WorldWideScience

Sample records for bactericides ecological effects

  1. Effect of bactericides on sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsova, T A; Gareyshina, A Z; Limanov, V Ye; Neizvestnoya, R G; Yalymova, A G

    1980-01-01

    A study was made of the effect on sulfate-reducing bacteria (SRD) of different bactericides under laboratory conditions. The tests were conducted according to the technique developed in the VNIISPTneft'. A total of 36 chemical reagents were checked. The majority of them completely suppressed the growth of the accumulating culture of the SRD with different concentration of bactericide. The reagents which have good bactericidal action were verified for anticorrosion properties and were tested on field water from well 520 and 6334 of the Aznakayevskiy UKPN. The study results indicated that in selecting the dosing of bactericides on the accumulation culture of the SRD, the bactericidal effect is observed with lower concentration than the SRD collected from the near-face well zones.

  2. Bactericidal effects of antibiotics on slowly growing and nongrowing bacteria.

    OpenAIRE

    Eng, R H; Padberg, F T; Smith, S M; Tan, E N; Cherubin, C E

    1991-01-01

    Antimicrobial agents are most often tested against bacteria in the log phase of multiplication to produce the maximum bactericidal effect. In an infection, bacteria may multiply less optimally. We examined the effects of several classes of antimicrobial agents to determine their actions on gram-positive and gram-negative bacteria during nongrowing and slowly growing phases. Only ciprofloxacin and ofloxacin exhibited bactericidal activity against nongrowing gram-negative bacteria, and no antib...

  3. Bactericidal effect of a 405-nm diode laser on Porphyromonas gingivalis

    Energy Technology Data Exchange (ETDEWEB)

    Kotoku, Y; Kato, J; Akashi, G; Hirai, Y [Department of Operative Dentistry, Tokyo Dental College, 1-2-2, Masago, Mihama-ku, Chiba, 261-8502 (Japan); Ishihara, K [Department of Microbiology, Tokyo Dental College, 1-2-2, Masago, Mihama-ku, Chiba, 261-8502 (Japan)

    2009-05-15

    The study was conducted to determine the effect of 405-nm diode laser irradiation on periodontopathic bacteria such as Porphyromonas gingivalis in vitro. A diluted suspension of P. gingivalis was irradiated directly with a 405-nm diode laser under conditions of 100 mW-10 sec, 100 mW-20 sec, 200 mW-5 sec, 200 mW-10 sec, 200 mW-20 sec, 400 mW-5 sec, 400 mW-10 sec, and 400 mW-20 sec. The energy density ranged from 2.0 to 16.0 J/cm{sup 2}. The irradiated bacterial suspension was spread on a blood agar plate and growth of the colonies was examined after an anaerobic culture for 7 days. Bacterial growth was inhibited under all irradiation conditions, but the bactericidal effect of the 405-nm diode laser depended on the energy density. More than 97% of bacterial growth was inhibited with irradiation at an energy density > 4.0 J/cm{sup 2}. The mechanism of the bactericidal effect is photochemical, rather than photothermal. These findings suggest that a 405-nm diode laser has a high bactericidal effect on P. gingivalis.

  4. Bactericidal effect of a 405-nm diode laser on Porphyromonas gingivalis

    International Nuclear Information System (INIS)

    Kotoku, Y; Kato, J; Akashi, G; Hirai, Y; Ishihara, K

    2009-01-01

    The study was conducted to determine the effect of 405-nm diode laser irradiation on periodontopathic bacteria such as Porphyromonas gingivalis in vitro. A diluted suspension of P. gingivalis was irradiated directly with a 405-nm diode laser under conditions of 100 mW-10 sec, 100 mW-20 sec, 200 mW-5 sec, 200 mW-10 sec, 200 mW-20 sec, 400 mW-5 sec, 400 mW-10 sec, and 400 mW-20 sec. The energy density ranged from 2.0 to 16.0 J/cm 2 . The irradiated bacterial suspension was spread on a blood agar plate and growth of the colonies was examined after an anaerobic culture for 7 days. Bacterial growth was inhibited under all irradiation conditions, but the bactericidal effect of the 405-nm diode laser depended on the energy density. More than 97% of bacterial growth was inhibited with irradiation at an energy density > 4.0 J/cm 2 . The mechanism of the bactericidal effect is photochemical, rather than photothermal. These findings suggest that a 405-nm diode laser has a high bactericidal effect on P. gingivalis

  5. Bactericidal effect of a 405-nm diode laser on Porphyromonas gingivalis

    Science.gov (United States)

    Kotoku, Y.; Kato, J.; Akashi, G.; Hirai, Y.; Ishihara, K.

    2009-05-01

    The study was conducted to determine the effect of 405-nm diode laser irradiation on periodontopathic bacteria such as Porphyromonas gingivalis in vitro. A diluted suspension of P. gingivalis was irradiated directly with a 405-nm diode laser under conditions of 100 mW-10 sec, 100 mW-20 sec, 200 mW-5 sec, 200 mW-10 sec, 200 mW-20 sec, 400 mW-5 sec, 400 mW-10 sec, and 400 mW-20 sec. The energy density ranged from 2.0 to 16.0 J/cm2. The irradiated bacterial suspension was spread on a blood agar plate and growth of the colonies was examined after an anaerobic culture for 7 days. Bacterial growth was inhibited under all irradiation conditions, but the bactericidal effect of the 405-nm diode laser depended on the energy density. More than 97% of bacterial growth was inhibited with irradiation at an energy density > 4.0 J/cm2. The mechanism of the bactericidal effect is photochemical, rather than photothermal. These findings suggest that a 405-nm diode laser has a high bactericidal effect on P. gingivalis.

  6. The bactericidal effect of a Genius (R) Nd : YAG laser

    NARCIS (Netherlands)

    Kranendonk, A.A.; Reijden, W.A. van der; Winkelhoff, A.J. van; Weijden, G.A. van der

    PURPOSE: To evaluate the 'in vitro' bactericidal effect of the Nd:YAG laser (Genius, MØlsgaard Dental, Copenhagen, Denmark) on six periodontal pathogens. METHODS: Suspensions of six different periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella

  7. The bactericidal effect of surface micro-discharge plasma under different ambient conditions

    International Nuclear Information System (INIS)

    Shimizu, T; Zimmermann, J L; Morfill, G E

    2011-01-01

    A series of experiments on the bactericidal properties of plasmas using a surface micro-discharge (SMD) device in an atmosphere under different ambient temperatures and humidities was carried out. This plasma dispenser was developed for use as a disinfection system in private and public places (hospitals, medical practices, etc). The bactericidal effect is due to the interplay of the plasma and the chemical products produced via interactions with O 2 /N 2 and H 2 O vapour in air. To use this device in different countries and therefore under various ambient conditions, it is important to understand its behaviour and efficiency, especially with respect to air temperature and humidity. The experimental results obtained in this study show that the bactericidal properties of the SMD plasma dispenser are not sensitive to the different temperatures and humidities.

  8. The bactericidal effect of surface micro-discharge plasma under different ambient conditions

    Science.gov (United States)

    Shimizu, T.; Zimmermann, J. L.; Morfill, G. E.

    2011-02-01

    A series of experiments on the bactericidal properties of plasmas using a surface micro-discharge (SMD) device in an atmosphere under different ambient temperatures and humidities was carried out. This plasma dispenser was developed for use as a disinfection system in private and public places (hospitals, medical practices, etc). The bactericidal effect is due to the interplay of the plasma and the chemical products produced via interactions with O2/N2 and H2O vapour in air. To use this device in different countries and therefore under various ambient conditions, it is important to understand its behaviour and efficiency, especially with respect to air temperature and humidity. The experimental results obtained in this study show that the bactericidal properties of the SMD plasma dispenser are not sensitive to the different temperatures and humidities.

  9. Bactericidal Effects and Mechanism of Action of Olanexidine Gluconate, a New Antiseptic

    Science.gov (United States)

    Iwata, Koushi; Nii, Takuya; Nakata, Hikaru; Tsubotani, Yoshie; Inoue, Yasuhide

    2015-01-01

    Olanexidine gluconate [1-(3,4-dichlorobenzyl)-5-octylbiguanide gluconate] (development code OPB-2045G) is a new monobiguanide compound with bactericidal activity. In this study, we assessed its spectrum of bactericidal activity and mechanism of action. The minimal bactericidal concentrations of the compound for 30-, 60-, and 180-s exposures were determined with the microdilution method using a neutralizer against 320 bacterial strains from culture collections and clinical isolates. Based on the results, the estimated bactericidal olanexidine concentrations with 180-s exposures were 869 μg/ml for Gram-positive cocci (155 strains), 109 μg/ml for Gram-positive bacilli (29 strains), and 434 μg/ml for Gram-negative bacteria (136 strains). Olanexidine was active against a wide range of bacteria, especially Gram-positive cocci, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, and had a spectrum of bactericidal activity comparable to that of commercial antiseptics, such as chlorhexidine and povidone-iodine. In vitro experiments exploring its mechanism of action indicated that olanexidine (i) interacts with the bacterial surface molecules, such as lipopolysaccharide and lipoteichoic acid, (ii) disrupts the cell membranes of liposomes, which are artificial bacterial membrane models, (iii) enhances the membrane permeability of Escherichia coli, (iv) disrupts the membrane integrity of S. aureus, and (v) denatures proteins at relatively high concentrations (≥160 μg/ml). These results indicate that olanexidine probably binds to the cell membrane, disrupts membrane integrity, and its bacteriostatic and bactericidal effects are caused by irreversible leakage of intracellular components. At relatively high concentrations, olanexidine aggregates cells by denaturing proteins. This mechanism differs slightly from that of a similar biguanide compound, chlorhexidine. PMID:25987609

  10. The bactericidal effect of surface micro-discharge plasma under different ambient conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, T; Zimmermann, J L; Morfill, G E, E-mail: tshimizu@mpe.mpg.de [Max-Planck Institute for Extraterrestrial Physics, Giessenbachstr., 85748 Garching (Germany)

    2011-02-15

    A series of experiments on the bactericidal properties of plasmas using a surface micro-discharge (SMD) device in an atmosphere under different ambient temperatures and humidities was carried out. This plasma dispenser was developed for use as a disinfection system in private and public places (hospitals, medical practices, etc). The bactericidal effect is due to the interplay of the plasma and the chemical products produced via interactions with O{sub 2}/N{sub 2} and H{sub 2}O vapour in air. To use this device in different countries and therefore under various ambient conditions, it is important to understand its behaviour and efficiency, especially with respect to air temperature and humidity. The experimental results obtained in this study show that the bactericidal properties of the SMD plasma dispenser are not sensitive to the different temperatures and humidities.

  11. Bactericidal and cytotoxic effects of Erythrina fusca leaves aquadest extract

    Directory of Open Access Journals (Sweden)

    Janti Sudiono

    2013-03-01

    Full Text Available Background: Empirically, Erythrina fusca has been used as traditional herb for its antibacterial and antiinflammation properties. Periodontal disease is one of the most oral infectious diseases with microorganism predominated as the contributing factors. Porphyromonas gingivalis (P. gingivalis is one of the main bacteria pathogen found in periodontal diseases. Purpose: The purpose of this study was to examine the bactericidal effect of Erythrina fusca Leaves Aquadest Extract (EFLAE at various concentrations on P. gingivalis and cytotoxic effect on fibroblast. Methods: Pure P. gingivalis was cultured in Brain Heart Infusion (BHI medium for 24 hours with or without various concentrations of treatment of EFLAE. Calculation and statistical analysis of remaining bacteria were performed by inhibitory zone method to evaluate the EFLAE bactericidal effect and compared to chlorhexidine as positive control. To evaluate the cytotoxic effect, NIH 3T3 cells were cultured in Dulbecco’s Modification of Eagle’s Medium (DMEM containing of 10% fetal bovine serum (FBS and 1% penicillin-streptomycin, pH 7.2, in 5% CO2, and stored in humidified incubator under temperature 370 C. Cells were treated with/without various concentrations of EFLAE for 48 hours. The viable cells were then counted using 3-(4,5- Dimethylthiazol-2-yl-2,5 diphenyl tetrazodium bromide (MTT method. Results: EFLAE have bactericidal effect on P. gingivalis in a concentration dependent manner starting from 78%. The concentration of 90% EFLAE had stronger bactericidal effect (35.004 ± 1.546 than those of chlorhexidine as positive control (32.313 ± 1.619. One-way ANOVA showed significant bactericidal effect differences among concentrations of EFLAE and chlorhexidine (p<0.05 while Tuckey HSD test showed significant difference only between lower concentration of EFLAE (78%, 79% and chlorhexidine. With the highest concentration of EFLAE (100% applied in the bactericidal test, no cytotoxic effect

  12. Bactericidal effect of starch-stabilized zero-valent iron nanoparticles on Escherichia coli

    Directory of Open Access Journals (Sweden)

    Mohammad Mosaferi

    2016-01-01

    Conclusion: The present study showed that nonstabilized Fe 0 nanoparticles have higher bactericidal efficiency than that of S-NZVI. This investigation also suggests that NZVI can be used as an effective and strong agent for antimicrobial applications.

  13. Nanoparticles as Efflux Pump and Biofilm Inhibitor to Rejuvenate Bactericidal Effect of Conventional Antibiotics

    Science.gov (United States)

    Gupta, Divya; Singh, Ajeet; Khan, Asad U.

    2017-07-01

    The universal problem of bacterial resistance to antibiotic reflects a serious threat for physicians to control infections. Evolution in bacteria results in the development of various complex resistance mechanisms to neutralize the bactericidal effect of antibiotics, like drug amelioration, target modification, membrane permeability reduction, and drug extrusion through efflux pumps. Efflux pumps acquire a wide range of substrate specificity and also the tremendous efficacy for drug molecule extrusion outside bacterial cells. Hindrance in the functioning of efflux pumps may rejuvenate the bactericidal effect of conventional antibiotics. Efflux pumps also play an important role in the exclusion or inclusion of quorum-sensing biomolecules responsible for biofilm formation in bacterial cells. This transit movement of quorum-sensing biomolecules inside or outside the bacterial cells may get interrupted by impeding the functioning of efflux pumps. Metallic nanoparticles represent a potential candidate to block efflux pumps of bacterial cells. The application of nanoparticles as efflux pump inhibitors will not only help to revive the bactericidal effect of conventional antibiotics but will also assist to reduce biofilm-forming capacity of microbes. This review focuses on a novel and fascinating application of metallic nanoparticles in synergy with conventional antibiotics for efflux pump inhibition.

  14. Corneal epithelial wound healing and bactericidal effect of conditioned medium from human uterine cervical stem cells.

    Science.gov (United States)

    Bermudez, Maria A; Sendon-Lago, Juan; Eiro, Noemi; Treviño, Mercedes; Gonzalez, Francisco; Yebra-Pimentel, Eva; Giraldez, Maria Jesus; Macia, Manuel; Lamelas, Maria Luz; Saa, Jorge; Vizoso, Francisco; Perez-Fernandez, Roman

    2015-01-22

    To evaluate the effect of conditioned medium from human uterine cervical stem cells (CM-hUCESCs) on corneal epithelial healing in a rat model of dry eye after alkaline corneal epithelial ulcer. We also tested the bactericidal effect of CM-hUCESCs. Dry eye was induced in rats by extraocular lacrimal gland excision, and corneal ulcers were produced using NaOH. Corneal histologic evaluation was made with hematoxylin-eosin (H&E) staining. Real-time PCR was used to evaluate mRNA expression levels of proinflammatory cytokines. We also studied the bactericidal effect of CM-hUCESCs in vitro and on infected corneal contact lenses (CLs) using Escherichia coli and Staphylococcus epidermidis bacteria. In addition, in order to investigate proteins from CM-hUCESCs that could mediate these effects, we carried out a human cytokine antibody array. After injury, dry eyes treated with CM-hUCESCs significantly improved epithelial regeneration and showed reduced corneal macrophage inflammatory protein-1 alpha (MIP-1α) and TNF-α mRNA expression as compared to untreated eyes and eyes treated with culture medium or sodium hyaluronate ophthalmic drops. In addition, we found in CM-hUCESCs high levels of proteins, such as tissue inhibitors of metalloproteinases 1 and 2, fibroblast growth factor 6 and 7, urokinase receptor, and hepatocyte growth factor, that could mediate these effects. In vitro, CM-hUCESCs showed a clear bactericidal effect on both E. coli and S. epidermidis and CLs infected with S. epidermidis. Analyses of CM-hUCESCs showed elevated levels of proteins that could be involved in the bactericidal effect, such as the chemokine (C-X-C motif) ligands 1, 6, 8, 10, and the chemokine (C-C motif) ligands 5 and 20. Treatment with CM-hUCESCs improved wound healing of alkali-injured corneas and showed a strong bactericidal effect on CLs. Patients using CLs and suffering from dry eye, allergies induced by commercial solutions, or small corneal injuries could benefit from this treatment

  15. Bactericidal effects of triclosan in soap both in vitro and in vivo.

    Science.gov (United States)

    Kim, S A; Moon, H; Lee, K; Rhee, M S

    2015-12-01

    On December 2013, the US FDA proposed a rule stating that manufacturers must provide data to demonstrate that antibacterial soap is more effective than plain soap or water. The objective of the present study was to examine the in vitro and in vivo bactericidal effect of triclosan (the most widely used antiseptic agent in soap) in soap. Twenty bacterial strains (proposed by the FDA) were exposed to plain and antibacterial soaps (the same formulation as plain soap, but containing 0.3% triclosan) for 20 s at 22°C (room temperature) and 40°C (warm temperature). The temperature and time were selected to simulate the hand washing conditions and procedures used by consumers. The triclosan concentration of 0.3% is the maximum allowed by law. The decontamination efficacy of plain soap and antibacterial soap was also examined in vivo: the hands of volunteers were artificially inoculated with Serratia marcescens. There was no significant difference (P > 0.05) in bactericidal activity between plain soap and antibacterial soap at either test temperature. However, antibacterial soap showed significantly greater bactericidal effects after 9 h. These results suggest that although triclosan-containing soap does have antibacterial activity, the effects are not apparent during the short time required for hand washing. Antibacterial soap containing triclosan (0.3%) was no more effective than plain soap at reducing bacterial contamination when used under 'real-life' conditions. The present study provides practical information that may prove useful for both industry and governments. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  16. Bactericidal action of cold atmospheric plasma in solution

    International Nuclear Information System (INIS)

    Boxhammer, V; Morfill, G E; Shimizu, T; Klämpfl, T; Li, Y-F; Köritzer, J; Zimmermann, J L; Jokipii, J R; Schlegel, J

    2012-01-01

    In this study different influences on the bactericidal effect of cold atmospheric plasma (CAP) were investigated intensively. In detail, different initial densities of Escherichia coli cells and different treatment times of up to 8 min were studied. The results show that up to densities of 10 5 cells per 20 μl high reduction rates of up to 5 log can be achieved in less than 3 min of CAP application. In contrast, for higher cell densities almost no reduction was measured for CAP treatment times of up to 8 min. To understand this data in detail, a theoretical model was developed. This model starts from the premise that bacteria are able to some degree to neutralize reactive species and that accordingly the bactericidal effect depends on the bacterial concentration. A further purpose of this study was to analyze the contribution of reactive oxygen and also reactive nitrogen species—produced by the CAP—to the bactericidal effect. We therefore measured nitrites, nitrates and hydrogen peroxide—products of chemical reactions between the species produced by the CAP and the liquid. The evidence of nitric oxide (NO) uptake in bacteria and the corresponding reference experiments with hydrogen peroxide and a chemical NO donor clearly show that the bactericidal effect of CAP is related to a combination of oxidative and nitrosative effects. (paper)

  17. Morphological bactericidal fast-acting effects of peracetic acid, a high-level disinfectant, against Staphylococcus aureus and Pseudomonas aeruginosa biofilms in tubing.

    Science.gov (United States)

    Chino, T; Nukui, Y; Morishita, Y; Moriya, K

    2017-01-01

    The bactericidal effect of disinfectants against biofilms is essential to reduce potential endoscopy-related infections caused by contamination. Here, we investigated the bactericidal effect of a high-level disinfectant, peracetic acid (PAA), against Staphylococcus aureus and Pseudomonas aeruginosa biofilm models in vitro. S. aureus and P. aeruginosa biofilms were cultured at 35 °C for 7 days with catheter tubes. The following high-level disinfectants (HLDs) were tested: 0.3% PAA, 0.55% ortho-phthalaldehyde (OPA), and 2.0% alkaline-buffered glutaraldehyde (GA). Biofilms were exposed to these agents for 1-60 min and observed after 5 min and 30 min by transmission and scanning electron microscopy. A Student's t test was performed to compare the exposure time required for bactericidal effectiveness of the disinfectants. PAA and GA were active within 1 min and 5 min, respectively, against S. aureus and P. aeruginosa biofilms. OPA took longer than 10 min and 30 min to act against S. aureus and P. aeruginosa biofilms, respectively ( p  < 0.01). Treatment with PAA elicited changes in cell shape after 5 min and structural damage after 30 min. Amongst the HLDs investigated, PAA elicited the most rapid bactericidal effects against both biofilms. Additionally, treatment with PAA induced morphological alterations in the in vitro biofilm models, suggesting that PAA exerts fast-acting bactericidal effects against biofilms associated with endoscopy-related infections. These findings indicate that the exposure time for bactericidal effectiveness of HLDs for endoscope reprocessing in healthcare settings should be reconsidered.

  18. Morphological bactericidal fast-acting effects of peracetic acid, a high-level disinfectant, against Staphylococcus aureus and Pseudomonas aeruginosa biofilms in tubing

    Directory of Open Access Journals (Sweden)

    T. Chino

    2017-12-01

    Full Text Available Abstract Background The bactericidal effect of disinfectants against biofilms is essential to reduce potential endoscopy-related infections caused by contamination. Here, we investigated the bactericidal effect of a high-level disinfectant, peracetic acid (PAA, against Staphylococcus aureus and Pseudomonas aeruginosa biofilm models in vitro. Methods S. aureus and P. aeruginosa biofilms were cultured at 35 °C for 7 days with catheter tubes. The following high-level disinfectants (HLDs were tested: 0.3% PAA, 0.55% ortho-phthalaldehyde (OPA, and 2.0% alkaline-buffered glutaraldehyde (GA. Biofilms were exposed to these agents for 1–60 min and observed after 5 min and 30 min by transmission and scanning electron microscopy. A Student’s t test was performed to compare the exposure time required for bactericidal effectiveness of the disinfectants. Results PAA and GA were active within 1 min and 5 min, respectively, against S. aureus and P. aeruginosa biofilms. OPA took longer than 10 min and 30 min to act against S. aureus and P. aeruginosa biofilms, respectively (p < 0.01. Treatment with PAA elicited changes in cell shape after 5 min and structural damage after 30 min. Conclusions Amongst the HLDs investigated, PAA elicited the most rapid bactericidal effects against both biofilms. Additionally, treatment with PAA induced morphological alterations in the in vitro biofilm models, suggesting that PAA exerts fast-acting bactericidal effects against biofilms associated with endoscopy-related infections. These findings indicate that the exposure time for bactericidal effectiveness of HLDs for endoscope reprocessing in healthcare settings should be reconsidered.

  19. [Bactericidal activity of serum and chemotherapy in sensitive and resistant exciter (author's transl)].

    Science.gov (United States)

    Eyer, H; Metz, H; Preac-Mursic, V

    1975-11-21

    Comparing examinations with Ampicillin sensitive and resistant bacteria-strains show that the bactericidal activity of serum is dependent on the bacteria-strains, on the Ampicillin sensitivity of the particular exciter and on the number of bacteria/ml (germ count). Bactericide effect could always be obtained with sensitive strains as a result of additional chemotherapy. With several resistant strains a bactericide effect could not be obtained in this case the continuous optimal Ampicillin addition was the decisive factor. Because of the extremely complicated process of the bactericide one should not make general conclusions from the individual experimental results.

  20. Bactericidal effect of colistin on planktonic Pseudomonas aeruginosa is independent of hydroxyl radical formation

    DEFF Research Database (Denmark)

    Brochmann, Rikke Prejh; Toft, Anders; Ciofu, Oana

    2014-01-01

    The bactericidal effect of several major types of antibiotics has recently been demonstrated to be dependent on the formation of toxic amounts of hydroxyl radicals (OH·) resulting from oxidative stress in metabolically active cells. Since killing by the antimicrobial peptide colistin does...... not require bacterial metabolic activity, we tested whether the bactericidal effect of colistin depends on the formation of OH·. In Pseudomonas aeruginosa cultures, OH-mediated killing by ciprofloxacin was demonstrated by decreased bacterial survival and induction of 3'-(p-hydroxyphenyl) fluorescein (HPF......) fluorescence. OH·-mediated killing by ciprofloxacin was further confirmed by rescue of cells and reduction of HPF fluorescence due to prevention of OH· accumulation by scavenging with thiourea, by chelating with dipyridyl, by decreasing metabolism as well as by anoxic growth. In contrast, no formation of OH...

  1. Bactericidal Effect of Photolysis of H2O2 in Combination with Sonolysis of Water via Hydroxyl Radical Generation.

    Science.gov (United States)

    Sheng, Hong; Nakamura, Keisuke; Kanno, Taro; Sasaki, Keiichi; Niwano, Yoshimi

    2015-01-01

    The bactericidal effect of hydroxyl radical (·OH) generated by combination of photolysis of hydrogen peroxide (H2O2) and sonolysis of water was examined under the condition in which the yield of ·OH increased additively when H2O2 aqueous solution was concomitantly irradiated with laser and ultrasound. The suspension of Staphylococcus aureus mixed with the different concentrations of H2O2 was irradiated simultaneously with a laser light (wavelength: 405 nm, irradiance: 46 and 91 mW/cm2) and ultrasound (power: 30 w, frequency: 1.65 MHz) at 20 ± 1°C of the water bulk temperature for 2 min. The combination of laser and ultrasound irradiation significantly reduced the viable bacterial count in comparison with the laser irradiation of H2O2 alone. By contrast, the ultrasound irradiation alone exerted almost no bactericidal effect. These results suggested that the combination effect of photolysis of H2O2 and sonolysis of water on bactericidal activity was synergistic. A multi-way analysis of variance also revealed that the interaction of H2O2 concentration, laser power and ultrasound irradiation significantly affected the bactericidal activity. Since the result of oxidative DNA damage evaluation demonstrated that the combination of laser and ultrasound irradiation significantly induced oxidative damage of bacterial DNA in comparison with the laser irradiation of H2O2 alone, it was suggested that the combination effect of photolysis of H2O2 and sonolysis of water on bactericidal activity would be exerted via oxidative damage of cellular components such as DNA.

  2. Bactericidal Effect of Photolysis of H2O2 in Combination with Sonolysis of Water via Hydroxyl Radical Generation.

    Directory of Open Access Journals (Sweden)

    Hong Sheng

    Full Text Available The bactericidal effect of hydroxyl radical (·OH generated by combination of photolysis of hydrogen peroxide (H2O2 and sonolysis of water was examined under the condition in which the yield of ·OH increased additively when H2O2 aqueous solution was concomitantly irradiated with laser and ultrasound. The suspension of Staphylococcus aureus mixed with the different concentrations of H2O2 was irradiated simultaneously with a laser light (wavelength: 405 nm, irradiance: 46 and 91 mW/cm2 and ultrasound (power: 30 w, frequency: 1.65 MHz at 20 ± 1°C of the water bulk temperature for 2 min. The combination of laser and ultrasound irradiation significantly reduced the viable bacterial count in comparison with the laser irradiation of H2O2 alone. By contrast, the ultrasound irradiation alone exerted almost no bactericidal effect. These results suggested that the combination effect of photolysis of H2O2 and sonolysis of water on bactericidal activity was synergistic. A multi-way analysis of variance also revealed that the interaction of H2O2 concentration, laser power and ultrasound irradiation significantly affected the bactericidal activity. Since the result of oxidative DNA damage evaluation demonstrated that the combination of laser and ultrasound irradiation significantly induced oxidative damage of bacterial DNA in comparison with the laser irradiation of H2O2 alone, it was suggested that the combination effect of photolysis of H2O2 and sonolysis of water on bactericidal activity would be exerted via oxidative damage of cellular components such as DNA.

  3. The effect of long-term storage on the physiochemical and bactericidal properties of electrochemically activated solutions.

    Science.gov (United States)

    Robinson, Gareth; Thorn, Robin; Reynolds, Darren

    2012-12-24

    Electrochemically activated solutions (ECAS) are generated by electrolysis of NaCl solutions, and demonstrate broad spectrum antimicrobial activity and high environmental compatibility. The biocidal efficacy of ECAS at the point of production is widely reported in the literature, as are its credentials as a "green biocide." Acidic ECAS are considered most effective as biocides at the point of production and ill suited for extended storage. Acidic ECAS samples were stored at 4 °C and 20 °C in glass and polystyrene containers for 398 days, and tested for free chlorine, pH, ORP and bactericidal activity throughout. ORP and free chlorine (mg/L) in stored ECAS declined over time, declining at the fastest rate when stored at 20 °C in polystyrene and at the slowest rate when stored at 4 °C in glass. Bactericidal efficacy was also affected by storage and ECAS failed to produce a 5 log(10) reduction on five occasions when stored at 20 °C. pH remained stable throughout the storage period. This study represents the longest storage evaluation of the physiochemical parameters and bactericidal efficacy of acidic ECAS within the published literature and reveals that acidic ECAS retain useful bactericidal activity for in excess of 12 months, widening potential applications.

  4. The Effect of Long-Term Storage on the Physiochemical and Bactericidal Properties of Electrochemically Activated Solutions

    Directory of Open Access Journals (Sweden)

    Gareth Robinson

    2012-12-01

    Full Text Available Electrochemically activated solutions (ECAS are generated by electrolysis of NaCl solutions, and demonstrate broad spectrum antimicrobial activity and high environmental compatibility. The biocidal efficacy of ECAS at the point of production is widely reported in the literature, as are its credentials as a “green biocide.” Acidic ECAS are considered most effective as biocides at the point of production and ill suited for extended storage. Acidic ECAS samples were stored at 4 °C and 20 °C in glass and polystyrene containers for 398 days, and tested for free chlorine, pH, ORP and bactericidal activity throughout. ORP and free chlorine (mg/L in stored ECAS declined over time, declining at the fastest rate when stored at 20 °C in polystyrene and at the slowest rate when stored at 4 °C in glass. Bactericidal efficacy was also affected by storage and ECAS failed to produce a 5 log10 reduction on five occasions when stored at 20 °C. pH remained stable throughout the storage period. This study represents the longest storage evaluation of the physiochemical parameters and bactericidal efficacy of acidic ECAS within the published literature and reveals that acidic ECAS retain useful bactericidal activity for in excess of 12 months, widening potential applications.

  5. Bactericidal catechins damage the lipid bilayer.

    Science.gov (United States)

    Ikigai, H; Nakae, T; Hara, Y; Shimamura, T

    1993-04-08

    The mode of antibacterial action of, the green tea (Camellia sinensis) extracts, (-)-epigallocatechin gallate (EGCg) and (-)-epicatechin (EC) was investigated. Strong bactericidal EGCg caused leakage of 5,6-carboxyfluorescein from phosphatidylcholine liposomes (PC), but EC with very weak bactericidal activity caused little damage to the membrane. Phosphatidylserine and dicetyl phosphate partially protected the membrane from EGCg-mediated damage when reconstituted into the liposome membrane with PC. EGCg, but not EC, caused strong aggregation and NPN-fluorescence quenching of PC-liposomes and these actions were markedly lowered in the presence of negatively charged lipids. These results show that bactericidal catechins primarily act on and damage bacterial membranes. The observation that Gram-negative bacteria are more resistant to bactericidal catechins than Gram-positive bacteria can be explained to some extent by the presence of negatively charged lipopolysaccharide.

  6. Modification of TiO(2) nanotube surfaces by electro-spray deposition of amoxicillin combined with PLGA for bactericidal effects at surgical implantation sites.

    Science.gov (United States)

    Lee, Jung-Hwan; Moon, Seung-Kyun; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2013-01-01

    To fabricate the antibiotic-releasing coatings on TiO(2) nanotube surfaces for wide applications of implant and bone plate in medical and dental surgery, the optimal deposition time of amoxicillin/PLGA solution simultaneously performing non-toxicity and a high bactericidal effect for preventing early implant failures was found. FE-SEM, ESD and FT-IR were used for confirming deposition of amoxicillin/PLGA on the TiO(2) surface. Also, the elution of amoxicillin/PLGA in a TiO(2) nanotube surface was measured by a UV-VIS spectrophotometer. The bactericidal effect of amoxicillin on the TiO(2) nanotube surface was evaluated by using Staphylococcus aureus (S. aureus). The cytotoxicity and cell proliferation were observed by WST assay using MC3T3-E1 osteoblast cells. The results indicated that the TiO(2) nanotube surface controlled by electro-spray deposition time with amoxicillin/PLGA solution could provide a high bactericidal effect against S. aureus by the bactericidal effect of amoxicillin, as well as good osteoblast cell proliferation at the TiO(2) nanotube surface without toxicity. This study used electro-spray deposition (ESD) methodology to obtain amoxicillin deposition in nanotube structures of TiO(2) and found the optimal deposition time of amoxicillin/PLGA solution simultaneously performing non-toxicity and a high bactericidal effect for preventing early implant failures.

  7. The bactericidal effect of carbon nanotube/agar composites irradiated with near-infrared light on Streptococcus mutans

    Energy Technology Data Exchange (ETDEWEB)

    Akasaka, Tsukasa, E-mail: akasaka@den.hokudai.ac.jp [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan); Matsuoka, Makoto [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan); Hashimoto, Takeshi [Meijo Nano Carbon Co. Ltd., Otsubashi bldg. 4F, 3-4-10 Marunouchi, Naka-ku, Nagoya 460-0002 (Japan); Abe, Shigeaki; Uo, Motohiro; Watari, Fumio [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan)

    2010-10-15

    Dental caries are mainly associated with oral pathogens, and Streptococcus mutans is a primary cariogenic organism. Many methods have been established to eliminate S. mutans from the oral cavity. This study aimed to evaluate the effect of carbon nanotube (CNT)/agar composites irradiated with near-infrared (NIR) light on S. mutans, as a potential photothermal antimicrobial nanotherapy. A colony-forming unit assay clearly showed that CNT/agar composites attain bactericidal activity after NIR light irradiation; this bactericidal activity is higher than that of graphite (GP)/agar and activated carbon (AC)/agar composites. Furthermore, it was observed that longer irradiation times immobilized S. mutans in the CNT/agar composite.

  8. The bactericidal effect of carbon nanotube/agar composites irradiated with near-infrared light on Streptococcus mutans

    International Nuclear Information System (INIS)

    Akasaka, Tsukasa; Matsuoka, Makoto; Hashimoto, Takeshi; Abe, Shigeaki; Uo, Motohiro; Watari, Fumio

    2010-01-01

    Dental caries are mainly associated with oral pathogens, and Streptococcus mutans is a primary cariogenic organism. Many methods have been established to eliminate S. mutans from the oral cavity. This study aimed to evaluate the effect of carbon nanotube (CNT)/agar composites irradiated with near-infrared (NIR) light on S. mutans, as a potential photothermal antimicrobial nanotherapy. A colony-forming unit assay clearly showed that CNT/agar composites attain bactericidal activity after NIR light irradiation; this bactericidal activity is higher than that of graphite (GP)/agar and activated carbon (AC)/agar composites. Furthermore, it was observed that longer irradiation times immobilized S. mutans in the CNT/agar composite.

  9. Combined treatment of UVA irradiation and antibiotics induces greater bactericidal effects on Vibrio parahaemolyticus.

    Science.gov (United States)

    Hou, Yanfei; Nakahashi, Mutsumi; Mawatari, Kazuaki; Shimohata, Takaaki; Uebanso, Takashi; Harada, Yumi; Tsunedomi, Akari; Emoto, Takahiro; Akutagawa, Masatake; Kinouchi, Yohsuke; Takahashi, Akira

    2016-01-01

    The presence of antibiotics in the environment and their subsequent impact on the development of multi-antibiotic resistant bacteria has raised concerns globally. Consequently, much research is focused on a method to produce a better disinfectant. We have established a disinfectant system using UVA-LED that inactivates pathogenic bacteria. We assessed the bactericidal efficiency of a combination of UVA-LED and antibiotics against Vibrio parahaemolyticus. Combined use of antibiotic drugs and UVA irradiation was more bactericidal than UVA irradiation or antibacterial drugs alone. The bactericidal synergy was observed at low concentrations of each drug that are normally unable to kill the bacteria. This combination has the potential to become a sterilization technology.

  10. The stability of complement-mediated bactericidal activity in human serum against Salmonella.

    Directory of Open Access Journals (Sweden)

    Colette M O'Shaughnessy

    Full Text Available The complement cascade includes heat-labile proteins and care is required when handling serum in order to preserve its functional integrity. We have previously used a whole human serum bactericidal assay to show that antibody and an intact complement system are required in blood for killing of invasive isolates of Salmonella. The aim of the present study was to evaluate the conditions under which human serum can be stored and manipulated while maintaining complement integrity. Serum bactericidal activity against Salmonella was maintained for a minimum of 35 days when stored at 4°C, eight days at 22°C and 54 hours at 37°C. Up to three freeze-thaw cycles had no effect on the persistence of bactericidal activity and hemolytic complement assays confirmed no effect on complement function. Delay in the separation of serum for up to four days from clotted blood stored at 22°C did not affect bactericidal activity. Dilution of serum resulted in an increased rate of loss of bactericidal activity and so serum should be stored undiluted. These findings indicate that the current guidelines concerning manipulation and storage of human serum to preserve complement integrity and function leave a large margin for safety with regards to bactericidal activity against Salmonella. The study provides a scheme for determining the requirements for serum handling in relation to functional activity of complement in other systems.

  11. Bactericide for sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Shklyar, T F; Anoshina, G M; Blokhin, V Ye; Kisarrev, Ye L; Novikovsa, G M

    1981-01-01

    The aim of the invention is to find a bactericide for sulfate-reducing bacteria of oil fields in Western Siberia in order to suppress the biocorrosive activity on oil industry equipment. This goal is achieved by using M-nitroacetanylide as the bactericide of sulfate-reducing bacteria. This agent suppresses the activity of a stored culture of sulfate-reducing bacteria that comes from industrial waste waters injection wells of the Smotlor oil field.

  12. Blood bactericidal activity in Hiroshima subjects

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, J W; Hamilton, H B

    1961-03-07

    A simple screening method for blood bactericidal activity was developed for study of irradiated atomic bomb survivors and nonirradiated subjects in Hiroshima. Blood bactericidal activity was found to be a relatively constant biological phenomenon in all subjects studied. No differences in activity were detected in relationship to radiation exposure in 1945. 17 references, 6 tables.

  13. [Bactericidal activity of colloidal silver against grampositive and gramnegative bacteria].

    Science.gov (United States)

    Afonina, I A; Kraeva, L A; Tseneva, G Ia

    2010-01-01

    It was shown that colloidal silver solution prepared in cooperation with the A. F. Ioffe Physical Technical Institute of the Russian Academy of Sciences, had significant bactericidal activity. Stable bactericidal effect on gramnegative microorganisms was observed after their 2-hour exposition in the solution of colloidal silver at a concentration of 10 ppm. Grampositive capsule-forming microorganisms were less susceptible to the colloidal silver solution: their death was observed after the 4-hour exposition in the solution.

  14. Bactericidal effects of plasma-modified surface chemistry of silicon nanograss

    International Nuclear Information System (INIS)

    Ostrikov, Kola; Macgregor-Ramiasa, Melanie; Cavallaro, Alex; Ostrikov, Kostya; Vasilev, Krasimir

    2016-01-01

    The surface chemistry and topography of biomaterials regulate the adhesion and growth of microorganisms in ways that are still poorly understood. Silicon nanograss structures prepared via inductively coupled plasma etching were coated with plasma deposited nanometer-thin polymeric films to produce substrates with controlled topography and defined surface chemistry. The influence of surface properties on Staphylococcus aureus proliferation is demonstrated and explained in terms of nanograss substrate wetting behaviour. With the combination of the nanograss topography; hydrophilic plasma polymer coatings enhanced antimicrobial activity while hydrophobic coatings reduced it. This study advances the understanding of the effects of surface wettability on the bactericidal properties of reactive nano-engineered surfaces. (paper)

  15. PREPARATION OF TITANIA SOL-GEL COATINGS CONTAINING SILVER IN VARIOUS FORMS AND MEASURING OF THEIR BACTERICIDAL EFFECTS AGAINST E. COLI

    Directory of Open Access Journals (Sweden)

    Diana Horkavcova

    2015-09-01

    Full Text Available The work describes titania coatings containing various forms of silver applied on a titanium substrate by a dip-coating sol-gel technique. Silver was added into the basic titania sol in form of colloid particles of Ag, crystals of AgNO3, particles of AgI, particles of Ag3PO4 and Ag3PO4 developed in situ (in the sol by reaction of AgNO3 with added calcium phosphate (brushite or monetite. Mechanically and chemically treated titanium substrates were dipped at a constant rate into individual types of sols. Subsequently, they were slowly fired. The fired coatings contained microcracks. All over the surface there were evenly distributed spherical nanoparticles of silver (Ag, AgNO3 or microcrystals of AgI and Ag3PO4. The prepared coatings were tested under static conditions for their bactericidal effects against gram-negative bacteria Escherichia coli (E. coli. The coated substrates were immersed into a suspension of E. coli in physiological solution for 24 and 4 hours. The basic titania coatings with no silver demonstrated no bactericidal properties. Very good bactericidal effect against E. coli in both types of bactericidal test showed the titania coatings with AgNO3, Ag3PO4 crystals and Ag3PO4 developed in situ.

  16. Bactericidal antibiotics induce programmed metabolic toxicity

    Directory of Open Access Journals (Sweden)

    Aislinn D. Rowan

    2016-03-01

    Full Text Available The misuse of antibiotics has led to the development and spread of antibiotic resistance in clinically important pathogens. These resistant infections are having a significant impact on treatment outcomes and contribute to approximately 25,000 deaths in the U.S. annually. If additional therapeutic options are not identified, the number of annual deaths is predicted to rise to 317,000 in North America and 10,000,000 worldwide by 2050. Identifying therapeutic methodologies that utilize our antibiotic arsenal more effectively is one potential way to extend the useful lifespan of our current antibiotics. Recent studies have indicated that modulating metabolic activity is one possible strategy that can impact the efficacy of antibiotic therapy. In this review, we will address recent advances in our knowledge about the impacts of bacterial metabolism on antibiotic effectiveness and the impacts of antibiotics on bacterial metabolism. We will particularly focus on two studies, Lobritz, et al. (PNAS, 112(27: 8173-8180 and Belenky et al. (Cell Reports, 13(5: 968–980 that together demonstrate that bactericidal antibiotics induce metabolic perturbations that are linked to and required for bactericidal antibiotic toxicity.

  17. Influence of Rifampin Therapy on Serum Bactericidal Activity in the Presence of Cloxacillin and Vancomycin

    Directory of Open Access Journals (Sweden)

    Andrew MR Mackenzie

    1990-01-01

    Full Text Available In this study the effect of rifampin on serum inhibitory and serum bactericidal titres was examined. Sera were prepared from pooled human serum to contain vancomycin (10 mg/L, cloxacillin (5 mg/L or rifampin (1 mg/L, and the combinations cloxacillin/rifampin and vancomycin/rifampin. These five sera were tested by a microtitre method for serum inhibitory power and serum bactericidal titre against 11 strains of Staphylococcus aureus. A 48 h incubation period was required to detect full colony growth for subculture plates. It was found with all strains that the effect of the addition of rifampin to the other two antibiotics was to increase the serum inhibitory power, lower the serum bactericidal titre, increase the inhibitory/cidal ratio, and slow colony growth on subculture. In the clinical part of the study it was shown that only three of 38 sera (8% from patients receiving betalactam or vanomycin but not rifampin gave an inhibitory/cidal ratio greater than 8, but that nine of 10 sera (90% from patients receiving rifampin in addition to betalactam or vancomycin gave a ratio greater than 8 (P<0.001. The study verified that the effect of rifampin in serum was to increase inhibitory power and decrease bactericidal titre. The clinical significance of these results is not known and it is suggested that a high ratio of inhibitory to bactericidal titre in the presence of rifampin is to be expected, and that a low bactericidal titre under these circumstances is not necessarily an indication to modify therapy.

  18. Whole-blood phagocytic and bactericidal activities of atomic bomb survivors, Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Sasagawa, Sumiko; Yoshimoto, Yasuhiko; Toyota, Emiko; Neriishi, Shotaro; Yamakido, Michio; Matsuo, Miyo; Hosoda, Yutaka; Finch, S.C.

    1989-04-01

    This in vitro study evaluated the phagocytic and bactericidal activities of leukocytes in aliquots of whole blood from Hiroshima and Nagasaki atomic bomb survivors for Staphylococcus aureus. The data were analyzed by multiple linear regression. Any significant effects of exposure to A-bomb radiation could not be detected for both phagocytic and bactericidal activities of whole blood from A-bomb survivors. In addition, there were no significant effects of age categories, sex or city, except in neutrophil counts. (J.P.N.)

  19. Phagocytic and bactericidal activities of leukocytes in whole blood from atomic bomb survivors

    International Nuclear Information System (INIS)

    Sasagawa, S.; Yoshimoto, Y.; Toyota, E.; Neriishi, S.; Yamakido, M.; Matsuo, M.; Hosoda, Y.; Finch, S.C.

    1990-01-01

    This study evaluated the phagocytic and bactericidal activities of peripheral blood leukocytes from Hiroshima and Nagasaki atomic bomb survivors for Staphylococcus aureus. The data were analyzed by multiple linear regression for age, sex, radiation exposure, city of exposure, and neutrophil counts. No significant radiation effect was observed for either blood phagocytic or bactericidal activities. The only significant variable for these functions was the neutrophil count

  20. Effect of diesel leakage in circulating cooling water system on preponderant bacteria diversity and bactericidal effect of biocides.

    Science.gov (United States)

    Zhong, Huiyun; Liu, Fang; Lu, Jinjin; Yang, Wei; Zhao, Chaocheng

    2015-01-01

    Petroleum products leakage results in adverse effect on the normal operation of a circulating cooling water system. However, relatively little research has been done to explore the effect of petroleum products leakage on circulating cooling water quality and biofilm preponderant bacteria diversity. Also, normal biocides application modes cannot fulfil the need for biofilm control. In this study, diesel oil was used as the experimental subject representing leaking petroleum products; the effect of diesel addition on biofilm preponderant bacteria diversity and the bactericidal effect of chlorine dioxide and tetradecyl dimethyl benzyl ammonium chloride (1427) was investigated. Bacterial community structures were examined by PCR-denaturing gradient gel electrophoresis and PCR cloning of 16S rDNA genes. Except for 100 mg/L diesel, increasing diesel concentration enhanced the biofilm detachment ratio compared with the control test. The microstructure of biofilm samples with 0, 300 and 900 mg/L diesel addition was observed. The species of preponderant bacteria in the biofilm sample with 300 mg/L diesel addition were more and the bacterial distribution was more uniform than those in the biofilm sample with 900 mg/L diesel addition. With ClO2 and 1427 addition, chemical oxygen demand increased, lipid phosphorus and bacterial count first decreased and then remained stable, and the bactericidal ratio first increased and then remained stable. Diesel addition variation has more obvious effect on ClO2 than 1427.

  1. Bactericidal activity of titanium dioxide ultraviolet-induced films

    Energy Technology Data Exchange (ETDEWEB)

    Pleskova, S.N., E-mail: pleskova@mail.ru [Laboratory of Biochemistry and Molecular Biology, Tomsk State University, ave. Lenina 36, Tomsk 634050 (Russian Federation); Golubeva, I.S., E-mail: golubmay@mail.ru [Institute of applied biotechnology of Nizhny Novgorod, Yablonevaya Street 22, Nizhny Novgorod 603093 (Russian Federation); Verevkin, Y.K., E-mail: verevkin@appl.sci-nnov.ru [Institute of applied physics of the Russian Academy of Science, Ul' yanov Street, 46, Nizhny Novgorod 603950 (Russian Federation)

    2016-02-01

    TiO{sub 2} films are used as a self-sterilization surface due to their property to form reactive oxygen species (ROS) when irradiated with ultraviolet light. These ROS attack bacteria and kill them. We present a new way to enhance the bactericidal activity of TiO{sub 2}-films: formation of nanopores on the surface by four-beam high-power laser irradiation. Such surfaces have significantly higher antibacterial activity as compared to conventional TiO{sub 2} surfaces after 15 and 60 min of UV irradiation. Study of the bacterial cell morphology by atomic force microscopy after 60 min irradiation showed that Staphylococcus aureus 956 and Escherichia coli 321–5 undergo significant morphological changes. S. aureus assume atypical elongated shapes after UV treatment alone and swollen forms with protrusions after UV treatment on TiO{sub 2} surface. E. coli exhibit oval or round forms after UV treatment alone, and round forms with small protrusions, and destroyed cells after incubation under UV on the TiO{sub 2} film. - Highlights: • Nanopores on the TiO{sub 2} surface enhance the bactericidal activity of films. • The bactericidal effect of TiO{sub 2} is strain-specific. • The bacterial morphology significantly changes after UV/TiO{sub 2} treatment.

  2. Bactericidal effect of Nd:YAG laser irradiation in endodontics

    Science.gov (United States)

    Aun, Carlos E.; Barberini, Alexandre F.; Camargo, Selma C. C.; Silva Kfouri, Luciana; Lorenzetti Simionato, Maria R.

    1999-05-01

    The success of endodontic therapy is based on the elimination of bacterial colonization from the endodontic system and periapical tissues. Recent studies have been showing the bactericidal effect of laser in root canal treatment. The propose of the study is to evaluate the effect of Nd:YAG laser irradiation in contaminated root canal treatment. The propose of the study is to evaluate the effect of Nd:YAG laser irradiation in contaminated root canals from upper central incisor. For the experiment 12 teeth were selected, respect at the apical third, sterilized, and 10 μm Streptococcus sanguis liquid culture were inoculated in the root canals. The laser test groups were irradiated with Nd:YAG laser at standard setting of 15Hz, 100mj and 1,5 W for 10, 20 and 30 seconds each in slow helicoidal movements from the apex to the top using a 300 micrometers fiber. After the procedure the specimens were placed in Tryptic Soy Agar, the number of colony forming units was evaluated. The experiment showed a significant reduction on viability of Streptococcus sanguis at the respective time of 20 and 30 seconds.

  3. Processing, characterization, and bactericidal activity of undoped and silver-doped vanadium oxides

    Energy Technology Data Exchange (ETDEWEB)

    Tousley, M.E.; Wren, A.W.; Towler, M.R. [Inamori School of Engineering, Alfred University, Alfred, NY 14803 (United States); Mellott, N.P., E-mail: mellott@alfred.edu [Inamori School of Engineering, Alfred University, Alfred, NY 14803 (United States)

    2012-12-14

    Vanadium oxide (V) and silver-doped vanadium oxide (Ag-V) powders were prepared via sol-gel processing. Structural evolution and bactericidal activity was examined as a function of temperature ranging from 250, 350, 450 and 550 Degree-Sign C. Powders were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and Raman spectroscopy. Results from all techniques showed vanadium pentoxide (V{sub 2}O{sub 5}) is the predominant phase regardless of heat treatment temperature or the addition of silver (Ag). XRD analysis suggests Ag is present as AgCl in samples heat treated to 250, 350, and 450 Degree-Sign C and as AgV{sub 6}O{sub 15} at 550 Degree-Sign C. Bactericidal activity was evaluated against Escherichia coli using the agar disk diffusion method considering both Ag-V and undoped, V powders. While the addition of Ag significantly increased bactericidal properties, the specific Ag valency, or crystal structure and morphology formed at higher temperatures, had little effect on functionality. -- Highlights: Black-Right-Pointing-Pointer Vanadium and silver-doped vanadium oxide powders were prepared via sol-gel. Black-Right-Pointing-Pointer Powders were characterized using advanced, complementary structural techniques. Black-Right-Pointing-Pointer Bactericidal activity was evaluated against E. coli. Black-Right-Pointing-Pointer Both vanadium and silver doped vanadium oxide show bactericidal activity.

  4. Selenium-mediated protection in reversing the sensitivity of bacterium to the bactericidal antibiotics.

    Science.gov (United States)

    Li, Zhonglei; Tan, Jun; Shao, Lei; Dong, Xiaojing; Ye, Richard D; Chen, Daijie

    2017-05-01

    Inducing production of damaging reactive oxygen species (ROS) is an important criterion to distinguish the bactericidal antibiotics from bacteriostatic antibiotics. Selenoenzymes were generally recognized to be a powerful antioxidant capable of scavenging free radicals, protecting the cells from the harmful effects of ROS. Therefore, the present study was carried out to investigate the selenium (Se)-mediated protection in reversing antibiotic sensitivity and the role of selenoenzymes in alleviating the negative effects of oxidative stress. The cellular antioxidant activity of Se-enriched bacteria was analyzed, as well as intracellular ROS production and elimination when Se-enriched bacteria in the presence of various antibiotics. Compared to complete inhibition of the parental strain by bactericidal antibiotics, it only exhibited slight and reversible inhibition of Se-enriched Escherichia coli ATCC25922 and Staphylococcus aureus ATCC25923 at the same conditions, which indicated that intracellular selenium provided substantial protection against antibiotics. ROS generation caused by bactericidal antibiotics was confirmed by fluorescence spectrophotometry using 2', 7'-dichloro- uorescein diacetate (DCFH-DA) as substrate. The time course experiments of pretreatment with selenium showed significant decrease of ROS level at 2h. In summary, the present study provides experimental evidence supporting selenoenzymes has good scavenging effect to ROS and can protect bacteria from oxidative stress injury induced by bactericidal antibiotics. Copyright © 2017 Elsevier GmbH. All rights reserved.

  5. Bactericidal strontium-releasing injectable bone cements based on bioactive glasses.

    Science.gov (United States)

    Brauer, Delia S; Karpukhina, Natalia; Kedia, Gopal; Bhat, Aditya; Law, Robert V; Radecka, Izabela; Hill, Robert G

    2013-01-06

    Strontium-releasing injectable bone cements may have the potential to prevent implant-related infections through the bactericidal action of strontium, while enhancing bone formation in patients suffering from osteoporosis. A melt-derived bioactive glass (BG) series (SiO2–CaO–CaF2–MgO) with 0–50% of calcium substituted with strontium on a molar base were produced. By mixing glass powder, poly(acrylic acid) and water, cements were obtained which can be delivered by injection and set in situ, giving compressive strength of up to 35 MPa. Strontium release was dependent on BG composition with increasing strontium substitution resulting in higher concentrations in the medium. Bactericidal effects were tested on Staphylococcus aureus and Streptococcus faecalis; cell counts were reduced by up to three orders of magnitude over 6 days. Results show that bactericidal action can be increased through BG strontium substitution, allowing for the design of novel antimicrobial and bone enhancing cements for use in vertebroplasty or kyphoplasty for treating osteoporosis-related vertebral compression fractures.

  6. The effects of the bacterial interaction with visible-light responsive titania photocatalyst on the bactericidal performance

    Directory of Open Access Journals (Sweden)

    Cheng Chia-Liang

    2009-01-01

    Full Text Available Abstract Bactericidal activity of traditional titanium dioxide (TiO2 photocatalyst is effective only upon irradiation by ultraviolet light, which restricts the potential applications of TiO2 for use in our living environments. Recently carbon-containing TiO2 was found to be photoactive at visible-light illumination that affords the potential to overcome this problem; although, the bactericidal activity of these photocatalysts is relatively lower than conventional disinfectants. Evidenced from scanning electron microscopy and confocal Raman spectral mapping analysis, we found the interaction with bacteria was significantly enhanced in these anatase/rutile mixed-phase carbon-containing TiO2. Bacteria-killing experiments indicate that a significantly higher proportion of all tested pathogens including Staphylococcus aureus, Shigella flexneri and Acinetobacter baumannii, were eliminated by the new nanoparticle with higher bacterial interaction property. These findings suggest the created materials with high bacterial interaction ability might be a useful strategy to improve the antimicrobial activity of visible-light-activated TiO2.

  7. Bactericidal Antibiotics Do Not Appear To Cause Oxidative Stress in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Feld, Louise; Knudsen, Gitte Maegaard; Gram, Lone

    2012-01-01

    Oxidative stress can be an important contributor to the lethal effect of bactericidal antibiotics in some bacteria, such as Escherichia coli and Staphylococcus aureus. Thus, despite the different target-specific actions of bactericidal antibiotics, they have a common mechanism leading to bacterial...... to cause oxidative stress in L. monocytogenes and propose that this is caused by its noncyclic tricarboxylic acid (TCA) pathway. Hence, in this noncyclic metabolism, there is a decoupling between the antibiotic-mediated cellular requirement for NADH and the induction of TCA enzyme activity, which...

  8. The effect of using a fungicide along with bactericide in the main ...

    African Journals Online (AJOL)

    quarternized compounds), and a fungicide (2-thiocyanomethylthio benzothiazole based) commonly used in Turkish leather industry were chosen. The bactericides were added into the main soaking float with and without different concentrations of fungicide. In each trial, liquor samples were taken at the end of the main ...

  9. Bactericidal efficacy of elevated pH on fish pathogenic and environmental bacteria

    Directory of Open Access Journals (Sweden)

    Clifford E. Starliper

    2013-07-01

    Full Text Available Ship ballast water is a recognized medium for transfer and introductions of nonindigenous species. There is a need for new ballast water treatment methods that effectively and safely eliminate or greatly minimize movements of these species. The present study employed laboratory methods to evaluate the bactericidal efficacy of increased pH (pH 10.0–12.0 for exposure durations of up to 72 h to kill a variety of Gram-negative and Gram-positive bacteria including fish pathogens (Aeromonas spp., Yersinia ruckeri, Edwardsiella ictaluri, Serratia liquefaciens, Carnobacterium sp., other common aquatic-inhabitant bacteria (Serratia marcescens, Pseudomonas fluorescens, Staphylococcus sp., Bacillus sp. and indicators listed in International Maritime Organization D2 Standards; namely, Vibrio cholera (an environmental isolate from fish, Escherichia coli and Enterococcus faecalis. Volumes of 5 N NaOH were added to tryptic soy broth to obtain desired pH adjustments. Viable cells were determined after 0, 4, 12, 24, 48, and 72 h. Initial (0 h cell numbers ranged from 3.40 × 104 cfu/mL for Bacillus sp. to 2.44 × 107 cfu/mL for E. faecalis. The effective endpoints of pH and treatment duration necessary to realize 100% bactericidal effect varied; however, all bacteria tested were killed within 72 h at pH 12.0 or lower. The lowest parameters examined, 4 h at pH 10.0, were bactericidal to V. cholera, E. ictaluri, three of four isolates of E. coli, and (three of four Aeromonas salmonicida subsp. salmonicida. Bactericidal effect was attained at pH 10.0 within 12 h for the other A. salmonicida subsp. salmonicida, and within 24 h for P. fluorescens, and the remaining E. coli.

  10. Bactericidal efficacy of elevated pH on fish pathogenic and environmental bacteria

    Science.gov (United States)

    Starliper, Clifford E.; Watten, Barnaby J.

    2013-01-01

    Ship ballast water is a recognized medium for transfer and introductions of nonindigenous species. There is a need for new ballast water treatment methods that effectively and safely eliminate or greatly minimize movements of these species. The present study employed laboratory methods to evaluate the bactericidal efficacy of increased pH (pH 10.0–12.0) for exposure durations of up to 72 h to kill a variety of Gram-negative and Gram-positive bacteria including fish pathogens (Aeromonas spp., Yersinia ruckeri, Edwardsiella ictaluri, Serratia liquefaciens, Carnobacterium sp.), other common aquatic-inhabitant bacteria (Serratia marcescens, Pseudomonas fluorescens, Staphylococcus sp., Bacillus sp.) and indicators listed in International Maritime Organization D2 Standards; namely, Vibrio cholera (an environmental isolate from fish), Escherichia coli and Enterococcus faecalis. Volumes of 5 N NaOH were added to tryptic soy broth to obtain desired pH adjustments. Viable cells were determined after 0, 4, 12, 24, 48, and 72 h. Initial (0 h) cell numbers ranged from 3.40 × 104 cfu/mL for Bacillus sp. to 2.44 × 107 cfu/mL for E. faecalis. The effective endpoints of pH and treatment duration necessary to realize 100% bactericidal effect varied; however, all bacteria tested were killed within 72 h at pH 12.0 or lower. The lowest parameters examined, 4 h at pH 10.0, were bactericidal to V. cholera, E. ictaluri, three of four isolates of E. coli, and (three of four) Aeromonas salmonicida subsp. salmonicida. Bactericidal effect was attained at pH 10.0 within 12 h for the other A. salmonicida subsp. salmonicida, and within 24 h for P. fluorescens, and the remaining E. coli.

  11. Evaluation of bactericidal efficacy of silver ions on Escherichia coli for drinking water disinfection.

    Science.gov (United States)

    Pathak, Satya P; Gopal, K

    2012-07-01

    The purpose of this study is the development of a suitable process for the disinfection of drinking water by evaluating bactericidal efficacy of silver ions from silver electrodes. A prototype of a silver ioniser with silver electrodes and control unit has been fabricated. Silver ions from silver electrodes in water samples were estimated with an atomic absorption spectrophotometer. A fresh culture of Escherichia coli (1.75 × 10(3) c.f.u./ml) was exposed to 1, 2, 5, 10 and 20 ppb of silver ions in 100 ml of autoclaved tap water for 60 min. The effect of different pH and temperatures on bactericidal efficacy was observed at constant silver ion concentration (5 ppb) and contact time of 30 min. The maximum bactericidal activity (100%) was observed at 20 ppb of silver ion concentration indicating total disinfection after 20 min while minimum bactericidal activity (25%) was observed after 10 min at 01 ppb of silver ions. Likewise, 100% bactericidal activity was noticed with 2, 5 and 10 ppb of silver ions after 60, 50 and 40 min, respectively. Bactericidal activity at pH 5, 6, 7, 8 and 9 was observed at 79.9%, 79.8%, 80.5%, 100% and 100%, respectively, whereas it was 80.4%, 88.3%, 100%, 100% and 100% at 10°C, 20°C, 30°C, 40°C and 50°C, respectively. The findings of this study revealed that very low concentrations of silver ions at pH 8-9 and temperature >20°C have bactericidal efficacy for total disinfection of drinking water. Silver ionisation is suitable for water disinfection and an appropriate alternative to chlorination which forms carcinogenic disinfection by-products.

  12. Null bactericidal effect of ultraviolet radiation emitted by LEDs.

    Directory of Open Access Journals (Sweden)

    Francisco Alcántara Muñoz

    2016-11-01

    Full Text Available This research has aimed to assess the bactericidal effect of ultraviolet light emitted by LEDS on the growth on Petri dishes of microorganisms whose legal limits in foods have been established. An electrically fed apparatus has been designed with precise timing and a camera to prevent light spillage, in which two ultraviolet radiation emission devices were connected by LED technology at different wavelengths: through an array of LEDS emitting at around 350nm, and a single specific emission LED at 280nm. 1000 cfu of E. Coli and S. aureus sown on PCA were used as prototypes of gram negative and positive bacteria, respectively, onto which ultraviolet light was radiated at different time intervals, by means of both devices, with the whole experiment being carried out in triplicate . In none of the three series of treatments at the two wavelengths were reductions in microbial growth observed. The series of sowings on PCA were done on unseeded plates in order to be able to discard the likelihood of subsequent recontamination.

  13. Effect of bactericidal activity of three disinfectants on methicillin-resistant Staphylococcus aureus (MRSA

    Directory of Open Access Journals (Sweden)

    Cesar Augusto Marchionatti Avancini

    2017-05-01

    Full Text Available Background and Objectives: Methicillin-resistant Staphylococcus aureus (MRSA can cause hospital-acquired infections (HA-MRSA, community- acquired ones (CA-MRSA, and infections transmitted by pets and animals raised for food production (livestock-acquired or LA-MRSA. The conduct to control the transmission of these diseases requires a careful action against the causative agents on surfaces in the environment and the choice of disinfectants and antiseptics is crucial. The objective of the present study was to evaluate the effect of the bactericidal activity of sodium hypochlorite (SH, iodophor (I and a quaternary ammonium compound (QAC, cetyl-trimethyl-ammonium chloride, commonly used in hospital and animal production settings, on 21 MRSA isolates and a control bacterium, and test the hypothesis of cross resistance of antibiotics and disinfectants. Methods: The bactericidal activity of four successive dilutions of the disinfectants was evaluated through the suspension test, using an initial inoculum population density of 107 CFU/mL, after contact times of 5, 15 and 30 minutes. Results: Five minutes of contact of SH 25 ppm, I 12.5 ppm and QAC 125 ppm sufficed to inactivate the reference bacterium S. aureus ATCC 6538 and all MRSA. Conclusions: Once the factors that influence the efficiency of disinfectants are controlled, sodium hypochlorite, iodophor and the quaternary ammonium compound are suitable for controlling MRSA in the sources of infection. No resistance relationship was observed in the methicillin-resistant isolates with these substances.

  14. Bactericidal Effects of HVOF-Sprayed Nanostructured TiO2 on Pseudomonas aeruginosa

    Science.gov (United States)

    Jeffery, B.; Peppler, M.; Lima, R. S.; McDonald, A.

    2010-01-01

    Titanium dioxide (TiO2) has been shown to exhibit photocatalytic bactericidal activity. This preliminary study focused on examining the photocatalytic activity of high-velocity oxy-fuel (HVOF) sprayed nanostructured TiO2 coatings to kill Pseudomonas aeruginosa. The surfaces of the nanostructured TiO2 coatings were lightly polished before addition of the bacterial solution. Plates of P. aeruginosa were grown, and then suspended in a phosphate buffer saline (PBS) solution. The concentration of bacteria used was determined by a photo-spectrometer, which measured the amount of light absorbed by the bacteria-filled solution. This solution was diluted and pipetted onto the coating, which was exposed to white light in 30-min intervals, up to 120 min. It was found that on polished HVOF-sprayed coatings exposed to white light, 24% of the bacteria were killed after exposure for 120 min. On stainless steel controls, approximately 6% of the bacteria were not recovered. These preliminary results show that thermal-sprayed nanostructured TiO2 coatings exhibited photocatalytic bactericidal activity with P. aeruginosa.

  15. Bactericidal activites of selected macrofungi extracts against Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Nikolovska-Nedelkoska Daniela A.

    2017-01-01

    Full Text Available The increasing of the antibiotic resistance exhibited by pathogenic microorganisms has resulted in research directed toward evaluation of novel sources of antimicrobial compounds. Previous studies have indicated that macrofungi, as a specific response to the natural hostile environment, produce secondary metabolites with antimicrobial properties. In this study, antimicrobial activities of the extracts from six wild mushrooms: Amanita echinocephala, Russula medulata, Cerena unicolor, Hericium erinaceus, Ishnoderma benzoinum and Laetiporus sulphureus were evaluated against Grampositive bacterium Staphylococcus aureus. The antimicrobial potential of the methanolic mushroom extracts was investigated by the microdilution method. Antimicrobial activity was observed in all species included in the study. All the extracts that demonstrated inhibitory activities were further tested for bactericidal activity and minimum bactericidal concentration (MBC values were determined. The tested microorganism was most sensitive to the examined extracts from the polypore fungi C. unicolor and H. erinaceus. The highest bactericidal activity was obtained in the extracts from the species C. unicolor (MBC=1.563 mg/mL. The experimental results revealed that the methanolic extract of C. unicolor possessed significant bactericidal activity. The findings suggest the potential use of this wild mushroom as antimicrobial agent.

  16. Effect of food processing organic matter on photocatalytic bactericidal activity of titanium dioxide (TiO2).

    Science.gov (United States)

    Yemmireddy, Veerachandra K; Hung, Yen-Con

    2015-07-02

    The purpose of this study was to determine the effect of food processing organic matter on photocatalytic bactericidal activity of titanium dioxide (TiO2) nanoparticles (NPs). Produce and meat processing wash solutions were prepared using romaine lettuce and ground beef samples. Physico-chemical properties such as pH, turbidity, chemical oxygen demand (COD), total phenolics (for produce) and protein (for meat) content of the extracts were determined using standard procedures. The photocatalytic bactericidal activity of TiO2 (1 mg/mL) in suspension with or without organic matter against Escherichia coli O157:H7 (5-strain) was determined over a period of 3h. Increasing the concentration of organic matter (either produce or meat) from 0% to 100% resulted in 85% decrease in TiO2 microbicidal efficacy. 'Turbidity, total phenolics, and protein contents in wash solutions had significant effect on the log reduction. Increasing the total phenolics content in produce washes from 20 to 114 mg/L decreased the log reduction from 2.7 to 0.38 CFU/mL, whereas increasing the protein content in meat washes from 0.12 to 1.61 mg/L decreased the log reduction from and 5.74 to 0.87 CFU/mL. Also, a linear correlation was observed between COD and total phenolics as well as COD and protein contents. While classical disinfection kinetic models failed to predict, an empirical equation in the form of "Y=me(nX)" (where Y is log reduction, X is COD, and m and n are reaction rate constants) predicted the disinfection kinetics of TiO2 in the presence of organic matter (R(2)=94.4). This study successfully identified an empirical model with COD as a predictor variable to predict the bactericidal efficacy of TiO2 when used in food processing environment. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. The Integral Method, a new approach to quantify bactericidal activity.

    Science.gov (United States)

    Gottardi, Waldemar; Pfleiderer, Jörg; Nagl, Markus

    2015-08-01

    The bactericidal activity (BA) of antimicrobial agents is generally derived from the results of killing assays. A reliable quantitative characterization and particularly a comparison of these substances, however, are impossible with this information. We here propose a new method that takes into account the course of the complete killing curve for assaying BA and that allows a clear-cut quantitative comparison of antimicrobial agents with only one number. The new Integral Method, based on the reciprocal area below the killing curve, reliably calculates an average BA [log10 CFU/min] and, by implementation of the agent's concentration C, the average specific bactericidal activity SBA=BA/C [log10 CFU/min/mM]. Based on experimental killing data, the pertaining BA and SBA values of exemplary active halogen compounds were established, allowing quantitative assertions. N-chlorotaurine (NCT), chloramine T (CAT), monochloramine (NH2Cl), and iodine (I2) showed extremely diverging SBA values of 0.0020±0.0005, 1.11±0.15, 3.49±0.22, and 291±137log10 CFU/min/mM, respectively, against Staphylococcus aureus. This immediately demonstrates an approximately 550-fold stronger activity of CAT, 1730-fold of NH2Cl, and 150,000-fold of I2 compared to NCT. The inferred quantitative assertions and conclusions prove the new method suitable for characterizing bactericidal activity. Its application comprises the effect of defined agents on various bacteria, the consequence of temperature shifts, the influence of varying drug structure, dose-effect relationships, ranking of isosteric agents, comparison of competing commercial antimicrobial formulations, and the effect of additives. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Disclosure of the quackery: Testing of the bactericidal action of ...

    African Journals Online (AJOL)

    The obtained results indicate a fraud: bactericidal effect is rather a result of photocatalytic action of a hidden component used on purpose in the production of glass or subsequently applied by the use of nanotechnology (possibly antimony trioxide or titanium oxide) than of the so-called ''orgon and hydronic technology''.

  19. Effect of ZnO morphology on affecting bactericidal property of ultra high molecular weight polyethylene biocomposite

    International Nuclear Information System (INIS)

    Sharma, Rajeev Kumar; Agarwal, Meenakshi; Balani, Kantesh

    2016-01-01

    Bacterial infection of implants can be controlled by selective trapping of bacteria, followed with consequent killing by targeted antibacterial agents. Herein, the role of various ZnO morphologies, viz. micro-rods (R), nanoparticles (NP), and micro-disks (D) on antibacterial efficacy of ZnO via release of Zn"2"+ and H_2O_2 is assessed, both as isolated powders and via incorporating them in cytocompatible ultra high molecular weight polyethylene (UHMWPE). Though ZnO is antibacterial, interestingly, all ZnO morphologies elicited a supportive growth of gram-negative bacteria (Escherichia coli) in culture medium (until 28–35 μg/ml). But, all ZnO morphologies did elicit bactericidal effect on gram positive bacteria (Staphylococcus aureus or Staphylococcus epidermidis) both in culture medium (for 0–2.5 μg/ml) or when incorporated (5–20 wt.%) into UHMWPE. The bactericidal mechanisms were quantified for various ZnO morphologies via: (i) H_2O_2 production, (ii) Zn"2"+ release, and (iii) the presence of surface oxygen vacancies. On one hand, where only ZnO(NP) elicited release of H_2O_2 in the absence of light, maximum Zn"2"+ release was elicited by ZnO(D). Interestingly, when ZnO is incorporated as reinforcement (5–20 wt.%), its antibacterial action against E. coli was vividly observed due to selective proliferation of bacteria only on friendly UHMWPE matrix. Hence, luring bacteria on affable UHMWPE surface can be complemented with their targeted killing by ZnO present in composite. - Highlights: • The role of ZnO morphology in affecting bactericidal mechanisms • Quantification of Zn"2"+ release, H_2O_2 production and surface oxygen vacancy defects • Inherent resistance by gram negative bacteria at lower ZnO concentrations • Containment of bacteria on polymeric surface and consequent targeted killing by ZnO

  20. The bactericidal mechanism of action against Staphylococcus aureus for AgO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Wenning, E-mail: shenwenning@qq.com [School of Materials Science and Engineering, Xi' an University of Technology, No. 5 South Jinhua Road, Xi' an 710048 (China); Li, Pin [School of Materials Science and Engineering, Xi' an University of Technology, No. 5 South Jinhua Road, Xi' an 710048 (China); Feng, Hui [Shaanxi Institute of Zoology, Xi' an 710032 (China); Ge, Yanfeng; Liu, Zheng; Feng, Lajun [School of Materials Science and Engineering, Xi' an University of Technology, No. 5 South Jinhua Road, Xi' an 710048 (China)

    2017-06-01

    To identify the mechanistic effects of AgO nanoparticles on Gram-positive bacteria, S. aureus cells suspended in phosphate buffer solution (PBS) and deionized water were separately treated using AgO nanoparticles at different concentrations. The phase composition changes of the bactericide after killing S. aureus and the cellular responses of S. aureus to AgO were characterized by X-ray diffraction, atomic absorption spectrophotometer, scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy. The results show that AgO nanoparticles could kill S. aureus suspended in PBS and deionized water. The bactericidal effect of AgO bactericide against S. aureus in water was better than that in PBS, due to the formation of Ag{sub 3}PO{sub 4} from the reaction between AgO and PBS. AgO nanoparticles exerted their bactericidal activity by multiple processes. AgO nanoparticles adhered to the surface of S. aureus cells firstly, then induced physical alterations in cell morphology and released silver ions, leading to initial injuries of cell membrane. Once membrane damage occurred, they entered the cells, and damaged the intracellular materials, eventually causing severe morphological and structural injuries to the cells and leakage of cytoplasm. - Highlights: • S. aureus in water was more sensitive to AgO than in PBS, since AgO reacted with PBS and formed Ag{sub 3}PO{sub 4}. • After killing S. aureus in water, AgO did not changed. • AgO particles attached to cell surface then interacted with the cells, resulting in the increase of released silver contents. • Cell membrane damages by AgO nanoparticles were supported by the leakages of K{sup +}, proteins and DNA. • Serious cell morphological and structural changes were caused by AgO nanoparticles.

  1. The bactericidal mechanism of action against Staphylococcus aureus for AgO nanoparticles

    International Nuclear Information System (INIS)

    Shen, Wenning; Li, Pin; Feng, Hui; Ge, Yanfeng; Liu, Zheng; Feng, Lajun

    2017-01-01

    To identify the mechanistic effects of AgO nanoparticles on Gram-positive bacteria, S. aureus cells suspended in phosphate buffer solution (PBS) and deionized water were separately treated using AgO nanoparticles at different concentrations. The phase composition changes of the bactericide after killing S. aureus and the cellular responses of S. aureus to AgO were characterized by X-ray diffraction, atomic absorption spectrophotometer, scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy. The results show that AgO nanoparticles could kill S. aureus suspended in PBS and deionized water. The bactericidal effect of AgO bactericide against S. aureus in water was better than that in PBS, due to the formation of Ag 3 PO 4 from the reaction between AgO and PBS. AgO nanoparticles exerted their bactericidal activity by multiple processes. AgO nanoparticles adhered to the surface of S. aureus cells firstly, then induced physical alterations in cell morphology and released silver ions, leading to initial injuries of cell membrane. Once membrane damage occurred, they entered the cells, and damaged the intracellular materials, eventually causing severe morphological and structural injuries to the cells and leakage of cytoplasm. - Highlights: • S. aureus in water was more sensitive to AgO than in PBS, since AgO reacted with PBS and formed Ag 3 PO 4 . • After killing S. aureus in water, AgO did not changed. • AgO particles attached to cell surface then interacted with the cells, resulting in the increase of released silver contents. • Cell membrane damages by AgO nanoparticles were supported by the leakages of K + , proteins and DNA. • Serious cell morphological and structural changes were caused by AgO nanoparticles.

  2. Influence of nanoscale topology on bactericidal efficiency of black silicon surfaces

    Science.gov (United States)

    Linklater, Denver P.; Khuong Duy Nguyen, Huu; Bhadra, Chris M.; Juodkazis, Saulius; Ivanova, Elena P.

    2017-06-01

    The nanostructuring of materials to create bactericidal and antibiofouling surfaces presents an exciting alternative to common methods of preventing bacterial adhesion. The fabrication of synthetic bactericidal surfaces has been inspired by the anti-wetting and anti-biofouling properties of insect wings, and other topologies found in nature. Black silicon is one such synthetic surfaces which has established bactericidal properties. In this study we show that time-dependent plasma etching of silicon wafers using 15, 30, and 45 min etching intervals, is able to produce different surface geometries with linearly increasing heights of approximately 280, 430, and 610 nm, respectively. After incubation on these surfaces with Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa bacterial cells it was established that smaller, more densely packed pillars exhibited the greatest bactericidal activity with 85% and 89% inactivation of bacterial cells, respectively. The decrease in the pillar heights, pillar cap diameter and inter-pillar spacing corresponded to a subsequent decrease in the number of attached cells for both bacterial species.

  3. Comparison of the bactericidal activity of ozone and chlorine against Escherichia coli at 1/sup 0/

    Energy Technology Data Exchange (ETDEWEB)

    Fetner, R H; Ingols, R S

    1956-01-01

    The bactericidal effects of ozone solutions were tested against Escherichia coli suspensions at 1/sup 0/, and the lethal concentration was found to be that quantity of ozone necessary to produce a detectable residue in the suspension; under the conditions of these experiments this was 0.4-0.5 mg/l. A comparison of the bactericidal activity of chlorine under similar conditions emphasized the different modes of action of the two agents.

  4. Polyhexamethylene guanidine hydrochloride shows bactericidal advantages over chlorhexidine digluconate against ESKAPE bacteria.

    Science.gov (United States)

    Zhou, Zhongxin; Wei, Dafu; Lu, Yanhua

    2015-01-01

    More information regarding the bactericidal properties of polyhexamethylene guanidine hydrochloride (PHMG) against clinically important antibiotic-resistant ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens needs to be provided for its uses in infection control. The bactericidal properties of PHMG and chlorhexidine digluconate (CHG) were compared based on their minimum inhibitory concentrations (MICs), minimum bactericidal concentrations, and time-course-killing curves against clinically important antibiotic-susceptible and antibiotic-resistant ESKAPE pathogens. Results showed that PHMG exhibited significantly higher bactericidal activities against methicillin-resistant Staphylococcus aureus, carbapenem-resistant Klebsiella pneumoniae, and ceftazidime-resistant Enterobacter spp. than CHG. A slight bactericidal advantage over CHG was obtained against vancomycin-resistant Enterococcus faecium, ciprofloxacin- and levofloxacin-resistant Acinetobacter spp., and multidrug-resistant Pseudomonas aeruginosa. In previous reports, PHMG had higher antimicrobial activity against almost all tested Gram-negative bacteria and several Gram-positive bacteria than CHG using MIC test. These studies support the further development of covalently bound PHMG in sterile-surface materials and the incorporation of PHMG in novel disinfectant formulas. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

  5. [Antibacterial actin of vinegar against food-borne pathogenic bacteria including Escherichia coli O157:H7 (Part 2). Effect of sodium chloride and temperature on bactericidal activity].

    Science.gov (United States)

    Entani, E; Asai, M; Tsujihata, S; Tsukamoto, Y; Ohta, M

    1997-05-01

    Bactericidal effects of various kinds of AWASEZU (processed vinegar, 2.5% acidity) on food-borne pathogenic bacteria including Escherichia coli O157:H7 and other bacteria were examined. the order of bactericidal activities was NIHAIZU (3.5% NaCl was added) > SANBA-IZU (3.5% NaCl and 10% sucrose were added) > plain vinegar (spirit vinegar) > AMAZU (10% sucrose was added). This indicates that their activities were enhanced by the addition of sodium chloride and suppressed by the addition of sugar. On the other hand, when soy sauce was used instead of sodium chloride, the order of bactericidal activities was plain vinegar > AMAZU > NIHAIZU > SANBAIZU. This is mainly because their activities were suppressed by the increase in the pH value. The effect of sodium chloride (0.01-15%) and temperature (10-50 degrees C) on bactericidal activities against E. coli O157:H7 in spirit vinegar (0.5-2.5% acidity) was further examined. When vinegar was used in combination with sodium chloride, predominant synergism on the bactericidal activity was observed. Their activities were markedly enhanced by the addition of sodium chloride in proportion to the concentration. In addition to this, at higher temperatures spirit vinegar killed bacteria much more rapidly. It should be noted that the bactericidal activity of spirit vinegar was extremely enhanced by the combined use of the addition of sodium chloride and the rise of temperature. For example, in 2.5% acidity vinegar, the time required for 3 log decrease in viable cell numbers at 20 degrees C was shortened to 1/140-fold by the addition of 5% sodium chloride, shortened to 1/51-fold by the rise of the reaction temperature at 40 degrees C, and shortened to 1/830-fold; 0.89 minutes by both the addition of 5% sodium chloride and the rise of temperature at 40 degrees C. In order to propose the methods to prevent food poisoning by bacterial infection, bactericidal activities of vinegar solution containing sodium chloride on cooking tools and

  6. Bactericidal and Hemocompatible Coating via the Mixed-Charged Copolymer.

    Science.gov (United States)

    Fan, Xiao-Li; Hu, Mi; Qin, Zhi-Hui; Wang, Jing; Chen, Xia-Chao; Lei, Wen-Xi; Ye, Wan-Ying; Jin, Qiao; Ren, Ke-Feng; Ji, Jian

    2018-03-28

    Cationic antibacterial coating based on quaternary ammonium compounds, with an efficient and broad spectrum bactericidal property, has been widely used in various fields. However, the high density of positive charges tends to induce weak hemocompatibility, which hinders the application of the cationic antibacterial coating in blood-contacting devices and implants. It has been reported that a negatively charged surface can reduce blood coagulation, showing improved hemocompatibility. Here, we describe a strategy to combine the cationic and anionic groups by using mixed-charged copolymers. The copolymers of poly (quaternized vinyl pyridine- co- n-butyl methacrylate- co-methacrylate acid) [P(QVP- co- nBMA- co-MAA)] were synthesized through free radical copolymerization. The cationic group of QVP, the anionic group of MAA, and the hydrophobic group of nBMA were designed to provide bactericidal capability, hemocompatibility, and coating stability, respectively. Our findings show that the hydrophilicity of the copolymer coating increased, and its zeta potential decreased from positive charge to negative charge with the increase of the anionic/cationic ratio. Meanwhile, the bactericidal property of the copolymer coating was kept around a similar level compared with the pure quaternary ammonium copolymer coating. Furthermore, the coagulation time, platelet adhesion, and hemolysis tests revealed that the hemocompatibility of the copolymer coating improved with the addition of the anionic group. The mixed-charged copolymer combined both bactericidal property and hemocompatibility and has a promising potential in blood-contacting antibacterial devices and implants.

  7. Electrochemical analysis of the UV treated bactericidal Ti6Al4V surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pacha-Olivenza, Miguel A. [Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Department of Applied Physics, Faculty of Science, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Gallardo-Moreno, Amparo M., E-mail: amparogm@unex.es [Department of Applied Physics, Faculty of Science, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Vadillo-Rodríguez, Virginia; González-Martín, M. Luisa [Department of Applied Physics, Faculty of Science, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Pérez-Giraldo, Ciro [Department of Microbiology, Faculty of Medicine, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Galván, Juan C. [National Centre for Metallurgical Research (CENIM-CSIC), Av. Gregorio del Amo 8, 28040-Madrid (Spain)

    2013-04-01

    This research investigates in detail the bactericidal effect exhibited by the surface of the biomaterial Ti6Al4V after being subjected to UV-C light. It has been recently hypothesized that small surface currents, occurring as a consequence of the electron–hole pair recombination taking place after the excitation process, are behind the bactericidal properties displayed by this UV-treated material. To corroborate this hypothesis we have used different electrochemical techniques, such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization plots and Mott–Schottky plots. EIS and Mott–Schottky plots have shown that UV-C treatment causes an initial increase on the surface electrical conduction of this material. In addition, EIS and polarization plots demonstrated that higher corrosion currents occur at the UV treated than at the non-irradiated samples. Despite this increase in the corrosion currents, EIS has also shown that such currents are not likely to affect the good stability of this material oxide film since the irradiated samples completely recovered the control values after being stored in dark conditions for a period not longer than 24 h. These results agree with the already-published in vitro transitory behavior of the bactericidal effect, which was shown to be present at initial times after the biomaterial implantation, a crucial moment to avoid a large number of biomaterial associated infections. Highlights: ► Bactericidal response of UV-treated Ti6Al4V is explained through electrochemistry. ► There is an increase in the superficial electrical conduction after UV-treatment. ► Higher corrosion currents for UV-treated against non-UV-treated samples are shown. ► EIS shows the recuperation on irradiated samples in agreement with microbial tests.

  8. Electrochemical analysis of the UV treated bactericidal Ti6Al4V surfaces

    International Nuclear Information System (INIS)

    Pacha-Olivenza, Miguel A.; Gallardo-Moreno, Amparo M.; Vadillo-Rodríguez, Virginia; González-Martín, M. Luisa; Pérez-Giraldo, Ciro; Galván, Juan C.

    2013-01-01

    This research investigates in detail the bactericidal effect exhibited by the surface of the biomaterial Ti6Al4V after being subjected to UV-C light. It has been recently hypothesized that small surface currents, occurring as a consequence of the electron–hole pair recombination taking place after the excitation process, are behind the bactericidal properties displayed by this UV-treated material. To corroborate this hypothesis we have used different electrochemical techniques, such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization plots and Mott–Schottky plots. EIS and Mott–Schottky plots have shown that UV-C treatment causes an initial increase on the surface electrical conduction of this material. In addition, EIS and polarization plots demonstrated that higher corrosion currents occur at the UV treated than at the non-irradiated samples. Despite this increase in the corrosion currents, EIS has also shown that such currents are not likely to affect the good stability of this material oxide film since the irradiated samples completely recovered the control values after being stored in dark conditions for a period not longer than 24 h. These results agree with the already-published in vitro transitory behavior of the bactericidal effect, which was shown to be present at initial times after the biomaterial implantation, a crucial moment to avoid a large number of biomaterial associated infections. Highlights: ► Bactericidal response of UV-treated Ti6Al4V is explained through electrochemistry. ► There is an increase in the superficial electrical conduction after UV-treatment. ► Higher corrosion currents for UV-treated against non-UV-treated samples are shown. ► EIS shows the recuperation on irradiated samples in agreement with microbial tests

  9. Effect of ZnO morphology on affecting bactericidal property of ultra high molecular weight polyethylene biocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Rajeev Kumar [Biomaterials Processing and Characterization Laboratory, Indian Institute of Technology Kanpur, Kanpur -208016 (India); Agarwal, Meenakshi [Amity Institute of Nanotechnology, Amity University, Noida, Uttar Pradesh - 201303 (India); Balani, Kantesh, E-mail: kbalani@iitk.ac.in [Biomaterials Processing and Characterization Laboratory, Indian Institute of Technology Kanpur, Kanpur -208016 (India)

    2016-05-01

    Bacterial infection of implants can be controlled by selective trapping of bacteria, followed with consequent killing by targeted antibacterial agents. Herein, the role of various ZnO morphologies, viz. micro-rods (R), nanoparticles (NP), and micro-disks (D) on antibacterial efficacy of ZnO via release of Zn{sup 2+} and H{sub 2}O{sub 2} is assessed, both as isolated powders and via incorporating them in cytocompatible ultra high molecular weight polyethylene (UHMWPE). Though ZnO is antibacterial, interestingly, all ZnO morphologies elicited a supportive growth of gram-negative bacteria (Escherichia coli) in culture medium (until 28–35 μg/ml). But, all ZnO morphologies did elicit bactericidal effect on gram positive bacteria (Staphylococcus aureus or Staphylococcus epidermidis) both in culture medium (for 0–2.5 μg/ml) or when incorporated (5–20 wt.%) into UHMWPE. The bactericidal mechanisms were quantified for various ZnO morphologies via: (i) H{sub 2}O{sub 2} production, (ii) Zn{sup 2+} release, and (iii) the presence of surface oxygen vacancies. On one hand, where only ZnO(NP) elicited release of H{sub 2}O{sub 2} in the absence of light, maximum Zn{sup 2+} release was elicited by ZnO(D). Interestingly, when ZnO is incorporated as reinforcement (5–20 wt.%), its antibacterial action against E. coli was vividly observed due to selective proliferation of bacteria only on friendly UHMWPE matrix. Hence, luring bacteria on affable UHMWPE surface can be complemented with their targeted killing by ZnO present in composite. - Highlights: • The role of ZnO morphology in affecting bactericidal mechanisms • Quantification of Zn{sup 2+} release, H{sub 2}O{sub 2} production and surface oxygen vacancy defects • Inherent resistance by gram negative bacteria at lower ZnO concentrations • Containment of bacteria on polymeric surface and consequent targeted killing by ZnO.

  10. 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.

  11. BACTERICIDAL ACTIVITY OF HUMAN SERA AGAINST ...

    African Journals Online (AJOL)

    hi-tech

    East African Medical Journal Vol. 77 No. 12 December 2000. BACTERICIDAL ACTIVITY OF HUMAN SERA AGAINST SALMONELLA TYPHI AND SALMONELLA PARATYPHI A, B, C. E.O. Igumbor, BSc, MSc, PhD, Department of Medical Microbiology, School of Medicine, University of Zimbabwe P.O. Box Al78, Avondale, ...

  12. Bactericidal Effect of Lauric Acid-Loaded PCL-PEG-PCL Nano-Sized Micelles on Skin Commensal Propionibacterium acnes

    Directory of Open Access Journals (Sweden)

    Thi-Quynh-Mai Tran

    2016-08-01

    Full Text Available Acne is the over growth of the commensal bacteria Propionibacterium acnes (P. acnes on human skin. Lauric acid (LA has been investigated as an effective candidate to suppress the activity of P. acnes. Although LA is nearly insoluble in water, dimethyl sulfoxide (DMSO has been reported to effectively solubilize LA. However, the toxicity of DMSO can limit the use of LA on the skin. In this study, LA-loaded poly(ɛ-caprolactone-poly(ethylene glycol-poly(ɛ-caprolactone micelles (PCL-PEG-PCL were developed to improve the bactericidal effect of free LA on P. acnes. The block copolymers mPEG-PCL and PCL-PEG-PCL with different molecular weights were synthesized and characterized using 1H Nuclear Magnetic Resonance spectroscopy (1H NMR, Fourier-transform infrared spectroscopy (FT-IR, Gel Permeation Chromatography (GPC, and Differential Scanning Calorimetry (DSC. In the presence of LA, mPEG-PCL diblock copolymers did not self-assemble into nano-sized micelles. On the contrary, the average particle sizes of the PCL-PEG-PCL micelles ranged from 50–198 nm for blank micelles and 27–89 nm for LA-loaded micelles. The drug loading content increased as the molecular weight of PCL-PEG-PCL polymer increased. Additionally, the minimum inhibitory concentration (MIC and the minimum bactericidal concentration (MBC of free LA were 20 and 80 μg/mL, respectively. The MICs and MBCs of the micelles decreased to 10 and 40 μg/mL, respectively. This study demonstrated that the LA-loaded micelles are a potential treatment for acne.

  13. Bactericidal activity of self-assembled palmitic and stearic fatty acid crystals on highly ordered pyrolytic graphite.

    Science.gov (United States)

    Ivanova, Elena P; Nguyen, Song Ha; Guo, Yachong; Baulin, Vladimir A; Webb, Hayden K; Truong, Vi Khanh; Wandiyanto, Jason V; Garvey, Christopher J; Mahon, Peter J; Mainwaring, David E; Crawford, Russell J

    2017-09-01

    The wings of insects such as cicadas and dragonflies have been found to possess nanostructure arrays that are assembled from fatty acids. These arrays can physically interact with the bacterial cell membranes, leading to the death of the cell. Such mechanobactericidal surfaces are of significant interest, as they can kill bacteria without the need for antibacterial chemicals. Here, we report on the bactericidal effect of two of the main lipid components of the insect wing epicuticle, palmitic (C16) and stearic (C18) fatty acids. Films of these fatty acids were re-crystallised on the surface of highly ordered pyrolytic graphite. It appeared that the presence of two additional CH 2 groups in the alkyl chain resulted in the formation of different surface structures. Scanning electron microscopy and atomic force microscopy showed that the palmitic acid microcrystallites were more asymmetric than those of the stearic acid, where the palmitic acid microcrystallites were observed to be an angular abutment in the scanning electron micrographs. The principal differences between the two types of long-chain saturated fatty acid crystallites were the larger density of peaks in the upper contact plane of the palmitic acid crystallites, as well as their greater proportion of asymmetrical shapes, in comparison to that of the stearic acid film. These two parameters might contribute to higher bactericidal activity on surfaces derived from palmitic acid. Both the palmitic and stearic acid crystallite surfaces displayed activity against Gram-negative, rod-shaped Pseudomonas aeruginosa and Gram-positive, spherical Staphylococcus aureus cells. These microcrystallite interfaces might be a useful tool in the fabrication of effective bactericidal nanocoatings. Nanostructured cicada and dragonfly wing surfaces have been discovered to be able physically kill bacterial cells. Here, we report on the successful fabrication of bactericidal three-dimensional structures of two main lipid

  14. The behavior of active bactericidal and antifungal coating under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Gang; Zhang, Xiaodong; Zhao, Yan; Su, Haijia, E-mail: suhj@mail.buct.edu.cn; Tan, Tianwei

    2014-02-15

    In the present paper, the novel active bactericidal and antifungal coatings (ABAC) have been prepared through the immobilization of Fe-doped TiO{sub 2} (anatase) with chitosan. The characterization of ABAC using optical microscope imaging, SEM, AFM and FTIR shows that the Fe doped TiO{sub 2} is embedded into the chitosan coating with favorable dispersion through the hydrogen bonds interaction between chitosan molecules and TiO{sub 2}. The contact angle measurement demonstrated the hydrophilicity of ABAC (θ = 34.5 ± 4.1°). The bactericidal activity of ABAC has been evaluated by inactivating three different test strains: Escherichia coli, Candida albicans and Aspergillus niger which illustrates the apparently higher bactericidal ability than chitosan, Fe-TiO{sub 2} and chitosan/TiO{sub 2} (pure) under visible light irradiation and its bactericidal activity is lasting for at least 24 h. ABAC showed rapid and efficient antibacterial ability for the three tested strains and its antibacterial ratio in 2 h for E. coli, C. albicans and A. niger was 99.9%, 97.0% and 95.0%, respectively. The prepared chitosan/TiO{sub 2} composite emulsion shows favorable storage stability and can be stored up to 1 year without losing its bactericidal activity. ABAC is a low-cost and eco-friendly antibacterial coating products and promising for domestic, medical and industrial applications.

  15. In vitro bactericidal activity of Jinghua Weikang Capsule and its individual herb Chenopodium ambrosioides L. against antibiotic-resistant Helicobacter pylori.

    Science.gov (United States)

    Liu, Wei; Liu, Yu; Zhang, Xue-Zhi; Li, Ning; Cheng, Hong

    2013-01-01

    To investigate the bactericidal effects of Jinghua Weikang Capsule and its major component Chenopodium ambrosioides L. on antibiotic-resistant Helicobacter pylori. Four clinical antibiotic-resistant H. pylori strains were isolated and incubated in liquid medium containing Jinghua Weikang Capsule or Chenopodium ambrosioides L. By means of time-kill curve method, the average colony counts and bactericidal rate were calculated at time points of 0, 4, 8 and 24 h after the incubation and the time-kill curves were charted. Both Jinghua Weikang Capsule and Chenopodium ambrosioides L. at a concentration of 0.64 g/L showed obvious bactericidal effect against antibiotic-resistant H. pylori after 4 h of incubation. Jinghua Weikang Capsule and Chenopodium ambrosioides L. are considered to be active against antibiotic-resistant H. pylori in vitro.

  16. Bactericidal activity of ciprofloxacin upon Escherichia coli and Acinetobacter baumanni.

    Science.gov (United States)

    Zemelman, R; Vejar, C; Bello, H; Domínguez, M; González, G

    1992-01-01

    The mechanisms of bactericidal activity of ciprofloxacin (mechanisms A and B) upon cells of a strain of Escherichia coli and one strain of Acinetobacter baumannii were investigated under different conditions. The killing of E. coli cells by ciprofloxacin was significantly reduced by chloramphenicol, but this antibiotic showed almost no activity upon killing of A. baumannii cells by this quinolone. Similar results were obtained when rifampicin was added to ciprofloxacin. Bactericidal activity of ciprofloxacin upon nondividing cells of E. coli was lower and that upon non-dividing cells of A. baumannii was not affected when compared with activity of ciprofloxacin upon dividing cells of both microorganisms. These results demonstrate that the antibacterial activity of ciprofloxacin upon A. baumannii is independent of protein and ARN synthesis, a fact which suggests that this quinolone exerts only bactericidal mechanism B upon A. baumannii. This finding might explain, at least in part, the lower susceptibility of this microorganism to ciprofloxacin.

  17. Bactericidal activity of herbal volatile oil extracts against multidrug-resistant Acinetobacter baumannii.

    Science.gov (United States)

    Intorasoot, Amornrat; Chornchoem, Piyaorn; Sookkhee, Siriwoot; Intorasoot, Sorasak

    2017-01-01

    The aim of the study is to investigate the antibacterial activity of 10 volatile oils extracted from medicinal plants, including galangal ( Alpinia galanga Linn.), ginger ( Zingiber officinale ), plai ( Zingiber cassumunar Roxb.), lime ( Citrus aurantifolia ), kaffir lime ( Citrus hystrix DC.), sweet basil ( Ocimum basilicum Linn.), tree basil ( Ocimum gratissimum ), lemongrass ( Cymbopogon citratus DC.), clove ( Syzygium aromaticum ), and cinnamon ( Cinnamomum verum ) against four standard strains of Staphylococcus aureus , Escherichia coli , Pseudomonas aeruginosa , Acinetobacter baumannii , and 30 clinical isolates of multidrug-resistant A. baumannii (MDR- A. baumannii ). Agar diffusion, minimum inhibitory concentration, and minimum bactericidal concentration (MBC) were employed for the determination of bactericidal activity of water distilled medicinal plants. Tea tree oil ( Melaleuca alternifolia ) was used as positive control in this study. The results indicated the volatile oil extracted from cinnamon exhibited potent antibacterial activity against the most common human pathogens, S. aureus , E. coli , P. aeruginosa , and A. baumannii . Most of volatile oil extracts were less effective against non-fermentative bacteria, P. aeruginosa . In addition, volatile oil extracted from cinnamon, clove, and tree basil possessed potent bactericidal activity against MDR- A. baumannii with MBC 90 of 0.5, 1, and 2 mg/mL, respectively. The volatile oil extracts would be useful as alternative natural product for the treatment of the most common human pathogens and MDR- A. baumannii infections.

  18. Bactericidal action of photogenerated singlet oxygen from photosensitizers used in plaque disclosing agents.

    Directory of Open Access Journals (Sweden)

    Kirika Ishiyama

    Full Text Available BACKGROUND: Photodynamic therapy (PDT has been suggested as an efficient clinical approach for the treatment of dental plaque in the field of dental care. In PDT, once the photosensitizer is irradiated with light of a specific wavelength, it transfers the excitation energy to molecular oxygen, which gives rise to singlet oxygen. METHODOLOGY/PRINCIPAL FINDINGS: Since plaque disclosing agents usually contain photosensitizers such as rose bengal, erythrosine, and phloxine, they could be used for PTD upon photoactivation. The aim of the present study is to compare the ability of these three photosensitizers to produce singlet oxygen in relation to their bactericidal activity. The generation rates of singlet oxygen determined by applying an electron spin resonance technique were in the order phloxine > erythrosine ≒ rose bengal. On the other hand, rose bengal showed the highest bactericidal activity against Streptococcus mutans, a major causative pathogen of caries, followed by erythrosine and phloxine, both of which showed activity similar to each other. One of the reasons for the discrepancy between the singlet oxygen generating ability and bactericidal activity was the incorporation efficiency of the photosensitizers into the bacterial cells. The incorporation rate of rose bengal was the highest among the three photosensitizers examined in the present study, likely leading to the highest bactericidal activity. Meanwhile, the addition of L-histidine, a singlet oxygen quencher, cancelled the bactericidal activity of any of the three photoactivated photosensitizers, proving that singlet oxygen was responsible for the bactericidal action. CONCLUSIONS: It is strongly suggested that rose bengal is a suitable photosensitizer for the plaque disclosing agents as compared to the other two photosensitizers, phloxine and erythrosine, when used for PDT.

  19. Damage of Escherichia coli membrane by bactericidal agent polyhexamethylene guanidine hydrochloride: micrographic evidences.

    Science.gov (United States)

    Zhou, Z X; Wei, D F; Guan, Y; Zheng, A N; Zhong, J J

    2010-03-01

    The purpose of this study was to provide micrographic evidences for the damaged membrane structure and intracellular structure change of Escherichia coli strain 8099, induced by polyhexamethylene guanidine hydrochloride (PHMG). The bactericidal effect of PHMG on E. coli was investigated based on beta-galactosidase activity assay, fluorescein-5-isothiocyanate confocal laser scanning microscopy, field emission scanning electron microscopy and transmission electron microscopy. The results revealed that a low dose (13 microg ml(-1)) of PHMG slightly damaged the outer membrane structure of the treated bacteria and increased the permeability of the cytoplasmic membrane, while no significant damage was observed to the morphological structure of the cells. A high dose (23 microg ml(-1)) of PHMG collapsed the outer membrane structure, led to the formation of a local membrane pore across the membrane and badly damaged the internal structure of the cells. Subsequently, intracellular components were leaked followed by cell inactivation. Dose-dependent membrane disruption was the main bactericidal mechanism of PHMG. The formation of the local membrane pores was probable after exposure to a high dose (23 microg ml(-1)) of PHMG. Micrographic evidences were provided about the damaged membrane structure and intracellular structure change of E. coli. The presented information helps understand the bactericidal mechanism of PHMG by membrane damage.

  20. Serum bactericidal activity as indicator of innate immunity in pacu Piaractus mesopotamicus (Holmberg, 1887

    Directory of Open Access Journals (Sweden)

    J.D. Biller-Takahashi

    2013-12-01

    Full Text Available The immune system of teleost fish has mechanisms responsible for the defense against bacteria through protective proteins in several tissues. The protein action can be evaluated by serum bactericidal activity and this is an important tool to analyze the immune system. Pacu, Piaractus mesopotamicus, is one of the most important fish in national aquaculture. However there is a lack of studies on its immune responses. In order to standardize and assess the accuracy of the serum bactericidal activity assay, fish were briefly challenged with Aeromonas hydrophila and sampled one week after the challenge. The bacterial infection increased the concentration of protective proteins, resulting in a decrease of colony-forming unit values expressed as well as an enhanced serum bactericidal activity. The protocol showed a reliable assay, appropriate to determine the serum bactericidal activity of pacu in the present experimental conditions.

  1. Bactericidal activity of bio-synthesized silver nanoparticles against human pathogenic bacteria

    International Nuclear Information System (INIS)

    Abalkhil, Tarad Abdulaziz; Alharbi, Sulaiman Ali; Salmen, Saleh Hussein; Wainwright, Milton

    2017-01-01

    Green synthesis is an attractive and eco-friendly approach to generate potent antibacterial silver nanoparticles (Ag-NPs). Such particles have long been used to fight bacteria and represent a promising tool to overcome the emergence of antibiotic-resistant bacteria. In this study, green synthesis of Ag-NPs was attempted using plant extracts of Aloe vera, Portulaca oleracea and Cynodon dactylon. The identity and size of Ag-NPs was characterized by ultraviolet–visible spectrophotometer and scanning electron microscopy. Monodispersed Ag-NPs were produced with a range of different sizes based on the plant extract used. The bactericidal activity of Ag-NPs against a number of human pathogenic bacteria was determined using the disc diffusion method. The results showed that Gram positive bacteria were more susceptible than Gram negative ones to these antibacterial agents. The minimum inhibitory concentration was determined using the 96- well plate method. Finally, the mechanism by which Ag-NPs affect bacteria was investigated by SEM analysis. Bacteria treated with Ag-NPs were seen to undergo shrinkage and to lose their viability. This study provides evidence for a cheap and effective method for synthesizing potent bactericidal Ag-NPs and demonstrates their effectiveness against human pathogenic bacteria

  2. Effect of influenza infection on the phagocytic and bactericidal activities of pulmonary macrophages

    International Nuclear Information System (INIS)

    Nugent, K.M.; Pesanti, E.L.

    1979-01-01

    The effect of mouse-adapted influenza A/PR/8/34 virus on pulmonary macrophage function was evaluated by using an in vitro system which allowed direct virus interaction with macrophages and then separate analysis of the steps required for bacterial clearance by macrophages. Infection of macrophages with this virus resulted in the appearance of a hemagglutinating activity on the macrophage surface; expression of this activity was inhibited by amantadine, 2-deoxyglucose, and cycloheximide and by pretreatment of the virus inoculum with with ultraviolet light and specific antiserum. After influenza infection, net ingestion of viable Staphylococcus aureus by macrophage monolayers was unaltered and there was no change in the fraction of the monolayer which ingested cocci over a wide range of bacterial inputs. Influenza-infected microphages also inactivated intracellular S. aureus at a rate indistinguishable from controls. Therefore, these in vitro studies do not support the hypothesis that the defect in pulmonary antibacterial mechanisms associated with influenza infections results from a direct effect of virus infection on either the phagocytic or bactericidal activity of resistant pulmonary macarophages

  3. Bactericidal effect of blue LED light irradiated TiO2/Fe3O4 particles on fish pathogen in seawater

    International Nuclear Information System (INIS)

    Cheng, T.C.; Yao, K.S.; Yeh, N.; Chang, C.I.; Hsu, H.C.; Gonzalez, F.; Chang, C.Y.

    2011-01-01

    This study uses blue LED light (λ max = 475 nm) activated TiO 2 /Fe 3 O 4 particles to evaluate the particles' photocatalytic activity efficiency and bactericidal effects in seawater of variable salinities. Different TiO 2 to Fe 3 O 4 mole ratios have been synthesized using sol-gel method. The synthesized particles contain mainly anatase TiO 2 , Fe 3 O 4 and FeTiO 3 . The study has identified TiO 2 /Fe 3 O 4 's bactericidal effect to marine fish pathogen (Photobacterium damselae subsp. piscicida BCRC17065) in seawater. The SEM photo reveals the surface destruction in bacteria incubated with blue LED irradiated TiO 2 /Fe 3 O 4 . The result of this study indicates that 1) TiO 2 /Fe 3 O 4 acquires photocatalytic activities in both the freshwater and the seawater via blue LED irradiation, 2) higher photocatalytic activities appear in solutions of higher TiO 2 /Fe 3 O 4 mole ratio, and 3) photocatalytic activity decreases as salinity increases. These results suggest that the energy saving blue LED light is a feasible light source to activate TiO 2 /Fe 3 O 4 photocatalytic activities in both freshwater and seawater.

  4. Bactericidal Effect of Pterostilbene Alone and in Combination with Gentamicin against Human Pathogenic Bacteria.

    Science.gov (United States)

    Lee, Wee Xian; Basri, Dayang Fredalina; Ghazali, Ahmad Rohi

    2017-03-17

    The antibacterial activity of pterostilbene in combination with gentamicin against six strains of Gram-positive and Gram-negative bacteria were investigated. The minimum inhibitory concentration and minimum bactericidal concentration of pterostilbene were determined using microdilution technique whereas the synergistic antibacterial activities of pterostilbene in combination with gentamicin were assessed using checkerboard assay and time-kill kinetic study. Results of the present study showed that the combination effects of pterostilbene with gentamicin were synergistic (FIC index bacteria strains: Staphylococcus aureus ATCC 25923 , Escherichia coli O157 and Pseudomonas aeruginosa 15442 . However, the time-kill study showed that the interaction was indifference which did not significantly differ from the gentamicin treatment. Furthermore, time-kill study showed that the growth of the tested bacteria was completely attenuated with 2 to 8 h treatment with 0.5 × MIC of pterostilbene and gentamicin. The identified combinations could be of effective therapeutic value against bacterial infections. These findings have potential implications in delaying the development of bacterial resistance as the antibacterial effect was achieved with the lower concentrations of antibacterial agents.

  5. Studies on bactericidal efficacy of pumpkin (Cucurbita moschata Duchesne peel

    Directory of Open Access Journals (Sweden)

    El Zawane Kamarudin

    2014-02-01

    Full Text Available Objective: T o explore the in vitro antibacterial potential of the peel of Cucurbita moschata D uchesne ( tropical pumpkin ( C. moschata against human pathogenic bacteria. Methods: I n the present study, dichloromethane ( DCM , methanol ( MEOH and aqueous extracts of C. moschata peel were examined for in vitro antibacterial potency against eight bacterial strains i.e. Bacillus cereus, Burkholderia cepacia, Escherichia coli, Enterococcus faecalis, Staphyloccocus aureus, Pseudomonas aerugenosa, Vibrio alginolyticus, Vibrio parahaemolyticus using K irby- B auer disk diffusion susceptibility and broth micro-dilution methods. Results: DCM extract of pumpkin peel exhibited the maximum zone of inhibition against Staphyloccocus aureus ( 21 mm whereas aqueous extract of pumpkin peel revealed the least zone of inhibition against Escherichia coli ( 8 mm . MEOH extract gave maximum zone of inhibition against Pseudomonas aerugenosa ( 19 mm . B roth micro-dilution method showed minimum inhibitory concentration for the DCM extract against Burkholderia cepacia at 6 . 25 mg/m L . T he minimum bactericidal concentrations were also determined to know the nature of all extracts. DCM and MEOH extracts exhibited bactericidal nature to all bacterial strains except for the Vibrio alginolyticus. T he minimum bactericidal concentrations values exhibited bactericidal nature ranging from 3 . 12 mg/m L to 100 . 00 mg/m L . T he screening of antimicrobial properties of different extracts of C. moschata peel revealed that the DCM extract possessed good antimicrobial efficacy compared to MEOH and aqueous extracts. Conclusions: P eel of C. moschata possesses antibacterial compounds and could be potential source for a new class of antibiotics.

  6. Docosahexaenoic acid loaded lipid nanoparticles with bactericidal activity against Helicobacter pylori.

    Science.gov (United States)

    Seabra, Catarina Leal; Nunes, Cláudia; Gomez-Lazaro, Maria; Correia, Marta; Machado, José Carlos; Gonçalves, Inês C; Reis, Celso A; Reis, Salette; Martins, M Cristina L

    2017-03-15

    Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid present in fish oil, has been described as a promising molecule to the treatment of Helicobacter pylori gastric infection. However, due to its highly unsaturated structure, DHA can be easily oxidized loosing part of its bioactivity. This work aims the nanoencapsulation of DHA to improve its bactericidal efficacy against H. pylori. DHA was loaded into nanostructured lipid carriers (NLC) produced by hot homogenization and ultrasonication using a blend of lipids (Precirol ATO5 ® , Miglyol-812 ® ) and a surfactant (Tween 60 ® ). Homogeneous NLC with 302±14nm diameter, -28±3mV surface charge (dynamic and electrophoretic light scattering) and containing 66±7% DHA (UV/VIS spectroscopy) were successfully produced. Bacterial growth curves, performed over 24h in the presence of different DHA concentrations (free or loaded into NLC), demonstrated that nanoencapsulation enhanced DHA bactericidal effect, since DHA-loaded NLC were able to inhibit H. pylori growth in a much lower concentrations (25μM) than free DHA (>100μM). Bioimaging studies, using scanning and transmission electron microscopy and also imaging flow cytometry, demonstrated that DHA-loaded NLC interact with H. pylori membrane, increasing their periplasmic space and disrupting membrane and allowing the leakage of cytoplasmic content. Furthermore, the developed nanoparticles are not cytotoxic to human gastric adenocarcinoma cells at bactericidal concentrations. DHA-loaded NLC should, therefore, be envisaged as an alternative to the current treatments for H. pylori infection. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Bactericidal properties of silver films on intramedullary implants

    Science.gov (United States)

    Gallagher, C.; Walker, C.; Cortes, E.; Hettinger, Jeffrey; Krchnavek, R.; Caputo, G. A.; Ostrum, R.

    2011-03-01

    We report on investigations of silver films on titanium and stainless steel substrates as anti-bacterial coatings for intramedullary nails used in orthopedic trauma. Silver films are deposited using a magnetron sputtering technique from a single elemental target. The deposition parameter (energy, pressure, and temperature) dependence of the silver film microstructure and adhesion will be presented. Preliminary measurements of the effectiveness of the silver films as a bactericide on S. aureus bacteria demonstrate that the films are effective destroying the bacteria. The process of this investigation will be presented. Preliminary transmission electron microscopy measurements will also presented which image healthy and damaged bacteria helping to identify the fundamental mechanism leading to the effectiveness of silver as an anti-bacterial coating. We acknowledge the support of Rowan University, College of Liberal Arts and Sciences.

  8. Bactericidal activity of herbal volatile oil extracts against multidrug resistant Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    Amornrat Intorasoot

    2017-06-01

    Full Text Available Aim:\tTo investigate the antibacterial activity of ten volatile oils extracted from medicinal plants, including galangal (Alpinia galanga Linn., ginger (Zingiber officinale, plai (Zingiber cassumunar Roxb., lime (Citrus aurantifolia, kaffir lime (Citrus hystrix DC., sweet basil (Ocimum basilicum Linn., tree basil (Ocimum gratissimum, lemongrass (Cymbopogon citratus DC., clove (Syzygium aromaticum and cinnamon (Cinnamomum verum against four standard strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii and thirty clinical isolates of multidrug-resistant A. baumannii (MDR-A. baumannii. Methods:\tAgar diffusion, minimal inhibitory concentration (MIC and minimal bactericidal concentration (MBC were employed for determination of bactericidal activity of water distillated medicinal plants. Tea tree oil (Melaleuca alternifolia was used as positive control in this study. Results:\tThe results indicated the volatile oil extracted from cinnamon exhibited potent antibacterial activity against the most common human pathogens, S. aureus, E. coli, P. aeruginosa and A. baumannii. Most of volatile oil extracts were less effective against non-fermentative bacteria, P. aeruginosa. In addition, volatile oil extracted from cinnamon, clove and tree basil possessed potent bactericidal activity against MDR-A. baumannii with MBC90 of 0.5, 1 and 2 mg/mL, respectively. Conclusions: The volatile oil extracts would be useful as alternative natural product for treatment of the most common human pathogens and MDR-A. baumannii infections. [J Complement Med Res 2017; 6(2.000: 218-222

  9. Combined treatment of UVA irradiation and antibiotics induces greater bactericidal effects on Vibrio parahaemolyticus

    OpenAIRE

    Hou, Yanfei; Nakahashi, Mutsumi; Mawatari, Kazuaki; Shimohata, Takaaki; Uebanso, Takashi; Harada, Yumi; Tsunedomi, Akari; Emoto, Takahiro; Akutagawa, Masatake; Kinouchi, Yohsuke; Takahashi, Akira

    2016-01-01

    The presence of antibiotics in the environment and their subsequent impact on the development of multi-antibiotic resistant bacteria has raised concerns globally. Consequently, much research is focused on a method to produce a better disinfectant. We have established a disinfectant system using UVA-LED that inactivates pathogenic bacteria. We assessed the bactericidal efficiency of a combination of UVA-LED and antibiotics against Vibrio parahaemolyticus. Combined use of antibiotic drugs and U...

  10. Increased bactericidal activity of colistin on Pseudomonas aeruginosa biofilms in anaerobic conditions

    DEFF Research Database (Denmark)

    Kolpen, Mette; Appeldorff, Cecilie F.; Brandt, Sarah

    2016-01-01

    that production of OH˙may not contribute significantly to the bactericidal activity of colistin on P. aeruginosa biofilm. Thus, we investigated the effect of colistin treatment on biofilm of wild-type PAO1, a catalase-deficient mutant (katA) and a colistin-resistant CF isolate cultured in microtiter plates...

  11. Effect of organically modified clay on mechanical properties, cytotoxicity and bactericidal properties of poly(ɛ-caprolactone) nanocomposites

    Science.gov (United States)

    Kumar, Sachin; Mishra, Anupam; Chatterjee, Kaushik

    2014-12-01

    The objective of this study was to evaluate the use of organically-modified clay nanoparticles in poly(ɛ-caprolactone) (PCL) for developing biodegradable composites. PCL nanocomposites reinforced with two different types of organically-modified clay (Cloisite 30B, C30B and Cloisite 93A, C93A) were prepared by melt-mixing. Morphology of PCL/clay nanocomposites characterized by scanning electron microscopy indicated good dispersion of nanoclay in the PCL matrix. Reinforcement of nanoclay in PCL enhanced mechanical properties without affecting thermal and degradation properties of PCL. Cytocompatibility of PCL/clay nanocomposites was studied using both osteoblasts and endothelial cells in vitro. Both composites (PCL/C30B and PCL/C93A) were cytotoxic with high toxicity observed for C30B even at low content of 1 wt %. The cytotoxicity was found to arise due to leachables from PCL/clay composites. Electrical conductivity measurements of aqueous media confirmed leaching of cationic surfactant from the PCL/clay composites PCL matrix. Both composites were found to be bactericidal but C30B was more effective than C93A. Taken together, it was observed that organically-modified nanoclay as fillers in PCL improves mechanical properties and imparts bactericidal properties but with increased risk of toxicity. These PCL/clay composites may be useful as stronger packaging material with antibacterial properties but are not suited as biomedical implants or for food packaging applications.

  12. Bactericidal effect of bovine lactoferrin, LFcin, LFampin and LFchimera on antibiotic-resistant Staphylococcus aureus and Escherichia coli.

    Science.gov (United States)

    Flores-Villaseñor, Héctor; Canizalez-Román, Adrian; Reyes-Lopez, Magda; Nazmi, Kamram; de la Garza, Mireya; Zazueta-Beltrán, Jorge; León-Sicairos, Nidia; Bolscher, Jan G M

    2010-06-01

    Increased prevalence of antibiotic-resistant bacteria has become a major threat to the health sector worldwide due to their virulence, limited therapeutic options and distribution in both hospital and community settings. Discovery and development of new agents to combat antibiotic-resistant bacteria is thus needed. This study therefore aimed to evaluate the ability of bovine lactoferrin (LF), peptides from two antimicrobial domains lactoferricin B (LFcin17-30) and lactoferrampin (LFampin265-284) and a chimeric construct (LFchimera) containing both peptides, as potential bactericidal agents against clinical isolates of antibiotic-resistant Staphylococcus aureus and Escherichia coli. Results in kinetics of growth show that LF chimera and peptides inhibited the growth of both bacterial species. By confocal microscopy and flow cytometry it was observed that LF and FITC-labeled peptides are able to interact with these bacteria and cause membrane permeabilization, as monitored by propidium iodide staining, these effects were decreased by preincubation with lipopolysaccharide in E. coli. By electron microscopy, a clear cellular damage was observed in bacteria after treatments with LFchimera and peptides, suggesting that interaction and membrane disruption are probably involved as a mechanism of action. In conclusion, results show that LFchimera, LF and peptides have potential as bactericidal agents in the antibiotic-resistant strains of S. aureus and E. coli and also the work strongly suggest that LFcin17-30 and LFampin265-284 acts synergistically with antibiotics against multidrug resistant EPEC and MRSA in vitro.

  13. Bactericidal Effect of Pterostilbene Alone and in Combination with Gentamicin against Human Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Wee Xian Lee

    2017-03-01

    Full Text Available The antibacterial activity of pterostilbene in combination with gentamicin against six strains of Gram-positive and Gram-negative bacteria were investigated. The minimum inhibitory concentration and minimum bactericidal concentration of pterostilbene were determined using microdilution technique whereas the synergistic antibacterial activities of pterostilbene in combination with gentamicin were assessed using checkerboard assay and time-kill kinetic study. Results of the present study showed that the combination effects of pterostilbene with gentamicin were synergistic (FIC index < 0.5 against three susceptible bacteria strains: Staphylococcus aureus ATCC 25923, Escherichia coli O157 and Pseudomonas aeruginosa 15442. However, the time-kill study showed that the interaction was indifference which did not significantly differ from the gentamicin treatment. Furthermore, time-kill study showed that the growth of the tested bacteria was completely attenuated with 2 to 8 h treatment with 0.5 × MIC of pterostilbene and gentamicin. The identified combinations could be of effective therapeutic value against bacterial infections. These findings have potential implications in delaying the development of bacterial resistance as the antibacterial effect was achieved with the lower concentrations of antibacterial agents.

  14. Bactericidal activity under UV and visible light of cotton fabrics coated with anthraquinone-sensitized TiO2

    KAUST Repository

    Rahal, Raed

    2013-06-01

    This study describes a method derived from ISO/TC 206/SC specifications to assess the bactericidal activity against a bacterial strain, Pseudomonas fluorescens, of various photocatalytic fabrics, under UVA and filtered visible light. The experimental method allowed the accurate quantification of bacteria survival on photoactive surfaces and films under UVA and UV-free visible irradiation. Cotton fabrics coated with TiO2, anthraquinone or anthraquinone-sensitized TiO2 display a significant bactericidal efficiency. TiO2-coated fabrics are very efficient against P. fluorescens after 4 h UVA irradiation (bacteria survival below the detection limit). Under UVA-free visible light, anthraquinone-sensitized TiO2 coated fabrics induced a significant bactericidal activity after 2 h irradiation, while anthraquinone alone-coated fabrics were not as efficient and TiO2 coated fabrics were almost inefficient. These results show that although exhibiting a weak n-π* band in the 350-420 nm range, anthraquinone is a good candidate as an efficient visible light photosensitizer. A synergy effect between anthraquinone and TiO2 was demonstrated. A possible reaction mechanism, involving a synergy effect for singlet oxygen formation with anthraquinone-sensitized TiO2 is proposed to account for these results. © 2012 Elsevier B.V. All rights reserved.

  15. Enhanced bactericidal effect of enterocin AS-48 in combination with high-intensity pulsed-electric field treatment against Salmonella enterica in apple juice.

    Science.gov (United States)

    Martínez Viedma, Pilar; Sobrino López, Angel; Ben Omar, Nabil; Abriouel, Hikmate; Lucas López, Rosario; Valdivia, Eva; Martín Belloso, Olga; Gálvez, Antonio

    2008-12-10

    The effect of the broad spectrum cyclic antimicrobial peptide enterocin AS-48 combination with high-intensity pulsed-electric field (HIPEF) treatment (35 kV/cm, 150 Hz, 4 micros and bipolar mode) was tested on Salmonella enterica CECT 915 in apple juice. A response surface methodology was applied to study the bactericidal effects of the combined treatment. The process variables were AS-48 concentration, temperature, and HIPEF treatment time. While treatment with enterocin AS-48 alone up to 60 microg/ml had no effect on the viability of S. enterica in apple juice, an increased bactericidal activity was observed in combination with HIPEF treatments. Survival fraction was affected by treatment time, enterocin AS48 concentration and treatment temperature. The combination of 100 micros of HIPEF treatment, 30 microg/ml of AS-48, and temperature of 20 degrees C resulted in the lowest inactivation, with only a 1.2-log reduction. The maximum inactivation of 4.5-log cycles was achieved with HIPEF treatment for 1000 micros in combination with 60 microg/ml of AS-48 and a treatment temperature of 40 degrees C. Synergism between enterocin AS-48 and HIPEF treatment depended on the sequence order application, since it was observed only when HIPEF was applied in the presence of previously-added bacteriocin. The combined treatment could improve the safety of freshly-made apple juice against S. enterica transmission.

  16. Synergistic bactericidal effect by combined exposure to Ag nanoparticles and UVA

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiaoxu; Toyooka, Tatsushi; Ibuki, Yuko, E-mail: ibuki@u-shizuoka-ken.ac.jp

    2013-08-01

    Broad and strong antimicrobial properties of silver (Ag) have been used for biomedical applications, water treatment, etc. In this study, a synergistic antibacterial effect between Ag nanoparticles (AgNPs) and ultraviolet (UV) light was examined. AgNPs (< 0.1 μm) with subsequent exposure to UVA (320–400 nm) showed pronounced toxicity in Escherichia coli, but micro-sized Ag particles (> 1 μm) with UVA and AgNPs with UVB (280–325 nm) did not. As significant bactericidal activity was also exhibited by hydrogen peroxide-treated AgNPs, the surface oxidation of AgNPs caused by UVA irradiation was considered to contribute to the enhanced antibacterial effect. Although no difference in NP-incorporation rates was observed with or without the surface oxidation of AgNPs, a particle size of less than 0.1 μm was a factor for AgNPs uptake and an essential requirement for the antimicrobial function of Ag particles. Incorporated AgNPs oxidized by UVA irradiation released larger amounts of Ag ion inside cells than reduced AgNPs, which reacted with intercellular molecules having –SH groups such as glutathione. The synergistic use of AgNPs and UVA could become a powerful tool with broad antimicrobial applications. Highlights: • Combined treatment with AgNPs and UV achieved a remarkable antibacterial effect in E. coli. • For the antibacterial effect, it is necessary to satisfy the following requirements: • 1) Translocation of nano-sized Ag particles inside E. coli. • 2) Oxidation of AgNPs by UVA, and extensive and persistent release of Ag{sup +} inside E. coli. • Ag{sup +} released inside cells reacted with intercellular molecules having –SH groups such as GSH.

  17. Integrated antifouling and bactericidal polymer membranes through bioinspired polydopamine/poly(N-vinyl pyrrolidone) coating

    International Nuclear Information System (INIS)

    Wang, Xianghong; Yuan, Shuaishuai; Shi, Dean; Yang, Yingkui; Jiang, Tao; Yan, Shunjie; Shi, Hengchong; Luan, Shifang; Yin, Jinghua

    2016-01-01

    Graphical abstract: - Highlights: • Antifouling and bactericidal capabilities were facilely integrated into a surface via bioinspired coating. • The modification technique was very facile and universal to different types of substrate materials. • The integrated antifouling and bactericidal surfaces have great potential in wound dressing applications. - Abstract: Polypropylene (PP) non-woven has been widely used as wound dressing; however, the hydrophobic nature of PP can initiate bacterial attachment and subsequent biofilm formation. Herein, we propose a facile approach to functionalize PP non-woven with poly(ethylene glycol) (PEG) and poly(N-vinyl pyrrolidone)-iodine complex (PVP-I). PVP and PEG were successively tethered onto PP non-woven surface via versatile bioinspired dopamine (DA) chemistry, followed by complexing iodine with PVP moieties. It was demonstrated through the field emission scanning electron microscope (SEM) and spread plate method that the as-modified PP non-woven integrated both antifouling property of PEG for suppressing bacterial adhesion, and bactericidal property of PVP-I for killing the few adherent bacteria. Meanwhile, it could greatly resist platelet and red blood cell adhesion. The integrated antifouling and bactericidal PP non-woven surfaces might have great potential in various wound dressing applications.

  18. Integrated antifouling and bactericidal polymer membranes through bioinspired polydopamine/poly(N-vinyl pyrrolidone) coating

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianghong [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Materials Science and Engineering, Hubei University, Wuhan 430062 (China); Yuan, Shuaishuai [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Shi, Dean, E-mail: deanshi2012@yahoo.com [Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Materials Science and Engineering, Hubei University, Wuhan 430062 (China); Yang, Yingkui; Jiang, Tao [Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Materials Science and Engineering, Hubei University, Wuhan 430062 (China); Yan, Shunjie; Shi, Hengchong [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Luan, Shifang, E-mail: sfluan@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yin, Jinghua [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2016-07-01

    Graphical abstract: - Highlights: • Antifouling and bactericidal capabilities were facilely integrated into a surface via bioinspired coating. • The modification technique was very facile and universal to different types of substrate materials. • The integrated antifouling and bactericidal surfaces have great potential in wound dressing applications. - Abstract: Polypropylene (PP) non-woven has been widely used as wound dressing; however, the hydrophobic nature of PP can initiate bacterial attachment and subsequent biofilm formation. Herein, we propose a facile approach to functionalize PP non-woven with poly(ethylene glycol) (PEG) and poly(N-vinyl pyrrolidone)-iodine complex (PVP-I). PVP and PEG were successively tethered onto PP non-woven surface via versatile bioinspired dopamine (DA) chemistry, followed by complexing iodine with PVP moieties. It was demonstrated through the field emission scanning electron microscope (SEM) and spread plate method that the as-modified PP non-woven integrated both antifouling property of PEG for suppressing bacterial adhesion, and bactericidal property of PVP-I for killing the few adherent bacteria. Meanwhile, it could greatly resist platelet and red blood cell adhesion. The integrated antifouling and bactericidal PP non-woven surfaces might have great potential in various wound dressing applications.

  19. Inhibitory and bactericidal action of the biocorrosion agents «INCORGAS» and «AMDOR».

    Science.gov (United States)

    Tsygankova, L E; Vigdorovich, V I; Esina, M N; Nazina, T N; Dubinskaya, E V

    2014-06-01

    Inhibiting action of A, B and M-X compositions against hydrosulfide corrosion of carbon steel, hydrogen diffusion through the steel membrane has been studied along with their bactericidal effect with respect to sulfate-reducing bacteria of Desulfomicrobium type. Bactericidal properties of the compositions have been studied in the Postgate medium. Corrosion tests have been made in the NACE medium saturated by hydrogen sulfide and carbon dioxide separately and together by methods of gravimetrical measurements and linear polarization resistance (LRP). Potentiodynamic polarization and electrochemical diffusion method have been used. Steel protection is determined in the inhibited solutions by combined action of corrosion products film and inhibitor. Presence of sulfate-reducing bacteria in medium increases hydrogen diffusion flux through the steel membrane by 2-3 times and essentially stimulates effect of the inhibitors. The inhibiting compositions decrease quantity of sulfate-reducing bacteria (SRB) by 95-98%. The obtained results testify about predominately bacteriostatic action of the inhibiting compositions, which has influence on the enzymatic systems of SRB cells responsible directly for the sulfate reduction because of substantially decreasing the biogenic hydrogen sulfide concentration in the system. © 2013 Elsevier B.V. All rights reserved.

  20. Human Salivary Protein Histatin 5 Has Potent Bactericidal Activity against ESKAPE Pathogens.

    Science.gov (United States)

    Du, Han; Puri, Sumant; McCall, Andrew; Norris, Hannah L; Russo, Thomas; Edgerton, Mira

    2017-01-01

    ESKAPE ( Enterococcus faecium , Staphylococcus aureus , Klebsiella pneumoniae , Acinetobacter baumanni , Pseudomonas aeruginosa , and Enterobacter species) pathogens have characteristic multiple-drug resistance and cause an increasing number of nosocomial infections worldwide. Peptide-based therapeutics to treat ESKAPE infections might be an alternative to conventional antibiotics. Histatin 5 (Hst 5) is a salivary cationic histidine-rich peptide produced only in humans and higher primates. It has high antifungal activity against Candida albicans through an energy-dependent, non-lytic process; but its bactericidal effects are less known. We found Hst 5 has bactericidal activity against S. aureus (60-70% killing) and A. baumannii (85-90% killing) in 10 and 100 mM sodium phosphate buffer (NaPB), while killing of >99% of P. aeruginosa , 60-80% E. cloacae and 20-60% of E. faecium was found in 10 mM NaPB. Hst 5 killed 60% of biofilm cells of P. aeruginosa , but had reduced activity against biofilms of S. aureus and A. baumannii . Hst 5 killed 20% of K. pneumonia biofilm cells but not planktonic cells. Binding and uptake studies using FITC-labeled Hst 5 showed E. faecium and E. cloacae killing required Hst 5 internalization and was energy dependent, while bactericidal activity was rapid against P. aeruginosa and A. baumannii suggesting membrane disruption. Hst 5-mediated killing of S. aureus was both non-lytic and energy independent. Additionally, we found that spermidine conjugated Hst 5 (Hst5-Spd) had improved killing activity against E. faecium, E. cloacae , and A. baumannii . Hst 5 or its derivative has antibacterial activity against five out of six ESKAPE pathogens and may be an alternative treatment for these infections.

  1. The nature of inherent bactericidal activity: insights from the nanotopology of three species of dragonfly

    Science.gov (United States)

    Mainwaring, David E.; Nguyen, Song Ha; Webb, Hayden; Jakubov, Timur; Tobin, Mark; Lamb, Robert N.; Wu, Alex H.-F.; Marchant, Richard; Crawford, Russell J.; Ivanova, Elena P.

    2016-03-01

    While insect wings are widely recognised as multi-functional, recent work showed that this extends to extensive bactericidal activity brought about by cell deformation and lysis on the wing nanotopology. We now quantitatively show that subtle changes to this topography result in substantial changes in bactericidal activity that are able to span an order of magnitude. Notably, the chemical composition of the lipid nanopillars was seen by XPS and synchrotron FTIR microspectroscopy to be similar across these activity differences. Modelling the interaction between bacterial cells and the wing surface lipids of 3 species of dragonflies, that inhabit similar environments, but with distinctly different behavioural repertoires, provided the relationship between surface structure and antibacterial functionality. In doing so, these principal behavioural patterns correlated with the demands for antimicrobial efficiency dictated by differences in their foraging strategies. This work now reveals a new feature in the design elegance of natural multi-functional surfaces as well providing insights into the bactericidal mechanism underlying inherently antimicrobial materials, while suggesting that nanotopology is related to the evolutionary development of a species through the demands of its behavioural repertoire. The underlying relationship between the processes of wetting, adhesion and capillarity of the lipid nanopillars and bactericidal efficiency suggests new prospects for purely mechano-responsive antibacterial surfaces.While insect wings are widely recognised as multi-functional, recent work showed that this extends to extensive bactericidal activity brought about by cell deformation and lysis on the wing nanotopology. We now quantitatively show that subtle changes to this topography result in substantial changes in bactericidal activity that are able to span an order of magnitude. Notably, the chemical composition of the lipid nanopillars was seen by XPS and synchrotron

  2. Green Synthesis of Silver Nanoparticles and Their Bactericidal and Antimycotic Activities against Oral Microbes

    Directory of Open Access Journals (Sweden)

    Osvelia E. Rodríguez-Luis

    2016-01-01

    Full Text Available Nanotechnology is a new discipline with huge applications including medicine and pharmacology industries. Although several methods and reducing agents have been employed to synthesize silver nanoparticles, reactive chemicals promote toxicity and nondesired effects on the human and biological systems. The objective of this work was to synthesize silver nanoparticles from Glycyrrhiza glabra and Amphipterygium adstringens extracts and determine their bactericidal and antimycotic activities against Enterococcus faecalis and Candida albicans growth, respectively. 1 and 10 mM silver nitrate were mixed with an extract of Glycyrrhiza glabra and Amphipterygium adstringens. Green silver nanoparticles (AgNPs were characterized by TEM, Vis-NIR, FTIR, fluorescence, DLS, TGA, and X-ray diffraction (XRD analysis. Bactericidal and antimycotic activities of AgNPs were determined by Kirby and Bauer method and cell viability MTT assays. AgNPs showed a spherical shape and average size of 9 nm if prepared with Glycyrrhiza glabra extract and 3 nm if prepared with Amphipterygium adstringens extract. AgNPs inhibited the bacterial and fungal growth as was expected, without a significant cytotoxic effect on human epithelial cells. Altogether, these results strongly suggest that AgNPs could be an interesting option to control oral biofilms.

  3. A complex of equine lysozyme and oleic acid with bactericidal activity against Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Emily A Clementi

    Full Text Available HAMLET and ELOA are complexes consisting of oleic acid and two homologous, yet functionally different, proteins with cytotoxic activities against mammalian cells, with HAMLET showing higher tumor cells specificity, possibly due to the difference in propensity for oleic acid binding, as HAMLET binds 5-8 oleic acid molecules per protein molecule and ELOA binds 11-48 oleic acids. HAMLET has been shown to possess bactericidal activity against a number of bacterial species, particularly those with a respiratory tropism, with Streptococcus pneumoniae displaying the greatest degree of sensitivity. We show here that ELOA also displays bactericidal activity against pneumococci, which at lower concentrations shows mechanistic similarities to HAMLET's bactericidal activity. ELOA binds to S. pneumoniae and causes perturbations of the plasma membrane, including depolarization and subsequent rupture, and activates an influx of calcium into the cells. Selective inhibition of calcium channels and sodium/calcium exchange activity significantly diminished ELOA's bactericidal activity, similar to what we have observed with HAMLET. Finally, ELOA-induced death was also accompanied by DNA fragmentation into high molecular weight fragments - an apoptosis-like morphological phenotype that is seen during HAMLET-induced death. Thus, in contrast to different mechanisms of eukaryote cell death induced by ELOA and HAMLET, these complexes are characterized by rather similar activities towards bacteria. Although the majority of these events could be mimicked using oleic acid alone, the concentrations of oleic acid required were significantly higher than those present in the ELOA complex, and for some assays, the results were not identical between oleic acid alone and the ELOA complex. This indicates that the lipid, as a common denominator in both complexes, is an important component for the complexes' bactericidal activities, while the proteins are required both to solubilize

  4. Nanoparticle synthesis of zinc peroxide: structural and morphological characterization for bactericidal applications

    International Nuclear Information System (INIS)

    Colonia, Roberto; Martinez, Vanessa C.; Solis, Jose L.; Gomez, Monica M.

    2013-01-01

    Zinc peroxide (ZnO 2 ) nanoparticles were synthesized by sol-gel technique. The chemicals used for the synthesis were zinc acetate di-hydrate (Zn(CH 3 COO) 2. 2H 2 O) and hydrogen peroxide (H 2 O 2 ) at 30 % in an aqueous solution with sonication. The structure of the ZnO 2 nanoparticles was characterized by X-ray diffraction. While the morphology and the cluster size were determined using scanning and transmission electron microscopy. For a preliminary evaluation of the bactericidal properties of the ZnO 2 , the material was exposed to Staphylococcus aureus, Escherichia coli y Bacillus subtili, and the nanoparticles presented good bactericidal properties. (author)

  5. Bactericidal active ingredient in cryopreserved plasma-treated water with the reduced-pH method for plasma disinfection

    Science.gov (United States)

    Kitano, Katsuhisa; Ikawa, Satoshi; Nakashima, Yoichi; Tani, Atsushi; Yokoyama, Takashi; Ohshima, Tomoko

    2016-09-01

    For the plasma disinfection of human body, plasma sterilization in liquid is crucial. We found that the plasma-treated water (PTW) has strong bactericidal activity under low pH condition. Physicochemical properties of PTW is discussed based on chemical kinetics. Lower temperature brings longer half-life and the bactericidal activity of PTW can be kept by cryopreservation. High performance PTW, corresponding to the disinfection power of 22 log reduction (B. subtilis spore), can be obtained by special plasma system equipped with cooling device. This is equivalent to 65% H2O2, 14% sodium hypochlorite and 0.33% peracetic acid, which are deadly poison for human. But, it is deactivated soon at higher temperature (4 sec. at body temperature), and toxicity to human body seems low. For dental application, PTW was effective on infected models of human extracted tooth. Although PTW has many chemical components, respective chemical components in PTW were isolated by ion chromatography. In addition to peaks of H2O2, NO2- and NO3-, a specific peak was detected. and only this fraction had bactericidal activity. Purified active ingredient of PTW is the precursor of HOO, and further details will be discussed in the presentation. MEXT (15H03583, 23340176, 25108505). NCCE (23-A-15).

  6. Bactericidal effect of blue LED light irradiated TiO{sub 2}/Fe{sub 3}O{sub 4} particles on fish pathogen in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, T.C. [Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Taiwan (China); Yao, K.S. [Department of Horticulture, National Taitung Junior College, Taiwan (China); Yeh, N. [Mingdao University, Taiwan (China); Chang, C.I. [Aquaculture Division, Fisheries Research Institute, Council of Agriculture, Taiwan (China); Hsu, H.C. [Department of Life Science, Mingdao University, Taiwan (China); Gonzalez, F. [Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Taiwan (China); Chang, C.Y., E-mail: cyc1136@yahoo.com.tw [Center of General Education, National Taitung Junior College, Taiwan (China)

    2011-05-31

    This study uses blue LED light ({lambda}{sub max} = 475 nm) activated TiO{sub 2}/Fe{sub 3}O{sub 4} particles to evaluate the particles' photocatalytic activity efficiency and bactericidal effects in seawater of variable salinities. Different TiO{sub 2} to Fe{sub 3}O{sub 4} mole ratios have been synthesized using sol-gel method. The synthesized particles contain mainly anatase TiO{sub 2}, Fe{sub 3}O{sub 4} and FeTiO{sub 3}. The study has identified TiO{sub 2}/Fe{sub 3}O{sub 4}'s bactericidal effect to marine fish pathogen (Photobacterium damselae subsp. piscicida BCRC17065) in seawater. The SEM photo reveals the surface destruction in bacteria incubated with blue LED irradiated TiO{sub 2}/Fe{sub 3}O{sub 4}. The result of this study indicates that 1) TiO{sub 2}/Fe{sub 3}O{sub 4} acquires photocatalytic activities in both the freshwater and the seawater via blue LED irradiation, 2) higher photocatalytic activities appear in solutions of higher TiO{sub 2}/Fe{sub 3}O{sub 4} mole ratio, and 3) photocatalytic activity decreases as salinity increases. These results suggest that the energy saving blue LED light is a feasible light source to activate TiO{sub 2}/Fe{sub 3}O{sub 4} photocatalytic activities in both freshwater and seawater.

  7. Novel antiseptic compound OPB-2045G shows potent bactericidal activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus both in vitro and in vivo: a pilot study in animals.

    Science.gov (United States)

    Inoue, Yasuhide; Hagi, Akifumi; Nii, Takuya; Tsubotani, Yoshie; Nakata, Hikaru; Iwata, Koushi

    2015-01-01

    There is a need for new compounds to effectively treat methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). The novel monobiguanide compound 1-(3,4-dichlorobenzyl)-5-octylbiguanide gluconate (OPB-2045G) has potential bactericidal activity. We sought to elucidate the potency of OPB-2045G bactericidal activity against MRSA and VRE compared to those of chlorhexidine digluconate (CHG) and povidone iodine (PVP-I). In vitro bactericidal activity was analysed using minimum bactericidal concentration (MBC) as the index. The in vivo bactericidal efficacy of OPB-2045G was examined by determining MRSA and VRE contamination of the normal dorsal skin of mice following removal of hair. After a 3 min treatment period, the MBC of OPB-2045G was lower than that of CHG and PVP-I against standard strains and clinical isolates. Additionally, in our in vivo mouse model, the in vivo bactericidal activity of 1.5 % OPB-2045G (a clinically relevant dose) was higher than that of 0.5 % CHG and equivalent to that of 10 % PVP-I against MRSA. Similarly, the in vivo bactericidal activity of OPB-2045G was higher than that of 0.5 % CHG and 10 % PVP-I against VRE. OPB-2045G showed more potent bactericidal activity against MRSA and VRE both in vitro and in vivo compared to CHG and PVP-I, indicating that OPB-2045G may provide better protection against health care-associated infections caused by these pathogens. © 2015 The Authors.

  8. Lactobacillus proteins are associated with the bactericidal activity against E. coli of female genital tract secretions.

    Directory of Open Access Journals (Sweden)

    Sabah Kalyoussef

    Full Text Available Female genital tract secretions are bactericidal for Escherichia (E. coli ex vivo. However, the intersubject variability and molecules that contribute to this activity have not been defined.The bactericidal activity and concentration of immune mediators in cervicovaginal lavage (CVL collected from 99 healthy women were determined.CVL reduced the number of E. coli colonies by 68% [-26, 100] (median [range]. CVL were active against laboratory and clinical isolates of E. coli, but were inactive against Lactobacillus species. Bactericidal activity correlated with the concentration of protein recovered (p90% inhibitory activity (active and two with<30% activity were subjected to MS/MS proteomic analysis. 215 proteins were identified and six were found exclusively in active samples. Four of these corresponded to Lactobacillus crispatus or jensenii proteins. Moreover, culture supernatants from Lactobacillus jensenii were bactericidal for E. coli.Both host and commensal microbiota proteins contribute to mucosal defense. Identification of these proteins will facilitate the development of strategies to maintain a healthy vaginal microbiome and prevent colonization with pathogenic bacteria such as E. coli that increase the risk for urinary tract infections, preterm labor and perinatal infection.

  9. Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials

    Science.gov (United States)

    Sikora, Pawel; Augustyniak, Adrian; Cendrowski, Krzysztof; Horszczaruk, Elzbieta; Rucinska, Teresa; Nawrotek, Pawel; Mijowska, Ewa

    2016-01-01

    The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide) were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100%) to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed. PMID:28773823

  10. Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials

    Directory of Open Access Journals (Sweden)

    Pawel Sikora

    2016-08-01

    Full Text Available The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100% to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed.

  11. Comprehensive bactericidal activity of an ethanol-based hand gel in 15 seconds

    Directory of Open Access Journals (Sweden)

    Kampf Günter

    2008-01-01

    Full Text Available Abstract Background Some studies indicate that the commonly recommended 30 s application time for the post contamination treatment of hands may not be necessary as the same effect may be achieved with some formulations in a shorter application time such as 15 s. Method We evaluated the bactericidal activity of an ethanol-based hand gel (Sterillium® Comfort Gel within 15 s in a time-kill-test against 11 Gram-positive, 16 Gram-negative bacteria and 11 emerging bacterial pathogens. Each strain was evaluated in quadruplicate. Results The hand gel (85% ethanol, w/w was found to reduce all 11 Gram-positive and all 16 Gram-negative bacteria by more than 5 log10 steps within 15 s, not only against the ATCC test strains but also against corresponding clinical isolates. In addition, a log10 reduction > 5 was observed against all tested emerging bacterial pathogens. Conclusion The ethanol-based hand gel was found to have a broad spectrum of bactericidal activity in only 15 s which includes the most common species causing nosocomial infections and the relevant emerging pathogens. Future research will hopefully help to find out if a shorter application time for the post contamination treatment of hands provides more benefits or more risks.

  12. Two Major Medicinal Honeys Have Different Mechanisms of Bactericidal Activity

    NARCIS (Netherlands)

    Kwakman, Paulus H. S.; te Velde, Anje A.; de Boer, Leonie; Vandenbroucke-Grauls, Christina M. J. E.; Zaat, Sebastian A. J.

    2011-01-01

    Honey is increasingly valued for its antibacterial activity, but knowledge regarding the mechanism of action is still incomplete. We assessed the bactericidal activity and mechanism of action of Revamil (R) source (RS) honey and manuka honey, the sources of two major medical-grade honeys. RS honey

  13. In vitro and in vivo bactericidal activity of Tinospora sagittata (Oliv.) Gagnep. var. craveniana (S.Y.Hu) Lo and its main effective component, palmatine, against porcine Helicobacter pylori.

    Science.gov (United States)

    Rong, Qian; Xu, Min; Dong, Qi; Zhang, Yuli; Li, Yinglun; Ye, Gang; Zhao, Ling

    2016-08-30

    Tinospora sagittata (Oliv.) Gagnep. var. craveniana (S.Y.Hu) Lo (TSG) is a traditional Chinese herb that has been used for the treatment of upper respiratory tract infection and has anti-bacterial and anti-ulcer activity. Our study investigated the bactericidal effects of TSG and its major component, palmatine, against a Helicobacter pylori (H. pylori) strain isolated from pig and the standard strain H. pylori SS1 in vitro and in vivo. H. pylori was isolated from pig and named H. pylori SCYA201401. For in vitro experiments, the inhibitory activity of TSG and palmatine against H. pylori SCYA201401 and H. pylori SS1 were tested by use of the agar cup diffusion technique. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined from the absence of H. pylori colonies on agar plates. Time-kill curves were used to evaluate bactericidal activity; the average number of colonies was calculated at 0 to 48 h after liquid incubation, with concentrations of drugs at 0.5, 1, and 2 × MIC. For in vivo experiments, H. pylori SCYA201401-infected mice were randomly divided into TSG, palmatine, triple therapy (omeprazole, clarithromycin, and amoxicillin), blank control, and model groups. The eradication ratios were determined by use of rapid urease tests and bacterial culture. In vitro, the MIC and MBC of TSG against H. pylori SCYA201401 and SS1 were both 6250 μg/mL, whereas palmatine against H. pylori SCYA201401 was 6.25 μg/mL and against H. pylori SS1 was 3.12 μg/mL. The time-kill curves showed a dose-dependent, progressive decline in the numbers of viable bacteria up to 40 h. In vivo, the eradication ratios in the TSG and palmatine groups of mice were 80 and 50 % compared with 70 % in the triple-therapy group. TSG and its major component, palmatine, have bactericidal activity against H. pylori in vitro and in vivo. The possibility that TSG or palmatine can be effective in the treatment of human and animals H. pylori

  14. Adverse influence of ozone on pulmonary bactericidal activity of the murine lung

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, E; Tyler, W S; Hoeprich, P D; Eagle, C

    1971-01-01

    Mice infected with /sup 32/P-labeled Staphylococcus aureus and subsequently (30 to 45 min) exposed to 0.62 to 4.25 ppM O/sub 3/ for 4 hr showed less bactericidal activity (negative at higher concentrations) than controls not exposed to O/sub 3/. Counts of /sup 32/P showed 5 to 20% loss (ciliary clearance) from 0 to 5 hr with no O/sub 3/ effect. Histologically, capillaries and small vessels were dilated with occasional edema at higher concentrations. Inhibition of macrophage function was thought to account for these results.

  15. Genetic Allee effects and their interaction with ecological Allee effects.

    Science.gov (United States)

    Wittmann, Meike J; Stuis, Hanna; Metzler, Dirk

    2018-01-01

    It is now widely accepted that genetic processes such as inbreeding depression and loss of genetic variation can increase the extinction risk of small populations. However, it is generally unclear whether extinction risk from genetic causes gradually increases with decreasing population size or whether there is a sharp transition around a specific threshold population size. In the ecological literature, such threshold phenomena are called 'strong Allee effects' and they can arise for example from mate limitation in small populations. In this study, we aim to (i) develop a meaningful notion of a 'strong genetic Allee effect', (ii) explore whether and under what conditions such an effect can arise from inbreeding depression due to recessive deleterious mutations, and (iii) quantify the interaction of potential genetic Allee effects with the well-known mate-finding Allee effect. We define a strong genetic Allee effect as a genetic process that causes a population's survival probability to be a sigmoid function of its initial size. The inflection point of this function defines the critical population size. To characterize survival-probability curves, we develop and analyse simple stochastic models for the ecology and genetics of small populations. Our results indicate that inbreeding depression can indeed cause a strong genetic Allee effect, but only if individuals carry sufficiently many deleterious mutations (lethal equivalents). Populations suffering from a genetic Allee effect often first grow, then decline as inbreeding depression sets in and then potentially recover as deleterious mutations are purged. Critical population sizes of ecological and genetic Allee effects appear to be often additive, but even superadditive interactions are possible. Many published estimates for the number of lethal equivalents in birds and mammals fall in the parameter range where strong genetic Allee effects are expected. Unfortunately, extinction risk due to genetic Allee effects

  16. THE BACTERICIDAL ACTIVITY OF NORMAL GUINEA PIG SERUM AGAINST LISTERIA MONOCYTOGENES AND ITS INHIBITION BY A LISTERIAL CELL EXTRACT,

    Science.gov (United States)

    Normal guinea pig serum contains bactericidins active against Listeria monocytogenes. The listeriocidal activity of the serum did not increase after...factor. Lysozyme was not implicated in the bactericidal system. It was suggested that the bactericidal activity of guinea pig serum might be due either to

  17. Bactericidal Effect of Calcium Oxide (Scallop-Shell Powder) Against Pseudomonas aeruginosa Biofilm on Quail Egg Shell, Stainless Steel, Plastic, and Rubber.

    Science.gov (United States)

    Jung, Soo-Jin; Park, Shin Young; Kim, Seh Eun; Kang, Ike; Park, Jiyong; Lee, Jungwon; Kim, Chang-Min; Chung, Myung-Sub; Ha, Sang-Do

    2017-07-01

    The aim of this study was to evaluate the bactericidal effect of calcium oxide (CaO) against Pseudomonas aeruginosa biofilms on quail eggshells and major egg contacting surfaces (stainless steel, plastic, and rubber). The samples were subjected to CaO treatments (0%, 0.01%, 0.05%, 0.10%, 0.15%, 0.20%, 0.25%, and 0.30%) for 1 min. All the CaO treatments significantly reduced P. aeruginosa biofilms on all tested surfaces as compared to controls. In comparison of biofilm stability, the strongest and most resistant biofilm was formed on eggshell against the CaO treatment, followed by rubber, stainless steel, and plastic. In evaluation of bactericidal effect, the largest reduction (3.16 log CFU) was observed in plastic even at the lowest concentration of CaO (0.01%), whereas the least reduction was found in eggshells, regardless of CaO concentration. In addition, stainless steel showed a significant reduction in biofilm formation at all concentrations except 0.10% to 0.15% CaO. At 0.30% CaO, the reduction of P. aeruginosa in biofilms on stainless steel, plastic, rubber, and eggshell were 5.48, 6.37, 4.87, and 3.14 log CFU/cm 2 (CFU/egg), respectively. Biofilm reduction after CaO treatment was also observed by field emission scanning electron microscopy (FE-SEM). Based on the FE-SEM images, we observed that P. aeruginosa biofilms formed compact aggregations on eggshell surfaces with CaO treatments up to 0.30%. More specifically, a 0.20% CaO treatment resulted in the reductions of 3 to 6 log CFU in all materials. © 2017 Institute of Food Technologists®.

  18. Bactericidal efficacy of silver impregnated activated carbon for disinfection of water

    International Nuclear Information System (INIS)

    Sultana, L.; Khan, F.A.; Usmani, T.H.

    2009-01-01

    When highly contaminated water was passed through two types of silver coated activated carbon and their mixtures with sand, the former was found to be far better medium for disinfection of water, with bactericidal efficacy of about 2.5 times that of the latter. (author)

  19. Bactericidal Antibiotics Induce Toxic Metabolic Perturbations that Lead to Cellular Damage

    Directory of Open Access Journals (Sweden)

    Peter Belenky

    2015-11-01

    Full Text Available Understanding how antibiotics impact bacterial metabolism may provide insight into their mechanisms of action and could lead to enhanced therapeutic methodologies. Here, we profiled the metabolome of Escherichia coli after treatment with three different classes of bactericidal antibiotics (β-lactams, aminoglycosides, quinolones. These treatments induced a similar set of metabolic changes after 30 min that then diverged into more distinct profiles at later time points. The most striking changes corresponded to elevated concentrations of central carbon metabolites, active breakdown of the nucleotide pool, reduced lipid levels, and evidence of an elevated redox state. We examined potential end-target consequences of these metabolic perturbations and found that antibiotic-treated cells exhibited cytotoxic changes indicative of oxidative stress, including higher levels of protein carbonylation, malondialdehyde adducts, nucleotide oxidation, and double-strand DNA breaks. This work shows that bactericidal antibiotics induce a complex set of metabolic changes that are correlated with the buildup of toxic metabolic by-products.

  20. Hydrophobic pinning with copper nanowhiskers leads to bactericidal properties.

    Directory of Open Access Journals (Sweden)

    Ajay Vikram Singh

    Full Text Available The considerable morbidity associated with hospitalized patients and clinics in developed countries due to biofilm formation on biomedical implants and surgical instruments is a heavy economic burden. An alternative to chemically treated surfaces for bactericidal activity started emerging from micro/nanoscale topographical cues in the last decade. Here, we demonstrate a putative antibacterial surface using copper nanowhiskers deposited by molecular beam epitaxy. Furthermore, the control of biological response is based on hydrophobic pinning of water droplets in the Wenzel regime, causing mechanical injury and cell death. Scanning electron microscopy images revealed the details of the surface morphology and non-contact mode laser scanning of the surface revealed the microtopography-associated quantitative parameters. Introducing the bacterial culture over nanowhiskers produces mechanical injury to cells, leading to a reduction in cell density over time due to local pinning of culture medium to whisker surfaces. Extended culture to 72 hours to observe biofilm formation revealed biofilm inhibition with scattered microcolonies and significantly reduced biovolume on nanowhiskers. Therefore, surfaces patterned with copper nanowhiskers can serve as potential antibiofilm surfaces. The topography-based antibacterial surfaces introduce a novel prospect in developing mechanoresponsive nanobiomaterials to reduce the risk of medical device biofilm-associated infections, contrary to chemical leaching of copper as a traditional bactericidal agent.

  1. Ecological and evolutionary effects of stickleback on community structure.

    Directory of Open Access Journals (Sweden)

    Simone Des Roches

    Full Text Available Species' ecology and evolution can have strong effects on communities. Both may change concurrently when species colonize a new ecosystem. We know little, however, about the combined effects of ecological and evolutionary change on community structure. We simultaneously examined the effects of top-predator ecology and evolution on freshwater community parameters using recently evolved generalist and specialist ecotypes of three-spine stickleback (Gasterosteus aculeatus. We used a mesocosm experiment to directly examine the effects of ecological (fish presence and density and evolutionary (phenotypic diversity and specialization factors on community structure at lower trophic levels. We evaluated zooplankton biomass and composition, periphyton and phytoplankton chlorophyll-a concentration, and net primary production among treatments containing different densities and diversities of stickleback. Our results showed that both ecological and evolutionary differences in the top-predator affect different aspects of community structure and composition. Community structure, specifically the abundance of organisms at each trophic level, was affected by stickleback presence and density, whereas composition of zooplankton was influenced by stickleback diversity and specialization. Primary productivity, in terms of chlorophyll-a concentration and net primary production was affected by ecological but not evolutionary factors. Our results stress the importance of concurrently evaluating both changes in density and phenotypic diversity on the structure and composition of communities.

  2. Bactericidal effect of the photocatalystic reaction of titanium dioxide using visible wavelengths on Streptococcus mutans biofilm.

    Science.gov (United States)

    Kim, Chan-Hee; Lee, Eun-Song; Kang, Si-Mook; de Josselin de Jong, Elbert; Kim, Baek-Il

    2017-06-01

    The aim of this study was to determine the effect of titanium dioxide (TiO 2 ) photocatalysis induced by the application of clinically acceptable visible light at 405nm on the growth of Streptococcus mutans biofilms. S. mutans biofilms were grown on a hydroxyapatite (HA) disk and deposited in a rutile-type TiO 2 solution at a concentration of 0.1mg/mL. TiO 2 photocatalysis was measured for exposure to visible light (405nm) and ultraviolet (UV) light (254nm) produced by light-emitting diodes for 10, 20, 30, and 40min. After two treatments, the number of colonies formed in the final S. mutans biofilm on the HA disk were measured to confirm their viability, and the morphological changes of S. mutans were evaluated using scanning electronic microscopy. The bactericidal effects of 254- and 405-nm light resulted in > 5-log and 4-log reductions, respectively (p7-log reduction after 40min of treatment in both treatment groups relative to the control group. It was confirmed that the antibacterial effect could be shown by causing the photocatalytic reaction of TiO 2 in S. mutans biofilm even at the wavelength of visible light (405nm) as at the wavelength of ultraviolet light (254nm). Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Evaluation of bactericidal and anti-biofilm properties of a novel surface-active organosilane biocide against healthcare associated pathogens and Pseudomonas aeruginosa biolfilm.

    Directory of Open Access Journals (Sweden)

    Jason Murray

    Full Text Available Healthcare acquired infections (HAI pose a great threat in hospital settings and environmental contamination can be attributed to the spread of these. De-contamination and, significantly, prevention of re-contamination of the environment could help in preventing/reducing this threat. Goldshield (GS5 is a novel organosilane biocide marketed as a single application product with residual biocidal activity. We tested the hypothesis that GS5 could provide longer-term residual antimicrobial activity than existing disinfectants once applied to surfaces. Thus, the residual bactericidal properties of GS5, Actichlor and Distel against repeated challenge with Staphylococcus aureus ATCC43300 were tested, and showed that GS5 alone exhibited longer-term bactericidal activity for up to 6 days on 316I stainless steel surfaces. Having established efficacy against S. aureus, we tested GS5 against common healthcare acquired pathogens, and demonstrated that, on average, a 1 log10 bactericidal effect was exhibited by GS5 treated surfaces, although biocidal activity varied depending upon the surface type and the species of bacteria. The ability of GS5 to prevent Pseudomonas aeruginosa biofilm formation was measured in standard microtitre plate assays, where it had no significant effect on either biofilm formation or development. Taken together the data suggests that GS5 treatment of surfaces may be a useful means to reducing bacterial contamination in the context of infection control practices.

  4. Following the Mechanisms of Bacteriostatic versus Bactericidal Action Using Raman Spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Bernatová, Silvie; Samek, Ota; Pilát, Zdeněk; Šerý, Mojmír; Ježek, Jan; Jákl, Petr; Šiler, Martin; Krzyžánek, Vladislav; Zemánek, Pavel; Holá, V.; Dvořáčková, M.; Růžička, F.

    2013-01-01

    Roč. 18, č. 11 (2013), s. 13188-13199 ISSN 1420-3049 R&D Projects: GA MŠk ED0017/01/01; GA ČR GAP205/11/1687 Institutional support: RVO:68081731 Keywords : Raman spectroscopy * antibiotics * bacteria * bactericidal * bacteriostatic Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.095, year: 2013

  5. The Commonly Used Bactericide Bismerthiazol Promotes Rice Defenses against Herbivores

    Directory of Open Access Journals (Sweden)

    Pengyong Zhou

    2018-04-01

    Full Text Available Chemical elicitors that enhance plant resistance to pathogens have been extensively studied, however, chemical elicitors that induce plant defenses against insect pests have received little attention. Here, we found that the exogenous application of a commonly used bactericide, bismerthiazol, on rice induced the biosynthesis of constitutive and/or elicited jasmonic acid (JA, jasmonoyl-isoleucine conjugate (JA-Ile, ethylene and H2O2 but not salicylic acid. These activated signaling pathways altered the volatile profile of rice plants. White-backed planthopper (WBPH, Sogatella furcifera nymphs and gravid females showed a preference for feeding and/or oviposition on control plants: survival rates were better and more eggs were laid than on bismerthiazol-treated plants. Moreover, bismerthiazol treatment also increased both the parasitism rate of WBPH eggs laid on plants in the field by Anagrus nilaparvatae, and also the resistance of rice to the brown planthopper (BPH Nilaparvata lugens and the striped stem borer (SSB Chilo suppressalis. These findings suggest that the bactericide bismerthiazol can induce the direct and/or indirect resistance of rice to multiple insect pests, and so can be used as a broad-spectrum chemical elicitor.

  6. Multi-residue screening of prioritised human pharmaceuticals, illicit drugs and bactericides in sediments and sludge.

    Science.gov (United States)

    Langford, Katherine H; Reid, Malcolm; Thomas, Kevin V

    2011-08-01

    A robust multi-residue method was developed for the analysis of a selection of pharmaceutical compounds, illicit drugs and personal care product bactericides in sediments and sludges. Human pharmaceuticals were selected for analysis in Scottish sewage sludge and freshwater sediments based on prescription, physico-chemical and occurrence data. The method was suitable for the analysis of the selected illicit drugs amphetamine, benzoylecgonine, cocaine, and methamphetamine, the pharmaceuticals atenolol, bendroflumethiazide, carbamazepine, citalopram, diclofenac, fluoxetine, ibuprofen, and salbutamol, and the bactericides triclosan and triclocarban in sewage sludge and freshwater sediment. The method provided an overall recovery of between 56 and 128%, RSDs of between 2 and 19% and LODs of between 1 and 50 ng g(-1). Using the methodology the human pharmaceuticals atenolol, carbamazepine and citalopram and the bactericides triclosan and triclocarban were detected in Scottish sewage sludge. The illicit drugs cocaine, its metabolite benzoylecgonine, amphetamine and methamphetamine were not detected in any of the samples analysed. Triclosan and triclocarban were present at the highest concentrations with triclocarban detected in all but one sample and showing a pattern of co-occurrence in both sludge and sediment samples.

  7. Linking effects of anthropogenic debris to ecological impacts

    Science.gov (United States)

    Browne, Mark Anthony; Underwood, A. J.; Chapman, M. G.; Williams, Rob; Thompson, Richard C.; van Franeker, Jan A.

    2015-01-01

    Accelerated contamination of habitats with debris has caused increased effort to determine ecological impacts. Strikingly, most work on organisms focuses on sublethal responses to plastic debris. This is controversial because (i) researchers have ignored medical insights about the mechanisms that link effects of debris across lower levels of biological organization to disease and mortality, and (ii) debris is considered non-hazardous by policy-makers, possibly because individuals can be injured or removed from populations and assemblages without ecological impacts. We reviewed the mechanisms that link effects of debris across lower levels of biological organization to assemblages and populations. Using plastic, we show microplastics reduce the ‘health’, feeding, growth and survival of ecosystem engineers. Larger debris alters assemblages because fishing-gear and tyres kill animals and damage habitat-forming plants, and because floating bottles facilitate recruitment and survival of novel taxa. Where ecological linkages are not known, we show how to establish hypothetical links by synthesizing studies to assess the likelihood of impacts. We also consider how population models examine ecological linkages and guide management of ecological impacts. We show that by focusing on linkages to ecological impacts rather than the presence of debris and its sublethal impacts, we could reduce threats posed by debris. PMID:25904661

  8. Overview of climate information needs for ecological effects models

    Energy Technology Data Exchange (ETDEWEB)

    Peer, R.L.

    1990-01-01

    Atmospheric scientists engaged in climate change research require a basic understanding of how ecological effects models incorporate climate. The report provides an overview of existing ecological models that might be used to model climate change effects on vegetation. Some agricultural models and statistical methods are also discussed. The weather input data requirements, weather simulation methods, and other model characteristics relevant to climate change research are described for a selected number of models. The ecological models are classified as biome, ecosystem, or tree models; the ecosystem models are further subdivided into species dynamics or process models. In general, ecological modelers have had to rely on readily available meteorological data such as temperature and rainfall. Although models are becoming more sophisticated in their treatment of weather and require more kinds of data (such as wind, solar radiation, or potential evapotranspiration), modelers are still hampered by a lack of data for many applications. Future directions of ecological effects models and the climate variables that will be required by the models are discussed.

  9. Antibacterial activities of leave extracts as bactericides for soaking of skin or hide

    Science.gov (United States)

    Suparno, Ono; Panandita, Tania; Afifah, Amalia; Marimin; Purnawati, Rini

    2018-03-01

    Antibacteria, a subtance inhibiting the growth of bacteria, can be obtained from tropical-almond (Terminalia catappa), morinda (Morinda citrifolia), and white leadtree (Leucaena leucocephala) plants, since the plants have phytochemical content functioning as antibacterial agent. Commonly, part of plant that contains higher antibacterial substances is its leaf. The objectives of this study were to determine antibacterial activity of tropical-almond, morinda, and white leadtree leaves extracts, and to analyse the potency of the three extracts as natural bactericide for soaking of skin or hide. The responses measured in this study were phytochemical contents, total flavonoid, tannin content, the inhibition zone, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC). Phytochemical contents containing the three leaves extracts were alkaloid, flavonoid, tannin, saponin, phenolic, and glycoside. Total flavonoid and tannin contents of the three extracts were tropical-almond extract of 1.14 % and 1.51 %, respectively; morinda extract of 0.61 % and 0.36 %, respectively; and white leadtree extract of 0.60 % and 4.82 %, respectively. White leadtree leaf extract gave the highest inhibition zone against B. subtilis, S. aureus and E. coli, i.e. 1.50, 1.3, and 1.65 cm, respectively; and the lowest MIC and MBC against B. subtilis, S. aureus and E. coli, i.e. 1500, 3000, and 1500 μg/ml, respectively. Therefore, the white leadtree leave extract had more potential as bactericide for soaking of skin or hide compared to those of the tropical-almond and morinda leaves extracts.

  10. Two approaches to form antibacterial surface: Doping with bactericidal element and drug loading

    Energy Technology Data Exchange (ETDEWEB)

    Sukhorukova, I.V.; Sheveyko, A.N.; Kiryukhantsev-Korneev, Ph.V. [National University of Science and Technology “MISIS”, Leninsky pr. 4, Moscow 119049 (Russian Federation); Anisimova, N.Y.; Gloushankova, N.A.; Zhitnyak, I.Y. [N.N Blokhin Russian Cancer Research Center of RAMS, Kashirskoe shosse 24, Moscow 115478 (Russian Federation); Benesova, J. [Institute of Experimental Medicine of the ASCR, Vídenska 1083, Prague 14220 (Czech Republic); Institute of Biophysics, 2nd Faculty of Medicine, Charles University in Prague, V Uvalu 84, Prague 15006 (Czech Republic); Amler, E. [Institute of Experimental Medicine of the ASCR, Vídenska 1083, Prague 14220 (Czech Republic); Faculty of Biomedical Engineering, Czech Technical University in Prague (Czech Republic); Shtansky, D.V., E-mail: shtansky@shs.misis.ru [National University of Science and Technology “MISIS”, Leninsky pr. 4, Moscow 119049 (Russian Federation)

    2015-03-01

    Graphical abstract: - Highlights: • Bioactive materials with rate-controlled release of antibacterial agent. • Ag{sup +} ion release from TiCaPCON-Ag films depended on Ag content. • TiCaPCON-coated Ti network structure with blind pores loaded with co-amoxiclav. • Strong bactericidal effect of drug-loaded samples. • Antibacterial yet biocompatible and bioactive surfaces. - Abstract: Two approaches (surface doping with bactericidal element and loading of antibiotic into specially formed surface microcontainers) to the fabrication of antibacterial yet biocompatible and bioactive surfaces are described. A network structure with square-shaped blind pores of 2.6 ± 0.6 × 10{sup −3} mm{sup 3} for drug loading was obtained by selective laser sintering (SLS). The SLS-fabricated samples were loaded with 0.03, 0.3, 2.4, and 4 mg/cm{sup 2} of co-amoxiclav (amoxicillin and clavulanic acid). Ag-doped TiCaPCON films with 0.4, 1.2, and 4.0 at.% of Ag were obtained by co-sputtering of composite TiC{sub 0.5}-Ca{sub 3}(PO{sub 4}){sub 2} and metallic Ag targets. The surface structure of SLS-prepared samples and cross-sectional morphology of TiCaPCON-Ag films were studied by scanning electron microscopy. The through-thickness of Ag distribution in the TiCaPCON-Ag films was obtained by glow discharge optical emission spectroscopy. The kinetics of Ag ion release in normal saline solution was studied using inductively coupled plasma mass spectrometry. Bacterial activity of the samples was evaluated against S. epidermidis, S. aureus, and K. pneum. ozaenae using the agar diffusion test and photometric method by controlling the variation of optical density of the bacterial suspension over time. Cytocompatibility of the Ag-doped TiCaPCON films was observed in vitro using chondrocytic and MC3T3-E1 osteoblastic cells. The viability and proliferation of chondrocytic cells were determined using the MTS assay and PicoGreen assay tests, respectively. The alkaline phosphatase (ALP

  11. The Commonly Used Bactericide Bismerthiazol Promotes Rice Defenses against Herbivores

    OpenAIRE

    Pengyong Zhou; Xiaochang Mo; Wanwan Wang; Xia Chen; Yonggen Lou

    2018-01-01

    Chemical elicitors that enhance plant resistance to pathogens have been extensively studied, however, chemical elicitors that induce plant defenses against insect pests have received little attention. Here, we found that the exogenous application of a commonly used bactericide, bismerthiazol, on rice induced the biosynthesis of constitutive and/or elicited jasmonic acid (JA), jasmonoyl-isoleucine conjugate (JA-Ile), ethylene and H2O2 but not salicylic acid. These activated signaling pathways ...

  12. Linking effects of anthropogenic debris to ecological impacts.

    Science.gov (United States)

    Browne, Mark Anthony; Underwood, A J; Chapman, M G; Williams, Rob; Thompson, Richard C; van Franeker, Jan A

    2015-05-22

    Accelerated contamination of habitats with debris has caused increased effort to determine ecological impacts. Strikingly, most work on organisms focuses on sublethal responses to plastic debris. This is controversial because (i) researchers have ignored medical insights about the mechanisms that link effects of debris across lower levels of biological organization to disease and mortality, and (ii) debris is considered non-hazardous by policy-makers, possibly because individuals can be injured or removed from populations and assemblages without ecological impacts. We reviewed the mechanisms that link effects of debris across lower levels of biological organization to assemblages and populations. Using plastic, we show microplastics reduce the 'health', feeding, growth and survival of ecosystem engineers. Larger debris alters assemblages because fishing-gear and tyres kill animals and damage habitat-forming plants, and because floating bottles facilitate recruitment and survival of novel taxa. Where ecological linkages are not known, we show how to establish hypothetical links by synthesizing studies to assess the likelihood of impacts. We also consider how population models examine ecological linkages and guide management of ecological impacts. We show that by focusing on linkages to ecological impacts rather than the presence of debris and its sublethal impacts, we could reduce threats posed by debris. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  13. Influence of glycerol and an alternative humectant on the immediate and 3-hours bactericidal efficacies of two isopropanol-based antiseptics in laboratory experiments in vivo according to EN 12791

    Directory of Open Access Journals (Sweden)

    Miranda Suchomel

    2017-06-01

    Full Text Available Abstract Background Guidelines for hand hygiene recommend the use of alcohol-based hand rubs containing humectants in order to improve dermal tolerance. However, the bactericidal efficacy of pre-surgical hand rubs is negatively affected by the WHO-recommended humectant glycerol, especially the 3-h efficacy. The aim of this study was to investigate whether replacing glycerol as humectant increases the bactericidal efficacy of surgical hand rubs based on isopropanol (75%, wt/wt. Material and methods The efficacy of 3 and 5 min applications of a modified WHO II-formulation (containing lower glycerol concentrations and the TPH 5766 hand rub which contains a new humectant (containing ethylhexylglycerin, dexpanthenol and a fatty alcohol were compared to the European Norm 12,791 reference (n-propanol, 60%, vol/vol immediately following and 3 h after application. Results Immediately after application both isopropanol-based surgical rubs approximated the performance of the reference. The 3-h effect of the modified WHO II-formulation was found to be less efficacious than the EN 12791, showing a 30% decrease in log10 reduction values. The 3-h post application effect for the TPH 5766 hand rub was found to not be different from EN 12791. Conclusion Based on our data, the bactericidal efficacy of isopropanol-based surgical hand rubs can best be obtained if glycerol is not used in the formulation. Unlike glycerol, a humectant comprised of ethylhexylglycerin, dexpanthenol and a fatty alcohol was found not to decrease hand rub effectiveness. Further investigation of the bactericidal efficacy of other humectants is necessary and may prove useful.

  14. Persistence of bactericidal antibodies following early infant vaccination with a serogroup B meningococcal vaccine and immunogenicity of a preschool booster dose.

    Science.gov (United States)

    Snape, Matthew D; Saroey, Praveen; John, Tessa M; Robinson, Hannah; Kelly, Sarah; Gossger, Nicoletta; Yu, Ly-Mee; Wang, Huajun; Toneatto, Daniela; Dull, Peter M; Pollard, Andrew J

    2013-10-15

    The multicomponent serogroup B meningococcal (4CMenB) vaccine was recently licensed for use in Europe. There are currently no data on the persistence of bactericidal antibodies induced by use of this vaccine in infants. Our objective was to evaluate serogroup B-specific bactericidal antibodies in children aged 40-44 months previously vaccinated at 2, 4, 6 and 12 months of age. Participants given 4 doses of 4CMenB as infants received a fifth dose of the vaccine at 40-44 months of age. Age-matched participants who were MenB vaccine-naive received 4CMenB and formed the control group. We evaluated human complement serum bactericidal activity (hSBA) titres at baseline and 1 month after each dose of 4CMenB. Before a booster dose at enrolment, 41%-76% of 17 participants previously vaccinated with 4CMenB in infancy had hSBA titres of 4 or greater against 4 reference strains. Before vaccination in the control group (n = 40) these proportions were similar for strains 44/76-SL (63%) and M10713 (68%) but low for strains NZ98/254 (0%) and 5/99 (3%). A booster dose in the 4CMenB-primed participants generated greater increases in hSBA titres than in controls. As has been observed with other meningococcal vaccines, bactericidal antibodies waned after vaccination with 4CMenB administered according to an approved infant vaccination schedule of 2, 4, 6 and 12 months of age, but there was an anamnestic response to a booster dose at 40-44 months of age. If 4CMenB were introduced into routine vaccination schedules, assessment of the need for a booster dose would require data on the impact of these declining titres on vaccine effectiveness. ClinicalTrials.gov, no. NCT01027351.

  15. In vitro and in vivo bactericidal activity of Tinospora sagittata (Oliv.) Gagnep. var. craveniana (S.Y.Hu) Lo and its main effective component, palmatine, against porcine Helicobacter pylori

    OpenAIRE

    Rong, Qian; Xu, Min; Dong, Qi; Zhang, Yuli; Li, Yinglun; Ye, Gang; Zhao, Ling

    2016-01-01

    Background Tinospora sagittata (Oliv.) Gagnep. var. craveniana (S.Y.Hu) Lo (TSG) is a traditional Chinese herb that has been used for the treatment of upper respiratory tract infection and has anti-bacterial and anti-ulcer activity. Our study investigated the bactericidal effects of TSG and its major component, palmatine, against a Helicobacter pylori (H. pylori) strain isolated from pig and the standard strain H. pylori SS1 in vitro and in vivo. Methods H. pylori was isolated from pig and na...

  16. Influence of pulmonary surfactant on in vitro bactericidal activities of amoxicillin, ceftazidime, and tobramycin

    NARCIS (Netherlands)

    A. van 't Veen (Annemarie); J.W. Mouton (Johan); D.A.M.P.J. Gommers (Diederik); J.A.J.W. Kluytmans (Jan); P. Dekkers; B.F. Lachmann (Burkhard)

    1995-01-01

    textabstractThe influence of a natural pulmonary surfactant on antibiotic activity was investigated to assess the possible use of exogenous surfactant as a vehicle for antibiotic delivery to the lung. The influence of surfactant on the bactericidal activity of

  17. Fabrication of nonfouling, bactericidal, and bacteria corpse release multifunctional surface through surface-initiated RAFT polymerization.

    Science.gov (United States)

    Wang, Bailiang; Ye, Zi; Tang, Yihong; Han, Yuemei; Lin, Quankui; Liu, Huihua; Chen, Hao; Nan, Kaihui

    Infections after surgery or endophthalmitis are potentially blinding complications caused by bacterial adhesion and subsequent biofilm formation on the intraocular lens. Neither single-function anti-adhesion surface nor contacting killing surface can exhibit ideal antibacterial function. In this work, a novel (2-(dimethylamino)-ethyl methacrylate- co -2-methacryloyloxyethyl phosphorylcholine) (p (DMAEMA- co -MPC)) brush was synthesized by "grafting from" method through reversible-addition fragmentation chain transfer polymerization. 1-Bromoheptane was used to quaternize the p (DMAEMA- co -MPC) brush coating and to endow the surface with bactericidal function. The success of the surface functionalization was confirmed by atomic force microscopy, water contact angle, and spectroscopic ellipsometry. The quaternary ammonium salt units were employed as efficient disinfection that can eliminate bacteria through contact killing, whereas the 2-methacryloyloxyethyl phosphorylcholine units were introduced to suppress unwanted nonspecific adsorption. The functionalized poly(dimethyl siloxane) surfaces showed efficiency in reducing bovine serum albumin adsorption and in inhibiting bacteria adhesion and biofilm formation. The copolymer brushes also demonstrated excellent bactericidal function against gram-positive ( Staphylococcus aureus ) bacteria measured by bacteria live/dead staining and shake-flask culture methods. The surface biocompatibility was evaluated by morphology and activity measurement with human lens epithelial cells in vitro. The achievement of the p (DMAEMA + - co -MPC) copolymer brush coating with nonfouling, bactericidal, and bacteria corpse release properties can be used to modify intraocular lenses.

  18. Ecological effects of exposure to enhanced levels of ionizing radiation.

    Science.gov (United States)

    Geras'kin, Stanislav A

    2016-10-01

    Irradiation of plants and animals can result in disruption of ecological relationships between the components of ecosystems. Such effects may act as triggers of perturbation and lead to consequences that may differ essentially from expected ones based on effects observed at the organismal level. Considerable differences in ecology and niches occupied by different species lead to substantial differences in doses of ionizing radiation absorbed by species, even when they all are present in the same environment at the same time. This is especially evident for contamination with α-emitting radionuclides. Radioactive contamination can be considered an ecological factor that is able to modify the resistance in natural populations. However, there are radioecological situations when elevated radioresistance does not evolve or persist. The complexity and non-linearity of the structure and functioning of ecosystems can lead to unexpected consequences of stress effects, which would appear harmless if they were assessed within the narrower context of organism-based traditional radioecology. Therefore, the use of ecological knowledge is essential for understanding responses of populations and ecosystems to radiation exposure. Integration of basic ecological principles in the design and implementation of radioecological research is essential for predicting radiation effects under rapidly changing environmental conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Colloidal titania-silica-iron oxide nanocomposites and the effect from silica thickness on the photocatalytic and bactericidal activities

    Energy Technology Data Exchange (ETDEWEB)

    Chanhom, Padtaraporn [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Charoenlap, Nisanart [Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210 (Thailand); Tomapatanaget, Boosayarat [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Insin, Numpon, E-mail: Numpon.I@chula.ac.th [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

    2017-04-01

    New types of colloidal multifunctional nanocomposites that combine superparamagnetic character and high photocatalytic activity were synthesized and investigated. The superparamagnetic nanocomposites composed of anatase titania, silica, and iron oxide nanoparticles (TSI) were synthesized using thermal decomposition method followed by microemulsion method, without calcination at high temperature. Different techniques including X-ray diffraction (XRD) and transmission electron microscope (TEM) were used to characterize and confirm the structure of the nanocomposites. These nanocomposites showed high photocatalytic activity when used in the photodegradation of methylene blue under irradiation with a black light lamp. Moreover, the nanocomposites exhibited high antibacterial properties. From our study, the nanocomposites can be useful in various applications such as removal of pollutants with readily separation from the environment using an external magnetic field. These composites could effectively photo-degrade the dye at least three cycles without regeneration. The effects of silica shell thickness on the photocatalytic activity was investigated, and the thickness of 6 nm of the silica interlayer is enough for the inhibition of electron translocation between titania and iron oxide nanoparticles and maintaining the efficiency of photocatalytic activity of titania nanoparticles. - Highlights: • New colloidal nanocomposites of iron oxide-silica-titania were prepared. • The nanocomposites exhibited high photocatalytic activity with magnetic response. • The effects of silica thickness on photocatalytic activity were investigated. • Bactericidal activity of the nanocomposites was demonstrated.

  20. A rapid microtiter plate serum bactericidal assay method for determining serum complement-mediated killing of Mannheimia haemolytica.

    Science.gov (United States)

    Ayalew, Sahlu; Confer, Anthony W; Shrestha, Binu; Payton, Mark E

    2012-05-01

    In this study, we describe a rapid microtiter serum bactericidal assay (RMSBA) that can be used to measure the functionality of immune sera. It quantifies bactericidal activity of immune sera in the presence of complement against a homologous bacterium, M. haemolytica in this case. There is high correlation between data from RMSBA and standard complement-mediated bacterial killing assay (r=0.756; p<0.0001). The RMSBA activity of sera can be generated in less than 5 h instead of overnight incubation. RMSBA costs substantially less in terms of time, labor, and resources and is highly reproducible. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Ecological effectiveness as an essential quality requirement of innovational construction

    Directory of Open Access Journals (Sweden)

    Mkrtchyan Tamara

    2017-01-01

    Full Text Available Nowadays it seems to be very essential to develop national construction industry by implementation of innovative technologies. As an object of innovational construction «Smart house» or «green building» demonstrates the latest advances in ecological building materials, energy-saving structures and lean-technologies. According to the concept of TQM «green building» has tube compatible with environmental protection, environment sustainability and ecological effectiveness requirements. «Green certification» includes these terms into the National environment sustainability rating system. The main goal of this research work was to review and compare theoretical models and concepts of effectiveness and analyze their applicability to determine the term ecological effectiveness as the main Quality Score.

  2. Bactericidal activity of partially oxidized nanodiamonds.

    Science.gov (United States)

    Wehling, Julia; Dringen, Ralf; Zare, Richard N; Maas, Michael; Rezwan, Kurosch

    2014-06-24

    Nanodiamonds are a class of carbon-based nanoparticles that are rapidly gaining attention, particularly for biomedical applications, i.e., as drug carriers, for bioimaging, or as implant coatings. Nanodiamonds have generally been considered biocompatible with a broad variety of eukaryotic cells. We show that, depending on their surface composition, nanodiamonds kill Gram-positive and -negative bacteria rapidly and efficiently. We investigated six different types of nanodiamonds exhibiting diverse oxygen-containing surface groups that were created using standard pretreatment methods for forming nanodiamond dispersions. Our experiments suggest that the antibacterial activity of nanodiamond is linked to the presence of partially oxidized and negatively charged surfaces, specifically those containing acid anhydride groups. Furthermore, proteins were found to control the bactericidal properties of nanodiamonds by covering these surface groups, which explains the previously reported biocompatibility of nanodiamonds. Our findings describe the discovery of an exciting property of partially oxidized nanodiamonds as a potent antibacterial agent.

  3. The Ecological effect of conveyance pipeline from Gurara reservoir ...

    African Journals Online (AJOL)

    The study focuses on the public awareness of the effect of conveyance pipeline from Gurara reservoir to lower Usman Dam on Ecological degradation in Abuja, using data from questionnaire survey of about 150 households as well as field observation. The data from the survey reveals that over 30% ecological degradations ...

  4. Bactericidal strontium-releasing injectable bone cements based on bioactive glasses

    OpenAIRE

    Brauer, Delia S.; Karpukhina, Natalia; Kedia, Gopal; Bhat, Aditya; Law, Robert V.; Radecka, Izabela; Hill, Robert G.

    2013-01-01

    Strontium-releasing injectable bone cements may have the potential to prevent implant-related infections through the bactericidal action of strontium, while enhancing bone formation in patients suffering from osteoporosis. A melt-derived bioactive glass (BG) series (SiO2–CaO–CaF2–MgO) with 0–50% of calcium substituted with strontium on a molar base were produced. By mixing glass powder, poly(acrylic acid) and water, cements were obtained which can be delivered by injection and set in situ, gi...

  5. Subsets of memory CD4+ T cell and bactericidal antibody response to Neisseria meningitidis serogroup C after immunization of HIV-infected children and adolescents.

    Directory of Open Access Journals (Sweden)

    Lucimar G Milagres

    Full Text Available Meningococcal disease is endemic in Brazil, with periodic outbreaks and case fatality rates reach as high as 18 to 20% of cases. Conjugate vaccines against meningococci are immunogenic in healthy children. However, we have previously shown a poor bactericidal antibody response to a Men C conjugate vaccine in Brazilian HIV-infected children and adolescents after a single vaccine administration. The goal of the present work was to investigate associations between bactericidal antibody response induced by MenC vaccine and the frequency and activation profile (expression of CD38, HLA-DR and CCR5 molecules of total CD4+ memory T cell sub-populations in HIV-1-infected children and adolescents. Responders to vaccination against MenC had a predominance (about 44% of CD4+ TINTERMEDIATE subset followed by TTRANSITIONAL memory subset (23 to 26%. Importantly, CD4+ TINT frequency was positively associated with bactericidal antibody response induced by vaccination. The positive correlation persisted despite the observation that the frequency TINT CD38+HLA-DR+ was higher in responders. In contrast, CD4+ TCENTRAL MEMORY (TCM subset negatively correlated with bactericidal antibodies. In conclusion, these data indicate that less differentiated CD+ T cells, like TCM may be constantly differentiating into intermediate and later differentiated CD4+ T cell subsets. These include CD4 TINT subset which showed a positive association with bactericidal antibodies.

  6. Percutaneous external fixator pins with bactericidal micron-thin sol-gel films for the prevention of pin tract infection.

    Science.gov (United States)

    Qu, Haibo; Knabe, Christine; Radin, Shula; Garino, Jonathan; Ducheyne, Paul

    2015-09-01

    Risk of infection is considerable in open fractures, especially when fracture fixation devices are used to stabilize the fractured bones. Overall deep infection rates of 16.2% have been reported. The infection rate is even greater, up to 32.2%, with external fixation of femoral fractures. The use of percutaneous implants for certain clinical applications, such as percutaneous implants for external fracture fixation, still represents a challenge today. Currently, bone infections are very difficult to treat. Very potent antibiotics are needed, which creates the risk of irreversible damage to other organs, when the antibiotics are administered systemically. As such, controlled, local release is being pursued, but no such treatments are in clinical use. Herein, the use of bactericidal micron-thin sol-gel films on metallic fracture fixation pins is reported. The data demonstrates that triclosan (2,4,4'-trichloro-2'-hydroxydiphenylether), an antimicrobial agent, can be successfully incorporated into micron-thin sol-gel films deposited on percutaneous pins. The sol-gel films continuously release triclosan in vitro for durations exceeding 8 weeks (longest measured time point). The bactericidal effect of the micron-thin sol-gel films follows from both in vitro and in vivo studies. Inserting percutaneous pins in distal rabbit tibiae, there were no signs of infection around implants coated with a micron-thin sol-gel/triclosan film. Healing had progressed normally, bone tissue growth was normal and there was no epithelial downgrowth. This result was in contrast with the results in rabbits that received control, uncoated percutaneous pins, in which abundant signs of infection and epithelial downgrowth were observed. Thus, well-adherent, micron-thin sol-gel films laden with a bactericidal molecule successfully prevented pin tract infection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Inhibitory and bactericidal power of mangosteen rind extract towards Porphyromonas Gingivalis and Actinobacillus Actinomycetemcomitans (Laboratory test

    Directory of Open Access Journals (Sweden)

    Ina Hendiani

    2017-08-01

    Full Text Available Introduction: The bacteria that cause the occurrence of pathogens of periodontal disease are gram negative anaerobes. These bacteria include Pophyromonas Gingivalis and Actinobacillus Actinomycetemcomitans. Mangosteen skin extract is known to have anti-inflammatory, anti microbial, and anti oxidant properties. The extract of the mangosteen peel is altered in gel preparation in order to streamline its clinical application in periodontal disease. The purpose of this study was to examine the antibacterial power of the ginger mangosteen tree extract gel against Pophyromonas gingivalis and Actinobacillus Actinomycetemcomitans (Aggregatibacter Actinomycetemcomitans. Methods: This research was conducted by experimental laboratory. Mangosteen fruit extract gel with concentration of 100%, 50%, 25%, 12,5%, 6,25%, 3,125% and 0,78% were tested against Pophyromonas Gingivalis and Aggregatibacter Actinomycetemcomitans with agar diffusion method. Results and Discussion: The results of this study indicate that for Actinobacilus Aggregatibacter bacteria minimal inhibitory concentration at a concentration of 6.25% with a diameter of 13,5mm inhibition. Minimal bactericidal concentration at 12,5% concentration with 14,7mm inhibitory diameter. In the test of Pophyromonas Gingivalis bacteria, minimal inhibitory concentrations were obtained at a concentration of 1.56% and a minimum bactericidal concentration was obtained at a concentration of 3.125%. Conclusion: The conclusion that mangosteen peel skin gel extract can inhibit bacterial growth and is bactericidal against Pophyromonas Gingivalis and Actinobacillus Actinomycetemcomitans (Aggregatibacter Actinomycetecomitans.

  8. [Effect of ecological civilized homestead construction on schistosomiasis control].

    Science.gov (United States)

    Tang, Meng; Jia, Tie-Wu; Wu, Zi-Song; Mao, Ping; Chen, Lin; Li, Han-Gang; Zhong, Bo; Qiu, Dong-Chuan; Yao, Qin; Hu, You-Ping

    2012-02-01

    To evaluate the effect of Ecological Civilized Homestead Construction on schistosomiasis control. The data of ecological civilized homestead construction and schistosomiasis control were collected and analyzed in Meiwan Village, Shuangqiao Town, Danling County, Sichuan Province from 2004 to 2010. Ecological Civilized Homestead Construction was carried out from 2004 to 2010. Totally 454 bio-gas pools were built. All the farmers used well water. The popularized rates of the household bio-gas pool, sanitary toilet, sewage treatment pool reached 100%. The number of cattle was 4, which decreased by 91.30% compared with that in 2004, and all the cattle were fed in captivity. The schistosome infection rates of populations were 0.26% and 0.30% in 2005 and 2008, respectively, and nobody was infected in other years. The infection rate of cattle was 0 from 2004 to 2010. The awareness rate of knowledge about schistosomiasis control achieved 100% in the population over 6 years old. Most of the farmers could use certain protective measures while they were farming. The effect of ecological civilized homestead construction on schistosomiasis control is remarkable.

  9. Ecological effects of transuranics in the terrestrial environment

    International Nuclear Information System (INIS)

    Whicker, F.W.

    1980-01-01

    This chapter explores the ecological effects of transuranium radionuclides in terrestrial environments. No direct studies that relate the level of transuranic contamination to specific changes in structure or function of ecological systems have been carried out. The only alternative approach presently available is to infer such relationships from observations of biota in contaminated environments and models. Advantages and shortcomings of these observations as well as those of the direct experimental approach are discussed

  10. Efficacy of pH elevation as a bactericidal strategy for treating ballast water of freight carriers

    Directory of Open Access Journals (Sweden)

    Clifford E. Starliper

    2015-05-01

    Full Text Available Treatment of ship ballast water with sodium hydroxide (NaOH is one method currently being developed to minimize the risk to introduce aquatic invasive species. The bactericidal capability of sodium hydroxide was determined for 148 bacterial strains from ballast water collected in 2009 and 2010 from the M/V Indiana Harbor, a bulk-freight carrier plying the Laurentian Great Lakes, USA. Primary culture of bacteria was done using brain heart infusion agar and a developmental medium. Strains were characterized based on PCR amplification and sequencing of a portion of the 16S rRNA gene. Sequence similarities (99+ % were determined by comparison with the National Center for Biotechnology Information (NCBI GenBank catalog. Flavobacterium spp. were the most prevalent bacteria characterized in 2009, comprising 51.1% (24/47 of the total, and Pseudomonas spp. (62/101; 61.4% and Brevundimonas spp. (22/101; 21.8% were the predominate bacteria recovered in 2010; together, comprising 83.2% (84/101 of the total. Testing was done in tryptic soy broth (TSB medium adjusted with 5 N NaOH. Growth of each strain was evaluated at pH 10.0, pH 11.0 and pH 12.0, and 4 h up to 72 h. The median cell count at 0 h for 148 cultures was 5.20 × 106 cfu/mL with a range 1.02 × 105–1.60 × 108 cfu/mL. The TSB adjusted to pH 10.0 and incubation for less than 24 h was bactericidal to 52 (35.1% strains. Growth in pH 11.0 TSB for less than 4 h was bactericidal to 131 (88.5% strains and pH 11.0 within 12 h was bactericidal to 141 (95.3%. One strain, Bacillus horikoshii, survived the harshest treatment, pH 12.0 for 72 h.

  11. Efficacy of pH elevation as a bactericidal strategy for treating ballast water of freight carriers.

    Science.gov (United States)

    Starliper, Clifford E; Watten, Barnaby J; Iwanowicz, Deborah D; Green, Phyllis A; Bassett, Noel L; Adams, Cynthia R

    2015-05-01

    Treatment of ship ballast water with sodium hydroxide (NaOH) is one method currently being developed to minimize the risk to introduce aquatic invasive species. The bactericidal capability of sodium hydroxide was determined for 148 bacterial strains from ballast water collected in 2009 and 2010 from the M/V Indiana Harbor, a bulk-freight carrier plying the Laurentian Great Lakes, USA. Primary culture of bacteria was done using brain heart infusion agar and a developmental medium. Strains were characterized based on PCR amplification and sequencing of a portion of the 16S rRNA gene. Sequence similarities (99+ %) were determined by comparison with the National Center for Biotechnology Information (NCBI) GenBank catalog. Flavobacterium spp. were the most prevalent bacteria characterized in 2009, comprising 51.1% (24/47) of the total, and Pseudomonas spp. (62/101; 61.4%) and Brevundimonas spp. (22/101; 21.8%) were the predominate bacteria recovered in 2010; together, comprising 83.2% (84/101) of the total. Testing was done in tryptic soy broth (TSB) medium adjusted with 5 N NaOH. Growth of each strain was evaluated at pH 10.0, pH 11.0 and pH 12.0, and 4 h up to 72 h. The median cell count at 0 h for 148 cultures was 5.20 × 10(6) cfu/mL with a range 1.02 × 10(5)-1.60 × 10(8) cfu/mL. The TSB adjusted to pH 10.0 and incubation for less than 24 h was bactericidal to 52 (35.1%) strains. Growth in pH 11.0 TSB for less than 4 h was bactericidal to 131 (88.5%) strains and pH 11.0 within 12 h was bactericidal to 141 (95.3%). One strain, Bacillus horikoshii, survived the harshest treatment, pH 12.0 for 72 h.

  12. Controlled assembly of silver nano-fluid in Heliotropium crispum extract: A potent anti-biofilm and bactericidal formulation

    Science.gov (United States)

    Khan, Faria; Hashmi, Muhammad Uzair; Khalid, Nauman; Hayat, Muhammad Qasim; Ikram, Aamer; Janjua, Hussnain A.

    2016-11-01

    The study describes the optimized method for silver nanoparticle (AgNPs) synthesis using Heliotropium crispum (HC) plant extract. Optimization of physicochemical parameters resulted in stable and rapidly assembled AgNPs. FTIR results suggest presence of plant phytochemicals that helped in the reduction, stabilization and capping of AgNPs. The assembled Ag nano-composites displayed the peak surface plasmon resonance (SPR) around 428 nm. The presence of uniquely assembled Ag-biomolecule composites, cap and stabilize nanoparticles in aqueous plant suspension. Spherical, uniform-shaped AgNPs with low poly-dispersion and average particle size of 42 nm and was determined through dynamic light scattering (DLS) and scanning election microscopy (SEM) which present robust interaction with microbes. The study also evaluates the antimicrobial and anti-biofilm properties of biologically synthesized AgNPs on clinical isolates of MRSA, Pseudomonas aeruginosa and Acinetobacter baumannii. Minimum inhibitory concentration (0.5 mg mL-1) of nanoparticles that presented bactericidal effect was made through inhibition assays on bacterial strains. The concentration which presented potent bactericidal response was then evaluated through growth inhibition in liquid medium for anti-biofilm studies at 2.0 mg mL-1. HC-Ag nanoparticles mediated anti-biofilm effects on Pseudomonas aeruginosa was revealed through SEM. Complete breakdown of biofilm's extracellular polymeric substances resulted after incubation with AgNPs. Peptidoglycan cell wall destruction was also revealed on planktonic bacterial images after 24 h of incubation.

  13. Visual search in ecological and non-ecological displays: evidence for a non-monotonic effect of complexity on performance.

    Directory of Open Access Journals (Sweden)

    Philippe Chassy

    Full Text Available Considerable research has been carried out on visual search, with single or multiple targets. However, most studies have used artificial stimuli with low ecological validity. In addition, little is known about the effects of target complexity and expertise in visual search. Here, we investigate visual search in three conditions of complexity (detecting a king, detecting a check, and detecting a checkmate with chess players of two levels of expertise (novices and club players. Results show that the influence of target complexity depends on level of structure of the visual display. Different functional relationships were found between artificial (random chess positions and ecologically valid (game positions stimuli: With artificial, but not with ecologically valid stimuli, a "pop out" effect was present when a target was visually more complex than distractors but could be captured by a memory chunk. This suggests that caution should be exercised when generalising from experiments using artificial stimuli with low ecological validity to real-life stimuli.

  14. Susceptibility of Meningococcal Strains Responsible for Two Serogroup B Outbreaks on U.S. University Campuses to Serum Bactericidal Activity Elicited by the MenB-4C Vaccine.

    Science.gov (United States)

    Rossi, Raffaella; Beernink, Peter T; Giuntini, Serena; Granoff, Dan M

    2015-12-01

    In 2013 and 2014, two U.S. universities had meningococcal serogroup B outbreaks (a total of 14 cases) caused by strains from two different clonal complexes. To control the outbreaks, students were immunized with a serogroup B meningococcal vaccine (Novartis) that was not yet licensed in the United States. The vaccine (referred to as MenB-4C) contains four components capable of eliciting bactericidal activity. Both outbreak strains had high expression levels of two of the vaccine antigens (subfamily B factor H binding protein [FHbp] and neisserial heparin binding antigen [NHba]); the university B outbreak strain also had moderate expression of a third antigen, NadA. We investigated the bactericidal activity of sera from mice immunized with FHbp, NHba, or NadA and sera from MenB-4C-immunized infant macaques and an adult human. The postimmunization bactericidal activity of the macaque or human serum against isolates from university B with FHbp identification (ID) 1 that exactly matched the vaccine FHbp sequence variant was 8- to 21-fold higher than that against isolates from university A with FHbp ID 276 (96% identity to the vaccine antigen). Based on the bactericidal activity of mouse antisera to FHbp, NadA, or NHba and macaque or human postimmunization serum that had been depleted of anti-FHbp antibody, the bactericidal activity against both outbreak strains largely or entirely resulted from antibodies to FHbp. Thus, despite the high level of strain expression of FHbp from a subfamily that matched the vaccine antigen, there can be large differences in anti-FHbp bactericidal activity induced by MenB-4C vaccination. Further, strains with moderate to high NadA and/or NHba expression can be resistant to anti-NadA or anti-NHba bactericidal activity elicited by MenB-4C vaccination. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Effect of increased CRM₁₉₇ carrier protein dose on meningococcal C bactericidal antibody response.

    Science.gov (United States)

    Lee, Lucia H; Blake, Milan S

    2012-04-01

    New multivalent CRM(197)-based conjugate vaccines are available for childhood immunization. Clinical studies were reviewed to assess meningococcal group C (MenC) antibody responses following MenC-CRM(197) coadministration with CRM(197)-based pneumococcal or Haemophilus influenzae type b conjugate vaccines. Infants receiving a total CRM(197) carrier protein dose of ∼50 μg and concomitant diphtheria-tetanus-acellular pertussis (DTaP)-containing vaccine tended to have lower MenC geometric mean antibody titers and continued to have low titers after the toddler dose. Nevertheless, at least 95% of children in the reported studies achieved a MenC serum bactericidal antibody (SBA) titer of ≥ 1:8 after the last infant or toddler dose. SBA was measured using an assay with a baby rabbit or human complement source. Additional studies are needed to assess long-term antibody persistence and MenC CRM(197) conjugate vaccine immunogenicity using alternative dosing schedules.

  16. Bacterial Iron Uptake Pathways: Gates for the Import of Bactericide Compounds.

    Science.gov (United States)

    Schalk, Isabelle J; Mislin, Gaëtan L A

    2017-06-08

    Bacterial resistance to most antibiotics in clinical use has reached alarming proportions. A challenge for modern medicine will be to discover new antibiotics or strategies to combat multidrug resistant bacteria, especially Gram-negative bacteria for which the situation is particularly critical. Vectorization of bactericide compounds by siderophores (iron chelators produced by bacteria) is a promising strategy able to considerably increase the efficacy of drugs. Such a Trojan horse strategy can also extend activity of specific Gram-positive antibiotics to Gram-negative bacteria.

  17. Quantifying the dilution effect for models in ecological epidemiology.

    Science.gov (United States)

    Roberts, M G; Heesterbeek, J A P

    2018-03-01

    The dilution effect , where an increase in biodiversity results in a reduction in the prevalence of an infectious disease, has been the subject of speculation and controversy. Conversely, an amplification effect occurs when increased biodiversity is related to an increase in prevalence. We explore the conditions under which these effects arise, using multi species compartmental models that integrate ecological and epidemiological interactions. We introduce three potential metrics for quantifying dilution and amplification, one based on infection prevalence in a focal host species, one based on the size of the infected subpopulation of that species and one based on the basic reproduction number. We introduce our approach in the simplest epidemiological setting with two species, and show that the existence and strength of a dilution effect is influenced strongly by the choices made to describe the system and the metric used to gauge the effect. We show that our method can be generalized to any number of species and to more complicated ecological and epidemiological dynamics. Our method allows a rigorous analysis of ecological systems where dilution effects have been postulated, and contributes to future progress in understanding the phenomenon of dilution in the context of infectious disease dynamics and infection risk. © 2018 The Author(s).

  18. The Effect of Learning Cycle Model on Students’ Reducing Ecological Footprints

    Directory of Open Access Journals (Sweden)

    Özgül Keleş

    2011-12-01

    Full Text Available The objective of this study is to investigate effect of ecological footprint education, in which 5E learning cycle model is used, in reducing primary school students’ ecological footprints. The working group of the study is composed of 124 primary school students studying in 4th, 5th, 6th, 7th, 8th classes. In this study, 5E learning model is used in teaching a course in order to increase the participating students’ knowledge about ecological footprints and to calculate ecological footprints. Experimental method is used in this study. In data analysis, the paired samples t-test is used in for relevant samplings. The findings gathered indicate that ecological footprints of the participating students to the study decreased at the end of the study. It is determined that the mean of primary students’ ecological footprints differ from meaningfully according to level of the class and sex. Prospective solution offers are developed by handling the prospective effects of conclusions of the study on sustainable life and environmental education and conclusions’ importance in terms of learning and developing learning programmes with a critical point of view

  19. [Effects of biochar on microbial ecology in agriculture soil: a review].

    Science.gov (United States)

    Ding, Yan-Li; Liu, Jie; Wang, Ying-Ying

    2013-11-01

    Biochar, as a new type of soil amendment, has been obtained considerable attention in the research field of environmental sciences worldwide. The studies on the effects of biochar in improving soil physical and chemical properties started quite earlier, and already covered the field of soil microbial ecology. However, most of the studies considered the soil physical and chemical properties and the microbial ecology separately, with less consideration of their interactions. This paper summarized and analyzed the interrelationships between the changes of soil physical and chemical properties and of soil microbial community after the addition of biochar. Biochar can not only improve soil pH value, strengthen soil water-holding capacity, increase soil organic matter content, but also affect soil microbial community structure, and alter the abundance of soil bacteria and fungi. After the addition of biochar, the soil environment and soil microorganisms are interacted each other, and promote the improvement of soil microbial ecological system together. This review was to provide a novel perspective for the in-depth studies of the effects of biochar on soil microbial ecology, and to promote the researches on the beneficial effects of biochar to the environment from ecological aspect. The methods to improve the effectiveness of biochar application were discussed, and the potential applications of biochar in soil bioremediation were further analyzed.

  20. Human Lysozyme Synergistically Enhances Bactericidal Dynamics and Lowers the Resistant Mutant Prevention Concentration for Metronidazole to Helicobacter pylori by Increasing Cell Permeability

    Directory of Open Access Journals (Sweden)

    Xiaolin Zhang

    2016-10-01

    Full Text Available Metronidazole (MNZ is an effective agent that has been employed to eradicate Helicobacter pylori (H. pylori. The emergence of broad MNZ resistance in H. pylori has affected the efficacy of this therapeutic agent. The concentration of MNZ, especially the mutant prevention concentration (MPC, plays an important role in selecting or enriching resistant mutants and regulating therapeutic effects. A strategy to reduce the MPC that can not only effectively treat H. pylori but also prevent resistance mutations is needed. H. pylori is highly resistant to lysozyme. Lysozyme possesses a hydrolytic bacterial cell wall peptidoglycan and a cationic dependent mode. These effects can increase the permeability of bacterial cells and promote antibiotic absorption into bacterial cells. In this study, human lysozyme (hLYS was used to probe its effects on the integrity of the H. pylori outer and inner membranes using as fluorescent probe hydrophobic 1-N-phenyl-naphthylamine (NPN and the release of aspartate aminotransferase. Further studies using a propidium iodide staining method assessed whether hLYS could increase cell permeability and promote cell absorption. Finally, we determined the effects of hLYS on the bactericidal dynamics and MPC of MNZ in H. pylori. Our findings indicate that hLYS could dramatically increase cell permeability, reduce the MPC of MNZ for H. pylori, and enhance its bactericidal dynamic activity, demonstrating that hLYS could reduce the probability of MNZ inducing resistance mutations.

  1. Combined roles of human IgG subclass, alternative complement pathway activation, and epitope density in the bactericidal activity of antibodies to meningococcal factor h binding protein.

    Science.gov (United States)

    Giuntini, Serena; Reason, Donald C; Granoff, Dan M

    2012-01-01

    Meningococcal vaccines containing factor H binding protein (fHbp) are in clinical development. fHbp binds human fH, which enables the meningococcus to resist complement-mediated bacteriolysis. Previously, we found that chimeric human IgG1 mouse anti-fHbp monoclonal antibodies (MAbs) had human complement-mediated bactericidal activity only if the MAb inhibited fH binding. Since IgG subclasses differ in their ability to activate complement, we investigated the role of human IgG subclasses on antibody functional activity. We constructed chimeric MAbs in which three different murine fHbp-specific binding domains were each paired with human IgG1, IgG2, or IgG3. Against a wild-type group B isolate, all three IgG3 MAbs, irrespective of their ability to inhibit fH binding, had bactericidal activity that was >5-fold higher than the respective IgG1 MAbs, while the IgG2 MAbs had the least activity. Against a mutant with increased fHbp expression, the anti-fHbp MAbs elicited greater C4b deposition (classical pathway) and greater bactericidal activity than against the wild-type strain, and the IgG1 MAbs had similar or greater activity than the respective IgG3 MAbs. The bactericidal activity against both wild-type and mutant strains also was dependent, in part, on activation of the alternative complement pathway. Thus, at lower epitope density in the wild-type strain, the IgG3 anti-fHbp MAbs had the greatest bactericidal activity. At a higher epitope density in the mutant, the IgG1 MAbs had similar or greater bactericidal activity than the IgG3 MAbs, and the activity was less dependent on the inhibition of fH binding than at a lower epitope density.

  2. Bactericidal activity does not predict sterilizing activity: the case of rifapentine in the murine model of Mycobacterium ulcerans disease.

    Directory of Open Access Journals (Sweden)

    Deepak V Almeida

    Full Text Available Since 2004, treatment of Mycobacterium ulcerans disease, or Buruli ulcer, has shifted from surgery to daily treatment with streptomycin (STR + rifampin (RIF for 8 weeks. For shortening treatment duration, we tested the potential of daily rifapentine (RPT, a long-acting rifamycin derivative, as a substitute for RIF.BALB/c mice were infected with M. ulcerans in the right hind footpad and treated either daily (7/7 with STR+RIF or five days/week (5/7 with STR+RIF or STR+RPT for 4 weeks, beginning 28 days after infection when CFU counts were 4.88±0.51. The relative efficacy of the drug treatments was compared by footpad CFU counts during treatment and median time to footpad swelling after treatment cessation as measure of sterilizing activity. All drug treatments were bactericidal. After 1 week of treatment, the decline in CFU counts was significantly greater in treated mice but not different between the three treated groups. After 2 weeks of treatment, the decline in CFU was greater in mice treated with STR+RPT 5/7 than in mice treated with STR+RIF 7/7 and STR+RIF 5/7. After 3 and 4 weeks of treatment, CFU counts were nil in mice treated with STR+RPT and reduced by more than 3 and 4 logs in mice treated with STR+RIF 5/7 and STR+RIF 7/7, respectively. In sharp contrast to the bactericidal activity, the sterilizing activity was not different between all drug regimens although it was in proportion to the treatment duration.The better bactericidal activity of daily STR+RIF and especially of STR+RPT did not translate into better prevention of relapse, possibly because relapse-freecure after treatment of Buruli ulcer is more related to the reversal of mycolactone-induced local immunodeficiency by drug treatment rather than to the bactericidal potency of drugs.

  3. Smart Biointerface with Photoswitched Functions between Bactericidal Activity and Bacteria-Releasing Ability.

    Science.gov (United States)

    Wei, Ting; Zhan, Wenjun; Yu, Qian; Chen, Hong

    2017-08-09

    Smart biointerfaces with capability to regulate cell-surface interactions in response to external stimuli are of great interest for both fundamental research and practical applications. Smart surfaces with "ON/OFF" switchability for a single function such as cell attachment/detachment are well-known and useful, but the ability to switch between two different functions may be seen as the next level of "smart". In this work reported, a smart supramolecular surface capable of switching functions reversibly between bactericidal activity and bacteria-releasing ability in response to UV-visible light is developed. This platform is composed of surface-containing azobenzene (Azo) groups and a biocidal β-cyclodextrin derivative conjugated with seven quaternary ammonium salt groups (CD-QAS). The surface-immobilized Azo groups in trans form can specially incorporate CD-QAS to achieve a strongly bactericidal surface that kill more than 90% attached bacteria. On irradiation with UV light, the Azo groups switch to cis form, resulting in the dissociation of the Azo/CD-QAS inclusion complex and release of dead bacteria from the surface. After the kill-and-release cycle, the surface can be easily regenerated for reuse by irradiation with visible light and reincorporation of fresh CD-QAS. The use of supramolecular chemistry represents a promising approach to the realization of smart, multifunctional surfaces, and has the potential to be applied to diverse materials and devices in the biomedical field.

  4. BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT

    Science.gov (United States)

    2017-07-07

    TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT by Tobyn A. Branck Courtney M. Cowell Jennifer M. Rego and...October 2011 – September 2015 4. TITLE AND SUBTITLE BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT... REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT Introduction The Biological Sciences and Technology Team (BSTT), Warfighter

  5. Bactericidal activity of the Ti-13Nb-13Zr alloy against different species of bacteria related with implant infection.

    Science.gov (United States)

    Aguilera-Correa, John-Jairo; Conde, Ana; Arenas, Maria-Angeles; de-Damborenea, Juan-Jose; Marin, Miguel; Doadrio, Antonio L; Esteban, Jaime

    2017-08-11

    The Ti-6Al-4V alloy is one of the most commonly used in orthopedic surgery. Despite its advantages, there is an increasing need to use new titanium alloys with no toxic elements and improved biomechanical properties, such as Ti-13Nb-13Zr. Prosthetic joint infections (PJI) are mainly caused by Gram-positive bacteria; however, Gram-negative bacteria are a growing problem due to associated multidrug resistance. In this study, the bacterial adherence and viability on the Ti-13Nb-13Zr alloy have been compared to that of the Ti-6Al-4V alloy using 16 collection and clinical strains of bacterial species related to PJI: Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa. When compared with the Ti-6Al-4V alloy, bacterial adherence on the Ti-13Nb-13Zr alloy was significantly higher in most staphylococcal and P. aeruginosa strains and lower for E. coli strains. The proportion of live bacteria was significantly lower for both Gram-negative species on the Ti-13Nb-13Zr alloy than on the Ti-6Al-4V alloy pointing to some bactericidal effect of the Ti-13Nb-13Zr alloy. This bactericidal effect appears to be a consequence of the formation of hydroxyl radicals, since this effect is neutralized when dimethylsulfoxide was added to both the saline solution and water used to wash the stain. The antibacterial effect of the Ti-13Nb-13Zr alloy against Gram-negative bacteria is an interesting property useful for the prevention of PJI caused by these bacteria on this potential alternative to the Ti-6Al-4V alloy for orthopedic surgery.

  6. The Effect of Size and Ecology on Extinction Susceptibility

    Science.gov (United States)

    Huynh, C.; Yuan, A.; Heim, N.; Payne, J.

    2015-12-01

    Although life on Earth first emerged as prokaryotic organisms, it eventually evolved into billions of different species. However, extinctions on Earth, especially the five mass extinctions, have decimated species. So what leads to a species survival or demise during a mass extinction? Are certain species more susceptible to extinctions based on their size and ecology? For this project, we focused on the data of marine animals. To examine the impact of size and ecology on a species's likelihood of survival, we compared the sizes and ecologies of the survivors and victims of the five mass extinctions. The ecology, or life mode, of a genus consists of the combination of tiering, motility, and feeding mechanism. Tiering refers to the animal's typical location in the water column and sediments, motility refers to its ability to move, and feeding mechanism describes the way the organism eats; together, they describe the animal's behavior. We analyzed the effect of ecology on survival using logistic regression, which compares life mode to the success or failure of a genus during each mass extinction interval. For organism size, we found the extinct organisms' mean size (both volume and length) and compared it with the average size of survivors on a graph. Our results show that while surviving genera of mass extinctions tended to be slightly larger than those that went extinct, there was no significant difference. Even though the Permian (Changhsingian) and Triassic (Rhaetian) extinctions had larger surviving species, likewise the difference was small. Ecology had a more obvious impact on the likelihood of survival; fast-moving, predatory pelagic organisms were the most likely to go extinct, while sedentary, infaunal suspension feeders had the greatest chances of survival. Overall, ecology played a greater role than size in determining the survival of a species. With this information, we can use ecology to predict which species would survive future extinctions.

  7. Bactericidal Immunity to Salmonella in Africans and Mechanisms Causing Its Failure in HIV Infection.

    Directory of Open Access Journals (Sweden)

    Yun Shan Goh

    2016-04-01

    Full Text Available Nontyphoidal strains of Salmonella are a leading cause of death among HIV-infected Africans. Antibody-induced complement-mediated killing protects healthy Africans against Salmonella, but increased levels of anti-lipopolysaccharide (LPS antibodies in some HIV-infected African adults block this killing. The objective was to understand how these high levels of anti-LPS antibodies interfere with the killing of Salmonella.Sera and affinity-purified antibodies from African HIV-infected adults that failed to kill invasive S. Typhimurium D23580 were compared to sera from HIV-uninfected and HIV-infected subjects with bactericidal activity. The failure of sera from certain HIV-infected subjects to kill Salmonella was found to be due to an inherent inhibitory effect of anti-LPS antibodies. This inhibition was concentration-dependent and strongly associated with IgA and IgG2 anti-LPS antibodies (p<0.0001 for both. IgG anti-LPS antibodies, from sera of HIV-infected individuals that inhibit killing at high concentration, induced killing when diluted. Conversely, IgG, from sera of HIV-uninfected adults that induce killing, inhibited killing when concentrated. IgM anti-LPS antibodies from all subjects also induced Salmonella killing. Finally, the inhibitory effect of high concentrations of anti-LPS antibodies is seen with IgM as well as IgG and IgA. No correlation was found between affinity or avidity, or complement deposition or consumption, and inhibition of killing.IgG and IgM classes of anti-S. Typhimurium LPS antibodies from HIV-infected and HIV-uninfected individuals are bactericidal, while at very high concentrations, anti-LPS antibodies of all classes inhibit in vitro killing of Salmonella. This could be due to a variety of mechanisms relating to the poor ability of IgA and IgG2 to activate complement, and deposition of complement at sites where it cannot insert in the bacterial membrane. Vaccine trials are required to understand the significance of

  8. The Application of Bactericidal Silver Nanoparticles in Wound Treatment

    Directory of Open Access Journals (Sweden)

    Geewoo Nam

    2015-07-01

    Full Text Available Even with the prevalence of wounds, the medical technol‐ ogy for efficiently managing skin damage is still primitive. The disruption of any of the numerous healing processes can lead to problems in the time-sensitive healing actions of the dermal and epidermal layers. Bacterial infection is one of the major obstacles to proper wound healing as it poses a danger of causing long-term negative effects. Keeping the wound free of bacteria is imperative to the proper and hasty repair of dermal wounds. Silver has been widely used to treat wounds for its bactericidal properties. Although the mechanism of silver’s antibacterial action is not fully understood, it exhibits a significant antimicrobial efficacy against a wide spectrum of bacterial species. A number of different approaches to the mechanism are reported and presented in this review. Silver nanoparticles (AgNPs have been reported to exhibit enhanced antibac‐ terial activity due to their increased surface-area-to-volume ratio. AgNPs are capable of various modifications, signifi‐ cantly broadening the therapeutic properties of the mate‐ rial as a result. This review explores the different aspects of silver and silver nanoparticles, and their antibacterial properties, which can be applied in the field of wound treatments.

  9. Fabrication of nonfouling, bactericidal, and bacteria corpse release multifunctional surface through surface-initiated RAFT polymerization

    Directory of Open Access Journals (Sweden)

    Wang B

    2016-12-01

    Full Text Available Bailiang Wang,1,2 Zi Ye,1 Yihong Tang,1 Yuemei Han,1 Quankui Lin,1,2 Huihua Liu,2 Hao Chen,1,2 Kaihui Nan1,2 1School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, 2Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Sciences, Wenzhou, People’s Republic of China Abstract: Infections after surgery or endophthalmitis are potentially blinding complications caused by bacterial adhesion and subsequent biofilm formation on the intraocular lens. Neither single-function anti-adhesion surface nor contacting killing surface can exhibit ideal antibacterial function. In this work, a novel (2-(dimethylamino-ethyl methacrylate-co-2-methacryloyloxyethyl phosphorylcholine (p (DMAEMA-co-MPC brush was synthesized by “grafting from” method through reversible–addition fragmentation chain transfer polymerization. 1-Bromoheptane was used to quaternize the p (DMAEMA-co-MPC brush coating and to endow the surface with bactericidal function. The success of the surface functionalization was confirmed by atomic force microscopy, water contact angle, and spectroscopic ellipsometry. The quaternary ammonium salt units were employed as efficient disinfection that can eliminate bacteria through contact killing, whereas the 2-methacryloyloxyethyl phosphorylcholine units were introduced to suppress unwanted nonspecific adsorption. The functionalized poly(dimethyl siloxane surfaces showed efficiency in reducing bovine serum albumin adsorption and in inhibiting bacteria adhesion and biofilm formation. The copolymer brushes also demonstrated excellent bactericidal function against gram-positive (Staphylococcus aureus bacteria measured by bacteria live/dead staining and shake-flask culture methods. The surface biocompatibility was evaluated by morphology and activity measurement with human lens epithelial cells in vitro. The achievement of the p (DMAEMA+-co-MPC copolymer brush coating with nonfouling, bactericidal, and

  10. A versatile synthesis of highly bactericidal Myramistin (registered) stabilized silver nanoparticles

    International Nuclear Information System (INIS)

    Vertelov, G K; Krutyakov, Yu A; Olenin, A Yu; Lisichkin, G V; Efremenkova, O V

    2008-01-01

    Silver nanoparticles stabilized by a well-known antibacterial surfactant benzyldimethyl[3-(myristoylamino)propyl]ammonium chloride (Myramistin) were produced for the first time by borohydride reduction of silver chloride sol in water. Stable aqueous dispersions of silver nanoparticles without evident precipitation for several months could be obtained. In vitro bactericidal tests showed that Myramistin capped silver NPs exhibited notable activity against six different microorganisms-gram-positive and gram-negative bacteria, yeasts and fungi. The activity was up to 20 times higher (against E. coli) compared to Myramistin at the same concentrations and on average 2 times higher if compared with citrate-stabilized NPs

  11. Complement-mediated bactericidal activity of anti-factor H binding protein monoclonal antibodies against the meningococcus relies upon blocking factor H binding.

    Science.gov (United States)

    Giuntini, Serena; Reason, Donald C; Granoff, Dan M

    2011-09-01

    Binding of the complement-downregulating protein factor H (fH) to the surface of the meningococcus is important for survival of the organism in human serum. The meningococcal vaccine candidate factor H binding protein (fHbp) is an important ligand for human fH. While some fHbp-specific monoclonal antibodies (MAbs) block binding of fH to fHbp, the stoichiometry of blocking in the presence of high serum concentrations of fH and its effect on complement-mediated bactericidal activity are unknown. To investigate this question, we constructed chimeric antibodies in which the human IgG1 constant region was paired with three murine fHbp-specific binding domains designated JAR 3, JAR 5, and MAb502. By surface plasmon resonance, the association rates for binding of all three MAbs to immobilized fHbp were >50-fold higher than that for binding of fH to fHbp, and the MAb dissociation rates were >500-fold lower than that for fH. While all three MAbs elicited similar C1q-dependent C4b deposition on live bacteria (classical complement pathway), only those antibodies that inhibited binding of fH to fHbp (JAR 3 and JAR 5) had bactericidal activity with human complement. MAb502, which did not inhibit fH binding, had complement-mediated bactericidal activity only when tested with fH-depleted human complement. When an IgG1 anti-fHbp MAb binds to sparsely exposed fHbp on the bacterial surface, there appears to be insufficient complement activation for bacteriolysis unless fH binding also is inhibited. The ability of fHbp vaccines to elicit protective antibodies, therefore, is likely to be enhanced if the antibody repertoire is of high avidity and includes fH-blocking activity.

  12. Interaction between Allee effects caused by organism-environment feedback and by other ecological mechanisms.

    Directory of Open Access Journals (Sweden)

    Lijuan Qin

    Full Text Available Understanding Allee effect has crucial importance for ecological conservation and management because it is strongly related to population extinction. Due to various ecological mechanisms accounting for Allee effect, it is necessary to study the influence of multiple Allee effects on the dynamics and persistence of population. We here focus on organism-environment feedback which can incur strong, weak, and fatal Allee effect (AE-by-OEF, and further examine their interaction with the Allee effects caused by other ecological mechanisms (AE-by-OM. The results show that multiple Allee effects largely increase the extinction risk of population either due to the enlargement of Allee threshold or the change of inherent characteristic of Allee effect, and such an increase will be enhanced dramatically with increasing the strength of individual Allee effects. Our simulations explicitly considering spatial structure also demonstrate that local interaction among habitat patches can greatly mitigate such superimposed Allee effects as well as individual Allee effect. This implies that spatially structurized habitat could play an important role in ecological conservation and management.

  13. Interaction between Allee effects caused by organism-environment feedback and by other ecological mechanisms.

    Science.gov (United States)

    Qin, Lijuan; Zhang, Feng; Wang, Wanxiong; Song, Weixin

    2017-01-01

    Understanding Allee effect has crucial importance for ecological conservation and management because it is strongly related to population extinction. Due to various ecological mechanisms accounting for Allee effect, it is necessary to study the influence of multiple Allee effects on the dynamics and persistence of population. We here focus on organism-environment feedback which can incur strong, weak, and fatal Allee effect (AE-by-OEF), and further examine their interaction with the Allee effects caused by other ecological mechanisms (AE-by-OM). The results show that multiple Allee effects largely increase the extinction risk of population either due to the enlargement of Allee threshold or the change of inherent characteristic of Allee effect, and such an increase will be enhanced dramatically with increasing the strength of individual Allee effects. Our simulations explicitly considering spatial structure also demonstrate that local interaction among habitat patches can greatly mitigate such superimposed Allee effects as well as individual Allee effect. This implies that spatially structurized habitat could play an important role in ecological conservation and management.

  14. Bactericidal micron-thin sol-gel films prevent pin tract and periprosthetic infection.

    Science.gov (United States)

    Qu, Haibo; Knabe, Christine; Burke, Megan; Radin, Shula; Garino, Jonathan; Schaer, Thomas; Ducheyne, Paul

    2014-08-01

    Orthopedic injuries constitute the majority of wounds sustained by U.S. soldiers in recent conflicts. The risk of infection is considerable with fracture fixation devices. In this pilot study, we examined the use of unique bactericidal micron-thin sol-gel films on fracture fixation devices and their ability to prevent and eradicate infections. External fixation was studied with micron-thin sol-gel coated percutaneous pins releasing triclosan and inserted medially into rabbit tibiae. A total of 11 rabbits received percutaneous pins that were either uncoated or sol-gel/triclosan coated. Internal fracture fixation was also studied using sol-gel coated intramedullary (IM) nails releasing vancomycin in the intramedullary tibiae. Six sheep received IM nails that were coated with a sol-gel film that either contained vancomycin or did not contain vancomycin. All animals were challenged with Staphylococcus aureus around the implant. Animals were euthanized at 1 month postoperative. Rabbits receiving triclosan/sol-gel coated percutaneous pins did not show signs of infection. Uncoated percutaneous pins had a significantly higher infection rate. In the sheep study, there were no radiographic signs of osteomyelitis with vancomycin/sol-gel coated IM nails, in contrast to the observations in the control cohort. Hence, the nanostructured sol-gel controlled release technology offers the promise of a reliable and continuous delivery system of bactericidals from orthopedic devices to prevent and treat infection. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

  15. Enhanced bactericidal effect of enterocin A in combination with thyme essential oils against L. monocytogenes and E. coli O157:H7.

    Science.gov (United States)

    Ghrairi, Taoufik; Hani, Khaled

    2015-04-01

    The combined effects of enterocin A with Thymus vulgaris essential oils (EOs) against Listeria monocytogenes and Escherichia coli O157:H7 were investigated in vitro by enumeration of surviving populations of testing pathogens and minimal inhibitory concentration (MIC) determination. Enterocin A was purified to homogeneity by RP-HPLC from the culture fluid of Enterococcus strain and thyme EOs were extracted from local Thymus vulgaris plants. The major constituent of thyme EOs oils determined by GC-MS was thymol (78.4 %). Combination of enterocin A with thyme EOs showed an enhanced bactericidal effect against Listeria monocytogenes. Checkerboard assay and isobologram construction displayed a synergistic interaction between these compounds against Listeria (FIC index enterocin A has fallen fivefold (from 4.57 to 0.9 μg/ml), while the MIC of thyme EOs decreased threefold (from 3.6 to 1.2 μg/ml). Treatments with enterocin A alone did not affect the growth of the enteric pathogen E. coli O157:H7. However, the addition of thyme EOs and enterocin A yielded a synergistic antimicrobial effect against E. coli (MIC thyme EOs decrease from 2.2 to 0.71 μg/ml). This is the first report on the combined effect of enterocin A and thyme EOs against food pathogen bacteria. This combination could be useful in food bio-preservation.

  16. Effective ecological half-lives of Cs-137 for fishes controlled by their surrounding sea-waters

    International Nuclear Information System (INIS)

    Morita, T.; Yoshida, K.

    2004-01-01

    National Research Institute of Fisheries Science (NRIFS) has carried out the long term monitoring program for radioactive pollution in marine organisms caught around Japan in order to confirm the safety of marine organisms as food source. Main radionuclide in our monitoring program is Cs-137 because it has the relatively high radiotoxicity and the long term physical half-life (about 30.1 y), and tends to accumulate in the muscle. Recently, the effective ecological half-lives have been introduced to estimate the recovery time from radioactive pollution, and been applicable to various ecosystems. In this study, effective ecological half-lives of Cs-137 for some fishes were calculated from our long term monitoring data. It is known that fish species have each effective ecological half-lives. However, it has been unclear what change the effective ecological half-lives of Cs-137 for fishes. Fishes intake Cs-137 through food chain and directly from their surrounding sea-waters. Accordingly, the effective ecological half-lives of Cs-137 for some fishes would be controlled by the effective environment half-lives of Cs-137 for their surrounding sea-waters. There is difference in effective environment half-lives of Cs-137 between the open ocean and the coastal sea-waters because they have the different input sources of Cs-137. Some fishes move between the open ocean and the coastal areas, and therefore their effective ecological half-lives of Cs-137 are influenced by the effective environment half-lives of Cs-137 for sea-waters of both areas. Consequently, the differences in effective ecological half-lives of Cs-137 among fish species would depend the rate of coastal area in their lives. (author)

  17. An investigation of the bactericidal activity of selected essential oils to Aeromonas spp.

    Directory of Open Access Journals (Sweden)

    Clifford E. Starliper

    2015-01-01

    Full Text Available Diseases of fishes caused by Aeromonas spp. are common, have broad host ranges and may cause high mortality. Treatments of captive-reared populations using antimicrobials are limited with concerns for bacterial resistance development and environmental dissemination. This study was done to determine whether selected plant-derived essential oils were bactericidal to Aeromonas spp. Initially, twelve essential oils were evaluated using a disk diffusion assay to an isolate of A. salmonicida subsp. salmonicida, cause of fish furunculosis. The greatest zones of inhibition were obtained with oils of cinnamon Cinnamomum cassia, oregano Origanum vulgare, lemongrass Cymbopogon citratus and thyme Thymus vulgaris. Minimum bactericidal concentrations (MBC’s were determined for these four oils, Allimed® (garlic extract, Allium sativum and colloidal silver to sixty-nine isolates representing nine Aeromonas spp. The lowest mean MBCs (0.02–0.04% were obtained with three different sources of cinnamon oil. MBCs for three sources of oregano and lemongrass oils ranged from 0.14% to 0.30% and 0.10% to 0.65%, respectively, and for two thyme oils were 2.11% and 2.22%. The highest concentration (5% of Allimed® tested resulted in MBCs to twelve isolates. A concentration of silver greater than 15 mg/L would be required to determine MBCs for all but one isolate.

  18. A versatile synthesis of highly bactericidal Myramistin® stabilized silver nanoparticles

    Science.gov (United States)

    Vertelov, G. K.; Krutyakov, Yu A.; Efremenkova, O. V.; Olenin, A. Yu; Lisichkin, G. V.

    2008-09-01

    Silver nanoparticles stabilized by a well-known antibacterial surfactant benzyldimethyl[3-(myristoylamino)propyl]ammonium chloride (Myramistin®) were produced for the first time by borohydride reduction of silver chloride sol in water. Stable aqueous dispersions of silver nanoparticles without evident precipitation for several months could be obtained. In vitro bactericidal tests showed that Myramistin® capped silver NPs exhibited notable activity against six different microorganisms—gram-positive and gram-negative bacteria, yeasts and fungi. The activity was up to 20 times higher (against E. coli) compared to Myramistin® at the same concentrations and on average 2 times higher if compared with citrate-stabilized NPs.

  19. Integral statistical eco-indices - effective complementary tool for assessment of ecological state of and ecological risks for water ecosystems

    International Nuclear Information System (INIS)

    Bashamkova, I

    2010-01-01

    Eco-indices are successfully used for assessment of the ecological state and risks of water reservoirs. They allow, already at early stages, to detect negative effects on water ecosystems caused by progressive anthropogenic impacts and widening of the spectrum of pollutants, and to quantitatively evaluate ecological risks and damage for water reservoirs. Implementing these modern tools to water quality assessment is one of the lines to make decisions concerning challenging environmental problems.

  20. Bactericidal Antibiotics Increase Hydroxyphenyl Fluorescein Signal by Altering Cell Morphology

    DEFF Research Database (Denmark)

    Paulander, Wilhelm; Wang, Ying; Folkesson, Sven Anders

    2014-01-01

    It was recently proposed that for bactericidal antibiotics a common killing mechanism contributes to lethality involving indirect stimulation of hydroxyl radical (OH center dot) formation. Flow cytometric detection of OH center dot by hydroxyphenyl fluorescein (HPF) probe oxidation was used...... to support this hypothesis. Here we show that increased HPF signals in antibiotics-exposed bacterial cells are explained by fluorescence associated with increased cell size, and do not reflect reactive oxygen species (ROS) concentration. Independently of antibiotics, increased fluorescence was seen...... for elongated cells expressing the oxidative insensitive green fluorescent protein (GFP). Although our data question the role of ROS in lethality of antibiotics other research approaches point to important interplays between basic bacterial metabolism and antibiotic susceptibility. To underpin...

  1. Interactions between Genetic and Ecological Effects on the Evolution of Life Cycles.

    Science.gov (United States)

    Rescan, Marie; Lenormand, Thomas; Roze, Denis

    2016-01-01

    Sexual reproduction leads to an alternation between haploid and diploid phases, whose relative length varies widely across taxa. Previous genetical models showed that diploid or haploid life cycles may be favored, depending on dominance interactions and on effective recombination rates. By contrast, niche differentiation between haploids and diploids may favor biphasic life cycles, in which development occurs in both phases. In this article, we explore the interplay between genetical and ecological factors, assuming that deleterious mutations affect the competitivity of individuals within their ecological niche and allowing different effects of mutations in haploids and diploids (including antagonistic selection). We show that selection on a modifier gene affecting the relative length of both phases can be decomposed into a direct selection term favoring the phase with the highest mean fitness (due to either ecological differences or differential effects of mutations) and an indirect selection term favoring the phase in which selection is more efficient. When deleterious alleles occur at many loci and in the presence of ecological differentiation between haploids and diploids, evolutionary branching often occurs and leads to the stable coexistence of alleles coding for haploid and diploid cycles, while temporal variations in niche sizes may stabilize biphasic cycles.

  2. Ag loaded WO_3 nanoplates for efficient photocatalytic degradation of sulfanilamide and their bactericidal effect under visible light irradiation

    International Nuclear Information System (INIS)

    Zhu, Wenyu; Liu, Jincheng; Yu, Shuyan; Zhou, Yan; Yan, Xiaoli

    2016-01-01

    Highlights: • WO_3/Ag heterogeneous composites were fabricated with simply photo-reduction method. • Property changes due to Ag loading were systematically studied. • WO_3/Ag composites efficiently degraded sulfanilamide under visible light irradiation. • WO_3/Ag composites exhibited bactericidal effectS under visible light irradiation. - Abstract: Sulfonamides (SAs) are extensively used antibiotics and their residues in the water bodies propose potential threat to the public. In this study, degradation efficiency of sulfanilamide (SAM), which is the precursor of SAs, using WO_3 nanoplates and their Ag heterogeneous as photocatalysts was investigated. WO_3 nanoplates with uniform size were synthesized by a facile one step hydrothermal method. Different amount of Ag nanoparticles (Ag NPs) were loaded onto WO_3 nanoplates using a photo-reduction method to generate WO_3/Ag composites. The physio-chemical properties of synthesized nanomaterials were systematically characterized. Photodegradation of SAM by WO_3 and WO_3/Ag composites was conducted under visible light irradiation. The results show that WO_3/Ag composites performed much better than pure WO_3 where the highest removal rate was 96.2% in 5 h. Ag as excellent antibacterial agent also endows certain antibacterial efficiency to WO_3, and 100% removal efficiency against Escherichia Coli and Bacillus subtilis could be achieved in 2 h under visible light irradiation for all three WO_3/Ag composites synthesized. The improved performance in terms of SAM degradation and antibacterial activity of WO_3/Ag can be attributed to the improved electron-hole pair separation rate where Ag NPs act as effective electron trapper during the photocatalytic process.

  3. Bactericidal activity of culture fluid components of Lactobacillus fermentum strain 90 TS-4 (21) clone 3, and their capacity to modulate adhesion of Candida albicans yeast-like fungi to vaginal epithelial cells.

    Science.gov (United States)

    Anokhina, I V; Kravtsov, E G; Protsenko, A V; Yashina, N V; Yermolaev, A V; Chesnokova, V L; Dalin, M V

    2007-03-01

    Antagonistic activities of L. fermentum strain 90 TS-4 (21), L. casei ATCC 27216, and L. acidophilus ATCC 4356 and bactericidal activity of lactobacillus culture fluid towards E. coli strain K12, S. aureus, and S. epidermidis test cultures were studied. The bactericidal effect of L. fermentum strain 90 TS-4 (21) clone 3 culture fluid preparation (pH 6.0) on the test cultures was dose-dependent. Adhesion of C. albicans yeast-like fungi to vaginal epitheliocytes was more pronounced for strains isolated from women with asymptomatic infection than for strains isolated from women with manifest forms. L. fermentum strain 90 TS-4 (21) clone 3 culture fluid preparation modulated adhesion of yeast-like fungi only if the fungal strain was initially highly adherent.

  4. Bactericidal performance of visible-light responsive titania photocatalyst with silver nanostructures.

    Directory of Open Access Journals (Sweden)

    Ming-Show Wong

    Full Text Available BACKGROUND: Titania dioxide (TiO(2 photocatalyst is primarily induced by ultraviolet light irradiation. Visible-light responsive anion-doped TiO(2 photocatalysts contain higher quantum efficiency under sunlight and can be used safely in indoor settings without exposing to biohazardous ultraviolet light. The antibacterial efficiency, however, remains to be further improved. METHODOLOGY/PRINCIPAL FINDINGS: Using thermal reduction method, here we synthesized silver-nanostructures coated TiO(2 thin films that contain a high visible-light responsive antibacterial property. Among our tested titania substrates including TiO(2, carbon-doped TiO(2 [TiO(2 (C] and nitrogen-doped TiO(2 [TiO(2 (N], TiO(2 (N showed the best performance after silver coating. The synergistic antibacterial effect results approximately 5 log reductions of surviving bacteria of Escherichia coli, Streptococcus pyogenes, Staphylococcus aureus and Acinetobacter baumannii. Scanning electron microscope analysis indicated that crystalline silver formed unique wire-like nanostructures on TiO(2 (N substrates, while formed relatively straight and thicker rod-shaped precipitates on the other two titania materials. CONCLUSION/SIGNIFICANCE: Our results suggested that proper forms of silver on various titania materials could further influence the bactericidal property.

  5. Soedra's ecological forest management plans. Effects on production and economy

    International Nuclear Information System (INIS)

    Viklund, E.

    1998-01-01

    In 1995 SOEDRA Skog, Sweden's largest forest owners association, started making ecological forest management plans, Groena skogsbruksplaner. The ecological forest management plans are divided into different compartments in which the management is adapted to the present ecological conditions. The stands are divided into four different categories depending on the different values of nature conservation. The object of this study was to find an easy method to quantify and describe the effects of nature conservation on economy and forest production in SOEDRA:s ecological forest management plans. The developed and purposed method, called PLAN-metoden, does not consider the interests, measures beyond the period of the plan, or losses due to snow or wind. It calculates the difference between the purposed measures in the ecological management plan and an alternative with management according to the requirements of the present Forestry Act. The economic effects of nature conservation varies between a net profit of 0,3% and a cost of 9,1% when calculated with the cash-flow method. The average decrease of possible cutting of merchantable timber was 11,3% and varies between 3,1 and 32,9%. The average decrease of cutting possibilities was 12,9% and varies between a decrease of 0,7% and a decrease of 28,3% when calculated with a present value method. Mainly mature, well-stocked compartments, which are considered not to be managed in the future, give rise to high costs. Properties with unprofitable thinnings and costly scarification, regeneration and cleaning seem to be favoured by the nature conservation in the plans. The Ecological management plans are expected to be of great importance to the members of SOEDRA. The interest in nature conservation is larger than that of economical issues. In order to avoid unsatisfactory results the planning should be accomplished in close personal contact with the forest owner Examination paper 1998-1. 21 refs, 2 figs, 39 tabs

  6. Expanding the potential of NAI-107 for treating serious ESKAPE pathogens: synergistic combinations against Gram-negatives and bactericidal activity against non-dividing cells.

    Science.gov (United States)

    Brunati, Cristina; Thomsen, Thomas T; Gaspari, Eleonora; Maffioli, Sonia; Sosio, Margherita; Jabes, Daniela; Løbner-Olesen, Anders; Donadio, Stefano

    2018-02-01

    To characterize NAI-107 and related lantibiotics for their in vitro activity against Gram-negative pathogens, alone or in combination with polymyxin, and against non-dividing cells or biofilms of Staphylococcus aureus. NAI-107 was also evaluated for its propensity to select or induce self-resistance in Gram-positive bacteria. We used MIC determinations and chequerboard experiments to establish the antibacterial activity of the examined compounds against target microorganisms. Time-kill assays were used to evaluate killing of exponential and stationary-phase cells. The effects on biofilms (growth inhibition and biofilm eradication) were evaluated using biofilm-coated pegs. The frequency of spontaneous resistant mutants was evaluated by either direct plating or by continuous sub-culturing at 0.5 × MIC levels, followed by population analysis profiles. The results showed that NAI-107 and its brominated variant are highly active against Neisseria gonorrhoeae and some other fastidious Gram-negative pathogens. Furthermore, all compounds strongly synergized with polymyxin against Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa, and showed bactericidal activity. Surprisingly, NAI-107 alone was bactericidal against non-dividing A. baumannii cells. Against S. aureus, NAI-107 and related lantibiotics showed strong bactericidal activity against dividing and non-dividing cells. Activity was also observed against S. aureus biofilms. As expected for a lipid II binder, no significant resistance to NAI-107 was observed by direct plating or serial passages. Overall, the results of the current work, along with previously published results on the efficacy of NAI-107 in experimental models of infection, indicate that this lantibiotic represents a promising option in addressing the serious threat of antibiotic resistance. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial

  7. [Scale effect of Li-Xiang Railway construction impact on landscape pattern and its ecological risk].

    Science.gov (United States)

    Wang, De-zhi; Qiu, Peng-hua; Fang, Yuan-min

    2015-08-01

    As a large corridor project, plateau railway has multiple points and passes various sensitive environments along the railway. The determination of the scope of impact on ecological environment from railway construction is often controversial in ecological impact assessment work. Taking the Tangbu-Jiantang section of Li-Xiang Railway as study object, and using present land use map (1:10000) in 2012 and DEM as data sources, corridor cutting degree index ( CCI) and cumulative effect index of corridor (CCEI) were established by topology, buffer zone and landscape metrics methods. Besides, the ecological risk index used for railway construction was improved. By quantitative analysis of characteristics of the spatio-temporal change of landscape pattern and its evolution style at different spatial scales before and after railway construction, the most appropriate evaluation scale of the railway was obtained. Then the characteristics of the spatio-temporal variation of ecological risk within this scale before and after railway construction were analyzed. The results indicated that the cutting model and degree of railway corridor to various landscape types could be effectively reflected by CCI, and the exposure and harm relations between risk sources and risk receptors of railway can be measured by CCEI. After the railway construction, the railway corridor would cause a great deal of middle cutting effect on the landscape along the railroad, which would influence wood land and grassland landscape most greatly, while would cause less effect of edge cutting and internal cutting. Landscape indices within the 600 m buffer zone demonstrated the most obvious scale effect, therefore, the 600 m zone of the railway was set as the most suitable range of ecological impact assessment. Before railway construction, the low ecological risk level covered the biggest part of the 600 m assessment zone. However, after the railway construction, the ecological risk increased significantly, and

  8. Edge Effects and Ecological Traps: Effects on Shrubland Birds in Missouri

    Science.gov (United States)

    April A. Woodward; Alix D. Fink; Frank R. Thompson III

    2001-01-01

    The effect of habitat edge on avian nesting success has been the focus of considerable debate. We studied relationships between habitat edges, locations of nests, and predation. We tested the ecological trap hypothesis for 5 shrubland bird species in the Missouri Ozarks. We compared habitat selection and daily nest predation rates among 3 distance-to-edge categories....

  9. Downstream ecological effects of dams: A geomorphic perspective

    International Nuclear Information System (INIS)

    Ligon, F.K.; Dietrich, W.E.; Trush, W.J.

    1995-01-01

    The damming of a river changes the flow of water, sediment, nutrients, energy, and biota, interrupting and altering most of a river's ecological processes. This article discusses the importance of geomorphological analysis in river conservation and management. To illustrate how subtle geomorphological adjustments may profoundly influence the ecological relationships downstream from dames, three case studies are presented. Then a geomorphically based approach for assessing and possibly mitigating some of the environmental effects of dams by tailoring dam designed and operation is outlined. The cases are as follows: channel simplification and salmon decline on the McKenzie River in Oregon; Channel incision and reduced floodplain inundation on the Oconee river in Georgia; Increased stability of a braided river in New Zealand's south island. 41 refs., 10 figs., 1 tab

  10. Bactericidal Permeability-Increasing Proteins Shape Host-Microbe Interactions

    Directory of Open Access Journals (Sweden)

    Fangmin Chen

    2017-04-01

    Full Text Available We characterized bactericidal permeability-increasing proteins (BPIs of the squid Euprymna scolopes, EsBPI2 and EsBPI4. They have molecular characteristics typical of other animal BPIs, are closely related to one another, and nest phylogenetically among invertebrate BPIs. Purified EsBPIs had antimicrobial activity against the squid’s symbiont, Vibrio fischeri, which colonizes light organ crypt epithelia. Activity of both proteins was abrogated by heat treatment and coincubation with specific antibodies. Pretreatment under acidic conditions similar to those during symbiosis initiation rendered V. fischeri more resistant to the antimicrobial activity of the proteins. Immunocytochemistry localized EsBPIs to the symbiotic organ and other epithelial surfaces interacting with ambient seawater. The proteins differed in intracellular distribution. Further, whereas EsBPI4 was restricted to epithelia, EsBPI2 also occurred in blood and in a transient juvenile organ that mediates hatching. The data provide evidence that these BPIs play different defensive roles early in the life of E. scolopes, modulating interactions with the symbiont.

  11. Education in ecology

    International Nuclear Information System (INIS)

    Marek, R.

    1993-01-01

    It is not enough to convey knowledge, insights and attitudes if education in ecology is to have fruitful effects. Space and opportunity for action and creativity must be provided in addition. This includes personal consumer habits (eating, transport, hygiene, leisure activities etc.); an individual workplace - in this case school - that can be shaped according to ecological needs. Beyond this, ecological maturation should not be confined to, but should transcend school, for instance in youth groups, citizens' committees, political parties. If school does not inspire action - including action outside school -then education in ecology could be smothered by the Midas effect, where all life is reduced to material, to the curriculum in this case. This book presents ecological projects that have been tried at schools. They aim at an education in ecology that is oriented to the pupil and open to experience. They could be an incentive for colleagues to conduct similar projects at their schools. The projects work from the pupils' own experience and aim at concrete action and activities in his or her own environment. They should encourage teachers to venture outside the classroom with the pupils and teach ecology where it takes place. (orig.) [de

  12. Establishment of a National ecological network to conserve biodiversity. Pros and cons of ecological corridors Establishment of a National ecological network to conserve biodiversity. Pros and cons of ecological corridors

    Directory of Open Access Journals (Sweden)

    Laurent Bergès, Philip Roche and Catherine Avon

    2011-03-01

    Full Text Available Ecological corridors are a fundamental element in the National ecological network approved by the Grenelle environmental agreement in order to reduce ecosystem damage caused by fragmentation of the natural habitat zones of species. How can their effectiveness be evaluated? This article sums up current knowledge on their pros and cons.Fragmentation of natural habitats is considered one of the main causes of biodiversity loss. One of the proposed solutions to limit the effects of fragmentation is to restore ecological connectivity by creating ecological corridors between zones containing natural habitats. The concept remains controversial among scientists, but now serves as the basis for one of the operational projects of the Grenelle environmental agreements in the form of the National ecological network. After examining the ecological concepts justifying the political goal and presenting the various ecological roles of corridors, we briefly discuss their overall advantages and disadvantages. Then, we look closely at the methodological difficulties in detecting a corridor effect. Finally, we recommend a close partnership between research and policy to design biodiversity monitoring and evaluation systems in the different land-management plans.

  13. Ecological Effects of Grazing in the Northern Tianshan Mountains

    Directory of Open Access Journals (Sweden)

    Xiaotao Huang

    2017-11-01

    Full Text Available Identifying the effects of grazing is critical for the conservation, protection and sustainable use of arid grassland ecosystems. However, research regarding the ecological effects of grazing along mountainous elevation gradients is limited in arid areas, particularly at the regional scale. Using the Biome-BGC grazing model, we explored the effects of grazing on grassland net primary productivity (NPP, evapotranspiration (ET and water use efficiency (WUE from 1979 to 2012 along an elevation gradient in the northern Tianshan Mountains. The NPP, ET and WUE values were generally lower under the grazing scenario than under the ungrazed scenario; the differences between the grazing and ungrazed scenarios showed increasing trends over time; and distinct spatial heterogeneity in these differences was observed. Distinct decreases in NPP and WUE under the grazing scenario mainly occurred in regions with high livestock consumption. The decrease in ET was greater in mountainous areas with high grazing intensity due to decreased transpiration and increased surface runoff. This study contributes to a better understanding of the ecological effects of grazing along an elevation gradient in the northern Tianshan Mountains and provides data to support the scientific management of grassland ecosystems.

  14. The study of cellulosic fabrics impregnated with porphyrin compounds for use as photo-bactericidal polymers

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, Rahmatollah, E-mail: rahimi_rah@iust.ac.ir [Bioinorganic Chemistry Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114 (Iran, Islamic Republic of); Fayyaz, Fatemeh [Bioinorganic Chemistry Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114 (Iran, Islamic Republic of); Rassa, Mehdi [Department of Biology, Faculty of Science, University of Guilan, Rasht (Iran, Islamic Republic of)

    2016-02-01

    In the present work, we report on the preparation of cellulosic fabrics bearing two types of photo-sensitizers in order to prepare efficient polymeric materials for antimicrobial applications. The obtained porphyrin-grafted cellulosic fabrics were characterized by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, diffuse reflectance UV–Vis (DRUV) spectroscopy, thermo-gravimetric analysis (TG) and scanning electron microscopy (SEM). Antimicrobial activity of the prepared porphyrin-cellulose was tested under visible light irradiation against Staphylococcus aureus, Pseudomunas aeroginosa and Escherichia coli. In addition, the effect of two parameters on photo-bactericidal activity of treated fibers was studied: illumination time and concentration of photosensitizers (PS). - Highlights: • Cellulosic fabrics were impregnated with various concentrations of porphyrins (TAPP and its zinc ion complex). • The products were characterized by ATR-FTIR, DRUV, SEM and TG. • The photo-antibacterial activity of products was determined against S. aureus, P. aeroginosa and E. coli. • The effect of two parameters were studied on photoinactivation of treated fibers: illumination time and concentration of PS.

  15. [Ecology and ecologies].

    Science.gov (United States)

    Valera, Luca

    2011-01-01

    Ecology (from the Greek words οιχοσ, "house" and λογια "study of") is the science of the "house", since it studies the environments where we live. There are three main ways of thinking about Ecology: Ecology as the study of interactions (between humans and the environment, between humans and living beings, between all living beings, etc.), Ecology as the statistical study of interactions, Ecology as a faith, or rather as a science that requires a metaphysical view. The history of Ecology shows us how this view was released by the label of "folk sense" to gain the epistemological status of science, a science that strives to be interdisciplinary. So, the aim of Ecology is to study, through a scientific methodology, the whole natural world, answering to very different questions, that arise from several fields (Economics, Biology, Sociology, Philosophy, etc.). The plurality of issues that Ecology has to face led, during the Twentieth-century, to branch off in several different "ecologies". As a result, each one of these new approaches chose as its own field a more limited and specific portion of reality.

  16. Contribution of the autolysin AtlA to the bactericidal activity of amoxicillin against Enterococcus faecalis JH2-2.

    Science.gov (United States)

    Bravetti, Anne-Lise; Mesnage, Stéphane; Lefort, Agnès; Chau, Françoise; Eckert, Catherine; Garry, Louis; Arthur, Michel; Fantin, Bruno

    2009-04-01

    The bactericidal activity of amoxicillin was investigated against Enterococcus faecalis JH2-2 and against an isogenic mutant deficient in the production of the N-acetylglucosaminidase AtlA. Comparison of the two strains indicated that this autolysin contributes to killing by amoxicillin both in vitro and in a rabbit model of experimental endocarditis.

  17. The ecological importance of intraspecific variation.

    Science.gov (United States)

    Des Roches, Simone; Post, David M; Turley, Nash E; Bailey, Joseph K; Hendry, Andrew P; Kinnison, Michael T; Schweitzer, Jennifer A; Palkovacs, Eric P

    2018-01-01

    Human activity is causing wild populations to experience rapid trait change and local extirpation. The resulting effects on intraspecific variation could have substantial consequences for ecological processes and ecosystem services. Although researchers have long acknowledged that variation among species influences the surrounding environment, only recently has evidence accumulated for the ecological importance of variation within species. We conducted a meta-analysis comparing the ecological effects of variation within a species (intraspecific effects) with the effects of replacement or removal of that species (species effects). We evaluated direct and indirect ecological responses, including changes in abundance (or biomass), rates of ecological processes and changes in community composition. Our results show that intraspecific effects are often comparable to, and sometimes stronger than, species effects. Species effects tend to be larger for direct ecological responses (for example, through consumption), whereas intraspecific effects and species effects tend to be similar for indirect responses (for example, through trophic cascades). Intraspecific effects are especially strong when indirect interactions alter community composition. Our results summarize data from the first generation of studies examining the relative ecological effects of intraspecific variation. Our conclusions can help inform the design of future experiments and the formulation of strategies to quantify and conserve biodiversity.

  18. The effect of polyhexamethylene guanidine hydrochloride (PHMG) derivatives introduced into polylactide (PLA) on the activity of bacterial enzymes

    OpenAIRE

    Walczak, Maciej; Richert, Agnieszka; Burkowska-But, Aleksandra

    2014-01-01

    The present study was aimed at investigating bactericidal properties of polylactide (PLA) films containing three different polyhexamethylene guanidine hydrochloride (PHMG) derivatives and effect of the derivatives on extracellular hydrolytic enzymes and intracellular dehydrogenases. All PHMG derivatives had a slightly stronger bactericidal effect on Staphylococcus aureus than on E. coli but only PHMG granular polyethylene wax (at the concentration of at least 0.6 %) has a bactericidal effect....

  19. XF-73, a novel antistaphylococcal membrane-active agent with rapid bactericidal activity.

    Science.gov (United States)

    Ooi, Nicola; Miller, Keith; Hobbs, Joanne; Rhys-Williams, William; Love, William; Chopra, Ian

    2009-10-01

    XF-73 is a novel porphyrin antibacterial agent previously reported to inhibit a range of gram-positive bacterial species, including Staphylococcus aureus. Its mode of action is unknown. Using S. aureus as a model organism we sought to examine the basis of its antibacterial activity. The effects of XF-73 on the growth and survival of S. aureus SH1000 were investigated by viable count and culture absorbance techniques. Inhibition of macromolecular synthesis and disruption of membrane integrity after exposure to XF-73 were examined by radiolabelling experiments, the BacLight fluorescent dye assay and measurement of K(+) and ATP leakage from the cell. The effect of XF-73 on a staphylococcal coupled transcription-translation system was also investigated. XF-73 was rapidly bactericidal against S. aureus SH1000 and demonstrated more rapid killing kinetics than all other comparator agents when tested at an equivalent multiple (4x) of the MIC. Exposure of S. aureus to XF-73 for 10 min completely inhibited DNA, RNA and protein synthesis. XF-73 had no effect on transcription and translation in vitro. Cells exposed to XF-73 gave a positive response in the BacLight assay, which detects membrane damage. The drug also caused substantial loss of K(+) and ATP from the cell, but did not promote bacterial lysis. XF-73 exhibited rapid membrane-perturbing activity, which is likely to be responsible for inhibition of macromolecular synthesis and the death of staphylococci exposed to the drug.

  20. [Effects of land use structure change on regional ecological health--taking Shapingba County as an example].

    Science.gov (United States)

    Wang, Cheng; Wei, Chaofu; Gao, Ming; Luo, Guanglian; Jiang, Wei

    2005-12-01

    Land resource is the carrier for the exchange of matter, energy and information flows, while the change velocity and the intensity of land use has strong effects on the ecological processes such as matter circulation, energy flow, and biologic diversity. Land use structure change will alter the type, area, and spatial distribution of ecosystem, and in the meantime, result in the changes of regional ecological health. Employing the principles and methods of landscape ecology, and through endowing relative ecological value to land use type, this paper analyzed the charaeteristics of recent 10 years land use change in Shapingba County of Chongqing, and discussed the effects of land use change on regional ecological health, aimed to provide scientific references for land use planning and sustainable land resource utilization. The results indicated that transformation often occurred among different land use types, and the land use structure in each transformation phase differed quite obviously. Under different land use structure, there was a great disparity in relative ecological value of sub-ecosystems, which played various roles in regional ecological health. In general, the regional relative ecological value embodied both increase and decrease. In the future, the relative ecological value of sub-ecosystem would represent three tendencies, i.e., increase first and decrease then, continuous decrease, and continuous increase. The situation of regional ecological health would gradually become better.

  1. Spectroscopy investigation on chemo-catalytic, free radical scavenging and bactericidal properties of biogenic silver nanoparticles synthesized using Salicornia brachiata aqueous extract

    Science.gov (United States)

    Seralathan, Janani; Stevenson, Priscilla; Subramaniam, Shankar; Raghavan, Rachana; Pemaiah, Brindha; Sivasubramanian, Aravind; Veerappan, Anbazhagan

    2014-01-01

    Nanosized silver have been widely used in many applications, such as catalysis, photonics, sensors, medicine etc. Thus, there is an increasing need to develop high-yield, low cost, non-toxic and eco-friendly procedures for the synthesis of nanoparticles. Herein, we report an efficient, green synthesis of silver nanoparticles utilizing the aqueous extract of Salicornia brachiata, a tropical plant of the Chenopodiaceae family. Silver nanoparticles have been characterized by ultraviolet-visible spectroscopy, scanning electron microscopy and transmission electron microscopy. The morphology of the particles formed consists of highly diversified shapes like spherical, rod-like, prism, triangular, pentagonal and hexagonal pattern. However, addition of sodium hydroxide to the extract produces mostly spherical particles. The stable nanoparticles obtained using this green method show remarkable catalytic activity in the reduction of 4-nitro phenol to 4-amino phenol. The reduction catalyzed by silver nanoparticles followed the first-order kinetics, with a rate constant of, 0.6 × 10-2 s-1. The bactericidal activity of the synthesized silver nanoparticles against the pathogenic bacteria, Staphylococcus aureus, Staphylococcus aureus E, Bacillus subtilis and Escherichia coli, was also explored using REMA. The obtained results showed that the minimum inhibitory concentration required to induce bactericidal effect is lower than the control antibiotic, ciprofloxacin. In addition to these, the biogenic synthesized nanoparticles also exhibited excellent free radical scavenging activity.

  2. Ecological effects of fuel cycle activities

    Energy Technology Data Exchange (ETDEWEB)

    Barnthouse, L; Cada, G; Kroodsma, R; Shriner, D; Tolbert, V; Turner, R

    1994-07-01

    The purpose of this paper is to summarize the approach used to characterize ecological impacts of the coal fuel cycle. The same approach is used for many of the impacts in other fuel cycles as well. The principal analytical approach being used in the study is an accounting framework - that is, a series of matrices that map each phase of the fuel cycle to a suite of possible. emissions, each emission to a suite of impact categories, and each impact category to an external cost. This paper summarizes the ecological impacts of all phases of the coal fuel cycle, defines the ecological impact categories used in the study's 'accounting framework', and discusses alternative approaches to quantification. Externalities associated with CO{sub 2}-induced global climate change are beyond the scope of this paper and are not discussed.

  3. Ecological effects of fuel cycle activities

    International Nuclear Information System (INIS)

    Barnthouse, L.; Cada, G.; Kroodsma, R.; Shriner, D.; Tolbert, V.; Turner, R.

    1994-01-01

    The purpose of this paper is to summarize the approach used to characterize ecological impacts of the coal fuel cycle. The same approach is used for many of the impacts in other fuel cycles as well. The principal analytical approach being used in the study is an accounting framework - that is, a series of matrices that map each phase of the fuel cycle to a suite of possible. emissions, each emission to a suite of impact categories, and each impact category to an external cost. This paper summarizes the ecological impacts of all phases of the coal fuel cycle, defines the ecological impact categories used in the study's 'accounting framework', and discusses alternative approaches to quantification. Externalities associated with CO 2 -induced global climate change are beyond the scope of this paper and are not discussed

  4. Microwave, sonochemical and combustion synthesized CuO nanostructures and their electrical and bactericidal properties

    International Nuclear Information System (INIS)

    Karunakaran, C.; Manikandan, G.; Gomathisankar, P.

    2013-01-01

    Highlights: •CuO nanoleaves synthesized by CTAB-assisted hydrothermal method. •CuO nanodiscs synthesized by CTAB-assisted sonochemical method. •Combustion synthesized CuO is highly porous. •Synthetic method and morphology influence CuO bactericidal activity. -- Abstract: Cetyltrimethylammonium bromide (CTAB)-assisted microwave synthesis of CuO provides nanoleaves and in the absence of CTAB the shape of CuO is irregular. Sonochemical synthesis of CuO using CTAB gives nanodiscs whereas irregularly shaped flake-like structure is obtained without CTAB. Combustion synthesized CuO is highly porous with innumerable large holes. CTAB does not provide any structure in combustion synthesis. Transmission electron micrographs (TEM) display the constituent nanoparticles of microwave and sonochemically synthesized CuO. The powder X-ray diffractogram (XRD) shows the sample obtained by sonochemical method in the absence of CTAB as a mixture of monoclinic CuO, cubic Cu 2 O, and orthorhombic Cu(OH) 2 . But the rest of the samples are pure CuO in monoclinic phase. The selected area electron diffractograms (SAED) of the microwave and sonochemically synthesized samples, in the presence as well as in the absence of CTAB, confirm the monoclinic phase of CuO and indicates the presence of amorphous CuO in traces. All the samples are characteristic of Fourier Transform infrared (FT-IR) Cu–O stretching frequencies. The method of synthesis and also the morphology influence the electrical properties as well as the bactericidal activity of CuO

  5. Ecological aspects of the nuclear age: selected readings in radiation ecology

    International Nuclear Information System (INIS)

    Schultz, V.; Whicker, F.W.

    1971-01-01

    A compilation of selected readings is presented in the areas of radiation ecology, radionuclide cycling, ionizing radiation effects, radioisotope tracer techniques in ecology, and military and peaceful uses of nuclear energy

  6. Ecological tax reform - an optimal solution?. Critical remarks on the DIW study ''Economic effects of an ecological tax reform''

    International Nuclear Information System (INIS)

    Boehringer, C.; Fahl, H.; Voss, A.

    1994-01-01

    Through the latest expertise of the German institute for economic research (DIW) regarding an ecological tax reform, the discussion about a tax system considering the shortage of the ressource environment and a deficiency of demand regarding the ressource work is newly provoked. The focus of this article is a critical dealing with the methodical procedure of the German institute for economic reserarch when analyzing the national economic effect of a concretely formulated ecological tax law scenario. When assessing the overall economic consequences of a tax reform, it is recommended to use an analysis instrument, which is farly more consistent compared to the instruments by DIW, and which is more problem adequate through the increased resort to financial knowledge. Based on the obvious weakness of the DIW study, a more extensive comprehension for an ecological tax reform is pleaded for, standing out for an application of taxes based on division of labour and oriented to the objective. (orig./UA) [de

  7. Ag loaded WO{sub 3} nanoplates for efficient photocatalytic degradation of sulfanilamide and their bactericidal effect under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Wenyu [School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141 (Singapore); Liu, Jincheng, E-mail: JCLIU@ntu.edu.sg [School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Current address: Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510009 (China); Yu, Shuyan; Zhou, Yan [School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141 (Singapore); Yan, Xiaoli, E-mail: XLYAN@ntu.edu.sg [School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Current address: Environmental and Water Technology Centre of Innovation, Ngee Ann Polytechnic, 535 Clementi Road, Singapore 599489 (Singapore)

    2016-11-15

    Highlights: • WO{sub 3}/Ag heterogeneous composites were fabricated with simply photo-reduction method. • Property changes due to Ag loading were systematically studied. • WO{sub 3}/Ag composites efficiently degraded sulfanilamide under visible light irradiation. • WO{sub 3}/Ag composites exhibited bactericidal effectS under visible light irradiation. - Abstract: Sulfonamides (SAs) are extensively used antibiotics and their residues in the water bodies propose potential threat to the public. In this study, degradation efficiency of sulfanilamide (SAM), which is the precursor of SAs, using WO{sub 3} nanoplates and their Ag heterogeneous as photocatalysts was investigated. WO{sub 3} nanoplates with uniform size were synthesized by a facile one step hydrothermal method. Different amount of Ag nanoparticles (Ag NPs) were loaded onto WO{sub 3} nanoplates using a photo-reduction method to generate WO{sub 3}/Ag composites. The physio-chemical properties of synthesized nanomaterials were systematically characterized. Photodegradation of SAM by WO{sub 3} and WO{sub 3}/Ag composites was conducted under visible light irradiation. The results show that WO{sub 3}/Ag composites performed much better than pure WO{sub 3} where the highest removal rate was 96.2% in 5 h. Ag as excellent antibacterial agent also endows certain antibacterial efficiency to WO{sub 3}, and 100% removal efficiency against Escherichia Coli and Bacillus subtilis could be achieved in 2 h under visible light irradiation for all three WO{sub 3}/Ag composites synthesized. The improved performance in terms of SAM degradation and antibacterial activity of WO{sub 3}/Ag can be attributed to the improved electron-hole pair separation rate where Ag NPs act as effective electron trapper during the photocatalytic process.

  8. FORUM: Effective management of ecological resilience – are we there yet?

    Science.gov (United States)

    Spears, Bryan M.; Ives, Stephen C.; Angeler, David G.; Allen, Craig R.; Birk, Sebastian; Carvalho, Laurence; Cavers, Stephen; Daunt, Francis; Morton, R. Daniel; Pocock, Michael J. O.; Rhodes, Glenn; Thackeray, Stephen J.

    2015-01-01

    Ecological resilience is developing into a credible paradigm for policy development and environmental management for preserving natural capital in a rapidly changing world. However, resilience emerges from complex interactions, limiting the translation of theory into practice.Main limitations include the following: (i) difficulty in quantification and detection of changes in ecological resilience, (ii) a lack of empirical evidence to support preventative or proactive management and (iii) difficulties in managing processes operating across socio-ecological systems that vary in space and time.We highlight recent research with the potential to address these limitations including new and/or improved indicators of resilience and tools to assess scale as a driver of resilience.Synthesis and applications. Effective resilience-based management must be adaptive in nature. To support this, we propose an operational model using resilience-based iterative management actions operating across scales.

  9. Granulated wood ash to forest soil - Ecological effects

    International Nuclear Information System (INIS)

    Rosen, K.; Eriksson, H.; Clarholm, M.; Lundkvist, H.; Rudebeck, A.

    1993-01-01

    This report describes research concerning ecological effects of wood ash recycling to forest soils. The main part of the minerals in the wood fuels are retained in the ashes after combustion. By returning the ashes back to the cleared forest areas, the mineral losses can be reduced. Adding ashes and limestone is a method to vitalize acidified forest soils and restore the production capacity. 48 refs, 26 figs, 8 tabs

  10. Silver-loaded nanotubular structures enhanced bactericidal efficiency of antibiotics with synergistic effect in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Xu N

    2017-01-01

    -positive Staphylococcus aureus (ATCC 25923, and methicillin-resistant Staphylococcus aureus (MRSA; ATCC 33591 and ATCC 43300. Moreover, after a relative short (3 weeks combinational treatment, animal experiments in vivo further proved the synergistic antibacterial effect by X-ray and histological and immunohistochemical analyses. These results demonstrated that the combination of Ag nanoparticles and antibiotics significantly enhanced the antibacterial effect both in vitro and in vivo through the synergistic effect. The strategy is promising for clinical application to reduce the usage of antibiotics and shorten the administration time of implant-associated infection. Keywords: implant-associated infection, silver nanoparticles, TiO2 nanotube, antibiotics, synergistic bactericidal activity

  11. Ecological effects assessment: requirements vs state-of-the-art

    International Nuclear Information System (INIS)

    McKenzie, D.H.; Thomas, J.M.; Eberhardt, L.L.

    1981-05-01

    Concerns for environmental quality, the ecologist's understanding of ecosystems, and the ability to quantitatively sample and evaluate hypotheses have contributed to current requirements and the state-of-the-art in ecological effects assessments in refard to nuclear power plants. The current cooling system approaches, data collection programs, and ecological effects assessments reflect these contributions. Over a decade of experience provides the basis for a timely review and evaluation of current proactice. The magnitude of economic and environmental resources being committed to cooling system alternatives mandates that the decision-making process result in as many optimal choices as possible. In addition, the resources being devoted to environmental data collection and integration provide considerable motivation for providing meaningful input to the decision-making process. It is maintained that the input should be as quantitative and as free from subjective content as is reasonably possible. An alternative viewpoint suggests that the past several decades of experience be considered but a first step, and the current task to be one of designing a second step

  12. [Ecological carrying capacity and Chongming Island's ecological construction].

    Science.gov (United States)

    Wang, Kaiyun; Zou, Chunjing; Kong, Zhenghong; Wang, Tianhou; Chen, Xiaoyong

    2005-12-01

    This paper overviewed the goals of Chongming Island's ecological construction and its background, analyzed the current eco-economic status and constraints of the Island, and put forward some scientific issues on its ecological construction. It was suggested that for the resources-saving and sustainable development of the Island, the researches on its ecological construction should be based on its ecological carrying capacity, fully take the regional characteristics into consideration, and refer the successful development modes at home and abroad. The carrying capacity study should ground on systemic and dynamic views, give a thorough evaluation of the Island's present carrying capacity, simulate its possible changes, and forecast its demands and risks. Operable countermeasures to promote the Island's carrying capacity should be worked out, new industry structure, population scale, and optimized distribution projects conforming to regional carrying capacity should be formulated, and effective ecological security alarming and control system should be built, with the aim of providing suggestions and strategic evidences for the decision-making of economic development and sustainable environmental resources use of the region.

  13. Preparation of AgBr@SiO{sub 2} core@shell hybrid nanoparticles and their bactericidal activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuanyuan [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Yang, Lisu [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Henna Sports School, Zhengzhou 450045 (China); Zhao, Yanbao, E-mail: yanbaozhao@126.com [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Li, Binjie; Sun, Lei; Luo, Huajuan [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China)

    2013-04-01

    AgBr@SiO{sub 2} core@shell hybrid nanoparticles (NPs) were successfully prepared by sol-gel method. Their morphology and structure were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The hybrid NPs are predominantly spherical in shape, with an average diameter of 180–200 nm, and each NP contains one inorganic core. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the hybrid NPs were examined against Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli), respectively. Results indicated that the AgBr@SiO{sub 2} NPs had excellent antibacterial activity. - Highlights: ► Presents a novel antibacterial agent “AgBr@ SiO{sub 2} NPs”. ► AgBr@SiO{sub 2} hybrid NPs could provide long-term antimicrobial effect. ► AgBr@SiO{sub 2} hybrid NPs have excellent antibacterial activity.

  14. Biofilm-forming activity of bacteria isolated from toilet bowl biofilms and the bactericidal activity of disinfectants against the isolates.

    Science.gov (United States)

    Mori, Miho; Gomi, Mitsuhiro; Matsumune, Norihiko; Niizeki, Kazuma; Sakagami, Yoshikazu

    2013-01-01

    To evaluate the sanitary conditions of toilets, the bacterial counts of the toilet bowl biofilms in 5 Kansai area and 11 Kansai and Kanto area homes in Japan were measured in winter and summer seasons, respectively. Isolates (128 strains) were identified by analyzing 16S ribosomal RNA sequences. The number of colonies and bacterial species from biofilms sampled in winter tended to be higher and lower, respectively, than those in summer. Moreover, the composition of bacterial communities in summer and winter samples differed considerably. In summer samples, biofilms in Kansai and Kanto areas were dominated by Blastomonas sp. and Mycobacterium sp., respectively. Methylobacterium sp. was detected in all toilet bowl biofilms except for one sample. Methylobacterium sp. constituted the major presence in biofilms along with Brevundimonas sp., Sphingomonas sp., and/or Pseudomonas sp. The composition ratio of the sum of their genera was 88.0 from 42.9% of the total bacterial flora. The biofilm formation abilities of 128 isolates were investigated, and results suggested that Methylobacterium sp. and Sphingomonas sp. were involved in biofilm formation in toilet bowls. The biofilm formation of a mixed bacteria system that included bacteria with the highest biofilm-forming ability in a winter sample was greater than mixture without such bacteria. This result suggests that isolates possessing a high biofilm-forming activity are involved in the biofilm formation in the actual toilet bowl. A bactericidal test against 25 strains indicated that the bactericidal activities of didecyldimethylammonium chloride (DDAC) tended to be higher than those of polyhexamethylene biguanide (PHMB) and N-benzyl-N,N-dimethyldodecylammonium chloride (ADBAC). In particular, DDAC showed high bactericidal activity against approximately 90% of tested strains under the 5 h treatment.

  15. Superior bactericidal activity of N-bromine compounds compared to their N-chlorine analogues can be reversed under protein load.

    Science.gov (United States)

    Gottardi, W; Klotz, S; Nagl, M

    2014-06-01

    To investigate and compare the bactericidal activity (BA) of active bromine and chlorine compounds in the absence and presence of protein load. Quantitative killing tests against Escherichia coli and Staphylococcus aureus were performed both in the absence and in the presence of peptone with pairs of isosteric active chlorine and bromine compounds: hypochlorous and hypobromous acid (HOCl and HOBr), dichloro- and dibromoisocyanuric acid, chlorantine and bromantine (1,3-dibromo- and 1,3 dichloro-5,5-dimethylhydantoine), chloramine T and bromamine T (N-chloro- and N-bromo-4-methylbenzenesulphonamide sodium), and N-chloro- and N-bromotaurine sodium. To classify the bactericidal activities on a quantitative basis, an empirical coefficient named specific bactericidal activity (SBA), founded on the parameters of killing curves, was defined: SBA= mean log reductions/(mean exposure times x concentration) [mmol 1(-1) min (-1)]. In the absence of peptone, tests with washed micro-organisms revealed a throughout higher BA of bromine compounds with only slight differences between single substances. This was in contrast to chlorine compounds, whose killing times differed by a factor of more than four decimal powers. As a consequence, also the isosteric pairs showed according differences. In the presence of peptone, however, bromine compounds showed an increased loss of BA, which partly caused a reversal of efficacy within isosteric pairs. In medical practice, weakly oxidizing active chlorine compounds like chloramines have the highest potential as topical anti-infectives in the presence of proteinaceous material (mucous membranes, open wounds). Active bromine compounds, on the other hand, have their chance at insensitive body regions with low organic matter, for example skin surfaces. The expected protein load is one of the most important parameters for selection of a suited active halogen compound. © 2014 The Society for Applied Microbiology.

  16. Ecological stability of landscape - ecological infrastructure - ecological management

    International Nuclear Information System (INIS)

    1992-01-01

    The Field Workshop 'Ecological Stability of Landscape - Ecological Infrastructure - Ecological Management' was held within a State Environmental Programme financed by the Federal Committee for the Environment. The objectives of the workshop were to present Czech and Slovak approaches to the ecological stability of the landscape by means of examples of some case studies in the field, and to exchange ideas, theoretical knowledge and practical experience on implementing the concept of ecological infrastructure in landscape management. Out of 19 papers contained in the proceedings, 3 items were inputted to the INIS system. (Z.S.)

  17. Cumulative ecological and socioeconomic effects of forest policies in coastal Oregon.

    Science.gov (United States)

    T.A. Spies; K.N. Johnson; K.M. Burnett; J.L. Ohmann; B.C. McComb; G.H. Reeves; P. Bettinger; J.D. Kline; B. Garber-Yonts

    2007-01-01

    Forest biodiversity policies in multiownership landscapes are typically developed in an uncoordinated fashion with little consideration of their interactions or possible unintended cumulative effects. We conducted an assessment of some of the ecological and socioeconomic effects of recently enacted forest management policies in the 2.3-million-ha Coast Range...

  18. Novel two-tiered approach of ecological risk assessment for pesticide mixtures based on joint effects.

    Science.gov (United States)

    Tian, Dayong; Mao, Haichen; Lv, Huichao; Zheng, Yong; Peng, Conghu; Hou, Shaogang

    2018-02-01

    Ecological risk assessments for mixtures have attracted considerable attention. In this study, 38 pesticides in the real environment were taken as objects and their toxicities to different organisms from three trophic levels were employed to assess the ecological risk of the mixture. The first tier assessment was based on the CA effect and the obtained sum of risk quotients (SRQ species-CA ) were 3.06-9.22. The second tier assessment was based on non-CA effects and the calculated SRQ species-TU are 5.37-9.29 using joint effects (TU sum ) as modified coefficients, which is higher than SRQ species-CA and indicates that ignoring joint effects might run the risk of underestimating the actual impact of pesticide mixtures. Due to the influences of synergistic and antagonistic effects, risk contribution of components to mixture risks based on non-CA effects are different from those based on the CA effect. Moreover, it was found that the top 8 dominating components explained 95.5%-99.8% of mixture risks in this study. The dominating components are similar in the two tiers for a given species. Accordingly, a novel two-tiered approach was proposed to assess the ecological risks of mixtures based on joint effects. This study provides new insights for ecological risk assessments with the consideration of joint effects of components in the pesticide mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Effect of complement Factor H on anti-FHbp serum bactericidal antibody responses of infant rhesus macaques boosted with a licensed meningococcal serogroup B vaccine.

    Science.gov (United States)

    Giuntini, Serena; Beernink, Peter T; Granoff, Dan M

    2015-12-16

    FHbp is a major serogroup B meningococcal vaccine antigen. Binding of complement Factor H (FH) to FHbp is specific for human and some non-human primate FH. In previous studies, FH binding to FHbp vaccines impaired protective anti-FHbp antibody responses. In this study we investigated anti-FHbp antibody responses to a third dose of a licensed serogroup B vaccine (MenB-4C) in infant macaques vaccinated in a previous study with MenB-4C. Six macaques with high binding of FH to FHbp (FH(high)), and six with FH(low) baseline phenotypes, were immunized three months after dose 2. After dose 2, macaques with the FH(low) baseline phenotype had serum anti-FHbp antibodies that enhanced FH binding to FHbp (functionally converting them to a FH(high) phenotype). In this group, activation of the classical complement pathway (C4b deposition) by serum anti-FHbp antibody, and anti-FHbp serum bactericidal titers were lower after dose 3 than after dose 2 (pb deposition and bactericidal titers were similar after doses 2 and 3. Two macaques developed serum anti-FH autoantibodies after dose 2, which were not detected after dose 3. In conclusion, in macaques with the FH(low) baseline phenotype whose post-dose 2 serum anti-FHbp antibodies had converted them to FH(high), the anti-FHbp antibody repertoire to dose 3 was skewed to less protective epitopes than after dose 2. Mutant FHbp vaccines that eliminate FH binding may avoid eliciting anti-FHbp antibodies that enhance FH binding, and confer greater protection with less risk of inducing anti-FH autoantibodies than FHbp vaccines that bind FH. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Use of ecological exposure units in ecological risk assessment

    International Nuclear Information System (INIS)

    Ferenbaugh, R.; Myers, O.; Gallegos, A.; Breshears, D.; Ebinger, M.

    1995-01-01

    The traditional approach to ecological risk assessment at hazardous waste sites that are being evaluated for cleanup under CERCLA or RCRA requirements is to focus on the immediate impacts at or adjacent to a site. While this may be acceptable in some situations, it is not ecologically defensible in situations where there are numerous contaminated sites in proximity to each other. In the latter case, transport from the sites, potential cumulative effects, and wide-ranging receptors must be considered. The concept of the Ecological Exposure Unit (EEU) has been proposed to address this situation. Ecological Exposure Units are defined on the basis of ecological considerations and each EEU may contain several to many contaminated sites. The initial steps involved in performing ecological risk assessments using the EEU approach include (1) selection of appropriate receptors and assessment endpoints, and (2) geographical definition of EEUs. At Los Alamos National Laboratory, receptors have been identified and EEUs have been defined for these receptors. GIS is being used as a tool to map EEUs. Receptors include representatives from threatened or endangered species, species reflecting status of ecological health, species with social or cultural relevance, and other species of concern. After definition of EEUs, cumulative impacts of all stressors at all sites within each EEU must be evaluated. The two major advantages to performing ecological risk assessments using this approach are that risk assessments are performed in a more scientifically defensible manner because they are performed on ecologically defined units and that resources are used optimally by minimizing redundant remedial activities

  1. Survival of Bactericidal Antibiotic Treatment by a Persister Subpopulation of Listeria monocytogenes

    DEFF Research Database (Denmark)

    Knudsen, Gitte Maegaard; Ng, Yin; Gram, Lone

    2013-01-01

    Listeria monocytogenes can cause the serious infection listeriosis, which despite antibiotic treatment has a high mortality. Understanding the response of L. monocytogenes to antibiotic exposure is therefore important to ensure treatment success. Some bacteria survive antibiotic treatment...... by formation of persisters, which are a dormant antibiotic-tolerant subpopulation. The purpose of this study was to determine whether L. monocytogenes can form persisters and how bacterial physiology affects the number of persisters in the population. A stationary-phase culture of L. monocytogenes was adjusted...... that eradication of persisters is possible. Our study adds L. monocytogenes to the list of bacterial species capable of surviving bactericidal antibiotics in a dormant stage, and this persister phenomenon should be borne in mind when developing treatment regimens....

  2. Indirect Effects of Global Change: From Physiological and Behavioral Mechanisms to Ecological Consequences.

    Science.gov (United States)

    Gunderson, Alex R; Tsukimura, Brian; Stillman, Jonathon H

    2017-07-01

    A major focus of current ecological research is to understand how global change makes species vulnerable to extirpation. To date, mechanistic ecophysiological analyses of global change vulnerability have focused primarily on the direct effects of changing abiotic conditions on whole-organism physiological traits, such as metabolic rate, locomotor performance, cardiac function, and critical thermal limits. However, species do not live in isolation within their physical environments, and direct effects of climate change are likely to be compounded by indirect effects that result from altered interactions with other species, such as competitors and predators. The Society for Integrative and Comparative Biology 2017 Symposium "Indirect Effects of Global Change: From Physiological and Behavioral Mechanisms to Ecological Consequences" was designed to synthesize multiple approaches to investigating the indirect effects of global change by bringing together researchers that study the indirect effects of global change from multiple perspectives across habitat, type of anthropogenic change, and level of biological organization. Our goal in bringing together researchers from different backgrounds was to foster cross-disciplinary insights into the mechanistic bases and higher-order ecological consequences of indirect effects of global change, and to promote collaboration among fields. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  3. Ecological effect of rare earth elements

    International Nuclear Information System (INIS)

    Hu Aitang; Zhou Quansuo; Zheng Shaojian; Zhai Hai; Zhao Xiulan; Pang Yonglin; Wang Yuqi; Sun Jingxin; Zhang Shen; Wang Lijun

    1997-01-01

    Water and soil culture were carried out to study the ecological effect of rare earth elements (REEs) in the aspect of plant-soil system. Contents of REEs were determined by instrumental neutron activation analysis (INAA). There was a limit to REEs-tolerance of crops, which differed with the development periods of plant and soil types. The REEs concentration in plant, especially in root, was marked related to the concentration in culture material. Beyond the concentration-limit appeared phototoxicity. The chemical behavior of REEs in plants and soils varied with soil types and elements. The bio-availability of REEs in soil mainly depended on the exchangeable fraction of REEs affected strongly by the physi-chemical properties of soils

  4. Quantifying the effects of ecological constraints on trait expression using novel trait-gradient analysis parameters.

    Science.gov (United States)

    Ottaviani, Gianluigi; Tsakalos, James L; Keppel, Gunnar; Mucina, Ladislav

    2018-01-01

    Complex processes related to biotic and abiotic forces can impose limitations to assembly and composition of plant communities. Quantifying the effects of these constraints on plant functional traits across environmental gradients, and among communities, remains challenging. We define ecological constraint ( C i ) as the combined, limiting effect of biotic interactions and environmental filtering on trait expression (i.e., the mean value and range of functional traits). Here, we propose a set of novel parameters to quantify this constraint by extending the trait-gradient analysis (TGA) methodology. The key parameter is ecological constraint, which is dimensionless and can be measured at various scales, for example, on population and community levels. It facilitates comparing the effects of ecological constraints on trait expressions across environmental gradients, as well as within and among communities. We illustrate the implementation of the proposed parameters using the bark thickness of 14 woody species along an aridity gradient on granite outcrops in southwestern Australia. We found a positive correlation between increasing environmental stress and strength of ecological constraint on bark thickness expression. Also, plants from more stressful habitats (shrublands on shallow soils and in sun-exposed locations) displayed higher ecological constraint for bark thickness than plants in more benign habitats (woodlands on deep soils and in sheltered locations). The relative ease of calculation and dimensionless nature of C i allow it to be readily implemented at various scales and make it widely applicable. It therefore has the potential to advance the mechanistic understanding of the ecological processes shaping trait expression. Some future applications of the new parameters could be investigating the patterns of ecological constraints (1) among communities from different regions, (2) on different traits across similar environmental gradients, and (3) for the same

  5. Ecological effects of harvesting biomass for energy in the Spanish Mediterranean

    International Nuclear Information System (INIS)

    Zavala, Miguel A.; Marcos, Francisco

    1993-01-01

    Biomass utilization for energy has major consequences for Spanish Mediterranean landscapes. In this paper we present a synthesis of the ecological effects of harvesting biomass for energy. We compare these effects with other fuel reduction procedures such as prescribed burning. Throughout history we see that some Iberian ecosystems are stabilized by long human interference. One of the stabilizing factors is the utilization of wood as a source of energy. New energy sources and massive human movements towards urban areas have changed the ecosystem dynamics. Reforested areas in Spain during the period from 1940 to 1970 included silviculture treatments that in some cases never took place. This has led to a greater accumulation of biomass. The current perspective of the problem must be analyzed from an economic and political viewpoint. For instance, the Middle East crisis has direct consequences for the budget dedicated to forest energetics, and consequently for the landscape. This shows how ecological problems must be dealt with using a very broad perspective. In Spain current biomass usage should be considered primarily as a complementary silvicultural treatment rather than as a way of producing great biomass outputs. If we are going to manage our forest from an ecological perspective, we have to analyze the effects of these operations at the stand level. At the landscape level fuel management plans should be included in the Forest Management Prescriptions (ordenaciones) whether in terms of harvesting or in a prescribed burning plan

  6. Concentrations of lipopolysaccharide-binding protein, bactericidal/permeability-increasing protein, soluble CD14 and plasma lipids in relation to endotoxaemia in patients with alcoholic liver disease

    DEFF Research Database (Denmark)

    Schäfer, C.; Parlesak, Alexandr; Schütt, C.

    2002-01-01

    of endotoxin on its target cells (LPS-binding protein and sCD14) were increased. Endotoxin antagonists, such as bactericidal/permeability-increasing protein and high-density lipoprotein, were increased in the pre-cirrhotic stages, whereas a significant reduction of the latter was observed in cirrhosis. Low......-density lipoprotein remained unchanged. The elevation of binding factors in the pre-cirrhotic stages of alcoholic liver disease might attenuate the effects of endotoxaemia, whereas in cirrhosis the reduction of high density lipoprotein, to which large quantities of endotoxin bind, may contribute to its pro...

  7. Assessing ecological effects of radionuclides: data gaps and extrapolation issues

    International Nuclear Information System (INIS)

    Garnier-Laplace, Jacqueline; Gilek, Michael; Sundell-Bergman, Synnoeve; Larsson, Carl-Magnus

    2004-01-01

    By inspection of the FASSET database on radiation effects on non-human biota, one of the major difficulties in the implementation of ecological risk assessments for radioactive pollutants is found to be the lack of data for chronic low-level exposure. A critical review is provided of a number of extrapolation issues that arise in undertaking an ecological risk assessment: acute versus chronic exposure regime; radiation quality including relative biological effectiveness and radiation weighting factors; biological effects from an individual to a population level, including radiosensitivity and lifestyle variations throughout the life cycle; single radionuclide versus multi-contaminants. The specificities of the environmental situations of interest (mainly chronic low-level exposure regimes) emphasise the importance of reproductive parameters governing the demography of the population within a given ecosystem and, as a consequence, the structure and functioning of that ecosystem. As an operational conclusion to keep in mind for any site-specific risk assessment, the present state-of-the-art on extrapolation issues allows us to grade the magnitude of the uncertainties as follows: one species to another > acute to chronic = external to internal = mixture of stressors> individual to population> ecosystem structure to function

  8. Ecological effects from transuranium elements in terrestrial environment

    International Nuclear Information System (INIS)

    Uiker, F.U.

    1985-01-01

    To understand ecological effects from transuranium elements in environment it is necessary to know how their chemical, physical and biological behaviour depends on duration of their being in natural environment. It is necesary to take into account that behaviour of transuranium elements in environment depends on physical and chemical forms of a nuclide as well as on characteristics of ecosystem. Radiation dose of certain tissues plays an essential role here but dose distribution is especially complicated for relatively non-soluble α-irradiators

  9. Calcium and Zinc Containing Bactericidal Glass Coatings for Biomedical Metallic Substrates

    Directory of Open Access Journals (Sweden)

    Leticia Esteban-Tejeda

    2014-07-01

    Full Text Available The present work presents new bactericidal coatings, based on two families of non-toxic, antimicrobial glasses belonging to B2O3–SiO2–Na2O–ZnO and SiO2–Na2O–Al2O3–CaO–B2O3 systems. Free of cracking, single layer direct coatings on different biomedical metallic substrates (titanium alloy, Nb, Ta, and stainless steel have been developed. Thermal expansion mismatch was adjusted by changing glass composition of the glass type, as well as the firing atmosphere (air or Ar according to the biomedical metallic substrates. Formation of bubbles in some of the glassy coatings has been rationalized considering the reactions that take place at the different metal/coating interfaces. All the obtained coatings were proven to be strongly antibacterial versus Escherichia coli (>4 log.

  10. Complement activation and formation of the membrane attack complex on serogroup B Neisseria meningitidis in the presence or absence of serum bactericidal activity

    NARCIS (Netherlands)

    Drogari-Apiranthitou, M.; Kuijper, E. J.; Dekker, N. [=Nick; Dankert, J.

    2002-01-01

    Encapsulated meningococci are complement sensitive only in the presence of bactericidal antibodies by yet-unexplored mechanisms. The objective of this study was to investigate the involvement of major bacterial surface constituents on complement activation and membrane attack complex (MAC) formation

  11. In vitro assessment of the bactericidal effect of low-power arsenium-gallium (AsGa laser treatment Avaliação in vitro da ação bactericida do laser de baixa potência (AsGa

    Directory of Open Access Journals (Sweden)

    Adilvania Ferreira da Costa

    2012-08-01

    Full Text Available The objective of the present study was to perform an in vitro evaluation of the bactericidal action of a low-power arsenium-gallium (AsGa laser at a wavelength of 904nm and energy density of 6 J/cm². Ten petri dishes were seeded with Pseudomonas aeruginosa and another ten with Staphylococcus aureus. The dishes were then randomly divided into four groups with five plates in each group. Two groups were treated with AsGa laser once a day for 5 days, while the other two groups received no treatment. No halo of growth inhibition was found in any of the groups. It was therefore concluded that laser treatment (AsGa, 904nm, 6J/cm² had no bactericidal effect.Verificar, in vitro, o efeito bactericida do laser de baixa potência, AsGa, 904nm, na dose 6 J/cm2. Foram semeadas 10 placas de Petri com a bactéria Pseudomonas aeruginosa e 10 placas de Petri com Staphylococcus aureus. Aleatoriamente, foram divididas em quatro grupos (5 placas cada: dois grupos foram tratados com o laser AsGa a cada 24 horas, durante cinco dias, e dois grupos não receberam tratamento. Em todos os grupos, não foi observado qualquer halo de inibição do crescimento. Assim, concluiuse que a terapia a laser (AsGa, 904nm, 6 J/cm² não produziu efeito bactericida.

  12. Ecological risk estimation

    International Nuclear Information System (INIS)

    Bartell, S.M.; Gardner, R.H.; O'Neill, R.V.

    1992-01-01

    Ecological risk assessment, the process that evaluates the likelihood that adverse ecological effects may occur or are occurring as a result of exposure to one or more stressors, is being developed by the US EPA as a tool for decision making. This book presents one approach to risk assessment-that of applying laboratory toxicity data within an ecosystem model to predict the potential ecological consequences of toxic chemicals. Both Standard Water Column Model (SWACOM), using zooplankton and fish, and Monte Carlo simulations are discussed in detail, along with quantitative explanations for many responses. Simplifying assumptions are explicitly presented. The final chapter discusses strengths, weaknesses, and future directions of the approach. The book is appropriate for anyone who does or uses ecological risk assessment methodologies

  13. Comparing spatially explicit ecological and social values for natural areas to identify effective conservation strategies.

    Science.gov (United States)

    Bryan, Brett Anthony; Raymond, Christopher Mark; Crossman, Neville David; King, Darran

    2011-02-01

    Consideration of the social values people assign to relatively undisturbed native ecosystems is critical for the success of science-based conservation plans. We used an interview process to identify and map social values assigned to 31 ecosystem services provided by natural areas in an agricultural landscape in southern Australia. We then modeled the spatial distribution of 12 components of ecological value commonly used in setting spatial conservation priorities. We used the analytical hierarchy process to weight these components and used multiattribute utility theory to combine them into a single spatial layer of ecological value. Social values assigned to natural areas were negatively correlated with ecological values overall, but were positively correlated with some components of ecological value. In terms of the spatial distribution of values, people valued protected areas, whereas those natural areas underrepresented in the reserve system were of higher ecological value. The habitats of threatened animal species were assigned both high ecological value and high social value. Only small areas were assigned both high ecological value and high social value in the study area, whereas large areas of high ecological value were of low social value, and vice versa. We used the assigned ecological and social values to identify different conservation strategies (e.g., information sharing, community engagement, incentive payments) that may be effective for specific areas. We suggest that consideration of both ecological and social values in selection of conservation strategies can enhance the success of science-based conservation planning. ©2010 Society for Conservation Biology.

  14. Plant selenium hyperaccumulation- Ecological effects and potential implications for selenium cycling and community structure.

    Science.gov (United States)

    Reynolds, R Jason B; Pilon-Smits, Elizabeth A H

    2018-04-25

    Selenium (Se) hyperaccumulation occurs in ~50 plant taxa native to seleniferous soils in Western USA. Hyperaccumulator tissue Se levels, 1000-15,000 mg/kg dry weight, are typically 100 times higher than surrounding vegetation. Relative to other species, hyperaccumulators also transform Se more into organic forms. We review abiotic and biotic factors influencing soil Se distribution and bioavailability, soil being the source of the Se in hyperaccumulators. Next, we summarize the fate of Se in plants, particularly hyperaccumulators. We then extensively review the impact of plant Se accumulation on ecological interactions. Finally, we discuss the potential impact of Se hyperaccumulators on local community composition and Se cycling. Selenium (hyper)accumulation offers ecological advantages: protection from herbivores and pathogens and competitive advantage over other plants. The extreme Se levels in and around hyperaccumulators create a toxic environment for Se-sensitive ecological partners, while offering a niche for Se-resistant partners. Through these dual effects, hyperaccumulators may influence species composition in their local environment, as well as Se cycling. The implied effects of Se hyperaccumulation on community assembly and local Se cycling warrant further investigations into the contribution of hyperaccumulators and general terrestrial vegetation to global Se cycling and may serve as a case study for how trace elements influence ecological processes. Furthermore, understanding ecological implications of plant Se accumulation are vital for safe implementation of biofortification and phytoremediation, technologies increasingly implemented to battle Se deficiency and toxicity. Copyright © 2018. Published by Elsevier B.V.

  15. Agrobacterium-mediated genetic transformation of Pogostemon cablin (Blanco) Benth. Using leaf explants: bactericidal effect of leaf extracts and counteracting strategies.

    Science.gov (United States)

    Paul, Anamika; Bakshi, Souvika; Sahoo, Debee Prasad; Kalita, Mohan Chandra; Sahoo, Lingaraj

    2012-04-01

    An optimized protocol for Agrobacterium tumefaciens-mediated transformation of patchouli using leaf disk explants is reported. In vitro antibacterial activity of leaf extracts of the plants revealed Agrobacterium sensitivity to the extracts. Fluorometric assay of bacterial cell viability indicated dose-dependent cytotoxic activity of callus extract against Agrobacterium cells. Addition of 0.1% Tween 20 and 2 g/l L-glutamine to Agrobacterium infection medium counteracted the bactericidal effect and significantly increased the T-DNA delivery to explants. A short preculture of explants for 2 days followed by infection with Agrobacterium in medium containing 150 μM of acetosyringone were found essential for efficient T-DNA delivery. Cocultivation for 3 days at 22 °C in conjunction with other optimized factors resulted in maximum T-DNA delivery. The Agrobacterium-mediated transformation of leaf disk explants were found significantly related to physiological age of the explants, age and origin of the of the donor plant. Leaf explants from second node of the 3-month-old in vivo plants showed highest transformation efficiency (94.3%) revealed by transient GUS expression assay. Plants selected on medium containing 20 mg/l kanamycin showed stable GUS expression in leaves and stem. The elongated shoots readily developed roots on kanamycin-free rooting medium and on transfer to soil, plants were successfully established. Polymerase chain reaction (PCR) and reverse-transcriptase PCR analysis in putative plants confirmed their transgenic nature. The established transformation method should provide new opportunities for the genetic improvement of patchouli for desirable trait.

  16. Ecological validity of cost-effectiveness models of universal HPV vaccination: A systematic literature review.

    Science.gov (United States)

    Favato, Giampiero; Easton, Tania; Vecchiato, Riccardo; Noikokyris, Emmanouil

    2017-05-09

    The protective (herd) effect of the selective vaccination of pubertal girls against human papillomavirus (HPV) implies a high probability that one of the two partners involved in intercourse is immunised, hence preventing the other from this sexually transmitted infection. The dynamic transmission models used to inform immunisation policy should include consideration of sexual behaviours and population mixing in order to demonstrate an ecological validity, whereby the scenarios modelled remain faithful to the real-life social and cultural context. The primary aim of this review is to test the ecological validity of the universal HPV vaccination cost-effectiveness modelling available in the published literature. The research protocol related to this systematic review has been registered in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42016034145). Eight published economic evaluations were reviewed. None of the studies showed due consideration of the complexities of human sexual behaviour and the impact this may have on the transmission of HPV. Our findings indicate that all the included models might be affected by a different degree of ecological bias, which implies an inability to reflect the natural demographic and behavioural trends in their outcomes and, consequently, to accurately inform public healthcare policy. In particular, ecological bias have the effect to over-estimate the preference-based outcomes of selective immunisation. A relatively small (15-20%) over-estimation of quality-adjusted life years (QALYs) gained with selective immunisation programmes could induce a significant error in the estimate of cost-effectiveness of universal immunisation, by inflating its incremental cost effectiveness ratio (ICER) beyond the acceptability threshold. The results modelled here demonstrate the limitations of the cost-effectiveness studies for HPV vaccination, and highlight the concern that public healthcare policy might have been

  17. Enhanced biomimic bactericidal surfaces by coating with positively-charged ZIF nano-dagger arrays.

    Science.gov (United States)

    Yuan, Yuan; Zhang, Yugen

    2017-10-01

    Cicada wing surfaces are covered with dense patterns of nano-pillar structure that prevent bacterial growth by rupturing adhered microbial cells. To mimic the natural nano-pillar structure, we developed a general and simple method to grow metal organic framework (MOF) nano-dagger arrays on a wide range of surfaces. These nano-daggers possess high bactericidal activity, with log reduction >7 for Escherichia coli and Staphylococcus aureus. It was hypothesized that the positively-charged ZIF-L nano-dagger surfaces enhance bacterial cell adhesion, facilitating selective and efficient bacteria killing by the rigid and sharp nano-dagger tips. This research provides a safe and clean antimicrobial surface technology which does not require external chemicals and will not cause drug resistance. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Toward effective ecological risk-management of refinery corrective action

    International Nuclear Information System (INIS)

    Metzger, B.H.; Rury, P.M.; Turton, D.; Archibald, B.; Clark, J.; Cura, J.

    1995-01-01

    Cleanup of complex industrial sites, such as refineries, requires risk-based decision tools to ensure that environmentally protective remediation is consistent with current and future land use. However, conventional ecological risk assessment approaches are not well suited for complex industrial sites. Site risk assessments focus on hypothetical chemical risk assuming diverse and undisturbed ecosystems, rather than industrial and disturbed area conditions. In addition, they offer little guidance as to how to make timely and effective risk management decisions. An innovative methodology is proposed to assist industry and regulatory risk managers with rapid EcoRisk reconnaissance and cost-effective remedial decision-making at complex industrial sites. Phase 1 comprises a three-step risk screening of areas of ecological concern at the site, which integrates habitat quality characteristics and potential chemical hazards. It yields an ordering of areas as follows: areas of no significant risk; areas of potentially significant risk; and areas of likely significant risk. A decision rule is then applied to determine appropriate risk management action, including: no action; additional study; and remedial or management action. In Phase 2, additional study is conducted for areas that exhibit potentially significant risk so as to facilitate risk management. This methodology is currently being applied at the 1,300 acre, former Exxon Bayway Refinery in New Jersey

  19. Agglutinating and bactericidal properties of fractions of rabbit anti-Vibrio cholerae serum.

    Science.gov (United States)

    Pike, R M; Chandler, C H

    1969-06-01

    The major portion of the agglutinating and bactericidal activity of the sera of rabbits immunized with live Vibrio cholerae or with cholera vaccine was found in the gammaM fractions during the early stages of immunization. After 5 weeks or more, gammaG fractions accounted for more than half of the agglutinating activity. When late antibody was measured as the amount of protein precipitated by somatic antigens, nearly 3 times as much gammaG as gammaM was required for agglutination, and about 30 times as much gammaG as gammaM was required to kill 50% of a standard inoculum in the presence of complement. The ratio of vibriocidal to agglutinin titer of gammaG fractions at different stages of immunization was more variable than that of gammaM fractions. More complement was required for a vibriocidal effect by gammaG than by gammaM. Increasing the amount of complement decreased the amount of both gammaG and gammaM required to kill, but smaller amounts of gammaM required disproportionately larger amounts of complement. Less time was required by gammaM than by gammaG to kill 50% of the inoculum. Removal of the group-reactive antibody from anti-Ogawa serum and serum fractions by absorption with Inaba reduced the vibriocidal titer by more than one-half.

  20. Synergistic antibacterial effects of β-lactam antibiotic combined with silver nanoparticles

    Science.gov (United States)

    Li, Ping; Li, Juan; Wu, Changzhu; Wu, Qingsheng; Li, Jian

    2005-09-01

    The bactericidal action of silver (0) nanoparticles and amoxicillin on Escherichia coli is studied, respectively. Increasing concentration of both amoxicillin (0-0.525 mg ml-1) and silver nanoparticles (0-40 µg ml-1) showed a higher antibacterial effect in Luria-Bertani (LB) medium. Escherichia coli cells have different bactericidal sensitivity to them. When amoxicillin and silver nanoparticles are combined, it results in greater bactericidal efficiency on Escherichia coli cells than when they were applied separately. Dynamic tests on bacterial growth indicated that exponential and stationary phases are greatly decreased and delayed in the synergistic effect of amoxicillin and silver nanoparticles. In addition, the effect induced by a preincubation with silver nanoparticles is examined. The results show that solutions with more silver nanoparticles have better antimicrobial effects. One hypothesized mechanism is proposed to explain this phenomenon.

  1. Self-DNA inhibitory effects: Underlying mechanisms and ecological implications.

    Science.gov (United States)

    Cartenì, Fabrizio; Bonanomi, Giuliano; Giannino, Francesco; Incerti, Guido; Vincenot, Christian Ernest; Chiusano, Maria Luisa; Mazzoleni, Stefano

    2016-01-01

    DNA is usually known as the molecule that carries the instructions necessary for cell functioning and genetic inheritance. A recent discovery reported a new functional role for extracellular DNA. After fragmentation, either by natural or artificial decomposition, small DNA molecules (between ∼50 and ∼2000 bp) exert a species specific inhibitory effect on individuals of the same species. Evidence shows that such effect occurs for a wide range of organisms, suggesting a general biological process. In this paper we explore the possible molecular mechanisms behind those findings and discuss the ecological implications, specifically those related to plant species coexistence.

  2. Bactericidal effectiveness of modulated UV light

    International Nuclear Information System (INIS)

    Bank, H.L.; John, J.; Schmehl, M.K.; Dratch, R.J.

    1990-01-01

    Studies were designed to evaluate the effectiveness of pulsed modulated UV light waveforms for killing bacteria. Exposure of five strains of bacteria to the modulated information encoded in the light decreased the colony population from a confluent lawn to less than 20 colonies. However, approximately 2,000 colonies survived treatment with the same intensity and time of exposure to UV light lacking the modulated information

  3. School Effectiveness in Ecological Perspective.

    Science.gov (United States)

    Bronfenbrenner, Urie; Hamilton, Stephen F.

    This report focuses on the learning and development of primary and secondary school children, employing an "ecology of human development" model. This model is defined as involving the scientific study of the accommodation between growing human beings and the changing immediate settings in which they live and learn. The conceptual framework for the…

  4. Meta-analysis in applied ecology.

    Science.gov (United States)

    Stewart, Gavin

    2010-02-23

    This overview examines research synthesis in applied ecology and conservation. Vote counting and pooling unweighted averages are widespread despite the superiority of syntheses based on weighted combination of effects. Such analyses allow exploration of methodological uncertainty in addition to consistency of effects across species, space and time, but exploring heterogeneity remains controversial. Meta-analyses are required to generalize in ecology, and to inform evidence-based decision-making, but the more sophisticated statistical techniques and registers of research used in other disciplines must be employed in ecology to fully realize their benefits.

  5. Radiation ecological monitoring in NPP region

    International Nuclear Information System (INIS)

    Egorov, Yu.A.; Kazakov, S.V.

    1985-01-01

    The known principle of sanitary-hygienic regulation of NPP radiation effect on man and environment is analyzed. An ecological approach is required to optimize NPP relations with the environment and to regulate radioactivity of the NPP - environment system. The ecological approach envisages the development of standards of permissible concentrations of radioactive and chemical substances (as well as heat) in natural environment, taking into account their synergism, corresponding to ecologically permissible response reactions of biota to their effect. The ecological approach also comprises the sanitary-hygienic principle of radiation protection of man. Attention is paid to ecological monitoring in NPP region, comprising consideration of factors, affecting the environment, evaluation of the actual state of the environment, prediction of the environmental state, evaluation of the expected environmental state

  6. Effects of season on ecological processes in extensive earthen tilapia ponds in Southeastern Brazil.

    Science.gov (United States)

    Favaro, E G P; Sipaúba-Tavares, L H; Milstein, A

    2015-11-01

    In Southeastern Brazil tilapia culture is conducted in extensive and semi-intensive flow-through earthen ponds, being water availability and flow management different in the rainy and dry seasons. In this region lettuce wastes are a potential cheap input for tilapia culture. This study examined the ecological processes developing during the rainy and dry seasons in three extensive flow-through earthen tilapia ponds fertilized with lettuce wastes. Water quality, plankton and sediment parameters were sampled monthly during a year. Factor analysis was used to identify the ecological processes occurring within the ponds and to construct a conceptual graphic model of the pond ecosystem functioning during the rainy and dry seasons. Processes related to nitrogen cycling presented differences between both seasons while processes related to phosphorus cycling did not. Ecological differences among ponds were due to effects of wind protection by surrounding vegetation, organic loading entering, tilapia density and its grazing pressure on zooplankton. Differences in tilapia growth among ponds were related to stocking density and ecological process affecting tilapia food availability and intraspecific competition. Lettuce wastes addition into the ponds did not produce negative effects, thus this practice may be considered a disposal option and a low-cost input source for tilapia, at least at the amounts applied in this study.

  7. Minimum bactericidal concentration of phenols extracted from oil vegetation water on spoilers, starters and food-borne bacteria

    Directory of Open Access Journals (Sweden)

    Luca Fasolato

    2015-05-01

    Full Text Available The aim of the study was to assess the in vitro effect of phenols extracted from oil vegetation water (PEOW on several food-borne strains. Antibacterial activity of PEOW was based on the minimum bactericidal concentration (MBC on microtitre assay. The taxa tested were: Staphylococcus (n. 5, Listeria (n. 4, Escherichia (n. 2, Salmonella (n. 1, Pseudomonas (n. 3, Lactobacillus (n. 2 and Pediococcus (n. 1. S. aureus and L. monocytogens showed the lowest level of resistance to PEOW (MBC=1.5-3 mg/mL. In contrast, the Gram negative strains (e.g. S. Typhimurium and Pseudomonas spp. were in some cases unaffected by the tested doses and the MBCs ranged between 6 to 12 mg/mL. Starter cultures were dramatically reduced on growth (e.g. Staphylococcus xylosus; 0.75 mg/mL MBC. The thresholds for pathogenic strains could be considered for further applications of PEOW in food models (e.g. shelf life or challenge test studies.

  8. The effect of mining on landscape ecological systems and land reclamation

    International Nuclear Information System (INIS)

    Stys, S.

    1991-01-01

    Coal mining causes serious disturbance of the environment. Basic principles for the reclamation of affected territories are discussed. The effects of mining on the socio-ecological landscape system, the agricultural and forestry aspects of reclamation technologies after surface mining and the factors affecting the way of reclamation are shown in a diagrammatic form. The attached photographs document the effect of mining on landscape devastation. (M.D.). 17 figs

  9. Bactericidal activity of M protein conserved region antibodies against group A streptococcal isolates from the Northern Thai population

    Directory of Open Access Journals (Sweden)

    Pruksachatkunakorn Chulabhorn

    2006-08-01

    Full Text Available Abstract Background Most group A streptococcal (GAS vaccine strategies have focused on the surface M protein, a major virulence factor of GAS. The amino-terminus of the M protein elicits antibodies, that are both opsonic and protective, but which are type specific. J14, a chimeric peptide that contains 14 amino acids from the M protein conserved C-region at the carboxy-terminus, offers the possibility of a vaccine which will elicit protective opsonic antibodies against multiple different GAS strains. In this study, we searched for J14 and J14-like sequences and the number of their repeats in the C-region of the M protein from GAS strains isolated from the Northern Thai population. Then, we examined the bactericidal activity of J14, J14.1, J14-R1 and J14-R2 antisera against multiple Thai GAS strains. Results The emm genes of GAS isolates were sequenced and grouped as 14 different J14-types. The most diversity of J14-types was found in the C1-repeat. The J14.1 type was the major sequence in the C2 and C3-repeats. We have shown that antisera raised against the M protein conserved C-repeat region peptides, J14, J14.1, J14-R1 and J14-R2, commonly found in GAS isolates from the Northern Thai population, are able to kill GAS of multiple different emm types derived from an endemic area. The mean percent of bactericidal activities for all J14 and J14-like peptide antisera against GAS isolates were more than 70%. The mean percent of bactericidal activity was highest for J14 antisera followed by J14-R2, J14.1 and J14-R1 antisera. Conclusion Our study demonstrated that antisera raised against the M protein conserved C-repeat region are able to kill multiple different strains of GAS isolated from the Northern Thai population. Therefore, the four conserved "J14" peptides have the potential to be used as GAS vaccine candidates to prevent streptococcal infections in an endemic area.

  10. Missing ecology: integrating ecological perspectives with the social-ecological system framework

    Directory of Open Access Journals (Sweden)

    Graham Epstein

    2013-08-01

    Full Text Available The social-ecological systems framework was designed to provide a common research tool for interdisciplinary investigations of social-ecological systems. However, its origin in institutional studies of the commons belies its interdisciplinary ambitions and highlights its relatively limited attention to ecology and natural scientific knowledge. This paper considers the biophysical components of the framework and its epistemological foundations as it relates to the incorporation of knowledge from the natural sciences. It finds that the mixture of inductive and deductive reasoning associated with socially-oriented investigations of these systems is lacking on the ecological side, which relies upon induction alone. As a result the paper proposes the addition of a seventh core sub-system to the social-ecological systems framework, ecological rules, which would allow scholars to explicitly incorporate knowledge from the natural sciences for deductive reasoning. The paper shows, through an instructive case study, how the addition of ecological rules can provide a more nuanced description of the factors that contribute to outcomes in social-ecological systems.

  11. Serum bactericidal assay for the evaluation of typhoid vaccine using a semi-automated colony-counting method.

    Science.gov (United States)

    Jang, Mi Seon; Sahastrabuddhe, Sushant; Yun, Cheol-Heui; Han, Seung Hyun; Yang, Jae Seung

    2016-08-01

    Typhoid fever, mainly caused by Salmonella enterica serovar Typhi (S. Typhi), is a life-threatening disease, mostly in developing countries. Enzyme-linked immunosorbent assay (ELISA) is widely used to quantify antibodies against S. Typhi in serum but does not provide information about functional antibody titers. Although the serum bactericidal assay (SBA) using an agar plate is often used to measure functional antibody titers against various bacterial pathogens in clinical specimens, it has rarely been used for typhoid vaccines because it is time-consuming and labor-intensive. In the present study, we established an improved SBA against S. Typhi using a semi-automated colony-counting system with a square agar plate harboring 24 samples. The semi-automated SBA efficiently measured bactericidal titers of sera from individuals immunized with S. Typhi Vi polysaccharide vaccines. The assay specifically responded to S. Typhi Ty2 but not to other irrelevant enteric bacteria including Vibrio cholerae and Shigella flexneri. Baby rabbit complement was more appropriate source for the SBA against S. Typhi than complements from adult rabbit, guinea pig, and human. We also examined the correlation between SBA and ELISA for measuring antibody responses against S. Typhi using pre- and post-vaccination sera from 18 human volunteers. The SBA titer showed a good correlation with anti-Vi IgG quantity in the serum as determined by Spearman correlation coefficient of 0.737 (P measure functional antibody titers against S. Typhi in sera from human subjects immunized with typhoid vaccines. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Delayed bactericidal response of Mycobacterium tuberculosis to bedaquiline involves remodelling of bacterial metabolism

    DEFF Research Database (Denmark)

    Koul, A.; Vranckx, L.; Dhar, N.

    2014-01-01

    Bedaquiline (BDQ), an ATP synthase inhibitor, is the first drug to be approved for treatment of multidrug-resistant tuberculosis in decades. Though BDQ has shown excellent efficacy in clinical trials, its early bactericidal activity during the first week of chemotherapy is minimal. Here, using...... microfluidic devices and time-lapse microscopy of Mycobacterium tuberculosis, we confirm the absence of significant bacteriolytic activity during the first 3-4 days of exposure to BDQ. BDQ-induced inhibition of ATP synthesis leads to bacteriostasis within hours after drug addition. Transcriptional...... and proteomic analyses reveal that M. tuberculosis responds to BDQ by induction of the dormancy regulon and activation of ATP-generating pathways, thereby maintaining bacterial viability during initial drug exposure. BDQ-induced bacterial killing is significantly enhanced when the mycobacteria are grown on non...

  13. Ecological safety of thermal power industry and investments

    International Nuclear Information System (INIS)

    Glebov, V.P.

    1995-01-01

    Evaluation of ecological safety of domestic fossil fuel thermal power industry is given in comparison with foreign one. Ways of solving ecological problems are considered. They are based on introduction of new technologies, providing decrease of ecological effect, on development of effective ash-and sulfur-trapping, nitrogen purification equipment, on production of ecologically improved fuel. The necessity of investments to power industry is noted

  14. Effects of Global Warming on Vibrio Ecology.

    Science.gov (United States)

    Vezzulli, Luigi; Pezzati, Elisabetta; Brettar, Ingrid; Höfle, Manfred; Pruzzo, Carla

    2015-06-01

    Vibrio-related infections are increasing worldwide both in humans and aquatic animals. Rise in global sea surface temperature (SST), which is approximately 1 °C higher now than 140 years ago and is one of the primary physical impacts of global warming, has been linked to such increases. In this chapter, major known effects of increasing SST on the biology and ecology of vibrios are described. They include the effects on bacterial growth rate, both in the field and in laboratory, culturability, expression of pathogenicity traits, and interactions with aquatic organisms and abiotic surfaces. Special emphasis is given to the effect of ocean warming on Vibrio interactions with zooplankters, which represent one of the most important aquatic reservoirs for these bacteria. The reported findings highlight the biocomplexity of the interactions between vibrios and their natural environment in a climate change scenario, posing the need for interdisciplinary studies to properly understand the connection between ocean warming and persistence and spread of vibrios in sea waters and the epidemiology of the diseases they cause.

  15. Framework for ecological risk assessment

    International Nuclear Information System (INIS)

    Rodier, D.; Norton, S.

    1992-02-01

    Increased interest in ecological issues such as global climate change, habitat loss, acid deposition, reduced biological diversity, and the ecological impacts of pesticides and toxic chemicals prompts this U.S. Environmental Protection Agency (EPA) report, A Framework for Ecological Risk Assessment ('Framework Report'). The report describes basic elements, or a framework, for evaluating scientific information on the adverse effects of physical and chemical stressors on the environment. The framework offers starting principles and a simple structure as guidance for current ecological risk assessments and as a foundation for future EPA proposals for risk assessment guidelines

  16. Cumulative Effects Assessment: Linking Social, Ecological, and Governance Dimensions

    Directory of Open Access Journals (Sweden)

    Marian Weber

    2012-06-01

    Full Text Available Setting social, economic, and ecological objectives is ultimately a process of social choice informed by science. In this special feature we provide a multidisciplinary framework for the use of cumulative effects assessment in land use planning. Forest ecosystems are facing considerable challenges driven by population growth and increasing demands for resources. In a suite of case studies that span the boreal forest of Western Canada to the interior Atlantic forest of Paraguay we show how transparent and defensible methods for scenario analysis can be applied in data-limited regions and how social dimensions of land use change can be incorporated in these methods, particularly in aboriginal communities that have lived in these ecosystems for generations. The case studies explore how scenario analysis can be used to evaluate various land use options and highlight specific challenges with identifying social and ecological responses, determining thresholds and targets for land use, and integrating local and traditional knowledge in land use planning. Given that land use planning is ultimately a value-laden and often politically charged process we also provide some perspective on various collective and expert-based processes for identifying cumulative impacts and thresholds. The need for good science to inform and be informed by culturally appropriate democratic processes calls for well-planned and multifaceted approaches both to achieve an informed understanding of both residents and governments of the interactive and additive changes caused by development, and to design action agendas to influence such change at the ecological and social level.

  17. The ecological atlas. 3. rev. ed.

    International Nuclear Information System (INIS)

    Seager, J.

    1993-01-01

    ''The ecological atlas'' translates expert knowledge in a way that makes it accessable to the general public. In 37 double sided maps in four colours it gives information about the health of our planet and the quality of human life. Under 8 different angles: (the earth's habitat, food and drinking water, housing, energy, industry, armament, consumer needs and 'green politics'). ''The ecological atlas'' describes the effects of worldwide ecological effects: climatic disasters, the greenhouse effect, the hole in the ozone layer, destruction of the tropical rainforests, the effects of extensive farming and increasing urbanization. Pages of comprehensive commentaries complement the maps and aid understanding of their problem areas. (orig./DG) [de

  18. Bactericidal Activity of Ceragenin CSA-13 in Cell Culture and in an Animal Model of Peritoneal Infection.

    Science.gov (United States)

    Bucki, Robert; Niemirowicz, Katarzyna; Wnorowska, Urszula; Byfield, Fitzroy J; Piktel, Ewelina; Wątek, Marzena; Janmey, Paul A; Savage, Paul B

    2015-10-01

    Ceragenins constitute a novel family of cationic antibiotics characterized by a broad spectrum of antimicrobial activities, which have mostly been assessed in vitro. Using a polarized human lung epithelial cell culture system, we evaluated the antibacterial activities of the ceragenin CSA-13 against two strains of Pseudomonas aeruginosa (PAO1 and Xen5). Additionally, the biodistribution and bactericidal activity of a CSA-13-IRDye 800CW derivate were assessed using an animal model of peritoneal infection after PAO1 challenge. In cell culture, CSA-13 bactericidal activities against PAO1 and Xen5 were higher than the activities of the human cathelicidin peptide LL-37. Increased CSA-13 activity was observed in polarized human lung epithelial cell cultures subjected to butyric acid treatment, which is known to increase endogenous LL-37 production. Eight hours after intravenous or intraperitoneal injection, the greatest CSA-13-IRDye 800CW accumulation was observed in mouse liver and kidneys. CSA-13-IRDye 800CW administration resulted in decreased bacterial outgrowth from abdominal fluid collected from animals subjected to intraperitoneal PAO1 infection. These observations indicate that CSA-13 may synergistically interact with antibacterial factors that are naturally present at mucosal surfaces and it maintains its antibacterial activity in the infected abdominal cavity. Cationic lipids such as CSA-13 represent excellent candidates for the development of new antibacterial compounds. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  19. Clinical effect of a dentifrice containing three kinds of bactericidal ingredients on periodontal disease: a pilot study in patients undergoing supportive periodontal therapy.

    Science.gov (United States)

    Kita, Daichi; Kinumatsu, Takashi; Yokomizo, Atsushi; Tanaka, Miki; Egawa, Masahiro; Makino-Oi, Asako; Tomita, Sachiyo; Saito, Atsushi

    2018-02-09

    This study aimed to evaluate clinically the effect of a novel dentifrice containing three kinds of bactericidal ingredients on periodontal disease. This was a single-arm, prospective clinical study that enrolled patients with periodontitis undergoing supportive periodontal therapy. Periodontal examination, microbiological testing of saliva samples, and evaluation of inflammatory markers (IL-1β, IL-6, IL-8, TNF-α) in gingival crevicular fluid were performed. After 4 weeks of the use of test dentifrice, these parameters were re-evaluated. The use of dentifrice was also subjectively evaluated by clinicians and participants. Among 30 participants, there were significant improvements in the periodontal and microbiological parameters, and the level of interleukin-1β in the gingival crevicular fluid, following the use of the test dentifrice. In clinicians' subjective evaluation of the overall usefulness of the dentifrice, 'mild' and 'moderate' improvement accounted for 83% of the total responses. In the participants' subjective evaluation, the majority indicated their experience of the use as favorable. Within the limitations of this study, it is suggested that the progression of periodontal disease during the supportive periodontal therapy can be prevented by the use of the test dentifrice. Trial registration UMIN Clinical Trials Registry (UMIN-CTR) 000023175. Date of formal registration: July 14, 2016 ( https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000026716 ).

  20. Development of Titanium Dioxide (TiO2 ) Nanocoatings on Food Contact Surfaces and Method to Evaluate Their Durability and Photocatalytic Bactericidal Property.

    Science.gov (United States)

    Yemmireddy, Veerachandra K; Farrell, Glenn D; Hung, Yen-Con

    2015-08-01

    Titanium dioxide (TiO2 ) is a well-known photocatalyst for its excellent bactericidal property under UVA light. The purpose of this study was to develop physically stable TiO2 coatings on food contact surfaces using different binding agents and develop methods to evaluate their durability and microbicidal property. Several types of organic and inorganic binders such as polyvinyl alcohol, polyethylene glycol, polyurethane, polycrylic, sodium and potassium silicates, shellac resin, and other commercial binders were used at 1:1 to 1:16 nanoparticle to binder weight ratios to develop a formulation for TiO2 coating on stainless steel surfaces. Among the tested binders, polyurethane, polycrylic, and shellac resin were found to be physically more stable when used in TiO2 coating at 1:4 to 1:16 weight ratio. The physical stability of TiO2 coatings was determined using adhesion strength and scratch hardness tests by following standard ASTM procedures. Further, wear resistance of the coatings was evaluated based on a simulated cleaning procedure used in food processing environments. TiO2 coating with polyurethane at a 1:8 nanoparticle to binder weight ratio showed the highest scratch hardness (1.08 GPa) followed by coating with polycrylic (0.68 GPa) and shellac (0.14 GPa) binders. Three different techniques, namely direct spreading, glass cover-slip, and indented coupon were compared to determine the photocatalytic bactericidal property of TiO2 coatings against Escherichia coli 0157:H7 at 2 mW/cm(2) UVA light intensity. Under the tested conditions, the indented coupon technique was found to be the most appropriate method to determine the bactericidal property of TiO2 coatings and showed a reduction of 3.5 log CFU/cm(2) in 2 h. © 2015 Institute of Food Technologists®

  1. Ecological effects research related to oil spills and oil spill countermeasures

    International Nuclear Information System (INIS)

    Aurand, D.

    1992-01-01

    The Marine Spill Response Corporation (MSRC) was created specifically to provide an improved response option for large marine oil spills in U.S. waters. As part of that capability, MSRC is committed to an extensive research and development program designed to improve the state-of-the-art for oil spill response. Within the mission, the goals of the Environmental Health Program are to ensure that ecological and human health effects of both oil and oil cleanup counter measures are well understood and that this information is made widely available for appropriate consideration in planning and implementing oil spill response efforts. This an applied program, and is intended to directly support the MSRC response mission. It does not include studies directly related to damage assessment, which is outside of the mission of MSRC. This paper focuses on the issues MSRC sees as critical in the area of ecological effects research, and addresses four topics: Why do we need to do more? What is it we hope to accomplish? What needs to be done? What is being planned or implemented?

  2. Antimicrobial effect of essential oil of Citrus reticulata on Fusobacterium nucleatum associated with periodontal disease

    Directory of Open Access Journals (Sweden)

    Cindy Giohanna Pardo

    2017-07-01

    Full Text Available Chlorhexidine as a treatment of periodontal disease has achieved bactericidal effects over periodontopathogens and oral biofilm. Its use generates adverse effects; therefore natural alternatives are presented with a similar antimicrobial effect. Essential oils have proved effective in controlling dental plaque without the adverse effects of chlorhexidine. The aim of this study was to determine the bacteriostatic and bactericidal effect of essential oil of tangerine against Fusobacterium nucleatum. The extraction of the essential oil was performed by expression of tangerine peels (Arrayana and Oneco varieties. Concentrations at 20%, 40%, 60%, 80% and 100% of the essential oil diluted in 0,02% Tween were evaluated. The bacteriostatic and bactericidal effect was determined by antimicrobial susceptibility testing by disk diffusion. As a positive control 0,2% chlorhexidine and water as negative control were used. Inhibition zone (mm was measured and presence or absence of bacterial growth was determined from colony forming units.  To compare proportions of bacteriostatic and bactericidal activity, Fisher and T student test (95% CI p = 0,05 were performed. The 100% concentration zone of inhibition showed a similar behavior as chlorhexidine (p 0,05. The use of essential oils of tangerine could be a complementary alternative to treatment of periodontal disease.

  3. Ecological impact assessment

    International Nuclear Information System (INIS)

    Thomas, J.M.; Eberhardt, L.L.

    1975-01-01

    Quantitative problems in accomplishing ecological impact assessment with particular reference to defining population effects are discussed with some comments on the two approaches most commonly used, e.g., the experimental and simulation models. Some alternatives are suggested because both methods will probably fail to detect real population effects mostly due to poor understanding of ecosystems or because of the limitations inherent in field census methods. Most judgments of ecological impact are not quantitatively defensible but are qualitative, subjective, or political in nature. An examination of aggregates of data from various nuclear power plant sites may be one way to obtain enough replication to judge ecological impact. Thus, currently available data from such studies as well as appropriate demographic, vegetation, census, and bibliographic material could offer an interesting challenge to computer professionals if such an undertaking were contemplated. Present research programs at PNL and computer involvement are described. Future possibilities and directions are discussed. (U.S.)

  4. Pitfalls in ecological research - transgenerational effects

    Czech Academy of Sciences Publication Activity Database

    Latzel, Vít

    2015-01-01

    Roč. 50, č. 1 (2015), s. 75-85 ISSN 1211-9520 R&D Projects: GA ČR(CZ) GA14-06802S Institutional support: RVO:67985939 Keywords : ecology * epigenetics * evolution Subject RIV: EF - Botanics Impact factor: 1.433, year: 2015

  5. Clemastine as Antimicrobial Agent: Effectiveness and Mechanism of Action

    Directory of Open Access Journals (Sweden)

    S.Fazli Bazaz

    1991-07-01

    Full Text Available In this investigation, the antimicrobial activity of Clemastine was studied.The Minimum Inhibitory Concentrations (MICs of this drug against some bacteria were determined using tube dilution method.To find out the bactericidal activity of Clemastine, the number of living bacteria in the presence of drug was counted by a culture method (pour plate method. Thereafter, the preservative effectiveness of Clemastine was studied in detail using standard method (USP 1985.The results show a good antibacterial but not antifungal activity."nIn considering the mechanism of action of Clemastine, it can be seen that the drug has some effect on cell membrane permeability and causes leakage of intracellular material including the K+ .Comparing the bactericidal results with the leakage of K+, shows that the leakage may be due to the bactericidal activity of the drug.

  6. Analysis of ecological effects of geopressured-geothermal resource development. Geopressured-geothermal technical paper No. 4

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    The activities involved in geopressured-geothermal resource production are identified and their ecological impacts are discussed. The analysis separates those activites that are unique to geopressured-geothermal development from those that also occur in oil and gas and other resource developments. Of the unique activities, those with the greatest potential for serious ecological effect are: (1) accidental brine discharge as a result of a blowout during well drilling; (2) subsidence; (3) fault activation and enhanced seismicity; and (4) subsurface contamination of water, hydrocarbon, and mineral reservoirs. Available methods to predict and control these effects are discussed.

  7. CROSERF: Toward a standardization of oil spill cleanup agent ecological effects research

    International Nuclear Information System (INIS)

    Singer, M.; Tjeerdema, R.; Aurand, D.; Clark, J.; Sergy, G.

    1995-01-01

    The establishment in 1994 of the Chemical Response to Oil Spills Ecological Effects Research Forum (CROSERF) for the development of standardization of protocols used in ecological research of oil spills and remediation efforts was described. Background and the need for such an organization was discussed. Discussions at the two meetings of the forum to date (generation of scientific data for decision making in August 1994 at the University of California at Santa Cruz, and toxicity testing of the water-accommodated fraction of the oil in March 1995 at the Louisiana Oil Spill Coordinator's Office in Baton Rouge) were summarized. A list of the organizations represented at the meetings was given. 5 refs

  8. Preparation and bactericide activity of gallic acid stabilized gold nanoparticles

    International Nuclear Information System (INIS)

    Moreno-Alvarez, S. A.; Martinez-Castanon, G. A.; Nino-Martinez, N.; Reyes-Macias, J. F.; Patino-Marin, N.; Loyola-Rodriguez, J. P.; Ruiz, Facundo

    2010-01-01

    In this work, gold nanoparticles with three different sizes (13.7, 39.4, and 76.7 nm) were prepared using a simple aqueous method with gallic acid as the reducing and stabilizing agent, the different sizes were obtained varying some experimental parameters as the pH of the reaction and the amount of the gallic acid. The prepared nanoparticles were characterized using X-ray diffraction, transmission electron microscopy, dynamic light scattering, and UV-Vis spectroscopy. Samples were identified as elemental gold and present spherical morphology, a narrow size distribution and good stabilization according to TEM and DLS results. The antibacterial activity of this gallic acid stabilized gold nanoparticles against S. mutans (the etiologic agent of dental caries) was assessed using a microdilution method obtaining a minimum inhibitory concentration of 12.31, 12.31, and 49.25 μg/mL for 13.7, 39.4, and 76.7 nm gold nanoparticles, respectively. The antibacterial assay showed that gold nanoparticles prepared in this work present a bactericide activity by a synergistic action with gallic acid. The MIC found for this nanoparticles are much lower than those reported for mixtures of gold nanoparticles and antibiotics.

  9. Preparation and bactericide activity of gallic acid stabilized gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Alvarez, S. A. [UASLP, Doctorado Institucional en Ingenieria y Ciencia de Materiales (Mexico); Martinez-Castanon, G. A., E-mail: mtzcastanon@fciencias.uaslp.m [UASLP, Maestria en Ciencias Odontologicas, Facultad de Estomatologia (Mexico); Nino-Martinez, N. [UASLP, Facultad de Ciencias (Mexico); Reyes-Macias, J. F.; Patino-Marin, N.; Loyola-Rodriguez, J. P. [UASLP, Maestria en Ciencias Odontologicas, Facultad de Estomatologia (Mexico); Ruiz, Facundo [UASLP, Facultad de Ciencias (Mexico)

    2010-10-15

    In this work, gold nanoparticles with three different sizes (13.7, 39.4, and 76.7 nm) were prepared using a simple aqueous method with gallic acid as the reducing and stabilizing agent, the different sizes were obtained varying some experimental parameters as the pH of the reaction and the amount of the gallic acid. The prepared nanoparticles were characterized using X-ray diffraction, transmission electron microscopy, dynamic light scattering, and UV-Vis spectroscopy. Samples were identified as elemental gold and present spherical morphology, a narrow size distribution and good stabilization according to TEM and DLS results. The antibacterial activity of this gallic acid stabilized gold nanoparticles against S. mutans (the etiologic agent of dental caries) was assessed using a microdilution method obtaining a minimum inhibitory concentration of 12.31, 12.31, and 49.25 {mu}g/mL for 13.7, 39.4, and 76.7 nm gold nanoparticles, respectively. The antibacterial assay showed that gold nanoparticles prepared in this work present a bactericide activity by a synergistic action with gallic acid. The MIC found for this nanoparticles are much lower than those reported for mixtures of gold nanoparticles and antibiotics.

  10. The effect of polyhexamethylene guanidine hydrochloride (PHMG) derivatives introduced into polylactide (PLA) on the activity of bacterial enzymes.

    Science.gov (United States)

    Walczak, Maciej; Richert, Agnieszka; Burkowska-But, Aleksandra

    2014-11-01

    The present study was aimed at investigating bactericidal properties of polylactide (PLA) films containing three different polyhexamethylene guanidine hydrochloride (PHMG) derivatives and effect of the derivatives on extracellular hydrolytic enzymes and intracellular dehydrogenases. All PHMG derivatives had a slightly stronger bactericidal effect on Staphylococcus aureus than on E. coli but only PHMG granular polyethylene wax (at the concentration of at least 0.6 %) has a bactericidal effect. PHMG derivatives introduced into PLA affected the activity of microbial hydrolases to a small extent. This means that the introduction of PHMG derivatives into PLA will not reduce its enzymatic biodegradation significantly. On the other hand, PHMG derivatives introduced into PLA strongly affected dehydrogenases activity in S. aureus than in E. coli.

  11. Effect of Oxygen Limitation and Starvation on the Benzalkonium Chloride Susceptibility of Escherichia coli

    DEFF Research Database (Denmark)

    Bjergbæk, L.A.; Haagensen, Janus Anders Juul; Molin, Søren

    2008-01-01

    the gfp-tagged E. coli K-12 strain MG1655[pOX38Km]. Increasing temperature from 10 degrees C to 30 degrees C increased the bactericidal effect of BAC for both starved and nonstarved E. coli under aerobic and anaerobic conditions. The lowest minimum bactericidal concentration was observed for cells...

  12. Increasing connectivity between metapopulation ecology and landscape ecology.

    Science.gov (United States)

    Howell, Paige E; Muths, Erin; Hossack, Blake R; Sigafus, Brent H; Chandler, Richard B

    2018-05-01

    Metapopulation ecology and landscape ecology aim to understand how spatial structure influences ecological processes, yet these disciplines address the problem using fundamentally different modeling approaches. Metapopulation models describe how the spatial distribution of patches affects colonization and extinction, but often do not account for the heterogeneity in the landscape between patches. Models in landscape ecology use detailed descriptions of landscape structure, but often without considering colonization and extinction dynamics. We present a novel spatially explicit modeling framework for narrowing the divide between these disciplines to advance understanding of the effects of landscape structure on metapopulation dynamics. Unlike previous efforts, this framework allows for statistical inference on landscape resistance to colonization using empirical data. We demonstrate the approach using 11 yr of data on a threatened amphibian in a desert ecosystem. Occupancy data for Lithobates chiricahuensis (Chiricahua leopard frog) were collected on the Buenos Aires National Wildlife Refuge (BANWR), Arizona, USA from 2007 to 2017 following a reintroduction in 2003. Results indicated that colonization dynamics were influenced by both patch characteristics and landscape structure. Landscape resistance increased with increasing elevation and distance to the nearest streambed. Colonization rate was also influenced by patch quality, with semi-permanent and permanent ponds contributing substantially more to the colonization of neighboring ponds relative to intermittent ponds. Ponds that only hold water intermittently also had the highest extinction rate. Our modeling framework can be widely applied to understand metapopulation dynamics in complex landscapes, particularly in systems in which the environment between habitat patches influences the colonization process. © 2018 by the Ecological Society of America.

  13. [On the bactericidal action of dibromoisocyanuric acid; experiments concerning the disinfection of hands (author's transl)].

    Science.gov (United States)

    Gottardi, W; Puritscher, M

    1976-07-01

    The action of dibromoisocyanuric acid (DBI), C12, Br2, trichloroisocyanuric acid (TCI) and chloramine T against Staph. aureus SG 511 was compared. Using the suspension test DBI and Br2 showed the strongest, chloramine T however, the weakest bactericidal power (Tab 2). Under the conditions of the "Hygienic disinfection of hands" a 0.005 M solution of DBI met the requirements specified in the "Richtlinien für die Prüfung chemischer Desinfektionsmittel" (3. Ed., Stuttgart: Gustav Fischer Verlag, 1972), and was comparable to a chloramine T solution containing the same amount of active halogen (Tab. 3). The decrease of disinfection power compared with the suspension test can be attributed to a great error induced by protein.

  14. Marine Ecological Environment Management Based on Ecological Compensation Mechanisms

    Directory of Open Access Journals (Sweden)

    Qunzhen Qu

    2016-12-01

    Full Text Available The level of marine environmental management is a key factor in the successful implementation of marine power strategies. The improvement in management levels of marine environments requires innovation in marine management. In other words, the transformation of marine environmental management into marine ecological environment management must be done in order to achieve sustainable development of the marine economy. As an environmental economic policy that combines both administrative and market measures, ecological compensation mechanisms have significant advantages in marine ecological environment management. Based on the study of the current development of ecological compensation mechanisms in China, through the analysis of the connotation of marine ecological civilization, existing marine ecological protection practices and marine environmental management methods, this paper posits that the current marine ecological environment management in China should be established on the basis of ecological compensation mechanisms. At present, a lack of laws and regulations for overall marine ecological environment management is the key factor restricting the practice of marine ecological environment management. Therefore, it is necessary to explore the current path of marine ecological environment management in China from the perspective of the construction of legal system of ecological compensation law, the establishment of ecological compensation fees, ecological taxes and ecological compensation fund systems, and the clear status for a marine ecological management and supervision body.

  15. Beyond positivist ecology: toward an integrated ecological ethics.

    Science.gov (United States)

    Norton, Bryan G

    2008-12-01

    A post-positivist understanding of ecological science and the call for an "ecological ethic" indicate the need for a radically new approach to evaluating environmental change. The positivist view of science cannot capture the essence of environmental sciences because the recent work of "reflexive" ecological modelers shows that this requires a reconceptualization of the way in which values and ecological models interact in scientific process. Reflexive modelers are ecological modelers who believe it is appropriate for ecologists to examine the motives for their choices in developing models; this self-reflexive approach opens the door to a new way of integrating values into public discourse and to a more comprehensive approach to evaluating ecological change. This reflexive building of ecological models is introduced through the transformative simile of Aldo Leopold, which shows that learning to "think like a mountain" involves a shift in both ecological modeling and in values and responsibility. An adequate, interdisciplinary approach to ecological valuation, requires a re-framing of the evaluation questions in entirely new ways, i.e., a review of the current status of interdisciplinary value theory with respect to ecological values reveals that neither of the widely accepted theories of environmental value-neither economic utilitarianism nor intrinsic value theory (environmental ethics)-provides a foundation for an ecologically sensitive evaluation process. Thus, a new, ecologically sensitive, and more comprehensive approach to evaluating ecological change would include an examination of the metaphors that motivate the models used to describe environmental change.

  16. [Regional ecological construction and mission of landscape ecology].

    Science.gov (United States)

    Xiao, Duning; Xie, Fuju; Wei, Jianbing

    2004-10-01

    The eco-construction on regional and landscape scale is the one which can be used to specific landscape and intercrossing ecosystem in specific region including performing scientific administration of ecosystem and optimizing environmental function. Recently, the government has taken a series of significant projects into action, such as national forest protection item, partly forest restoration, and adjustment of water, etc. Enforcing regional eco-construction and maintaining the ecology security of the nation have become the strategic requisition. In various regions, different eco-construction should be applied, for example, performing ecological safeguard measure in ecological sensitive zone, accommodating the ecological load in ecological fragile zone, etc., which can control the activities of human being, so that, sustainable development can be reached. Facing opportunity and challenge in the development of landscape ecology, we have some key topics: landscape pattern of ecological security, land use and ecological process, landscape changes under human activity stress, quantitative evaluation of the influence on human being activities, evaluation of zonal ecological security and advance warning of ecological risk, and planning and optimizing of model in landscape eco-construction.

  17. Trends and driving forces of ecological training and education in the context of ecological education environment of the technical university

    OpenAIRE

    Danilenkova V. A.

    2017-01-01

    common patterns of ecological training and education in the technical university are analyzed in this article, their descriptions are defined. Driving forces of ecological training and education in the context of ecological education environment are discovered and proved. According to conducted research the author makes a proposition to point out at ecological risks as driving forces, searching for which improves the efficiency and effectiveness of ecological education environment. The resear...

  18. Introducing Meta-Partition, a Useful Methodology to Explore Factors That Influence Ecological Effect Sizes.

    Directory of Open Access Journals (Sweden)

    Zaida Ortega

    Full Text Available The study of the heterogeneity of effect sizes is a key aspect of ecological meta-analyses. Here we propose a meta-analytic methodology to study the influence of moderators in effect sizes by splitting heterogeneity: meta-partition. To introduce this methodology, we performed a meta-partition of published data about the traits that influence species sensitivity to habitat loss, that have been previously analyzed through meta-regression. Thus, here we aim to introduce meta-partition and to make an initial comparison with meta-regression. Meta-partition algorithm consists of three steps. Step 1 is to study the heterogeneity of effect sizes under the assumption of fixed effect model. If heterogeneity is found, we perform step 2, that is, to partition the heterogeneity by the moderator that minimizes heterogeneity within a subset while maximizing heterogeneity between subsets. Then, if effect sizes of the subset are still heterogeneous, we repeat step 1 and 2 until we reach final subsets. Finally, step 3 is to integrate effect sizes of final subsets, with fixed effect model if there is homogeneity, and with random effects model if there is heterogeneity. Results show that meta-partition is valuable to assess the importance of moderators in explaining heterogeneity of effect sizes, as well as to assess the directions of these relations and to detect possible interactions between moderators. With meta-partition we have been able to evaluate the importance of moderators in a more objective way than with meta-regression, and to visualize the complex relations that may exist between them. As ecological issues are often influenced by several factors interacting in complex ways, ranking the importance of possible moderators and detecting possible interactions would make meta-partition a useful exploration tool for ecological meta-analyses.

  19. The raison d'être of chemical ecology.

    Science.gov (United States)

    Raguso, Robert A; Agrawal, Anurag A; Douglas, Angela E; Jander, Georg; Kessler, André; Poveda, Katja; Thaler, Jennifer S

    2015-03-01

    Chemical ecology is a mechanistic approach to understanding the causes and consequences of species interactions, distribution, abundance, and diversity. The promise of chemical ecology stems from its potential to provide causal mechanisms that further our understanding of ecological interactions and allow us to more effectively manipulate managed systems. Founded on the notion that all organisms use endogenous hormones and chemical compounds that mediate interactions, chemical ecology has flourished over the past 50 years since its origin. In this essay we highlight the breadth of chemical ecology, from its historical focus on pheromonal communication, plant-insect interactions, and coevolution to frontier themes including community and ecosystem effects of chemically mediated species interactions. Emerging approaches including the -omics, phylogenetic ecology, the form and function of microbiomes, and network analysis, as well as emerging challenges (e.g., sustainable agriculture and public health) are guiding current growth of this field. Nonetheless, the directions and approaches we advocate for the future are grounded in classic ecological theories and hypotheses that continue to motivate our broader discipline.

  20. Landscape Sources, Ecological Effects, and Management of Nutrients in Lakes of Northeastern USA

    Science.gov (United States)

    Lakes face escalating pressures associated with land cover change and growing human populations. Ecological responses provide context for identifying stressor severity, land use impacts, and management effectiveness. We used EPA National Lakes Assessment data and GIS to develop i...

  1. Functional group, biomass, and climate change effects on ecological drought in semiarid grasslands

    Science.gov (United States)

    Wilson, Scott D.; Schlaepfer, Daniel R.; Bradford, John B.; Lauenroth, William K.; Duniway, Michael C.; Hall, Sonia A.; Jamiyansharav, Khishigbayar; Jia, Gensuo; Lkhagva, Ariuntsetseg; Munson, Seth M.; Pyke, David A.; Tietjen, Britta

    2018-01-01

    Water relations in plant communities are influenced both by contrasting functional groups (grasses, shrubs) and by climate change via complex effects on interception, uptake and transpiration. We modelled the effects of functional group replacement and biomass increase, both of which can be outcomes of invasion and vegetation management, and climate change on ecological drought (soil water potential below which photosynthesis stops) in 340 semiarid grassland sites over 30‐year periods. Relative to control vegetation (climate and site‐determined mixes of functional groups), the frequency and duration of drought were increased by shrubs and decreased by annual grasses. The rankings of shrubs, control vegetation, and annual grasses in terms of drought effects were generally consistent in current and future climates, suggesting that current differences among functional groups on drought effects predict future differences. Climate change accompanied by experimentally‐increased biomass (i.e. the effects of invasions that increase community biomass, or management that increases productivity through fertilization or respite from grazing) increased drought frequency and duration, and advanced drought onset. Our results suggest that the replacement of perennial temperate semiarid grasslands by shrubs, or increased biomass, can increase ecological drought both in current and future climates.

  2. Social Interface Model: Theorizing Ecological Post-Delivery Processes for Intervention Effects.

    Science.gov (United States)

    Pettigrew, Jonathan; Segrott, Jeremy; Ray, Colter D; Littlecott, Hannah

    2018-01-03

    Successful prevention programs depend on a complex interplay among aspects of the intervention, the participant, the specific intervention setting, and the broader set of contexts with which a participant interacts. There is a need to theorize what happens as participants bring intervention ideas and behaviors into other life-contexts, and theory has not yet specified how social interactions about interventions may influence outcomes. To address this gap, we use an ecological perspective to develop the social interface model. This paper presents the key components of the model and its potential to aid the design and implementation of prevention interventions. The model is predicated on the idea that intervention message effectiveness depends not only on message aspects but also on the participants' adoption and adaptation of the message vis-à-vis their social ecology. The model depicts processes by which intervention messages are received and enacted by participants through social processes occurring within and between relevant microsystems. Mesosystem interfaces (negligible interface, transference, co-dependence, and interdependence) can facilitate or detract from intervention effects. The social interface model advances prevention science by theorizing that practitioners can create better quality interventions by planning for what occurs after interventions are delivered.

  3. Ecological alarm system for Itaipu

    Energy Technology Data Exchange (ETDEWEB)

    Faehser, L.

    1984-05-01

    At Itaipu, on the Rio Parana, Brazil and Paraguay are constructing the world's largest hydro-electric power plant with a capacity seven times as high as that of Assuan. An information system is intended to give fair warning in case of threatening ecological conditions. The computer-supported alarm system had four objectives: 1. presentation of the present ecological situation; 2. evaluation of the ecological risks; 3. warning about ecological deficits; 4. suggestions for establishing ecological stability. In a first step the available inventory data concerning soil, topography, vegetation and water were evaluated by expert groups according to their risk grade (0-4) and ecological weight (1-10). The product of these evaluations indicates the ecological deficit (0-40). At a threshold value of 30, the information system automatically signals ecological alarm and locates the centre of danger via computer-plotted maps and tables. The necessary data are supplied periodically by selected measurement stations. Quantification of ecological facts enables the persons who are responsible for decisions at Itaipu to recognize, avoid, or diminish elements of danger even if they have little or no ecological knowledge. The file of data that has been compiled so far should be extended parallel with the development in the Itaipu area. With the help of factor analysis connections of cause and effect can be detected in this extremely complex reservoir system which has hardly been explored yet.

  4. The Effects of Poverty on Children's Socioemotional Development: An Ecological Systems Analysis.

    Science.gov (United States)

    Eamon, Mary Keegan

    2001-01-01

    Bronfenbrenner's process-person-context-time model is used to examine theories that explain adverse effects of economic deprivation on children's socioemotional development. Processes of not only the family, but also those of the peer group and school, and in other levels of the ecological environment may also explain the relation between economic…

  5. Effects of salinity and water temperature on the ecological performance of Zostera marina

    DEFF Research Database (Denmark)

    Nejrup, Lars Brammer; Pedersen, Morten Foldager

    2008-01-01

    We tested the effects of salinity and water temperature on the ecological performance of eelgrass (Zostera marina L.) in culture-experiments to identify levels that could potentially limit survival and growth and, thus, the spatial distribution of eelgrass in temperate estuaries. The experiments ...

  6. Using latent effects to determine the ecological importance of dissolved organic matter to marine invertebrates.

    Science.gov (United States)

    Wendt, Dean E; Johnson, Collin H

    2006-10-01

    The uptake and utilization of dissolved organic matter (DOM) by marine invertebrates is a field that has received significant attention over the past 100 years. Although it is well established that DOM is taken up by marine invertebrates, the extent to which it contributes to an animal's survival, growth, and reproduction (that is, the ecological benefits) remains largely unknown. Previous work seeking to demonstrate the putative ecological benefits of DOM uptake have examined them within a single life stage of an animal. Moreover, most of the benefits are demonstrated through indirect approaches by examining (1) mass balance, or (2) making comparisons of oxyenthalpic conversions of transport rates to metabolic rate as judged by oxygen consumption. We suggest that directly examining delayed metamorphosis or the latent effects associated with nutritional stress of larvae is a better model for investigating the ecological importance of DOM to marine invertebrates. We also provide direct evidence that availability of DOM enhances survival and growth of the bryozoan Bugula neritina. That DOM offsets latent effects in B. neritina suggests that the underlying mechanisms are at least in part energetic.

  7. Production of TiO2 films with bactericidal properties deposited on paper substrate

    Energy Technology Data Exchange (ETDEWEB)

    Lisboa, A.J.T.; Vasconcelos, J.S.; Vasconcelos, A.C.S.; Vasconcelos, N.S.L.S.; Rangel, J.H.G.; Oliveira, M.M.O. [Universidade Federal do Maranha (UFMA), MA (Brazil); Longo, E.; Varela, J. A. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), SP (Brazil)

    2014-07-01

    The main objective of this work was to obtain anatase-phase titanium oxide films deposited on paper substrates, using the polymeric precursor (Pechini) method. The oxide was mixed with a polyvinyl alcohol (PVA) solution and deposited on a paper substrate. The samples were then characterized by X-ray diffraction (XRD), field emission gun scanning electron microscopy (FEG-SEM), and energy dispersive spectroscopy (EDS), to check their surface phase. Bactericidal assays using Staphylococcus aureus and Escherichia coli bacteria for the anatase TiO2 film deposited on paper substrate indicated that the method was efficient, since the bacteria were eliminated after a given exposure time. However, the method proved to be more efficient when exposing samples contaminated with E. coli to UV irradiation for 30 and 45 min and then to sunlight for 90 min, since this resulted in the elimination of all the bacteria. (author)

  8. Production of TiO2 films with bactericidal properties deposited on paper substrate

    International Nuclear Information System (INIS)

    Lisboa, A.J.T.; Vasconcelos, J.S.; Vasconcelos, A.C.S.; Vasconcelos, N.S.L.S.; Rangel, J.H.G.; Oliveira, M.M.O.; Longo, E.; Varela, J. A.

    2014-01-01

    The main objective of this work was to obtain anatase-phase titanium oxide films deposited on paper substrates, using the polymeric precursor (Pechini) method. The oxide was mixed with a polyvinyl alcohol (PVA) solution and deposited on a paper substrate. The samples were then characterized by X-ray diffraction (XRD), field emission gun scanning electron microscopy (FEG-SEM), and energy dispersive spectroscopy (EDS), to check their surface phase. Bactericidal assays using Staphylococcus aureus and Escherichia coli bacteria for the anatase TiO2 film deposited on paper substrate indicated that the method was efficient, since the bacteria were eliminated after a given exposure time. However, the method proved to be more efficient when exposing samples contaminated with E. coli to UV irradiation for 30 and 45 min and then to sunlight for 90 min, since this resulted in the elimination of all the bacteria. (author)

  9. Theoretically exploring direct and indirect chemical effects across ecological and exposure scenarios using mechanistic fate and effects modelling

    NARCIS (Netherlands)

    Laender, de F.; Morselli, M.; Baveco, H.; Brink, van den P.J.; Guardo, Di A.

    2015-01-01

    Predicting ecosystem response to chemicals is a complex problem in ecotoxicology and a challenge for risk assessors. The variables potentially influencing chemical fate and exposure define the exposure scenario while the variables determining effects at the ecosystem level define the ecological

  10. [Progress and prospects on evaluation of ecological restoration: a review of the 5th World Conference on Ecological Restoration].

    Science.gov (United States)

    Ding, Jing-Yi; Zhao, Wen-Wu

    2014-09-01

    The 5th World Conference on Ecological Restoration was held in Madison, Wisconsin, USA on October 6-11, 2013. About 1200 delegates from more than 50 countries attended the conference, and discussed the latest developments in different thematic areas of ecological restoration. Discussions on evaluation of ecological restoration were mainly from three aspects: The construction for evaluation indicator system of ecological restoration; the evaluation methods of ecological restoration; monitoring and dynamic evaluation of ecological restoration. The meeting stressed the importance of evaluation in the process of ecological restoration and concerned the challenges in evaluation of ecological restoration. The conference had the following enlightenments for China' s research on evaluation of ecological restoration: 1) Strengthening the construction of comprehensive evaluation indicators system and focusing on the multi-participation in the evaluation process. 2) Paying more attentions on scale effect and scale transformation in the evaluation process of ecological restoration. 3) Expanding the application of 3S technology in assessing the success of ecological restoration and promoting the dynamic monitoring of ecological restoration. 4) Carrying out international exchanges and cooperation actively, and promoting China's international influence in ecological restoration research.

  11. Aerobic Granular Sludge: Effect of Salt and Insights into Microbial Ecology

    KAUST Repository

    Wang, Zhongwei

    2017-12-01

    Aerobic granular sludge (AGS) technology is a next-generation technology for the biological treatment of wastewater. The advantages of AGS in terms of small footprint, low operation and capital cost and high effluent quality makes it a strong candidate for replacing conventional biological wastewater treatment based on activated sludge (CAS) process, and potentially become the standard for biological wastewater treatment in the future. Saline wastewater is generated from many industrial processes as well as from the use of sea water as a secondary quality water for non-potable use such as toilet flushing to mitigate shortage of fresh water in some coastal cities. Salt is known to inhibit biological wastewater treatment processes in terms of organic and nutrient removal. In the first part of my dissertation, I conducted three lab-scale experiments to 1) evaluate the effect of salt on granulation and nutrient removal in AGS (330 days); 2) develop engineering strategies to mitigate the adverse effect of salt on nutrient removal of AGS (164 days); and 3) compare the effect of salt on the stoichiometry and kinetics of different phosphate accumulating organisms (PAO) clades (PAOI and PAOII) and to determine the effect of potassium and sodium ions on the activities of different PAO clades (225 days). Like other artificial microbial ecosystems (e.g. CAS plant and anaerobic digester), a firm understanding of the microbial ecology of AGS system is essential for process design and optimization. The second part of my dissertation reported the first microbial ecology study of a full-scale AGS plant with the aim of addressing the role of regional (i.e. immigration) versus local factors in shaping the microbial community assembly of different-sized microbial aggregates in AGS. The microbial communities in a full-scale AGS plant in Garmerwolde, The Netherlands, was characterized periodically over 180 days using Illumina sequencing of 16S ribosomal RNA amplicons of the V3-V4

  12. Non-linear effects of drought under shade: reconciling physiological and ecological models in plant communities

    NARCIS (Netherlands)

    Holmgren, M.; Gomez-Aparicio, L.; Quero, J.L.; Valladares, F.

    2012-01-01

    The combined effects of shade and drought on plant performance and the implications for species interactions are highly debated in plant ecology. Empirical evidence for positive and negative effects of shade on the performance of plants under dry conditions supports two contrasting theoretical

  13. A review of fire effects on vegetation and soils in the Great Basin region: response and ecological site characteristics

    Science.gov (United States)

    Miller, Richard F.; Chambers, Jeanne C.; Pyke, David A.; Pierson, Fred B.; Williams, C. Jason

    2013-01-01

    This review synthesizes the state of knowledge on fire effects on vegetation and soils in semi-arid ecosystems in the Great Basin Region, including the central and northern Great Basin and Range, Columbia River Basin, and the Snake River Plain. We summarize available literature related to: (1) the effects of environmental gradients, ecological site, and vegetation characteristics on resilience to disturbance and resistance to invasive species; (2) the effects of fire on individual plant species and communities, biological soil crusts, seed banks, soil nutrients, and hydrology; and (3) the role of fire severity, fire versus fire surrogate treatments, and post-fire grazing in determining ecosystem response. From this, we identify knowledge gaps and present a framework for predicting plant successional trajectories following wild and prescribed fires and fire surrogate treatments. Possibly the three most important ecological site characteristics that influence a site’s resilience (ability of the ecological site to recover from disturbance) and resistance to invasive species are soil temperature/moisture regimes and the composition and structure of vegetation on the ecological site just prior to the disturbance event.

  14. Molecular ecology of aquatic microbes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Abstracts of reports are presented from a meeting on Molecular Ecology of Aquatic Microbes. Topics included: opportunities offered to aquatic ecology by molecular biology; the role of aquatic microbes in biogeochemical cycles; characterization of the microbial community; the effect of the environment on aquatic microbes; and the targeting of specific biological processes.

  15. Indigenous Ecological Knowledge and Modern Western Ecological ...

    African Journals Online (AJOL)

    Indigenous knowledge is often dismissed as 'traditional and outdated', and hence irrelevant to modern ecological assessment. This theoretical paper critically examines the arguments advanced to elevate modern western ecological knowledge over indigenous ecological knowledge, as well as the sources and uses of ...

  16. Relationship among values, beliefs, norms and ecological behaviour.

    Science.gov (United States)

    González López, Antonio; Amérigo Cuervo-Arango, María

    2008-11-01

    The present study focuses mainly on the relationship between psychological constructs and ecological behaviour. Empirical analysis links personal values, ecological beliefs, consequences of environmental conditions, denial of ecological obligation, environmental control, personal norms and environment protection behaviour. Survey data from a path analysis of a Spanish sample of 403 individuals were used, showing that ecological beliefs, personal norms and eco-altruistic values have become the main psychological explanatory variables of environment protective behaviour. Ecological beliefs, when measured by the New Ecological Paradigm Scale, affected ecological behaviour decisively. Environmental and altruistic values were shown to be related to moral obligation, and a basic variable to understand behaviour. Personal norm mediated the effects of values and environmental control on ecological behaviour.

  17. The special effects of hypnosis and hypnotherapy: A contribution to an ecological model of therapeutic change.

    Science.gov (United States)

    Mende, Matthias

    2006-04-01

    There is ample evidence that hypnosis enhances the effectiveness of psychotherapy and produces some astounding effects of its own. In this paper, the effective components and principles of hypnosis and hypnotherapy are analyzed. The "special" hypnotic and hypnotherapeutic effects are linked to the fact that the ecological requirements of therapeutic change are taken into account implicitly and/or explicitly when working with hypnotic trances in a therapeutic setting. The hypnotic situation is described--theoretically and in case examples--as a therapeutic modality that gratifies and aligns the basic emotional needs to feel autonomous, related, competent, and oriented. It is shown how the hypnotic relationship can help promote a sound ecological balance between these needs--a balance that is deemed to be a necessary prerequisite for salutogenesis. Practical implications for planning hypnotherapeutic interventions are discussed.

  18. Genetic Engineering and Human Mental Ecology: Interlocking Effects and Educational Considerations

    OpenAIRE

    Affifi, Ramsey

    2017-01-01

    This paper describes some likely semiotic consequences of genetic engineering on what Gregory Bateson has called ?the mental ecology? (1979) of future humans, consequences that are less often raised in discussions surrounding the safety of GMOs (genetically modified organisms). The effects are as follows: an increased 1) habituation to the presence of GMOs in the environment, 2) normalization of empirically false assumptions grounding genetic reductionism, 3) acceptance that humans are capabl...

  19. Antibodies with higher bactericidal activity induced by a Neisseria gonorrhoeae Rmp deletion mutant strain.

    Directory of Open Access Journals (Sweden)

    Guocai Li

    Full Text Available Neisseria gonorrhoeae (N. gonorrhoeae outer membrane protein reduction modifiable protein (Rmp has strong immunogenicity. However, anti-Rmp antibodies block rather than preserve the antibacterial effects of protective antibodies, which hampers the development of vaccines for gonococcal infections. We herein constructed an Rmp deletion mutant strain of N. gonorrhoeae by gene homologous recombination. The 261-460 nucleotide residues of Rmp gene amplified from N. gonorrhoeae WHO-A strain were replaced with a kanamycin-resistant Kan gene amplified from pET-28a. The resultant hybridized DNA was transformed into N. gonorrhoeae WHO-A strain. PCR was used to screen the colonies in which wild-type Rmp gene was replaced with a mutant gene fragment. Western blotting revealed that the Rmp deletion mutant strain did not express Rmp protein. Rmp deletion did not alter the morphological and Gram staining properties of the mutant strain that grew slightly more slowly than the wild-type one. Rmp gene mutated stably throughout 25 generations of passage. Antibody-mediated complement-dependent cytotoxicity assay indicated that the antibodies induced by the mutant strain had evidently higher bactericidal activities than those induced by the wild-type strain. Further modification of the Rmp deletion mutant strain is still required in the development of novel live attenuated vaccines for gonorrhea by Opa genes deletion or screening of phenotypic variant strains that do not express Opa proteins.

  20. Anti-listerial Bactericidal Activity of Lactobacillus plantarum DM5 Isolated from Fermented Beverage Marcha.

    Science.gov (United States)

    Das, Deeplina; Goyal, Arun

    2013-09-01

    The strain Lactobacillus plantarum DM5 was isolated from fermented beverage Marcha of Sikkim and explored for its antagonistic activity against food-borne pathogens. The cell-free supernatant of L. plantarum DM5 showed antibacterial activity of 6,400 AU/mL in MRS medium (pH 6.0) against the indicator strain Staphylococcus aureus. MRS medium supplemented with 15 g/L of maltose at 37 °C under static condition yielded highest antimicrobial activity (6,400 AU/mL) with 3 % increase in specific activity when compared to 20 g/L glucose. The antimicrobial compound was heat stable (60 min at 100 °C) and was active over a wide pH range. It showed bactericidal effect on S. aureus and Listeria monocytogenes by causing 96 and 98 % of cell lysis, respectively. The cell morphology of the treated S. aureus and L. monocytogenes was completely deformed as revealed by scanning electron microscopy, suggesting the high potential of L. plantarum DM5 as natural preservatives in food industry. The antimicrobial compound was purified by 80 % ammonium sulphate precipitation and showed antimicrobial activity of 12,800 AU/mL with 19-fold purification and a molecular mass of 15.2 kDa, indicating the proteinaceous nature of the compound.

  1. Adopting an ecological view of metropolitan landscape: the case of "three circles" system for ecological construction and restoration in Beijing area.

    Science.gov (United States)

    Zhang, Feng; Zhang, Xin-shi

    2004-01-01

    Ecological construction and restoration for sustainable development are now a driving paradigm. It is increasingly recognized that ecological principles, especially landscape ecology theory, are not only necessary but also essential to maintain the long-term sustainability worldwide. Key landscape ecology principles-element, structure and process, dynamics, heterogeneity, hierarchies, connectivity, place and time were reviewed, and use Beijing area as a case study to illustrate how these principles might be applied to ecological construction and restoration, to eventually achieve sustainability. An example to more effectively incorporate the ecological principles in sustainable planning in China was presented.

  2. Protected areas as social-ecological systems: perspectives from resilience and social-ecological systems theory.

    Science.gov (United States)

    Cumming, Graeme S; Allen, Craig R

    2017-09-01

    Conservation biology and applied ecology increasingly recognize that natural resource management is both an outcome and a driver of social, economic, and ecological dynamics. Protected areas offer a fundamental approach to conserving ecosystems, but they are also social-ecological systems whose ecological management and sustainability are heavily influenced by people. This editorial, and the papers in the invited feature that it introduces, discuss three emerging themes in social-ecological systems approaches to understanding protected areas: (1) the resilience and sustainability of protected areas, including analyses of their internal dynamics, their effectiveness, and the resilience of the landscapes within which they occur; (2) the relevance of spatial context and scale for protected areas, including such factors as geographic connectivity, context, exchanges between protected areas and their surrounding landscapes, and scale dependency in the provision of ecosystem services; and (3) efforts to reframe what protected areas are and how they both define and are defined by the relationships of people and nature. These emerging themes have the potential to transform management and policy approaches for protected areas and have important implications for conservation, in both theory and practice. © 2017 by the Ecological Society of America.

  3. Applications Research of Microbial Ecological Preparation in Sea Cucumber Culture

    Science.gov (United States)

    Jiang, Jiahui; Wang, Guangyu

    2017-12-01

    At present, micro ecological preparation is widely applied in aquaculture with good effect. The application of micro ecological preparation in sea cucumber culture can effectively improve the economic benefits. The micro ecological preparation can play the role of inhibiting harmful bacteria, purifying water quality and saving culture cost in the process of sea cucumber culture. We should select appropriate bacteria, guarantee stable environment and use with long-term in the applications of microbial ecological preparation in sea cucumber culture to obtain good effects.

  4. Mechanistic effect modeling for ecological risk assessment: where to go from here?

    Science.gov (United States)

    Grimm, Volker; Martin, Benjamin T

    2013-07-01

    Mechanistic effect models (MEMs) consider the mechanisms of how chemicals affect individuals and ecological systems such as populations and communities. There is an increasing awareness that MEMs have high potential to make risk assessment of chemicals more ecologically relevant than current standard practice. Here we discuss what kinds of MEMs are needed to improve scientific and regulatory aspects of risk assessment. To make valid predictions for a wide range of environmental conditions, MEMs need to include a sufficient amount of emergence, for example, population dynamics emerging from what individual organisms do. We present 1 example where the life cycle of individuals is described using Dynamic Energy Budget theory. The resulting individual-based population model is thus parameterized at the individual level but correctly predicts multiple patterns at the population level. This is the case for both control and treated populations. We conclude that the state-of-the-art in mechanistic effect modeling has reached a level where MEMs are robust and predictive enough to be used in regulatory risk assessment. Mechanistic effect models will thus be used to advance the scientific basis of current standard practice and will, if their development follows Good Modeling Practice, be included in a standardized way in future regulatory risk assessments. Copyright © 2013 SETAC.

  5. Road ecology in environmental impact assessment

    International Nuclear Information System (INIS)

    Karlson, Mårten; Mörtberg, Ulla; Balfors, Berit

    2014-01-01

    Transport infrastructure has a wide array of effects on terrestrial and aquatic ecosystems, and road and railway networks are increasingly being associated with a loss of biodiversity worldwide. Environmental Impact Assessment (EIA) and Strategic Environmental Assessment (SEA) are two legal frameworks that concern physical planning, with the potential to identify, predict, mitigate and/or compensate transport infrastructure effects with negative impacts on biodiversity. The aim of this study was to review the treatment of ecological impacts in environmental assessment of transport infrastructure plans and projects. A literature review on the topic of EIA, SEA, biodiversity and transport infrastructure was conducted, and 17 problem categories on the treatment of biodiversity were formulated by means of a content analysis. A review of environmental impact statements and environmental reports (EIS/ER) produced between 2005 and 2013 in Sweden and the UK was then conducted using the list of problems as a checklist. The results show that the treatment of ecological impacts has improved substantially over the years, but that some impacts remain problematic; the treatment of fragmentation, the absence of quantitative analysis and that the impact assessment study area was in general delimited without consideration for the scales of ecological processes. Actions to improve the treatment of ecological impacts could include improved guidelines for spatial and temporal delimitation, and the establishment of a quantitative framework including tools, methods and threshold values. Additionally, capacity building and further method development of EIA and SEA friendly spatial ecological models can aid in clarifying the costs as well as the benefits in development/biodiversity tradeoffs. - Highlights: • The treatment of ecological impacts in EIA and SEA has improved. • Quantitative methods for ecological impact assessment were rarely used • Fragmentation effects were recognized

  6. Road ecology in environmental impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Karlson, Mårten, E-mail: mkarlso@kth.se; Mörtberg, Ulla, E-mail: mortberg@kth.se; Balfors, Berit, E-mail: balfors@kth.se

    2014-09-15

    Transport infrastructure has a wide array of effects on terrestrial and aquatic ecosystems, and road and railway networks are increasingly being associated with a loss of biodiversity worldwide. Environmental Impact Assessment (EIA) and Strategic Environmental Assessment (SEA) are two legal frameworks that concern physical planning, with the potential to identify, predict, mitigate and/or compensate transport infrastructure effects with negative impacts on biodiversity. The aim of this study was to review the treatment of ecological impacts in environmental assessment of transport infrastructure plans and projects. A literature review on the topic of EIA, SEA, biodiversity and transport infrastructure was conducted, and 17 problem categories on the treatment of biodiversity were formulated by means of a content analysis. A review of environmental impact statements and environmental reports (EIS/ER) produced between 2005 and 2013 in Sweden and the UK was then conducted using the list of problems as a checklist. The results show that the treatment of ecological impacts has improved substantially over the years, but that some impacts remain problematic; the treatment of fragmentation, the absence of quantitative analysis and that the impact assessment study area was in general delimited without consideration for the scales of ecological processes. Actions to improve the treatment of ecological impacts could include improved guidelines for spatial and temporal delimitation, and the establishment of a quantitative framework including tools, methods and threshold values. Additionally, capacity building and further method development of EIA and SEA friendly spatial ecological models can aid in clarifying the costs as well as the benefits in development/biodiversity tradeoffs. - Highlights: • The treatment of ecological impacts in EIA and SEA has improved. • Quantitative methods for ecological impact assessment were rarely used • Fragmentation effects were recognized

  7. Temporal ecology in the Anthropocene.

    Science.gov (United States)

    Wolkovich, E M; Cook, B I; McLauchlan, K K; Davies, T J

    2014-11-01

    Two fundamental axes - space and time - shape ecological systems. Over the last 30 years spatial ecology has developed as an integrative, multidisciplinary science that has improved our understanding of the ecological consequences of habitat fragmentation and loss. We argue that accelerating climate change - the effective manipulation of time by humans - has generated a current need to build an equivalent framework for temporal ecology. Climate change has at once pressed ecologists to understand and predict ecological dynamics in non-stationary environments, while also challenged fundamental assumptions of many concepts, models and approaches. However, similarities between space and time, especially related issues of scaling, provide an outline for improving ecological models and forecasting of temporal dynamics, while the unique attributes of time, particularly its emphasis on events and its singular direction, highlight where new approaches are needed. We emphasise how a renewed, interdisciplinary focus on time would coalesce related concepts, help develop new theories and methods and guide further data collection. The next challenge will be to unite predictive frameworks from spatial and temporal ecology to build robust forecasts of when and where environmental change will pose the largest threats to species and ecosystems, as well as identifying the best opportunities for conservation. © 2014 John Wiley & Sons Ltd/CNRS.

  8. Ecological principles relevant to nuclear war

    International Nuclear Information System (INIS)

    Hutchinson, T.C.; Cropper, W.P. Jr.; Grover, H.D.

    1985-01-01

    The ecological principles outlined are very basic ones; the authors anticipate a readership trained in a broad range of disciplines, including those unfamiliar with the academic discipline of ecology. The authors include substantial discussion on ecophysiology (i.e., the responses of organisms to their environment) because this is relevant to the new understanding of the potential climatic consequences of nuclear war. In particular, the physiological sensitivity of organisms to reduced levels of light and temperature are a key part of the analysis of the potential ecological effects and agricultural effects of nuclear war. Much of the ecological analysis has been organized around major biological units called biomes. The authors describe the biome concept and discuss some of the environmental-climatic factors that are believed to control biome distribution. Emphasis is given to plants because of their controlling influence on ecosystem functions through their role as primary producers. Future reports are needed to address more fully the potential effects on animals. Much more research needs to be done on both plant and animal responses to the types of perturbations possible for the aftermath of a nuclear war. Another important element for analysis of the potential ecological consequences of nuclear war concerns recovery processes. As the post-nuclear war environmental extremes ameliorate, ecological communities in devastated regions would begin to reorganize. It is not possible to predict the course of such a succession precisely, but some principles concerning post-perturbation replacement (such as seed banks and germination), relevant successional patterns, and organism strategies are discussed

  9. Ecological effects of contaminants and remedial actions in Bear Creek

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, G.R.; Loar, J.M.; Ryon, M.G.; Smith, J.G.; Stewart, A.J. (Oak Ridge National Lab., TN (United States)); Burris, J.A. (C. E. Environmental, Inc., Tallahassee, FL (United States))

    1992-01-01

    Ecological studies of the Bear Creek watershed, which drains the area surrounding several Oak Ridge Y-12 Plant waste disposal facilities, were initiated in May 1984 and are continuing at present. These studies consisted of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek, and they were followed by a presently ongoing monitoring phase that involves reduced sampling intensities. The characterization phase utilized two approaches: (1) instream sampling of benthic invertebrate and fish communities in Bear Creek to identify spatial and temporal patterns in distribution and abundance and (2) laboratory bioassays on water samples from Bear Creek and selected tributaries to identify potential sources of toxicity to biota. The monitoring phase of the ecological program relates to the long-term goals of identifying and prioritizing contaminant sources and assessing the effectiveness of remedial actions. It continues activities of the characterization phase at less frequent intervals. The Bear Greek Valley is a watershed that drains the area surrounding several closed Oak Ridge Y-12 Plant waste disposal facilities. Past waste disposal practices in Bear Creek Valley resulted in contamination of Bear Creek and consequent ecological damage. Extensive remedial actions have been proposed at waste sites, and some of the have been implemented or are now underway. The proposed study plan consists of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek in the first year followed by a reduction in sampling intensity during the monitoring phase of the plan. The results of sampling conducted from May 1984 through early 1989 are presented in this report.

  10. Ecological effects of contaminants and remedial actions in Bear Creek

    International Nuclear Information System (INIS)

    Southworth, G.R.; Loar, J.M.; Ryon, M.G.; Smith, J.G.; Stewart, A.J.; Burris, J.A.

    1992-01-01

    Ecological studies of the Bear Creek watershed, which drains the area surrounding several Oak Ridge Y-12 Plant waste disposal facilities, were initiated in May 1984 and are continuing at present. These studies consisted of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek, and they were followed by a presently ongoing monitoring phase that involves reduced sampling intensities. The characterization phase utilized two approaches: (1) instream sampling of benthic invertebrate and fish communities in Bear Creek to identify spatial and temporal patterns in distribution and abundance and (2) laboratory bioassays on water samples from Bear Creek and selected tributaries to identify potential sources of toxicity to biota. The monitoring phase of the ecological program relates to the long-term goals of identifying and prioritizing contaminant sources and assessing the effectiveness of remedial actions. It continues activities of the characterization phase at less frequent intervals. The Bear Greek Valley is a watershed that drains the area surrounding several closed Oak Ridge Y-12 Plant waste disposal facilities. Past waste disposal practices in Bear Creek Valley resulted in contamination of Bear Creek and consequent ecological damage. Extensive remedial actions have been proposed at waste sites, and some of the have been implemented or are now underway. The proposed study plan consists of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek in the first year followed by a reduction in sampling intensity during the monitoring phase of the plan. The results of sampling conducted from May 1984 through early 1989 are presented in this report

  11. Hydrophilic, bactericidal nanoheater-enabled reverse osmosis membranes to improve fouling resistance.

    Science.gov (United States)

    Ray, Jessica R; Tadepalli, Sirimuvva; Nergiz, Saide Z; Liu, Keng-Ku; You, Le; Tang, Yinjie; Singamaneni, Srikanth; Jun, Young-Shin

    2015-06-03

    Polyamide (PA) semipermeable membranes typically used for reverse osmosis water treatment processes are prone to fouling, which reduces the amount and quality of water produced. By synergistically coupling the photothermal and bactericidal properties of graphene oxide (GO) nanosheets, gold nanostars (AuNS), and hydrophilic polyethylene glycol (PEG) on PA reverse osmosis membrane surfaces, we have dramatically improved fouling resistance of these membranes. Batch fouling experiments from three classes of fouling are presented: mineral scaling (CaCO3 and CaSO4), organic fouling (humic acid), and biofouling (Escherichia coli). Systematic analyses and a variety of complementary techniques were used to elucidate fouling resistance mechanisms from each layer of modification on the membrane surface. Both mineral scaling and organic fouling were significantly reduced in PA-GO-AuNS-PEG membranes compared to other membranes. The PA-GO-AuNS-PEG membrane was also effective in killing all near-surface bacteria compared to PA membranes. In the PA-GO-AuNS-PEG membrane, the GO nanosheets act as templates for in situ AuNS growth, which then facilitated localized heating upon irradiation by an 808 nm laser inactivating bacteria on the membrane surface. Furthermore, AuNS in the membrane assisted PEG in preventing mineral scaling on the membrane surface. In flow-through flux and foulant rejection tests, PA-GO-AuNS-PEG membranes performed better than PA membranes in the presence of CaSO4 and humic acid model foulants. Therefore, the newly suggested membrane surface modifications will not only reduce fouling from RO feeds, but can improve overall membrane performance. Our innovative membrane design reported in this study can significantly extend the lifetime and water treatment efficacy of reverse osmosis membranes to alleviate escalating global water shortage from rising energy demands.

  12. Effect oof some antibiotics, disinfectants, and UV light on vability of vegetative cells and spores of C1. perfringend type A

    International Nuclear Information System (INIS)

    Rymkiewicz, D.

    1977-01-01

    Cells and spores of 40 strains of C1. perfringens type A, pathogenic for guinea pigs, were tested for resistance to antibiotics, drugs, disinfectants used in surgery and in bacteriological laboratories, and UV light. No correlation was found between thermoresistance of spores and their resistance to other bactericidal agents. Among the common disinfectants, iodine solution showed strong bactericidal and sporostatic activity. Good bactericidal effect was also obtained by combined action of Vescodin and UV light. Drug resistance of C1. perfringens type A strains changed clearly in the past 10 years. Strains inducing gangrene became resistant to penicillin and tetracyclines, which hitherto were commonly applied. Ampicilin can now be recommended, as the antibiotic with strong bactericidal and sporostatic action. (author)

  13. Central-place foraging and ecological effects of an invasive predator across multiple habitats.

    Science.gov (United States)

    Benkwitt, Cassandra E

    2016-10-01

    Cross-habitat foraging movements of predators can have widespread implications for predator and prey populations, community structure, nutrient transfer, and ecosystem function. Although central-place foraging models and other aspects of optimal foraging theory focus on individual predator behavior, they also provide useful frameworks for understanding the effects of predators on prey populations across multiple habitats. However, few studies have examined both the foraging behavior and ecological effects of nonnative predators across multiple habitats, and none has tested whether nonnative predators deplete prey in a manner predicted by these foraging models. I conducted behavioral observations of invasive lionfish (Pterois volitans) to determine whether they exhibit foraging movements similar to other central-place consumers. Then, I used a manipulative field experiment to test whether their effects on prey populations are consistent with three qualitative predictions from optimal foraging models. Specifically, I predicted that the effects of invasive lionfish on native prey will (1) occur at central sites first and then in surrounding habitats, (2) decrease with increasing distance away from their shelter site, and (3) extend to greater distances when prey patches are spaced closer together. Approximately 40% of lionfish exhibited short-term crepuscular foraging movements into surrounding habitats from the coral patch reefs where they shelter during daylight hours. Over the course of 7 weeks, lionfish depleted native fish populations on the coral patch reefs where they reside, and subsequently on small structures in the surrounding habitat. However, their effects did not decrease with increasing distance from the central shelter site and the influence of patch spacing was opposite the prediction. Instead, lionfish always had the greatest effects in areas with the highest prey densities. The differences between the predicted and observed effects of lionfish

  14. A brief introduction to mixed effects modelling and multi-model inference in ecology.

    Science.gov (United States)

    Harrison, Xavier A; Donaldson, Lynda; Correa-Cano, Maria Eugenia; Evans, Julian; Fisher, David N; Goodwin, Cecily E D; Robinson, Beth S; Hodgson, David J; Inger, Richard

    2018-01-01

    The use of linear mixed effects models (LMMs) is increasingly common in the analysis of biological data. Whilst LMMs offer a flexible approach to modelling a broad range of data types, ecological data are often complex and require complex model structures, and the fitting and interpretation of such models is not always straightforward. The ability to achieve robust biological inference requires that practitioners know how and when to apply these tools. Here, we provide a general overview of current methods for the application of LMMs to biological data, and highlight the typical pitfalls that can be encountered in the statistical modelling process. We tackle several issues regarding methods of model selection, with particular reference to the use of information theory and multi-model inference in ecology. We offer practical solutions and direct the reader to key references that provide further technical detail for those seeking a deeper understanding. This overview should serve as a widely accessible code of best practice for applying LMMs to complex biological problems and model structures, and in doing so improve the robustness of conclusions drawn from studies investigating ecological and evolutionary questions.

  15. Precipitation alters interactions in a grassland ecological community.

    Science.gov (United States)

    Deguines, Nicolas; Brashares, Justin S; Prugh, Laura R

    2017-03-01

    Climate change is transforming precipitation regimes world-wide. Changes in precipitation regimes are known to have powerful effects on plant productivity, but the consequences of these shifts for the dynamics of ecological communities are poorly understood. This knowledge gap hinders our ability to anticipate and mitigate the impacts of climate change on biodiversity. Precipitation may affect fauna through direct effects on physiology, behaviour or demography, through plant-mediated indirect effects, or by modifying interactions among species. In this paper, we examined the response of a semi-arid ecological community to a fivefold change in precipitation over 7 years. We examined the effects of precipitation on the dynamics of a grassland ecosystem in central California from 2007 to 2013. We conducted vegetation surveys, pitfall trapping of invertebrates, visual surveys of lizards and capture-mark-recapture surveys of rodents on 30 plots each year. We used structural equation modelling to evaluate the direct, indirect and modifying effects of precipitation on plants, ants, beetles, orthopterans, kangaroo rats, ground squirrels and lizards. We found pervasive effects of precipitation on the ecological community. Although precipitation increased plant biomass, direct effects on fauna were often stronger than plant-mediated effects. In addition, precipitation altered the sign or strength of consumer-resource and facilitative interactions among the faunal community such that negative or neutral interactions became positive or vice versa with increasing precipitation. These findings indicate that precipitation influences ecological communities in multiple ways beyond its recognized effects on primary productivity. Stochastic variation in precipitation may weaken the average strength of biotic interactions over time, thereby increasing ecosystem stability and resilience to climate change. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological

  16. Facile synthesis of gold nanoparticles on propylamine functionalized SBA-15 and effect of surface functionality of its enhanced bactericidal activity against gram positive bacteria

    International Nuclear Information System (INIS)

    Bhuyan, Diganta; Saikia, Mrinal; Saikia, Lakshi; Gogoi, Animesh; Saikia, Ratul

    2015-01-01

    The facile synthesis of an SBA-15-pr- + NH 3 .Au 0 nano-hybrid material by spontaneous autoreduction of aqueous chloroaurate anions on propylamine functionalized SBA-15 was successfully demonstrated. The as-synthesized SBA-15-pr- + NH 3 .Au 0 nano-hybrid material was well characterized using low and wide angle x-ray diffraction (XRD), N 2 adsorption–desorption isotherms, Fourier transform infrared (FTIR), transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDX), x-ray photoelectron spectroscopy (XPS), UV-Visible spectroscopy and atomic absorption spectroscopy (AAS). The activity of the nano-hybrid material as a potent bactericidal agent was successfully tested against Gram positive/negative bacteria viz. Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The colony killing percentage of Gram positive bacteria was found to be higher than Gram negative bacteria due to the stronger electrostatic interaction between the positively-charged amine functionality of SBA-15 and the negatively charged functionality of the bacterial cell wall. (paper)

  17. Toward Political Ecologies of Environmental Education

    Science.gov (United States)

    Henderson, Joseph A.; Zarger, Rebecca K.

    2017-01-01

    Drawing a causal line between educational practice and ecological impact is a difficult intellectual task given the complexity of variables at work between educational event and ecological effect. This is further complicated by the anthropological fact that diverse peoples interact with nature in myriad ways. Our environmental interactions are…

  18. Social Ecology, Deep Ecology and the Future of Green Political Thought.

    Science.gov (United States)

    Tokar, Brian

    1988-01-01

    Describes the differences which divide the social ecology movement and the Deep Ecology Movement. Discusses how each views population ecology, politics, natural resources, and ecological living. Calls for a unified ecological movement. (CW)

  19. Landscape Ecology

    DEFF Research Database (Denmark)

    Christensen, Andreas Aagaard; Brandt, Jesper; Svenningsen, Stig Roar

    2017-01-01

    Landscape ecology is an interdisciplinary field of research and practice that deals with the mutual association between the spatial configuration and ecological functioning of landscapes, exploring and describing processes involved in the differentiation of spaces within landscapes......, and the ecological significance of the patterns which are generated by such processes. In landscape ecology, perspectives drawn from existing academic disciplines are integrated based on a common, spatially explicit mode of analysis developed from classical holistic geography, emphasizing spatial and landscape...... pattern analysis and ecological interaction of land units. The landscape is seen as a holon: an assemblage of interrelated phenomena, both cultural and biophysical, that together form a complex whole. Enduring challenges to landscape ecology include the need to develop a systematic approach able...

  20. Effects of ionizing radiation upon natural populations and ecosystems. Final report. [Ecological perspectives in land use planning

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, J.F.

    1976-01-01

    Accomplishments throughout a 10-year period summarized include: a study of the effects of radiation from a ..gamma.. source on the ecology of the El Verde rain forest in Puerto Rico, with emphasis on the role of secondary succession in the recovery of forest ecosystems following irradiation; the effects of light and temperature on gaseous exchange in trees using /sup 14/CO/sub 2/ as a tracer in Palcourea; the nature of the sensitivity of pine trees to ionizing radiation and the possible synergistic effects of elevated ozone levels on radiosensitivity; the combined effects of radioactive and thermal effluents on plant communities of a swamp hardwood forest; and the development of a new conceptual approach to the evaluation of environmental quality, with emphasis on ecological perspectives in land use planning. (CH)

  1. Ecological effects of aphid abundance, genotypic variation, and contemporary evolution on plants.

    Science.gov (United States)

    Turley, Nash E; Johnson, Marc T J

    2015-07-01

    Genetic variation and contemporary evolution within populations can shape the strength and nature of species interactions, but the relative importance of these forces compared to other ecological factors is unclear. We conducted a field experiment testing the effects of genotypic variation, abundance, and presence/absence of green peach aphids (Myzus persicae) on the growth, leaf nitrogen, and carbon of two plant species (Brassica napus and Solanum nigrum). Aphid genotype affected B. napus but not S. nigrum biomass explaining 20 and 7% of the total variation, respectively. Averaging across both plant species, the presence/absence of aphids had a 1.6× larger effect size (Cohen's d) than aphid genotype, and aphid abundance had the strongest negative effects on plant biomass explaining 29% of the total variation. On B. napus, aphid genotypes had different effects on leaf nitrogen depending on their abundance. Aphids did not influence leaf nitrogen in S. nigrum nor leaf carbon in either species. We conducted a second experiment in the field to test whether contemporary evolution could affect plant performance. Aphid populations evolved in as little as five generations, but the rate and direction of this evolution did not consistently vary between plant species. On one host species (B. napus), faster evolving populations had greater negative effects on host plant biomass, with aphid evolutionary rate explaining 23% of the variation in host plant biomass. Together, these results show that genetic variation and evolution in an insect herbivore can play important roles in shaping host plant ecology.

  2. About the Mid-Continent Ecology Division (MED) of EPA's National Health and Environmental Effects Research Laboratory

    Science.gov (United States)

    The Mid-Continent Ecology Division (MED) conducts innovative research and predictive modeling to document and forecast the effects of pollutants on the integrity of watersheds and freshwater ecosystems.

  3. Effect of Ecological Restoration on Body Condition of a Predator.

    Directory of Open Access Journals (Sweden)

    Daniel González-Tokman

    Full Text Available Ecological restoration attempts to recover the structure and function of ecosystems that have been degraded by human activities. A crucial test of ecosystem recovery would be to determine whether individuals in restored environments are as healthy as those in conserved environments. However, the impact of restoration on physiology of terrestrial animals has never been tested. Here, we evaluated the effect of two restoration methods on body condition measured as body size, body mass, lipid and muscle content of the spider Nephila clavipes in a tropical dry forest that has suffered chronic disturbance due to cattle grazing. We used experimental plots that had been excluded from disturbance by cattle grazing during eight years. Plots were either planted with native trees (i. e. maximal intervention, or only excluded from disturbance (i. e. minimal intervention, and were compared with control conserved (remnants of original forest and disturbed plots (where cattle is allowed to graze. We predicted (1 better body condition in spiders of conserved and restored sites, compared to disturbed sites, and (2 better body condition in plots with maximal intervention than in plots with minimal intervention. The first prediction was not supported in males or females, and the second prediction was only supported in females: body dry mass was higher in planted than in conserved plots for spiders of both sexes and also higher that in disturbed plots for males, suggesting that plantings are providing more resources. We discuss how different life histories and environmental pressures, such as food availability, parasitism, and competition for resources can explain our contrasting findings in male and female spiders. By studying animal physiology in restoration experiments it is possible to understand the mechanistic basis of ecological and evolutionary processes that determine success of ecological restoration.

  4. Ecology

    Science.gov (United States)

    Ternjej, Ivancica; Mihaljevic, Zlatko

    2017-10-01

    Ecology is a science that studies the mutual interactions between organisms and their environment. The fundamental subject of interest in ecology is the individual. Topics of interest to ecologists include the diversity, distribution and number of particular organisms, as well as cooperation and competition between organisms, both within and among ecosystems. Today, ecology is a multidisciplinary science. This is particularly true when the subject of interest is the ecosystem or biosphere, which requires the knowledge and input of biologists, chemists, physicists, geologists, geographists, climatologists, hydrologists and many other experts. Ecology is applied in a science of restoration, repairing disturbed sites through human intervention, in natural resource management, and in environmental impact assessments.

  5. Carnivore repatriation and holarctic prey: narrowing the deficit in ecological effectiveness.

    Science.gov (United States)

    Berger, Joel

    2007-08-01

    The continuing global decline of large carnivores has catalyzed great interest in reintroduction to restore populations and to reestablish ecologically functional relationships. I used variation in the distribution of four Holarctic prey species and their behavior as proxies to investigate the pace and intensity by which responses are lost or reinvigorated by carnivore repatriation. By simulating the presence of wolves (Canis lupus), tigers (Panthera tigris), and brown bears (Ursus arctos) at 19 transcontinental sites, I assayed three metrics of prey performance in areas with no large terrestrial carnivores (the polar islands of Greenland and Svalbard), extant native carnivores (Eastern Siberian Shield, boreal Canada, and Alaska); and repatriated carnivores (the Yellowstone region and Rocky Mountains). The loss and reestablishment of large carnivores changed the ecological effectiveness of systems by (1) dampening immediate group benefits, diminishing awareness, and diminishing flight reaction in caribou (Rangifer tarandus) where predation was eliminated and (2) reinstituting sensitivity to carnivores by elk (Cervus elaphus) and moose (Alces alces) in the Yellowstone region to levels observed in Asian elk when sympatric with Siberian tigers and wolves or in Alaskan moose sympatric with wolves. Behavioral compensation to reintroduced carnivores occurred within a single generation, but only the vigilance reaction of bison (Bison bison) in Yellowstone exceeded that of their wolf-exposed conspecifics from boreal Canada. Beyond these overt responses by prey, snow depth and distance to suitably vegetated habitat was related to heightened vigilance in moose and elk, respectively, but only at sites with carnivores. These findings are insufficient to determine whether similar patterns might apply to other species or in areas with alien predators, and they suggest that the presumed excessive vulnerability of naïve prey to repatriated carnivores may be ill-founded. Although

  6. Estimating the Cumulative Ecological Effect of Local Scale Landscape Changes in South Florida

    Science.gov (United States)

    Hogan, Dianna M.; Labiosa, William; Pearlstine, Leonard; Hallac, David; Strong, David; Hearn, Paul; Bernknopf, Richard

    2012-01-01

    Ecosystem restoration in south Florida is a state and national priority centered on the Everglades wetlands. However, urban development pressures affect the restoration potential and remaining habitat functions of the natural undeveloped areas. Land use (LU) planning often focuses at the local level, but a better understanding of the cumulative effects of small projects at the landscape level is needed to support ecosystem restoration and preservation. The South Florida Ecosystem Portfolio Model (SFL EPM) is a regional LU planning tool developed to help stakeholders visualize LU scenario evaluation and improve communication about regional effects of LU decisions. One component of the SFL EPM is ecological value (EV), which is evaluated through modeled ecological criteria related to ecosystem services using metrics for (1) biodiversity potential, (2) threatened and endangered species, (3) rare and unique habitats, (4) landscape pattern and fragmentation, (5) water quality buffer potential, and (6) ecological restoration potential. In this article, we demonstrate the calculation of EV using two case studies: (1) assessing altered EV in the Biscayne Gateway area by comparing 2004 LU to potential LU in 2025 and 2050, and (2) the cumulative impact of adding limestone mines south of Miami. Our analyses spatially convey changing regional EV resulting from conversion of local natural and agricultural areas to urban, industrial, or extractive use. Different simulated local LU scenarios may result in different alterations in calculated regional EV. These case studies demonstrate methods that may facilitate evaluation of potential future LU patterns and incorporate EV into decision making.

  7. Ecological land classification and terrestrial environment effects assessment for the Port Hope and Port Granby projects

    International Nuclear Information System (INIS)

    Taylor, M.; Wittkugel, U.; Kleb, H.

    2006-01-01

    The Ecological Land Classification system was developed to provide a standardized methodology for describing plant communities and wildlife habitat in southern Ontario. The method employs a hierarchical classification system. It can be applied at different levels of accuracy, i.e., at regional, sub-regional, and local scales with an increasing differentiation of vegetation communities. The standardization of the approach permits a comparison of vegetation communities from different sites and an evaluation of the rarity of these communities within the province. Further, the approach facilitates the monitoring of changes in terrestrial communities with time. These characteristics make Ecological Land Classification mapping a useful tool for environmental assessment such as the ones undertaken for the Port Hope and Port Granby Long-Term Waste Management Projects, which were conducted pursuant to the Canadian Environmental Assessment Act 1992. In the context of the Environmental Assessment for the Port Hope and Port Granby Projects, an Ecological Land Classification study was undertaken to characterize the terrestrial environment at regional, local and site levels. Vegetation patches (polygons) were delineated on the basis of air photo interpretation. The individual polygons were then visited for detailed inventory and classified to the most detailed level; that is to the vegetation type. Plant communities were then compared with those listed in the Ontario Natural Heritage Information Centre database to determine their rarity and to determine where they rank as Valued Ecosystem Components. Ecological Land Classification mapping results were used in the assessment of effects to Valued Ecosystem Components. A spatial analysis of the digitized vegetation maps showed the geographic extent of habitat losses and impairments due to various project works and activities. Landscape rehabilitation strategies and concepts were subsequently developed based on Ecological Land

  8. Ecological mechanisms linking protected areas to surrounding lands.

    Science.gov (United States)

    Hansen, Andrew J; DeFries, Ruth

    2007-06-01

    Land use is expanding and intensifying in the unprotected lands surrounding many of the world's protected areas. The influence of this land use change on ecological processes is poorly understood. The goal of this paper is to draw on ecological theory to provide a synthetic framework for understanding how land use change around protected areas may alter ecological processes and biodiversity within protected areas and to provide a basis for identifying scientifically based management alternatives. We first present a conceptual model of protected areas embedded within larger ecosystems that often include surrounding human land use. Drawing on case studies in this Invited Feature, we then explore a comprehensive set of ecological mechanisms by which land use on surrounding lands may influence ecological processes and biodiversity within reserves. These mechanisms involve changes in ecosystem size, with implications for minimum dynamic area, species-area effect, and trophic structure; altered flows of materials and disturbances into and out of reserves; effects on crucial habitats for seasonal and migration movements and population source/sink dynamics; and exposure to humans through hunting, poaching, exotics species, and disease. These ecological mechanisms provide a basis for assessing the vulnerability of protected areas to land use. They also suggest criteria for designing regional management to sustain protected areas in the context of surrounding human land use. These design criteria include maximizing the area of functional habitats, identifying and maintaining ecological process zones, maintaining key migration and source habitats, and managing human proximity and edge effects.

  9. Nutrition, ecology and nutritional ecology: towardan integrated framework

    DEFF Research Database (Denmark)

    Raubenheimer, David; Simpson, Steven J.; Mayntz, David

    2009-01-01

    requirements: it should be nutritionally explicit, organismally explicit, and ecologically explicit. 4. We evaluate against these criteria four existing frameworks (Optimal Foraging Theory, Classical Insect Nutritional Ecology, the Geometric Framework for nutrition, and Ecological Stoichiometry), and conclude...... in its own right? 2. We suggest that the distinctive feature of nutritional ecology is its integrative nature, and that the field would benefit from more attention to formalizing a theoretical and quantitative framework for developing this. 3. Such a framework, we propose, should satisfy three minimal...

  10. [Dynamic changes of ecological footprint and ecological capacity in Fujian Province].

    Science.gov (United States)

    Weng, Boqi; Wang, Yixiang; Huang, Yibin; Ying, Zhaoyang; Huang, Qinlou

    2006-11-01

    The analysis on the dynamic changes of ecological footprint and ecological capacity in Fujian Province showed that in 1999-2003, the ecological footprint per capita in the Province increased from 1.428 hm2 to 1.658 hm2, while the ecological capacity per capita decreased from 0.683 hm2 to 0.607 hm2, with an increased ecological deficit year after year. The contradiction between the ecological footprint and ecological capacity pricked up gradually, and the ecological environment was at risk. There existed a severe imbalance in the supply and demand of ecological footprint per capita. The main body of the demands was grassland and fossil fuel, accouting for 55.74% - 63.43% of the total, while their supply only occupied 0.77% - 0.82% and next to nothing of the ecological capacity per capita, respectively. As a whole, the ecological footprint per ten thousand yuan GDP declined in the five years, indicating that the resources use efficiency in the Province was improved gradually. Based on the analysis of the present situation of the economic development and resources distribution in the Province, the strategies on reducing ecological deficit were put forward.

  11. Fusion between fluid liposomes and intact bacteria: study of driving parameters and in vitro bactericidal efficacy

    Directory of Open Access Journals (Sweden)

    Wang Z

    2016-08-01

    composition (91% and 71%, respectively. Divalent cations increased the degree of fusion in the sequence Fe2+ > Mg2+ > Ca2+ > Ba2+ whereas temperatures lower than the phase transition temperature of DPPC/DMPG (9:1 vesicles decreased their fusion capacity. Acidic as well as basic pHs conferred higher degrees of fusion (54% and 45%, respectively when compared to neutral pH (35%. Conclusion: Based on the results of this study, a possible mechanism involving cationic bridging between bacterial negatively charged lipopolysaccharide and fluid liposomes DMPG phospholipids was outlined. Furthermore, the fluid liposomal-encapsulated tobramycin was prepared, and the in vitro bactericidal effects were also investigated. Keywords: fusion, lipid-mixing assay, lipid composition

  12. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1998

    International Nuclear Information System (INIS)

    Wein, G.; Rosier, B.

    1998-01-01

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs

  13. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Wein, G.; Rosier, B.

    1998-12-31

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs.

  14. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1997

    International Nuclear Information System (INIS)

    Wein, G.; Rosier, B.

    1997-01-01

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs

  15. Savannah River Ecology Laboratory, annual technical progress report of ecological research for the year ending June 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Wein, G.; Rosier, B.

    1997-12-31

    This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs.

  16. Protected areas as social-ecological systems: perspectives from resilience and social-ecological systems theory

    Science.gov (United States)

    Cumming, Graeme S.; Allen, Craig R.

    2017-01-01

    Conservation biology and applied ecology increasingly recognize that natural resource management is both an outcome and a driver of social, economic, and ecological dynamics. Protected areas offer a fundamental approach to conserving ecosystems, but they are also social-ecological systems whose ecological management and sustainability are heavily influenced by people. This editorial, and the papers in the invited feature that it introduces, discuss three emerging themes in social-ecological systems approaches to understanding protected areas: (1) the resilience and sustainability of protected areas, including analyses of their internal dynamics, their effectiveness, and the resilience of the landscapes within which they occur; (2) the relevance of spatial context and scale for protected areas, including such factors as geographic connectivity, context, exchanges between protected areas and their surrounding landscapes, and scale dependency in the provision of ecosystem services; and (3) efforts to reframe what protected areas are and how they both define and are defined by the relationships of people and nature. These emerging themes have the potential to transform management and policy approaches for protected areas and have important implications for conservation, in both theory and practice.

  17. Animal behaviour shapes the ecological effects of ocean acidification and warming: moving from individual to community-level responses.

    Science.gov (United States)

    Nagelkerken, Ivan; Munday, Philip L

    2016-03-01

    Biological communities are shaped by complex interactions between organisms and their environment as well as interactions with other species. Humans are rapidly changing the marine environment through increasing greenhouse gas emissions, resulting in ocean warming and acidification. The first response by animals to environmental change is predominantly through modification of their behaviour, which in turn affects species interactions and ecological processes. Yet, many climate change studies ignore animal behaviour. Furthermore, our current knowledge of how global change alters animal behaviour is mostly restricted to single species, life phases and stressors, leading to an incomplete view of how coinciding climate stressors can affect the ecological interactions that structure biological communities. Here, we first review studies on the effects of warming and acidification on the behaviour of marine animals. We demonstrate how pervasive the effects of global change are on a wide range of critical behaviours that determine the persistence of species and their success in ecological communities. We then evaluate several approaches to studying the ecological effects of warming and acidification, and identify knowledge gaps that need to be filled, to better understand how global change will affect marine populations and communities through altered animal behaviours. Our review provides a synthesis of the far-reaching consequences that behavioural changes could have for marine ecosystems in a rapidly changing environment. Without considering the pervasive effects of climate change on animal behaviour we will limit our ability to forecast the impacts of ocean change and provide insights that can aid management strategies. © 2015 John Wiley & Sons Ltd.

  18. Development of a zoning-based environmental-ecological-coupled model for lakes to assess lake restoration effect

    Science.gov (United States)

    Xu, Mengjia; Zou, Changxin; Zhao, Yanwei

    2017-04-01

    coupled models have been applied to simulate the spatial variation trends of ecological condition under ecological water supplement as an example to reflect the application effect in lake restoration and management. The simulation results indicate that the models can provide a useful tool for lake restoration and management. The simulated spatial variation trends can provide a foundation for establishing permissible ranges for a selected set of water quality indices for a series of management measures such as watershed pollution load control and ecological water transfer. Meanwhile, the coupled models can help us to understand processes taking place and the relations of interaction between components in the lake ecosystem and external conditions. Taken together, the proposed models we established show some promising applications as middle-scale or large-scale lake management tools for pollution load control and ecological water transfer. These tools quantify the implications of proposed future water management decisions.

  19. Ecological perspective: Linking ecology, GIS, and remote sensing to ecosystem management

    Science.gov (United States)

    Allen, Craig D.; Sample, V. Alaric

    1994-01-01

    Awareness of significant human impacts on the ecology of Earth's landscapes is not new (Thomas 1956). Over the past decade (Forman and Godron 1986, Urban et a1. 1987) applications of geographic information systems (GIS) and remote sensing technologies have supported a rapid rise in landscape.stale research. The heightened recognition within the research community of the ecological linkages between local sites and larger spatial scales has spawned increasing calls for more holistic management of landscapes (Noss 1983, Harris 1984, Risser 1985, Norse et al. 1986, Agee and Johnson 1988, Franklin 1989, Brooks and Grant 1992, Endangered Species Update-Special Issue 1993, Crow 1994, Grumbine 1994). As a result agencies such as the U.S. Forest Service, U.S. Fish and Wildlife Service, and National Park Service are now converging on "ecosystem management" as a new paradigm to sustainably manage wildlands and maintain biodiversity. However, as this transition occurs, several impediments to implementation of this new paradigm persist, including(1) significant uncenainty among many land managers about the definition and goals of ecosystem management,(2) inadequate ecological information on the past and present processes and structural conditions of target ecosystems,(3) insufficient experience on the part of land managers with the rapidly diversifying array of GIS and remote sensing tools to effectively use them to support ecology-based land management, and(4) a paucity of intimate, long-term relationships between people (including land managers) and the particular landscape communities to which they belong.This chapter provides an ecological perspective on these issues as applied to ecosystem management in a southwestern U.S. landscape.

  20. Biosynthesis and recovery of rod-shaped tellurium nanoparticles and their bactericidal activities

    Energy Technology Data Exchange (ETDEWEB)

    Zare, Bijan; Faramarzi, Mohammad Ali; Sepehrizadeh, Zargham [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. Box 14155-6451 Tehran (Iran, Islamic Republic of); Shakibaie, Mojtaba [Department of Pharmacognosy and Biotechnology, School of Pharmacy, Pharmaceutics Research Center, Kerman University of Medical Sciences, P.O. Box 76175-493 Kerman (Iran, Islamic Republic of); Rezaie, Sassan [Department of Medical Biotechnology, School of Advanced Medical Technologies, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shahverdi, Ahmad Reza, E-mail: shahverd@sina.tums.ac.ir [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. Box 14155-6451 Tehran (Iran, Islamic Republic of)

    2012-11-15

    Highlights: ► Biosynthesis of rod shape tellurium nanoparticles with a hexagonal crystal structure. ► Extraction procedure for isolation of tellurium nanoparticles from Bacillus sp. BZ. ► Extracted tellurium nanoparticles have good bactericidal activity against some bacteria. -- Abstract: In this study, a tellurium-transforming Bacillus sp. BZ was isolated from the Caspian Sea in northern Iran. The isolate was identified by various tests and 16S rDNA analysis, and then used to prepare elemental tellurium nanoparticles. The isolate was subsequently used for the intracellular biosynthesis of elemental tellurium nanoparticles. The biogenic nanoparticles were released by liquid nitrogen and purified by an n-octyl alcohol water extraction system. The shape, size, and composition of the extracted nanoparticles were characterized. The transmission electron micrograph showed rod-shaped nanoparticles with dimensions of about 20 nm × 180 nm. The energy dispersive X-ray and X-ray diffraction spectra respectively demonstrated that the extracted nanoparticles consisted of only tellurium and have a hexagonal crystal structure. This is the first study to demonstrate a biological method for synthesizing rod-shaped elemental tellurium by a Bacillus sp., its extraction and its antibacterial activity against different clinical isolates.

  1. Biosynthesis and recovery of rod-shaped tellurium nanoparticles and their bactericidal activities

    International Nuclear Information System (INIS)

    Zare, Bijan; Faramarzi, Mohammad Ali; Sepehrizadeh, Zargham; Shakibaie, Mojtaba; Rezaie, Sassan; Shahverdi, Ahmad Reza

    2012-01-01

    Highlights: ► Biosynthesis of rod shape tellurium nanoparticles with a hexagonal crystal structure. ► Extraction procedure for isolation of tellurium nanoparticles from Bacillus sp. BZ. ► Extracted tellurium nanoparticles have good bactericidal activity against some bacteria. -- Abstract: In this study, a tellurium-transforming Bacillus sp. BZ was isolated from the Caspian Sea in northern Iran. The isolate was identified by various tests and 16S rDNA analysis, and then used to prepare elemental tellurium nanoparticles. The isolate was subsequently used for the intracellular biosynthesis of elemental tellurium nanoparticles. The biogenic nanoparticles were released by liquid nitrogen and purified by an n-octyl alcohol water extraction system. The shape, size, and composition of the extracted nanoparticles were characterized. The transmission electron micrograph showed rod-shaped nanoparticles with dimensions of about 20 nm × 180 nm. The energy dispersive X-ray and X-ray diffraction spectra respectively demonstrated that the extracted nanoparticles consisted of only tellurium and have a hexagonal crystal structure. This is the first study to demonstrate a biological method for synthesizing rod-shaped elemental tellurium by a Bacillus sp., its extraction and its antibacterial activity against different clinical isolates.

  2. Synthesis of nanosilver particles by reverse micelle method and study of their bactericidal properties

    Energy Technology Data Exchange (ETDEWEB)

    Tran Thi Ngoc Dung; Ngo Quoc Buu; Dang Viet Quang; Le Anh Bang; Nguyen Hoai Chau; Nguyen Thi Ly [Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Distr., Hanoi (Viet Nam); Huynh Thi Ha [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Distr., Hanoi (Viet Nam); Nguyen Vu Trung [National Institute for Infectious and Tropical Diseases, 1 Ton That Tung, Dong Da Distr., Hanoi (Viet Nam)], E-mail: ttndzung@yahoo.com, E-mail: buu_nq@yahoo.com

    2009-09-01

    Nanosilver particles have been synthesized by the reverse micelle method, where AgNO{sub 3} was used as a silver ions source, NaBH{sub 4} and quercetin - as reducing agents, CTAB, SDOSS and AOT- as surfactants, while the stabilizer was Vietnamese chitosan. Studying the factors influencing the process of nanosilver particle formation, it was shown that the particle size of the nanosilver products depends on the concentration of the reaction components and their stoichiometric ratio. It was also shown that the reaction system using AOT surfactant is capable of producing nanosilver particles with smallest nanoparticles ({phi}{sub av} {approx} 5 nm) and good particle-size distribution. The study on bactericidal activity of the nanosilver products indicated that the disinfecting solution with a nanosilver concentration of 3 ppm was able to inhibit all E.coli and Coliforms, TPC and fungi at 15 ppm, while Vibrio cholerae cells were inactivated completely with 0.5 ppm of nanosilver after 30 minutes exposition.

  3. Priorities for the next decade of research in radiation ecology

    International Nuclear Information System (INIS)

    Hoffman, F.O. Jr.; McCormick, J.F.

    1987-01-01

    Radiation ecology is the study of the fate and effects of ionizing radiations in the environment. The 1986 Chernobyl accident provides unprecedented opportunities to test models of the transport of a great variety of radionuclides in a variety of ecosystems under a variety of conditions throughout the world. International collaboration provides exciting opportunities to explore the fate of radionuclides on a global scale. Our understanding of ecological effects of ionizing radiations is based almost entirely upon results of point source gamma studies such as those described in this symposium. While results of these studies are incomplete and insufficient, even less is known of ecological effects resulting from high levels of radioactive fallout. High priority should be given to completing long term studies of previously irradiated ecosystems and to initiating studies of the ecological effects of radioactive fallout. The most challenging task is to improve and couple our knowledge of radionuclide transport, radiation dosimetry and ecological effects so that, for a given level of radioactivity released into specific ecosystems, we can predict immediate and long term consequences

  4. Ecological effects of invasive alien species on native communities, with particular emphasis on the interactions between aphids and ladybirds

    Czech Academy of Sciences Publication Activity Database

    Kindlmann, Pavel; Ameixa, Olga; Dixon, Anthony F. G.

    2011-01-01

    Roč. 56, č. 4 (2011), s. 469-476 ISSN 1386-6141 R&D Projects: GA MŠk LC06073; GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520 Keywords : invasive alien species * predators * insect pest s * ecological effects * intraguild predation Subject RIV: EH - Ecology, Behaviour Impact factor: 1.927, year: 2011

  5. The Effect of Environmental Education on the Ecological Literacy of First-Year College Students

    Science.gov (United States)

    Bruyere, Brett L.

    2008-01-01

    This article assesses the viability of a value-attitude-behavior hierarchy within the context of four environmentally responsible behavior types of first-year college students. The research also studies the effect of knowledge on attitude and behavior, and discusses the implications of the results for understanding the ecological literacy of…

  6. Using ecological production functions to link ecological ...

    Science.gov (United States)

    Ecological production functions (EPFs) link ecosystems, stressors, and management actions to ecosystem services (ES) production. Although EPFs are acknowledged as being essential to improve environmental management, their use in ecological risk assessment has received relatively little attention. Ecological production functions may be defined as usable expressions (i.e., models) of the processes by which ecosystems produce ES, often including external influences on those processes. We identify key attributes of EPFs and discuss both actual and idealized examples of their use to inform decision making. Whenever possible, EPFs should estimate final, rather than intermediate, ES. Although various types of EPFs have been developed, we suggest that EPFs are more useful for decision making if they quantify ES outcomes, respond to ecosystem condition, respond to stressor levels or management scenarios, reflect ecological complexity, rely on data with broad coverage, have performed well previously, are practical to use, and are open and transparent. In an example using pesticides, we illustrate how EPFs with these attributes could enable the inclusion of ES in ecological risk assessment. The biggest challenges to ES inclusion are limited data sets that are easily adapted for use in modeling EPFs and generally poor understanding of linkages among ecological components and the processes that ultimately deliver the ES. We conclude by advocating for the incorporation into E

  7. Bactericidal peptidoglycan recognition protein induces oxidative stress in Escherichia coli through a block in respiratory chain and increase in central carbon catabolism.

    Science.gov (United States)

    Kashyap, Des R; Kuzma, Marcin; Kowalczyk, Dominik A; Gupta, Dipika; Dziarski, Roman

    2017-09-01

    Mammalian Peptidoglycan Recognition Proteins (PGRPs) kill both Gram-positive and Gram-negative bacteria through simultaneous induction of oxidative, thiol and metal stress responses in bacteria. However, metabolic pathways through which PGRPs induce these bactericidal stress responses are unknown. We screened Keio collection of Escherichia coli deletion mutants and revealed that deleting genes for respiratory chain flavoproteins or for tricarboxylic acid (TCA) cycle resulted in increased resistance of E. coli to PGRP killing. PGRP-induced killing depended on the production of hydrogen peroxide, which required increased supply of NADH for respiratory chain oxidoreductases from central carbon catabolism (glycolysis and TCA cycle), and was controlled by cAMP-Crp. Bactericidal PGRP induced a rapid decrease in respiration, which suggested that the main source of increased production of hydrogen peroxide was a block in respiratory chain and diversion of electrons from NADH oxidoreductases to oxygen. CpxRA two-component system was a negative regulator of PGRP-induced oxidative stress. By contrast, PGRP-induced thiol stress (depletion of thiols) and metal stress (increase in intracellular free Zn 2+ through influx of extracellular Zn 2+ ) were mostly independent of oxidative stress. Thus, manipulating pathways that induce oxidative, thiol and metal stress in bacteria could be a useful strategy to design new approaches to antibacterial therapy. © 2017 John Wiley & Sons Ltd.

  8. Functional remediation components: A conceptual method of evaluating the effects of remediation on risks to ecological receptors.

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael; Bunn, Amoret; Downs, Janelle; Jeitner, Christian; Pittfield, Taryn; Salisbury, Jennifer

    2016-01-01

    Governmental agencies, regulators, health professionals, tribal leaders, and the public are faced with understanding and evaluating the effects of cleanup activities on species, populations, and ecosystems. While engineers and managers understand the processes involved in different remediation types such as capping, pump and treat, and natural attenuation, there is often a disconnect between (1) how ecologists view the influence of different types of remediation, (2) how the public perceives them, and (3) how engineers understand them. The overall goal of the present investigation was to define the components of remediation types (= functional remediation). Objectives were to (1) define and describe functional components of remediation, regardless of the remediation type, (2) provide examples of each functional remediation component, and (3) explore potential effects of functional remediation components in the post-cleanup phase that may involve continued monitoring and assessment. Functional remediation components include types, numbers, and intensity of people, trucks, heavy equipment, pipes, and drill holes, among others. Several components may be involved in each remediation type, and each results in ecological effects, ranging from trampling of plants, to spreading invasive species, to disturbing rare species, and to creating fragmented habitats. In some cases remediation may exert a greater effect on ecological receptors than leaving the limited contamination in place. A goal of this conceptualization is to break down functional components of remediation such that managers, regulators, and the public might assess the effects of timing, extent, and duration of different remediation options on ecological systems.

  9. Principles for ecologically based invasive plant management

    Science.gov (United States)

    Jeremy J. James; Brenda S. Smith; Edward A. Vasquez; Roger L. Sheley

    2010-01-01

    Land managers have long identified a critical need for a practical and effective framework for designing restoration strategies, especially where invasive plants dominate. A holistic, ecologically based, invasive plant management (EBIPM) framework that integrates ecosystem health assessment, knowledge of ecological processes, and adaptive management into a successional...

  10. Ecological taxes in some European countries

    Directory of Open Access Journals (Sweden)

    Filipović Sanja

    2004-01-01

    Full Text Available Production and consumption of fossil fuels is one of the major causes of the green house effect, which is in economics known as a form of ecological externality. Fiscal solution, as one way of internalization of externalities, is based on polluters-pay principle and the imposition of tax on emission. Although the implementation of ecological tax was intensified during the previous decade, fiscal revenues are modest and account for only 5% of the total fiscal revenues of the European Union. Taxes on energetic products, accounting for 76%, are dominant among ecological taxes. Since the EU Directive 82/92 imposes minimum excise rates on oil products, during the last decade Central Eastern European countries have increased excise rates on fossil fuels and fully engaged in the field of ecological policy.

  11. Surface functionalization of Cu-Ni alloys via grafting of a bactericidal polymer for inhibiting biocorrosion by Desulfovibrio desulfuricans in anaerobic seawater.

    Science.gov (United States)

    Yuan, S J; Liu, C K; Pehkonen, S O; Bai, R B; Neoh, K G; Ting, Y P; Kang, E T

    2009-01-01

    A novel surface modification technique was developed to provide a copper nickel alloy (M) surface with bactericidal and anticorrosion properties for inhibiting biocorrosion. 4-(chloromethyl)-phenyl tricholorosilane (CTS) was first coupled to the hydroxylated alloy surface to form a compact silane layer, as well as to confer the surface with chloromethyl functional groups. The latter allowed the coupling of 4-vinylpyridine (4VP) to generate the M-CTS-4VP surface with biocidal functionality. Subsequent surface graft polymerization of 4VP, in the presence of benzoyl peroxide (BPO) initiator, from the M-CTS-4VP surface produced the poly(4-vinylpyridine) (P(4VP)) grafted surface, or the M-CTS-P(4VP) surface. The pyridine nitrogen moieties on the M-CTS-P(4VP) surface were quaternized with hexylbromide to produce a high concentration of quaternary ammonium groups. Each surface functionalization step was ascertained by X-ray photoelectron spectroscopy (XPS) and static water contact angle measurements. The alloy with surface-quaternized pyridinium cation groups (N+) exhibited good bactericidal efficiency in a Desulfovibrio desulfuricans-inoculated seawater-based modified Barr's medium, as indicated by viable cell counts and fluorescence microscopy (FM) images of the surface. The anticorrosion capability of the organic layers was verified by the polarization curve and electrochemical impedance spectroscopy (EIS) measurements. In comparison, the pristine (surface hydroxylated) Cu-Ni alloy was found to be readily susceptible to biocorrosion under the same environment.

  12. The role of ecological theory in microbial ecology.

    Science.gov (United States)

    Prosser, James I; Bohannan, Brendan J M; Curtis, Tom P; Ellis, Richard J; Firestone, Mary K; Freckleton, Rob P; Green, Jessica L; Green, Laura E; Killham, Ken; Lennon, Jack J; Osborn, A Mark; Solan, Martin; van der Gast, Christopher J; Young, J Peter W

    2007-05-01

    Microbial ecology is currently undergoing a revolution, with repercussions spreading throughout microbiology, ecology and ecosystem science. The rapid accumulation of molecular data is uncovering vast diversity, abundant uncultivated microbial groups and novel microbial functions. This accumulation of data requires the application of theory to provide organization, structure, mechanistic insight and, ultimately, predictive power that is of practical value, but the application of theory in microbial ecology is currently very limited. Here we argue that the full potential of the ongoing revolution will not be realized if research is not directed and driven by theory, and that the generality of established ecological theory must be tested using microbial systems.

  13. Insights into the Mechanism of Action of Bactericidal Lipophosphonoxins.

    Directory of Open Access Journals (Sweden)

    Natalya Panova

    Full Text Available The advantages offered by established antibiotics in the treatment of infectious diseases are endangered due to the increase in the number of antibiotic-resistant bacterial strains. This leads to a need for new antibacterial compounds. Recently, we discovered a series of compounds termed lipophosphonoxins (LPPOs that exhibit selective cytotoxicity towards Gram-positive bacteria that include pathogens and resistant strains. For further development of these compounds, it was necessary to identify the mechanism of their action and characterize their interaction with eukaryotic cells/organisms in more detail. Here, we show that at their bactericidal concentrations LPPOs localize to the plasmatic membrane in bacteria but not in eukaryotes. In an in vitro system we demonstrate that LPPOs create pores in the membrane. This provides an explanation of their action in vivo where they cause serious damage of the cellular membrane, efflux of the cytosol, and cell disintegration. Further, we show that (i LPPOs are not genotoxic as determined by the Ames test, (ii do not cross a monolayer of Caco-2 cells, suggesting they are unable of transepithelial transport, (iii are well tolerated by living mice when administered orally but not peritoneally, and (iv are stable at low pH, indicating they could survive the acidic environment in the stomach. Finally, using one of the most potent LPPOs, we attempted and failed to select resistant strains against this compound while we were able to readily select resistant strains against a known antibiotic, rifampicin. In summary, LPPOs represent a new class of compounds with a potential for development as antibacterial agents for topical applications and perhaps also for treatment of gastrointestinal infections.

  14. Insights into the Mechanism of Action of Bactericidal Lipophosphonoxins.

    Science.gov (United States)

    Panova, Natalya; Zborníková, Eva; Šimák, Ondřej; Pohl, Radek; Kolář, Milan; Bogdanová, Kateřina; Večeřová, Renata; Seydlová, Gabriela; Fišer, Radovan; Hadravová, Romana; Šanderová, Hana; Vítovská, Dragana; Šiková, Michaela; Látal, Tomáš; Lovecká, Petra; Barvík, Ivan; Krásný, Libor; Rejman, Dominik

    2015-01-01

    The advantages offered by established antibiotics in the treatment of infectious diseases are endangered due to the increase in the number of antibiotic-resistant bacterial strains. This leads to a need for new antibacterial compounds. Recently, we discovered a series of compounds termed lipophosphonoxins (LPPOs) that exhibit selective cytotoxicity towards Gram-positive bacteria that include pathogens and resistant strains. For further development of these compounds, it was necessary to identify the mechanism of their action and characterize their interaction with eukaryotic cells/organisms in more detail. Here, we show that at their bactericidal concentrations LPPOs localize to the plasmatic membrane in bacteria but not in eukaryotes. In an in vitro system we demonstrate that LPPOs create pores in the membrane. This provides an explanation of their action in vivo where they cause serious damage of the cellular membrane, efflux of the cytosol, and cell disintegration. Further, we show that (i) LPPOs are not genotoxic as determined by the Ames test, (ii) do not cross a monolayer of Caco-2 cells, suggesting they are unable of transepithelial transport, (iii) are well tolerated by living mice when administered orally but not peritoneally, and (iv) are stable at low pH, indicating they could survive the acidic environment in the stomach. Finally, using one of the most potent LPPOs, we attempted and failed to select resistant strains against this compound while we were able to readily select resistant strains against a known antibiotic, rifampicin. In summary, LPPOs represent a new class of compounds with a potential for development as antibacterial agents for topical applications and perhaps also for treatment of gastrointestinal infections.

  15. Ecological optimization and performance study of irreversible Stirling and Ericsson heat engines

    International Nuclear Information System (INIS)

    Tyagi, S K; Kaushik, S C; Salhotra, R

    2002-01-01

    The concept of finite time thermodynamics is used to determine the ecological function of irreversible Stirling and Ericsson heat engine cycles. The ecological function is defined as the power output minus power loss (irreversibility), which is the ambient temperature times, the entropy generation rate. The ecological function is maximized with respect to cycle temperature ratio and the expressions for the corresponding power output and thermal efficiency are derived at the optimal operating conditions. The effect of different operating parameters, the effectiveness on the hot, cold and the regenerative side heat exchangers, the cycle temperature ratio, heat capacitance ratio and the internal irreversibility parameter on the maximum ecological function are studied. It is found that the effect of regenerator effectiveness is more than the hot and cold side heat exchangers and the effect of the effectiveness on cold side heat exchanger is more than the effectiveness on the hot side heat exchanger on the maximum ecological function. It is also found that the effect of internal irreversibility parameter is more than the other parameters not only on the maximum ecological function but also on the corresponding power output and the thermal efficiency

  16. Ecological optimization and performance study of irreversible Stirling and Ericsson heat engines

    Science.gov (United States)

    Tyagi, S. K.; Kaushik, S. C.; Salhotra, R.

    2002-10-01

    The concept of finite time thermodynamics is used to determine the ecological function of irreversible Stirling and Ericsson heat engine cycles. The ecological function is defined as the power output minus power loss (irreversibility), which is the ambient temperature times, the entropy generation rate. The ecological function is maximized with respect to cycle temperature ratio and the expressions for the corresponding power output and thermal efficiency are derived at the optimal operating conditions. The effect of different operating parameters, the effectiveness on the hot, cold and the regenerative side heat exchangers, the cycle temperature ratio, heat capacitance ratio and the internal irreversibility parameter on the maximum ecological function are studied. It is found that the effect of regenerator effectiveness is more than the hot and cold side heat exchangers and the effect of the effectiveness on cold side heat exchanger is more than the effectiveness on the hot side heat exchanger on the maximum ecological function. It is also found that the effect of internal irreversibility parameter is more than the other parameters not only on the maximum ecological function but also on the corresponding power output and the thermal efficiency.

  17. The ecological economics: An ecological economics

    International Nuclear Information System (INIS)

    Castiblanco R, Carmenza

    2007-01-01

    Ecological Economics arise as a scientific discipline aimed to integrate concepts of economics, ecology, thermodynamics, ethic and other natural and social sciences in order to incorporate a biophysical and integrated perspective of the inter dependences between economies and environment, from a plural conception and a methodology beyond disciplines. Ecological Economics studies the black box of economic processes usually excluded of the traditional economics: thermodynamics and ecology. Although it is relatively a new field of study, it has been strengthening its theoretical framework with scientific basis and analytic principles that lead to its identification as a new discipline that show a whole new paradigm. The scope of this article is to show the conceptual and methodological bases, the main founders, approaches and central debates of this new discipline. This brief introduction is a preamble to the papers of the meeting Ecological Economics: a perspective for Colombia included in this number, that took place on September 22 - 27 of 2007, at the National University of Colombia at Bogota. During tree days national and international experts, professors, researchers, workers of environmental sector and people interested on environmental issues joined together to know the conceptual and methodological achievements reached of this discipline; as well as to analyse and evaluate the environmental problems of the country, from the systemic, interdisciplinary and general perspective that it promotes

  18. Effect of dissolved humic acid on the Pb bioavailability in soil solution and its consequence on ecological risk.

    Science.gov (United States)

    An, Jinsung; Jho, Eun Hea; Nam, Kyoungphile

    2015-04-09

    Current risk characterization in ecological risk assessment does not consider bioavailability of heavy metals, which highly depends on physicochemical properties of environmental media. This study was set to investigate the effect of humic acid (HA), used as a surrogate of organic matter, on Pb toxicity and the subsequent effect on risk characterization in ecological risk assessment. Pb toxicity was assessed using Microtox(®) in the presence and absence of two different forms of HA, particulate HA (pHA) and dissolved HA (dHA). With increasing contact time, the EC10 values increased (i.e., the toxic effects decreased) and the dissolved Pb concentrations of the filtrates decreased. The high correlation (R = 0.88, p < 0.001) between toxic effects determined using both the mixture and its filtrate as exposure media leads us to conclude that the Pb toxicity highly depends on the soluble fraction. Also, reduced Pb toxicity with increasing dHA concentrations, probably due to formation of Pb-dHA complexes, indicated that Pb toxicity largely comes from free Pb ions. Overall, this study shows the effect of HA on metal toxicity alleviation, and emphasizes the need for incorporating the bioavailable heavy metal concentrations in environmental media as a point of exposure in ecological risk assessment. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. How about food irradiation? Its history and usefulness. (3) Irradiation effects on food and decrease in fungi

    International Nuclear Information System (INIS)

    Ito, Hitoshi

    2006-01-01

    Inhibiting germination of vegetables and grade control of maturity of fruits, destroy of insect pest and parasite, disinfection of meats and fishes, bactericidal action of dry foods such as spices, and taste and color change of irradiated foods and perfect bactericidal action are stated. Application of food irradiation contains inhibiting germination, insecticidal action, sterilization of insect pest, grade control of maturity, inhibition of food poisoning, decrease in fungi, improvement of properties, and perfect bactericidal action. Each treatment of foods is described by the effects of three exposure doses such as the low exposure dose until 1 kGy, middle exposure dose from 1 to 10 kGy and high from 10 to 75 kGy. (S.Y.)

  20. Linking effects of anthropogenic debris to ecological impacts

    NARCIS (Netherlands)

    Browne, M.A.; Underwood, A.J.; Chapman, M.G.; Williams, R.; Thompson, R.C.; Franeker, van J.A.

    2015-01-01

    Accelerated contamination of habitats with debris has caused increased effort to determine ecological impacts. Strikingly, most work on organisms focuses on sublethal responses to plastic debris. This is controversial because (i) researchers have ignored medical insights about the mechanisms that

  1. Ecological research at the Savannah River Ecology Laboratory. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-05-01

    Research is organized around two major programs: thermal and aquatic stress and mineral cycling. These programs are strengthened by a previously established foundation of basic ecological knowledge. Research in basic ecology continues to be a major component of all SREL environmental programs. Emphasis in all programs has been placed upon field-oriented research relating to regional and local problems having broad ecological significance. For example, extensive research has been conducted in the Par Pond reservoir system and the Savannah River swamp, both of which have received thermal effluent, heavy metals, and low levels of radioisotopes. Furthermore, the availability of low levels of plutonium and uranium in both terrestrial and aquatic environments on the Savannah River Plant (SRP) has provided an unusual opportunity for field research in this area. The studies seek to document the effects, to determine the extent of local environmental problems, and to establish predictable relationships which have general applicability. In order to accomplish this objective it has been imperative that studies be carried out in the natural, environmentally unaffected areas on the SRP as a vital part of the overall program. Progress is reported in forty-nine studies.

  2. Musicking as Education for Social and Ecological Peace: A New Synthesis

    Science.gov (United States)

    Golden, Michael

    2016-01-01

    The aim of this article is twofold: first, to confirm the multi-level linkage between the ecological and social realms in terms of violence, peace, and education, and second, to explore what light ecological thinking can shed on musicking as a potentially effective tool in peace education. The effects of violence in the ecological and social…

  3. Effects of Conceptual Change Text Based Instruction on Ecology, Attitudes toward Biology and Environment

    Science.gov (United States)

    Çetin, Gülcan; Ertepinar, Hamide; Geban, Ömer

    2015-01-01

    The purpose of this study is to investigate the effects of the conceptual change text based instruction on ninth grade students' understanding of ecological concepts, and attitudes toward biology and environment. Participants were 82 ninth grade students in a public high school in the Northwestern Turkey. A treatment was employed over a five-week…

  4. Microbicidal effects of plain soap vs triclocarban-based antibacterial soap.

    Science.gov (United States)

    Kim, S A; Rhee, M S

    2016-11-01

    The aim of this study was to determine the bactericidal effects of plain and antibacterial soap. The bactericidal effects of plain and antibacterial soap containing 0.3% triclocarban were examined against 10 Gram-positive and 10 Gram-negative bacterial strains after exposure at 22°C and 40°C for 20 s. Gram-negative bacteria were more susceptible to both soaps than Gram-positive bacteria. However, with one exception (Enterococcus faecalis ATCC 19433 at 40°C), there was no significant difference between the effects of medicated and non-medicated soap at either temperature. Triclocarban in soap does not lead to a meaningful reduction in bacterial levels during use. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  5. Ecologies of Learning, Ecologies of Creativity

    DEFF Research Database (Denmark)

    Høyrup, Helene

    in the light of the new Danish school reform. How can different learning institutions contribute to a “joint” ecology of learning? What would the benefits be from this in terms of young people’s literacies? On what theoretical basis can such an ecology and co-creation take place? And what kind of didactics...

  6. [Regional ecological planning and ecological network construction: a case study of "Ji Triangle" Region].

    Science.gov (United States)

    Li, Bo; Han, Zeng-Lin; Tong, Lian-Jun

    2009-05-01

    By the methods of in situ investigation and regional ecological planning, the present ecological environment, ecosystem vulnerability, and ecological environment sensitivity in "Ji Triangle" Region were analyzed, and the ecological network of the study area was constructed. According to the ecological resources abundance degree, ecological recovery, farmland windbreak system, environmental carrying capacity, forestry foundation, and ecosystem integrity, the study area was classified into three regional ecological function ecosystems, i. e., east low hill ecosystem, middle plain ecosystem, and west plain wetland ecosystem. On the basis of marking regional ecological nodes, the regional ecological corridor (Haerbin-Dalian regional axis, Changchun-Jilin, Changchun-Songyuan, Jilin-Songyuan, Jilin-Siping, and Songyuan-Siping transportation corridor) and regional ecological network (one ring, three links, and three belts) were constructed. Taking the requests of regional ecological security into consideration, the ecological environment security system of "Ji Triangle" Region, including regional ecological conservation district, regional ecological restored district, and regional ecological management district, was built.

  7. Civic Ecology: A Postmodern Approach to Ecological Sustainability

    Science.gov (United States)

    Lopes, V. L.

    2013-12-01

    Human agency is transforming the planetary processes at unprecedented rates risking damaging essential life-support systems. Climate change, massive species extinction, land degradation, resources depletion, overpopulation, poverty and social injustice are all the result of human choices and non-sustainable ways of life. The survival of our modern economic systems depends upon insatiable consumption - a simple way of life no longer satisfies most people. Detached, instrumental rationality has created an ideal of liberalism based on individual pursuit of self-interest, leading the way into unprecedented material progress but bringing with it human alienation, social injustice, and ecological degradation. The purpose of this presentation is to introduce a community-based systems response to a growing sense that the interlocked social-ecological crisis is as much a problem of human thought and behavior as it is about identifying carrying capacities and CO2 concentrations in the atmosphere. This approach, referred to here as civic ecology, presents a new and important paradigm shift in sustainability practice that attempts to bring together and integrate ecological ideas and postmodern thinking. As such, it is as much a holistic, dynamic, and synergistic approach to ecological sustainability, as it is a philosophy of life and ethical perspective born of ecological understanding and insight. Civic ecology starts with the proposition that the key factor determining the health of the ecosphere is the behavior of human beings, and therefore many of the most important issues related to sustainability lie in the areas of human thought and culture. Thus, the quest for sustainability must include as a central concern the transformation of psychological and behavioral patterns that have become an imminent danger to planetary health. At the core of this understanding is a fundamental paradigm shift from the basic commitments of modern Western culture to its model of mechanism

  8. Effects of Mulching Mode on Canopy Physiological, Ecological Characteristics and Yield of Upland Rice

    OpenAIRE

    Yu-zhu ZHANG; Yang LIU; Xiang ZENG; Kai-lin CHEN; Ze-hui HUANG; Hong-ke XIE

    2011-01-01

    The effects of mulching mode on population physiology and ecology of rice were studied using a combination P88S/1128 as the material under three mulching cultivation modes including plastic film mulching, straw mulching and liquid film mulching, as well as bare cultivation (control). The results indicated that mulching mode had significant effects on micro-meteorological factors and individual growth of rice, as shown by an increase of relative humidity, a better internal micro-meteorological...

  9. Ecological impacts of umbrella effects of radiation on the individual members

    International Nuclear Information System (INIS)

    Doi, Masahiro; Kawaguchi, Isao

    2007-01-01

    In order to study the interactions in a model aquatic microcosm, an individual-based computer simulation model was developed. The microcosm consists of Euglena gracilis as an autotroph algae, Tetrahymena thermophila as a heterotroph protozoa and Escherichia coli as a saprotroph bacteria. There exists a strong interaction between Tetrahymena and E. coli as the first is the predator of the second. Ecological toxicity tests were conducted to test the population level impacts of the biological effects of radiation and toxicants on the lethality and mobility factors that influence directly or indirectly growth and reproduction. Radiological effects on lethality of E. coli individuals were translated to the reduction of the equilibrium population of Tetrahymena. A synergistic effect at the community level was also observed by the simulation of a combined exposure of radiation and a toxicant which reduced the feeding efficiency of Tetrahymena

  10. Socio-ecological impact of development schemes in the homelands of South Africa

    Energy Technology Data Exchange (ETDEWEB)

    de Wet, C. (Rhodes Univ., Grahamstown (South Africa))

    Development schemes in rural areas have a significant ecological impact as they often involve a reorganization of land-use and resource-utilization patterns. This reorganization is usually intended to have a positive ecological effect by combating erosion, promoting rational land-use patterns and using the potential of the area to best effect, thereby also providing economic benefits to the people living there. Often development schemes have the opposite effect - a negative ecological and economic impact as well as causing considerable social disruption, which in its turn has further negative ecological consequences. This paper looks at several kinds of development projects, seeking to understand why they have limited rather than increased ecological, economic and social options, and to what extent such negative effects can be avoided in future development projects in rural areas.

  11. Introduction to the Special Volume on "Ecology and Ecological Modeling in R"

    OpenAIRE

    Kneib, Thomas; Petzoldt, Thomas

    2007-01-01

    The third special volume in the "Foometrics in R" series of the Journal of Statistical Software collects a number of contributions describing statistical methodology and corresponding implementations related to ecology and ecological modelling. The scope of the papers ranges from theoretical ecology and ecological modelling to statistical methodology relevant for data analyses in ecological applications.

  12. FFI: A software tool for ecological monitoring

    Science.gov (United States)

    Duncan C. Lutes; Nathan C. Benson; MaryBeth Keifer; John F. Caratti; S. Austin Streetman

    2009-01-01

    A new monitoring tool called FFI (FEAT/FIREMON Integrated) has been developed to assist managers with collection, storage and analysis of ecological information. The tool was developed through the complementary integration of two fire effects monitoring systems commonly used in the United States: FIREMON and the Fire Ecology Assessment Tool. FFI provides software...

  13. Ecological support for rural land-use planning.

    Science.gov (United States)

    David M. Theobald; Thomas Spies; Jeff Kline; Bruce Maxwell; N. T. Hobbs; Virginia H. Dale

    2005-01-01

    How can ecologists be more effective in supporting ecologically informed rural land-use planning and policy? Improved decision making about rural lands requires careful consideration of how ecological information and analyses can inform specific planning and policy needs. We provide a brief overview of rural land-use planning, including recently developed approaches to...

  14. Selected bibliography of terrestrial freshwater, and marine radiation ecology

    International Nuclear Information System (INIS)

    Schultz, V.; Whicker, F.W.

    1975-01-01

    An extensive bibliography is presented of publications related to field or laboratory studies of wild species of plants and animals with respect to radiation effects or metabolic studies involving radionuclides. The references are listed under the following headings: status and needs of radiation ecology; environmental radioactivity; radionuclide concentration; ionizing radiation effects; techniques utilizing radionuclides and ionizing radiation in ecology; measurement of ionizing radiation; peaceful uses of atomic energy; waste disposal; nuclear testing and ecological consequences of a nuclear war; glossaries, standards, and licensing procedures; reviews of radionuclides in the environment; and sources of information

  15. Taiwan’s Ecological Footprint (1994–2011

    Directory of Open Access Journals (Sweden)

    Yung-Jaan Lee

    2014-09-01

    Full Text Available According to the 2011 edition of the National Footprint Accounts (NFA published by the Global Footprint Network (GFN, humankind consumed the resources and services of 1.5 planets in 2008; the corresponding number in 1961 was 0.7 planets. North Americans have an ecological footprint of 8.7 global hectares per person whereas Africans have a footprint of only 1.4 global hectares per person. The global mean biological capacity is only 1.8 global hectares per person so human beings are overshooting ecological resources. The ecological footprint measures the resources that are consumed by humans from the biosphere, and serves as an index of the sustainability of development. The NFA includes the ecological footprints of over 200 countries and regions, but not Taiwan. Hence, Taiwan must establish and update its own ecological footprint databases. Ecological footprint is one indicator of the sustainability of development, and can be compared across nations. This study extends previous studies by analyzing Taiwan’s ecological footprint from 2008–2011. With reference to the ecological footprint accounts of the Global Footprint Network and the Taiwan’s ecological footprint analysis for 1997–2007, this study presents Taiwan’s ecological footprint from 2008–2011. Most of the data that are used herein are taken from the Food and Agriculture Organization, the International Energy Agency, Taiwan’s Council of Agriculture and Taiwan’s National Development Council. The results thus obtained reveal that Taiwan’s ecological footprint from 2008–2011 exceeded that from 1997–2007. To respond to this trend toward un-sustainable development and to help Taiwan move toward sustainability, carbon reduction and energy saving policies should be implemented to effectively manage Taiwan’s ecological resources.

  16. Ecological forestry in the Southeast: Understanding the ecology of fuels

    Science.gov (United States)

    R.J. Mitchell; J.K. Hiers; J. O’Brien; G. Starr

    2009-01-01

    Fire is a dominant disturbance within many forested ecosystems worldwide. Understanding the complex feedbacks among vegetation as a fuel for fire, the effects of fuels on fire behavior, and the impact of fire behavior on future vegetation are critical for sustaining biodiversity in fire-dependent forests. Nonetheless, understanding in fire ecology has been limited in...

  17. Current problems of nuclear power radiation ecology and hygiene

    Energy Technology Data Exchange (ETDEWEB)

    Vorob' ev, E I; Il' in, L A; Knizhnikov, V A; Aleksakhin, R M

    1979-10-01

    Perspectiveness of different kinds of energetics is mainly defined by their effect on environment and human health. Hygiene and ecology at present time can not give an objective characteristic of detriment because of the effluents from the fuel-energy cycle facilities, especially from facilities of the traditional energetics. The role of the radiactive effluents into environment is defined by their possible effect on the human health, but not the ecological effects. Meanwhile, the development of the principles of ecological normalization is an actual problem. It is important to carry out a quantitative stady of the dose-effect dependencies of the effluents of cancerogens of the physical and chemical nature into environment. It is advisable to estimate the possible effect of cancerogens from the positions of thresholdlessness of their action.

  18. Current problems of nuclear power radiation ecology and hygiene

    International Nuclear Information System (INIS)

    Vorob'ev, E.I.; Il'in, L.A.; Knizhnikov, V.A.; Aleksakhin, R.M.

    1979-01-01

    Perspectiveness of different kinds of energetics is mainly defined by their effect on environment and human health. Hygiene and ecology at present time can not give an objective characteristic of detriment because of the effluents from the fuel-energy cycle facilities, especially from facilities of the traditional energetics. The role of the radiactive effluents into environment is defined by their possible effect on the human health, but not the ecological effects. Meanwhile, the development of the principles of ecological normalization is an actual problem. It is important to carry out a quantitative stady of the dose-effect dependencies of the effluents of cancerogens of the physical and chemical nature into environment. It is advisable to estimate the possible effect of cancerogens from the positions of thresholdlessness of their action

  19. Methodologies for assessment of power plant ecological effects in the marine environment

    International Nuclear Information System (INIS)

    Adams, S.M.

    1978-01-01

    Various types of models or methodologies relevant to the assessment of entrainment, thermal, and impingement impacts of power plant operation in the marine environment are presented. The majority of methodologies available for assessing power plant effects are focused at the organism or population level. The most widely applied approaches for estimating entrainment effects on fish populations are the equivalent adult and trophic-conversion methodologies. Current methods to predict the number of fish and distribution of species impinged consider physical factors of the environment but not the biological or behavorial characteristics of fish. With proper validation, ecosystem-level models that consider aggregate responses of biological components to stress may prove to be a viable approach for investigating power plant ecological effects

  20. Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host-parasite interactions.

    Science.gov (United States)

    Tao, Leiling; Gowler, Camden D; Ahmad, Aamina; Hunter, Mark D; de Roode, Jacobus C

    2015-10-22

    Host-parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host-parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host-parasite systems. © 2015 The Author(s).

  1. Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host–parasite interactions

    Science.gov (United States)

    Tao, Leiling; Gowler, Camden D.; Ahmad, Aamina; Hunter, Mark D.; de Roode, Jacobus C.

    2015-01-01

    Host–parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host–parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host–parasite systems. PMID:26468247

  2. Recombinant Protein Truncation Strategy for Inducing Bactericidal Antibodies to the Macrophage Infectivity Potentiator Protein of Neisseria meningitidis and Circumventing Potential Cross-Reactivity with Human FK506-Binding Proteins

    Science.gov (United States)

    Bielecka, Magdalena K.; Devos, Nathalie; Gilbert, Mélanie; Hung, Miao-Chiu; Weynants, Vincent; Heckels, John E.

    2014-01-01

    A recombinant macrophage infectivity potentiator (rMIP) protein of Neisseria meningitidis induces significant serum bactericidal antibody production in mice and is a candidate meningococcal vaccine antigen. However, bioinformatics analysis of MIP showed some amino acid sequence similarity to human FK506-binding proteins (FKBPs) in residues 166 to 252 located in the globular domain of the protein. To circumvent the potential concern over generating antibodies that could recognize human proteins, we immunized mice with recombinant truncated type I rMIP proteins that lacked the globular domain and the signal leader peptide (LP) signal sequence (amino acids 1 to 22) and contained the His purification tag at either the N or C terminus (C-term). The immunogenicity of truncated rMIP proteins was compared to that of full (i.e., full-length) rMIP proteins (containing the globular domain) with either an N- or C-terminal His tag and with or without the LP sequence. By comparing the functional murine antibody responses to these various constructs, we determined that C-term His truncated rMIP (−LP) delivered in liposomes induced high levels of antibodies that bound to the surface of wild-type but not Δmip mutant meningococci and showed bactericidal activity against homologous type I MIP (median titers of 128 to 256) and heterologous type II and III (median titers of 256 to 512) strains, thereby providing at least 82% serogroup B strain coverage. In contrast, in constructs lacking the LP, placement of the His tag at the N terminus appeared to abrogate bactericidal activity. The strategy used in this study would obviate any potential concerns regarding the use of MIP antigens for inclusion in bacterial vaccines. PMID:25452551

  3. Recombinant protein truncation strategy for inducing bactericidal antibodies to the macrophage infectivity potentiator protein of Neisseria meningitidis and circumventing potential cross-reactivity with human FK506-binding proteins.

    Science.gov (United States)

    Bielecka, Magdalena K; Devos, Nathalie; Gilbert, Mélanie; Hung, Miao-Chiu; Weynants, Vincent; Heckels, John E; Christodoulides, Myron

    2015-02-01

    A recombinant macrophage infectivity potentiator (rMIP) protein of Neisseria meningitidis induces significant serum bactericidal antibody production in mice and is a candidate meningococcal vaccine antigen. However, bioinformatics analysis of MIP showed some amino acid sequence similarity to human FK506-binding proteins (FKBPs) in residues 166 to 252 located in the globular domain of the protein. To circumvent the potential concern over generating antibodies that could recognize human proteins, we immunized mice with recombinant truncated type I rMIP proteins that lacked the globular domain and the signal leader peptide (LP) signal sequence (amino acids 1 to 22) and contained the His purification tag at either the N or C terminus (C-term). The immunogenicity of truncated rMIP proteins was compared to that of full (i.e., full-length) rMIP proteins (containing the globular domain) with either an N- or C-terminal His tag and with or without the LP sequence. By comparing the functional murine antibody responses to these various constructs, we determined that C-term His truncated rMIP (-LP) delivered in liposomes induced high levels of antibodies that bound to the surface of wild-type but not Δmip mutant meningococci and showed bactericidal activity against homologous type I MIP (median titers of 128 to 256) and heterologous type II and III (median titers of 256 to 512) strains, thereby providing at least 82% serogroup B strain coverage. In contrast, in constructs lacking the LP, placement of the His tag at the N terminus appeared to abrogate bactericidal activity. The strategy used in this study would obviate any potential concerns regarding the use of MIP antigens for inclusion in bacterial vaccines. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. Spatial variation in the flux of atmospheric deposition and its ecological effects in arid Asia

    Science.gov (United States)

    Jiao, Linlin; Wang, Xunming; Li, Danfeng

    2018-06-01

    Atmospheric deposition is one of the key land surface processes, and plays important roles in regional ecosystems and global climate change. Previous studies have focused on the magnitude of and the temporal and spatial variations in the flux of atmospheric deposition, and the composition of atmospheric deposition on a local scale. However, there have been no comprehensive studies of atmospheric deposition on a regional scale and its ecological effects in arid Asia. The temporal and spatial patterns, composition of atmospheric deposition, and its potential effects on regional ecosystems in arid Asia are investigated in this study. The results show that the annual deposition flux is high on the Turan Plain, Aral Sea Desert, and Tarim Basin. The seasonal deposition flux also varies remarkably among different regions. The Tarim Basin shows higher deposition flux in both spring and summer, southern Mongolian Plateau has a higher deposition flux in spring, and the deposition flux of Iran Plateau is higher in summer. Multiple sources of elements in deposited particles are identified. Calcium, iron, aluminum, and magnesium are mainly derived from remote regions, while zinc, copper and lead have predominantly anthropogenic sources. Atmospheric deposition can provide abundant nutrients to vegetation and consequently play a role in the succession of regional ecosystems by affecting the structure, function, diversity, and primary production of the vegetation, especially the exotic or short-lived opportunistic species in arid Asia. Nevertheless, there is not much evidence of the ecological effects of atmospheric deposition on the regional and local scale. The present results may help in further understanding the mechanism of atmospheric deposition as well as providing a motivation for the protection of the ecological environment in arid Asia.

  5. Ecological effects and potential risks of the water diversion project in the Heihe River Basin.

    Science.gov (United States)

    Zhang, Mengmeng; Wang, Shuai; Fu, Bojie; Gao, Guangyao; Shen, Qin

    2018-04-01

    To curb the severe ecological deterioration in the lower Heihe River Basin (HRB) in northwest China, a water diversion project was initiated in 2000. A comprehensive analysis of the ecological effects and potential risks associated with the project is needed. We assessed the hydrological and ecological achievements, and also analyzed the potential problems after the project was completed. We found that since the project began the hydrological regime has changed, with more than 57.82% of the upstream water being discharged to the lower reaches on average. As a result, the groundwater level in the lower reaches has risen; the terminal lake has gradually expanded to a maximum area in excess of 50km 2 since 2010, and there has been a significant recovery of vegetation in the riparian zone and the Ejin core oases, which represents the initial rehabilitation of the degraded downstream environment. Additionally, the economy of Ejin has developed spectacularly, with an annual growth rate of 28.06%. However, in the middle reaches, the average groundwater level has continuously declined by a total of 5.8m and significant degradation of the vegetation has occurred along the river course. The discrepancy in the water allocation between the middle and lower reaches has intensified. This highlights the inability of the current water diversion scheme to realize further ecological restoration and achieve sustainable development throughout the whole basin. In future water management programs, we recommend that water allocation is coordinated by considering the basin as an integrated entity and to scientifically determine the size of the midstream farmland and downstream oasis; restrict non-ecological water use in the lower reaches, and jointly dispatch the surface water and groundwater. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A review of ecological effects and environmental fate of illicit drugs in aquatic ecosystems.

    Science.gov (United States)

    Rosi-Marshall, E J; Snow, D; Bartelt-Hunt, S L; Paspalof, A; Tank, J L

    2015-01-23

    Although illicit drugs are detected in surface waters throughout the world, their environmental fate and ecological effects are not well understood. Many illicit drugs and their breakdown products have been detected in surface waters and temporal and spatial variability in use translates into "hot spots and hot moments" of occurrence. Illicit drug occurrence in regions of production and use and areas with insufficient wastewater treatment are not well studied and should be targeted for further study. Evidence suggests that illicit drugs may not be persistent, as their half-lives are relatively short, but may exhibit "pseudo-persistence" wherein continual use results in persistent occurrence. We reviewed the literature on the ecological effects of these compounds on aquatic organisms and although research is limited, a wide array of aquatic organisms, including bacteria, algae, invertebrates, and fishes, have receptors that make them potentially sensitive to these compounds. In summary, illicit drugs occur in surface waters and aquatic organisms may be affected by these compounds; research is needed that focuses on concentrations of illicit drugs in areas of production and high use, environmental fate of these compounds, and effects of these compounds on aquatic ecosystems at the concentrations that typically occur in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Ecological behavior and effects of energy related pollutants. Progress report, June 1976--August 1977

    International Nuclear Information System (INIS)

    Platt, R.B.; Ragsdale, H.L.; Murdy, W.H.; Shure, D.J.

    1977-01-01

    The impact of SO 2 on the survival and stability of plant populations and communities was studied. The results to date have an important bearing on the adequacy of current permissible ambient air levels for SO 2 . Atmospheric SO 2 concentrations at near permissible levels had a significant adverse effect on sexual reproduction processes, which results in a reduced number of viable seeds, in all 8 populations tested. Implications for both natural and agricultural plant species and possible significant losses of fruit production are discussed. An ecological implication of the invisible effect of fruit and seed mortality is postulated since the life cycle of many insects and the trophic relations of numerous animals depend, at least in part, on fruit production by trees and shrubs. Hence, there is a potential for disruptive effects on ecosystem level processes. Results are also reported from four systems-oriented studies within the Lower Three Runs Creek Watershed, Savannah River Plant, to examine fallout 137 Cs transfer processes in ecological systems characteristic of the Southeastern Coastal Plain. These studies were carried out within the stream and its floodplains, within floodplains along the stream gradient, in upland aquatic systems (Carolina Bays), and in the upland scrub-oak forest system. Results are discussed

  8. Effectiveness of teams: Lessons from biomimicry, an ecological inquiry E=MC

    Directory of Open Access Journals (Sweden)

    Sivave Mashingaidze

    2015-07-01

    Full Text Available Team effectiveness in swarms like bees, colonies of ants, schools of fish, flocks of birds, and fireflies flashing synchronously are all as a result of highly coordinated behaviors that emerge from collective, decentralized intelligence. The purpose of this article was to conduct an ecological research inquiry of what lessons business can borrow from biomimicry especially by studying ants’ colonies, swarm of bees and packs of wild African dogs. A systems science theory borrowed from Albeit Einstein E = mc2 was used, where effectiveness of teams was equal to mastery of each individual x coordination x communication (collective intelligence. The author used using secondary data analysis to obtain information on team effectiveness and collective intelligence. The research found out that, team effectiveness is a function of mastery of individual x coordination x communication (collective intelligence. The research further recommended corporate to mimic the biosphere especially to adopt collective intelligence strategies from ants, swarm of bees and wild dogs for business sustainability

  9. Philosophy of ecology

    CERN Document Server

    Brown, Bryson; Peacock, Kent A

    2011-01-01

    The most pressing problems facing humanity today - over-population, energy shortages, climate change, soil erosion, species extinctions, the risk of epidemic disease, the threat of warfare that could destroy all the hard-won gains of civilization, and even the recent fibrillations of the stock market - are all ecological or have a large ecological component. in this volume philosophers turn their attention to understanding the science of ecology and its huge implications for the human project. To get the application of ecology to policy or other practical concerns right, humanity needs a clear and disinterested philosophical understanding of ecology which can help identify the practical lessons of science. Conversely, the urgent practical demands humanity faces today cannot help but direct scientific and philosophical investigation toward the basis of those ecological challenges that threaten human survival. This book will help to fuel the timely renaissance of interest in philosophy of ecology that is now oc...

  10. Introduction. Antarctic ecology: from genes to ecosystems. Part 2. Evolution, diversity and functional ecology.

    Science.gov (United States)

    Rogers, Alex D; Murphy, Eugene J; Johnston, Nadine M; Clarke, Andrew

    2007-12-29

    The Antarctic biota has evolved over the last 100 million years in increasingly isolated and cold conditions. As a result, Antarctic species, from micro-organisms to vertebrates, have adapted to life at extremely low temperatures, including changes in the genome, physiology and ecological traits such as life history. Coupled with cycles of glaciation that have promoted speciation in the Antarctic, this has led to a unique biota in terms of biogeography, patterns of species distribution and endemism. Specialization in the Antarctic biota has led to trade-offs in many ecologically important functions and Antarctic species may have a limited capacity to adapt to present climate change. These include the direct effects of changes in environmental parameters and indirect effects of increased competition and predation resulting from altered life histories of Antarctic species and the impacts of invasive species. Ultimately, climate change may alter the responses of Antarctic ecosystems to harvesting from humans. The unique adaptations of Antarctic species mean that they provide unique models of molecular evolution in natural populations. The simplicity of Antarctic communities, especially from terrestrial systems, makes them ideal to investigate the ecological implications of climate change, which are difficult to identify in more complex systems.

  11. Preparation of Ag/TiO{sub 2}/SiO{sub 2} films via photo-assisted deposition and adsorptive self-assembly for catalytic bactericidal application

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Baojuan, E-mail: baojuanxi@gmail.com [Department of Electrical and Computer Engineering, 10 Kent Ridge Crescent, Singapore 119260 (Singapore); Chu, Xiaona; Hu, Jiangyong [Department of Civil and Environmental Engineering, 10 Kent Ridge Crescent, Singapore 119260 (Singapore); Bhatia, Charanjit Singh; Danner, Aaron James; Yang, Hyunsoo [Department of Electrical and Computer Engineering, 10 Kent Ridge Crescent, Singapore 119260 (Singapore)

    2014-08-30

    Highlights: • We prepared controlledly the silver nanoparticles on TiO{sub 2}/SiO{sub 2} film by the facile photoreduction under the aid of structure-directing agents. • We studied the effect of silver loading on the antibactierial behavior of TiO{sub 2} film and optimized the content of silver. • We extended the route to fabricate other metals on substrates. - Abstract: The deterioration of water supply quality due to the waterborne bacteria is an environmental problem requiring the urgent attention. Due to the excellent and synergic antimicrobial capability, Ag-loaded TiO{sub 2} photocatalyst emerges as a feasible measure to guard the water. In our work, Ag nanoparticles have been prepared by the photoassisted reduction of AgNO{sub 3} on the TiO{sub 2} film fabricated by solution-based adsorptive self-assembly approach. The role of surfactant on the growth rate and size controlling of particles is also studied. In this connection, different kinds of surfactants, such as PVP, Tween-20, Tween-40 and so on, are applied in the system to investigate the formation of Ag nanoparticles. The surface profile and elemental analysis of Ag/TiO{sub 2}/SiO{sub 2} films are examined by scanning electron microscopy and attached energy-dispersive X-ray spectroscopy, respectively. In the anti-bacteria detection, Ag nanoparticles are found to enhance the bactericidal efficiency strongly comparing with the pure TiO{sub 2} film under the same condition. In addition, by comparison with Ag/TiO{sub 2}/SiO{sub 2} film in the dark environment as the reference experiment, UV–visible light plays a vital role in the improved bactericidal behavior, demonstrating the more efficient charge separation induced by metal silver. Because of the versatility of the method, the present photoreductive route is also exploited for the synthesis of Au nanoparticles on TiO{sub 2}/SiO{sub 2} films. The corresponding photocatalytical detection results demonstrate the loading of Au nanoparticles can

  12. Functional genetics of intraspecific ecological interactions in Arabidopsis thaliana.

    Science.gov (United States)

    Wolf, Jason B; Mutic, Joshua J; Kover, Paula X

    2011-05-12

    Studying the genetic basis of traits involved in ecological interactions is a fundamental part of elucidating the connections between evolutionary and ecological processes. Such knowledge allows one to link genetic models of trait evolution with ecological models describing interactions within and between species. Previous work has shown that connections between genetic and ecological processes in Arabidopsis thaliana may be mediated by the fact that quantitative trait loci (QTL) with 'direct' effects on traits of individuals also have pleiotropic 'indirect' effects on traits expressed in neighbouring plants. Here, we further explore these connections by examining functional relationships between traits affected directly and indirectly by the same QTL. We develop a novel approach using structural equation models (SEMs) to determine whether observed pleiotropic effects result from traits directly affected by the QTL in focal individuals causing the changes in the neighbours' phenotypes. This hypothesis was assessed using SEMs to test whether focal plant phenotypes appear to mediate the connection between the focal plants' genotypes and the phenotypes of their neighbours, or alternatively, whether the connection between the focal plants' genotypes and the neighbours' phenotypes is mediated by unmeasured traits. We implement this analysis using a QTL of major effect that maps to the well-characterized flowering locus, FRIGIDA. The SEMs support the hypothesis that the pleiotropic indirect effects of this locus arise from size and developmental timing-related traits in focal plants affecting the expression of developmental traits in their neighbours. Our findings provide empirical insights into the genetics and nature of intraspecific ecological interactions. Our technique holds promise in directing future work into the genetic basis and functional relationship of traits mediating and responding to ecological interactions.

  13. Antibacterial Effect of CrO and CoFe2O4 Nanoparticles upon Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Saber Imani

    2011-12-01

    Full Text Available Background & Objectives: The use of metal oxide nanoparticles can be effective to eliminate the bacterial infections, as an alternative to antibiotics. In this study, antibacterial properties of nonmaterials of CrO and CoFe2O4 are investigated against Staphylococcus aureus as a major and prevalent pathogenic bacterium to achieve sterile nano-containers. Materials & Methods: Different concentrations of CrO and CoFe2O4 nanoparticles, (0.2, 0.4, 0.6, 0.8, and 1% of each, were examined with respect to their optical density (OD culture separately. Different percentages of each nanoparticles were also examined together for the best antibacterial combination. Kinetics of Bactericidal of nanoparticles were calculated in two-hour periods and were compared with the power of other common antibiotics. Ratios of MIC/MBC were calculated by Micro dilution method, to demonstrate the bactericidal power of nanoparticles. Results: The best concentration of the nanoparticles with the highest effect of bactericidal was obtained in the presence of 1% concentration of CrO that the OD of S. aureus culture medium had reduced 4/6 times than the control group (p<0/001.Ratio of 70% CrO to 30% CoFe2O4 was the best of the Bacteriostatic properties that OD was reduced 3/3 times than the control group (p<0/05. Best kinetics of bactericidal with survival rate in the presence of 1% CrO and CoFe2O4 were obtained in 24 and 36 hours respectively. In critical concentration of 1% CrO and CoFe2O4 bactericidal power was about 67 and 56 % respectively. The MIC/MBC rate for CrO and CoFe2O4 was obtained 0/2 and 0/4 respectively. Conclusion: The results showed that CrO nanoparticle compared with CoFe2O4 has a higher bactericidal power for S. aureus infection. Therefore, by completion of these experiments and the use of metal oxide nanoparticles complex in sensitive environments such as food storage containers, etc. are suggested.

  14. World-Ecology and Ireland: The Neoliberal Ecological Regime

    Directory of Open Access Journals (Sweden)

    Sharae Deckard

    2016-03-01

    Full Text Available Since the collapse of the Celtic Tiger, the socio-economic particularity of neoliberal capitalism in its Irish manifestation has increasingly been critiqued, but little attention has been paid to neoliberalism as ecology within Ireland. This article conducts an exploratory survey of the characteristics of the Irish neoliberal ecological regime during and after the Celtic Tiger, identifying the opening of new commodity frontiers (such as fracking, water, agro-biotechnology, and biopharma constituted in the neoliberal drive to appropriate and financialize nature. I argue for the usefulness of applying not only the tools of world-systems analysis, but also Jason W. Moore’s world-ecological paradigm, to analysis of Ireland as a semi-periphery. What is crucial to a macro-ecological understanding of Ireland’s role in the neoliberal regime of the world-ecology is the inextricability of its financial role as a tax haven and secrecy jurisdiction zone from its environmental function as a semi-peripheral pollution and water haven. We can adapt Jason W. Moore’s slogan that “Wall Street…becomes a way of organizing all of nature, characterized by the financialization of any income-generating activity” (Moore 2011b: 39 to say that to say that the “IFSC is a way of organizing nature,” with pernicious consequences for water, energy, and food systems in Ireland. Financial service centers and pharmaceutical factories, plantations and cattle ranches, tax havens and pollution havens, empires and common markets are all forms of environment-making that constellate human relations and extra-human processes into new ecological regimes. More expansive, dialectical understandings of “ecology” as comprising the whole of socio-ecological relations within the capitalist world-ecology—from farming to pharma to financialization—are crucial to forming configurations of knowledge able not only to take account of Ireland’s role in the environmental

  15. Enhanced bactericidal potency of nanoliposomes by modification of the fusion activity between liposomes and bacterium

    Directory of Open Access Journals (Sweden)

    Ma YF

    2013-06-01

    amount of negative charges in fluid liposomes reduces fluid liposomes-bacteria fusion when tested without calcium cations due to electric repulsion, but addition of calcium cations brings the fusion level of fluid liposomes to similar or higher levels. Among the negative phospholipids examined, DMPA gave the highest degree of fusion, DMPS and DMPG had intermediate fusion levels, and PI resulted in the lowest degree of fusion. Furthermore, the fluid liposomal encapsulated tobramycin was prepared, and the bactericidal effect occurred more quickly when bacteria were cultured with liposomal encapsulated tobramycin. Conclusion: The bactericidal potency of fluid liposomes is dramatically enhanced with respect to fusion ability when the fusogenic lipid, DOPE, is included. Regardless of changes in liposome composition, fluid liposomes-bacterium fusion is universally enhanced by calcium ions. The information obtained in this study will increase our understanding of fluid liposomal action mechanisms, and help in optimizing the new generation of fluid liposomal formulations for the treatment of pulmonary bacterial infections. Keywords: liposomes, fusion, bacteria, Pseudomonas aeruginosa, lipid composition

  16. A meningococcal NOMV-FHbp vaccine for Africa elicits broader serum bactericidal antibody responses against serogroup B and non-B strains than a licensed serogroup B vaccine.

    Science.gov (United States)

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

    2016-01-27

    Meningococcal epidemics in Sub-Sahara caused by serogroup A strains are controlled by a group A polysaccharide conjugate vaccine. Strains with serogroups C, W and X continue to cause epidemics. Protein antigens in licensed serogroup B vaccines are shared among serogroup B and non-B strains. Compare serum bactericidal antibody responses elicited by an investigational native outer membrane vesicle vaccine with over-expressed Factor H binding protein (NOMV-FHbp) and a licensed serogroup B vaccine (MenB-4C) against African serogroup A, B, C, W and X strains. Human Factor H (FH) transgenic mice were immunized with NOMV-FHbp prepared from a mutant African meningococcal strain containing genetically attenuated endotoxin and a mutant sub-family B FHbp antigen with low FH binding, or with MenB-4C, which contains a recombinant sub-family B FHbp antigen that binds human FH, and three other antigens, NHba, NadA and PorA P1.4, capable of eliciting bactericidal antibody. The NOMV-FHbp elicited serum bactericidal activity against 12 of 13 serogroup A, B, W or X strains from Africa, and four isogenic serogroup B mutants with sub-family B FHbp sequence variants. There was no activity against a serogroup B mutant with sub-family A FHbp, or two serogroup C isolates from a recent outbreak in Northern Nigeria, which were mismatched for both PorA and sub-family of the FHbp vaccine antigen. For MenB-4C, NHba was expressed by all 16 African isolates tested, FHbp sub-family B in 13, and NadA in five. However, MenB-4C elicited titers ≥ 1:10 against only one isolate, and against only two of four serogroup B mutant strains with sub-family B FHbp sequence variants. NOMV-FHbp has greater potential to confer serogroup-independent protection in Africa than the licensed MenB-4C vaccine. However, the NOMV-FHbp vaccine will require inclusion of sub-family A FHbp for coverage against recent serogroup C strains causing outbreaks in Northern Nigeria. Copyright © 2015 Elsevier Ltd. All rights

  17. Ecological and general systems an introduction to systems ecology

    CERN Document Server

    Odum, Howard T.

    1994-01-01

    Using an energy systems language that combines energetics, kinetics, information, cybernetics, and simulation, Ecological and General Systems compares models of many fields of science, helping to derive general systems principles. First published as Systems Ecology in 1983, Ecological and General Systems proposes principles of self-organization and the designs that prevail by maximizing power and efficiency. Comparisons to fifty other systems languages are provided. Innovative presentations are given on earth homeostasis (Gaia); the inadequacy of presenting equations without network relationships and energy constraints; the alternative interpretation of high entropy complexity as adaptive structure; basic equations of ecological economics; and the energy basis of scientific hierarchy.

  18. Nominal radio ecological benchmarks for the ecological risk assessment of radioactive waste management facilities

    International Nuclear Information System (INIS)

    Garisto, N.C.

    2006-01-01

    Ecological risk assessments are used to assess potential ecological impacts from contaminated sites, such as radioactive waste management and disposal facilities. These assessments determine the overall significance of the impact of such facilities on non-human biota. Specific indicator species are selected as representative non-human biota at the study sites for the purposes of these risk assessments. Potential environmental impacts are generally assessed in terms of 'screening indices'. In simple terms, a screening index is the ratio of an estimated exposure level of the indicator species (or environmental concentration) divided by a level or concentration deemed unlikely to have a significant ecological effect. These latter levels or concentrations are referred to as 'estimated no effect value' or ENEVs. Nominal ENEV values for chronic radiation effects based on our current interpretation of literature data are presented in this paper. They are: 5 mGy/d for fish and amphibians; 2.4 mGy/d for aquatic plants; 2 mGy/d for reptiles; 5 mGy/d for benthic and terrestrial invertebrates; 1 mGy/d for slow-growing terrestrial animals that reproduce late in life; 10 mGy/d for short-lived prolific terrestrial animals; 2.4 mGy/d for terrestrial plants; 5 mGy/d for birds. The paper identifies major areas of uncertainty regarding the selection of these nominal ENEVs for practical applications. (author)

  19. Valuation of ecological resources

    Energy Technology Data Exchange (ETDEWEB)

    Scott, M.J.; Bilyard, G.R.; Link, S.O.; Ricci, P.F.; Seely, H.E.; Ulibarri, C.A.; Westerdahl, H.E.

    1995-04-01

    Ecological resources are resources that have functional value to ecosystems. Frequently, these functions are overlooked in terms of the value they provide to humans. Environmental economics is in search of an appropriate analysis framework for such resources. In such a framework, it is essential to distinguish between two related subsets of information: (1) ecological processes that have intrinsic value to natural ecosystems; and (2) ecological functions that are values by humans. The present study addresses these concerns by identifying a habitat that is being displaced by development, and by measuring the human and ecological values associated with the ecological resources in that habitat. It is also essential to determine which functions are mutually exclusive and which are, in effect, complementary or products of joint production. The authors apply several resource valuation tools, including contingent valuation methodology (CVM), travel cost methodology (TCM), and hedonic damage-pricing (HDP). One way to derive upper-limit values for more difficult-to-value functions is through the use of human analogs, because human-engineered systems are relatively inefficient at supplying the desired services when compared with natural systems. Where data on the relative efficiencies of natural systems and human analogs exist, it is possible to adjust the costs of providing the human analog by the relative efficiency of the natural system to obtain a more realistic value of the function under consideration. The authors demonstrate this approach in an environmental economic case study of the environmental services rendered by shrub-steppe habitats of Benton County, Washington State.

  20. Restoring fish ecological quality in estuaries: Implication of interactive and cumulative effects among anthropogenic stressors.

    Science.gov (United States)

    Teichert, Nils; Borja, Angel; Chust, Guillem; Uriarte, Ainhize; Lepage, Mario

    2016-01-15

    Estuaries are subjected to multiple anthropogenic stressors, which have additive, antagonistic or synergistic effects. Current challenges include the use of large databases of biological monitoring surveys (e.g. the European Water Framework Directive) to help environmental managers prioritizing restoration measures. This study investigated the impact of nine stressor categories on the fish ecological status derived from 90 estuaries of the North East Atlantic countries. We used a random forest model to: 1) detect the dominant stressors and their non-linear effects; 2) evaluate the ecological benefits expected from reducing pressure from stressors; and 3) investigate the interactions among stressors. Results showed that largest restoration benefits were expected when mitigating water pollution and oxygen depletion. Non-additive effects represented half of pairwise interactions among stressors, and antagonisms were the most common. Dredged sediments, flow changes and oxygen depletion were predominantly implicated in non-additive interactions, whereas the remainder stressors often showed additive impacts. The prevalence of interactive impacts reflects a complex scenario for estuaries management; hence, we proposed a step-by-step restoration scheme focusing on the mitigation of stressors providing the maximum of restoration benefits under a multi-stress context. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Meningococcal Serogroup B Bivalent rLP2086 Vaccine Elicits Broad and Robust Serum Bactericidal Responses in Healthy Adolescents

    DEFF Research Database (Denmark)

    Vesikari, Timo; Østergaard, Lars Jørgen; Diez-Domingo, Javier

    2015-01-01

    BACKGROUND: Neisseria meningitidis serogroup B (MnB) is a leading cause of invasive meningococcal disease in adolescents and young adults. A recombinant factor H binding protein (fHBP) vaccine (Trumenba(®); bivalent rLP2086) was recently approved in the United States in individuals aged 10-25 years....... Immunogenicity and safety of 2- or 3-dose schedules of bivalent rLP2086 were assessed in adolescents. METHODS: Healthy adolescents (11 to ... bactericidal antibody assay using human complement (hSBA). Safety assessments included local and systemic reactions and adverse events. RESULTS: Bivalent rLP2086 was immunogenic when administered as 2 or 3 doses; the most robust hSBA responses occurred with 3 doses. The proportion of subjects with hSBA titers...

  2. Effect of Punica granatum on the virulence factors of cariogenic bacteria Streptococcus mutans.

    Science.gov (United States)

    Gulube, Zandiswa; Patel, Mrudula

    2016-09-01

    Dental caries is caused by acids produced by biofilm-forming Streptococcus mutans from fermentable carbohydrates and bacterial byproducts. Control of these bacteria is important in the prevention of dental caries. This study investigated the effect of the fruit peel of Punica granatum on biofilm formation, acid and extracellular polysaccharides production (EPS) by S. mutans. Pomegranate fruit peels crude extracts were prepared. The Minimum bactericidal concentrations (MBC) were determined against S. mutans. At 3 sub-bactericidal concentrations, the effect on the acid production, biofilm formation and EPS production was determined. The results were analysed using Kruskal-Wallis and Wilcoxon Rank Sum Tests. The lowest MBC was 6.25 mg/mL. Punica granatum significantly inhibited acid production (p mutans. The crude extract of P. granatum killed cariogenic S. mutans at high concentrations. At sub-bactericidal concentrations, it reduced biofilm formation, acid and EPS production. This suggests that P. granatum extract has the potential to prevent dental caries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Ecological security pattern construction based on ecological protection redlines in China

    Science.gov (United States)

    Zou, Changxin

    2017-04-01

    China is facing huge environmental problems with its current rapid rate of urbanization and industrialization, thus causing biodiversity loss, ecosystem service degradation on a major scale. Against this background, three previous examples (the nature reserve policy, the afforestation policy, and the zoning policy) are implemented in China. These all play important roles in protecting natural ecosystems, although they can sometimes cause new problems and lack rigorous targets for environmental outcomes. To overcome current management conflicts, China has proposed a new "ecological protection redlines" policy (EPR). EPR can be defined as the ecological baseline area needed to provide ecosystem services to guarantee and maintain ecological safety. This study analyzed the scope, objectives and technical methods of delineating EPR in China, and put forward the proposed scheme for the ecological security pattern based on EPR. We constructed three kinds of redlines in China, including key ecological function area redlines, ecological sensitive or fragile areas redlines, and forbidden development areas redlines. For the key ecological function area redlines, a total of 38 water conservation functional zones have been designated, covering a total area of 3.23 million km2; 14 soil conservation zones have been designated, covering a total area of 881700 km2; wind-prevention and sand-fixation zones across the country cover a total area of about 1.73 million km2, accounting for 57.13% of the total land area of the whole country. With respect to the ecologically vulnerable redlines, 18 ecologically vulnerable zones has been designated across the country, covering 2.19 million km2, accounting for 22.86% of the total land area of the whole country. Forbidden development areas redlines covered a total area of 3.29 million km2, accounting for 34.3% of the total land area of the whole country. We also suggest to form a complete ecological security pattern including patterns of

  4. Ecological effectiveness of oil spill countermeasures: how clean is clean?

    International Nuclear Information System (INIS)

    Baker, J.M.

    1999-01-01

    This paper with 94 references examines background levels of hydrocarbons and the difficulty of defining clean. Processes and timescales for natural cleaning, and factors affecting natural cleaning timescales are considered. Ecological advantages and disadvantages of clean-up methods are highlighted, and five case histories of oil spills are summarised. The relationships between ecological and socio-economic considerations, and the need for a net environmental benefit analysis which takes into account the advantages and disadvantages of clean-up responses and natural clean-up are discussed. A decision tree for evaluating the requirement for shore clean-up is illustrated. (UK)

  5. Ecology

    International Nuclear Information System (INIS)

    Kalusche, D.

    1978-01-01

    The book turns to the freshment, the teacher, for preparation of ecological topics for lessons, but also to pupils of the secondary stage II, and the main course ecology. The book was knowingly held simple with the restriction to: the ecosystem and its abiotic basic functions, simple articles on population biology, bioceonotic balance ith the questions of niche formation and the life form types coherent with it, of the substance and energy household, the production biology and space-wise and time-wise differentations within an ecological system form the main points. A central role in the volume is given to the illustrations. Their variety is to show and deepen the coherences shown. (orig./HP) [de

  6. Ecological risk assessment of hydropower dam construction based on ecological network analysis

    OpenAIRE

    Chen, Shaoqing; Fath, Brian D.; Chen, Bin

    2010-01-01

    Dam construction is regarded as one of the major factors contributing to significant modifications of the river ecosystems, and the ecological risk (ER) assessment of dam construction has received growing attention in recent years. In the present study, we explored the potential ecological risk caused by dam project based on the general principles of the ecological risk assessment. Ecological network analysis was proposed as the usable analytic method for the implement of ecological risk asse...

  7. Nuclear power ecology: comparative analysis

    International Nuclear Information System (INIS)

    Trofimenko, A.P.; Lips'ka, A.Yi.; Pisanko, Zh.Yi.

    2005-01-01

    Ecological effects of different energy sources are compared. Main actions for further nuclear power development - safety increase and waste management, are noted. Reasons of restrained public position to nuclear power and role of social and political factors in it are analyzed. An attempt is undertaken to separate real difficulties of nuclear power from imaginary ones that appear in some mass media. International actions of environment protection are noted. Risk factors at different energy source using are compared. The results of analysis indicate that ecological influence and risk for nuclear power are of minimum

  8. Effects of climate change on ecological disturbance in the Northern Rockies Region [Chapter 8

    Science.gov (United States)

    Loehman, Rachel A.; Bentz, Barbara J.; DeNitto, Gregg A.; Keane, Robert E.; Manning, Mary E.; Duncan, Jacob P.; Egan, Joel M.; Jackson, Marcus B.; Kegley, Sandra; Lockman, I. Blakey; Pearson, Dean E.; Powell, James A.; Shelly, Steve; Steed, Brytten E.; Zambino, Paul J.

    2018-01-01

    This chapter describes the ecology of important disturbance regimes in the Forest Service, U.S. Department of Agriculture (USFS) Northern Region and the Greater Yellowstone Area, hereafter called the Northern Rockies region, and potential shifts in these regimes as a consequence of observed and projected climate change. The term disturbance regime describes the general temporal and spatial characteristics of a disturbance agent - insect, disease, fire, weather, even human activity - and the effects of that agent on the landscape (table 8.1). More specifically, a disturbance regime is the cumulative effect of multiple disturbance events over space and time (Keane 2013). Disturbances disrupt an ecosystem, community, or population structure and change elements of the biological environment, physical environment, or both (White and Pickett 1985). The resulting shifting mosaic of diverse ecological patterns and structures in turn affects future patterns of disturbance, in a reciprocal, linked relationship that shapes the fundamental character of landscapes and ecosystems. Disturbance creates and maintains biological diversity in the form of shifting, heterogeneous mosaics of diverse communities and habitats across a landscape (McKinney and Drake 1998), and biodiversity is generally highest when disturbance is neither too rare nor too frequent on the landscape (Grime 1973).

  9. Diversity spurs diversification in ecological communities

    Science.gov (United States)

    Calcagno, Vincent; Jarne, Philippe; Loreau, Michel; Mouquet, Nicolas; David, Patrice

    2017-06-01

    Diversity is a fundamental, yet threatened, property of ecological systems. The idea that diversity can itself favour diversification, in an autocatalytic process, is very appealing but remains controversial. Here, we study a generalized model of ecological communities and investigate how the level of initial diversity influences the possibility of evolutionary diversification. We show that even simple models of intra- and inter-specific ecological interactions can predict a positive effect of diversity on diversification: adaptive radiations may require a threshold number of species before kicking-off. We call this phenomenon DDAR (diversity-dependent adaptive radiations) and identify mathematically two distinct pathways connecting diversity to diversification, involving character displacement and the positive diversity-productivity relationship. Our results may explain observed delays in adaptive radiations at the macroscale and diversification patterns reported in experimental microbial communities, and shed new light on the dynamics of ecological diversity, the diversity-dependence of diversification rates, and the consequences of biodiversity loss.

  10. Diversity spurs diversification in ecological communities.

    Science.gov (United States)

    Calcagno, Vincent; Jarne, Philippe; Loreau, Michel; Mouquet, Nicolas; David, Patrice

    2017-06-09

    Diversity is a fundamental, yet threatened, property of ecological systems. The idea that diversity can itself favour diversification, in an autocatalytic process, is very appealing but remains controversial. Here, we study a generalized model of ecological communities and investigate how the level of initial diversity influences the possibility of evolutionary diversification. We show that even simple models of intra- and inter-specific ecological interactions can predict a positive effect of diversity on diversification: adaptive radiations may require a threshold number of species before kicking-off. We call this phenomenon DDAR (diversity-dependent adaptive radiations) and identify mathematically two distinct pathways connecting diversity to diversification, involving character displacement and the positive diversity-productivity relationship. Our results may explain observed delays in adaptive radiations at the macroscale and diversification patterns reported in experimental microbial communities, and shed new light on the dynamics of ecological diversity, the diversity-dependence of diversification rates, and the consequences of biodiversity loss.

  11. Effect of Carvacrol on Salmonella Saintpaul Biofilms on Stainless ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effect of carvacrol against Salmonella Saintpaul biofilms on stainless steel surface. Methods: The effects of carvacrol on planktonic cells were evaluated by determining the minimum inhibitory concentration and minimal bactericidal concentration. The action of carvacrol on Salmonella Saintpaul ...

  12. Study on the Bactericidal Mechanism of Atmospheric-Pressure Low-Temperature Plasma against Escherichia coli and Its Application in Fresh-Cut Cucumbers

    Directory of Open Access Journals (Sweden)

    Yan Sun

    2018-04-01

    Full Text Available Atmospheric-pressure low-temperature plasma (APLTP was used to study the bactericidal mechanism against Escherichia coli (E. coli and its application in the sterilization of fresh-cut cucumbers. The morphological changes of E. coli cells subjected to APLTP were observed by scanning electron microscopy (SEM. Cell death was evaluated by fluorescence microscopy (FM. Cell membrane permeability was measured by conductivity changes, and the amount of soluble protein leakage in the bacterial supernatant was determined by measurement of protein concentration. Additionally, the effects of APLTP on the physicochemical and sensory quality of fresh-cut cucumber were studied by assessing the changes of moisture content, soluble solid content (SSC, pH value, color, relative conductivity, malondialdehyde (MDA level, vitamin C (Vc content, aroma composition and microstructure. The results showed that the E. coli cell morphology was changed due to the charged particles and active components produced by APLTP. The E. coli cell wall and cell membrane ruptured, cell content leaked out, cells lost the ability to reproduce and self-replicate, and the function of cell metabolism was directly affected and led to E. coli inactivation. In addition, there was no significant effect on physicochemical properties and sensory quality of fresh-cut cucumbers.

  13. Scale dependency in effectiveness, isolation, and social-ecological spillover of protected areas.

    Science.gov (United States)

    Ament, Judith M; Cumming, Graeme S

    2016-08-01

    Protected areas are considered vital for the conservation of biodiversity. Given their central role in many conservation strategies, it is important to know whether they adequately protect biodiversity within their boundaries; whether they are becoming more isolated from other natural areas over time; and whether they play a role in facilitating or reducing land-cover change in their surroundings. We used matching methods and national and local analyses of land-cover change to evaluate the combined effectiveness (i.e., avoided natural-cover loss), isolation (i.e., changes in adjacent areas), and spillover effects (i.e., impacts on adjacent areas) of 19 national parks in South Africa from 2000 to 2009. All parks had either similar or lower rates of natural-cover loss than matched control samples. On a national level, mean net loss of natural cover and mean net gain of cultivation cover decreased with distance from park boundary, but there was considerable variation in trends around individual parks, providing evidence for both increased isolation and buffering of protected areas. Fourteen parks had significant positive spillover and reduced natural-cover loss in their surroundings, whereas five parks experienced elevated levels of natural-cover loss. Conclusions about social-ecological spillover effects from protected areas depended heavily on the measures of land-cover change used and the scale at which the results were aggregated. Our findings emphasize the need for high-resolution data when assessing spatially explicit phenomena such as land-cover change and challenge the usefulness of large-scale (coarse grain, broad extent) studies for understanding social-ecological dynamics around protected areas. © 2016 Society for Conservation Biology.

  14. [Applied ecology: retrospect and prospect].

    Science.gov (United States)

    He, Xingyuan; Zeng, Dehui

    2004-10-01

    Applied ecology is evolved into a principal part of modern ecology that rapidly develops. The major stimulus for the development of applied ecology roots in seeking the solutions for the problems of human populations, resources and environments. Through four decades, the science of applied ecology has been becoming a huge group of disciplines. The future for the applied ecology should concern more with human-influenced and managed ecosystems, and acknowledge humans as the components of ecosystems. Nowadays and in future, the top-priorities in applied ecology should include following fields: sustainable ecosystems and biosphere, ecosystem services and ecological design, ecological assessment of genetically modified organisms, ecology of biological invasions, epidemical ecology, ecological forecasting, ecological process and its control. The authors believe that the comprehensive and active research hotspots coupled some new traits would occur around these fields in foreseeable future.

  15. Annual report of ecological research at the Savannah River Ecology Laboratory

    International Nuclear Information System (INIS)

    1984-09-01

    This report summarizes research conducted at the Savannah River Ecology Laboratory (SREL) during the annual period ending August 1, 1984. SREL is a regional research facility at the Savannah River Plant operated by the University of Georgia through a contract with the Department of Energy. It is part of the University of Georgia's Institute of Ecology. The overall goal of the research is to develop an understanding of the impact of various energy technologies and management practices on the ecosystems of the southeastern United States. SREL research is conducted by interdisciplinary research teams organized under three major divisions: (1) Biogeochemical Ecology, (2) Wetlands Ecology, and (3) Stress and Wildlife Ecology

  16. Antimicrobial effect of probiotics on bacterial species from dental plaque.

    Science.gov (United States)

    Zambori, Csilla; Morvay, Attila Alexandru; Sala, Claudia; Licker, Monica; Gurban, Camelia; Tanasie, Gabriela; Tirziu, Emil

    2016-03-31

    The antimicrobial role of probiotic Lactobacillus casei subspecies casei DG (L. casei DG) and of the mix culture of probiotic Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12 was tested on species of Staphylococcus, Streptococcus, Pasteurella, and Neisseria genera from supragingival sites from dogs with dental disease of different breed, age, sex, weight, and diet. The research was conducted on these four genera because of their importance in zoonotic infections after dog bites. Species from Staphylococcus, Streptococcus, Pasteurella, and Neisseria genera were isolated and identified. To test the antimicrobial efficacy of L. casei DG and the mixed culture of probiotic L. acidophilus LA-5 and Bifidobacterium bifidum BB-12 on the pathogenic species, the agar overlay method was used. L. casei DG had a bactericidal effect on all analyzed species isolated from Staphylococcus, Streptococcus, Pasteurella, and Neisseria genera after 24 hours of incubation. The mixed probiotic culture made up of L. acidophilus LA-5 and Bifidobacterium BB-12 species had no bactericidal effect on the species of Staphylococcus and Streptococcus genera, which were resistant. However, it had a bacteriostatic effect on several species of Pasteurella and Neisseria genera. This work highlights the antimicrobial potential of probiotics in vitro, demonstrating that the probiotic L. casei DG has a bactericidal effect on all analyzed species isolated from dental plaque and that the mix culture of probiotic L. acidophilus LA-5 and Bifidobacterium BB-12 has only a bacteriostatic effect.

  17. The ecological law and ecological human rights: to the question on necessity of formation

    OpenAIRE

    Khvorostov A. J.

    2012-01-01

    Necessity of the ecological law is determined by presence of ecological crisis and formed at formation of ecological function of the state. Ecological human rights and the citizen are natural human rights, however should be legally fixed and guaranteed by the state. The further functioning of a society is impossible without observance of norms of the ecological law and ecological human rights.

  18. Fast Growing Plantations for Wood Production - Integration of Ecological Effects and Economic Perspectives.

    Science.gov (United States)

    Bredemeier, Michael; Busch, Gerald; Hartmann, Linda; Jansen, Martin; Richter, Falk; Lamersdorf, Norbert P

    2015-01-01

    Biomass crops are perceived as a feasible means to substitute sizeable amounts of fossil fuel in the future. A prospect of CO2 reduction (resp. CO2 neutrality) is credited to biomass fuels, and thus a potential contribution to mitigate climate change. Short rotation coppices (SRCs) with fast growing poplar and willow trees are an option for producing high yields of woody biomass, which is suitable for both energetic and material use. One negative effect that comes along with the establishment of SRC may be a decrease in groundwater recharge, because high rates of transpiration and interception are anticipated. Therefore, it is important to measure, analyze, and model the effects of SRC-planting on landscape water budgets. To analyze the effects on the water budget, a poplar SRC plot was studied by measuring hydrological parameters to be used in the hydrological model WaSim. Results reveal very low or even missing ground water recharge for SRC compared to agricultural land use or grassland, especially succeeding dry years. However, this strong effect on plot level is moderated on the larger spatial scale of catchment level, for which the modeling was also performed. In addition to water, nutrient fluxes and budgets were studied. Nitrogen is still a crucial issue in today's agriculture. Intensive fertilization or increased applications of manure from concentrated livestock breeding are often leading to high loads of nitrate leaching, or enhanced N2O emissions to the atmosphere on arable crop fields. SRC or agroforestry systems on former crop land may offer an option to decrease such N losses, while simultaneously producing woody biomass. This is mainly due to the generally smaller N requirements of woody vegetation, which usually entail no need for any fertilization. The trees supply deep and permanent rooting systems, which can be regarded as a "safety net" to prevent nutrient leaching. Thus, SRC altogether can help to diminish N eutrophication. It is important to

  19. [Ecological memory and its potential applications in ecology: a review].

    Science.gov (United States)

    Sun, Zhong-yu; Ren, Hai

    2011-03-01

    Ecological memory (EM) is defined as the capability of the past states or experiences of a community to influence the present or future ecological responses of the community. As a relatively new concept, EM has received considerable attention in the study of ecosystem structure and function, such as community succession, ecological restoration, biological invasion, and natural resource management. This review summarized the definition, components, and categories of EM, and discussed the possible mechanisms and affecting factors of EM. Also, the potential applications of EM were proposed, in order to further understand the mechanisms of community succession and to guide ecological restoration.

  20. Deliberative Ecological Economics for Sustainability Governance

    Directory of Open Access Journals (Sweden)

    Richard B. Howarth

    2010-10-01

    Full Text Available We discuss the recent emergence of ‘deliberative ecological economics’, a field that highlights the potential of deliberation for improving environmental governance. We locate the emergence of this literature in the long concern in ecological economics over the policy implications of limited views of human action and its encounter with deliberative democracy scholarship and the model of communicative rationality as an alternative to utilitarianism. Considering criticisms over methods used and the focus of research in deliberative decision-making, we put forward a research agenda for deliberative ecological economics. Given the promising potential of deliberative processes for improving the effectiveness and legitimacy of environmental decision-making, work in this area could help advance both theory and practice in environmental governance.

  1. ECOLOGICAL CONSCIOUSNESS AS ONE OF THE MAIN PRINCIPLES OF ECOLOGICAL POLICY

    Directory of Open Access Journals (Sweden)

    Diana O. Dushkova

    2017-09-01

    Full Text Available The article presents the concept of ecological consciousness and analyzes main features of its development and implementation in the environmental policy in European practice on the example of Germany. The study of German experience is conditioned by the fact that among the other developed countries of the world Germany is the leading country in its active work carried out at all levels of the environmental policy. It is shown that actions aimed at the development of ecological culture and environmental education of the civil society in Germany are of the same priority as the use of renewable energy, development of green technologies, etc. The article provides an overview of the most important publications devoted to the phenomenon of ecological consciousness and highlights different approaches to this definition. Based on the German experience, it defines the prerequisites, main roots and sources of ecological consciousness creation and the ways in which it can be involved in the regional programs on sustainable development and ecological policy. It analyzes the main practical approaches to the implementation of the principles of ecological consciousness in Germany as well as the role of environmental organizations in the realization of environmentally oriented activities. Therefore, it presents the main results of socio-ecological surveys conducted in Germany and Russia and gives their comparative analysis. It indicates possible ways to transfer the German experience in the Russian context to improve the ecological awareness of the Russian society and to arise its ecological activity in addressing environmental issues.

  2. Vitamin C Pretreatment Enhances the Antibacterial Effect of Cold Atmospheric Plasma

    DEFF Research Database (Denmark)

    Helgadottir, Saga; Pandit, Santosh; Mokkapati, Venkata R. S. S.

    2017-01-01

    intervals and to evaluate the effect of combined treatment with vitamin C. We demonstrate that CAP is not very effective against 48 h mature bacterial biofilms of several common opportunistic pathogens: Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa. However, if bacterial biofilms...... are pre-treated with vitamin C for 15 min before exposure to CAP, a significantly stronger bactericidal effect can be obtained. Vitamin C pretreatment enhances the bactericidal effect of cold plasma by reducing the viability from 10 to 2% in E. coli biofilm, 50 to 11% in P. aeruginosa, and 61 to 18% in S....... epidermidis biofilm. Since it is not feasible to use extended CAP treatments in medical practice, we argue that the pre-treatment of infectious lesions with vitamin C prior to CAP exposure can be a viable route for efficient eradication of bacterial biofilms in many different applications....

  3. Effect of 137Cs on immunological reactivity

    International Nuclear Information System (INIS)

    Shubik, V.M.

    1975-01-01

    An important role of 137 Cs as a new ecological factor was shown by analyzing 31 different studies. The radioisotope may at present be detected in the organisms of all inhabitants of this planet. The migration of 137 Cs along the chain lichen-deer-man leads to its accumulation in the organism of humans living in the Extreme North and taking venison in their food. Although the high sensitivity of immunological reactions to various unfavourable environmental factors is well known, data on the effect of incorporated 137 Cs on immunity are scanty. Experiments on animals showed changes in factors of nonspecific immunity (phagocytic reaction of blood neutrophils, bactericidal activity, lysozyme and complement titres of blood serum) and specific immunity (formation of antiviral antibodies). The blood of animals injured by the isotope displays complete and incomplete autoantibodies. The dependence of immunobiological changes on the dose absorbed by the organism is shown. The 137 Cs intake of inhabitants of the Extreme North who eat venison did not, with the absorbed dose equalling up to 50 Mrem per year, lead to changes in their immunological reactivity. (author)

  4. Principles and methods of ecological information science in the solution of ecological problems of the nuclear power industry

    International Nuclear Information System (INIS)

    Vorob'ev, E.I.; Kokoreva, L.V.; Reznichenko, V.Y.

    1989-01-01

    The accident at Chernobyl' Atomic Power Plant has drawn attention to the ecological aspects of the development of the nuclear power industry. It has become clear that the stage of discussions of the importance of ecological problems and of the advisability of studying them further has passed. We now face the stage of carrying out specific tasks: the creation of regional and global monitoring systems; the collection and analysis of data on the effect of nuclear power on nature and humans; modeling and optimization of the strategy for developing the power industry with consideration for ecological aspects; ecological factoring in scientific and technical decisions related to atomic power plant design and siting; and so forth. Three main areas of application of ecological information science can be identified in the nuclear power industry: the creation of global data banks on the safety and reliability of enterprises involved in the nuclear fuel cycle; the development of standard tools for processing and analysis of ecological data; and the creation of tools to support decisions in the field of ecology. The authors' experience in working with information systems and various groups of untrained users (biologists, medical workers, ecologists, etc.) makes possible the conclusion that the most important requirement is a convenient interface that does not require a great deal of effort to master. In the systems discussed here, the authors used structured query languages and menus

  5. Nominal radio ecological benchmarks for the ecological risk assessment of radioactive waste management facilities

    Energy Technology Data Exchange (ETDEWEB)

    Garisto, N.C. [SENES Consultants Ltd., Richmond Hill, Ontario (Canada)]. E-mail: ngaristo@senes.ca

    2006-07-01

    Ecological risk assessments are used to assess potential ecological impacts from contaminated sites, such as radioactive waste management and disposal facilities. These assessments determine the overall significance of the impact of such facilities on non-human biota. Specific indicator species are selected as representative non-human biota at the study sites for the purposes of these risk assessments. Potential environmental impacts are generally assessed in terms of 'screening indices'. In simple terms, a screening index is the ratio of an estimated exposure level of the indicator species (or environmental concentration) divided by a level or concentration deemed unlikely to have a significant ecological effect. These latter levels or concentrations are referred to as 'estimated no effect value' or ENEVs. Nominal ENEV values for chronic radiation effects based on our current interpretation of literature data are presented in this paper. They are: 5 mGy/d for fish and amphibians; 2.4 mGy/d for aquatic plants; 2 mGy/d for reptiles; 5 mGy/d for benthic and terrestrial invertebrates; 1 mGy/d for slow-growing terrestrial animals that reproduce late in life; 10 mGy/d for short-lived prolific terrestrial animals; 2.4 mGy/d for terrestrial plants; 5 mGy/d for birds. The paper identifies major areas of uncertainty regarding the selection of these nominal ENEVs for practical applications. (author)

  6. The problem of spatial fit in social-ecological systems: detecting mismatches between ecological connectivity and land management in an urban region

    Directory of Open Access Journals (Sweden)

    Arvid Bergsten

    2014-12-01

    Full Text Available The problem of institutional fit in social-ecological systems has been empirically documented and conceptually discussed for decades, yet there is a shortage of approaches to systematically and quantitatively examine the level of fit. We address this gap, focusing on spatial fit in an urban and peri-urban regional landscape. Such landscapes typically exhibit significant fragmentation of remnant habitats, which can limit critical species dispersal. This may have detrimental effects on species persistence and ecosystem functioning if land use is planned without consideration of the spatial patterns of fragmentation. Managing habitat fragmentation is particularly challenging when the scale of fragmentation reaches beyond the control of single managers, thereby requiring different actors to coordinate their activities to address the problem at the appropriate scale. We present a research approach that maps patterns of collaborations between actors who manage different parts of a landscape, and then relates these patterns to structures of ecological connectivity. We applied our approach to evaluate the fit between a collaborative wetland management network comprising all 26 municipalities in the Stockholm County in Sweden and an ecologically defined network of dispersed but ecologically interconnected wetlands. Many wetlands in this landscape are either intersected by the boundary between two or more municipalities, or are located close to such boundaries, which implies a degree of ecological interconnectedness and a need for intermunicipal coordination related to wetland management across boundaries. We first estimated the level of ecological connectivity between wetlands in neighboring municipalities, and then used this estimate to elaborate the level of social-ecological fit vis-à-vis intermunicipal collaboration. We found that the level of fit was generally weak. Also, we identified critical misalignments of ecological connectivity and

  7. Ecological Effects in Cross-Cultural Differences Between U.S. and Japanese Color Preferences.

    Science.gov (United States)

    Yokosawa, Kazuhiko; Schloss, Karen B; Asano, Michiko; Palmer, Stephen E

    2016-09-01

    We investigated cultural differences between U.S. and Japanese color preferences and the ecological factors that might influence them. Japanese and U.S. color preferences have both similarities (e.g., peaks around blue, troughs around dark-yellow, and preferences for saturated colors) and differences (Japanese participants like darker colors less than U.S. participants do). Complex gender differences were also evident that did not conform to previously reported effects. Palmer and Schloss's (2010) weighted affective valence estimate (WAVE) procedure was used to test the Ecological Valence Theory's (EVT's) prediction that within-culture WAVE-preference correlations should be higher than between-culture WAVE-preference correlations. The results supported several, but not all, predictions. In the second experiment, we tested color preferences of Japanese-U.S. multicultural participants who could read and speak both Japanese and English. Multicultural color preferences were intermediate between U.S. and Japanese preferences, consistent with the hypothesis that culturally specific personal experiences during one's lifetime influence color preferences. Copyright © 2015 Cognitive Science Society, Inc.

  8. Climate and Land Use Change Effects on Ecological Resources in Three Watersheds: A Synthesis Report (Final Report)

    Science.gov (United States)

    EPA announced the availability of the final report, Climate and Land-Use Change Effects on Ecological Resources in Three Watersheds: A Synthesis Report. This report provides a summary of climate change impacts to selected watersheds and recommendations for how to improv...

  9. GNP - an ecological catastrophe?

    International Nuclear Information System (INIS)

    Lejon, E.

    1996-01-01

    In this chapter of the book author deals with the ecological aspects of the Gabcikovo-Nagymaros Project (GNP) as well as other projects on the European rivers. Ground water levels profiles are presented. Effects of the GNP on the forests, flora, and fauna are discussed. The conditions for delta region protection are presented. Chemical and radioactive contamination, as well as their synergistic effects are discussed

  10. Effects of silvicultural activity on ecological processes in floodplain forests of the southern United States

    International Nuclear Information System (INIS)

    Lockaby, B.G.; Stanturf, J.A.

    1996-01-01

    Activities associated with timber harvesting have occurred within floodplain forests in the southern United States for nearly two hundred years. However, it is only in the last ten years that any information has become available about the effects of harvesting on the ecological functions of this valuable resource. Hydrology is the driving influence behind all ecological processes in floodplains and, in most cases, timber harvesting alone has little long-term effect on hydroperiod. However, there may be some instances where logging roads, built in association with harvest sites , can alter hydroperiod to the extent that vegetation productivity is altered positively or negatively. There is no documentation that harvesting followed by natural regeneration represents a threat to ground or surface water quality on floodplain sites, as long as Best Management Practices are followed. Harvested floodplains may increase or have little effect on decomposition rates of surface organic matter. The nature of the effect seems to be controlled by site wetness. Data from recently harvested sites (i.e. within the last ten years) suggest that vegetation productivity is maintained at levels similar to that observed prior to harvests. During the early stages of stand development vegetation species composition is heavily influenced by harvest method. Similarly, amphibian populations (monitored as bioindicators of ecosystem recovery) seem to rebound rapidly following harvests, although species composition may be different. 40 refs, 3 figs

  11. Ecological traps in shallow coastal waters-Potential effect of heat-waves in tropical and temperate organisms.

    Directory of Open Access Journals (Sweden)

    Catarina Vinagre

    Full Text Available Mortality of fish has been reported in tide pools during warm days. That means that tide pools are potential ecological traps for coastal organisms, which happen when environmental changes cause maladaptive habitat selection. Heat-waves are predicted to increase in intensity, duration and frequency, making it relevant to investigate the role of tide pools as traps for coastal organisms. However, heat waves can also lead to acclimatization. If organisms undergo acclimatization prior to being trapped in tide pools, their survival chances may increase. Common tide pool species (46 species in total were collected at a tropical and a temperate area and their upper thermal limits estimated. They were maintained for 10 days at their mean summer sea surface temperature +3°C, mimicking a heat-wave. Their upper thermal limits were estimated again, after this acclimation period, to calculate each species' acclimation response. The upper thermal limits of the organisms were compared to the temperatures attained by tide pool waters to investigate if 1 tide pools could be considered ecological traps and 2 if the increase in upper thermal limits elicited by the acclimation period could make the organisms less vulnerable to this threat. Tropical tide pools were found to be ecological traps for an important number of common coastal species, given that they can attain temperatures higher than the upper thermal limits of most of those species. Tide pools are not ecological traps in temperate zones. Tropical species have higher thermal limits than temperate species, but lower acclimation response, that does not allow them to survive the maximum habitat temperature of tropical tide pools. This way, tropical coastal organisms seem to be, not only more vulnerable to climate warming per se, but also to an increase in the ecological trap effect of tide pools.

  12. Bactericidal effects of bioactive glasses on clinically important aerobic bacteria.

    Science.gov (United States)

    Munukka, Eveliina; Leppäranta, Outi; Korkeamäki, Mika; Vaahtio, Minna; Peltola, Timo; Zhang, Di; Hupa, Leena; Ylänen, Heimo; Salonen, Jukka I; Viljanen, Matti K; Eerola, Erkki

    2008-01-01

    Bioactive glasses (BAGs) have been studied for decades for clinical use, and they have found many dental and orthopedic applications. BAGs have also been shown to have an antibacterial effect e.g., on some oral microorganisms. In this extensive work we show that six powdered BAGs and two sol-gel derived materials have a clear antibacterial effect on 29 clinically important bacterial species. We also incorporated a rapid and accurate flow cytometric (FCM) method to calculate and standardize the numbers of viable bacteria inoculated in the suspensions used in the tests for antibacterial activity. In all materials tested growth inhibition could be demonstrated, although the concentration and time needed for the effect varied depending on the BAG. The most effective glass was S53P4, which had a clear growth-inhibitory effect on all pathogens tested. The sol-gel derived materials CaPSiO and CaPSiO II also showed a strong antibacterial effect. In summary, BAGs were found to clearly inhibit the growth of a wide selection of bacterial species causing e.g., infections on the surfaces of prostheses in the body after implantation.

  13. Individual and Interactive Effects of Socio-Ecological Factors on Dengue Fever at Fine Spatial Scale: A Geographical Detector-Based Analysis.

    Science.gov (United States)

    Cao, Zheng; Liu, Tao; Li, Xing; Wang, Jin; Lin, Hualiang; Chen, Lingling; Wu, Zhifeng; Ma, Wenjun

    2017-07-17

    Background : Large spatial heterogeneity was observed in the dengue fever outbreak in Guangzhou in 2014, however, the underlying reasons remain unknown. We examined whether socio-ecological factors affected the spatial distribution and their interactive effects. Methods : Moran's I was applied to first examine the spatial cluster of dengue fever in Guangzhou. Nine socio-ecological factors were chosen to represent the urbanization level, economy, accessibility, environment, and the weather of the 167 townships/streets in Guangzhou, and then the geographical detector was applied to analyze the individual and interactive effects of these factors on the dengue outbreak. Results : Four clusters of dengue fever were identified in Guangzhou in 2014, including one hot spot in the central area of Guangzhou and three cold spots in the suburban districts. For individual effects, the temperature ( q = 0.33) was the dominant factor of dengue fever, followed by precipitation ( q = 0.24), road density ( q = 0.24), and water body area ( q = 0.23). For the interactive effects, the combination of high precipitation, high temperature, and high road density might result in increased dengue fever incidence. Moreover, urban villages might be the dengue fever hot spots. Conclusions : Our study suggests that some socio-ecological factors might either separately or jointly influence the spatial distribution of dengue fever in Guangzhou.

  14. Effect of an intervention based on socio-ecological model in promoting physical activity of female employees

    Directory of Open Access Journals (Sweden)

    Amineh Sahranavard Gargari

    2018-03-01

    Full Text Available Although active life style is one of the main determining factors of health, the level of regular physical activities in women is less than in men and even this level decreases with aging. The aim of this study was to determine the effect of an intervention based on the social ecological model on promotion of physical activity among female employees. In this study, 160 women employed at Shabestar universities were selected, and randomly divided into two groups of control (n=80 and intervention (n=80. The intervention group received an instructional program according to the model, including one session for general instruction and four sessions for group discussion along with daily walking for 30 minutes within 8 weeks. In order to objectively measure the physical activity, the pedometer was used and to measure the perceived physical activity, the long form of International Physical Activity Questionnaire (IPAQ was applied. The variables related to the components of socio-ecological model were measured using the socio-ecological model questionnaire. A significant difference was found between two groups after the intervention in terms of That is, the average number of steps in walking in the intervention group increased significantly (from 4204 to 7882 steps per day, while it did not significantly increase in the control group. Thus, it can be argued that designing and implementing the interventional programs based on the socio-ecological model can promote physical activity behavior among employed women

  15. The radioiodine problem following the Chernobyl accident: ecology, dosimetry and medical effects

    International Nuclear Information System (INIS)

    Zvonova, I.A.

    1991-01-01

    Following the Chernobyl accident radioisotopes of iodine constituted the main dose-forming factor among the people who stayed on in the radioactively contaminated areas, and in a number of places the effective doses to the thyroid gland were up to two orders of magnitude higher than the whole-body dose stemming from uniform internal and external irradiation. We consider the mechanisms involved in the radioiodine contribution to the doses in the human organism, depending on intake path, life style and social and ecological factors. We illustrate, by means of examples, thyroid gland dose distribution for various age groups in the population, and discuss the medical effects and predict the long-term risks for the population of exposure to radioisotopes of iodine. (author)

  16. Ecological palaeoecology: a missing link between ecology and evolution

    Directory of Open Access Journals (Sweden)

    Rull, V.

    2014-12-01

    Full Text Available Palaeoecology is more than a palaeoenvironmental discipline; it is a science that is well-suited for supplying the empirical evidence necessary to test ecological hypotheses and contributes to our understanding of the interface of ecology and evolution. A critical time frame in palaeoecology is the often-overlooked Q-time dimension (centuries to millennia, which tends to be the most appropriate time dimension to examine ecology–evolution interactions. This paper discusses these topics from a conceptual perspective and provides examples of the contributions of palaeoecology to the study of ecology–evolution interactions. It also admonishes researchers about the threats of overlooking palaeoecology. Specifically, this paper argues that the neglect of palaeoecology may result in the loss of empirical support for ecology and its interactions with evolution as DNA-based phylogenetic and phylogeographic studies become more and more prevalent. The main concepts discussed are the time continuum, the notion of ecological palaeoecology and the empirical nature of palaeoecology in the face of more hypothetical approaches. More practically speaking, several examples are provided that highlight the utility of ecological palaeoecology for understanding a variety of processes, including ecological succession, community– environment equilibria, community assembly, biotic responses to environmental change, speciation and extinction, and biodiversity conservation. The ecology–evolution interface is analysed using two processes in which these disciplines interact intensively: ecological succession and long-range migration. This work concludes that both ecological palaeoecology (including ancient DNA records and DNA-based phylogenetics and phylogeography are needed to better understand the biosphere ecologically and the processes occurring at the ecology–evolution interface.La paleoecología es más que una disciplina ambiental, ya que proporciona las

  17. Ebselen and analogs as inhibitors of Bacillus anthracis thioredoxin reductase and bactericidal antibacterials targeting Bacillus species, Staphylococcus aureus and Mycobacterium tuberculosis.

    Science.gov (United States)

    Gustafsson, Tomas N; Osman, Harer; Werngren, Jim; Hoffner, Sven; Engman, Lars; Holmgren, Arne

    2016-06-01

    Bacillus anthracis is the causative agent of anthrax, a disease associated with a very high mortality rate in its invasive forms. We studied a number of ebselen analogs as inhibitors of B. anthracis thioredoxin reductase and their antibacterial activity on Bacillus subtilis, Staphylococcus aureus, Bacillus cereus and Mycobacterium tuberculosis. The most potent compounds in the series gave IC(50) values down to 70 nM for the pure enzyme and minimal inhibitory concentrations (MICs) down to 0.4 μM (0.12 μg/ml) for B. subtilis, 1.5 μM (0.64 μg/ml) for S. aureus, 2 μM (0.86 μg/ml) for B. cereus and 10 μg/ml for M. tuberculosis. Minimal bactericidal concentrations (MBCs) were found at 1-1.5 times the MIC, indicating a general, class-dependent, bactericidal mode of action. The combined bacteriological and enzymological data were used to construct a preliminary structure-activity-relationship for the benzoisoselenazol class of compounds. When S. aureus and B. subtilis were exposed to ebselen, we were unable to isolate resistant mutants on both solid and in liquid medium suggesting a high resistance barrier. These results suggest that ebselen and analogs thereof could be developed into a novel antibiotic class, useful for the treatment of infections caused by B. anthracis, S. aureus, M. tuberculosis and other clinically important bacteria. Furthermore, the high barrier against resistance development is encouraging for further drug development. We have characterized the thioredoxin system from B. anthracis as a novel drug target and ebselen and analogs thereof as a potential new class of antibiotics targeting several important human pathogens. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. THE ECOLOGY OF PATELLA LINNAEUS FROM THE CAPE ...

    African Journals Online (AJOL)

    The genus Patella comprises intertidal and infratidal animals, which- are important not only because of their relative abundance on most shores, but because of the marked effect they may have on the ecology of these shores. Despite this, little is known about their detailed ecology in South Africa. The present paper is an ...

  19. Influence of the surface properties on bactericidal and fungicidal activity of magnetron sputtered Ti–Ag and Nb–Ag thin films

    Energy Technology Data Exchange (ETDEWEB)

    Wojcieszak, D., E-mail: damian.wojcieszak@pwr.edu.pl [Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, 50-372 Wrocław (Poland); Mazur, M.; Kaczmarek, D. [Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, 50-372 Wrocław (Poland); Mazur, P. [Institute of Experimental Physics, University of Wrocław, Max Born 9, 50-204 Wrocław (Poland); Szponar, B. [Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla 12, 53–114 Wrocław (Poland); Domaradzki, J. [Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, 50-372 Wrocław (Poland); Kepinski, L. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okólna 2, 50-422 Wrocław (Poland)

    2016-05-01

    In this study the comparative investigations of structural, surface and bactericidal properties of Ti–Ag and Nb–Ag thin films have been carried out. Ti–Ag and Nb–Ag coatings were deposited on silicon and fused silica substrates by magnetron co-sputtering method using innovative multi-target apparatus. The physicochemical properties of prepared thin films were examined with the aid of X-ray diffraction, grazing incidence X-ray diffraction, scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy methods. Moreover, the wettability of the surface was determined. It was found that both, Ti–Ag and Nb–Ag thin films were nanocrystalline. In the case of Ag–Ti film presence of AgTi{sub 3} and Ag phases was identified, while in the structure of Nb–Ag only silver occurred in a crystal form. In both cases the average size of crystallites was ca. 11 nm. Moreover, according to scanning electron microscopy and atomic force microscopy investigations the surface of Nb–Ag thin films was covered with Ag-agglomerates, while Ti–Ag surface was smooth and devoid of silver particles. Studies of biological activity of deposited coatings in contact with Bacillus subtilis, Pseudomonas aeruginosa, Enterococcus hirae, Klebisiella pneumoniae, Escherichia coli, Staphylococcus aureus and Candida albicans were performed. It was found that prepared coatings were bactericidal and fungicidal even in a short term-contact, i.e. after 2 h. - Highlights: • Surface and biological properties of Ti–Ag and Nb–Ag thin films were examined. • Ag content was related to sputtering yields and nucleation of Ti and Nb. • For Nb–Ag film the agglomeration of silver at the surface was observed. • Composition and surface topography had an impact on antimicrobial properties. • Fine-grained surface was important in Ag ions release process.

  20. Influence of the surface properties on bactericidal and fungicidal activity of magnetron sputtered Ti–Ag and Nb–Ag thin films

    International Nuclear Information System (INIS)

    Wojcieszak, D.; Mazur, M.; Kaczmarek, D.; Mazur, P.; Szponar, B.; Domaradzki, J.; Kepinski, L.

    2016-01-01

    In this study the comparative investigations of structural, surface and bactericidal properties of Ti–Ag and Nb–Ag thin films have been carried out. Ti–Ag and Nb–Ag coatings were deposited on silicon and fused silica substrates by magnetron co-sputtering method using innovative multi-target apparatus. The physicochemical properties of prepared thin films were examined with the aid of X-ray diffraction, grazing incidence X-ray diffraction, scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy methods. Moreover, the wettability of the surface was determined. It was found that both, Ti–Ag and Nb–Ag thin films were nanocrystalline. In the case of Ag–Ti film presence of AgTi_3 and Ag phases was identified, while in the structure of Nb–Ag only silver occurred in a crystal form. In both cases the average size of crystallites was ca. 11 nm. Moreover, according to scanning electron microscopy and atomic force microscopy investigations the surface of Nb–Ag thin films was covered with Ag-agglomerates, while Ti–Ag surface was smooth and devoid of silver particles. Studies of biological activity of deposited coatings in contact with Bacillus subtilis, Pseudomonas aeruginosa, Enterococcus hirae, Klebisiella pneumoniae, Escherichia coli, Staphylococcus aureus and Candida albicans were performed. It was found that prepared coatings were bactericidal and fungicidal even in a short term-contact, i.e. after 2 h. - Highlights: • Surface and biological properties of Ti–Ag and Nb–Ag thin films were examined. • Ag content was related to sputtering yields and nucleation of Ti and Nb. • For Nb–Ag film the agglomeration of silver at the surface was observed. • Composition and surface topography had an impact on antimicrobial properties. • Fine-grained surface was important in Ag ions release process.

  1. Ecological operation for Three Gorges Reservoir

    Directory of Open Access Journals (Sweden)

    Wen-xian Guo

    2011-06-01

    Full Text Available The traditional operation of the Three Gorges Reservoir has mainly focused on water for flood control, power generation, navigation, water supply, and recreation, and given less attention to the negative impacts of reservoir operation on the river ecosystem. In order to reduce the negative influence of reservoir operation, ecological operation of the reservoir should be studied with a focus on maintaining a healthy river ecosystem. This study considered ecological operation targets, including maintaining the river environmental flow and protecting the spawning and reproduction of the Chinese sturgeon and four major Chinese carps. Using flow data from 1900 to 2006 at the Yichang gauging station as the control station data for the Yangtze River, the minimal and optimal river environmental flows were analyzed, and eco-hydrological targets for the Chinese sturgeon and four major Chinese carps in the Yangtze River were calculated. This paper proposes a reservoir ecological operation model, which comprehensively considers flood control, power generation, navigation, and the ecological environment. Three typical periods, wet, normal, and dry years, were selected, and the particle swarm optimization algorithm was used to analyze the model. The results show that ecological operation modes have different effects on the economic benefit of the hydropower station, and the reservoir ecological operation model can simulate the flood pulse for the requirements of spawning of the Chinese sturgeon and four major Chinese carps. According to the results, by adopting a suitable re-operation scheme, the hydropower benefit of the reservoir will not decrease dramatically while the ecological demand is met. The results provide a reference for designing reasonable operation schemes for the Three Gorges Reservoir.

  2. Ecological quality of production: accounting approach on sustainable development

    Directory of Open Access Journals (Sweden)

    N.P. Syroid

    2016-12-01

    Full Text Available The specific weight of resource and power consuming technologies that is typical for Ukrainian economy, the absence of effective legal, administrative and economic mechanisms of management of nature and the low level of ecological society consciousness have led to the significant deterioration of environment state in Ukraine, excessive pollution of waters, air, and soil, accumulation of a large number of waste products. Besides, the produce as a result of such enterprises’ production affects consumers’ health badly. This causes the need to develop theory and methodology of production ecological quality accounting. The problem of quality is the most important factor of increasing of life level, economic, social and ecological security in market economy. This, the current research aims to formulate the essence of concept “ecological quality of production” The research determines that ecological quality is characterized by the following main 6 aspects: social, technical, legal, economic, aesthetic and ecological. If one of these six aspects does not work, we cannot speak about ecological quality of a certain commodity. Many various factors influence upon the level of ecological quality of products and services. According to their contents and directions, they can be united into the following main 6 groups: technical, organizational, economic and social, ecological and aesthetic and legal. The article determines the directions of production ecological quality increasing.

  3. Cytogenetic effects of weak and combined actions in plants in connection with a problem of ecological rating

    International Nuclear Information System (INIS)

    Geras'kin, S.A.; Dikarev, V.G.; Udalova, A.A.; Dikareva, N.S.; Vasil'ev, D.V.; Evseeva, T.I.

    2002-01-01

    It is compared sanitary-hygienic and ecological approaches to rating of ionizing radiation action. The features of formation of cytogenetic effects in plants in conditions of separate and combined with factors of other nature action of ionizing radiation low doses are considered. (author)

  4. Formalizing the definition of meta-analysis in Molecular Ecology.

    Science.gov (United States)

    ArchMiller, Althea A; Bauer, Eric F; Koch, Rebecca E; Wijayawardena, Bhagya K; Anil, Ammu; Kottwitz, Jack J; Munsterman, Amelia S; Wilson, Alan E

    2015-08-01

    Meta-analysis, the statistical synthesis of pertinent literature to develop evidence-based conclusions, is relatively new to the field of molecular ecology, with the first meta-analysis published in the journal Molecular Ecology in 2003 (Slate & Phua 2003). The goal of this article is to formalize the definition of meta-analysis for the authors, editors, reviewers and readers of Molecular Ecology by completing a review of the meta-analyses previously published in this journal. We also provide a brief overview of the many components required for meta-analysis with a more specific discussion of the issues related to the field of molecular ecology, including the use and statistical considerations of Wright's FST and its related analogues as effect sizes in meta-analysis. We performed a literature review to identify articles published as 'meta-analyses' in Molecular Ecology, which were then evaluated by at least two reviewers. We specifically targeted Molecular Ecology publications because as a flagship journal in this field, meta-analyses published in Molecular Ecology have the potential to set the standard for meta-analyses in other journals. We found that while many of these reviewed articles were strong meta-analyses, others failed to follow standard meta-analytical techniques. One of these unsatisfactory meta-analyses was in fact a secondary analysis. Other studies attempted meta-analyses but lacked the fundamental statistics that are considered necessary for an effective and powerful meta-analysis. By drawing attention to the inconsistency of studies labelled as meta-analyses, we emphasize the importance of understanding the components of traditional meta-analyses to fully embrace the strengths of quantitative data synthesis in the field of molecular ecology. © 2015 John Wiley & Sons Ltd.

  5. [Effectiveness and limits of the cleaners steam in hospitals].

    Science.gov (United States)

    Meunier, O; Meistermann, C; Schwebel, A

    2009-05-01

    We assessed bactericidal activity of the cleaners steam used for the bio-cleaning of the hospital surfaces. We performed of samples (Rodac) before and after use of cleaner steam and compared with bactericidal effect of disinfecting detergent used in hospital for surfaces. We studied this effectiveness for different time of steam contact. Finally, we wanted to prove, by air sampling, that aero-bio-contamination was possible generated by using cleaners steam. We show that bactericidal effect of the cleaner steam is superior of some tested disinfecting detergent, for the treatment of one square meter till 2 min. This effectiveness diminishes to be just identical in that some disinfecting detergent when use of the cleaner steam is up to two or four square meters surfaces till 2 min. On the other hand, the cleaner steam is less efficient in terms of bacterial destruction when the time of contact steam-soil is superior in 2 min for six square meter surface. The air bacterial pollution, generated by the use of the cleaner steam, is restricted and not significantly augmented if measured in 44 cm above the soil in the course of cleaning. The cleaner steam is indeed a very good equipment for the cleaning of surfaces but it is necessary to respect a time of minimal contact of 2 min for four square meters surfaces treaties to acquire an antibacterial effect at least so important as that acquired with used disinfecting detergent. The disinfection of surfaces is then user-dependent and the time of requested contact is can be not compatible with hospital obligations.

  6. Globalization and sustainable development: a political ecology strategy to realize ecological justice

    OpenAIRE

    Byrne, John; Glover, Leigh; Alrøe, Hugo Fjelsted

    2006-01-01

    Organic agriculture is, like mainstream agriculture, faced with the challenges of globalization and sustainable development. Ecological justice, the fair distribution of livelihoods and environments, has emerged as a key concept in efforts, on the one hand, to resist negative consequences of globalization and ecological modernization and, on the other to propose new agenda and institutional arrangements. This chapter investigates the role that ecological justice as a political ecology strateg...

  7. Construction and Application of Enhanced Remote Sensing Ecological Index

    Science.gov (United States)

    Wang, X.; Liu, C.; Fu, Q.; Yin, B.

    2018-04-01

    In order to monitor the change of regional ecological environment quality, this paper use MODIS and DMSP / OLS remote sensing data, from the production capacity, external disturbance changes and human socio-economic development of the three main factors affecting the quality of ecosystems, select the net primary productivity, vegetation index and light index, using the principal component analysis method to automatically determine the weight coefficient, construction of the formation of enhanced remote sensing ecological index, and the ecological environment quality of Hainan Island from 2001 to 2013 was monitored and analyzed. The enhanced remote sensing ecological index combines the effects of the natural environment and human activities on ecosystems, and according to the contribution of each principal component automatically determine the weight coefficient, avoid the design of the weight of the parameters caused by the calculation of the human error, which provides a new method for the operational operation of regional macro ecological environment quality monitoring. During the period from 2001 to 2013, the ecological environment quality of Hainan Island showed the characteristics of decend first and then rise, the ecological environment in 2005 was affected by severe natural disasters, and the quality of ecological environment dropped sharply. Compared with 2001, in 2013 about 20000 square kilometers regional ecological environmental quality has improved, about 8760 square kilometers regional ecological environment quality is relatively stable, about 5272 square kilometers regional ecological environment quality has decreased. On the whole, the quality of ecological environment in the study area is good, the frequent occurrence of natural disasters, on the quality of the ecological environment to a certain extent.

  8. Characterization and relative photonic efficiencies of a new nanocarbon/TiO2 composite photocatalyst designed for organic dye decomposition and bactericidal activity

    International Nuclear Information System (INIS)

    Oh, Won-Chun; Jung, Ah-Reum; Ko, Weon-Bae

    2009-01-01

    Two kinds of nanocarbon/TiO 2 composite photocatalysts were synthesized using an MCPBA oxidation method, employing MWCNT (multi-wall carbon nanotubes) and C 60 as nanocarbon sources and TNB (titanium (IV) n-butoxide) as a titanium dioxide source. From the XRD patterns of the composites, structural variations revealed the C 60 /TiO 2 composite having a mixture of anatase and rutile forms, with the MWCNT/TiO 2 composite presenting only the anatase phase. Elemental analysis indicated a predominance of carbon and Ti metal peaks over any other element. From the SEM results, the TiO 2 particles were dispersed regularly on the fullerene surface with large clusters bearing irregular agglomerate dispersions. However, the MWCNT/TiO 2 showed homogenous distributions with only individual MWCNT, covered with TiO 2 and without any jam-like aggregates between the two. According to the photocatalytic results, the relationship of the -ln (c/c 0 ) of the solution products of the organic dye, methylene blue (MB), as a function of time under UV irradiation, showed linearity properties with first-order kinetics and an excellent photodegradation effect. From the measured bactericidal effects, the inhibition zone was defined by the halo method with the curves of E. coli inactivation denoting effectiveness of the nanocarbon/TiO 2 composites in the sunlight.

  9. Eco-friendly and green synthesis of silver nanoparticles using leaf extract of Strychnos potatorum Linn.F. and their bactericidal activities.

    Science.gov (United States)

    Kagithoju, Srikanth; Godishala, Vikram; Nanna, Rama Swamy

    2015-10-01

    Inspired green synthesis of metallic nanoparticles is evolving as an important branch of nanotechnology. Traditionally these are manufactured by wet chemical methods which require toxic and flammable chemicals. We report for the first time an economic and eco-friendly green synthesis of silver nanoparticles using Strychnos potatorum aqueous leaf extract from 3 mM silver nitrate solution. Nanoparticles thus formed are confirmed and characterized by using UV-Vis absorption spectroscopy, SEM and XRD measurements. The XRD and SEM analysis showed the average particle size of nanoparticles as 28 nm as well as revealed their (mixed, i.e., cubic and hexagonal) structure. Further, these green synthesized nanoparticles showed bactericidal activity against multidrug-resistant human pathogenic bacteria.

  10. Epithelial Cell Damage Activates Bactericidal/Permeability Increasing-Protein (BPI Expression in Intestinal Epithelium

    Directory of Open Access Journals (Sweden)

    Arjun Balakrishnan

    2017-08-01

    Full Text Available As the first line of defense against invading pathogen, intestinal epithelium produces various antimicrobial proteins (AMP that help in clearance of pathogen. Bactericidal/permeability-increasing protein (BPI is a 55 kDa AMP that is expressed in intestinal epithelium. Dysregulation of BPI in intestinal epithelium is associated with various inflammatory diseases like Crohn’s Disease, Ulcerative colitis, and Infectious enteritis’s. In this paper, we report a direct correlation between intestinal damage and BPI expression. In Caco-2 cells, we see a significant increase in BPI levels upon membrane damage mediated by S. aureus infection and pore-forming toxins (Streptolysin and Listeriolysin. Cells detect changes in potassium level as a Danger-associated molecular pattern associated with cell damage and induce BPI expression in a p38 dependent manner. These results are further supported by in vivo findings that the BPI expression in murine intestinal epithelium is induced upon infection with bacteria which cause intestinal damage (Salmonella Typhimurium and Shigella flexneri whereas mutants that do not cause intestinal damage (STM ΔfliC and STM ΔinvC did not induce BPI expression. Our results suggest that epithelial damage associated with infection act as a signal to induce BPI expression.

  11. The beauty of sensory ecology.

    Science.gov (United States)

    Otálora-Luna, Fernando; Aldana, Elis

    2017-08-10

    Sensory ecology is a discipline that focuses on how living creatures use information to survive, but not to live. By trans-defining the orthodox concept of sensory ecology, a serious heterodox question arises: how do organisms use their senses to live, i.e. to enjoy or suffer life? To respond to such a query the objective (time-independent) and emotional (non-rational) meaning of symbols must be revealed. Our program is distinct from both the neo-Darwinian and the classical ecological perspective because it does not focus on survival values of phenotypes and their functions, but asks for the aesthetic effect of biological structures and their symbolism. Our message recognizes that sensing apart from having a survival value also has a beauty value. Thus, we offer a provoking and inspiring new view on the sensory relations of 'living things' and their surroundings, where the innovating power of feelings have more weight than the privative power of reason.

  12. Ecologically relevant levels of multiple, common marine stressors suggest antagonistic effects.

    Science.gov (United States)

    Lange, Rolanda; Marshall, Dustin

    2017-07-24

    Stressors associated with global change will be experienced simultaneously and may act synergistically, so attempts to estimate the capacity of marine systems to cope with global change requires a multi-stressor approach. Because recent evidence suggests that stressor effects can be context-dependent, estimates of how stressors are experienced in ecologically realistic settings will be particularly valuable. To enhance our understanding of the interplay between environmental effects and the impact of multiple stressors from both natural and anthropogenic sources, we conducted a field experiment. We explored the impact of multiple, functionally varied stressors from both natural and anthropogenic sources experienced during early life history in a common sessile marine invertebrate, Bugula neritina. Natural spatial environmental variation induced differences in conspecific densities, allowing us to test for density-driven context-dependence of stressor effects. We indeed found density-dependent effects. Under high conspecific density, individual survival increased, which offset part of the negative effects of experiencing stressors. Experiencing multiple stressors early in life history translated to a decreased survival in the field, albeit the effects were not as drastic as we expected: our results are congruent with antagonistic stressor effects. We speculate that when individual stressors are more subtle, stressor synergies become less common.

  13. Ecological footprint and food consumption in Minna, Nigeria

    International Nuclear Information System (INIS)

    Razack, N T A A; Ludin, A N M

    2014-01-01

    Cities all over the world are growing and will continue to grow as development is tilted toward development at the expense of the rural area. As a result of this there is need for development of housing that constructed at the urban fringes. There are many tools to measure sustainability of a city and one of them is Ecological Footprint. This paper looked at the Ecological Footprint and food consumption Minna, Nigeria. The paper evaluates the effectiveness of Ecological Footprint in the context of urban development. The survey revealed that food contributed 38.77% of the Ecological Footprint of Minna. This is as a result of the lifestyle of the people. It was concluded that the Ecological Footprint of Minna (1.096gha) is lower than the national bio-capacity (1.24gha), which therefore make city sustainable. Therefore, the people of Minna have to develop a lifestyle that will be sustainable better than the present practice

  14. INDUSTRIAL ECOLOGY A NEW PATH TO SUSTAINABILITY: A REVIEW

    Directory of Open Access Journals (Sweden)

    Felichesmi Selestine Lyakurwa

    2014-09-01

    Full Text Available A precise understanding of the link between industrial ecology and sustainability is vitally important for sustainable environmental performances. In this study an intensive review of industrial ecology principles, its application areas and the extent to which industrial ecology has been applied was documented. It was observed that effective application of industrial ecology is critical for sustainability, since the industry is the main polluter of the environment. It was further infered that, there is inadequate application of industrial ecology by developing countries. Thus, I hypothesis that, there is great opportunity for new investment in this field, considering the absence of modern means for the liquid and solid waste management. For example improper incineration of wastes such as hospital wastes and electrical and electronic equipment was perceived to bring health problems in the near future. Thus, it is time for governments, both in developed and developing countries to increase the applicability of industrial ecology, for sustainable social, political, economic and environmental sustainability.

  15. Deep ecology: A movement and a new approach to solving environmental problems

    Directory of Open Access Journals (Sweden)

    Mišković Milan M.

    2016-01-01

    Full Text Available In the industrial society, nature is conceived as a resource for unlimited exploitation, and the entropic effects of its pollution and depletion can be effectively controlled and resolved. Non-human entities are viewed as raw materials for technical manipulation and the increase in the standard of living for consumers in mass societies. Contrary to such utilitarian pragmatism, some new views on the relationship of man, society and nature are appearing, as well as different concepts of environmentally balanced development. According to these views, the transition to ecological society and ecological culture will not be possible without replacing the current anthropocentric ethics with the ecocentric or environmental ethics. Deep ecology arises in the spectrum of environmental ethics theories. It is considered as a movement and a new approach to solving environmental problems. Deep ecology is a type of ecosophy formed by Arne Nes, and it focuses on wisdom and ecological balance. It is based on ecological science, but it asks deeper questions about the causes of the ecological crisis and corresponds to the general discourse on sustainable development. The article discusses the platform of deep ecology movement and gives the basic principles of deep ecology. It gives explanations of the two basic norms of deep ecology (self-understanding and biospheric egalitarianism and criticism of these concepts.

  16. Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

    International Nuclear Information System (INIS)

    Laha, Dipranjan; Pramanik, Arindam; Laskar, Aparna; Jana, Madhurya; Pramanik, Panchanan; Karmakar, Parimal

    2014-01-01

    Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain

  17. Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

    Energy Technology Data Exchange (ETDEWEB)

    Laha, Dipranjan; Pramanik, Arindam [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Laskar, Aparna [CSIR-Indian Institute of Chemical Biology, Kolkata 700032 (India); Jana, Madhurya [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Pramanik, Panchanan [Department of Chemistry, Indian Institute of Technology, Kharagpur 721302 (India); Karmakar, Parimal, E-mail: pkarmakar_28@yahoo.co.in [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India)

    2014-11-15

    Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain.

  18. Comparison of antimicrobial effects of titanium tetrafluoride, chlorhexidine, xylitol and sodium fluoride on streptococcus mutans: An in-vitro study.

    Science.gov (United States)

    Eskandarian, Tahereh; Motamedifar, Mohammad; Arasteh, Peyman; Eghbali, Seyed Sajad; Adib, Ali; Abdoli, Zahra

    2017-03-01

    No studies have yet documented the bactericidal effects of TiF4, and its role in the treatment of dental caries, and no definite protocol has been introduced to regulate its use. The aim of this study was to determine the antimicrobial/bactericidal effects of TiF4 on Streptococcus Mutans ( S. Mutans ) and to compare it with chlorhexidine (Chx), sodium fluoride (NaF) and xylitol. This study was conducted at the Shiraz University of Medical Sciences microbiology laboratory during March 2015 to September 2015. In this in-vitro study, first a bacterial suspension was prepared and adjusted to a 0.5 McFarland standard (equivalent to 1×10 8 CFU/ml). The minimal inhibitory concentration (MIC) and minimal bactericidal concentrations (MBC) of TiF4, Chx, NaF and xylitol were assessed using broth microdilution assay and disk diffusion methods. In order to neutralize the acidic nature of TiF4, we used a sodium hydroxide preparation to obtain a pH of 7.2 and repeated all of the previous tests with the neutralized TiF4 solution. We reported the final results as percentages where appropriate. The MIC of TiF4, NaF and Chx for S. Mutans were 12.5%, 12.5% and 6.25%, respectively. At a concentration of 12.5% the inhibition zone diameters were 9 mm, 15mm and 14mm for TiF4, NaF and Chx, respectively. The MBC was 25%, 12.5% and 12.5% for TiF4, NaF and Chx, respectively. Xylitol failed to show any bactericidal or growth inhibitory effect in all of its concentrations. When we repeated the tests with an adjusted pH, identical results were obtained. TiF4 solutions have anti-growth and bactericidal effects on S. Mutans at a concentration of 12.5% which is comparable with chlorhexidine and NaF, indicating the possible use of this solution in dental practice as an anti-cariogenic agent, furthermore the antimicrobial activity is unaffected by pH of the environment.

  19. Ecological materials for solar architecture

    International Nuclear Information System (INIS)

    Zbasnik-Senegaenik, M.

    2000-01-01

    In general, materials which have been used in construction, have had a negative influence in all the phases of the life cycle. The effects can be seen in the form of tampering with the environment, overuse of electric power, harmful emissions, wastes and in the form of pollution with vapours, dust, fibres, poisonous and radioactive matter. Materials can be divided into three groups regarding their origin: natural materials, artificial mineral materials and synthetic materials. An assessment of separate influences on macro- and micro-environment shows a hierarchical scale of suitability of material use. Materials of natural origin (stone, clay, wood) and less artificial ones (brick, ceramic, metals, glass, lime, cement, concrete, mineral thermal-insulation materials) are most convenient for man and environment. Synthetic materials (plastics, polymers, synthetic thermal-insulation materials, synthetic pastes, composed synthetic materials) negatively influence macro- and micro-environment and therefore they should be used on an extremely selective and premeditated basis. Ecological structure of the future will demand the nowadays-established exploitation of natural sources of power and passive exploitation of natural resources. Introduction of ecological constructing is to be foreseen in planing of the future buildings. At present ecological constructing includes two principles ecological selection of materials and disintegration of composite materials and constructions. (au)

  20. Evolutionary ecology of virus emergence.

    Science.gov (United States)

    Dennehy, John J

    2017-02-01

    The cross-species transmission of viruses into new host populations, termed virus emergence, is a significant issue in public health, agriculture, wildlife management, and related fields. Virus emergence requires overlap between host populations, alterations in virus genetics to permit infection of new hosts, and adaptation to novel hosts such that between-host transmission is sustainable, all of which are the purview of the fields of ecology and evolution. A firm understanding of the ecology of viruses and how they evolve is required for understanding how and why viruses emerge. In this paper, I address the evolutionary mechanisms of virus emergence and how they relate to virus ecology. I argue that, while virus acquisition of the ability to infect new hosts is not difficult, limited evolutionary trajectories to sustained virus between-host transmission and the combined effects of mutational meltdown, bottlenecking, demographic stochasticity, density dependence, and genetic erosion in ecological sinks limit most emergence events to dead-end spillover infections. Despite the relative rarity of pandemic emerging viruses, the potential of viruses to search evolutionary space and find means to spread epidemically and the consequences of pandemic viruses that do emerge necessitate sustained attention to virus research, surveillance, prophylaxis, and treatment. © 2016 New York Academy of Sciences.

  1. Low-intensity electromagnetic irradiation of 70.6 and 73 GHz frequencies enhances the effects of disulfide bonds reducer on Escherichia coli growth and affects the bacterial surface oxidation-reduction state

    International Nuclear Information System (INIS)

    Torgomyan, Heghine; Trchounian, Armen

    2011-01-01

    Highlights: → Low intensity 70.6 and 73 GHz electromagnetic irradiation (EMI) strongly suppressed Escherichia coli growth at 73 GHz and pH 7.3. → Reducer DL-dithiothreitol had bactericidal effect and disturbed the SH-groups number. → EMI enhanced E. coli sensitivity toward dithiothreitol. → EMI decreased the SH-groups number of membrane disturbed by ATP and N,N'-dicyclohexycarbodiimide. → The changed membrane oxidation-reduction state could be the primary mechanisms in EMI effects. -- Abstract: Low-intensity electromagnetic irradiation (EMI) of 70.6 and 73 GHz frequencies (flux capacity - 0.06 mW cm -2 ) had bactericidal effects on Escherichia coli. This EMI (1 h) exposure suppressed the growth of E. coli K-12(λ). The pH value (6.0-8.0) did not significantly affect the growth. The lag-phase duration was prolonged, and the growth specific rate was inhibited, and these effects were more noticeable after 73 GHz irradiation. These effects were enhanced by the addition of DL-dithiothreitol (DTT), a strong reducer of disulfide bonds in surface membrane proteins, which in its turn also has bactericidal effect. Further, the number of accessible SH-groups in membrane vesicles was markedly decreased by EMI that was augmented by N,N'-dicyclohexycarbodiimide and DTT. These results indicate a change in the oxidation-reduction state of bacterial cell membrane proteins that could be the primary membranous mechanism in the bactericidal effects of low-intensity EMI of the 70.6 and 73 GHz frequencies.

  2. Dynamic ecological-economic modeling approach for management of shellfish aquaculture

    CSIR Research Space (South Africa)

    Nobre, AM

    2008-02-01

    Full Text Available The objective of this report is to conceptualize ecological and economic interactions in mariculture; to implement a dynamic ecological-economic model in order to: simulate the socio-economics of aquaculture production, simulate its effects...

  3. Potential Ecological Effects of Contaminants in the Exposed Par Pond Sediments

    International Nuclear Information System (INIS)

    Paller, M.H.; Wike, L.D.

    1996-08-01

    Sediment and small mammal samples were collected from the exposed sediments of Par Pond in early 1995, shortly before the reservoir was refilled after a 4-year drawdown. Sampling was confined to elevations between 58 and 61 meters (190 and 200 feet) above mean sea level, which includes the sediments likely to be exposed if the Par Pond water level is permitted to fluctuate naturally. Both soil and small mammal samples were analyzed for a number of radionuclides and metals. Some of the soil samples were also analyzed for organic contaminants. The objective of the study was to determine if contaminant levels in the Par Pond sediments were high enough to cause deleterious ecological effects

  4. A hybrid land-water-environment model for identification of ecological effect and risk under uncertain meteorological precipitation in an agroforestry ecosystem.

    Science.gov (United States)

    Zeng, Xueting; Li, Tienan; Chen, Cong; Si, Zhenjiang; Huang, Guohe; Guo, Ping; Zhuang, Xiaowen

    2018-08-15

    In this study, a hybrid land-water-environment (LWE) model is developed for identifying ecological effect and risk under uncertain precipitation in an agroforestry ecosystem. A simulation-based fuzzy-stochastic programming with risk analysis (SFSR) method is used into LWE model to reflect the meteorological impacts; meanwhile, it also can quantify artificial fuzziness (e.g., risk attitude of policymaker) and natural vagueness (e.g., ecological function) in decision-making. The developed LWE model with SFSR method is applied to a practical agroforestry ecosystem in China. Results of optimized planting scale, irrigative water schedule, pollution mitigation scheme, and system benefit under changed rainfall, precise risk-adoption and vague ecological function are obtained; meanwhile their corresponding ecological effects and risks are analyzed. It found that current LWE plans could generate massive water deficits (e.g., 23.22×10 6 m 3 in crop irrigation and 26.32×10 6 m 3 in forest protection at highest) due to over-cultivation and excessive pollution discharges (e.g., the highest excessive TP and TN discharges would reach 460.64 and 15.30×10 3 ton) due to irrational fertilization, which would increase regional ecological risks. In addition, fifteen scenarios associated with withdrawing cultivation and recovering forest based on regional environment heterogeneity (such as soil types) have been discussed to adjust current agriculture-environment policies. It found that, the excessive pollution discharges (TN and TP) could be reduced 12.95% and 18.32% at highest through ecological expansions, which would generate higher system benefits than that without withdrawing farmland and recovering forest. All above can facilitate local policymakers to modulate a comprehensive LWE with more sustainable and robust manners, achieving regional harmony between socio-economy and eco-environment. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Ecological and biomedical effects of effluents from near-term electric vehicle storage battery cycles

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    An assessment of the ecological and biomedical effects due to commercialization of storage batteries for electric and hybrid vehicles is given. It deals only with the near-term batteries, namely Pb/acid, Ni/Zn, and Ni/Fe, but the complete battery cycle is considered, i.e., mining and milling of raw materials, manufacture of the batteries, cases and covers; use of the batteries in electric vehicles, including the charge-discharge cycles; recycling of spent batteries; and disposal of nonrecyclable components. The gaseous, liquid, and solid emissions from various phases of the battery cycle are identified. The effluent dispersal in the environment is modeled and ecological effects are assessed in terms of biogeochemical cycles. The metabolic and toxic responses by humans and laboratory animals to constituents of the effluents are discussed. Pertinent environmental and health regulations related to the battery industry are summarized and regulatory implications for large-scale storage battery commercialization are discussed. Each of the seven sections were abstracted and indexed individually for EDB/ERA. Additional information is presented in the seven appendixes entitled; growth rate scenario for lead/acid battery development; changes in battery composition during discharge; dispersion of stack and fugitive emissions from battery-related operations; methodology for estimating population exposure to total suspended particulates and SO/sub 2/ resulting from central power station emissions for the daily battery charging demand of 10,000 electric vehicles; determination of As air emissions from Zn smelting; health effects: research related to EV battery technologies. (JGB)

  6. Pharmacokinetics of enrofloxacin and ceftiofur in plasma, interstitial fluid, and gastrointestinal tract of calves after subcutaneous injection, and bactericidal impacts on representative enteric bacteria.

    Science.gov (United States)

    Foster, D M; Jacob, M E; Warren, C D; Papich, M G

    2016-02-01

    This study's objectives were to determine intestinal antimicrobial concentrations in calves administered enrofloxacin or ceftiofur sodium subcutaneously, and their impact on representative enteric bacteria. Ultrafiltration devices were implanted in the ileum and colon of 12 steers, which received either enrofloxacin or ceftiofur sodium. Samples were collected over 48 h after drug administration for pharmacokinetic/pharmacodynamic analysis. Enterococcus faecalis or Salmonella enterica (5 × 10(5) CFU/mL of each) were exposed in vitro to peak and tail (48 h postadministration) concentrations of both drugs at each location for 24 h to determine inhibition of growth and change in MIC. Enrofloxacin had tissue penetration factors of 1.6 and 2.5 in the ileum and colon, while ciprofloxacin, an active metabolite of enrofloxacin, was less able to cross into the intestine (tissue penetration factors of 0.7 and 1.7). Ceftiofur was rapidly eliminated leading to tissue penetration factors of 0.39 and 0.25. All concentrations of enrofloxacin were bactericidal for S. enterica and significantly reduced E. faecalis. Peak ceftiofur concentration was bactericidal for S. enterica, and tail concentrations significantly reduced growth. E. faecalis experienced growth at all ceftiofur concentrations. The MICs for both organisms exposed to peak and tail concentrations of antimicrobials were unchanged at the end of the study. Enrofloxacin and ceftiofur achieved intestinal concentrations capable of reducing intestinal bacteria, yet the short exposure of ceftiofur in the intestine may select for resistant organisms. © 2015 John Wiley & Sons Ltd.

  7. Ecological risks of biological control agents: impacts on IPM

    NARCIS (Netherlands)

    Hokkanen, H.M.T.; Lenteren, van J.C.; Menzler-Hokkanen, I.

    2007-01-01

    Since the early days of integrated pest management a sound ecological foundation has been considered essential for the development of effective systems. From time to time, there have been attempts to evaluate the ways in which ecological theory is exploited in pest control, and to review the lessons

  8. Community Ecology

    CERN Document Server

    1988-01-01

    This book presents the proceedings of a workshop on community ecology organized at Davis, in April, 1986, sponsored by the Sloan Foundation. There have been several recent symposia on community ecology (Strong et. al., 1984, Diamond and Case, 1987) which have covered a wide range of topics. The goal of the workshop at Davis was more narrow: to explore the role of scale in developing a theoretical approach to understanding communities. There are a number of aspects of scale that enter into attempts to understand ecological communities. One of the most basic is organizational scale. Should community ecology proceed by building up from population biology? This question and its ramifications are stressed throughout the book and explored in the first chapter by Simon Levin. Notions of scale have long been important in understanding physical systems. Thus, in understanding the interactions of organisms with their physical environment, questions of scale become paramount. These more physical questions illustrate the...

  9. The ecology of religious beliefs

    Science.gov (United States)

    Botero, Carlos A.; Gardner, Beth; Kirby, Kathryn R.; Bulbulia, Joseph; Gavin, Michael C.; Gray, Russell D.

    2014-01-01

    Although ecological forces are known to shape the expression of sociality across a broad range of biological taxa, their role in shaping human behavior is currently disputed. Both comparative and experimental evidence indicate that beliefs in moralizing high gods promote cooperation among humans, a behavioral attribute known to correlate with environmental harshness in nonhuman animals. Here we combine fine-grained bioclimatic data with the latest statistical tools from ecology and the social sciences to evaluate the potential effects of environmental forces, language history, and culture on the global distribution of belief in moralizing high gods (n = 583 societies). After simultaneously accounting for potential nonindependence among societies because of shared ancestry and cultural diffusion, we find that these beliefs are more prevalent among societies that inhabit poorer environments and are more prone to ecological duress. In addition, we find that these beliefs are more likely in politically complex societies that recognize rights to movable property. Overall, our multimodel inference approach predicts the global distribution of beliefs in moralizing high gods with an accuracy of 91%, and estimates the relative importance of different potential mechanisms by which this spatial pattern may have arisen. The emerging picture is neither one of pure cultural transmission nor of simple ecological determinism, but rather a complex mixture of social, cultural, and environmental influences. Our methods and findings provide a blueprint for how the increasing wealth of ecological, linguistic, and historical data can be leveraged to understand the forces that have shaped the behavior of our own species. PMID:25385605

  10. What is dental ecology?

    Science.gov (United States)

    Cuozzo, Frank P; Sauther, Michelle L

    2012-06-01

    Teeth have long been used as indicators of primate ecology. Early work focused on the links between dental morphology, diet, and behavior, with more recent years emphasizing dental wear, microstructure, development, and biogeochemistry, to understand primate ecology. Our study of Lemur catta at the Beza Mahafaly Special Reserve, Madagascar, has revealed an unusual pattern of severe tooth wear and frequent tooth loss, primarily the result of consuming a fallback food for which these primates are not dentally adapted. Interpreting these data was only possible by combining our areas of expertise (dental anatomy [FC] and primate ecology [MS]). By integrating theoretical, methodological, and applied aspects of both areas of research, we adopted the term "dental ecology"-defined as the broad study of how teeth respond to the environment. Specifically, we view dental ecology as an interpretive framework using teeth as a vehicle for understanding an organism's ecology, which builds upon earlier work, but creates a new synthesis of anatomy and ecology that is only possible with detailed knowledge of living primates. This framework includes (1) identifying patterns of dental pathology and tooth use-wear, within the context of feeding ecology, behavior, habitat variation, and anthropogenic change, (2) assessing ways in which dental development and biogeochemical signals can reflect habitat, environmental change and/or stress, and (3) how dental microstructure and macro-morphology are adapted to, and reflect feeding ecology. Here we define dental ecology, provide a short summary of the development of this perspective, and place our new work into this context. Copyright © 2012 Wiley Periodicals, Inc.

  11. Delimiting the Boundary of Delhi for Effective Urban Political Ecology Investigations

    Directory of Open Access Journals (Sweden)

    Govind Singh

    2018-02-01

    Full Text Available Delhi, capital of the world’s largest democracy, is witnessing large-scale increase in population since the beginning of the twentieth century. Two prominent factors that have contributed to this include the shifting of capital of the British Raj from Calcutta (now Kolkata to Delhi in 1911 and the partition of India that accompanied its independence in 1947. Delhi continued to witness high rate of migration in post-independent India due to uneven implementation of development policies. Rising population led to spatial expansion and the largest connotation of Delhi today (National Capital Region is an area 36 times its size in 1947. Rising population has also had an adverse impact on Delhi’s natural resources. Consequently, clean air, water and land availability have become limited and Delhi today is undergoing a severe sustainability crisis. The latter requires urgent intervention for restoring Delhi’s urban ecosystem. Since urban areas are highly contested ecological spaces, urban ecological interventions are incomplete without political overtones. Thus, the success of urban ecological interventions lies in identifying politically correct boundaries which encompasses true ‘urban Delhi’ despite the political boundaries. This research contribution attempts to identify the geographical expanse of ‘urban Delhi’ amidst the various political terminologies that define Delhi. An understanding of various divisions and definitions of Delhi is also presented from the perspective of appreciating the challenges in urban planning. We conclude that urban ecology investigations in Delhi should be embedded within the ‘Delhi conurbation’, which represents a geographical area greater than the Delhi city-state but much smaller than Delhi NCR.

  12. Mapping social-ecological vulnerability to inform local decision making.

    Science.gov (United States)

    Thiault, Lauric; Marshall, Paul; Gelcich, Stefan; Collin, Antoine; Chlous, Frédérique; Claudet, Joachim

    2018-04-01

    An overarching challenge of natural resource management and biodiversity conservation is that relationships between people and nature are difficult to integrate into tools that can effectively guide decision making. Social-ecological vulnerability offers a valuable framework for identifying and understanding important social-ecological linkages, and the implications of dependencies and other feedback loops in the system. Unfortunately, its implementation at local scales has hitherto been limited due at least in part to the lack of operational tools for spatial representation of social-ecological vulnerability. We developed a method to map social-ecological vulnerability based on information on human-nature dependencies and ecosystem services at local scales. We applied our method to the small-scale fishery of Moorea, French Polynesia, by combining spatially explicit indicators of exposure, sensitivity, and adaptive capacity of both the resource (i.e., vulnerability of reef fish assemblages to fishing) and resource users (i.e., vulnerability of fishing households to the loss of fishing opportunity). Our results revealed that both social and ecological vulnerabilities varied considerably through space and highlighted areas where sources of vulnerability were high for both social and ecological subsystems (i.e., social-ecological vulnerability hotspots) and thus of high priority for management intervention. Our approach can be used to inform decisions about where biodiversity conservation strategies are likely to be more effective and how social impacts from policy decisions can be minimized. It provides a new perspective on human-nature linkages that can help guide sustainability management at local scales; delivers insights distinct from those provided by emphasis on a single vulnerability component (e.g., exposure); and demonstrates the feasibility and value of operationalizing the social-ecological vulnerability framework for policy, planning, and participatory

  13. Socio/economic/ecological impacts of nuclear power plants

    International Nuclear Information System (INIS)

    Golden, J.; Watson, J.

    1975-01-01

    A nuclear facility has both radiological and non-radiological effects on the environment. To minimize radiological effects, limits are set on releases of radioactive materials that will cause either direct or indirect exposure (such as the food chain). Exposure pathways for man and other organisms are described with comparisons of typical calculated doses and design objective doses. Non-radiological impacts of nuclear plants are classified as ecological-physical and socio/economic considerations, which include eighteen areas affected during each phase of the nuclear facility cycle. The ecological-physical environment is impacted in the areas of hydrology, terrestrial and aquatic ecology, and air and water quality. The socio-economic environment is impacted in areas of land use, tax base, employment, economic stimulus, relocation, lifestyle, demand for service, aesthetics, and power needs. Case studies of large construction projects are described in the appendix

  14. Ecological Risk Assessment of Jarosite Waste Disposal

    Directory of Open Access Journals (Sweden)

    Mihone Kerolli-Mustafa

    2015-07-01

    Full Text Available Jarosite waste, originating from zinc extraction industry, is considered hazardous due to the presence and the mobility of toxic metals that it contains. Its worldwide disposal in many tailing damps has become a major ecological concern. Three different methods, namely modified Synthetic Precipitation Leaching Procedure (SPLP, three-stage BCR sequential extraction procedure and Potential Ecological Risk Index (PERI Method were used to access the ecological risk of jarosite waste disposal in Mitrovica Industrial Park, Kosovo. The combination of these methods can effectively identify the comprehensive and single pollution levels of heavy metals such as Zn, Pb, Cd, Cu, Ni and As present in jarosite waste. Moreover, the great positive relevance between leaching behavior of heavy metals and F1 fraction was supported by principal component analysis (PCA. PERI results indicate that Cd showed a very high risk class to the environment. The ecological risk of heavy metals declines in the following order: Cd>Zn>Cu>Pb>Ni>As.

  15. Ecological Research Division, Marine Research Program

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    This report presents program summaries of the various projects sponsored during 1979 by the Marine Research Program of the Ecological Research Division. Program areas include the effects of petroleum hydrocarbons on the marine environment; a study of the baseline ecology of a proposed OTEC site near Puerto Rico; the environmental impact of offshore geothermal energy development; the movement of radionuclides through the marine environment; the environmental aspects of power plant cooling systems; and studies of the physical and biological oceangraphy of the continental shelves bordering the United States.

  16. Ecological Research Division, Marine Research Program

    International Nuclear Information System (INIS)

    1980-05-01

    This report presents program summaries of the various projects sponsored during 1979 by the Marine Research Program of the Ecological Research Division. Program areas include the effects of petroleum hydrocarbons on the marine environment; a study of the baseline ecology of a proposed OTEC site near Puerto Rico; the environmental impact of offshore geothermal energy development; the movement of radionuclides through the marine environment; the environmental aspects of power plant cooling systems; and studies of the physical and biological oceangraphy of the continental shelves bordering the United States

  17. The ecological research needs of business.

    Science.gov (United States)

    Armsworth, Paul R; Armsworth, Anastasia N; Compton, Natalie; Cottle, Phil; Davies, Ian; Emmett, Bridget A; Fandrich, Vanessa; Foote, Matthew; Gaston, Kevin J; Gardiner, Phil; Hess, Tim; Hopkins, John; Horsley, Nick; Leaver, Natasha; Maynard, Trevor; Shannon, Delia

    2010-04-01

    Businesses have an unrivalled ability to mobilize human, physical and financial capital, often manage large land holdings, and draw on resources and supply products that impact a wide array of ecosystems. Businesses therefore have the potential to make a substantial contribution to arresting declines in biodiversity and ecosystem services. To realize this potential, businesses require support from researchers in applied ecology to inform how they measure and manage their impacts on, and opportunities presented to them by, biodiversity and ecosystem services.We reviewed papers in leading applied ecology journals to assess the research contribution from existing collaborations involving businesses. We reviewed applications to, and grants funded by, the UK's Natural Environment Research Council for evidence of public investment in such collaborations. To scope opportunities for expanding collaborations with businesses, we conducted workshops with three sectors (mining and quarrying, insurance and manufacturing) in which participants identified exemplar ecological research questions of interest to their sector.Ten to fifteen per cent of primary research papers in Journal of Applied Ecology and Ecological Applications evidenced business involvement, mostly focusing on traditional rural industries (farming, fisheries and forestry). The review of UK research council funding found that 35% of applications mentioned business engagement, while only 1% of awarded grants met stricter criteria of direct business involvement.Some questions identified in the workshops aim to reduce costs from businesses' impacts on the environment and others to allow businesses to exploit new opportunities. Some questions are designed to inform long-term planning undertaken by businesses, but others would have more immediate commercial applications. Finally, some research questions are designed to streamline and make more effective those environmental policies that affect businesses

  18. The effects of hydroelectric gates on rivers, hydro-ecological diagnostic and management aid. The Fontauliere example (Ardeche)

    International Nuclear Information System (INIS)

    Valentin, S.

    1996-01-01

    Hydropower generation induces artificial fluctuations of flow and thus of hydrodynamic parameters in rivers, downstream of hydroelectric impoundments. On the Fontauliere river (Ardeche basin, France), the ecological effects of two different hydro-peaking regimes were tested and compared to a reference upstream reach. Fish, invertebrate and epilithic communities were surveyed in these reaches. The results enables to classify the factors responsible for the observed effects. The base flow between peaks was the most important for the studied site. When it was too low, aquatic communities were de-structured in comparison with the natural reach. These results enabled to suggest a current velocity threshold to respect in order to determine acceptable base flow for this type of stream. They also enabled to guide for the impact evaluation of hydro-peaking sites. An ecological diagnosis should include the study of the structure and composition of the communities. (author). 22 refs., 2 figs., 4 tabs

  19. Ecological communities with Lotka-Volterra dynamics

    Science.gov (United States)

    Bunin, Guy

    2017-04-01

    Ecological communities in heterogeneous environments assemble through the combined effect of species interaction and migration. Understanding the effect of these processes on the community properties is central to ecology. Here we study these processes for a single community subject to migration from a pool of species, with population dynamics described by the generalized Lotka-Volterra equations. We derive exact results for the phase diagram describing the dynamical behaviors, and for the diversity and species abundance distributions. A phase transition is found from a phase where a unique globally attractive fixed point exists to a phase where multiple dynamical attractors exist, leading to history-dependent community properties. The model is shown to possess a symmetry that also establishes a connection with other well-known models.

  20. Ecological aspects of nuclear power plants in coastal environment

    International Nuclear Information System (INIS)

    Lebreton, P.

    1976-01-01

    A review is presented about ecological effects of giant nuclear Power Plants (ca. 5,000 MWe) on coastal environment. From short to long time, the problems concern the following points of view: - physical: (sitology; necessity of ecological mapping); - mechanical: (the cooling systems. 'Courantology'. Disturbance of marine micro- and macro-organisms); - thermal: (the heated discharges; thermal pollution. Effects on dissolved chemicals and marine organisms. Acquaculture and its limits); - chemical and radiochemical: (synergistic pollutions. Chlorine vs. fouling. Acute or chronic radioactive effluents; concentration by food chains). The conclusions emphasize the necessity of 'pluridisciplinarity' and 'zero-point' definition. Three ecological categories can be distinguished on the basis of water physical turn-over; to this categories correspond various standards and recommandations for management of nuclear Power Plants in coastal zones [fr

  1. The community ecology of pathogens: coinfection, coexistence and community composition.

    Science.gov (United States)

    Seabloom, Eric W; Borer, Elizabeth T; Gross, Kevin; Kendig, Amy E; Lacroix, Christelle; Mitchell, Charles E; Mordecai, Erin A; Power, Alison G

    2015-04-01

    Disease and community ecology share conceptual and theoretical lineages, and there has been a resurgence of interest in strengthening links between these fields. Building on recent syntheses focused on the effects of host community composition on single pathogen systems, we examine pathogen (microparasite) communities using a stochastic metacommunity model as a starting point to bridge community and disease ecology perspectives. Such models incorporate the effects of core community processes, such as ecological drift, selection and dispersal, but have not been extended to incorporate host-pathogen interactions, such as immunosuppression or synergistic mortality, that are central to disease ecology. We use a two-pathogen susceptible-infected (SI) model to fill these gaps in the metacommunity approach; however, SI models can be intractable for examining species-diverse, spatially structured systems. By placing disease into a framework developed for community ecology, our synthesis highlights areas ripe for progress, including a theoretical framework that incorporates host dynamics, spatial structuring and evolutionary processes, as well as the data needed to test the predictions of such a model. Our synthesis points the way for this framework and demonstrates that a deeper understanding of pathogen community dynamics will emerge from approaches working at the interface of disease and community ecology. © 2015 John Wiley & Sons Ltd/CNRS.

  2. Research on the Mechanism of Cross Regional Grassland Ecological Compensation

    Science.gov (United States)

    Yang, Ran; Ma, Jun

    2018-01-01

    In recent years, grassland environmental damage has become serious, and grassland resources protection task has become heavy, grassland ecological compensation has become an effective way to solve this problem; but the current grassland ecological compensation standards were low, the effect is poor. The fundamental reason is the model of administrative division destroys the integrity of grassland. Based on the analysis of the status quo of grassland compensation, this paper tries to protect the grassland integrity, breaks the administrative division restriction, implements the space regulation, constructs the framework of cross-regional grassland ecological compensation mechanism, describes its operation process. It provides new way to realize the sustainable development of the grassland environment.

  3. Pathways from marine protected area design and management to ecological success

    Directory of Open Access Journals (Sweden)

    Murray A. Rudd

    2015-11-01

    Full Text Available Using an international dataset compiled from 121 sites in 87 marine protected areas (MPAs globally (Edgar et al., 2014, I assessed how various configurations of design and management conditions affected MPA ecological performance, measured in terms of fish species richness and biomass. The set-theoretic approach used Boolean algebra to identify pathways that combined up to five ‘NEOLI’ (No-take, Enforced, Old, Large, Isolated conditions and that were sufficient for achieving positive, and negative, ecological outcomes. Ecological isolation was overwhelming the most important condition affecting ecological outcomes but Old and Large were also conditions important for achieving high levels of biomass among large fishes (jacks, groupers, sharks. Solution coverage was uniformly low (0.50 for negative results (i.e., the absence of high biomass among the large commercially-exploited fishes, implying asymmetries in how MPAs may rebuild populations on the one hand and, on the other, protect against further decline. The results revealed complex interactions involving MPA design, implementation, and management conditions that affect MPA ecological performance. In general terms, the presence of no-take regulations and effective enforcement were insufficient to ensure MPA effectiveness on their own. Given the central role of ecological isolation in securing ecological benefits from MPAs, site selection in the design phase appears critical for success.

  4. Civic Ecology: Linking Social and Ecological Approaches in Extension

    Science.gov (United States)

    Krasny, Marianne E.; Tidball, Keith G.

    2010-01-01

    Civic ecology refers to the philosophy and science of community forestry, community gardening, watershed enhancement, and other volunteer-driven restoration practices in cities and elsewhere. Such practices, although often viewed as initiatives to improve a degraded environment, also foster social attributes of resilient social-ecological systems,…

  5. Commoditizing Nonhuman Animals and Their Consumers: Industrial Livestock Production, Animal Welfare, and Ecological Justice

    Science.gov (United States)

    McLeod-Kilmurray, Heather

    2012-01-01

    There is increasing research on the effects of industrial livestock production on the environment and human health, but less on the effects this has on animal welfare and ecological justice. The concept of ecological justice as a tool for achieving sustainability is gaining traction in the legal world. Klaus Bosselman defines ecological justice as…

  6. Non-linear effects of drought under shade: reconciling physiological and ecological models in plant communities.

    Science.gov (United States)

    Holmgren, Milena; Gómez-Aparicio, Lorena; Quero, José Luis; Valladares, Fernando

    2012-06-01

    The combined effects of shade and drought on plant performance and the implications for species interactions are highly debated in plant ecology. Empirical evidence for positive and negative effects of shade on the performance of plants under dry conditions supports two contrasting theoretical models about the role of shade under dry conditions: the trade-off and the facilitation hypotheses. We performed a meta-analysis of field and greenhouse studies evaluating the effects of drought at two or more irradiance levels on nine response variables describing plant physiological condition, growth, and survival. We explored differences in plant response across plant functional types, ecosystem types and methodological approaches. The data were best fit using quadratic models indicating a humped-back shape response to drought along an irradiance gradient for survival, whole plant biomass, maximum photosynthetic capacity, stomatal conductance and maximal photochemical efficiency. Drought effects were ameliorated at intermediate irradiance, becoming more severe at higher or lower light levels. This general pattern was maintained when controlling for potential variations in the strength of the drought treatment among light levels. Our quantitative meta-analysis indicates that dense shade ameliorates drought especially among drought-intolerant and shade-tolerant species. Wet tropical species showed larger negative effects of drought with increasing irradiance than semiarid and cold temperate species. Non-linear responses to irradiance were stronger under field conditions than under controlled greenhouse conditions. Non-linear responses to drought along the irradiance gradient reconciliate opposing views in plant ecology, indicating that facilitation is more likely within certain range of environmental conditions, fading under deep shade, especially for drought-tolerant species.

  7. PROMOTION OF ECOLOGIC PRODUCT CERTIFICATION AS INSTRUMENT TO SPEED UP THE ECOLOGIC AGRICULTURE

    Directory of Open Access Journals (Sweden)

    George MOISE

    2014-04-01

    Full Text Available This paper present a vision about the possibility to speed up the conversion process to an ecological agriculture in Romania. The link from ecological products consumer and ecologic agricultural producer is also explained from point of view of certification process. Presenting the consumer mentality and principles and rules of organic farming and certification can open the way to a sustainable and ecological agriculture.

  8. Effectiveness of aqueous and hydroalcoholic extracts of Acanthospermum australe (Loefl. Kuntze against diarrhea-inducing bacteria

    Directory of Open Access Journals (Sweden)

    R. Mallmann

    2018-01-01

    Full Text Available Abstract Leaves and roots of Acanthospermum australe (Asteraceae have been used in Brazilian folk medicine for the treatment of various ailments including diarrhea, skin diseases, blennorrhagia, dyspepsia, parasitic worms and malaria. The aim of study was to characterize the chemical profiles of the aqueous and hydroalcoholic extracts of leaves and roots of A. australe, and to evaluate their antimicrobial activities against diarrhea-inducing bacteria (Enterococcus faecalis, Shigella dysenteriae and Yersinia enterocolitica, as well as their cytotoxic properties. Aqueous leaf extracts were obtained by infusion, while aqueous root extracts were obtained by decoction. The hydroalcoholic leaf and root extracts were prepared by maceration in 90% ethanol for 3 days. Antimicrobial activity was assessed using standard techniques and cytotoxicity was evaluated using Chinese hamster ovary cells CHO-K1. Chemical analysis revealed the presence of tannins, flavonoids, saponins and phenolic compounds in the extracts. Although root extracts were not effective against E. faecalis, leaf extracts at concentrations of 20 mg/mL exhibited bactericidal activities against this microorganism. The hydroalcoholic root extract was unique in presenting a bactericidal effect against S. dysenteriae. None of the extracts showed bacteriostatic or bactericidal activities against Y. enterocolitica. The results presented herein demonstrate that the Gram-positive E. faecalis and the Gram-negative S. dysenteriae were susceptible to A. australe extracts, although bacteriostatic/bactericidal activities were only observed at concentrations considered too high for clinical application. Our results support the ethnopharmacological use of A. australe in the treatment of gastrointestinal disorders, particularly diarrhea caused by infectious bacteria, although further studies are required to determine the anti-diarrhea effects and the toxicities of the extracts in vivo.

  9. How do land-based salmonid farms affect stream ecology?

    International Nuclear Information System (INIS)

    Tello, A.; Corner, R.A.; Telfer, T.C.

    2010-01-01

    Increasing research is highlighting the fact that streams provide crucial ecosystem services through the biogeochemical and ecological processes they sustain. Freshwater land-based salmonid farms commonly discharge their effluents into low order, headwater streams, partly due to the fact that adequate freshwater resources for production are commonly found in undisturbed areas. We review the effects of salmonid farm effluents on different biological components of stream ecosystems. Relevant considerations related to the temporal and spatial scales of effluent discharge and ecological effects are discussed. These highlight the need to characterize the patterns of stressor discharge when assessing environmental impacts and designing ecological effects studies. The potential role of multiple stressors in disrupting ecosystem structure and function is discussed with an emphasis on aquaculture veterinary medicines. Further research on the effects of veterinary medicines using relevant exposure scenarios would significantly contribute to our understanding of their impact in relation to other effluent stressors. - This article reviews the effects of aquaculture effluents on stream ecosystems with an emphasis on veterinary medicines and the temporal patterns of effluent discharge.

  10. Interim balance: Ecology

    International Nuclear Information System (INIS)

    Kogon, E.; Jungk, R.

    1981-01-01

    Subjects: The ecology problem - world wide. Sectoral balances: The examples of energy, transportation, chemistry, agriculture and food industry, water supply. Destruction of nature and human discord. Conservatives in our political parties and their views on environmental protection. Alliance between reds and 'greens', integration between reds and greens. The Rhine initiative. Lead respects no borders, experiences of citizens' action groups in Lothringia and the Saar district. International airport Munich-II/comments by a protestant. 'Give priority to life'/A hearing on environmental protection. 4:96 - 'greens' in the Bremen Senate. Policy in a hard-hearing world/psychology of citizens' action groups. Critical ecological research and scientific establishment. Full productivity and ecology. The deluge to follow/Hints on how to build an ark. Symbiosis is more than coexistence/Ecologists' social theory. Throwing in two hundred elementary particles/on the way to an ecological concept of science. Scientific journals. Alternative literature. Teaching model for a teaching subject 'ecology'. (orig.) [de

  11. Predictive systems ecology.

    Science.gov (United States)

    Evans, Matthew R; Bithell, Mike; Cornell, Stephen J; Dall, Sasha R X; Díaz, Sandra; Emmott, Stephen; Ernande, Bruno; Grimm, Volker; Hodgson, David J; Lewis, Simon L; Mace, Georgina M; Morecroft, Michael; Moustakas, Aristides; Murphy, Eugene; Newbold, Tim; Norris, K J; Petchey, Owen; Smith, Matthew; Travis, Justin M J; Benton, Tim G

    2013-11-22

    Human societies, and their well-being, depend to a significant extent on the state of the ecosystems that surround them. These ecosystems are changing rapidly usually in response to anthropogenic changes in the environment. To determine the likely impact of environmental change on ecosystems and the best ways to manage them, it would be desirable to be able to predict their future states. We present a proposal to develop the paradigm of predictive systems ecology, explicitly to understand and predict the properties and behaviour of ecological systems. We discuss the necessary and desirable features of predictive systems ecology models. There are places where predictive systems ecology is already being practised and we summarize a range of terrestrial and marine examples. Significant challenges remain but we suggest that ecology would benefit both as a scientific discipline and increase its impact in society if it were to embrace the need to become more predictive.

  12. An ecosystem services approach to the ecological effects of salvage logging: valuation of seed dispersal.

    Science.gov (United States)

    Leverkus, Alexandro B; Castro, Jorge

    2017-06-01

    Forest disturbances diminish ecosystem services and boost disservices. Because post-disturbance management intends to recover the greatest possible value, selling timber often prevails over other considerations. Ecological research has shown diverse effects of salvage logging, yet such research has focused on the biophysical component of post-disturbance ecosystems and lacks the link with human well-being. Here we bridge that gap under the ecosystem services framework by assessing the impact of post-fire management on a non-timber value. By employing the replacement cost method, we calculated the value of the post-fire natural regeneration of Holm oaks in southern Spain under three post-fire management options by considering the cost of planting instead. The value of this ecosystem service in non-intervention areas doubled that of salvage-logged stands due to the preference for standing dead trees by the main seed disperser. Still, most of the value resulted from the resprouting capacity of oaks. The value of this and other ecosystem services should be added to traditional cost/benefit analyses of post-disturbance management. We thus call for a more holistic approach to salvage logging research, one that explicitly links ecological processes with human well-being through ecosystem services, to better inform decision-makers on the outcomes of post-disturbance management. © 2017 by the Ecological Society of America.

  13. Towards More Effective Water Quality Governance : A Review of Social-Economic, Legal and Ecological Perspectives and Their Interactions

    NARCIS (Netherlands)

    van Rijswick, H.F.M.W.|info:eu-repo/dai/nl/099909189; Wuijts, S.; Driessen, P.P.J.|info:eu-repo/dai/nl/069081417

    2018-01-01

    In this article, social-economic, legal and ecological perspectives on effectiveness of water quality governance and their interactions have been studied. Worldwide, authorities are facing the challenge of restoring and preserving aquatic ecosystems in accordance with the United Nations Sustainable

  14. The role of ecological models in linking ecological risk assessment to ecosystem services in agroecosystems

    NARCIS (Netherlands)

    Galic, N.G.; Schmolke, A.; Forbes, V.; Baveco, J.M.; Brink, van den P.J.

    2012-01-01

    Agricultural practices are essential for sustaining the human population, but at the same time they can directly disrupt ecosystem functioning. Ecological risk assessment (ERA) aims to estimate possible adverse effects of human activities on ecosystems and their parts. Current ERA practices,

  15. [Heavy metal pollution ecology of macro-fungi: research advances and expectation].

    Science.gov (United States)

    Zhou, Qi-xing; An, Xin-long; Wei, Shu-he

    2008-08-01

    Macro-fungi are the main component of biosphere and one of the ecological resources, and play very important roles in matter cycling and in maintaining ecological balances. This paper summarized and reviewed the research advances in the eco-toxicological effects of heavy metals on macro-fungi, the bioaccumulation function of macro-fungi on heavy metals, the ecological adaptation mechanisms of macro-fungi to heavy metal pollution, the role of macro-fungi as a bio-indicator of heavy metal pollution, and the potential of macro-fungi in the ecological remediation of contaminated environment. To strengthen the researches on the heavy metal pollution ecology of macro-fungi would be of practical significance in the reasonable utilization of macro-fungi resources and in the ecological remediation of contaminated environment.

  16. Models for optimum thermo-ecological criteria of actual thermal cycles

    Directory of Open Access Journals (Sweden)

    Açikkalp Emin

    2013-01-01

    Full Text Available In this study, the ecological optimization point of irreversible thermal cycles (refrigerator, heat pump and power cycles was investigated. The importance of ecological optimization is to propose a way to use fuels and energy source more efficiently because of an increasing energy need and environmental pollution. It provides this by maximizing obtained (or minimizing supplied work and minimizing entropy generation for irreversible (actual thermal cycles. In this research, ecological optimization was defined for all basic irreversible thermal cycles, by using the first and second laws of thermodynamics. Finally, the ecological optimization was defined in thermodynamic cycles and results were given to show the effects of the cycles’ ecological optimization point, efficiency, COP and power output (or input, and exergy destruction.

  17. Recombinant Protein Truncation Strategy for Inducing Bactericidal Antibodies to the Macrophage Infectivity Potentiator Protein of Neisseria meningitidis and Circumventing Potential Cross-Reactivity with Human FK506-Binding Proteins

    OpenAIRE

    Bielecka, Magdalena K.; Devos, Nathalie; Gilbert, Mélanie; Hung, Miao-Chiu; Weynants, Vincent; Heckels, John E.; Christodoulides, Myron

    2014-01-01

    A recombinant macrophage infectivity potentiator (rMIP) protein of Neisseria meningitidis induces significant serum bactericidal antibody production in mice and is a candidate meningococcal vaccine antigen. However, bioinformatics analysis of MIP showed some amino acid sequence similarity to human FK506-binding proteins (FKBPs) in residues 166 to 252 located in the globular domain of the protein. To circumvent the potential concern over generating antibodies that could recognize human protein...

  18. Effects of ecological flooding on the temporal and spatial dynamics of carabid beetles (Coleoptera, Carabidae and springtails (Collembola in a polder habitat

    Directory of Open Access Journals (Sweden)

    Tanja Lessel

    2011-05-01

    Full Text Available Within the scope of the Integrated Rhine Program an ecological flood gate and channel was inserted into the polder “Ingelheim” to enhance animal and plant diversity. In 2008, carabid beetles and springtails were collected, using pitfall traps, to measure the effects of ecological flooding and a strong precipitation event at a flood-disturbed and a dry location in this area. At both localities, xerophilic and mesophilic carabid beetle species were dominant throughout the study period. The total number of individuals of hygrophilic species was comparatively constant, while species number increased, partly due to the changed moisture conditions caused by ecological flooding and strong precipitation. Carabid beetle diversity and evenness decreased marginally when ecological flooding was absent. Springtails represent a less mobile arthropod order, and as such the impact of ecological flooding was stronger. An increase in both numbers of species and individuals of hygrophilic and hygrotolerant species occurred in the flood-disturbed location after ecological flooding. After the sites at both locations had dried, the number of individuals belonging to these species declined rapidly. In contrast to carabid species, the strong precipitation event showed no influence on hygrophilic springtail species. Thus, collembolan diversity and evenness decreased markedly in the absence of flooding. We showed that ecological flooding has an influence on the spatial and temporal dynamics of different arthropod groups that inhabit the polder “Ingelheim”. These findings demonstrate the importance of using different arthropod groups as bioindicators in determining the ecological value of a particular polder design.

  19. Ecological Understanding 2: Transformation--A Key to Ecological Understanding.

    Science.gov (United States)

    Carlsson, Britta

    2002-01-01

    Describes the structure and general features of the phenomenon of ecological understanding. Presents qualitatively different ways of experiencing cycling of matter and the flow of energy in the context of ecosystems. The idea of transformation is key to the development of ecological understanding. (Contains 17 references.) (Author/YDS)

  20. Ecological connectivity networks in rapidly expanding cities

    Directory of Open Access Journals (Sweden)

    Amal Najihah M. Nor

    2017-06-01

    Full Text Available Urban expansion increases fragmentation of the landscape. In effect, fragmentation decreases connectivity, causes green space loss and impacts upon the ecology and function of green space. Restoration of the functionality of green space often requires restoring the ecological connectivity of this green space within the city matrix. However, identifying ecological corridors that integrate different structural and functional connectivity of green space remains vague. Assessing connectivity for developing an ecological network by using efficient models is essential to improve these networks under rapid urban expansion. This paper presents a novel methodological approach to assess and model connectivity for the Eurasian tree sparrow (Passer montanus and Yellow-vented bulbul (Pycnonotus goiavier in three cities (Kuala Lumpur, Malaysia; Jakarta, Indonesia and Metro Manila, Philippines. The approach identifies potential priority corridors for ecological connectivity networks. The study combined circuit models, connectivity analysis and least-cost models to identify potential corridors by integrating structure and function of green space patches to provide reliable ecological connectivity network models in the cities. Relevant parameters such as landscape resistance and green space structure (vegetation density, patch size and patch distance were derived from an expert and literature-based approach based on the preference of bird behaviour. The integrated models allowed the assessment of connectivity for both species using different measures of green space structure revealing the potential corridors and least-cost pathways for both bird species at the patch sites. The implementation of improvements to the identified corridors could increase the connectivity of green space. This study provides examples of how combining models can contribute to the improvement of ecological networks in rapidly expanding cities and demonstrates the usefulness of such