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Sample records for mutant elicited suilysin-neutralization

  1. Rhizobium meliloti exopolysaccharide mutants elicit feedback regulation of nodule formation in alfalfa

    SciTech Connect

    Caetano-Anolles, G.; Lagares, A.; Bauer, W.D. )

    1990-02-01

    Nodule formation by wild-type Rhizobium meliloti is strongly suppressed in younger parts of alfalfa (Medicago sativum L.) root systems as a feedback response to development of the first nodules. Mutants of R. meliloti deficient in exopolysaccharide synthesis can induce the formation of organized nodular structures (pseudonodules) on alfalfa roots but are defective in their ability to invade and multiply within host tissues. The formation of empty pseudonodules by exo mutants was found to elicit a feedback suppression of nodule formation similar to that elicited by the wild-type bacteria. Inoculation of an exo mutant onto one side of a split-root system 24 hours before inoculation of the second side with wild-type cells suppressed wild-type nodule formation on the second side in proportion to the extent of pseudonodule formation by the exo mutants. The formation of pseudonodules is thus sufficient to elicit systemic feedback control of nodulation in the host root system: infection thread development and internal proliferation of the bacteria are not required for elicitation of feedback. Pseudonodule formation by the exo mutants was found to be strongly suppressed in split-root systems by prior inoculation on the opposite side with the wild type. Thus, feedback control elicited by the wild-type inhibits Rhizobium-induced redifferentiation of host root cells.

  2. Salmonella DNA Adenine Methylase Mutants Elicit Protective Immune Responses to Homologous and Heterologous Serovars in Chickens

    PubMed Central

    Dueger, E. L.; House, J. K.; Heithoff, D. M.; Mahan, M. J.

    2001-01-01

    Salmonella DNA adenine methylase (Dam) mutants that lack or overproduce Dam are highly attenuated for virulence in mice and confer protection against murine typhoid fever. To determine whether vaccines based on Dam are efficacious in poultry, a Salmonella Dam− vaccine was evaluated in the protection of chicken broilers against oral challenge with homologous and heterologous Salmonella serovars. A Salmonella enterica serovar Typhimurium Dam− vaccine strain was attenuated for virulence in day-of-hatch chicks more than 100,000-fold. Vaccination of chicks elicited cross-protective immune responses, as evidenced by reduced colonization (10- to 10,000-fold) of the gastrointestinal tract (ileum, cecum, and feces) and visceral organs (bursa and spleen) after challenge with homologous (Typhimurium F98) and heterologous (Enteritidis 4973 and S. enterica O6,14,24: e,h-monophasic) Salmonella serovars that are implicated in Salmonella infection of poultry. The protection conferred was observed for the organ or the maximum CFU/tissue/bird as a unit of analysis, suggesting that Dam mutant strains may serve as the basis for the development of efficacious poultry vaccines for the containment of Salmonella. PMID:11705984

  3. Amphetamine-elicited striatal Fos expression is attenuated in neurotensin null mutant mice.

    PubMed

    Fadel, Jim; Dobner, Paul R; Deutch, Ariel Y

    2006-07-10

    Neurotensin (NT) has been suggested to interact with dopamine systems in different forebrain sites to exert both antipsychotic- and psychostimulant-like effects. We previously found that genetic or pharmacological manipulations that disrupt endogenous NT signaling attenuate antipsychotic drug-induced Fos expression in the dorsolateral and central striatum but not other striatal regions. To assess the role of NT in psychostimulant responses, we examined the ability of d-amphetamine (AMP) to induce Fos in wild-type and NT null mutant mice. AMP-elicited Fos expression was significantly attenuated in the medial striatum of NT null mutant mice, but was unaffected in other striatal territories. Similar results were obtained in rats and mice pretreated with the high affinity neurotensin receptor (NTR1) antagonist SR 48692. The effect of the NTR1 antagonist was particularly apparent in the striatal patch (striosome) compartment, as defined by mu-opioid receptor immunoreactivity. These data suggest that NT is required for the full activation by AMP of medial striatal neurons.

  4. Mutant LRRK2 elicits calcium imbalance and depletion of dendritic mitochondria in neurons.

    PubMed

    Cherra, Salvatore J; Steer, Erin; Gusdon, Aaron M; Kiselyov, Kirill; Chu, Charleen T

    2013-02-01

    Mutations in the leucine-rich repeat kinase 2 (LRRK2) have been associated with familial and sporadic cases of Parkinson disease. Mutant LRRK2 causes in vitro and in vivo neurite shortening, mediated in part by autophagy, and a parkinsonian phenotype in transgenic mice; however, the underlying mechanisms remain unclear. Because mitochondrial content/function is essential for dendritic morphogenesis and maintenance, we investigated whether mutant LRRK2 affects mitochondrial homeostasis in neurons. Mouse cortical neurons expressing either LRRK2 G2019S or R1441C mutations exhibited autophagic degradation of mitochondria and dendrite shortening. In addition, mutant LRRK2 altered the ability of the neurons to buffer intracellular calcium levels. Either calcium chelators or inhibitors of voltage-gated L-type calcium channels prevented mitochondrial degradation and dendrite shortening. These data suggest that mutant LRRK2 causes a deficit in calcium homeostasis, leading to enhanced mitophagy and dendrite shortening. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  5. Cross-protective Immunity Against Leptospirosis Elicited by a Live, Attenuated Lipopolysaccharide Mutant

    PubMed Central

    Srikram, Amporn; Zhang, Kunkun; Bartpho, Thanatchaporn; Lo, Miranda; Hoke, David E.; Sermswan, Rasana W.; Adler, Ben

    2011-01-01

    Background. Leptospira species cause leptospirosis, a zoonotic disease found worldwide. Current vaccines against leptospirosis provide protection only against closely related serovars. Methods. We evaluated an attenuated transposon mutant of Leptospira interrogans serovar Manilae (M1352, defective in lipopolysaccharide biosynthesis) as a live vaccine against leptospirosis. Hamsters received a single dose of vaccine and were challenged with the homologous serovar (Manilae) and a serologically unrelated heterologous serovar (Pomona). Comparisons were made with killed vaccines. Potential cross-protective antigens against leptospirosis were investigated. Results. Live M1352 vaccine induced superior protection in hamsters against homologous challenge. The live vaccine also stimulated cross-protection against heterologous challenge, with 100% survival (live M1352) versus 40% survival (killed vaccine). Hamsters receiving either vaccine responded to the dominant membrane proteins LipL32 and LipL41. Hamsters receiving the live vaccine additionally recognized LA3961/OmpL36 (unknown function), Loa22 (OmpA family protein, recognized virulence factor), LA2372 (general secretory protein G), and LA1939 (hypothetical protein). Manilae LigA was recognized by M1352 vaccinates, whereas LipL36 was detected in Pomona. Conclusion. This study demonstrated that a live, attenuated vaccine can stimulate cross-protective immunity to L. interrogans and has identified antigens that potentially confer cross-protection against leptospirosis. PMID:21220775

  6. Wheat streak mosaic virus Coat Protein Deletion Mutants Elicit More Severe Symptoms than Wild-Type Virus in Multiple Cereal Hosts.

    PubMed

    Tatineni, Satyanarayana; ELowsky, Christian; Graybosch, Robert

    2017-08-25

    Previously, we reported that coat protein (CP) of Wheat streak mosaic virus (WSMV; genus Tritimovirus, family Potyviridae) tolerates deletion of amino acids 36 to 84 for efficient systemic infection of wheat. In this study, we demonstrated that WSMV mutants with deletion of CP amino acids 58 to 84, but not 36 to 57, induced severe chlorotic streaks and spots, followed by acute chlorosis in wheat, maize, barley, and rye compared to mild to moderate chlorotic streaks and mosaic symptoms by wild-type virus. Deletion of CP amino acids 58 to 84 from WSMV genome accelerated cell-to-cell movement with increased accumulation of genomic RNAs and CP compared to wild-type virus. Microscopic examination of wheat tissues infected by GFP-tagged mutants revealed that infection by mutants lacking CP amino acids 58 to 84 caused degradation of chloroplasts, resulting in acute macroscopic chlorosis. The profile of CP-specific proteins was altered in wheat infected by mutants causing acute chlorosis compared to mutants eliciting wild-type symptoms. All deletion mutants accumulated CP-specific major protein similar to wild-type virus; however, mutants that elicit acute chlorosis failed to accumulate a 31-kDa minor protein compared to wild-type virus or mutants lacking amino acids 36 to 57. Taken together, these data suggest that deletion of CP amino acids 58 to 84 from WSMV genome enhanced accumulation of CP and genomic RNA, altered CP-specific protein profiles, and caused severe symptom phenotypes in multiple cereal hosts.

  7. HPV11 mutant virus-like particles elicit immune responses that neutralize virus and delineate a novel neutralizing domain.

    PubMed

    Ludmerer, S W; McClements, W L; Wang, X M; Ling, J C; Jansen, K U; Christensen, N D

    2000-01-20

    Characterization of the regions of human papillomaviruses (HPVs) that elicit neutralizing immune responses supports studies on viral infectivity and provides insight for the development and evaluation of prophylactic vaccines. HPV11 is a major etiologic agent of genital warts and a likely vaccine candidate. A conformationally dependent epitope for the binding of three neutralizing monoclonal antibodies (mAbs) has been mapped to residues G(131)T(132) of the L1 major capsid protein. The mAbs bind L1 only when it is assembled into virions or into virus-like particles (VLPs) that mimic the capsid structure. We were interested in identifying other domains of L1 that elicit neutralizing responses. To this end, we have generated a panel of mAbs against VLPs derived from HPV11 L1 harboring a G131S substitution. The new mAbs are unlike the neutralizing mAbs previously mapped to residues G(131)T(132) in that they bind both prototype and HPV11:G131S mutant VLPs. Some of the new mAbs neutralized virus in vitro. We have mapped epitopes for three of these new mAbs, as well as a neutralizing mAb generated against HPV11 virions, by measuring binding to HPV6 VLPs substituted with HPV11-like amino acids. Two regions are critical: one defined by HPV11 L1 residues 263-290 and the other by residues 346-349. mAbs H11.H3 and H11.G131S.G3 bind HPV6 VLPs with substitutions derived from the 346-349 region; in addition, H11.G131S.G3 binds HPV6 VLPs with substitutions derived only from the 263-290 region. Although H11.H3 does not bind HPV6 VLPs with substitutions derived from the 263-290 region, binding to HPV6 VLPs is enhanced when both sets of substitutions are present. mAbs H11.G131S.I1 and H11.G131S.K5 bind HPV6 VLPs with the 263-290 substitutions, but show little binding to HPV6 VLPs with the 346-349 substitutions. However, binding to HPV6 VLPs is enhanced when substitutions at both regions are present. The 346-349 region has not previously been described as eliciting a neutralizing

  8. Microglial PHOX and Mac-1 are essential to the enhanced dopaminergic neurodegeneration elicited by A30P and A53T mutant alpha-synuclein.

    PubMed

    Zhang, Wei; Dallas, Shannon; Zhang, Dan; Guo, Jian-Ping; Pang, Hao; Wilson, Belinda; Miller, David S; Chen, Biao; Zhang, Wanqin; McGeer, Patrick L; Hong, Jau-Shyong; Zhang, Jing

    2007-08-15

    alpha-Synuclein, a gene whose mutations, duplication, and triplication has been linked to autosomal dominant familial Parkinson's disease (fPD), appears to play a central role in the pathogenesis of sporadic PD (sPD) as well. Enhancement of neurodegeneration induced by mutant alpha-synuclein has been attributed to date largely to faster formation of alpha-synuclein aggregates in neurons. Recently, we reported that microglial activation enhances wild type (WT) alpha-synuclein-elicited dopaminergic neurodegeneration. In the present study, using a primary mesencephalic culture system, we tested whether mutated alpha-synuclein could activate microglia more powerfully than WT alpha-synuclein, thereby contributing to the accelerated neurodegeneration observed in fPD. The results showed that alpha-synuclein with the A30P or A53T mutations caused greater microglial activation than WT alpha-synuclein. Furthermore, the extent of microglial activation paralleled the degree of dopaminergic neurotoxicity induced by WT and mutant alpha-synuclein. Mutant alpha-synuclein also induced greater production of reactive oxygen species than WT alpha-synuclein by NADPH oxidase (PHOX), and PHOX activation was linked to direct activation of macrophage antigen-1 (Mac-1) receptor, rather than alpha-synuclein internalization via scavenger receptors. These results have, for the first time, demonstrated that microglia are also critical in enhanced neurotoxicity induced by mutant alpha-synuclein. (c) 2007 Wiley-Liss, Inc.

  9. DNA vaccine elicits an efficient antitumor response by targeting the mutant Kras in a transgenic mouse lung cancer model.

    PubMed

    Weng, T-Y; Yen, M-C; Huang, C-T; Hung, J-J; Chen, Y-L; Chen, W-C; Wang, C-Y; Chang, J-Y; Lai, M-D

    2014-10-01

    Mutant Kras (V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) is observed in more than 20% of non-small-cell lung cancers; however, no effective Kras target therapy is available at present. The Kras DNA vaccine may represent as a novel immunotherapeutic agent in lung cancer. In this study, we investigated the antitumor efficacy of the Kras DNA vaccine in a genetically engineered inducible mouse lung tumor model driven by Kras(G12D). Lung tumors were induced by doxycycline, and the therapeutic effects of Kras DNA vaccine were evaluated with delivery of Kras(G12D) plasmids. Mutant Kras(G12D) DNA vaccine significantly decreased the tumor nodules. A dominant-negative mutant Kras(G12D)N17, devoid of oncogenic activity, achieved similar therapeutic effects. The T-helper 1 immune response was enhanced in mice treated with Kras DNA vaccine. Splenocytes from mice receiving Kras DNA vaccine presented an antigen-specific response by treatment with peptides of Kras but not Hras or OVA. The number of tumor-infiltrating CD8(+) T cells increased after Kras vaccination. In contrast, Kras DNA vaccine was not effective in the lung tumor in transgenic mice, which was induced by mutant L858R epidermal growth factor receptor. Overall, these results indicate that Kras DNA vaccine produces an effective antitumor response in transgenic mice, and may be useful in treating lung cancer-carrying Ras mutation.

  10. The targeted overexpression of a Claudin mutant in the epidermis of transgenic mice elicits striking epidermal and hair follicle abnormalities.

    PubMed

    Troy, Tammy-Claire; Turksen, Kursad

    2007-06-01

    Skin is one of the largest organs of the body, and is formed during development through a highly orchestrated process involving mesenchymal-epithelial interactions, cell commitment, and terminal differentiation. It protects against microorganism invasion and UV irradiation, inhibits water loss, regulates body temperature, and is an important part of the immune system. Using transgenic mouse technology, we have demonstrated that Claudin (Cldn)-containing tight junctions (TJs) are intricately involved in cell signaling during epidermal differentiation and that an epidermal suprabasal overexpression of Cldn6 results in a perturbed epidermal terminal differentiation program with distinct phenotypic abnormalities. To delineate the role of the Cldn cytoplasmic tail domain in epidermal differentiation, we engineered transgenic mice targeting the overexpression of a Cldn6 cytoplasmic tail-truncation mutant in the epidermis. Transgenic mice were characterized by a lethal barrier dysfunction in addition to the existence of hyperproliferative squamous invaginations/cysts replacing hair follicles. Immunohistochemical analysis revealed an epidermal cytoplasmic accumulation of Cldn6, Cldn11, Cldn12, and Cldn18, downregulation of Cldn1 and aberrant expression of various classical markers of epidermal differentiation; namely the basal keratins as well as K1, involucrin, loricrin, and filaggrin. Collectively these studies suggest an important role for Cldns in epidermal/hair follicle differentiation programs likely involving cross talk to signaling pathways (e.g., Notch) directing cell fate selection and differentiation.

  11. Protective Immunity Elicited by Oral Immunization of Mice with Salmonella enterica Serovar Typhimurium Braun Lipoprotein (Lpp) and Acetyltransferase (MsbB) Mutants

    PubMed Central

    Erova, Tatiana E.; Kirtley, Michelle L.; Fitts, Eric C.; Ponnusamy, Duraisamy; Baze, Wallace B.; Andersson, Jourdan A.; Cong, Yingzi; Tiner, Bethany L.; Sha, Jian; Chopra, Ashok K.

    2016-01-01

    We evaluated the extent of attenuation and immunogenicity of the ΔlppAB and ΔlppAB ΔmsbB mutants of Salmonella enterica serovar Typhimurium when delivered to mice by the oral route. These mutants were deleted either for the Braun lipoprotein genes (lppA and lppB) or in combination with the msbB gene, which encodes an acetyltransferase required for lipid A modification of lipopolysaccharide. Both the mutants were attenuated (100% animal survival) and triggered robust innate and adaptive immune responses. Comparable levels of IgG and its isotypes were produced in mice infected with wild-type (WT) S. typhimurium or its aforementioned mutant strains. The ΔlppAB ΔmsbB mutant-immunized animals resulted in the production of higher levels of fecal IgA and serum cytokines during later stages of vaccination (adaptive response). A significant production of interleukin-6 from T-cells was also noted in the ΔlppAB ΔmsbB mutant-immunized mice when compared to that of the ΔlppAB mutant. On the other hand, IL-17A production was significantly more in the serum of ΔlppAB mutant-immunized mice (innate response) with a stronger splenic T-cell proliferative and tumor-necrosis factor-α production. Based on 2-dimensional gel analysis, alterations in the levels of several proteins were observed in both the mutant strains when compared to that in WT S. typhimurium and could be associated with the higher immunogenicity of the mutants. Finally, both ΔlppAB and ΔlppAB ΔmsbB mutants provided complete protection to immunized mice against a lethal oral challenge dose of WT S. typhimurium. Thus, these mutants may serve as excellent vaccine candidates and also provide a platform for delivering heterologous antigens. PMID:27891321

  12. Protective Immunity Elicited by Oral Immunization of Mice with Salmonella enterica Serovar Typhimurium Braun Lipoprotein (Lpp) and Acetyltransferase (MsbB) Mutants.

    PubMed

    Erova, Tatiana E; Kirtley, Michelle L; Fitts, Eric C; Ponnusamy, Duraisamy; Baze, Wallace B; Andersson, Jourdan A; Cong, Yingzi; Tiner, Bethany L; Sha, Jian; Chopra, Ashok K

    2016-01-01

    We evaluated the extent of attenuation and immunogenicity of the ΔlppAB and ΔlppAB ΔmsbB mutants of Salmonella enterica serovar Typhimurium when delivered to mice by the oral route. These mutants were deleted either for the Braun lipoprotein genes (lppA and lppB) or in combination with the msbB gene, which encodes an acetyltransferase required for lipid A modification of lipopolysaccharide. Both the mutants were attenuated (100% animal survival) and triggered robust innate and adaptive immune responses. Comparable levels of IgG and its isotypes were produced in mice infected with wild-type (WT) S. typhimurium or its aforementioned mutant strains. The ΔlppAB ΔmsbB mutant-immunized animals resulted in the production of higher levels of fecal IgA and serum cytokines during later stages of vaccination (adaptive response). A significant production of interleukin-6 from T-cells was also noted in the ΔlppAB ΔmsbB mutant-immunized mice when compared to that of the ΔlppAB mutant. On the other hand, IL-17A production was significantly more in the serum of ΔlppAB mutant-immunized mice (innate response) with a stronger splenic T-cell proliferative and tumor-necrosis factor-α production. Based on 2-dimensional gel analysis, alterations in the levels of several proteins were observed in both the mutant strains when compared to that in WT S. typhimurium and could be associated with the higher immunogenicity of the mutants. Finally, both ΔlppAB and ΔlppAB ΔmsbB mutants provided complete protection to immunized mice against a lethal oral challenge dose of WT S. typhimurium. Thus, these mutants may serve as excellent vaccine candidates and also provide a platform for delivering heterologous antigens.

  13. Intranasal Vaccination with the Recombinant Listeria monocytogenes ΔactA prfA* Mutant Elicits Robust Systemic and Pulmonary Cellular Responses and Secretory Mucosal IgA ▿

    PubMed Central

    Qiu, Jin; Yan, Lin; Chen, Jianbo; Chen, Crystal Y.; Shen, Ling; Letvin, Norman L.; Haynes, Barton F.; Freitag, Nancy; Rong, Lijun; Frencher, James T.; Huang, Dan; Wang, Xunming; Chen, Zheng W.

    2011-01-01

    We previously showed that recombinant (r) Listeria monocytogenes carrying ΔactA and a selected prfA* mutation (r-Listeria ΔactA prfA*) secreted >100-fold more immunogen in broth culture than wild-type r-Listeria or r-Listeria ΔactA and elicited much greater cellular and humoral immune responses than r-Listeria ΔactA after intravenous vaccination of mice. Here, we conducted comparative studies evaluating vaccine-elicited immune responses in systemic and mucosal sites after intranasal, intravenous, intraperitoneal, or subcutaneous immunization of mice with r-Listeria ΔactA prfA* vaccine candidates. Intranasal vaccination of mice with r-Listeria ΔactA prfA* vaccine candidates elicited a robust gamma interferon-positive (IFN-γ+) cellular response in systemic sites, although intravenous or intraperitoneal immunization was more efficient. Surprisingly, intranasal vaccination elicited an appreciable pulmonary IFN-γ+ cellular response that was nonstatistically higher than the magnitude induced by the intravenous route but was significantly greater than that elicited by subcutaneous immunization. Furthermore, although intranasal r-Listeria ΔactA prfA* delivery induced poor systemic IgG responses, intranasal vaccination elicited appreciable secretory immunogen-specific IgA titers that were similar to or higher in mucosal fluid than those induced by subcutaneous and intravenous immunizations. Thus, intranasal vaccination with r-Listeria ΔactA prfA* appears to be a useful approach for eliciting robust systemic and pulmonary cellular responses and measurable secretory mucosal IgA titers. PMID:21270282

  14. Rational elicitation of cold-sensitive phenotypes

    PubMed Central

    Baliga, Chetana; Majhi, Sandipan; Mondal, Kajari; Bhattacharjee, Antara; Varadarajan, Raghavan

    2016-01-01

    Cold-sensitive phenotypes have helped us understand macromolecular assembly and biological phenomena, yet few attempts have been made to understand the basis of cold sensitivity or to elicit it by design. We report a method for rational design of cold-sensitive phenotypes. The method involves generation of partial loss-of-function mutants, at either buried or functional sites, coupled with selective overexpression strategies. The only essential input is amino acid sequence, although available structural information can be used as well. The method has been used to elicit cold-sensitive mutants of a variety of proteins, both monomeric and dimeric, and in multiple organisms, namely Escherichia coli, Saccharomyces cerevisiae, and Drosophila melanogaster. This simple, yet effective technique of inducing cold sensitivity eliminates the need for complex mutations and provides a plausible molecular mechanism for eliciting cold-sensitive phenotypes. PMID:27091994

  15. Ludic Elicitation: Using Games for Knowledge Elicitation

    ERIC Educational Resources Information Center

    Cao, Yan

    2014-01-01

    Knowledge elicitation from human beings is important for many fields, such as decision support systems, risk communication, and customer preference studying. Traditional approaches include observations, questionnaires, structured and semi-structured interviews, and group discussions. Many publications have been studying different techniques for a…

  16. Ludic Elicitation: Using Games for Knowledge Elicitation

    ERIC Educational Resources Information Center

    Cao, Yan

    2014-01-01

    Knowledge elicitation from human beings is important for many fields, such as decision support systems, risk communication, and customer preference studying. Traditional approaches include observations, questionnaires, structured and semi-structured interviews, and group discussions. Many publications have been studying different techniques for a…

  17. PDGFRA-mutant syndrome.

    PubMed

    Ricci, Riccardo; Martini, Maurizio; Cenci, Tonia; Carbone, Arnaldo; Lanza, Paola; Biondi, Alberto; Rindi, Guido; Cassano, Alessandra; Larghi, Alberto; Persiani, Roberto; Larocca, Luigi M

    2015-07-01

    Germline PDGFRA mutations cause multiple heterogeneous gastrointestinal mesenchymal tumors. In its familial form this disease, which was formerly termed intestinal neurofibromatosis/neurofibromatosis 3b (INF/NF3b), has been included among familial gastrointestinal stromal tumors (GISTs) because of its genotype, described when GIST was the only known PDGFRA-mutant gastrointestinal tumor. Shortly afterwards, however, inflammatory fibroid polyps also revealed PDGFRA mutations. Subsequently, gastrointestinal CD34+ 'fibrous tumors' of uncertain classification were described in a germline PDGFRA-mutant context. Our aim was to characterize the syndrome produced by germline PDGFRA mutations and establish diagnostic criteria and management strategies for this hitherto puzzling disease. We studied a kindred displaying multiple gastrointestinal mesenchymal tumors, comparing it with published families/individuals with possible analogous conditions. We identified a novel inherited PDGFRA mutation (P653L), constituting the third reported example of familial PDGFRA mutation. In adult mutants we detected inflammatory fibroid polyps, gastric GISTs and gastrointestinal fibrous tumors of uncertain nosology. We demonstrate that the syndrome formerly defined as INF/NF3b (exemplified by the family reported herein) is simplistically considered a form of familial GIST, because inflammatory fibroid polyps often prevail. Fibrous tumors appear variants of inflammatory fibroid polyps. 'INF/NF3b' and 'familial GIST' are misleading terms which we propose changing to 'PDGFRA-mutant syndrome'. In this condition, unlike KIT-dependent familial GIST syndromes, if present, GISTs are stomach-restricted and diffuse Cajal cell hyperplasia is not observed. This restriction of GISTs to the stomach in PDGFRA-mutant syndrome: (i) focuses oncological concern on gastric masses, as inflammatory fibroid polyps are benign; (ii) supports a selective role of gastric environment for PDGFRA mutations to elicit GISTs

  18. Eliciting Sound Memories.

    PubMed

    Harris, Anna

    2015-11-01

    Sensory experiences are often considered triggers of memory, most famously a little French cake dipped in lime blossom tea. Sense memory can also be evoked in public history research through techniques of elicitation. In this article I reflect on different social science methods for eliciting sound memories such as the use of sonic prompts, emplaced interviewing, and sound walks. I include examples from my research on medical listening. The article considers the relevance of this work for the conduct of oral histories, arguing that such methods "break the frame," allowing room for collaborative research connections and insights into the otherwise unarticulatable.

  19. Issues in Requirements Elicitation

    DTIC Science & Technology

    1992-09-01

    systems approach: characterized by Checkland’s Soft Systems Methodology (SSM), which is discussed briefly in Appendix A.6; emphasizes the subjectivity of...methodology for requirements elicitation. A.6 Notes on SSM Both the definition of methodology and the philosophy behind soft systems methodology (SSM...1986. [Checkland 89a] Checkland, Peter. Soft Systems Methodology . Rational Analysis for a Problematic World. New York: John Wiley & Sons, 71-100

  20. Opinion Elicitation in Second Life

    NASA Astrophysics Data System (ADS)

    van Vliet, Marijn; Neviarouskaya, Alena; Prendinger, Helmut

    The paper describes a novel method for opinion elicitation, which is based on the popular 3D online world of “Second Life”. Here people, as avatars, are put into a somewhat realistic context related to the topic for which opinions are sought. We hypothesize that this kind of concrete, interactive context supports the evocation of opinions better than non-context methods, e.g. only showing related images. To confirm our hypothesis, we conducted a small pilot study, which compares the influence of static and interactive context methods on the opinions expressed by subjects. The opinion elicitation scenario in Second Life is supported by the automatic retrieval of opinions from the web. The results of a study indicate that subjects show more reasoned opinions in the interactive condition. A demo illustrating the content of this paper is available.

  1. Requirements Elicitation Using Paper Prototype

    NASA Astrophysics Data System (ADS)

    Vijayan, Jaya; Raju, G.

    Requirements engineering is both the hardest and critical part of software development since errors at this beginning stage propagate through the development process and are the hardest to repair later. This paper proposes an improved approach for requirements elicitation using paper prototype. The paper progresses through an assessment of the new approach using student projects developed for various organizations. The scope of implementation of paper prototype and its advantages are unveiled.

  2. Saccharomyces cerevisiae aldolase mutants.

    PubMed Central

    Lobo, Z

    1984-01-01

    Six mutants lacking the glycolytic enzyme fructose 1,6-bisphosphate aldolase have been isolated in the yeast Saccharomyces cerevisiae by inositol starvation. The mutants grown on gluconeogenic substrates, such as glycerol or alcohol, and show growth inhibition by glucose and related sugars. The mutations are recessive, segregate as one gene in crosses, and fall in a single complementation group. All of the mutants synthesize an antigen cross-reacting to the antibody raised against yeast aldolase. The aldolase activity in various mutant alleles measured as fructose 1,6-bisphosphate cleavage is between 1 to 2% and as condensation of triose phosphates to fructose 1,6-bisphosphate is 2 to 5% that of the wild-type. The mutants accumulate fructose 1,6-bisphosphate from glucose during glycolysis and dihydroxyacetone phosphate during gluconeogenesis. This suggests that the aldolase activity is absent in vivo. PMID:6384192

  3. Rhizobacterial exopolysaccharides elicit induced resistance on cucumber.

    PubMed

    Park, Kyungseok; Kloepper, Joseph W; Ryu, Choong-Min

    2008-06-01

    The role of exopolysaccharides (EPSs) from a plant growth-promoting rhizobacterium, Burkholderia gladioli IN26, on elicitation of induced systemic resistance was investigated. A purified EPS induced expression of PR- 1a::GUS on tobacco and elicited induced resistance against Colletotrichum orbiculare on cucumber. The maximum level of disease protection was noted when seeds were soaked in 200 ppm of the EPS. Our results indicate that EPS from specific rhizobacteria can elicit induced resistance and suggest that bacterial EPS might be a useful elicitor of resistance under field conditions.

  4. Nicotine elicits prolonged calcium signaling along ventral hippocampal axons.

    PubMed

    Zhong, Chongbo; Talmage, David A; Role, Lorna W

    2013-01-01

    Presynaptic nicotinic acetylcholine receptors (nAChRs) have long been implicated in the modulation of CNS circuits. We previously reported that brief exposure to low concentrations of nicotine induced sustained potentiation of glutamatergic transmission at ventral hippocampal (vHipp)-striatal synapses. Here, we exploited nAChR subtype-selective antagonists and agonists and α7*nAChR knockout mutant mice (α7-/-) to elucidate the signaling mechanisms underlying nAChR-mediated modulation of synaptic transmission. Using a combination of micro-slices culture from WT and α7-/-mice, calcium imaging, and immuno-histochemical techniques, we found that nicotine elicits localized and oscillatory increases in intracellular Ca(2+) along vHipp axons that persists for up to 30 minutes. The sustained phase of the nicotine-induced Ca(2+) response was blocked by α-BgTx but not by DHβE and was mimicked by α7*nAChR agonists but not by non-α7*nAChR agonists. In vHipp slices from α7-/- mice, nicotine elicited only transient increases of axonal Ca(2+) signals and did not activate CaMKII. The sustained phase of the nicotine-induced Ca(2+) response required localized activation of CaMKII, phospholipase C, and IP3 receptor mediated Ca(2+)-induced Ca(2+) release (CICR). In conclusion, activation of presynaptic nAChRs by nicotine elicits Ca(2+) influx into the presynaptic axons, the sustained phase of the nicotine-induced Ca(2+) response requires that axonal α7*nAChR activate a downstream signaling network in the vHipp axons.

  5. Brassinosteroid Mutants of Crops.

    PubMed

    Bishop, Gerard J.

    2003-12-01

    Plant steroid hormones, brassinosteroids (BRs), were originally isolated from extracts of pollen because of their growth-promoting properties and their potential use for enhancing crop production. Mutants in the biosynthesis, metabolism, and signaling of brassinolide (BL), the most bioactive BR, are important resources in helping to establish BRs' essential role in plant growth and development. The dark green and distinctive dwarf phenotype of BR-related mutants identified in pea, tomato, and rice highlights the importance of BRs in crops. These mutants are helping to elucidate both the conserved and the unique features of BR biosynthesis and signaling. Such insights are providing the key knowledge and understanding that will enable the development of strategies towards the production of crops with enhanced qualities.

  6. A Knowledge Elicitation Study of Military Planning

    DTIC Science & Technology

    1990-02-01

    66027-0347 Ba. NAME OF FUNDING/SPONSORING 8b. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORPANIZATION U.S. Army Research (If...Method (CDM) has been developed as a knowledge elicitation tool for probing proficient decision making. This report describes the use of CDM during...knowledge elicitation can be used in Army Command and Control (Ce) exercises as a means of understanding decision-making dynamics. Such a tool could

  7. Mutant fatty acid desaturase

    DOEpatents

    Shanklin, John; Cahoon, Edgar B.

    2004-02-03

    The present invention relates to a method for producing mutants of a fatty acid desaturase having a substantially increased activity towards fatty acid substrates with chains containing fewer than 18 carbons relative to an unmutagenized precursor desaturase having an 18 carbon atom chain length substrate specificity. The method involves inducing one or more mutations in the nucleic acid sequence encoding the precursor desaturase, transforming the mutated sequence into an unsaturated fatty acid auxotroph cell such as MH13 E. coli, culturing the cells in the absence of supplemental unsaturated fatty acids, thereby selecting for recipient cells which have received and which express a mutant fatty acid desaturase with an elevated specificity for fatty acid substrates having chain lengths of less than 18 carbon atoms. A variety of mutants having 16 or fewer carbon atom chain length substrate specificities are produced by this method. Mutant desaturases produced by this method can be introduced via expression vectors into prokaryotic and eukaryotic cells and can also be used in the production of transgenic plants which may be used to produce specific fatty acid products.

  8. Attenuated temperature-sensitive respiratory syncytial virus mutants generated by cold adaptation.

    PubMed

    Randolph, V B; Kandis, M; Stemler-Higgins, P; Kennelly, M S; McMullen, Y M; Speelman, D J; Weeks-Levy, C

    1994-09-01

    Two strains of respiratory syncytial virus (RSV), RSV 2B and RSV 3A (representing subgroup B and A virus respectively) were cold-adapted by passaging in Vero cells for up to 42 weeks at successively lower temperatures down to 20 degrees C. Successful cold adaptation of the virus population was dependent on the amount of time the cultures were maintained at the various low temperatures, as well as on the strain of virus used. Temperature-sensitive (TS) mutants appeared in the cold passaged virus populations; however, the majority of the virus variants remained predominantly non-TS. Four RSV 2B and three RSV 3A TS mutants were selected for further characterization. These seven TS mutants retained their fusion phenotype and two major neutralizing antibody epitopes, and displayed varying levels of temperature sensitivity. Six of the seven mutants had a cold-adapted (CA) phenotype. All of the RSV 2B mutants were highly attenuated in cotton rats and two of the mutants elicited relatively high levels of neutralizing antibody and were able to protect rats against virus challenge. The RSV 3A TS mutants grew well in the nose but poorly in the cotton rat lungs, as did the parental 3A virus. All 3A mutants elicited high titers of neutralizing antibody and provided complete protection against virus challenge. These mutants showed varying levels of temperature sensitivity in vitro and attenuation in vivo and represent potential vaccine candidates.

  9. Characterization of Helicobacter pylori urease mutants.

    PubMed Central

    Segal, E D; Shon, J; Tompkins, L S

    1992-01-01

    The association between Helicobacter pylori, gastritis, and peptic ulcer is well established, and the association of infection with gastric cancer has been noted in several developing countries. However, the pathogenic mechanism(s) leading to disease states has not been elucidated. The H. pylori urease is thought to be a determinant of pathogenicity, since the enzyme is produced by all H. pylori clinical isolates. Evidence indicates that some H. pylori strains are more cytotoxic than others, with a correlation between the activity of the urease and the presence of a vacuolating cytotoxin having been made. However, the number of cytotoxins remains unknown at this time. The relationship between the urease and cytotoxicity has previously been examined with chemical inhibitors. To examine the role of the urease and its relationship to cytotoxicity, urease-deficient mutants were produced following ethyl methanesulfonate mutagenesis of H. pylori 87A300. Two mutants (the ure1 and ure5 mutants) which were entirely deficient in urease activity (Ure-) were selected. Characterization of the isolates at the protein level showed that the urease subunits lacked the ability to complex and form the active urease enzyme. The ure1 mutant was shown to be sensitive to the effects of low pH in vitro and exhibited no cytotoxicity to eucaryotic cells, whereas the parental strain (Ure+) produced a cytotoxic effect in the presence of urea. Interaction between the H. pylori Ure+ and Ure- strains and Caco-2 cells appeared to be similar in that both bacterial types elicited pedestal formation and actin condensation. These results indicate that the H. pylori urease may have many functions, among them (i) protecting H. pylori against the acidic environment of the stomach, (ii) acting as a cytotoxin, with human gastric cells especially susceptible to its activity, and (iii) disrupting cell tight junctions in such a manner that the cells remain viable but an ionic flow between the cells occurs

  10. Stereoscopy Amplifies Emotions Elicited by Facial Expressions

    PubMed Central

    Kätsyri, Jari; Häkkinen, Jukka

    2015-01-01

    Mediated facial expressions do not elicit emotions as strongly as real-life facial expressions, possibly due to the low fidelity of pictorial presentations in typical mediation technologies. In the present study, we investigated the extent to which stereoscopy amplifies emotions elicited by images of neutral, angry, and happy facial expressions. The emotional self-reports of positive and negative valence (which were evaluated separately) and arousal of 40 participants were recorded. The magnitude of perceived depth in the stereoscopic images was manipulated by varying the camera base at 15, 40, 65, 90, and 115 mm. The analyses controlled for participants’ gender, gender match, emotional empathy, and trait alexithymia. The results indicated that stereoscopy significantly amplified the negative valence and arousal elicited by angry expressions at the most natural (65 mm) camera base, whereas stereoscopy amplified the positive valence elicited by happy expressions in both the narrowed and most natural (15–65 mm) base conditions. Overall, the results indicate that stereoscopy amplifies the emotions elicited by mediated emotional facial expressions when the depth geometry is close to natural. The findings highlight the sensitivity of the visual system to depth and its effect on emotions. PMID:27551358

  11. Stereoscopy Amplifies Emotions Elicited by Facial Expressions.

    PubMed

    Hakala, Jussi; Kätsyri, Jari; Häkkinen, Jukka

    2015-12-01

    Mediated facial expressions do not elicit emotions as strongly as real-life facial expressions, possibly due to the low fidelity of pictorial presentations in typical mediation technologies. In the present study, we investigated the extent to which stereoscopy amplifies emotions elicited by images of neutral, angry, and happy facial expressions. The emotional self-reports of positive and negative valence (which were evaluated separately) and arousal of 40 participants were recorded. The magnitude of perceived depth in the stereoscopic images was manipulated by varying the camera base at 15, 40, 65, 90, and 115 mm. The analyses controlled for participants' gender, gender match, emotional empathy, and trait alexithymia. The results indicated that stereoscopy significantly amplified the negative valence and arousal elicited by angry expressions at the most natural (65 mm) camera base, whereas stereoscopy amplified the positive valence elicited by happy expressions in both the narrowed and most natural (15-65 mm) base conditions. Overall, the results indicate that stereoscopy amplifies the emotions elicited by mediated emotional facial expressions when the depth geometry is close to natural. The findings highlight the sensitivity of the visual system to depth and its effect on emotions.

  12. Films for eliciting emotional states in children.

    PubMed

    von Leupoldt, Andreas; Rohde, Jenny; Beregova, Anna; Thordsen-Sörensen, Imke; zur Nieden, Janine; Dahme, Bernhard

    2007-08-01

    Standardized sets of films have been shown to be effective for eliciting emotional states in adults, but no comparable validated stimuli are available for children. We therefore examined the effects of three pre-selected film clips each of 3-min duration in eliciting a pleasant, neutral and unpleasant emotional state in 297 children aged between 6 and 12 years. After the films were presented on a video projector, affective ratings were obtained with the Self-Assessment-Manikin on the emotional dimensions of valence and arousal. Increasing pleasure ratings were observed from the unpleasant to the neutral to the pleasant film. Associated arousal ratings were stronger for the unpleasant and pleasant films compared to the neutral film. Overall, results showed successful elicitation of targeted emotional states only marginally influenced by age, gender or prior experience with the films. The use of these films is therefore suggested for future studies on emotions in children.

  13. Superior protection elicited by live-attenuated vaccines in the murine model of paratuberculosis.

    PubMed

    Ghosh, Pallab; Shippy, Daniel C; Talaat, Adel M

    2015-12-16

    Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) causes Johne's disease, a chronic enteric infection in ruminants with severe economic impact on the dairy industry in the USA and worldwide. Currently, available vaccines have limited protective efficacy against disease progression and does not prevent spread of the infection among animals. Because of their ability to elicit wide-spectrum immune responses, we adopted a live-attenuated vaccine approach based on a sigH knock-out strain of M. paratuberculosis (ΔsigH). Earlier analysis of the ΔsigH mutant in mice indicated their inadequate ability to colonize host tissues, unlike the isogenic wild-type strain, validating the role of this sigma factor in M. paratuberculosis virulence. In the present study, we evaluated the performance of the ΔsigH mutant compared to inactivated vaccine constructs in a vaccine/challenge model of murine paratuberculosis. The presented analysis indicated that ΔsigH mutant with or without QuilA adjuvant is capable of eliciting strong immune responses (such as interferon gamma-γ, IFN-γ) suggesting their immunogenicity and ability to potentially initiate effective vaccine-induced immunity. Following a challenge with virulent strains of M. paratuberculosis, ΔsigH conferred protective immunity as indicated by the reduced bacterial burden accompanied with reduced lesions in main body organs (liver, spleen and intestine) usually infected with M. paratuberculosis. More importantly, our data indicated better ability of the ΔsigH vaccine to confer protection compared to the inactivated vaccine constructs even with the presence of oil-adjuvant. Overall, our approach provides a rational basis for using live-attenuated mutant strains to develop improved vaccines that elicit robust immunity against this chronic infection.

  14. A Mutant Library Approach to Identify Improved Meningococcal Factor H Binding Protein Vaccine Antigens

    PubMed Central

    Konar, Monica; Rossi, Raffaella; Walter, Helen; Pajon, Rolando; Beernink, Peter T.

    2015-01-01

    Factor H binding protein (FHbp) is a virulence factor used by meningococci to evade the host complement system. FHbp elicits bactericidal antibodies in humans and is part of two recently licensed vaccines. Using human complement Factor H (FH) transgenic mice, we previously showed that binding of FH decreased the protective antibody responses to FHbp vaccination. Therefore, in the present study we devised a library-based method to identify mutant FHbp antigens with very low binding of FH. Using an FHbp sequence variant in one of the two licensed vaccines, we displayed an error-prone PCR mutant FHbp library on the surface of Escherichia coli. We used fluorescence-activated cell sorting to isolate FHbp mutants with very low binding of human FH and preserved binding of control anti-FHbp monoclonal antibodies. We sequenced the gene encoding FHbp from selected clones and introduced the mutations into a soluble FHbp construct. Using this approach, we identified several new mutant FHbp vaccine antigens that had very low binding of FH as measured by ELISA and surface plasmon resonance. The new mutant FHbp antigens elicited protective antibody responses in human FH transgenic mice that were up to 20-fold higher than those elicited by the wild-type FHbp antigen. This approach offers the potential to discover mutant antigens that might not be predictable even with protein structural information and potentially can be applied to other microbial vaccine antigens that bind host proteins. PMID:26057742

  15. Realistic Real World Contexts: Model Eliciting Activities

    ERIC Educational Resources Information Center

    Doruk, Bekir Kürsat

    2016-01-01

    Researchers have proposed a variety of methods to make a connection between real life and mathematics so that it can be learned in a practical way and enable people to utilise mathematics in their daily lives. Model-eliciting activities (MEAs) were developed to fulfil this need and are very capable of serving this purpose. The reason MEAs are so…

  16. Video Elicitation of the Semiotic Self.

    ERIC Educational Resources Information Center

    Stockall, Nancy

    2001-01-01

    Illustrates the power of video recording to elicit the thinking of teachers as they reflect on their teaching practices. Draws on the work of Wiley (1994), which identified the internal conversation as a critical feature of the semiotic self. (Author/VWL)

  17. Eliciting User Requirements Using Appreciative Inquiry

    ERIC Educational Resources Information Center

    Gonzales, Carol Kernitzki

    2010-01-01

    Many software development projects fail because they do not meet the needs of users, are over-budget, and abandoned. To address this problem, the user requirements elicitation process was modified based on principles of Appreciative Inquiry. Appreciative Inquiry, commonly used in organizational development, aims to build organizations, processes,…

  18. Methods of Eliciting Information from Experts

    DTIC Science & Technology

    1987-10-01

    Itzhak Perlman) or a concertmeister in an orchestra, or simply one of its violinists . Differences in amount of expertise may supply different...would lead to becoming a world class violinist . Underlying Assumptions In attempting to elicit information from experts, one makes a number of

  19. Eliciting User Requirements Using Appreciative Inquiry

    ERIC Educational Resources Information Center

    Gonzales, Carol Kernitzki

    2010-01-01

    Many software development projects fail because they do not meet the needs of users, are over-budget, and abandoned. To address this problem, the user requirements elicitation process was modified based on principles of Appreciative Inquiry. Appreciative Inquiry, commonly used in organizational development, aims to build organizations, processes,…

  20. Realistic Real World Contexts: Model Eliciting Activities

    ERIC Educational Resources Information Center

    Doruk, Bekir Kürsat

    2016-01-01

    Researchers have proposed a variety of methods to make a connection between real life and mathematics so that it can be learned in a practical way and enable people to utilise mathematics in their daily lives. Model-eliciting activities (MEAs) were developed to fulfil this need and are very capable of serving this purpose. The reason MEAs are so…

  1. Enhanced protective antibody to a mutant meningococcal factor H-binding protein with low-factor H binding

    PubMed Central

    Granoff, Dan M.; Giuntini, Serena; Gowans, Flor A.; Lujan, Eduardo; Sharkey, Kelsey; Beernink, Peter T.

    2016-01-01

    Meningococcal factor H-binding protein (FHbp) is an antigen in 2 serogroup B meningococcal vaccines. FHbp specifically binds human and some nonhuman primate complement FH. To investigate the effect of binding of FH to FHbp on protective antibody responses, we immunized infant rhesus macaques with either a control recombinant FHbp antigen that bound macaque FH or a mutant antigen with 2 amino acid substitutions and >250-fold lower affinity for FH. The mutant antigen elicited 3-fold higher serum IgG anti-FHbp titers and up to 15-fold higher serum bactericidal titers than the control FHbp vaccine. When comparing sera with similar IgG anti-FHbp titers, the antibodies elicited by the mutant antigen gave greater deposition of complement component C4b on live meningococci (classical complement pathway) and inhibited binding of FH, while the anti-FHbp antibodies elicited by the control vaccine enhanced FH binding. Thus, the mutant FHbp vaccine elicited an anti-FHbp antibody repertoire directed at FHbp epitopes within the FH binding site, which resulted in greater protective activity than the antibodies elicited by the control vaccine, which targeted FHbp epitopes outside of the FH combining site. Binding of a host protein to a vaccine antigen impairs protective antibody responses, which can be overcome with low-binding mutant antigens. PMID:27668287

  2. The zebrafish early arrest mutants.

    PubMed

    Kane, D A; Maischein, H M; Brand, M; van Eeden, F J; Furutani-Seiki, M; Granato, M; Haffter, P; Hammerschmidt, M; Heisenberg, C P; Jiang, Y J; Kelsh, R N; Mullins, M C; Odenthal, J; Warga, R M; Nüsslein-Volhard, C

    1996-12-01

    This report describes mutants of the zebrafish having phenotypes causing a general arrest in early morphogenesis. These mutants identify a group of loci making up about 20% of the loci identified by mutants with visible morphological phenotypes within the first day of development. There are 12 Class I mutants, which fall into 5 complementation groups and have cells that lyse before morphological defects are observed. Mutants at three loci, speed bump, ogre and zombie, display abnormal nuclei. The 8 Class II mutants, which fall into 6 complementation groups, arrest development before cell lysis is observed. These mutants seemingly stop development in the late segmentation stages, and maintain a body shape similar to a 20 hour embryo. Mutations in speed bump, ogre, zombie, specter, poltergeist and troll were tested for cell lethality by transplanting mutant cells into wild-type hosts. With poltergeist, transplanted mutant cells all survive. The remainder of the mutants tested were autonomously but conditionally lethal: mutant cells, most of which lyse, sometimes survive to become notochord, muscles, or, in rare cases, large neurons, all cell types which become postmitotic in the gastrula. Some of the genes of the early arrest group may be necessary for progression though the cell cycle; if so, the survival of early differentiating cells may be based on having their terminal mitosis before the zygotic requirement for these genes.

  3. Learning from Expert Elicitation in Climate Change

    NASA Astrophysics Data System (ADS)

    Morgan, M. G.

    2009-12-01

    Since the early 1990's the author has been involved in the design and execution of six detailed expert elicitations that, among other things, have obtained subjective judgments from experts that reflect their best judgment in the form of subjective probability density functions, about the value of key climate variables, climate impacts and a technology for mitigation (Morgan and Keith, 1995; Morgan Pitelka and Shevliakova, 2001; Morgan, Adams and Keith, 2006; Zickfeld et al, 2007; Curtright, Morgan and Keith, 2008; Zickfeld, Morgan Keith and Frame, in review). This paper builds on that experience to draw insights about the design and use of expert elicitation in the assessment and analysis of climate change and its impacts. Several trends in responses will be noted. Methodological pitfalls will be discussed. Comparisons will be drawn with the consensus-based methods employed by IPCC, which appear to have produced tighter uncertainty bounds than individual elicitation. The paper will close with thoughts on the possible use of expert elicitation in future IPCC assessments. Support for this work is from the Climate Decision Making Center through a cooperative agreement between the National Science Foundation (SES-0345798) and Carnegie Mellon University. References: M. Granger Morgan and David Keith, "Subjective Judgments by Climate Experts," Environmental Science & Technology, 29(10), 468A-476A, October 1995. M. Granger Morgan, Louis F. Pitelka and Elena Shevliakova, "Elicitation of Expert Judgments of Climate Change Impacts on Forest Ecosystems," Climatic Change, 49, 279-307, 2001. M. Granger Morgan, Peter Adams, and David W. Keith, "Elicitation of Expert Judgments of Aerosol Forcing," Climatic Change, 75, 195-214, 2006. Kirsten Zickfeld, Anders Levermann, Till Kuhlbrodt. Stefan Rahmstorf, M. Granger Morgan and David Keith, "Expert Judgements on the Response on the Atlantic Meridional Overturning Circulation to Climate Change," Climatic Change, 82, 235-265, 2007

  4. Critical molecular regions for elicitation of the sweetness of the sweet-tasting protein, thaumatin I.

    PubMed

    Ohta, Keisuke; Masuda, Tetsuya; Ide, Nobuyuki; Kitabatake, Naofumi

    2008-07-01

    Thaumatin is an intensely sweet-tasting protein. To identify the critical amino acid residue(s) responsible for elicitation of the sweetness of thaumatin, we prepared mutant thaumatin proteins, using Pichia pastoris, in which alanine residues were substituted for lysine or arginine residues, and the sweetness of each mutant protein was evaluated by sensory analysis in humans. Four lysine residues (K49, K67, K106 and K163) and three arginine residues (R76, R79 and R82) played significant roles in thaumatin sweetness. Of these residues, K67 and R82 were particularly important for eliciting the sweetness. We also prepared two further mutant thaumatin I proteins: one in which an arginine residue was substituted for a lysine residue, R82K, and one in which a lysine residue was substituted for an arginine residue, K67R. The threshold value for sweetness was higher for R82K than for thaumatin I, indicating that not only the positive charge but also the structure of the side chain of the arginine residue at position 82 influences the sweetness of thaumatin, whereas only the positive charge of the K67 side chain affects sweetness.

  5. Eliciting nicotine craving with virtual smoking cues.

    PubMed

    Gamito, Pedro; Oliveira, Jorge; Baptista, André; Morais, Diogo; Lopes, Paulo; Rosa, Pedro; Santos, Nuno; Brito, Rodrigo

    2014-08-01

    Craving is a strong desire to consume that emerges in every case of substance addiction. Previous studies have shown that eliciting craving with an exposure cues protocol can be a useful option for the treatment of nicotine dependence. Thus, the main goal of this study was to develop a virtual platform in order to induce craving in smokers. Fifty-five undergraduate students were randomly assigned to two different virtual environments: high arousal contextual cues and low arousal contextual cues scenarios (17 smokers with low nicotine dependency were excluded). An eye-tracker system was used to evaluate attention toward these cues. Eye fixation on smoking-related cues differed between smokers and nonsmokers, indicating that smokers focused more often on smoking-related cues than nonsmokers. Self-reports of craving are in agreement with these results and suggest a significant increase in craving after exposure to smoking cues. In sum, these data support the use of virtual environments for eliciting craving.

  6. Elicitation of secondary metabolism in actinomycetes.

    PubMed

    Abdelmohsen, Usama Ramadan; Grkovic, Tanja; Balasubramanian, Srikkanth; Kamel, Mohamed Salah; Quinn, Ronald J; Hentschel, Ute

    2015-11-01

    Genomic sequence data have revealed the presence of a large fraction of putatively silent biosynthetic gene clusters in the genomes of actinomycetes that encode for secondary metabolites, which are not detected under standard fermentation conditions. This review focuses on the effects of biological (co-cultivation), chemical, as well as molecular elicitation on secondary metabolism in actinomycetes. Our review covers the literature until June 2014 and exemplifies the diversity of natural products that have been recovered by such approaches from the phylum Actinobacteria.

  7. Voltage transients elicited by brief chilling

    NASA Technical Reports Server (NTRS)

    Pickard, B. G.

    1984-01-01

    Chilling auxin-depleted, etiolated stems of Pisum sativum L. to 4 degrees C for 60 s enhanced the production of previously described voltage transients 20-fold. It is postulated that plasmalemmal permeability to Ca2+ is increased at low temperature, permitting influx of the ion from the apoplast to the cytosol and thereby promoting production of transients. Heating to 40 degrees C or 45 degrees C elicits no increase in transients, and heating to 50 degrees C leads to loss of turgor.

  8. ECB deacylase mutants

    DOEpatents

    Arnold, Frances H.; Shao, Zhixin; Zhao, Huimin; Giver, Lorraine J.

    2002-01-01

    A method for in vitro mutagenesis and recombination of polynucleotide sequences based on polymerase-catalyzed extension of primer oligonucleotides is disclosed. The method involves priming template polynucleotide(s) with random-sequences or defined-sequence primers to generate a pool of short DNA fragments with a low level of point mutations. The DNA fragments are subjected to denaturization followed by annealing and further enzyme-catalyzed DNA polymerization. This procedure is repeated a sufficient number of times to produce full-length genes which comprise mutants of the original template polynucleotides. These genes can be further amplified by the polymerase chain reaction and cloned into a vector for expression of the encoded proteins.

  9. Essays on probability elicitation scoring rules

    NASA Astrophysics Data System (ADS)

    Firmino, Paulo Renato A.; dos Santos Neto, Ademir B.

    2012-10-01

    In probability elicitation exercises it has been usual to considerer scoring rules (SRs) to measure the performance of experts when inferring about a given unknown, Θ, for which the true value, θ*, is (or will shortly be) known to the experimenter. Mathematically, SRs quantify the discrepancy between f(θ) (the distribution reflecting the expert's uncertainty about Θ) and d(θ), a zero-one indicator function of the observation θ*. Thus, a remarkable characteristic of SRs is to contrast expert's beliefs with the observation θ*. The present work aims at extending SRs concepts and formulas for the cases where Θ is aleatory, highlighting advantages of goodness-of-fit and entropy-like measures. Conceptually, it is argued that besides of evaluating the personal performance of the expert, SRs may also play a role when comparing the elicitation processes adopted to obtain f(θ). Mathematically, it is proposed to replace d(θ) by g(θ), the distribution that model the randomness of Θ, and do also considerer goodness-of-fit and entropylike metrics, leading to SRs that measure the adherence of f(θ) to g(θ). The implications of this alternative perspective are discussed and illustrated by means of case studies based on the simulation of controlled experiments. The usefulness of the proposed approach for evaluating the performance of experts and elicitation processes is investigated.

  10. Eliciting principles of hazard identification from experts.

    PubMed

    Jelovsek, F R; Mattison, D R; Young, J F

    1990-11-01

    National experts in the field of developmental toxicology were interviewed in order to elicit the principles, or rules-of-thumb, they use in determining if a compound or agent is likely to be a developmental hazard during pregnancy. Several levels of individual and cumulative consensus activity were carried out that resulted in consensus in 71 rules and partial consensus in an additional 24 rules of 145 rules initially elicited. Rules could be divided generically into those affecting the expert's confidence in a piece of scientific evidence and those determining the weight of importance of that evidence in deciding about hazard identification. Topically, the rules also divided into those about the general nature or characteristics of a compound, animal studies testing for an effect of the compound, and human reports about the presence of absence of developmental effects associated with the compound. Several conclusions about the methodology include the following: 1) expert systems must be based on the knowledge of more than one expert; 2) considerable human effort is expended in evaluating the certainty of scientific evidence before combining the evidence for problem solving; 3) how experts use evidence of different degrees of uncertainty in their decisions is a major area that is yet to be determined and that may greatly affect subsequent efforts in artificial intelligence; and 4) knowledge elicitation by interview has limitations but is a workable methodology for medical decision making.

  11. Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

    PubMed Central

    Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

    2009-01-01

    Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho) mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch-once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch-once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs. PMID:20161699

  12. A Rhizobium meliloti mutant that forms ineffective pseudonodules in alfalfa produces exopolysaccharide but fails to form beta-(1----2) glucan.

    PubMed Central

    Geremia, R A; Cavaignac, S; Zorreguieta, A; Toro, N; Olivares, J; Ugalde, R A

    1987-01-01

    A mutant of Rhizobium meliloti that elicited the formation of inactive nodules in alfalfa was found not to form beta-(1----2) glucan in vivo or in vitro. It was nonmotile because it lacks flagella. The 235-kilodalton protein which acts as an intermediate in beta-(1----2) glucan synthesis was undetectable in the mutant. These properties of the mutant are common to those of chvB mutants of Agrobacterium tumefaciens. Exopolysaccharide formation by the R. meliloti mutant was about double that by the wild type. Images PMID:3804979

  13. Characterization of epitopes on the rabies virus glycoprotein by selection and analysis of escape mutants.

    PubMed

    Fallahi, Firouzeh; Wandeler, Alexander I; Nadin-Davis, Susan A

    2016-07-15

    The glycoprotein (G) is the only surface protein of the lyssavirus particle and the only viral product known to be capable of eliciting the production of neutralizing antibodies. In this study, the isolation of escape mutants resistant to monoclonal antibody (Mab) neutralization was attempted by a selection strategy employing four distinct rabies virus strains: the extensively passaged Evelyn Rokitnicki Abelseth (ERA) strain and three field isolates representing two bat-associated variants and the Western Canada skunk variant (WSKV). No escape mutants were generated from either of the bat-associated viral variants but two neutralization mutants were derived from the WSKV isolate. Seven independent ERA mutants were recovered using Mabs directed against antigenic sites I (four mutants) and IIIa (three mutants) of the glycoprotein. The cross-neutralization patterns of these viral mutants were used to determine the precise location and nature of the G protein epitopes recognized by these Mabs. Nucleotide sequencing of the G gene indicated that those mutants derived using Mabs directed to antigenic site (AS) III all contained amino acid substitutions in this site. However, of the four mutants selected with AS I Mabs, two bore mutations within AS I as expected while the remaining two carried mutations in AS II. WSKV mutants exhibited mutations at the sites appropriate for the Mabs used in their selection. All ERA mutant preparations were more cytopathogenic than the parental virus when propagated in cell culture; when in vivo pathogenicity in mice was examined, three of these mutants exhibited reduced pathogenicity while the remaining four mutants exhibited comparable pathogenic properties to those of the parent virus.

  14. Unsaturated Zone Flow Model Expert Elicitation Project

    SciTech Connect

    Coppersmith, K. J.

    1997-05-30

    This report presents results of the Unsaturated Zone Flow Model Expert Elicitation (UZFMEE) project at Yucca Mountain, Nevada. This project was sponsored by the US Department of Energy (DOE) and managed by Geomatrix Consultants, Inc. (Geomatrix), for TRW Environmental Safety Systems, Inc. The objective of this project was to identify and assess the uncertainties associated with certain key components of the unsaturated zone flow system at Yucca Mountain. This assessment reviewed the data inputs, modeling approaches, and results of the unsaturated zone flow model (termed the ''UZ site-scale model'') being developed by Lawrence Berkeley National Laboratory (LBNL) and the US Geological Survey (USGS). In addition to data input and modeling issues, the assessment focused on percolation flux (volumetric flow rate per unit cross-sectional area) at the potential repository horizon. An understanding of unsaturated zone processes is critical to evaluating the performance of the potential high-level nuclear waste repository at Yucca Mountain. A major goal of the project was to capture the uncertainties involved in assessing the unsaturated flow processes, including uncertainty in both the models used to represent physical controls on unsaturated zone flow and the parameter values used in the models. To ensure that the analysis included a wide range of perspectives, multiple individual judgments were elicited from members of an expert panel. The panel members, who were experts from within and outside the Yucca Mountain project, represented a range of experience and expertise. A deliberate process was followed in facilitating interactions among the experts, in training them to express their uncertainties, and in eliciting their interpretations. The resulting assessments and probability distributions, therefore, provide a reasonable aggregate representation of the knowledge and uncertainties about key issues regarding the unsaturated zone at the Yucca Mountain site.

  15. Antagonist-Elicited Cannabis Withdrawal in Humans

    PubMed Central

    Gorelick, David A.; Goodwin, Robert S.; Schwilke, Eugene; Schwope, David M.; Darwin, William D.; Kelly, Deanna L.; McMahon, Robert P.; Liu, Fang; Ortemann-Renon, Catherine; Bonnet, Denis; Huestis, Marilyn A.

    2013-01-01

    Cannabinoid CB1 receptor antagonists have potential therapeutic benefits, but antagonist-elicited cannabis withdrawal has not been reported in humans. Ten male daily cannabis smokers received 8 days of increasingly frequent 20-mg oral Δ9-tetrahydrocannabinol (THC) dosages (40–120 mg/d) around-the-clock to standardize cannabis dependence while residing on a closed research unit. On the ninth day, double-blind placebo or 20- (suggested therapeutic dose) or 40-mg oral rimonabant, a CB1-cannabinoid receptor antagonist, was administered. Cannabis withdrawal signs and symptoms were assessed before and for 23.5 hours after rimonabant. Rimonabant, THC, and 11-hydroxy-THC plasma concentrations were quantified by mass spectrometry. The first 6 subjects received 20-mg rimonabant (1 placebo); the remaining 4 subjects received 40-mg rimonabant (1 placebo). Fourteen subjects enrolled; 10 completed before premature termination because of withdrawal of rimonabant from clinical development. Three of 5 subjects in the 20-mg group, 1 of 3 in the 40-mg group, and none of 2 in the placebo group met the prespecified withdrawal criterion of 150% increase or higher in at least 3 visual analog scales for cannabis withdrawal symptoms within 3 hours of rimonabant dosing. There were no significant associations between visual analog scale, heart rate, or blood pressure changes and peak rimonabant plasma concentration, area-under-the-rimonabant-concentration-by-time curve (0–8 hours), or peak rimonabant/THC or rimonabant/(THC + 11-hydroxy-THC) plasma concentration ratios. In summary, prespecified criteria for antagonist-elicited cannabis withdrawal were not observed at the 20- or 40-mg rimonabant doses. These data do not preclude antagonist-elicited withdrawal at higher rimonabant doses. PMID:21869692

  16. Antagonist-elicited cannabis withdrawal in humans.

    PubMed

    Gorelick, David A; Goodwin, Robert S; Schwilke, Eugene; Schwope, David M; Darwin, William D; Kelly, Deanna L; McMahon, Robert P; Liu, Fang; Ortemann-Renon, Catherine; Bonnet, Denis; Huestis, Marilyn A

    2011-10-01

    Cannabinoid CB1 receptor antagonists have potential therapeutic benefits, but antagonist-elicited cannabis withdrawal has not been reported in humans. Ten male daily cannabis smokers received 8 days of increasingly frequent 20-mg oral Δ⁹-tetrahydrocannabinol (THC) dosages (40-120 mg/d) around-the-clock to standardize cannabis dependence while residing on a closed research unit. On the ninth day, double-blind placebo or 20- (suggested therapeutic dose) or 40-mg oral rimonabant, a CB1-cannabinoid receptor antagonist, was administered. Cannabis withdrawal signs and symptoms were assessed before and for 23.5 hours after rimonabant. Rimonabant, THC, and 11-hydroxy-THC plasma concentrations were quantified by mass spectrometry. The first 6 subjects received 20-mg rimonabant (1 placebo); the remaining 4 subjects received 40-mg rimonabant (1 placebo). Fourteen subjects enrolled; 10 completed before premature termination because of withdrawal of rimonabant from clinical development. Three of 5 subjects in the 20-mg group, 1 of 3 in the 40-mg group, and none of 2 in the placebo group met the prespecified withdrawal criterion of 150% increase or higher in at least 3 visual analog scales for cannabis withdrawal symptoms within 3 hours of rimonabant dosing. There were no significant associations between visual analog scale, heart rate, or blood pressure changes and peak rimonabant plasma concentration, area-under-the-rimonabant-concentration-by-time curve (0-8 hours), or peak rimonabant/THC or rimonabant/(THC + 11-hydroxy-THC) plasma concentration ratios. In summary, prespecified criteria for antagonist-elicited cannabis withdrawal were not observed at the 20- or 40-mg rimonabant doses. These data do not preclude antagonist-elicited withdrawal at higher rimonabant doses.

  17. Eliciting promises from children reduces cheating.

    PubMed

    Heyman, Gail D; Fu, Genyue; Lin, Jianyan; Qian, Miao K; Lee, Kang

    2015-11-01

    Widespread cheating can undermine rules that are necessary for maintaining social order. Preventing cheating can be a challenge, especially with regard to children, who as a result of their limited executive function skills may have particular difficulty with resisting temptation to cheat. We examined one approach designed to help children resist this temptation: eliciting a verbal commitment to not cheat. We tested 4- to 7-year-olds (total N = 330) and found that starting at 5 years of age, a verbal commitment to not cheat led to a substantial reduction in cheating. The results suggest that verbal commitments can be used to help children overcome temptations and comply with rules.

  18. Isolated sleep paralysis elicited by sleep interruption.

    PubMed

    Takeuchi, T; Miyasita, A; Sasaki, Y; Inugami, M; Fukuda, K

    1992-06-01

    We elicited isolated sleep paralysis (ISP) from normal subjects by a nocturnal sleep interruption schedule. On four experimental nights, 16 subjects had their sleep interrupted for 60 minutes by forced awakening at the time when 40 minutes of nonrapid eye movement (NREM) sleep had elapsed from the termination of rapid eye movement (REM) sleep in the first or third sleep cycle. This schedule produced a sleep onset REM period (SOREMP) after the interruption at a high rate of 71.9%. We succeeded in eliciting six episodes of ISP in the sleep interruptions performed (9.4%). All episodes of ISP except one occurred from SOREMP, indicating a close correlation between ISP and SOREMP. We recorded verbal reports about ISP experiences and recorded the polysomnogram (PSG) during ISP. All of the subjects with ISP experienced inability to move and were simultaneously aware of lying in the laboratory. All but one reported auditory/visual hallucinations and unpleasant emotions. PSG recordings during ISP were characterized by a REM/W stage dissociated state, i.e. abundant alpha electroencephalographs and persistence of muscle atonia shown by the tonic electromyogram. Judging from the PSG recordings, ISP differs from other dissociated states such as lucid dreaming, nocturnal panic attacks and REM sleep behavior disorders. We compare some of the sleep variables between ISP and non-ISP nights. We also discuss the similarities and differences between ISP and sleep paralysis in narcolepsy.

  19. Multiple faces elicit augmented neural activity

    PubMed Central

    Puce, Aina; McNeely, Marie E.; Berrebi, Michael E.; Thompson, James C.; Hardee, Jillian; Brefczynski-Lewis, Julie

    2013-01-01

    How do our brains respond when we are being watched by a group of people?Despite the large volume of literature devoted to face processing, this question has received very little attention. Here we measured the effects on the face-sensitive N170 and other ERPs to viewing displays of one, two and three faces in two experiments. In Experiment 1, overall image brightness and contrast were adjusted to be constant, whereas in Experiment 2 local contrast and brightness of individual faces were not manipulated. A robust positive-negative-positive (P100-N170-P250) ERP complex and an additional late positive ERP, the P400, were elicited to all stimulus types. As the number of faces in the display increased, N170 amplitude increased for both stimulus sets, and latency increased in Experiment 2. P100 latency and P250 amplitude were affected by changes in overall brightness and contrast, but not by the number of faces in the display per se. In Experiment 1 when overall brightness and contrast were adjusted to be constant, later ERP (P250 and P400) latencies showed differences as a function of hemisphere. Hence, our data indicate that N170 increases its magnitude when multiple faces are seen, apparently impervious to basic low-level stimulus features including stimulus size. Outstanding questions remain regarding category-sensitive neural activity that is elicited to viewing multiple items of stimulus categories other than faces. PMID:23785327

  20. Assessing pragmatic skills in elicited production.

    PubMed

    de Villiers, Peter

    2004-02-01

    In developing a test of pragmatic skills for children ages 4 to 9 years, we focused on a number of functional language skills that are important for children's success in early schooling and for the development of fluent reading and writing. They included (1) wh-question asking, (2) communicative role taking, (3) linking events in a cohesive narrative, and (4) articulating the mental states of the characters in a story. All of the proposed items provide specific referential support and pragmatic motivation for the forms and content to be produced by the child. The pictured materials and elicitation prompts constrain the range of appropriate utterances, so the children's productions are more easily scored than an open-ended spontaneous speech sample. All tasks described show a clear developmental trend, a clear separation between the performance of typically developing and language-impaired children, and no performance differences between African American English- and Mainstream American English-speaking children.

  1. Reinforcing concomitants of electrically elicited vocalizations.

    PubMed

    Jürgens, U

    1976-09-24

    In 38 squirrel monkeys 251 vocalization-producing electrode positions were tested for their positive and negative reinforcing properties. Two groups of vocalization-producing brain areas could be distinguished: One group in which the electrically elicited vocalization was independent of the accompanying reinforcement effect, and a second group in which vocalization and reinforcement effect were correlated. The first group included the anterior cingulate gyrus, the adjacent supplementary motor area, gyrus rectus, ventromedial edge of the capsula interna, caudal periaqueductal gray and adjacent parabrachial region. The second group consited of the caudatum, septum, substantia innominata, amygdala, inferior thalamic peduncle, stria terminalis, midline thalamus, ventral and periventricular hypothalamus, substantia nigra, rostral periaqueductal gray, dorsolateral midbrain tegmentum and lateral medulla. It is hypothesized that the first group contains predominantly or exclusively "primary" vocalization substrates; the second group is thought to be composed mainly of structures whose stimulation yields vocalization secondarily due to stimulus induced motivational changes.

  2. Bayesian markets to elicit private information

    PubMed Central

    2017-01-01

    Financial markets reveal what investors think about the future, and prediction markets are used to forecast election results. Could markets also encourage people to reveal private information, such as subjective judgments (e.g., “Are you satisfied with your life?”) or unverifiable facts? This paper shows how to design such markets, called Bayesian markets. People trade an asset whose value represents the proportion of affirmative answers to a question. Their trading position then reveals their own answer to the question. The results of this paper are based on a Bayesian setup in which people use their private information (their “type”) as a signal. Hence, beliefs about others’ types are correlated with one’s own type. Bayesian markets transform this correlation into a mechanism that rewards truth telling. These markets avoid two complications of alternative methods: they need no knowledge of prior information and no elicitation of metabeliefs regarding others’ signals. PMID:28696293

  3. Cellular requirements for cutaneous sensitivity elicitation.

    PubMed

    Aoki, I

    1985-01-01

    The role of glass-adherent cells in cutaneous sensitivity (CS) elicitation has been analyzed in this study. CS responses have been revealed to be mediated by at least two distinct subsets of genetically restricted T cells: I-restricted 'DTH-like' T cells and K/D-restricted 'CTL-like' T cells. Both T-cell responses require I-A-positive glass-adherent cell populations, which lack T-cell markers, to manifest their activities. The role of the adherent cells is different in the 'DTH-like' responses and the 'CTL-like' responses. The disparities between the present results and previous contentions are discussed in this paper.

  4. Tetrahymena mutants with short telomeres.

    PubMed Central

    Ahmed, S; Sheng, H; Niu, L; Henderson, E

    1998-01-01

    Telomere length is dynamic in many organisms. Genetic screens that identify mutants with altered telomere lengths are essential if we are to understand how telomere length is regulated in vivo. In Tetrahymena thermophila, telomeres become long at 30 degrees, and growth rate slows. A slow-growing culture with long telomeres is often overgrown by a variant cell type with short telomeres and a rapid-doubling rate. Here we show that this variant cell type with short telomeres is in fact a mutant with a genetic defect in telomere length regulation. One of these telomere growth inhibited forever (tgi) mutants was heterozygous for a telomerase RNA mutation, and this mutant telomerase RNA caused telomere shortening when overexpressed in wild-type cells. Several other tgi mutants were also likely to be heterozygous at their mutant loci, since they reverted to wild type when selective pressure for short telomeres was removed. These results illustrate that telomere length can regulate growth rate in Tetrahymena and that this phenomenon can be exploited to identify genes involved in telomere length regulation. PMID:9755196

  5. Vaccination with an Attenuated Ferritin Mutant Protects Mice against Virulent Mycobacterium tuberculosis.

    PubMed

    Subbian, Selvakumar; Pandey, Ruchi; Soteropoulos, Patricia; Rodriguez, G Marcela

    2015-01-01

    Mycobacterium tuberculosis the causative agent of tuberculosis affects millions of people worldwide. New tools for treatment and prevention of tuberculosis are urgently needed. We previously showed that a ferritin (bfrB) mutant of M. tuberculosis has altered iron homeostasis and increased sensitivity to antibiotics and to microbicidal effectors produced by activated macrophages. Most importantly, M. tuberculosis lacking BfrB is strongly attenuated in mice, especially, during the chronic phase of infection. In this study, we examined whether immunization with a bfrB mutant could confer protection against subsequent infection with virulent M. tuberculosis in a mouse model. The results show that the protection elicited by immunization with the bfrB mutant is comparable to BCG vaccination with respect to reduction of bacterial burden. However, significant distinctions in the disease pathology and host genome-wide lung transcriptome suggest improved containment of Mtb infection in animals vaccinated with the bfrB mutant, compared to BCG. We found that downmodulation of inflammatory response and enhanced fibrosis, compared to BCG vaccination, is associated with the protective response elicited by the bfrB mutant.

  6. Expert Elicitation of Population-Level Effects of Disturbance.

    PubMed

    Fleishman, Erica; Burgman, Mark; Runge, Michael C; Schick, Robert S; Kraus, Scott

    2016-01-01

    Expert elicitation is a rigorous method for synthesizing expert knowledge to inform decision making and is reliable and practical when field data are limited. We evaluated the feasibility of applying expert elicitation to estimate population-level effects of disturbance on marine mammals. Diverse experts estimated parameters related to mortality and sublethal injury of North Atlantic right whales (Eubalaena glacialis). We are now eliciting expert knowledge on the movement of right whales among geographic regions to parameterize a spatial model of health. Expert elicitation complements methods such as simulation models or extrapolations from other species, sometimes with greater accuracy and less uncertainty.

  7. Web-based tool for expert elicitation of the variogram

    NASA Astrophysics Data System (ADS)

    Truong, Phuong N.; Heuvelink, Gerard B. M.; Gosling, John Paul

    2013-02-01

    The variogram is the keystone of geostatistics. Estimation of the variogram is deficient and difficult when there are no or too few observations available due to budget constraints or physical and temporal obstacles. In such cases, expert knowledge can be an important source of information. Expert knowledge can also fulfil the increasing demand for an a priori variogram in Bayesian geostatistics and spatial sampling optimization. Formal expert elicitation provides a sound scientific basis to reliably and consistently extract knowledge from experts. In this study, we aimed at applying existing statistical expert elicitation techniques to extract the variogram of a regionalized variable that is assumed to have either a multivariate normal or lognormal spatial probability distribution from expert knowledge. To achieve this, we developed an elicitation protocol and implemented it as a web-based tool to facilitate the elicitation of beliefs from multiple experts. Our protocol has two main rounds: elicitation of the marginal probability distribution and elicitation of the variogram. The web-based tool has three main components: a web interface for expert elicitation and feedback; a component for statistical computation and mathematical pooling of multiple experts' knowledge; and a database management component. Results from a test case study show that the protocol is adequate and that the online elicitation tool functions satisfactorily. The web-based tool is free to use and supports scientists to conveniently elicit the variogram of spatial random variables from experts. The source code is available from the journal FTP site under the GNU General Public License.

  8. Expert elicitation of population-level effects of disturbance

    USGS Publications Warehouse

    Fleishman, Erica; Burgman, Mark; Runge, Michael C.; Schick, Robert S; Krauss, Scott; Popper, Arthur N.; Hawkins, Anthony

    2016-01-01

    Expert elicitation is a rigorous method for synthesizing expert knowledge to inform decision making and is reliable and practical when field data are limited. We evaluated the feasibility of applying expert elicitation to estimate population-level effects of disturbance on marine mammals. Diverse experts estimated parameters related to mortality and sublethal injury of North Atlantic right whales (Eubalaena glacialis). We are now eliciting expert knowledge on the movement of right whales among geographic regions to parameterize a spatial model of health. Expert elicitation complements methods such as simulation models or extrapolations from other species, sometimes with greater accuracy and less uncertainty.

  9. Basic emotions elicited by odors and pictures.

    PubMed

    Croy, Ilona; Olgun, Selda; Joraschky, Peter

    2011-12-01

    The sense of olfaction is often reported to have a special relationship with emotional processing. Memories triggered by olfactory cues often have a very emotional load. On the other hand, basic negative or positive emotional states should be sufficient to cover the most significant functions of the olfactory system including ingestion, hazard avoidance, and social communication. Thus, we investigated whether different basic emotions can be evoked in healthy people through the sense of olfaction. We asked 119 participants which odor evokes one of the six basic emotions (happiness, disgust, anger, anxiety, sadness, and surprise); another 97 participants were asked about pictures evoking those emotions. The results showed that almost every participant could name an olfactory elicitor for happiness or disgust. Olfactory elicitors of anxiety were reported less frequently, but they were still reported by three-quarters of the participants. However, for sadness and anger only about half of the participants reported an olfactory elicitor, whereas significantly more named a visual cue. Olfactory emotion elicitors were mainly related to the classes of culture, plants, and food, and visual emotion elicitors were largely related to humans. This data supports the hypothesis that in the vast majority of people, few differentiated emotions can be elicited through the olfactory channel. These emotions are happiness, disgust, and anxiety. (c) 2011 APA, all rights reserved.

  10. Eliciting and using expert knowledge in metrology

    NASA Astrophysics Data System (ADS)

    O'Hagan, Anthony

    2014-08-01

    The expression of uncertainty has hitherto been seen as an add-on—first an estimate is obtained and then uncertainty in that estimate is evaluated. We argue that quantification of uncertainty should be an intrinsic part of measurement and that the measurement result should be a probability distribution for the measurand. Full quantification of uncertainties in measurement, recognizing and quantifying all sources of uncertainty, is rarely simple. Many potential sources of uncertainty can effectively only be quantified by the application of expert judgement. Scepticism about the validity or reliability of expert judgement has meant that these sources of uncertainty have often been overlooked, ignored or treated in a qualitative, narrative way. But the consequence of this is that reported expressions of uncertainty regularly understate the true degree of uncertainty in measurements. This article first discusses the concept of quantifying uncertainty in measurement, and then considers some of the areas where expert judgement is needed in order to quantify fully the uncertainties in measurement. The remainder of the article is devoted to describing methodology for eliciting expert knowledge.

  11. Acting green elicits a literal warm glow

    NASA Astrophysics Data System (ADS)

    Taufik, Danny; Bolderdijk, Jan Willem; Steg, Linda

    2015-01-01

    Environmental policies are often based on the assumption that people only act environmentally friendly if some extrinsic reward is implicated, usually money. We argue that people might also be motivated by intrinsic rewards: doing the right thing (such as acting environmentally friendly) elicits psychological rewards in the form of positive feelings, a phenomenon known as warm glow. Given the fact that people's psychological state may affect their thermal state, we expected that this warm glow could express itself quite literally: people who act environmentally friendly may perceive the temperature to be higher. In two studies, we found that people who learned they acted environmentally friendly perceived a higher temperature than people who learned they acted environmentally unfriendly. The underlying psychological mechanism pertains to the self-concept: learning you acted environmentally friendly signals to yourself that you are a good person. Together, our studies show that acting environmentally friendly can be psychologically rewarding, suggesting that appealing to intrinsic rewards can be an alternative way to encourage pro-environmental actions.

  12. DEVELOPMENT OF AN INSTRUMENT FOR ELICITING AND EVALUATING VOCATIONAL IMAGERY.

    ERIC Educational Resources Information Center

    MATHEWSON, ROBERT H.; ORTON, JOHN W.

    THIS STUDY WAS CONDUCTED TO (1) PRODUCE AN INSTRUMENT FOR ELICITING VOCATIONAL IMAGERY FOR USE IN THE EDUCATIONAL-VOCATIONAL ORIENTATION AND COUNSELING OF HIGH SCHOOL YOUTH, AND (2) DEVELOP A SCALE FOR EVALUATING THE MATURITY OF THE VOCATIONAL IMAGERY ELICITED BY THE INSTRUMENT. A PREVIOUSLY DESIGNED INSTRUMENT "WHAT I THINK OF MYSELF"…

  13. Eliciting Spontaneous Speech in Bilingual Students: Methods & Techniques.

    ERIC Educational Resources Information Center

    Cornejo, Ricardo J.; And Others

    Intended to provide practical information pertaining to methods and techniques for speech elicitation and production, the monograph offers specific methods and techniques to elicit spontaneous speech in bilingual students. Chapter 1, "Traditional Methodologies for Language Production and Recording," presents an overview of studies using…

  14. Elicited Emotions and Cognitive Functioning in Preschool Children

    ERIC Educational Resources Information Center

    Blau, Rivka; Klein, Pnina S.

    2010-01-01

    In this study, the effects of eliciting positive and negative emotions on various cognitive functions of four- to five-year-old preschool children were examined. Emotions were elicited through presentations of "happy" and "sad" video clips, before the children performed the cognitive tasks. Behavioural (facial expressions) and…

  15. Pedagogical use of ELICIT for Leadership Training: Survey and Recommendations

    DTIC Science & Technology

    2011-06-01

    classroom training as part of leadership development programs. ELICIT is particularly helpful in teaching the strengths and weakness of various...organizational structures (edge organization vs. traditional command and control hierarchy.) This paper reviews some of the pedagogical uses of the classroom ...training to date, and provides recommendations for the use of ELICIT in various classroom settings. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF

  16. Freeze or Flee? Negative Stimuli Elicit Selective Responding

    ERIC Educational Resources Information Center

    Estes, Zachary; Verges, Michelle

    2008-01-01

    Humans preferentially attend to negative stimuli. A consequence of this automatic vigilance for negative valence is that negative words elicit slower responses than neutral or positive words on a host of cognitive tasks. Some researchers have speculated that negative stimuli elicit a general suppression of motor activity, akin to the freezing…

  17. Examining of Model Eliciting Activities Developed by Mathematics Student Teachers

    ERIC Educational Resources Information Center

    Dede, Ayse Tekin; Hidiroglu, Çaglar Naci; Güzel, Esra Bukova

    2017-01-01

    The purpose of this study is to examine the model eliciting activities developed by the mathematics student teachers in the context of the principles of the model eliciting activities. The participants of the study conducted as a case study design were twenty one mathematics student teachers working on seven groups. The data collection tools were…

  18. Freeze or Flee? Negative Stimuli Elicit Selective Responding

    ERIC Educational Resources Information Center

    Estes, Zachary; Verges, Michelle

    2008-01-01

    Humans preferentially attend to negative stimuli. A consequence of this automatic vigilance for negative valence is that negative words elicit slower responses than neutral or positive words on a host of cognitive tasks. Some researchers have speculated that negative stimuli elicit a general suppression of motor activity, akin to the freezing…

  19. Science Teachers' Elicitation Practices: Insights for Formative Assessment

    ERIC Educational Resources Information Center

    Ateh, Comfort M.

    2015-01-01

    In evaluating teachers' instructional decisions during instruction, it is clear that the nature of their elicitation is crucial for student learning. When instructional decisions are informed by information about students' conceptual understanding, significant learning is possible. This article examined the elicitation practices of two high school…

  20. Introducing Forum Theatre to Elicit and Advocate Children's Views

    ERIC Educational Resources Information Center

    Hammond, Nick

    2013-01-01

    Eliciting and advocating the voice of the child remains at the heart of international political agenda and also remains a central role for educational psychologists (EPs). Previous research indicates that EPs tend to use language-based methods for eliciting and advocating views of children. However, these approaches are often limited. Taking a…

  1. Protective antibody responses elicited by a meningococcal outer membrane vesicle vaccine with overexpressed genome-derived neisserial antigen 1870.

    PubMed

    Hou, Victor C; Koeberling, Oliver; Welsch, Jo Anne; Granoff, Dan M

    2005-08-15

    Background. Meningococcal outer membrane vesicle (OMV) vaccines are efficacious in humans but have serosubtype-specific serum bactericidal antibody responses directed at the porin protein PorA and the potential for immune selection of PorA-escape mutants.Methods. We prepared an OMV vaccine from a Neisseria meningitidis strain engineered to overexpress genome-derived neisserial antigen (GNA) 1870, a lipoprotein discovered by genome mining that is being investigated for use in a vaccine.Results. Mice immunized with the modified GNA1870-OMV vaccine developed broader serum bactericidal antibody responses than control mice immunized with a recombinant GNA1870 protein vaccine or an OMV vaccine prepared from wild-type N. meningitidis or a combination of vaccines prepared from wild-type N. meningitidis and recombinant protein. Antiserum from mice immunized with the modified GNA1870-OMV vaccine also elicited greater deposition of human C3 complement on the surface of live N. meningitidis bacteria and greater passive protective activity against meningococcal bacteremia in infant rats. A N. meningitidis mutant with decreased expression of PorA was more susceptible to bactericidal activity of anti-GNA1870 antibodies.Conclusions. The modified GNA1870-OMV vaccine elicits broader protection against meningococcal disease than recombinant GNA1870 protein or conventional OMV vaccines and also has less risk of selection of PorA-escape mutants than a conventional OMV vaccine.

  2. Protective Antibody Responses Elicited by a Meningococcal Outer Membrane Vesicle Vaccine with Overexpressed Genome-Derived Neisserial Antigen 1870

    PubMed Central

    Hou, Victor C.; Koeberling, Oliver; Welsch, Jo Anne; Granoff, Dan M.

    2008-01-01

    Background Meningococcal outer membrane vesicle (OMV) vaccines are efficacious in humans but have serosubtype-specific serum bactericidal antibody responses directed at the porin protein PorA and the potential for immune selection of PorA-escape mutants. Methods We prepared an OMV vaccine from a Neisseria meningitidis strain engineered to overexpress genome-derived neisserial antigen (GNA) 1870, a lipoprotein discovered by genome mining that is being investigated for use in a vaccine. Results Mice immunized with the modified GNA1870-OMV vaccine developed broader serum bactericidal antibody responses than control mice immunized with a recombinant GNA1870 protein vaccine or an OMV vaccine prepared from wild-type N. meningitidis or a combination of vaccines prepared from wild-type N. meningitidis and recombinant protein. Antiserum from mice immunized with the modified GNA1870-OMV vaccine also elicited greater deposition of human C3 complement on the surface of live N. meningitidis bacteria and greater passive protective activity against meningococcal bacteremia in infant rats. A N. meningitidis mutant with decreased expression of PorA was more susceptible to bactericidal activity of anti-GNA1870 antibodies. Conclusions The modified GNA1870-OMV vaccine elicits broader protection against meningococcal disease than recombinant GNA1870 protein or conventional OMV vaccines and also has less risk of selection of PorA-escape mutants than a conventional OMV vaccine. PMID:16028126

  3. Cross-protection provided by live Shigella mutants lacking major antigens.

    PubMed

    Szijártó, Valéria; Hunyadi-Gulyás, Eva; Emődy, Levente; Pál, Tibor; Nagy, Gábor

    2013-05-01

    The immune response elicited by Shigella infections is dominated by serotype-specific antibodies recognizing the LPS O-antigens. Although a marked antibody response to invasion plasmid antigens (Ipa-s) shared by all virulent strains is also induced, the varying level of immunity elicited by natural infections is serotype-restricted. Previous vaccines have tried to mimic and achieve this serotype-specific, infection-induced immunity. As, however, the four Shigella species can express 50 different types of O-antigens, current approaches with the aim to induce a broad coverage use a mixture of the most common O-antigens combined in single vaccines. In the current study we present data on an alternative approach to generate immunity protective against multiple serotypes. Mutants lacking both major immune-determinant structures (i.e. the Ipa and O-antigens) were not only highly attenuated, but, unlike their avirulent counterparts still expressing these antigens, elicited a protective immune response to heterologous serotypes in a murine model. Evidence is provided that protection was mediated by the enhanced immunogenic potential of minor conserved antigens. Furthermore, the rough, non-invasive double mutants triggered an immune response different from that induced by the smooth, invasive strains regarding the isotype of antibodies generated. These non-invasive, rough mutants may represent promising candidates for further development into live vaccines for the prophylaxis of bacillary dysentery in areas with multiple endemic serotypes.

  4. Bacteriorhodopsin mutants of Halobacterium sp. GRB. II. Characterization of mutants.

    PubMed

    Soppa, J; Otomo, J; Straub, J; Tittor, J; Meessen, S; Oesterhelt, D

    1989-08-05

    The bacterioopsin genes of Halobacterium sp. GRB (Ebert, K., Goebel, W., and Pfeifer, F. (1984) Mol. & Gen. Genet. 194, 91-97) wild type and 10 independent mutants of different phenotypes have been cloned and sequenced. The wild type gene has two conservative changes compared to the gene of Halobacterium halobium, so that the proteins of the two species are identical. Six different mutations at five different codons have been found, leading to the following amino acid changes compared to the wild type: Trp10----Cys (three cases), Tyr57----Asn, Asp85----Glu, Asp06----Asn (three cases), Asp96----Gly, Trp138----Arg. A first characterization of the mutant proteins is given, and their implications for models of bacteriorhodopsin structure and function are discussed.

  5. Mutant power: using mutant allele collections for yeast functional genomics

    PubMed Central

    Norman, Kaitlyn L.

    2016-01-01

    The budding yeast has long served as a model eukaryote for the functional genomic analysis of highly conserved signaling pathways, cellular processes and mechanisms underlying human disease. The collection of reagents available for genomics in yeast is extensive, encompassing a growing diversity of mutant collections beyond gene deletion sets in the standard wild-type S288C genetic background. We review here three main types of mutant allele collections: transposon mutagen collections, essential gene collections and overexpression libraries. Each collection provides unique and identifiable alleles that can be utilized in genome-wide, high-throughput studies. These genomic reagents are particularly informative in identifying synthetic phenotypes and functions associated with essential genes, including those modeled most effectively in complex genetic backgrounds. Several examples of genomic studies in filamentous/pseudohyphal backgrounds are provided here to illustrate this point. Additionally, the limitations of each approach are examined. Collectively, these mutant allele collections in Saccharomyces cerevisiae and the related pathogenic yeast Candida albicans promise insights toward an advanced understanding of eukaryotic molecular and cellular biology. PMID:26453908

  6. Mutant power: using mutant allele collections for yeast functional genomics.

    PubMed

    Norman, Kaitlyn L; Kumar, Anuj

    2016-03-01

    The budding yeast has long served as a model eukaryote for the functional genomic analysis of highly conserved signaling pathways, cellular processes and mechanisms underlying human disease. The collection of reagents available for genomics in yeast is extensive, encompassing a growing diversity of mutant collections beyond gene deletion sets in the standard wild-type S288C genetic background. We review here three main types of mutant allele collections: transposon mutagen collections, essential gene collections and overexpression libraries. Each collection provides unique and identifiable alleles that can be utilized in genome-wide, high-throughput studies. These genomic reagents are particularly informative in identifying synthetic phenotypes and functions associated with essential genes, including those modeled most effectively in complex genetic backgrounds. Several examples of genomic studies in filamentous/pseudohyphal backgrounds are provided here to illustrate this point. Additionally, the limitations of each approach are examined. Collectively, these mutant allele collections in Saccharomyces cerevisiae and the related pathogenic yeast Candida albicans promise insights toward an advanced understanding of eukaryotic molecular and cellular biology. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Similar Odorants Elicit Different Behavioral and Physiological Responses, Some Supersustained

    PubMed Central

    Montague, Shelby A.; Mathew, Dennis; Carlson, John R.

    2011-01-01

    An intriguing question in the field of olfaction is how animals distinguish among structurally similar odorants. We systematically analyzed olfactory responses elicited by a panel of 25 pyrazines. We found that structurally similar pyrazines elicit a wide range of behavioral responses from Drosophila larvae. Each pyrazine was tested against all functional receptors of the larval Odor receptor (Or) repertoire, yielding 525 odorant–receptor combinations. Different pyrazines vary markedly in the responses they elicit from the Or repertoire, with most strong responses deriving from two receptors, Or33b and Or59a. Surprisingly, 2-ethylpyrazine and 2-methylpyrazine, which elicit strikingly similar physiological responses across the receptor repertoire, elicit dramatically different behavioral responses. A small fraction of odorant-receptor combinations elicit remarkably long responses. These responses, which we term “supersustained” responses, are receptor specific and odorant specific, and can last for minutes. Such supersustained responses may prevent olfactory neurons from reporting contemporaneous information about the local odor environment. Odors that elicit such responses could provide a novel means of controlling insect pests and vectors of human disease by impairing the location of human hosts, food sources, and mates. PMID:21613503

  8. Immunogenic Response of Brucella canis virB10 and virB11 Mutants in a Murine Model

    PubMed Central

    Palomares-Resendiz, E.; Arellano-Reynoso, B.; Hernández-Castro, R.; Tenorio-Gutiérrez, V.; Salas-Téllez, E.; Suárez-Güemes, F.; Díaz-Aparicio, Efrén

    2012-01-01

    The virB locus, which encodes the type IV secretion system, is a major component of virulence in Brucella. A non-polar virB10 mutant and a virB11 deletion mutant were constructed in Brucella canis. In the mouse model, both mutants were cleared at day 21 post-infection, indicating reduced virulence in mice. After challenging with wild-type B. canis, the amounts of CFU recovered at day 15 were significantly lower in the group previously vaccinated with the virB10 mutant. Levels of IgG1, IgG2a, IgG2b, and IgM, the induction of the cytokines IL-2, IL-4, IL-10, and the production of IFN-γ were measured in lymphocyte cultures. All strains elicited similar levels of different antibody isotype profiles, and no significant differences were detected (P < 0.05). The wild-type strain induced a rapid and strong INF-γ response at 24 h, while both mutants induced mild INF-γ responses at 24 h, which remained constant over the course of sampling. Our results suggest that the virB mutants elicit a protective immunity and may be considered as candidates for studies to be conducted in dogs against canine brucellosis. PMID:22919627

  9. Immunogenic response of Brucella canis virB10 and virB11 mutants in a murine model.

    PubMed

    Palomares-Resendiz, E; Arellano-Reynoso, B; Hernández-Castro, R; Tenorio-Gutiérrez, V; Salas-Téllez, E; Suárez-Güemes, F; Díaz-Aparicio, Efrén

    2012-01-01

    The virB locus, which encodes the type IV secretion system, is a major component of virulence in Brucella. A non-polar virB10 mutant and a virB11 deletion mutant were constructed in Brucella canis. In the mouse model, both mutants were cleared at day 21 post-infection, indicating reduced virulence in mice. After challenging with wild-type B. canis, the amounts of CFU recovered at day 15 were significantly lower in the group previously vaccinated with the virB10 mutant. Levels of IgG1, IgG2a, IgG2b, and IgM, the induction of the cytokines IL-2, IL-4, IL-10, and the production of IFN-γ were measured in lymphocyte cultures. All strains elicited similar levels of different antibody isotype profiles, and no significant differences were detected (P < 0.05). The wild-type strain induced a rapid and strong INF-γ response at 24 h, while both mutants induced mild INF-γ responses at 24 h, which remained constant over the course of sampling. Our results suggest that the virB mutants elicit a protective immunity and may be considered as candidates for studies to be conducted in dogs against canine brucellosis.

  10. Temperature-sensitive mutants of Actinobacillus pleuropneumoniae induce protection in mice.

    PubMed Central

    Byrd, W; Hooke, A M

    1997-01-01

    Temperature-sensitive mutants of Actinobacillus pleuropneumoniae 4074, serotype 1, were isolated after treatment with nitrosoguanidine and enrichment with penicillin and D-cycloserine. Of the four temperature-sensitive mutants evaluated in mice, one (A-1) had a tight phenotype (i.e., it ceased replication immediately after transfer to the nonpermissive temperature [37 degrees C]) and three (1-2, 4-1, and 12-1) were coasters that continued replication for up to three generations after transfer to 37 degrees C. The reversion frequencies ranged from 10(-6) to 10(-9), and cutoff temperatures ranged from 33 to 35 degrees C. No major changes were detected in the biochemical profiles; agglutination reactions; electrophoretic profiles of the lipopolysaccharides, outer membrane proteins, and hemolysin proteins; hemolytic titers; or CAMP factor reactions of the mutants and the wild-type bacteria. Groups of 3- to 5-week-old, female ICR mice were immunized intranasally with three doses of 3.5 x 10(6) CFU of the mutants over 3 weeks and subsequently challenged intranasally with 5 50% lethal doses of the parental wild-type. Protection was induced by both the tight and the coaster mutants, with the 4-1 and 12-1 coasters eliciting greater protection (67 and 82%, respectively) than that induced by the A-1 tight mutant (57%). Intranasal immunization with both phenotypes induced serum antibody responses against the surface antigens and the hemolysin protein. PMID:9169752

  11. Nodules Initiated by Rhizobium meliloti Exopolysaccharide Mutants Lack a Discrete, Persistent Nodule Meristem 1

    PubMed Central

    Yang, Cheng; Signer, Ethan R.; Hirsch, Ann M.

    1992-01-01

    Infection of alfalfa with Rhizobium meliloti exo mutants deficient in exopolysaccharide results in abnormal root nodules that are devoid of bacteria and fail to fix nitrogen. Here we report further characterization of these abnormal nodules. Tightly curled root hairs or shepherd's crooks were found after inoculation with Rm 1021-derived exo mutants, but curling was delayed compared with wild-type Rm 1021. Infection threads were initiated in curled root hairs by mutants as well as by wild-type R. meliloti, but the exo mutant-induced threads aborted within the peripheral cells of the developing nodule. Also, nodules elicited by Rm 1021-derived exo mutants were more likely to develop on secondary roots than on the primary root. In contrast with wild-type R. meliloti-induced nodules, the exo mutant-induced nodules lacked a well defined apical meristem, presumably due to the abortion of the infection threads. The relationship of these findings to the physiology of nodule development is discussed. ImagesFigure 3Figure 1Figure 2Figure 4 PMID:16668605

  12. CCSI Risk Estimation: An Application of Expert Elicitation

    SciTech Connect

    Engel, David W.; Dalton, Angela C.

    2012-10-01

    The Carbon Capture Simulation Initiative (CCSI) is a multi-laboratory simulation-driven effort to develop carbon capture technologies with the goal of accelerating commercialization and adoption in the near future. One of the key CCSI technical challenges is representing and quantifying the inherent uncertainty and risks associated with developing, testing, and deploying the technology in simulated and real operational settings. To address this challenge, the CCSI Element 7 team developed a holistic risk analysis and decision-making framework. The purpose of this report is to document the CCSI Element 7 structured systematic expert elicitation to identify additional risk factors. We review the significance of and established approaches to expert elicitation, describe the CCSI risk elicitation plan and implementation strategies, and conclude by discussing the next steps and highlighting the contribution of risk elicitation toward the achievement of the overarching CCSI objectives.

  13. Eliciting knee jerk--a new method of reinforcement.

    PubMed

    Khanal, S; Sainju, R K; Adhikari, P; Thapa, R

    2007-12-01

    This study was designed to detect the sensitivity of different methods of eliciting knee jerks and to compare the conventional methods with the newly purposed maneuver. Knee jerk (a deep tendon reflex) was elicited in 123 apparently normal population (77 males and 46 females) with three different methods (1) without applying reinforcement, (2) applying Jendrassik maneuver (strong voluntary contraction of upper limbs) and (3) using the new method of reinforcement--that is by dorsiflexion of ankle joint of the same foot voluntarily as strong as possible on which the jerk would be elicitated. The sensitivity of the method without reinforcement was found to be is 87.8%; that with Jendrassik maneuver was 93.5%, whereas the sensitivity of newly proposed maneuver was 99.2%. Results of the present study have served to demonstrate that elicitation of knee jerk with newly proposed reinforcement maneuver is the best among all three methods.

  14. Picturing Masculinities: Using Photo-elicitation in Men's Health Research.

    PubMed

    Creighton, Genevieve M; Brussoni, Mariana; Oliffe, John L; Han, Christina

    2015-10-18

    This article explores the use of photo-elicitation methods in two men's health studies. Discussed are the ways that photo-elicitation can facilitate conversation about health issues that might be otherwise challenging to access. In the first study, researchers explored 35 young men's experiences of grief following the accidental death of a male peer. In the second study, researchers describe 64 fathers' perceptions about their roles and identity with respect to child safety and risk. Photographs and accompanying narratives were analyzed and results were theorized using a masculinities framework. Discussed are the benefits of photo-elicitation, which include facilitating conversation about emotions, garnering insight into the structures and identities of masculinity in the context of men's health. Considered also are some methodological challenges amid recommendations for ensuring reflexive practices. Based on the findings it is concluded that photo-elicitation can innovatively advance qualitative research in men's health.

  15. Knowledge Elicitation: Phase 1 Final Report. Volume 1

    DTIC Science & Technology

    1989-06-01

    artificial intelligence has been focused on methods for eliciting and representing expert knowledge (e.g., Newell and Simon, 1972; Schank and Abelson...methods. These issues have not yet been dealt with in a satisfactory way, either in the artificial intelligence community or by cognitive psychologists...ELICITATION 2.1 The Myth of "Mining for Nugets" of Knowledge The central question in the field of artificial intelligence, whether computers can be

  16. Paradoxical reactions elicited by diazepam in children with classic autism.

    PubMed

    Marrosu, F; Marrosu, G; Rachel, M G; Biggio, G

    1987-01-01

    Administration of diazepam (10 mg i.m.) to seven children (two girls and five boys) affected by infantile autism elicited paradoxical behavioural responses. Mainly, anxiogenic effect, unsocialized aggressive behaviour and explosive aggression were dramatically increased in comparison with the same symptoms present before and after treatment. The results show for the first time that benzodiazepines may elicit paradoxical behavioural response in autistic children. The possible involvement of an altered function at the level of GABA/benzodiazepine receptor complex is discussed.

  17. Proposed Nomenclature for Mutants of Adenoviruses

    PubMed Central

    Ginsberg, Harold S.; Williams, James F.; Doerfler, Walter H.; Shimojo, Hiroto

    1973-01-01

    In accord with the nomenclature proposed for mutants of simian virus 40 the same rules, with minor modifications, are recommended for naming mutants of adenoviruses. It is further suggested that these rules, which pertain to a system of classification based primarily upon complementation analysis, also be applied to mutants of other DNA-containing animal viruses. PMID:4355864

  18. Problem-Solving Test: Tryptophan Operon Mutants

    ERIC Educational Resources Information Center

    Szeberenyi, Jozsef

    2010-01-01

    This paper presents a problem-solving test that deals with the regulation of the "trp" operon of "Escherichia coli." Two mutants of this operon are described: in mutant A, the operator region of the operon carries a point mutation so that it is unable to carry out its function; mutant B expresses a "trp" repressor protein unable to bind…

  19. Problem-Solving Test: Tryptophan Operon Mutants

    ERIC Educational Resources Information Center

    Szeberenyi, Jozsef

    2010-01-01

    This paper presents a problem-solving test that deals with the regulation of the "trp" operon of "Escherichia coli." Two mutants of this operon are described: in mutant A, the operator region of the operon carries a point mutation so that it is unable to carry out its function; mutant B expresses a "trp" repressor protein unable to bind…

  20. Elicitation of hypersensitive responses in Nicotiana glutinosa by the suppressor of RNA silencing protein P0 from poleroviruses.

    PubMed

    Wang, Ken-Der; Empleo, Roman; Nguyen, Tan Tri V; Moffett, Peter; Sacco, Melanie Ann

    2015-06-01

    Plant disease resistance (R) proteins that confer resistance to viruses recognize viral gene products with diverse functions, including viral suppressors of RNA silencing (VSRs). The P0 protein from poleroviruses is a VSR that targets the ARGONAUTE1 (AGO1) protein for degradation, thereby disrupting RNA silencing and antiviral defences. Here, we report resistance against poleroviruses in Nicotiana glutinosa directed against Turnip yellows virus (TuYV) and Potato leafroll virus (PLRV). The P0 proteins from TuYV (P0(T) (u) ), PLRV (P0(PL) ) and Cucurbit aphid-borne yellows virus (P0(CA) ) were found to elicit a hypersensitive response (HR) in N. glutinosa accession TW59, whereas other accessions recognized P0(PL) only. Genetic analysis showed that recognition of P0(T) (u) by a resistance gene designated RPO1 (Resistance to POleroviruses 1) is inherited as a dominant allele. Expression of P0 from a Potato virus X (PVX) expression vector transferred recognition to the recombinant virus on plants expressing RPO1, supporting P0 as the unique Polerovirus factor eliciting resistance. The induction of HR required a functional P0 protein, as P0(T) (u) mutants with substitutions in the F-box motif that abolished VSR activity were unable to elicit HR. We surmised that the broad P0 recognition seen in TW59 and the requirement for the F-box protein motif could indicate detection of P0-induced AGO1 degradation and disruption of RNA silencing; however, other viral silencing suppressors, including the PVX P25 that also causes AGO1 degradation, failed to elicit HR in N. glutinosa. Investigation of P0 elicitation of RPO1 could provide insight into P0 activities within the cell that trigger resistance. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  1. Elicitation of natural language representations of uncertainty using computer technology

    SciTech Connect

    Tonn, B.; Goeltz, R.; Travis, C.; Tennessee Univ., Knoxville, TN )

    1989-01-01

    Knowledge elicitation is an important aspect of risk analysis. Knowledge about risks must be accurately elicited from experts for use in risk assessments. Knowledge and perceptions of risks must also be accurately elicited from the public in order to intelligently perform policy analysis and develop and implement programs. Oak Ridge National Laboratory is developing computer technology to effectively and efficiently elicit knowledge from experts and the public. This paper discusses software developed to elicit natural language representations of uncertainty. The software is written in Common Lisp and resides on VAX Computers System and Symbolics Lisp machines. The software has three goals, to determine preferences for using natural language terms for representing uncertainty; likelihood rankings of the terms; and how likelihood estimates are combined to form new terms. The first two goals relate to providing useful results for those interested in risk communication. The third relates to providing cognitive data to further our understanding of people's decision making under uncertainty. The software is used to elicit natural language terms used to express the likelihood of various agents causing cancer in humans and cancer resulting in various maladies, and the likelihood of everyday events. 6 refs., 4 figs., 4 tabs.

  2. Expert elicitation and the problem of detecting undeclared activities

    SciTech Connect

    Pilat, Joseph F.; Sylvester, K. B.; Stanbro, W. D.

    2002-01-01

    Measures applicable to the detection of undeclared activities are not well established, and their effectiveness is uncertain. To detect clandestine paths, the IAEA is still developing processes and procedures. As the Agency gains experience with new measures and with integrated safeguards, dealing with such problems may become more experience-based and perhaps more closely parallel the process with current safeguards where detection probabilities for the measures to be utilized on declared paths are well characterized. Whether or not this point will be reached for undeclared and mixed paths, the only tool that appears suitable at present for the purpose of generating a reasonable detection probability that can over time be tested against reality and, if necessary, adjusted is formal expert judgment, or expert elicitation. Formal expert elicitation is a structured process that makes use of people knowledgeable in certain areas to make assessments. To provide a 'proof of principle' of this methodology for presentation to the Agency, experts in nuclear technology, nonproliferation, safeguards and open source information, as well as in formal expert elicitation processes, engaged in three illustrative expert elicitations on assessing information analysis as a means to detect undeclared activities. These elicitations were successful. This paper will discuss the process of and issues raised by the elicitations.

  3. Design of Meningococcal Factor H Binding Protein Mutant Vaccines That Do Not Bind Human Complement Factor H

    PubMed Central

    Pajon, Rolando; Beernink, Peter T.

    2012-01-01

    Meningococcal factor H binding protein (fHbp) is a human species-specific ligand for the complement regulator, factor H (fH). In recent studies, fHbp vaccines in which arginine at position 41 was replaced by serine (R41S) had impaired fH binding. The mutant vaccines elicited bactericidal responses in human fH transgenic mice superior to those elicited by control fHbp vaccines that bound human fH. Based on sequence similarity, fHbp has been classified into three variant groups. Here we report that although R41 is present in fHbp from variant groups 1 and 2, the R41S substitution eliminated fH binding only in variant group 1 proteins. To identify mutants in variant group 2 with impaired fH binding, we generated fHbp structural models and predicted 63 residues influencing fH binding. From these, we created 11 mutants with one or two amino acid substitutions in a variant group 2 protein and identified six that decreased fH binding. Three of these six mutants retained conformational epitopes recognized by all six anti-fHbp monoclonal antibodies (MAbs) tested and elicited serum complement-mediated bactericidal antibody titers in wild-type mice that were not significantly different from those obtained with the control vaccine. Thus, fHbp amino acid residues that affect human fH binding differ across variant groups. This result suggests that fHbp sequence variation induced by immune selection also affects fH binding motifs via coevolution. The three new fHbp mutants from variant group 2, which do not bind human fH, retained important epitopes for eliciting bactericidal antibodies and may be promising vaccine candidates. PMID:22615247

  4. Design of meningococcal factor H binding protein mutant vaccines that do not bind human complement factor H.

    PubMed

    Pajon, Rolando; Beernink, Peter T; Granoff, Dan M

    2012-08-01

    Meningococcal factor H binding protein (fHbp) is a human species-specific ligand for the complement regulator, factor H (fH). In recent studies, fHbp vaccines in which arginine at position 41 was replaced by serine (R41S) had impaired fH binding. The mutant vaccines elicited bactericidal responses in human fH transgenic mice superior to those elicited by control fHbp vaccines that bound human fH. Based on sequence similarity, fHbp has been classified into three variant groups. Here we report that although R41 is present in fHbp from variant groups 1 and 2, the R41S substitution eliminated fH binding only in variant group 1 proteins. To identify mutants in variant group 2 with impaired fH binding, we generated fHbp structural models and predicted 63 residues influencing fH binding. From these, we created 11 mutants with one or two amino acid substitutions in a variant group 2 protein and identified six that decreased fH binding. Three of these six mutants retained conformational epitopes recognized by all six anti-fHbp monoclonal antibodies (MAbs) tested and elicited serum complement-mediated bactericidal antibody titers in wild-type mice that were not significantly different from those obtained with the control vaccine. Thus, fHbp amino acid residues that affect human fH binding differ across variant groups. This result suggests that fHbp sequence variation induced by immune selection also affects fH binding motifs via coevolution. The three new fHbp mutants from variant group 2, which do not bind human fH, retained important epitopes for eliciting bactericidal antibodies and may be promising vaccine candidates.

  5. Infection with diverse immune-modulating poxviruses elicits different compositional shifts in the mouse gut microbiome

    PubMed Central

    Hernáez, Bruno; Rastrojo, Alberto; Alcamí, Antonio

    2017-01-01

    It is often not possible to demonstrate causality within the context of gut microbiota dysbiosis-linked diseases. Thus, we need a better understanding of the mechanisms whereby an altered host immunophysiology shapes its resident microbiota. In this regard, immune-modulating poxvirus strains and mutants could differentially alter gut mucosal immunity in the context of a natural immune response, providing a controlled natural in vivo setting to deepen our understanding of the immune determinants of microbiome composition. This study represents a proof-of-concept that the use of an existing collection of different immune-modulating poxviruses may represent an innovative tool in gut microbiome research. To this end, 16S rRNA amplicon sequencing and RNAseq transcriptome profiling were employed as proxies for microbiota composition and gut immunophysiological status in the analysis of caecal samples from control mice and mice infected with various poxvirus types. Our results show that different poxvirus species and mutants elicit different shifts in the mice mucosa-associated microbiota and, in some instances, significant concomitant shifts in gut transcriptome profiles, thus providing an initial validation to the proposed model. PMID:28282449

  6. Mitochondrial respiratory dysfunction-elicited oxidative stress and posttranslational protein modification in mitochondrial diseases.

    PubMed

    Wu, Yu-Ting; Wu, Shi-Bei; Lee, Wan-Yu; Wei, Yau-Huei

    2010-07-01

    Pathogenic mutation in mtDNA and mitochondrial dysfunction are associated with mitochondrial diseases. In this review, we discuss the oxidative stress-elicited mitochondrial protein modifications that may contribute to the pathophysiology of mitochondrial diseases. We demonstrated that excess ROS produced by defective mitochondria could increase the acetylation of microtubule proteins through the suppression of Sirt2, which results in perinuclear distribution of mitochondria in skin fibroblasts of patients with CPEO syndrome. Our recent work showed that mitochondrial dysfunction-induced oxidative stress can disrupt protein degradation system by inhibiting the ubiquitin-proteasome pathway and protease activity in human cells harboring mutant mtDNA. This in turn causes accumulation of aberrant proteins in mitochondria and renders the mutant cells more susceptible to apoptosis induced by oxidative stress. Furthermore, oxidative stress can modulate phosphorylation of mitochondrial proteins, which can affect metabolism in a number of diseases. Taken together, we suggest that oxidative stress-triggered protein modifications and defects in protein turnover play an important role in the pathogenesis and progression of mitochondrial diseases.

  7. Identification and characterization of a well-defined series of coronatine biosynthetic mutants of Pseudomonas syringae pv. tomato DC3000.

    PubMed

    Brooks, David M; Hernández-Guzmán, Gustavo; Kloek, Andrew P; Alarcón-Chaidez, Francisco; Sreedharan, Aswathy; Rangaswamy, Vidhya; Peñaloza-Vázquez, Alejandro; Bender, Carol L; Kunkel, Barbara N

    2004-02-01

    To identify Pseudomonas syringae pv. tomato genes involved in pathogenesis, we carried out a screen for Tn5 mutants of P. syringae pv. tomato DC3000 with reduced virulence on Arabidopsis thaliana. Several mutants defining both known and novel virulence loci were identified. Six mutants contained insertions in biosynthetic genes for the phytotoxin coronatine (COR). The P. syringae pv. tomato DC3000 COR genes are chromosomally encoded and are arranged in two separate clusters, which encode enzymes responsible for the synthesis of coronafacic acid (CFA) or coronamic acid (CMA), the two defined intermediates in COR biosynthesis. High-performance liquid chromatography fractionation and exogenous feeding studies confirmed that Tn5 insertions in the cfa and cma genes disrupt CFA and CMA biosynthesis, respectively. All six COR biosynthetic mutants were significantly impaired in their ability to multiply to high levels and to elicit disease symptoms on A. thaliana plants. To assess the relative contributions of CFA, CMA, and COR in virulence, we constructed and characterized cfa6 cmaA double mutant strains. These exhibited virulence phenotypes on A. thalliana identical to those observed for the cmaA or cfa6 single mutants, suggesting that reduced virulence of these mutants on A. thaliana is caused by the absence of the intact COR toxin. This is the first study to use biochemically and genetically defined COR mutants to address the role of COR in pathogenesis.

  8. Nif- Hup- mutants of Rhizobium japonicum.

    PubMed Central

    Moshiri, F; Stults, L; Novak, P; Maier, R J

    1983-01-01

    Two H2 uptake-negative (Hup-) Rhizobium japonicum mutants were obtained that also lacked symbiotic N2 fixation (acetylene reduction) activity. One of the mutants formed green nodules and was deficient in heme. Hydrogen oxidation activity in this mutant could be restored by the addition of heme plus ATP to crude extracts. Bacteroid extracts from the other mutant strain lacked hydrogenase activity and activity for both of the nitrogenase component proteins. Hup+ revertants of the mutant strains regained both H2 uptake ability and nitrogenase activity. Images PMID:6874648

  9. Bioprocess optimization of furanocoumarin elicitation by medium renewal and re-elicitation: a perfusion-based approach.

    PubMed

    Diwan, Renuka; Malpathak, Nutan

    2011-03-01

    Effect of various abiotic (methyl jasmonate, salicylic acid) and biotic (yeast extract, Aspergillus niger) elicitors on furanocoumarin production and in situ product removal was studied using shoot cultures of Ruta graveolens L. Elicitation by yeast extract (1% w/v) on day 15 was most effective. It led to 7.8-fold higher furanocoumarin production that was attained 24 h after elicitation and 43% of the product was released into the medium. Changes in the relative concentration of furanocoumarins produced depend on the elicitor used. Molar ratio of bergapten increased to 93% in response to yeast extract. With the perspective of developing a commercially feasible process, an approach for preserving viability of biomass and its reuse needs to be developed. For this, medium renewal strategy was investigated. Removal of the spent medium 48 h after elicitation allowed in situ product removal and proved effective in revival of cultures, allowing reuse of biomass. A week after medium renewal, the revived biomass was re-elicited and a second furanocoumarin production peak was obtained. A perfusion-based bioprocess optimization approach, employing elicitation coupled with medium renewal with subsequent re-elicitation, as a new strategy for improved furanocoumarin production, has been suggested.

  10. Elicitation of structure-specific antibodies by epitope scaffolds

    PubMed Central

    Ofek, Gilad; Guenaga, F. Javier; Schief, William R.; Skinner, Jeff; Baker, David; Wyatt, Richard; Kwong, Peter D.

    2010-01-01

    Elicitation of antibodies against targets that are immunorecessive, cryptic, or transient in their native context has been a challenge for vaccine design. Here we demonstrate the elicitation of structure-specific antibodies against the HIV-1 gp41 epitope of the broadly neutralizing antibody 2F5. This conformationally flexible region of gp41 assumes mostly helical conformations but adopts a kinked, extended structure when bound by antibody 2F5. Computational techniques were employed to transplant the 2F5 epitope into select acceptor scaffolds. The resultant “2F5-epitope scaffolds” possessed nanomolar affinity for antibody 2F5 and a range of epitope flexibilities and antigenic specificities. Crystallographic characterization of the epitope scaffold with highest affinity and antigenic discrimination confirmed good to near perfect attainment of the target conformation for the gp41 molecular graft in free and 2F5-bound states, respectively. Animals immunized with 2F5-epitope scaffolds showed levels of graft-specific immune responses that correlated with graft flexibility (p < 0.04), while antibody responses against the graft—as dissected residue-by-residue with alanine substitutions—resembled more closely those of 2F5 than sera elicited with flexible or cyclized peptides, a resemblance heightened by heterologous prime-boost. Lastly, crystal structures of a gp41 peptide in complex with monoclonal antibodies elicited by the 2F5-epitope scaffolds revealed that the elicited antibodies induce gp41 to assume its 2F5-recognized shape. Epitope scaffolds thus provide a means to elicit antibodies that recognize a predetermined target shape and sequence, even if that shape is transient in nature, and a means by which to dissect factors influencing such elicitation. PMID:20876137

  11. Iron-regulated metabolites produced by Pseudomonas fluorescens WCS374r are not required for eliciting induced systemic resistance against Pseudomonas syringae pv. tomato in Arabidopsis.

    PubMed

    Djavaheri, Mohammad; Mercado-Blanco, Jesús; Versluis, C; Meyer, J-M; Loon, L C; Bakker, Peter A H M

    2012-09-01

    The plant growth-promoting rhizobacterium Pseudomonas fluorescens WCS374r produces several iron-regulated metabolites, including the fluorescent siderophore pseudobactin (Psb374), salicylic acid (SA), and pseudomonine (Psm), a siderophore that contains a SA moiety. After purification of Psb374 from culture supernatant of WCS374r, its structure was determined following isoelectrofocusing and tandem mass spectrometry, and found to be identical to the fluorescent siderophore produced by P. fluorescens ATCC 13525. To study the role of SA and Psm production in colonization of Arabidopsis thaliana roots and in induced systemic resistance (ISR) against Pseudomonas syringae pv. tomato (Pst) by strain WCS374r, mutants disrupted in the production of these metabolites were obtained by homologous recombination. These mutants were further subjected to transposon Tn5 mutagenesis to generate mutants also deficient in Psb374 production. The mutants behaved similar to the wild type in both their Arabidopsis rhizosphere-colonizing capacity and their ability to elicit ISR against Pst. We conclude that Psb374, SA, and Psm production by P. fluorescens WCS374r are not required for eliciting ISR in Arabidopsis.

  12. Herpes Simplex Virus 2 ICP0− Mutant Viruses Are Avirulent and Immunogenic: Implications for a Genital Herpes Vaccine

    PubMed Central

    Halford, William P.; Püschel, Ringo; Rakowski, Brandon

    2010-01-01

    Herpes simplex virus 1 (HSV-1) ICP0− mutants are interferon-sensitive, avirulent, and elicit protective immunity against HSV-1 (Virol J, 2006, 3:44). If an ICP0− mutant of herpes simplex virus 2 (HSV-2) exhibited similar properties, such a virus might be used to vaccinate against genital herpes. The current study was initiated to explore this possibility. Several HSV-2 ICP0− mutant viruses were constructed and evaluated in terms of three parameters: i. interferon-sensitivity; ii. virulence in mice; and iii. capacity to elicit protective immunity against HSV-2. One ICP0− mutant virus in particular, HSV-2 0ΔNLS, achieved an optimal balance between avirulence and immunogenicity. HSV-2 0ΔNLS was interferon-sensitive in cultured cells. HSV-2 0ΔNLS replicated to low levels in the eyes of inoculated mice, but was rapidly repressed by an innate, Stat 1-dependent host immune response. HSV-2 0ΔNLS failed to spread from sites of inoculation, and hence produced only inapparent infections. Mice inoculated with HSV-2 0ΔNLS consistently mounted an HSV-specific IgG antibody response, and were consistently protected against lethal challenge with wild-type HSV-2. Based on their avirulence and immunogenicity, we propose that HSV-2 ICP0− mutant viruses merit consideration for their potential to prevent the spread of HSV-2 and genital herpes. PMID:20808928

  13. Herpes simplex virus 2 ICP0 mutant viruses are avirulent and immunogenic: implications for a genital herpes vaccine.

    PubMed

    Halford, William P; Püschel, Ringo; Rakowski, Brandon

    2010-08-17

    Herpes simplex virus 1 (HSV-1) ICP0(-) mutants are interferon-sensitive, avirulent, and elicit protective immunity against HSV-1 (Virol J, 2006, 3:44). If an ICP0(-) mutant of herpes simplex virus 2 (HSV-2) exhibited similar properties, such a virus might be used to vaccinate against genital herpes. The current study was initiated to explore this possibility. Several HSV-2 ICP0(-) mutant viruses were constructed and evaluated in terms of three parameters: i. interferon-sensitivity; ii. virulence in mice; and iii. capacity to elicit protective immunity against HSV-2. One ICP0(-) mutant virus in particular, HSV-2 0DeltaNLS, achieved an optimal balance between avirulence and immunogenicity. HSV-2 0DeltaNLS was interferon-sensitive in cultured cells. HSV-2 0DeltaNLS replicated to low levels in the eyes of inoculated mice, but was rapidly repressed by an innate, Stat 1-dependent host immune response. HSV-2 0DeltaNLS failed to spread from sites of inoculation, and hence produced only inapparent infections. Mice inoculated with HSV-2 0DeltaNLS consistently mounted an HSV-specific IgG antibody response, and were consistently protected against lethal challenge with wild-type HSV-2. Based on their avirulence and immunogenicity, we propose that HSV-2 ICP0(-) mutant viruses merit consideration for their potential to prevent the spread of HSV-2 and genital herpes.

  14. The Appearance of Phosphenes Elicited Using a Suprachoroidal Retinal Prosthesis.

    PubMed

    Sinclair, Nicholas C; Shivdasani, Mohit N; Perera, Thushara; Gillespie, Lisa N; McDermott, Hugh J; Ayton, Lauren N; Blamey, Peter J

    2016-09-01

    Phosphenes are the fundamental building blocks for presenting meaningful visual information to the visually impaired using a bionic eye device. The aim of this study was to characterize the size, shape, and location of phosphenes elicited using a suprachoroidal retinal prosthesis. Three patients with profound vision loss due to retinitis pigmentosa were implanted with a suprachoroidal electrode array, which was used to deliver charge-balanced biphasic constant-current pulses at various rates, amplitudes, and durations to produce phosphenes. Tasks assessing phosphene appearance, location, overlap, and the patients' ability to recognize phosphenes were performed using a custom psychophysics setup. Phosphenes were reliably elicited in all three patients, with marked differences in the reported appearances between patients and between electrodes. Phosphene shapes ranged from simple blobs to complex forms with multiple components in both space and time. Phosphene locations within the visual field generally corresponded to the retinotopic position of the stimulating electrodes. Overlap between phosphenes elicited from adjacent electrodes was observed with one patient, which reduced with increasing electrode separation. In a randomized recognition task, two patients correctly identified the electrode being stimulated for 57.2% and 23% of trials, respectively. Phosphenes of varying complexity were successfully elicited in all three patients, indicating that the suprachoroidal space is an efficacious site for electrically stimulating the retina. The recognition scores obtained with two patients suggest that a suprachoroidal implant can elicit phosphenes containing unique information. This information may be useful when combining phosphenes into more complex and meaningful images that provide functional vision.

  15. Cortical activity elicited by isolated vowels and diphthongs.

    PubMed

    Mäkelä, A M; Alku, P; May, P J C; Mäkinen, V; Tiitinen, H

    2004-11-30

    Cortical activity underlying speech perception has been studied mostly by using isolated vowels with constant formant frequencies. Speech, however, is characterized by formant transitions whereby formant frequencies change as a function of time. We used magnetoencephalography (MEG) to investigate cortical activity elicited by isolated vowels and diphthongs containing formant transitions. Ten subjects were presented with two isolated vowels /a/ and /u/ and diphthongs /au/ and /ua/. Stimulus duration was 200 ms, and the diphthongs started and ended with a 50-ms constant-formant period and included a 100-ms linear transition period. Apart from studying the auditory N100m response, we examined subsequent brain activity in a 500-ms poststimulus time window, as the transitions were expected to elicit activity also in later stages of cognitive processing. All the stimuli elicited prominent N100m responses. Thereafter, both the isolated vowels and diphthongs elicited sustained brain activity lasting up to 500 ms. The present observations indicate that identification of the speech sounds as well as changes in their identity are reflected in the auditory N100m. Notably, the stimuli appeared to elicit left-hemispheric activity resembling the N400, typically obtained by using more complicated speech stimuli such as words and sentences.

  16. Selection of chemotaxis mutants of Dictyostelium discoideum

    PubMed Central

    1987-01-01

    A method has been developed for the efficient selection of chemotaxis mutants of Dictyostelium discoideum. Mutants defective in the chemotactic response to folate could be enriched up to 30-fold in one round of selection using a chamber in which a compartment that contained the chemoattractant was separated by a sandwich of four nitrocellulose filters from a compartment that contained buffer. Mutagenized cells were placed in the center of the filter layer and exposed to the attractant gradient built up between the compartments for a period of 3-4 h. While wild-type cells moved through the filters in a wave towards the compartment that contained attractant, mutant cells remained in the filter to which they were applied. After several repetitions of the selection procedure, mutants defective in chemotaxis made up 10% of the total cell population retained in that filter. Mutants exhibiting three types of alterations were collected: motility mutants with either reduced speed of movement, or altered rates of turning; a single mutant defective in production of the attractant- degrading enzyme, folate deaminase; and mutants with normal motility but reduced chemotactic responsiveness. One mutant showed drastically reduced sensitivity in folate-induced cGMP production. Morphogenetic alterations of mutants defective in folate chemotaxis are described. PMID:3793759

  17. Gravitropism of inflorescence stems in starch-deficient mutants of Arabidopsis

    NASA Technical Reports Server (NTRS)

    Weise, S. E.; Kiss, J. Z.

    1999-01-01

    Previous studies have assayed the gravitropic response of roots and hypocotyls of wild type Arabidopsis thaliana, two reduced-starch strains, and a starchless strain. Because there have been few reports on inflorescence gravitropism, in this article, we use microscopic analyses and time-course studies of these mutants and their wild type to study gravitropism in these stems. Sedimentation of plastids was observed in endodermal cells of the wild type and reduced-starch mutants but not in the starchless mutant. In all of these strains, the short inflorescence stems (1.0-2.9 cm) were less responsive to the gravistimulus compared with the long stems (3.0-6.0 cm). In both long and short inflorescence stems, the wild type initially had the greatest response; the starchless mutant had the least response; and the reduced starch mutants exhibited an intermediate response. Furthermore, growth rates among all four strains were approximately equal. At about 6 h after reorientation, inflorescences of all strains returned to a position parallel to the gravity vector. Thus, in inflorescence stems, sedimentation of plastids may act as an accelerator but is not required to elicit a gravitropic response. Furthermore, the site of perception appears to be diffuse throughout the inflorescence stem. These results are consistent with both a plastid-based statolith model and the protoplast pressure hypothesis, and it is possible that multiple systems for gravity perception occur in plant cells.

  18. Mutants of staphylococcal toxic shock syndrome toxin 1: mitogenicity and recognition by a neutralizing monoclonal antibody.

    PubMed Central

    Blanco, L; Choi, E M; Connolly, K; Thompson, M R; Bonventre, P F

    1990-01-01

    Toxic shock syndrome toxin 1 (TSST-1), a 22-kilodalton protein made by strains of Staphylococcus aureus harboring the chromosomal toxin gene, may elicit toxic shock syndrome in humans. In vitro, TSST-1 induces T cells to proliferate and macrophages to secrete interleukin-1. To conduct a structure-function analysis, point mutations on the TSST-1 gene were generated by site-directed mutagenesis to identify amino acids critical for activity of the toxin. Specific tyrosine and histidine residues were replaced by alanines. Wild-type and mutant TSST-1 gene constructs were expressed in Escherichia coli, and the products were tested for their mitogenic potential and reactivity with a TSST-1 neutralizing monoclonal antibody (MAb 8-5-7). Four of the mutants were similar to the wild type; i.e., the mutant toxins stimulated murine T cells and reacted with MAb 8-5-7 equally as well as the wild type. Two mutants exhibited a decrease in mitogenic activity, but one of these retained the capacity to bind with MAb 8-5-7 while the other was no longer recognized by the same antibody. One double mutant demonstrated minimal mitogenic activity and did not react in enzyme-linked immunosorbent and immunoblot assays with MAb 8-5-7. The data show that specific residues near the carboxy terminus of TSST-1 are essential for mitogenic activity and in forming the epitope recognized by neutralizing MAb 8-5-7. Images PMID:1696937

  19. Gravitropism of inflorescence stems in starch-deficient mutants of Arabidopsis

    NASA Technical Reports Server (NTRS)

    Weise, S. E.; Kiss, J. Z.

    1999-01-01

    Previous studies have assayed the gravitropic response of roots and hypocotyls of wild type Arabidopsis thaliana, two reduced-starch strains, and a starchless strain. Because there have been few reports on inflorescence gravitropism, in this article, we use microscopic analyses and time-course studies of these mutants and their wild type to study gravitropism in these stems. Sedimentation of plastids was observed in endodermal cells of the wild type and reduced-starch mutants but not in the starchless mutant. In all of these strains, the short inflorescence stems (1.0-2.9 cm) were less responsive to the gravistimulus compared with the long stems (3.0-6.0 cm). In both long and short inflorescence stems, the wild type initially had the greatest response; the starchless mutant had the least response; and the reduced starch mutants exhibited an intermediate response. Furthermore, growth rates among all four strains were approximately equal. At about 6 h after reorientation, inflorescences of all strains returned to a position parallel to the gravity vector. Thus, in inflorescence stems, sedimentation of plastids may act as an accelerator but is not required to elicit a gravitropic response. Furthermore, the site of perception appears to be diffuse throughout the inflorescence stem. These results are consistent with both a plastid-based statolith model and the protoplast pressure hypothesis, and it is possible that multiple systems for gravity perception occur in plant cells.

  20. Gravitropism of inflorescence stems in starch-deficient mutants of Arabidopsis.

    PubMed

    Weise, S E; Kiss, J Z

    1999-01-01

    Previous studies have assayed the gravitropic response of roots and hypocotyls of wild type Arabidopsis thaliana, two reduced-starch strains, and a starchless strain. Because there have been few reports on inflorescence gravitropism, in this article, we use microscopic analyses and time-course studies of these mutants and their wild type to study gravitropism in these stems. Sedimentation of plastids was observed in endodermal cells of the wild type and reduced-starch mutants but not in the starchless mutant. In all of these strains, the short inflorescence stems (1.0-2.9 cm) were less responsive to the gravistimulus compared with the long stems (3.0-6.0 cm). In both long and short inflorescence stems, the wild type initially had the greatest response; the starchless mutant had the least response; and the reduced starch mutants exhibited an intermediate response. Furthermore, growth rates among all four strains were approximately equal. At about 6 h after reorientation, inflorescences of all strains returned to a position parallel to the gravity vector. Thus, in inflorescence stems, sedimentation of plastids may act as an accelerator but is not required to elicit a gravitropic response. Furthermore, the site of perception appears to be diffuse throughout the inflorescence stem. These results are consistent with both a plastid-based statolith model and the protoplast pressure hypothesis, and it is possible that multiple systems for gravity perception occur in plant cells.

  1. Honey-sensitive Pseudomonas aeruginosa mutants are impaired in catalase A.

    PubMed

    Bolognese, Fabrizio; Bistoletti, Michela; Barbieri, Paola; Orlandi, Viviana Teresa

    2016-09-01

    The antimicrobial power of honey seems to be ascribable to several factors, including oxidative and osmotic stress. The aim of this study was to find genetic determinants involved in the response to honey stress in the opportunistic pathogen Pseudomonas aeruginosa, chosen as model micro-organism. A library of transposon mutants of P. aeruginosa PAO1 was constructed and only four mutants unable to grow in presence of fir honeydew honey were selected. All four mutants were impaired in the major H2O2-scavenging enzyme catalase A (KatA). The knockout of katA gene caused sensitivity, as expected, not only to hydrogen peroxide but also to different types of honey including Manuka GMO 220 honey. Genetic complementation, as well as the addition of PAO1 supernatant containing extracellular catalase, restored tolerance to honey stress in all the mutants. As P. aeruginosa PAO1 catalase KatA copes with H2O2 stress, it is conceivable that the antimicrobial activity of honey is, at least partially, due to the presence of hydrogen peroxide in honey or the ability of honey to induce production of hydrogen peroxide. The katA-deficient mutants could be used as tester micro-organisms to compare the power of different types of natural and curative honeys in eliciting oxidative stress mediated by hydrogen peroxide.

  2. Elicitability of muscle cramps in different leg and foot muscles.

    PubMed

    Minetto, Marco Alessandro; Botter, Alberto

    2009-10-01

    To explore the efficacy of muscle motor point stimulation in eliciting muscle cramps, 11 subjects underwent eight sessions of electrical stimulation of the following muscles bilaterally: abductor hallucis flexor hallucis brevis, and both heads of the gastrocnemius muscles. Bursts of 150 square wave stimuli (duration: 152 micros; current intensity: 30% supramaximal) were applied. The stimulation frequency was increased from 4 pulses per second (pps) at increments of 2 pps until a cramp was induced. The number of cramps that could be elicited was smaller in flexor hallucis brevis than in abductor hallucis (16 vs. 22 out of 22 trials each; P < 0.05) and in the lateral gastrocnemius than in the medial gastrocnemius (5 vs. 20 out of 22 trials each; P < 0.0001). We show that leg and foot muscles have different cramp susceptibility, and the intermuscle variability in the elicitability profile for electrically induced cramps supports the use of the proposed method for cramp research.

  3. Biologically inspired robots elicit a robust fear response in zebrafish

    NASA Astrophysics Data System (ADS)

    Ladu, Fabrizio; Bartolini, Tiziana; Panitz, Sarah G.; Butail, Sachit; Macrı, Simone; Porfiri, Maurizio

    2015-03-01

    We investigate the behavioral response of zebrafish to three fear-evoking stimuli. In a binary choice test, zebrafish are exposed to a live allopatric predator, a biologically-inspired robot, and a computer-animated image of the live predator. A target tracking algorithm is developed to score zebrafish behavior. Unlike computer-animated images, the robotic and live predator elicit a robust avoidance response. Importantly, the robotic stimulus elicits more consistent inter-individual responses than the live predator. Results from this effort are expected to aid in hypothesis-driven studies on zebrafish fear response, by offering a valuable approach to maximize data-throughput and minimize animal subjects.

  4. Towards Effective Elicitation of NIN-AND Tree Causal Models

    NASA Astrophysics Data System (ADS)

    Xiang, Yang; Li, Yu; Zhu, Zoe Jingyu

    To specify a Bayes net (BN), a conditional probability table (CPT), often of an effect conditioned on its n causes, needs assessed for each node. It generally has the complexity exponential on n. Noisy-OR reduces the complexity to linear, but can only represent reinforcing causal interactions. The non-impeding noisy-AND (NIN-AND) tree is the first causal model that explicitly expresses reinforcement, undermining, and their mixture. It has linear complexity, but requires elicitation of a tree topology for types of causal interactions. We study their topology space and develop two novel techniques for more effective elicitation.

  5. Cell movement elicited by epidermal growth factor receptor requires kinase and autophosphorylation but is separable from mitogenesis

    PubMed Central

    1994-01-01

    The EGF receptor (EGFR) upon activation signals increased cell movement. However, the domains within the receptor, and the pathway which trigger movement are undefined. We expressed EGFR mutants at physiologic levels in receptor-devoid NR6 cells to investigate this biologic response. The receptors possessed kinase activity and underwent autophosphorylation as predicted by primary amino acid sequence. EGF-induced cell motility was assessed in vitro by excess migration into an acellular area and colony scatter in the presence of saturating concentrations of EGF. Wild-type (WT)-EGFR signaled increased motility. However, replacing the conserved lysine721 with methionine resulted in a kinase-inactive receptor which did not elicit movement. Removal of the entire terminus by truncation (c'973) also abrogated ligand-induced motility. Thus, we concentrated on the carboxy- terminal domains. EGF-induced movement was seen with a less-truncated mutant (c'1000) that contained a single autophosphorylated tyrosine (tyrosine992). Other mutants, c'991 and c'1000F992, in which this tyrosine was removed did not signal motility. Fusion mutants which presented other autophosphorylated tyrosine domains also exhibited EGF- induced movement. These findings suggested that the presence of both an autophosphorylated tyrosine signaling domain and the kinase activity are necessary for this biologic response. All kinase-positive mutants signaled cell proliferation but only those that contained autophosphorylatable tyrosines induced movement. The motility responses mediated by these EGFR were identical in the presence or absence of mitomycin-C, at a dose (0.5 micrograms/ml) which completely inhibited cell proliferation. On the other side, D-actinomycin (50 ng/ml) blocked EGF-induced motility but did not affect thymidine incorporation. Thus, EGF-induced mitogenesis and cell motility are mediated through different pathways. PMID:8106552

  6. [Synergism between aggregation mutants of Dictyostelium discoideum].

    PubMed

    Barra, J

    1977-02-21

    The cells of an aggregateless mutant of Dictyostelium discoïdeum, agip 235, can cooperate with other aggregateless or wild strains to form differentiated aggregates. A soluble mediator liberated by the coaggregating cells seems responsible for the development of agip 235. In most cases, the development of mutant agip 235 stops at the aggregation stage; however, its coaggregation with the mutant 518 results in cosporulation, with the production of viable spores of each genotype, effecting a phenotypic suppression of both mutations.

  7. Physiological analysis of the stringent response elicited in an extreme thermophilic bacterium, Thermus thermophilus.

    PubMed

    Kasai, Koji; Nishizawa, Tomoyasu; Takahashi, Kosaku; Hosaka, Takeshi; Aoki, Hiroyuki; Ochi, Kozo

    2006-10-01

    Guanosine tetraphosphate (ppGpp) is a key mediator of stringent control, an adaptive response of bacteria to amino acid starvation, and has thus been termed a bacterial alarmone. Previous X-ray crystallographic analysis has provided a structural basis for the transcriptional regulation of RNA polymerase activity by ppGpp in the thermophilic bacterium Thermus thermophilus. Here we investigated the physiological basis of the stringent response by comparing the changes in intracellular ppGpp levels and the rate of RNA synthesis in stringent (rel(+); wild type) and relaxed (relA and relC; mutant) strains of T. thermophilus. We found that in wild-type T. thermophilus, as in other bacteria, serine hydroxamate, an amino acid analogue that inhibits tRNA(Ser) aminoacylation, elicited a stringent response characterized in part by intracellular accumulation of ppGpp and that this response was completely blocked in a relA-null mutant and partially blocked in a relC mutant harboring a mutation in the ribosomal protein L11. Subsequent in vitro assays using ribosomes isolated from wild-type and relA and relC mutant strains confirmed that (p)ppGpp is synthesized by ribosomes and that mutation of RelA or L11 blocks that activity. This conclusion was further confirmed in vitro by demonstrating that thiostrepton or tetracycline inhibits (p)ppGpp synthesis. In an in vitro system, (p)ppGpp acted by inhibiting RNA polymerase-catalyzed 23S/5S rRNA gene transcription but at a concentration much higher than that of the observed intracellular ppGpp pool size. On the other hand, changes in the rRNA gene promoter activity tightly correlated with changes in the GTP but not ATP concentration. Also, (p)ppGpp exerted a potent inhibitory effect on IMP dehydrogenase activity. The present data thus complement the earlier structural analysis by providing physiological evidence that T. thermophilus does produce ppGpp in response to amino acid starvation in a ribosome-dependent (i.e., Rel

  8. Evaluation of a protease activation mutant of Sendai virus as a potent live vaccine.

    PubMed

    Maru, M; Haraguchi, M; Sato, K; Hotta, H; Homma, M

    1992-01-01

    A protease activation mutant of Sendai virus, TR-5, was investigated as a candidate for a live vaccine. Vaccination with TR-5 which had been activated by chymotrypsin beforehand (active TR-5) elicited protective immunity against otherwise lethal challenge infection with wild-type Sendai virus in DBA/2, C3H and ICR strains of mice. Less of the active TR-5 was required to confer protection on mice compared with an ordinary ether-inactivated Sendai virus vaccine (split vaccine). The protective immunity elicited by TR-5 lasted longer and the booster effect was more prominent compared to the split vaccine. No seroconversion was observed with contact mice when housed in a cage with mice vaccinated with the active TR-5. The overall results show that the active TR-5 is an effective and safe live vaccine of Sendai virus in mice.

  9. Identifying representative drug resistant mutants of HIV

    PubMed Central

    2015-01-01

    Background Drug resistance is one of the most important causes for failure of anti-AIDS treatment. During therapy, multiple mutations accumulate in the HIV genome, eventually rendering the drugs ineffective in blocking replication of the mutant virus. The huge number of possible mutants precludes experimental analysis to explore the molecular mechanisms of resistance and develop improved antiviral drugs. Results In order to solve this problem, we have developed a new algorithm to reveal the most representative mutants from the whole drug resistant mutant database based on our newly proposed unified protein sequence and 3D structure encoding method. Mean shift clustering and multiple regression analysis were applied on genotype-resistance data for mutants of HIV protease and reverse transcriptase. This approach successfully chooses less than 100 mutants with the highest resistance to each drug out of about 10K in the whole database. When considering high level resistance to multiple drugs, the numbers reduce to one or two representative mutants. Conclusion This approach for predicting the most representative mutants for each drug has major importance for experimental verification since the results provide a small number of representative sequences, which will be amenable for in vitro testing and characterization of the expressed mutant proteins. PMID:26678327

  10. Electrophysiological study of Drosophila rhodopsin mutants

    PubMed Central

    1986-01-01

    Electrophysiological investigations were carried out on several independently isolated mutants of the ninaE gene, which encodes opsin in R1-6 photoreceptors, and a mutant of the ninaD gene, which is probably important in the formation of the rhodopsin chromophore. In these mutants, the rhodopsin content in R1-6 photoreceptors is reduced by 10(2)-10(6)-fold. Light-induced bumps recorded from even the most severely affected mutants are physiologically normal. Moreover, a detailed noise analysis shows that photoreceptor responses of both a ninaE mutant and a ninaD mutant follow the adapting bump model. Since any extensive rhodopsin-rhodopsin interactions are not likely in these mutants, the above results suggest that such interactions are not needed for the generation and adaptation of light-induced bumps. Mutant bumps are strikingly larger in amplitude than wild-type bumps. This difference is observed both in ninaD and ninaE mutants, which suggests that it is due to severe depletion of rhodopsin content, rather than to any specific alterations in the opsin protein. Lowering or buffering the intracellular calcium concentration by EGTA injection mimics the effects of the mutations on the bump amplitude, but, unlike the mutations, it also affects the latency and kinetics of light responses. PMID:3097245

  11. Elicitation Support Requirements of Multi-Expertise Teams

    ERIC Educational Resources Information Center

    Bitter-Rijpkema, Marlies; Martens, Rob; Jochems, Wim

    2005-01-01

    Tools to support knowledge elicitation are used more and more in situations where employees or students collaborate using the computer. Studies indicate that differences exist between experts and novices regarding their methods of work and reasoning. However, the commonly preferred approach tends to deal with team members as a single system with…

  12. Elicited Production of Relative Clauses in Children with Williams Syndrome

    ERIC Educational Resources Information Center

    Zukowski, Andrea

    2009-01-01

    Relative clauses have been implicated alternately as a strength and a weakness in the language of people with Williams Syndrome (WS). To clarify the facts, an elicited production test was administered to 10 people with WS (age 10-16 years), 10 typically developing children (age 4-7 years), and 12 typically developing adults. Nearly every WS…

  13. NEURAL RESPONSES ELICITED BY ELECTRICAL STIMULATION OF THE RETINA

    PubMed Central

    Chen, Shih-Jen; Mahadevappa, Manjunatha; Roizenblatt, Roberto; Weiland, James; Humayun, Mark

    2006-01-01

    Purpose To study electrically elicited responses (EERs) that are produced by epiretinal stimulation of normal and degenerated retina. Methods Three biological models of retinal degeneration are compared: normal and rd1 mouse, normal and RCD1 dog, and human with retinitis pigmentosa. In mouse, epiretinal stimulation was accomplished by means of a wire inserted in the vitreous cavity, and single-unit activity was recorded in visual cortex. In dog and human, an implantable retinal stimulator was used to stimulate the retina, and evoked potentials were recorded from the cortical surface (dog) or scalp (human). Results Analysis of EERs revealed distinct early (less than 10 ms) and late (greater than 50 ms) responses. Synaptic blockers abolished the late response but not the early response. For eliciting the early response in normal and rd mice, a square pulse stimulus was more efficient than the sine wave or pulse train. In normal and degenerate canine retina, electrically elicited responses also exhibited early and late phases. EERs in a retinal prosthesis test subject (with retinitis pigmentosa) showed latency similar to the canine, but no evidence of an early response, possibly due to the lack of sensitivity in scalp (human) vs cortical surface (canine) electrode placement. Conclusion EERs could be elicited from both normal and degenerated retina. Mouse, dog, and human EERs showed common characteristics. PMID:17471346

  14. Creating a Framework: Art Therapy Elicits the Narrative

    ERIC Educational Resources Information Center

    Harber, Karen

    2011-01-01

    A case study illustrates how art therapy was used to elicit the narrative of an adolescent male student in transition from incarceration to a transfer school setting. Childhood trauma was addressed in individual sessions and within a literacy group co-led by a reading specialist. The art therapist responded to the client's needs by broadening the…

  15. Creating a Framework: Art Therapy Elicits the Narrative

    ERIC Educational Resources Information Center

    Harber, Karen

    2011-01-01

    A case study illustrates how art therapy was used to elicit the narrative of an adolescent male student in transition from incarceration to a transfer school setting. Childhood trauma was addressed in individual sessions and within a literacy group co-led by a reading specialist. The art therapist responded to the client's needs by broadening the…

  16. Clinicians as Communication Partners: Developing a Mediated Discourse Elicitation Protocol

    ERIC Educational Resources Information Center

    Hengst, Julie A.; Duff, Melissa C.

    2007-01-01

    This article presents the development and piloting of a mediated discourse elicitation protocol. Grounded in situated theories of communication and informed by mediated discourse analysis, this protocol selectively samples familiar discourse types in a manner designed to preserve interactional aspects of communication. Critically, the mediated…

  17. Eliciting Design Patterns for E-Learning Systems

    ERIC Educational Resources Information Center

    Retalis, Symeon; Georgiakakis, Petros; Dimitriadis, Yannis

    2006-01-01

    Design pattern creation, especially in the e-learning domain, is a highly complex process that has not been sufficiently studied and formalized. In this paper, we propose a systematic pattern development cycle, whose most important aspects focus on reverse engineering of existing systems in order to elicit features that are cross-validated through…

  18. Using Automatic Speech Recognition Technology with Elicited Oral Response Testing

    ERIC Educational Resources Information Center

    Cox, Troy L.; Davies, Randall S.

    2012-01-01

    This study examined the use of automatic speech recognition (ASR) scored elicited oral response (EOR) tests to assess the speaking ability of English language learners. It also examined the relationship between ASR-scored EOR and other language proficiency measures and the ability of the ASR to rate speakers without bias to gender or native…

  19. The Role of Elicited Verbal Imitation in Toddlers' Word Learning

    ERIC Educational Resources Information Center

    Hodges, Rosemary; Munro, Natalie; Baker, Elise; McGregor, Karla; Docking, Kimberley; Arciuli, Joanne

    2016-01-01

    This study is about the role of elicited verbal imitation in toddler word learning. Forty-eight toddlers were taught eight nonwords linked to referents. During training, they were asked to imitate the nonwords. Naming of the referents was tested at three intervals (one minute later [uncued], five minutes, and 1-7 days later [cued]) and recognition…

  20. Using Automatic Speech Recognition Technology with Elicited Oral Response Testing

    ERIC Educational Resources Information Center

    Cox, Troy L.; Davies, Randall S.

    2012-01-01

    This study examined the use of automatic speech recognition (ASR) scored elicited oral response (EOR) tests to assess the speaking ability of English language learners. It also examined the relationship between ASR-scored EOR and other language proficiency measures and the ability of the ASR to rate speakers without bias to gender or native…

  1. Preparing Beginning Teachers to Elicit and Interpret Students' Mathematical Thinking

    ERIC Educational Resources Information Center

    Sleep, Laurie; Boerst, Timothy A.

    2012-01-01

    This study investigated how teacher education assignments can be designed to support beginning teachers in learning to do the work of teaching. We examined beginners' formative assessment practices--in particular, their eliciting and interpreting of students' mathematical thinking--in the context of an elementary mathematics methods assignment,…

  2. Modification of commercially available simulators to elicit decision making behavior.

    PubMed

    Salud, Jonathan; Ononye, Chiagozie; Salud, Lawrence; Pugh, Carla

    2012-01-01

    In recent years, simulation training has emerged as an innovative method for decreasing error and teaching complex procedures. Simulation has also been a valuable tool for evaluating investigatory and analytic thinking. By adding a specific, clinically oriented modification to a commercially available simulator, we were able to elicit first-year emergency medicine resident perceptions, actions, and decisions.

  3. A Study of the Affective Responses Elicited by Occupational Stimuli

    ERIC Educational Resources Information Center

    Schoon, Craig G.

    1976-01-01

    The semantic differential was used to assess the properties of affect elicited by occupational stimuli. Vocationally committed men studying medicine, business, and engineering responded to a semantic differential containing occupational concepts. Results show a semantic space for all three groups composed of three orthogonal dimensions of affect…

  4. Transfer of Aversive Respondent Elicitation in Accordance with Equivalence Relations

    ERIC Educational Resources Information Center

    Valverde, Miguel Rodriguez; Luciano, Carmen; Barnes-Holmes, Dermot

    2009-01-01

    The present study investigates the transfer of aversively conditioned respondent elicitation through equivalence classes, using skin conductance as the measure of conditioning. The first experiment is an attempt to replicate Experiment 1 in Dougher, Augustson, Markham, Greenway, and Wulfert (1994), with different temporal parameters in the…

  5. Eliciting Production of L2 Target Structures through Priming Activities

    ERIC Educational Resources Information Center

    McDonough, Kim; Trofimovich, Pavel; Neumann, Heike

    2015-01-01

    This study focuses on the pedagogical applications of structural priming research in an English for academic purposes (EAP) context, investigating whether priming activities are an effective tool for eliciting production of target grammatical structures. University students across four EAP classes carried out a total of 6 information-exchange…

  6. Visual emotional context modulates brain potentials elicited by unattended tones.

    PubMed

    Sugimoto, Sayaka; Nittono, Hiroshi; Hori, Tadao

    2007-10-01

    To examine whether brain electrical responses to environmental stimuli were influenced by emotional contexts, event-related potentials (ERPs) elicited by nonstartle probe tones were recorded from 13 student volunteers while they were viewing emotionally positive, neutral, and negative slides of the International Affective Picture System. The auditory stimuli consisted of high-deviant (2000 Hz, p=.08), low-deviant (1050 Hz, p=.08), and standard (1000 Hz, p=.84) tones with a mean onset-to-onset interval of 600 ms. Participants were told to ignore the tones. High-deviant tones elicited a larger N1 (peaking around 100 ms) when participants were viewing negative slides than when viewing positive slides. The amplitude of the P2 elicited by standard tones (peaking around 170 ms) was smaller when participants were viewing positive slides than when viewing negative and neutral slides. The amplitude of the mismatch negativity (150-200 ms) tended to reduce during positive slide presentation, but this difference appeared to be due to reduction of the P2 elicited by standard tones. These findings suggest that visually induced emotional states have a sequential effect on auditory information processing, in that the influence of negative emotion appears at an earlier stage than that of positive emotion.

  7. Bacterial elicitation and evasion of plant innate immunity

    PubMed Central

    Abramovitch, Robert B.; Anderson, Jeffrey C.; Martin, Gregory B.

    2010-01-01

    Recent research on plant responses to bacterial attack has identified extracellular and intracellular host receptors that recognize conserved pathogen-associated molecular patterns and more specialized virulence proteins, respectively. These findings have shed light on our understanding of the molecular mechanisms by which bacteria elicit host defences and how pathogens have evolved to evade or suppress these defences. PMID:16936700

  8. Elicited Production of Relative Clauses in Children with Williams Syndrome

    ERIC Educational Resources Information Center

    Zukowski, Andrea

    2009-01-01

    Relative clauses have been implicated alternately as a strength and a weakness in the language of people with Williams Syndrome (WS). To clarify the facts, an elicited production test was administered to 10 people with WS (age 10-16 years), 10 typically developing children (age 4-7 years), and 12 typically developing adults. Nearly every WS…

  9. Intermediary's Information Seeking, Inquiring Minds, and Elicitation Styles.

    ERIC Educational Resources Information Center

    Wu, Mei-Mei; Liu, Ying-Hsang

    2003-01-01

    Explores how intermediaries seek information from patrons by analyzing intermediaries' elicitation utterances through three dimensions: linguistic forms, utterance purposes, and communicative functions. Reports on results of questionnaires given to patrons and intermediaries in academic and research libraries in Taiwan and investigates…

  10. Web-Based Elicitation Tasks in SLA Research.

    ERIC Educational Resources Information Center

    Ayoun, Dalila

    2000-01-01

    Studied second language acquisition (SLA) designed with Web-based elicitation tasks to obtain greater internal and external validity. Tested the acquisition of the properties subsumed under the verb movement parameter and the null subject parameter by English native speakers enrolled in college French. (Author/VWL)

  11. A Task that Elicits Reasoning: A Dual Analysis

    ERIC Educational Resources Information Center

    Yankelewitz, Dina; Mueller, Mary; Maher, Carolyn A.

    2010-01-01

    This paper reports on the forms of reasoning elicited as fourth grade students in a suburban district and sixth grade students in an urban district worked on similar tasks involving reasoning with the use of Cuisenaire rods. Analysis of the two data sets shows similarities in the reasoning used by both groups of students on specific tasks, and the…

  12. Photo-Elicitation Method Gives Voice and Reactions of Subjects.

    ERIC Educational Resources Information Center

    Smith, C. Zoe; Woodward, Anne-Marie

    1999-01-01

    Describes a research assignment (called "photo-elicitation") in a graduate course on the role of photography in society in which students interview people similar to the subjects in the photographs to discover how the photographs affect them. Includes material from one research project interviewing three recovering drug addicts responding to Larry…

  13. Transfer of Aversive Respondent Elicitation in Accordance with Equivalence Relations

    ERIC Educational Resources Information Center

    Valverde, Miguel Rodriguez; Luciano, Carmen; Barnes-Holmes, Dermot

    2009-01-01

    The present study investigates the transfer of aversively conditioned respondent elicitation through equivalence classes, using skin conductance as the measure of conditioning. The first experiment is an attempt to replicate Experiment 1 in Dougher, Augustson, Markham, Greenway, and Wulfert (1994), with different temporal parameters in the…

  14. A Study of the Affective Responses Elicited by Occupational Stimuli

    ERIC Educational Resources Information Center

    Schoon, Craig G.

    1976-01-01

    The semantic differential was used to assess the properties of affect elicited by occupational stimuli. Vocationally committed men studying medicine, business, and engineering responded to a semantic differential containing occupational concepts. Results show a semantic space for all three groups composed of three orthogonal dimensions of affect…

  15. Engaging Young Children in Research through Photo Elicitation

    ERIC Educational Resources Information Center

    Pyle, Angela

    2013-01-01

    Embracing the new sociology of childhood, this paper describes a participatory research method built on a belief in the competency of young children. The paper begins with a critical review of the photo elicitation literature exploring the varied levels of children's participation. Drawing on the strengths of the previous research, a multi-step…

  16. Pattern Visual Evoked Potentials Elicited by Organic Electroluminescence Screen

    PubMed Central

    Matsumoto, Celso Soiti; Shinoda, Kei; Matsumoto, Harue; Funada, Hideaki; Minoda, Haruka

    2014-01-01

    Purpose. To determine whether organic electroluminescence (OLED) screens can be used as visual stimulators to elicit pattern-reversal visual evoked potentials (p-VEPs). Method. Checkerboard patterns were generated on a conventional cathode-ray tube (S710, Compaq Computer Co., USA) screen and on an OLED (17 inches, 320 × 230 mm, PVM-1741, Sony, Tokyo, Japan) screen. The time course of the luminance changes of each monitor was measured with a photodiode. The p-VEPs elicited by these two screens were recorded from 15 eyes of 9 healthy volunteers (22.0 ± 0.8 years). Results. The OLED screen had a constant time delay from the onset of the trigger signal to the start of the luminescence change. The delay during the reversal phase from black to white for the pattern was 1.0 msec on the cathode-ray tube (CRT) screen and 0.5 msec on the OLED screen. No significant differences in the amplitudes of P100 and the implicit times of N75 and P100 were observed in the p-VEPs elicited by the CRT and the OLED screens. Conclusion. The OLED screen can be used as a visual stimulator to elicit p-VEPs; however the time delay and the specific properties in the luminance change must be taken into account. PMID:25197652

  17. Pattern visual evoked potentials elicited by organic electroluminescence screen.

    PubMed

    Matsumoto, Celso Soiti; Shinoda, Kei; Matsumoto, Harue; Funada, Hideaki; Sasaki, Kakeru; Minoda, Haruka; Iwata, Takeshi; Mizota, Atsushi

    2014-01-01

    To determine whether organic electroluminescence (OLED) screens can be used as visual stimulators to elicit pattern-reversal visual evoked potentials (p-VEPs). Checkerboard patterns were generated on a conventional cathode-ray tube (S710, Compaq Computer Co., USA) screen and on an OLED (17 inches, 320 × 230 mm, PVM-1741, Sony, Tokyo, Japan) screen. The time course of the luminance changes of each monitor was measured with a photodiode. The p-VEPs elicited by these two screens were recorded from 15 eyes of 9 healthy volunteers (22.0 ± 0.8 years). The OLED screen had a constant time delay from the onset of the trigger signal to the start of the luminescence change. The delay during the reversal phase from black to white for the pattern was 1.0 msec on the cathode-ray tube (CRT) screen and 0.5 msec on the OLED screen. No significant differences in the amplitudes of P100 and the implicit times of N75 and P100 were observed in the p-VEPs elicited by the CRT and the OLED screens. The OLED screen can be used as a visual stimulator to elicit p-VEPs; however the time delay and the specific properties in the luminance change must be taken into account.

  18. The Role of Elicited Verbal Imitation in Toddlers' Word Learning

    ERIC Educational Resources Information Center

    Hodges, Rosemary; Munro, Natalie; Baker, Elise; McGregor, Karla; Docking, Kimberley; Arciuli, Joanne

    2016-01-01

    This study is about the role of elicited verbal imitation in toddler word learning. Forty-eight toddlers were taught eight nonwords linked to referents. During training, they were asked to imitate the nonwords. Naming of the referents was tested at three intervals (one minute later [uncued], five minutes, and 1-7 days later [cued]) and recognition…

  19. Eliciting Production of L2 Target Structures through Priming Activities

    ERIC Educational Resources Information Center

    McDonough, Kim; Trofimovich, Pavel; Neumann, Heike

    2015-01-01

    This study focuses on the pedagogical applications of structural priming research in an English for academic purposes (EAP) context, investigating whether priming activities are an effective tool for eliciting production of target grammatical structures. University students across four EAP classes carried out a total of 6 information-exchange…

  20. Eliciting Students' Beliefs about Who Is Good at Mathematics

    ERIC Educational Resources Information Center

    Morge, Shelby P.

    2007-01-01

    This article highlights a series of activities designed to elicit students' mathematics-related beliefs, particularly those related to gender. As a result of the activities, females in upper-level classes rated themselves as having less confidence than males, and viewing a movie clip was sufficient for some students to modify their descriptions of…

  1. Photo-Elicitation Method Gives Voice and Reactions of Subjects.

    ERIC Educational Resources Information Center

    Smith, C. Zoe; Woodward, Anne-Marie

    1999-01-01

    Describes a research assignment (called "photo-elicitation") in a graduate course on the role of photography in society in which students interview people similar to the subjects in the photographs to discover how the photographs affect them. Includes material from one research project interviewing three recovering drug addicts responding to Larry…

  2. Elicitation Support Requirements of Multi-Expertise Teams

    ERIC Educational Resources Information Center

    Bitter-Rijpkema, Marlies; Martens, Rob; Jochems, Wim

    2005-01-01

    Tools to support knowledge elicitation are used more and more in situations where employees or students collaborate using the computer. Studies indicate that differences exist between experts and novices regarding their methods of work and reasoning. However, the commonly preferred approach tends to deal with team members as a single system with…

  3. Photo-Elicitation: Reflexivity on Method, Analysis, and Graphic Portraits

    ERIC Educational Resources Information Center

    Richard, Veronica M.; Lahman, Maria K. E.

    2015-01-01

    In this methodological discussion, the authors detail and reflect on the processes of using photo-elicitation interviewing as a way to align with positive qualitative methodologies, to gain access to participant beliefs and values, and to highlight participant voices through their choices of words and visuals. A review of the literature and an…

  4. Engaging Young Children in Research through Photo Elicitation

    ERIC Educational Resources Information Center

    Pyle, Angela

    2013-01-01

    Embracing the new sociology of childhood, this paper describes a participatory research method built on a belief in the competency of young children. The paper begins with a critical review of the photo elicitation literature exploring the varied levels of children's participation. Drawing on the strengths of the previous research, a multi-step…

  5. Eliciting Students' Beliefs about Who Is Good at Mathematics

    ERIC Educational Resources Information Center

    Morge, Shelby P.

    2007-01-01

    This article highlights a series of activities designed to elicit students' mathematics-related beliefs, particularly those related to gender. As a result of the activities, females in upper-level classes rated themselves as having less confidence than males, and viewing a movie clip was sufficient for some students to modify their descriptions of…

  6. Computational Support for Early Elicitation and Classification of Tone

    ERIC Educational Resources Information Center

    Bird, Steven; Lee, Haejoong

    2014-01-01

    Investigating a tone language involves careful transcription of tone on words and phrases. This is challenging when the phonological categories--the tones or melodies--have not been identified. Effects such as coarticulation, sandhi, and phrase-level prosody appear as obstacles to early elicitation and classification of tone. This article presents…

  7. Eliciting Student Views Using an Interview-About-Instances Technique.

    ERIC Educational Resources Information Center

    Gilbert, John K.; And Others

    An exposition is made of a method to elicit students' comprehension of the meaning of words commonly used in science, which may be influential in determining what they learn. The method's aim is to elucidate features in students' understanding of childrens' science (that found before formal teaching of science), student science (that found after…

  8. A Task that Elicits Reasoning: A Dual Analysis

    ERIC Educational Resources Information Center

    Yankelewitz, Dina; Mueller, Mary; Maher, Carolyn A.

    2010-01-01

    This paper reports on the forms of reasoning elicited as fourth grade students in a suburban district and sixth grade students in an urban district worked on similar tasks involving reasoning with the use of Cuisenaire rods. Analysis of the two data sets shows similarities in the reasoning used by both groups of students on specific tasks, and the…

  9. Computational Support for Early Elicitation and Classification of Tone

    ERIC Educational Resources Information Center

    Bird, Steven; Lee, Haejoong

    2014-01-01

    Investigating a tone language involves careful transcription of tone on words and phrases. This is challenging when the phonological categories--the tones or melodies--have not been identified. Effects such as coarticulation, sandhi, and phrase-level prosody appear as obstacles to early elicitation and classification of tone. This article presents…

  10. Mutant calreticulin requires both its mutant C-terminus and the thrombopoietin receptor for oncogenic transformation

    PubMed Central

    Elf, Shannon; Abdelfattah, Nouran S.; Chen, Edwin; Perales-Patón, Javier; Rosen, Emily A.; Ko, Amy; Peisker, Fabian; Florescu, Natalie; Giannini, Silvia; Wolach, Ofir; Morgan, Elizabeth A.; Tothova, Zuzana; Losman, Julie-Aurore; Schneider, Rebekka K.; Al-Shahrour, Fatima; Mullally, Ann

    2016-01-01

    Somatic mutations in calreticulin (CALR) are present in approximately 40% of patients with myeloproliferative neoplasms (MPN) but the mechanism by which mutant CALR is oncogenic remains unclear. Here, we demonstrate that expression of mutant CALR alone is sufficient to engender MPN in mice and recapitulates the disease phenotype of CALR-mutant MPN patients. We further show that the thrombopoietin receptor, MPL is required for mutant CALR-driven transformation through JAK-STAT pathway activation, thus rendering mutant CALR-transformed hematopoietic cells sensitive to JAK2 inhibition. Finally, we demonstrate that the oncogenicity of mutant CALR is dependent on the positive electrostatic charge of the C-terminus of the mutant protein, which is necessary for physical interaction between mutant CALR and MPL. Together, our findings elucidate a novel paradigm of cancer pathogenesis and reveal how CALR mutations induce MPN. PMID:26951227

  11. Enhancers of Conidiation Mutants in Aspergillus Nidulans

    PubMed Central

    Gems, D. H.; Clutterbuck, A. J.

    1994-01-01

    Mutants at a number of loci, designated sthenyo, have been isolated as enhancers of the oligoconidial mutations at the medA locus. Two loci have been mapped: sthA on linkage group I, and sthB on linkage group V. Two probable alleles have been identified at each locus but two further mutants were unlinked to either sthA or sthB. Neither sthA nor sthB mutants have conspicuous effects on morphology on their own, nor could the sthA1 sthB2 double mutant be distinguished from wild type. Mutants at both loci also interact with the temperature-sensitive brlA42 mutant at the permissive temperature to give a phenotype described as ``Abacoid.'' sthA1 also induces a slight modification of the phenotype of an abaA mutant. We conclude that sthenyo genes act mainly at the phialide stage of conidiation. We also describe the isolation of new medA mutants arising spontaneously as outgrowths on brlA42 colonies. PMID:8056325

  12. Regulation of Mutant p53 Protein Expression.

    PubMed

    Vijayakumaran, Reshma; Tan, Kah Hin; Miranda, Panimaya Jeffreena; Haupt, Sue; Haupt, Ygal

    2015-01-01

    For several decades, p53 has been detected in cancer biopsies by virtue of its high protein expression level which is considered indicative of mutation. Surprisingly, however, mouse genetic studies revealed that mutant p53 is inherently labile, similar to its wild type (wt) counterpart. Consistently, in response to stress conditions, both wt and mutant p53 accumulate in cells. While wt p53 returns to basal level following recovery from stress, mutant p53 remains stable. In part, this can be explained in mutant p53-expressing cells by the lack of an auto-regulatory loop with Mdm2 and other negative regulators, which are pivotal for wt p53 regulation. Further, additional protective mechanisms are acquired by mutant p53, largely mediated by the co-chaperones and their paralogs, the stress-induced heat shock proteins. Consequently, mutant p53 is accumulated in cancer cells in response to chronic stress and this accumulation is critical for its oncogenic gain of functions (GOF). Building on the extensive knowledge regarding wt p53, the regulation of mutant p53 is unraveling. In this review, we describe the current understanding on the major levels at which mutant p53 is regulated. These include the regulation of p53 protein levels by microRNA and by enzymes controlling p53 proteasomal degradation.

  13. Eyespot-assembly mutants in Chlamydomonas reinhardtii.

    PubMed Central

    Lamb, M R; Dutcher, S K; Worley, C K; Dieckmann, C L

    1999-01-01

    Chlamydomonas reinhardtii is a single-celled green alga that phototaxes toward light by means of a light-sensitive organelle, the eyespot. The eyespot is composed of photoreceptor and Ca(++)-channel signal transduction components in the plasma membrane of the cell and reflective carotenoid pigment layers in an underlying region of the large chloroplast. To identify components important for the positioning and assembly of a functional eyespot, a large collection of nonphototactic mutants was screened for those with aberrant pigment spots. Four loci were identified. eye2 and eye3 mutants have no pigmented eyespots. min1 mutants have smaller than wild-type eyespots. mlt1(ptx4) mutants have multiple eyespots. The MIN1, MLT1(PTX4), and EYE2 loci are closely linked to each other; EYE3 is unlinked to the other three loci. The eye2 and eye3 mutants are epistatic to min1 and mlt1 mutations; all double mutants are eyeless. min1 mlt1 double mutants have a synthetic phenotype; they are eyeless or have very small, misplaced eyespots. Ultrastructural studies revealed that the min1 mutants are defective in the physical connection between the plasma membrane and the chloroplast envelope membranes in the region of the pigment granules. Characterization of these four loci will provide a beginning for the understanding of eyespot assembly and localization in the cell. PMID:10511552

  14. A halotolerant mutant of Saccharomyces cerevisiae.

    PubMed Central

    Gaxiola, R; Corona, M; Zinker, S

    1996-01-01

    FRD, a nuclear and dominant spontaneous mutant of Saccharomyces cerevisiae capable of growing in up to 2 M NaCl, was isolated. Compared with parental cells, the mutant cells have a lower intracellular Na+/K+ ratio, shorter generation times in the presence of 1 M NaCl, and alterations in gene expression. PMID:8631691

  15. Saint Louis Encephalitis Temperature-Sensitive Mutants.

    DTIC Science & Technology

    1979-09-01

    Several mutants have been used in pairwise crosses to determine complementation Accessionl For VTIS G!RA& DTIC T %B 3 fl!, -r,. AD) Av ’Di [ Annual...Ghendon (1973) indicate that a large number of polio virus ts mutants producing a pathologic change in infected monkeys were assayed for virus produccion

  16. A Meningococcal NOMV-FHbp Vaccine for Africa Elicits Broader Serum Bactericidal Antibody Responses Against Serogroup B and non-B Strains than a Licensed Serogroup B Vaccine

    PubMed Central

    Pajon, Rolando; Lujan, Eduardo; Granoff, Dan M.

    2016-01-01

    Background Meningococcal epidemics in Sub-Sahara caused by serogroup A strains are controlled by a group A polysaccharide conjugate vaccine. Strains with serogroups C, W and X continue to cause epidemics. Protein antigens in licensed serogroup B vaccines are shared among serogroup B and non-B strains. Purpose Compare serum bactericidal antibody responses elicited by an investigational native outer membrane vesicle vaccine with over-expressed Factor H binding protein (NOMV-FHbp) and a licensed serogroup B vaccine (MenB-4C) against African serogroup A, B, C, W and X strains. Methods Human Factor H (FH) transgenic mice were immunized with NOMV-FHbp prepared from a mutant African meningococcal strain containing genetically attenuated endotoxin and a mutant sub-family B FHbp antigen with low FH binding, or with MenB-4C, which contains a recombinant sub-family B FHbp antigen that binds human FH, and three other antigens, NHba, NadA and PorA P1.4, capable of eliciting bactericidal antibody. Results The NOMV-FHbp elicited serum bactericidal activity against 12 of 13 serogroup A, B, W or X strains from Africa, and four isogenic serogroup B mutants with subfamily B FHbp sequence variants. There was no activity against a serogroup B mutant with sub-family A FHbp, or two serogroup C isolates from a recent outbreak in Northern Nigeria, which were mismatched for both PorA and sub-family of the FHbp vaccine antigen. For MenB-4C, NHba was expressed by all 16 African isolates tested, FHbp sub-family B in 13, and NadA in five. However, MenB-4C elicited titers ≥1:10 against only one isolate, and against only two of four serogroup B mutant strains with sub-family B FHbp sequence variants. Conclusions NOMV-FHbp has greater potential to confer serogroup-independent protection in Africa than the licensed MenB-4C vaccine. However, the NOMV-FHbp vaccine will require inclusion of sub-family A FHbp for coverage against recent serogroup C strains causing outbreaks in Northern Nigeria. PMID

  17. Immunogenic response induced by wzm and wzt gene deletion mutants from Brucella abortus S19.

    PubMed

    Wang, Xiu-Ran; Yan, Guang-Mou; Zhang, Rui; Lang, Xu-Long; Yang, Yan-Ling; Li, Xiao-Yan; Chen, Si; Qian, Jing; Wang, Xing-Long

    2014-02-01

    Brucellosis is an infectious disease affecting humans and animals worldwide. Effective methods of control include inducing immunity in animals by vaccination and elimination. Brucella abortus S19 is one of the popular vaccines for control of cattle brucellosis, as it has low virulence. In this paper, allelic exchange plasmids of wzm and wzt genes were constructed and partially knocked out to evaluate the effects on the induction of immunity to Brucella abortus S19 mutants. Cytokine secretion in vitro, INF-γ induction in vivo and antibody dynamics were evaluated. These data suggested that the immunity-eliciting ability of the wzm and wzt gene deletion mutants was similar, although reduced compared with the S19 strain. The results demonstrated that the wzt gene may be more important in the regulation of the induction of immunity than the wzm gene.

  18. Methane monooxygenase component B mutants alter the kinetics of steps throughout the catalytic cycle.

    PubMed

    Wallar, B J; Lipscomb, J D

    2001-02-20

    Component interactions play important roles in the regulation of catalysis by methane monooxygenase (MMO). The binding of component B (MMOB) to the hydroxylase component (MMOH) has been shown in previous studies to cause structural changes in MMOH that result in altered thermodynamic and kinetic properties during the reduction and oxygen binding steps of the catalytic cycle. Here, specific amino acid residues of MMOB that play important roles in the interconversion of several intermediates of the MMO cycle have been identified. Both of the histidine residues in Methylosinus trichosporium OB3b MMOB (H5 and H33) were chemically modified by diethylpyrocarbonate (DEPC). Although the DEPC--MMOB species exhibited only minor changes relative to unmodified MMOB in steady-state MMO turnover, large decreases in the formation rate constants of the reaction cycle intermediates, compound P and compound Q, were observed. The site specific mutants H5A, H33A, and H5A/H33A were made and characterized. H5A and wild type MMOB elicited similar steady-state and transient kinetics, although the mutant caused a slightly lower rate constant for Q formation. Conversely, H33A exhibited a >50-fold decrease in the P formation rate constant, which resulted in slower formation of Q. The kinetics of the double mutant (H5A/H33A) were similar to those of H33A, suggesting that the highly conserved residue, H33, has the most significant effect on the efficient progress of the cycle. Ongoing NMR investigations of residues perturbed by formation of the MMOH-MMOB complex suggested construction of the MMOB N107G/S109A/S110A/T111A quadruple mutant. This mutant was found to elicit a nearly 2-fold increase in specific activity for steady-state MMO turnover of large substrates such as furan and nitrobenzene but caused no similar increase for the physiological substrate, methane. While the quadruple mutant did not have a significant effect on P and Q formation, it caused an almost 3-fold increase in the

  19. Radiation-sensitive mutants of Arabidopsis thaliana

    SciTech Connect

    Jenkins, M.E.; Harlow, G.R.; Liu, Z.

    1995-06-01

    Five Arabidopsis mutants have been isolated on the basis of hypersensitivity of leaf tissue to UV light. For each mutant, the UV-hypersensitive phenotype (uvh) was inherited as a single recessive Mendelian trait. In addition, each uvh mutant represented a separate complementation group. Three of the mutations producing the UV hypersensitive phenotype have been mapped relative to either genetic markers or physical microsatellite polymorphisms. Locus UVH1 is linked to nga76 on chromosome 5, UVH3 to GL1 on chromosome three, and UVH6 to nga59 on chromosome 1. Each uvh mutant has a characteristic pattern of sensitivity based on UV sensitivity of leaf tissue, UV sensitivity of root tissue, and ionizing radiation sensitivity of seeds. On the basis of these patterns, possible molecular defects in these mutants are discussed. 30 refs., 3 figs., 5 tabs.

  20. crl mutants of Saccharomyces cerevisiae resemble both mutants affecting general control of amino acid biosynthesis and omnipotent translational suppressor mutants.

    PubMed

    McCusker, J H; Haber, J E

    1988-06-01

    Cyocloheximide resistant lethal (crl) mutants of Saccharomyces cerevisiae, defining 22 unlinked complementation groups, are unable to grow at 37 degrees. They are also highly pleiotropic at their permissive temperature of 25 degrees. The mutants are all unable to arrest at the G1 stage of the cell cycle when grown to stationary phase or when starved for a single amino acid, though they do arrest at G1 when deprived of all nitrogen. The crl mutants are also hypersensitive to various amino acid analogs and to 3-aminotriazole. These mutants also "tighten" leaky auxotrophic mutations that permit wild-type cells to grow in the absence of the appropriate amino acid. All of these phenotypes are also exhibited by gcn mutants affecting general control of amino acid biosynthesis. In addition, the crl mutants are all hypersensitive to hygromycin B, an aminoglycoside antibiotic that stimulates translational misreading. The crl mutations also suppress one nonsense mutation which is phenotypically suppressed by hygromycin B. Many crl mutants are also osmotically sensitive. These are phenotypes which the crl mutations have in common with previously isolated omnipotent suppressors. We suggest that the the crl mutations all affect the fidelity of protein translation.

  1. Nonlinear Analyses of Elicited Modal, Raised, and Pressed Rabbit Phonation

    PubMed Central

    Awan, Shaheen N.; Novaleski, Carolyn K.; Rousseau, Bernard

    2014-01-01

    Objectives/Hypothesis The purpose of this study was to use nonlinear dynamic analysis methods such as phase space portraits and correlation dimension (D2) as well as descriptive spectrographic analyses to characterize acoustic signals produced during evoked rabbit phonation. Methods Seventeen New Zealand white breeder rabbits were used to perform the study. A Grass S-88 stimulator (SA Instrumentation, Encinitas, CA) and constant current isolation unit (Grass Telefactor, model PSIU6; West Warwick, RI) were used to provide electrical stimulation to laryngeal musculature, and transglottal airflow rate and stimulation current (mA) were manipulated to elicit modal, raised intensity, and pressed phonations. Central 1 second portions of the most stable portion of the acoustic waveform for modal, raised intensity, and pressed phonations were edited, and then analyzed via phase space portraits, Poincaré sections, and the estimation of the correlation dimension (D2). In an attempt to limit the effects of the highly variable and nonstationary characteristics of some of the signals being analyzed, D2 analysis was also performed on the most stable central 200 ms portion of the acoustic waveform. Descriptive analysis of each phonation was also conducted using sound spectrograms. Results Results showed that the complexity of phonation and the subsequent acoustic waveform is increased as transglottal airflow rate and degree of glottal adduction is manipulated in the evoked rabbit phonation model. In particular, phonatory complexity, as quantified via correlation dimension analyses and demonstrated via spectrographic characteristics, increases from “modal” (i.e., phonation elicited at just above the phonation threshold pressure) to raised intensity (phonation elicited by increasing transglottal airflow rate) to pressed (phonation elicited by increasing the stimulation current delivered to the larynx). Variations in a single dynamic dimension (airflow rate or adductory force

  2. Bactericidal antibody responses elicited by a meningococcal outer membrane vesicle vaccine with overexpressed factor H-binding protein and genetically attenuated endotoxin.

    PubMed

    Koeberling, Oliver; Seubert, Anja; Granoff, Dan M

    2008-07-15

    Outer membrane vesicle (OMV) vaccines from mutant Neisseria meningitidis strains engineered to overexpress factor H-binding protein (fHbp) have elicited broadly protective serum antibody responses in mice. The vaccines investigated were not treated with detergents to avoid extracting fHbp, which is a lipoprotein. Because of their high endotoxin content, the vaccines would not be safe to administer to humans. We prepared a native OMV vaccine from a strain engineered to overexpress fHbp and in which the gene encoding LpxL1 was inactivated, which reportedly decreases endotoxin activity. The OMV vaccine from the mutant had a similar or lower ability to induce the expression of proinflammatory cytokines by human peripheral blood mononuclear cells, compared with a detergent-extracted wild-type OMV, and 1000-10,000-fold lower activity than a native wild-type OMV. In mice, the OMV vaccine from the mutant elicited higher serum bactericidal antibody responses to a panel of heterologous N. meningitidis strains than did a control multicomponent recombinant protein vaccine or a detergent-extracted OMV vaccine that has been demonstrated to confer protection against meningococcal disease in humans. The data illustrate the potential to develop a broadly immunogenic native OMV vaccine that has decreased endotoxin activity and is potentially suitable for testing in humans.

  3. Estrogens Suppress a Behavioral Phenotype in Zebrafish Mutants of the Autism Risk Gene, CNTNAP2

    PubMed Central

    Hoffman, Ellen J.; Turner, Katherine J.; Fernandez, Joseph M.; Cifuentes, Daniel; Ghosh, Marcus; Ijaz, Sundas; Jain, Roshan A.; Kubo, Fumi; Bill, Brent R.; Baier, Herwig; Granato, Michael; Barresi, Michael J. F.; Wilson, Stephen W.; Rihel, Jason; State, Matthew W.; Giraldez, Antonio J.

    2016-01-01

    Summary Autism spectrum disorders (ASD) are a group of devastating neurodevelopmental syndromes that affect up to 1 in 68 children. Despite advances in the identification of ASD risk genes, the mechanisms underlying ASD remain unknown. Homozygous loss-of-function mutations in Contactin Associated Protein-like 2 (CNTNAP2) are strongly linked to ASD. Here we investigate the function of Cntnap2 and undertake pharmacological screens to identify phenotypic suppressors. We find that zebrafish cntnap2 mutants display GABAergic deficits particularly in the forebrain and sensitivity to drug-induced seizures. High-throughput behavioral profiling identifies nighttime hyperactivity in cntnap2 mutants, while pharmacological testing reveals dysregulation of GABAergic and glutamatergic systems. Finally, we find that estrogen receptor agonists elicit a behavioral fingerprint anti-correlative to that of cntnap2 mutants and show that the phytoestrogen biochanin A specifically reverses the mutant behavioral phenotype. These results identify estrogenic compounds as phenotypic suppressors and illuminate novel pharmacological pathways with relevance to autism. PMID:26833134

  4. Estrogens Suppress a Behavioral Phenotype in Zebrafish Mutants of the Autism Risk Gene, CNTNAP2.

    PubMed

    Hoffman, Ellen J; Turner, Katherine J; Fernandez, Joseph M; Cifuentes, Daniel; Ghosh, Marcus; Ijaz, Sundas; Jain, Roshan A; Kubo, Fumi; Bill, Brent R; Baier, Herwig; Granato, Michael; Barresi, Michael J F; Wilson, Stephen W; Rihel, Jason; State, Matthew W; Giraldez, Antonio J

    2016-02-17

    Autism spectrum disorders (ASDs) are a group of devastating neurodevelopmental syndromes that affect up to 1 in 68 children. Despite advances in the identification of ASD risk genes, the mechanisms underlying ASDs remain unknown. Homozygous loss-of-function mutations in Contactin Associated Protein-like 2 (CNTNAP2) are strongly linked to ASDs. Here we investigate the function of Cntnap2 and undertake pharmacological screens to identify phenotypic suppressors. We find that zebrafish cntnap2 mutants display GABAergic deficits, particularly in the forebrain, and sensitivity to drug-induced seizures. High-throughput behavioral profiling identifies nighttime hyperactivity in cntnap2 mutants, while pharmacological testing reveals dysregulation of GABAergic and glutamatergic systems. Finally, we find that estrogen receptor agonists elicit a behavioral fingerprint anti-correlative to that of cntnap2 mutants and show that the phytoestrogen biochanin A specifically reverses the mutant behavioral phenotype. These results identify estrogenic compounds as phenotypic suppressors and illuminate novel pharmacological pathways with relevance to autism. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Differential growth characteristics and immunogenicity of tight and coasting temperature-sensitive mutants of Pseudomonas aeruginosa.

    PubMed Central

    Morris Hooke, A; Sordelli, D O; Cerquetti, M C; Bellanti, J A

    1987-01-01

    Genetically attenuated vaccines capable of limited replication in the vaccinate may elicit stronger, longer-lasting immunity than that induced by component, killed whole-cell, or nonreplicating live vaccines. We have isolated and partially characterized temperature-sensitive Pseudomonas aeruginosa mutants of two different phenotypes: a tight mutant, which ceases all growth immediately after its transfer to 36 degrees C, and a coaster, which continues to replicate for five generations at 36 degrees C. The growth profiles of the two temperature-sensitive phenotypes were compared both in vitro and in vivo; maintenance of the coasting phenotype in vivo was confirmed. The immunogenicity of the two phenotypes was compared in two models. In model 1, ICR mice were immunized intraperitoneally (i.p.) with graded doses of either mutant and challenged 3 weeks later i.p. with lethal doses of the wild-type strain. In model 2, DBA/2J mice were immunized intranasally with either mutant and subsequently challenged with an aerosolized inoculum of the wild-type strain, and lung clearance was measured over 4 h. In both models, the coaster demonstrated slightly higher immunogenic potential and, in addition, induced significantly higher levels of immunotype-specific serum immunoglobulin G after i.p. immunization. PMID:3098688

  6. Unpredicted phenotypes of two mutants of the TcR DMF5.

    PubMed

    Tadesse, Fitsum G; Mensali, Nadia; Fallang, Lars-Egil; Walseng, Even; Yang, Weiwen; Olweus, Johanna; Wälchli, Sébastien

    2015-10-01

    When a T-cell Receptor (TcR) interacts with its cognate peptide-MHC (pMHC), it triggers activation of a signaling cascade that results in the elicitation of a T cell effector function. Different models have been proposed to understand which parameters are needed to obtain an optimal activation of the signaling. It was speculated that improving the binding of a TcR could bring a stronger pMHC recognition, hence a stronger stimulation of the T cell. However, it was recently shown that an increase in affinity does not seem to be sufficient to guarantee improved functionality. A combination of factors is necessary to place the modified TcR in an optimal functional window. We here compared the binding parameters of two mutants of the melanoma antigen peptide MART-127-35 specific TcR DMF5. The first mutant was previously isolated by others in a screen for improved TcR. It was reported to have an increased CD8-independent activity. We confirmed these data and showed that the enhancement was neither due to change in half life (t1/2) nor Kd of the pMHC-TcR complex. The second mutant was designed based on a previous report claiming that a particular polymorphic residue in the TRAV12-2 chain was stabilizing the TcR. We created a DMF5 mutant for this residue and showed that, unexpectedly, this TcR had acquired a reduced overall activity although the TcR-pMHC complex was more stable when compared to the TcR wild type complex (increased t1/2). In addition, the soluble TcR form of this mutant bound target cells less efficiently. From this we concluded that kinetic parameters do not always predict the superior functionality of mutant TcRs.

  7. A two-strain mixture of rhizobacteria elicits induction of systemic resistance against Pseudomonas syringae and Cucumber mosaic virus coupled to promotion of plant growth on Arabidopsis thaliana.

    PubMed

    Ryu, Choong-Min; Murphy, John F; Reddy, M S; Kloepper, Joseph W

    2007-02-01

    We evaluated a commercial biopreparation of plant growth-promoting rhizobacteria (PGPR) strains Bacillus subtilis GB03 and B. amyloliquefaciens IN937a formulated with the carrier chitosan (BioYield) for its capacity to elicit growth promotion and induced systemic resistance against infection by Cucumber Mosaic Virus (CMV) and Pseudomonas syringae pv. tomato DC3000 in Arabidopsis thaliana. The biopreparation promoted plant growth of Arabidopsis hormonal mutants, which included auxin, gibberellic acid, ethylene, jasmonate, salicylic acid, and brassinosteroid insensitive lines as well as each wild-type. The biopreparation protected plants against CMV based on disease severity in wild-type plants. However, virus titre was not lower in control plants and those treated with biopreparation, suggesting that the biopreparation induced tolerance rather than resistance against CMV. Interestingly, the biopreparation induced resistance against CMV in NahG plants, as evidenced by both reduced disease severity and virus titer. The biopreparation also elicited induced resistance against P. syringae pv. tomato in the wild-type but not in NahG transgenic plants, which degrade endogenous salicylic acid, indicating the involvement of salicylic acid signaling. Our results indicate that some PGPR strains can elicit plant growth promotion by mechanisms that are different from known hormonal signaling pathways. In addition, the mechanism for elicitation of induced resistance by PGPR may be pathogen-dependent. Collectively, the two-Bacilli strain mixture can be utilized as a biological inoculant for both protection of plant against bacterial and viral pathogens and enhancement of plant growth.

  8. Emotional scenes and facial expressions elicit different psychophysiological responses.

    PubMed

    Alpers, Georg W; Adolph, Dirk; Pauli, Paul

    2011-06-01

    We examined if emotional faces elicit physiological responses similar to pictures of emotional scenes. Forty one students viewed emotional scenes (negative, neutral, and positive) and emotional faces (angry, neutral, and happy). Heart rate, orbicularis oculi and electrodermal activity were measured continuously, and the startle reflex was elicited. Although the patterns of valence and arousal ratings were comparable, physiological response patterns differed. For scenes we replicated the valence-specific modulation of the startle response, heart rate deceleration, and the arousal-related modulation of the electrodermal response. In contrast, for faces we found valence-specific modulation only for the electrodermal response, but the startle and heart rate deceleration were modulated by arousal. Although arousal differences may account for some differences in physiological responding this shows that not all emotional material that is decoded similarly leads to the same psychophysiological output. 2011 Elsevier B.V. All rights reserved.

  9. Simplified Expert Elicitation Procedure for Risk Assessment of Operating Events

    SciTech Connect

    Ronald L. Boring; David Gertman; Jeffrey Joe; Julie Marble; William Galyean; Larry Blackwood; Harold Blackman

    2005-06-01

    This report describes a simplified, tractable, and usable procedure within the US Nuclear Regulator Commission (NRC) for seeking expert opinion and judgment. The NRC has increased efforts to document the reliability and risk of nuclear power plants (NPPs) through Probabilistic Risk Assessment (PRA) and Human Reliability Analysis (HRA) models. The Significance Determination Process (SDP) and Accident Sequence Precursor (ASP) programs at the NRC utilize expert judgment on the probability of failure, human error, and the operability of equipment in cases where otherwise insufficient operational data exist to make meaningful estimates. In the past, the SDP and ASP programs informally sought the opinion of experts inside and outside the NRC. This document represents a formal, documented procedure to take the place of informal expert elicitation. The procedures outlined in this report follow existing formal expert elicitation methodologies, but are streamlined as appropriate to the degree of accuracy required and the schedule for producing SDP and ASP analyses.

  10. Expert elicitation for a national-level volcano hazard model

    NASA Astrophysics Data System (ADS)

    Bebbington, Mark; Stirling, Mark; Cronin, Shane; Wang, Ting; Jolly, Gill

    2016-04-01

    The quantification of volcanic hazard at national level is a vital pre-requisite to placing volcanic risk on a platform that permits meaningful comparison with other hazards such as earthquakes. New Zealand has up to a dozen dangerous volcanoes, with the usual mixed degrees of knowledge concerning their temporal and spatial eruptive history. Information on the 'size' of the eruptions, be it in terms of VEI, volume or duration, is sketchy at best. These limitations and the need for a uniform approach lend themselves to a subjective hazard analysis via expert elicitation. Approximately 20 New Zealand volcanologists provided estimates for the size of the next eruption from each volcano and, conditional on this, its location, timing and duration. Opinions were likewise elicited from a control group of statisticians, seismologists and (geo)chemists, all of whom had at least heard the term 'volcano'. The opinions were combined via the Cooke classical method. We will report on the preliminary results from the exercise.

  11. Conditioned craving cues elicit an automatic approach tendency.

    PubMed

    Van Gucht, Dinska; Vansteenwegen, Debora; Van den Bergh, Omer; Beckers, Tom

    2008-10-01

    In two experiments, we used a Pavlovian differential conditioning procedure to induce craving for chocolate. As a result of repeated pairing with chocolate intake, initially neutral cues came to elicit an automatic approach tendency in a speeded stimulus-response compatibility reaction time task. This automatic approach tendency, moreover, seemed to be sensitive to manipulations of extinction and renewal in the Pavlovian conditioning procedure. These findings corroborate and extend previous reports of automatic approach tendencies elicited by substance-relevant cues in addiction, while controlling for alternative accounts for such observations. Moreover, our data lend support to and extend learning models of cue-induced craving and addiction. Finally, we argue that the procedure we present here provides an ecologically valid behavioural tool that allows studying processes involved in cue-induced craving, addiction and relapse without relying on verbal report.

  12. Voltage transients elicited by sudden step-up of auxin

    NASA Technical Reports Server (NTRS)

    Pickard, B. G.

    1984-01-01

    It is hypothesized (i) that the molecular mechanism for the reception of friction and flexure and the mechanism by which auxin enhances ethylene production have in common a release of free calcium into the cytosol, (ii) that elevated cytosolic calcium initiates vesicle exocytosis, and (iii) that the vesicles release a factor or set of factors which depolarizes the plasmalemma and promotes ethylene synthesis. One consequence of such exocytosis should be small, extracellularly observable voltage transients. Transients, ranging in size up to 600 microvolts and possessing risetimes (10-90%) of approximately 200 ms, are known to be elicited in etiolated stems of Pisum sativum L. by friction and are here shown to be elicited by sudden increase of auxin concentration and also by a Ca2+ ionophore.

  13. Elicitation of specific syntactic structures in primary progressive aphasia.

    PubMed

    Deleon, Jessica; Gesierich, Benno; Besbris, Max; Ogar, Jennifer; Henry, Maya L; Miller, Bruce L; Gorno-Tempini, Maria Luisa; Wilson, Stephen M

    2012-12-01

    Many patients with primary progressive aphasia (PPA) are impaired in syntactic production. Because most previous studies of expressive syntax in PPA have relied on quantitative analysis of connected speech samples, which is a relatively unconstrained task, it is not well understood which specific syntactic structures are most challenging for these patients. We used an elicited syntactic production task to identify which syntactic structures pose difficulties for 31 patients with three variants of PPA: non-fluent/agrammatic, semantic and logopenic. Neurodegenerative and healthy age-matched participants were included as controls. As expected, non-fluent/agrammatic patients made the most syntactic errors. The structures that resulted in the most errors were constructions involving third person singular present agreement, and constructions involving embedded clauses. Deficits on this elicited production task were associated with atrophy of the left posterior inferior frontal gyrus.

  14. Eliciting probabilistic expectations: Collaborations between psychologists and economists

    PubMed Central

    Bruine de Bruin, Wändi

    2017-01-01

    We describe two collaborations in which psychologists and economists provided essential support on foundational projects in major research programs. One project involved eliciting adolescents’ expectations regarding significant future life events affecting their psychological and economic development. The second project involved eliciting consumers’ expectations regarding inflation, a potentially vital input to their investment, saving, and purchasing decisions. In each project, we sought questions with the precision needed for economic modeling and the simplicity needed for lay respondents. We identify four conditions that, we believe, promoted our ability to sustain these transdisciplinary collaborations and coproduce the research: (i) having a shared research goal, which neither discipline could achieve on its own; (ii) finding common ground in shared methodology, which met each discipline’s essential evidentiary conditions, but without insisting on its culturally acquired tastes; (iii) sharing the effort throughout, with common language and sense of ownership; and (iv) gaining mutual benefit from both the research process and its products. PMID:28270610

  15. Modified repetition in poems elicited from young children.

    PubMed

    Dowker, A D

    1991-10-01

    Attempts were made to elicit poems from 133 children between the ages of 2;3 and 6;11. Seventy-eight of the children produced 606 poems between them. Forty-five per cent of the poems contained the syntactic device of modified repetition: a substitution exercise where a grammatical frame is repeated and the substitution occurs in part of the grammatical frame. This was so despite the fact that modified repetition was not present in the examples that were used to elicit poems from the children. The frequency and types of modified repetition used by the children did not vary much with age. The question of whether children's use of modified repetition in their rhythmical poems has the function of helping them to practise grammatical forms, or whether it is simply one reflection of a general human tendency towards the use of pattern in language, is discussed.

  16. Elicitation of Diacetylenic Compounds in Suspension Cultured Cells of Eggplant

    PubMed Central

    Imoto, Setsuko; Ohta, Yoshimoto

    1988-01-01

    Induction of stress metabolites in the suspension cultured cells of eggplant (Solanum melongena L.) was examined. When autoclaved RNase A or nigeran, both of which are nonspecific phytoalexin elicitors in bean cells, were added to the cell culture of eggplant, greatly enhanced levels of three compounds were observed. One of them was cis-pentadeca-6-ene-1,3-diyne-5,15-diol, a novel diacetylenic compound. This compound has considerable fungitoxic activity. Also identified was falcarindiol, another fungitoxic diacetylenic compound previously reported as one of the phytoalexins in infected tomato fruits and leaves. Elicited compounds preferentially accumulated in the culture medium rather than in the cells and decreased to original levels during prolonged culturing. The elicitation of these compounds was closely correlated with cellular damage in terms of the decrease of growth rate and was inhibited by 10 micromolar cycloheximide. PMID:16665862

  17. The Frame Constraint on Experimentally Elicited Speech Errors in Japanese.

    PubMed

    Saito, Akie; Inoue, Tomoyoshi

    2017-06-01

    The so-called syllable position effect in speech errors has been interpreted as reflecting constraints posed by the frame structure of a given language, which is separately operating from linguistic content during speech production. The effect refers to the phenomenon that when a speech error occurs, replaced and replacing sounds tend to be in the same position within a syllable or word. Most of the evidence for the effect comes from analyses of naturally occurring speech errors in Indo-European languages, and there are few studies examining the effect in experimentally elicited speech errors and in other languages. This study examined whether experimentally elicited sound errors in Japanese exhibits the syllable position effect. In Japanese, the sub-syllabic unit known as "mora" is considered to be a basic sound unit in production. Results showed that the syllable position effect occurred in mora errors, suggesting that the frame constrains the ordering of sounds during speech production.

  18. Endonuclease IV (nfo) mutant of Escherichia coli.

    PubMed Central

    Cunningham, R P; Saporito, S M; Spitzer, S G; Weiss, B

    1986-01-01

    A cloned gene, designated nfo, caused overproduction of an EDTA-resistant endonuclease specific for apurinic-apyrimidinic sites in DNA. The sedimentation coefficient of the enzyme was similar to that of endonuclease IV. An insertion mutation was constructed in vitro and transferred from a plasmid to the Escherichia coli chromosome. nfo mutants had an increased sensitivity to the alkylating agents methyl methanesulfonate and mitomycin C and to the oxidants tert-butyl hydroperoxide and bleomycin. The nfo mutation enhanced the killing of xth (exonuclease III) mutants by methyl methanesulfonate, H2O2, tert-butyl hydroperoxide, and gamma rays, and it enhanced their mutability by methyl methanesulfonate. It also increased the temperature sensitivity of an xth dut (dUTPase) mutant that is defective in the repair of uracil-containing DNA. These results are consistent with earlier findings that endonuclease IV and exonuclease III both cleave DNA 5' to an apurinic-apyrimidinic site and that exonuclease III is more active. However, nfo mutants were more sensitive to tert-butyl hydroperoxide and to bleomycin than were xth mutants, suggesting that endonuclease IV might recognize some lesions that exonuclease III does not. The mutants displayed no marked increase in sensitivity to 254-nm UV radiation, and the addition of an nth (endonuclease III) mutation to nfo or nfo xth mutants did not significantly increase their sensitivity to any of the agents tested. Images PMID:2430946

  19. AMORE; The Advanced Multimedia Organizer for Requirements Elicitation

    DTIC Science & Technology

    1993-06-01

    forth. Because large-scale systems may contain many thousands of requirements, it is necessary to provide some type of structural principles for...AMORE, it provides the tools necessary to: •Capture and preserve knowledge about the requirements elicitation process. • Teach useful skills that the...Tutor was based upon the principles of traditional instructional design and the orga- nization of lessons with prerequisite skills and objectives. A

  20. A Step-Wise Approach to Elicit Triangular Distributions

    NASA Technical Reports Server (NTRS)

    Greenberg, Marc W.

    2013-01-01

    Adapt/combine known methods to demonstrate an expert judgment elicitation process that: 1.Models expert's inputs as a triangular distribution, 2.Incorporates techniques to account for expert bias and 3.Is structured in a way to help justify expert's inputs. This paper will show one way of "extracting" expert opinion for estimating purposes. Nevertheless, as with most subjective methods, there are many ways to do this.

  1. Saturated Zone Flow and Transport Expert Elicitation Project

    SciTech Connect

    Coppersmith, Kevin J.; Perman, Roseanne C.

    1998-01-01

    This report presents results of the Saturated Zone Flow and Transport Expert Elicitation (SZEE) project for Yucca Mountain, Nevada. This project was sponsored by the US Department of Energy (DOE) and managed by Geomatrix Consultants, Inc. (Geomatrix), for TRW Environmental Safety Systems, Inc. The DOE's Yucca Mountain Site Characterization Project (referred to as the YMP) is intended to evaluate the suitability of the site for construction of a mined geologic repository for the permanent disposal of spent nuclear fuel and high-level radioactive waste. The SZEE project is one of several that involve the elicitation of experts to characterize the knowledge and uncertainties regarding key inputs to the Yucca Mountain Total System Performance Assessment (TSPA). The objective of the current project was to characterize the uncertainties associated with certain key issues related to the saturated zone system in the Yucca Mountain area and downgradient region. An understanding of saturated zone processes is critical to evaluating the performance of the potential high-level nuclear waste repository at Yucca Mountain. A major goal of the project was to capture the uncertainties involved in assessing the saturated flow processes, including uncertainty in both the models used to represent the physical processes controlling saturated zone flow and transport, and the parameter values used in the models. So that the analysis included a wide range of perspectives, multiple individual judgments were elicited from members of an expert panel. The panel members, who were experts from within and outside the Yucca Mountain project, represented a range of experience and expertise. A deliberate process was followed in facilitating interactions among the experts, in training them to express their uncertainties, and in eliciting their interpretations. The resulting assessments and probability distributions, therefore, provide a reasonable aggregate representation of the knowledge and

  2. Shared bimanual tasks elicit bimanual reflexes during movement.

    PubMed

    Mutha, Pratik K; Sainburg, Robert L

    2009-12-01

    Previous research has suggested distinct predictive and reactive control mechanisms for bimanual movements compared with unimanual motion. Recent studies have extended these findings by demonstrating that movement corrections during bimanual movements might differ depending on whether or not the task is shared between the arms. We hypothesized that corrective responses during shared bimanual tasks recruit bilateral rapid feedback mechanisms such as reflexes. We tested this hypothesis by perturbing one arm as subjects performed uni- and bimanual movements. Movements were made in a virtual-reality environment in which hand position was displayed as a cursor on a screen. During bimanual motion, we provided cursor feedback either independently for each arm (independent-cursor) or such that one cursor was placed at the average location between the arms (shared-cursor). On random trials, we applied a 40 N force pulse to the right arm 100 ms after movement onset. Our results show that while reflex responses were rapidly elicited in the perturbed arm, electromyographic activity remained close to baseline levels in the unperturbed arm during the independent-cursor trials. In contrast, when the cursor was shared between the arms, reflex responses were reduced in the perturbed arm and were rapidly elicited in the unperturbed arm. Our results thus suggest that when both arms contribute to achieving the task goal, reflex responses are bilaterally elicited in response to unilateral perturbations. These results agree with and extend recent suggestions that bimanual feedback control might be modified depending on task context.

  3. Elicited versus emitted behavior: Time to abandon the distinction.

    PubMed

    Domjan, Michael

    2016-03-01

    The concept of emitted behavior was formulated as a part of the original argument for the validity of a new kind of learning called operant conditioning. The rationale for operant conditioning contrasted it with Pavlovian or classical conditioning, which was (and remains) fundamentally based on responses to conditioned and unconditioned stimuli. Classical conditioned responses were said to be elicited. In contrast, operant behavior was viewed as emitted and controlled primarily by response consequences rather than antecedents. I argue that the distinction between emitted and elicited behavior is no longer warranted for three major reasons. First, the distinction was based on a view of Pavlovian conditioning that is no longer viable. Second, the distinction is incompatible with both empirical data and contemporary conceptualizations of operant behavior. Third, the only way to overcome these problems is to define emitted and elicited in terms of the type of conditioning (operant and classical) that produces these behaviors, but that approach makes the definitions circular and does not avoid implications of the terms that are misleading and counterproductive in light of contemporary research and thinking.

  4. Conditioned cues for smoking elicit preparatory responses in healthy smokers

    PubMed Central

    Winkler, Markus H.; Weyers, Peter; Mucha, Ronald F.; Stippekohl, Bastian; Stark, Rudolf

    2010-01-01

    Rationale Smoking cues are theorized to be conditioned stimuli (CSs) formed by repeated pairing with drug. Smoking paraphernalia can elicit subjective and physiological responses in smokers, indicative of positive affect and motivation to consume. Although these responses are probably the result of conditioning, direct evidence from human conditioning studies with physiological measures of motivational valence is rare. Objective The present study investigated the motivational properties of experimentally conditioned cues for smoking. Methods Thirty-nine smokers completed a differential conditioning protocol. Abstract pictures were used as CSs and single puffs on a cigarette as unconditioned stimulus (US). Skin conductance responses and facial electromyography of the zygomatic, corrugator, and orbicularis oris muscles were measured during conditioning. Results The conditioned cue for smoking (CS+) elicited stronger skin conductance responses and more activity of the zygomatic and orbicularis oris muscles than the CS−. Conclusions These results support the notion that through pairing with smoking, neutral stimuli acquire the ability to elicit preparatory physiological responses, which are assumed to play an important role in the maintenance of addiction and relapse in the natural environment. PMID:20953588

  5. Nicotine Elicits Convulsive Seizures by Activating Amygdalar Neurons

    PubMed Central

    Iha, Higor A.; Kunisawa, Naofumi; Shimizu, Saki; Tokudome, Kentaro; Mukai, Takahiro; Kinboshi, Masato; Ikeda, Akio; Ito, Hidefumi; Serikawa, Tadao; Ohno, Yukihiro

    2017-01-01

    Nicotinic acetylcholine (nACh) receptors are implicated in the pathogenesis of epileptic disorders; however, the mechanisms of nACh receptors in seizure generation remain unknown. Here, we performed behavioral and immunohistochemical studies in mice and rats to clarify the mechanisms underlying nicotine-induced seizures. Treatment of animals with nicotine (1–4 mg/kg, i.p.) produced motor excitement in a dose-dependent manner and elicited convulsive seizures at 3 and 4 mg/kg. The nicotine-induced seizures were abolished by a subtype non-selective nACh antagonist, mecamylamine (MEC). An α7 nACh antagonist, methyllycaconitine, also significantly inhibited nicotine-induced seizures whereas an α4β2 nACh antagonist, dihydro-β-erythroidine, affected only weakly. Topographical analysis of Fos protein expression, a biological marker of neural excitation, revealed that a convulsive dose (4 mg/kg) of nicotine region-specifically activated neurons in the piriform cortex, amygdala, medial habenula, paratenial thalamus, anterior hypothalamus and solitary nucleus among 48 brain regions examined, and this was also suppressed by MEC. In addition, electric lesioning of the amygdala, but not the piriform cortex, medial habenula and thalamus, specifically inhibited nicotine-induced seizures. Furthermore, microinjection of nicotine (100 and 300 μg/side) into the amygdala elicited convulsive seizures in a dose-related manner. The present results suggest that nicotine elicits convulsive seizures by activating amygdalar neurons mainly via α7 nACh receptors. PMID:28232801

  6. Elicitation of andrographolide in the suspension cultures of Andrographis paniculata.

    PubMed

    Gandi, Suryakala; Rao, Kiranmayee; Chodisetti, Bhuvaneswari; Giri, Archana

    2012-12-01

    Andrographis paniculata belonging to the family Acanthaceae produces a group of diterpene lactones, one of which is the pharmaceutically important-andrographolide. It is known to possess various important biological properties like anticancer, anti-HIV, anti-inflammatory, etc. This is the first report on the production of andrographolide in the cell suspension cultures of Andrographis paniculata by 'elicitation'. Elicitation was attempted to enhance the andrographolide content in the suspension cultures of Andrographis paniculata and also to ascertain its stimulation under stress conditions or in response to pathogen attack. The maximum andrographolide production was found to be 1.53 mg/g dry cell weight (DCW) at the end of stationary phase during the growth curve. The biotic elicitors (yeast, Escherichia coli, Bacillus subtilis, Agrobacterium rhizogenes 532 and Agrobacterium tumefaciens C 58) were more effective in eliciting the response when compared to the abiotic elicitors (CdCl(2), AgNO(3), CuCl(2) and HgCl(2)). Yeast has shown to stimulate maximum accumulation of 13.5 mg/g DCW andrographolide, which was found to be 8.82-fold higher than the untreated cultures.

  7. Physiological responses induced by emotion-eliciting films.

    PubMed

    Fernández, Cristina; Pascual, Juan C; Soler, Joaquim; Elices, Matilde; Portella, Maria J; Fernández-Abascal, Enrique

    2012-06-01

    Emotion-eliciting films are commonly used to evoke subjective emotional responses in experimental settings. The main aim of the present study was to investigate whether a set of film clips with discrete emotions were capable to elicit measurable objective physiological responses. The convergence between subjective and objective measures was evaluated. Finally, the effect of gender on emotional responses was investigated. A sample of 123 subjects participated in the study. Individuals were asked to view a set of emotional film clips capable to induce seven emotions: anger, fear, sadness, disgust, amusement, tenderness and neutral state. Skin conductance level (SCL), heart rate (HR) and subjective emotional responses were measured for each film clip. In comparison with neutral films, SCL was significantly increased after viewing fear films, and HR was also significantly incremented for anger and fear films. Physiological variations were associated with arousal measures indicating a convergence between subjective and objective reactions. Women appeared to display significantly greater SCL and HR responses for films inducing sadness. The findings suggest that physiological activation would be more easily induced by emotion-eliciting films that tap into emotions with higher subjective arousal such as anger and fear.

  8. Elicitation of macrophages from the peritoneal cavity of channel catfish

    USGS Publications Warehouse

    Jenkins, J.A.; Klesius, P.H.

    1998-01-01

    Four chemicals were evaluated for elicitation of macrophages in peritoneal cavities of 250-300g healthy channel catfish Ictalurus punctatus. Cellular exudates were collected at 3, 5, 7, 10, 14, and 20 d following intraperitoneal injections with squalene, Freund's incomplete adjuvant (FIA), goat serum, thioglycollate, or as a control, phosphate-buffered saline. Injection with either squalene or FIA induced significantly greater (P ??? 0.0001) macrophage recruitment than the other chemicals. The effectiveness of squalene and FIA was compared further by macrophage collection daily for 7 d. Squalene and FIA elicited similarly high macrophage responses (P ??? 0.0450), the highest being 3.43 x 106 macrophages/mL (SE, 2.4 x l06) at 99% purity at day 2 and 2.1 X 106 macrophages/mL (SE, 0.7 x 106) at day 14 at 80% purity, respectively. In both experiments, the time after injection was not statistically significant, nor was there an interaction between time and chemicals. The occurrence of cells other than macrophages decreased with time to yield macrophage recoveries of 47-99% for squalene and 30-80% for FIA. Two subsets of macrophages were observed by means of flow cytometry. As demonstrated by chemiluminescence, the squalene-elicited cells produced high-energy oxygen compounds important to the phagocytic process.

  9. Generation of a Live Attenuated Influenza Vaccine that Elicits Broad Protection in Mice and Ferrets.

    PubMed

    Wang, Lulan; Liu, Su-Yang; Chen, Hsiang-Wen; Xu, Juan; Chapon, Maxime; Zhang, Tao; Zhou, Fan; Wang, Yao E; Quanquin, Natalie; Wang, Guiqin; Tian, Xiaoli; He, Zhanlong; Liu, Longding; Yu, Wenhai; Sanchez, David Jesse; Liang, Yuying; Jiang, Taijiao; Modlin, Robert; Bloom, Barry R; Li, Qihan; Deng, Jane C; Zhou, Paul; Qin, F Xiao-Feng; Cheng, Genhong

    2017-03-08

    New influenza vaccines that provide effective and broad protection are desperately needed. Live attenuated viruses are attractive vaccine candidates because they can elicit both humoral and cellular immune responses. However, recent formulations of live attenuated influenza vaccines (LAIVs) have not been protective. We combined high-coverage transposon mutagenesis of influenza virus with a rapid high-throughput screening for attenuation to generate W7-791, a live attenuated mutant virus strain. W7-791 produced only a transient asymptomatic infection in adult and neonatal mice even at doses 100-fold higher than the LD50 of the parent strain. A single administration of W7-791 conferred full protection to mice against lethal challenge with H1N1, H3N2, and H5N1 strains, and improved viral clearance in ferrets. Adoptive transfer of T cells from W7-791-immunized mice conferred heterologous protection, indicating a role for T cell-mediated immunity. These studies present an LAIV development strategy to rapidly generate and screen entire libraries of viral clones.

  10. Drought stress modulates oxylipin signature by eliciting 12-OPDA as a potent regulator of stomatal aperture.

    PubMed

    Savchenko, Tatyana; Dehesh, Katayoon

    2014-01-01

    Through evolution, plants have developed a myriad of strategies to adapt to environmental perturbations. Using 3 Arabidopsis ecotypes in conjunction with various transgenic and mutant lines, we provide evidence that wounding and drought differentially alter the metabolic signatures derived from the 2 main competing oxylipin-pathway branches, namely the JA and its precursor 12-OPDA produced by Allene oxide synthase (AOS) branch, and aldehydes and corresponding alcohols generated by Hydroperoxide lyase (HPL) branch. Specifically, we show that wounding induces production of both HPL and AOS-derived metabolites whereas, drought stress only elicits production of hexenal but suppresses hexenol, and further uncouples the conversion of 12-OPDA to JA. This finding led to uncovering of 12-OPDA as a functional convergence point of oxylipin and ABA pathways to control stomatal aperture in plant adaptive responses to drought. In addition, using transgenic lines overexpressing plastidial and extraplastidial HPL enzyme establish the strong interdependence of AOS- and HPL-branch pathways, and the importance of this linkage in tailoring plant adaptive responses to the nature of perturbations.

  11. Magnaporthe oryzae-Secreted Protein MSP1 Induces Cell Death and Elicits Defense Responses in Rice.

    PubMed

    Wang, Yiming; Wu, Jingni; Kim, Sang Gon; Tsuda, Kenichi; Gupta, Ravi; Park, Sook-Young; Kim, Sun Tae; Kang, Kyu Young

    2016-04-01

    The Magnaporthe oryzae snodprot1 homolog (MSP1), secreted by M. oryzae, is a cerato-platanin family protein. msp1-knockout mutants have reduced virulence on barley leaves, indicating that MSP1 is required for the pathogenicity of rice blast fungus. To investigate the functional roles of MSP1 and its downstream signaling in rice, recombinant MSP1 was produced in Escherichia coli and was assayed for its functionality. Application of MSP1 triggered cell death and elicited defense responses in rice. MSP1 also induced H2O2 production and autophagic cell death in both suspension-cultured cells and rice leaves. One or more protein kinases triggered cell death, jasmonic acid and abscisic acid enhanced cell death, while salicylic acid suppressed it. We demonstrated that the secretion of MSP1 into the apoplast is a prerequisite for triggering cell death and activating defense-related gene expression. Furthermore, pretreatment of rice with a sublethal MSP1 concentration potentiated resistance to the pathogen. Taken together, our results showed that MSP1 induces a high degree of cell death in plants, which might be essential for its virulence. Moreover, rice can recognize MSP1, resulting in the induction of pathogen-associated molecular pattern-triggered immunity.

  12. Ciguatoxins activate specific cold pain pathways to elicit burning pain from cooling

    PubMed Central

    Vetter, Irina; Touska, Filip; Hess, Andreas; Hinsbey, Rachel; Sattler, Simon; Lampert, Angelika; Sergejeva, Marina; Sharov, Anastasia; Collins, Lindon S; Eberhardt, Mirjam; Engel, Matthias; Cabot, Peter J; Wood, John N; Vlachová, Viktorie; Reeh, Peter W; Lewis, Richard J; Zimmermann, Katharina

    2012-01-01

    Ciguatoxins are sodium channel activator toxins that cause ciguatera, the most common form of ichthyosarcotoxism, which presents with peripheral sensory disturbances, including the pathognomonic symptom of cold allodynia which is characterized by intense stabbing and burning pain in response to mild cooling. We show that intraplantar injection of P-CTX-1 elicits cold allodynia in mice by targeting specific unmyelinated and myelinated primary sensory neurons. These include both tetrodotoxin-resistant, TRPA1-expressing peptidergic C-fibres and tetrodotoxin-sensitive A-fibres. P-CTX-1 does not directly open heterologously expressed TRPA1, but when co-expressed with Nav channels, sodium channel activation by P-CTX-1 is sufficient to drive TRPA1-dependent calcium influx that is responsible for the development of cold allodynia, as evidenced by a large reduction of excitatory effect of P-CTX-1 on TRPA1-deficient nociceptive C-fibres and of ciguatoxin-induced cold allodynia in TRPA1-null mutant mice. Functional MRI studies revealed that ciguatoxin-induced cold allodynia enhanced the BOLD (Blood Oxygenation Level Dependent) signal, an effect that was blunted in TRPA1-deficient mice, confirming an important role for TRPA1 in the pathogenesis of cold allodynia. PMID:22850668

  13. Ciguatoxins activate specific cold pain pathways to elicit burning pain from cooling.

    PubMed

    Vetter, Irina; Touska, Filip; Hess, Andreas; Hinsbey, Rachel; Sattler, Simon; Lampert, Angelika; Sergejeva, Marina; Sharov, Anastasia; Collins, Lindon S; Eberhardt, Mirjam; Engel, Matthias; Cabot, Peter J; Wood, John N; Vlachová, Viktorie; Reeh, Peter W; Lewis, Richard J; Zimmermann, Katharina

    2012-10-03

    Ciguatoxins are sodium channel activator toxins that cause ciguatera, the most common form of ichthyosarcotoxism, which presents with peripheral sensory disturbances, including the pathognomonic symptom of cold allodynia which is characterized by intense stabbing and burning pain in response to mild cooling. We show that intraplantar injection of P-CTX-1 elicits cold allodynia in mice by targeting specific unmyelinated and myelinated primary sensory neurons. These include both tetrodotoxin-resistant, TRPA1-expressing peptidergic C-fibres and tetrodotoxin-sensitive A-fibres. P-CTX-1 does not directly open heterologously expressed TRPA1, but when co-expressed with Na(v) channels, sodium channel activation by P-CTX-1 is sufficient to drive TRPA1-dependent calcium influx that is responsible for the development of cold allodynia, as evidenced by a large reduction of excitatory effect of P-CTX-1 on TRPA1-deficient nociceptive C-fibres and of ciguatoxin-induced cold allodynia in TRPA1-null mutant mice. Functional MRI studies revealed that ciguatoxin-induced cold allodynia enhanced the BOLD (Blood Oxygenation Level Dependent) signal, an effect that was blunted in TRPA1-deficient mice, confirming an important role for TRPA1 in the pathogenesis of cold allodynia.

  14. Immunization with heat-killed Francisella tularensis LVS elicits protective antibody-mediated immunity.

    PubMed

    Lavine, Christy L; Clinton, Shawn R; Angelova-Fischer, Irena; Marion, Tony N; Bina, Xiaowen R; Bina, James E; Whitt, Michael A; Miller, Mark A

    2007-11-01

    Francisella tularensis (FT) has been classified by the CDC as a category A pathogen because of its high virulence and the high mortality rate associated with infection via the aerosol route. Because there is no licensed vaccine available for FT, development of prophylactic and therapeutic regimens for the prevention/treatment of infection is a high priority. In this report, heat-killed FT live vaccine strain (HKLVS) was employed as a vaccine immunogen, either alone or in combination with an adjuvant, and was found to elicit protective immunity against high-dose FT live vaccine strain (FTLVS) challenge. FT-specific antibodies produced in response to immunization with HKLVS alone were subsequently found to completely protect naive mice against high-dose FT challenge in both infection-interference and passive immunization experiments. Additional passive immunization trials employing serum collected from mice immunized with a heat-killed preparation of an O-antigen-deficient transposon mutant of FTLVS (HKLVS-OAg(neg)) yielded similar results. These findings demonstrated that FT-specific antibodies alone can confer immunity against high-dose FTLVS challenge, and they reveal that antibody-mediated protection is not dependent upon production of LPS-specific antibodies.

  15. Salmonella typhimurium mutants lacking NAD pyrophosphatase.

    PubMed Central

    Park, U E; Roth, J R; Olivera, B M

    1988-01-01

    NAD can serve as both a purine and a pyridine source for Salmonella typhimurium. Exogenous NAD is rapidly broken down into nicotinamide mononucleotide and AMP by an NAD pyrophosphatase, the first step in the pathway for the assimilation of exogenous NAD. We isolated and characterized mutants of S. typhimurium lacking NAD pyrophosphatase activity; such mutants were identified by their failure to use exogenous NAD as a purine source. These mutants carry mutations that map at a new locus, designated pnuE, between 86 and 87 min on the Salmonella chromosome. PMID:2841298

  16. Stem rust spores elicit rapid RPG1 phosphorylation

    USDA-ARS?s Scientific Manuscript database

    Stem rust threatens cereal production worldwide. Understanding the mechanism by which durable resistance genes, such as Rpg1, function is critical. We show that the RPG1 protein is phosphorylated within 5 min by exposure to spores from avirulent but not virulent races of stem rust. Transgenic mutant...

  17. Proteomic Analysis of Exosomes from Mutant KRAS Colon Cancer Cells Identifies Intercellular Transfer of Mutant KRAS*

    PubMed Central

    Demory Beckler, Michelle; Higginbotham, James N.; Franklin, Jeffrey L.; Ham, Amy-Joan; Halvey, Patrick J.; Imasuen, Imade E.; Whitwell, Corbin; Li, Ming; Liebler, Daniel C.; Coffey, Robert J.

    2013-01-01

    Activating mutations in KRAS occur in 30% to 40% of colorectal cancers. How mutant KRAS alters cancer cell behavior has been studied intensively, but non-cell autonomous effects of mutant KRAS are less understood. We recently reported that exosomes isolated from mutant KRAS-expressing colon cancer cells enhanced the invasiveness of recipient cells relative to exosomes purified from wild-type KRAS-expressing cells, leading us to hypothesize mutant KRAS might affect neighboring and distant cells by regulating exosome composition and behavior. Herein, we show the results of a comprehensive proteomic analysis of exosomes from parental DLD-1 cells that contain both wild-type and G13D mutant KRAS alleles and isogenically matched derivative cell lines, DKO-1 (mutant KRAS allele only) and DKs-8 (wild-type KRAS allele only). Mutant KRAS status dramatically affects the composition of the exosome proteome. Exosomes from mutant KRAS cells contain many tumor-promoting proteins, including KRAS, EGFR, SRC family kinases, and integrins. DKs-8 cells internalize DKO-1 exosomes, and, notably, DKO-1 exosomes transfer mutant KRAS to DKs-8 cells, leading to enhanced three-dimensional growth of these wild-type KRAS-expressing non-transformed cells. These results have important implications for non-cell autonomous effects of mutant KRAS, such as field effect and tumor progression. PMID:23161513

  18. Yeast mutants auxotrophic for choline or ethanolamine.

    PubMed Central

    Atkinson, K D; Jensen, B; Kolat, A I; Storm, E M; Henry, S A; Fogel, S

    1980-01-01

    Three mutants of the yeast Saccharomyces cerevisiae which require exogenous ethanolamine or choline were isolated. The mutants map to a single locus (cho1) on chromosome V. The lipid composition suggests that cho1 mutants do not synthesize phosphatidylserine under any growth conditions. If phosphatidylethanolamine or phosphatidylcholine, which are usually derived from phosphatidylserine, were synthesized from exogenous ethanolamine or choline, the mutants grew and divided relatively normally. However, mitochondrial abnormalities were evident even when ethanolamine and choline were supplied. Diploids homozygous for the cho1 mutation were defective in sporulation. Growth on nonfermentable carbon sources was slow, and a high proportion of respiratory-deficient (petite) cells were generated in cho1 cultures. PMID:6988386

  19. Characterization of rag1 mutant zebrafish leukocytes

    PubMed Central

    Petrie-Hanson, Lora; Hohn, Claudia; Hanson, Larry

    2009-01-01

    Background Zebrafish may prove to be one of the best vertebrate models for innate immunology. These fish have sophisticated immune components, yet rely heavily on innate immune mechanisms. Thus, the development and characterization of mutant and/or knock out zebrafish are critical to help define immune cell and immune gene functions in the zebrafish model. The use of Severe Combined Immunodeficient (SCID) and recombination activation gene 1 and 2 mutant mice has allowed the investigation of the specific contribution of innate defenses in many infectious diseases. Similar zebrafish mutants are now being used in biomedical and fish immunology related research. This report describes the leukocyte populations in a unique model, recombination activation gene 1-/- mutant zebrafish (rag1 mutants). Results Differential counts of peripheral blood leukocytes (PBL) showed that rag1 mutants had significantly decreased lymphocyte-like cell populations (34.7%) compared to wild-types (70.5%), and significantly increased granulocyte populations (52.7%) compared to wild-types (17.6%). Monocyte/macrophage populations were similar between mutants and wild-types, 12.6% and 11.3%, respectively. Differential leukocyte counts of rag1 mutant kidney hematopoietic tissue showed a significantly reduced lymphocyte-like cell population (8%), a significantly increased myelomonocyte population (57%), 34.8% precursor cells, and 0.2% thrombocytes, while wild-type hematopoietic kidney tissue showed 29.4% lymphocytes/lymphocyte-like cells, 36.4% myelomonocytes, 33.8% precursors and 0.5% thrombocytes. Flow cytometric analyses of kidney hematopoietic tissue revealed three leukocyte populations. Population A was monocytes and granulocytes and comprised 34.7% of the gated cells in rag1 mutants and 17.6% in wild-types. Population B consisted of hematopoietic precursors, and comprised 50% of the gated cells for rag1 mutants and 53% for wild-types. Population C consisted of lymphocytes and lymphocyte

  20. Muscle development in mdx mutant mice.

    PubMed

    Dangain, J; Vrbova, G

    1984-01-01

    Mechanical and contractile properties of tibialis anterior (TA) muscles from X-linked muscular dystrophic (mdx) mutant mice at different stages of development are compared to those of muscles from normal control animals. There is no difference between the tension output, speeds of contraction and relaxation, and weight of TA muscles from mutant adults and normal control animals. However, it is found that in 3-4-week-old mutant animals, tension output and muscle weight are very much reduced, and half relaxation time is prolonged. Thus, during this stage of development, muscles from mdx mice do not function properly. Histological examination of these muscles provides further evidence that, in these animals, rapid muscle destruction occurs at a particular time of development and that it is followed by complete recovery. This new mutant therefore presents an interesting case of muscle destruction and rapid regeneration. However, it is not an adequate model for Duchenne muscular dystrophy.

  1. Characteristics of Agrobacterium tumefaciens auxotrophic mutant infectivity.

    PubMed

    Lippincott, B B; Lippincott, J A

    1966-10-01

    Lippincott, Barbara B. (Northwestern University, Evanston, Ill.), and James A. Lippincott. Characteristics of Agrobacterium tumefaciens auxotrophic mutant infectivity. J. Bacteriol. 92:937-945. 166.-Mutants of Agrobacterium tumefaciens auxotrophic for adenine, methionine, or asparagine are less infectious than the wild-type strain B6 from which they were derived and show increased infectivity on pinto bean leaves when the specific compounds required for growth of the mutants are added to the infected leaf. Reversion to a prototrophic form of nutrition is accompanied by increased infectivity. Tumors initiated by these auxotrophic mutants are shown to arise only at large wound sites where nutritional conditions may be less restricting. The data indicate that, after inoculation, the bacteria pass through a phase in which host-supplied nutrients are utilized for the production of one or more factors necessary for successful tumor initiation.

  2. aroA-Deficient Salmonella enterica Serovar Typhimurium Is More Than a Metabolically Attenuated Mutant

    PubMed Central

    Frahm, Michael; Kocijancic, Dino; Rohde, Manfred; Eckweiler, Denitsa; Bielecka, Agata; Bueno, Emilio; Cava, Felipe; Abraham, Wolf-Rainer; Curtiss, Roy; Häussler, Susanne; Erhardt, Marc; Weiss, Siegfried

    2016-01-01

    ABSTRACT Recombinant attenuated Salmonella enterica serovar Typhimurium strains are believed to act as powerful live vaccine carriers that are able to elicit protection against various pathogens. Auxotrophic mutations, such as a deletion of aroA, are commonly introduced into such bacteria for attenuation without incapacitating immunostimulation. In this study, we describe the surprising finding that deletion of aroA dramatically increased the virulence of attenuated Salmonella in mouse models. Mutant bacteria lacking aroA elicited increased levels of the proinflammatory cytokine tumor necrosis factor alpha (TNF-α) after systemic application. A detailed genetic and phenotypic characterization in combination with transcriptomic and metabolic profiling demonstrated that ΔaroA mutants display pleiotropic alterations in cellular physiology and lipid and amino acid metabolism, as well as increased sensitivity to penicillin, complement, and phagocytic uptake. In concert with other immunomodulating mutations, deletion of aroA affected flagellin phase variation and gene expression of the virulence-associated genes arnT and ansB. Finally, ΔaroA strains displayed significantly improved tumor therapeutic activity. These results highlight the importance of a functional shikimate pathway to control homeostatic bacterial physiology. They further highlight the great potential of ΔaroA-attenuated Salmonella for the development of vaccines and cancer therapies with important implications for host-pathogen interactions and translational medicine. PMID:27601574

  3. Targeting ESR1-Mutant Breast Cancer

    DTIC Science & Technology

    2015-09-01

    AWARD NUMBER: W81XWH-14-1-0359 TITLE: Targeting ESR1-Mutant Breast Cancer PRINCIPAL INVESTIGATOR: Dr. Sarat Chandarlapaty CONTRACTING...31 Aug 2015 4. TITLE AND SUBTITLE Targeting ESR1-Mutant Breast Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-14-1-0359 5c. PROGRAM ELEMENT...mutations found in breast cancer using both structural and cell based assays. We have now have evidence for the effects of the most recurrent

  4. Mutant IDH1 and thrombosis in gliomas.

    PubMed

    Unruh, Dusten; Schwarze, Steven R; Khoury, Laith; Thomas, Cheddhi; Wu, Meijing; Chen, Li; Chen, Rui; Liu, Yinxing; Schwartz, Margaret A; Amidei, Christina; Kumthekar, Priya; Benjamin, Carolina G; Song, Kristine; Dawson, Caleb; Rispoli, Joanne M; Fatterpekar, Girish; Golfinos, John G; Kondziolka, Douglas; Karajannis, Matthias; Pacione, Donato; Zagzag, David; McIntyre, Thomas; Snuderl, Matija; Horbinski, Craig

    2016-12-01

    Mutant isocitrate dehydrogenase 1 (IDH1) is common in gliomas, and produces D-2-hydroxyglutarate (D-2-HG). The full effects of IDH1 mutations on glioma biology and tumor microenvironment are unknown. We analyzed a discovery cohort of 169 World Health Organization (WHO) grade II-IV gliomas, followed by a validation cohort of 148 cases, for IDH1 mutations, intratumoral microthrombi, and venous thromboemboli (VTE). 430 gliomas from The Cancer Genome Atlas were analyzed for mRNAs associated with coagulation, and 95 gliomas in a tissue microarray were assessed for tissue factor (TF) protein. In vitro and in vivo assays evaluated platelet aggregation and clotting time in the presence of mutant IDH1 or D-2-HG. VTE occurred in 26-30 % of patients with wild-type IDH1 gliomas, but not in patients with mutant IDH1 gliomas (0 %). IDH1 mutation status was the most powerful predictive marker for VTE, independent of variables such as GBM diagnosis and prolonged hospital stay. Microthrombi were far less common within mutant IDH1 gliomas regardless of WHO grade (85-90 % in wild-type versus 2-6 % in mutant), and were an independent predictor of IDH1 wild-type status. Among all 35 coagulation-associated genes, F3 mRNA, encoding TF, showed the strongest inverse relationship with IDH1 mutations. Mutant IDH1 gliomas had F3 gene promoter hypermethylation, with lower TF protein expression. D-2-HG rapidly inhibited platelet aggregation and blood clotting via a novel calcium-dependent, methylation-independent mechanism. Mutant IDH1 glioma engraftment in mice significantly prolonged bleeding time. Our data suggest that mutant IDH1 has potent antithrombotic activity within gliomas and throughout the peripheral circulation. These findings have implications for the pathologic evaluation of gliomas, the effect of altered isocitrate metabolism on tumor microenvironment, and risk assessment of glioma patients for VTE.

  5. Targeting ESR1-Mutant Breast Cancer

    DTIC Science & Technology

    2015-09-01

    AWARD NUMBER: W81XWH-14-1-0359 TITLE: Targeting ESR1-Mutant Breast Cancer PRINCIPAL INVESTIGATOR: Dr. Sarat Chandarlapaty CONTRACTING...ORGANIZATION: Sloan Kettering Institute for Cancer Research New York, NY 10065 REPORT DATE: September 2015 TYPE OF REPORT: Annual Technical Report...31 Aug 2015 4. TITLE AND SUBTITLE Targeting ESR1-Mutant Breast Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-14-1-0359 5c. PROGRAM ELEMENT

  6. Quantitative Analysis of Triple Mutant Genetic Interactions

    PubMed Central

    Braberg, Hannes; Alexander, Richard; Shales, Michael; Xu, Jiewei; Franks-Skiba, Kathleen E.; Wu, Qiuqin; Haber, James E.; Krogan, Nevan J.

    2014-01-01

    The quantitative analysis of genetic interactions between pairs of gene mutations has proven effective for characterizing cellular functions but can miss important interactions for functionally redundant genes. To address this limitation, we have developed an approach termed Triple Mutant Analysis (TMA). The procedure relies on a query strain that contains two deletions in a pair of redundant or otherwise related genes, that is crossed against a panel of candidate deletion strains to isolate triple mutants and measure their growth. A central feature of TMA is to interrogate mutants that are synthetically sick when two other genes are deleted but interact minimally with either single deletion. This approach has been valuable for discovering genes that restore critical functions when the principle actors are deleted. TMA has also uncovered double mutant combinations that produce severe defects because a third protein becomes deregulated and acts in a deleterious fashion, and it has revealed functional differences between proteins presumed to act together. The protocol is optimized for Singer ROTOR pinning robots, takes 3 weeks to complete, and measures interactions for up to 30 double mutants against a library of 1536 single mutants. PMID:25010907

  7. Isolation and characterization of unusual gin mutants.

    PubMed Central

    Klippel, A; Cloppenborg, K; Kahmann, R

    1988-01-01

    Site-specific inversion of the G segment in phage Mu DNA is promoted by two proteins, the DNA invertase Gin and the host factor FIS. Recombination occurs if the recombination sites (IR) are arranged as inverted repeats and a recombinational enhancer sequence is present in cis. Intermolecular reactions as well as deletions between direct repeats of the IRs rarely occur. Making use of a fis- mutant of Escherichia coli we have devised a scheme to isolate gin mutants that have a FIS independent phenotype. This mutant phenotype is caused by single amino acid changes at five different positions of gin. The mutant proteins display a whole set of new properties in vivo: they promote inversions, deletions and intermolecular recombination in an enhancer- and FIS-independent manner. The mutants differ in recombination activity. The most active mutant protein was analysed in vitro. The loss of site orientation specificity was accompanied with the ability to recombine even linear substrates. We discuss these results in connection with the role of the enhancer and FIS protein in the wild-type situation. Images PMID:2974801

  8. Brucellosis Vaccines: Assessment of Brucella melitensis Lipopolysaccharide Rough Mutants Defective in Core and O-Polysaccharide Synthesis and Export

    PubMed Central

    González, David; Grilló, María-Jesús; De Miguel, María-Jesús; Ali, Tara; Arce-Gorvel, Vilma; Delrue, Rose-May; Conde-Álvarez, Raquel; Muñoz, Pilar; López-Goñi, Ignacio; Iriarte, Maite; Marín, Clara-M.; Weintraub, Andrej; Widmalm, Göran; Zygmunt, Michel; Letesson, Jean-Jacques; Gorvel, Jean-Pierre; Blasco, José-María; Moriyón, Ignacio

    2008-01-01

    Background The brucellae are facultative intracellular bacteria that cause brucellosis, one of the major neglected zoonoses. In endemic areas, vaccination is the only effective way to control this disease. Brucella melitensis Rev 1 is a vaccine effective against the brucellosis of sheep and goat caused by B. melitensis, the commonest source of human infection. However, Rev 1 carries a smooth lipopolysaccharide with an O-polysaccharide that elicits antibodies interfering in serodiagnosis, a major problem in eradication campaigns. Because of this, rough Brucella mutants lacking the O-polysaccharide have been proposed as vaccines. Methodology/Principal Findings To examine the possibilities of rough vaccines, we screened B. melitensis for lipopolysaccharide genes and obtained mutants representing all main rough phenotypes with regard to core oligosaccharide and O-polysaccharide synthesis and export. Using the mouse model, mutants were classified into four attenuation patterns according to their multiplication and persistence in spleens at different doses. In macrophages, mutants belonging to three of these attenuation patterns reached the Brucella characteristic intracellular niche and multiplied intracellularly, suggesting that they could be suitable vaccine candidates. Virulence patterns, intracellular behavior and lipopolysaccharide defects roughly correlated with the degree of protection afforded by the mutants upon intraperitoneal vaccination of mice. However, when vaccination was applied by the subcutaneous route, only two mutants matched the protection obtained with Rev 1 albeit at doses one thousand fold higher than this reference vaccine. These mutants, which were blocked in O-polysaccharide export and accumulated internal O-polysaccharides, stimulated weak anti-smooth lipopolysaccharide antibodies. Conclusions/Significance The results demonstrate that no rough mutant is equal to Rev 1 in laboratory models and question the notion that rough vaccines are

  9. Context-dependent activation kinetics elicited by soluble versus outer membrane vesicle-associated heat-labile enterotoxin.

    PubMed

    Chutkan, Halima; Kuehn, Meta J

    2011-09-01

    Enterotoxigenic Escherichia coli (ETEC) is the leading cause of traveler's diarrhea and children's diarrhea worldwide. Among its virulence factors, ETEC produces heat-labile enterotoxin (LT). Most secreted LT is associated with outer membrane vesicles that are rich in lipopolysaccharide. The majority of prior studies have focused on soluble LT purified from ETEC periplasm. We investigated the hypothesis that the extracellular vesicle context of toxin presentation might be important in eliciting immune responses. We compared the polarized epithelial cell responses to apically applied soluble LT and LT-containing vesicles (LT(+) vesicles) as well as controls using a catalytically inactive mutant of LT and vesicles lacking LT. Although vesicle treatments with no or catalytically inactive LT induced a modest amount of interleukin-6 (IL-6), samples containing catalytically active LT elicited higher levels. A combination of soluble LT and LT-deficient vesicles induced significantly higher IL-6 levels than either LT or LT(+) vesicles alone. The responses to LT(+) vesicles were found to be independent of the canonical LT pathway, because the inhibition of cyclic AMP response element (CRE)-binding protein (CREB) phosphorylation did not lead to a decrease in cytokine gene expression levels. Furthermore, soluble LT caused earlier phosphorylation of CREB and activation of CRE compared with LT(+) vesicles. Soluble LT also led to the activation of activator protein 1, whereas LT(+) vesicle IL-6 responses appeared to be mediated by NF-κB. In summary, the results demonstrate that soluble LT and vesicle-bound LT elicit ultimately similar cytokine responses through distinct different activation pathways.

  10. Sustained Hypoxia Elicits Competing Spinal Mechanisms of Phrenic Motor Facilitation

    PubMed Central

    Devinney, Michael J.; Nichols, Nicole L.

    2016-01-01

    Acute intermittent hypoxia (AIH) induces phrenic long-term facilitation (pLTF), a form of spinal motor plasticity. Competing mechanisms give rise to phrenic motor facilitation (pMF; a general term including pLTF) depending on the severity of hypoxia within episodes. In contrast, moderate acute sustained hypoxia (mASH) does not elicit pMF. By varying the severity of ASH and targeting competing mechanisms of pMF, we sought to illustrate why moderate AIH (mAIH) elicits pMF but mASH does not. Although mAIH elicits serotonin-dependent pLTF, mASH does not; thus, mAIH-induced pLTF is pattern sensitive. In contrast, severe AIH (sAIH) elicits pLTF through adenosine-dependent mechanisms, likely from greater extracellular adenosine accumulation. Because serotonin- and adenosine-dependent pMF interact via cross talk inhibition, we hypothesized that pMF is obscured because the competing mechanisms of pMF are balanced and offsetting during mASH. Here, we demonstrate the following: (1) blocking spinal A2A receptors with MSX-3 reveals mASH-induced pMF; and (2) sASH elicits A2A-dependent pMF. In anesthetized rats pretreated with intrathecal A2A receptor antagonist injections before mASH (PaO2 = 40–54 mmHg) or sASH (PaO2 = 25–36 mmHg), (1) mASH induced a serotonin-dependent pMF and (2) sASH induced an adenosine-dependent pMF, which was enhanced by spinal serotonin receptor inhibition. Thus, competing adenosine- and serotonin-dependent mechanisms contribute differentially to pMF depending on the pattern/severity of hypoxia. Understanding interactions between these mechanisms has clinical relevance as we develop therapies to treat severe neuromuscular disorders that compromise somatic motor behaviors, including breathing. Moreover, these results demonstrate how competing mechanisms of plasticity can give rise to pattern sensitivity in pLTF. SIGNIFICANCE STATEMENT Intermittent hypoxia elicits pattern-sensitive spinal plasticity and improves motor function after spinal injury or

  11. Elicitation of neurological knowledge with argument-based machine learning.

    PubMed

    Groznik, Vida; Guid, Matej; Sadikov, Aleksander; Možina, Martin; Georgiev, Dejan; Kragelj, Veronika; Ribarič, Samo; Pirtošek, Zvezdan; Bratko, Ivan

    2013-02-01

    The paper describes the use of expert's knowledge in practice and the efficiency of a recently developed technique called argument-based machine learning (ABML) in the knowledge elicitation process. We are developing a neurological decision support system to help the neurologists differentiate between three types of tremors: Parkinsonian, essential, and mixed tremor (comorbidity). The system is intended to act as a second opinion for the neurologists, and most importantly to help them reduce the number of patients in the "gray area" that require a very costly further examination (DaTSCAN). We strive to elicit comprehensible and medically meaningful knowledge in such a way that it does not come at the cost of diagnostic accuracy. To alleviate the difficult problem of knowledge elicitation from data and domain experts, we used ABML. ABML guides the expert to explain critical special cases which cannot be handled automatically by machine learning. This very efficiently reduces the expert's workload, and combines expert's knowledge with learning data. 122 patients were enrolled into the study. The classification accuracy of the final model was 91%. Equally important, the initial and the final models were also evaluated for their comprehensibility by the neurologists. All 13 rules of the final model were deemed as appropriate to be able to support its decisions with good explanations. The paper demonstrates ABML's advantage in combining machine learning and expert knowledge. The accuracy of the system is very high with respect to the current state-of-the-art in clinical practice, and the system's knowledge base is assessed to be very consistent from a medical point of view. This opens up the possibility to use the system also as a teaching tool. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Estimating unknown parameters in haemophilia using expert judgement elicitation.

    PubMed

    Fischer, K; Lewandowski, D; Janssen, M P

    2013-09-01

    The increasing attention to healthcare costs and treatment efficiency has led to an increasing demand for quantitative data concerning patient and treatment characteristics in haemophilia. However, most of these data are difficult to obtain. The aim of this study was to use expert judgement elicitation (EJE) to estimate currently unavailable key parameters for treatment models in severe haemophilia A. Using a formal expert elicitation procedure, 19 international experts provided information on (i) natural bleeding frequency according to age and onset of bleeding, (ii) treatment of bleeds, (iii) time needed to control bleeding after starting secondary prophylaxis, (iv) dose requirements for secondary prophylaxis according to onset of bleeding, and (v) life-expectancy. For each parameter experts provided their quantitative estimates (median, P10, P90), which were combined using a graphical method. In addition, information was obtained concerning key decision parameters of haemophilia treatment. There was most agreement between experts regarding bleeding frequencies for patients treated on demand with an average onset of joint bleeding (1.7 years): median 12 joint bleeds per year (95% confidence interval 0.9-36) for patients ≤ 18, and 11 (0.8-61) for adult patients. Less agreement was observed concerning estimated effective dose for secondary prophylaxis in adults: median 2000 IU every other day The majority (63%) of experts expected that a single minor joint bleed could cause irreversible damage, and would accept up to three minor joint bleeds or one trauma related joint bleed annually on prophylaxis. Expert judgement elicitation allowed structured capturing of quantitative expert estimates. It generated novel data to be used in computer modelling, clinical care, and trial design.

  13. Sample Size for Measuring Grammaticality in Preschool Children from Picture-Elicited Language Samples

    ERIC Educational Resources Information Center

    Eisenberg, Sarita L.; Guo, Ling-Yu

    2015-01-01

    Purpose: The purpose of this study was to investigate whether a shorter language sample elicited with fewer pictures (i.e., 7) would yield a percent grammatical utterances (PGU) score similar to that computed from a longer language sample elicited with 15 pictures for 3-year-old children. Method: Language samples were elicited by asking forty…

  14. Developing Socio-Cultural Scaffolding Model to Elicit Learners's Speech Production

    ERIC Educational Resources Information Center

    Englishtina, Inti

    2015-01-01

    This study is concerned with developing scaffolding model to elicit bilingual kindergarten children's English speech production. It is aimed at describing what the teachers need in eliciting their students' speech production; how a scaffolding model should be developed to elicit the children's speech production; and how effective is the…

  15. Research Dilemmas Associated with Photo Elicitation in Comparative Early Childhood Education Research

    ERIC Educational Resources Information Center

    Birkeland, Asta

    2013-01-01

    Photo elicitation has become an important method to produce data in qualitative research. There is quite an extensive literature indicating the benefits of photo elicitation in order to facilitate collaboration in meaning making between researcher and the interviewee. This article addresses dilemmas associated with using photo elicitation in a…

  16. Sample Size for Measuring Grammaticality in Preschool Children from Picture-Elicited Language Samples

    ERIC Educational Resources Information Center

    Eisenberg, Sarita L.; Guo, Ling-Yu

    2015-01-01

    Purpose: The purpose of this study was to investigate whether a shorter language sample elicited with fewer pictures (i.e., 7) would yield a percent grammatical utterances (PGU) score similar to that computed from a longer language sample elicited with 15 pictures for 3-year-old children. Method: Language samples were elicited by asking forty…

  17. Simplifying Probability Elicitation and Uncertainty Modeling in Bayesian Networks

    SciTech Connect

    Paulson, Patrick R; Carroll, Thomas E; Sivaraman, Chitra; Neorr, Peter A; Unwin, Stephen D; Hossain, Shamina S

    2011-04-16

    In this paper we contribute two methods that simplify the demands of knowledge elicitation for particular types of Bayesian networks. The first method simplify the task of providing probabilities when the states that a random variable takes can be described by a new, fully ordered state set in which a state implies all the preceding states. The second method leverages Dempster-Shafer theory of evidence to provide a way for the expert to express the degree of ignorance that they feel about the estimates being provided.

  18. Electronic health records: eliciting behavioral health providers' beliefs.

    PubMed

    Shank, Nancy; Willborn, Elizabeth; Pytlikzillig, Lisa; Noel, Harmonijoie

    2012-04-01

    Interviews with 32 community behavioral health providers elicited perceived benefits and barriers of using electronic health records. Themes identified were (a) quality of care, (b) privacy and security, and (c) delivery of services. Benefits to quality of care were mentioned by 100% of the providers, and barriers by 59% of providers. Barriers involving privacy and security concerns were mentioned by 100% of providers, and benefits by 22%. Barriers to delivery of services were mentioned by 97% of providers, and benefits by 66%. Most providers (81%) expressed overall positive support for electronic behavioral health records.

  19. Quantifying catchment water balances and their uncertainties by expert elicitation

    NASA Astrophysics Data System (ADS)

    Sebok, Eva; Refsgaard, Jens Christian; Warmink, Jord J.; Stisen, Simon; Høgh Jensen, Karsten

    2017-04-01

    The increasing demand on water resources necessitates a more responsible and sustainable water management requiring a thorough understanding of hydrological processes both on small scale and on catchment scale. On catchment scale, the characterization of hydrological processes is often carried out by calculating a water balance based on the principle of mass conservation in hydrological fluxes. Assuming a perfect water balance closure and estimating one of these fluxes as a residual of the water balance is a common practice although this estimate will contain uncertainties related to uncertainties in the other components. Water balance closure on the catchment scale is also an issue in Denmark, thus, it was one of the research objectives of the HOBE hydrological observatory, that has been collecting data in the Skjern river catchment since 2008. Water balance components in the 1050 km2 Ahlergaarde catchment and the nested 120 km2 Holtum catchment, located in the glacial outwash plan of the Skjern catchment, were estimated using a multitude of methods. As the collected data enables the complex assessment of uncertainty of both the individual water balance components and catchment-scale water balances, the expert elicitation approach was chosen to integrate the results of the hydrological observatory. This approach relies on the subjective opinion of experts whose available knowledge and experience about the subject allows to integrate complex information from multiple sources. In this study 35 experts were involved in a multi-step elicitation process with the aim of (1) eliciting average annual values of water balance components for two nested catchments and quantifying the contribution of different sources of uncertainties to the total uncertainty in these average annual estimates; (2) calculating water balances for two catchments by reaching consensus among experts interacting in form of group discussions. To address the complex problem of water balance closure

  20. Understanding, eliciting and negotiating clients' multicultural health beliefs.

    PubMed

    Jackson, L E

    1993-04-01

    People of many cultures explain and treat illness in ways that are different from and that may conflict with the biomedical beliefs and practices on which the American health care system is based. Eliciting clients' health beliefs and negotiating treatment plans with them can help avoid problems caused by discrepancies in belief systems. This article presents three major categories of belief systems commonly found in the United States as well as other countries. Questions designed to discover clients' health beliefs are included, along with guidelines for arriving at plans of care that accommodate those beliefs. Case studies are provided that illustrate this process of negotiation.

  1. Development of a novel rat mutant with spontaneous limbic-like seizures.

    PubMed Central

    Amano, S.; Ihara, N.; Uemura, S.; Yokoyama, M.; Ikeda, M.; Serikawa, T.; Sasahara, M.; Kataoka, H.; Hayase, Y.; Hazama, F.

    1996-01-01

    A new epileptic rat mutant with spontaneous seizures was developed by successive mating and selection from an inherited cataract rat. The procedures for developing the mutant and the symptomatology, electroencephalographic correlates, and neuropathology of the mutant are reported. It is possible that this rat stain will provide a useful animal model for human temporal lobe epilepsy. The seizures of the rat usually begin with face and head myoclonus, followed by rearing, and generalized clonic and tonic convulsions, all of which are symptomatologically the same as limbic seizures. Electrographic recording during generalized convulsive seizures demonstrated that sustained spike discharges emerged at the hippocampus and then propagated to the neocortex. Seizures occurred spontaneously without any artificial stimuli. Furthermore, external stimuli such as auditory, flashing light, or vestibular stimulations could not elicit epileptic attacks. Almost all of the male animals had generalized convulsions, mostly from 5 months after birth, and the frequency of the seizures increased with aging. Generalized convulsions developed in approximately 20% of the female rats. Microdysgenesis, such as abnormal neuronal clustering, neuronal disarrangement, or interruption of pyramidal neurons in the hippocampal formation, was found in the young rats that had not yet had generalized seizures. This microdysgenesis, which is though to be genetically programmed, was very interesting from the aspect of the relationship between structural abnormalities and epileptogenesis in this mutant. In addition to microdysgenesis, there was sprouting of mossy fibers into the inner molecular layer of the dentate gyrus in those adult rats that had repeated generalized convulsions. An increase of glial-fibrillary-acidic-protein-positive astrocytes with thickened and numerous processes, ie, astrogliosis, was also found in the cerebral cortex, amygdala region, and hippocampus of these adult animals. Judging

  2. Selection and evaluation of the immunogenicity of protective antigen mutants as anthrax vaccine candidates.

    PubMed

    Yan, Ming; Roehrl, Michael H; Basar, Emre; Wang, Julia Y

    2008-02-13

    Protective antigen (PA) is a central component of anthrax toxin and a major antigen in anthrax vaccines. However, the use of native PA as a vaccine is not optimal. If administered to people who have been freshly exposed to anthrax, PA may actually aid in anthrax toxin formation and thus may pose a serious safety concern for postexposure vaccination applications. A non-functional PA mutant may be a much safer alternative. To identify an improved anthrax vaccine antigen, we examined four non-functional mutants of PA, each being impaired in a critical step of the cellular intoxication pathway of PA. These mutants were Rec(-) (unable to bind PA-receptors), SSSR (resistant to activation by furin), Oligo(-) (unable to form oligomers), and DNI (Dominant Negative Inhibitory, unable to form endosomal transmembrane pores). When tested in mice and after three doses of immunization, all four mutants were highly potent in eliciting PA-specific, toxin-neutralizing antibodies, with immunogenicity increasing in the order of PAmutants, particularly DNI, hold great promise as better and safer antigens than wild-type PA for use in postexposure

  3. Dendritic reduction in Passover, a Drosophila mutant with a defective giant fiber neuronal pathway.

    PubMed

    Baird, D H; Koto, M; Wyman, R J

    1993-07-01

    The jump response to a light-off startle stimulus in Drosophila melanogaster occurs when the Giant Fiber (GF), a neuron descending from the brain to the thorax, drives the jump (tergotrochanteral) muscle motorneuron (TTMn). Nonjumping mutants have been isolated in which this response is disrupted. Flies bearing the X-chromosome mutation Passover (Pas) fail to jump in response to a light-off stimulus, and electrical stimulation of the GF in the brain no longer elicits the normal response in the TTM. We have used retrograde HRP labelling to examine the TTMn motorneuron in wild-type flies and in a variety of newly identified Pas alleles. In wild type the medial branch (MB) of the TTMn has an extensive region of apposition with the GF. In Pas alleles, there is a general reduction in anterior-posterior (A-P) extent of the medial branch but not of the posterior branch. Nevertheless, Pas alleles usually leave the TTMn close enough to the GF so that contact would not be precluded. In flies carrying a particular deficiency of Pas, Df(1) 16-3-22, including Pas/Df(1) 16-3-22 heterozygotes, there can be extensive growth of the medial-branch including a contralateral projection; these heterozygotes have more than the normal amount of overlap between the GF and the TTMn. This phenotype, originally ascribed to Pas mutants, is associated with Df(1) 16-3-22, but not with other deletions of the Pas gene. The driving of the TTMn by the GF is defective in mutant genotypes with extensive medial branches as well as in mutants where GF-TTMn contact is reduced. The fact that the TTMn grows into its normal synaptic region in mutant genotypes, but the GF pathway functions abnormally suggests that pathfinding by the TTMn is not impaired. It is more likely that the Pas mutation disrupts cell recognition, synaptogenesis, or synaptic function in the TTMn or its presynaptic partners.

  4. Chlorophyll-Protein Complexes from Euglena gracilis and Mutants Deficient in Chlorophyll b: II. Polypeptide Composition.

    PubMed

    Cunningham, F X; Schiff, J A

    1986-01-01

    Chlorophyll-protein complexes (CPs) obtained from thylakoids of Euglena gracilis Klebs var bacillaris Cori contain the following polypeptides (listed in parentheses in order of prominence after Coomassie R-250 staining of polyacrylamide gels): CP Ia (66, 18, 22, 22.5, 27.5, 21, 28, 24, 25.5, and 26 kilodaltons [kD]); CP I (66 kD); CPx (41 kD); LHCP(2) (an oligomer of LHCP) (26.5, 28, and 26 kD); CPy (27 and 19 kD); CPa (54 kD); and LHCP (26.5, 28, and 26 kD). Mutants of bacillaris low in chlorophyll b (Gr(1)BSL, G(1)BU, and O(4)BSL; Chl a/b [mol/mol] = 50-100) which lack CP Ia, LHCP(2), and LHCP also lack or are deficient in polypeptides associated with these complexes in wild-type cells. Mutants G(1) and O(4), which also lack CPy, lack the CPy-associated polypeptides found in wild-type and Gr(1). Using an antiserum which was elicited by and reacts strongly and selectively with the SDS-treated major polypeptide (26.5 kD) of the LHCP complexes of wild-type, this polypeptide is undetectable in the mutants (<0.25% of the level in wild-type on a cell basis); the antiserum does not react with the SDS-treated 28 kD polypeptide of the Euglena LHCP complexes and cross-reacts only very weakly with components in SDS-treated cells of Chlamydomonas reinhardtii Dangeard and chloroplasts of Spinacia oleracea L. cv Winter Bloomsdale. Rates of photosynthesis of the wild-type and mutant cells of Euglena are approximately equal on a cell basis when measured at light saturation, consistent with the selective loss of major antenna components but not CP I or CPa from the mutants.

  5. Characterization of shrunken endosperm mutants in barley.

    PubMed

    Ma, Jian; Jiang, Qian-Tao; Wei, Long; Wang, Ji-Rui; Chen, Guo-Yue; Liu, Ya-Xi; Li, Wei; Wei, Yu-Ming; Liu, Chunji; Zheng, You-Liang

    2014-04-10

    Despite numerous studies on shrunken endosperm mutants caused by either maternal tissues (seg) or kernel per se (sex) in barley, the molecular mechanism for all of the eight seg mutants (seg1-seg8) and some sex mutants is yet to be uncovered. In this study, we determined the amylose content, characterized granule-binding proteins, analyzed the expression of key genes involved in starch synthesis, and examined starch granule structure of both normal (Bowman and Morex) and shrunken endosperm (seg1, seg3, seg4a, seg4b, seg5, seg6, seg7, and sex1) barley accessions. Our results showed that amylose contents of shrunken endosperm mutants ranged from 8.9% (seg4a) to 25.8% (seg1). SDS-PAGE analysis revealed that 87 kDa proteins corresponding to the starch branching enzyme II (SBEII) and starch synthase II (SSII) were not present in seg1, seg3, seg6, and seg7 mutants. Real-time quantitative PCR (RT-qPCR) analysis indicated that waxy expression levels of seg1, seg3, seg6, and seg7 mutants decreased in varying degrees to lower levels until 27 days after anthesis (DAA) after reaching the peak at 15-21 DAA, which differed from the pattern of normal barley accessions. Further characterization of waxy alleles revealed 7 non-synonymous single nucleotide polymorphisms (SNPs) in the coding sequences and 16 SNPs and 8 indels in the promoter sequences of the mutants. Results from starch granule by scanning electron microscopy (SEM) indicated that, in comparison with normal barley accessions, seg4a, seg4b, and sex1 had fewer starch granules per grain; seg3 and seg6 had less small B-type granules; some large A-type granules in seg7 had a hollow surface. These results improve our understanding about effects of seg and sex mutants on starch biosynthesis and granule structure during endosperm development and provide information for identification of key genes responsible for these shrunken endosperm mutants.

  6. Phanerochaete mutants with enhanced ligninolytic activity

    SciTech Connect

    Kakar, S.N.; Perez, A.; Gonzales, J.

    1993-06-01

    In addition to lignin, the white rot fungus Phanerochaete chrysosporium has the ability to degrade a wide spectrum of recalcitrant organopollutants in soils and aqueous media. Although some of the organic compounds are degraded under nonligninolytic conditions, most are degraded under ligninolytic conditions with the involvement of the extracellular enzymes, lignin peroxidases, and manganese-dependent peroxidases, which are produced as secondary metabolites triggered by conditions of nutrient starvation (e.g., nitrogen limitation). The fungus and its enzymes can thus provide alternative technologies for bioremediation, biopulping, biobleaching, and other industrial applications. The efficiency and effectiveness of the fungus can be enhanced by increasing production and secretion of the important enzymes in large quantities and as primary metabolites under enriched conditions. One way this can be achieved is through isolation of mutants that are deregulated or are hyperproducers or supersecretors of key enzymes under enriched conditions. Through ultraviolet-light and gamma-rays mutagenesis we have isolated a variety of mutants, some of which produce key enzymes of the ligninolytic system under high-nitrogen growth conditions. One of the mutants produced 272 units (U) of lignin peroxidases enzyme activity per liter after nine days under high nitrogen. The mutant and the parent strains produced up to 54 U/L and 62 U/L, respectively, of the enzyme activity under low-nitrogen growth conditions during this period. In some experiments the mutant showed 281 U/L of enzyme activity under high nitrogen after 17 days.

  7. Computing border bases using mutant strategies

    NASA Astrophysics Data System (ADS)

    Ullah, E.; Abbas Khan, S.

    2014-01-01

    Border bases, a generalization of Gröbner bases, have actively been addressed during recent years due to their applicability to industrial problems. In cryptography and coding theory a useful application of border based is to solve zero-dimensional systems of polynomial equations over finite fields, which motivates us for developing optimizations of the algorithms that compute border bases. In 2006, Kehrein and Kreuzer formulated the Border Basis Algorithm (BBA), an algorithm which allows the computation of border bases that relate to a degree compatible term ordering. In 2007, J. Ding et al. introduced mutant strategies bases on finding special lower degree polynomials in the ideal. The mutant strategies aim to distinguish special lower degree polynomials (mutants) from the other polynomials and give them priority in the process of generating new polynomials in the ideal. In this paper we develop hybrid algorithms that use the ideas of J. Ding et al. involving the concept of mutants to optimize the Border Basis Algorithm for solving systems of polynomial equations over finite fields. In particular, we recall a version of the Border Basis Algorithm which is actually called the Improved Border Basis Algorithm and propose two hybrid algorithms, called MBBA and IMBBA. The new mutants variants provide us space efficiency as well as time efficiency. The efficiency of these newly developed hybrid algorithms is discussed using standard cryptographic examples.

  8. Bee Threat Elicits Alarm Call in African Elephants

    PubMed Central

    Douglas-Hamilton, Iain; Savage, Anne; Vollrath, Fritz

    2010-01-01

    Unlike the smaller and more vulnerable mammals, African elephants have relatively few predators that threaten their survival. The sound of disturbed African honeybees Apis meliffera scutellata causes African elephants Loxodonta africana to retreat and produce warning vocalizations that lead other elephants to join the flight. In our first experiment, audio playbacks of bee sounds induced elephants to retreat and elicited more head-shaking and dusting, reactive behaviors that may prevent bee stings, compared to white noise control playbacks. Most importantly, elephants produced distinctive “rumble” vocalizations in response to bee sounds. These rumbles exhibited an upward shift in the second formant location, which implies active vocal tract modulation, compared to rumbles made in response to white noise playbacks. In a second experiment, audio playbacks of these rumbles produced in response to bees elicited increased headshaking, and further and faster retreat behavior in other elephants, compared to control rumble playbacks with lower second formant frequencies. These responses to the bee rumble stimuli occurred in the absence of any bees or bee sounds. This suggests that these elephant rumbles may function as referential signals, in which a formant frequency shift alerts nearby elephants about an external threat, in this case, the threat of bees. PMID:20436682

  9. Expert elicitation survey on future wind energy costs

    SciTech Connect

    Wiser, Ryan; Jenni, Karen; Seel, Joachim; Baker, Erin; Hand, Maureen; Lantz, Eric; Smith, Aaron

    2016-09-12

    Wind energy supply has grown rapidly over the last decade. However, the long-term contribution of wind to future energy supply, and the degree to which policy support is necessary to motivate higher levels of deployment, depends -- in part -- on the future costs of both onshore and offshore wind. Here, we summarize the results of an expert elicitation survey of 163 of the world's foremost wind experts, aimed at better understanding future costs and technology advancement possibilities. Results suggest significant opportunities for cost reductions, but also underlying uncertainties. Under the median scenario, experts anticipate 24-30% reductions by 2030 and 35-41% reductions by 2050 across the three wind applications studied. Costs could be even lower: experts predict a 10% chance that reductions will be more than 40% by 2030 and more than 50% by 2050. Insights gained through expert elicitation complement other tools for evaluating cost-reduction potential, and help inform policy and planning, R&D and industry strategy.

  10. Expert elicitation survey on future wind energy costs

    NASA Astrophysics Data System (ADS)

    Wiser, Ryan; Jenni, Karen; Seel, Joachim; Baker, Erin; Hand, Maureen; Lantz, Eric; Smith, Aaron

    2016-10-01

    Wind energy supply has grown rapidly over the last decade. However, the long-term contribution of wind to future energy supply, and the degree to which policy support is necessary to motivate higher levels of deployment, depends—in part—on the future costs of both onshore and offshore wind. Here, we summarize the results of an expert elicitation survey of 163 of the world’s foremost wind experts, aimed at better understanding future costs and technology advancement possibilities. Results suggest significant opportunities for cost reductions, but also underlying uncertainties. Under the median scenario, experts anticipate 24-30% reductions by 2030 and 35-41% reductions by 2050 across the three wind applications studied. Costs could be even lower: experts predict a 10% chance that reductions will be more than 40% by 2030 and more than 50% by 2050. Insights gained through expert elicitation complement other tools for evaluating cost-reduction potential, and help inform policy and planning, R&D and industry strategy.

  11. Emotion Elicitation: A Comparison of Pictures and Films

    PubMed Central

    Uhrig, Meike K.; Trautmann, Nadine; Baumgärtner, Ulf; Treede, Rolf-Detlef; Henrich, Florian; Hiller, Wolfgang; Marschall, Susanne

    2016-01-01

    Pictures and film clips are widely used and accepted stimuli to elicit emotions. Based on theoretical arguments it is often assumed that the emotional effects of films exceed those of pictures, but to date this assumption has not been investigated directly. The aim of the present study was to compare pictures and films in terms of their capacity to induce emotions verified by means of explicit measures. Stimuli were (a) single pictures presented for 6 s, (b) a set of three consecutive pictures with emotionally congruent contents presented for 2 s each, (c) short film clips with a duration of 6 s. A total of 144 participants rated their emotion and arousal states following stimulus presentation. Repeated-measures ANOVAs revealed that the film clips and 3-picture version were as effective as the classical 1-picture method to elicit positive emotions, however, modulation toward positive valence was little. Modulation toward negative valence was more effective in general. Film clips were less effective than pictorial stimuli in producing the corresponding emotion states (all p < 0.001) and were less arousing (all p ≤ 0.02). Possible reasons for these unexpected results are discussed. PMID:26925007

  12. Vibrio elicits targeted transcriptional responses from copepod hosts.

    PubMed

    Almada, Amalia A; Tarrant, Ann M

    2016-06-01

    Copepods are abundant crustaceans that harbor diverse bacterial communities, yet the nature of their interactions with microbiota are poorly understood. Here, we report that Vibrio elicits targeted transcriptional responses in the estuarine copepod Eurytemora affinis We pre-treated E. affinis with an antibiotic cocktail and exposed them to either a zooplankton specialist (Vibrio sp. F10 9ZB36) or a free-living species (Vibrio ordalii 12B09) for 24 h. We then identified via RNA-Seq a total of 78 genes that were differentially expressed following Vibrio exposure, including homologs of C-type lectins, chitin-binding proteins and saposins. The response differed between the two Vibrio treatments, with the greatest changes elicited upon inoculation with V. sp. F10 We suggest that these differentially regulated genes play important roles in cuticle integrity, the innate immune response, and general stress response, and that their expression may enable E. affinis to recognize and regulate symbiotic vibrios. We further report that V. sp. F10 culturability is specifically altered upon colonization of E. affinis These findings suggest that rather than acting as passive environmental vectors, copepods discriminately interact with vibrios, which may ultimately impact the abundance and activity of copepod-associated bacteria.

  13. Cognitive constraints on constituent order: Evidence from elicited pantomime

    PubMed Central

    Hall, Matthew L.; Mayberry, Rachel I.; Ferreira, Victor S.

    2014-01-01

    To what extent does human cognition influence the structure of human language? Recent experiments using elicited pantomime suggest that the prevalence of Subject-Object-Verb (SOV) order across the world's languages may arise in part because SOV order is most compatible with how we conceptually represent transitive events (Goldin-Meadow, So, Özyürek, & Mylander, 2008). However, this raises the question as to why non-SOV orders exist. Two recent studies (Meir, Lifshitz, Ilkbasaran, & Padden, 2010; Gibson et al., 2013) suggest that SOV might be suboptimal for describing events in which both the agent and patient are plausible agents (e.g. a woman pushing a boy); we call these “reversible” events. We replicate these findings using elicited pantomime and offer a new interpretation. Meir et al.'s (2010) account is framed largely in terms of constraints on comprehension, while Gibson et al.'s (2013) account involves minimizing the risk of information loss or memory degradation. We offer an alternative hypothesis that is grounded in constraints on production. We consider the implications of these findings for the distribution of constituent order in the world's spoken languages and for the structure of emerging sign languages. PMID:23792806

  14. Interviewing strategically to elicit admissions from guilty suspects.

    PubMed

    Tekin, Serra; Granhag, Pär Anders; Strömwall, Leif; Giolla, Erik Mac; Vrij, Aldert; Hartwig, Maria

    2015-06-01

    In this article we introduce a novel interviewing tactic to elicit admissions from guilty suspects. By influencing the suspects' perception of the amount of evidence the interviewer holds against them, we aimed to shift the suspects' counterinterrogation strategies from less to more forthcoming. The proposed tactic (SUE-Confrontation) is a development of the Strategic Use of Evidence (SUE) framework and aims to affect the suspects' perception by confronting them with statement-evidence inconsistencies. Participants (N = 90) were asked to perform several mock criminal tasks before being interviewed using 1 of 3 interview techniques: (a) SUE-Confrontation, (b) Early Disclosure of Evidence, or (c) No Disclosure of Evidence. As predicted, the SUE-Confrontation interview generated more statement-evidence inconsistencies from suspects than the Early Disclosure interview. Importantly, suspects in the SUE-Confrontation condition (vs. Early and No disclosure conditions) admitted more self-incriminating information and also perceived the interviewer to have had more information about the critical phase of the crime (the phase where the interviewer lacked evidence). The findings show the adaptability of the SUE-technique and how it may be used as a tool for eliciting admissions.

  15. Concert hall acoustics assessment with individually elicited attributes.

    PubMed

    Lokki, Tapio; Patynen, Jukka; Kuusinen, Antti; Vertanen, Heikki; Tervo, Sakari

    2011-08-01

    Concert hall acoustics was evaluated with a descriptive sensory analysis method by employing an individual vocabulary development technique. The goal was to obtain sensory profiles of three concert halls by eliciting perceptual attributes for evaluation and comparison of the halls. The stimuli were gathered by playing back anechoic symphony music from 34 loudspeakers on stage in each concert hall and recording the sound field with a microphone array. Four musical programs were processed for multichannel 3D sound reproduction in the actual listening test. Twenty screened assessors developed their individual set of attributes and performed a comparative evaluation of nine seats, three in each hall. The results contain the distinctive groups of elicited attributes and show good agreement within assessors, even though they applied individual attributes when rating the samples. It was also found that loudness and distance gave the strongest perceptual direction to the principal component basis. In addition, the study revealed that the perception of reverberance is related to the size of the space or to the enveloping reverberance, depending on the assessor.

  16. Experimental elicitation with hydroxyisohexyl-3-cyclohexene carboxaldehyde-containing deodorants.

    PubMed

    Jørgensen, Pia Haslund; Jensen, Charlotte Devantier; Rastogi, Suresh; Andersen, Klaus Ejner; Johansen, Jeanne Duus

    2007-03-01

    Hydroxyisohexyl-3-cyclohexene carboxaldehyde (HICC) known as Lyral is a frequent allergen. It is used in more than 50% of marketed deodorants. The aim of the present study was to determine elicitation thresholds for HICC under simulated conditions of deodorant use. 15 patients with previously diagnosed contact allergy to HICC were patch tested with 5 solutions of HICC-scented and HICC-unscented deodorants. Patients and 10 healthy controls performed a use test in the axillae using deodorants scented with HICC in increasing concentrations and unscented deodorants as control. The concentration of HICC was increased every second week (200, 600, and 1800 p.p.m.) until either a reaction developed or for 6 weeks. 14 patients completed the study, and all developed unilateral eczema from the HICC-containing deodorant, while controls were all negative (P= 0.004). In 9/14 patients, a positive use test developed during the first 2 weeks to the deodorant containing 200 p.p.m. HICC. Positive correlations were found between the day of positive use and patch test threshold concentration of the HICC solutions (r= 0.71, P= 0.01) as well as the patch test thresholds of the HICC-scented deodorants (r= 0.74, P= 0.007). In conclusion, HICC elicits allergic contact dermatitis in a high proportion of sensitized individuals at common usage concentrations in deodorants.

  17. Epigenetic mechanisms elicited by nutrition in early life.

    PubMed

    Canani, Roberto Berni; Costanzo, Margherita Di; Leone, Ludovica; Bedogni, Giorgio; Brambilla, Paolo; Cianfarani, Stefano; Nobili, Valerio; Pietrobelli, Angelo; Agostoni, Carlo

    2011-12-01

    A growing number of studies focusing on the developmental origin of health and disease hypothesis have identified links among early nutrition, epigenetic processes and diseases also in later life. Different epigenetic mechanisms are elicited by dietary factors in early critical developmental ages that are able to affect the susceptibility to several diseases in adulthood. The studies here reviewed suggest that maternal and neonatal diet may have long-lasting effects in the development of non-communicable chronic adulthood diseases, in particular the components of the so-called metabolic syndrome, such as insulin resistance, type 2 diabetes, obesity, dyslipidaemia, hypertension, and CVD. Both maternal under- and over-nutrition may regulate the expression of genes involved in lipid and carbohydrate metabolism. Early postnatal nutrition may also represent a vital determinant of adult health by making an impact on the development and function of gut microbiota. An inadequate gut microbiota composition and function in early life seems to account for the deviant programming of later immunity and overall health status. In this regard probiotics, which have the potential to restore the intestinal microbiota balance, may be effective in preventing the development of chronic immune-mediated diseases. More recently, the epigenetic mechanisms elicited by probiotics through the production of SCFA are hypothesised to be the key to understand how they mediate their numerous health-promoting effects from the gut to the peripheral tissues.

  18. TRANSFER OF AVERSIVE RESPONDENT ELICITATION IN ACCORDANCE WITH EQUIVALENCE RELATIONS

    PubMed Central

    Valverde, Miguel RodrÍguez; Luciano, Carmen; Barnes-Holmes, Dermot

    2009-01-01

    The present study investigates the transfer of aversively conditioned respondent elicitation through equivalence classes, using skin conductance as the measure of conditioning. The first experiment is an attempt to replicate Experiment 1 in Dougher, Augustson, Markham, Greenway, and Wulfert (1994), with different temporal parameters in the aversive conditioning procedure employed. Match-to-sample procedures were used to teach 17 participants two 4-member equivalence classes. Then, one member of one class was paired with electric shock and one member of the other class was presented without shock. The remaining stimuli from each class were presented in transfer tests. Unlike the findings in the original study, transfer of conditioning was not achieved. In Experiment 2, similar procedures were used with 30 participants, although several modifications were introduced (formation of five-member classes, direct conditioning with several elements of each class, random sequences of stimulus presentation in transfer tests, reversal in aversive conditioning contingencies). More than 80% of participants who had shown differential conditioning also showed the transfer of function effect. Moreover, this effect was replicated within subjects for 3 participants. This is the first demonstration of the transfer of aversive respondent elicitation through stimulus equivalence classes with the presentation of transfer test trials in random order. The latter prevents the possibility that transfer effects are an artefact of transfer test presentation order. PMID:20119523

  19. Eliciting spatial statistics from geological experts using genetic algorithms

    NASA Astrophysics Data System (ADS)

    Walker, Matthew; Curtis, Andrew

    2014-07-01

    A new method to obtain the statistics of a geostatistical model is introduced. The method elicits the statistical information from a geological expert directly, by iteratively updating a population of vectors of statistics, based on the expert's subjective opinion of the corresponding geological simulations. Thus, it does not require the expert to have knowledge of the mathematical and statistical details of the model. The process uses a genetic algorithm to generate new vectors. We demonstrate the methodology for a particular geostatistical model used to model rock pore-space, which simulates the spatial distribution of matrix and pores over a 2-D grid, using multipoint statistics specified by conditional probabilities. Experts were asked to use the algorithm to estimate the statistics of a given target pore-space image with known statistics; thus, their numerical rates of convergence could be calculated. Convergence was measured for all experts, showing that the algorithm can be used to find appropriate probabilities given the expert's subjective input. However, considerable and apparently irreducible residual misfit was found between the true statistics and the estimates of statistics obtained by the experts, with the root-mean-square error on the conditional probabilities typically >0.1. This is interpreted as the limit of the experts' abilities to distinguish between realizations of different spatial statistics using the algorithm. More accurate discrimination is therefore likely to require complementary elicitation techniques or sources of information independent of expert opinion.

  20. Emotion Elicitation: A Comparison of Pictures and Films.

    PubMed

    Uhrig, Meike K; Trautmann, Nadine; Baumgärtner, Ulf; Treede, Rolf-Detlef; Henrich, Florian; Hiller, Wolfgang; Marschall, Susanne

    2016-01-01

    Pictures and film clips are widely used and accepted stimuli to elicit emotions. Based on theoretical arguments it is often assumed that the emotional effects of films exceed those of pictures, but to date this assumption has not been investigated directly. The aim of the present study was to compare pictures and films in terms of their capacity to induce emotions verified by means of explicit measures. Stimuli were (a) single pictures presented for 6 s, (b) a set of three consecutive pictures with emotionally congruent contents presented for 2 s each, (c) short film clips with a duration of 6 s. A total of 144 participants rated their emotion and arousal states following stimulus presentation. Repeated-measures ANOVAs revealed that the film clips and 3-picture version were as effective as the classical 1-picture method to elicit positive emotions, however, modulation toward positive valence was little. Modulation toward negative valence was more effective in general. Film clips were less effective than pictorial stimuli in producing the corresponding emotion states (all p < 0.001) and were less arousing (all p ≤ 0.02). Possible reasons for these unexpected results are discussed.

  1. Bee threat elicits alarm call in African elephants.

    PubMed

    King, Lucy E; Soltis, Joseph; Douglas-Hamilton, Iain; Savage, Anne; Vollrath, Fritz

    2010-04-26

    Unlike the smaller and more vulnerable mammals, African elephants have relatively few predators that threaten their survival. The sound of disturbed African honeybees Apis meliffera scutellata causes African elephants Loxodonta africana to retreat and produce warning vocalizations that lead other elephants to join the flight. In our first experiment, audio playbacks of bee sounds induced elephants to retreat and elicited more head-shaking and dusting, reactive behaviors that may prevent bee stings, compared to white noise control playbacks. Most importantly, elephants produced distinctive "rumble" vocalizations in response to bee sounds. These rumbles exhibited an upward shift in the second formant location, which implies active vocal tract modulation, compared to rumbles made in response to white noise playbacks. In a second experiment, audio playbacks of these rumbles produced in response to bees elicited increased headshaking, and further and faster retreat behavior in other elephants, compared to control rumble playbacks with lower second formant frequencies. These responses to the bee rumble stimuli occurred in the absence of any bees or bee sounds. This suggests that these elephant rumbles may function as referential signals, in which a formant frequency shift alerts nearby elephants about an external threat, in this case, the threat of bees.

  2. Temperature-sensitive mutants of the slime mould Physarum polycephalum. I. Mutants of the amoebal phase.

    PubMed

    Wheals, A E; Grant, W D; Jockusch, B M

    1976-11-24

    A replica plating method for isolating it amoebal mutants of Physarum polycephalum has been devised. Temperature-sensitive mutations occur at a frequency after nitrosoguanidine mutagenesis of 10(-3) per survivor, are stable but are not usually expressed in the plasmodia formed from these amoebae in clones. Some of these mutants appear to be cell-cycle stage specific.

  3. High Persister Mutants in Mycobacterium tuberculosis

    PubMed Central

    Torrey, Heather L.; Keren, Iris; Via, Laura E.; Lee, Jong Seok; Lewis, Kim

    2016-01-01

    Mycobacterium tuberculosis forms drug-tolerant persister cells that are the probable cause of its recalcitrance to antibiotic therapy. While genetically identical to the rest of the population, persisters are dormant, which protects them from killing by bactericidal antibiotics. The mechanism of persister formation in M. tuberculosis is not well understood. In this study, we selected for high persister (hip) mutants and characterized them by whole genome sequencing and transcriptome analysis. In parallel, we identified and characterized clinical isolates that naturally produce high levels of persisters. We compared the hip mutants obtained in vitro with clinical isolates to identify candidate persister genes. Genes involved in lipid biosynthesis, carbon metabolism, toxin-antitoxin systems, and transcriptional regulators were among those identified. We also found that clinical hip isolates exhibited greater ex vivo survival than the low persister isolates. Our data suggest that M. tuberculosis persister formation involves multiple pathways, and hip mutants may contribute to the recalcitrance of the infection. PMID:27176494

  4. Isolation and characterization of transcription fidelity mutants.

    PubMed

    Strathern, Jeffrey N; Jin, Ding Jun; Court, Donald L; Kashlev, Mikhail

    2012-07-01

    Accurate transcription is an essential step in maintaining genetic information. Error-prone transcription has been proposed to contribute to cancer, aging, adaptive mutagenesis, and mutagenic evolution of retroviruses and retrotransposons. The mechanisms controlling transcription fidelity and the biological consequences of transcription errors are poorly understood. Because of the transient nature of mRNAs and the lack of reliable experimental systems, the identification and characterization of defects that increase transcription errors have been particularly challenging. In this review we describe novel genetic screens for the isolation of fidelity mutants in both Saccharomyces cerevisiae and Escherichia coli RNA polymerases. We obtained and characterized two distinct classes of mutants altering NTP misincorporation and transcription slippage both in vivo and in vitro. Our study not only validates the genetic schemes for the isolation of RNA polymerase mutants that alter fidelity, but also sheds light on the mechanism of transcription accuracy. This article is part of a Special Issue entitled: Chromatin in time and space.

  5. Sleep restores behavioral plasticity to Drosophila mutants.

    PubMed

    Dissel, Stephane; Angadi, Veena; Kirszenblat, Leonie; Suzuki, Yasuko; Donlea, Jeff; Klose, Markus; Koch, Zachary; English, Denis; Winsky-Sommerer, Raphaelle; van Swinderen, Bruno; Shaw, Paul J

    2015-05-18

    Given the role that sleep plays in modulating plasticity, we hypothesized that increasing sleep would restore memory to canonical memory mutants without specifically rescuing the causal molecular lesion. Sleep was increased using three independent strategies: activating the dorsal fan-shaped body, increasing the expression of Fatty acid binding protein (dFabp), or by administering the GABA-A agonist 4,5,6,7-tetrahydroisoxazolo-[5,4-c]pyridine-3-ol (THIP). Short-term memory (STM) or long-term memory (LTM) was evaluated in rutabaga (rut) and dunce (dnc) mutants using aversive phototaxic suppression and courtship conditioning. Each of the three independent strategies increased sleep and restored memory to rut and dnc mutants. Importantly, inducing sleep also reverses memory defects in a Drosophila model of Alzheimer's disease. Together, these data demonstrate that sleep plays a more fundamental role in modulating behavioral plasticity than previously appreciated and suggest that increasing sleep may benefit patients with certain neurological disorders.

  6. Native Mutant Huntingtin in Human Brain

    PubMed Central

    Sapp, Ellen; Valencia, Antonio; Li, Xueyi; Aronin, Neil; Kegel, Kimberly B.; Vonsattel, Jean-Paul; Young, Anne B.; Wexler, Nancy; DiFiglia, Marian

    2012-01-01

    Huntington disease (HD) is caused by polyglutamine expansion in the N terminus of huntingtin (htt). Analysis of human postmortem brain lysates by SDS-PAGE and Western blot reveals htt as full-length and fragmented. Here we used Blue Native PAGE (BNP) and Western blots to study native htt in human postmortem brain. Antisera against htt detected a single band broadly migrating at 575–850 kDa in control brain and at 650–885 kDa in heterozygous and Venezuelan homozygous HD brains. Anti-polyglutamine antisera detected full-length mutant htt in HD brain. There was little htt cleavage even if lysates were pretreated with trypsin, indicating a property of native htt to resist protease cleavage. A soluble mutant htt fragment of about 180 kDa was detected with anti-htt antibody Ab1 (htt-(1–17)) and increased when lysates were treated with denaturants (SDS, 8 m urea, DTT, or trypsin) before BNP. Wild-type htt was more resistant to denaturants. Based on migration of in vitro translated htt fragments, the 180-kDa segment terminated ≈htt 670–880 amino acids. If second dimension SDS-PAGE followed BNP, the 180-kDa mutant htt was absent, and 43–50 kDa htt fragments appeared. Brain lysates from two HD mouse models expressed native full-length htt; a mutant fragment formed if lysates were pretreated with 8 m urea + DTT. Native full-length mutant htt in embryonic HD140Q/140Q mouse primary neurons was intact during cell death and when cell lysates were exposed to denaturants before BNP. Thus, native mutant htt occurs in brain and primary neurons as a soluble full-length monomer. PMID:22375012

  7. Polyomavirus middle T-antigen NPTY mutants.

    PubMed Central

    Druker, B J; Sibert, L; Roberts, T M

    1992-01-01

    A polyomavirus middle T-antigen (MTAg) mutant containing a substitution of Leu for Pro at amino acid 248 has previously been described as completely transformation defective (B. J. Druker, L. Ling, B. Cohen, T. M. Roberts, and B. S. Schaffhausen, J. Virol. 64:4454-4461, 1990). This mutant had no alterations in associated proteins or associated kinase activities compared with wild-type MTAg. Pro-248 lies in a tetrameric sequence, NPTY, which is reminiscent of the so-called NPXY sequence in the low-density-lipoprotein receptor. In the low-density-lipoprotein receptor, mutations in the NPXY motif but not in the surrounding amino acids abolish receptor function, apparently by decreasing receptor internalization (W. Chen, J. L. Goldstein, and M. S. Brown, J. Biol. Chem. 265:3116-3123, 1990). To determine whether this sequence represents a functional motif in MTAg as well, a series of single amino acid substitutions was constructed in this region of MTAg. All of the mutations of N, P, T, or Y, including the relatively conservative substitution of Ser for Thr at amino acid 249, resulted in a transformation-defective MTAg, whereas mutations outside of this sequence allowed mutants to retain near-wild-type transformation capabilities. Transformation-defective mutants with mutations in the NPTY region behaved similarly to the mutant with the original Pro-248-to-Leu-248 mutation when assayed for associated proteins and activities in vitro; that is, they retained a full complement of wild-type activities and associated proteins. Further, insertion of the tetrameric sequence NPTY downstream of the mutated motif restored transforming abilities to these mutants. Thus, the tetrameric sequence NPTY in MTAg appears to represent a well-defined functional motif of MTAg. Images PMID:1326642

  8. Genetics of a dwarf mutant in groundnut.

    PubMed

    Patil, S H; Mouli, C

    1975-01-01

    A spontaneous dwarf mutant of groundnut variety, Kopergaon-3, showed differential expression for plant height and secondary branching characters in the reciprocal F1 populations. These differences were assumed to be due to the interaction of nuclear and cytoplasmic factors which mutated with dwarfness.Segregation for dwarfness in the F2 and F3 generations confirmed the monogenic inheritance. The mutant expression was, therefore, controlled by a pair of recessive factors designated d(v)d(v), indicating dwarfism in the Valencia group.

  9. Fluoroquinolone-resistant mutants of Burkholderia cepacia.

    PubMed

    Pope, C F; Gillespie, S H; Pratten, J R; McHugh, T D

    2008-03-01

    Fluoroquinolone-resistant Burkholderia cepacia mutants were selected on ciprofloxacin. The rate of mutation in gyrA was estimated to be 9.6 x 10(-11) mutations per division. Mutations in gyrA conferred 12- to 64-fold increases in MIC, and an additional parC mutation conferred a large increase in MIC (>256-fold). Growth rate, biofilm formation, and survival in water and during drying were not impaired in strains containing single gyrA mutations. Double mutants were impaired only in growth rate (0.85, relative to the susceptible parent).

  10. Ovarian abnormalities in the staggerer mutant mouse.

    PubMed

    Guastavino, Jean-Marie; Boufares, Salima; Crusio, Wim E

    2005-08-24

    Disturbances in several reproductive functions of the staggerer cerebellar mutant mouse have been observed. In this study, reproductive efficiency of staggerer mice was compared to normal mice by recording the number of pups produced and the number of oocytes occurring. It was found that staggerer mothers produced smaller litters than controls and the number of oocytes produced in their ovaries was reduced by the staggerer mutation. These results indicate a pleiotropic effect on fertility of the Rora(sg) gene underlying the cerebellar abnormalities of the staggerer mutant.

  11. Nonphotic phase shifting in hamster clock mutants.

    PubMed

    Mrosovsky, N; Salmon, P A; Menaker, M; Ralph, M R

    1992-01-01

    Golden hamsters with the tau mutation were kept in the dark and induced to become active through confinement to a novel running wheel for 3 hr. The response of the mutants to this nonphotic phase-shifting stimulus differed from that of wild-type hamsters. The mutants showed larger phase shifts, and their phase response curves differed in shape, with an advance portion at about circadian time 24, a phase at which wild types show delays. The results establish that the tau mutation, in addition to its already known effects, alters the response of the circadian system to nonphotic events.

  12. Persistent changes of corticostriatal plasticity in dt(sz) mutant hamsters after age-dependent remission of dystonia.

    PubMed

    Avchalumov, Y; Volkmann, C E; Rückborn, K; Hamann, M; Kirschstein, T; Richter, A; Köhling, R

    2013-10-10

    Abnormal plasticity in the cortico-basal ganglia-thalamocortical loop has been suggested to represent a key factor in the pathophysiology of dystonia. In a model of primary paroxysmal dystonia, the dt(sz) mutant hamster, previous experiments have shown a strongly increased long-term potentiation (LTP) in comparison to non-dystonic control hamsters. These basal changes, i.e. in the absence of dystonia, were found in young animals at an age of 5 weeks, when the age-dependent dystonia in dt(sz) mutant reaches highest severity. In the present study we examined in corticostriatal slices (1) whether the increases in synaptic plasticity can be modulated by stressful stimuli which induce dystonic episodes in young mutant hamsters, and (2) whether increases of LTP persist after spontaneous remission of dystonia in animals older than 10 weeks. The present data show that in slices of young mutant hamsters the extent of LTP was not influenced by the presence of dystonia: In comparison to age-matched control hamsters, LTP was increased in mutant hamsters independent of preceding stressful stimulation. After remission of dystonia, i.e., in older dt(sz) mutant hamsters >10 weeks, only LTP could be elicited, while in preparations from age-matched control hamsters, either LTP or long-term depression developed, depending on previous behavioral challenge. We conclude that in mature brain, corticostriatal connections have the potential for changes in metaplasticity, while in dt(sz) mutant hamsters this metaplasticity is persistently infringed even though stress-inducible dystonic symptoms are lost. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Voice Pitch Elicited Frequency Following Response in Chinese Elderlies

    PubMed Central

    Wang, Shuo; Hu, Jiong; Dong, Ruijuan; Liu, Dongxin; Chen, Jing; Musacchia, Gabriella; Liu, Bo

    2016-01-01

    Background: Perceptual and electrophysiological studies have found reduced speech discrimination in quiet and noisy environment, delayed neural timing, decreased neural synchrony, and decreased temporal processing ability in elderlies, even those with normal hearing. However, recent studies have also demonstrated that language experience and auditory training enhance the temporal dynamics of sound encoding in the auditory brainstem response (ABR). The purpose of this study was to explore the pitch processing ability at the brainstem level in an aging population that has a tonal language background. Method: Mandarin speaking younger (n = 12) and older (n = 12) adults were recruited for this study. All participants had normal audiometric test results and normal suprathreshold click-evoked ABR. To record frequency following responses (FFRs) elicited by Mandarin lexical tones, two Mandarin Chinese syllables with different fundamental frequency pitch contours (Flat Tone and Falling Tone) were presented at 70 dB SPL. Fundamental frequencies (f0) of both the stimulus and the responses were extracted and compared to individual brainstem responses. Two indices were used to examine different aspects of pitch processing ability at the brainstem level: Pitch Strength and Pitch Correlation. Results: Lexical tone elicited FFR were overall weaker in the older adult group compared to their younger adult counterpart. Measured by Pitch Strength and Pitch Correlation, statistically significant group differences were only found when the tone with a falling f0 (Falling Tone) were used as the stimulus. Conclusion: Results of this study demonstrated that in a tonal language speaking population, pitch processing ability at the brainstem level of older adults are not as strong and robust as their younger counterparts. Findings of this study are consistent with previous reports on brainstem responses of older adults whose native language is English. On the other hand, lexical tone elicited

  14. Modifications of the Helper Component-Protease of Zucchini yellow mosaic virus for Generation of Attenuated Mutants for Cross Protection Against Severe Infection.

    PubMed

    Lin, Shih-Shun; Wu, Hui-Wen; Jan, Fuh-Jyh; Hou, Roger F; Yeh, Shyi-Dong

    2007-03-01

    ABSTRACT A nonpathogenic mild strain is essential for control of plant viruses by cross protection. Three amino acid changes, Arg(180)-->Ile(180) (GA mutation), Phe(205)-->Leu(205) (GB mutation), and Glu(396)-->Asn(396) (GC mutation), of the conserved motifs of the helper component-protease (HC-Pro) of a severe strain TW-TN3 of Zucchini yellow mosaic virus (ZYMV), a member of the genus Potyvirus, were generated from an infectious cDNA clone that carried a green fluorescent protein reporter. The infectivity of individual mutants containing single, double, or triple mutations was assayed on local and systemic hosts. On Chenopodium quinoa plants, the GB mutant induced necrotic lesions; the GA, GC, and GBC mutants induced chlorotic spots; and the GAB and GAC mutants induced local infection only visualized by fluorescence microscopy. On squash plants, the GA, GB, GC, and GBC mutants caused milder mosaic; the GAC mutant induced slight leaf mottling followed by recovering; and the GAB mutant did not induce conspicuous symptoms. Also, the GAC mutant, but not the GAB mutant, conferred complete cross protection against the parental virus carrying a mite allergen as a reporter. When tested on transgene-silenced transgenic squash, the ability of posttranscriptional gene silencing suppression of the mutated HC-Pro of GAC was not significantly affected. We concluded that the mutations of the HC-Pro of ZYMV reduce the degrees of pathogenicity on squash and also abolish the ability for eliciting the hypersensitive reaction on C. quinoa, and that the mutant GAC is a useful mild strain for cross protection.

  15. Myosin Vb uncoupling from RAB8A and RAB11A elicits microvillus inclusion disease

    PubMed Central

    Knowles, Byron C.; Roland, Joseph T.; Krishnan, Moorthy; Tyska, Matthew J.; Lapierre, Lynne A.; Dickman, Paul S.; Goldenring, James R.; Shub, Mitchell D.

    2014-01-01

    Microvillus inclusion disease (MVID) is a severe form of congenital diarrhea that arises from inactivating mutations in the gene encoding myosin Vb (MYO5B). We have examined the association of mutations in MYO5B and disruption of microvillar assembly and polarity in enterocytes. Stable MYO5B knockdown (MYO5B-KD) in CaCo2-BBE cells elicited loss of microvilli, alterations in junctional claudins, and disruption of apical and basolateral trafficking; however, no microvillus inclusions were observed in MYO5B-KD cells. Expression of WT MYO5B in MYO5B-KD cells restored microvilli; however, expression of MYO5B-P660L, a MVID-associated mutation found within Navajo populations, did not rescue the MYO5B-KD phenotype but induced formation of microvillus inclusions. Microvilli establishment required interaction between RAB8A and MYO5B, while loss of the interaction between RAB11A and MYO5B induced microvillus inclusions. Using surface biotinylation and dual immunofluorescence staining in MYO5B-KD cells expressing mutant forms of MYO5B, we observed that early microvillus inclusions were positive for the sorting marker SNX18 and derived from apical membrane internalization. In patients with MVID, MYO5B-P660L results in global changes in polarity at the villus tips that could account for deficits in apical absorption, loss of microvilli, aberrant junctions, and losses in transcellular ion transport pathways, likely leading to the MVID clinical phenotype of neonatal secretory diarrhea. PMID:24892806

  16. Microtubule redistribution in growth cones elicited by focal inactivation of kinesin-5.

    PubMed

    Nadar, Vidya C; Lin, Shen; Baas, Peter W

    2012-04-25

    In order for growth cones to turn, microtubules from the central domain must preferentially invade the peripheral domain in the direction of the turn. Recent studies suggest that kinesin-5 (also called Eg5 or kif11) suppresses the invasion of microtubules into the peripheral domain on the side of the growth cone opposite the direction of turning. In theory, kinesin-5 could elicit these effects by acting on the microtubules within the peripheral domain itself, by acting on microtubules in the central domain, or in the transition zone between these two domains. In rat neurons expressing kinesin-5, we documented the presence of kinesin-5 in both domains of the growth cone and especially enriched in the transition zone. We then focally inactivated kinesin-5 in various regions of the growth cone, using micro-chromophore-assisted laser inactivation. We found that a greater invasion of microtubules into the peripheral domain occurred when kinesin-5 was inactivated specifically in the transition zone. However, there was no effect on microtubule invasion into the peripheral domain when kinesin-5 was inactivated in the peripheral domain itself or in the central domain. In other experiments, frog growth cones were observed to turn toward a gradient of a drug that inhibits kinesin-5, confirming that asymmetric inactivation of kinesin-5 can cause the growth cone to turn. Finally, expression of a phospho-mutant of kinesin-5 resulted in greater microtubule invasion throughout the peripheral domain and an inhibition of growth cone turning, implicating phosphorylation as a means by which kinesin-5 is regulated in the growth cone.

  17. A replicating adenovirus capsid display recombinant elicits antibodies against Plasmodium falciparum sporozoites in Aotus nancymaae monkeys.

    PubMed

    Karen, Kasey A; Deal, Cailin; Adams, Robert J; Nielsen, Carolyn; Ward, Cameron; Espinosa, Diego A; Xie, Jane; Zavala, Fidel; Ketner, Gary

    2015-01-01

    Decades of success with live adenovirus vaccines suggest that replication-competent recombinant adenoviruses (rAds) could serve as effective vectors for immunization against other pathogens. To explore the potential of a live rAd vaccine against malaria, we prepared a viable adenovirus 5 (Ad5) recombinant that displays a B-cell epitope from the circumsporozoite protein (CSP) of Plasmodium falciparum on the virion surface. The recombinant induced P. falciparum sporozoite-neutralizing antibodies in mice. Human adenoviruses do not replicate in mice. Therefore, to examine immunogenicity in a system in which, as in humans, the recombinant replicates, we constructed a similar recombinant in an adenovirus mutant that replicates in monkey cells and immunized four Aotus nancymaae monkeys. The recombinant replicated in the monkeys after intratracheal instillation, the first demonstration of replication of human adenoviruses in New World monkeys. Immunization elicited antibodies both to the Plasmodium epitope and the Ad5 vector. Antibodies from all four monkeys recognized CSP on intact parasites, and plasma from one monkey neutralized sporozoites in vitro and conferred partial protection against P. falciparum sporozoite infection after passive transfer to mice. Prior enteric inoculation of two animals with antigenically wild-type adenovirus primed a response to the subsequent intratracheal inoculation, suggesting a route to optimizing performance. A vaccine is not yet available against P. falciparum, which induces the deadliest form of malaria and kills approximately one million children each year. The live capsid display recombinant described here may constitute an early step in a critically needed novel approach to malaria immunization.

  18. Outer membrane vesicles derived from Salmonella Typhimurium mutants with truncated LPS induce cross-protective immune responses against infection of Salmonella enterica serovars in the mouse model.

    PubMed

    Liu, Qiong; Liu, Qing; Yi, Jie; Liang, Kang; Liu, Tian; Roland, Kenneth L; Jiang, Yanlong; Kong, Qingke

    2016-12-01

    Salmonella enterica cause diarrheal and systemic diseases and are of considerable concern worldwide. Vaccines that are cross-protective against multiple serovars could provide effective control of Salmonella-mediated diseases. Bacteria-derived outer membrane vesicles (OMVs) are highly immunogenic and are capable of eliciting protective immune responses. Alterations in lipopolysaccharide (LPS) length can result in outer membrane remodeling and composition of outer membrane proteins (OMPs) changing. In this study, we investigated the impact of truncated LPS on both the production and immunogenicity of Salmonella OMVs, including the ability of OMVs to elicit cross-protection against challenge by heterologous Salmonella strains. We found that mutations in waaJ and rfbP enhanced vesiculation, while mutations in waaC, waaF and waaG inhibited this process. Animal experiments indicated that OMVs from waaC, rfaH and rfbP mutants induced stronger serum immune responses compared to OMVs from the parent strain, while all elicited protective responses against the wild-type S. Typhimurium challenge. Furthermore, intranasal or intraperitoneal immunization with OMVs derived from the waaC and rfbP mutants elicited significantly higher cross-reactive IgG responses and provided enhanced cross-protection against S. Choleraesuis and S. Enteritidis challenge than the wild-type OMVs. These results indicate that truncated-LPS OMVs are capable of conferring cross protection against multiple serotypes of Salmonella infection.

  19. Transcranial magnetic stimulation elicits coupled neural and hemodynamic consequences.

    PubMed

    Allen, Elena A; Pasley, Brian N; Duong, Thang; Freeman, Ralph D

    2007-09-28

    Transcranial magnetic stimulation (TMS) is an increasingly common technique used to selectively modify neural processing. However, application of TMS is limited by uncertainty concerning its physiological effects. We applied TMS to the cat visual cortex and evaluated the neural and hemodynamic consequences. Short TMS pulse trains elicited initial activation (approximately 1 minute) and prolonged suppression (5 to 10 minutes) of neural responses. Furthermore, TMS disrupted the temporal structure of activity by altering phase relationships between neural signals. Despite the complexity of this response, neural changes were faithfully reflected in hemodynamic signals; quantitative coupling was present over a range of stimulation parameters. These results demonstrate long-lasting neural responses to TMS and support the use of hemodynamic-based neuroimaging to effectively monitor these changes over time.

  20. Ontological leveling and elicitation for complex industrial transactions

    SciTech Connect

    Phillips, L.R.; Goldsmith, S.Y.; Spires, S.V.

    1998-11-01

    The authors present an agent-oriented mechanism that uses a central ontology as a means to conduct complex distributed transactions. This is done by instantiating a template object motivated solely by the ontology, then automatically and explicitly linking each temple element to an independently constructed interface component. Validation information is attached directly to the links so that the agent need not know a priori the semantics of data validity, merely how to execute a general validation process to satisfy the conditions given in the link. Ontological leveling is critical: all terms presented to informants must be semantically coherent within the central ontology. To illustrate this approach in an industrial setting, they discuss an existing implementation that conducted international commercial transactions on the World-Wide Web. Agents operating within a federated architecture construct, populate by Web-based elicitation, and manipulate a distributed composite transaction object to effect transport of goods over the US/Mexico border.

  1. Reliance on luck: identifying which achievement goals elicit superstitious behavior.

    PubMed

    Hamerman, Eric J; Morewedge, Carey K

    2015-03-01

    People often resort to superstitious behavior to facilitate goal achievement. We examined whether the specific type of achievement goal pursued influences the propensity to engage in superstitious behavior. Across six studies, we found that performance goals were more likely than learning goals to elicit superstitious behavior. Participants were more likely to engage in superstitious behavior at high than at low levels of chronic performance orientation, but superstitious behavior was not influenced by chronic learning orientation (Studies 1 and 2). Similarly, participants exhibited stronger preferences for lucky items when primed to pursue performance goals rather than learning goals (Studies 3 and 4). As uncertainty of goal achievement increased, superstitious behavior increased when participants pursued performance goals but not learning goals (Study 5). Finally, assignment to use a lucky (vs. unlucky) item resulted in greater confidence of achieving performance goals but not learning goals (Study 6).

  2. Molecular mimicry and horror autotoxicus: do chlamydial infections elicit autoimmunity?

    PubMed

    Swanborg, Robert H; Boros, Dov L; Whittum-Hudson, Judith A; Hudson, Alan P

    2006-11-30

    All species of the order Chlamydiales are obligate intracellular eubacterial pathogens of their various hosts. Two chlamydial species, Chlamydia trachomatis and Chlamydia pneumoniae, are primarily human pathogens, and each is known to cause important diseases. Some strains of C. trachomatis are sexually transmitted and frequently cause severe reproductive problems, primarily in women. Other strains of the organism serve as the aetiological agents for blinding trachoma, still the leading cause of preventable blindness in underdeveloped nations. C. pneumoniae is a respiratory pathogen known to cause community-acquired pneumonia. Importantly, both organisms engender an immunopathogenic response in the human host, and both have been associated with widely diverse, relatively common and currently idiopathic chronic diseases, most of which include an important autoimmune component. In this article, we explore the available experimental data regarding the possible elicitation of autoimmunity in various contexts by chlamydial infection, and we suggest several avenues for research to explore this potentially important issue further.

  3. PROBES: a framework for probability elicitation from experts.

    PubMed Central

    Lau, A. H.; Leong, T. Y.

    1999-01-01

    A decision analytic model represents uncertainties as probability distributions. These distributions are hard to assess especially for large and dynamic models. We propose an integrated framework that facilitates elicitation of the relevant probability distributions for dynamic decision models from the domain experts. The experts usually use some judgmental heuristics to aid probability assessments; the resulting distributions may be proned to cognitive biases. Our framework aims to minimize the effects of these biases and to improve the quality of decisions made. We have implemented a prototype system of the framework and evaluated its effectiveness via a case study in the follow-up management of colorectal cancer patients after curative surgery. Preliminary results demonstrate the practical promise of the framework. Images Figure 4 PMID:10566369

  4. Unnoticed regularity violation elicits change-related brain activity.

    PubMed

    Czigler, István; Pató, Lívia

    2009-03-01

    Event-related brain electric activity (ERP) was investigated to unnoticed visual changes. The orientation of grid elements (vertical or horizontal) changed after the presentation of 10-15 identical stimuli. The grid patterns were task irrelevant, and were presented in the background of a shape discrimination task. During the first half of the session, participants were unaware of the stimulus change. However, in comparison to the ERPs to the fifth identical stimuli, stimulus change elicited posterior negativities in the 270-375 ms range (visual mismatch negativity, vMMN). With participants instructed on the stimulus change, negativities emerged with earlier onset and with wider distribution. When stimulus change was preceded by only two identical stimuli, there were no such ERP effects. As the results show, a longer sequence of identical unattended stimuli may establish the memory representation of stimulus regularity, and violation of regularity is indicated by posterior negative ERP components (vMMN).

  5. Eliciting the Level of Health Inequality Aversion in England.

    PubMed

    Robson, Matthew; Asaria, Miqdad; Cookson, Richard; Tsuchiya, Aki; Ali, Shehzad

    2017-10-01

    Health inequality aversion parameters can be used to represent alternative value judgements about policy concern for reducing health inequality versus improving total health. In this study, we use data from an online survey of the general public in England (n = 244) to elicit health inequality aversion parameters for both Atkinson and Kolm social welfare functions. We find median inequality aversion parameters of 10.95 for Atkinson and 0.15 for Kolm. These values suggest substantial concern for health inequality among the English general public which, at current levels of quality adjusted life expectancy, implies weighting health gains to the poorest fifth of people in society six to seven times as highly as health gains to the richest fifth. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Communicating hands: ERPs elicited by meaningful symbolic hand postures.

    PubMed

    Gunter, Thomas C; Bach, Patric

    2004-11-30

    Meaningful and meaningless hand postures were presented to subjects who had to carry out a semantic discrimination task while electrical brain responses were recorded. Both meaningful and control sets of hand postures were matched as closely as possible. The ERPs elicited by meaningless hand postures showed an anteriorly distributed N300 and a centro-posteriorly distributed N400 component. The N300 probably reflects picture-specific processes, whereas the N400-effect probably reflects processing in an amodal semantic network. The scalp-distribution of the N400-effect, which is more posterior than usually reported in picture processing, suggests that the semantic representations of the concepts expressed by meaningful hand postures have similar properties to those of abstract words.

  7. Eye contact elicits bodily self-awareness in human adults.

    PubMed

    Baltazar, Matias; Hazem, Nesrine; Vilarem, Emma; Beaucousin, Virginie; Picq, Jean-Luc; Conty, Laurence

    2014-10-01

    Eye contact is a typical human behaviour known to impact concurrent or subsequent cognitive processing. In particular, it has been suggested that eye contact induces self-awareness, though this has never been formally proven. Here, we show that the perception of a face with a direct gaze (that establishes eye contact), as compared to either a face with averted gaze or a mere fixation cross, led adult participants to rate more accurately the intensity of their physiological reactions induced by emotional pictures. Our data support the view that bodily self-awareness becomes more acute when one is subjected to another's gaze. Importantly, this effect was not related to a particular arousal state induced by eye contact perception. Rejecting the arousal hypothesis, we suggest that eye contact elicits a self-awareness process by enhancing self-focused attention in humans. We further discuss the implications of this proposal. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Some properties of probability inversion algorithms to elicit expert opinion.

    NASA Astrophysics Data System (ADS)

    Lark, Murray

    2015-04-01

    Probability inversion methods have been developed to infer underlying expert utility functions from rankings that experts offer of subsets of scenarios. The method assumes that the expert ranking reflects an underlying utility, which can be modelled as a function of predictive covariates. This is potentially useful as a method for the extraction of expert opinions for prediction in new scenarios. Two particular algorithms are considered here, the IPF algorithm and the PURE algorithm. The former always converges for consistent sets of rankings and finds a solution which minimizes the mutual information of the estimated utilities and an initial random sample of proposed utilities drawn in the algorithm. In this poster I report some empirical studies on the probability inversion procedure, investigating the effects of the size of the expert panel, the consistency and quality of the expert panel and the validity of the predictive covariates. These results have practical implications for the design of elicitation by probability inversion methods.

  9. Small‐molecule elicitation of microbial secondary metabolites

    PubMed Central

    Pettit, Robin K.

    2011-01-01

    Summary Microbial natural products continue to be an unparalleled resource for pharmaceutical lead discovery, but the rediscovery rate is high. Bacterial and fungal sequencing studies indicate that the biosynthetic potential of many strains is much greater than that observed by fermentation. Prodding the expression of such silent (cryptic) pathways will allow us to maximize the chemical diversity available from microorganisms. Cryptic metabolic pathways can be accessed in the laboratory using molecular or cultivation‐based approaches. A targeted approach related to cultivation‐based methods is the application of small‐molecule elicitors to specifically affect transcription of secondary metabolite gene clusters. With the isolation of the novel secondary metabolites lunalides A and B, oxylipins, cladochromes F and G, nygerone A, chaetoglobosin‐542, ‐540 and ‐510, sphaerolone, dihydrosphaerolone, mutolide and pestalone, and the enhanced production of known secondary metabolites like penicillin and bacitracin, chemical elicitation is proving to be an effective way to augment natural product libraries. PMID:21375710

  10. Inflectional morphology in primary progressive aphasia: an elicited production study.

    PubMed

    Wilson, Stephen M; Brandt, Temre H; Henry, Maya L; Babiak, Miranda; Ogar, Jennifer M; Salli, Chelsey; Wilson, Lisa; Peralta, Karen; Miller, Bruce L; Gorno-Tempini, Maria Luisa

    2014-09-01

    Inflectional morphology lies at the intersection of phonology, syntax and the lexicon, three language domains that are differentially impacted in the three main variants of primary progressive aphasia (PPA). To characterize spared and impaired aspects of inflectional morphology in PPA, we elicited inflectional morphemes in 48 individuals with PPA and 13 healthy age-matched controls. We varied the factors of regularity, frequency, word class, and lexicality, and used voxel-based morphometry to identify brain regions where atrophy was predictive of deficits on particular conditions. All three PPA variants showed deficits in inflectional morphology, with the specific nature of the deficits dependent on the anatomical and linguistic features of each variant. Deficits in inflecting low-frequency irregular words were associated with semantic PPA, with lexical/semantic deficits, and with left temporal atrophy. Deficits in inflecting pseudowords were associated with non-fluent/agrammatic and logopenic variants, with phonological deficits, and with left frontal and parietal atrophy.

  11. Elicitation: a tool for enriching the bioactive composition of foods.

    PubMed

    Baenas, Nieves; García-Viguera, Cristina; Moreno, Diego A

    2014-09-01

    Elicitation is a good strategy to induce physiological changes and stimulate defense or stress-induced responses in plants. The elicitor treatments trigger the synthesis of phytochemical compounds in fruits, vegetables and herbs. These metabolites have been widely investigated as bioactive compounds responsible of plant cell adaptation to the environment, specific organoleptic properties of foods, and protective effects in human cells against oxidative processes in the development of neurodegenerative and cardiovascular diseases and certain types of cancer. Biotic (biological origin), abiotic (chemical or physical origin) elicitors and phytohormones have been applied alone or in combinations, in hydroponic solutions or sprays, and in different selected time points of the plant growth or during post-harvest. Understanding how plant tissues and their specific secondary metabolic pathways respond to specific treatments with elicitors would be the basis for designing protocols to enhance the production of secondary metabolites, in order to produce quality and healthy fresh foods.

  12. Inflectional morphology in primary progressive aphasia: An elicited production study

    PubMed Central

    Wilson, Stephen M.; Brandt, Temre H.; Henry, Maya L.; Babiak, Miranda; Ogar, Jennifer M.; Salli, Chelsey; Wilson, Lisa; Peralta, Karen; Miller, Bruce L.; Gorno-Tempini, Maria Luisa

    2014-01-01

    Inflectional morphology lies at the intersection of phonology, syntax and the lexicon, three language domains that are differentially impacted in the three main variants of primary progressive aphasia (PPA). To characterize spared and impaired aspects of inflectional morphology in PPA, we elicited inflectional morphemes in 48 individuals with PPA and 13 healthy age-matched controls. We varied the factors of regularity, frequency, word class, and lexicality, and used voxel-based morphometry to identify brain regions where atrophy was predictive of deficits on particular conditions. All three PPA variants showed deficits in inflectional morphology, with the specific nature of the deficits dependent on the anatomical and linguistic features of each variant. Deficits in inflecting low-frequency irregular words were associated with semantic PPA, with lexical/semantic deficits, and with left temporal atrophy. Deficits in inflecting pseudowords were associated with non-fluent/agrammatic and logopenic variants, with phonological deficits, and with left frontal and parietal atrophy. PMID:25129631

  13. A novel mimetic antigen eliciting protective antibody to Neisseria meningitidis.

    PubMed

    Granoff, D M; Moe, G R; Giuliani, M M; Adu-Bobie, J; Santini, L; Brunelli, B; Piccinetti, F; Zuno-Mitchell, P; Lee, S S; Neri, P; Bracci, L; Lozzi, L; Rappuoli, R

    2001-12-01

    Molecular mimetic Ags are of considerable interest as vaccine candidates. Yet there are few examples of mimetic Ags that elicit protective Ab against a pathogen, and the functional activity of anti-mimetic Abs has not been studied in detail. As part of the Neisseria meningitidis serogroup B genome sequencing project, a large number of novel proteins were identified. Herein, we provide evidence that genome-derived Ag 33 (GNA33), a lipoprotein with homology to Escherichia coli murein transglycosylase, elicits protective Ab to meningococci as a result of mimicking an epitope on loop 4 of porin A (PorA) in strains with serosubtype P1.2. Epitope mapping of a bactericidal anti-GNA33 mAb using overlapping peptides shows that the mAb recognizes peptides from GNA33 and PorA that share a QTP sequence that is necessary but not sufficient for binding. By flow cytometry, mouse antisera prepared against rGNA33 and the anti-GNA33 mAb bind as well as an anti-PorA P1.2 mAb to the surface of eight of nine N. meningitidis serogroup B strains tested with the P1.2 serosubtype. Anti-GNA33 Abs also are bactericidal for most P1.2 strains and, for susceptible strains, the activity of an anti-GNA33 mAb is similar to that of an anticapsular mAb but less active than an anti-P1.2 mAb. Anti-GNA Abs also confer passive protection against bacteremia in infant rats challenged with P1.2 strains. Thus, GNA33 represents one of the most effective immunogenic mimetics yet described. These results demonstrate that molecular mimetics have potential as meningococcal vaccine candidates.

  14. Knowledge elicitation techniques and application to nuclear plant maintenance

    NASA Astrophysics Data System (ADS)

    Doyle, E. Kevin

    The new millennium has brought with it the opportunity of global trade which in turn requires the utmost in efficiency from each individual industry. This includes the nuclear power industry, a point which was emphasized when the electrical generation industry began to be de regulated across North America the late 1990s and re-emphasized when the northeast power grid of North America collapsed in the summer of 2003. This dissertation deals with reducing the cost of the maintenance function of Candu nuclear power plants and initiating a strong link between universities and the Canadian nuclear industry. Various forms of RCM (reliability-centred maintenance) have been the tools of choice in industry for improving the maintenance function during the last 20 years. In this project, pilot studies, conducted at Bruce Power between 1999 and 2005, and reported on in this dissertation, lay out a path to implement statistical improvements as the next step after RCM in reducing the cost of the maintenance. Elicitation protocols, designed for the age group being elicited, address the much-documented issue of a lack of data. Clear, graphical, inferential statistical interfaces are accentuated and developed to aid in building the teams required to implement the various methodologies and to help in achieving funding targets. Graphical analysis and Crow/AMSAA (army materials systems analysis activity) plots are developed and demonstrated from the point of view of justifying the expenditures of cost reduction efforts. This dissertation ultimately speaks to the great opportunity being presented by this approach at this time: of capturing the baby-boom generation's huge pool of knowledge before those people retire. It is expected that the protocols and procedures referenced here will have applicability across the many disciplines where collecting expert information from a similar age group is required.

  15. Evaluating Residents' Readiness to Elicit Advance Care Plans

    PubMed Central

    Levy, Deborah; Strand, Jacob; McMahon, Graham T.

    2015-01-01

    Background Trainees are responsible for conducting advance care discussions but are often stressed by this role. Objective We developed an instrument to determine whether residents could identify a clinical scenario that necessitated an examination of a patient's goals and preferences as they pertain to clinical care, and subsequently measured their readiness to engage in such discussions. Methods Participants responded verbally to open-ended case presentations and completed survey items. We scored responses according to proximity to idealized answers. Results The sample consisted of 44 internal medicine residents, 12 students, 5 hospitalists, and 3 palliative care attendings, all of whom volunteered for the study and participated in standard interviews. Residents had widely varying scores (range 0–12, maximum score of 15) on the scored open response items. For eliciting values, mean score increased with training, and students, trainees, and attending physicians had mean scores of 3.7, 5.7, and 8.7, respectively (P = .01). For recommending care, mean scores were 3.0, 6.5, and 9.3, respectively (P < .001). Scores were correlated closely with increasing clinical experience and inversely with self-reported stress when conducting a goals-of-care discussion. The Kuder-Richardson Formula 20 reliability for the instrument was 0.52. Interrater reliability for sections about eliciting and recommending care were 0.64 (P < .001) and 0.50 (P < .001), respectively. The 1-week test-retest reliability was 0.91 for open response items and 0.76 for Likert responses. Conclusions A verbally administered instrument can readily and rapidly characterize a trainee's readiness to participate in advance care planning with patients. PMID:26457140

  16. Outer membrane vesicles displaying engineered glycotopes elicit protective antibodies.

    PubMed

    Chen, Linxiao; Valentine, Jenny L; Huang, Chung-Jr; Endicott, Christine E; Moeller, Tyler D; Rasmussen, Jed A; Fletcher, Joshua R; Boll, Joseph M; Rosenthal, Joseph A; Dobruchowska, Justyna; Wang, Zhirui; Heiss, Christian; Azadi, Parastoo; Putnam, David; Trent, M Stephen; Jones, Bradley D; DeLisa, Matthew P

    2016-06-28

    The O-antigen polysaccharide (O-PS) component of lipopolysaccharides on the surface of gram-negative bacteria is both a virulence factor and a B-cell antigen. Antibodies elicited by O-PS often confer protection against infection; therefore, O-PS glycoconjugate vaccines have proven useful against a number of different pathogenic bacteria. However, conventional methods for natural extraction or chemical synthesis of O-PS are technically demanding, inefficient, and expensive. Here, we describe an alternative methodology for producing glycoconjugate vaccines whereby recombinant O-PS biosynthesis is coordinated with vesiculation in laboratory strains of Escherichia coli to yield glycosylated outer membrane vesicles (glycOMVs) decorated with pathogen-mimetic glycotopes. Using this approach, glycOMVs corresponding to eight different pathogenic bacteria were generated. For example, expression of a 17-kb O-PS gene cluster from the highly virulent Francisella tularensis subsp. tularensis (type A) strain Schu S4 in hypervesiculating E. coli cells yielded glycOMVs that displayed F. tularensis O-PS. Immunization of BALB/c mice with glycOMVs elicited significant titers of O-PS-specific serum IgG antibodies as well as vaginal and bronchoalveolar IgA antibodies. Importantly, glycOMVs significantly prolonged survival upon subsequent challenge with F. tularensis Schu S4 and provided complete protection against challenge with two different F. tularensis subsp. holarctica (type B) live vaccine strains, thereby demonstrating the vaccine potential of glycOMVs. Given the ease with which recombinant glycotopes can be expressed on OMVs, the strategy described here could be readily adapted for developing vaccines against many other bacterial pathogens.

  17. Outer membrane vesicles displaying engineered glycotopes elicit protective antibodies

    PubMed Central

    Valentine, Jenny L.; Huang, Chung-Jr; Endicott, Christine E.; Moeller, Tyler D.; Rasmussen, Jed A.; Fletcher, Joshua R.; Boll, Joseph M.; Rosenthal, Joseph A.; Dobruchowska, Justyna; Wang, Zhirui; Heiss, Christian; Azadi, Parastoo; Putnam, David; Trent, M. Stephen; Jones, Bradley D.; DeLisa, Matthew P.

    2016-01-01

    The O-antigen polysaccharide (O-PS) component of lipopolysaccharides on the surface of gram-negative bacteria is both a virulence factor and a B-cell antigen. Antibodies elicited by O-PS often confer protection against infection; therefore, O-PS glycoconjugate vaccines have proven useful against a number of different pathogenic bacteria. However, conventional methods for natural extraction or chemical synthesis of O-PS are technically demanding, inefficient, and expensive. Here, we describe an alternative methodology for producing glycoconjugate vaccines whereby recombinant O-PS biosynthesis is coordinated with vesiculation in laboratory strains of Escherichia coli to yield glycosylated outer membrane vesicles (glycOMVs) decorated with pathogen-mimetic glycotopes. Using this approach, glycOMVs corresponding to eight different pathogenic bacteria were generated. For example, expression of a 17-kb O-PS gene cluster from the highly virulent Francisella tularensis subsp. tularensis (type A) strain Schu S4 in hypervesiculating E. coli cells yielded glycOMVs that displayed F. tularensis O-PS. Immunization of BALB/c mice with glycOMVs elicited significant titers of O-PS–specific serum IgG antibodies as well as vaginal and bronchoalveolar IgA antibodies. Importantly, glycOMVs significantly prolonged survival upon subsequent challenge with F. tularensis Schu S4 and provided complete protection against challenge with two different F. tularensis subsp. holarctica (type B) live vaccine strains, thereby demonstrating the vaccine potential of glycOMVs. Given the ease with which recombinant glycotopes can be expressed on OMVs, the strategy described here could be readily adapted for developing vaccines against many other bacterial pathogens. PMID:27274048

  18. Nest sanitation elicits egg discrimination in cuckoo hosts.

    PubMed

    Yang, Canchao; Chen, Min; Wang, Longwu; Liang, Wei; Møller, Anders Pape

    2015-11-01

    Nest sanitation is a nearly universal behavior in birds, while egg discrimination is a more specific adaptation that has evolved to counter brood parasitism. These two behaviors are closely related with nest sanitation being the ancestral behavior, and it has been hypothesized to constitute a preadaptation for egg discrimination. However, previous studies found little evidence to support this hypothesis. Here, we conducted an empirical test of the association between nest sanitation and egg discrimination in the barn swallow (Hirundo rustica) by inserting a single non-mimetic model egg or a non-mimetic model egg plus half a peanut shell into host nests. Compared to the rejection rate of single model eggs, barn swallows significantly increased egg rejection frequency if a half peanut shell was simultaneously introduced. Our result for the first time shows the impact of nest sanitation on egg discrimination and demonstrates that nest sanitation can elicit egg discrimination in hosts of brood parasites. This study provided evidence for nest sanitation being a preadaptation to egg discrimination by facilitating egg rejection, thereby significantly advancing our understanding of avian cognition of foreign objects. Furthermore, we suggest that egg discrimination behavior in many accepters and intermediate rejecters may be lost or diluted. Such egg discrimination can be elicited and restored after nest sanitation, implying a sensitive and rapid phenotypic response to increased risk of parasitism. Our study offers a novel perspective for investigating the role of so-called intermediate rejecter individuals or species in the long-term coevolutionary cycle between brood parasites and their hosts.

  19. Tactile stimulation of the oropharynx elicits sympathoexcitation in conscious humans

    PubMed Central

    Muller, Matthew D.; Mast, Jessica L.; Cui, Jian; Heffernan, Matthew J.; McQuillan, Patrick M.

    2013-01-01

    Tactile stimulation of the oropharynx (TSO) elicits the gag reflex and increases heart rate (HR) and mean arterial pressure (MAP) in anesthetized patients. However, the interaction between upper-airway defense reflexes and the sympathetic nervous system has not been investigated in conscious humans. In Experiment 1, beat-by-beat measurements of HR, MAP, muscle sympathetic nerve activity (MSNA), and renal vascular resistance (RVR) were measured during TSO and tactile stimulation of the hard palate (Sham) in the supine posture. In Experiment 2, TSO was performed before (pre) and after (post) inhalation of 4% lidocaine via nebulizer. Rate pressure product (RPP) was determined. Compared with Sham, TSO elicited the gag reflex and increased RPP [absolute change (Δ)36 ± 6 vs. 17 ± 5%], MSNA (Δ122 ± 39 vs. 19 ± 19%), and RVR (Δ55 ± 11 vs. 4 ± 4%). This effect occurred within one to two cardiac cycles of TSO. The ΔMAP (12 ± 3 vs. 6 ± 1 mmHg) and the ΔHR (10 ± 3 vs. 3 ± 3 beats/min) were also greater following TSO compared with Sham. Lidocaine inhalation blocked the gag reflex and attenuated increases in MAP (Δpre: 16 ± 2; Δpost: 5 ± 2 mmHg) and HR (Δpre: 12 ± 3; Δpost: 2 ± 2 beats/min) in response to TSO. When mechanically stimulated, afferents in the oropharynx not only serve to protect the airway but also cause reflex increases in MSNA, RVR, MAP, and HR. An augmented sympathoexcitatory response during intubation and laryngoscopy may contribute to perioperative cardiovascular morbidity and mortality. PMID:23599399

  20. Cripto-1 vaccination elicits protective immunity against metastatic melanoma.

    PubMed

    Ligtenberg, M A; Witt, K; Galvez-Cancino, F; Sette, A; Lundqvist, A; Lladser, A; Kiessling, R

    2016-05-01

    Metastatic melanoma is a fatal disease that responds poorly to classical treatments but can be targeted by T cell-based immunotherapy. Cancer vaccines have the potential to generate long-lasting cytotoxic CD8(+) T cell responses able to eradicate established and disseminated tumors. Vaccination against antigens expressed by tumor cells with enhanced metastatic potential represents a highly attractive strategy to efficiently target deadly metastatic disease. Cripto-1 is frequently over-expressed in human carcinomas and melanomas, but is expressed only at low levels on normal differentiated tissues. Cripto-1 is particularly upregulated in cancer-initiating cells and is involved in cellular processes such as cell migration, invasion and epithelial-mesenchymal transition, which are hallmarks of aggressive cancer cells able to initiate metastatic disease. Here, we explored the potential of Cripto-1 vaccination to target metastatic melanoma in a preclinical model. Cripto-1 was overexpressed in highly metastatic B16F10 cells as compared to poorly metastatic B16F1 cells. Moreover, B16F10 cells grown in sphere conditions to enrich for cancer stem cells (CSC) progressively upregulated cripto1 expression. Vaccination of C57Bl/6 mice with a DNA vaccine encoding mouse Cripto-1 elicited a readily detectable/strong cytotoxic CD8(+) T cell response specific for a H-2 Kb-restricted epitope identified based on its ability to bind H-2(b) molecules. Remarkably, Cripto-1 vaccination elicited a protective response against lung metastasis and subcutaneous challenges with highly metastatic B16F10 melanoma cells. Our data indicate that vaccination against Cripto-1 represents a novel strategy to be tested in the clinic.

  1. Cripto-1 vaccination elicits protective immunity against metastatic melanoma

    PubMed Central

    Ligtenberg, M. A.; Witt, K.; Galvez-Cancino, F.; Sette, A.; Lundqvist, A.; Lladser, A.; Kiessling, R.

    2016-01-01

    ABSTRACT Metastatic melanoma is a fatal disease that responds poorly to classical treatments but can be targeted by T cell-based immunotherapy. Cancer vaccines have the potential to generate long-lasting cytotoxic CD8+ T cell responses able to eradicate established and disseminated tumors. Vaccination against antigens expressed by tumor cells with enhanced metastatic potential represents a highly attractive strategy to efficiently target deadly metastatic disease. Cripto-1 is frequently over-expressed in human carcinomas and melanomas, but is expressed only at low levels on normal differentiated tissues. Cripto-1 is particularly upregulated in cancer-initiating cells and is involved in cellular processes such as cell migration, invasion and epithelial–mesenchymal transition, which are hallmarks of aggressive cancer cells able to initiate metastatic disease. Here, we explored the potential of Cripto-1 vaccination to target metastatic melanoma in a preclinical model. Cripto-1 was overexpressed in highly metastatic B16F10 cells as compared to poorly metastatic B16F1 cells. Moreover, B16F10 cells grown in sphere conditions to enrich for cancer stem cells (CSC) progressively upregulated cripto1 expression. Vaccination of C57Bl/6 mice with a DNA vaccine encoding mouse Cripto-1 elicited a readily detectable/strong cytotoxic CD8+ T cell response specific for a H-2 Kb-restricted epitope identified based on its ability to bind H-2b molecules. Remarkably, Cripto-1 vaccination elicited a protective response against lung metastasis and subcutaneous challenges with highly metastatic B16F10 melanoma cells. Our data indicate that vaccination against Cripto-1 represents a novel strategy to be tested in the clinic. PMID:27467944

  2. Eliciting regret improves decision making at the end of life.

    PubMed

    Djulbegovic, Benjamin; Tsalatsanis, Athanasios; Mhaskar, Rahul; Hozo, Iztok; Miladinovic, Branko; Tuch, Howard

    2016-11-01

    Management choices at the end of life are high-stake decisions fraught with emotions, chief among is regret. Our objective in this paper is to test the utility of a regret-based model to facilitate referral to hospice care while helping patients clarify their preferences on how they wish to spend the remaining days of their lives. A prospective cohort study that enrolled consecutive adult patients (n = 178) aware of the terminal nature of their disease. The patients were at the point in care where they had to decide between continuing potentially 'curative/life-prolonging' treatment (Rx) versus hospice care. Preferences were elicited using a Dual Visual Analog Scale regarding the level of regret of omission versus commission (RgO/RgC) towards hospice care and Rx. Each patient's RgO/RgC was contrasted against the predictive probability of death to suggest a management plan, which was then compared with the patient's actual choice. The probability of death was estimated using validated Palliative Performance Scale predictive model. Eighty-five percent (151/178) of patients agreed with the model's recommendations (p < 0.000001). Model predicted the actual choices for 72% (128/178) of patients (p < 0.00001). Logistic regression analysis showed that people who were initially inclined to be referred to hospice and were predicted to choose hospice over disease-directed treatment by the regret model have close to 98% probability of choosing hospice care at the end of their lives. No other factors (age, gender, race, educational status and pain level) affected their choice. Using regret to elicit choices in the end-of-life setting is both descriptively and prescriptively valid. People with terminal disease who are initially inclined to choose hospice and do not regret such a choice will select hospice care with high level of certainty. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  3. Expert Elicitations of 2100 Emission of CO2

    NASA Astrophysics Data System (ADS)

    Ho, Emily; Bosetti, Valentina; Budescu, David; Keller, Klaus; van Vuuren, Detlef

    2017-04-01

    Emission scenarios such as Shared Socioeconomic Pathways (SSPs) and Representative Concentration Pathways (RCPs) are used intensively for climate research (e.g. climate change projections) and policy analysis. While the range of these scenarios provides an indication of uncertainty, these scenarios are typically not associated with probability values. Some studies (e.g. Vuuren et al, 2007; Gillingham et al., 2015) took a different approach associating baseline emission pathways (conditionally) with probability distributions. This paper summarizes three studies where climate change experts were asked to conduct pair-wise comparisons of possible ranges of 2100 greenhouse gas emissions and rate the relative likelihood of the ranges. The elicitation was performed under two sets of assumptions: 1) a situation where no climate policies are introduced beyond the ones already in place (baseline scenario), and 2) a situation in which countries have ratified the voluntary policies in line with the long term target embedded in the 2015 Paris Agreement. These indirect relative judgments were used to construct subjective cumulative distribution functions. We show that by using a ratio scaling method that invokes relative likelihoods of scenarios, a subjective probability distribution can be derived for each expert that expresses their beliefs in the projected greenhouse gas emissions range in 2100. This method is shown to elicit stable estimates that require minimal adjustment and is relatively invariant to the partition of the domain of interest. Experts also rated the method as being easy and intuitive to use. We also report results of a study that allowed participants to choose their own ranges of greenhouse gas emissions to remove potential anchoring bias. We discuss the implications of the use of this method for facilitating comparison and communication of beliefs among diverse users of climate science research.

  4. EETs Elicit Direct Increases in Pulmonary Arterial Pressure in Mice

    PubMed Central

    Kandhi, Sharath; Froogh, Ghezal; Qin, Jun; Luo, Meng; Wolin, Michael S.; Huang, An

    2016-01-01

    OBJECTIVE The biological role of epoxyeicosatrienoic acids (EETs) in the regulation of pulmonary circulation is currently under debate. We hypothesized that EETs initiate increases in right ventricular systolic pressure (RVSP) via perhaps, pulmonary vasoconstriction. METHODS Mice were anesthetized with isoflurane. Three catheters, inserted into the left jugular vein, the left carotid artery, and the right jugular vein, were used for infusing EETs, monitoring blood pressure (BP), and RVSP respectively. BP and RVSP were continuously recorded at basal conditions, in response to administration of 4 regioisomeric EETs (5,6-EET; 8,9-EET; 11,12-EET, and 14,15-EET; 1, 2, 5 and 10ng/g body weight (BW) for each EET), and during exposure of mice to hypoxia. RESULTS All 4 EETs initiated dose-dependent increases in RVSP, though reduced BP. 11,12-EET elicited the greatest increment in RVSP among all EET isoforms. To clarify the direct elevation of RVSP in a systemic BP-independent manner, equivalent amounts of 14,15-EET were injected over 1 and 2 minutes respectively. One-minute injection of 14,15-EET elicited significantly faster and greater increases in RVSP than the 2-minute injection, whereas their BP changes were comparable. Additionally, direct injection of low doses of 14,15-EET (0.1, 0.2, 0.5, and 1ng/g BW) into the right ventricle caused significant increases in RVSP without effects on BP, confirming that systemic vasodilation-induced increases in venous return are not the main cause for the increased RVSP. Acute exposure of mice to hypoxia significantly elevated RVSP, as well as 14,15-EET-induced increases in RVSP. CONCLUSIONS EETs directly elevate RVSP, a response that may play an important role in the development of hypoxia-induced pulmonary hypertension (PH). PMID:26304959

  5. Promoting environmental sustainability via an expert elicitation process

    SciTech Connect

    Swor, Tom; Canter, Larry

    2011-09-15

    Environmental sustainability (ES) planning was applied to the 981-mile, commercially navigable Ohio River. Navigation improvement needs were identified within the broad study along with actions to restore aquatic and riparian ecological resources to a higher state of sustainability. The actions were identified via an Expert Elicitation Process (EEP) involving aquatic and riparian/terrestrial experts knowledgeable of Ohio River resources. The received information was synthesized into goals for the selected resources (Valued Ecosystem Components - or VECs), actions or measures to attain the goals, and monitoring to evaluate conditions. Finally, 26 types of ES actions were identified and classified into three ES alternatives. These alternatives were then evaluated relative to key decision criteria, and such evaluations, based on pertinent decision criteria, were also conducted for four navigation improvement alternatives. Finally, the best combination of ES and navigation alternatives was identified. The key lessons derived from this use of EEP were that: (1) EEP can support the preliminary identification of ES measures; however, more detailed study of specific designs and cost evaluations will be necessary; (2) the method promotes collaboration between key scientists and policymakers from governmental agencies and private sectors, and such collaboration will ultimately provide the foundation for implementation of sustainability actions; and (3) an effective EEP does not occur by accident, it requires careful planning, implementation, and documentation. - Research Highlights: > Use of an Expert Elicitation Process (EEP) is demonstrated in this study. > EEP was used to identify Environmental Sustainability (ES) needs for the Ohio River. > EEP helped develop consensus among resource experts on ES needs. > EEP promotes collaboration to identify and contribute to common resource goals. > EEP may be used in assessing cumulative effects and formulating restoration plans.

  6. Outer membrane vesicles displaying engineered glycotopes elicit protective antibodies

    DOE PAGES

    Chen, Linxiao; Valentine, Jenny L.; Huang, Chung-Jr; ...

    2016-06-06

    The O-antigen polysaccharide (O-PS) component of lipopolysaccharides on the surface of gram-negative bacteria is both a virulence factor and a B-cell antigen. Antibodies elicited by O-PS often confer protection against infection; therefore, O-PS glycoconjugate vaccines have proven useful against a number of different pathogenic bacteria. However, conventional methods for natural extraction or chemical synthesis of O-PS are technically demanding, inefficient, and expensive. In this paper, we describe an alternative methodology for producing glycoconjugate vaccines whereby recombinant O-PS biosynthesis is coordinated with vesiculation in laboratory strains of Escherichia coli to yield glycosylated outer membrane vesicles (glycOMVs) decorated with pathogen-mimetic glycotopes. Usingmore » this approach, glycOMVs corresponding to eight different pathogenic bacteria were generated. For example, expression of a 17-kb O-PS gene cluster from the highly virulent Francisella tularensis subsp. tularensis (type A) strain Schu S4 in hypervesiculating E. coli cells yielded glycOMVs that displayed F. tularensis O-PS. Immunization of BALB/c mice with glycOMVs elicited significant titers of O-PS–specific serum IgG antibodies as well as vaginal and bronchoalveolar IgA antibodies. Importantly, glycOMVs significantly prolonged survival upon subsequent challenge with F. tularensis Schu S4 and provided complete protection against challenge with two different F. tularensis subsp. holarctica (type B) live vaccine strains, thereby demonstrating the vaccine potential of glycOMVs. Finally, given the ease with which recombinant glycotopes can be expressed on OMVs, the strategy described here could be readily adapted for developing vaccines against many other bacterial pathogens.« less

  7. Activation of the thrombopoietin receptor by mutant calreticulin in CALR-mutant myeloproliferative neoplasms.

    PubMed

    Araki, Marito; Yang, Yinjie; Masubuchi, Nami; Hironaka, Yumi; Takei, Hiraku; Morishita, Soji; Mizukami, Yoshihisa; Kan, Shin; Shirane, Shuichi; Edahiro, Yoko; Sunami, Yoshitaka; Ohsaka, Akimichi; Komatsu, Norio

    2016-03-10

    Recurrent somatic mutations of calreticulin (CALR) have been identified in patients harboring myeloproliferative neoplasms; however, their role in tumorigenesis remains elusive. Here, we found that the expression of mutant but not wild-type CALR induces the thrombopoietin (TPO)-independent growth of UT-7/TPO cells. We demonstrated that c-MPL, the TPO receptor, is required for this cytokine-independent growth of UT-7/TPO cells. Mutant CALR preferentially associates with c-MPL that is bound to Janus kinase 2 (JAK2) over the wild-type protein. Furthermore, we demonstrated that the mutant-specific carboxyl terminus portion of CALR interferes with the P-domain of CALR to allow the N-domain to interact with c-MPL, providing an explanation for the gain-of-function property of mutant CALR. We showed that mutant CALR induces the phosphorylation of JAK2 and its downstream signaling molecules in UT-7/TPO cells and that this induction was blocked by JAK2 inhibitor treatment. Finally, we demonstrated that c-MPL is required for TPO-independent megakaryopoiesis in induced pluripotent stem cell-derived hematopoietic stem cells harboring the CALR mutation. These findings imply that mutant CALR activates the JAK2 downstream pathway via its association with c-MPL. Considering these results, we propose that mutant CALR promotes myeloproliferative neoplasm development by activating c-MPL and its downstream pathway.

  8. Agravitropic mutants of the moss Ceratodon purpureus do not complement mutants having a reversed gravitropic response.

    PubMed

    Cove, David J; Quatrano, Ralph S

    2006-07-01

    New mutants of the moss Ceratodon purpureus have been isolated, which showed abnormal gravitropic responses. The apical cells of protonemal filaments of wild-type strains respond to gravity by growing upwards and are well aligned to the gravity vector. This response only occurs in darkness. Mutants show a range of phenotypes. Some are insensitive to gravity, showing symmetrical growth, while others align to the gravity vector but orient growth downwards. A further class grows in darkness as though it were in light, showing insensitivity to gravity and continued chlorophyll synthesis. Somatic hybrids between mutants and wild-type strains and between pairs of mutants have been selected using transgenic antibiotic resistance as selective markers. Hybrids between wild-type strains and all of the mutants have a wild-type phenotype, and so all mutants therefore have recessive phenotypes. Mutants comprise three complementation groups. One group has a single member, while another has three members. The third has at least 16 members and shows a complex pattern of complementation consistent with a single gene product functioning in both orientation and alignment to gravity, as well as contributing more than one subunit to the mature product.

  9. Genotyping-by-sequencing of glossy mutants

    USDA-ARS?s Scientific Manuscript database

    Glossy mutants are a common occurrence in Brassica oleracea L. and they have been documented in most crop varieties of the species including cabbage, kale, broccoli, and collard. Glossy phenotypes have been of particular interest to researchers due to observations that they influence insect behavior...

  10. Comprehensive transposon mutant library of Pseudomonas aeruginosa

    PubMed Central

    Jacobs, Michael A.; Alwood, Ashley; Thaipisuttikul, Iyarit; Spencer, David; Haugen, Eric; Ernst, Stephen; Will, Oliver; Kaul, Rajinder; Raymond, Christopher; Levy, Ruth; Chun-Rong, Liu; Guenthner, Donald; Bovee, Donald; Olson, Maynard V.; Manoil, Colin

    2003-01-01

    We have developed technologies for creating saturating libraries of sequence-defined transposon insertion mutants in which each strain is maintained. Phenotypic analysis of such libraries should provide a virtually complete identification of nonessential genes required for any process for which a suitable screen can be devised. The approach was applied to Pseudomonas aeruginosa, an opportunistic pathogen with a 6.3-Mbp genome. The library that was generated consists of 30,100 sequence-defined mutants, corresponding to an average of five insertions per gene. About 12% of the predicted genes of this organism lacked insertions; many of these genes are likely to be essential for growth on rich media. Based on statistical analyses and bioinformatic comparison to known essential genes in E. coli, we estimate that the actual number of essential genes is 300-400. Screening the collection for strains defective in two defined multigenic processes (twitching motility and prototrophic growth) identified mutants corresponding to nearly all genes expected from earlier studies. Thus, phenotypic analysis of the collection may produce essentially complete lists of genes required for diverse biological activities. The transposons used to generate the mutant collection have added features that should facilitate downstream studies of gene expression, protein localization, epistasis, and chromosome engineering. PMID:14617778

  11. Comprehensive transposon mutant library of Pseudomonas aeruginosa.

    PubMed

    Jacobs, Michael A; Alwood, Ashley; Thaipisuttikul, Iyarit; Spencer, David; Haugen, Eric; Ernst, Stephen; Will, Oliver; Kaul, Rajinder; Raymond, Christopher; Levy, Ruth; Chun-Rong, Liu; Guenthner, Donald; Bovee, Donald; Olson, Maynard V; Manoil, Colin

    2003-11-25

    We have developed technologies for creating saturating libraries of sequence-defined transposon insertion mutants in which each strain is maintained. Phenotypic analysis of such libraries should provide a virtually complete identification of nonessential genes required for any process for which a suitable screen can be devised. The approach was applied to Pseudomonas aeruginosa, an opportunistic pathogen with a 6.3-Mbp genome. The library that was generated consists of 30,100 sequence-defined mutants, corresponding to an average of five insertions per gene. About 12% of the predicted genes of this organism lacked insertions; many of these genes are likely to be essential for growth on rich media. Based on statistical analyses and bioinformatic comparison to known essential genes in E. coli, we estimate that the actual number of essential genes is 300-400. Screening the collection for strains defective in two defined multigenic processes (twitching motility and prototrophic growth) identified mutants corresponding to nearly all genes expected from earlier studies. Thus, phenotypic analysis of the collection may produce essentially complete lists of genes required for diverse biological activities. The transposons used to generate the mutant collection have added features that should facilitate downstream studies of gene expression, protein localization, epistasis, and chromosome engineering.

  12. Conformational stability of adrenodoxin mutant proteins.

    PubMed Central

    Burova, T. V.; Beckert, V.; Uhlmann, H.; Ristau, O.; Bernhardt, R.; Pfeil, W.

    1996-01-01

    Adrenodoxin and the mutants at the positions T54, H56, D76, Y82, and C95, as well as the deletion mutants 4-114 and 4-108, were studied by high-sensitivity scanning microcalorimetry, limited proteolysis, and absorption spectroscopy. The mutants show thermal transition temperatures ranging from 46 to 56 degrees C, enthalpy changes from 250 to 370 kJ/mol, and heat capacity change delta Cp = 7.28 +/- 0.67 kJ/mol/K, except H56R. The amino acid replacement H56R produces substantial local changes in the region around positions 56 and Y82, as indicated by reduced heat capacity change (delta Cp = 4.29 +/- 0.37 kJ/mol/K) and enhanced fluorescence. Deletion mutant 4-108 is apparently more stable than the wild type, as judged by higher specific denaturation enthalpy and resistance toward proteolytic degradation. No simple correlation between conformational stability and functional properties could be found. PMID:8880913

  13. Yeast mutants overproducing iso-cytochromes c

    SciTech Connect

    Sherman, F.; Cardillo, T.S.; Errede, B.; Friedman, L.; McKnight, G.; Stiles, J.I.

    1980-01-01

    For over 15 years, the iso-cytochrome c system in the yeast Saccharomyces cerevisiae has been used to investigate a multitude of problems in genetics and molecular biology. More recently, attention has been focused on using mutants for examining translation and transcriptional processes and for probing regulatory regions governing gene expression. In an effort to explore regulatory mechanisms and to investigate mutational alterations that lead to increased levels of gene products, we have isolated and characterized mutants that overproduce cytochrome c. In this paper we have briefly summarized background information of some essential features of the iso-cytochrome c system and we have described the types of mutants that overproduce iso-1-cytochrome c or iso-2-cytochrome c. Genetic procedures and recombinant DNA procedures were used to demonstrate that abnormally high amounts of gene products occur in mutants as result of duplications of gene copies or of extended alteration of regulatory regions. The results summarized in this paper point out the requirements of gross mutational changes or rearrangements of chromosomal segments for augmenting gene products.

  14. Nicotinamide ribosyl uptake mutants in Haemophilus influenzae.

    PubMed

    Herbert, Mark; Sauer, Elizabeta; Smethurst, Graeme; Kraiss, Anita; Hilpert, Anna-Karina; Reidl, Joachim

    2003-09-01

    The gene for the nicotinamide riboside (NR) transporter (pnuC) was identified in Haemophilus influenzae. A pnuC mutant had only residual NR uptake and could survive in vitro with high concentrations of NR, but could not survive in vivo. PnuC may represent a target for the development of inhibitors for preventing H. influenzae disease.

  15. Ethanol production using engineered mutant E. coli

    DOEpatents

    Ingram, Lonnie O.; Clark, David P.

    1991-01-01

    The subject invention concerns novel means and materials for producing ethanol as a fermentation product. Mutant E. coli are transformed with a gene coding for pyruvate decarboxylase activity. The resulting system is capable of producing relatively large amounts of ethanol from a variety of biomass sources.

  16. Phenotypic mutant library: potential for gene discovery

    USDA-ARS?s Scientific Manuscript database

    The rapid development of high throughput and affordable Next- Generation Sequencing (NGS) techniques has renewed interest in gene discovery using forward genetics. The conventional forward genetic approach starts with isolation of mutants with a phenotype of interest, mapping the mutation within a s...

  17. Novel Two-Step Hierarchical Screening of Mutant Pools Reveals Mutants under Selection in Chicks

    PubMed Central

    Yang, Hee-Jeong; Bogomolnaya, Lydia M.; Elfenbein, Johanna R.; Endicott-Yazdani, Tiana; Reynolds, M. Megan; Porwollik, Steffen; Cheng, Pui; Xia, Xiao-Qin

    2016-01-01

    Contaminated chicken/egg products are major sources of human salmonellosis, yet the strategies used by Salmonella to colonize chickens are poorly understood. We applied a novel two-step hierarchical procedure to identify new genes important for colonization and persistence of Salmonella enterica serotype Typhimurium in chickens. A library of 182 S. Typhimurium mutants each containing a targeted deletion of a group of contiguous genes (for a total of 2,069 genes deleted) was used to identify regions under selection at 1, 3, and 9 days postinfection in chicks. Mutants in 11 regions were under selection at all assayed times (colonization mutants), and mutants in 15 regions were under selection only at day 9 (persistence mutants). We assembled a pool of 92 mutants, each deleted for a single gene, representing nearly all genes in nine regions under selection. Twelve single gene deletion mutants were under selection in this assay, and we confirmed 6 of 9 of these candidate mutants via competitive infections and complementation analysis in chicks. STM0580, STM1295, STM1297, STM3612, STM3615, and STM3734 are needed for Salmonella to colonize and persist in chicks and were not previously associated with this ability. One of these key genes, STM1297 (selD), is required for anaerobic growth and supports the ability to utilize formate under these conditions, suggesting that metabolism of formate is important during infection. We report a hierarchical screening strategy to interrogate large portions of the genome during infection of animals using pools of mutants of low complexity. Using this strategy, we identified six genes not previously known to be needed during infection in chicks, and one of these (STM1297) suggests an important role for formate metabolism during infection. PMID:26857572

  18. Novel Two-Step Hierarchical Screening of Mutant Pools Reveals Mutants under Selection in Chicks.

    PubMed

    Yang, Hee-Jeong; Bogomolnaya, Lydia M; Elfenbein, Johanna R; Endicott-Yazdani, Tiana; Reynolds, M Megan; Porwollik, Steffen; Cheng, Pui; Xia, Xiao-Qin; McClelland, Michael; Andrews-Polymenis, Helene

    2016-04-01

    Contaminated chicken/egg products are major sources of human salmonellosis, yet the strategies used by Salmonella to colonize chickens are poorly understood. We applied a novel two-step hierarchical procedure to identify new genes important for colonization and persistence of Salmonella enterica serotype Typhimurium in chickens. A library of 182 S. Typhimurium mutants each containing a targeted deletion of a group of contiguous genes (for a total of 2,069 genes deleted) was used to identify regions under selection at 1, 3, and 9 days postinfection in chicks. Mutants in 11 regions were under selection at all assayed times (colonization mutants), and mutants in 15 regions were under selection only at day 9 (persistence mutants). We assembled a pool of 92 mutants, each deleted for a single gene, representing nearly all genes in nine regions under selection. Twelve single gene deletion mutants were under selection in this assay, and we confirmed 6 of 9 of these candidate mutants via competitive infections and complementation analysis in chicks. STM0580, STM1295, STM1297, STM3612, STM3615, and STM3734 are needed for Salmonella to colonize and persist in chicks and were not previously associated with this ability. One of these key genes, STM1297 (selD), is required for anaerobic growth and supports the ability to utilize formate under these conditions, suggesting that metabolism of formate is important during infection. We report a hierarchical screening strategy to interrogate large portions of the genome during infection of animals using pools of mutants of low complexity. Using this strategy, we identified six genes not previously known to be needed during infection in chicks, and one of these (STM1297) suggests an important role for formate metabolism during infection.

  19. GAMPMS: Genetic algorithm managed peptide mutant screening.

    PubMed

    Long, Thomas; McDougal, Owen M; Andersen, Tim

    2015-06-30

    The prominence of endogenous peptide ligands targeted to receptors makes peptides with the desired binding activity good molecular scaffolds for drug development. Minor modifications to a peptide's primary sequence can significantly alter its binding properties with a receptor, and screening collections of peptide mutants is a useful technique for probing the receptor-ligand binding domain. Unfortunately, the combinatorial growth of such collections can limit the number of mutations which can be explored using structure-based molecular docking techniques. Genetic algorithm managed peptide mutant screening (GAMPMS) uses a genetic algorithm to conduct a heuristic search of the peptide's mutation space for peptides with optimal binding activity, significantly reducing the computational requirements of the virtual screening. The GAMPMS procedure was implemented and used to explore the binding domain of the nicotinic acetylcholine receptor (nAChR) α3β2-isoform with a library of 64,000 α-conotoxin (α-CTx) MII peptide mutants. To assess GAMPMS's performance, it was compared with a virtual screening procedure that used AutoDock to predict the binding affinity of each of the α-CTx MII peptide mutants with the α3β2-nAChR. The GAMPMS implementation performed AutoDock simulations for as few as 1140 of the 64,000 α-CTx MII peptide mutants and could consistently identify a set of 10 peptides with an aggregated binding energy that was at least 98% of the aggregated binding energy of the 10 top peptides from the exhaustive AutoDock screening.

  20. N-acetylcysteine potentiates diclofenac toxicity in Saccharomyces cerevisiae: stronger potentiation in ABC transporter mutant strains.

    PubMed

    Al-Attrache, Houssein; Chamieh, Hala; Hamzé, Monzer; Morel, Isabelle; Taha, Samir; Abdel-Razzak, Ziad

    2017-05-15

    Diclofenac (DCF) adverse reactions involve diverse mechanisms in different models. We recently demonstrated that DCF-induced toxicity in HepaRG decreases as they express DCF-metabolizing enzymes. DCF metabolism promotes toxicity in Saccharomyces cerevisiae expressing heterologous cytochromes-P450. N-Acetylcysteine (NAC) is used to treat diverse medical conditions due to its multiple properties (antioxidant, metal chelator, thiol-disulfide disruption). The latter property accounts for its mucolytic effects and broadens its potential molecular targets to signal transduction proteins, ABC transporters and others. Interaction of NAC with DCF effects depends on the experimental model. This study aims to investigate NAC/DCF interaction and the involvement of ABC transporters in wild type and mutant Saccharomyces cerevisiae. DCF inhibited yeast growth in a dose- and time-dependent manner and the cells started adapting to DCF 24-h post-treatment. NAC potentiated DCF-induced toxicity if added prior or parallel to DCF. Pretreatment with NAC increased its potentiation effect and compromised cells adaption to DCF. Post-treatment with NAC potentiated DCF toxicity without compromising adaptation. Moreover, mutant strains in ABC transporters Pdr5, Yor1, Bpt1 or Pdr15, were more sensitive to DCF; while mutant strains in Pdr5, Vmr1 or Pdr12 were more sensitive to NAC/DCF interaction. DCF ± NAC elicited on the mutant strain in Yap1, an oxidative stress-related protein, the same effects as on the wild type. Therefore, oxidative stress does not seem to be key actor in DCF toxicity in our model. Our hypothesis is that NAC potentiation effect is at least due to its ability to disrupt disulfide bridge in proteins required to overcome DCF toxicity in yeast.

  1. Purification and characterization of a mutant DnaB protein specifically defective in ATP hydrolysis.

    PubMed Central

    Shrimankar, P; Stordal, L; Maurer, R

    1992-01-01

    The dnaB gene of Escherichia coli encodes an essential DNA replication enzyme. Fueled by the energy derived from the hydrolysis of ATP to ADP+P(i), this enzyme unwinds double-stranded DNA in advance of the DNA polymerase. While doing so, it intermittently stimulates primase to synthesize an RNA primer for an Okazaki fragment. To better understand the structural basis of these and other aspects of DnaB function, we have initiated a study of mutant DnaB proteins. Here, we report the purification and characterization of a mutant DnaB protein (RC231) containing cysteine in place of arginine at residue 231. The mutant protein attains a stable, properly folded structure that allows association of six promoters to form a hexamer, as is also true for wild-type DnaB. Further, the mutant protein interacts with ATP, the nonhydrolyzable ATP analog adenosine-5'-O-(3-thiotriphosphate) (ATP gamma S), ADP, and poly(dT), and it stimulates primase action. It is, however, profoundly deficient in ATP hydrolysis, helicase activity, and replication activity at the chromosomal origin of replication. In addition, while general priming reactions with wild-type DnaB and ATP elicited the synthesis of short primers, reactions with DnaB and ATP gamma S or with RC231 and either ATP or ATP gamma S stimulated the synthesis of significantly longer primers. On the basis of these observations, we suggest that primase interacts directly with DnaB throughout primer synthesis during general priming, until dissociation of DnaB from DNA or ATP hydrolysis by DnaB disrupts the interaction and leads to primer termination. Images PMID:1332941

  2. Superior triacylglycerol (TAG) accumulation in starchless mutants of Scenedesmus obliquus: (I) mutant generation and characterization

    PubMed Central

    2014-01-01

    Background Microalgae are a promising platform for producing neutral lipids, to be used in the application for biofuels or commodities in the feed and food industry. A very promising candidate is the oleaginous green microalga Scenedesmus obliquus, because it accumulates up to 45% w/w triacylglycerol (TAG) under nitrogen starvation. Under these conditions, starch is accumulated as well. Starch can amount up to 38% w/w under nitrogen starvation, which is a substantial part of the total carbon captured. When aiming for optimized TAG production, blocking the formation of starch could potentially increase carbon allocation towards TAG. In an attempt to increase TAG content, productivity and yield, starchless mutants of this high potential strain were generated using UV mutagenesis. Previous studies in Chlamydomonas reinhardtii have shown that blocking the starch synthesis yields higher TAG contents, although these TAG contents do not surpass those of oleaginous microalgae yet. So far no starchless mutants in oleaginous green microalgae have been isolated that result in higher TAG productivities. Results Five starchless mutants have been isolated successfully from over 3,500 mutants. The effect of the mutation on biomass and total fatty acid (TFA) and TAG productivity under nitrogen-replete and nitrogen-depleted conditions was studied. All five starchless mutants showed a decreased or completely absent starch content. In parallel, an increased TAG accumulation rate was observed for the starchless mutants and no substantial decrease in biomass productivity was perceived. The most promising mutant showed an increase in TFA productivity of 41% at 4 days after nitrogen depletion, reached a TAG content of 49.4% (% of dry weight) and had no substantial change in biomass productivity compared to the wild type. Conclusions The improved S. obliquus TAG production strains are the first starchless mutants in an oleaginous green microalga that show enhanced TAG content under

  3. Insights Learned from L457(3.43)R, an Activating Mutant of the Human Lutropin Receptor

    PubMed Central

    Latronico, Ana Claudia; Segaloff, Deborah L.

    2006-01-01

    The L457(3.43)R mutation of the hLHR was initially identified in a Brazilian boy with gonadotropin-independent precocious puberty. As would be expected, L457(3.43)R, when expressed in 293 cells, caused a marked elevation in basal cAMP levels. Interestingly, in spite of the fact that the elevated basal levels of cAMP elicited by L457R were not as great as those elicited by the wild-type hLHR when stimulated with hCG, L457(3.43)R cells were unresponsive to further hormonal stimulation. We have since determined that the L457(3.43)R mutant, as well as other constitutively active mutants of the hLHR, causes an increase in phosphodiesterase activity that attenuates the target cell to hormonal stimulation of the wild-type hLHR or other Gs-coupled GPCRs. We have also shown that the constitutive activity and lack of hormonal responsiveness of L457(3.43)R are due to the formation of a salt bridge between the introduced arginine in the mid portion of helix 3 with D578(6.44) in the mid portion of helix 6. The formation of this salt bridge results in the disruption of interactions between the cytoplasmic ends of helices 3 and 6 that are associated in general with activation of the hLHR. As such, this mutant has provided novel insights into the properties of target cells expressing activating hLHR mutants and into the structural basis for hLHR activation. PMID:17055147

  4. Application and Evaluation of an Expert Judgment Elicitation Procedure for Correlations

    PubMed Central

    Zondervan-Zwijnenburg, Mariëlle; van de Schoot-Hubeek, Wenneke; Lek, Kimberley; Hoijtink, Herbert; van de Schoot, Rens

    2017-01-01

    The purpose of the current study was to apply and evaluate a procedure to elicit expert judgments about correlations, and to update this information with empirical data. The result is a face-to-face group elicitation procedure with as its central element a trial roulette question that elicits experts' judgments expressed as distributions. During the elicitation procedure, a concordance probability question was used to provide feedback to the experts on their judgments. We evaluated the elicitation procedure in terms of validity and reliability by means of an application with a small sample of experts. Validity means that the elicited distributions accurately represent the experts' judgments. Reliability concerns the consistency of the elicited judgments over time. Four behavioral scientists provided their judgments with respect to the correlation between cognitive potential and academic performance for two separate populations enrolled at a specific school in the Netherlands that provides special education to youth with severe behavioral problems: youth with autism spectrum disorder (ASD), and youth with diagnoses other than ASD. Measures of face-validity, feasibility, convergent validity, coherence, and intra-rater reliability showed promising results. Furthermore, the current study illustrates the use of the elicitation procedure and elicited distributions in a social science application. The elicited distributions were used as a prior for the correlation, and updated with data for both populations collected at the school of interest. The current study shows that the newly developed elicitation procedure combining the trial roulette method with the elicitation of correlations is a promising tool, and that the results of the procedure are useful as prior information in a Bayesian analysis. PMID:28197115

  5. Assessing Risks from Emerging Contaminants: Using Expert Elicitation and Group Decisions

    DTIC Science & Technology

    2010-06-01

    Background on expert elicitation Phase I impact assessment process Identification of experts Elicitation methods Results Next steps 2 Expert Elicitation “a...Review literature, periodicals, regulatory communications, etc. Over -the- horizon Monitor events; Conduct Phase I qualitative impact assessment...Conduct Phase II quantitative impact assessment; develop & rank RMOs EC News Phase I Assessment Phase II Assessment Probable high DoD impacts Possible

  6. Analysis of Sporulation Mutants II. Mutants Blocked in the Citric Acid Cycle

    PubMed Central

    Fortnagel, Peter; Freese, Ernst

    1968-01-01

    Sporulation mutants that were unable to incorporate uracil during the developmental period recovered this capacity with the addition of ribose and in most cases with the addition of glutamate. Of the mutants that responded to both ribose and glumate, all but three also responded to citrate, and all but five responded to acetate. One of the exceptional strains was deficient in aconitase and another one in aconitase and isocitrate dehydrogenase; both required glutamate for growth. For the mutants which did not respond to glutamate, the products made from 14C-glutamate were determined by thin-layer chromatography. Significant differences were found which enabled the identification of mutant blocks. The deficiency of the corresponding enzyme activity was verified. Several mutants were deficient in α-ketoglutarate dehydrogenase, and one lacked succinic dehydrogenase. These mutants could still grow on glucose as sole carbon source, but not on glutamate. The intact Krebs cycle is therefore not required for vegetative growth of aerobic Bacillis subtilis, but it is indispensable for sporulation. Images PMID:4967197

  7. Amuvatinib has cytotoxic effects against NRAS-mutant melanoma but not BRAF-mutant melanoma.

    PubMed

    Fedorenko, Inna V; Fang, Bin; Koomen, John M; Gibney, Geoffrey T; Smalley, Keiran S M

    2014-10-01

    Effective targeted therapy strategies are still lacking for the 15-20% of melanoma patients whose melanomas are driven by oncogenic NRAS. Here, we report on the NRAS-specific behavior of amuvatinib, a kinase inhibitor with activity against c-KIT, Axl, PDGFRα, and Rad51. An analysis of BRAF-mutant and NRAS-mutant melanoma cell lines showed the NRAS-mutant cohort to be enriched for targets of amuvatinib, including Axl, c-KIT, and the Axl ligand Gas6. Increasing concentrations of amuvatinib selectively inhibited the growth of NRAS-mutant, but not BRAF-mutant melanoma cell lines, an effect associated with induction of S-phase and G2/M-phase cell cycle arrest and induction of apoptosis. Mechanistically, amuvatinib was noted to either inhibit Axl, AKT, and MAPK signaling or Axl and AKT signaling and to induce a DNA damage response. In three-dimensional cell culture experiments, amuvatinib was cytotoxic against NRAS-mutant melanoma cell lines. Thus, we show for the first time that amuvatinib has proapoptotic activity against melanoma cell lines, with selectivity observed for those harboring oncogenic NRAS.

  8. Diazepam blocks fear-enhanced startle elicited electrically from the brainstem.

    PubMed

    Berg, W K; Davis, M

    1984-02-01

    Startle-like responses were elicited electrically from the ventral cochlear nucleus (VCN) in darkness or in the presence of a light that had previously been paired with shocks. These startle-like responses were potentiated by the light and potentiation was selectively decreased by diazepam in a dose-related fashion (0.625 to 2.5 mg/kg). The benzodiazepine antagonist RO15-1788 attenuated the effect of diazepam. The data indicate that potentiation of electrically elicited startle behaves like acoustically elicited startle, providing further evidence that electrical elicitation of startle is a viable experimental technique.

  9. alpha Pix enhances mutant huntingtin aggregation.

    PubMed

    Eriguchi, Makoto; Mizuta, Haruo; Luo, Shouqing; Kuroda, Yasuo; Hara, Hideo; Rubinsztein, David C

    2010-03-15

    Huntington's disease is caused by polyglutamine-expanded mutant huntingtin (muhtt), an aggregation-prone protein. We identified the Pak-interacting exchange factor (alpha Pix/Cool2) as a novel huntingtin (htt) interacting protein, after screening actin-cytoskeleton organization-related factors. Using immunoprecipitation experiments, we show that alpha Pix binds to both the N-terminal of wild-type htt (wthtt) and mutant htt (muthtt). Colocalization studies revealed that alpha Pix accumulates in muthtt aggregates. Deletion analysis suggested that the dbl homology (DH) and pleckstrin homology (PH) domains of alpha Pix are required for its interaction with htt. Overexpression of alpha Pix enhanced muthtt aggregation by inducing SDS-soluble muthtt-muthtt interactions. Conversely, knocking down alpha Pix attenuated muhtt aggregation. These findings suggest that alpha Pix plays an important role in muthtt aggregation.

  10. Oxygen sensitivity of an Escherichia coli mutant.

    PubMed Central

    Adler, H; Mural, R; Suttle, B

    1992-01-01

    Genetic evidence indicates that Oxys-6, an oxygen-sensitive mutant of Escherichia coli AB1157, is defective in the region of the hemB locus. Oxys-6 is capable of growth under aerobic conditions only if cultures are initiated at low-inoculum levels. Aerobic liquid cultures are limited to a cell density of 10(7) cells per ml by the accumulation of a metabolically produced, low-molecular-weight, heat-stable material in complex organic media. Both Oxys-6 and AB1157 cells produce the material, but only aerobic cultures of the mutant are inhibited by it. The material is produced by both intact cells and cell extracts in complex media. This reaction also occurs when the amino acid L-lysine is substituted for complex media. Images PMID:1551829

  11. Acriflavine-Resistant Mutant of Streptococcus cremoris†

    PubMed Central

    Sinha, R.P.

    1977-01-01

    Selection for resistance to acriflavine in Streptococcus cremoris resulted in cross-resistance to the drugs neomycin, streptomycin, ethidium bromide, mitomycin C, and proflavine. Furthermore, the mutants showed resistance to lytic bacteriophages to which the parental strain was sensitive, and, unlike the parent, the mutants grew well at higher temperatures (40°C). Revertants selected independently either for temperature sensitivity or for acriflavine sensitivity lost resistance to all the drugs and dyes but retained the bacteriophage resistance phenotype. The acriflavine-resistant mutation resulted in an increase in resistance by the bacterial cells to sodium dodecyl sulfate, a potent solvent of lipopolysaccharide and lipoprotein. It is suggested that the acriflavine resistance mutation determines the synthesis of a membrane substance resistant to higher temperatures. PMID:907329

  12. Intact Interval Timing in Circadian CLOCK Mutants

    PubMed Central

    Cordes, Sara; Gallistel, C. R.

    2008-01-01

    While progress has been made in determining the molecular basis for the circadian clock, the mechanism by which mammalian brains time intervals measured in seconds to minutes remains a mystery. An obvious question is whether the interval timing mechanism shares molecular machinery with the circadian timing mechanism. In the current study, we trained circadian CLOCK +/− and −/− mutant male mice in a peak-interval procedure with 10 and 20-s criteria. The mutant mice were more active than their wild-type littermates, but there were no reliable deficits in the accuracy or precision of their timing as compared with wild-type littermates. This suggests that expression of the CLOCK protein is not necessary for normal interval timing. PMID:18602902

  13. Mutant KRAS promotes malignant pleural effusion formation.

    PubMed

    Agalioti, Theodora; Giannou, Anastasios D; Krontira, Anthi C; Kanellakis, Nikolaos I; Kati, Danai; Vreka, Malamati; Pepe, Mario; Spella, Magda; Lilis, Ioannis; Zazara, Dimitra E; Nikolouli, Eirini; Spiropoulou, Nikolitsa; Papadakis, Andreas; Papadia, Konstantina; Voulgaridis, Apostolos; Harokopos, Vaggelis; Stamou, Panagiota; Meiners, Silke; Eickelberg, Oliver; Snyder, Linda A; Antimisiaris, Sophia G; Kardamakis, Dimitrios; Psallidas, Ioannis; Marazioti, Antonia; Stathopoulos, Georgios T

    2017-05-16

    Malignant pleural effusion (MPE) is the lethal consequence of various human cancers metastatic to the pleural cavity. However, the mechanisms responsible for the development of MPE are still obscure. Here we show that mutant KRAS is important for MPE induction in mice. Pleural disseminated, mutant KRAS bearing tumour cells upregulate and systemically release chemokine ligand 2 (CCL2) into the bloodstream to mobilize myeloid cells from the host bone marrow to the pleural space via the spleen. These cells promote MPE formation, as indicated by splenectomy and splenocyte restoration experiments. In addition, KRAS mutations are frequently detected in human MPE and cell lines isolated thereof, but are often lost during automated analyses, as indicated by manual versus automated examination of Sanger sequencing traces. Finally, the novel KRAS inhibitor deltarasin and a monoclonal antibody directed against CCL2 are equally effective against an experimental mouse model of MPE, a result that holds promise for future efficient therapies against the human condition.

  14. EMMA--the European mouse mutant archive.

    PubMed

    Hagn, Michael; Marschall, Susan; Hrabè de Angelis, Martin

    2007-09-01

    The European Mouse Mutant Archive (EMMA) offers the worldwide scientific community a free archiving service for its mutant mouse lines and access to a wide range of disease models and other research tools. EMMA is currently comprised of seven partners who operate as the primary mouse repository in Europe. EMMA' s primary objectives are to establish and manage a unified repository for maintaining mouse mutations and to make them available to the scientific community. In addition to these core services, the consortium can generate germ-free (axenic) mice for its customers and also hosts courses in cryopreservation. EMMA is a founder member of the Federation of International Mouse Resources (FIMRe). The EMMA network is funded by the participating institutes, national research programmes and the European Commission Research Infrastructures Programme.

  15. Yersinia ruckeri lipopolysaccharide is necessary and sufficient for eliciting a protective immune response in rainbow trout (Oncorhynchus mykiss, Walbaum).

    PubMed

    Welch, Timothy J; LaPatra, Scott

    2016-02-01

    Enteric redmouth disease (ERM), caused by Yersinia ruckeri, has been controlled successfully using immersion-applied bacterin vaccines for several decades. While the host response to vaccination and the mechanism of protection of this vaccine have been elucidated, the bacterial components eliciting protection have remained unclear. Here we show that highly purified serotype O1 Y. ruckeri lipopolysaccharide (LPS) is sufficient to induce a protective response to experimental challenge in rainbow trout (Oncorhynchus mykiss). Dose response experiments demonstrated that Y. ruckeri LPS at doses of 1 ng/fish and above resulted in essentially complete protection and doses as low as 0.01 ng/fish (1.38 ng/kg) resulted in significant protection, thus demonstrating the extremely high potency of this immunogen. Analysis of the Y. ruckeri genome identified a cluster of putative O-antigen biosynthetic genes specific to serotype O1 strains. This cluster primarily consisted of genes encoding proteins predicted to function in the biosynthesis of legionamic acid, a nonulosonic acid known to be part of the O-polysaccharide repeat of O1 Y. ruckeri. Mutation of the nab2 gene, a nonulosonic acid biosynthesis gene (nab gene), resulted in production of severely truncated forms of LPS. Vaccination with bacterin vaccines derived from the nab2 mutant and its wild type parent strain demonstrated that LPS is a required component of the whole-cell bacterin vaccine and suggests that LPS is the only cellular component contributing to the protective response elicited by this vaccine. We speculate that the exceptionally high potency of Y. ruckeri LPS accounts for the unusual success of this vaccine when delivered by immersion. Published by Elsevier Ltd.

  16. Arabidopsis serotonin N-acetyltransferase knockout mutant plants exhibit decreased melatonin and salicylic acid levels resulting in susceptibility to an avirulent pathogen.

    PubMed

    Lee, Hyoung Yool; Byeon, Yeong; Tan, Dun-Xian; Reiter, Russel J; Back, Kyoungwhan

    2015-04-01

    Serotonin N-acetyltransferase (SNAT) is the penultimate enzyme in the melatonin biosynthesis pathway in plants. We examined the effects of SNAT gene inactivation in two Arabidopsis T-DNA insertion mutant lines. After inoculation with the avirulent pathogen Pseudomonas syringe pv. tomato DC3000 harboring the elicitor avrRpt2 (Pst-avrRpt2), melatonin levels in the snat knockout mutant lines were 50% less than in wild-type Arabidopsis Col-0 plants. The snat knockout mutant lines exhibited susceptibility to pathogen infection that coincided with decreased induction of defense genes including PR1, ICS1, and PDF1.2. Because melatonin acts upstream of salicylic acid (SA) synthesis, the reduced melatonin levels in the snat mutant lines led to decreased SA levels compared to wild-type, suggesting that the increased pathogen susceptibility of the snat mutant lines could be attributed to decreased SA levels and subsequent attenuation of defense gene induction. Exogenous melatonin treatment failed to induce defense gene expression in nahG Arabidopsis plants, but restored the induction of defense gene expression in the snat mutant lines. In addition, melatonin caused translocation of NPR1 (nonexpressor of PR1) protein from the cytoplasm into the nucleus indicating that melatonin-elicited pathogen resistance in response to avirulent pathogen attack is SA-dependent in Arabidopsis.

  17. Comparison of physiological responses to affect eliciting pictures and music.

    PubMed

    Kim, Jongwan; Wedell, Douglas H

    2016-03-01

    Recent investigations of the neural correlates of affect elicited from different modalities have found both modality-general and modality-specific representations (Chikazoe et al., 2014). The implications for how physiological responses to affect differ across stimulus modalities have not been fully investigated. This study examined similarities and differences between physiological signatures of affect derived from two different modes of presentation: visual pictures and auditory music sampled from an affective space defined by valence and arousal. Electromyography recordings for the zygomaticus major (EMGZ) and corrugator supercilii (EMGC) were measured along with heart rate and skin conductance level (SCL). Multidimensional scaling was used to visualize relationships from physiological and behavioral responses, and the observed relationships were statistically evaluated using multivariate and univariate analyses. Results for physiological measures demonstrated that valence was represented in the same general way across modalities, primarily reflected in EMGC responses. Arousal, however, was represented in a modality-specific manner, with SCL and EMGZ sensitive to music-based arousal but not picture-based arousal. Stimulus modality itself was predicted from EMGC. Thus, physiological responses to valence were similar across modalities but physiological responses to arousal differed across modalities. These results support the utility of testing for affective markers across modalities within the same experimental setting to reveal how physiological responses are linked to either affect, stimulus modality or both.

  18. Affective Monitoring: A Generic Mechanism for Affect Elicitation

    PubMed Central

    Phaf, R. Hans; Rotteveel, Mark

    2012-01-01

    In this paper we sketch a new framework for affect elicitation, which is based on previous evolutionary and connectionist modeling and experimental work from our group. Affective monitoring is considered a local match–mismatch process within a module of the neural network. Negative affect is raised instantly by mismatches, incongruency, disfluency, novelty, incoherence, and dissonance, whereas positive affect follows from matches, congruency, fluency, familiarity, coherence, and resonance, at least when an initial mismatch can be solved quickly. Affective monitoring is considered an evolutionary-early conflict and change detection process operating at the same level as, for instance, attentional selection. It runs in parallel and imparts affective flavor to emotional behavior systems, which involve evolutionary-prepared stimuli and action tendencies related to for instance defensive, exploratory, attachment, or appetitive behavior. Positive affect is represented in the networks by high-frequency oscillations, presumably in the gamma band. Negative affect corresponds to more incoherent lower-frequency oscillations, presumably in the theta band. For affect to become conscious, large-scale synchronization of the oscillations over the network and the construction of emotional experiences are required. These constructions involve perceptions of bodily states and action tendencies, but also appraisals as well as efforts to regulate the emotion. Importantly, affective monitoring accompanies every kind of information processing, but conscious emotions, which result from the later integration of affect in a cognitive context, are much rarer events. PMID:22403557

  19. Naturalistic Enactment to Elicit and Recognize Caregiver State Anxiety.

    PubMed

    Miranda, Darien; Favela, Jesus; Ibarra, Catalina; Cruz, Netzahualcoyotl

    2016-09-01

    Caring for people with dementia imposes significant stress on family members and caregivers. Often, these informal caregivers have no coping strategy to deal with these behaviors. Anxiety and stress episodes are often triggered by problematic behaviors exhibited by the person who suffers from dementia. Detecting these behaviors could help them in dealing with them and reduce caregiver burden. However, work on anxiety detection using physiological signals has mostly been done under controlled conditions. In this paper we describe an experiment aimed at inducing anxiety among caregivers of people with dementia under naturalistic conditions. We report an experiment, using the naturalistic enactment technique, in which 10 subjects were asked to care for an older adult who acts as if she experiences dementia. We record physiological signals from the participants (GSR, HR, EEG) during the sessions that lasted for approximately 30 min. We explain how we obtained ground truth from self-report and observation data. We conducted two different tests using the Support Vector Machine technique. We obtained an average precision of 77.8 % and 38.1 % recall when classifying two different possible states: "Anxious" and "Not anxious". Analysis of the data provides evidence that the experiment elicits state anxiety and that it can be detected using wearable sensors. Furthermore, if episodes of problematic behaviors can also be detected, the recognition of anxiety in the caregiver can be improved, leading to the enactment of appropriate interventions to help caregivers cope with anxiety episodes.

  20. Reading the lesson: eliciting requirements for a mammography training application

    NASA Astrophysics Data System (ADS)

    Hartswood, M.; Blot, L.; Taylor, P.; Anderson, S.; Procter, R.; Wilkinson, L.; Smart, L.

    2009-02-01

    Demonstrations of a prototype training tool were used to elicit requirements for an intelligent training system for screening mammography. The prototype allowed senior radiologists (mentors) to select cases from a distributed database of images to meet the specific training requirements of junior colleagues (trainees) and then provided automated feedback in response to trainees' attempts at interpretation. The tool was demonstrated to radiologists and radiographers working in the breast screening service at four evaluation sessions. Participants highlighted ease of selecting cases that can deliver specific learning objectives as important for delivering effective training. To usefully structure a large data set of training images we undertook a classification exercise of mentor authored free text 'learning points' attached to training case obtained from two screening centres (n=333, n=129 respectively). We were able to adduce a hierarchy of abstract categories representing classes of lesson that groups of cases were intended to convey (e.g. Temporal change, Misleading juxtapositions, Position of lesion, Typical/Atypical presentation, and so on). In this paper we present the method used to devise this classification, the classification scheme itself, initial user-feedback, and our plans to incorporated it into a software tool to aid case selection.

  1. PEGylated graphene oxide elicits strong immunological responses despite surface passivation

    NASA Astrophysics Data System (ADS)

    Luo, Nana; Weber, Jeffrey K.; Wang, Shuang; Luan, Binquan; Yue, Hua; Xi, Xiaobo; Du, Jing; Yang, Zaixing; Wei, Wei; Zhou, Ruhong; Ma, Guanghui

    2017-02-01

    Engineered nanomaterials promise to transform medicine at the bio-nano interface. However, it is important to elucidate how synthetic nanomaterials interact with critical biological systems before such products can be safely utilized in humans. Past evidence suggests that polyethylene glycol-functionalized (PEGylated) nanomaterials are largely biocompatible and elicit less dramatic immune responses than their pristine counterparts. We here report results that contradict these findings. We find that PEGylated graphene oxide nanosheets (nGO-PEGs) stimulate potent cytokine responses in peritoneal macrophages, despite not being internalized. Atomistic molecular dynamics simulations support a mechanism by which nGO-PEGs preferentially adsorb onto and/or partially insert into cell membranes, thereby amplifying interactions with stimulatory surface receptors. Further experiments demonstrate that nGO-PEG indeed provokes cytokine secretion by enhancing integrin β8-related signalling pathways. The present results inform that surface passivation does not always prevent immunological reactions to 2D nanomaterials but also suggest applications for PEGylated nanomaterials wherein immune stimulation is desired.

  2. Social conflicts elicit an N400-like component.

    PubMed

    Huang, Yi; Kendrick, Keith M; Yu, Rongjun

    2014-12-01

    When people have different opinions, they often adjust their own attitude to match that of others, known as social conformity. How social conflicts trigger subsequent conformity remains unclear. One possibility is that a conflict with the group opinion is perceived as a violation of social information, analogous to using wrong grammar, and activates conflict monitoring and adjustment mechanisms. Using event related potential (ERP) recording combined with a face attractiveness judgment task, we investigated the neural encoding of social conflicts. We found that social conflicts elicit an N400-like negative deflection, being more negative for conflict with group opinions than no-conflict condition. The social conflict related signals also have a bi-directional profile similar to reward prediction error signals: it was more negative for under-estimation (i.e. one׳s own ratings were smaller than group ratings) than over-estimation, and the larger the differences between ratings, the larger the N400 amplitude. The N400 effects were significantly diminished in the non-social condition. We conclude that social conflicts are encoded in a bidirectional fashion in the N400-like component, similar to the pattern of reward-based prediction error signals. Our findings also suggest that the N400, a well-established ERP component encoding semantic violation, might be involved in social conflict processing and social learning. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Assessing Mental Models of Emergencies Through Two Knowledge Elicitation Tasks.

    PubMed

    Whitmer, Daphne E; Sims, Valerie K; Torres, Michael E

    2017-05-01

    The goals of this study were to assess the risk identification aspect of mental models using standard elicitation methods and how university campus alerts were related to these mental models. People fail to follow protective action recommendations in emergency warnings. Past research has yet to examine cognitive processes that influence emergency decision-making. Study 1 examined 2 years of emergency alerts distributed by a large southeastern university. In Study 2, participants listed emergencies in a thought-listing task. Study 3 measured participants' time to decide if a situation was an emergency. The university distributed the most alerts about an armed person, theft, and fire. In Study 2, participants most frequently listed fire, car accident, heart attack, and theft. In Study 3, participants quickly decided a bomb, murder, fire, tornado, and rape were emergencies. They most slowly decided that a suspicious package and identify theft were emergencies. Recent interaction with warnings was only somewhat related to participants' mental models of emergencies. Risk identification precedes decision-making and applying protective actions. Examining these characteristics of people's mental representations of emergencies is fundamental to further understand why some emergency warnings go ignored. Someone must believe a situation is serious to categorize it as an emergency before taking the protective action recommendations in an emergency warning. Present-day research must continue to examine the problem of people ignoring warning communication, as there are important cognitive factors that have not yet been explored until the present research.

  4. Dreamed movement elicits activation in the sensorimotor cortex.

    PubMed

    Dresler, Martin; Koch, Stefan P; Wehrle, Renate; Spoormaker, Victor I; Holsboer, Florian; Steiger, Axel; Sämann, Philipp G; Obrig, Hellmuth; Czisch, Michael

    2011-11-08

    Since the discovery of the close association between rapid eye movement (REM) sleep and dreaming, much effort has been devoted to link physiological signatures of REM sleep to the contents of associated dreams [1-4]. Due to the impossibility of experimentally controlling spontaneous dream activity, however, a direct demonstration of dream contents by neuroimaging methods is lacking. By combining brain imaging with polysomnography and exploiting the state of "lucid dreaming," we show here that a predefined motor task performed during dreaming elicits neuronal activation in the sensorimotor cortex. In lucid dreams, the subject is aware of the dreaming state and capable of performing predefined actions while all standard polysomnographic criteria of REM sleep are fulfilled [5, 6]. Using eye signals as temporal markers, neural activity measured by functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS) was related to dreamed hand movements during lucid REM sleep. Though preliminary, we provide first evidence that specific contents of REM-associated dreaming can be visualized by neuroimaging.

  5. Rod-shaped nanocrystals elicit neuronal activity in vivo.

    PubMed

    Malvindi, Maria Ada; Carbone, Luigi; Quarta, Alessandra; Tino, Angela; Manna, Liberato; Pellegrino, Teresa; Tortiglione, Claudia

    2008-10-01

    The development of novel nanomaterials has raised great interest in efforts to evaluate their effect on biological systems, ranging from single cells to whole animals. In particular, there exists an open question regarding whether nanoparticles per se can elicit biological responses, which could interfere with the phenomena they are intended to measure. Here it is reported that challenging the small cnidaria Hydra vulgaris in vivo with rod-shaped semiconductor nanoparticles, also known as quantum rods (QRs), results in an unexpected tentacle-writhing behavior, which is Ca(2+) dependent and relies on the presence of tentacle neurons. Due to the absence of surface functionalization of the QRs with specific ligands, and considering that spherical nanoparticles with same composition as the QRs fail to induce any in vivo behavior on the same experimental model, it is suggested that unique shape-tunable electrical properties of the QRs may account for the neuronal stimulation. This model system may represent a widely applicable tool for screening neuronal response to nanoparticles in vivo.

  6. PEGylated graphene oxide elicits strong immunological responses despite surface passivation

    PubMed Central

    Luo, Nana; Weber, Jeffrey K.; Wang, Shuang; Luan, Binquan; Yue, Hua; Xi, Xiaobo; Du, Jing; Yang, Zaixing; Wei, Wei; Zhou, Ruhong; Ma, Guanghui

    2017-01-01

    Engineered nanomaterials promise to transform medicine at the bio–nano interface. However, it is important to elucidate how synthetic nanomaterials interact with critical biological systems before such products can be safely utilized in humans. Past evidence suggests that polyethylene glycol-functionalized (PEGylated) nanomaterials are largely biocompatible and elicit less dramatic immune responses than their pristine counterparts. We here report results that contradict these findings. We find that PEGylated graphene oxide nanosheets (nGO-PEGs) stimulate potent cytokine responses in peritoneal macrophages, despite not being internalized. Atomistic molecular dynamics simulations support a mechanism by which nGO-PEGs preferentially adsorb onto and/or partially insert into cell membranes, thereby amplifying interactions with stimulatory surface receptors. Further experiments demonstrate that nGO-PEG indeed provokes cytokine secretion by enhancing integrin β8-related signalling pathways. The present results inform that surface passivation does not always prevent immunological reactions to 2D nanomaterials but also suggest applications for PEGylated nanomaterials wherein immune stimulation is desired. PMID:28233871

  7. Small-molecule elicitation of microbial secondary metabolites.

    PubMed

    Pettit, Robin K

    2011-07-01

    Microbial natural products continue to be an unparalleled resource for pharmaceutical lead discovery, but the rediscovery rate is high. Bacterial and fungal sequencing studies indicate that the biosynthetic potential of many strains is much greater than that observed by fermentation. Prodding the expression of such silent (cryptic) pathways will allow us to maximize the chemical diversity available from microorganisms. Cryptic metabolic pathways can be accessed in the laboratory using molecular or cultivation-based approaches. A targeted approach related to cultivation-based methods is the application of small-molecule elicitors to specifically affect transcription of secondary metabolite gene clusters. With the isolation of the novel secondary metabolites lunalides A and B, oxylipins, cladochromes F and G, nygerone A, chaetoglobosin-542, -540 and -510, sphaerolone, dihydrosphaerolone, mutolide and pestalone, and the enhanced production of known secondary metabolites like penicillin and bacitracin, chemical elicitation is proving to be an effective way to augment natural product libraries. © 2010 The Authors. Journal compilation © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  8. Invisible visual stimuli elicit increases in alpha-band power.

    PubMed

    Bareither, Isabelle; Chaumon, Maximilien; Bernasconi, Fosco; Villringer, Arno; Busch, Niko A

    2014-09-01

    The cerebral cortex responds to stimuli of a wide range of intensities. Previous studies have demonstrated that undetectably weak somatosensory stimuli cause a functional deactivation or inhibition in somatosensory cortex. In the present study, we tested whether invisible visual stimuli lead to similar responses, indicated by an increase in EEG alpha-band power-an index of cortical excitability. We presented subliminal and supraliminal visual stimuli after estimating each participant's detection threshold. Stimuli consisted of peripherally presented small circular patches that differed in their contrast to a background consisting of a random white noise pattern. We demonstrate that subliminal and supraliminal stimuli each elicit specific neuronal response patterns. Supraliminal stimuli evoked an early, strongly phase-locked lower-frequency response representing the evoked potential and induced a decrease in alpha-band power from 400 ms on. By contrast, subliminal visual stimuli induced an increase of non-phase-locked power around 300 ms that was maximal within the alpha-band. This response might be due to an inhibitory mechanism, which reduces spurious visual activation that is unlikely to result from external stimuli. Copyright © 2014 the American Physiological Society.

  9. Micafungin Elicits an Immunomodulatory Effect in Galleria mellonella and Mice.

    PubMed

    Fuchs, Beth Burgwyn; Li, Yan; Li, Dedong; Johnston, Tatiana; Hendricks, Gabriel; Li, Gang; Rajamuthiah, Rajmohan; Mylonakis, Eleftherios

    2016-02-01

    The echinocandin family of drugs is well characterized for antifungal function that inhibits β-D-glucan synthesis. The aim of this work was to study whether micafungin, a member of the echinocandin family, elicits additional activities that prime the host's immune response. We found that in a Galleria mellonella model, prophylactic treatment with micafungin extended the life of Staphylococcus aureus-infected larvae (a pathogen to which the drug demonstrates no direct antimicrobial activity) compared to insects that did not receive micafungin (P < 0.05). The inhibition of pathogens in the G. mellonella infection model was characterized by a 2.43-fold increase in hemocyte density, compared to larvae inoculated with PBS. In a murine model where animals were provided micafungin prophylaxis 3 days prior to macrophage collection, macrophages were found associated with an average 0.9 more fungal cells per macrophage as compared to saline-treated animals. Interestingly, micafungin-stimulated macrophages killed 11.6 ± 6.2 % of fungal cells compared to 3.8 ± 2.4 % of macrophages from saline-treated animals. The prophylactic provision of micafungin prior to Candida albicans infection was characterized by an increase in the proinflammatory cytokines CXCL13 and SPP1 by 11- and 6.9-fold, respectively. In conclusion, micafungin demonstrated the ability to stimulate phagocytic cells and promote an immune response that can inhibit microbial infections.

  10. Genuine eye contact elicits self-referential processing.

    PubMed

    Hietanen, Jonne O; Hietanen, Jari K

    2017-03-16

    The effect of eye contact on self-awareness was investigated with implicit measures based on the use of first-person singular pronouns in sentences. The measures were proposed to tap into self-referential processing, that is, information processing associated with self-awareness. In addition, participants filled in a questionnaire measuring explicit self-awareness. In Experiment 1, the stimulus was a video clip showing another person and, in Experiment 2, the stimulus was a live person. In both experiments, participants were divided into two groups and presented with the stimulus person either making eye contact or gazing downward, depending on the group assignment. During the task, the gaze stimulus was presented before each trial of the pronoun-selection task. Eye contact was found to increase the use of first-person pronouns, but only when participants were facing a real person, not when they were looking at a video of a person. No difference in self-reported self-awareness was found between the two gaze direction groups in either experiment. The results indicate that eye contact elicits self-referential processing, but the effect may be stronger, or possibly limited to, live interaction.

  11. Multiple Membrane Interactions and Versatile Vesicle Deformations Elicited by Melittin

    PubMed Central

    Takahashi, Tomoyoshi; Nomura, Fumimasa; Yokoyama, Yasunori; Tanaka-Takiguchi, Yohko; Homma, Michio; Takiguchi, Kingo

    2013-01-01

    Melittin induces various reactions in membranes and has been widely studied as a model for membrane-interacting peptide; however, the mechanism whereby melittin elicits its effects remains unclear. Here, we observed melittin-induced changes in individual giant liposomes using direct real-time imaging by dark-field optical microscopy, and the mechanisms involved were correlated with results obtained using circular dichroism, cosedimentation, fluorescence quenching of tryptophan residues, and electron microscopy. Depending on the concentration of negatively charged phospholipids in the membrane and the molecular ratio between lipid and melittin, melittin induced the “increasing membrane area”, “phased shrinkage”, or “solubilization” of liposomes. In phased shrinkage, liposomes formed small particles on their surface and rapidly decreased in size. Under conditions in which the increasing membrane area, phased shrinkage, or solubilization were mainly observed, the secondary structure of melittin was primarily estimated as an α-helix, β-like, or disordered structure, respectively. When the increasing membrane area or phased shrinkage occurred, almost all melittin was bound to the membranes and reached more hydrophobic regions of the membranes than when solubilization occurred. These results indicate that the various effects of melittin result from its ability to adopt various structures and membrane-binding states depending on the conditions. PMID:23594437

  12. Point of view filming and the elicitation interview.

    PubMed

    Skinner, Jonathan; Gormley, Gerard J

    2016-08-01

    Face-to-face interviews are a fundamental research tool in qualitative research. Whilst this form of data collection can provide many valuable insights, it can often fall short of providing a complete picture of a research subject's experiences. Point of view (PoV) interviewing is an elicitation technique used in the social sciences as a means of enriching data obtained from research interviews. Recording research subjects' first person perspectives, for example by wearing digital video glasses, can afford deeper insights into their experiences. PoV interviewing can promote making visible the unverbalizable and does not rely as much on memory as the traditional interview. The use of such relatively inexpensive technology is gaining interest in health profession educational research and pedagogy, such as dynamic simulation-based learning and research activities. In this interview, Dr Gerry Gormley (a medical education researcher) talks to Dr Jonathan Skinner (an anthropologist with an interest in PoV interviewing), exploring some of the many crossover implications with PoV interviewing for medical education research and practice.

  13. Arabidopsis MET1 cytosine methyltransferase mutants.

    PubMed Central

    Kankel, Mark W; Ramsey, Douglas E; Stokes, Trevor L; Flowers, Susan K; Haag, Jeremy R; Jeddeloh, Jeffrey A; Riddle, Nicole C; Verbsky, Michelle L; Richards, Eric J

    2003-01-01

    We describe the isolation and characterization of two missense mutations in the cytosine-DNA-methyltransferase gene, MET1, from the flowering plant Arabidopsis thaliana. Both missense mutations, which affect the catalytic domain of the protein, led to a global reduction of cytosine methylation throughout the genome. Surprisingly, the met1-2 allele, with the weaker DNA hypomethylation phenotype, alters a well-conserved residue in methyltransferase signature motif I. The stronger met1-1 allele caused late flowering and a heterochronic delay in the juvenile-to-adult rosette leaf transition. The distribution of late-flowering phenotypes in a mapping population segregating met1-1 indicates that the flowering-time phenotype is caused by the accumulation of inherited defects at loci unlinked to the met1 mutation. The delay in flowering time is due in part to the formation and inheritance of hypomethylated fwa epialleles, but inherited defects at other loci are likely to contribute as well. Centromeric repeat arrays hypomethylated in met1-1 mutants are partially remethylated when introduced into a wild-type background, in contrast to genomic sequences hypomethylated in ddm1 mutants. ddm1 met1 double mutants were constructed to further our understanding of the mechanism of DDM1 action and the interaction between two major genetic loci affecting global cytosine methylation levels in Arabidopsis. PMID:12663548

  14. Isolation of Pasteurella haemolytica leukotoxin mutants.

    PubMed Central

    Chidambaram, M; Sharma, B; Petras, S F; Reese, C P; Froshauer, S; Weinstock, G M

    1995-01-01

    Two mutants of Pasteurella haemolytica A1 that do not produce leukotoxin were isolated. Following mutagenesis, colonies were screened with antiserum by a filter assay for absence of the secreted leukotoxin. The two mutants both appeared to produce normal amounts of other antigens, as judged by reactivity with polyclonal serum from an animal with pasteurellosis, and were not altered in beta-hemolytic activity as seen on blood agar plates. There was no evidence of either cell-associated or secreted leukotoxin protein when Western blots (immunoblots) were carried out with the polyclonal serum or with a monoclonal antibody directed against the leukotoxin. Southern blots revealed that both mutants show the wild-type restriction pattern at the leukotoxin locus, although the strain with the lktA2 mutation showed differences in other regions of the chromosome on analysis by pulsed-field gel electrophoresis. The strain with the lktA2 mutation grew more slowly than did the wild-type strain, while the strain with the lktA1 mutation was indistinguishable from the wild-type strain in its growth properties. The strain with the lktA1 mutation should be valuable in determining the role of the leukotoxin in virulence as well as in identifying other virulence factors of P. haemolytica. PMID:7868223

  15. Mutant chaperonin proteins: new tools for nanotechnology

    NASA Astrophysics Data System (ADS)

    Li, Y.; Paavola, C. D.; Kagawa, H.; Chan, S. L.; Trent, J. D.

    2007-11-01

    Much effort has gone into finding peptides that bind potentially useful nanoparticles, but relatively little effort has focused on the scaffolds that organize these peptides into useful nanostructures. Chaperonins are protein complexes with 14-18 protein subunits that self-assemble into double-ring complexes and function as scaffolds for peptides or amino acids that bind metallic and semiconductor quantum dots. The utility of chaperonins as scaffolds depends on their structure and their ability to self-assemble into double-rings and higher-order structures, such as filaments and two-dimensional arrays. To better understand the structure of chaperonins, we constructed a model of a group II chaperonin and, based on this model, genetically constructed five mutant subunits with significant deletions. We expressed these mutants as recombinant proteins and observed by native polyacrylamide gel electrophoresis (PAGE) and transmission electron microscopy (TEM) that they all self-assembled into double rings. Our model predicted and TEM confirmed that these deletions did not significantly change the 17 nm diameter of the wild-type double rings, but decreased their height and opened their central cavities. Four of the five mutants formed higher-order structures: chains of rings, bundles of chains or filaments, and two-dimensional arrays, which we suggest can be useful nanostructures.

  16. Sleep restores behavioral plasticity to Drosophila mutants

    PubMed Central

    Dissel, Stephane; Angadi, Veena; Kirszenblat, Leonie; Suzuki, Yasuko; Donlea, Jeff; Klose, Markus; Koch, Zachary; English, Denis; Winsky-Sommerer, Raphaelle; van Swinderen, Bruno; Shaw, Paul J.

    2015-01-01

    SUMMARY Given the role that sleep plays in modulating plasticity, we hypothesized that increasing sleep would restore memory to canonical memory mutants without specifically rescuing the causal molecular-lesion. Sleep was increased using three independent strategies: activating the dorsal Fan Shaped Body (FB), increasing the expression of Fatty acid binding protein (dFabp) or by administering the GABA-A agonist 4,5,6,7-tetrahydroisoxazolo-[5,4-c]pyridine-3-ol (THIP). Short-term memory (STM) or Long-term memory (LTM) was evaluated in rutabaga (rut) and dunce (dnc) mutants using Aversive Phototaxic Suppression (APS) and courtship conditioning. Each of the three independent strategies increased sleep and restored memory to rut and dnc mutants. Importantly, inducing sleep also reverses memory defects in a Drosophila model of Alzheimer’s disease. Together these data demonstrate that sleep plays a more fundamental role in modulating behavioral plasticity than previously appreciated and suggests that increasing sleep may benefit patients with certain neurological disorders. PMID:25913403

  17. Mutant Sodium Channel for Tumor Therapy

    PubMed Central

    Tannous, Bakhos A; Christensen, Adam P; Pike, Lisa; Wurdinger, Thomas; Perry, Katherine F; Saydam, Okay; Jacobs, Andreas H; García-Añoveros, Jaime; Weissleder, Ralph; Sena-Esteves, Miguel; Corey, David P; Breakefield, Xandra O

    2009-01-01

    Viral vectors have been used to deliver a wide range of therapeutic genes to tumors. In this study, a novel tumor therapy was achieved by the delivery of a mammalian brain sodium channel, ASIC2a, carrying a mutation that renders it constitutively open. This channel was delivered to tumor cells using a herpes simplex virus-1/Epstein–Barr virus (HSV/EBV) hybrid amplicon vector in which gene expression was controlled by a tetracycline regulatory system (tet-on) with silencer elements. Upon infection and doxycycline induction of mutant channel expression in tumor cells, the open channel led to amiloride-sensitive sodium influx as assessed by patch clamp recording and sodium imaging in culture. Within hours, tumor cells swelled and died. In addition to cells expressing the mutant channel, adjacent, noninfected cells connected by gap junctions also died. Intratumoral injection of HSV/EBV amplicon vector encoding the mutant sodium channel and systemic administration of doxycycline led to regression of subcutaneous tumors in nude mice as assessed by in vivo bioluminescence imaging. The advantage of this direct mode of tumor therapy is that all types of tumor cells become susceptible and death is rapid with no time for the tumor cells to become resistant. PMID:19259066

  18. Virus growth and antibody responses following respiratory tract infection of ferrets and mice with WT and P/V mutants of the paramyxovirus Simian Virus 5

    PubMed Central

    Capraro, Gerald A.; Johnson, John B.; Kock, Nancy D.; Parks, Griffith D.

    2008-01-01

    P/V gene substitutions convert the non-cytopathic paramyxovirus Simian Virus 5 (SV5), which is a poor inducer of host cell responses in human tissue culture cells, into a mutant (P/V-CPI–) that induces high levels of apoptosis, interferon (IFN)-beta, and proinflammatory cytokines. However, the effect of SV5-P/V gene mutations on virus growth and adaptive immune responses in animals has not been determined. Here, we used two distinct animal model systems to test the hypothesis that SV5-P/V mutants which are more potent activators of innate responses in tissue culture will also elicit higher antiviral antibody responses. In mouse cells, in vitro studies identified a panel of SV5-P/V mutants that ranged in their ability to limit IFN responses. Intranasal infection of mice with these WT and P/V mutant viruses elicited equivalent anti-SV5 IgG responses at all doses tested, and viral titers recovered from the respiratory tract were indistinguishable. In primary cultures of ferret lung fibroblasts, WT rSV5 and P/V-CPI– viruses had phenotypes similar to those established in human cell lines, including differential induction of IFN secretion, IFN signaling and apoptosis. Intranasal infection of ferrets with a low dose of WT rSV5 elicited ~500 fold higher anti-SV5 serum IgG responses compared to the P/V-CPI– mutant, and this correlated with overall higher viral titers for the WT virus in tracheal tissues. There was a dose-dependent increase in antibody response to infection of ferrets with P/V-CPI–, but not with WT rSV5. Together our data indicate that WT rSV5 and P/V mutants can elicit distinct innate and adaptive immunity phenotypes in the ferret animal model system, but not in the mouse system. We present a model for the effect of P/V gene substitutions on SV5 growth and immune responses in vivo. PMID:18456301

  19. Mutant p53: One, No One, and One Hundred Thousand.

    PubMed

    Walerych, Dawid; Lisek, Kamil; Del Sal, Giannino

    2015-01-01

    Encoded by the mutated variants of the TP53 tumor suppressor gene, mutant p53 proteins are getting an increased experimental support as active oncoproteins promoting tumor growth and metastasis. p53 missense mutant proteins are losing their wild-type tumor suppressor activity and acquire oncogenic potential, possessing diverse transforming abilities in cell and mouse models. Whether various mutant p53s differ in their oncogenic potential has been a matter of debate. Recent discoveries are starting to uncover the existence of mutant p53 downstream programs that are common to different mutant p53 variants. In this review, we discuss a number of studies on mutant p53, underlining the advantages and disadvantages of alternative experimental approaches that have been used to describe the numerous mutant p53 gain-of-function activities. Therapeutic possibilities are also discussed, taking into account targeting either individual or multiple mutant p53 proteins in human cancer.

  20. Isolation of a novel mutant from Bacillus subtilis natto.

    PubMed

    Yoshida, Kazuo

    2006-01-01

    For the construction of strains with full probiotics function in intestines, deoxycholate resistant mutants were isolated from Bacillus subtilis natto. The partial characterization of the mutants was carried out and described.

  1. A Mutant of Mycobacterium smegmatis Defective in Dipeptide Transport

    PubMed Central

    Bhatt, Achal; Green, Renee; Coles, Roswell; Condon, Michael; Connell, Nancy D.

    1998-01-01

    A mutant of Mycobacterium smegmatis unable to use the dipeptide carnosine (β-alanyl-l-histidine) as a sole carbon or nitrogen source was isolated. Carnosinase activity and the ability to grow on β-Ala and/or l-His were similar in the mutant and the wild type. However, the mutant showed significant impairment in the uptake of carnosine. This study is the first description of a peptide utilization mutant of a mycobacterium. PMID:9852030

  2. Isolation and Preliminary Characterization of Developmental Mutants from Microsporum gypseum

    PubMed Central

    Leighton, T. J.; Stock, J. J.

    1970-01-01

    Developmental mutants affected in either sporulation or spore germination have been isolated from Microsporum gypseum with the aid of nitrosoguanidine or as spontaneously occurring mutants. The time course levels of several proteins temporally associated with conidial development have been assayed in the wild-type and mutant strains. The spore germination characteristics of two of the mutants are described. The relationship of alkaline protease accumulation to tyrosinase accumulation and spore germination is discussed. PMID:4992372

  3. The Cryptococcus neoformans Gene DHA1 Encodes an Antigen That Elicits a Delayed-Type Hypersensitivity Reaction in Immune Mice

    PubMed Central

    Mandel, M. Alejandra; Grace, Greg G.; Orsborn, Kris I.; Schafer, Fredda; Murphy, Juneann W.; Orbach, Marc J.; Galgiani, John N.

    2000-01-01

    When mice are vaccinated with a culture filtrate from Cryptococcus neoformans (CneF), they mount a protective cell-mediated immune response as detected by dermal delayed-type hypersensitivity (DTH) to CneF. We have identified a gene (DHA1) whose product accounts at least in part for the DTH reactivity. Using an acapsular mutant (Cap-67) of C. neoformans strain B3501, we prepared a culture filtrate (CneF-Cap67) similar to that used for preparing the commonly used skin test antigen made with C. neoformans 184A (CneF-184A). CneF-Cap67 elicited DTH in mice immunized with CneF-184A. Deglycosylation of CneF-Cap67 did not diminish its DTH activity. Furthermore, size separation by either chromatography or differential centrifugation identified the major DTH activity of CneF-Cap67 to be present in fractions that contained proteins of approximately 19 to 20 kDa. Using N-terminal and internal amino acid sequences derived from the 20-kDa band, oligonucleotide primers were designed, two of which produced a 776-bp amplimer by reverse transcription-PCR (RT-PCR) using RNA from Cap-67 to prepare cDNA for the template. The amplimer was used as a probe to isolate clones containing the full-length DHA1 gene from a phage genomic library prepared from strain B3501. The full-length cDNA was obtained by 5′ rapid amplification of cDNA ends and RT-PCR. Analysis of DHA1 revealed a similarity between the deduced open reading frame and that of a developmentally regulated gene from Lentinus edodes (shiitake mushroom) associated with fruiting-body formation. Also, the gene product contained several amino acid sequences identical to those determined biochemically from the purified 20-kDa peptide encoded by DHA1. Recombinant DHA1 protein expressed in Escherichia coli was shown to elicit DTH reactions similar to those elicited by CneF-Cap67 in mice immunized against C. neoformans. Thus, DHA1 is the first gene to be cloned from C. neoformans whose product has been shown to possess immunologic

  4. Deprivation of pantothenic acid elicits a movement disorder and azoospermia in a mouse model of pantothenate kinase-associated neurodegeneration.

    PubMed

    Kuo, Y M; Hayflick, S J; Gitschier, J

    2007-06-01

    We asked whether a movement disorder could be elicited by deprivation of pantothenic acid (PA; vitamin B5), the substrate for the enzyme pantothenate kinase 2 (PANK2), which is deficient in the inherited neurological disorder PKAN (pantothenate kinase-associated neurodegeneration formerly called Hallervorden-Spatz syndrome). This study was undertaken because mice made null for Pank2 failed to show the neurological manifestations of the human disease. Wild-type and Pank2 mutant mice were fed pantothenic acid-deficient diets and were monitored for general health, fertility and movement compared with animals on control diets over time. Mice of both genotypes on PA-deficient diets exhibited poor grooming, greying of fur and decreased body weight. With PA deprivation, wild-type mice manifested azoospermia (a phenotype also seen in Pank2 mice) as well as a movement disorder with a low-lying pelvis and slow steps. Rear limbs appeared to drag and occasionally extended into unnatural postures for 16-17 s duration, possibly indicative of dystonia. Movement disruption probably also occurs in PA-deprived Pank2 mutant mice, but they died precipitously before undergoing detailed analysis. Remarkably, restoration of dietary PA led to recovery of general health and grooming, weight gain, reversal of the movement disorder, and reappearance of mature sperm within 4 weeks. This study confirms the primacy of PA metabolism in the mechanism of disease in PKAN. PA deprivation provides a useful phenocopy for PKAN and allows us to test pharmacological and other interventional strategies in the treatment of this devastating disease.

  5. Deprivation of pantothenic acid elicits a movement disorder and azoospermia in a mouse model of pantothenate kinase-associated neurodegeneration

    PubMed Central

    Kuo, Y. M.; Hayflick, S. J.; Gitschier, J.

    2007-01-01

    Summary We asked whether a movement disorder could be elicited by deprivation of pantothenic acid (PA; vitamin B5), the substrate for the enzyme pantothenate kinase 2 (PANK2), which is deficient in the inherited neurological disorder PKAN (pantothenate kinase-associated neurodegeneration formerly called Hallervorden–Spatz syndrome). This study was undertaken because mice made null for Pank2 failed to show the neurological manifestations of the human disease. Wild-type and Pank2 mutant mice were fed pantothenic acid-deficient diets and were monitored for general health, fertility and movement compared with animals on control diets over time. Mice of both genotypes on PA-deficient diets exhibited poor grooming, greying of fur and decreased body weight. With PA deprivation, wild-type mice manifested azoospermia (a phenotype also seen in Pank2 mice) as well as a movement disorder with a low-lying pelvis and slow steps. Rear limbs appeared to drag and occasionally extended into unnatural postures for 16–17 s duration, possibly indicative of dystonia. Movement disruption probably also occurs in PA-deprived Pank2 mutant mice, but they died precipitously before undergoing detailed analysis. Remarkably, restoration of dietary PA led to recovery of general health and grooming, weight gain, reversal of the movement disorder, and reappearance of mature sperm within 4 weeks. This study confirms the primacy of PA metabolism in the mechanism of disease in PKAN. PA deprivation provides a useful phenocopy for PKAN and allows us to test pharmacological and other interventional strategies in the treatment of this devastating disease. PMID:17429753

  6. Targeting Oncogenic Mutant p53 for Cancer Therapy.

    PubMed

    Parrales, Alejandro; Iwakuma, Tomoo

    2015-01-01

    Among genetic alterations in human cancers, mutations in the tumor suppressor p53 gene are the most common, occurring in over 50% of human cancers. The majority of p53 mutations are missense mutations and result in the accumulation of dysfunctional p53 protein in tumors. These mutants frequently have oncogenic gain-of-function activities and exacerbate malignant properties of cancer cells, such as metastasis and drug resistance. Increasing evidence reveals that stabilization of mutant p53 in tumors is crucial for its oncogenic activities, while depletion of mutant p53 attenuates malignant properties of cancer cells. Thus, mutant p53 is an attractive druggable target for cancer therapy. Different approaches have been taken to develop small-molecule compounds that specifically target mutant p53. These include compounds that restore wild-type conformation and transcriptional activity of mutant p53, induce depletion of mutant p53, inhibit downstream pathways of oncogenic mutant p53, and induce synthetic lethality to mutant p53. In this review article, we comprehensively discuss the current strategies targeting oncogenic mutant p53 in cancers, with special focus on compounds that restore wild-type p53 transcriptional activity of mutant p53 and those reducing mutant p53 levels.

  7. An annotated database of Arabidopsis mutants of acyl lipid metabolism

    DOE PAGES

    McGlew, Kathleen; Shaw, Vincent; Zhang, Meng; ...

    2014-12-10

    Mutants have played a fundamental role in gene discovery and in understanding the function of genes involved in plant acyl lipid metabolism. The first mutant in Arabidopsis lipid metabolism (fad4) was described in 1985. Since that time, characterization of mutants in more than 280 genes associated with acyl lipid metabolism has been reported. This review provides a brief background and history on identification of mutants in acyl lipid metabolism, an analysis of the distribution of mutants in different areas of acyl lipid metabolism and presents an annotated database (ARALIPmutantDB) of these mutants. The database provides information on the phenotypes ofmore » mutants, pathways and enzymes/proteins associated with the mutants, and allows rapid access via hyperlinks to summaries of information about each mutant and to literature that provides information on the lipid composition of the mutants. Mutants for at least 30 % of the genes in the database have multiple names, which have been compiled here to reduce ambiguities in searches for information. Furthermore, the database should also provide a tool for exploring the relationships between mutants in acyl lipid-related genes and their lipid phenotypes and point to opportunities for further research.« less

  8. An annotated database of Arabidopsis mutants of acyl lipid metabolism

    SciTech Connect

    McGlew, Kathleen; Shaw, Vincent; Zhang, Meng; Kim, Ryeo Jin; Yang, Weili; Shorrosh, Basil; Suh, Mi Chung; Ohlrogge, John

    2014-12-10

    Mutants have played a fundamental role in gene discovery and in understanding the function of genes involved in plant acyl lipid metabolism. The first mutant in Arabidopsis lipid metabolism (fad4) was described in 1985. Since that time, characterization of mutants in more than 280 genes associated with acyl lipid metabolism has been reported. This review provides a brief background and history on identification of mutants in acyl lipid metabolism, an analysis of the distribution of mutants in different areas of acyl lipid metabolism and presents an annotated database (ARALIPmutantDB) of these mutants. The database provides information on the phenotypes of mutants, pathways and enzymes/proteins associated with the mutants, and allows rapid access via hyperlinks to summaries of information about each mutant and to literature that provides information on the lipid composition of the mutants. Mutants for at least 30 % of the genes in the database have multiple names, which have been compiled here to reduce ambiguities in searches for information. Furthermore, the database should also provide a tool for exploring the relationships between mutants in acyl lipid-related genes and their lipid phenotypes and point to opportunities for further research.

  9. Registration of two allelic erect leaf mutants of sorghum

    USDA-ARS?s Scientific Manuscript database

    Two allelic sorghum [Sorghum bicolor (L.) Moench] erect leaf (erl) mutants were isolated from an Annotated Individually-pedigreed Mutagenized Sorghum (AIMS) mutant library developed at the Plant Stress and Germplasm Development Unit, at Lubbock, Texas. The two mutants, erl1-1 and erl1-2, were isol...

  10. The enl mutants enhance the lrx1 root hair mutant phenotype of Arabidopsis thaliana.

    PubMed

    Diet, Anouck; Brunner, Susanne; Ringli, Christoph

    2004-06-01

    The development of root hairs serves as an excellent model to study cell growth using both cytological and genetic approaches. In the past, we have characterized LRX1, an extracellular protein of Arabidopsis consisting of an LRR-domain and a structural extensin domain. LRX1 is specifically expressed in root hairs and lrx1 mutants show severe deficiencies in root hair development. In this work, we describe the characterization of enl (enhancer of lrx1) mutants that were isolated in a visual screen of an ethylmethanesulfonate -mutagenized lrx1 line for plants exhibiting an enhanced lrx1 phenotype. Four recessive enl mutants were analyzed, three of which define new genetic loci involved in root hair development. The mutations at the enl loci and lrx1 result in additive phenotypes in enl/lrx1 double mutants. One enl mutant is affected in the ACTIN2 gene and encodes a protein with a 22 amino acid deletion at the C-terminus. The comparison of molecular and phenotypic data of different actin2 alleles suggests that the truncated ACTIN2 protein is still partially functional.

  11. Characteristics of Late Negative ERG Responses Elicited By Sawtooth Flicker

    PubMed Central

    Gowrisankaran, Sowjanya; Genead, Mohamed A.; Anastasakis, Anastasios; Alexander, Kenneth R.

    2012-01-01

    Background This study aimed to determine whether the properties of the late negative responses (LNRs) of the electroretinogram (ERG) elicited by sawtooth flicker are consistent with the characteristics of the photopic negative response generated by a light pulse (PhNRpulse). Methods ERG recordings were obtained from 10 visually normal individuals and from 6 patients with optic atrophy (OA) in response to 8-Hz rapid-on and rapid-off sawtooth flicker and to brief (4 ms) light pulses. All stimuli were either long-wavelength (R), middle-wavelength (G), or a combination of equal luminances of long and middle-wavelengths (Y) presented on a short-wavelength, rod-saturating adapting field. Amplitudes of LNRs were obtained in response to rapid-on (LNRon) and rapid-off (LNRoff) sawtooth flicker, and were also derived from the sum of the ERG waveforms to the two sawtooth phases (LNRadd). Results For the control subjects, PhNRpulse amplitude varied with stimulus wavelength, being largest in response to a long-wavelength pulse, as expected. However, the amplitudes of LNRon, LNRoff, and LNRadd were not significantly different for R, Y, and G sawtooth flicker. Despite the absence of a chromatic effect, LNRoff and LNRadd amplitudes were significantly smaller in the OA patients than in the controls, similar to the results for the PhNRpulse, implying an inner retinal origin for the LNRoff and LNRadd. However, LNRon amplitudes did not differ significantly between the OA patients and controls, although there was a significant correlation between the LNRon and PhNRpulse for R stimuli. Conclusion We conclude that LNRoff and LNRadd but not LNRon can be useful measures to assess the integrity of the inner retina that can complement the PhNRpulse. PMID:23054159

  12. Role of phosphodiesterase-4 on ethanol elicited locomotion and narcosis.

    PubMed

    Baliño, Pablo; Ledesma, Juan Carlos; Aragon, Carlos M G

    2016-02-01

    The cAMP signaling pathway has emerged as an important modulator of the pharmacological effects of ethanol. In this respect, the cAMP-dependent protein kinase has been shown to play an important role in the modulation of several ethanol-induced behavioral actions. Cellular levels of cAMP are maintained by the activity of adenylyl cyclases and phosphodiesterases. In the present work we have focused on ascertaining the role of PDE4 in mediating the neurobehavioral effects of ethanol. For this purpose, we have used the selective PDE4 inhibitor Ro 20-1724. This compound has been proven to enhance cellular cAMP response by PDE4 blockade and can be administered systemically. Swiss mice were injected intraperitoneally (i.p.) with Ro 20-1724 (0-5 mg/kg; i.p.) at different time intervals before ethanol (0-4 g/kg; i.p.) administration. Immediately after the ethanol injection, locomotor activity, loss of righting reflex, PKA footprint and enzymatic activity were assessed. Pretreatment with Ro 20-1724 increased ethanol-induced locomotor stimulation in a dose-dependent manner. Doses that increased locomotor stimulation did not modify basal locomotion or the suppression of motor activity produced by high doses of this alcohol. Ro 20-1724 did not alter the locomotor activation produced by amphetamine or cocaine. The time of loss of righting reflex evoked by ethanol was increased after pretreatment with Ro 20-1724. This effect was selective for the narcotic effects of ethanol since Ro 20-1724 did not affect pentobarbital-induced narcotic effects. Moreover, Ro 20-1724 administration increased the PKA footprint and enzymatic activity response elicited by ethanol. These data provide further evidence of the key role of the cAMP signaling pathway in the central effects of ethanol.

  13. Feeding-elicited cataplexy in orexin knockout mice.

    PubMed

    Clark, E L; Baumann, C R; Cano, G; Scammell, T E; Mochizuki, T

    2009-07-21

    Mice lacking orexin/hypocretin signaling have sudden episodes of atonia and paralysis during active wakefulness. These events strongly resemble cataplexy, episodes of sudden muscle weakness triggered by strong positive emotions in people with narcolepsy, but it remains unknown whether murine cataplexy is triggered by positive emotions. To determine whether positive emotions elicit murine cataplexy, we placed orexin knockout (KO) mice on a scheduled feeding protocol with regular or highly palatable food. Baseline sleep/wake behavior was recorded with ad libitum regular chow. Mice were then placed on a scheduled feeding protocol in which they received 60% of their normal amount of chow 3 h after dark onset for the next 10 days. Wild-type and KO mice rapidly entrained to scheduled feeding with regular chow, with more wake and locomotor activity prior to the feeding time. On day 10 of scheduled feeding, orexin KO mice had slightly more cataplexy during the food-anticipation period and more cataplexy in the second half of the dark period, when they may have been foraging for residual food. To test whether more palatable food increases cataplexy, mice were then switched to scheduled feeding with an isocaloric amount of Froot Loops, a food often used as a reward in behavioral studies. With this highly palatable food, orexin KO mice had much more cataplexy during the food-anticipation period and throughout the dark period. The increase in cataplexy with scheduled feeding, especially with highly palatable food, suggests that positive emotions may trigger cataplexy in mice, just as in people with narcolepsy. Establishing this connection helps validate orexin KO mice as an excellent model of human narcolepsy and provides an opportunity to better understand the mechanisms that trigger cataplexy.

  14. Functional changes in the snail statocyst system elicited by microgravity.

    PubMed

    Balaban, Pavel M; Malyshev, Aleksey Y; Ierusalimsky, Victor N; Aseyev, Nikolay; Korshunova, Tania A; Bravarenko, Natasha I; Lemak, M S; Roshchin, Matvey; Zakharov, Igor S; Popova, Yekaterina; Boyle, Richard

    2011-03-29

    The mollusk statocyst is a mechanosensing organ detecting the animal's orientation with respect to gravity. This system has clear similarities to its vertebrate counterparts: a weight-lending mass, an epithelial layer containing small supporting cells and the large sensory hair cells, and an output eliciting compensatory body reflexes to perturbations. In terrestrial gastropod snail we studied the impact of 16- (Foton M-2) and 12-day (Foton M-3) exposure to microgravity in unmanned orbital missions on: (i) the whole animal behavior (Helix lucorum L.), (ii) the statoreceptor responses to tilt in an isolated neural preparation (Helix lucorum L.), and (iii) the differential expression of the Helix pedal peptide (HPep) and the tetrapeptide FMRFamide genes in neural structures (Helix aspersa L.). Experiments were performed 13-42 hours after return to Earth. Latency of body re-orientation to sudden 90° head-down pitch was significantly reduced in postflight snails indicating an enhanced negative gravitaxis response. Statoreceptor responses to tilt in postflight snails were independent of motion direction, in contrast to a directional preference observed in control animals. Positive relation between tilt velocity and firing rate was observed in both control and postflight snails, but the response magnitude was significantly larger in postflight snails indicating an enhanced sensitivity to acceleration. A significant increase in mRNA expression of the gene encoding HPep, a peptide linked to ciliary beating, in statoreceptors was observed in postflight snails; no differential expression of the gene encoding FMRFamide, a possible neurotransmission modulator, was observed. Upregulation of statocyst function in snails following microgravity exposure parallels that observed in vertebrates suggesting fundamental principles underlie gravi-sensing and the organism's ability to adapt to gravity changes. This simple animal model offers the possibility to describe general

  15. Functional Changes in the Snail Statocyst System Elicited by Microgravity

    PubMed Central

    Balaban, Pavel M.; Malyshev, Aleksey Y.; Ierusalimsky, Victor N.; Aseyev, Nikolay; Korshunova, Tania A.; Bravarenko, Natasha I.; Lemak, M. S.; Roshchin, Matvey; Zakharov, Igor S.; Popova, Yekaterina; Boyle, Richard

    2011-01-01

    Background The mollusk statocyst is a mechanosensing organ detecting the animal's orientation with respect to gravity. This system has clear similarities to its vertebrate counterparts: a weight-lending mass, an epithelial layer containing small supporting cells and the large sensory hair cells, and an output eliciting compensatory body reflexes to perturbations. Methodology/Principal Findings In terrestrial gastropod snail we studied the impact of 16- (Foton M-2) and 12-day (Foton M-3) exposure to microgravity in unmanned orbital missions on: (i) the whole animal behavior (Helix lucorum L.), (ii) the statoreceptor responses to tilt in an isolated neural preparation (Helix lucorum L.), and (iii) the differential expression of the Helix pedal peptide (HPep) and the tetrapeptide FMRFamide genes in neural structures (Helix aspersa L.). Experiments were performed 13–42 hours after return to Earth. Latency of body re-orientation to sudden 90° head-down pitch was significantly reduced in postflight snails indicating an enhanced negative gravitaxis response. Statoreceptor responses to tilt in postflight snails were independent of motion direction, in contrast to a directional preference observed in control animals. Positive relation between tilt velocity and firing rate was observed in both control and postflight snails, but the response magnitude was significantly larger in postflight snails indicating an enhanced sensitivity to acceleration. A significant increase in mRNA expression of the gene encoding HPep, a peptide linked to ciliary beating, in statoreceptors was observed in postflight snails; no differential expression of the gene encoding FMRFamide, a possible neurotransmission modulator, was observed. Conclusions/Significance Upregulation of statocyst function in snails following microgravity exposure parallels that observed in vertebrates suggesting fundamental principles underlie gravi-sensing and the organism's ability to adapt to gravity changes. This

  16. Designedly Incomplete Utterances: A Pedagogical Practice for Eliciting Knowledge Displays in Error Correction Sequences.

    ERIC Educational Resources Information Center

    Koshik, Irene

    2002-01-01

    Uses a conversation analytic framework to analyze a practice used by teachers in 1-0-1, second language writing conferences when eliciting self-correction of students' written language errors. This type of turn used to elicit a knowledge display from the student is labeled designedly incomplete utterance (DIU). Teachers use DIUs made up of…

  17. Model-Eliciting Activities (MEAs) as a Bridge between Engineering Education Research and Mathematics Education Research

    ERIC Educational Resources Information Center

    Hamilton, Eric; Lesh, Richard; Lester, Frank; Brilleslyper, Michael

    2008-01-01

    This article introduces Model-Eliciting Activities (MEAs) as a form of case study team problem-solving. MEA design focuses on eliciting from students conceptual models that they iteratively revise in problem-solving. Though developed by mathematics education researchers to study the evolution of mathematical problem-solving expertise in middle…

  18. Salient Beliefs in Majoring in Management Information Systems: An Elicitation Study

    ERIC Educational Resources Information Center

    Chipidza, Wallace; Green, Gina; Riemenschneider, Cindy

    2016-01-01

    Research utilizing the Theory of Planned Behavior to understand behavior should first elicit beliefs about the phenomenon from the target population. In order to understand the reasons why students choose to major or not major in Management Information Systems (MIS), we elicited beliefs from 136 students attending university in the United States…

  19. Photo-Elicitation and Visual Semiotics: A Unique Methodology for Studying Inclusion for Children with Disabilities

    ERIC Educational Resources Information Center

    Stockall, Nancy

    2013-01-01

    The methodology in this paper discusses the use of photographs as an elicitation strategy that can reveal the thinking processes of participants in a qualitatively rich manner. Photo-elicitation techniques combined with a Piercian semiotic perspective offer a unique method for creating a frame of action for later participant analysis. Illustrative…

  20. Concurrent Data Elicitation Procedures, Processes, and the Early Stages of L2 Learning: A Critical Overview

    ERIC Educational Resources Information Center

    Leow, Ronald P.; Grey, Sarah; Marijuan, Silvia; Moorman, Colleen

    2014-01-01

    Given the current methodological interest in eliciting direct data on the cognitive processes L2 learners employ as they interact with L2 data during the early stages of the learning process, this article takes a critical and comparative look at three concurrent data elicitation procedures currently employed in the SLA literature: Think aloud (TA)…

  1. Identifying and Responding to Personal Stressors: Utilizing Photo Elicitation in Health Education Courses

    ERIC Educational Resources Information Center

    Hunter, Theresa

    2014-01-01

    The "Photo Elicitation Project" teaching idea applies the techniques of photo elicitation to stress prevention and management. This activity is designed to help students identify their personal stressors and to determine which stress prevention strategies are most useful for them. Objectives: students will be able to (a) identify current…

  2. Uncovering Pre-Service Teacher Beliefs about Young Children: A Photographic Elicitation Methodology

    ERIC Educational Resources Information Center

    Stockall, Nancy; Davis, Sara

    2011-01-01

    This illustrative paper provides an introduction to using mixed qualitative methods of photo-elicitation, face to face interviews and semiotic analysis to uncover pre-service students' beliefs about young children. The researchers share their experience on conducting a study using photo-elicitation and engaging pre-service teachers in a discussion…

  3. Naturalistic Observations of Elicited Expressive Communication of Children with Autism: An Analysis of Teacher Instructions

    ERIC Educational Resources Information Center

    Chiang, Hsu-Min

    2009-01-01

    This study observed expressive communication of 17 Australian and 15 Taiwanese children with autism who were mute or had limited spoken language during 2 hour regular school routines and analyzed teacher instructions associated with elicited expressive communication. Results indicated: (a) the frequency of occurrence of elicited expressive…

  4. Effects of Race and Dialect of Examiner on Language Samples Elicited from Southern African American Preschoolers.

    ERIC Educational Resources Information Center

    Agerton, Emily P.; Moran, Michael J.

    1995-01-01

    Language samples were elicited from 17 African American preschoolers by 3 examiners; a white female using standard English and 2 African American females using either standard English or black English. Samples elicited by the African American examiners contained more different Black English features, with examiner usage of Black English eliciting…

  5. Stone Soup: Photo-Elicitation as a Learning Tool in the Food Geography Classroom

    ERIC Educational Resources Information Center

    Kurtz, Hilda E.; Wood, Jason

    2014-01-01

    This paper showcases self-reflective and inclusive pedagogy using photo-elicitation in a food geography course assignment. The Stone Soup project positions students as both researchers and participant-subjects in a participant-driven photo-elicitation (PDPE) study of students' foodways. Student papers for this assignment demonstrate rich…

  6. Eliciting Covert Mental Operations, Concepts and Oral Language Skills in Young Bilingual Children.

    ERIC Educational Resources Information Center

    Hollomon, John W.; And Others

    The purpose of this investigation was to design and test an information-eliciting question instrument in order to determine whether the structures in the verbal responses of young Mexican-American, bilingual children entering school would reveal the covert mental operations, concepts and oral language skills elicited. The basic objective was to…

  7. Stone Soup: Photo-Elicitation as a Learning Tool in the Food Geography Classroom

    ERIC Educational Resources Information Center

    Kurtz, Hilda E.; Wood, Jason

    2014-01-01

    This paper showcases self-reflective and inclusive pedagogy using photo-elicitation in a food geography course assignment. The Stone Soup project positions students as both researchers and participant-subjects in a participant-driven photo-elicitation (PDPE) study of students' foodways. Student papers for this assignment demonstrate rich…

  8. Visualising community: using participant-driven photo-elicitation for research and application

    Treesearch

    Paul M. Van Auken; Svein J. Frisvoll; Susan I. Stewart

    2010-01-01

    Despite a contemporary socio-culture revolving around cultural consumption of imagery, metaphors, representations and "gaze", photo-elicitation is a rarely used method for social scientists and planners to acquire knowledge. In this paper, we discuss participant-driven photo-elicitation, a process in which participant photos are paired with in-depth...

  9. Translation Elicitation Techniques and Mother-Tongue Interference: Any Significant Connection?

    ERIC Educational Resources Information Center

    Mattar, Hameed

    1999-01-01

    Examined the validity of Dulay, Burt, and Krashen's hypothesis that the use of translation as an elicitation technique in foreign or second language (L2) research artificially increases L2 learners' reliance on the mother tongue, and accordingly, the proportion of interference errors. Examined interference errors on two elicitation tasks: an…

  10. Photo-Elicitation and Visual Semiotics: A Unique Methodology for Studying Inclusion for Children with Disabilities

    ERIC Educational Resources Information Center

    Stockall, Nancy

    2013-01-01

    The methodology in this paper discusses the use of photographs as an elicitation strategy that can reveal the thinking processes of participants in a qualitatively rich manner. Photo-elicitation techniques combined with a Piercian semiotic perspective offer a unique method for creating a frame of action for later participant analysis. Illustrative…

  11. Uncovering Pre-Service Teacher Beliefs about Young Children: A Photographic Elicitation Methodology

    ERIC Educational Resources Information Center

    Stockall, Nancy; Davis, Sara

    2011-01-01

    This illustrative paper provides an introduction to using mixed qualitative methods of photo-elicitation, face to face interviews and semiotic analysis to uncover pre-service students' beliefs about young children. The researchers share their experience on conducting a study using photo-elicitation and engaging pre-service teachers in a discussion…

  12. From Drawings to Diagrams: Maintaining Researcher Control during Graphic Elicitation in Qualitative Interviews

    ERIC Educational Resources Information Center

    Varga-Atkins, Tunde; O'Brien, Mark

    2009-01-01

    Graphic elicitation, i.e. asking participants to draw, is an interview technique used to focus the interviewee on the given topic or gain extra meaning not covered verbally as part of the interview. This study analyses two interview contexts which included visual elicitation. It describes a successful example in which the researcher maintained…

  13. Concurrent Data Elicitation Procedures, Processes, and the Early Stages of L2 Learning: A Critical Overview

    ERIC Educational Resources Information Center

    Leow, Ronald P.; Grey, Sarah; Marijuan, Silvia; Moorman, Colleen

    2014-01-01

    Given the current methodological interest in eliciting direct data on the cognitive processes L2 learners employ as they interact with L2 data during the early stages of the learning process, this article takes a critical and comparative look at three concurrent data elicitation procedures currently employed in the SLA literature: Think aloud (TA)…

  14. Meningococcal outer membrane vesicle vaccines derived from mutant strains engineered to express factor H binding proteins from antigenic variant groups 1 and 2.

    PubMed

    Koeberling, Oliver; Giuntini, Serena; Seubert, Anja; Granoff, Dan M

    2009-02-01

    Meningococcal outer membrane vesicle (OMV) vaccines, which are treated with detergents to decrease endotoxin activity, are safe and effective in humans. However, the vaccines elicit serum bactericidal antibody responses largely directed against PorA, which is antigenically variable. We previously prepared a native (non-detergent-treated) OMV vaccine from a mutant of group B strain H44/76 in which the lpxL1 gene was inactivated, which resulted in penta-acylated lipid A with attenuated endotoxin activity. To enhance protection, we overexpressed factor H binding protein (fHbp) from the antigenic variant 1 group. The vaccine elicited broad serum bactericidal antibody responses in mice against strains with fHbp variant 1 (approximately 70% of group B isolates) but not against strains with variant 2 or 3. In the present study, we constructed a mutant of group B strain NZ98/254 with attenuated endotoxin that expressed both endogenous variant 1 and heterologous fHbp variant 2. A mixture of the two native OMV vaccines from the H44/76 and NZ98/254 mutants stimulated proinflammatory cytokine responses by human peripheral blood mononuclear cells similar to those stimulated by control, detergent-treated OMV vaccines from the wild-type strains. In mice, the mixture of the two native OMV vaccines elicited broad serum bactericidal antibody responses against strains with heterologous PorA and fHbp in the variant 1, 2, or 3 group. By adsorption studies, the principal bactericidal antibody target was determined to be fHbp. Thus, native OMV vaccines from mutants expressing fHbp variants have the potential to be safe for humans and to confer broad protection against meningococcal disease from strains expressing fHbp from each of the antigenic variant groups.

  15. HMBPP-deficient Listeria mutant immunization alters pulmonary/systemic responses, effector functions, and memory polarization of Vγ2Vδ2 T cells

    PubMed Central

    Frencher, James T.; Shen, Hongbo; Yan, Lin; Wilson, Jessica O.; Freitag, Nancy E.; Rizzo, Alicia N.; Chen, Crystal Y.; Chen, Zheng W.

    2014-01-01

    Whereas infection or immunization of humans/primates with microbes coproducing HMBPP/IPP can remarkably activate Vγ2Vδ2 T cells, in vivo studies have not been done to dissect HMBPP- and IPP-driven expansion, pulmonary trafficking, effector functions, and memory polarization of Vγ2Vδ2 T cells. We define these phosphoantigen-host interplays by comparative immunizations of macaques with the HMBPP/IPP-coproducing Listeria ΔactA prfA* and HMBPP-deficient Listeria ΔactAΔgcpE prfA* mutant. The HMBPP-deficient ΔgcpE mutant shows lower ability to expand Vγ2Vδ2 T cells in vitro than the parental HMBPP-producing strain but displays comparably attenuated infectivity or immunogenicity. Respiratory immunization of macaques with the HMBPP-deficient mutant elicits lower pulmonary and systemic responses of Vγ2Vδ2 T cells compared with the HMBPP-producing vaccine strain. Interestingly, HMBPP-deficient mutant reimmunization or boosting elicits enhanced responses of Vγ2Vδ2 T cells, but the magnitude is lower than that by HMBPP-producing listeria. HMBPP-deficient listeria differentiated fewer Vγ2Vδ2 T effector cells capable of coproducing IFN-γ and TNF-α and inhibiting intracellular listeria than HMBPP-producing listeria. Furthermore, HMBPP deficiency in listerial immunization influences memory polarization of Vγ2Vδ2 T cells. Thus, both HMBPP and IPP production in listerial immunization or infection elicit systemic/pulmonary responses and differentiation of Vγ2Vδ2 T cells, but a role for HMBPP is more dominant. Findings may help devise immune intervention. PMID:25114162

  16. A comparison of two procedures to elicit verbal auxiliary and copula in normal kindergarten children.

    PubMed

    Hughes, D; Till, J A

    1982-08-01

    Fourteen normal kindergarten children, all of whom spontaneously used verbal auxiliary and copular forms of BE (VACs) were studied. Two cloze procedures were designed to elicit all three forms of present tense VACs in uncontractible sentence positions. The syntactic elicitation (SE) procedure required the children to observe a syntactic constraint within a descriptive response; the emphatic elicitation (EE) procedure required observation of a stress constraint within a role-playing response. Personal pronouns were used as sentence subjects in both procedures. Results indicated that both procedures were effective in eliciting VACs approximately 75% of the time. The SE procedure was more effective than the EE procedure overall. The procedures did not differ in their ability to elicit auxiliary and copular forms. The effects of subject pronoun person and singular vs. plural verb form are discussed. The procedures have implications for supplementing spontaneous language samples in assessing expressive language.

  17. Comparison of elicitation methods for moral and affective beliefs in the theory of planned behaviour.

    PubMed

    Dean, M; Arvola, A; Vassallo, M; Lähteenmäki, L; Raats, M M; Saba, A; Shepherd, R

    2006-09-01

    Although the theory of planned behaviour (TPB) has been applied successfully in the area of food choice, it has been criticized for its pure utilitarian approach to the factors determining behaviour. Despite the increase in predictive power of the model with added components such as affective attitude and moral and ethical concerns, in most studies the elicitation process still only addresses people's utilitarian beliefs about the behaviour with little attention paid to other aspects. This study compares the traditional method of elicitation of advantages and disadvantages with two other methods (word association and open-ended) in the elicitations of beliefs, attitudes and moral concerns in relation to the consumption of organic foods. Results show the traditional method to be best for eliciting cognitive beliefs, open-ended emotion task for eliciting emotional beliefs and open-ended beliefs task best for moral concerns. The advantages and disadvantages of each method are discussed.

  18. Metaphors of Distress: Photo-Elicitation Enhances a Discourse Analysis of Parents' Accounts.

    PubMed

    Kantrowitz-Gordon, Ira; Vandermause, Roxanne

    2016-07-01

    In research on sensitive topics, photo-elicitation can be a profound aid to data collection and interpretation processes. Photo-elicitation methods were used in this manner in a discourse analysis of parents' distress at least 6 months after preterm birth. After an initial interview, participants were asked to take digital photographs representing their distress and to return for a second interview to discuss the photographs. The elicited photo representations supported participants' engagement with their current or past distress and generated new meanings from the reappraisal of old photographs. Photo-elicitation demonstrated the embodiment of parents' distress in the child and the placement of distress in specific locations. Photographs of documents showed the power of the written word in generating and maintaining distress. Participants used existing photographs from their child's photo history to generate rich metaphors for their distress as parents. These findings have implications for enhancing interpretive health research by incorporating photo-elicitation methods.

  19. Enhanced cell-specific ablation in zebrafish using a triple mutant of Escherichia coli nitroreductase.

    PubMed

    Mathias, Jonathan R; Zhang, Zhanying; Saxena, Meera T; Mumm, Jeff S

    2014-04-01

    Transgenic expression of bacterial nitroreductase (NTR) facilitates chemically-inducible targeted cell ablation. In zebrafish, the NTR system enables studies of cell function and cellular regeneration. Metronidazole (MTZ) has become the most commonly used prodrug substrate for eliciting cell loss in NTR-expressing transgenic zebrafish due to the cell-specific nature of its cytotoxic derivatives. Unfortunately, MTZ treatments required for effective cell ablation border toxic effects, and, thus, likely incur undesirable nonspecific effects. Here, we tested whether a triple mutant variant of NTR, previously shown to display improved activity in bacterial assays, can solve this issue by promoting cell ablation in zebrafish using reduced prodrug treatment regimens. We generated several complementary transgenic zebrafish lines expressing either wild-type or mutant NTR (mutNTR) in specific neural cell types, and assayed prodrug-induced cell ablation kinetics using confocal time series imaging and plate reader-based quantification of fluorescent reporters expressed in targeted cell types. The results show that cell ablation can be achieved in mutNTR expressing transgenic lines with markedly shortened prodrug exposure times and/or at lower prodrug concentrations. The mutNTR variant characterized here can circumvent problematic nonspecific/toxic effects arising from low prodrug conversion efficiency, thus increasing the effectiveness and versatility of this selective cell ablation methodology.

  20. EZH2 inhibition sensitizes BRG1 and EGFR mutant lung tumors to TopoII inhibitors

    PubMed Central

    Fillmore, Christine M.; Xu, Chunxiao; Desai, Pooja T.; Berry, Joanne M.; Rowbotham, Samuel P.; Lin, Yi-Jang; Zhang, Haikuo; Marquez, Victor E.; Hammerman, Peter S.; Wong, Kwok-Kin; Kim, Carla F.

    2014-01-01

    SUMMARY Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide1. Chemotherapies such as the topoisomerase II inhibitor (TopoIIi) etoposide effectively reduce disease in a minority of NSCLC patients2,3; therefore, alternative drug targets, including epigenetic enzymes, are under consideration for therapeutic intervention4. A promising potential epigenetic target is the methyltransferase EZH2, which in the context of the Polycomb Repressive Complex 2 (PRC2) is well known to tri-methylate Histone H3 at lysine 27 (H3K27me3) and elicit gene silencing5. Here, we demonstrate that EZH2 inhibition (EZH2i) had differential effects on TopoIIi response of NSCLCs in vitro and in vivo. EGFR and BRG1 mutations were genetic biomarkers that predicted enhanced sensitivity to TopoIIi in response to EZH2i. BRG1 loss-of-function mutant tumors responded to EZH2i with increased S phase, anaphase bridging, apoptosis, and TopoIIi sensitivity. Conversely, EGFR and BRG1 wild-type tumors up-regulated BRG1 in response to EZH2i and ultimately became more resistant to TopoIIi. EGFR gain-of-function mutant tumors were also sensitive to dual EZH2i and TopoIIi, due to genetic antagonism between EGFR and BRG1. These findings suggest an exciting opportunity for precision medicine in the genetically complex disease of NSCLC. PMID:25629630

  1. Monkey electrophysiological and human psychophysical responses to mutants of the sweet protein brazzein: delineating brazzein sweetness.

    PubMed

    Jin, Zheyuan; Danilova, Vicktoria; Assadi-Porter, Fariba M; Markley, John L; Hellekant, Göran

    2003-07-01

    Responses to brazzein, 25 brazzein mutants and two forms of monellin were studied in two types of experiments: electrophysiological recordings from chorda tympani S fibers of the rhesus monkey, Macaca mulatta, and psychophysical experiments. We found that different mutations at position 29 (changing Asp29 to Ala, Lys or Asn) made the molecule significantly sweeter than brazzein, while mutations at positions 30 or 33 (Lys30Asp or Arg33Ala) removed all sweetness. The same pattern occurred again at the beta-turn region, where Glu41Lys gave the highest sweetness score among the mutants tested, whereas a mutation two residues distant (Arg43Ala) abolished the sweetness. The effects of charge and side chain size were examined at two locations, namely positions 29 and 36. The findings indicate that charge is important for eliciting sweetness, whereas the length of the side-chain plays a lesser role. We also found that the N- and C-termini are important for the sweetness of brazzein. The close correlation (r = 0.78) between the results of the above two methods corroborates our hypothesis that S fibers convey sweet taste in primates.

  2. Structural signatures of DRD4 mutants revealed using molecular dynamics simulations: Implications for drug targeting.

    PubMed

    Jatana, Nidhi; Thukral, Lipi; Latha, N

    2016-01-01

    Human Dopamine Receptor D4 (DRD4) orchestrates several neurological functions and represents a target for many psychological disorders. Here, we examined two rare variants in DRD4; V194G and R237L, which elicit functional alterations leading to disruption of ligand binding and G protein coupling, respectively. Using atomistic molecular dynamics (MD) simulations, we provide in-depth analysis to reveal structural signatures of wild and mutant complexes with their bound agonist and antagonist ligands. We constructed intra-protein network graphs to discriminate the global conformational changes induced by mutations. The simulations also allowed us to elucidate the local side-chain dynamical variations in ligand-bound mutant receptors. The data suggest that the mutation in transmembrane V (V194G) drastically disrupts the organization of ligand binding site and causes disorder in the native helical arrangement. Interestingly, the R237L mutation leads to significant rewiring of side-chain contacts in the intracellular loop 3 (site of mutation) and also affects the distant transmembrane topology. Additionally, these mutations lead to compact ICL3 region compared to the wild type, indicating that the receptor would be inaccessible for G protein coupling. Our findings thus reveal unreported structural determinants of the mutated DRD4 receptor and provide a robust framework for design of effective novel drugs.

  3. Molecular pathogenesis of Spondylocheirodysplastic Ehlers-Danlos syndrome caused by mutant ZIP13 proteins

    PubMed Central

    Bin, Bum-Ho; Hojyo, Shintaro; Hosaka, Toshiaki; Bhin, Jinhyuk; Kano, Hiroki; Miyai, Tomohiro; Ikeda, Mariko; Kimura-Someya, Tomomi; Shirouzu, Mikako; Cho, Eun-Gyung; Fukue, Kazuhisa; Kambe, Taiho; Ohashi, Wakana; Kim, Kyu-Han; Seo, Juyeon; Choi, Dong-Hwa; Nam, Yeon-Ju; Hwang, Daehee; Fukunaka, Ayako; Fujitani, Yoshio; Yokoyama, Shigeyuki; Superti-Furga, Andrea; Ikegawa, Shiro; Lee, Tae Ryong; Fukada, Toshiyuki

    2014-01-01

    The zinc transporter protein ZIP13 plays critical roles in bone, tooth, and connective tissue development, and its dysfunction is responsible for the spondylocheirodysplastic form of Ehlers-Danlos syndrome (SCD-EDS, OMIM 612350). Here, we report the molecular pathogenic mechanism of SCD-EDS caused by two different mutant ZIP13 proteins found in human patients: ZIP13G64D, in which Gly at amino acid position 64 is replaced by Asp, and ZIP13ΔFLA, which contains a deletion of Phe-Leu-Ala. We demonstrated that both the ZIP13G64D and ZIP13ΔFLA protein levels are decreased by degradation via the valosin-containing protein (VCP)-linked ubiquitin proteasome pathway. The inhibition of degradation pathways rescued the protein expression levels, resulting in improved intracellular Zn homeostasis. Our findings uncover the pathogenic mechanisms elicited by mutant ZIP13 proteins. Further elucidation of these degradation processes may lead to novel therapeutic targets for SCD-EDS. PMID:25007800

  4. Retinal degeneration mutants in the mouse.

    PubMed

    Chang, B; Hawes, N L; Hurd, R E; Davisson, M T; Nusinowitz, S; Heckenlively, J R

    2002-02-01

    The Jackson Laboratory, having the world's largest collection of mouse mutant stocks and genetically diverse inbred strains, is an ideal place to look for genetically determined eye variations and disorders. Through ophthalmoscopy, electroretinography and histology, we have discovered disorders affecting all aspects of the eye including the lid, cornea, iris, lens and retina, resulting in corneal disorders, cataracts, glaucoma and retinal degenerations. Mouse models of retinal degeneration have been investigated for many years in the hope of understanding the causes of photoreceptor cell death. Sixteen naturally occurring mouse mutants that manifest degeneration of photoreceptors in the retina with preservation of all other retinal cell types have been found: retinal degeneration (formerly rd, identical with rodless retina, r, now Pde6b(rd1)); Purkinje cell degeneration (pcd); nervous (nr); retinal degeneration slow (rds, now Prph(Rd2)); retinal degeneration 3 (rd3); motor neuron degeneration (mnd); retinal degeneration 4 (Rd4); retinal degeneration 5 (rd5, now tub); vitiligo (vit, now Mitf(mi-vit)); retinal degeneration 6 (rd6); retinal degeneration 7 (rd7, now Nr2e3(rd7)); neuronal ceroid lipofuscinosis (nclf); retinal degeneration 8 (rd8); retinal degeneration 9 (Rd9); retinal degeneration 10 (rd10, now Pde6b(rd10)); and cone photoreceptor function loss (cpfl1). In this report, we first review the genotypes and phenotypes of these mutants and second, list the mouse strains that carry each mutation. We will also provide detailed information about the cpfl1 mutation. The phenotypic characteristics of cpfl1 mice are similar to those observed in patients with complete achromatopsia (ACHM2, OMIM 216900) and the cpfl1 mutation is the first naturally-arising mutation in mice to cause cone-specific photoreceptor function loss. cpfl1 mice may provide a model for congenital achromatopsia in humans.

  5. Reward learning in normal and mutant Drosophila

    PubMed Central

    Tempel, Bruce L.; Bonini, Nancy; Dawson, Douglas R.; Quinn, William G.

    1983-01-01

    Hungry fruit flies can be trained by exposing them to two chemical odorants, one paired with the opportunity to feed on 1 M sucrose. On later testing, when given a choice between odorants the flies migrate specifically toward the sucrose-paired odor. This appetitively reinforced learning by the flies is similar in strength and character to previously demonstrated negatively reinforced learning, but it differs in several properties. Both memory consolidation and memory decay proceed relatively slowly after training with sucrose reward. Consolidation of learned information into anesthesia-resistant long-term memory requires about 100 min after training with sucrose compared to about 30 min after training with electric shock. Memory in wild-type flies persists for 24 hr after training with sucrose compared to 4-6 hr after training with electric shock. Memory in amnesiac mutants appears to be similarly lengthened, from 1 hr to 6 hr, by substituting sucrose reward for shock punishment. Two other mutants, dunce and rutabaga, which were isolated because they failed to learn the shock-avoidance task, learn normally in response to sucrose reward but forget rapidly afterward. One mutant, turnip, does not learn in either paradigm. Reward and punishment can be combined in olfactory discrimination training by pairing one odor to sucrose and the other to electric shock. In this situation, the expression of learning is approximately the sum of that obtained by using either reinforcement alone. After such training, memory decays at two distinct rates, each characteristic of one type of reinforcement. PMID:6572401

  6. What monitor can replace the cathode-ray tube for visual stimulation to elicit multifocal electroretinograms?

    PubMed

    Matsumoto, Celso Soiti; Shinoda, Kei; Matsumoto, Harue; Seki, Keisuke; Nagasaka, Eiichiro; Iwata, Takeshi; Mizota, Atsushi

    2014-08-05

    To compare a conventional cathode-ray tube (CRT) screen to organic light-emitting diode (OLED) and liquid crystal display (LCD) screens as visual stimulators to elicit multifocal electroretinograms (mfERGs), mfERGs were recorded from seven eyes of seven healthy volunteers (21 ± 2 years). The mfERGs elicited by a conventional CRT screen (S710, Compaq Computer Co.) were compared to those elicited by a studio-grade master OLED monitor (PVM-1741, Sony, Japan) and a conventional LCD (S1721, Flexscan, Eizo Nanao Corp., Japan). The luminance changes of each monitor were measured with a photodiode. CRT, OLED, and LCD screens with a frame frequency of 60 Hz were studied. A hexagonal stimulus array with 61 stimulus elements was created on each monitor. The serial white stimuli of the OLED screen at 60 Hz did not fuse, and that of the LCD screens fused. The amplitudes of P1 and P2 of the first-order kernels of the mfERGs were not significantly different from those elicited by the CRT and OLED screens, and the P1 amplitude of the first-order kernel elicited by the LCD stimuli was significantly smaller than that elicited by the CRT in all the groups of the averaged hexagonal elements. The implicit times were approximately 10 ms longer in almost all components elicited by the LCD screen compared to those elicited by the CRT screen. The mfERGs elicited by monitors other than the CRT should be carefully interpreted, especially those elicited by LCD screens. The OLED had good performance, and we conclude that it can replace the CRT as a stimulator for mfERGs; however, a collection of normative data is recommended. © 2014 ARVO.

  7. Salmonella Typhimurium TTSS-2 deficient mig-14 mutant shows attenuation in immunocompromised mice and offers protection against wild-type Salmonella Typhimurium infection.

    PubMed

    Pati, Niladri Bhusan; Vishwakarma, Vikalp; Selvaraj, Sathish Kumar; Dash, Sabyasachi; Saha, Bhaskar; Singh, Neera; Suar, Mrutyunjay

    2013-10-22

    Development of Salmonella enterica serovar Typhimurium (S. Typhimurium) live attenuated vaccine carrier strain to prevent enteric infections has been a subject of intensive study. Several mutants of S. Typhimurium have been proposed as an effective live attenuated vaccine strain. Unfortunately, many such mutant strains failed to successfully complete the clinical trials as they were suboptimal in delivering effective safety and immunogenicity. However, it remained unclear, whether the existing live attenuated S. Typhimurium strains can further be attenuated with improved safety and immune efficacy or not. We deleted a specific non-SPI (Salmonella Pathogenicity Island) encoded virulence factor mig-14 (an antimicrobial peptide resistant protein) in ssaV deficient S. Typhimurium strain. The ssaV is an important SPI-II gene involved in Salmonella replication in macrophages and its mutant strain is considered as a potential live attenuated strain. However, fatal systemic infection was previously reported in immunocompromised mice like Nos2-/- and Il-10-/- when infected with ssaV deficient S. Typhimurium. Here we reported that attenuation of S. Typhimurium ssaV mutant in immunocompromised mice can further be improved by introducing additional deletion of gene mig-14. The ssaV, mig-14 double mutant was as efficient as ssaV mutant, with respect to host colonization and eliciting Salmonella-specific mucosal sIgA and serum IgG response in wild-type C57BL/6 mice. Interestingly, this double mutant did not show any systemic infection in immunocompromised mice. This study suggests that ssaV, mig-14 double mutant strain can be effectively used as a potential vaccine candidate even in immunocompromised mice. Such attenuated vaccine strain could possibly used for expression of heterologous antigens and thus for development of a polyvalent vaccine strain.

  8. Mutant models of prolonged life span.

    PubMed

    Mahler, J F

    2001-01-01

    Aging is an important biological process that affects all creatures. For humans, age-related diseases and the question of why we age and die also have tremendous social and philosophical impact. We can therefore expect that models to study mechanisms of the aging process will always attract much interest. Until recently, the mutant model approach to study molecular mechanisms of aging has been limited to lower animals such as yeast, worms, and flies. However, given the current power of genetic technology in mammals, we can expect that phenotypes of prolonged life span will increasingly be seen in mice and subject to evaluation by pathologists. A brief review of current models is presented.

  9. Selective Chemosensitization of Rb Mutant Cells

    DTIC Science & Technology

    2000-07-01

    examined the ability of each E1A mutant to induce p53. Cells expressing full-length E1A dis - played a 20- to 30-fold increase in steady-state p53...retinoblastoma (Rb) protein, and inac- tivation of both is essential for viral transformation (Lane and Crawford 1979; Linzer and Levine 1979; De- Caprio et al...Western blotting. Despite the fact that wild-type MEFs expressing El A dis - played an -10-fold increase in p53 and Mdm2 levels as compared to their Ai?F

  10. Pleiotropic aspartate taxis and serine taxis mutants of Escherichia coli.

    PubMed

    Reader, R W; Tso, W W; Springer, M S; Goy, M F; Adler, J

    1979-04-01

    Mutants that at one time were thought to be specifically defective in taxis toward aspartate and related amino acids (tar mutants) or specifically defective in taxis toward serine and related amino acids (tar mutants) are now shown to be pleiotropic in their defects. The tar mutants also lack taxis toward maltose and away from Co2+ and Ni2+. The tsr mutants are altered in their response to a variety of repellents. Double mutants (tar tsr) fail in nearly all chemotactic responses. The tar and tsr mutants provide evidence for two complementary, converging pathways of information flow: certain chemoreceptors feed information into the tar pathway and others into the tsr pathway. The tar and tsr products have been shown to be two different sets of methylated proteins.

  11. MetQ of Neisseria gonorrhoeae Is a Surface-Expressed Antigen That Elicits Bactericidal and Functional Blocking Antibodies

    PubMed Central

    Semchenko, Evgeny A.; Day, Christopher J.

    2016-01-01

    ABSTRACT Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection (STI) gonorrhea, is a growing public health threat for which a vaccine is urgently needed. We characterized the functional role of the gonococcal MetQ protein, which is the methionine binding component of an ABC transporter system, and assessed its potential as a candidate antigen for inclusion in a gonococcal vaccine. MetQ has been found to be highly conserved in all strains investigated to date, it is localized on the bacterial surface, and it binds l-methionine with a high affinity. MetQ is also involved in gonococcal adherence to cervical epithelial cells. Mutants lacking MetQ have impaired survival in human monocytes, macrophages, and serum. Furthermore, antibodies raised against MetQ are bactericidal and are able to block gonococcal adherence to epithelial cells. These data suggest that MetQ elicits both bactericidal and functional blocking antibodies and is a valid candidate antigen for additional investigation and possible inclusion in a vaccine for prevention of gonorrhea. PMID:27895130

  12. Minocycline inhibits D-amphetamine-elicited action potential bursts in a central snail neuron.

    PubMed

    Chen, Y-H; Lin, P-L; Wong, R-W; Wu, Y-T; Hsu, H-Y; Tsai, M-C; Lin, M-J; Hsu, Y-C; Lin, C-H

    2012-10-25

    Minocycline is a second-generation tetracycline that has been reported to have powerful neuroprotective properties. In our previous studies, we found that d-amphetamine (AMPH) elicited action potential bursts in an identifiable RP4 neuron of the African snail, Achatina fulica Ferussac. This study sought to determine the effects of minocycline on the AMPH-elicited action potential pattern changes in the central snail neuron, using the two-electrode voltage clamping method. Extracellular application of AMPH at 300 μM elicited action potential bursts in the RP4 neuron. Minocycline dose-dependently (300-900 μM) inhibited the action potential bursts elicited by AMPH. The inhibitory effects of minocycline on AMPH-elicited action potential bursts were restored by forskolin (50 μM), an adenylate cyclase activator, and by dibutyryl cAMP (N(6),2'-O-Dibutyryladenosine 3',5'-cyclic monophosphate; 1mM), a membrane-permeable cAMP analog. Co-administration of forskolin (50 μM) plus tetraethylammonium chloride (TEA; 5mM) or co-administration of TEA (5mM) plus dibutyryl cAMP (1mM) also elicited action potential bursts, which were prevented and inhibited by minocycline. In addition, minocycline prevented and inhibited forskolin (100 μM)-elicited action potential bursts. Notably, TEA (50mM)-elicited action potential bursts in the RP4 neuron were not affected by minocycline. Minocycline did not affect steady-state outward currents of the RP4 neuron. However, minocycline did decrease the AMPH-elicited steady-state current changes. Similarly, minocycline decreased the effects of forskolin-elicited steady-state current changes. Pretreatment with H89 (N-[2-(p-Bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride; 10 μM), a protein kinase A inhibitor, inhibited AMPH-elicited action potential bursts and decreased AMPH-elicited steady-state current changes. These results suggest that the cAMP-protein kinase A signaling pathway and the steady-state current are involved in

  13. Protection of rabbits against enteropathogenic Escherichia coli (EPEC) using an intimin null mutant

    PubMed Central

    Stakenborg, Tim; Vandekerchove, Dominique; Mariën, Jonas; Laevens, Hans; Imberechts, Hein; Peeters, Johan

    2006-01-01

    Background Diarrhea and mortality resulting from infections with enteropathogenic Escherichia coli (EPEC) are of major economic importance in the rabbit meat industry. There is a growing need for an effective vaccine to cope with these problems and to reduce the use of antibiotics. EPEC are characterized by an attaching and effacing virulence mechanism. This is partly mediated by the intimate binding between an adhesin, called intimin, and a translocated receptor (Tir) of prokaryote origin. We constructed an intimin deletion mutant of the rabbit EPEC (REPEC) wild-type strain 97/241.6 (bio-/serogroup 3-/O15) and examined its protective capacity. Results After verifying its complete loss of virulence, we used the attenuated strain in vaccination-challenge experiments in which complete protection against a homologous, but virulent, strain was observed. The attenuated strain was able to persist in the intestinal lumen, where it elicited an immune response against EPEC-related virulence proteins, as was shown using an EspB-specific ELISA. Despite the priming of an immune response and the generation of specific antibodies, the intimin mutant was not able to fully protect rabbits against challenges with REPEC strains of other bio-/serogroups. Conclusion These data indicate that protection against REPEC infections is at least partly bio-/serogroup dependent and a multivalent vaccine may be needed for protection against the full range of REPEC types. Such a combination vaccine may be developed using intimin null mutants, as the latter were clearly shown to be safe and effective against homologous infections. PMID:16796739

  14. Retention of Photoinduction of Cytosolic Enzymes in aurea Mutant of Tomato (Lycopersicon esculentum).

    PubMed

    Goud, K. V.; Sharma, R.

    1994-06-01

    The tomato (Lycopersicon esculentum Mill.) aurea (au) mutant has been characterized as a phytochrome-deficient mutant lacking spectrally detectable phytochrome A in etiolated seedlings. Seedlings of au grown under red light (RL) lack phytochrome regulation of nuclear genes encoding plastidic proteins, possess ill-developed chloroplasts, and are slow to de-etiolate. In the present study, the effect of phytochrome deficiency on photoinduction of enzymes in etiolated au seedlings was investigated. The photoinduction of the cytosolic enzymes amylase and nitrate reductase (NR) and of the plastidic enzyme nitrite reductase (NiR) in au was compared with that in the isogenic wild-type (WT) tomato and the high-pigment (hp) mutant with exaggerated phytochrome response. In WT and hp, both brief RL pulses and continuous RL induced amylase, NR, and NiR activities, whereas in au no photoinduction of enzymes was observed with brief RL pulses, and continuous RL induced only amylase and NR activities. The time courses of photoinduction of NR and amylase in au under continuous RL followed patterns qualitatively similar to hp and WT. A blue-light pretreatment prior to continuous RL exposure was ineffective in inducing NiR activity in au. Only continuous white light could elicit a photoinduction of NiR in au seedlings. The norflurazon-triggered loss of photoinduction of NiR in WT and hp indicated that NiR photoinduction depended on chloroplast biogenesis. The results indicate that observed photoinduction of NR and amylase in au may be mediated by a residual phytochrome pool.

  15. Zebrafish Genomic Instability Mutants and Cancer Susceptibility

    PubMed Central

    Moore, Jessica L.; Rush, Lindsay M.; Breneman, Carol; Mohideen, Manzoor-Ali P. K.; Cheng, Keith C.

    2006-01-01

    Somatic loss of tumor suppressor gene function comprising the second hit of Knudson's two-hit hypothesis is important in human cancer. A genetic screen was performed in zebrafish (Danio rerio) to find mutations that cause genomic instability (gin), as scored by Streisinger's mosaic-eye assay that models this second hit. The assay, based on a visible test for loss of wild-type gene function at a single locus, golden, is representative of genomewide events. Twelve ENU-induced genomic instability (gin) mutations were isolated. Most mutations showed weak dominance in heterozygotes and all showed a stronger phenotype in homozygotes. Trans-heterozygosity for 7 of these mutations showed greatly enhanced instability. A variety of spontaneous tumors were found in heterozygous adults from all gin lines, consistent with the expectation that genomic instability (mutator) mutations can accelerate carcinogenesis. The incidence of spontaneous cancer at 30–34 months was increased 9.6-fold in heterozygotes for the mutant with the strongest phenotype, gin-10. Tumors were seen in skin, colon, kidney, liver, pancreas, ovary, testis, and neuronal tissues, with multiple tumors in some fish. The study of these mutants will add to our understanding of the mechanisms of somatic loss of gene function and how those mechanisms contribute to cancer susceptibility. PMID:16888336

  16. Mutants of Arabidopsis thaliana with altered phototropism

    NASA Technical Reports Server (NTRS)

    Khurana, J. P.; Poff, K. L.

    1989-01-01

    Thirty five strains of Arabidopsis thaliana (L.) Heynh. have been identified with altered phototropic responses to 450-nm light. Four of these mutants have been more thoroughly characterized. Strain JK224 shows normal gravitropism and "second positive" phototropism. However, while the amplitude for "first positive" phototropism is the same as that in the wild-type, the threshold and fluence for the maximum response in "first positive" phototropism are shifted to higher fluence by a factor of 20-30. This mutant may represent an alteration in the photoreceptor pigment for phototropism. Strain JK218 exhibits no curvature to light at any fluence from 1 micromole m-2 to 2700 micromoles m-2, but shows normal gravitropism. Strain JK345 shows no "first positive" phototropism, and reduced gravitropism and "second positive" phototropism. Strain JK229 shows no measurable "first positive" phototropism, but normal gravitropism and "second positive" phototropism. Based on these data, it is suggested that: 1. gravitropism and phototropism contain at least one common element; 2. "first positive" and "second positive" phototropism contain at least one common element; and 3. "first positive" phototropism can be substantially altered without any apparent alteration of "second positive" phototropism.

  17. Method for rapid isolation of sensitive mutants

    DOEpatents

    Freyer, James P.

    1997-01-01

    Sensitive mammalian cell mutants are rapidly isolated using flow cytometry. A first population of clonal spheroids is established to contain both normal and mutant cells. The population may be naturally occurring or may arise from mutagenized cells. The first population is then flow sorted by size to obtain a second population of clonal spheroids of a first uniform size. The second population is then exposed to a DNA-damaging agent that is being investigated. The exposed second population is placed in a growth medium to form a third population of clonal spheroids comprising spheroids of increased size from the mammalian cells that are resistant to the DNA-damaging agent and spheroids of substantially the first uniform size formed from the mammalian cells that are sensitive to the DNA-damaging agent. The third population is not flow sorted to differentiate the spheroids formed from resistant mammalian cells from spheroids formed from sensitive mammalian cells. The spheroids formed from sensitive mammalian cells are now treated to recover viable sensitive cells from which a sensitive cell line can be cloned.

  18. Method for rapid isolation of sensitive mutants

    DOEpatents

    Freyer, J.P.

    1997-07-29

    Sensitive mammalian cell mutants are rapidly isolated using flow cytometry. A first population of clonal spheroids is established to contain both normal and mutant cells. The population may be naturally occurring or may arise from mutagenized cells. The first population is then flow sorted by size to obtain a second population of clonal spheroids of a first uniform size. The second population is then exposed to a DNA-damaging agent that is being investigated. The exposed second population is placed in a growth medium to form a third population of clonal spheroids comprising spheroids of increased size from the mammalian cells that are resistant to the DNA-damaging agent and spheroids of substantially the first uniform size formed from the mammalian cells that are sensitive to the DNA-damaging agent. The third population is not flow sorted to differentiate the spheroids formed from resistant mammalian cells from spheroids formed from sensitive mammalian cells. The spheroids formed from sensitive mammalian cells are now treated to recover viable sensitive cells from which a sensitive cell line can be cloned. 15 figs.

  19. Auxin physiology of the tomato mutant diageotropical

    SciTech Connect

    Daniel, S.G.; Rayle, D.L. ); Cleland, R.E. )

    1989-11-01

    The tomato (Lycopersicon esculentum, Mill.) mutant diageotropica (dgt) exhibits biochemical, physiological, and morphological abnormalities that suggest the mutation may have affected a primary site of auxin perception or action. We have compared two aspects of the auxin physiology of dgt and wild-type (VFN8) seedlings: auxin transport and cellular growth parameters. The rates of basipetal indole-3-acetic acid (IAA) polar transport are identical in hypocotyl sections of the two genotypes, but dgt sections have a slightly greater capacity for IAA transport. 2,3,5-Triiodobenzoic acid and ethylene reduce transport in both mutant and wild-type sections. The kinetics of auxin uptake into VFN8 and dgt sections are nearly identical. These results make it unlikely that an altered IAA efflux carrier or IAA uptake symport are responsible for the pleiotropic effects resulting from the dgt mutation. The lack of auxin-induced cell elongation in dgt plants is not due to insufficient turgor, as the osmotic potential of dgt cell sap is less (more negative) than that of VFN8. An auxin-induced increase in wall extensibility, as measured by the Instron technique, only occurs in the VFN8 plants. These data suggest dgt hypocotyls suffer a defect in the sequence of events culminating in auxin-induced cell wall loosening.

  20. Spontaneous Nif- mutants of Rhodopseudomonas capsulata.

    PubMed Central

    Wall, J D; Love, J; Quinn, S P

    1984-01-01

    Revertible, spontaneous Nif- mutants of Rhodopseudomonas capsulata have been shown to accumulate in cultures growing photosynthetically with an amino acid as the nitrogen source such that H2 is maximally produced. The majority of such strains carry mutations which are clustered in a short region of the chromosome, probably representing one or two genes. Because this cluster includes temperature-sensitive mutations, it is also likely that it identifies the structural gene of a polypeptide. The phenotypic characterization of these spontaneous mutants showed (i) an inability to grow with N2 as the nitrogen source, no measurable nitrogenase activity, a reduction or absence of the three polypeptides of the MoFe and Fe proteins of the nitrogenase complex, a faster growth rate on glutamate as the nitrogen source under saturating light, and frequently a small increase in glutamine synthetase activity relative to that of the wild type when grown with glutamate as the nitrogen source. Alterations in other ammonium-assimilatory enzyme activities were not observed. Taken together, these properties suggest that the mutations have affected a regulatory protein necessary for nitrogen fixation. Images PMID:6146598

  1. The LORE1 insertion mutant resource.

    PubMed

    Małolepszy, Anna; Mun, Terry; Sandal, Niels; Gupta, Vikas; Dubin, Manu; Urbański, Dorian; Shah, Niraj; Bachmann, Asger; Fukai, Eigo; Hirakawa, Hideki; Tabata, Satoshi; Nadzieja, Marcin; Markmann, Katharina; Su, Junyi; Umehara, Yosuke; Soyano, Takashi; Miyahara, Akira; Sato, Shusei; Hayashi, Makoto; Stougaard, Jens; Andersen, Stig U

    2016-10-01

    Long terminal repeat (LTR) retrotransposons are closely related to retroviruses, and their activities shape eukaryotic genomes. Here, we present a complete Lotus japonicus insertion mutant collection generated by identification of 640 653 new insertion events following de novo activation of the LTR element Lotus retrotransposon 1 (LORE1) (http://lotus.au.dk). Insertion preferences are critical for effective gene targeting, and we exploit our large dataset to analyse LTR element characteristics in this context. We infer the mechanism that generates the consensus palindromes typical of retroviral and LTR retrotransposon insertion sites, identify a short relaxed insertion site motif, and demonstrate selective integration into CHG-hypomethylated genes. These characteristics result in a steep increase in deleterious mutation rate following activation, and allow LORE1 active gene targeting to approach saturation within a population of 134 682 L. japonicus lines. We suggest that saturation mutagenesis using endogenous LTR retrotransposons with germinal activity can be used as a general and cost-efficient strategy for generation of non-transgenic mutant collections for unrestricted use in plant research.

  2. Auxin physiology of the tomato mutant diageotropica

    NASA Technical Reports Server (NTRS)

    Daniel, S. G.; Rayle, D. L.; Cleland, R. E.

    1989-01-01

    The tomato (Lycopersicon esculentum, Mill.) mutant diageotropica (dgt) exhibits biochemical, physiological, and morphological abnormalities that suggest the mutation may have affected a primary site of auxin perception or action. We have compared two aspects of the auxin physiology of dgt and wild-type (VFN8) seedlings: auxin transport and cellular growth parameters. The rates of basipetal indole-3-acetic acid (IAA) polar transport are identical in hypocotyl sections of the two genotypes, but dgt sections have a slightly greater capacity for IAA transport. 2,3,5-Triiodobenzoic acid and ethylene reduce transport in both mutant and wild-type sections. The kinetics of auxin uptake into VFN8 and dgt sections are nearly identical. These results make it unlikely that an altered IAA efflux carrier or IAA uptake symport are responsible for the pleiotropic effects resulting from the dgt mutation. The lack of auxin-induced cell elongation in dgt plants is not due to insufficient turgor, as the osmotic potential of dgt cell sap is less (more negative) than that of VFN8. An auxin-induced increase in wall extensibility, as measured by the Instron technique, only occurs in the VFN8 plants. These data suggest dgt hypocotyls suffer a defect in the sequence of events culminating in auxin-induced cell wall loosening.

  3. Mutants of Arabidopsis thaliana with altered phototropism

    NASA Technical Reports Server (NTRS)

    Khurana, J. P.; Poff, K. L.

    1989-01-01

    Thirty five strains of Arabidopsis thaliana (L.) Heynh. have been identified with altered phototropic responses to 450-nm light. Four of these mutants have been more thoroughly characterized. Strain JK224 shows normal gravitropism and "second positive" phototropism. However, while the amplitude for "first positive" phototropism is the same as that in the wild-type, the threshold and fluence for the maximum response in "first positive" phototropism are shifted to higher fluence by a factor of 20-30. This mutant may represent an alteration in the photoreceptor pigment for phototropism. Strain JK218 exhibits no curvature to light at any fluence from 1 micromole m-2 to 2700 micromoles m-2, but shows normal gravitropism. Strain JK345 shows no "first positive" phototropism, and reduced gravitropism and "second positive" phototropism. Strain JK229 shows no measurable "first positive" phototropism, but normal gravitropism and "second positive" phototropism. Based on these data, it is suggested that: 1. gravitropism and phototropism contain at least one common element; 2. "first positive" and "second positive" phototropism contain at least one common element; and 3. "first positive" phototropism can be substantially altered without any apparent alteration of "second positive" phototropism.

  4. Auxin physiology of the tomato mutant diageotropica

    NASA Technical Reports Server (NTRS)

    Daniel, S. G.; Rayle, D. L.; Cleland, R. E.

    1989-01-01

    The tomato (Lycopersicon esculentum, Mill.) mutant diageotropica (dgt) exhibits biochemical, physiological, and morphological abnormalities that suggest the mutation may have affected a primary site of auxin perception or action. We have compared two aspects of the auxin physiology of dgt and wild-type (VFN8) seedlings: auxin transport and cellular growth parameters. The rates of basipetal indole-3-acetic acid (IAA) polar transport are identical in hypocotyl sections of the two genotypes, but dgt sections have a slightly greater capacity for IAA transport. 2,3,5-Triiodobenzoic acid and ethylene reduce transport in both mutant and wild-type sections. The kinetics of auxin uptake into VFN8 and dgt sections are nearly identical. These results make it unlikely that an altered IAA efflux carrier or IAA uptake symport are responsible for the pleiotropic effects resulting from the dgt mutation. The lack of auxin-induced cell elongation in dgt plants is not due to insufficient turgor, as the osmotic potential of dgt cell sap is less (more negative) than that of VFN8. An auxin-induced increase in wall extensibility, as measured by the Instron technique, only occurs in the VFN8 plants. These data suggest dgt hypocotyls suffer a defect in the sequence of events culminating in auxin-induced cell wall loosening.

  5. Too Many Mutants with Multiple Mutations

    PubMed Central

    Drake, John W.

    2007-01-01

    It has recently become clear that the classical notion of the random nature of mutation does not hold for the distribution of mutations among genes: most collections of mutants contain more isolates with two or more mutations than predicted by the mutant frequency on the assumption of a random distribution of mutations. Excesses of multiples are seen in a wide range of organisms, including riboviruses, DNA viruses, prokaryotes, yeasts, and higher eukaryotic cell lines and tissues. In addition, such excesses are produced by DNA polymerases in vitro. These “multiples” appear to be generated by transient, localized hypermutation rather than by heritable mutator mutations. The components of multiples are sometimes scattered at random and sometimes display an excess of smaller distances between mutations. As yet, almost nothing is known about the mechanisms that generate multiples, but such mutations have the capacity to accelerate those evolutionary pathways that require multiple mutations where the individual mutations are neutral or deleterious. Examples that impinge on human health may include carcinogenesis and the adaptation of microbial pathogens as they move between individual hosts. PMID:17687667

  6. Effects of mutant rat dynamin on endocytosis

    PubMed Central

    1993-01-01

    Dynamin is a 100-kD microtubule-activated GTPase. Recent evidence has revealed a high degree of sequence homology with the product of the Drosophila gene shibire, mutations in which block the recycling of synaptic vesicles and, more generally, the formation of coated and non- coated vesicles at the plasma membrane. We have now transfected cultured mammalian COS-7 cells with both wild-type and mutant dynamin cDNAs. Point mutations in the GTP-binding consensus sequence elements of dynamin equivalent to dominant negative mutations in ras, and an NH2- terminal deletion of the entire GTP-binding domain of dynamin, block transferrin uptake and alter the distribution of clathrin heavy chain and alpha-, but not gamma-, adaptin. COOH-terminal deletions reverse these effects, identifying this portion of dynamin as a site of interaction with other components of the endocytic pathway. Over- expression of neither wild-type nor mutant forms of dynamin affected the distribution of microtubules. These results demonstrate a specific role for dynamin and for GTP in the initial stages of receptor-mediated endocytosis. PMID:8335685

  7. Thiostrepton-resistant mutants of Thermus thermophilus

    PubMed Central

    Cameron, Dale M.; Thompson, Jill; Gregory, Steven T.; March, Paul E.; Dahlberg, Albert E.

    2004-01-01

    Ribosomal protein L11 and its associated binding site on 23S rRNA together comprise one of the principle components that mediate interactions of translation factors with the ribosome. This site is also the target of the antibiotic thiostrepton, which has been proposed to act by preventing important structural transitions that occur in this region of the ribosome during protein synthesis. Here, we describe the isolation and characterization of spontaneous thiostrepton-resistant mutants of the extreme thermophile, Thermus thermophilus. All mutations were found at conserved positions in the flexible N-terminal domain of L11 or at conserved positions in the L11-binding site of 23S rRNA. A number of the mutant ribosomes were affected in in vitro EF-G-dependent GTP hydrolysis but all showed resistance to thiostrepton at levels ranging from high to moderate. Structure probing revealed that some of the mutations in L11 result in enhanced reactivity of adjacent rRNA bases to chemical probes, suggesting a more open conformation of this region. These data suggest that increased flexibility of the factor binding site results in resistance to thiostrepton by counteracting the conformation-stabilizing effect of the antibiotic. PMID:15199170

  8. Too many mutants with multiple mutations.

    PubMed

    Drake, John W

    2007-01-01

    It has recently become clear that the classical notion of the random nature of mutation does not hold for the distribution of mutations among genes: most collections of mutants contain more isolates with two or more mutations than predicted by the mutant frequency on the assumption of a random distribution of mutations. Excesses of multiples are seen in a wide range of organisms, including riboviruses, DNA viruses, prokaryotes, yeasts, and higher eukaryotic cell lines and tissues. In addition, such excesses are produced by DNA polymerases in vitro. These "multiples" appear to be generated by transient, localized hypermutation rather than by heritable mutator mutations. The components of multiples are sometimes scattered at random and sometimes display an excess of smaller distances between mutations. As yet, almost nothing is known about the mechanisms that generate multiples, but such mutations have the capacity to accelerate those evolutionary pathways that require multiple mutations where the individual mutations are neutral or deleterious. Examples that impinge on human health may include carcinogenesis and the adaptation of microbial pathogens as they move between individual hosts.

  9. Plant Innate Immunity Induced by Flagellin Suppresses the Hypersensitive Response in Non-Host Plants Elicited by Pseudomonas syringae pv. averrhoi

    PubMed Central

    Wei, Chia-Fong; Hsu, Shih-Tien; Deng, Wen-Ling; Wen, Yu-Der; Huang, Hsiou-Chen

    2012-01-01

    A new pathogen, Pseudomonas syringae pv. averrhoi (Pav), which causes bacterial spot disease on carambola was identified in Taiwan in 1997. Many strains of this pathovar have been isolated from different locations and several varieties of hosts. Some of these strains, such as HL1, are nonmotile and elicit a strong hypersensitive response (HR) in nonhost tobacco leaves, while other strains, such as PA5, are motile and elicit a weak HR. Based on the image from a transmission electron microscope, the results showed that HL1 is flagellum-deficient and PA5 has normal flagella. Here we cloned and analyzed the fliC gene and glycosylation island from Pav HL1 and PA5. The amino acid sequences of FliC from HL1 and PA5 are identical to P. s. pvs. tabaci (Pta), glycinea and phaseolicola and share very high similarity with other pathovars of P. syringae. In contrast to the flagellin mutant PtaΔfliC, PA5ΔfliC grows as well as wild type in the host plant, but it elicits stronger HR than wild type does in non-host plants. Furthermore, the purified Pav flagellin, but not the divergent flagellin from Agrobacterium tumefaciens, is able to impair the HR induced by PA5ΔfliC. PA5Δfgt1 possessing nonglycosylated flagella behaved as its wild type in both bacterial growth in host and HR elicitation. Flagellin was infiltrated into tobacco leaves either simultaneously with flagellum-deficient HL1 or prior to the inoculation of wild type HL1, and both treatments impaired the HR induced by HL1. Moreover, the HR elicited by PA5 and PA5ΔfliC was enhanced by the addition of cycloheximide, suggesting that the flagellin is one of the PAMPs (pathogen-associated molecular patterns) contributed to induce the PAMP-triggered immunity (PTI). Taken together, the results shown in this study reveal that flagellin in Pav is capable of suppressing HR via PTI induction during an incompatible interaction. PMID:22911741

  10. Plant innate immunity induced by flagellin suppresses the hypersensitive response in non-host plants elicited by Pseudomonas syringae pv. averrhoi.

    PubMed

    Wei, Chia-Fong; Hsu, Shih-Tien; Deng, Wen-Ling; Wen, Yu-Der; Huang, Hsiou-Chen

    2012-01-01

    A new pathogen, Pseudomonas syringae pv. averrhoi (Pav), which causes bacterial spot disease on carambola was identified in Taiwan in 1997. Many strains of this pathovar have been isolated from different locations and several varieties of hosts. Some of these strains, such as HL1, are nonmotile and elicit a strong hypersensitive response (HR) in nonhost tobacco leaves, while other strains, such as PA5, are motile and elicit a weak HR. Based on the image from a transmission electron microscope, the results showed that HL1 is flagellum-deficient and PA5 has normal flagella. Here we cloned and analyzed the fliC gene and glycosylation island from Pav HL1 and PA5. The amino acid sequences of FliC from HL1 and PA5 are identical to P. s. pvs. tabaci (Pta), glycinea and phaseolicola and share very high similarity with other pathovars of P. syringae. In contrast to the flagellin mutant PtaΔfliC, PA5ΔfliC grows as well as wild type in the host plant, but it elicits stronger HR than wild type does in non-host plants. Furthermore, the purified Pav flagellin, but not the divergent flagellin from Agrobacterium tumefaciens, is able to impair the HR induced by PA5ΔfliC. PA5Δfgt1 possessing nonglycosylated flagella behaved as its wild type in both bacterial growth in host and HR elicitation. Flagellin was infiltrated into tobacco leaves either simultaneously with flagellum-deficient HL1 or prior to the inoculation of wild type HL1, and both treatments impaired the HR induced by HL1. Moreover, the HR elicited by PA5 and PA5ΔfliC was enhanced by the addition of cycloheximide, suggesting that the flagellin is one of the PAMPs (pathogen-associated molecular patterns) contributed to induce the PAMP-triggered immunity (PTI). Taken together, the results shown in this study reveal that flagellin in Pav is capable of suppressing HR via PTI induction during an incompatible interaction.

  11. Video Elicitation Interviews: A Qualitative Research Method for Investigating Physician-Patient Interactions

    PubMed Central

    Henry, Stephen G.; Fetters, Michael D.

    2012-01-01

    We describe the concept and method of video elicitation interviews and provide practical guidance for primary care researchers who want to use this qualitative method to investigate physician-patient interactions. During video elicitation interviews, researchers interview patients or physicians about a recent clinical interaction using a video recording of that interaction as an elicitation tool. Video elicitation is useful because it allows researchers to integrate data about the content of physician-patient interactions gained from video recordings with data about participants’ associated thoughts, beliefs, and emotions gained from elicitation interviews. This method also facilitates investigation of specific events or moments during interactions. Video elicitation interviews are logistically demanding and time consuming, and they should be reserved for research questions that cannot be fully addressed using either standard interviews or video recordings in isolation. As many components of primary care fall into this category, high-quality video elicitation interviews can be an important method for understanding and improving physician-patient interactions in primary care. PMID:22412003

  12. Video elicitation interviews: a qualitative research method for investigating physician-patient interactions.

    PubMed

    Henry, Stephen G; Fetters, Michael D

    2012-01-01

    We describe the concept and method of video elicitation interviews and provide practical guidance for primary care researchers who want to use this qualitative method to investigate physician-patient interactions. During video elicitation interviews, researchers interview patients or physicians about a recent clinical interaction using a video recording of that interaction as an elicitation tool. Video elicitation is useful because it allows researchers to integrate data about the content of physician-patient interactions gained from video recordings with data about participants' associated thoughts, beliefs, and emotions gained from elicitation interviews. This method also facilitates investigation of specific events or moments during interactions. Video elicitation interviews are logistically demanding and time consuming, and they should be reserved for research questions that cannot be fully addressed using either standard interviews or video recordings in isolation. As many components of primary care fall into this category, high-quality video elicitation interviews can be an important method for understanding and improving physician-patient interactions in primary care.

  13. Salmonella typhimurium Mutants Lacking Ribonuclease I: Effect on the Polarity of Histidine Mutants

    PubMed Central

    Bruni, Carmelo B.; Rechler, Matthew M.; Martin, Robert G.

    1973-01-01

    Mutants of Salmonella typhimurium containing 1 to 2% of wild-type ribonuclease I activity were isolated. The rns mutation had no effect on the polarity of mutations in the S. typhimurium histidine operon. Even in the presence of an rns mutation, it was not possible to obtain strong suppressors of the polarity of two polar mutations in the his operon. PMID:4347966

  14. Mutants of Saccharomyces cerevisiae with defects in acetate metabolism: isolation and characterization of Acn- mutants.

    PubMed

    McCammon, M T

    1996-09-01

    The two carbon compounds, ethanol and acetate, can be oxidatively metabolized as well as assimilated into carbohydrate in the yeast Saccharomyces cerevisiae. The distribution of acetate metabolic enzymes among several cellular compartments, mitochondria, peroxisomes, and cytoplasm makes it an intriguing system to study complex metabolic interactions. To investigate the complex process of carbon catabolism and assimilation, mutants unable to grow on acetate were isolated. One hundred five Acn- ("ACetate Nonutilizing") mutants were sorted into 21 complementation groups with an additional 20 single mutants. Five of the groups have defects in TCA cycle enzymes: MDH1, CIT1, ACO1, IDH1, and IDH2. A defect in RTG2, involved in the retrograde communication between the mitochondrion and the nucleus, was also identified. Four genes encode enzymes of the glyoxylate cycle and gluconeogenesis: ICL1, MLS1, MDH2, and PCK1. Five other genes appear to be defective in regulating metabolic activity since elevated levels of enzymes in several metabolic pathways, including the glyoxylate cycle, gluconeogenesis, and acetyl-CoA metabolism, were detected in these mutants: ACN8, ACN9, ACN17, ACN18, and ACN42. In summary, this analysis has identified at least 22 and as many as 41 different genes involved in acetate metabolism.

  15. Mutants of Saccharomyces Cerevisiae with Defects in Acetate Metabolism: Isolation and Characterization of Acn(-) Mutants

    PubMed Central

    McCammon, M. T.

    1996-01-01

    The two carbon compounds, ethanol and acetate, can be oxidatively metabolized as well as assimilated into carbohydrate in the yeast Saccharomyces cerevisiae. The distribution of acetate metabolic enzymes among several cellular compartments, mitochondria, peroxisomes, and cytoplasm makes it an intriguing system to study complex metabolic interactions. To investigate the complex process of carbon catabolism and assimilation, mutants unable to grow on acetate were isolated. One hundred five Acn(-) (``ACetate Nonutilizing'') mutants were sorted into 21 complementation groups with an additional 20 single mutants. Five of the groups have defects in TCA cycle enzymes: MDH1, CIT1, ACO1, IDH1, and IDH2. A defect in RTG2, involved in the retrograde communication between the mitochondrion and the nucleus, was also identified. Four genes encode enzymes of the glyoxylate cycle and gluconeogenesis: ICL1, MLS1, MDH2, and PCK1. Five other genes appear to be defective in regulating metabolic activity since elevated levels of enzymes in several metabolic pathways, including the glyoxylate cycle, gluconeogenesis, and acetyl-CoA metabolism, were detected in these mutants: ACN8, ACN9, ACN17, ACN18, and ACN42. In summary, this analysis has identified at least 22 and as many as 41 different genes involved in acetate metabolism. PMID:8878673

  16. Allosteric Mutant IDH1 Inhibitors Reveal Mechanisms for IDH1 Mutant and Isoform Selectivity.

    PubMed

    Xie, Xiaoling; Baird, Daniel; Bowen, Kimberly; Capka, Vladimir; Chen, Jinyun; Chenail, Gregg; Cho, YoungShin; Dooley, Julia; Farsidjani, Ali; Fortin, Pascal; Kohls, Darcy; Kulathila, Raviraj; Lin, Fallon; McKay, Daniel; Rodrigues, Lindsey; Sage, David; Touré, B Barry; van der Plas, Simon; Wright, Kirk; Xu, Ming; Yin, Hong; Levell, Julian; Pagliarini, Raymond A

    2017-03-07

    Oncogenic IDH1 and IDH2 mutations contribute to cancer via production of R-2-hydroxyglutarate (2-HG). Here, we characterize two structurally distinct mutant- and isoform-selective IDH1 inhibitors that inhibit 2-HG production. Both bind to an allosteric pocket on IDH1, yet shape it differently, highlighting the plasticity of this site. Oncogenic IDH1(R132H) mutation destabilizes an IDH1 "regulatory segment," which otherwise restricts compound access to the allosteric pocket. Regulatory segment destabilization in wild-type IDH1 promotes inhibitor binding, suggesting that destabilization is critical for mutant selectivity. We also report crystal structures of oncogenic IDH2 mutant isoforms, highlighting the fact that the analogous segment of IDH2 is not similarly destabilized. This intrinsic stability of IDH2 may contribute to observed inhibitor IDH1 isoform selectivity. Moreover, discrete residues in the IDH1 allosteric pocket that differ from IDH2 may also guide IDH1 isoform selectivity. These data provide a deeper understanding of how IDH1 inhibitors achieve mutant and isoform selectivity.

  17. Sim2 Mutants Have Developmental Defects Not Overlapping with Those of Sim1 Mutants

    PubMed Central

    Goshu, Eleni; Jin, Hui; Fasnacht, Rachel; Sepenski, Mike; Michaud, Jacques L.; Fan, Chen-Ming

    2002-01-01

    The mouse genome contains two Sim genes, Sim1 and Sim2. They are presumed to be important for central nervous system (CNS) development because they are homologous to the Drosophila single-minded (sim) gene, mutations in which cause a complete loss of CNS midline cells. In the mammalian CNS, Sim2 and Sim1 are coexpressed in the paraventricular nucleus (PVN). While Sim1 is essential for the development of the PVN (J. L. Michaud, T. Rosenquist, N. R. May, and C.-M. Fan, Genes Dev. 12:3264-3275, 1998), we report here that Sim2 mutant has a normal PVN. Analyses of the Sim1 and Sim2 compound mutants did not reveal obvious genetic interaction between them in PVN histogenesis. However, Sim2 mutant mice die within 3 days of birth due to lung atelectasis and breathing failure. We attribute the diminished efficacy of lung inflation to the compromised structural components surrounding the pleural cavity, which include rib protrusions, abnormal intercostal muscle attachments, diaphragm hypoplasia, and pleural mesothelium tearing. Although each of these structures is minimally affected, we propose that their combined effects lead to the mechanical failure of lung inflation and death. Sim2 mutants also develop congenital scoliosis, reflected by the unequal sizes of the left and right vertebrae and ribs. The temporal and spatial expression patterns of Sim2 in these skeletal elements suggest that Sim2 regulates their growth and/or integrity. PMID:12024028

  18. Sub-lethal levels of electric current elicit the biosynthesis of plant secondary metabolites.

    PubMed

    Kaimoyo, Evans; Farag, Mohamed A; Sumner, Lloyd W; Wasmann, Catherine; Cuello, Joel L; VanEtten, Hans

    2008-01-01

    Many secondary metabolites that are normally undetectable or in low amounts in healthy plant tissue are synthesized in high amounts in response to microbial infection. Various abiotic and biotic agents have been shown to mimic microorganisms and act as elicitors of the synthesis of these plant compounds. In the present study, sub-lethal levels of electric current are shown to elicit the biosynthesis of secondary metabolites in transgenic and non-transgenic plant tissue. The production of the phytoalexin (+)-pisatin by pea was used as the main model system. Non-transgenic pea hairy roots treated with 30-100 mA of electric current produced 13 times higher amounts of (+)-pisatin than did the non-elicited controls. Electrically elicited transgenic pea hairy root cultures blocked at various enzymatic steps in the (+)-pisatin biosynthetic pathway also accumulated intermediates preceding the blocked enzymatic step. Secondary metabolites not usually produced by pea accumulated in some of the transgenic root cultures after electric elicitation due to the diversion of the intermediates into new pathways. The amount of pisatin in the medium bathing the roots of electro-elicited roots of hydroponically cultivated pea plants was 10 times higher 24 h after elicitation than in the medium surrounding the roots of non-elicited control plants, showing not only that the electric current elicited (+)-pisatin biosynthesis but also that the (+)-pisatin was released from the roots. Seedlings, intact roots or cell suspension cultures of fenugreek (Trigonella foenum-graecum), barrel medic, (Medicago truncatula), Arabidopsis thaliana, red clover (Trifolium pratense) and chickpea (Cicer arietinum) also produced increased levels of secondary metabolites in response to electro-elicitation. On the basis of our results, electric current would appear to be a general elicitor of plant secondary metabolites and to have potential for application in both basic and commercial research.

  19. Defective Kernel Mutants of Maize. I. Genetic and Lethality Studies

    PubMed Central

    Neuffer, M. G.; Sheridan, William F.

    1980-01-01

    A planting of 3,919 M1 kernels from normal ears crossed by EMS-treated pollen produced 3,461 M1 plants and 3,172 selfed ears. These plants yielded 2,477 (72%) total heritable changes; the selfed ears yielded 2,457 (78%) recessive mutants, including 855 (27%) recessive kernel mutants and 8 (0.23%) viable dominant mutants. The ratio of recessive to dominant mutants was 201:1. The average mutation frequency for four known loci was three per 3,172 genomes analyzed. The estimated total number of loci mutated was 535 and the estimated number of kernel mutant loci mutated was 285. Among the 855 kernel mutants, 432 had a nonviable embryo, and 59 germinated but had a lethal seedling. A sample of 194 of the latter two types was tested for heritability, lethality, chromosome arm location and endosperm-embryo interaction between mutant and nonmutant tissues in special hyper-hypoploid combinations produced by manipulation of B-A translocations. The selected 194 mutants were characterized and catalogued according to endosperm phenotype and investigated to determine their effects on the morphology and development of the associated embryo. The possibility of rescuing some of the lethal mutants by covering the mutant embryo with a normal endosperm was investigated. Ninety of these 194 mutants were located on 17 of the 18 chromosome arms tested. Nineteen of the located mutants were examined to determine the effect of having a normal embryo in the same kernel with a mutant endosperm, and vice versa, as compared to the expression observed in kernels with both embryo and endosperm in a mutant condition. In the first situation, for three of the 19 mutants, the mutant endosperm was less extreme (the embryo helped); for seven cases, the mutant endosperm was more extreme (the embryo hindered); and for nine cases, there was no change. In the reverse situation, for four cases the normal endosperm helped the mutant embryo; for 14 cases there was no change and one case was inconclusive. PMID

  20. Defective kernel mutants of maize. I. Genetic and lethality studies.

    PubMed

    Neuffer, M G; Sheridan, W F

    1980-08-01

    A planting of 3,919 M(1) kernels from normal ears crossed by EMS-treated pollen produced 3,461 M(1) plants and 3,172 selfed ears. These plants yielded 2,477 (72%) total heritable changes; the selfed ears yielded 2,457 (78%) recessive mutants, including 855 (27%) recessive kernel mutants and 8 (0.23%) viable dominant mutants. The ratio of recessive to dominant mutants was 201:1. The average mutation frequency for four known loci was three per 3,172 genomes analyzed. The estimated total number of loci mutated was 535 and the estimated number of kernel mutant loci mutated was 285. Among the 855 kernel mutants, 432 had a nonviable embryo, and 59 germinated but had a lethal seedling. A sample of 194 of the latter two types was tested for heritability, lethality, chromosome arm location and endosperm-embryo interaction between mutant and nonmutant tissues in special hyper-hypoploid combinations produced by manipulation of B-A translocations. The selected 194 mutants were characterized and catalogued according to endosperm phenotype and investigated to determine their effects on the morphology and development of the associated embryo. The possibility of rescuing some of the lethal mutants by covering the mutant embryo with a normal endosperm was investigated. Ninety of these 194 mutants were located on 17 of the 18 chromosome arms tested. Nineteen of the located mutants were examined to determine the effect of having a normal embryo in the same kernel with a mutant endosperm, and vice versa, as compared to the expression observed in kernels with both embryo and endosperm in a mutant condition. In the first situation, for three of the 19 mutants, the mutant endosperm was less extreme (the embryo helped); for seven cases, the mutant endosperm was more extreme (the embryo hindered); and for nine cases, there was no change. In the reverse situation, for four cases the normal endosperm helped the mutant embryo; for 14 cases there was no change and one case was inconclusive.

  1. Mutants of downy mildew resistance in Lactuca sativa (lettuce).

    PubMed

    Okubara, P A; Anderson, P A; Ochoa, O E; Michelmore, R W

    1994-07-01

    As part of our investigation of disease resistance in lettuce, we generated mutants that have lost resistance to Bremia lactucae, the casual fungus of downy mildew. Using a rapid and reliable screen, we identified 16 distinct mutants of Latuca sativa that have lost activity of one of four different downy mildew resistance genes (Dm). In all mutants, only a single Dm specificity was affected. Genetic analysis indicated that the lesions segregated as single, recessive mutations at the Dm loci. Dm3 was inactivated in nine of the mutants. One of five Dm 1 mutants was selected from a population of untreated seeds and therefore carried a spontaneous mutation. All other Dm1, Dm3, Dm5/8 and Dm7 mutants were derived from gamma- or fast neutron-irradiated seed. In two separate Dm 1 mutants and in each of the eight Dm3 mutants analyzed, at least one closely linked molecular marker was absent. Also, high molecular weight genomic DNA fragments that hybridized to a tightly linked molecular marker in wild type were either missing entirely or were truncated in two of the Dm3 mutants, providing additional evidence that deletions had occurred in these mutants. Absence of mutations at loci epistatic to the Dm genes suggested that such loci were either members of multigene families, were critical for plant survival, or encoded components of duplicated pathways for resistance; alternatively, the genes determining downy mildew resistance might be limited to the Dm loci.

  2. Mutants of Downy Mildew Resistance in Lactuca Sativa (Lettuce)

    PubMed Central

    Okubara, P. A.; Anderson, P. A.; Ochoa, O. E.; Michelmore, R. W.

    1994-01-01

    As part of our investigation of disease resistance in lettuce, we generated mutants that have lost resistance to Bremia lactucae, the casual fungus of downy mildew. Using a rapid and reliable screen, we identified 16 distinct mutants of Latuca sativa that have lost activity of one of four different downy mildew resistance genes (Dm). In all mutants, only a single Dm specificity was affected. Genetic analysis indicated that the lesions segregated as single, recessive mutations at the Dm loci. Dm3 was inactivated in nine of the mutants. One of five Dm1 mutants was selected from a population of untreated seeds and therefore carried a spontaneous mutation. All other Dm1, Dm3, Dm5/8 and Dm7 mutants were derived from γ- or fast neutron-irradiated seed. In two separate Dm1 mutants and in each of the eight Dm3 mutants analyzed, at least one closely linked molecular marker was absent. Also, high molecular weight genomic DNA fragments that hybridized to a tightly linked molecular marker in wild type were either missing entirely or were truncated in two of the Dm3 mutants, providing additional evidence that deletions had occurred in these mutants. Absence of mutations at loci epistatic to the Dm genes suggested that such loci were either members of multigene families, were critical for plant survival, or encoded components of duplicated pathways for resistance; alternatively, the genes determining downy mildew resistance might be limited to the Dm loci. PMID:8088530

  3. Forward genetic screen for auxin-deficient mutants by cytokinin.

    PubMed

    Wu, Lei; Luo, Pan; Di, Dong-Wei; Wang, Li; Wang, Ming; Lu, Cheng-Kai; Wei, Shao-Dong; Zhang, Li; Zhang, Tian-Zi; Amakorová, Petra; Strnad, Miroslav; Novák, Ondřej; Guo, Guang-Qin

    2015-07-06

    Identification of mutants with impairments in auxin biosynthesis and dynamics by forward genetic screening is hindered by the complexity, redundancy and necessity of the pathways involved. Furthermore, although a few auxin-deficient mutants have been recently identified by screening for altered responses to shade, ethylene, N-1-naphthylphthalamic acid (NPA) or cytokinin (CK), there is still a lack of robust markers for systematically isolating such mutants. We hypothesized that a potentially suitable phenotypic marker is root curling induced by CK, as observed in the auxin biosynthesis mutant CK-induced root curling 1 / tryptophan aminotransferase of Arabidopsis 1 (ckrc1/taa1). Phenotypic observations, genetic analyses and biochemical complementation tests of Arabidopsis seedlings displaying the trait in large-scale genetic screens showed that it can facilitate isolation of mutants with perturbations in auxin biosynthesis, transport and signaling. However, unlike transport/signaling mutants, the curled (or wavy) root phenotypes of auxin-deficient mutants were significantly induced by CKs and could be rescued by exogenous auxins. Mutants allelic to several known auxin biosynthesis mutants were re-isolated, but several new classes of auxin-deficient mutants were also isolated. The findings show that CK-induced root curling provides an effective marker for discovering genes involved in auxin biosynthesis or homeostasis.

  4. Neurobehavioral Mutants Identified in an ENU Mutagenesis Project

    SciTech Connect

    Cook, Melloni N.; Dunning, Jonathan P; Wiley, Ronald G; Chesler, Elissa J; Johnson, Dabney K; Goldowitz, Daniel

    2007-01-01

    We report on a behavioral screening test battery that successfully identified several neurobehavioral mutants among a large-scale ENU-mutagenized mouse population. Large numbers of ENU mutagenized mice were screened for abnormalities in central nervous system function based on abnormal performance in a series of behavior tasks. We developed and employed a high-throughput screen of behavioral tasks to detect behavioral outliers. Twelve mutant pedigrees, representing a broad range of behavioral phenotypes, have been identified. Specifically, we have identified two open field mutants (one displaying hyper-locomotion, the other hypo-locomotion), four tail suspension mutants (all displaying increased immobility), one nociception mutant (displaying abnormal responsiveness to thermal pain), two prepulse inhibition mutants (displaying poor inhibition of the startle response), one anxiety-related mutant (displaying decreased anxiety in the light/dark test), and one learning and memory mutant (displaying reduced response to the conditioned stimulus) These findings highlight the utility of a set of behavioral tasks used in a high throughput screen to identify neurobehavioral mutants. Further analysis (i.e., behavioral and genetic mapping studies) of mutants is in progress with the ultimate goal of identification of novel genes and mouse models relevant to human disorders as well as the identification of novel therapeutic targets.

  5. Elicitation of anti-viral cytotoxic T lymphocytes with purified viral and H-2 antigens.

    PubMed

    Hale, A H; Ruebush, M J; Harris, D T

    1980-07-01

    The minimal molecular requirements for elicitation of secondary anti-Sendai virus CTL were investigated. The hemagglutinin-neuraminidase (HN) glycoprotein of Sendai virus and the H-2Kk glycoprotein of YAC tumor cells were purified and incorporated into phospholipid vesicles. These unilamellar liposomes were then tested for the ability to elicit H-2 restricted secondary anti-Sendai virus CTL. The results indicate that these well-defined vesicles were capable of eliciting secondary anti-Sendai virus CTL which lysed only target cells possessing the H-2Kk haplotype and modified with inactivated Sendai virus.

  6. The AvrB_AvrC domain of AvrXccC of Xanthomonas campestris pv. campestris is required to elicit plant defense responses and manipulate ABA homeostasis.

    PubMed

    Ho, Yi-Ping; Tan, Choon Meng; Li, Meng-Ying; Lin, Hong; Deng, Wen-Ling; Yang, Jun-Yi

    2013-04-01

    Plant disease induced by Xanthomonas campestris pv. campestris depends on type III effectors but the molecular basis is poorly understood. Here, AvrXccC8004 was characterized, and it was found that the AvrB_AvrC domain was essential and sufficient to elicit defense responses in an Arabidopsis-resistant ecotype (Col-0). An upregulation of genes in responding to the AvrB_AvrC domain of AvrXccC8004 was shown in a profile of host gene expression. The molecular changes were correlated with morphological changes observed in phenotypic and ultrastructural characterizations. Interestingly, the abscisic acid (ABA)-signaling pathway was also a prominent target for the AvrB_AvrC domain of AvrXccC8004. The highly elicited NCED5, encoding a key enzyme of ABA biosynthesis, was increased in parallel with ABA levels in AvrXccC8004 transgenic plants. Consistently, the X. campestris pv. campestris 8004 ΔavrXccC mutant was severely impaired in the ability to manipulate the accumulation of ABA and induction of ABA-related genes in challenged leaves. Moreover, exogenous application of ABA also enhanced the susceptibility of Arabidopsis to the X. campestris pv. campestris strains. These results indicate that the AvrB_AvrC domain of AvrXccC8004 alone has the activity to manipulate ABA homeostasis, which plays an important role in regulating the interactions of X. campestris pv. campestris and Arabidopsis.

  7. Hoxc13 mutant mice lack external hair.

    PubMed

    Godwin, A R; Capecchi, M R

    1998-01-01

    Hox genes are usually expressed temporally and spatially in a colinear manner with respect to their positions in the Hox complex. Consistent with the expected pattern for a paralogous group 13 member, early embryonic Hoxc13 expression is found in the nails and tail. Hoxc13 is also expressed in vibrissae, in the filiform papillae of the tongue, and in hair follicles throughout the body; a pattern that apparently violates spatial colinearity. Mice carrying mutant alleles of Hoxc13 have been generated by gene targeting. Homozygotes have defects in every region in which gene expression is seen. The most striking defect is brittle hair resulting in alopecia (hairless mice). One explanation for this novel role is that Hoxc13 has been recruited for a function common to hair, nail, and filiform papilla development.

  8. Mutant p53: Multiple Mechanisms Define Biologic Activity in Cancer.

    PubMed

    Kim, Michael Paul; Zhang, Yun; Lozano, Guillermina

    2015-01-01

    The functional importance of p53 as a tumor suppressor gene is evident through its pervasiveness in cancer biology. The p53 gene is the most commonly altered gene in human cancer; however, not all genetic alterations are biologically equivalent. The majority of alterations involve p53 missense mutations that result in the production of mutant p53 proteins. Such mutant p53 proteins lack normal p53 function and may concomitantly gain novel functions, often with deleterious effects. Here, we review characterized mechanisms of mutant p53 gain of function in various model systems. In addition, we review mutant p53 addiction as emerging evidence suggests that tumors may depend on sustained mutant p53 activity for continued growth. We also discuss the role of p53 in stromal elements and their contribution to tumor initiation and progression. Lastly, current genetic mouse models of mutant p53 in various organ systems are reviewed and their limitations discussed.

  9. Mutants of Cercospora kikuchii altered in cercosporin synthesis and pathogenicity

    SciTech Connect

    Upchurch, R.G.; Walker, D.C.; Rollins, J.A.; Ehrenshaft, M.; Daub, M.E. )

    1991-10-01

    The authors have obtained spontaneous and UV-induced stable mutants, altered in the synthesis of cercosporin, of the fungal soybean pathogen Cercospora kikuchii. The mutants were isolated on the basis of colony color on minimal medium. The UV-induced mutants accumulated, at most, 2% of wild-type cercosporin levels on all media tested. In contrast, cercosporin accumulation by the spontaneous mutants was strongly medium regulated, occurring only on potato dextrose medium but at concentrations comparable to those produced by the wild-type strain. UV-induced mutants unable to synthesize cercosporin on any medium were unable to incite lesions when inoculated onto the soybean host. Cercosporin was reproducibly isolated from all inoculated leaves showing lesions. Although cercosporin involvement in disease has been indirectly suggested by many previous studies, this is the first report in which mutants blocked in cercosporin synthesis have been used to demonstrate that cercosporin is a crucial pathogenicity factor for this fungal genus.

  10. Mutants of Cercospora kikuchii Altered in Cercosporin Synthesis and Pathogenicity.

    PubMed

    Upchurch, R G; Walker, D C; Rollins, J A; Ehrenshaft, M; Daub, M E

    1991-10-01

    We have obtained spontaneous and UV-induced stable mutants, altered in the synthesis of cercosporin, of the fungal soybean pathogen Cercospora kikuchii. The mutants were isolated on the basis of colony color on minimal medium. The UV-induced mutants accumulated, at most, 2% of wild-type cercosporin levels on all media tested. In contrast, cercosporin accumulation by the spontaneous mutants was strongly medium regulated, occurring only on potato dextrose medium but at concentrations comparable to those produced by the wild-type strain. UV-induced mutants unable to synthesize cercosporin on any medium were unable to incite lesions when inoculated onto the soybean host. Cercosporin was reproducibly isolated from all inoculated leaves showing lesions. Although cercosporin involvement in disease has been indirectly suggested by many previous studies, this is the first report in which mutants blocked in cercosporin synthesis have been used to demonstrate that cercosporin is a crucial pathogenicity factor for this fungal genus.

  11. Characterization of Halobacterium halobium mutants defective in taxis.

    PubMed Central

    Sundberg, S A; Alam, M; Lebert, M; Spudich, J L; Oesterhelt, D; Hazelbauer, G L

    1990-01-01

    Mutant derivatives of Halobacterium halobium previously isolated by using a procedure that selected for defective phototactic response to white light were examined for an array of phenotypic characteristics related to phototaxis and chemotaxis. The properties tested were unstimulated swimming behavior, behaviorial responses to temporal gradients of light and spatial gradients of chemoattractants, content of photoreceptor pigments, methylation of methyl-accepting taxis proteins, and transient increases in rate of release of volatile methyl groups induced by tactic stimulation. Several distinct phenotypes were identified, corresponding to a mutant missing photoreceptors, a mutant defective in the methyltransferase, a mutant altered in control of the methylesterase, and mutants apparently defective in intracellular signaling. All except the photoreceptor mutant were defective in both chemotaxis and phototaxis. Images PMID:2332402

  12. Characterization of Halobacterium halobium mutants defective in taxis.

    PubMed

    Sundberg, S A; Alam, M; Lebert, M; Spudich, J L; Oesterhelt, D; Hazelbauer, G L

    1990-05-01

    Mutant derivatives of Halobacterium halobium previously isolated by using a procedure that selected for defective phototactic response to white light were examined for an array of phenotypic characteristics related to phototaxis and chemotaxis. The properties tested were unstimulated swimming behavior, behaviorial responses to temporal gradients of light and spatial gradients of chemoattractants, content of photoreceptor pigments, methylation of methyl-accepting taxis proteins, and transient increases in rate of release of volatile methyl groups induced by tactic stimulation. Several distinct phenotypes were identified, corresponding to a mutant missing photoreceptors, a mutant defective in the methyltransferase, a mutant altered in control of the methylesterase, and mutants apparently defective in intracellular signaling. All except the photoreceptor mutant were defective in both chemotaxis and phototaxis.

  13. Mutant p53: Multiple Mechanisms Define Biologic Activity in Cancer

    PubMed Central

    Kim, Michael Paul; Zhang, Yun; Lozano, Guillermina

    2015-01-01

    The functional importance of p53 as a tumor suppressor gene is evident through its pervasiveness in cancer biology. The p53 gene is the most commonly altered gene in human cancer; however, not all genetic alterations are biologically equivalent. The majority of alterations involve p53 missense mutations that result in the production of mutant p53 proteins. Such mutant p53 proteins lack normal p53 function and may concomitantly gain novel functions, often with deleterious effects. Here, we review characterized mechanisms of mutant p53 gain of function in various model systems. In addition, we review mutant p53 addiction as emerging evidence suggests that tumors may depend on sustained mutant p53 activity for continued growth. We also discuss the role of p53 in stromal elements and their contribution to tumor initiation and progression. Lastly, current genetic mouse models of mutant p53 in various organ systems are reviewed and their limitations discussed. PMID:26618142

  14. Eyeglasses elicit effects similar to face-like perceptual expertise: evidence from the N170 response.

    PubMed

    Cao, Xiaohua; Yang, Qi; Hu, Fengpei

    2016-03-01

    Studies of event-related potentials show that the specific N170 response has become a stable electrophysiological hallmark of objects related to expertise in early perceptual processing. In the present study, we investigated whether eyeglasses can elicit N170 effects similar to those elicited by objects of expertise. Our results showed that the N170 response elicited by eyeglasses was larger than the response elicited by objects that do not generate perceptual expertise (e.g., houses). Importantly, we found that eyeglasses could produce a within-category N170 adaptation effect, similar to that produced in response to objects of expertise (e.g., faces). Our results have revealed for the first time that with a large amount of experience, eyeglasses could evoke the face-like N170 response, which suggested that eyeglasses may become an object of perceptual expertise to some human observers.

  15. Autonomic Reactivity of High and Low Ego-Strength Subjects to Repeated Anxiety Eliciting Scenes

    ERIC Educational Resources Information Center

    Boudewyns, Patrick A.; Levis, Donald J.

    1975-01-01

    The purpose of the present experiment was to answer the question of whether patients labeled high or low in "ego-strength" differentially responded to scenes designed either to elicit anxiety or produce little (neutral) affect. (Editor)

  16. ACTH acts via an anterior ventral third ventricular site to elicit grooming behavior.

    PubMed

    Dunn, A J; Hurd, R W

    1986-01-01

    Intracerebroventricular but not parenteral application of ACTH has been shown to elicit excessive grooming behavior in rats and mice. This behavior is elicited by administration of ACTH into the lateral, third, or fourth ventricles. Plugging of the cerebral aqueduct with cold cream fails to prevent grooming in response to lateral ventricle injection of ACTH. However, cold cream plugs in the third ventricle can prevent the subsequent induction of grooming behavior by lateral ventricle injection of ACTH, but only when the plugs are located in the anterior ventral third ventricle in the region of the organum vasculosum laminae terminalis (OVLT) and median eminence. These data suggest the anterior ventral third ventricle as the periventricular site of action of ACTH in eliciting excessive grooming, although it is possible that peptides taken up in this area are transported to other regions to elicit the behavioral response.

  17. Variation in accumulation of isoflavonoids in Phaseoleae seedlings elicited by Rhizopus.

    PubMed

    Aisyah, Siti; Gruppen, Harry; Andini, Silvia; Bettonvil, Monique; Severing, Edouard; Vincken, Jean-Paul

    2016-04-01

    Seeds from seven species of tribe Phaseoleae, i.e. Phaseolus, Vigna, Lablab and Psophocarpus, were investigated for inducibility of isoflavonoids by germination with or without subsequent elicitation with Rhizopus oryzae. Germination alone poorly induced isoflavonoid production (in the range of 0.2-0.7 mg representative compound equivalents (RCE)/g DW), whereas application of Rhizopus onto the seedlings increased the isoflavonoid content considerably (in the range of 0.5-3.3 mg RCE/g DW). The inducibility of different isoflavonoid subclasses in seedlings with Rhizopus varied per species. Isoflavones and isoflavanones were mainly found in elicited seedlings of Phaseolus, Vigna and Lablab, whereas pterocarpans were mainly observed in those of Psophocarpus. Despite their phylogenetic relatedness, the seeds of various species within Phaseoleae appeared to respond differently towards elicitation by Rhizopus during germination. The kind of molecules induced followed the phylogenetic relationship of the various species, but their amounts induced during germination, alone or combined with elicitation, did not.

  18. Practical guidance and ethical considerations for studies using photo-elicitation interviews.

    PubMed

    Bugos, Eva; Frasso, Rosemary; FitzGerald, Elizabeth; True, Gala; Adachi-Mejia, Anna M; Cannuscio, Carolyn

    2014-10-30

    Photo-elicitation is a qualitative interviewing technique that has gained popularity in recent years. It is the foundation for photovoice projects and is a tool well-suited for community-based participatory research. Photo-elicitation yields rich data, and interview participants say these interviews encourage community awareness and engagement. This article draws on 9 studies, conducted by researchers at 3 institutions (the University of Pennsylvania, the Philadelphia Veterans Affairs Medical Center, and the Geisel School of Medicine at Dartmouth) in partnership with community-based organizations and students, in which 303 participants completed photo-elicitation interviews. We offer 8 practical suggestions for overcoming challenges encountered during photo-elicitation research and for managing ethical concerns about the use of visual data in public health research. Our guidelines can inform study design, protocol development, and institutional review board approval.

  19. Practical Guidance and Ethical Considerations for Studies Using Photo-Elicitation Interviews

    PubMed Central

    Bugos, Eva; Frasso, Rosemary; FitzGerald, Elizabeth; True, Gala; Adachi-Mejia, Anna M.

    2014-01-01

    Photo-elicitation is a qualitative interviewing technique that has gained popularity in recent years. It is the foundation for photovoice projects and is a tool well-suited for community-based participatory research. Photo-elicitation yields rich data, and interview participants say these interviews encourage community awareness and engagement. This article draws on 9 studies, conducted by researchers at 3 institutions (the University of Pennsylvania, the Philadelphia Veterans Affairs Medical Center, and the Geisel School of Medicine at Dartmouth) in partnership with community-based organizations and students, in which 303 participants completed photo-elicitation interviews. We offer 8 practical suggestions for overcoming challenges encountered during photo-elicitation research and for managing ethical concerns about the use of visual data in public health research. Our guidelines can inform study design, protocol development, and institutional review board approval. PMID:25357257

  20. Auditory Evoked Fields Elicited by Spectral, Temporal, and Spectral–Temporal Changes in Human Cerebral Cortex

    PubMed Central

    Okamoto, Hidehiko; Teismann, Henning; Kakigi, Ryusuke; Pantev, Christo

    2012-01-01

    Natural sounds contain complex spectral components, which are temporally modulated as time-varying signals. Recent studies have suggested that the auditory system encodes spectral and temporal sound information differently. However, it remains unresolved how the human brain processes sounds containing both spectral and temporal changes. In the present study, we investigated human auditory evoked responses elicited by spectral, temporal, and spectral–temporal sound changes by means of magnetoencephalography. The auditory evoked responses elicited by the spectral–temporal change were very similar to those elicited by the spectral change, but those elicited by the temporal change were delayed by 30–50 ms and differed from the others in morphology. The results suggest that human brain responses corresponding to spectral sound changes precede those corresponding to temporal sound changes, even when the spectral and temporal changes occur simultaneously. PMID:22593751

  1. Fatty acid biosynthesis in novel ufa mutants of Neurospora crassa.

    PubMed

    Goodrich-Tanrikulu, M; Stafford, A E; Lin, J T; Makapugay, M I; Fuller, G; McKeon, T A

    1994-10-01

    New mutants of Neurospora crassa having the ufa phenotype have been isolated. Two of these mutants, like previously identified ufa mutants, require an unsaturated fatty acid for growth and are almost completely blocked in the de novo synthesis of unsaturated fatty acids. The new mutations map to a different chromosomal location than previously characterized ufa mutations. This implies that at least one additional genetic locus controls the synthesis of unsaturated fatty acids in Neurospora.

  2. Mutant Proteins--Enzymes to Hydrolyze Toxic Organophosphates.

    DTIC Science & Technology

    1987-06-15

    strains of infectious bacteria and the serine protease’ lytic protease. We also employ novel chemical modifications of ; mutant proteins to achieve...mutant RTEM -1 8-lactamase. We have previously generated and characterized mutants of RTEM -1 .- lactamase with all possible amino acid substitutions (site...denaturation than wild-type -lactamase. Uniquely among class A B- lactamases, the RTEM -1 (and RTEM -2) enzymes contain a single disulfide bond between Cys

  3. Optimized cell transplantation using adult rag2 mutant zebrafish

    PubMed Central

    Tang, Qin; Abdelfattah, Nouran S.; Blackburn, Jessica S.; Moore, John C.; Martinez, Sarah A.; Moore, Finola E.; Lobbardi, Riadh; Tenente, Inês M.; Ignatius, Myron S.; Berman, Jason N.; Liwski, Robert S.; Houvras, Yariv; Langenau, David M.

    2014-01-01

    Cell transplantation into adult zebrafish has lagged behind mouse due to the lack of immune compromised models. Here, we have created homozygous rag2E450fs mutant zebrafish that have reduced numbers of functional T and B cells but are viable and fecund. Mutant fish engraft zebrafish muscle, blood stem cells, and cancers. rag2E450fs mutant zebrafish are the first immune compromised zebrafish model that permits robust, long-term engraftment of multiple tissues and cancer. PMID:25042784

  4. Isolation and characterization of Klebsiella pneumoniae unencapsulated mutants

    SciTech Connect

    Benedi, V.J.; Ciurana, B.; Tomas, J.M.

    1989-01-01

    Klebsiella pneumoniae mutants were obtained after UV irradiation and negative selection with anticapsular serum. Unencapsulation, rather than expression of a structurally altered capsule, was found in the mutants. The mutant strains showed no alterations in their outer membrane proteins and lipopolysaccharide, and a great similarity with the wild type in the properties tested (serum resistance, antimicrobial sensitivity, and lipopolysaccharide-specific bacteriophage sensitivity), with the exception of a higher cell surface hydrophobicity and resistance to bacteriophage FC3-9.

  5. [Eremothecium ashbyii mutants resistant to 2,6-diaminopurine].

    PubMed

    Stepanov, A I; Beburov, M Iu; Zhdanov, V G

    1975-01-01

    3 groups of Eremothecium ashbyii mutants resistant to 5-10(-3) M 2,6-diaminopurine (DAP) ahve been obtained. The mutants of the 1st group (Dap-r) are selected from the initial susceptible strain by the ability to grow in the presence of 5-10(-3) M DAP. The mutants of the 2nd group (Azg-Dap-r) are selected in the selective background of two analogues of 5-10(-3) M DAP and 10(-4) M 8-azaguanine (AG). The mutants of the 3rd group (Azg-r - DAP-r) are isolated from the mutant Azg-r 34 resistant to 10(-4) M AG. The results of studying cross-resistance of mutants to DAP, AG and 8-azaadenine (AA) show that Dap-r and Azg-Dap-r mutants in contrast to Azg-r - Dap-r, have common phenotypic properties and can grow only on the analogues of adenine. DAP, but not AA, eliminates the inhibitory effect of AG on the growth of these mutants. This effect is probably due to deaminating DAP to guanine. Mutants Azg-r - Dap-r retain the initial resistance to 10(-4) M AG, but are susceptible to higher concentrations of AG and in this case DAP does not eliminate the inhibitory effect of AG. In all mutants obtained the effectiveness of the incorporation of 14C-adenine (but not 14C-guanine) is sharply reduced, thus indicating the absence of adenosine-monophosphate pyrophosphorylase activity. The mutants do not excrete purine-like compounds into the medium. In the course of the continuous growth of mutants in the presence of DAP but not of guanine the red intracellular pigment is formed which seems to be a complex of riboflavin with DAP. A disturbance in the synthesis of adenosine monophosphate pyrophosphorylase does not influence practically the level of the synthesis of riboflavin in E. ashbyii.

  6. Cellular Plasticity and Heterogeneity of EGFR Mutant Lung Cancer

    DTIC Science & Technology

    2015-09-01

    AWARD NUMBER: W81XWH-14-1-0177 TITLE: Cellular Plasticity and Heterogeneity of EGFR Mutant Lung Cancer PRINCIPAL INVESTIGATOR: Katerina Politi...CONTRACT NUMBER Cellular Plasticity and Heterogeneity of EGFR Mutant Lung Cancer 5b. GRANT NUMBER W81XWH-14-1-0177 5c. PROGRAM ELEMENT NUMBER 6...Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Phenotypic changes have been observed in EGFR mutant lung cancers that become resistant to targeted

  7. Division pattern of a round mutant of Escherichia coli.

    PubMed Central

    Cooper, S

    1997-01-01

    A round mutant of Escherichia coli, when grown in Methocel medium, forms chains of cells and does not form tetrads. This implies that successive division planes of the round mutant are parallel rather than perpendicular. These results differ from a previous proposal that division planes in this round mutant are perpendicular to the prior division plane (W. D. Donachie, S. Addinall, and K. Begg, Bioessays 17:569-576, 1995). PMID:9287016

  8. Implementation of the PR&PP methodology: the role of formal expert elicitations

    SciTech Connect

    Pilat, Joseph F

    2010-01-01

    The application of the methodology developed by the GenIV International Forum's (GIF's) Proliferation Resistance and Physical Protection (PR&PP) Working Group is an expert elicitation. Although the framework of the methodology is structured and systematic, it does not by itself constitute or require a formal elicitation. However, formal elicitation can be utilized in the PR&PP context to provide a systematic, credible and transparent qualitative analysis and develop input for quantitative analyses. This section provides an overview of expert elicitations, a discussion of the role formal expert elicitations can play in the PR&PP methodology, an outline of the formal expert elicitation process and a brief practical guide to conducting formal expert elicitations. Expert elicitation is a process utilizing knowledgeable people in cases, for example, when an assessment is needed but physically based data is absent or open to interpretation. More specifically, it can be used to: (1) predict future events; (2) provide estimates on new, rare, complex or poorly understood phenomena; (3) integrate or interpret existing information; or (4) determine what is currently known, how well it is known or what is worth learning in a field. Expert elicitation can be informal or formal. The informal application of expert judgment is frequently used. Although it can produce good results, it often provides demonstrably biased or otherwise flawed answers to problems. This along with the absence of transparency can result in a loss of confidence when experts speak on issues. More formal expert elicitation is a structured process that makes use of people knowledgeable in certain areas to make assessments. The reason for advocating formal use is that the quality and accuracy of expert judgment comes from the completeness of the expert's understanding of the phenomena and the process used to elicit and analyze the data. The use of a more formal process to obtain, lU1derstand and analyze expert

  9. BAC Transgenic Mice Expressing a Truncated Mutant Parkin Exhibit Age-dependent Hypokinetic Motor Deficits, Dopaminergic Neuron Degeneration, and Accumulation of Proteinase K-Resistant Alpha-Synuclein

    PubMed Central

    Lu, Xiao-Hong; Fleming, Sheila M.; Meurers, Bernhard; Ackerson, Larry C.; Mortazavi, Farzad; Lo, Victor; Hernandez, Daniela; Sulzer, David; Jackson, George R.; Maidment, Nigel T.; Chesselet, Marie-Francoise; Yang, X. William

    2009-01-01

    Summary Recessive mutations in parkin are the most common cause of familial early onset Parkinson's disease (PD). Recent studies suggest that certain parkin mutants may exert dominant toxic effects to cultured cells and such dominant toxicity can lead to progressive dopaminergic (DA) neuron degeneration in Drosophila. To explore whether mutant parkin could exert similar pathogenic effects to mammalian DA neurons in vivo, we developed a Bacterial Artificial Chromosome (BAC) transgenic mouse model expressing a C-terminal truncated human mutant parkin (Parkin-Q311X) in DA neurons driven by a dopamine transporter promoter. Parkin-Q311X mice exhibit multiple late-onset and progressive hypokinetic motor deficits. Stereological analyses reveal that the mutant mice develop age-dependent DA neuron degeneration in substantia nigra accompanied by a significant loss of DA neuron terminals in the striatum. Neurochemical analyses reveal a significant reduction of the striatal dopamine level in mutant mice, which is significantly correlated with their hypokinetic motor deficits. Finally, mutant Parkin-Q311X mice, but not wild-type controls, exhibit age-dependent accumulation of proteinase-K resistant endogenous α-synuclein in substantia nigra and co-localized with 3-nitrotyrosine, a marker for oxidative protein damage. Hence, our study provides the first mammalian genetic evidence that dominant toxicity of a parkin mutant is sufficient to elicit age-dependent hypokinetic motor deficits and DA neuron loss in vivo, and uncovers a causal relationship between dominant parkin toxicity and progressive α-synuclein accumulation in DA neurons. Our study underscores the need to further explore the putative link between parkin dominant toxicity and PD. PMID:19228951

  10. Multiple loci of Pseudomonas syringae pv. syringae are involved in pathogenicity on bean: restoration of one lesion-deficient mutant requires two tRNA genes.

    PubMed Central

    Rich, J J; Willis, D K

    1997-01-01

    A mutational analysis of lesion-forming ability was undertaken in Pseudomonas syringae pv. syringae B728a, causal agent of bacterial brown spot disease of bean. Following a screen of 6,401 Tn5-containing derivatives of B728a on bean pods, 26 strains that did not form disease lesions were identified. Nine of the mutant strains were defective in the ability to elicit the hypersensitive reaction (HR) and were shown to contain Tn5 insertions within the P. syringae pv. syringae hrp region. Ten HR+ mutants were defective in the production of the toxin syringomycin, and a region of the chromosome implicated in the biosynthesis of syringomycin was deleted in a subset of these mutants. The remaining seven lesion-defective mutants retained the ability to produce protease and syringomycin. Marker exchange mutagenesis confirmed that the Tn5 insertion was causal to the mutant phenotype in several lesion-defective, HR+ strains. KW239, a lesion- and syringomycin-deficient mutant, was characterized at the molecular level. Sequence analysis of the chromosomal region flanking the Tn5 within KW239 revealed strong similarities to a number of known Escherichia coli gene products and DNA sequences: the nusA operon, including the complete initiator tRNA(Met) gene, metY; a tRNA(Leu) gene; the tpiA gene product; and the MrsA protein. Removal of sequences containing the two potential tRNA genes prevented restoration of mutant KW239 in trans. The Tn5 insertions within the lesion-deficient strains examined, including KW239, were not closely linked to each other or to the lemA or gacA genes previously identified as involved in lesion formation by P. syringae pv. syringae. PMID:9079910

  11. Potentially bioaccessible phenolics, antioxidant activity and nutritional quality of young buckwheat sprouts affected by elicitation and elicitation supported by phenylpropanoid pathway precursor feeding.

    PubMed

    Świeca, Michał

    2016-02-01

    This paper presents the study on impact of elicitation and the phenylpropanoid pathway feeding on the nutritional quality, the potentially bioaccessible phenolics and the antioxidant capacity of young buckwheat sprouts. Phenolics content was increased by elicitation and feeding with tyrosine and shikimic acid--an elevation of 30% and 17%, respectively. Antioxidant capacity was improved by feeding with tyrosine--an increase of 16.7% and 17.1% in both untreated and treated sprouts, respectively. The highest protein digestibility was determined for the control sprouts and those obtained after tyrosine feeding. The lowest starch digestibility was found for elicited sprouts obtained from seeds fed with tyrosine (a decrease by 52%). An increase of expected glycemic index by 38% was determined for elicited sprouts obtained after phenylalanine feeding. Starch and protein digestibility were negatively correlated with total phenolics (r = -0.55 and -0.58, respectively), however starch digestibility was also affected by resistant starch content. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Effect of barodenervation on cardiovascular responses elicited from the hypothalamic arcuate nucleus of the rat.

    PubMed

    Kawabe, Tetsuya; Kawabe, Kazumi; Sapru, Hreday N

    2012-01-01

    We have previously reported that chemical stimulation of the hypothalamic arcuate nucleus (ARCN) in the rat elicited increases as well as decreases in blood pressure (BP) and sympathetic nerve activity (SNA). The type of response elicited from the ARCN (i.e., increase or decrease in BP and SNA) depended on the level of baroreceptor activity which, in turn, was determined by baseline BP in rats with intact baroreceptors. Based on this information, it was hypothesized that baroreceptor unloading may play a role in the type of response elicited from the ARCN. Therefore, the effect of barodenervation on the ARCN-induced cardiovascular and sympathetic responses and the neurotransmitters in the hypothalamic paraventricular nucleus (PVN) mediating the excitatory responses elicited from the ARCN were investigated in urethane-anesthetized adult male Wistar rats. Bilateral barodenervation converted decreases in mean arterial pressure (MAP) and greater splanchnic nerve activity (GSNA) elicited by chemical stimulation of the ARCN with microinjections of N-methyl-D-aspartic acid to increases in MAP and GSNA and exaggerated the increases in heart rate (HR). Combined microinjections of NBQX and D-AP7 (ionotropic glutamate receptor antagonists) into the PVN in barodenervated rats converted increases in MAP and GSNA elicited by the ARCN stimulation to decreases in MAP and GSNA and attenuated increases in HR. Microinjections of SHU9119 (a melanocortin 3/4 receptor antagonist) into the PVN in barodenervated rats attenuated increases in MAP, GSNA and HR elicited by the ARCN stimulation. ARCN neurons projecting to the PVN were immunoreactive for proopiomelanocortin, alpha-melanocyte stimulating hormone (alpha-MSH) and adrenocorticotropic hormone (ACTH). It was concluded that increases in MAP and GSNA and exaggeration of tachycardia elicited by the ARCN stimulation in barodenervated rats may be mediated via release of alpha-MSH and/or ACTH and glutamate from the ARCN neurons projecting

  13. Modification of motivated behavior elicited by electrical stimulation of the hypothalamus.

    PubMed

    Valenstein, E S; Cox, V C; Kakolewski, J W

    1968-03-08

    Previous reports demonstrated that hypothalamic stimulation may elicit either eating, drinking, or gnawing and emphasized both the specificity of the neural circuits mediating these behaviors and the similarity to behavior during natural-drive states such as hunger and thirst. We find that, after a period of very consistent elicitation of one of these behaviors, the animal may exhibit an equally consistent alternate behavior. A learning component is implicated in the association of hypothalamic stimulation with a particular behavior pattern.

  14. Evaluation of Antioxidant and Antibacterial Potentials of Nigella sativa L. Suspension Cultures under Elicitation

    PubMed Central

    Chaudhry, Hera; Fatima, Nida; Ahmad, Iffat Zareen

    2015-01-01

    Nigella sativa L. (family Ranunculaceae) is an annual herb of immense medicinal properties because of its major active components (i.e., thymoquinone (TQ), thymohydroquinone (THQ), and thymol (THY)). Plant tissue culture techniques like elicitation, Agrobacterium mediated transformation, hairy root culture, and so on, are applied for substantial metabolite production. This study enumerates the antibacterial and antioxidant potentials of N. sativa epicotyl suspension cultures under biotic and abiotic elicitation along with concentration optimization of the elicitors for enhanced TQ and THY production. Cultures under different concentrations of pectin and manganese chloride (MnCl2) elicitation (i.e., 5 mg/L, 10 mg/L, and 15 mg/L) showed that the control, MnCl2 10 mg/L, and pectin 15 mg/L suspension extracts greatly inhibited the growth of E. coli, S. typhimurium, and S. aureus (MIC against E. coli, i.e., 2.35 ± 0.8, 2.4 ± 0.2, and 2.46 ± 0.5, resp.). Elicitation decreased SOD enzyme activity whereas CAT enzyme activity increased remarkably under MnCl2 elicitation. MnCl2 10 mg/L and pectin 15 mg/L elicitation enhanced the DPPH radical inhibition ability, but ferric scavenging activity was comparable to the control. TQ and THY were quantified by LC-MS/MS in the cultures with high bioactive properties revealing maximum content under MnCl2 10 mg/L elicitation. Therefore, MnCl2 elicitation can be undertaken on large scale for sustainable metabolite production. PMID:26347883

  15. Extending Hypothesis Testing of Edge Organizations Using Functional Magnetic Resonance Imaging (fMRI) During ELICIT

    DTIC Science & Technology

    2010-06-01

    task difficulty and response correctness on neural systems supporting fluid reasoning. Cognitive Neurodynamics 1 (1): 71-84. Kaplan, J.T., Iacoboni...dynamic influences on decision-making and trust during social interaction. ELICITing Behavior ELICIT is designed to explore social and cognitive ...a person’s own self-awareness in the game experience, (2) their cognitive processes of reasoning, and (3) the modulation of uncertainty that primes

  16. Intermittent Hypoxia Elicits Prolonged Restoration of Motor Function in Human SCI

    DTIC Science & Technology

    2012-10-01

    AD_________________ Award Number: W81XWH-10-1-0831 TITLE: Intermittent Hypoxia Elicits Prolonged Restoration of Motor Function in...Sep 30 2010 – Sep 29 2012 4. TITLE AND SUBTITLE Intermittent Hypoxia Elicits Prolonged Restoration of Motor 5a. CONTRACT NUMBER Function in...injured (SCI) subjects designed to test the effects of a novel therapy, termed acute intermittent hypoxia (AIH), on voluntary limb function

  17. Assessing communicative intents in young children: low structured observation or elicitation tasks?

    PubMed

    Coggins, T E; Olswang, L B; Guthrie, J

    1987-02-01

    This longitudinal study examines the effectiveness of two different assessment methodologies, low structured observation and structured elicitation tasks, to obtain communicative intents from 35 sensorimotor children. The subjects, 9 months of age at the onset of the study, were observed under the two experimental conditions every 3 months, for a 15-month period. The results reveal differences between the two approaches that vary according to the age of the child and eliciting context. The implications of the findings are examined.

  18. Evaluation of Antioxidant and Antibacterial Potentials of Nigella sativa L. Suspension Cultures under Elicitation.

    PubMed

    Chaudhry, Hera; Fatima, Nida; Ahmad, Iffat Zareen

    2015-01-01

    Nigella sativa L. (family Ranunculaceae) is an annual herb of immense medicinal properties because of its major active components (i.e., thymoquinone (TQ), thymohydroquinone (THQ), and thymol (THY)). Plant tissue culture techniques like elicitation, Agrobacterium mediated transformation, hairy root culture, and so on, are applied for substantial metabolite production. This study enumerates the antibacterial and antioxidant potentials of N. sativa epicotyl suspension cultures under biotic and abiotic elicitation along with concentration optimization of the elicitors for enhanced TQ and THY production. Cultures under different concentrations of pectin and manganese chloride (MnCl2) elicitation (i.e., 5 mg/L, 10 mg/L, and 15 mg/L) showed that the control, MnCl2 10 mg/L, and pectin 15 mg/L suspension extracts greatly inhibited the growth of E. coli, S. typhimurium, and S. aureus (MIC against E. coli, i.e., 2.35 ± 0.8, 2.4 ± 0.2, and 2.46 ± 0.5, resp.). Elicitation decreased SOD enzyme activity whereas CAT enzyme activity increased remarkably under MnCl2 elicitation. MnCl2 10 mg/L and pectin 15 mg/L elicitation enhanced the DPPH radical inhibition ability, but ferric scavenging activity was comparable to the control. TQ and THY were quantified by LC-MS/MS in the cultures with high bioactive properties revealing maximum content under MnCl2 10 mg/L elicitation. Therefore, MnCl2 elicitation can be undertaken on large scale for sustainable metabolite production.

  19. Characterization and classification of zebrafish brain morphology mutants

    PubMed Central

    Lowery, Laura Anne; De Rienzo, Gianluca; Gutzman, Jennifer H.; Sive, Hazel

    2010-01-01

    The mechanisms by which the vertebrate brain achieves its three-dimensional structure are clearly complex, requiring the functions of many genes. Using the zebrafish as a model, we have begun to define genes required for brain morphogenesis, including brain ventricle formation, by studying 16 mutants previously identified as having embryonic brain morphology defects. We report the phenotypic characterization of these mutants at several time-points, using brain ventricle dye injection, imaging, and immunohistochemistry with neuronal markers. Most of these mutants display early phenotypes, affecting initial brain shaping, while others show later phenotypes, affecting brain ventricle expansion. In the early phenotype group, we further define four phenotypic classes and corresponding functions required for brain morphogenesis. Although we did not use known genotypes for this classification, basing it solely on phenotypes, many mutants with defects in functionally related genes clustered in a single class. In particular, class 1 mutants show midline separation defects, corresponding to epithelial junction defects; class 2 mutants show reduced brain ventricle size; class 3 mutants show midbrain-hindbrain abnormalities, corresponding to basement membrane defects; and class 4 mutants show absence of ventricle lumen inflation, corresponding to defective ion pumping. Later brain ventricle expansion requires the extracellular matrix, cardiovascular circulation, and transcription/splicing-dependent events. We suggest that these mutants define processes likely to be used during brain morphogenesis throughout the vertebrates. PMID:19051268

  20. Growth and development of maize that contains mutant tubulin genes

    SciTech Connect

    Susan M. Wick

    2004-07-23

    Mutant maize plants containing a Mu transposon disrupting one of the five beta tubulin genes of interest were followed for several generations and hybridized with each other to produce plants containing disruptions in both copies of a single gene or disruption of more than one tubulin gene. Seedlings of some of these plants were grown under chilling conditions for a few weeks. After DOE funding ended, plants have been assessed to see whether mutant are more or less tolerant to chilling. Other mutant plants will be assessed for their male and female fertility relative to non-mutant siblings or other close relatives.

  1. ERAD-icating mutant insulin promotes functional insulin secretion.

    PubMed

    Moore, Daniel J

    2017-01-18

    Overexpression of a chaperone protein liberates functional insulin from a misfolded mutant partner to improve insulin secretion. Copyright © 2017, American Association for the Advancement of Science.

  2. Identification of mutant monoclonal antibodies with increased antigen binding.

    PubMed

    Pollock, R R; French, D L; Gefter, M L; Scharff, M D

    1988-04-01

    Sib selection and an ELISA have been used to isolate hybridoma subclones producing mutant antibodies that bind antigen better than the parental monoclonal antibody. Such mutants arise spontaneously in culture at frequencies of 2.5-5 X 10(-5). The sequences of the heavy and light chain variable regions of the mutant antibodies are identical to that of the parent and the Ka values of the mutants and the parent are the same. The increase in binding is associated with abnormalities of the constant region polypeptide and probably reflect changes in avidity of these antibodies.

  3. Selection of Diquat Resistance Photosynthesis Mutants from Maize 12

    PubMed Central

    Miles, C. Donald

    1976-01-01

    Resistance of a seedling to the herbicide 1,1′-ethylene-2,2′-dipyridylium bromide (diquat) can be used as a selective technique for photosynthesis mutants in Zea mays L. Diquat requires reduction by the light reaction in order to kill leaf cells and, therefore, nonphotosynthetic mutants survive. This technique was tested using known mutants and is applicable to larger samples of plants than previous techniques. Resistance to diquat should allow selection of mutants on the oxidizing side of photosystem II which are not previously available in higher plants. Images PMID:16659467

  4. [Pigment composition and photosynthetic activity of pea chlorophyll mutants].

    PubMed

    Ladygin, V G

    2003-01-01

    Pea chlorophyll mutants chlorotica 2004 and 2014 have been studied. The mutants differ from the initial form (pea cultivar Torsdag) in stem and leaf color (light green in the mutant 2004 and yellow-green in the mutant 2014), relative chlorophyll content (approximately 80 and 50%, respectively), and the composition of carotenoids: the mutant 2004 contains a significantly smaller amount of carotene but accumulates more lutein and violaxanthine; in the mutant 2014, the contents of all carotenoids are decreased proportionally to the decrease in chlorophyll content. It is shown that the rates of CO2 assimilation and oxygen production in the mutant chlorotica 2004 and 2014 plants are reduced. The quantum efficiency of photosynthesis in the mutants is 29-30% lower than in the control plants; in their hybrids, however, it is 1.5-2 higher. It is proposed that both the greater role of dark respiration in gas exchange and the reduced photosynthetic activity in chlorotica mutants are responsible for the decreased phytomass increment in these plants. On the basis of these results, the conclusion is drawn that the mutations chlorotica 2004 and 2014 affect the genes controlling the formation and functioning of various components of the photosynthetic apparatus.

  5. Sulphate metabolism of selenate-resistant Schizosaccharomyces pombe mutants.

    PubMed

    Bánszky, Luca; Simonics, Tibor; Maráz, Anna

    2003-10-01

    Selenate-resistant mutants were obtained from several strains of Schizosaccharomyces pombe. The obtained mutants all belonged to the same genetic complementation group. They were low in sulphate uptake activity and in ATP sulphurylase activity. They grew on medium containing sulphite, thiosulphate, cysteine or glutathione but not methionine as the sole source of sulphur. From these results, the mutants were concluded to carry mutations in the ATP sulphurylase gene. Inability of the mutants to utilize methionine as a sulphur source is rationalized by the absence of the reverse transsulphurylation pathway in this organism; wild type strains must utilize methionine as a sulphur source after it is degraded to give rise to sulphate.

  6. Low zone tolerance requires ICAM-1 expression to limit contact hypersensitivity elicitation.

    PubMed

    Komura, Kazuhiro; Iwata, Yohei; Ogawa, Fumihide; Yoshizaki, Ayumi; Yamaoka, Toshifumi; Akiyama, Yuichiro; Hara, Toshihide; Hasegawa, Minoru; Fujimoto, Manabu; Sato, Shinichi

    2009-11-01

    Painting subsensitizing doses of contact sensitizers on skin (low-dose tolerization) induces antigen (Ag)-specific tolerance, known as low zone tolerance (LZT), which has been experimentally demonstrated by the inhibition of contact hypersensitivity (CHS). Although LZT resulted from the inhibition of the sensitization phase, the effects on the effector/elicitation phase remain unknown. L-selectin and ICAM-1 regulate leukocyte influx into inflamed tissues during the elicitation phase of CHS. LZT was investigated in mice lacking either L-selectin or ICAM-1 to evaluate the roles these leukocyte receptors play in LZT during the elicitation phase. Low-dose tolerization effectively suppressed CHS in wild-type and L-selectin-deficient mice, but not in ICAM-1-deficient mice. Low-dose-tolerized ICAM-1-deficient splenocytes effectively suppressed the elicitation phase in naive wild-type recipients. Sensitized ICAM-1-deficient splenocytes showed normal proliferative responses to the sensitizing Ag and generated normal CHS in wild-type recipients. Thus, ICAM-1 deficiency did not affect sensitization. LZT was associated with a lack of ICAM-1 upregulation after elicitation, suggesting a potentially mechanistic role for ICAM-1. The blockade of IL-10, a possible mediator of LZT, produced by hapten-specific suppressor cells, abrogated LZT and restored ICAM-1 upregulation. These results indicate that low-dose tolerization controls CHS by abrogating ICAM-1 upregulation during the elicitation phase.

  7. Mechanisms underlying the sympathomimetic cardiovascular responses elicited by gamma-hydroxybutyrate.

    PubMed

    Hicks, Alissa R; Kapusta, Daniel R; Varner, Kurt J

    2004-12-01

    Gamma-hydroxybutyrate (GHB) is generally thought to be a central nervous system depressant; however, GHB also has sympathomimetic cardiovascular actions. Radio telemetry was used to record the cardiovascular responses elicited by GHB (180-1000 mg/kg IV) in conscious rats. GHB elicited increases in mean arterial pressure (MAP) (24 +/- 3 to 60 +/- 5 mm Hg) lasting from 28 +/- 8 to 227 +/- 37 minutes. GHB (560 and 1000 mg/kg IV) also elicited a prolonged tachycardic response (85 +/- 23 and 95 +/- 22 bpm). The hypertension and tachycardia elicited by GHB (560 mg/kg) were reversed by the intravenous and intracerebroventricular administration of the GABAb receptor antagonist CGP 35348. CGP 35348 also reversed GHB-mediated increases in renal sympathetic nerve activity (RSNA). Administration of the purported GHB receptor antagonist NCS-382 reversed the increase in heart rate but not the pressor response elicited by GHB in telemetered rats. These data indicate that the intravenous administration of GHB markedly increases MAP, heart rate, and RSNA in conscious rats via activation of central GABAb receptors. In addition, GHB receptors appear to selectively mediate the increase in heart rate elicited by large doses of GHB.

  8. Elicitation threshold of cobalt chloride: analysis of patch test dose-response studies.

    PubMed

    Fischer, Louise A; Johansen, Jeanne D; Voelund, Aage; Lidén, Carola; Julander, Anneli; Midander, Klara; Menné, Torkil; Thyssen, Jacob P

    2016-02-01

    Cobalt is a strong skin sensitizer (grade 5 of 5 in the guinea-pig maximization test) that is used in various industrial and consumer applications. To prevent sensitization to cobalt and elicitation of allergic cobalt dermatitis, information about the elicitation threshold level of cobalt is important. To identify the dermatitis elicitation threshold levels in cobalt-allergic individuals. Published patch test dose-response studies were reviewed to determine the elicitation dose (ED) levels in dermatitis patients with a previous positive patch test reaction to cobalt. A logistic dose-response model was applied to data collected from the published literature to estimate ED values. The 95% confidence interval (CI) for the ratio of mean doses that can elicit a reaction in 10% (ED(10)) of a population was calculated with Fieller's method. On the basis of five included studies, the ED10 values of aqueous cobalt chloride ranged between 0.0663 and 1.95 µg cobalt/cm(2), corresponding to 30.8-259 ppm. Our analysis provides an overview of the doses of cobalt that are required to elicit allergic cobalt contactdermatitis in sensitized individuals, and thereby the basis for future prevention of cobalt allergy. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Stabilization of F-actin prevents cAMP-elicited Cl- secretion in T84 cells.

    PubMed Central

    Shapiro, M; Matthews, J; Hecht, G; Delp, C; Madara, J L

    1991-01-01

    T84 cells, a human intestinal epithelial cell line, serve as a model of electrogenic Cl- secretion. We find that cAMP-elicited Cl- secretion in T84 cells is accompanied by a marked redistribution of F-actin in the basolateral portion of the cell. To prevent this F-actin redistribution and thereby assess its importance to Cl- secretion, we have defined simple conditions under which this model epithelium can be loaded with nitrobenzoxadiazole (NBD)-phallicidin. This reagent binds F-actin with high affinity thus stabilizing the F-actin cytoskeleton by preventing depolymerization, an event necessary for dynamic reordering of actin microfilaments. NBD-phallicidin loading is not cytotoxic as assessed by lactic dehydrogenase release, protein synthesis, transepithelial resistance, and the ability of the loaded cells to pump Na+ in an absorptive direction in response to the apical addition of a Na+ ionophore. However, cAMP-elicited redistribution of F-actin and the cAMP-elicited Cl- secretory response are both markedly impaired in NBD-phallicidin preloaded T84 cells. In contrast, the carbachol-elicited Cl- secretory response (Ca++ mediated) is not attenuated by NBD-phallicidin preloading nor is it accompanied by redistribution of F-actin. These findings suggest that the cAMP-elicited cytoskeletal redistribution we describe is an integral part of cAMP-elicited Cl- secretion in T84 cells. Images PMID:1645745

  10. Temperature-sensitive mutants of the slime mould Physarum polycephalum. II. Mutants of the plasmodial phase.

    PubMed

    Gingold, E C; Grant, W D; Wheals, A E; Wren, M

    1976-11-24

    Methods are described for the isolation and testing of temperature-sensitive plasmodial strains of Physarum polycephalum. Nineteen temperature-sensitive strains were found by screening plasmodia derived from mutagenised amoebae and the properties of these are described. A scheme is outlined for the detection of specific mitotic cycle lesions amongst temperature-sensitive strains, and the properties of a presumptive mitotic cycle mutant are described.

  11. Mutant prevention concentration and mutant selection window for 10 antimicrobial agents against Rhodococcus equi.

    PubMed

    Berghaus, Londa J; Giguère, Steeve; Guldbech, Kristen

    2013-10-25

    The objectives of this study were to determine the mutant prevention concentration (MPC), time above the MPC and mutant selection window for 10 antimicrobial agents against Rhodococcus equi and to determine if the combination of a macrolide with rifampin would decrease emergence of resistant mutants. Antimicrobial agents investigated (erythromycin, clarithromycin, azithromycin, rifampin, amikacin, gentamicin, enrofloxacin, vancomycin, imipenem, and doxycycline) were selected based on in vitro activity and frequency of use in foals or people infected with R. equi. Each antimicrobial agent or combination of agents was evaluated against four virulent strains of R. equi. MPC were determined using an agar plate assay. Pharmacodynamic parameters were calculated using published plasma and pulmonary pharmacokinetic variables. There was a significant (P<0.001) effect of the type of antimicrobial agent on the MPC. The MPC of clarithromycin (1.0 μg/ml) was significantly lower and the MPC of rifampin and amikacin (512 and 384 μg/ml, respectively) were significantly higher than that of all other antimicrobial agents tested. Combining erythromycin, clarithromycin, or azithromycin with rifampin resulted in a significant (P≤0.005) decrease in MPC and MPC/MIC ratio. When MIC and MPC were combined with pharmacokinetic variables, only gentamicin and vancomycin were predicted to achieve plasma concentrations above the MPC for any given periods of time. Only clarithromycin and the combination clarithromycin-rifampin were predicted to achieve concentrations in bronchoalveolar cells and pulmonary epithelial lining fluid above the MPC for the entire dosing interval. In conclusion, the combination of a macrolide with rifampin considerably decreases the emergence of resistant mutants of R. equi. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Eliciting symptoms interpreted as normal by patients with early-stage lung cancer: could GP elicitation of normalised symptoms reduce delay in diagnosis? Cross-sectional interview study

    PubMed Central

    Brindle, Lucy; Pope, Catherine; Corner, Jessica; Leydon, Geraldine; Banerjee, Anindo

    2012-01-01

    Objectives To investigate why symptoms indicative of early-stage lung cancer (LC) were not presented to general practitioners (GPs) and how early symptoms might be better elicited within primary care. Design, setting and participants A qualitative cross-sectional interview study about symptoms and help-seeking in 20 patients from three south England counties, awaiting resection of LC (suspected or histologically confirmed). Analysis drew on principles of discourse analysis and constant comparison to identify processes involved in interpretation and communication about symptoms, and explain non-presentation. Results Most participants experienced health changes possibly indicative of LC which had not been presented during GP consultations. Symptoms that were episodic, or potentially caused by ageing or lifestyle, were frequently not presented to GPs. In interviews, open questions about health changes/symptoms in general did not elicit these symptoms; they only emerged in response to closed questions detailing specific changes in health. Questions using disease-related labels, for example, pain or breathlessness, were less likely to elicit symptoms than questions that used non-disease terminology, such as aches, discomfort or ‘getting out of breath’. Most participants described themselves as feeling well and were reluctant to associate potentially explained, non-specific or episodic symptoms with LC, even after diagnosis. Conclusions Patients with early LC are unlikely to present symptoms possibly indicative of LC that they associate with normal processes, when attending primary care before diagnosis. Faced with patients at high LC risk, GPs will need to actively elicit potential LC symptoms not presented by the patient. Closed questions using non-disease terminology might better elicit normalised symptoms. PMID:23166137

  13. Two distinct types of cellular mechanisms in the development of delayed hypersensitivity in mice: requirement of either mast cells or macrophages for elicitation of the response.

    PubMed Central

    Torii, I; Morikawa, S; Harada, T; Kitamura, Y

    1993-01-01

    Using mast cell-deficient mutant W/Wv mice and their normal counterpart we re-evaluated the significance of participation of mast cells in allergic inflammatory response. W/Wv mice developed immediate hypersensitivity (IH) footpad reaction (FPR) to a somewhat lesser degree than the normal mice, suggesting that the mast cell might amplify the response. To exert classical tuberculin (tbc) delayed-type hypersensitivity (DTH) mast cells were not an essential cellular component. Vasoactive amines were essential to develop the response, but it did not necessarily originate from mast cells. When mice were immunized with methylated human serum albumin (MHSA) emulsified in incomplete Freund's adjuvant (IFA), mast cells were required to elicit DTH FPR. This was confirmed by the lack of the response in W/Wv mice, and the restoration of FPR by local transplantation of mature mast cells into mutant mice. This mast cell-dependent (MD) DTH was different from tbc DTH as follows: mast cell dependency, macrophage dependency as revealed by ferritin sensitivity, kinetics of sensitization, effect of host's age and histopathology. Thus we concluded that there are two types of DTH in mice; one is macrophage-dependent tbc and the other is mast cell-dependent DTH. The correspondence of the DTH to the Jones-Mote (JM) DTH is discussed, although the dominance of mast cells in MD DTH lesion was not observed. Images Figure 2 Figure 4 PMID:8478030

  14. Applications of Protein Thermodynamic Database for Understanding Protein Mutant Stability and Designing Stable Mutants.

    PubMed

    Gromiha, M Michael; Anoosha, P; Huang, Liang-Tsung

    2016-01-01

    Protein stability is the free energy difference between unfolded and folded states of a protein, which lies in the range of 5-25 kcal/mol. Experimentally, protein stability is measured with circular dichroism, differential scanning calorimetry, and fluorescence spectroscopy using thermal and denaturant denaturation methods. These experimental data have been accumulated in the form of a database, ProTherm, thermodynamic database for proteins and mutants. It also contains sequence and structure information of a protein, experimental methods and conditions, and literature information. Different features such as search, display, and sorting options and visualization tools have been incorporated in the database. ProTherm is a valuable resource for understanding/predicting the stability of proteins and it can be accessed at http://www.abren.net/protherm/ . ProTherm has been effectively used to examine the relationship among thermodynamics, structure, and function of proteins. We describe the recent progress on the development of methods for understanding/predicting protein stability, such as (1) general trends on mutational effects on stability, (2) relationship between the stability of protein mutants and amino acid properties, (3) applications of protein three-dimensional structures for predicting their stability upon point mutations, (4) prediction of protein stability upon single mutations from amino acid sequence, and (5) prediction methods for addressing double mutants. A list of online resources for predicting has also been provided.

  15. Photoperiod Affects the Phenotype of Mitochondrial Complex I Mutants.

    PubMed

    Pétriacq, Pierre; de Bont, Linda; Genestout, Lucie; Hao, Jingfang; Laureau, Constance; Florez-Sarasa, Igor; Rzigui, Touhami; Queval, Guillaume; Gilard, Françoise; Mauve, Caroline; Guérard, Florence; Lamothe-Sibold, Marlène; Marion, Jessica; Fresneau, Chantal; Brown, Spencer; Danon, Antoine; Krieger-Liszkay, Anja; Berthomé, Richard; Ribas-Carbo, Miquel; Tcherkez, Guillaume; Cornic, Gabriel; Pineau, Bernard; Gakière, Bertrand; De Paepe, Rosine

    2017-01-01

    Plant mutants for genes encoding subunits of mitochondrial complex I (CI; NADH:ubiquinone oxidoreductase), the first enzyme of the respiratory chain, display various phenotypes depending on growth conditions. Here, we examined the impact of photoperiod, a major environmental factor controlling plant development, on two Arabidopsis (Arabidopsis thaliana) CI mutants: a new insertion mutant interrupted in both ndufs8.1 and ndufs8.2 genes encoding the NDUFS8 subunit and the previously characterized ndufs4 CI mutant. In the long day (LD) condition, both ndufs8.1 and ndufs8.2 single mutants were indistinguishable from Columbia-0 at phenotypic and biochemical levels, whereas the ndufs8.1 ndufs8.2 double mutant was devoid of detectable holo-CI assembly/activity, showed higher alternative oxidase content/activity, and displayed a growth retardation phenotype similar to that of the ndufs4 mutant. Although growth was more affected in ndufs4 than in ndufs8.1 ndufs8.2 under the short day (SD) condition, both mutants displayed a similar impairment of growth acceleration after transfer to LD compared with the wild type. Untargeted and targeted metabolomics showed that overall metabolism was less responsive to the SD-to-LD transition in mutants than in the wild type. The typical LD acclimation of carbon and nitrogen assimilation as well as redox-related parameters was not observed in ndufs8.1 ndufs8 Similarly, NAD(H) content, which was higher in the SD condition in both mutants than in Columbia-0, did not adjust under LD We propose that altered redox homeostasis and NAD(H) content/redox state control the phenotype of CI mutants and photoperiod acclimation in Arabidopsis.

  16. Multiple mutant analysis of recombination in yeast.

    PubMed

    Malone, R E

    1983-01-01

    Summary. The RAD6, RAD50, and RAD52 loci have been identified as genes which code for functions which may act during meiotic recombination in yeast (Game et al.1980; Prakash et al. 1980). By use of the spol3-1 mutation,which allows sporulating cells to bypass the first meiotic division, the rad50-1 mutation has been directly implicated as a general meiotic Rec- mutation by examination of viable ascospores (Malone and Esposito 1981). Since the rad6-1 and rad52-1 mutations do not yield viable ascospores in the presence of spol3-1, multiple rad mutants have been constructed and analyzed. This analysis has demonstrated that in meiosis tad50-1 is epistatic to rad52-1, and rad6-1 is epistatic to rad50-1. This suggests that the order of action of these genes during meiosis is RAD6, RAD50, and then RAD52. The data for rad6-1 can be interpreted to suggest that RAD6 may not code for a recombination function,per se, although it may be required for recombination to occur. Analysis of mitotic recombination indicates that rad52-1 is epistatic to rad50-1 ; in mitosis; this is consistent with the hypothesis that the RAD50 gene codes for a recombination function required in meiosis but not in mitosis.

  17. Osmotic-Sensitive Mutant of Salmonella typhimurium

    PubMed Central

    Anton, Dora N.

    1972-01-01

    A strain (DA82) having peculiar osmotic properties was isolated in Salmonella typhimurium. The mutant shows increased elasticity of its cell wall and makes spherical instead of elongated cells, regardless of the osmolality of the medium. The strain withstands dilution in distilled water without disruption or death and grows normally in 0.1 molal NaCl broth (240 milliosmol), but it dies exponentially in low-osmolality broth (40 milliosmol). Addition of salts or sucrose instantly stops death and allows growth and cell division to proceed. Death is not due to lysis because this appears at later times and at a much lower rate. Osmotic inactivation is temperature-dependent: higher death rates occur at higher incubation temperatures. Inhibition of protein synthesis by chloramphenicol (20 μg/ml) prevents osmotic death. At 37 C and at lower temperatures, the phenomenon of osmotic death is transient. After a variable interval, growth of the osmotic-sensitive strain resumes. It is assumed that the strain's osmotic behavior is due to membrane defectiveness. The membrane disfunction and the wall defect shown by the strain may be consequences of a single genetic alteration or the results of independent mutations. Images PMID:4110928

  18. Plasmidless, photosynthetically incompetent mutants of Rhodospirillum rubrum.

    PubMed Central

    Kuhl, S A; Wimer, L T; Yoch, D C

    1984-01-01

    Ethyl methanesulfonate rendered a high percentage of Rhodospirillum rubrum cells plasmidless and photosynthetically incompetent (Kuhl et al., J. Bacteriol. 156:737-742, 1983). By probing restriction endonuclease-digested chromosomal DNA from these plasmidless strains with 32P-labeled R. rubrum plasmid DNA, we showed that no homology exists between the plasmid and the chromosomal DNA of the mutant. Loss of the plasmid in all the nonphotosynthetic isolates was accompanied by the synthesis of spirilloxanthin under aerobic growth conditions, resistance to cycloserine and HgCl2, and loss of ability to grow fermentatively on fructose. Changes in both the protein and lipid composition of the membranes and the impaired uptake of 203HgCl2 in the plasmidless strains (compared with the wild type) suggest either that membrane modification occurs as a result of plasmid loss, accounting for several of the acquired phenotype characteristics of the cured strains, or that both membrane modification and plasmid loss are part of the same pleiotropic mutation. Images PMID:6434514

  19. Osmotic-sensitive mutant of Salmonella typhimurium.

    PubMed

    Antón, D N

    1972-03-01

    A strain (DA82) having peculiar osmotic properties was isolated in Salmonella typhimurium. The mutant shows increased elasticity of its cell wall and makes spherical instead of elongated cells, regardless of the osmolality of the medium. The strain withstands dilution in distilled water without disruption or death and grows normally in 0.1 molal NaCl broth (240 milliosmol), but it dies exponentially in low-osmolality broth (40 milliosmol). Addition of salts or sucrose instantly stops death and allows growth and cell division to proceed. Death is not due to lysis because this appears at later times and at a much lower rate. Osmotic inactivation is temperature-dependent: higher death rates occur at higher incubation temperatures. Inhibition of protein synthesis by chloramphenicol (20 mug/ml) prevents osmotic death. At 37 C and at lower temperatures, the phenomenon of osmotic death is transient. After a variable interval, growth of the osmotic-sensitive strain resumes. It is assumed that the strain's osmotic behavior is due to membrane defectiveness. The membrane disfunction and the wall defect shown by the strain may be consequences of a single genetic alteration or the results of independent mutations.

  20. Mutant Huntingtin Disrupts the Nuclear Pore Complex.

    PubMed

    Grima, Jonathan C; Daigle, J Gavin; Arbez, Nicolas; Cunningham, Kathleen C; Zhang, Ke; Ochaba, Joseph; Geater, Charlene; Morozko, Eva; Stocksdale, Jennifer; Glatzer, Jenna C; Pham, Jacqueline T; Ahmed, Ishrat; Peng, Qi; Wadhwa, Harsh; Pletnikova, Olga; Troncoso, Juan C; Duan, Wenzhen; Snyder, Solomon H; Ranum, Laura P W; Thompson, Leslie M; Lloyd, Thomas E; Ross, Christopher A; Rothstein, Jeffrey D

    2017-04-05

    Huntington's disease (HD) is caused by an expanded CAG repeat in the Huntingtin (HTT) gene. The mechanism(s) by which mutant HTT (mHTT) causes disease is unclear. Nucleocytoplasmic transport, the trafficking of macromolecules between the nucleus and cytoplasm, is tightly regulated by nuclear pore complexes (NPCs) made up of nucleoporins (NUPs). Previous studies offered clues that mHTT may disrupt nucleocytoplasmic transport and a mutation of an NUP can cause HD-like pathology. Therefore, we evaluated the NPC and nucleocytoplasmic transport in multiple models of HD, including mouse and fly models, neurons transfected with mHTT, HD iPSC-derived neurons, and human HD brain regions. These studies revealed severe mislocalization and aggregation of NUPs and defective nucleocytoplasmic transport. HD repeat-associated non-ATG (RAN) translation proteins also disrupted nucleocytoplasmic transport. Additionally, overexpression of NUPs and treatment with drugs that prevent aberrant NUP biology also mitigated this transport defect and neurotoxicity, providing future novel therapy targets.