parasite interface. Cladosporium cladosporioides and C. pseudocladosporioides grew towards the white rust teliospores and colonized the sporogenous cells, but no direct penetration of teliospores was observed; however, the structure and cytoplasm of teliospores were altered. The two Cladosporium spp. were able to grow on media containing laminarin, but not when chitin was used as the sole carbon source; these results suggest that they are able to produce glucanases. Results from the study indicate that both Cladosporium species had potential as biological control agents of chrysanthemum white rust.

  17. Effect of Two Biological Formulations Based on Bacillus subtilis and Pseudomonas fluorescens on Control of Didymella applanata, the Causal Agent of Red Raspberry Cane Spur Blight

    Directory of Open Access Journals (Sweden)

    Margarita Shternshis

    2016-01-01

    Full Text Available In vitro and in vivo studies were conducted to estimate the efficacy of the two microbial formulations based on Bacillus subtilis Cohn. and Pseudomonas fluorescens Mig. on the fungus Didymella applanata (Niessl. Sacc., the causal agent of red raspberry (Rubus idaeus L. spur blight. In vitro, both bacteria reduced the growth of D. applanata. In inoculation experiments with raspberry canes in two cultivars with different susceptibility to D. applanata, these antagonistic bacteria suppressed fungal development by reducing the lesions area and the number of D. applanata fruiting bodies. Field trials of two biological formulations under natural conditions showed a significant suppression of the disease. B. subtilis and P. fluorescens included in the formulations revealed antagonistic activity towards D. applanata that depended on the red raspberry cultivar and weather conditions. In all cases, B. subtilis showed better results than P. fluorescens in biocontrol of the raspberry spur blight. This study demonstrated for the first time the ability of the biocontrol agents B. subtilis and P. fluorescens to suppress red raspberry cane spur blight, a serious worldwide disease.

  18. Diversity of endophytic fungal community of cacao (Theobroma cacao L.) and biological control of Crinipellis perniciosa, causal agent of Witches' Broom Disease.

    Science.gov (United States)

    Rubini, Marciano R; Silva-Ribeiro, Rute T; Pomella, Alan W V; Maki, Cristina S; Araújo, Welington L; Dos Santos, Deise R; Azevedo, João L

    2005-01-01

    The basidiomycete fungus Crinipellis perniciosa (Stahel) Singer is the causal agent of Witches' Broom Disease of Cacao (Theobromacacao L.) which is the main factor limiting cacao production in the Americas. Pod losses of up to 90% are experienced in affected areas as evidenced by the 50% drop in production in Bahia province, Brazil following the arrival of the C. perniciosa in the area in 1989. The disease has proven particularly difficult to control and many farmers in affected areas have given up cacao cultivation. In order to evaluate the potential of endophytes as a biological control agent of this phytopathogen, the endophytic fungal community of resistant and susceptible cacao plants as well as affected branches was studied between 2001 and 2002. The fungal community was identified by morphological traits and rDNA sequencing as belonging to the genera Acremonium, Blastomyces, Botryosphaeria, Cladosporium, Colletotrichum, Cordyceps, Diaporthe, Fusarium, Geotrichum, Gibberella, Gliocladium, Lasiodiplodia, Monilochoetes, Nectria, Pestalotiopsis, Phomopsis, Pleurotus, Pseudofusarium, Rhizopycnis, Syncephalastrum, Trichoderma, Verticillium and Xylaria. These fungi were evaluated both in vitro and in vivo by their ability to inhibit C. perniciosa. Among these, some were identified as potential antagonists, but only one fungus (Gliocladium catenulatum) reduced the incidence of Witches' Broom Disease in cacao seedlings to 70%.

  19. Causal universe

    CERN Document Server

    Ellis, George FR; Pabjan, Tadeusz

    2013-01-01

    Written by philosophers, cosmologists, and physicists, this collection of essays deals with causality, which is a core issue for both science and philosophy. Readers will learn about different types of causality in complex systems and about new perspectives on this issue based on physical and cosmological considerations. In addition, the book includes essays pertaining to the problem of causality in ancient Greek philosophy, and to the problem of God's relation to the causal structures of nature viewed in the light of contemporary physics and cosmology.

  20. Causal Agents of Mycobacterial Diseases in Freshwater Ornamental Fish and their Importance for Human Health in the Czech Republic

    Directory of Open Access Journals (Sweden)

    J. Řehulka

    2006-01-01

    Full Text Available In the period from 1995 to 2004, the following mycobacterial species were isolated during the examination of the state of health of aquarium fish from the Moravian-Silesian region of the Czech Republic: Mycobacterium fortuitum (Paracheirodon axelrodi, Poecilia sphenops, Hemigrammus rhodostomus, Hyphessobrycon flammeus, M. chelonae (P. axelrodi, Betta splendens, Xiphophorus helleri, Puntius tetrazona, M. kansasii (P. axelrodi, B. splendens, M. simiae (Hyphessobrycon ecuadoriensis, and M. gordonae (P. axelrodi, Colisa lalia, B. splendens, Symphysodon discus. The first isolation from aquarium fish was recorded in the case of M. kansasii and the second isolation in the case of M. simiae; both should also be taken into account as aetiological agents of mycobacterial infections in humans. The measures to reduce mycobacterial infections in both fish and humans should include monitoring water mains as possible sources of M. kansasii infections, compliance with the sanitation principles in handling fish suspected of being infected and the content of tanks (molluscs, water, plants, and the introduction of strict veterinary inspection of imported fish, fish from aquarist shops and from large-scale distributors.

  1. Causal and causally separable processes

    Science.gov (United States)

    Oreshkov, Ognyan; Giarmatzi, Christina

    2016-09-01

    The idea that events are equipped with a partial causal order is central to our understanding of physics in the tested regimes: given two pointlike events A and B, either A is in the causal past of B, B is in the causal past of A, or A and B are space-like separated. Operationally, the meaning of these order relations corresponds to constraints on the possible correlations between experiments performed in the vicinities of the respective events: if A is in the causal past of B, an experimenter at A could signal to an experimenter at B but not the other way around, while if A and B are space-like separated, no signaling is possible in either direction. In the context of a concrete physical theory, the correlations compatible with a given causal configuration may obey further constraints. For instance, space-like correlations in quantum mechanics arise from local measurements on joint quantum states, while time-like correlations are established via quantum channels. Similarly to other variables, however, the causal order of a set of events could be random, and little is understood about the constraints that causality implies in this case. A main difficulty concerns the fact that the order of events can now generally depend on the operations performed at the locations of these events, since, for instance, an operation at A could influence the order in which B and C occur in A’s future. So far, no formal theory of causality compatible with such dynamical causal order has been developed. Apart from being of fundamental interest in the context of inferring causal relations, such a theory is imperative for understanding recent suggestions that the causal order of events in quantum mechanics can be indefinite. Here, we develop such a theory in the general multipartite case. Starting from a background-independent definition of causality, we derive an iteratively formulated canonical decomposition of multipartite causal correlations. For a fixed number of settings and

  2. Causal mapping

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2006-01-01

    The lecture note explains how to use the causal mapping method as well as the theoretical framework aoosciated to the method......The lecture note explains how to use the causal mapping method as well as the theoretical framework aoosciated to the method...

  3. General properties of grapevine viruses occurring in Hungary

    Directory of Open Access Journals (Sweden)

    Eszter Cseh

    2012-03-01

    Full Text Available The past fifty years important advances have been made in the field of grapevine virus research, including characterization of pathogens and control measurements. Still the occurrence of Grapevine fanleaf virus (GFLV, Arabis mosaic virus (ArMV, Tomato black ring virus (TBRV, Grapevine chrome mosaic virus (GCMV, Alfalfa mosaic virus (AMV, Grapevine Bulgarian latent virus (GBLV, Grapevine fleck virus (GFkV, Grapevine leafroll- associated viruses (GLRaV1-4, Grapevine virus A (GVA, Grapevine virus B (GVB and Grapevine rupestris stem pitting- associated virus (GRSPaV have been reported in Hungary and characterized by conventional methods as woody indexing, herbaceous indexing and serological methods. Among grapevine viruses the Grapevine line pattern virus (GLPV seems to be uncial; because it was reported only in Hungary. Causal agents of several grapevine diseases, like enation, vein necrosis and vein mosaic remained undiscovered. These virus-like diseases occurred only sporadically, without economic importance.

  4. Partial characterization of bacteriocin-like compounds from two strains of Bacillus cereus with biological activity against Paenibacillus larvae, the causal agent of American Foulbrood disease.

    Science.gov (United States)

    Minnaard, J; Alippi, A M

    2016-12-01

    American Foulbrood (AFB), caused by the spore-forming Gram-positive bacterium Paenibacillus larvae, is the most severe bacterial disease affecting honeybees worldwide. Two bacterial isolates showing specific inhibitory activity against P. larvae were identified as Bacillus cereus by 16S rDNA sequencing. Antagonistic compounds were obtained from cell-free supernatants of strains m6c and m387 growing on Trypticase Soy Broth and concentrated by NH4 SO4 precipitation, ultrafiltration and butanol extraction. Both compounds were characterized as bacteriocin-like inhibitory substances (BLIS). BLISm6c and BLISm387 were stable at 70°C for 30 min and active in the pH range from 3 to 7. The antibacterial activity was completely lost at pH values higher than 8 or temperatures >80°C. Both BLIS have a narrow activity range and highly inhibit the growth of P. larvae. BLISm6c and BLISm387 differ from each other and other BLIS reportedly produced by B. cereus with regard to their molecular weights, antibacterial activity, minimal inhibitory concentration values and sensitivity to degradative enzymes. The findings of this study suggest that BLISm6c and BLISm387 can potentially be used to control AFB. An Integrated Pest Management (IPM) approach is needed to ensure the sustainability of the beekeeping industry due to the increasing demand for organic honey and the reduction of dependence on antibiotics. Biocontrol agents produced by bacteria isolated from apiarian sources seem promising and able to combine with an IPM strategy. The most significant findings of this study are the characterization of bacteriocin-like compounds (BLIS) obtained from two strains of Bacillus cereus isolated from honey. Both BLIS have a narrow activity range and highly inhibit the growth of Paenibacillus larvae, the causal agent of American Foulbrood disease of honey bees. © 2016 The Society for Applied Microbiology.

  5. Transmission of Pantoea ananatis and P. agglomerans, causal agents of center rot of onion (Allium cepa), by onion thrips (Thrips tabaci) through feces.

    Science.gov (United States)

    Dutta, B; Barman, A K; Srinivasan, R; Avci, U; Ullman, D E; Langston, D B; Gitaitis, R D

    2014-08-01

    Frankliniella fusca, the tobacco thrips, has been shown to acquire and transmit Pantoea ananatis, one of the causal agents of the center rot of onion. Although Thrips tabaci, the onion thrips, is a common pest of onions, its role as a vector of P. ananatis has been unknown. The bacterium, P. agglomerans, is also associated with the center rot of onion, but its transmission by thrips has not been previously investigated. In this study, we investigated the relationship of T. tabaci with P. ananatis and P. agglomerans. Surface-sterilized T. tabaci were provided with various acquisition access periods (AAP) on onion leaves inoculated with either P. ananatis or P. agglomerans. A positive exponential relationship was observed between thrips AAP duration and P. ananatis (R² = 0.967; P = 0.023) or P. agglomerans acquisition (R² = 0.958; P = 0.017). Transmission experiments conducted with T. tabaci adults indicated that 70% of the seedlings developed center rot symptoms 15 days after inoculation. Immunofluorescence microscopy with antibodies specific to P. ananatis revealed that the bacterium was localized only in the gut of T. tabaci adults. Mechanical inoculation of onion seedlings with fecal rinsates alone produced center rot but not with salivary secretions. Together these results suggested that T. tabaci could efficiently transmit P. ananatis and P. agglomerans.

  6. Multiple locus VNTR analysis highlights that geographical clustering and distribution of Dichelobacter nodosus, the causal agent of footrot in sheep, correlates with inter-country movements.

    Science.gov (United States)

    Russell, Claire L; Smith, Edward M; Calvo-Bado, Leonides A; Green, Laura E; Wellington, Elizabeth M H; Medley, Graham F; Moore, Lynda J; Grogono-Thomas, Rosemary

    2014-03-01

    Dichelobacter nodosus is a Gram-negative, anaerobic bacterium and the causal agent of footrot in sheep. Multiple locus variable number tandem repeat (VNTR) analysis (MLVA) is a portable technique that involves the identification and enumeration of polymorphic tandem repeats across the genome. The aims of this study were to develop an MLVA scheme for D. nodosus suitable for use as a molecular typing tool, and to apply it to a global collection of isolates. Seventy-seven isolates selected from regions with a long history of footrot (GB, Australia) and regions where footrot has recently been reported (India, Scandinavia), were characterised. From an initial 61 potential VNTR regions, four loci were identified as usable and in combination had the attributes required of a typing method for use in bacterial epidemiology: high discriminatory power (D>0.95), typeability and reproducibility. Results from the analysis indicate that D. nodosus appears to have evolved via recombinational exchanges and clonal diversification. This has resulted in some clonal complexes that contain isolates from multiple countries and continents; and others that contain isolates from a single geographic location (country or region). The distribution of alleles between countries matches historical accounts of sheep movements, suggesting that the MLVA technique is sufficiently specific and sensitive for an epidemiological investigation of the global distribution of D. nodosus. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Post-transcriptional silencing of the SGE1 gene induced by a dsRNA hairpin in Fusarium oxysporum f. sp cubense, the causal agent of Panama disease.

    Science.gov (United States)

    Fernandes, J S; Angelo, P C S; Cruz, J C; Santos, J M M; Sousa, N R; Silva, G F

    2016-04-04

    Fusarium oxysporum f. sp cubense (Foc), the causal agent of Panama disease, is responsible for economic losses in banana crops worldwide. The identification of genes that effectively act on pathogenicity and/or virulence may contribute to the development of different strategies for disease control and the production of resistant plants. The objective of the current study was to analyze the importance of SGE1 gene expression in Foc virulence through post-transcriptional silencing using a double-stranded RNA hairpin. Thirteen transformants were selected based on different morphological characteristics, and sporulation in these transformants was significantly reduced by approximately 95% (P < 0.05) compared to that of the wild-type strain. The relative SGE1 expression levels in the transformant strains were reduced by 27 to 47% compared to those in the wild-type strain. A pathogenicity analysis revealed that the transformants were able to reach the rhizomes and pseudostems of the inoculated banana plants. However, the transformants induced initial disease symptoms in the banana plants approximately 10 days later than that by the wild-type Foc, and initial disease symptoms persisted even at 45 days after inoculation. These results indicate that the SGE1 gene is directly involved in the virulence of Foc. Therefore, SGE1 may be a potential candidate for host-induced gene silencing in banana plants.

  8. Genetic and morphological evidence that Phoma sclerotioides, causal agent of brown root rot of alfalfa, is composed of a species complex.

    Science.gov (United States)

    Wunsch, Michael J; Bergstrom, Gary C

    2011-05-01

    Phoma sclerotioides, causal agent of brown root rot of alfalfa, causes severe root and crown lesions on alfalfa and other perennial forage legumes in regions with harsh winters. Isolates of P. sclerotioides exhibit diverse cultural morphologies on potato dextrose agar (PDA), suggesting that they may exhibit a high degree of genetic diversity. To investigate the genetic relatedness of P. sclerotioides isolates, 154 isolates from North America were sequenced at 10 loci. Maximum parsimony and maximum likelihood analyses of the complete 10-locus data set placed isolates into multiple strongly supported clades, and analyses of gene-jackknife and single-gene partitions of the data set indicated robust support for six major clades and three subclades. Genetic differences corresponded closely to differences in conidial size and septation, pycnidial neck length, mycelial pigmentation, and growth rate in axenic culture at 18 and 25°C. Isolates exhibited morphologies broadly consistent with the species description of P. sclerotioides, and new species were not designated. On the basis of genetic and morphological differences, we propose establishing seven infraspecific varieties within P. sclerotioides: P. sclerotioides var. sclerotioides, champlainii, viridis, obscurus, steubenii, macrospora, and saskatchewanii. All varieties of P. sclerotioides caused brown root rot of alfalfa and grew well at low temperatures.

  9. In vitro antibacterial effect of exotic plants essential oils on the honeybee pathogen Paenibacillus larvae, causal agent of American foul brood

    Energy Technology Data Exchange (ETDEWEB)

    Fuselli, S. R.; Garcia de la Rosa, S. B.; Eguaras, M. J.; Fritz, R.

    2010-07-01

    Chemical composition and antimicrobial activity of exotic plants essential oils to potentially control Paenibacillus larvae, the causal agent of American foul brood disease (AFB) were determined. AFB represents one of the main plagues that affect the colonies of honeybees Apis mellifera L. with high negative impact on beekeepers worldwide. Essential oils tested were niaouli (Melaleuca viridiflora) and tea tree (Melaleuca alternifolia) from Myrtaceae, and citronella grass (Cymbopogon nardus) and palmarosa (Cymbopogon martinii) from Gramineae. The components of the essential oils were identified by SPME-GC/MS analysis. The antimicrobial activity of the oils against P. larvae was determined by the broth micro dilution method. In vitro assays of M. viridiflora and C. nardus oils showed the inhibition of the bacterial strains at the lowest concentrations tested, with minimal inhibitory concentration (MIC) mean value about 320 mg L{sup -}1 for both oils, respectively. This property could be attributed to the kind and percentage of the components of the oils. Terpinen-4-ol (29.09%), {alpha}-pinene (21.63%) and limonene (17.4%) were predominant in M. viridiflora, while limonene (24.74%), citronelal (24.61%) and geraniol (15.79%) were the bulk of C. nardus. The use of these essential oils contributes to the screening of alternative natural compounds to control AFB in the apiaries; toxicological risks and other undesirable effects would be avoided as resistance factors, developed by the indiscriminate use of antibiotics. (Author) 40 refs.

  10. Variable number of tandem repeat markers in the genome sequence of Mycosphaerella fijiensis, the causal agent of black leaf streak disease of banana (Musa spp).

    Science.gov (United States)

    Garcia, S A L; Van der Lee, T A J; Ferreira, C F; Te Lintel Hekkert, B; Zapater, M-F; Goodwin, S B; Guzmán, M; Kema, G H J; Souza, M T

    2010-11-09

    We searched the genome of Mycosphaerella fijiensis for molecular markers that would allow population genetics analysis of this plant pathogen. M. fijiensis, the causal agent of banana leaf streak disease, also known as black Sigatoka, is the most devastating pathogen attacking bananas (Musa spp). Recently, the entire genome sequence of M. fijiensis became available. We screened this database for VNTR markers. Forty-two primer pairs were selected for validation, based on repeat type and length and the number of repeat units. Five VNTR markers showing multiple alleles were validated with a reference set of isolates from different parts of the world and a population from a banana plantation in Costa Rica. Polymorphism information content values varied from 0.6414 to 0.7544 for the reference set and from 0.0400 and 0.7373 for the population set. Eighty percent of the polymorphism information content values were above 0.60, indicating that the markers are highly informative. These markers allowed robust scoring of agarose gels and proved to be useful for variability and population genetics studies. In conclusion, the strategy we developed to identify and validate VNTR markers is an efficient means to incorporate markers that can be used for fungicide resistance management and to develop breeding strategies to control banana black leaf streak disease. This is the first report of VNTR-minisatellites from the M. fijiensis genome sequence.

  11. Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES

    Directory of Open Access Journals (Sweden)

    Gaspar PENICHE-LARA

    2015-04-01

    Full Text Available Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study’s results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

  12. In vitro Antagonistic Mechanisms of Trichoderma spp. and Talaromyces flavus to Control Gaeumannomyces graminis var. tritici the Causal Agent of Wheat Take-all Disease

    Directory of Open Access Journals (Sweden)

    Seddighe Mohammadi

    2015-08-01

    Full Text Available Wheat take-all disease caused by Gaeumannomyces graminis var. tritici has recently been detected in different regions of Iran. With respect to biocontrol effect of Trichoderma spp. on many pathogenic fungi, seven isolates of Trichoderma and four isolates of Talaromyces were in vitro evaluated in terms of their biological control against the disease causal agent. In dual culture test the five isolates showed efficient competition for colonization against pathogenic fungus and the highest percentages of inhibition belonging to Talaromyces flavus 60 and Talaromyces flavus 136 were 59.52 and 57.61%, respectively. Microscopic investigations showed that in regions where antagonistic isolates and Gaeumannomyces graminis var. tritici coincide, hyphal contact, penetration and fragmentation of Gaeumannomyces graminis var. tritici were observed. Investigating the effect of volatile and non-volatile compounds at 10 ml concentration showed that the highest inhibition percentage on mycelium growth of the pathogen caused by T. harzianum (44.76% and T. longibrachiatum (52.38% respectively.

  13. Inactivation of West Nile Virus in Serum with Heat, Ionic Detergent, and Reducing Agent for Proteomic Applications

    Science.gov (United States)

    2017-06-14

    Inactivation of West Nile virus in serum with heat, ionic detergent, and reducing agent for proteomic applications Louis A. Altamura1§, Lisa H...Infectious Diseases, Fort Detrick, MD 21702 3DOD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced...of West Nile virus in serum with heat, detergent, and reducing agent for proteomic applications Abstract Research involving biosafety level 3

  14. Impact of the novel hepatotropic viruslike agent NV-F during chronic hepatitis C virus infection.

    Science.gov (United States)

    Yeh, Chau-Ting; Hsu, Chao-Wei; Chang, Ming-Ling; Tsao, Mei-Ling

    2008-12-15

    NV-F is a novel hepatotropic viruslike agent. To investigate the impact of the NV-F agent during chronic hepatitis C virus (HCV) infection, 101 consecutive patients with chronic HCV infection were evaluated. NV-F DNA in serum samples and NV-F antigen expression in liver tissues were assessed. All patients subsequently received a 6-month course of interferon-based antiviral therapy. Of the 101 patients, 30 (29.7%) were positive for serum NV-F DNA. Immunohistochemical analysis revealed positive NV-F antigen expression in the liver in 14 of these 30 patients. Patients positive for serum NV-F DNA had significantly higher serum aminotransferase levels (P F DNA. In conclusion, coinfection of the NV-F agent in chronic HCV infection is associated with more severe hepatitis activity.

  15. Causal Reconstruction

    Science.gov (United States)

    1993-02-01

    suitable source of core events supporting causal reconstruction in a range of domains might be a combination of bodily - kinesthetic and simple...suggested in the previ- ous section, a good place to start might be with causal situations involving bodily - kinesthetic events or simple mechanical events...ANIZATION NAME(S) AND ADDRESS(LS) tý PJIfORMIN’, CRGANIZATION !.LPDRT NUMBEK Artificial Intelligence Laboratory 545 Technology Square AIM 1403 Cambridge

  16. Detection and partial molecular characterization of Grapevine fleck virus, Grapevine virus D, Grapevine leafroll-associated virus -5 and -6 infecting grapevines in Brazil.

    OpenAIRE

    Fajardo,Thor Vinícius Martins; Eiras,Marcelo; Nickel,Osmar; Dubiela,Carla Rosa; Souto,Eliezer Rodrigues de

    2012-01-01

    Grapevine fleck, rugose wood and leafroll are three grapevine viral diseases whose causal agents (or associated viruses) respectively are Grapevine fleck virus (GFkV), Grapevine virus D (GVD) and Grapevine leafroll-associated virus 5 and 6 (GLRaV-5 and -6). The objective of this work was to perform a partial molecular characterization of local isolates of these four viral species that infect grapevines. The nucleotide and deduced amino acid sequences of complete genes of the coat protein (CP)...

  17. Genetically Engineered Vaccinia Viruses As Agents for Cancer Treatment, Imaging, and Transgene Delivery

    Directory of Open Access Journals (Sweden)

    Dana Haddad

    2017-05-01

    Full Text Available Despite advances in technology, the formidable challenge of treating cancer, especially if advanced, still remains with no significant improvement in survival rates, even with the most common forms of cancer. Oncolytic viral therapies have shown great promise for the treatment of various cancers, with the possible advantages of stronger treatment efficacy compared to conventional therapy due to higher tumor selectivity, and less toxicity. They are able to preferentially and selectively propagate in cancer cells, consequently destroying tumor tissue mainly via cell lysis, while leaving non-cancerous tissues unharmed. Several wild-type and genetically engineered vaccinia virus (VACV strains have been tested in both preclinical and clinical trials with promising results. Greater understanding and advancements in molecular biology have enabled the generation of genetically engineered oncolytic viruses for safer and more efficacious treatment, including arming VACVs with cytokines and immunostimulatory molecules, anti-angiogenic agents, and enzyme prodrug therapy, in addition to combining VACVs with conventional external and systemic radiotherapy, chemotherapy, immunotherapy, and other virus strains. Furthermore, novel oncolytic vaccinia virus strains have been generated that express reporter genes for the tracking and imaging of viral therapy and monitoring of therapeutic response. Further study is needed to unlock VACVs’ full potential as part of the future of cancer therapy.

  18. Genetically Engineered Vaccinia Viruses As Agents for Cancer Treatment, Imaging, and Transgene Delivery

    Science.gov (United States)

    Haddad, Dana

    2017-01-01

    Despite advances in technology, the formidable challenge of treating cancer, especially if advanced, still remains with no significant improvement in survival rates, even with the most common forms of cancer. Oncolytic viral therapies have shown great promise for the treatment of various cancers, with the possible advantages of stronger treatment efficacy compared to conventional therapy due to higher tumor selectivity, and less toxicity. They are able to preferentially and selectively propagate in cancer cells, consequently destroying tumor tissue mainly via cell lysis, while leaving non-cancerous tissues unharmed. Several wild-type and genetically engineered vaccinia virus (VACV) strains have been tested in both preclinical and clinical trials with promising results. Greater understanding and advancements in molecular biology have enabled the generation of genetically engineered oncolytic viruses for safer and more efficacious treatment, including arming VACVs with cytokines and immunostimulatory molecules, anti-angiogenic agents, and enzyme prodrug therapy, in addition to combining VACVs with conventional external and systemic radiotherapy, chemotherapy, immunotherapy, and other virus strains. Furthermore, novel oncolytic vaccinia virus strains have been generated that express reporter genes for the tracking and imaging of viral therapy and monitoring of therapeutic response. Further study is needed to unlock VACVs’ full potential as part of the future of cancer therapy. PMID:28589082

  19. Uneven distribution of mating type alleles in Iranian populations of Cercospora beticola, the causal agent of Cercospora leaf spot disease of sugar beet

    Directory of Open Access Journals (Sweden)

    Mounes BAKHSHI

    2011-05-01

    Full Text Available Normal 0 14 false false false IT ZH-TW X-NONE MicrosoftInternetExplorer4 Cercospora beticola, the causal agent of Cercospora leaf spot disease on sugar beet, is thought to be exclusively asexual because no teleomorph has yet been found. The possibility of a clandestine sexual cycle in the Iranian population of Cercospora beticola was evaluated by analyzing the distribution and frequency of the mating type alleles on a microspatial and a macrogeographical scale. A total of 89 single-conidial Cercospora beticola isolates were obtained from sugar beet fields in the Moghan, the Talesh and the Khoy regions. The isolates were identifed using a Cercospora beticola-specifc primer set in a PCR assay. A multiplex PCR method using previously designed mating type primers was used to study the distribution and the frequency of the mating type alleles. All isolates showed either the 805-bp fragment or the 442-bp fragment of the MAT1-1 and MAT1-2 genes, but no isolate had both fragments. The distribution of the mating type genes in the sampled areas was uneven. From three sugar beet fields sampled in the Moghan region, two fields had only MAT1-1 isolates; while in the third field all isolates had only the MAT1-2 allele. In the Talesh region only MAT1-1 isolates occurred, and in the Khoy region the mating type alleles were uniformly distributed amongst the isolates. The skewed distribution of mating type alleles in Northwestern Iran was in line with the lack of a sexual cycle for this species and may also indicate that sugar fields in the Moghan region were infected by C. beticola populations of different origins. Normal 0 false false false EN-US X-NONE FA

  20. Comparison of cultural growth and in planta quantification of Didymella pinodes, Phoma koolunga and Phoma medicaginis var. pinodella, causal agents of ascochyta blight on field pea (Pisum sativum).

    Science.gov (United States)

    Davidson, J A; Krysinska-Kaczmarek, M; A McKay, Herdina; Scott, E S

    2012-01-01

    The causal agents of ascochyta blight on field pea in South Australia, Didymella pinodes, Phoma medicaginis var. pinodella and Phoma koolunga, are isolated from a single plant within a crop, suggesting competition for space and nutrients. Interactions among these pathogens were investigated. Diameters of colonies of D. pinodes and of P. medicaginis var. pinodella were significantly reduced on PDA amended with filtrate from broth cultures of P. koolunga as were diameters of colonies of D. pinodes on PDA amended with filtrate from P. medicaginis var. pinodella or D. pinodes. This effect was negated when cultures were transferred to unamended PDA, indicating filtrates were fungistatic instead of fungicidal. The diameter of P. koolunga colonies was not influenced by filtrate from any of the three species. When pathogens were co-inoculated in pairs onto leaves on field pea plants, the quantity of DNA of D. pinodes and of P. medicaginis var. pinodella was significantly reduced if co-inoculated with P. koolunga. The quantity of DNA of P. koolunga was not influenced by co-inoculation. When co-inoculated onto excised leaf disks on sterile water the mean lesion diameter due to D. pinodes and to P. medicaginis var. pinodella was significantly reduced if co-inoculated with P. koolunga isolate DAR78535. Lesions caused by D. pinodes were significantly reduced when inoculum was self-paired. Conversely the diameter of lesions caused by P. koolunga DAR78535 increased when self-paired or when co-inoculated with P. medicaginis var. pinodella. Unlike leaf disks on sterile water, co-inoculation had no influence on lesion size or quantity of pathogen DNA in leaf disks on water agar. Antagonism, including self-antagonism, was detected among these species, leading to reduction in lesion size and quantity of pathogen DNA. The slower growing species, P. koolunga, was not self-antagonistic, and in a few instances the effect of co-inoculation was additive or synergistic.

  1. Protective effect of Polygonum orientale L. extracts against Clavibater michiganense subsp. sepedonicum, the causal agent of bacterial ring rot of potato.

    Directory of Open Access Journals (Sweden)

    Jin Cai

    Full Text Available The Polygonum orientale L. extracts were investigated for antibacterial activity against Clavibater michiganense subsp. sepedonicum (Spieckermann & Kotthoff Davis et al., the causal agent of a serious disease called bacterial ring rot of potato. The results showed that the leaf extracts of P. orientale had significantly (p<0.05 greater antibacterial activity against C. michiganense subsp. sepedonicum than root, stem, flower extracts in vitro. According to the results of single factor experiments and L(273(13 orthogonal experiments, optimum extraction conditions were A1B3C1, extraction time 6 h, temperature 80°C, solid to liquid ratio 1∶10 (g:mL. The highest (p<0.05 antibacterial activity was observed when pH was 5, excluding the effect of control. The extracts were stable under ultraviolet (UV. In vivo analysis revealed that 50 mg/mL of P. orientale leaf extracts was effective in controlling decay. Under field conditions, 50 mg/mL of P. orientale leaf extracts also improved growth parameters (whole plant length, shoot length, root length, plant fresh weight, shoot fresh weight, root fresh weight, dry weight, and number of leaves, in the 2010 and 2011 two growing seasons. Further solvent partition assays showed that the most active compounds were in the petroleum ether fractionation. Transmission electron microscopy (TEM showed drastic ultrastructural changes caused by petroleum ether fractionation, including bacterial deformation, electron-dense particles, formation of vacuoles and lack of cytoplasmic materials. These results indicated that P. orientale extracts have strong antibacterial activity against C. michiganense subsp. sepedonicum and a promising effect in control of bacterial ring rot of potato disease.

  2. Epidemiological causality.

    Science.gov (United States)

    Morabia, Alfredo

    2005-01-01

    Epidemiological methods, which combine population thinking and group comparisons, can primarily identify causes of disease in populations. There is therefore a tension between our intuitive notion of a cause, which we want to be deterministic and invariant at the individual level, and the epidemiological notion of causes, which are invariant only at the population level. Epidemiologists have given heretofore a pragmatic solution to this tension. Causal inference in epidemiology consists in checking the logical coherence of a causality statement and determining whether what has been found grossly contradicts what we think we already know: how strong is the association? Is there a dose-response relationship? Does the cause precede the effect? Is the effect biologically plausible? Etc. This approach to causal inference can be traced back to the English philosophers David Hume and John Stuart Mill. On the other hand, the mode of establishing causality, devised by Jakob Henle and Robert Koch, which has been fruitful in bacteriology, requires that in every instance the effect invariably follows the cause (e.g., inoculation of Koch bacillus and tuberculosis). This is incompatible with epidemiological causality which has to deal with probabilistic effects (e.g., smoking and lung cancer), and is therefore invariant only for the population.

  3. Identification and Characterisation of New Microbial Antagonists for Biocontrol of Monilinia laxa, the Causal Agent of Brown Rot on Stone Fruit

    Directory of Open Access Journals (Sweden)

    Peter Jeffries

    2013-10-01

    Full Text Available Monilinia laxa is the causal agent of brown rot disease on stone fruits, and also causes blossom wilt and twig canker. The common practice used to manage this disease is through fungicide treatments. However the demand to reduce fungicide inputs has been increasing and there is a growing number of reports of M. laxa strains that are resistant to fungicides. There is an urgent need to search for an alternative strategy to control the disease. This study focused on the isolation and characterisation of biological control agents (BCAs using indigenous isolates isolated from cherries and plums collected within the UK. A total of 192 isolates were screened against two strains of M. laxa in a series of in vitro dual culture tests. From this in vitro screen, 12 isolates were selected for a subsequent in vivo screen on detached fruits, which then narrowed these isolates down to two potential BCAs. These two strains were identified as Bacillus amyloliquefaciens/subtilis (isolate B91 and Aureobasidium pullulans (isolate Y126. The capability of these two potential BCAs to grow and survive at a range of temperatures likely to be experienced under field and storage conditions was studied in order to gain knowledge for product formulation and field application. Bacillus sp. B91 was shown to be a mesophilic bacterium that could grow at 10–25 °C but suffered significant mortality at 0 and 5 °C, while A. pullulans Y126 was both mesophilic and psychrotolerant as it grew between 0–25 °C with the optimum at 20 °C. When all nutrients were removed, Y126 was able to survive for several weeks in all test temperatures (0–25 °C but showed significant mortality at 25 °C. The capability of B91 to survive at 20 and 25 °C was higher than at low temperatures (0–15 °C. In addition, the modes of action of the potential BCAs were studied. B91 was shown to produce soluble and volatile organic compounds that inhibited M. laxa, while A. pullulans Y126 did not

  4. Monkeypox Virus Infections in Small Animal Models for Evaluation of Anti-Poxvirus Agents

    Directory of Open Access Journals (Sweden)

    Inger K. Damon

    2010-12-01

    Full Text Available An ideal animal model for the study of a human disease is one which utilizes a route of infection that mimics the natural transmission of the pathogen; the ability to obtain disease with an infectious dose equivalent to that causing disease in humans; as well having a disease course, morbidity and mortality similar to that seen with human disease. Additionally, the animal model should have a mode(s of transmission that mimics human cases. The development of small animal models for the study of monkeypox virus (MPXV has been quite extensive for the relatively short period of time this pathogen has been known, although only a few of these models have been used to study anti-poxvirus agents. We will review those MPXV small animal models that have been developed thus far for the study of therapeutic agents.

  5. Recent characterization of cowpea aphid-borne mosaic virus ...

    African Journals Online (AJOL)

    Woodiness disease is the most important disorder of passion fruit worldwide. The causal agent in Brazil is the Cowpea aphid-borne mosaic virus (CABMV), and despite the economic relevance of passion fruit for agriculture there have been recently very few studies about this virus in Brazil and worldwide. This work reveals ...

  6. Zika virus infection, associated microcephaly, and low yellow fever vaccination coverage in Brazil: is there any causal link?

    Science.gov (United States)

    De Góes Cavalcanti, Luciano Pamplona; Tauil, Pedro Luiz; Alencar, Carlos Henrique; Oliveira, Wanderson; Teixeira, Mauro Martins; Heukelbach, Jorg

    2016-06-30

    Since the end of 2014, Zika virus (ZIKV) infection has been rapidly spreading in Brazil. To analyze the possible association of yellow fever vaccine with a protective effect against ZIKV-related microcephaly, the following spatial analyses were performed, using Brazilian municipalities as units: i) yellow fever vaccination coverage in Brazilian municipalities in individuals aged 15-49; ii) reported cases of microcephaly by municipality; and iii) confirmed cases of microcephaly related to ZIKV, by municipality. SaTScan software was used to identify clusters of municipalities for high risk of microcephaly. There were seven significant high risk clusters of confirmed microcephaly cases, with four of them located in the Northeast where yellow fever vaccination rates were the lowest. The clusters harbored only 2.9% of the total population of Brazil, but 15.2% of confirmed cases of microcephaly. We hypothesize that pregnant women in regions with high yellow fever vaccination coverage may pose their offspring to lower risk for development of microcephaly. There is an urgent need for systematic studies to confirm the possible link between low yellow fever vaccination coverage, Zika virus infection and microcephaly.

  7. First discovery of acetone extract from cottonseed oil sludge as a novel antiviral agent against plant viruses.

    Science.gov (United States)

    Zhao, Lei; Feng, Chaohong; Hou, Caiting; Hu, Lingyun; Wang, Qiaochun; Wu, Yunfeng

    2015-01-01

    A novel acetone extract from cottonseed oil sludge was firstly discovered against plant viruses including Tobacco mosaic virus (TMV), Rice stripe virus (RSV) and Southern rice black streaked dwarf virus (SRBSDV). Gossypol and β-sitosterol separated from the acetone extract were tested for their effects on anti-TMV and analysed by nuclear magnetic resonance (NMR) assay. In vivo and field trials in different geographic distributions and different host varieties declared that this extract mixture was more efficient than the commercial agent Ningnanmycin with a broad spectrum of anti-plant-viruses activity. No phytotoxic activity was observed in the treated plants and environmental toxicology showed that this new acetone extract was environmentally friendly, indicating that this acetone extract has potential application in the control of plant virus in the future.

  8. Use of Aptamers as Diagnostics Tools and Antiviral Agents for Human Viruses

    Directory of Open Access Journals (Sweden)

    Víctor M. González

    2016-12-01

    Full Text Available Appropriate diagnosis is the key factor for treatment of viral diseases. Time is the most important factor in rapidly developing and epidemiologically dangerous diseases, such as influenza, Ebola and SARS. Chronic viral diseases such as HIV-1 or HCV are asymptomatic or oligosymptomatic and the therapeutic success mainly depends on early detection of the infective agent. Over the last years, aptamer technology has been used in a wide range of diagnostic and therapeutic applications and, concretely, several strategies are currently being explored using aptamers against virus proteins. From a diagnostics point of view, aptamers are being designed as a bio-recognition element in diagnostic systems to detect viral proteins either in the blood (serum or plasma or into infected cells. Another potential use of aptamers is for therapeutics of viral infections, interfering in the interaction between the virus and the host using aptamers targeting host-cell matrix receptors, or attacking the virus intracellularly, targeting proteins implicated in the viral replication cycle. In this paper, we review how aptamers working against viral proteins are discovered, with a focus on recent advances that improve the aptamers’ properties as a real tool for viral infection detection and treatment.

  9. Extrato etanólico de Senna alata no controle de Myrothecium roridum, agente casual do cancro-de-mirotécio Ethanolic extract of Senna alata in the control of Myrothecium roridum, causal agent of myrothecium leaf spot

    Directory of Open Access Journals (Sweden)

    E.V Medeiros

    2011-09-01

    Full Text Available O fungo M. roridum é o causador da doença cancro-de-mirotécio em meloeiro e vem provocando grandes perdas na produção dessa olerícola. É uma doença de difícil controle, em razão de seu agente ser habitante do solo. Devido à procura de formas alternativas de controle, o objetivo deste trabalho foi avaliar a atividade dos extratos etanólicos de partes de S. alata sobre M. roridum. O delineamento experimental foi inteiramente casualizado, distribuído em esquema fatorial 4 x 6 + 1, sendo o primeiro fator partes da planta (caule, inflorescência, raiz e vagem e o segundo, seis concentrações (0,25; 0,50; 50; 75; 250; e 500 µg mL-1 mais a testemunha, com quatro repetições por tratamento. As variáveis avaliadas foram: taxa de crescimento micelial (TCM, inibição do crescimento micelial (ICM e área abaixo da curva do crescimento micelial (AACCM. Todos os extratos de partes vegetais de S. alata foram eficientes em inibir o crescimento micelial de M. roridum. O extrato etanólico da vagem foi o que melhor inibiu o crescimento de M. roridum, na concentração de 500 µg mL-1 , seguido do extrato da raiz e do caule.The fungus M. roridum is the causal agent of the myrothecium Leaf Spot disease in melon, being responsible for great losses in the production of this olericulture. This disease is difficult to control, since its agent inhabits the soil. Seeking for alternative forms of control, this work aimed to evaluate the effect of the activity of ethanolic extracts of parts of S. alata on M. roridum. The experimental design was completely randomized and distributed in a factorial scheme 4 x 6 + 1, with the first factor being parts of the plant (stalk, flower, root and green bean, and the second factor, six concentrations (0.25; 0.50, 50, 75, 250 and 500 µg mL-1, plus a control, with four repetitions per treatment. The available variables were: mycelial growth rate (MGR, mycelial growth inhibition (MGI and area below mycelial growth curve

  10. Diversidade fenotípica e patogênica de Colletotrichum, agente causal da antracnose em mangueira, e identificação de espécie

    Directory of Open Access Journals (Sweden)

    I.M.R.S. Serra

    2011-03-01

    Full Text Available O presente trabalho teve como objetivo estudar a diversidade fenotípica e patogênica de 40 isolados de Colletotrichum obtidos de mangueira no Nordeste do Brasil e identificar diferentes espécies desse fitopatógeno, agente causal de antracnose, através da análise da seqüência da região ITS do rDNA. Quanto à caracterização morfológica e cultural, as colônias dos isolados apresentaram diversidade em relação à cor e aspecto, sendo mais comum à cor branco-cinza, característica de Colletotrichum gloeosporioides. Não foram observadas variações expressivas na morfologia dos 40 isolados. Os conídios apresentaram-se, predominantemente, hialinos e unicelulares, com formato variando de bastonete para cilíndrico. Todos os isolados produziram apressórios variados em formato e quantidade e apenas 10 isolados apresentaram setas. Para efeito do crescimento micelial e taxa de crescimento foi possível classificar os isolados em sete grupos. Vinte e dois isolados exibiram taxa de crescimento >10mm/dia, considerada típica da espécie C. gloeosporioides. Os isolados foram patogênicos em folhas destacadas de mangueira, induzindo sintomas de antracnose, na forma de manchas escuras levemente deprimidas, e apresentando variações quanto à agressividade. Na identificação específica, baseada na análise da seqüência ITS do DNA ribossomal, 36 isolados amplificaram com o oligonucleotídeos CgInt, específico para C. gloeosporioides e o ITS4, Os isolados CM1, CM4, CM5 e CM10, não amplificaram produtos para nenhum dos oligonucleotídeos específicos, sendo identificados como Colletotrichum spp. Os resultados desse trabalho demonstraram que isolados de Colletotrichum, obtidos de mangueira, apresentam ampla variabilidade morfofisiológica e patogênica. E que, possivelmente, existe mais de uma espécie de Colletotrichum que causa antracnose em mangueira no Nordeste do Brasil.

  11. Optimization of an In Situ Cellular ELISA Performed on Influenza A Virus-Infected Monolayers for Screening of Antiviral Agents

    Science.gov (United States)

    1999-02-04

    the specific conditions necessary for susceptibility testing of influenza A virus to antiviral agents such as amount of inoculum size. duration of... conditions of in situ Maintenance media (without fetal bovine cellular ELISA performed on influenza A virus serum) was formulated with 3.0 igml of...obtained the best differ- a new anti-microbial nanoemulsion disinfectant ence between uninfected and infected cells and the (Novavax. Rockville, MD

  12. Evaluation of Nipah Virus as a Human and Animal Biological Terrorism and Warfare Agent

    Science.gov (United States)

    2001-09-01

    Molecular analyses have confirmed that Nipah virus and Hendra virus are closely related, but different viruses . The N, C, P. V, M, F and G genes of Nipah...encephalitis and 106 of them have died. The Nipah virus outbreak also devastated Malaysia’s pig-farming industry. The Nipah virus or so-called Hendra ...Nipah virus belongs to the Paramnyxoviirit strain, which shows similarities to the Hendra virus , which was discovered in Australia in 1994

  13. A Multiplex PCR/LDR Assay for the Simultaneous Identification of Category A Infectious Pathogens: Agents of Viral Hemorrhagic Fever and Variola Virus.

    Directory of Open Access Journals (Sweden)

    Sanchita Das

    Full Text Available CDC designated category A infectious agents pose a major risk to national security and require special action for public health preparedness. They include viruses that cause viral hemorrhagic fever (VHF syndrome as well as variola virus, the agent of smallpox. VHF is characterized by hemorrhage and fever with multi-organ failure leading to high morbidity and mortality. Smallpox, a prior scourge, has been eradicated for decades, making it a particularly serious threat if released nefariously in the essentially non-immune world population. Early detection of the causative agents, and the ability to distinguish them from other pathogens, is essential to contain outbreaks, implement proper control measures, and prevent morbidity and mortality. We have developed a multiplex detection assay that uses several species-specific PCR primers to generate amplicons from multiple pathogens; these are then targeted in a ligase detection reaction (LDR. The resultant fluorescently-labeled ligation products are detected on a universal array enabling simultaneous identification of the pathogens. The assay was evaluated on 32 different isolates associated with VHF (ebolavirus, marburgvirus, Crimean Congo hemorrhagic fever virus, Lassa fever virus, Rift Valley fever virus, Dengue virus, and Yellow fever virus as well as variola virus and vaccinia virus (the agent of smallpox and its vaccine strain, respectively. The assay was able to detect all viruses tested, including 8 sequences representative of different variola virus strains from the CDC repository. It does not cross react with other emerging zoonoses such as monkeypox virus or cowpox virus, or six flaviviruses tested (St. Louis encephalitis virus, Murray Valley encephalitis virus, Powassan virus, Tick-borne encephalitis virus, West Nile virus and Japanese encephalitis virus.

  14. Role of Bacterial Exopolysaccharides as Agents in Counteracting Immune Disorders Induced by Herpes Virus.

    Science.gov (United States)

    Gugliandolo, Concetta; Spanò, Antonio; Maugeri, Teresa L; Poli, Annarita; Arena, Adriana; Nicolaus, Barbara

    2015-08-21

    Extreme marine environments, such as the submarine shallow vents of the Eolian Islands (Italy), offer an almost unexplored source of microorganisms producing unexploited and promising biomolecules for pharmaceutical applications. Thermophilic and thermotolerant bacilli isolated from Eolian vents are able to produce exopolysaccharides (EPSs) with antiviral and immunomodulatory effects against Herpes simplex virus type 2 (HSV-2). HSV-2 is responsible for the most common and continuously increasing viral infections in humans. Due to the appearance of resistance to the available treatments, new biomolecules exhibiting different mechanisms of action could provide novel agents for treating viral infections. The EPSs hinder the HSV-2 replication in human peripheral blood mononuclear cells (PBMC) but not in WISH (Wistar Institute Susan Hayflic) cells line, indicating that cell-mediated immunity was involved in the antiviral activity. High levels of Th1-type cytokines were detected in PBMC treated with all EPSs, while Th2-type cytokines were not induced. These EPSs are water soluble exopolymers able to stimulate the immune response and thus contribute to the antiviral immune defense, acting as immunomodulators. As stimulants of Th1 cell-mediated immunity, they could lead to the development of novel drugs as alternative in the treatment of herpes virus infections, as well as in immunocompromised host.

  15. [Evaluation of the safety of innovative drugs against viruses and infectious agents].

    Science.gov (United States)

    Kobayashi, Tetsu; Yusa, Keisuke; Kawasaki, Nana

    2013-01-01

    Recently, several novel cellular therapy products and biological drugs are being developed to treat various previously untreatable diseases. One of the most important issues regarding these innovations is how to ensure safety over infectious agents, including viruses and prions, in the earliest treatments with these products. The object of this study is a risk assessment of cases of human infectious with the agents and to present a sample risk management plan based on a collaboration among the National Institute of Health Sciences, universities, marketing authorization holders, and scientific societies. There are three subjects of study: (1) the viral safety of cellular therapy products, (2) the viral safety of biological drugs, and (3) the safety of prions. In this report, we describe the objects of the study, the project members, the study plan outline, and the ongoing plans. The results of the viral risk identification and the risk analysis of cellular therapy products will also be described, based on a review of the literature and case reports obtained during the first year of this project.

  16. Distribuição e identificação de Phakopsora pachyrhizi, agente causal da ferrugem da soja no estado de Minas Gerais Identification and distribution of Phakopsora pachyrhizi causal agente of the Asian rust in the Minas Gerais State

    Directory of Open Access Journals (Sweden)

    Patrícia Ferreira Cunha Sousa

    2007-06-01

    guide the planning control measures. The molecular characterization based on PCR has been showing as useful tool to satisfy that need. In this study 86 samples of leaves infected by Phakopsora from the main areas producing soybean in the State of Minas Gerais (Triângulo, Alto Paranaíba, Noroeste, Sudoeste and Sul were used. The extraction of DNA was made by the method of CTAB. For the polimerase chain reaction, specific primers were used for each species, been primer Ppm1/Ppa2 specific for P. pachyrhizi and Ppm1/Pme2 specific for P. meibomiae. The results showed that the 86 samples belonged to the species P. pachyrhizi, agent causal of the "Asian" rust. In other words, there was the production of bands specific from the group primer Ppm1/Ppa2 with approximate size of 141 pairs of bases. These results show that the species Phakopsora present in 100% of the areas analyzed in the State of Minas Gerais was P. pachyrhizi. This information is important to guide futures breeding programs for resistance to the agent of soybean rust in the State.

  17. Inactivation of the novel avian influenza A (H7N9) virus under physical conditions or chemical agents treatment.

    Science.gov (United States)

    Zou, Shumei; Guo, Junfeng; Gao, Rongbao; Dong, Libo; Zhou, Jianfang; Zhang, Ye; Dong, Jie; Bo, Hong; Qin, Kun; Shu, Yuelong

    2013-09-15

    In the spring of 2013, a novel avian-origin influenza A (H7N9) virus in Eastern China emerged causing human infections. Concerns that a new influenza pandemic could occur were raised. The potential effect of chemical agents and physical conditions on inactivation of the novel avian influenza H7N9 virus had not been assessed. To determine the inactivation effectiveness of the novel avian influenza A (H7N9) virus under various physical conditions and chemical treatments, two H7N9 viruses A/Anhui/1/2013 and A/Shanghai/1/2013 were treated by varied temperatures, ultraviolet light, varied pHs and different disinfectants. The viruses with 107.7 EID50 were exposed to physical conditions (temperature, ultraviolet light and pH) or treated with commercial chemical agents (Sodium Hypochlorite, Virkon®-S, and Ethanol) respectively. After these treatments, the viruses were inoculated in SPF embryonated chicken eggs, the allantoic fluid was collected after 72-96 hours culture at 35°C and tested by haemagglutination assay. Both of the tested viruses could tolerate conditions under 56°C for 15 minutes or 60°C for 5 minutes, but their infectivity was completely lost under 56°C for 30 minutes, 65°C for 10 minutes, 70°C, 75°C and 100°C for 1 minute. It was also observed that the H7N9 viruses lost their infectivity totally after exposure of ultraviolet light irradiation for 30 minutes or longer time. Additionally, the viruses were completely inactivated at pH less than 2 for 0.5 hour or pH 3 for 24 hours, however, viruses remained infectious under pH treatment of 4-12 for 24 hours. The viruses were totally disinfected when treated with Sodium Hypochlorite, Virkon®-S and Ethanol at recommended concentrations after only 5 minutes. The novel avian influenza A (H7N9) virus can be inactivated under some physical conditions or with chemical treatments, but they present high tolerance to moderately acidic or higher alkali conditions. The results provided the essential information

  18. First report of papaya meleira virus (PMeV) in Mexico | Perez-Brito ...

    African Journals Online (AJOL)

    Papaya meleira virus (PMeV), causal agent of meleira or sticky disease, is a double-stranded RNA (dsRNA) virus which has been previously reported only in Brazil. A study was carried out in order to verify the presence and occurrence of PMeV in Mexico. Latex samples from symptomatic and asymptomatic papaya fruits ...

  19. Acción inhibitoria de una cepa de Zymomonas mobilis mobilis aislada de caña de azúcar sobre Xanthomonas citri subsp. citri, agente causal de la cancrosis de los cítricos Inhibition of Xanthomonas citri subsp. citri, causal agent of citrus canker, by a strain of Zymomonas mobilis mobilis isolated from sugarcane

    Directory of Open Access Journals (Sweden)

    María E. Romero

    2008-06-01

    a wide range of microorganisms pathogenic to man, animals, and plants. An important problem to solve with antimicrobial treatments is the development of resistance in these microorganisms, including phytopathogenic bacteria, to the currently used active ingredients. In this study, antagonism tests with cells (cross-streaking and cell-free culture supernatants (CCS (agar diffusion test from Zm cultures, isolated from sugarcane juice in Tucumán, were carried out, measuring activity against Xanthomonas citri subsp. citri (Xcc, the causal agent of citrus canker. Xcc isolates sensitive (Xc and resistant (Xcr to copper pesticides were included in these tests. Results showed that indicator bacteria were completely inhibited by cells of Zm, which had a bactericide effect. Both Xc and Xcr were sensitive to the CCS in the agar diffusion method. Previous studies had revealed the deleterious effects of metabolites from Zm on cell membranes of E. coli AB1133, inhibiting the respiration of the bacteria inmediately after CCS addition. On the basis of these results, the effects of CCS on Xcc respiration were studied, verifyng a similar response. This would indicate that the site of action of these antimicrobial compounds is also located at the cell membrane of the bacteria under study. Based on these results, additional studies are suggested to evaluate Zm-derived products on the control of diseases that affect economically important crops, such as citrus canker.

  20. Detection of beet soil-borne virus and beet virus Q in sugarbeet in Greece

    NARCIS (Netherlands)

    Pavli, R.; Prins, M.; Skaracis, G.N.

    2010-01-01

    Sugar beet plants with typical rhizomania symptoms were collected from the five major cultivation zones of Greece. The presence of Beet necrotic yellow vein virus (BNYVV), the primary causal agent of the disease, was ascertained by DAS-ELISA in 38 out of 40 fields surveyed and the positive samples

  1. The metagenomic approach and causality in virology

    Directory of Open Access Journals (Sweden)

    Silvana Beres Castrignano

    2015-01-01

    Full Text Available Nowadays, the metagenomic approach has been a very important tool in the discovery of new viruses in environmental and biological samples. Here we discuss how these discoveries may help to elucidate the etiology of diseases and the criteria necessary to establish a causal association between a virus and a disease.

  2. Molecular Characterization of Novel Totivirus-Like Double-Stranded RNAs from Puccinia striiformis f. sp. tritici, the Causal Agent of Wheat Stripe Rust

    Directory of Open Access Journals (Sweden)

    Li Zheng

    2017-10-01

    Full Text Available Characterization of newly isolated mycoviruses may contribute to understanding of the evolution and diversity of viruses. Here, a deep sequencing approach was used to analyze the double-stranded RNA (dsRNA mycoviruses isolated from field-collected P. striiformis samples in China. Database searches showed the presence of at least four totivirus-like sequences, termed Puccinia striiformis virus 1 to 4 (PsV1 to 4. All of these identified sequences contained two overlapping open reading frames (ORFs which encode a putative coat protein (CP and an RNA-dependent RNA polymerase (RdRp showing similar structures to members of the genus Totivirus. Each PsV contained a -1 ribosomal frameshifting region with a slippery site and a pseudoknot structure in the overlapped regions of these ORFs, indicating that the RdRp is translated as a CP-RdRp fusion. Phylogenetic analyses based on RdRp and CP suggested that these novel viruses belong to the genus Totivirus in the family Totiviridae. The presences of these PsVs were further validated by transmission electron microscope (TEM and RT-PCR. Taken together, our results demonstrate the presence of diverse, novel totiviruses in the P. striiformis field populations.

  3. Molecular Characterization of Novel Totivirus-Like Double-Stranded RNAs from Puccinia striiformis f. sp. tritici, the Causal Agent of Wheat Stripe Rust

    Science.gov (United States)

    Zheng, Li; Lu, Xia; Liang, Xiaofei; Jiang, Shuchang; Zhao, Jing; Zhan, Gangming; Liu, Peng; Wu, Jianhui; Kang, Zhensheng

    2017-01-01

    Characterization of newly isolated mycoviruses may contribute to understanding of the evolution and diversity of viruses. Here, a deep sequencing approach was used to analyze the double-stranded RNA (dsRNA) mycoviruses isolated from field-collected P. striiformis samples in China. Database searches showed the presence of at least four totivirus-like sequences, termed Puccinia striiformis virus 1 to 4 (PsV1 to 4). All of these identified sequences contained two overlapping open reading frames (ORFs) which encode a putative coat protein (CP) and an RNA-dependent RNA polymerase (RdRp) showing similar structures to members of the genus Totivirus. Each PsV contained a -1 ribosomal frameshifting region with a slippery site and a pseudoknot structure in the overlapped regions of these ORFs, indicating that the RdRp is translated as a CP-RdRp fusion. Phylogenetic analyses based on RdRp and CP suggested that these novel viruses belong to the genus Totivirus in the family Totiviridae. The presences of these PsVs were further validated by transmission electron microscope (TEM) and RT-PCR. Taken together, our results demonstrate the presence of diverse, novel totiviruses in the P. striiformis field populations. PMID:29067018

  4. Human Ebola virus infection in West Africa: a review of available therapeutic agents that target different steps of the life cycle of Ebola virus.

    Science.gov (United States)

    Lai, Kang Yiu; Ng, Wing Yiu George; Cheng, Fan Fanny

    2014-01-01

    The recent outbreak of the human Zaire ebolavirus (EBOV) epidemic is spiraling out of control in West Africa. Human EBOV hemorrhagic fever has a case fatality rate of up to 90%. The EBOV is classified as a biosafety level 4 pathogen and is considered a category A agent of bioterrorism by Centers for Disease Control and Prevention, with no approved therapies and vaccines available for its treatment apart from supportive care. Although several promising therapeutic agents and vaccines against EBOV are undergoing the Phase I human trial, the current epidemic might be outpacing the speed at which drugs and vaccines can be produced. Like all viruses, the EBOV largely relies on host cell factors and physiological processes for its entry, replication, and egress. We have reviewed currently available therapeutic agents that have been shown to be effective in suppressing the proliferation of the EBOV in cell cultures or animal studies. Most of the therapeutic agents in this review are directed against non-mutable targets of the host, which is independent of viral mutation. These medications are approved by the Food and Drug Administration (FDA) for the treatment of other diseases. They are available and stockpileable for immediate use. They may also have a complementary role to those therapeutic agents under development that are directed against the mutable targets of the EBOV.

  5. Hepatitis C Virus Infection and Rheumatic Diseases: The Impact of Direct-Acting Antiviral Agents

    OpenAIRE

    Cacoub, Patrice; Commarmond, Cloé; Sadoun, David; Desbois, Anne claire

    2016-01-01

    International audience; Hepatitis C virus infection is associated with many extrahepatic manifestations, includingrheumatic disorders such as arthralgia, myalgia, cryoglobulinemia vasculitis, and siccasyndrome.The treatment of hepatitis C virus infection has long been based on interferon alfa, whichwas contraindicated in many autoimmune/inflammatory disorders.The emergence of new oral interferon-free combinations now offers an opportunity for patients infected with hepatitis C virus with extr...

  6. Genetics and Genomics of Cotton Leaf Curl Disease, Its Viral Causal Agents and Whitefly Vector: A Way Forward to Sustain Cotton Fiber Security

    Directory of Open Access Journals (Sweden)

    Mehboob-ur- Rahman

    2017-07-01

    Full Text Available Cotton leaf curl disease (CLCuD after its first epidemic in 1912 in Nigeria, has spread to different cotton growing countries including United States, Pakistan, India, and China. The disease is of viral origin—transmitted by the whitefly Bemisia tabaci, which is difficult to control because of the prevalence of multiple virulent viral strains or related species. The problem is further complicated as the CLCuD causing virus complex has a higher recombination rate. The availability of alternate host crops like tomato, okra, etc., and practicing mixed type farming system have further exaggerated the situation by adding synergy to the evolution of new viral strains and vectors. Efforts to control this disease using host plant resistance remained successful using two gene based-resistance that was broken by the evolution of new resistance breaking strain called Burewala virus. Development of transgenic cotton using both pathogen and non-pathogenic derived approaches are in progress. In future, screening for new forms of host resistance, use of DNA markers for the rapid incorporation of resistance into adapted cultivars overlaid with transgenics and using genome editing by CRISPR/Cas system would be instrumental in adding multiple layers of defense to control the disease—thus cotton fiber production will be sustained.

  7. Antiviral agents for preven- tion and/or treatment of influenza virus ...

    African Journals Online (AJOL)

    Repro

    endocytosis, the M2 channel's hydrogen ion transport function ordinarily facilitates acidification of the virus's interior, a process essen- tial for viral uncoating and release of the nucleic acid for transcription and translation. Adamantanes therefore prevent uncoating of the virus, and this is inhibitory to viral replication.

  8. Hepatitis C virus cell-cell transmission and resistance to direct-acting antiviral agents

    DEFF Research Database (Denmark)

    Xiao, Fei; Fofana, Isabel; Heydmann, Laura

    2014-01-01

    -targeting entry inhibitors (HTEIs) was highly effective in inhibiting viral dissemination of resistant genotype 2 viruses. Combining HTEIs with DAAs prevented antiviral resistance and led to rapid elimination of the virus in cell culture model. In conclusion, our work provides evidence that cell-cell transmission...

  9. Nuclear polyhedrosis virus as a biological control agent for Malacosoma americanum (Lepidoptera: Lasiocampidae)

    Science.gov (United States)

    R.A. Progar; M.J. Rinella; D. Fekedulegn; L. Butler

    2010-01-01

    In addition to damaging trees, the eastern tent caterpillar is implicated in early fetal loss and late-term abortion in horses. In a field study, we evaluated the potential biological control of the caterpillar using eastern tent caterpillar nuclear polyhedrosis virus (ETNPV), a naturally occurring virus that is nearly species-specific. Egg masses were hatched and...

  10. Phenotypic and molecular characterization of the causal agent of chafer beetle mortality in the wheat fields of the Kurdistan province, Iran

    Directory of Open Access Journals (Sweden)

    Karimi Keivan

    2015-07-01

    Full Text Available We report the first case of chafer beetle [Anisoplia austriaca (Herbst 1783] mortality caused by Actinomucor elegans var. elegans in wheat fields of the Kurdistan province, Iran. For three years, dead larvae of Anisoplia austriaca were collected from wheat fields of the Kurdistan province. Similar isolates of a fast-growing fungus were recovered from all samples. The fungal isolates were identified as A. elegans var. elegans based on morphological and cultural characteristics. The identity of the species was further confirmed using sequence data of the ITS (Internal Transcribed Spacer region of ribosomal DNA. Koch’s postulates were fulfilled by the inoculation of the larvae of A. austriaca and Galleria mellonella (Linnaeus, 1758 (as the model insect using the spore suspension of A. elegans var. elegans. The viability of sporangiospores was evaluated using a spore dilution technique on germination medium. The results on the pathogenicity (100% mortality in A. austriaca larvae and viability tests (germination: 95.45% demonstrated that A. elegans var. elegans can be considered as a potential biocontrol agent against the chafer beetle. Field experiments are still required to evaluate the capacity of A. elegans as a biological control agent.

  11. Presence and Distribution of Tobacco Viruses in Serbia

    Directory of Open Access Journals (Sweden)

    Nataša Duduk

    2006-01-01

    Full Text Available Infection with a large number of plant viruses could imperil tobacco yield and quality. Tobacco is a natural host for more than 20 viruses, among which the most important and economically harmful are tobacco mosaic virus (TMV, tomato spotted wilt virus (TSWV, cucumber mosaic virus (CMV, potato virus Y (PVY, alfalfa mosaic virus (AMV, tobacco ringspot virus (TRSV, tobacco each virus (TEV and tobacco vein mottling virus (TVMV.The occurence and distribution of tobacco viruses were investigated for 4 years (2002-2005. During this period many different tobacco growing localities in Vojvodina and central Serbia were monitored and samples showing virus symptoms were collected. The collected samples were tested by DAS ELISA using polyclonal antisera, specific for the detection of PVY, TSWV, TMV, CMV, AMV and TRSV.The results obtained for the tobacco virus distribution during these four years of investigation proved the presence of four economically important viruses in our country, whose frequencies varied from year to year. In 2002, 2003 and 2004, the most frequent was TSWV(86.84%; 79% and 49.56%, respectively, while in 2005 PVY was prevalent (56.16%. All viruses detected in the samples tested were present in single or mixed infections. A corellation was established between the field symptoms on tobacco and the virus causal agents.The results obtained showed that TSWV and PVY were the most important tobacco viruses in our country, so that further research of tobacco virus diseases should be directed towards their more detailed characterization.

  12. Molecular characterization of potato virus X : development of detection probes and identification of the resistance-breaking capacity of strain HB

    NARCIS (Netherlands)

    Querci, M.

    1993-01-01

    One of the principal threats to potato production is the high susceptibility of this food crop to diseases, the causal agents including bacteria, fungi, mycoplasmas, nematodes, viruses and viroids. In particular, close to 30 different viruses, and one viroid, are known to infect potato

  13. SECRET AGENT, an Arabidopsis thaliana O-GlcNAc transferase, modifies the Plum pox virus capsid protein.

    Science.gov (United States)

    Scott, Cheryl L; Hartweck, Lynn M; de Jesús Pérez, José; Chen, Dinghu; García, Juan Antonio; Olszewski, Neil E

    2006-10-30

    The capsid protein of Plum pox virus (PPV-CP) is modified with O-linked GlcNAc (O-GlcNAc). While Arabidopsis has two O-GlcNAc transferases, SECRET AGENT (SEC) and SPINDLY (SPY), previous work suggests that SEC modifies PPV-CP and that the modification plays a role in the infection process. Here, we show that when co-expressed in Escherichia coli SEC modifies PPV-CP. Deletion mapping and site-directed mutagenesis identified three threonine and a serine located near the N-terminus of PPV-CP that are modified by SEC. Two of these threonines have recently been shown to be modified in virus from plants suggesting that SEC has the same specificity in plants and E. coli.

  14. Viruses as Sole Causative Agents of Severe Acute Respiratory Tract Infections in Children.

    Science.gov (United States)

    Moesker, Fleur M; van Kampen, Jeroen J A; van Rossum, Annemarie M C; de Hoog, Matthijs; Koopmans, Marion P G; Osterhaus, Albert D M E; Fraaij, Pieter L A

    2016-01-01

    Respiratory syncytial virus (RSV) and influenza A viruses are known to cause severe acute respiratory tract infections (SARIs) in children. For other viruses like human rhinoviruses (HRVs) this is less well established. Viral or bacterial co-infections are often considered essential for severe manifestations of these virus infections. The study aims at identifying viruses that may cause SARI in children in the absence of viral and bacterial co-infections, at identifying disease characteristics associated with these single virus infections, and at identifying a possible correlation between viral loads and disease severities. Between April 2007 and March 2012, we identified children (acute respiratory tract infection (ARTI) (controls). Data were extracted from the clinical and laboratory databases of our tertiary care paediatric hospital. Patient specimens were tested for fifteen respiratory viruses with real-time reverse transcriptase PCR assays and we selected patients with a single virus infection only. Typical bacterial co-infections were considered unlikely to have contributed to the PICU or MC admission based on C-reactive protein-levels or bacteriological test results if performed. We identified 44 patients admitted to PICU with SARI and 40 patients admitted to MC with ARTI. Twelve viruses were associated with SARI, ten of which were also associated with ARTI in the absence of typical bacterial and viral co-infections, with RSV and HRV being the most frequent causes. Viral loads were not different between PICU-SARI patients and MC-ARTI patients. Both SARI and ARTI may be caused by single viral pathogens in previously healthy children as well as in children with a medical history. No relationship between viral load and disease severity was identified.

  15. Causal reasoning in physics

    CERN Document Server

    Frisch, Mathias

    2014-01-01

    Much has been written on the role of causal notions and causal reasoning in the so-called 'special sciences' and in common sense. But does causal reasoning also play a role in physics? Mathias Frisch argues that, contrary to what influential philosophical arguments purport to show, the answer is yes. Time-asymmetric causal structures are as integral a part of the representational toolkit of physics as a theory's dynamical equations. Frisch develops his argument partly through a critique of anti-causal arguments and partly through a detailed examination of actual examples of causal notions in physics, including causal principles invoked in linear response theory and in representations of radiation phenomena. Offering a new perspective on the nature of scientific theories and causal reasoning, this book will be of interest to professional philosophers, graduate students, and anyone interested in the role of causal thinking in science.

  16. Theories of Causality

    Science.gov (United States)

    Jones, Robert

    2010-03-01

    There are a wide range of views on causality. To some (e.g. Karl Popper) causality is superfluous. Bertrand Russell said ``In advanced science the word cause never occurs. Causality is a relic of a bygone age.'' At the other extreme Rafael Sorkin and L. Bombelli suggest that space and time do not exist but are only an approximation to a reality that is simply a discrete ordered set, a ``causal set.'' For them causality IS reality. Others, like Judea Pearl and Nancy Cartwright are seaking to build a complex fundamental theory of causality (Causality, Cambridge Univ. Press, 2000) Or perhaps a theory of causality is simply the theory of functions. This is more or less my take on causality.

  17. Causality in Science

    Directory of Open Access Journals (Sweden)

    Cristina Puente Águeda

    2011-10-01

    Full Text Available Causality is a fundamental notion in every field of science. Since the times of Aristotle, causal relationships have been a matter of study as a way to generate knowledge and provide for explanations. In this paper I review the notion of causality through different scientific areas such as physics, biology, engineering, etc. In the scientific area, causality is usually seen as a precise relation: the same cause provokes always the same effect. But in the everyday world, the links between cause and effect are frequently imprecise or imperfect in nature. Fuzzy logic offers an adequate framework for dealing with imperfect causality, so a few notions of fuzzy causality are introduced.

  18. Doxycycline Inducible Melanogenic Vaccinia Virus as Theranostic Anti-Cancer Agent.

    Science.gov (United States)

    Kirscher, Lorenz; Deán-Ben, Xosé Luis; Scadeng, Miriam; Zaremba, Angelika; Zhang, Qian; Kober, Christina; Fehm, Thomas Felix; Razansky, Daniel; Ntziachristos, Vasilis; Stritzker, Jochen; Szalay, Aladar A

    2015-01-01

    We reported earlier the diagnostic potential of a melanogenic vaccinia virus based system in magnetic resonance (MRI) and optoacoustic deep tissue imaging (MSOT). Since melanin overproduction lead to attenuated virus replication, we constructed a novel recombinant vaccinia virus strain (rVACV), GLV-1h462, which expressed the key enzyme of melanogenesis (tyrosinase) under the control of an inducible promoter-system. In this study melanin production was detected after exogenous addition of doxycycline in two different tumor xenograft mouse models. Furthermore, it was confirmed that this novel vaccinia virus strain still facilitated signal enhancement as detected by MRI and optoacoustic tomography. At the same time we demonstrated an enhanced oncolytic potential compared to the constitutively melanin synthesizing rVACV system.

  19. Polyoma BK virus: an emerging opportunistic infectious agent of the human central nervous system

    Directory of Open Access Journals (Sweden)

    Rodrigo Lopes da Silva

    Full Text Available BK virus, a double-stranded DNA virus, is a member of the Polyomaviridae family which is known to infect humans. Clinical evidence of disease is mostly encountered in immunosuppressed individuals such as AIDS patients or those who undergo renal or bone marrow transplantation where complications associated with BKV infection manifest commonly as a polyomavirus nephropathy or hemorrhagic cystitis, respectively. Recent evidence suggests that in addition to the JC virus (the other member of the same family known to be strongly neurotropic and responsible for the progressive multifocal leukoencephalopathy, BK virus can infect and cause clinically relevant disease in the human central nervous system. In this mini-review, an analysis of the literature is made. A special focus is given to alert clinicians to the possibility of this association during the differential diagnosis of infections of the central nervous system in the immunocompromised host.

  20. An Agent-Based Model to study the epidemiological and evolutionary dynamics of Influenza viruses

    OpenAIRE

    Drake John M; Roche Benjamin; Rohani Pejman

    2011-01-01

    Abstract Background Influenza A viruses exhibit complex epidemiological patterns in a number of mammalian and avian hosts. Understanding transmission of these viruses necessitates taking into account their evolution, which represents a challenge for developing mathematical models. This is because the phrasing of multi-strain systems in terms of traditional compartmental ODE models either requires simplifying assumptions to be made that overlook important evolutionary processes, or leads to co...

  1. Evaluación a nivel de laboratorio del efecto de 7 extractos vegetales para el control de Colletotrichum sp agente causal de la antracnosis en el cultivo de tomate de árbol - Evaluación a nivel de laboratorio del efecto de 7 extractos vegetales para el control de Colletotrichum sp agente causal de la antracnosis en el cultivo de tomate de árbol

    Directory of Open Access Journals (Sweden)

    Christian Andrei Chacin Zambrano

    2013-08-01

    Full Text Available Was evaluated in the laboratory the effect of seven plant extracts of Neem leaves and fruit (Azadirachta indica leaves of lemon grass (Swinglea glutinosa, leaves of papaya (Carica papaya, Pringamosa leaves (Urtica dioica, eucalyptus leaves (Eucalyptus camaldulensis Dehn fruits of garlic (Allium sativum L. and fruits of pepper (Capsicum annuum in the control of the fungus Colletotrichum sp causal agent of anthracnose in tomato crop tree (Cyphomandra betacea. The pathogen was isolated on PDA medium from tomato fruit tree, the extracts were obtained taking into account the process by (Marin, et. Al 2007, which consists of chopping and blending plant material deposited in plastic bucket, add water ratio 2.5:1 (water: sample processed, vol.: w, subjecting to fermentation for 24 hours. The produto was filtered using sterile gauze and package them for further evaluation. The concentrations of the treatments that worked were 25, 50, 75 and 100% of the infectious agent, determining the degree of inhibition of the pathogen in Petri dishes. The best results were obtained with the application of eucalyptus leaves, since its effect was 100% at all concentrations, without neglecting the fruits of the Neem and garlic with inhibition percentages of 75 and 60% respectively, had a behavior directly proportional to the concentrations used, since the greater the amount of extract the inhibitory effect was better in this case 75% and 100%.

  2. Functional and biophysical studies on four ceratoplatanins from the fungus Moniliophthora perniciosa, causal agent of the Witche's broom disease

    Energy Technology Data Exchange (ETDEWEB)

    Barsottini, M.; Zaparoli, G.; Garcia, O.; Pereira, G.A.G. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Oliveira, J.F.; Tiezzi, H.O.; Ambrosio, A.L.B.; Dias, S.M.G. [Laboratorio Nacional de Biociencias - LNBIO, Campinas, SP (Brazil)

    2012-07-01

    Full text: Ceratoplatanin (CP) is a secreted protein of 12.4 kDa initially identified in culture filtrates of the disease ascomycete Ceratocystis fimbriata f. sp. platani, etiological agent of the canker stain disease. CP is also the founding member of the namesake protein family, which contains fungal-secreted proteins involved in various stages of the host-fungus interaction and may act as phytotoxins or elicitors of defense response. Besides the low molecular weight, CPs have a high percentage of hydrophobic residues and share two conserved intramolecular disulfide bonds. It has been suggested that CPs have important physiological functions, including interaction with cell wall or cell membrane and manipulation of the host's defense system. Furthermore, a recent work showed that the ceratoplatanin from C. fimbriata has some degree of affinity for the saccharide 4-N-acetylglucosamine. However, its precise molecular function remains elusive. Five putative CPs have been identified in Moniliophthora perniciosa a basidiomycete fungus responsible for great economic losses in cocoa industry in the form of Witches' broom disease (WBD) , four of which had their crystal structures resolved by our group. In this work we report biophysical and functional studies on these MpCPs aiming at understanding their role and importance during the WBD progression. (author)

  3. Biocontrol traits and antagonistic potential of Bacillus amyloliquefaciens strain NJZJSB3 against Sclerotinia sclerotiorum, a causal agent of canola stem rot.

    Science.gov (United States)

    Wu, Yuncheng; Yuan, Jun; Raza, Waseem; Shen, Qirong; Huang, Qiwei

    2014-10-01

    Bacillus amyloliquefaciens strain NJZJSB3 has shown antagonism of several phytopathogens in vitro, especially Sclerotinia sclerotiorum. Both the broth culture and cell suspension of strain NJZJSB3 could completely protect the detached leaves of canola (Brassica napus) from S. sclerotiorum infection. In pot experiments, the application of strain NJZJSB3 cell suspension (10(8) CFU/ml) decreased the disease incidence by 83.3%, a result similar to commercially available fungicide (Dimetachlone). In order to investigate the potential biocontrol mechanisms of strain NJZJSB3, the nonvolatile antifungal compounds it produces were identified as iturin homologs using HPLC-ESI-MS. Antifungal volatile organic compounds were identified by gas chromatography-mass spectrometry. The detected volatiles toluene, phenol, and benzothiazole showed antifungal effects against S. sclerotiorum in chemical control experiments. Strain NJZJSB3 also produced biofilm, siderophores and cell-wall-degrading enzymes (protease and β-1,3-glucanase). These results suggest that strain NJZJSB3 can be a tremendous potential agent for the biological control of sclerotinia stem rot.

  4. The effect of locust bean gum (LBG)-based edible coatings carrying biocontrol yeasts against Penicillium digitatum and Penicillium italicum causal agents of postharvest decay of mandarin fruit.

    Science.gov (United States)

    Parafati, Lucia; Vitale, Alessandro; Restuccia, Cristina; Cirvilleri, Gabriella

    2016-09-01

    Strains belonging to Wickerhamomyces anomalus, Metschnikowia pulcherrima and Aureobasidium pullulans species were tested in vitro as biocontrol agents (BCAs) against the post-harvest pathogenic molds Penicillium digitatum and Penicillium italicum. Moreover, studies aimed at screening the antifungal activity of selected yeast strains in vivo conditions against P. digitatum and P. italicum, and investigated the efficacy of a polysaccharidic matrix, locust bean gum (LBG), enriched with the tested BCAs, in controlling postharvest decays in artificially inoculated mandarins. The population dynamics of BCAs on wounds and the magnitude of peroxidase (POD) and superoxide dismutase (SOD) in fruit tissues were also investigated after treatments of mandarins with antagonistic yeasts. W. anomalus BS91, M. pulcherrima MPR3 and A. pullulans PI1 provided excellent control of postharvest decays caused by P. digitatum and P. italicum on mandarins, both when the yeasts were used alone and in combination with LBG, which enhanced the yeast cell viability over time. Finally, the increased activity of POD and lower decrease in SOD activity in response to BCAs application in mandarin fruits confirmed their involvement in the biocontrol mechanism. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Efeito inibitório de extratos vegetais sobre Colletotrichum gloeosporioides - agente causal da podridão de frutos de mamoeiro

    Directory of Open Access Journals (Sweden)

    Ribeiro Luiz Fernando

    1999-01-01

    Full Text Available Extratos aquosos foram obtidos a partir de bulbilhos de alho, folhas de hortelã e mamona e frutos de pimenta. Após a incorporação destes extratos em BDA, obtendo-se concentrações de 100, 200, 500, 1000, 5000 e 10000 ppm, foi avaliado o crescimento e a produção de conídios de um isolado de Colletotrichum gloeosporioides, agente de podridão em frutos de mamoeiro. Os resultados demonstraram o efeito inibitório dos diferentes extratos a partir da concentração de 200 ppm. O extrato de alho inibiu o crescimento micelial, em porcentagens variáveis de 5,3 a 67,6%, porém não atuou de modo expressivo sobre a produção de conídios. Em contraposição, os extratos de hortelã, mamona e pimenta promoveram inibição menos acentuada do crescimento de micélio, porém reduziram drasticamente a produção de conídios em níveis variáveis de 41 a 84%, de acordo com as concentrações crescentes dos mesmos. As propriedades fungitóxicas detectadas nos extratos utilizados no ensaio evidenciaram o uso potencial dos mesmos como alternativa aos métodos físicos e químicos convencionalmente usados para o controle da doença.

  6. Visual Causal Feature Learning

    OpenAIRE

    Chalupka, Krzysztof; Perona, Pietro; Eberhardt, Frederick

    2014-01-01

    We provide a rigorous definition of the visual cause of a behavior that is broadly applicable to the visually driven behavior in humans, animals, neurons, robots and other perceiving systems. Our framework generalizes standard accounts of causal learning to settings in which the causal variables need to be constructed from micro-variables. We prove the Causal Coarsening Theorem, which allows us to gain causal knowledge from observational data with minimal experimental effort. The theorem prov...

  7. Water quality indicators: bacteria, coliphages, enteric viruses.

    Science.gov (United States)

    Lin, Johnson; Ganesh, Atheesha

    2013-12-01

    Water quality through the presence of pathogenic enteric microorganisms may affect human health. Coliform bacteria, Escherichia coli and coliphages are normally used as indicators of water quality. However, the presence of above-mentioned indicators do not always suggest the presence of human enteric viruses. It is important to study human enteric viruses in water. Human enteric viruses can tolerate fluctuating environmental conditions and survive in the environment for long periods of time becoming causal agents of diarrhoeal diseases. Therefore, the potential of human pathogenic viruses as significant indicators of water quality is emerging. Human Adenoviruses and other viruses have been proposed as suitable indices for the effective identification of such organisms of human origin contaminating water systems. This article reports on the recent developments in the management of water quality specifically focusing on human enteric viruses as indicators.

  8. Reasoning with Causal Cycles

    Science.gov (United States)

    Rehder, Bob

    2017-01-01

    This article assesses how people reason with categories whose features are related in causal cycles. Whereas models based on causal graphical models (CGMs) have enjoyed success modeling category-based judgments as well as a number of other cognitive phenomena, CGMs are only able to represent causal structures that are acyclic. A number of new…

  9. Causality in demand

    DEFF Research Database (Denmark)

    Nielsen, Max; Jensen, Frank; Setälä, Jari

    2011-01-01

    This article focuses on causality in demand. A methodology where causality is imposed and tested within an empirical co-integrated demand model, not prespecified, is suggested. The methodology allows different causality of different products within the same demand system. The methodology is applied...

  10. An Agent-Based Model to study the epidemiological and evolutionary dynamics of Influenza viruses

    Directory of Open Access Journals (Sweden)

    Drake John M

    2011-03-01

    Full Text Available Abstract Background Influenza A viruses exhibit complex epidemiological patterns in a number of mammalian and avian hosts. Understanding transmission of these viruses necessitates taking into account their evolution, which represents a challenge for developing mathematical models. This is because the phrasing of multi-strain systems in terms of traditional compartmental ODE models either requires simplifying assumptions to be made that overlook important evolutionary processes, or leads to complex dynamical systems that are too cumbersome to analyse. Results Here, we develop an Individual-Based Model (IBM in order to address simultaneously the ecology, epidemiology and evolution of strain-polymorphic pathogens, using Influenza A viruses as an illustrative example. Conclusions We carry out careful validation of our IBM against comparable mathematical models to demonstrate the robustness of our algorithm and the sound basis for this novel framework. We discuss how this new approach can give critical insights in the study of influenza evolution.

  11. An agent-based model to study the epidemiological and evolutionary dynamics of Influenza viruses.

    Science.gov (United States)

    Roche, Benjamin; Drake, John M; Rohani, Pejman

    2011-03-30

    Influenza A viruses exhibit complex epidemiological patterns in a number of mammalian and avian hosts. Understanding transmission of these viruses necessitates taking into account their evolution, which represents a challenge for developing mathematical models. This is because the phrasing of multi-strain systems in terms of traditional compartmental ODE models either requires simplifying assumptions to be made that overlook important evolutionary processes, or leads to complex dynamical systems that are too cumbersome to analyse. Here, we develop an Individual-Based Model (IBM) in order to address simultaneously the ecology, epidemiology and evolution of strain-polymorphic pathogens, using Influenza A viruses as an illustrative example. We carry out careful validation of our IBM against comparable mathematical models to demonstrate the robustness of our algorithm and the sound basis for this novel framework. We discuss how this new approach can give critical insights in the study of influenza evolution.

  12. H3N2 Virus as Causative Agent of ARDS Requiring Extracorporeal Membrane Oxygenation Support

    Directory of Open Access Journals (Sweden)

    Adriano Peris

    2014-01-01

    Full Text Available Pandemic influenza virus A(H1N1 2009 was associated with a higher risk of viral pneumonia in comparison with seasonal influenza viruses. The influenza season 2011-2012 was characterized by the prevalent circulation of influenza A(H3N2 viruses. Whereas most H3N2 patients experienced mild, self-limited influenza-like illness, some patients were at increased risk for influenza complications because of age or underlying medical conditions. Cases presented were patients admitted to the Intensive Care Unit (ICU of ECMO referral center (Careggi Teaching Hospital, Florence, Italy. Despite extracorporeal membrane oxygenation treatment (ECMO, one patient with H3N2-induced ARDS did not survive. Our experience suggests that viral aetiology is becoming more important and hospitals should be able to perform a fast differential diagnosis between bacterial and viral aetiology.

  13. Identification of a second family of genes in Moniliophthora perniciosa, the causal agent of witches' broom disease in cacao, encoding necrosis-inducing proteins similar to cerato-platanins.

    Science.gov (United States)

    Zaparoli, Gustavo; Cabrera, Odalys García; Medrano, Francisco Javier; Tiburcio, Ricardo; Lacerda, Gustavo; Pereira, Gonçalo Guimarães

    2009-01-01

    The hemibiotrophic basidiomycete Moniliophthora perniciosa is the causal agent of witches' broom disease in cacao. This is a dimorphic species, with monokaryotic hyphae during the biotrophic phase, which is converted to dikaryotic mycelia during the saprophytic phase. The infection in pod is characterized by the formation of hypertrophic and hyperplasic tissues in the biotrophic phase, which is followed by necrosis and complete degradation of the organ. We found at least five sequences in the fungal genome encoding putative proteins similar to cerato-platanin (CP)-like proteins, a novel class of proteins initially found in the phytopathogen Ceratocystis fimbriata. One M. perniciosa CP gene (MpCP1) was expressed in vitro and proved to have necrosis-inducing ability in tobacco and cacao leaves. The protein is present in solution as dimers and is able to recover necrosis activity after heat treatment. Transcription analysis ex planta showed that MpCP1 is more expressed in biotrophic-like mycelia than saprotrophic mycelia. The necrosis profile presented is different from that caused by M. perniciosa necrosis and ethylene-inducing proteins (MpNEPs), another family of elicitors expressed by M. perniciosa. Remarkably, a mixture of MpCP1 with MpNEP2 led to a synergistic necrosis effect very similar to that found in naturally infected plants. This is the first report of a basidiomycete presenting both NEP1-like proteins (NLPs) and CPs in its genome.

  14. Endophytic bacteria from Piper tuberculatum Jacq.: isolation, molecular characterization, and in vitro screening for the control of Fusarium solani f. sp piperis, the causal agent of root rot disease in black pepper (Piper nigrum L.).

    Science.gov (United States)

    Nascimento, S B; Lima, A M; Borges, B N; de Souza, C R B

    2015-07-06

    Endophytic bacteria have been found to colonize internal tissues in many different plants, where they can have several beneficial effects, including defense against pathogens. In this study, we aimed to identify endophytic bacteria associated with roots of the tropical piperaceae Piper tuberculatum, which is known for its resistance to infection by Fusarium solani f. sp piperis, the causal agent of black pepper (Piper nigrum) root rot disease in the Amazon region. Based on 16S rRNA gene sequence analysis, we isolated endophytes belonging to 13 genera: Bacillus, Paenibacillus, Pseudomonas, Enterobacter, Rhizobium, Sinorhizobium, Agrobacterium, Ralstonia, Serratia, Cupriavidus, Mitsuaria, Pantoea, and Staphylococcus. The results showed that 56.52% of isolates were associated with the phylum Proteobacteria, which comprised α, β, and γ classes. Other bacteria were related to the phylum Firmicutes, including Bacillus, which was the most abundant genus among all isolates. Antagonistic assays revealed that Pt12 and Pt13 isolates, identified as Pseudomonas putida and Pseudomonas sp, respectively, were able to inhibit F. solani f. sp piperis growth in vitro. We describe, for the first time, the molecular identification of 23 endophytic bacteria from P. tuberculatum, among which two Pseudomonas species have the potential to control the pathogen responsible for root rot disease in black pepper in the Amazon region.

  15. Onicomicosis: epidemiología, agentes causales y evaluación de los métodos diagnósticos de laboratorio Onychomycoses: epidemiology, causative agents and assessment of diagnostic laboratory methods

    Directory of Open Access Journals (Sweden)

    Javier R Nazar

    2012-03-01

    Full Text Available Desde marzo de 2007 hasta marzo de 2011 se estudiaron prospectivamente 414 pacientes con onicodistrofias en un laboratorio privado de Esquel. La prevalencia de onicomicosis de pie fue del 78 %; la de mano, del 58 %. Los principales agentes etiológicos fueron Trichophyton rubrum, Candida spp. y Trichophyton mentagrophytes. El desarrollo de dermatofitos prevaleció en las onicopatías de pie y el de Candida spp. en las de uñas de mano (ambos, p Since March 2007 to March 2011, 414 patients with onychopathies were prospectively analyzed. Prevalence of the toenail and fingernail mycoses was 78 % and 58 %, respectively. The major etiological agents were Trichophyton rubrum, Candida spp. and Trichophyton mentagrophytes. Dermatophytes were more frequently cultured from toenails, whereas Candida spp. from fingernails (both, p < 0.05. In candidal onychomycosis, species different from C. albicans were prevalent. A higher prevalence of toenail and fingernail mycoses, a predominance of T. rubrum in toenails (p < 0.05, and greater positivity in the direct examination (DE and in culture (both, p < 0.05 were more frequently observed in men than in women. The correlation between DE and culture was 68 %. DE and culture yields were associated with a greater size lesion. DE was more effective in onycodystrophies with duration of more than 5 years. Culture positivity was independent of nail affection chronicity.

  16. Carnation mottle virus, an important viral agent infecting carnation cut-flower crops in Mahallat of Iran.

    Science.gov (United States)

    Safari, M; Koohi Habibi, M; Mosahebi, G; Dizadji, A

    2009-01-01

    One of the most important cut-flower crops grown worldwide on commercial scale is Carnation (Dianthus caryophyllus L.). It's the main production of Mahallat where is one of the most important ornamental plants production centers of Iran. Infection of carnation with pathogens Like viral agents causes economic losses in carnation cut-flower crop. One of the viral agents of this flower is Carnation mottle virus (CarMV) which is the type member of genus Carmovirus and belongs to the Tombusviridae family. It is naturally transmitted by grafting and contacting between plants. Although its infection lead to mild symptims, it weakens the plant to infection by other pathogens. The carnation greenhouses of Mahallat were visited during 2008 January to April and 100 samples with mild mosaic symptom were collected and tested by DAS-ELISA using CarMV specific polyclonal antibody. The results showed that 75% of samples wrere infected with this virus. Mechanical inocubation of Chenopodium quinoa, C. amaranticolor and Spinacea oleracea with extracted crude sap of CarMV infected carnation Leaves in phosphate buffer (pH, 7) resulted in appearance of chlorotic and necrotic local lesions on inoculated leaves 4-7 days after incubation. The virus was partially purified using C. amaranticolor locally symptomatic leaves. Total soluble proteins were extracted from healthy and CarMV infected C. amaranticolor plants and beside partially purified preparation electrophoresed through 15% poly acrylamide get according to SDS-PAGE standard procedure. Protein bands were electroblotted onto nitrocelluse membrane and incubated with CarMV polyclonal during western immunoblot analysis according to standard method. The result revealed a distinc protein band with Mr of 35.5 kDa in total protein preparation of infected plant and viral partial pure preparation, without any reaction in those of healthy plant. RT-PCR carried out using total RNA extracted from infected plant by Rneasy Plant Mini Kit (Qiagen

  17. Radiation sensitivity of bacteria and virus in porcine xenoskin for dressing agent

    Science.gov (United States)

    Jo, Eu-Ri; Jung, Pil-Mun; Choi, Jong-il; Lee, Ju-Woon

    2012-08-01

    In this study, gamma irradiation sensitivities of bacteria and viruses in porcine skin were evaluated to establish the optimum sterilization condition for the dressing material and a xenoskin graft. Escherichia coli and Bacillus subtilis were used as model pathogens and inoculated at 106-107 log CFU/g. As model viruses, porcine parvovirus (PPV), bovine viral diarrhea virus (BVDV), and poliovirus were used and inoculated at 105-106 TCID50/g into porcine skin. The D10 value of E. coli was found to be 0.25±0.1 kGy. B. subtilis endospores produced under stressful environmental conditions showed lower radiation sensitivity as D10 was 3.88±0.3 kGy in porcine skin. The D10 values of PPV, BVDV, and poliovirus were found to be 1.73±0.2, 3.81±0.2, and 6.88±0.3 kGy, respectively. These results can offer the basic information required for inactivating pathogens by gamma irradiation and achieving dressing material and porcine skin grafts.

  18. Virus, Oncolytic Virus and Human Prostate Cancer.

    Science.gov (United States)

    Liu, Guang Bin; Zhao, Liang; Zhang, Lifang; Zhao, Kong-Nan

    2017-01-01

    Prostate cancer (PCa), a disease, is characterized by abnormal cell growth in the prostate - a gland in the male reproductive system. Although older age and a family history of the disease have been recognized as the risk factors of PCa, the cause of this cancer remains unclear. Currently, PCa is one of the leading causes of cancer death among men of all races. In this review study, we first discuss the controversy of the contribution of virus infection to PCa, and subsequently summarize the development of oncolytic virotherapy for PCa in the past several years. Mounting evidence suggests that infections with various viruses are causally linked to PCa pathogenesis. Published studies have provided strong evidence that at least two viruses (RXMV and HPV) contribute to prostate tumourigenicity and impact on the survival of patients with malignant PCa. Traditional therapies including chemotherapy and radiotherapy are unable to distinguish cancer cells from normal cells, which are a significant drawback and leads to toxicities for PCa patients undergoing treatment. So far, few other options are available for treating patients with advanced PCa. For PCa treatment, oncolytic virotherapy appears to be much more attractive, which uses live viruses to selectively kill cancer cells. Oncolytic viruses can be genetically engineered to induce cancer cell lysis through virus replication and expression of cytotoxic proteins. Virotherapy is being developed to be a novel therapy for cancers, which uses oncotropic and oncolytic viruses with their abilities to find and destroy malignant cells in the body. As oncolytic viruses are a relatively new class of anti-cancer immunotherapy agents, several important barriers still exist on the road to the use of oncolytic viruses for PCa therapy. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Novas raças de Bremia lactucae, agente causador do míldio da alface, identificadas no estado de São Paulo New races of Bremia lactucae, causal agent of lettuce downy mildew, identified in São Paulo state, Brazil

    Directory of Open Access Journals (Sweden)

    Jean de O Souza

    2011-09-01

    Full Text Available O objetivo deste trabalho foi relatar o surgimento de raças de Bremia lactucae, agente causal do míldio nas principais regiões produtoras de alface do estado de São Paulo. O estudo foi realizado no Laboratório de Melhoramento Genético de Hortaliças do Departamento de Produção Vegetal da UNESP, Campus de Jaboticabal. No período de 2006 e 2007, foram coletados 36 isolados de B. lactucae de diferentes regiões produtoras de alface no estado. Para identificação das raças foram utilizadas as cultivares diferenciadoras conforme o código "Sextet". Foram identificadas três novas raças, SPBl:02, SPBl:03 e SPBl:04 com os referidos comportamentos do fungo: (63/31/19/00, (63/63/19/00 e (63/63/03/00. Os genes Dm-14, Dm-17, Dm-18, Dm-37 e Dm-38 conferem resistência a essas novas raças identificadas.The objective of this paper was to report new races of lettuce downy mildew causal agent Bremia lactucae in São Paulo State. The study was carried out in the laboratory of Crop Genetics in the Department of Crop Science at the college of Agricultural and Veterinary Sciences, Jaboticabal campus. A total of 36 isolates of B. lactucae was collected in different regions. The identification of races was based on compatibility reaction on the differential cultivars of the "Sextet". Three new races of B. lactucae, SPBl:02 (63/31/19/00, SPBl:03 (63/63/19/00 and SPBl:04 (63/63/03/00 were identified according to "Sextet" code. Genes Dm-14, Dm-17, Dm-18, Dm-37 and Dm-38 confer resistance to these new races identified.

  20. Deciphering the potential of baicalin as an antiviral agent for Chikungunya virus infection.

    Science.gov (United States)

    Oo, Adrian; Rausalu, Kai; Merits, Andres; Higgs, Stephen; Vanlandingham, Dana; Bakar, Sazaly Abu; Zandi, Keivan

    2018-02-01

    The past decade has seen the re-emergence of Chikungunya virus (CHIKV) as a major global health threat, affecting millions around the world. Although fatal infections are rare among infected patients, the occurrence of long-lasting polyarthralgia has a significant impact on patients' quality of lives and ability to work. These issues were the stimuli for this study to determine the potential of baicalin, a bioflavonoid, as the novel antiviral compound against CHIKV. It was found that baicalin was well tolerated by Vero, BHK-21 and HEK 293T cells with maximal nontoxic doses >600 μM, ≈ 350 μM and ≈110 μM, respectively. Antiviral assays indicated that baicalin was the most effective inhibitor when tested for its direct virucidal activity with EC 50  ≈ 7 μM, followed by inhibition of virus entry into the host cell, attachment of virus particle to cellular receptors and finally intracellular replication of viral RNA genome. In silico analysis using molecular docking demonstrated close interactions between baicalin and CHIKV envelope protein with considerably strong binding affinity of -9.7 kcal/mol. qRT-PCR analysis revealed that baicalin had the greatest effect on the synthesis of viral negative stand RNA with EC 50  ≈ 0.4 μM followed by the inhibition of synthesis of positive-strand genomic (EC 50  ≈ 13 μM) and subgenomic RNAs (EC 50  ≈ 14 μM). These readings indicate that the compound efficiently inhibits replicase complexes formation but is a less potent inhibitor of existing replicase complexes. Coherent with this hypothesis, the use of recombinant CHIKV replicons harboring Renilla luciferase marker showed that replication of corresponding replicon RNAs was only slightly downregulated at higher doses of baicalin, with EC 50  > 100 μM. Immunofluorescence and western blotting experiments demonstrated dose-dependent inhibition of expression of different viral proteins. It was also observed that levels of important protein markers

  1. Evaluation of Human Papilloma Virus Communicative Education Strategies: A Pilot Screening Study for Cervical Cancer

    Science.gov (United States)

    Barrera-Clavijo, Lizeth K.; Wiesner-Ceballos, Carolina; Rincón-Martínez, Lina M.

    2016-01-01

    Background: High-risk human papilloma virus (HR-HPV) is highly prevalent in sexually active men and women; HR-HPV has been classified as a sexually transmitted infection (STI) and as a necessary, but not sufficient, causal agent for cervical cancer. Women who test positive for HPV often experience serious psychosocial consequences such as fear,…

  2. Verrugas plantares: caracterización de los virus causales y aplicación del láser 1064 nm a su tratamiento

    OpenAIRE

    Planell Mas, Elena de

    2016-01-01

    INTRODUCCIÓN: Las verrugas plantares están provocadas por el virus del papilloma humano (VPH). Se han descrito diferentes genotipos asociados a estas lesiones si bien existen pocos estudios centrados exclusivamente en los genotipos de las verrugas plantares. El diagnóstico generalmente es clínico, aunque actualmente existen métodos diagnósticos basados en la detección del ADN viral como es el caso de la PCR (polymerase chain reaction). Las modalidades de tratamiento de las verrugas so...

  3. Caracterización taxonómica y análisis de la variabilidad del agente causal del cancro del tallo de la soja en Buenos Aires (2005/2007

    Directory of Open Access Journals (Sweden)

    GRIJALBA, P.E

    2011-12-01

    Full Text Available ResumenEl complejo Diaporthe/Phomopsis es un importante grupo de hongos patógenos de la soja. Dentro del mismo, Diaporthe phaseolorum var. caulivora es uno de los agentes causales del cancro del tallo. Veintitrés aislamientos de este hongo, provenientes de diferentes zonas geográficas de la provincia de Buenos Aires, fueron caracterizados morfológica y genéticamente. Los criterios morfológicos fueron tipo y color de micelio; formación del teleomorfo y/o del anamorfo. La identificación molecular fue llevada a cabo utilizando una técnica de restricción de fragmentos de amplificación (PCR-RFLP de la región ITS de ADN ribosomal. Adicionalmente, los productos de amplificación fueron secuenciados y comparados con la información de bancos de datos. Los aislamientos presentaron características morfológicas y patogénicas propias de la variedad, y los patrones de restricción con la enzima Alu I fueron concordantes con la identificación morfológica y con la información de secuencias disponibles. Las reconstrucciones filogenéticas apoyan la idea de que D. meridionalis y D. caulivora son entidades biológicamente aisladas. Los resultados obtenidos confirmaron la utilidad del uso del método de PCR-RFLP para la identificación precisa y rápida de D. caulivora. Por sus características, este método puede ser implementado para análisis de rutina en laboratorios de pequeña y mediana escala.AbstractDiaporthe/Phomopsis is an important group of soybean pathogens. Diaporthe phaseolorum var. caulivora is one of the causal agents of stem canker. Twenty three isolates from different regions from the Province of Buenos Aires were morphologically and genetically characterized and assigned to different taxa within the Diaporthe/Phomopsis complex; diagnostic morphological traits were: mycelium type and color, teleomorph/anamorph occurrence. Molecular characterization was carried out using RFLP analyses of PCR-amplified DNA (PCRRFLP for the

  4. Inhibition of MLC phosphorylation restricts replication of influenza virus--a mechanism of action for anti-influenza agents.

    Directory of Open Access Journals (Sweden)

    Mehran Haidari

    Full Text Available Influenza A viruses are a severe threat worldwide, causing large epidemics that kill thousands every year. Prevention of influenza infection is complicated by continuous viral antigenic changes. Newer anti-influenza agents include MEK/ERK and protein kinase C inhibitors; however, the downstream effectors of these pathways have not been determined. In this study, we identified a common mechanism for the inhibitory effects of a significant group of anti-influenza agents. Our studies showed that influenza infection activates a series of signaling pathways that converge to induce myosin light chain (MLC phosphorylation and remodeling of the actin cytoskeleton. Inhibiting MLC phosphorylation by blocking RhoA/Rho kinase, phospholipase C/protein kinase C, and HRas/Raf/MEK/ERK pathways with the use of genetic or chemical manipulation leads to the inhibition of influenza proliferation. In contrast, the induction of MLC phosphorylation enhances influenza proliferation, as does activation of the HRas/Raf/MEK/ERK signaling pathway. This effect is attenuated by inhibiting MLC phosphorylation. Additionally, in intracellular trafficking studies, we found that the nuclear export of influenza ribonucleoprotein depends on MLC phosphorylation. Our studies provide evidence that modulation of MLC phosphorylation is an underlying mechanism for the inhibitory effects of many anti-influenza compounds.

  5. El virus de la D.V.B. como agente contaminante en cultivo de tejidos animales

    Directory of Open Access Journals (Sweden)

    Víctor J. Vera A.

    1992-03-01

    Full Text Available El Pestisvirus que produce la Diarrea Viral Bovina (V.D.V.B., ocasiona problemas reproductivos en el ganado vacuno y se encuentra ampliamente difundido en el país. La presencia de cepas no citopatogénicas del mismo, las cuales normalmente no se evidencian en los cultivos celulares contaminados con éste virus, han constituido un Iimitante para el establecimiento y mantenimiento de cultivos primarios y líneas celulares libres del V.D.V.B., para uso rutinario en actividades diagnósticas o investigativas. El suero fetal bovino (SFB es la fuente usual de contaminación para los cultivos de tejidos animales, dadas las escasas previsiones para el control de su calidad, ya que la recolección y mercadeo del SFB se realiza con criterios artesanales y sin los debidos controles de calidad. Específicamente en el caso del V.D.V.B., se pueden presentar dos situaciones con el SFB: que contenga partículas virales o que posea niveles de anticuerpos contra el virus; en ambos casos se darán problemas en los procedimientos realizados con dichos sueros. Con el fin de controlar las contaminaciones de los cultivos celulares con el VDVB, en el Postgrado de la Facultad de Medicina Veterinaria de la Universidad Nacional, se ha empleado la técnica de Inmunofluorescencia Indirecta (IFl para detectarlas tanto, en el SFB como en diferentes cultivos celulares, obteniéndose para el SFB el 25.8% de positivos de un total de 32 muestras de diferentes orígenes y para los cultivos celulares el 42.8% de positivos de 28 lotes, procedentes de diferente origen animal y centros de investigación, resultados que son comparables con los obtenidos por otros laboratorios internacionales como el National Animal Diseases Laboratory (NADL del Departamento de Agricultura de USA. Dentro de las recomendaciones para la prevención y control del problema en laboratorios de diagnóstico e investigación médica y veterinaria, que empleen tecnologías relacionadas con manejo y

  6. Causality in Classical Physics

    Indian Academy of Sciences (India)

    IAS Admin

    Classical physics encompasses the study of phys- ical phenomena which range from local (a point) to nonlocal (a region) in space and/or time. We discuss the concept of spatial and temporal non- locality. However, one of the likely implications pertaining to nonlocality is non-causality. We study causality in the context of ...

  7. Regression to Causality

    DEFF Research Database (Denmark)

    Bordacconi, Mats Joe; Larsen, Martin Vinæs

    2014-01-01

    Humans are fundamentally primed for making causal attributions based on correlations. This implies that researchers must be careful to present their results in a manner that inhibits unwarranted causal attribution. In this paper, we present the results of an experiment that suggests regression...... models – one of the primary vehicles for analyzing statistical results in political science – encourage causal interpretation. Specifically, we demonstrate that presenting observational results in a regression model, rather than as a simple comparison of means, makes causal interpretation of the results...... of equivalent results presented as either regression models or as a test of two sample means. Our experiment shows that the subjects who were presented with results as estimates from a regression model were more inclined to interpret these results causally. Our experiment implies that scholars using regression...

  8. Agency, time and causality

    Directory of Open Access Journals (Sweden)

    Thomas eWidlok

    2014-11-01

    Full Text Available Cognitive Scientists interested in causal cognition increasingly search for evidence from non-WEIRD people but find only very few cross-cultural studies that specifically target causal cognition. This article suggests how information about causality can be retrieved from ethnographic monographs, specifically from ethnographies that discuss agency and concepts of time. Many apparent cultural differences with regard to causal cognition dissolve when cultural extensions of agency and personhood to non-humans are taken into account. At the same time considerable variability remains when we include notions of time, linearity and sequence. The article focuses on ethnographic case studies from Africa but provides a more general perspective on the role of ethnography in research on the diversity and universality of causal cognition.

  9. Non-Causal Computation

    Directory of Open Access Journals (Sweden)

    Ämin Baumeler

    2017-07-01

    Full Text Available Computation models such as circuits describe sequences of computation steps that are carried out one after the other. In other words, algorithm design is traditionally subject to the restriction imposed by a fixed causal order. We address a novel computing paradigm beyond quantum computing, replacing this assumption by mere logical consistency: We study non-causal circuits, where a fixed time structure within a gate is locally assumed whilst the global causal structure between the gates is dropped. We present examples of logically consistent non-causal circuits outperforming all causal ones; they imply that suppressing loops entirely is more restrictive than just avoiding the contradictions they can give rise to. That fact is already known for correlations as well as for communication, and we here extend it to computation.

  10. Interleukin 37 expression in mice alters sleep responses to inflammatory agents and influenza virus infection

    Directory of Open Access Journals (Sweden)

    Christopher J. Davis

    2017-06-01

    Full Text Available Multiple interactions between the immune system and sleep are known, including the effects of microbial challenge on sleep or the effects of sleep loss on facets of the immune response. Cytokines regulate, in part, sleep and immune responses. Here we examine the role of an anti-inflammatory cytokine, interleukin-37 (IL-37 on sleep in a mouse strain that expresses human IL-37b (IL37tg mice. Constitutive expression of the IL-37 gene in the brains of these mice under resting conditions is low; however, upon an inflammatory stimulus, expression increases dramatically. We measured sleep in three conditions; (a under baseline conditions and after 6 h of sleep loss, (b after bolus intraperitoneal administration of lipopolysaccharide (LPS or IL-1β and (c after intranasal influenza virus challenge. Under baseline conditions, the IL37tg mice had 7% more spontaneous non-rapid eye movement sleep (NREMS during the light period than wild-type (WT mice. After sleep deprivation both WT mice and IL37tg mice slept an extra 21% and 12%, respectively, during the first 6 h of recovery. NREMS responses after sleep deprivation did not significantly differ between WT mice and IL37tg mice. However, in response to either IL-1β or LPS, the increases in time spent in NREMS were about four-fold greater in the WT mice than in the IL37tg mice. In contrast, in response to a low dose of mouse-adapted H1N1 influenza virus, sleep responses developed slowly over the 6 day recording period. By day 6, NREMS increased by 10% and REMS increased by 18% in the IL37tg mice compared to the WT mice. Further, by day 4 IL37tg mice lost less weight, remained more active, and retained their body temperatures closer to baseline values than WT mice. We conclude that conditions that promote IL-37 expression attenuate morbidity to severe inflammatory challenge.

  11. Cynaropicrin: a comprehensive research review and therapeutic potential as an anti- hepatitis C virus agent

    Directory of Open Access Journals (Sweden)

    Mahmoud Fahmi Elsebai

    2016-12-01

    Full Text Available The different pharmacologic properties of plants-containing cynaropicrin, especially artichokes, have been known for many centuries. More recently, cynaropicrin exhibited a potential activity against all genotypes of hepatitis C virus (HCV. Cynaropicrin has also shown a wide range of other pharmacologic properties such as anti-hyperlipidemic, anti-trypanosomal, anti-malarial, antifeedant, antispasmodic, anti-photoaging, and anti-tumor action, as well as activation of bitter sensory receptors, and anti-inflammatory properties (e.g., associated with the suppression of the key pro-inflammatory NF-κB pathway. These pharmacological effects are very supportive factors to its outstanding activity against HCV. Structurally, cynaropicrin might be considered as a potential drug candidate, since it has no violations for the rule of five and its water-solubility could allow formulation as therapeutic injections. Moreover, cynaropicrin is a small molecule that can be easily synthesized and as the major constituent of the edible plant artichoke, which has a history of safe dietary use. In summary, cynaropicrin is a promising bioactive natural product that, with minor hit-to-lead optimization, might be developed as a drug for HCV.

  12. Causal Networks or Causal Islands? The Representation of Mechanisms and the Transitivity of Causal Judgment

    Science.gov (United States)

    Johnson, Samuel G. B.; Ahn, Woo-kyoung

    2015-01-01

    Knowledge of mechanisms is critical for causal reasoning. We contrasted two possible organizations of causal knowledge--an interconnected causal "network," where events are causally connected without any boundaries delineating discrete mechanisms; or a set of disparate mechanisms--causal "islands"--such that events in different…

  13. Antigen-presenting particle technology using inactivated surface-engineered viruses: induction of immune responses against infectious agents

    Directory of Open Access Journals (Sweden)

    Chang Yung-Nien

    2007-05-01

    Full Text Available Abstract Background Developments in cell-based and gene-based therapies are emerging as highly promising areas to complement pharmaceuticals, but present day approaches are too cumbersome and thereby limit their clinical usefulness. These shortcomings result in procedures that are too complex and too costly for large-scale applications. To overcome these shortcomings, we described a protein delivery system that incorporates over-expressed proteins into viral particles that are non-infectious and stable at room temperature. The system relies on the biological process of viral egress to incorporate cellular surface proteins while exiting their host cells during lytic and non-lytic infections. Results We report here the use of non-infectious surface-engineered virion particles to modulate immunity against three infectious disease agents – human immunodeficiency virus type 1 (HIV-1, herpes simplex virus (HSV, and Influenza. Surface-engineering of particles are accomplished by genetic modification of the host cell surface that produces the egress budding viral particle. Human peripheral blood lymphocytes from healthy donors exposed to CD80/B7.1, CD86/B7.2, and/or antiCD3 single-chain antibody surface-engineered non-infectious HIV-1 and HSV-2 particles stimulate T cell proliferation, whereas particles released from non-modified host cells have no T cell stimulatory activity. In addition to T cell proliferation, HIV-based particles specifically suppress HIV-1 replication (both monocytotropic and lymphocytotropic strains 55 to 96% and HSV-based particles specifically induce cross-reactive HSV-1/HSV-2 anti-herpes virus antibody production. Similar surface engineering of influenza-based particles did not modify the intrinsic ability of influenza particles to stimulate T cell proliferation, but did bestow on the engineered particles the ability to induce cross-strain anti-influenza antibody production. Conclusion We propose that non-infectious viral

  14. Treatment of hepatitis C virus genotype 3 infection with direct-acting antiviral agents

    Directory of Open Access Journals (Sweden)

    L.P. Zanaga

    Full Text Available Hepatitis C virus (HCV genotype 3 is responsible for 30.1% of chronic hepatitis C infection cases worldwide. In the era of direct-acting antivirals, these patients have become one of the most challenging to treat, due to fewer effective drug options, higher risk of developing cirrhosis and hepatocellular carcinoma and lower sustained virological response (SVR rates. Currently there are 4 recommended drugs for the treatment of HCV genotype 3: pegylated interferon (PegIFN, sofosbuvir (SOF, daclatasvir (DCV and ribavirin (RBV. Treatment with PegIFN, SOF and RBV for 12 weeks has an overall SVR rate of 83–100%, without significant differences among cirrhotic and non-cirrhotic patients. However, this therapeutic regimen has several contraindications and can cause significant adverse events, which can reduce adherence and impair SVR rates. SOF plus RBV for 24 weeks is another treatment option, with SVR rates of 82–96% among patients without cirrhosis and 62–92% among those with cirrhosis. Finally, SOF plus DCV provides 94–97% SVR rates in non-cirrhotic patients, but 59–69% in those with cirrhosis. The addition of RBV to the regimen of SOF plus DCV increases the SVR rates in cirrhotic patients above 80%, and extending treatment to 24 weeks raises SVR to 90%. The ideal duration of therapy is still under investigation. For cirrhotic patients, the optimal duration, or even the best regimen, is still uncertain. Further studies are necessary to clarify the best regimen to treat HCV genotype 3 infection.

  15. In vivo protocol for testing efficacy of hand-washing agents against viruses and bacteria: experiments with rotavirus and Escherichia coli.

    Science.gov (United States)

    Ansari, S A; Sattar, S A; Springthorpe, V S; Wells, G A; Tostowaryk, W

    1989-01-01

    Ten antiseptic formulations, an unmedicated liquid soap, and tap water alone were compared for their capacities to eliminate human rotavirus from the finger pads of adult volunteers; three of the antiseptics, the soap, and the tap water alone were also tested against Escherichia coli. A fecal suspension of virus or bacterium was placed on each finger pad and air dried. The contaminated site was exposed to the test product for 10 s, rinsed in tap water, and dried on a paper towel. The residual virus or bacterium was then eluted. Selected agents were also tested by an analogous whole-hand method by which the entire palm surfaces of both hands were contaminated. Alcohols (70%) alone or with Savlon reduced the virus titer by greater than 99%, whereas the reductions by Proviodine, Dettol, and Hibisol ranged from 95 to 97%. Aqueous solutions of chlorhexidine gluconate were significantly less effective for virus removal or inactivation than 70% alcohol solutions. Furthermore, Savlon in water (1:200) was found to be much less effective in eliminating the virus (80.6%) than the bacterium (98.9%). The tap water alone and the soap reduced the virus titers by 83.6 and 72.5% and the bacterial titers by 90 and 68.7%, respectively. The results of the whole-hand method agreed well with those of the finger pad protocol. We conclude that the finger pad method is a suitable model for testing the in vivo efficacy of hand-washing agents and emphasize the need for using appropriate test viruses and bacteria. PMID:2559658

  16. Quantum Causal Graph Dynamics

    CERN Document Server

    Arrighi, Pablo

    2016-01-01

    Consider a graph having quantum systems lying at each node. Suppose that the whole thing evolves in discrete time steps, according to a global, unitary causal operator. By causal we mean that information can only propagate at a bounded speed, with respect to the distance given by the graph. Suppose, moreover, that the graph itself is subject to the evolution, and may be driven to be in a quantum superposition of graphs---in accordance to the superposition principle. We show that these unitary causal operators must decompose as a finite-depth circuit of local unitary gates. This unifies a result on Quantum Cellular Automata with another on Reversible Causal Graph Dynamics. Along the way we formalize a notion of causality which is valid in the context of quantum superpositions of time-varying graphs, and has a number of good properties. Keywords: Quantum Lattice Gas Automata, Block-representation, Curtis-Hedlund-Lyndon, No-signalling, Localizability, Quantum Gravity, Quantum Graphity, Causal Dynamical Triangula...

  17. Update and Commentary on Four Emerging Tick-Borne Infections: Ehrlichia muris-like Agent, Borrelia miyamotoi, Deer Tick Virus, Heartland Virus, and Whether Ticks Play a Role in Transmission of Bartonella henselae.

    Science.gov (United States)

    Wormser, Gary P; Pritt, Bobbi

    2015-06-01

    Emerging tick-borne infections continue to be observed in the United States and elsewhere. Current information on the epidemiology, clinical and laboratory features, and treatment of infections due to Ehrlichia muris-like agent, deer tick virus, Borrelia miyamotoi sensu lato, and Heartland virus was provided and critically reviewed. More research is needed to define the incidence and to understand the clinical and the laboratory features of these infections. There is also a growing need for the development of sensitive and specific serologic and molecular assays for these infections that are easily accessible to clinicians. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Caractérisation des virus de la maladie de Newcastle (APMV-1), circulant sur les hautes terres de Madagascar

    OpenAIRE

    Maminiaina, Olivier Fridolin

    2011-01-01

    La maladie de Newcastle (MN) est une maladie infectieuse des volailles essentiellement les gallinacees. L'agent causal de cette maladie est une forme virulente des paramyxovirus aviaires type 1 (APMV-1). Les APMV-1 sont des virus a ARN negatif monocatenaire non segmente, dans la famille des Paramyxoviridae, genre Avulavirus. Le genome de ce virus code pour six proteines structurales dont l'ARN polymerase ARNdependant (L gene), la hemagglutinine-neuraminidase (gene de HN), la fusion (gene de F...

  19. Causal inference regarding infectious aetiology of chronic conditions: a systematic review.

    Directory of Open Access Journals (Sweden)

    Sofia Orrskog

    Full Text Available BACKGROUND: The global burden of disease has shifted from communicable diseases in children to chronic diseases in adults. This epidemiologic shift varies greatly by region, but in Europe, chronic conditions account for 86% of all deaths, 77% of the disease burden, and up to 80% of health care expenditures. A number of risk factors have been implicated in chronic diseases, such as exposure to infectious agents. A number of associations have been well established while others remain uncertain. METHODS AND FINDINGS: We assessed the body of evidence regarding the infectious aetiology of chronic diseases in the peer-reviewed literature over the last decade. Causality was assessed with three different criteria: First, the total number of associations documented in the literature between each infectious agent and chronic condition; second, the epidemiologic study design (quality of the study; third, evidence for the number of Hill's criteria and Koch's postulates that linked the pathogen with the chronic condition. We identified 3136 publications, of which 148 were included in the analysis. There were a total of 75 different infectious agents and 122 chronic conditions. The evidence was strong for five pathogens, based on study type, strength and number of associations; they accounted for 60% of the associations documented in the literature. They were human immunodeficiency virus, hepatitis C virus, Helicobacter pylori, hepatitis B virus, and Chlamydia pneumoniae and were collectively implicated in the aetiology of 37 different chronic conditions. Other pathogens examined were only associated with very few chronic conditions (≤ 3 and when applying the three different criteria of evidence the strength of the causality was weak. CONCLUSIONS: Prevention and treatment of these five pathogens lend themselves as effective public health intervention entry points. By concentrating research efforts on these promising areas, the human, economic, and societal

  20. Enhanced vesicular stomatitis virus (VSVΔ51 targeting of head and neck cancer in combination with radiation therapy or ZD6126 vascular disrupting agent

    Directory of Open Access Journals (Sweden)

    Alajez Nehad M

    2012-06-01

    Full Text Available Abstract Background Head and neck squamous cell carcinoma (HNSCC is the 5th most common cancer worldwide. Locally advanced HNSCC are treated with either radiation or chemo-radiotherapy, but still associated with high mortality rate, underscoring the need to develop novel therapies. Oncolytic viruses have been garnering increasing interest as anti-cancer agents due to their preferential killing of transformed cells. In this study, we evaluated the therapeutic potential of mutant vesicular stomatitis virus (VSVΔ51 against the human hypopharyngeal FaDu tumour model in vitro and in vivo. Results Our data demonstrated high toxicity of the virus against FaDu cells in vitro, which was associated with induction of apoptosis. In vivo, systemic injection of 1 × 109 pfu had minimal effect on tumour growth; however, when combined with two doses of ionizing radiation (IR; 5 Gy each or a single injection of the vascular disrupting agent (ZD6126, the virus exhibited profound suppression of tumour growth, which translated to a prolonged survival in the treated mice. Concordantly, VSVΔ51 combined with ZD6126 led to a significant increase in viral replication in these tumours. Conclusions Our data suggest that the combinations of VSVΔ51 with either IR or ZD6126 are potentially novel therapeutic opportunities for HNSCC.

  1. Causality discovery technology

    Science.gov (United States)

    Chen, M.; Ertl, T.; Jirotka, M.; Trefethen, A.; Schmidt, A.; Coecke, B.; Bañares-Alcántara, R.

    2012-11-01

    Causality is the fabric of our dynamic world. We all make frequent attempts to reason causation relationships of everyday events (e.g., what was the cause of my headache, or what has upset Alice?). We attempt to manage causality all the time through planning and scheduling. The greatest scientific discoveries are usually about causality (e.g., Newton found the cause for an apple to fall, and Darwin discovered natural selection). Meanwhile, we continue to seek a comprehensive understanding about the causes of numerous complex phenomena, such as social divisions, economic crisis, global warming, home-grown terrorism, etc. Humans analyse and reason causality based on observation, experimentation and acquired a priori knowledge. Today's technologies enable us to make observations and carry out experiments in an unprecedented scale that has created data mountains everywhere. Whereas there are exciting opportunities to discover new causation relationships, there are also unparalleled challenges to benefit from such data mountains. In this article, we present a case for developing a new piece of ICT, called Causality Discovery Technology. We reason about the necessity, feasibility and potential impact of such a technology.

  2. Causal symmetric spaces

    CERN Document Server

    Olafsson, Gestur; Helgason, Sigurdur

    1996-01-01

    This book is intended to introduce researchers and graduate students to the concepts of causal symmetric spaces. To date, results of recent studies considered standard by specialists have not been widely published. This book seeks to bring this information to students and researchers in geometry and analysis on causal symmetric spaces.Includes the newest results in harmonic analysis including Spherical functions on ordered symmetric space and the holmorphic discrete series and Hardy spaces on compactly casual symmetric spacesDeals with the infinitesimal situation, coverings of symmetric spaces, classification of causal symmetric pairs and invariant cone fieldsPresents basic geometric properties of semi-simple symmetric spacesIncludes appendices on Lie algebras and Lie groups, Bounded symmetric domains (Cayley transforms), Antiholomorphic Involutions on Bounded Domains and Para-Hermitian Symmetric Spaces

  3. Causal inference in econometrics

    CERN Document Server

    Kreinovich, Vladik; Sriboonchitta, Songsak

    2016-01-01

    This book is devoted to the analysis of causal inference which is one of the most difficult tasks in data analysis: when two phenomena are observed to be related, it is often difficult to decide whether one of them causally influences the other one, or whether these two phenomena have a common cause. This analysis is the main focus of this volume. To get a good understanding of the causal inference, it is important to have models of economic phenomena which are as accurate as possible. Because of this need, this volume also contains papers that use non-traditional economic models, such as fuzzy models and models obtained by using neural networks and data mining techniques. It also contains papers that apply different econometric models to analyze real-life economic dependencies.

  4. VIRUSES

    Indian Academy of Sciences (India)

    and-mouth disease in livestock was an infectious particle smaller than any bacteria. This was the first clue to the nature of viruses, genetic entities that lie somewhere in the gray area between living and non-living states.

  5. Identification and application of biocontrol agents against Cotton leaf curl virus disease in Gossypium hirsutum under greenhouse conditions

    Directory of Open Access Journals (Sweden)

    Memoona Ramzan

    2016-05-01

    Full Text Available Biological control is a novel approach in crop protection. Bacteria, such as Bacillus spp. and Pseudomonas spp., are reported for this purpose and some of their products are already commercially available. In this study, the rhizosphere and phyllosphere of healthy cotton plants were used as a source of bacterial isolates with properties of potential biocontrol agents. The isolates were screened for phosphate solubilization activity, indole acetic acid (IAA production and antifungal activity. Two isolates, S1HL3 and S1HL4, showed phosphate solubilization and IAA production simultaneously, while another two, JS2HR4 and JS3HR2, demonstrated potential to inhibit fungal pathogens. These bacteria were identified as Pseudomonas aeruginosa (S1HL3, Burkholderia sp. (S1HL4 and Bacillus sp. (JS2HR4 and JS3HR2 based on biochemical and molecular characteristics. The isolates were tested against Cotton leaf curl virus (CLCuV in greenhouse conditions, both as individual bacterial isolates and consortia. Treated plants were healthy as compared to control plants, where up to 74% of the plants were symptomatic for CLCuV infection. Maximum inhibition of CLCuV was observed in the plants treated with a mixture of bacterial isolates: the viral load in the treated plants was only 0.4% vs. up to 74% in controls. This treatment consortium included P. aeruginosa S1HL3, Burkholderia sp. S1HL4 and Bacillus spp. isolates, JS2HR4 and JS3HR2. The principal-component biplot showed a highly significant correlation between the viral load percentage and the disease incidence.

  6. Efficacy of CMX001 as a Prophylactic and Presymptomatic Antiviral Agent in New Zealand White Rabbits Infected with Rabbitpox Virus, a Model for Orthopoxvirus Infections of Humans

    Directory of Open Access Journals (Sweden)

    Richard W. Moyer

    2011-01-01

    Full Text Available CMX001, a lipophilic nucleotide analog formed by covalently linking 3‑(hexdecyloxypropan-1-ol to cidofovir (CDV, is being developed as a treatment for smallpox. CMX001 has dramatically increased potency versus CDV against all dsDNA viruses and, in contrast to CDV, is orally available and has shown no evidence of nephrotoxicity in healthy volunteers or severely ill transplant patients to date. Although smallpox has been eliminated from the environment, treatments are urgently being sought due to the risk of smallpox being used as a bioterrorism agent and for monkeypox virus, a zoonotic disease of Africa, and adverse reactions to smallpox virus vaccinations. In the absence of human cases of smallpox, new treatments must be tested for efficacy in animal models. Here we first review and discuss the rabbitpox virus (RPV infection of New Zealand White rabbits as a model for smallpox to test the efficacy of CMX001 as a prophylactic and early disease antiviral. Our results should also be applicable to monkeypox virus infections and for treatment of adverse reactions to smallpox vaccination.

  7. Efficacy of CMX001 as a prophylactic and presymptomatic antiviral agent in New Zealand white rabbits infected with rabbitpox virus, a model for orthopoxvirus infections of humans.

    Science.gov (United States)

    Rice, Amanda D; Adams, Mathew M; Lampert, Bernhard; Foster, Scott; Robertson, Alice; Painter, George; Moyer, Richard W

    2011-02-01

    CMX001, a lipophilic nucleotide analog formed by covalently linking 3-(hexdecyloxy)propan-1-ol to cidofovir (CDV), is being developed as a treatment for smallpox. CMX001 has dramatically increased potency versus CDV against all dsDNA viruses and, in contrast to CDV, is orally available and has shown no evidence of nephrotoxicity in healthy volunteers or severely ill transplant patients to date. Although smallpox has been eliminated from the environment, treatments are urgently being sought due to the risk of smallpox being used as a bioterrorism agent and for monkeypox virus, a zoonotic disease of Africa, and adverse reactions to smallpox virus vaccinations. In the absence of human cases of smallpox, new treatments must be tested for efficacy in animal models. Here we first review and discuss the rabbitpox virus (RPV) infection of New Zealand White rabbits as a model for smallpox to test the efficacy of CMX001 as a prophylactic and early disease antiviral. Our results should also be applicable to monkeypox virus infections and for treatment of adverse reactions to smallpox vaccination.

  8. Vaccinia virus outperforms a panel of other poxviruses as a potent oncolytic agent for the control of head and neck squamous cell carcinoma cell lines.

    Science.gov (United States)

    Nichols, Anthony C; Yoo, John; Um, Sung; Mundi, Neil; Palma, David A; Fung, Kevin; Macneil, S Danielle; Koropatnick, James; Mymryk, Joe S; Barrett, John W

    2014-01-01

    Head and neck squamous cell carcinoma (HNSCC) is the fifth most common cancer worldwide. Existing therapies for advanced tumors have high failure rates and can have severe consequences in terms of pain, disfigurement, and poor speech and swallowing function. New treatment strategies are needed to improve outcomes for patients suffering with this disease and oncolytic viruses represent a promising approach. We infected six well-characterized HNSCC cell lines (Cal27, Detroit562, FaDu, SCC4, SCC15, SCC25), with increasing doses of a panel of poxviruses (including myxoma, vaccinia, raccoonpox and tanapox viruses) modified to express green fluorescence protein to determine which virus was the most effective oncolytic agent in cell-based assays. While myxoma, raccoonpox and tanapox displayed differing efficacy in the panel of cell lines, vaccinia virus was the most potent of the tested poxviruses and was highly effective in controlling cell growth in all cell lines. Oncolytic poxviruses, particularly vaccinia virus, were effective in killing HNSCC in vitro and hold promise as potential treatments for patients with HNSCC. Copyright © 2013 S. Karger AG, Basel.

  9. Viruses as the causative agent related to 'dampness' and the missing link between allergen exposure and onset of allergic disease

    DEFF Research Database (Denmark)

    Hersoug, Lars-Georg

    2005-01-01

    concentration and symptoms indicate a missing link between allergen exposure and onset of asthma. Respiratory viruses have been identified in up to 85% cases of asthma or exacerbations of asthma. The missing link between respiratory diseases and humid indoor climates could therefore be attributed to viruses....... The infectious effectiveness of respiratory viruses depends strongly on the environment where the viruses are spread. For respiratory viruses, survival and infectivity are dependent on temperature and relative humidity. A direct link between virus-induced inflammation and the asthmatogenic process has been...... proposed. Therefore, a more effective spreading of viral infections in damp indoor climates is likely to represent the main cause for the increased prevalence of asthma in these environments. Moreover, the incidence of viral infections is higher in patients with asthma compared with that in control...

  10. Causality in Europeanization Research

    DEFF Research Database (Denmark)

    Lynggaard, Kennet

    2012-01-01

    to develop discursive institutional analytical frameworks and something that comes close to the formulation of hypothesis on the effects of European Union (EU) policies and institutions on domestic change. Even if these efforts so far do not necessarily amount to substantive theories or claims of causality...

  11. Understanding Causal Coherence Relations

    NARCIS (Netherlands)

    Mulder, G.

    2008-01-01

    The research reported in this dissertation focuses on the cognitive processes and representations involved in understanding causal coherence relations in text. Coherence relations are the meaning relations between the information units in the text, such as Cause-Consequence. These relations can be

  12. Explaining through causal mechanisms

    NARCIS (Netherlands)

    Biesbroek, Robbert; Dupuis, Johann; Wellstead, Adam

    2017-01-01

    This paper synthesizes and builds on recent critiques of the resilience literature; namely that the field has largely been unsuccessful in capturing the complexity of governance processes, in particular cause–effects relationships. We demonstrate that absence of a causal model is reflected in the

  13. Twin Paradox and Causality

    OpenAIRE

    Grandou, T.; Rubin, J.L.

    2007-01-01

    After pointing out the historical avatar at the origin of a would be twin or clock paradox, we argue that, at least on a local scale, the (re-qualified) paradox is but a necessary consequence of the sole principle of causality.

  14. Optimal causal inference: estimating stored information and approximating causal architecture.

    Science.gov (United States)

    Still, Susanne; Crutchfield, James P; Ellison, Christopher J

    2010-09-01

    We introduce an approach to inferring the causal architecture of stochastic dynamical systems that extends rate-distortion theory to use causal shielding--a natural principle of learning. We study two distinct cases of causal inference: optimal causal filtering and optimal causal estimation. Filtering corresponds to the ideal case in which the probability distribution of measurement sequences is known, giving a principled method to approximate a system's causal structure at a desired level of representation. We show that in the limit in which a model-complexity constraint is relaxed, filtering finds the exact causal architecture of a stochastic dynamical system, known as the causal-state partition. From this, one can estimate the amount of historical information the process stores. More generally, causal filtering finds a graded model-complexity hierarchy of approximations to the causal architecture. Abrupt changes in the hierarchy, as a function of approximation, capture distinct scales of structural organization. For nonideal cases with finite data, we show how the correct number of the underlying causal states can be found by optimal causal estimation. A previously derived model-complexity control term allows us to correct for the effect of statistical fluctuations in probability estimates and thereby avoid overfitting.

  15. Inhibition of cell-to-cell transmission of human T-cell lymphotropic virus type 1 in vitro by carbohydrate-binding agents.

    Science.gov (United States)

    Balestrieri, Emanuela; Ascolani, Arianna; Igarashi, Yasuhiro; Oki, Toshikazu; Mastino, Antonio; Balzarini, Jan; Macchi, Beatrice

    2008-08-01

    Peripheral blood mononuclear cells (PBMCs) from healthy individuals can be infected by human T-lymphotropic virus type 1 (HTLV-1) upon cocultivation of the PBMCs with irradiated HTLV-1-transformed human MT-2 cells. This model system closely mimics HTLV-1 transmission through cell-to-cell contact. Carbohydrate-binding agents (CBAs) such as the alpha(1,3)/alpha(1,6)mannose-specific Hippeastrum hybrid agglutinin and the GlcNAc-specific Urtica dioica agglutinin, and also the small, nonpeptidic alpha(1,2)-mannose-specific antibiotic pradimicin A, were able to efficiently prevent cell-to-cell HTLV-1 transmission at nontoxic concentrations, as evidenced by the lack of appearance of virus-specific mRNA and of the viral protein Tax in the acceptor cells. Consistently, antivirally active doses of CBAs fully prevented HTLV-1-induced stimulation of PBMC growth. The inhibitory effects of CBAs on HTLV-1 transmission were also evident when HTLV-1-infected C5MJ cells were used in place of MT-2 cells as a virus donor cell line. The anti-HTLV-1 properties of the CBAs highlight the importance of the envelope glycans in events underlying HTLV-1 passage from cell to cell and indicate that CBAs should be further investigated for their potential to prevent HTLV-1 infection, including mother-to-child virus transmission by cell-to-cell contact through breast milk feeding.

  16. On the need to assess cancer risk in populations environmentally and occupationally exposed to virus and chemical agents in developing countries

    Directory of Open Access Journals (Sweden)

    Franco Netto Guilherme

    1998-01-01

    Full Text Available Evidence exists that exposure to poultry oncogenic viruses may produce elevated cancer mortality in human populations, particularly excesses of cancer of lung and excesses of cancer of lymphopoietic tissues. To date, this potential risk is unknown in populations from the developing countries. This paper suggests the need to assess cancer risk in populations of developing countries with reported environmental exposure to chicken meat products and eggs; the need to assess risk of cancer in populations inoculated with vaccines from infected chicken embryos; and the need to assess risk of cancer in occupational populations highly exposed to poultry oncogenic viruses, and with potential concurrent exposure to chemical agents known or suspected to be carcinogens.

  17. On the need to assess cancer risk in populations environmentally and occupationally exposed to virus and chemical agents in developing countries

    Directory of Open Access Journals (Sweden)

    Guilherme Franco Netto

    Full Text Available Evidence exists that exposure to poultry oncogenic viruses may produce elevated cancer mortality in human populations, particularly excesses of cancer of lung and excesses of cancer of lymphopoietic tissues. To date, this potential risk is unknown in populations from the developing countries. This paper suggests the need to assess cancer risk in populations of developing countries with reported environmental exposure to chicken meat products and eggs; the need to assess risk of cancer in populations inoculated with vaccines from infected chicken embryos; and the need to assess risk of cancer in occupational populations highly exposed to poultry oncogenic viruses, and with potential concurrent exposure to chemical agents known or suspected to be carcinogens.

  18. Information causality and noisy computations

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Li-Yi [Department of Physics, Chung Yuan Christian University, Chung-li 32023, Taiwan (China); Yu, I-Ching; Lin, Feng-Li [Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan (China)

    2011-10-15

    We reformulate the information causality in a more general framework by adopting the results of signal propagation and computation in a noisy circuit. In our framework, the information causality leads to a broad class of Tsirelson inequalities. This fact allows us to subject information causality to experimental scrutiny. A no-go theorem for reliable nonlocal computation is also derived. Information causality prevents any physical circuit from performing reliable computations.

  19. Association between respiratory infections in early life and later asthma is independent of virus type

    DEFF Research Database (Denmark)

    Bønnelykke, Klaus; Vissing, Nadja Hawwa; Sevelsted, Astrid

    2015-01-01

    BACKGROUND: Lower respiratory tract infections in the first years of life are associated with later asthma, and this observation has led to a focus on the potential causal role of specific respiratory viruses, such as rhinoviruses and respiratory syncytial virus, in asthma development. However...... (respiratory syncytial virus, rhinoviruses, other picornaviruses, coronaviruses 229E and OC43, parainfluenza viruses 1-3, influenza viruses AH1, AH3, and B, human metapneumovirus, adenoviruses, and bocavirus) and 3 pathogenic airway bacteria (Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella......, many respiratory viruses and bacteria trigger similar respiratory symptoms and it is possible that the important risk factors for asthma are the underlying susceptibility to infection and the exaggerated reaction to such triggers rather than the particular triggering agent. OBJECTIVE: We sought...

  20. The kuru infectious agent is a unique geographic isolate distinct from Creutzfeldt–Jakob disease and scrapie agents

    Science.gov (United States)

    Manuelidis, Laura; Chakrabarty, Trisha; Miyazawa, Kohtaro; Nduom, Nana-Aba; Emmerling, Kaitlin

    2009-01-01

    Human sporadic Creutzfeldt–Jakob disease (sCJD), endemic sheep scrapie, and epidemic bovine spongiform encephalopathy (BSE) are caused by a related group of infectious agents. The new U.K. BSE agent spread to many species, including humans, and clarifying the origin, specificity, virulence, and diversity of these agents is critical, particularly because infected humans do not develop disease for many years. As with viruses, transmissible spongiform encephalopathy (TSE) agents can adapt to new species and become more virulent yet maintain fundamentally unique and stable identities. To make agent differences manifest, one must keep the host genotype constant. Many TSE agents have revealed their independent identities in normal mice. We transmitted primate kuru, a TSE once epidemic in New Guinea, to mice expressing normal and ≈8-fold higher levels of murine prion protein (PrP). High levels of murine PrP did not prevent infection but instead shortened incubation time, as would be expected for a viral receptor. Sporadic CJD and BSE agents and representative scrapie agents were clearly different from kuru in incubation time, brain neuropathology, and lymphoreticular involvement. Many TSE agents can infect monotypic cultured GT1 cells, and unlike sporadic CJD isolates, kuru rapidly and stably infected these cells. The geographic independence of the kuru agent provides additional reasons to explore causal environmental pathogens in these infectious neurodegenerative diseases. PMID:19633190

  1. The kuru infectious agent is a unique geographic isolate distinct from Creutzfeldt-Jakob disease and scrapie agents.

    Science.gov (United States)

    Manuelidis, Laura; Chakrabarty, Trisha; Miyazawa, Kohtaro; Nduom, Nana-Aba; Emmerling, Kaitlin

    2009-08-11

    Human sporadic Creutzfeldt-Jakob disease (sCJD), endemic sheep scrapie, and epidemic bovine spongiform encephalopathy (BSE) are caused by a related group of infectious agents. The new U.K. BSE agent spread to many species, including humans, and clarifying the origin, specificity, virulence, and diversity of these agents is critical, particularly because infected humans do not develop disease for many years. As with viruses, transmissible spongiform encephalopathy (TSE) agents can adapt to new species and become more virulent yet maintain fundamentally unique and stable identities. To make agent differences manifest, one must keep the host genotype constant. Many TSE agents have revealed their independent identities in normal mice. We transmitted primate kuru, a TSE once epidemic in New Guinea, to mice expressing normal and approximately 8-fold higher levels of murine prion protein (PrP). High levels of murine PrP did not prevent infection but instead shortened incubation time, as would be expected for a viral receptor. Sporadic CJD and BSE agents and representative scrapie agents were clearly different from kuru in incubation time, brain neuropathology, and lymphoreticular involvement. Many TSE agents can infect monotypic cultured GT1 cells, and unlike sporadic CJD isolates, kuru rapidly and stably infected these cells. The geographic independence of the kuru agent provides additional reasons to explore causal environmental pathogens in these infectious neurodegenerative diseases.

  2. Descripción del ingreso del virus de la rabia desde la periferia hasta la médula espinal en un modelo de ratón adulto

    Directory of Open Access Journals (Sweden)

    Marlén Martínez Gutiérrez

    2005-03-01

    Full Text Available El virus de rabia (VR es el agente causal de la enfermedad conocida como hidrofobia.  Una vez inoculado en la periferia, el VR es capturado y transportado por las terminaciones sensoriales y/o motoras presentes en el sitio de la inoculación, hasta el sistema nervioso.

  3. Development and validation of a real-time two-step RT-qPCR TaqMan(®) assay for quantitation of Sacbrood virus (SBV) and its application to a field survey of symptomatic honey bee colonies

    DEFF Research Database (Denmark)

    Blanchard, Philippe; Guillot, Sylvain; Antùnez, Karina

    2014-01-01

    Sacbrood virus (SBV) is the causal agent of a disease of honey bee larvae, resulting in failure to pupate and causing death. The typical clinical symptom of SBV is an accumulation of SBV-rich fluid in swollen sub-cuticular pouches, forming the characteristic fluid-filled sac that gives its name t...

  4. Revisiting Causality in Markov Chains

    CERN Document Server

    Shojaee, Abbas

    2016-01-01

    Identifying causal relationships is a key premise of scientific research. The growth of observational data in different disciplines along with the availability of machine learning methods offers the possibility of using an empirical approach to identifying potential causal relationships, to deepen our understandings of causal behavior and to build theories accordingly. Conventional methods of causality inference from observational data require a considerable length of time series data to capture cause-effect relationship. We find that potential causal relationships can be inferred from the composition of one step transition rates to and from an event. Also known as Markov chain, one step transition rates are a commonly available resource in different scientific disciplines. Here we introduce a simple, effective and computationally efficient method that we termed 'Causality Inference using Composition of Transitions CICT' to reveal causal structure with high accuracy. We characterize the differences in causes,...

  5. Quantum information causality.

    Science.gov (United States)

    Pitalúa-García, Damián

    2013-05-24

    How much information can a transmitted physical system fundamentally communicate? We introduce the principle of quantum information causality, which states the maximum amount of quantum information that a quantum system can communicate as a function of its dimension, independently of any previously shared quantum physical resources. We present a new quantum information task, whose success probability is upper bounded by the new principle, and show that an optimal strategy to perform it combines the quantum teleportation and superdense coding protocols with a task that has classical inputs.

  6. Causal Entropic Forces

    Science.gov (United States)

    Wissner-Gross, A. D.; Freer, C. E.

    2013-04-01

    Recent advances in fields ranging from cosmology to computer science have hinted at a possible deep connection between intelligence and entropy maximization, but no formal physical relationship between them has yet been established. Here, we explicitly propose a first step toward such a relationship in the form of a causal generalization of entropic forces that we find can cause two defining behaviors of the human “cognitive niche”—tool use and social cooperation—to spontaneously emerge in simple physical systems. Our results suggest a potentially general thermodynamic model of adaptive behavior as a nonequilibrium process in open systems.

  7. Entropy of Causal Horizons

    CERN Document Server

    Howard, Eric M

    2016-01-01

    We analyze spacetimes with horizons and study the thermodynamic aspects of causal horizons, suggesting that the resemblance between gravitational and thermodynamic systems has a deeper quantum mechanical origin. We find that the observer dependence of such horizons is a direct consequence of associating a temperature and entropy to a spacetime. The geometrical picture of a horizon acting as a one-way membrane for information flow can be accepted as a natural interpretation of assigning a quantum field theory to a spacetime with boundary, ultimately leading to a close connection with thermodynamics.

  8. Direct-Acting Antiviral Agents for the Hepatitis C Virus-Infected Chronic Kidney Disease Population: The Dawn of a New Era.

    Science.gov (United States)

    Kusnir, Juan; Roth, David

    2016-01-01

    The introduction of direct-acting antiviral (DAA) agents with cure rates of >90% has changed the treatment of hepatitis C virus (HCV) in dramatic fashion. An extensive literature has documented the efficacy of these agents in the general population; however, patients with chronic kidney disease have been largely excluded from these trials. Recently published studies conducted in patients with chronic kidney disease are now demonstrating that the DAAs will also offer safe and effective therapy for the HCV-infected patient with CKD as well. As effective treatment protocols are offered to larger numbers of HCV-infected CKD patients, the decision regarding when is the most opportune time to treat, especially for the patient being considered for kidney transplantation will become of greater significance. Nephrologists will need to take a lead in these clinical decisions as obtaining a sustained viral response prior to transplant will effectively eliminate the patient as a candidate to receive a kidney from a hepatitis C virus-positive donor and the benefit of the shorter waiting times accompanying this strategy. © 2016 Wiley Periodicals, Inc.

  9. Antiviral agents in hepatitis B virus transfected cell lines: Inhibitory and cytotoxic effect related to time of treatment

    NARCIS (Netherlands)

    J. Kruining; R.A. Heijtink; S.W. Schalm (Solko)

    1995-01-01

    textabstractThe antiviral and cytotoxic effects of ara-arabinoside monophosphate, 2′,3′, dideoxy-cytidine, ganciclovir, 9-2(-phosphonylmethoxyethyl) adenine, 2′,3′-dideoxy-3′-thiacytidine and recombinant interferon-alpha were studied using two human hepatitis B virus transfected hepatoma cell lines,

  10. Short communication. First report of Eggplant mottled dwarf virus in China rose in southern Spain

    OpenAIRE

    Parrella, G.; De Stradis, A.; Greco, B.; Villanueva, F.; I. M. Fortes; Navas-Castillo, J

    2013-01-01

    Eggplant mottled dwarf virus (EMDV, genus Nucleorhabdovirus, family Rhabdoviridae) is transmitted in nature by leafhoppers and its natural host range includes vegetable crops (eggplant, tomato, potato, pepper), ornamentals (pittosporum, honeysuckle, pelargonium) and wild plants (caper, Solanum nigrum). The prevalence of infections is generally very low. EMDV has been demonstrated to be the causal agent of a vein yellowing disease of China rose (Hibiscus rosa-sinensis) in southern Italy. In th...

  11. Causal inference based on counterfactuals

    Directory of Open Access Journals (Sweden)

    Höfler M

    2005-09-01

    Full Text Available Abstract Background The counterfactual or potential outcome model has become increasingly standard for causal inference in epidemiological and medical studies. Discussion This paper provides an overview on the counterfactual and related approaches. A variety of conceptual as well as practical issues when estimating causal effects are reviewed. These include causal interactions, imperfect experiments, adjustment for confounding, time-varying exposures, competing risks and the probability of causation. It is argued that the counterfactual model of causal effects captures the main aspects of causality in health sciences and relates to many statistical procedures. Summary Counterfactuals are the basis of causal inference in medicine and epidemiology. Nevertheless, the estimation of counterfactual differences pose several difficulties, primarily in observational studies. These problems, however, reflect fundamental barriers only when learning from observations, and this does not invalidate the counterfactual concept.

  12. Nanobody-mediated resistance to Grapevine fanleaf virus in plants.

    Science.gov (United States)

    Hemmer, Caroline; Djennane, Samia; Ackerer, Léa; Hleibieh, Kamal; Marmonier, Aurélie; Gersch, Sophie; Garcia, Shahinez; Vigne, Emmanuelle; Komar, Véronique; Perrin, Mireille; Gertz, Claude; Belval, Lorène; Berthold, François; Monsion, Baptiste; Schmitt-Keichinger, Corinne; Lemaire, Olivier; Lorber, Bernard; Gutiérrez, Carlos; Muyldermans, Serge; Demangeat, Gérard; Ritzenthaler, Christophe

    2017-08-10

    Since their discovery, single-domain antigen-binding fragments of camelid-derived heavy-chain-only antibodies, also known as nanobodies (Nbs), have proven to be of outstanding interest as therapeutics against human diseases and pathogens including viruses, but their use against phytopathogens remains limited. Many plant viruses including Grapevine fanleaf virus (GFLV), a nematode-transmitted icosahedral virus and causal agent of fanleaf degenerative disease, have worldwide distribution and huge burden on crop yields representing billions of US dollars of losses annually, yet solutions to combat these viruses are often limited or inefficient. Here, we identified a Nb specific to GFLV that confers strong resistance to GFLV upon stable expression in the model plant Nicotiana benthamiana and also in grapevine rootstock, the natural host of the virus. We showed that resistance was effective against a broad range of GFLV isolates independently of the inoculation method including upon nematode transmission but not against its close relative, Arabis mosaic virus. We also demonstrated that virus neutralization occurs at an early step of the virus life cycle, prior to cell-to-cell movement. Our findings will not only be instrumental to confer resistance to GFLV in grapevine, but more generally they pave the way for the generation of novel antiviral strategies in plants based on Nbs. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  13. Causality & holographic entanglement entropy

    Energy Technology Data Exchange (ETDEWEB)

    Headrick, Matthew [Martin Fisher School of Physics, Brandeis University, MS 057, 415 South Street, Waltham, MA 02454 (United States); Hubeny, Veronika E. [Centre for Particle Theory & Department of Mathematical Sciences,Science Laboratories, South Road, Durham DH1 3LE (United Kingdom); Lawrence, Albion [Martin Fisher School of Physics, Brandeis University, MS 057, 415 South Street, Waltham, MA 02454 (United States); Rangamani, Mukund [Centre for Particle Theory & Department of Mathematical Sciences,Science Laboratories, South Road, Durham DH1 3LE (United Kingdom)

    2014-12-29

    We identify conditions for the entanglement entropy as a function of spatial region to be compatible with causality in an arbitrary relativistic quantum field theory. We then prove that the covariant holographic entanglement entropy prescription (which relates entanglement entropy of a given spatial region on the boundary to the area of a certain extremal surface in the bulk) obeys these conditions, as long as the bulk obeys the null energy condition. While necessary for the validity of the prescription, this consistency requirement is quite nontrivial from the bulk standpoint, and therefore provides important additional evidence for the prescription. In the process, we introduce a codimension-zero bulk region, named the entanglement wedge, naturally associated with the given boundary spatial region. We propose that the entanglement wedge is the most natural bulk region corresponding to the boundary reduced density matrix.

  14. The Cosmic Causal Mass

    Directory of Open Access Journals (Sweden)

    Simen Braeck

    2017-04-01

    Full Text Available In order to provide a better understanding of rotating universe models, and in particular the Gödel universe, we discuss the relationship between cosmic rotation and perfect inertial dragging. In this connection, the concept of causal mass is defined in a cosmological context, and discussed in relation to the cosmic inertial dragging effect. Then, we calculate the mass inside the particle horizon of the flat ΛCDM-model integrated along the past light cone. The calculation shows that the Schwarzschild radius of this mass is around three times the radius of the particle horizon. This indicates that there is close to perfect inertial dragging in our universe. Hence, the calculation provides an explanation for the observation that the swinging plane of a Foucault pendulum follows the stars.

  15. The challenge of treating hepatitis C virus-associated cryoglobulinemic vasculitis in the era of anti-CD20 monoclonal antibodies and direct antiviral agents.

    Science.gov (United States)

    Roccatello, Dario; Sciascia, Savino; Rossi, Daniela; Solfietti, Laura; Fenoglio, Roberta; Menegatti, Elisa; Baldovino, Simone

    2017-06-20

    Mixed cryoglobulinemia syndrome (MC) is a systemic vasculitis involving kidneys, joints, skin, and peripheral nerves. While many autoimmune, lymphoproliferative, and neoplastic disorders have been associated with this disorder, hepatitis C virus (HCV) is known to be the etiologic agent in the majority of patients. Therefore, clinical research has focused on anti-viral drugs and, more recently, on the new, highly potent Direct-acting Antiviral Agents (DAAs). These drugs assure sustained virologic response (SVR) rates >90%. Nevertheless, data on their efficacy in patients with HCV-associated cryoglobulinemic vasculitis are disappointing, possibly due to the inability of the drugs to suppress the immune-mediated process once it has been triggered.Despite the potential risk of exacerbation of the infection, immunosuppression has traditionally been regarded as the first-line intervention in cryoglobulinemic vasculitis, especially if renal involvement is severe. Biologic agents have raised hopes for more manageable therapeutic approaches, and Rituximab (RTX), an anti CD20 monoclonal antibody, is the most widely used biologic drug. It has proved to be safer than conventional immunosuppressants, thus substantially changing the natural history of HCV-associated cryoglobulinemic vasculitis by providing long-term remission, especially with intensive regimens.The present review focuses on the new therapeutic opportunities offered by the combination of biological drugs, mainly Rituximab, with DAAs.

  16. Causality Statistical Perspectives and Applications

    CERN Document Server

    Berzuini, Carlo; Bernardinell, Luisa

    2012-01-01

    A state of the art volume on statistical causality Causality: Statistical Perspectives and Applications presents a wide-ranging collection of seminal contributions by renowned experts in the field, providing a thorough treatment of all aspects of statistical causality. It covers the various formalisms in current use, methods for applying them to specific problems, and the special requirements of a range of examples from medicine, biology and economics to political science. This book:Provides a clear account and comparison of formal languages, concepts and models for statistical causality. Addr

  17. Genetic diversity-independent neutralization of pandemic viruses (e.g. HIV), potentially pandemic (e.g. H5N1 strain of influenza) and carcinogenic (e.g. HBV and HCV) viruses and possible agents of bioterrorism (variola) by enveloped virus neutralizing compounds (EVNCs).

    Science.gov (United States)

    Kotwal, Girish J

    2008-06-06

    Genetic diversity and hypermutation contribute to difficulties in developing a vaccine against viruses like HIV and influenza. There are currently no known immune correlates of protection against HIV. This has made the development of a vaccine against HIV that would provide sterilizing immunity in the near future an impossible task. The abandonment of a recent AIDS vaccine human trial due to a failure to elicit a protective sterilising immune response confirms that empirical attempts to develop a vaccine may result in failures. Also the difficulty in predicting the next pandemic strain of influenza may make it difficult to respond rapidly should there be an outbreak. Therefore, it is time to explore broad spectrum agents that can target either the lipid portion of the envelope or the sugar moieties of the glycoproteins or the rafts (regions within viral and cell envelopes where a higher concentration of the glycoproteins exist). Broad spectrum agents that can serve as disrafters or neutralize the viral infectivity by binding to the envelope lipid or sugar moieties will not be affected by the vagaries of hypermutation of surface antigens. This is because the post-translation modification is a host function. Presented here is a review of recently reported agents present in pomegranate juice (polyphenols, beta-sitosterol, sugars and ellagic acid) and fulvic acid, described here as the envelope virus neutralising compounds (EVNCs) and complex molecules like lectins and mucins. Pomegranate juice was previously reported to inactivate HIV and further shown by our group to inactivate influenza, herpes viruses and poxviruses. A formulation consisting of fulvic acid, a complex mixture of compounds was previously reported to render vaccinia virus, HIV and SARS virus non-infectious. Recently, both fulvic acid and pomegranate juice have been shown to inactivate genetically diverse strains of influenza including H5N1, further confirming the broad spectrum nature of these agents

  18. Antisense Treatments for Biothreat Agents

    National Research Council Canada - National Science Library

    Warfield, Kelly L; Panchal, Rekha G; Aman, M J; Bavari, Sina

    2006-01-01

    ... a variety of pathogens in cell culture studies and nonhuman primate models of infection. For these reasons, antisense technologies are being pursued as treatments against biothreat agents such as Ebola virus, dengue virus and Bacillus anthracis...

  19. The evidence of bacilliform virus a causative agent of white spot syndrome of white shrimp Penaeus merguiensis

    Directory of Open Access Journals (Sweden)

    Hari Suprapto

    2003-06-01

    Full Text Available The rod-shape virus particles were found in the hyperthrophied nucleus and cytoplasm of diseased white shrimpPenaeus merguiensis naturally infected by White spot syndrome (WSBV. In natural infection cumulative mortality of shrimp werevery high, 95% of population were dead in 3-7 days, and 5% of shrimp population survived. The disease was outbreak in intensiveculture farms used the closed circulation sea water system. Others crustacean such as crabs and bentatos were not infected by WSBVat time of sampling. The virus particle were rod-shape ranging from 78 ± 10 nm in diameter and 280 ± 10 nm in length. The pathogenicbacteria mainly dominated by genus Vibrio sp were isolated from shrimp.

  20. SAXS characterization of genetically engineered tobacco mosaic virus nanorods coated with palladium in the absence of external reducing agents.

    Science.gov (United States)

    Freer, Alexander S; Guarnaccio, Lucas; Wafford, Kristin; Smith, Johanna; Steilberg, Jayne; Culver, James N; Harris, Michael T

    2013-02-15

    Genetic modifications of the tobacco mosaic virus (TMV) coat proteins allow for an increase in the selective deposition and controlled growth of different metals onto the surface of the virus, making it an ideal biotemplate for metal nanowire formation. In the current process, TMV2Cys is coated sequentially with multiple uniform layers of palladium metal in aqueous solution under very mild conditions. Palladium nanowires of 300 nm in length and 30-40 nm in diameter have been created with this process. Transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS) are used to characterize the thickness and uniformity of the metal surface. The TEM and SAXS results confirm that the final thickness of the palladium nanowires is controllable by varying the number of coating layers or the initial palladium concentration. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Expert Causal Reasoning and Explanation.

    Science.gov (United States)

    Kuipers, Benjamin

    The relationship between cognitive psychologists and researchers in artificial intelligence carries substantial benefits for both. An ongoing investigation in causal reasoning in medical problem solving systems illustrates this interaction. This paper traces a dialectic of sorts in which three different types of causal resaoning for medical…

  2. Introduction to causal dynamical triangulations

    DEFF Research Database (Denmark)

    Görlich, Andrzej

    2013-01-01

    The method of causal dynamical triangulations is a non-perturbative and background-independent approach to quantum theory of gravity. In this review we present recent results obtained within the four dimensional model of causal dynamical triangulations. We describe the phase structure of the mode...

  3. Causal Inference and Developmental Psychology

    Science.gov (United States)

    Foster, E. Michael

    2010-01-01

    Causal inference is of central importance to developmental psychology. Many key questions in the field revolve around improving the lives of children and their families. These include identifying risk factors that if manipulated in some way would foster child development. Such a task inherently involves causal inference: One wants to know whether…

  4. Re-thinking local causality

    NARCIS (Netherlands)

    Friederich, Simon

    There is widespread belief in a tension between quantum theory and special relativity, motivated by the idea that quantum theory violates J. S. Bell's criterion of local causality, which is meant to implement the causal structure of relativistic space-time. This paper argues that if one takes the

  5. Paradoxical Behavior of Granger Causality

    Science.gov (United States)

    Witt, Annette; Battaglia, Demian; Gail, Alexander

    2013-03-01

    Granger causality is a standard tool for the description of directed interaction of network components and is popular in many scientific fields including econometrics, neuroscience and climate science. For time series that can be modeled as bivariate auto-regressive processes we analytically derive an expression for spectrally decomposed Granger Causality (SDGC) and show that this quantity depends only on two out of four groups of model parameters. Then we present examples of such processes whose SDGC expose paradoxical behavior in the sense that causality is high for frequency ranges with low spectral power. For avoiding misinterpretations of Granger causality analysis we propose to complement it by partial spectral analysis. Our findings are illustrated by an example from brain electrophysiology. Finally, we draw implications for the conventional definition of Granger causality. Bernstein Center for Computational Neuroscience Goettingen

  6. Clear message for causality

    Energy Technology Data Exchange (ETDEWEB)

    Steinberg, Aephraim M. [Institute for Experimental Physics, University of Vienna, Vienna (Austria)

    2003-12-01

    Experiment confirms that information cannot be transmitted faster than the speed of light. Ever since Einstein stated that nothing can travel faster than light, physicists have delighted in finding exceptions. One after another, observations of such 'superluminal' propagation have been made. However, while some image or pattern- such as the motion of a spotlight projected on a distant wall - might have appeared to travel faster than light, it seemed that there was no way to use the superluminal effect to transmit energy or information. In recent years, the superluminal propagation of light pulses through certain media has led to renewed controversy. In 1995, for example, Guenther Nimtz of the University of Cologne encoded Mozart's 40th Symphony on a microwave beam, which he claimed to have transmitted at a speed faster than light. Others maintain that such a violation of Einstein's speed limit would wreak havoc on our most fundamental ideas about causality, allowing an effect to precede its cause. Relativity teaches us that sending a signal faster than light would be equivalent to sending it backwards in time. (U.K.)

  7. Multiscale Granger causality

    Science.gov (United States)

    Faes, Luca; Nollo, Giandomenico; Stramaglia, Sebastiano; Marinazzo, Daniele

    2017-10-01

    In the study of complex physical and biological systems represented by multivariate stochastic processes, an issue of great relevance is the description of the system dynamics spanning multiple temporal scales. While methods to assess the dynamic complexity of individual processes at different time scales are well established, multiscale analysis of directed interactions has never been formalized theoretically, and empirical evaluations are complicated by practical issues such as filtering and downsampling. Here we extend the very popular measure of Granger causality (GC), a prominent tool for assessing directed lagged interactions between joint processes, to quantify information transfer across multiple time scales. We show that the multiscale processing of a vector autoregressive (AR) process introduces a moving average (MA) component, and describe how to represent the resulting ARMA process using state space (SS) models and to combine the SS model parameters for computing exact GC values at arbitrarily large time scales. We exploit the theoretical formulation to identify peculiar features of multiscale GC in basic AR processes, and demonstrate with numerical simulations the much larger estimation accuracy of the SS approach compared to pure AR modeling of filtered and downsampled data. The improved computational reliability is exploited to disclose meaningful multiscale patterns of information transfer between global temperature and carbon dioxide concentration time series, both in paleoclimate and in recent years.

  8. History, causality, and sexology.

    Science.gov (United States)

    Money, John

    2003-08-01

    In 1896, Krafft-Ebing published Psychopathia Sexualis. Popularly defined as hereditary weakness or taintedness in the family pedigree, degeneracy was called upon as a causal explanation for perversions of the sexual instinct. Although Krafft-Ebing accepted Karl Ulrichs proposal that homosexuality could be innate and probably located in the brain, he paid little attention to neuropathological sexology. Alfred Binet challenged Krafft-Ebing's orthodoxy by explaining fetishism in terms of associative learning, to which Krafft-Ebing's response was that only those with a hereditary taint would be vulnerable. Thus did the venerable nature-nurture antithesis maintain its rhetoric, even to the present day. Krafft-Ebing died too soon to meet the Freudian challenge of endopsychic determinism, and too soon also to encounter the idea of a developmental multivariate outcome of what I have termed the lovemap. Like other brain maps, for example the languagemap, the lovemap requires an intact human brain in which to develop. The personalized content of the lovemap has access to the brain by way of the special senses.

  9. Causal Rasch models

    Directory of Open Access Journals (Sweden)

    A. Jackson Stenner

    2013-08-01

    Full Text Available Rasch’s unidimensional models for measurement show how to connect object measures (e.g., reader abilities, measurement mechanisms (e.g., machine-generated cloze reading items, and observational outcomes (e.g., counts correct on reading instruments. Substantive theory shows what interventions or manipulations to the measurement mechanism can be traded off against a change to the object measure to hold the observed outcome constant. A Rasch model integrated with a substantive theory dictates the form and substance of permissible interventions. Rasch analysis, absent construct theory and an associated specification equation, is a black box in which understanding may be more illusory than not. Finally, the quantitative hypothesis can be tested by comparing theory-based trade-off relations with observed trade-off relations. Only quantitative variables (as measured support such trade-offs. Note that to test the quantitative hypothesis requires more than manipulation of the algebraic equivalencies in the Rasch model or descriptively fitting data to the model. A causal Rasch model involves experimental intervention/manipulation on either reader ability or text complexity or a conjoint intervention on both simultaneously to yield a successful prediction of the resultant observed outcome (count correct. We conjecture that when this type of manipulation is introduced for individual reader text encounters and model predictions are consistent with observations, the quantitative hypothesis is sustained.

  10. Bluetongue serotype 2 and 9 modified live vaccine viruses as causative agents of abortion in livestock: a retrospective analysis in Italy.

    Science.gov (United States)

    Savini, G; Lorusso, A; Paladini, C; Migliaccio, P; Di Gennaro, A; Di Provvido, A; Scacchia, M; Monaco, F

    2014-02-01

    The recent outbreak caused by Schmallenberg virus, which affected sheep, goats and cattle in Europe, highlighted the importance of having a robust surveillance plan capable of monitoring abortions and malformations in the livestock offspring. In this context, bluetongue viruses (BTVs) represented and represent one of the major threats to the European livestock industry. Aiming to improve the understanding on BTV cross placental transmission and serotype involvement, in this retrospective study foetal spleens and/or brains of 663 ovines, 429 bovines, 155 goats and 17 buffaloes were tested for the presence of BTV by virus isolation. BTV vaccine strains were isolated from 31 foetuses (2.4%; 95% CI: 1.7-3.4%): 24 (3.6%; 95% CI: 2.4-5.3%) from ovine foetal tissues; 6 (1.4%; 95% CI: 0.6-3.0%) from bovine foetal tissues and 1 (0.6%; 95% CI: 0.2-3.5%) from the spleen of a caprine foetus. All foetuses were from animals vaccinated with either BTV-2 or BTV-2, and BTV-9 modified live vaccines (MLVs) produced by Onderstepoort Biological Products (OBP), South Africa. Among the 31 isolated vaccine strains, serotype 9 (n = 28) was more frequently isolated (P < 0.05) than serotype 2 (n = 3). In two cases infectious vaccine strains were found in the foetal tissues 2 months after the vaccine administration. Other pathogens known to be causative agents of abortion in ruminants were not detected nor isolated. This study demonstrates, for the first time, that BTV-2 and BTV-9 vaccine strains are able to cross the placental barrier of sheep, cattle and goats. BTV-2 and BTV-9 vaccine strains are able to infect foetuses and cause abortions or malformations depending on the period of pregnancy at the time of vaccination. © 2012 Blackwell Verlag GmbH.

  11. Neural Correlates of Causal Power Judgments

    Directory of Open Access Journals (Sweden)

    Denise Dellarosa Cummins

    2014-12-01

    Full Text Available Causal inference is a fundamental component of cognition and perception. Probabilistic theories of causal judgment (most notably causal Bayes networks derive causal judgments using metrics that integrate contingency information. But human estimates typically diverge from these normative predictions. This is because human causal power judgments are typically strongly influenced by beliefs concerning underlying causal mechanisms, and because of the way knowledge is retrieved from human memory during the judgment process. Neuroimaging studies indicate that the brain distinguishes causal events from mere covariation, and between perceived and inferred causality. Areas involved in error prediction are also activated, implying automatic activation of possible exception cases during causal decision-making.

  12. Xanthomonas campestris pv. campestris race 1 is the main causal ...

    African Journals Online (AJOL)

    Severe outbreaks of bacterial black rot caused by Xanthomonas campestris pv. campestris (Xcc) were observed in Brassica production fields of Southern Mozambique. The causal agent of the disease in the Mahotas and Chòkwé districts was identified and characterised. In total, 83 Xanthomonas-like strains were isolated ...

  13. Clarity and causality needed in claims about Big Gods.

    Science.gov (United States)

    Watts, Joseph; Bulbulia, Joseph; Gray, Russell D; Atkinson, Quentin D

    2016-01-01

    We welcome Norenzayan et al.'s claim that the prosocial effects of beliefs in supernatural agents extend beyond Big Gods. To date, however, supporting evidence has focused on the Abrahamic Big God, making generalisations difficult. We discuss a recent study that highlights the need for clarity about the causal path by which supernatural beliefs affect the evolution of big societies.

  14. Antimicrobial Peptides Derived from Fusion Peptides of Influenza A Viruses, a Promising Approach to Designing Potent Antimicrobial Agents.

    Science.gov (United States)

    Wang, Jingyu; Zhong, Wenjing; Lin, Dongguo; Xia, Fan; Wu, Wenjiao; Zhang, Heyuan; Lv, Lin; Liu, Shuwen; He, Jian

    2015-10-01

    The emergence and dissemination of antibiotic-resistant bacterial pathogens have spurred the urgent need to develop novel antimicrobial agents with different mode of action. In this respect, we turned several fusogenic peptides (FPs) derived from the hemagglutinin glycoproteins (HAs) of IAV into potent antibacterials by replacing the negatively or neutrally charged residues of FPs with positively charged lysines. Their antibacterial activities were evaluated by testing the MICs against a panel of bacterial strains including S. aureus, S. mutans, P. aeruginosa, and E. coli. The results showed that peptides HA-FP-1, HA-FP-2-1, and HA-FP-3-1 were effective against both Gram-positive and Gram-negative bacteria with MICs ranging from 1.9 to 16.0 μm, while the toxicities toward mammalian cells were low. In addition, the mode of action and the secondary structure of these peptides were also discussed. These data not only provide several potent peptides displaying promising potential in development as broad antimicrobial agents, but also present a useful strategy in designing new antimicrobial agents. © 2015 John Wiley & Sons A/S.

  15. Enhanced inactivation of avian influenza virus at -20°C by disinfectants supplemented with calcium chloride or other antifreeze agents.

    Science.gov (United States)

    Guan, Jiewen; Chan, Maria; Brooks, Brian W; Rohonczy, Elizabeth

    2015-10-01

    Avian influenza outbreaks have occurred during winter months, and effective disinfection of poultry premises at freezing temperatures is needed. The commercial disinfectants Virkon and Accel, supplemented with an antifreeze agent [propylene glycol (PG), methanol (MeOH), or calcium chloride (CaCl₂)], were evaluated for their effectiveness in killing avian influenza virus (AIV) at -20°C or 21°C. An AIV suspension was applied to stainless steel disks, air-dried, and covered with a disinfectant or antifreeze agent for 5 to 30 min. Virkon (2%) and Accel (6.25%) with 30% PG, 20% MeOH, or 20% CaCl₂ inactivated 6 log₁₀ AIV within 5 min at -20°C and 21°C. At these temperatures PG and MeOH alone did not kill AIV, but the 20% CaCl₂ solution alone inactivated 5 log10 AIV within 10 min. The results suggested that CaCl₂ is potentially useful to enhance the effectiveness of disinfection of poultry facilities after outbreaks of AIV infection in warm and cold seasons.

  16. Enhanced inactivation of avian influenza virus at −20°C by disinfectants supplemented with calcium chloride or other antifreeze agents

    Science.gov (United States)

    Guan, Jiewen; Chan, Maria; Brooks, Brian W.; Rohonczy, Elizabeth

    2015-01-01

    Avian influenza outbreaks have occurred during winter months, and effective disinfection of poultry premises at freezing temperatures is needed. The commercial disinfectants Virkon and Accel, supplemented with an antifreeze agent [propylene glycol (PG), methanol (MeOH), or calcium chloride (CaCl2)], were evaluated for their effectiveness in killing avian influenza virus (AIV) at −20°C or 21°C. An AIV suspension was applied to stainless steel disks, air-dried, and covered with a disinfectant or antifreeze agent for 5 to 30 min. Virkon (2%) and Accel (6.25%) with 30% PG, 20% MeOH, or 20% CaCl2 inactivated 6 log10 AIV within 5 min at −20°C and 21°C. At these temperatures PG and MeOH alone did not kill AIV, but the 20% CaCl2 solution alone inactivated 5 log10 AIV within 10 min. The results suggested that CaCl2 is potentially useful to enhance the effectiveness of disinfection of poultry facilities after outbreaks of AIV infection in warm and cold seasons. PMID:26424918

  17. Discrete causal theory emergent spacetime and the causal metric hypothesis

    CERN Document Server

    Dribus, Benjamin F

    2017-01-01

    This book evaluates and suggests potentially critical improvements to causal set theory, one of the best-motivated approaches to the outstanding problems of fundamental physics. Spacetime structure is of central importance to physics beyond general relativity and the standard model. The causal metric hypothesis treats causal relations as the basis of this structure. The book develops the consequences of this hypothesis under the assumption of a fundamental scale, with smooth spacetime geometry viewed as emergent. This approach resembles causal set theory, but differs in important ways; for example, the relative viewpoint, emphasizing relations between pairs of events, and relationships between pairs of histories, is central. The book culminates in a dynamical law for quantum spacetime, derived via generalized path summation.

  18. Infection with purified Piscine orthoreovirus demonstrates a causal relationship with heart and skeletal muscle inflammation in Atlantic salmon.

    Directory of Open Access Journals (Sweden)

    Øystein Wessel

    Full Text Available Viral diseases pose a significant threat to the productivity in aquaculture. Heart- and skeletal muscle inflammation (HSMI is an emerging disease in Atlantic salmon (Salmo salar farming. HSMI is associated with Piscine orthoreovirus (PRV infection, but PRV is ubiquitous in farmed Atlantic salmon and thus present also in apparently healthy individuals. This has brought speculations if additional etiological factors are required, and experiments focusing on the causal relationship between PRV and HSMI are highly warranted. A major bottleneck in PRV research has been the lack of cell lines that allow propagation of the virus. To bypass this, we propagated PRV in salmon, bled the fish at the peak of the infection, and purified virus particles from blood cells. Electron microscopy, western blot and high-throughput sequencing all verified the purity of the viral particles. Purified PRV particles were inoculated into naïve Atlantic salmon. The purified virus replicated in inoculated fish, spread to naïve cohabitants, and induced histopathological changes consistent with HSMI. PRV specific staining was demonstrated in the pathological lesions. A dose-dependent response was observed; a high dose of virus gave earlier peak of the viral load and development of histopathological changes compared to a lower dose, but no difference in the severity of the disease. The experiment demonstrated that PRV can be purified from blood cells, and that PRV is the etiological agent of HSMI in Atlantic salmon.

  19. Variant evidence of three genes of Potato vein yellow virus infecting Solanum tubersosum sp. using single strand conformational polymorphism.

    OpenAIRE

    CUBILLOS ABELLO, Karen Andrea; María Mónica GUZMÁN BARNEY

    2014-01-01

    Potato yellow vein virus (PYVV) with tripartite RNA (ss+) genome is classified as Crinivirus within the family Closteoviridae. PYVV is the causal agent of potato yellow vein disease (PYVD) with yield effect. Single strand conformational polymorphism (SSCP) was reported to estimate variability in eukaryotes and different viruses’ species. In this study, the molecular variability of PYVV was analyzed by SSCP patterns regarding three genes: major capsid protein (CP), minor capsid protein (CPm), ...

  20. Functional equations with causal operators

    CERN Document Server

    Corduneanu, C

    2003-01-01

    Functional equations encompass most of the equations used in applied science and engineering: ordinary differential equations, integral equations of the Volterra type, equations with delayed argument, and integro-differential equations of the Volterra type. The basic theory of functional equations includes functional differential equations with causal operators. Functional Equations with Causal Operators explains the connection between equations with causal operators and the classical types of functional equations encountered by mathematicians and engineers. It details the fundamentals of linear equations and stability theory and provides several applications and examples.

  1. Identification of Antiviral Agents Targeting Hepatitis B Virus Promoter from Extracts of Indonesian Marine Organisms by a Novel Cell-Based Screening Assay

    Directory of Open Access Journals (Sweden)

    Atsuya Yamashita

    2015-11-01

    Full Text Available The current treatments of chronic hepatitis B (CHB face a limited choice of vaccine, antibody and antiviral agents. The development of additional antiviral agents is still needed for improvement of CHB therapy. In this study, we established a screening system in order to identify compounds inhibiting the core promoter activity of hepatitis B virus (HBV. We prepared 80 extracts of marine organisms from the coral reefs of Indonesia and screened them by using this system. Eventually, two extracts showed high inhibitory activity (>95% and low cytotoxicity (66% to 77%. Solvent fractionation, column chromatography and NMR analysis revealed that 3,5-dibromo-2-(2,4-dibromophenoxy-phenol (compound 1 and 3,4,5-tribromo-2-(2,4-dibromophenoxy-phenol (compound 2, which are classified as polybrominated diphenyl ethers (PBDEs, were identified as anti-HBV agents in the extracts. Compounds 1 and 2 inhibited HBV core promoter activity as well as HBV production from HepG2.2.15.7 cells in a dose-dependent manner. The EC50 values of compounds 1 and 2 were 0.23 and 0.80 µM, respectively, while selectivity indexes of compound 1 and 2 were 18.2 and 12.8, respectively. These results suggest that our cell-based HBV core promoter assay system is useful to determine anti-HBV compounds, and that two PBDE compounds are expected to be candidates of lead compounds for the development of anti-HBV drugs.

  2. A quantitative structure-activity relationship study on a few series of anti-hepatitis C virus agents.

    Science.gov (United States)

    Varshney, Jonish; Sharma, Anjana; Gupta, Satya P

    2012-05-01

    A 2-Dimensional Quantitative Structure-Activity Relationship study has been performed on 2 series of hepatitis C virus (HCV) inhibitors, i.e., Isothiazoles and Thiazolones. In each case significant correlations are found between the anti-HCV potencies and some physicochemical, electronic and steric properties of the compounds, indicating that for the first series the activity is controlled by density and two indicator parameters (one for halogen and other for methyl), while for the second series density, Hammett constant and Kier's first order valence molecular connectivity index are important for anti-HCV activity. The validity of the correlation has been judged by leave-one-out jackknife procedure and predicting the activity of some test compounds. Using the correlations obtained, some new compounds of high potency have been predicted in each series.

  3. Causal inference in multisensory perception

    National Research Council Canada - National Science Library

    Körding, Konrad P; Beierholm, Ulrik; Ma, Wei Ji; Quartz, Steven; Tenenbaum, Joshua B; Shams, Ladan

    2007-01-01

    .... Here we use multisensory cue combination to study causal inference in perception. We formulate an ideal-observer model that infers whether two sensory cues originate from the same location and that also estimates their location...

  4. Competence and performance in causal learning

    National Research Council Canada - National Science Library

    Waldmann, Michael R; Walker, Jessica M

    2005-01-01

    .... This reduction of causal induction to associative learning implies that learners are insensitive to important characteristics of causality, such as the inherent directionality between causes and effects...

  5. O-GlcNAcylation of the Plum pox virus capsid protein catalyzed by SECRET AGENT: characterization of O-GlcNAc sites by electron transfer dissociation mass spectrometry.

    Science.gov (United States)

    Kim, Young-Cheon; Udeshi, Namrata D; Balsbaugh, Jeremy L; Shabanowitz, Jeffrey; Hunt, Donald F; Olszewski, Neil E

    2011-03-01

    The capsid protein of Plum pox virus (PPV-CP) is modified with O-linked β-N-acetylglucosamine (O-GlcNAc). In Arabidopsis thaliana this modification is made by an O-GlcNAc transferase named SECRET AGENT (SEC). Modification of PPV-CP by SEC is hypothesized to have a direct role in the infection process, because virus titer and rate of spread are reduced in SEC mutants. Previous studies used deletion mapping and site-directed mutagenesis to identify four O-GlcNAc sites on the capsid protein that are modified by Escherichia coli-expressed SEC. The infection process was not affected when two of these sites were mutated suggesting that O-GlcNAcylation of these sites does not have a significant role in the infection process or that a subset of the modifications is sufficient. Since it is possible that the mutational mapping approach missed or incorrectly identified O-GlcNAc sites, the modifications produced by E. coli-expressed SEC were characterized using mass spectrometry. O-GlcNAcylated peptides were enzymatically tagged with galactose, the products were enriched on immobilized Ricinus communis agglutinin I and sequenced by electron transfer dissociation (ETD) mass spectrometry. Five O-GlcNAc sites on PPV-CP were identified. Two of these sites were not identified in by the previous mutational mapping. In addition, one site previously predicted by mutation mapping was not detected, but modification of this site was not supported when the mutation mapping was repeated. This study suggests that mapping modification sites by ETD mass spectrometry is more comprehensive and accurate than mutational mapping.

  6. Causal attributions in Brazilian children's reasoning about health and illness

    Directory of Open Access Journals (Sweden)

    Boruchovitch Evely

    2000-01-01

    Full Text Available INTRODUCTION: At a time when a great number of diseases can be prevented by changing one's habits and life style, investigations have focused on understanding what adults and children believe to be desirable health practices and uncovering the factors associated with successful adherence to such practices. For these, causal attributions for health and illness were investigated among 96 Brazilian elementary school students. METHODS: Ninety six subjects, aged 6 to 14, were interviewed individually and their causal attributions were assessed through 14 true-false items (e.g. people stay well [healthy] because they are lucky. The relationship between the children's causal attributions and demographic characteristics were also examined. RESULTS: Overall, the results were consistent with previous researches. "Taking care of oneself" was considered the most important cause of good health. "Viruses and germs" and "lack of self-care" were the most selected causes of illness. Analyses revealed significant relationship between subjects' causal attribution and their age, school grade level, socioeconomic status and gender. CONCLUSIONS: The study findings suggest that there may be more cross-cultural similarities than differences in children's causal attributions for health and illness. Finding ways to help individuals engage in appropriate preventive-maintenance health practices without developing an exaggerated notion that the individuals can control their own health and illness is a challenge which remains to be addressed by further research.

  7. Pathogenicity of local isolate virus BHV-1 as the aetiological agent of Infectious Bovine Rhinotracheitis in Bali Cattle

    Directory of Open Access Journals (Sweden)

    Rini I Damayanti

    2005-10-01

    Full Text Available Infectious Bovine Rhinotracheitis is a disease of cattle characterised by clinical signs of the upper respiratory tract, reproductive tract and nervous system. A study to define the pathogenicity of four BHV-1 local isolates has been conducted. Fourteen Bali cattle that were free of BHV-1 has been selected and divided into four treatment groups. Each group of three was infected with virus isolate I, II, III and IV respectively with approximately a dose of 108TCID50 /10 ml and two cattle were used as control animals. Isolate I and III were originated from semen from IBR positive bulls number G 867 and G 148 respectively whereas isolate II was collected from vaginal mucosa and isolate IV was from nasal mucosa of IBR positive cattle treated with dexamethasone. Clinical response, gross-pathological and histopathological changes were observed. Immunohistochemical staining was applied to detect the antigen in tissue section. The results show that the BHV-1 local isolates could produce IBR syndrome namely fever and changes in the respiratory and reproductive tracts even though the clinical responses seemed to be disappeared by 21 days PI. Grossly there were hyperaemic nasal and vaginal mucosa and pneumonia whereas histologically there were non suppurative rhinitis, tracheitis, pneumonia and vulvovaginitis. Immunohistochemically the antigen was detected in the nasal concha and trachea. Dexamethasone treatment at 60-64 days PI could produce less severe clinical features and the second necroppsy at 69 days PI also results in less severe pathological responses. The findings also suggest that the pathogenicity of BHV-1 local isolates were as follows: isolates I, II, IV and III.

  8. A Novel Anti-Hepatitis C Virus and Antiproliferative Agent Alters Metabolic Networks in HepG2 and Hep3B Cells.

    Science.gov (United States)

    Keogh, Adrian; Şenkardeş, Sevil; Idle, Jeffrey R; Küçükgüzel, Ş Güniz; Beyoğlu, Diren

    2017-06-02

    A series of novel diflunisal hydrazide-hydrazones has been reported together with their anti-hepatitis C virus and antiproliferative activities in a number of human hepatoma cell lines. However, the mechanisms underlying the efficacy of these agents remain unclear. It was chosen to investigate the lead diflunisal hydrazide-hydrazone, 2',4'-difluoro-4-hydroxy-N'- [(pyridin-2-yl)methylidene]biphenyl-3-carbohydrazide (compound 3b), in two cultured human hepatoma cell lines-HepG2 and Hep3B-using a metabolomic protocol aimed at uncovering any effects of this agent on cellular metabolism. One sub-therapeutic concentration (2.5 μM) and one close to the IC50 for antimitotic effect (10 μM), after 72 h in cell culture, were chosen for both compound 3b and its inactive parent compound diflusinal as a control. A GCMS-based metabolomic investigation was performed on cell lysates after culture for 24 h. The intracellular levels of a total of 42 metabolites were found to be statistically significantly altered in either HepG2 or Hep3B cells, only eight of which were affected in both cell lines. It was concluded that compound 3b affected the following pathways-purine and pyrimidine catabolism, the glutathione cycle, and energy metabolism through glycolysis and the pentose phosphate pathway. Although the metabolomic findings occurred after 24 h in culture, significant cytotoxicity of compound 3b to both HepG2 and Hep3B cells at 10 μM were reported not to occur until 72 h in culture. These observations show that metabolomics can provide mechanistic insights into the efficacy of novel drug candidates prior to the appearance of their pharmacological effect.

  9. Data Preparation for West Nile Virus Agent-Based Modelling: Protocol for Processing Bird Population Estimates and Incorporating ArcMap in AnyLogic.

    Science.gov (United States)

    Nasrinpour, Hamid Reza; Reimer, Alexander A; Friesen, Marcia R; McLeod, Robert D

    2017-07-17

    West Nile Virus (WNV) was first isolated in 1937. Since the 1950s, many outbreaks have occurred in various countries. The first appearance of infected birds in Manitoba, Canada was in 2002. This paper describes the data preparation phase of setting up a geographic information system (GIS) simulation environment for WNV Agent-Based Modelling in Manitoba. The main technology used in this protocol is based on AnyLogic and ArcGIS software. A diverse variety of topics and techniques regarding the data collection phase are presented, as modelling WNV has many disparate attributes, including landscape and weather impacts on mosquito population dynamics and birds' roosting locations, population count, and movement patterns. Different maps were combined to create a grid land cover map of Manitoba, Canada in a shapefile format compatible with AnyLogic, in order to modulate mosquito parameters. A significant amount of data regarding 152 bird species, along with their population estimates and locations in Manitoba, were gathered and assembled. Municipality shapefile maps were converted to built-in AnyLogic GIS regions for better compatibility with census data and initial placement of human agents. Accessing shapefiles and their databases in AnyLogic are also discussed. AnyLogic simulation software in combination with Esri ArcGIS provides a powerful toolbox for developers and modellers to simulate almost any GIS-based environment or process. This research should be useful to others working on a variety of mosquito-borne diseases (eg, Zika, dengue, and chikungunya) by demonstrating the importance of data relating to Manitoba and/or introducing procedures to compile such data.

  10. Evaluación de vacunas peptídicas contra el virus de la fiebre aftosa en bovinos : Aislamiento y caracterización de mutantes de escape

    OpenAIRE

    Tami, María Cecilia

    1999-01-01

    EI virus de la fiebre aftosa (VFA) pertenece a la familia Picomaviridae y es el agente causal de la fiebre aftosa (FA). Esta enfermedad causa grandes pérdidas económicas en el mundo y se controla mediante vacunación regular con una vacuna a virus inactivado. Esta vacuna presenta desventajas relacionadas principalmente con la manipulación de grandes cantidades de virus vivo y la inactivación incompleta de las preparaciones virales. En este trabajo se evaluó el potencial de vacunas peptídicas r...

  11. Advances in Virus-Directed Therapeutics against Epstein-Barr Virus-Associated Malignancies

    Directory of Open Access Journals (Sweden)

    Sajal K. Ghosh

    2012-01-01

    Full Text Available Epstein-Barr virus (EBV is the causal agent in the etiology of Burkitt’s lymphoma and nasopharyngeal carcinoma and is also associated with multiple human malignancies, including Hodgkin’s and non-Hodgkin’s lymphoma, and posttransplantation lymphoproliferative disease, as well as sporadic cancers of other tissues. A causal relationship of EBV to these latter malignancies remains controversial, although the episomic EBV genome in most of these cancers is clonal, suggesting infection very early in the development of the tumor and a possible role for EBV in the genesis of these diseases. Furthermore, the prognosis of these tumors is invariably poor when EBV is present, compared to their EBV-negative counterparts. The physical presence of EBV in these tumors represents a potential “tumor-specific” target for therapeutic approaches. While treatment options for other types of herpesvirus infections have evolved and improved over the last two decades, however, therapies directed at EBV have lagged. A major constraint to pharmacological intervention is the shift from lytic infection to a latent pattern of gene expression, which persists in those tumors associated with the virus. In this paper we provide a brief account of new virus-targeted therapeutic approaches against EBV-associated malignancies.

  12. Characteristics of virus and virus-like rose degeneration and dieback diseases

    Directory of Open Access Journals (Sweden)

    Marek S. Szyndel

    2013-12-01

    Full Text Available Presented review of rose diseases, associated with the plant degeneration symptoms, includes rose streak, rose colour break, rose rosette or rose witches' broom, rose dieback, rose wilt, rose stunt, rose leaf curl, rose spring dwarf, rose little leaf, rose "frisure", rose bud proliferation and rose flower proliferation. Most of these disorders are characterized by stunting or dwarfing of plants accompanied by a partial wilt and dieback of shoots. Proliferation and epinasty often occurred. Apart from detected viruses (TSV. SLRSV parts of degeneration syndrome have been transmitted by grafting other have failed to achieve any transmission of the causal agent. It seems likely that rose degeneration disorders in spite of symptom similarities are due to a complex of interacting factors including probably viruses.

  13. Different Kinds of Causality in Event Cognition

    Science.gov (United States)

    Radvansky, Gabriel A.; Tamplin, Andrea K.; Armendarez, Joseph; Thompson, Alexis N.

    2014-01-01

    Narrative memory is better for information that is more causally connected and occurs at event boundaries, such as a causal break. However, it is unclear whether there are common or distinct influences of causality. For the event boundaries that arise as a result of causal breaks, the events that follow may subsequently become more causally…

  14. Hierarchical organisation of causal graphs

    Energy Technology Data Exchange (ETDEWEB)

    Dziopa, P. [CEA Centre d`Etudes de la Vallee du Rhone, 30 - Marcoule (France). Dept. des Procedes de Retraitement; Gentil, S. [ENSIEG, 38 - Saint-Martin d`Heres (France)

    1993-12-31

    This paper deals with the design of a supervision system using a hierarchy of models formed by graphs, in which the variables are the nodes and the causal relations between the variables of the arcs. To obtain a representation of the variables evolutions which contains only the relevant features of their real evolutions, the causal relations are completed with qualitative transfer functions (QTFs) which produce roughly the behaviour of the classical transfer functions. Major improvements have been made in the building of the hierarchical organization. First, the basic variables of the uppermost level and the causal relations between them are chosen. The next graph is built by adding intermediary variables to the upper graph. When the undermost graph has been built, the transfer functions parameters corresponding to its causal relations are identified. The second task consists in the upwelling of the information from the undermost graph to the uppermost one. A fusion procedure of the causal relations has been designed to compute the QFTs relevant for each level. This procedure aims to reduce the number of parameters needed to represent an evolution at a high level of abstraction. These techniques have been applied to the hierarchical modelling of nuclear process. (authors). 8 refs., 12 figs.

  15. Causal reasoning with mental models

    Directory of Open Access Journals (Sweden)

    Sangeet eKhemlani

    2014-10-01

    Full Text Available This paper outlines the model-based theory of causal reasoning. It postulates that the core meanings of causal assertions are deterministic and refer to temporally-ordered sets of possibilities: A causes B to occur means that given A, B occurs, whereas A enables B to occur means that given A, it is possible for B to occur. The paper shows how mental models represent such assertions, and how these models underlie deductive, inductive, and abductive reasoning yielding explanations. It reviews evidence both to corroborate the theory and to account for phenomena sometimes taken to be incompatible with it. Finally, it reviews neuroscience evidence indicating that mental models for causal inference are implemented within lateral prefrontal cortex.

  16. Reasoning about causal relationships: Inferences on causal networks.

    Science.gov (United States)

    Rottman, Benjamin Margolin; Hastie, Reid

    2014-01-01

    Over the last decade, a normative framework for making causal inferences, Bayesian Probabilistic Causal Networks, has come to dominate psychological studies of inference based on causal relationships. The following causal networks-[X→Y→Z, X←Y→Z, X→Y←Z]-supply answers for questions like, "Suppose both X and Y occur, what is the probability Z occurs?" or "Suppose you intervene and make Y occur, what is the probability Z occurs?" In this review, we provide a tutorial for how normatively to calculate these inferences. Then, we systematically detail the results of behavioral studies comparing human qualitative and quantitative judgments to the normative calculations for many network structures and for several types of inferences on those networks. Overall, when the normative calculations imply that an inference should increase, judgments usually go up; when calculations imply a decrease, judgments usually go down. However, 2 systematic deviations appear. First, people's inferences violate the Markov assumption. For example, when inferring Z from the structure X→Y→Z, people think that X is relevant even when Y completely mediates the relationship between X and Z. Second, even when people's inferences are directionally consistent with the normative calculations, they are often not as sensitive to the parameters and the structure of the network as they should be. We conclude with a discussion of productive directions for future research. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

  17. [Causal analysis approaches in epidemiology].

    Science.gov (United States)

    Dumas, O; Siroux, V; Le Moual, N; Varraso, R

    2014-02-01

    Epidemiological research is mostly based on observational studies. Whether such studies can provide evidence of causation remains discussed. Several causal analysis methods have been developed in epidemiology. This paper aims at presenting an overview of these methods: graphical models, path analysis and its extensions, and models based on the counterfactual approach, with a special emphasis on marginal structural models. Graphical approaches have been developed to allow synthetic representations of supposed causal relationships in a given problem. They serve as qualitative support in the study of causal relationships. The sufficient-component cause model has been developed to deal with the issue of multicausality raised by the emergence of chronic multifactorial diseases. Directed acyclic graphs are mostly used as a visual tool to identify possible confounding sources in a study. Structural equations models, the main extension of path analysis, combine a system of equations and a path diagram, representing a set of possible causal relationships. They allow quantifying direct and indirect effects in a general model in which several relationships can be tested simultaneously. Dynamic path analysis further takes into account the role of time. The counterfactual approach defines causality by comparing the observed event and the counterfactual event (the event that would have been observed if, contrary to the fact, the subject had received a different exposure than the one he actually received). This theoretical approach has shown limits of traditional methods to address some causality questions. In particular, in longitudinal studies, when there is time-varying confounding, classical methods (regressions) may be biased. Marginal structural models have been developed to address this issue. In conclusion, "causal models", though they were developed partly independently, are based on equivalent logical foundations. A crucial step in the application of these models is the

  18. Quantum theory and local causality

    CERN Document Server

    Hofer-Szabó, Gábor

    2018-01-01

    This book summarizes the results of research the authors have pursued in the past years on the problem of implementing Bell's notion of local causality in local physical theories and relating it to other important concepts and principles in the foundations of physics such as the Common Cause Principle, Bell's inequalities, the EPR (Einstein-Podolsky-Rosen) scenario, and various other locality and causality concepts. The book is intended for philosophers of science with an interest in the formal background of sciences, philosophers of physics and physicists working in foundation of physics.

  19. Viruses Infecting Reptiles

    Science.gov (United States)

    Marschang, Rachel E.

    2011-01-01

    A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions. PMID:22163336

  20. Viruses Infecting Reptiles

    Directory of Open Access Journals (Sweden)

    Rachel E. Marschang

    2011-11-01

    Full Text Available A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.

  1. Viruses infecting reptiles.

    Science.gov (United States)

    Marschang, Rachel E

    2011-11-01

    A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch's postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.

  2. Causal feedbacks in climate change

    NARCIS (Netherlands)

    Nes, van E.H.; Scheffer, M.; Brovkin, V.; Lenton, T.M.; Ye, H.; Deyle, E.; Sugihara, G.

    2015-01-01

    The statistical association between temperature and greenhouse gases over glacial cycles is well documented1, but causality behind this correlation remains difficult to extract directly from the data. A time lag of CO2 behind Antarctic temperature—originally thought to hint at a driving role for

  3. Granger Causality and Unit Roots

    DEFF Research Database (Denmark)

    Rodríguez-Caballero, Carlos Vladimir; Ventosa-Santaulària, Daniel

    2014-01-01

    The asymptotic behavior of the Granger-causality test under stochastic nonstationarity is studied. Our results confirm that the inference drawn from the test is not reliable when the series are integrated to the first order. In the presence of deterministic components, the test statistic diverges...

  4. Entanglement, holography and causal diamonds

    NARCIS (Netherlands)

    de Boer, J.; Haehl, F.M.; Heller, M.P.; Myers, R.C.

    We argue that the degrees of freedom in a d-dimensional CFT can be reorganized in an insightful way by studying observables on the moduli space of causal diamonds (or equivalently, the space of pairs of timelike separated points). This 2d-dimensional space naturally captures some of the fundamental

  5. In vitro inhibition of pathogenic Verticillium dahliae, causal agent of ...

    African Journals Online (AJOL)

    SAM

    2014-08-13

    Aug 13, 2014 ... Trichoderma isolates under a dual culture condition on potato dextrose agar plate. The 33 ... in many countries, like USA, New Zealand, the Pacific .... levels of pathogenicity in potato. Trichoderma isolates were tested in vitro for their highest antagonistic ability over V. dahliae colony in dual culture.

  6. Diplodia natalensis , Pole Evans: a causal agent of citrus gummosis ...

    African Journals Online (AJOL)

    Isolations were made from the barks of gummosis-infected citrus trees from orchards of the University of Ghana Agricultural Research Station at Kade. The isolation media used were 1.5% water agar, 1.5% water agar + nystatin and 1.5% water agar + benomyl. Four isolates including Diplodia natalensis Pole Evans, ...

  7. Diplodia natalensis Pole Evans, the causal agent of citrus gummosis ...

    African Journals Online (AJOL)

    Four isolates including Diplodia natalensis Pole Evans, Fusarium solani Appel + Wr., and two other identified fungi were obtained. The two fungi were unidentified on Potato Dextrose Agar (PDA). When the isolates were tested for pathogenicity, only D. natalensis induced the disease symptoms in the inoculated ...

  8. Attributing causal agents to nationwide maps of forest disturbance

    Science.gov (United States)

    Gretchen G. Moisen; Todd A. Schroeder; Karen Schleeweis; Chris Toney; Warren B. Cohen; Samuel N. Goward

    2012-01-01

    Currently in its third phase, the North American Forest Dynamics (NAFD) project has launched nationwide processing of historic Landsat data to provide a comprehensive annual, wall-to-wall analysis of U.S. disturbance history over the last 30+ years. Because understanding the cause of disturbance is important to quantifying carbon dynamics, work is underway to attribute...

  9. Entanglement, holography and causal diamonds

    Energy Technology Data Exchange (ETDEWEB)

    Boer, Jan de [Institute of Physics, Universiteit van Amsterdam,Science Park 904, 1090 GL Amsterdam (Netherlands); Haehl, Felix M. [Centre for Particle Theory & Department of Mathematical Sciences, Durham University,South Road, Durham DH1 3LE (United Kingdom); Heller, Michal P.; Myers, Robert C. [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada)

    2016-08-29

    We argue that the degrees of freedom in a d-dimensional CFT can be re-organized in an insightful way by studying observables on the moduli space of causal diamonds (or equivalently, the space of pairs of timelike separated points). This 2d-dimensional space naturally captures some of the fundamental nonlocality and causal structure inherent in the entanglement of CFT states. For any primary CFT operator, we construct an observable on this space, which is defined by smearing the associated one-point function over causal diamonds. Known examples of such quantities are the entanglement entropy of vacuum excitations and its higher spin generalizations. We show that in holographic CFTs, these observables are given by suitably defined integrals of dual bulk fields over the corresponding Ryu-Takayanagi minimal surfaces. Furthermore, we explain connections to the operator product expansion and the first law of entanglement entropy from this unifying point of view. We demonstrate that for small perturbations of the vacuum, our observables obey linear two-derivative equations of motion on the space of causal diamonds. In two dimensions, the latter is given by a product of two copies of a two-dimensional de Sitter space. For a class of universal states, we show that the entanglement entropy and its spin-three generalization obey nonlinear equations of motion with local interactions on this moduli space, which can be identified with Liouville and Toda equations, respectively. This suggests the possibility of extending the definition of our new observables beyond the linear level more generally and in such a way that they give rise to new dynamically interacting theories on the moduli space of causal diamonds. Various challenges one has to face in order to implement this idea are discussed.

  10. Direct-acting antiviral agents in the therapy of hepatitis C virus-related mixed cryoglobulinaemia: a single-centre experience.

    Science.gov (United States)

    Lauletta, Gianfranco; Russi, Sabino; Pavone, Fabio; Vacca, Angelo; Dammacco, Franco

    2017-04-08

    The efficacy and safety of direct-acting antiviral agents (DAAs) were evaluated in a cohort of prospectively enrolled patients with hepatitis C virus (HCV)-related mixed cryoglobulinaemia (MC), an immune complex-mediated vasculitis of small and medium vessels in which the pathogenetic role of HCV has been clearly established. Twenty-two patients received DAAs. Clinical and laboratory features were recorded at baseline, every 4 weeks until the end of treatment (EoT), and 12 weeks afterwards. Primary efficacy endpoints were (a) sustained virological response 12 weeks after therapy completion (SVR12), (b) regression of symptomatology (clinical response) and (c) cryoglobulin disappearance or cryocrit reduction ≥50% (immunological response). Complete response (CR) was defined as the occurrence of all three primary endpoints; partial response (PR) was defined as the occurrence of SVR12, with or without either immunological or clinical response; and no response was defined as missing the achievement of all three endpoints. All patients reached SVR12. Compared with basal values, mean cryocrit values were significantly decreased at EoT and SVR12. A significant reduction of alanine transaminase and a parallel increase of complement component C4 levels were also detected. Rheumatoid factor activity was significantly reduced at EoT but not at SVR12. At SVR12, a CR was established in 14 patients (63.7%) and a PR in 8 patients (36.3%). In one patient with small lymphocytic lymphoma, the tumour progressed despite viral clearance. Mild adverse events were recorded in nine patients (40.9%). The response rates induced by the use of DAAs in patients with MC were remarkably higher than those previously achieved with pegylated interferon-α/ribavirin, with or without rituximab. A much longer follow-up is desirable to achieve useful information in terms of persistent viral clearance and clinical response.

  11. Naturally Occurring Resistance-Associated Variants to Hepatitis C Virus Direct-Acting Antiviral Agents in Treatment-Naive HCV Genotype 6a-Infected Patients

    Directory of Open Access Journals (Sweden)

    Zhanyi Li

    2017-01-01

    Full Text Available Background and Objective. The direct-acting antiviral agents (DAAs antiviral therapy has drastically improved the prognosis of hepatitis C virus (HCV patients. However, the viral drug resistance-associated variants (RAVs can limit the efficacy of DAAs. For the HCV-6a is not the predominant prevalent genotype; the data on the prevalence of naturally occurring RAVs in it is scarce. Our study aims to assess the prevalence of RAVs in treatment-naive HCV-6a patients. Methods. Nested PCR assays were performed on 95 HCV-6a patients to amplify HCV viral regions of NS3, NS5A, and NS5B. Results. In NS3/4A region, we detected Q80K in 95.5% isolates (84/88 and D168E in 2.3% isolates (2/88. In NS5A region, we detected Q30R in 93.2% isolates (82/88, L31M in 4.6% isolates (4/88, and H58P in 6.8% isolates (6/88. In NS5B region, we detected A15G in 2.3% isolates (2/88, S96T in 1.1% isolates (1/88, and S282T in 20.7% isolates (17/88 and we detected I482L in 100% isolates (4/4, V494A in 50% isolates (2/4, and V499A in 100% isolates (4/4. Conclusions. RAVs to DAAs preexist in treatment-naive HCV-6a patients. Further studies should address the issue of the impact of RAVs in response to DAA therapies for HCV-6a patients.

  12. An outbreak of post-vaccinal rabies (rage de laboratoire) in Fortaleza, Brazil, in 1960. Residual fixed virus as the etiological agent.

    Science.gov (United States)

    Pará, M

    1965-01-01

    The repeated isolation of fixed rabies virus from the CNS tissues of victims of an acute and lethal outbreak of encephalomyelitis in Fortaleza, Brazil, in November 1960, following vaccination with a locally produced killed-virus anti-rabies vaccine of the Fermi type is considered as definitive evidence of the rabic etiology (vaccinal fixed-virus rabies, rage de laboratoire) of this outbreak. Eighteen persons were affected, all of whom died.The clinical picture of paralytic rabies was recognizable in all of these 18 patients. The well-marked characteristics of an acute infection permit the easy differentiation of the paralysis caused by fixed rabies virus from post-vaccinal accidents that occur as allergic reactions.The incriminated anti-rabies vaccine was found to contain fixed live rabies virus at a titre of 10(-3.0). After one year of storage under refrigeration, the vaccine still contained fixed rabies virus, at a titre of 0,2x10(-1.0).Subsequent laboratory studies tend to indicate that the curve of inactivation of fixed virus by phenol does not follow a linear function but rather resembles the curve of inactivation of poliomyelitis virus by heat and formol according to the Salk technique. It is suggested that the antigenicity of the so-called "killed-virus" anti-rabies vaccines is actually due to the presence in them of residual amounts of live virus.

  13. On the Causality and K-Causality between Measures

    Directory of Open Access Journals (Sweden)

    Tomasz Miller

    2017-03-01

    Full Text Available Drawing from the optimal transport theory adapted to the Lorentzian setting, we propose and study the extension of the Sorkin–Woolgar causal relation K + onto the space of Borel probability measures on a given spacetime. We show that it retains its fundamental properties of transitivity and closedness. Furthermore, we list and prove several characterizations of this relation, including the “measure-theoretic” analogue of the characterization of K + in terms of time functions.

  14. Isolation and characterization of virus of highly pathogenic avian influenza H5 subtype of chicken from outbreaks in Indonesia

    Directory of Open Access Journals (Sweden)

    Agus Wiyono

    2004-03-01

    Full Text Available A study on the isolation and characterization of Highly Pathogenic Avian Influenza of chicken from outbreaks in Indonesia was conducted at Indonesian Research Institute for Veterinary Science. Outbreaks of avian disease had been reported in Indonesia since August 2003 affecting commercial layer, broiler, quail, and ostrich and also native chicken with showing clinical signs such as cyanosis of wattle and comb, nasal discharges and hypersalivation, subcutaneous ptechiae on foot and leg, diarre and sudden high mortality. The aim of this study is to isolate and characterize the causal agent of the disease. Samples of serum, feather follicle, tracheal swab, as well as organs of proventriculus, intestine, caecal tonsil, trachea and lungs were collected from infected animals. Serum samples were tested haemaglutination/haemaglutination inhibition to Newcastle Disease and Egg Drop Syndrome viruses. Isolation of virus of the causal agent of the outbreak was conducted from samples of feather follicle, tracheal swab, and organs using 11 days old specific pathogen free (SPF embryonated eggs. The isolated viruses were then characterised by agar gel precipitation test using swine influenza reference antisera, by haemaglutination inhibition using H1 to H15 reference antisera, and by electron microscope examination. The pathogenicity of the viruses was confirmed by intravenous pathogenicity index test and its culture in Chicken Embryo Fibroblast primary cell culture without addition of trypsin. The study revealed that the causative agent of the outbreaks of avian disease in Indonesia was avian influenza H5 subtype virus based upon serological tests, virus isolation and characterization using swine influenza reference antisera, and electron microscope examination. While subtyping of the viruses using H1 to H15 reference antisera suggested that the virus is very likely to be an avian influenza H5N1 subtype virus. The pathogenicity test confirmed that the viruses

  15. Viruses and Human Cancers: a Long Road of Discovery of Molecular Paradigms

    Science.gov (United States)

    White, Martyn K.; Pagano, Joseph S.

    2014-01-01

    SUMMARY About a fifth of all human cancers worldwide are caused by infectious agents. In 12% of cancers, seven different viruses have been causally linked to human oncogenesis: Epstein-Barr virus, hepatitis B virus, human papillomavirus, human T-cell lymphotropic virus, hepatitis C virus, Kaposi's sarcoma herpesvirus, and Merkel cell polyomavirus. Here, we review the many molecular mechanisms of oncogenesis that have been discovered over the decades of study of these viruses. We discuss how viruses can act at different stages in the complex multistep process of carcinogenesis. Early events include their involvement in mutagenic events associated with tumor initiation such as viral integration and insertional mutagenesis as well as viral promotion of DNA damage. Also involved in tumor progression is the dysregulation of cellular processes by viral proteins, and we describe how this has been investigated by studies in cell culture and in experimental animals and by molecular cellular approaches. Also important are the molecular mechanisms whereby viruses interact with the immune system and the immune evasion strategies that have evolved. PMID:24982317

  16. Causal Pixel Purity Index (PPI)

    Science.gov (United States)

    Wu, Chao-Cheng; Chang, Chein-I.

    2009-05-01

    Pixel Purity Index (PPI) has been widely used in endmember extraction. While it is available in ENVI software there are several interesting issues arising in its implementation. This paper re-invents the wheel by re-visiting the design rationale of the PPI and re-designing algorithms to implement PPI. More specifically, it develops the so-called Causal PPI (CPPI) which implements the PPI in a causal manner in the sense that the information used for data processing is only up to the data sample currently being visited. If the time required for computer processing is negligible, the CPPI actually becomes a real time PPI. The proposed CPPI can be implemented automatically and resolves the main issue of requiring human intervention to determine parameters.

  17. Identifying Causality from Alarm Observations

    DEFF Research Database (Denmark)

    Kirchhübel, Denis; Zhang, Xinxin; Lind, Morten

    on an abstracted model of the mass and energy flows in the system. The application of MFM for root cause analysis based alarm grouping has been demonstrated and can be extended to reason about the direction of causality considering the entirety of the alarms present in the system for more comprehensive decision...... and consequences. This extended analysis results in causal paths from likely root causes to tentative consequences, providing the operator with a comprehensive tool to not only identify but also rank the criticality of a large number of concurrent alarms in the system....... support. This contribution presents the foundation for combining the cause and consequence propagation of multiple observations from the system based on an MFM model. The proposed logical reasoning matches actually observed alarms to the propagation analysis in MFM to distinguish plausible causes...

  18. Viruses in cancer treatment.

    Science.gov (United States)

    Alemany, R

    2013-03-01

    Soon after the discovery that viruses cause human disease, started the idea of using viruses to treat cancer. After the initial indiscriminate use, crude preparations of each novel virus in the early twentieth century, a second wave of virotherapy blossomed in the 60s with purified and selected viruses. Responses were rare and short-lived. Immune rejection of the oncolytic viruses was identified as the major problem and virotherapy was abandoned. During the past two decades virotherapy has re-emerged with engineered viruses, with a trend towards using them as tumor-debulking immunostimulatory agents combined with radio or chemotherapy. Currently, oncolytic Reovirus, Herpes, and Vaccinia virus are in late phase clinical trials. Despite the renewed hope, efficacy will require improving systemic tumor targeting, overcoming stroma barriers for virus spread, and selectively stimulating immune responses against tumor antigens but not against the virus. Virotherapy history, viruses, considerations for clinical trials, and hurdles are briefly overviewed.

  19. THE CAUSAL ANALYSIS / DIAGNOSIS DECISION ...

    Science.gov (United States)

    CADDIS is an on-line decision support system that helps investigators in the regions, states and tribes find, access, organize, use and share information to produce causal evaluations in aquatic systems. It is based on the US EPA's Stressor Identification process which is a formal method for identifying causes of impairments in aquatic systems. CADDIS 2007 increases access to relevant information useful for causal analysis and provides methods and tools that practitioners can use to analyze their own data. The new Candidate Cause section provides overviews of commonly encountered causes of impairments to aquatic systems: metals, sediments, nutrients, flow alteration, temperature, ionic strength, and low dissolved oxygen. CADDIS includes new Conceptual Models that illustrate the relationships from sources to stressors to biological effects. An Interactive Conceptual Model for phosphorus links the diagram with supporting literature citations. The new Analyzing Data section helps practitioners analyze their data sets and interpret and use those results as evidence within the USEPA causal assessment process. Downloadable tools include a graphical user interface statistical package (CADStat), and programs for use with the freeware R statistical package, and a Microsoft Excel template. These tools can be used to quantify associations between causes and biological impairments using innovative methods such as species-sensitivity distributions, biological inferenc

  20. Identification and characterization of citrus yellow vein clearing virus, a putative new member of the genus Mandarivirus.

    Science.gov (United States)

    Loconsole, G; Onelge, N; Potere, O; Giampetruzzi, A; Bozan, O; Satar, S; De Stradis, A; Savino, V; Yokomi, R K; Saponari, M

    2012-12-01

    Molecular features and genomic organization were determined for Citrus yellow vein clearing virus (CYVCV), the putative viral causal agent of yellow vein clearing disease of lemon trees, reported in Pakistan, India, and more recently in Turkey and China. CYVCV isolate Y1 from Adana, Turkey, was used for deep sequencing analysis of the virus-induced small RNA fractions and for mechanical and graft inoculation of herbaceous and citrus indicator plants. A polyclonal antiserum was developed from CYVCV-Y1 purified from Phaseolus vulgaris and used in western blot assays to characterize the coat protein of CYVCV-Y1 and determine its serological relationship with related viruses. Contigs assembled from the Illumina sequenced short reads were used to construct the whole genome of Citrus yellow vein clearing virus (CYVCV), consisting in a positive-sense RNA of 7,529 nucleotides and containing six predicted open reading frames. The CYVCV genome organization and size resembled that of flexiviruses, and search for sequence homologies revealed that Indian citrus ringspot virus (ICRSV) (Mandarivirus, Alphaflexiviridae) is the most closely related virus. However, CYVCV had an overall nucleotide sequence identity of ≈74% with ICRSV. Although the two viruses were similar with regard to genome organization, viral particles, and herbaceous host range, CYVCV caused different symptoms in citrus and was serologically distinct from ICRSV. Primer pairs were designed and used to detect the virus by conventional and quantitative reverse transcription-polymerase chain reaction on yellow vein clearing symptomatic field trees as well as graft- and mechanically inoculated host plants. Collectively, these data suggest that CYVCV is the causal agent of yellow vein clearing disease and represents a new species in the genus Mandarivirus.

  1. The argumentative impact of causal relations

    DEFF Research Database (Denmark)

    Nielsen, Anne Ellerup

    1996-01-01

    such as causality, explanation and justification. In certain types of discourse, causal relations also imply an intentional element. This paper describes the way in which the semantic and pragmatic functions of causal markers can be accounted for in terms of linguistic and rhetorical theories of argumentation....

  2. On Fixed Points of Strictly Causal Functions

    Science.gov (United States)

    2013-04-08

    of the input. This is probably a folklore definition, but one that is universally accepted. After a careful, precise formalization of it, we show the...causal functions In this section, we formalize the folklore , but well established, notions of causality and strict causality, and through a series of

  3. Representing Personal Determinants in Causal Structures.

    Science.gov (United States)

    Bandura, Albert

    1984-01-01

    Responds to Staddon's critique of the author's earlier article and addresses issues raised by Staddon's (1984) alternative models of causality. The author argues that it is not the formalizability of causal processes that is the issue but whether cognitive determinants of behavior are reducible to past stimulus inputs in causal structures.…

  4. Exploring Individual Differences in Preschoolers' Causal Stance

    Science.gov (United States)

    Alvarez, Aubry; Booth, Amy E.

    2016-01-01

    Preschoolers, as a group, are highly attuned to causality, and this attunement is known to facilitate memory, learning, and problem solving. However, recent work reveals substantial individual variability in the strength of children's "causal stance," as demonstrated by their curiosity about and preference for new causal information. In…

  5. Causal knowledge and reasoning in decision making

    NARCIS (Netherlands)

    Hagmayer, Y.; Witteman, C.L.M.

    2017-01-01

    Normative causal decision theories argue that people should use their causal knowledge in decision making. Based on these ideas, we argue that causal knowledge and reasoning may support and thereby potentially improve decision making based on expected outcomes, narratives, and even cues. We will

  6. Viruses are frequently present as the infecting agent in acute exacerbations of chronic obstructive pulmonary disease in patients presenting to hospital.

    Science.gov (United States)

    Biancardi, E; Fennell, M; Rawlinson, W; Thomas, P S

    2016-10-01

    Viral causes of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are well recognised but only recently have rapid tests become available. To identify respiratory viruses in the general population and those associated with hospitalisation in AECOPD using polymerase chain reaction (PCR) on nasopharyngeal aspirate (NPA), and the relationship between symptoms, viral detection and inflammatory markers. A review of viruses detected in the general population in a health district between August 2014 and July 2015, using multiplex PCR for viruses from NPA samples. In addition, a single hospital, retrospective audit of patients admitted with suspected AECOPD was conducted. Of the 8811 NPA tested, 5599 (64%) were positive for at least one virus and 2069 of these were obtained from adults. In adults, the most common viruses identified were Influenza A (31%), Rhinovirus (27%) and respiratory syncytial virus A/B (10%). Most patients with AECOPD (102 of 153) had NPA sent for viral PCR testing and 59 (58%) were positive. The most common viruses identified were Influenza A (31%), Rhinovirus (24%) and respiratory syncytial virus A/B (17%) with co-infecting bacteria cultured in 22 sputum samples. Patients with influenza-like symptoms were more likely to have a positive viral PCR than those without symptoms (P < 0.004). The median C-reactive protein on admission was lower in the virus-infected than uninfected AECOPD (28 vs 60 mg/L, P < 0.026). The spectrum of viruses detected in patients with AECOPD is similar to that of the general population. Viruses are more likely to be identified in patients with AECOPD who present with influenza-like symptoms and a low C-reactive protein. © 2016 Royal Australasian College of Physicians.

  7. Does Causal Action Facilitate Causal Perception in Infants Younger than 6 Months of Age?

    Science.gov (United States)

    Rakison, David H.; Krogh, Lauren

    2012-01-01

    Previous research has established that infants are unable to perceive causality until 6 1/4 months of age. The current experiments examined whether infants' ability to engage in causal action could facilitate causal perception prior to this age. In Experiment 1, 4 1/2-month-olds were randomly assigned to engage in causal action experience via…

  8. Norms and customs: causally important or causally impotent?

    Science.gov (United States)

    Jones, Todd

    2010-01-01

    In this article, I argue that norms and customs, despite frequently being described as being causes of behavior in the social sciences and ordinary conversation, cannot really cause behavior. Terms like "norms" and the like seem to refer to philosophically disreputable disjunctive properties. More problematically, even if they do not, or even if there can be disjunctive properties after all, I argue that norms and customs still cannot cause behavior. The social sciences would be better off without referring to properties like norms and customs as if they could be causal.

  9. A Current Overview of the Papaya meleira virus, an Unusual Plant Virus

    Science.gov (United States)

    Abreu, Paolla M. V.; Antunes, Tathiana F. S.; Magaña-Álvarez, Anuar; Pérez-Brito, Daisy; Tapia-Tussell, Raúl; Ventura, José A.; Fernandes, Antonio A. R.; Fernandes, Patricia M. B.

    2015-01-01

    Papaya meleira virus (PMeV) is the causal agent of papaya sticky disease, which is characterized by a spontaneous exudation of fluid and aqueous latex from the papaya fruit and leaves. The latex oxidizes after atmospheric exposure, resulting in a sticky feature on the fruit from which the name of the disease originates. PMeV is an isometric virus particle with a double-stranded RNA (dsRNA) genome of approximately 12 Kb. Unusual for a plant virus, PMeV particles are localized on and linked to the polymers present in the latex. The ability of the PMeV to inhabit such a hostile environment demonstrates an intriguing interaction of the virus with the papaya. A hypersensitivity response is triggered against PMeV infection, and there is a reduction in the proteolytic activity of papaya latex during sticky disease. In papaya leaf tissues, stress responsive proteins, mostly calreticulin and proteasome-related proteins, are up regulated and proteins related to metabolism are down-regulated. Additionally, PMeV modifies the transcription of several miRNAs involved in the modulation of genes related to the ubiquitin-proteasome system. Until now, no PMeV resistant papaya genotype has been identified and roguing is the only viral control strategy available. However, a single inoculation of papaya plants with PMeV dsRNA delayed the progress of viral infection. PMID:25856636

  10. A Current Overview of the Papaya meleira virus, an Unusual Plant Virus

    Directory of Open Access Journals (Sweden)

    Paolla M. V. Abreu

    2015-04-01

    Full Text Available Papaya meleira virus (PMeV is the causal agent of papaya sticky disease, which is characterized by a spontaneous exudation of fluid and aqueous latex from the papaya fruit and leaves. The latex oxidizes after atmospheric exposure, resulting in a sticky feature on the fruit from which the name of the disease originates. PMeV is an isometric virus particle with a double-stranded RNA (dsRNA genome of approximately 12 Kb. Unusual for a plant virus, PMeV particles are localized on and linked to the polymers present in the latex. The ability of the PMeV to inhabit such a hostile environment demonstrates an intriguing interaction of the virus with the papaya. A hypersensitivity response is triggered against PMeV infection, and there is a reduction in the proteolytic activity of papaya latex during sticky disease. In papaya leaf tissues, stress responsive proteins, mostly calreticulin and proteasome-related proteins, are up regulated and proteins related to metabolism are down-regulated. Additionally, PMeV modifies the transcription of several miRNAs involved in the modulation of genes related to the ubiquitin-proteasome system. Until now, no PMeV resistant papaya genotype has been identified and roguing is the only viral control strategy available. However, a single inoculation of papaya plants with PMeV dsRNA delayed the progress of viral infection.

  11. The key role of causal explanation in the climate change issue

    Directory of Open Access Journals (Sweden)

    Francesca Pongiglione

    2012-06-01

    Full Text Available The basis for adoption of pro-environment behaviour is the understanding of causal passages within climate dynamics. The understanding of the causes of climate change is necessary in order to be able to take mitigation actions  (the subject needs to be aware of his role as a causal agent. Conversely, the understanding of the consequences of climate change is essential in motivating action (the subject must be aware of the risks caused by it in order to prevent them. The case of ozone depletion confirms this view: the understanding of its causal dynamics played a determining role in people’s behavioural response.

  12. Experimental verification of an indefinite causal order.

    Science.gov (United States)

    Rubino, Giulia; Rozema, Lee A; Feix, Adrien; Araújo, Mateus; Zeuner, Jonas M; Procopio, Lorenzo M; Brukner, Časlav; Walther, Philip

    2017-03-01

    Investigating the role of causal order in quantum mechanics has recently revealed that the causal relations of events may not be a priori well defined in quantum theory. Although this has triggered a growing interest on the theoretical side, creating processes without a causal order is an experimental task. We report the first decisive demonstration of a process with an indefinite causal order. To do this, we quantify how incompatible our setup is with a definite causal order by measuring a "causal witness." This mathematical object incorporates a series of measurements that are designed to yield a certain outcome only if the process under examination is not consistent with any well-defined causal order. In our experiment, we perform a measurement in a superposition of causal orders-without destroying the coherence-to acquire information both inside and outside of a "causally nonordered process." Using this information, we experimentally determine a causal witness, demonstrating by almost 7 SDs that the experimentally implemented process does not have a definite causal order.

  13. Causal capture effects in chimpanzees (Pan troglodytes).

    Science.gov (United States)

    Matsuno, Toyomi; Tomonaga, Masaki

    2017-01-01

    Extracting a cause-and-effect structure from the physical world is an important demand for animals living in dynamically changing environments. Human perceptual and cognitive mechanisms are known to be sensitive and tuned to detect and interpret such causal structures. In contrast to rigorous investigations of human causal perception, the phylogenetic roots of this perception are not well understood. In the present study, we aimed to investigate the susceptibility of nonhuman animals to mechanical causality by testing whether chimpanzees perceived an illusion called causal capture (Scholl & Nakayama, 2002). Causal capture is a phenomenon in which a type of bistable visual motion of objects is perceived as causal collision due to a bias from a co-occurring causal event. In our experiments, we assessed the susceptibility of perception of a bistable stream/bounce motion event to a co-occurring causal event in chimpanzees. The results show that, similar to in humans, causal "bounce" percepts were significantly increased in chimpanzees with the addition of a task-irrelevant causal bounce event that was synchronously presented. These outcomes suggest that the perceptual mechanisms behind the visual interpretation of causal structures in the environment are evolutionarily shared between human and nonhuman animals. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. CADDIS Volume 1. Stressor Identification: About Causal Assessment

    Science.gov (United States)

    An introduction to the history of our approach to causal assessment, A chronology of causal history and philosophy, An introduction to causal history and philosophy, References for the Causal Assessment Background section of Stressor Identification

  15. THE PORIFERASTA COMPOUND-5,22E,25-TRIEN-3-Oβ FROM Clerodendrum paniculatum LEAF AS INDUCER AGENT OF SYSTEMIC RESISTANCE ON RED CHILLI PLANT Capsicum annuum L FROM CUCUMBER MOSAIC VIRUS (CMV

    Directory of Open Access Journals (Sweden)

    Weny Musa

    2010-06-01

    Full Text Available The poriferasta-5.22E.25-trien-3β-ol compound of leaves of this plant Clerodendrum paniculatum has activity as an inducer agent of plant systemic resistance of red plant toward Cucumber Mosaic Viruses (CMV, the inhibition activity compound shows 82% inhibition activity at 300 ppm. The structure of these compound were determined on the basis of spectroscopic data including UV, IR, 1H-NMR, 13C-NMR and 2D-NMR   Keywords: Poriferasta-5.22E.25-trien-3β-ol, Clerodendrum paniculatum, induction of systemic resistance, CMV

  16. Causal viscous cosmology without singularities

    CERN Document Server

    Laciana, Carlos E

    2016-01-01

    An isotropic and homogeneous cosmological model with a source of dark energy is studied. That source is simulated with a viscous relativistic fluid with minimal causal correction. In this model the restrictions on the parameters coming from the following conditions are analized: a) energy density without singularities along time, b) scale factor increasing with time, c) universe accelerated at present time, d) state equation for dark energy with "w" bounded and close to -1. It is found that those conditions are satified for the following two cases. i) When the transport coefficient ({\\tau}_{{\\Pi}}), associated to the causal correction, is negative, with the aditional restriction {\\zeta}|{\\tau}_{{\\Pi}}|>2/3, where {\\zeta} is the relativistic bulk viscosity coefficient. The state equation is in the "phantom" energy sector. ii) For {\\tau}_{{\\Pi}} positive, in the "k-essence" sector. It is performed an exact calculation for the case where the equation of state is constant, finding that option (ii) is favored in r...

  17. Laem-Singh Virus: A Probable Etiological Agent Associated with Monodon Slow Growth Syndrome in Farmed Black Tiger Shrimp (Penaeus monodon)

    OpenAIRE

    Poornima, M.; Seetang-Nun, Y.; Alavandi, S. V.; Dayal, J. Syama

    2012-01-01

    Among the emerging diseases in shrimp aquaculture, monodon slow growth syndrome (MSGS) is a major concern in South and Southeast Asia. Shrimp farming in Thailand was severely affected during 2000–2002 due to MSGS, which caused an economic loss, of about US$ 300 million. MSGS is characterized by abnormally slow growth with coefficients of size variation of >35 %, that has impacted P. monodon production in Thailand. A new shrimp virus, Laem-Singh virus (LSNV) was identified to be associated in ...

  18. Space and time in perceptual causality

    Directory of Open Access Journals (Sweden)

    Benjamin Straube

    2010-04-01

    Full Text Available Inferring causality is a fundamental feature of human cognition that allows us to theorize about and predict future states of the world. Michotte suggested that humans automatically perceive causality based on certain perceptual features of events. However, individual differences in judgments of perceptual causality cast doubt on Michotte’s view. To gain insights in the neural basis of individual difference in the perception of causality, our participants judged causal relationships in animations of a blue ball colliding with a red ball (a launching event while fMRI-data were acquired. Spatial continuity and temporal contiguity were varied parametrically in these stimuli. We did not find consistent brain activation differences between trials judged as caused and those judged as non-caused, making it unlikely that humans have universal instantiation of perceptual causality in the brain. However, participants were slower to respond to and showed greater neural activity for violations of causality, suggesting that humans are biased to expect causal relationships when moving objects appear to interact. Our participants demonstrated considerable individual differences in their sensitivity to spatial and temporal characteristics in perceiving causality. These qualitative differences in sensitivity to time or space in perceiving causality were instantiated in individual differences in activation of the left basal ganglia or right parietal lobe, respectively. Thus, the perception that the movement of one object causes the movement of another is triggered by elemental spatial and temporal sensitivities, which themselves are instantiated in specific distinct neural networks.

  19. The Functions of Danish Causal Conjunctions

    Directory of Open Access Journals (Sweden)

    Rita Therkelsen

    2004-01-01

    Full Text Available In the article I propose an analysis of the Danish causal conjunctions fordi, siden and for based on the framework of Danish Functional Grammar. As conjunctions they relate two clauses, and their semantics have in common that it indicates a causal relationship between the clauses. The causal conjunctions are different as far as their distribution is concerned; siden conjoins a subordinate clause and a main clause, for conjoins two main clauses, and fordi is able to do both. Methodologically I have based my analysis on these distributional properties comparing siden and fordi conjoining a subordinate and a main clause, and comparing for and fordi conjoining two main clauses, following the thesis that they would establish a causal relationship between different kinds of content. My main findings are that fordi establishes a causal relationship between the events referred to by the two clauses, and the whole utterance functions as a statement of this causal relationship. Siden presupposes such a general causal relationship between the two events and puts forward the causing event as a reason for assuming or wishing or ordering the caused event, siden thus establishes a causal relationship between an event and a speech act. For equally presupposes a general causal relationship between two events and it establishes a causal relationship between speech acts, and fordi conjoining two main clauses is able to do this too, but in this position it also maintains its event-relating ability, the interpretation depending on contextual factors.

  20. Aspectos moleculares del virus de la parvovirosis canina y sus implicaciones en la enfermedad

    OpenAIRE

    César A. Díaz R.; Jairo Jaime Correa; Víctor Julio Vera A.

    2008-01-01

    El parvovirus canino tipo 2 (CPV-2) es el agente causal de una enfermedad infecto-contagiosa que produce una gastroenteritis aguda hemorrágica que afecta a caninos jóvenes. El CPV-2 se adaptó a la especie canina por mutación del virus de la Panleucopenia felina (FPV) luego de su paso por animales silvestres como el hurón y los zorros. La alta variabilidad de la proteína viral 2 (VP2) es la causa principal del amplio rango de hospedadores y de las reacciones cruzadas entre las variantes. En la...

  1. SEROPREVALENCIA DEL VIRUS DE LA RINOTRAQUEITIS INFECCIOSA EN BOVINOS CRIOLLOS DE PARINACOCHAS, AYACUCHO.

    OpenAIRE

    Zacarías R., Erik; Práctica privada; Benito Z., Alfredo; UNMSM-FMV; Rivera G., Hermelinda; UNMSM-FMV

    2014-01-01

    El objetivo del presente estudio fue conocer la prevalencia del Virus Herpes Bovino 1 (VHB-1), agente causal de la Rinotraqueitis Infecciosa Bovina, en bovinos criollos de crianza extensiva de los distritos de Coracora, Chumpi, Puyusca y Pullo de la provincia de Parinacochas, Ayacucho. Se analizaron 469 muestras de sueros bovinos procedentes de 25 hatos para la detección de anticuerpos neutralizantes mediante la prueba de neutralización viral. El 67.6 ± 4.2% (317/469) de las muestras presentó...

  2. Genetically engineered resistance to Plum pox virus infection in herbaceous and stone fruit hosts.

    Science.gov (United States)

    Ilardi, Vincenza; Nicola-Negri, Elisa Di

    2011-01-01

    Plum pox virus (PPV), a Potyvirus, is the causal agent of sharka, the most detrimental viral disease affecting stone fruit trees. This review focuses on research carried out to obtain PPV- resistant transgenic plants and on how biotechnological strategies evolved in light of the scientific advances made during the last several years. Successful RNA silencing strategies that confer high level of resistance to strains of PPV have been developed and tested under laboratory and greenhouse conditions. Moreover, field tests showed that transgene-mediated RNA silencing was effective in protecting plum plants against aphid-mediated PPV infection. The new emerging biotechnological approaches for conferring PPV resistance are discussed.

  3. Marburg virus.

    Science.gov (United States)

    Dowdle, W R

    1976-01-01

    Marburg virus disease, which produced 20 per cent mortality when it first occured during 1967 in Germany and Yugoslavia, recently appeared again in South Africa. The source of the first outbreak was monkeys shipped from Africa; the origin of the second episode is unclear. Because distribution of the virus in nature is unknown, its threat to man cannot be readily determined. Differential laboratory diagnoses of hemorrhagic fevers should be encouraged in order to learn more about the epidemiology of these diseases and to better assess the risks which their etiologic agents may pose for attending medical personnel.

  4. Tomato chocolate spot virus, a member of a new torradovirus species that causes a necrosis-associated disease of tomato in Guatemala.

    Science.gov (United States)

    Batuman, O; Kuo, Y-W; Palmieri, M; Rojas, M R; Gilbertson, R L

    2010-06-01

    Tomatoes in Guatemala have been affected by a new disease, locally known as "mancha de chocolate" (chocolate spot). The disease is characterized by distinct necrotic spots on leaves, stems and petioles that eventually expand and cause a dieback of apical tissues. Samples from symptomatic plants tested negative for infection by tomato spotted wilt virus, tobacco streak virus, tobacco etch virus and other known tomato-infecting viruses. A virus-like agent was sap-transmitted from diseased tissue to Nicotiana benthamiana and, when graft-transmitted to tomato, this agent induced chocolate spot symptoms. This virus-like agent also was sap-transmitted to Datura stramonium and Nicotiana glutinosa, but not to a range of non-solanaceous indicator plants. Icosahedral virions approximately 28-30 nm in diameter were purified from symptomatic N. benthamiana plants. When rub-inoculated onto leaves of N. benthamiana plants, these virions induced symptoms indistinguishable from those in N. benthamiana plants infected with the sap-transmissible virus associated with chocolate spot disease. Tomatoes inoculated with sap or grafted with shoots from N. benthamiana plants infected with purified virions developed typical chocolate spot symptoms, consistent with this virus being the causal agent of the disease. Analysis of nucleic acids associated with purified virions of the chocolate-spot-associated virus, revealed a genome composed of two single-stranded RNAs of approximately 7.5 and approximately 5.1 kb. Sequence analysis of these RNAs revealed a genome organization similar to recently described torradoviruses, a new group of picorna-like viruses causing necrosis-associated diseases of tomatoes in Europe [tomato torrado virus (ToTV)] and Mexico [tomato apex necrosis virus (ToANV) and tomato marchitez virus (ToMarV)]. Thus, the approximately 7.5 kb and approximately 5.1 kb RNAs of the chocolate-spot-associated virus corresponded to the torradovirus RNA1 and RNA2, respectively; however

  5. Tomato chocolate spot virus, a member of a new torradovirus species that causes a necrosis-associated disease of tomato in Guatemala

    Science.gov (United States)

    Batuman, O.; Kuo, Y.-W.; Palmieri, M.; Rojas, M. R.

    2010-01-01

    Tomatoes in Guatemala have been affected by a new disease, locally known as “mancha de chocolate” (chocolate spot). The disease is characterized by distinct necrotic spots on leaves, stems and petioles that eventually expand and cause a dieback of apical tissues. Samples from symptomatic plants tested negative for infection by tomato spotted wilt virus, tobacco streak virus, tobacco etch virus and other known tomato-infecting viruses. A virus-like agent was sap-transmitted from diseased tissue to Nicotiana benthamiana and, when graft-transmitted to tomato, this agent induced chocolate spot symptoms. This virus-like agent also was sap-transmitted to Datura stramonium and Nicotiana glutinosa, but not to a range of non-solanaceous indicator plants. Icosahedral virions ~28–30 nm in diameter were purified from symptomatic N. benthamiana plants. When rub-inoculated onto leaves of N. benthamiana plants, these virions induced symptoms indistinguishable from those in N. benthamiana plants infected with the sap-transmissible virus associated with chocolate spot disease. Tomatoes inoculated with sap or grafted with shoots from N. benthamiana plants infected with purified virions developed typical chocolate spot symptoms, consistent with this virus being the causal agent of the disease. Analysis of nucleic acids associated with purified virions of the chocolate-spot-associated virus, revealed a genome composed of two single-stranded RNAs of ~7.5 and ~5.1 kb. Sequence analysis of these RNAs revealed a genome organization similar to recently described torradoviruses, a new group of picorna-like viruses causing necrosis-associated diseases of tomatoes in Europe [tomato torrado virus (ToTV)] and Mexico [tomato apex necrosis virus (ToANV) and tomato marchitez virus (ToMarV)]. Thus, the ~7.5 kb and ~5.1 kb RNAs of the chocolate-spot-associated virus corresponded to the torradovirus RNA1 and RNA2, respectively; however, sequence comparisons revealed 64–83% identities with

  6. Respuesta al glifosato de un aislamiento de Rhizoctonia solani agente causal del anublo de la vaina del arroz, y de cuatro aislamientos de Trichoderma, bajo condiciones in vitro In vitro response of one isolate of Rhizoctonia solani, the pathogen of the rice sheath blight and four isolates of Trichoderma to glyphosate

    Directory of Open Access Journals (Sweden)

    Vargas de Álvarez Amparo

    2002-08-01

    Full Text Available El añublo de la vaina del arroz (Orysa saliva L., cuyo agente causal es Rhizoctonia solani Kuhn, es una de las enfermedades más importantes en el cultivo del arroz en Colombia. En los cultivos de arroz con frecuencia se aplica glifosato ((ácido N-(fosfonometil glicina para controlar las malezas, particularmente el arroz rojo (O. saliva, antes de la siembra del arroz. Observaciones de campo anteriores parecían indicar relación entre el uso intensivo del glifosato y el incremento en la incidencia del añublo de la vaina del arroz. Por tanto, se propuso el presente trabajo con el fin de dilucidar los posibles efectos del glifosato sobre R. solani y Trichoderma sp., conocido éste como antagonista de R. solani. Se determinó, bajo condiciones de laboratorio, el efecto del glifosato en el crecimiento, en medio líquido y sólido PDA, de R. solani y de Trichoderma. Se encontró que la dosis más alta de glifosato sin efecto detrimental sobre R. solani, fue de 300 mg/L y la dosis más baja del herbicida que
    causó la mayor inhibición del crecimiento del hongo fue
    de 2500 mg/L. Por otra parte, no se encontró que el glifosato
    estimulara el crecimiento de R. solani. En teoría, en una aplicación comercial de glifosato de 1,5 Kg ia/ha y asperjando directamente al suelo sin vegetación, el glifosato en el suelo estaría a una concentración de 0,75 mg/Kg de suelo (suponiendo que la capa arable de una hectárea de suelo pesa 2.000.000 de Kg; por tanto, la concentración de glifosato después de una aplicación comercial, está muy por debajo de la concentración a la cual se inicia la reducción del crecimiento de R. solani. Por su parte, la respuesta de Trichoderma al glifosato fue similar a la de R. solani; además, se encontró que el glifosato no afecta la capacidad antagonista de Trichoderma sobre R. sotaní. Estos resultados no apoyan la hipótesis que el glifosato, bajo las condiciones de uso en cultivos de arroz para el control

  7. The dsRNA Virus Papaya Meleira Virus and an ssRNA Virus Are Associated with Papaya Sticky Disease.

    Directory of Open Access Journals (Sweden)

    Tathiana Ferreira Sá Antunes

    Full Text Available Papaya sticky disease, or "meleira", is one of the major diseases of papaya in Brazil and Mexico, capable of causing complete crop loss. The causal agent of sticky disease was identified as an isometric virus with a double stranded RNA (dsRNA genome, named papaya meleira virus (PMeV. In the present study, PMeV dsRNA and a second RNA band of approximately 4.5 kb, both isolated from latex of papaya plants with severe symptoms of sticky disease, were deep-sequenced. The nearly complete sequence obtained for PMeV dsRNA is 8,814 nucleotides long and contains two putative ORFs; the predicted ORF1 and ORF2 display similarity to capsid proteins and RdRp's, respectively, from mycoviruses tentatively classified in the family Totiviridae. The sequence obtained for the second RNA is 4,515 nucleotides long and contains two putative ORFs. The predicted ORFs 1 and 2 display 48% and 73% sequence identity, respectively, with the corresponding proteins of papaya virus Q, an umbravirus recently described infecting papaya in Ecuador. Viral purification in a sucrose gradient allowed separation of particles containing each RNA. Mass spectrometry analysis indicated that both PMeV and the second RNA virus (named papaya meleira virus 2, PMeV2 were encapsidated in particles formed by the protein encoded by PMeV ORF1. The presence of both PMeV and PMeV2 was confirmed in field plants showing typical symptoms of sticky disease. Interestingly, PMeV was detected alone in asymptomatic plants. Together, our results indicate that sticky disease is associated with double infection by PMeV and PMeV2.

  8. The dsRNA Virus Papaya Meleira Virus and an ssRNA Virus Are Associated with Papaya Sticky Disease

    Science.gov (United States)

    Sá Antunes, Tathiana Ferreira; Amaral, Raquel J. Vionette; Ventura, José Aires; Godinho, Marcio Tadeu; Amaral, Josiane G.; Souza, Flávia O.; Zerbini, Poliane Alfenas; Zerbini, Francisco Murilo

    2016-01-01

    Papaya sticky disease, or “meleira”, is one of the major diseases of papaya in Brazil and Mexico, capable of causing complete crop loss. The causal agent of sticky disease was identified as an isometric virus with a double stranded RNA (dsRNA) genome, named papaya meleira virus (PMeV). In the present study, PMeV dsRNA and a second RNA band of approximately 4.5 kb, both isolated from latex of papaya plants with severe symptoms of sticky disease, were deep-sequenced. The nearly complete sequence obtained for PMeV dsRNA is 8,814 nucleotides long and contains two putative ORFs; the predicted ORF1 and ORF2 display similarity to capsid proteins and RdRp's, respectively, from mycoviruses tentatively classified in the family Totiviridae. The sequence obtained for the second RNA is 4,515 nucleotides long and contains two putative ORFs. The predicted ORFs 1 and 2 display 48% and 73% sequence identity, respectively, with the corresponding proteins of papaya virus Q, an umbravirus recently described infecting papaya in Ecuador. Viral purification in a sucrose gradient allowed separation of particles containing each RNA. Mass spectrometry analysis indicated that both PMeV and the second RNA virus (named papaya meleira virus 2, PMeV2) were encapsidated in particles formed by the protein encoded by PMeV ORF1. The presence of both PMeV and PMeV2 was confirmed in field plants showing typical symptoms of sticky disease. Interestingly, PMeV was detected alone in asymptomatic plants. Together, our results indicate that sticky disease is associated with double infection by PMeV and PMeV2. PMID:27166626

  9. Linear causal modeling with structural equations

    CERN Document Server

    Mulaik, Stanley A

    2009-01-01

    Emphasizing causation as a functional relationship between variables that describe objects, Linear Causal Modeling with Structural Equations integrates a general philosophical theory of causation with structural equation modeling (SEM) that concerns the special case of linear causal relations. In addition to describing how the functional relation concept may be generalized to treat probabilistic causation, the book reviews historical treatments of causation and explores recent developments in experimental psychology on studies of the perception of causation. It looks at how to perceive causal

  10. Coxsackievirus B4 as a Causative Agent of Diabetes Mellitus Type 1: Is There a Role of Inefficiently Treated Drinking Water and Sewage in Virus Spreading?

    Science.gov (United States)

    El-Senousy, Waled M; Abdel-Moneim, Adel; Abdel-Latif, Mahmoud; El-Hefnawy, Mohamed H; Khalil, Rehab G

    2018-03-01

    This study proposed to detect the enterovirus (EV) infection in children with type 1 diabetes mellitus (T1D) and to assess the role of insufficiently treated water and sewage as sources of viral spreading. Three hundred and eighty-two serum specimens of children with T1D, one hundred serum specimens of children who did not suffer from T1D as control, and forty-eight water and sewage samples were screened for EV RNA using nested RT-PCR. The number of genome copies and infectious units of EVs in raw and treated sewage and water samples were investigated using real-time (RT)-PCR and plaque assay, respectively. T1D markers [Fasting blood glucose (FBG), HbA1c, and C-peptide], in addition to anti-Coxsackie A & B viruses (CVs A & B) IgG, were measured in control, T1D-negative EV (T1D-EV - ), and T1D-positive EV (T1D-EV + ) children specimens. The prevalence of EV genome was significantly higher in diabetic children (26.2%, 100 out of 382) than the control children (0%, 0 out of 100). FBG and HbA1c in T1D-EV - and T1D-EV + children specimens were significantly higher than those in the control group, while c-peptide in T1D-EV - and T1D-EV + children specimens was significantly lower than that in the control (n = 100; p water and treated sewage samples was 25 and 33.3%, respectively. The prevalence of EV infectious units in drinking water and treated sewage samples was 8.5 and 25%, respectively. Quantification assays were performed to assess the capabilities of both wastewater treatment plants (WWTPs) and water treatment plants (WTPs) to remove EV. The reduction of EV genome in Zenin WWTP ranged from 2 to 4 log 10 , while the reduction of EV infectious units ranged from 1 to 4 log 10 . The reduction of EV genome in El-Giza WTP ranged from 1 to 3 log 10 , while the reduction of EV infectious units ranged from 1 to 2 log 10 . This capability of reduction did not prevent the appearance of infectious EV in treated sewage and drinking water. Plaque purification was performed

  11. Causal feedbacks in climate change

    Science.gov (United States)

    van Nes, Egbert H.; Scheffer, Marten; Brovkin, Victor; Lenton, Timothy M.; Ye, Hao; Deyle, Ethan; Sugihara, George

    2015-05-01

    The statistical association between temperature and greenhouse gases over glacial cycles is well documented, but causality behind this correlation remains difficult to extract directly from the data. A time lag of CO2 behind Antarctic temperature--originally thought to hint at a driving role for temperature--is absent at the last deglaciation, but recently confirmed at the last ice age inception and the end of the earlier termination II (ref. ). We show that such variable time lags are typical for complex nonlinear systems such as the climate, prohibiting straightforward use of correlation lags to infer causation. However, an insight from dynamical systems theory now allows us to circumvent the classical challenges of unravelling causation from multivariate time series. We build on this insight to demonstrate directly from ice-core data that, over glacial-interglacial timescales, climate dynamics are largely driven by internal Earth system mechanisms, including a marked positive feedback effect from temperature variability on greenhouse-gas concentrations.

  12. Modelagem causal da astronomia antiga

    OpenAIRE

    Rodrigo Cristino de Faria

    2014-01-01

    Esta dissertação tem como objetivo apresentar a Modelagem Causal em História da Ciência (MCHC), e aplicá-la ao período da história da astronomia que vai dos primórdios ao século III AEC. Na primeira parte, exponho o método e discorro sobre algumas de suas implicações filosóficas especialmente aquelas relacionadas com a noção de avanço e historiográficas, ao mesmo tempo em que procuro inseri-lo no panorama da filosofia da ciência. Na segunda parte, que já é uma aplicação da MCHC, apresento u...

  13. [Causality in occupational oncology: the toxicologist opinion].

    Science.gov (United States)

    Lotti, Marcello

    2011-01-01

    General and individual causality in occupational oncology should be regarded as diverse and largely autonomous concepts. General causality is based upon a statement such as "the chemical is a carcinogen" and must be considered for preventive action. Individual causality implies that the statement has to be applied to a patient exposed to that chemical. Whereas cancer results from complex interactions between genes and, in broad sense, the environment, the individual causality is an empirical judgement (educated guess) based upon all information about the substance itself and the individual patient.

  14. Heterogeneous Causal Effects and Sample Selection Bias

    DEFF Research Database (Denmark)

    Breen, Richard; Choi, Seongsoo; Holm, Anders

    2015-01-01

    causal effects might vary over individuals or groups. In this paper we point out one of the under-appreciated hazards of seeking to estimate heterogeneous causal effects: conventional selection bias (that is, selection on baseline differences) can easily be mistaken for heterogeneity of causal effects....... This might lead us to find heterogeneous effects when the true effect is homogenous, or to wrongly estimate not only the magnitude but also the sign of heterogeneous effects. We apply a test for the robustness of heterogeneous causal effects in the face of varying degrees and patterns of selection bias...

  15. Neutralizing activities of human immunoglobulin derived from donors in Japan against mosquito-borne flaviviruses, Japanese encephalitis virus, West Nile virus, and dengue virus

    Directory of Open Access Journals (Sweden)

    Yunoki M

    2016-07-01

    Full Text Available Mikihiro Yunoki,1-3 Takeshi Kurosu,2 Ritsuko Kubota Koketsu,2,4 Kazuo Takahashi,5 Yoshinobu Okuno,4 Kazuyoshi Ikuta2,4 1Research and Development Division, Japan Blood Products Organization, Tokyo, 2Department of Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, 3Pathogenic Risk Evaluation, Graduate School of Veterinary Medicine, Rakuno Gakuen University, Hokkaido, 4Research and Development Division, The Research Foundation for Microbial Diseases of Osaka University, Kagawa, 5Osaka Prefectural Institute of Public Health, Osaka, Japan Abstract: Japanese encephalitis virus (JEV, West Nile virus (WNV, and dengue virus (DenV are causal agents of Japanese encephalitis, West Nile fever, and dengue fever, respectively. JEV is considered to be indigenized and widespread in Japan, whereas WNV and DenV are not indigenized in Japan. Globulin products seem to reflect the status of the donor population according to antivirus neutralization activity. However, the anti-JEV, -WNV, and -DenV neutralization activities of globulin products derived from donors in Japan have not been clarified. Furthermore, potential candidates for the development of an effective immunotherapeutic drug for encephalitis caused by JEV, WNV, or DenV have also not been identified. Therefore, the aim of this study was to determine the overall status of the donor population in Japan based on globulin products by evaluating anti-JEV, -WNV, and -DenV neutralizing activities of intravenous immunoglobulin. Overall, intravenous immunoglobulin products showed stable neutralizing activity against JEV but showed no or only weak activity against WNV or DenV. These results suggest that the epidemiological level against WNV and DenV in the donor population of Japan is still low, suggesting that these viruses are not yet indigenized. In addition, JEV vaccinations and/or infections in the donor population do not induce a cross-reactive antibody against WNV. Keywords

  16. Seed Transmission of Beet Curly Top Virus and Beet Curly Top Iran Virus in a Local Cultivar of Petunia in Iran

    Directory of Open Access Journals (Sweden)

    Ameneh Anabestani

    2017-10-01

    Full Text Available Beet curly top virus (BCTV and beet curly top Iran virus (BCTIV are known as the causal agents of curly top disease in beet and several other dicotyledonous plants in Iran. These viruses are transmitted by Circulifer species, and until now, there has been no confirmed report of their seed transmission. A percentage (38.2–78.0% of the seedlings developed from the seeds of a petunia local cultivar under insect-free conditions showed stunting, interveinal chlorosis, leaf curling, and vein swelling symptoms, and were infected by BCTV when tested by PCR. Presence of BCTV in seed extracts of petunia local cultivar was confirmed by PCR and IC-PCR, followed by sequencing. Agroinoculation of curly top free petunia plants with a BCTV infectious clone resulted in BCTV infection of plants and their developed seeds. These results show the seed infection and transmission of BCTV in a local cultivar of petunia. Similar experiments performed with BCTIV showed that this virus is also seed transmissible in the same cultivar of petunia, although with a lower rate (8.8–18.5%. Seed transmission of curly top viruses may have significant implications in the epidemiology of these viruses.

  17. Novel host-related virulence factors are encoded by squirrelpox virus, the main causative agent of epidemic disease in red squirrels in the UK.

    Directory of Open Access Journals (Sweden)

    Alistair C Darby

    Full Text Available Squirrelpox virus (SQPV shows little evidence for morbidity or mortality in North American grey squirrels (Sciurus carolinensis, in which the virus is endemic. However, more recently the virus has emerged to cause epidemics with high mortality in Eurasian red squirrels (S. vulgaris in Great Britain, which are now threatened. Here we report the genome sequence of SQPV. Comparison with other Poxviridae revealed a core set of poxvirus genes, the phylogeny of which showed SQPV to be in a new Chordopoxvirus subfamily between the Molluscipoxviruses and Parapoxviruses. A number of SQPV genes were related to virulence, including three major histocomaptibility class I homologs, and one CD47 homolog. In addition, a novel potential virulence factor showing homology to mammalian oligoadenylate synthetase (OAS was identified. This family of proteins normally causes activation of an endoribonuclease (RNaseL within infected cells. The putative function of this novel SQPV protein was predicted in silico.

  18. All Microorganisms Must Die, But How Many Get Lysed By Viruses? - Approaches to Assessing the Significance of Nano-Sized Agents of Mortality Among Communities of Phytoplankton

    Science.gov (United States)

    Fobbe, D. J.; Simmons, L. J.; Berges, J. A.

    2016-02-01

    Work with laboratory cultures and phytoplankton blooms has shown the potential for viruses to be dominant causes of mortality, but viral effects on phytoplankton community dynamics are less clear and more difficult to assess. Reasons for this include that viral-host relationships are difficult to establish and ongoing 'arms-races' of biological defenses and adaptations over short time scales obscure what is happening. We approached the problem using a small, well-studied urban pond as a model system, and monitoring phytoplankton and viral dynamics weekly through two years using flow cytometry. Flow cytometry allowed us to distinguish and enumerate phytoplankton groups and with cell staining, estimate proportions of living and dead cells. We adapted published methods for counting viruses using flow cytometry, and validated them against epifluorescent techniques. Modifications included: pre-filtration of samples through GF/F filters, fixation with glutaraldehyde, addition of EDTA prior to staining with SYBR Green©, and use of ultra-pure water as a diluent to obtain optimum concentrations. Viral counts ranged from 106 per ml (under ice in winter) to over 109 per ml (as summer phytoplankton blooms peaked). Viral abundances exceeded phytoplankton by up to three orders of magnitude. We could distinguish five groups of viruses based on SYBR Greenfluorescence and side scatter, and these showed seasonal changes. While many of these viruses probably infected heterotrophic bacteria, in some periods increases in viruses correlated with decline of phytoplankton groups, when changes in environmental parameters (e.g. temperature, irradiance, nutrients) were not apparent. Best correlations were found within 6 µm and smaller size fractions of phytoplankton versus larger groups. To examine links between viral lysis and phytoplankton, experiments are currently being conducted concentrating viruses and incubating them with natural communities of phytoplankton to monitor infection

  19. Causal ubiquity in quantum physics. A superluminal and local-causal physical ontology

    Energy Technology Data Exchange (ETDEWEB)

    Neelamkavil, Raphael

    2014-07-01

    A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly [non-causal] processes, something exists processually in extension-motion, between the causal and the [non-causal]. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That is, the QM world is sub-luminally, luminally and superluminally local-causal throughout, and the Law of Causality is ubiquitous in the micro-world. Thus, ''probabilistic causality'' is a merely epistemic term.

  20. The gut microbiota and obesity: from correlation to causality.

    Science.gov (United States)

    Zhao, Liping

    2013-09-01

    The gut microbiota has been linked with chronic diseases such as obesity in humans. However, the demonstration of causality between constituents of the microbiota and specific diseases remains an important challenge in the field. In this Opinion article, using Koch's postulates as a conceptual framework, I explore the chain of causation from alterations in the gut microbiota, particularly of the endotoxin-producing members, to the development of obesity in both rodents and humans. I then propose a strategy for identifying the causative agents of obesity in the human microbiota through a combination of microbiome-wide association studies, mechanistic analysis of host responses and the reproduction of diseases in gnotobiotic animals.

  1. Complete genome sequences of two new virus isolates associated with cotton blue disease resistance breaking in Brazil.

    Science.gov (United States)

    da Silva, Anna Karoline Fausto; Romanel, Elisson; Silva, Tatiane da F; Castilhos, Yamá; Schrago, Carlos G; Galbieri, Rafael; Bélot, Jean-Louis; Vaslin, Maite F S

    2015-05-01

    Since 2006, Brazilian cotton (Gossypium hirsutum) crops planted with cultivars that are resistant to cotton blue disease have developed a new disease termed "atypical" cotton blue disease or atypical vein mosaic disease. Here, we describe the complete genomes of two virus isolates associated with this disease. The new virus isolates, called CLRDV-Acr3 and CLRDV-IMA2, were found to have a high degree of nucleotide and amino acid sequence similarity to previously described isolates of cotton leafroll dwarf virus, the causal agent of cotton blue disease. However, their P0 proteins were 86.1 % identical. These results show that this new disease is caused by a new CLRDV genotype that seems to have acquired the ability to overcome cotton blue disease resistance.

  2. A qualitative study evaluating causality attribution for serious adverse events during early phase oncology clinical trials.

    Science.gov (United States)

    Mukherjee, Som D; Coombes, Megan E; Levine, Mitch; Cosby, Jarold; Kowaleski, Brenda; Arnold, Andrew

    2011-10-01

    In early phase oncology trials, novel targeted therapies are increasingly being tested in combination with traditional agents creating greater potential for enhanced and new toxicities. When a patient experiences a serious adverse event (SAE), investigators must determine whether the event is attributable to the investigational drug or not. This study seeks to understand the clinical reasoning, tools used and challenges faced by the researchers who assign causality to SAE's. Thirty-two semi-structured interviews were conducted with medical oncologists and trial coordinators at six Canadian academic cancer centres. Interviews were recorded and transcribed verbatim. Individual interview content analysis was followed by thematic analysis across the interview set. Our study found that causality assessment tends to be a rather complex process, often without complete clinical and investigational data at hand. Researchers described using a common processing strategy whereby they gather pertinent information, eliminate alternative explanations, and consider whether or not the study drug resulted in the SAE. Many of the interviewed participants voiced concern that causality assessments are often conducted quickly and tend to be highly subjective. Many participants were unable to identify any useful tools to help in assigning causality and welcomed more objectivity in the overall process. Attributing causality to SAE's is a complex process. Clinical trial researchers apply a logical system of reasoning, but feel that the current method of assigning causality could be improved. Based on these findings, future research involving the development of a new causality assessment tool specifically for use in early phase oncology clinical trials may be useful.

  3. Causal Systems Categories: Differences in Novice and Expert Categorization of Causal Phenomena

    Science.gov (United States)

    Rottman, Benjamin M.; Gentner, Dedre; Goldwater, Micah B.

    2012-01-01

    We investigated the understanding of causal systems categories--categories defined by common causal structure rather than by common domain content--among college students. We asked students who were either novices or experts in the physical sciences to sort descriptions of real-world phenomena that varied in their causal structure (e.g., negative…

  4. Direct-acting Antiviral Agents Resistance-associated Polymorphisms in Chinese Treatment-naÏve Patients Infected with Genotype 1b Hepatitis C Virus

    Directory of Open Access Journals (Sweden)

    Ye Wang

    2015-01-01

    Conclusions: The majority of genotype 1b CHC patients in China present a virus population carrying HCV DAAs RAVs. Pretreatment sequencing of HCV genome might need to be performed when patients infected with GT1b HCV receiving DAAs-containing regimens in China. Population sequencing would be quite quantified for the work.

  5. Causal random geometry from stochastic quantization

    DEFF Research Database (Denmark)

    Ambjørn, Jan; Loll, R.; Westra, W.

    2010-01-01

     in this short note we review a recently found formulation of two-dimensional causal quantum gravity defined through Causal Dynamical Triangulations and stochastic quantization. This procedure enables one to extract the nonperturbative quantum Hamiltonian of the random surface model including...... the sum over topologies. Interestingly, the generally fictitious stochastic time corresponds to proper time on the geometries...

  6. Causal random geometry from stochastic quantization

    NARCIS (Netherlands)

    Ambjørn, J.; Loll, R.|info:eu-repo/dai/nl/304830720; Westra, W.|info:eu-repo/dai/nl/304832073; Zohren, S.

    2010-01-01

    In this short note we review a recently found formulation of two-dimensional causal quantum gravity defined through Causal Dynamical Triangulations and stochastic quantization. This procedure enables one to extract the nonperturbative quantum Hamiltonian of the random surface model including the sum

  7. mediation: R Package for Causal Mediation Analysis

    Directory of Open Access Journals (Sweden)

    Dustin Tingley

    2014-09-01

    Full Text Available In this paper, we describe the R package mediation for conducting causal mediation analysis in applied empirical research. In many scientific disciplines, the goal of researchers is not only estimating causal effects of a treatment but also understanding the process in which the treatment causally affects the outcome. Causal mediation analysis is frequently used to assess potential causal mechanisms. The mediation package implements a comprehensive suite of statistical tools for conducting such an analysis. The package is organized into two distinct approaches. Using the model-based approach, researchers can estimate causal mediation effects and conduct sensitivity analysis under the standard research design. Furthermore, the design-based approach provides several analysis tools that are applicable under different experimental designs. This approach requires weaker assumptions than the model-based approach. We also implement a statistical method for dealing with multiple (causally dependent mediators, which are often encountered in practice. Finally, the package also offers a methodology for assessing causal mediation in the presence of treatment noncompliance, a common problem in randomized trials.

  8. Updating during Reading Comprehension: Why Causality Matters

    Science.gov (United States)

    Kendeou, Panayiota; Smith, Emily R.; O'Brien, Edward J.

    2013-01-01

    The present set of 7 experiments systematically examined the effectiveness of adding causal explanations to simple refutations in reducing or eliminating the impact of outdated information on subsequent comprehension. The addition of a single causal-explanation sentence to a refutation was sufficient to eliminate any measurable disruption in…

  9. Nonlinear Granger Causality: Guidelines for Multivariate Analysis

    NARCIS (Netherlands)

    Diks, C.; Wolski, M.

    2013-01-01

    In this paper we propose an extension of the nonparametric Granger causality test, originally introduced by Diks and Panchenko [2006. A new statistic and practical guidelines for nonparametric Granger causality testing. Journal of Economic Dynamics \\& Control 30, 1647-1669]. We show that the basic

  10. Essays on Causal Inference for Public Policy

    Science.gov (United States)

    Zajonc, Tristan

    2012-01-01

    Effective policymaking requires understanding the causal effects of competing proposals. Relevant causal quantities include proposals' expected effect on different groups of recipients, the impact of policies over time, the potential trade-offs between competing objectives, and, ultimately, the optimal policy. This dissertation studies causal…

  11. Determining Directional Dependency in Causal Associations

    Science.gov (United States)

    Pornprasertmanit, Sunthud; Little, Todd D.

    2012-01-01

    Directional dependency is a method to determine the likely causal direction of effect between two variables. This article aims to critique and improve upon the use of directional dependency as a technique to infer causal associations. We comment on several issues raised by von Eye and DeShon (2012), including: encouraging the use of the signs of…

  12. Laem-Singh Virus: A Probable Etiological Agent Associated with Monodon Slow Growth Syndrome in Farmed Black Tiger Shrimp (Penaeus monodon).

    Science.gov (United States)

    Poornima, M; Seetang-Nun, Y; Alavandi, S V; Dayal, J Syama

    2012-09-01

    Among the emerging diseases in shrimp aquaculture, monodon slow growth syndrome (MSGS) is a major concern in South and Southeast Asia. Shrimp farming in Thailand was severely affected during 2000-2002 due to MSGS, which caused an economic loss, of about US$ 300 million. MSGS is characterized by abnormally slow growth with coefficients of size variation of >35 %, that has impacted P. monodon production in Thailand. A new shrimp virus, Laem-Singh virus (LSNV) was identified to be associated in MSGS affected shrimp. LSNV a RNA virus of about 25 nm diameter is phylogenetically related to the insect-borne viruses in the families Barnaviridae, Tymoviridae and Sobemoviridae an important histopathological observation is exclusively noticed in growth-retarded shrimp. The LSNV infections have been confirmed in various organs of infected shrimp such as lymphoid organ, gills and nervous tissues by various diagnostic techniques such as reverse transcription polymerase chain reaction (RT-PCR), in situ hybridization, quantitative real-time RT-PCR and reverse transcription loop-mediated isothermal amplification combined with a lateral flow dipstick (RT-LAMP-LFD) and these tools are available for the diagnosis of LSNV. Recently, an integrase containing element has been identified in absolute association with LSNV in stunted growth shrimp. The transmission of LSNV through horizontal and vertical routes has been experimentally demonstrated. The known natural host-range of LSNV includes P. monodon and other penaeid shrimp. The putative RdRp gene involved in replication of LSNV was targeted for dsRNA-mediated gene silencing and appeared to be effective in a dose-dependent manner. Since the discovery of LSNV in 2006 in Thailand, it has been added to the list of viruses to be excluded from domesticated specific pathogen-free stocks of P. monodon and it has been recommended that shrimp farmers avoid stocking post larvae positive for LSNV to prevent MSGS in their farms.

  13. Quantum-coherent mixtures of causal relations

    Science.gov (United States)

    MacLean, Jean-Philippe W.; Ried, Katja; Spekkens, Robert W.; Resch, Kevin J.

    2017-01-01

    Understanding the causal influences that hold among parts of a system is critical both to explaining that system's natural behaviour and to controlling it through targeted interventions. In a quantum world, understanding causal relations is equally important, but the set of possibilities is far richer. The two basic ways in which a pair of time-ordered quantum systems may be causally related are by a cause-effect mechanism or by a common-cause acting on both. Here we show a coherent mixture of these two possibilities. We realize this nonclassical causal relation in a quantum optics experiment and derive a set of criteria for witnessing the coherence based on a quantum version of Berkson's effect, whereby two independent causes can become correlated on observation of their common effect. The interplay of causality and quantum theory lies at the heart of challenging foundational puzzles, including Bell's theorem and the search for quantum gravity. PMID:28485394

  14. Statin (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor-based therapy for hepatitis C virus (HCV infection-related diseases in the era of direct-acting antiviral agents [version 3; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Sara Sobhy Kishta

    2017-01-01

    Full Text Available Recent improvements have been made in the treatment of hepatitis C virus (HCV infection with the introduction of direct-acting antiviral agents (DAAs. However, despite successful viral clearance, many patients continue to have HCV-related disease progression. Therefore, new treatments must be developed to achieve viral clearance and prevent the risk of HCV-related diseases. In particular, the use of pitavastatin together with DAAs may improve the antiviral efficacy as well as decrease the progression of liver fibrosis and the incidence of HCV-related hepatocellular carcinoma. To investigate the management methods for HCV-related diseases using pitavastatin and DAAs, clinical trials should be undertaken. However, concerns have been raised about potential drug interactions between statins and DAAs. Therefore, pre-clinical trials using a replicon system, human hepatocyte-like cells, human neurons and human cardiomyocytes from human-induced pluripotent stem cells should be conducted. Based on these pre-clinical trials, an optimal direct-acting antiviral agent could be selected for combination with pitavastatin and DAAs. Following the pre-clinical trial, the combination of pitavastatin and the optimal direct-acting antiviral agent should be compared to other combinations of DAAs (e.g., sofosbuvir and velpatasvir according to the antiviral effect on HCV infection, HCV-related diseases and cost-effectiveness.

  15. Causal ubiquity in quantum physics a superluminal and local-causal physical ontology

    CERN Document Server

    Neelamkavil, Raphael

    2014-01-01

    A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly non-causal processes, something exists processually in extension-motion, between the causal and the non-causal. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That

  16. Summarizing Simulation Results using Causally-relevant States

    Science.gov (United States)

    Parikh, Nidhi; Marathe, Madhav; Swarup, Samarth

    2016-01-01

    As increasingly large-scale multiagent simulations are being implemented, new methods are becoming necessary to make sense of the results of these simulations. Even concisely summarizing the results of a given simulation run is a challenge. Here we pose this as the problem of simulation summarization: how to extract the causally-relevant descriptions of the trajectories of the agents in the simulation. We present a simple algorithm to compress agent trajectories through state space by identifying the state transitions which are relevant to determining the distribution of outcomes at the end of the simulation. We present a toy-example to illustrate the working of the algorithm, and then apply it to a complex simulation of a major disaster in an urban area. PMID:28042620

  17. The Role of Causal and Intentional Judgments in Moral Reasoning in Individuals with High Functioning Autism

    Science.gov (United States)

    Buon, Marine; Dupoux, Emmanuel; Jacob, Pierre; Chaste, Pauline; Leboyer, Marion; Zalla, Tiziana

    2013-01-01

    In the present study, we investigated the ability to assign moral responsibility and punishment in adults with high functioning autism or Asperger Syndrome (HFA/AS), using non-verbal cartoons depicting an aggression, an accidental harm or a mere coincidence. Participants were asked to evaluate the agent's causal and intentional roles, his…

  18. Quantum correlations with no causal order.

    Science.gov (United States)

    Oreshkov, Ognyan; Costa, Fabio; Brukner, Caslav

    2012-01-01

    The idea that events obey a definite causal order is deeply rooted in our understanding of the world and at the basis of the very notion of time. But where does causal order come from, and is it a necessary property of nature? Here, we address these questions from the standpoint of quantum mechanics in a new framework for multipartite correlations that does not assume a pre-defined global causal structure but only the validity of quantum mechanics locally. All known situations that respect causal order, including space-like and time-like separated experiments, are captured by this framework in a unified way. Surprisingly, we find correlations that cannot be understood in terms of definite causal order. These correlations violate a 'causal inequality' that is satisfied by all space-like and time-like correlations. We further show that in a classical limit causal order always arises, which suggests that space-time may emerge from a more fundamental structure in a quantum-to-classical transition.

  19. THE EPIDEMIOLOGY OF RESPIRATORY SYNCYTIAL VIRUS (RSV ...

    African Journals Online (AJOL)

    These include maternal age and education leve1,6 overcrowding,'malnutrition,' indoor air pollution' and parental smoking.to Viral agents are recovered more frequently than bacterial agents from ARl cases and the most frequent virus detected is respiratory syncytial virus. (RSV).to.ll-1< The predominant bacterial agents are ...

  20. Oncolytic viruses in cancer therapy.

    Science.gov (United States)

    Vähä-Koskela, Markus J V; Heikkilä, Jari E; Hinkkanen, Ari E

    2007-09-08

    Oncolytic virotherapy is a promising form of gene therapy for cancer, employing nature's own agents to find and destroy malignant cells. The purpose of this review is to provide an introduction to this very topical field of research and to point out some of the current observations, insights and ideas circulating in the literature. We have strived to acknowledge as many different oncolytic viruses as possible to give a broader picture of targeting cancer using viruses. Some of the newest additions to the panel of oncolytic viruses include the avian adenovirus, foamy virus, myxoma virus, yaba-like disease virus, echovirus type 1, bovine herpesvirus 4, Saimiri virus, feline panleukopenia virus, Sendai virus and the non-human coronaviruses. Although promising, virotherapy still faces many obstacles that need to be addressed, including the emergence of virus-resistant tumor cells.

  1. Causality and Time in Historical Institutionalism

    DEFF Research Database (Denmark)

    Mahoney, James; Mohamedali, Khairunnisa; Nguyen, Christoph

    2016-01-01

    This chapter explores the dual concern with causality and time in historical institutionalism using a graphical approach. The analysis focuses on three concepts that are central to this field: critical junctures, gradual change, and path dependence. The analysis makes explicit and formal the logic...... underlying studies that use these “causal-temporal” concepts. The chapter shows visually how causality and temporality are linked to one another in varying ways depending on the particular pattern of change. The chapter provides new tools for describing and understanding change in historical- institutional...

  2. Dual Causality and the Autonomy of Biology.

    Science.gov (United States)

    Bock, Walter J

    2017-03-01

    Ernst Mayr's concept of dual causality in biology with the two forms of causes (proximate and ultimate) continues to provide an essential foundation for the philosophy of biology. They are equivalent to functional (=proximate) and evolutionary (=ultimate) causes with both required for full biological explanations. The natural sciences can be classified into nomological, historical nomological and historical dual causality, the last including only biology. Because evolutionary causality is unique to biology and must be included for all complete biological explanations, biology is autonomous from the physical sciences.

  3. Causal Reasoning and Developmental Change over the Preschool Years.

    Science.gov (United States)

    Bullock, Merry

    1985-01-01

    Explores implications of two cognitive development perspectives for characterizing ontogeny of causal reasoning. Reviews literature on causal reasoning in the preschool years and concludes that the hypothesis of an invariant causal scheme is only partially correct. (Author/SO)

  4. Characterization of a novel single-stranded RNA mycovirus related to invertebrate viruses from the plant pathogen Verticillium dahliae.

    Science.gov (United States)

    Cañizares, M Carmen; López-Escudero, Francisco J; Pérez-Artés, Encarnación; García-Pedrajas, María D

    2017-11-16

    Fungal viruses, also known as mycoviruses, are widespread in all major groups of fungi. Mycoviruses from plant pathogens can reduce the virulence of their host fungus and have therefore potential as biological control agents. This has spurred the identification of novel mycoviruses in plant pathogens, research which is greatly contributing to our understanding of these organisms. In this work, we report the characterization of a novel monopartite mycovirus from Verticillium dahliae, the main causal agent of Verticillium wilt. This novel mycovirus, which we termed Verticillium dahliae RNA virus 1 (VdRV1), was identified in three different isolates of V. dahliae collected in olive growing areas of the Guadalquivir valley, southern Spain. We determined that the VdRV1 genome is a positive (+) single-stranded (ss) RNA, 2631 nucleotides in length, containing two open reading frames. VdRV1 showed few similarities with known mycoviruses, only with a group of unassigned (+) ssRNA mycoviruses which are related to plant viruses classified within the family Tombusviridae. However, phylogenetic analysis revealed that VdRV1 and the unassigned (+) ssRNA mycoviruses have a closer relationship with recently reported invertebrate viruses. This result indicates that as more viral sequences become available, the relationships of mycoviruses with viruses from other hosts should be reexamined. Additionally, the work supports the hypothesis of a heterogeneous origin for mycoviruses.

  5. Use of PCR-based assays for the detection of the adventitious agent porcine circovirus type 1 (PCV1) in vaccines, and for confirming the identity of cell substrates and viruses used in vaccine production.

    Science.gov (United States)

    Kumar, Deepak; Beach, Nathan M; Meng, Xiang-Jin; Hegde, Nagendra R

    2012-01-01

    Safety and quality are important issues for vaccines. Whereas reversion to virulence poses a safety risk with live attenuated vaccines, the potential for the presence of adventitious agents is also an issue of vaccine quality. The recent detection or porcine circovirus type 1 (PCV1) in human vaccines has further highlighted the importance of quality control in vaccine production. The purpose of this study was to use a novel conventional PCR to detect PCV1, and subsequently screen materials used in the manufacture of vaccines at Bharat Biotech International Limited, India. The genome or gene fragments of PCV1 were not detected in any of the vaccines and materials tested, including the live attenuated rotavirus vaccine candidate ROTAVAC(®). Further, the identity of the cells and the viruses used as starting materials in the manufacture of these vaccines was confirmed by species-specific PCR or virus-specific RT-PCR, and no cross-contamination was detected in any case. The methods can be applied for regular in-house quality control screening of raw materials and seeds/banks, as well as formulated vaccines. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Causality and the Semantics of Provenance

    Directory of Open Access Journals (Sweden)

    James Cheney

    2010-06-01

    Full Text Available Provenance, or information about the sources, derivation, custody or history of data, has been studied recently in a number of contexts, including databases, scientific workflows and the Semantic Web. Many provenance mechanisms have been developed, motivated by informal notions such as influence, dependence, explanation and causality. However, there has been little study of whether these mechanisms formally satisfy appropriate policies or even how to formalize relevant motivating concepts such as causality. We contend that mathematical models of these concepts are needed to justify and compare provenance techniques. In this paper we review a theory of causality based on structural models that has been developed in artificial intelligence, and describe work in progress on using causality to give a semantics to provenance graphs.

  7. Special Relativity, Causality and Quantum Mechanics-2

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 9. Special Relativity, Causality and Quantum Mechanics - 2. Guruprasad Kar Samir Kunkri Sujit K Choudhary. General Article Volume 11 Issue 9 September 2006 pp 43-54 ...

  8. Unveiling causal activity of complex networks

    Science.gov (United States)

    Williams-García, Rashid V.; Beggs, John M.; Ortiz, Gerardo

    2017-07-01

    We introduce a novel tool for analyzing complex network dynamics, allowing for cascades of causally-related events, which we call causal webs (c-webs), to be separated from other non-causally-related events. This tool shows that traditionally-conceived avalanches may contain mixtures of spatially-distinct but temporally-overlapping cascades of events, and dynamical disorder or noise. In contrast, c-webs separate these components, unveiling previously hidden features of the network and dynamics. We apply our method to mouse cortical data with resulting statistics which demonstrate for the first time that neuronal avalanches are not merely composed of causally-related events. The original version of this article was uploaded to the arXiv on March 17th, 2016 [1].

  9. Causality, teleology and explanation in social sciences

    OpenAIRE

    Crespo, Ricardo F

    2016-01-01

    Causality and explanation are hot topics in the contemporary philosophy of natural and social sciences. The dissatisfaction with some “classical” accounts of scientific explanation (such as the deductive-nomological or covering law model, or the inductive and deductive statistical explanation) leads philosophers of science to probe the possibilities of causal explanations. However, instead of unanimous notions on causation and explanation, a plethora of concepts emerged.2 This ...

  10. Selective anti-herpesvirus agents.

    Science.gov (United States)

    De Clercq, Erik

    2013-01-23

    This review article focuses on the anti-herpesvirus agents effective against herpes simplex virus, varicella-zoster virus and cytomegalovirus, which have either been licensed for clinical use (idoxuridine, trifluridine, brivudin, acyclovir, valaciclovir, valganciclovir, famciclovir and foscarnet) or are under clinical development (CMX001 [the hexadecyloxypropyl prodrug of cidofovir], the helicase-primase inhibitor BAY 57-1293 [now referred to as AIC316], FV-100 [the valine ester of Cf 1743] and the terminase inhibitor letermovir [AIC246]).

  11. Causality violation, gravitational shockwaves and UV completion

    Energy Technology Data Exchange (ETDEWEB)

    Hollowood, Timothy J.; Shore, Graham M. [Department of Physics, Swansea University,Swansea, SA2 8PP (United Kingdom)

    2016-03-18

    The effective actions describing the low-energy dynamics of QFTs involving gravity generically exhibit causality violations. These may take the form of superluminal propagation or Shapiro time advances and allow the construction of “time machines”, i.e. spacetimes admitting closed non-spacelike curves. Here, we discuss critically whether such causality violations may be used as a criterion to identify unphysical effective actions or whether, and how, causality problems may be resolved by embedding the action in a fundamental, UV complete QFT. We study in detail the case of photon scattering in an Aichelburg-Sexl gravitational shockwave background and calculate the phase shifts in QED for all energies, demonstrating their smooth interpolation from the causality-violating effective action values at low-energy to their manifestly causal high-energy limits. At low energies, these phase shifts may be interpreted as backwards-in-time coordinate jumps as the photon encounters the shock wavefront, and we illustrate how the resulting causality problems emerge and are resolved in a two-shockwave time machine scenario. The implications of our results for ultra-high (Planck) energy scattering, in which graviton exchange is modelled by the shockwave background, are highlighted.

  12. Kant on causal laws and powers.

    Science.gov (United States)

    Henschen, Tobias

    2014-12-01

    The aim of the paper is threefold. Its first aim is to defend Eric Watkins's claim that for Kant, a cause is not an event but a causal power: a power that is borne by a substance, and that, when active, brings about its effect, i.e. a change of the states of another substance, by generating a continuous flow of intermediate states of that substance. The second aim of the paper is to argue against Watkins that the Kantian concept of causal power is not the pre-critical concept of real ground but the category of causality, and that Kant holds with Hume that causal laws cannot be inferred non-inductively (that he accordingly has no intention to show in the Second analogy or elsewhere that events fall under causal laws). The third aim of the paper is to compare the Kantian position on causality with central tenets of contemporary powers ontology: it argues that unlike the variants endorsed by contemporary powers theorists, the Kantian variants of these tenets are resistant to objections that neo-Humeans raise to these tenets.

  13. Transitive reasoning distorts induction in causal chains.

    Science.gov (United States)

    von Sydow, Momme; Hagmayer, York; Meder, Björn

    2016-04-01

    A probabilistic causal chain A→B→C may intuitively appear to be transitive: If A probabilistically causes B, and B probabilistically causes C, A probabilistically causes C. However, probabilistic causal relations can only guaranteed to be transitive if the so-called Markov condition holds. In two experiments, we examined how people make probabilistic judgments about indirect relationships A→C in causal chains A→B→C that violate the Markov condition. We hypothesized that participants would make transitive inferences in accordance with the Markov condition although they were presented with counterevidence showing intransitive data. For instance, participants were successively presented with data entailing positive dependencies A→B and B→C. At the same time, the data entailed that A and C were statistically independent. The results of two experiments show that transitive reasoning via a mediating event B influenced and distorted the induction of the indirect relation between A and C. Participants' judgments were affected by an interaction of transitive, causal-model-based inferences and the observed data. Our findings support the idea that people tend to chain individual causal relations into mental causal chains that obey the Markov condition and thus allow for transitive reasoning, even if the observed data entail that such inferences are not warranted.

  14. Manipulating Morality: Third-Party Intentions Alter Moral Judgments by Changing Causal Reasoning.

    Science.gov (United States)

    Phillips, Jonathan; Shaw, Alex

    2015-08-01

    The present studies investigate how the intentions of third parties influence judgments of moral responsibility for other agents who commit immoral acts. Using cases in which an agent acts under some situational constraint brought about by a third party, we ask whether the agent is blamed less for the immoral act when the third party intended for that act to occur. Study 1 demonstrates that third-party intentions do influence judgments of blame. Study 2 finds that third-party intentions only influence moral judgments when the agent's actions precisely match the third party's intention. Study 3 shows that this effect arises from changes in participants' causal perception that the third party was controlling the agent. Studies 4 and 5, respectively, show that the effect cannot be explained by changes in the distribution of blame or perceived differences in situational constraint faced by the agent. © 2014 Cognitive Science Society, Inc.

  15. Human Subtilisin Kexin Isozyme-1 (SKI-1)/Site-1 Protease (S1P) regulates cytoplasmic lipid droplet abundance: A potential target for indirect-acting anti-dengue virus agents.

    Science.gov (United States)

    Hyrina, Anastasia; Meng, Fanrui; McArthur, Steven J; Eivemark, Sharlene; Nabi, Ivan R; Jean, François

    2017-01-01

    Viral hijacking and manipulation of host-cell biosynthetic pathways by human enveloped viruses are shared molecular events essential for the viral lifecycle. For Flaviviridae members such as hepatitis C virus and dengue virus (DENV), one of the key subsets of cellular pathways that undergo manipulation is the lipid metabolic pathways, underlining the importance of cellular lipids and, in particular, lipid droplets (LDs) in viral infection. Here, we hypothesize that targeting cellular enzymes that act as key regulators of lipid homeostasis and LD formation could represent a powerful approach to developing a novel class of broad-spectrum antivirals against infection associated with all DENV serotypes (1-4) circulating around the world. Using PF-429242, an active-site-directed inhibitor of SKI-1/S1P, we demonstrate that inhibition of SKI-1/S1P enzymatic activity in human hepatoma Huh-7.5.1 cells results in a robust reduction of the LD numbers and LD-positive areas and provides a means of effectively inhibiting infection by DENV (1-4). Pre-treatment of Huh-7.5.1 cells with PF-429242 results in a dose-dependent inhibition of DENV infection [median inhibitory dose (EC50) = 1.2 microM; median cytotoxic dose (CC50) = 81 microM; selectivity index (SI) = 68)] and a ~3-log decrease in DENV-2 titer with 20 microM of PF-429242. Post-treatment of DENV-2 infected Huh-7.5.1 cells with PF-429242 does not affect viral RNA abundance, but it does compromise the assembly and/or release of infectious virus particles. PF-429242 antiviral activity is reversed by exogenous oleic acid, which acts as an inducer of LD formation in PF-429242-treated and non-treated control cells. Collectively, our results demonstrate that human SKI-1/S1P is a potential target for indirect-acting pan-serotypic anti-DENV agents and reveal new therapeutic opportunities associated with the use of lipid-modulating drugs for controlling DENV infection.

  16. Natural co-infection of Solanum tuberosum crops by the Potato yellow vein virus and potyvirus in Colombia

    Directory of Open Access Journals (Sweden)

    Angela Villamil-Garzón

    2014-08-01

    Full Text Available The Potato yellow vein virus (PYVV, a Crinivirus with an RNA tripartite genome, is the causal agent of the potato yellow vein disease, reported in Colombian since 1950, with yield reductions of up to 50%. Co-infection of two or more viruses is common in nature and can be associated with differences in virus accumulation and symptom expression. No evidence of mixed infection between PYVV and other viruses has been reported. In this study, eight plants showing yellowing PYVV symptoms: four Solanum tuberosum Group Phureja (P and four Group Andigena (A, were collected in Cundinamarca, Colombia to detect mixed infection in the isolates using next generation sequencing (NGS. The Potato virus Y (PVY complete genome (similar to N strain and the Potato virus V (PVV partial genomes were detected using NGS and re-confirmed by RT-PCR. Preliminary field screening in a large sample showed that PYVV and PVY co-infect potato plants with a prevalence of 21% within the P group and 23% within the A group. This is the first report of co-infection of PYVV and potyvirus in Colombia and with the use of NGS. Considering that potyviruses enhance symptom severity and/or yield reductions in mixed infections, our results may be relevant for disease diagnosis, breeding programs and tuber certification.

  17. Ebola Virus and Marburg Virus

    Science.gov (United States)

    Ebola virus and Marburg virus Overview Ebola virus and Marburg virus are related viruses that cause hemorrhagic fevers — illnesses marked by severe bleeding (hemorrhage), organ failure and, in many ...

  18. Aspectos generales sobre la estructura y función de las proteínas codificadas por el virus del Papiloma Humano

    OpenAIRE

    Jorge Félix Beltrán Lissabet

    2014-01-01

    El virus del Papiloma Humano (VPH) es el agente causal de una de las infecciones de transmisión sexual más propagadas en todo el mundo que afecta principalmente a la población femenina. L os mecanismos moleculares por los que el VPH establece las infecciones son muy complejos y las vías por las que lleva a cabo su ciclo infectivo, están sometidas a una regulación compleja del genoma viral, el cual contiene ocho marcos abiertos de lectura (M AL) que codifican una serie de proteínas clave (E6, ...

  19. ESTUDIO DE LA INTERACCIÓN DIFERENCIAL ENTRE AISLADOS DEL VIRUS DE LA TRISTEZA DE LOS CÍTRICOS (CTV) Y SUS HUÉSPEDES

    OpenAIRE

    GÓMEZ MUÑOZ, NEUS

    2018-01-01

    La tristeza es la enfermedad viral más grave del cultivo de los cítricos y su agente causal es el virus de la tristeza de los cí­tricos (CTV). CTV induce uno o más de los siguientes sí­ndromes: I) decaimiento y muerte de los naranjos dulces (ND), pomelos y mandarinos injertados sobre el patrón naranjo amargo (NA), sí­ndrome conocido como "tristeza", II) enanismo, acanaladuras en la madera y fruta de pequeño calibre (stem pitting, SP), y III) enanismo y amarillamiento de plantas de semilla d...

  20. The Relevance of Causal Social Construction

    Directory of Open Access Journals (Sweden)

    Marques Teresa

    2017-02-01

    Full Text Available Social constructionist claims are surprising and interesting when they entail that presumably natural kinds are in fact socially constructed. The claims are interesting because of their theoretical and political importance. Authors like Díaz-León argue that constitutive social construction is more relevant for achieving social justice than causal social construction. This paper challenges this claim. Assuming there are socially salient groups that are discriminated against, the paper presents a dilemma: if there were no constitutively constructed social kinds, the causes of the discrimination of existing social groups would have to be addressed, and understanding causal social construction would be relevant to achieve social justice. On the other hand, not all possible constitutively socially constructed kinds are actual social kinds. If an existing social group is constitutively constructed as a social kind K, the fact that it actually exists as a K has social causes. Again, causal social construction is relevant. The paper argues that (i for any actual social kind X, if X is constitutively socially constructed as K, then it is also causally socially constructed; and (ii causal social construction is at least as relevant as constitutive social construction for concerns of social justice. For illustration, I draw upon two phenomena that are presumed to contribute towards the discrimination of women: (i the poor performance effects of stereotype threat, and (ii the silencing effects of gendered language use.

  1. Inferring Non-Observed Correlations from Causal Scenarios: The Role of Causal Knowledge

    Science.gov (United States)

    Perales, Jose C.; Catena, Andres; Maldonado, Antonio

    2004-01-01

    This work aimed at demonstrating, first, that naive reasoners are able to infer the existence of a relationship between two events that have never been presented together and, second, the sensitivity of such inference to the causal structure of the task. In all experiments, naive participants judged the strength of the causal link between a cue A…

  2. Etiological agents of diarrhea in patients infected by the human immunodeficiency virus-1: a review Agentes etiológicos da diarréia em pacientes infectados pelo vírus da imunodeficiência tipo-1: revisão

    Directory of Open Access Journals (Sweden)

    Andréa Regina Baptista Rossit

    2009-04-01

    Full Text Available Despite the importance of understanding the epidemiology of agents responsible for infectious diarrhea in human immunodeficiency virus (HIV/acquired immunodeficiency syndrome (AIDS population, the number of articles about this subject is relatively few. The current article summarizes published data on bacterial, fungal, viral and parasitic enteropathogens in the HIV/AIDS seropositive subjects in different countries, regions and localities. In general, there is a great difference in the frequencies of etiological agents due to factors which include immune status, geographical location, climate and socioeconomic conditions. It is important to stress that a great prevalence of infection by emergent agents has been reported in the more advanced stages of AIDS. Therefore, to establish specific treatment depends directly on knowledge of these agents and risk factors associated to their distribution. Moreover, the colonization by potential pathogenic agents verified in these individuals is high thus implicating that they act as carriers. Finally, public health measures of control and prevention must take into consideration the regional previously identified enteropathogens, especially in areas where HIV prevalence is high.Muito embora a importância do conhecimento sobre a epidemiologia dos agentes responsáveis pela diarréia infecciosa nos portadores do vírus da imunodeficiência humana (HIV e/ou doentes pela síndrome da imunodeficiência adquirida (SIDA, o número de artigos científicos sobre o tema é relativamente pequeno. Este artigo resume os dados já publicados sobre os enteropatógenos bacterianos, fúngicos, virais e parasitários que acometem os indivíduos soropositivos para o HIV e/ou doentes pela SIDA em diferentes países, regiões e localidades. Em geral, existe uma grande diferença nas freqüências dos agentes etiológicos, devido a fatores que incluem status imunológico, localização geográfica, clima e condições socioecon

  3. Causality in 3D massive gravity theories

    Science.gov (United States)

    Edelstein, José D.; Giribet, Gaston; Gómez, Carolina; Kilicarslan, Ercan; Leoni, Matías; Tekin, Bayram

    2017-05-01

    We study the constraints coming from the local causality requirement in various 2 +1 dimensional dynamical theories of gravity. In topologically massive gravity, with a single parity noninvariant massive degree of freedom, and in new massive gravity, with two massive spin-2 degrees of freedom, causality and unitarity are compatible with each other and both require the Newton's constant to be negative. In their extensions, such as the Born-Infeld gravity and the minimal massive gravity the situation is similar and quite different from their higher dimensional counterparts, such as quadratic (e.g., Einstein-Gauss-Bonnet) or cubic theories, where causality and unitarity are in conflict. We study the problem both in asymptotically flat and asymptotically anti-de Sitter spaces.

  4. Diabetes: the layperson's theories of causality.

    Science.gov (United States)

    Mercado-Martinez, Francisco J; Ramos-Herrera, Igor Martin

    2002-07-01

    The authors examine laypersons' perspectives of illness: the content of causal explanations of diabetes and differences in explanations according to gender. Qualitative research was carried out in Guadalajara, Mexico. A nonprobabilistic sample of 20 diabetic individuals participated in interviews, and the content of the interviews was analyzed. On the origin of their condition, participants offered explanations that match neither the biomedical model nor any other formal causal theory. Participants attributed the onset of diabetes to socioemotional circumstances linked to their life experiences and practices. Men attributed causality to work and social circumstances outside the home; women attributed it to family life and domestic circumstances. The authors discuss how lay theories can be useful for the reorganization of health services.

  5. Causal diagrams, information bias, and thought bias.

    Science.gov (United States)

    Shahar, Eyal; Shahar, Doron J

    2010-01-01

    Information bias might be present in any study, including randomized trials, because the values of variables of interest are unknown, and researchers have to rely on substitute variables, the values of which provide information on the unknown true values. We used causal directed acyclic graphs to extend previous work on information bias. First, we show that measurement is a complex causal process that has two components, ie, imprinting and synthesizing. Second, we explain how the unknown values of a variable may be imputed from other variables, and present examples of valid and invalid substitutions for a variable of interest. Finally, and most importantly, we describe a previously unrecognized bias, which may be viewed as antithetical to information bias. This bias arises whenever a variable does not exist in the physical world, yet researchers obtain "information" on its nonexistent values and estimate nonexistent causal parameters. According to our thesis, the scientific literature contains many articles that are affected by such bias.

  6. Causal inheritence in plane wave quotients

    Energy Technology Data Exchange (ETDEWEB)

    Hubeny, Veronika E.; Rangamani, Mukund; Ross, Simon F.

    2003-11-24

    We investigate the appearance of closed timelike curves in quotients of plane waves along spacelike isometries. First we formulate a necessary and sufficient condition for a quotient of a general spacetime to preserve stable causality. We explicitly show that the plane waves are stably causal; in passing, we observe that some pp-waves are not even distinguishing. We then consider the classification of all quotients of the maximally supersymmetric ten-dimensional plane wave under a spacelike isometry, and show that the quotient will lead to closed timelike curves iff the isometry involves a translation along the u direction. The appearance of these closed timelike curves is thus connected to the special properties of the light cones in plane wave spacetimes. We show that all other quotients preserve stable causality.

  7. Structural intervention distance for evaluating causal graphs.

    Science.gov (United States)

    Peters, Jonas; Bühlmann, Peter

    2015-03-01

    Causal inference relies on the structure of a graph, often a directed acyclic graph (DAG). Different graphs may result in different causal inference statements and different intervention distributions. To quantify such differences, we propose a (pre-)metric between DAGs, the structural intervention distance (SID). The SID is based on a graphical criterion only and quantifies the closeness between two DAGs in terms of their corresponding causal inference statements. It is therefore well suited for evaluating graphs that are used for computing interventions. Instead of DAGs, it is also possible to compare CPDAGs, completed partially DAGs that represent Markov equivalence classes. The SID differs significantly from the widely used structural Hamming distance and therefore constitutes a valuable additional measure. We discuss properties of this distance and provide a (reasonably) efficient implementation with software code available on the first author's home page.

  8. Synthesis, antiviral evaluation and molecular docking studies of N4-aryl substituted/unsubstituted thiosemicarbazones derived from 1-indanones as potent anti-bovine viral diarrhea virus agents.

    Science.gov (United States)

    Soraires Santacruz, María C; Fabiani, Matías; Castro, Eliana F; Cavallaro, Lucía V; Finkielsztein, Liliana M

    2017-08-01

    A series of N4-arylsubstituted thiosemicarbazones derived from 1-indanones and a set of compounds lacking such substitution in the N4 position of the thiosemicarbazone moiety were synthesized and evaluated for their anti-bovine viral diarrhea virus (BVDV) activity. Among these, derivatives 2 and 15 displayed high activity (EC50=2.7±0.4 and 0.7±0.1µM, respectively) as inhibitors of BVDV replication. Novel key structural features related to the anti-BVDV activity were identified by structure-activity relationship (SAR) analysis. In a previous study, the thiosemicarbazone of 5,6-dimethoxy-1-indanone (5,6-TSC) was characterized as a non-nucleoside inhibitor (NNI) of the BVDV RNA-dependent RNA polymerase. In the present work, cross-resistance assays were performed with the most active compounds. Such studies were carried out on 5,6-TSC resistant BVDV (BVDV-TSCr T1) carrying mutations in the viral polymerase. This BVDV mutant was also resistant to compound 15. Molecular docking studies and MM/PBSA calculations were performed to assess the most active derivatives at the 5,6-TSC viral polymerase binding site. The differences in the interaction pattern and the binding affinity of derivative 15 either to the wild type or BVDV-TSCr T1 polymerase were key factors to define the mode of action of this compound. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Successful Treatment of Oral Lichen Planus with Direct-Acting Antiviral Agents after Liver Transplantation for Hepatitis C Virus-Associated Hepatocellular Carcinoma

    Directory of Open Access Journals (Sweden)

    Yumiko Nagao

    2017-11-01

    Full Text Available Hepatitis C virus (HCV infection is frequently associated with various extrahepatic manifestations, such as autoimmune features and immune complex deposit diseases. Oral lichen planus (OLP is one such extrahepatic manifestation of HCV infection. Recently, direct-acting antivirals (DAA have proved to be highly effective and safe for the eradication of HCV. Herein, we report a case of OLP accompanied by HCV-related hepatocellular carcinoma (HCC that disappeared after liver transplantation and achievement of sustained virological response following interferon (IFN-free treatment with ledipasvir (LDV and sofosbuvir (SOF. The 50-year-old patient developed erosive OLP during IFN therapy, with hyperthyroidism at 53 years of age and HCC at 55 years. He received immunosuppressive drugs and IFN-free DAA treatment after liver transplantation at 60 years of age, which led to disappearance of the symptoms of OLP. The patient was treated safely and effectively with LDV/SOF, although it is not known whether the disappearance of OLP resulted from the eradication of HCV or the immunosuppressive therapy.

  10. Causal interpretation of stochastic differential equations

    DEFF Research Database (Denmark)

    Sokol, Alexander; Hansen, Niels Richard

    2014-01-01

    We give a causal interpretation of stochastic differential equations (SDEs) by defining the postintervention SDE resulting from an intervention in an SDE. We show that under Lipschitz conditions, the solution to the postintervention SDE is equal to a uniform limit in probability of postintervention...... structural equation models based on the Euler scheme of the original SDE, thus relating our definition to mainstream causal concepts. We prove that when the driving noise in the SDE is a Lévy process, the postintervention distribution is identifiable from the generator of the SDE....

  11. Causality between Literacy and Labor Productivity.

    Science.gov (United States)

    Khan, Shahrukh R.; And Others

    1991-01-01

    Utilizes the Granger causality test to estimate case and effect relationships between literacy and labor productivity in Pakistani manufacturing and agricultural sectors. Despite data set limitations, literacy appears to "cause" labor productivity to increase in the manufacturing sector. (27 references) (MLH)

  12. Causal Meta-Analysis : Methodology and Applications

    NARCIS (Netherlands)

    Bax, L.J.|info:eu-repo/dai/nl/304818577

    2009-01-01

    Meta-analysis is a statistical method to summarize research data from multiple studies in a quantitative manner. This dissertation addresses a number of methodological topics in causal meta-analysis and reports the development and validation of meta-analysis software. In the first (methodological)

  13. The Causal Priority of Form in Aristotle

    Directory of Open Access Journals (Sweden)

    Kathrin Koslicki

    2014-12-01

    Full Text Available In various texts (e.g., Met. Z.17, Aristotle assigns priority to form, in its role as a principle and cause, over matter and the matter-form compound. Given the central role played by this claim in Aristotle's search for primary substance in the Metaphysics, it is important to understand what motivates him in locating the primary causal responsibility for a thing's being what it is with the form, rather than the matter. According to Met. Theta.8, actuality [energeia/entelecheia] in general is prior to potentiality [dunamis] in three ways, viz., in definition, time and substance. I propose an explicitly causal reading of this general priority claim, as it pertains to the matter-form relationship. The priority of form over matter in definition, time and substance, in my view, is best explained by appeal to the role of form as the formal, efficient and final cause of the matter-form compound, respectively, while the posteriority of matter to form according to all three notions of priority is most plausibly accounted for by the fact that the causal contribution of matter is limited to its role as material cause. When approached from this angle, the work of Met. Theta.8 can be seen to lend direct support to the more specific and explicitly causal priority claim we encounter in Met. Z.17, viz., that form is prior to matter in its role as the principle and primary cause of a matter-form compound's being what it is.

  14. Instrumental variable methods for causal inference.

    Science.gov (United States)

    Baiocchi, Michael; Cheng, Jing; Small, Dylan S

    2014-06-15

    A goal of many health studies is to determine the causal effect of a treatment or intervention on health outcomes. Often, it is not ethically or practically possible to conduct a perfectly randomized experiment, and instead, an observational study must be used. A major challenge to the validity of observational studies is the possibility of unmeasured confounding (i.e., unmeasured ways in which the treatment and control groups differ before treatment administration, which also affect the outcome). Instrumental variables analysis is a method for controlling for unmeasured confounding. This type of analysis requires the measurement of a valid instrumental variable, which is a variable that (i) is independent of the unmeasured confounding; (ii) affects the treatment; and (iii) affects the outcome only indirectly through its effect on the treatment. This tutorial discusses the types of causal effects that can be estimated by instrumental variables analysis; the assumptions needed for instrumental variables analysis to provide valid estimates of causal effects and sensitivity analysis for those assumptions; methods of estimation of causal effects using instrumental variables; and sources of instrumental variables in health studies. Copyright © 2014 John Wiley & Sons, Ltd.

  15. Special Relativity, Causality and Quantum Mechanics - 2

    Indian Academy of Sciences (India)

    We discuss the aspects of non-locality and non- separability of states of composite quantum sys- tems. The probabilistic nature of quantum mech- anical predictions, and the impossibility of clon- ing, are shown to safeguard causality in the quan- tum world. An example of a game which can be won exploiting quantum ...

  16. Assessment of resampling methods for causality testing

    NARCIS (Netherlands)

    Papana, A.; Kyrtsou, C.; Kugiumtzis, D.; Diks, C.

    2014-01-01

    Different resampling methods for the null hypothesis of non-causality are assessed. As test statistic the partial transfer entropy (PTE), an information and model-free measure, is used. Two resampling techniques,1) the time shifted surrogates and 2) the stationary bootstrap, are combined with the

  17. Inferring causality from noisy time series data

    DEFF Research Database (Denmark)

    Mønster, Dan; Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    and even causality direction in synchronized time-series and in the presence of intermediate coupling. We find that the presence of noise deterministically reduces the level of cross-mapping fidelity, while the convergence rate exhibits higher levels of robustness. Finally, we propose that controlled noise...

  18. Causality relationship between energy demand and economic ...

    African Journals Online (AJOL)

    The Johansen co integration technique reveals that one co integrating relationship exists between real GDP and Electricity demand in Nigeria. The result of the study reveals that there is unidirectional causality between energy consumption and economic growth i.e. energy consumption Granger causes economic growth in ...

  19. Causal and Teleological Explanations in Biology

    Science.gov (United States)

    Yip, Cheng-Wai

    2009-01-01

    A causal explanation in biology focuses on the mechanism by which a biological process is brought about, whereas a teleological explanation considers the end result, in the context of the survival of the organism, as a reason for certain biological processes or structures. There is a tendency among students to offer a teleological explanation…

  20. Causality and Teleology in High School Biology.

    Science.gov (United States)

    Tamir, Pinchas

    1985-01-01

    Ability to distinguish between causal (cause-effect) and teleological (means-ends) explanations was measured in 1905 twelfth-grade biology students and found to be dependent on student knowledge. Although the inability to make these distinctions contributes to misconceptions in biology, appropriate instruction can easily remedy the problem. Sample…

  1. A stochastic causality-based process algebra

    NARCIS (Netherlands)

    Brinksma, Hendrik; Katoen, Joost P.; Langerak, Romanus; Latella, Diego

    1995-01-01

    This paper discusses stochastic extensions of a simple process algebra in a causality-based setting. Atomic actions are supposed to happen after a delay that is determined by a stochastic variable with a certain distribution. A simple stochastic type of event structures is discussed, restricting the

  2. THE CAUSAL TEXTURE OF TRADE UNION ENVIRONMENTS

    African Journals Online (AJOL)

    Admin

    This paper is an attempt to fill an important gap in the existing literature on trade unions by providing a more adequate theoretical formulation of trade union environments. The discussion suggests that unlike the environment of business and related organisations whose causal texture is understood in terms of uncertainty, ...

  3. The semiclassical limit of causal dynamical triangulations

    NARCIS (Netherlands)

    Ambjørn, J.; Görlich, A.T.; Jurkiewicz, J.; Loll, R.|info:eu-repo/dai/nl/304830720; Gizbert-Studnicki, J.; Trześniewski, T.

    2011-01-01

    Previous work has shown that the macroscopic structure of the theory of quantum gravity defined by causal dynamical triangulations (CDT) is compatible with that of a de Sitter universe. After emphasizing the strictly nonperturbative nature of this semiclassical limit we present a detailed study of

  4. Quantum computation with indefinite causal structures

    Science.gov (United States)

    Araújo, Mateus; Guérin, Philippe Allard; Baumeler, ńmin

    2017-11-01

    One way to study the physical plausibility of closed timelike curves (CTCs) is to examine their computational power. This has been done for Deutschian CTCs (D-CTCs) and postselection CTCs (P-CTCs), with the result that they allow for the efficient solution of problems in PSPACE and PP, respectively. Since these are extremely powerful complexity classes, which are not expected to be solvable in reality, this can be taken as evidence that these models for CTCs are pathological. This problem is closely related to the nonlinearity of this models, which also allows, for example, cloning quantum states, in the case of D-CTCs, or distinguishing nonorthogonal quantum states, in the case of P-CTCs. In contrast, the process matrix formalism allows one to model indefinite causal structures in a linear way, getting rid of these effects and raising the possibility that its computational power is rather tame. In this paper, we show that process matrices correspond to a linear particular case of P-CTCs, and therefore that its computational power is upperbounded by that of PP. We show, furthermore, a family of processes that can violate causal inequalities but nevertheless can be simulated by a causally ordered quantum circuit with only a constant overhead, showing that indefinite causality is not necessarily hard to simulate.

  5. Black Hole Complementarity and Violation of Causality

    OpenAIRE

    Rozenblit, Moshe

    2017-01-01

    Analysis of a massive shell collapsing on a solid sphere shows that black hole complementarity (BHC) violates causality in its effort to save information conservation. In particular, this note describes a hypothetical contraption based on BHC that would allow the transfer of information from the future to the present.

  6. Are bruxism and the bite causally related?

    NARCIS (Netherlands)

    Lobbezoo, F.; Ahlberg, J.; Manfredini, D.; Winocur, E.

    2012-01-01

    In the dental profession, the belief that bruxism and dental (mal-)occlusion (‘the bite’) are causally related is widespread. The aim of this review was to critically assess the available literature on this topic. A PubMed search of the English-language literature, using the query ‘Bruxism [Majr

  7. Nonlinear Granger Causality: Guidelines for Multivariate Analysis

    NARCIS (Netherlands)

    Diks, C.; Wolski, M.

    2016-01-01

    We propose an extension of the bivariate nonparametric Diks–Panchenko Granger non-causality test to multivariate settings. We first show that the asymptotic theory for the bivariate test fails to apply to the multivariate case, because the kernel density estimator bias and variance cannot both tend

  8. THE CAUSAL TEXTURE OF TRADE UNION ENVIRONMENTS

    African Journals Online (AJOL)

    Admin

    providing a more adequate theoretical formulation of trade union environments. The discussion suggests that unlike the environment of business and related organisations whose causal texture is understood in terms of uncertainty, complexity, instability and turbulence that of trade unions needs to be understood in terms of ...

  9. Linear Response Laws and Causality in Electrodynamics

    Science.gov (United States)

    Yuffa, Alex J.; Scales, John A.

    2012-01-01

    Linear response laws and causality (the effect cannot precede the cause) are of fundamental importance in physics. In the context of classical electrodynamics, students often have a difficult time grasping these concepts because the physics is obscured by the intermingling of the time and frequency domains. In this paper, we analyse the linear…

  10. Causal Relationship between Teachers' Job Performance and ...

    African Journals Online (AJOL)

    The study investigated teachers' job performance and students' academic achievement in secondary schools for the existence of bi-causal relationship in Nigeria. The ex-post facto ... With a Cronbach alpha reliability of (α) 0.79, data was analysed using the step-wise multiple linear regression analysis. Findings showed that ...

  11. Escaping Myopia: Teaching Students about Historical Causality

    Science.gov (United States)

    Waring, Scott M.

    2010-01-01

    There are so many aspects to teaching history that are vital to creating well-rounded historical thinkers, but one of the most fundamental and most overlooked elements is the idea of causality. Far too many students do not understand the idea of causation, that there are multiple reasons for why historical events occurred and transpired in the way…

  12. Distinguishing Valid from Invalid Causal Indicator Models

    Science.gov (United States)

    Cadogan, John W.; Lee, Nick

    2016-01-01

    In this commentary from Issue 14, n3, authors John Cadogan and Nick Lee applaud the paper by Aguirre-Urreta, Rönkkö, and Marakas "Measurement: Interdisciplinary Research and Perspectives", 14(3), 75-97 (2016), since their explanations and simulations work toward demystifying causal indicator models, which are often used by scholars…

  13. Probable autoimmune causal relationship between periodontitis and ...

    African Journals Online (AJOL)

    Periodontitis is a multifactorial disease with microbial dental plaque as the initiator of periodontal disease. However, the manifestation and progression of the disease is influenced by a wide variety of determinants and factors. The strongest type of causal relationship is the association of systemic and periodontal disease.

  14. Encoding dependence in Bayesian causal networks

    Science.gov (United States)

    Bayesian networks (BNs) represent complex, uncertain spatio-temporal dynamics by propagation of conditional probabilities between identifiable states with a testable causal interaction model. Typically, they assume random variables are discrete in time and space with a static network structure that ...

  15. The Causal Relationship between Financial Development and ...

    African Journals Online (AJOL)

    The study employs cointegration, vector error correction model and Granger causality test to ascertain causation between financial development and economic performance in Tanzania. Economic performance is measured by the real GDP, whereas proxies for financial development are: the ratio of money supply to nominal ...

  16. Quantum Common Causes and Quantum Causal Models

    Science.gov (United States)

    Allen, John-Mark A.; Barrett, Jonathan; Horsman, Dominic C.; Lee, Ciarán M.; Spekkens, Robert W.

    2017-07-01

    Reichenbach's principle asserts that if two observed variables are found to be correlated, then there should be a causal explanation of these correlations. Furthermore, if the explanation is in terms of a common cause, then the conditional probability distribution over the variables given the complete common cause should factorize. The principle is generalized by the formalism of causal models, in which the causal relationships among variables constrain the form of their joint probability distribution. In the quantum case, however, the observed correlations in Bell experiments cannot be explained in the manner Reichenbach's principle would seem to demand. Motivated by this, we introduce a quantum counterpart to the principle. We demonstrate that under the assumption that quantum dynamics is fundamentally unitary, if a quantum channel with input A and outputs B and C is compatible with A being a complete common cause of B and C , then it must factorize in a particular way. Finally, we show how to generalize our quantum version of Reichenbach's principle to a formalism for quantum causal models and provide examples of how the formalism works.

  17. Reassessing the causal structure of enduring involvement

    Science.gov (United States)

    Jinhee Jun; Gerard T. Kyle; James D. Absher; William E. Hammitt

    2009-01-01

    Guided by tenets of identity theory, we hypothesized a causal structure of enduring involvement suggesting that self-relevant components precede the other dimensions. We used Kyle et al.'s (2004a) Modified Involvement Scale, in which leisure involvement is conceptualized as a multidimensional construct consisting of identity affirmation, identity expression,...

  18. El virus del papiloma humano (HPV, agente viral importante precusor de la mayoría de las displasias o cáncer cervical

    Directory of Open Access Journals (Sweden)

    Claudia Patricia Consuegra Mayor

    2004-01-01

    Full Text Available Una de las patologías más frecuentes con la que el hombre ha tenido que luchar en las últimas décadas es el cáncer. Los países industrializados y aun aquellos en vía de desarrollo se han dado a la tarea de combatir el cáncer, han hecho grandes esfuerzos e invertido cantidades de dinero con el propósito de conocer el origen y seguimiento de esta enfermedad y buscar alternativas que ayuden a erradicarla o a limitarla. Son impresionantes los datos recientes respecto al origen del cáncer a nivel molecular y se conocen con más precisión los procesos de progresión, invasión y metástasis tumoral (1. Todos estos experimentos han podido dilucidar algunos factores potenciadores o estimuladores para la aparición de esta enfermedad. El cáncer de cuello uterino es el segundo cáncer más común en la mujer después del cáncer de mama, y existe un desproporcionado aumento del cáncer cervical en mujeres jóvenes (2. Como el cáncer de cuello uterino se desarrolla en mujeres más jóvenes que el de mama, es una de las neoplasias malignas más devastadoras y es el principal cáncer genital femenino en los países en desarrollo (3,4. En Colombia es la segunda causa de mortalidad femenina (5. Desde hace más de 100 años se ha considerado que el cáncer cervical tiene una causa infecciosa (1. Posteriormente se demostró que los virus del papiloma humano (HPV, por su sigla en inglés human papillomavirus contribuyen directamente en la carcinogénesis. Es de anotar que el HPV es causa necesaria para el desarrollo del cáncer de cérvix, pero no es suficiente, ya que otros factores están involucrados en la progresión de infección a cáncer (6

  19. Developing a Novel Parameter Estimation Method for Agent-Based Model in Immune System Simulation under the Framework of History Matching: A Case Study on Influenza A Virus Infection

    Directory of Open Access Journals (Sweden)

    Tingting Li

    2017-12-01

    Full Text Available Since they can provide a natural and flexible description of nonlinear dynamic behavior of complex system, Agent-based models (ABM have been commonly used for immune system simulation. However, it is crucial for ABM to obtain an appropriate estimation for the key parameters of the model by incorporating experimental data. In this paper, a systematic procedure for immune system simulation by integrating the ABM and regression method under the framework of history matching is developed. A novel parameter estimation method by incorporating the experiment data for the simulator ABM during the procedure is proposed. First, we employ ABM as simulator to simulate the immune system. Then, the dimension-reduced type generalized additive model (GAM is employed to train a statistical regression model by using the input and output data of ABM and play a role as an emulator during history matching. Next, we reduce the input space of parameters by introducing an implausible measure to discard the implausible input values. At last, the estimation of model parameters is obtained using the particle swarm optimization algorithm (PSO by fitting the experiment data among the non-implausible input values. The real Influeza A Virus (IAV data set is employed to demonstrate the performance of our proposed method, and the results show that the proposed method not only has good fitting and predicting accuracy, but it also owns favorable computational efficiency.

  20. Developing a Novel Parameter Estimation Method for Agent-Based Model in Immune System Simulation under the Framework of History Matching: A Case Study on Influenza A Virus Infection.

    Science.gov (United States)

    Li, Tingting; Cheng, Zhengguo; Zhang, Le

    2017-12-01

    Since they can provide a natural and flexible description of nonlinear dynamic behavior of complex system, Agent-based models (ABM) have been commonly used for immune system simulation. However, it is crucial for ABM to obtain an appropriate estimation for the key parameters of the model by incorporating experimental data. In this paper, a systematic procedure for immune system simulation by integrating the ABM and regression method under the framework of history matching is developed. A novel parameter estimation method by incorporating the experiment data for the simulator ABM during the procedure is proposed. First, we employ ABM as simulator to simulate the immune system. Then, the dimension-reduced type generalized additive model (GAM) is employed to train a statistical regression model by using the input and output data of ABM and play a role as an emulator during history matching. Next, we reduce the input space of parameters by introducing an implausible measure to discard the implausible input values. At last, the estimation of model parameters is obtained using the particle swarm optimization algorithm (PSO) by fitting the experiment data among the non-implausible input values. The real Influeza A Virus (IAV) data set is employed to demonstrate the performance of our proposed method, and the results show that the proposed method not only has good fitting and predicting accuracy, but it also owns favorable computational efficiency.

  1. Zika Virus Antagonizes Type I Interferon Responses during Infection of Human Dendritic Cells

    OpenAIRE

    Bowen, James R.; Quicke, Kendra M; Maddur, Mohan S.; Justin T O'Neal; McDonald, Circe E.; Fedorova, Nadia B.; Vinita Puri; Reed S. Shabman; Bali Pulendran; Suthar, Mehul S.

    2017-01-01

    Zika virus (ZIKV) is an emerging mosquito-borne flavivirus that is causally linked to severe neonatal birth defects, including microcephaly, and is associated with Guillain-Barre syndrome in adults. Dendritic cells (DCs) are an important cell type during infection by multiple mosquito-borne flaviviruses, including dengue virus, West Nile virus, Japanese encephalitis virus, and yellow fever virus. Despite this, the interplay between ZIKV and DCs remains poorly defined. Here, we found human DCs...

  2. On the need to assess cancer risk in populations environmentally and occupationally exposed to virus and chemical agents in developing countries Sobre a necessidade de avaliação dos riscos de câncer em populações dos países em desenvolvimento expostas ambiental e ocupacionalmente a vírus e agentes químicos

    Directory of Open Access Journals (Sweden)

    Guilherme Franco Netto

    1998-01-01

    Full Text Available Evidence exists that exposure to poultry oncogenic viruses may produce elevated cancer mortality in human populations, particularly excesses of cancer of lung and excesses of cancer of lymphopoietic tissues. To date, this potential risk is unknown in populations from the developing countries. This paper suggests the need to assess cancer risk in populations of developing countries with reported environmental exposure to chicken meat products and eggs; the need to assess risk of cancer in populations inoculated with vaccines from infected chicken embryos; and the need to assess risk of cancer in occupational populations highly exposed to poultry oncogenic viruses, and with potential concurrent exposure to chemical agents known or suspected to be carcinogens.Existe evidência de que exposição a vírus oncogênicos de aves possa produzir elevada mortalidade de câncer em populações humanas, havendo particularmente excesso de câncer de pulmão e dos sistemas linfáticos e hemopoiéticos. Até o momento, esse risco potencial é desconhecido em populações dos países em desenvolvimento. Este manuscrito sugere a necessidade de avaliar o risco de câncer em populações dos países em desenvolvimento com sabida exposição a produtos avícolas e ovos; a necessidade de avaliar o risco de câncer em populações que foram inoculadas com vacinas desenvolvidas em embriões de aves contaminadas e a necessidade de avaliar o risco de câncer em populações de trabalhadores com grande exposição a vírus oncogênico de aves, e com potencial exposição simultânea a agentes químicos que são reconhecidos ou suspeitos carcinógenos.

  3. Localization and subcellular association of Grapevine Pinot Gris Virus in grapevine leaf tissues.

    Science.gov (United States)

    Tarquini, Giulia; Ermacora, Paolo; Bianchi, Gian Luca; De Amicis, Francesca; Pagliari, Laura; Martini, Marta; Loschi, Alberto; Saldarelli, Pasquale; Loi, Nazia; Musetti, Rita

    2017-12-22

    Despite the increasing impact of Grapevine Pinot gris disease (GPG-disease) worldwide, etiology about this disorder is still uncertain. The presence of the putative causal agent, the Grapevine Pinot Gris Virus (GPGV), has been reported in symptomatic grapevines (presenting stunting, chlorotic mottling, and leaf deformation) as well as in symptom-free plants. Moreover, information on virus localization in grapevine tissues and virus-plant interactions at the cytological level is missing at all. Ultrastructural and cytochemical investigations were undertaken to detect virus particles and the associated cytopathic effects in field-grown grapevine showing different symptom severity. Asymptomatic greenhouse-grown grapevines, which tested negative for GPGV by real time RT-PCR, were sampled as controls. Multiplex real-time RT-PCR and ELISA tests excluded the presence of viruses included in the Italian certification program both in field-grown and greenhouse-grown grapevines. Conversely, evidence was found for ubiquitous presence of Grapevine Rupestris Stem Pitting-associated Virus (GRSPaV), Hop Stunt Viroid (HSVd), and Grapevine Yellow Speckle Viroid 1 (GYSVd-1) in both plant groups. Moreover, in every field-grown grapevine, GPGV was detected by real-time RT-PCR. Ultrastructural observations and immunogold labelling assays showed filamentous flexuous viruses in the bundle sheath cells, often located inside membrane-bound organelles. No cytological differences were observed among field-grown grapevine samples showing different symptom severity. GPGV localization and associated ultrastructural modifications are reported and discussed, in the perspective of assisting management and control of the disease.

  4. Development of Lead Compounds as Fusion Inhibitors for Dengue Virus

    Science.gov (United States)

    2009-08-01

    Identification of antiviral agents is critical to the development of therapeutic treatments directed against dengue virus (DENV), for which there is no...infection and exposure of US military personnel to the disease might be offered by antiviral agents as a treatment strategy. The dengue virus...0285 TITLE: DEVELOPMENT OF LEAD COMPOUNDS AS FUSION INHIBITORS FOR DENGUE VIRUS PRINCIPAL INVESTIGATOR: TOMAS PEREZ-ACLE

  5. Dialogue and causality: global description from local observations and vague communications.

    Science.gov (United States)

    Sawa, Koji; Gunji, Yukio-Pegio

    2007-01-01

    We propose a dialogue-based society model which explains how the transitive law of the causality is originated. Causality is, in general, formalized by using axiomatic approaches. Instead of using axiomatic methods, we, however, compose a model consisting of agents who have knowledge about causal relations among objects. The model society can reveal the transitive law through interactional dialogues among themselves. The agents are reciprocally influenced, if they have either completely same opinions, or a particular pattern of opinions, that are regarded as the extension of such exact accordance. In addition, we add some vagueness to the dialogue, which is closer to a real communication than the former model. A set of knowledge of each agent is expressed as a directed graph, hence the every model can be construed as mere transformations of directed graphs through the interactions among directed graphs themselves. Following this perspective, the models are the systems that connect local logic with global one, while the union of the directed graphs is regarded as the global.

  6. Coat protein sequence shows that Cucumber mosaic virus isolate ...

    Indian Academy of Sciences (India)

    A viral disease was identified on geraniums (Pelargonium spp.) grown in a greenhouse at the Institute of Himalayan Bioresource Technology (IHBT), Palampur, exhibiting mild mottling and stunting. The causal virus (Cucumber mosaic virus, CMV) was identified and characterized on the basis of host range, aphid ...

  7. Causal knowledge and the development of inductive reasoning.

    Science.gov (United States)

    Bright, Aimée K; Feeney, Aidan

    2014-06-01

    We explored the development of sensitivity to causal relations in children's inductive reasoning. Children (5-, 8-, and 12-year-olds) and adults were given trials in which they decided whether a property known to be possessed by members of one category was also possessed by members of (a) a taxonomically related category or (b) a causally related category. The direction of the causal link was either predictive (prey→predator) or diagnostic (predator→prey), and the property that participants reasoned about established either a taxonomic or causal context. There was a causal asymmetry effect across all age groups, with more causal choices when the causal link was predictive than when it was diagnostic. Furthermore, context-sensitive causal reasoning showed a curvilinear development, with causal choices being most frequent for 8-year-olds regardless of context. Causal inductions decreased thereafter because 12-year-olds and adults made more taxonomic choices when reasoning in the taxonomic context. These findings suggest that simple causal relations may often be the default knowledge structure in young children's inductive reasoning, that sensitivity to causal direction is present early on, and that children over-generalize their causal knowledge when reasoning. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Causal Factors for The Adoption Innovation Teacher’s Tv for Teachersand Educational Personnel

    Directory of Open Access Journals (Sweden)

    Thanadol Phuseerit

    2016-12-01

    aire for the experts to examine the causal factors for the adoption innovation teacher’s TV for teachers and education personnel model by focus groups, 4 questionnaire to confirm the causal factors to an innovation teacher’s TV model for teachers and educational personnel Committee of the teacher’s TV, 5 the causal factor for the adoption innovation teacher’s TV for teachers and education personnel model, 6 evaluation form of the causal factor for the adoption of the innovation teacher’s TV for teachers and education personnel model from the specialists. The research results were: 1 The causal factors for the adoption innovation teacher’s TV for Teachers and educational personnel Model. Elements and factors are as follows: 1.1 Elements of the causes and factors of innovation teacher’s TV. Teachers and educational personnel The Review of literature and semi-structured questionnaire, interviewing Collecting quality data from in-depth interviews with a total 9 causal as fallow: (1 Characteristics of innovation, included: relative Advantage, Compatibility, Complexity, Trial ability, Observable (2 Communication Channels, included: interpersonal communication, the media as press, radio, television, communication specialized media (3 Innovation-Decision Process, included: Knowledge, Persuasion, Decision, Implementation, Confirmation (4 Economy and Social System, include: compensation and benefits. Social interaction, (5 Attitude, included: understanding the emotions, behavior (6 Motivation, included: Intrinsic motivation. External motivation (7 Support of Administrator, include: support for innovation, the budget support and materials, Academic support (8 Change agent, included: knowledge and ability, Skill-oriented capabilities Ability attitude (9 Opinion Leaders, included: access to others easily, Creative and 1element of the Adoption of the Innovation: TTV, included: the perceived ease of use, and Perceived benefits. The model’s validity of the consistency

  9. Aspectos moleculares del virus de la parvovirosis canina y sus implicaciones en la enfermedad

    Directory of Open Access Journals (Sweden)

    César A. Díaz R.

    2008-06-01

    Full Text Available El parvovirus canino tipo 2 (CPV-2 es el agente causal de una enfermedad infecto-contagiosa que produce una gastroenteritis aguda hemorrágica que afecta a caninos jóvenes. El CPV-2 se adaptó a la especie canina por mutación del virus de la Panleucopenia felina (FPV luego de su paso por animales silvestres como el hurón y los zorros. La alta variabilidad de la proteína viral 2 (VP2 es la causa principal del amplio rango de hospedadores y de las reacciones cruzadas entre las variantes. En la actualidad, la secuenciación de esta proteína ha permitido identificar tres variantes del virus conocidas como 2a, 2b y 2c que conviven en el mundo con diferencias en tropismo celular, infecciocidad y patogenicidad. El virus ssADN ha presentado una gran variación génica en cortos períodos de tiempo lo que indica un alto grado de selección por evolución sólo comparable con virus RN, esta alta variabilidad no se ha aclarado totalmente. El empleo de las técnicas moleculares permitirá diferenciar entre cepas vacunales y de campo, tanto como contar con técnicas diagnósticas confiables y específicas.

  10. Viruses associated with pneumonia in adults.

    Science.gov (United States)

    Cesario, Thomas C

    2012-07-01

    Viral pneumonia, which is typically associated with disease in childhood, is increasingly recognized as causing problems in adults. Certain viruses, such as influenza virus, can attack fully immunocompetent adults, but many viruses take advantage of more-vulnerable patients. The latter include patients receiving immunosuppressive therapy and elderly subjects, particularly those residing in long-term care facilities. The range of viruses producing pneumonia in adults includes common agents, such as varicella-zoster virus and influenza virus, as well as respiratory syncytial virus, human metapneumovirus, adenoviruses, picornaviruses, and coronaviruses. The roles played by other agents, such as rhinoviruses and human bocaviruses, in pneumonia are still under study. While therapy for most of theses agents, at least in adults, has not yet been fully clarified, it is reasonable to assume antivirals may work in certain situations if they are introduced early enough in the course of infection.

  11. Fate of Clavibacter michiganensis ssp. sepedonicus, the causal organism of bacterial ring rot in potato, in weeds and field crops.

    NARCIS (Netherlands)

    Wolf, van der J.M.; Beckhoven, van J.R.C.M.; Hukkanen, A.; Karjalainen, R.; Muller, P.

    2005-01-01

    Crops and weeds were tested for their ability to host Clavibacter michiganensis ssp. sepedonicus (Cms), the causal agent of bacterial ring rot in potato. Ten crops grown in rotation with potato in Europe, namely maize, wheat, barley, oat, bush bean, broad bean, rape, pea and onion and five cultivars

  12. Producción de proteínas recombinantes de valor inmunogénico del virus de la leucosis bovina y su aplicación al diagnóstico de la enfermedad

    OpenAIRE

    Larsen, Alejandra

    2014-01-01

    El virus de la leucosis bovina (VLB) es el agente causal de la Leucosis Enzoótica Bovina (LEB), enfermedad de distribución mundial, presente en nuestro país. En nuestro país los niveles de prevalencia oscilan entre 33% a 84% dependiendo del tipo de explotación bovina, estos altos valores de prevalencia se traducen en grandes pérdidas económicas incluyendo la perdida de mercados internacionales. El programa nacional de control y erradicación reglamentado por el Servicio Nacional de Sanidad Ani...

  13. Localizing epileptic seizure onsets with Granger causality

    Science.gov (United States)

    Adhikari, Bhim M.; Epstein, Charles M.; Dhamala, Mukesh

    2013-09-01

    Accurate localization of the epileptic seizure onset zones (SOZs) is crucial for successful surgery, which usually depends on the information obtained from intracranial electroencephalography (IEEG) recordings. The visual criteria and univariate methods of analyzing IEEG recordings have not always produced clarity on the SOZs for resection and ultimate seizure freedom for patients. Here, to contribute to improving the localization of the SOZs and to understanding the mechanism of seizure propagation over the brain, we applied spectral interdependency methods to IEEG time series recorded from patients during seizures. We found that the high-frequency (>80 Hz) Granger causality (GC) occurs before the onset of any visible ictal activity and causal relationships involve the recording electrodes where clinically identifiable seizures later develop. These results suggest that high-frequency oscillatory network activities precede and underlie epileptic seizures, and that GC spectral measures derived from IEEG can assist in precise delineation of seizure onset times and SOZs.

  14. Normalizing the causality between time series

    CERN Document Server

    Liang, X San

    2015-01-01

    Recently, a rigorous yet concise formula has been derived to evaluate the information flow, and hence the causality in a quantitative sense, between time series. To assess the importance of a resulting causality, it needs to be normalized. The normalization is achieved through distinguishing three types of fundamental mechanisms that govern the marginal entropy change of the flow recipient. A normalized or relative flow measures its importance relative to other mechanisms. In analyzing realistic series, both absolute and relative information flows need to be taken into account, since the normalizers for a pair of reverse flows belong to two different entropy balances; it is quite normal that two identical flows may differ a lot in relative importance in their respective balances. We have reproduced these results with several autoregressive models. We have also shown applications to a climate change problem and a financial analysis problem. For the former, reconfirmed is the role of the Indian Ocean Dipole as ...

  15. The Hankel transform of causal distributions

    Directory of Open Access Journals (Sweden)

    Manuel A. Aguirre T.

    2012-03-01

    Full Text Available In this note we evaluate the unidimensional distributional Hankel transform of \\dfrac{x^{\\alpha-1}_{+}}{\\Gamma^{\\alpha}},\\dfrac{x^{\\alpha-1}_{-}}{\\Gamma^{\\alpha}},dfrac{|x|^{\\alpha-1}}{\\Gamma^{\\frac{\\alpha}{2}}},dfrac{|x|^{\\alpha-1}sgn(x}{\\Gamma^{\\frac{\\alpha +1}{2}}} and (x± i0^{\\alpha-1} and then we extend the formulae to certain kinds of n-dimensional distributions calles "causal" and "anti-causal" distributions. We evaluate the distributional Handel transform of \\dfrac{(m^2+P^{\\alpha -1}_{-}}{\\Gamma^{(\\alpha} }, \\dfrac{|m^2+P|^{\\alpha -1}_{-}}{\\Gamma^{(\\frac{\\alpha}{2}}}, \\dfrac{|m^2+P|^{\\alpha -1}sgn(m^2+P}{\\Gamma (\\frac{\\alpha +1}{2 }} and (m^2+P±i0^{\\alpha-1}

  16. Finite quantum electrodynamics the causal approach

    CERN Document Server

    Scharf, Günter

    2014-01-01

    In this classic text for advanced undergraduates and graduate students of physics, author Günter Scharf carefully analyzes the role of causality in quantum electrodynamics. His approach offers full proofs and detailed calculations of scattering processes in a mathematically rigorous manner. This third edition contains Scharf's revisions and corrections plus a brief new Epilogue on gauge invariance of quantum electrodynamics to all orders. The book begins with Dirac's theory, followed by the quantum theory of free fields and causal perturbation theory, a powerful method that avoids ultraviolet divergences and solves the infrared problem by means of the adiabatic limit. Successive chapters explore properties of the S-matrix — such as renormalizability, gauge invariance, and unitarity — the renormalization group, and interactive fields. Additional topics include electromagnetic couplings and the extension of the methods to non-abelian gauge theories. Each chapter is supplemented with problems, and four appe...

  17. On the Causal Mechanisms of Stuttering

    OpenAIRE

    Alm, Per A

    2005-01-01

    Stuttering is one of the most common speech disorders. However, the etiology is poorly understood, and is likely to be heterogeneous. The aim of this thesis was to clarify causal mechanisms, focusing the brain. The project included theoretical development based on published data, and a broad approach of explorative studies and testing of hypotheses. The theoretical work focused the basal ganglia, leading to a model based on the dual premotor systems hypothesis (G. Goldberg, 1985, 1991)...

  18. Equity Theory Ratios as Causal Schemas

    OpenAIRE

    Alexios Arvanitis; Alexandra Hantzi

    2016-01-01

    Equity theory approaches justice evaluations based on ratios of exchange inputs to exchange outcomes. Situations are evaluated as just if ratios are equal and unjust if unequal. We suggest that equity ratios serve a more fundamental cognitive function than the evaluation of justice. More particularly, we propose that they serve as causal schemas for exchange outcomes, that is, they assist in determining whether certain outcomes are caused by inputs of other people in the context of an exchang...

  19. Causal inference of asynchronous audiovisual speech

    Directory of Open Access Journals (Sweden)

    John F Magnotti

    2013-11-01

    Full Text Available During speech perception, humans integrate auditory information from the voice with visual information from the face. This multisensory integration increases perceptual precision, but only if the two cues come from the same talker; this requirement has been largely ignored by current models of speech perception. We describe a generative model of multisensory speech perception that includes this critical step of determining the likelihood that the voice and face information have a common cause. A key feature of the model is that it is based on a principled analysis of how an observer should solve this causal inference problem using the asynchrony between two cues and the reliability of the cues. This allows the model to make predictions abut the behavior of subjects performing a synchrony judgment task, predictive power that does not exist in other approaches, such as post hoc fitting of Gaussian curves to behavioral data. We tested the model predictions against the performance of 37 subjects performing a synchrony judgment task viewing audiovisual speech under a variety of manipulations, including varying asynchronies, intelligibility, and visual cue reliability. The causal inference model outperformed the Gaussian model across two experiments, providing a better fit to the behavioral data with fewer parameters. Because the causal inference model is derived from a principled understanding of the task, model parameters are directly interpretable in terms of stimulus and subject properties.

  20. Reducing the bias of causality measures

    Science.gov (United States)

    Papana, A.; Kugiumtzis, D.; Larsson, P. G.

    2011-03-01

    Measures of the direction and strength of the interdependence between two time series are evaluated and modified to reduce the bias in the estimation of the measures, so that they give zero values when there is no causal effect. For this, point shuffling is employed as used in the frame of surrogate data. This correction is not specific to a particular measure and it is implemented here on measures based on state space reconstruction and information measures. The performance of the causality measures and their modifications is evaluated on simulated uncoupled and coupled dynamical systems and for different settings of embedding dimension, time series length, and noise level. The corrected measures, and particularly the suggested corrected transfer entropy, turn out to stabilize at the zero level in the absence of a causal effect and detect correctly the direction of information flow when it is present. The measures are also evaluated on electroencephalograms (EEG) for the detection of the information flow in the brain of an epileptic patient. The performance of the measures on EEG is interpreted in view of the results from the simulation study.

  1. Causal tapestries for psychology and physics.

    Science.gov (United States)

    Sulis, William H

    2012-04-01

    Archetypal dynamics is a formal approach to the modeling of information flow in complex systems used to study emergence. It is grounded in the Fundamental Triad of realisation (system), interpretation (archetype) and representation (formal model). Tapestries play a fundamental role in the framework of archetypal dynamics as a formal representational system. They represent information flow by means of multi layered, recursive, interlinked graphical structures that express both geometry (form or sign) and logic (semantics). This paper presents a detailed mathematical description of a specific tapestry model, the causal tapestry, selected for use in describing behaving systems such as appear in psychology and physics from the standpoint of Process Theory. Causal tapestries express an explicit Lorentz invariant transient now generated by means of a reality game. Observables are represented by tapestry informons while subjective or hidden components (for example intellectual and emotional processes) are incorporated into the reality game that determines the tapestry dynamics. As a specific example, we formulate a random graphical dynamical system using causal tapestries.

  2. [Causality in cardiology: concepts in evolution].

    Science.gov (United States)

    Méndez, Gustavo F

    2005-01-01

    This paper describes several concepts about causality from Empedocles, Aristoteles and Galeno, to Koch and Hill and the evolution of these concepts related to cardiovascular diseases. Also defines cause and risk, and the philosophical theories about scientific knowledge: inductive versus refutation analysis. On these basis, the study of cardiovascular disease's causality, especially coronary heart disease, allows us the identification of several risk factors involved in its development. However, even with the presently coronary heart disease risk charts (from Framingham and European studies) the higher probability for the development of a cardiovascular ischemic event is around 40%, establishing an important degree of uncertainty. With the improvement in molecular biology techniques, genetics have attempted to analyse several genetic polymorphisms in search of the origin of coronary heart disease. Unfortunately, less than 10% of these polymorphisms have had a positive correlation with coronary heart disease being of minor risk that those obtained for having the diagnosis of type 2 diabetes mellitus or hypercholesterolemia. On these basis, the requirement of new population research projects in which clinical and genetic risk factors are to be studied for the appropriate understanding of the causality process of cardiovascular diseases must be a worldwide priority.

  3. Bayesian Discovery of Linear Acyclic Causal Models

    CERN Document Server

    Hoyer, Patrik O

    2012-01-01

    Methods for automated discovery of causal relationships from non-interventional data have received much attention recently. A widely used and well understood model family is given by linear acyclic causal models (recursive structural equation models). For Gaussian data both constraint-based methods (Spirtes et al., 1993; Pearl, 2000) (which output a single equivalence class) and Bayesian score-based methods (Geiger and Heckerman, 1994) (which assign relative scores to the equivalence classes) are available. On the contrary, all current methods able to utilize non-Gaussianity in the data (Shimizu et al., 2006; Hoyer et al., 2008) always return only a single graph or a single equivalence class, and so are fundamentally unable to express the degree of certainty attached to that output. In this paper we develop a Bayesian score-based approach able to take advantage of non-Gaussianity when estimating linear acyclic causal models, and we empirically demonstrate that, at least on very modest size networks, its accur...

  4. Serological and molecular identification of Tomato yellow leaf curl virus in Khuzestan province of Iran

    Directory of Open Access Journals (Sweden)

    Shahrokh MALEKZADEH

    2011-09-01

    Full Text Available A survey was conducted from 2006 to 2007 to identify the causal agent of leaf curling of tomato in eight major tomato-growing areas of Khuzestan province in southwest of Iran. Tomato leaf samples showing leaf curling, yellowing, and stunting were collected and screened for the presence of Tomato yellow leaf curl virus (TYLCV by TAS-ELISA. Further confi rmation was completed using graft transmission onto healthy tomato plants and PCR. Results confi rmed that TYLCV is a causal agent of tomato yellow leaf curl disease (TYLCD and is widely distributed in all the major tomato growing areas in southwest of Iran. The nucleotide sequences of the coat protein (CP gene of four isolates (Dezfoul, Shoush, Behbahan, and Ramhormoz were determined and deposited in GenBank (EF199814-7. Phylogenetic analysis of the CP gene further showed that all four Iranian isolates have very close relationship and formed a Compact cluster together with previously sequenced Iranian TYLCV isolates.

  5. How to Be Causal: Time, Spacetime and Spectra

    Science.gov (United States)

    Kinsler, Paul

    2011-01-01

    I explain a simple definition of causality in widespread use, and indicate how it links to the Kramers-Kronig relations. The specification of causality in terms of temporal differential equations then shows us the way to write down dynamical models so that their causal nature "in the sense used here" should be obvious to all. To extend existing…

  6. A developmental approach to learning causal models for cyber security

    Science.gov (United States)

    Mugan, Jonathan

    2013-05-01

    To keep pace with our adversaries, we must expand the scope of machine learning and reasoning to address the breadth of possible attacks. One approach is to employ an algorithm to learn a set of causal models that describes the entire cyber network and each host end node. Such a learning algorithm would run continuously on the system and monitor activity in real time. With a set of causal models, the algorithm could anticipate novel attacks, take actions to thwart them, and predict the second-order effects flood of information, and the algorithm would have to determine which streams of that flood were relevant in which situations. This paper will present the results of efforts toward the application of a developmental learning algorithm to the problem of cyber security. The algorithm is modeled on the principles of human developmental learning and is designed to allow an agent to learn about the computer system in which it resides through active exploration. Children are flexible learners who acquire knowledge by actively exploring their environment and making predictions about what they will find,1, 2 and our algorithm is inspired by the work of the developmental psychologist Jean Piaget.3 Piaget described how children construct knowledge in stages and learn new concepts on top of those they already know. Developmental learning allows our algorithm to focus on subsets of the environment that are most helpful for learning given its current knowledge. In experiments, the algorithm was able to learn the conditions for file exfiltration and use that knowledge to protect sensitive files.

  7. Causal beliefs about depression in different cultural groups—what do cognitive psychological theories of causal learning and reasoning predict?

    OpenAIRE

    York eHagmayer; Neele eEngelmann

    2014-01-01

    Cognitive psychological research focuses on causal learning and reasoning while cognitive anthropological and social science research tend to focus on systems of beliefs. Our aim was to explore how these two types of research can inform each other. Cognitive psychological theories (causal model theory and causal Bayes nets) were used to derive predictions for systems of causal beliefs. These predictions were then applied to lay theories of depression as a specific test case. A systematic lite...

  8. Characteristics of Filoviridae: Marburg and Ebola Viruses

    Science.gov (United States)

    Beer, Brigitte; Kurth, Reinhard; Bukreyev, Alexander

    Filoviruses are enveloped, nonsegmented negative-stranded RNA viruses. The two species, Marburg and Ebola virus, are serologically, biochemically, and genetically distinct. Marburg virus was first isolated during an outbreak in Europe in 1967, and Ebola virus emerged in 1976 as the causative agent of two simultaneous outbreaks in southern Sudan and northern Zaire. Although the main route of infection is known to be person-to-person transmission by intimate contact, the natural reservoir for filoviruses still remains a mystery.

  9. Developing Causal Understanding with Causal Maps: The Impact of Total Links, Temporal Flow, and Lateral Position of Outcome Nodes

    Science.gov (United States)

    Jeong, Allan; Lee, Woon Jee

    2012-01-01

    This study examined some of the methodological approaches used by students to construct causal maps in order to determine which approaches help students understand the underlying causes and causal mechanisms in a complex system. This study tested the relationship between causal understanding (ratio of root causes correctly/incorrectly identified,…

  10. Vaccines to Prevent Cancers Not Caused by Viruses - Annual Plan

    Science.gov (United States)

    We have vaccines against viruses that cause cancer, but what about vaccines for cancers not caused by viruses? Learn about NCI's development of safe and effective vaccines for cancers not caused by infectious agents.

  11. Characterization of a tailless white spot syndrome virus from ...

    African Journals Online (AJOL)

    Jane

    2011-10-17

    , Yangzhou, China. Accepted 15 July, 2011. In this study, a virus similar to the causative agent of white spot syndrome virus (WSSV) but without tail-like extension was identified and characterized from diseased Penaeus ...

  12. Structure and Connectivity Analysis of Financial Complex System Based on G-Causality Network

    Science.gov (United States)

    Xu, Chuan-Ming; Yan, Yan; Zhu, Xiao-Wu; Li, Xiao-Teng; Chen, Xiao-Song

    2013-11-01

    The recent financial crisis highlights the inherent weaknesses of the financial market. To explore the mechanism that maintains the financial market as a system, we study the interactions of U.S. financial market from the network perspective. Applied with conditional Granger causality network analysis, network density, in-degree and out-degree rankings are important indicators to analyze the conditional causal relationships among financial agents, and further to assess the stability of U.S. financial systems. It is found that the topological structure of G-causality network in U.S. financial market changed in different stages over the last decade, especially during the recent global financial crisis. Network density of the G-causality model is much higher during the period of 2007-2009 crisis stage, and it reaches the peak value in 2008, the most turbulent time in the crisis. Ranked by in-degrees and out-degrees, insurance companies are listed in the top of 68 financial institutions during the crisis. They act as the hubs which are more easily influenced by other financial institutions and simultaneously influence others during the global financial disturbance.

  13. Análisis proteómico de Plasmodium, el agente causal de la malaria Proteomic analysis of Plasmodium, the causal agent of Malaria

    Directory of Open Access Journals (Sweden)

    Ivone Castro R

    2009-01-01

    Full Text Available Los plasmodios son protozoarios cuyo complejo ciclo de vida se lleva a cabo en dos hospederos, el vertebrado y el mosquito. La infección de los seres humanos produce la enfermedad conocida como malaria. La secuenciación del genoma de Plasmodium falciparum y el desarrollo de la proteómica han permitido un gran avance en el conocimiento de la biología de este letal parásito. La presente revisión se centra en describir los logros recientes en el estudio del proteoma de Plasmodium falciparum y algunas de las implicaciones en la búsqueda de nuevos fármacos antimaláricos, así como en la generación de vacunas para el control de la enfermedad.Plasmodia are protozoa whose complex life cycle takes place in two different hosts, the vertebrate and the mosquito. The human infection produces the malaria disease. The genome sequence of Plasmodium falciparum and the proteomic tools have enabled a huge advance in knowledge of the biology of this parasite. This review will focus on the recent advances in proteomic studies of Plasmodium falciparum and some implications for the search of new antimalarial drugs as well as vaccines for the control of the disease.

  14. Profile of small interfering RNAs from cotton plants infected with the polerovirus Cotton leafroll dwarf virus

    Directory of Open Access Journals (Sweden)

    Schrago Carlos EG

    2011-08-01

    Full Text Available Abstract Background In response to infection, viral genomes are processed by Dicer-like (DCL ribonuclease proteins into viral small RNAs (vsRNAs of discrete sizes. vsRNAs are then used as guides for silencing the viral genome. The profile of vsRNAs produced during the infection process has been extensively studied for some groups of viruses. However, nothing is known about the vsRNAs produced during infections of members of the economically important family Luteoviridae, a group of phloem-restricted viruses. Here, we report the characterization of a population of vsRNAs from cotton plants infected with Cotton leafroll dwarf virus (CLRDV, a member of the genus Polerovirus, family Luteoviridae. Results Deep sequencing of small RNAs (sRNAs from leaves of CLRDV-infected cotton plants revealed that the vsRNAs were 21- to 24-nucleotides (nt long and that their sequences matched the viral genome, with higher frequencies of matches in the 3- region. There were equivalent amounts of sense and antisense vsRNAs, and the 22-nt class of small RNAs was predominant. During infection, cotton Dcl transcripts appeared to be up-regulated, while Dcl2 appeared to be down-regulated. Conclusions This is the first report on the profile of sRNAs in a plant infected with a virus from the family Luteoviridae. Our sequence data strongly suggest that virus-derived double-stranded RNA functions as one of the main precursors of vsRNAs. Judging by the profiled size classes, all cotton DCLs might be working to silence the virus. The possible causes for the unexpectedly high accumulation of 22-nt vsRNAs are discussed. CLRDV is the causal agent of Cotton blue disease, which occurs worldwide. Our results are an important contribution for understanding the molecular mechanisms involved in this and related diseases.

  15. Virus-vector relationship in the Citrus leprosis pathosystem.

    Science.gov (United States)

    Tassi, Aline Daniele; Garita-Salazar, Laura Cristina; Amorim, Lilian; Novelli, Valdenice Moreira; Freitas-Astúa, Juliana; Childers, Carl C; Kitajima, Elliot W

    2017-03-01

    Citrus leprosis has been one of the most destructive diseases of citrus in the Americas. In the last decade important progress has been achieved such as the complete genome sequencing of its main causal agent, Citrus leprosis virus C (CiLV-C), belonging to a new genus Cilevirus. It is transmitted by Brevipalpus yothersi Baker (Acari: Tenuipalpidae), and is characterized by the localized symptoms it induces on the leaves, fruits and stems. It occurs in the American continents from Mexico to Argentina. The virus was until recently considered restricted to Citrus spp. However, it was found naturally infecting other plants species as Swinglea glutinosa Merrill and Commelina benghalensis L., and has been experimentally transmitted by B. yothersi to a large number of plant species. Despite these advances little is known about the virus-vector relationship that is a key to understanding the epidemiology of the disease. Some components of the CiLV-C/B. yothersi relationship were determined using the common bean (Phaseolus vulgaris L. cv. 'IAC Una') as a test plant. They included: (a) the virus acquisition access period was 4 h; (b) the virus inoculation access period was 2 h; (c) the latent period between acquisition and inoculation was 7 h; (d) the period of retention of the virus by a single viruliferous mite was at least 12 days; (d) the percentage of viruliferous individuals from mite colonies on infected tissues ranged from 25 to 60%. The experiments confirmed previous data that all developmental stages of B. yothersi (larva, protonymph and deutonymph, adult female and male) were able to transmit CiLV-C and that transovarial transmission of the virus did not occur. CiLV-C can be acquired from lesions on leaves, fruits and stems by B. yothersi. Based on the distribution of lesions produced by single viruliferous B. yothersi on bean leaves, it is concluded that they tend to feed in restricted areas, usually near the veins. The short latent and transmission periods

  16. Plum pox virus strains: Diversity and geographical distribution in Serbia

    Directory of Open Access Journals (Sweden)

    Darko Jevremović

    2014-06-01

    Full Text Available Plum pox virus (PPV is the causal agent of Sharka disease. Since its discovery, Sharka has been considered as a calamity in plum orchards. PPV is present worldwide in many Prunus species, causing great economic losses. In highly susceptible plum varieties, such as Požegača, PPV causes a premature fruit drop and reduces fruit quality, which leads to total yield loss. Eight PPV strains (PPV-M, PPV-D, PPV-EA, PPV-C, PPV-Rec, PPV-W, PPV-T and PPVCR have been recognized so far. Three major strains (PPV-M, PPV-D and PPV-Rec are the most widely dispersed and occur frequently in many European countries. Other strains are of minor importance due to their limited host preferences or geographic distribution. So far, all three major strains have been identified in Serbia. In this paper, we provide a comprehensive overview of the research into Plum pox virus variability in Serbia.

  17. Sharka: how do plants respond to Plum pox virus infection?

    Science.gov (United States)

    Clemente-Moreno, María J; Hernández, José A; Diaz-Vivancos, Pedro

    2015-01-01

    Plum pox virus (PPV), the causal agent of sharka disease, is one of the most studied plant viruses, and major advances in detection techniques, genome characterization and organization, gene expression, transmission, and the description of candidate genes involved in PPV resistance have been described. However, information concerning the plant response to PPV infection is very scarce. In this review, we provide an updated summary of the research carried out to date in order to elucidate how plants cope with PPV infection and their response at different levels, including the physiological, biochemical, proteomic, and genetic levels. Knowledge about how plants respond to PPV infection can contribute to the development of new strategies to cope with this disease. Due to the fact that PPV induces an oxidative stress in plants, the bio-fortification of the antioxidative defences, by classical or biotechnological approaches, would be a useful tool to cope with PPV infection. Nevertheless, there are still some gaps in knowledge related to PPV-plant interaction that remain to be filled, such as the effect of PPV on the hormonal profile of the plant or on the plant metabolome. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. Detection and quantification of Chilean strains of infectious pancreatic necrosis virus by real-time RT-PCR assays using segment B as a target Detección y cuantificación de cepas chilenas del virus de la necrosis pancreática infecciosa por medio de la técnica de RT-PCR en tiempo real usando el segmento B como objetivo

    Directory of Open Access Journals (Sweden)

    Yoanna Eissler

    2011-11-01

    Full Text Available Infectious pancreatic necrosis virus (IPNV is the causal agent of a highly prevalent disease that affects salmonid fish, mostly during their fresh water life period. Like many other viruses, IPNV produces highly heterogeneous populations. Therefore, diagnostic methods need to be checked constantly so that no variants of the virus escape detection. The IPNV genome is composed of two double-stranded RNA segments: A and B, polymerase chain reaction (PCR methods normally use segment A as a target. In order to develop an optimized protocol to diagnose IPNV, we present a real-time RT-PCR (reverse transcription technique, using primers designed to recognize segment B of the virus. To validate the ubiquity of the primers used, the IPNV isolates tested were sequenced and compared with previously published cladograms, which include a wide spectrum of genogroups. These primers made it possible to detect viral isolates belonging to genogroups 1 and 5, which were obtained from different locations linked to fish farming. As expected, we were able to detect the virus from distant Aquabirnavirus genogroups.El virus de la necrosis pancreática infecciosa (IPNV es el agente causal de una enfermedad altamente prevalente que afecta a peces salmónidos, principalmente durante su período de vida en agua dulce. IPNV, así como muchos otros virus, produce poblaciones altamente heterogéneas. Por lo tanto los métodos de diagnóstico necesitan ser constantemente revisados para evitar que ciertas variantes del virus escapen de la detección. El genoma del IPNV está compuesto por dos segmentos de ARN de doble hebra, A y B, los métodos de PCR (reacción en cadena de la polimerasa normalmente usan el fragmento A como blanco. Con el propósito de generar un protocolo optimizado para el diagnóstico del IPNV, se presenta una técnica de RT-PCR (transcripción reversa- en tiempo real, usando partidores diseñados para reconocer el segmento B del virus. Para validar la

  19. A Causal Theory of Mnemonic Confabulation

    Directory of Open Access Journals (Sweden)

    Sven Bernecker

    2017-07-01

    Full Text Available This paper attempts to answer the question of what defines mnemonic confabulation vis-à-vis genuine memory. The two extant accounts of mnemonic confabulation as “false memory” and as ill-grounded memory are shown to be problematic, for they cannot account for the possibility of veridical confabulation, ill-grounded memory, and well-grounded confabulation. This paper argues that the defining characteristic of mnemonic confabulation is that it lacks the appropriate causal history. In the confabulation case, there is no proper counterfactual dependence of the state of seeming to remember on the corresponding past representation.

  20. A Causal Theory of Mnemonic Confabulation.

    Science.gov (United States)

    Bernecker, Sven

    2017-01-01

    This paper attempts to answer the question of what defines mnemonic confabulation vis-à-vis genuine memory. The two extant accounts of mnemonic confabulation as "false memory" and as ill-grounded memory are shown to be problematic, for they cannot account for the possibility of veridical confabulation, ill-grounded memory, and well-grounded confabulation. This paper argues that the defining characteristic of mnemonic confabulation is that it lacks the appropriate causal history. In the confabulation case, there is no proper counterfactual dependence of the state of seeming to remember on the corresponding past representation.

  1. Bianchi-I cosmology from causal thermodynamics

    CERN Document Server

    Bittencourt, Eduardo; Klippert, Renato

    2016-01-01

    We investigate diagonal Bianchi-I spacetimes in the presence of viscous fluids by using the shear and the anisotropic pressure components as the basic variables, where the viscosity is driven by the (second-order) causal thermodynamics. A few exact solutions are presented, among which we mention the anisotropic versions of de Sitter/anti-de Sitter geometries as well as an asymptotically isotropic spacetime presenting an effective constant cosmic acceleration without any cosmological constant. The qualitative analysis of the solutions for barotropic fluids with linear equations of state suggests that the behaviour is quite general.

  2. On asymmetric causal relationships in Petropolitics

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    Balan Feyza

    2016-01-01

    Full Text Available The aim of this paper is to examine whether the First Law of Petropolitics denominated by Friedman in 2006 is valid for OPEC countries. To do this, this paper analyses the relationship between political risk and oil supply by applying the asymmetric panel causality test suggested by Hatemi-J (2011 to these countries for the period 1984-2014. The results show that the First Law of Petropolitics is valid for Angola, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, and the UAE, given that positive oil supply shocks significantly lead to negative political stability shocks, and negative oil supply shocks significantly lead to positive shocks in political stability.

  3. The semiclassical limit of causal dynamical triangulations

    Energy Technology Data Exchange (ETDEWEB)

    Ambjorn, J., E-mail: ambjorn@nbi.d [Niels Bohr Institute, Copenhagen University, Blegdamsvej 17, DK-2100 Copenhagen O (Denmark); Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, NL-3584 CE Utrecht (Netherlands); Goerlich, A., E-mail: atg@th.if.uj.edu.p [Institute of Physics, Jagellonian University, Reymonta 4, PL 30-059 Krakow (Poland); Jurkiewicz, J., E-mail: jurkiewicz@th.if.uj.edu.p [Institute of Physics, Jagellonian University, Reymonta 4, PL 30-059 Krakow (Poland); Loll, R., E-mail: r.loll@uu.n [Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, NL-3584 CE Utrecht (Netherlands); Perimeter Institute for Theoretical Physics, 31 Caroline St. N., Waterloo, Ontario, N2L 2Y5 (Canada); Gizbert-Studnicki, J., E-mail: jakub.gizbert-studnicki@uj.edu.p [Institute of Physics, Jagellonian University, Reymonta 4, PL 30-059 Krakow (Poland); Trzesniewski, T., E-mail: t.trzesniewski@uj.edu.p [Institute of Physics, Jagellonian University, Reymonta 4, PL 30-059 Krakow (Poland)

    2011-08-01

    Previous work has shown that the macroscopic structure of the theory of quantum gravity defined by causal dynamical triangulations (CDT) is compatible with that of a de Sitter universe. After emphasizing the strictly nonperturbative nature of this semiclassical limit we present a detailed study of the three-volume data, which allows us to re-confirm the de Sitter structure, exhibit short-distance discretization effects, and make a first detailed investigation of the presence of higher-order curvature terms in the effective action for the scale factor. Technically, we make use of a novel way of fixing the total four-volume in the simulations.

  4. ECHO virus

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001340.htm ECHO virus To use the sharing features on this page, please enable JavaScript. Enteric cytopathic human orphan (ECHO) viruses are a group of viruses that can lead ...

  5. Toxicology and Epidemiology: Improving the Science with a Framework for Combining Toxicological and Epidemiological Evidence to Establish Causal Inference

    Science.gov (United States)

    Adami, Hans-Olov; Berry, Sir Colin L.; Breckenridge, Charles B.; Smith, Lewis L.; Swenberg, James A.; Trichopoulos, Dimitrios; Weiss, Noel S.; Pastoor, Timothy P.

    2011-01-01

    Historically, toxicology has played a significant role in verifying conclusions drawn on the basis of epidemiological findings. Agents that were suggested to have a role in human diseases have been tested in animals to firmly establish a causative link. Bacterial pathogens are perhaps the oldest examples, and tobacco smoke and lung cancer and asbestos and mesothelioma provide two more recent examples. With the advent of toxicity testing guidelines and protocols, toxicology took on a role that was intended to anticipate or predict potential adverse effects in humans, and epidemiology, in many cases, served a role in verifying or negating these toxicological predictions. The coupled role of epidemiology and toxicology in discerning human health effects by environmental agents is obvious, but there is currently no systematic and transparent way to bring the data and analysis of the two disciplines together in a way that provides a unified view on an adverse causal relationship between an agent and a disease. In working to advance the interaction between the fields of toxicology and epidemiology, we propose here a five-step “Epid-Tox” process that would focus on: (1) collection of all relevant studies, (2) assessment of their quality, (3) evaluation of the weight of evidence, (4) assignment of a scalable conclusion, and (5) placement on a causal relationship grid. The causal relationship grid provides a clear view of how epidemiological and toxicological data intersect, permits straightforward conclusions with regard to a causal relationship between agent and effect, and can show how additional data can influence conclusions of causality. PMID:21561883

  6. 9 CFR 121.5 - Exemptions for VS select agents and toxins.

    Science.gov (United States)

    2010-01-01

    ... virus, avian influenza virus (highly pathogenic), bovine spongiform encephalopathy agent, classical... grant a specific exemption upon a showing of good cause and upon his or her determination that such...

  7. Influenza virus isolation.

    Science.gov (United States)

    Krauss, Scott; Walker, David; Webster, Robert G

    2012-01-01

    The isolation of influenza viruses is important for the diagnosis of respiratory diseases in lower animals and humans, for the detection of the infecting agent in surveillance programs, and is an essential element in the development and production of vaccine. Since influenza is caused by a zoonotic virus it is necessary to do surveillance in the reservoir species (aquatic waterfowls), intermediate hosts (quails, pigs), and in affected mammals including humans. Two of the hemagglutinin (HA) subtypes of influenza A viruses (H5 and H7) can evolve into highly pathogenic (HP) strains for gallinaceous poultry; some HP H5 and H7 strains cause lethal infection of humans. In waterfowls, low pathogenic avian influenza (LPAI) isolates are obtained primarily from the cloaca (or feces); in domestic poultry, the virus is more often recovered from the respiratory tract than from cloacal samples; in mammals, the virus is most often isolated from the respiratory tract, and in cases of high pathogenic avian influenza (HPAI) from the blood and internal organs of infected birds. Virus isolation procedures are performed by inoculation of clinical specimens into embryonated eggs (primarily chicken eggs) or onto a variety of primary or continuous tissue culture systems. Successful isolation of influenza virus depends on the quality of the sample and matching the appropriate culture method to the sample type.

  8. Foundational perspectives on causality in large-scale brain networks

    Science.gov (United States)

    Mannino, Michael; Bressler, Steven L.

    2015-12-01

    A profusion of recent work in cognitive neuroscience has been concerned with the endeavor to uncover causal influences in large-scale brain networks. However, despite the fact that many papers give a nod to the important theoretical challenges posed by the concept of causality, this explosion of research has generally not been accompanied by a rigorous conceptual analysis of the nature of causality in the brain. This review provides both a descriptive and prescriptive account of the nature of causality as found within and between large-scale brain networks. In short, it seeks to clarify the concept of causality in large-scale brain networks both philosophically and scientifically. This is accomplished by briefly reviewing the rich philosophical history of work on causality, especially focusing on contributions by David Hume, Immanuel Kant, Bertrand Russell, and Christopher Hitchcock. We go on to discuss the impact that various interpretations of modern physics have had on our understanding of causality. Throughout all this, a central focus is the distinction between theories of deterministic causality (DC), whereby causes uniquely determine their effects, and probabilistic causality (PC), whereby causes change the probability of occurrence of their effects. We argue that, given the topological complexity of its large-scale connectivity, the brain should be considered as a complex system and its causal influences treated as probabilistic in nature. We conclude that PC is well suited for explaining causality in the brain for three reasons: (1) brain causality is often mutual; (2) connectional convergence dictates that only rarely is the activity of one neuronal population uniquely determined by another one; and (3) the causal influences exerted between neuronal populations may not have observable effects. A number of different techniques are currently available to characterize causal influence in the brain. Typically, these techniques quantify the statistical

  9. Causal network inference using biochemical kinetics.

    Science.gov (United States)

    Oates, Chris J; Dondelinger, Frank; Bayani, Nora; Korkola, James; Gray, Joe W; Mukherjee, Sach

    2014-09-01

    Networks are widely used as structural summaries of biochemical systems. Statistical estimation of networks is usually based on linear or discrete models. However, the dynamics of biochemical systems are generally non-linear, suggesting that suitable non-linear formulations may offer gains with respect to causal network inference and aid in associated prediction problems. We present a general framework for network inference and dynamical prediction using time course data that is rooted in non-linear biochemical kinetics. This is achieved by considering a dynamical system based on a chemical reaction graph with associated kinetic parameters. Both the graph and kinetic parameters are treated as unknown; inference is carried out within a Bayesian framework. This allows prediction of dynamical behavior even when the underlying reaction graph itself is unknown or uncertain. Results, based on (i) data simulated from a mechanistic model of mitogen-activated protein kinase signaling and (ii) phosphoproteomic data from cancer cell lines, demonstrate that non-linear formulations can yield gains in causal network inference and permit dynamical prediction and uncertainty quantification in the challenging setting where the reaction graph is unknown. MATLAB R2014a software is available to download from warwick.ac.uk/chrisoates. Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press.

  10. Are bruxism and the bite causally related?

    Science.gov (United States)

    Lobbezoo, F; Ahlberg, J; Manfredini, D; Winocur, E

    2012-07-01

    In the dental profession, the belief that bruxism and dental (mal-)occlusion ('the bite') are causally related is widespread. The aim of this review was to critically assess the available literature on this topic. A PubMed search of the English-language literature, using the query 'Bruxism [Majr] AND (Dental Occlusion [Majr] OR Malocclusion [Majr])', yielded 93 articles, of which 46 papers were finally included in the present review*. Part of the included publications dealt with the possible associations between bruxism and aspects of occlusion, from which it was concluded that neither for occlusal interferences nor for factors related to the anatomy of the oro-facial skeleton, there is any evidence available that they are involved in the aetiology of bruxism. Instead, there is a growing awareness of other factors (viz. psychosocial and behavioural ones) being important in the aetiology of bruxism. Another part of the included papers assessed the possible mediating role of occlusion between bruxism and its purported consequences (e.g. tooth wear, loss of periodontal tissues, and temporomandibular pain and dysfunction). Even though most dentists agree that bruxism may have several adverse effects on the masticatory system, for none of these purported adverse effects, evidence for a mediating role of occlusion and articulation has been found to date. Hence, based on this review, it should be concluded that to date, there is no evidence whatsoever for a causal relationship between bruxism and the bite. © 2012 Blackwell Publishing Ltd.

  11. Evidence for online processing during causal learning.

    Science.gov (United States)

    Liu, Pei-Pei; Luhmann, Christian C

    2015-03-01

    Many models of learning describe both the end product of learning (e.g., causal judgments) and the cognitive mechanisms that unfold on a trial-by-trial basis. However, the methods employed in the literature typically provide only indirect evidence about the unfolding cognitive processes. Here, we utilized a simultaneous secondary task to measure cognitive processing during a straightforward causal-learning task. The results from three experiments demonstrated that covariation information is not subject to uniform cognitive processing. Instead, we observed systematic variation in the processing dedicated to individual pieces of covariation information. In particular, observations that are inconsistent with previously presented covariation information appear to elicit greater cognitive processing than do observations that are consistent with previously presented covariation information. In addition, the degree of cognitive processing appears to be driven by learning per se, rather than by nonlearning processes such as memory and attention. Overall, these findings suggest that monitoring learning processes at a finer level may provide useful psychological insights into the nature of learning.

  12. Causal-Explanatory Pluralism: How Intentions, Functions, and Mechanisms Influence Causal Ascriptions

    Science.gov (United States)

    Lombrozo, Tania

    2010-01-01

    Both philosophers and psychologists have argued for the existence of distinct kinds of explanations, including teleological explanations that cite functions or goals, and mechanistic explanations that cite causal mechanisms. Theories of causation, in contrast, have generally been unitary, with dominant theories focusing either on counterfactual…

  13. God Does Not Play Dice: Causal Determinism and Preschoolers' Causal Inferences

    Science.gov (United States)

    Schulz, Laura E.; Sommerville, Jessica

    2006-01-01

    Three studies investigated children's belief in causal determinism. If children are determinists, they should infer unobserved causes whenever observed causes appear to act stochastically. In Experiment 1, 4-year-olds saw a stochastic generative cause and inferred the existence of an unobserved inhibitory cause. Children traded off inferences…

  14. Quantum causality conceptual issues in the causal theory of quantum mechanics

    CERN Document Server

    Riggs, Peter J; French, Steven RD

    2009-01-01

    This is a treatise devoted to the foundations of quantum physics and the role that causality plays in the microscopic world governed by the laws of quantum mechanics. The book is controversial and will engender some lively debate on the various issues raised.

  15. Viruses, virophages, and their living nature.

    Science.gov (United States)

    Ruiz-Saenz, J; Rodas, J D

    2010-01-01

    Over 100 years viruses have fascinated scientists around the world. Although biologists, chemists, physicians, veterinarians, and even physicists attempted to elucidate the nature of viruses, the question still remains "Are viruses alive?" Different theories have aimed at unifying our views of virology to provide an answer. However, the discovery of a mimivirus, its genome organization and replication cycle, in addition to the recently found virophage challenged the established frontier between viruses and parasitic cellular organisms. Consequently, the old controversy whether viruses are inert agents at the threshold of life or a different form of life was reignited. This review reopens the debate about the living nature of viruses from the classical concepts to the recent discoveries in order to rationally discuss our beliefs about the living or non-living character of viruses. filterable agent; mimivirus; virophage.

  16. Agent Based Reasoning in Multilevel Flow Modeling

    DEFF Research Database (Denmark)

    Lind, Morten; Zhang, Xinxin

    2012-01-01

    to launch the MFM Workbench into an agent based environment, which can complement disadvantages of the original software. The agent-based MFM Workbench is centered on a concept called “Blackboard System” and use an event based mechanism to arrange the reasoning tasks. This design will support the new......Multilevel Flow Modeling (MFM) is a modeling method used for modeling complex industrial plant. Currently, MFM is supported with a standalone software tool called MFM Workbench, which is equipped with causal-relation analysis and other functionalities. The aim of this paper is to offer a new design...

  17. The role of counterfactual theory in causal reasoning.

    Science.gov (United States)

    Maldonado, George

    2016-10-01

    In this commentary I review the fundamentals of counterfactual theory and its role in causal reasoning in epidemiology. I consider if counterfactual theory dictates that causal questions must be framed in terms of well-defined interventions. I conclude that it does not. I hypothesize that the interventionist approach to causal inference in epidemiology stems from elevating the randomized trial design to the gold standard for thinking about causal inference. I suggest that instead the gold standard we should use for thinking about causal inference in epidemiology is the thought experiment that, for example, compares an actual disease frequency under one exposure level with a counterfactual disease frequency under a different exposure level (as discussed in Greenland and Robins (1986) and Maldonado and Greenland (2002)). I also remind us that no method should be termed "causal" unless it addresses the effect of other biases in addition to the problem of confounding. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Restrictions for the causal inferences in an interferometric system

    Science.gov (United States)

    Rossi, R.

    2017-07-01

    Causal discovery algorithms allow for the inference of causal structures from probabilistic relations of random variables. A natural field for the application of this tool is quantum mechanics, where a long-standing debate about the role of causality in the theory has flourished since its early days. In this paper, a causal discovery algorithm is applied in the search for causal models to describe a quantum version of Wheeler's delayed-choice experiment. The outputs explicitly show the restrictions for the introduction of classical concepts in this system. The exclusion of models with two hidden variables is one of them. A consequence of such a constraint is the impossibility to construct a causal model that avoids superluminal causation and assumes an objective view of the wave and particle properties simultaneously.

  19. Animal Models of Virus-Induced Neurobehavioral Sequelae: Recent Advances, Methodological Issues, and Future Prospects

    Directory of Open Access Journals (Sweden)

    Marco Bortolato

    2010-01-01

    Full Text Available Converging lines of clinical and epidemiological evidence suggest that viral infections in early developmental stages may be a causal factor in neuropsychiatric disorders such as schizophrenia, bipolar disorder, and autism-spectrum disorders. This etiological link, however, remains controversial in view of the lack of consistent and reproducible associations between viruses and mental illness. Animal models of virus-induced neurobehavioral disturbances afford powerful tools to test etiological hypotheses and explore pathophysiological mechanisms. Prenatal or neonatal inoculations of neurotropic agents (such as herpes-, influenza-, and retroviruses in rodents result in a broad spectrum of long-term alterations reminiscent of psychiatric abnormalities. Nevertheless, the complexity of these sequelae often poses methodological and interpretational challenges and thwarts their characterization. The recent conceptual advancements in psychiatric nosology and behavioral science may help determine new heuristic criteria to enhance the translational value of these models. A particularly critical issue is the identification of intermediate phenotypes, defined as quantifiable factors representing single neurochemical, neuropsychological, or neuroanatomical aspects of a diagnostic category. In this paper, we examine how the employment of these novel concepts may lead to new methodological refinements in the study of virus-induced neurobehavioral sequelae through animal models.

  20. Causality and Responsibility for Formal Verification and Beyond

    Directory of Open Access Journals (Sweden)

    Hana Chockler

    2016-08-01

    Full Text Available The theory of actual causality, defined by Halpern and Pearl, and its quantitative measure - the degree of responsibility - was shown to be extremely useful in various areas of computer science due to a good match between the results it produces and our intuition. In this paper, I describe the applications of causality to formal verification, namely, explanation of counterexamples, refinement of coverage metrics, and symbolic trajectory evaluation. I also briefly discuss recent applications of causality to legal reasoning.