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Sample records for natural agent deguelin

  1. Synergistic Activity of Deguelin and Fludarabine in Cells from Chronic Lymphocytic Leukemia Patients and in the New Zealand Black Murine Model

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    Rebolleda, Nerea; Losada-Fernandez, Ignacio; Perez-Chacon, Gema; Castejon, Raquel; Rosado, Silvia; Morado, Marta; Vallejo-Cremades, Maria Teresa; Martinez, Andrea; Vargas-Nuñez, Juan A.

    2016-01-01

    B-cell chronic lymphocytic leukemia (CLL) remains an incurable disease, and despite the improvement achieved by therapeutic regimes developed over the last years still a subset of patients face a rather poor prognosis and will eventually relapse and become refractory to therapy. The natural rotenoid deguelin has been shown to induce apoptosis in several cancer cells and cell lines, including primary human CLL cells, and to act as a chemopreventive agent in animal models of induced carcinogenesis. In this work, we show that deguelin induces apoptosis in vitro in primary human CLL cells and in CLL-like cells from the New Zealand Black (NZB) mouse strain. In both of them, deguelin dowregulates AKT, NFκB and several downstream antiapoptotic proteins (XIAP, cIAP, BCL2, BCL-XL and survivin), activating the mitochondrial pathway of apoptosis. Moreover, deguelin inhibits stromal cell-mediated c-Myc upregulation and resistance to fludarabine, increasing fludarabine induced DNA damage. We further show that deguelin has activity in vivo against NZB CLL-like cells in an experimental model of CLL in young NZB mice transplanted with spleen cells from aged NZB mice with lymphoproliferation. Moreover, the combination of deguelin and fludarabine in this model prolonged the survival of transplanted mice at doses of both compounds that were ineffective when administered individually. These results suggest deguelin could have potential for the treatment of human CLL. PMID:27101369

  2. Deguelin Inhibits the Migration and Invasion of U-2 OS Human Osteosarcoma Cells via the Inhibition of Matrix Metalloproteinase-2/-9 in Vitro

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    Hung-Sheng Shang

    2014-10-01

    Full Text Available Osteosarcoma is the most common malignant primary bone tumor in children and young adults and lung metastasis is the main cause of death in those patients. Deguelin, a naturally occurring rotenoid, is known to be an Akt inhibitor and to exhibit cytotoxic effects, including antiproliferative and anticarcinogenic activities, in several cancers. In the present study, we determined if deguelin would inhibit migration and invasion in U-2 OS human osteosarcoma cells. Deguelin significantly inhibited migration and invasion of U-2 OS human osteosarcoma cells which was associated with a reduction of activities of matrix metalloproteinases-2 (MMP-2 and matrix metalloproteinases-9 (MMP-9. Furthermore, results from western blotting indicated that deguelin decreased the cell proliferation and cell growth-associated protein levels, such as SOS1, PKC, Ras, PI3K, p-AKT(Ser473, IRE-1α, MEKK3, iNOS, COX2, p-ERK1/2, p-JNK1/2, p-p38; the cell motility and focal adhesion-associated protein levels, such as Rho A, FAK, ROCK-1; the invasion-associated protein levels, such as TIMP1, uPA, MMP-2. MMP-9, MMP-13, MMP-1 and VEGF in U-2 OS cells. Confocal microscopy revealed that deguelin reduced NF-κB p65, Rho A and ROCK-1 protein levels in cytosol. MMP-7, MMP-9 and Rho A mRNA levels were suppressed by deguelin. These in vitro results provide evidence that deguelin may have potential as a novel anti-cancer agent for the treatment of osteosarcoma and provides the rationale for in vivo studies in animal models.

  3. Deguelin induces both apoptosis and autophagy in cultured head and neck squamous cell carcinoma cells.

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    Yan-li Yang

    Full Text Available Head and neck squamous cell carcinoma (HNSCC represents more than 5% of all cancers diagnosed annually in United States and around the world. Despite advances in the management of patients with this disease, the survival has not been significantly improved, and the search for potential alternative therapies is encouraging. Here we demonstrate that deguelin administration causes a significant HNSCC cell death. Deguelin induces both cell apoptosis and autophagy by modulating multiple signaling pathways in cultured HNSCC cells. Deguelin inhibits Akt signaling, and down-regulates survivin and cyclin-dependent kinase 4 (Cdk4 expressions, by disrupting their association with heat shock protein-90 (Hsp-90. Deguelin induces ceramide production through de novo synthase pathway to promote HNSCC cell death. Importantly, increased ceramide level activates AMP-activated protein kinase (AMPK, which then directly phosphorylates Ulk1 and eventually leads to cell autophagy. We found that a low dose of deguelin sensitized HNSCC cells to 5-FU. Finally, using a nude mice Hep-2 xenograft model, we also showed a significant anti-tumor ability of deguelin in vivo. Together, we suggest that deguelin may represent a novel and effective chemo-agent against HNSCC.

  4. Liposomal encapsulation of deguelin: evidence for enhanced antitumor activity in tobacco carcinogen-induced and oncogenic K-ras-induced lung tumorigenesis.

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    Woo, Jong K; Choi, Dong Soon; Tran, Hai T; Gilbert, Brian E; Hong, Waun Ki; Lee, Ho-Young

    2009-04-01

    Deguelin has shown promising chemopreventive and therapeutic activities in diverse types of cancers. However, the potential side effect of deguelin over a certain dose could be the substantial hurdle in the practical application of the drug. One of the successful strategies for the use of deguelin in clinical trials could be lung-specific delivery of the drug. The present study evaluates the efficacy of liposome-encapsulated deguelin with a dose of 0.4 mg/kg, which is 10 times less than the dose (4 mg/kg) for preventive and therapeutic activities validated in previous in vivo studies. Liposomal deguelin revealed cytotoxic activity in vitro in premalignant and malignant human bronchial epithelial cells and non-small cell lung cancer cells through the same mechanistic pathway previously reported for deguelin (i.e., suppression of the heat shock protein 90 chaperone function and induction of apoptosis). Delivery of liposomal deguelin at a dose of 0.4 mg/kg by intranasal instillation resulted in markedly increased drug partitioning to the lungs compared with that of 4 mg/kg deguelin or 0.4 mg/kg liposomal deguelin administered by oral gavage. Lung-specific delivery of deguelin (0.4 mg/kg) via nasal or intratracheal instillation in a liposomal formulation also showed significant chemopreventive and therapeutic activities in 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone/benzo(a)pyrene-treated A/J mice and K-rasLAC57Bl6/129/sv F1 mice with no detectable toxicity. Our findings support the potential use of deguelin in a liposomal formulation via lung-specific delivery to improve efficacy and to reduce the potential side effects of the agent.

  5. Inhibition of Autophagy by Deguelin Sensitizes Pancreatic Cancer Cells to Doxorubicin.

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    Xu, Xiao Dong; Zhao, Yan; Zhang, Min; He, Rui Zhi; Shi, Xiu Hui; Guo, Xing Jun; Shi, Cheng Jian; Peng, Feng; Wang, Min; Shen, Min; Wang, Xin; Li, Xu; Qin, Ren Yi

    2017-02-10

    Pancreatic cancer is the fourth most common cause of cancer mortality worldwide. Furthermore, patients with pancreatic cancer experience limited benefit from current chemotherapeutic approaches because of drug resistance. Therefore, an effective therapeutic strategy for patients with pancreatic cancer is urgently required. Deguelin is a natural chemopreventive drug that exerts potent antiproliferative activity in solid tumors by inducing cell death. However, the molecular mechanisms underlying this activity have not been fully elucidated. Here we show that deguelin blocks autophagy and induces apoptosis in pancreatic cancer cells in vitro. Autophagy induced by doxorubicin plays a protective role in pancreatic cancer cells, and suppressing autophagy by chloroquine or silencing autophagy protein 5 enhanced doxorubicin-induced cell death. Similarly, inhibition of autophagy by deguelin also chemosensitized pancreatic cancer cell lines to doxorubicin. These findings suggest that deguelin has potent anticancer effects against pancreatic cancer and potentiates the anti-cancer effects of doxorubicin. These findings provide evidence that combined treatment with deguelin and doxorubicin represents an effective strategy for treating pancreatic cancer.

  6. Inhibition of Autophagy by Deguelin Sensitizes Pancreatic Cancer Cells to Doxorubicin

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    Xu, Xiao Dong; Zhao, Yan; Zhang, Min; He, Rui Zhi; Shi, Xiu Hui; Guo, Xing Jun; Shi, Cheng Jian; Peng, Feng; Wang, Min; Shen, Min; Wang, Xin; Li, Xu; Qin, Ren Yi

    2017-01-01

    Pancreatic cancer is the fourth most common cause of cancer mortality worldwide. Furthermore, patients with pancreatic cancer experience limited benefit from current chemotherapeutic approaches because of drug resistance. Therefore, an effective therapeutic strategy for patients with pancreatic cancer is urgently required. Deguelin is a natural chemopreventive drug that exerts potent antiproliferative activity in solid tumors by inducing cell death. However, the molecular mechanisms underlying this activity have not been fully elucidated. Here we show that deguelin blocks autophagy and induces apoptosis in pancreatic cancer cells in vitro. Autophagy induced by doxorubicin plays a protective role in pancreatic cancer cells, and suppressing autophagy by chloroquine or silencing autophagy protein 5 enhanced doxorubicin-induced cell death. Similarly, inhibition of autophagy by deguelin also chemosensitized pancreatic cancer cell lines to doxorubicin. These findings suggest that deguelin has potent anticancer effects against pancreatic cancer and potentiates the anti-cancer effects of doxorubicin. These findings provide evidence that combined treatment with deguelin and doxorubicin represents an effective strategy for treating pancreatic cancer. PMID:28208617

  7. Deguelin action involves c-Met and EGFR signaling pathways in triple negative breast cancer cells.

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    Rajeshwari Mehta

    Full Text Available BACKGROUND: Treatment of breast cancer patients with antiestrogens and aromatase inhibitor(s or Herceptin have shown significant success in steroid receptor positive or Her-2+ breast cancers respectively. However, choice of treatments for breast cancer patients with negative status for estrogen, progesterone receptors and HER2/neu is limited. As a result, search for appropriate therapy regimen for these triple negative breast cancers (TNBC has become a major focus of investigations for many laboratories. Recently, Deguelin, a natural product isolated from African plant Mundulea sericea (Leguminossae has shown both antiproliferative actions in various cancers including breast as well as chemoprenventive activity against carcinogen induced experimental cancers. In this report we evaluated efficacy and mechanism of action of Deguelin in triple negative breast cancer cell lines. METHODS/FINDINGS: In vitro, Deguelin in a dose and time dependent manner inhibited the growth of MDA-MB-231, MDA-MB-468, BT-549 and BT-20 cells. Deguelin (2 or 4 mg/kg body weight, when injected intraperitoneally, reduced the in vivo tumor growth of MDA-MB-231 cells transplanted subcutaneously in athymic mice. Moreover it was nontoxic as evident from daily observations on mobility, food and water consumption and comparison of bodyweight and other visceral organ weights with those in control animals at the termination of the study. The western blot analyses and immunostaining studies indicated that the deguelin effects may be mediated through EGFR-PAKT/c-Met p-ERK and NF-κB by down regulating their downstream targets such as p-STAT3, c-Myc, Survivin. CONCLUSION/SIGNIFICANCE: These results suggest that Deguelin may have a significant therapeutic value for the treatment of TNBC patients.

  8. Natural products as antimitotic agents.

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    Dall'Acqua, Stefano

    2014-01-01

    Natural products still play an important role in the medicinal chemistry, especially in some therapeutic areas. As example more than 60% of currently-used anticancer agents are derives from natural sources including plants, marine organisms or micro-organism. Thus natural products (NP) are an high-impact source of new "lead compounds" or new potential therapeutic agents despite the large development of biotechnology and combinatorial chemistry in the drug discovery and development. Many examples of anticancer drugs as paclitaxel, combretastatin, bryostatin and discodermolide have shown the importance of NP in the anticancer chemotherapy through many years. Many organisms have been studied as sources of drugs namely plants, micro-organisms and marine organisms and the obtained NP can be considered a group of "privileged chemical structures" evolved in nature to interact with other organisms. For this reason NP are a good starting points for pharmaceutical research and also for library design. Tubulin and microtubules are one of the most studied targets for the search of anticancer compounds. Microtubule targeting agents (MTA) also named antimitotic agents are compounds that are able to perturb mitosis but are also able to arrest cell growing during interphase. The anticancer drugs, taxanes and vinca alkaloids have established tubulin as important target in cancer therapy. More recently the vascular disrupting agents (VDA) combretastatin analogues were studied for their antimitotics properties. This review will consider the anti mitotic NP and their potential impact in the development of new therapeutic agents.

  9. Affective Embodied Conversational Agents for Natural Interaction

    OpenAIRE

    Cerezo, Eva; Baldassarri, Sandra; Hupont, Isabelle; Seron, Francisco J.

    2008-01-01

    This chapter presents a completely automated real-time character-based interface, where a scriptable affective humanoid 3D agent interacts with the user. Special care has been taken in making it possible multimodal natural user-agent interaction: communication is accomplished via text, image and voice (natural language). Our embodied agents are equipped with an emotional state which can be modified throughout the conversation with the user, and depends on the emotional state detected from the...

  10. Natural anti-obesity agents

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    Gamal A. Mohamed

    2014-12-01

    Full Text Available Obesity is a complex disease caused by the interaction of a myriad of genetic, dietary, lifestyle, and environmental factors, which favors a chronic positive energy balance, and leads to increased body fat mass. The incidence of obesity is rising at an alarming rate and is becoming a major public health concern with incalculable social costs. Indeed, obesity facilitates the development of metabolic disorders such as diabetes, hypertension, and cardiovascular diseases in addition to chronic diseases such as stroke, osteoarthritis, sleep apnea, some cancers, and inflammation-based pathologies. Recent researches demonstrated the potential of natural products to counteract obesity. Multiple-natural product combinations may result in a synergistic activity that increases their bioavailability and action on multiple molecular targets, offering advantages over chemical treatments. In this review, we discuss the anti-obesity potential of natural products and analyze their mechanisms.

  11. Marine natural products as prototype agrochemical agents.

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    Peng, Jiangnan; Shen, Xiaoyu; El Sayed, Khalid A; Dunbar, D Charles; Perry, Tony L; Wilkins, Scott P; Hamann, Mark T; Bobzin, Steve; Huesing, Joseph; Camp, Robin; Prinsen, Mike; Krupa, Dan; Wideman, Margaret A

    2003-04-09

    In the interest of identifying new leads that could serve as prototype agrochemical agents, 18 structurally diverse marine-derived compounds were examined for insecticidal, herbicidal, and fungicidal activities. Several new classes of compounds have been shown to be insecticidal, herbicidal, and fungicidal, which suggests that marine natural products represent an intriguing source for the discovery of new agrochemical agents.

  12. Marine Natural Products as Prototype Agrochemical Agents

    OpenAIRE

    Peng, Jiangnan; Shen, Xiaoyu; Khalid A. El Sayed; Dunbar, D. C Harles; Perry, Tony L.; Wilkins, Scott P.; Hamann, Mark T.; Bobzin, Steve; Huesing, Joseph; Camp, Robin; Prinsen, Mike; Krupa, Dan; Wideman, Margaret A.

    2003-01-01

    In the interest of identifying new leads that could serve as prototype agrochemical agents, 18 structurally diverse marine-derived compounds were examined for insecticidal, herbicidal, and fungicidal activities. Several new classes of compounds have been shown to be insecticidal, herbicidal, and fungicidal, which suggests that marine natural products represent an intriguing source for the discovery of new agrochemical agents.

  13. NATURAL AGENTS FOR INFLAMMATORY BOWEL DISEASE

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    Darji Vinay Chhanalal

    2011-02-01

    Full Text Available Inflammatory bowel disease (IBD is a chronic inflammatory disease of gastrointestinal tract. It comprises the two conditions, Crohn’s disease and ulcerative colitis, characterized by chronic recurrent ulceration of the bowel. Conventional drugs for colitis treatment include aminosalicylate, corticosteroids,antibiotics & immunomodulators. 5- Amino salicylic acid having side effects in 30% of the patients. Systemic corticosteroids producing incidence of complication is 4.3%. Antibiotic therapy is beneficial in 70% of the patients & Immunomodulators having 50 to 70% beneficial effects. This report shows that there is no any appropriate treatment available to treat IBD without side effects. A natural agent with reduced or no toxicity is therefore essential. In nature there are so many types of natural agents which are used as protective agents in IBD. This article emphasizes many natural products obtained from plant & other sources, which possess potent activity against experimentally induced IBD.

  14. The agents of natural genome editing

    Institute of Scientific and Technical Information of China (English)

    Guenther Witzany

    2011-01-01

    The DNA serves as a stable information storage medium and every protein which is needed by the cell is produced from this blueprint via an RNA intermediate code. More recently it was found that an abundance of various RNA elements cooperate in a variety of steps and substeps as regulatory and catalytic units with multiple competencies to act on RNA transcripts. Natural genome editing on one side is the competent agent*driven generation and integration of meaningful DNA nucleotide sequences into pre-existing genomic content arrangements, and the ability to (re-)combine and (re-)regulate them according to context-dependent (i.e. adaptational) purposes of the host organism. Natural genome editing on the other side designates the integration of all RNA activities acting on RNA transcripts without altering DNA-encoded genes. If we take the genetic code seriously as a natural code, there must be agents that are competent to act on this code because no natural code codes itself as no natural language speaks itself. As code editing agents,viral and subviral agents have been suggested because there are several indicators that demonstrate viruses competent in both RNA and DNA natural genome editing.

  15. Deguelin attenuates reperfusion injury and improves outcome after orthotopic lung transplantation in the rat.

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    Patrick Paulus

    Full Text Available The main goal of adequate organ preservation is to avoid further cellular metabolism during the phase of ischemia. However, modern preservation solutions do rarely achieve this target. In donor organs hypoxia and ischemia induce a broad spectrum of pathologic molecular mechanisms favoring primary graft dysfunction (PGD after transplantation. Increased hypoxia-induced transcriptional activity leads to increased vascular permeability which in turn is the soil of a reperfusion edema and the enhancement of a pro-inflammatory response in the graft after reperfusion. We hypothesize that inhibition of the respiration chain in mitochondria and thus inhibition of the hypoxia induced mechanisms might reduce reperfusion edema and consecutively improve survival in vivo. In this study we demonstrate that the rotenoid Deguelin reduces the expression of hypoxia induced target genes, and especially VEGF-A, dose-dependently in hypoxic human lung derived cells. Furthermore, Deguelin significantly suppresses the mRNA expression of the HIF target genes VEGF-A, the pro-inflammatory CXCR4 and ICAM-1 in ischemic lungs vs. control lungs. After lung transplantation, the VEGF-A induced reperfusion-edema is significantly lower in Deguelin-treated animals than in controls. Deguelin-treated rats exhibit a significantly increased survival-rate after transplantation. Additionally, a downregulation of the pro-inflammatory molecules ICAM-1 and CXCR4 and an increase in the recruitment of immunomodulatory monocytes (CD163+ and CD68+ to the transplanted organ involving the IL4 pathway was observed. Therefore, we conclude that ischemic periods preceding reperfusion are mainly responsible for the increased vascular permeability via upregulation of VEGF. Together with this, the resulting endothelial dysfunction also enhances inflammation and consequently lung dysfunction. Deguelin significantly decreases a VEGF-A induced reperfusion edema, induces the recruitment of immunomodulatory

  16. The Hunt for Natural Skin Whitening Agents

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    Stan Pavel

    2009-12-01

    Full Text Available Skin whitening products are commercially available for cosmetic purposes in order to obtain a lighter skin appearance. They are also utilized for clinical treatment of pigmentary disorders such as melasma or postinflammatory hyperpigmentation. Whitening agents act at various levels of melanin production in the skin. Many of them are known as competitive inhibitors of tyrosinase, the key enzyme in melanogenesis. Others inhibit the maturation of this enzyme or the transport of pigment granules (melanosomes from melanocytes to surrounding keratinocytes. In this review we present an overview of (natural whitening products that may decrease skin pigmentation by their interference with the pigmentary processes.

  17. NICA: Natural Interaction with a Caring Agent

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    de Carolis, Berardina; Mazzotta, Irene; Novielli, Nicole

    Ambient Intelligence solutions may provide a great opportunity for elderly people to live longer at home. Assistance and care are delegated to the intelligence embedded in the environment. However, besides considering service-oriented response to the user needs, the assistance has to take into account the establishment of social relations. We propose the use of a robot NICA (as the name of the project Natural Interaction with a Caring Agent) acting as a caring assistant that provides a social interface with the smart home services. In this paper, we introduce the general architecture of the robot's "mind" and then we focus on the need to properly react to affective and socially oriented situations.

  18. Learning by Communicating in Natural Language with Conversational Agents

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    Graesser, Arthur; Li, Haiying; Forsyth, Carol

    2014-01-01

    Learning is facilitated by conversational interactions both with human tutors and with computer agents that simulate human tutoring and ideal pedagogical strategies. In this article, we describe some intelligent tutoring systems (e.g., AutoTutor) in which agents interact with students in natural language while being sensitive to their cognitive…

  19. Formulation and evaluation of ciprofloxacin suspension using natural suspending agent

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    Sameer J. Nadaf

    2014-03-01

    Full Text Available The aim of the present study is to formulate and evaluate ciprofloxacin suspension using natural suspending agent. Trigonella foenum graecum Mucilage was used as natural suspending agent. Total 9 batches (C1-C9 were prepared by varying concentration of suspending agent from 0.5-2% and propylene glycol. Prepared suspension were evaluated by studying different parameters like pH, sedimentation volume, redispersibility, Flow rate (F, viscosity, degree of flocculation, effect of temperature etc. batches C6, C7 and C8 were found to be stable throughout the study. As the concentration of suspending agent increased viscosity also get increased which reduces the sedimentation and contributes to the stability of suspension. Increase in viscosity avoids the particle aggregation so particles remain in a flocculated state.

  20. Significance and nature of bystander responses induced by various agents.

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    Verma, Neha; Tiku, Ashu Bhan

    2017-07-01

    Bystander effects in a biological system are the responses shown by non-targeted neighbouring cells/tissues/organisms. These responses are triggered by factors released from targeted cells when exposed to a stress inducing agent. The biological response to stress inducing agents is complex, owing to the diversity of mechanisms and pathways activated in directly targeted and bystander cells. These responses are highly variable and can be either beneficial or hazardous depending on the cell lines tested, dose of agent used, experimental end points and time course selected. Recently non-targeted cells have even been reported to rescue the directly exposed cells by releasing protective signals that might be induced by non-targeted bystander responses. The nature of bystander signal/s is not yet clear. However, there are evidences suggesting involvement of ROS, RNS, protein factors and even DNA molecules leading to the activation of a number of signaling pathways. These can act independently or in a cascade, to induce events leading to changes in gene expression patterns that could elicit detrimental or beneficial effects. Many review articles on radiation induced bystander responses have been published. However, to the best of our knowledge, a comprehensive review on bystander responses induced by other genotoxic chemicals and stress inducing agents has not been published so far. Therefore, the aim of the present review is to give an overview of the literature on different aspects of bystander responses: agents that induce these responses, factors that can modulate bystander responses and the mechanisms involved. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Embryotoxic effect of deguelin in zebrafish%鱼藤素对斑马鱼胚胎毒性的作用

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    李文浩; 吴新荣

    2012-01-01

    BACKGROUND:The establishment of antitumor drug deguelin model provides basis for the in vivo experiment.OBJECTIVE: To investigate the influence of different concentrations of deguelin on zebrafish embryonic development.METHODS: The zebrafish embryos were treated with different concentrations of deguelin. The changes of the phenotype wereobserved at 48 and 72 hours after postfertilization, and the hatching rate was counted at 72 hours after postfertilization.RESULTS AND CONCLUSION: The development of embryo was remained under 0.1 μmol/L concentration of deguelin. Thedevelopment of embryo was delayed at 0.2 μmol/L concentration of deguelin. 0.3 μmol/L concentration of deguelin could inhibit thedevelopment of embryo and cause death of the embryo. These results show that high concentration of deguelin leads toembryonic lethality, while low concentration of deguelin delays the embryonic development.%背景:以模式生物斑马鱼构建生物模型,易于开展活体实验.目的:探讨了不同鱼藤素浓度对斑马鱼胚胎发育的影响.方法:不同鱼藤素浓度作用于斑马鱼胚胎,分别在受精后48,72 h观测其表型变化,受精后72 h统计其胚胎孵化率.结果与结论:鱼藤素在0.1 μmol/L浓度以下对斑马鱼胚胎发育无影响,0.2 μmol/L浓度延缓斑马鱼胚胎发育,0.3 μmol/L浓度以上抑制了斑马鱼胚胎发育,使胚胎致死.结果表明,鱼藤素高浓度使胚胎致死,低浓度延缓胚胎发育.

  2. Discovery of Anticancer Agents of Diverse Natural Origin.

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    Kinghorn, A Douglas; DE Blanco, Esperanza J Carcache; Lucas, David M; Rakotondraibe, H Liva; Orjala, Jimmy; Soejarto, D Doel; Oberlies, Nicholas H; Pearce, Cedric J; Wani, Mansukh C; Stockwell, Brent R; Burdette, Joanna E; Swanson, Steven M; Fuchs, James R; Phelps, Mitchell A; Xu, Lihui; Zhang, Xiaoli; Shen, Young Yongchun

    2016-11-01

    Recent progress is described in an ongoing collaborative multidisciplinary research project directed towards the purification, structural characterization, chemical modification, and biological evaluation of new potential natural product anticancer agents obtained from a diverse group of organisms, comprising tropical plants, aquatic and terrestrial cyanobacteria, and filamentous fungi. Information is provided on how these organisms are collected and processed. The types of bioassays are indicated in which initial extracts, chromatographic fractions, and purified isolated compounds of these acquisitions are tested. Several promising biologically active lead compounds from each major organism class investigated are described, and these may be seen to be representative of a very wide chemical diversity.

  3. Alkaloids Isolated from Natural Herbs as the Anticancer Agents

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    Jin-Jian Lu

    2012-01-01

    Full Text Available Alkaloids are important chemical compounds that serve as a rich reservoir for drug discovery. Several alkaloids isolated from natural herbs exhibit antiproliferation and antimetastasis effects on various types of cancers both in vitro and in vivo. Alkaloids, such as camptothecin and vinblastine, have already been successfully developed into anticancer drugs. This paper focuses on the naturally derived alkaloids with prospective anticancer properties, such as berberine, evodiamine, matrine, piperine, sanguinarine, and tetrandrine, and summarizes the mechanisms of action of these compounds. Based on the information in the literature that is summarized in this paper, the use of alkaloids as anticancer agents is very promising, but more research and clinical trials are necessary before final recommendations on specific alkaloids can be made.

  4. The natural chemopreventive agent sulforaphane inhibits STAT5 activity.

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    Sophia Pinz

    Full Text Available Signal transducer and activator of transcription STAT5 is an essential mediator of cytokine, growth factor and hormone signaling. While its activity is tightly regulated in normal cells, its constitutive activation directly contributes to oncogenesis and is associated to a number of hematological and solid tumor cancers. We previously showed that deacetylase inhibitors can inhibit STAT5 transcriptional activity. We now investigated whether the dietary chemopreventive agent sulforaphane, known for its activity as deacetylase inhibitor, might also inhibit STAT5 activity and thus could act as a chemopreventive agent in STAT5-associated cancers. We describe here sulforaphane (SFN as a novel STAT5 inhibitor. We showed that SFN, like the deacetylase inhibitor trichostatin A (TSA, can inhibit expression of STAT5 target genes in the B cell line Ba/F3, as well as in its transformed counterpart Ba/F3-1*6 and in the human leukemic cell line K562 both of which express a constitutively active form of STAT5. Similarly to TSA, SFN does not alter STAT5 initial activation by phosphorylation or binding to the promoter of specific target genes, in favor of a downstream transcriptional inhibitory effect. Chromatin immunoprecipitation assays revealed that, in contrast to TSA however, SFN only partially impaired the recruitment of RNA polymerase II at STAT5 target genes and did not alter histone H3 and H4 acetylation, suggesting an inhibitory mechanism distinct from that of TSA. Altogether, our data revealed that the natural compound sulforaphane can inhibit STAT5 downstream activity, and as such represents an attractive cancer chemoprotective agent targeting the STAT5 signaling pathway.

  5. Evaluation of natural anthracene-derived compounds as antimitotic agents.

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    Badria, Farid A; Ibrahim, Ahmed S

    2013-04-01

    Plants that contain anthracene-derived compounds such as anthraquinones have been reported to act as anticancer besides their use for millennia to treat constipation, but the mechanism of action is still unfolding. Therefore we pursue this study to explore a new horizon in the anticancer property of these agents with relevance to mitotic arrest. To achieve this goal, the antimitotic activity of a series of naturally occurring anthracene-derived anthraquinones including anthrone, alizarin (1,2-dihydroxyanthraquinone), quinizarin (1,4-dihydroxyanthraquinone), rhein (4,5-dihydroxyanthraquinone-2-carboxylic acid), emodin (1,6,8-trihydroxy-3-methylanthraquinone), and aloe emodin (1,8-dihydroxy-3-hydroxymethylanthraquinone) were evaluated using Allium cepa root tips. Initial results revealed that the mitosis was inhibited after 3, 6, and 24 h, respectively, of incubation with 500, 250, and 125 ppm of each compound in a dose-dependent manner. Furthermore, alizarin at 500 ppm was proved to be the most active compound to arrest the mitosis after 24 h followed by emodin, aloe emodin, rhein, and finally quinizarin. Interestingly, this inhibition of mitosis was irreversible in root tips incubated with each compound at concentration of 500 ppm but not with 250 ppm or 125 ppm, where the roots regained their normal mitotic activity after 96 h post-incubation in water. This re-evaluation of an old remedy suggests that several bioactive anthraquinones possess promising anti-mitotic activity that may have the potential to be lead compounds for the development of a new class of multifaceted natural anticancer/antimitotic agents.

  6. IN VITRO CHARACTERIZATION OF NATURAL MUCOADHESIVE AGENT ISOLATED FROM OCIMUM AMERICANUM SEED

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    Avinash B. Gangurde et al

    2012-09-01

    Full Text Available Aim of present investigation was to isolate natural mucoadhesive agent from Ocimum americanum seeds and characterize through in vitro mucoadhesion methods, FTIR and DSC studies. Mucoadhesion force of isolated natural mucoadhesive agents and synthetic polymer Carbopol 934P was determined using in vitro mucoadhesion methods viz. Wihelmy’s method, falling sphere method and modified physical balance method. The research study reveals that the natural mucoadhesive agent isolated from Ocimum americanum seed was shown promising mucoadhesion strength. The formation of hydrogen bond by natural mucoadhesive agent with mucosa was confirmed by FTIR spectra showing carboxyl and hydroxyl groups. Natural mucoadhesive agent may be useful to formulate mucoadhesive drug delivery systems as it bears excellent mucoadhesion property and advantageous over synthetic polymers for less toxicity, biocompatibility, biodegradability and cost.

  7. Evolutionary autonomous agents and the nature of apraxia

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    Jin Frank

    2005-01-01

    Full Text Available Abstract Background Evolutionary autonomous agents are robots or robot simulations whose controller is a dynamical neural network and whose evolution occurs autonomously under the guidance of a fitness function without the detailed or explicit direction of an external programmer. They are embodied agents with a simple neural network controller and as such they provide the optimal forum by which sensorimotor interactions in a specified environment can be studied without the computational assumptions inherent in standard neuroscience. Methods Evolutionary autonomous agents were evolved that were able to perform identical movements under two different contexts, one which represented an automatic movement and one which had a symbolic context. In an attempt to model the automatic-voluntary dissociation frequently seen in ideomotor apraxia, lesions were introduced into the neural network controllers resulting in a behavioral dissociation with loss of the ability to perform the movement which had a symbolic context and preservation of the simpler, automatic movement. Results Analysis of the changes in the hierarchical organization of the networks in the apractic EAAs demonstrated consistent changes in the network dynamics across all agents with loss of longer duration time scales in the network dynamics. Conclusion The concepts of determinate motor programs and perceptual representations that are implicit in the present day understanding of ideomotor apraxia are assumptions inherent in the computational understanding of brain function. The strength of the present study using EAAs to model one aspect of ideomotor apraxia is the absence of these assumptions and a grounding of all sensorimotor interactions in an embodied, autonomous agent. The consistency of the hierarchical changes in the network dynamics across all apractic agents demonstrates that this technique is tenable and will be a valuable adjunct to a computational formalism in the understanding

  8. Anti-Enterovirus 71 Agents of Natural Products

    Directory of Open Access Journals (Sweden)

    Liyan Wang

    2015-09-01

    Full Text Available This review, with 42 references, presents the fascinating area of anti-enterovirus 71 natural products over the last three decades for the first time. It covers literature published from 2005–2015 and refers to compounds isolated from biogenic sources. In total, 58 naturally-occurring anti-EV71 compounds are recorded.

  9. Natural Organohalogens: A New Frontier for Medicinal Agents?

    Science.gov (United States)

    Gribble, Gordon W.

    2004-10-01

    More than 4000 naturally occurring organohalogen compounds are known. These include a relatively small number of abiogenic organohalogens from volcanoes, forest fires, geothermal processes, and meteorites, and a very large number of biogenic organohalogens produced by myriad living organisms as part of their chemical makeup that serve as hormones, pheromones, repellents, and natural pesticides. From the chemically simple methyl chloride, methyl bromide, and chloroform to the structurally complex vancomycin, pyrroindomycin, and bastadins, the diversity of these organohalogens is unsurpassed among natural products. Most natural organohalogens contain chlorine (2300) or bromine (2100), but a significant number contain iodine (120) or fluorine (30). Several hundred marine natural products contain both chlorine and bromine. The present article focuses on newly discovered biogenic organohalogens, with an emphasis on those biologically active examples from marine organisms, bacteria, terrestrial plants, and higher life forms including humans.

  10. Natural Organohalogens: A New Frontier for Medicinal Agents?

    Science.gov (United States)

    Gribble, Gordon W.

    2004-01-01

    Newly discovered biogenic organo halogens with an emphasis on the biologically active examples from marine organisms, bacteria, terrestrial plants and higher life forms, including humans, are focused. Organohalogen compounds represent a valuable and expanding class of natural products, in many cases boasting exceptional biological activity.

  11. Quercetin as natural stabilizing agent for bio-polymer

    Energy Technology Data Exchange (ETDEWEB)

    Morici, Elisabetta [Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica, Università di Palermo, 90128 Palermo (Italy); Arrigo, Rossella; Dintcheva, Nadka Tzankova [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, 90128 Palermo (Italy)

    2014-05-15

    The introduction of antioxidants in polymers is the main way to prevent or delay the degradation process. In particular natural antioxidants receive attention in the food industry also because of their presumed safety. In this work bio-polymers, i.e. a commercial starch-based polymer (Mater-Bi®) and a bio-polyester (PLA), and a bio-polyether (PEO) were additivated with quercetin, a natural flavonoid antioxidants, in order to formulate bio-based films for ecosustainable packaging and outdoor applications. The photo-oxidation behavior of unstabilized and quercetin stabilized films was analyzed and compared with the behavior of films additivated with a commercial synthetic light stabilizer. The quercetin is able to slow down the photo-degradation rate of all bio-polymeric films investigated in similar way to the synthetic stabilizer.

  12. Quercetin as natural stabilizing agent for bio-polymer

    Science.gov (United States)

    Morici, Elisabetta; Arrigo, Rossella; Dintcheva, Nadka Tzankova

    2014-05-01

    The introduction of antioxidants in polymers is the main way to prevent or delay the degradation process. In particular natural antioxidants receive attention in the food industry also because of their presumed safety. In this work bio-polymers, i.e. a commercial starch-based polymer (Mater-Bi®) and a bio-polyester (PLA), and a bio-polyether (PEO) were additivated with quercetin, a natural flavonoid antioxidants, in order to formulate bio-based films for ecosustainable packaging and outdoor applications. The photo-oxidation behavior of unstabilized and quercetin stabilized films was analyzed and compared with the behavior of films additivated with a commercial synthetic light stabilizer. The quercetin is able to slow down the photo-degradation rate of all bio-polymeric films investigated in similar way to the synthetic stabilizer.

  13. The Physical Modification of a Natural Rubber-Polypropylene Thermoplastic Elastomer Blend by Azobisformamide Blowing Agent

    OpenAIRE

    Safia Merabet; Farid Riahi; Abdelmalek Douibi

    2012-01-01

    The decomposition of azobisformamide (ABFA) blowing agent and its expansion in a soft grade of thermoplastic natural rubber composed of a 70/30 natural rubber (NR)/polypropylene (PP) was monitored using a Haake plasticorder. The aim of the study was to evaluate the effect of different concentrations of the blowing agent and to investigate its eventual interactions with a sulfur-based curing system that was used for the dynamic vulcanization. The plastograms allowed to detect variations in the...

  14. Hallucinogens and dissociative agents naturally growing in the United States.

    Science.gov (United States)

    Halpern, John H

    2004-05-01

    It is usually believed that drugs of abuse are smuggled into the United States or are clandestinely produced for illicit distribution. Less well known is that many hallucinogens and dissociative agents can be obtained from plants and fungi growing wild or in gardens. Some of these botanical sources can be located throughout the United States; others have a more narrow distribution. This article reviews plants containing N,N-dimethyltryptamine, reversible type A monoamine oxidase inhibitors (MAOI), lysergic acid amide, the anticholinergic drugs atropine and scopolamine, or the diterpene salvinorin-A (Salvia divinorum). Also reviewed are mescaline-containing cacti, psilocybin/psilocin-containing mushrooms, and the Amanita muscaria and Amanita pantherina mushrooms that contain muscimol and ibotenic acid. Dangerous misidentification is most common with the mushrooms, but even a novice forager can quickly learn how to properly identify and prepare for ingestion many of these plants. Moreover, through the ever-expanding dissemination of information via the Internet, this knowledge is being obtained and acted upon by more and more individuals. This general overview includes information on the geographical range, drug content, preparation, intoxication, and the special health risks associated with some of these plants. Information is also offered on the unique issue of when bona fide religions use such plants as sacraments in the United States. In addition to the Native American Church's (NAC) longstanding right to peyote, two religions of Brazilian origin, the Santo Daime and the Uniao do Vegetal (UDV), are seeking legal protection in the United States for their use of sacramental dimethyltryptamine-containing "ayahuasca."

  15. Pectin functionalized with natural fatty acids as antimicrobial agent.

    Science.gov (United States)

    Calce, Enrica; Mignogna, Eleonora; Bugatti, Valeria; Galdiero, Massimiliano; Vittoria, Vittoria; De Luca, Stefania

    2014-07-01

    Several pectin derivatives were prepared by chemical modifications of the polysaccharide with natural fatty acids. The obtained biodegradable pectin-based materials, pectin-linoleate, pectin-oleate and pectin-palmitate, were investigated for their antimicrobial activity against several bacterial strains, Staphylococcus aureus and Escherichia coli. Good results were obtained for pectin-oleate and pectin-linoleate, which inhibit the growth of the selected microorganisms by 50-70%. They exert the better antimicrobial activity against S. aureus. Subsequently, the pectin-oleate and the pectin-linoleate samples were coated on polyethylene films and were assessed for their capacity to capture the oxygen molecules, reducing its penetration into the polymeric support. These results confirmed a possible application of the new materials in the field of active food packaging.

  16. Evaluation of natural products as potential agrochemical agents with insecticide, fungicide and herbicide activities

    CSIR Research Space (South Africa)

    Dumontet, V

    2012-07-01

    Full Text Available The International Congress on Natural Products Research, New York City, 28 July - 1 August 2012 Evaluation of natural products as potential agrochemical agents with insecticide, fungicide and herbicide activities V Dumontet 1, M Litaudon 1, F Olivon 1, C...

  17. Multipotent natural agents to combat Alzheimer's disease. Functional spectrum and structural features

    Institute of Scientific and Technical Information of China (English)

    Hong-fang JI; Hong-yu ZHANG

    2008-01-01

    With the accelerated aging of human society, Alzheimer's disease (AD) is becoming one of the biggest threats to human health. Since multiple pathogenetic factors are implicated in the disease, the current hitting-one-target therapeutic strategy has proved inefficient to AD. As a result, finding multipotent agents that aim at multiple targets is attracting more and more attention. Although multifunc-tional anti-AD agents can be created by incorporating two or more pharmacophores in one scaffold, naturally occurring multipotent agents also attracted much attention. In this review, we first describe the functions of some typical naturally originated multipotent anti-AD compounds, then summarize their structural fea-tures and reveal that phenolics with certain flexibility predominate in these agents, which are of significance to find novel multipotent drugs to combat AD and other neurodegenerative diseases as well.

  18. Handling uncertainty of resource division in multi agent system using game against nature

    Directory of Open Access Journals (Sweden)

    Skrzypczyk Krzysztof

    2014-09-01

    Full Text Available This paper addresses the problem of resource division for robotic agents in the framework of Multi-Agent System. Knowledge of the environment represented in the system is uncertain, incomplete and distributed among the individual agents that have both limited sensing and communication abilities. The pick-up-and-collection problem is considered in order to illustrate the idea presented. In this paper a framework for cooperative task assignment to individual agents is discussed. The process of negotiating access to common resources by intercommunicating agents is modeled and solved as a game against Nature. The working of the proposed system was verified by multiple simulations. Selected, exemplary simulations are presented in the paper to illustrate the approach discussed

  19. Nature as a network of morphological infocomputational processes for cognitive agents

    Science.gov (United States)

    Dodig-Crnkovic, Gordana

    2017-01-01

    This paper presents a view of nature as a network of infocomputational agents organized in a dynamical hierarchy of levels. It provides a framework for unification of currently disparate understandings of natural, formal, technical, behavioral and social phenomena based on information as a structure, differences in one system that cause the differences in another system, and computation as its dynamics, i.e. physical process of morphological change in the informational structure. We address some of the frequent misunderstandings regarding the natural/morphological computational models and their relationships to physical systems, especially cognitive systems such as living beings. Natural morphological infocomputation as a conceptual framework necessitates generalization of models of computation beyond the traditional Turing machine model presenting symbol manipulation, and requires agent-based concurrent resource-sensitive models of computation in order to be able to cover the whole range of phenomena from physics to cognition. The central role of agency, particularly material vs. cognitive agency is highlighted.

  20. Natural Products as Tools for Neuroscience: Discovery and Development of Novel Agents to Treat Drug Abuse⊥

    OpenAIRE

    2009-01-01

    Much of what we know about the neurosciences is the direct result of studying psychoactive natural products. Unfortunately, there are many gaps in our understanding of the basic biological processes that contribute to the etiology of many CNS disorders. The investigation of psychoactive natural products offers an excellent approach to identify novel agents to treat CNS disorders and to find new chemical tools to better elucidate their biological mechanisms. This review will detail recent prog...

  1. Natural Products as a Vital Source for the Discovery of Cancer Chemotherapeutic and Chemopreventive Agents.

    Science.gov (United States)

    Cragg, Gordon M; Pezzuto, John M

    2016-01-01

    Throughout history, natural products have played a dominant role in the treatment of human ailments. For example, the legendary discovery of penicillin transformed global existence. Presently, natural products comprise a large portion of current-day pharmaceutical agents, most notably in the area of cancer therapy. Examples include Taxol, vinblastine, and camptothecin. These structurally unique agents function by novel mechanisms of action; isolation from natural sources is the only plausible method that could have led to their discovery. In addition to terrestrial plants as sources for starting materials, the marine environment (e.g., ecteinascidin 743, halichondrin B, and dolastatins), microbes (e.g., bleomycin, doxorubicin, and staurosporin), and slime molds (e.g., epothilone B) have yielded remarkable cancer chemotherapeutic agents. Irrespective of these advances, cancer remains a leading cause of death worldwide. Undoubtedly, the prevention of human cancer is highly preferable to treatment. Cancer chemoprevention, the use of vaccines or pharmaceutical agents to inhibit, retard, or reverse the process of carcinogenesis, is another important approach for easing this formidable public health burden. Similar to cancer chemotherapeutic agents, natural products play an important role in this field. There are many examples, including dietary phytochemicals such as sulforaphane and phenethyl isothiocyanate (cruciferous vegetables) and resveratrol (grapes and grape products). Overall, natural product research is a powerful approach for discovering biologically active compounds with unique structures and mechanisms of action. Given the unfathomable diversity of nature, it is reasonable to suggest that chemical leads can be generated that are capable of interacting with most or possibly all therapeutic targets. © 2015 S. Karger AG, Basel.

  2. All Natural and Clean-Label Preservatives and Antimicrobial Agents Used during Poultry Processing and Packaging.

    Science.gov (United States)

    Grant, Ar'quette; Parveen, Salina

    2017-04-01

    The poultry industry is faced with compounding pressures of maintaining product safety and wholesomeness while keeping up with consumer trends of all-natural foods and label accuracy. Consumers are increasingly demanding that their foods be minimally processed and contain compounds that are easily read and recognized, i.e., products must be clean labeled. The purpose of this review is to briefly describe several natural antimicrobial agents that can be incorporated into poultry processing. These compounds and their essential oils were included in this mini-review because they are generally recognized as safe by the U.S. Food and Drug Administration and are considered clean label: thyme extract, rosemary extract, garlic, and oregano. This list of natural antimicrobial agents by no means includes all of the options available to poultry processors. Rather, this review provides a brief glance at the potential these natural antimicrobial agents have in terms of reduced pathogenicity, increased shelf stability, and sensory acceptability through direct product application or as part of the product packaging.

  3. Discovery and development of natural product oridonin-inspired anticancer agents.

    Science.gov (United States)

    Ding, Ye; Ding, Chunyong; Ye, Na; Liu, Zhiqing; Wold, Eric A; Chen, Haiying; Wild, Christopher; Shen, Qiang; Zhou, Jia

    2016-10-21

    Natural products have historically been, and continue to be, an invaluable source for the discovery of various therapeutic agents. Oridonin, a natural diterpenoid widely applied in traditional Chinese medicines, exhibits a broad range of biological effects including anticancer and anti-inflammatory activities. To further improve its potency, aqueous solubility and bioavailability, the oridonin template serves as an exciting platform for drug discovery to yield better candidates with unique targets and enhanced drug properties. A number of oridonin derivatives (e.g. HAO472) have been designed and synthesized, and have contributed to substantial progress in the identification of new agents and relevant molecular mechanistic studies toward the treatment of human cancers and other diseases. This review summarizes the recent advances in medicinal chemistry on the explorations of novel oridonin analogues as potential anticancer therapeutics, and provides a detailed discussion of future directions for the development and progression of this class of molecules into the clinic.

  4. Current Status of Natural Products from Plants as Anti-herpes Simplex Virus 1 Agents

    Institute of Scientific and Technical Information of China (English)

    Yang-fei XIANG; Ying PEI; Yi-fei WANG

    2008-01-01

    Nucleoside analogues have been the mainstay of clinical treatment of herpes simplex virus 1 (HSV-1) infections since their development. However, the emergence of drug resistant strains has underlined the urgency of the discovery of novel anti-HSV-1 drugs. Natural products, which provided many novel drug leads, are known to be an important source of anti-HSV-1 agents. Herein, we present an overview of natural products with anti-HSV-1 activities isolated from a variety of plants reported in recent years. Several different compounds, mainly belonging to the three groups of polysaccharides, polyphenols and terpenes, showed antiviral effects against HSV-1, indicating their potential to be promising anti-HSV-1 agents.

  5. Evolution of natural agents: preservation, advance, and emergence of functional information.

    Science.gov (United States)

    Sharov, Alexei A

    2016-04-01

    Biological evolution is often viewed narrowly as a change of morphology or allele frequency in a sequence of generations. Here I pursue an alternative informational concept of evolution, as preservation, advance, and emergence of functional information in natural agents. Functional information is a network of signs (e.g., memory, transient messengers, and external signs) that are used by agents to preserve and regulate their functions. Functional information is preserved in evolution via complex interplay of copying and construction processes: the digital components are copied, whereas interpreting subagents together with scaffolds, tools, and resources, are constructed. Some of these processes are simple and invariant, whereas others are complex and contextual. Advance of functional information includes improvement and modification of already existing functions. Although the genome information may change passively and randomly, the interpretation is active and guided by the logic of agent behavior and embryonic development. Emergence of new functions is based on the reinterpretation of already existing information, when old tools, resources, and control algorithms are adopted for novel functions. Evolution of functional information progressed from protosemiosis, where signs correspond directly to actions, to eusemiosis, where agents associate signs with objects. Language is the most advanced form of eusemiosis, where the knowledge of objects and models is communicated between agents.

  6. Comparative analysis of using natural and radiogenic lead as heat-transfer agent in fast reactors

    Science.gov (United States)

    Laas, R. A.; Gizbrekht, R. V.; Komarov, P. A.; Nesterov, V. N.

    2016-06-01

    Fast reactors with lead coolant have several advantages over analogues. Performance can be further improved by replacement of natural composition lead with radiogenic one. Thus, two main issues need to be addressed: induced radioactivity in coolant and efficient neutron multiplication factor in the core will be changed and need to be estimated. To address these issues analysis of the scheme of the nuclear transformations in the lead heat-transfer agent in the process of radiation was carried out. Induced radioactivity of radiogenic and natural lead has been studied. It is shown that replacement of lead affects multiplication factor in a certain way. Application of radiogenic lead can significantly affect reactor operation.

  7. Recent Advances in the Development of Antineoplastic Agents Derived from Natural Products.

    Science.gov (United States)

    Trendowski, Matthew

    2015-11-01

    Through years of evolutionary selection pressures, organisms have developed potent toxins that coincidentally have marked antineoplastic activity. These natural products have been vital for the development of multiagent treatment regimens currently employed in cancer chemotherapy, and are used in the treatment of a variety of malignancies. Therefore, this review catalogs recent advances in natural product-based drug discovery via the examination of mechanisms of action and available clinical data to highlight the utility of these novel compounds in the burgeoning age of precision medicine. The review also highlights the recent development of antibody-drug conjugates and other immunotoxins, which are capable of delivering highly cytotoxic agents previously deemed too toxic to elicit therapeutic benefit preferentially to neoplastic cells. Finally, the review examines natural products not currently used in the clinic that have novel mechanisms of action, and may serve to supplement current chemotherapeutic protocols.

  8. Towards identifying novel anti-Eimeria agents: trace elements, vitamins, and plant-based natural products.

    Science.gov (United States)

    Wunderlich, Frank; Al-Quraishy, Saleh; Steinbrenner, Holger; Sies, Helmut; Dkhil, Mohamed A

    2014-10-01

    Eimeriosis, a widespread infectious disease of livestock, is caused by coccidian protozoans of the genus Eimeria. These obligate intracellular parasites strike the digestive tract of their hosts and give rise to enormous economic losses, particularly in poultry, ruminants including cattle, and rabbit farming. Vaccination, though a rational prophylactic measure, has not yet been as successful as initially thought. Numerous broad-spectrum anti-coccidial drugs are currently in use for treatment and prophylactic control of eimeriosis. However, increasing concerns about parasite resistance, consumer health, and environmental safety of the commercial drugs warrant efforts to search for novel agents with anti-Eimeria activity. This review summarizes current approaches to prevent and treat eimeriosis such as vaccination and commercial drugs, as well as recent attempts to use dietary antioxidants as novel anti-Eimeria agents. In particular, the trace elements selenium and zinc, the vitamins A and E, and natural products extracted from garlic, barberry, pomegranate, sweet wormwood, and other plants are discussed. Several of these novel anti-Eimeria agents exhibit a protective role against oxidative stress that occurs not only in the intestine of Eimeria-infected animals, but also in their non-parasitized tissues, in particular, in the first-pass organ liver. Currently, it appears to be promising to identify safe combinations of low-cost natural products with high anti-Eimeria efficacy for a potential use as feed supplementation in animal farming.

  9. Discovery and development of natural product-derived chemotherapeutic agents based on a medicinal chemistry approach.

    Science.gov (United States)

    Lee, Kuo-Hsiung

    2010-03-26

    Medicinal plants have long been an excellent source of pharmaceutical agents. Accordingly, the long-term objectives of the author's research program are to discover and design new chemotherapeutic agents based on plant-derived compound leads by using a medicinal chemistry approach, which is a combination of chemistry and biology. Different examples of promising bioactive natural products and their synthetic analogues, including sesquiterpene lactones, quassinoids, naphthoquinones, phenylquinolones, dithiophenediones, neo-tanshinlactone, tylophorine, suksdorfin, DCK, and DCP, will be presented with respect to their discovery and preclinical development as potential clinical trial candidates. Research approaches include bioactivity- or mechanism of action-directed isolation and characterization of active compounds, rational drug design-based modification and analogue synthesis, and structure-activity relationship and mechanism of action studies. Current clinical trial agents discovered by the Natural Products Research Laboratories, University of North Carolina, include bevirimat (dimethyl succinyl betulinic acid), which is now in phase IIb trials for treating AIDS. Bevirimat is also the first in a new class of HIV drug candidates called "maturation inhibitors". In addition, an etoposide analogue, GL-331, progressed to anticancer phase II clinical trials, and the curcumin analogue JC-9 is in phase II clinical trials for treating acne and in development for trials against prostate cancer. The discovery and development of these clinical trial candidates will also be discussed.

  10. Cordierite containing ceramic membranes from smectetic clay using natural organic wastes as pore-forming agents

    Directory of Open Access Journals (Sweden)

    W. Misrar

    2017-06-01

    Full Text Available Cordierite ceramic membranes were manufactured from natural clay, oxides and organic wastes as pore forming agents. Mixtures aforementioned materials with the pore-forming agents (up to 10 wt.% were investigated in the range 1000–1200 °C using thermal analysis, X-ray diffraction, scanning electron microscopy, mercury porosimetry and filtration tests. Physical properties (density, water absorption and bending strength were correlated to the processing factors (pore-forming agent addition, firing temperature and soaking time. The results showed that cordierite together with spinel, diopside and clinoenstatite neoformed. SEM analysis revealed heterogeneous aspects. The results of the response surface methodology showed that the variations of physical properties versus processing parameters were well described by the used polynomial model. The addition of pore forming agent and temperature were the most influential factors. Filtration tests were performed on the best performing sample. The results allowed to testify that these membranes could be used in waste water treatment.

  11. A Review of Natural Stimulant and Non‐stimulant Thermogenic Agents

    Science.gov (United States)

    Badmaev, Vladimir

    2016-01-01

    Obesity and overweight are major health issues. Exercise and calorie intake control are recognized as the primary mechanisms for addressing excess body weight. Naturally occurring thermogenic plant constituents offer adjunct means for assisting in weight management. The controlling mechanisms for thermogenesis offer many intervention points. Thermogenic agents can act through stimulation of the central nervous system with associated adverse cardiovascular effects and through metabolic mechanisms that are non‐stimulatory or a combination thereof. Examples of stimulatory thermogenic agents that will be discussed include ephedrine and caffeine. Examples of non‐stimulatory thermogenic agents include p‐synephrine (bitter orange extract), capsaicin, forskolin (Coleus root extract), and chlorogenic acid (green coffee bean extract). Green tea is an example of a thermogenic with the potential to produce mild but clinically insignificant undesirable stimulatory effects. The use of the aforementioned thermogenic agents in combination with other extracts such as those derived from Salacia reticulata, Sesamum indicum, Lagerstroemia speciosa, Cissus quadrangularis, and Moringa olifera, as well as the use of the carotenoids as lutein and fucoxanthin, and flavonoids as naringin and hesperidin can further facilitate energy metabolism and weight management as well as sports performance without adverse side effects. © 2016 The Authors Phytotherapy Research published by John Wiley & Sons Ltd. PMID:26856274

  12. Natural fatty acid synthase inhibitors as potent therapeutic agents for cancers: A review.

    Science.gov (United States)

    Zhang, Jia-Sui; Lei, Jie-Ping; Wei, Guo-Qing; Chen, Hui; Ma, Chao-Ying; Jiang, He-Zhong

    2016-09-01

    Context Fatty acid synthase (FAS) is the only mammalian enzyme to catalyse the synthesis of fatty acid. The expression level of FAS is related to cancer progression, aggressiveness and metastasis. In recent years, research on natural FAS inhibitors with significant bioactivities and low side effects has increasingly become a new trend. Herein, we present recent research progress on natural fatty acid synthase inhibitors as potent therapeutic agents. Objective This paper is a mini overview of the typical natural FAS inhibitors and their possible mechanism of action in the past 10 years (2004-2014). Method The information was collected and compiled through major databases including Web of Science, PubMed, and CNKI. Results Many natural products induce cancer cells apoptosis by inhibiting FAS expression, with fewer side effects than synthetic inhibitors. Conclusion Natural FAS inhibitors are widely distributed in plants (especially in herbs and foods). Some natural products (mainly phenolics) possessing potent biological activities and stable structures are available as lead compounds to synthesise promising FAS inhibitors.

  13. NATURAL ANTIBIOFOULING AGENTS AS NEW CONTROL METHOD FOR PHOTOTROPHIC BIOFILMS DWELLING ON MONUMENTAL STONE SURFACES

    Directory of Open Access Journals (Sweden)

    Oana-Adriana CUZMAN

    2011-03-01

    Full Text Available Five natural antibiofoulants with terrestrial (capsaicine - CS, cinnamaldehyde - CI and marine origin (zosteric acid - ZA, poly-alkylpyridinium salts - pAPS and Ceramium botryocarpum extract - CBE have been selected and tested against phototrophic biofilm formation on the stone surfaces for their inhibitory properties. The antibiofouling agents (ABAs were incorporated into two commercial silicone based coatings (Silres BS OH 100 - S and Silres BS 290 - W. In this work, phototrophic growth was evaluated by epifluorescence microscopy and semi-quantitative image analysis. The results showed an inhibitory efficiency for almost all tested ABAs. However, this efficiency has been found for short time or when the incorporating agent were incompletely cured. Among the ABAs tested, the poly-alkylpyridinium salts and cinnamaldehyde incorporated into Silres BS 290 showed the best inhibitory efficiency.

  14. Natural Phenolic Compounds as Therapeutic and Preventive Agents for Cerebral Amyloidosis.

    Science.gov (United States)

    Yamada, Masahito; Ono, Kenjiro; Hamaguchi, Tsuyoshi; Noguchi-Shinohara, Moeko

    2015-01-01

    Epidemiological studies have suggested that diets rich in phenolic compounds may have preventive effects on the development of dementia or Alzheimer's disease (AD). We investigated the effects of natural phenolic compounds, such as myricetin (Myr), rosmarinic acid (RA), ferulic acid (FA), curcumin (Cur) and nordihydroguaiaretic acid (NDGA) on the aggregation of amyloid β-protein (Aβ), using in vitro and in vivo models of cerebral Aβ amyloidosis. The in vitro studies revealed that these phenolic compounds efficiently inhibit oligomerization as well as fibril formation of Aβ through differential binding, whilst reducing Aβ oligomer-induced synaptic and neuronal toxicity. Furthermore, a transgenic mouse model fed orally with such phenolic compounds showed significant reduction of soluble Aβ oligomers as well as of insoluble Aβ deposition in the brain. These data, together with an updated review of the literature, indicate that natural phenolic compounds have anti-amyloidogenic effects on Aβ in addition to well-known anti-oxidative and anti-inflammatory effects, hence suggesting their potential as therapeutic and/or preventive agents for cerebral Aβ amyloidosis, including AD and cerebral amyloid angiopathy (CAA). Well-designed clinical trials or preventive interventions with natural phenolic compounds are necessary to establish their efficacy as disease-modifying agents.

  15. Phylogenetic Analysis of Entomoparasitic Nematodes, Potential Control Agents of Flea Populations in Natural Foci of Plague

    Science.gov (United States)

    Koshel, E. I.; Aleshin, V. V.; Eroshenko, G. A.; Kutyrev, V. V.

    2014-01-01

    Entomoparasitic nematodes are natural control agents for many insect pests, including fleas that transmit Yersinia pestis, a causative agent of plague, in the natural foci of this extremely dangerous zoonosis. We examined the flea samples from the Volga-Ural natural focus of plague for their infestation with nematodes. Among the six flea species feeding on different rodent hosts (Citellus pygmaeus, Microtus socialis, and Allactaga major), the rate of infestation varied from 0 to 21%. The propagation rate of parasitic nematodes in the haemocoel of infected fleas was very high; in some cases, we observed up to 1,000 juveniles per flea specimen. Our study of morphology, life cycle, and rDNA sequences of these parasites revealed that they belong to three distinct species differing in the host specificity. On SSU and LSU rRNA phylogenies, these species representing three genera (Rubzovinema, Psyllotylenchus, and Spilotylenchus), constitute a monophyletic group close to Allantonema and Parasitylenchus, the type genera of the families Allantonematidae and Parasitylenchidae (Nematoda: Tylenchida). We discuss the SSU-ITS1-5.8S-LSU rDNA phylogeny of the Tylenchida with a special emphasis on the suborder Hexatylina. PMID:24804197

  16. Study on novel eco-friendly anti-creasing agents for natural silk fabric

    Institute of Scientific and Technical Information of China (English)

    Xiao Shan Liu; Tie Ling Xing; Dong Mei Xu; Guo Qiang Chen

    2012-01-01

    Three hover eco-friendly an-creasing agents nave been designed and synthesized.The natural silk fabrics treated with them exhibit higher wrinkle recovery degree,strength retention rate and whiteness than those finished with 1,2,3,4-butane tetracarboxylic acid (BTCA).The washing durability of the fabrics treated with the synthesized compounds and BTCA is similar.The chlorine atom,the carboxyl and the s-triazine ring in the synthesized.structures and the surface roughness of the silk fabric are all contributive to the improvement of the crease resistance of silk.

  17. Assay development for the discovery of semaphorin 3B inducing agents from natural product sources.

    Science.gov (United States)

    Yong, Yeonjoong; Pan, Li; Ren, Yulin; Fatima, Nighat; Ahmed, Safia; Chang, Leng Chee; Zhang, Xiaoli; Kinghorn, A Douglas; Swanson, Steven M; Carcache de Blanco, Esperanza J

    2014-10-01

    Semaphorins are a class of membrane-bound and secreted proteins. They have been found to regulate basic cell functions such as axonal growth cone guidance and recent studies have focused on their effect on tumor progression. Semaphorin 3B (Sema3B) particularly is a secreted protein that has been known to modulate proliferation and apoptosis, processes that are critical for tumor progression and development. In spite of its importance, there is yet no high-throughput screening assay available to detect or quantify the expression of Sema3B for natural product anticancer drug discovery purposes. Therefore, the development of a new high-throughput bioassay for the discovery of Sema3B inducing agents from natural product sources is described herein. A wide variety of pure compounds and extracts from plants and microorganisms has been found suitable for screening using this Sema3B assay to detect and quantify the effect of Sema3B inducing agents and thereby identify new selective bioactive Sema3B lead compounds for anticancer drug discovery and development. Also, this new bioassay procedure is based on a high-throughput platform using an enzyme-linked immunosorbent assay that involves the optimization of sensitivity and selectivity levels as well as accuracy, reproducibility, robustness, and cost effectiveness.

  18. Natural products for cancer-targeted therapy: citrus flavonoids as potent chemopreventive agents.

    Science.gov (United States)

    Meiyanto, Edy; Hermawan, Adam; Anindyajati

    2012-01-01

    Targeted therapy has been a very promising strategy of drug development research. Many molecular mechanims of diseases have been known to be regulated by abundance of proteins, such as receptors and hormones. Chemoprevention for treatment and prevention of diseases are continuously developed. Pre-clinical and clinical studies in chemoprevention field yielded many valuable data in preventing the onset of disease and suppressing the progress of their growth, making chemoprevention a challenging and a very rational strategy in future researches. Natural products being rich of flavonoids are those fruits belong to the genus citrus. Ethanolic extract of Citrus reticulata and Citrus aurantiifolia peels showed anticarcinogenic, antiproliferative, co-chemotherapeutic and estrogenic effects. Several examples of citrus flavonoids that are potential as chemotherapeutic agents are tangeretin, nobiletin, hesperetin, hesperidin, naringenin, and naringin. Those flavonoids have been shown to possess inhibition activity on certain cancer cells' growth through various mechanisms. Moreover, citrus flavonoids also perform promising effect in combination with several chemotherapeutic agents against the growth of cancer cells. Some mechanisms involved in those activities are through cell cycle modulation, antiangiogenic effect, and apoptosis induction. Previous studies showed that tangeretin suppressed the growth of T47D breast cancer cells by inhibiting ERK phosphorylation. While in combination with tamoxifen, doxorubicin, and 5-FU, respectively, it was proven to be synergist on several cancer cells. Hesperidin and naringenin increased cytotoxicitity of doxorubicin on MCF-7 cells and HeLa cells. Besides, citrus flavonoids also performed estrogenic effect in vivo. One example is hesperidin having the ability to decrease the concentration of serum and hepatic lipid and reduce osteoporosis of ovariectomized rats. Those studies showed the great potential of citrus fruits as natural product

  19. Antitumoral, antioxidant, and antimelanogenesis potencies of Hawthorn, a potential natural agent in the treatment of melanoma.

    Science.gov (United States)

    Mustapha, Nadia; Mokdad-Bzéouich, Imèn; Maatouk, Mouna; Ghedira, Kamel; Hennebelle, Thierry; Chekir-Ghedira, Leila

    2016-06-01

    The lack of an efficient agent that does not have the disadvantage of low activity (kojic acid), high cytotoxicity, and mutagenicity (hydroquinone), poor skin penetration (arbutin), or low stability in formulation (glabridin) led us to continue our research on new antipigmentation/skin-lightening agents. Therefore, research of natural products that can modulate the metabolism of pigmentation is of great interest. Otherwise, malignant melanoma is one of the most aggressive forms of skin cancer, with high metastatic potential, and currently, there is no effective chemotherapy against invasive melanoma. Therefore, it is necessary to develop new drugs with potent activity and weak side effects against melanoma. The in-vitro anticancer effect of hawthorn was analyzed against B16F10 melanoma cells using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The effect of isolated compounds from hawthorn on melanogenesis in B16F10 melanoma cells was investigated by measuring the amounts of melanin and tyrosinase spectrophotometrically at 475 nm. Balb/c mice models inoculated with B16F10 mouse tumor cells were used to evaluate the in-vivo antitumoral potential of hawthorn by assessing its effect on the growth of transplanted tumors. The antioxidant potential of tested samples was evaluated in B16F10 and primary human keratinocyte cells using a cellular antioxidant activity assay. Hawthorn tested samples inhibited effectively the growth of melanoma cells in vitro. Furthermore, it appears that tested samples from hawthorn reduced melanogenesis by inhibiting the tyrosinase activity of B16F10 cells in a dose-dependent manner. In-vivo studies showed that hawthorn total oligomer flavonoids extract treatment at a dose of 150 mg/kg body weight for 21 days in implanted tumor mice resulted in significant inhibition of the tumor growth volume and weight. In addition, tested samples showed significant cellular antioxidant capacity against the reactive oxygen species

  20. NATURAL ANTIMICROBIAL AGENT USE IN THE PRESERVATION OF FRUITS AND VEGETABLES

    Directory of Open Access Journals (Sweden)

    Elvia Nereyda Rodríguez Sauceda

    2011-01-01

    Full Text Available Today has been a need to find alternatives of conservation, because it has been associated with consumption of poison chemical preservatives. The demand for minimally processed fresh products is increasing, and interest in natural antimicrobial agents (derived from plants, so now looking for the combination of two or more factors that interact additively or synergistically controlling population microbial, allowing it to fresh produce similar products with less additives, it should be noted that the rate of microbial spoilage depends not only on microorganisms but also the chemical combination of product and type of initial microbial load. That is why the main aim of food processing is to provide comfort to humans through a safe, nutritionally adequate and meet the expectations of taste, aroma and appearance, so the use of natural food additives involves the isolation, purification, stabilization and incorporation of these compounds to food antimicrobial purposes, without adversely affecting the sensory characteristics. In general, every time we discover more plants or parts thereof which contain natural antimicrobials, such as including phenolic compounds from bark, stems, leaves, flowers, organic acids present in fruits and phytoalexins produced in plants, so as will not only safer, but better food quality and type of antimicrobials that are regarded as potentially safer sources.

  1. Single Agent Polysaccharopeptide Delays Metastases and Improves Survival in Naturally Occurring Hemangiosarcoma

    Directory of Open Access Journals (Sweden)

    Dorothy Cimino Brown

    2012-01-01

    Full Text Available The 2008 World Health Organization World Cancer Report describes global cancer incidence soaring with many patients living in countries that lack resources for cancer control. Alternative treatment strategies that can reduce the global disease burden at manageable costs must be developed. Polysaccharopeptide (PSP is the bioactive agent from the mushroom Coriolus versicolor. Studies indicate PSP has in vitro antitumor activities and inhibits the growth of induced tumors in animal models. Clear evidence of clinically relevant benefits of PSP in cancer patients, however, is lacking. The investment of resources required to complete large-scale, randomized controlled trials of PSP in cancer patients is more easily justified if antitumor and survival benefits are documented in a complex animal model of a naturally occurring cancer that parallels human disease. Because of its high metastatic rate and vascular origin, canine hemangiosarcoma is used for investigations in antimetastatic and antiangiogenic therapies. In this double-blind randomized multidose pilot study, high-dose PSP significantly delayed the progression of metastases and afforded the longest survival times reported in canine hemangiosarcoma. These data suggest that, for those cancer patients for whom advanced treatments are not accessible, PSP as a single agent might offer significant improvements in morbidity and mortality.

  2. Natural Detoxification Capacity to Inactivate Nerve Agents Sarin and VX in the Rat Blood

    Directory of Open Access Journals (Sweden)

    Jiří Bajgal

    2016-03-01

    Full Text Available Background: The method of continual determination of the rat blood cholinesterase activity was developed to study the changes of the blood cholinesterases following different intervetions. Aims: The aim of this study is registration of cholinesterase activity in the rat blood and its changes to demonstrate detoxification capacity of rats to inactivate sarin or VX in vivo. Methods: The groups of female rats were premedicated (ketamine and xylazine and cannulated to a. femoralis. Continual blood sampling (0.02 ml/min and monitoring of the circulating blood cholinesterase activity were performed. Normal activity was monitored 1–2 min and then the nerve agent was administered i.m. (2× LD50. Using different time intervals of the leg compression and relaxation following the agent injection, cholinesterase activity was monitored and according to the inhibition obtained, detoxification capacity was assessed. Results: Administration of sarin to the leg, then 1 and 5 min compression and 20 min later relaxation showed that further inhibition in the blood was not observed. On the other hand, VX was able to inhibit blood cholinesterases after this intervention. Conclusions: The results demonstrated that sarin can be naturally detoxified on the contrary to VX. Described method can be used as model for other studies dealing with changes of cholinesterases in the blood following different factors.

  3. HIV Latency-Reversing Agents Have Diverse Effects on Natural Killer Cell Function

    Science.gov (United States)

    Garrido, Carolina; Spivak, Adam M.; Soriano-Sarabia, Natalia; Checkley, Mary Ann; Barker, Edward; Karn, Jonathan; Planelles, Vicente; Margolis, David M.

    2016-01-01

    In an effort to clear persistent HIV infection and achieve a durable therapy-free remission of HIV disease, extensive pre-clinical studies and early pilot clinical trials are underway to develop and test agents that can reverse latent HIV infection and present viral antigen to the immune system for clearance. It is, therefore, critical to understand the impact of latency-reversing agents (LRAs) on the function of immune effectors needed to clear infected cells. We assessed the impact of LRAs on the function of natural killer (NK) cells, the main effector cells of the innate immune system. We studied the effects of three histone deacetylase inhibitors [SAHA or vorinostat (VOR), romidepsin, and panobinostat (PNB)] and two protein kinase C agonists [prostratin (PROST) and ingenol] on the antiviral activity, cytotoxicity, cytokine secretion, phenotype, and viability of primary NK cells. We found that ex vivo exposure to VOR had minimal impact on all parameters assessed, while PNB caused a decrease in NK cell viability, antiviral activity, and cytotoxicity. PROST caused non-specific NK cell activation and, interestingly, improved antiviral activity. Overall, we found that LRAs can alter the function and fate of NK cells, and these effects must be carefully considered as strategies are developed to clear persistent HIV infection.

  4. HIV Latency Reversing Agents have diverse effects on Natural Killer Cell Function

    Directory of Open Access Journals (Sweden)

    Carolina Garrido

    2016-09-01

    Full Text Available In an effort to clear persistent HIV infection, and achieve a durable therapy-free remission of HIV disease, extensive pre-clinical studies and early pilot clinical trials are underway to develop and test agents that can reverse latent HIV infection and present viral antigen to the immune system for clearance. It is therefore critical to understand the impact of latency reversing agents (LRAs on the function of immune effectors needed to clear infected cells. We assessed the impact of LRAs on the function of natural killer (NK cells, the main effector cells of the innate immune system. We studied the effects of three histone deacetylase inhibitors (SAHA or vorinostat, romidepsin and panobinostat and two protein kinase C (PKC agonists (prostratin and ingenol on the antiviral activity, cytotoxicity, cytokine secretion, phenotype and viability of primary NK cells. We found that ex vivo exposure to vorinostat had minimal impact on all parameters assessed, while panobinostat caused a decrease in NK cell viability, antiviral activity and cytotoxicity. Prostratin caused NK cell activation and interestingly, improved antiviral activity. Overall, we found that LRAs can alter the function and fate of NK cells, and these effects must be carefully considered as strategies are developed to clear persistent HIV infection.

  5. Systematic review of natural agents for the management of oral mucositis in cancer patients

    DEFF Research Database (Denmark)

    Yarom, Noam; Ariyawardana, Anura; Hovan, Allan

    2013-01-01

    Association of Supportive Care in Cancer/International Society for Oral Oncology. The body of evidence for each intervention, in each cancer treatment setting, was assigned an evidence level. Based on the evidence level, one of the following three guideline determinations was possible: recommendation......, suggestion, and no guideline possible. RESULTS: A total of 49 papers across 15 interventions were examined. A new suggestion was developed in favor of systemic zinc supplements administered orally in the prevention of oral mucositis in oral cancer patients receiving radiation therapy or chemoradiation (Level......Abstract PURPOSE: The aim of this study was to review the available literature and define clinical practice guidelines for the use of natural agents for the prevention and treatment of oral mucositis. METHODS: A systematic review was conducted by the Mucositis Study Group of the Multinational...

  6. Natural and genetically engineered viral agents for oncolysis and gene therapy of human cancers.

    Science.gov (United States)

    Sinkovics, Joseph G; Horvath, Joseph C

    2008-12-01

    combination of naturally oncolytic viruses and wild-type viruses rendered oncolytic and harmless by genetic engineering, that will induce complete remissions of human tumors. It may be necessary to co-administer certain chemotherapeutic agents, advanced cancer vaccines, or even immune lymphocytes, and targeted therapeuticals, to ascertain, that remissions induced by the viral agents will remain complete and durable; will co-operate with anti-tumor host immune reactions, and eventually will result in cures of advanced metastatic human cancers.

  7. A Quantitative Ethnopharmacological Documentation of Natural Pharmacological Agents Used by Pediatric Patients in Mauritius

    Directory of Open Access Journals (Sweden)

    M. Fawzi Mahomoodally

    2014-01-01

    Full Text Available The pediatric population constitutes the most vulnerable patients due to a dearth of approved drugs. Consequently, there is a pressing need to probe novel natural pharmacological agents in an endeavour to develop new drugs to address pediatric illnesses. To date, no studies have explored the use of natural therapies for pediatric health care in Mauritius. Parents (n=325 from different regions of the island were interviewed. Quantitative indexes such as fidelity level (FL, informant consensus factor (FIC, and use-value (UV were calculated. Thirty-two plants were reported to be used by pediatric patients. Gastrointestinal disorders (FIC=0.97 encompassing regurgitation, infantile colic, and stomach aches were the most common ailments managed with herbs. Matricaria chamomilla used for infantile colic and its pharmacological properties has previously been documented for pediatric patients. Product from A. mellifera (UV = 0.75 was the most utilized zootherapy for managing cough. Most plants and animal products reported in this study have bioactive constituents supported by existing scientific literature but their use for the pediatric population is scant. The present ethnopharmacological study has opened new perspectives for further research into their pharmacology, which can subsequently support and facilitate timely pediatric medicinal product development.

  8. Grafted natural polymer as new drag reducing agent: An experimental approach

    Directory of Open Access Journals (Sweden)

    Abdulbari Hayder A.

    2012-01-01

    Full Text Available The present investigation introduces a new natural drag reducing agent which has the ability to improve the flow in pipelines carrying aqueous or hydrocarbon liquids in turbulent flow. Okra (Abelmoschus esculentus mucilage drag reduction performance was tested in water and hydrocarbon (gas-oil media after grafting. The drag reduction test was conducted in a buildup closed loop liquid circulation system consists of two pipes 0.0127 and 0.0381 m Inside Diameter (ID, four testing sections in each pipe (0.5 to 2.0 m, tank, pump and pressure transmitters. Reynolds number (Re, additive concentration and the transported media type (water and gas-oil, were the major drag reduction variables investigated. The experimental results show that, new additive drag reduction ability is high with maximum percentage of drag reduction (%Dr up to 60% was achieved. The experimental results showed that the drag reduction ability increased by increasing the additive concentration. The %Dr was found to increase by increasing the Re by using the water-soluble additive while it was found to decrease by increasing the Re when using the oil-soluble additive. The %Dr was higher in the 0.0381 m ID pipe. Finally, the grafted and natural mucilage showed high resistance to shear forces when circulated continuously for 200 seconds in the closed-loop system.

  9. Saffron as an antidote or a protective agent against natural or chemical toxicities.

    Science.gov (United States)

    Razavi, Bibi Marjan; Hosseinzadeh, Hossein

    2015-05-01

    Saffron (Crocus sativus) is an extensively used food additive for its color and taste. Since ancient times this plant has been introduced as a marvelous medicine throughout the world. The wide spectrum of saffron pharmacological activities is related to its major constituents including crocin, crocetin and safranal. Based on several studies, saffron and its active ingredients have been used as an antioxidant, antiinflammatory and antinociceptive, antidepressant, antitussive, anticonvulsant, memory enhancer, hypotensive and anticancer. According to the literatures, saffron has remarkable therapeutic effects. The protective effects of saffron and its main constituents in different tissues including brain, heart, liver, kidney and lung have been reported against some toxic materials either natural or chemical toxins in animal studies.In this review article, we have summarized different in vitro and animal studies in scientific databases which investigate the antidotal and protective effects of saffron and its major components against natural toxins and chemical-induced toxicities. Due to the lake of human studies, further investigations are required to ascertain the efficacy of saffron as an antidote or a protective agent in human intoxication.

  10. Natural chromenes and chromene derivatives as potential anti-trypanosomal agents.

    Science.gov (United States)

    Batista, João Marcos; Lopes, Adriana Aparecida; Ambrósio, Daniela Luz; Regasini, Luis Octávio; Kato, Massuo Jorge; Bolzani, Vanderlan da Silva; Cicarelli, Regina Maria Barretto; Furlan, Maysa

    2008-03-01

    The aim of the study was to investigate the anti-trypanocidal activities of natural chromene and chromene derivatives. Five chromenes were isolated from Piper gaudichaudianum and P. aduncum, and a further seven derivatives were prepared using standard reduction, methylation and acetylation procedures. These compounds were assayed in vitro against epimastigote forms of Trypanosoma cruzi, the causative agent of Chagas disease. The results showed that the most of the compounds, especially those possessing electron-donating groups as substituents on the aromatic ring, showed potent trypanocidal activity. The most active compound, [(2S)-methyl-2-methyl-8-(3''-methylbut-2''-enyl)-2-(4'-methylpent-3'-enyl)-2H-chromene-6-carboxylate], was almost four times more potent than benznidazole (the positive control) and showed an IC50 of 2.82 microM. The results reveal that chromenes exhibit significant anti-trypanocidal activities and indicate that this class of natural product should be considered further in the development of new and more potent drugs for use in the treatment of Chagas disease.

  11. A quantitative ethnopharmacological documentation of natural pharmacological agents used by pediatric patients in Mauritius.

    Science.gov (United States)

    Mahomoodally, M Fawzi; Sreekeesoon, D Priyamka

    2014-01-01

    The pediatric population constitutes the most vulnerable patients due to a dearth of approved drugs. Consequently, there is a pressing need to probe novel natural pharmacological agents in an endeavour to develop new drugs to address pediatric illnesses. To date, no studies have explored the use of natural therapies for pediatric health care in Mauritius. Parents (n = 325) from different regions of the island were interviewed. Quantitative indexes such as fidelity level (FL), informant consensus factor (F IC), and use-value (UV) were calculated. Thirty-two plants were reported to be used by pediatric patients. Gastrointestinal disorders (F IC = 0.97) encompassing regurgitation, infantile colic, and stomach aches were the most common ailments managed with herbs. Matricaria chamomilla used for infantile colic and its pharmacological properties has previously been documented for pediatric patients. Product from A. mellifera (UV = 0.75) was the most utilized zootherapy for managing cough. Most plants and animal products reported in this study have bioactive constituents supported by existing scientific literature but their use for the pediatric population is scant. The present ethnopharmacological study has opened new perspectives for further research into their pharmacology, which can subsequently support and facilitate timely pediatric medicinal product development.

  12. Recent advances in pharmacologic study of natural anticancer agents in China

    Directory of Open Access Journals (Sweden)

    Bin Xu

    1991-01-01

    Full Text Available In this paper a number of anticancer agents of natural origin will be presented. Hydroxycamtothecin (HCPT was found to produce a strong inhibitory action on a variety of animal tumors. It is also effective for treatment of patients with gastric carcinoma, liver carcinoma, tumor of head and neck or leukemia. Pharmacologic studies showed that it could depress S phase of tumor cells significantly and cause formation of cellular chromatid breaks. By means of alkaline elution and nick translation methods it has been proved that HCPT induced DNA singlo strand breaks remarkably. Homoharringyonine (hhrt was shown to be effective against acute leukemia. Recent experiments in tumor-bearing mice inidcated that (HHRT could diminish tumor metastasis. Using molecular hybridization technique it was demonstrated that (HHRT decreased the content of c-myc RNA in the cytoplasm but not in the nuclei. Lycobetaine (LBT poddrddrf dytnh inhibitory effects on a number of ascites tumors. In clinical trials it was against ovarian and gastric carcinomas. It is able to intercalate into DNA. Oxalysine (OXL is a new antibiotic and shown to be effective against tumor metastatis. When used in combination with 5-FU, its anticancer action could be enhanced. Other natural compounds such as indirubin, ß-elemene, irisquinone, oridonine, norcantharidin and PSP have been also found to possess antitumor action.

  13. Discovery and Development of Natural Product-derived Chemotherapeutic Agents Based on a Medicinal Chemistry Approach⊥†

    OpenAIRE

    Lee, Kuo-Hsiung

    2010-01-01

    Medicinal plants have long been an excellent source of pharmaceutical agents. Accordingly, the long term objectives of the author's research program are to discover and design new chemotherapeutic agents based on plant-derived compound leads by using a medicinal chemistry approach, which is a combination of chemistry and biology. Different examples of promising bioactive natural products and their synthetic analogs, including sesquiterpene lactones, quassinoids, naphthoquinones, phenylquinolo...

  14. Discovery and Development of Natural Product-derived Chemotherapeutic Agents Based on a Medicinal Chemistry Approach⊥†

    OpenAIRE

    Lee, Kuo-Hsiung

    2010-01-01

    Medicinal plants have long been an excellent source of pharmaceutical agents. Accordingly, the long term objectives of the author's research program are to discover and design new chemotherapeutic agents based on plant-derived compound leads by using a medicinal chemistry approach, which is a combination of chemistry and biology. Different examples of promising bioactive natural products and their synthetic analogs, including sesquiterpene lactones, quassinoids, naphthoquinones, phenylquinolo...

  15. Natural potential therapeutic agents of neurodegenerative diseases from the traditional herbal medicine Chinese dragon's blood.

    Science.gov (United States)

    Li, Ning; Ma, Zhongjun; Li, Mujie; Xing, Yachao; Hou, Yue

    2014-03-28

    Dragon's blood has been used as a famous traditional medicine since ancient times by many cultures. It is a deep red resin, obtained from more than 20 different species of four distinct genera. Red resin of Dracaena cochinchinensis S.C. Chen, known as Chinese dragon's blood or Yunnan dragon's blood, has been shown to promote blood circulation, alleviate inflammation, and to treat stomach ulcers, diarrhea, diabetes, and bleeding. This study investigated an effective approach to identify natural therapeutic agents for neurodegeneration from herbal medicine. The dichloride extract and isolated effective constituents of Chinese dragon's blood showed quinone oxidoreductase 1 (NQO1) inducing activity and anti-inflammatory effect significantly, which are therapy targets of various neurodegenerative diseases. Multiple chromatography and spectra analysis were utilized to afford effective constituents. Then Hepa 1c1c7 and BV-2 cells were employed to assay their NQO1 inducing and anti-inflammatory activities, respectively. Bioactivities guided isolation afforded 21 effective constituents, including two new polymers cochinchinenene E (1), cochinchinenene F (2) and a new steroid dracaenol C (16). The main constituent 3 (weight percent 0.2%), 5 (weight percent 0.017%), 4 (weight percent 0.009%), 9 (weight percent 0.094%), 10 (weight percent 0.017%) and 8 (weight percent 0.006%) are responsible for the anti-inflammatory activities of Chinese dragon's blood. While, new compounds 1, 2 and known compounds 5, 11 showed good NQO1 inducing activities. The brief feature of the activities and structures was discussed accordingly. Overviewing the bioactivities and phytochemical study result, 4'-hydroxy-2,4-dimethoxydihydrochalcone (3) and pterostilbene (5) as effective constituents of Chinese dragon's blood, were found to be potential candidate therapeutic agents for neurodegenerative diseases. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  16. Ginkgo biloba: a natural reducing agent for the synthesis of cytocompatible graphene

    Science.gov (United States)

    Gurunathan, Sangiliyandi; Han, Jae Woong; Park, Jung Hyun; Eppakayala, Vasuki; Kim, Jin-Hoi

    2014-01-01

    Background Graphene is a novel two-dimensional planar nanocomposite material consisting of rings of carbon atoms with a hexagonal lattice structure. Graphene exhibits unique physical, chemical, mechanical, electrical, elasticity, and cytocompatible properties that lead to many potential biomedical applications. Nevertheless, the water-insoluble property of graphene restricts its application in various aspects of biomedical fields. Therefore, the objective of this work was to find a novel biological approach for an efficient method to synthesize water-soluble and cytocompatible graphene using Ginkgo biloba extract (GbE) as a reducing and stabilizing agent. In addition, we investigated the biocompatibility effects of graphene in MDA-MB-231 human breast cancer cells. Materials and methods Synthesized graphene oxide (GO) and GbE-reduced GO (Gb-rGO) were characterized using various sequences of techniques: ultraviolet-visible (UV-vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy. Biocompatibility of GO and Gb-rGO was assessed in human breast cancer cells using a series of assays, including cell viability, apoptosis, and alkaline phosphatase (ALP) activity. Results The successful synthesis of graphene was confirmed by UV-vis spectroscopy and FTIR. DLS analysis was performed to determine the average size of GO and Gb-rGO. X-ray diffraction studies confirmed the crystalline nature of graphene. SEM was used to investigate the surface morphologies of GO and Gb-rGO. AFM was employed to investigate the morphologies of prepared graphene and the height profile of GO and Gb-rGO. The formation of defects in Gb-rGO was confirmed by Raman spectroscopy. The biocompatibility of the prepared GO and Gb-rGO was investigated using a water-soluble tetrazolium 8 assay on human breast cancer cells. GO exhibited a dose-dependent toxicity, whereas Gb

  17. Ginkgo biloba: a natural reducing agent for the synthesis of cytocompatible graphene.

    Science.gov (United States)

    Gurunathan, Sangiliyandi; Han, Jae Woong; Park, Jung Hyun; Eppakayala, Vasuki; Kim, Jin-Hoi

    2014-01-01

    Graphene is a novel two-dimensional planar nanocomposite material consisting of rings of carbon atoms with a hexagonal lattice structure. Graphene exhibits unique physical, chemical, mechanical, electrical, elasticity, and cytocompatible properties that lead to many potential biomedical applications. Nevertheless, the water-insoluble property of graphene restricts its application in various aspects of biomedical fields. Therefore, the objective of this work was to find a novel biological approach for an efficient method to synthesize water-soluble and cytocompatible graphene using Ginkgo biloba extract (GbE) as a reducing and stabilizing agent. In addition, we investigated the biocompatibility effects of graphene in MDA-MB-231 human breast cancer cells. Synthesized graphene oxide (GO) and GbE-reduced GO (Gb-rGO) were characterized using various sequences of techniques: ultraviolet-visible (UV-vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy. Biocompatibility of GO and Gb-rGO was assessed in human breast cancer cells using a series of assays, including cell viability, apoptosis, and alkaline phosphatase (ALP) activity. The successful synthesis of graphene was confirmed by UV-vis spectroscopy and FTIR. DLS analysis was performed to determine the average size of GO and Gb-rGO. X-ray diffraction studies confirmed the crystalline nature of graphene. SEM was used to investigate the surface morphologies of GO and Gb-rGO. AFM was employed to investigate the morphologies of prepared graphene and the height profile of GO and Gb-rGO. The formation of defects in Gb-rGO was confirmed by Raman spectroscopy. The biocompatibility of the prepared GO and Gb-rGO was investigated using a water-soluble tetrazolium 8 assay on human breast cancer cells. GO exhibited a dose-dependent toxicity, whereas Gb-rGO-treated cells showed significant

  18. An evaluation of pretreatment agents for the stimulation of secondary biogenic coalbed natural gas

    Science.gov (United States)

    Huang, Zaixing

    Coalbed methane is considered to be an underexploited source of clean energy and, with the realization of its biogenic nature, it has attracted increasing interest in recent decades. Most of the published studies on biogenic coal bed natural gas (CBNG) have focused either on biostimulation (the addition of nutrients to stimulate the native microbial populations) or bioaugmentation (the addition of both nutrients and non-native microbial consortia of microorganisms). Although these approaches have shown promise, they are predicated on the assumption that the coal seam is nutrient-limited or that the existing microbial communities are not optimized to convert coal to natural gas. The premise of this research is that the organic matter present within the coal matrix is, for the most part, environmentally inert and not readily available to the microorganisms living within the coal seam. The goal of this research has been to focus on treatments that will increase the solubility, and hence the bioavailability, of coal to the indigenous microbial community. Initially, treatment agents representing acids, bases and oxidants were selected to evaluate the potential for the in situ solubilization and depolymerization of subbituminous coal. The bioavailability of the coal-derived constituents was then evaluated aerobically using biometer assays and anaerobic bioassays. The experiments have shown that the acid (nitric acid) and base (sodium hydroxide) treatments are more efficient than the oxidants (potassium permanganate and catalyzed hydrogen peroxide) with respect to total organic carbon (TOC). The carbon contained in the solubilized/depolymerized product of nitric acid treatments accounted for approximately 14% of the carbon from the Powder River Basin (PRB) coal evaluated in the study; however, the biometer assays revealed that the bioavailability of the solubilized/depolymerized products was not directly correlated to the amount of dissolved organic carbon (TOC). The

  19. Human-agent service matching using natural language queries: system test and training

    NARCIS (Netherlands)

    Pasman, W.; Lindenberg, J.

    2006-01-01

    Smart environments, ambient intelligence and intelligent agents leave the user lost between large amounts of services. Ad-hoc networks, mobile agents and mobile devices make the set of available services dynamic over time and space, increasing the user’s problems to find the service he needs. Earlie

  20. [Comparison of the thermostability of natural (sulfoprolamine and sodium usnate) and synthetic (climbazole and piroctone olamine) antidandruff agents].

    Science.gov (United States)

    Coiffard, C; Coiffard, L; de Roeck-Holtzhauer, Y

    1999-09-01

    We compared thermostability of various natural (sulfoprolamine and sodium usnate) or synthetic (climbazol and piroctone olamine) antidandruff agents in aqueous diluted solution at pH around 7. Thermodegradation of these solutions was studied by an isothermal method in thermostatically controlled ovens, at three temperatures (50, 70 and 90 degrees C). For each molecule, we determined at 20 degrees C t90% (time necessary to obtain a decrease of 10% of the initial concentration, value which shows the stability of the product). The present study shows that piroctone olamine is the most stable antidandruff agent among those studied.

  1. 鱼藤素可影响斑马鱼胚胎Wnt信号通路相关基因的表达*★%Deguelin regulates the expression of Wnt signaling pathway related genes in Zebrafish embryo

    Institute of Scientific and Technical Information of China (English)

    刘瑞瑾; 吴新荣

    2013-01-01

    BACKGROUND:Previous studies found that in different periods of early development of zebrafish, embryos treated with certain concentration of deguelin show varying degrees of developmental delay and abnormal phenotype. OBJECTIVE:To observe the effect of deguelin on expression of Wnt signaling pathway related genes in Zebrafish embryo during early embryo development. METHODS:Zebrafish embryos that incubated to the shield period were col ected and put into the 6-wel plate, 0.6μmol/L deguelin solution were added and treated in dark, and then cultured in the incubator under 28℃.Zebrafish em bryos treated with 0.1%dimethylsulfoxide solution were as control group, and cultured in the same conditions. At 6, 8, 10, 12, 14 and 24 hours after fertilization, phenotype of Zebrafish embryos was observed with upright fluorescence microscope. The expression levels of target genes before and after treatment were tested by quantitative real time PCR. RESULTS AND CONCLUSION:The embryos treated by deguelin on shield stage stop growing and stay at bud stage;the expressions of wnt9a, wnt10b, axin2 as wel as snail1b and Jnk2 related with Wnt signal were changed significantly, among them, the expression of wnt9a, wnt10b, axin2 and snail 1b were decreased, while the expression of Jnk2 was increased. Deguelin has a negative effect on Zebrafish in vivo Wnt signal.%  背景:前期研究发现,在斑马鱼早期发育的不同时期,经过一定浓度鱼藤素处理的胚胎表现出不同程度的发育延缓和表型异常。  目的:观察斑马鱼早期胚胎发育过程中鱼藤素对wnt信号通路相关基因表达的影响。  方法:收集孵育至shield期的斑马鱼胚胎于6孔板中,加入0.6μmol/L浓度的鱼藤素溶液,避光处理,28℃培养箱中孵养。用0.1%二甲基亚砜溶液作为对照组,相同条件培养。在受精后6,8,10,12,14,24 h时用正置荧光显微镜拍照观察鱼藤素处理后斑马鱼胚胎发育表

  2. Brownian agents and active particles collective dynamics in the natural and social sciences

    CERN Document Server

    Schweitzer, Frank

    2007-01-01

    ""This book lays out a vision for a coherent framework for understanding complex systems"" (from the foreword by J. Doyne Farmer). By developing the genuine idea of Brownian agents, the author combines concepts from informatics, such as multiagent systems, with approaches of statistical many-particle physics. This way, an efficient method for computer simulations of complex systems is developed which is also accessible to analytical investigations and quantitative predictions. The book demonstrates that Brownian agent models can be successfully applied in many different contexts, ranging from

  3. Natural Ferrihydrite as an Agent for Reducing Turbidity Caused by Suspended Clays

    Science.gov (United States)

    The turbidity of water can be reduced by the addition of positively charged compounds which coagulate negatively charged clay particles in suspension causing them to flocculate. This research was conducted to determine the effectiveness of the Fe oxide mineral ferrihydrite as a flocculating agent fo...

  4. Functional and structural microbial diversity in organic and conventional viticulture: organic farming benefits natural biocontrol agents.

    Science.gov (United States)

    Schmid, Florian; Moser, Gerit; Müller, Henry; Berg, Gabriele

    2011-03-01

    Statistically significant differences in the structure and function of above-ground grapevine-associated microorganisms from organically and conventionally managed vineyards were found. Aureobasidium pullulans, a copper-detoxifying fungus and biocontrol agent, plays a key role in explaining these differences. The black fungus was strongly enriched in the communities of organically managed plants and yielded a higher indigenous antiphytopathogenic potential.

  5. Acquired natural enemies of the weed biological control agent Oxyops vitiosa (Coleoptera: Curculionidae)

    Science.gov (United States)

    The Australian curculionid Oxyops vitiosa Pascoe was introduced into Florida during 1997 as a biological control agent of the invasive tree Melaleuca quinquenervia (Cav.) S.T. Blake. Populations of the weevil increased rapidly and became widely distributed throughout much of the invasive tree’s adve...

  6. Mycalamides, pederin and psymberin as natural carbohydrates and potential antitumor agents: past and future perspectives.

    Science.gov (United States)

    Witczak, Zbigniew J; Rampulla, Ricky M; Bommareddy, Ajay

    2012-12-01

    The mycalamide class of potent antiviral and antitumor natural compounds originally isolated from marine sponges in 1988 is a new interdisciplinary approach to molecular recognition. We review new synthetic approaches to this new family of natural products with remarkable biological activity. Some biological evaluation data are compiled and compared to other structurally similar molecular targets.

  7. Computed Tomography Imaging of Solid Tumors Using a Liposomal-Iodine Contrast Agent in Companion Dogs with Naturally Occurring Cancer.

    Directory of Open Access Journals (Sweden)

    Ketan B Ghaghada

    Full Text Available Companion dogs with naturally occurring cancer serve as an important large animal model in translational research because they share strong similarities with human cancers. In this study, we investigated a long circulating liposomal-iodine contrast agent (Liposomal-I for computed tomography (CT imaging of solid tumors in companion dogs with naturally occurring cancer.The institutional animal ethics committees approved the study and written informed consent was obtained from all owners. Thirteen dogs (mean age 10.1 years with a variety of masses including primary and metastatic liver tumors, sarcomas, mammary carcinoma and lung tumors, were enrolled in the study. CT imaging was performed pre-contrast and at 15 minutes and 24 hours after intravenous administration of Liposomal-I (275 mg/kg iodine dose. Conventional contrast-enhanced CT imaging was performed in a subset of dogs, 90 minutes prior to administration of Liposomal-I. Histologic or cytologic diagnosis was obtained for each dog prior to admission into the study.Liposomal-I resulted in significant (p 1 cm demonstrated a heterogeneous pattern of intra-tumoral signal with visibly higher signal enhancement at the post-24 hour time point. Extra-hepatic, extra-splenic tumors, including histiocytic sarcoma, anaplastic sarcoma, mammary carcinoma and lung tumors, were visualized with a heterogeneous enhancement pattern in the post-24 hour scan.The long circulating liposomal-iodine contrast agent enabled prolonged visualization of small and large tumors in companion dogs with naturally occurring cancer. The study warrants future work to assess the sensitivity and specificity of the Liposomal-I agent in various types of naturally occurring canine tumors.

  8. Discovery and Development of Natural Product-derived Chemotherapeutic Agents Based on a Medicinal Chemistry Approach⊥†

    Science.gov (United States)

    Lee, Kuo-Hsiung

    2010-01-01

    Medicinal plants have long been an excellent source of pharmaceutical agents. Accordingly, the long term objectives of the author's research program are to discover and design new chemotherapeutic agents based on plant-derived compound leads by using a medicinal chemistry approach, which is a combination of chemistry and biology. Different examples of promising bioactive natural products and their synthetic analogs, including sesquiterpene lactones, quassinoids, naphthoquinones, phenylquinolones, dithiophenediones, neo-tanshinlactone, tylophorine, suksdorfin, DCK, and DCP, will be presented with respect to their discovery and preclinical development as potential clinical trial candidates. Research approaches include bioactivity- or mechanism of action-directed isolation and characterization of active compounds, rational drug design-based modification and analog synthesis, as well as structure-activity relationship and mechanism of action studies. Current clinical trials agents discovered by the Natural Products Research Laboratories, University of North Carolina, include bevirimat (dimethyl succinyl betulinic acid), which is now in Phase IIb trials for treating AIDS. Bevirimat is also the first in a new class of HIV drug candidates called “maturation inhibitors”. In addition, an etoposide analog, GL-331, progressed to anticancer Phase II clinical trials, and the curcumin analog JC-9 is in Phase II clinical trials for treating acne and in development for trials against prostate cancer. The discovery and development of these clinical trials candidates will also be discussed. PMID:20187635

  9. Determination of the infectious nature of the agent of acute hepatopancreatic necrosis syndrome affecting penaeid shrimp.

    Science.gov (United States)

    Tran, Loc; Nunan, Linda; Redman, Rita M; Mohney, Leone L; Pantoja, Carlos R; Fitzsimmons, Kevin; Lightner, Donald V

    2013-07-09

    A new emerging disease in shrimp, first reported in 2009, was initially named early mortality syndrome (EMS). In 2011, a more descriptive name for the acute phase of the disease was proposed as acute hepatopancreatic necrosis syndrome (AHPNS). Affecting both Pacific white shrimp Penaeus vannamei and black tiger shrimp P. monodon, the disease has caused significant losses in Southeast Asian shrimp farms. AHPNS was first classified as idiopathic because no specific causative agent had been identified. However, in early 2013, the Aquaculture Pathology Laboratory at the University of Arizona was able to isolate the causative agent of AHPNS in pure culture. Immersion challenge tests were employed for infectivity studies, which induced 100% mortality with typical AHPNS pathology to experimental shrimp exposed to the pathogenic agent. Subsequent histological analyses showed that AHPNS lesions were experimentally induced in the laboratory and were identical to those found in AHPNS-infected shrimp samples collected from the endemic areas. Bacterial isolation from the experimentally infected shrimp enabled recovery of the same bacterial colony type found in field samples. In 3 separate immersion tests, using the recovered isolate from the AHPNS-positive shrimp, the same AHPNS pathology was reproduced in experimental shrimp with consistent results. Hence, AHPNS has a bacterial etiology and Koch's Postulates have been satisfied in laboratory challenge studies with the isolate, which has been identified as a member of the Vibrio harveyi clade, most closely related to V. parahemolyticus.

  10. Natural antimicrobial/antioxidant agents in meat and poultry products as well as fruits and vegetables: A review.

    Science.gov (United States)

    Aziz, Marya; Karboune, Salwa

    2016-07-20

    Synthetic preservatives are widely used by the food industry to control the growth of spoilage and pathogenic microorganisms and to inhibit the process of lipid oxidation extending the shelf-life, quality and safety of food products. However, consumer's preference for natural food additives and concern regarding the safety of synthetic preservatives prompted the food industry to look for natural alternatives. Natural antimicrobials, including plant extracts and their essential oils, enzymes, peptides, bacteriocins, bacteriophages, and fermented ingredients have all been shown to have the potential for use as alternatives to chemical antimicrobials. Some spices, herbs and other plant extracts were also reported to be strong antioxidants. The antimicrobial/antioxidant activities of some plant extracts and/or their essential oils are mainly due to the presence of some major bioactive compounds, including phenolic acids, terpenes, aldehydes, and flavonoids. The proposed mechanisms of action of these natural preservatives are reported. An overview of the research done on the direct incorporation of natural preservatives agents into meat and poultry products as well as fruit and vegetables to extend their shelf-life is presented. The development of edible packaging materials containing natural preservatives is growing and their applications in selected food products are also presented in this review.

  11. Fabrication and evaluation of oral tablets using natural mucoadhesive agent from seeds of Caesalpinia pulcherrima (L. SW

    Directory of Open Access Journals (Sweden)

    Jeevanandham S

    2010-01-01

    Full Text Available Oral mucoadhesive sustained drug delivery systems of salbutamol sulfate were formulated using an isolated natural agent from the seeds of Caesalpinia pulcherrima. The isolated material was evaluated for various parameters, such as, melting point, viscosity, pH, elemental analysis, swelling index, phytochemical constituents, and solubility studies. The mucoadhesive characters of the isolated substance were identified by a comparative study with hydroxyl propyl cellulose and sodium alginate, by various in vitro methods, such as, Shear stress measurement, Wilhelmy′s method, Falling sphere method, and Detachment force measurement. Formulation and evaluation of mucoadhesive oral tablets of salbutamol sulfate (100 mg, using isolated natural materials in different proportions, and in vitro release studies, were carried out for three different formulations according to the U.S.P apparatus two (paddle method. Each 100 mg tablet was taken in 900 ml of acid buffer 1.2 and maintained at 37˚C. After two hours the filtrate was collected and replaced in buffer 7.4. In vitro releases of three different formulations for nine hours were studied, which showed the sustained action of drug release with increasing the concentration of the isolated natural mucoadhesive agent in the formulations.

  12. Lab scale testing of novel natural analog in situ stabilization agents

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, P. [Lockheed Martin Idaho Technology Co., Idaho Falls, ID (United States)

    1997-12-31

    This report summarizes the laboratory-scale test results on several novel in situ treatment and stabilization agents for buried hazardous and radioactive waste. Paraffin, hematite and phosphate materials were examined when combined with soil and other wastes representative of what might be present at buried waste DOE sites. Hematite was made from the reaction of agricultural iron and lime slurries to form gypsum and iron oxide/hydroxide. Common household paraffin was melted, both with and without a zeolitic additive, waste added and then cooled. Magnesium phosphate was made from the reaction of magnesium oxide and phosphoric acid or potassium biphosphate to form, magnesium phosphate. All were tested with soil and some with additional waste sumulants such as ash, machine oil and nitrate salts. The following laboratory-generated data indicate that all waste encapsulation materials tested are appropriate materials, for field in situ testing. Compressive strengths of treated Idaho National Engineering and Environment Laboratory (INEEL) soil and the waste encapsulation material were sufficient to prevent collapse of the void space in waste, i.e., greater than the NRC 60 psi minimum. The mineralogy and microstructure of hematite was amorphous but should progress to an interlocking crystalline solid. Phosphate was crystalline with characteristics of higher temperature ceramics. Paraffin is non crystalline but encapsulates even very fine grained INEEL soils. Each agent appears to be chemically and physically inert to possible waste materials such as, nitrates and machine cutting oil. Two of the agents hematite and phosphate react favorably with ash increasing the metals retention at higher waste loadings than Portland cement. Hematite, phosphate and zeolite decrease leaching of most hazardous metals from waste when compared to untreated waste and soil. Solution pH, time for reaction initiation, and viscosity values are conducive to jet-grouting application.

  13. A natural and readily available crowding agent: NMR studies of proteins in hen egg white.

    Science.gov (United States)

    Martorell, Gabriel; Adrover, Miquel; Kelly, Geoff; Temussi, Piero Andrea; Pastore, Annalisa

    2011-05-01

    In vitro studies of biological macromolecules are usually performed in dilute, buffered solutions containing one or just a few different biological macromolecules. Under these conditions, the interactions among molecules are diffusion limited. On the contrary, in living systems, macromolecules of a given type are surrounded by many others, at very high total concentrations. In the last few years, there has been an increasing effort to study biological macromolecules directly in natural crowded environments, as in intact bacterial cells or by mimicking natural crowding by adding proteins, polysaccharides, or even synthetic polymers. Here, we propose the use of hen egg white (HEW) as a simple natural medium, with all features of the media of crowded cells, that could be used by any researcher without difficulty and inexpensively. We present a study of the stability and dynamics behavior of model proteins in HEW, chosen as a prototypical, readily accessible natural medium that can mimic cytosol. We show that two typical globular proteins, dissolved in HEW, give NMR spectra very similar to those obtained in dilute buffers, although dynamic parameters are clearly affected by the crowded medium. The thermal stability of one of these proteins, measured in a range comprising both heat and cold denaturation, is also similar to that in buffer. Our data open new possibilities to the study of proteins in natural crowded media. Copyright © 2010 Wiley-Liss, Inc.

  14. Current Perspective in the Discovery of Anti-aging Agents from Natural Products.

    Science.gov (United States)

    Ding, Ai-Jun; Zheng, Shan-Qing; Huang, Xiao-Bing; Xing, Ti-Kun; Wu, Gui-Sheng; Sun, Hua-Ying; Qi, Shu-Hua; Luo, Huai-Rong

    2017-05-31

    Aging is a process characterized by accumulating degenerative damages, resulting in the death of an organism ultimately. The main goal of aging research is to develop therapies that delay age-related diseases in human. Since signaling pathways in aging of Caenorhabditis elegans (C. elegans), fruit flies and mice are evolutionarily conserved, compounds extending lifespan of them by intervening pathways of aging may be useful in treating age-related diseases in human. Natural products have special resource advantage and with few side effect. Recently, many compounds or extracts from natural products slowing aging and extending lifespan have been reported. Here we summarized these compounds or extracts and their mechanisms in increasing longevity of C. elegans or other species, and the prospect in developing anti-aging medicine from natural products.

  15. Morphology of Silica-Reinforced Natural Rubber: Effect of Silane Coupling Agent

    NARCIS (Netherlands)

    Sarkawi, S.S.; Dierkes, W.K.; Noordermeer, J.W.M.

    2015-01-01

    A good dispersion of silica in a rubber vulcanizate is important as it influences the filler-to-rubber interaction and consequently the final properties. This article presents an investigation into the morphology of silica-reinforced natural rubber (NR) in the presence and absence of a silane coupli

  16. Enteric-coated tablet of risedronate sodium in combination with phytic acid, a natural chelating agent, for improved oral bioavailability.

    Science.gov (United States)

    Kim, Jeong S; Jang, Sun W; Son, Miwon; Kim, Byoung M; Kang, Myung J

    2016-01-20

    The oral bioavailability (BA) of risedronate sodium (RS), an antiresorptive agent, is less than 1% due to its low membrane permeability as well as the formation of non-absorbable complexes with multivalent cations such as calcium ion (Ca(2+)) in the gastrointestinal tract. In the present study, to increase oral BA of the bisphosphonate, a novel enteric-coated tablet (ECT) dosage form of RS in combination with phytic acid (IP6), a natural chelating agent recognized as safe, was formulated. The chelating behavior of IP6 against Ca(2+), including a stability constant for complex formulation was characterized using the continuous variation method. Subsequently, in vitro dissolution profile and in vivo pharmacokinetic profile of the novel ECT were evaluated comparatively with that of the marketed product (Altevia, Sanofi, US), an ECT containing ethylenediaminetetraacetic acid (EDTA) as a chelating agent, in beagle dogs. The logarithm of stability constant for Ca(2+)-IP6 complex, an equilibrium constant approximating the strength of the interaction between two chemicals to form complex, was 19.05, which was 3.9-fold (pIP6-containing ECT were approximately 7.9- (pIP6 for an oral therapy with the bisphosphonate for improved BA. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. In Silico Molecular Docking Analysis of Natural Pyridoacridines as Anticancer Agents

    Directory of Open Access Journals (Sweden)

    Vikas Sharma

    2016-01-01

    Full Text Available Docking studies are proved to be an essential tool that facilitates the structural diversity of natural products to be harnessed in an organized manner. In this study, pyridoacridines containing natural anticancer pigments were subjected to docking studies using Glide (Schrodinger. Investigations were carried out to find out the potential molecular targets for these selected pigments. The docking was carried out on different cancer macromolecules involved in different cell cycle pathways, that is, CDK-2, CDK-6, Bcl-2, VEGFR-2, IGF-1R kinase, and G-Quadruplexes. CDK-6 was found to be the most suitable anticancer target for the pyridoacridines. In addition, effectiveness of the study was further evaluated by performing docking of known inhibitors against their respective selected macromolecules. However, the results are preliminary and experimental evaluation will be carried out in near future.

  18. Evaluation of some microbial agents, natural and chemical compounds for controlling tomato leaf miner, Tuta absoluta (Meyrick (Lepidoptera: Gelechiidae

    Directory of Open Access Journals (Sweden)

    Abd El-Ghany Nesreen M.

    2016-12-01

    Full Text Available Solanaceous plants have a great economic impact in Egypt. These groups of plants include potatoes, tomatoes and eggplants. The new invasive pest of tomatoes, Tuta absoluta (Meyrick causes the greatest crop losses which can range from 60 to 100%. After its detection in Egypt during the last half of 2009, it spread quickly to all provinces in the country. We aiming to propose a sustainable control program for this devastating pest. In this research we tested three groups of control agents. The first was microbial and natural, the second - plant extracts and the third - chemical insecticides. Our results showed that the impact of T. absoluta can be greatly reduced by the use of sustainable control measures represented by different insecticide groups. Bioassay experiments showed that this devastating pest can be controlled with some compounds that give high mortality rates. Of these compounds, spinosad and Beauveria bassiana, microbial control agents, followed by azadirachtin, gave the best results in controlling T. absoluta. Of the chemical insecticides, lambda-cyhalotrin was the most effective, followed by lufenuron and profenofos. In conclusion we encourage farmers to use microbial and natural control measures in combating the tomato leafminer, T. absoluta, in Integrated Pest Mangement (IPM programs.

  19. Uso potencial de agentes clarificantes y desinfectantes de origen natural para el tratamiento integral del agua caracterizado por pisos térmicos

    OpenAIRE

    Ramírez Arcila, Hildebrando; Jaramillo, Jhoan

    2014-01-01

    The article presents a methodology that will be used for the research project approved by the Research Development Committee (Comité para el Desarrollo de la Investigación, Conadi) in 2014, entitled “Potential Use of Clarifying And Disinfecting Agents of Natural Origin for Comprehensive Water Treatment Characterized by Thermal Floors” (“Uso potencial de agentes clarificantes y desinfectantes de origen natural para el tratamiento integral del agua caracterizado por pisos térmicos”), which is b...

  20. Socio-Ecohydrologic Agents And Services: Integrating Human And Natural Components To Address Coupled System Resilience

    Science.gov (United States)

    Pavao-zuckerman, M.; Pope, A.; Chan, D.; Curl, K.; Gimblett, H. R.; Hough, M.; House-Peters, L.; Lee, R.; Scott, C. A.

    2012-12-01

    Riparian corridors in arid regions are highly valued for their relative scarcity, and because healthy riparian systems support high levels of biodiversity, can meet human demand for water and water-related resources and functions. Our team is taking a transdiciplinary social-ecological systems approach to assessing riparian corridor resilience in two watersheds (the San Pedro River in USA and Mexico, and the Rio San Miguel in Mexico) through a project funded by the NSF CNH program ("Strengthening Resilience of Arid Region Riparian Corridors"). Multiple perspectives are integrated in the project, including hydrology, ecology, institutional dynamics, and decision making (at the level of both policy and individual choice), as well as the perspectives of various stakeholder groups and individuals in the watersheds. Here we discuss initial findings that center around linking changes in ecohydrology and livelihoods related to decisions in response to climatic, ecological, and social change. The research team is implementing two approaches to integrate the disparate disciplines participating in the research (and the varied perspectives among the stakeholders in this binational riparian context): (1) ecosystem service assessment, and (2) agent based model simulation. We are developing an ecosystem service perspective that provides a bridge between ecological dynamics in the landscape and varied stakeholder perspectives on the implications of ecohydrology for well-being (economic, cultural, ecological). Services are linked on one hand to the spatial patterns of traits of individuals within species (allowing a more predictive application of ecosystem services as they vary with community change in time), and to stakeholder perspectives (facilitating integration of ecosystem services into our understanding of decision making processes) in a case study in the San Pedro River National Conservation Area. The agent- based model (ABM) approach incorporates the influence of human

  1. Phyllanthus wightianus Müll. Arg.: A Potential Source for Natural Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    D. Natarajan

    2014-01-01

    Full Text Available Phyllanthus wightianus belongs to Euphorbiaceae family having ethnobotanical importance. The present study deals with validating the antimicrobial potential of solvent leaf extracts of P. wightianus. 11 human bacterial pathogens (Bacillus subtilis, Streptococcus pneumoniae, Staphylococcus epidermidis, Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhimurium, Escherichia coli, Shigella flexneri, Proteus vulgaris, and Serratia marcescens and 4 fungal pathogens (Candida albicans, Cryptococcus neoformans, Mucor racemosus, and Aspergillus niger were also challenged with solvent leaf extracts usingagar well and disc diffusion methods. Further, identification of the active component present in the bioactive extract was done using GC-MS analysis. Results show that all extracts exhibited broad spectrum (6–29 mm of antibacterial activity on most of the tested organisms. The results highlight the fact that the well in agar method was more effective than disc diffusion method. Significant antimicrobial activity was detected in methanol extract against S. pneumoniae (29 mm with MIC and MBC values of 15.62 μg/mL. GC-MS analysis revealed that 29 bioactive constituents were present in methanolic extract of P. wightianus, of which 9,12-octadecaenioic acid (peak area 22.82%; RT-23.97 and N-hexadecanoic acid (peak area 21.55% RT-21.796 are the major compounds. The findings of this study show that P. wightianus extracts may be used as an anti-infective agent in folklore medicine.

  2. Discovery and biological evaluation of the novel naturally occurring diterpene pepluanone as antiinflammatory agent.

    Science.gov (United States)

    Corea, Gabriella; Fattorusso, Ernesto; Lanzotti, Virginia; Di Meglio, Paola; Maffia, Pasquale; Grassia, Gianluca; Ialenti, Armando; Ianaro, Angela

    2005-11-03

    From the whole plant of Euphorbia peplus L., a new diterpene based on a rare pepluane skeleton, named pepluanone (1), was isolated together with a known pepluane diterpene (2). The stereostructure of pepluanone was determined on the basis of an extensive NMR study, MS data, and chemical reaction. The ability of these compounds to act as antiinflammatory agents has been evaluated for the first time by in vivo tests on carrageenin-induced rat paw edema, an experimental model of acute inflammation. Comparison of the bioactivity of pepluanone and compound 2 in terms of chemical structure, evidenced the high efficiency of pepluanone and the absence of appreciable activity for compound 2, thus giving a first insight into the structure-activity relationship. Further in vitro experiments performed on pepluanone let us hypothesize that its activity could be explained in reducing the production of nitric oxide, prostaglandin E(2), and TNF-alpha by inhibiting the expression of inducible nitric oxide synthase, cyclooxygenase-2, and TNF-alpha mRNA through the down-regulation of NF-kappaB binding activity.

  3. Natural therapeutic agents for neurodegenerative diseases from a traditional herbal medicine Pongamia pinnata (L.) Pierre.

    Science.gov (United States)

    Li, Jiayuan; Jiang, Zhe; Li, Xuezheng; Hou, Yue; Liu, Fen; Li, Ning; Liu, Xia; Yang, Lihua

    2015-01-01

    Neurodegenerative diseases are associated with neuroinflammation, manifested by over-production of nitric oxide (NO) by microglial cells. Now there still lack effective treatment and prevention for the neurodegenerative diseases. Concerning neuroinflammation mediated by microglia cell, bioactivity-guided phytochemical research of Pongamia pinnata (L.) Pierre was performed in this study. A new chlorinated flavonoid, 2′,6′-dichlore-3′, 5′-dimethoxy-[2′′,3′′:7,8]-furanoflavone (1) was identified together with 29 known compounds, including flavonoids (compounds 2-17), isoflavonoids (compounds 18-23), chalcones (compounds 24-25), flavonones (compounds 26-27), triterpenes (28-29) and alkaloid (30) from the effective dichloride methane extract of dry stem of P. pinnata (L.) Pierre. Their structures were elucidated by physicochemical and spectral methods. The anti-neuroinflammatory activities were assayed in BV-2 cells by assessing LPS-induced NO production. Then pongaglabol methyl ether (2), lonchocarpin (24) and glabrachromene II (25) were selected as potential therapeutic agents for neurodegenerative diseases because of their significant anti-neuroinflammatory activities. Furthermore, the characteristics of structure type existing in P. pinnata (L.) Pierre and brief SAR were summarized, respectively.

  4. SuperSweet--a resource on natural and artificial sweetening agents.

    Science.gov (United States)

    Ahmed, Jessica; Preissner, Saskia; Dunkel, Mathias; Worth, Catherine L; Eckert, Andreas; Preissner, Robert

    2011-01-01

    A vast number of sweet tasting molecules are known, encompassing small compounds, carbohydrates, d-amino acids and large proteins. Carbohydrates play a particularly big role in human diet. The replacement of sugars in food with artificial sweeteners is common and is a general approach to prevent cavities, obesity and associated diseases such as diabetes and hyperlipidemia. Knowledge about the molecular basis of taste may reveal new strategies to overcome diet-induced diseases. In this context, the design of safe, low-calorie sweeteners is particularly important. Here, we provide a comprehensive collection of carbohydrates, artificial sweeteners and other sweet tasting agents like proteins and peptides. Additionally, structural information and properties such as number of calories, therapeutic annotations and a sweetness-index are stored in SuperSweet. Currently, the database consists of more than 8000 sweet molecules. Moreover, the database provides a modeled 3D structure of the sweet taste receptor and binding poses of the small sweet molecules. These binding poses provide hints for the design of new sweeteners. A user-friendly graphical interface allows similarity searching, visualization of docked sweeteners into the receptor etc. A sweetener classification tree and browsing features allow quick requests to be made to the database. The database is freely available at: http://bioinformatics.charite.de/sweet/.

  5. Natural lignans from Arctium lappa as antiaging agents in Caenorhabditis elegans.

    Science.gov (United States)

    Su, Shan; Wink, Michael

    2015-09-01

    Arctium lappa is a well-known traditional medicinal plant in China (TCM) and Europe that has been used for thousands of years to treat arthritis, baldness or cancer. The plant produces lignans as secondary metabolites, which have a wide range of bioactivities. Yet, their antiaging potential has not been explored. In this study, we isolated six lignans from A. lappa seeds, namely arctigenin, matairesinol, arctiin, (iso)lappaol A, lappaol C, and lappaol F. The antioxidant and antiaging properties of the isolated lignans were studied using Caenorhabditis elegans as a relevant animal model. All lignans at concentrations of 10 and 100 μM significantly extended the mean life span of C. elegans. The strongest effect was observed with matairesinol, which at a concentration of 100 μM extended the life span of worms by 25%. Additionally, we observed that five lignans are strong free radical-scavengers in vitro and in vivo and all lignans can improve survival of C. elegans under oxidative stress. Furthermore, the lignans can induce the nuclear translocation of the transcription factor DAF-16 and up-regulate its expression, suggesting that a possible underlying mechanism of the observed longevity-promoting activity of lignans depends on DAF-16 mediated signaling pathway. All lignans up-regulated the expression of jnk-1, indicating that lignans may promote the C. elegans longevity and stress resistance through a JNK-1-DAF-16 cascade. Our study reports new antiaging activities of lignans, which might be candidates for developing antiaging agents.

  6. Natural populations of Trypanosoma cruzi, the agent of Chagas disease, have a complex multiclonal structure

    Energy Technology Data Exchange (ETDEWEB)

    Tibayrenc, M.; Ward, P.; Moya, A.; Ayala, F.J.

    1986-01-01

    The authors have studied 15 gene loci coding for enzymes in 121 Trypanosoma cruzi stocks from a wide geographic range - from the US and Mexico to Chile and southern Brazil. T.cruzi is diploid but reproduction is basically clonal, with very little if any sexuality remaining at present. They have identified 43 different clones by their genetic composition; the same genetic clone is often found in very distant places and in diverse hosts. There is much genetic heterogeneity among the different clones, and they cannot be readily classified into a few discrete groups that might represent natural taxa. These findings imply that the biological and medical characteristics need to be ascertained separately for each natural clone. The evidence indicates that clonal evolution is very ancient in T.cruzi. The authors propose two alternative hypotheses concerning the relationship between the biochemical diversity and the heterogeneity in other biological and medical characteristics of T. cruzi. One hypothesis is that the degree of diversity between strains simply reflects the time elapsed since their last common ancestor. The second hypothesis is that biological and medical heterogeneity is recent and reflects adaptation to different transmission cycles. A decision between the two hypotheses can be reached with appropriate studies, with important medical consequences.

  7. Casbane Diterpene as a Promising Natural Antimicrobial Agent against Biofilm-Associated Infections

    Directory of Open Access Journals (Sweden)

    Edson Holanda Teixeira

    2010-12-01

    Full Text Available Croton nepetaefolius is a native plant from northeastern Brazil that belongs to the Euphorbiaceae family. The biological action of this plant has been extensively explored, being the secondary metabolites responsible for its properties alkaloids, diterpenes, and triterpenes. This study aimed to evaluate the ability of casbane diterpene (CD, isolated from the ethanolic extract of C. nepetaefolius, to inhibit microbial growth and biofilm formation of several clinical relevant species (bacteria and yeasts. It was found that CD possessed biocidal and biostatic activity against the majority of the species screened, with minimal active concentrations ranging between 125 and 500 µg/mL. In addition, it was observed that biofilm formation was inhibited even when the planktonic growth was not significantly affected. In conclusion, CD showed potential to be a natural tool for the treatment of diseases caused by different infectious microorganisms.

  8. Seagrass as a potential source of natural antioxidant and anti-inflammatory agents.

    Science.gov (United States)

    Yuvaraj, N; Kanmani, P; Satishkumar, R; Paari, A; Pattukumar, V; Arul, V

    2012-04-01

    Halophila spp. is a strong medicine against malaria and skin diseases and is found to be very effective in early stages of leprosy. Seagrasses are nutraceutical in nature and therefore of importance as food supplements. The antibacterial, antioxidant, and anti-inflammatory activities of Halophila ovalis R. Br. Hooke (Hydrocharitaceae) methanol extract were investigated and the chemical constituents of purified fractions were analyzed. Plant materials were collected from Pondicherry coastal line, and antimicrobial screening of crude extract, and purified fractions was carried out by the disc diffusion method and the minimum inhibitory concentration (MICs) of the purified fractions and reference antibiotics were determined by microdilution method. Antioxidant and anti-inflammatory activities were investigated in vitro. Chemical constituents of purified fractions V and VI were analyzed by gas chromatography-mass spectrometry (GC-MS), and the phytochemicals were quantitatively determined. Methanol extract inhibited the growth of Bacillus cereus at a minimum inhibitory concentration of 50 µg/mL and other Gram-negative pathogens at 75 µg/ml, except Vibrio vulnificus. Reducing power and total antioxidant level increased with increasing extract concentration. H. ovalis exhibited strong scavenging activity on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals at IC(50) of 0.13 and 0.65 mg/mL, respectively. Methanol extract of H. ovalis showed noticeable anti-inflammatory activity at IC(50) of 78.72 µg/mL. The GC-MS analysis of H. ovalis revealed the presence of triacylglycerols as major components in purified fractions. Quantitative analysis of phytochemicals revealed that phenols are rich in seagrass H. ovalis. These findings demonstrated that the methanol extract of H. ovalis exhibited appreciable antibacterial, noticeable antioxidant, and anti-inflammatory activities, and thus could be use as a potential source for natural health products.

  9. Agents, Individuals, and Networks: Modeling Methods to Inform Natural Resource Management in Regional Landscapes

    Directory of Open Access Journals (Sweden)

    Lael Parrott

    2012-09-01

    Full Text Available Landscapes are complex systems. Landscape dynamics are the result of multiple interacting biophysical and socioeconomic processes that are linked across a broad range of spatial, temporal, and organizational scales. Understanding and describing landscape dynamics poses enormous challenges and demands the use of new multiscale approaches to modeling. In this synthesis article, we present three regional systems--i.e., a forest system, a marine system, and an agricultural system--and describe how hybrid, bottom-up modeling of these systems can be used to represent linkages across scales and between subsystems. Through the use of these three examples, we describe how modeling can be used to simulate emergent system responses to different conservation policy and management scenarios from the bottom up, thereby increasing our understanding of important drivers and feedback loops within a landscape. The first case study involves the use of an individual-based modeling approach to simulate the effects of forest harvesting on the movement patterns of large mammals in Canada's boreal forest and the resulting emergent population dynamics. This model is being used to inform forest harvesting and management guidelines. The second case study combines individual and agent-based approaches to simulate the dynamics of individual boats and whales in a marine park. This model is being used to inform decision-makers on how to mitigate the impacts of maritime traffic on whales in the Saint Lawrence Estuary in eastern Canada. The third example is a case study of biodiversity conservation efforts on the Eyre Peninsula, South Australia. In this example, the social-ecological system is represented as a complex network of interacting components. Methods of network analysis can be used to explore the emergent responses of the system to changes in the network structure or configuration, thus informing managers about the resilience of the system. These three examples

  10. New Biofunctional Loading of Natural Antimicrobial Agent in Biodegradable Polymeric Films for Biomedical Applications

    Science.gov (United States)

    Ghafoor, Bakhtawar; Ansari, Umar; Bhatti, Muhammad Faraz; Akhtar, Hafsah; Darakhshan, Fatima

    2016-01-01

    The study focuses on the development of novel Aloe vera based polymeric composite films and antimicrobial suture coatings. Polyvinyl alcohol (PVA), a synthetic biocompatible and biodegradable polymer, was combined with Aloe vera, a natural herb used for soothing burning effects and cosmetic purposes. The properties of these two materials were combined together to get additional benefits such as wound healing and prevention of surgical site infections. PVA and Aloe vera were mixed in a fixed quantity to produce polymer based films. The films were screened for antibacterial and antifungal activity against bacterial (E. coli, P. aeruginosa) and fungal strains (Aspergillus flavus and Aspergillus tubingensis) screened. Aloe vera based PVA films showed antimicrobial activity against all the strains; the lowest Aloe vera concentration (5%) showed the highest activity against all the strains. In vitro degradation and release profile of these films was also evaluated. The coating for sutures was prepared, in vitro antibacterial tests of these coated sutures were carried out, and later on in vivo studies of these coated sutures were also performed. The results showed that sutures coated with Aloe vera/PVA coating solution have antibacterial effects and thus have the potential to be used in the prevention of surgical site infections and Aloe vera/PVA based films have the potential to be used for wound healing purposes. PMID:27965710

  11. [Evaluation of pharmacopoeia methods for determination of antimicrobial agents, especially of natural substances].

    Science.gov (United States)

    Brantner, A

    1997-01-01

    Microbiological assays referring to antibiotics were first mentioned in 1955 in the US Pharmacopedia XV and in the Pharmacopedia of India I. In the pharmacopedias two general methods are employed: The first group of methods is grounded on diffusion (disc assay, cylinder-plate and hole-plate assay), the second one is based on the determination of optical density (turbidimetric method). Both methods involve certain problems, particularly with respect to the testing of low-active natural substances. In the course of our investigations those test methods were evaluated and the advantages and disadvantages discussed. The methods were compared to test systems not being described in the pharmacopedias (microdilution test, bioautographic TLC assay). In addition to that we examined spectrophotometrically (OD580nm) the influence of an antimicrobial substance and of a solutizer on the bacterial growth. Tetracycline hydrochloride was used as reference and naringenin as test substance. The results were analyzed with statistical methods cited in the pharmacopedias, e.g. straight-line method and compared to other common methods, e.g. analysis of variance.

  12. CFTR chloride channel is a molecular target of the natural cancer preventive agent resveratrol.

    Science.gov (United States)

    Yang, Shuang; Yu, B O; Sui, Yujie; Zhang, Yaofang; Wang, Xue; Hou, Shuguang; Ma, Tonghui; Yang, Hong

    2013-09-01

    The naturally occurring polyphenol compound resveratrol (RES) has been receiving wide attention because of its variety of health benefits and favourable biological activities. Previous studies have shown that RES could induce intestinal chloride secretion in mouse jejunum and stimulate cAMP-dependent Cl- secretion in T84, primary cultured murine nasal septal and human sinonasal epithelial cells, but the precise molecular target is not clear. We therefore tested the hypothesis that RES may stimulate the activity of cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. Using cell-based fluorescent assays, transepithelial short-circuit current measurements and excised inside-out patch-clamp analysis; we found that RES dose-dependently potentiate CFTR Cl- channel activities, which was reversed by CFTR inhibitors CFTR(inh)-172 and GlyH101. Transepithelial Cl- secretion by CFTR-expressing FRT cells was stimulated by RES with half maximal concentration -80 microM. Intracellular cAMP content was not elevated by RES in FRT cells. Excised inside-out patch-clamp analysis indicated that RES significantly increased the chloride currents of CFTR. In ex vivo studies, RES stimulated the transmucosal chloride current of rat colon by short-circuit current assay. These data suggested that CFTR is a molecular target of RES. Our findings add a new molecular target to RES, and RES may represent a novel class of therapeutic lead compounds in treating CFTR-related diseases including CF and habitual constipation.

  13. Identification of a new degradation product of the antifouling agent Irgarol 1051 in natural samples

    Science.gov (United States)

    Ferrer, I.; Barcelo, D.

    2001-01-01

    A main degradation product of Irgarol [2-(methylthio)-4-(tert-butylamino)-6-(cyclopropylamino)-s-triazine], one of the most widely used compounds in antifouling paints, was detected at trace levels in seawater and sediment samples collected from several marinas on the Mediterranean coast. This degradation product was identified as 2-methylthio-4-tert-butylamino-s-triazine. The unequivocal identification of this compound in seawater samples was carried out by solid-phase extraction (SPE) coupled on-line with liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS). SPE was carried out by passing 150 ml of seawater sample through a cartridge containing a polymeric phase (PLRP-s), with recoveries ranging from 92 to 108% (n=5). Using LC-MS detection in positive ion mode, useful structural information was obtained by increasing the fragmentor voltage, thus permitting the unequivocal identification of this compound in natural samples. Method detection limits were in the range of 0.002 to 0.005 ??g/l. Overall, the combination of on-line SPE and LC-APCI-MS represents an important advance in environmental analysis of herbicide degradation products in seawater, since it demonstrates that trace amounts of new polar metabolites may be determined rapidly. This paper reports the LC-MS identification of the main degradation product of Irgarol in seawater and sediment samples. ?? 2001 Elsevier Science B.V. All rights reserved.

  14. Effect of tea tree (Melaleuca alternifolia) oil as a natural antimicrobial agent in lipophilic formulations.

    Science.gov (United States)

    Mantil, Elisabeth; Daly, Grace; Avis, Tyler J

    2015-01-01

    There has been increased interest surrounding the use of tea tree oil (TTO) as a natural antimicrobial. In this study, the antimicrobial activity of TTO and its components were investigated in vitro and in a predominantly lipid-based personal care formulation. In vitro, TTO showed minimal inhibitory concentrations of 0.2% (for Saccharomyces cerevisiae and Pythium sulcatum), 0.4% (for Escherichia coli, Bacillus subtilis, and Rhizopus stolonifer), and 0.8% (for Botrytis cinerea). TTO at 0.08%-0.8% was often as efficient as parabens. Comparison of the antimicrobial activities of TTO components showed that terpinen-4-ol and γ-terpinene were generally most effective in inhibiting microbial growth. TTO activity in a personal care product was evaluated through air and water exposure, artificial inoculation, and shelf life studies. While TTO did not increase shelf life of unopened products, it decreased microbial load in products exposed to water and air. Results from this study support that antimicrobial activity of TTO can be attributed to varying levels of its components and that low levels of TTO were effective in reducing microbial growth during the use of the product. This study showed that TTO can act as a suitable preservative system within an oil-based formulation.

  15. Light-responsive polymer microcapsules as delivery systems for natural active agents

    Energy Technology Data Exchange (ETDEWEB)

    Bizzarro, Valentina; Carfagna, Cosimo; Cerruti, Pierfrancesco [Institute for Polymers, Composites and Biomaterials (IPCB-CNR), Via Campi Flegrei, 34, 80078 Pozzuoli, NA (Italy); Marturano, Valentina; Ambrogi, Veronica [Department of Chemical, Materials and Production Engineering (DICMAPI), University of Naples “Federico II”, P. le Tecchio, 80, 80125 Napoli (Italy); Institute for Polymers, Composites and Biomaterials (IPCB-CNR), Via Campi Flegrei, 34, 80078 Pozzuoli, NA (Italy)

    2016-05-18

    In this work we report the preparation and the release behavior of UV-responsive polymeric microcapsules containing essential oils as a core. The oil acted also as a monomer solvent during polymerization. Accordingly, the potentially toxic organic solvent traditionally used was replaced with a natural active substance, resulting in a more sustainable functional system. Polymer shell was based on a lightly cross-linked polyamide containing UV-sensitive azobenzene moieties in the main chain. The micro-sized capsules were obtained via interfacial polycondensation in o/w emulsion, and their mean size was measured via Dynamic Light Scattering. Shape and morphology were analyzed through Scanning Electron and Optical Microscopy. UV-responsive behavior was evaluated via spectrofluorimetry, by assessing the release kinetics of a fluorescent probe molecule upon UV light irradiation (λ{sub max}=360 nm). The irradiated samples showed an increase in fluorescence intensity, in accordance with the increase of the probe molecule concentration in the release medium. As for the un-irradiated sample, no changes could be detected demonstrating the effectiveness of the obtained releasing system.

  16. New Biofunctional Loading of Natural Antimicrobial Agent in Biodegradable Polymeric Films for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Bakhtawar Ghafoor

    2016-01-01

    Full Text Available The study focuses on the development of novel Aloe vera based polymeric composite films and antimicrobial suture coatings. Polyvinyl alcohol (PVA, a synthetic biocompatible and biodegradable polymer, was combined with Aloe vera, a natural herb used for soothing burning effects and cosmetic purposes. The properties of these two materials were combined together to get additional benefits such as wound healing and prevention of surgical site infections. PVA and Aloe vera were mixed in a fixed quantity to produce polymer based films. The films were screened for antibacterial and antifungal activity against bacterial (E. coli, P. aeruginosa and fungal strains (Aspergillus flavus and Aspergillus tubingensis screened. Aloe vera based PVA films showed antimicrobial activity against all the strains; the lowest Aloe vera concentration (5% showed the highest activity against all the strains. In vitro degradation and release profile of these films was also evaluated. The coating for sutures was prepared, in vitro antibacterial tests of these coated sutures were carried out, and later on in vivo studies of these coated sutures were also performed. The results showed that sutures coated with Aloe vera/PVA coating solution have antibacterial effects and thus have the potential to be used in the prevention of surgical site infections and Aloe vera/PVA based films have the potential to be used for wound healing purposes.

  17. Natural health products that inhibit angiogenesis: a potential source for investigational new agents to treat cancer-Part 2.

    Science.gov (United States)

    Sagar, S M; Yance, D; Wong, R K

    2006-06-01

    The herbalist has access to hundreds of years of observational data on the anticancer activity of many herbs. Laboratory studies are expanding the clinical knowledge that is already documented in traditional texts. The herbs that are traditionally used for anti-cancer treatment and that are anti-angiogenic through multiple interdependent processes (including effects on gene expression, signal processing, and enzyme activities) include Artemisia annua (Chinese wormwood), Viscum album (European mistletoe), Curcuma longa (curcumin), Scutellaria baicalensis (Chinese skullcap), resveratrol and proanthocyanidin (grape seed extract), Magnolia officinalis (Chinese magnolia tree), Camellia sinensis (green tea), Ginkgo biloba, quercetin, Poria cocos, Zingiber officinalis (ginger), Panax ginseng, Rabdosia rubescens hora (Rabdosia), and Chinese destagnation herbs. Natural health products target molecular pathways other than angiogenesis, including epidermal growth factor receptor, the HER2/neu gene, the cyclo-oxygenase-2 enzyme, the nuclear factor kappa-B transcription factor, the protein kinases, the Bcl-2 protein, and coagulation pathways. Quality assurance of appropriate extracts is essential prior to embarking upon clinical trials. More data are required on dose-response, appropriate combinations, and potential toxicities. Given the multiple effects of these agents, their future use for cancer therapy probably lies in synergistic combinations. During active cancer therapy they should generally be evaluated in combination with chemotherapy and radiation. In this role, they act as modifiers of biologic response or as adaptogens, potentially enhancing the efficacy of the conventional therapies or reducing toxicity. Their effectiveness may be increased when multiple agents are used in optimal combinations. New designs for trials to demonstrate activity in human subjects are required. Although controlled trials may be preferable, smaller studies with appropriate endpoints and

  18. Natural health products that inhibit angiogenesis: a potential source for investigational new agents to treat cancer—Part 2

    Science.gov (United States)

    Sagar, S.M.; Yance, D.; Wong, R.K.

    2006-01-01

    The herbalist has access to hundreds of years of observational data on the anticancer activity of many herbs. Laboratory studies are expanding the clinical knowledge that is already documented in traditional texts. The herbs that are traditionally used for anti-cancer treatment and that are anti-angiogenic through multiple interdependent processes (including effects on gene expression, signal processing, and enzyme activities) include Artemisia annua (Chinese wormwood), Viscum album (European mistletoe), Curcuma longa (curcumin), Scutellaria baicalensis (Chinese skullcap), resveratrol and proanthocyanidin (grape seed extract), Magnolia officinalis (Chinese magnolia tree), Camellia sinensis (green tea), Ginkgo biloba, quercetin, Poria cocos, Zingiber officinalis (ginger), Panax ginseng, Rabdosia rubescens hora (Rabdosia), and Chinese destagnation herbs. Natural health products target molecular pathways other than angiogenesis, including epidermal growth factor receptor, the HER2/neu gene, the cyclo-oxygenase-2 enzyme, the nuclear factor kappa-B transcription factor, the protein kinases, the Bcl-2 protein, and coagulation pathways. Quality assurance of appropriate extracts is essential prior to embarking upon clinical trials. More data are required on dose–response, appropriate combinations, and potential toxicities. Given the multiple effects of these agents, their future use for cancer therapy probably lies in synergistic combinations. During active cancer therapy they should generally be evaluated in combination with chemotherapy and radiation. In this role, they act as modifiers of biologic response or as adaptogens, potentially enhancing the efficacy of the conventional therapies or reducing toxicity. Their effectiveness may be increased when multiple agents are used in optimal combinations. New designs for trials to demonstrate activity in human subjects are required. Although controlled trials may be preferable, smaller studies with appropriate endpoints and

  19. Natural products as anti-glycation agents: possible therapeutic potential for diabetic complications.

    Science.gov (United States)

    Elosta, Abdulhakim; Ghous, Tahseen; Ahmed, Nessar

    2012-03-01

    Diabetes mellitus is characterised by hyperglycaemia, lipidaemia and oxidative stress and predisposes affected individuals to long-term complications afflicting the eyes, skin, kidneys, nerves and blood vessels. Increased protein glycation and the subsequent build-up of tissue advanced glycation endproducts (AGEs) contribute towards the pathogenesis of diabetic complications. Protein glycation is accompanied by generation of free radicals through autoxidation of glucose and glycated proteins and via interaction of AGEs with their cell surface receptors (referred to as RAGE). Glycationderived free radicals can damage proteins, lipids and nucleic acids and contribute towards oxidative stress in diabetes. There is interest in compounds with anti-glycation activity as they may offer therapeutic potential in delaying or preventing the onset of diabetic complications. Although many different compounds are under study, only a few have successfully entered clinical trials but none have yet been approved for clinical use. Whilst the search for new synthetic inhibitors of glycation continues, little attention has been paid to anti-glycation compounds from natural sources. In the last few decades the traditional system of medicine has become a topic of global interest. Various studies have indicated that dietary supplementation with combined anti-glycation and antioxidant nutrients may be a safe and simple complement to traditional therapies targeting diabetic complications. Data for forty two plants/constituents studied for anti-glycation activity is presented in this review and some commonly used medicinal plants that possess anti-glycation activity are discussed in detail including their active ingredients, mechanism of action and therapeutic potential.

  20. Natural health products that inhibit angiogenesis: a potential source for investigational new agents to treat cancer—Part 1

    Science.gov (United States)

    Sagar, S.M.; Yance, D.; Wong, R.K.

    2006-01-01

    An integrative approach for managing a patient with cancer should target the multiple biochemical and physiologic pathways that support tumour development and minimize normal-tissue toxicity. Angiogenesis is a key process in the promotion of cancer. Many natural health products that inhibit angiogenesis also manifest other anticancer activities. The present article focuses on products that have a high degree of anti-angiogenic activity, but it also describes some of the many other actions of these agents that can inhibit tumour progression and reduce the risk of metastasis. Natural health products target molecular pathways other than angiogenesis, including epidermal growth factor receptor, the HER2/neu gene, the cyclooxygenase-2 enzyme, the nuclear factor kappa-B transcription factor, the protein kinases, the Bcl-2 protein, and coagulation pathways. The herbs that are traditionally used for anticancer treatment and that are anti-angiogenic through multiple interdependent processes (including effects on gene expression, signal processing, and enzyme activities) include Artemisia annua (Chinese wormwood), Viscum album (European mistletoe), Curcuma longa (curcumin), Scutellaria baicalensis (Chinese skullcap), resveratrol and proanthocyanidin (grape seed extract), Magnolia officinalis (Chinese magnolia tree), Camellia sinensis (green tea), Ginkgo biloba, quercetin, Poria cocos, Zingiber officinalis (ginger), Panax ginseng, Rabdosia rubescens hora (Rabdosia), and Chinese destagnation herbs. Quality assurance of appropriate extracts is essential prior to embarking upon clinical trials. More data are required on dose–response, appropriate combinations, and potential toxicities. Given the multiple effects of these agents, their future use for cancer therapy probably lies in synergistic combinations. During active cancer therapy, they should generally be evaluated in combination with chemotherapy and radiation. In this role, they act as modifiers of biologic response or

  1. Natural health products that inhibit angiogenesis: a potential source for investigational new agents to treat cancer-Part 1.

    Science.gov (United States)

    Sagar, S M; Yance, D; Wong, R K

    2006-02-01

    An integrative approach for managing a patient with cancer should target the multiple biochemical and physiologic pathways that support tumour development and minimize normal-tissue toxicity. Angiogenesis is a key process in the promotion of cancer. Many natural health products that inhibit angiogenesis also manifest other anticancer activities. The present article focuses on products that have a high degree of anti-angiogenic activity, but it also describes some of the many other actions of these agents that can inhibit tumour progression and reduce the risk of metastasis. Natural health products target molecular pathways other than angiogenesis, including epidermal growth factor receptor, the HER2/neu gene, the cyclooxygenase-2 enzyme, the nuclear factor kappa-B transcription factor, the protein kinases, the Bcl-2 protein, and coagulation pathways. The herbs that are traditionally used for anticancer treatment and that are anti-angiogenic through multiple interdependent processes (including effects on gene expression, signal processing, and enzyme activities) include Artemisia annua (Chinese wormwood), Viscum album (European mistletoe), Curcuma longa (curcumin), Scutellaria baicalensis (Chinese skullcap), resveratrol and proanthocyanidin (grape seed extract), Magnolia officinalis (Chinese magnolia tree), Camellia sinensis (green tea), Ginkgo biloba, quercetin, Poria cocos, Zingiber officinalis (ginger), Panax ginseng, Rabdosia rubescens hora (Rabdosia), and Chinese destagnation herbs. Quality assurance of appropriate extracts is essential prior to embarking upon clinical trials. More data are required on dose-response, appropriate combinations, and potential toxicities. Given the multiple effects of these agents, their future use for cancer therapy probably lies in synergistic combinations. During active cancer therapy, they should generally be evaluated in combination with chemotherapy and radiation. In this role, they act as modifiers of biologic response or as

  2. Plant-Derived Antimalarial Agents: New Leads and Efficient Phytomedicines. Part II. Non-Alkaloidal Natural Products

    Directory of Open Access Journals (Sweden)

    Alaíde Braga de Oliveira

    2009-08-01

    Full Text Available Malaria is still the most destructive and dangerous parasitic infection in many tropical and subtropical countries. The burden of this disease is getting worse, mainly due to the increasing resistance of Plasmodium falciparum against the widely available antimalarial drugs. There is an urgent need for new, more affordable and accessible antimalarial agents possessing original modes of action. Natural products have played a dominant role in the discovery of leads for the development of drugs to treat human diseases, and this fact anticipates that new antimalarial leads may certainly emerge from tropical plant sources. This present review covers most of the recently-published non-alkaloidal natural compounds from plants with antiplasmodial and antimalarial properties, belonging to the classes of terpenes, limonoids, flavonoids, chromones, xanthones, anthraquinones, miscellaneous and related compounds, besides the majority of papers describing antiplasmodial crude extracts published in the last five years not reviewed before. In addition, some perspectives and remarks on the development of new drugs and phytomedicines for malaria are succinctly discussed.

  3. Understanding coupled natural and human systems on fire prone landscapes: integrating wildfire simulation into an agent based planning system.

    Science.gov (United States)

    Barros, Ana; Ager, Alan; Preisler, Haiganoush; Day, Michelle; Spies, Tom; Bolte, John

    2015-04-01

    Agent-based models (ABM) allow users to examine the long-term effects of agent decisions in complex systems where multiple agents and processes interact. This framework has potential application to study the dynamics of coupled natural and human systems where multiple stimuli determine trajectories over both space and time. We used Envision, a landscape based ABM, to analyze long-term wildfire dynamics in a heterogeneous, multi-owner landscape in Oregon, USA. Landscape dynamics are affected by land management policies, actors decisions, and autonomous processes such as vegetation succession, wildfire, or at a broader scale, climate change. Key questions include: 1) How are landscape dynamics influenced by policies and institutions, and 2) How do land management policies and actor decisions interact to produce intended and unintended consequences with respect to wildfire on fire-prone landscapes. Applying Envision to address these questions required the development of a wildfire module that could accurately simulate wildfires on the heterogeneous landscapes within the study area in terms of replicating historical fire size distribution, spatial distribution and fire intensity. In this paper we describe the development and testing of a mechanistic fire simulation system within Envision and application of the model on a 3.2 million fire prone landscape in central Oregon USA. The core fire spread equations use the Minimum Travel Time algorithm developed by M Finney. The model operates on a daily time step and uses a fire prediction system based on the relationship between energy release component and historical fires. Specifically, daily wildfire probabilities and sizes are generated from statistical analyses of historical fires in relation to daily ERC values. The MTT was coupled with the vegetation dynamics module in Envision to allow communication between the respective subsystem and effectively model fire effects and vegetation dynamics after a wildfire. Canopy and

  4. 新型天然抗菌试剂研究进展%Research Progress on New Natural Antimicrobial Agents

    Institute of Scientific and Technical Information of China (English)

    段丽丽; 阎红; 贾洪峰; 周凌洁

    2016-01-01

    随着人们对于食品安全的重视,食品防腐剂作为食品加工和保存中不可缺少的一部分也逐渐得到了广泛的关注。为了防止食物的腐败变质和延长保存时间,加工食品和需要保鲜的瓜果蔬菜等需要在制作加工和包装过程中添加一定的防腐剂来杀死微生物或者抑制微生物的生长来避免腐败。如何在食品加工和保存的过程中使用天然的抗菌试剂来替代传统的具有潜在毒害的化学防腐剂,是目前研究的热点。主要对目前已经研究发现的天然食品防腐剂进行综述,介绍天然食品抗菌剂的来源、分类和抗菌特性,阐释一些新型天然抗菌试剂的研究进展以及天然食品防腐剂研究存在的问题和未来的发展前景,以期能够对食品加工和保存过程中食品防腐剂的选择起到一定的指导作用。%As people pay more attention to food safety,food preservative as an integral part of the food processing and preservation gradually gains wide attention by people.In order to prevent food from decaying and prolong the shelf life,the processed foods and fresh fruits and vegetables need to add certain preservatives to kill microorganisms or inhibit the growth of microorganisms to avoid corruption during the process of making,processing and packaging.In recent years,it has been a hot topic research on finding new natural antimicrobial agents and trying to use them as substitutes of chemical additives which might be harmful to human health.Mainly review on the application of different kinds of natural antimicrobial agents and their source, classification and antimicrobial activity.Meanwhile,discuss about the research process on new natural antimicrobial products all over the world and the problems existed in the research and the development prospect of natural antimicrobial preservatives,in order to play a certain guidance role in the choice of food preservatives in the processing and

  5. Natural Products as Anti-HIV Agents and Role in HIV-Associated Neurocognitive Disorders (HAND): A Brief Overview.

    Science.gov (United States)

    Kurapati, Kesava Rao V; Atluri, Venkata S; Samikkannu, Thangavel; Garcia, Gabriella; Nair, Madhavan P N

    2015-01-01

    As the threat of Human Immunodeficiency Virus (HIV)/Acquired Immunodeficiency Syndrome (AIDS) persists to rise, effective drug treatments are required to treat the infected people. Even though combination antiretroviral therapy (cART) provides stable viral suppression, it is not devoid of undesirable side effects, especially in persons undergoing long-term treatment. The present therapy finds its limitations in the emergence of multidrug resistance and accordingly finding new drugs and novel targets is the need of the hour to treat the infected persons and further to attack HIV reservoirs in the body like brain, lymph nodes to achieve the ultimate goal of complete eradication of HIV and AIDS. Natural products such as plant-originated compounds and plant extracts have enormous potential to become drug leads with anti-HIV and neuroprotective activity. Accordingly, many research groups are exploring the biodiversity of the plant kingdom to find new and better anti-HIV drugs with novel mechanisms of action and for HIV-associated neurocognitive disorders (HAND). The basic challenge that still persists is to develop viral replication-targeted therapy using novel anti-HIV compounds with new mode of action, accepted toxicity and less resistance profile. Against this backdrop, the World Health Organization (WHO) suggested the need to evaluate ethno-medicines for the management of HIV/AIDS. Consequently, there is need to evaluate traditional medicine, particularly medicinal plants and other natural products that may yield effective and affordable therapeutic agents. Although there are a good number of reports on traditional uses of plants to treat various diseases, knowledge of herbal remedies used to manage HIV/AIDS and HAND are scanty, vague and not well documented. In this review, plant substances showing a promising action that is anti-HIV and HAND will be explored along with what they interact. Since some plant substances are also known to modulate several cellular

  6. Natural Products as Anti-HIV Agents and Role in HIV-Associated Neurocognitive Disorders (HAND: A Brief Overview

    Directory of Open Access Journals (Sweden)

    Kesava Rao Venkata Kurapati

    2016-01-01

    Full Text Available As the threat of Human Immunodeficiency Virus (HIV/Acquired Immunodeficiency Syndrome (AIDS persists to rise, effective drug treatments are required to treat the infected people. Even though combination antiretroviral therapy (cART provides stable viral suppression, it is not devoid of undesirable side effects, especially in persons undergoing long-term treatment. The present therapy finds its limitations in the emergence of multidrug resistance and accordingly finding new drugs and novel targets is the need of the hour to treat the infected persons and further to attack HIV reservoirs in the body like brain, lymph nodes to achieve the ultimate goal of complete eradication of HIV and AIDS. Natural products such as plant-originated compounds and plant extracts have enormous potential to become drug leads with anti-HIV and neuroprotective activity. Accordingly, many research groups are exploring the biodiversity of the plant kingdom to find new and better anti-HIV drugs with novel mechanisms of action and for HIV-associated neurocognitive disorders (HAND. The basic challenge that still persists is to develop viral replication-targeted therapy using novel anti-HIV compounds with new mode of action, accepted toxicity and less resistance profile. Against this backdrop, the World Health Organization (WHO suggested the need to evaluate ethno-medicines for the management of HIV/AIDS. Consequently, there is need to evaluate traditional medicine, particularly medicinal plants and other natural products that may yield effective and affordable therapeutic agents. Although there are a good number of reports on traditional uses of plants to treat various diseases, knowledge of herbal remedies used to manage HIV/AIDS and HAND are scanty, vague and not well documented. In this review, plant substances showing a promising action that is anti-HIV and HAND will be explored along with what they interact. Since some plant substances are also known to modulate

  7. Analysis of the heavy oil production technology effectiveness using natural thermal convection with heat agent recirculation method in reservoirs with varying initial water saturation

    Science.gov (United States)

    Osnos, V. B.; Kuneevsky, V. V.; Larionov, V. M.; Saifullin, E. R.; Gainetdinov, A. V.; Vankov, Yu V.; Larionova, I. V.

    2017-01-01

    The method of natural thermal convection with heat agent recirculation (NTC HAR) in oil reservoirs is described. The analysis of the effectiveness of this method for oil reservoir heating with the values of water saturation from 0 to 0.5 units is conducted. As the test element Ashalchinskoye oil field is taken. CMG STARS software was used for calculations. Dynamics of cumulative production, recovery factor and specific energy consumption per 1 m3 of crude oil produced in the application of the heat exchanger with heat agent in cases of different initial water saturation are defined and presented as graphs.

  8. 鱼藤素对斑马鱼胚胎中细胞周期蛋白D1基因下调的作用:整胚原位杂交检测%Deguelin down-regulates the expression of cyclin D1 gene in zebrafish embroys through the whole mount in situ hybridization

    Institute of Scientific and Technical Information of China (English)

    海洋; 吴新荣

    2015-01-01

    BACKGROUND:In the early development of zebrafish embryos, cels divide and proliferate rapidly, but low concentration of deguelin can delay the development of zebrafish embryos. OBJECTIVE:To observe the effect of different concentrations of deguelin on cyclin D1 gene expression in zebrafish embryos. METHODS:Though normal fertilization, zebrafish embryos that incubated to the 2-cel stage (about 0.75 hour after fertilization) and shield stage (6 hours after fertilization) were colected and put into 12-wel plates treated with 100, 200, 400 nmol/L deguelin at 28.5℃in an incubator til the shield period and 24 hours after fertilization, respectively. Simultaneously embroys treated with 1% dimethyl sulfoxide solution were as a control group, cultured in the same conditions. Cyclin D1 RNA probes were prepared for the whole mountin situhybridization, observing staining by an upright fluorescent microscope camera to detect the effect of deguelin on cyclin D1 expression in zebrafish embryos. RESULTS AND CONCLUSION:Deguelin showed significant negative regulation on the expression of cyclin D1 gene in zebrafish embryos. Cyclin D1 expressed in outsourcing cels in embryos of shield stage, and a significant reduction in the expression of cyclin D1 came up with the increasing concentrations of deguelin. In the 400 nmol/L deguelin treatment group, there was nearly no expression of cyclin D1. Cyclin D1 expressed in the brain, central nervous system, immature eye, somites, trunk, and tail of embryos at 24 hours after fertilization, and reduced significantly in the 100 nmol/L deguelin treatment group, especialy in the proliferative area. In the 200 and 400 nmol/L treatment groups, the embryonic development slowed down signficantly, and cyclin D1 gene mainly expressed in the dorsal ectoderm cels.%背景:斑马鱼胚胎发育早期,细胞分裂增殖快速,低浓度的鱼藤素可以延缓斑马鱼胚胎发育。目的:观察鱼藤素对斑马鱼胚胎中细胞周期蛋白D1

  9. Efficacy of Natural and Allopathic Antimicrobial Agents Incorporated onto Guided Tissue Regeneration Membrane Against Periodontal Pathogens: An in vitro Study

    Science.gov (United States)

    Reddy Palle, Ajay; Kumar Gedela, Rajani; Vasudevan, Sanjay

    2017-01-01

    Introduction Periodontal disease is one of the most prevalent afflictions worldwide. It is an infection of the periodontium as a result of subgingival colonization of the specific microbiota, leading to loss of attachment, which requires optimal care for regeneration to its pre-disease state. Guided Tissue Regeneration (GTR) is one of the successful treatment modalities in Periodontal Regenerative Therapy, but is vulnerable to bacterial colonization. The conflict between usage of classical antibiotics and plant origin antimicrobial agents has recently been in the limelight. Aim The aim of this study was to assess the in vitro antimicrobial activity of amoxicillin, metronidazole and green coffee extract loaded onto GTR membrane against periodonto-pathogens. Materials and Methods Pure form of amoxicillin, metronidazole and green coffee extract were obtained. One percent concentration of each antimicrobial agent was prepared by appropriate dilution with distilled water. GTR membrane was cut into a size of 1x0.5 cm under sterile conditions and was coated with the antimicrobial agents respectively and with distilled water as the negative control. Antimicrobial activity was checked against Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) and Porphyromonas gingivalis (P. gingivalis) using agar disc diffusion method. The statistical analysis was done using Kruskal Wallis ANOVA and Mann-Whitney U test. Results One percent amoxicillin showed level of significance (p>0.05) against both A. actinomycetemcomitans and P. gingivalis. Green coffee extract showed no zone of inhibition against both the bacterial species. Conclusion Loading of commercially available antimicrobial agents onto GTR membrane can prevent its bacterial colonization leading to better treatment outcomes for periodontal regeneration. PMID:28274052

  10. Use of biogas generated from swine manure as preliminary agent in the feasibility construction of natural gas networks; Utilizacao do biogas gerado a partir de dejetos suinos como agente preliminar na viabilizacao da construcao de redes de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Antonio Rogerio; Ferraz, Andre; Rocha, Ivan; Azevedo, Jorge; Oshiro, Hugo K.; Konishi, Ricardo; Piazza, Walter; Lehmkuhl, Willian [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil)

    2011-12-21

    Santa Catarina state has over 800 km of natural gas distributed along the coast line, however, has an area of 95.700 km{sup 2}. Due to mountainous relief, constructing pipeline that will supply natural gas to remote areas will prove difficult. Supplying gas to remote areas through biogas from pig manure is a feasible alternative to building a gas pipeline to these regions. Using data from the IBGE and by aid of computer programs it was found that Santa Catarina has a potential to generate biogas from 900.000 m{sup 3}/day which are located predominantly in the western region of state. Thus, through the provision of biogas in this region a market that uses natural gas as an energy source can stimulate. As result the pay-back time and the feasibility risk of a network gas project can be reduced. It was found that only in the west there is an energy potential to be shifted to natural gas equivalent of 389.583 m{sup 3}/day and as expected output is estimated to reach 16.728 m{sup 3}/day. This helps anticipate the building of a natural gas network that links the coast with outskirts of the state, while the environmental impact of swine as methane emissions and waste are reduced. (author)

  11. BIODEGRADATION, MORPHOLGICAL, AND FTIR STUDY OF RATTAN POWDER-FILLED NATURAL RUBBER COMPOSITES AS A FUNCTION OF FILLER LOADING AND A SILANE COUPLING AGENT

    Directory of Open Access Journals (Sweden)

    Komethi Muniandy,

    2012-01-01

    Full Text Available Natural rubber (NR composites were prepared by the incorporation of rattan (Calamus Manan powder at filler loadings in the range of 0 to 30 phr into a natural rubber matrix with a laboratory size two roll mill. The particle size of rattan powder was less than 180 µm. The biodegradation of the rattan powder-filled natural rubber (NR composites were investigated as a function of filler loading and a silane coupling agent. A soil burial test was carried out for six months, and the degradation of the NR compound and the NR composites was evaluated through tensile testing. Morphological properties were determined using scanning electron microscopy (SEM to evaluate the degradation of the samples after six months of soil exposure. The results indicate that the tensile strength, elongation at break, and stress at 100% elongation (M 100 all decreased after soil burial testing due to the biological attack by microbes onto the sample. Improvement in tensile properties was seen with the addition of the silane coupling agent due to better adhesion between the rattan filler and the rubber matrix. The deterioration in tensile properties due to the biodegradation process was confirmed by SEM and FTIR studies.

  12. Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

    Science.gov (United States)

    Wirth, Marius; Niro, Giuliana; Leyerer, Kristin

    2016-01-01

    Summary Muraymycins are a promising class of antimicrobial natural products. These uridine-derived nucleoside-peptide antibiotics inhibit the bacterial membrane protein translocase I (MraY), a key enzyme in the intracellular part of peptidoglycan biosynthesis. This review describes the structures of naturally occurring muraymycins, their mode of action, synthetic access to muraymycins and their analogues, some structure–activity relationship (SAR) studies and first insights into muraymycin biosynthesis. It therefore provides an overview on the current state of research, as well as an outlook on possible future developments in this field. PMID:27340469

  13. Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

    Directory of Open Access Journals (Sweden)

    Daniel Wiegmann

    2016-04-01

    Full Text Available Muraymycins are a promising class of antimicrobial natural products. These uridine-derived nucleoside-peptide antibiotics inhibit the bacterial membrane protein translocase I (MraY, a key enzyme in the intracellular part of peptidoglycan biosynthesis. This review describes the structures of naturally occurring muraymycins, their mode of action, synthetic access to muraymycins and their analogues, some structure–activity relationship (SAR studies and first insights into muraymycin biosynthesis. It therefore provides an overview on the current state of research, as well as an outlook on possible future developments in this field.

  14. Nature's Chiral Catalyst and Anti-Malarial Agent: Isolation and Structure Elucidation of Cinchonine and Quinine from "Cinchona calisaya"

    Science.gov (United States)

    Carroll, Anne-Marie; Kavanagh, David J.; McGovern, Fiona P.; Reilly, Joe W.; Walsh, John J.

    2012-01-01

    Nature is a well-recognized source of compounds of interest, but access is often an issue. One pertinent example is the cinchona alkaloids from the bark of "Cinchona calisaya." In this experiment, students at the third-year undergraduate level undertake the selective isolation and characterization of two of the four main alkaloids present in the…

  15. Protecting Timber Supply on Public Land in Response to Catastrophic Natural Disturbance: A Principal-Agent Problem

    NARCIS (Netherlands)

    Bogle, T.; Kooten, van G.C.

    2015-01-01

    Catastrophic natural disturbance creates a dilemma for the public forestland owner desiring to retain growing stock and salvaging some, if not all, of the damaged timber. If logging on public forestlands is conducted by private forest companies under various tenure arrangements, attainment of the

  16. Phosphate analysis of natural sausage casings preserved in brines with phosphate additives as inactivating agent – Method validation

    NARCIS (Netherlands)

    Wijnker, J.J.; Tjeerdsma - van Bokhoven, J.L.M.; Veldhuizen, E.J.A.

    2009-01-01

    Certain phosphates have been identified as suitable additives for the improvement of the microbial and mechanical properties of processed natural sausage casings. When mixed with NaCl (sodium chloride) and used under specific treatment and storage conditions, these phosphates are found to prevent th

  17. Phosphate analysis of natural sausage casings preserved in brines with phosphate additives as inactivating agent – Method validation

    NARCIS (Netherlands)

    Wijnker, J.J.; Tjeerdsma - van Bokhoven, J.L.M.; Veldhuizen, E.J.A.

    2009-01-01

    Certain phosphates have been identified as suitable additives for the improvement of the microbial and mechanical properties of processed natural sausage casings. When mixed with NaCl (sodium chloride) and used under specific treatment and storage conditions, these phosphates are found to prevent

  18. ImmunoGrid: towards agent-based simulations of the human immune system at a natural scale

    DEFF Research Database (Denmark)

    Halling-Brown, M.; Pappalardo, F.; Rapin, Nicolas

    2010-01-01

    resources required. In this paper, we explain the key challenges and the approaches adopted to overcome them. We also consider wider implications for the present ambitious plans to develop natural-scale, integrated models of the human body that can make contributions to personalized health care...

  19. Natural products-based insecticidal agents 9. Design, semisynthesis and insecticidal activity of 28-acyloxy derivatives of toosendanin against Mythimna separata Walker in vivo.

    Science.gov (United States)

    Xu, Hui; Zhang, Jun-Liang

    2011-04-01

    In continuation of our program aimed at the discovery and development of natural products-based insecticidal agents, twelve 28-acyloxy derivatives of toosendanin (2a-l) were semisynthesized and preliminarily evaluated their activity against the pre-third-instar larvae of Mythimna separata Walker in vivo at the concentration of 1mg/mL. Some compounds exhibited the potent insecticidal activity. Especially compounds 2c and 2j displayed the more promising insecticidal activity than their natural precursor, toosendanin, a commercial insecticide derived from Melia azedarach at 1mg/mL. In general, it indicated that the butanoyloxy or phenylacryloyloxy moiety at the 28-position of toosendanin was essential for the insecticidal activity.

  20. New potential antitumoral agents of polyphenolic nature obtained from Helleborus purpurascens by membranary micro- and ultrafiltration techniques

    Directory of Open Access Journals (Sweden)

    Gabriela Vochita

    2010-06-01

    Full Text Available The in vitro action of some total aqueous and hydroalcoholic extracts and of their concentrate or permeate fractions, separated by membranary micro- and ultrafiltrations of the primary homogenates, obtained from Helleborus purpurascens ethnomedicinal plant, upon the cell protein biosynthesis, proliferation, viability and development of the HeLa cancerous cells cultures was investigated. The significant proteinsynthesis alteration, protein dynamics modification, decrease of total cell number, cell viability diminution, inhibitory impact upon the cell cultures development, during studied evolution period, suggest the behaviour of these polyphenolic hellebore extracts as in vitro active cytostatic and cytotoxic agents. Our preliminary characterization of these vegetal biopreparations as protein, mitotic, growth inhibitors offers the informational background for further investigations, on many other cancerous and normal cell lines and adequate experimental models to in vitro prescreening, as well as for their introduction in the in vivo antitumoral screening program on different experimental tumoral systems.

  1. ew potential antitumoral agents of polyphenolic nature obtained from Helleborus purpurascens by membranary micro- and ultrafiltration techniques

    Directory of Open Access Journals (Sweden)

    Gabriela Vochita

    2011-10-01

    Full Text Available The in vitro action of some total aqueous and hydroalcoholic extracts and of their concentrate or permeate fractions, separated by membranary micro- and ultrafiltrations of the primary homogenates, obtained from Helleborus purpurascens ethnomedicinal plant, upon the cell protein biosynthesis, proliferation, viability and development of the HeLa cancerous cells cultures was investigated. The significant proteinsynthesis alteration, protein dynamics modification, decrease of total cell number, cell viability diminution, inhibitory impact upon the cell cultures development, during studied evolution period, suggest the behaviour of these polyphenolic hellebore extracts as in vitro active cytostatic and cytotoxic agents. Our preliminary characterization of these vegetal biopreparations as protein, mitotic, growth inhibitors offers the informational background for further investigations, on many other cancerous and normal cell lines and adequate experimental models to in vitro prescreening, as well as for their introduction in the in vivo antitumoral screening program on different experimental tumoral systems.

  2. Preliminary in vitro insights into the use of natural fungal pathogens of leaf-cutting ants as biocontrol agents.

    Science.gov (United States)

    Folgarait, Patricia; Gorosito, Norma; Poulsen, Michael; Currie, Cameron R

    2011-09-01

    Leaf-cutting ants are one of the main herbivores of the Neotropics, where they represent an important agricultural pest. These ants are particularly difficult to control because of the complex network of microbial symbionts. Leaf-cutting ants have traditionally been controlled through pesticide application, but there is a need for alternative, more environmentally friendly, control methods such as biological control. Potential promising biocontrol candidates include the microfungi Escovopsis spp. (anamorphic Hypocreales), which are specialized pathogens of the fungi the ants cultivate for food. These pathogens are suppressed through ant behaviors and ant-associated antibiotic-producing Actinobacteria. In order to be an effective biocontrol agent, Escovopsis has to overcome these defenses. Here, we evaluate, using microbial in vitro assays, whether defenses in the ant-cultivated fungus strain (Leucoagaricus sp.) and Actinobacteria from the ant pest Acromyrmex lundii have the potential to limit the use of Escovopsis in biocontrol. We also explore, for the first time, possible synergistic biocontrol between Escovopsis and the entomopathogenic fungus Lecanicillium lecanii. All strains of Escovopsis proved to overgrow A. lundii cultivar in less than 7 days, with the Escovopsis strain isolated from a different leaf-cutting ant species being the most efficient. Escovopsis challenged with a Streptomyces strain isolated from A. lundii did not exhibit significant growth inhibition. Both results are encouraging for the use of Escovopsis as a biocontrol agent. Although we found that L. lecanii can suppress the growth of the cultivar, it also had a negative impact on Escovopsis, making the success of simultaneous use of these two fungi for biocontrol of A. lundii questionable.

  3. Natural product derived antiprotozoal agents: synthesis, biological evaluation, and structure-activity relationships of novel chromene and chromane derivatives.

    Science.gov (United States)

    Harel, Dipak; Schepmann, Dirk; Prinz, Helge; Brun, Reto; Schmidt, Thomas J; Wünsch, Bernhard

    2013-09-26

    Various natural products with the chromane and chromene scaffold exhibit high antiprotozoal activity. The natural product encecalin (7) served as key intermediate for the synthesis of different ethers 9, amides 11, and amines 12. The chromane analogues 14 and the phenols 15 were obtained by reductive amination of ketones 13 and 6, respectively. Angelate 3, ethers 9, and amides 11 did not show considerable antiprotozoal activity. However, the chromene and chromane derived amines 12, 14, and 15 revealed promising antiprotozoal activity and represent novel lead compounds. Whereas benzylamine 12a and α-methylbenzylamine 12g were active against P. falciparum with IC50 values in the range of chloroquine, the analogous phenols 15a and 15b were unexpectedly 10- to 25-fold more potent than chloroquine with selectivity indexes of 6760 and 1818, respectively. The phenylbutylamine 14d based on the chromane scaffold has promising activity against T. brucei rhodesiense and L. donovani.

  4. A New Approach to Predict the Fish Fillet Shelf-Life in Presence of Natural Preservative Agents.

    Science.gov (United States)

    Giuffrida, Alessandro; Giarratana, Filippo; Valenti, Davide; Muscolino, Daniele; Parisi, Roberta; Parco, Alessio; Marotta, Stefania; Ziino, Graziella; Panebianco, Antonio

    2017-04-13

    Three data sets concerning the behaviour of spoilage flora of fillets treated with natural preservative substances (NPS) were used to construct a new kind of mathematical predictive model. This model, unlike other ones, allows expressing the antibacterial effect of the NPS separately from the prediction of the growth rate. This approach, based on the introduction of a parameter into the predictive primary model, produced a good fitting of observed data and allowed characterising quantitatively the increase of shelf-life of fillets.

  5. natural

    Directory of Open Access Journals (Sweden)

    Elías Gómez Macías

    2006-01-01

    Full Text Available Partiendo de óxido de magnesio comercial se preparó una suspensión acuosa, la cual se secó y calcinó para conferirle estabilidad térmica. El material, tanto fresco como usado, se caracterizó mediante DRX, área superficial BET y SEM-EPMA. El catalizador mostró una matriz de MgO tipo periclasa con CaO en la superficie. Las pruebas de actividad catalítica se efectuaron en lecho fijo empacado con partículas obtenidas mediante prensado, trituración y clasificación del material. El flujo de reactivos consistió en mezclas gas natural-aire por debajo del límite inferior de inflamabilidad. Para diferentes flujos y temperaturas de entrada de la mezcla reactiva, se midieron las concentraciones de CH4, CO2 y CO en los gases de combustión con un analizador de gases tipo infrarrojo no dispersivo (NDIR. Para alcanzar conversión total de metano se requirió aumentar la temperatura de entrada al lecho a medida que se incrementó el flujo de gases reaccionantes. Los resultados obtenidos permiten desarrollar un sistema de combustión catalítica de bajo costo con un material térmicamente estable, que promueva la alta eficiencia en la combustión de gas natural y elimine los problemas de estabilidad, seguridad y de impacto ambiental negativo inherentes a los procesos de combustión térmica convencional.

  6. The contagious nature of imprisonment: an agent-based model to explain racial disparities in incarceration rates.

    Science.gov (United States)

    Lum, Kristian; Swarup, Samarth; Eubank, Stephen; Hawdon, James

    2014-09-01

    We build an agent-based model of incarceration based on the susceptible-infected-suspectible (SIS) model of infectious disease propagation. Our central hypothesis is that the observed racial disparities in incarceration rates between Black and White Americans can be explained as the result of differential sentencing between the two demographic groups. We demonstrate that if incarceration can be spread through a social influence network, then even relatively small differences in sentencing can result in large disparities in incarceration rates. Controlling for effects of transmissibility, susceptibility and influence network structure, our model reproduces the observed large disparities in incarceration rates given the differences in sentence lengths for White and Black drug offenders in the USA without extensive parameter tuning. We further establish the suitability of the SIS model as applied to incarceration by demonstrating that the observed structural patterns of recidivism are an emergent property of the model. In fact, our model shows a remarkably close correspondence with California incarceration data. This work advances efforts to combine the theories and methods of epidemiology and criminology.

  7. Detection and molecular characterization of canine babesiosis causative agent Babesia canis in the naturally infected dog in Lithuania.

    Science.gov (United States)

    Paulauskas, Algimantas; Radzijevskaja, Jana; Karvelienė, Birutė; Grigonis, Aidas; Aleksandravičienė, Asta; Zamokas, Gintaras; Babickaitė, Lina; Sabūnas, Vytautas; Petkevičius, Saulius

    2014-10-15

    Canine babesiosis caused by Babesia canis is an emerging infectious disease in Europe. Although previously uncommon, canine babesiosis has become quite frequent in Lithuania during the past decade. In the last few years an increasing number of cases with a wide variety of clinical signs have been recorded throughout the country. In Lithuania the identification of the disease agent in veterinarian clinics is based on a microscopic analysis of size and morphology. To date, no data on the genetic characterization of Babesia species in dogs have been documented for Lithuania. A total of 123 blood samples from dogs showing clinical signs of babesiosis on the basis of veterinary examination were tested for the presence of babesial parasites. Babesia isolated from dogs were detected and characterized by nested-PCR and sequence analysis of a fragment of the 18S rRNA gene. Babesia parasites were detected in blood smears of 94 dogs (76.4%). The molecular analysis revealed the presence of B. canis in 108 dogs (87.8%). Two genotypes of B. canis were distinguished on the basis on two nucleotide (GA → AG) substitutions observed in 18S rRNA gene sequences. The results of the present study provide knowledge of the distribution of B. canis genotypes in dogs in Lithuania, and show the necessity to use a molecular analysis for an accurate diagnosis of canine babesiosis.

  8. Protein Abundances can Distinguish Between Naturally-occurring and Laboratory Strains of Yersinia pestis, the Causative Agent of Plague

    Energy Technology Data Exchange (ETDEWEB)

    Merkley, Eric D.; Sego, Landon H.; Lin, Andy; Leiser, Owen P.; Kaiser, Brooke LD; Adkins, Joshua N.; Keim, Paul S.; Wagner, David M.; Kreuzer, Helen W.

    2017-08-30

    Adaptive processes in bacterial species can occur rapidly in laboratory culture, leading to genetic divergence between naturally occurring and laboratory-adapted strains. Differentiating wild and closely-related laboratory strains is clearly important for biodefense and bioforensics; however, DNA sequence data alone has thus far not provided a clear signature, perhaps due to lack of understanding of how diverse genome changes lead to adapted phenotypes. Protein abundance profiles from mass spectrometry-based proteomics analyses are a molecular measure of phenotype. Proteomics data contains sufficient information that powerful statistical methods can uncover signatures that distinguish wild strains of Yersinia pestis from laboratory-adapted strains.

  9. A new approach to predict the fish fillet shelf-life in presence of natural preservative agents

    Directory of Open Access Journals (Sweden)

    Alessandro Giufffrida

    2017-06-01

    Full Text Available Three data sets concerning the behaviour of spoilage flora of fillets treated with natural preservative substances (NPS were used to construct a new kind of mathematical predictive model. This model, unlike other ones, allows expressing the antibacterial effect of the NPS separately from the prediction of the growth rate. This approach, based on the introduction of a parameter into the predictive primary model, produced a good fitting of observed data and allowed characterising quantitatively the increase of shelf-life of fillets.

  10. A natural product inspired hybrid approach towards the synthesis of novel pentamidine based scaffolds as potential anti-parasitic agents.

    Science.gov (United States)

    Tyagi, Vikas; Khan, Shahnawaz; Shivahare, Rahul; Srivastava, Khushboo; Gupta, Suman; Kidwai, Saqib; Srivastava, Kumkum; Puri, S K; Chauhan, Prem M S

    2013-01-01

    A natural product inspired molecular hybridization approach led us to a series of novel pentamidine based pyrimidine and chalcone scaffolds. All the hybrids were evaluated for their anti-leishmanial potential. Most of the screened compounds have showed significant in vitro anti-leishmanial activity with less cytotoxicity in comparison to the standard drugs (pentamidine, sodium stibogluconate, and miltefosine). Additionally, anti-malarial screening of these compounds was also done and four compounds have shown superior activity against chloroquine resistance strain (K1) of Plasmodium falciparum.

  11. Natural Products as Chemopreventive Agents by Potential Inhibition of the Kinase Domain in ErbB Receptors.

    Science.gov (United States)

    Olivero-Acosta, Maria; Maldonado-Rojas, Wilson; Olivero-Verbel, Jesus

    2017-02-17

    Small molecules found in natural products provide therapeutic benefits due to their pharmacological or biological activity, which may increase or decrease the expression of human epidermal growth factor receptor (HER), a promising target in the modification of signaling cascades involved in excessive cellular growth. In this study, in silico molecular protein-ligand docking protocols were performed with AutoDock Vina in order to evaluate the interaction of 800 natural compounds (NPs) from the NatProd Collection (http://www.msdiscovery.com/natprod.html), with four human HER family members: HER1 (PDB: 2ITW), HER2 (PDB: 3PP0), HER3 (PDB: 3LMG) and HER4 (PDB: 2R4B). The best binding affinity values (kcal/mol) for docking pairs were obtained for HER1-podototarin (-10.7), HER2-hecogenin acetate (-11.2), HER3-hesperidin (-11.5) and HER4-theaflavin (-10.7). The reliability of the theoretical calculations was evaluated employing published data on HER inhibition correlated with in silico binding calculations. IC50 values followed a significant linear relationship with the theoretical binding Affinity data for HER1 (R = 0.656, p 0.05). In short, this methodology allowed the identification of several NPs as HER inhibitors, being useful in the discovery and design of more potent and selective anticancer drugs.

  12. Physical and Antimicrobial Properties of Starch-PVA Blend Films as Affected by the Incorporation of Natural Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Amalia Cano

    2015-12-01

    Full Text Available In this work, active films based on starch and PVA (S:PVA ratio of 2:1 were developed by incorporating neem (NO and oregano essential oils (OEO. First, a screening of the antifungal effectiveness of different natural extracts (echinacea, horsetail extract, liquid smoke and neem seed oil against two fungus (P. expansum and A. niger was carried out. The effect of NO and OEO incorporation on the films’ physical and antimicrobial properties was analyzed. Only composite films containing OEO exhibited antibacterial and antifungal activity. Antibacterial activity occurred at low OEO concentration (6.7%, while antifungal effect required higher doses of OEO in the films. Incorporation of oils did not notably affect the water sorption capacity and water vapor barrier properties of S-PVA films, but reduced their transparency and gloss, especially at the highest concentrations. The mechanical response of the S-PVA films was also negatively affected by oil incorporation but this was only relevant at the highest oil ratio (22%. S-PVA films with 6.7% of OEO exhibited the best physical properties, without significant differences with respect to the S-PVA matrix, while exhibiting antibacterial activity. Thus, the use of OEO as a natural antimicrobial incorporated into starch-PVA films represents a good and novel alternative in food packaging applications.

  13. Physical and Antimicrobial Properties of Starch-PVA Blend Films as Affected by the Incorporation of Natural Antimicrobial Agents

    Science.gov (United States)

    Cano, Amalia; Cháfer, Maite; Chiralt, Amparo; González-Martínez, Chelo

    2015-01-01

    In this work, active films based on starch and PVA (S:PVA ratio of 2:1) were developed by incorporating neem (NO) and oregano essential oils (OEO). First, a screening of the antifungal effectiveness of different natural extracts (echinacea, horsetail extract, liquid smoke and neem seed oil) against two fungus (P. expansum and A. niger) was carried out. The effect of NO and OEO incorporation on the films’ physical and antimicrobial properties was analyzed. Only composite films containing OEO exhibited antibacterial and antifungal activity. Antibacterial activity occurred at low OEO concentration (6.7%), while antifungal effect required higher doses of OEO in the films. Incorporation of oils did not notably affect the water sorption capacity and water vapor barrier properties of S-PVA films, but reduced their transparency and gloss, especially at the highest concentrations. The mechanical response of the S-PVA films was also negatively affected by oil incorporation but this was only relevant at the highest oil ratio (22%). S-PVA films with 6.7% of OEO exhibited the best physical properties, without significant differences with respect to the S-PVA matrix, while exhibiting antibacterial activity. Thus, the use of OEO as a natural antimicrobial incorporated into starch-PVA films represents a good and novel alternative in food packaging applications.

  14. Investigation of some locally water-soluble natural polymers as circulation loss control agents during oil fields drilling

    Directory of Open Access Journals (Sweden)

    A.M. Alsabagh

    2014-03-01

    Full Text Available Eliminating or controlling lost circulation during drilling process is costly and time-consuming. Polymers play an important role in mud loss control for their viscosity due to their high molecular weight. In this paper, three natural cellulosic polymers (carboxymethyl cellulose, guar gum and potato starch were investigated as lost circulation control material by measuring different filtration parameters such as; spurt loss, fluid loss and permeability plugging tester value according to the American Petroleum Institute (API standard. The experiments were conducted in a permeability plugging apparatus (PPA at a differential pressure of 100 and 300 psi, using 10, 60 and 90 ceramic discs. From the obtained data, it was found that the 0.1% from the carboxymethyl cellulose exhibited the best results in the filtration parameters among 0.3% guar gum and 0.6% potato starch. At the same time the carboxymethyl cellulose (CMC enhanced the rheological properties of the drilling mud better than the two other used natural polymers in the term of gel strength, thixotropy, plastic and apparent viscosity. These results were discussed in the light of the adsorption and micellar formation.

  15. Melatonin, a potent agent in antioxidative defense: Actions as a natural food constituent, gastrointestinal factor, drug and prodrug

    Directory of Open Access Journals (Sweden)

    Pandi-Perumal SR

    2005-09-01

    Full Text Available Abstract Melatonin, originally discovered as a hormone of the pineal gland, is also produced in other organs and represents, additionally, a normal food constituent found in yeast and plant material, which can influence the level in the circulation. Compared to the pineal, the gastrointestinal tract contains several hundred times more melatonin, which can be released into the blood in response to food intake and stimuli by nutrients, especially tryptophan. Apart from its use as a commercial food additive, supraphysiological doses have been applied in medical trials and pure preparations are well tolerated by patients. Owing to its amphiphilicity, melatonin can enter any body fluid, cell or cell compartment. Its properties as an antioxidant agent are based on several, highly diverse effects. Apart from direct radical scavenging, it plays a role in upregulation of antioxidant and downregulation of prooxidant enzymes, and damage by free radicals can be reduced by its antiexcitatory actions, and presumably by contributions to appropriate internal circadian phasing, and by its improvement of mitochondrial metabolism, in terms of avoiding electron leakage and enhancing complex I and complex IV activities. Melatonin was shown to potentiate effects of other antioxidants, such as ascorbate and Trolox. Under physiological conditions, direct radical scavenging may only contribute to a minor extent to overall radical detoxification, although melatonin can eliminate several of them in scavenger cascades and potentiates the efficacy of antioxidant vitamins. Melatonin oxidation seems rather important for the production of other biologically active metabolites such as N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK and N1-acetyl-5-methoxykynuramine (AMK, which have been shown to also dispose of protective properties. Thus, melatonin may be regarded as a prodrug, too. AMK interacts with reactive oxygen and nitrogen species, conveys protection to mitochondria

  16. Synthesis of ent-BE-43547A1 reveals a potent hypoxia-selective anticancer agent and uncovers the biosynthetic origin of the APD-CLD natural products

    Science.gov (United States)

    Villadsen, Nikolaj L.; Jacobsen, Kristian M.; Keiding, Ulrik B.; Weibel, Esben T.; Christiansen, Bjørn; Vosegaard, Thomas; Bjerring, Morten; Jensen, Frank; Johannsen, Mogens; Tørring, Thomas; Poulsen, Thomas B.

    2017-03-01

    Tumour hypoxia is speculated to be a key driver of therapeutic resistance and metastatic dissemination. Consequently, the discovery of new potent agents that selectively target the hypoxic cell population may reveal new and untapped antitumour mechanisms. Here we demonstrate that the BE-43547 subclass of the APD-CLD (amidopentadienoate-containing cyclolipodepsipeptides) natural products possesses highly hypoxia-selective growth-inhibitory activity against pancreatic cancer cells. To enable this discovery, we have developed the first synthesis of the BE-43547-macrocyclic scaffold in 16 steps (longest linear sequence), which also allowed access to the full panel of relative stereoisomers and ultimately to the assignment of stereochemical configuration. Discrepancies between the spectroscopic signatures of the synthetic compounds with that originally reported for the BE-43547 members stimulated us to re-isolate the natural product from a BE-43547-producing microorganism during which we elucidated the biosynthetic gene clusters for the BE-43547 family as well as for all other known APD-CLDs. Our studies underline the exciting possibilities for the further development of the anticancer activities of these natural products.

  17. Structure of daidzin, a naturally occurring anti-alcohol-addiction agent, in complex with human mitochondrial aldehyde dehydrogenase.

    Science.gov (United States)

    Lowe, Edward D; Gao, Guang-Yao; Johnson, Louise N; Keung, Wing Ming

    2008-08-14

    The ALDH2*2 gene encoding the inactive variant form of mitochondrial aldehyde dehydrogenase (ALDH2) protects nearly all carriers of this gene from alcoholism. Inhibition of ALDH2 has hence become a possible strategy to treat alcoholism. The natural product 7-O-glucosyl-4'-hydroxyisoflavone (daidzin), isolated from the kudzu vine ( Peruraria lobata), is a specific inhibitor of ALDH2 and suppresses ethanol consumption. Daidzin is the active principle in a herbal remedy for "alcohol addiction" and provides a lead for the design of improved ALDH2. The structure of daidzin/ALDH2 in complex at 2.4 A resolution shows the isoflavone moiety of daidzin binding close to the aldehyde substrate-binding site in a hydrophobic cleft and the glucosyl function binding to a hydrophobic patch immediately outside the isoflavone-binding pocket. These observations provide an explanation for both the specificity and affinity of daidzin (IC50 =80 nM) and the affinity of analogues with different substituents at the glucosyl position.

  18. Exploring the use of natural antimicrobial agents and pulsed electric fields to control spoilage bacteria during a beer production process.

    Science.gov (United States)

    Galvagno, M A; Gil, G R; Iannone, L J; Cerrutti, P

    2007-01-01

    Different natural antimicrobials affected viability of bacterial contaminants isolated at critical steps during a beer production process. In the presence of 1 mg/ml chitosan and 0.3 mg/ml hops, the viability of Escherichia coli in an all malt barley extract wort could be reduced to 0.7 and 0.1% respectively after 2 hour- incubation at 4 degrees C. The addition of 0.0002 mg/ml nisin, 0.1 mg/ml chitosan or 0.3 mg/ml hops, selectively inhibited growth of Pediococcus sp. in more than 10,000 times with respect to brewing yeast in a mixed culture. In the presence of 0.1 mg ml chitosan in beer, no viable cells of the thermoresistant strain Bacillus megaterium were detected. Nisin, chitosan and hops increased microbiological stability during storage of a local commercial beer inoculated with Lactobacillus plantarum or Pediococcus sp. isolated from wort. Pulsed Electric Field (PEF) (8 kV/cm, 3 pulses) application enhanced antibacterial activity of nisin and hops but not that of chitosan. The results herein obtained suggest that the use of these antimicrobial compounds in isolation or in combination with PEF would be effective to control bacterial contamination during beer production and storage.

  19. Influence of Filler from a Renewable Resource and Silane Coupling Agent on the Properties of Epoxidized Natural Rubber Vulcanizates

    Directory of Open Access Journals (Sweden)

    Wiphawadee Pongdong

    2015-01-01

    Full Text Available Rice husk ash (RHA was used as a reinforcing filler in epoxidized natural rubber (ENR with various loading levels (0, 10, 20, and 30 phr, and silica filled ENR was also studied for comparison. The effects of RHA content on cure characteristics, mechanical properties, dynamic mechanical properties, and thermoelastic behavior of the filled ENR composites were investigated. It was found that the incorporation of RHA significantly affected the cure characteristics and mechanical properties. That is, the incorporation of RHA caused faster curing reactions and increased Young’s modulus and tensile strength relative to the unfilled compound. This might be attributed to the metal oxide impurities in RHA that enhance the crosslinking reactions, thus increasing the crosslink density. Further improvements in the curing behavior and the mechanical properties of the filled composites were achieved by in situ silanization with bis(triethoxysilylpropyl tetrasulfide (Si69. It was found that the rubber-filler interactions reinforced the composites. This was indicated by the decreased damping characteristic (tan ⁡δ and the other changes in the mechanical properties. Furthermore, the ENR composites with Si69 had improved filler dispersion. Temperature scanning stress relaxation (TSSR results suggest that the metal oxide impurities in RHA promote degradation of the polymer network at elevated temperatures.

  20. FATIGUE LIFE, MORPHOLOGICAL STUDIES, AND THERMAL AGING OF RATTAN POWDER-FILLED NATURAL RUBBER COMPOSITES AS A FUNCTION OF FILLER LOADING AND A SILANE COUPLING AGENT

    Directory of Open Access Journals (Sweden)

    Hanafi Ismail,

    2012-01-01

    Full Text Available Fatigue life, morphological studies, and thermal aging properties of rattan powder-filled natural rubber (NR composites were investigated as a function of filler loading and a silane coupling agent. NR composites were prepared by the incorporation of rattan powder in the range of 0 to 30 phr into a NR matrix with a laboratory size two roll mill. Thermal aging was carried out for 7 and 14 days at a temperature of 70 °C, and tensile testing was performed in order to determine the aging properties. The results indicated that the fatigue life of rattan powder-filled NR composites decreased with increasing rattan powder loading. Tensile strength and elongation at break decreased whilst tensile modulus, stress at 100% elongation (M100, and stress at 300% elongation (M300 increased after aging. Nevertheless, the addition of the silane coupling agent improved both fatigue life and the aging properties of NR composites due to better adhesion between the rubber matrix and the rattan filler which was confirmed by FTIR studies of composites and SEM studies of fatigue fractured surfaces.

  1. Effect of the salting-out agent anion nature on the phase separation of a potassium salt-potassium bis(alkyl polyoxyethylene)phosphate-water systems

    Science.gov (United States)

    Elokhov, A. M.; Lesnov, A. E.; Kudryashova, O. S.

    2016-10-01

    The effect the salting-out agent anion nature has on the temperature and concentration intervals of the existence of the separation area is established by analyzing the phase diagrams of pseudoternary KCl (KBr, KI, KNO3, K2SO4, K4P2O7)-potassium bis(alkyl polyoxyethylene)phosphate (oxyphos B)-water systems. It is concluded that the anionic salting-out capability is reduced in the order P2O 7 4- > SO 4 2- > Cl- > Br‒> NO 7 4- > SO 3 - > I-. The thermodynamic parameters of phase separation used to interpret the results are calculated. The observed pattern of a change in the salting-out ability of the investigated salts relative to aqueous solutions of the surfactants is in good agreement with the lyotropic (Hofmeister) series.

  2. Design and synthesis of 3,4-methylenedioxy-6-nitrophenoxyacetylhydrazone derivatives obtained from natural safrole: new lead-agents with analgesic and antipyretic properties.

    Science.gov (United States)

    Bezerra-Netto, Heleno J C; Lacerda, Daniel I; Miranda, Ana Luisa P; Alves, Hélio M; Barreiro, Eliezer J; Fraga, Carlos A M

    2006-12-01

    In this work, we reported the synthesis and evaluation of the analgesic, anti-inflammatory, and antipyretic properties of new 2-(6-nitro-benzo[1,3]dioxol-5-yloxy)-acetylhydrazone derivatives (3), designed exploring molecular hybridization and isosteric replacement approaches between nimesulide (1) and carbanalogue NAH series (2) developed at LASSBio. Target compounds were synthesized in very good yields exploiting abundant Brazilian natural product safrole (4) as starting material. The evaluation of the antinociceptive properties of this series led us to discover a new potent prototype of analgesic and antipyretic agent, that is, NAH derivative 3c, named LASSBio-891, which showed to be more potent than dipyrone used as standard.

  3. A Substrate Fed-Batch Biphasic Catalysis Process for the Production of Natural Crosslinking Agent Genipin with Fusarium solani ACCC 36223.

    Science.gov (United States)

    Zhu, Yuyao; Zhao, Botao; Huang, Xiaode; Chen, Bin; Qian, Hua

    2015-06-01

    The natural crosslinking agent genipin has been applied widely in biomedicines and foods nowadays. Because of the special hemiacetal ring structure in its molecule, it can only be prepared by hydrolysis of geniposide according to biocatalysis. In this research, strategies including aqueous-organic biphasic catalysis and substrate fed-batch mode were adopted to improve the biocatalysis process of genipin. A 10 L ethyl acetate-aqueous biphasic system with geniposide fed-batch led to a satisfying genipin yield. With Fusarium solani ACCC 36223, 15.7 g/l genipin in the ethyl acetate phase was obtained, corresponding to space-time yields of 0.654 g l(-1) h(-1).

  4. Natural products-based insecticidal agents 7. Semisynthesis and insecticidal activity of novel 4alpha-alkyloxy-2-chloropodophyllotoxin derivatives against Mythimna separata Walker in vivo.

    Science.gov (United States)

    Xu, Hui; Xiao, Xiao; Wang, Qing-tian

    2010-09-01

    In continuation of our program aimed at the discovery and development of natural products-based insecticidal agents, 16 novel 4alpha-alkyloxy-2-chloropodophyllotoxin derivatives were semisynthesized from podophyllotoxin, and preliminarily evaluated for their insecticidal activity against the pre-third-instar larvae of Mythimna separata Walker in vivo. Among all the tested derivatives, especially compounds 4b, 4e, 4g, and 4p exhibited more promising and pronounced insecticidal activity than toosendanin, a commercial insecticide derived from Melia azedarach. Generally, it was obviously demonstrated that the length of straight-chain or branched-chain alkyloxy, and heteroatom-containing cycloalkyloxy at the C-4 position of 2-chloropodophyllotoxin were very important for the insecticidal activity.

  5. Natural products-based insecticidal agents 11. Synthesis and insecticidal activity of novel 4α-arylsulfonyloxybenzyloxy-2β-chloropodophyllotoxin derivatives against Mythimna separata Walker in vivo.

    Science.gov (United States)

    Xu, Hui; Zhang, Jun-Liang

    2011-09-15

    In continuation of our program aimed at the discovery and development of natural products-based insecticidal agents, 14 novel 4α-arylsulfonyloxybenzyloxy-2β-chloropodophyllotoxin derivatives were stereoselectively semisynthesized from podophyllotoxin, and preliminarily evaluated for their insecticidal activity against the pre-third-instar larvae of Mythimna separata Walker in vivo. Especially compounds 9c' and 9g' exhibited the most promising and pronounced insecticidal activity than toosendanin, a commercial insecticide derived from Melia azedarach at 1mg/mL. Generally, it was preliminarily demonstrated that arylsulfonyloxy groups at the C-2 position of benzyloxy moiety and the length of the side chain on the benzenesulfonyloxy group of 4α-arylsulfonyloxybenzyloxy-2β-chloropodophyllotoxins might be important for the insecticidal activity.

  6. Natural-product-based insecticidal agents 14. Semisynthesis and insecticidal activity of new piperine-based hydrazone derivatives against Mythimna separata Walker in vivo.

    Science.gov (United States)

    Qu, Huan; Yu, Xiang; Zhi, Xiaoyan; Lv, Min; Xu, Hui

    2013-10-15

    In continuation of our program aimed at the discovery and development of natural-product-based insecticidal agents, twenty-six new piperine-based hydrazone derivatives were synthesized from piperine, an alkaloid isolated from Piper nigrum Linn. The single-crystal structures of 6c, 6q and 6w were unambiguously confirmed by X-ray crystallography. Their insecticidal activity was evaluated against the pre-third-instar larvae of Mythimna separata Walker in vivo. Especially compounds 6b, 6i and 6r, the final mortality rates of which, at the concentration of 1 mg/mL, were 62.1%, 65.5% and 65.5%, respectively, exhibited more pronounced insecticidal activity compared to toosendanin at 1 mg/mL, a commercial botanical insecticide isolated from Melia azedarach. It suggested that introduction of the substituents at the C-2 position on the phenyl ring of the hydrazone derivatives was important for their insecticidal activity.

  7. A Collective Case Study of Secondary Students' Model-Based Inquiry on Natural Selection through Programming in an Agent-Based Modeling Environment

    Science.gov (United States)

    Xiang, Lin

    This is a collective case study seeking to develop detailed descriptions of how programming an agent-based simulation influences a group of 8 th grade students' model-based inquiry (MBI) by examining students' agent-based programmable modeling (ABPM) processes and the learning outcomes. The context of the present study was a biology unit on natural selection implemented in a charter school of a major California city during spring semester of 2009. Eight 8th grade students, two boys and six girls, participated in this study. All of them were low socioeconomic status (SES). English was a second language for all of them, but they had been identified as fluent English speakers at least a year before the study. None of them had learned either natural selection or programming before the study. The study spanned over 7 weeks and was comprised of two study phases. In phase one the subject students learned natural selection in science classroom and how to do programming in NetLogo, an ABPM tool, in a computer lab; in phase two, the subject students were asked to program a simulation of adaptation based on the natural selection model in NetLogo. Both qualitative and quantitative data were collected in this study. The data resources included (1) pre and post test questionnaire, (2) student in-class worksheet, (3) programming planning sheet, (4) code-conception matching sheet, (5) student NetLogo projects, (6) videotaped programming processes, (7) final interview, and (8) investigator's field notes. Both qualitative and quantitative approaches were applied to analyze the gathered data. The findings suggested that students made progress on understanding adaptation phenomena and natural selection at the end of ABPM-supported MBI learning but the progress was limited. These students still held some misconceptions in their conceptual models, such as the idea that animals need to "learn" to adapt into the environment. Besides, their models of natural selection appeared to be

  8. The new scenario of expansion in the sector of petroleum and natural gas in Brazil and the important role of public agents connected to the energy sector; O novo cenario de expansao do setor de petroleo e gas natural no Brasil e relevante papel dos agentes publicos ligados ao setor energetico

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ednaldo Patricio da; Dantas, Daniel Ramos; Silveira Neto, Otacilio dos Santos [Universidade Federal do Rio Grande do Norte (PRH-36/UFRN), Natal, RN (Brazil). Programa de Recursos Humanos em Direito do Petroleo; Albuquerque Junior, Helio Varela de [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    The modern scenery of oil and natural gas industry is growing up, winning prominence the necessity of a good energetic planning, that objective the new way of use renew energies with the incontestable importance that oil and natural gas represent to our current energetic matrix. In this context, the public agents of this sector, to know, the National Agency of Petroleum, Natural Gas and Biofuels (Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis), sector's regulator and supervisory, and the federal government, Ministry of Mines and Energy ( Ministerio de Minas e Energia) and the National Council for Energy Policy (Conselho Nacional de Politicas Energeticas), essential functions in the national energetic sector's structure, specially about these both energetic resorts. This new vision, that the industry is insert, well-known for the discover of new camps off shore, for the change of Brazilian position from importer to exporter of these products and for the big numbers that the sector represents to the national economy, demand a new behavior from the organs above mentioned, starting from organization ideas and fitness of its activities to the new paradigm that the country are going to face next years. In this context, deserves prominence the role that the Growth Acceleration Program (Programa de Aceleracao do Crescimento) represents in the search for a well structure and efficient energetic planning, plus the prominence position that Brazil is taking on its South America economic-energetic integration and the necessity of a regulatory stability about still dark points in our legislation, such happens, for example, with the natural gas. In front of all these elements, this article will have as a main purpose the addressing different aspects that contributed to the natural gas and oil industry's spread out in Brazil, also, the consequences that this advance will provide to the public agents work responsible to the sector. (author)

  9. Detection of Natural Resistance-Associated Substitutions by Ion Semiconductor Technology in HCV1b Positive, Direct-Acting Antiviral Agents-Naïve Patients

    Science.gov (United States)

    Marascio, Nadia; Pavia, Grazia; Strazzulla, Alessio; Dierckx, Tim; Cuypers, Lize; Vrancken, Bram; Barreca, Giorgio Settimo; Mirante, Teresa; Malanga, Donatella; Oliveira, Duarte Mendes; Vandamme, Anne-Mieke; Torti, Carlo; Liberto, Maria Carla; Focà, Alfredo

    2016-01-01

    Naturally occurring resistance-associated substitutions (RASs) can negatively impact the response to direct-acting antivirals (DAAs) agents-based therapies for hepatitis C virus (HCV) infection. Herein, we set out to characterize the RASs in the HCV1b genome from serum samples of DAA-naïve patients in the context of the SINERGIE (South Italian Network for Rational Guidelines and International Epidemiology, 2014) project. We deep-sequenced the NS3/4A protease region of the viral population using the Ion Torrent Personal Genome Machine, and patient-specific majority rule consensus sequence summaries were constructed with a combination of freely available next generation sequencing data analysis software. We detected NS3/4A protease major and minor variants associated with resistance to boceprevir (V36L), telaprevir (V36L, I132V), simeprevir (V36L), and grazoprevir (V36L, V170I). Furthermore, we sequenced part of HCV NS5B polymerase using Sanger-sequencing and detected a natural RAS for dasabuvir (C316N). This mutation could be important for treatment strategies in cases of previous therapy failure. PMID:27618896

  10. Application of Antimicrobial Agents Produced by Lactobacillus plantarum IIA-1A5 as Natural Preservative on Beef during Room Temperature Storage

    Directory of Open Access Journals (Sweden)

    Dewi Elfrida Sihombing

    2015-05-01

    Full Text Available Lactobacillus plantarum IIA-1A5 is indigenous lactic acid bacteria isolated from Indonesian beef. Lactobacillus plantarum IIA-1A5 was reported could produce bacteriocin, called plantaricin IIA-1A5. The aims of this research was to analyze application of plantaricin IIA-1A5 as a natural preservative on beef. Based on antagonistic test, plantaricin IIA-1A5 had good moderate antimicrobial activity against pathogenic bacteria isolated from human’s feces that cause diarrhea such as Salmonella 38, Enteropathogenic Escherichia coli K11 and Shigella A33. Application of plantaricin IIA-1A5 was effective as a natural preservative on beef stored at room temperature by inhibiting the growth of Escherichia coli and Staphylococcus aureus. Plantaricin IIA-1A5 could kill all of the Escherichia coli after 5 h storage. Plantaricin IIA-1A5 could reduce the population of Staphylococcus aureus in beef during room temperature storage. Interestingly, plantaricin produced by Lactobacillus plantarum IIA-1A5 was effective against gram negative and positive bacteria. According to physichochemichal and microbiology quality, plantaricin IIA-1A5 was recommended as biopreservative agents for beef.

  11. Detection of Natural Resistance-Associated Substitutions by Ion Semiconductor Technology in HCV1b Positive, Direct-Acting Antiviral Agents-Naïve Patients.

    Science.gov (United States)

    Marascio, Nadia; Pavia, Grazia; Strazzulla, Alessio; Dierckx, Tim; Cuypers, Lize; Vrancken, Bram; Barreca, Giorgio Settimo; Mirante, Teresa; Malanga, Donatella; Oliveira, Duarte Mendes; Vandamme, Anne-Mieke; Torti, Carlo; Liberto, Maria Carla; Focà, Alfredo; The Sinergie-Umg Study Group

    2016-08-27

    Naturally occurring resistance-associated substitutions (RASs) can negatively impact the response to direct-acting antivirals (DAAs) agents-based therapies for hepatitis C virus (HCV) infection. Herein, we set out to characterize the RASs in the HCV1b genome from serum samples of DAA-naïve patients in the context of the SINERGIE (South Italian Network for Rational Guidelines and International Epidemiology, 2014) project. We deep-sequenced the NS3/4A protease region of the viral population using the Ion Torrent Personal Genome Machine, and patient-specific majority rule consensus sequence summaries were constructed with a combination of freely available next generation sequencing data analysis software. We detected NS3/4A protease major and minor variants associated with resistance to boceprevir (V36L), telaprevir (V36L, I132V), simeprevir (V36L), and grazoprevir (V36L, V170I). Furthermore, we sequenced part of HCV NS5B polymerase using Sanger-sequencing and detected a natural RAS for dasabuvir (C316N). This mutation could be important for treatment strategies in cases of previous therapy failure.

  12. Detection of Natural Resistance-Associated Substitutions by Ion Semiconductor Technology in HCV1b Positive, Direct-Acting Antiviral Agents-Naïve Patients

    Directory of Open Access Journals (Sweden)

    Nadia Marascio

    2016-08-01

    Full Text Available Naturally occurring resistance-associated substitutions (RASs can negatively impact the response to direct-acting antivirals (DAAs agents-based therapies for hepatitis C virus (HCV infection. Herein, we set out to characterize the RASs in the HCV1b genome from serum samples of DAA-naïve patients in the context of the SINERGIE (South Italian Network for Rational Guidelines and International Epidemiology, 2014 project. We deep-sequenced the NS3/4A protease region of the viral population using the Ion Torrent Personal Genome Machine, and patient-specific majority rule consensus sequence summaries were constructed with a combination of freely available next generation sequencing data analysis software. We detected NS3/4A protease major and minor variants associated with resistance to boceprevir (V36L, telaprevir (V36L, I132V, simeprevir (V36L, and grazoprevir (V36L, V170I. Furthermore, we sequenced part of HCV NS5B polymerase using Sanger-sequencing and detected a natural RAS for dasabuvir (C316N. This mutation could be important for treatment strategies in cases of previous therapy failure.

  13. Research Advances on Coupling Agent for Thermoplastic Polymer/Natural Fibre Composites%偶联剂在热塑性聚合物/天然纤维复合材料中的研究进展

    Institute of Scientific and Technical Information of China (English)

    王真; 生瑜

    2012-01-01

    The coupling agent is an important aid.It can be divided into organic coupling agent,organic-inorganic coupling agent and inorganic coupling agent by its chemical composition.This review focuses on the mechanism and the effect of the various coupling agent applied to thermoplastic polymer/natural fibre composites.%偶联剂是一种重要的助剂,按化学组成可分为有机偶联剂、有机-无机偶联剂、无机偶联剂。文章重点阐述应用于热塑性聚合物/天然纤维复合材料中各种偶联剂的作用机理及改性效果。

  14. Bryostatin-1, a naturally occurring antineoplastic agent, acts as a Toll-like receptor 4 (TLR-4) ligand and induces unique cytokines and chemokines in dendritic cells.

    Science.gov (United States)

    Ariza, Maria Eugenia; Ramakrishnan, Rupal; Singh, Narendra P; Chauhan, Ashok; Nagarkatti, Prakash S; Nagarkatti, Mitzi

    2011-01-07

    Bryostatin-1 (Bryo-1), a natural macrocyclic lactone, is clinically used as an anti-cancer agent. In this study, we demonstrate for the first time that Bryo-1 acts as a Toll-like receptor 4 (TLR4) ligand. Interestingly, activation of bone marrow-derived dendritic cells (in vitro with Bryo-1) led to a TLR4-dependent biphasic activation of nuclear factor-κB (NF-κB) and the unique induction of cytokines (IL-5, IL-6, and IL-10) and chemokines, including RANTES (regulated on activation normal T cell expressed and secreted) and macrophage inflammatory protein 1α (MIP1-α). In addition, EMSA demonstrated that Bryo-1-mediated induction of RANTES was regulated by NF-κB and the interferon regulatory factors (IRF)-1, IRF-3, and IRF-7 to the RANTES independently of myeloid differentiation primary response gene-88 (MyD88). Bryo-1 was able to induce the transcriptional activation of IRF-3 through the TLR4/MD2-dependent pathway. In vivo administration of Bryo-1 triggered a TLR-4-dependent T helper cell 2 (Th2) cytokine response and expanded a subset of myeloid dendritic cells that expressed a CD11c(high)CD8α(-) CD11b(+)CD4(+) phenotype. This study demonstrates that Bryo-1 can act as a TLR4 ligand and activate innate immunity. Moreover, the ability of Bryo-1 to trigger RANTES and MIP1-α suggests that Bryo-1 could potentially be used to prevent HIV-1 infection. Finally, induction of a Th2 response by Bryo-1 may help treat inflammatory diseases mediated by Th1 cells. Together, our studies have a major impact on the clinical use of Bryo-1 as an anti-cancer and immunopotentiating agent.

  15. Use of natural coralline biomaterials as reinforcing and gas-forming agent for developing novel hybrid biomatrices: microarchitectural and mechanical studies.

    Science.gov (United States)

    Gravel, Mylène; Vago, Razi; Tabrizian, Maryam

    2006-03-01

    This paper describes the first attempt in fabrication of three-dimensional macroporous composites of chitosan and natural coralline material with pore sizes of 300-400 microm, exceeding the upper pore size limit of 250 microm obtained with freeze-dried chitosan-based scaffolds. Natural coral particulates of less than 20 microm, which is mainly composed of calcium carbonate (CaCO3), was simultaneously used as reinforcing phase and gas-forming agent to obtain a structure with large pores and improved mechanical and biological properties. The reaction between the coralline material and the acidic chitosan polymer solvent, which produced carbon dioxide, was rapidly stopped by the subsequent thermally induced phase separation technique, leaving coralline particulates in the polymeric structure. Scaffolds containing five different proportions of coralline material (0, 25, 50, 75, and 100 wt%) were investigated. The coralline-chitosan weight ratio was studied for its effects on the physical properties of the scaffolds. The relation between scaffold microarchitecture and mechanical properties was assessed with scanning electron microscope (SEM), along with micro-CT imaging and compression testing. The scaffolds were used in bone marrow cell culturing experiments to assess the effect of composition on cell behavior through cell-material interaction and morphological observation by SEM. Higher coralline concentration increased the pore wall thickness and favored large pore formation. Varying the coralline particulate to chitosan polymer ratio from 0 to 75 wt% increased the average pore size from 80 microm to 400 microm while the porosity decreased from 91% to 78%. The compressive modulus was improved proportionally with the coralline content, and the 75 wt% composites had a significantly higher modulus than other chitosan-based scaffold groups. More cells were observed on scaffolds with higher coralline content. The cell culture experiments indicated that the scaffolds

  16. Electron beam induced water-soluble silk fibroin nanoparticles as a natural antioxidant and reducing agent for a green synthesis of gold nanocolloid

    Science.gov (United States)

    Wongkrongsak, Soraya; Tangthong, Theeranan; Pasanphan, Wanvimol

    2016-01-01

    The research proposes a novel water-soluble silk fibroin nanoparticles (WSSF-NPs) created by electron beam irradiation. In this report, we demonstrate the effects of electron beam irradiation doses ranging from 1 to 30 kGy on the molecular weight (MW), nanostructure formation, antioxidant activity and reducing power of the WSSF-NPs. Electron beam-induced degradation of SF causing MW reduction from 250 to 37 kDa. Chemical characteristic functions of SF still remained after exposing to electron beam. The WSSF-NPs with the MW of 37 kDa exhibited spherical morphology with a nanoscaled size of 40 nm. Antioxidant activities and reducing powers were investigated using 2,2-diphenyl-1-picrylhryl free radical (DPPH•) scavenging activity and ferric reducing antioxidant power (FRAP) assays, respectively. The WSSF-NPs showed greater antioxidant activity and reducing power than non-irradiated SF. By increasing their antioxidant and reducing power efficiencies, WSSF-NPs potentially created gold nanocolloid. WSSF-NPs produced by electron beam irradiation would be a great merit for the uses as a natural antioxidant additive and a green reducing agent in biomedical, cosmetic and food applications.

  17. 18β-Glycyrrhetinic Acid, a Novel Naturally Derived Agent, Suppresses Prolactin Hyperactivity and Reduces Antipsychotic-Induced Hyperprolactinemia in In Vitro and In Vivo Models.

    Science.gov (United States)

    Wang, Di; Zhang, Yongfeng; Wang, Chunyue; Jia, Dongxu; Cai, Guangsheng; Lu, Jiahui; Wang, Di; Zhang, Zhang-Jin

    2016-09-01

    The purpose of this study was to examine the effects of 18β-glycyrrhetinic acid (GA), a novel naturally derived agent, in suppressing prolactin (PRL) hyperactivity and reducing antipsychotic-induced hyperprolactinemia (hyperPRL) and the underlying mechanisms in in vitro and in vivo models. GA treatment for 24 h inhibited PRL synthesis and secretion in MMQ cells and cultured pituitary cells in a dose-dependent fashion; but this effect was not reproduced in GH3 cells that lack the expression of functional dopamine D2 receptors. GA suppressed elevated PRL level and growth hormone, and normalized several sex hormones in a rat model of hyperPRL, produced by repeated injection of the dopamine blocker metoclopramide. GA also modulated the expression 5-HT1A and 5-HT2A receptors in both in vivo and in vitro models. These results indicate that GA is effective in suppressing PRL hyperactivity caused by the blockade of dopamine D2 receptors. This suppressive effect of GA may be related to its modulation of the serotonergic system. This study provides additional evidence in support of GA as an adjunct for the treatment of hyperPRL.

  18. Study on the structure-properties relationship of natural rubber/SiO2 composites modified by a novel multi-functional rubber agent

    Directory of Open Access Journals (Sweden)

    S. Y. Yang

    2014-06-01

    Full Text Available Vulcanization property and structure-properties relationship of natural rubber (NR/silica (SiO2 composites modified by a novel multi-functional rubber agent, N-phenyl- N'-(γ-triethoxysilane-propyl thiourea (STU, are investigated in detail. Results from the infrared spectroscopy (IR and X-ray photoelectron spectroscopy (XPS show that STU can graft to the surface of SiO2 under heating, resulting in a fine-dispersed structure in the rubber matrix without the connectivity of SiO2 particles as revealed by transmission electron microscopy (TEM. This modification effect reduces the block vulcanization effect of SiO2 for NR/SiO2/STU compounds under vulcanization process evidently. The 400% modulus and tensile strength of NR/SiO2/STU composites are much higher than that of NR/SiO2/TU composites, although the crystal index at the stretching ratio of 4 and crosslinking densities of NR/SiO2 composites are almost the same at the same dosage of SiO2. Consequently, a structure-property relationship of NR/SiO2/STU composites is proposed that the silane chain of STU can entangle with NR molecular chains to form an interfacial region, which is in accordance with the experimental observations quite well.

  19. Comparison of the nucleotide sequences of 16S rRNA, 444 Ep-ank, and groESL heat shock operon genes in naturally occurring Ehrlichia equi and human granulocytic ehrlichiosis agent isolates from Northern California.

    Science.gov (United States)

    Chae, J S; Foley, J E; Dumler, J S; Madigan, J E

    2000-04-01

    We examined 11 naturally occurring isolates of Ehrlichia equi in horses and two human granulocytic ehrlichiosis agent isolates in California for sequence diversity in three genes. Ehrlichia equi isolates were from Sierra (n = 6), Mendocino (n = 3), Sonoma (n = 1), and Marin (n = 1) counties, and human granulocytic ehrlichiosis (HGE) agent isolates were obtained from Humboldt county. PCR with specific primers for 16S rRNA, 444 Ep-ank and groESL heat shock operon genes successfully produced amplicons for all 13 clinical samples. The 444 Ep-ank gene of the HGE agent and E. equi isolates from northern California is different from the eastern U.S. isolates BDS and USG3. The translated amino acid sequence of the groESL heat shock operon gene fragment is identical among E. equi, the HGE agent, and E. phagocytophila, with the exception of the northern Californian equine CASOLJ isolate. Microheterogeneity was observed in the 16S rRNA gene sequences of HGE agent and E. equi isolates from northern California. These results suggest that E. equi and the HGE agent found in California are similar or identical but may differ from the isolates of equine and human origin found in the eastern United States.

  20. Relação entre a lagarta-do-cartucho e seus agentes de controle biológico natural na produção de milho Relationship between fall armyworm and their natural biological control agents in the maize crop

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes Corrêa Figueiredo

    2006-12-01

    Full Text Available Este trabalho teve como objetivo quantificar as perdas na cultura do milho BRS 3123 decorrentes do ataque da lagarta-do-cartucho (Spodoptera frugiperda, na ausência e presença de seus inimigos naturais. Aos 15 dias depois da emergência da planta, foi realizada uma infestação artificial da praga (uma postura por metro quadrado. As lagartas alimentaram-se da planta, sem a interferência de seus inimigos naturais, pela utilização de uma gaiola de proteção (inicial, de dois dias depois da infestação, até uma proteção máxima de 16 dias. O dano da praga, determinado por uma escala de notas de 0 (plantas sem dano a 5 (plantas mortas, foi em média de 4,01, 1,39, 1,09 e 0,93 para o período de proteção da praga de 16, 6, 4 e 2 dias, respectivamente. Na ausência de agentes de controle biológico, o ataque da praga ocasionou perdas na produção de matéria seca de 47,27% e perdas no rendimento de grãos de 54,49%. Os resultados evidenciaram a importância dos inimigos naturais na supressão de lagartas de S. frugiperda na cultura de milho.This work had the objective of quantifying the losses in the maize hybrid BRS 3123 due to the attack of fall armyworm (Spodoptera frugiperda, in the absence or presence of its natural enemies. Fifteen days after the plant emergency, an artificial infestation (one egg mass per square meter was accomplished. The larvae fed on the plant, without the interference of its natural enemies, by using an appropriated protection cage (initial protection for two days after infestation, until a maximum protection period of 16 days. The damage caused by the pest, determined through a visual scale from 0 (plants without damage to 5 (dead plants, was on average, 4.01, 1.39, 1.09 and 0.93 for the pest protection period of 16, 6, 4 and 2 days, respectively. In the absence of the biological control agents, the attack of the pest caused losses of 47.27% in the dry matter production and losses of 54.49% in grain yield. The

  1. Adsorption Study on Moringa Oleifera Seeds and Musa Cavendish as Natural Water Purification Agents for Removal of Lead, Nickel and Cadmium from Drinking Water

    Science.gov (United States)

    Aziz, N. A. A.; Jayasuriya, N.; Fan, L.

    2016-07-01

    The effectiveness of plant based materials Moringa oleifera (Moringa) seeds and Musa cavendish (banana peel) for removing heavy metals namely lead (Pb), nickel (Ni) and cadmium (Cd) from contaminated groundwater was studied. Tests were carried out with individual and combined biomass at neutral pH condition on synthetic groundwater samples. The optimum biomass doses were determined as 200 mg/L for single biomass and 400 mg/L (in the ratio of 200 mg/L: 200 mg/L) for combined biomasses and used for adsorption isotherm studies with contact time of 30 minutes. Results showed that combined biomasses was able to met the Pb, Ni and Cd WHO standards from higher Pb, Ni and Cd initial concentrations which were up to 40 µg/L, 50 µg/L 9 µg/L, respectively compared to individual biomass of Moringa seed and banana peel. Moringa seeds exhibited the highest removal of Pb (81%) while the combined biomasses was most effective in removing Ni (74%) and Cd (97%) over wider their initial concentration ranges. The experimental data were linearized with Langmuir and Freundlich adsorption isotherm models. Freundlich model described the Pb adsorption better than the Langmuir model for all the tested biomasses. However, the Langmuir model fit better with the experimental data of Ni adsorption by Moringa seeds. Both models showed negligible differences in the coefficient of determination (R2) when applied for Ni and Cd adsorption on banana peel and combined biomasses, suggesting that there were multiple layers on the biomass interacting with the metals. Chemisorption is suggested to be involved in Pb adsorption for all tested biomasses as the value of nF calculated was lower than one. This type of adsorption could explain the phenomenon of different behavior of Pb removal and the higher Pb adsorption capacity (represented by KF values) compared to Ni and Cd. The study demonstrates that Moringa seeds, banana peel and their combination have the potential to be used as a natural alternative

  2. Application of natural protein anti-dandruff Sl antipruritic agent in cosmetics and its prospect%天然蛋白去屑止痒剂在化妆品中的应用与展望

    Institute of Scientific and Technical Information of China (English)

    胡梅; 彭巍; 李海军

    2012-01-01

    概述了头皮屑及其形成的机理,同时介绍了新型去屑止痒剂——天然蛋白去屑止痒剂的产品性能及其在日化行业中的应用情况,并对该产品在日化行业中的应用进行了展望。%This paper described dandruff and its folination mechanism firstly. Then, it introduced the performance of a new anti-dandruff & antipruritic agent, a natural protein product which aimed at anti-dandruff & antipruritic, and its current application in daily chemical products Meanwhile, it prospected the future application of this natural protein dandruff & antipruritic agent in daily chemical industry.

  3. Moral actor, selfish agent.

    Science.gov (United States)

    Frimer, Jeremy A; Schaefer, Nicola K; Oakes, Harrison

    2014-05-01

    People are motivated to behave selfishly while appearing moral. This tension gives rise to 2 divergently motivated selves. The actor-the watched self-tends to be moral; the agent-the self as executor-tends to be selfish. Three studies present direct evidence of the actor's and agent's distinct motives. To recruit the self-as-actor, we asked people to rate the importance of various goals. To recruit the self-as-agent, we asked people to describe their goals verbally. In Study 1, actors claimed their goals were equally about helping the self and others (viz., moral); agents claimed their goals were primarily about helping the self (viz., selfish). This disparity was evident in both individualist and collectivist cultures, attesting to the universality of the selfish agent. Study 2 compared actors' and agents' motives to those of people role-playing highly prosocial or selfish exemplars. In content (Study 2a) and in the impressions they made on an outside observer (Study 2b), actors' motives were similar to those of the prosocial role-players, whereas agents' motives were similar to those of the selfish role-players. Study 3 accounted for the difference between the actor and agent: Participants claimed that their agent's motives were the more realistic and that their actor's motives were the more idealistic. The selfish agent/moral actor duality may account for why implicit and explicit measures of the same construct diverge, and why feeling watched brings out the better angels of human nature.

  4. Deguelin‐induced blockade of PI3K/protein kinase B/MAP kinase signaling in zebrafish and breast cancer cell lines is mediated by down‐regulation of fibroblast growth factor receptor 4 activity

    OpenAIRE

    Wu, Wei; Hai, Yang; Chen, Lu; Liu, Rui‐Jin; Han, Yu‐Xiang; Li, Wen‐Hao; Li, Song; Lin, Shuo; Wu, Xin‐Rong

    2016-01-01

    Abstract Deguelin, a natural component derived from leguminous plants, has been used as pesticide in some regions. Accumulating evidence show that deguelin has promising chemopreventive and therapeutic activities against cancer cells. This study shows that low concentrations of deguelin can lead to significant delay in zebrafish embryonic development through growth inhibition and induction of apoptosis. Furthermore, we identified fibroblast growth factor receptor 4 (FGFR4) as the putative tar...

  5. Toward a Theory-Based Natural Language Capability in Robots and Other Embodied Agents: Evaluating Hausser's SLIM Theory and Database Semantics

    Science.gov (United States)

    Burk, Robin K.

    2010-01-01

    Computational natural language understanding and generation have been a goal of artificial intelligence since McCarthy, Minsky, Rochester and Shannon first proposed to spend the summer of 1956 studying this and related problems. Although statistical approaches dominate current natural language applications, two current research trends bring…

  6. The Present Situation and Prospect of Nature Food Antiseptic and Preservation Agent%天然食品防腐保鲜剂的发展现状及前景

    Institute of Scientific and Technical Information of China (English)

    张海霞

    2015-01-01

    The natural food preservative agent is an additive in food processing, which plays an extremely important role in food preservation. However, it is not reasonable to use of natural food additives, this will have a bad impact on food quality, and food safety is threatened. Therefore, according to the development of natural food preservative agent, according to the actual situation of the development of natural food preservative, combining with the actual situation of social development, this paper analyzed its development prospect, and the relevant opinions and suggestions of the use of natural food antiseptic was put forward.%天然食品防腐保鲜剂是食品加工中必须加入的添加剂,其对食品保鲜起着极为重要的作用。但是,不合理地使用天然食品添加剂,会对食品质量造成不良的影响,使得食品的安全受到一定的威胁。因此,针对天然食品防腐保鲜剂的发展进行具体分析,根据天然食品防腐保鲜剂发展的实际情况,结合社会发展实际,分析其发展的前景,并对天然食品防腐保鲜剂的使用提出相关的意见和建议。

  7. Bioactive Natural Product and Superacid Chemistry for Lead Compound Identification: A Case Study of Selective hCA III and L-Type Ca2+ Current Inhibitors for Hypotensive Agent Discovery

    Directory of Open Access Journals (Sweden)

    Hélène Carreyre

    2017-05-01

    Full Text Available Dodoneine (Ddn is one of the active compounds identified from Agelanthus dodoneifolius, which is a medicinal plant used in African pharmacopeia and traditional medicine for the treatment of hypertension. In the context of a scientific program aiming at discovering new hypotensive agents through the original combination of natural product discovery and superacid chemistry diversification, and after evidencing dodoneine’s vasorelaxant effect on rat aorta, superacid modifications allowed us to generate original analogues which showed selective human carbonic anhydrase III (hCA III and L-type Ca2+ current inhibition. These derivatives can now be considered as new lead compounds for vasorelaxant therapeutics targeting these two proteins.

  8. Gluten-free pasta incorporating chia (Salvia hispanica L.) as thickening agent: An approach to naturally improve the nutritional profile and the in vitro carbohydrate digestibility.

    Science.gov (United States)

    Menga, Valeria; Amato, Mariana; Phillips, Tim D; Angelino, Donato; Morreale, Federico; Fares, Clara

    2017-04-15

    A gluten-free pasta was prepared adding chia at rice flour for testing the thickening and nutritional properties of this specie. Chemical analysis showed chia is a source of protein (19.52% and 15.81%, seeds and mucilage respectively), insoluble/soluble dietary fiber ratio (4.3 and 1.79 seeds and mucilage respectively), fat and ash content. The total phenolic acids content ranged from 734.5μg/g to 923.9μg/g for seeds and mucilage respectively. Chia was a good thickening agent and, improved the nutritional profile of enriched samples compared to CGF. After cooking TPAs increased in all samples, ranging from 5.3% in DW to 52.8% in CM5. The addition of chia seeds also increased the slowly digestible starch fraction of rice flour, commonly known to have a high glycemic index. Results suggest that chia should be added as thickening agent in the formulation of GF pasta for conferring healthier characteristics.

  9. Natural product-based design, synthesis and biological evaluation of anthra[2,1-d]thiazole-6,11-dione derivatives from rhein as novel antitumour agents.

    Science.gov (United States)

    Liang, Yu-Kun; Yue, Zhi-Zhou; Li, Jia-Xin; Tan, Cun; Miao, Ze-Hong; Tan, Wen-Fu; Yang, Chun-Hao

    2014-09-12

    Two series of novel 2-substituted 5,7-dihydroxyanthra[2,1-d]thiazole-6,11-dione derivatives from natural rhein were designed, synthesized and evaluated for their antitumour activities against human cancer cell lines A549 and HeLa in vitro.

  10. Studies on chemical modification and biology of a natural product, gambogic acid (II): Synthesis and bioevaluation of gambogellic acid and its derivatives from gambogic acid as antitumor agents.

    Science.gov (United States)

    Wang, Jinxin; Ma, Junhai; You, Qidong; Zhao, Li; Wang, Fan; Li, Chong; Guo, Qinglong

    2010-09-01

    Gambogic acid (GA) has been reported to be a potent apoptosis inducer. The fact that it is amenable to chemical modification makes GA an attractive molecule for the development of anticancer agents. We firstly reported the synthesis of gambogellic acid, which was generated under acid catalysis from readily available GA by a base-catalyzed diene intramolecular annelation. Sequentially, thirteen new compounds were synthesized and their inhibitory activity on HT-29, Bel-7402, BGC-823, and A549 cell lines were evaluated in vitro by MTT assay, and (38, 40)-epoxy-33-chlorogambogellic acid (4) was identified as a BGC-823 cell apoptosis inducer through MTT cell assay, observations of morphological changes, and Annexin-V/PI double-staining assay. Compound 4 showed significant effects in inducing apoptosis and might serve as a potential lead compound for discovery of new anticancer drugs. Further structure-activity relationships (SARs) of gambogic acid derivatives were discussed.

  11. The need for agents

    DEFF Research Database (Denmark)

    Abolfazlian, Ali Reza Kian

    1996-01-01

    I denne artikel arbejder vi med begrebet Intelligent Software Agents (ISAs), som autonomous, social, reactive, proactive og subservient computer systemer. Baseret på socialt psykologiske argumenter viser jeg endvidere, hvordan både den menneskelige natur og det teknologiske stadium, som mennesket...

  12. Socially Intelligent Tutor Agents

    NARCIS (Netherlands)

    Heylen, Dirk K.J.; Nijholt, Antinus; op den Akker, Hendrikus J.A.; Vissers, M.; Aylett, R.; Ballin, D.; Rist, T.

    2003-01-01

    Emotions and personality have received quite a lot of attention the last few years in research on embodied conversational agents. Attention is also increasingly being paid to matters of social psychology and interpersonal aspects, for work of our group). Given the nature of an embodied

  13. [Uricosuric agent].

    Science.gov (United States)

    Ohno, Iwao

    2008-04-01

    Urate lowering treatment is indicated in patients with recurrent acute attacks, tophi, gouty arthropathy, radiographic changes of gout, multiple joint involvement, or associated uric acid nephrolithiasis. Uricosuric agents like benzbromarone and probenecid are very useful to treat hyperuricemia as well as allopurinol (xanthine oxidase inhibitor). Uricosuric agents act the urate lowering effect through blocking the URAT1, an urate transporter, in brush border of renal proximal tubular cells. In order to avoid the nephrotoxicity and urolithiasis due to increasing of urinary urate excretion by using uricosuric agents, the proper urinary tract management (enough urine volume and correction of aciduria) should be performed.

  14. Differential effects of natural product microtubule stabilizers on microtubule assembly: single agent and combination studies with taxol, epothilone B, and discodermolide.

    Science.gov (United States)

    Gertsch, Jürg; Meier, Sarah; Müller, Martin; Altmann, Karl-Heinz

    2009-01-01

    A systematic comparison has been performed of the morphology and stability of microtubules (MTs) induced by the potent microtubule-stabilizing agents (MSAs) taxol, epothilone B (Epo B), and discodermolide (DDM) under GTP-free conditions. DDM-induced tubulin polymerization occurred significantly faster than that induced by taxol and Epo B. At the same time, tubulin polymers assembled from soluble tubulin by DDM were morphologically distinct (shorter and less ordered) from those induced by either taxol or Epo B, as demonstrated by electron microscopy. Exposure of MSA-induced tubulin polymers to ultrasound revealed the DDM-based polymers to be less stable to this type of physical stress than those formed with either Epo B or taxol. Interestingly, MT assembly in the presence of both DDM and taxol appeared to produce a distinct new type of MT polymer with a mixed morphology between those of DDM- and taxol-induced structures. The observed differences in MT morphology and stability might be related, at least partly, to differences in intramicrotubular tubulin isotype distribution, as DDM showed a different pattern of beta-tubulin isotype usage in the assembly process.

  15. New tricks for an old natural product: discovery of highly potent evodiamine derivatives as novel antitumor agents by systemic structure-activity relationship analysis and biological evaluations.

    Science.gov (United States)

    Dong, Guoqiang; Wang, Shengzheng; Miao, Zhenyuan; Yao, Jianzhong; Zhang, Yongqiang; Guo, Zizhao; Zhang, Wannian; Sheng, Chunquan

    2012-09-13

    Evodiamine is a quinazolinocarboline alkaloid isolated from the fruits of traditional Chinese herb Evodiae fructus . Previously, we identified N13-substituted evodiamine derivatives as potent topoisomerase I inhibitors by structure-based virtual screening and lead optimization. Herein, a library of novel evodiamine derivatives bearing various substitutions or modified scaffold were synthesized. Among them, a number of evodiamine derivatives showed substantial increase of the antitumor activity, with GI(50) values lower than 3 nM. Moreover, these highly potent compounds can effectively induce the apoptosis of A549 cells. Interestingly, further computational target prediction calculations in combination with biological assays confirmed that the evodiamine derivatives acted by dual inhibition of topoisomerases I and II. Moreover, several hydroxyl derivatives, such as 10-hydroxyl evodiamine (10j) and 3-amino-10-hydroxyl evodiamine (18g), also showed good in vivo antitumor efficacy and low toxicity at the dose of 1 mg/kg or 2 mg/kg. They represent promising candidates for the development of novel antitumor agents.

  16. Vasoactive Agents

    OpenAIRE

    Husedzinovic, Ino; Bradic, Nikola; Goranovic, Tanja

    2006-01-01

    This article is a short review of vasoactive drugs which are in use in todays clinical practice. In the past century, development of vasoactive drugs went through several phases. All of these drugs are today divided into several groups, depending on their place of action, pharmacological pathways and/or effects on target organ or organ system. Hence, many different agents are today in clinical practice, we have shown comparison between them. These agents provide new directions in the treatmen...

  17. [Inotropic agents].

    Science.gov (United States)

    Sasayama, Shigetake

    2003-05-01

    Depression of myocardial contractility plays an important role in the development of heart failure and many inotropic agents were developed to improve the contractile function of the failing heart. Agents that increase cyclic AMP, either by increasing its synthesis or reducing its degradation, exerted dramatic short-term hemodynamic benefits, but these acute effects were not extrapolated into long-term improvement of the clinical outcome of heart failure patients. Administration of these agents to an energy starved failing heart would be expected to increase myocardial energy use and could accelerate disease progression. The role of digitalis in the management of heart failure has been controversial, however, the recent large scale clinical trial has ironically proved that digoxin reduced the rate of hospitalization both overall and for worsening heart failure. More recently, attention was paid to other inotropic agents that have a complex and diversified mechanism. These agents have some phosphodiesterase-inhibitory action but also possess additional effects, including cytokine inhibitors, immunomodulators, or calcium sensitizers. In the Western Societies these agents were again shown to increase mortality of patients with severe heart failure in a dose dependent manner with the long-term administration. However, it may not be the case in the Japanese population in whom mortality is relatively low. Chronic treatment with inotropic agent may be justified in Japanese, as it allows optimal care in the context of relief of symptoms and an improved quality of life. Therefore, each racial group should obtain specific evidence aimed at developing its own guidelines for therapy rather than translating major guidelines developed for other populations.

  18. Black-backed jackals (Canis mesomelas) are natural hosts of Babesia rossi, the virulent causative agent of canine babesiosis in sub-Saharan Africa.

    Science.gov (United States)

    Penzhorn, Barend L; Vorster, Ilse; Harrison-White, Robert F; Oosthuizen, Marinda C

    2017-03-13

    Babesia rossi, which is transmitted by Haemaphysalis spp. and is highly virulent to domestic dogs, occurs only in sub-Saharan Africa. Since dogs are not native to the region, it has been postulated that the natural host of B. rossi is an indigenous African canid. Although various attempts at artificial infection indicated that black-backed jackals (Canis mesomelas) could become subclinically infected with B. rossi, data on occurrence of B. rossi in free-ranging jackals was lacking. A long-term behaviour study in which free-ranging black-backed jackals were radio-collared offered the opportunity of collecting blood specimens from a large number of free-ranging jackals. Genomic DNA was extracted from the EDTA blood samples (n = 107). PCR products were subjected to Reverse Line Blot hybridization using Theileria and Babesia genera-specific as well as 28 species-specific oligonucleotide probes, including Babesia canis, Babesia rossi, Babesia vogeli and Babesia gibsoni. The near full-length parasite 18S rRNA gene was amplified from two selected samples (free-ranging jackals), cloned and a total of six recombinants were sequenced. Of 91 free-ranging jackals, 77 (84.6%) reacted with the Babesia genus-specific probe; 27 (29.7%) also reacted with the B. rossi probe. Of 16 captive jackals, 6 (37.5%) reacted with the B. rossi probe, while one further sample reacted with the Babesia genus-specific probe only. After cloning, 6 recombinants yielded identical sequences identical to that of B. rossi (L19079) and differing by 2 base pairs from B. rossi (DQ111760) in GenBank. The observed sequence similarities were confirmed by phylogenetic analyses using neighbour joining and maximum parsimony. Black-backed jackals are natural hosts of B. rossi.

  19. Developing Enculturated Agents

    DEFF Research Database (Denmark)

    Rehm, Matthias

    2010-01-01

    Embodied Conversational Agents (ECAs) are complex multimodal systems with rich verbal and nonverbal repertoires. There human-like appearance raises severe expectations regarding natural communicative behaviors on the side of the user. But what is regarded as “natural” is to a large degree dependent...... on our cultural profiles that provide us with heuristics of behavior and interpretation. Thus, integrating cultural aspects of communicative behaviors in virtual agents and thus enculturating such systems seems to be inevitable. But culture is a multi-defined domain and thus a number of pitfalls arise...

  20. Sunscreening Agents

    Science.gov (United States)

    Martis, Jacintha; Shobha, V; Sham Shinde, Rutuja; Bangera, Sudhakar; Krishnankutty, Binny; Bellary, Shantala; Varughese, Sunoj; Rao, Prabhakar; Naveen Kumar, B.R.

    2013-01-01

    The increasing incidence of skin cancers and photodamaging effects caused by ultraviolet radiation has increased the use of sunscreening agents, which have shown beneficial effects in reducing the symptoms and reoccurrence of these problems. Many sunscreen compounds are in use, but their safety and efficacy are still in question. Efficacy is measured through indices, such as sun protection factor, persistent pigment darkening protection factor, and COLIPA guidelines. The United States Food and Drug Administration and European Union have incorporated changes in their guidelines to help consumers select products based on their sun protection factor and protection against ultraviolet radiation, whereas the Indian regulatory agency has not yet issued any special guidance on sunscreening agents, as they are classified under cosmetics. In this article, the authors discuss the pharmacological actions of sunscreening agents as well as the available formulations, their benefits, possible health hazards, safety, challenges, and proper application technique. New technologies and scope for the development of sunscreening agents are also discussed as well as the role of the physician in patient education about the use of these agents. PMID:23320122

  1. Detection of naturally infected vector ticks (acari: ixodidae by different species of babesia and theileria agents from three different enzootic parts of iran.

    Directory of Open Access Journals (Sweden)

    Mohammad Abdigoudarzi

    2013-12-01

    Full Text Available Diagnostic study of vector ticks for different pathogens transmitted specifically have been done by Iranian old scientists working on the basis of biological transmission of pathogens. In this study we decided to confirm natural infection of different collected ticks from three different provinces of Iran.Ticks were collected from livestock (sheep, goats and cattle during favorable seasons (April to September 2007 and 2008. Slide preparations were stained by Giemsa and Feulgen and were studied searching for any trace of infection. Positive DNA from infected blood or tissue samples was provided and was used as positive control. First, PCR optimization for positive DNA was done, and then tick samples were subjected to specific PCR.Eleven pairs of primers were designed for detection of Theileria, Babesia and Anaplasma spp. Totally 21 tick samples were detected to be infected with protozoa. Hyalomma anatolicum anatolicum and Rhipicephalus turanicus from Fars Province were infected with T. lestoquardi at two different places. Hyalomma detritum was infected with T. lestoquardi in Lorestan Province and Rh. turanicus was infected to Ba. ovis from Fars Province.Totally 21 tick samples were detected to be infected with protozoa. Every sample is regarded with host-environment related factors. Since there are complex relations of vectors and their relevant protozoa, different procedures are presented for future studies.

  2. Exploration on natural product anibamine side chain modification toward development of novel CCR5 antagonists and potential anti-prostate cancer agents.

    Science.gov (United States)

    Xu, Guoyan G; Zaidi, Saheem A; Zhang, Feng; Singh, Shilpa; Raborg, Thomas J; Yuan, Yunyun; Zhang, Yan

    2015-09-01

    Prostate cancer is one of the leading causes of death among males in the world. Prostate cancer cells have been shown to express upregulated chemokine receptor CCR5, a G protein-coupled receptor (GPCR) that relates to the inflammation process. Anibamine, a natural product containing a pyridine ring and two aliphatic side chains, was shown to carry a binding affinity of 1 μM at CCR5 as an antagonist with potential anti-cancer activity. However, it is not drug-like according to the Lipinski's rule of five mainly due to its two long aliphatic side chains. In our effort to improve its drug-like property, a series of anibamine derivatives were designed and synthesized by placement of aromatic side chains through an amide linkage to the pyridine ring. The newly synthesized compounds were tested for their CCR5 affinity and antagonism, and potential anti-proliferation activity against prostate cancer cell lines. Basal cytotoxicity was finally studied for compounds showing potent anti-proliferation activity. It was found that compounds with hydrophobic substitutions on the aromatic systems seemed to carry more promising CCR5 binding and prostate cancer cell proliferation inhibition activities.

  3. Aqueous two-phase system cold-set gelation using natural and recombinant probiotic lactic acid bacteria as a gelling agent.

    Science.gov (United States)

    Léonard, Lucie; Husson, Florence; Langella, Philippe; Châtel, Jean-Marc; Saurel, Rémi

    2016-05-01

    The present study aimed to entrap probiotic lactic acid bacteria (LAB) in a sodium alginate and sodium caseinate aqueous two-phase gel system. The natural acidifying properties of two therapeutic probiotic LAB were exploited to liberate calcium ions progressively from calcium carbonate (CaCO3), which caused the gelation of the co-existing phases. Bi-biopolymeric matrix gelation of GDL/CaCO3 or LAB/CaCO3 was monitored by dynamic rheological measurements, and the final gels were characterized by frequency dependence measurements and confocal laser scanning microscopy. Weak to strong gels were formed with an elastic modulus G' from 10 to 1.000Pa, respectively. After cold-set gelation of our system, confocal laser scanning microscopy showed spherical protein microdomains trapped within a calcium alginate network. LAB cells were stained to study their partition in the self-gelling matrices. Our LAB strains showed two different behaviors, which may relate to the exopolysaccharide production: (i) Lactobacillus plantarum CNRZ1997 cells were found mainly in continuous alginate networks, whereas (ii) Lactococcus lactis cells were localized in protein microdomains. This alginate-caseinate phase-separated system that was self-gelled by LAB cells may be an innovative approach for immobilizing and protecting LAB cells.

  4. Natural Prenylchalconaringenins and Prenylnaringenins as Antidiabetic Agents: α-Glucosidase and α-Amylase Inhibition and in Vivo Antihyperglycemic and Antihyperlipidemic Effects.

    Science.gov (United States)

    Sun, Hua; Wang, Dong; Song, Xiaotong; Zhang, Yazhou; Ding, Weina; Peng, Xiaolin; Zhang, Xiaoting; Li, Yashan; Ma, Ying; Wang, Runling; Yu, Peng

    2017-03-01

    Inhibition of α-glucosidase and α-amylase decreases postprandial blood glucose levels and delays glucose absorption, making it a treatment strategy for type 2 diabetes. This study examined in vivo and in vitro antidiabetic activities of natural prenylchalconaringenins 1 and 2 and prenylnaringenins 3 and 4, found in hops and beer. 3'-Geranylchalconaringenin (2) competitively and irreversibly inhibited α-glucosidase (IC50 = 1.08 μM) with activity 50-fold higher than that of acarbose (IC50 = 51.30 μM) and showed moderate inhibitory activity against α-amylase (IC50 = 20.46 μM). Docking analysis substantiated these findings. In addition, compound 2 suppressed the increase in postprandial blood glucose levels and serum levels of total cholesterol and triglycerides in streptozotocin-induced diabetic mice. Taken together, these results suggest that 2 has dual inhibitory activity against α-glucosidase and α-amylase and alleviates diabetic hyperglycemia and hyperlipidemia, making it a potential functional food ingredient and drug candidate for management of type 2 diabetes.

  5. The influence of oscillating electromagnetic fields on membrane structure and function: Synthetic liposome and natural membrane bilayer systems with direct application to the controlled delivery of chemical agents

    Energy Technology Data Exchange (ETDEWEB)

    Liburdy, R.P.; de Manincor, D.; Fingado, B.

    1989-09-01

    Investigations have been conducted to determine if an imposed electromagnetic field can influence membrane transport, and ion and drug permeability in both synthetic and natural cell membrane systems. Microwave fields enhance accumulation of sodium in the lymphocyte and induce protein shedding at Tc. Microwaves also trigger membrane permeability of liposome systems under specific field exposure conditions. Sensitivity varies in a defined way in bilayers displaying a membrane structural phase transition temperature, Tc; maximal release was observed at or near Tc. Significantly, liposome systems without a membrane phase transition were also found to experience permeability increases but, in contrast, this response was temperature independent. The above results indicate that field-enhanced drug release occurs in liposome vesicles that possess a Tc as well as non-Tc liposomes. Additional studies extend non-Tc liposome responses to the in vivo case in which microwaves trigger Gentamicin release from a liposome depot'' placed subcutaneously in the rat hind leg. In addition, evidence is provided that cell surface sequestered liposomes can be triggered by microwave fields to release drugs directly into target cells. 24 refs., 6 figs.

  6. Mobile Agents

    Science.gov (United States)

    Satoh, Ichiro

    Mobile agents are autonomous programs that can travel from computer to computer in a network, at times and to places of their own choosing. The state of the running program is saved, by being transmitted to the destination. The program is resumed at the destination continuing its processing with the saved state. They can provide a convenient, efficient, and robust framework for implementing distributed applications and smart environments for several reasons, including improvements to the latency and bandwidth of client-server applications and reducing vulnerability to network disconnection. In fact, mobile agents have several advantages in the development of various services in smart environments in addition to distributed applications.

  7. Influence of the nature of pre-contraction on the responses to commonly employed vasodilator agents in rat-isolated aortic rings.

    Science.gov (United States)

    Streefkerk, Jörn O; de Groot, Annemieke A; Pfaffendorf, Martin; van Zwieten, Pieter A

    2002-12-01

    The relaxing properties of vasodilator drugs in vitro may depend on the characteristics of the contractile state of the vessel investigated. Rat-isolated thoracic aortas were exposed to different types of pre-contraction. The following vasoconstrictor agents were used: phenylephrine (PhE), a selective alpha1-adrenoceptor agonist; St 587, a partial alpha1-adrenoceptor stimulant; U46619 (U-46). a thromboxane A2 agonist: and potassium ions causing receptor-independent depolarization of the membrane. After pre-contraction, various differential vasodilator drugs were investigated: methacholine (MCh, endothelium dependent), sodium nitroprusside (SNP, NO donor), forskolin (FSK, adenylyl cyclase stimulant) and nifedipine, a Ca2+-antagonist (selective L-type calcium antagonist). The vasodilator activity of these compounds was quantified by their vasodilator potency value (pD2) and efficacy (Emax) obtained from their concentration-response curves. PhE (0.1, 0.3, 3 microM) caused isometric responses of 4.8 +/- 0.3, 6.5 +/- 0.3 and 7.8 +/- 0.5 mN, respectively. An increase of the PhE concentration from 0.1 to 3 microM did not influence the response to FSK while it reduced the pD2 of SNP (8.6 +/- 0.1 to 7.35 +/- 0.1). Under these conditions, only the Emax of MCh was reduced (96.3 +/- 4.3% to 43.3 +/- 6.9%). U46 (0.18, 0.3, 1 microM) increased the contractile force by 7.4 +/- 0.4, 8.8 +/- 0.3 and 10.4 +/- 0.3 mN, respectively. Increasing the concentration of U-46 from 0.18 to 1 microM affected only the efficacy of SNP (84 +/- 4.4% to 17 +/- 8.8%) and MCh (64.5 +/- 12.3% to 0.0 +/- 9.2%) and reduced the potency of FSK (7.91 +/- 0.26 to 7.15 +/- 0.10). The concentration of K+-ions from 25 to 30 and 40 mM increased the contractile force by 4.0 +/- 0.4, 7.0 +/- 0.5 and 10.8 +/- 0.4 mN, respectively. The increase in [K+] caused a potency decrease of FSK (7.1 +/- 0.0 to 5.8 +/- 0.0) whereas both efficacy and potency were reduced for SNP (95.6 +/- 1.8% to 65.8 +/- 1.9% and 8.7 +/- 0

  8. Polish natural bee honeys are anti-proliferative and anti-metastatic agents in human glioblastoma multiforme U87MG cell line.

    Directory of Open Access Journals (Sweden)

    Justyna Moskwa

    Full Text Available Honey has been used as food and a traditional medicament since ancient times. However, recently many scientists have been concentrating on the anti-oxidant, anti-proliferative, anti-inflammatory and other properties of honey. In this study, we investigated for the first time an anticancer effect of different honeys from Poland on tumor cell line - glioblastoma multiforme U87MG. Anti-proliferative activity of honeys and its interferences with temozolomide were determined by a cytotoxicity test and DNA binding by [H3]-thymidine incorporation. A gelatin zymography was used to conduct an evaluation of metalloproteinases (MMP-2 and MMP-9 expression in U87MG treatment with honey samples. The honeys were previously tested qualitatively (diastase activity, total phenolic content, lead and cadmium content. The data demonstrated that the examined honeys have a potent anti-proliferative effect on U87MG cell line in a time- and dose-dependent manner, being effective at concentrations as low as 0.5% (multifloral light honey - viability 53% after 72 h of incubation. We observed that after 48 h, combining honey with temozolomide showed a significantly higher inhibitory effect than the samples of honey alone. We observed a strong inhibition of MMP-2 and MMP-9 for the tested honeys (from 20 to 56% and from 5 to 58% compared to control, respectively. Our results suggest that Polish honeys have an anti-proliferative and anti-metastatic effect on U87MG cell line. Therefore, natural bee honey can be considered as a promising adjuvant treatment for brain tumors.

  9. Cysteine S-conjugate β-lyases: important roles in the metabolism of naturally occurring sulfur and selenium-containing compounds, xenobiotics and anticancer agents.

    Science.gov (United States)

    Cooper, Arthur J L; Krasnikov, Boris F; Niatsetskaya, Zoya V; Pinto, John T; Callery, Patrick S; Villar, Maria T; Artigues, Antonio; Bruschi, Sam A

    2011-06-01

    Cysteine S-conjugate β-lyases are pyridoxal 5'-phosphate-containing enzymes that catalyze β-elimination reactions with cysteine S-conjugates that possess a good leaving group in the β-position. The end products are aminoacrylate and a sulfur-containing fragment. The aminoacrylate tautomerizes and hydrolyzes to pyruvate and ammonia. The mammalian cysteine S-conjugate β-lyases thus far identified are enzymes involved in amino acid metabolism that catalyze β-lyase reactions as non-physiological side reactions. Most are aminotransferases. In some cases the lyase is inactivated by reaction products. The cysteine S-conjugate β-lyases are of much interest to toxicologists because they play an important key role in the bioactivation (toxication) of halogenated alkenes, some of which are produced on an industrial scale and are environmental contaminants. The cysteine S-conjugate β-lyases have been reviewed in this journal previously (Cooper and Pinto in Amino Acids 30:1-15, 2006). Here, we focus on more recent findings regarding: (1) the identification of enzymes associated with high-M(r) cysteine S-conjugate β-lyases in the cytosolic and mitochondrial fractions of rat liver and kidney; (2) the mechanism of syncatalytic inactivation of rat liver mitochondrial aspartate aminotransferase by the nephrotoxic β-lyase substrate S-(1,1,2,2-tetrafluoroethyl)-L-cysteine (the cysteine S-conjugate of tetrafluoroethylene); (3) toxicant channeling of reactive fragments from the active site of mitochondrial aspartate aminotransferase to susceptible proteins in the mitochondria; (4) the involvement of cysteine S-conjugate β-lyases in the metabolism/bioactivation of drugs and natural products; and (5) the role of cysteine S-conjugate β-lyases in the metabolism of selenocysteine Se-conjugates. This review emphasizes the fact that the cysteine S-conjugate β-lyases are biologically more important than hitherto appreciated.

  10. Influence of heat on biological activity and concentration of oleocanthal--a natural anti-inflammatory agent in virgin olive oil.

    Science.gov (United States)

    Cicerale, Sara; Conlan, Xavier A; Barnett, Neil W; Sinclair, Andrew J; Keast, Russell S J

    2009-02-25

    The olive oil phenolic oleocanthal is a natural nonsteroidal anti-inflammatory compound that irritates the oral pharynx in a dose-dependent manner. It has been proposed that the biological activity of oleocanthal is partially responsible for the beneficial health effects of the Mediterranean diet. Virgin olive oil containing oleocanthal is often added as an ingredient in a number of cooked dishes, and therefore it is of great importance to understand how best to preserve the putative health-promoting benefits of this compound, as olive oil phenolics are subject to degradation upon heating in general. One extra virgin olive oil containing 53.9 mg/kg oleocanthal was heated at various temperatures (100, 170, and 240 degrees C) for set time periods (0, 1, 5, 20, 60, and 90 min). Oleocanthal concentrations were quantified using HPLC, and its biological activity was determined with a taste bioassay measuring the intensity of throat irritation. Results demonstrated that oleocanthal was heat stable compared with other olive oil phenolics, with a maximum loss of 16% as determined by HPLC analysis. However, there was a significant decrease of up to 31% (p taste bioassay. Although there was minimal degradation of oleocanthal concentration, there was a significant decrease in the biological activity of oleocanthal upon extended heating time, indicating a possible loss of the putative health -benefiting properties of oleocanthal. Alternatively, the difference in the concentration and biological activity of oleocanthal after heat treatment could be a result of an oleocanthal antagonist forming, decreasing or masking the biological activity of oleocanthal.

  11. Use of eugenol-lean clove extract as a flavoring agent and natural antioxidant in mayonnaise: product characterization and storage study.

    Science.gov (United States)

    Chatterjee, Dipan; Bhattacharjee, Paramita

    2015-08-01

    Eugenol-lean fraction (98 % lower eugenol content than eugenol-rich fraction) having appreciable phytochemical properties was selectively isolated from clove buds (Syzygium aromaticum Linn) using supercritical carbon dioxide extraction at 40 °C and pressure of 25 MPa with static and dynamic time of 120 and 30 min respectively using ground clove powder which was previously subjected to steam distillation. The extract was used as a flavor ingredient (replacing mustard in classical formulation) and also as a source of natural antioxidant in formulating a new mayonnaise product to improve its nutraceutical value and shelf-life. This product was found to be comparable to the mustard formulated sample (experimental control) organoleptically. The sample did not have typical pungency of clove and had improved physical properties such as increased color tonality with higher chroma values, lower thermal and non-thermal creaming, homogenous and compact microstructure and higher consistency index vis-à-vis the control and standard market samples, even at the end of the storage period of 6 months. Mayonnaise formulated with eugenol-lean clove extract had significantly higher antioxidant activity (IC50 = 10.85 mg/mL), phenolic content (1.89 mg gallic acid equivalent/g mayonnaise) and reducing power (11.29 mg BHT equivalent/g mayonnaise) than mustard-formulated mayonnaise and the market sample. While, the antioxidant activity and phytochemical properties tend to decrease after 30 days for the reference market sample and after 90 days for the experimental control sample, the mayonnaise formulated with eugenol-lean clove extract was found to be stable beyond 6 months.

  12. Antibiotic Agents

    Science.gov (United States)

    ... agents. A recent survey reported that 76% of liquid soaps from 10 states in the US contained triclosan ... regulated depends upon its intended use and its effectiveness. The US Food and Drug Administration (FDA) regulates antibacterial soaps and antibacterial substances that will either be used ...

  13. Radioprotective Agents

    Science.gov (United States)

    1982-01-01

    claimed to be effective are gallic acid derivatives, eg, sodium gallate 12053-21-61 (295-297) and propyl gallate 1121-79-91 (298). p...inhibition of a-adrenergic receptors can be achieved through the use of the antiradiation agents 2-(5-aminopentylamino)ethanephos- phorothioic acid ...tissue was ap- preciated immediately as a potential medical set, and they were put to use en- thusiastically. Early workers did notice an erythematous

  14. Writing Nature

    Directory of Open Access Journals (Sweden)

    Kristin Asdal

    2014-06-01

    Full Text Available This special issue of the Nordic Journal of Science and Technology Studies is interested in how nature, in different versions and forms, is invited into our studies, analyses, and stories. How is it that we “write nature”? How is it that we provide space for, and actually describe the actors, agents, or surroundings, in our stories and analyses? The articles in the issue each deal with different understandings of both the practices of writing and the introduction of various natures into these. In this introduction to the issue the editors engage with actor-network theory as a material semiotic resource for writing nature. We propose to foreground actor-network theory as a writing tool, at the expense of actor-network theory as a distinct vocabulary. In doing this and pointing out the semiotic origins to material-semiotics we also want to problematize a clear-cut material approach to writing nature.

  15. Trading Agents

    CERN Document Server

    Wellman, Michael

    2011-01-01

    Automated trading in electronic markets is one of the most common and consequential applications of autonomous software agents. Design of effective trading strategies requires thorough understanding of how market mechanisms operate, and appreciation of strategic issues that commonly manifest in trading scenarios. Drawing on research in auction theory and artificial intelligence, this book presents core principles of strategic reasoning that apply to market situations. The author illustrates trading strategy choices through examples of concrete market environments, such as eBay, as well as abst

  16. Actinopyga lecanora Hydrolysates as Natural Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Raheleh Ghanbari

    2012-12-01

    Full Text Available Actinopyga lecanora, a type of sea cucumber commonly known as stone fish with relatively high protein content, was explored as raw material for bioactive peptides production. Six proteolytic enzymes, namely alcalase, papain, pepsin, trypsin, bromelain and flavourzyme were used to hydrolyze A. lecanora at different times and their respective degrees of hydrolysis (DH were calculated. Subsequently, antibacterial activity of the A. lecanora hydrolysates, against some common pathogenic Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus and Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas sp. were evaluated. Papain hydrolysis showed the highest DH value (89.44%, followed by alcalase hydrolysis (83.35%. Bromelain hydrolysate after one and seven hours of hydrolysis exhibited the highest antibacterial activities against Pseudomonas sp., P. aeruginosa and E. coli at 51.85%, 30.07% and 30.45%, respectively compared to the other hydrolysates. Protein hydrolysate generated by papain after 8 h hydrolysis showed maximum antibacterial activity against S. aureus at 20.19%. The potent hydrolysates were further fractionated using RP-HPLC and antibacterial activity of the collected fractions from each hydrolysate were evaluated, wherein among them only three fractions from the bromelain hydrolysates exhibited inhibitory activities against Pseudomonas sp., P. aeruginosa and E. coli at 24%, 25.5% and 27.1%, respectively and one fraction of papain hydrolysate showed antibacterial activity of 33.1% against S. aureus. The evaluation of the relationship between DH and antibacterial activities of papain and bromelain hydrolysates revealed a meaningful correlation of four and six order functions.

  17. 抗老化剂改善竹粉/聚丙烯发泡复合材料的自然老化性能%Anti-aging agents improving natural weathering properties of bamboo powder/polypropylene foamed composites

    Institute of Scientific and Technical Information of China (English)

    周吓星; 陈礼辉

    2015-01-01

    production, the natural weathering performance of bamboo powder/polypropylene (PP) foamed composites was researched. The composites containing 33% bamboo flour, 1% modified AC (azodicarbonamide) foaming agent and different anti-aging agents were prepared by the injection molding. The composites were exposed to outdoor natural weathering from October 2012 to October 2013 in Fuzhou (26°08′N, 119°18′E), the southeast of China. The effects of natural weathering on the composites’ color, flexural creep behavior and rheological behavior were investigated. Meanwhile, the effects of the antioxidant B225 and anti-ultraviolet agent UV770 on the composites’ weathering performance were also studied. The B225 is a complex antioxidant agent using Tetra-[methylene-β-(3, 5-di-tert-butyl-4-hydroxyphenyl)-propionate] methan and Tns-(2, 4-di-tert-butyl)-phosphite, with a ratio of 1:1. The UV770 is bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate. The results showed that both the B225 and the UV770 could slow down the color fading and improve the color stability during weathering. After weathering for 12 months, the color change reduced from22.8 for the composites without adding antioxidant to 14.2, 17.6 and 16.8 for the composites contained with 0.6% B225, 0.6% UV770, 0.3% B225 and 0.3% UV770, respectively. The B225 has more positive effect on color stability of the composites than UV770. According to authors’ prior research, the influence of natural weathering on the composites’ color was similar with the artificial accelerated weathering. The color change caused by the natural weathering for 12 months was equal to that by accelerated weathering of xenon-arc radiation with water spray for 0.4 months, and also was similar to that by the accelerated cycling of water immersion followed by freeze-thaw cycle at the temperature of -40-60℃for 22 times. Due to the combined effect of the creep and long-term weathering, particularly at 75% stress level, the creep strain increased, and the

  18. Research ZTC1+1 Natural Clarifying Agent for Removal of Extraneous Materials in Paeonia lactiflora Medicine%ZTC1+1天然澄清剂在赤芍药材除杂工艺中应用研究

    Institute of Scientific and Technical Information of China (English)

    刘卫红; 吴冬梅; 张娜娜; 张振巍

    2011-01-01

    目的:研究ZTC1+1天然澄清剂用于赤芍药材除杂方法.方法:采用单因素实验设计方法对ZTC1+1天然澄清剂的影响因素进行考察,并得出最佳因素组合与醇沉方法进行对比.结果:ZTC1+1天然澄清剂的除杂效果要比醇沉好.结论:采用ZTC1+1天然澄清剂对中药水提液除杂是一个较好的方法,该方法有方便、经济、除杂效果好、安全等优点.%Objective: Research the method of ZTC1 + 1 natural clarifying agent for the removal of extraneous materials in Paeonia Lactiflora medicine. Method:Single factor design method was used for investigating ZTC1 + 1 natural clarifying agent of the relevant factors and the optimum combination of factors and alcohol precipitation methods were compared. Result: The effect of ZTC1 + 1 natural clarifying agent of impurity was better than alcohol precipitation. Conclusion: Natural clarifying agents with ZTC1 + 1 for aqueous extract of Chinese medicine is a better way to impurity. The method is convenient, economical and safe with the effect of imparity removal.

  19. A dialogue agent for navigation support in virtual reality

    NARCIS (Netherlands)

    Luin, van J.; Akker, op den H.J.A.; Nijholt, A.; Jacko, J.; Sears, A.

    2001-01-01

    We describe our work on designing a natural language accessible navigation agent for a virtual reality (VR) environment. The agent is part of an agent framework, which means that it can communicate with other agents. Its navigation task consists of guiding the visitors in the environment and to answ

  20. Computational Environment of Software Agents

    Directory of Open Access Journals (Sweden)

    Martin Tomášek

    2008-05-01

    Full Text Available Presented process calculus for software agent communication and mobility canbe used to express distributed computational environment and mobile code applications ingeneral. Agents are abstraction of the functional part of the system architecture and theyare modeled as process terms. Agent actions model interactions within the distributedenvironment: local/remote communication and mobility. Places are abstraction of thesingle computational environment where the agents are evaluated and where interactionstake place. Distributed environment is modeled as a parallel composition of places whereeach place is evolving asynchronously. Operational semantics defines rules to describebehavior within the distributed environment and provides a guideline for implementations.Via a series of examples we show that mobile code applications can be naturally modeled.

  1. MOBILE AGENT: EMERGING TECHNOLOGY

    OpenAIRE

    RAJGURU P. V. DR. DESHMUKH S. D

    2011-01-01

    Mobile agent technology has been promoted as an emerging technology that makes it much easier to design, implement, and maintain distributed systems, introduction to basic concepts of mobile agents like agent mobility, agent types and places and agent communication. Then benefits of the usage of mobile agents are summarized and illustrated by selected applications. The next section lists requirements and desirable properties for mobile agent languages and systems. We study the main features, ...

  2. Riot Control Agents

    Science.gov (United States)

    ... Submit What's this? Submit Button Facts About Riot Control Agents Interim document Recommend on Facebook Tweet Share Compartir FACT SHEET What riot control agents are Riot control agents (sometimes referred to ...

  3. Interacting agents in finance

    NARCIS (Netherlands)

    C. Hommes

    2008-01-01

    Interacting agents in finance represent a behavioural, agent-based approach in which financial markets are viewed as complex adaptive systems consisting of many boundedly rational agents interacting through simple heterogeneous investment strategies, constantly adapting their behaviour in response t

  4. Interacting agents in finance

    NARCIS (Netherlands)

    Hommes, C.; Durlauf, S.N.; Blume, L.E.

    2008-01-01

    Interacting agents in finance represent a behavioural, agent-based approach in which financial markets are viewed as complex adaptive systems consisting of many boundedly rational agents interacting through simple heterogeneous investment strategies, constantly adapting their behaviour in response

  5. Natural gas; Gas Natural

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Carlos A.; Moraes, Claudia C.D. [Eletricidade de Sao Paulo S.A. (ELETROPAULO), Sao Paulo, SP (Brazil); Fonseca, Carlos H.F. [Centrais Eletricas de Santa Catarina S.A., Florianopolis, SC (Brazil); Silva, Clecio Fabricio da; Alves, Ricardo P. [Companhia Paranaense de Energia (COPEL), Curitiba, PR (Brazil); Sposito, Edivaldo Soares; Hulle, Lutero [Espirito Santo Centrais Eletricas S.A. (ESCELSA), Vitoria, ES (Brazil); S. Martins, Icaro da [Centrais Eletricas do Norte do Brasil S.A. (ELETRONORTE), Belem, PA (Brazil); Vilhena, Joao Luiz S. de [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil); Fagundes, Zaluar Aquino [Companhia Estadual de Energia Eletrica do Estado do Rio Grande do Sul, Porto Alegre, RS (Brazil)

    1996-12-31

    An increase in the consumption of natural gas in Brazil is an expected fact in what concerns energetic planning. This work presents the existing situation in what concerns natural gas utilization in the main world economies, as well as an analysis of the participation of this fuel among the energy final consumption per sources. The Brazilian consumption of natural gas is also analysed as well as the international agreement between Brazil and Bolivia for natural gas commercialization. Some legal, institutional and political aspects related to natural gas commercialization are also discussed. Finally, several benefits to be brought by the utilization of natural gas are presented 10 refs., 3 tabs.

  6. Pyranone natural products as inspirations for catalytic reaction discovery and development.

    Science.gov (United States)

    McDonald, Benjamin R; Scheidt, Karl A

    2015-04-21

    bifunctional hydrogen bonding/Brønstead base catalyst was ultimately found to enable this transformation in analogous manner to the biosynthesis via the enzyme chalcone isomerase. Employing thiourea catalysts derived from the pseudoenantiomeric quinine and quinidine, alkylidene β-ketoesters can be isomerized to 3-carboxy flavanones and decarboxylated in a single pot operation to stereodivergently provide highly enantioenriched flavanones in excellent yield. This method was applied to the synthesis of the abyssinone family of natural products, as well as the rotenoid, deguelin. An analogous method to isomerize chalcones was developed and applied to the synthesis of isosilybin A. In both of these related endeavors, the need for novel enabling methodologies toward the efficient creation of targeted molecular complexity drove the discovery, development and deployment of these stereoselective catalytic transformations.

  7. Biological warfare agents.

    Science.gov (United States)

    Pohanka, Miroslav; Kuca, Kamil

    2010-01-01

    Biological warfare agents are a group of pathogens and toxins of biological origin that can be potentially misused for military or criminal purposes. The present review attempts to summarize necessary knowledge about biological warfare agents. The historical aspects, examples of applications of these agents such as anthrax letters, biological weapons impact, a summary of biological warfare agents and epidemiology of infections are described. The last section tries to estimate future trends in research on biological warfare agents.

  8. Extension agents and conflict narratives

    DEFF Research Database (Denmark)

    Bond, Jennifer Lauren

    2016-01-01

    conflict. Originality: This work contributes to a growing body of literature interested in the role of extension agents in conflict management. By applying Q methodology, this work has shown that while extension agents are involved in conflict management, their perceptions of these conflicts are subjective......Purpose: This work investigated the narratives of development extensionists in relation to natural resource conflict, in order to understand the competing discourses surrounding the wicked problems of natural resource management in Laikipia County, Kenya. Methodology: Q methodology was used...... to elicit the conflict narratives present among extension professionals. A concourse of 221 statements were devised from interviews and group discussions with key informants and a final sample of 49 statements was used for the sorting. Thirteen Q-sorts were undertaken with among rural extension...

  9. Infectious Agents and Cancer

    African Journals Online (AJOL)

    these agents on subsequent risk of cancer. There are currently ... tween genetic and environmental factors (that include infectious agents) .... opment of gastric adenocarcinoma and gastric lym- phoma. However .... Lung cancer i. Skin cancers ...

  10. Animal Capture Agents

    Science.gov (United States)

    1990-01-01

    agents and delivery systems reviewed . Questionnaires were sent to 137 Air Force bases to obtain information about the chemical agents and delivery systems...used by animal control personnel. A literature review included chemical agents, delivery methods, toxicity information and emergency procedures from...34-like agent. Users should familiarize themselves with catatonia in general and particularly that its successful use as an immobilizer doesn’t necessarily

  11. Reasoning about emotional agents

    NARCIS (Netherlands)

    Meyer, J.-J.

    2008-01-01

    In this paper we discuss the role of emotions in artificial agent design, and the use of logic in reasoning about the emotional or affective states an agent can reside in. We do so by extending the KARO framework for reasoning about rational agents appropriately. In particular we formalize in this f

  12. Intelligent Agents: A Primer.

    Science.gov (United States)

    Yu, Edmund; Feldman, Susan

    1999-01-01

    Provides an in-depth introduction to the various technologies that are bringing intelligent agents into the forefront of information technology, explaining how such agents work, the standards involved, and how agent-based applications can be developed. (Author/AEF)

  13. Users, Bystanders and Agents

    DEFF Research Database (Denmark)

    Krummheuer, Antonia Lina

    2015-01-01

    Human-agent interaction (HAI), especially in the field of embodied conversational agents (ECA), is mainly construed as dyadic communication between a human user and a virtual agent. This is despite the fact that many application scenarios for future ECAs involve the presence of others. This paper...

  14. Culturally Aware Agent Communication

    DEFF Research Database (Denmark)

    Rehm, Matthias; Nakano, Yukiko; Koda, Tomoko

    2012-01-01

    Agent based interaction in the form of Embodied Conversational Agents (ECAs) has matured over the last decade and agents have become more and more sophisticated in terms of their verbal and nonverbal behavior like facial expressions or gestures. Having such “natural” communication channels...

  15. Conversational Agents and the Construction of Humorous Acts

    OpenAIRE

    Nijholt, Anton; Nishida, Toyoaki

    2007-01-01

    In this chapter we discuss the generation of humorous acts by embodied agents. It is observed that in future interfaces that are meant to allow natural interaction, embodied agents can play useful roles. Humor plays an important role in human-human interaction and therefore it is useful to investigate how it should become part of the internal modeling of an embodied agent, along with intelligence and emotion modeling. Employment of embodied agents will also give rise to expectations concernin...

  16. THE INTEGRATED AGENT IN MULTI-AGENT SYSTEMS

    OpenAIRE

    Maleković, Mirko; Čubrilo, Mirko

    2000-01-01

    [n this paper, we characterize the integrated agent in multi-agent systems. The following result is proved: if a multi-agent system is reflexive (symmetric, transitive, Euclidean) then the integrated agent of the multi-agent system is reflexive (symmetric, transitive, Euclidean), respectively. We also prove that the analogous result does not hold for multi-agent system's serial ness. A knowledge relationship between the integrated agent and agents in a multiagent system is presented.

  17. Mobile agent security using proxy-agents and trusted domains

    OpenAIRE

    Mitrovic, Nikola; Arronategui Arribalzaga, Unai

    2009-01-01

    Commercial or wide-network deployment of Mobile Agent Systems is not possible without satisfying security architecture. In this paper we propose architecture for secure Mobile Agent Systems, using Trusted Domains and Proxy agents. Existing approaches are based on security services at the level of an agent system, library or specific objects. Our concept uses proxy agents to enable transparent security services both to security-aware mobile agents and legacy agents. Per-agent and domain-level...

  18. Agent Architectures for Compliance

    Science.gov (United States)

    Burgemeestre, Brigitte; Hulstijn, Joris; Tan, Yao-Hua

    A Normative Multi-Agent System consists of autonomous agents who must comply with social norms. Different kinds of norms make different assumptions about the cognitive architecture of the agents. For example, a principle-based norm assumes that agents can reflect upon the consequences of their actions; a rule-based formulation only assumes that agents can avoid violations. In this paper we present several cognitive agent architectures for self-monitoring and compliance. We show how different assumptions about the cognitive architecture lead to different information needs when assessing compliance. The approach is validated with a case study of horizontal monitoring, an approach to corporate tax auditing recently introduced by the Dutch Customs and Tax Authority.

  19. Adaptive auctioneer agents

    OpenAIRE

    2011-01-01

    M.Sc. This dissertation investigates how auctioneer agents can maximise the revenue of an auction. Auctions are an effective solution to agent negotiation because of their simplicity. They are therefore the most widely used approach to agent negotiation. A review of auction theory proves that auction revenue is influenced by factors such as the auction format and the auction parameters. The optimal auction format and parameters are dependent on the bidders and the auction environment. A st...

  20. Culturally Aware Agent Communication

    DEFF Research Database (Denmark)

    Rehm, Matthias; Nakano, Yukiko; Koda, Tomoko

    2012-01-01

    Agent based interaction in the form of Embodied Conversational Agents (ECAs) has matured over the last decade and agents have become more and more sophisticated in terms of their verbal and nonverbal behavior like facial expressions or gestures. Having such “natural” communication channels...... available for expressing not only task-relevant but also socially and psychologically relevant information makes it necessary to take influences into account that are not readily implemented like emotions or cultural heuristics. These influences have a huge impact on the success of an interaction...... the expression of multimodal behavior in agents....

  1. Decontamination Data - Blister Agents

    Data.gov (United States)

    U.S. Environmental Protection Agency — Decontamination efficacy data for blister agents on various building materials using various decontamination solutions. This dataset is associated with the following...

  2. Social Robots as Persuasive Agents

    DEFF Research Database (Denmark)

    Vlachos, Evgenios; Schärfe, Henrik

    2014-01-01

    Robots are more and more used in a social context, and in this paper we try to formulate a research agenda concerning ethical issues around social HRI in order to be prepared for future scenarios where robots may be a naturally integrated part of human society. We outline different paradigms...... to describe the role of social robots in communication processes with humans, and connect HRI with the topic of persuasive technology in health care, to critically reflect the potential benefits of using social robots as persuasive agents....

  3. Change Agent Survival Guide

    Science.gov (United States)

    Dunbar, Folwell L.

    2011-01-01

    Consulting is a rough racket. Only a tarantula hair above IRS agents, meter maids and used car sales people, the profession is a prickly burr for slings and arrows. Throw in education, focus on dysfunctional schools and call oneself a "change agent," and this bad rap all but disappears. Unfortunately, though, consulting/coaching/mentoring in…

  4. Agents in domestic environments

    NARCIS (Netherlands)

    Moergestel, Leo van; Langerak, Wouter; Meerstra, Glenn; Nieuwenburg, Niels van; Pape, Franc; Telgen, Daniël; Puik, Erik; Meyer, John-Jules

    2013-01-01

    Athor supplied : "This paper describes an agent-based architecture for domotics. This architecture is based on requirements about expandability and hardware independence. The heart of the system is a multi-agent system. This system is distributed over several platforms to open the possibility to ti

  5. Agents in domestic environments

    NARCIS (Netherlands)

    Glenn Meerstra; Wouter Langerak; Leo van Moergestel; Niels van Nieuwenburg; John-Jules Meyer; Ing. Erik Puik; Franc Pape; Daniël Telgen

    2013-01-01

    Athor supplied : "This paper describes an agent-based architecture for domotics. This architecture is based on requirements about expandability and hardware independence. The heart of the system is a multi-agent system. This system is distributed over several platforms to open the possibility to

  6. Chemotherapy and Dietary Phytochemical Agents

    Directory of Open Access Journals (Sweden)

    Katrin Sak

    2012-01-01

    Full Text Available Chemotherapy has been used for cancer treatment already for almost 70 years by targeting the proliferation potential and metastasising ability of tumour cells. Despite the progress made in the development of potent chemotherapy drugs, their toxicity to normal tissues and adverse side effects in multiple organ systems as well as drug resistance have remained the major obstacles for the successful clinical use. Cytotoxic agents decrease considerably the quality of life of cancer patients manifesting as acute complaints and impacting the life of survivors also for years after the treatment. Toxicity often limits the usefulness of anticancer agents being also the reason why many patients discontinue the treatment. The nutritional approach may be the means of helping to raise cancer therapy to a new level of success as supplementing or supporting the body with natural phytochemicals cannot only reduce adverse side effects but improve also the effectiveness of chemotherapeutics. Various plant-derived compounds improve the efficiency of cytotoxic agents, decrease their resistance, lower and alleviate toxic side effects, reduce the risk of tumour lysis syndrome, and detoxify the body of chemotherapeutics. The personalised approach using various phytochemicals provides thus a new dimension to the standard cancer therapy for improving its outcome in a complex and complementary way.

  7. Asimovian Adaptive Agents

    CERN Document Server

    Gordon, D F

    2011-01-01

    The goal of this research is to develop agents that are adaptive and predictable and timely. At first blush, these three requirements seem contradictory. For example, adaptation risks introducing undesirable side effects, thereby making agents' behavior less predictable. Furthermore, although formal verification can assist in ensuring behavioral predictability, it is known to be time-consuming. Our solution to the challenge of satisfying all three requirements is the following. Agents have finite-state automaton plans, which are adapted online via evolutionary learning (perturbation) operators. To ensure that critical behavioral constraints are always satisfied, agents' plans are first formally verified. They are then reverified after every adaptation. If reverification concludes that constraints are violated, the plans are repaired. The main objective of this paper is to improve the efficiency of reverification after learning, so that agents have a sufficiently rapid response time. We present two solutions: ...

  8. Animal venoms as antimicrobial agents.

    Science.gov (United States)

    Perumal Samy, Ramar; Stiles, Bradley G; Franco, Octavio L; Sethi, Gautam; Lim, Lina H K

    2017-06-15

    Hospitals are breeding grounds for many life-threatening bacteria worldwide. Clinically associated gram-positive bacteria such as Staphylococcus aureus/methicillin-resistant S. aureus and many others increase the risk of severe mortality and morbidity. The failure of antibiotics to kill various pathogens due to bacterial resistance highlights the urgent need to develop novel, potent, and less toxic agents from natural sources against various infectious agents. Currently, several promising classes of natural molecules from snake (terrestrial and sea), scorpion, spider, honey bee and wasp venoms hold promise as rich sources of chemotherapeutics against infectious pathogens. Interestingly, snake venom-derived synthetic peptide/snake cathelicidin not only has potent antimicrobial and wound-repair activity but is highly stable and safe. Such molecules are promising candidates for novel venom-based drugs against S. aureus infections. The structure of animal venom proteins/peptides (cysteine rich) consists of hydrophobic α-helices or β-sheets that produce lethal pores and membrane-damaging effects on bacteria. All these antimicrobial peptides are under early experimental or pre-clinical stages of development. It is therefore important to employ novel tools for the design and the development of new antibiotics from the untapped animal venoms of snake, scorpion, and spider for treating resistant pathogens. To date, snail venom toxins have shown little antibiotic potency against human pathogens. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Bipartite flocking for multi-agent systems

    Science.gov (United States)

    Fan, Ming-Can; Zhang, Hai-Tao; Wang, Miaomiao

    2014-09-01

    This paper addresses the bipartite flock control problem where a multi-agent system splits into two clusters upon internal or external excitations. Using structurally balanced signed graph theory, LaSalle's invariance principle and Barbalat's Lemma, we prove that the proposed algorithm guarantees a bipartite flocking behavior. In each of the two disjoint clusters, all individuals move with the same direction. Meanwhile, every pair of agents in different clusters moves with opposite directions. Moreover, all agents in the two separated clusters approach a common velocity magnitude, and collision avoidance among all agents is ensured as well. Finally, the proposed bipartite flock control method is examined by numerical simulations. The bipartite flocking motion addressed by this paper has its references in both natural collective motions and human group behaviors such as predator-prey and panic escaping scenarios.

  10. Autonomic Management for Multi-agent Systems

    CERN Document Server

    Salih, Nadir K; Viju, PG K; Mohamed, Abdelmotalib A

    2011-01-01

    Autonomic computing is a computing system that can manage itself by self-configuration, self-healing, self-optimizing and self-protection. Researchers have been emphasizing the strong role that multi agent systems can play progressively towards the design and implementation of complex autonomic systems. The important of autonomic computing is to create computing systems capable of managing themselves to a far greater extent than they do today. With the nature of autonomy, reactivity, sociality and pro-activity, software agents are promising to make autonomic computing system a reality. This paper mixed multi-agent system with autonomic feature that completely hides its complexity from users/services. Mentioned Java Application Development Framework as platform example of this environment, could applied to web services as front end to users. With multi agent support it also provides adaptability, intelligence, collaboration, goal oriented interactions, flexibility, mobility and persistence in software systems

  11. Progress on natural polyphenols as anti-invasive and anti-metastasis agents%天然多酚衍生物抗肿瘤侵袭与转移研究进展

    Institute of Scientific and Technical Information of China (English)

    姜永莉; 刘兆鹏

    2011-01-01

    The ability to invade and metastasize is a hallmark of malignant tumors, and metastasis poses the biggest problem to cancer treatment and is the main cause of death of cancer patients. Tumor invasion and metastasis are complex, multistep biochemical process, which involve cell detachment, invasion, migration,intravasation and circulation, implantation, angiogenesis and proliferation. Therefore, how to prevent tumor metastasis are the biggest challenge in cancer chemotherapy. In recent years, many natural products are found to have anti-invasion and anti-metastasis activities. In this paper, the natural polyphenolic compounds are classified according to their chemical structures including diarylheptanoids, stibenoids, flavonoids, phenylpropanoids, cannabinoids and naphthoquinones, and their anti-invasion and anti-metastasis activities and biological targets are introduced.%肿瘤侵袭与转移是恶性肿瘤的基本特征,是临床肿瘤患者死亡的最主要因为.肿瘤侵袭与转移过程涉及细胞的脱落、浸润、迁移运行、着床、新生血管生成等过程,作用机制非常复杂,因此,防止肿瘤转移一直是肿瘤治疗的难题.近年来研究发现,许多天然产物具有抗肿瘤侵袭和转移能力,该文对天然多酚类化合物的抗肿瘤侵袭和转移作用的研究进展进行综述.

  12. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

    Augustijn, Ellen-Wien; Doldersum, Tom; Useya, Juliana; Augustijn, Denie

    2016-01-01

    This paper introduces a spatially explicit agent-based simulation model for micro-scale cholera diffusion. The model simulates both an environmental reservoir of naturally occurring V. cholerae bacteria and hyperinfectious V. cholerae. Objective of the research is to test if runoff from open refuse

  13. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

    Augustijn, Ellen-Wien; Doldersum, Tom; Useya, Juliana; Augustijn, Denie

    2016-01-01

    This paper introduces a spatially explicit agent-based simulation model for micro-scale cholera diffusion. The model simulates both an environmental reservoir of naturally occurring V.cholerae bacteria and hyperinfectious V. cholerae. Objective of the research is to test if runoff from open refuse d

  14. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

    Augustijn-Beckers, Petronella; Doldersum, Tom; Useya, Juliana; Augustijn, Dionysius C.M.

    2016-01-01

    This paper introduces a spatially explicit agent-based simulation model for micro-scale cholera diffusion. The model simulates both an environmental reservoir of naturally occurring V.cholerae bacteria and hyperinfectious V. cholerae. Objective of the research is to test if runoff from open refuse

  15. Disappearing computers, social actors and embodied agents.

    NARCIS (Netherlands)

    Nijholt, A.; Kunii, T.L.; Hock Soon, S.; Sourin, A.

    2003-01-01

    Presently, there are user interfaces that allow multimodal interactions. Many existing research and prototype systems introduced embodied agents, assuming that they allow a more natural conversation or dialogue between user and computer. Here we will first take a look at how in general people react

  16. Biological warfare agents

    Directory of Open Access Journals (Sweden)

    Duraipandian Thavaselvam

    2010-01-01

    Full Text Available The recent bioterrorist attacks using anthrax spores have emphasized the need to detect and decontaminate critical facilities in the shortest possible time. There has been a remarkable progress in the detection, protection and decontamination of biological warfare agents as many instrumentation platforms and detection methodologies are developed and commissioned. Even then the threat of biological warfare agents and their use in bioterrorist attacks still remain a leading cause of global concern. Furthermore in the past decade there have been threats due to the emerging new diseases and also the re-emergence of old diseases and development of antimicrobial resistance and spread to new geographical regions. The preparedness against these agents need complete knowledge about the disease, better research and training facilities, diagnostic facilities and improved public health system. This review on the biological warfare agents will provide information on the biological warfare agents, their mode of transmission and spread and also the detection systems available to detect them. In addition the current information on the availability of commercially available and developing technologies against biological warfare agents has also been discussed. The risk that arise due to the use of these agents in warfare or bioterrorism related scenario can be mitigated with the availability of improved detection technologies.

  17. Social Dynamics in Web Page through Inter-Agent Interaction

    Science.gov (United States)

    Takeuchi, Yugo; Katagiri, Yasuhiro

    Social persuasion abounds in human-human interactions. Attitudes and behaviors of people are invariably influenced by the attitudes and behaviors of other people as well as our social roles/relationships toward them. In the pedagogic scene, the relationship between teacher and learner produces one of the most typical interactions, in which the teacher makes the learner spontaneously study what he/she teaches. This study is an attempt to elucidate the nature and effectiveness of social persuasion in human-computer interaction environments. We focus on the social dynamics of multi-party interactions that involve both human-agent and inter-agent interactions. An experiment is conducted in a virtual web-instruction setting employing two types of agents: conductor agents who accompany and guide each learner throughout his/her learning sessions, and domain-expert agents who provide explanations and instructions for each stage of the instructional materials. In this experiment, subjects are assigned two experimental conditions: the authorized condition, in which an agent respectfully interacts with another agent, and the non-authorized condition, in which an agent carelessly interacts with another agent. The results indicate performance improvements in the authorized condition of inter-agent interactions. An analysis is given from the perspective of the transfer of authority from inter-agent to human-agent interactions based on social conformity. We argue for pedagogic advantages of social dynamics created by multiple animated character agents.

  18. 10th KES Conference on Agent and Multi-Agent Systems : Technologies and Applications

    CERN Document Server

    Chen-Burger, Yun-Heh; Howlett, Robert; Jain, Lakhmi

    2016-01-01

    The modern economy is driven by technologies and knowledge. Digital technologies can free, shift and multiply choices, often intruding on the space of other industries, by providing new ways of conducting business operations and creating values for customers and companies. The topics covered in this volume include software agents, multi-agent systems, agent modelling, mobile and cloud computing, big data analysis, business intelligence, artificial intelligence, social systems, computer embedded systems and nature inspired manufacturing, etc. that contribute to the modern Digital Economy. This volume highlights new trends and challenges in agent, new digital and knowledge economy research and includes 28 papers classified in the following specific topics: business process management, agent-based modeling and simulation, anthropic-oriented computing, learning paradigms, business informatics and gaming, digital economy, and advances in networked virtual enterprises. Published papers were selected for presentatio...

  19. Agent-Based Optimization

    CERN Document Server

    Jędrzejowicz, Piotr; Kacprzyk, Janusz

    2013-01-01

    This volume presents a collection of original research works by leading specialists focusing on novel and promising approaches in which the multi-agent system paradigm is used to support, enhance or replace traditional approaches to solving difficult optimization problems. The editors have invited several well-known specialists to present their solutions, tools, and models falling under the common denominator of the agent-based optimization. The book consists of eight chapters covering examples of application of the multi-agent paradigm and respective customized tools to solve  difficult optimization problems arising in different areas such as machine learning, scheduling, transportation and, more generally, distributed and cooperative problem solving.

  20. Health care agents

    Science.gov (United States)

    ... make decisions during a stressful time. Your agent's duty is to see that your wishes are followed. ... Philadelphia, PA: Elsevier; 2016:chap 5. Zorowitz RA. Ethics. In: Ham RJ Jr, Sloane PD, Warshaw GA, ...

  1. Agent Standards Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation of the work herein proposed is the development of standards for software autonomous agents. These standards are essential to achieve software...

  2. Steroidal neuromuscular blocking agents

    NARCIS (Netherlands)

    Wierda, JMKH; Mori, K; Ohmura, A; Toyooka, H; Hatano, Y; Shingu, K; Fukuda, K

    1998-01-01

    Since 1964 approximately 20 steroidal neuromuscular blocking agents have been evaluated clinically. Pancuronium, a bisquaternary compound designed on the drawingboard, was the first steroidal relaxant introduced into clinical practice worldwide in the 1970's. Although a major improvement, pancuroniu

  3. Effect of water table variations and input of natural organic matter on the cycles of C and N, and mobility of As, Zn and Cu from a soil impacted by the burning of chemical warfare agents: A mesocosm study.

    Science.gov (United States)

    Thouin, Hugues; Battaglia-Brunet, Fabienne; Gautret, Pascale; Le Forestier, Lydie; Breeze, Dominique; Séby, Fabienne; Norini, Marie-Paule; Dupraz, Sebastien

    2017-10-01

    A mesocosm study was conducted to assess the impact of water saturation episodes and of the input of bioavailable organic matter on the biogeochemical cycles of C and N, and on the behavior of metal(loid)s in a soil highly contaminated by the destruction of arsenical shells. An instrumented mesocosm was filled with contaminated soil taken from the "Place-à-Gaz" site. Four cycles of dry and wet periods of about one month were simulated for 276days. After two dry/wet cycles, organic litter sampled on the site was added above the topsoil. The nitrogen cycle was the most impacted by the wet/dry cycles, as evidenced by a denitrification microbial process in the saturated level. The concentrations of the two most mobile pollutants, Zn and As, in the soil water and in the mesocosm leachate were, respectively, in the 0.3-1.6mM and 20-110μM ranges. After 8months of experiment, about 83g·m(-3) of Zn and 3.5g·m(-3) of As were leached from the soil. These important quantities represent cycles had no major effect on Zn mobility. However, soil saturation induced the immobilization of As by trapping As V but enhanced As III mobility. These phenomena were amplified by the presence of bioavailable organic matter. The study showed that the natural deposition of forest organic litter allowed a part of the soil's biological function to be restored but did not immobilize all the Zn and As, and even contributed to transport of As III to the surrounding environment. The main hazard of this type of site, contaminated by organo-arsenic chemical weapons, is the constitution of a stock of As that may leach into the surrounding environment for several hundred years. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. [Decontamination of chemical and biological warfare agents].

    Science.gov (United States)

    Seto, Yasuo

    2009-01-01

    Chemical and biological warfare agents (CBWA's) are diverse in nature; volatile acute low-molecular-weight toxic compounds, chemical warfare agents (CWA's, gaseous choking and blood agents, volatile nerve gases and blister agents, nonvolatile vomit agents and lacrymators), biological toxins (nonvolatile low-molecular-weight toxins, proteinous toxins) and microbes (bacteria, viruses, rickettsiae). In the consequence management against chemical and biological terrorism, speedy decontamination of victims, facilities and equipment is required for the minimization of the damage. In the present situation, washing victims and contaminated materials with large volumes of water is the basic way, and additionally hypochlorite salt solution is used for decomposition of CWA's. However, it still remains unsolved how to dispose large volumes of waste water, and the decontamination reagents have serious limitation of high toxicity, despoiling nature against the environments, long finishing time and non-durability in effective decontamination. Namely, the existing decontamination system is not effective, nonspecifically affecting the surrounding non-target materials. Therefore, it is the urgent matter to build up the usable decontamination system surpassing the present technologies. The symposiast presents the on-going joint project of research and development of the novel decontamination system against CBWA's, in the purpose of realizing nontoxic, fast, specific, effective and economical terrorism on-site decontamination. The projects consists of (1) establishment of the decontamination evaluation methods and verification of the existing technologies and adaptation of bacterial organophosphorus hydrolase, (2) development of adsorptive elimination technologies using molecular recognition tools, and (4) development of deactivation technologies using photocatalysis.

  5. Conversational Agents and the Construction of Humorous Acts

    NARCIS (Netherlands)

    Nijholt, Anton; Nishida, Toyoaki

    2007-01-01

    In this chapter we discuss the generation of humorous acts by embodied agents. It is observed that in future interfaces that are meant to allow natural interaction, embodied agents can play useful roles. Humor plays an important role in human-human interaction and therefore it is useful to investiga

  6. Surface Treatment of Building Materials with Water Repellent Agents

    OpenAIRE

    Wittman, F.H.; Siemes, T.A.J.M.; Verhoef, L.G.W.

    1995-01-01

    Water repellent agents have been applied to proteet building materials and structural elements for thousands ofyears. Initially, natural products, such as oils and fats were used exclusively. More recently, synthetic organic compounds are being developed for special applications.

  7. Leader Election for Anonymous Asynchronous Agents in Arbitrary Networks

    CERN Document Server

    Dereniowski, Dariusz

    2012-01-01

    We study the problem of leader election among mobile agents operating in an arbitrary network modeled as an undirected graph. Nodes of the network are unlabeled and all agents are identical. Hence the only way to elect a leader among agents is by exploiting asymmetries in their initial positions in the graph. Agents do not know the graph or their positions in it, hence they must gain this knowledge by navigating in the graph and share it with other agents to accomplish leader election. This can be done using meetings of agents, which is difficult because of their asynchronous nature: an adversary has total control over the speed of agents. When can a leader be elected in this adversarial scenario and how to do it? We give a complete answer to this question by characterizing all initial configurations for which leader election is possible and by constructing an algorithm that accomplishes leader election for all configurations for which this can be done.

  8. Natural product HTP screening for antibacterial (E.coli 0157:H7) and anti-inflammatory agents in (LPS from E. coli O111:B4) activated macrophages and microglial cells; focus on sepsis.

    Science.gov (United States)

    Mazzio, Elizabeth A; Li, Nan; Bauer, David; Mendonca, Patricia; Taka, Equar; Darb, Mohammed; Thomas, Leeshawn; Williams, Henry; Soliman, Karam F A

    2016-11-15

    Acute systemic inflammatory response syndrome arising from infection can lead to multiple organ failure and death, with greater susceptibility occurring in immunocompromised individuals. Moreover, sub-acute chronic inflammation is a contributor to the pathology of diverse degenerative diseases (Parkinson's disease, Alzheimer's disease and arthritis). Given the known limitations in Western medicine to treat a broad range of inflammatory related illness as well as the emergence of antibiotic resistance, there is a renewed interest in complementary and alternative medicines (CAMs) to achieve these means. A high throughput (HTP) screening of >1400 commonly sold natural products (bulk herbs, cooking spices, teas, leaves, supplement components, nutraceutical food components, fruit and vegetables, rinds, seeds, polyphenolics etc.) was conducted to elucidate anti-inflammatory substances in lipopolysaccharide (LPS) (E. coli serotype O111:B4) monocytes: RAW 264.7 macrophages [peripheral], BV-2 microglia [brain]) relative to hydrocortisone, dexamethasone and L-N6-(1Iminoethyl)lysine (L-NIL). HTP evaluation was also carried out for lethal kill curves against E.coli 0157:H7 1x10(6) CFU/mL relative to penicillin. Validation studies were performed to assess cytokine profiling using antibody arrays. Findings were corroborated by independent ELISAs and NO2-/iNOS expression quantified using the Griess Reagent and immunocytochemistry, respectively. For robust screening, we developed an in-vitro efficacy paradigm to ensure anti-inflammatory parameters were observed independent of cytotoxicity. This caution was taken given that many plants exert tumoricidal and anti-inflammatory effects at close range through similar signaling pathways, which could lead to false positives. The data show that activated BV-2 microglia cells (+ LPS 1μg/ml) release >10-fold greater IL-6, MIP1/2, RANTES and nitric oxide (NO2-), where RAW 264.7 macrophages (+ LPS 1μg/ml) produced > 10-fold rise in sTNFR2

  9. The use of a pH-dependent and Non pH-dependent Natural Hydrophobic Biopolymer (Landolphia owariensis latex as Capsule Coating Agents in in vitro Controlled Release of Metronidazole for Possible Colon Targeted Delivery

    Directory of Open Access Journals (Sweden)

    N C Obitte

    2010-03-01

    : Landolphia owariensis latex is an ignored part of the climber tree. It can be cultivated and tapped to commercial scale as in rubber. There is presently a patent based on colon targeted technology which adopted  capsule coating approach. The dip method of coating employed in this article is a common technology in capsule manufacture; therefore coating of the capsules with our natural biopolymer and Eudragit L-100 is not going to be tasking. This double hydrophobic coating technique prolongs drug release enough to convey the capsule to the colon with greatest quantity of the drug intact. This makes colon drug targeting an attractive drug delivery approach for the rare oral delivery of protein/biotech products, etc. Insulin is commonly presented as an injectable with its attendant problem of patient compliance and frequent puncturing of the skin. With capsule filling machines having coating accessories attached to them large scale manufacture can be embarked upon.

  10. Intelligent agents for e-commerce applications

    Science.gov (United States)

    Vuppala, Krishna

    1999-12-01

    This thesis focuses on development of intelligent agent solutions for e-commerce applications. E-Commerce has several complexities like: lack of information about the players, learning the nature of one's business partners/competitors, finding the right business partner to do business with, using the right strategy to get best profit out of the negotiations etc. The agent models developed can be used in any agent solution for e-commerce. Concepts and techniques from Game Theory and Artificial Intelligence are used. The developed models have several advantages over the existing ones as: the models assume the non-availability of information about other players in the market, the models of players get updated over the time as and when new information comes about the players, the negotiation model incorporates the patience levels of the players and expectations from other players in the market. Power industry has been chosen as the application area for the demonstration of the capabilities and usage of the developed agent models. Two e-commerce scenarios where sellers and buyers can go through the power exchanges to bid in auctions, or make bilateral deals outside of the exchange are addressed. In the first scenario agent helps market participants in coordinating strategies with other participants, bidding in auctions by analyzing and understanding the behavior of other participants. In the second scenario, called "Power Traders Assistant" agent helps power trader, who buys and sells power through bilateral negotiations, in negotiating deals with his customers.

  11. Biological Warfare Agents

    Directory of Open Access Journals (Sweden)

    Dev Vrat Kamboj

    2006-10-01

    Full Text Available There is a long historic record of use of biological warfare (BW agents by warring countriesagainst their enemies. However, the frequency of their use has increased since the beginningof the twentieth century. World war I witnessed the use of anthrax agent against human beingsand animals by Germans, followed by large-scale field trials by Japanese against war prisonersand Chinese population during world war II. Ironically, research and development in biologicalwarfare agents increased tremendously after the Geneva Protocol, signed in 1925, because ofits drawbacks which were overcome by Biological and Toxin Weapons Convention (BTWC in1972. Biological warfare programme took back seat after the 1972 convention but biologicalagents regained their importance after the bioterrorist attacks of anthrax powder in 2001. In thelight of these attacks, many of which turned out to be hoax, general awareness is required aboutbiological warfare agents that can be used against them. This review has been written highlightingimportant biological warfare agents, diseases caused by them, possible therapies and otherprotection measures.

  12. Honey - A Novel Antidiabetic Agent

    Directory of Open Access Journals (Sweden)

    Omotayo O. Erejuwa, Siti A. Sulaiman, Mohd S. Ab Wahab

    2012-01-01

    Full Text Available Diabetes mellitus remains a burden worldwide in spite of the availability of numerous antidiabetic drugs. Honey is a natural substance produced by bees from nectar. Several evidence-based health benefits have been ascribed to honey in the recent years. In this review article, we highlight findings which demonstrate the beneficial or potential effects of honey in the gastrointestinal tract (GIT, on the gut microbiota, in the liver, in the pancreas and how these effects could improve glycemic control and metabolic derangements. In healthy subjects or patients with impaired glucose tolerance or diabetes mellitus, various studies revealed that honey reduced blood glucose or was more tolerable than most common sugars or sweeteners. Pre-clinical studies provided more convincing evidence in support of honey as a potential antidiabetic agent than clinical studies did. The not-too-impressive clinical data could mainly be attributed to poor study designs or due to the fact that the clinical studies were preliminary. Based on the key constituents of honey, the possible mechanisms of action of antidiabetic effect of honey are proposed. The paper also highlights the potential impacts and future perspectives on the use of honey as an antidiabetic agent. It makes recommendations for further clinical studies on the potential antidiabetic effect of honey. This review provides insight on the potential use of honey, especially as a complementary agent, in the management of diabetes mellitus. Hence, it is very important to have well-designed, randomized controlled clinical trials that investigate the reproducibility (or otherwise of these experimental data in diabetic human subjects.

  13. Agent Oriented Programming进展%Advances in Agent Oriented Programming

    Institute of Scientific and Technical Information of China (English)

    王一川; 石纯一

    2002-01-01

    Agent-oriented programming (AOP) is a framework to develop agents, and it aims to link the gap betweentheory and practical in agent research. The core of an AOP framework is its language and semantics. In this paper,we propose the necessary properties which agents should have, and then give a summary and analysis about differentAOP languages based on these properties.

  14. Teaching Tourism Change Agents

    DEFF Research Database (Denmark)

    Stilling Blichfeldt, Bodil; Kvistgaard, Hans-Peter; Hird, John

    2017-01-01

    This article discuss es know ledge, competencies and skills Master’s students should obtain during their academic studies and particularly, the differences between teaching about a topic and teaching to do. This is ex emplified by experiential learning theory and the case of a change management...... course that is part of a Tourism Master’s program, where a major challenge is not only to teach students about change and change agents, but to teach them how change feels and ho w to become change agents. The c hange management course contains an experiment inspired by experiential teaching literature...... and methods. The experiment seeks to make students not only hear/learn about change agency and management, but to make them feel cha nge, hereby enabling them to develop the skills and competencies necessary for them to take on the role as change agent s and thus enable them to play key role s in implementing...

  15. Triazole: A Promising Antitubercular Agent.

    Science.gov (United States)

    Keri, Rangappa S; Patil, Siddappa A; Budagumpi, Srinivasa; Nagaraja, Bhari Mallanna

    2015-10-01

    Tuberculosis is a contagious disease with comparatively high mortality worldwide. The statistics shows that around three million people throughout the world die annually from tuberculosis and there are around eight million new cases each year, of which developing countries showed major share. Therefore, the discovery and development of effective antituberculosis drugs with novel mechanism of action have become an insistent task for infectious diseases research programs. The literature reveals that, heterocyclic moieties have drawn attention of the chemists, pharmacologists, microbiologists, and other researchers owing to its indomitable biological potential as anti-infective agents. Among heterocyclic compounds, triazole (1,2,3-triazole/1,2,4-triazole) nucleus is one of the most important and well-known heterocycles, which is a common and integral feature of a variety of natural products and medicinal agents. Triazole core is considered as a privileged structure in medicinal chemistry and is widely used as 'parental' compounds to synthesize molecules with medical benefits, especially with infection-related activities. In the present review, we have collated published reports on this versatile core to provide an insight so that its complete therapeutic potential can be utilized for the treatment of tuberculosis. This review also explores triazole as a potential targeted core moiety against tuberculosis and various research ongoing worldwide. It is hoped that this review will be helpful for new thoughts in the quest for rational designs of more active and less toxic triazole-based antituberculosis drugs.

  16. Agents unleashed a public domain look at agent technology

    CERN Document Server

    Wayner, Peter

    1995-01-01

    Agents Unleashed: A Public Domain Look at Agent Technology covers details of building a secure agent realm. The book discusses the technology for creating seamlessly integrated networks that allow programs to move from machine to machine without leaving a trail of havoc; as well as the technical details of how an agent will move through the network, prove its identity, and execute its code without endangering the host. The text also describes the organization of the host's work processing an agent; error messages, bad agent expulsion, and errors in XLISP-agents; and the simulators of errors, f

  17. Displaying Nature

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Beijing Museum of Natural History is located in Chongwen District, close to the Temple of Heaven and Tianqiao Theater. It was founded in 1951 and formally named Beijing Museum of Natural History in 1962.

  18. Software Agent Techniques in Design

    DEFF Research Database (Denmark)

    Hartvig, Susanne C

    1998-01-01

    This paper briefly presents studies of software agent techniques and outline aspects of these which can be applied in design agents in integrated civil engineering design environments.......This paper briefly presents studies of software agent techniques and outline aspects of these which can be applied in design agents in integrated civil engineering design environments....

  19. Agent Persuasion Mechanism of Acquaintance

    Science.gov (United States)

    Jinghua, Wu; Wenguang, Lu; Hailiang, Meng

    Agent persuasion can improve negotiation efficiency in dynamic environment based on its initiative and autonomy, and etc., which is being affected much more by acquaintance. Classification of acquaintance on agent persuasion is illustrated, and the agent persuasion model of acquaintance is also illustrated. Then the concept of agent persuasion degree of acquaintance is given. Finally, relative interactive mechanism is elaborated.

  20. Learning Sequences of Actions in Collectives of Autonomous Agents

    Science.gov (United States)

    Turner, Kagan; Agogino, Adrian K.; Wolpert, David H.; Clancy, Daniel (Technical Monitor)

    2001-01-01

    In this paper we focus on the problem of designing a collective of autonomous agents that individually learn sequences of actions such that the resultant sequence of joint actions achieves a predetermined global objective. We are particularly interested in instances of this problem where centralized control is either impossible or impractical. For single agent systems in similar domains, machine learning methods (e.g., reinforcement learners) have been successfully used. However, applying such solutions directly to multi-agent systems often proves problematic, as agents may work at cross-purposes, or have difficulty in evaluating their contribution to achievement of the global objective, or both. Accordingly, the crucial design step in multiagent systems centers on determining the private objectives of each agent so that as the agents strive for those objectives, the system reaches a good global solution. In this work we consider a version of this problem involving multiple autonomous agents in a grid world. We use concepts from collective intelligence to design goals for the agents that are 'aligned' with the global goal, and are 'learnable' in that agents can readily see how their behavior affects their utility. We show that reinforcement learning agents using those goals outperform both 'natural' extensions of single agent algorithms and global reinforcement, learning solutions based on 'team games'.

  1. Exploring the use of natural antimicrobial agents and pulsed electric fields to control spoilage bacteria during a beer production process Exploración del uso de agentes antimicrobianos naturales y de campos eléctricos pulsantes para el control de bacterias contaminantes durante el proceso de elaboración de cerveza

    Directory of Open Access Journals (Sweden)

    M. A. Galvagno

    2007-09-01

    Full Text Available Different natural antimicrobials affected viability of bacterial contaminants isolated at critical steps during a beer production process. In the presence of 1 mg/ml chitosan and 0.3 mg/ml hops, the viability of Escherichia coli in an all malt barley extract wort could be reduced to 0.7 and 0.1% respectively after 2 hour- incubation at 4 °C. The addition of 0.0002 mg/ml nisin, 0.1 mg/ml chitosan or 0.3 mg/ml hops, selectively inhibited growth of Pediococcus sp. in more than 10,000 times with respect to brewing yeast in a mixed culture. In the presence of 0.1mg ml chitosan in beer, no viable cells of the thermoresistant strain Bacillus megaterium were detected. Nisin, chitosan and hops increased microbiological stability during storage of a local commercial beer inoculated with Lactobacillus plantarum or Pediococcus sp. isolated from wort. Pulsed Electric Field (PEF (8 kV/cm, 3 pulses application enhanced antibacterial activity of nisin and hops but not that of chitosan. The results herein obtained suggest that the use of these antimicrobial compounds in isolation or in combination with PEF would be effective to control bacterial contamination during beer production and storage.Diferentes antimicrobianos naturales disminuyeron la viabilidad de bacterias contaminantes aisladas en etapas críticas del proceso de producción de cerveza. En un extracto de malta, el agregado de 1 mg/ml de quitosano y de 0,3 mg ml de lúpulo permitió reducir la viabilidad de Escherichia coli a 0,7 y 0,1%, respectivamente, al cabo de 2 horas de incubación a 4 °C. El agregado de 0,0002 mg/ml de nisina, 0,1 mg/ml de quitosano o de 0,3 mg/ml de lúpulo inhibió selectivamente (10.000 veces más el crecimiento de Pediococcus sp. respecto de la levadura de cerveza en un cultivo mixto. El agregado de 0,1 mg/ml de quitosano permitió disminuir la viabilidad de una cepa bacteriana termorresistente, Bacillus megaterium, hasta niveles no detectables. Por otra parte, el

  2. inventory management, VMI, software agents, MDV model

    Directory of Open Access Journals (Sweden)

    Waldemar Wieczerzycki

    2012-03-01

    Full Text Available Background: As it is well know, the implementation of instruments of logistics management is only possible with the use of the latest information technology. So-called agent technology is one of the most promising solutions in this area. Its essence consists in an entirely new way of software distribution on the computer network platform, in which computer exchange among themselves not only data, but also software modules, called just agents. The first aim is to propose the alternative method of the implementation of the concept of the inventory management by the supplier with the use of intelligent software agents, which are able not only to transfer the information but also to make the autonomous decisions based on the privileges given to them. The second aim of this research was to propose a new model of a software agent, which will be both of a high mobility and a high intelligence. Methods: After a brief discussion of the nature of agent technology, the most important benefits of using it to build platforms to support business are given. Then the original model of polymorphic software agent, called Multi-Dimensionally Versioned Software Agent (MDV is presented, which is oriented on the specificity of IT applications in business. MDV agent is polymorphic, which allows the transmission through the network only the most relevant parts of its code, and only when necessary. Consequently, the network nodes exchange small amounts of software code, which ensures high mobility of software agents, and thus highly efficient operation of IT platforms built on the proposed model. Next, the adaptation of MDV software agents to implementation of well-known logistics management instrument - VMI (Vendor Managed Inventory is illustrated. Results: The key benefits of this approach are identified, among which one can distinguish: reduced costs, higher flexibility and efficiency, new functionality - especially addressed to business negotiation, full automation

  3. Programming Agents with Emotions

    NARCIS (Netherlands)

    Dastani, Mehdi; Floor, Chr.; Meyer, John-Jules Charles

    2014-01-01

    In this paper we show how a cognitive agent programming language can be endowed with ways to program emotions. In particular we show how the programming language 2APL can be augmented so that it can work together with the computational emotion model ALMA to deal with appraisal, emotion/mood generati

  4. SECOND BUYING AGENT

    CERN Multimedia

    SPL - SERVICES ACHATS

    2000-01-01

    Last year the buying agent LOGITRADE started operations on the CERN site, processing purchasing requests for well-defined families of products up to a certain value. It was planned from the outset that a second buying agent would be brought in to handle the remaining product families. So, according to that plan, the company CHARLES KENDALL will be commencing operations at CERN on 8 May 2000 in Building 73, 1st floor, offices 31 and 35 (phone and fax numbers to be announced).Each buying agent will have its own specific list of product families and will handle purchasing requests up to 10'000 CHF.Whenever possible they will provide the requested supplies at a price (including the cost of their own services) which must be equivalent to or lower than the price mentioned on the purchasing request, changing the supplier if necessary. If a lower price cannot be obtained, agents will provide the necessary administrative support free of charge.To ensure that all orders are processed in the best possible conditions, us...

  5. Remote Agent Experiment

    Science.gov (United States)

    Benard, Doug; Dorais, Gregory A.; Gamble, Ed; Kanefsky, Bob; Kurien, James; Millar, William; Muscettola, Nicola; Nayak, Pandu; Rouquette, Nicolas; Rajan, Kanna; Norvig, Peter (Technical Monitor)

    2000-01-01

    Remote Agent (RA) is a model-based, reusable artificial intelligence (At) software system that enables goal-based spacecraft commanding and robust fault recovery. RA was flight validated during an experiment on board of DS1 between May 17th and May 21th, 1999.

  6. Agent-Based Cloud Computing

    OpenAIRE

    Sim, Kwang Mong

    2012-01-01

    Agent-based cloud computing is concerned with the design and development of software agents for bolstering cloud service\\ud discovery, service negotiation, and service composition. The significance of this work is introducing an agent-based paradigm for\\ud constructing software tools and testbeds for cloud resource management. The novel contributions of this work include: 1) developing\\ud Cloudle: an agent-based search engine for cloud service discovery, 2) showing that agent-based negotiatio...

  7. Novel anticancer agents from plant sources

    Institute of Scientific and Technical Information of China (English)

    Shah Unnati; Shah Ripal; Acharya Sanjeev; Acharya Niyati

    2013-01-01

    Plants remain an important source of new drugs,new drug leads and new chemical entities.Plant based drug discovery resulted mainly in the development of anticancer and anti-infectious agents,and continues to contribute to the new leads in clinical trials.Natural product drugs play a dominant role in pharmaceutical care.Several plant-derived compounds are currently successfully employed in cancer treatment.There are many classes of plant-derived cytotoxic natural products studied for further improvement and development of drugs.New anticancer drugs derived from research on plant antitumor agents will be continuously discovered.The basic aim of this review is to explore the potential of newly discovered anticancer compounds from medicinal plants,as a lead for anticancer drug development.It will be helpful to explore the medicinal value of plants and for new drug discovery from them for the researchers and scientists around the globe.

  8. Measure Landscape Diversity with Logical Scout Agents

    Science.gov (United States)

    Wirth, E.; Szabó, G.; Czinkóczky, A.

    2016-06-01

    The Common Agricultural Policy reform of the EU focuses on three long-term objectives: viable food production, sustainable management of natural resources and climate action with balanced territorial development. To achieve these goals, the EU farming and subsidizing policies (EEA, 2014) support landscape heterogeneity and diversity. Current paper introduces an agent-based method to calculate the potential of landscape diversity. The method tries to catch the nature of heterogeneity using logic and modelling as opposed to the traditional statistical reasoning. The outlined Random Walk Scouting algorithm registers the land cover crossings of the scout agents to a Monte Carlo integral. The potential is proportional with the composition and the configuration (spatial character) of the landscape. Based on the measured points a potential map is derived to give an objective and quantitative basis to the stakeholders (policy makers, farmers).

  9. NATURAL HEALING AGENT: GARLIC, AN APPROACH TO HEALTHY LIFE

    Directory of Open Access Journals (Sweden)

    Nagori B.P.

    2010-12-01

    Full Text Available We have grown up in the era of so-called wonder drugs. Garlic is one such drug which is grown globally. China is by far the largest producer of garlic, with approximately 10.5 million tonnes (23 billion pounds annually, accounting for over 77% of world output. This leaves 16% of global garlic production in countries that each produces less than 2% of global output. The purpose of this study is to highlight new applications of cultivated as well as wild garlic in medicine. Areas of beneficial activity include anti-AIDS, anti-cancer and anti-cardiovascular disease and anti-infectious properties, amongst others. Garlic is uniquely the richest dietary source of many otherwise rare healthful sulphur compounds, plus organic selenium and germanium besides other essential nutrients and active health-promoting phytochemicals. Various forms of garlic are available, the most effective being fresh, powdered, distilled and especially aged garlic, which later lacks the irritant effect of fresh garlic, yet possesses equal or greater bio-active range and potency.Since many years cultivated garlic (Allium sativum has served the medicinal purpose. As demand of garlic is continuously increasing due to its valuable features, other garlic species are screened for potential benefits of cultivated garlic with less side effects. Wild garlic grows abundantly in many areas of country. It is a plant that seldom needs to be cultivated. They have a distinct garlic flavor, though are milder than garlic cloves. Hence extensive study is required for both cultivated and wild species so as to establish them as a future wonder drug.

  10. NATURAL HEALING AGENT: GARLIC, AN APPROACH TO HEALTHY LIFE

    OpenAIRE

    2010-01-01

    We have grown up in the era of so-called wonder drugs. Garlic is one such drug which is grown globally. China is by far the largest producer of garlic, with approximately 10.5 million tonnes (23 billion pounds) annually, accounting for over 77% of world output. This leaves 16% of global garlic production in countries that each produces less than 2% of global output. The purpose of this study is to highlight new applications of cultivated as well as wild garlic in medicine. Areas of beneficial...

  11. Relaxin as a natural agent for vascular health

    Directory of Open Access Journals (Sweden)

    Daniele Bani

    2008-06-01

    Full Text Available Daniele BaniDepartment of Anatomy, Histology and Forensic Medicine, Sect. Histology, University of Florence, ItalyAbstract: Hypertension, atherothrombosis, myocardial infarction, stroke, peripheral vascular disease, and renal failure are the main manifestations of cardiovascular disease (CVD, the leading cause of death and disability in developed countries. Continuing insight into the pathophysiology of CVD can allow identification of effective therapeutic strategies to reduce the occurrence of death and/or severe disabilities. In this context, a healthy endothelium is deemed crucial to proper functioning and maintenance of anatomical integrity of the vascular system in many organs. Of note, epidemiologic studies indicate that the incidence of CVD in women is very low until menopause and increases sharply thereafter. The loss of protection against CVD in post-menopausal women has been chiefly attributed to ovarian steroid deficiency. However, besides steroids, the ovary also produces the peptide hormone relaxin (RLX, which provides potent vasoactive effects which render it the most likely candidate as the elusive physiological shield against CVD in fertile women. In particular, RLX has a specific relaxant effect on peripheral and coronary vasculature, exerted by the stimulation of endogenous nitric oxide (NO generation by cells of the vascular wall, and can induce angiogenesis. Moreover, RLX inhibits the activation of inflammatory leukocytes and platelets, which play a key role in CVD. Experimental studies performed in vascular and blood cell in vitro and in animal models of vascular dysfunction, as well as pioneer clinical observations, have provided evidence that RLX can prevent and/or improve CVD, thus offering background to clinical trials aimed at exploring the broad therapeutic potential of human recombinant RLX as a new cardiovascular drug.Keywords: relaxin, blood vessels, endothelial cells, vascular smooth muscle, nitric oxide, cardiovascular disease

  12. Attenuation of cytotoxic natural product DNA intercalating agents by caffeine.

    Science.gov (United States)

    Hill, Gabrielle M; Moriarity, Debra M; Setzer, William N

    2011-01-01

    Many anti-tumor drugs function by intercalating into DNA. The xanthine alkaloid caffeine can also intercalate into DNA as well as form π-π molecular complexes with other planar alkaloids and anti-tumor drugs. The presence of caffeine could interfere with the intercalating anti-tumor drug by forming π-π molecular complexes with the drug, thereby blocking the planar aromatic drugs from intercalating into the DNA and ultimately lowering the toxicity of the drug to the cancer cells. The cytotoxic activities of several known DNA intercalators (berberine, camptothecin, chelerythrine, doxorubicin, ellipticine, and sanguinarine) on MCF-7 breast cancer cells, both with and without caffeine present (200 μg/mL) were determined. Significant attenuation of the cytotoxicities by caffeine was found. Computational molecular modeling studies involving the intercalating anti-tumor drugs with caffeine were also carried out using density functional theory (DFT) and the recently developed M06 functional. Relatively strong π-π interaction energies between caffeine and the intercalators were found, suggesting an "interceptor" role of caffeine protecting the DNA from intercalation.

  13. Naturally Inspired Molecules as Multifunctional Agents for Alzheimer's Disease Treatment.

    Science.gov (United States)

    Rampa, Angela; Tarozzi, Andrea; Mancini, Francesca; Pruccoli, Letizia; Di Martino, Rita Maria Concetta; Gobbi, Silvia; Bisi, Alessandra; De Simone, Angela; Palomba, Francesco; Zaccheroni, Nelsi; Belluti, Federica

    2016-05-16

    Alzheimer's disease (AD) has been defined as a multi-factorial disorder resulting from a complex array of networked cellular and molecular mechanisms. In particular, elevated levels of Aβ protein and its aggregation products in the presence of metal ions proved to be highly neurotoxic and therapeutic strategies aimed at preventing Aβ generation and oxidative stress may represent an effective approach for AD treatment. A recent paradigm for the treatment of complex diseases such as AD suggests the employment of multifunctional compounds, single chemical entities capable of simultaneously modulating different targets involved in the pathology. In this paper, the "pharmacophores combination" strategy was applied, connecting the main scaffold of the BACE-1 ligand 1 to that of the chalcone 2, as metal chelating pharmacophore, to obtain a small library of compounds. Conjugate 5 emerged as the most interesting derivative, proving to inhibit BACE-1 with low-micromolar potency, and showing neuroprotective effects. In particular, 5 proved to be able to protect from metal-associated oxidative stress by hampering intracellular Cu(2+)-induced ROS formation without any direct neurotoxic effect.

  14. A review on promising natural agents effective on hyperlipidemia.

    Science.gov (United States)

    Bahmani, Mahmoud; Mirhoseini, Mahmoud; Shirzad, Hedayatollah; Sedighi, Mehrnoosh; Shahinfard, Nejmeh; Rafieian-Kopaei, Mahmoud

    2015-07-01

    Hyperlipidemia is a prevalent disease and a major component of the metabolic syndrome resulting from various factors. This disease increases morbidity and mortality when combined with other prevalent diseases such as diabetes mellitus, hypertension, and cardiovascular diseases. The side effects of the current lipid-lowering drugs have increased the tendency to move toward traditional and alternative treatments. Epidemiological observations indicate that using alternative treatments, consumption of medicinal plants, diet, and consumption of fruits have had satisfactory results on the effects of hyperlipidemia in many societies. It should be noted that in majority of societies, even developed countries, the tendency toward eating lipid-lowering medicinal plants has increased extensively. Using these plants especially when common remedies cannot control the disease is significant. Although consumption of medicinal plants by hyperlipidemic patients may show improvement in disease state, drug interaction and side effects may cause complications in disease control. Therefore, in this review, apart from introducing some of the reliable plants effective in inhibition and decrease of hyperlipidemia, the possibility of their intoxication and drug interaction is also presented.

  15. NATURAL HEALING AGENT: GARLIC, AN APPROACH TO HEALTHY LIFE

    OpenAIRE

    Nagori B.P.; Solanki Renu; Sharma Neha

    2010-01-01

    We have grown up in the era of so-called wonder drugs. Garlic is one such drug which is grown globally. China is by far the largest producer of garlic, with approximately 10.5 million tonnes (23 billion pounds) annually, accounting for over 77% of world output. This leaves 16% of global garlic production in countries that each produces less than 2% of global output. The purpose of this study is to highlight new applications of cultivated as well as wild garlic in medicine. Areas of beneficial...

  16. Electrospun biodegradable polymers loaded with bactericide agents

    Directory of Open Access Journals (Sweden)

    Ramaz Katsarava

    2016-03-01

    Full Text Available Development of materials with an antimicrobial activity is fundamental for different sectors, including medicine and health care, water and air treatment, and food packaging. Electrospinning is a versatile and economic technique that allows the incorporation of different natural, industrial, and clinical agents into a wide variety of polymers and blends in the form of micro/nanofibers. Furthermore, the technique is versatile since different constructs (e.g. those derived from single electrospinning, co-electrospinning, coaxial electrospinning, and miniemulsion electrospinning can be obtained to influence the ability to load agents with different characteristics and stability and to modify the release behaviour. Furthermore, antimicrobial agents can be loaded during the electrospinning process or by a subsequent coating process. In order to the mitigate burst release effect, it is possible to encapsulate the selected drug into inorganic nanotubes and nanoparticles, as well as in organic cyclodextrine polysaccharides. In the same way, processes that involve covalent linkage of bactericide agents during surface treatment of electrospun samples may also be considered. The present review is focused on more recent works concerning the electrospinning of antimicrobial polymers. These include chitosan and common biodegradable polymers with activity caused by the specific load of agents such as metal and metal oxide particles, quaternary ammonium compounds, hydantoin compounds, antibiotics, common organic bactericides, and bacteriophages.

  17. PLURALIZING NATURE

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    Denmark is widely recognised for its democratic approach to planning and the idea of planning for the common good. This interest in the common good and common values seems also to be reflected in the way which nature restoration is planned and managed – one common nature directed by the public...... authorities. But nature restoration is far from being a neural undertaking. Just like any other type of heritage production it can be the source of dissonance – ‘our’ nature is not necessary ‘their’ nature. Often this dissonance is managed in ways, which are not particular sensitive to site......-specificity. As exemplified by the Skjern River Restoration Project (1999-2003), one interpretation of the landscape sometimes suppresses other valid interpretations neglecting its diverse history. However, evidence from Switzerland suggests that planning for the common good, in the case of nature restoration, does...

  18. Nature seconded

    OpenAIRE

    Gough, Tim

    2002-01-01

    Heidegger�s remark that the banks of the river (representing nature in its supposedly pure state) only become apparent because of the presence of the bridge (representing the artificial in its supposed opposition to that nature) will lead this presentation to a discussion of whether or not the idea of �nature� as prior to architecture remains unequivocally valid. If nature/the site - that which claims to come before the artificial/architecture - only appears as a result of the presence ...

  19. [Pharmacology of inotropic agents].

    Science.gov (United States)

    Pastelín Hernández, Gustavo

    2002-01-01

    High-risk patients, during anesthesia and after surgery present changes in pharmacokinetics (biotransformation reactions, renal clearance, drug interactions, etc.) modifying the usefulness of most drugs, cardiac inotropics included. This group of substances is formed by adrenergic agents, phospodiesterase inhibitors and digitalis compounds. Adrenergic agents are the catecholamines, adrenaline (A), noradrenaline (NA) and dopamine (D), plus dopaminergic agonists as dobutamine and pirbuterol. Phosphodiesterase inhibitors, as amrinone and milrinone, produce their inotropic action by preserving cyclic adenosine monophosphate (AMPc) from its intracellular catabolism. Recent studies on the utility of digitalis compounds demonstrated the valuable applicability of digoxin in chronic and acute heart failure. Another group of substances whose mechanism of action differs from that of the inotropics, offers future utility in high risk patients, they include: inhibitors of nitric oxide sintases, natriuretic atrial peptide inhibitors, Q-10 coenzyme, endothelin antagonists, and anti-tumoral necrosis factor.

  20. Announcements to Attentive Agents

    DEFF Research Database (Denmark)

    Bolander, Thomas; van Ditmarsch, Hans; Herzig, Andreas;

    2016-01-01

    In public announcement logic it is assumed that all agents pay attention to the announcement. Weaker observational conditions can be modelled in action model logic. In this work, we propose a version of public announcement logic wherein it is encoded in the states of the epistemic model which...... agents pay attention to the announcement. This logic is called attention-based announcement logic. We give an axiomatization of the logic and prove that complexity of satisfiability is the same as that of public announcement logic, and therefore lower than that of action model logic. An attention......-based announcement can also be described as an action model. We extend our logic by integrating attention change. Finally, we add the notion of common belief to the language, we exploit this to formalize the concept of joint attention, that has been widely discussed in the philosophical and cognitive science...

  1. [The antiretroviral agent Fullevir].

    Science.gov (United States)

    Nosik, D N; Lialina, I K; Kalnina, L B; Lobach, O A; Chataeva, M S; Rasnetsov, L D

    2009-01-01

    The antiretroviral properties of Fullevir (sodium salt of fullerenepolyhydropolyaminocaproic acid) manufactured by IntelFarm Co.) were studied in the human cell culture infected with human immunodeficiency virus (HIV). The agent was ascertained to be able to protect the cell from the cytopathic action of HIV. The 90% effective concentration (EF90) was 5 microg/ml. The 50% average toxic concentration was 400 microg/ml. Testing of different (preventive and therapeutic) Fullevir dosage regimens has shown that the drug is effective when used both an hour before and an hour after infection and when administered simultaneously with cell infection. The longer contact time for the agent with the cells increased the degree of antiviral defense. Co-administration of Fullevir and the HIV reverse transcriptase inhibitor Retrovir (azidothymidine) showed a synergistic antiretroviral effect. Thus, Fullevir may be regarded as a new promising antiretroviral drug for the treatment of HIV infection.

  2. Pharmacology of antiplatelet agents.

    Science.gov (United States)

    Kalra, Kiran; Franzese, Christopher J; Gesheff, Martin G; Lev, Eli I; Pandya, Shachi; Bliden, Kevin P; Tantry, Udaya S; Gurbel, Paul A

    2013-12-01

    Pharmacotherapies with agents that inhibit platelet function have proven to be effective in the treatment of acute coronary syndromes, and in the prevention of complications during and after percutaneous coronary intervention. Because of multiple synergetic pathways of platelet activation and their close interplay with coagulation, current treatment strategies are based not only on platelet inhibition, but also on the attenuation of procoagulant activity, inhibition of thrombin generation, and enhancement of clot dissolution. Current strategies can be broadly categorized as anticoagulants, antiplatelet agents, and fibrinolytics. This review focuses on the pharmacology of current antiplatelet therapy primarily targeting the inhibition of the enzyme cyclooxygenase 1, the P2Y12 receptor, the glycoprotein IIb/IIIa receptor, and protease-activated receptor 1.

  3. Sunscreening Agents: A Review

    OpenAIRE

    Latha, M. S.; Martis, Jacintha; Shobha, V; Sham Shinde, Rutuja; Bangera, Sudhakar; Krishnankutty, Binny; Bellary, Shantala; Varughese, Sunoj; Rao, Prabhakar; B R Naveen Kumar

    2013-01-01

    The increasing incidence of skin cancers and photodamaging effects caused by ultraviolet radiation has increased the use of sunscreening agents, which have shown beneficial effects in reducing the symptoms and reoccurrence of these problems. Many sunscreen compounds are in use, but their safety and efficacy are still in question. Efficacy is measured through indices, such as sun protection factor, persistent pigment darkening protection factor, and COLIPA guidelines. The United States Food an...

  4. Intelligent Agent Integration Technology

    Science.gov (United States)

    1998-04-01

    The DARPA knowledge sharing effort: Progress report. In B. Nebel , C. Rich, and W. Swartout, editors, Principles of Knowledge Representation and...and Automation, pages 2,785-2,788. IEEE CS Press. [18] Carl Hewitt. Offices are open systems. Communications of the ACM, 4(3):271-287, July 1986...19] Carl Hewitt and Jeff Inman. DAI betwixt and be- tween: From "intelligent agents" to open systems sci- ence. IEEE Transactions on Systems, Man

  5. NOVEL ATYPICAL ANTIPSYCHOTIC AGENTS

    Directory of Open Access Journals (Sweden)

    Vijay Vinay

    2011-05-01

    Full Text Available Antipsychotics are a group of drugs commonly but not exclusively used to treat psychosis. Antipsychotic agents are grouped in two categories: Typical and Atypical antipsychotics. The first antipsychotic was chlorpromazine, which was developed as a surgical anesthetic. The first atypical anti-psychotic medication, clozapine, was discovered in the 1950s, and introduced in clinical practice in the 1970s. Both typical and atypical antipsychotics are effective in reducing positive and negative symptoms of schizophrenia. Blockade of D2 receptor in mesolimbic pathway is responsible for antipsychotic action. Typical antipsychotics are not particularly selective and also block Dopamine receptors in the mesocortical pathway, tuberoinfundibular pathway, and the nigrostriatal pathway. Blocking D2 receptors in these other pathways is thought to produce some of the unwanted side effects. Atypical antipsychotics differ from typical psychotics in their "limbic-specific" dopamine type 2 (D2-receptor binding and high ratio of serotonin type 2 (5-HT2-receptor binding to D2. Atypical antipsychotics are associated with a decreased capacity to cause EPSs, TD, narcoleptic malignant syndrome, and hyperprolactinemia. Atypical antipsychotic agents were developed in response to problems with typical agents, including lack of efficacy in some patients, lack of improvement in negative symptoms, and troublesome adverse effects, especially extrapyramidal symptoms (EPSs and tardive dyskinesia (TD.

  6. New and emerging antifungal agents: impact on respiratory infections.

    Science.gov (United States)

    Feldmesser, Marta

    2003-01-01

    Fungal pathogens are increasingly important causes of respiratory disease, yet the number of antifungal agents available for clinical use is limited. Use of amphotericin B deoxycholate is hampered by severe toxicity. Triazole agents currently available have significant drug interactions; fluconazole has a limited spectrum of activity and itraconazole was, until recently, available only in oral formulations with limited bioavailability. The development of resistance to all three agents is increasingly being recognized and some filamentous fungi are resistant to the action of all of these agents. In the past few years, new antifungal agents and new formulations of existing agents have become available.The use of liposomal amphotericin B preparations is associated with reduced, but still substantial, rates of nephrotoxicity and infusion-related reactions. An intravenous formulation of itraconazole has been introduced, and several new triazole agents have been developed, with the view of identifying agents that have enhanced potency, broader spectra of action and improved pharmacodynamic properties. One of these, voriconazole, has completed large-scale clinical trials. In addition, caspofungin, the first of a new class of agents, the echinocandins, which inhibit cell wall glucan synthesis, was approved for use in the US in 2001 as salvage therapy for invasive aspergillosis. It is hoped that the availability of these agents will have a significant impact on the morbidity and mortality of fungal respiratory infections. However, at the present time, our ability to assess their impact is limited by the problematic nature of conducting trials for antifungal therapy.

  7. Matematica Natural.

    Science.gov (United States)

    Lozano, Patricia; Medearis, Linda

    Matematica Natural (Natural Mathematics) is a mathematics curriculum for young children based on the assumption that they learn mathematics through concrete, real life, relevant experiences and that educational differences rather than cultural differences influence math achievement. The curriculum uses hands-on materials and activities to teach…

  8. Natur formet

    DEFF Research Database (Denmark)

    Søberg, Martin

    2011-01-01

    Anmeldelse af Malene Hauxner, "Fra naturlig natur til SUPERNATUR – Europæisk landskabsarkitektur 1967-2007 set fra Danmark", Risskov: Ikaros Press, 2011.......Anmeldelse af Malene Hauxner, "Fra naturlig natur til SUPERNATUR – Europæisk landskabsarkitektur 1967-2007 set fra Danmark", Risskov: Ikaros Press, 2011....

  9. Nature Detectives

    Science.gov (United States)

    Harr, Natalie; Lee, Richard E.; Jr.

    2010-01-01

    Richard Louv's "Last Child in the Woods" (2008) added to a growing consensus to get children outside and experiencing nature. Using ideas from place-based education, the authors present a simple year-long project that brings science, nature, and other curriculum standards to life right in your school yard. With a focus on journaling, this project…

  10. Matematica Natural.

    Science.gov (United States)

    Lozano, Patricia; Medearis, Linda

    Matematica Natural (Natural Mathematics) is a mathematics curriculum for young children based on the assumption that they learn mathematics through concrete, real life, relevant experiences and that educational differences rather than cultural differences influence math achievement. The curriculum uses hands-on materials and activities to teach…

  11. Nature Detectives

    Science.gov (United States)

    Harr, Natalie; Lee, Richard E.; Jr.

    2010-01-01

    Richard Louv's "Last Child in the Woods" (2008) added to a growing consensus to get children outside and experiencing nature. Using ideas from place-based education, the authors present a simple year-long project that brings science, nature, and other curriculum standards to life right in your school yard. With a focus on journaling, this project…

  12. Natural death.

    Science.gov (United States)

    Oehmichen, M; Meissner, C

    2000-01-01

    The increasing age of every human being is the beginning of the end of life, an obviously natural process, but any attempt to define the term 'natural death' soon encounters difficulties in defining what is meant by 'natural'. In the industrialized countries of the West, for example 'natural death' is thought of as the opposite of non-natural types of death such as accidental death, suicide, and homicide. The aim of our present survey is to discuss the meaning of the term 'natural death' under a clinical, a forensic and a scientific point of view with regard to recent developments especially in molecular biology. If there are 'external' physical influences, a medical-technical manipulation, a therapeutic or molecular biological intervention cannot be definitely ruled out as the cause of death, then use of the term 'natural death' in general is open to question. It will only remain meaningful if it can be applied with a specific meaning in definite practical situations. Current research and medical technology, however, do not allow use of the term 'natural death' in its conventional sense: it can thus be stricken from the medical vocabulary. Copyright 2000 S. Karger AG, Basel

  13. Empirical agent-based land market: Integrating adaptive economic behavior in urban land-use models

    NARCIS (Netherlands)

    Filatova, Tatiana

    2015-01-01

    This paper introduces an economic agent-based model of an urban housing market. The RHEA (Risks and Hedonics in Empirical Agent-based land market) model captures natural hazard risks and environmental amenities through hedonic analysis, facilitating empirical agent-based land market modeling. RHEA i

  14. Dissonant Nature

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2013-01-01

    Nature restoration is far from being a neural undertaking. Just like any other type of heritage production it can be the source of dissonance – ‘our’ nature is not necessary ‘their’ nature. Often this dissonance is managed in ways, which are not particular sensitive to site......-specificity. As exemplified by the Skjern River Restoration Project (1999-2003), one interpretation of the landscape sometimes suppresses other valid interpretations neglecting its diverse history. Landscape architecture might, however, provide an alternative approach to nature restoration that is more site specific...... and allows for multiple interpretations to coexist. Evidence can be found in the Re-naturalization of River Aire (2002-2015), a restoration project, which reveals approaches that could be labelled landscape architecture specific....

  15. [Fiber as a carcinogenic agent].

    Science.gov (United States)

    Pott, F

    1987-04-01

    According to the findings that long, thin, and durable fibres have a high carcinogenic potency after intrapleural and intraperitoneal administration, the elongated shape of a particle represents a carcinogenic agent; this physical phenomenon is a special cause of cancer. It induces a biological process which can lead to cancer by several as yet unknown steps. However, the properties of the material the fibres are made of determine the carcinogenic potency of a fibre in a secondary way although they do not seem to be responsible for the true carcinogenic agent. For example, these properties determine the degree of solubility and flexibility. The persistence of fibres in the tissue is a very important property with regard to their carcinogenic effect because the formation of a tumour takes many years or some decades. It can be assumed that a fibre has to remain by the bronchial or serosa tissue until the induction of tumour cells occurs. If this hypothesis is correct, there could be a "durability threshold value" for fibres whose length and diameter would otherwise indicate a high carcinogenic potency. There are indications that other fibre properties apart from length, diameter and durability are important for tumour induction, however, at present, they cannot be included in a definition of carcinogenic fibres. It is proposed to classify all natural and man-made mineral fibres with an aspect ratio of greater than 5:1 as carcinogenic when they are longer than 3 microns, thinner than 1 micron (or can split into such fine fibres) and when they can persist in the tissue for more than 3 years.

  16. Drinking Peroxide as 'Natural' Cure Leads to Dangerous Blood Clots

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163513.html Drinking Peroxide as 'Natural' Cure Leads to Dangerous Blood Clots ... 9, 2017 (HealthDay News) -- Ingesting high-concentration hydrogen peroxide as a "natural cure" or cleansing agent may ...

  17. Medicinal agents in the metabolic syndrome.

    Science.gov (United States)

    Baños, G; Pérez-Torres, I; El Hafidi, M

    2008-10-01

    The metabolic syndrome (MS) has become a worldwide health problem. It is difficult for patients to follow a diet/exercise regime that would improve their symptoms, therefore the investigation of agents that may deal with its more serious aspects is an important medical field for research. The cardiovascular consequences associated with the syndrome and some of the therapeutic approaches are discussed. The different agents can be divided into several groups: Inorganic/ organic: Zinc complexes with garlic components as insulino-mimetics; Selenium as antioxidant; Copper, Zinc and Manganese as microcomponents of antioxidant enzymes. Organic: Natural or Synthetic: Glycine is effective in lowering blood pressure, TBARS, intra-abdominal fat tissue and triglycerides in sucrose-fed rats. Pharmaceutical products: Fibrates, Lipid-lowering drugs. Antidiabetics. Anti-gout agents. On the other hand there are natural products such as those of animal origin: Sex hormones (also synthetic) used in the problems of menopause and hypoandrogenism frequently found in the MS, antioxidant Omega-3-oils (fish oils) or Vegetal: for example Digitalis pupurea, century-old cardiovascular medication as well as Magnolia officinalis; Spirulina maxima with beneficial effects as antioxidant and lipid-lowering agent, among others. Prickly Pear Cacti. (Opuntia Ficus- Indica Cochlospermum vitifolium (Willd.) Spreng) whose many properties against diabetes and hypercholesterolemia have been empirically known for many years. Perezone (from Perezia plants, a.k.a. Peonia) described as an antiplatelet aggregating agent. The mixed elements in the Mediterranean diet: Fish, salads (peppers, tomatoes), olive oil, garlic, red wine which combines fish oils, garlic and avocado as well as antioxidants from the rest of its components.

  18. Agents Play Mix-game

    CERN Document Server

    Gou, C

    2005-01-01

    In mix-game which is an extension of minority game, there are two groups of agents; group1 plays the majority game, but the group2 plays the minority game. This paper studies the change of the average winnings of agents and volatilities vs. the change of mixture of agents in mix-game model. It finds that the correlations between the average winnings of agents and the mean of local volatilities are different with different combinations of agent memory length when the proportion of agents in group 1 increases. This study result suggests that memory length of agents in group1 be smaller than that of agent in group2 when mix-game model is used to simulate the financial markets.

  19. Agent Based Modeling Applications for Geosciences

    Science.gov (United States)

    Stein, J. S.

    2004-12-01

    Agent-based modeling techniques have successfully been applied to systems in which complex behaviors or outcomes arise from varied interactions between individuals in the system. Each individual interacts with its environment, as well as with other individuals, by following a set of relatively simple rules. Traditionally this "bottom-up" modeling approach has been applied to problems in the fields of economics and sociology, but more recently has been introduced to various disciplines in the geosciences. This technique can help explain the origin of complex processes from a relatively simple set of rules, incorporate large and detailed datasets when they exist, and simulate the effects of extreme events on system-wide behavior. Some of the challenges associated with this modeling method include: significant computational requirements in order to keep track of thousands to millions of agents, methods and strategies of model validation are lacking, as is a formal methodology for evaluating model uncertainty. Challenges specific to the geosciences, include how to define agents that control water, contaminant fluxes, climate forcing and other physical processes and how to link these "geo-agents" into larger agent-based simulations that include social systems such as demographics economics and regulations. Effective management of limited natural resources (such as water, hydrocarbons, or land) requires an understanding of what factors influence the demand for these resources on a regional and temporal scale. Agent-based models can be used to simulate this demand across a variety of sectors under a range of conditions and determine effective and robust management policies and monitoring strategies. The recent focus on the role of biological processes in the geosciences is another example of an area that could benefit from agent-based applications. A typical approach to modeling the effect of biological processes in geologic media has been to represent these processes in

  20. Product and Agent

    DEFF Research Database (Denmark)

    Montecino, Alex; Valero, Paola

    2015-01-01

    In this paper we will explore how the “mathematics teacher” becomes a subject and, at the same time, is subjected as part of diverse dispositive of power. We argue that the mathematics teacher becomes both a product and a social agent, which has been set, within current societies, from the ideas...... of globalization, social progress, and competitive logic. For our approximation, we use the concepts societies of control, dispositive, and discourses from a Foucault–Deleuze toolbox. Our purpose is to cast light on the social and cultural constitution of the ways of thinking about the mathematics teacher. Hence...

  1. Agentes selladores en endodoncia

    OpenAIRE

    2003-01-01

    Recibido: Noviembre 2002 Aceptado: Enero 2003 La gutapercha sigue siendo uno de los materiales predilectos, pero debido a su falta de adhesión a las paredes dentinarias, debe estar siempre combinada con un sellador que actúe como interfase entre la masa de gutapercha y la estructura dentaria. El uso de un agente sellador para obturar los conductos radiculares es esencial para el éxito del proceso de obturación. Un buen sellador debe ser biocompatible y bien tolerado por los tejid...

  2. Secure Mobile Trade Agent

    Directory of Open Access Journals (Sweden)

    Musbah M. Aqe

    2007-01-01

    Full Text Available E-commerce on the internet has the ability to produce millions of transactions and a great number of merchants whose supply merchandise over the internet. As a result, it is difficult for entities to roam over every site on the internet and choose the best merchandise to trade. So, in this paper we introduced a mobile trade agent that visit the sites to gather and evaluate the information from merchant servers and decide to trade goods on behalf of the user. We observed that the combination of public key cryptosystem with distributed object technology make this proposed scheme more secure and efficient than the already existed schemes.

  3. Product and Agent

    DEFF Research Database (Denmark)

    Montecino, Alex; Valero, Paola

    2015-01-01

    In this paper we will explore how the “mathematics teacher” becomes a subject and, at the same time, is subjected as part of diverse dispositive of power. We argue that the mathematics teacher becomes both a product and a social agent, which has been set, within current societies, from the ideas...... of globalization, social progress, and competitive logic. For our approximation, we use the concepts societies of control, dispositive, and discourses from a Foucault–Deleuze toolbox. Our purpose is to cast light on the social and cultural constitution of the ways of thinking about the mathematics teacher. Hence...

  4. Antineoplastic agents and thrombotic microangiopathy.

    Science.gov (United States)

    Garcia, Gwenalyn; Atallah, Jean Paul

    2017-03-01

    Thrombotic microangiopathy is an uncommon but reported adverse effect of a variety of antineoplastic drugs, including chemotherapy agents such as mitomycin C and gemcitabine, and newer targeted agents such as the vascular endothelial growth factor inhibitors. We present a review of thrombotic microangiopathy associated with antineoplastic agents and its implications in current cancer therapy.

  5. Cultural Differentiation of Negotiating Agents

    NARCIS (Netherlands)

    Hofstede, G.J.; Jonker, C.M.; Verwaart, D.

    2012-01-01

    Negotiations proceed differently across cultures. For realistic modeling of agents in multicultural negotiations, the agents must display culturally differentiated behavior. This paper presents an agent-based simulation model that tackles these challenges, based on Hofstede’s model of national cultu

  6. Cultural differentiation of negotiating agents

    NARCIS (Netherlands)

    Hofstede, G.J.; Jonker, C.M.; Verwaart, T.

    2010-01-01

    Negotiations proceed differently across cultures. For realistic modeling of agents in multicultural negotiations, the agents must display culturally differentiated behavior. This paper presents an agent-based simulation model that tackles these challenges, based on Hofstede’s model of national cultu

  7. Implementing an Agent Trade Server

    OpenAIRE

    Boman, Magnus; Sandin, Anna

    2003-01-01

    An experimental server for stock trading autonomous agents is presented and made available, together with an agent shell for swift development. The server, written in Java, was implemented as proof-of-concept for an agent trade server for a real financial exchange.

  8. Assigning agents to a line

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moreno-Ternero, Juan D.; Østerdal, Lars Peter Raahave

    2014-01-01

    We consider the problem of assigning agents to slots on a line, where only one agent can be served at a slot and each agent prefers to be served as close as possible to his target. Our focus is on aggregate gap minimizing methods, i.e., those that minimize the total gap between targets and assigned...

  9. Agentes de información Information Agents

    Directory of Open Access Journals (Sweden)

    Alfonso López Yepes

    2005-12-01

    Full Text Available Este artículo realiza un repaso sobre las tipologías de agentes de información y describe aspectos como movilidad, racionalidad y adaptatividad, y el ajuste final de estos conceptos a entornos distribuidos como Internet, donde este tipo de agentes tienen un amplio grado de aplicación. Asimismo, se propone una arquitectura de agentes para un sistema multiagente de recuperación de información donde se aplica un paradigma documental basado en el concepto de ciclo documental.This article summarizes the main information agent types reflecting on issues such as mobility, rationality, adaptability and the final adjustment of this concepts to distributed environments such as the Internet, where this kind of agents has wide range application. Likewise, an information agent architecture is proposed to create a multi-agent information retrieval system in which a documentary paradigm based on the documentary cycle is developed.

  10. Natural Communities

    Data.gov (United States)

    Kansas Data Access and Support Center — This dataset shows the locations of known tracts of high quality natural communities in Kansas, generalized to the PLSS section. It is not a compehensive dataset of...

  11. Natural Propositions

    DEFF Research Database (Denmark)

    Stjernfelt, Frederik

    Preface -- Introduction -- The generality of signs -- Dicisigns -- Some consequences of the dicisign doctrine -- Dicisigns and cognition -- Natural propositions--the evolution of semiotic self-control -- Dicisigns beyond language -- Operational and optimal iconicity in Peirce's diagrammatology...

  12. Natural Propositions

    DEFF Research Database (Denmark)

    Stjernfelt, Frederik

    Preface -- Introduction -- The generality of signs -- Dicisigns -- Some consequences of the dicisign doctrine -- Dicisigns and cognition -- Natural propositions--the evolution of semiotic self-control -- Dicisigns beyond language -- Operational and optimal iconicity in Peirce's diagrammatology...

  13. Rosemary extract and celery-based products used as natural quality enhancers for colonial type salami with different ripening times Extrato de alecrim e produtos derivados do aipo como agentes naturais potencializadores da qualidade de salames coloniais com diferentes tempos de maturação

    Directory of Open Access Journals (Sweden)

    Teresinha Marisa Bertol

    2012-12-01

    Full Text Available This study aimed to evaluate the use of rosemary (Rosmarinus officinalis extract (RE, celery (Apium graveolis, and low levels of NO3 and NO2 as natural agents to enhance the quality of colonial salami. Salami was produced according to three treatments: (A Control: 0.1% curing salt; (B Rosemary: 0.05% curing salt + 0.5% RE (rosemary extract; and (C Rosemary+celery: 0.14% Veg 503 + 0.27% Veg 504 (sea salt plus celery + 0.5% of RE (rosemary extract. There was no effect (P > 0.05 of the treatments on water activity, Na content, and residual NO3 and NO2. Fatty acids C18:2 and C20:4 were reduced (P Objetivou-se avaliar o efeito do extrato de alecrim (EA; Rosmarinus officinalis e do aipo (Apium graveolis e de baixos níveis de adição de NO3 e NO2, como agentes naturais potencializadores da qualidade dos salames coloniais. Foram produzidos salames de acordo com três tratamentos: (A Controle: 0,1% de sal de cura; (B Alecrim: 0,05% de sal de cura + 0,5% de EA; (C Alecrim+aipo: 0,14% de Veg 503 + 0,27% de Veg 504 (sal marinho e aipo + 0,5% de EA. Não houve efeito (p > 0,05 dos tratamentos sobre o conteúdo de Na, atividade de água e NO3 e NO2 residuais. Houve redução (p < 0,05 dos ácidos graxos C18:2 e C20:4 durante o período de maturação no tratamento Controle, indicando sua possível oxidação. O uso do aipo resultou em baixo (p < 0,05 pH no salame. A redução da adição de NO3 e NO2 resultou em salames com coloração mais clara (valores de L* mais elevados, p < 0,05 aos 12 dias de maturação. Conclui-se que o aipo foi efetivo como fonte de NO3 e NO2 para desenvolvimento da cor, mas o baixo pH do produto indica a necessidade de melhor avaliar sua utilização em salames fermentados. Os salames produzidos com EA poderão apresentar diferencial de qualidade pela menor oxidação das gorduras, mas isto necessita ser confirmado em estudo futuros.

  14. [New agents for hypercholesterolemia].

    Science.gov (United States)

    Pintó, Xavier; García Gómez, María Carmen

    2016-02-19

    An elevated proportion of high cardiovascular risk patients do not achieve the therapeutic c-LDL goals. This owes to physicians' inappropriate or insufficient use of cholesterol lowering medications or to patients' bad tolerance or therapeutic compliance. Another cause is an insufficient efficacy of current cholesterol lowering drugs including statins and ezetimibe. In addition, proprotein convertase subtilisin kexin type 9 inhibitors are a new cholesterol lowering medications showing safety and high efficacy to reduce c-LDL in numerous already performed or underway clinical trials, potentially allowing an optimal control of hypercholesterolemia in most patients. Agents inhibiting apolipoprotein B synthesis and microsomal transfer protein are also providing a new potential to decrease cholesterol in patients with severe hypercholesterolemia and in particular in homozygote familial hypercholesterolemia. Last, cholesteryl ester transfer protein inhibitors have shown powerful effects on c-HDL and c-LDL, although their efficacy in cardiovascular prevention and safety has not been demonstrated yet. We provide in this article an overview of the main characteristics of therapeutic agents for hypercholesterolemia, which have been recently approved or in an advanced research stage. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  15. Holograms as Teaching Agents

    Science.gov (United States)

    Walker, Robin A.

    2013-02-01

    Hungarian physicist Dennis Gabor won the Pulitzer Prize for his 1947 introduction of basic holographic principles, but it was not until the invention of the laser in 1960 that research scientists, physicians, technologists and the general public began to seriously consider the interdisciplinary potentiality of holography. Questions around whether and when Three-Dimensional (3-D) images and systems would impact American entertainment and the arts would be answered before educators, instructional designers and students would discover how much Three-Dimensional Hologram Technology (3DHT) would affect teaching practices and learning environments. In the following International Symposium on Display Holograms (ISDH) poster presentation, the author features a traditional board game as well as a reflection hologram to illustrate conventional and evolving Three-Dimensional representations and technology for education. Using elements from the American children's toy Operation® (Hasbro, 2005) as well as a reflection hologram of a human brain (Ko, 1998), this poster design highlights the pedagogical effects of 3-D images, games and systems on learning science. As teaching agents, holograms can be considered substitutes for real objects, (human beings, organs, and animated characters) as well as agents (pedagogical, avatars, reflective) in various learning environments using many systems (direct, emergent, augmented reality) and electronic tools (cellphones, computers, tablets, television). In order to understand the particular importance of utilizing holography in school, clinical and public settings, the author identifies advantages and benefits of using 3-D images and technology as instructional tools.

  16. Amphoteric surface active agents

    Directory of Open Access Journals (Sweden)

    Eissa, A.M. F.

    1995-10-01

    Full Text Available 2-[trimethyl ammonium, triethyl ammonium, pyridinium and 2-amino pyridinium] alkanoates, four series of surface active agents containing carbon chain C12, C14, C16 and C18carbon atoms, were prepared. Their structures were characterized by microanalysis, infrared (IR and nuclear magnetic resonance (NMR. Surface and interfacial tension, Krafft point, wetting time, emulsification power, foaming height and critical micelle concentration (cmc were determined and a comparative study was made between their chemical structure and surface active properties. Antimicrobial activity of these surfactants was also determined.

    Se prepararon cuatro series de agentes tensioactivos del tipo 2-[trimetil amonio, trietil amonio, piridinio y 2-amino piridinio] alcanoatos, que contienen cadenas carbonadas con C12, C14, C16 y C18 átomos de carbono.
    Se determinaron la tensión superficial e interfacial, el punto de Krafft, el tiempo humectante, el poder de emulsionamiento, la altura espumante y la concentración critica de miscela (cmc y se hizo un estudio comparativo entre la estructura química y sus propiedades tensioactivas. Se determinó también la actividad antimicrobiana de estos tensioactivos. Estas estructuras se caracterizaron por microanálisis, infrarrojo (IR y resonancia magnética nuclear (RMN.

  17. Embodied artificial agents for understanding human social cognition.

    Science.gov (United States)

    Wykowska, Agnieszka; Chaminade, Thierry; Cheng, Gordon

    2016-05-05

    In this paper, we propose that experimental protocols involving artificial agents, in particular the embodied humanoid robots, provide insightful information regarding social cognitive mechanisms in the human brain. Using artificial agents allows for manipulation and control of various parameters of behaviour, appearance and expressiveness in one of the interaction partners (the artificial agent), and for examining effect of these parameters on the other interaction partner (the human). At the same time, using artificial agents means introducing the presence of artificial, yet human-like, systems into the human social sphere. This allows for testing in a controlled, but ecologically valid, manner human fundamental mechanisms of social cognition both at the behavioural and at the neural level. This paper will review existing literature that reports studies in which artificial embodied agents have been used to study social cognition and will address the question of whether various mechanisms of social cognition (ranging from lower- to higher-order cognitive processes) are evoked by artificial agents to the same extent as by natural agents, humans in particular. Increasing the understanding of how behavioural and neural mechanisms of social cognition respond to artificial anthropomorphic agents provides empirical answers to the conundrum 'What is a social agent?'

  18. Protective Effects of Chrysin Against Drugs and Toxic Agents.

    Science.gov (United States)

    Samarghandian, Saeed; Farkhondeh, Tahereh; Azimi-Nezhad, Mohsen

    2017-01-01

    Polyphenolic compounds, especially flavonoids, are known as the most common chemical class of phytochemicals, which possess a multiple range of health-promoting effects. Flavonoids are ubiquitous in nature. They are also present in food, providing an essential link between diet and prevention of several diseases. Chrysin (CH), a natural flavonoid, was commonly found in propolis and honey and traditionally used in herbal medicine. A growing body of scientific evidence has shown that CH possesses protective effects against toxic agents in various animal tissues, including brain, heart, liver, kidney, and lung. This study found that CH may be effective in disease management induced by toxic agents. However, due to the lack of information on human, further studies are needed to determine the efficacy of CH as an antidote agent in human. The present article aimed to critically review the available literature data regarding the protective effects of CH against toxic agent-induced toxicities as well as its possible mechanisms.

  19. Agent-oriented Software Engineering

    Institute of Scientific and Technical Information of China (English)

    GUAN Xu; CHENG Ming; LIU Bao

    2001-01-01

    An increasing number of computer systems are being viewed in terms of autonomous agents.Most people believe that agent-oriented approach is well suited to design and build complex systems. Yet. todate, little effort had been devoted to discuss the advantages of agent-oriented approach as a mainstreamsoftware engineering paradigm. Here both of this issues and the relation between object-oriented and agent-oriented will be argued. we describe an agent-oriented methodology and provide a quote for designing anauction system.

  20. Microbial Resistance to Triclosan: A Case Study in Natural Selection

    Science.gov (United States)

    Serafini, Amanda; Matthews, Dorothy M.

    2009-01-01

    Natural selection is the mechanism of evolution caused by the environmental selection of organisms most fit to reproduce, sometimes explained as "survival of the fittest." An example of evolution by natural selection is the development of bacteria that are resistant to antimicrobial agents as a result of exposure to these agents. Triclosan, which…

  1. Health protection: Toxic agent and radiation control.

    Science.gov (United States)

    1983-01-01

    It is estimated that of the four million chemical compounds which have been synthesized or isolated from natural materials, more than 55,000 are produced commercially. Approximately 1,000 new compounds are introduced annually; pesticide formulations alone contain about 1,500 active chemical ingredients. Diagnostic x-rays are used extensively in medicine and dentistry. Over 2,000 chemicals are suspected carcinogens in laboratory animals--epidemiologic evidence suggests that 26 of these chemicals and/or industrial processes are carcinogenic in humans. More than 20 agents are known to be associated with birth defects in humans; 47 atmospheric contaminants have been identified in animal studies as recognized carcinogens and 128 as mutagens; and, of the 765 contaminants identified in drinking water, 12 were recognized carcinogens, 31 suspected carcinogens, and 59 mutagens. Radiation has known carcinogenic and genetic effects at significant levels of exposure. Problems with toxic agents and radiation sources occur not only in industry, but also in medical and dental care (x-rays and drugs), agriculture (pesticides and herbicides), Government activities (biological and chemical agents), consumer products (incorrect use of consumer products which contain toxic substances), and natural sources (fungal products).

  2. Chemical Warfare Agent Degradation and Decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Talmage, Sylvia Smith [ORNL; Watson, Annetta Paule [ORNL; Hauschild, Veronique [U.S. Environmental Protection Agency; Munro, Nancy B [ORNL; King, J. [U.S. Army Environmental Center

    2007-02-01

    The decontamination of chemical warfare agents (CWA) from structures, environmental media, and even personnel has become an area of particular interest in recent years due to increased homeland security concerns. In addition to terrorist attacks, scenarios such as accidental releases of CWA from U.S. stockpile sites or from historic, buried munitions are also subjects for response planning. To facilitate rapid identification of practical and effective decontamination approaches, this paper reviews pathways of CWA degradation by natural means as well as those resulting from deliberately applied solutions and technologies; these pathways and technologies are compared and contrasted. We then review various technologies, both traditional and recent, with some emphasis on decontamination materials used for surfaces that are difficult to clean. Discussion is limited to the major threat CWA, namely sulfur mustard (HD, bis(2-chloroethyl)sulfide), VX (O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothioate), and the G-series nerve agents. The principal G-agents are GA (tabun, ethyl N,N-dimethylphosphoramidocyanidate), GB (sarin, isopropyl methylphosphonofluoridate), and GD (soman, pinacolyl methylphosphonofluoridate). The chemical decontamination pathways of each agent are outlined, with some discussion of intermediate and final degradation product toxicity. In all cases, and regardless of the CWA degradation pathway chosen for decontamination, it will be necessary to collect and analyze pertinent environmental samples during the treatment phase to confirm attainment of clearance levels.

  3. Fuzzy Constraint-Based Agent Negotiation

    Institute of Scientific and Technical Information of China (English)

    Menq-Wen Lin; K. Robert Lai; Ting-Jung Yu

    2005-01-01

    Conflicts between two or more parties arise for various reasons and perspectives. Thus, resolution of conflicts frequently relies on some form of negotiation. This paper presents a general problem-solving framework for modeling multi-issue multilateral negotiation using fuzzy constraints. Agent negotiation is formulated as a distributed fuzzy constraint satisfaction problem (DFCSP). Fuzzy constrains are thus used to naturally represent each agent's desires involving imprecision and human conceptualization, particularly when lexical imprecision and subjective matters are concerned. On the other hand, based on fuzzy constraint-based problem-solving, our approach enables an agent not only to systematically relax fuzzy constraints to generate a proposal, but also to employ fuzzy similarity to select the alternative that is subject to its acceptability by the opponents. This task of problem-solving is to reach an agreement that benefits all agents with a high satisfaction degree of fuzzy constraints, and move towards the deal more quickly since their search focuses only on the feasible solution space. An application to multilateral negotiation of a travel planning is provided to demonstrate the usefulness and effectiveness of our framework.

  4. Games and Agents: Designing Intelligent Gameplay

    Directory of Open Access Journals (Sweden)

    F. Dignum

    2009-01-01

    Full Text Available There is an attention shift within the gaming industry toward more natural (long-term behavior of nonplaying characters (NPCs. Multiagent system research offers a promising technology to implement cognitive intelligent NPCs. However, the technologies used in game engines and multiagent platforms are not readily compatible due to some inherent differences of concerns. Where game engines focus on real-time aspects and thus propagate efficiency and central control, multiagent platforms assume autonomy of the agents. Increased autonomy and intelligence may offer benefits for a more compelling gameplay and may even be necessary for serious games. However, it raises problems when current game design techniques are used to incorporate state-of-the-art multiagent system technology. In this paper, we will focus on three specific problem areas that arise from this difference of view: synchronization, information representation, and communication. We argue that the current attempts for integration still fall short on some of these aspects. We show that to fully integrate intelligent agents in games, one should not only use a technical solution, but also a design methodology that is amenable to agents. The game design should be adjusted to incorporate the possibilities of agents early on in the process.

  5. Flexible, secure agent development framework

    Science.gov (United States)

    Goldsmith,; Steven, Y [Rochester, MN

    2009-04-07

    While an agent generator is generating an intelligent agent, it can also evaluate the data processing platform on which it is executing, in order to assess a risk factor associated with operation of the agent generator on the data processing platform. The agent generator can retrieve from a location external to the data processing platform an open site that is configurable by the user, and load the open site into an agent substrate, thereby creating a development agent with code development capabilities. While an intelligent agent is executing a functional program on a data processing platform, it can also evaluate the data processing platform to assess a risk factor associated with performing the data processing function on the data processing platform.

  6. Decentralized Bayesian reinforcement learning for online agent collaboration

    OpenAIRE

    Teacy, W.T.L.; G. Chalkiadakis; Farinelli, A.; Rogers, A.; Jennings, N.R.; McClean, S.; Parr, G.

    2012-01-01

    Solving complex but structured problems in a decentralized manner via multiagent collaboration has received much attention in recent years. This is natural, as on one hand, multiagent systems usually possess a structure that determines the allowable interactions among the agents; and on the other hand, the single most pressing need in a cooperative multiagent system is to coordinate the local policies of autonomous agents with restricted capabilities to serve a system-wide goal. The presence ...

  7. Agent-Based Design for E-learning Environment

    Directory of Open Access Journals (Sweden)

    Khadidja Harbouche

    2007-01-01

    Full Text Available We presented an agent-based e-learning environment. Our aim was to allow many users to interact collectively and intelligently with the environment. In this cooperation model, human users and artificial agents carry out tasks in the learners’ service. We define the internal structure of our kernel supposed to work within Internet/Intranet settings. Design was structured in three parts: individual learning space, collaborative space, and cooperative space. We advocate the employment of an agent-based approach, a suitable for two main reasons: agents were a natural metaphor of human acts, and the learning systems are generally complex. Prometheus methodology used for the design and emphasis placed on the agent-based features.

  8. Multi-agent cooperative intrusion response in mobile adhoc networks

    Institute of Scientific and Technical Information of China (English)

    Yi Ping; Zou Futai; Jiang Xinghao; Li Jianhua

    2007-01-01

    The nature of adhoc networks makes them vulnerable to security attacks. Many security technologies such as intrusion prevention and intrusion detection are passive in response to intrusions in that their countermeasures are only to protect the networks, and there is no automated network-wide counteraction against detected intrusions. the architecture of cooperation intrusion response based multi-agent is propose. The architecture is composed of mobile agents. Monitor agent resides on every node and monitors its neighbor nodes. Decision agent collects information from monitor nodes and detects an intrusion by security policies. When an intruder is found in the architecture, the block agents will get to the neighbor nodes of the intruder and form the mobile firewall to isolate the intruder. In the end, we evaluate it by simulation.

  9. Mobile Agent Platform and Naming Scheme of Agents%移动代理平台及其代理命名方法

    Institute of Scientific and Technical Information of China (English)

    Sudin SHRESTHA; 徐拾义; Jagath RATNAYEKE

    2004-01-01

    Mobile agent technology has drawn a tremendous amount of attention from researchers in distributed computing recently as it promises to provide an elegant and efficient way of solving complex distributed problems, as well as offering a new approach to human-computer-interaction. In mobile agent systems, the mobile agent travels autonomously from one computer to another within the agent enabled networks, executes itself in the agent execution environment, collects useful information and makes its own decision on behalf of its owner. This mobility nature of mobile agent demands its unique name in the whole network otherwise it gets lost or conflicts with other mobile agent having same name. This paper proposes a naming scheme which promises a unique name for a mobile agent within that network.

  10. Naturalness redux

    CERN Document Server

    Fabbrichesi, Marco

    2015-01-01

    The idea of naturalness, as originally conceived, refers only to the finite renormalization of the Higgs boson mass induced by the introduction of heavier states. In this respect, naturalness is still a powerful heuristic principle in model building beyond the standard model whenever new massive states are coupled to the Higgs field. The most compelling case is provided by the generation of neutrino masses. In this paper we confront this problem from a new perspective. The right-handed sector responsible for the seesaw mechanism---which introduces a large energy threshold above the electroweak scale---is made supersymmetric to comply with naturalness while the standard model is left unchanged and non-supersymmetric. Cancellations necessary to the naturalness requirement break down only at two loops, thus offering the possibility to increase the right-handed neutrino mass scale up to one order of magnitude above the usual values allowed by naturalness. If also the weak boson sector of the standard model is mad...

  11. MORBIDITY AGENTS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Shrivastava Neelesh

    2011-09-01

    Full Text Available This paper discuss on clinical representation of morbid jealousy which often termed delusional jealousy or ‘Othello Syndrome’ is a psychiatric condition where a lover believes against all reason and their beloved is being sexually unfaithful. Patients will be preoccupied with their partner’s perceived lack of sexual fidelity and will often behave in an unacceptable or extreme way as they endeavor to prove their ideas. Misuse of any psychomotor is an important association cause morbidity jealousy agents, like CNS stimulants that release the catecholamine, particularly dopamine, from pre synaptic terminals substance should be treated as a priority. Where higher levels of violence are reported Sildenafil may be useful as a diagnostic as well as therapeutic test in such cases .Many studies have shown an association between high alcohol consumption and developing morbid jealousy. Amphetamine-induced psychosis has been extensively studied because of its close resemblance to schizophrenia.

  12. Emancipating Nature

    DEFF Research Database (Denmark)

    Munk, Anders Kristian

    2012-01-01

    The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations of it – hydrodyn......The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations...... of it – hydrodynamic equations – which have their own anticipations and place their own demands on their modellers. Through the experience of a flood modelling apprenticeship I argue that the taking-place of such anticipations paradoxically relies on the birth of a hybrid, the model-modeller, and thus on a nature...

  13. Ley Natural

    OpenAIRE

    2010-01-01

    1. La expresión «ley natural» en la historia de las ideas. Uso ético y uso científico. 2. La cuestión de las leyes naturales en el ámbito de la naturaleza y en el ámbito de la conducta humana. 3. La ley natural como teoría moral se desarrolla en dos planos: a) plano práctico: el obrar humano responde a razones, depende de principios que constituyen una única ley; b) plano de fundamentación metafísica: la ley natural como participación de la ley eterna en la criatura racional. 4. La ley nat...

  14. Emancipating Nature

    DEFF Research Database (Denmark)

    Munk, Anders Kristian

    2012-01-01

    The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations of it – hydrodyn......The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations...... of it – hydrodynamic equations – which have their own anticipations and place their own demands on their modellers. Through the experience of a flood modelling apprenticeship I argue that the taking-place of such anticipations paradoxically relies on the birth of a hybrid, the model-modeller, and thus on a nature...

  15. Natural games

    CERN Document Server

    Anttila, Jani

    2011-01-01

    Behavior in the context of game theory is described as a natural process that follows the 2nd law of thermodynamics. The rate of entropy increase as the payoff function is derived from statistical physics of open systems. The thermodynamic formalism relates everything in terms of energy and describes various ways to consume free energy. This allows us to associate game theoretical models of behavior to physical reality. Ultimately behavior is viewed as a physical process where flows of energy naturally select ways to consume free energy as soon as possible. This natural process is, according to the profound thermodynamic principle, equivalent to entropy increase in the least time. However, the physical portrayal of behavior does not imply determinism. On the contrary, evolutionary equation for open systems reveals that when there are three or more degrees of freedom for behavior, the course of a game is inherently unpredictable in detail because each move affects motives of moves in the future. Eventually, wh...

  16. UTBot: A Virtual Agent Platform for Teaching Agent System Design

    Directory of Open Access Journals (Sweden)

    In-Cheol Kim

    2007-02-01

    Full Text Available We introduce UTBot, a virtual agent platform for teaching agent system design. UTBot implements a client for the Unreal Tournament game server and Gamebots system. It provides students with the basic functionality required to start developing their own intelligent virtual agents to play autonomously UT games. UTBot includes a generic agent architecture, CAA (Context-sensitive Agent Architecture, a domain-specific world model, a visualization tool, several basic strategies (represented by internal modes and internal behaviors, and skills (represented by external behaviors. The CAA architecture can support complex long-term behaviors as well as reactive short-term behaviors. It also realizes high context-sensitivity of behaviors. We also discuss our experience using UTBot as a pedagogical tool for teaching agent system design in undergraduate Artificial Intelligence course.

  17. The Development of Sugar-Based Anti-Melanogenic Agents.

    Science.gov (United States)

    Bin, Bum-Ho; Kim, Sung Tae; Bhin, Jinhyuk; Lee, Tae Ryong; Cho, Eun-Gyung

    2016-04-16

    The regulation of melanin production is important for managing skin darkness and hyperpigmentary disorders. Numerous anti-melanogenic agents that target tyrosinase activity/stability, melanosome maturation/transfer, or melanogenesis-related signaling pathways have been developed. As a rate-limiting enzyme in melanogenesis, tyrosinase has been the most attractive target, but tyrosinase-targeted treatments still pose serious potential risks, indicating the necessity of developing lower-risk anti-melanogenic agents. Sugars are ubiquitous natural compounds found in humans and other organisms. Here, we review the recent advances in research on the roles of sugars and sugar-related agents in melanogenesis and in the development of sugar-based anti-melanogenic agents. The proposed mechanisms of action of these agents include: (a) (natural sugars) disturbing proper melanosome maturation by inducing osmotic stress and inhibiting the PI3 kinase pathway and (b) (sugar derivatives) inhibiting tyrosinase maturation by blocking N-glycosylation. Finally, we propose an alternative strategy for developing anti-melanogenic sugars that theoretically reduce melanosomal pH by inhibiting a sucrose transporter and reduce tyrosinase activity by inhibiting copper incorporation into an active site. These studies provide evidence of the utility of sugar-based anti-melanogenic agents in managing skin darkness and curing pigmentary disorders and suggest a future direction for the development of physiologically favorable anti-melanogenic agents.

  18. Of Social Engineers & Corporate Espionage Agents

    DEFF Research Database (Denmark)

    Yeboah-Boateng, Ezer Osei

    2013-01-01

    indicate that financial and ICT oriented SMEs are mostly targeted, and the impact range from loss of sensitive data, loss of corporate resources, loss of market share as well as loss of customer and investor confidence. Since most social engineers capitalize on the end-user vulnerabilities and their sense......The purpose of this study is to create the awareness of cyber-security threats due to social engineers and corporate espionage agents, and to offer some mitigation measures aimed at minimizing the impact of insider attacks on SMEs in developing economies. Loyal and trusted employees can pose...... of social norms, effective mitigation measures offered are human centric in nature. Personal and corporate factors that are likely to motivate employees to become espionage agents ought to be addressed. Periodic and on-spot systems audit are to be carried out to effectively monitor any unnecessary...

  19. [Natural selection].

    Science.gov (United States)

    Mayr, E

    1985-05-01

    Much of the resistance against Darwin's theory of natural selection has been due to misunderstandings. It is shown that natural selection is not a tautology and that it is a two-step process. The first step, the production of variation, is under the control of chance; the second step, selection proper, is an anti-chance process, but subject to many constraints. The target of selection is the individual as a whole, and many neutral mutations can be retained as hitchhikers of successful genotypes. Sexual selection results from selection for pure reproductive success.

  20. Provincialising Nature

    DEFF Research Database (Denmark)

    Provincialising Nature: Multidisciplinary Approaches to the Politics of the Environment in Latin America offers a timely analysis of some of the crucial challenges, contradictions and promises within current environmental discourses and practices in the region. This book shows both challenging...... scenarios and original perspectives that have emerged in Latin America in relation to the globally urgent issues of climate change and the environmental crisis. Two interconnected analytical frameworks guide the discussions in the book: the relationship between nature, knowledge and identity and their role...

  1. Kritikkens natur

    DEFF Research Database (Denmark)

    Schatz-Jakobsen, Claus

    1999-01-01

    Artiklen introducerer det nye forskningsfelt inden for samtænkning af litteratur, kultur og natur, den såkaldt økologiske kritik, og kaster et kritisk blik på  dens brug af romantisk litteratur som proto-økologisk kanon.......Artiklen introducerer det nye forskningsfelt inden for samtænkning af litteratur, kultur og natur, den såkaldt økologiske kritik, og kaster et kritisk blik på  dens brug af romantisk litteratur som proto-økologisk kanon....

  2. Natural aerodynamics

    CERN Document Server

    Scorer, R S

    1958-01-01

    Natural Aerodynamics focuses on the mathematics of any problem in air motion.This book discusses the general form of the law of fluid motion, relationship between pressure and wind, production of vortex filaments, and conduction of vorticity by viscosity. The flow at moderate Reynolds numbers, turbulence in a stably stratified fluid, natural exploitation of atmospheric thermals, and plumes in turbulent crosswinds are also elaborated. This text likewise considers the waves produced by thermals, transformation of thin layer clouds, method of small perturbations, and dangers of extra-polation.Thi

  3. Nature Watch

    Science.gov (United States)

    Sterling, Donna R.

    2010-01-01

    Children are naturally curious about the world in which they live. To focus this sense of wonder, have your students investigate their local habitat as it changes over the year. This multiseason study will build connections and add relevance to the habitats that children learn about. This series of activities for grades 4-6 explores the changing…

  4. Nature's Palette

    Science.gov (United States)

    McBride, Brooke B.; Brewer, Carol A.

    2010-01-01

    Flower petals, acorn hats, exoskeletons of beetles, and lichens are just a few of the objects students may find in a surprising array of vivid colors. These tiny examples from nature's palette can be discovered in a school yard, a park, or even along the edges of a paved sidewalk...it simply takes careful observation! This article describes a…

  5. Kritikkens natur

    DEFF Research Database (Denmark)

    Schatz-Jakobsen, Claus

    1999-01-01

    Artiklen introducerer det nye forskningsfelt inden for samtænkning af litteratur, kultur og natur, den såkaldt økologiske kritik, og kaster et kritisk blik på  dens brug af romantisk litteratur som proto-økologisk kanon....

  6. Natural ecosystems

    Science.gov (United States)

    Fleishman, Erica; Belnap, Jayne; Cobb, Neil; Enquist, Carolyn A.F.; Ford, Karl; MacDonald, Glen; Pellant, Mike; Schoennagel, Tania; Schmit, Lara M.; Schwartz, Mark; van Drunick, Suzanne; Westerling, Anthony LeRoy; Keyser, Alisa; Lucas, Ryan

    2013-01-01

    Natural Ecosystems analyzes the association of observed changes in climate with changes in the geographic distributions and phenology (the timing of blossoms or migrations of birds) for Southwestern ecosystems and their species, portraying ecosystem disturbances—such as wildfires and outbreaks of forest pathogens—and carbon storage and release, in relation to climate change.

  7. Odor Classification using Agent Technology

    Directory of Open Access Journals (Sweden)

    Sigeru OMATU

    2014-03-01

    Full Text Available In order to measure and classify odors, Quartz Crystal Microbalance (QCM can be used. In the present study, seven QCM sensors and three different odors are used. The system has been developed as a virtual organization of agents using an agent platform called PANGEA (Platform for Automatic coNstruction of orGanizations of intElligent Agents. This is a platform for developing open multi-agent systems, specifically those including organizational aspects. The main reason for the use of agents is the scalability of the platform, i.e. the way in which it models the services. The system models functionalities as services inside the agents, or as Service Oriented Approach (SOA architecture compliant services using Web Services. This way the adaptation of the odor classification systems with new algorithms, tools and classification techniques is allowed.

  8. Agent-based enterprise integration

    Energy Technology Data Exchange (ETDEWEB)

    N. M. Berry; C. M. Pancerella

    1998-12-01

    The authors are developing and deploying software agents in an enterprise information architecture such that the agents manage enterprise resources and facilitate user interaction with these resources. The enterprise agents are built on top of a robust software architecture for data exchange and tool integration across heterogeneous hardware and software. The resulting distributed multi-agent system serves as a method of enhancing enterprises in the following ways: providing users with knowledge about enterprise resources and applications; accessing the dynamically changing enterprise; locating enterprise applications and services; and improving search capabilities for applications and data. Furthermore, agents can access non-agents (i.e., databases and tools) through the enterprise framework. The ultimate target of the effort is the user; they are attempting to increase user productivity in the enterprise. This paper describes their design and early implementation and discusses the planned future work.

  9. Agent-based enterprise integration

    Energy Technology Data Exchange (ETDEWEB)

    N. M. Berry; C. M. Pancerella

    1998-12-01

    The authors are developing and deploying software agents in an enterprise information architecture such that the agents manage enterprise resources and facilitate user interaction with these resources. The enterprise agents are built on top of a robust software architecture for data exchange and tool integration across heterogeneous hardware and software. The resulting distributed multi-agent system serves as a method of enhancing enterprises in the following ways: providing users with knowledge about enterprise resources and applications; accessing the dynamically changing enterprise; locating enterprise applications and services; and improving search capabilities for applications and data. Furthermore, agents can access non-agents (i.e., databases and tools) through the enterprise framework. The ultimate target of the effort is the user; they are attempting to increase user productivity in the enterprise. This paper describes their design and early implementation and discusses the planned future work.

  10. Anticancer agents from medicinal plants

    Directory of Open Access Journals (Sweden)

    Mohammad Shoeb

    2006-12-01

    Full Text Available Cancer is a major public health burden in both developed and developing countries. Plant derived agents are being used for the treatment of cancer. Several anticancer agents including taxol, vinblas-tine, vincristine, the camptothecin derivatives, topotecan and irinotecan, and etoposide derived from epipodophyllotoxin are in clinical use all over the world. A number of promising agents such as flavopiridol, roscovitine, combretastatin A-4, betulinic acid and silvestrol are in clinical or preclinical development.

  11. Anticancer agents from medicinal plants

    Directory of Open Access Journals (Sweden)

    Mohammad Shoeb

    2006-06-01

    Full Text Available Cancer is a major public health burden in both developed and developing countries. Plant derived agents are being used for the treatment of cancer. Several anticancer agents including taxol, vinblastine, vincristine, the camptothecin derivatives, topotecan and irinotecan, and etoposide derived from epipodophyllotoxin are in clinical use all over the world. A number of promising agents such as flavopiridol, roscovitine, combretastatin A-4, betulinic acid and silvestrol are in clinical or preclinical development.

  12. Research on Negotiating Agent Development

    Institute of Scientific and Technical Information of China (English)

    WEI Ding-guo; PENG Hong

    2004-01-01

    The paper presents a flexible and effective method of development of negotiating agents.A strategy specification, which is specified by a state chart and defeasible rules, can be dynamically inserted into an agent shell incorporating a state chart interpreter and a defeasible logic inference engine, in order to yield a desirable agent.The set of desirable criteria and rules is required to be justified with different context of the application.

  13. Agent 与Multi-Agent System 技术研究%The Research on Agent and Multi-Agent System

    Institute of Scientific and Technical Information of China (English)

    党建武; 韩泉叶; 崔文华

    2002-01-01

    分析了Multi-Agent System 涉及的相关问题,在普通的Multi-Agent System的组织结构的基础上提出了管理服务机构,中介服务机构和主控流动服务机构的Multi-Agent System,并对不同组织结构的Agent之间的协同进行了讨论.

  14. Broad-spectrum antiviral agents

    Directory of Open Access Journals (Sweden)

    Jun-Da eZhu

    2015-05-01

    Full Text Available Development of highly effective, broad-spectrum antiviral agents is the major objective shared by the fields of virology and pharmaceutics. Antiviral drug development has focused on targeting viral entry and replication, as well as modulating cellular defense system. High throughput screening of molecules, genetic engineering of peptides, and functional screening of agents have identified promising candidates for development of optimal broad-spectrum antiviral agents to intervene in viral infection and control viral epidemics. This review discusses current knowledge, prospective applications, opportunities, and challenges in the development of broad-spectrum antiviral agents.

  15. Business Intelligence using Software Agents

    Directory of Open Access Journals (Sweden)

    Ana-Ramona BOLOGA

    2011-12-01

    Full Text Available This paper presents some ideas about business intelligence today and the importance of developing real time business solutions. The authors make an exploration of links between business intelligence and artificial intelligence and focuses specifically on the implementation of software agents-based systems in business intelligence. There are briefly presented some of the few solutions proposed so far that use software agents properties for the benefit of business intelligence. The authors then propose some basic ideas for developing real-time agent-based software system for business intelligence in supply chain management, using Case Base Reasoning Agents.

  16. Saponins from Chinese Medicines as Anticancer Agents

    Directory of Open Access Journals (Sweden)

    Xiao-Huang Xu

    2016-10-01

    Full Text Available Saponins are glycosides with triterpenoid or spirostane aglycones that demonstrate various pharmacological effects against mammalian diseases. To promote the research and development of anticancer agents from saponins, this review focuses on the anticancer properties of several typical naturally derived triterpenoid saponins (ginsenosides and saikosaponins and steroid saponins (dioscin, polyphyllin, and timosaponin isolated from Chinese medicines. These saponins exhibit in vitro and in vivo anticancer effects, such as anti-proliferation, anti-metastasis, anti-angiogenesis, anti-multidrug resistance, and autophagy regulation actions. In addition, related signaling pathways and target proteins involved in the anticancer effects of saponins are also summarized in this work.

  17. Instructable autonomous agents. Ph.D. Thesis

    Science.gov (United States)

    Huffman, Scott Bradley

    1994-01-01

    In contrast to current intelligent systems, which must be laboriously programmed for each task they are meant to perform, instructable agents can be taught new tasks and associated knowledge. This thesis presents a general theory of learning from tutorial instruction and its use to produce an instructable agent. Tutorial instruction is a particularly powerful form of instruction, because it allows the instructor to communicate whatever kind of knowledge a student needs at whatever point it is needed. To exploit this broad flexibility, however, a tutorable agent must support a full range of interaction with its instructor to learn a full range of knowledge. Thus, unlike most machine learning tasks, which target deep learning of a single kind of knowledge from a single kind of input, tutorability requires a breadth of learning from a broad range of instructional interactions. The theory of learning from tutorial instruction presented here has two parts. First, a computational model of an intelligent agent, the problem space computational model, indicates the types of knowledge that determine an agent's performance, and thus, that should be acquirable via instruction. Second, a learning technique, called situated explanation specifies how the agent learns general knowledge from instruction. The theory is embodied by an implemented agent, Instructo-Soar, built within the Soar architecture. Instructo-Soar is able to learn hierarchies of completely new tasks, to extend task knowledge to apply in new situations, and in fact to acquire every type of knowledge it uses during task performance - control knowledge, knowledge of operators' effects, state inferences, etc. - from interactive natural language instructions. This variety of learning occurs by applying the situated explanation technique to a variety of instructional interactions involving a variety of types of instructions (commands, statements, conditionals, etc.). By taking seriously the requirements of flexible

  18. Incorporating BDI Agents into Human-Agent Decision Making Research

    Science.gov (United States)

    Kamphorst, Bart; van Wissen, Arlette; Dignum, Virginia

    Artificial agents, people, institutes and societies all have the ability to make decisions. Decision making as a research area therefore involves a broad spectrum of sciences, ranging from Artificial Intelligence to economics to psychology. The Colored Trails (CT) framework is designed to aid researchers in all fields in examining decision making processes. It is developed both to study interaction between multiple actors (humans or software agents) in a dynamic environment, and to study and model the decision making of these actors. However, agents in the current implementation of CT lack the explanatory power to help understand the reasoning processes involved in decision making. The BDI paradigm that has been proposed in the agent research area to describe rational agents, enables the specification of agents that reason in abstract concepts such as beliefs, goals, plans and events. In this paper, we present CTAPL: an extension to CT that allows BDI software agents that are written in the practical agent programming language 2APL to reason about and interact with a CT environment.

  19. Natural Products from Mangrove Actinomycetes

    Directory of Open Access Journals (Sweden)

    Dong-Bo Xu

    2014-05-01

    Full Text Available Mangroves are woody plants located in tropical and subtropical intertidal coastal regions. The mangrove ecosystem is becoming a hot spot for natural product discovery and bioactivity survey. Diverse mangrove actinomycetes as promising and productive sources are worth being explored and uncovered. At the time of writing, we report 73 novel compounds and 49 known compounds isolated from mangrove actinomycetes including alkaloids, benzene derivatives, cyclopentenone derivatives, dilactones, macrolides, 2-pyranones and sesquiterpenes. Attractive structures such as salinosporamides, xiamycins and novel indolocarbazoles are highlighted. Many exciting compounds have been proven as potential new antibiotics, antitumor and antiviral agents, anti-fibrotic agents and antioxidants. Furthermore, some of their biosynthetic pathways have also been revealed. This review is an attempt to consolidate and summarize the past and the latest studies on mangrove actinomycetes natural product discovery and to draw attention to their immense potential as novel and bioactive compounds for marine drugs discovery.

  20. Natural Fibre-Reinforced Biofoams

    Directory of Open Access Journals (Sweden)

    Anne Bergeret

    2011-01-01

    Full Text Available Starches and polylactic acids (PLAs represent the main biobased and biodegradable polymers with potential industrial availability in the next decades for “bio” foams applications. This paper investigates the improvement of their morphology and properties through processing and materials parameters. Starch foams were obtained by melt extrusion in which water is used as blowing agent. The incorporation of natural fibres (hemp, cellulose, cotton linter, sugarcane, coconut in the starch foam induced a density reduction up to 33%, a decrease in water absorption, and an increase in mechanical properties according to the fibre content and nature. PLA foams were obtained through single-screw extrusion using of a chemical blowing agent that decomposed at the PLA melting temperature. A void content of 48% for PLA and 25% for cellulose fibre-reinforced PLA foams and an improvement in mechanical properties were achieved. The influence of a fibre surface treatment was investigated for both foams.

  1. Satellite (Natural)

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    In its most general sense, any celestial object in orbit around a similar larger object. Thus, for example, the Magellanic Clouds are satellite galaxies of our own Milky Way galaxy. Without qualification, the term is used to mean a body in orbit around a planet; an alternative term is moon. The term natural satellite distinguishes these bodies from artificial satellites—spacecraft placed in orbi...

  2. TACtic- A Multi Behavioral Agent for Trading Agent Competition

    Science.gov (United States)

    Khosravi, Hassan; Shiri, Mohammad E.; Khosravi, Hamid; Iranmanesh, Ehsan; Davoodi, Alireza

    Software agents are increasingly being used to represent humans in online auctions. Such agents have the advantages of being able to systematically monitor a wide variety of auctions and then make rapid decisions about what bids to place in what auctions. They can do this continuously and repetitively without losing concentration. To provide a means of evaluating and comparing (benchmarking) research methods in this area the trading agent competition (TAC) was established. This paper describes the design, of TACtic. Our agent uses multi behavioral techniques at the heart of its decision making to make bidding decisions in the face of uncertainty, to make predictions about the likely outcomes of auctions, and to alter the agent's bidding strategy in response to the prevailing market conditions.

  3. Deliberate evolution in multi-agent systems

    NARCIS (Netherlands)

    Brazier, F.M.T.; Jonker, C.M.; Treur, J.; Wijngaards, N.J.E.

    1998-01-01

    This paper presents an architecture for an agent capable of deliberation about the creation of new agents, and of actually creating a new agent in the multi-agent system, on the basis of this deliberation. After its creation the new agent participates fully in the running multi-agent system. The age

  4. A natural language user interface for fuzzy scope queries

    Institute of Scientific and Technical Information of China (English)

    黄艳; 俞宏峰; 耿卫东; 潘云鹤

    2003-01-01

    This paper presents a two-agent framework to build a natural language query interface for IC information system, focusing more on scope queries in a single English sentence. The first agent, parsing agent, syntactically processes and semantically interprets natural language sentence to construct a fuzzy structured query language (SQL) statement. The second agent, defuzzifying agent, defuzzifies the imprecise part of the fuzzy SQL statement into its equivalent executable precise SQL statement based on fuzzy rules. The first agent can also actively ask the user some necessary questions when it manages to disambiguate the vague retrieval requirements. The adaptive defuzzification approach employed in the defuzzifying agent is discussed in detail. A prototype interface has been implemented to demonstrate the effectiveness.

  5. Environmental Knowledge as Design Development Agent

    Directory of Open Access Journals (Sweden)

    Buthayna Hasan Eilouti

    2012-06-01

    Full Text Available Linking knowledge learnt from nature with concepts of man-made product generation, Biomimetics represents an application of environmental knowledge on engineering design. In this paper, an exploratory approach that is based on the concepts of Biomimetics and their potential transformations into design processing agents is introduced. The approach is tested as a project that applies knowledge inspired by organisms in their natural biomes for the derivation of architectural designs. The project is implemented in a digital architectural design studio in order to model metamorphosis and simulate adaptations of products. The results of the project implementation seem to encourage adopting its associative environmental problem-solving techniques and inter-disciplinary methods as alternatives or complementary to conventional functional- or formal-oriented problem-solving approaches.

  6. An Introduction to Software Agents

    Science.gov (United States)

    2008-02-01

    Tropos .......................................................................................................................... 34 8.3 Gaia...32 DRDC Atlantic TM 2007-221 Each of these methodologies (Prometheus, Tropos and Gaia) guide the user to develop a specification for agents...specific agents required. While Prometheus and Tropos cover similar portions of the overall design process (from requirements to implementation

  7. Agent Based Individual Traffic Guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen

    This thesis investigates the possibilities in applying Operations Research (OR) to autonomous vehicular traffic. The explicit difference to most other research today is that we presume that an agent is present in every vehicle - hence Agent Based Individual Traffic guidance (ABIT). The next...

  8. Topical agents in burn care

    Directory of Open Access Journals (Sweden)

    Momčilović Dragan

    2002-01-01

    Full Text Available Introduction Understanding of fluid shifts and recognition of the importance of early and appropriate fluid replacement therapy have significantly reduced mortality in the early post burn period. After the bum patient successfully passes the resuscitation period, the burn wound represents the greatest threat to survival. History Since the dawn of civilization, man has been trying to find an agent which would help burn wounds heal, and at the same time, not harm general condition of the injured. It was not until the XX century, after the discovery of antibiotics, when this condition was fulfilled. In 1968, combining silver and sulfadiazine, fox made silver-sulfadiazine, which is a 1% hydro-soluble cream and a superior agent in topical treatment of burns today. Current topical agents None of the topical antimicrobial agents available today, alone or combined, have the characteristics of ideal prophylactic agents, but they eliminate colonization of burn wound, and invasive infections are infrequent. With an excellent spectrum of activity, low toxicity, and ease of application with minimal pain, silver-sulfadiazine is still the most frequently used topical agent. Conclusion The incidence of invasive infections and overall mortality have been significantly reduced after introduction of topical burn wound antimicrobial agents into practice. In most burn patients the drug of choice for prophylaxis is silver sulfadiazine. Other agents may be useful in certain clinical situations.

  9. Multimodal nanoparticulate bioimaging contrast agents.

    Science.gov (United States)

    Sharma, Parvesh; Singh, Amit; Brown, Scott C; Bengtsson, Niclas; Walter, Glenn A; Grobmyer, Stephen R; Iwakuma, Nobutaka; Santra, Swadeshmukul; Scott, Edward W; Moudgil, Brij M

    2010-01-01

    A wide variety of bioimaging techniques (e.g., ultrasound, computed X-ray tomography, magnetic resonance imaging (MRI), and positron emission tomography) are commonly employed for clinical diagnostics and scientific research. While all of these methods use a characteristic "energy-matter" interaction to provide specific details about biological processes, each modality differs from another in terms of spatial and temporal resolution, anatomical and molecular details, imaging depth, as well as the desirable material properties of contrast agents needed for augmented imaging. On many occasions, it is advantageous to apply multiple complimentary imaging modalities for faster and more accurate prognosis. Since most imaging modalities employ exogenous contrast agents to improve the signal-to-noise ratio, the development and use of multimodal contrast agents is considered to be highly advantageous for obtaining improved imagery from sought-after imaging modalities. Multimodal contrast agents offer improvements in patient care, and at the same time can reduce costs and enhance safety by limiting the number of contrast agent administrations required for imaging purposes. Herein, we describe the synthesis and characterization of nanoparticulate-based multimodal contrast agent for noninvasive bioimaging using MRI, optical, and photoacoustic tomography (PAT)-imaging modalities. The synthesis of these agents is described using microemulsions, which enable facile integration of the desired diversity of contrast agents and material components into a single entity.

  10. Implementing Lego Agents Using Jason

    CERN Document Server

    Jensen, Andreas Schmidt

    2010-01-01

    Since many of the currently available multi-agent frameworks are generally mostly intended for research, it can be difficult to built multi-agent systems using physical robots. In this report I describe a way to combine the multi-agent framework Jason, an extended version of the agent-oriented programming language AgentSpeak, with Lego robots to address this problem. By extending parts of the Jason reasoning cycle I show how Lego robots are able to complete tasks such as following lines on a floor and communicating to be able to avoid obstacles with minimal amount of coding. The final implementation is a functional extension that is able to built multi-agent systems using Lego agents, however there are some issues that have not been addressed. If the agents are highly dependent on percepts from their sensors, they are required to move quite slowly, because there currently is a high delay in the reasoning cycle, when it is combined with a robot. Overall the system is quite robust and can be used to make simple...

  11. Activity Recognition for Agent Teams

    Science.gov (United States)

    2007-07-01

    seek to use in the upcoming confrontation. There is not a simple mapping between a character capabilities and this policy; an effective team role must...additional research challenges, specific to the team role assumed by the agent. Agents that support individual human team members face the following chal

  12. Pharmacologic Agents for Chronic Diarrhea

    OpenAIRE

    Lee, Kwang Jae

    2015-01-01

    Chronic diarrhea is usually associated with a number of non-infectious causes. When definitive treatment is unavailable, symptomatic drug therapy is indicated. Pharmacologic agents for chronic diarrhea include loperamide, 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists, diosmectite, cholestyramine, probiotics, antispasmodics, rifaximin, and anti-inflammatory agents. Loperamide, a synthetic opiate agonist, decreases peristaltic activity and inhibits secretion, resulting in the reductio...

  13. Consensus in networks of mobile communicating agents

    Science.gov (United States)

    Baronchelli, Andrea; Díaz-Guilera, Albert

    2012-01-01

    Populations of mobile and communicating agents describe a vast array of technological and natural systems, ranging from sensor networks to animal groups. Here, we investigate how a group-level agreement may emerge in the continuously evolving network defined by the local interactions of the moving individuals. We adopt a general scheme of motion in two dimensions and we let the individuals interact through the minimal naming game, a prototypical scheme to investigate social consensus. We distinguish different regimes of convergence determined by the emission range of the agents and by their mobility, and we identify the corresponding scaling behaviors of the consensus time. In the same way, we rationalize also the behavior of the maximum memory used during the convergence process, which determines the minimum cognitive/storage capacity needed by the individuals. Overall, we believe that the simple and general model presented in this paper can represent a helpful reference for a better understanding of the behavior of populations of mobile agents.

  14. Consensus in evolving networks of mobile agents

    Science.gov (United States)

    Baronchelli, Andrea; Díaz-Guilera, Albert

    2012-02-01

    Populations of mobile and communicating agents describe a vast array of technological and natural systems, ranging from sensor networks to animal groups. Here, we investigate how a group-level agreement may emerge in the continuously evolving networks defined by the local interactions of the moving individuals. We adopt a general scheme of motion in two dimensions and we let the individuals interact through the minimal naming game, a prototypical scheme to investigate social consensus. We distinguish different regimes of convergence determined by the emission range of the agents and by their mobility, and we identify the corresponding scaling behaviors of the consensus time. In the same way, we rationalize also the behavior of the maximum memory used during the convergence process, which determines the minimum cognitive/storage capacity needed by the individuals. Overall, we believe that the simple and general model presented in this talk can represent a helpful reference for a better understanding of the behavior of populations of mobile agents.

  15. Multi-Agent Only-Knowing Revisited

    CERN Document Server

    Belle, Vaishak

    2010-01-01

    Levesque introduced the notion of only-knowing to precisely capture the beliefs of a knowledge base. He also showed how only-knowing can be used to formalize non-monotonic behavior within a monotonic logic. Despite its appeal, all attempts to extend only-knowing to the many agent case have undesirable properties. A belief model by Halpern and Lakemeyer, for instance, appeals to proof-theoretic constructs in the semantics and needs to axiomatize validity as part of the logic. It is also not clear how to generalize their ideas to a first-order case. In this paper, we propose a new account of multi-agent only-knowing which, for the first time, has a natural possible-world semantics for a quantified language with equality. We then provide, for the propositional fragment, a sound and complete axiomatization that faithfully lifts Levesque’s proof theory to the many agent case. We also discuss comparisons to the earlier approach by Halpern and Lakemeyer.

  16. Ecological Complexity and the Success of Fungal Biological Control Agents

    Directory of Open Access Journals (Sweden)

    Guy R. Knudsen

    2014-01-01

    Full Text Available Fungal biological control agents against plant pathogens, especially those in soil, operate within physically, biologically, and spatially complex systems by means of a variety of trophic and nontrophic interspecific interactions. However, the biocontrol agents themselves are also subject to the same types of interactions, which may reduce or in some cases enhance their efficacy against target plant pathogens. Characterization of these ecologically complex systems is challenging, but a number of tools are available to help unravel this complexity. Several of these tools are described here, including the use of molecular biology to generate biocontrol agents with useful marker genes and then to quantify these agents in natural systems, epifluorescence and confocal laser scanning microscopy to observe their presence and activity in situ, and spatial statistics and computer simulation modeling to evaluate and predict these activities in heterogeneous soil habitats.

  17. Crowd simulation influenced by agent's socio-psychological state

    CERN Document Server

    Cherif, F

    2010-01-01

    The aim our work is to create virtual humans as intelligent entities, which includes approximate the maximum as possible the virtual agent animation to the natural human behavior. In order to accomplish this task, our agent must be capable to interact with the environment, interacting with objects and other agents. The virtual agent needs to act as real person, so he should be capable to extract semantic information from the geometric model of the world where he is inserted, based on his own perception, and he realizes his own decision. The movement of the individuals is representing by the combination of two approaches of movement which are, the social force model and the based-rule model. These movements are influenced by a set of socio-psychological rules to give a more realistic result.

  18. Chronic immune thrombocytopenic purpura. New agents.

    Science.gov (United States)

    Rodeghiero, F; Ruggeri, M

    2009-01-01

    First generation thrombopoietic growth factors (rhTPO and PEG-rHuMGDF), investigated in the early 2000s, proved effective in increasing platelet count in normal volunteers, in thrombocytopenia due to chemotherapy and also in a few cases of immune thrombocytopenic purpura (ITP). These agents did not complete their clinical development since one of them induced antibodies in the recipients that cross reacted with endogenous thrombopoietin (TPO), thus causing thrombocytopenia. This promoted the ingenious design of a new generation of thrombopoietic growth factors having no sequence homology with natural TPO. The two main agents are romiplostim, a peptibody already approved for clinical use in USA and eltrombopag, a non-peptide, orally active small molecule. In open label and placebo-controlled trials both agents proved to predictably increase platelet count in normal volunteers and in patients with ITP. With appropriate dosages (1-10 microg/kg weekly sub cutaneously for romiplostim; 50-75 mg/die per os for eltrombopag ) a platelet increase becomes significant after 7-10 days and peaks between 10-14 days. By discontinuing treatment, platelet count returns to baseline level in 10-15 days. The response rate with both agents is above 70-80%, also in patients that had undergone several lines of treatment, or that have failed splenectomy. The response is maintained during the treatment, but is almost invariably lost even after several months of successful administration. Due to the lack of a curative potential and to the incomplete knowledge of long-term side effects, the place of these new drugs in the management of ITP is still unsettled and their use is best restricted to refractory patients or in preparation of splenectomy. It seems however that a new paradigm in the treatment of ITP has been established where the focus is not on reducing platelet consumption but on increasing platelet production.

  19. Natural Family Planning

    Science.gov (United States)

    ... Sex and Birth Control Birth Control Natural Family Planning Natural Family Planning Birth ControlPrevention and WellnessSex and Birth Control Share Natural Family Planning Natural Family PlanningWhat is natural family planning?Natural ...

  20. Betacyanins pigments as photosensitizing agents for holographic recording medium

    Science.gov (United States)

    Toxqui-López, S.; Hernández-Hernández, E.; Santacruz-Vázquez, C.; Olivares-Pérez, A.; Santacruz-Vazquez, V.

    2014-02-01

    One of the natural most employed within the food industry are pigments of betalains by their solubility in water to give desired colorations in processed foods such as beverages, dairy, meat. However, this research shows that this type of pigments can be used as photosensitizing agents in the field of holographic recording materials.

  1. Agent-Centered Decision Making in Normal and Abnormal Cognition

    Directory of Open Access Journals (Sweden)

    Goldberg, Elkhonon

    2012-08-01

    Full Text Available Much of human cognition is “agent-centered,” subjective, and in that sense relative, directed at deciding, “What is best for me”. This is very different from “veridical” cognition, directed at finding an objectively correct solution inherent in the task and independent of the agent. The frontal lobes in particular are central to agent-centered decision making. Yet very little is available in the arsenal of cognitive paradigms used in the cognitive neuroscience research and in clinical neuropsychology test design to examine “agent-centered” decision making. Current paradigms and tests used to measure decision making clinically and experimentally are veridical in nature and as such miss the essence of “agent-centered” cognition. The dearth of “agent-centered” cognitive paradigms severely limits our ability to understand fully the function and dysfunction of the frontal lobes. The Cognitive Bias Task (CBT is an agent-centered paradigm designed to fill this gap. CBT has been used as a cognitive activation task in fMRI, SPECT, and EEG, as well as in studies of normal development, addiction, dementia, focal lesions, and schizophrenia. This resulted in a range of findings that eluded more traditional “veridical” paradigms and are reviewed here.

  2. Departments as Agents of Change

    Science.gov (United States)

    Lagowski, J. J.

    1996-07-01

    Higher education is changing because it has no choice. And, for the most part, outside influences are dictating the processes of change. The more fortunate institutions have had a flat budget during this period, but most have been forced to deal with a declining revenue stream as well. Legislators seem bent on micromanaging state-supported institutions, even as they cut their support. Regulators demand greater institutional accountability. Students and their parents expect more service at lower prices and increased flexibility. Technological advances have dramatically affected the availability and accessibility of extant knowledge. It is no longer a question of whether institutions will change, but rather, who will control the change. Most institutions possess long-standing academic traditions, but these are placed at risk in an increasingly competitive market that holds little sympathy for such traditions and may even see them as obstacles or barriers. As a result, the change agents will undoubtedly have a profound effect on the very nature of academic institutions. From the academic point of view, it would seem prudent to attempt to manage the changes that will inevitably occur. A number of concerned observers, notably the Pew Higher Education Roundtable and the American Association for Higher Education, argue persuasively that the academic department is the logical focus for responding to the current winds of change. Using a marketing metaphor, the academic department has been likened to a "producers' cooperative" of services that consumers seek. Thus, the department should be held accountable for the quality of teaching delivered by its members, for the coherence of its major, for its contributions to the general education curriculum, and for supervising and rewarding its individual faculty members. If departments are to be held accountable, it is surely in their best interest to act in such a way that they are accountable. Expecting academic departments to be

  3. Mobile agent driven by aspect

    Directory of Open Access Journals (Sweden)

    Youssef Hannad

    2010-11-01

    Full Text Available Domain application of mobile agents is quite large. They are used for network management and the monitoring of complex architecture. Mobile agent is also essential into specific software architecture such that adaptable grid architecture. Even if the concept of mobile agent seems to be obvious, the development is always complex because it needs to understand network features but also security features and negotiation algorithms. We present a work about an application of aspects dedicated to mobile agent development over a local network. At this level, the underlying protocol is called jini and allows managing several essential concepts such that short transaction and permission management. Three subsets of aspects are defined in this work. A part is for the description of agent host and its security level, accessible resource, etc. A second part is about mobile agent and their collaboration. This means how they can operate on an agent host with the respect of the execution context. All the results are illustrated through a distributed monitoring application called DMA. Its main objective is the observation of component servers.

  4. Natural relaxation

    Science.gov (United States)

    Marzola, Luca; Raidal, Martti

    2016-11-01

    Motivated by natural inflation, we propose a relaxation mechanism consistent with inflationary cosmology that explains the hierarchy between the electroweak scale and Planck scale. This scenario is based on a selection mechanism that identifies the low-scale dynamics as the one that is screened from UV physics. The scenario also predicts the near-criticality and metastability of the Standard Model (SM) vacuum state, explaining the Higgs boson mass observed at the Large Hadron Collider (LHC). Once Majorana right-handed neutrinos are introduced to provide a viable reheating channel, our framework yields a corresponding mass scale that allows for the seesaw mechanism as well as for standard thermal leptogenesis. We argue that considering singlet scalar dark matter extensions of the proposed scenario could solve the vacuum stability problem and discuss how the cosmological constant problem is possibly addressed.

  5. Antibacterial agents in the cinema.

    Science.gov (United States)

    García Sánchez, J E; García Sánchez, E; Merino Marcos, M L

    2006-12-01

    Numerous procedures used as antibacterial therapy are present in many films and include strategies ranging from different antimicrobial drugs to surgery and supporting measures. Films also explore the correct use and misuse of antimicrobial agents. Side effects and other aspects related to antibacterial therapy have also been reflected in some films. This article refers to the presence of antibacterial agents in different popular movies. There are movies in which antibacterial agents form part of the central plot, while in others it is merely an important part of the plot. In still others, its presence is isolated, and in these it plays an ambient or anecdotal role.

  6. Agent Based Multiviews Requirements Model

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on the current researches of viewpoints oriented requirements engineering and intelligent agent, we present the concept of viewpoint agent and its abstract model based on a meta-language for multiviews requirements engineering. It provided a basis for consistency checking and integration of different viewpoint requirements, at the same time, these checking and integration works can automatically realized in virtue of intelligent agent's autonomy, proactiveness and social ability. Finally, we introduce the practical application of the model by the case study of data flow diagram.

  7. The agent-based spatial information semantic grid

    Science.gov (United States)

    Cui, Wei; Zhu, YaQiong; Zhou, Yong; Li, Deren

    2006-10-01

    Analyzing the characteristic of multi-Agent and geographic Ontology, The concept of the Agent-based Spatial Information Semantic Grid (ASISG) is defined and the architecture of the ASISG is advanced. ASISG is composed with Multi-Agents and geographic Ontology. The Multi-Agent Systems are composed with User Agents, General Ontology Agent, Geo-Agents, Broker Agents, Resource Agents, Spatial Data Analysis Agents, Spatial Data Access Agents, Task Execution Agent and Monitor Agent. The architecture of ASISG have three layers, they are the fabric layer, the grid management layer and the application layer. The fabric layer what is composed with Data Access Agent, Resource Agent and Geo-Agent encapsulates the data of spatial information system so that exhibits a conceptual interface for the Grid management layer. The Grid management layer, which is composed with General Ontology Agent, Task Execution Agent and Monitor Agent and Data Analysis Agent, used a hybrid method to manage all resources that were registered in a General Ontology Agent that is described by a General Ontology System. The hybrid method is assembled by resource dissemination and resource discovery. The resource dissemination push resource from Local Ontology Agent to General Ontology Agent and the resource discovery pull resource from the General Ontology Agent to Local Ontology Agents. The Local Ontology Agent is derived from special domain and describes the semantic information of local GIS. The nature of the Local Ontology Agents can be filtrated to construct a virtual organization what could provides a global scheme. The virtual organization lightens the burdens of guests because they need not search information site by site manually. The application layer what is composed with User Agent, Geo-Agent and Task Execution Agent can apply a corresponding interface to a domain user. The functions that ASISG should provide are: 1) It integrates different spatial information systems on the semantic The Grid

  8. Deliberate Evolution in Multi-Agent Systems

    NARCIS (Netherlands)

    Brazier, F.M.T.; Jonker, C.M.; Treur, J.; Wijngaards, N.J.E.

    2000-01-01

    This paper presents an architecture for an agent capable of deliberation about the creation of new agents, and of actually creating a new agent in the multi-agent system, on the basis of this deliberation. The agent architecture is based on an existing

  9. Infectious Agents Trigger Trophic Cascades.

    Science.gov (United States)

    Buck, Julia C; Ripple, William J

    2017-09-01

    Most demonstrated trophic cascades originate with predators, but infectious agents can also cause top-down indirect effects in ecosystems. Here we synthesize the literature on trophic cascades initiated by infectious agents including parasitoids, pathogens, parasitic castrators, macroparasites, and trophically transmitted parasites. Like predators, infectious agents can cause density-mediated and trait-mediated indirect effects through their direct consumptive and nonconsumptive effects respectively. Unlike most predators, however, infectious agents are not fully and immediately lethal to their victims, so their consumptive effects can also trigger trait-mediated indirect effects. We find that the frequency of trophic cascades reported for different consumer types scales with consumer lethality. Furthermore, we emphasize the value of uniting predator-prey and parasite-host theory under a general consumer-resource framework. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Bacteriocins as Potential Anticancer Agents

    National Research Council Canada - National Science Library

    Kaur, Sumanpreet; Kaur, Sukhraj

    2015-01-01

    .... Thus, the demand for novel anti-cancer agents is increasing day by day. Some of the experimental studies have reported the therapeutic potential of bacteriocins against various types of cancer cell lines...

  11. Business Intelligence using Software Agents

    OpenAIRE

    Ana-Ramona BOLOGA; Razvan BOLOGA

    2011-01-01

    This paper presents some ideas about business intelligence today and the importance of developing real time business solutions. The authors make an exploration of links between business intelligence and artificial intelligence and focuses specifically on the implementation of software agents-based systems in business intelligence. There are briefly presented some of the few solutions proposed so far that use software agents properties for the benefit of business intelligence. The authors then...

  12. Humor and embodied conversational agents

    OpenAIRE

    Nijholt, A.

    2003-01-01

    This report surveys the role of humor in human-to-human interaction and the possible role of humor in human-computer interaction. The aim is to see whether it is useful for embodied conversational agents to integrate humor capabilities in their internal model of intelligence, emotions and interaction (verbal and nonverbal) capabilities. A current state of the art of research in embodied conversational agents, affective computing and verbal and nonverbal interaction is presented. The report ad...

  13. Antimicrobials for bacterial bioterrorism agents.

    Science.gov (United States)

    Sarkar-Tyson, Mitali; Atkins, Helen S

    2011-06-01

    The limitations of current antimicrobials for highly virulent pathogens considered as potential bioterrorism agents drives the requirement for new antimicrobials that are suitable for use in populations in the event of a deliberate release. Strategies targeting bacterial virulence offer the potential for new countermeasures to combat bacterial bioterrorism agents, including those active against a broad spectrum of pathogens. Although early in the development of antivirulence approaches, inhibitors of bacterial type III secretion systems and cell division mechanisms show promise for the future.

  14. Business Intelligence using Software Agents

    OpenAIRE

    Ana-Ramona BOLOGA; Razvan BOLOGA

    2011-01-01

    This paper presents some ideas about business intelligence today and the importance of developing real time business solutions. The authors make an exploration of links between business intelligence and artificial intelligence and focuses specifically on the implementation of software agents-based systems in business intelligence. There are briefly presented some of the few solutions proposed so far that use software agents properties for the benefit of business intelligence. The authors then...

  15. What makes virtual agents believable?

    Science.gov (United States)

    Bogdanovych, Anton; Trescak, Tomas; Simoff, Simeon

    2016-01-01

    In this paper we investigate the concept of believability and make an attempt to isolate individual characteristics (features) that contribute to making virtual characters believable. As the result of this investigation we have produced a formalisation of believability and based on this formalisation built a computational framework focused on simulation of believable virtual agents that possess the identified features. In order to test whether the identified features are, in fact, responsible for agents being perceived as more believable, we have conducted a user study. In this study we tested user reactions towards the virtual characters that were created for a simulation of aboriginal inhabitants of a particular area of Sydney, Australia in 1770 A.D. The participants of our user study were exposed to short simulated scenes, in which virtual agents performed some behaviour in two different ways (while possessing a certain aspect of believability vs. not possessing it). The results of the study indicate that virtual agents that appear resource bounded, are aware of their environment, own interaction capabilities and their state in the world, agents that can adapt to changes in the environment and exist in correct social context are those that are being perceived as more believable. Further in the paper we discuss these and other believability features and provide a quantitative analysis of the level of contribution for each such feature to the overall perceived believability of a virtual agent.

  16. Glutamic acid as anticancer agent: An overview

    National Research Council Canada - National Science Library

    Dutta, Satyajit; Ray, Supratim; Nagarajan, K

    2013-01-01

    The objective of the article is to highlight various roles of glutamic acid like endogenic anticancer agent, conjugates to anticancer agents, and derivatives of glutamic acid as possible anticancer agents...

  17. heavy metal fixation in contaminated soil using non-toxic agents

    African Journals Online (AJOL)

    USER

    2013-05-08

    May 8, 2013 ... The effectiveness of natural clay, calcium phosphate, poultry manure and rice husks as ... BCR extractions showed that the agents attenuated Cu and Pb mobilities ... metal contamination of soil may pose risks and hazards.

  18. Cautiously using natural medicine to treat liver problems.

    Science.gov (United States)

    Xiong, Fei; Guan, Yong-Song

    2017-05-21

    Natural medicine is a system of therapy that administrates natural agents and their derivatives to treat human diseases. This medicine has been used to treat many kinds of human diseases for thousands of years. The treatment protocols of natural medicine are integrative in nature, and are required to utilize the most appropriate therapies to address the needs of the individual patient. Because of the relative convenience, safety and efficacy, natural medicine is now increasing worldwide. Naturopathic doctors are licensed in many areas of the world and regulated partly by law in these areas, which is quite different from various other forms of complementary and alternative medicine. Liver diseases, such as hepatitis, liver cirrhosis and liver carcinoma, are serious health problems worldwide. Nearly half of the natural agents used in treatment of liver diseases today are natural products and their derivatives. Although natural medicine is beneficial and safe, physicians should pay close attention to the potential side-effects of the naturopathic agents, which lead to liver injury, interstitial pneumonia and acute respiratory failure. Therefore, when administrating naturopathic protocols to patients for the treatment of liver diseases, we should try our best to prevent and avoid as much as possible the negative impact of these medicines. This article highlights the current practice and recommended improvement of natural medicines in the treatment of liver diseases and gives some specific examples to emphasize the prevention and management of adverse reactions of the natural agents and suggests that natural medicine should be cautiously used to treat liver problems.

  19. Geo-Agents: Design and Implement

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Geo-Agents, a multi-agent system that processes distr ib utedgeospatial information and geospatial service was presented. Firstly, the requirement for distributed geographical information process was discussed, and the architecture of Geo-Agents was introduced. Then in-depth discussions were r aised on agent system implementation, such as the basic agent, agent advertising , message passing, and collaborating. An example was also given to explain the p roblem solving process.

  20. Colitis associated with biological agents

    Institute of Scientific and Technical Information of China (English)

    Hugh James Freeman

    2012-01-01

    In the past,there has been considerable focus on a host of drugs and chemicals that may produce colonic toxicity.Now,a variety of new biological monoclonal antibody agents,usually administered by infusion,have appeared in the clinical realm over the last decade or so to treat different chronic inflammatory or malignant disorders.For some of these agents,adverse effects have been documented,including apparently new forms of immune-mediated inflammatory bowel disease.In some,only limited symptoms have been recorded,but in others,severe colitis with serious complications,such as bowel perforation has been recorded.In others,adverse effects may have a direct vascular or ischemic basis,while other intestinal effects may be related to a superimposed infection.Some new onset cases of ulcerative colitis or Crohn's disease may also be attributed to the same agents used to treat these diseases,or be responsible for disease exacerbation.Dramatic and well documented side effects have been observed with ipilimumab,a humanized monoclonal antibody developed to reduce and overcome cytotoxic T-lymphocyte antigen 4,a key negative feedback regulator of the T-cell anti-tumor response.This agent has frequently been used in the treatment of different malignancies,notably,malignant melanoma.Side effects with this agent occur in up to 40% and these are believed to be largely immune-mediated.One of these is a form of enterocolitis that may be severe,and occasionally,fatal.Other agents include rituximab (an antiCD20 monoclonal antibody),bevacizumab (a monoclonal antibody against the vascular endothelial growth factor) and anti-tumor necrosis factor agents,including infliximab,adalimumab and etanercept.

  1. Strategic evolution of petroleum agents in Latin America; Evolucao estrategica dos agentes petroliferos na America Latina

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Alexandre de Figueiredo [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Planejamento Energetico]. E-mail: freire@ppe.ufrj.br

    1999-07-01

    This paper analyses the strategies of the Latin-American agents PDVSA, PEMEX, YPF and Ecopetrol face to the double transformation: global re-structuration and deregulation of the national industries. The study focuses the traditional sectors of the petroleum industries (core business), including the petrochemical industries and new segments such as natural gas and electric power. The paper analyses the period 1992-1996, which is characterized by price instability, liberalization of the Latin-American markets and in the corporation-enterprise plane by successive mergings and acquisitions modifying the actors strategic behaviour.

  2. ACO Agent Based Routing in AOMDV Environment

    Directory of Open Access Journals (Sweden)

    Kaur Amanpreet

    2016-01-01

    Full Text Available Mobile Ad-hoc Network (MANET is a group of moving nodes which can communicate with each other without the help of any central stationary node. All the nodes in the MANET act as router for forwarding data packets. The nodes in the network also move randomly and there exists no fixed infrastructure. So, path breaks are the frequent problem in MANET. The routing protocol faces a lot of problem due these path breaks. Therefore, the routing protocol which is multipath in nature is more reliable than a unipath routing protocol. Ant colony optimization is a relatively new technique which is suitable for the optimization problems. AOMDV is a multipath routing protocol. Thus, if there happens to be path break, the packets can start following the new path which has already been selected. In this paper, we are trying to add ant’s agents into AOMDV behavior. In this way, the new protocol will be benefited by the dual properties i.e. of ant’s nature and multipath nature of AOMDV. The modified concept is simulated and the outcomes are compared with AOMDV, AODV and DSR routing protocols for few performance parameters. Results obtained are encouraging; the new algorithm performs better than traditional unipath and multipath routing protocols.

  3. Agents that act luminally to treat diarrhoea and constipation.

    Science.gov (United States)

    Menees, Stacy; Saad, Richard; Chey, William D

    2012-11-01

    Diarrhoea and constipation are common clinical complaints that negatively affect quality of life, reduce work productivity and lead to considerable health-care expenditure. A variety of therapies have been used to treat these conditions. Unlike drugs that require systemic absorption to exert their effects, luminally acting agents improve diarrhoea and constipation by altering intestinal and/or colonic motility, as well as mucosal absorption and secretion, through a variety of mechanisms. Examples of luminally acting agents for diarrhoea include peripherally acting opiate analogues, enkephalinase inhibitors, bile-acid binding agents, nonabsorbed antibiotics, probiotics, bismuth-containing compounds, berberine and agents with possible effects on intestinal secretion or permeability. Luminally acting drugs for constipation include bulking agents, surfactants, osmotics, stimulants, chloride-channel activators, probiotics, drugs that increase delivery of bile acids to the colon and natural therapies such as prunes and hemp seed extract. As the physiological effects of luminally acting drugs are largely confined to the gastrointestinal tract, these agents are unlikely to cause adverse effects outside of the gastrointestinal tract.

  4. A multi-agent architecture for geosimulation of moving agents

    Science.gov (United States)

    Vahidnia, Mohammad H.; Alesheikh, Ali A.; Alavipanah, Seyed Kazem

    2015-10-01

    In this paper, a novel architecture is proposed in which an axiomatic derivation system in the form of first-order logic facilitates declarative explanation and spatial reasoning. Simulation of environmental perception and interaction between autonomous agents is designed with a geographic belief-desire-intention and a request-inform-query model. The architecture has a complementary quantitative component that supports collaborative planning based on the concept of equilibrium and game theory. This new architecture presents a departure from current best practices geographic agent-based modelling. Implementation tasks are discussed in some detail, as well as scenarios for fleet management and disaster management.

  5. Complex groundwater flow systems as traveling agent models

    CERN Document Server

    López-Corona, Oliver; Escolero, Oscar; González, Tomás; Morales-Casique, Eric

    2014-01-01

    Analyzing field data from pumping tests, we show that as with many other natural phenomena, groundwater flow exhibits a complex dynamics described by 1/f power spectrum. This result is theoretically studied within an agent perspective. Using a traveling agent model, we prove that this statistical behavior emerges when the medium is complex. Some heuristic reasoning is provided to justify both spatial and dynamic complexity, as the result of the superposition of an infinite number of stochastic processes. Even more, we show that this implies that non-Kolmogorovian probability is needed for its study, and provide a set of new partial differential equations for groundwater flow.

  6. The Agent of extracting Internet Information with Lead Order

    Science.gov (United States)

    Mo, Zan; Huang, Chuliang; Liu, Aijun

    In order to carry out e-commerce better, advanced technologies to access business information are in need urgently. An agent is described to deal with the problems of extracting internet information that caused by the non-standard and skimble-scamble structure of Chinese websites. The agent designed includes three modules which respond to the process of extracting information separately. A method of HTTP tree and a kind of Lead algorithm is proposed to generate a lead order, with which the required web can be retrieved easily. How to transform the extracted information structuralized with natural language is also discussed.

  7. Nature and nature values in organic agriculture

    DEFF Research Database (Denmark)

    Hansen, Lene; Noe, Egon; Højring, Katrine

    2006-01-01

    The relationship between agriculture and nature is a centra issue in the current agricultural debate. Organic farming has ambitions and a special potential in relation to nature. Consideration for nature is part of the guiding principals of organic farming and many organic farmers are committed...... to protecting natural qualities. However, the issue of nature, landscape, and land use is not straightforward. Nature is an ambiguous concept that involves multiple interests and actors reaching far beyond farmers. The Danish research project ......

  8. SPECIFIC SEQUESTERING AGENTS FOR THE ACTINIDES

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, Kenneth N.; Smith, William L.; Weitl, Frederick L.; Durbin, Patricia W.; Jones, E.Sarah; Abu-Dari, Kamal; Sofen, Stephen R.; Cooper, Stephen R.

    1979-09-01

    This paper summarizes the current status of a continuing project directed toward the synthesis and characterization of chelating agents which are specific for actinide ions - especially Pu(IV) - using a biomimetic approach that relies on the observation that Pu(IV) and Fe(III) has marked similarities that include their biological transport and distribution in mammals. Since the naturally-occurring Fe(III) sequestering agents produced by microbes commonly contain hydroxamate and catecholate functional groups, these groups should complex the actinides very strongly and macrocyclic ligands incorporating these moieties are being prepared. We have reported the isolation and structure analysis of an isostructural series of tetrakis(catecholato) complexes with the general stoichiometry Na{sub 4}[M(C{sub 6}H{sub 4}O{sub 2}){sub 4}] • 21 H{sub 2}O (M = Th, U, Ce, Hf). These complexes are structural archetypes for the cavity that must be formed if an actinide-specific sequestering agent is to conform ideally to the coordination requirements of the central metal ion. The [M(cat){sub 4}]{sup 4-} complexes have the D{sub 2d} symmetry of the trigonal-faced dodecahedron.. The complexes Th [R'C(0)N(O)R]{sub 4} have been prepared where R = isopropyl and R' = t-butyl or neopentyl. The neopentyl derivative is also relatively close to an idealized D{sub 2d} dodecahedron, while the sterically more hindered t-butyl compound is distorted toward a cubic geometry. The synthesis of a series of 2, 3-dihydroxy-benzoyl amide derivatives of linear and cyclic tetraaza- and diazaalkanes is reported. Sulfonation of these compounds improves the metal complexation and in vivo removal of plutonium from test animals. These results substantially exceed the capabilities of compounds presently used for the therapeutic treatment of actinide contamination.

  9. Leveraging synergy for multiple agent infotaxis

    Energy Technology Data Exchange (ETDEWEB)

    Gintautas, Vadas [Los Alamos National Laboratory; Hagberg, Aric A [Los Alamos National Laboratory; Bettencourt, Luis M A [Los Alamos National Laboratory

    2008-01-01

    Social computation, whether in the form of a search performed by a swarm of agents or the predictions of markets, often supplies remarkably good solutions to complex problems, which often elude the best experts. There is an intuition, built upon many anecdotal examples, that pervading principles are at play that allow individuals trying to solve a problem locally to aggregate their information to arrive at an outcome superior than any available to isolated parties. Here we show that the general structure of this problem can be cast in terms of information theory and derive general mathematical conditions for information sharing and coordination that lead to optimal multi-agent searches. Specifically we illustrate the problem in terms of the construction of local search algorithms for autonomous agents looking for the spatial location of a stochastic source. We explore the types of search problems -defined in terms of the properties of the source and the nature of measurements at each sensor -for which coordination among multiple searchers yields an advantage beyond that gained by having the same number of independent searchers. We assert that effective coordination corresponds to synergy and that ineffective coordination corresponds to redundancy as defined using information theory. We classify explicit types of sources in terms of their potential for synergy. We show that sources that emit uncorrelated particles based on a Poisson process, provide no opportunity for synergetic coordination while others, particularly sources that emit correlated signals, do allow for strong synergy between searchers. These general considerations are crucial for designing optimal algorithms for particular search problems in real world settings.

  10. Therapeutic potential of chalcones as cardiovascular agents.

    Science.gov (United States)

    Mahapatra, Debarshi Kar; Bharti, Sanjay Kumar

    2016-03-01

    Cardiovascular diseases are the leading cause of death affecting 17.3 million people across the globe and are estimated to affect 23.3 million people by year 2030. In recent years, about 7.3 million people died due to coronary heart disease, 9.4 million deaths due to high blood pressure and 6.2 million due to stroke, where obesity and atherosclerotic progression remain the chief pathological factors. The search for newer and better cardiovascular agents is the foremost need to manage cardiac patient population across the world. Several natural and (semi) synthetic chalcones deserve the credit of being potential candidates to inhibit various cardiovascular, hematological and anti-obesity targets like angiotensin converting enzyme (ACE), cholesteryl ester transfer protein (CETP), diacylglycerol acyltransferase (DGAT), acyl-coenzyme A: cholesterol acyltransferase (ACAT), pancreatic lipase (PL), lipoprotein lipase (LPL), calcium (Ca(2+))/potassium (K(+)) channel, COX-1, TXA2 and TXB2. In this review, a comprehensive study of chalcones, their therapeutic targets, structure activity relationships (SARs), mechanisms of actions (MOAs) have been discussed. Chemically diverse chalcone scaffolds, their derivatives including structural manipulation of both aryl rings, replacement with heteroaryl scaffold(s) and hybridization through conjugation with other pharmacologically active scaffold have been highlighted. Chalcones which showed promising activity and have a well-defined MOAs, SARs must be considered as prototype for the design and development of potential anti-hypertensive, anti-anginal, anti-arrhythmic and cardioprotective agents. With the knowledge of these molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective chalcone derivatives as potential cardiovascular agents.

  11. Evaluating Water Demand Using Agent-Based Modeling

    Science.gov (United States)

    Lowry, T. S.

    2004-12-01

    The supply and demand of water resources are functions of complex, inter-related systems including hydrology, climate, demographics, economics, and policy. To assess the safety and sustainability of water resources, planners often rely on complex numerical models that relate some or all of these systems using mathematical abstractions. The accuracy of these models relies on how well the abstractions capture the true nature of the systems interactions. Typically, these abstractions are based on analyses of observations and/or experiments that account only for the statistical mean behavior of each system. This limits the approach in two important ways: 1) It cannot capture cross-system disruptive events, such as major drought, significant policy change, or terrorist attack, and 2) it cannot resolve sub-system level responses. To overcome these limitations, we are developing an agent-based water resources model that includes the systems of hydrology, climate, demographics, economics, and policy, to examine water demand during normal and extraordinary conditions. Agent-based modeling (ABM) develops functional relationships between systems by modeling the interaction between individuals (agents), who behave according to a probabilistic set of rules. ABM is a "bottom-up" modeling approach in that it defines macro-system behavior by modeling the micro-behavior of individual agents. While each agent's behavior is often simple and predictable, the aggregate behavior of all agents in each system can be complex, unpredictable, and different than behaviors observed in mean-behavior models. Furthermore, the ABM approach creates a virtual laboratory where the effects of policy changes and/or extraordinary events can be simulated. Our model, which is based on the demographics and hydrology of the Middle Rio Grande Basin in the state of New Mexico, includes agent groups of residential, agricultural, and industrial users. Each agent within each group determines its water usage

  12. The Nature of the Bioterrorism Threat

    Energy Technology Data Exchange (ETDEWEB)

    Regens, J. L.

    2003-02-25

    This analysis provides an overview of the nature of the bioterrorism threat. It identifies potential CDC Class A biological agents that are likely candidates for use in a terrorist incident and describes the known sources of vulnerability. The paper also summarizes S&T resources/needs and assesses response options for achieving effective biodefense against terrorist threats.

  13. Agent review phase one report.

    Energy Technology Data Exchange (ETDEWEB)

    Zubelewicz, Alex Tadeusz; Davis, Christopher Edward; Bauer, Travis LaDell

    2009-12-01

    This report summarizes the findings for phase one of the agent review and discusses the review methods and results. The phase one review identified a short list of agent systems that would prove most useful in the service architecture of an information management, analysis, and retrieval system. Reviewers evaluated open-source and commercial multi-agent systems and scored them based upon viability, uniqueness, ease of development, ease of deployment, and ease of integration with other products. Based on these criteria, reviewers identified the ten most appropriate systems. The report also mentions several systems that reviewers deemed noteworthy for the ideas they implement, even if those systems are not the best choices for information management purposes.

  14. Dopamine agents for hepatic encephalopathy

    DEFF Research Database (Denmark)

    Junker, Anders Ellekær; Als-Nielsen, Bodil; Gluud, Christian

    2014-01-01

    BACKGROUND: Patients with hepatic encephalopathy may present with extrapyramidal symptoms and changes in basal ganglia. These changes are similar to those seen in patients with Parkinson's disease. Dopamine agents (such as bromocriptine and levodopa, used for patients with Parkinson's disease) have...... therefore been assessed as a potential treatment for patients with hepatic encephalopathy. OBJECTIVES: To evaluate the beneficial and harmful effects of dopamine agents versus placebo or no intervention for patients with hepatic encephalopathy. SEARCH METHODS: Trials were identified through the Cochrane...... of the trials followed participants after the end of treatment. Only one trial reported adequate bias control; the remaining four trials were considered to have high risk of bias. Random-effects model meta-analyses showed that dopamine agents had no beneficial or detrimental effect on hepatic encephalopathy...

  15. [Anti-influenza virus agent].

    Science.gov (United States)

    Nakamura, Shigeki; Kohno, Shigeru

    2012-04-01

    The necessity of newly anti-influenza agents is increasing rapidly after the prevalence of pandemic influenza A (H1N1) 2009. In addition to the existing anti-influenza drugs, novel neuraminidase inhibitors such as peramivir (a first intravenous anti-influenza agent) and laninamivir (long acting inhaled anti-influenza agent) can be available. Moreover favipiravir, which shows a novel anti-influenza mechanism acting as RNA polymerase inhibitor, has been developing. These drugs are expected to improve the prognosis of severe cases caused by not only seasonal influenza but pandemic influenza A (H1N1) 2009 virus and H5N1 avian influenza, and also treat oseltamivir-resistant influenza effectively.

  16. Dual Rationality and Deliberative Agents

    Science.gov (United States)

    Debenham, John; Sierra, Carles

    Human agents deliberate using models based on reason for only a minute proportion of the decisions that they make. In stark contrast, the deliberation of artificial agents is heavily dominated by formal models based on reason such as game theory, decision theory and logic—despite that fact that formal reasoning will not necessarily lead to superior real-world decisions. Further the Nobel Laureate Friedrich Hayek warns us of the ‘fatal conceit’ in controlling deliberative systems using models based on reason as the particular model chosen will then shape the system’s future and either impede, or eventually destroy, the subtle evolutionary processes that are an integral part of human systems and institutions, and are crucial to their evolution and long-term survival. We describe an architecture for artificial agents that is founded on Hayek’s two rationalities and supports the two forms of deliberation used by mankind.

  17. Relational agents in clinical psychiatry.

    Science.gov (United States)

    Bickmore, Timothy; Gruber, Amanda

    2010-01-01

    Relational agents are computational artifacts, such as animated, screen-based characters or social robots, that are designed to establish a sense of rapport, trust, and even therapeutic alliance with patients, using ideal therapeutic relationships between human counselors and patients as role models. We describe the development and evaluation of several such agents designed for health counseling and behavioral-change interventions, in which a therapeutic alliance is established with patients in order to enhance the efficacy of the intervention. We also discuss the promise of using such agents as adjuncts to clinical psychiatry, a range of possible applications, and some of the challenges and ethical issues in developing and fielding them in psychiatric interventions.

  18. Software Agents in Data and Workflow Management

    CERN Document Server

    Barrass, T A; Metson, S; Newbold, D; Jank, W; García-Abia, P; Hernández, J M; Afaq, A; Ernst, M; Fisk, I; Wu, Y; Charlot, C; Semeniouk, I N; Bonacorsi, D; Fanfani, A; Grandi, C; De Filippis, N; Rabbertz, K; Rehn, J; Tuura, L; Wildish, T; Newbold, D

    2005-01-01

    CMS currently uses a number of tools to transfer data which, taken together, form the basis of a heterogeneous datagrid. The range of tools used, and the directed, rather than optimized nature of CMS recent large scale data challenge required the creation of a simple infrastructure that allowed a range of tools to operate in a complementary way. The system created comprises a hierarchy of simple processes (named agents) that propagate files through a number of transfer states. File locations and some application metadata were stored in POOL file catalogues, with LCG LRC or MySQL back-ends. Agents were assigned limited responsibilities, and were restricted to communicating state 9in a well-defined, indirect fashion through a central transfer management database. In this way, the task of distributing data was easily divided between different groups for implementation. The prototype system w as developed rapidly, and achieved the required sustained transfer rate of ~10 MBps, with O(10^6) files distributed to 6 s...

  19. Probiotics as Antiviral Agents in Shrimp Aquaculture

    Directory of Open Access Journals (Sweden)

    Bestha Lakshmi

    2013-01-01

    Full Text Available Shrimp farming is an aquaculture business for the cultivation of marine shrimps or prawns for human consumption and is now considered as a major economic and food production sector as it is an increasingly important source of protein available for human consumption. Intensification of shrimp farming had led to the development of a number of diseases, which resulted in the excessive use of antimicrobial agents, which is finally responsible for many adverse effects. Currently, probiotics are chosen as the best alternatives to these antimicrobial agents and they act as natural immune enhancers, which provoke the disease resistance in shrimp farm. Viral diseases stand as the major constraint causing an enormous loss in the production in shrimp farms. Probiotics besides being beneficial bacteria also possess antiviral activity. Exploitation of these probiotics in treatment and prevention of viral diseases in shrimp aquaculture is a novel and efficient method. This review discusses the benefits of probiotics and their criteria for selection in shrimp aquaculture and their role in immune power enhancement towards viral diseases.

  20. Probiotics as antiviral agents in shrimp aquaculture.

    Science.gov (United States)

    Lakshmi, Bestha; Viswanath, Buddolla; Sai Gopal, D V R

    2013-01-01

    Shrimp farming is an aquaculture business for the cultivation of marine shrimps or prawns for human consumption and is now considered as a major economic and food production sector as it is an increasingly important source of protein available for human consumption. Intensification of shrimp farming had led to the development of a number of diseases, which resulted in the excessive use of antimicrobial agents, which is finally responsible for many adverse effects. Currently, probiotics are chosen as the best alternatives to these antimicrobial agents and they act as natural immune enhancers, which provoke the disease resistance in shrimp farm. Viral diseases stand as the major constraint causing an enormous loss in the production in shrimp farms. Probiotics besides being beneficial bacteria also possess antiviral activity. Exploitation of these probiotics in treatment and prevention of viral diseases in shrimp aquaculture is a novel and efficient method. This review discusses the benefits of probiotics and their criteria for selection in shrimp aquaculture and their role in immune power enhancement towards viral diseases.

  1. Beneficial and adverse effects of chemopreventive agents

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Mu; Park, Kwang-Kyun

    2003-03-01

    The beneficial and adverse effects of some chemopreventive agents, such as Vitamins A, C, E, beta-carotene, indole-3-carbinol, capsaicin, garlic, and aloe are reviewed. Two large randomized trials with a lung cancer endpoint, the Alpha-Tocopherol, Beta-Carotene (ATBC) Prevention Study and the Beta-Carotene and Retinol Efficacy Trial (CARET), suggested that antioxidants might be harmful in smokers. However, the results of the Linxian study and of the ATBC or the CARET studies were significantly different in this respect, and therefore, the relationship between antioxidant and carcinogenesis remains open to debate. Indole-3-carbinol has cancer promoting activities in the colon, thyroid, pancreas, and liver, whereas capsaicin alters the metabolism of chemical carcinogens and may promote carcinogenesis at high doses. Organosulfur compounds and selenium from garlic have no or a little enhancing effect on cancer promotion stage. Information upon chemopreventive mechanisms that inhibit carcinogenesis is imperfect, although the causes and natures of certain human cancers are known. Therefore, definitive preventive guidelines should be carefully offered for various types of tumors, which properly consider ethnic variations, and the efficacies and the safety of chemopreventive agents.

  2. Rodents as potential couriers for bioterrorism agents.

    Science.gov (United States)

    Lõhmus, Mare; Janse, Ingmar; van de Goot, Frank; van Rotterdam, Bart J

    2013-09-01

    Many pathogens that can cause major public health, economic, and social damage are relatively easily accessible and could be used as biological weapons. Wildlife is a natural reservoir for many potential bioterrorism agents, and, as history has shown, eliminating a pathogen that has dispersed among wild fauna can be extremely challenging. Since a number of wild rodent species live close to humans, rodents constitute a vector for pathogens to circulate among wildlife, domestic animals, and humans. This article reviews the possible consequences of a deliberate spread of rodentborne pathogens. It is relatively easy to infect wild rodents with certain pathogens or to release infected rodents, and the action would be difficult to trace. Rodents can also function as reservoirs for diseases that have been spread during a bioterrorism attack and cause recurring disease outbreaks. As rats and mice are common in both urban and rural settlements, deliberately released rodentborne infections have the capacity to spread very rapidly. The majority of pathogens that are listed as potential agents of bioterrorism by the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases exploit rodents as vectors or reservoirs. In addition to zoonotic diseases, deliberately released rodentborne epizootics can have serious economic consequences for society, for example, in the area of international trade restrictions. The ability to rapidly detect introduced diseases and effectively communicate with the public in crisis situations enables a quick response and is essential for successful and cost-effective disease control.

  3. Agent-based modelling in synthetic biology.

    Science.gov (United States)

    Gorochowski, Thomas E

    2016-11-30

    Biological systems exhibit complex behaviours that emerge at many different levels of organization. These span the regulation of gene expression within single cells to the use of quorum sensing to co-ordinate the action of entire bacterial colonies. Synthetic biology aims to make the engineering of biology easier, offering an opportunity to control natural systems and develop new synthetic systems with useful prescribed behaviours. However, in many cases, it is not understood how individual cells should be programmed to ensure the emergence of a required collective behaviour. Agent-based modelling aims to tackle this problem, offering a framework in which to simulate such systems and explore cellular design rules. In this article, I review the use of agent-based models in synthetic biology, outline the available computational tools, and provide details on recently engineered biological systems that are amenable to this approach. I further highlight the challenges facing this methodology and some of the potential future directions. © 2016 The Author(s).

  4. Quorum Quenching Agents: Resources for Antivirulence Therapy

    Directory of Open Access Journals (Sweden)

    Kaihao Tang

    2014-05-01

    Full Text Available The continuing emergence of antibiotic-resistant pathogens is a concern to human health and highlights the urgent need for the development of alternative therapeutic strategies. Quorum sensing (QS regulates virulence in many bacterial pathogens, and thus, is a promising target for antivirulence therapy which may inhibit virulence instead of cell growth and division. This means that there is little selective pressure for the evolution of resistance. Many natural quorum quenching (QQ agents have been identified. Moreover, it has been shown that many microorganisms are capable of producing small molecular QS inhibitors and/or macromolecular QQ enzymes, which could be regarded as a strategy for bacteria to gain benefits in competitive environments. More than 30 species of marine QQ bacteria have been identified thus far, but only a few of them have been intensively studied. Recent studies indicate that an enormous number of QQ microorganisms are undiscovered in the highly diverse marine environments, and these marine microorganism-derived QQ agents may be valuable resources for antivirulence therapy.

  5. Designed TPR Modules as Novel Anticancer Agents

    Energy Technology Data Exchange (ETDEWEB)

    Cortajarena,A.; Yi, F.; Regan, L.

    2008-01-01

    Molecules specifically designed to modulate protein-protein interactions have tremendous potential as novel therapeutic agents. One important anticancer target is the chaperone Hsp90, whose activity is essential for the folding of many oncogenic proteins, including HER2, IGFIR, AKT, RAF-1, and FLT-3. Here we report the design and characterization of new tetratricopeptide repeat modules, which bind to the C-terminus of Hsp90 with higher affinity and with greater specificity than natural Hsp90-binding co-chaperones. Thus, when these modules are introduced into the cell, they out-compete endogenous co-chaperones for binding, thereby inhibiting Hsp90 function. The effect of Hsp90 inhibition in this fashion is dramatic; HER2 levels are substantially decreased and BT474 HER2 positive breast cancer cells are killed. Our designs thus provide new tools with which to dissect the mechanism of Hsp90-mediated protein folding and also open the door to the development of an entirely new class of anticancer agents.

  6. Agent-based modeling in ecological economics.

    Science.gov (United States)

    Heckbert, Scott; Baynes, Tim; Reeson, Andrew

    2010-01-01

    Interconnected social and environmental systems are the domain of ecological economics, and models can be used to explore feedbacks and adaptations inherent in these systems. Agent-based modeling (ABM) represents autonomous entities, each with dynamic behavior and heterogeneous characteristics. Agents interact with each other and their environment, resulting in emergent outcomes at the macroscale that can be used to quantitatively analyze complex systems. ABM is contributing to research questions in ecological economics in the areas of natural resource management and land-use change, urban systems modeling, market dynamics, changes in consumer attitudes, innovation, and diffusion of technology and management practices, commons dilemmas and self-governance, and psychological aspects to human decision making and behavior change. Frontiers for ABM research in ecological economics involve advancing the empirical calibration and validation of models through mixed methods, including surveys, interviews, participatory modeling, and, notably, experimental economics to test specific decision-making hypotheses. Linking ABM with other modeling techniques at the level of emergent properties will further advance efforts to understand dynamics of social-environmental systems.

  7. Antimycobacterial agents from selected Mexican medicinal plants.

    Science.gov (United States)

    Rivero-Cruz, Isabel; Acevedo, Laura; Guerrero, José A; Martínez, Sergio; Bye, Robert; Pereda-Miranda, Rogelio; Franzblau, Scott; Timmermann, Barbara N; Mata, Rachel

    2005-09-01

    As part of the ICBG program Bioactive Agents from Dryland Biodiversity of Latin America, the present investigation was undertaken to explore the possible antimycobacterial potential of compounds derived from selected Mexican medicinal plants. Bioassay-guided fractionation of the crude extracts of Rumex hymenosepalus (Polygonaceae), Larrea divaricata (Zygophyllaceae), Phoradendron robinsonii (Loranthaceae) and Amphipteryngium adstringens (Julianiaceae) led to the isolation of several antimycobacterial compounds. Four stilbenoids, two flavan-3-ols and three anthraquinones were isolated from R. hymenosepalus. Two flavonols and nordihydroguaiaretic acid were obtained from L. divaricata. Sakuranetin was the antimycobacterial agent isolated from P. robinsonii. Two known triterpenoids and the novel natural product 3-dodecyl-1,8-dihydroxy-2-naphthoic acid were obtained from A. adstringens. In general, the isolates were identified by spectral means. The antimycobacterial activity of the secondary compounds isolated from the analysed species, as well as that of nine pure compounds previously isolated in our laboratories, was investigated; the MIC values ranged from 16 to 128 microg mL-1. Among the tested compounds, the glycolipids, sesquiterpenoids and triterpenoids showed the best antimycobacterial activity. The antimycobacterial property of the glycolipids is reported for the first time. Although the tested compounds showed moderate antimycobacterial activity, their presence in the analysed species provides the rationale for their traditional use in the treatment of tuberculosis.

  8. Bitrex: A new levelling agent for copper

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, J.F.K., E-mail: J.F.K.Cooper@gmail.com [Department of Physics, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Barnes, C.H.W. [Department of Physics, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

    2011-10-30

    Highlights: > Bitrex is a new levelling agent for copper. > The addition of Bitrex increases corrosion resistance of copper films. > The nature of pure copper electrodeposits depends on the growth template size. > Bitrex increases coppers current efficiency. - Abstract: We investigate the effects of denatonium benzoate (Bitrex) on the electrodeposition of copper films from a boric acid bath using scanning electron microscopy, cyclic voltammetry, electrochemical quartz microbalance (EQCM) measurements and corrosion studies. In the absence of Bitrex, pure copper films grown by this method are optically black owing to the appearance of complex surface nanostructures. The addition of Bitrex acts as a levelling agent preventing the formation of these nanostructures even for concentrations as low as 0.02 mM producing a lustrous film with low surface roughness. Bitrex is also found to improve the corrosion resistance by up to a factor of 20 and increase the current efficiency by over a factor of two. Bitrex is hypothesised to act directly on the cathode, partially inhibiting the growth or lowering the deposition current.

  9. Transportation dynamics on networks of mobile agents

    CERN Document Server

    Yang, Han-Xin; Xie, Yan-Bo; Lai, Ying-Cheng; Wang, Bing-Hong

    2011-01-01

    Most existing works on transportation dynamics focus on networks of a fixed structure, but networks whose nodes are mobile have become widespread, such as cell-phone networks. We introduce a model to explore the basic physics of transportation on mobile networks. Of particular interest are the dependence of the throughput on the speed of agent movement and communication range. Our computations reveal a hierarchical dependence for the former while, for the latter, we find an algebraic power law between the throughput and the communication range with an exponent determined by the speed. We develop a physical theory based on the Fokker-Planck equation to explain these phenomena. Our findings provide insights into complex transportation dynamics arising commonly in natural and engineering systems.

  10. Social cognitive theory: an agentic perspective.

    Science.gov (United States)

    Bandura, A

    2001-01-01

    The capacity to exercise control over the nature and quality of one's life is the essence of humanness. Human agency is characterized by a number of core features that operate through phenomenal and functional consciousness. These include the temporal extension of agency through intentionality and forethought, self-regulation by self-reactive influence, and self-reflectiveness about one's capabilities, quality of functioning, and the meaning and purpose of one's life pursuits. Personal agency operates within a broad network of sociostructural influences. In these agentic transactions, people are producers as well as products of social systems. Social cognitive theory distinguishes among three modes of agency: direct personal agency, proxy agency that relies on others to act on one's behest to secure desired outcomes, and collective agency exercised through socially coordinative and interdependent effort. Growing transnational embeddedness and interdependence are placing a premium on collective efficacy to exercise control over personal destinies and national life.

  11. Engineering knottins as novel binding agents.

    Science.gov (United States)

    Moore, Sarah J; Cochran, Jennifer R

    2012-01-01

    Cystine-knot miniproteins, also known as knottins, contain a conserved core of three tightly woven disulfide bonds which impart extraordinary thermal and proteolytic stability. Interspersed between their conserved cysteine residues are constrained loops that possess high levels of sequence diversity among knottin family members. Together these attributes make knottins promising molecular scaffolds for protein engineering and translational applications. While naturally occurring knottins have shown potential as both diagnostic agents and therapeutics, protein engineering is playing an important and increasing role in creating designer molecules that bind to a myriad of biomedical targets. Toward this goal, rational and combinatorial approaches have been used to engineer knottins with novel molecular recognition properties. Here, methods are described for creating and screening knottin libraries using yeast surface display and fluorescence-activated cell sorting. Protocols are also provided for producing knottins by synthetic and recombinant methods, and for measuring the binding affinity of knottins to target proteins expressed on the cell surface.

  12. Thyroid Dysfunction from Antineoplastic Agents

    Science.gov (United States)

    Larsen, P. Reed; Marqusee, Ellen

    2011-01-01

    Unlike cytotoxic agents that indiscriminately affect rapidly dividing cells, newer antineoplastic agents such as targeted therapies and immunotherapies are associated with thyroid dysfunction. These include tyrosine kinase inhibitors, bexarotene, radioiodine-based cancer therapies, denileukin diftitox, alemtuzumab, interferon-α, interleukin-2, ipilimumab, tremelimumab, thalidomide, and lenalidomide. Primary hypothyroidism is the most common side effect, although thyrotoxicosis and effects on thyroid-stimulating hormone secretion and thyroid hormone metabolism have also been described. Most agents cause thyroid dysfunction in 20%–50% of patients, although some have even higher rates. Despite this, physicians may overlook drug-induced thyroid dysfunction because of the complexity of the clinical picture in the cancer patient. Symptoms of hypothyroidism, such as fatigue, weakness, depression, memory loss, cold intolerance, and cardiovascular effects, may be incorrectly attributed to the primary disease or to the antineoplastic agent. Underdiagnosis of thyroid dysfunction can have important consequences for cancer patient management. At a minimum, the symptoms will adversely affect the patient’s quality of life. Alternatively, such symptoms can lead to dose reductions of potentially life-saving therapies. Hypothyroidism can also alter the kinetics and clearance of medications, which may lead to undesirable side effects. Thyrotoxicosis can be mistaken for sepsis or a nonendocrinologic drug side effect. In some patients, thyroid disease may indicate a higher likelihood of tumor response to the agent. Both hypothyroidism and thyrotoxicosis are easily diagnosed with inexpensive and specific tests. In many patients, particularly those with hypothyroidism, the treatment is straightforward. We therefore recommend routine testing for thyroid abnormalities in patients receiving these antineoplastic agents. PMID:22010182

  13. Thyroid dysfunction from antineoplastic agents.

    Science.gov (United States)

    Hamnvik, Ole-Petter Riksfjord; Larsen, P Reed; Marqusee, Ellen

    2011-11-02

    Unlike cytotoxic agents that indiscriminately affect rapidly dividing cells, newer antineoplastic agents such as targeted therapies and immunotherapies are associated with thyroid dysfunction. These include tyrosine kinase inhibitors, bexarotene, radioiodine-based cancer therapies, denileukin diftitox, alemtuzumab, interferon-α, interleukin-2, ipilimumab, tremelimumab, thalidomide, and lenalidomide. Primary hypothyroidism is the most common side effect, although thyrotoxicosis and effects on thyroid-stimulating hormone secretion and thyroid hormone metabolism have also been described. Most agents cause thyroid dysfunction in 20%-50% of patients, although some have even higher rates. Despite this, physicians may overlook drug-induced thyroid dysfunction because of the complexity of the clinical picture in the cancer patient. Symptoms of hypothyroidism, such as fatigue, weakness, depression, memory loss, cold intolerance, and cardiovascular effects, may be incorrectly attributed to the primary disease or to the antineoplastic agent. Underdiagnosis of thyroid dysfunction can have important consequences for cancer patient management. At a minimum, the symptoms will adversely affect the patient's quality of life. Alternatively, such symptoms can lead to dose reductions of potentially life-saving therapies. Hypothyroidism can also alter the kinetics and clearance of medications, which may lead to undesirable side effects. Thyrotoxicosis can be mistaken for sepsis or a nonendocrinologic drug side effect. In some patients, thyroid disease may indicate a higher likelihood of tumor response to the agent. Both hypothyroidism and thyrotoxicosis are easily diagnosed with inexpensive and specific tests. In many patients, particularly those with hypothyroidism, the treatment is straightforward. We therefore recommend routine testing for thyroid abnormalities in patients receiving these antineoplastic agents.

  14. Autonomous sensor manager agents (ASMA)

    Science.gov (United States)

    Osadciw, Lisa A.

    2004-04-01

    Autonomous sensor manager agents are presented as an algorithm to perform sensor management within a multisensor fusion network. The design of the hybrid ant system/particle swarm agents is described in detail with some insight into their performance. Although the algorithm is designed for the general sensor management problem, a simulation example involving 2 radar systems is presented. Algorithmic parameters are determined by the size of the region covered by the sensor network, the number of sensors, and the number of parameters to be selected. With straight forward modifications, this algorithm can be adapted for most sensor management problems.

  15. Agentes infecciosos y enfermedades autoinmunes

    OpenAIRE

    Carlos Riebeling; Vicente Madrid; Beatriz Elena Camarena; Oscar Peralta; Raúl Barrera

    1992-01-01

    En este trabajo se describen los aspectos molecidares de la relación entre agentes infecciosos y enfermedades autoinrnitnes; los mecanismos de respuesta inmune a los agentes infecciosos, y las Iiiyótesis más recientes de la causa de las enfermedades autoinmunes. Los antígenos son procesados y seleccionados por su inmitnogenicidad, ypresentadospor lasmolécitlasde HLA a los receptores de antígeno de los linfocitos T. Aunque existen rnuclias hipótesk sobre el origen de las enfermedades arrtoinmu...

  16. Biocommunication and natural genome editing

    Institute of Scientific and Technical Information of China (English)

    Guenther; Witzany

    2010-01-01

    The biocommunicative approach investigates communication processes within and among cells,tissues,organs and organisms as sign-mediated interactions,and nucleotide sequences as code,i.e.language-like text,which follows in parallel three kinds of rules:combinatorial (syntactic),context-sensitive(pragmatic),and contentspecific(semantic).Natural genome editing from a bio-communicative perspective is competent agent-driven generation and integration of meaningful nucleotide sequences into pre-existing genomic content arrangements and the ability to(re-)combine and(re-)regulate them according to context-dependent(i.e.adaptational) purposes of the host organism.

  17. 13 CFR 120.952 - Fiscal agent.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Fiscal agent. 120.952 Section 120... Loan Program (504) Debenture Sales and Service Agents § 120.952 Fiscal agent. SBA shall appoint a Fiscal Agent to assess the financial markets, minimize the cost of sales, arrange for the production...

  18. Cooperative epistemic multi-agent planning for implicit coordination

    DEFF Research Database (Denmark)

    Engesser, Thorsten; Bolander, Thomas; Mattmüller, Robert

    2017-01-01

    Epistemic planning can be used for decision making in multi-agent situations with distributed knowledge and capabilities. Recently, Dynamic Epistemic Logic (DEL) has been shown to provide a very natural and expressive framework for epistemic planning. We extend the DEL-based epistemic planning...... framework to include perspective shifts, allowing us to define new notions of sequential and conditional planning with implicit coordination. With these, it is possible to solve planning tasks with joint goals in a decentralized manner without the agents having to negotiate about and commit to a joint...... policy at plan time. First we define the central planning notions and sketch the implementation of a planning system built on those notions. Afterwards we provide some case studies in order to evaluate the planner empirically and to show that the concept is useful for multi-agent systems in practice....

  19. SEM: A Cultural Change Agent

    Science.gov (United States)

    Barnes, Bradley; Bourke, Brian

    2015-01-01

    The authors advance the concept that institutional culture is a purposeful framework by which to view SEM's utility, particularly as a cultural change agent. Through the connection of seemingly independent functions of performance and behavior, implications emerge that deepen the understanding of the influence of culture on performance outcomes…

  20. Raspberry Pi for secret agents

    CERN Document Server

    Sjogelid, Stefan

    2015-01-01

    This book is an easy-to-follow guide with practical examples in each chapter. Suitable for the novice and expert alike, each topic provides a fast and easy way to get started with exciting applications and also guides you through setting up the Raspberry Pi as a secret agent toolbox.

  1. Multi-Agent Transport Planning

    NARCIS (Netherlands)

    Zutt, J.; Witteveen, C.

    2005-01-01

    We discuss a distributed transport planning problem with competitive autonomous actors that carry out time-constrained pick-up delivery orders from customers. The agents have to find conflict-free routes to execute a series of orders they have accepted. Hatzack and Nebel [2] were the first to sugges

  2. The Power Trading Agent Competition

    NARCIS (Netherlands)

    W. Ketter (Wolfgang); J. Collins (John); P. Reddy (Prashant); C. Flath (Christoph); M.M. de Weerdt (Mathijs)

    2011-01-01

    textabstractThis is the specification for the Power Trading Agent Competition for 2012 (Power TAC 2012). Power TAC is a competitive simulation that models a “liberalized” retail electrical energy market, where competing business entities or “brokers” offer energy services to customers through tariff

  3. The Power Trading Agent Competition

    NARCIS (Netherlands)

    Ketter, W.; Collins, J.; Reddy, P.; Flath, C.; De Weerdt, M.M.

    2011-01-01

    This is the specification for the Power Trading Agent Competition for 2012 (Power TAC 2012). Power TAC is a competitive simulation that models a “liberalized” retail electrical energy market, where competing business entities or “brokers” offer energy services to customers through tariff contracts,

  4. Humor and embodied conversational agents

    NARCIS (Netherlands)

    Nijholt, A.

    2003-01-01

    This report surveys the role of humor in human-to-human interaction and the possible role of humor in human-computer interaction. The aim is to see whether it is useful for embodied conversational agents to integrate humor capabilities in their internal model of intelligence, emotions and interactio

  5. Kriitikute lemmikfilm on "Agent Sinikael"

    Index Scriptorium Estoniae

    2003-01-01

    Eesti Filmiajakirjanike Ühing andis kümnendat korda välja auhinda Aasta film 2002. Parimaks filmiks tunnistati mängufilm "Agent Sinikael" : režissöör Marko Raat. Viimane sai preemiaks Neitsi Maali kuju ja 12 000 krooni

  6. Biotech drugs : biological therapeutic agents

    OpenAIRE

    Grech, Godfrey; Fenech, Anthony

    2009-01-01

    The recent years has seen significant growth in a new therapeutic approach to the management of disease. Biological therapeutic agents, constitute a broad category of drugs, usually generated by recombinant techniques from living organisms. These therapies revolutionise the traditional approaches to drug design and development, and regulatory agencies have been swift in developing the necessary structures to ensure their optimal use.

  7. Relational agents: A critical review

    DEFF Research Database (Denmark)

    Campbell, Robert H.; Grimshaw, Mark Nicholas; Green, Gill

    2009-01-01

    Relationships between people who meet in virtual worlds are common and these relationships can be long term, in some cases lasting a life-time. Although relationships formed in virtual worlds have invited a lot of recent interest, surprisingly little work has been done on developing computer agents...

  8. Biocontrol agents in signalling resistance

    NARCIS (Netherlands)

    Loon, L.C. van; Pieterse, C.M.J.

    2002-01-01

    The mechanisms by which biological control agents suppress disease comprise competition for nutrients, notably iron, production of antibiotics, and secretion of lytic enzymes, as well as inducing resistance in the plant. The former three mechanisms act primarily on the pathogen by decreasing its

  9. Identity Management in Agent Systems

    NARCIS (Netherlands)

    Brazier, F.M.T.; Groot, de D.R.A.

    2006-01-01

    If agent-based applications are to be used in large scale, open environments, security is a main issue; digital identity management (DIDM) an essential element. DIDM is needed to be able to determine the rights and obligations of the four main

  10. Kriitikute lemmikfilm on "Agent Sinikael"

    Index Scriptorium Estoniae

    2003-01-01

    Eesti Filmiajakirjanike Ühing andis kümnendat korda välja auhinda Aasta film 2002. Parimaks filmiks tunnistati mängufilm "Agent Sinikael" : režissöör Marko Raat. Viimane sai preemiaks Neitsi Maali kuju ja 12 000 krooni

  11. Lipoprotein Nanoplatform for Targeted Delivery of Diagnostic and Therapeutic Agents

    Directory of Open Access Journals (Sweden)

    Jerry D. Glickson

    2008-03-01

    Full Text Available Low-density lipoprotein (LDL provides a highly versatile natural nanoplatform for delivery of visible or near-infrared fluorescent optical and magnetic resonance imaging (MRI contrast agents and photodynamic therapy and chemotherapeutic agents to normal and neoplastic cells that overexpress low-density lipoprotein receptors (LDLRs. Extension to other lipoproteins ranging in diameter from about 10 nm (high-density lipoprotein [HDL] to over a micron (chylomicrons is feasible. Loading of contrast or therapeutic agents onto or into these particles has been achieved by protein loading (covalent attachment to protein side chains, surface loading (intercalation into the phospholipid monolayer, and core loading (extraction and reconstitution of the triglyceride/cholesterol ester core. Core and surface loading of LDL have been used for delivery of optical imaging agents to tumor cells in vivo and in culture. Surface loading was used for delivery of gadolinium-bis-stearylamide contrast agents for in vivo MRI detection in tumor-bearing mice. Chlorin and phthalocyanine near-infrared photodynamic therapy agents (≤ 400/LDL have been attached by core loading. Protein loading was used to reroute the LDL from its natural receptor (LDLR to folate receptors and could be used to target other receptors. A semisynthetic nanoparticle has been constructed by coating magnetite iron oxide nanoparticles with carboxylated cholesterol and overlaying a monolayer of phospholipid to which apolipoprotein A1 or E was adsorbed for targeting HDL or adsorbing synthetic amphipathic helical peptides ltargeting LDL or folate receptors. These particles can be used for in situ loading of magnetite into cells for MRI-monitored cell tracking or gene expression.

  12. Halide test agent replacement study

    Energy Technology Data Exchange (ETDEWEB)

    Banks, E.M.; Freeman, W.P.; Kovach, B.J. [and others

    1995-02-01

    The intended phaseout of the chlorofluorocarbons (CFCs) from commercial use required the evaluation of substitute materials for the testing for leak paths through both individual adsorbers and installed adsorbent banks. The American Society of Mechanical Engineers (ASME) Committee on Nuclear Air and Gas Treatment (CONAGT) is in charge of maintaining the standards and codes specifying adsorbent leak test methods for the nuclear safety related air cleaning systems. The currently published standards and codes cite the use of R-11, R-12 and R-112 for leak path test agents. All of these compounds are CFCs. There are other agencies and organizations (USDOE, USDOD and USNRC) also specifying testing for leak paths or in some cases for special life tests using the above compounds. The CONAGT has recently developed criteria for the suitability evaluation of substitute test agents. On the basis of these criteria, several compounds were evaluated for their acceptability as adsorbent bed leak and life test agents. The ASME CONAGT Test Agent Qualification Criteria. The test agent qualification is based on the following parameters: (1) Similar retention times on activated carbons at the same concentration levels as one of the following: R-11, R-12, R-112 or R-112a. (2) Similar lower detection limit sensitivity and precision in the concentration range of use as R-11, R-12, R-112 and R-112a. (3) Gives the same in-place leak test results as R-11, R-12, R-112, or R-112a. (4) Chemical and radiological stability under the use conditions. (5) Causes no degradation of the carbon and its impregnant or of the other NATS components under the use conditions. (6) Is listed in the USEPA Toxic Substances Control Act (TSCA) inventory for commercial use.

  13. Sequestering agents for the removal of actinides from waste streams

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, K.N.; White, D.J.; Xu, Jide; Mohs, T.R. [Univ. of California, Berkeley, CA (United States)

    1997-10-01

    The goal of this project is to take a biomimetic approach toward developing new separation technologies for the removal of radioactive elements from contaminated DOE sites. To achieve this objective, the authors are investigating the fundamental chemistry of naturally occurring, highly specific metal ion sequestering agents and developing them into liquid/liquid and solid supported actinide extraction agents. Nature produces sideophores (e.g., Enterobactin and Desferrioxamine B) to selectivity sequester Lewis acidic metal ions, in particular Fe(III), from its surroundings. These chelating agents typically use multiple catechols or hydroxamic acids to form polydentate ligands that chelate the metal ion forming very stable complexes. The authors are investigating and developing analogous molecules into selective chelators targeting actinide(IV) ions, which display similar properties to Fe(III). By taking advantage of differences in charge, preferred coordination number, and pH stability range, the transition from nature to actinide sequestering agents has been applied to the development of new and highly selective actinide extraction technologies. Additionally, the authors have shown that these chelating ligands are versatile ligands for chelating U(VI). In particular, they have been studying their coordination chemistry and fundamental interactions with the uranyl ion [UO{sub 2}]{sup 2+}, the dominant form of uranium found in aqueous media. With an understanding of this chemistry, and results obtained from in vivo uranium sequestration studies, it should be possible to apply these actinide(IV) extraction technologies to the development of new extraction agents for the removal of uranium from waste streams.

  14. Persuasive Teachable Agent for Intergenerational Learning

    OpenAIRE

    Lim, Su Fang

    2016-01-01

    Teachable agents are computer agents based on the pedagogical concept of learning-by-teaching. During the tutoring process, where students take on the role of the tutor to teach a computer agent tutee, learners have been observed to gain deeper understanding of the subject matter. Teachable agents are commonly used in the areas of science and mathematics learning where learners are able to learn complex concepts and deep reasoning by teaching the teachable agent through graphic representation...

  15. Migration Dynamics in Artificial Agent Societies

    Directory of Open Access Journals (Sweden)

    Harjot Kaur

    2014-02-01

    Full Text Available An Artificial Agent Society can be defined as a collection of agents interacting with each other for some purpose and/or inhabiting a specific locality, possibly in accordance to some common norms/rules. These societies are analogous to human and ecological societies, and are an expanding and emerging field in research about social systems. Social networks, electronic markets and disaster management organizations can be viewed as such artificial (open agent societies and can be best understood as computational societies. Members of such artificial agent societies are heterogeneous intelligent software agents which are operating locally and cooperating and coordinating with each other in order to achieve goals of an agent society. These artificial agent societies have some kind of dynamics existing in them in terms of dynamics of Agent Migration, Role-Assignment, Norm- Emergence, Security and Agent-Interaction. In this paper, we have described the dynamics of agent migration process, starting from the various types of agent migration, causes or reasons for agent migration, consequences of agent migration, and an agent migration framework to model the its behavior for migration of agents between societies.

  16. Space as an invention of active agents

    Directory of Open Access Journals (Sweden)

    Alexander V Terekhov

    2016-03-01

    Full Text Available The question of the nature of space around us has occupied thinkers since the dawn of humanity, with scientists and philosophers today implicitly assuming that space is something that exists objectively. Here we show that this does not have to be the case: the notion of space could emerge when biological organisms seek an economic representation of their sensorimotor flow. The emergence of spatial notions does not necessitate the existence of real physical space, but only requires the presence of sensorimotor invariants called 'compensable' sensory changes. We show mathematically and then in simulations that naive agents making no assumptions about the existence of space are able to learn these invariants and to build the abstract notion that physicists call rigid displacement, independent of what is being displaced. Rigid displacements may underly perception of space as an unchanging medium within which objects are described by their relative positions. Our findings suggest that the question of the nature of space, currently exclusive to philosophy and physics, should also be addressed from the standpoint of neuroscience and artificial intelligence.

  17. Control Prosody using Multi-Agent System

    Directory of Open Access Journals (Sweden)

    Kenji MATSUI

    2014-03-01

    Full Text Available Persons who have undergone a laryngectomy have a few options to partially restore speech but no completely satisfactory device. Even though the use of an electrolarynx (EL is the easiest way for a patient to produce speech, it does not produce a natural tone and appearance is far from normal. Because of that and the fact that none of them are hands-free, the feasibility of using a motion sensor to replace a conventional EL user interface has been explored. A mobile device motion sensor with multi-agent platform has been used to investigate on/off and pitch frequency control capability. A very small battery operated ARM-based control unit has also been developed to evaluate the motion sensor based user-interface. This control unit is placed on the wrist and the vibration device against the throat using support bandage. Two different conversion methods were used for the forearm tilt angle to pitch frequency conversion: linear mapping method and F0 template-based method A perceptual evaluation has been performed with two well-trained normal speakers and ten subjects. The results of the evaluation study showed that both methods are able to produce better speech quality in terms of the naturalness.

  18. 2,5-diketopiperazines as neuroprotective agents.

    Science.gov (United States)

    Cornacchia, C; Cacciatore, I; Baldassarre, L; Mollica, A; Feliciani, F; Pinnen, F

    2012-01-01

    2,5-diketopiperazines are the simplest cyclic peptides found in nature, commonly biosynthesized from amino acids by different organisms, and represent a promising class of biologically active natural products. Their peculiar heterocyclic structure confers high stability against the proteolysis and constitutes a structural requirement for the active intestinal absorption. Furthermore, the diketopiperazine-based motif is considered as a novel brain shuttle for the delivery of drugs with limited ability to cross the blood-brain barrier (BBB) and can be proposed as an ideal candidate for the rational development of new therapeutic agents. Although these cyclic peptides have been known since the beginning of the 20th century, only recently have they attracted substantial interest with respect to the wide spectrum of their biological properties, including antitumor, antiviral, antifungal, antibacterial and antihyperglycemic activities. In addition to these, the most challenging function of the diketopiperazine derivatives is related with their remarkable neuroprotective and nootropic activity. The aim of the present paper is to provide an overview of the two major classes of diketopiperazines, the TRH-related and the unsaturated derivatives both characterized by a significant ability to protect against neurotoxicity in several experimental models. The neuroprotective profile of these compounds suggests that they may have a future utility in the therapy of neuronal degeneration in vivo, potentially through several different mechanisms.

  19. A Design of a Multi-Agent Smart E-Examiner

    Directory of Open Access Journals (Sweden)

    Khaled Nasser ElSayed

    2015-10-01

    Full Text Available this paper proposes a design of an application of multi agent technology on a semantic net knowledge base, to build a smart e-examiner system. This e-examiner could be used in building and grading a personalized special on-line e-assessment. The produced e-assessment should cover the majority of examined topics and material. It should cover various levels of difficulties and learners profile(s. The e-examiner will use a semantic net question bank, to emphasize on the structuring categories of all course domains. This task is done through four different intelligent agents: control agent, personal agent, examiner agent, and grading agent. The system might select questions from a bank of questions for several courses. It could be used in different education levels and natures. Also, it will produce a key for the produced exam, to be used latter in grading, and giving final marks of e-assessments.

  20. The Antiradical Activity of Insoluble Water Suji (Pleomele angustifolia N.E. Brown) Leaf Extract and Its Application as Natural Colorant in Bread product

    OpenAIRE

    Jokopriyambodo, Wahyu

    2014-01-01

    Currently, there are some synthetic colouring agents present in food products. The synthetic colouring agents are supposed to give deleterious effect to human health; therefore, natural coloring agents derived from plant is continuously explored to replace the synthetic ones. Suji (Pleomele angustifolia) leaf is one of the potential plant to be used as natural coloring agents. The aim of this study is to explore the natural colour potency and antiradical activity of insoluble water extract of...

  1. Development of Class IIa Bacteriocins as Therapeutic Agents

    OpenAIRE

    Lohans, Christopher T.; Vederas, John C.

    2012-01-01

    Class IIa bacteriocins have been primarily explored as natural food preservatives, but there is much interest in exploring the application of these peptides as therapeutic antimicrobial agents. Bacteriocins of this class possess antimicrobial activity against several important human pathogens. Therefore, the therapeutic development of these bacteriocins will be reviewed. Biological and chemical modifications to both stabilize and increase the potency of bacteriocins are discussed, as well as ...

  2. Identification of novel and improved antimitotic agents derived from noscapine.

    Science.gov (United States)

    Anderson, James T; Ting, Anthony E; Boozer, Sherry; Brunden, Kurt R; Crumrine, Chris; Danzig, Joel; Dent, Tom; Faga, Laurel; Harrington, John J; Hodnick, William F; Murphy, Steven M; Pawlowski, Gary; Perry, Robert; Raber, Amy; Rundlett, Stephen E; Stricker-Krongrad, Alain; Wang, Jianmin; Bennani, Youssef L

    2005-11-17

    Analogues of the natural product noscapine were synthesized and their potential as antitumor agents evaluated. The discovery of a novel regioselective O-demethylation facilitated the synthesis of the potent aniline 6, which arrests mammalian cells in the G2/M phase of the cell cycle at 0.1 microM and also affects tubulin polymerization. Aniline 6 is orally bioavailable and is 250-fold more potent than noscapine in reducing cell proliferation in rapidly dividing cells.

  3. Biomorphic Multi-Agent Architecture for Persistent Computing

    Science.gov (United States)

    Lodding, Kenneth N.; Brewster, Paul

    2009-01-01

    A multi-agent software/hardware architecture, inspired by the multicellular nature of living organisms, has been proposed as the basis of design of a robust, reliable, persistent computing system. Just as a multicellular organism can adapt to changing environmental conditions and can survive despite the failure of individual cells, a multi-agent computing system, as envisioned, could adapt to changing hardware, software, and environmental conditions. In particular, the computing system could continue to function (perhaps at a reduced but still reasonable level of performance) if one or more component( s) of the system were to fail. One of the defining characteristics of a multicellular organism is unity of purpose. In biology, the purpose is survival of the organism. The purpose of the proposed multi-agent architecture is to provide a persistent computing environment in harsh conditions in which repair is difficult or impossible. A multi-agent, organism-like computing system would be a single entity built from agents or cells. Each agent or cell would be a discrete hardware processing unit that would include a data processor with local memory, an internal clock, and a suite of communication equipment capable of both local line-of-sight communications and global broadcast communications. Some cells, denoted specialist cells, could contain such additional hardware as sensors and emitters. Each cell would be independent in the sense that there would be no global clock, no global (shared) memory, no pre-assigned cell identifiers, no pre-defined network topology, and no centralized brain or control structure. Like each cell in a living organism, each agent or cell of the computing system would contain a full description of the system encoded as genes, but in this case, the genes would be components of a software genome.

  4. The New Agent: A Qualitative Study to Strategically Adapt New Agent Professional Development

    Science.gov (United States)

    Baker, Lauri M.; Hadley, Gregg

    2014-01-01

    The qualitative study reported here assessed the needs of agents related to new agent professional development to improve the current model. Agents who participated in new agent professional development within the last 5 years were selected to participate in focus groups to determine concerns and continued needs. Agents enjoyed networking and…

  5. Metathesis access to monocyclic iminocyclitol-based therapeutic agents

    Directory of Open Access Journals (Sweden)

    Albert Demonceau

    2011-05-01

    Full Text Available By focusing on recent developments on natural and non-natural azasugars (iminocyclitols, this review bolsters the case for the role of olefin metathesis reactions (RCM, CM as key transformations in the multistep syntheses of pyrrolidine-, piperidine- and azepane-based iminocyclitols, as important therapeutic agents against a range of common diseases and as tools for studying metabolic disorders. Considerable improvements brought about by introduction of one or more metathesis steps are outlined, with emphasis on the exquisite steric control and atom-economical outcome of the overall process. The comparative performance of several established metathesis catalysts is also highlighted.

  6. The Application of Intentional Subjective Properties and Mediated Communication Tools to Software Agents in Online Disputes Resolution Environments

    Directory of Open Access Journals (Sweden)

    Renzo Gobbin

    2004-11-01

    Full Text Available This paper examines the use of subjective properties in modeling an architecture for cooperative agents using Agent Communication Language (ACL that is used as a mediating tool for cooperative communication activities between and within software agents. The role that subjective and objective properties have in explaining and modeling agent internalization and externalization of ACL messages is investigated and related to Vygotsky’s developmental learning theories such as Mediated Activity Theory. A novel agent architecture ALMA (Agent Language Mediated Activity based on the integration of agents’ subjective and objective properties within an agent communication activity framework will be presented. The relevance of software agents subjective properties in modeling applications such as e-Law Online Dispute Resolution for e-business contractual arrangements using natural language subject/object relation in their communication patterns will be discussed.

  7. Surface decontamination for blister agents Lewisite, sulfur mustard and agent yellow, a Lewisite and sulfur mustard mixture.

    Science.gov (United States)

    Stone, Harry; See, David; Smiley, Autumn; Ellingson, Anthony; Schimmoeller, Jessica; Oudejans, Lukas

    2016-08-15

    Sulfur mustard (HD) and Lewisite (L) are blister agents that have a high potential for terrorist use; Agent Yellow (HL) is the eutectic mixture of HD and L. Bench-scale testing was used to determine the residual amount of these chemical warfare agents remaining on three building materials (wood, metal and glass) after application of various decontaminants (household bleach, full strength and dilute; hydrogen peroxide 3% solution; and EasyDECON(®) DF200). All decontaminants reduced the amount of L recovered from coupons. Application of dilute bleach showed little or no difference compared to natural attenuation in the amount of HD recovered from coupons. Full-strength bleach was the most effective of four decontaminants at reducing the amount of HD from coupons. Hydrogen peroxide (3% solution) and DF200 did decrease the amount of HD recovered from coupons more than natural attenuation (except DF200 against HD on metal), but substantial amounts of HD remained on some materials. Toxic HD by-products were generated by hydrogen peroxide treatment. The effectiveness of decontaminants was found to depend on agent, material, and decontaminant. Increased decontaminant reaction time (60min rather than 30min) did not significantly increase effectiveness. Published by Elsevier B.V.

  8. Needs, Pains, and Motivations in Autonomous Agents.

    Science.gov (United States)

    Starzyk, Janusz A; Graham, James; Puzio, Leszek

    2016-08-17

    This paper presents the development of a motivated learning (ML) agent with symbolic I/O. Our earlier work on the ML agent was enhanced, giving it autonomy for interaction with other agents. Specifically, we equipped the agent with drives and pains that establish its motivations to learn how to respond to desired and undesired events and create related abstract goals. The purpose of this paper is to explore the autonomous development of motivations and memory in agents within a simulated environment. The ML agent has been implemented in a virtual environment created within the NeoAxis game engine. Additionally, to illustrate the benefits of an ML-based agent, we compared the performance of our algorithm against various reinforcement learning (RL) algorithms in a dynamic test scenario, and demonstrated that our ML agent learns better than any of the tested RL agents.

  9. CATS-based Agents That Err

    Science.gov (United States)

    Callantine, Todd J.

    2002-01-01

    This report describes preliminary research on intelligent agents that make errors. Such agents are crucial to the development of novel agent-based techniques for assessing system safety. The agents extend an agent architecture derived from the Crew Activity Tracking System that has been used as the basis for air traffic controller agents. The report first reviews several error taxonomies. Next, it presents an overview of the air traffic controller agents, then details several mechanisms for causing the agents to err in realistic ways. The report presents a performance assessment of the error-generating agents, and identifies directions for further research. The research was supported by the System-Wide Accident Prevention element of the FAA/NASA Aviation Safety Program.

  10. Chaotic neurodynamics for autonomous agents.

    Science.gov (United States)

    Harter, Derek; Kozma, Robert

    2005-05-01

    Mesoscopic level neurodynamics study the collective dynamical behavior of neural populations. Such models are becoming increasingly important in understanding large-scale brain processes. Brains exhibit aperiodic oscillations with a much more rich dynamical behavior than fixed-point and limit-cycle approximation allow. Here we present a discretized model inspired by Freeman's K-set mesoscopic level population model. We show that this version is capable of replicating the important principles of aperiodic/chaotic neurodynamics while being fast enough for use in real-time autonomous agent applications. This simplification of the K model provides many advantages not only in terms of efficiency but in simplicity and its ability to be analyzed in terms of its dynamical properties. We study the discrete version using a multilayer, highly recurrent model of the neural architecture of perceptual brain areas. We use this architecture to develop example action selection mechanisms in an autonomous agent.

  11. Logical Theories for Agent Introspection

    DEFF Research Database (Denmark)

    Bolander, Thomas

    2004-01-01

    Artificial intelligence systems (agents) generally have models of the environments they inhabit which they use for representing facts, for reasoning about these facts and for planning actions. Much intelligent behaviour seems to involve an ability to model not only one's external environment...... by self-reference. In the standard approach taken in artificial intelligence, the model that an agent has of its environment is represented as a set of beliefs. These beliefs are expressed as logical formulas within a formal, logical theory. When the logical theory is expressive enough to allow...... introspective reasoning, the presence of self-reference causes the theory to be prone to inconsistency. The challenge therefore becomes to construct logical theories supporting introspective reasoning while at the same time ensuring that consistency is retained. In the thesis, we meet this challenge by devising...

  12. Bacteriocins as potential anticancer agents

    Directory of Open Access Journals (Sweden)

    Sukhraj eKaur

    2015-11-01

    Full Text Available Cancer remains one of the leading causes of deaths worldwide, despite advances in its treatment and detection. The conventional chemotherapeutic agents used for the treatment of cancer have nonspecific toxicity towards normal body cells that cause various side effects. Secondly, cancer cells are known to develop chemotherapy resistance in due course of treatment. Thus, the demand for novel anti-cancer agents is increasing day by day. Some of the experimental studies have reported the therapeutic potential of bacteriocins against various types of cancer cell lines. Bacteriocins are ribosomally-synthesized cationic peptides secreted by almost all groups of bacteria. Some bacteriocins have shown selective cytotoxicity towards cancer cells as compared to normal cells. This makes them promising candidates for further investigation and clinical trials. In this review article, we present the overview of the various cancer cell-specific cytotoxic bacteriocins, their mode of action and efficacies.

  13. Subharmonic imaging of contrast agents.

    Science.gov (United States)

    Forsberg, F; Shi, W T; Goldberg, B B

    2000-03-01

    Ultrasound contrast agents promise to improve the sensitivity and specificity of diagnostic ultrasound imaging. It is of great importance to adapt ultrasound equipment for optimal use with contrast agents e.g., by exploiting the nonlinear properties of the contrast microbubbles. Harmonic imaging is one technique that has been extensively studied and is commercially available. However, harmonic imaging is associated with problems, due to second harmonic generation and accumulation within the tissue itself. Given the lack of subharmonic generation in tissue, one alternative is the creation of subharmonic images by transmitting at the fundamental frequency (fo) and receiving at the subharmonic (fo/2). Subharmonic imaging should have a much better lateral resolution and may be suitable for scanning deep-lying structures owing to the higher transmit frequency and the much smaller attenuation of scattered subharmonic signals. In this paper, we will review different aspects of subharmonic imaging including implementation, in-vitro gray-scale imaging and subharmonic aided pressure estimation.

  14. Logical Theories for Agent Introspection

    DEFF Research Database (Denmark)

    Bolander, Thomas

    2004-01-01

    Artificial intelligence systems (agents) generally have models of the environments they inhabit which they use for representing facts, for reasoning about these facts and for planning actions. Much intelligent behaviour seems to involve an ability to model not only one's external environment...... by self-reference. In the standard approach taken in artificial intelligence, the model that an agent has of its environment is represented as a set of beliefs. These beliefs are expressed as logical formulas within a formal, logical theory. When the logical theory is expressive enough to allow...... introspective reasoning, the presence of self-reference causes the theory to be prone to inconsistency. The challenge therefore becomes to construct logical theories supporting introspective reasoning while at the same time ensuring that consistency is retained. In the thesis, we meet this challenge by devising...

  15. Heterogeneous Agents, Distribution and Growth

    OpenAIRE

    Paquin, Lloyd

    1999-01-01

    We modify the Uzawa-Lucas representative agent model of endogenous economic growth to allow for a variety of differences among households: differences in their tastes, in their human capital production technologies, and in their initial endowments. Some differences are incompatible with the existence of a steady- state equilibrium, while others have no effect upon the steady-state growth rate. However, a variety of differences give rise to inequalities in the distribution of income and to var...

  16. Direct Vasodilators and Sympatholytic Agents.

    Science.gov (United States)

    McComb, Meghan N; Chao, James Y; Ng, Tien M H

    2016-01-01

    Direct vasodilators and sympatholytic agents were some of the first antihypertensive medications discovered and utilized in the past century. However, side effect profiles and the advent of newer antihypertensive drug classes have reduced the use of these agents in recent decades. Outcome data and large randomized trials supporting the efficacy of these medications are limited; however, in general the blood pressure-lowering effect of these agents has repeatedly been shown to be comparable to other more contemporary drug classes. Nevertheless, a landmark hypertension trial found a negative outcome with a doxazosin-based regimen compared to a chlorthalidone-based regimen, leading to the removal of α-1 adrenergic receptor blockers as first-line monotherapy from the hypertension guidelines. In contemporary practice, direct vasodilators and sympatholytic agents, particularly hydralazine and clonidine, are often utilized in refractory hypertension. Hydralazine and minoxidil may also be useful alternatives for patients with renal dysfunction, and both hydralazine and methyldopa are considered first line for the treatment of hypertension in pregnancy. Hydralazine has also found widespread use for the treatment of systolic heart failure in combination with isosorbide dinitrate (ISDN). The data to support use of this combination in African Americans with heart failure are particularly robust. Hydralazine with ISDN may also serve as an alternative for patients with an intolerance to angiotensin antagonists. Given these niche indications, vasodilators and sympatholytics are still useful in clinical practice; therefore, it is prudent to understand the existing data regarding efficacy and the safe use of these medications. © The Author(s) 2015.

  17. Thrombotic microangiopathies and antineoplastic agents.

    Science.gov (United States)

    Grangé, Steven; Coppo, Paul

    2017-04-01

    Thrombotic microangiopathy is a well-described complication of cancer treatment. Its incidence has increased these last decades, as a result of a better awareness of this complication in cancer patients in one hand, but also of a larger array of therapeutic compounds including anti-vascular endothelium growth factor (VEGF) drugs. It is therefore mandatory to recognize these conditions since they have a significant impact in thrombotic microangiopathies management and prognosis. Practitioners should be aware of the more classical antineoplastic agents associated with thrombotic microangiopathies, the mechanisms by which they induce them, and the resulting management and prognosis. Since malignancy itself can induce thrombotic microangiopathies, it is also mandatory to know how to distinguish rapidly those caused by antineoplastic agents from those associated with cancer, for an adapted management. Thrombotic microangiopathies associated with chemotherapy remain of dismal prognosis. A better understanding of pathophysiology in these forms of thrombotic microangiopathies, in association with a more empirical approach through the use of new therapeutic agents that can also help in the understanding on new mechanisms a posteriori, should improve their prognosis. The preliminary encouraging results reported with complement blockers in this field could represent a convincing example. Copyright © 2017 Société francophone de néphrologie, dialyse et transplantation. Published by Elsevier Masson SAS. All rights reserved.

  18. Preponderant agent, what is that?

    Directory of Open Access Journals (Sweden)

    Clara Luz Álvarez

    2015-05-01

    Full Text Available Purpose – Preponderant agent is a new instrument for preventing and reverting adverse impact in competition due to highly concentrated markets. Therefore, this paper's objective is to present and analyze the preponderant agent concept in Mexico with emphasis on the broadcast sector, the telecommunication regulator decisions and the courts' interpretation. Methodology/approach/design – The objectives were achieved by researching and analyzing the main legal documents, the Congress reports and debates, the regulator's decisions and other relevant regulator's documents, as well as final decisions by the courts in connection with broadcast sector. Findings – Among the findings are that certain topics were not duly addressed by the Mexican regulator, or by the Congress, whereas the courts were more willing to hold decisions in favor of public interest based on constitutional intent and deference to the regulator's decision. Originality/value – This paper will be valuable for persons interested in telecommunications, broadcast and antitrust. Although the preponderant agent concept created in Mexico is not necessarily a “best practice”, it does provide an alternative instrument in antitrust. Moreover, the courts decisions also provide criteria regarding regulatory deference for the regulator.

  19. Pharmacologic Agents for Chronic Diarrhea.

    Science.gov (United States)

    Lee, Kwang Jae

    2015-10-01

    Chronic diarrhea is usually associated with a number of non-infectious causes. When definitive treatment is unavailable, symptomatic drug therapy is indicated. Pharmacologic agents for chronic diarrhea include loperamide, 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists, diosmectite, cholestyramine, probiotics, antispasmodics, rifaximin, and anti-inflammatory agents. Loperamide, a synthetic opiate agonist, decreases peristaltic activity and inhibits secretion, resulting in the reduction of fluid and electrolyte loss and an increase in stool consistency. Cholestyramine is a bile acid sequestrant that is generally considered as the first-line treatment for bile acid diarrhea. 5-HT3 receptor antagonists have significant benefits in patients with irritable bowel syndrome (IBS) with diarrhea. Ramosetron improves stool consistency as well as global IBS symptoms. Probiotics may have a role in the prevention of antibiotic-associated diarrhea. However, data on the role of probiotics in the treatment of chronic diarrhea are lacking. Diosmectite, an absorbent, can be used for the treatment of chronic functional diarrhea, radiation-induced diarrhea, and chemotherapy-induced diarrhea. Antispasmodics including alverine citrate, mebeverine, otilonium bromide, and pinaverium bromide are used for relieving diarrheal symptoms and abdominal pain. Rifaximin can be effective for chronic diarrhea associated with IBS and small intestinal bacterial overgrowth. Budesonide is effective in both lymphocytic colitis and collagenous colitis. The efficacy of mesalazine in microscopic colitis is weak or remains uncertain. Considering their mechanisms of action, these agents should be prescribed properly.

  20. Multi-agent autonomous system

    Science.gov (United States)

    Fink, Wolfgang (Inventor); Dohm, James (Inventor); Tarbell, Mark A. (Inventor)

    2010-01-01

    A multi-agent autonomous system for exploration of hazardous or inaccessible locations. The multi-agent autonomous system includes simple surface-based agents or craft controlled by an airborne tracking and command system. The airborne tracking and command system includes an instrument suite used to image an operational area and any craft deployed within the operational area. The image data is used to identify the craft, targets for exploration, and obstacles in the operational area. The tracking and command system determines paths for the surface-based craft using the identified targets and obstacles and commands the craft using simple movement commands to move through the operational area to the targets while avoiding the obstacles. Each craft includes its own instrument suite to collect information about the operational area that is transmitted back to the tracking and command system. The tracking and command system may be further coupled to a satellite system to provide additional image information about the operational area and provide operational and location commands to the tracking and command system.